linux-stable.git/drivers/acpi, branch v4.7.3

ACPI / drivers: replace acpi_probe_lock spinlock with mutex

2016-09-07T06:34:55+00:00

commit 5331d9cab32ef640b4cd38a43b0858874fbb7168 upstream.

Commit e647b532275b ("ACPI: Add early device probing infrastructure")
introduced code that allows inserting driver specific
struct acpi_probe_entry probe entries into ACPI linker sections
(one per-subsystem, eg irqchip, clocksource) that are then walked
to retrieve the data and function hooks required to probe the
respective kernel components.

Probing for all entries in a section is triggered through
the __acpi_probe_device_table() function, that in turn, according
to the table ID a given probe entry reports parses the table
with the function retrieved from the respective section structures
(ie struct acpi_probe_entry). Owing to the current ACPI table
parsing implementation, the __acpi_probe_device_table() function
has to share global variables with the acpi_match_madt() function, so
in order to guarantee mutual exclusion locking is required
between the two functions.

Current kernel code implements the locking through the acpi_probe_lock
spinlock; this has the side effect of requiring all code called
within the lock (ie struct acpi_probe_entry.probe_{table/subtbl} hooks)
not to sleep.

However, kernel subsystems that make use of the early probing
infrastructure are relying on kernel APIs that may sleep (eg
irq_domain_alloc_fwnode(), among others) in the function calls
pointed at by struct acpi_probe_entry.{probe_table/subtbl} entries
(eg gic_v2_acpi_init()), which is a bug.

Since __acpi_probe_device_table() is called from context
that is allowed to sleep the acpi_probe_lock spinlock can be replaced
with a mutex; this fixes the issue whilst still guaranteeing
mutual exclusion.

Signed-off-by: Lorenzo Pieralisi 
Fixes: e647b532275b (ACPI: Add early device probing infrastructure)
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

ACPI / CPPC: Prevent cpc_desc_ptr points to the invalid data

2016-09-07T06:34:44+00:00

commit 2324d15447a9db168b1f85e3feac635b1ff8edb8 upstream.

When CPPC fails to request a PCC channel, the CPC data is freed
and cpc_desc_ptr points to the invalid data.

Avoid this issue by moving the cpc_desc_ptr assignment after the PCC
channel request.

Signed-off-by: Hoan Tran 
Acked-by: Ashwin Chaugule 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

ACPI: CPPC: Return error if _CPC is invalid on a CPU

2016-09-07T06:34:44+00:00

commit 8343c40d3de32ebfe8f48b043964e4ba0e7701f7 upstream.

Based on 8.4.7.1 section of ACPI 6.1 specification, if the platform
supports CPPC, the _CPC object must exist under all processor objects.
If cpc_desc_ptr pointer is invalid on any CPUs, acpi_get_psd_map()
should return error and CPPC cpufreq driver can not be registered.

Signed-off-by: Hoan Tran 
Reviewed-by: Prashanth Prakash 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

libnvdimm, nd_blk: mask off reserved status bits

2016-09-07T06:34:44+00:00

commit 68202c9f0ad6e16ee806fbadbc5838d55fe5aa5c upstream.

The "NVDIMM Block Window Driver Writer's Guide":

    http://pmem.io/documents/NVDIMM_DriverWritersGuide-July-2016.pdf

...defines the layout of the block window status register.  For the July
2016 version of the spec linked to above, this happens in Figure 4 on
page 26.

The only bits defined in this spec are bits 31, 5, 4, 2, 1 and 0.  The
rest of the bits in the status register are reserved, and there is a
warning following the diagram that says:

    Note: The driver cannot assume the value of the RESERVED bits in the
    status register are zero. These reserved bits need to be masked off, and
    the driver must avoid checking the state of those bits.

This change ensures that for hardware implementations that set these
reserved bits in the status register, the driver won't incorrectly fail the
block I/Os.

Reviewed-by: Lee, Chun-Yi 
Signed-off-by: Ross Zwisler 
Signed-off-by: Dan Williams 
Signed-off-by: Greg Kroah-Hartman

ACPI / EC: Work around method reentrancy limit in ACPICA for _Qxx

2016-08-20T16:11:04+00:00

commit e1191bd4f62d9086a1a47adc286e7fcffc1fa55c upstream.

A regression is caused by the following commit:

  Commit: 02b771b64b73226052d6e731a0987db3b47281e9
  Subject: ACPI / EC: Fix an issue caused by the serialized _Qxx evaluations

In this commit, using system workqueue causes that the maximum parallel
executions of _Qxx can exceed 255. This violates the method reentrancy
limit in ACPICA and generates the following error log:

  ACPI Error: Method reached maximum reentrancy limit (255) (20150818/dsmethod-341)

This patch creates a seperate workqueue and limits the number of parallel
_Qxx evaluations down to a configurable value (can be tuned against number
of online CPUs).

Since EC events are handled after driver probe, we can create the workqueue
in acpi_ec_init().

Fixes: 02b771b64b73 (ACPI / EC: Fix an issue caused by the serialized _Qxx evaluations)
Link: https://bugzilla.kernel.org/show_bug.cgi?id=135691
Reported-and-tested-by: Helen Buus 
Signed-off-by: Lv Zheng 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

Merge branch 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

2016-07-23T03:07:37+00:00

Pull libnvdimm fix from Dan Williams:
 "This contains a regression fix for a problem that was introduced in
  v4.7-rc6.

  In 4.7-rc1 we introduced auto-probing for the ACPI DSM (device-
  specific-method) format that the platform firmware implements for
  nvdimm devices.  We initially fixed a regression in probing the QEMU
  DSM implementation by making acpi_check_dsm() tolerant of the way QEMU
  reports the "0 DSMs supported" condition.

  However, that broke HPE platforms since that tolerance caused the
  driver to mistakenly match the 1-zero-byte response those platforms
  give to "unknown" commands.  Instead, we simply make the driver
  tolerant of not finding any supported DSMs.  This has been tested to
  work with both QEMU and HPE platforms.

  This commit has appeared in a -next release with no reported issues"

* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  nfit: make DIMM DSMs optional

nfit: make DIMM DSMs optional

2016-07-19T19:32:39+00:00

Commit 4995734e973a "acpi, nfit: fix acpi_check_dsm() vs zero functions
implemented" attempted to fix a QEMU regression by supporting its usage
of a zero-mask as a valid response to a DSM-family probe request.
However, this behavior breaks HP platforms that return a zero-mask by
default causing the probe to misidentify the DSM-family.

Instead, the QEMU regression can be fixed by simply not requiring the DSM
family to be identified.

This effectively reverts commit 4995734e973a, and removes the DSM
requirement from the init path.

Cc: "Rafael J. Wysocki" 
Cc: Xiao Guangrong 
Cc: Linda Knippers 
Fixes: 4995734e973a ("acpi, nfit: fix acpi_check_dsm() vs zero functions implemented")
Reported-by: Jerry Hoemann 
Tested-by: Jerry Hoemann 
Signed-off-by: Dan Williams

Merge branches 'acpica-fixes' and 'acpi-ec-fixes'

2016-07-12T20:03:14+00:00

* acpica-fixes:
  Revert "ACPI 2.0 / AML: Improve module level execution by moving the If/Else/While execution to per-table basis"
  Revert "ACPICA: Namespace: Fix deadlock triggered by MLC support in dynamic table loading"
  Revert "ACPICA: Namespace: Fix namespace/interpreter lock ordering"

* acpi-ec-fixes:
  ACPI / EC: Fix code ordering issue in ec_remove_handlers()

Revert "ACPICA: Namespace: Fix deadlock triggered by MLC support in dynamic table loading"

2016-07-11T14:18:18+00:00

Revert commit 2f38b1b16d92 (ACPICA: Namespace: Fix deadlock triggered by
MLC support in dynamic table loading) that attempted to fix a deadlock
issue introduced by a previous commit, but it led to a lock ordering
inconsistency that caused further problems to appear.

Fixes: 2f38b1b16d92 (ACPICA: Namespace: Fix deadlock triggered by MLC support in dynamic table loading)
Signed-off-by: Rafael J. Wysocki

Revert "ACPICA: Namespace: Fix namespace/interpreter lock ordering"

2016-07-11T14:17:37+00:00

Revert commit 45209046c47b (ACPICA: Namespace: Fix namespace/interpreter
lock ordering) that renders Dell Precision 5510 with the latest (1.2.10)
BIOS applied unable to boot.

Fixes: 45209046c47b (ACPICA: Namespace: Fix namespace/interpreter lock ordering)
Link: https://bugzilla.kernel.org/show_bug.cgi?id=121701
Reported-by: Greg White 
Signed-off-by: Rafael J. Wysocki