diff options
Diffstat (limited to 'arch/powerpc/kernel/perf_event.c')
| -rw-r--r-- | arch/powerpc/kernel/perf_event.c | 1448 |
1 files changed, 0 insertions, 1448 deletions
diff --git a/arch/powerpc/kernel/perf_event.c b/arch/powerpc/kernel/perf_event.c deleted file mode 100644 index c2e27ed..0000000 --- a/arch/powerpc/kernel/perf_event.c +++ /dev/null @@ -1,1448 +0,0 @@ -/* - * Performance event support - powerpc architecture code - * - * Copyright 2008-2009 Paul Mackerras, IBM Corporation. - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation; either version - * 2 of the License, or (at your option) any later version. - */ -#include <linux/kernel.h> -#include <linux/sched.h> -#include <linux/perf_event.h> -#include <linux/percpu.h> -#include <linux/hardirq.h> -#include <asm/reg.h> -#include <asm/pmc.h> -#include <asm/machdep.h> -#include <asm/firmware.h> -#include <asm/ptrace.h> - -struct cpu_hw_events { - int n_events; - int n_percpu; - int disabled; - int n_added; - int n_limited; - u8 pmcs_enabled; - struct perf_event *event[MAX_HWEVENTS]; - u64 events[MAX_HWEVENTS]; - unsigned int flags[MAX_HWEVENTS]; - unsigned long mmcr[3]; - struct perf_event *limited_counter[MAX_LIMITED_HWCOUNTERS]; - u8 limited_hwidx[MAX_LIMITED_HWCOUNTERS]; - u64 alternatives[MAX_HWEVENTS][MAX_EVENT_ALTERNATIVES]; - unsigned long amasks[MAX_HWEVENTS][MAX_EVENT_ALTERNATIVES]; - unsigned long avalues[MAX_HWEVENTS][MAX_EVENT_ALTERNATIVES]; - - unsigned int group_flag; - int n_txn_start; -}; -DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events); - -struct power_pmu *ppmu; - -/* - * Normally, to ignore kernel events we set the FCS (freeze counters - * in supervisor mode) bit in MMCR0, but if the kernel runs with the - * hypervisor bit set in the MSR, or if we are running on a processor - * where the hypervisor bit is forced to 1 (as on Apple G5 processors), - * then we need to use the FCHV bit to ignore kernel events. - */ -static unsigned int freeze_events_kernel = MMCR0_FCS; - -/* - * 32-bit doesn't have MMCRA but does have an MMCR2, - * and a few other names are different. - */ -#ifdef CONFIG_PPC32 - -#define MMCR0_FCHV 0 -#define MMCR0_PMCjCE MMCR0_PMCnCE - -#define SPRN_MMCRA SPRN_MMCR2 -#define MMCRA_SAMPLE_ENABLE 0 - -static inline unsigned long perf_ip_adjust(struct pt_regs *regs) -{ - return 0; -} -static inline void perf_get_data_addr(struct pt_regs *regs, u64 *addrp) { } -static inline u32 perf_get_misc_flags(struct pt_regs *regs) -{ - return 0; -} -static inline void perf_read_regs(struct pt_regs *regs) { } -static inline int perf_intr_is_nmi(struct pt_regs *regs) -{ - return 0; -} - -#endif /* CONFIG_PPC32 */ - -/* - * Things that are specific to 64-bit implementations. - */ -#ifdef CONFIG_PPC64 - -static inline unsigned long perf_ip_adjust(struct pt_regs *regs) -{ - unsigned long mmcra = regs->dsisr; - - if ((mmcra & MMCRA_SAMPLE_ENABLE) && !(ppmu->flags & PPMU_ALT_SIPR)) { - unsigned long slot = (mmcra & MMCRA_SLOT) >> MMCRA_SLOT_SHIFT; - if (slot > 1) - return 4 * (slot - 1); - } - return 0; -} - -/* - * The user wants a data address recorded. - * If we're not doing instruction sampling, give them the SDAR - * (sampled data address). If we are doing instruction sampling, then - * only give them the SDAR if it corresponds to the instruction - * pointed to by SIAR; this is indicated by the [POWER6_]MMCRA_SDSYNC - * bit in MMCRA. - */ -static inline void perf_get_data_addr(struct pt_regs *regs, u64 *addrp) -{ - unsigned long mmcra = regs->dsisr; - unsigned long sdsync = (ppmu->flags & PPMU_ALT_SIPR) ? - POWER6_MMCRA_SDSYNC : MMCRA_SDSYNC; - - if (!(mmcra & MMCRA_SAMPLE_ENABLE) || (mmcra & sdsync)) - *addrp = mfspr(SPRN_SDAR); -} - -static inline u32 perf_get_misc_flags(struct pt_regs *regs) -{ - unsigned long mmcra = regs->dsisr; - unsigned long sihv = MMCRA_SIHV; - unsigned long sipr = MMCRA_SIPR; - - if (TRAP(regs) != 0xf00) - return 0; /* not a PMU interrupt */ - - if (ppmu->flags & PPMU_ALT_SIPR) { - sihv = POWER6_MMCRA_SIHV; - sipr = POWER6_MMCRA_SIPR; - } - - /* PR has priority over HV, so order below is important */ - if (mmcra & sipr) - return PERF_RECORD_MISC_USER; - if ((mmcra & sihv) && (freeze_events_kernel != MMCR0_FCHV)) - return PERF_RECORD_MISC_HYPERVISOR; - return PERF_RECORD_MISC_KERNEL; -} - -/* - * Overload regs->dsisr to store MMCRA so we only need to read it once - * on each interrupt. - */ -static inline void perf_read_regs(struct pt_regs *regs) -{ - regs->dsisr = mfspr(SPRN_MMCRA); -} - -/* - * If interrupts were soft-disabled when a PMU interrupt occurs, treat - * it as an NMI. - */ -static inline int perf_intr_is_nmi(struct pt_regs *regs) -{ - return !regs->softe; -} - -#endif /* CONFIG_PPC64 */ - -static void perf_event_interrupt(struct pt_regs *regs); - -void perf_event_print_debug(void) -{ -} - -/* - * Read one performance monitor counter (PMC). - */ -static unsigned long read_pmc(int idx) -{ - unsigned long val; - - switch (idx) { - case 1: - val = mfspr(SPRN_PMC1); - break; - case 2: - val = mfspr(SPRN_PMC2); - break; - case 3: - val = mfspr(SPRN_PMC3); - break; - case 4: - val = mfspr(SPRN_PMC4); - break; - case 5: - val = mfspr(SPRN_PMC5); - break; - case 6: - val = mfspr(SPRN_PMC6); - break; -#ifdef CONFIG_PPC64 - case 7: - val = mfspr(SPRN_PMC7); - break; - case 8: - val = mfspr(SPRN_PMC8); - break; -#endif /* CONFIG_PPC64 */ - default: - printk(KERN_ERR "oops trying to read PMC%d\n", idx); - val = 0; - } - return val; -} - -/* - * Write one PMC. - */ -static void write_pmc(int idx, unsigned long val) -{ - switch (idx) { - case 1: - mtspr(SPRN_PMC1, val); - break; - case 2: - mtspr(SPRN_PMC2, val); - break; - case 3: - mtspr(SPRN_PMC3, val); - break; - case 4: - mtspr(SPRN_PMC4, val); - break; - case 5: - mtspr(SPRN_PMC5, val); - break; - case 6: - mtspr(SPRN_PMC6, val); - break; -#ifdef CONFIG_PPC64 - case 7: - mtspr(SPRN_PMC7, val); - break; - case 8: - mtspr(SPRN_PMC8, val); - break; -#endif /* CONFIG_PPC64 */ - default: - printk(KERN_ERR "oops trying to write PMC%d\n", idx); - } -} - -/* - * Check if a set of events can all go on the PMU at once. - * If they can't, this will look at alternative codes for the events - * and see if any combination of alternative codes is feasible. - * The feasible set is returned in event_id[]. - */ -static int power_check_constraints(struct cpu_hw_events *cpuhw, - u64 event_id[], unsigned int cflags[], - int n_ev) -{ - unsigned long mask, value, nv; - unsigned long smasks[MAX_HWEVENTS], svalues[MAX_HWEVENTS]; - int n_alt[MAX_HWEVENTS], choice[MAX_HWEVENTS]; - int i, j; - unsigned long addf = ppmu->add_fields; - unsigned long tadd = ppmu->test_adder; - - if (n_ev > ppmu->n_counter) - return -1; - - /* First see if the events will go on as-is */ - for (i = 0; i < n_ev; ++i) { - if ((cflags[i] & PPMU_LIMITED_PMC_REQD) - && !ppmu->limited_pmc_event(event_id[i])) { - ppmu->get_alternatives(event_id[i], cflags[i], - cpuhw->alternatives[i]); - event_id[i] = cpuhw->alternatives[i][0]; - } - if (ppmu->get_constraint(event_id[i], &cpuhw->amasks[i][0], - &cpuhw->avalues[i][0])) - return -1; - } - value = mask = 0; - for (i = 0; i < n_ev; ++i) { - nv = (value | cpuhw->avalues[i][0]) + - (value & cpuhw->avalues[i][0] & addf); - if ((((nv + tadd) ^ value) & mask) != 0 || - (((nv + tadd) ^ cpuhw->avalues[i][0]) & - cpuhw->amasks[i][0]) != 0) - break; - value = nv; - mask |= cpuhw->amasks[i][0]; - } - if (i == n_ev) - return 0; /* all OK */ - - /* doesn't work, gather alternatives... */ - if (!ppmu->get_alternatives) - return -1; - for (i = 0; i < n_ev; ++i) { - choice[i] = 0; - n_alt[i] = ppmu->get_alternatives(event_id[i], cflags[i], - cpuhw->alternatives[i]); - for (j = 1; j < n_alt[i]; ++j) - ppmu->get_constraint(cpuhw->alternatives[i][j], - &cpuhw->amasks[i][j], - &cpuhw->avalues[i][j]); - } - - /* enumerate all possibilities and see if any will work */ - i = 0; - j = -1; - value = mask = nv = 0; - while (i < n_ev) { - if (j >= 0) { - /* we're backtracking, restore context */ - value = svalues[i]; - mask = smasks[i]; - j = choice[i]; - } - /* - * See if any alternative k for event_id i, - * where k > j, will satisfy the constraints. - */ - while (++j < n_alt[i]) { - nv = (value | cpuhw->avalues[i][j]) + - (value & cpuhw->avalues[i][j] & addf); - if ((((nv + tadd) ^ value) & mask) == 0 && - (((nv + tadd) ^ cpuhw->avalues[i][j]) - & cpuhw->amasks[i][j]) == 0) - break; - } - if (j >= n_alt[i]) { - /* - * No feasible alternative, backtrack - * to event_id i-1 and continue enumerating its - * alternatives from where we got up to. - */ - if (--i < 0) - return -1; - } else { - /* - * Found a feasible alternative for event_id i, - * remember where we got up to with this event_id, - * go on to the next event_id, and start with - * the first alternative for it. - */ - choice[i] = j; - svalues[i] = value; - smasks[i] = mask; - value = nv; - mask |= cpuhw->amasks[i][j]; - ++i; - j = -1; - } - } - - /* OK, we have a feasible combination, tell the caller the solution */ - for (i = 0; i < n_ev; ++i) - event_id[i] = cpuhw->alternatives[i][choice[i]]; - return 0; -} - -/* - * Check if newly-added events have consistent settings for - * exclude_{user,kernel,hv} with each other and any previously - * added events. - */ -static int check_excludes(struct perf_event **ctrs, unsigned int cflags[], - int n_prev, int n_new) -{ - int eu = 0, ek = 0, eh = 0; - int i, n, first; - struct perf_event *event; - - n = n_prev + n_new; - if (n <= 1) - return 0; - - first = 1; - for (i = 0; i < n; ++i) { - if (cflags[i] & PPMU_LIMITED_PMC_OK) { - cflags[i] &= ~PPMU_LIMITED_PMC_REQD; - continue; - } - event = ctrs[i]; - if (first) { - eu = event->attr.exclude_user; - ek = event->attr.exclude_kernel; - eh = event->attr.exclude_hv; - first = 0; - } else if (event->attr.exclude_user != eu || - event->attr.exclude_kernel != ek || - event->attr.exclude_hv != eh) { - return -EAGAIN; - } - } - - if (eu || ek || eh) - for (i = 0; i < n; ++i) - if (cflags[i] & PPMU_LIMITED_PMC_OK) - cflags[i] |= PPMU_LIMITED_PMC_REQD; - - return 0; -} - -static u64 check_and_compute_delta(u64 prev, u64 val) -{ - u64 delta = (val - prev) & 0xfffffffful; - - /* - * POWER7 can roll back counter values, if the new value is smaller - * than the previous value it will cause the delta and the counter to - * have bogus values unless we rolled a counter over. If a coutner is - * rolled back, it will be smaller, but within 256, which is the maximum - * number of events to rollback at once. If we dectect a rollback - * return 0. This can lead to a small lack of precision in the - * counters. - */ - if (prev > val && (prev - val) < 256) - delta = 0; - - return delta; -} - -static void power_pmu_read(struct perf_event *event) -{ - s64 val, delta, prev; - - if (event->hw.state & PERF_HES_STOPPED) - return; - - if (!event->hw.idx) - return; - /* - * Performance monitor interrupts come even when interrupts - * are soft-disabled, as long as interrupts are hard-enabled. - * Therefore we treat them like NMIs. - */ - do { - prev = local64_read(&event->hw.prev_count); - barrier(); - val = read_pmc(event->hw.idx); - delta = check_and_compute_delta(prev, val); - if (!delta) - return; - } while (local64_cmpxchg(&event->hw.prev_count, prev, val) != prev); - - local64_add(delta, &event->count); - local64_sub(delta, &event->hw.period_left); -} - -/* - * On some machines, PMC5 and PMC6 can't be written, don't respect - * the freeze conditions, and don't generate interrupts. This tells - * us if `event' is using such a PMC. - */ -static int is_limited_pmc(int pmcnum) -{ - return (ppmu->flags & PPMU_LIMITED_PMC5_6) - && (pmcnum == 5 || pmcnum == 6); -} - -static void freeze_limited_counters(struct cpu_hw_events *cpuhw, - unsigned long pmc5, unsigned long pmc6) -{ - struct perf_event *event; - u64 val, prev, delta; - int i; - - for (i = 0; i < cpuhw->n_limited; ++i) { - event = cpuhw->limited_counter[i]; - if (!event->hw.idx) - continue; - val = (event->hw.idx == 5) ? pmc5 : pmc6; - prev = local64_read(&event->hw.prev_count); - event->hw.idx = 0; - delta = check_and_compute_delta(prev, val); - if (delta) - local64_add(delta, &event->count); - } -} - -static void thaw_limited_counters(struct cpu_hw_events *cpuhw, - unsigned long pmc5, unsigned long pmc6) -{ - struct perf_event *event; - u64 val, prev; - int i; - - for (i = 0; i < cpuhw->n_limited; ++i) { - event = cpuhw->limited_counter[i]; - event->hw.idx = cpuhw->limited_hwidx[i]; - val = (event->hw.idx == 5) ? pmc5 : pmc6; - prev = local64_read(&event->hw.prev_count); - if (check_and_compute_delta(prev, val)) - local64_set(&event->hw.prev_count, val); - perf_event_update_userpage(event); - } -} - -/* - * Since limited events don't respect the freeze conditions, we - * have to read them immediately after freezing or unfreezing the - * other events. We try to keep the values from the limited - * events as consistent as possible by keeping the delay (in - * cycles and instructions) between freezing/unfreezing and reading - * the limited events as small and consistent as possible. - * Therefore, if any limited events are in use, we read them - * both, and always in the same order, to minimize variability, - * and do it inside the same asm that writes MMCR0. - */ -static void write_mmcr0(struct cpu_hw_events *cpuhw, unsigned long mmcr0) -{ - unsigned long pmc5, pmc6; - - if (!cpuhw->n_limited) { - mtspr(SPRN_MMCR0, mmcr0); - return; - } - - /* - * Write MMCR0, then read PMC5 and PMC6 immediately. - * To ensure we don't get a performance monitor interrupt - * between writing MMCR0 and freezing/thawing the limited - * events, we first write MMCR0 with the event overflow - * interrupt enable bits turned off. - */ - asm volatile("mtspr %3,%2; mfspr %0,%4; mfspr %1,%5" - : "=&r" (pmc5), "=&r" (pmc6) - : "r" (mmcr0 & ~(MMCR0_PMC1CE | MMCR0_PMCjCE)), - "i" (SPRN_MMCR0), - "i" (SPRN_PMC5), "i" (SPRN_PMC6)); - - if (mmcr0 & MMCR0_FC) - freeze_limited_counters(cpuhw, pmc5, pmc6); - else - thaw_limited_counters(cpuhw, pmc5, pmc6); - - /* - * Write the full MMCR0 including the event overflow interrupt - * enable bits, if necessary. - */ - if (mmcr0 & (MMCR0_PMC1CE | MMCR0_PMCjCE)) - mtspr(SPRN_MMCR0, mmcr0); -} - -/* - * Disable all events to prevent PMU interrupts and to allow - * events to be added or removed. - */ -static void power_pmu_disable(struct pmu *pmu) -{ - struct cpu_hw_events *cpuhw; - unsigned long flags; - - if (!ppmu) - return; - local_irq_save(flags); - cpuhw = &__get_cpu_var(cpu_hw_events); - - if (!cpuhw->disabled) { - cpuhw->disabled = 1; - cpuhw->n_added = 0; - - /* - * Check if we ever enabled the PMU on this cpu. - */ - if (!cpuhw->pmcs_enabled) { - ppc_enable_pmcs(); - cpuhw->pmcs_enabled = 1; - } - - /* - * Disable instruction sampling if it was enabled - */ - if (cpuhw->mmcr[2] & MMCRA_SAMPLE_ENABLE) { - mtspr(SPRN_MMCRA, - cpuhw->mmcr[2] & ~MMCRA_SAMPLE_ENABLE); - mb(); - } - - /* - * Set the 'freeze counters' bit. - * The barrier is to make sure the mtspr has been - * executed and the PMU has frozen the events - * before we return. - */ - write_mmcr0(cpuhw, mfspr(SPRN_MMCR0) | MMCR0_FC); - mb(); - } - local_irq_restore(flags); -} - -/* - * Re-enable all events if disable == 0. - * If we were previously disabled and events were added, then - * put the new config on the PMU. - */ -static void power_pmu_enable(struct pmu *pmu) -{ - struct perf_event *event; - struct cpu_hw_events *cpuhw; - unsigned long flags; - long i; - unsigned long val; - s64 left; - unsigned int hwc_index[MAX_HWEVENTS]; - int n_lim; - int idx; - - if (!ppmu) - return; - local_irq_save(flags); - cpuhw = &__get_cpu_var(cpu_hw_events); - if (!cpuhw->disabled) { - local_irq_restore(flags); - return; - } - cpuhw->disabled = 0; - - /* - * If we didn't change anything, or only removed events, - * no need to recalculate MMCR* settings and reset the PMCs. - * Just reenable the PMU with the current MMCR* settings - * (possibly updated for removal of events). - */ - if (!cpuhw->n_added) { - mtspr(SPRN_MMCRA, cpuhw->mmcr[2] & ~MMCRA_SAMPLE_ENABLE); - mtspr(SPRN_MMCR1, cpuhw->mmcr[1]); - if (cpuhw->n_events == 0) - ppc_set_pmu_inuse(0); - goto out_enable; - } - - /* - * Compute MMCR* values for the new set of events - */ - if (ppmu->compute_mmcr(cpuhw->events, cpuhw->n_events, hwc_index, - cpuhw->mmcr)) { - /* shouldn't ever get here */ - printk(KERN_ERR "oops compute_mmcr failed\n"); - goto out; - } - - /* - * Add in MMCR0 freeze bits corresponding to the - * attr.exclude_* bits for the first event. - * We have already checked that all events have the - * same values for these bits as the first event. - */ - event = cpuhw->event[0]; - if (event->attr.exclude_user) - cpuhw->mmcr[0] |= MMCR0_FCP; - if (event->attr.exclude_kernel) - cpuhw->mmcr[0] |= freeze_events_kernel; - if (event->attr.exclude_hv) - cpuhw->mmcr[0] |= MMCR0_FCHV; - - /* - * Write the new configuration to MMCR* with the freeze - * bit set and set the hardware events to their initial values. - * Then unfreeze the events. - */ - ppc_set_pmu_inuse(1); - mtspr(SPRN_MMCRA, cpuhw->mmcr[2] & ~MMCRA_SAMPLE_ENABLE); - mtspr(SPRN_MMCR1, cpuhw->mmcr[1]); - mtspr(SPRN_MMCR0, (cpuhw->mmcr[0] & ~(MMCR0_PMC1CE | MMCR0_PMCjCE)) - | MMCR0_FC); - - /* - * Read off any pre-existing events that need to move - * to another PMC. - */ - for (i = 0; i < cpuhw->n_events; ++i) { - event = cpuhw->event[i]; - if (event->hw.idx && event->hw.idx != hwc_index[i] + 1) { - power_pmu_read(event); - write_pmc(event->hw.idx, 0); - event->hw.idx = 0; - } - } - - /* - * Initialize the PMCs for all the new and moved events. - */ - cpuhw->n_limited = n_lim = 0; - for (i = 0; i < cpuhw->n_events; ++i) { - event = cpuhw->event[i]; - if (event->hw.idx) - continue; - idx = hwc_index[i] + 1; - if (is_limited_pmc(idx)) { - cpuhw->limited_counter[n_lim] = event; - cpuhw->limited_hwidx[n_lim] = idx; - ++n_lim; - continue; - } - val = 0; - if (event->hw.sample_period) { - left = local64_read(&event->hw.period_left); - if (left < 0x80000000L) - val = 0x80000000L - left; - } - local64_set(&event->hw.prev_count, val); - event->hw.idx = idx; - if (event->hw.state & PERF_HES_STOPPED) - val = 0; - write_pmc(idx, val); - perf_event_update_userpage(event); - } - cpuhw->n_limited = n_lim; - cpuhw->mmcr[0] |= MMCR0_PMXE | MMCR0_FCECE; - - out_enable: - mb(); - write_mmcr0(cpuhw, cpuhw->mmcr[0]); - - /* - * Enable instruction sampling if necessary - */ - if (cpuhw->mmcr[2] & MMCRA_SAMPLE_ENABLE) { - mb(); - mtspr(SPRN_MMCRA, cpuhw->mmcr[2]); - } - - out: - local_irq_restore(flags); -} - -static int collect_events(struct perf_event *group, int max_count, - struct perf_event *ctrs[], u64 *events, - unsigned int *flags) -{ - int n = 0; - struct perf_event *event; - - if (!is_software_event(group)) { - if (n >= max_count) - return -1; - ctrs[n] = group; - flags[n] = group->hw.event_base; - events[n++] = group->hw.config; - } - list_for_each_entry(event, &group->sibling_list, group_entry) { - if (!is_software_event(event) && - event->state != PERF_EVENT_STATE_OFF) { - if (n >= max_count) - return -1; - ctrs[n] = event; - flags[n] = event->hw.event_base; - events[n++] = event->hw.config; - } - } - return n; -} - -/* - * Add a event to the PMU. - * If all events are not already frozen, then we disable and - * re-enable the PMU in order to get hw_perf_enable to do the - * actual work of reconfiguring the PMU. - */ -static int power_pmu_add(struct perf_event *event, int ef_flags) -{ - struct cpu_hw_events *cpuhw; - unsigned long flags; - int n0; - int ret = -EAGAIN; - - local_irq_save(flags); - perf_pmu_disable(event->pmu); - - /* - * Add the event to the list (if there is room) - * and check whether the total set is still feasible. - */ - cpuhw = &__get_cpu_var(cpu_hw_events); - n0 = cpuhw->n_events; - if (n0 >= ppmu->n_counter) - goto out; - cpuhw->event[n0] = event; - cpuhw->events[n0] = event->hw.config; - cpuhw->flags[n0] = event->hw.event_base; - - if (!(ef_flags & PERF_EF_START)) - event->hw.state = PERF_HES_STOPPED | PERF_HES_UPTODATE; - - /* - * If group events scheduling transaction was started, - * skip the schedulability test here, it will be performed - * at commit time(->commit_txn) as a whole - */ - if (cpuhw->group_flag & PERF_EVENT_TXN) - goto nocheck; - - if (check_excludes(cpuhw->event, cpuhw->flags, n0, 1)) - goto out; - if (power_check_constraints(cpuhw, cpuhw->events, cpuhw->flags, n0 + 1)) - goto out; - event->hw.config = cpuhw->events[n0]; - -nocheck: - ++cpuhw->n_events; - ++cpuhw->n_added; - - ret = 0; - out: - perf_pmu_enable(event->pmu); - local_irq_restore(flags); - return ret; -} - -/* - * Remove a event from the PMU. - */ -static void power_pmu_del(struct perf_event *event, int ef_flags) -{ - struct cpu_hw_events *cpuhw; - long i; - unsigned long flags; - - local_irq_save(flags); - perf_pmu_disable(event->pmu); - - power_pmu_read(event); - - cpuhw = &__get_cpu_var(cpu_hw_events); - for (i = 0; i < cpuhw->n_events; ++i) { - if (event == cpuhw->event[i]) { - while (++i < cpuhw->n_events) { - cpuhw->event[i-1] = cpuhw->event[i]; - cpuhw->events[i-1] = cpuhw->events[i]; - cpuhw->flags[i-1] = cpuhw->flags[i]; - } - --cpuhw->n_events; - ppmu->disable_pmc(event->hw.idx - 1, cpuhw->mmcr); - if (event->hw.idx) { - write_pmc(event->hw.idx, 0); - event->hw.idx = 0; - } - perf_event_update_userpage(event); - break; - } - } - for (i = 0; i < cpuhw->n_limited; ++i) - if (event == cpuhw->limited_counter[i]) - break; - if (i < cpuhw->n_limited) { - while (++i < cpuhw->n_limited) { - cpuhw->limited_counter[i-1] = cpuhw->limited_counter[i]; - cpuhw->limited_hwidx[i-1] = cpuhw->limited_hwidx[i]; - } - --cpuhw->n_limited; - } - if (cpuhw->n_events == 0) { - /* disable exceptions if no events are running */ - cpuhw->mmcr[0] &= ~(MMCR0_PMXE | MMCR0_FCECE); - } - - perf_pmu_enable(event->pmu); - local_irq_restore(flags); -} - -/* - * POWER-PMU does not support disabling individual counters, hence - * program their cycle counter to their max value and ignore the interrupts. - */ - -static void power_pmu_start(struct perf_event *event, int ef_flags) -{ - unsigned long flags; - s64 left; - unsigned long val; - - if (!event->hw.idx || !event->hw.sample_period) - return; - - if (!(event->hw.state & PERF_HES_STOPPED)) - return; - - if (ef_flags & PERF_EF_RELOAD) - WARN_ON_ONCE(!(event->hw.state & PERF_HES_UPTODATE)); - - local_irq_save(flags); - perf_pmu_disable(event->pmu); - - event->hw.state = 0; - left = local64_read(&event->hw.period_left); - - val = 0; - if (left < 0x80000000L) - val = 0x80000000L - left; - - write_pmc(event->hw.idx, val); - - perf_event_update_userpage(event); - perf_pmu_enable(event->pmu); - local_irq_restore(flags); -} - -static void power_pmu_stop(struct perf_event *event, int ef_flags) -{ - unsigned long flags; - - if (!event->hw.idx || !event->hw.sample_period) - return; - - if (event->hw.state & PERF_HES_STOPPED) - return; - - local_irq_save(flags); - perf_pmu_disable(event->pmu); - - power_pmu_read(event); - event->hw.state |= PERF_HES_STOPPED | PERF_HES_UPTODATE; - write_pmc(event->hw.idx, 0); - - perf_event_update_userpage(event); - perf_pmu_enable(event->pmu); - local_irq_restore(flags); -} - -/* - * Start group events scheduling transaction - * Set the flag to make pmu::enable() not perform the - * schedulability test, it will be performed at commit time - */ -void power_pmu_start_txn(struct pmu *pmu) -{ - struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events); - - perf_pmu_disable(pmu); - cpuhw->group_flag |= PERF_EVENT_TXN; - cpuhw->n_txn_start = cpuhw->n_events; -} - -/* - * Stop group events scheduling transaction - * Clear the flag and pmu::enable() will perform the - * schedulability test. - */ -void power_pmu_cancel_txn(struct pmu *pmu) -{ - struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events); - - cpuhw->group_flag &= ~PERF_EVENT_TXN; - perf_pmu_enable(pmu); -} - -/* - * Commit group events scheduling transaction - * Perform the group schedulability test as a whole - * Return 0 if success - */ -int power_pmu_commit_txn(struct pmu *pmu) -{ - struct cpu_hw_events *cpuhw; - long i, n; - - if (!ppmu) - return -EAGAIN; - cpuhw = &__get_cpu_var(cpu_hw_events); - n = cpuhw->n_events; - if (check_excludes(cpuhw->event, cpuhw->flags, 0, n)) - return -EAGAIN; - i = power_check_constraints(cpuhw, cpuhw->events, cpuhw->flags, n); - if (i < 0) - return -EAGAIN; - - for (i = cpuhw->n_txn_start; i < n; ++i) - cpuhw->event[i]->hw.config = cpuhw->events[i]; - - cpuhw->group_flag &= ~PERF_EVENT_TXN; - perf_pmu_enable(pmu); - return 0; -} - -/* - * Return 1 if we might be able to put event on a limited PMC, - * or 0 if not. - * A event can only go on a limited PMC if it counts something - * that a limited PMC can count, doesn't require interrupts, and - * doesn't exclude any processor mode. - */ -static int can_go_on_limited_pmc(struct perf_event *event, u64 ev, - unsigned int flags) -{ - int n; - u64 alt[MAX_EVENT_ALTERNATIVES]; - - if (event->attr.exclude_user - || event->attr.exclude_kernel - || event->attr.exclude_hv - || event->attr.sample_period) - return 0; - - if (ppmu->limited_pmc_event(ev)) - return 1; - - /* - * The requested event_id isn't on a limited PMC already; - * see if any alternative code goes on a limited PMC. - */ - if (!ppmu->get_alternatives) - return 0; - - flags |= PPMU_LIMITED_PMC_OK | PPMU_LIMITED_PMC_REQD; - n = ppmu->get_alternatives(ev, flags, alt); - - return n > 0; -} - -/* - * Find an alternative event_id that goes on a normal PMC, if possible, - * and return the event_id code, or 0 if there is no such alternative. - * (Note: event_id code 0 is "don't count" on all machines.) - */ -static u64 normal_pmc_alternative(u64 ev, unsigned long flags) -{ - u64 alt[MAX_EVENT_ALTERNATIVES]; - int n; - - flags &= ~(PPMU_LIMITED_PMC_OK | PPMU_LIMITED_PMC_REQD); - n = ppmu->get_alternatives(ev, flags, alt); - if (!n) - return 0; - return alt[0]; -} - -/* Number of perf_events counting hardware events */ -static atomic_t num_events; -/* Used to avoid races in calling reserve/release_pmc_hardware */ -static DEFINE_MUTEX(pmc_reserve_mutex); - -/* - * Release the PMU if this is the last perf_event. - */ -static void hw_perf_event_destroy(struct perf_event *event) -{ - if (!atomic_add_unless(&num_events, -1, 1)) { - mutex_lock(&pmc_reserve_mutex); - if (atomic_dec_return(&num_events) == 0) - release_pmc_hardware(); - mutex_unlock(&pmc_reserve_mutex); - } -} - -/* - * Translate a generic cache event_id config to a raw event_id code. - */ -static int hw_perf_cache_event(u64 config, u64 *eventp) -{ - unsigned long type, op, result; - int ev; - - if (!ppmu->cache_events) - return -EINVAL; - - /* unpack config */ - type = config & 0xff; - op = (config >> 8) & 0xff; - result = (config >> 16) & 0xff; - - if (type >= PERF_COUNT_HW_CACHE_MAX || - op >= PERF_COUNT_HW_CACHE_OP_MAX || - result >= PERF_COUNT_HW_CACHE_RESULT_MAX) - return -EINVAL; - - ev = (*ppmu->cache_events)[type][op][result]; - if (ev == 0) - return -EOPNOTSUPP; - if (ev == -1) - return -EINVAL; - *eventp = ev; - return 0; -} - -static int power_pmu_event_init(struct perf_event *event) -{ - u64 ev; - unsigned long flags; - struct perf_event *ctrs[MAX_HWEVENTS]; - u64 events[MAX_HWEVENTS]; - unsigned int cflags[MAX_HWEVENTS]; - int n; - int err; - struct cpu_hw_events *cpuhw; - - if (!ppmu) - return -ENOENT; - - /* does not support taken branch sampling */ - if (has_branch_stack(event)) - return -EOPNOTSUPP; - - switch (event->attr.type) { - case PERF_TYPE_HARDWARE: - ev = event->attr.config; - if (ev >= ppmu->n_generic || ppmu->generic_events[ev] == 0) - return -EOPNOTSUPP; - ev = ppmu->generic_events[ev]; - break; - case PERF_TYPE_HW_CACHE: - err = hw_perf_cache_event(event->attr.config, &ev); - if (err) - return err; - break; - case PERF_TYPE_RAW: - ev = event->attr.config; - break; - default: - return -ENOENT; - } - - event->hw.config_base = ev; - event->hw.idx = 0; - - /* - * If we are not running on a hypervisor, force the - * exclude_hv bit to 0 so that we don't care what - * the user set it to. - */ - if (!firmware_has_feature(FW_FEATURE_LPAR)) - event->attr.exclude_hv = 0; - - /* - * If this is a per-task event, then we can use - * PM_RUN_* events interchangeably with their non RUN_* - * equivalents, e.g. PM_RUN_CYC instead of PM_CYC. - * XXX we should check if the task is an idle task. - */ - flags = 0; - if (event->attach_state & PERF_ATTACH_TASK) - flags |= PPMU_ONLY_COUNT_RUN; - - /* - * If this machine has limited events, check whether this - * event_id could go on a limited event. - */ - if (ppmu->flags & PPMU_LIMITED_PMC5_6) { - if (can_go_on_limited_pmc(event, ev, flags)) { - flags |= PPMU_LIMITED_PMC_OK; - } else if (ppmu->limited_pmc_event(ev)) { - /* - * The requested event_id is on a limited PMC, - * but we can't use a limited PMC; see if any - * alternative goes on a normal PMC. - */ - ev = normal_pmc_alternative(ev, flags); - if (!ev) - return -EINVAL; - } - } - - /* - * If this is in a group, check if it can go on with all the - * other hardware events in the group. We assume the event - * hasn't been linked into its leader's sibling list at this point. - */ - n = 0; - if (event->group_leader != event) { - n = collect_events(event->group_leader, ppmu->n_counter - 1, - ctrs, events, cflags); - if (n < 0) - return -EINVAL; - } - events[n] = ev; - ctrs[n] = event; - cflags[n] = flags; - if (check_excludes(ctrs, cflags, n, 1)) - return -EINVAL; - - cpuhw = &get_cpu_var(cpu_hw_events); - err = power_check_constraints(cpuhw, events, cflags, n + 1); - put_cpu_var(cpu_hw_events); - if (err) - return -EINVAL; - - event->hw.config = events[n]; - event->hw.event_base = cflags[n]; - event->hw.last_period = event->hw.sample_period; - local64_set(&event->hw.period_left, event->hw.last_period); - - /* - * See if we need to reserve the PMU. - * If no events are currently in use, then we have to take a - * mutex to ensure that we don't race with another task doing - * reserve_pmc_hardware or release_pmc_hardware. - */ - err = 0; - if (!atomic_inc_not_zero(&num_events)) { - mutex_lock(&pmc_reserve_mutex); - if (atomic_read(&num_events) == 0 && - reserve_pmc_hardware(perf_event_interrupt)) - err = -EBUSY; - else - atomic_inc(&num_events); - mutex_unlock(&pmc_reserve_mutex); - } - event->destroy = hw_perf_event_destroy; - - return err; -} - -static int power_pmu_event_idx(struct perf_event *event) -{ - return event->hw.idx; -} - -struct pmu power_pmu = { - .pmu_enable = power_pmu_enable, - .pmu_disable = power_pmu_disable, - .event_init = power_pmu_event_init, - .add = power_pmu_add, - .del = power_pmu_del, - .start = power_pmu_start, - .stop = power_pmu_stop, - .read = power_pmu_read, - .start_txn = power_pmu_start_txn, - .cancel_txn = power_pmu_cancel_txn, - .commit_txn = power_pmu_commit_txn, - .event_idx = power_pmu_event_idx, -}; - -/* - * A counter has overflowed; update its count and record - * things if requested. Note that interrupts are hard-disabled - * here so there is no possibility of being interrupted. - */ -static void record_and_restart(struct perf_event *event, unsigned long val, - struct pt_regs *regs) -{ - u64 period = event->hw.sample_period; - s64 prev, delta, left; - int record = 0; - - if (event->hw.state & PERF_HES_STOPPED) { - write_pmc(event->hw.idx, 0); - return; - } - - /* we don't have to worry about interrupts here */ - prev = local64_read(&event->hw.prev_count); - delta = check_and_compute_delta(prev, val); - local64_add(delta, &event->count); - - /* - * See if the total period for this event has expired, - * and update for the next period. - */ - val = 0; - left = local64_read(&event->hw.period_left) - delta; - if (period) { - if (left <= 0) { - left += period; - if (left <= 0) - left = period; - record = 1; - event->hw.last_period = event->hw.sample_period; - } - if (left < 0x80000000LL) - val = 0x80000000LL - left; - } - - write_pmc(event->hw.idx, val); - local64_set(&event->hw.prev_count, val); - local64_set(&event->hw.period_left, left); - perf_event_update_userpage(event); - - /* - * Finally record data if requested. - */ - if (record) { - struct perf_sample_data data; - - perf_sample_data_init(&data, ~0ULL); - data.period = event->hw.last_period; - - if (event->attr.sample_type & PERF_SAMPLE_ADDR) - perf_get_data_addr(regs, &data.addr); - - if (perf_event_overflow(event, &data, regs)) - power_pmu_stop(event, 0); - } -} - -/* - * Called from generic code to get the misc flags (i.e. processor mode) - * for an event_id. - */ -unsigned long perf_misc_flags(struct pt_regs *regs) -{ - u32 flags = perf_get_misc_flags(regs); - - if (flags) - return flags; - return user_mode(regs) ? PERF_RECORD_MISC_USER : - PERF_RECORD_MISC_KERNEL; -} - -/* - * Called from generic code to get the instruction pointer - * for an event_id. - */ -unsigned long perf_instruction_pointer(struct pt_regs *regs) -{ - unsigned long ip; - - if (TRAP(regs) != 0xf00) - return regs->nip; /* not a PMU interrupt */ - - ip = mfspr(SPRN_SIAR) + perf_ip_adjust(regs); - return ip; -} - -static bool pmc_overflow(unsigned long val) -{ - if ((int)val < 0) - return true; - - /* - * Events on POWER7 can roll back if a speculative event doesn't - * eventually complete. Unfortunately in some rare cases they will - * raise a performance monitor exception. We need to catch this to - * ensure we reset the PMC. In all cases the PMC will be 256 or less - * cycles from overflow. - * - * We only do this if the first pass fails to find any overflowing - * PMCs because a user might set a period of less than 256 and we - * don't want to mistakenly reset them. - */ - if (__is_processor(PV_POWER7) && ((0x80000000 - val) <= 256)) - return true; - - return false; -} - -/* - * Performance monitor interrupt stuff - */ -static void perf_event_interrupt(struct pt_regs *regs) -{ - int i; - struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events); - struct perf_event *event; - unsigned long val; - int found = 0; - int nmi; - - if (cpuhw->n_limited) - freeze_limited_counters(cpuhw, mfspr(SPRN_PMC5), - mfspr(SPRN_PMC6)); - - perf_read_regs(regs); - - nmi = perf_intr_is_nmi(regs); - if (nmi) - nmi_enter(); - else - irq_enter(); - - for (i = 0; i < cpuhw->n_events; ++i) { - event = cpuhw->event[i]; - if (!event->hw.idx || is_limited_pmc(event->hw.idx)) - continue; - val = read_pmc(event->hw.idx); - if ((int)val < 0) { - /* event has overflowed */ - found = 1; - record_and_restart(event, val, regs); - } - } - - /* - * In case we didn't find and reset the event that caused - * the interrupt, scan all events and reset any that are - * negative, to avoid getting continual interrupts. - * Any that we processed in the previous loop will not be negative. - */ - if (!found) { - for (i = 0; i < ppmu->n_counter; ++i) { - if (is_limited_pmc(i + 1)) - continue; - val = read_pmc(i + 1); - if (pmc_overflow(val)) - write_pmc(i + 1, 0); - } - } - - /* - * Reset MMCR0 to its normal value. This will set PMXE and - * clear FC (freeze counters) and PMAO (perf mon alert occurred) - * and thus allow interrupts to occur again. - * XXX might want to use MSR.PM to keep the events frozen until - * we get back out of this interrupt. - */ - write_mmcr0(cpuhw, cpuhw->mmcr[0]); - - if (nmi) - nmi_exit(); - else - irq_exit(); -} - -static void power_pmu_setup(int cpu) -{ - struct cpu_hw_events *cpuhw = &per_cpu(cpu_hw_events, cpu); - - if (!ppmu) - return; - memset(cpuhw, 0, sizeof(*cpuhw)); - cpuhw->mmcr[0] = MMCR0_FC; -} - -static int __cpuinit -power_pmu_notifier(struct notifier_block *self, unsigned long action, void *hcpu) -{ - unsigned int cpu = (long)hcpu; - - switch (action & ~CPU_TASKS_FROZEN) { - case CPU_UP_PREPARE: - power_pmu_setup(cpu); - break; - - default: - break; - } - - return NOTIFY_OK; -} - -int __cpuinit register_power_pmu(struct power_pmu *pmu) -{ - if (ppmu) - return -EBUSY; /* something's already registered */ - - ppmu = pmu; - pr_info("%s performance monitor hardware support registered\n", - pmu->name); - -#ifdef MSR_HV - /* - * Use FCHV to ignore kernel events if MSR.HV is set. - */ - if (mfmsr() & MSR_HV) - freeze_events_kernel = MMCR0_FCHV; -#endif /* CONFIG_PPC64 */ - - perf_pmu_register(&power_pmu, "cpu", PERF_TYPE_RAW); - perf_cpu_notifier(power_pmu_notifier); - - return 0; -} |
