linux.git/drivers/acpi/processor_core.c, branch v6.6.132

ACPI: processor_core: fix map_x2apic_id for amd-pstate on am4

2026-01-11T14:21:31+00:00

[ Upstream commit 17e7972979e147cc51d4a165e6b6b0f93273ca68 ]

On all AMD AM4 systems I have seen, e.g ASUS X470-i, Pro WS X570 Ace
and equivalent Gigabyte, amd-pstate does not initialize when the
x2apic is enabled in the BIOS. Kernel debug messages include:

[    0.315438] acpi LNXCPU:00: Failed to get CPU physical ID.
[    0.354756] ACPI CPPC: No CPC descriptor for CPU:0
[    0.714951] amd_pstate: the _CPC object is not present in SBIOS or ACPI disabled

I tracked this down to map_x2apic_id() checking device_declaration
passed in via the type argument of acpi_get_phys_id() via
map_madt_entry() while map_lapic_id() does not.

It appears these BIOSes use Processor statements for declaring the CPUs
in the ACPI namespace instead of processor device objects (which should
have been used). CPU declarations via Processor statements were
deprecated in ACPI 6.0 that was released 10 years ago. They should not
be used any more in any contemporary platform firmware.

I tried to contact Asus support multiple times, but never received a
reply nor did any BIOS update ever change this.

Fix amd-pstate w/ x2apic on am4 by allowing map_x2apic_id() to work with
CPUs declared via Processor statements for IDs less than 255, which is
consistent with ACPI 5.0 that still allowed Processor statements to be
used for declaring CPUs.

Fixes: 7237d3de78ff ("x86, ACPI: add support for x2apic ACPI extensions")
Signed-off-by: René Rebe 
[ rjw: Changelog edits ]
Link: https://patch.msgid.link/20251126.165513.1373131139292726554.rene@exactco.de
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin

ACPI: processor: LoongArch: Get physical ID from MADT

2023-08-17T16:39:28+00:00

With ACPI Spec 6.5 chapter 5.2.12.20, each processor in LoongArch
systems has a Core Programmable Interrupt Controller in MADT. The
value of its type is 0x11 in the spec and defined as enum variable
ACPI_MADT_TYPE_CORE_PIC in the Linux kernel.

Physical IDs can be retrieved from MADT for LoongArch systems during
initialization and they can be retrieved from the _MAT output for
hotplug CPUs.

Add physical CPU ID enumeration for LoongArch systems.

Signed-off-by: Bibo Mao 
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki

ACPI: processor_core: RISC-V: Enable mapping processor to the hartid

2023-06-01T15:45:02+00:00

processor_core needs arch-specific functions to map the ACPI ID
to the physical ID. In RISC-V platforms, hartid is the physical id
and RINTC structure in MADT provides this mapping. Add arch-specific
function to get this mapping from RINTC.

Signed-off-by: Sunil V L 
Acked-by: Rafael J. Wysocki 
Reviewed-by: Andrew Jones 
Link: https://lore.kernel.org/r/20230515054928.2079268-8-sunilvl@ventanamicro.com
Signed-off-by: Palmer Dabbelt

ACPI: processor: Remove dead ACPICA debug code

2020-09-25T16:25:51+00:00

The ACPICA debug code is not used anywhere in processor_core.c
and processor_thermal.c, remove it.

Signed-off-by: Hanjun Guo 
[ rjw: Subject edit ]
Signed-off-by: Rafael J. Wysocki

treewide: Add SPDX license identifier for missed files

2019-05-21T08:50:45+00:00

Add SPDX license identifiers to all files which:

 - Have no license information of any form

 - Have EXPORT_.*_SYMBOL_GPL inside which was used in the
   initial scan/conversion to ignore the file

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

xen/ACPI: don't upload Px/Cx data for disabled processors

2018-08-20T18:46:18+00:00

This is unnecessary and triggers a warning in the hypervisor.

Often systems have more processor entries in their ACPI tables than are
actually installed/active. The ACPI_STA_DEVICE_PRESENT bit cannot be
reliably used, but the ACPI_MADT_ENABLED bit can. In order to not
introduce new functions in the main ACPI processor driver code, simply
use acpi_get_phys_id(), which does more than we need, but which checks
the MADT enabled bit in the process. Any CPU for which we can't
determine the APIC ID is unlikely to work properly anyway, so the extra
checks done by acpi_get_phys_id() should do no harm.

Signed-off-by: Jan Beulich 
Reviewed-by: Juergen Gross 
Acked-by: Rafael J. Wysocki 
Signed-off-by: Boris Ostrovsky

Revert"x86/acpi: Enable MADT APIs to return disabled apicids"

2017-03-11T13:41:18+00:00

Revert: 8ad893faf2ea ("x86/acpi: Enable MADT APIs to return disabled apicids")

Remove the leftovers of the boot time 'cpuid <-> nodeid' mapping approach.

Signed-off-by: Dou Liyang 
Tested-by: Xiaolong Ye 
Cc: rjw@rjwysocki.net
Cc: linux-acpi@vger.kernel.org
Cc: guzheng1@huawei.com
Cc: izumi.taku@jp.fujitsu.com
Cc: lenb@kernel.org
Link: http://lkml.kernel.org/r/1488528147-2279-3-git-send-email-douly.fnst@cn.fujitsu.com
Signed-off-by: Thomas Gleixner

Revert "x86/acpi: Set persistent cpuid <-> nodeid mapping when booting"

2017-03-11T13:41:18+00:00

Revert: dc6db24d2476 ("x86/acpi: Set persistent cpuid <-> nodeid mapping when booting")

The mapping of "cpuid <-> nodeid" is established at boot time via ACPI
tables to keep associations of workqueues and other node related items
consistent across cpu hotplug.

But, ACPI tables are unreliable and failures with that boot time mapping
have been reported on machines where the ACPI table and the physical
information which is retrieved at actual hotplug is inconsistent.

Revert the mapping implementation so it can be replaced with a less error
prone approach.

Signed-off-by: Dou Liyang 
Tested-by: Xiaolong Ye 
Cc: rjw@rjwysocki.net
Cc: linux-acpi@vger.kernel.org
Cc: guzheng1@huawei.com
Cc: izumi.taku@jp.fujitsu.com
Cc: lenb@kernel.org
Link: http://lkml.kernel.org/r/1488528147-2279-2-git-send-email-douly.fnst@cn.fujitsu.com
Signed-off-by: Thomas Gleixner

ACPI / osl: Remove acpi_get_table_with_size()/early_acpi_os_unmap_memory() users

2016-12-21T01:36:38+00:00

This patch removes the users of the deprectated APIs:
 acpi_get_table_with_size()
 early_acpi_os_unmap_memory()
The following APIs should be used instead of:
 acpi_get_table()
 acpi_put_table()

The deprecated APIs are invented to be a replacement of acpi_get_table()
during the early stage so that the early mapped pointer will not be stored
in ACPICA core and thus the late stage acpi_get_table() won't return a
wrong pointer. The mapping size is returned just because it is required by
early_acpi_os_unmap_memory() to unmap the pointer during early stage.

But as the mapping size equals to the acpi_table_header.length
(see acpi_tb_init_table_descriptor() and acpi_tb_validate_table()), when
such a convenient result is returned, driver code will start to use it
instead of accessing acpi_table_header to obtain the length.

Thus this patch cleans up the drivers by replacing returned table size with
acpi_table_header.length, and should be a no-op.

Reported-by: Dan Williams 
Signed-off-by: Lv Zheng 
Signed-off-by: Rafael J. Wysocki

acpi: Fix broken error check in map_processor()

2016-09-23T16:04:56+00:00

map_processor() checks the cpuid value returned by acpi_map_cpuid() for -1
but acpi_map_cpuid() returns -EINVAL in case of error.

As a consequence the error is ignored and the following access into percpu
data with that negative cpuid results in a boot crash.

This happens always when NR_CPUS/nr_cpu_ids is smaller than the number of
processors listed in the ACPI tables.

Use a proper error check for id < 0 so the function returns instead of
trying to map CPU#(-EINVAL).

Reported-by: Ingo Molnar 
Signed-off-by: Thomas Gleixner 
Cc: Dou Liyang 
Cc: Gu Zheng 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Tang Chen 
Cc: Zhu Guihua 
Cc: akpm@linux-foundation.org
Cc: chen.tang@easystack.cn
Cc: cl@linux.com
Cc: gongzhaogang@inspur.com
Cc: isimatu.yasuaki@jp.fujitsu.com
Cc: izumi.taku@jp.fujitsu.com
Cc: kamezawa.hiroyu@jp.fujitsu.com
Cc: len.brown@intel.com
Cc: lenb@kernel.org
Cc: linux-acpi@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: mika.j.penttila@gmail.com
Cc: rafael@kernel.org
Cc: rjw@rjwysocki.net
Cc: tj@kernel.org
Cc: yasu.isimatu@gmail.com
Fixes: dc6db24d2476 ("x86/acpi: Set persistent cpuid <-> nodeid mapping when booting")
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1609231705570.5640@nanos
Signed-off-by: Ingo Molnar