diff --git a/sys/x86/x86/tsc.c b/sys/x86/x86/tsc.c index 024800077e86..e821246ae293 100644 --- a/sys/x86/x86/tsc.c +++ b/sys/x86/x86/tsc.c @@ -1,953 +1,975 @@ /*- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD * * Copyright (c) 1998-2003 Poul-Henning Kamp * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include __FBSDID("$FreeBSD$"); #include "opt_clock.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "cpufreq_if.h" uint64_t tsc_freq; int tsc_is_invariant; int tsc_perf_stat; static int tsc_early_calib_exact; static eventhandler_tag tsc_levels_tag, tsc_pre_tag, tsc_post_tag; SYSCTL_INT(_kern_timecounter, OID_AUTO, invariant_tsc, CTLFLAG_RDTUN, &tsc_is_invariant, 0, "Indicates whether the TSC is P-state invariant"); #ifdef SMP int smp_tsc; SYSCTL_INT(_kern_timecounter, OID_AUTO, smp_tsc, CTLFLAG_RDTUN, &smp_tsc, 0, "Indicates whether the TSC is safe to use in SMP mode"); int smp_tsc_adjust = 0; SYSCTL_INT(_kern_timecounter, OID_AUTO, smp_tsc_adjust, CTLFLAG_RDTUN, &smp_tsc_adjust, 0, "Try to adjust TSC on APs to match BSP"); #endif static int tsc_shift = 1; SYSCTL_INT(_kern_timecounter, OID_AUTO, tsc_shift, CTLFLAG_RDTUN, &tsc_shift, 0, "Shift to pre-apply for the maximum TSC frequency"); static int tsc_disabled; SYSCTL_INT(_machdep, OID_AUTO, disable_tsc, CTLFLAG_RDTUN, &tsc_disabled, 0, "Disable x86 Time Stamp Counter"); static int tsc_skip_calibration; SYSCTL_INT(_machdep, OID_AUTO, disable_tsc_calibration, CTLFLAG_RDTUN, &tsc_skip_calibration, 0, "Disable early TSC frequency calibration"); static void tsc_freq_changed(void *arg, const struct cf_level *level, int status); static void tsc_freq_changing(void *arg, const struct cf_level *level, int *status); static u_int tsc_get_timecount(struct timecounter *tc); static inline u_int tsc_get_timecount_low(struct timecounter *tc); static u_int tsc_get_timecount_lfence(struct timecounter *tc); static u_int tsc_get_timecount_low_lfence(struct timecounter *tc); static u_int tsc_get_timecount_mfence(struct timecounter *tc); static u_int tsc_get_timecount_low_mfence(struct timecounter *tc); static u_int tscp_get_timecount(struct timecounter *tc); static u_int tscp_get_timecount_low(struct timecounter *tc); static void tsc_levels_changed(void *arg, int unit); static uint32_t x86_tsc_vdso_timehands(struct vdso_timehands *vdso_th, struct timecounter *tc); #ifdef COMPAT_FREEBSD32 static uint32_t x86_tsc_vdso_timehands32(struct vdso_timehands32 *vdso_th32, struct timecounter *tc); #endif static struct timecounter tsc_timecounter = { .tc_get_timecount = tsc_get_timecount, .tc_counter_mask = ~0u, .tc_name = "TSC", .tc_quality = 800, /* adjusted in code */ .tc_fill_vdso_timehands = x86_tsc_vdso_timehands, #ifdef COMPAT_FREEBSD32 .tc_fill_vdso_timehands32 = x86_tsc_vdso_timehands32, #endif }; static int tsc_freq_cpuid_vm(void) { u_int regs[4]; if (vm_guest == VM_GUEST_NO) return (false); if (hv_high < 0x40000010) return (false); do_cpuid(0x40000010, regs); tsc_freq = (uint64_t)(regs[0]) * 1000; tsc_early_calib_exact = 1; return (true); } static void tsc_freq_vmware(void) { u_int regs[4]; vmware_hvcall(VMW_HVCMD_GETHZ, regs); if (regs[1] != UINT_MAX) tsc_freq = regs[0] | ((uint64_t)regs[1] << 32); tsc_early_calib_exact = 1; } /* * Calculate TSC frequency using information from the CPUID leaf 0x15 'Time * Stamp Counter and Nominal Core Crystal Clock'. If leaf 0x15 is not * functional, as it is on Skylake/Kabylake, try 0x16 'Processor Frequency * Information'. Leaf 0x16 is described in the SDM as informational only, but * we can use this value until late calibration is complete. */ static bool tsc_freq_cpuid(uint64_t *res) { u_int regs[4]; if (cpu_high < 0x15) return (false); do_cpuid(0x15, regs); if (regs[0] != 0 && regs[1] != 0 && regs[2] != 0) { *res = (uint64_t)regs[2] * regs[1] / regs[0]; return (true); } if (cpu_high < 0x16) return (false); do_cpuid(0x16, regs); if (regs[0] != 0) { *res = (uint64_t)regs[0] * 1000000; return (true); } return (false); } static bool tsc_freq_intel_brand(uint64_t *res) { char brand[48]; u_int regs[4]; uint64_t freq; char *p; u_int i; /* * Intel Processor Identification and the CPUID Instruction * Application Note 485. * http://www.intel.com/assets/pdf/appnote/241618.pdf */ if (cpu_exthigh >= 0x80000004) { p = brand; for (i = 0x80000002; i < 0x80000005; i++) { do_cpuid(i, regs); memcpy(p, regs, sizeof(regs)); p += sizeof(regs); } p = NULL; for (i = 0; i < sizeof(brand) - 1; i++) if (brand[i] == 'H' && brand[i + 1] == 'z') p = brand + i; if (p != NULL) { p -= 5; switch (p[4]) { case 'M': i = 1; break; case 'G': i = 1000; break; case 'T': i = 1000000; break; default: return (false); } #define C2D(c) ((c) - '0') if (p[1] == '.') { freq = C2D(p[0]) * 1000; freq += C2D(p[2]) * 100; freq += C2D(p[3]) * 10; freq *= i * 1000; } else { freq = C2D(p[0]) * 1000; freq += C2D(p[1]) * 100; freq += C2D(p[2]) * 10; freq += C2D(p[3]); freq *= i * 1000000; } #undef C2D *res = freq; return (true); } } return (false); } static void -tsc_freq_8254(uint64_t *res) +tsc_freq_tc(uint64_t *res) { uint64_t tsc1, tsc2; int64_t overhead; int count, i; overhead = 0; for (i = 0, count = 8; i < count; i++) { tsc1 = rdtsc_ordered(); DELAY(0); tsc2 = rdtsc_ordered(); if (i > 0) overhead += tsc2 - tsc1; } overhead /= count; tsc1 = rdtsc_ordered(); DELAY(100000); tsc2 = rdtsc_ordered(); tsc_freq = (tsc2 - tsc1 - overhead) * 10; } +/* + * Try to determine the TSC frequency using CPUID or hypercalls. If successful, + * this lets use the TSC for early DELAY() calls instead of the 8254 timer, + * which may be unreliable or entirely absent on contemporary systems. However, + * avoid calibrating using the 8254 here so as to give hypervisors a chance to + * register a timecounter that can be used instead. + */ static void -probe_tsc_freq(void) +probe_tsc_freq_early(void) { #ifdef __i386__ /* The TSC is known to be broken on certain CPUs. */ switch (cpu_vendor_id) { case CPU_VENDOR_AMD: switch (cpu_id & 0xFF0) { case 0x500: /* K5 Model 0 */ tsc_disabled = 1; return; } break; case CPU_VENDOR_CENTAUR: switch (cpu_id & 0xff0) { case 0x540: /* * http://www.centtech.com/c6_data_sheet.pdf * * I-12 RDTSC may return incoherent values in EDX:EAX * I-13 RDTSC hangs when certain event counters are used */ tsc_disabled = 1; return; } break; case CPU_VENDOR_NSC: switch (cpu_id & 0xff0) { case 0x540: if ((cpu_id & CPUID_STEPPING) == 0) { tsc_disabled = 1; return; } break; } break; } #endif switch (cpu_vendor_id) { case CPU_VENDOR_AMD: case CPU_VENDOR_HYGON: if ((amd_pminfo & AMDPM_TSC_INVARIANT) != 0 || (vm_guest == VM_GUEST_NO && CPUID_TO_FAMILY(cpu_id) >= 0x10)) tsc_is_invariant = 1; if (cpu_feature & CPUID_SSE2) { tsc_timecounter.tc_get_timecount = tsc_get_timecount_mfence; } break; case CPU_VENDOR_INTEL: if ((amd_pminfo & AMDPM_TSC_INVARIANT) != 0 || (vm_guest == VM_GUEST_NO && ((CPUID_TO_FAMILY(cpu_id) == 0x6 && CPUID_TO_MODEL(cpu_id) >= 0xe) || (CPUID_TO_FAMILY(cpu_id) == 0xf && CPUID_TO_MODEL(cpu_id) >= 0x3)))) tsc_is_invariant = 1; if (cpu_feature & CPUID_SSE2) { tsc_timecounter.tc_get_timecount = tsc_get_timecount_lfence; } break; case CPU_VENDOR_CENTAUR: if (vm_guest == VM_GUEST_NO && CPUID_TO_FAMILY(cpu_id) == 0x6 && CPUID_TO_MODEL(cpu_id) >= 0xf && (rdmsr(0x1203) & 0x100000000ULL) == 0) tsc_is_invariant = 1; if (cpu_feature & CPUID_SSE2) { tsc_timecounter.tc_get_timecount = tsc_get_timecount_lfence; } break; } if (tsc_freq_cpuid_vm()) { if (bootverbose) printf( "Early TSC frequency %juHz derived from hypervisor CPUID\n", (uintmax_t)tsc_freq); } else if (vm_guest == VM_GUEST_VMWARE) { tsc_freq_vmware(); if (bootverbose) printf( "Early TSC frequency %juHz derived from VMWare hypercall\n", (uintmax_t)tsc_freq); } else if (tsc_freq_cpuid(&tsc_freq)) { /* * If possible, use the value obtained from CPUID as the initial * frequency. This will be refined later during boot but is * good enough for now. The 8254 PIT is not functional on some * newer platforms anyway, so don't delay our boot for what * might be a garbage result. Late calibration is required if * the initial frequency was obtained from CPUID.16H, as the * derived value may be off by as much as 1%. */ if (bootverbose) printf("Early TSC frequency %juHz derived from CPUID\n", (uintmax_t)tsc_freq); - } else if (tsc_skip_calibration) { + } +} + +/* + * If we were unable to determine the TSC frequency via CPU registers, try + * to calibrate against a known clock. + */ +static void +probe_tsc_freq_late(void) +{ + if (tsc_freq != 0) + return; + + if (tsc_skip_calibration) { /* * Try to parse the brand string to obtain the nominal TSC * frequency. */ if (cpu_vendor_id == CPU_VENDOR_INTEL && tsc_freq_intel_brand(&tsc_freq)) { if (bootverbose) printf( "Early TSC frequency %juHz derived from brand string\n", (uintmax_t)tsc_freq); } else { tsc_disabled = 1; } } else { /* - * Calibrate against the 8254 PIT. This estimate will be - * refined later in tsc_calib(). + * Calibrate against a timecounter or the 8254 PIT. This + * estimate will be refined later in tsc_calib(). */ - tsc_freq_8254(&tsc_freq); + tsc_freq_tc(&tsc_freq); if (bootverbose) printf( "Early TSC frequency %juHz calibrated from 8254 PIT\n", (uintmax_t)tsc_freq); } +} + +void +start_TSC(void) +{ + if ((cpu_feature & CPUID_TSC) == 0 || tsc_disabled) + return; + + probe_tsc_freq_late(); if (cpu_power_ecx & CPUID_PERF_STAT) { /* * XXX Some emulators expose host CPUID without actual support * for these MSRs. We must test whether they really work. */ wrmsr(MSR_MPERF, 0); wrmsr(MSR_APERF, 0); DELAY(10); if (rdmsr(MSR_MPERF) > 0 && rdmsr(MSR_APERF) > 0) tsc_perf_stat = 1; } -} - -void -start_TSC(void) -{ - if ((cpu_feature & CPUID_TSC) == 0 || tsc_disabled) - return; /* * Inform CPU accounting about our boot-time clock rate. This will * be updated if someone loads a cpufreq driver after boot that * discovers a new max frequency. * * The frequency may also be updated after late calibration is complete; * however, we register the TSC as the ticker now to avoid switching * counters after much of the kernel has already booted and potentially * sampled the CPU clock. */ if (tsc_freq != 0) set_cputicker(rdtsc, tsc_freq, !tsc_is_invariant); if (tsc_is_invariant) return; /* Register to find out about changes in CPU frequency. */ tsc_pre_tag = EVENTHANDLER_REGISTER(cpufreq_pre_change, tsc_freq_changing, NULL, EVENTHANDLER_PRI_FIRST); tsc_post_tag = EVENTHANDLER_REGISTER(cpufreq_post_change, tsc_freq_changed, NULL, EVENTHANDLER_PRI_FIRST); tsc_levels_tag = EVENTHANDLER_REGISTER(cpufreq_levels_changed, tsc_levels_changed, NULL, EVENTHANDLER_PRI_ANY); } #ifdef SMP /* * RDTSC is not a serializing instruction, and does not drain * instruction stream, so we need to drain the stream before executing * it. It could be fixed by use of RDTSCP, except the instruction is * not available everywhere. * * Use CPUID for draining in the boot-time SMP constistency test. The * timecounters use MFENCE for AMD CPUs, and LFENCE for others (Intel * and VIA) when SSE2 is present, and nothing on older machines which * also do not issue RDTSC prematurely. There, testing for SSE2 and * vendor is too cumbersome, and we learn about TSC presence from CPUID. * * Do not use do_cpuid(), since we do not need CPUID results, which * have to be written into memory with do_cpuid(). */ #define TSC_READ(x) \ static void \ tsc_read_##x(void *arg) \ { \ uint64_t *tsc = arg; \ u_int cpu = PCPU_GET(cpuid); \ \ __asm __volatile("cpuid" : : : "eax", "ebx", "ecx", "edx"); \ tsc[cpu * 3 + x] = rdtsc(); \ } TSC_READ(0) TSC_READ(1) TSC_READ(2) #undef TSC_READ #define N 1000 static void comp_smp_tsc(void *arg) { uint64_t *tsc; int64_t d1, d2; u_int cpu = PCPU_GET(cpuid); u_int i, j, size; size = (mp_maxid + 1) * 3; for (i = 0, tsc = arg; i < N; i++, tsc += size) CPU_FOREACH(j) { if (j == cpu) continue; d1 = tsc[cpu * 3 + 1] - tsc[j * 3]; d2 = tsc[cpu * 3 + 2] - tsc[j * 3 + 1]; if (d1 <= 0 || d2 <= 0) { smp_tsc = 0; return; } } } static void adj_smp_tsc(void *arg) { uint64_t *tsc; int64_t d, min, max; u_int cpu = PCPU_GET(cpuid); u_int first, i, size; first = CPU_FIRST(); if (cpu == first) return; min = INT64_MIN; max = INT64_MAX; size = (mp_maxid + 1) * 3; for (i = 0, tsc = arg; i < N; i++, tsc += size) { d = tsc[first * 3] - tsc[cpu * 3 + 1]; if (d > min) min = d; d = tsc[first * 3 + 1] - tsc[cpu * 3 + 2]; if (d > min) min = d; d = tsc[first * 3 + 1] - tsc[cpu * 3]; if (d < max) max = d; d = tsc[first * 3 + 2] - tsc[cpu * 3 + 1]; if (d < max) max = d; } if (min > max) return; d = min / 2 + max / 2; __asm __volatile ( "movl $0x10, %%ecx\n\t" "rdmsr\n\t" "addl %%edi, %%eax\n\t" "adcl %%esi, %%edx\n\t" "wrmsr\n" : /* No output */ : "D" ((uint32_t)d), "S" ((uint32_t)(d >> 32)) : "ax", "cx", "dx", "cc" ); } static int test_tsc(int adj_max_count) { uint64_t *data, *tsc; u_int i, size, adj; if ((!smp_tsc && !tsc_is_invariant)) return (-100); /* * Misbehavior of TSC under VirtualBox has been observed. In * particular, threads doing small (~1 second) sleeps may miss their * wakeup and hang around in sleep state, causing hangs on shutdown. */ if (vm_guest == VM_GUEST_VBOX) return (0); size = (mp_maxid + 1) * 3; data = malloc(sizeof(*data) * size * N, M_TEMP, M_WAITOK); adj = 0; retry: for (i = 0, tsc = data; i < N; i++, tsc += size) smp_rendezvous(tsc_read_0, tsc_read_1, tsc_read_2, tsc); smp_tsc = 1; /* XXX */ smp_rendezvous(smp_no_rendezvous_barrier, comp_smp_tsc, smp_no_rendezvous_barrier, data); if (!smp_tsc && adj < adj_max_count) { adj++; smp_rendezvous(smp_no_rendezvous_barrier, adj_smp_tsc, smp_no_rendezvous_barrier, data); goto retry; } free(data, M_TEMP); if (bootverbose) printf("SMP: %sed TSC synchronization test%s\n", smp_tsc ? "pass" : "fail", adj > 0 ? " after adjustment" : ""); if (smp_tsc && tsc_is_invariant) { switch (cpu_vendor_id) { case CPU_VENDOR_AMD: case CPU_VENDOR_HYGON: /* * Processor Programming Reference (PPR) for AMD * Family 17h states that the TSC uses a common * reference for all sockets, cores and threads. */ if (CPUID_TO_FAMILY(cpu_id) >= 0x17) return (1000); /* * Starting with Family 15h processors, TSC clock * source is in the north bridge. Check whether * we have a single-socket/multi-core platform. * XXX Need more work for complex cases. */ if (CPUID_TO_FAMILY(cpu_id) < 0x15 || (amd_feature2 & AMDID2_CMP) == 0 || smp_cpus > (cpu_procinfo2 & AMDID_CMP_CORES) + 1) break; return (1000); case CPU_VENDOR_INTEL: /* * XXX Assume Intel platforms have synchronized TSCs. */ return (1000); } return (800); } return (-100); } #undef N #endif /* SMP */ static void init_TSC_tc(void) { uint64_t max_freq; int shift; if ((cpu_feature & CPUID_TSC) == 0 || tsc_disabled) return; /* * Limit timecounter frequency to fit in an int and prevent it from * overflowing too fast. */ max_freq = UINT_MAX; /* * Intel CPUs without a C-state invariant TSC can stop the TSC * in either C2 or C3. Disable use of C2 and C3 while using * the TSC as the timecounter. The timecounter can be changed * to enable C2 and C3. * * Note that the TSC is used as the cputicker for computing * thread runtime regardless of the timecounter setting, so * using an alternate timecounter and enabling C2 or C3 can * result incorrect runtimes for kernel idle threads (but not * for any non-idle threads). */ if (cpu_vendor_id == CPU_VENDOR_INTEL && (amd_pminfo & AMDPM_TSC_INVARIANT) == 0) { tsc_timecounter.tc_flags |= TC_FLAGS_C2STOP; if (bootverbose) printf("TSC timecounter disables C2 and C3.\n"); } /* * We can not use the TSC in SMP mode unless the TSCs on all CPUs * are synchronized. If the user is sure that the system has * synchronized TSCs, set kern.timecounter.smp_tsc tunable to a * non-zero value. The TSC seems unreliable in virtualized SMP * environments, so it is set to a negative quality in those cases. */ #ifdef SMP if (mp_ncpus > 1) tsc_timecounter.tc_quality = test_tsc(smp_tsc_adjust); else #endif /* SMP */ if (tsc_is_invariant) tsc_timecounter.tc_quality = 1000; max_freq >>= tsc_shift; for (shift = 0; shift <= 31 && (tsc_freq >> shift) > max_freq; shift++) ; /* * Timecounter implementation selection, top to bottom: * - If RDTSCP is available, use RDTSCP. * - If fence instructions are provided (SSE2), use LFENCE;RDTSC * on Intel, and MFENCE;RDTSC on AMD. * - For really old CPUs, just use RDTSC. */ if ((amd_feature & AMDID_RDTSCP) != 0) { tsc_timecounter.tc_get_timecount = shift > 0 ? tscp_get_timecount_low : tscp_get_timecount; } else if ((cpu_feature & CPUID_SSE2) != 0 && mp_ncpus > 1) { if (cpu_vendor_id == CPU_VENDOR_AMD || cpu_vendor_id == CPU_VENDOR_HYGON) { tsc_timecounter.tc_get_timecount = shift > 0 ? tsc_get_timecount_low_mfence : tsc_get_timecount_mfence; } else { tsc_timecounter.tc_get_timecount = shift > 0 ? tsc_get_timecount_low_lfence : tsc_get_timecount_lfence; } } else { tsc_timecounter.tc_get_timecount = shift > 0 ? tsc_get_timecount_low : tsc_get_timecount; } if (shift > 0) { tsc_timecounter.tc_name = "TSC-low"; if (bootverbose) printf("TSC timecounter discards lower %d bit(s)\n", shift); } if (tsc_freq != 0) { tsc_timecounter.tc_frequency = tsc_freq >> shift; tsc_timecounter.tc_priv = (void *)(intptr_t)shift; /* * Timecounter registration is deferred until after late * calibration is finished. */ } } SYSINIT(tsc_tc, SI_SUB_SMP, SI_ORDER_ANY, init_TSC_tc, NULL); static void tsc_update_freq(uint64_t new_freq) { atomic_store_rel_64(&tsc_freq, new_freq); atomic_store_rel_64(&tsc_timecounter.tc_frequency, new_freq >> (int)(intptr_t)tsc_timecounter.tc_priv); } void tsc_init(void) { if ((cpu_feature & CPUID_TSC) == 0 || tsc_disabled) return; - probe_tsc_freq(); + probe_tsc_freq_early(); } /* * Perform late calibration of the TSC frequency once ACPI-based timecounters * are available. At this point timehands are not set up, so we read the * highest-quality timecounter directly rather than using (s)binuptime(). */ void tsc_calibrate(void) { uint64_t freq; if (tsc_disabled) return; if (tsc_early_calib_exact) goto calibrated; fpu_kern_enter(curthread, NULL, FPU_KERN_NOCTX); freq = clockcalib(rdtsc_ordered, "TSC"); fpu_kern_leave(curthread, NULL); tsc_update_freq(freq); calibrated: tc_init(&tsc_timecounter); set_cputicker(rdtsc, tsc_freq, !tsc_is_invariant); } void resume_TSC(void) { #ifdef SMP int quality; /* If TSC was not good on boot, it is unlikely to become good now. */ if (tsc_timecounter.tc_quality < 0) return; /* Nothing to do with UP. */ if (mp_ncpus < 2) return; /* * If TSC was good, a single synchronization should be enough, * but honour smp_tsc_adjust if it's set. */ quality = test_tsc(MAX(smp_tsc_adjust, 1)); if (quality != tsc_timecounter.tc_quality) { printf("TSC timecounter quality changed: %d -> %d\n", tsc_timecounter.tc_quality, quality); tsc_timecounter.tc_quality = quality; } #endif /* SMP */ } /* * When cpufreq levels change, find out about the (new) max frequency. We * use this to update CPU accounting in case it got a lower estimate at boot. */ static void tsc_levels_changed(void *arg, int unit) { device_t cf_dev; struct cf_level *levels; int count, error; uint64_t max_freq; /* Only use values from the first CPU, assuming all are equal. */ if (unit != 0) return; /* Find the appropriate cpufreq device instance. */ cf_dev = devclass_get_device(devclass_find("cpufreq"), unit); if (cf_dev == NULL) { printf("tsc_levels_changed() called but no cpufreq device?\n"); return; } /* Get settings from the device and find the max frequency. */ count = 64; levels = malloc(count * sizeof(*levels), M_TEMP, M_NOWAIT); if (levels == NULL) return; error = CPUFREQ_LEVELS(cf_dev, levels, &count); if (error == 0 && count != 0) { max_freq = (uint64_t)levels[0].total_set.freq * 1000000; set_cputicker(rdtsc, max_freq, 1); } else printf("tsc_levels_changed: no max freq found\n"); free(levels, M_TEMP); } /* * If the TSC timecounter is in use, veto the pending change. It may be * possible in the future to handle a dynamically-changing timecounter rate. */ static void tsc_freq_changing(void *arg, const struct cf_level *level, int *status) { if (*status != 0 || timecounter != &tsc_timecounter) return; printf("timecounter TSC must not be in use when " "changing frequencies; change denied\n"); *status = EBUSY; } /* Update TSC freq with the value indicated by the caller. */ static void tsc_freq_changed(void *arg, const struct cf_level *level, int status) { uint64_t freq; /* If there was an error during the transition, don't do anything. */ if (tsc_disabled || status != 0) return; /* Total setting for this level gives the new frequency in MHz. */ freq = (uint64_t)level->total_set.freq * 1000000; tsc_update_freq(freq); } static int sysctl_machdep_tsc_freq(SYSCTL_HANDLER_ARGS) { int error; uint64_t freq; freq = atomic_load_acq_64(&tsc_freq); if (freq == 0) return (EOPNOTSUPP); error = sysctl_handle_64(oidp, &freq, 0, req); if (error == 0 && req->newptr != NULL) tsc_update_freq(freq); return (error); } SYSCTL_PROC(_machdep, OID_AUTO, tsc_freq, CTLTYPE_U64 | CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 0, sysctl_machdep_tsc_freq, "QU", "Time Stamp Counter frequency"); static u_int tsc_get_timecount(struct timecounter *tc __unused) { return (rdtsc32()); } static u_int tscp_get_timecount(struct timecounter *tc __unused) { return (rdtscp32()); } static inline u_int tsc_get_timecount_low(struct timecounter *tc) { uint32_t rv; __asm __volatile("rdtsc; shrd %%cl, %%edx, %0" : "=a" (rv) : "c" ((int)(intptr_t)tc->tc_priv) : "edx"); return (rv); } static u_int tscp_get_timecount_low(struct timecounter *tc) { uint32_t rv; __asm __volatile("rdtscp; movl %1, %%ecx; shrd %%cl, %%edx, %0" : "=&a" (rv) : "m" (tc->tc_priv) : "ecx", "edx"); return (rv); } static u_int tsc_get_timecount_lfence(struct timecounter *tc __unused) { lfence(); return (rdtsc32()); } static u_int tsc_get_timecount_low_lfence(struct timecounter *tc) { lfence(); return (tsc_get_timecount_low(tc)); } static u_int tsc_get_timecount_mfence(struct timecounter *tc __unused) { mfence(); return (rdtsc32()); } static u_int tsc_get_timecount_low_mfence(struct timecounter *tc) { mfence(); return (tsc_get_timecount_low(tc)); } static uint32_t x86_tsc_vdso_timehands(struct vdso_timehands *vdso_th, struct timecounter *tc) { vdso_th->th_algo = VDSO_TH_ALGO_X86_TSC; vdso_th->th_x86_shift = (int)(intptr_t)tc->tc_priv; vdso_th->th_x86_hpet_idx = 0xffffffff; vdso_th->th_x86_pvc_last_systime = 0; vdso_th->th_x86_pvc_stable_mask = 0; bzero(vdso_th->th_res, sizeof(vdso_th->th_res)); return (1); } #ifdef COMPAT_FREEBSD32 static uint32_t x86_tsc_vdso_timehands32(struct vdso_timehands32 *vdso_th32, struct timecounter *tc) { vdso_th32->th_algo = VDSO_TH_ALGO_X86_TSC; vdso_th32->th_x86_shift = (int)(intptr_t)tc->tc_priv; vdso_th32->th_x86_hpet_idx = 0xffffffff; vdso_th32->th_x86_pvc_last_systime = 0; vdso_th32->th_x86_pvc_stable_mask = 0; bzero(vdso_th32->th_res, sizeof(vdso_th32->th_res)); return (1); } #endif