diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index 751bd9d3376b..f5b44ac354dc 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -772,6 +772,9 @@ static inline bool cpu_has_amu_feat(int cpu) } #endif +/* Get a cpu that supports the Activity Monitors Unit (AMU) */ +extern int get_cpu_with_amu_feat(void); + static inline unsigned int get_vmid_bits(u64 mmfr1) { int vmid_bits; diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 1142970e985b..6b08ae74ad0a 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -1526,6 +1526,11 @@ bool cpu_has_amu_feat(int cpu) return cpumask_test_cpu(cpu, &amu_cpus); } +int get_cpu_with_amu_feat(void) +{ + return cpumask_any(&amu_cpus); +} + static void cpu_amu_enable(struct arm64_cpu_capabilities const *cap) { if (has_cpuid_feature(cap, SCOPE_LOCAL_CPU)) { @@ -1554,6 +1559,11 @@ static bool has_amu(const struct arm64_cpu_capabilities *cap, return true; } +#else +int get_cpu_with_amu_feat(void) +{ + return nr_cpu_ids; +} #endif #ifdef CONFIG_ARM64_VHE diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c index b8cb16e3a2cc..7c9b6a0ecd6a 100644 --- a/arch/arm64/kernel/topology.c +++ b/arch/arm64/kernel/topology.c @@ -147,6 +147,9 @@ void update_freq_counters_refs(void) static inline bool freq_counters_valid(int cpu) { + if ((cpu >= nr_cpu_ids) || !cpumask_test_cpu(cpu, cpu_present_mask)) + return false; + if (!cpu_has_amu_feat(cpu)) { pr_debug("CPU%d: counters are not supported.\n", cpu); return false; @@ -323,3 +326,64 @@ void topology_scale_freq_tick(void) this_cpu_write(arch_core_cycles_prev, core_cnt); this_cpu_write(arch_const_cycles_prev, const_cnt); } + +#ifdef CONFIG_ACPI_CPPC_LIB +#include + +static void cpu_read_corecnt(void *val) +{ + *(u64 *)val = read_corecnt(); +} + +static void cpu_read_constcnt(void *val) +{ + *(u64 *)val = read_constcnt(); +} + +static inline +int counters_read_on_cpu(int cpu, smp_call_func_t func, u64 *val) +{ + if (!cpu_has_amu_feat(cpu)) + return -EOPNOTSUPP; + + smp_call_function_single(cpu, func, val, 1); + + return 0; +} + +/* + * Refer to drivers/acpi/cppc_acpi.c for the description of the functions + * below. + */ +bool cpc_ffh_supported(void) +{ + return freq_counters_valid(get_cpu_with_amu_feat()); +} + +int cpc_read_ffh(int cpu, struct cpc_reg *reg, u64 *val) +{ + int ret = -EOPNOTSUPP; + + switch ((u64)reg->address) { + case 0x0: + ret = counters_read_on_cpu(cpu, cpu_read_corecnt, val); + break; + case 0x1: + ret = counters_read_on_cpu(cpu, cpu_read_constcnt, val); + break; + } + + if (!ret) { + *val &= GENMASK_ULL(reg->bit_offset + reg->bit_width - 1, + reg->bit_offset); + *val >>= reg->bit_offset; + } + + return ret; +} + +int cpc_write_ffh(int cpunum, struct cpc_reg *reg, u64 val) +{ + return -EOPNOTSUPP; +} +#endif /* CONFIG_ACPI_CPPC_LIB */