fadump: Register for firmware assisted dump.

On 2012-02-20 11:02:51 Mon, Paul Mackerras wrote:
> On Thu, Feb 16, 2012 at 04:44:30PM +0530, Mahesh J Salgaonkar wrote:
>
> If I have read the code correctly, we are going to get this printk on
> non-pSeries machines or on older pSeries machines, even if the user
> has not put the fadump=on option on the kernel command line.  The
> printk will be annoying since there is no actual error condition.  It
> seems to me that the condition for the printk should include
> fw_dump.fadump_enabled.  In other words you should probably add
>
> 	if (!fw_dump.fadump_enabled)
> 		return 0;
>
> at the beginning of the function.

Hi Paul,

Thanks for pointing it out. Please find the updated patch below.

The existing patches above this (4/10 through 10/10) cleanly applies
on this update.

Thanks,
-Mahesh.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Mahesh Salgaonkar 2012-02-20 02:15:03 +00:00 committed by Benjamin Herrenschmidt
parent eb39c8803d
commit 3ccc00a7e0
4 changed files with 427 additions and 4 deletions

View File

@ -48,6 +48,58 @@
#define FADUMP_HPTE_REGION 0x0002
#define FADUMP_REAL_MODE_REGION 0x0011
/* Dump request flag */
#define FADUMP_REQUEST_FLAG 0x00000001
/* FAD commands */
#define FADUMP_REGISTER 1
#define FADUMP_UNREGISTER 2
#define FADUMP_INVALIDATE 3
/* Kernel Dump section info */
struct fadump_section {
u32 request_flag;
u16 source_data_type;
u16 error_flags;
u64 source_address;
u64 source_len;
u64 bytes_dumped;
u64 destination_address;
};
/* ibm,configure-kernel-dump header. */
struct fadump_section_header {
u32 dump_format_version;
u16 dump_num_sections;
u16 dump_status_flag;
u32 offset_first_dump_section;
/* Fields for disk dump option. */
u32 dd_block_size;
u64 dd_block_offset;
u64 dd_num_blocks;
u32 dd_offset_disk_path;
/* Maximum time allowed to prevent an automatic dump-reboot. */
u32 max_time_auto;
};
/*
* Firmware Assisted dump memory structure. This structure is required for
* registering future kernel dump with power firmware through rtas call.
*
* No disk dump option. Hence disk dump path string section is not included.
*/
struct fadump_mem_struct {
struct fadump_section_header header;
/* Kernel dump sections */
struct fadump_section cpu_state_data;
struct fadump_section hpte_region;
struct fadump_section rmr_region;
};
/* Firmware-assisted dump configuration details. */
struct fw_dump {
unsigned long cpu_state_data_size;
unsigned long hpte_region_size;
@ -62,10 +114,15 @@ struct fw_dump {
unsigned long fadump_enabled:1;
unsigned long fadump_supported:1;
unsigned long dump_active:1;
unsigned long dump_registered:1;
};
extern int early_init_dt_scan_fw_dump(unsigned long node,
const char *uname, int depth, void *data);
extern int fadump_reserve_mem(void);
extern int setup_fadump(void);
extern int is_fadump_active(void);
#else /* CONFIG_FA_DUMP */
static inline int is_fadump_active(void) { return 0; }
#endif
#endif

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@ -29,6 +29,9 @@
#include <linux/string.h>
#include <linux/memblock.h>
#include <linux/delay.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <asm/page.h>
#include <asm/prom.h>
@ -36,6 +39,10 @@
#include <asm/fadump.h>
static struct fw_dump fw_dump;
static struct fadump_mem_struct fdm;
static const struct fadump_mem_struct *fdm_active;
static DEFINE_MUTEX(fadump_mutex);
/* Scan the Firmware Assisted dump configuration details. */
int __init early_init_dt_scan_fw_dump(unsigned long node,
@ -64,7 +71,8 @@ int __init early_init_dt_scan_fw_dump(unsigned long node,
* The 'ibm,kernel-dump' rtas node is present only if there is
* dump data waiting for us.
*/
if (of_get_flat_dt_prop(node, "ibm,kernel-dump", NULL))
fdm_active = of_get_flat_dt_prop(node, "ibm,kernel-dump", NULL);
if (fdm_active)
fw_dump.dump_active = 1;
/* Get the sizes required to store dump data for the firmware provided
@ -98,6 +106,85 @@ int __init early_init_dt_scan_fw_dump(unsigned long node,
return 1;
}
int is_fadump_active(void)
{
return fw_dump.dump_active;
}
/* Print firmware assisted dump configurations for debugging purpose. */
static void fadump_show_config(void)
{
pr_debug("Support for firmware-assisted dump (fadump): %s\n",
(fw_dump.fadump_supported ? "present" : "no support"));
if (!fw_dump.fadump_supported)
return;
pr_debug("Fadump enabled : %s\n",
(fw_dump.fadump_enabled ? "yes" : "no"));
pr_debug("Dump Active : %s\n",
(fw_dump.dump_active ? "yes" : "no"));
pr_debug("Dump section sizes:\n");
pr_debug(" CPU state data size: %lx\n", fw_dump.cpu_state_data_size);
pr_debug(" HPTE region size : %lx\n", fw_dump.hpte_region_size);
pr_debug("Boot memory size : %lx\n", fw_dump.boot_memory_size);
}
static unsigned long init_fadump_mem_struct(struct fadump_mem_struct *fdm,
unsigned long addr)
{
if (!fdm)
return 0;
memset(fdm, 0, sizeof(struct fadump_mem_struct));
addr = addr & PAGE_MASK;
fdm->header.dump_format_version = 0x00000001;
fdm->header.dump_num_sections = 3;
fdm->header.dump_status_flag = 0;
fdm->header.offset_first_dump_section =
(u32)offsetof(struct fadump_mem_struct, cpu_state_data);
/*
* Fields for disk dump option.
* We are not using disk dump option, hence set these fields to 0.
*/
fdm->header.dd_block_size = 0;
fdm->header.dd_block_offset = 0;
fdm->header.dd_num_blocks = 0;
fdm->header.dd_offset_disk_path = 0;
/* set 0 to disable an automatic dump-reboot. */
fdm->header.max_time_auto = 0;
/* Kernel dump sections */
/* cpu state data section. */
fdm->cpu_state_data.request_flag = FADUMP_REQUEST_FLAG;
fdm->cpu_state_data.source_data_type = FADUMP_CPU_STATE_DATA;
fdm->cpu_state_data.source_address = 0;
fdm->cpu_state_data.source_len = fw_dump.cpu_state_data_size;
fdm->cpu_state_data.destination_address = addr;
addr += fw_dump.cpu_state_data_size;
/* hpte region section */
fdm->hpte_region.request_flag = FADUMP_REQUEST_FLAG;
fdm->hpte_region.source_data_type = FADUMP_HPTE_REGION;
fdm->hpte_region.source_address = 0;
fdm->hpte_region.source_len = fw_dump.hpte_region_size;
fdm->hpte_region.destination_address = addr;
addr += fw_dump.hpte_region_size;
/* RMA region section */
fdm->rmr_region.request_flag = FADUMP_REQUEST_FLAG;
fdm->rmr_region.source_data_type = FADUMP_REAL_MODE_REGION;
fdm->rmr_region.source_address = RMA_START;
fdm->rmr_region.source_len = fw_dump.boot_memory_size;
fdm->rmr_region.destination_address = addr;
addr += fw_dump.boot_memory_size;
return addr;
}
/**
* fadump_calculate_reserve_size(): reserve variable boot area 5% of System RAM
*
@ -166,7 +253,14 @@ int __init fadump_reserve_mem(void)
fw_dump.fadump_enabled = 0;
return 0;
}
/* Initialize boot memory size */
/*
* Initialize boot memory size
* If dump is active then we have already calculated the size during
* first kernel.
*/
if (fdm_active)
fw_dump.boot_memory_size = fdm_active->rmr_region.source_len;
else
fw_dump.boot_memory_size = fadump_calculate_reserve_size();
/*
@ -244,3 +338,258 @@ static int __init early_fadump_reserve_mem(char *p)
return 0;
}
early_param("fadump_reserve_mem", early_fadump_reserve_mem);
static void register_fw_dump(struct fadump_mem_struct *fdm)
{
int rc;
unsigned int wait_time;
pr_debug("Registering for firmware-assisted kernel dump...\n");
/* TODO: Add upper time limit for the delay */
do {
rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
FADUMP_REGISTER, fdm,
sizeof(struct fadump_mem_struct));
wait_time = rtas_busy_delay_time(rc);
if (wait_time)
mdelay(wait_time);
} while (wait_time);
switch (rc) {
case -1:
printk(KERN_ERR "Failed to register firmware-assisted kernel"
" dump. Hardware Error(%d).\n", rc);
break;
case -3:
printk(KERN_ERR "Failed to register firmware-assisted kernel"
" dump. Parameter Error(%d).\n", rc);
break;
case -9:
printk(KERN_ERR "firmware-assisted kernel dump is already "
" registered.");
fw_dump.dump_registered = 1;
break;
case 0:
printk(KERN_INFO "firmware-assisted kernel dump registration"
" is successful\n");
fw_dump.dump_registered = 1;
break;
}
}
static void register_fadump(void)
{
/*
* If no memory is reserved then we can not register for firmware-
* assisted dump.
*/
if (!fw_dump.reserve_dump_area_size)
return;
/* register the future kernel dump with firmware. */
register_fw_dump(&fdm);
}
static int fadump_unregister_dump(struct fadump_mem_struct *fdm)
{
int rc = 0;
unsigned int wait_time;
pr_debug("Un-register firmware-assisted dump\n");
/* TODO: Add upper time limit for the delay */
do {
rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
FADUMP_UNREGISTER, fdm,
sizeof(struct fadump_mem_struct));
wait_time = rtas_busy_delay_time(rc);
if (wait_time)
mdelay(wait_time);
} while (wait_time);
if (rc) {
printk(KERN_ERR "Failed to un-register firmware-assisted dump."
" unexpected error(%d).\n", rc);
return rc;
}
fw_dump.dump_registered = 0;
return 0;
}
static ssize_t fadump_enabled_show(struct kobject *kobj,
struct kobj_attribute *attr,
char *buf)
{
return sprintf(buf, "%d\n", fw_dump.fadump_enabled);
}
static ssize_t fadump_register_show(struct kobject *kobj,
struct kobj_attribute *attr,
char *buf)
{
return sprintf(buf, "%d\n", fw_dump.dump_registered);
}
static ssize_t fadump_register_store(struct kobject *kobj,
struct kobj_attribute *attr,
const char *buf, size_t count)
{
int ret = 0;
if (!fw_dump.fadump_enabled || fdm_active)
return -EPERM;
mutex_lock(&fadump_mutex);
switch (buf[0]) {
case '0':
if (fw_dump.dump_registered == 0) {
ret = -EINVAL;
goto unlock_out;
}
/* Un-register Firmware-assisted dump */
fadump_unregister_dump(&fdm);
break;
case '1':
if (fw_dump.dump_registered == 1) {
ret = -EINVAL;
goto unlock_out;
}
/* Register Firmware-assisted dump */
register_fadump();
break;
default:
ret = -EINVAL;
break;
}
unlock_out:
mutex_unlock(&fadump_mutex);
return ret < 0 ? ret : count;
}
static int fadump_region_show(struct seq_file *m, void *private)
{
const struct fadump_mem_struct *fdm_ptr;
if (!fw_dump.fadump_enabled)
return 0;
if (fdm_active)
fdm_ptr = fdm_active;
else
fdm_ptr = &fdm;
seq_printf(m,
"CPU : [%#016llx-%#016llx] %#llx bytes, "
"Dumped: %#llx\n",
fdm_ptr->cpu_state_data.destination_address,
fdm_ptr->cpu_state_data.destination_address +
fdm_ptr->cpu_state_data.source_len - 1,
fdm_ptr->cpu_state_data.source_len,
fdm_ptr->cpu_state_data.bytes_dumped);
seq_printf(m,
"HPTE: [%#016llx-%#016llx] %#llx bytes, "
"Dumped: %#llx\n",
fdm_ptr->hpte_region.destination_address,
fdm_ptr->hpte_region.destination_address +
fdm_ptr->hpte_region.source_len - 1,
fdm_ptr->hpte_region.source_len,
fdm_ptr->hpte_region.bytes_dumped);
seq_printf(m,
"DUMP: [%#016llx-%#016llx] %#llx bytes, "
"Dumped: %#llx\n",
fdm_ptr->rmr_region.destination_address,
fdm_ptr->rmr_region.destination_address +
fdm_ptr->rmr_region.source_len - 1,
fdm_ptr->rmr_region.source_len,
fdm_ptr->rmr_region.bytes_dumped);
if (!fdm_active ||
(fw_dump.reserve_dump_area_start ==
fdm_ptr->cpu_state_data.destination_address))
return 0;
/* Dump is active. Show reserved memory region. */
seq_printf(m,
" : [%#016llx-%#016llx] %#llx bytes, "
"Dumped: %#llx\n",
(unsigned long long)fw_dump.reserve_dump_area_start,
fdm_ptr->cpu_state_data.destination_address - 1,
fdm_ptr->cpu_state_data.destination_address -
fw_dump.reserve_dump_area_start,
fdm_ptr->cpu_state_data.destination_address -
fw_dump.reserve_dump_area_start);
return 0;
}
static struct kobj_attribute fadump_attr = __ATTR(fadump_enabled,
0444, fadump_enabled_show,
NULL);
static struct kobj_attribute fadump_register_attr = __ATTR(fadump_registered,
0644, fadump_register_show,
fadump_register_store);
static int fadump_region_open(struct inode *inode, struct file *file)
{
return single_open(file, fadump_region_show, inode->i_private);
}
static const struct file_operations fadump_region_fops = {
.open = fadump_region_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static void fadump_init_files(void)
{
struct dentry *debugfs_file;
int rc = 0;
rc = sysfs_create_file(kernel_kobj, &fadump_attr.attr);
if (rc)
printk(KERN_ERR "fadump: unable to create sysfs file"
" fadump_enabled (%d)\n", rc);
rc = sysfs_create_file(kernel_kobj, &fadump_register_attr.attr);
if (rc)
printk(KERN_ERR "fadump: unable to create sysfs file"
" fadump_registered (%d)\n", rc);
debugfs_file = debugfs_create_file("fadump_region", 0444,
powerpc_debugfs_root, NULL,
&fadump_region_fops);
if (!debugfs_file)
printk(KERN_ERR "fadump: unable to create debugfs file"
" fadump_region\n");
return;
}
/*
* Prepare for firmware-assisted dump.
*/
int __init setup_fadump(void)
{
if (!fw_dump.fadump_enabled)
return 0;
if (!fw_dump.fadump_supported) {
printk(KERN_ERR "Firmware-assisted dump is not supported on"
" this hardware\n");
return 0;
}
fadump_show_config();
/* Initialize the kernel dump memory structure for FAD registration. */
if (fw_dump.reserve_dump_area_size)
init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start);
fadump_init_files();
return 1;
}
subsys_initcall(setup_fadump);

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@ -39,6 +39,7 @@
#include <asm/pci-bridge.h>
#include <asm/machdep.h>
#include <asm/kdump.h>
#include <asm/fadump.h>
#define DBG(...)
@ -445,7 +446,12 @@ void iommu_unmap_sg(struct iommu_table *tbl, struct scatterlist *sglist,
static void iommu_table_clear(struct iommu_table *tbl)
{
if (!is_kdump_kernel()) {
/*
* In case of firmware assisted dump system goes through clean
* reboot process at the time of system crash. Hence it's safe to
* clear the TCE entries if firmware assisted dump is active.
*/
if (!is_kdump_kernel() || is_fadump_active()) {
/* Clear the table in case firmware left allocations in it */
ppc_md.tce_free(tbl, tbl->it_offset, tbl->it_size);
return;

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@ -55,6 +55,7 @@
#include <asm/spu.h>
#include <asm/udbg.h>
#include <asm/code-patching.h>
#include <asm/fadump.h>
#ifdef DEBUG
#define DBG(fmt...) udbg_printf(fmt)
@ -625,6 +626,16 @@ static void __init htab_initialize(void)
/* Using a hypervisor which owns the htab */
htab_address = NULL;
_SDR1 = 0;
#ifdef CONFIG_FA_DUMP
/*
* If firmware assisted dump is active firmware preserves
* the contents of htab along with entire partition memory.
* Clear the htab if firmware assisted dump is active so
* that we dont end up using old mappings.
*/
if (is_fadump_active() && ppc_md.hpte_clear_all)
ppc_md.hpte_clear_all();
#endif
} else {
/* Find storage for the HPT. Must be contiguous in
* the absolute address space. On cell we want it to be