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-rw-r--r--arch/s390/kernel/perf_cpum_cf.c1543
1 files changed, 1543 insertions, 0 deletions
diff --git a/arch/s390/kernel/perf_cpum_cf.c b/arch/s390/kernel/perf_cpum_cf.c
new file mode 100644
index 000000000..28fa80fd6
--- /dev/null
+++ b/arch/s390/kernel/perf_cpum_cf.c
@@ -0,0 +1,1543 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Performance event support for s390x - CPU-measurement Counter Facility
+ *
+ * Copyright IBM Corp. 2012, 2022
+ * Author(s): Hendrik Brueckner <brueckner@linux.ibm.com>
+ * Thomas Richter <tmricht@linux.ibm.com>
+ */
+#define KMSG_COMPONENT "cpum_cf"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/kernel_stat.h>
+#include <linux/percpu.h>
+#include <linux/notifier.h>
+#include <linux/init.h>
+#include <linux/export.h>
+#include <linux/miscdevice.h>
+
+#include <asm/cpu_mcf.h>
+#include <asm/hwctrset.h>
+#include <asm/debug.h>
+
+static unsigned int cfdiag_cpu_speed; /* CPU speed for CF_DIAG trailer */
+static debug_info_t *cf_dbg;
+
+#define CF_DIAG_CTRSET_DEF 0xfeef /* Counter set header mark */
+ /* interval in seconds */
+
+/* Counter sets are stored as data stream in a page sized memory buffer and
+ * exported to user space via raw data attached to the event sample data.
+ * Each counter set starts with an eight byte header consisting of:
+ * - a two byte eye catcher (0xfeef)
+ * - a one byte counter set number
+ * - a two byte counter set size (indicates the number of counters in this set)
+ * - a three byte reserved value (must be zero) to make the header the same
+ * size as a counter value.
+ * All counter values are eight byte in size.
+ *
+ * All counter sets are followed by a 64 byte trailer.
+ * The trailer consists of a:
+ * - flag field indicating valid fields when corresponding bit set
+ * - the counter facility first and second version number
+ * - the CPU speed if nonzero
+ * - the time stamp the counter sets have been collected
+ * - the time of day (TOD) base value
+ * - the machine type.
+ *
+ * The counter sets are saved when the process is prepared to be executed on a
+ * CPU and saved again when the process is going to be removed from a CPU.
+ * The difference of both counter sets are calculated and stored in the event
+ * sample data area.
+ */
+struct cf_ctrset_entry { /* CPU-M CF counter set entry (8 byte) */
+ unsigned int def:16; /* 0-15 Data Entry Format */
+ unsigned int set:16; /* 16-31 Counter set identifier */
+ unsigned int ctr:16; /* 32-47 Number of stored counters */
+ unsigned int res1:16; /* 48-63 Reserved */
+};
+
+struct cf_trailer_entry { /* CPU-M CF_DIAG trailer (64 byte) */
+ /* 0 - 7 */
+ union {
+ struct {
+ unsigned int clock_base:1; /* TOD clock base set */
+ unsigned int speed:1; /* CPU speed set */
+ /* Measurement alerts */
+ unsigned int mtda:1; /* Loss of MT ctr. data alert */
+ unsigned int caca:1; /* Counter auth. change alert */
+ unsigned int lcda:1; /* Loss of counter data alert */
+ };
+ unsigned long flags; /* 0-63 All indicators */
+ };
+ /* 8 - 15 */
+ unsigned int cfvn:16; /* 64-79 Ctr First Version */
+ unsigned int csvn:16; /* 80-95 Ctr Second Version */
+ unsigned int cpu_speed:32; /* 96-127 CPU speed */
+ /* 16 - 23 */
+ unsigned long timestamp; /* 128-191 Timestamp (TOD) */
+ /* 24 - 55 */
+ union {
+ struct {
+ unsigned long progusage1;
+ unsigned long progusage2;
+ unsigned long progusage3;
+ unsigned long tod_base;
+ };
+ unsigned long progusage[4];
+ };
+ /* 56 - 63 */
+ unsigned int mach_type:16; /* Machine type */
+ unsigned int res1:16; /* Reserved */
+ unsigned int res2:32; /* Reserved */
+};
+
+/* Create the trailer data at the end of a page. */
+static void cfdiag_trailer(struct cf_trailer_entry *te)
+{
+ struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
+ struct cpuid cpuid;
+
+ te->cfvn = cpuhw->info.cfvn; /* Counter version numbers */
+ te->csvn = cpuhw->info.csvn;
+
+ get_cpu_id(&cpuid); /* Machine type */
+ te->mach_type = cpuid.machine;
+ te->cpu_speed = cfdiag_cpu_speed;
+ if (te->cpu_speed)
+ te->speed = 1;
+ te->clock_base = 1; /* Save clock base */
+ te->tod_base = tod_clock_base.tod;
+ te->timestamp = get_tod_clock_fast();
+}
+
+/* Read a counter set. The counter set number determines the counter set and
+ * the CPUM-CF first and second version number determine the number of
+ * available counters in each counter set.
+ * Each counter set starts with header containing the counter set number and
+ * the number of eight byte counters.
+ *
+ * The functions returns the number of bytes occupied by this counter set
+ * including the header.
+ * If there is no counter in the counter set, this counter set is useless and
+ * zero is returned on this case.
+ *
+ * Note that the counter sets may not be enabled or active and the stcctm
+ * instruction might return error 3. Depending on error_ok value this is ok,
+ * for example when called from cpumf_pmu_start() call back function.
+ */
+static size_t cfdiag_getctrset(struct cf_ctrset_entry *ctrdata, int ctrset,
+ size_t room, bool error_ok)
+{
+ struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
+ size_t ctrset_size, need = 0;
+ int rc = 3; /* Assume write failure */
+
+ ctrdata->def = CF_DIAG_CTRSET_DEF;
+ ctrdata->set = ctrset;
+ ctrdata->res1 = 0;
+ ctrset_size = cpum_cf_ctrset_size(ctrset, &cpuhw->info);
+
+ if (ctrset_size) { /* Save data */
+ need = ctrset_size * sizeof(u64) + sizeof(*ctrdata);
+ if (need <= room) {
+ rc = ctr_stcctm(ctrset, ctrset_size,
+ (u64 *)(ctrdata + 1));
+ }
+ if (rc != 3 || error_ok)
+ ctrdata->ctr = ctrset_size;
+ else
+ need = 0;
+ }
+
+ debug_sprintf_event(cf_dbg, 3,
+ "%s ctrset %d ctrset_size %zu cfvn %d csvn %d"
+ " need %zd rc %d\n", __func__, ctrset, ctrset_size,
+ cpuhw->info.cfvn, cpuhw->info.csvn, need, rc);
+ return need;
+}
+
+static const u64 cpumf_ctr_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,
+ [CPUMF_CTR_SET_MT_DIAG] = 0x20,
+};
+
+/* Read out all counter sets and save them in the provided data buffer.
+ * The last 64 byte host an artificial trailer entry.
+ */
+static size_t cfdiag_getctr(void *data, size_t sz, unsigned long auth,
+ bool error_ok)
+{
+ struct cf_trailer_entry *trailer;
+ size_t offset = 0, done;
+ int i;
+
+ memset(data, 0, sz);
+ sz -= sizeof(*trailer); /* Always room for trailer */
+ for (i = CPUMF_CTR_SET_BASIC; i < CPUMF_CTR_SET_MAX; ++i) {
+ struct cf_ctrset_entry *ctrdata = data + offset;
+
+ if (!(auth & cpumf_ctr_ctl[i]))
+ continue; /* Counter set not authorized */
+
+ done = cfdiag_getctrset(ctrdata, i, sz - offset, error_ok);
+ offset += done;
+ }
+ trailer = data + offset;
+ cfdiag_trailer(trailer);
+ return offset + sizeof(*trailer);
+}
+
+/* Calculate the difference for each counter in a counter set. */
+static void cfdiag_diffctrset(u64 *pstart, u64 *pstop, int counters)
+{
+ for (; --counters >= 0; ++pstart, ++pstop)
+ if (*pstop >= *pstart)
+ *pstop -= *pstart;
+ else
+ *pstop = *pstart - *pstop + 1;
+}
+
+/* Scan the counter sets and calculate the difference of each counter
+ * in each set. The result is the increment of each counter during the
+ * period the counter set has been activated.
+ *
+ * Return true on success.
+ */
+static int cfdiag_diffctr(struct cpu_cf_events *cpuhw, unsigned long auth)
+{
+ struct cf_trailer_entry *trailer_start, *trailer_stop;
+ struct cf_ctrset_entry *ctrstart, *ctrstop;
+ size_t offset = 0;
+
+ auth &= (1 << CPUMF_LCCTL_ENABLE_SHIFT) - 1;
+ do {
+ ctrstart = (struct cf_ctrset_entry *)(cpuhw->start + offset);
+ ctrstop = (struct cf_ctrset_entry *)(cpuhw->stop + offset);
+
+ if (memcmp(ctrstop, ctrstart, sizeof(*ctrstop))) {
+ pr_err_once("cpum_cf_diag counter set compare error "
+ "in set %i\n", ctrstart->set);
+ return 0;
+ }
+ auth &= ~cpumf_ctr_ctl[ctrstart->set];
+ if (ctrstart->def == CF_DIAG_CTRSET_DEF) {
+ cfdiag_diffctrset((u64 *)(ctrstart + 1),
+ (u64 *)(ctrstop + 1), ctrstart->ctr);
+ offset += ctrstart->ctr * sizeof(u64) +
+ sizeof(*ctrstart);
+ }
+ } while (ctrstart->def && auth);
+
+ /* Save time_stamp from start of event in stop's trailer */
+ trailer_start = (struct cf_trailer_entry *)(cpuhw->start + offset);
+ trailer_stop = (struct cf_trailer_entry *)(cpuhw->stop + offset);
+ trailer_stop->progusage[0] = trailer_start->timestamp;
+
+ return 1;
+}
+
+static enum cpumf_ctr_set get_counter_set(u64 event)
+{
+ int set = CPUMF_CTR_SET_MAX;
+
+ 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 < 288)
+ set = CPUMF_CTR_SET_EXT;
+ else if (event >= 448 && event < 496)
+ set = CPUMF_CTR_SET_MT_DIAG;
+
+ return set;
+}
+
+static int validate_ctr_version(const struct hw_perf_event *hwc,
+ enum cpumf_ctr_set set)
+{
+ struct cpu_cf_events *cpuhw;
+ int err = 0;
+ u16 mtdiag_ctl;
+
+ cpuhw = &get_cpu_var(cpu_cf_events);
+
+ /* check required version for counter sets */
+ switch (set) {
+ case CPUMF_CTR_SET_BASIC:
+ case CPUMF_CTR_SET_USER:
+ if (cpuhw->info.cfvn < 1)
+ err = -EOPNOTSUPP;
+ break;
+ case CPUMF_CTR_SET_CRYPTO:
+ if ((cpuhw->info.csvn >= 1 && cpuhw->info.csvn <= 5 &&
+ hwc->config > 79) ||
+ (cpuhw->info.csvn >= 6 && hwc->config > 83))
+ err = -EOPNOTSUPP;
+ break;
+ case CPUMF_CTR_SET_EXT:
+ if (cpuhw->info.csvn < 1)
+ err = -EOPNOTSUPP;
+ if ((cpuhw->info.csvn == 1 && hwc->config > 159) ||
+ (cpuhw->info.csvn == 2 && hwc->config > 175) ||
+ (cpuhw->info.csvn >= 3 && cpuhw->info.csvn <= 5
+ && hwc->config > 255) ||
+ (cpuhw->info.csvn >= 6 && hwc->config > 287))
+ err = -EOPNOTSUPP;
+ break;
+ case CPUMF_CTR_SET_MT_DIAG:
+ if (cpuhw->info.csvn <= 3)
+ err = -EOPNOTSUPP;
+ /*
+ * MT-diagnostic counters are read-only. The counter set
+ * is automatically enabled and activated on all CPUs with
+ * multithreading (SMT). Deactivation of multithreading
+ * also disables the counter set. State changes are ignored
+ * by lcctl(). Because Linux controls SMT enablement through
+ * a kernel parameter only, the counter set is either disabled
+ * or enabled and active.
+ *
+ * Thus, the counters can only be used if SMT is on and the
+ * counter set is enabled and active.
+ */
+ mtdiag_ctl = cpumf_ctr_ctl[CPUMF_CTR_SET_MT_DIAG];
+ if (!((cpuhw->info.auth_ctl & mtdiag_ctl) &&
+ (cpuhw->info.enable_ctl & mtdiag_ctl) &&
+ (cpuhw->info.act_ctl & mtdiag_ctl)))
+ err = -EOPNOTSUPP;
+ break;
+ case CPUMF_CTR_SET_MAX:
+ err = -EOPNOTSUPP;
+ }
+
+ put_cpu_var(cpu_cf_events);
+ return err;
+}
+
+static int validate_ctr_auth(const struct hw_perf_event *hwc)
+{
+ struct cpu_cf_events *cpuhw;
+ int err = 0;
+
+ cpuhw = &get_cpu_var(cpu_cf_events);
+
+ /* Check authorization for cpu counter sets.
+ * If the particular CPU counter set is not authorized,
+ * return with -ENOENT in order to fall back to other
+ * PMUs that might suffice the event request.
+ */
+ if (!(hwc->config_base & cpuhw->info.auth_ctl))
+ err = -ENOENT;
+
+ put_cpu_var(cpu_cf_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_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
+ int err;
+
+ if (cpuhw->flags & PMU_F_ENABLED)
+ return;
+
+ err = lcctl(cpuhw->state | cpuhw->dev_state);
+ if (err) {
+ pr_err("Enabling the performance measuring unit "
+ "failed with rc=%x\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_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
+ int err;
+ u64 inactive;
+
+ if (!(cpuhw->flags & PMU_F_ENABLED))
+ return;
+
+ inactive = cpuhw->state & ~((1 << CPUMF_LCCTL_ENABLE_SHIFT) - 1);
+ inactive |= cpuhw->dev_state;
+ err = lcctl(inactive);
+ if (err) {
+ pr_err("Disabling the performance measuring unit "
+ "failed with rc=%x\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);
+
+/* 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)
+ __kernel_cpumcf_end();
+ 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 void cpumf_hw_inuse(void)
+{
+ mutex_lock(&pmc_reserve_mutex);
+ if (atomic_inc_return(&num_events) == 1)
+ __kernel_cpumcf_begin();
+ mutex_unlock(&pmc_reserve_mutex);
+}
+
+static int is_userspace_event(u64 ev)
+{
+ return cpumf_generic_events_user[PERF_COUNT_HW_CPU_CYCLES] == ev ||
+ cpumf_generic_events_user[PERF_COUNT_HW_INSTRUCTIONS] == ev;
+}
+
+static int __hw_perf_event_init(struct perf_event *event, unsigned int type)
+{
+ struct perf_event_attr *attr = &event->attr;
+ struct hw_perf_event *hwc = &event->hw;
+ enum cpumf_ctr_set set;
+ int err = 0;
+ u64 ev;
+
+ switch (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:
+ if (is_sampling_event(event)) /* No sampling support */
+ return -ENOENT;
+ ev = attr->config;
+ if (!attr->exclude_user && attr->exclude_kernel) {
+ /*
+ * Count user space (problem-state) only
+ * Handle events 32 and 33 as 0:u and 1:u
+ */
+ if (!is_userspace_event(ev)) {
+ if (ev >= ARRAY_SIZE(cpumf_generic_events_user))
+ return -EOPNOTSUPP;
+ ev = cpumf_generic_events_user[ev];
+ }
+ } else if (!attr->exclude_kernel && attr->exclude_user) {
+ /* No support for kernel space counters only */
+ return -EOPNOTSUPP;
+ } else {
+ /* Count user and kernel space, incl. events 32 + 33 */
+ if (!is_userspace_event(ev)) {
+ 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 -ENOENT;
+
+ /* Obtain the counter set to which the specified counter belongs */
+ set = get_counter_set(ev);
+ switch (set) {
+ case CPUMF_CTR_SET_BASIC:
+ case CPUMF_CTR_SET_USER:
+ case CPUMF_CTR_SET_CRYPTO:
+ case CPUMF_CTR_SET_EXT:
+ case CPUMF_CTR_SET_MT_DIAG:
+ /*
+ * Use the hardware perf event structure to store the
+ * counter number in the 'config' member and the counter
+ * set number in the 'config_base' as bit mask.
+ * It is later used to enable/disable the counter(s).
+ */
+ hwc->config = ev;
+ hwc->config_base = cpumf_ctr_ctl[set];
+ break;
+ case CPUMF_CTR_SET_MAX:
+ /* The counter could not be associated to a counter set */
+ return -EINVAL;
+ }
+
+ /* Initialize for using the CPU-measurement counter facility */
+ cpumf_hw_inuse();
+ 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, set);
+
+ return err;
+}
+
+/* Events CPU_CYLCES and INSTRUCTIONS can be submitted with two different
+ * attribute::type values:
+ * - PERF_TYPE_HARDWARE:
+ * - pmu->type:
+ * Handle both type of invocations identical. They address the same hardware.
+ * The result is different when event modifiers exclude_kernel and/or
+ * exclude_user are also set.
+ */
+static int cpumf_pmu_event_type(struct perf_event *event)
+{
+ u64 ev = event->attr.config;
+
+ if (cpumf_generic_events_basic[PERF_COUNT_HW_CPU_CYCLES] == ev ||
+ cpumf_generic_events_basic[PERF_COUNT_HW_INSTRUCTIONS] == ev ||
+ cpumf_generic_events_user[PERF_COUNT_HW_CPU_CYCLES] == ev ||
+ cpumf_generic_events_user[PERF_COUNT_HW_INSTRUCTIONS] == ev)
+ return PERF_TYPE_HARDWARE;
+ return PERF_TYPE_RAW;
+}
+
+static int cpumf_pmu_event_init(struct perf_event *event)
+{
+ unsigned int type = event->attr.type;
+ int err;
+
+ if (type == PERF_TYPE_HARDWARE || type == PERF_TYPE_RAW)
+ err = __hw_perf_event_init(event, type);
+ else if (event->pmu->type == type)
+ /* Registered as unknown PMU */
+ err = __hw_perf_event_init(event, cpumf_pmu_event_type(event));
+ else
+ 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 void 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)
+ return;
+ } 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);
+}
+
+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_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
+ struct hw_perf_event *hwc = &event->hw;
+ int i;
+
+ if (!(hwc->state & PERF_HES_STOPPED))
+ return;
+
+ 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.
+ */
+ if (hwc->config == PERF_EVENT_CPUM_CF_DIAG) {
+ cpuhw->usedss = cfdiag_getctr(cpuhw->start,
+ sizeof(cpuhw->start),
+ hwc->config_base, true);
+ } else {
+ hw_perf_event_reset(event);
+ }
+
+ /* Increment refcount for counter sets */
+ for (i = CPUMF_CTR_SET_BASIC; i < CPUMF_CTR_SET_MAX; ++i)
+ if ((hwc->config_base & cpumf_ctr_ctl[i]))
+ atomic_inc(&cpuhw->ctr_set[i]);
+}
+
+/* Create perf event sample with the counter sets as raw data. The sample
+ * is then pushed to the event subsystem and the function checks for
+ * possible event overflows. If an event overflow occurs, the PMU is
+ * stopped.
+ *
+ * Return non-zero if an event overflow occurred.
+ */
+static int cfdiag_push_sample(struct perf_event *event,
+ struct cpu_cf_events *cpuhw)
+{
+ struct perf_sample_data data;
+ struct perf_raw_record raw;
+ struct pt_regs regs;
+ int overflow;
+
+ /* Setup perf sample */
+ perf_sample_data_init(&data, 0, event->hw.last_period);
+ memset(&regs, 0, sizeof(regs));
+ memset(&raw, 0, sizeof(raw));
+
+ if (event->attr.sample_type & PERF_SAMPLE_CPU)
+ data.cpu_entry.cpu = event->cpu;
+ if (event->attr.sample_type & PERF_SAMPLE_RAW) {
+ raw.frag.size = cpuhw->usedss;
+ raw.frag.data = cpuhw->stop;
+ raw.size = raw.frag.size;
+ data.raw = &raw;
+ data.sample_flags |= PERF_SAMPLE_RAW;
+ }
+
+ overflow = perf_event_overflow(event, &data, &regs);
+ debug_sprintf_event(cf_dbg, 3,
+ "%s event %#llx sample_type %#llx raw %d ov %d\n",
+ __func__, event->hw.config,
+ event->attr.sample_type, raw.size, overflow);
+ if (overflow)
+ event->pmu->stop(event, 0);
+
+ perf_event_update_userpage(event);
+ return overflow;
+}
+
+static void cpumf_pmu_stop(struct perf_event *event, int flags)
+{
+ struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
+ struct hw_perf_event *hwc = &event->hw;
+ int i;
+
+ 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.
+ */
+ for (i = CPUMF_CTR_SET_BASIC; i < CPUMF_CTR_SET_MAX; ++i) {
+ if (!(hwc->config_base & cpumf_ctr_ctl[i]))
+ continue;
+ if (!atomic_dec_return(&cpuhw->ctr_set[i]))
+ ctr_set_stop(&cpuhw->state, cpumf_ctr_ctl[i]);
+ }
+ hwc->state |= PERF_HES_STOPPED;
+ }
+
+ if ((flags & PERF_EF_UPDATE) && !(hwc->state & PERF_HES_UPTODATE)) {
+ if (hwc->config == PERF_EVENT_CPUM_CF_DIAG) {
+ local64_inc(&event->count);
+ cpuhw->usedss = cfdiag_getctr(cpuhw->stop,
+ sizeof(cpuhw->stop),
+ event->hw.config_base,
+ false);
+ if (cfdiag_diffctr(cpuhw, event->hw.config_base))
+ cfdiag_push_sample(event, cpuhw);
+ } else if (cpuhw->flags & PMU_F_RESERVED) {
+ /* Only update when PMU not hotplugged off */
+ hw_perf_event_update(event);
+ }
+ hwc->state |= PERF_HES_UPTODATE;
+ }
+}
+
+static int cpumf_pmu_add(struct perf_event *event, int flags)
+{
+ struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
+
+ 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);
+
+ return 0;
+}
+
+static void cpumf_pmu_del(struct perf_event *event, int flags)
+{
+ struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
+ int i;
+
+ 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.
+ */
+ for (i = CPUMF_CTR_SET_BASIC; i < CPUMF_CTR_SET_MAX; ++i)
+ if (!atomic_read(&cpuhw->ctr_set[i]))
+ ctr_set_disable(&cpuhw->state, cpumf_ctr_ctl[i]);
+}
+
+/* Performance monitoring unit for s390x */
+static struct pmu cpumf_pmu = {
+ .task_ctx_nr = perf_sw_context,
+ .capabilities = PERF_PMU_CAP_NO_INTERRUPT,
+ .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,
+};
+
+static int cfset_init(void);
+static int __init cpumf_pmu_init(void)
+{
+ int rc;
+
+ if (!kernel_cpumcf_avail())
+ return -ENODEV;
+
+ /* Setup s390dbf facility */
+ cf_dbg = debug_register(KMSG_COMPONENT, 2, 1, 128);
+ if (!cf_dbg) {
+ pr_err("Registration of s390dbf(cpum_cf) failed\n");
+ return -ENOMEM;
+ }
+ debug_register_view(cf_dbg, &debug_sprintf_view);
+
+ cpumf_pmu.attr_groups = cpumf_cf_event_group();
+ rc = perf_pmu_register(&cpumf_pmu, "cpum_cf", -1);
+ if (rc) {
+ debug_unregister_view(cf_dbg, &debug_sprintf_view);
+ debug_unregister(cf_dbg);
+ pr_err("Registering the cpum_cf PMU failed with rc=%i\n", rc);
+ } else if (stccm_avail()) { /* Setup counter set device */
+ cfset_init();
+ }
+ return rc;
+}
+
+/* Support for the CPU Measurement Facility counter set extraction using
+ * device /dev/hwctr. This allows user space programs to extract complete
+ * counter set via normal file operations.
+ */
+
+static atomic_t cfset_opencnt = ATOMIC_INIT(0); /* Access count */
+static DEFINE_MUTEX(cfset_ctrset_mutex);/* Synchronize access to hardware */
+struct cfset_call_on_cpu_parm { /* Parm struct for smp_call_on_cpu */
+ unsigned int sets; /* Counter set bit mask */
+ atomic_t cpus_ack; /* # CPUs successfully executed func */
+};
+
+static struct cfset_session { /* CPUs and counter set bit mask */
+ struct list_head head; /* Head of list of active processes */
+} cfset_session = {
+ .head = LIST_HEAD_INIT(cfset_session.head)
+};
+
+struct cfset_request { /* CPUs and counter set bit mask */
+ unsigned long ctrset; /* Bit mask of counter set to read */
+ cpumask_t mask; /* CPU mask to read from */
+ struct list_head node; /* Chain to cfset_session.head */
+};
+
+static void cfset_session_init(void)
+{
+ INIT_LIST_HEAD(&cfset_session.head);
+}
+
+/* Remove current request from global bookkeeping. Maintain a counter set bit
+ * mask on a per CPU basis.
+ * Done in process context under mutex protection.
+ */
+static void cfset_session_del(struct cfset_request *p)
+{
+ list_del(&p->node);
+}
+
+/* Add current request to global bookkeeping. Maintain a counter set bit mask
+ * on a per CPU basis.
+ * Done in process context under mutex protection.
+ */
+static void cfset_session_add(struct cfset_request *p)
+{
+ list_add(&p->node, &cfset_session.head);
+}
+
+/* The /dev/hwctr device access uses PMU_F_IN_USE to mark the device access
+ * path is currently used.
+ * The cpu_cf_events::dev_state is used to denote counter sets in use by this
+ * interface. It is always or'ed in. If this interface is not active, its
+ * value is zero and no additional counter sets will be included.
+ *
+ * The cpu_cf_events::state is used by the perf_event_open SVC and remains
+ * unchanged.
+ *
+ * perf_pmu_enable() and perf_pmu_enable() and its call backs
+ * cpumf_pmu_enable() and cpumf_pmu_disable() are called by the
+ * performance measurement subsystem to enable per process
+ * CPU Measurement counter facility.
+ * The XXX_enable() and XXX_disable functions are used to turn off
+ * x86 performance monitoring interrupt (PMI) during scheduling.
+ * s390 uses these calls to temporarily stop and resume the active CPU
+ * counters sets during scheduling.
+ *
+ * We do allow concurrent access of perf_event_open() SVC and /dev/hwctr
+ * device access. The perf_event_open() SVC interface makes a lot of effort
+ * to only run the counters while the calling process is actively scheduled
+ * to run.
+ * When /dev/hwctr interface is also used at the same time, the counter sets
+ * will keep running, even when the process is scheduled off a CPU.
+ * However this is not a problem and does not lead to wrong counter values
+ * for the perf_event_open() SVC. The current counter value will be recorded
+ * during schedule-in. At schedule-out time the current counter value is
+ * extracted again and the delta is calculated and added to the event.
+ */
+/* Stop all counter sets via ioctl interface */
+static void cfset_ioctl_off(void *parm)
+{
+ struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
+ struct cfset_call_on_cpu_parm *p = parm;
+ int rc;
+
+ /* Check if any counter set used by /dev/hwc */
+ for (rc = CPUMF_CTR_SET_BASIC; rc < CPUMF_CTR_SET_MAX; ++rc)
+ if ((p->sets & cpumf_ctr_ctl[rc])) {
+ if (!atomic_dec_return(&cpuhw->ctr_set[rc])) {
+ ctr_set_disable(&cpuhw->dev_state,
+ cpumf_ctr_ctl[rc]);
+ ctr_set_stop(&cpuhw->dev_state,
+ cpumf_ctr_ctl[rc]);
+ }
+ }
+ /* Keep perf_event_open counter sets */
+ rc = lcctl(cpuhw->dev_state | cpuhw->state);
+ if (rc)
+ pr_err("Counter set stop %#llx of /dev/%s failed rc=%i\n",
+ cpuhw->state, S390_HWCTR_DEVICE, rc);
+ if (!cpuhw->dev_state)
+ cpuhw->flags &= ~PMU_F_IN_USE;
+ debug_sprintf_event(cf_dbg, 4, "%s rc %d state %#llx dev_state %#llx\n",
+ __func__, rc, cpuhw->state, cpuhw->dev_state);
+}
+
+/* Start counter sets on particular CPU */
+static void cfset_ioctl_on(void *parm)
+{
+ struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
+ struct cfset_call_on_cpu_parm *p = parm;
+ int rc;
+
+ cpuhw->flags |= PMU_F_IN_USE;
+ ctr_set_enable(&cpuhw->dev_state, p->sets);
+ ctr_set_start(&cpuhw->dev_state, p->sets);
+ for (rc = CPUMF_CTR_SET_BASIC; rc < CPUMF_CTR_SET_MAX; ++rc)
+ if ((p->sets & cpumf_ctr_ctl[rc]))
+ atomic_inc(&cpuhw->ctr_set[rc]);
+ rc = lcctl(cpuhw->dev_state | cpuhw->state); /* Start counter sets */
+ if (!rc)
+ atomic_inc(&p->cpus_ack);
+ else
+ pr_err("Counter set start %#llx of /dev/%s failed rc=%i\n",
+ cpuhw->dev_state | cpuhw->state, S390_HWCTR_DEVICE, rc);
+ debug_sprintf_event(cf_dbg, 4, "%s rc %d state %#llx dev_state %#llx\n",
+ __func__, rc, cpuhw->state, cpuhw->dev_state);
+}
+
+static void cfset_release_cpu(void *p)
+{
+ struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
+ int rc;
+
+ debug_sprintf_event(cf_dbg, 4, "%s state %#llx dev_state %#llx\n",
+ __func__, cpuhw->state, cpuhw->dev_state);
+ cpuhw->dev_state = 0;
+ rc = lcctl(cpuhw->state); /* Keep perf_event_open counter sets */
+ if (rc)
+ pr_err("Counter set release %#llx of /dev/%s failed rc=%i\n",
+ cpuhw->state, S390_HWCTR_DEVICE, rc);
+}
+
+/* This modifies the process CPU mask to adopt it to the currently online
+ * CPUs. Offline CPUs can not be addresses. This call terminates the access
+ * and is usually followed by close() or a new iotcl(..., START, ...) which
+ * creates a new request structure.
+ */
+static void cfset_all_stop(struct cfset_request *req)
+{
+ struct cfset_call_on_cpu_parm p = {
+ .sets = req->ctrset,
+ };
+
+ cpumask_and(&req->mask, &req->mask, cpu_online_mask);
+ on_each_cpu_mask(&req->mask, cfset_ioctl_off, &p, 1);
+}
+
+/* Release function is also called when application gets terminated without
+ * doing a proper ioctl(..., S390_HWCTR_STOP, ...) command.
+ */
+static int cfset_release(struct inode *inode, struct file *file)
+{
+ mutex_lock(&cfset_ctrset_mutex);
+ /* Open followed by close/exit has no private_data */
+ if (file->private_data) {
+ cfset_all_stop(file->private_data);
+ cfset_session_del(file->private_data);
+ kfree(file->private_data);
+ file->private_data = NULL;
+ }
+ if (!atomic_dec_return(&cfset_opencnt))
+ on_each_cpu(cfset_release_cpu, NULL, 1);
+ mutex_unlock(&cfset_ctrset_mutex);
+
+ hw_perf_event_destroy(NULL);
+ return 0;
+}
+
+static int cfset_open(struct inode *inode, struct file *file)
+{
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+ mutex_lock(&cfset_ctrset_mutex);
+ if (atomic_inc_return(&cfset_opencnt) == 1)
+ cfset_session_init();
+ mutex_unlock(&cfset_ctrset_mutex);
+
+ cpumf_hw_inuse();
+ file->private_data = NULL;
+ /* nonseekable_open() never fails */
+ return nonseekable_open(inode, file);
+}
+
+static int cfset_all_start(struct cfset_request *req)
+{
+ struct cfset_call_on_cpu_parm p = {
+ .sets = req->ctrset,
+ .cpus_ack = ATOMIC_INIT(0),
+ };
+ cpumask_var_t mask;
+ int rc = 0;
+
+ if (!alloc_cpumask_var(&mask, GFP_KERNEL))
+ return -ENOMEM;
+ cpumask_and(mask, &req->mask, cpu_online_mask);
+ on_each_cpu_mask(mask, cfset_ioctl_on, &p, 1);
+ if (atomic_read(&p.cpus_ack) != cpumask_weight(mask)) {
+ on_each_cpu_mask(mask, cfset_ioctl_off, &p, 1);
+ rc = -EIO;
+ debug_sprintf_event(cf_dbg, 4, "%s CPUs missing", __func__);
+ }
+ free_cpumask_var(mask);
+ return rc;
+}
+
+
+/* Return the maximum required space for all possible CPUs in case one
+ * CPU will be onlined during the START, READ, STOP cycles.
+ * To find out the size of the counter sets, any one CPU will do. They
+ * all have the same counter sets.
+ */
+static size_t cfset_needspace(unsigned int sets)
+{
+ struct cpu_cf_events *cpuhw = get_cpu_ptr(&cpu_cf_events);
+ size_t bytes = 0;
+ int i;
+
+ for (i = CPUMF_CTR_SET_BASIC; i < CPUMF_CTR_SET_MAX; ++i) {
+ if (!(sets & cpumf_ctr_ctl[i]))
+ continue;
+ bytes += cpum_cf_ctrset_size(i, &cpuhw->info) * sizeof(u64) +
+ sizeof(((struct s390_ctrset_setdata *)0)->set) +
+ sizeof(((struct s390_ctrset_setdata *)0)->no_cnts);
+ }
+ bytes = sizeof(((struct s390_ctrset_read *)0)->no_cpus) + nr_cpu_ids *
+ (bytes + sizeof(((struct s390_ctrset_cpudata *)0)->cpu_nr) +
+ sizeof(((struct s390_ctrset_cpudata *)0)->no_sets));
+ put_cpu_ptr(&cpu_cf_events);
+ return bytes;
+}
+
+static int cfset_all_copy(unsigned long arg, cpumask_t *mask)
+{
+ struct s390_ctrset_read __user *ctrset_read;
+ unsigned int cpu, cpus, rc;
+ void __user *uptr;
+
+ ctrset_read = (struct s390_ctrset_read __user *)arg;
+ uptr = ctrset_read->data;
+ for_each_cpu(cpu, mask) {
+ struct cpu_cf_events *cpuhw = per_cpu_ptr(&cpu_cf_events, cpu);
+ struct s390_ctrset_cpudata __user *ctrset_cpudata;
+
+ ctrset_cpudata = uptr;
+ rc = put_user(cpu, &ctrset_cpudata->cpu_nr);
+ rc |= put_user(cpuhw->sets, &ctrset_cpudata->no_sets);
+ rc |= copy_to_user(ctrset_cpudata->data, cpuhw->data,
+ cpuhw->used);
+ if (rc)
+ return -EFAULT;
+ uptr += sizeof(struct s390_ctrset_cpudata) + cpuhw->used;
+ cond_resched();
+ }
+ cpus = cpumask_weight(mask);
+ if (put_user(cpus, &ctrset_read->no_cpus))
+ return -EFAULT;
+ debug_sprintf_event(cf_dbg, 4, "%s copied %ld\n", __func__,
+ uptr - (void __user *)ctrset_read->data);
+ return 0;
+}
+
+static size_t cfset_cpuset_read(struct s390_ctrset_setdata *p, int ctrset,
+ int ctrset_size, size_t room)
+{
+ size_t need = 0;
+ int rc = -1;
+
+ need = sizeof(*p) + sizeof(u64) * ctrset_size;
+ if (need <= room) {
+ p->set = cpumf_ctr_ctl[ctrset];
+ p->no_cnts = ctrset_size;
+ rc = ctr_stcctm(ctrset, ctrset_size, (u64 *)p->cv);
+ if (rc == 3) /* Nothing stored */
+ need = 0;
+ }
+ return need;
+}
+
+/* Read all counter sets. */
+static void cfset_cpu_read(void *parm)
+{
+ struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
+ struct cfset_call_on_cpu_parm *p = parm;
+ int set, set_size;
+ size_t space;
+
+ /* No data saved yet */
+ cpuhw->used = 0;
+ cpuhw->sets = 0;
+ memset(cpuhw->data, 0, sizeof(cpuhw->data));
+
+ /* Scan the counter sets */
+ for (set = CPUMF_CTR_SET_BASIC; set < CPUMF_CTR_SET_MAX; ++set) {
+ struct s390_ctrset_setdata *sp = (void *)cpuhw->data +
+ cpuhw->used;
+
+ if (!(p->sets & cpumf_ctr_ctl[set]))
+ continue; /* Counter set not in list */
+ set_size = cpum_cf_ctrset_size(set, &cpuhw->info);
+ space = sizeof(cpuhw->data) - cpuhw->used;
+ space = cfset_cpuset_read(sp, set, set_size, space);
+ if (space) {
+ cpuhw->used += space;
+ cpuhw->sets += 1;
+ }
+ }
+ debug_sprintf_event(cf_dbg, 4, "%s sets %d used %zd\n", __func__,
+ cpuhw->sets, cpuhw->used);
+}
+
+static int cfset_all_read(unsigned long arg, struct cfset_request *req)
+{
+ struct cfset_call_on_cpu_parm p;
+ cpumask_var_t mask;
+ int rc;
+
+ if (!alloc_cpumask_var(&mask, GFP_KERNEL))
+ return -ENOMEM;
+
+ p.sets = req->ctrset;
+ cpumask_and(mask, &req->mask, cpu_online_mask);
+ on_each_cpu_mask(mask, cfset_cpu_read, &p, 1);
+ rc = cfset_all_copy(arg, mask);
+ free_cpumask_var(mask);
+ return rc;
+}
+
+static long cfset_ioctl_read(unsigned long arg, struct cfset_request *req)
+{
+ struct s390_ctrset_read read;
+ int ret = -ENODATA;
+
+ if (req && req->ctrset) {
+ if (copy_from_user(&read, (char __user *)arg, sizeof(read)))
+ return -EFAULT;
+ ret = cfset_all_read(arg, req);
+ }
+ return ret;
+}
+
+static long cfset_ioctl_stop(struct file *file)
+{
+ struct cfset_request *req = file->private_data;
+ int ret = -ENXIO;
+
+ if (req) {
+ cfset_all_stop(req);
+ cfset_session_del(req);
+ kfree(req);
+ file->private_data = NULL;
+ ret = 0;
+ }
+ return ret;
+}
+
+static long cfset_ioctl_start(unsigned long arg, struct file *file)
+{
+ struct s390_ctrset_start __user *ustart;
+ struct s390_ctrset_start start;
+ struct cfset_request *preq;
+ void __user *umask;
+ unsigned int len;
+ int ret = 0;
+ size_t need;
+
+ if (file->private_data)
+ return -EBUSY;
+ ustart = (struct s390_ctrset_start __user *)arg;
+ if (copy_from_user(&start, ustart, sizeof(start)))
+ return -EFAULT;
+ if (start.version != S390_HWCTR_START_VERSION)
+ return -EINVAL;
+ if (start.counter_sets & ~(cpumf_ctr_ctl[CPUMF_CTR_SET_BASIC] |
+ cpumf_ctr_ctl[CPUMF_CTR_SET_USER] |
+ cpumf_ctr_ctl[CPUMF_CTR_SET_CRYPTO] |
+ cpumf_ctr_ctl[CPUMF_CTR_SET_EXT] |
+ cpumf_ctr_ctl[CPUMF_CTR_SET_MT_DIAG]))
+ return -EINVAL; /* Invalid counter set */
+ if (!start.counter_sets)
+ return -EINVAL; /* No counter set at all? */
+
+ preq = kzalloc(sizeof(*preq), GFP_KERNEL);
+ if (!preq)
+ return -ENOMEM;
+ cpumask_clear(&preq->mask);
+ len = min_t(u64, start.cpumask_len, cpumask_size());
+ umask = (void __user *)start.cpumask;
+ if (copy_from_user(&preq->mask, umask, len)) {
+ kfree(preq);
+ return -EFAULT;
+ }
+ if (cpumask_empty(&preq->mask)) {
+ kfree(preq);
+ return -EINVAL;
+ }
+ need = cfset_needspace(start.counter_sets);
+ if (put_user(need, &ustart->data_bytes)) {
+ kfree(preq);
+ return -EFAULT;
+ }
+ preq->ctrset = start.counter_sets;
+ ret = cfset_all_start(preq);
+ if (!ret) {
+ cfset_session_add(preq);
+ file->private_data = preq;
+ debug_sprintf_event(cf_dbg, 4, "%s set %#lx need %ld ret %d\n",
+ __func__, preq->ctrset, need, ret);
+ } else {
+ kfree(preq);
+ }
+ return ret;
+}
+
+/* Entry point to the /dev/hwctr device interface.
+ * The ioctl system call supports three subcommands:
+ * S390_HWCTR_START: Start the specified counter sets on a CPU list. The
+ * counter set keeps running until explicitly stopped. Returns the number
+ * of bytes needed to store the counter values. If another S390_HWCTR_START
+ * ioctl subcommand is called without a previous S390_HWCTR_STOP stop
+ * command on the same file descriptor, -EBUSY is returned.
+ * S390_HWCTR_READ: Read the counter set values from specified CPU list given
+ * with the S390_HWCTR_START command.
+ * S390_HWCTR_STOP: Stops the counter sets on the CPU list given with the
+ * previous S390_HWCTR_START subcommand.
+ */
+static long cfset_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ int ret;
+
+ cpus_read_lock();
+ mutex_lock(&cfset_ctrset_mutex);
+ switch (cmd) {
+ case S390_HWCTR_START:
+ ret = cfset_ioctl_start(arg, file);
+ break;
+ case S390_HWCTR_STOP:
+ ret = cfset_ioctl_stop(file);
+ break;
+ case S390_HWCTR_READ:
+ ret = cfset_ioctl_read(arg, file->private_data);
+ break;
+ default:
+ ret = -ENOTTY;
+ break;
+ }
+ mutex_unlock(&cfset_ctrset_mutex);
+ cpus_read_unlock();
+ return ret;
+}
+
+static const struct file_operations cfset_fops = {
+ .owner = THIS_MODULE,
+ .open = cfset_open,
+ .release = cfset_release,
+ .unlocked_ioctl = cfset_ioctl,
+ .compat_ioctl = cfset_ioctl,
+ .llseek = no_llseek
+};
+
+static struct miscdevice cfset_dev = {
+ .name = S390_HWCTR_DEVICE,
+ .minor = MISC_DYNAMIC_MINOR,
+ .fops = &cfset_fops,
+};
+
+/* Hotplug add of a CPU. Scan through all active processes and add
+ * that CPU to the list of CPUs supplied with ioctl(..., START, ...).
+ */
+int cfset_online_cpu(unsigned int cpu)
+{
+ struct cfset_call_on_cpu_parm p;
+ struct cfset_request *rp;
+
+ mutex_lock(&cfset_ctrset_mutex);
+ if (!list_empty(&cfset_session.head)) {
+ list_for_each_entry(rp, &cfset_session.head, node) {
+ p.sets = rp->ctrset;
+ cfset_ioctl_on(&p);
+ cpumask_set_cpu(cpu, &rp->mask);
+ }
+ }
+ mutex_unlock(&cfset_ctrset_mutex);
+ return 0;
+}
+
+/* Hotplug remove of a CPU. Scan through all active processes and clear
+ * that CPU from the list of CPUs supplied with ioctl(..., START, ...).
+ */
+int cfset_offline_cpu(unsigned int cpu)
+{
+ struct cfset_call_on_cpu_parm p;
+ struct cfset_request *rp;
+
+ mutex_lock(&cfset_ctrset_mutex);
+ if (!list_empty(&cfset_session.head)) {
+ list_for_each_entry(rp, &cfset_session.head, node) {
+ p.sets = rp->ctrset;
+ cfset_ioctl_off(&p);
+ cpumask_clear_cpu(cpu, &rp->mask);
+ }
+ }
+ mutex_unlock(&cfset_ctrset_mutex);
+ return 0;
+}
+
+static void cfdiag_read(struct perf_event *event)
+{
+ debug_sprintf_event(cf_dbg, 3, "%s event %#llx count %ld\n", __func__,
+ event->attr.config, local64_read(&event->count));
+}
+
+static int get_authctrsets(void)
+{
+ struct cpu_cf_events *cpuhw;
+ unsigned long auth = 0;
+ enum cpumf_ctr_set i;
+
+ cpuhw = &get_cpu_var(cpu_cf_events);
+ for (i = CPUMF_CTR_SET_BASIC; i < CPUMF_CTR_SET_MAX; ++i) {
+ if (cpuhw->info.auth_ctl & cpumf_ctr_ctl[i])
+ auth |= cpumf_ctr_ctl[i];
+ }
+ put_cpu_var(cpu_cf_events);
+ return auth;
+}
+
+/* Setup the event. Test for authorized counter sets and only include counter
+ * sets which are authorized at the time of the setup. Including unauthorized
+ * counter sets result in specification exception (and panic).
+ */
+static int cfdiag_event_init2(struct perf_event *event)
+{
+ struct perf_event_attr *attr = &event->attr;
+ int err = 0;
+
+ /* Set sample_period to indicate sampling */
+ event->hw.config = attr->config;
+ event->hw.sample_period = attr->sample_period;
+ local64_set(&event->hw.period_left, event->hw.sample_period);
+ local64_set(&event->count, 0);
+ event->hw.last_period = event->hw.sample_period;
+
+ /* Add all authorized counter sets to config_base. The
+ * the hardware init function is either called per-cpu or just once
+ * for all CPUS (event->cpu == -1). This depends on the whether
+ * counting is started for all CPUs or on a per workload base where
+ * the perf event moves from one CPU to another CPU.
+ * Checking the authorization on any CPU is fine as the hardware
+ * applies the same authorization settings to all CPUs.
+ */
+ event->hw.config_base = get_authctrsets();
+
+ /* No authorized counter sets, nothing to count/sample */
+ if (!event->hw.config_base)
+ err = -EINVAL;
+
+ debug_sprintf_event(cf_dbg, 5, "%s err %d config_base %#lx\n",
+ __func__, err, event->hw.config_base);
+ return err;
+}
+
+static int cfdiag_event_init(struct perf_event *event)
+{
+ struct perf_event_attr *attr = &event->attr;
+ int err = -ENOENT;
+
+ if (event->attr.config != PERF_EVENT_CPUM_CF_DIAG ||
+ event->attr.type != event->pmu->type)
+ goto out;
+
+ /* Raw events are used to access counters directly,
+ * hence do not permit excludes.
+ * This event is useless without PERF_SAMPLE_RAW to return counter set
+ * values as raw data.
+ */
+ if (attr->exclude_kernel || attr->exclude_user || attr->exclude_hv ||
+ !(attr->sample_type & (PERF_SAMPLE_CPU | PERF_SAMPLE_RAW))) {
+ err = -EOPNOTSUPP;
+ goto out;
+ }
+
+ /* Initialize for using the CPU-measurement counter facility */
+ cpumf_hw_inuse();
+ event->destroy = hw_perf_event_destroy;
+
+ err = cfdiag_event_init2(event);
+ if (unlikely(err))
+ event->destroy(event);
+out:
+ return err;
+}
+
+/* Create cf_diag/events/CF_DIAG event sysfs file. This counter is used
+ * to collect the complete counter sets for a scheduled process. Target
+ * are complete counter sets attached as raw data to the artificial event.
+ * This results in complete counter sets available when a process is
+ * scheduled. Contains the delta of every counter while the process was
+ * running.
+ */
+CPUMF_EVENT_ATTR(CF_DIAG, CF_DIAG, PERF_EVENT_CPUM_CF_DIAG);
+
+static struct attribute *cfdiag_events_attr[] = {
+ CPUMF_EVENT_PTR(CF_DIAG, CF_DIAG),
+ NULL,
+};
+
+PMU_FORMAT_ATTR(event, "config:0-63");
+
+static struct attribute *cfdiag_format_attr[] = {
+ &format_attr_event.attr,
+ NULL,
+};
+
+static struct attribute_group cfdiag_events_group = {
+ .name = "events",
+ .attrs = cfdiag_events_attr,
+};
+static struct attribute_group cfdiag_format_group = {
+ .name = "format",
+ .attrs = cfdiag_format_attr,
+};
+static const struct attribute_group *cfdiag_attr_groups[] = {
+ &cfdiag_events_group,
+ &cfdiag_format_group,
+ NULL,
+};
+
+/* Performance monitoring unit for event CF_DIAG. Since this event
+ * is also started and stopped via the perf_event_open() system call, use
+ * the same event enable/disable call back functions. They do not
+ * have a pointer to the perf_event strcture as first parameter.
+ *
+ * The functions XXX_add, XXX_del, XXX_start and XXX_stop are also common.
+ * Reuse them and distinguish the event (always first parameter) via
+ * 'config' member.
+ */
+static struct pmu cf_diag = {
+ .task_ctx_nr = perf_sw_context,
+ .event_init = cfdiag_event_init,
+ .pmu_enable = cpumf_pmu_enable,
+ .pmu_disable = cpumf_pmu_disable,
+ .add = cpumf_pmu_add,
+ .del = cpumf_pmu_del,
+ .start = cpumf_pmu_start,
+ .stop = cpumf_pmu_stop,
+ .read = cfdiag_read,
+
+ .attr_groups = cfdiag_attr_groups
+};
+
+/* Calculate memory needed to store all counter sets together with header and
+ * trailer data. This is independent of the counter set authorization which
+ * can vary depending on the configuration.
+ */
+static size_t cfdiag_maxsize(struct cpumf_ctr_info *info)
+{
+ size_t max_size = sizeof(struct cf_trailer_entry);
+ enum cpumf_ctr_set i;
+
+ for (i = CPUMF_CTR_SET_BASIC; i < CPUMF_CTR_SET_MAX; ++i) {
+ size_t size = cpum_cf_ctrset_size(i, info);
+
+ if (size)
+ max_size += size * sizeof(u64) +
+ sizeof(struct cf_ctrset_entry);
+ }
+ return max_size;
+}
+
+/* Get the CPU speed, try sampling facility first and CPU attributes second. */
+static void cfdiag_get_cpu_speed(void)
+{
+ unsigned long mhz;
+
+ if (cpum_sf_avail()) { /* Sampling facility first */
+ struct hws_qsi_info_block si;
+
+ memset(&si, 0, sizeof(si));
+ if (!qsi(&si)) {
+ cfdiag_cpu_speed = si.cpu_speed;
+ return;
+ }
+ }
+
+ /* Fallback: CPU speed extract static part. Used in case
+ * CPU Measurement Sampling Facility is turned off.
+ */
+ mhz = __ecag(ECAG_CPU_ATTRIBUTE, 0);
+ if (mhz != -1UL)
+ cfdiag_cpu_speed = mhz & 0xffffffff;
+}
+
+static int cfset_init(void)
+{
+ struct cpumf_ctr_info info;
+ size_t need;
+ int rc;
+
+ if (qctri(&info))
+ return -ENODEV;
+
+ cfdiag_get_cpu_speed();
+ /* Make sure the counter set data fits into predefined buffer. */
+ need = cfdiag_maxsize(&info);
+ if (need > sizeof(((struct cpu_cf_events *)0)->start)) {
+ pr_err("Insufficient memory for PMU(cpum_cf_diag) need=%zu\n",
+ need);
+ return -ENOMEM;
+ }
+
+ rc = misc_register(&cfset_dev);
+ if (rc) {
+ pr_err("Registration of /dev/%s failed rc=%i\n",
+ cfset_dev.name, rc);
+ goto out;
+ }
+
+ rc = perf_pmu_register(&cf_diag, "cpum_cf_diag", -1);
+ if (rc) {
+ misc_deregister(&cfset_dev);
+ pr_err("Registration of PMU(cpum_cf_diag) failed with rc=%i\n",
+ rc);
+ }
+out:
+ return rc;
+}
+
+device_initcall(cpumf_pmu_init);