There have been multiple reports of the following error message:
[ 0.068293] Error parsing PCC subspaces from PCCT
This error message is not correct. In multiple cases examined, the PCCT
(Platform Communications Channel Table) concerned is actually properly
constructed; the problem is that acpi_pcc_probe() which reads the PCCT
is making the assumption that the only valid PCCT is one that contains
subtables of one of two types: ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE or
ACPI_PCCT_TYPE_HW_REDUCED_TYPE2. The number of subtables of these
types are counted and as long as there is at least one of the desired
types, the acpi_pcc_probe() succeeds. When no subtables of these types
are found, regardless of whether or not any other subtable types are
present, the error mentioned above is reported.
In the cases reported to me personally, the PCCT contains exactly one
subtable of type ACPI_PCCT_TYPE_GENERIC_SUBSPACE. The function
acpi_pcc_probe() does not count it as a valid subtable, so believes
there to be no valid subtables, and hence outputs the error message.
An example of the PCCT being reported as erroneous yet perfectly fine
is the following:
Signature : "PCCT"
Table Length : 0000006E
Revision : 05
Checksum : A9
Oem ID : "XXXXXX"
Oem Table ID : "XXXXX "
Oem Revision : 00002280
Asl Compiler ID : "XXXX"
Asl Compiler Revision : 00000002
Flags (decoded below) : 00000001
Platform : 1
Reserved : 0000000000000000
Subtable Type : 00 [Generic Communications Subspace]
Length : 3E
Reserved : 000000000000
Base Address : 00000000DCE43018
Address Length : 0000000000001000
Doorbell Register : [Generic Address Structure]
Space ID : 01 [SystemIO]
Bit Width : 08
Bit Offset : 00
Encoded Access Width : 01 [Byte Access:8]
Address : 0000000000001842
Preserve Mask : 00000000000000FD
Write Mask : 0000000000000002
Command Latency : 00001388
Maximum Access Rate : 00000000
Minimum Turnaround Time : 0000
To fix this, we count up all of the possible subtable types for the
PCCT, and only report an error when there are none (which could mean
either no subtables, or no valid subtables), or there are too many.
We also change the logic so that if there is a valid subtable, we
do try to initialize it per the PCCT subtable contents. This is a
change in functionality; previously, the probe would have returned
right after the error message and would not have tried to use any
other subtable definition.
Tested on my personal laptop which showed the error previously; the
error message no longer appears and the laptop appears to operate
normally.
Signed-off-by: Al Stone <ahs3@redhat.com>
Reviewed-by: Prashanth Prakash <pprakash@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
- Core: Prefer ACK method over POLL, if both supported
- Test: use flag instead of special character
- FlexRM: Usual driver internal minor churn
- Omap: fix error path
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Merge tag 'mailbox-v4.15' of git://git.linaro.org/landing-teams/working/fujitsu/integration
Pull mailbox updates from Jassi Brar:
"Change to POLL api and fixes for FlexRM and OMAP driver.
Summary:
- Core: Prefer ACK method over POLL, if both supported
- Test: use flag instead of special character
- FlexRM: Usual driver internal minor churn
- Omap: fix error path"
* tag 'mailbox-v4.15' of git://git.linaro.org/landing-teams/working/fujitsu/integration:
mailbox/omap: unregister mbox class
mailbox: mailbox-test: don't rely on rx_buffer content to signal data ready
mailbox: reset txdone_method TXDONE_BY_POLL if client knows_txdone
mailbox: Build Broadcom FlexRM driver as loadable module for iProc SOCs
mailbox: bcm-flexrm-mailbox: Use common GPL comment header
mailbox: bcm-flexrm-mailbox: add depends on ARCH_BCM_IPROC
mailbox: bcm-flexrm-mailbox: Print ring number in errors and warnings
mailbox: bcm-flexrm-mailbox: Fix FlexRM ring flush sequence
Currently the mailbox framework sets txdone_method to TXDONE_BY_POLL if
the controller sets txdone_by_poll. However some clients can have a
mechanism to do TXDONE_BY_ACK which they can specify by knows_txdone.
However, we endup setting both TXDONE_BY_POLL and TXDONE_BY_ACK in that
case. In such scenario, we may end up with below warnings as the tx
ticker is run both by mailbox framework and the client.
WARNING: CPU: 1 PID: 0 at kernel/time/hrtimer.c:805 hrtimer_forward+0x88/0xd8
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.12.0-rc5 #242
Hardware name: ARM LTD ARM Juno Development Platform
task: ffff8009768ca700 task.stack: ffff8009768f8000
PC is at hrtimer_forward+0x88/0xd8
LR is at txdone_hrtimer+0xd4/0xf8
Call trace:
hrtimer_forward+0x88/0xd8
__hrtimer_run_queues+0xe4/0x158
hrtimer_interrupt+0xa4/0x220
arch_timer_handler_phys+0x30/0x40
handle_percpu_devid_irq+0x78/0x130
generic_handle_irq+0x24/0x38
__handle_domain_irq+0x5c/0xb8
gic_handle_irq+0x54/0xa8
This patch fixes the issue by resetting TXDONE_BY_POLL if client has set
knows_txdone.
Cc: Alexey Klimov <alexey.klimov@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
Move the MAX_PCC_SUBSPACES definition to acpi/pcc.h file in
preparation to add subspace ID support for cppc_acpi driver.
Signed-off-by: George Cherian <george.cherian@cavium.com>
Reviewed-by: Prashanth Prakash <pprakash@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
When booting on an ACPI enabled system that does not provide the
Platform Communications Channel Table (PCCT), the pcc mailbox driver
prints -
[ 0.484261] PCCT header not found.
during probe before returning -ENODEV.
This message clutters the bootlog and doesn't provide any useful
information. Drop this message.
Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Acked-by: Alexey Klimov <alexey.klimov@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPICA commit e7b817e3c405a4fb9ae9ee7ae4992b8c1f20d284
Extended PCC Subspaces (types 3 and 4)
Link: https://github.com/acpica/acpica/commit/e7b817e3
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* acpica:
ACPI / osl: Remove deprecated acpi_get_table_with_size()/early_acpi_os_unmap_memory()
ACPI / osl: Remove acpi_get_table_with_size()/early_acpi_os_unmap_memory() users
ACPICA: Tables: Allow FADT to be customized with virtual address
ACPICA: Tables: Back port acpi_get_table_with_size() and early_acpi_os_unmap_memory() from Linux kernel
* acpi-scan:
ACPI: do not warn if _BQC does not exist
This patch removes the users of the deprectated APIs:
acpi_get_table_with_size()
early_acpi_os_unmap_memory()
The following APIs should be used instead of:
acpi_get_table()
acpi_put_table()
The deprecated APIs are invented to be a replacement of acpi_get_table()
during the early stage so that the early mapped pointer will not be stored
in ACPICA core and thus the late stage acpi_get_table() won't return a
wrong pointer. The mapping size is returned just because it is required by
early_acpi_os_unmap_memory() to unmap the pointer during early stage.
But as the mapping size equals to the acpi_table_header.length
(see acpi_tb_init_table_descriptor() and acpi_tb_validate_table()), when
such a convenient result is returned, driver code will start to use it
instead of accessing acpi_table_header to obtain the length.
Thus this patch cleans up the drivers by replacing returned table size with
acpi_table_header.length, and should be a no-op.
Reported-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPI 6.1 has a PCC HW-Reduced Communication Subspace type 2 intended for
use on HW-Reduce ACPI Platform, which requires read-modify-write sequence
to acknowledge doorbell interrupt. This patch provides the implementation
for the Communication Subspace Type 2.
Signed-off-by: Hoan Tran <hotran@apm.com>
Reviewed-by: Prashanth Prakash <pprakash@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* pm-cpufreq:
cpufreq: dt: Drop stale comment
cpufreq: intel_pstate: Documenation for structures
cpufreq: intel_pstate: fix inconsistency in setting policy limits
intel_pstate: Avoid extra invocation of intel_pstate_sample()
intel_pstate: Do not set utilization update hook too early
* pm-cpuidle:
intel_idle: Add KBL support
intel_idle: Add SKX support
intel_idle: Clean up all registered devices on exit.
intel_idle: Propagate hot plug errors.
intel_idle: Don't overreact to a cpuidle registration failure.
intel_idle: Setup the timer broadcast only on successful driver load.
intel_idle: Avoid a double free of the per-CPU data.
intel_idle: Fix dangling registration on error path.
intel_idle: Fix deallocation order on the driver exit path.
intel_idle: Remove redundant initialization calls.
intel_idle: Fix a helper function's return value.
intel_idle: remove useless return from void function.
* acpi-cppc:
mailbox: pcc: Don't access an unmapped memory address space
The acpi_pcc_probe() may end up accessing memory outside of the PCCT
table space causing the kernel panic(). Increment the pcct_entry
pointer after parsing 'HW-reduced Communications Subspace' to fix
the problem. This change also enables the parsing of subtable at
index 0.
Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org>
Acked-by: Ashwin Chaugule <ashwin.chaugule@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* acpi-processor:
ACPI / sleep: move acpi_processor_sleep to sleep.c
ACPI / processor : add support for ACPI0010 processor container
ACPI / processor_idle: replace PREFIX with pr_fmt
* acpi-cppc:
ACPI / CPPC: use MRTT/MPAR to decide if/when a req can be sent
ACPI / CPPC: replace writeX/readX to PCC with relaxed version
mailbox: pcc: optimized pcc_send_data
ACPI / CPPC: optimized cpc_read and cpc_write
ACPI / CPPC: Optimize PCC Read Write operations
pcc_send_data() can be invoked during the execution of performance
critical code as in cppc_cpufreq driver. With acpi_* APIs, the
doorbell register accessed in pcc_send_data() if present in system
memory will be searched (in cached virt to phys addr mapping),
mapped, read/written and then unmapped. These operations take
significant amount of time.
This patch maps the performance critical doorbell register
during init and then reads/writes to it directly using the
mapped virtual address. This patch + similar changes to CPPC
acpi driver reduce the time per freq. transition from around
200us to about 20us for the CPPC cpufreq driver
Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org>
Acked-by: Ashwin Chaugule <ashwin.chaugule@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch fixes the calculation of pcc_chan for non-zero id.
After the compiler ignores the (unsigned long) cast the
pcc_mbox_channels pointer is type-cast and then the type-cast
offset is added which results in address outside of the range
leading to the kernel crashing.
We might add braces and make it:
pcc_chan = (struct mbox_chan *)
((unsigned long) pcc_mbox_channels +
(id * sizeof(*pcc_chan)));
but let's go with array approach here and use id as index.
Tested on Juno board.
Signed-off-by: Alexey Klimov <alexey.klimov@arm.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Ashwin Chaugule <ashwin.chaugule@linaro.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
get_pcc_channel() does not return NULL on error it returns the error code
in ERR_PTR, but we have been checking it for NULL.
Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
This change initializes the PCC Mailbox earlier than
the ACPI processor driver. This enables drivers introduced
in follow up patches (e.g. CPPC) to be probed via the ACPI
processor driver interface. The CPPC probe requires the PCC
channel to be initialized for it to query each CPUs performance
capabilities.
Signed-off-by: Ashwin Chaugule <ashwin.chaugule@linaro.org>
Reviewed-by: Al Stone <al.stone@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The mailbox controller's channel ops ought to be read-only. Update
all the mailbox drivers to make their mbox_chan_ops const as well.
Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Cc: Ashwin Chaugule <ashwin.chaugule@linaro.org>
Cc: Ley Foon Tan <lftan@altera.com>
Acked-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
Previously the PCC driver depended on the client
side to map the communication space base address. This region
was was then used in the PCC driver and the client side.
The client side used this region to read and write its data
and the PCC driver used it to only write the PCC command.
Removing this split simplifies the PCC driver a lot. This patch
moves all communication region read/writes to the client side.
The PCC clients can now drive the PCC mailbox controller via the
mbox_client_txdone() method.
Signed-off-by: Ashwin Chaugule <ashwin.chaugule@linaro.org>
Pull mailbox framework updates from Jassi Brar.
* 'mailbox-devel' of git://git.linaro.org/landing-teams/working/fujitsu/integration:
mailbox: Add Altera mailbox driver
mailbox: check for bit set before polling
Mailbox: Fix return value check in pcc_init()
In case of error, the function platform_create_bundle() returns
ERR_PTR() and never returns NULL. The NULL test in the return value
check should be replaced with IS_ERR().
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
pcc_init() uses pr_err() to print two messages that are really debug
and not interesting to users. Replace those pr_err() with pr_debug().
Reported-by: Cristian <caravena@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPI 5.0+ spec defines a generic mode of communication
between the OS and a platform such as the BMC. This medium
(PCC) is typically used by CPPC (ACPI CPU Performance management),
RAS (ACPI reliability protocol) and MPST (ACPI Memory power
states).
This patch adds PCC support as a Mailbox Controller. As of
ACPI v5.1 there is no provision for clients to lookup mailbox
controllers in a way that Linux expects. e.g. in DT the clients
can list the mailboxes they can associate with in the DT binding
and then provide a unique index to lookup a channel within a mailbox.
Since the ACPI spec doesn't have anything similar, we introduce a
mailbox controller specific API so that when the client calls it,
we know to lookup in the context of a specific controller. This
also helps in keeping a consistent interface across DT and ACPI
for such drivers.
This patch implements basic PCC support using the ACPI v5.1
structures. IRQ mode support will be provided as follow up patches.
Signed-off-by: Ashwin Chaugule <ashwin.chaugule@linaro.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>