diff options
Diffstat (limited to 'arch/x86/kernel/tsc.c')
| -rw-r--r-- | arch/x86/kernel/tsc.c | 145 |
1 files changed, 47 insertions, 98 deletions
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index 5a69a49acc96..87e749106dda 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -16,6 +16,7 @@ #include <linux/static_key.h> #include <linux/static_call.h> +#include <asm/cpuid/api.h> #include <asm/hpet.h> #include <asm/timer.h> #include <asm/vgtod.h> @@ -26,9 +27,12 @@ #include <asm/x86_init.h> #include <asm/geode.h> #include <asm/apic.h> -#include <asm/intel-family.h> +#include <asm/cpu_device_id.h> #include <asm/i8259.h> +#include <asm/msr.h> +#include <asm/topology.h> #include <asm/uv/uv.h> +#include <asm/sev.h> unsigned int __read_mostly cpu_khz; /* TSC clocks / usec, not used here */ EXPORT_SYMBOL(cpu_khz); @@ -44,15 +48,15 @@ EXPORT_SYMBOL(tsc_khz); static int __read_mostly tsc_unstable; static unsigned int __initdata tsc_early_khz; -static DEFINE_STATIC_KEY_FALSE(__use_tsc); +static DEFINE_STATIC_KEY_FALSE_RO(__use_tsc); int tsc_clocksource_reliable; static int __read_mostly tsc_force_recalibrate; -static u32 art_to_tsc_numerator; -static u32 art_to_tsc_denominator; -static u64 art_to_tsc_offset; +static struct clocksource_base art_base_clk = { + .id = CSID_X86_ART, +}; static bool have_art; struct cyc2ns { @@ -173,10 +177,11 @@ static void __set_cyc2ns_scale(unsigned long khz, int cpu, unsigned long long ts c2n = per_cpu_ptr(&cyc2ns, cpu); - raw_write_seqcount_latch(&c2n->seq); + write_seqcount_latch_begin(&c2n->seq); c2n->data[0] = data; - raw_write_seqcount_latch(&c2n->seq); + write_seqcount_latch(&c2n->seq); c2n->data[1] = data; + write_seqcount_latch_end(&c2n->seq); } static void set_cyc2ns_scale(unsigned long khz, int cpu, unsigned long long tsc_now) @@ -663,13 +668,13 @@ unsigned long native_calibrate_tsc(void) if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL) return 0; - if (boot_cpu_data.cpuid_level < 0x15) + if (boot_cpu_data.cpuid_level < CPUID_LEAF_TSC) return 0; eax_denominator = ebx_numerator = ecx_hz = edx = 0; /* CPUID 15H TSC/Crystal ratio, plus optionally Crystal Hz */ - cpuid(0x15, &eax_denominator, &ebx_numerator, &ecx_hz, &edx); + cpuid(CPUID_LEAF_TSC, &eax_denominator, &ebx_numerator, &ecx_hz, &edx); if (ebx_numerator == 0 || eax_denominator == 0) return 0; @@ -678,11 +683,11 @@ unsigned long native_calibrate_tsc(void) /* * Denverton SoCs don't report crystal clock, and also don't support - * CPUID.0x16 for the calculation below, so hardcode the 25MHz crystal - * clock. + * CPUID_LEAF_FREQ for the calculation below, so hardcode the 25MHz + * crystal clock. */ if (crystal_khz == 0 && - boot_cpu_data.x86_model == INTEL_FAM6_ATOM_GOLDMONT_D) + boot_cpu_data.x86_vfm == INTEL_ATOM_GOLDMONT_D) crystal_khz = 25000; /* @@ -698,10 +703,10 @@ unsigned long native_calibrate_tsc(void) * clock, but we can easily calculate it to a high degree of accuracy * by considering the crystal ratio and the CPU speed. */ - if (crystal_khz == 0 && boot_cpu_data.cpuid_level >= 0x16) { + if (crystal_khz == 0 && boot_cpu_data.cpuid_level >= CPUID_LEAF_FREQ) { unsigned int eax_base_mhz, ebx, ecx, edx; - cpuid(0x16, &eax_base_mhz, &ebx, &ecx, &edx); + cpuid(CPUID_LEAF_FREQ, &eax_base_mhz, &ebx, &ecx, &edx); crystal_khz = eax_base_mhz * 1000 * eax_denominator / ebx_numerator; } @@ -713,7 +718,7 @@ unsigned long native_calibrate_tsc(void) * For Atom SoCs TSC is the only reliable clocksource. * Mark TSC reliable so no watchdog on it. */ - if (boot_cpu_data.x86_model == INTEL_FAM6_ATOM_GOLDMONT) + if (boot_cpu_data.x86_vfm == INTEL_ATOM_GOLDMONT) setup_force_cpu_cap(X86_FEATURE_TSC_RELIABLE); #ifdef CONFIG_X86_LOCAL_APIC @@ -736,12 +741,12 @@ static unsigned long cpu_khz_from_cpuid(void) if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL) return 0; - if (boot_cpu_data.cpuid_level < 0x16) + if (boot_cpu_data.cpuid_level < CPUID_LEAF_FREQ) return 0; eax_base_mhz = ebx_max_mhz = ecx_bus_mhz = edx = 0; - cpuid(0x16, &eax_base_mhz, &ebx_max_mhz, &ecx_bus_mhz, &edx); + cpuid(CPUID_LEAF_FREQ, &eax_base_mhz, &ebx_max_mhz, &ecx_bus_mhz, &edx); return eax_base_mhz * 1000; } @@ -955,7 +960,7 @@ static unsigned long long cyc2ns_suspend; void tsc_save_sched_clock_state(void) { - if (!sched_clock_stable()) + if (!static_branch_likely(&__use_tsc) && !sched_clock_stable()) return; cyc2ns_suspend = sched_clock(); @@ -975,7 +980,7 @@ void tsc_restore_sched_clock_state(void) unsigned long flags; int cpu; - if (!sched_clock_stable()) + if (!static_branch_likely(&__use_tsc) && !sched_clock_stable()) return; local_irq_save(flags); @@ -1065,18 +1070,16 @@ core_initcall(cpufreq_register_tsc_scaling); #endif /* CONFIG_CPU_FREQ */ -#define ART_CPUID_LEAF (0x15) #define ART_MIN_DENOMINATOR (1) - /* * If ART is present detect the numerator:denominator to convert to TSC */ static void __init detect_art(void) { - unsigned int unused[2]; + unsigned int unused; - if (boot_cpu_data.cpuid_level < ART_CPUID_LEAF) + if (boot_cpu_data.cpuid_level < CPUID_LEAF_TSC) return; /* @@ -1089,13 +1092,14 @@ static void __init detect_art(void) tsc_async_resets) return; - cpuid(ART_CPUID_LEAF, &art_to_tsc_denominator, - &art_to_tsc_numerator, unused, unused+1); + cpuid(CPUID_LEAF_TSC, &art_base_clk.denominator, + &art_base_clk.numerator, &art_base_clk.freq_khz, &unused); - if (art_to_tsc_denominator < ART_MIN_DENOMINATOR) + art_base_clk.freq_khz /= KHZ; + if (art_base_clk.denominator < ART_MIN_DENOMINATOR) return; - rdmsrl(MSR_IA32_TSC_ADJUST, art_to_tsc_offset); + rdmsrq(MSR_IA32_TSC_ADJUST, art_base_clk.offset); /* Make this sticky over multiple CPU init calls */ setup_force_cpu_cap(X86_FEATURE_ART); @@ -1252,15 +1256,12 @@ static void __init check_system_tsc_reliable(void) * - TSC which does not stop in C-States * - the TSC_ADJUST register which allows to detect even minimal * modifications - * - not more than two sockets. As the number of sockets cannot be - * evaluated at the early boot stage where this has to be - * invoked, check the number of online memory nodes as a - * fallback solution which is an reasonable estimate. + * - not more than four packages */ if (boot_cpu_has(X86_FEATURE_CONSTANT_TSC) && boot_cpu_has(X86_FEATURE_NONSTOP_TSC) && boot_cpu_has(X86_FEATURE_TSC_ADJUST) && - nr_online_nodes <= 4) + topology_max_packages() <= 4) tsc_disable_clocksource_watchdog(); } @@ -1289,74 +1290,13 @@ int unsynchronized_tsc(void) */ if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL) { /* assume multi socket systems are not synchronized: */ - if (num_possible_cpus() > 1) + if (topology_max_packages() > 1) return 1; } return 0; } -/* - * Convert ART to TSC given numerator/denominator found in detect_art() - */ -struct system_counterval_t convert_art_to_tsc(u64 art) -{ - u64 tmp, res, rem; - - rem = do_div(art, art_to_tsc_denominator); - - res = art * art_to_tsc_numerator; - tmp = rem * art_to_tsc_numerator; - - do_div(tmp, art_to_tsc_denominator); - res += tmp + art_to_tsc_offset; - - return (struct system_counterval_t) { - .cs_id = have_art ? CSID_X86_TSC : CSID_GENERIC, - .cycles = res, - }; -} -EXPORT_SYMBOL(convert_art_to_tsc); - -/** - * convert_art_ns_to_tsc() - Convert ART in nanoseconds to TSC. - * @art_ns: ART (Always Running Timer) in unit of nanoseconds - * - * PTM requires all timestamps to be in units of nanoseconds. When user - * software requests a cross-timestamp, this function converts system timestamp - * to TSC. - * - * This is valid when CPU feature flag X86_FEATURE_TSC_KNOWN_FREQ is set - * indicating the tsc_khz is derived from CPUID[15H]. Drivers should check - * that this flag is set before conversion to TSC is attempted. - * - * Return: - * struct system_counterval_t - system counter value with the ID of the - * corresponding clocksource: - * cycles: System counter value - * cs_id: The clocksource ID for validating comparability - */ - -struct system_counterval_t convert_art_ns_to_tsc(u64 art_ns) -{ - u64 tmp, res, rem; - - rem = do_div(art_ns, USEC_PER_SEC); - - res = art_ns * tsc_khz; - tmp = rem * tsc_khz; - - do_div(tmp, USEC_PER_SEC); - res += tmp; - - return (struct system_counterval_t) { - .cs_id = have_art ? CSID_X86_TSC : CSID_GENERIC, - .cycles = res, - }; -} -EXPORT_SYMBOL(convert_art_ns_to_tsc); - - static void tsc_refine_calibration_work(struct work_struct *work); static DECLARE_DELAYED_WORK(tsc_irqwork, tsc_refine_calibration_work); /** @@ -1458,8 +1398,10 @@ out: if (tsc_unstable) goto unreg; - if (boot_cpu_has(X86_FEATURE_ART)) + if (boot_cpu_has(X86_FEATURE_ART)) { have_art = true; + clocksource_tsc.base = &art_base_clk; + } clocksource_register_khz(&clocksource_tsc, tsc_khz); unreg: clocksource_unregister(&clocksource_tsc_early); @@ -1484,8 +1426,10 @@ static int __init init_tsc_clocksource(void) * the refined calibration and directly register it as a clocksource. */ if (boot_cpu_has(X86_FEATURE_TSC_KNOWN_FREQ)) { - if (boot_cpu_has(X86_FEATURE_ART)) + if (boot_cpu_has(X86_FEATURE_ART)) { have_art = true; + clocksource_tsc.base = &art_base_clk; + } clocksource_register_khz(&clocksource_tsc, tsc_khz); clocksource_unregister(&clocksource_tsc_early); @@ -1509,10 +1453,12 @@ static bool __init determine_cpu_tsc_frequencies(bool early) if (early) { cpu_khz = x86_platform.calibrate_cpu(); - if (tsc_early_khz) + if (tsc_early_khz) { tsc_khz = tsc_early_khz; - else + } else { tsc_khz = x86_platform.calibrate_tsc(); + clocksource_tsc.freq_khz = tsc_khz; + } } else { /* We should not be here with non-native cpu calibration */ WARN_ON(x86_platform.calibrate_cpu != native_calibrate_cpu); @@ -1570,6 +1516,9 @@ void __init tsc_early_init(void) /* Don't change UV TSC multi-chassis synchronization */ if (is_early_uv_system()) return; + + snp_secure_tsc_init(); + if (!determine_cpu_tsc_frequencies(true)) return; tsc_enable_sched_clock(); |