diff options
Diffstat (limited to 'ANDROID_3.4.5/arch/arm/kernel/perf_event.c')
| -rw-r--r-- | ANDROID_3.4.5/arch/arm/kernel/perf_event.c | 855 |
1 files changed, 0 insertions, 855 deletions
diff --git a/ANDROID_3.4.5/arch/arm/kernel/perf_event.c b/ANDROID_3.4.5/arch/arm/kernel/perf_event.c deleted file mode 100644 index 186c8cb9..00000000 --- a/ANDROID_3.4.5/arch/arm/kernel/perf_event.c +++ /dev/null @@ -1,855 +0,0 @@ -#undef DEBUG - -/* - * ARM performance counter support. - * - * Copyright (C) 2009 picoChip Designs, Ltd., Jamie Iles - * Copyright (C) 2010 ARM Ltd., Will Deacon <will.deacon@arm.com> - * - * This code is based on the sparc64 perf event code, which is in turn based - * on the x86 code. Callchain code is based on the ARM OProfile backtrace - * code. - */ -#define pr_fmt(fmt) "hw perfevents: " fmt - -#include <linux/bitmap.h> -#include <linux/interrupt.h> -#include <linux/kernel.h> -#include <linux/export.h> -#include <linux/perf_event.h> -#include <linux/platform_device.h> -#include <linux/spinlock.h> -#include <linux/uaccess.h> - -#include <asm/cputype.h> -#include <asm/irq.h> -#include <asm/irq_regs.h> -#include <asm/pmu.h> -#include <asm/stacktrace.h> - -/* - * ARMv6 supports a maximum of 3 events, starting from index 0. If we add - * another platform that supports more, we need to increase this to be the - * largest of all platforms. - * - * ARMv7 supports up to 32 events: - * cycle counter CCNT + 31 events counters CNT0..30. - * Cortex-A8 has 1+4 counters, Cortex-A9 has 1+6 counters. - */ -#define ARMPMU_MAX_HWEVENTS 32 - -static DEFINE_PER_CPU(struct perf_event * [ARMPMU_MAX_HWEVENTS], hw_events); -static DEFINE_PER_CPU(unsigned long [BITS_TO_LONGS(ARMPMU_MAX_HWEVENTS)], used_mask); -static DEFINE_PER_CPU(struct pmu_hw_events, cpu_hw_events); - -#define to_arm_pmu(p) (container_of(p, struct arm_pmu, pmu)) - -/* Set at runtime when we know what CPU type we are. */ -static struct arm_pmu *cpu_pmu; - -enum arm_perf_pmu_ids -armpmu_get_pmu_id(void) -{ - int id = -ENODEV; - - if (cpu_pmu != NULL) - id = cpu_pmu->id; - - return id; -} -EXPORT_SYMBOL_GPL(armpmu_get_pmu_id); - -int perf_num_counters(void) -{ - int max_events = 0; - - if (cpu_pmu != NULL) - max_events = cpu_pmu->num_events; - - return max_events; -} -EXPORT_SYMBOL_GPL(perf_num_counters); - -#define HW_OP_UNSUPPORTED 0xFFFF - -#define C(_x) \ - PERF_COUNT_HW_CACHE_##_x - -#define CACHE_OP_UNSUPPORTED 0xFFFF - -static int -armpmu_map_cache_event(const unsigned (*cache_map) - [PERF_COUNT_HW_CACHE_MAX] - [PERF_COUNT_HW_CACHE_OP_MAX] - [PERF_COUNT_HW_CACHE_RESULT_MAX], - u64 config) -{ - unsigned int cache_type, cache_op, cache_result, ret; - - cache_type = (config >> 0) & 0xff; - if (cache_type >= PERF_COUNT_HW_CACHE_MAX) - return -EINVAL; - - cache_op = (config >> 8) & 0xff; - if (cache_op >= PERF_COUNT_HW_CACHE_OP_MAX) - return -EINVAL; - - cache_result = (config >> 16) & 0xff; - if (cache_result >= PERF_COUNT_HW_CACHE_RESULT_MAX) - return -EINVAL; - - ret = (int)(*cache_map)[cache_type][cache_op][cache_result]; - - if (ret == CACHE_OP_UNSUPPORTED) - return -ENOENT; - - return ret; -} - -static int -armpmu_map_event(const unsigned (*event_map)[PERF_COUNT_HW_MAX], u64 config) -{ - int mapping = (*event_map)[config]; - return mapping == HW_OP_UNSUPPORTED ? -ENOENT : mapping; -} - -static int -armpmu_map_raw_event(u32 raw_event_mask, u64 config) -{ - return (int)(config & raw_event_mask); -} - -static int map_cpu_event(struct perf_event *event, - const unsigned (*event_map)[PERF_COUNT_HW_MAX], - const unsigned (*cache_map) - [PERF_COUNT_HW_CACHE_MAX] - [PERF_COUNT_HW_CACHE_OP_MAX] - [PERF_COUNT_HW_CACHE_RESULT_MAX], - u32 raw_event_mask) -{ - u64 config = event->attr.config; - - switch (event->attr.type) { - case PERF_TYPE_HARDWARE: - return armpmu_map_event(event_map, config); - case PERF_TYPE_HW_CACHE: - return armpmu_map_cache_event(cache_map, config); - case PERF_TYPE_RAW: - return armpmu_map_raw_event(raw_event_mask, config); - } - - return -ENOENT; -} - -int -armpmu_event_set_period(struct perf_event *event, - struct hw_perf_event *hwc, - int idx) -{ - struct arm_pmu *armpmu = to_arm_pmu(event->pmu); - s64 left = local64_read(&hwc->period_left); - s64 period = hwc->sample_period; - int ret = 0; - - if (unlikely(left <= -period)) { - left = period; - local64_set(&hwc->period_left, left); - hwc->last_period = period; - ret = 1; - } - - if (unlikely(left <= 0)) { - left += period; - local64_set(&hwc->period_left, left); - hwc->last_period = period; - ret = 1; - } - - if (left > (s64)armpmu->max_period) - left = armpmu->max_period; - - local64_set(&hwc->prev_count, (u64)-left); - - armpmu->write_counter(idx, (u64)(-left) & 0xffffffff); - - perf_event_update_userpage(event); - - return ret; -} - -u64 -armpmu_event_update(struct perf_event *event, - struct hw_perf_event *hwc, - int idx) -{ - struct arm_pmu *armpmu = to_arm_pmu(event->pmu); - u64 delta, prev_raw_count, new_raw_count; - -again: - prev_raw_count = local64_read(&hwc->prev_count); - new_raw_count = armpmu->read_counter(idx); - - if (local64_cmpxchg(&hwc->prev_count, prev_raw_count, - new_raw_count) != prev_raw_count) - goto again; - - delta = (new_raw_count - prev_raw_count) & armpmu->max_period; - - local64_add(delta, &event->count); - local64_sub(delta, &hwc->period_left); - - return new_raw_count; -} - -static void -armpmu_read(struct perf_event *event) -{ - struct hw_perf_event *hwc = &event->hw; - - /* Don't read disabled counters! */ - if (hwc->idx < 0) - return; - - armpmu_event_update(event, hwc, hwc->idx); -} - -static void -armpmu_stop(struct perf_event *event, int flags) -{ - struct arm_pmu *armpmu = to_arm_pmu(event->pmu); - struct hw_perf_event *hwc = &event->hw; - - /* - * ARM pmu always has to update the counter, so ignore - * PERF_EF_UPDATE, see comments in armpmu_start(). - */ - if (!(hwc->state & PERF_HES_STOPPED)) { - armpmu->disable(hwc, hwc->idx); - barrier(); /* why? */ - armpmu_event_update(event, hwc, hwc->idx); - hwc->state |= PERF_HES_STOPPED | PERF_HES_UPTODATE; - } -} - -static void -armpmu_start(struct perf_event *event, int flags) -{ - struct arm_pmu *armpmu = to_arm_pmu(event->pmu); - struct hw_perf_event *hwc = &event->hw; - - /* - * ARM pmu always has to reprogram the period, so ignore - * PERF_EF_RELOAD, see the comment below. - */ - if (flags & PERF_EF_RELOAD) - WARN_ON_ONCE(!(hwc->state & PERF_HES_UPTODATE)); - - hwc->state = 0; - /* - * Set the period again. Some counters can't be stopped, so when we - * were stopped we simply disabled the IRQ source and the counter - * may have been left counting. If we don't do this step then we may - * get an interrupt too soon or *way* too late if the overflow has - * happened since disabling. - */ - armpmu_event_set_period(event, hwc, hwc->idx); - armpmu->enable(hwc, hwc->idx); -} - -static void -armpmu_del(struct perf_event *event, int flags) -{ - struct arm_pmu *armpmu = to_arm_pmu(event->pmu); - struct pmu_hw_events *hw_events = armpmu->get_hw_events(); - struct hw_perf_event *hwc = &event->hw; - int idx = hwc->idx; - - WARN_ON(idx < 0); - - armpmu_stop(event, PERF_EF_UPDATE); - hw_events->events[idx] = NULL; - clear_bit(idx, hw_events->used_mask); - - perf_event_update_userpage(event); -} - -static int -armpmu_add(struct perf_event *event, int flags) -{ - struct arm_pmu *armpmu = to_arm_pmu(event->pmu); - struct pmu_hw_events *hw_events = armpmu->get_hw_events(); - struct hw_perf_event *hwc = &event->hw; - int idx; - int err = 0; - - perf_pmu_disable(event->pmu); - - /* If we don't have a space for the counter then finish early. */ - idx = armpmu->get_event_idx(hw_events, hwc); - if (idx < 0) { - err = idx; - goto out; - } - - /* - * If there is an event in the counter we are going to use then make - * sure it is disabled. - */ - event->hw.idx = idx; - armpmu->disable(hwc, idx); - hw_events->events[idx] = event; - - hwc->state = PERF_HES_STOPPED | PERF_HES_UPTODATE; - if (flags & PERF_EF_START) - armpmu_start(event, PERF_EF_RELOAD); - - /* Propagate our changes to the userspace mapping. */ - perf_event_update_userpage(event); - -out: - perf_pmu_enable(event->pmu); - return err; -} - -static int -validate_event(struct pmu_hw_events *hw_events, - struct perf_event *event) -{ - struct arm_pmu *armpmu = to_arm_pmu(event->pmu); - struct hw_perf_event fake_event = event->hw; - struct pmu *leader_pmu = event->group_leader->pmu; - - if (event->pmu != leader_pmu || event->state <= PERF_EVENT_STATE_OFF) - return 1; - - return armpmu->get_event_idx(hw_events, &fake_event) >= 0; -} - -static int -validate_group(struct perf_event *event) -{ - struct perf_event *sibling, *leader = event->group_leader; - struct pmu_hw_events fake_pmu; - DECLARE_BITMAP(fake_used_mask, ARMPMU_MAX_HWEVENTS); - - /* - * Initialise the fake PMU. We only need to populate the - * used_mask for the purposes of validation. - */ - memset(fake_used_mask, 0, sizeof(fake_used_mask)); - fake_pmu.used_mask = fake_used_mask; - - if (!validate_event(&fake_pmu, leader)) - return -EINVAL; - - list_for_each_entry(sibling, &leader->sibling_list, group_entry) { - if (!validate_event(&fake_pmu, sibling)) - return -EINVAL; - } - - if (!validate_event(&fake_pmu, event)) - return -EINVAL; - - return 0; -} - -static irqreturn_t armpmu_platform_irq(int irq, void *dev) -{ - struct arm_pmu *armpmu = (struct arm_pmu *) dev; - struct platform_device *plat_device = armpmu->plat_device; - struct arm_pmu_platdata *plat = dev_get_platdata(&plat_device->dev); - - return plat->handle_irq(irq, dev, armpmu->handle_irq); -} - -static void -armpmu_release_hardware(struct arm_pmu *armpmu) -{ - int i, irq, irqs; - struct platform_device *pmu_device = armpmu->plat_device; - struct arm_pmu_platdata *plat = - dev_get_platdata(&pmu_device->dev); - - irqs = min(pmu_device->num_resources, num_possible_cpus()); - - for (i = 0; i < irqs; ++i) { - if (!cpumask_test_and_clear_cpu(i, &armpmu->active_irqs)) - continue; - irq = platform_get_irq(pmu_device, i); - if (irq >= 0) { - if (plat && plat->disable_irq) - plat->disable_irq(irq); - free_irq(irq, armpmu); - } - } - - release_pmu(armpmu->type); -} - -static int -armpmu_reserve_hardware(struct arm_pmu *armpmu) -{ - struct arm_pmu_platdata *plat; - irq_handler_t handle_irq; - int i, err, irq, irqs; - struct platform_device *pmu_device = armpmu->plat_device; - - if (!pmu_device) - return -ENODEV; - - err = reserve_pmu(armpmu->type); - if (err) { - pr_warning("unable to reserve pmu\n"); - return err; - } - - plat = dev_get_platdata(&pmu_device->dev); - if (plat && plat->handle_irq) - handle_irq = armpmu_platform_irq; - else - handle_irq = armpmu->handle_irq; - - irqs = min(pmu_device->num_resources, num_possible_cpus()); - if (irqs < 1) { - pr_err("no irqs for PMUs defined\n"); - return -ENODEV; - } - - for (i = 0; i < irqs; ++i) { - err = 0; - irq = platform_get_irq(pmu_device, i); - if (irq < 0) - continue; - - /* - * If we have a single PMU interrupt that we can't shift, - * assume that we're running on a uniprocessor machine and - * continue. Otherwise, continue without this interrupt. - */ - if (irq_set_affinity(irq, cpumask_of(i)) && irqs > 1) { - pr_warning("unable to set irq affinity (irq=%d, cpu=%u)\n", - irq, i); - continue; - } - - err = request_irq(irq, handle_irq, - IRQF_DISABLED | IRQF_NOBALANCING, - "arm-pmu", armpmu); - if (err) { - pr_err("unable to request IRQ%d for ARM PMU counters\n", - irq); - armpmu_release_hardware(armpmu); - return err; - } else if (plat && plat->enable_irq) - plat->enable_irq(irq); - - cpumask_set_cpu(i, &armpmu->active_irqs); - } - - return 0; -} - -static void -hw_perf_event_destroy(struct perf_event *event) -{ - struct arm_pmu *armpmu = to_arm_pmu(event->pmu); - atomic_t *active_events = &armpmu->active_events; - struct mutex *pmu_reserve_mutex = &armpmu->reserve_mutex; - - if (atomic_dec_and_mutex_lock(active_events, pmu_reserve_mutex)) { - armpmu_release_hardware(armpmu); - mutex_unlock(pmu_reserve_mutex); - } -} - -static int -event_requires_mode_exclusion(struct perf_event_attr *attr) -{ - return attr->exclude_idle || attr->exclude_user || - attr->exclude_kernel || attr->exclude_hv; -} - -static int -__hw_perf_event_init(struct perf_event *event) -{ - struct arm_pmu *armpmu = to_arm_pmu(event->pmu); - struct hw_perf_event *hwc = &event->hw; - int mapping, err; - - mapping = armpmu->map_event(event); - - if (mapping < 0) { - pr_debug("event %x:%llx not supported\n", event->attr.type, - event->attr.config); - return mapping; - } - - /* - * We don't assign an index until we actually place the event onto - * hardware. Use -1 to signify that we haven't decided where to put it - * yet. For SMP systems, each core has it's own PMU so we can't do any - * clever allocation or constraints checking at this point. - */ - hwc->idx = -1; - hwc->config_base = 0; - hwc->config = 0; - hwc->event_base = 0; - - /* - * Check whether we need to exclude the counter from certain modes. - */ - if ((!armpmu->set_event_filter || - armpmu->set_event_filter(hwc, &event->attr)) && - event_requires_mode_exclusion(&event->attr)) { - pr_debug("ARM performance counters do not support " - "mode exclusion\n"); - return -EPERM; - } - - /* - * Store the event encoding into the config_base field. - */ - hwc->config_base |= (unsigned long)mapping; - - if (!hwc->sample_period) { - /* - * For non-sampling runs, limit the sample_period to half - * of the counter width. That way, the new counter value - * is far less likely to overtake the previous one unless - * you have some serious IRQ latency issues. - */ - hwc->sample_period = armpmu->max_period >> 1; - hwc->last_period = hwc->sample_period; - local64_set(&hwc->period_left, hwc->sample_period); - } - - err = 0; - if (event->group_leader != event) { - err = validate_group(event); - if (err) - return -EINVAL; - } - - return err; -} - -static int armpmu_event_init(struct perf_event *event) -{ - struct arm_pmu *armpmu = to_arm_pmu(event->pmu); - int err = 0; - atomic_t *active_events = &armpmu->active_events; - - /* does not support taken branch sampling */ - if (has_branch_stack(event)) - return -EOPNOTSUPP; - - if (armpmu->map_event(event) == -ENOENT) - return -ENOENT; - - event->destroy = hw_perf_event_destroy; - - if (!atomic_inc_not_zero(active_events)) { - mutex_lock(&armpmu->reserve_mutex); - if (atomic_read(active_events) == 0) - err = armpmu_reserve_hardware(armpmu); - - if (!err) - atomic_inc(active_events); - mutex_unlock(&armpmu->reserve_mutex); - } - - if (err) - return err; - - err = __hw_perf_event_init(event); - if (err) - hw_perf_event_destroy(event); - - return err; -} - -static void armpmu_enable(struct pmu *pmu) -{ - struct arm_pmu *armpmu = to_arm_pmu(pmu); - struct pmu_hw_events *hw_events = armpmu->get_hw_events(); - int enabled = bitmap_weight(hw_events->used_mask, armpmu->num_events); - - if (enabled) - armpmu->start(); -} - -static void armpmu_disable(struct pmu *pmu) -{ - struct arm_pmu *armpmu = to_arm_pmu(pmu); - armpmu->stop(); -} - -static void __init armpmu_init(struct arm_pmu *armpmu) -{ - atomic_set(&armpmu->active_events, 0); - mutex_init(&armpmu->reserve_mutex); - - armpmu->pmu = (struct pmu) { - .pmu_enable = armpmu_enable, - .pmu_disable = armpmu_disable, - .event_init = armpmu_event_init, - .add = armpmu_add, - .del = armpmu_del, - .start = armpmu_start, - .stop = armpmu_stop, - .read = armpmu_read, - }; -} - -int __init armpmu_register(struct arm_pmu *armpmu, char *name, int type) -{ - armpmu_init(armpmu); - return perf_pmu_register(&armpmu->pmu, name, type); -} - -/* Include the PMU-specific implementations. */ -#include "perf_event_xscale.c" -#include "perf_event_v6.c" -#include "perf_event_v7.c" - -/* - * Ensure the PMU has sane values out of reset. - * This requires SMP to be available, so exists as a separate initcall. - */ -static int __init -cpu_pmu_reset(void) -{ - if (cpu_pmu && cpu_pmu->reset) - return on_each_cpu(cpu_pmu->reset, NULL, 1); - return 0; -} -arch_initcall(cpu_pmu_reset); - -/* - * PMU platform driver and devicetree bindings. - */ -static struct of_device_id armpmu_of_device_ids[] = { - {.compatible = "arm,cortex-a9-pmu"}, - {.compatible = "arm,cortex-a8-pmu"}, - {.compatible = "arm,arm1136-pmu"}, - {.compatible = "arm,arm1176-pmu"}, - {}, -}; - -static struct platform_device_id armpmu_plat_device_ids[] = { - {.name = "arm-pmu"}, - {}, -}; - -static int __devinit armpmu_device_probe(struct platform_device *pdev) -{ - if (!cpu_pmu) - return -ENODEV; - - cpu_pmu->plat_device = pdev; - return 0; -} - -static struct platform_driver armpmu_driver = { - .driver = { - .name = "arm-pmu", - .of_match_table = armpmu_of_device_ids, - }, - .probe = armpmu_device_probe, - .id_table = armpmu_plat_device_ids, -}; - -static int __init register_pmu_driver(void) -{ - return platform_driver_register(&armpmu_driver); -} -device_initcall(register_pmu_driver); - -static struct pmu_hw_events *armpmu_get_cpu_events(void) -{ - return &__get_cpu_var(cpu_hw_events); -} - -static void __init cpu_pmu_init(struct arm_pmu *armpmu) -{ - int cpu; - for_each_possible_cpu(cpu) { - struct pmu_hw_events *events = &per_cpu(cpu_hw_events, cpu); - events->events = per_cpu(hw_events, cpu); - events->used_mask = per_cpu(used_mask, cpu); - raw_spin_lock_init(&events->pmu_lock); - } - armpmu->get_hw_events = armpmu_get_cpu_events; - armpmu->type = ARM_PMU_DEVICE_CPU; -} - -/* - * PMU hardware loses all context when a CPU goes offline. - * When a CPU is hotplugged back in, since some hardware registers are - * UNKNOWN at reset, the PMU must be explicitly reset to avoid reading - * junk values out of them. - */ -static int __cpuinit pmu_cpu_notify(struct notifier_block *b, - unsigned long action, void *hcpu) -{ - if ((action & ~CPU_TASKS_FROZEN) != CPU_STARTING) - return NOTIFY_DONE; - - if (cpu_pmu && cpu_pmu->reset) - cpu_pmu->reset(NULL); - - return NOTIFY_OK; -} - -static struct notifier_block __cpuinitdata pmu_cpu_notifier = { - .notifier_call = pmu_cpu_notify, -}; - -/* - * CPU PMU identification and registration. - */ -static int __init -init_hw_perf_events(void) -{ - unsigned long cpuid = read_cpuid_id(); - unsigned long implementor = (cpuid & 0xFF000000) >> 24; - unsigned long part_number = (cpuid & 0xFFF0); - - /* ARM Ltd CPUs. */ - if (0x41 == implementor) { - switch (part_number) { - case 0xB360: /* ARM1136 */ - case 0xB560: /* ARM1156 */ - case 0xB760: /* ARM1176 */ - cpu_pmu = armv6pmu_init(); - break; - case 0xB020: /* ARM11mpcore */ - cpu_pmu = armv6mpcore_pmu_init(); - break; - case 0xC080: /* Cortex-A8 */ - cpu_pmu = armv7_a8_pmu_init(); - break; - case 0xC090: /* Cortex-A9 */ - cpu_pmu = armv7_a9_pmu_init(); - break; - case 0xC050: /* Cortex-A5 */ - cpu_pmu = armv7_a5_pmu_init(); - break; - case 0xC0F0: /* Cortex-A15 */ - cpu_pmu = armv7_a15_pmu_init(); - break; - case 0xC070: /* Cortex-A7 */ - cpu_pmu = armv7_a7_pmu_init(); - break; - } - /* Intel CPUs [xscale]. */ - } else if (0x69 == implementor) { - part_number = (cpuid >> 13) & 0x7; - switch (part_number) { - case 1: - cpu_pmu = xscale1pmu_init(); - break; - case 2: - cpu_pmu = xscale2pmu_init(); - break; - } - } - - if (cpu_pmu) { - pr_info("enabled with %s PMU driver, %d counters available\n", - cpu_pmu->name, cpu_pmu->num_events); - cpu_pmu_init(cpu_pmu); - register_cpu_notifier(&pmu_cpu_notifier); - armpmu_register(cpu_pmu, "cpu", PERF_TYPE_RAW); - } else { - pr_info("no hardware support available\n"); - } - - return 0; -} -early_initcall(init_hw_perf_events); - -/* - * Callchain handling code. - */ - -/* - * The registers we're interested in are at the end of the variable - * length saved register structure. The fp points at the end of this - * structure so the address of this struct is: - * (struct frame_tail *)(xxx->fp)-1 - * - * This code has been adapted from the ARM OProfile support. - */ -struct frame_tail { - struct frame_tail __user *fp; - unsigned long sp; - unsigned long lr; -} __attribute__((packed)); - -/* - * Get the return address for a single stackframe and return a pointer to the - * next frame tail. - */ -static struct frame_tail __user * -user_backtrace(struct frame_tail __user *tail, - struct perf_callchain_entry *entry) -{ - struct frame_tail buftail; - - /* Also check accessibility of one struct frame_tail beyond */ - if (!access_ok(VERIFY_READ, tail, sizeof(buftail))) - return NULL; - if (__copy_from_user_inatomic(&buftail, tail, sizeof(buftail))) - return NULL; - - perf_callchain_store(entry, buftail.lr); - - /* - * Frame pointers should strictly progress back up the stack - * (towards higher addresses). - */ - if (tail + 1 >= buftail.fp) - return NULL; - - return buftail.fp - 1; -} - -void -perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs) -{ - struct frame_tail __user *tail; - - - tail = (struct frame_tail __user *)regs->ARM_fp - 1; - - while ((entry->nr < PERF_MAX_STACK_DEPTH) && - tail && !((unsigned long)tail & 0x3)) - tail = user_backtrace(tail, entry); -} - -/* - * Gets called by walk_stackframe() for every stackframe. This will be called - * whist unwinding the stackframe and is like a subroutine return so we use - * the PC. - */ -static int -callchain_trace(struct stackframe *fr, - void *data) -{ - struct perf_callchain_entry *entry = data; - perf_callchain_store(entry, fr->pc); - return 0; -} - -void -perf_callchain_kernel(struct perf_callchain_entry *entry, struct pt_regs *regs) -{ - struct stackframe fr; - - fr.fp = regs->ARM_fp; - fr.sp = regs->ARM_sp; - fr.lr = regs->ARM_lr; - fr.pc = regs->ARM_pc; - walk_stackframe(&fr, callchain_trace, entry); -} |