powerpc/perf: Move perf core & PMU code into a subdirectory

The perf code has grown a lot since it started, and is big enough to
warrant its own subdirectory. For reference it's ~60% bigger than the
oprofile code. It declutters the kernel directory, makes it simpler to
grep for "just perf stuff", and allows us to shorten some filenames.

While we're at it, make it more obvious that we have two implementations
of the core perf logic. One for (roughly) Book3S CPUs, which was the
original implementation, and the other for Freescale embedded CPUs.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 688 insertions, 0 deletions

diff --git a/arch/powerpc/perf/core-fsl-emb.c b/arch/powerpc/perf/core-fsl-emb.c
new file mode 100644
index 000000000000..0a6d2a9d569c
--- /dev/null
+++ b/arch/powerpc/perf/core-fsl-emb.c
@@ -0,0 +1,688 @@
+/*
+ * Performance event support - Freescale Embedded Performance Monitor
+ *
+ * Copyright 2008-2009 Paul Mackerras, IBM Corporation.
+ * Copyright 2010 Freescale Semiconductor, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/perf_event.h>
+#include <linux/percpu.h>
+#include <linux/hardirq.h>
+#include <asm/reg_fsl_emb.h>
+#include <asm/pmc.h>
+#include <asm/machdep.h>
+#include <asm/firmware.h>
+#include <asm/ptrace.h>
+
+struct cpu_hw_events {
+	int n_events;
+	int disabled;
+	u8  pmcs_enabled;
+	struct perf_event *event[MAX_HWEVENTS];
+};
+static DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events);
+
+static struct fsl_emb_pmu *ppmu;
+
+/* Number of perf_events counting hardware events */
+static atomic_t num_events;
+/* Used to avoid races in calling reserve/release_pmc_hardware */
+static DEFINE_MUTEX(pmc_reserve_mutex);
+
+/*
+ * If interrupts were soft-disabled when a PMU interrupt occurs, treat
+ * it as an NMI.
+ */
+static inline int perf_intr_is_nmi(struct pt_regs *regs)
+{
+#ifdef __powerpc64__
+	return !regs->softe;
+#else
+	return 0;
+#endif
+}
+
+static void perf_event_interrupt(struct pt_regs *regs);
+
+/*
+ * Read one performance monitor counter (PMC).
+ */
+static unsigned long read_pmc(int idx)
+{
+	unsigned long val;
+
+	switch (idx) {
+	case 0:
+		val = mfpmr(PMRN_PMC0);
+		break;
+	case 1:
+		val = mfpmr(PMRN_PMC1);
+		break;
+	case 2:
+		val = mfpmr(PMRN_PMC2);
+		break;
+	case 3:
+		val = mfpmr(PMRN_PMC3);
+		break;
+	default:
+		printk(KERN_ERR "oops trying to read PMC%d\n", idx);
+		val = 0;
+	}
+	return val;
+}
+
+/*
+ * Write one PMC.
+ */
+static void write_pmc(int idx, unsigned long val)
+{
+	switch (idx) {
+	case 0:
+		mtpmr(PMRN_PMC0, val);
+		break;
+	case 1:
+		mtpmr(PMRN_PMC1, val);
+		break;
+	case 2:
+		mtpmr(PMRN_PMC2, val);
+		break;
+	case 3:
+		mtpmr(PMRN_PMC3, val);
+		break;
+	default:
+		printk(KERN_ERR "oops trying to write PMC%d\n", idx);
+	}
+
+	isync();
+}
+
+/*
+ * Write one local control A register
+ */
+static void write_pmlca(int idx, unsigned long val)
+{
+	switch (idx) {
+	case 0:
+		mtpmr(PMRN_PMLCA0, val);
+		break;
+	case 1:
+		mtpmr(PMRN_PMLCA1, val);
+		break;
+	case 2:
+		mtpmr(PMRN_PMLCA2, val);
+		break;
+	case 3:
+		mtpmr(PMRN_PMLCA3, val);
+		break;
+	default:
+		printk(KERN_ERR "oops trying to write PMLCA%d\n", idx);
+	}
+
+	isync();
+}
+
+/*
+ * Write one local control B register
+ */
+static void write_pmlcb(int idx, unsigned long val)
+{
+	switch (idx) {
+	case 0:
+		mtpmr(PMRN_PMLCB0, val);
+		break;
+	case 1:
+		mtpmr(PMRN_PMLCB1, val);
+		break;
+	case 2:
+		mtpmr(PMRN_PMLCB2, val);
+		break;
+	case 3:
+		mtpmr(PMRN_PMLCB3, val);
+		break;
+	default:
+		printk(KERN_ERR "oops trying to write PMLCB%d\n", idx);
+	}
+
+	isync();
+}
+
+static void fsl_emb_pmu_read(struct perf_event *event)
+{
+	s64 val, delta, prev;
+
+	if (event->hw.state & PERF_HES_STOPPED)
+		return;
+
+	/*
+	 * Performance monitor interrupts come even when interrupts
+	 * are soft-disabled, as long as interrupts are hard-enabled.
+	 * Therefore we treat them like NMIs.
+	 */
+	do {
+		prev = local64_read(&event->hw.prev_count);
+		barrier();
+		val = read_pmc(event->hw.idx);
+	} while (local64_cmpxchg(&event->hw.prev_count, prev, val) != prev);
+
+	/* The counters are only 32 bits wide */
+	delta = (val - prev) & 0xfffffffful;
+	local64_add(delta, &event->count);
+	local64_sub(delta, &event->hw.period_left);
+}
+
+/*
+ * Disable all events to prevent PMU interrupts and to allow
+ * events to be added or removed.
+ */
+static void fsl_emb_pmu_disable(struct pmu *pmu)
+{
+	struct cpu_hw_events *cpuhw;
+	unsigned long flags;
+
+	local_irq_save(flags);
+	cpuhw = &__get_cpu_var(cpu_hw_events);
+
+	if (!cpuhw->disabled) {
+		cpuhw->disabled = 1;
+
+		/*
+		 * Check if we ever enabled the PMU on this cpu.
+		 */
+		if (!cpuhw->pmcs_enabled) {
+			ppc_enable_pmcs();
+			cpuhw->pmcs_enabled = 1;
+		}
+
+		if (atomic_read(&num_events)) {
+			/*
+			 * Set the 'freeze all counters' bit, and disable
+			 * interrupts.  The barrier is to make sure the
+			 * mtpmr has been executed and the PMU has frozen
+			 * the events before we return.
+			 */
+
+			mtpmr(PMRN_PMGC0, PMGC0_FAC);
+			isync();
+		}
+	}
+	local_irq_restore(flags);
+}
+
+/*
+ * Re-enable all events if disable == 0.
+ * If we were previously disabled and events were added, then
+ * put the new config on the PMU.
+ */
+static void fsl_emb_pmu_enable(struct pmu *pmu)
+{
+	struct cpu_hw_events *cpuhw;
+	unsigned long flags;
+
+	local_irq_save(flags);
+	cpuhw = &__get_cpu_var(cpu_hw_events);
+	if (!cpuhw->disabled)
+		goto out;
+
+	cpuhw->disabled = 0;
+	ppc_set_pmu_inuse(cpuhw->n_events != 0);
+
+	if (cpuhw->n_events > 0) {
+		mtpmr(PMRN_PMGC0, PMGC0_PMIE | PMGC0_FCECE);
+		isync();
+	}
+
+ out:
+	local_irq_restore(flags);
+}
+
+static int collect_events(struct perf_event *group, int max_count,
+			  struct perf_event *ctrs[])
+{
+	int n = 0;
+	struct perf_event *event;
+
+	if (!is_software_event(group)) {
+		if (n >= max_count)
+			return -1;
+		ctrs[n] = group;
+		n++;
+	}
+	list_for_each_entry(event, &group->sibling_list, group_entry) {
+		if (!is_software_event(event) &&
+		    event->state != PERF_EVENT_STATE_OFF) {
+			if (n >= max_count)
+				return -1;
+			ctrs[n] = event;
+			n++;
+		}
+	}
+	return n;
+}
+
+/* context locked on entry */
+static int fsl_emb_pmu_add(struct perf_event *event, int flags)
+{
+	struct cpu_hw_events *cpuhw;
+	int ret = -EAGAIN;
+	int num_counters = ppmu->n_counter;
+	u64 val;
+	int i;
+
+	perf_pmu_disable(event->pmu);
+	cpuhw = &get_cpu_var(cpu_hw_events);
+
+	if (event->hw.config & FSL_EMB_EVENT_RESTRICTED)
+		num_counters = ppmu->n_restricted;
+
+	/*
+	 * Allocate counters from top-down, so that restricted-capable
+	 * counters are kept free as long as possible.
+	 */
+	for (i = num_counters - 1; i >= 0; i--) {
+		if (cpuhw->event[i])
+			continue;
+
+		break;
+	}
+
+	if (i < 0)
+		goto out;
+
+	event->hw.idx = i;
+	cpuhw->event[i] = event;
+	++cpuhw->n_events;
+
+	val = 0;
+	if (event->hw.sample_period) {
+		s64 left = local64_read(&event->hw.period_left);
+		if (left < 0x80000000L)
+			val = 0x80000000L - left;
+	}
+	local64_set(&event->hw.prev_count, val);
+
+	if (!(flags & PERF_EF_START)) {
+		event->hw.state = PERF_HES_STOPPED | PERF_HES_UPTODATE;
+		val = 0;
+	}
+
+	write_pmc(i, val);
+	perf_event_update_userpage(event);
+
+	write_pmlcb(i, event->hw.config >> 32);
+	write_pmlca(i, event->hw.config_base);
+
+	ret = 0;
+ out:
+	put_cpu_var(cpu_hw_events);
+	perf_pmu_enable(event->pmu);
+	return ret;
+}
+
+/* context locked on entry */
+static void fsl_emb_pmu_del(struct perf_event *event, int flags)
+{
+	struct cpu_hw_events *cpuhw;
+	int i = event->hw.idx;
+
+	perf_pmu_disable(event->pmu);
+	if (i < 0)
+		goto out;
+
+	fsl_emb_pmu_read(event);
+
+	cpuhw = &get_cpu_var(cpu_hw_events);
+
+	WARN_ON(event != cpuhw->event[event->hw.idx]);
+
+	write_pmlca(i, 0);
+	write_pmlcb(i, 0);
+	write_pmc(i, 0);
+
+	cpuhw->event[i] = NULL;
+	event->hw.idx = -1;
+
+	/*
+	 * TODO: if at least one restricted event exists, and we
+	 * just freed up a non-restricted-capable counter, and
+	 * there is a restricted-capable counter occupied by
+	 * a non-restricted event, migrate that event to the
+	 * vacated counter.
+	 */
+
+	cpuhw->n_events--;
+
+ out:
+	perf_pmu_enable(event->pmu);
+	put_cpu_var(cpu_hw_events);
+}
+
+static void fsl_emb_pmu_start(struct perf_event *event, int ef_flags)
+{
+	unsigned long flags;
+	s64 left;
+
+	if (event->hw.idx < 0 || !event->hw.sample_period)
+		return;
+
+	if (!(event->hw.state & PERF_HES_STOPPED))
+		return;
+
+	if (ef_flags & PERF_EF_RELOAD)
+		WARN_ON_ONCE(!(event->hw.state & PERF_HES_UPTODATE));
+
+	local_irq_save(flags);
+	perf_pmu_disable(event->pmu);
+
+	event->hw.state = 0;
+	left = local64_read(&event->hw.period_left);
+	write_pmc(event->hw.idx, left);
+
+	perf_event_update_userpage(event);
+	perf_pmu_enable(event->pmu);
+	local_irq_restore(flags);
+}
+
+static void fsl_emb_pmu_stop(struct perf_event *event, int ef_flags)
+{
+	unsigned long flags;
+
+	if (event->hw.idx < 0 || !event->hw.sample_period)
+		return;
+
+	if (event->hw.state & PERF_HES_STOPPED)
+		return;
+
+	local_irq_save(flags);
+	perf_pmu_disable(event->pmu);
+
+	fsl_emb_pmu_read(event);
+	event->hw.state |= PERF_HES_STOPPED | PERF_HES_UPTODATE;
+	write_pmc(event->hw.idx, 0);
+
+	perf_event_update_userpage(event);
+	perf_pmu_enable(event->pmu);
+	local_irq_restore(flags);
+}
+
+/*
+ * Release the PMU if this is the last perf_event.
+ */
+static void hw_perf_event_destroy(struct perf_event *event)
+{
+	if (!atomic_add_unless(&num_events, -1, 1)) {
+		mutex_lock(&pmc_reserve_mutex);
+		if (atomic_dec_return(&num_events) == 0)
+			release_pmc_hardware();
+		mutex_unlock(&pmc_reserve_mutex);
+	}
+}
+
+/*
+ * Translate a generic cache event_id config to a raw event_id code.
+ */
+static int hw_perf_cache_event(u64 config, u64 *eventp)
+{
+	unsigned long type, op, result;
+	int ev;
+
+	if (!ppmu->cache_events)
+		return -EINVAL;
+
+	/* unpack config */
+	type = config & 0xff;
+	op = (config >> 8) & 0xff;
+	result = (config >> 16) & 0xff;
+
+	if (type >= PERF_COUNT_HW_CACHE_MAX ||
+	    op >= PERF_COUNT_HW_CACHE_OP_MAX ||
+	    result >= PERF_COUNT_HW_CACHE_RESULT_MAX)
+		return -EINVAL;
+
+	ev = (*ppmu->cache_events)[type][op][result];
+	if (ev == 0)
+		return -EOPNOTSUPP;
+	if (ev == -1)
+		return -EINVAL;
+	*eventp = ev;
+	return 0;
+}
+
+static int fsl_emb_pmu_event_init(struct perf_event *event)
+{
+	u64 ev;
+	struct perf_event *events[MAX_HWEVENTS];
+	int n;
+	int err;
+	int num_restricted;
+	int i;
+
+	switch (event->attr.type) {
+	case PERF_TYPE_HARDWARE:
+		ev = event->attr.config;
+		if (ev >= ppmu->n_generic || ppmu->generic_events[ev] == 0)
+			return -EOPNOTSUPP;
+		ev = ppmu->generic_events[ev];
+		break;
+
+	case PERF_TYPE_HW_CACHE:
+		err = hw_perf_cache_event(event->attr.config, &ev);
+		if (err)
+			return err;
+		break;
+
+	case PERF_TYPE_RAW:
+		ev = event->attr.config;
+		break;
+
+	default:
+		return -ENOENT;
+	}
+
+	event->hw.config = ppmu->xlate_event(ev);
+	if (!(event->hw.config & FSL_EMB_EVENT_VALID))
+		return -EINVAL;
+
+	/*
+	 * If this is in a group, check if it can go on with all the
+	 * other hardware events in the group.  We assume the event
+	 * hasn't been linked into its leader's sibling list at this point.
+	 */
+	n = 0;
+	if (event->group_leader != event) {
+		n = collect_events(event->group_leader,
+		                   ppmu->n_counter - 1, events);
+		if (n < 0)
+			return -EINVAL;
+	}
+
+	if (event->hw.config & FSL_EMB_EVENT_RESTRICTED) {
+		num_restricted = 0;
+		for (i = 0; i < n; i++) {
+			if (events[i]->hw.config & FSL_EMB_EVENT_RESTRICTED)
+				num_restricted++;
+		}
+
+		if (num_restricted >= ppmu->n_restricted)
+			return -EINVAL;
+	}
+
+	event->hw.idx = -1;
+
+	event->hw.config_base = PMLCA_CE | PMLCA_FCM1 |
+	                        (u32)((ev << 16) & PMLCA_EVENT_MASK);
+
+	if (event->attr.exclude_user)
+		event->hw.config_base |= PMLCA_FCU;
+	if (event->attr.exclude_kernel)
+		event->hw.config_base |= PMLCA_FCS;
+	if (event->attr.exclude_idle)
+		return -ENOTSUPP;
+
+	event->hw.last_period = event->hw.sample_period;
+	local64_set(&event->hw.period_left, event->hw.last_period);
+
+	/*
+	 * See if we need to reserve the PMU.
+	 * If no events are currently in use, then we have to take a
+	 * mutex to ensure that we don't race with another task doing
+	 * reserve_pmc_hardware or release_pmc_hardware.
+	 */
+	err = 0;
+	if (!atomic_inc_not_zero(&num_events)) {
+		mutex_lock(&pmc_reserve_mutex);
+		if (atomic_read(&num_events) == 0 &&
+		    reserve_pmc_hardware(perf_event_interrupt))
+			err = -EBUSY;
+		else
+			atomic_inc(&num_events);
+		mutex_unlock(&pmc_reserve_mutex);
+
+		mtpmr(PMRN_PMGC0, PMGC0_FAC);
+		isync();
+	}
+	event->destroy = hw_perf_event_destroy;
+
+	return err;
+}
+
+static struct pmu fsl_emb_pmu = {
+	.pmu_enable	= fsl_emb_pmu_enable,
+	.pmu_disable	= fsl_emb_pmu_disable,
+	.event_init	= fsl_emb_pmu_event_init,
+	.add		= fsl_emb_pmu_add,
+	.del		= fsl_emb_pmu_del,
+	.start		= fsl_emb_pmu_start,
+	.stop		= fsl_emb_pmu_stop,
+	.read		= fsl_emb_pmu_read,
+};
+
+/*
+ * A counter has overflowed; update its count and record
+ * things if requested.  Note that interrupts are hard-disabled
+ * here so there is no possibility of being interrupted.
+ */
+static void record_and_restart(struct perf_event *event, unsigned long val,
+			       struct pt_regs *regs)
+{
+	u64 period = event->hw.sample_period;
+	s64 prev, delta, left;
+	int record = 0;
+
+	if (event->hw.state & PERF_HES_STOPPED) {
+		write_pmc(event->hw.idx, 0);
+		return;
+	}
+
+	/* we don't have to worry about interrupts here */
+	prev = local64_read(&event->hw.prev_count);
+	delta = (val - prev) & 0xfffffffful;
+	local64_add(delta, &event->count);
+
+	/*
+	 * See if the total period for this event has expired,
+	 * and update for the next period.
+	 */
+	val = 0;
+	left = local64_read(&event->hw.period_left) - delta;
+	if (period) {
+		if (left <= 0) {
+			left += period;
+			if (left <= 0)
+				left = period;
+			record = 1;
+			event->hw.last_period = event->hw.sample_period;
+		}
+		if (left < 0x80000000LL)
+			val = 0x80000000LL - left;
+	}
+
+	write_pmc(event->hw.idx, val);
+	local64_set(&event->hw.prev_count, val);
+	local64_set(&event->hw.period_left, left);
+	perf_event_update_userpage(event);
+
+	/*
+	 * Finally record data if requested.
+	 */
+	if (record) {
+		struct perf_sample_data data;
+
+		perf_sample_data_init(&data, 0);
+		data.period = event->hw.last_period;
+
+		if (perf_event_overflow(event, &data, regs))
+			fsl_emb_pmu_stop(event, 0);
+	}
+}
+
+static void perf_event_interrupt(struct pt_regs *regs)
+{
+	int i;
+	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct perf_event *event;
+	unsigned long val;
+	int found = 0;
+	int nmi;
+
+	nmi = perf_intr_is_nmi(regs);
+	if (nmi)
+		nmi_enter();
+	else
+		irq_enter();
+
+	for (i = 0; i < ppmu->n_counter; ++i) {
+		event = cpuhw->event[i];
+
+		val = read_pmc(i);
+		if ((int)val < 0) {
+			if (event) {
+				/* event has overflowed */
+				found = 1;
+				record_and_restart(event, val, regs);
+			} else {
+				/*
+				 * Disabled counter is negative,
+				 * reset it just in case.
+				 */
+				write_pmc(i, 0);
+			}
+		}
+	}
+
+	/* PMM will keep counters frozen until we return from the interrupt. */
+	mtmsr(mfmsr() | MSR_PMM);
+	mtpmr(PMRN_PMGC0, PMGC0_PMIE | PMGC0_FCECE);
+	isync();
+
+	if (nmi)
+		nmi_exit();
+	else
+		irq_exit();
+}
+
+void hw_perf_event_setup(int cpu)
+{
+	struct cpu_hw_events *cpuhw = &per_cpu(cpu_hw_events, cpu);
+
+	memset(cpuhw, 0, sizeof(*cpuhw));
+}
+
+int register_fsl_emb_pmu(struct fsl_emb_pmu *pmu)
+{
+	if (ppmu)
+		return -EBUSY;		/* something's already registered */
+
+	ppmu = pmu;
+	pr_info("%s performance monitor hardware support registered\n",
+		pmu->name);
+
+	perf_pmu_register(&fsl_emb_pmu, "cpu", PERF_TYPE_RAW);
+
+	return 0;
+}