-// SPDX-License-Identifier: GPL-2.0
-/*
- * Performance event support for s390x - CPU-measurement Counter Sets
- *
- * Copyright IBM Corp. 2019, 2021
- * Author(s): Hendrik Brueckner <brueckner@linux.ibm.com>
- * Thomas Richer <tmricht@linux.ibm.com>
- */
-#define KMSG_COMPONENT "cpum_cf_diag"
-#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/slab.h>
-#include <linux/processor.h>
-#include <linux/miscdevice.h>
-#include <linux/mutex.h>
-
-#include <asm/ctl_reg.h>
-#include <asm/irq.h>
-#include <asm/cpu_mcf.h>
-#include <asm/timex.h>
-#include <asm/debug.h>
-
-#include <asm/hwctrset.h>
-
-#define CF_DIAG_CTRSET_DEF 0xfeef /* Counter set header mark */
- /* interval in seconds */
-static unsigned int cf_diag_cpu_speed;
-static debug_info_t *cf_diag_dbg;
-
-struct cf_diag_csd { /* Counter set data per CPU */
- size_t used; /* Bytes used in data/start */
- unsigned char start[PAGE_SIZE]; /* Counter set at event start */
- unsigned char data[PAGE_SIZE]; /* Counter set at event delete */
- unsigned int sets; /* # Counter set saved in data */
-};
-static DEFINE_PER_CPU(struct cf_diag_csd, cf_diag_csd);
-
-/* 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 cf_diag_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 = cf_diag_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();
-}
-
-/*
- * Change the CPUMF state to active.
- * Enable and activate the CPU-counter sets according
- * to the per-cpu control state.
- */
-static void cf_diag_enable(struct pmu *pmu)
-{
- struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
- int err;
-
- debug_sprintf_event(cf_diag_dbg, 5,
- "%s pmu %p cpu %d flags %#x state %#llx\n",
- __func__, pmu, smp_processor_id(), cpuhw->flags,
- cpuhw->state);
- if (cpuhw->flags & PMU_F_ENABLED)
- return;
-
- err = lcctl(cpuhw->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 cf_diag_disable(struct pmu *pmu)
-{
- struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
- u64 inactive;
- int err;
-
- debug_sprintf_event(cf_diag_dbg, 5,
- "%s pmu %p cpu %d flags %#x state %#llx\n",
- __func__, pmu, smp_processor_id(), cpuhw->flags,
- cpuhw->state);
- 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=%x\n", err);
- return;
- }
- cpuhw->flags &= ~PMU_F_ENABLED;
-}
-
-/* Number of perf events counting hardware events */
-static atomic_t cf_diag_events = ATOMIC_INIT(0);
-/* Used to avoid races in calling reserve/release_cpumf_hardware */
-static DEFINE_MUTEX(cf_diag_reserve_mutex);
-
-/* Release the PMU if event is the last perf event */
-static void cf_diag_perf_event_destroy(struct perf_event *event)
-{
- debug_sprintf_event(cf_diag_dbg, 5,
- "%s event %p cpu %d cf_diag_events %d\n",
- __func__, event, smp_processor_id(),
- atomic_read(&cf_diag_events));
- if (atomic_dec_return(&cf_diag_events) == 0)
- __kernel_cpumcf_end();
-}
-
-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 __hw_perf_event_init(struct perf_event *event)
-{
- struct perf_event_attr *attr = &event->attr;
- int err = 0;
-
- debug_sprintf_event(cf_diag_dbg, 5, "%s event %p cpu %d\n", __func__,
- event, event->cpu);
-
- event->hw.config = attr->config;
-
- /* 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;
- goto out;
- }
-
- /* Set sample_period to indicate sampling */
- event->hw.sample_period = attr->sample_period;
- local64_set(&event->hw.period_left, event->hw.sample_period);
- event->hw.last_period = event->hw.sample_period;
-out:
- debug_sprintf_event(cf_diag_dbg, 5, "%s err %d config_base %#lx\n",
- __func__, err, event->hw.config_base);
- return err;
-}
-
-/* Return 0 if the CPU-measurement counter facility is currently free
- * and an error otherwise.
- */
-static int cf_diag_perf_event_inuse(void)
-{
- int err = 0;
-
- if (!atomic_inc_not_zero(&cf_diag_events)) {
- mutex_lock(&cf_diag_reserve_mutex);
- if (atomic_read(&cf_diag_events) == 0 &&
- __kernel_cpumcf_begin())
- err = -EBUSY;
- else
- err = atomic_inc_return(&cf_diag_events);
- mutex_unlock(&cf_diag_reserve_mutex);
- }
- return err;
-}
-
-static int cf_diag_event_init(struct perf_event *event)
-{
- struct perf_event_attr *attr = &event->attr;
- int err = -ENOENT;
-
- debug_sprintf_event(cf_diag_dbg, 5,
- "%s event %p cpu %d config %#llx type:%u "
- "sample_type %#llx cf_diag_events %d\n", __func__,
- event, event->cpu, attr->config, event->pmu->type,
- attr->sample_type, atomic_read(&cf_diag_events));
-
- 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 usesless 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 */
- err = cf_diag_perf_event_inuse();
- if (err < 0)
- goto out;
- event->destroy = cf_diag_perf_event_destroy;
-
- err = __hw_perf_event_init(event);
- if (unlikely(err))
- event->destroy(event);
-out:
- debug_sprintf_event(cf_diag_dbg, 5, "%s err %d\n", __func__, err);
- return err;
-}
-
-static void cf_diag_read(struct perf_event *event)
-{
- debug_sprintf_event(cf_diag_dbg, 5, "%s event %p\n", __func__, event);
-}
-
-/* Calculate memory needed to store all counter sets together with header and
- * trailer data. This is independend of the counter set authorization which
- * can vary depending on the configuration.
- */
-static size_t cf_diag_ctrset_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);
- }
- debug_sprintf_event(cf_diag_dbg, 5, "%s max_size %zu\n", __func__,
- max_size);
-
- return max_size;
-}
-
-/* Read a counter set. The counter set number determines which counter set and
- * the CPUM-CF first and second version number determine the number of
- * available counters in this counter set.
- * Each counter set starts with header containing the counter set number and
- * the number of 8 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.
- */
-static size_t cf_diag_getctrset(struct cf_ctrset_entry *ctrdata, int ctrset,
- size_t room)
-{
- 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)
- ctrdata->ctr = ctrset_size;
- else
- need = 0;
- }
-
- debug_sprintf_event(cf_diag_dbg, 6,
- "%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;
-}
-
-/* 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 cf_diag_getctr(void *data, size_t sz, unsigned long auth)
-{
- 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 = cf_diag_getctrset(ctrdata, i, sz - offset);
- offset += done;
- debug_sprintf_event(cf_diag_dbg, 6,
- "%s ctrset %d offset %zu done %zu\n",
- __func__, i, offset, done);
- }
- trailer = data + offset;
- cf_diag_trailer(trailer);
- return offset + sizeof(*trailer);
-}
-
-/* Calculate the difference for each counter in a counter set. */
-static void cf_diag_diffctrset(u64 *pstart, u64 *pstop, int counters)
-{
- for (; --counters >= 0; ++pstart, ++pstop)
- if (*pstop >= *pstart)
- *pstop -= *pstart;
- else
- *pstop = *pstart - *pstop;
-}
-
-/* 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 cf_diag_diffctr(struct cf_diag_csd *csd, 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 *)(csd->start + offset);
- ctrstop = (struct cf_ctrset_entry *)(csd->data + offset);
-
- if (memcmp(ctrstop, ctrstart, sizeof(*ctrstop))) {
- pr_err("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) {
- cf_diag_diffctrset((u64 *)(ctrstart + 1),
- (u64 *)(ctrstop + 1), ctrstart->ctr);
- offset += ctrstart->ctr * sizeof(u64) +
- sizeof(*ctrstart);
- }
- debug_sprintf_event(cf_diag_dbg, 6,
- "%s set %d ctr %d offset %zu auth %lx\n",
- __func__, ctrstart->set, ctrstart->ctr,
- offset, auth);
- } while (ctrstart->def && auth);
-
- /* Save time_stamp from start of event in stop's trailer */
- trailer_start = (struct cf_trailer_entry *)(csd->start + offset);
- trailer_stop = (struct cf_trailer_entry *)(csd->data + offset);
- trailer_stop->progusage[0] = trailer_start->timestamp;
-
- return 1;
-}
-
-/* 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 cf_diag_push_sample(struct perf_event *event,
- struct cf_diag_csd *csd)
-{
- 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(®s, 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 = csd->used;
- raw.frag.data = csd->data;
- raw.size = csd->used;
- data.raw = &raw;
- }
-
- overflow = perf_event_overflow(event, &data, ®s);
- debug_sprintf_event(cf_diag_dbg, 6,
- "%s event %p cpu %d sample_type %#llx raw %d "
- "ov %d\n", __func__, event, event->cpu,
- event->attr.sample_type, raw.size, overflow);
- if (overflow)
- event->pmu->stop(event, 0);
-
- perf_event_update_userpage(event);
- return overflow;
-}
-
-static void cf_diag_start(struct perf_event *event, int flags)
-{
- struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
- struct cf_diag_csd *csd = this_cpu_ptr(&cf_diag_csd);
- struct hw_perf_event *hwc = &event->hw;
-
- debug_sprintf_event(cf_diag_dbg, 5,
- "%s event %p cpu %d flags %#x hwc-state %#x\n",
- __func__, event, event->cpu, flags, hwc->state);
- if (WARN_ON_ONCE(!(hwc->state & PERF_HES_STOPPED)))
- return;
-
- /* (Re-)enable and activate all counter sets */
- lcctl(0); /* Reset counter sets */
- hwc->state = 0;
- ctr_set_multiple_enable(&cpuhw->state, hwc->config_base);
- lcctl(cpuhw->state); /* Enable counter sets */
- csd->used = cf_diag_getctr(csd->start, sizeof(csd->start),
- event->hw.config_base);
- ctr_set_multiple_start(&cpuhw->state, hwc->config_base);
- /* Function cf_diag_enable() starts the counter sets. */
-}
-
-static void cf_diag_stop(struct perf_event *event, int flags)
-{
- struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
- struct cf_diag_csd *csd = this_cpu_ptr(&cf_diag_csd);
- struct hw_perf_event *hwc = &event->hw;
-
- debug_sprintf_event(cf_diag_dbg, 5,
- "%s event %p cpu %d flags %#x hwc-state %#x\n",
- __func__, event, event->cpu, flags, hwc->state);
-
- /* Deactivate all counter sets */
- ctr_set_multiple_stop(&cpuhw->state, hwc->config_base);
- local64_inc(&event->count);
- csd->used = cf_diag_getctr(csd->data, sizeof(csd->data),
- event->hw.config_base);
- if (cf_diag_diffctr(csd, event->hw.config_base))
- cf_diag_push_sample(event, csd);
- hwc->state |= PERF_HES_STOPPED;
-}
-
-static int cf_diag_add(struct perf_event *event, int flags)
-{
- struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
- int err = 0;
-
- debug_sprintf_event(cf_diag_dbg, 5,
- "%s event %p cpu %d flags %#x cpuhw %p\n",
- __func__, event, event->cpu, flags, cpuhw);
-
- if (cpuhw->flags & PMU_F_IN_USE) {
- err = -EAGAIN;
- goto out;
- }
-
- event->hw.state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
-
- cpuhw->flags |= PMU_F_IN_USE;
- if (flags & PERF_EF_START)
- cf_diag_start(event, PERF_EF_RELOAD);
-out:
- debug_sprintf_event(cf_diag_dbg, 5, "%s err %d\n", __func__, err);
- return err;
-}
-
-static void cf_diag_del(struct perf_event *event, int flags)
-{
- struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
-
- debug_sprintf_event(cf_diag_dbg, 5,
- "%s event %p cpu %d flags %#x\n",
- __func__, event, event->cpu, flags);
-
- cf_diag_stop(event, PERF_EF_UPDATE);
- ctr_set_multiple_stop(&cpuhw->state, event->hw.config_base);
- ctr_set_multiple_disable(&cpuhw->state, event->hw.config_base);
- cpuhw->flags &= ~PMU_F_IN_USE;
-}
-
-/* Default counter set events and format attribute groups */
-
-CPUMF_EVENT_ATTR(CF_DIAG, CF_DIAG, PERF_EVENT_CPUM_CF_DIAG);
-
-static struct attribute *cf_diag_events_attr[] = {
- CPUMF_EVENT_PTR(CF_DIAG, CF_DIAG),
- NULL,
-};
-
-PMU_FORMAT_ATTR(event, "config:0-63");
-
-static struct attribute *cf_diag_format_attr[] = {
- &format_attr_event.attr,
- NULL,
-};
-
-static struct attribute_group cf_diag_events_group = {
- .name = "events",
- .attrs = cf_diag_events_attr,
-};
-static struct attribute_group cf_diag_format_group = {
- .name = "format",
- .attrs = cf_diag_format_attr,
-};
-static const struct attribute_group *cf_diag_attr_groups[] = {
- &cf_diag_events_group,
- &cf_diag_format_group,
- NULL,
-};
-
-/* Performance monitoring unit for s390x */
-static struct pmu cf_diag = {
- .task_ctx_nr = perf_sw_context,
- .pmu_enable = cf_diag_enable,
- .pmu_disable = cf_diag_disable,
- .event_init = cf_diag_event_init,
- .add = cf_diag_add,
- .del = cf_diag_del,
- .start = cf_diag_start,
- .stop = cf_diag_stop,
- .read = cf_diag_read,
-
- .attr_groups = cf_diag_attr_groups
-};
-
-/* Get the CPU speed, try sampling facility first and CPU attributes second. */
-static void cf_diag_get_cpu_speed(void)
-{
- if (cpum_sf_avail()) { /* Sampling facility first */
- struct hws_qsi_info_block si;
-
- memset(&si, 0, sizeof(si));
- if (!qsi(&si)) {
- cf_diag_cpu_speed = si.cpu_speed;
- return;
- }
- }
-
- if (test_facility(34)) { /* CPU speed extract static part */
- unsigned long mhz = __ecag(ECAG_CPU_ATTRIBUTE, 0);
-
- if (mhz != -1UL)
- cf_diag_cpu_speed = mhz & 0xffffffff;
- }
-}
-
-/* Code to create device and file I/O operations */
-static atomic_t ctrset_opencnt = ATOMIC_INIT(0); /* Excl. access */
-
-static int cf_diag_open(struct inode *inode, struct file *file)
-{
- int err = 0;
-
- if (!capable(CAP_SYS_ADMIN))
- return -EPERM;
- if (atomic_xchg(&ctrset_opencnt, 1))
- return -EBUSY;
-
- /* Avoid concurrent access with perf_event_open() system call */
- mutex_lock(&cf_diag_reserve_mutex);
- if (atomic_read(&cf_diag_events) || __kernel_cpumcf_begin())
- err = -EBUSY;
- mutex_unlock(&cf_diag_reserve_mutex);
- if (err) {
- atomic_set(&ctrset_opencnt, 0);
- return err;
- }
- file->private_data = NULL;
- debug_sprintf_event(cf_diag_dbg, 2, "%s\n", __func__);
- /* nonseekable_open() never fails */
- return nonseekable_open(inode, file);
-}
-
-/* Variables for ioctl() interface support */
-static DEFINE_MUTEX(cf_diag_ctrset_mutex);
-static struct cf_diag_ctrset {
- unsigned long ctrset; /* Bit mask of counter set to read */
- cpumask_t mask; /* CPU mask to read from */
-} cf_diag_ctrset;
-
-static void cf_diag_ctrset_clear(void)
-{
- cpumask_clear(&cf_diag_ctrset.mask);
- cf_diag_ctrset.ctrset = 0;
-}
-
-static void cf_diag_release_cpu(void *p)
-{
- struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
-
- debug_sprintf_event(cf_diag_dbg, 3, "%s cpu %d\n", __func__,
- smp_processor_id());
- lcctl(0); /* Reset counter sets */
- cpuhw->state = 0; /* Save state in CPU hardware state */
-}
-
-/* Release function is also called when application gets terminated without
- * doing a proper ioctl(..., S390_HWCTR_STOP, ...) command.
- * Since only one application is allowed to open the device, simple stop all
- * CPU counter sets.
- */
-static int cf_diag_release(struct inode *inode, struct file *file)
-{
- on_each_cpu(cf_diag_release_cpu, NULL, 1);
- cf_diag_ctrset_clear();
- atomic_set(&ctrset_opencnt, 0);
- __kernel_cpumcf_end();
- debug_sprintf_event(cf_diag_dbg, 2, "%s\n", __func__);
- return 0;
-}
-
-struct cf_diag_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 int cf_diag_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 cf_diag_csd *csd = per_cpu_ptr(&cf_diag_csd, cpu);
- struct s390_ctrset_cpudata __user *ctrset_cpudata;
-
- ctrset_cpudata = uptr;
- debug_sprintf_event(cf_diag_dbg, 5, "%s cpu %d used %zd\n",
- __func__, cpu, csd->used);
- rc = put_user(cpu, &ctrset_cpudata->cpu_nr);
- rc |= put_user(csd->sets, &ctrset_cpudata->no_sets);
- rc |= copy_to_user(ctrset_cpudata->data, csd->data, csd->used);
- if (rc)
- return -EFAULT;
- uptr += sizeof(struct s390_ctrset_cpudata) + csd->used;
- cond_resched();
- }
- cpus = cpumask_weight(mask);
- if (put_user(cpus, &ctrset_read->no_cpus))
- return -EFAULT;
- debug_sprintf_event(cf_diag_dbg, 5, "%s copied %ld\n",
- __func__, uptr - (void __user *)ctrset_read->data);
- return 0;
-}
-
-static size_t cf_diag_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;
- debug_sprintf_event(cf_diag_dbg, 5,
- "%s room %zd need %zd set %#x set_size %d\n",
- __func__, room, need, ctrset, 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;
- }
- debug_sprintf_event(cf_diag_dbg, 5, "%s need %zd rc %d\n", __func__,
- need, rc);
- return need;
-}
-
-/* Read all counter sets. Since the perf_event_open() system call with
- * event cpum_cf_diag/.../ is blocked when this interface is active, reuse
- * the perf_event_open() data buffer to store the counter sets.
- */
-static void cf_diag_cpu_read(void *parm)
-{
- struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
- struct cf_diag_csd *csd = this_cpu_ptr(&cf_diag_csd);
- struct cf_diag_call_on_cpu_parm *p = parm;
- int set, set_size;
- size_t space;
-
- debug_sprintf_event(cf_diag_dbg, 5,
- "%s new %#x flags %#x state %#llx\n",
- __func__, p->sets, cpuhw->flags,
- cpuhw->state);
- /* No data saved yet */
- csd->used = 0;
- csd->sets = 0;
- memset(csd->data, 0, sizeof(csd->data));
-
- /* Scan the counter sets */
- for (set = CPUMF_CTR_SET_BASIC; set < CPUMF_CTR_SET_MAX; ++set) {
- struct s390_ctrset_setdata *sp = (void *)csd->data + csd->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(csd->data) - csd->used;
- space = cf_diag_cpuset_read(sp, set, set_size, space);
- if (space) {
- csd->used += space;
- csd->sets += 1;
- }
- debug_sprintf_event(cf_diag_dbg, 5, "%s sp %px space %zd\n",
- __func__, sp, space);
- }
- debug_sprintf_event(cf_diag_dbg, 5, "%s sets %d used %zd\n", __func__,
- csd->sets, csd->used);
-}
-
-static int cf_diag_all_read(unsigned long arg)
-{
- struct cf_diag_call_on_cpu_parm p;
- cpumask_var_t mask;
- int rc;
-
- debug_sprintf_event(cf_diag_dbg, 5, "%s\n", __func__);
- if (!alloc_cpumask_var(&mask, GFP_KERNEL))
- return -ENOMEM;
-
- p.sets = cf_diag_ctrset.ctrset;
- cpumask_and(mask, &cf_diag_ctrset.mask, cpu_online_mask);
- on_each_cpu_mask(mask, cf_diag_cpu_read, &p, 1);
- rc = cf_diag_all_copy(arg, mask);
- free_cpumask_var(mask);
- debug_sprintf_event(cf_diag_dbg, 5, "%s rc %d\n", __func__, rc);
- return rc;
-}
-
-/* Stop all counter sets via ioctl interface */
-static void cf_diag_ioctl_off(void *parm)
-{
- struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
- struct cf_diag_call_on_cpu_parm *p = parm;
- int rc;
-
- debug_sprintf_event(cf_diag_dbg, 5,
- "%s new %#x flags %#x state %#llx\n",
- __func__, p->sets, cpuhw->flags,
- cpuhw->state);
-
- ctr_set_multiple_disable(&cpuhw->state, p->sets);
- ctr_set_multiple_stop(&cpuhw->state, p->sets);
- rc = lcctl(cpuhw->state); /* Stop counter sets */
- if (!cpuhw->state)
- cpuhw->flags &= ~PMU_F_IN_USE;
- debug_sprintf_event(cf_diag_dbg, 5,
- "%s rc %d flags %#x state %#llx\n", __func__,
- rc, cpuhw->flags, cpuhw->state);
-}
-
-/* Start counter sets on particular CPU */
-static void cf_diag_ioctl_on(void *parm)
-{
- struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
- struct cf_diag_call_on_cpu_parm *p = parm;
- int rc;
-
- debug_sprintf_event(cf_diag_dbg, 5,
- "%s new %#x flags %#x state %#llx\n",
- __func__, p->sets, cpuhw->flags,
- cpuhw->state);
-
- if (!(cpuhw->flags & PMU_F_IN_USE))
- cpuhw->state = 0;
- cpuhw->flags |= PMU_F_IN_USE;
- rc = lcctl(cpuhw->state); /* Reset unused counter sets */
- ctr_set_multiple_enable(&cpuhw->state, p->sets);
- ctr_set_multiple_start(&cpuhw->state, p->sets);
- rc |= lcctl(cpuhw->state); /* Start counter sets */
- if (!rc)
- atomic_inc(&p->cpus_ack);
- debug_sprintf_event(cf_diag_dbg, 5, "%s rc %d state %#llx\n",
- __func__, rc, cpuhw->state);
-}
-
-static int cf_diag_all_stop(void)
-{
- struct cf_diag_call_on_cpu_parm p = {
- .sets = cf_diag_ctrset.ctrset,
- };
- cpumask_var_t mask;
-
- if (!alloc_cpumask_var(&mask, GFP_KERNEL))
- return -ENOMEM;
- cpumask_and(mask, &cf_diag_ctrset.mask, cpu_online_mask);
- on_each_cpu_mask(mask, cf_diag_ioctl_off, &p, 1);
- free_cpumask_var(mask);
- return 0;
-}
-
-static int cf_diag_all_start(void)
-{
- struct cf_diag_call_on_cpu_parm p = {
- .sets = cf_diag_ctrset.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, &cf_diag_ctrset.mask, cpu_online_mask);
- on_each_cpu_mask(mask, cf_diag_ioctl_on, &p, 1);
- if (atomic_read(&p.cpus_ack) != cpumask_weight(mask)) {
- on_each_cpu_mask(mask, cf_diag_ioctl_off, &p, 1);
- rc = -EIO;
- }
- 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 cf_diag_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));
- debug_sprintf_event(cf_diag_dbg, 5, "%s bytes %ld\n", __func__,
- bytes);
- put_cpu_ptr(&cpu_cf_events);
- return bytes;
-}
-
-static long cf_diag_ioctl_read(unsigned long arg)
-{
- struct s390_ctrset_read read;
- int ret = 0;
-
- debug_sprintf_event(cf_diag_dbg, 5, "%s\n", __func__);
- if (copy_from_user(&read, (char __user *)arg, sizeof(read)))
- return -EFAULT;
- ret = cf_diag_all_read(arg);
- debug_sprintf_event(cf_diag_dbg, 5, "%s ret %d\n", __func__, ret);
- return ret;
-}
-
-static long cf_diag_ioctl_stop(void)
-{
- int ret;
-
- debug_sprintf_event(cf_diag_dbg, 5, "%s\n", __func__);
- ret = cf_diag_all_stop();
- cf_diag_ctrset_clear();
- debug_sprintf_event(cf_diag_dbg, 5, "%s ret %d\n", __func__, ret);
- return ret;
-}
-
-static long cf_diag_ioctl_start(unsigned long arg)
-{
- struct s390_ctrset_start __user *ustart;
- struct s390_ctrset_start start;
- void __user *umask;
- unsigned int len;
- int ret = 0;
- size_t need;
-
- if (cf_diag_ctrset.ctrset)
- 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? */
- cpumask_clear(&cf_diag_ctrset.mask);
- len = min_t(u64, start.cpumask_len, cpumask_size());
- umask = (void __user *)start.cpumask;
- if (copy_from_user(&cf_diag_ctrset.mask, umask, len))
- return -EFAULT;
- if (cpumask_empty(&cf_diag_ctrset.mask))
- return -EINVAL;
- need = cf_diag_needspace(start.counter_sets);
- if (put_user(need, &ustart->data_bytes))
- ret = -EFAULT;
- if (ret)
- goto out;
- cf_diag_ctrset.ctrset = start.counter_sets;
- ret = cf_diag_all_start();
-out:
- if (ret)
- cf_diag_ctrset_clear();
- debug_sprintf_event(cf_diag_dbg, 2, "%s sets %#lx need %ld ret %d\n",
- __func__, cf_diag_ctrset.ctrset, need, ret);
- return ret;
-}
-
-static long cf_diag_ioctl(struct file *file, unsigned int cmd,
- unsigned long arg)
-{
- int ret;
-
- debug_sprintf_event(cf_diag_dbg, 2, "%s cmd %#x arg %lx\n", __func__,
- cmd, arg);
- get_online_cpus();
- mutex_lock(&cf_diag_ctrset_mutex);
- switch (cmd) {
- case S390_HWCTR_START:
- ret = cf_diag_ioctl_start(arg);
- break;
- case S390_HWCTR_STOP:
- ret = cf_diag_ioctl_stop();
- break;
- case S390_HWCTR_READ:
- ret = cf_diag_ioctl_read(arg);
- break;
- default:
- ret = -ENOTTY;
- break;
- }
- mutex_unlock(&cf_diag_ctrset_mutex);
- put_online_cpus();
- debug_sprintf_event(cf_diag_dbg, 2, "%s ret %d\n", __func__, ret);
- return ret;
-}
-
-static const struct file_operations cf_diag_fops = {
- .owner = THIS_MODULE,
- .open = cf_diag_open,
- .release = cf_diag_release,
- .unlocked_ioctl = cf_diag_ioctl,
- .compat_ioctl = cf_diag_ioctl,
- .llseek = no_llseek
-};
-
-static struct miscdevice cf_diag_dev = {
- .name = S390_HWCTR_DEVICE,
- .minor = MISC_DYNAMIC_MINOR,
- .fops = &cf_diag_fops,
-};
-
-static int cf_diag_online_cpu(unsigned int cpu)
-{
- struct cf_diag_call_on_cpu_parm p;
-
- mutex_lock(&cf_diag_ctrset_mutex);
- if (!cf_diag_ctrset.ctrset)
- goto out;
- p.sets = cf_diag_ctrset.ctrset;
- cf_diag_ioctl_on(&p);
-out:
- mutex_unlock(&cf_diag_ctrset_mutex);
- return 0;
-}
-
-static int cf_diag_offline_cpu(unsigned int cpu)
-{
- struct cf_diag_call_on_cpu_parm p;
-
- mutex_lock(&cf_diag_ctrset_mutex);
- if (!cf_diag_ctrset.ctrset)
- goto out;
- p.sets = cf_diag_ctrset.ctrset;
- cf_diag_ioctl_off(&p);
-out:
- mutex_unlock(&cf_diag_ctrset_mutex);
- return 0;
-}
-
-/* Initialize the counter set PMU to generate complete counter set data as
- * event raw data. This relies on the CPU Measurement Counter Facility device
- * already being loaded and initialized.
- */
-static int __init cf_diag_init(void)
-{
- struct cpumf_ctr_info info;
- size_t need;
- int rc;
-
- if (!kernel_cpumcf_avail() || !stccm_avail() || qctri(&info))
- return -ENODEV;
- cf_diag_get_cpu_speed();
-
- /* Make sure the counter set data fits into predefined buffer. */
- need = cf_diag_ctrset_maxsize(&info);
- if (need > sizeof(((struct cf_diag_csd *)0)->start)) {
- pr_err("Insufficient memory for PMU(cpum_cf_diag) need=%zu\n",
- need);
- return -ENOMEM;
- }
-
- rc = misc_register(&cf_diag_dev);
- if (rc) {
- pr_err("Registration of /dev/" S390_HWCTR_DEVICE
- "failed rc=%d\n", rc);
- goto out;
- }
-
- /* Setup s390dbf facility */
- cf_diag_dbg = debug_register(KMSG_COMPONENT, 2, 1, 128);
- if (!cf_diag_dbg) {
- pr_err("Registration of s390dbf(cpum_cf_diag) failed\n");
- rc = -ENOMEM;
- goto out_dbf;
- }
- debug_register_view(cf_diag_dbg, &debug_sprintf_view);
-
- rc = perf_pmu_register(&cf_diag, "cpum_cf_diag", -1);
- if (rc) {
- pr_err("Registration of PMU(cpum_cf_diag) failed with rc=%i\n",
- rc);
- goto out_perf;
- }
- rc = cpuhp_setup_state_nocalls(CPUHP_AP_PERF_S390_CFD_ONLINE,
- "perf/s390/cfd:online",
- cf_diag_online_cpu, cf_diag_offline_cpu);
- if (!rc)
- goto out;
-
- pr_err("Registration of CPUHP_AP_PERF_S390_CFD_ONLINE failed rc=%i\n",
- rc);
- perf_pmu_unregister(&cf_diag);
-out_perf:
- debug_unregister_view(cf_diag_dbg, &debug_sprintf_view);
- debug_unregister(cf_diag_dbg);
-out_dbf:
- misc_deregister(&cf_diag_dev);
-out:
- return rc;
-}
-device_initcall(cf_diag_init);