From 849369d6c66d3054688672f97d31fceb8e8230fb Mon Sep 17 00:00:00 2001 From: root Date: Fri, 25 Dec 2015 04:40:36 +0000 Subject: initial_commit --- arch/powerpc/kernel/perf_event_fsl_emb.c | 688 +++++++++++++++++++++++++++++++ 1 file changed, 688 insertions(+) create mode 100644 arch/powerpc/kernel/perf_event_fsl_emb.c (limited to 'arch/powerpc/kernel/perf_event_fsl_emb.c') diff --git a/arch/powerpc/kernel/perf_event_fsl_emb.c b/arch/powerpc/kernel/perf_event_fsl_emb.c new file mode 100644 index 00000000..b0dc8f70 --- /dev/null +++ b/arch/powerpc/kernel/perf_event_fsl_emb.c @@ -0,0 +1,688 @@ +/* + * Performance event support - Freescale Embedded Performance Monitor + * + * Copyright 2008-2009 Paul Mackerras, IBM Corporation. + * Copyright 2010 Freescale Semiconductor, Inc. + * + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include + +struct cpu_hw_events { + int n_events; + int disabled; + u8 pmcs_enabled; + struct perf_event *event[MAX_HWEVENTS]; +}; +static DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events); + +static struct fsl_emb_pmu *ppmu; + +/* 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); + +/* + * 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) +{ +#ifdef __powerpc64__ + return !regs->softe; +#else + return 0; +#endif +} + +static void perf_event_interrupt(struct pt_regs *regs); + +/* + * Read one performance monitor counter (PMC). + */ +static unsigned long read_pmc(int idx) +{ + unsigned long val; + + switch (idx) { + case 0: + val = mfpmr(PMRN_PMC0); + break; + case 1: + val = mfpmr(PMRN_PMC1); + break; + case 2: + val = mfpmr(PMRN_PMC2); + break; + case 3: + val = mfpmr(PMRN_PMC3); + break; + 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 0: + mtpmr(PMRN_PMC0, val); + break; + case 1: + mtpmr(PMRN_PMC1, val); + break; + case 2: + mtpmr(PMRN_PMC2, val); + break; + case 3: + mtpmr(PMRN_PMC3, val); + break; + default: + printk(KERN_ERR "oops trying to write PMC%d\n", idx); + } + + isync(); +} + +/* + * Write one local control A register + */ +static void write_pmlca(int idx, unsigned long val) +{ + switch (idx) { + case 0: + mtpmr(PMRN_PMLCA0, val); + break; + case 1: + mtpmr(PMRN_PMLCA1, val); + break; + case 2: + mtpmr(PMRN_PMLCA2, val); + break; + case 3: + mtpmr(PMRN_PMLCA3, val); + break; + default: + printk(KERN_ERR "oops trying to write PMLCA%d\n", idx); + } + + isync(); +} + +/* + * Write one local control B register + */ +static void write_pmlcb(int idx, unsigned long val) +{ + switch (idx) { + case 0: + mtpmr(PMRN_PMLCB0, val); + break; + case 1: + mtpmr(PMRN_PMLCB1, val); + break; + case 2: + mtpmr(PMRN_PMLCB2, val); + break; + case 3: + mtpmr(PMRN_PMLCB3, val); + break; + default: + printk(KERN_ERR "oops trying to write PMLCB%d\n", idx); + } + + isync(); +} + +static void fsl_emb_pmu_read(struct perf_event *event) +{ + s64 val, delta, prev; + + if (event->hw.state & PERF_HES_STOPPED) + 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); + } while (local64_cmpxchg(&event->hw.prev_count, prev, val) != prev); + + /* The counters are only 32 bits wide */ + delta = (val - prev) & 0xfffffffful; + local64_add(delta, &event->count); + local64_sub(delta, &event->hw.period_left); +} + +/* + * Disable all events to prevent PMU interrupts and to allow + * events to be added or removed. + */ +static void fsl_emb_pmu_disable(struct pmu *pmu) +{ + struct cpu_hw_events *cpuhw; + unsigned long flags; + + local_irq_save(flags); + cpuhw = &__get_cpu_var(cpu_hw_events); + + if (!cpuhw->disabled) { + cpuhw->disabled = 1; + + /* + * Check if we ever enabled the PMU on this cpu. + */ + if (!cpuhw->pmcs_enabled) { + ppc_enable_pmcs(); + cpuhw->pmcs_enabled = 1; + } + + if (atomic_read(&num_events)) { + /* + * Set the 'freeze all counters' bit, and disable + * interrupts. The barrier is to make sure the + * mtpmr has been executed and the PMU has frozen + * the events before we return. + */ + + mtpmr(PMRN_PMGC0, PMGC0_FAC); + isync(); + } + } + 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 fsl_emb_pmu_enable(struct pmu *pmu) +{ + struct cpu_hw_events *cpuhw; + unsigned long flags; + + local_irq_save(flags); + cpuhw = &__get_cpu_var(cpu_hw_events); + if (!cpuhw->disabled) + goto out; + + cpuhw->disabled = 0; + ppc_set_pmu_inuse(cpuhw->n_events != 0); + + if (cpuhw->n_events > 0) { + mtpmr(PMRN_PMGC0, PMGC0_PMIE | PMGC0_FCECE); + isync(); + } + + out: + local_irq_restore(flags); +} + +static int collect_events(struct perf_event *group, int max_count, + struct perf_event *ctrs[]) +{ + int n = 0; + struct perf_event *event; + + if (!is_software_event(group)) { + if (n >= max_count) + return -1; + ctrs[n] = group; + n++; + } + 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; + n++; + } + } + return n; +} + +/* context locked on entry */ +static int fsl_emb_pmu_add(struct perf_event *event, int flags) +{ + struct cpu_hw_events *cpuhw; + int ret = -EAGAIN; + int num_counters = ppmu->n_counter; + u64 val; + int i; + + perf_pmu_disable(event->pmu); + cpuhw = &get_cpu_var(cpu_hw_events); + + if (event->hw.config & FSL_EMB_EVENT_RESTRICTED) + num_counters = ppmu->n_restricted; + + /* + * Allocate counters from top-down, so that restricted-capable + * counters are kept free as long as possible. + */ + for (i = num_counters - 1; i >= 0; i--) { + if (cpuhw->event[i]) + continue; + + break; + } + + if (i < 0) + goto out; + + event->hw.idx = i; + cpuhw->event[i] = event; + ++cpuhw->n_events; + + val = 0; + if (event->hw.sample_period) { + s64 left = local64_read(&event->hw.period_left); + if (left < 0x80000000L) + val = 0x80000000L - left; + } + local64_set(&event->hw.prev_count, val); + + if (!(flags & PERF_EF_START)) { + event->hw.state = PERF_HES_STOPPED | PERF_HES_UPTODATE; + val = 0; + } + + write_pmc(i, val); + perf_event_update_userpage(event); + + write_pmlcb(i, event->hw.config >> 32); + write_pmlca(i, event->hw.config_base); + + ret = 0; + out: + put_cpu_var(cpu_hw_events); + perf_pmu_enable(event->pmu); + return ret; +} + +/* context locked on entry */ +static void fsl_emb_pmu_del(struct perf_event *event, int flags) +{ + struct cpu_hw_events *cpuhw; + int i = event->hw.idx; + + perf_pmu_disable(event->pmu); + if (i < 0) + goto out; + + fsl_emb_pmu_read(event); + + cpuhw = &get_cpu_var(cpu_hw_events); + + WARN_ON(event != cpuhw->event[event->hw.idx]); + + write_pmlca(i, 0); + write_pmlcb(i, 0); + write_pmc(i, 0); + + cpuhw->event[i] = NULL; + event->hw.idx = -1; + + /* + * TODO: if at least one restricted event exists, and we + * just freed up a non-restricted-capable counter, and + * there is a restricted-capable counter occupied by + * a non-restricted event, migrate that event to the + * vacated counter. + */ + + cpuhw->n_events--; + + out: + perf_pmu_enable(event->pmu); + put_cpu_var(cpu_hw_events); +} + +static void fsl_emb_pmu_start(struct perf_event *event, int ef_flags) +{ + unsigned long flags; + s64 left; + + if (event->hw.idx < 0 || !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); + write_pmc(event->hw.idx, left); + + perf_event_update_userpage(event); + perf_pmu_enable(event->pmu); + local_irq_restore(flags); +} + +static void fsl_emb_pmu_stop(struct perf_event *event, int ef_flags) +{ + unsigned long flags; + + if (event->hw.idx < 0 || !event->hw.sample_period) + return; + + if (event->hw.state & PERF_HES_STOPPED) + return; + + local_irq_save(flags); + perf_pmu_disable(event->pmu); + + fsl_emb_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); +} + +/* + * 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 fsl_emb_pmu_event_init(struct perf_event *event) +{ + u64 ev; + struct perf_event *events[MAX_HWEVENTS]; + int n; + int err; + int num_restricted; + int i; + + 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 = ppmu->xlate_event(ev); + if (!(event->hw.config & FSL_EMB_EVENT_VALID)) + 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, events); + if (n < 0) + return -EINVAL; + } + + if (event->hw.config & FSL_EMB_EVENT_RESTRICTED) { + num_restricted = 0; + for (i = 0; i < n; i++) { + if (events[i]->hw.config & FSL_EMB_EVENT_RESTRICTED) + num_restricted++; + } + + if (num_restricted >= ppmu->n_restricted) + return -EINVAL; + } + + event->hw.idx = -1; + + event->hw.config_base = PMLCA_CE | PMLCA_FCM1 | + (u32)((ev << 16) & PMLCA_EVENT_MASK); + + if (event->attr.exclude_user) + event->hw.config_base |= PMLCA_FCU; + if (event->attr.exclude_kernel) + event->hw.config_base |= PMLCA_FCS; + if (event->attr.exclude_idle) + return -ENOTSUPP; + + 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); + + mtpmr(PMRN_PMGC0, PMGC0_FAC); + isync(); + } + event->destroy = hw_perf_event_destroy; + + return err; +} + +static struct pmu fsl_emb_pmu = { + .pmu_enable = fsl_emb_pmu_enable, + .pmu_disable = fsl_emb_pmu_disable, + .event_init = fsl_emb_pmu_event_init, + .add = fsl_emb_pmu_add, + .del = fsl_emb_pmu_del, + .start = fsl_emb_pmu_start, + .stop = fsl_emb_pmu_stop, + .read = fsl_emb_pmu_read, +}; + +/* + * 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, int nmi) +{ + 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 = (val - prev) & 0xfffffffful; + 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, 0); + data.period = event->hw.last_period; + + if (perf_event_overflow(event, nmi, &data, regs)) + fsl_emb_pmu_stop(event, 0); + } +} + +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; + + nmi = perf_intr_is_nmi(regs); + if (nmi) + nmi_enter(); + else + irq_enter(); + + for (i = 0; i < ppmu->n_counter; ++i) { + event = cpuhw->event[i]; + + val = read_pmc(i); + if ((int)val < 0) { + if (event) { + /* event has overflowed */ + found = 1; + record_and_restart(event, val, regs, nmi); + } else { + /* + * Disabled counter is negative, + * reset it just in case. + */ + write_pmc(i, 0); + } + } + } + + /* PMM will keep counters frozen until we return from the interrupt. */ + mtmsr(mfmsr() | MSR_PMM); + mtpmr(PMRN_PMGC0, PMGC0_PMIE | PMGC0_FCECE); + isync(); + + if (nmi) + nmi_exit(); + else + irq_exit(); +} + +void hw_perf_event_setup(int cpu) +{ + struct cpu_hw_events *cpuhw = &per_cpu(cpu_hw_events, cpu); + + memset(cpuhw, 0, sizeof(*cpuhw)); +} + +int register_fsl_emb_pmu(struct fsl_emb_pmu *pmu) +{ + if (ppmu) + return -EBUSY; /* something's already registered */ + + ppmu = pmu; + pr_info("%s performance monitor hardware support registered\n", + pmu->name); + + perf_pmu_register(&fsl_emb_pmu, "cpu", PERF_TYPE_RAW); + + return 0; +} -- cgit v1.2.3