linux/drivers/acpi/acpi_processor.c, branch v6.4

ACPI: cpufreq: Use platform devices to load ACPI PPC and PCC drivers

2023-03-20T17:54:13Z

The acpi-cpufreq and pcc-cpufreq drivers are loaded through per-CPU module aliases. This can result in many unnecessary load requests during boot if another frequency module, such as intel_pstate, is already active. For instance, on a typical Intel system, one can observe that udev makes 2x#CPUs attempts to insert acpi_cpufreq and 1x#CPUs attempts for pcc_cpufreq. All these tries then fail if another frequency module is already registered. In the worst case, without the recent fix in commit 0254127ab977e ("module: Don't wait for GOING modules"), these module loads occupied all udev workers and had their initialization attempts ran sequentially. Resolving all these loads then on some larger machines took too long, prevented other hardware from getting its drivers initialized and resulted in a failed boot. Discussion over these duplicate module requests ended up with a conclusion that only one load attempt should be ideally made. Both acpi-cpufreq and pcc-cpufreq drivers use platform firmware controls which are defined by ACPI. It is possible to treat these interfaces as platform devices. The patch extends the ACPI parsing logic to check the ACPI namespace if the PPC or PCC interface is present and creates a virtual platform device for each if it is available. The acpi-cpufreq and pcc-cpufreq drivers are then updated to map to these devices. This allows to try loading acpi-cpufreq and pcc-cpufreq only once during boot and only if a given interface is available in the firmware. Signed-off-by: Petr Pavlu [ rjw: whitespace and error message log level adjustments, subject edits ] Signed-off-by: Rafael J. Wysocki

ACPI: processor: Replace deprecated CPU-hotplug functions

2021-08-04T18:25:54Z

The functions cpu_hotplug_begin, cpu_hotplug_done, get_online_cpus() and put_online_cpus() have been deprecated during the CPU hotplug rework. They map directly to cpus_write_lock(), cpus_write_unlock, cpus_read_lock() and cpus_read_unlock(). Replace deprecated CPU-hotplug functions with the official version. The behavior remains unchanged. Signed-off-by: Sebastian Andrzej Siewior 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: processor: fix some coding style issues

2021-04-08T14:27:02Z

Fix some coding style issues reported by checkpatch.pl, including the following types: ERROR: code indent should use tabs where possible WARNING: Block comments use a trailing */ on a separate line WARNING: Missing a blank line after declarations WARNING: labels should not be indented Signed-off-by: Xiaofei Tan Signed-off-by: Rafael J. Wysocki

ACPI: processor: Get rid of ACPICA message printing

2021-03-08T15:51:19Z

The ACPI_DEBUG_PRINT() and ACPI_EXCEPTION() macros are used for message printing in the ACPICA code and they should not be used elsewhere. Special configuration (either kernel command line or sysfs-based) is needed to see the messages printed by them and the format of those messages is also special and convoluted. For this reason, replace all of the ACPI_DEBUG_PRINT() and ACPI_EXCEPTION() instances in the ACPI processor driver with corresponding dev_*(), acpi_handle_*() and pr_*() calls depending on the context in which they appear. Also drop the ACPI_PROCESSOR_COMPONENT definition that is not going to be necessary any more. Signed-off-by: Rafael J. Wysocki Reviewed-by: Hanjun Guo

ACPI: processor: remove comment regarding string _UID support

2020-10-16T16:11:27Z

ACPI 6.3 Errata A no longer allows _UID to return a string except for Itanium (for historical reasons) as stated in section 5.2.12: "From ACPI Specification 6.3 onward, all processor objects for all architectures except Itanium must now use Device() objects with an _HID of ACPI0007, and use only integer _UID values." Therefore, the "we don't handle string _UIDs yet" comment, which implies a missing feature, is redundant, so drop it. Signed-off-by: Alex Hung [ rjw: Subject and changelog edits ] Signed-off-by: Rafael J. Wysocki

ACPI: processor: Print more information when acpi_processor_evaluate_cst() fails

2020-09-21T16:24:35Z

Some platforms have bogus _CST which might cause unexpectd behavior in the CPU idle driver. Some bogus _CST might be unable to be disassembled by acpica-tools due to broken format. Print extra log if the _CST extraction/verification failes. This can be used to help narrow down why the CPU idle driver fails to behave as expected. Suggested-by: Zhang Rui Signed-off-by: Chen Yu [ rjw: Subject and changelog edits ] Signed-off-by: Rafael J. Wysocki

ACPI: Use fallthrough pseudo-keyword

2020-07-09T12:09:28Z

Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. Link: https://www.kernel.org/doc/html/latest/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through # [1] Signed-off-by: Gustavo A. R. Silva Signed-off-by: Rafael J. Wysocki

ACPI: processor: Export acpi_processor_evaluate_cst()

2019-12-27T10:02:07Z

The intel_idle driver will be modified to use ACPI _CST subsequently and it will need to call acpi_processor_evaluate_cst(), so move that function to acpi_processor.c so that it is always present (which is required by intel_idle) and export it to modules to allow the ACPI processor driver (which is modular) to call it. No intentional functional impact. Signed-off-by: Rafael J. Wysocki

ACPI: processor: Export function to claim _CST control

2019-12-16T11:06:18Z

The intel_idle driver will be modified to use ACPI _CST subsequently and it will need to notify the platform firmware of that if acpi_gbl_FADT.cst_control is set, so add a routine for this purpose, acpi_processor_claim_cst_control(), to acpi_processor.c (so that it is always present which is required by intel_idle) and export it to allow the ACPI processor driver (which is modular) to call it. No intentional functional impact. Signed-off-by: Rafael J. Wysocki