linux/drivers/cpufreq
Jie Zhan 997c021abc cpufreq: CPPC: Update FIE arch_freq_scale in ticks for non-PCC regs
Currently, the CPPC Frequency Invariance Engine (FIE) is invoked from the
scheduler tick but defers the update of arch_freq_scale to a separate
thread because cppc_get_perf_ctrs() would sleep if the CPC regs are in PCC.

However, this deferred update mechanism is unnecessary and introduces extra
overhead for non-PCC register spaces (e.g. System Memory or FFH), where
accessing the regs won't sleep and can be safely performed from the tick
context.

Furthermore, with the CPPC FIE registered, it throws repeated warnings of
"cppc_scale_freq_workfn: failed to read perf counters" on our platform with
the CPC regs in System Memory and a power-down idle state enabled.  That's
because the remote CPU can be in a power-down idle state, and reading its
perf counters returns 0.  Moving the FIE handling back to the scheduler
tick process makes the CPU handle its own perf counters, so it won't be
idle and the issue would be inherently solved.

To address the above issues, update arch_freq_scale directly in ticks for
non-PCC regs and keep the deferred update mechanism for PCC regs.

Reviewed-by: Lifeng Zheng <zhenglifeng1@huawei.com>
Reviewed-by: Pierre Gondois <pierre.gondois@arm.com>
Signed-off-by: Jie Zhan <zhanjie9@hisilicon.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2026-01-27 11:21:23 +05:30
..
acpi-cpufreq.c cpufreq: ACPI: Replace udelay() with usleep_range() 2025-11-20 21:50:08 +01:00
airoha-cpufreq.c cpufreq: airoha: Add support for AN7583 SoC 2025-08-11 12:19:20 +05:30
amd-pstate-trace.c cpufreq: amd-pstate: Add trace for AMD P-State module 2021-12-30 18:51:39 +01:00
amd-pstate-trace.h cpufreq/amd-pstate: Move all EPP tracing into *_update_perf and *_set_epp functions 2025-03-06 13:01:25 -06:00
amd-pstate-ut.c Power management updates for 6.16-rc1 2025-05-27 16:48:47 -07:00
amd-pstate.c cpufreq/amd-pstate: Call cppc_set_auto_sel() only for online CPUs 2025-11-10 23:35:20 -06:00
amd-pstate.h amd-pstate-ut: Reset amd-pstate driver mode after running selftests 2025-05-05 12:07:42 -05:00
amd_freq_sensitivity.c x86/msr: Rename 'rdmsrl_safe()' to 'rdmsrq_safe()' 2025-04-10 11:58:38 +02:00
apple-soc-cpufreq.c cpufreq: apple-soc: Fix null-ptr-deref in apple_soc_cpufreq_get_rate() 2025-04-10 10:07:32 +05:30
armada-8k-cpufreq.c cpufreq: armada-8k: Fix off by one in armada_8k_cpufreq_free_table() 2025-07-02 12:08:16 +05:30
armada-37xx-cpufreq.c cpufreq: armada-37xx: use max() to calculate target_vm 2025-08-11 12:19:29 +05:30
bmips-cpufreq.c cpufreq: bmips: Stop setting cpufreq_driver->attr field 2025-02-07 09:45:11 +05:30
brcmstb-avs-cpufreq.c cpufreq: brcmstb-avs: Use scope-based cleanup helper 2025-08-29 11:28:27 +05:30
cppc_cpufreq.c cpufreq: CPPC: Update FIE arch_freq_scale in ticks for non-PCC regs 2026-01-27 11:21:23 +05:30
cpufreq-dt-platdev.c cpufreq: Add Tegra186 and Tegra194 to cpufreq-dt-platdev blocklist 2026-01-27 11:21:22 +05:30
cpufreq-dt.c cpufreq: Make drivers using CPUFREQ_ETERNAL specify transition latency 2025-10-01 13:56:24 +02:00
cpufreq-dt.h cpufreq: dt: Add register helper 2025-07-09 13:41:33 +05:30
cpufreq-nforce2.c cpufreq: nforce2: fix reference count leak in nforce2 2025-10-28 10:28:13 +05:30
cpufreq.c cpufreq: Replace deprecated strcpy() in cpufreq_unregister_governor() 2025-10-20 21:25:36 +02:00
cpufreq_conservative.c cpufreq: conservative: Replace sscanf() with kstrtouint() 2025-09-10 12:20:10 +02:00
cpufreq_governor.c cpufreq: governor: Fix negative 'idle_time' handling in dbs_update() 2025-02-20 20:27:19 +01:00
cpufreq_governor.h cpufreq: governor: Use kobject release() method to free dbs_data 2022-04-13 15:22:41 +02:00
cpufreq_governor_attr_set.c cpufreq: Move to_gov_attr_set() to cpufreq.h 2022-02-04 19:22:34 +01:00
cpufreq_ondemand.c cpufreq: ondemand: Update the efficient idle check for Intel extended Families 2025-09-10 12:25:08 +02:00
cpufreq_ondemand.h cpufreq: ondemand: Update the efficient idle check for Intel extended Families 2025-09-10 12:25:08 +02:00
cpufreq_performance.c cpufreq: Introduce CPUFREQ_GOV_STRICT_TARGET 2020-11-10 18:31:17 +01:00
cpufreq_powersave.c cpufreq: Introduce CPUFREQ_GOV_STRICT_TARGET 2020-11-10 18:31:17 +01:00
cpufreq_stats.c cpufreq: stats: Fix buffer overflow detection in trans_stats() 2023-10-24 22:02:06 +02:00
cpufreq_userspace.c cpufreq: userspace: set CPUFREQ_GOV_STRICT_TARGET flag 2025-06-18 21:33:01 +02:00
davinci-cpufreq.c cpufreq: davinci: Stop setting cpufreq_driver->attr field 2025-02-07 09:45:12 +05:30
e_powersaver.c x86/msr: Rename 'wrmsrl()' to 'wrmsrq()' 2025-04-10 11:58:33 +02:00
elanfreq.c x86/msr: Add explicit includes of <asm/msr.h> 2025-05-02 10:23:47 +02:00
freq_table.c cpufreq: Replace pointer subtraction with iteration macro 2025-09-23 17:16:56 +02:00
gx-suspmod.c cpufreq: Avoid creating excessively large stack frames 2020-01-27 10:33:33 +01:00
highbank-cpufreq.c cpufreq: Add __init annotation to module init funcs 2022-09-26 11:15:04 +05:30
imx-cpufreq-dt.c cpufreq: Switch back to struct platform_driver::remove() 2024-10-28 12:24:39 +01:00
imx6q-cpufreq.c cpufreq: Make drivers using CPUFREQ_ETERNAL specify transition latency 2025-10-01 13:56:24 +02:00
intel_pstate.c cpufreq: intel_pstate: Eliminate some code duplication 2025-11-18 15:51:31 +01:00
Kconfig cpufreq: Add Rust-based cpufreq-dt driver 2025-05-20 11:21:11 +05:30
Kconfig.arm cpufreq: tegra124: Allow building as a module 2025-07-09 13:41:58 +05:30
Kconfig.powerpc cpufreq: ppc_cbe: Remove powerpc Cell driver 2025-02-26 21:15:09 +05:30
Kconfig.x86 cpufreq: Introduce an optional cpuinfo_avg_freq sysfs entry 2025-02-17 18:09:31 +00:00
kirkwood-cpufreq.c cpufreq: kirkwood: Stop setting cpufreq_driver->attr field 2025-02-07 09:45:12 +05:30
longhaul.c cpufreq/longhaul: handle NULL policy in longhaul_exit 2025-09-01 10:50:28 +05:30
longhaul.h
longrun.c cpufreq: Convert to new X86 CPU match macros 2020-03-24 21:31:27 +01:00
loongson2_cpufreq.c cpufreq: loongson: Stop setting cpufreq_driver->attr field 2025-02-07 09:45:12 +05:30
loongson3_cpufreq.c cpufreq: loongson: Set .set_boost directly 2025-02-07 09:45:15 +05:30
Makefile PM: cpufreq: powernv/tracing: Move powernv_throttle trace event 2025-07-21 16:40:56 -04:00
mediatek-cpufreq-hw.c cpufreq: Make drivers using CPUFREQ_ETERNAL specify transition latency 2025-10-01 13:56:24 +02:00
mediatek-cpufreq.c cpufreq: mediatek: Simplify with of_machine_get_match_data() 2025-11-26 19:42:21 -06:00
mvebu-cpufreq.c cpufreq: Init cpufreq only for present CPUs 2025-03-17 11:29:18 +05:30
omap-cpufreq.c cpufreq: omap: Stop setting cpufreq_driver->attr field 2025-02-07 09:45:12 +05:30
p4-clockmod.c cpufreq: p4: Stop setting cpufreq_driver->attr field 2025-02-07 09:45:12 +05:30
pasemi-cpufreq.c cpufreq: pasemi: Stop setting cpufreq_driver->attr field 2025-02-07 09:45:12 +05:30
pcc-cpufreq.c cpufreq: Switch back to struct platform_driver::remove() 2024-10-28 12:24:39 +01:00
pmac32-cpufreq.c cpufreq: pmac: Stop setting cpufreq_driver->attr field 2025-02-07 09:45:13 +05:30
pmac64-cpufreq.c cpufreq: pmac: Stop setting cpufreq_driver->attr field 2025-02-07 09:45:13 +05:30
powernow-k6.c cpufreq: powernow: Stop setting cpufreq_driver->attr field 2025-02-07 09:45:13 +05:30
powernow-k7.c x86/msr: Rename 'wrmsrl()' to 'wrmsrq()' 2025-04-10 11:58:33 +02:00
powernow-k7.h
powernow-k8.c powernow: use pr_info_once 2025-05-11 17:54:05 -07:00
powernow-k8.h
powernv-cpufreq.c PM: cpufreq: powernv/tracing: Move powernv_throttle trace event 2025-07-21 16:40:56 -04:00
powernv-trace.h PM: cpufreq: powernv/tracing: Move powernv_throttle trace event 2025-07-21 16:40:56 -04:00
pxa2xx-cpufreq.c cpufreq: pxa3: move clk register access to clk driver 2022-05-07 22:55:49 +02:00
pxa3xx-cpufreq.c cpufreq: pxa3: move clk register access to clk driver 2022-05-07 22:55:49 +02:00
qcom-cpufreq-hw.c cpufreq: Init cpufreq only for present CPUs 2025-03-17 11:29:18 +05:30
qcom-cpufreq-nvmem.c cpufreq: qcom-nvmem: add sentinel to qcom_cpufreq_ipq806x_match_list 2026-01-27 11:21:22 +05:30
qoriq-cpufreq.c cpufreq: qoriq: Stop setting cpufreq_driver->attr field 2025-02-07 09:45:13 +05:30
raspberrypi-cpufreq.c cpufreq: Switch back to struct platform_driver::remove() 2024-10-28 12:24:39 +01:00
rcpufreq_dt.rs rust: cpufreq: replace kernel::c_str! with C-Strings 2026-01-27 11:21:22 +05:30
s3c64xx-cpufreq.c cpufreq: s3c64xx: Fix compilation warning 2025-01-23 20:47:32 +01:00
s5pv210-cpufreq.c cpufreq: s5pv210: fix refcount leak 2025-10-23 12:10:11 +05:30
sa1110-cpufreq.c ARM: sa1100: remove unused board files 2023-01-12 10:53:12 +01:00
sc520_freq.c x86/msr: Add explicit includes of <asm/msr.h> 2025-05-02 10:23:47 +02:00
scmi-cpufreq.c cpufreq: Make drivers using CPUFREQ_ETERNAL specify transition latency 2025-10-01 13:56:24 +02:00
scpi-cpufreq.c cpufreq: Make drivers using CPUFREQ_ETERNAL specify transition latency 2025-10-01 13:56:24 +02:00
sh-cpufreq.c cpufreq: Drop redundant freq_table parameter 2025-09-05 20:16:55 +02:00
sparc-us2e-cpufreq.c cpufreq: sparc: change kzalloc to kcalloc 2024-12-24 09:48:58 +05:30
sparc-us3-cpufreq.c cpufreq: sparc: change kzalloc to kcalloc 2024-12-24 09:48:58 +05:30
spear-cpufreq.c cpufreq: Make drivers using CPUFREQ_ETERNAL specify transition latency 2025-10-01 13:56:24 +02:00
speedstep-centrino.c cpufreq: speedstep: Stop setting cpufreq_driver->attr field 2025-02-07 09:45:14 +05:30
speedstep-ich.c cpufreq: speedstep: Stop setting cpufreq_driver->attr field 2025-02-07 09:45:14 +05:30
speedstep-lib.c cpufreq: speedstep-lib: Use int type to store negative error codes 2025-09-05 20:28:46 +02:00
speedstep-lib.h cpufreq: speedstep-lib: Use int type to store negative error codes 2025-09-05 20:28:46 +02:00
speedstep-smi.c cpufreq: speedstep: Stop setting cpufreq_driver->attr field 2025-02-07 09:45:14 +05:30
sti-cpufreq.c cpufreq: Use of_property_present() 2024-08-07 12:11:45 +05:30
sun50i-cpufreq-nvmem.c cpufreq: sun50i: Simplify with of_machine_device_match() 2025-11-26 19:42:30 -06:00
tegra20-cpufreq.c Devicetree updates for v6.4, part 2: 2023-04-27 10:09:05 -07:00
tegra124-cpufreq.c drivers: cpufreq: add Tegra114 support 2025-07-15 08:37:35 +05:30
tegra186-cpufreq.c cpufreq: tegra186: add OPP support and set bandwidth 2025-10-23 12:10:11 +05:30
tegra194-cpufreq.c cpufreq: tegra194: add WQ_PERCPU to alloc_workqueue users 2025-11-10 16:18:48 +05:30
ti-cpufreq.c cpufreq: ti: Allow all silicon revisions to support OPPs 2025-08-22 12:24:13 +05:30
vexpress-spc-cpufreq.c cpufreq: vexpress: Stop setting cpufreq_driver->attr field 2025-02-07 09:45:14 +05:30
virtual-cpufreq.c cpufreq: Drop redundant freq_table parameter 2025-09-05 20:16:55 +02:00