/*
* Linux performance counter support for ARC700 series
*
- * Copyright (C) 2013 Synopsys, Inc. (www.synopsys.com)
+ * Copyright (C) 2013-2015 Synopsys, Inc. (www.synopsys.com)
*
* This code is inspired by the perf support of various other architectures.
*
*
*/
#include <linux/errno.h>
+#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/perf_event.h>
struct arc_pmu {
struct pmu pmu;
- int counter_size; /* in bits */
+ unsigned int irq;
int n_counters;
- unsigned long used_mask[BITS_TO_LONGS(ARC_PMU_MAX_HWEVENTS)];
+ u64 max_period;
int ev_hw_idx[PERF_COUNT_ARC_HW_MAX];
};
+struct arc_pmu_cpu {
+ /*
+ * A 1 bit for an index indicates that the counter is being used for
+ * an event. A 0 means that the counter can be used.
+ */
+ unsigned long used_mask[BITS_TO_LONGS(ARC_PERF_MAX_COUNTERS)];
+
+ /*
+ * The events that are active on the PMU for the given index.
+ */
+ struct perf_event *act_counter[ARC_PERF_MAX_COUNTERS];
+};
+
struct arc_callchain_trace {
int depth;
void *perf_stuff;
}
static struct arc_pmu *arc_pmu;
+static DEFINE_PER_CPU(struct arc_pmu_cpu, arc_pmu_cpu);
/* read counter #idx; note that counter# != event# on ARC! */
static uint64_t arc_pmu_read_counter(int idx)
static void arc_perf_event_update(struct perf_event *event,
struct hw_perf_event *hwc, int idx)
{
- uint64_t prev_raw_count, new_raw_count;
- int64_t delta;
-
- do {
- prev_raw_count = local64_read(&hwc->prev_count);
- new_raw_count = arc_pmu_read_counter(idx);
- } while (local64_cmpxchg(&hwc->prev_count, prev_raw_count,
- new_raw_count) != prev_raw_count);
-
- delta = (new_raw_count - prev_raw_count) &
- ((1ULL << arc_pmu->counter_size) - 1ULL);
+ uint64_t prev_raw_count = local64_read(&hwc->prev_count);
+ uint64_t new_raw_count = arc_pmu_read_counter(idx);
+ int64_t delta = new_raw_count - prev_raw_count;
+ /*
+ * We don't afaraid of hwc->prev_count changing beneath our feet
+ * because there's no way for us to re-enter this function anytime.
+ */
+ local64_set(&hwc->prev_count, new_raw_count);
local64_add(delta, &event->count);
local64_sub(delta, &hwc->period_left);
}
struct hw_perf_event *hwc = &event->hw;
int ret;
+ if (!is_sampling_event(event)) {
+ hwc->sample_period = arc_pmu->max_period;
+ hwc->last_period = hwc->sample_period;
+ local64_set(&hwc->period_left, hwc->sample_period);
+ }
+
+ hwc->config = 0;
+
+ if (is_isa_arcv2()) {
+ /* "exclude user" means "count only kernel" */
+ if (event->attr.exclude_user)
+ hwc->config |= ARC_REG_PCT_CONFIG_KERN;
+
+ /* "exclude kernel" means "count only user" */
+ if (event->attr.exclude_kernel)
+ hwc->config |= ARC_REG_PCT_CONFIG_USER;
+ }
+
switch (event->attr.type) {
case PERF_TYPE_HARDWARE:
if (event->attr.config >= PERF_COUNT_HW_MAX)
return -ENOENT;
if (arc_pmu->ev_hw_idx[event->attr.config] < 0)
return -ENOENT;
- hwc->config = arc_pmu->ev_hw_idx[event->attr.config];
+ hwc->config |= arc_pmu->ev_hw_idx[event->attr.config];
pr_debug("init event %d with h/w %d \'%s\'\n",
(int) event->attr.config, (int) hwc->config,
arc_pmu_ev_hw_map[event->attr.config]);
return 0;
+
case PERF_TYPE_HW_CACHE:
ret = arc_pmu_cache_event(event->attr.config);
if (ret < 0)
return ret;
- hwc->config = arc_pmu->ev_hw_idx[ret];
+ hwc->config |= arc_pmu->ev_hw_idx[ret];
return 0;
default:
return -ENOENT;
write_aux_reg(ARC_REG_PCT_CONTROL, (tmp & 0xffff0000) | 0x0);
}
+static int arc_pmu_event_set_period(struct perf_event *event)
+{
+ struct hw_perf_event *hwc = &event->hw;
+ s64 left = local64_read(&hwc->period_left);
+ s64 period = hwc->sample_period;
+ int idx = hwc->idx;
+ int overflow = 0;
+ u64 value;
+
+ if (unlikely(left <= -period)) {
+ /* left underflowed by more than period. */
+ left = period;
+ local64_set(&hwc->period_left, left);
+ hwc->last_period = period;
+ overflow = 1;
+ } else if (unlikely(left <= 0)) {
+ /* left underflowed by less than period. */
+ left += period;
+ local64_set(&hwc->period_left, left);
+ hwc->last_period = period;
+ overflow = 1;
+ }
+
+ if (left > arc_pmu->max_period)
+ left = arc_pmu->max_period;
+
+ value = arc_pmu->max_period - left;
+ local64_set(&hwc->prev_count, value);
+
+ /* Select counter */
+ write_aux_reg(ARC_REG_PCT_INDEX, idx);
+
+ /* Write value */
+ write_aux_reg(ARC_REG_PCT_COUNTL, (u32)value);
+ write_aux_reg(ARC_REG_PCT_COUNTH, (value >> 32));
+
+ perf_event_update_userpage(event);
+
+ return overflow;
+}
+
/*
* Assigns hardware counter to hardware condition.
* Note that there is no separate start/stop mechanism;
return;
if (flags & PERF_EF_RELOAD)
- WARN_ON_ONCE(!(event->hw.state & PERF_HES_UPTODATE));
+ WARN_ON_ONCE(!(hwc->state & PERF_HES_UPTODATE));
+
+ hwc->state = 0;
- event->hw.state = 0;
+ arc_pmu_event_set_period(event);
+
+ /* Enable interrupt for this counter */
+ if (is_sampling_event(event))
+ write_aux_reg(ARC_REG_PCT_INT_CTRL,
+ read_aux_reg(ARC_REG_PCT_INT_CTRL) | (1 << idx));
/* enable ARC pmu here */
- write_aux_reg(ARC_REG_PCT_INDEX, idx);
- write_aux_reg(ARC_REG_PCT_CONFIG, hwc->config);
+ write_aux_reg(ARC_REG_PCT_INDEX, idx); /* counter # */
+ write_aux_reg(ARC_REG_PCT_CONFIG, hwc->config); /* condition */
}
static void arc_pmu_stop(struct perf_event *event, int flags)
struct hw_perf_event *hwc = &event->hw;
int idx = hwc->idx;
+ /* Disable interrupt for this counter */
+ if (is_sampling_event(event)) {
+ /*
+ * Reset interrupt flag by writing of 1. This is required
+ * to make sure pending interrupt was not left.
+ */
+ write_aux_reg(ARC_REG_PCT_INT_ACT, 1 << idx);
+ write_aux_reg(ARC_REG_PCT_INT_CTRL,
+ read_aux_reg(ARC_REG_PCT_INT_CTRL) & ~(1 << idx));
+ }
+
if (!(event->hw.state & PERF_HES_STOPPED)) {
/* stop ARC pmu here */
write_aux_reg(ARC_REG_PCT_INDEX, idx);
static void arc_pmu_del(struct perf_event *event, int flags)
{
+ struct arc_pmu_cpu *pmu_cpu = this_cpu_ptr(&arc_pmu_cpu);
+
arc_pmu_stop(event, PERF_EF_UPDATE);
- __clear_bit(event->hw.idx, arc_pmu->used_mask);
+ __clear_bit(event->hw.idx, pmu_cpu->used_mask);
+
+ pmu_cpu->act_counter[event->hw.idx] = 0;
perf_event_update_userpage(event);
}
/* allocate hardware counter and optionally start counting */
static int arc_pmu_add(struct perf_event *event, int flags)
{
+ struct arc_pmu_cpu *pmu_cpu = this_cpu_ptr(&arc_pmu_cpu);
struct hw_perf_event *hwc = &event->hw;
int idx = hwc->idx;
- if (__test_and_set_bit(idx, arc_pmu->used_mask)) {
- idx = find_first_zero_bit(arc_pmu->used_mask,
+ if (__test_and_set_bit(idx, pmu_cpu->used_mask)) {
+ idx = find_first_zero_bit(pmu_cpu->used_mask,
arc_pmu->n_counters);
if (idx == arc_pmu->n_counters)
return -EAGAIN;
- __set_bit(idx, arc_pmu->used_mask);
+ __set_bit(idx, pmu_cpu->used_mask);
hwc->idx = idx;
}
write_aux_reg(ARC_REG_PCT_INDEX, idx);
+
+ pmu_cpu->act_counter[idx] = event;
+
+ if (is_sampling_event(event)) {
+ /* Mimic full counter overflow as other arches do */
+ write_aux_reg(ARC_REG_PCT_INT_CNTL, (u32)arc_pmu->max_period);
+ write_aux_reg(ARC_REG_PCT_INT_CNTH,
+ (arc_pmu->max_period >> 32));
+ }
+
write_aux_reg(ARC_REG_PCT_CONFIG, 0);
write_aux_reg(ARC_REG_PCT_COUNTL, 0);
write_aux_reg(ARC_REG_PCT_COUNTH, 0);
return 0;
}
+#ifdef CONFIG_ISA_ARCV2
+static irqreturn_t arc_pmu_intr(int irq, void *dev)
+{
+ struct perf_sample_data data;
+ struct arc_pmu_cpu *pmu_cpu = this_cpu_ptr(&arc_pmu_cpu);
+ struct pt_regs *regs;
+ int active_ints;
+ int idx;
+
+ arc_pmu_disable(&arc_pmu->pmu);
+
+ active_ints = read_aux_reg(ARC_REG_PCT_INT_ACT);
+
+ regs = get_irq_regs();
+
+ for (idx = 0; idx < arc_pmu->n_counters; idx++) {
+ struct perf_event *event = pmu_cpu->act_counter[idx];
+ struct hw_perf_event *hwc;
+
+ if (!(active_ints & (1 << idx)))
+ continue;
+
+ /* Reset interrupt flag by writing of 1 */
+ write_aux_reg(ARC_REG_PCT_INT_ACT, 1 << idx);
+
+ /*
+ * On reset of "interrupt active" bit corresponding
+ * "interrupt enable" bit gets automatically reset as well.
+ * Now we need to re-enable interrupt for the counter.
+ */
+ write_aux_reg(ARC_REG_PCT_INT_CTRL,
+ read_aux_reg(ARC_REG_PCT_INT_CTRL) | (1 << idx));
+
+ hwc = &event->hw;
+
+ WARN_ON_ONCE(hwc->idx != idx);
+
+ arc_perf_event_update(event, &event->hw, event->hw.idx);
+ perf_sample_data_init(&data, 0, hwc->last_period);
+ if (!arc_pmu_event_set_period(event))
+ continue;
+
+ if (perf_event_overflow(event, &data, regs))
+ arc_pmu_stop(event, 0);
+ }
+
+ arc_pmu_enable(&arc_pmu->pmu);
+
+ return IRQ_HANDLED;
+}
+#else
+
+static irqreturn_t arc_pmu_intr(int irq, void *dev)
+{
+ return IRQ_NONE;
+}
+
+#endif /* CONFIG_ISA_ARCV2 */
+
+static void arc_cpu_pmu_irq_init(void *data)
+{
+ int irq = *(int *)data;
+
+ enable_percpu_irq(irq, IRQ_TYPE_NONE);
+
+ /* Clear all pending interrupt flags */
+ write_aux_reg(ARC_REG_PCT_INT_ACT, 0xffffffff);
+}
+
static int arc_pmu_device_probe(struct platform_device *pdev)
{
struct arc_reg_pct_build pct_bcr;
struct arc_reg_cc_build cc_bcr;
- int i, j, ret;
+ int i, j, has_interrupts;
+ int counter_size; /* in bits */
union cc_name {
struct {
pr_err("This core does not have performance counters!\n");
return -ENODEV;
}
- BUG_ON(pct_bcr.c > ARC_PMU_MAX_HWEVENTS);
+ BUG_ON(pct_bcr.c > ARC_PERF_MAX_COUNTERS);
READ_BCR(ARC_REG_CC_BUILD, cc_bcr);
BUG_ON(!cc_bcr.v); /* Counters exist but No countable conditions ? */
if (!arc_pmu)
return -ENOMEM;
+ has_interrupts = is_isa_arcv2() ? pct_bcr.i : 0;
+
arc_pmu->n_counters = pct_bcr.c;
- arc_pmu->counter_size = 32 + (pct_bcr.s << 4);
+ counter_size = 32 + (pct_bcr.s << 4);
+
+ arc_pmu->max_period = (1ULL << counter_size) / 2 - 1ULL;
- pr_info("ARC perf\t: %d counters (%d bits), %d countable conditions\n",
- arc_pmu->n_counters, arc_pmu->counter_size, cc_bcr.c);
+ pr_info("ARC perf\t: %d counters (%d bits), %d conditions%s\n",
+ arc_pmu->n_counters, counter_size, cc_bcr.c,
+ has_interrupts ? ", [overflow IRQ support]":"");
cc_name.str[8] = 0;
for (i = 0; i < PERF_COUNT_ARC_HW_MAX; i++)
.read = arc_pmu_read,
};
- /* ARC 700 PMU does not support sampling events */
- arc_pmu->pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;
+ if (has_interrupts) {
+ int irq = platform_get_irq(pdev, 0);
- ret = perf_pmu_register(&arc_pmu->pmu, pdev->name, PERF_TYPE_RAW);
+ if (irq < 0) {
+ pr_err("Cannot get IRQ number for the platform\n");
+ return -ENODEV;
+ }
- return ret;
+ arc_pmu->irq = irq;
+
+ /* intc map function ensures irq_set_percpu_devid() called */
+ request_percpu_irq(irq, arc_pmu_intr, "ARC perf counters",
+ this_cpu_ptr(&arc_pmu_cpu));
+
+ on_each_cpu(arc_cpu_pmu_irq_init, &irq, 1);
+
+ } else
+ arc_pmu->pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;
+
+ return perf_pmu_register(&arc_pmu->pmu, pdev->name, PERF_TYPE_RAW);
}
#ifdef CONFIG_OF
static const struct of_device_id arc_pmu_match[] = {
{ .compatible = "snps,arc700-pct" },
+ { .compatible = "snps,archs-pct" },
{},
};
MODULE_DEVICE_TABLE(of, arc_pmu_match);
static struct platform_driver arc_pmu_driver = {
.driver = {
- .name = "arc700-pct",
+ .name = "arc-pct",
.of_match_table = of_match_ptr(arc_pmu_match),
},
.probe = arc_pmu_device_probe,
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