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-rw-r--r--arch/arc/kernel/perf_event.c326
1 files changed, 326 insertions, 0 deletions
diff --git a/arch/arc/kernel/perf_event.c b/arch/arc/kernel/perf_event.c
new file mode 100644
index 000000000000..e46d81f70979
--- /dev/null
+++ b/arch/arc/kernel/perf_event.c
@@ -0,0 +1,326 @@
+/*
+ * Linux performance counter support for ARC700 series
+ *
+ * Copyright (C) 2013 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This code is inspired by the perf support of various other architectures.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/perf_event.h>
+#include <linux/platform_device.h>
+#include <asm/arcregs.h>
+
+struct arc_pmu {
+ struct pmu pmu;
+ int counter_size; /* in bits */
+ int n_counters;
+ unsigned long used_mask[BITS_TO_LONGS(ARC_PMU_MAX_HWEVENTS)];
+ int ev_hw_idx[PERF_COUNT_ARC_HW_MAX];
+};
+
+/* read counter #idx; note that counter# != event# on ARC! */
+static uint64_t arc_pmu_read_counter(int idx)
+{
+ uint32_t tmp;
+ uint64_t result;
+
+ /*
+ * ARC supports making 'snapshots' of the counters, so we don't
+ * need to care about counters wrapping to 0 underneath our feet
+ */
+ write_aux_reg(ARC_REG_PCT_INDEX, idx);
+ tmp = read_aux_reg(ARC_REG_PCT_CONTROL);
+ write_aux_reg(ARC_REG_PCT_CONTROL, tmp | ARC_REG_PCT_CONTROL_SN);
+ result = (uint64_t) (read_aux_reg(ARC_REG_PCT_SNAPH)) << 32;
+ result |= read_aux_reg(ARC_REG_PCT_SNAPL);
+
+ return result;
+}
+
+static void arc_perf_event_update(struct perf_event *event,
+ struct hw_perf_event *hwc, int idx)
+{
+ struct arc_pmu *arc_pmu = container_of(event->pmu, struct arc_pmu, pmu);
+ 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);
+
+ local64_add(delta, &event->count);
+ local64_sub(delta, &hwc->period_left);
+}
+
+static void arc_pmu_read(struct perf_event *event)
+{
+ arc_perf_event_update(event, &event->hw, event->hw.idx);
+}
+
+static int arc_pmu_cache_event(u64 config)
+{
+ unsigned int cache_type, cache_op, cache_result;
+ int ret;
+
+ cache_type = (config >> 0) & 0xff;
+ cache_op = (config >> 8) & 0xff;
+ cache_result = (config >> 16) & 0xff;
+ if (cache_type >= PERF_COUNT_HW_CACHE_MAX)
+ return -EINVAL;
+ if (cache_type >= PERF_COUNT_HW_CACHE_OP_MAX)
+ return -EINVAL;
+ if (cache_type >= PERF_COUNT_HW_CACHE_RESULT_MAX)
+ return -EINVAL;
+
+ ret = arc_pmu_cache_map[cache_type][cache_op][cache_result];
+
+ if (ret == CACHE_OP_UNSUPPORTED)
+ return -ENOENT;
+
+ return ret;
+}
+
+/* initializes hw_perf_event structure if event is supported */
+static int arc_pmu_event_init(struct perf_event *event)
+{
+ struct arc_pmu *arc_pmu = container_of(event->pmu, struct arc_pmu, pmu);
+ struct hw_perf_event *hwc = &event->hw;
+ int ret;
+
+ /* ARC 700 PMU does not support sampling events */
+ if (is_sampling_event(event))
+ return -ENOENT;
+
+ 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];
+ pr_debug("initializing event %d with cfg %d\n",
+ (int) event->attr.config, (int) hwc->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];
+ return 0;
+ default:
+ return -ENOENT;
+ }
+}
+
+/* starts all counters */
+static void arc_pmu_enable(struct pmu *pmu)
+{
+ uint32_t tmp;
+ tmp = read_aux_reg(ARC_REG_PCT_CONTROL);
+ write_aux_reg(ARC_REG_PCT_CONTROL, (tmp & 0xffff0000) | 0x1);
+}
+
+/* stops all counters */
+static void arc_pmu_disable(struct pmu *pmu)
+{
+ uint32_t tmp;
+ tmp = read_aux_reg(ARC_REG_PCT_CONTROL);
+ write_aux_reg(ARC_REG_PCT_CONTROL, (tmp & 0xffff0000) | 0x0);
+}
+
+/*
+ * Assigns hardware counter to hardware condition.
+ * Note that there is no separate start/stop mechanism;
+ * stopping is achieved by assigning the 'never' condition
+ */
+static void arc_pmu_start(struct perf_event *event, int flags)
+{
+ struct hw_perf_event *hwc = &event->hw;
+ int idx = hwc->idx;
+
+ if (WARN_ON_ONCE(idx == -1))
+ return;
+
+ if (flags & PERF_EF_RELOAD)
+ WARN_ON_ONCE(!(event->hw.state & PERF_HES_UPTODATE));
+
+ event->hw.state = 0;
+
+ /* enable ARC pmu here */
+ write_aux_reg(ARC_REG_PCT_INDEX, idx);
+ write_aux_reg(ARC_REG_PCT_CONFIG, hwc->config);
+}
+
+static void arc_pmu_stop(struct perf_event *event, int flags)
+{
+ struct hw_perf_event *hwc = &event->hw;
+ int idx = hwc->idx;
+
+ if (!(event->hw.state & PERF_HES_STOPPED)) {
+ /* stop ARC pmu here */
+ write_aux_reg(ARC_REG_PCT_INDEX, idx);
+
+ /* condition code #0 is always "never" */
+ write_aux_reg(ARC_REG_PCT_CONFIG, 0);
+
+ event->hw.state |= PERF_HES_STOPPED;
+ }
+
+ if ((flags & PERF_EF_UPDATE) &&
+ !(event->hw.state & PERF_HES_UPTODATE)) {
+ arc_perf_event_update(event, &event->hw, idx);
+ event->hw.state |= PERF_HES_UPTODATE;
+ }
+}
+
+static void arc_pmu_del(struct perf_event *event, int flags)
+{
+ struct arc_pmu *arc_pmu = container_of(event->pmu, struct arc_pmu, pmu);
+
+ arc_pmu_stop(event, PERF_EF_UPDATE);
+ __clear_bit(event->hw.idx, arc_pmu->used_mask);
+
+ 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 *arc_pmu = container_of(event->pmu, struct arc_pmu, pmu);
+ 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,
+ arc_pmu->n_counters);
+ if (idx == arc_pmu->n_counters)
+ return -EAGAIN;
+
+ __set_bit(idx, arc_pmu->used_mask);
+ hwc->idx = idx;
+ }
+
+ write_aux_reg(ARC_REG_PCT_INDEX, idx);
+ write_aux_reg(ARC_REG_PCT_CONFIG, 0);
+ write_aux_reg(ARC_REG_PCT_COUNTL, 0);
+ write_aux_reg(ARC_REG_PCT_COUNTH, 0);
+ local64_set(&hwc->prev_count, 0);
+
+ hwc->state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
+ if (flags & PERF_EF_START)
+ arc_pmu_start(event, PERF_EF_RELOAD);
+
+ perf_event_update_userpage(event);
+
+ return 0;
+}
+
+static int arc_pmu_device_probe(struct platform_device *pdev)
+{
+ struct arc_pmu *arc_pmu;
+ struct arc_reg_pct_build pct_bcr;
+ struct arc_reg_cc_build cc_bcr;
+ int i, j, ret;
+
+ union cc_name {
+ struct {
+ uint32_t word0, word1;
+ char sentinel;
+ } indiv;
+ char str[9];
+ } cc_name;
+
+
+ READ_BCR(ARC_REG_PCT_BUILD, pct_bcr);
+ if (!pct_bcr.v) {
+ pr_err("This core does not have performance counters!\n");
+ return -ENODEV;
+ }
+
+ arc_pmu = devm_kzalloc(&pdev->dev, sizeof(struct arc_pmu),
+ GFP_KERNEL);
+ if (!arc_pmu)
+ return -ENOMEM;
+
+ arc_pmu->n_counters = pct_bcr.c;
+ BUG_ON(arc_pmu->n_counters > ARC_PMU_MAX_HWEVENTS);
+
+ arc_pmu->counter_size = 32 + (pct_bcr.s << 4);
+ pr_info("ARC PMU found with %d counters of size %d bits\n",
+ arc_pmu->n_counters, arc_pmu->counter_size);
+
+ READ_BCR(ARC_REG_CC_BUILD, cc_bcr);
+
+ if (!cc_bcr.v)
+ pr_err("Strange! Performance counters exist, but no countable conditions?\n");
+
+ pr_info("ARC PMU has %d countable conditions\n", cc_bcr.c);
+
+ cc_name.str[8] = 0;
+ for (i = 0; i < PERF_COUNT_HW_MAX; i++)
+ arc_pmu->ev_hw_idx[i] = -1;
+
+ for (j = 0; j < cc_bcr.c; j++) {
+ write_aux_reg(ARC_REG_CC_INDEX, j);
+ cc_name.indiv.word0 = read_aux_reg(ARC_REG_CC_NAME0);
+ cc_name.indiv.word1 = read_aux_reg(ARC_REG_CC_NAME1);
+ for (i = 0; i < ARRAY_SIZE(arc_pmu_ev_hw_map); i++) {
+ if (arc_pmu_ev_hw_map[i] &&
+ !strcmp(arc_pmu_ev_hw_map[i], cc_name.str) &&
+ strlen(arc_pmu_ev_hw_map[i])) {
+ pr_debug("mapping %d to idx %d with name %s\n",
+ i, j, cc_name.str);
+ arc_pmu->ev_hw_idx[i] = j;
+ }
+ }
+ }
+
+ arc_pmu->pmu = (struct pmu) {
+ .pmu_enable = arc_pmu_enable,
+ .pmu_disable = arc_pmu_disable,
+ .event_init = arc_pmu_event_init,
+ .add = arc_pmu_add,
+ .del = arc_pmu_del,
+ .start = arc_pmu_start,
+ .stop = arc_pmu_stop,
+ .read = arc_pmu_read,
+ };
+
+ ret = perf_pmu_register(&arc_pmu->pmu, pdev->name, PERF_TYPE_RAW);
+
+ return ret;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id arc_pmu_match[] = {
+ { .compatible = "snps,arc700-pmu" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, arc_pmu_match);
+#endif
+
+static struct platform_driver arc_pmu_driver = {
+ .driver = {
+ .name = "arc700-pmu",
+ .of_match_table = of_match_ptr(arc_pmu_match),
+ },
+ .probe = arc_pmu_device_probe,
+};
+
+module_platform_driver(arc_pmu_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Mischa Jonker <mjonker@synopsys.com>");
+MODULE_DESCRIPTION("ARC PMU driver");
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