| /* |
| * 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; |
| |
| 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; |
| } |
| |
| 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, |
| }; |
| |
| /* |
| * 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; |
| } |