diff options
Diffstat (limited to 'arch/sparc/kernel/perf_counter.c')
-rw-r--r-- | arch/sparc/kernel/perf_counter.c | 557 |
1 files changed, 0 insertions, 557 deletions
diff --git a/arch/sparc/kernel/perf_counter.c b/arch/sparc/kernel/perf_counter.c deleted file mode 100644 index 09de4035eaa9..000000000000 --- a/arch/sparc/kernel/perf_counter.c +++ /dev/null @@ -1,557 +0,0 @@ -/* Performance counter support for sparc64. - * - * Copyright (C) 2009 David S. Miller <davem@davemloft.net> - * - * This code is based almost entirely upon the x86 perf counter - * code, which is: - * - * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de> - * Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar - * Copyright (C) 2009 Jaswinder Singh Rajput - * Copyright (C) 2009 Advanced Micro Devices, Inc., Robert Richter - * Copyright (C) 2008-2009 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com> - */ - -#include <linux/perf_counter.h> -#include <linux/kprobes.h> -#include <linux/kernel.h> -#include <linux/kdebug.h> -#include <linux/mutex.h> - -#include <asm/cpudata.h> -#include <asm/atomic.h> -#include <asm/nmi.h> -#include <asm/pcr.h> - -/* Sparc64 chips have two performance counters, 32-bits each, with - * overflow interrupts generated on transition from 0xffffffff to 0. - * The counters are accessed in one go using a 64-bit register. - * - * Both counters are controlled using a single control register. The - * only way to stop all sampling is to clear all of the context (user, - * supervisor, hypervisor) sampling enable bits. But these bits apply - * to both counters, thus the two counters can't be enabled/disabled - * individually. - * - * The control register has two event fields, one for each of the two - * counters. It's thus nearly impossible to have one counter going - * while keeping the other one stopped. Therefore it is possible to - * get overflow interrupts for counters not currently "in use" and - * that condition must be checked in the overflow interrupt handler. - * - * So we use a hack, in that we program inactive counters with the - * "sw_count0" and "sw_count1" events. These count how many times - * the instruction "sethi %hi(0xfc000), %g0" is executed. It's an - * unusual way to encode a NOP and therefore will not trigger in - * normal code. - */ - -#define MAX_HWCOUNTERS 2 -#define MAX_PERIOD ((1UL << 32) - 1) - -#define PIC_UPPER_INDEX 0 -#define PIC_LOWER_INDEX 1 - -struct cpu_hw_counters { - struct perf_counter *counters[MAX_HWCOUNTERS]; - unsigned long used_mask[BITS_TO_LONGS(MAX_HWCOUNTERS)]; - unsigned long active_mask[BITS_TO_LONGS(MAX_HWCOUNTERS)]; - int enabled; -}; -DEFINE_PER_CPU(struct cpu_hw_counters, cpu_hw_counters) = { .enabled = 1, }; - -struct perf_event_map { - u16 encoding; - u8 pic_mask; -#define PIC_NONE 0x00 -#define PIC_UPPER 0x01 -#define PIC_LOWER 0x02 -}; - -struct sparc_pmu { - const struct perf_event_map *(*event_map)(int); - int max_events; - int upper_shift; - int lower_shift; - int event_mask; - int hv_bit; - int irq_bit; - int upper_nop; - int lower_nop; -}; - -static const struct perf_event_map ultra3i_perfmon_event_map[] = { - [PERF_COUNT_HW_CPU_CYCLES] = { 0x0000, PIC_UPPER | PIC_LOWER }, - [PERF_COUNT_HW_INSTRUCTIONS] = { 0x0001, PIC_UPPER | PIC_LOWER }, - [PERF_COUNT_HW_CACHE_REFERENCES] = { 0x0009, PIC_LOWER }, - [PERF_COUNT_HW_CACHE_MISSES] = { 0x0009, PIC_UPPER }, -}; - -static const struct perf_event_map *ultra3i_event_map(int event) -{ - return &ultra3i_perfmon_event_map[event]; -} - -static const struct sparc_pmu ultra3i_pmu = { - .event_map = ultra3i_event_map, - .max_events = ARRAY_SIZE(ultra3i_perfmon_event_map), - .upper_shift = 11, - .lower_shift = 4, - .event_mask = 0x3f, - .upper_nop = 0x1c, - .lower_nop = 0x14, -}; - -static const struct perf_event_map niagara2_perfmon_event_map[] = { - [PERF_COUNT_HW_CPU_CYCLES] = { 0x02ff, PIC_UPPER | PIC_LOWER }, - [PERF_COUNT_HW_INSTRUCTIONS] = { 0x02ff, PIC_UPPER | PIC_LOWER }, - [PERF_COUNT_HW_CACHE_REFERENCES] = { 0x0208, PIC_UPPER | PIC_LOWER }, - [PERF_COUNT_HW_CACHE_MISSES] = { 0x0302, PIC_UPPER | PIC_LOWER }, - [PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = { 0x0201, PIC_UPPER | PIC_LOWER }, - [PERF_COUNT_HW_BRANCH_MISSES] = { 0x0202, PIC_UPPER | PIC_LOWER }, -}; - -static const struct perf_event_map *niagara2_event_map(int event) -{ - return &niagara2_perfmon_event_map[event]; -} - -static const struct sparc_pmu niagara2_pmu = { - .event_map = niagara2_event_map, - .max_events = ARRAY_SIZE(niagara2_perfmon_event_map), - .upper_shift = 19, - .lower_shift = 6, - .event_mask = 0xfff, - .hv_bit = 0x8, - .irq_bit = 0x03, - .upper_nop = 0x220, - .lower_nop = 0x220, -}; - -static const struct sparc_pmu *sparc_pmu __read_mostly; - -static u64 event_encoding(u64 event, int idx) -{ - if (idx == PIC_UPPER_INDEX) - event <<= sparc_pmu->upper_shift; - else - event <<= sparc_pmu->lower_shift; - return event; -} - -static u64 mask_for_index(int idx) -{ - return event_encoding(sparc_pmu->event_mask, idx); -} - -static u64 nop_for_index(int idx) -{ - return event_encoding(idx == PIC_UPPER_INDEX ? - sparc_pmu->upper_nop : - sparc_pmu->lower_nop, idx); -} - -static inline void sparc_pmu_enable_counter(struct hw_perf_counter *hwc, - int idx) -{ - u64 val, mask = mask_for_index(idx); - - val = pcr_ops->read(); - pcr_ops->write((val & ~mask) | hwc->config); -} - -static inline void sparc_pmu_disable_counter(struct hw_perf_counter *hwc, - int idx) -{ - u64 mask = mask_for_index(idx); - u64 nop = nop_for_index(idx); - u64 val = pcr_ops->read(); - - pcr_ops->write((val & ~mask) | nop); -} - -void hw_perf_enable(void) -{ - struct cpu_hw_counters *cpuc = &__get_cpu_var(cpu_hw_counters); - u64 val; - int i; - - if (cpuc->enabled) - return; - - cpuc->enabled = 1; - barrier(); - - val = pcr_ops->read(); - - for (i = 0; i < MAX_HWCOUNTERS; i++) { - struct perf_counter *cp = cpuc->counters[i]; - struct hw_perf_counter *hwc; - - if (!cp) - continue; - hwc = &cp->hw; - val |= hwc->config_base; - } - - pcr_ops->write(val); -} - -void hw_perf_disable(void) -{ - struct cpu_hw_counters *cpuc = &__get_cpu_var(cpu_hw_counters); - u64 val; - - if (!cpuc->enabled) - return; - - cpuc->enabled = 0; - - val = pcr_ops->read(); - val &= ~(PCR_UTRACE | PCR_STRACE | - sparc_pmu->hv_bit | sparc_pmu->irq_bit); - pcr_ops->write(val); -} - -static u32 read_pmc(int idx) -{ - u64 val; - - read_pic(val); - if (idx == PIC_UPPER_INDEX) - val >>= 32; - - return val & 0xffffffff; -} - -static void write_pmc(int idx, u64 val) -{ - u64 shift, mask, pic; - - shift = 0; - if (idx == PIC_UPPER_INDEX) - shift = 32; - - mask = ((u64) 0xffffffff) << shift; - val <<= shift; - - read_pic(pic); - pic &= ~mask; - pic |= val; - write_pic(pic); -} - -static int sparc_perf_counter_set_period(struct perf_counter *counter, - struct hw_perf_counter *hwc, int idx) -{ - s64 left = atomic64_read(&hwc->period_left); - s64 period = hwc->sample_period; - int ret = 0; - - if (unlikely(left <= -period)) { - left = period; - atomic64_set(&hwc->period_left, left); - hwc->last_period = period; - ret = 1; - } - - if (unlikely(left <= 0)) { - left += period; - atomic64_set(&hwc->period_left, left); - hwc->last_period = period; - ret = 1; - } - if (left > MAX_PERIOD) - left = MAX_PERIOD; - - atomic64_set(&hwc->prev_count, (u64)-left); - - write_pmc(idx, (u64)(-left) & 0xffffffff); - - perf_counter_update_userpage(counter); - - return ret; -} - -static int sparc_pmu_enable(struct perf_counter *counter) -{ - struct cpu_hw_counters *cpuc = &__get_cpu_var(cpu_hw_counters); - struct hw_perf_counter *hwc = &counter->hw; - int idx = hwc->idx; - - if (test_and_set_bit(idx, cpuc->used_mask)) - return -EAGAIN; - - sparc_pmu_disable_counter(hwc, idx); - - cpuc->counters[idx] = counter; - set_bit(idx, cpuc->active_mask); - - sparc_perf_counter_set_period(counter, hwc, idx); - sparc_pmu_enable_counter(hwc, idx); - perf_counter_update_userpage(counter); - return 0; -} - -static u64 sparc_perf_counter_update(struct perf_counter *counter, - struct hw_perf_counter *hwc, int idx) -{ - int shift = 64 - 32; - u64 prev_raw_count, new_raw_count; - s64 delta; - -again: - prev_raw_count = atomic64_read(&hwc->prev_count); - new_raw_count = read_pmc(idx); - - if (atomic64_cmpxchg(&hwc->prev_count, prev_raw_count, - new_raw_count) != prev_raw_count) - goto again; - - delta = (new_raw_count << shift) - (prev_raw_count << shift); - delta >>= shift; - - atomic64_add(delta, &counter->count); - atomic64_sub(delta, &hwc->period_left); - - return new_raw_count; -} - -static void sparc_pmu_disable(struct perf_counter *counter) -{ - struct cpu_hw_counters *cpuc = &__get_cpu_var(cpu_hw_counters); - struct hw_perf_counter *hwc = &counter->hw; - int idx = hwc->idx; - - clear_bit(idx, cpuc->active_mask); - sparc_pmu_disable_counter(hwc, idx); - - barrier(); - - sparc_perf_counter_update(counter, hwc, idx); - cpuc->counters[idx] = NULL; - clear_bit(idx, cpuc->used_mask); - - perf_counter_update_userpage(counter); -} - -static void sparc_pmu_read(struct perf_counter *counter) -{ - struct hw_perf_counter *hwc = &counter->hw; - sparc_perf_counter_update(counter, hwc, hwc->idx); -} - -static void sparc_pmu_unthrottle(struct perf_counter *counter) -{ - struct hw_perf_counter *hwc = &counter->hw; - sparc_pmu_enable_counter(hwc, hwc->idx); -} - -static atomic_t active_counters = ATOMIC_INIT(0); -static DEFINE_MUTEX(pmc_grab_mutex); - -void perf_counter_grab_pmc(void) -{ - if (atomic_inc_not_zero(&active_counters)) - return; - - mutex_lock(&pmc_grab_mutex); - if (atomic_read(&active_counters) == 0) { - if (atomic_read(&nmi_active) > 0) { - on_each_cpu(stop_nmi_watchdog, NULL, 1); - BUG_ON(atomic_read(&nmi_active) != 0); - } - atomic_inc(&active_counters); - } - mutex_unlock(&pmc_grab_mutex); -} - -void perf_counter_release_pmc(void) -{ - if (atomic_dec_and_mutex_lock(&active_counters, &pmc_grab_mutex)) { - if (atomic_read(&nmi_active) == 0) - on_each_cpu(start_nmi_watchdog, NULL, 1); - mutex_unlock(&pmc_grab_mutex); - } -} - -static void hw_perf_counter_destroy(struct perf_counter *counter) -{ - perf_counter_release_pmc(); -} - -static int __hw_perf_counter_init(struct perf_counter *counter) -{ - struct perf_counter_attr *attr = &counter->attr; - struct hw_perf_counter *hwc = &counter->hw; - const struct perf_event_map *pmap; - u64 enc; - - if (atomic_read(&nmi_active) < 0) - return -ENODEV; - - if (attr->type != PERF_TYPE_HARDWARE) - return -EOPNOTSUPP; - - if (attr->config >= sparc_pmu->max_events) - return -EINVAL; - - perf_counter_grab_pmc(); - counter->destroy = hw_perf_counter_destroy; - - /* We save the enable bits in the config_base. So to - * turn off sampling just write 'config', and to enable - * things write 'config | config_base'. - */ - hwc->config_base = sparc_pmu->irq_bit; - if (!attr->exclude_user) - hwc->config_base |= PCR_UTRACE; - if (!attr->exclude_kernel) - hwc->config_base |= PCR_STRACE; - if (!attr->exclude_hv) - hwc->config_base |= sparc_pmu->hv_bit; - - if (!hwc->sample_period) { - hwc->sample_period = MAX_PERIOD; - hwc->last_period = hwc->sample_period; - atomic64_set(&hwc->period_left, hwc->sample_period); - } - - pmap = sparc_pmu->event_map(attr->config); - - enc = pmap->encoding; - if (pmap->pic_mask & PIC_UPPER) { - hwc->idx = PIC_UPPER_INDEX; - enc <<= sparc_pmu->upper_shift; - } else { - hwc->idx = PIC_LOWER_INDEX; - enc <<= sparc_pmu->lower_shift; - } - - hwc->config |= enc; - return 0; -} - -static const struct pmu pmu = { - .enable = sparc_pmu_enable, - .disable = sparc_pmu_disable, - .read = sparc_pmu_read, - .unthrottle = sparc_pmu_unthrottle, -}; - -const struct pmu *hw_perf_counter_init(struct perf_counter *counter) -{ - int err = __hw_perf_counter_init(counter); - - if (err) - return ERR_PTR(err); - return &pmu; -} - -void perf_counter_print_debug(void) -{ - unsigned long flags; - u64 pcr, pic; - int cpu; - - if (!sparc_pmu) - return; - - local_irq_save(flags); - - cpu = smp_processor_id(); - - pcr = pcr_ops->read(); - read_pic(pic); - - pr_info("\n"); - pr_info("CPU#%d: PCR[%016llx] PIC[%016llx]\n", - cpu, pcr, pic); - - local_irq_restore(flags); -} - -static int __kprobes perf_counter_nmi_handler(struct notifier_block *self, - unsigned long cmd, void *__args) -{ - struct die_args *args = __args; - struct perf_sample_data data; - struct cpu_hw_counters *cpuc; - struct pt_regs *regs; - int idx; - - if (!atomic_read(&active_counters)) - return NOTIFY_DONE; - - switch (cmd) { - case DIE_NMI: - break; - - default: - return NOTIFY_DONE; - } - - regs = args->regs; - - data.regs = regs; - data.addr = 0; - - cpuc = &__get_cpu_var(cpu_hw_counters); - for (idx = 0; idx < MAX_HWCOUNTERS; idx++) { - struct perf_counter *counter = cpuc->counters[idx]; - struct hw_perf_counter *hwc; - u64 val; - - if (!test_bit(idx, cpuc->active_mask)) - continue; - hwc = &counter->hw; - val = sparc_perf_counter_update(counter, hwc, idx); - if (val & (1ULL << 31)) - continue; - - data.period = counter->hw.last_period; - if (!sparc_perf_counter_set_period(counter, hwc, idx)) - continue; - - if (perf_counter_overflow(counter, 1, &data)) - sparc_pmu_disable_counter(hwc, idx); - } - - return NOTIFY_STOP; -} - -static __read_mostly struct notifier_block perf_counter_nmi_notifier = { - .notifier_call = perf_counter_nmi_handler, -}; - -static bool __init supported_pmu(void) -{ - if (!strcmp(sparc_pmu_type, "ultra3i")) { - sparc_pmu = &ultra3i_pmu; - return true; - } - if (!strcmp(sparc_pmu_type, "niagara2")) { - sparc_pmu = &niagara2_pmu; - return true; - } - return false; -} - -void __init init_hw_perf_counters(void) -{ - pr_info("Performance counters: "); - - if (!supported_pmu()) { - pr_cont("No support for PMU type '%s'\n", sparc_pmu_type); - return; - } - - pr_cont("Supported PMU type is '%s'\n", sparc_pmu_type); - - /* All sparc64 PMUs currently have 2 counters. But this simple - * driver only supports one active counter at a time. - */ - perf_max_counters = 1; - - register_die_notifier(&perf_counter_nmi_notifier); -} |