<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/drivers/acpi/cppc_acpi.c, branch v6.6-rc3</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>ACPI: CPPC: Add auto select register read/write support</title>
<updated>2023-03-17T18:06:23+00:00</updated>
<author>
<name>Wyes Karny</name>
<email>wyes.karny@amd.com</email>
</author>
<published>2023-03-07T11:27:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=c984f5d5d45bd5f80d6a9d8541e809300c963aca'/>
<id>c984f5d5d45bd5f80d6a9d8541e809300c963aca</id>
<content type='text'>
For some AMD shared memory based systems, the autonomous selection bit
needed to be set explicitly. Add autonomous selection register related
APIs to acpi driver, which amd_pstate driver uses later.

Acked-by: Huang Rui &lt;ray.huang@amd.com&gt;
Reviewed-by: Mario Limonciello &lt;mario.limonciello@amd.com&gt;
Tested-by: Oleksandr Natalenko &lt;oleksandr@natalenko.name&gt;
Signed-off-by: Wyes Karny &lt;wyes.karny@amd.com&gt;
[ rjw: Fixed up kerneldoc comments, white space adjustment, subject edits ]
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
For some AMD shared memory based systems, the autonomous selection bit
needed to be set explicitly. Add autonomous selection register related
APIs to acpi driver, which amd_pstate driver uses later.

Acked-by: Huang Rui &lt;ray.huang@amd.com&gt;
Reviewed-by: Mario Limonciello &lt;mario.limonciello@amd.com&gt;
Tested-by: Oleksandr Natalenko &lt;oleksandr@natalenko.name&gt;
Signed-off-by: Wyes Karny &lt;wyes.karny@amd.com&gt;
[ rjw: Fixed up kerneldoc comments, white space adjustment, subject edits ]
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: CPPC: Add min and max perf register writing support</title>
<updated>2023-03-17T18:06:23+00:00</updated>
<author>
<name>Wyes Karny</name>
<email>wyes.karny@amd.com</email>
</author>
<published>2023-03-07T11:27:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=76531df5e13b5b997a17940d6980a168c616e962'/>
<id>76531df5e13b5b997a17940d6980a168c616e962</id>
<content type='text'>
Currently writing of min and max perf register is deferred in
cppc_set_perf function. In CPPC guided mode, these registers needed to
be written to guide the platform about min and max perf levels. Add this support
to make guided mode work properly on AMD shared memory systems.

Acked-by: Huang Rui &lt;ray.huang@amd.com&gt;
Reviewed-by: Mario Limonciello &lt;mario.limonciello@amd.com&gt;
Tested-by: Oleksandr Natalenko &lt;oleksandr@natalenko.name&gt;
Signed-off-by: Wyes Karny &lt;wyes.karny@amd.com&gt;
[ rjw: Fixed up a multiline comment, subject edits ]
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Currently writing of min and max perf register is deferred in
cppc_set_perf function. In CPPC guided mode, these registers needed to
be written to guide the platform about min and max perf levels. Add this support
to make guided mode work properly on AMD shared memory systems.

Acked-by: Huang Rui &lt;ray.huang@amd.com&gt;
Reviewed-by: Mario Limonciello &lt;mario.limonciello@amd.com&gt;
Tested-by: Oleksandr Natalenko &lt;oleksandr@natalenko.name&gt;
Signed-off-by: Wyes Karny &lt;wyes.karny@amd.com&gt;
[ rjw: Fixed up a multiline comment, subject edits ]
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'acpi-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm</title>
<updated>2023-02-21T20:23:24+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-02-21T20:23:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=88af9b164c7a25a71b1a1a699872b869e2e84c77'/>
<id>88af9b164c7a25a71b1a1a699872b869e2e84c77</id>
<content type='text'>
Pull ACPI updates from Rafael Wysocki:
 "These fix a frequency limit issue in the ACPI processor performance
  library code, fix a few issues in the ACPICA code, improve Crystal
  Cove support in the ACPI PMIC driver, fix string handling in the ACPI
  battery driver, add IRQ override quirks for a few machines more, fix
  other assorted problems and clean up code and documentation.

  Specifics:

   - Drop port I/O validation for some regions to avoid AML failures due
     to rejections of legitimate port I/O writes (Mario Limonciello)

   - Constify acpi_get_handle() pathname argument to allow its callers
     to pass const pathnames to it (Sakari Ailus)

   - Prevent acpi_ns_simple_repair() from crashing in some cases when
     AE_AML_NO_RETURN_VALUE should be returned (Daniil Tatianin)

   - Fix typo in CDAT DSMAS struct definition (Lukas Wunner)

   - Drop an unnecessary (void *) conversion from the ACPI processor
     driver (Zhou jie)

   - Modify the ACPI processor performance library code to use the "no
     limit" frequency QoS as appropriate and adjust the intel_pstate
     driver accordingly (Rafael Wysocki)

   - Add support for NBFT to the ACPI table parser (Stuart Hayes)

   - Introduce list of known non-PNP devices to avoid enumerating some
     of them as PNP devices (Rafael Wysocki)

   - Add x86 ACPI paths to the ACPI entry in MAINTAINERS to allow
     scripts to report the actual maintainers information (Rafael
     Wysocki)

   - Add two more entries to the ACPI IRQ override quirk list (Adam
     Niederer, Werner Sembach)

   - Add a pmic_i2c_address entry for Intel Bay Trail Crystal Cove to
     allow intel_soc_pmic_exec_mipi_pmic_seq_element() to be used with
     the Bay Trail Crystal Cove PMIC OpRegion driver (Hans de Goede)

   - Add comments with DSDT power OpRegion field names to the ACPI PMIC
     driver (Hans de Goede)

   - Fix string termination handling in the ACPI battery driver (Armin
     Wolf)

   - Limit error type to 32-bit width in the ACPI APEI error injection
     code (Shuai Xue)

   - Fix Lenovo Ideapad Z570 DMI match in the ACPI backlight driver
     (Hans de Goede)

   - Silence missing prototype warnings in some places in the
     ACPI-related code (Ammar Faizi)

   - Make kobj_type structures used in the ACPI code constant (Thomas
     Weißschuh)

   - Correct spelling in firmware-guide/ACPI (Randy Dunlap)

   - Clarify the meaning of Explicit and Implicit in the _DSD GPIO
     properties documentation (Andy Shevchenko)

   - Fix some kernel-doc comments in the ACPI CPPC library code (Yang
     Li)"

* tag 'acpi-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (25 commits)
  ACPI: make kobj_type structures constant
  Documentation: firmware-guide: gpio-properties: Clarify Explicit and Implicit
  ACPICA: Fix typo in CDAT DSMAS struct definition
  ACPI: resource: Do IRQ override on all TongFang GMxRGxx
  ACPI: resource: Add IRQ overrides for MAINGEAR Vector Pro 2 models
  ACPI: CPPC: Fix some kernel-doc comments
  ACPI: video: Fix Lenovo Ideapad Z570 DMI match
  Documentation: firmware-guide/ACPI: correct spelling
  ACPI: PMIC: Add comments with DSDT power opregion field names
  ACPI: battery: Increase maximum string length
  ACPI: battery: Fix buffer overread if not NUL-terminated
  ACPI: APEI: EINJ: Limit error type to 32-bit width
  MAINTAINERS: Add x86 ACPI paths to the ACPI entry
  ACPI: battery: Fix missing NUL-termination with large strings
  ACPI: PNP: Introduce list of known non-PNP devices
  ACPICA: nsrepair: handle cases without a return value correctly
  ACPI: Silence missing prototype warnings
  cpufreq: intel_pstate: Drop ACPI _PSS states table patching
  ACPI: processor: perflib: Avoid updating frequency QoS unnecessarily
  ACPI: processor: perflib: Use the "no limit" frequency QoS
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull ACPI updates from Rafael Wysocki:
 "These fix a frequency limit issue in the ACPI processor performance
  library code, fix a few issues in the ACPICA code, improve Crystal
  Cove support in the ACPI PMIC driver, fix string handling in the ACPI
  battery driver, add IRQ override quirks for a few machines more, fix
  other assorted problems and clean up code and documentation.

  Specifics:

   - Drop port I/O validation for some regions to avoid AML failures due
     to rejections of legitimate port I/O writes (Mario Limonciello)

   - Constify acpi_get_handle() pathname argument to allow its callers
     to pass const pathnames to it (Sakari Ailus)

   - Prevent acpi_ns_simple_repair() from crashing in some cases when
     AE_AML_NO_RETURN_VALUE should be returned (Daniil Tatianin)

   - Fix typo in CDAT DSMAS struct definition (Lukas Wunner)

   - Drop an unnecessary (void *) conversion from the ACPI processor
     driver (Zhou jie)

   - Modify the ACPI processor performance library code to use the "no
     limit" frequency QoS as appropriate and adjust the intel_pstate
     driver accordingly (Rafael Wysocki)

   - Add support for NBFT to the ACPI table parser (Stuart Hayes)

   - Introduce list of known non-PNP devices to avoid enumerating some
     of them as PNP devices (Rafael Wysocki)

   - Add x86 ACPI paths to the ACPI entry in MAINTAINERS to allow
     scripts to report the actual maintainers information (Rafael
     Wysocki)

   - Add two more entries to the ACPI IRQ override quirk list (Adam
     Niederer, Werner Sembach)

   - Add a pmic_i2c_address entry for Intel Bay Trail Crystal Cove to
     allow intel_soc_pmic_exec_mipi_pmic_seq_element() to be used with
     the Bay Trail Crystal Cove PMIC OpRegion driver (Hans de Goede)

   - Add comments with DSDT power OpRegion field names to the ACPI PMIC
     driver (Hans de Goede)

   - Fix string termination handling in the ACPI battery driver (Armin
     Wolf)

   - Limit error type to 32-bit width in the ACPI APEI error injection
     code (Shuai Xue)

   - Fix Lenovo Ideapad Z570 DMI match in the ACPI backlight driver
     (Hans de Goede)

   - Silence missing prototype warnings in some places in the
     ACPI-related code (Ammar Faizi)

   - Make kobj_type structures used in the ACPI code constant (Thomas
     Weißschuh)

   - Correct spelling in firmware-guide/ACPI (Randy Dunlap)

   - Clarify the meaning of Explicit and Implicit in the _DSD GPIO
     properties documentation (Andy Shevchenko)

   - Fix some kernel-doc comments in the ACPI CPPC library code (Yang
     Li)"

* tag 'acpi-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (25 commits)
  ACPI: make kobj_type structures constant
  Documentation: firmware-guide: gpio-properties: Clarify Explicit and Implicit
  ACPICA: Fix typo in CDAT DSMAS struct definition
  ACPI: resource: Do IRQ override on all TongFang GMxRGxx
  ACPI: resource: Add IRQ overrides for MAINGEAR Vector Pro 2 models
  ACPI: CPPC: Fix some kernel-doc comments
  ACPI: video: Fix Lenovo Ideapad Z570 DMI match
  Documentation: firmware-guide/ACPI: correct spelling
  ACPI: PMIC: Add comments with DSDT power opregion field names
  ACPI: battery: Increase maximum string length
  ACPI: battery: Fix buffer overread if not NUL-terminated
  ACPI: APEI: EINJ: Limit error type to 32-bit width
  MAINTAINERS: Add x86 ACPI paths to the ACPI entry
  ACPI: battery: Fix missing NUL-termination with large strings
  ACPI: PNP: Introduce list of known non-PNP devices
  ACPICA: nsrepair: handle cases without a return value correctly
  ACPI: Silence missing prototype warnings
  cpufreq: intel_pstate: Drop ACPI _PSS states table patching
  ACPI: processor: perflib: Avoid updating frequency QoS unnecessarily
  ACPI: processor: perflib: Use the "no limit" frequency QoS
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branches 'acpi-video', 'acpi-misc' and 'acpi-docs'</title>
<updated>2023-02-15T14:42:59+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2023-02-15T14:42:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=f32309c4d08dbac74d3253ac8310bfcad4e21606'/>
<id>f32309c4d08dbac74d3253ac8310bfcad4e21606</id>
<content type='text'>
Merge ACPI backlight driver changes, miscellaneous ACPI-related changes
and ACPI-related documentation updates for 6.3-rc1:

 - Fix Lenovo Ideapad Z570 DMI match in the ACPI backlight driver (Hans
   de Goede).

 - Silence missing prototype warnings in some places in the ACPI-related
   code (Ammar Faizi).

 - Make kobj_type structures used in the ACPI code constant (Thomas
   Weißschuh).

 - Correct spelling in firmware-guide/ACPI (Randy Dunlap).

 - Clarify the meaning of Explicit and Implicit in the _DSD GPIO
   properties documentation (Andy Shevchenko).

* acpi-video:
  ACPI: video: Fix Lenovo Ideapad Z570 DMI match

* acpi-misc:
  ACPI: make kobj_type structures constant
  ACPI: Silence missing prototype warnings

* acpi-docs:
  Documentation: firmware-guide: gpio-properties: Clarify Explicit and Implicit
  Documentation: firmware-guide/ACPI: correct spelling
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Merge ACPI backlight driver changes, miscellaneous ACPI-related changes
and ACPI-related documentation updates for 6.3-rc1:

 - Fix Lenovo Ideapad Z570 DMI match in the ACPI backlight driver (Hans
   de Goede).

 - Silence missing prototype warnings in some places in the ACPI-related
   code (Ammar Faizi).

 - Make kobj_type structures used in the ACPI code constant (Thomas
   Weißschuh).

 - Correct spelling in firmware-guide/ACPI (Randy Dunlap).

 - Clarify the meaning of Explicit and Implicit in the _DSD GPIO
   properties documentation (Andy Shevchenko).

* acpi-video:
  ACPI: video: Fix Lenovo Ideapad Z570 DMI match

* acpi-misc:
  ACPI: make kobj_type structures constant
  ACPI: Silence missing prototype warnings

* acpi-docs:
  Documentation: firmware-guide: gpio-properties: Clarify Explicit and Implicit
  Documentation: firmware-guide/ACPI: correct spelling
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: make kobj_type structures constant</title>
<updated>2023-02-14T14:52:37+00:00</updated>
<author>
<name>Thomas Weißschuh</name>
<email>linux@weissschuh.net</email>
</author>
<published>2023-02-14T03:23:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a527b0111798ed7b9f49830989eaabfe537e09ef'/>
<id>a527b0111798ed7b9f49830989eaabfe537e09ef</id>
<content type='text'>
Since commit ee6d3dd4ed48 ("driver core: make kobj_type constant.")
the driver core allows the usage of const struct kobj_type.

Take advantage of this to constify the structure definitions to prevent
modification at runtime.

Signed-off-by: Thomas Weißschuh &lt;linux@weissschuh.net&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Since commit ee6d3dd4ed48 ("driver core: make kobj_type constant.")
the driver core allows the usage of const struct kobj_type.

Take advantage of this to constify the structure definitions to prevent
modification at runtime.

Signed-off-by: Thomas Weißschuh &lt;linux@weissschuh.net&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: CPPC: Fix some kernel-doc comments</title>
<updated>2023-02-09T20:17:11+00:00</updated>
<author>
<name>Yang Li</name>
<email>yang.lee@linux.alibaba.com</email>
</author>
<published>2023-02-08T02:31:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=fda7be2068973195343d14c1f760adcd481455c9'/>
<id>fda7be2068973195343d14c1f760adcd481455c9</id>
<content type='text'>
Add the description of @pcc_ss_id in pcc_data_alloc().
Add the description of @cpu_num in cppc_get_transition_latency().

clear the below warnings:
drivers/acpi/cppc_acpi.c:607: warning: Function parameter or member 'pcc_ss_id' not described in 'pcc_data_alloc'
drivers/acpi/cppc_acpi.c:1616: warning: Function parameter or member 'cpu_num' not described in 'cppc_get_transition_latency'

Reported-by: Abaci Robot &lt;abaci@linux.alibaba.com&gt;
Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=3983
Signed-off-by: Yang Li &lt;yang.lee@linux.alibaba.com&gt;
[ rjw: Dropped redundant empty code lines, minor edits ]
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add the description of @pcc_ss_id in pcc_data_alloc().
Add the description of @cpu_num in cppc_get_transition_latency().

clear the below warnings:
drivers/acpi/cppc_acpi.c:607: warning: Function parameter or member 'pcc_ss_id' not described in 'pcc_data_alloc'
drivers/acpi/cppc_acpi.c:1616: warning: Function parameter or member 'cpu_num' not described in 'cppc_get_transition_latency'

Reported-by: Abaci Robot &lt;abaci@linux.alibaba.com&gt;
Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=3983
Signed-off-by: Yang Li &lt;yang.lee@linux.alibaba.com&gt;
[ rjw: Dropped redundant empty code lines, minor edits ]
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: CPPC: Add AMD pstate energy performance preference cppc control</title>
<updated>2023-02-03T20:59:41+00:00</updated>
<author>
<name>Perry Yuan</name>
<email>Perry.Yuan@amd.com</email>
</author>
<published>2023-01-31T09:00:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=7bc1fcd399018245575974508c26e882da0bd915'/>
<id>7bc1fcd399018245575974508c26e882da0bd915</id>
<content type='text'>
Add support for setting and querying EPP preferences to the generic
CPPC driver.  This enables downstream drivers such as amd-pstate to discover
and use these values.

Downstream drivers that want to use the new symbols cppc_get_epp_caps
and cppc_set_epp_perf for querying and setting EPP preferences will need
to call cppc_set_epp_perf to enable the EPP function firstly.

Acked-by: Huang Rui &lt;ray.huang@amd.com&gt;
Reviewed-by: Mario Limonciello &lt;mario.limonciello@amd.com&gt;
Reviewed-by: Wyes Karny &lt;wyes.karny@amd.com&gt;
Tested-by: Wyes Karny &lt;wyes.karny@amd.com&gt;
Signed-off-by: Perry Yuan &lt;Perry.Yuan@amd.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add support for setting and querying EPP preferences to the generic
CPPC driver.  This enables downstream drivers such as amd-pstate to discover
and use these values.

Downstream drivers that want to use the new symbols cppc_get_epp_caps
and cppc_set_epp_perf for querying and setting EPP preferences will need
to call cppc_set_epp_perf to enable the EPP function firstly.

Acked-by: Huang Rui &lt;ray.huang@amd.com&gt;
Reviewed-by: Mario Limonciello &lt;mario.limonciello@amd.com&gt;
Reviewed-by: Wyes Karny &lt;wyes.karny@amd.com&gt;
Tested-by: Wyes Karny &lt;wyes.karny@amd.com&gt;
Signed-off-by: Perry Yuan &lt;Perry.Yuan@amd.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: use sysfs_emit() instead of scnprintf()</title>
<updated>2022-12-02T19:24:55+00:00</updated>
<author>
<name>ye xingchen</name>
<email>ye.xingchen@zte.com.cn</email>
</author>
<published>2022-11-30T08:16:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=92266c65e08793fda74d1d71edfbe25000807f39'/>
<id>92266c65e08793fda74d1d71edfbe25000807f39</id>
<content type='text'>
Replace the open-code with sysfs_emit() to simplify the code.

Signed-off-by: ye xingchen &lt;ye.xingchen@zte.com.cn&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Replace the open-code with sysfs_emit() to simplify the code.

Signed-off-by: ye xingchen &lt;ye.xingchen@zte.com.cn&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: CPPC: Disable FIE if registers in PCC regions</title>
<updated>2022-09-24T16:43:46+00:00</updated>
<author>
<name>Jeremy Linton</name>
<email>jeremy.linton@arm.com</email>
</author>
<published>2022-09-12T20:37:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ae2df912d1a557a3548be83da20851ac55f42ab3'/>
<id>ae2df912d1a557a3548be83da20851ac55f42ab3</id>
<content type='text'>
PCC regions utilize a mailbox to set/retrieve register values used by
the CPPC code. This is fine as long as the operations are
infrequent. With the FIE code enabled though the overhead can range
from 2-11% of system CPU overhead (ex: as measured by top) on Arm
based machines.

So, before enabling FIE assure none of the registers used by
cppc_get_perf_ctrs() are in the PCC region. Finally, add a module
parameter which can override the PCC region detection at boot or
module reload.

Signed-off-by: Jeremy Linton &lt;jeremy.linton@arm.com&gt;
Acked-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
Reviewed-by: Ionela Voinescu &lt;ionela.voinescu@arm.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
PCC regions utilize a mailbox to set/retrieve register values used by
the CPPC code. This is fine as long as the operations are
infrequent. With the FIE code enabled though the overhead can range
from 2-11% of system CPU overhead (ex: as measured by top) on Arm
based machines.

So, before enabling FIE assure none of the registers used by
cppc_get_perf_ctrs() are in the PCC region. Finally, add a module
parameter which can override the PCC region detection at boot or
module reload.

Signed-off-by: Jeremy Linton &lt;jeremy.linton@arm.com&gt;
Acked-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
Reviewed-by: Ionela Voinescu &lt;ionela.voinescu@arm.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: CPPC: Add ACPI disabled check to acpi_cpc_valid()</title>
<updated>2022-08-25T11:55:17+00:00</updated>
<author>
<name>Perry Yuan</name>
<email>Perry.Yuan@amd.com</email>
</author>
<published>2022-08-14T16:35:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a2a9d1850060e5d995136561d76e81d61414f076'/>
<id>a2a9d1850060e5d995136561d76e81d61414f076</id>
<content type='text'>
Make acpi_cpc_valid() check if ACPI is disabled, so that its callers
don't need to check that separately.  This will also cause the AMD
pstate driver to refuse to load right away when ACPI is disabled.

Also update the warning message in amd_pstate_init() to mention the
ACPI disabled case for completeness.

Signed-off-by: Perry Yuan &lt;Perry.Yuan@amd.com&gt;
[ rjw: Subject edits, new changelog ]
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Make acpi_cpc_valid() check if ACPI is disabled, so that its callers
don't need to check that separately.  This will also cause the AMD
pstate driver to refuse to load right away when ACPI is disabled.

Also update the warning message in amd_pstate_init() to mention the
ACPI disabled case for completeness.

Signed-off-by: Perry Yuan &lt;Perry.Yuan@amd.com&gt;
[ rjw: Subject edits, new changelog ]
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
