<feed xmlns='http://www.w3.org/2005/Atom'>
<title>lwn.git/drivers/cpufreq/cppc_cpufreq.c, branch docs-5.6</title>
<subtitle>Linux kernel documentation tree maintained by Jonathan Corbet</subtitle>
<id>http://mirrors.hust.edu.cn/git/lwn.git/atom?h=docs-5.6</id>
<link rel='self' href='http://mirrors.hust.edu.cn/git/lwn.git/atom?h=docs-5.6'/>
<link rel='alternate' type='text/html' href='http://mirrors.hust.edu.cn/git/lwn.git/'/>
<updated>2019-06-05T15:37:17+00:00</updated>
<entry>
<title>treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441</title>
<updated>2019-06-05T15:37:17+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2019-06-01T08:08:55+00:00</published>
<link rel='alternate' type='text/html' href='http://mirrors.hust.edu.cn/git/lwn.git/commit/?id=b886d83c5b621abc84ff9616f14c529be3f6b147'/>
<id>urn:sha1:b886d83c5b621abc84ff9616f14c529be3f6b147</id>
<content type='text'>
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation version 2 of the license

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 315 file(s).

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Allison Randal &lt;allison@lohutok.net&gt;
Reviewed-by: Armijn Hemel &lt;armijn@tjaldur.nl&gt;
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190115.503150771@linutronix.de
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>cpufreq / cppc: Work around for Hisilicon CPPC cpufreq</title>
<updated>2019-02-18T10:27:42+00:00</updated>
<author>
<name>Xiongfeng Wang</name>
<email>wangxiongfeng2@huawei.com</email>
</author>
<published>2019-02-17T03:54:15+00:00</published>
<link rel='alternate' type='text/html' href='http://mirrors.hust.edu.cn/git/lwn.git/commit/?id=6c8d750f9784cef32a8cffdad74c8a351b4ca3a6'/>
<id>urn:sha1:6c8d750f9784cef32a8cffdad74c8a351b4ca3a6</id>
<content type='text'>
Hisilicon chips do not support delivered performance counter register
and reference performance counter register. But the platform can
calculate the real performance using its own method. We reuse the
desired performance register to store the real performance calculated by
the platform. After the platform finished the frequency adjust, it gets
the real performance and writes it into desired performance register. Os
can use it to calculate the real frequency.

Signed-off-by: Xiongfeng Wang &lt;wangxiongfeng2@huawei.com&gt;
[ rjw: Drop unnecessary braces ]
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
</entry>
<entry>
<title>cpufreq / CPPC: Mark acpi_ids as used</title>
<updated>2018-10-03T11:36:27+00:00</updated>
<author>
<name>Nathan Chancellor</name>
<email>natechancellor@gmail.com</email>
</author>
<published>2018-10-02T22:34:57+00:00</published>
<link rel='alternate' type='text/html' href='http://mirrors.hust.edu.cn/git/lwn.git/commit/?id=8ff3c22688ff3616ee53c5c54b3ee66a73326175'/>
<id>urn:sha1:8ff3c22688ff3616ee53c5c54b3ee66a73326175</id>
<content type='text'>
Clang warns:

drivers/cpufreq/cppc_cpufreq.c:431:36: warning: variable 'cppc_acpi_ids'
is not needed and will not be emitted [-Wunneeded-internal-declaration]
static const struct acpi_device_id cppc_acpi_ids[] = {
                                   ^
1 warning generated.

Mark the definition as used so that Clang understands we don't want this
warning while not inhibiting Clang's dead code elimination from removing
the unreferenced internal symbol when moving the data it contains to the
globally available symbol via MODULE_DEVICE_TABLE.

$ nm -S drivers/cpufreq/cppc_cpufreq.o | grep acpi | tail -1
0000000000000000 0000000000000040 R __mod_acpi__cppc_acpi_ids_device_table

Suggested-by: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Reviewed-by: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Signed-off-by: Nathan Chancellor &lt;natechancellor@gmail.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
</entry>
<entry>
<title>cpufreq / CPPC: Add cpuinfo_cur_freq support for CPPC</title>
<updated>2018-07-18T08:13:16+00:00</updated>
<author>
<name>George Cherian</name>
<email>george.cherian@cavium.com</email>
</author>
<published>2018-07-12T06:07:55+00:00</published>
<link rel='alternate' type='text/html' href='http://mirrors.hust.edu.cn/git/lwn.git/commit/?id=33477d84c26bbfa626da2c032e567a90dd70a528'/>
<id>urn:sha1:33477d84c26bbfa626da2c032e567a90dd70a528</id>
<content type='text'>
Per Section 8.4.7.1.3 of ACPI 6.2, the platform provides performance
feedback via set of performance counters. To determine the actual
performance level delivered over time, OSPM may read a set of
performance counters from the Reference Performance Counter Register
and the Delivered Performance Counter Register.

OSPM calculates the delivered performance over a given time period by
taking a beginning and ending snapshot of both the reference and
delivered performance counters, and calculating:

delivered_perf = reference_perf X (delta of delivered_perf counter / delta of reference_perf counter).

Implement the above and hook this up to the cpufreq-&gt;get method.

Signed-off-by: George Cherian &lt;george.cherian@cavium.com&gt;
Acked-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
Acked-by: Prashanth Prakash &lt;pprakash@codeaurora.org&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
</entry>
<entry>
<title>treewide: kzalloc() -&gt; kcalloc()</title>
<updated>2018-06-12T23:19:22+00:00</updated>
<author>
<name>Kees Cook</name>
<email>keescook@chromium.org</email>
</author>
<published>2018-06-12T21:03:40+00:00</published>
<link rel='alternate' type='text/html' href='http://mirrors.hust.edu.cn/git/lwn.git/commit/?id=6396bb221514d2876fd6dc0aa2a1f240d99b37bb'/>
<id>urn:sha1:6396bb221514d2876fd6dc0aa2a1f240d99b37bb</id>
<content type='text'>
The kzalloc() function has a 2-factor argument form, kcalloc(). This
patch replaces cases of:

        kzalloc(a * b, gfp)

with:
        kcalloc(a * b, gfp)

as well as handling cases of:

        kzalloc(a * b * c, gfp)

with:

        kzalloc(array3_size(a, b, c), gfp)

as it's slightly less ugly than:

        kzalloc_array(array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

        kzalloc(4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
  kzalloc(
-	(sizeof(TYPE)) * E
+	sizeof(TYPE) * E
  , ...)
|
  kzalloc(
-	(sizeof(THING)) * E
+	sizeof(THING) * E
  , ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
  kzalloc(
-	sizeof(u8) * (COUNT)
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(__u8) * (COUNT)
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(char) * (COUNT)
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(unsigned char) * (COUNT)
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(u8) * COUNT
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(__u8) * COUNT
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(char) * COUNT
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(unsigned char) * COUNT
+	COUNT
  , ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * (COUNT_ID)
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * COUNT_ID
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * (COUNT_CONST)
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * COUNT_CONST
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * (COUNT_ID)
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * COUNT_ID
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * (COUNT_CONST)
+	COUNT_CONST, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * COUNT_CONST
+	COUNT_CONST, sizeof(THING)
  , ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

- kzalloc
+ kcalloc
  (
-	SIZE * COUNT
+	COUNT, SIZE
  , ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
  kzalloc(
-	sizeof(TYPE) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kzalloc(
-	sizeof(TYPE) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kzalloc(
-	sizeof(TYPE) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kzalloc(
-	sizeof(TYPE) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kzalloc(
-	sizeof(THING) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kzalloc(
-	sizeof(THING) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kzalloc(
-	sizeof(THING) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kzalloc(
-	sizeof(THING) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
  kzalloc(
-	sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kzalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kzalloc(
-	sizeof(THING1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kzalloc(
-	sizeof(THING1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kzalloc(
-	sizeof(TYPE1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
|
  kzalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
  kzalloc(
-	(COUNT) * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	COUNT * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	COUNT * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	(COUNT) * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	COUNT * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	(COUNT) * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	(COUNT) * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	COUNT * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
  kzalloc(C1 * C2 * C3, ...)
|
  kzalloc(
-	(E1) * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kzalloc(
-	(E1) * (E2) * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kzalloc(
-	(E1) * (E2) * (E3)
+	array3_size(E1, E2, E3)
  , ...)
|
  kzalloc(
-	E1 * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
  kzalloc(sizeof(THING) * C2, ...)
|
  kzalloc(sizeof(TYPE) * C2, ...)
|
  kzalloc(C1 * C2 * C3, ...)
|
  kzalloc(C1 * C2, ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * (E2)
+	E2, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * E2
+	E2, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * (E2)
+	E2, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * E2
+	E2, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	(E1) * E2
+	E1, E2
  , ...)
|
- kzalloc
+ kcalloc
  (
-	(E1) * (E2)
+	E1, E2
  , ...)
|
- kzalloc
+ kcalloc
  (
-	E1 * E2
+	E1, E2
  , ...)
)

Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
</content>
</entry>
<entry>
<title>Merge branches 'acpi-cppc', 'acpi-misc', 'acpi-battery' and 'acpi-ac'</title>
<updated>2018-06-04T08:43:34+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2018-06-04T08:43:34+00:00</published>
<link rel='alternate' type='text/html' href='http://mirrors.hust.edu.cn/git/lwn.git/commit/?id=6c128e798f5b481c22cd3f7a8d5df16f1a77ea7e'/>
<id>urn:sha1:6c128e798f5b481c22cd3f7a8d5df16f1a77ea7e</id>
<content type='text'>
* acpi-cppc:
  mailbox: PCC: erroneous error message when parsing ACPI PCCT
  ACPI / CPPC: Fix invalid PCC channel status errors
  ACPI / CPPC: Document CPPC sysfs interface
  cpufreq / CPPC: Support for CPPC v3
  ACPI / CPPC: Check for valid PCC subspace only if PCC is used
  ACPI / CPPC: Add support for CPPC v3

* acpi-misc:
  ACPI: Add missing prototype_for arch_post_acpi_subsys_init()
  ACPI: add missing newline to printk

* acpi-battery:
  ACPI / battery: Add quirk to avoid checking for PMIC with native driver
  ACPI / battery: Ignore AC state in handle_discharging on systems where it is broken
  ACPI / battery: Add handling for devices which wrongly report discharging state
  ACPI / battery: Remove initializer for unused ident dmi_system_id
  ACPI / AC: Remove initializer for unused ident dmi_system_id

* acpi-ac:
  ACPI / AC: Add quirk to avoid checking for PMIC with native driver
</content>
</entry>
<entry>
<title>cpufreq / CPPC: Set platform specific transition_delay_us</title>
<updated>2018-04-30T08:14:08+00:00</updated>
<author>
<name>Prashanth Prakash</name>
<email>pprakash@codeaurora.org</email>
</author>
<published>2018-04-27T17:35:27+00:00</published>
<link rel='alternate' type='text/html' href='http://mirrors.hust.edu.cn/git/lwn.git/commit/?id=d4f3388afd488ed15368fa7413b8bd6d1f98bb1d'/>
<id>urn:sha1:d4f3388afd488ed15368fa7413b8bd6d1f98bb1d</id>
<content type='text'>
Add support to specify platform specific transition_delay_us instead
of using the transition delay derived from PCC.

With commit 3d41386d556d (cpufreq: CPPC: Use transition_delay_us
depending transition_latency) we are setting transition_delay_us
directly and not applying the LATENCY_MULTIPLIER. Because of that,
on Qualcomm Centriq we can end up with a very high rate of frequency
change requests when using the schedutil governor (default
rate_limit_us=10 compared to an earlier value of 10000).

The PCC subspace describes the rate at which the platform can accept
commands on the CPPC's PCC channel. This includes read and write
command on the PCC channel that can be used for reasons other than
frequency transitions. Moreover the same PCC subspace can be used by
multiple freq domains and deriving transition_delay_us from it as we
do now can be sub-optimal.

Moreover if a platform does not use PCC for desired_perf register then
there is no way to compute the transition latency or the delay_us.

CPPC does not have a standard defined mechanism to get the transition
rate or the latency at the moment.

Given the above limitations, it is simpler to have a platform specific
transition_delay_us and rely on PCC derived value only if a platform
specific value is not available.

Signed-off-by: Prashanth Prakash &lt;pprakash@codeaurora.org&gt;
Cc: 4.14+ &lt;stable@vger.kernel.org&gt; # 4.14+
Fixes: 3d41386d556d (cpufreq: CPPC: Use transition_delay_us depending transition_latency)
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
</entry>
<entry>
<title>cpufreq / CPPC: Support for CPPC v3</title>
<updated>2018-04-24T10:33:28+00:00</updated>
<author>
<name>Prashanth Prakash</name>
<email>pprakash@codeaurora.org</email>
</author>
<published>2018-04-04T18:14:52+00:00</published>
<link rel='alternate' type='text/html' href='http://mirrors.hust.edu.cn/git/lwn.git/commit/?id=256f19d212f260c955a90a0efc7753e11b18e34c'/>
<id>urn:sha1:256f19d212f260c955a90a0efc7753e11b18e34c</id>
<content type='text'>
Use CPPC v3 entries to convert the abstract processor performance to
processor frequency in KHz.

Signed-off-by: Prashanth Prakash &lt;pprakash@codeaurora.org&gt;
Acked-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
</entry>
<entry>
<title>cpufreq: CPPC: Initialize shared perf capabilities of CPUs</title>
<updated>2018-04-10T06:38:02+00:00</updated>
<author>
<name>Shunyong Yang</name>
<email>shunyong.yang@hxt-semitech.com</email>
</author>
<published>2018-04-06T02:43:49+00:00</published>
<link rel='alternate' type='text/html' href='http://mirrors.hust.edu.cn/git/lwn.git/commit/?id=8913315e9459b146e5888ab5138e10daa061b885'/>
<id>urn:sha1:8913315e9459b146e5888ab5138e10daa061b885</id>
<content type='text'>
When multiple CPUs are related in one cpufreq policy, the first online
CPU will be chosen by default to handle cpufreq operations. Let's take
cpu0 and cpu1 as an example.

When cpu0 is offline, policy-&gt;cpu will be shifted to cpu1. cpu1's perf
capabilities should be initialized. Otherwise, perf capabilities are 0s
and speed change can not take effect.

This patch copies perf capabilities of the first online CPU to other
shared CPUs when policy shared type is CPUFREQ_SHARED_TYPE_ANY.

Acked-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
Signed-off-by: Shunyong Yang &lt;shunyong.yang@hxt-semitech.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
</entry>
<entry>
<title>cpufreq: CPPC: Don't set transition_latency</title>
<updated>2018-04-10T06:38:02+00:00</updated>
<author>
<name>Viresh Kumar</name>
<email>viresh.kumar@linaro.org</email>
</author>
<published>2018-04-02T07:20:53+00:00</published>
<link rel='alternate' type='text/html' href='http://mirrors.hust.edu.cn/git/lwn.git/commit/?id=b8b10bc2015cd91350aac68447377c8410a48865'/>
<id>urn:sha1:b8b10bc2015cd91350aac68447377c8410a48865</id>
<content type='text'>
Now that the driver has started to set transition_delay_us directly,
there is no need to set transition_latency along with it, as it is not
used by the cpufreq core.

Signed-off-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
</entry>
</feed>
