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-rw-r--r--arch/xtensa/Kconfig10
-rw-r--r--arch/xtensa/kernel/Makefile1
-rw-r--r--arch/xtensa/kernel/perf_event.c450
3 files changed, 461 insertions, 0 deletions
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index 66e4043659fe..3bd3504a6cc7 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -128,6 +128,16 @@ config XTENSA_VARIANT_MMU
Build a Conventional Kernel with full MMU support,
ie: it supports a TLB with auto-loading, page protection.
+config XTENSA_VARIANT_HAVE_PERF_EVENTS
+ bool "Core variant has Performance Monitor Module"
+ depends on XTENSA_VARIANT_CUSTOM
+ default n
+ help
+ Enable if core variant has Performance Monitor Module with
+ External Registers Interface.
+
+ If unsure, say N.
+
config XTENSA_UNALIGNED_USER
bool "Unaligned memory access in use space"
help
diff --git a/arch/xtensa/kernel/Makefile b/arch/xtensa/kernel/Makefile
index d3a0f0fd56dd..547a757e6fa2 100644
--- a/arch/xtensa/kernel/Makefile
+++ b/arch/xtensa/kernel/Makefile
@@ -13,6 +13,7 @@ obj-$(CONFIG_PCI) += pci.o
obj-$(CONFIG_MODULES) += xtensa_ksyms.o module.o
obj-$(CONFIG_FUNCTION_TRACER) += mcount.o
obj-$(CONFIG_SMP) += smp.o mxhead.o
+obj-$(CONFIG_XTENSA_VARIANT_HAVE_PERF_EVENTS) += perf_event.o
AFLAGS_head.o += -mtext-section-literals
diff --git a/arch/xtensa/kernel/perf_event.c b/arch/xtensa/kernel/perf_event.c
new file mode 100644
index 000000000000..b44df3c8198f
--- /dev/null
+++ b/arch/xtensa/kernel/perf_event.c
@@ -0,0 +1,450 @@
+/*
+ * Xtensa Performance Monitor Module driver
+ * See Tensilica Debug User's Guide for PMU registers documentation.
+ *
+ * Copyright (C) 2015 Cadence Design Systems Inc.
+ *
+ * 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/interrupt.h>
+#include <linux/irqdomain.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/perf_event.h>
+#include <linux/platform_device.h>
+
+#include <asm/processor.h>
+#include <asm/stacktrace.h>
+
+/* Global control/status for all perf counters */
+#define XTENSA_PMU_PMG 0x1000
+/* Perf counter values */
+#define XTENSA_PMU_PM(i) (0x1080 + (i) * 4)
+/* Perf counter control registers */
+#define XTENSA_PMU_PMCTRL(i) (0x1100 + (i) * 4)
+/* Perf counter status registers */
+#define XTENSA_PMU_PMSTAT(i) (0x1180 + (i) * 4)
+
+#define XTENSA_PMU_PMG_PMEN 0x1
+
+#define XTENSA_PMU_COUNTER_MASK 0xffffffffULL
+#define XTENSA_PMU_COUNTER_MAX 0x7fffffff
+
+#define XTENSA_PMU_PMCTRL_INTEN 0x00000001
+#define XTENSA_PMU_PMCTRL_KRNLCNT 0x00000008
+#define XTENSA_PMU_PMCTRL_TRACELEVEL 0x000000f0
+#define XTENSA_PMU_PMCTRL_SELECT_SHIFT 8
+#define XTENSA_PMU_PMCTRL_SELECT 0x00001f00
+#define XTENSA_PMU_PMCTRL_MASK_SHIFT 16
+#define XTENSA_PMU_PMCTRL_MASK 0xffff0000
+
+#define XTENSA_PMU_MASK(select, mask) \
+ (((select) << XTENSA_PMU_PMCTRL_SELECT_SHIFT) | \
+ ((mask) << XTENSA_PMU_PMCTRL_MASK_SHIFT) | \
+ XTENSA_PMU_PMCTRL_TRACELEVEL | \
+ XTENSA_PMU_PMCTRL_INTEN)
+
+#define XTENSA_PMU_PMSTAT_OVFL 0x00000001
+#define XTENSA_PMU_PMSTAT_INTASRT 0x00000010
+
+struct xtensa_pmu_events {
+ /* Array of events currently on this core */
+ struct perf_event *event[XCHAL_NUM_PERF_COUNTERS];
+ /* Bitmap of used hardware counters */
+ unsigned long used_mask[BITS_TO_LONGS(XCHAL_NUM_PERF_COUNTERS)];
+};
+static DEFINE_PER_CPU(struct xtensa_pmu_events, xtensa_pmu_events);
+
+static const u32 xtensa_hw_ctl[] = {
+ [PERF_COUNT_HW_CPU_CYCLES] = XTENSA_PMU_MASK(0, 0x1),
+ [PERF_COUNT_HW_INSTRUCTIONS] = XTENSA_PMU_MASK(2, 0xffff),
+ [PERF_COUNT_HW_CACHE_REFERENCES] = XTENSA_PMU_MASK(10, 0x1),
+ [PERF_COUNT_HW_CACHE_MISSES] = XTENSA_PMU_MASK(12, 0x1),
+ /* Taken and non-taken branches + taken loop ends */
+ [PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = XTENSA_PMU_MASK(2, 0x490),
+ /* Instruction-related + other global stall cycles */
+ [PERF_COUNT_HW_STALLED_CYCLES_FRONTEND] = XTENSA_PMU_MASK(4, 0x1ff),
+ /* Data-related global stall cycles */
+ [PERF_COUNT_HW_STALLED_CYCLES_BACKEND] = XTENSA_PMU_MASK(3, 0x1ff),
+};
+
+#define C(_x) PERF_COUNT_HW_CACHE_##_x
+
+static const u32 xtensa_cache_ctl[][C(OP_MAX)][C(RESULT_MAX)] = {
+ [C(L1D)] = {
+ [C(OP_READ)] = {
+ [C(RESULT_ACCESS)] = XTENSA_PMU_MASK(10, 0x1),
+ [C(RESULT_MISS)] = XTENSA_PMU_MASK(10, 0x2),
+ },
+ [C(OP_WRITE)] = {
+ [C(RESULT_ACCESS)] = XTENSA_PMU_MASK(11, 0x1),
+ [C(RESULT_MISS)] = XTENSA_PMU_MASK(11, 0x2),
+ },
+ },
+ [C(L1I)] = {
+ [C(OP_READ)] = {
+ [C(RESULT_ACCESS)] = XTENSA_PMU_MASK(8, 0x1),
+ [C(RESULT_MISS)] = XTENSA_PMU_MASK(8, 0x2),
+ },
+ },
+ [C(DTLB)] = {
+ [C(OP_READ)] = {
+ [C(RESULT_ACCESS)] = XTENSA_PMU_MASK(9, 0x1),
+ [C(RESULT_MISS)] = XTENSA_PMU_MASK(9, 0x8),
+ },
+ },
+ [C(ITLB)] = {
+ [C(OP_READ)] = {
+ [C(RESULT_ACCESS)] = XTENSA_PMU_MASK(7, 0x1),
+ [C(RESULT_MISS)] = XTENSA_PMU_MASK(7, 0x8),
+ },
+ },
+};
+
+static int xtensa_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 >= ARRAY_SIZE(xtensa_cache_ctl) ||
+ cache_op >= C(OP_MAX) ||
+ cache_result >= C(RESULT_MAX))
+ return -EINVAL;
+
+ ret = xtensa_cache_ctl[cache_type][cache_op][cache_result];
+
+ if (ret == 0)
+ return -EINVAL;
+
+ return ret;
+}
+
+static inline uint32_t xtensa_pmu_read_counter(int idx)
+{
+ return get_er(XTENSA_PMU_PM(idx));
+}
+
+static inline void xtensa_pmu_write_counter(int idx, uint32_t v)
+{
+ set_er(v, XTENSA_PMU_PM(idx));
+}
+
+static void xtensa_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 = xtensa_pmu_read_counter(event->hw.idx);
+ } while (local64_cmpxchg(&hwc->prev_count, prev_raw_count,
+ new_raw_count) != prev_raw_count);
+
+ delta = (new_raw_count - prev_raw_count) & XTENSA_PMU_COUNTER_MASK;
+
+ local64_add(delta, &event->count);
+ local64_sub(delta, &hwc->period_left);
+}
+
+static bool xtensa_perf_event_set_period(struct perf_event *event,
+ struct hw_perf_event *hwc, int idx)
+{
+ bool rc = false;
+ s64 left;
+
+ if (!is_sampling_event(event)) {
+ left = XTENSA_PMU_COUNTER_MAX;
+ } else {
+ s64 period = hwc->sample_period;
+
+ left = local64_read(&hwc->period_left);
+ if (left <= -period) {
+ left = period;
+ local64_set(&hwc->period_left, left);
+ hwc->last_period = period;
+ rc = true;
+ } else if (left <= 0) {
+ left += period;
+ local64_set(&hwc->period_left, left);
+ hwc->last_period = period;
+ rc = true;
+ }
+ if (left > XTENSA_PMU_COUNTER_MAX)
+ left = XTENSA_PMU_COUNTER_MAX;
+ }
+
+ local64_set(&hwc->prev_count, -left);
+ xtensa_pmu_write_counter(idx, -left);
+ perf_event_update_userpage(event);
+
+ return rc;
+}
+
+static void xtensa_pmu_enable(struct pmu *pmu)
+{
+ set_er(get_er(XTENSA_PMU_PMG) | XTENSA_PMU_PMG_PMEN, XTENSA_PMU_PMG);
+}
+
+static void xtensa_pmu_disable(struct pmu *pmu)
+{
+ set_er(get_er(XTENSA_PMU_PMG) & ~XTENSA_PMU_PMG_PMEN, XTENSA_PMU_PMG);
+}
+
+static int xtensa_pmu_event_init(struct perf_event *event)
+{
+ int ret;
+
+ switch (event->attr.type) {
+ case PERF_TYPE_HARDWARE:
+ if (event->attr.config >= ARRAY_SIZE(xtensa_hw_ctl) ||
+ xtensa_hw_ctl[event->attr.config] == 0)
+ return -EINVAL;
+ event->hw.config = xtensa_hw_ctl[event->attr.config];
+ return 0;
+
+ case PERF_TYPE_HW_CACHE:
+ ret = xtensa_pmu_cache_event(event->attr.config);
+ if (ret < 0)
+ return ret;
+ event->hw.config = ret;
+ return 0;
+
+ case PERF_TYPE_RAW:
+ /* Not 'previous counter' select */
+ if ((event->attr.config & XTENSA_PMU_PMCTRL_SELECT) ==
+ (1 << XTENSA_PMU_PMCTRL_SELECT_SHIFT))
+ return -EINVAL;
+ event->hw.config = (event->attr.config &
+ (XTENSA_PMU_PMCTRL_KRNLCNT |
+ XTENSA_PMU_PMCTRL_TRACELEVEL |
+ XTENSA_PMU_PMCTRL_SELECT |
+ XTENSA_PMU_PMCTRL_MASK)) |
+ XTENSA_PMU_PMCTRL_INTEN;
+ return 0;
+
+ default:
+ return -ENOENT;
+ }
+}
+
+/*
+ * Starts/Stops a counter present on the PMU. The PMI handler
+ * should stop the counter when perf_event_overflow() returns
+ * !0. ->start() will be used to continue.
+ */
+static void xtensa_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));
+ xtensa_perf_event_set_period(event, hwc, idx);
+ }
+
+ hwc->state = 0;
+
+ set_er(hwc->config, XTENSA_PMU_PMCTRL(idx));
+}
+
+static void xtensa_pmu_stop(struct perf_event *event, int flags)
+{
+ struct hw_perf_event *hwc = &event->hw;
+ int idx = hwc->idx;
+
+ if (!(hwc->state & PERF_HES_STOPPED)) {
+ set_er(0, XTENSA_PMU_PMCTRL(idx));
+ set_er(get_er(XTENSA_PMU_PMSTAT(idx)),
+ XTENSA_PMU_PMSTAT(idx));
+ hwc->state |= PERF_HES_STOPPED;
+ }
+
+ if ((flags & PERF_EF_UPDATE) &&
+ !(event->hw.state & PERF_HES_UPTODATE)) {
+ xtensa_perf_event_update(event, &event->hw, idx);
+ event->hw.state |= PERF_HES_UPTODATE;
+ }
+}
+
+/*
+ * Adds/Removes a counter to/from the PMU, can be done inside
+ * a transaction, see the ->*_txn() methods.
+ */
+static int xtensa_pmu_add(struct perf_event *event, int flags)
+{
+ struct xtensa_pmu_events *ev = this_cpu_ptr(&xtensa_pmu_events);
+ struct hw_perf_event *hwc = &event->hw;
+ int idx = hwc->idx;
+
+ if (__test_and_set_bit(idx, ev->used_mask)) {
+ idx = find_first_zero_bit(ev->used_mask,
+ XCHAL_NUM_PERF_COUNTERS);
+ if (idx == XCHAL_NUM_PERF_COUNTERS)
+ return -EAGAIN;
+
+ __set_bit(idx, ev->used_mask);
+ hwc->idx = idx;
+ }
+ ev->event[idx] = event;
+
+ hwc->state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
+
+ if (flags & PERF_EF_START)
+ xtensa_pmu_start(event, PERF_EF_RELOAD);
+
+ perf_event_update_userpage(event);
+ return 0;
+}
+
+static void xtensa_pmu_del(struct perf_event *event, int flags)
+{
+ struct xtensa_pmu_events *ev = this_cpu_ptr(&xtensa_pmu_events);
+
+ xtensa_pmu_stop(event, PERF_EF_UPDATE);
+ __clear_bit(event->hw.idx, ev->used_mask);
+ perf_event_update_userpage(event);
+}
+
+static void xtensa_pmu_read(struct perf_event *event)
+{
+ xtensa_perf_event_update(event, &event->hw, event->hw.idx);
+}
+
+static int callchain_trace(struct stackframe *frame, void *data)
+{
+ struct perf_callchain_entry *entry = data;
+
+ perf_callchain_store(entry, frame->pc);
+ return 0;
+}
+
+void perf_callchain_kernel(struct perf_callchain_entry *entry,
+ struct pt_regs *regs)
+{
+ xtensa_backtrace_kernel(regs, PERF_MAX_STACK_DEPTH,
+ callchain_trace, NULL, entry);
+}
+
+void perf_callchain_user(struct perf_callchain_entry *entry,
+ struct pt_regs *regs)
+{
+ xtensa_backtrace_user(regs, PERF_MAX_STACK_DEPTH,
+ callchain_trace, entry);
+}
+
+void perf_event_print_debug(void)
+{
+ unsigned long flags;
+ unsigned i;
+
+ local_irq_save(flags);
+ pr_info("CPU#%d: PMG: 0x%08lx\n", smp_processor_id(),
+ get_er(XTENSA_PMU_PMG));
+ for (i = 0; i < XCHAL_NUM_PERF_COUNTERS; ++i)
+ pr_info("PM%d: 0x%08lx, PMCTRL%d: 0x%08lx, PMSTAT%d: 0x%08lx\n",
+ i, get_er(XTENSA_PMU_PM(i)),
+ i, get_er(XTENSA_PMU_PMCTRL(i)),
+ i, get_er(XTENSA_PMU_PMSTAT(i)));
+ local_irq_restore(flags);
+}
+
+static irqreturn_t xtensa_pmu_irq_handler(int irq, void *dev_id)
+{
+ irqreturn_t rc = IRQ_NONE;
+ struct xtensa_pmu_events *ev = this_cpu_ptr(&xtensa_pmu_events);
+ unsigned i;
+
+ for (i = find_first_bit(ev->used_mask, XCHAL_NUM_PERF_COUNTERS);
+ i < XCHAL_NUM_PERF_COUNTERS;
+ i = find_next_bit(ev->used_mask, XCHAL_NUM_PERF_COUNTERS, i + 1)) {
+ uint32_t v = get_er(XTENSA_PMU_PMSTAT(i));
+ struct perf_event *event = ev->event[i];
+ struct hw_perf_event *hwc = &event->hw;
+ u64 last_period;
+
+ if (!(v & XTENSA_PMU_PMSTAT_OVFL))
+ continue;
+
+ set_er(v, XTENSA_PMU_PMSTAT(i));
+ xtensa_perf_event_update(event, hwc, i);
+ last_period = hwc->last_period;
+ if (xtensa_perf_event_set_period(event, hwc, i)) {
+ struct perf_sample_data data;
+ struct pt_regs *regs = get_irq_regs();
+
+ perf_sample_data_init(&data, 0, last_period);
+ if (perf_event_overflow(event, &data, regs))
+ xtensa_pmu_stop(event, 0);
+ }
+
+ rc = IRQ_HANDLED;
+ }
+ return rc;
+}
+
+static struct pmu xtensa_pmu = {
+ .pmu_enable = xtensa_pmu_enable,
+ .pmu_disable = xtensa_pmu_disable,
+ .event_init = xtensa_pmu_event_init,
+ .add = xtensa_pmu_add,
+ .del = xtensa_pmu_del,
+ .start = xtensa_pmu_start,
+ .stop = xtensa_pmu_stop,
+ .read = xtensa_pmu_read,
+};
+
+static void xtensa_pmu_setup(void)
+{
+ unsigned i;
+
+ set_er(0, XTENSA_PMU_PMG);
+ for (i = 0; i < XCHAL_NUM_PERF_COUNTERS; ++i) {
+ set_er(0, XTENSA_PMU_PMCTRL(i));
+ set_er(get_er(XTENSA_PMU_PMSTAT(i)), XTENSA_PMU_PMSTAT(i));
+ }
+}
+
+static int xtensa_pmu_notifier(struct notifier_block *self,
+ unsigned long action, void *data)
+{
+ switch (action & ~CPU_TASKS_FROZEN) {
+ case CPU_STARTING:
+ xtensa_pmu_setup();
+ break;
+
+ default:
+ break;
+ }
+
+ return NOTIFY_OK;
+}
+
+static int __init xtensa_pmu_init(void)
+{
+ int ret;
+ int irq = irq_create_mapping(NULL, XCHAL_PROFILING_INTERRUPT);
+
+ perf_cpu_notifier(xtensa_pmu_notifier);
+ ret = request_irq(irq, xtensa_pmu_irq_handler, IRQF_PERCPU,
+ "pmu", NULL);
+ if (ret < 0)
+ return ret;
+
+ ret = perf_pmu_register(&xtensa_pmu, "cpu", PERF_TYPE_RAW);
+ if (ret)
+ free_irq(irq, NULL);
+
+ return ret;
+}
+early_initcall(xtensa_pmu_init);