--- /dev/null
+/*
+ * Performance event support for s390x - CPU-measurement Counter Facility
+ *
+ * Copyright IBM Corp. 2012
+ * Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License (version 2 only)
+ * as published by the Free Software Foundation.
+ */
+#define KMSG_COMPONENT "cpum_cf"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/kernel_stat.h>
+#include <linux/perf_event.h>
+#include <linux/percpu.h>
+#include <linux/notifier.h>
+#include <linux/init.h>
+#include <linux/export.h>
+#include <asm/system.h>
+#include <asm/irq.h>
+#include <asm/cpu_mf.h>
+
+/* CPU-measurement counter facility supports these CPU counter sets:
+ * For CPU counter sets:
+ * Basic counter set: 0-31
+ * Problem-state counter set: 32-63
+ * Crypto-activity counter set: 64-127
+ * Extented counter set: 128-159
+ */
+enum cpumf_ctr_set {
+ /* CPU counter sets */
+ CPUMF_CTR_SET_BASIC = 0,
+ CPUMF_CTR_SET_USER = 1,
+ CPUMF_CTR_SET_CRYPTO = 2,
+ CPUMF_CTR_SET_EXT = 3,
+
+ /* Maximum number of counter sets */
+ CPUMF_CTR_SET_MAX,
+};
+
+#define CPUMF_LCCTL_ENABLE_SHIFT 16
+#define CPUMF_LCCTL_ACTCTL_SHIFT 0
+static const u64 cpumf_state_ctl[CPUMF_CTR_SET_MAX] = {
+ [CPUMF_CTR_SET_BASIC] = 0x02,
+ [CPUMF_CTR_SET_USER] = 0x04,
+ [CPUMF_CTR_SET_CRYPTO] = 0x08,
+ [CPUMF_CTR_SET_EXT] = 0x01,
+};
+
+static void ctr_set_enable(u64 *state, int ctr_set)
+{
+ *state |= cpumf_state_ctl[ctr_set] << CPUMF_LCCTL_ENABLE_SHIFT;
+}
+static void ctr_set_disable(u64 *state, int ctr_set)
+{
+ *state &= ~(cpumf_state_ctl[ctr_set] << CPUMF_LCCTL_ENABLE_SHIFT);
+}
+static void ctr_set_start(u64 *state, int ctr_set)
+{
+ *state |= cpumf_state_ctl[ctr_set] << CPUMF_LCCTL_ACTCTL_SHIFT;
+}
+static void ctr_set_stop(u64 *state, int ctr_set)
+{
+ *state &= ~(cpumf_state_ctl[ctr_set] << CPUMF_LCCTL_ACTCTL_SHIFT);
+}
+
+/* Local CPUMF event structure */
+struct cpu_hw_events {
+ struct cpumf_ctr_info info;
+ atomic_t ctr_set[CPUMF_CTR_SET_MAX];
+ u64 state, tx_state;
+ unsigned int flags;
+};
+static DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events) = {
+ .ctr_set = {
+ [CPUMF_CTR_SET_BASIC] = ATOMIC_INIT(0),
+ [CPUMF_CTR_SET_USER] = ATOMIC_INIT(0),
+ [CPUMF_CTR_SET_CRYPTO] = ATOMIC_INIT(0),
+ [CPUMF_CTR_SET_EXT] = ATOMIC_INIT(0),
+ },
+ .state = 0,
+ .flags = 0,
+};
+
+static int get_counter_set(u64 event)
+{
+ int set = -1;
+
+ if (event < 32)
+ set = CPUMF_CTR_SET_BASIC;
+ else if (event < 64)
+ set = CPUMF_CTR_SET_USER;
+ else if (event < 128)
+ set = CPUMF_CTR_SET_CRYPTO;
+ else if (event < 160)
+ set = CPUMF_CTR_SET_EXT;
+
+ return set;
+}
+
+static int validate_event(const struct hw_perf_event *hwc)
+{
+ switch (hwc->config_base) {
+ case CPUMF_CTR_SET_BASIC:
+ case CPUMF_CTR_SET_USER:
+ case CPUMF_CTR_SET_CRYPTO:
+ case CPUMF_CTR_SET_EXT:
+ /* check for reserved counters */
+ if ((hwc->config >= 6 && hwc->config <= 31) ||
+ (hwc->config >= 38 && hwc->config <= 63) ||
+ (hwc->config >= 80 && hwc->config <= 127))
+ return -EOPNOTSUPP;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int validate_ctr_version(const struct hw_perf_event *hwc)
+{
+ struct cpu_hw_events *cpuhw;
+ int err = 0;
+
+ cpuhw = &get_cpu_var(cpu_hw_events);
+
+ /* check required version for counter sets */
+ switch (hwc->config_base) {
+ case CPUMF_CTR_SET_BASIC:
+ case CPUMF_CTR_SET_USER:
+ if (cpuhw->info.cfvn < 1)
+ err = -EOPNOTSUPP;
+ break;
+ case CPUMF_CTR_SET_CRYPTO:
+ case CPUMF_CTR_SET_EXT:
+ if (cpuhw->info.csvn < 1)
+ err = -EOPNOTSUPP;
+ break;
+ }
+
+ put_cpu_var(cpu_hw_events);
+ return err;
+}
+
+static int validate_ctr_auth(const struct hw_perf_event *hwc)
+{
+ struct cpu_hw_events *cpuhw;
+ u64 ctrs_state;
+ int err = 0;
+
+ cpuhw = &get_cpu_var(cpu_hw_events);
+
+ /* check authorization for cpu counter sets */
+ ctrs_state = cpumf_state_ctl[hwc->config_base];
+ if (!(ctrs_state & cpuhw->info.auth_ctl))
+ err = -EPERM;
+
+ put_cpu_var(cpu_hw_events);
+ return err;
+}
+
+/*
+ * Change the CPUMF state to active.
+ * Enable and activate the CPU-counter sets according
+ * to the per-cpu control state.
+ */
+static void cpumf_pmu_enable(struct pmu *pmu)
+{
+ struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+ int err;
+
+ if (cpuhw->flags & PMU_F_ENABLED)
+ return;
+
+ err = lcctl(cpuhw->state);
+ if (err) {
+ pr_err("Enabling the performance measuring unit "
+ "failed with rc=%lx\n", err);
+ return;
+ }
+
+ cpuhw->flags |= PMU_F_ENABLED;
+}
+
+/*
+ * Change the CPUMF state to inactive.
+ * Disable and enable (inactive) the CPU-counter sets according
+ * to the per-cpu control state.
+ */
+static void cpumf_pmu_disable(struct pmu *pmu)
+{
+ struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+ int err;
+ u64 inactive;
+
+ if (!(cpuhw->flags & PMU_F_ENABLED))
+ return;
+
+ inactive = cpuhw->state & ~((1 << CPUMF_LCCTL_ENABLE_SHIFT) - 1);
+ err = lcctl(inactive);
+ if (err) {
+ pr_err("Disabling the performance measuring unit "
+ "failed with rc=%lx\n", err);
+ return;
+ }
+
+ cpuhw->flags &= ~PMU_F_ENABLED;
+}
+
+
+/* Number of perf events counting hardware events */
+static atomic_t num_events = ATOMIC_INIT(0);
+/* Used to avoid races in calling reserve/release_cpumf_hardware */
+static DEFINE_MUTEX(pmc_reserve_mutex);
+
+/* CPU-measurement alerts for the counter facility */
+static void cpumf_measurement_alert(struct ext_code ext_code,
+ unsigned int alert, unsigned long unused)
+{
+ struct cpu_hw_events *cpuhw;
+
+ if (!(alert & CPU_MF_INT_CF_MASK))
+ return;
+
+ kstat_cpu(smp_processor_id()).irqs[EXTINT_CPM]++;
+ cpuhw = &__get_cpu_var(cpu_hw_events);
+
+ /* Measurement alerts are shared and might happen when the PMU
+ * is not reserved. Ignore these alerts in this case. */
+ if (!(cpuhw->flags & PMU_F_RESERVED))
+ return;
+
+ /* counter authorization change alert */
+ if (alert & CPU_MF_INT_CF_CACA)
+ qctri(&cpuhw->info);
+
+ /* loss of counter data alert */
+ if (alert & CPU_MF_INT_CF_LCDA)
+ pr_err("CPU[%i] Counter data was lost\n", smp_processor_id());
+}
+
+#define PMC_INIT 0
+#define PMC_RELEASE 1
+static void setup_pmc_cpu(void *flags)
+{
+ struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+
+ switch (*((int *) flags)) {
+ case PMC_INIT:
+ memset(&cpuhw->info, 0, sizeof(cpuhw->info));
+ qctri(&cpuhw->info);
+ cpuhw->flags |= PMU_F_RESERVED;
+ break;
+
+ case PMC_RELEASE:
+ cpuhw->flags &= ~PMU_F_RESERVED;
+ break;
+ }
+
+ /* Disable CPU counter sets */
+ lcctl(0);
+}
+
+/* Initialize the CPU-measurement facility */
+static int reserve_pmc_hardware(void)
+{
+ int flags = PMC_INIT;
+
+ on_each_cpu(setup_pmc_cpu, &flags, 1);
+ measurement_alert_subclass_register();
+
+ return 0;
+}
+
+/* Release the CPU-measurement facility */
+static void release_pmc_hardware(void)
+{
+ int flags = PMC_RELEASE;
+
+ on_each_cpu(setup_pmc_cpu, &flags, 1);
+ measurement_alert_subclass_unregister();
+}
+
+/* Release the PMU if event 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);
+ }
+}
+
+/* CPUMF <-> perf event mappings for kernel+userspace (basic set) */
+static const int cpumf_generic_events_basic[] = {
+ [PERF_COUNT_HW_CPU_CYCLES] = 0,
+ [PERF_COUNT_HW_INSTRUCTIONS] = 1,
+ [PERF_COUNT_HW_CACHE_REFERENCES] = -1,
+ [PERF_COUNT_HW_CACHE_MISSES] = -1,
+ [PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = -1,
+ [PERF_COUNT_HW_BRANCH_MISSES] = -1,
+ [PERF_COUNT_HW_BUS_CYCLES] = -1,
+};
+/* CPUMF <-> perf event mappings for userspace (problem-state set) */
+static const int cpumf_generic_events_user[] = {
+ [PERF_COUNT_HW_CPU_CYCLES] = 32,
+ [PERF_COUNT_HW_INSTRUCTIONS] = 33,
+ [PERF_COUNT_HW_CACHE_REFERENCES] = -1,
+ [PERF_COUNT_HW_CACHE_MISSES] = -1,
+ [PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = -1,
+ [PERF_COUNT_HW_BRANCH_MISSES] = -1,
+ [PERF_COUNT_HW_BUS_CYCLES] = -1,
+};
+
+static int __hw_perf_event_init(struct perf_event *event)
+{
+ struct perf_event_attr *attr = &event->attr;
+ struct hw_perf_event *hwc = &event->hw;
+ int err;
+ u64 ev;
+
+ switch (attr->type) {
+ case PERF_TYPE_RAW:
+ /* Raw events are used to access counters directly,
+ * hence do not permit excludes */
+ if (attr->exclude_kernel || attr->exclude_user ||
+ attr->exclude_hv)
+ return -EOPNOTSUPP;
+ ev = attr->config;
+ break;
+
+ case PERF_TYPE_HARDWARE:
+ ev = attr->config;
+ /* Count user space (problem-state) only */
+ if (!attr->exclude_user && attr->exclude_kernel) {
+ if (ev >= ARRAY_SIZE(cpumf_generic_events_user))
+ return -EOPNOTSUPP;
+ ev = cpumf_generic_events_user[ev];
+
+ /* No support for kernel space counters only */
+ } else if (!attr->exclude_kernel && attr->exclude_user) {
+ return -EOPNOTSUPP;
+
+ /* Count user and kernel space */
+ } else {
+ if (ev >= ARRAY_SIZE(cpumf_generic_events_basic))
+ return -EOPNOTSUPP;
+ ev = cpumf_generic_events_basic[ev];
+ }
+ break;
+
+ default:
+ return -ENOENT;
+ }
+
+ if (ev == -1)
+ return -ENOENT;
+
+ if (ev >= PERF_CPUM_CF_MAX_CTR)
+ return -EINVAL;
+
+ /* The CPU measurement counter facility does not have any interrupts
+ * to do sampling. Sampling must be provided by external means,
+ * for example, by timers.
+ */
+ if (hwc->sample_period)
+ return -EINVAL;
+
+ /* Use the hardware perf event structure to store the counter number
+ * in 'config' member and the counter set to which the counter belongs
+ * in the 'config_base'. The counter set (config_base) is then used
+ * to enable/disable the counters.
+ */
+ hwc->config = ev;
+ hwc->config_base = get_counter_set(ev);
+
+ /* Validate the counter that is assigned to this event.
+ * Because the counter facility can use numerous counters at the
+ * same time without constraints, it is not necessary to explicity
+ * validate event groups (event->group_leader != event).
+ */
+ err = validate_event(hwc);
+ if (err)
+ return err;
+
+ /* Initialize for using the CPU-measurement counter facility */
+ if (!atomic_inc_not_zero(&num_events)) {
+ mutex_lock(&pmc_reserve_mutex);
+ if (atomic_read(&num_events) == 0 && reserve_pmc_hardware())
+ err = -EBUSY;
+ else
+ atomic_inc(&num_events);
+ mutex_unlock(&pmc_reserve_mutex);
+ }
+ event->destroy = hw_perf_event_destroy;
+
+ /* Finally, validate version and authorization of the counter set */
+ err = validate_ctr_auth(hwc);
+ if (!err)
+ err = validate_ctr_version(hwc);
+
+ return err;
+}
+
+static int cpumf_pmu_event_init(struct perf_event *event)
+{
+ int err;
+
+ switch (event->attr.type) {
+ case PERF_TYPE_HARDWARE:
+ case PERF_TYPE_HW_CACHE:
+ case PERF_TYPE_RAW:
+ err = __hw_perf_event_init(event);
+ break;
+ default:
+ return -ENOENT;
+ }
+
+ if (unlikely(err) && event->destroy)
+ event->destroy(event);
+
+ return err;
+}
+
+static int hw_perf_event_reset(struct perf_event *event)
+{
+ u64 prev, new;
+ int err;
+
+ do {
+ prev = local64_read(&event->hw.prev_count);
+ err = ecctr(event->hw.config, &new);
+ if (err) {
+ if (err != 3)
+ break;
+ /* The counter is not (yet) available. This
+ * might happen if the counter set to which
+ * this counter belongs is in the disabled
+ * state.
+ */
+ new = 0;
+ }
+ } while (local64_cmpxchg(&event->hw.prev_count, prev, new) != prev);
+
+ return err;
+}
+
+static int hw_perf_event_update(struct perf_event *event)
+{
+ u64 prev, new, delta;
+ int err;
+
+ do {
+ prev = local64_read(&event->hw.prev_count);
+ err = ecctr(event->hw.config, &new);
+ if (err)
+ goto out;
+ } while (local64_cmpxchg(&event->hw.prev_count, prev, new) != prev);
+
+ delta = (prev <= new) ? new - prev
+ : (-1ULL - prev) + new + 1; /* overflow */
+ local64_add(delta, &event->count);
+out:
+ return err;
+}
+
+static void cpumf_pmu_read(struct perf_event *event)
+{
+ if (event->hw.state & PERF_HES_STOPPED)
+ return;
+
+ hw_perf_event_update(event);
+}
+
+static void cpumf_pmu_start(struct perf_event *event, int flags)
+{
+ struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+ struct hw_perf_event *hwc = &event->hw;
+
+ if (WARN_ON_ONCE(!(hwc->state & PERF_HES_STOPPED)))
+ return;
+
+ if (WARN_ON_ONCE(hwc->config == -1))
+ return;
+
+ if (flags & PERF_EF_RELOAD)
+ WARN_ON_ONCE(!(hwc->state & PERF_HES_UPTODATE));
+
+ hwc->state = 0;
+
+ /* (Re-)enable and activate the counter set */
+ ctr_set_enable(&cpuhw->state, hwc->config_base);
+ ctr_set_start(&cpuhw->state, hwc->config_base);
+
+ /* The counter set to which this counter belongs can be already active.
+ * Because all counters in a set are active, the event->hw.prev_count
+ * needs to be synchronized. At this point, the counter set can be in
+ * the inactive or disabled state.
+ */
+ hw_perf_event_reset(event);
+
+ /* increment refcount for this counter set */
+ atomic_inc(&cpuhw->ctr_set[hwc->config_base]);
+}
+
+static void cpumf_pmu_stop(struct perf_event *event, int flags)
+{
+ struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+ struct hw_perf_event *hwc = &event->hw;
+
+ if (!(hwc->state & PERF_HES_STOPPED)) {
+ /* Decrement reference count for this counter set and if this
+ * is the last used counter in the set, clear activation
+ * control and set the counter set state to inactive.
+ */
+ if (!atomic_dec_return(&cpuhw->ctr_set[hwc->config_base]))
+ ctr_set_stop(&cpuhw->state, hwc->config_base);
+ event->hw.state |= PERF_HES_STOPPED;
+ }
+
+ if ((flags & PERF_EF_UPDATE) && !(hwc->state & PERF_HES_UPTODATE)) {
+ hw_perf_event_update(event);
+ event->hw.state |= PERF_HES_UPTODATE;
+ }
+}
+
+static int cpumf_pmu_add(struct perf_event *event, int flags)
+{
+ struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+
+ /* Check authorization for the counter set to which this
+ * counter belongs.
+ * For group events transaction, the authorization check is
+ * done in cpumf_pmu_commit_txn().
+ */
+ if (!(cpuhw->flags & PERF_EVENT_TXN))
+ if (validate_ctr_auth(&event->hw))
+ return -EPERM;
+
+ ctr_set_enable(&cpuhw->state, event->hw.config_base);
+ event->hw.state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
+
+ if (flags & PERF_EF_START)
+ cpumf_pmu_start(event, PERF_EF_RELOAD);
+
+ perf_event_update_userpage(event);
+
+ return 0;
+}
+
+static void cpumf_pmu_del(struct perf_event *event, int flags)
+{
+ struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+
+ cpumf_pmu_stop(event, PERF_EF_UPDATE);
+
+ /* Check if any counter in the counter set is still used. If not used,
+ * change the counter set to the disabled state. This also clears the
+ * content of all counters in the set.
+ *
+ * When a new perf event has been added but not yet started, this can
+ * clear enable control and resets all counters in a set. Therefore,
+ * cpumf_pmu_start() always has to reenable a counter set.
+ */
+ if (!atomic_read(&cpuhw->ctr_set[event->hw.config_base]))
+ ctr_set_disable(&cpuhw->state, event->hw.config_base);
+
+ perf_event_update_userpage(event);
+}
+
+/*
+ * Start group events scheduling transaction.
+ * Set flags to perform a single test at commit time.
+ */
+static void cpumf_pmu_start_txn(struct pmu *pmu)
+{
+ struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+
+ perf_pmu_disable(pmu);
+ cpuhw->flags |= PERF_EVENT_TXN;
+ cpuhw->tx_state = cpuhw->state;
+}
+
+/*
+ * Stop and cancel a group events scheduling tranctions.
+ * Assumes cpumf_pmu_del() is called for each successful added
+ * cpumf_pmu_add() during the transaction.
+ */
+static void cpumf_pmu_cancel_txn(struct pmu *pmu)
+{
+ struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+
+ WARN_ON(cpuhw->tx_state != cpuhw->state);
+
+ cpuhw->flags &= ~PERF_EVENT_TXN;
+ perf_pmu_enable(pmu);
+}
+
+/*
+ * Commit the group events scheduling transaction. On success, the
+ * transaction is closed. On error, the transaction is kept open
+ * until cpumf_pmu_cancel_txn() is called.
+ */
+static int cpumf_pmu_commit_txn(struct pmu *pmu)
+{
+ struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+ u64 state;
+
+ /* check if the updated state can be scheduled */
+ state = cpuhw->state & ~((1 << CPUMF_LCCTL_ENABLE_SHIFT) - 1);
+ state >>= CPUMF_LCCTL_ENABLE_SHIFT;
+ if ((state & cpuhw->info.auth_ctl) != state)
+ return -EPERM;
+
+ cpuhw->flags &= ~PERF_EVENT_TXN;
+ perf_pmu_enable(pmu);
+ return 0;
+}
+
+/* Performance monitoring unit for s390x */
+static struct pmu cpumf_pmu = {
+ .pmu_enable = cpumf_pmu_enable,
+ .pmu_disable = cpumf_pmu_disable,
+ .event_init = cpumf_pmu_event_init,
+ .add = cpumf_pmu_add,
+ .del = cpumf_pmu_del,
+ .start = cpumf_pmu_start,
+ .stop = cpumf_pmu_stop,
+ .read = cpumf_pmu_read,
+ .start_txn = cpumf_pmu_start_txn,
+ .commit_txn = cpumf_pmu_commit_txn,
+ .cancel_txn = cpumf_pmu_cancel_txn,
+};
+
+static int __cpuinit cpumf_pmu_notifier(struct notifier_block *self,
+ unsigned long action, void *hcpu)
+{
+ unsigned int cpu = (long) hcpu;
+ int flags;
+
+ switch (action & ~CPU_TASKS_FROZEN) {
+ case CPU_ONLINE:
+ flags = PMC_INIT;
+ smp_call_function_single(cpu, setup_pmc_cpu, &flags, 1);
+ break;
+ case CPU_DOWN_PREPARE:
+ flags = PMC_RELEASE;
+ smp_call_function_single(cpu, setup_pmc_cpu, &flags, 1);
+ break;
+ default:
+ break;
+ }
+
+ return NOTIFY_OK;
+}
+
+static int __init cpumf_pmu_init(void)
+{
+ int rc;
+
+ if (!cpum_cf_avail())
+ return -ENODEV;
+
+ /* clear bit 15 of cr0 to unauthorize problem-state to
+ * extract measurement counters */
+ ctl_clear_bit(0, 48);
+
+ /* register handler for measurement-alert interruptions */
+ rc = register_external_interrupt(0x1407, cpumf_measurement_alert);
+ if (rc) {
+ pr_err("Registering for CPU-measurement alerts "
+ "failed with rc=%i\n", rc);
+ goto out;
+ }
+
+ rc = perf_pmu_register(&cpumf_pmu, "cpum_cf", PERF_TYPE_RAW);
+ if (rc) {
+ pr_err("Registering the cpum_cf PMU failed with rc=%i\n", rc);
+ unregister_external_interrupt(0x1407, cpumf_measurement_alert);
+ goto out;
+ }
+ perf_cpu_notifier(cpumf_pmu_notifier);
+out:
+ return rc;
+}
+early_initcall(cpumf_pmu_init);
projects / platform / adaptation / renesas_rcar / renesas_kernel.git / commitdiff