linux-stable.git/drivers/acpi/sysfs.c, branch v4.9

ACPI / sysfs: Update sysfs signature handling code

2016-09-16T23:12:34+00:00

This patch cleans up sysfs table signature handling code:

 1. Convert the signature handling code to use the ACPICA APIs to
    benefit from the future improvements of the APIs.

 2. Add 'filename' attribute in order to handle both BE/LE name tags.

 3. Add instance check in order to avoid the possible buffer overflow
    related to the table file name.

Signed-off-by: Lv Zheng 
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki

ACPI / sysfs: Fix an issue for LoadTable opcode

2016-09-16T23:10:43+00:00

OEM tables can be installed via RSDT/XSDT, in this case, they have already
been created under /sys/firmware/acpi/tables.

For this kind of tables, normally LoadTable opcode will be executed to load
them. If LoadTable opcode is executed after acpi_sysfs_init(),
acpi_sysfs_table_handler() will be invoked, thus a redundant table file
will be created under /sys/firmware/acpi/tables/dynamic. Then running
"acpidump" on such platform results in an error, complaining blank empty
table (see Link 1 below).

The bug can be reproduced by customizing an OEM1 table, allowing it to be
overridden via 'table_sigs' (drivers/acpi/tables.c), adding the following
code to the customized DSDT to load it:

  Name (OEMH, Zero)
  Name (OEMF, One)
  If (LEqual (OEMF, One)) {
      Store (LoadTable ("OEM1", "Intel", "Test"), OEMH)
      Store (Zero, OEMF)
  }

In order to make sure that the OEM1 table is installed after
acpi_sysfs_init(), acpi_sysfs_init() can be moved before invoking
acpi_load_tables(). Then the following command execution result can be
seen:
 # acpidump > acpidump.txt
 Could not read table header: /sysfs/firmware/acpi/tables/dynamic/OEM12
 Could not get ACPI table at index 17, AE_BAD_HEADER

Link: https://bugzilla.kernel.org/show_bug.cgi?id=150841 # [1]
Link: https://github.com/acpica/acpica/commit/ed6a5fbc
Reported-by: Jason Voelz 
Reported-by: Francisco Leoner 
Signed-off-by: Lv Zheng 
Signed-off-by: Rafael J. Wysocki

ACPI / sysfs: Use new GPE masking mechanism in GPE interface

2016-08-17T00:10:44+00:00

Now GPE can be masked via the new acpi_mask_gpe() API and this patch
modifies /sys/firmware/acpi/interrupts/gpexx to use this new facility.

Writes "mask/unmask" to this file now invokes acpi_mask_gpe().

Reads from this file now returns new "EN/STS" when the corresponding GPE
hardware register's EN/STS bits are flagged, and new "masked/unmasked"
attribute to indicate the status of the masking mechanism.

Signed-off-by: Lv Zheng 
[ rjw: Subject ]
Signed-off-by: Rafael J. Wysocki

ACPI: add support for ACPI reconfiguration notifiers

2016-07-08T19:52:35+00:00

Add support for ACPI reconfiguration notifiers to allow subsystems
to react to changes in the ACPI tables that happen after the initial
enumeration. This is similar with the way dynamic device tree
notifications work.

The reconfigure notifications supported for now are device add and
device remove.

Since ACPICA allows only one table notification handler, this patch
makes the table notifier function generic and moves it out of the
sysfs specific code.

Signed-off-by: Octavian Purdila 
Reviewed-by: Mika Westerberg 
Signed-off-by: Rafael J. Wysocki

ACPI / sysfs: fix error code in get_status()

2016-05-05T13:28:58+00:00

The problem with ornamental, do-nothing gotos is that they lead to
"forgot to set the error code" bugs.  We should be returning -EINVAL
here but we don't.  It leads to an uninitalized variable in
counter_show():

    drivers/acpi/sysfs.c:603 counter_show()
    error: uninitialized symbol 'status'.

Fixes: 1c8fce27e275 (ACPI: introduce drivers/acpi/sysfs.c)
Signed-off-by: Dan Carpenter 
Signed-off-by: Rafael J. Wysocki

ACPI / sysfs: correctly check failing memory allocation

2015-10-26T03:57:27+00:00

Since kobject_create_and_add() can fail under memory pressure,
its return value needs to be checked against NULL before passing
it to sysfs_create_file().

Signed-off-by: Insu Yun 
[ rjw: Subject & changelog ]
Signed-off-by: Rafael J. Wysocki

ACPI / sysfs: Add support to allow leading "\" missing in trace_method_name.

2015-08-07T00:42:22+00:00

Since _SB.PCI0 can be used as relative path from root and can be easily
converted into internal trace_method_name format, we allow users to specify
trace_method_name using relative paths from root.
Note this is useful for grub2 for which users failed to pass "\" from the
grub configuration file.

Signed-off-by: Lv Zheng 
Signed-off-by: Rafael J. Wysocki

ACPI / sysfs: Update method tracing facility.

2015-08-07T00:42:21+00:00

This patch updates the method tracing facility as the acpi_debug_trace()
API has been updated to allow it to trace AML interpreter execution, the
meanings and the usages of the API parameters are changed due to the
updates.

The new API:
1. Uses ACPI_TRACE_ENABLED flag to indicate the enabling of the tracer;
2. Allows tracer still can be enabled when method name is not specified so
   that the AML interpreter execution can be traced without knowing the
   method name, which is useful for kernel boot tracing;
3. Supports arbitrary full path name, it doesn't need to be a name related
   to an entrance of acpi_evaluate_object().

Note that the sysfs parameters are also updated so that when reading the
attribute files, ACPICA internal settings are returned.

In order to make the sysfs parameters (acpi.trace_state) available during
boot, this patch adds code to bypass ACPICA semaphore/mutex invocations
when acpi mutex utilities haven't been initialized.

This patch doesn't update documentation of method tracing facility, it will
be updated by further patches.

Signed-off-by: Lv Zheng 
Signed-off-by: Rafael J. Wysocki

ACPI / sysfs: Add ACPI_LV_REPAIR debug level.

2015-08-07T00:42:21+00:00

This patch updates debug_level file, adding ACPI_LV_REPAIR.

Signed-off-by: Lv Zheng 
Signed-off-by: Rafael J. Wysocki

ACPI / sysfs: Treat the count field of counter_show() as unsigned

2015-03-10T00:03:30+00:00

The count field is an unsigned 32bit value, and the
counter_show() function should also treat it as a unsigned
value.

Otherwise the counter may show negative number as we found on a
machine:
...
gpe23:        0   invalid
gpe24: -2071733   enabled
gpe25:        0   invalid
...
gpe_all: -2070980
sci: -2070949

Signed-off-by: Nan Li 
Signed-off-by: Lee, Chun-Yi 
Signed-off-by: Rafael J. Wysocki