diff options
Diffstat (limited to 'arch/arm64/kernel/topology.c')
| -rw-r--r-- | arch/arm64/kernel/topology.c | 136 |
1 files changed, 110 insertions, 26 deletions
diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c index 2a9b69fdabc9..c8308befdb1e 100644 --- a/arch/arm64/kernel/topology.c +++ b/arch/arm64/kernel/topology.c @@ -124,6 +124,12 @@ int __init parse_acpi_topology(void) #endif #ifdef CONFIG_ARM64_AMU_EXTN +#define read_corecnt() read_sysreg_s(SYS_AMEVCNTR0_CORE_EL0) +#define read_constcnt() read_sysreg_s(SYS_AMEVCNTR0_CONST_EL0) +#else +#define read_corecnt() (0UL) +#define read_constcnt() (0UL) +#endif #undef pr_fmt #define pr_fmt(fmt) "AMU: " fmt @@ -133,54 +139,58 @@ static DEFINE_PER_CPU(u64, arch_const_cycles_prev); static DEFINE_PER_CPU(u64, arch_core_cycles_prev); static cpumask_var_t amu_fie_cpus; -/* Initialize counter reference per-cpu variables for the current CPU */ -void init_cpu_freq_invariance_counters(void) +void update_freq_counters_refs(void) { - this_cpu_write(arch_core_cycles_prev, - read_sysreg_s(SYS_AMEVCNTR0_CORE_EL0)); - this_cpu_write(arch_const_cycles_prev, - read_sysreg_s(SYS_AMEVCNTR0_CONST_EL0)); + this_cpu_write(arch_core_cycles_prev, read_corecnt()); + this_cpu_write(arch_const_cycles_prev, read_constcnt()); } -static int validate_cpu_freq_invariance_counters(int cpu) +static inline bool freq_counters_valid(int cpu) { - u64 max_freq_hz, ratio; + 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 -EINVAL; + return false; } if (unlikely(!per_cpu(arch_const_cycles_prev, cpu) || !per_cpu(arch_core_cycles_prev, cpu))) { pr_debug("CPU%d: cycle counters are not enabled.\n", cpu); - return -EINVAL; + return false; } - /* Convert maximum frequency from KHz to Hz and validate */ - max_freq_hz = cpufreq_get_hw_max_freq(cpu) * 1000; - if (unlikely(!max_freq_hz)) { - pr_debug("CPU%d: invalid maximum frequency.\n", cpu); + return true; +} + +static int freq_inv_set_max_ratio(int cpu, u64 max_rate, u64 ref_rate) +{ + u64 ratio; + + if (unlikely(!max_rate || !ref_rate)) { + pr_debug("CPU%d: invalid maximum or reference frequency.\n", + cpu); return -EINVAL; } /* * Pre-compute the fixed ratio between the frequency of the constant - * counter and the maximum frequency of the CPU. + * reference counter and the maximum frequency of the CPU. * - * const_freq - * arch_max_freq_scale = ---------------- * SCHED_CAPACITY_SCALE² - * cpuinfo_max_freq + * ref_rate + * arch_max_freq_scale = ---------- * SCHED_CAPACITY_SCALE² + * max_rate * * We use a factor of 2 * SCHED_CAPACITY_SHIFT -> SCHED_CAPACITY_SCALE² * in order to ensure a good resolution for arch_max_freq_scale for - * very low arch timer frequencies (down to the KHz range which should + * very low reference frequencies (down to the KHz range which should * be unlikely). */ - ratio = (u64)arch_timer_get_rate() << (2 * SCHED_CAPACITY_SHIFT); - ratio = div64_u64(ratio, max_freq_hz); + ratio = ref_rate << (2 * SCHED_CAPACITY_SHIFT); + ratio = div64_u64(ratio, max_rate); if (!ratio) { - WARN_ONCE(1, "System timer frequency too low.\n"); + WARN_ONCE(1, "Reference frequency too low.\n"); return -EINVAL; } @@ -228,8 +238,12 @@ static int __init init_amu_fie(void) } for_each_present_cpu(cpu) { - if (validate_cpu_freq_invariance_counters(cpu)) + if (!freq_counters_valid(cpu) || + freq_inv_set_max_ratio(cpu, + cpufreq_get_hw_max_freq(cpu) * 1000, + arch_timer_get_rate())) continue; + cpumask_set_cpu(cpu, valid_cpus); have_policy |= enable_policy_freq_counters(cpu, valid_cpus); } @@ -290,11 +304,14 @@ void topology_scale_freq_tick(void) if (!cpumask_test_cpu(cpu, amu_fie_cpus)) return; - const_cnt = read_sysreg_s(SYS_AMEVCNTR0_CONST_EL0); - core_cnt = read_sysreg_s(SYS_AMEVCNTR0_CORE_EL0); prev_const_cnt = this_cpu_read(arch_const_cycles_prev); prev_core_cnt = this_cpu_read(arch_core_cycles_prev); + update_freq_counters_refs(); + + const_cnt = this_cpu_read(arch_const_cycles_prev); + core_cnt = this_cpu_read(arch_core_cycles_prev); + if (unlikely(core_cnt <= prev_core_cnt || const_cnt <= prev_const_cnt)) goto store_and_exit; @@ -319,4 +336,71 @@ store_and_exit: this_cpu_write(arch_core_cycles_prev, core_cnt); this_cpu_write(arch_const_cycles_prev, const_cnt); } -#endif /* CONFIG_ARM64_AMU_EXTN */ + +#ifdef CONFIG_ACPI_CPPC_LIB +#include <acpi/cppc_acpi.h> + +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) +{ + /* + * Abort call on counterless CPU or when interrupts are + * disabled - can lead to deadlock in smp sync call. + */ + if (!cpu_has_amu_feat(cpu)) + return -EOPNOTSUPP; + + if (WARN_ON_ONCE(irqs_disabled())) + return -EPERM; + + 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 */ |