linux/include
Christian Loehle 11055a46f3 ACPI: CPPC: Check all controls for fast switching
ACPI 6.2, Section 6.2.11.2 permits _CPC registers to use flexible
address spaces. Linux advertises that capability through _OSC and parses
the address space of each _CPC register independently. A directly
accessible DESIRED_PERF combined with PCC-backed limits is therefore a
valid configuration.

cppc_allow_fast_switch() only checks DESIRED_PERF, although the fast-switch
callback passes DESIRED_PERF, MIN_PERF and MAX_PERF to cppc_set_perf(). If
a limit uses PCC, that function can sleep while called from scheduler
context.

Allow fast switching only when every supported control used by the
callback has an address space already accepted for fast access. Check the
complete policy domain, including initialized CPUs that are currently
offline and may later become the policy's managing CPU.

Fixes: 658fa7b1c4 ("ACPI: CPPC: Add cppc_get_perf() API to read performance controls")
Cc: stable@vger.kernel.org
Signed-off-by: Christian Loehle <christian.loehle@arm.com>
Link: https://patch.msgid.link/20260722093825.1030594-2-christian.loehle@arm.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2026-07-22 15:09:14 +02:00
..
acpi ACPI: CPPC: Check all controls for fast switching 2026-07-22 15:09:14 +02:00
asm-generic mm.git review status for mm-hotfixes-stable..mm-nonmm-stable 2026-06-21 13:20:19 -07:00
clocksource
crypto Networking changes for 7.2. 2026-06-17 08:17:00 +01:00
cxl cxl/region: Introduce devm_cxl_probe_mem() 2026-06-12 13:47:30 -07:00
drm drm/amd/display: Force PWM backlight on Lenovo Legion 5 15ARH05 2026-07-17 17:41:15 -04:00
dt-bindings SoC fixes for 7.2 2026-07-17 08:52:09 -07:00
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keys keys: Pin request_key_auth payload in instantiate paths 2026-06-15 15:19:13 +03:00
kunit linux_kselftest-kunit-7.2-rc1 2026-06-16 16:33:57 +05:30
kvm Merge branch kvm-arm64/vgic-v5-PPI-fixes into kvmarm-master/next 2026-06-12 09:08:31 +01:00
linux BPF fixes: 2026-07-17 12:55:24 -07:00
math-emu
media media: v4l2-fwnode: Fix subdev owner overwritten in v4l2_async_register_subdev_sensor() 2026-06-05 10:28:03 +03:00
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net sctp: fix auth_hmacs array size in struct sctp_cookie 2026-07-17 12:27:53 +02:00
pcmcia Replace <linux/mod_devicetable.h> by more specific <linux/device-id/*.h> (headers) 2026-07-03 07:38:16 +02:00
ras
rdma RDMA v7.2 merge window 2026-06-18 08:16:21 -07:00
rv rv: Prevent task migration while handling per-CPU events 2026-06-03 12:33:25 +02:00
scsi scsi: core: wake eh reliably when using scsi_schedule_eh 2026-07-12 22:21:22 -04:00
soc soc/tegra: pmc: Fixes for v7.2 2026-07-10 14:40:52 +02:00
sound Replace <linux/mod_devicetable.h> by more specific <linux/device-id/*.h> (headers) 2026-07-03 07:38:16 +02:00
target
trace This adds support for manual client session reset in CephFS, allowing 2026-06-26 16:15:53 -07:00
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ufs Merge branch 7.1/scsi-fixes into 7.2/scsi-staging 2026-06-15 21:01:30 -04:00
vdso futex: Provide infrastructure to plug the non contended robust futex unlock race 2026-06-03 11:38:52 +02:00
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xen xen: Replace __ASSEMBLY__ with __ASSEMBLER__ in header files 2026-07-01 09:49:52 +02:00
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