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linux-sg2042/arch/s390/kernel/perf_cpum_cf.c

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// SPDX-License-Identifier: GPL-2.0
/*
* Performance event support for s390x - CPU-measurement Counter Facility
*
* Copyright IBM Corp. 2012, 2021
* 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;
}
/* 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 __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;
/* 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;
} else { /* Count user and kernel space */
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;
}
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, PERF_TYPE_RAW);
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;
}
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
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); /* Excl. access */
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_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 */
} cfset_request;
static void cfset_ctrset_clear(void)
{
cpumask_clear(&cfset_request.mask);
cfset_request.ctrset = 0;
}
/* 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;
cpuhw->dev_state = 0;
for (rc = CPUMF_CTR_SET_BASIC; rc < CPUMF_CTR_SET_MAX; ++rc)
if ((p->sets & cpumf_ctr_ctl[rc]))
atomic_dec(&cpuhw->ctr_set[rc]);
rc = lcctl(cpuhw->state); /* Keep perf_event_open counter sets */
if (rc)
pr_err("Counter set stop %#llx of /dev/%s failed rc=%i\n",
cpuhw->state, S390_HWCTR_DEVICE, rc);
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);
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);
cpuhw->dev_state = 0;
}
/* 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)
{
on_each_cpu(cfset_release_cpu, NULL, 1);
hw_perf_event_destroy(NULL);
cfset_ctrset_clear();
atomic_set(&cfset_opencnt, 0);
return 0;
}
static int cfset_open(struct inode *inode, struct file *file)
{
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
/* Only one user space program can open /dev/hwctr */
if (atomic_xchg(&cfset_opencnt, 1))
return -EBUSY;
cpumf_hw_inuse();
file->private_data = NULL;
/* nonseekable_open() never fails */
return nonseekable_open(inode, file);
}
static int cfset_all_stop(void)
{
struct cfset_call_on_cpu_parm p = {
.sets = cfset_request.ctrset,
};
cpumask_var_t mask;
if (!alloc_cpumask_var(&mask, GFP_KERNEL))
return -ENOMEM;
cpumask_and(mask, &cfset_request.mask, cpu_online_mask);
on_each_cpu_mask(mask, cfset_ioctl_off, &p, 1);
free_cpumask_var(mask);
return 0;
}
static int cfset_all_start(void)
{
struct cfset_call_on_cpu_parm p = {
.sets = cfset_request.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, &cfset_request.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_call_on_cpu_parm p;
cpumask_var_t mask;
int rc;
if (!alloc_cpumask_var(&mask, GFP_KERNEL))
return -ENOMEM;
p.sets = cfset_request.ctrset;
cpumask_and(mask, &cfset_request.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 s390_ctrset_read read;
int ret = 0;
if (copy_from_user(&read, (char __user *)arg, sizeof(read)))
return -EFAULT;
ret = cfset_all_read(arg);
return ret;
}
static long cfset_ioctl_stop(void)
{
int ret = ENXIO;
if (cfset_request.ctrset) {
ret = cfset_all_stop();
cfset_ctrset_clear();
}
return ret;
}
static long cfset_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 (cfset_request.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(&cfset_request.mask);
len = min_t(u64, start.cpumask_len, cpumask_size());
umask = (void __user *)start.cpumask;
if (copy_from_user(&cfset_request.mask, umask, len))
return -EFAULT;
if (cpumask_empty(&cfset_request.mask))
return -EINVAL;
need = cfset_needspace(start.counter_sets);
if (put_user(need, &ustart->data_bytes))
ret = -EFAULT;
if (ret)
goto out;
cfset_request.ctrset = start.counter_sets;
ret = cfset_all_start();
out:
if (ret)
cfset_ctrset_clear();
debug_sprintf_event(cf_dbg, 4, "%s sets %#lx need %ld ret %d\n",
__func__, cfset_request.ctrset, need, ret);
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, -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;
get_online_cpus();
mutex_lock(&cfset_ctrset_mutex);
switch (cmd) {
case S390_HWCTR_START:
ret = cfset_ioctl_start(arg);
break;
case S390_HWCTR_STOP:
ret = cfset_ioctl_stop();
break;
case S390_HWCTR_READ:
ret = cfset_ioctl_read(arg);
break;
default:
ret = -ENOTTY;
break;
}
mutex_unlock(&cfset_ctrset_mutex);
put_online_cpus();
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,
};
int cfset_online_cpu(unsigned int cpu)
{
struct cfset_call_on_cpu_parm p;
mutex_lock(&cfset_ctrset_mutex);
if (cfset_request.ctrset) {
p.sets = cfset_request.ctrset;
cfset_ioctl_on(&p);
cpumask_set_cpu(cpu, &cfset_request.mask);
}
mutex_unlock(&cfset_ctrset_mutex);
return 0;
}
int cfset_offline_cpu(unsigned int cpu)
{
struct cfset_call_on_cpu_parm p;
mutex_lock(&cfset_ctrset_mutex);
if (cfset_request.ctrset) {
p.sets = cfset_request.ctrset;
cfset_ioctl_off(&p);
cpumask_clear_cpu(cpu, &cfset_request.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)
{
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.
*/
if (test_facility(34)) {
unsigned long 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);
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