#include <linux/percpu.h>
#include <linux/notifier.h>
#include <linux/export.h>
+#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/moduleparam.h>
#include <asm/cpu_mf.h>
#define CPUM_SF_MIN_SDBT 1
/* Number of sample-data-blocks per sample-data-block-table (SDBT):
- * The table contains SDB origin (8 bytes) and one SDBT origin that
- * points to the next table.
+ * A table contains SDB pointers (8 bytes) and one table-link entry
+ * that points to the origin of the next SDBT.
*/
#define CPUM_SF_SDB_PER_TABLE ((PAGE_SIZE - 8) / 8)
/* Minimum and maximum sampling buffer sizes:
*
- * This number represents the maximum size of the sampling buffer
- * taking the number of sample-data-block-tables into account.
+ * This number represents the maximum size of the sampling buffer taking
+ * the number of sample-data-block-tables into account. Note that these
+ * numbers apply to the basic-sampling function only.
+ * The maximum number of SDBs is increased by CPUM_SF_SDB_DIAG_FACTOR if
+ * the diagnostic-sampling function is active.
*
* Sampling buffer size Buffer characteristics
* ---------------------------------------------------
*/
static unsigned long __read_mostly CPUM_SF_MIN_SDB = 15;
static unsigned long __read_mostly CPUM_SF_MAX_SDB = 8176;
+static unsigned long __read_mostly CPUM_SF_SDB_DIAG_FACTOR = 1;
struct sf_buffer {
unsigned long *sdbt; /* Sample-data-block-table origin */
static void sfb_set_limits(unsigned long min, unsigned long max)
{
+ struct hws_qsi_info_block si;
+
CPUM_SF_MIN_SDB = min;
CPUM_SF_MAX_SDB = max;
+
+ memset(&si, 0, sizeof(si));
+ if (!qsi(&si))
+ CPUM_SF_SDB_DIAG_FACTOR = DIV_ROUND_UP(si.dsdes, si.bsdes);
+}
+
+static unsigned long sfb_max_limit(struct hw_perf_event *hwc)
+{
+ return SAMPL_DIAG_MODE(hwc) ? CPUM_SF_MAX_SDB * CPUM_SF_SDB_DIAG_FACTOR
+ : CPUM_SF_MAX_SDB;
}
static unsigned long sfb_pending_allocs(struct sf_buffer *sfb,
static void sfb_account_allocs(unsigned long num, struct hw_perf_event *hwc)
{
- /* Limit the number SDBs to not exceed the maximum */
- num = min_t(unsigned long, num, CPUM_SF_MAX_SDB - SFB_ALLOC_REG(hwc));
+ /* Limit the number of SDBs to not exceed the maximum */
+ num = min_t(unsigned long, num, sfb_max_limit(hwc) - SFB_ALLOC_REG(hwc));
if (num)
SFB_ALLOC_REG(hwc) += num;
}
sfb_account_allocs(num, hwc);
}
-static int allocate_sdbt(struct cpu_hw_sf *cpuhw, struct hw_perf_event *hwc)
+static size_t event_sample_size(struct hw_perf_event *hwc)
+{
+ struct sf_raw_sample *sfr = (struct sf_raw_sample *) RAWSAMPLE_REG(hwc);
+ size_t sample_size;
+
+ /* The sample size depends on the sampling function: The basic-sampling
+ * function must be always enabled, diagnostic-sampling function is
+ * optional.
+ */
+ sample_size = sfr->bsdes;
+ if (SAMPL_DIAG_MODE(hwc))
+ sample_size += sfr->dsdes;
+
+ return sample_size;
+}
+
+static void deallocate_buffers(struct cpu_hw_sf *cpuhw)
+{
+ if (cpuhw->sfb.sdbt)
+ free_sampling_buffer(&cpuhw->sfb);
+}
+
+static int allocate_buffers(struct cpu_hw_sf *cpuhw, struct hw_perf_event *hwc)
{
- unsigned long n_sdb, freq;
- unsigned long factor;
+ unsigned long n_sdb, freq, factor;
+ size_t sfr_size, sample_size;
+ struct sf_raw_sample *sfr;
+
+ /* Allocate raw sample buffer
+ *
+ * The raw sample buffer is used to temporarily store sampling data
+ * entries for perf raw sample processing. The buffer size mainly
+ * depends on the size of diagnostic-sampling data entries which is
+ * machine-specific. The exact size calculation includes:
+ * 1. The first 4 bytes of diagnostic-sampling data entries are
+ * already reflected in the sf_raw_sample structure. Subtract
+ * these bytes.
+ * 2. The perf raw sample data must be 8-byte aligned (u64) and
+ * perf's internal data size must be considered too. So add
+ * an additional u32 for correct alignment and subtract before
+ * allocating the buffer.
+ * 3. Store the raw sample buffer pointer in the perf event
+ * hardware structure.
+ */
+ sfr_size = ALIGN((sizeof(*sfr) - sizeof(sfr->diag) + cpuhw->qsi.dsdes) +
+ sizeof(u32), sizeof(u64));
+ sfr_size -= sizeof(u32);
+ sfr = kzalloc(sfr_size, GFP_KERNEL);
+ if (!sfr)
+ return -ENOMEM;
+ sfr->size = sfr_size;
+ sfr->bsdes = cpuhw->qsi.bsdes;
+ sfr->dsdes = cpuhw->qsi.dsdes;
+ RAWSAMPLE_REG(hwc) = (unsigned long) sfr;
/* Calculate sampling buffers using 4K pages
*
- * 1. Use frequency as input. The samping buffer is designed for
- * a complete second. This can be adjusted through the "factor"
- * variable.
+ * 1. Determine the sample data size which depends on the used
+ * sampling functions, for example, basic-sampling or
+ * basic-sampling with diagnostic-sampling.
+ *
+ * 2. Use the sampling frequency as input. The sampling buffer is
+ * designed for almost one second. This can be adjusted through
+ * the "factor" variable.
* In any case, alloc_sampling_buffer() sets the Alert Request
- * Control indicator to trigger measurement-alert to harvest
+ * Control indicator to trigger a measurement-alert to harvest
* sample-data-blocks (sdb).
*
- * 2. Compute the number of sample-data-blocks and ensure a minimum
+ * 3. Compute the number of sample-data-blocks and ensure a minimum
* of CPUM_SF_MIN_SDB. Also ensure the upper limit does not
- * exceed CPUM_SF_MAX_SDB. See also the remarks for these
- * symbolic constants.
+ * exceed a "calculated" maximum. The symbolic maximum is
+ * designed for basic-sampling only and needs to be increased if
+ * diagnostic-sampling is active.
+ * See also the remarks for these symbolic constants.
*
- * 3. Compute number of pages used for the sample-data-block-table
- * and ensure a minimum of CPUM_SF_MIN_SDBT (at minimum one table
- * to manage up to 511 sample-data-blocks).
+ * 4. Compute the number of sample-data-block-tables (SDBT) and
+ * ensure a minimum of CPUM_SF_MIN_SDBT (one table can manage up
+ * to 511 SDBs).
*/
+ sample_size = event_sample_size(hwc);
freq = sample_rate_to_freq(&cpuhw->qsi, SAMPL_RATE(hwc));
factor = 1;
- n_sdb = DIV_ROUND_UP(freq, factor * ((PAGE_SIZE-64) / cpuhw->qsi.bsdes));
+ n_sdb = DIV_ROUND_UP(freq, factor * ((PAGE_SIZE-64) / sample_size));
if (n_sdb < CPUM_SF_MIN_SDB)
n_sdb = CPUM_SF_MIN_SDB;
return 0;
debug_sprintf_event(sfdbg, 3,
- "allocate_sdbt: rate=%lu f=%lu sdb=%lu/%lu cpuhw=%p\n",
- SAMPL_RATE(hwc), freq, n_sdb, CPUM_SF_MAX_SDB, cpuhw);
+ "allocate_buffers: rate=%lu f=%lu sdb=%lu/%lu"
+ " sample_size=%lu cpuhw=%p\n",
+ SAMPL_RATE(hwc), freq, n_sdb, sfb_max_limit(hwc),
+ sample_size, cpuhw);
return alloc_sampling_buffer(&cpuhw->sfb,
sfb_pending_allocs(&cpuhw->sfb, hwc));
if (err) {
pr_err("Switching off the sampling facility failed "
"with rc=%i\n", err);
- } else {
- if (cpusf->sfb.sdbt)
- free_sampling_buffer(&cpusf->sfb);
- }
+ } else
+ deallocate_buffers(cpusf);
debug_sprintf_event(sfdbg, 5,
"setup_pmc_cpu: released: cpuhw=%p\n", cpusf);
break;
static void hw_perf_event_destroy(struct perf_event *event)
{
+ /* Free raw sample buffer */
+ if (RAWSAMPLE_REG(&event->hw))
+ kfree((void *) RAWSAMPLE_REG(&event->hw));
+
/* Release PMC if this is the last perf event */
if (!atomic_add_unless(&num_events, -1, 1)) {
mutex_lock(&pmc_reserve_mutex);
static void hw_reset_registers(struct hw_perf_event *hwc,
unsigned long *sdbt_origin)
{
+ struct sf_raw_sample *sfr;
+
/* (Re)set to first sample-data-block-table */
TEAR_REG(hwc) = (unsigned long) sdbt_origin;
+
+ /* (Re)set raw sampling buffer register */
+ sfr = (struct sf_raw_sample *) RAWSAMPLE_REG(hwc);
+ memset(&sfr->basic, 0, sizeof(sfr->basic));
+ memset(&sfr->diag, 0, sfr->dsdes);
}
static unsigned long hw_limit_rate(const struct hws_qsi_info_block *si,
goto out;
}
+ /* Always enable basic sampling */
+ SAMPL_FLAGS(hwc) = PERF_CPUM_SF_BASIC_MODE;
+
+ /* Check if diagnostic sampling is requested. Deny if the required
+ * sampling authorization is missing.
+ */
+ if (attr->config == PERF_EVENT_CPUM_SF_DIAG) {
+ if (!si.ad) {
+ err = -EPERM;
+ goto out;
+ }
+ SAMPL_FLAGS(hwc) |= PERF_CPUM_SF_DIAG_MODE;
+ }
+
/* The sampling information (si) contains information about the
* min/max sampling intervals and the CPU speed. So calculate the
* correct sampling interval and avoid the whole period adjust
*/
if (cpuhw)
/* Event is pinned to a particular CPU */
- err = allocate_sdbt(cpuhw, hwc);
+ err = allocate_buffers(cpuhw, hwc);
else {
/* Event is not pinned, allocate sampling buffer on
* each online CPU
*/
for_each_online_cpu(cpu) {
cpuhw = &per_cpu(cpu_hw_sf, cpu);
- err = allocate_sdbt(cpuhw, hwc);
+ err = allocate_buffers(cpuhw, hwc);
if (err)
break;
}
switch (event->attr.type) {
case PERF_TYPE_RAW:
- if (event->attr.config != PERF_EVENT_CPUM_SF)
+ if ((event->attr.config != PERF_EVENT_CPUM_SF) &&
+ (event->attr.config != PERF_EVENT_CPUM_SF_DIAG))
return -ENOENT;
break;
case PERF_TYPE_HARDWARE:
return;
}
- debug_sprintf_event(sfdbg, 6, "pmu_enable: es=%i cs=%i tear=%p dear=%p\n",
- cpuhw->lsctl.es, cpuhw->lsctl.cs,
+ debug_sprintf_event(sfdbg, 6, "pmu_enable: es=%i cs=%i ed=%i cd=%i "
+ "tear=%p dear=%p\n", cpuhw->lsctl.es, cpuhw->lsctl.cs,
+ cpuhw->lsctl.ed, cpuhw->lsctl.cd,
(void *) cpuhw->lsctl.tear, (void *) cpuhw->lsctl.dear);
}
/* Switch off sampling activation control */
inactive = cpuhw->lsctl;
inactive.cs = 0;
+ inactive.cd = 0;
err = lsctl(&inactive);
if (err) {
*
* Return non-zero if an event overflow occurred.
*/
-static int perf_push_sample(struct perf_event *event,
- struct hws_data_entry *sample)
+static int perf_push_sample(struct perf_event *event, struct sf_raw_sample *sfr)
{
int overflow;
struct pt_regs regs;
struct perf_sf_sde_regs *sde_regs;
struct perf_sample_data data;
+ struct perf_raw_record raw;
- /* Skip samples that are invalid or for which the instruction address
- * is not predictable. For the latter, the wait-state bit is set.
- */
- if (sample->I || sample->W)
- return 0;
-
+ /* Setup perf sample */
perf_sample_data_init(&data, 0, event->hw.last_period);
+ raw.size = sfr->size;
+ raw.data = sfr;
+ data.raw = &raw;
/* Setup pt_regs to look like an CPU-measurement external interrupt
* using the Program Request Alert code. The regs.int_parm_long
regs.int_parm = CPU_MF_INT_SF_PRA;
sde_regs = (struct perf_sf_sde_regs *) ®s.int_parm_long;
- regs.psw.addr = sample->ia;
- if (sample->T)
+ regs.psw.addr = sfr->basic.ia;
+ if (sfr->basic.T)
regs.psw.mask |= PSW_MASK_DAT;
- if (sample->W)
+ if (sfr->basic.W)
regs.psw.mask |= PSW_MASK_WAIT;
- if (sample->P)
+ if (sfr->basic.P)
regs.psw.mask |= PSW_MASK_PSTATE;
- switch (sample->AS) {
+ switch (sfr->basic.AS) {
case 0x0:
regs.psw.mask |= PSW_ASC_PRIMARY;
break;
* purposes too.
* For now, simply use a non-zero value as guest indicator.
*/
- if (sample->hpp)
+ if (sfr->basic.hpp)
sde_regs->in_guest = 1;
overflow = 0;
local64_add(count, &event->count);
}
+static int sample_format_is_valid(struct hws_combined_entry *sample,
+ unsigned int flags)
+{
+ if (likely(flags & PERF_CPUM_SF_BASIC_MODE))
+ /* Only basic-sampling data entries with data-entry-format
+ * version of 0x0001 can be processed.
+ */
+ if (sample->basic.def != 0x0001)
+ return 0;
+ if (flags & PERF_CPUM_SF_DIAG_MODE)
+ /* The data-entry-format number of diagnostic-sampling data
+ * entries can vary. Because diagnostic data is just passed
+ * through, do only a sanity check on the DEF.
+ */
+ if (sample->diag.def < 0x8001)
+ return 0;
+ return 1;
+}
+
+static int sample_is_consistent(struct hws_combined_entry *sample,
+ unsigned long flags)
+{
+ /* This check applies only to basic-sampling data entries of potentially
+ * combined-sampling data entries. Invalid entries cannot be processed
+ * by the PMU and, thus, do not deliver an associated
+ * diagnostic-sampling data entry.
+ */
+ if (unlikely(!(flags & PERF_CPUM_SF_BASIC_MODE)))
+ return 0;
+ /*
+ * Samples are skipped, if they are invalid or for which the
+ * instruction address is not predictable, i.e., the wait-state bit is
+ * set.
+ */
+ if (sample->basic.I || sample->basic.W)
+ return 0;
+ return 1;
+}
+
+static void reset_sample_slot(struct hws_combined_entry *sample,
+ unsigned long flags)
+{
+ if (likely(flags & PERF_CPUM_SF_BASIC_MODE))
+ sample->basic.def = 0;
+ if (flags & PERF_CPUM_SF_DIAG_MODE)
+ sample->diag.def = 0;
+}
+
+static void sfr_store_sample(struct sf_raw_sample *sfr,
+ struct hws_combined_entry *sample)
+{
+ if (likely(sfr->format & PERF_CPUM_SF_BASIC_MODE))
+ sfr->basic = sample->basic;
+ if (sfr->format & PERF_CPUM_SF_DIAG_MODE)
+ memcpy(&sfr->diag, &sample->diag, sfr->dsdes);
+}
+
+static void debug_sample_entry(struct hws_combined_entry *sample,
+ struct hws_trailer_entry *te,
+ unsigned long flags)
+{
+ debug_sprintf_event(sfdbg, 4, "hw_collect_samples: Found unknown "
+ "sampling data entry: te->f=%i basic.def=%04x (%p)"
+ " diag.def=%04x (%p)\n", te->f,
+ sample->basic.def, &sample->basic,
+ (flags & PERF_CPUM_SF_DIAG_MODE)
+ ? sample->diag.def : 0xFFFF,
+ (flags & PERF_CPUM_SF_DIAG_MODE)
+ ? &sample->diag : NULL);
+}
+
/* hw_collect_samples() - Walk through a sample-data-block and collect samples
* @event: The perf event
* @sdbt: Sample-data-block table
* @overflow: Event overflow counter
*
- * Walks through a sample-data-block and collects hardware sample-data that is
- * pushed to the perf event subsystem. The overflow reports the number of
- * samples that has been discarded due to an event overflow.
+ * Walks through a sample-data-block and collects sampling data entries that are
+ * then pushed to the perf event subsystem. Depending on the sampling function,
+ * there can be either basic-sampling or combined-sampling data entries. A
+ * combined-sampling data entry consists of a basic- and a diagnostic-sampling
+ * data entry. The sampling function is determined by the flags in the perf
+ * event hardware structure. The function always works with a combined-sampling
+ * data entry but ignores the the diagnostic portion if it is not available.
+ *
+ * Note that the implementation focuses on basic-sampling data entries and, if
+ * such an entry is not valid, the entire combined-sampling data entry is
+ * ignored.
+ *
+ * The overflow variables counts the number of samples that has been discarded
+ * due to a perf event overflow.
*/
static void hw_collect_samples(struct perf_event *event, unsigned long *sdbt,
unsigned long long *overflow)
{
- struct hws_data_entry *sample;
- unsigned long *trailer;
+ unsigned long flags = SAMPL_FLAGS(&event->hw);
+ struct hws_combined_entry *sample;
+ struct hws_trailer_entry *te;
+ struct sf_raw_sample *sfr;
+ size_t sample_size;
+
+ /* Prepare and initialize raw sample data */
+ sfr = (struct sf_raw_sample *) RAWSAMPLE_REG(&event->hw);
+ sfr->format = flags & PERF_CPUM_SF_MODE_MASK;
- trailer = trailer_entry_ptr(*sdbt);
- sample = (struct hws_data_entry *) *sdbt;
- while ((unsigned long *) sample < trailer) {
+ sample_size = event_sample_size(&event->hw);
+ te = (struct hws_trailer_entry *) trailer_entry_ptr(*sdbt);
+ sample = (struct hws_combined_entry *) *sdbt;
+ while ((unsigned long *) sample < (unsigned long *) te) {
/* Check for an empty sample */
- if (!sample->def)
+ if (!sample->basic.def)
break;
/* Update perf event period */
perf_event_count_update(event, SAMPL_RATE(&event->hw));
- /* Check for basic sampling mode */
- if (sample->def == 0x0001) {
+ /* Check sampling data entry */
+ if (sample_format_is_valid(sample, flags)) {
/* If an event overflow occurred, the PMU is stopped to
* throttle event delivery. Remaining sample data is
* discarded.
*/
- if (!*overflow)
- *overflow = perf_push_sample(event, sample);
- else
+ if (!*overflow) {
+ if (sample_is_consistent(sample, flags)) {
+ /* Deliver sample data to perf */
+ sfr_store_sample(sfr, sample);
+ *overflow = perf_push_sample(event, sfr);
+ }
+ } else
/* Count discarded samples */
*overflow += 1;
- } else
- /* Sample slot is not yet written or other record */
- debug_sprintf_event(sfdbg, 5, "hw_collect_samples: "
- "Unknown sample data entry format:"
- " %i\n", sample->def);
+ } else {
+ debug_sample_entry(sample, te, flags);
+ /* Sample slot is not yet written or other record.
+ *
+ * This condition can occur if the buffer was reused
+ * from a combined basic- and diagnostic-sampling.
+ * If only basic-sampling is then active, entries are
+ * written into the larger diagnostic entries.
+ * This is typically the case for sample-data-blocks
+ * that are not full. Stop processing if the first
+ * invalid format was detected.
+ */
+ if (!te->f)
+ break;
+ }
/* Reset sample slot and advance to next sample */
- sample->def = 0;
- sample++;
+ reset_sample_slot(sample, flags);
+ sample += sample_size;
}
}
perf_pmu_disable(event->pmu);
event->hw.state = 0;
cpuhw->lsctl.cs = 1;
+ if (SAMPL_DIAG_MODE(&event->hw))
+ cpuhw->lsctl.cd = 1;
perf_pmu_enable(event->pmu);
}
perf_pmu_disable(event->pmu);
cpuhw->lsctl.cs = 0;
+ cpuhw->lsctl.cd = 0;
event->hw.state |= PERF_HES_STOPPED;
if ((flags & PERF_EF_UPDATE) && !(event->hw.state & PERF_HES_UPTODATE)) {
/* Ensure sampling functions are in the disabled state. If disabled,
* switch on sampling enable control. */
- if (WARN_ON_ONCE(cpuhw->lsctl.es == 1)) {
+ if (WARN_ON_ONCE(cpuhw->lsctl.es == 1 || cpuhw->lsctl.ed == 1)) {
err = -EAGAIN;
goto out;
}
cpuhw->lsctl.es = 1;
+ if (SAMPL_DIAG_MODE(&event->hw))
+ cpuhw->lsctl.ed = 1;
/* Set in_use flag and store event */
event->hw.idx = 0; /* only one sampling event per CPU supported */
cpumsf_pmu_stop(event, PERF_EF_UPDATE);
cpuhw->lsctl.es = 0;
+ cpuhw->lsctl.ed = 0;
cpuhw->flags &= ~PMU_F_IN_USE;
cpuhw->event = NULL;
}
CPUMF_EVENT_ATTR(SF, SF_CYCLES_BASIC, PERF_EVENT_CPUM_SF);
+CPUMF_EVENT_ATTR(SF, SF_CYCLES_BASIC_DIAG, PERF_EVENT_CPUM_SF_DIAG);
static struct attribute *cpumsf_pmu_events_attr[] = {
CPUMF_EVENT_PTR(SF, SF_CYCLES_BASIC),
+ CPUMF_EVENT_PTR(SF, SF_CYCLES_BASIC_DIAG),
NULL,
};
return rc;
sfb_set_limits(min, max);
- pr_info("Changed sampling buffer settings: min=%lu max=%lu\n",
- CPUM_SF_MIN_SDB, CPUM_SF_MAX_SDB);
+ pr_info("The sampling buffer limits have changed to: "
+ "min=%lu max=%lu (diag=x%lu)\n",
+ CPUM_SF_MIN_SDB, CPUM_SF_MAX_SDB, CPUM_SF_SDB_DIAG_FACTOR);
return 0;
}
.get = param_get_sfb_size,
};
+#define RS_INIT_FAILURE_QSI 0x0001
+#define RS_INIT_FAILURE_BSDES 0x0002
+#define RS_INIT_FAILURE_ALRT 0x0003
+#define RS_INIT_FAILURE_PERF 0x0004
+static void __init pr_cpumsf_err(unsigned int reason)
+{
+ pr_err("Sampling facility support for perf is not available: "
+ "reason=%04x\n", reason);
+}
+
static int __init init_cpum_sampling_pmu(void)
{
+ struct hws_qsi_info_block si;
int err;
if (!cpum_sf_avail())
return -ENODEV;
+ memset(&si, 0, sizeof(si));
+ if (qsi(&si)) {
+ pr_cpumsf_err(RS_INIT_FAILURE_QSI);
+ return -ENODEV;
+ }
+
+ if (si.bsdes != sizeof(struct hws_basic_entry)) {
+ pr_cpumsf_err(RS_INIT_FAILURE_BSDES);
+ return -EINVAL;
+ }
+
+ if (si.ad)
+ sfb_set_limits(CPUM_SF_MIN_SDB, CPUM_SF_MAX_SDB);
+
sfdbg = debug_register(KMSG_COMPONENT, 2, 1, 80);
if (!sfdbg)
pr_err("Registering for s390dbf failed\n");
err = register_external_interrupt(0x1407, cpumf_measurement_alert);
if (err) {
- pr_err("Failed to register for CPU-measurement alerts\n");
+ pr_cpumsf_err(RS_INIT_FAILURE_ALRT);
goto out;
}
err = perf_pmu_register(&cpumf_sampling, "cpum_sf", PERF_TYPE_RAW);
if (err) {
- pr_err("Failed to register cpum_sf pmu\n");
+ pr_cpumsf_err(RS_INIT_FAILURE_PERF);
unregister_external_interrupt(0x1407, cpumf_measurement_alert);
goto out;
}
projects / platform / kernel / linux-rpi.git / commitdiff