diff options
| author | Jeremy Linton <jeremy.linton@arm.com> | 2022-09-12 15:37:22 -0500 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2022-09-24 18:43:46 +0200 |
| commit | ae2df912d1a557a3548be83da20851ac55f42ab3 (patch) | |
| tree | 2e7a5615eb34e9034e0579a404bc3f8df30596a3 /include/acpi/cppc_acpi.h | |
| parent | a2a9d1850060e5d995136561d76e81d61414f076 (diff) | |
ACPI: CPPC: Disable FIE if registers in PCC regions
PCC regions utilize a mailbox to set/retrieve register values used by
the CPPC code. This is fine as long as the operations are
infrequent. With the FIE code enabled though the overhead can range
from 2-11% of system CPU overhead (ex: as measured by top) on Arm
based machines.
So, before enabling FIE assure none of the registers used by
cppc_get_perf_ctrs() are in the PCC region. Finally, add a module
parameter which can override the PCC region detection at boot or
module reload.
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Ionela Voinescu <ionela.voinescu@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'include/acpi/cppc_acpi.h')
| -rw-r--r-- | include/acpi/cppc_acpi.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/include/acpi/cppc_acpi.h b/include/acpi/cppc_acpi.h index f73d357ecdf5..c5614444031f 100644 --- a/include/acpi/cppc_acpi.h +++ b/include/acpi/cppc_acpi.h @@ -140,6 +140,7 @@ extern int cppc_get_perf_ctrs(int cpu, struct cppc_perf_fb_ctrs *perf_fb_ctrs); extern int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls); extern int cppc_set_enable(int cpu, bool enable); extern int cppc_get_perf_caps(int cpu, struct cppc_perf_caps *caps); +extern bool cppc_perf_ctrs_in_pcc(void); extern bool acpi_cpc_valid(void); extern bool cppc_allow_fast_switch(void); extern int acpi_get_psd_map(unsigned int cpu, struct cppc_cpudata *cpu_data); @@ -173,6 +174,10 @@ static inline int cppc_get_perf_caps(int cpu, struct cppc_perf_caps *caps) { return -ENOTSUPP; } +static inline bool cppc_perf_ctrs_in_pcc(void) +{ + return false; +} static inline bool acpi_cpc_valid(void) { return false; |