diff options
| -rw-r--r-- | arch/x86/kernel/tsc.c | 94 |
1 files changed, 53 insertions, 41 deletions
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index 4cab2236169e..7ea0718a4c75 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -103,23 +103,6 @@ void cyc2ns_read_end(void) * -johnstul@us.ibm.com "math is hard, lets go shopping!" */ -static void cyc2ns_data_init(struct cyc2ns_data *data) -{ - data->cyc2ns_mul = 0; - data->cyc2ns_shift = 0; - data->cyc2ns_offset = 0; -} - -static void __init cyc2ns_init(int cpu) -{ - struct cyc2ns *c2n = &per_cpu(cyc2ns, cpu); - - cyc2ns_data_init(&c2n->data[0]); - cyc2ns_data_init(&c2n->data[1]); - - seqcount_init(&c2n->seq); -} - static inline unsigned long long cycles_2_ns(unsigned long long cyc) { struct cyc2ns_data data; @@ -135,18 +118,11 @@ static inline unsigned long long cycles_2_ns(unsigned long long cyc) return ns; } -static void set_cyc2ns_scale(unsigned long khz, int cpu, unsigned long long tsc_now) +static void __set_cyc2ns_scale(unsigned long khz, int cpu, unsigned long long tsc_now) { unsigned long long ns_now; struct cyc2ns_data data; struct cyc2ns *c2n; - unsigned long flags; - - local_irq_save(flags); - sched_clock_idle_sleep_event(); - - if (!khz) - goto done; ns_now = cycles_2_ns(tsc_now); @@ -178,13 +154,56 @@ static void set_cyc2ns_scale(unsigned long khz, int cpu, unsigned long long tsc_ c2n->data[0] = data; raw_write_seqcount_latch(&c2n->seq); c2n->data[1] = data; +} + +static void set_cyc2ns_scale(unsigned long khz, int cpu, unsigned long long tsc_now) +{ + unsigned long flags; + + local_irq_save(flags); + sched_clock_idle_sleep_event(); + + if (khz) + __set_cyc2ns_scale(khz, cpu, tsc_now); -done: sched_clock_idle_wakeup_event(); local_irq_restore(flags); } /* + * Initialize cyc2ns for boot cpu + */ +static void __init cyc2ns_init_boot_cpu(void) +{ + struct cyc2ns *c2n = this_cpu_ptr(&cyc2ns); + + seqcount_init(&c2n->seq); + __set_cyc2ns_scale(tsc_khz, smp_processor_id(), rdtsc()); +} + +/* + * Secondary CPUs do not run through cyc2ns_init(), so set up + * all the scale factors for all CPUs, assuming the same + * speed as the bootup CPU. (cpufreq notifiers will fix this + * up if their speed diverges) + */ +static void __init cyc2ns_init_secondary_cpus(void) +{ + unsigned int cpu, this_cpu = smp_processor_id(); + struct cyc2ns *c2n = this_cpu_ptr(&cyc2ns); + struct cyc2ns_data *data = c2n->data; + + for_each_possible_cpu(cpu) { + if (cpu != this_cpu) { + seqcount_init(&c2n->seq); + c2n = per_cpu_ptr(&cyc2ns, cpu); + c2n->data[0] = data[0]; + c2n->data[1] = data[1]; + } + } +} + +/* * Scheduler clock - returns current time in nanosec units. */ u64 native_sched_clock(void) @@ -1385,6 +1404,10 @@ void __init tsc_early_init(void) if (!determine_cpu_tsc_frequencies()) return; loops_per_jiffy = get_loops_per_jiffy(); + + /* Sanitize TSC ADJUST before cyc2ns gets initialized */ + tsc_store_and_check_tsc_adjust(true); + cyc2ns_init_boot_cpu(); } void __init tsc_init(void) @@ -1401,23 +1424,12 @@ void __init tsc_init(void) setup_clear_cpu_cap(X86_FEATURE_TSC_DEADLINE_TIMER); return; } + /* Sanitize TSC ADJUST before cyc2ns gets initialized */ + tsc_store_and_check_tsc_adjust(true); + cyc2ns_init_boot_cpu(); } - /* Sanitize TSC ADJUST before cyc2ns gets initialized */ - tsc_store_and_check_tsc_adjust(true); - - /* - * Secondary CPUs do not run through tsc_init(), so set up - * all the scale factors for all CPUs, assuming the same - * speed as the bootup CPU. (cpufreq notifiers will fix this - * up if their speed diverges) - */ - cyc = rdtsc(); - for_each_possible_cpu(cpu) { - cyc2ns_init(cpu); - set_cyc2ns_scale(tsc_khz, cpu, cyc); - } - + cyc2ns_init_secondary_cpus(); static_branch_enable(&__use_tsc); if (!no_sched_irq_time) |