diff options
| -rw-r--r-- | arch/arm64/kernel/topology.c | 92 |
1 files changed, 84 insertions, 8 deletions
diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c index b32f13358fbb..d28438f8b83f 100644 --- a/arch/arm64/kernel/topology.c +++ b/arch/arm64/kernel/topology.c @@ -373,6 +373,16 @@ core_initcall(init_amu_fie); #ifdef CONFIG_ACPI_CPPC_LIB #include <acpi/cppc_acpi.h> +struct amu_ffh_ctrs { + u64 corecnt; + u64 constcnt; +}; + +enum cpc_ffh_ctr_id { + CPC_FFH_CTR_CORE = 0x0, + CPC_FFH_CTR_CONST = 0x1, +}; + static void cpu_read_corecnt(void *val) { /* @@ -397,7 +407,7 @@ static void cpu_read_constcnt(void *val) } static inline -int counters_read_on_cpu(int cpu, smp_call_func_t func, u64 *val) +int counters_read_on_cpu(int cpu, smp_call_func_t func, void *val) { /* * Abort call on counterless CPU. @@ -447,24 +457,90 @@ bool cpc_ffh_supported(void) return true; } +static void amu_read_core_const_ctrs(void *val) +{ + struct amu_ffh_ctrs *ctrs = val; + + /* + * cpu_read_constcnt() incurs slight latency due to the + * ARM64_WORKAROUND_2457168 check. Read it first to minimize + * the sampling skew between the const and core counters. + */ + cpu_read_constcnt(&ctrs->constcnt); + cpu_read_corecnt(&ctrs->corecnt); +} + +static u64 cpc_ffh_extract_bits(const struct cpc_reg *reg, u64 val) +{ + val &= GENMASK_ULL(reg->bit_offset + reg->bit_width - 1, + reg->bit_offset); + val >>= reg->bit_offset; + + return val; +} + +static void cpc_ffh_ctr_value(const struct cpc_reg *reg, + const struct amu_ffh_ctrs *ctrs, u64 *val) +{ + switch ((u64)reg->address) { + case CPC_FFH_CTR_CORE: + *val = ctrs->corecnt; + break; + case CPC_FFH_CTR_CONST: + *val = ctrs->constcnt; + break; + } + + *val = cpc_ffh_extract_bits(reg, *val); +} + +static bool is_amu_ctr_reg(const struct cpc_reg *reg) +{ + return reg->address == CPC_FFH_CTR_CORE || + reg->address == CPC_FFH_CTR_CONST; +} + +int cpc_read_ffh_fb_ctrs(int cpu, struct cpc_reg *reg1, u64 *val1, + struct cpc_reg *reg2, u64 *val2) +{ + struct amu_ffh_ctrs ctrs; + int ret; + + if (!is_amu_ctr_reg(reg1) || !is_amu_ctr_reg(reg2)) + return -EINVAL; + + ret = counters_read_on_cpu(cpu, amu_read_core_const_ctrs, &ctrs); + if (ret) { + /* + * If AMU is unsupported (-EOPNOTSUPP), translate the error + * to -ENODEV. This explicitly tells the generic CPPC layer + * to abort immediately and avoid falling back to pointless + * single-counter reads. + */ + return ret == -EOPNOTSUPP ? -ENODEV : ret; + } + + cpc_ffh_ctr_value(reg1, &ctrs, val1); + cpc_ffh_ctr_value(reg2, &ctrs, val2); + + return 0; +} + int cpc_read_ffh(int cpu, struct cpc_reg *reg, u64 *val) { int ret = -EOPNOTSUPP; switch ((u64)reg->address) { - case 0x0: + case CPC_FFH_CTR_CORE: ret = counters_read_on_cpu(cpu, cpu_read_corecnt, val); break; - case 0x1: + case CPC_FFH_CTR_CONST: 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; - } + if (!ret) + *val = cpc_ffh_extract_bits(reg, *val); return ret; } |