OpenCloudOS-Kernel/drivers/scsi/NCR5380.c

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License cleanup: add SPDX GPL-2.0 license identifier to files with no license Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-01 22:07:57 +08:00
// SPDX-License-Identifier: GPL-2.0
/*
* NCR 5380 generic driver routines. These should make it *trivial*
* to implement 5380 SCSI drivers under Linux with a non-trantor
* architecture.
*
* Note that these routines also work with NR53c400 family chips.
*
* Copyright 1993, Drew Eckhardt
* Visionary Computing
* (Unix and Linux consulting and custom programming)
* drew@colorado.edu
* +1 (303) 666-5836
*
* For more information, please consult
*
* NCR 5380 Family
* SCSI Protocol Controller
* Databook
*
* NCR Microelectronics
* 1635 Aeroplaza Drive
* Colorado Springs, CO 80916
* 1+ (719) 578-3400
* 1+ (800) 334-5454
*/
/*
* With contributions from Ray Van Tassle, Ingmar Baumgart,
* Ronald van Cuijlenborg, Alan Cox and others.
*/
/* Ported to Atari by Roman Hodek and others. */
/* Adapted for the Sun 3 by Sam Creasey. */
/*
* Design
*
* This is a generic 5380 driver. To use it on a different platform,
* one simply writes appropriate system specific macros (ie, data
* transfer - some PC's will use the I/O bus, 68K's must use
* memory mapped) and drops this file in their 'C' wrapper.
*
* As far as command queueing, two queues are maintained for
* each 5380 in the system - commands that haven't been issued yet,
* and commands that are currently executing. This means that an
* unlimited number of commands may be queued, letting
* more commands propagate from the higher driver levels giving higher
* throughput. Note that both I_T_L and I_T_L_Q nexuses are supported,
* allowing multiple commands to propagate all the way to a SCSI-II device
* while a command is already executing.
*
*
* Issues specific to the NCR5380 :
*
* When used in a PIO or pseudo-dma mode, the NCR5380 is a braindead
* piece of hardware that requires you to sit in a loop polling for
* the REQ signal as long as you are connected. Some devices are
* brain dead (ie, many TEXEL CD ROM drives) and won't disconnect
ncr5380: Rework disconnect versus poll logic The atari_NCR5380.c and NCR5380.c core drivers differ in their handling of target disconnection. This is partly because atari_NCR5380.c had all of the polling and sleeping removed to become entirely interrupt-driven, and it is partly because of damage done to NCR5380.c after atari_NCR5380.c was forked. See commit 37cd23b44929 ("Linux 2.1.105") in history/history.git. The polling changes that were made in v2.1.105 are questionable at best: if REQ is not already asserted when NCR5380_transfer_pio() is invoked, and if the expected phase is DATA IN or DATA OUT, the function will schedule main() to execute after USLEEP_SLEEP jiffies and then return. The problems here are the expected REQ timing and the sleep interval*. Avoid this issue by using NCR5380_poll_politely() instead of scheduling main(). The atari_NCR5380.c core driver requires the use of the chip interrupt and always permits target disconnection. It sets the cmd->device->disconnect flag when a device disconnects, but never tests this flag. The NCR5380.c core driver permits disconnection only when instance->irq != NO_IRQ. It sets the cmd->device->disconnect flag when a device disconnects and it tests this flag in a couple of places: 1. During NCR5380_information_transfer(), following COMMAND OUT phase, if !cmd->device->disconnect, the initiator will take a guess as to whether or not the target will then choose to go to MESSAGE IN phase and disconnect. If the driver guesses "yes", it will schedule main() to execute after USLEEP_SLEEP jiffies and then return there. Unfortunately the driver may guess "yes" even after it has denied the target the disconnection privilege. When the target does not disconnect, the sleep can be beneficial, assuming the sleep interval is appropriate (mostly it is not*). And even if the driver guesses "yes" correctly, and the target would then disconnect, the driver still has to go through the MESSAGE IN phase in order to get to BUS FREE phase. The main loop can do nothing useful until BUS FREE, and sleeping just delays the phase transition. 2. If !cmd->device->disconnect and REQ is not already asserted when NCR5380_information_transfer() is invoked, the function polls for REQ for USLEEP_POLL jiffies. If REQ is not asserted, it then schedules main() to execute after USLEEP_SLEEP jiffies and returns. The idea is apparently to yeild the CPU while waiting for REQ. This is conditional upon !cmd->device->disconnect, but there seems to be no rhyme or reason for that. For example, the flag may be unset because disconnection privilege was denied because the driver has no IRQ. Or the flag may be unset because the device has never needed to disconnect before. Or if the flag is set, disconnection may have no relevance to the present bus phase. Another deficiency of the existing algorithm is as follows. When the driver has no IRQ, it prevents disconnection, and generally polls and sleeps more than it would normally. Now, if the driver is going to poll anyway, why not allow the target to disconnect? That way the driver can do something useful with the bus instead of polling unproductively! Avoid this pointless latency, complexity and guesswork by using NCR5380_poll_politely() instead of scheduling main(). * For g_NCR5380, the time intervals for USLEEP_SLEEP and USLEEP_POLL are 200 ms and 10 ms, respectively. They are 20 ms and 200 ms respectively for the other NCR5380 drivers. There doesn't seem to be any reason for this discrepancy. The timing seems to have no relation to the type of adapter. Bizarrely, the timing in g_NCR5380 seems to relate only to one particular type of target device. This patch attempts to solve the problem for all NCR5380 drivers and all target devices. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:26 +08:00
* while doing long seek operations. [...] These
* broken devices are the exception rather than the rule and I'd rather
* spend my time optimizing for the normal case.
*
* Architecture :
*
* At the heart of the design is a coroutine, NCR5380_main,
* which is started from a workqueue for each NCR5380 host in the
* system. It attempts to establish I_T_L or I_T_L_Q nexuses by
* removing the commands from the issue queue and calling
* NCR5380_select() if a nexus is not established.
*
* Once a nexus is established, the NCR5380_information_transfer()
* phase goes through the various phases as instructed by the target.
* if the target goes into MSG IN and sends a DISCONNECT message,
* the command structure is placed into the per instance disconnected
* queue, and NCR5380_main tries to find more work. If the target is
* idle for too long, the system will try to sleep.
*
* If a command has disconnected, eventually an interrupt will trigger,
* calling NCR5380_intr() which will in turn call NCR5380_reselect
* to reestablish a nexus. This will run main if necessary.
*
* On command termination, the done function will be called as
* appropriate.
*
* SCSI pointers are maintained in the SCp field of SCSI command
* structures, being initialized after the command is connected
* in NCR5380_select, and set as appropriate in NCR5380_information_transfer.
* Note that in violation of the standard, an implicit SAVE POINTERS operation
* is done, since some BROKEN disks fail to issue an explicit SAVE POINTERS.
*/
/*
* Using this file :
* This file a skeleton Linux SCSI driver for the NCR 5380 series
* of chips. To use it, you write an architecture specific functions
* and macros and include this file in your driver.
*
* These macros MUST be defined :
*
* NCR5380_read(register) - read from the specified register
*
* NCR5380_write(register, value) - write to the specific register
*
* NCR5380_implementation_fields - additional fields needed for this
* specific implementation of the NCR5380
*
* Either real DMA *or* pseudo DMA may be implemented
*
* NCR5380_dma_xfer_len - determine size of DMA/PDMA transfer
* NCR5380_dma_send_setup - execute DMA/PDMA from memory to 5380
* NCR5380_dma_recv_setup - execute DMA/PDMA from 5380 to memory
* NCR5380_dma_residual - residual byte count
*
* The generic driver is initialized by calling NCR5380_init(instance),
* after setting the appropriate host specific fields and ID.
*/
#ifndef NCR5380_io_delay
#define NCR5380_io_delay(x)
#endif
#ifndef NCR5380_acquire_dma_irq
#define NCR5380_acquire_dma_irq(x) (1)
#endif
#ifndef NCR5380_release_dma_irq
#define NCR5380_release_dma_irq(x)
#endif
static unsigned int disconnect_mask = ~0;
module_param(disconnect_mask, int, 0444);
static int do_abort(struct Scsi_Host *);
static void do_reset(struct Scsi_Host *);
static void bus_reset_cleanup(struct Scsi_Host *);
/**
* initialize_SCp - init the scsi pointer field
* @cmd: command block to set up
*
* Set up the internal fields in the SCSI command.
*/
static inline void initialize_SCp(struct scsi_cmnd *cmd)
{
/*
* Initialize the Scsi Pointer field so that all of the commands in the
* various queues are valid.
*/
if (scsi_bufflen(cmd)) {
cmd->SCp.buffer = scsi_sglist(cmd);
cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
cmd->SCp.this_residual = cmd->SCp.buffer->length;
} else {
cmd->SCp.buffer = NULL;
cmd->SCp.ptr = NULL;
cmd->SCp.this_residual = 0;
}
ncr5380: Fix autosense bugs NCR5380_information_transfer() may re-queue a command for autosense, after calling scsi_eh_prep_cmnd(). This creates several possibilities: 1. Reselection may intervene before the re-queued command gets processed. If the reconnected command then undergoes autosense, this causes the scsi_eh_save data from the previous command to be overwritten. 2. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(), a new REQUEST SENSE command may arrive. This would be queued ahead of any command already undergoing autosense, which means the scsi_eh_save data might be restored to the wrong command. 3. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(), eh_abort_handler() may abort the command. But the scsi_eh_save data is not discarded, which means the scsi_eh_save data might be incorrectly restored to the next REQUEST SENSE command issued. This patch adds a new autosense list so that commands that are re-queued because of a CHECK CONDITION result can be kept apart from the REQUEST SENSE commands that arrive via queuecommand. This patch also adds a function dedicated to dequeueing and preparing the next command for processing. By refactoring the main loop in this way, scsi_eh_save takes place when an autosense command is dequeued rather than when re-queued. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:06:00 +08:00
cmd->SCp.Status = 0;
cmd->SCp.Message = 0;
}
static inline void advance_sg_buffer(struct scsi_cmnd *cmd)
{
struct scatterlist *s = cmd->SCp.buffer;
if (!cmd->SCp.this_residual && s && !sg_is_last(s)) {
cmd->SCp.buffer = sg_next(s);
cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
cmd->SCp.this_residual = cmd->SCp.buffer->length;
}
}
static inline void set_resid_from_SCp(struct scsi_cmnd *cmd)
{
int resid = cmd->SCp.this_residual;
struct scatterlist *s = cmd->SCp.buffer;
if (s)
while (!sg_is_last(s)) {
s = sg_next(s);
resid += s->length;
}
scsi_set_resid(cmd, resid);
}
/**
* NCR5380_poll_politely2 - wait for two chip register values
* @hostdata: host private data
* @reg1: 5380 register to poll
* @bit1: Bitmask to check
* @val1: Expected value
* @reg2: Second 5380 register to poll
* @bit2: Second bitmask to check
* @val2: Second expected value
* @wait: Time-out in jiffies
*
* Polls the chip in a reasonably efficient manner waiting for an
* event to occur. After a short quick poll we begin to yield the CPU
* (if possible). In irq contexts the time-out is arbitrarily limited.
* Callers may hold locks as long as they are held in irq mode.
*
* Returns 0 if either or both event(s) occurred otherwise -ETIMEDOUT.
*/
static int NCR5380_poll_politely2(struct NCR5380_hostdata *hostdata,
unsigned int reg1, u8 bit1, u8 val1,
unsigned int reg2, u8 bit2, u8 val2,
unsigned long wait)
{
unsigned long n = hostdata->poll_loops;
unsigned long deadline = jiffies + wait;
do {
if ((NCR5380_read(reg1) & bit1) == val1)
return 0;
if ((NCR5380_read(reg2) & bit2) == val2)
return 0;
cpu_relax();
} while (n--);
if (irqs_disabled() || in_interrupt())
return -ETIMEDOUT;
/* Repeatedly sleep for 1 ms until deadline */
while (time_is_after_jiffies(deadline)) {
schedule_timeout_uninterruptible(1);
if ((NCR5380_read(reg1) & bit1) == val1)
return 0;
if ((NCR5380_read(reg2) & bit2) == val2)
return 0;
}
return -ETIMEDOUT;
}
#if NDEBUG
static struct {
unsigned char mask;
const char *name;
} signals[] = {
{SR_DBP, "PARITY"},
{SR_RST, "RST"},
{SR_BSY, "BSY"},
{SR_REQ, "REQ"},
{SR_MSG, "MSG"},
{SR_CD, "CD"},
{SR_IO, "IO"},
{SR_SEL, "SEL"},
{0, NULL}
},
basrs[] = {
{BASR_END_DMA_TRANSFER, "END OF DMA"},
{BASR_DRQ, "DRQ"},
{BASR_PARITY_ERROR, "PARITY ERROR"},
{BASR_IRQ, "IRQ"},
{BASR_PHASE_MATCH, "PHASE MATCH"},
{BASR_BUSY_ERROR, "BUSY ERROR"},
{BASR_ATN, "ATN"},
{BASR_ACK, "ACK"},
{0, NULL}
},
icrs[] = {
{ICR_ASSERT_RST, "ASSERT RST"},
{ICR_ARBITRATION_PROGRESS, "ARB. IN PROGRESS"},
{ICR_ARBITRATION_LOST, "LOST ARB."},
{ICR_ASSERT_ACK, "ASSERT ACK"},
{ICR_ASSERT_BSY, "ASSERT BSY"},
{ICR_ASSERT_SEL, "ASSERT SEL"},
{ICR_ASSERT_ATN, "ASSERT ATN"},
{ICR_ASSERT_DATA, "ASSERT DATA"},
{0, NULL}
},
mrs[] = {
{MR_BLOCK_DMA_MODE, "BLOCK DMA MODE"},
{MR_TARGET, "TARGET"},
{MR_ENABLE_PAR_CHECK, "PARITY CHECK"},
{MR_ENABLE_PAR_INTR, "PARITY INTR"},
{MR_ENABLE_EOP_INTR, "EOP INTR"},
{MR_MONITOR_BSY, "MONITOR BSY"},
{MR_DMA_MODE, "DMA MODE"},
{MR_ARBITRATE, "ARBITRATE"},
{0, NULL}
};
/**
* NCR5380_print - print scsi bus signals
* @instance: adapter state to dump
*
* Print the SCSI bus signals for debugging purposes
*/
static void NCR5380_print(struct Scsi_Host *instance)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
unsigned char status, basr, mr, icr, i;
status = NCR5380_read(STATUS_REG);
mr = NCR5380_read(MODE_REG);
icr = NCR5380_read(INITIATOR_COMMAND_REG);
basr = NCR5380_read(BUS_AND_STATUS_REG);
printk(KERN_DEBUG "SR = 0x%02x : ", status);
for (i = 0; signals[i].mask; ++i)
if (status & signals[i].mask)
printk(KERN_CONT "%s, ", signals[i].name);
printk(KERN_CONT "\nBASR = 0x%02x : ", basr);
for (i = 0; basrs[i].mask; ++i)
if (basr & basrs[i].mask)
printk(KERN_CONT "%s, ", basrs[i].name);
printk(KERN_CONT "\nICR = 0x%02x : ", icr);
for (i = 0; icrs[i].mask; ++i)
if (icr & icrs[i].mask)
printk(KERN_CONT "%s, ", icrs[i].name);
printk(KERN_CONT "\nMR = 0x%02x : ", mr);
for (i = 0; mrs[i].mask; ++i)
if (mr & mrs[i].mask)
printk(KERN_CONT "%s, ", mrs[i].name);
printk(KERN_CONT "\n");
}
static struct {
unsigned char value;
const char *name;
} phases[] = {
{PHASE_DATAOUT, "DATAOUT"},
{PHASE_DATAIN, "DATAIN"},
{PHASE_CMDOUT, "CMDOUT"},
{PHASE_STATIN, "STATIN"},
{PHASE_MSGOUT, "MSGOUT"},
{PHASE_MSGIN, "MSGIN"},
{PHASE_UNKNOWN, "UNKNOWN"}
};
/**
* NCR5380_print_phase - show SCSI phase
* @instance: adapter to dump
*
* Print the current SCSI phase for debugging purposes
*/
static void NCR5380_print_phase(struct Scsi_Host *instance)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
unsigned char status;
int i;
status = NCR5380_read(STATUS_REG);
if (!(status & SR_REQ))
shost_printk(KERN_DEBUG, instance, "REQ not asserted, phase unknown.\n");
else {
for (i = 0; (phases[i].value != PHASE_UNKNOWN) &&
(phases[i].value != (status & PHASE_MASK)); ++i)
;
shost_printk(KERN_DEBUG, instance, "phase %s\n", phases[i].name);
}
}
#endif
/**
* NCR5380_info - report driver and host information
* @instance: relevant scsi host instance
*
* For use as the host template info() handler.
*/
static const char *NCR5380_info(struct Scsi_Host *instance)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
return hostdata->info;
}
/**
* NCR5380_init - initialise an NCR5380
* @instance: adapter to configure
* @flags: control flags
*
* Initializes *instance and corresponding 5380 chip,
* with flags OR'd into the initial flags value.
*
* Notes : I assume that the host, hostno, and id bits have been
* set correctly. I don't care about the irq and other fields.
*
* Returns 0 for success
*/
static int NCR5380_init(struct Scsi_Host *instance, int flags)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
int i;
unsigned long deadline;
unsigned long accesses_per_ms;
instance->max_lun = 7;
hostdata->host = instance;
hostdata->id_mask = 1 << instance->this_id;
hostdata->id_higher_mask = 0;
for (i = hostdata->id_mask; i <= 0x80; i <<= 1)
if (i > hostdata->id_mask)
hostdata->id_higher_mask |= i;
for (i = 0; i < 8; ++i)
hostdata->busy[i] = 0;
hostdata->dma_len = 0;
ncr5380: Change instance->host_lock to hostdata->lock NCR5380.c presently uses the instance->host_lock spin lock. Convert this to a new spin lock that protects the NCR5380_hostdata struct. atari_NCR5380.c previously used local_irq_save/restore() rather than a spin lock. Convert this to hostdata->lock in irq mode. For SMP platforms, the interrupt handler now also acquires the spin lock. This brings all locking in the two core drivers into agreement. Adding this locking also means that a bunch of volatile qualifiers can be removed from the members of the NCR5380_hostdata struct. This is done in a subsequent patch. Proper locking will allow the abort handler to locate a command being aborted. This is presently impossible if the abort handler is invoked when the command has been moved from a queue to a pointer on the stack. (If eh_abort_handler can't determine whether a command has been completed or is still being processed then it can't decide whether to return success or failure.) The hostdata spin lock is now held when calling NCR5380_select() and NCR5380_information_transfer(). Where possible, the lock is dropped for polling and PIO transfers. Clean up the now-redundant SELECT_ENABLE_REG writes, that used to provide limited mutual exclusion between information_transfer() and reselect(). Accessing hostdata->connected without data races means taking the lock; cleanup these accesses. The new spin lock falls away for m68k and other UP builds, so this should have little impact there. In the SMP case the new lock should be uncontested even when the SCSI bus is contested. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:51 +08:00
spin_lock_init(&hostdata->lock);
hostdata->connected = NULL;
ncr5380: Fix autosense bugs NCR5380_information_transfer() may re-queue a command for autosense, after calling scsi_eh_prep_cmnd(). This creates several possibilities: 1. Reselection may intervene before the re-queued command gets processed. If the reconnected command then undergoes autosense, this causes the scsi_eh_save data from the previous command to be overwritten. 2. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(), a new REQUEST SENSE command may arrive. This would be queued ahead of any command already undergoing autosense, which means the scsi_eh_save data might be restored to the wrong command. 3. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(), eh_abort_handler() may abort the command. But the scsi_eh_save data is not discarded, which means the scsi_eh_save data might be incorrectly restored to the next REQUEST SENSE command issued. This patch adds a new autosense list so that commands that are re-queued because of a CHECK CONDITION result can be kept apart from the REQUEST SENSE commands that arrive via queuecommand. This patch also adds a function dedicated to dequeueing and preparing the next command for processing. By refactoring the main loop in this way, scsi_eh_save takes place when an autosense command is dequeued rather than when re-queued. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:06:00 +08:00
hostdata->sensing = NULL;
INIT_LIST_HEAD(&hostdata->autosense);
INIT_LIST_HEAD(&hostdata->unissued);
INIT_LIST_HEAD(&hostdata->disconnected);
hostdata->flags = flags;
INIT_WORK(&hostdata->main_task, NCR5380_main);
hostdata->work_q = alloc_workqueue("ncr5380_%d",
WQ_UNBOUND | WQ_MEM_RECLAIM,
1, instance->host_no);
if (!hostdata->work_q)
return -ENOMEM;
snprintf(hostdata->info, sizeof(hostdata->info),
"%s, irq %d, io_port 0x%lx, base 0x%lx, can_queue %d, cmd_per_lun %d, sg_tablesize %d, this_id %d, flags { %s%s%s}",
instance->hostt->name, instance->irq, hostdata->io_port,
hostdata->base, instance->can_queue, instance->cmd_per_lun,
instance->sg_tablesize, instance->this_id,
hostdata->flags & FLAG_DMA_FIXUP ? "DMA_FIXUP " : "",
hostdata->flags & FLAG_NO_PSEUDO_DMA ? "NO_PSEUDO_DMA " : "",
hostdata->flags & FLAG_TOSHIBA_DELAY ? "TOSHIBA_DELAY " : "");
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
NCR5380_write(MODE_REG, MR_BASE);
NCR5380_write(TARGET_COMMAND_REG, 0);
NCR5380_write(SELECT_ENABLE_REG, 0);
/* Calibrate register polling loop */
i = 0;
deadline = jiffies + 1;
do {
cpu_relax();
} while (time_is_after_jiffies(deadline));
deadline += msecs_to_jiffies(256);
do {
NCR5380_read(STATUS_REG);
++i;
cpu_relax();
} while (time_is_after_jiffies(deadline));
accesses_per_ms = i / 256;
hostdata->poll_loops = NCR5380_REG_POLL_TIME * accesses_per_ms / 2;
return 0;
}
/**
* NCR5380_maybe_reset_bus - Detect and correct bus wedge problems.
* @instance: adapter to check
*
* If the system crashed, it may have crashed with a connected target and
* the SCSI bus busy. Check for BUS FREE phase. If not, try to abort the
* currently established nexus, which we know nothing about. Failing that
* do a bus reset.
*
* Note that a bus reset will cause the chip to assert IRQ.
*
* Returns 0 if successful, otherwise -ENXIO.
*/
static int NCR5380_maybe_reset_bus(struct Scsi_Host *instance)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
int pass;
for (pass = 1; (NCR5380_read(STATUS_REG) & SR_BSY) && pass <= 6; ++pass) {
switch (pass) {
case 1:
case 3:
case 5:
shost_printk(KERN_ERR, instance, "SCSI bus busy, waiting up to five seconds\n");
NCR5380_poll_politely(hostdata,
STATUS_REG, SR_BSY, 0, 5 * HZ);
break;
case 2:
shost_printk(KERN_ERR, instance, "bus busy, attempting abort\n");
do_abort(instance);
break;
case 4:
shost_printk(KERN_ERR, instance, "bus busy, attempting reset\n");
do_reset(instance);
/* Wait after a reset; the SCSI standard calls for
* 250ms, we wait 500ms to be on the safe side.
* But some Toshiba CD-ROMs need ten times that.
*/
if (hostdata->flags & FLAG_TOSHIBA_DELAY)
msleep(2500);
else
msleep(500);
break;
case 6:
shost_printk(KERN_ERR, instance, "bus locked solid\n");
return -ENXIO;
}
}
return 0;
}
/**
* NCR5380_exit - remove an NCR5380
* @instance: adapter to remove
*
* Assumes that no more work can be queued (e.g. by NCR5380_intr).
*/
static void NCR5380_exit(struct Scsi_Host *instance)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
cancel_work_sync(&hostdata->main_task);
destroy_workqueue(hostdata->work_q);
}
/**
* complete_cmd - finish processing a command and return it to the SCSI ML
* @instance: the host instance
* @cmd: command to complete
*/
static void complete_cmd(struct Scsi_Host *instance,
struct scsi_cmnd *cmd)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
dsprintk(NDEBUG_QUEUES, instance, "complete_cmd: cmd %p\n", cmd);
ncr5380: Fix autosense bugs NCR5380_information_transfer() may re-queue a command for autosense, after calling scsi_eh_prep_cmnd(). This creates several possibilities: 1. Reselection may intervene before the re-queued command gets processed. If the reconnected command then undergoes autosense, this causes the scsi_eh_save data from the previous command to be overwritten. 2. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(), a new REQUEST SENSE command may arrive. This would be queued ahead of any command already undergoing autosense, which means the scsi_eh_save data might be restored to the wrong command. 3. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(), eh_abort_handler() may abort the command. But the scsi_eh_save data is not discarded, which means the scsi_eh_save data might be incorrectly restored to the next REQUEST SENSE command issued. This patch adds a new autosense list so that commands that are re-queued because of a CHECK CONDITION result can be kept apart from the REQUEST SENSE commands that arrive via queuecommand. This patch also adds a function dedicated to dequeueing and preparing the next command for processing. By refactoring the main loop in this way, scsi_eh_save takes place when an autosense command is dequeued rather than when re-queued. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:06:00 +08:00
if (hostdata->sensing == cmd) {
/* Autosense processing ends here */
if (status_byte(cmd->result) != GOOD) {
ncr5380: Fix autosense bugs NCR5380_information_transfer() may re-queue a command for autosense, after calling scsi_eh_prep_cmnd(). This creates several possibilities: 1. Reselection may intervene before the re-queued command gets processed. If the reconnected command then undergoes autosense, this causes the scsi_eh_save data from the previous command to be overwritten. 2. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(), a new REQUEST SENSE command may arrive. This would be queued ahead of any command already undergoing autosense, which means the scsi_eh_save data might be restored to the wrong command. 3. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(), eh_abort_handler() may abort the command. But the scsi_eh_save data is not discarded, which means the scsi_eh_save data might be incorrectly restored to the next REQUEST SENSE command issued. This patch adds a new autosense list so that commands that are re-queued because of a CHECK CONDITION result can be kept apart from the REQUEST SENSE commands that arrive via queuecommand. This patch also adds a function dedicated to dequeueing and preparing the next command for processing. By refactoring the main loop in this way, scsi_eh_save takes place when an autosense command is dequeued rather than when re-queued. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:06:00 +08:00
scsi_eh_restore_cmnd(cmd, &hostdata->ses);
} else {
ncr5380: Fix autosense bugs NCR5380_information_transfer() may re-queue a command for autosense, after calling scsi_eh_prep_cmnd(). This creates several possibilities: 1. Reselection may intervene before the re-queued command gets processed. If the reconnected command then undergoes autosense, this causes the scsi_eh_save data from the previous command to be overwritten. 2. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(), a new REQUEST SENSE command may arrive. This would be queued ahead of any command already undergoing autosense, which means the scsi_eh_save data might be restored to the wrong command. 3. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(), eh_abort_handler() may abort the command. But the scsi_eh_save data is not discarded, which means the scsi_eh_save data might be incorrectly restored to the next REQUEST SENSE command issued. This patch adds a new autosense list so that commands that are re-queued because of a CHECK CONDITION result can be kept apart from the REQUEST SENSE commands that arrive via queuecommand. This patch also adds a function dedicated to dequeueing and preparing the next command for processing. By refactoring the main loop in this way, scsi_eh_save takes place when an autosense command is dequeued rather than when re-queued. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:06:00 +08:00
scsi_eh_restore_cmnd(cmd, &hostdata->ses);
set_driver_byte(cmd, DRIVER_SENSE);
}
ncr5380: Fix autosense bugs NCR5380_information_transfer() may re-queue a command for autosense, after calling scsi_eh_prep_cmnd(). This creates several possibilities: 1. Reselection may intervene before the re-queued command gets processed. If the reconnected command then undergoes autosense, this causes the scsi_eh_save data from the previous command to be overwritten. 2. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(), a new REQUEST SENSE command may arrive. This would be queued ahead of any command already undergoing autosense, which means the scsi_eh_save data might be restored to the wrong command. 3. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(), eh_abort_handler() may abort the command. But the scsi_eh_save data is not discarded, which means the scsi_eh_save data might be incorrectly restored to the next REQUEST SENSE command issued. This patch adds a new autosense list so that commands that are re-queued because of a CHECK CONDITION result can be kept apart from the REQUEST SENSE commands that arrive via queuecommand. This patch also adds a function dedicated to dequeueing and preparing the next command for processing. By refactoring the main loop in this way, scsi_eh_save takes place when an autosense command is dequeued rather than when re-queued. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:06:00 +08:00
hostdata->sensing = NULL;
}
cmd->scsi_done(cmd);
}
/**
* NCR5380_queue_command - queue a command
* @instance: the relevant SCSI adapter
* @cmd: SCSI command
*
* cmd is added to the per-instance issue queue, with minor
* twiddling done to the host specific fields of cmd. If the
* main coroutine is not running, it is restarted.
*/
static int NCR5380_queue_command(struct Scsi_Host *instance,
struct scsi_cmnd *cmd)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
unsigned long flags;
#if (NDEBUG & NDEBUG_NO_WRITE)
switch (cmd->cmnd[0]) {
case WRITE_6:
case WRITE_10:
shost_printk(KERN_DEBUG, instance, "WRITE attempted with NDEBUG_NO_WRITE set\n");
cmd->result = (DID_ERROR << 16);
cmd->scsi_done(cmd);
return 0;
}
#endif /* (NDEBUG & NDEBUG_NO_WRITE) */
cmd->result = 0;
if (!NCR5380_acquire_dma_irq(instance))
return SCSI_MLQUEUE_HOST_BUSY;
ncr5380: Change instance->host_lock to hostdata->lock NCR5380.c presently uses the instance->host_lock spin lock. Convert this to a new spin lock that protects the NCR5380_hostdata struct. atari_NCR5380.c previously used local_irq_save/restore() rather than a spin lock. Convert this to hostdata->lock in irq mode. For SMP platforms, the interrupt handler now also acquires the spin lock. This brings all locking in the two core drivers into agreement. Adding this locking also means that a bunch of volatile qualifiers can be removed from the members of the NCR5380_hostdata struct. This is done in a subsequent patch. Proper locking will allow the abort handler to locate a command being aborted. This is presently impossible if the abort handler is invoked when the command has been moved from a queue to a pointer on the stack. (If eh_abort_handler can't determine whether a command has been completed or is still being processed then it can't decide whether to return success or failure.) The hostdata spin lock is now held when calling NCR5380_select() and NCR5380_information_transfer(). Where possible, the lock is dropped for polling and PIO transfers. Clean up the now-redundant SELECT_ENABLE_REG writes, that used to provide limited mutual exclusion between information_transfer() and reselect(). Accessing hostdata->connected without data races means taking the lock; cleanup these accesses. The new spin lock falls away for m68k and other UP builds, so this should have little impact there. In the SMP case the new lock should be uncontested even when the SCSI bus is contested. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:51 +08:00
spin_lock_irqsave(&hostdata->lock, flags);
/*
* Insert the cmd into the issue queue. Note that REQUEST SENSE
* commands are added to the head of the queue since any command will
* clear the contingent allegiance condition that exists and the
* sense data is only guaranteed to be valid while the condition exists.
*/
if (cmd->cmnd[0] == REQUEST_SENSE)
list_add(&ncmd->list, &hostdata->unissued);
else
list_add_tail(&ncmd->list, &hostdata->unissued);
ncr5380: Change instance->host_lock to hostdata->lock NCR5380.c presently uses the instance->host_lock spin lock. Convert this to a new spin lock that protects the NCR5380_hostdata struct. atari_NCR5380.c previously used local_irq_save/restore() rather than a spin lock. Convert this to hostdata->lock in irq mode. For SMP platforms, the interrupt handler now also acquires the spin lock. This brings all locking in the two core drivers into agreement. Adding this locking also means that a bunch of volatile qualifiers can be removed from the members of the NCR5380_hostdata struct. This is done in a subsequent patch. Proper locking will allow the abort handler to locate a command being aborted. This is presently impossible if the abort handler is invoked when the command has been moved from a queue to a pointer on the stack. (If eh_abort_handler can't determine whether a command has been completed or is still being processed then it can't decide whether to return success or failure.) The hostdata spin lock is now held when calling NCR5380_select() and NCR5380_information_transfer(). Where possible, the lock is dropped for polling and PIO transfers. Clean up the now-redundant SELECT_ENABLE_REG writes, that used to provide limited mutual exclusion between information_transfer() and reselect(). Accessing hostdata->connected without data races means taking the lock; cleanup these accesses. The new spin lock falls away for m68k and other UP builds, so this should have little impact there. In the SMP case the new lock should be uncontested even when the SCSI bus is contested. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:51 +08:00
spin_unlock_irqrestore(&hostdata->lock, flags);
dsprintk(NDEBUG_QUEUES, instance, "command %p added to %s of queue\n",
cmd, (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail");
/* Kick off command processing */
queue_work(hostdata->work_q, &hostdata->main_task);
return 0;
}
static inline void maybe_release_dma_irq(struct Scsi_Host *instance)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
/* Caller does the locking needed to set & test these data atomically */
if (list_empty(&hostdata->disconnected) &&
list_empty(&hostdata->unissued) &&
list_empty(&hostdata->autosense) &&
!hostdata->connected &&
!hostdata->selecting) {
NCR5380_release_dma_irq(instance);
}
}
ncr5380: Fix autosense bugs NCR5380_information_transfer() may re-queue a command for autosense, after calling scsi_eh_prep_cmnd(). This creates several possibilities: 1. Reselection may intervene before the re-queued command gets processed. If the reconnected command then undergoes autosense, this causes the scsi_eh_save data from the previous command to be overwritten. 2. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(), a new REQUEST SENSE command may arrive. This would be queued ahead of any command already undergoing autosense, which means the scsi_eh_save data might be restored to the wrong command. 3. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(), eh_abort_handler() may abort the command. But the scsi_eh_save data is not discarded, which means the scsi_eh_save data might be incorrectly restored to the next REQUEST SENSE command issued. This patch adds a new autosense list so that commands that are re-queued because of a CHECK CONDITION result can be kept apart from the REQUEST SENSE commands that arrive via queuecommand. This patch also adds a function dedicated to dequeueing and preparing the next command for processing. By refactoring the main loop in this way, scsi_eh_save takes place when an autosense command is dequeued rather than when re-queued. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:06:00 +08:00
/**
* dequeue_next_cmd - dequeue a command for processing
* @instance: the scsi host instance
*
* Priority is given to commands on the autosense queue. These commands
* need autosense because of a CHECK CONDITION result.
*
* Returns a command pointer if a command is found for a target that is
* not already busy. Otherwise returns NULL.
*/
static struct scsi_cmnd *dequeue_next_cmd(struct Scsi_Host *instance)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
struct NCR5380_cmd *ncmd;
struct scsi_cmnd *cmd;
if (hostdata->sensing || list_empty(&hostdata->autosense)) {
ncr5380: Fix autosense bugs NCR5380_information_transfer() may re-queue a command for autosense, after calling scsi_eh_prep_cmnd(). This creates several possibilities: 1. Reselection may intervene before the re-queued command gets processed. If the reconnected command then undergoes autosense, this causes the scsi_eh_save data from the previous command to be overwritten. 2. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(), a new REQUEST SENSE command may arrive. This would be queued ahead of any command already undergoing autosense, which means the scsi_eh_save data might be restored to the wrong command. 3. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(), eh_abort_handler() may abort the command. But the scsi_eh_save data is not discarded, which means the scsi_eh_save data might be incorrectly restored to the next REQUEST SENSE command issued. This patch adds a new autosense list so that commands that are re-queued because of a CHECK CONDITION result can be kept apart from the REQUEST SENSE commands that arrive via queuecommand. This patch also adds a function dedicated to dequeueing and preparing the next command for processing. By refactoring the main loop in this way, scsi_eh_save takes place when an autosense command is dequeued rather than when re-queued. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:06:00 +08:00
list_for_each_entry(ncmd, &hostdata->unissued, list) {
cmd = NCR5380_to_scmd(ncmd);
dsprintk(NDEBUG_QUEUES, instance, "dequeue: cmd=%p target=%d busy=0x%02x lun=%llu\n",
cmd, scmd_id(cmd), hostdata->busy[scmd_id(cmd)], cmd->device->lun);
if (!(hostdata->busy[scmd_id(cmd)] & (1 << cmd->device->lun))) {
list_del(&ncmd->list);
dsprintk(NDEBUG_QUEUES, instance,
"dequeue: removed %p from issue queue\n", cmd);
return cmd;
}
}
} else {
/* Autosense processing begins here */
ncmd = list_first_entry(&hostdata->autosense,
struct NCR5380_cmd, list);
list_del(&ncmd->list);
cmd = NCR5380_to_scmd(ncmd);
dsprintk(NDEBUG_QUEUES, instance,
"dequeue: removed %p from autosense queue\n", cmd);
scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0);
hostdata->sensing = cmd;
return cmd;
}
return NULL;
}
static void requeue_cmd(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
if (hostdata->sensing == cmd) {
ncr5380: Fix autosense bugs NCR5380_information_transfer() may re-queue a command for autosense, after calling scsi_eh_prep_cmnd(). This creates several possibilities: 1. Reselection may intervene before the re-queued command gets processed. If the reconnected command then undergoes autosense, this causes the scsi_eh_save data from the previous command to be overwritten. 2. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(), a new REQUEST SENSE command may arrive. This would be queued ahead of any command already undergoing autosense, which means the scsi_eh_save data might be restored to the wrong command. 3. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(), eh_abort_handler() may abort the command. But the scsi_eh_save data is not discarded, which means the scsi_eh_save data might be incorrectly restored to the next REQUEST SENSE command issued. This patch adds a new autosense list so that commands that are re-queued because of a CHECK CONDITION result can be kept apart from the REQUEST SENSE commands that arrive via queuecommand. This patch also adds a function dedicated to dequeueing and preparing the next command for processing. By refactoring the main loop in this way, scsi_eh_save takes place when an autosense command is dequeued rather than when re-queued. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:06:00 +08:00
scsi_eh_restore_cmnd(cmd, &hostdata->ses);
list_add(&ncmd->list, &hostdata->autosense);
hostdata->sensing = NULL;
} else
list_add(&ncmd->list, &hostdata->unissued);
}
/**
* NCR5380_main - NCR state machines
*
* NCR5380_main is a coroutine that runs as long as more work can
* be done on the NCR5380 host adapters in a system. Both
* NCR5380_queue_command() and NCR5380_intr() will try to start it
* in case it is not running.
*/
static void NCR5380_main(struct work_struct *work)
{
struct NCR5380_hostdata *hostdata =
container_of(work, struct NCR5380_hostdata, main_task);
struct Scsi_Host *instance = hostdata->host;
int done;
do {
done = 1;
ncr5380: Change instance->host_lock to hostdata->lock NCR5380.c presently uses the instance->host_lock spin lock. Convert this to a new spin lock that protects the NCR5380_hostdata struct. atari_NCR5380.c previously used local_irq_save/restore() rather than a spin lock. Convert this to hostdata->lock in irq mode. For SMP platforms, the interrupt handler now also acquires the spin lock. This brings all locking in the two core drivers into agreement. Adding this locking also means that a bunch of volatile qualifiers can be removed from the members of the NCR5380_hostdata struct. This is done in a subsequent patch. Proper locking will allow the abort handler to locate a command being aborted. This is presently impossible if the abort handler is invoked when the command has been moved from a queue to a pointer on the stack. (If eh_abort_handler can't determine whether a command has been completed or is still being processed then it can't decide whether to return success or failure.) The hostdata spin lock is now held when calling NCR5380_select() and NCR5380_information_transfer(). Where possible, the lock is dropped for polling and PIO transfers. Clean up the now-redundant SELECT_ENABLE_REG writes, that used to provide limited mutual exclusion between information_transfer() and reselect(). Accessing hostdata->connected without data races means taking the lock; cleanup these accesses. The new spin lock falls away for m68k and other UP builds, so this should have little impact there. In the SMP case the new lock should be uncontested even when the SCSI bus is contested. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:51 +08:00
spin_lock_irq(&hostdata->lock);
while (!hostdata->connected && !hostdata->selecting) {
struct scsi_cmnd *cmd = dequeue_next_cmd(instance);
if (!cmd)
break;
ncr5380: Fix autosense bugs NCR5380_information_transfer() may re-queue a command for autosense, after calling scsi_eh_prep_cmnd(). This creates several possibilities: 1. Reselection may intervene before the re-queued command gets processed. If the reconnected command then undergoes autosense, this causes the scsi_eh_save data from the previous command to be overwritten. 2. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(), a new REQUEST SENSE command may arrive. This would be queued ahead of any command already undergoing autosense, which means the scsi_eh_save data might be restored to the wrong command. 3. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(), eh_abort_handler() may abort the command. But the scsi_eh_save data is not discarded, which means the scsi_eh_save data might be incorrectly restored to the next REQUEST SENSE command issued. This patch adds a new autosense list so that commands that are re-queued because of a CHECK CONDITION result can be kept apart from the REQUEST SENSE commands that arrive via queuecommand. This patch also adds a function dedicated to dequeueing and preparing the next command for processing. By refactoring the main loop in this way, scsi_eh_save takes place when an autosense command is dequeued rather than when re-queued. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:06:00 +08:00
dsprintk(NDEBUG_MAIN, instance, "main: dequeued %p\n", cmd);
ncr5380: Fix autosense bugs NCR5380_information_transfer() may re-queue a command for autosense, after calling scsi_eh_prep_cmnd(). This creates several possibilities: 1. Reselection may intervene before the re-queued command gets processed. If the reconnected command then undergoes autosense, this causes the scsi_eh_save data from the previous command to be overwritten. 2. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(), a new REQUEST SENSE command may arrive. This would be queued ahead of any command already undergoing autosense, which means the scsi_eh_save data might be restored to the wrong command. 3. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(), eh_abort_handler() may abort the command. But the scsi_eh_save data is not discarded, which means the scsi_eh_save data might be incorrectly restored to the next REQUEST SENSE command issued. This patch adds a new autosense list so that commands that are re-queued because of a CHECK CONDITION result can be kept apart from the REQUEST SENSE commands that arrive via queuecommand. This patch also adds a function dedicated to dequeueing and preparing the next command for processing. By refactoring the main loop in this way, scsi_eh_save takes place when an autosense command is dequeued rather than when re-queued. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:06:00 +08:00
/*
* Attempt to establish an I_T_L nexus here.
* On success, instance->hostdata->connected is set.
* On failure, we must add the command back to the
* issue queue so we can keep trying.
*/
/*
* REQUEST SENSE commands are issued without tagged
* queueing, even on SCSI-II devices because the
* contingent allegiance condition exists for the
* entire unit.
*/
ncr5380: Change instance->host_lock to hostdata->lock NCR5380.c presently uses the instance->host_lock spin lock. Convert this to a new spin lock that protects the NCR5380_hostdata struct. atari_NCR5380.c previously used local_irq_save/restore() rather than a spin lock. Convert this to hostdata->lock in irq mode. For SMP platforms, the interrupt handler now also acquires the spin lock. This brings all locking in the two core drivers into agreement. Adding this locking also means that a bunch of volatile qualifiers can be removed from the members of the NCR5380_hostdata struct. This is done in a subsequent patch. Proper locking will allow the abort handler to locate a command being aborted. This is presently impossible if the abort handler is invoked when the command has been moved from a queue to a pointer on the stack. (If eh_abort_handler can't determine whether a command has been completed or is still being processed then it can't decide whether to return success or failure.) The hostdata spin lock is now held when calling NCR5380_select() and NCR5380_information_transfer(). Where possible, the lock is dropped for polling and PIO transfers. Clean up the now-redundant SELECT_ENABLE_REG writes, that used to provide limited mutual exclusion between information_transfer() and reselect(). Accessing hostdata->connected without data races means taking the lock; cleanup these accesses. The new spin lock falls away for m68k and other UP builds, so this should have little impact there. In the SMP case the new lock should be uncontested even when the SCSI bus is contested. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:51 +08:00
if (!NCR5380_select(instance, cmd)) {
dsprintk(NDEBUG_MAIN, instance, "main: select complete\n");
maybe_release_dma_irq(instance);
ncr5380: Fix autosense bugs NCR5380_information_transfer() may re-queue a command for autosense, after calling scsi_eh_prep_cmnd(). This creates several possibilities: 1. Reselection may intervene before the re-queued command gets processed. If the reconnected command then undergoes autosense, this causes the scsi_eh_save data from the previous command to be overwritten. 2. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(), a new REQUEST SENSE command may arrive. This would be queued ahead of any command already undergoing autosense, which means the scsi_eh_save data might be restored to the wrong command. 3. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(), eh_abort_handler() may abort the command. But the scsi_eh_save data is not discarded, which means the scsi_eh_save data might be incorrectly restored to the next REQUEST SENSE command issued. This patch adds a new autosense list so that commands that are re-queued because of a CHECK CONDITION result can be kept apart from the REQUEST SENSE commands that arrive via queuecommand. This patch also adds a function dedicated to dequeueing and preparing the next command for processing. By refactoring the main loop in this way, scsi_eh_save takes place when an autosense command is dequeued rather than when re-queued. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:06:00 +08:00
} else {
dsprintk(NDEBUG_MAIN | NDEBUG_QUEUES, instance,
"main: select failed, returning %p to queue\n", cmd);
requeue_cmd(instance, cmd);
}
}
if (hostdata->connected && !hostdata->dma_len) {
dsprintk(NDEBUG_MAIN, instance, "main: performing information transfer\n");
NCR5380_information_transfer(instance);
done = 0;
}
if (!hostdata->connected)
NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
spin_unlock_irq(&hostdata->lock);
if (!done)
cond_resched();
} while (!done);
}
/*
* NCR5380_dma_complete - finish DMA transfer
* @instance: the scsi host instance
*
* Called by the interrupt handler when DMA finishes or a phase
* mismatch occurs (which would end the DMA transfer).
*/
static void NCR5380_dma_complete(struct Scsi_Host *instance)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
int transferred;
unsigned char **data;
int *count;
int saved_data = 0, overrun = 0;
unsigned char p;
if (hostdata->read_overruns) {
p = hostdata->connected->SCp.phase;
if (p & SR_IO) {
udelay(10);
if ((NCR5380_read(BUS_AND_STATUS_REG) &
(BASR_PHASE_MATCH | BASR_ACK)) ==
(BASR_PHASE_MATCH | BASR_ACK)) {
saved_data = NCR5380_read(INPUT_DATA_REG);
overrun = 1;
dsprintk(NDEBUG_DMA, instance, "read overrun handled\n");
}
}
}
#ifdef CONFIG_SUN3
if ((sun3scsi_dma_finish(rq_data_dir(hostdata->connected->request)))) {
pr_err("scsi%d: overrun in UDC counter -- not prepared to deal with this!\n",
instance->host_no);
BUG();
}
if ((NCR5380_read(BUS_AND_STATUS_REG) & (BASR_PHASE_MATCH | BASR_ACK)) ==
(BASR_PHASE_MATCH | BASR_ACK)) {
pr_err("scsi%d: BASR %02x\n", instance->host_no,
NCR5380_read(BUS_AND_STATUS_REG));
pr_err("scsi%d: bus stuck in data phase -- probably a single byte overrun!\n",
instance->host_no);
BUG();
}
#endif
NCR5380_write(MODE_REG, MR_BASE);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
NCR5380_read(RESET_PARITY_INTERRUPT_REG);
transferred = hostdata->dma_len - NCR5380_dma_residual(hostdata);
hostdata->dma_len = 0;
data = (unsigned char **)&hostdata->connected->SCp.ptr;
count = &hostdata->connected->SCp.this_residual;
*data += transferred;
*count -= transferred;
if (hostdata->read_overruns) {
int cnt, toPIO;
if ((NCR5380_read(STATUS_REG) & PHASE_MASK) == p && (p & SR_IO)) {
cnt = toPIO = hostdata->read_overruns;
if (overrun) {
dsprintk(NDEBUG_DMA, instance,
"Got an input overrun, using saved byte\n");
*(*data)++ = saved_data;
(*count)--;
cnt--;
toPIO--;
}
if (toPIO > 0) {
dsprintk(NDEBUG_DMA, instance,
"Doing %d byte PIO to 0x%p\n", cnt, *data);
NCR5380_transfer_pio(instance, &p, &cnt, data);
*count -= toPIO - cnt;
}
}
}
}
/**
ncr5380: Standardize interrupt handling Because interrupt handling is crucial to the core driver(s), all wrapper drivers need to agree on this code. This patch removes discrepancies. NCR5380_intr() in NCR5380.c has the following pointless loop that differs from the code in atari_NCR5380.c. done = 1; do { /* ... */ } while (!done); The 'done' flag gets cleared when a reconnected command is to be processed from the work queue. But in NCR5380.c, the flag is also used to cause the interrupt conditions to be re-examined. Perhaps this was because NCR5380_reselect() was expected to cause another interrupt, or perhaps the remaining present interrupt conditions need to be handled after the NCR5380_reselect() call? Actually, both possibilities are bogus, as is the loop itself. It seems have been overlooked in the hit-and-miss removal of scsi host instance list iteration many years ago; see history/history.git commit 491447e1fcff ("[PATCH] next NCR5380 updates") and commit 69e1a9482e57 ("[PATCH] fix up NCR5380 private data"). See also my earlier patch, "Always retry arbitration and selection". The datasheet says, "IRQ can be reset simply by reading the Reset Parity/Interrupt Register". So don't treat the chip IRQ like a level-triggered interrupt. Of the conditions that set the IRQ flag, some are level-triggered and some are edge-triggered, which means IRQ itself must be edge-triggered. Some interrupt conditions are latched and some are not. Before clearing the chip IRQ flag, clear all state that may cause it to be raised. That means clearing the DMA Mode and Busy Monitor bits in the Mode Register and clearing the host ID in the Select Enable register. Also clean up some printk's and some comments. Keep atari_NCR5380.c and NCR5380.c in agreement. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:40 +08:00
* NCR5380_intr - generic NCR5380 irq handler
* @irq: interrupt number
* @dev_id: device info
*
* Handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
* from the disconnected queue, and restarting NCR5380_main()
* as required.
*
* The chip can assert IRQ in any of six different conditions. The IRQ flag
* is then cleared by reading the Reset Parity/Interrupt Register (RPIR).
* Three of these six conditions are latched in the Bus and Status Register:
* - End of DMA (cleared by ending DMA Mode)
* - Parity error (cleared by reading RPIR)
* - Loss of BSY (cleared by reading RPIR)
* Two conditions have flag bits that are not latched:
* - Bus phase mismatch (non-maskable in DMA Mode, cleared by ending DMA Mode)
* - Bus reset (non-maskable)
* The remaining condition has no flag bit at all:
* - Selection/reselection
*
* Hence, establishing the cause(s) of any interrupt is partly guesswork.
* In "The DP8490 and DP5380 Comparison Guide", National Semiconductor
* claimed that "the design of the [DP8490] interrupt logic ensures
* interrupts will not be lost (they can be on the DP5380)."
* The L5380/53C80 datasheet from LOGIC Devices has more details.
*
* Checking for bus reset by reading RST is futile because of interrupt
* latency, but a bus reset will reset chip logic. Checking for parity error
* is unnecessary because that interrupt is never enabled. A Loss of BSY
* condition will clear DMA Mode. We can tell when this occurs because the
* the Busy Monitor interrupt is enabled together with DMA Mode.
*/
static irqreturn_t __maybe_unused NCR5380_intr(int irq, void *dev_id)
{
struct Scsi_Host *instance = dev_id;
ncr5380: Standardize interrupt handling Because interrupt handling is crucial to the core driver(s), all wrapper drivers need to agree on this code. This patch removes discrepancies. NCR5380_intr() in NCR5380.c has the following pointless loop that differs from the code in atari_NCR5380.c. done = 1; do { /* ... */ } while (!done); The 'done' flag gets cleared when a reconnected command is to be processed from the work queue. But in NCR5380.c, the flag is also used to cause the interrupt conditions to be re-examined. Perhaps this was because NCR5380_reselect() was expected to cause another interrupt, or perhaps the remaining present interrupt conditions need to be handled after the NCR5380_reselect() call? Actually, both possibilities are bogus, as is the loop itself. It seems have been overlooked in the hit-and-miss removal of scsi host instance list iteration many years ago; see history/history.git commit 491447e1fcff ("[PATCH] next NCR5380 updates") and commit 69e1a9482e57 ("[PATCH] fix up NCR5380 private data"). See also my earlier patch, "Always retry arbitration and selection". The datasheet says, "IRQ can be reset simply by reading the Reset Parity/Interrupt Register". So don't treat the chip IRQ like a level-triggered interrupt. Of the conditions that set the IRQ flag, some are level-triggered and some are edge-triggered, which means IRQ itself must be edge-triggered. Some interrupt conditions are latched and some are not. Before clearing the chip IRQ flag, clear all state that may cause it to be raised. That means clearing the DMA Mode and Busy Monitor bits in the Mode Register and clearing the host ID in the Select Enable register. Also clean up some printk's and some comments. Keep atari_NCR5380.c and NCR5380.c in agreement. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:40 +08:00
struct NCR5380_hostdata *hostdata = shost_priv(instance);
int handled = 0;
unsigned char basr;
unsigned long flags;
ncr5380: Change instance->host_lock to hostdata->lock NCR5380.c presently uses the instance->host_lock spin lock. Convert this to a new spin lock that protects the NCR5380_hostdata struct. atari_NCR5380.c previously used local_irq_save/restore() rather than a spin lock. Convert this to hostdata->lock in irq mode. For SMP platforms, the interrupt handler now also acquires the spin lock. This brings all locking in the two core drivers into agreement. Adding this locking also means that a bunch of volatile qualifiers can be removed from the members of the NCR5380_hostdata struct. This is done in a subsequent patch. Proper locking will allow the abort handler to locate a command being aborted. This is presently impossible if the abort handler is invoked when the command has been moved from a queue to a pointer on the stack. (If eh_abort_handler can't determine whether a command has been completed or is still being processed then it can't decide whether to return success or failure.) The hostdata spin lock is now held when calling NCR5380_select() and NCR5380_information_transfer(). Where possible, the lock is dropped for polling and PIO transfers. Clean up the now-redundant SELECT_ENABLE_REG writes, that used to provide limited mutual exclusion between information_transfer() and reselect(). Accessing hostdata->connected without data races means taking the lock; cleanup these accesses. The new spin lock falls away for m68k and other UP builds, so this should have little impact there. In the SMP case the new lock should be uncontested even when the SCSI bus is contested. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:51 +08:00
spin_lock_irqsave(&hostdata->lock, flags);
ncr5380: Standardize interrupt handling Because interrupt handling is crucial to the core driver(s), all wrapper drivers need to agree on this code. This patch removes discrepancies. NCR5380_intr() in NCR5380.c has the following pointless loop that differs from the code in atari_NCR5380.c. done = 1; do { /* ... */ } while (!done); The 'done' flag gets cleared when a reconnected command is to be processed from the work queue. But in NCR5380.c, the flag is also used to cause the interrupt conditions to be re-examined. Perhaps this was because NCR5380_reselect() was expected to cause another interrupt, or perhaps the remaining present interrupt conditions need to be handled after the NCR5380_reselect() call? Actually, both possibilities are bogus, as is the loop itself. It seems have been overlooked in the hit-and-miss removal of scsi host instance list iteration many years ago; see history/history.git commit 491447e1fcff ("[PATCH] next NCR5380 updates") and commit 69e1a9482e57 ("[PATCH] fix up NCR5380 private data"). See also my earlier patch, "Always retry arbitration and selection". The datasheet says, "IRQ can be reset simply by reading the Reset Parity/Interrupt Register". So don't treat the chip IRQ like a level-triggered interrupt. Of the conditions that set the IRQ flag, some are level-triggered and some are edge-triggered, which means IRQ itself must be edge-triggered. Some interrupt conditions are latched and some are not. Before clearing the chip IRQ flag, clear all state that may cause it to be raised. That means clearing the DMA Mode and Busy Monitor bits in the Mode Register and clearing the host ID in the Select Enable register. Also clean up some printk's and some comments. Keep atari_NCR5380.c and NCR5380.c in agreement. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:40 +08:00
basr = NCR5380_read(BUS_AND_STATUS_REG);
if (basr & BASR_IRQ) {
unsigned char mr = NCR5380_read(MODE_REG);
unsigned char sr = NCR5380_read(STATUS_REG);
dsprintk(NDEBUG_INTR, instance, "IRQ %d, BASR 0x%02x, SR 0x%02x, MR 0x%02x\n",
irq, basr, sr, mr);
if ((mr & MR_DMA_MODE) || (mr & MR_MONITOR_BSY)) {
/* Probably End of DMA, Phase Mismatch or Loss of BSY.
* We ack IRQ after clearing Mode Register. Workarounds
* for End of DMA errata need to happen in DMA Mode.
*/
dsprintk(NDEBUG_INTR, instance, "interrupt in DMA mode\n");
if (hostdata->connected) {
NCR5380_dma_complete(instance);
queue_work(hostdata->work_q, &hostdata->main_task);
} else {
NCR5380_write(MODE_REG, MR_BASE);
NCR5380_read(RESET_PARITY_INTERRUPT_REG);
}
} else if ((NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_mask) &&
ncr5380: Standardize interrupt handling Because interrupt handling is crucial to the core driver(s), all wrapper drivers need to agree on this code. This patch removes discrepancies. NCR5380_intr() in NCR5380.c has the following pointless loop that differs from the code in atari_NCR5380.c. done = 1; do { /* ... */ } while (!done); The 'done' flag gets cleared when a reconnected command is to be processed from the work queue. But in NCR5380.c, the flag is also used to cause the interrupt conditions to be re-examined. Perhaps this was because NCR5380_reselect() was expected to cause another interrupt, or perhaps the remaining present interrupt conditions need to be handled after the NCR5380_reselect() call? Actually, both possibilities are bogus, as is the loop itself. It seems have been overlooked in the hit-and-miss removal of scsi host instance list iteration many years ago; see history/history.git commit 491447e1fcff ("[PATCH] next NCR5380 updates") and commit 69e1a9482e57 ("[PATCH] fix up NCR5380 private data"). See also my earlier patch, "Always retry arbitration and selection". The datasheet says, "IRQ can be reset simply by reading the Reset Parity/Interrupt Register". So don't treat the chip IRQ like a level-triggered interrupt. Of the conditions that set the IRQ flag, some are level-triggered and some are edge-triggered, which means IRQ itself must be edge-triggered. Some interrupt conditions are latched and some are not. Before clearing the chip IRQ flag, clear all state that may cause it to be raised. That means clearing the DMA Mode and Busy Monitor bits in the Mode Register and clearing the host ID in the Select Enable register. Also clean up some printk's and some comments. Keep atari_NCR5380.c and NCR5380.c in agreement. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:40 +08:00
(sr & (SR_SEL | SR_IO | SR_BSY | SR_RST)) == (SR_SEL | SR_IO)) {
/* Probably reselected */
NCR5380_write(SELECT_ENABLE_REG, 0);
NCR5380_read(RESET_PARITY_INTERRUPT_REG);
dsprintk(NDEBUG_INTR, instance, "interrupt with SEL and IO\n");
ncr5380: Standardize interrupt handling Because interrupt handling is crucial to the core driver(s), all wrapper drivers need to agree on this code. This patch removes discrepancies. NCR5380_intr() in NCR5380.c has the following pointless loop that differs from the code in atari_NCR5380.c. done = 1; do { /* ... */ } while (!done); The 'done' flag gets cleared when a reconnected command is to be processed from the work queue. But in NCR5380.c, the flag is also used to cause the interrupt conditions to be re-examined. Perhaps this was because NCR5380_reselect() was expected to cause another interrupt, or perhaps the remaining present interrupt conditions need to be handled after the NCR5380_reselect() call? Actually, both possibilities are bogus, as is the loop itself. It seems have been overlooked in the hit-and-miss removal of scsi host instance list iteration many years ago; see history/history.git commit 491447e1fcff ("[PATCH] next NCR5380 updates") and commit 69e1a9482e57 ("[PATCH] fix up NCR5380 private data"). See also my earlier patch, "Always retry arbitration and selection". The datasheet says, "IRQ can be reset simply by reading the Reset Parity/Interrupt Register". So don't treat the chip IRQ like a level-triggered interrupt. Of the conditions that set the IRQ flag, some are level-triggered and some are edge-triggered, which means IRQ itself must be edge-triggered. Some interrupt conditions are latched and some are not. Before clearing the chip IRQ flag, clear all state that may cause it to be raised. That means clearing the DMA Mode and Busy Monitor bits in the Mode Register and clearing the host ID in the Select Enable register. Also clean up some printk's and some comments. Keep atari_NCR5380.c and NCR5380.c in agreement. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:40 +08:00
if (!hostdata->connected) {
NCR5380_reselect(instance);
queue_work(hostdata->work_q, &hostdata->main_task);
}
ncr5380: Standardize interrupt handling Because interrupt handling is crucial to the core driver(s), all wrapper drivers need to agree on this code. This patch removes discrepancies. NCR5380_intr() in NCR5380.c has the following pointless loop that differs from the code in atari_NCR5380.c. done = 1; do { /* ... */ } while (!done); The 'done' flag gets cleared when a reconnected command is to be processed from the work queue. But in NCR5380.c, the flag is also used to cause the interrupt conditions to be re-examined. Perhaps this was because NCR5380_reselect() was expected to cause another interrupt, or perhaps the remaining present interrupt conditions need to be handled after the NCR5380_reselect() call? Actually, both possibilities are bogus, as is the loop itself. It seems have been overlooked in the hit-and-miss removal of scsi host instance list iteration many years ago; see history/history.git commit 491447e1fcff ("[PATCH] next NCR5380 updates") and commit 69e1a9482e57 ("[PATCH] fix up NCR5380 private data"). See also my earlier patch, "Always retry arbitration and selection". The datasheet says, "IRQ can be reset simply by reading the Reset Parity/Interrupt Register". So don't treat the chip IRQ like a level-triggered interrupt. Of the conditions that set the IRQ flag, some are level-triggered and some are edge-triggered, which means IRQ itself must be edge-triggered. Some interrupt conditions are latched and some are not. Before clearing the chip IRQ flag, clear all state that may cause it to be raised. That means clearing the DMA Mode and Busy Monitor bits in the Mode Register and clearing the host ID in the Select Enable register. Also clean up some printk's and some comments. Keep atari_NCR5380.c and NCR5380.c in agreement. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:40 +08:00
if (!hostdata->connected)
NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
} else {
/* Probably Bus Reset */
NCR5380_read(RESET_PARITY_INTERRUPT_REG);
if (sr & SR_RST) {
/* Certainly Bus Reset */
shost_printk(KERN_WARNING, instance,
"bus reset interrupt\n");
bus_reset_cleanup(instance);
} else {
dsprintk(NDEBUG_INTR, instance, "unknown interrupt\n");
}
#ifdef SUN3_SCSI_VME
dregs->csr |= CSR_DMA_ENABLE;
#endif
ncr5380: Standardize interrupt handling Because interrupt handling is crucial to the core driver(s), all wrapper drivers need to agree on this code. This patch removes discrepancies. NCR5380_intr() in NCR5380.c has the following pointless loop that differs from the code in atari_NCR5380.c. done = 1; do { /* ... */ } while (!done); The 'done' flag gets cleared when a reconnected command is to be processed from the work queue. But in NCR5380.c, the flag is also used to cause the interrupt conditions to be re-examined. Perhaps this was because NCR5380_reselect() was expected to cause another interrupt, or perhaps the remaining present interrupt conditions need to be handled after the NCR5380_reselect() call? Actually, both possibilities are bogus, as is the loop itself. It seems have been overlooked in the hit-and-miss removal of scsi host instance list iteration many years ago; see history/history.git commit 491447e1fcff ("[PATCH] next NCR5380 updates") and commit 69e1a9482e57 ("[PATCH] fix up NCR5380 private data"). See also my earlier patch, "Always retry arbitration and selection". The datasheet says, "IRQ can be reset simply by reading the Reset Parity/Interrupt Register". So don't treat the chip IRQ like a level-triggered interrupt. Of the conditions that set the IRQ flag, some are level-triggered and some are edge-triggered, which means IRQ itself must be edge-triggered. Some interrupt conditions are latched and some are not. Before clearing the chip IRQ flag, clear all state that may cause it to be raised. That means clearing the DMA Mode and Busy Monitor bits in the Mode Register and clearing the host ID in the Select Enable register. Also clean up some printk's and some comments. Keep atari_NCR5380.c and NCR5380.c in agreement. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:40 +08:00
}
handled = 1;
} else {
dsprintk(NDEBUG_INTR, instance, "interrupt without IRQ bit\n");
#ifdef SUN3_SCSI_VME
dregs->csr |= CSR_DMA_ENABLE;
#endif
ncr5380: Standardize interrupt handling Because interrupt handling is crucial to the core driver(s), all wrapper drivers need to agree on this code. This patch removes discrepancies. NCR5380_intr() in NCR5380.c has the following pointless loop that differs from the code in atari_NCR5380.c. done = 1; do { /* ... */ } while (!done); The 'done' flag gets cleared when a reconnected command is to be processed from the work queue. But in NCR5380.c, the flag is also used to cause the interrupt conditions to be re-examined. Perhaps this was because NCR5380_reselect() was expected to cause another interrupt, or perhaps the remaining present interrupt conditions need to be handled after the NCR5380_reselect() call? Actually, both possibilities are bogus, as is the loop itself. It seems have been overlooked in the hit-and-miss removal of scsi host instance list iteration many years ago; see history/history.git commit 491447e1fcff ("[PATCH] next NCR5380 updates") and commit 69e1a9482e57 ("[PATCH] fix up NCR5380 private data"). See also my earlier patch, "Always retry arbitration and selection". The datasheet says, "IRQ can be reset simply by reading the Reset Parity/Interrupt Register". So don't treat the chip IRQ like a level-triggered interrupt. Of the conditions that set the IRQ flag, some are level-triggered and some are edge-triggered, which means IRQ itself must be edge-triggered. Some interrupt conditions are latched and some are not. Before clearing the chip IRQ flag, clear all state that may cause it to be raised. That means clearing the DMA Mode and Busy Monitor bits in the Mode Register and clearing the host ID in the Select Enable register. Also clean up some printk's and some comments. Keep atari_NCR5380.c and NCR5380.c in agreement. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:40 +08:00
}
ncr5380: Change instance->host_lock to hostdata->lock NCR5380.c presently uses the instance->host_lock spin lock. Convert this to a new spin lock that protects the NCR5380_hostdata struct. atari_NCR5380.c previously used local_irq_save/restore() rather than a spin lock. Convert this to hostdata->lock in irq mode. For SMP platforms, the interrupt handler now also acquires the spin lock. This brings all locking in the two core drivers into agreement. Adding this locking also means that a bunch of volatile qualifiers can be removed from the members of the NCR5380_hostdata struct. This is done in a subsequent patch. Proper locking will allow the abort handler to locate a command being aborted. This is presently impossible if the abort handler is invoked when the command has been moved from a queue to a pointer on the stack. (If eh_abort_handler can't determine whether a command has been completed or is still being processed then it can't decide whether to return success or failure.) The hostdata spin lock is now held when calling NCR5380_select() and NCR5380_information_transfer(). Where possible, the lock is dropped for polling and PIO transfers. Clean up the now-redundant SELECT_ENABLE_REG writes, that used to provide limited mutual exclusion between information_transfer() and reselect(). Accessing hostdata->connected without data races means taking the lock; cleanup these accesses. The new spin lock falls away for m68k and other UP builds, so this should have little impact there. In the SMP case the new lock should be uncontested even when the SCSI bus is contested. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:51 +08:00
spin_unlock_irqrestore(&hostdata->lock, flags);
ncr5380: Standardize interrupt handling Because interrupt handling is crucial to the core driver(s), all wrapper drivers need to agree on this code. This patch removes discrepancies. NCR5380_intr() in NCR5380.c has the following pointless loop that differs from the code in atari_NCR5380.c. done = 1; do { /* ... */ } while (!done); The 'done' flag gets cleared when a reconnected command is to be processed from the work queue. But in NCR5380.c, the flag is also used to cause the interrupt conditions to be re-examined. Perhaps this was because NCR5380_reselect() was expected to cause another interrupt, or perhaps the remaining present interrupt conditions need to be handled after the NCR5380_reselect() call? Actually, both possibilities are bogus, as is the loop itself. It seems have been overlooked in the hit-and-miss removal of scsi host instance list iteration many years ago; see history/history.git commit 491447e1fcff ("[PATCH] next NCR5380 updates") and commit 69e1a9482e57 ("[PATCH] fix up NCR5380 private data"). See also my earlier patch, "Always retry arbitration and selection". The datasheet says, "IRQ can be reset simply by reading the Reset Parity/Interrupt Register". So don't treat the chip IRQ like a level-triggered interrupt. Of the conditions that set the IRQ flag, some are level-triggered and some are edge-triggered, which means IRQ itself must be edge-triggered. Some interrupt conditions are latched and some are not. Before clearing the chip IRQ flag, clear all state that may cause it to be raised. That means clearing the DMA Mode and Busy Monitor bits in the Mode Register and clearing the host ID in the Select Enable register. Also clean up some printk's and some comments. Keep atari_NCR5380.c and NCR5380.c in agreement. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:40 +08:00
return IRQ_RETVAL(handled);
}
/**
* NCR5380_select - attempt arbitration and selection for a given command
* @instance: the Scsi_Host instance
* @cmd: the scsi_cmnd to execute
*
* This routine establishes an I_T_L nexus for a SCSI command. This involves
* ARBITRATION, SELECTION and MESSAGE OUT phases and an IDENTIFY message.
*
* Returns true if the operation should be retried.
* Returns false if it should not be retried.
*
* Side effects :
* If bus busy, arbitration failed, etc, NCR5380_select() will exit
* with registers as they should have been on entry - ie
* SELECT_ENABLE will be set appropriately, the NCR5380
* will cease to drive any SCSI bus signals.
*
* If successful : the I_T_L nexus will be established, and
* hostdata->connected will be set to cmd.
* SELECT interrupt will be disabled.
*
* If failed (no target) : cmd->scsi_done() will be called, and the
* cmd->result host byte set to DID_BAD_TARGET.
*/
static bool NCR5380_select(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
__releases(&hostdata->lock) __acquires(&hostdata->lock)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
unsigned char tmp[3], phase;
unsigned char *data;
int len;
int err;
bool ret = true;
bool can_disconnect = instance->irq != NO_IRQ &&
cmd->cmnd[0] != REQUEST_SENSE &&
(disconnect_mask & BIT(scmd_id(cmd)));
NCR5380_dprint(NDEBUG_ARBITRATION, instance);
dsprintk(NDEBUG_ARBITRATION, instance, "starting arbitration, id = %d\n",
instance->this_id);
/*
* Arbitration and selection phases are slow and involve dropping the
* lock, so we have to watch out for EH. An exception handler may
* change 'selecting' to NULL. This function will then return false
* so that the caller will forget about 'cmd'. (During information
* transfer phases, EH may change 'connected' to NULL.)
*/
hostdata->selecting = cmd;
/*
* Set the phase bits to 0, otherwise the NCR5380 won't drive the
* data bus during SELECTION.
*/
NCR5380_write(TARGET_COMMAND_REG, 0);
/*
* Start arbitration.
*/
NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
NCR5380_write(MODE_REG, MR_ARBITRATE);
/* The chip now waits for BUS FREE phase. Then after the 800 ns
* Bus Free Delay, arbitration will begin.
*/
ncr5380: Change instance->host_lock to hostdata->lock NCR5380.c presently uses the instance->host_lock spin lock. Convert this to a new spin lock that protects the NCR5380_hostdata struct. atari_NCR5380.c previously used local_irq_save/restore() rather than a spin lock. Convert this to hostdata->lock in irq mode. For SMP platforms, the interrupt handler now also acquires the spin lock. This brings all locking in the two core drivers into agreement. Adding this locking also means that a bunch of volatile qualifiers can be removed from the members of the NCR5380_hostdata struct. This is done in a subsequent patch. Proper locking will allow the abort handler to locate a command being aborted. This is presently impossible if the abort handler is invoked when the command has been moved from a queue to a pointer on the stack. (If eh_abort_handler can't determine whether a command has been completed or is still being processed then it can't decide whether to return success or failure.) The hostdata spin lock is now held when calling NCR5380_select() and NCR5380_information_transfer(). Where possible, the lock is dropped for polling and PIO transfers. Clean up the now-redundant SELECT_ENABLE_REG writes, that used to provide limited mutual exclusion between information_transfer() and reselect(). Accessing hostdata->connected without data races means taking the lock; cleanup these accesses. The new spin lock falls away for m68k and other UP builds, so this should have little impact there. In the SMP case the new lock should be uncontested even when the SCSI bus is contested. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:51 +08:00
spin_unlock_irq(&hostdata->lock);
err = NCR5380_poll_politely2(hostdata, MODE_REG, MR_ARBITRATE, 0,
INITIATOR_COMMAND_REG, ICR_ARBITRATION_PROGRESS,
ICR_ARBITRATION_PROGRESS, HZ);
ncr5380: Change instance->host_lock to hostdata->lock NCR5380.c presently uses the instance->host_lock spin lock. Convert this to a new spin lock that protects the NCR5380_hostdata struct. atari_NCR5380.c previously used local_irq_save/restore() rather than a spin lock. Convert this to hostdata->lock in irq mode. For SMP platforms, the interrupt handler now also acquires the spin lock. This brings all locking in the two core drivers into agreement. Adding this locking also means that a bunch of volatile qualifiers can be removed from the members of the NCR5380_hostdata struct. This is done in a subsequent patch. Proper locking will allow the abort handler to locate a command being aborted. This is presently impossible if the abort handler is invoked when the command has been moved from a queue to a pointer on the stack. (If eh_abort_handler can't determine whether a command has been completed or is still being processed then it can't decide whether to return success or failure.) The hostdata spin lock is now held when calling NCR5380_select() and NCR5380_information_transfer(). Where possible, the lock is dropped for polling and PIO transfers. Clean up the now-redundant SELECT_ENABLE_REG writes, that used to provide limited mutual exclusion between information_transfer() and reselect(). Accessing hostdata->connected without data races means taking the lock; cleanup these accesses. The new spin lock falls away for m68k and other UP builds, so this should have little impact there. In the SMP case the new lock should be uncontested even when the SCSI bus is contested. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:51 +08:00
spin_lock_irq(&hostdata->lock);
if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE)) {
/* Reselection interrupt */
goto out;
}
if (!hostdata->selecting) {
/* Command was aborted */
NCR5380_write(MODE_REG, MR_BASE);
return false;
}
if (err < 0) {
NCR5380_write(MODE_REG, MR_BASE);
shost_printk(KERN_ERR, instance,
"select: arbitration timeout\n");
goto out;
}
ncr5380: Change instance->host_lock to hostdata->lock NCR5380.c presently uses the instance->host_lock spin lock. Convert this to a new spin lock that protects the NCR5380_hostdata struct. atari_NCR5380.c previously used local_irq_save/restore() rather than a spin lock. Convert this to hostdata->lock in irq mode. For SMP platforms, the interrupt handler now also acquires the spin lock. This brings all locking in the two core drivers into agreement. Adding this locking also means that a bunch of volatile qualifiers can be removed from the members of the NCR5380_hostdata struct. This is done in a subsequent patch. Proper locking will allow the abort handler to locate a command being aborted. This is presently impossible if the abort handler is invoked when the command has been moved from a queue to a pointer on the stack. (If eh_abort_handler can't determine whether a command has been completed or is still being processed then it can't decide whether to return success or failure.) The hostdata spin lock is now held when calling NCR5380_select() and NCR5380_information_transfer(). Where possible, the lock is dropped for polling and PIO transfers. Clean up the now-redundant SELECT_ENABLE_REG writes, that used to provide limited mutual exclusion between information_transfer() and reselect(). Accessing hostdata->connected without data races means taking the lock; cleanup these accesses. The new spin lock falls away for m68k and other UP builds, so this should have little impact there. In the SMP case the new lock should be uncontested even when the SCSI bus is contested. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:51 +08:00
spin_unlock_irq(&hostdata->lock);
/* The SCSI-2 arbitration delay is 2.4 us */
udelay(3);
/* Check for lost arbitration */
if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
(NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_higher_mask) ||
(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST)) {
NCR5380_write(MODE_REG, MR_BASE);
dsprintk(NDEBUG_ARBITRATION, instance, "lost arbitration, deasserting MR_ARBITRATE\n");
ncr5380: Change instance->host_lock to hostdata->lock NCR5380.c presently uses the instance->host_lock spin lock. Convert this to a new spin lock that protects the NCR5380_hostdata struct. atari_NCR5380.c previously used local_irq_save/restore() rather than a spin lock. Convert this to hostdata->lock in irq mode. For SMP platforms, the interrupt handler now also acquires the spin lock. This brings all locking in the two core drivers into agreement. Adding this locking also means that a bunch of volatile qualifiers can be removed from the members of the NCR5380_hostdata struct. This is done in a subsequent patch. Proper locking will allow the abort handler to locate a command being aborted. This is presently impossible if the abort handler is invoked when the command has been moved from a queue to a pointer on the stack. (If eh_abort_handler can't determine whether a command has been completed or is still being processed then it can't decide whether to return success or failure.) The hostdata spin lock is now held when calling NCR5380_select() and NCR5380_information_transfer(). Where possible, the lock is dropped for polling and PIO transfers. Clean up the now-redundant SELECT_ENABLE_REG writes, that used to provide limited mutual exclusion between information_transfer() and reselect(). Accessing hostdata->connected without data races means taking the lock; cleanup these accesses. The new spin lock falls away for m68k and other UP builds, so this should have little impact there. In the SMP case the new lock should be uncontested even when the SCSI bus is contested. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:51 +08:00
spin_lock_irq(&hostdata->lock);
goto out;
}
/* After/during arbitration, BSY should be asserted.
* IBM DPES-31080 Version S31Q works now
* Tnx to Thomas_Roesch@m2.maus.de for finding this! (Roman)
*/
NCR5380_write(INITIATOR_COMMAND_REG,
ICR_BASE | ICR_ASSERT_SEL | ICR_ASSERT_BSY);
/*
* Again, bus clear + bus settle time is 1.2us, however, this is
* a minimum so we'll udelay ceil(1.2)
*/
if (hostdata->flags & FLAG_TOSHIBA_DELAY)
udelay(15);
else
udelay(2);
ncr5380: Change instance->host_lock to hostdata->lock NCR5380.c presently uses the instance->host_lock spin lock. Convert this to a new spin lock that protects the NCR5380_hostdata struct. atari_NCR5380.c previously used local_irq_save/restore() rather than a spin lock. Convert this to hostdata->lock in irq mode. For SMP platforms, the interrupt handler now also acquires the spin lock. This brings all locking in the two core drivers into agreement. Adding this locking also means that a bunch of volatile qualifiers can be removed from the members of the NCR5380_hostdata struct. This is done in a subsequent patch. Proper locking will allow the abort handler to locate a command being aborted. This is presently impossible if the abort handler is invoked when the command has been moved from a queue to a pointer on the stack. (If eh_abort_handler can't determine whether a command has been completed or is still being processed then it can't decide whether to return success or failure.) The hostdata spin lock is now held when calling NCR5380_select() and NCR5380_information_transfer(). Where possible, the lock is dropped for polling and PIO transfers. Clean up the now-redundant SELECT_ENABLE_REG writes, that used to provide limited mutual exclusion between information_transfer() and reselect(). Accessing hostdata->connected without data races means taking the lock; cleanup these accesses. The new spin lock falls away for m68k and other UP builds, so this should have little impact there. In the SMP case the new lock should be uncontested even when the SCSI bus is contested. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:51 +08:00
spin_lock_irq(&hostdata->lock);
/* NCR5380_reselect() clears MODE_REG after a reselection interrupt */
if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE))
goto out;
if (!hostdata->selecting) {
NCR5380_write(MODE_REG, MR_BASE);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
return false;
}
dsprintk(NDEBUG_ARBITRATION, instance, "won arbitration\n");
/*
* Now that we have won arbitration, start Selection process, asserting
* the host and target ID's on the SCSI bus.
*/
NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask | (1 << scmd_id(cmd)));
/*
* Raise ATN while SEL is true before BSY goes false from arbitration,
* since this is the only way to guarantee that we'll get a MESSAGE OUT
* phase immediately after selection.
*/
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY |
ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL);
NCR5380_write(MODE_REG, MR_BASE);
/*
* Reselect interrupts must be turned off prior to the dropping of BSY,
* otherwise we will trigger an interrupt.
*/
NCR5380_write(SELECT_ENABLE_REG, 0);
ncr5380: Change instance->host_lock to hostdata->lock NCR5380.c presently uses the instance->host_lock spin lock. Convert this to a new spin lock that protects the NCR5380_hostdata struct. atari_NCR5380.c previously used local_irq_save/restore() rather than a spin lock. Convert this to hostdata->lock in irq mode. For SMP platforms, the interrupt handler now also acquires the spin lock. This brings all locking in the two core drivers into agreement. Adding this locking also means that a bunch of volatile qualifiers can be removed from the members of the NCR5380_hostdata struct. This is done in a subsequent patch. Proper locking will allow the abort handler to locate a command being aborted. This is presently impossible if the abort handler is invoked when the command has been moved from a queue to a pointer on the stack. (If eh_abort_handler can't determine whether a command has been completed or is still being processed then it can't decide whether to return success or failure.) The hostdata spin lock is now held when calling NCR5380_select() and NCR5380_information_transfer(). Where possible, the lock is dropped for polling and PIO transfers. Clean up the now-redundant SELECT_ENABLE_REG writes, that used to provide limited mutual exclusion between information_transfer() and reselect(). Accessing hostdata->connected without data races means taking the lock; cleanup these accesses. The new spin lock falls away for m68k and other UP builds, so this should have little impact there. In the SMP case the new lock should be uncontested even when the SCSI bus is contested. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:51 +08:00
spin_unlock_irq(&hostdata->lock);
/*
* The initiator shall then wait at least two deskew delays and release
* the BSY signal.
*/
udelay(1); /* wingel -- wait two bus deskew delay >2*45ns */
/* Reset BSY */
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA |
ICR_ASSERT_ATN | ICR_ASSERT_SEL);
/*
* Something weird happens when we cease to drive BSY - looks
* like the board/chip is letting us do another read before the
* appropriate propagation delay has expired, and we're confusing
* a BSY signal from ourselves as the target's response to SELECTION.
*
* A small delay (the 'C++' frontend breaks the pipeline with an
* unnecessary jump, making it work on my 386-33/Trantor T128, the
* tighter 'C' code breaks and requires this) solves the problem -
* the 1 us delay is arbitrary, and only used because this delay will
* be the same on other platforms and since it works here, it should
* work there.
*
* wingel suggests that this could be due to failing to wait
* one deskew delay.
*/
udelay(1);
dsprintk(NDEBUG_SELECTION, instance, "selecting target %d\n", scmd_id(cmd));
/*
* The SCSI specification calls for a 250 ms timeout for the actual
* selection.
*/
err = NCR5380_poll_politely(hostdata, STATUS_REG, SR_BSY, SR_BSY,
msecs_to_jiffies(250));
if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
ncr5380: Change instance->host_lock to hostdata->lock NCR5380.c presently uses the instance->host_lock spin lock. Convert this to a new spin lock that protects the NCR5380_hostdata struct. atari_NCR5380.c previously used local_irq_save/restore() rather than a spin lock. Convert this to hostdata->lock in irq mode. For SMP platforms, the interrupt handler now also acquires the spin lock. This brings all locking in the two core drivers into agreement. Adding this locking also means that a bunch of volatile qualifiers can be removed from the members of the NCR5380_hostdata struct. This is done in a subsequent patch. Proper locking will allow the abort handler to locate a command being aborted. This is presently impossible if the abort handler is invoked when the command has been moved from a queue to a pointer on the stack. (If eh_abort_handler can't determine whether a command has been completed or is still being processed then it can't decide whether to return success or failure.) The hostdata spin lock is now held when calling NCR5380_select() and NCR5380_information_transfer(). Where possible, the lock is dropped for polling and PIO transfers. Clean up the now-redundant SELECT_ENABLE_REG writes, that used to provide limited mutual exclusion between information_transfer() and reselect(). Accessing hostdata->connected without data races means taking the lock; cleanup these accesses. The new spin lock falls away for m68k and other UP builds, so this should have little impact there. In the SMP case the new lock should be uncontested even when the SCSI bus is contested. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:51 +08:00
spin_lock_irq(&hostdata->lock);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
NCR5380_reselect(instance);
shost_printk(KERN_ERR, instance, "reselection after won arbitration?\n");
goto out;
}
if (err < 0) {
ncr5380: Change instance->host_lock to hostdata->lock NCR5380.c presently uses the instance->host_lock spin lock. Convert this to a new spin lock that protects the NCR5380_hostdata struct. atari_NCR5380.c previously used local_irq_save/restore() rather than a spin lock. Convert this to hostdata->lock in irq mode. For SMP platforms, the interrupt handler now also acquires the spin lock. This brings all locking in the two core drivers into agreement. Adding this locking also means that a bunch of volatile qualifiers can be removed from the members of the NCR5380_hostdata struct. This is done in a subsequent patch. Proper locking will allow the abort handler to locate a command being aborted. This is presently impossible if the abort handler is invoked when the command has been moved from a queue to a pointer on the stack. (If eh_abort_handler can't determine whether a command has been completed or is still being processed then it can't decide whether to return success or failure.) The hostdata spin lock is now held when calling NCR5380_select() and NCR5380_information_transfer(). Where possible, the lock is dropped for polling and PIO transfers. Clean up the now-redundant SELECT_ENABLE_REG writes, that used to provide limited mutual exclusion between information_transfer() and reselect(). Accessing hostdata->connected without data races means taking the lock; cleanup these accesses. The new spin lock falls away for m68k and other UP builds, so this should have little impact there. In the SMP case the new lock should be uncontested even when the SCSI bus is contested. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:51 +08:00
spin_lock_irq(&hostdata->lock);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
/* Can't touch cmd if it has been reclaimed by the scsi ML */
if (!hostdata->selecting)
return false;
cmd->result = DID_BAD_TARGET << 16;
complete_cmd(instance, cmd);
dsprintk(NDEBUG_SELECTION, instance,
"target did not respond within 250ms\n");
ret = false;
goto out;
}
/*
* No less than two deskew delays after the initiator detects the
* BSY signal is true, it shall release the SEL signal and may
* change the DATA BUS. -wingel
*/
udelay(1);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
/*
* Since we followed the SCSI spec, and raised ATN while SEL
* was true but before BSY was false during selection, the information
* transfer phase should be a MESSAGE OUT phase so that we can send the
* IDENTIFY message.
*/
/* Wait for start of REQ/ACK handshake */
err = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ);
ncr5380: Change instance->host_lock to hostdata->lock NCR5380.c presently uses the instance->host_lock spin lock. Convert this to a new spin lock that protects the NCR5380_hostdata struct. atari_NCR5380.c previously used local_irq_save/restore() rather than a spin lock. Convert this to hostdata->lock in irq mode. For SMP platforms, the interrupt handler now also acquires the spin lock. This brings all locking in the two core drivers into agreement. Adding this locking also means that a bunch of volatile qualifiers can be removed from the members of the NCR5380_hostdata struct. This is done in a subsequent patch. Proper locking will allow the abort handler to locate a command being aborted. This is presently impossible if the abort handler is invoked when the command has been moved from a queue to a pointer on the stack. (If eh_abort_handler can't determine whether a command has been completed or is still being processed then it can't decide whether to return success or failure.) The hostdata spin lock is now held when calling NCR5380_select() and NCR5380_information_transfer(). Where possible, the lock is dropped for polling and PIO transfers. Clean up the now-redundant SELECT_ENABLE_REG writes, that used to provide limited mutual exclusion between information_transfer() and reselect(). Accessing hostdata->connected without data races means taking the lock; cleanup these accesses. The new spin lock falls away for m68k and other UP builds, so this should have little impact there. In the SMP case the new lock should be uncontested even when the SCSI bus is contested. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:51 +08:00
spin_lock_irq(&hostdata->lock);
if (err < 0) {
shost_printk(KERN_ERR, instance, "select: REQ timeout\n");
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
goto out;
}
if (!hostdata->selecting) {
do_abort(instance);
return false;
}
dsprintk(NDEBUG_SELECTION, instance, "target %d selected, going into MESSAGE OUT phase.\n",
scmd_id(cmd));
tmp[0] = IDENTIFY(can_disconnect, cmd->device->lun);
len = 1;
data = tmp;
phase = PHASE_MSGOUT;
NCR5380_transfer_pio(instance, &phase, &len, &data);
if (len) {
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
cmd->result = DID_ERROR << 16;
complete_cmd(instance, cmd);
dsprintk(NDEBUG_SELECTION, instance, "IDENTIFY message transfer failed\n");
ret = false;
goto out;
}
dsprintk(NDEBUG_SELECTION, instance, "nexus established.\n");
ncr5380: Change instance->host_lock to hostdata->lock NCR5380.c presently uses the instance->host_lock spin lock. Convert this to a new spin lock that protects the NCR5380_hostdata struct. atari_NCR5380.c previously used local_irq_save/restore() rather than a spin lock. Convert this to hostdata->lock in irq mode. For SMP platforms, the interrupt handler now also acquires the spin lock. This brings all locking in the two core drivers into agreement. Adding this locking also means that a bunch of volatile qualifiers can be removed from the members of the NCR5380_hostdata struct. This is done in a subsequent patch. Proper locking will allow the abort handler to locate a command being aborted. This is presently impossible if the abort handler is invoked when the command has been moved from a queue to a pointer on the stack. (If eh_abort_handler can't determine whether a command has been completed or is still being processed then it can't decide whether to return success or failure.) The hostdata spin lock is now held when calling NCR5380_select() and NCR5380_information_transfer(). Where possible, the lock is dropped for polling and PIO transfers. Clean up the now-redundant SELECT_ENABLE_REG writes, that used to provide limited mutual exclusion between information_transfer() and reselect(). Accessing hostdata->connected without data races means taking the lock; cleanup these accesses. The new spin lock falls away for m68k and other UP builds, so this should have little impact there. In the SMP case the new lock should be uncontested even when the SCSI bus is contested. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:51 +08:00
hostdata->connected = cmd;
hostdata->busy[cmd->device->id] |= 1 << cmd->device->lun;
#ifdef SUN3_SCSI_VME
dregs->csr |= CSR_INTR;
#endif
initialize_SCp(cmd);
ret = false;
out:
if (!hostdata->selecting)
return false;
hostdata->selecting = NULL;
return ret;
}
/*
* Function : int NCR5380_transfer_pio (struct Scsi_Host *instance,
* unsigned char *phase, int *count, unsigned char **data)
*
* Purpose : transfers data in given phase using polled I/O
*
* Inputs : instance - instance of driver, *phase - pointer to
* what phase is expected, *count - pointer to number of
* bytes to transfer, **data - pointer to data pointer.
*
* Returns : -1 when different phase is entered without transferring
* maximum number of bytes, 0 if all bytes are transferred or exit
* is in same phase.
*
* Also, *phase, *count, *data are modified in place.
*
* XXX Note : handling for bus free may be useful.
*/
/*
* Note : this code is not as quick as it could be, however it
* IS 100% reliable, and for the actual data transfer where speed
* counts, we will always do a pseudo DMA or DMA transfer.
*/
static int NCR5380_transfer_pio(struct Scsi_Host *instance,
unsigned char *phase, int *count,
unsigned char **data)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
unsigned char p = *phase, tmp;
int c = *count;
unsigned char *d = *data;
/*
* The NCR5380 chip will only drive the SCSI bus when the
* phase specified in the appropriate bits of the TARGET COMMAND
* REGISTER match the STATUS REGISTER
*/
NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
do {
/*
* Wait for assertion of REQ, after which the phase bits will be
* valid
*/
if (NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ) < 0)
break;
dsprintk(NDEBUG_HANDSHAKE, instance, "REQ asserted\n");
/* Check for phase mismatch */
ncr5380: Rework disconnect versus poll logic The atari_NCR5380.c and NCR5380.c core drivers differ in their handling of target disconnection. This is partly because atari_NCR5380.c had all of the polling and sleeping removed to become entirely interrupt-driven, and it is partly because of damage done to NCR5380.c after atari_NCR5380.c was forked. See commit 37cd23b44929 ("Linux 2.1.105") in history/history.git. The polling changes that were made in v2.1.105 are questionable at best: if REQ is not already asserted when NCR5380_transfer_pio() is invoked, and if the expected phase is DATA IN or DATA OUT, the function will schedule main() to execute after USLEEP_SLEEP jiffies and then return. The problems here are the expected REQ timing and the sleep interval*. Avoid this issue by using NCR5380_poll_politely() instead of scheduling main(). The atari_NCR5380.c core driver requires the use of the chip interrupt and always permits target disconnection. It sets the cmd->device->disconnect flag when a device disconnects, but never tests this flag. The NCR5380.c core driver permits disconnection only when instance->irq != NO_IRQ. It sets the cmd->device->disconnect flag when a device disconnects and it tests this flag in a couple of places: 1. During NCR5380_information_transfer(), following COMMAND OUT phase, if !cmd->device->disconnect, the initiator will take a guess as to whether or not the target will then choose to go to MESSAGE IN phase and disconnect. If the driver guesses "yes", it will schedule main() to execute after USLEEP_SLEEP jiffies and then return there. Unfortunately the driver may guess "yes" even after it has denied the target the disconnection privilege. When the target does not disconnect, the sleep can be beneficial, assuming the sleep interval is appropriate (mostly it is not*). And even if the driver guesses "yes" correctly, and the target would then disconnect, the driver still has to go through the MESSAGE IN phase in order to get to BUS FREE phase. The main loop can do nothing useful until BUS FREE, and sleeping just delays the phase transition. 2. If !cmd->device->disconnect and REQ is not already asserted when NCR5380_information_transfer() is invoked, the function polls for REQ for USLEEP_POLL jiffies. If REQ is not asserted, it then schedules main() to execute after USLEEP_SLEEP jiffies and returns. The idea is apparently to yeild the CPU while waiting for REQ. This is conditional upon !cmd->device->disconnect, but there seems to be no rhyme or reason for that. For example, the flag may be unset because disconnection privilege was denied because the driver has no IRQ. Or the flag may be unset because the device has never needed to disconnect before. Or if the flag is set, disconnection may have no relevance to the present bus phase. Another deficiency of the existing algorithm is as follows. When the driver has no IRQ, it prevents disconnection, and generally polls and sleeps more than it would normally. Now, if the driver is going to poll anyway, why not allow the target to disconnect? That way the driver can do something useful with the bus instead of polling unproductively! Avoid this pointless latency, complexity and guesswork by using NCR5380_poll_politely() instead of scheduling main(). * For g_NCR5380, the time intervals for USLEEP_SLEEP and USLEEP_POLL are 200 ms and 10 ms, respectively. They are 20 ms and 200 ms respectively for the other NCR5380 drivers. There doesn't seem to be any reason for this discrepancy. The timing seems to have no relation to the type of adapter. Bizarrely, the timing in g_NCR5380 seems to relate only to one particular type of target device. This patch attempts to solve the problem for all NCR5380 drivers and all target devices. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:26 +08:00
if ((NCR5380_read(STATUS_REG) & PHASE_MASK) != p) {
dsprintk(NDEBUG_PIO, instance, "phase mismatch\n");
NCR5380_dprint_phase(NDEBUG_PIO, instance);
break;
}
/* Do actual transfer from SCSI bus to / from memory */
if (!(p & SR_IO))
NCR5380_write(OUTPUT_DATA_REG, *d);
else
*d = NCR5380_read(CURRENT_SCSI_DATA_REG);
++d;
/*
* The SCSI standard suggests that in MSGOUT phase, the initiator
* should drop ATN on the last byte of the message phase
* after REQ has been asserted for the handshake but before
* the initiator raises ACK.
*/
if (!(p & SR_IO)) {
if (!((p & SR_MSG) && c > 1)) {
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
NCR5380_dprint(NDEBUG_PIO, instance);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
ICR_ASSERT_DATA | ICR_ASSERT_ACK);
} else {
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
ICR_ASSERT_DATA | ICR_ASSERT_ATN);
NCR5380_dprint(NDEBUG_PIO, instance);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
}
} else {
NCR5380_dprint(NDEBUG_PIO, instance);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
}
if (NCR5380_poll_politely(hostdata,
STATUS_REG, SR_REQ, 0, 5 * HZ) < 0)
break;
dsprintk(NDEBUG_HANDSHAKE, instance, "REQ negated, handshake complete\n");
/*
* We have several special cases to consider during REQ/ACK handshaking :
* 1. We were in MSGOUT phase, and we are on the last byte of the
* message. ATN must be dropped as ACK is dropped.
*
* 2. We are in a MSGIN phase, and we are on the last byte of the
* message. We must exit with ACK asserted, so that the calling
* code may raise ATN before dropping ACK to reject the message.
*
* 3. ACK and ATN are clear and the target may proceed as normal.
*/
if (!(p == PHASE_MSGIN && c == 1)) {
if (p == PHASE_MSGOUT && c > 1)
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
else
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
}
} while (--c);
dsprintk(NDEBUG_PIO, instance, "residual %d\n", c);
*count = c;
*data = d;
tmp = NCR5380_read(STATUS_REG);
/* The phase read from the bus is valid if either REQ is (already)
* asserted or if ACK hasn't been released yet. The latter applies if
* we're in MSG IN, DATA IN or STATUS and all bytes have been received.
*/
if ((tmp & SR_REQ) || ((tmp & SR_IO) && c == 0))
*phase = tmp & PHASE_MASK;
else
*phase = PHASE_UNKNOWN;
if (!c || (*phase == p))
return 0;
else
return -1;
}
/**
* do_reset - issue a reset command
* @instance: adapter to reset
*
* Issue a reset sequence to the NCR5380 and try and get the bus
* back into sane shape.
*
* This clears the reset interrupt flag because there may be no handler for
* it. When the driver is initialized, the NCR5380_intr() handler has not yet
* been installed. And when in EH we may have released the ST DMA interrupt.
*/
static void do_reset(struct Scsi_Host *instance)
{
struct NCR5380_hostdata __maybe_unused *hostdata = shost_priv(instance);
unsigned long flags;
local_irq_save(flags);
NCR5380_write(TARGET_COMMAND_REG,
PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG) & PHASE_MASK));
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
udelay(50);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
(void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
local_irq_restore(flags);
}
/**
* do_abort - abort the currently established nexus by going to
* MESSAGE OUT phase and sending an ABORT message.
* @instance: relevant scsi host instance
*
* Returns 0 on success, negative error code on failure.
*/
static int do_abort(struct Scsi_Host *instance)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
unsigned char *msgptr, phase, tmp;
int len;
int rc;
/* Request message out phase */
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
/*
* Wait for the target to indicate a valid phase by asserting
* REQ. Once this happens, we'll have either a MSGOUT phase
* and can immediately send the ABORT message, or we'll have some
* other phase and will have to source/sink data.
*
* We really don't care what value was on the bus or what value
* the target sees, so we just handshake.
*/
rc = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, 10 * HZ);
if (rc < 0)
goto out;
tmp = NCR5380_read(STATUS_REG) & PHASE_MASK;
NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
if (tmp != PHASE_MSGOUT) {
NCR5380_write(INITIATOR_COMMAND_REG,
ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
rc = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, 0, 3 * HZ);
if (rc < 0)
goto out;
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
}
tmp = ABORT;
msgptr = &tmp;
len = 1;
phase = PHASE_MSGOUT;
NCR5380_transfer_pio(instance, &phase, &len, &msgptr);
if (len)
rc = -ENXIO;
/*
* If we got here, and the command completed successfully,
* we're about to go into bus free state.
*/
out:
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
return rc;
}
/*
* Function : int NCR5380_transfer_dma (struct Scsi_Host *instance,
* unsigned char *phase, int *count, unsigned char **data)
*
* Purpose : transfers data in given phase using either real
* or pseudo DMA.
*
* Inputs : instance - instance of driver, *phase - pointer to
* what phase is expected, *count - pointer to number of
* bytes to transfer, **data - pointer to data pointer.
*
* Returns : -1 when different phase is entered without transferring
* maximum number of bytes, 0 if all bytes or transferred or exit
* is in same phase.
*
* Also, *phase, *count, *data are modified in place.
*/
static int NCR5380_transfer_dma(struct Scsi_Host *instance,
unsigned char *phase, int *count,
unsigned char **data)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
int c = *count;
unsigned char p = *phase;
unsigned char *d = *data;
unsigned char tmp;
int result = 0;
if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
*phase = tmp;
return -1;
}
hostdata->connected->SCp.phase = p;
if (p & SR_IO) {
if (hostdata->read_overruns)
c -= hostdata->read_overruns;
else if (hostdata->flags & FLAG_DMA_FIXUP)
--c;
}
dsprintk(NDEBUG_DMA, instance, "initializing DMA %s: length %d, address %p\n",
(p & SR_IO) ? "receive" : "send", c, d);
#ifdef CONFIG_SUN3
/* send start chain */
sun3scsi_dma_start(c, *data);
#endif
NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_MONITOR_BSY |
MR_ENABLE_EOP_INTR);
if (!(hostdata->flags & FLAG_LATE_DMA_SETUP)) {
/* On the Medusa, it is a must to initialize the DMA before
* starting the NCR. This is also the cleaner way for the TT.
*/
if (p & SR_IO)
result = NCR5380_dma_recv_setup(hostdata, d, c);
else
result = NCR5380_dma_send_setup(hostdata, d, c);
}
/*
* On the PAS16 at least I/O recovery delays are not needed here.
* Everyone else seems to want them.
*/
if (p & SR_IO) {
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
NCR5380_io_delay(1);
NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
} else {
NCR5380_io_delay(1);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
NCR5380_io_delay(1);
NCR5380_write(START_DMA_SEND_REG, 0);
NCR5380_io_delay(1);
}
#ifdef CONFIG_SUN3
#ifdef SUN3_SCSI_VME
dregs->csr |= CSR_DMA_ENABLE;
#endif
sun3_dma_active = 1;
#endif
if (hostdata->flags & FLAG_LATE_DMA_SETUP) {
/* On the Falcon, the DMA setup must be done after the last
* NCR access, else the DMA setup gets trashed!
*/
if (p & SR_IO)
result = NCR5380_dma_recv_setup(hostdata, d, c);
else
result = NCR5380_dma_send_setup(hostdata, d, c);
}
/* On failure, NCR5380_dma_xxxx_setup() returns a negative int. */
if (result < 0)
return result;
/* For real DMA, result is the byte count. DMA interrupt is expected. */
if (result > 0) {
hostdata->dma_len = result;
return 0;
}
/* The result is zero iff pseudo DMA send/receive was completed. */
hostdata->dma_len = c;
/*
* A note regarding the DMA errata workarounds for early NMOS silicon.
*
* For DMA sends, we want to wait until the last byte has been
* transferred out over the bus before we turn off DMA mode. Alas, there
* seems to be no terribly good way of doing this on a 5380 under all
* conditions. For non-scatter-gather operations, we can wait until REQ
* and ACK both go false, or until a phase mismatch occurs. Gather-sends
* are nastier, since the device will be expecting more data than we
* are prepared to send it, and REQ will remain asserted. On a 53C8[01] we
* could test Last Byte Sent to assure transfer (I imagine this is precisely
* why this signal was added to the newer chips) but on the older 538[01]
* this signal does not exist. The workaround for this lack is a watchdog;
* we bail out of the wait-loop after a modest amount of wait-time if
* the usual exit conditions are not met. Not a terribly clean or
* correct solution :-%
*
* DMA receive is equally tricky due to a nasty characteristic of the NCR5380.
* If the chip is in DMA receive mode, it will respond to a target's
* REQ by latching the SCSI data into the INPUT DATA register and asserting
* ACK, even if it has _already_ been notified by the DMA controller that
* the current DMA transfer has completed! If the NCR5380 is then taken
* out of DMA mode, this already-acknowledged byte is lost. This is
* not a problem for "one DMA transfer per READ command", because
* the situation will never arise... either all of the data is DMA'ed
* properly, or the target switches to MESSAGE IN phase to signal a
* disconnection (either operation bringing the DMA to a clean halt).
* However, in order to handle scatter-receive, we must work around the
* problem. The chosen fix is to DMA fewer bytes, then check for the
* condition before taking the NCR5380 out of DMA mode. One or two extra
* bytes are transferred via PIO as necessary to fill out the original
* request.
*/
if (hostdata->flags & FLAG_DMA_FIXUP) {
if (p & SR_IO) {
/*
* The workaround was to transfer fewer bytes than we
* intended to with the pseudo-DMA read function, wait for
* the chip to latch the last byte, read it, and then disable
* pseudo-DMA mode.
*
* After REQ is asserted, the NCR5380 asserts DRQ and ACK.
* REQ is deasserted when ACK is asserted, and not reasserted
* until ACK goes false. Since the NCR5380 won't lower ACK
* until DACK is asserted, which won't happen unless we twiddle
* the DMA port or we take the NCR5380 out of DMA mode, we
* can guarantee that we won't handshake another extra
* byte.
*/
if (NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG,
BASR_DRQ, BASR_DRQ, HZ) < 0) {
result = -1;
shost_printk(KERN_ERR, instance, "PDMA read: DRQ timeout\n");
}
if (NCR5380_poll_politely(hostdata, STATUS_REG,
SR_REQ, 0, HZ) < 0) {
result = -1;
shost_printk(KERN_ERR, instance, "PDMA read: !REQ timeout\n");
}
d[*count - 1] = NCR5380_read(INPUT_DATA_REG);
} else {
/*
* Wait for the last byte to be sent. If REQ is being asserted for
* the byte we're interested, we'll ACK it and it will go false.
*/
if (NCR5380_poll_politely2(hostdata,
BUS_AND_STATUS_REG, BASR_DRQ, BASR_DRQ,
BUS_AND_STATUS_REG, BASR_PHASE_MATCH, 0, HZ) < 0) {
result = -1;
shost_printk(KERN_ERR, instance, "PDMA write: DRQ and phase timeout\n");
}
}
}
NCR5380_dma_complete(instance);
return result;
}
/*
* Function : NCR5380_information_transfer (struct Scsi_Host *instance)
*
* Purpose : run through the various SCSI phases and do as the target
* directs us to. Operates on the currently connected command,
* instance->connected.
*
* Inputs : instance, instance for which we are doing commands
*
* Side effects : SCSI things happen, the disconnected queue will be
* modified if a command disconnects, *instance->connected will
* change.
*
* XXX Note : we need to watch for bus free or a reset condition here
* to recover from an unexpected bus free condition.
*/
static void NCR5380_information_transfer(struct Scsi_Host *instance)
__releases(&hostdata->lock) __acquires(&hostdata->lock)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
unsigned char msgout = NOP;
int sink = 0;
int len;
int transfersize;
unsigned char *data;
unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
ncr5380: Change instance->host_lock to hostdata->lock NCR5380.c presently uses the instance->host_lock spin lock. Convert this to a new spin lock that protects the NCR5380_hostdata struct. atari_NCR5380.c previously used local_irq_save/restore() rather than a spin lock. Convert this to hostdata->lock in irq mode. For SMP platforms, the interrupt handler now also acquires the spin lock. This brings all locking in the two core drivers into agreement. Adding this locking also means that a bunch of volatile qualifiers can be removed from the members of the NCR5380_hostdata struct. This is done in a subsequent patch. Proper locking will allow the abort handler to locate a command being aborted. This is presently impossible if the abort handler is invoked when the command has been moved from a queue to a pointer on the stack. (If eh_abort_handler can't determine whether a command has been completed or is still being processed then it can't decide whether to return success or failure.) The hostdata spin lock is now held when calling NCR5380_select() and NCR5380_information_transfer(). Where possible, the lock is dropped for polling and PIO transfers. Clean up the now-redundant SELECT_ENABLE_REG writes, that used to provide limited mutual exclusion between information_transfer() and reselect(). Accessing hostdata->connected without data races means taking the lock; cleanup these accesses. The new spin lock falls away for m68k and other UP builds, so this should have little impact there. In the SMP case the new lock should be uncontested even when the SCSI bus is contested. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:51 +08:00
struct scsi_cmnd *cmd;
#ifdef SUN3_SCSI_VME
dregs->csr |= CSR_INTR;
#endif
ncr5380: Change instance->host_lock to hostdata->lock NCR5380.c presently uses the instance->host_lock spin lock. Convert this to a new spin lock that protects the NCR5380_hostdata struct. atari_NCR5380.c previously used local_irq_save/restore() rather than a spin lock. Convert this to hostdata->lock in irq mode. For SMP platforms, the interrupt handler now also acquires the spin lock. This brings all locking in the two core drivers into agreement. Adding this locking also means that a bunch of volatile qualifiers can be removed from the members of the NCR5380_hostdata struct. This is done in a subsequent patch. Proper locking will allow the abort handler to locate a command being aborted. This is presently impossible if the abort handler is invoked when the command has been moved from a queue to a pointer on the stack. (If eh_abort_handler can't determine whether a command has been completed or is still being processed then it can't decide whether to return success or failure.) The hostdata spin lock is now held when calling NCR5380_select() and NCR5380_information_transfer(). Where possible, the lock is dropped for polling and PIO transfers. Clean up the now-redundant SELECT_ENABLE_REG writes, that used to provide limited mutual exclusion between information_transfer() and reselect(). Accessing hostdata->connected without data races means taking the lock; cleanup these accesses. The new spin lock falls away for m68k and other UP builds, so this should have little impact there. In the SMP case the new lock should be uncontested even when the SCSI bus is contested. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:51 +08:00
while ((cmd = hostdata->connected)) {
struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
tmp = NCR5380_read(STATUS_REG);
/* We only have a valid SCSI phase when REQ is asserted */
if (tmp & SR_REQ) {
phase = (tmp & PHASE_MASK);
if (phase != old_phase) {
old_phase = phase;
NCR5380_dprint_phase(NDEBUG_INFORMATION, instance);
}
#ifdef CONFIG_SUN3
if (phase == PHASE_CMDOUT &&
sun3_dma_setup_done != cmd) {
int count;
advance_sg_buffer(cmd);
count = sun3scsi_dma_xfer_len(hostdata, cmd);
if (count > 0) {
if (rq_data_dir(cmd->request))
sun3scsi_dma_send_setup(hostdata,
cmd->SCp.ptr, count);
else
sun3scsi_dma_recv_setup(hostdata,
cmd->SCp.ptr, count);
sun3_dma_setup_done = cmd;
}
#ifdef SUN3_SCSI_VME
dregs->csr |= CSR_INTR;
#endif
}
#endif /* CONFIG_SUN3 */
if (sink && (phase != PHASE_MSGOUT)) {
NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN |
ICR_ASSERT_ACK);
while (NCR5380_read(STATUS_REG) & SR_REQ)
;
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
ICR_ASSERT_ATN);
sink = 0;
continue;
}
switch (phase) {
case PHASE_DATAOUT:
#if (NDEBUG & NDEBUG_NO_DATAOUT)
shost_printk(KERN_DEBUG, instance, "NDEBUG_NO_DATAOUT set, attempted DATAOUT aborted\n");
sink = 1;
do_abort(instance);
cmd->result = DID_ERROR << 16;
complete_cmd(instance, cmd);
hostdata->connected = NULL;
hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun);
return;
#endif
case PHASE_DATAIN:
/*
* If there is no room left in the current buffer in the
* scatter-gather list, move onto the next one.
*/
advance_sg_buffer(cmd);
dsprintk(NDEBUG_INFORMATION, instance,
"this residual %d, sg ents %d\n",
cmd->SCp.this_residual,
sg_nents(cmd->SCp.buffer));
/*
* The preferred transfer method is going to be
* PSEUDO-DMA for systems that are strictly PIO,
* since we can let the hardware do the handshaking.
*
* For this to work, we need to know the transfersize
* ahead of time, since the pseudo-DMA code will sit
* in an unconditional loop.
*/
transfersize = 0;
if (!cmd->device->borken)
transfersize = NCR5380_dma_xfer_len(hostdata, cmd);
if (transfersize > 0) {
len = transfersize;
if (NCR5380_transfer_dma(instance, &phase,
&len, (unsigned char **)&cmd->SCp.ptr)) {
/*
* If the watchdog timer fires, all future
* accesses to this device will use the
* polled-IO.
*/
scmd_printk(KERN_INFO, cmd,
"switching to slow handshake\n");
cmd->device->borken = 1;
do_reset(instance);
bus_reset_cleanup(instance);
}
} else {
/* Transfer a small chunk so that the
* irq mode lock is not held too long.
*/
transfersize = min(cmd->SCp.this_residual,
NCR5380_PIO_CHUNK_SIZE);
len = transfersize;
NCR5380_transfer_pio(instance, &phase, &len,
(unsigned char **)&cmd->SCp.ptr);
cmd->SCp.this_residual -= transfersize - len;
ncr5380: Change instance->host_lock to hostdata->lock NCR5380.c presently uses the instance->host_lock spin lock. Convert this to a new spin lock that protects the NCR5380_hostdata struct. atari_NCR5380.c previously used local_irq_save/restore() rather than a spin lock. Convert this to hostdata->lock in irq mode. For SMP platforms, the interrupt handler now also acquires the spin lock. This brings all locking in the two core drivers into agreement. Adding this locking also means that a bunch of volatile qualifiers can be removed from the members of the NCR5380_hostdata struct. This is done in a subsequent patch. Proper locking will allow the abort handler to locate a command being aborted. This is presently impossible if the abort handler is invoked when the command has been moved from a queue to a pointer on the stack. (If eh_abort_handler can't determine whether a command has been completed or is still being processed then it can't decide whether to return success or failure.) The hostdata spin lock is now held when calling NCR5380_select() and NCR5380_information_transfer(). Where possible, the lock is dropped for polling and PIO transfers. Clean up the now-redundant SELECT_ENABLE_REG writes, that used to provide limited mutual exclusion between information_transfer() and reselect(). Accessing hostdata->connected without data races means taking the lock; cleanup these accesses. The new spin lock falls away for m68k and other UP builds, so this should have little impact there. In the SMP case the new lock should be uncontested even when the SCSI bus is contested. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:51 +08:00
}
#ifdef CONFIG_SUN3
if (sun3_dma_setup_done == cmd)
sun3_dma_setup_done = NULL;
#endif
return;
case PHASE_MSGIN:
len = 1;
data = &tmp;
NCR5380_transfer_pio(instance, &phase, &len, &data);
cmd->SCp.Message = tmp;
switch (tmp) {
case ABORT:
case COMMAND_COMPLETE:
/* Accept message by clearing ACK */
sink = 1;
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
dsprintk(NDEBUG_QUEUES, instance,
"COMMAND COMPLETE %p target %d lun %llu\n",
cmd, scmd_id(cmd), cmd->device->lun);
hostdata->connected = NULL;
hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun);
ncr5380: Fix autosense bugs NCR5380_information_transfer() may re-queue a command for autosense, after calling scsi_eh_prep_cmnd(). This creates several possibilities: 1. Reselection may intervene before the re-queued command gets processed. If the reconnected command then undergoes autosense, this causes the scsi_eh_save data from the previous command to be overwritten. 2. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(), a new REQUEST SENSE command may arrive. This would be queued ahead of any command already undergoing autosense, which means the scsi_eh_save data might be restored to the wrong command. 3. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(), eh_abort_handler() may abort the command. But the scsi_eh_save data is not discarded, which means the scsi_eh_save data might be incorrectly restored to the next REQUEST SENSE command issued. This patch adds a new autosense list so that commands that are re-queued because of a CHECK CONDITION result can be kept apart from the REQUEST SENSE commands that arrive via queuecommand. This patch also adds a function dedicated to dequeueing and preparing the next command for processing. By refactoring the main loop in this way, scsi_eh_save takes place when an autosense command is dequeued rather than when re-queued. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:06:00 +08:00
cmd->result &= ~0xffff;
cmd->result |= cmd->SCp.Status;
cmd->result |= cmd->SCp.Message << 8;
set_resid_from_SCp(cmd);
ncr5380: Fix autosense bugs NCR5380_information_transfer() may re-queue a command for autosense, after calling scsi_eh_prep_cmnd(). This creates several possibilities: 1. Reselection may intervene before the re-queued command gets processed. If the reconnected command then undergoes autosense, this causes the scsi_eh_save data from the previous command to be overwritten. 2. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(), a new REQUEST SENSE command may arrive. This would be queued ahead of any command already undergoing autosense, which means the scsi_eh_save data might be restored to the wrong command. 3. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(), eh_abort_handler() may abort the command. But the scsi_eh_save data is not discarded, which means the scsi_eh_save data might be incorrectly restored to the next REQUEST SENSE command issued. This patch adds a new autosense list so that commands that are re-queued because of a CHECK CONDITION result can be kept apart from the REQUEST SENSE commands that arrive via queuecommand. This patch also adds a function dedicated to dequeueing and preparing the next command for processing. By refactoring the main loop in this way, scsi_eh_save takes place when an autosense command is dequeued rather than when re-queued. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:06:00 +08:00
if (cmd->cmnd[0] == REQUEST_SENSE)
complete_cmd(instance, cmd);
ncr5380: Fix autosense bugs NCR5380_information_transfer() may re-queue a command for autosense, after calling scsi_eh_prep_cmnd(). This creates several possibilities: 1. Reselection may intervene before the re-queued command gets processed. If the reconnected command then undergoes autosense, this causes the scsi_eh_save data from the previous command to be overwritten. 2. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(), a new REQUEST SENSE command may arrive. This would be queued ahead of any command already undergoing autosense, which means the scsi_eh_save data might be restored to the wrong command. 3. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(), eh_abort_handler() may abort the command. But the scsi_eh_save data is not discarded, which means the scsi_eh_save data might be incorrectly restored to the next REQUEST SENSE command issued. This patch adds a new autosense list so that commands that are re-queued because of a CHECK CONDITION result can be kept apart from the REQUEST SENSE commands that arrive via queuecommand. This patch also adds a function dedicated to dequeueing and preparing the next command for processing. By refactoring the main loop in this way, scsi_eh_save takes place when an autosense command is dequeued rather than when re-queued. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:06:00 +08:00
else {
if (cmd->SCp.Status == SAM_STAT_CHECK_CONDITION ||
cmd->SCp.Status == SAM_STAT_COMMAND_TERMINATED) {
dsprintk(NDEBUG_QUEUES, instance, "autosense: adding cmd %p to tail of autosense queue\n",
cmd);
list_add_tail(&ncmd->list,
&hostdata->autosense);
} else
complete_cmd(instance, cmd);
}
/*
* Restore phase bits to 0 so an interrupted selection,
* arbitration can resume.
*/
NCR5380_write(TARGET_COMMAND_REG, 0);
maybe_release_dma_irq(instance);
return;
case MESSAGE_REJECT:
/* Accept message by clearing ACK */
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
switch (hostdata->last_message) {
case HEAD_OF_QUEUE_TAG:
case ORDERED_QUEUE_TAG:
case SIMPLE_QUEUE_TAG:
cmd->device->simple_tags = 0;
hostdata->busy[cmd->device->id] |= (1 << (cmd->device->lun & 0xFF));
break;
default:
break;
}
break;
case DISCONNECT:
/* Accept message by clearing ACK */
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
hostdata->connected = NULL;
list_add(&ncmd->list, &hostdata->disconnected);
dsprintk(NDEBUG_INFORMATION | NDEBUG_QUEUES,
instance, "connected command %p for target %d lun %llu moved to disconnected queue\n",
cmd, scmd_id(cmd), cmd->device->lun);
/*
* Restore phase bits to 0 so an interrupted selection,
* arbitration can resume.
*/
NCR5380_write(TARGET_COMMAND_REG, 0);
#ifdef SUN3_SCSI_VME
dregs->csr |= CSR_DMA_ENABLE;
#endif
return;
/*
* The SCSI data pointer is *IMPLICITLY* saved on a disconnect
* operation, in violation of the SCSI spec so we can safely
* ignore SAVE/RESTORE pointers calls.
*
* Unfortunately, some disks violate the SCSI spec and
* don't issue the required SAVE_POINTERS message before
* disconnecting, and we have to break spec to remain
* compatible.
*/
case SAVE_POINTERS:
case RESTORE_POINTERS:
/* Accept message by clearing ACK */
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
break;
case EXTENDED_MESSAGE:
/*
* Start the message buffer with the EXTENDED_MESSAGE
* byte, since spi_print_msg() wants the whole thing.
*/
extended_msg[0] = EXTENDED_MESSAGE;
/* Accept first byte by clearing ACK */
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
ncr5380: Change instance->host_lock to hostdata->lock NCR5380.c presently uses the instance->host_lock spin lock. Convert this to a new spin lock that protects the NCR5380_hostdata struct. atari_NCR5380.c previously used local_irq_save/restore() rather than a spin lock. Convert this to hostdata->lock in irq mode. For SMP platforms, the interrupt handler now also acquires the spin lock. This brings all locking in the two core drivers into agreement. Adding this locking also means that a bunch of volatile qualifiers can be removed from the members of the NCR5380_hostdata struct. This is done in a subsequent patch. Proper locking will allow the abort handler to locate a command being aborted. This is presently impossible if the abort handler is invoked when the command has been moved from a queue to a pointer on the stack. (If eh_abort_handler can't determine whether a command has been completed or is still being processed then it can't decide whether to return success or failure.) The hostdata spin lock is now held when calling NCR5380_select() and NCR5380_information_transfer(). Where possible, the lock is dropped for polling and PIO transfers. Clean up the now-redundant SELECT_ENABLE_REG writes, that used to provide limited mutual exclusion between information_transfer() and reselect(). Accessing hostdata->connected without data races means taking the lock; cleanup these accesses. The new spin lock falls away for m68k and other UP builds, so this should have little impact there. In the SMP case the new lock should be uncontested even when the SCSI bus is contested. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:51 +08:00
spin_unlock_irq(&hostdata->lock);
dsprintk(NDEBUG_EXTENDED, instance, "receiving extended message\n");
len = 2;
data = extended_msg + 1;
phase = PHASE_MSGIN;
NCR5380_transfer_pio(instance, &phase, &len, &data);
dsprintk(NDEBUG_EXTENDED, instance, "length %d, code 0x%02x\n",
(int)extended_msg[1],
(int)extended_msg[2]);
if (!len && extended_msg[1] > 0 &&
extended_msg[1] <= sizeof(extended_msg) - 2) {
/* Accept third byte by clearing ACK */
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
len = extended_msg[1] - 1;
data = extended_msg + 3;
phase = PHASE_MSGIN;
NCR5380_transfer_pio(instance, &phase, &len, &data);
dsprintk(NDEBUG_EXTENDED, instance, "message received, residual %d\n",
len);
switch (extended_msg[2]) {
case EXTENDED_SDTR:
case EXTENDED_WDTR:
tmp = 0;
}
} else if (len) {
shost_printk(KERN_ERR, instance, "error receiving extended message\n");
tmp = 0;
} else {
shost_printk(KERN_NOTICE, instance, "extended message code %02x length %d is too long\n",
extended_msg[2], extended_msg[1]);
tmp = 0;
}
ncr5380: Change instance->host_lock to hostdata->lock NCR5380.c presently uses the instance->host_lock spin lock. Convert this to a new spin lock that protects the NCR5380_hostdata struct. atari_NCR5380.c previously used local_irq_save/restore() rather than a spin lock. Convert this to hostdata->lock in irq mode. For SMP platforms, the interrupt handler now also acquires the spin lock. This brings all locking in the two core drivers into agreement. Adding this locking also means that a bunch of volatile qualifiers can be removed from the members of the NCR5380_hostdata struct. This is done in a subsequent patch. Proper locking will allow the abort handler to locate a command being aborted. This is presently impossible if the abort handler is invoked when the command has been moved from a queue to a pointer on the stack. (If eh_abort_handler can't determine whether a command has been completed or is still being processed then it can't decide whether to return success or failure.) The hostdata spin lock is now held when calling NCR5380_select() and NCR5380_information_transfer(). Where possible, the lock is dropped for polling and PIO transfers. Clean up the now-redundant SELECT_ENABLE_REG writes, that used to provide limited mutual exclusion between information_transfer() and reselect(). Accessing hostdata->connected without data races means taking the lock; cleanup these accesses. The new spin lock falls away for m68k and other UP builds, so this should have little impact there. In the SMP case the new lock should be uncontested even when the SCSI bus is contested. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:51 +08:00
spin_lock_irq(&hostdata->lock);
if (!hostdata->connected)
return;
/* Reject message */
/* Fall through */
default:
/*
* If we get something weird that we aren't expecting,
* log it.
*/
if (tmp == EXTENDED_MESSAGE)
scmd_printk(KERN_INFO, cmd,
"rejecting unknown extended message code %02x, length %d\n",
extended_msg[2], extended_msg[1]);
else if (tmp)
scmd_printk(KERN_INFO, cmd,
"rejecting unknown message code %02x\n",
tmp);
msgout = MESSAGE_REJECT;
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
break;
} /* switch (tmp) */
break;
case PHASE_MSGOUT:
len = 1;
data = &msgout;
hostdata->last_message = msgout;
NCR5380_transfer_pio(instance, &phase, &len, &data);
if (msgout == ABORT) {
hostdata->connected = NULL;
hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun);
cmd->result = DID_ERROR << 16;
complete_cmd(instance, cmd);
maybe_release_dma_irq(instance);
return;
}
msgout = NOP;
break;
case PHASE_CMDOUT:
len = cmd->cmd_len;
data = cmd->cmnd;
/*
* XXX for performance reasons, on machines with a
* PSEUDO-DMA architecture we should probably
* use the dma transfer function.
*/
NCR5380_transfer_pio(instance, &phase, &len, &data);
break;
case PHASE_STATIN:
len = 1;
data = &tmp;
NCR5380_transfer_pio(instance, &phase, &len, &data);
cmd->SCp.Status = tmp;
break;
default:
shost_printk(KERN_ERR, instance, "unknown phase\n");
NCR5380_dprint(NDEBUG_ANY, instance);
} /* switch(phase) */
ncr5380: Rework disconnect versus poll logic The atari_NCR5380.c and NCR5380.c core drivers differ in their handling of target disconnection. This is partly because atari_NCR5380.c had all of the polling and sleeping removed to become entirely interrupt-driven, and it is partly because of damage done to NCR5380.c after atari_NCR5380.c was forked. See commit 37cd23b44929 ("Linux 2.1.105") in history/history.git. The polling changes that were made in v2.1.105 are questionable at best: if REQ is not already asserted when NCR5380_transfer_pio() is invoked, and if the expected phase is DATA IN or DATA OUT, the function will schedule main() to execute after USLEEP_SLEEP jiffies and then return. The problems here are the expected REQ timing and the sleep interval*. Avoid this issue by using NCR5380_poll_politely() instead of scheduling main(). The atari_NCR5380.c core driver requires the use of the chip interrupt and always permits target disconnection. It sets the cmd->device->disconnect flag when a device disconnects, but never tests this flag. The NCR5380.c core driver permits disconnection only when instance->irq != NO_IRQ. It sets the cmd->device->disconnect flag when a device disconnects and it tests this flag in a couple of places: 1. During NCR5380_information_transfer(), following COMMAND OUT phase, if !cmd->device->disconnect, the initiator will take a guess as to whether or not the target will then choose to go to MESSAGE IN phase and disconnect. If the driver guesses "yes", it will schedule main() to execute after USLEEP_SLEEP jiffies and then return there. Unfortunately the driver may guess "yes" even after it has denied the target the disconnection privilege. When the target does not disconnect, the sleep can be beneficial, assuming the sleep interval is appropriate (mostly it is not*). And even if the driver guesses "yes" correctly, and the target would then disconnect, the driver still has to go through the MESSAGE IN phase in order to get to BUS FREE phase. The main loop can do nothing useful until BUS FREE, and sleeping just delays the phase transition. 2. If !cmd->device->disconnect and REQ is not already asserted when NCR5380_information_transfer() is invoked, the function polls for REQ for USLEEP_POLL jiffies. If REQ is not asserted, it then schedules main() to execute after USLEEP_SLEEP jiffies and returns. The idea is apparently to yeild the CPU while waiting for REQ. This is conditional upon !cmd->device->disconnect, but there seems to be no rhyme or reason for that. For example, the flag may be unset because disconnection privilege was denied because the driver has no IRQ. Or the flag may be unset because the device has never needed to disconnect before. Or if the flag is set, disconnection may have no relevance to the present bus phase. Another deficiency of the existing algorithm is as follows. When the driver has no IRQ, it prevents disconnection, and generally polls and sleeps more than it would normally. Now, if the driver is going to poll anyway, why not allow the target to disconnect? That way the driver can do something useful with the bus instead of polling unproductively! Avoid this pointless latency, complexity and guesswork by using NCR5380_poll_politely() instead of scheduling main(). * For g_NCR5380, the time intervals for USLEEP_SLEEP and USLEEP_POLL are 200 ms and 10 ms, respectively. They are 20 ms and 200 ms respectively for the other NCR5380 drivers. There doesn't seem to be any reason for this discrepancy. The timing seems to have no relation to the type of adapter. Bizarrely, the timing in g_NCR5380 seems to relate only to one particular type of target device. This patch attempts to solve the problem for all NCR5380 drivers and all target devices. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:26 +08:00
} else {
ncr5380: Change instance->host_lock to hostdata->lock NCR5380.c presently uses the instance->host_lock spin lock. Convert this to a new spin lock that protects the NCR5380_hostdata struct. atari_NCR5380.c previously used local_irq_save/restore() rather than a spin lock. Convert this to hostdata->lock in irq mode. For SMP platforms, the interrupt handler now also acquires the spin lock. This brings all locking in the two core drivers into agreement. Adding this locking also means that a bunch of volatile qualifiers can be removed from the members of the NCR5380_hostdata struct. This is done in a subsequent patch. Proper locking will allow the abort handler to locate a command being aborted. This is presently impossible if the abort handler is invoked when the command has been moved from a queue to a pointer on the stack. (If eh_abort_handler can't determine whether a command has been completed or is still being processed then it can't decide whether to return success or failure.) The hostdata spin lock is now held when calling NCR5380_select() and NCR5380_information_transfer(). Where possible, the lock is dropped for polling and PIO transfers. Clean up the now-redundant SELECT_ENABLE_REG writes, that used to provide limited mutual exclusion between information_transfer() and reselect(). Accessing hostdata->connected without data races means taking the lock; cleanup these accesses. The new spin lock falls away for m68k and other UP builds, so this should have little impact there. In the SMP case the new lock should be uncontested even when the SCSI bus is contested. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:51 +08:00
spin_unlock_irq(&hostdata->lock);
NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ);
ncr5380: Change instance->host_lock to hostdata->lock NCR5380.c presently uses the instance->host_lock spin lock. Convert this to a new spin lock that protects the NCR5380_hostdata struct. atari_NCR5380.c previously used local_irq_save/restore() rather than a spin lock. Convert this to hostdata->lock in irq mode. For SMP platforms, the interrupt handler now also acquires the spin lock. This brings all locking in the two core drivers into agreement. Adding this locking also means that a bunch of volatile qualifiers can be removed from the members of the NCR5380_hostdata struct. This is done in a subsequent patch. Proper locking will allow the abort handler to locate a command being aborted. This is presently impossible if the abort handler is invoked when the command has been moved from a queue to a pointer on the stack. (If eh_abort_handler can't determine whether a command has been completed or is still being processed then it can't decide whether to return success or failure.) The hostdata spin lock is now held when calling NCR5380_select() and NCR5380_information_transfer(). Where possible, the lock is dropped for polling and PIO transfers. Clean up the now-redundant SELECT_ENABLE_REG writes, that used to provide limited mutual exclusion between information_transfer() and reselect(). Accessing hostdata->connected without data races means taking the lock; cleanup these accesses. The new spin lock falls away for m68k and other UP builds, so this should have little impact there. In the SMP case the new lock should be uncontested even when the SCSI bus is contested. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:51 +08:00
spin_lock_irq(&hostdata->lock);
}
ncr5380: Change instance->host_lock to hostdata->lock NCR5380.c presently uses the instance->host_lock spin lock. Convert this to a new spin lock that protects the NCR5380_hostdata struct. atari_NCR5380.c previously used local_irq_save/restore() rather than a spin lock. Convert this to hostdata->lock in irq mode. For SMP platforms, the interrupt handler now also acquires the spin lock. This brings all locking in the two core drivers into agreement. Adding this locking also means that a bunch of volatile qualifiers can be removed from the members of the NCR5380_hostdata struct. This is done in a subsequent patch. Proper locking will allow the abort handler to locate a command being aborted. This is presently impossible if the abort handler is invoked when the command has been moved from a queue to a pointer on the stack. (If eh_abort_handler can't determine whether a command has been completed or is still being processed then it can't decide whether to return success or failure.) The hostdata spin lock is now held when calling NCR5380_select() and NCR5380_information_transfer(). Where possible, the lock is dropped for polling and PIO transfers. Clean up the now-redundant SELECT_ENABLE_REG writes, that used to provide limited mutual exclusion between information_transfer() and reselect(). Accessing hostdata->connected without data races means taking the lock; cleanup these accesses. The new spin lock falls away for m68k and other UP builds, so this should have little impact there. In the SMP case the new lock should be uncontested even when the SCSI bus is contested. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:51 +08:00
}
}
/*
* Function : void NCR5380_reselect (struct Scsi_Host *instance)
*
* Purpose : does reselection, initializing the instance->connected
* field to point to the scsi_cmnd for which the I_T_L or I_T_L_Q
* nexus has been reestablished,
*
* Inputs : instance - this instance of the NCR5380.
*/
static void NCR5380_reselect(struct Scsi_Host *instance)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
unsigned char target_mask;
unsigned char lun;
unsigned char msg[3];
struct NCR5380_cmd *ncmd;
struct scsi_cmnd *tmp;
/*
* Disable arbitration, etc. since the host adapter obviously
* lost, and tell an interrupted NCR5380_select() to restart.
*/
NCR5380_write(MODE_REG, MR_BASE);
target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);
if (!target_mask || target_mask & (target_mask - 1)) {
shost_printk(KERN_WARNING, instance,
"reselect: bad target_mask 0x%02x\n", target_mask);
return;
}
/*
* At this point, we have detected that our SCSI ID is on the bus,
* SEL is true and BSY was false for at least one bus settle delay
* (400 ns).
*
* We must assert BSY ourselves, until the target drops the SEL
* signal.
*/
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
if (NCR5380_poll_politely(hostdata,
STATUS_REG, SR_SEL, 0, 2 * HZ) < 0) {
shost_printk(KERN_ERR, instance, "reselect: !SEL timeout\n");
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
return;
}
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
/*
* Wait for target to go into MSGIN.
*/
if (NCR5380_poll_politely(hostdata,
STATUS_REG, SR_REQ, SR_REQ, 2 * HZ) < 0) {
if ((NCR5380_read(STATUS_REG) & (SR_BSY | SR_SEL)) == 0)
/* BUS FREE phase */
return;
shost_printk(KERN_ERR, instance, "reselect: REQ timeout\n");
do_abort(instance);
return;
}
#ifdef CONFIG_SUN3
/* acknowledge toggle to MSGIN */
NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(PHASE_MSGIN));
/* peek at the byte without really hitting the bus */
msg[0] = NCR5380_read(CURRENT_SCSI_DATA_REG);
#else
{
int len = 1;
unsigned char *data = msg;
unsigned char phase = PHASE_MSGIN;
NCR5380_transfer_pio(instance, &phase, &len, &data);
if (len) {
do_abort(instance);
return;
}
}
#endif /* CONFIG_SUN3 */
if (!(msg[0] & 0x80)) {
shost_printk(KERN_ERR, instance, "expecting IDENTIFY message, got ");
spi_print_msg(msg);
printk("\n");
do_abort(instance);
return;
}
lun = msg[0] & 0x07;
/*
* We need to add code for SCSI-II to track which devices have
* I_T_L_Q nexuses established, and which have simple I_T_L
* nexuses so we can chose to do additional data transfer.
*/
/*
* Find the command corresponding to the I_T_L or I_T_L_Q nexus we
* just reestablished, and remove it from the disconnected queue.
*/
tmp = NULL;
list_for_each_entry(ncmd, &hostdata->disconnected, list) {
struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
if (target_mask == (1 << scmd_id(cmd)) &&
lun == (u8)cmd->device->lun) {
list_del(&ncmd->list);
tmp = cmd;
break;
}
}
if (tmp) {
dsprintk(NDEBUG_RESELECTION | NDEBUG_QUEUES, instance,
"reselect: removed %p from disconnected queue\n", tmp);
} else {
int target = ffs(target_mask) - 1;
shost_printk(KERN_ERR, instance, "target bitmask 0x%02x lun %d not in disconnected queue.\n",
target_mask, lun);
/*
* Since we have an established nexus that we can't do anything
* with, we must abort it.
*/
if (do_abort(instance) == 0)
hostdata->busy[target] &= ~(1 << lun);
return;
}
#ifdef CONFIG_SUN3
if (sun3_dma_setup_done != tmp) {
int count;
advance_sg_buffer(tmp);
count = sun3scsi_dma_xfer_len(hostdata, tmp);
if (count > 0) {
if (rq_data_dir(tmp->request))
sun3scsi_dma_send_setup(hostdata,
tmp->SCp.ptr, count);
else
sun3scsi_dma_recv_setup(hostdata,
tmp->SCp.ptr, count);
sun3_dma_setup_done = tmp;
}
}
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
#endif /* CONFIG_SUN3 */
/* Accept message by clearing ACK */
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
hostdata->connected = tmp;
ncr5380: Remove disused atari_NCR5380.c core driver Now that atari_scsi and sun3_scsi have been converted to use the NCR5380.c core driver, remove atari_NCR5380.c. Also remove the last vestiges of its Tagged Command Queueing implementation from the wrapper drivers. The TCQ support in atari_NCR5380.c is abandoned by this patch. It is not merged into the remaining core driver because, 1) atari_scsi defines SUPPORT_TAGS but leaves FLAG_TAGGED_QUEUING disabled by default, which indicates that it is mostly undesirable. 2) I'm told that it doesn't work correctly when enabled. 3) The algorithm does not make use of block layer tags which it will have to do because scmd->tag is deprecated. 4) sun3_scsi doesn't define SUPPORT_TAGS at all, yet the the SUPPORT_TAGS macro interacts with the CONFIG_SUN3 macro in 'interesting' ways. 5) Compile-time configuration with macros like SUPPORT_TAGS caused the configuration space to explode, leading to untestable and unmaintainable code that is too hard to reason about. The merge_contiguous_buffers() code is also abandoned. This was unused by sun3_scsi. Only atari_scsi used it and then only on TT, because only TT supports scatter/gather. I suspect that the TT would work fine with ENABLE_CLUSTERING instead. If someone can benchmark the difference then perhaps the merge_contiguous_buffers() code can be be justified. Until then we are better off without the extra complexity. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-23 18:10:22 +08:00
dsprintk(NDEBUG_RESELECTION, instance, "nexus established, target %d, lun %llu\n",
scmd_id(tmp), tmp->device->lun);
}
/**
* list_find_cmd - test for presence of a command in a linked list
* @haystack: list of commands
* @needle: command to search for
*/
static bool list_find_cmd(struct list_head *haystack,
struct scsi_cmnd *needle)
{
struct NCR5380_cmd *ncmd;
list_for_each_entry(ncmd, haystack, list)
if (NCR5380_to_scmd(ncmd) == needle)
return true;
return false;
}
/**
* list_remove_cmd - remove a command from linked list
* @haystack: list of commands
* @needle: command to remove
*/
static bool list_del_cmd(struct list_head *haystack,
struct scsi_cmnd *needle)
{
if (list_find_cmd(haystack, needle)) {
struct NCR5380_cmd *ncmd = scsi_cmd_priv(needle);
list_del(&ncmd->list);
return true;
}
return false;
}
/**
* NCR5380_abort - scsi host eh_abort_handler() method
* @cmd: the command to be aborted
*
* Try to abort a given command by removing it from queues and/or sending
* the target an abort message. This may not succeed in causing a target
* to abort the command. Nonetheless, the low-level driver must forget about
* the command because the mid-layer reclaims it and it may be re-issued.
*
* The normal path taken by a command is as follows. For EH we trace this
* same path to locate and abort the command.
*
* unissued -> selecting -> [unissued -> selecting ->]... connected ->
* [disconnected -> connected ->]...
* [autosense -> connected ->] done
*
* If cmd was not found at all then presumably it has already been completed,
* in which case return SUCCESS to try to avoid further EH measures.
*
* If the command has not completed yet, we must not fail to find it.
* We have no option but to forget the aborted command (even if it still
* lacks sense data). The mid-layer may re-issue a command that is in error
* recovery (see scsi_send_eh_cmnd), but the logic and data structures in
* this driver are such that a command can appear on one queue only.
*
* The lock protects driver data structures, but EH handlers also use it
* to serialize their own execution and prevent their own re-entry.
*/
static int NCR5380_abort(struct scsi_cmnd *cmd)
{
struct Scsi_Host *instance = cmd->device->host;
struct NCR5380_hostdata *hostdata = shost_priv(instance);
ncr5380: Change instance->host_lock to hostdata->lock NCR5380.c presently uses the instance->host_lock spin lock. Convert this to a new spin lock that protects the NCR5380_hostdata struct. atari_NCR5380.c previously used local_irq_save/restore() rather than a spin lock. Convert this to hostdata->lock in irq mode. For SMP platforms, the interrupt handler now also acquires the spin lock. This brings all locking in the two core drivers into agreement. Adding this locking also means that a bunch of volatile qualifiers can be removed from the members of the NCR5380_hostdata struct. This is done in a subsequent patch. Proper locking will allow the abort handler to locate a command being aborted. This is presently impossible if the abort handler is invoked when the command has been moved from a queue to a pointer on the stack. (If eh_abort_handler can't determine whether a command has been completed or is still being processed then it can't decide whether to return success or failure.) The hostdata spin lock is now held when calling NCR5380_select() and NCR5380_information_transfer(). Where possible, the lock is dropped for polling and PIO transfers. Clean up the now-redundant SELECT_ENABLE_REG writes, that used to provide limited mutual exclusion between information_transfer() and reselect(). Accessing hostdata->connected without data races means taking the lock; cleanup these accesses. The new spin lock falls away for m68k and other UP builds, so this should have little impact there. In the SMP case the new lock should be uncontested even when the SCSI bus is contested. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:51 +08:00
unsigned long flags;
int result = SUCCESS;
ncr5380: Change instance->host_lock to hostdata->lock NCR5380.c presently uses the instance->host_lock spin lock. Convert this to a new spin lock that protects the NCR5380_hostdata struct. atari_NCR5380.c previously used local_irq_save/restore() rather than a spin lock. Convert this to hostdata->lock in irq mode. For SMP platforms, the interrupt handler now also acquires the spin lock. This brings all locking in the two core drivers into agreement. Adding this locking also means that a bunch of volatile qualifiers can be removed from the members of the NCR5380_hostdata struct. This is done in a subsequent patch. Proper locking will allow the abort handler to locate a command being aborted. This is presently impossible if the abort handler is invoked when the command has been moved from a queue to a pointer on the stack. (If eh_abort_handler can't determine whether a command has been completed or is still being processed then it can't decide whether to return success or failure.) The hostdata spin lock is now held when calling NCR5380_select() and NCR5380_information_transfer(). Where possible, the lock is dropped for polling and PIO transfers. Clean up the now-redundant SELECT_ENABLE_REG writes, that used to provide limited mutual exclusion between information_transfer() and reselect(). Accessing hostdata->connected without data races means taking the lock; cleanup these accesses. The new spin lock falls away for m68k and other UP builds, so this should have little impact there. In the SMP case the new lock should be uncontested even when the SCSI bus is contested. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:51 +08:00
spin_lock_irqsave(&hostdata->lock, flags);
#if (NDEBUG & NDEBUG_ANY)
scmd_printk(KERN_INFO, cmd, __func__);
#endif
NCR5380_dprint(NDEBUG_ANY, instance);
NCR5380_dprint_phase(NDEBUG_ANY, instance);
if (list_del_cmd(&hostdata->unissued, cmd)) {
dsprintk(NDEBUG_ABORT, instance,
"abort: removed %p from issue queue\n", cmd);
cmd->result = DID_ABORT << 16;
cmd->scsi_done(cmd); /* No tag or busy flag to worry about */
goto out;
}
if (hostdata->selecting == cmd) {
dsprintk(NDEBUG_ABORT, instance,
"abort: cmd %p == selecting\n", cmd);
hostdata->selecting = NULL;
cmd->result = DID_ABORT << 16;
complete_cmd(instance, cmd);
goto out;
}
if (list_del_cmd(&hostdata->disconnected, cmd)) {
dsprintk(NDEBUG_ABORT, instance,
"abort: removed %p from disconnected list\n", cmd);
/* Can't call NCR5380_select() and send ABORT because that
* means releasing the lock. Need a bus reset.
*/
set_host_byte(cmd, DID_ERROR);
complete_cmd(instance, cmd);
result = FAILED;
goto out;
}
if (hostdata->connected == cmd) {
dsprintk(NDEBUG_ABORT, instance, "abort: cmd %p is connected\n", cmd);
hostdata->connected = NULL;
hostdata->dma_len = 0;
if (do_abort(instance) < 0) {
set_host_byte(cmd, DID_ERROR);
complete_cmd(instance, cmd);
result = FAILED;
goto out;
}
set_host_byte(cmd, DID_ABORT);
complete_cmd(instance, cmd);
goto out;
}
if (list_del_cmd(&hostdata->autosense, cmd)) {
dsprintk(NDEBUG_ABORT, instance,
"abort: removed %p from sense queue\n", cmd);
complete_cmd(instance, cmd);
}
out:
if (result == FAILED)
dsprintk(NDEBUG_ABORT, instance, "abort: failed to abort %p\n", cmd);
else {
hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun);
dsprintk(NDEBUG_ABORT, instance, "abort: successfully aborted %p\n", cmd);
}
queue_work(hostdata->work_q, &hostdata->main_task);
maybe_release_dma_irq(instance);
ncr5380: Change instance->host_lock to hostdata->lock NCR5380.c presently uses the instance->host_lock spin lock. Convert this to a new spin lock that protects the NCR5380_hostdata struct. atari_NCR5380.c previously used local_irq_save/restore() rather than a spin lock. Convert this to hostdata->lock in irq mode. For SMP platforms, the interrupt handler now also acquires the spin lock. This brings all locking in the two core drivers into agreement. Adding this locking also means that a bunch of volatile qualifiers can be removed from the members of the NCR5380_hostdata struct. This is done in a subsequent patch. Proper locking will allow the abort handler to locate a command being aborted. This is presently impossible if the abort handler is invoked when the command has been moved from a queue to a pointer on the stack. (If eh_abort_handler can't determine whether a command has been completed or is still being processed then it can't decide whether to return success or failure.) The hostdata spin lock is now held when calling NCR5380_select() and NCR5380_information_transfer(). Where possible, the lock is dropped for polling and PIO transfers. Clean up the now-redundant SELECT_ENABLE_REG writes, that used to provide limited mutual exclusion between information_transfer() and reselect(). Accessing hostdata->connected without data races means taking the lock; cleanup these accesses. The new spin lock falls away for m68k and other UP builds, so this should have little impact there. In the SMP case the new lock should be uncontested even when the SCSI bus is contested. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:51 +08:00
spin_unlock_irqrestore(&hostdata->lock, flags);
return result;
}
static void bus_reset_cleanup(struct Scsi_Host *instance)
{
ncr5380: Change instance->host_lock to hostdata->lock NCR5380.c presently uses the instance->host_lock spin lock. Convert this to a new spin lock that protects the NCR5380_hostdata struct. atari_NCR5380.c previously used local_irq_save/restore() rather than a spin lock. Convert this to hostdata->lock in irq mode. For SMP platforms, the interrupt handler now also acquires the spin lock. This brings all locking in the two core drivers into agreement. Adding this locking also means that a bunch of volatile qualifiers can be removed from the members of the NCR5380_hostdata struct. This is done in a subsequent patch. Proper locking will allow the abort handler to locate a command being aborted. This is presently impossible if the abort handler is invoked when the command has been moved from a queue to a pointer on the stack. (If eh_abort_handler can't determine whether a command has been completed or is still being processed then it can't decide whether to return success or failure.) The hostdata spin lock is now held when calling NCR5380_select() and NCR5380_information_transfer(). Where possible, the lock is dropped for polling and PIO transfers. Clean up the now-redundant SELECT_ENABLE_REG writes, that used to provide limited mutual exclusion between information_transfer() and reselect(). Accessing hostdata->connected without data races means taking the lock; cleanup these accesses. The new spin lock falls away for m68k and other UP builds, so this should have little impact there. In the SMP case the new lock should be uncontested even when the SCSI bus is contested. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:51 +08:00
struct NCR5380_hostdata *hostdata = shost_priv(instance);
int i;
struct NCR5380_cmd *ncmd;
/* reset NCR registers */
NCR5380_write(MODE_REG, MR_BASE);
NCR5380_write(TARGET_COMMAND_REG, 0);
NCR5380_write(SELECT_ENABLE_REG, 0);
/* After the reset, there are no more connected or disconnected commands
* and no busy units; so clear the low-level status here to avoid
* conflicts when the mid-level code tries to wake up the affected
* commands!
*/
if (hostdata->selecting) {
hostdata->selecting->result = DID_RESET << 16;
complete_cmd(instance, hostdata->selecting);
hostdata->selecting = NULL;
}
list_for_each_entry(ncmd, &hostdata->disconnected, list) {
struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
set_host_byte(cmd, DID_RESET);
complete_cmd(instance, cmd);
}
INIT_LIST_HEAD(&hostdata->disconnected);
list_for_each_entry(ncmd, &hostdata->autosense, list) {
struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
cmd->scsi_done(cmd);
}
INIT_LIST_HEAD(&hostdata->autosense);
if (hostdata->connected) {
set_host_byte(hostdata->connected, DID_RESET);
complete_cmd(instance, hostdata->connected);
hostdata->connected = NULL;
}
for (i = 0; i < 8; ++i)
hostdata->busy[i] = 0;
hostdata->dma_len = 0;
queue_work(hostdata->work_q, &hostdata->main_task);
maybe_release_dma_irq(instance);
}
/**
* NCR5380_host_reset - reset the SCSI host
* @cmd: SCSI command undergoing EH
*
* Returns SUCCESS
*/
static int NCR5380_host_reset(struct scsi_cmnd *cmd)
{
struct Scsi_Host *instance = cmd->device->host;
struct NCR5380_hostdata *hostdata = shost_priv(instance);
unsigned long flags;
struct NCR5380_cmd *ncmd;
spin_lock_irqsave(&hostdata->lock, flags);
#if (NDEBUG & NDEBUG_ANY)
shost_printk(KERN_INFO, instance, __func__);
#endif
NCR5380_dprint(NDEBUG_ANY, instance);
NCR5380_dprint_phase(NDEBUG_ANY, instance);
list_for_each_entry(ncmd, &hostdata->unissued, list) {
struct scsi_cmnd *scmd = NCR5380_to_scmd(ncmd);
scmd->result = DID_RESET << 16;
scmd->scsi_done(scmd);
}
INIT_LIST_HEAD(&hostdata->unissued);
do_reset(instance);
bus_reset_cleanup(instance);
ncr5380: Change instance->host_lock to hostdata->lock NCR5380.c presently uses the instance->host_lock spin lock. Convert this to a new spin lock that protects the NCR5380_hostdata struct. atari_NCR5380.c previously used local_irq_save/restore() rather than a spin lock. Convert this to hostdata->lock in irq mode. For SMP platforms, the interrupt handler now also acquires the spin lock. This brings all locking in the two core drivers into agreement. Adding this locking also means that a bunch of volatile qualifiers can be removed from the members of the NCR5380_hostdata struct. This is done in a subsequent patch. Proper locking will allow the abort handler to locate a command being aborted. This is presently impossible if the abort handler is invoked when the command has been moved from a queue to a pointer on the stack. (If eh_abort_handler can't determine whether a command has been completed or is still being processed then it can't decide whether to return success or failure.) The hostdata spin lock is now held when calling NCR5380_select() and NCR5380_information_transfer(). Where possible, the lock is dropped for polling and PIO transfers. Clean up the now-redundant SELECT_ENABLE_REG writes, that used to provide limited mutual exclusion between information_transfer() and reselect(). Accessing hostdata->connected without data races means taking the lock; cleanup these accesses. The new spin lock falls away for m68k and other UP builds, so this should have little impact there. In the SMP case the new lock should be uncontested even when the SCSI bus is contested. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-03 13:05:51 +08:00
spin_unlock_irqrestore(&hostdata->lock, flags);
return SUCCESS;
}