user/sven/linux.git/drivers/acpi/cppc_acpi.c, branch v5.15.57

ACPI: CPPC: Assume no transition latency if no PCCT

2022-06-09T08:22:39Z

[ Upstream commit 6380b7b2b29da9d9c5ab2d4a265901cd93ba3696 ] The transition_delay_us (struct cpufreq_policy) is currently defined as: Preferred average time interval between consecutive invocations of the driver to set the frequency for this policy. To be set by the scaling driver (0, which is the default, means no preference). The transition_latency represents the amount of time necessary for a CPU to change its frequency. A PCCT table advertises mutliple values: - pcc_nominal: Expected latency to process a command, in microseconds - pcc_mpar: The maximum number of periodic requests that the subspace channel can support, reported in commands per minute. 0 indicates no limitation. - pcc_mrtt: The minimum amount of time that OSPM must wait after the completion of a command before issuing the next command, in microseconds. cppc_get_transition_latency() allows to get the max of them. commit d4f3388afd48 ("cpufreq / CPPC: Set platform specific transition_delay_us") allows to select transition_delay_us based on the platform, and fallbacks to cppc_get_transition_latency() otherwise. If _CPC objects are not using PCC channels (no PPCT table), the transition_delay_us is set to CPUFREQ_ETERNAL, leading to really long periods between frequency updates (~4s). If the desired_reg, where performance requests are written, is in SystemMemory or SystemIo ACPI address space, there is no delay in requests. So return 0 instead of CPUFREQ_ETERNAL, leading to transition_delay_us being set to LATENCY_MULTIPLIER us (1000 us). This patch also adds two macros to check the address spaces. Signed-off-by: Pierre Gondois Reviewed-by: Sudeep Holla Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

ACPI: CPPC: Avoid out of bounds access when parsing _CPC data

2022-04-08T12:24:12Z

commit 40d8abf364bcab23bc715a9221a3c8623956257b upstream. If the NumEntries field in the _CPC return package is less than 2, do not attempt to access the "Revision" element of that package, because it may not be present then. Fixes: 337aadff8e45 ("ACPI: Introduce CPU performance controls using CPPC") BugLink: https://lore.kernel.org/lkml/20220322143534.GC32582@xsang-OptiPlex-9020/ Reported-by: kernel test robot Signed-off-by: Rafael J. Wysocki Reviewed-by: Huang Rui Signed-off-by: Greg Kroah-Hartman

ACPI: CPPC: Check present CPUs for determining _CPC is valid

2022-01-27T10:04:51Z

[ Upstream commit 2aeca6bd02776d7f56a49a32be0dd184f204d888 ] As this is a static check, it should be based upon what is currently present on the system. This makes probeing more deterministic. While local APIC flags field (lapic_flags) of cpu core in MADT table is 0, then the cpu core won't be enabled. In this case, _CPC won't be found in this core, and return back to _CPC invalid with walking through possible cpus (include disable cpus). This is not expected, so switch to check present CPUs instead. Reported-by: Jinzhou Su Signed-off-by: Mario Limonciello Signed-off-by: Huang Rui Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

ACPI: CPPC: Add NULL pointer check to cppc_get_perf()

2021-12-01T08:04:38Z

commit 935dff305da2be7957a5ce8f07f45d6c4c1c6984 upstream. Check cpc_desc against NULL in cppc_get_perf(), so it doesn't crash down the road if cpc_desc is NULL. Fixes: 0654cf05d17b ("ACPI: CPPC: Introduce cppc_get_nominal_perf()") Reported-by: Kai-Heng Feng Signed-off-by: Rafael J. Wysocki Cc: 5.15+ # 5.15+ Tested-by: Kai-Heng Feng Signed-off-by: Greg Kroah-Hartman

ACPI: CPPC: Introduce cppc_get_nominal_perf()

2021-09-07T19:15:16Z

On some systems the nominal_perf value retrieved via CPPC is just a constant and fetching it doesn't require accessing any registers, so if it is the only CPPC capability that's needed, it is wasteful to run cppc_get_perf_caps() in order to get just that value alone, especially when this is done for CPUs other than the one running the code. For this reason, introduce cppc_get_nominal_perf() allowing nominal_perf to be obtained individually, by generalizing the existing cppc_get_desired_perf() (and renaming it) so it can be used to retrieve any specific CPPC capability value. While at it, clean up the cppc_get_desired_perf() kerneldoc comment a bit. Signed-off-by: Rafael J. Wysocki

Merge branch 'acpi-misc'

2021-04-26T15:04:41Z

* acpi-misc: ACPI: dock: fix some coding style issues ACPI: sysfs: fix some coding style issues ACPI: PM: add a missed blank line after declarations ACPI: custom_method: fix a coding style issue ACPI: CPPC: fix some coding style issues ACPI: button: fix some coding style issues ACPI: battery: fix some coding style issues ACPI: acpi_pad: add a missed blank line after declarations ACPI: LPSS: add a missed blank line after declarations ACPI: ipmi: remove useless return statement for void function ACPI: processor: fix some coding style issues ACPI: APD: fix a block comment align issue ACPI: AC: fix some coding style issues ACPI: fix various typos in comments

ACPI: CPPC: Replace cppc_attr with kobj_attribute

2021-04-08T17:58:12Z

All of the CPPC sysfs show functions are called via indirect call in kobj_attr_show(), where they should be of type ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr, char *buf); because that is the type of the ->show() member in 'struct kobj_attribute' but they are actually of type ssize_t (*show)(struct kobject *kobj, struct attribute *attr, char *buf); because of the ->show() member in 'struct cppc_attr', resulting in a Control Flow Integrity violation [1]. $ cat /sys/devices/system/cpu/cpu0/acpi_cppc/highest_perf 3400 $ dmesg | grep "CFI failure" [ 175.970559] CFI failure (target: show_highest_perf+0x0/0x8): As far as I can tell, the only difference between 'struct cppc_attr' and 'struct kobj_attribute' aside from the type of the attr parameter is the type of the count parameter in the ->store() member (ssize_t vs. size_t), which does not actually matter because all of these nodes are read-only. Eliminate 'struct cppc_attr' in favor of 'struct kobj_attribute' to fix the violation. [1]: https://lore.kernel.org/r/20210401233216.2540591-1-samitolvanen@google.com/ Fixes: 158c998ea44b ("ACPI / CPPC: add sysfs support to compute delivered performance") Link: https://github.com/ClangBuiltLinux/linux/issues/1343 Signed-off-by: Nathan Chancellor Signed-off-by: Rafael J. Wysocki

ACPI: CPPC: fix some coding style issues

2021-04-08T14:27:02Z

Fix some coding style issues reported by checkpatch.pl, including the following types: WARNING: Missing a blank line after declarations WARNING: unnecessary whitespace before a quoted newline ERROR: spaces required around that '>=' ERROR: switch and case should be at the same indent Signed-off-by: Xiaofei Tan Signed-off-by: Rafael J. Wysocki

ACPI: CPPC: Add emtpy stubs of functions for CONFIG_ACPI_CPPC_LIB unset

2021-03-23T18:44:17Z

For convenience, add empty stubs of library functions defined in cppc_acpi.c for the CONFIG_ACPI_CPPC_LIB unset case. Because one of them needs to return CPUFREQ_ETERNAL, include linux/cpufreq.h into the CPPC library header file and drop the direct inclusion of it from cppc_acpi.c. Signed-off-by: Rafael J. Wysocki Tested-by: Chen Yu

ACPI: fix various typos in comments

2021-03-19T16:45:49Z

Fix trivial ACPI driver comment typos. s/notifcations/notifications/ s/Ajust/Adjust/ s/preform/perform/ s/atrributes/attributes/ s/Souce/Source/ s/Evalutes/Evaluates/ s/Evalutes/Evaluates/ s/specifiy/specify/ s/promixity/proximity/ s/presuambly/presumably/ s/Evalute/Evaluate/ s/specificed/specified/ s/rountine/routine/ s/previosuly/previously/ Change comment referencing pcc_send_cmd to send_pcc_cmd. Signed-off-by: Tom Saeger Reviewed-by: Randy Dunlap Signed-off-by: Rafael J. Wysocki