2 * Performance event support for the System z CPU-measurement Sampling Facility
4 * Copyright IBM Corp. 2013
5 * Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License (version 2 only)
9 * as published by the Free Software Foundation.
11 #define KMSG_COMPONENT "cpum_sf"
12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
14 #include <linux/kernel.h>
15 #include <linux/kernel_stat.h>
16 #include <linux/perf_event.h>
17 #include <linux/percpu.h>
18 #include <linux/notifier.h>
19 #include <linux/export.h>
20 #include <linux/slab.h>
22 #include <linux/moduleparam.h>
23 #include <asm/cpu_mf.h>
25 #include <asm/debug.h>
26 #include <asm/timex.h>
28 /* Minimum number of sample-data-block-tables:
29 * At least one table is required for the sampling buffer structure.
30 * A single table contains up to 511 pointers to sample-data-blocks.
32 #define CPUM_SF_MIN_SDBT 1
34 /* Number of sample-data-blocks per sample-data-block-table (SDBT):
35 * A table contains SDB pointers (8 bytes) and one table-link entry
36 * that points to the origin of the next SDBT.
38 #define CPUM_SF_SDB_PER_TABLE ((PAGE_SIZE - 8) / 8)
40 /* Maximum page offset for an SDBT table-link entry:
41 * If this page offset is reached, a table-link entry to the next SDBT
44 #define CPUM_SF_SDBT_TL_OFFSET (CPUM_SF_SDB_PER_TABLE * 8)
45 static inline int require_table_link(const void *sdbt
)
47 return ((unsigned long) sdbt
& ~PAGE_MASK
) == CPUM_SF_SDBT_TL_OFFSET
;
50 /* Minimum and maximum sampling buffer sizes:
52 * This number represents the maximum size of the sampling buffer taking
53 * the number of sample-data-block-tables into account. Note that these
54 * numbers apply to the basic-sampling function only.
55 * The maximum number of SDBs is increased by CPUM_SF_SDB_DIAG_FACTOR if
56 * the diagnostic-sampling function is active.
58 * Sampling buffer size Buffer characteristics
59 * ---------------------------------------------------
60 * 64KB == 16 pages (4KB per page)
61 * 1 page for SDB-tables
64 * 32MB == 8192 pages (4KB per page)
65 * 16 pages for SDB-tables
68 static unsigned long __read_mostly CPUM_SF_MIN_SDB
= 15;
69 static unsigned long __read_mostly CPUM_SF_MAX_SDB
= 8176;
70 static unsigned long __read_mostly CPUM_SF_SDB_DIAG_FACTOR
= 1;
73 unsigned long *sdbt
; /* Sample-data-block-table origin */
74 /* buffer characteristics (required for buffer increments) */
75 unsigned long num_sdb
; /* Number of sample-data-blocks */
76 unsigned long num_sdbt
; /* Number of sample-data-block-tables */
77 unsigned long *tail
; /* last sample-data-block-table */
81 /* CPU-measurement sampling information block */
82 struct hws_qsi_info_block qsi
;
83 /* CPU-measurement sampling control block */
84 struct hws_lsctl_request_block lsctl
;
85 struct sf_buffer sfb
; /* Sampling buffer */
86 unsigned int flags
; /* Status flags */
87 struct perf_event
*event
; /* Scheduled perf event */
89 static DEFINE_PER_CPU(struct cpu_hw_sf
, cpu_hw_sf
);
92 static debug_info_t
*sfdbg
;
95 * sf_disable() - Switch off sampling facility
97 static int sf_disable(void)
99 struct hws_lsctl_request_block sreq
;
101 memset(&sreq
, 0, sizeof(sreq
));
106 * sf_buffer_available() - Check for an allocated sampling buffer
108 static int sf_buffer_available(struct cpu_hw_sf
*cpuhw
)
110 return !!cpuhw
->sfb
.sdbt
;
114 * deallocate sampling facility buffer
116 static void free_sampling_buffer(struct sf_buffer
*sfb
)
118 unsigned long *sdbt
, *curr
;
126 /* Free the SDBT after all SDBs are processed... */
131 /* Process table-link entries */
132 if (is_link_entry(curr
)) {
133 curr
= get_next_sdbt(curr
);
135 free_page((unsigned long) sdbt
);
137 /* If the origin is reached, sampling buffer is freed */
138 if (curr
== sfb
->sdbt
)
143 /* Process SDB pointer */
151 debug_sprintf_event(sfdbg
, 5,
152 "free_sampling_buffer: freed sdbt=%p\n", sfb
->sdbt
);
153 memset(sfb
, 0, sizeof(*sfb
));
156 static int alloc_sample_data_block(unsigned long *sdbt
, gfp_t gfp_flags
)
158 unsigned long sdb
, *trailer
;
160 /* Allocate and initialize sample-data-block */
161 sdb
= get_zeroed_page(gfp_flags
);
164 trailer
= trailer_entry_ptr(sdb
);
165 *trailer
= SDB_TE_ALERT_REQ_MASK
;
167 /* Link SDB into the sample-data-block-table */
174 * realloc_sampling_buffer() - extend sampler memory
176 * Allocates new sample-data-blocks and adds them to the specified sampling
179 * Important: This modifies the sampling buffer and must be called when the
180 * sampling facility is disabled.
182 * Returns zero on success, non-zero otherwise.
184 static int realloc_sampling_buffer(struct sf_buffer
*sfb
,
185 unsigned long num_sdb
, gfp_t gfp_flags
)
188 unsigned long *new, *tail
;
190 if (!sfb
->sdbt
|| !sfb
->tail
)
193 if (!is_link_entry(sfb
->tail
))
196 /* Append to the existing sampling buffer, overwriting the table-link
198 * The tail variables always points to the "tail" (last and table-link)
199 * entry in an SDB-table.
203 /* Do a sanity check whether the table-link entry points to
204 * the sampling buffer origin.
206 if (sfb
->sdbt
!= get_next_sdbt(tail
)) {
207 debug_sprintf_event(sfdbg
, 3, "realloc_sampling_buffer: "
208 "sampling buffer is not linked: origin=%p"
210 (void *) sfb
->sdbt
, (void *) tail
);
214 /* Allocate remaining SDBs */
216 for (i
= 0; i
< num_sdb
; i
++) {
217 /* Allocate a new SDB-table if it is full. */
218 if (require_table_link(tail
)) {
219 new = (unsigned long *) get_zeroed_page(gfp_flags
);
225 /* Link current page to tail of chain */
226 *tail
= (unsigned long)(void *) new + 1;
230 /* Allocate a new sample-data-block.
231 * If there is not enough memory, stop the realloc process
232 * and simply use what was allocated. If this is a temporary
233 * issue, a new realloc call (if required) might succeed.
235 rc
= alloc_sample_data_block(tail
, gfp_flags
);
242 /* Link sampling buffer to its origin */
243 *tail
= (unsigned long) sfb
->sdbt
+ 1;
246 debug_sprintf_event(sfdbg
, 4, "realloc_sampling_buffer: new buffer"
247 " settings: sdbt=%lu sdb=%lu\n",
248 sfb
->num_sdbt
, sfb
->num_sdb
);
253 * allocate_sampling_buffer() - allocate sampler memory
255 * Allocates and initializes a sampling buffer structure using the
256 * specified number of sample-data-blocks (SDB). For each allocation,
257 * a 4K page is used. The number of sample-data-block-tables (SDBT)
258 * are calculated from SDBs.
259 * Also set the ALERT_REQ mask in each SDBs trailer.
261 * Returns zero on success, non-zero otherwise.
263 static int alloc_sampling_buffer(struct sf_buffer
*sfb
, unsigned long num_sdb
)
270 /* Allocate the sample-data-block-table origin */
271 sfb
->sdbt
= (unsigned long *) get_zeroed_page(GFP_KERNEL
);
277 /* Link the table origin to point to itself to prepare for
278 * realloc_sampling_buffer() invocation.
280 sfb
->tail
= sfb
->sdbt
;
281 *sfb
->tail
= (unsigned long)(void *) sfb
->sdbt
+ 1;
283 /* Allocate requested number of sample-data-blocks */
284 rc
= realloc_sampling_buffer(sfb
, num_sdb
, GFP_KERNEL
);
286 free_sampling_buffer(sfb
);
287 debug_sprintf_event(sfdbg
, 4, "alloc_sampling_buffer: "
288 "realloc_sampling_buffer failed with rc=%i\n", rc
);
290 debug_sprintf_event(sfdbg
, 4,
291 "alloc_sampling_buffer: tear=%p dear=%p\n",
292 sfb
->sdbt
, (void *) *sfb
->sdbt
);
296 static void sfb_set_limits(unsigned long min
, unsigned long max
)
298 struct hws_qsi_info_block si
;
300 CPUM_SF_MIN_SDB
= min
;
301 CPUM_SF_MAX_SDB
= max
;
303 memset(&si
, 0, sizeof(si
));
305 CPUM_SF_SDB_DIAG_FACTOR
= DIV_ROUND_UP(si
.dsdes
, si
.bsdes
);
308 static unsigned long sfb_max_limit(struct hw_perf_event
*hwc
)
310 return SAMPL_DIAG_MODE(hwc
) ? CPUM_SF_MAX_SDB
* CPUM_SF_SDB_DIAG_FACTOR
314 static unsigned long sfb_pending_allocs(struct sf_buffer
*sfb
,
315 struct hw_perf_event
*hwc
)
318 return SFB_ALLOC_REG(hwc
);
319 if (SFB_ALLOC_REG(hwc
) > sfb
->num_sdb
)
320 return SFB_ALLOC_REG(hwc
) - sfb
->num_sdb
;
324 static int sfb_has_pending_allocs(struct sf_buffer
*sfb
,
325 struct hw_perf_event
*hwc
)
327 return sfb_pending_allocs(sfb
, hwc
) > 0;
330 static void sfb_account_allocs(unsigned long num
, struct hw_perf_event
*hwc
)
332 /* Limit the number of SDBs to not exceed the maximum */
333 num
= min_t(unsigned long, num
, sfb_max_limit(hwc
) - SFB_ALLOC_REG(hwc
));
335 SFB_ALLOC_REG(hwc
) += num
;
338 static void sfb_init_allocs(unsigned long num
, struct hw_perf_event
*hwc
)
340 SFB_ALLOC_REG(hwc
) = 0;
341 sfb_account_allocs(num
, hwc
);
344 static size_t event_sample_size(struct hw_perf_event
*hwc
)
346 struct sf_raw_sample
*sfr
= (struct sf_raw_sample
*) RAWSAMPLE_REG(hwc
);
349 /* The sample size depends on the sampling function: The basic-sampling
350 * function must be always enabled, diagnostic-sampling function is
353 sample_size
= sfr
->bsdes
;
354 if (SAMPL_DIAG_MODE(hwc
))
355 sample_size
+= sfr
->dsdes
;
360 static void deallocate_buffers(struct cpu_hw_sf
*cpuhw
)
363 free_sampling_buffer(&cpuhw
->sfb
);
366 static int allocate_buffers(struct cpu_hw_sf
*cpuhw
, struct hw_perf_event
*hwc
)
368 unsigned long n_sdb
, freq
, factor
;
369 size_t sfr_size
, sample_size
;
370 struct sf_raw_sample
*sfr
;
372 /* Allocate raw sample buffer
374 * The raw sample buffer is used to temporarily store sampling data
375 * entries for perf raw sample processing. The buffer size mainly
376 * depends on the size of diagnostic-sampling data entries which is
377 * machine-specific. The exact size calculation includes:
378 * 1. The first 4 bytes of diagnostic-sampling data entries are
379 * already reflected in the sf_raw_sample structure. Subtract
381 * 2. The perf raw sample data must be 8-byte aligned (u64) and
382 * perf's internal data size must be considered too. So add
383 * an additional u32 for correct alignment and subtract before
384 * allocating the buffer.
385 * 3. Store the raw sample buffer pointer in the perf event
386 * hardware structure.
388 sfr_size
= ALIGN((sizeof(*sfr
) - sizeof(sfr
->diag
) + cpuhw
->qsi
.dsdes
) +
389 sizeof(u32
), sizeof(u64
));
390 sfr_size
-= sizeof(u32
);
391 sfr
= kzalloc(sfr_size
, GFP_KERNEL
);
394 sfr
->size
= sfr_size
;
395 sfr
->bsdes
= cpuhw
->qsi
.bsdes
;
396 sfr
->dsdes
= cpuhw
->qsi
.dsdes
;
397 RAWSAMPLE_REG(hwc
) = (unsigned long) sfr
;
399 /* Calculate sampling buffers using 4K pages
401 * 1. Determine the sample data size which depends on the used
402 * sampling functions, for example, basic-sampling or
403 * basic-sampling with diagnostic-sampling.
405 * 2. Use the sampling frequency as input. The sampling buffer is
406 * designed for almost one second. This can be adjusted through
407 * the "factor" variable.
408 * In any case, alloc_sampling_buffer() sets the Alert Request
409 * Control indicator to trigger a measurement-alert to harvest
410 * sample-data-blocks (sdb).
412 * 3. Compute the number of sample-data-blocks and ensure a minimum
413 * of CPUM_SF_MIN_SDB. Also ensure the upper limit does not
414 * exceed a "calculated" maximum. The symbolic maximum is
415 * designed for basic-sampling only and needs to be increased if
416 * diagnostic-sampling is active.
417 * See also the remarks for these symbolic constants.
419 * 4. Compute the number of sample-data-block-tables (SDBT) and
420 * ensure a minimum of CPUM_SF_MIN_SDBT (one table can manage up
423 sample_size
= event_sample_size(hwc
);
424 freq
= sample_rate_to_freq(&cpuhw
->qsi
, SAMPL_RATE(hwc
));
426 n_sdb
= DIV_ROUND_UP(freq
, factor
* ((PAGE_SIZE
-64) / sample_size
));
427 if (n_sdb
< CPUM_SF_MIN_SDB
)
428 n_sdb
= CPUM_SF_MIN_SDB
;
430 /* If there is already a sampling buffer allocated, it is very likely
431 * that the sampling facility is enabled too. If the event to be
432 * initialized requires a greater sampling buffer, the allocation must
433 * be postponed. Changing the sampling buffer requires the sampling
434 * facility to be in the disabled state. So, account the number of
435 * required SDBs and let cpumsf_pmu_enable() resize the buffer just
436 * before the event is started.
438 sfb_init_allocs(n_sdb
, hwc
);
439 if (sf_buffer_available(cpuhw
))
442 debug_sprintf_event(sfdbg
, 3,
443 "allocate_buffers: rate=%lu f=%lu sdb=%lu/%lu"
444 " sample_size=%lu cpuhw=%p\n",
445 SAMPL_RATE(hwc
), freq
, n_sdb
, sfb_max_limit(hwc
),
448 return alloc_sampling_buffer(&cpuhw
->sfb
,
449 sfb_pending_allocs(&cpuhw
->sfb
, hwc
));
452 static unsigned long min_percent(unsigned int percent
, unsigned long base
,
455 return min_t(unsigned long, min
, DIV_ROUND_UP(percent
* base
, 100));
458 static unsigned long compute_sfb_extent(unsigned long ratio
, unsigned long base
)
460 /* Use a percentage-based approach to extend the sampling facility
461 * buffer. Accept up to 5% sample data loss.
462 * Vary the extents between 1% to 5% of the current number of
463 * sample-data-blocks.
468 return min_percent(1, base
, 1);
470 return min_percent(1, base
, 1);
472 return min_percent(2, base
, 2);
474 return min_percent(3, base
, 3);
476 return min_percent(4, base
, 4);
478 return min_percent(5, base
, 8);
481 static void sfb_account_overflows(struct cpu_hw_sf
*cpuhw
,
482 struct hw_perf_event
*hwc
)
484 unsigned long ratio
, num
;
486 if (!OVERFLOW_REG(hwc
))
489 /* The sample_overflow contains the average number of sample data
490 * that has been lost because sample-data-blocks were full.
492 * Calculate the total number of sample data entries that has been
493 * discarded. Then calculate the ratio of lost samples to total samples
494 * per second in percent.
496 ratio
= DIV_ROUND_UP(100 * OVERFLOW_REG(hwc
) * cpuhw
->sfb
.num_sdb
,
497 sample_rate_to_freq(&cpuhw
->qsi
, SAMPL_RATE(hwc
)));
499 /* Compute number of sample-data-blocks */
500 num
= compute_sfb_extent(ratio
, cpuhw
->sfb
.num_sdb
);
502 sfb_account_allocs(num
, hwc
);
504 debug_sprintf_event(sfdbg
, 5, "sfb: overflow: overflow=%llu ratio=%lu"
505 " num=%lu\n", OVERFLOW_REG(hwc
), ratio
, num
);
506 OVERFLOW_REG(hwc
) = 0;
509 /* extend_sampling_buffer() - Extend sampling buffer
510 * @sfb: Sampling buffer structure (for local CPU)
511 * @hwc: Perf event hardware structure
513 * Use this function to extend the sampling buffer based on the overflow counter
514 * and postponed allocation extents stored in the specified Perf event hardware.
516 * Important: This function disables the sampling facility in order to safely
517 * change the sampling buffer structure. Do not call this function
518 * when the PMU is active.
520 static void extend_sampling_buffer(struct sf_buffer
*sfb
,
521 struct hw_perf_event
*hwc
)
523 unsigned long num
, num_old
;
526 num
= sfb_pending_allocs(sfb
, hwc
);
529 num_old
= sfb
->num_sdb
;
531 /* Disable the sampling facility to reset any states and also
532 * clear pending measurement alerts.
536 /* Extend the sampling buffer.
537 * This memory allocation typically happens in an atomic context when
538 * called by perf. Because this is a reallocation, it is fine if the
539 * new SDB-request cannot be satisfied immediately.
541 rc
= realloc_sampling_buffer(sfb
, num
, GFP_ATOMIC
);
543 debug_sprintf_event(sfdbg
, 5, "sfb: extend: realloc "
544 "failed with rc=%i\n", rc
);
546 if (sfb_has_pending_allocs(sfb
, hwc
))
547 debug_sprintf_event(sfdbg
, 5, "sfb: extend: "
548 "req=%lu alloc=%lu remaining=%lu\n",
549 num
, sfb
->num_sdb
- num_old
,
550 sfb_pending_allocs(sfb
, hwc
));
554 /* Number of perf events counting hardware events */
555 static atomic_t num_events
;
556 /* Used to avoid races in calling reserve/release_cpumf_hardware */
557 static DEFINE_MUTEX(pmc_reserve_mutex
);
560 #define PMC_RELEASE 1
561 #define PMC_FAILURE 2
562 static void setup_pmc_cpu(void *flags
)
565 struct cpu_hw_sf
*cpusf
= this_cpu_ptr(&cpu_hw_sf
);
568 switch (*((int *) flags
)) {
570 memset(cpusf
, 0, sizeof(*cpusf
));
571 err
= qsi(&cpusf
->qsi
);
574 cpusf
->flags
|= PMU_F_RESERVED
;
577 pr_err("Switching off the sampling facility failed "
578 "with rc=%i\n", err
);
579 debug_sprintf_event(sfdbg
, 5,
580 "setup_pmc_cpu: initialized: cpuhw=%p\n", cpusf
);
583 cpusf
->flags
&= ~PMU_F_RESERVED
;
586 pr_err("Switching off the sampling facility failed "
587 "with rc=%i\n", err
);
589 deallocate_buffers(cpusf
);
590 debug_sprintf_event(sfdbg
, 5,
591 "setup_pmc_cpu: released: cpuhw=%p\n", cpusf
);
595 *((int *) flags
) |= PMC_FAILURE
;
598 static void release_pmc_hardware(void)
600 int flags
= PMC_RELEASE
;
602 irq_subclass_unregister(IRQ_SUBCLASS_MEASUREMENT_ALERT
);
603 on_each_cpu(setup_pmc_cpu
, &flags
, 1);
604 perf_release_sampling();
607 static int reserve_pmc_hardware(void)
609 int flags
= PMC_INIT
;
612 err
= perf_reserve_sampling();
615 on_each_cpu(setup_pmc_cpu
, &flags
, 1);
616 if (flags
& PMC_FAILURE
) {
617 release_pmc_hardware();
620 irq_subclass_register(IRQ_SUBCLASS_MEASUREMENT_ALERT
);
625 static void hw_perf_event_destroy(struct perf_event
*event
)
627 /* Free raw sample buffer */
628 if (RAWSAMPLE_REG(&event
->hw
))
629 kfree((void *) RAWSAMPLE_REG(&event
->hw
));
631 /* Release PMC if this is the last perf event */
632 if (!atomic_add_unless(&num_events
, -1, 1)) {
633 mutex_lock(&pmc_reserve_mutex
);
634 if (atomic_dec_return(&num_events
) == 0)
635 release_pmc_hardware();
636 mutex_unlock(&pmc_reserve_mutex
);
640 static void hw_init_period(struct hw_perf_event
*hwc
, u64 period
)
642 hwc
->sample_period
= period
;
643 hwc
->last_period
= hwc
->sample_period
;
644 local64_set(&hwc
->period_left
, hwc
->sample_period
);
647 static void hw_reset_registers(struct hw_perf_event
*hwc
,
648 unsigned long *sdbt_origin
)
650 struct sf_raw_sample
*sfr
;
652 /* (Re)set to first sample-data-block-table */
653 TEAR_REG(hwc
) = (unsigned long) sdbt_origin
;
655 /* (Re)set raw sampling buffer register */
656 sfr
= (struct sf_raw_sample
*) RAWSAMPLE_REG(hwc
);
657 memset(&sfr
->basic
, 0, sizeof(sfr
->basic
));
658 memset(&sfr
->diag
, 0, sfr
->dsdes
);
661 static unsigned long hw_limit_rate(const struct hws_qsi_info_block
*si
,
664 return clamp_t(unsigned long, rate
,
665 si
->min_sampl_rate
, si
->max_sampl_rate
);
668 static int __hw_perf_event_init(struct perf_event
*event
)
670 struct cpu_hw_sf
*cpuhw
;
671 struct hws_qsi_info_block si
;
672 struct perf_event_attr
*attr
= &event
->attr
;
673 struct hw_perf_event
*hwc
= &event
->hw
;
677 /* Reserve CPU-measurement sampling facility */
679 if (!atomic_inc_not_zero(&num_events
)) {
680 mutex_lock(&pmc_reserve_mutex
);
681 if (atomic_read(&num_events
) == 0 && reserve_pmc_hardware())
684 atomic_inc(&num_events
);
685 mutex_unlock(&pmc_reserve_mutex
);
687 event
->destroy
= hw_perf_event_destroy
;
692 /* Access per-CPU sampling information (query sampling info) */
694 * The event->cpu value can be -1 to count on every CPU, for example,
695 * when attaching to a task. If this is specified, use the query
696 * sampling info from the current CPU, otherwise use event->cpu to
697 * retrieve the per-CPU information.
698 * Later, cpuhw indicates whether to allocate sampling buffers for a
699 * particular CPU (cpuhw!=NULL) or each online CPU (cpuw==NULL).
701 memset(&si
, 0, sizeof(si
));
703 if (event
->cpu
== -1)
706 /* Event is pinned to a particular CPU, retrieve the per-CPU
707 * sampling structure for accessing the CPU-specific QSI.
709 cpuhw
= &per_cpu(cpu_hw_sf
, event
->cpu
);
713 /* Check sampling facility authorization and, if not authorized,
714 * fall back to other PMUs. It is safe to check any CPU because
715 * the authorization is identical for all configured CPUs.
722 /* Always enable basic sampling */
723 SAMPL_FLAGS(hwc
) = PERF_CPUM_SF_BASIC_MODE
;
725 /* Check if diagnostic sampling is requested. Deny if the required
726 * sampling authorization is missing.
728 if (attr
->config
== PERF_EVENT_CPUM_SF_DIAG
) {
733 SAMPL_FLAGS(hwc
) |= PERF_CPUM_SF_DIAG_MODE
;
736 /* Check and set other sampling flags */
737 if (attr
->config1
& PERF_CPUM_SF_FULL_BLOCKS
)
738 SAMPL_FLAGS(hwc
) |= PERF_CPUM_SF_FULL_BLOCKS
;
740 /* The sampling information (si) contains information about the
741 * min/max sampling intervals and the CPU speed. So calculate the
742 * correct sampling interval and avoid the whole period adjust
747 rate
= freq_to_sample_rate(&si
, attr
->sample_freq
);
748 rate
= hw_limit_rate(&si
, rate
);
750 attr
->sample_period
= rate
;
752 /* The min/max sampling rates specifies the valid range
753 * of sample periods. If the specified sample period is
754 * out of range, limit the period to the range boundary.
756 rate
= hw_limit_rate(&si
, hwc
->sample_period
);
758 /* The perf core maintains a maximum sample rate that is
759 * configurable through the sysctl interface. Ensure the
760 * sampling rate does not exceed this value. This also helps
761 * to avoid throttling when pushing samples with
762 * perf_event_overflow().
764 if (sample_rate_to_freq(&si
, rate
) >
765 sysctl_perf_event_sample_rate
) {
767 debug_sprintf_event(sfdbg
, 1, "Sampling rate exceeds maximum perf sample rate\n");
771 SAMPL_RATE(hwc
) = rate
;
772 hw_init_period(hwc
, SAMPL_RATE(hwc
));
774 /* Initialize sample data overflow accounting */
775 hwc
->extra_reg
.reg
= REG_OVERFLOW
;
776 OVERFLOW_REG(hwc
) = 0;
778 /* Allocate the per-CPU sampling buffer using the CPU information
779 * from the event. If the event is not pinned to a particular
780 * CPU (event->cpu == -1; or cpuhw == NULL), allocate sampling
781 * buffers for each online CPU.
784 /* Event is pinned to a particular CPU */
785 err
= allocate_buffers(cpuhw
, hwc
);
787 /* Event is not pinned, allocate sampling buffer on
790 for_each_online_cpu(cpu
) {
791 cpuhw
= &per_cpu(cpu_hw_sf
, cpu
);
792 err
= allocate_buffers(cpuhw
, hwc
);
801 static int cpumsf_pmu_event_init(struct perf_event
*event
)
805 /* No support for taken branch sampling */
806 if (has_branch_stack(event
))
809 switch (event
->attr
.type
) {
811 if ((event
->attr
.config
!= PERF_EVENT_CPUM_SF
) &&
812 (event
->attr
.config
!= PERF_EVENT_CPUM_SF_DIAG
))
815 case PERF_TYPE_HARDWARE
:
816 /* Support sampling of CPU cycles in addition to the
817 * counter facility. However, the counter facility
818 * is more precise and, hence, restrict this PMU to
819 * sampling events only.
821 if (event
->attr
.config
!= PERF_COUNT_HW_CPU_CYCLES
)
823 if (!is_sampling_event(event
))
830 /* Check online status of the CPU to which the event is pinned */
831 if (event
->cpu
>= nr_cpumask_bits
||
832 (event
->cpu
>= 0 && !cpu_online(event
->cpu
)))
835 /* Force reset of idle/hv excludes regardless of what the
838 if (event
->attr
.exclude_hv
)
839 event
->attr
.exclude_hv
= 0;
840 if (event
->attr
.exclude_idle
)
841 event
->attr
.exclude_idle
= 0;
843 err
= __hw_perf_event_init(event
);
846 event
->destroy(event
);
850 static void cpumsf_pmu_enable(struct pmu
*pmu
)
852 struct cpu_hw_sf
*cpuhw
= this_cpu_ptr(&cpu_hw_sf
);
853 struct hw_perf_event
*hwc
;
856 if (cpuhw
->flags
& PMU_F_ENABLED
)
859 if (cpuhw
->flags
& PMU_F_ERR_MASK
)
862 /* Check whether to extent the sampling buffer.
864 * Two conditions trigger an increase of the sampling buffer for a
866 * 1. Postponed buffer allocations from the event initialization.
867 * 2. Sampling overflows that contribute to pending allocations.
869 * Note that the extend_sampling_buffer() function disables the sampling
870 * facility, but it can be fully re-enabled using sampling controls that
871 * have been saved in cpumsf_pmu_disable().
874 hwc
= &cpuhw
->event
->hw
;
875 /* Account number of overflow-designated buffer extents */
876 sfb_account_overflows(cpuhw
, hwc
);
877 if (sfb_has_pending_allocs(&cpuhw
->sfb
, hwc
))
878 extend_sampling_buffer(&cpuhw
->sfb
, hwc
);
881 /* (Re)enable the PMU and sampling facility */
882 cpuhw
->flags
|= PMU_F_ENABLED
;
885 err
= lsctl(&cpuhw
->lsctl
);
887 cpuhw
->flags
&= ~PMU_F_ENABLED
;
888 pr_err("Loading sampling controls failed: op=%i err=%i\n",
893 debug_sprintf_event(sfdbg
, 6, "pmu_enable: es=%i cs=%i ed=%i cd=%i "
894 "tear=%p dear=%p\n", cpuhw
->lsctl
.es
, cpuhw
->lsctl
.cs
,
895 cpuhw
->lsctl
.ed
, cpuhw
->lsctl
.cd
,
896 (void *) cpuhw
->lsctl
.tear
, (void *) cpuhw
->lsctl
.dear
);
899 static void cpumsf_pmu_disable(struct pmu
*pmu
)
901 struct cpu_hw_sf
*cpuhw
= this_cpu_ptr(&cpu_hw_sf
);
902 struct hws_lsctl_request_block inactive
;
903 struct hws_qsi_info_block si
;
906 if (!(cpuhw
->flags
& PMU_F_ENABLED
))
909 if (cpuhw
->flags
& PMU_F_ERR_MASK
)
912 /* Switch off sampling activation control */
913 inactive
= cpuhw
->lsctl
;
917 err
= lsctl(&inactive
);
919 pr_err("Loading sampling controls failed: op=%i err=%i\n",
924 /* Save state of TEAR and DEAR register contents */
926 /* TEAR/DEAR values are valid only if the sampling facility is
927 * enabled. Note that cpumsf_pmu_disable() might be called even
928 * for a disabled sampling facility because cpumsf_pmu_enable()
929 * controls the enable/disable state.
932 cpuhw
->lsctl
.tear
= si
.tear
;
933 cpuhw
->lsctl
.dear
= si
.dear
;
936 debug_sprintf_event(sfdbg
, 3, "cpumsf_pmu_disable: "
937 "qsi() failed with err=%i\n", err
);
939 cpuhw
->flags
&= ~PMU_F_ENABLED
;
942 /* perf_exclude_event() - Filter event
943 * @event: The perf event
944 * @regs: pt_regs structure
945 * @sde_regs: Sample-data-entry (sde) regs structure
947 * Filter perf events according to their exclude specification.
949 * Return non-zero if the event shall be excluded.
951 static int perf_exclude_event(struct perf_event
*event
, struct pt_regs
*regs
,
952 struct perf_sf_sde_regs
*sde_regs
)
954 if (event
->attr
.exclude_user
&& user_mode(regs
))
956 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
958 if (event
->attr
.exclude_guest
&& sde_regs
->in_guest
)
960 if (event
->attr
.exclude_host
&& !sde_regs
->in_guest
)
965 /* perf_push_sample() - Push samples to perf
966 * @event: The perf event
967 * @sample: Hardware sample data
969 * Use the hardware sample data to create perf event sample. The sample
970 * is the pushed to the event subsystem and the function checks for
971 * possible event overflows. If an event overflow occurs, the PMU is
974 * Return non-zero if an event overflow occurred.
976 static int perf_push_sample(struct perf_event
*event
, struct sf_raw_sample
*sfr
)
980 struct perf_sf_sde_regs
*sde_regs
;
981 struct perf_sample_data data
;
982 struct perf_raw_record raw
;
984 /* Setup perf sample */
985 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
986 raw
.size
= sfr
->size
;
990 /* Setup pt_regs to look like an CPU-measurement external interrupt
991 * using the Program Request Alert code. The regs.int_parm_long
992 * field which is unused contains additional sample-data-entry related
995 memset(®s
, 0, sizeof(regs
));
996 regs
.int_code
= 0x1407;
997 regs
.int_parm
= CPU_MF_INT_SF_PRA
;
998 sde_regs
= (struct perf_sf_sde_regs
*) ®s
.int_parm_long
;
1000 regs
.psw
.addr
= sfr
->basic
.ia
;
1002 regs
.psw
.mask
|= PSW_MASK_DAT
;
1004 regs
.psw
.mask
|= PSW_MASK_WAIT
;
1006 regs
.psw
.mask
|= PSW_MASK_PSTATE
;
1007 switch (sfr
->basic
.AS
) {
1009 regs
.psw
.mask
|= PSW_ASC_PRIMARY
;
1012 regs
.psw
.mask
|= PSW_ASC_ACCREG
;
1015 regs
.psw
.mask
|= PSW_ASC_SECONDARY
;
1018 regs
.psw
.mask
|= PSW_ASC_HOME
;
1022 /* The host-program-parameter (hpp) contains the sie control
1023 * block that is set by sie64a() in entry64.S. Check if hpp
1024 * refers to a valid control block and set sde_regs flags
1025 * accordingly. This would allow to use hpp values for other
1027 * For now, simply use a non-zero value as guest indicator.
1030 sde_regs
->in_guest
= 1;
1033 if (perf_exclude_event(event
, ®s
, sde_regs
))
1035 if (perf_event_overflow(event
, &data
, ®s
)) {
1037 event
->pmu
->stop(event
, 0);
1039 perf_event_update_userpage(event
);
1044 static void perf_event_count_update(struct perf_event
*event
, u64 count
)
1046 local64_add(count
, &event
->count
);
1049 static int sample_format_is_valid(struct hws_combined_entry
*sample
,
1052 if (likely(flags
& PERF_CPUM_SF_BASIC_MODE
))
1053 /* Only basic-sampling data entries with data-entry-format
1054 * version of 0x0001 can be processed.
1056 if (sample
->basic
.def
!= 0x0001)
1058 if (flags
& PERF_CPUM_SF_DIAG_MODE
)
1059 /* The data-entry-format number of diagnostic-sampling data
1060 * entries can vary. Because diagnostic data is just passed
1061 * through, do only a sanity check on the DEF.
1063 if (sample
->diag
.def
< 0x8001)
1068 static int sample_is_consistent(struct hws_combined_entry
*sample
,
1069 unsigned long flags
)
1071 /* This check applies only to basic-sampling data entries of potentially
1072 * combined-sampling data entries. Invalid entries cannot be processed
1073 * by the PMU and, thus, do not deliver an associated
1074 * diagnostic-sampling data entry.
1076 if (unlikely(!(flags
& PERF_CPUM_SF_BASIC_MODE
)))
1079 * Samples are skipped, if they are invalid or for which the
1080 * instruction address is not predictable, i.e., the wait-state bit is
1083 if (sample
->basic
.I
|| sample
->basic
.W
)
1088 static void reset_sample_slot(struct hws_combined_entry
*sample
,
1089 unsigned long flags
)
1091 if (likely(flags
& PERF_CPUM_SF_BASIC_MODE
))
1092 sample
->basic
.def
= 0;
1093 if (flags
& PERF_CPUM_SF_DIAG_MODE
)
1094 sample
->diag
.def
= 0;
1097 static void sfr_store_sample(struct sf_raw_sample
*sfr
,
1098 struct hws_combined_entry
*sample
)
1100 if (likely(sfr
->format
& PERF_CPUM_SF_BASIC_MODE
))
1101 sfr
->basic
= sample
->basic
;
1102 if (sfr
->format
& PERF_CPUM_SF_DIAG_MODE
)
1103 memcpy(&sfr
->diag
, &sample
->diag
, sfr
->dsdes
);
1106 static void debug_sample_entry(struct hws_combined_entry
*sample
,
1107 struct hws_trailer_entry
*te
,
1108 unsigned long flags
)
1110 debug_sprintf_event(sfdbg
, 4, "hw_collect_samples: Found unknown "
1111 "sampling data entry: te->f=%i basic.def=%04x (%p)"
1112 " diag.def=%04x (%p)\n", te
->f
,
1113 sample
->basic
.def
, &sample
->basic
,
1114 (flags
& PERF_CPUM_SF_DIAG_MODE
)
1115 ? sample
->diag
.def
: 0xFFFF,
1116 (flags
& PERF_CPUM_SF_DIAG_MODE
)
1117 ? &sample
->diag
: NULL
);
1120 /* hw_collect_samples() - Walk through a sample-data-block and collect samples
1121 * @event: The perf event
1122 * @sdbt: Sample-data-block table
1123 * @overflow: Event overflow counter
1125 * Walks through a sample-data-block and collects sampling data entries that are
1126 * then pushed to the perf event subsystem. Depending on the sampling function,
1127 * there can be either basic-sampling or combined-sampling data entries. A
1128 * combined-sampling data entry consists of a basic- and a diagnostic-sampling
1129 * data entry. The sampling function is determined by the flags in the perf
1130 * event hardware structure. The function always works with a combined-sampling
1131 * data entry but ignores the the diagnostic portion if it is not available.
1133 * Note that the implementation focuses on basic-sampling data entries and, if
1134 * such an entry is not valid, the entire combined-sampling data entry is
1137 * The overflow variables counts the number of samples that has been discarded
1138 * due to a perf event overflow.
1140 static void hw_collect_samples(struct perf_event
*event
, unsigned long *sdbt
,
1141 unsigned long long *overflow
)
1143 unsigned long flags
= SAMPL_FLAGS(&event
->hw
);
1144 struct hws_combined_entry
*sample
;
1145 struct hws_trailer_entry
*te
;
1146 struct sf_raw_sample
*sfr
;
1149 /* Prepare and initialize raw sample data */
1150 sfr
= (struct sf_raw_sample
*) RAWSAMPLE_REG(&event
->hw
);
1151 sfr
->format
= flags
& PERF_CPUM_SF_MODE_MASK
;
1153 sample_size
= event_sample_size(&event
->hw
);
1154 te
= (struct hws_trailer_entry
*) trailer_entry_ptr(*sdbt
);
1155 sample
= (struct hws_combined_entry
*) *sdbt
;
1156 while ((unsigned long *) sample
< (unsigned long *) te
) {
1157 /* Check for an empty sample */
1158 if (!sample
->basic
.def
)
1161 /* Update perf event period */
1162 perf_event_count_update(event
, SAMPL_RATE(&event
->hw
));
1164 /* Check sampling data entry */
1165 if (sample_format_is_valid(sample
, flags
)) {
1166 /* If an event overflow occurred, the PMU is stopped to
1167 * throttle event delivery. Remaining sample data is
1171 if (sample_is_consistent(sample
, flags
)) {
1172 /* Deliver sample data to perf */
1173 sfr_store_sample(sfr
, sample
);
1174 *overflow
= perf_push_sample(event
, sfr
);
1177 /* Count discarded samples */
1180 debug_sample_entry(sample
, te
, flags
);
1181 /* Sample slot is not yet written or other record.
1183 * This condition can occur if the buffer was reused
1184 * from a combined basic- and diagnostic-sampling.
1185 * If only basic-sampling is then active, entries are
1186 * written into the larger diagnostic entries.
1187 * This is typically the case for sample-data-blocks
1188 * that are not full. Stop processing if the first
1189 * invalid format was detected.
1195 /* Reset sample slot and advance to next sample */
1196 reset_sample_slot(sample
, flags
);
1197 sample
+= sample_size
;
1201 /* hw_perf_event_update() - Process sampling buffer
1202 * @event: The perf event
1203 * @flush_all: Flag to also flush partially filled sample-data-blocks
1205 * Processes the sampling buffer and create perf event samples.
1206 * The sampling buffer position are retrieved and saved in the TEAR_REG
1207 * register of the specified perf event.
1209 * Only full sample-data-blocks are processed. Specify the flash_all flag
1210 * to also walk through partially filled sample-data-blocks. It is ignored
1211 * if PERF_CPUM_SF_FULL_BLOCKS is set. The PERF_CPUM_SF_FULL_BLOCKS flag
1212 * enforces the processing of full sample-data-blocks only (trailer entries
1213 * with the block-full-indicator bit set).
1215 static void hw_perf_event_update(struct perf_event
*event
, int flush_all
)
1217 struct hw_perf_event
*hwc
= &event
->hw
;
1218 struct hws_trailer_entry
*te
;
1219 unsigned long *sdbt
;
1220 unsigned long long event_overflow
, sampl_overflow
, num_sdb
, te_flags
;
1223 if (flush_all
&& SDB_FULL_BLOCKS(hwc
))
1226 sdbt
= (unsigned long *) TEAR_REG(hwc
);
1227 done
= event_overflow
= sampl_overflow
= num_sdb
= 0;
1229 /* Get the trailer entry of the sample-data-block */
1230 te
= (struct hws_trailer_entry
*) trailer_entry_ptr(*sdbt
);
1232 /* Leave loop if no more work to do (block full indicator) */
1239 /* Check the sample overflow count */
1241 /* Account sample overflows and, if a particular limit
1242 * is reached, extend the sampling buffer.
1243 * For details, see sfb_account_overflows().
1245 sampl_overflow
+= te
->overflow
;
1247 /* Timestamps are valid for full sample-data-blocks only */
1248 debug_sprintf_event(sfdbg
, 6, "hw_perf_event_update: sdbt=%p "
1249 "overflow=%llu timestamp=0x%llx\n",
1251 (te
->f
) ? trailer_timestamp(te
) : 0ULL);
1253 /* Collect all samples from a single sample-data-block and
1254 * flag if an (perf) event overflow happened. If so, the PMU
1255 * is stopped and remaining samples will be discarded.
1257 hw_collect_samples(event
, sdbt
, &event_overflow
);
1260 /* Reset trailer (using compare-double-and-swap) */
1262 te_flags
= te
->flags
& ~SDB_TE_BUFFER_FULL_MASK
;
1263 te_flags
|= SDB_TE_ALERT_REQ_MASK
;
1264 } while (!cmpxchg_double(&te
->flags
, &te
->overflow
,
1265 te
->flags
, te
->overflow
,
1268 /* Advance to next sample-data-block */
1270 if (is_link_entry(sdbt
))
1271 sdbt
= get_next_sdbt(sdbt
);
1273 /* Update event hardware registers */
1274 TEAR_REG(hwc
) = (unsigned long) sdbt
;
1276 /* Stop processing sample-data if all samples of the current
1277 * sample-data-block were flushed even if it was not full.
1279 if (flush_all
&& done
)
1282 /* If an event overflow happened, discard samples by
1283 * processing any remaining sample-data-blocks.
1289 /* Account sample overflows in the event hardware structure */
1291 OVERFLOW_REG(hwc
) = DIV_ROUND_UP(OVERFLOW_REG(hwc
) +
1292 sampl_overflow
, 1 + num_sdb
);
1293 if (sampl_overflow
|| event_overflow
)
1294 debug_sprintf_event(sfdbg
, 4, "hw_perf_event_update: "
1295 "overflow stats: sample=%llu event=%llu\n",
1296 sampl_overflow
, event_overflow
);
1299 static void cpumsf_pmu_read(struct perf_event
*event
)
1301 /* Nothing to do ... updates are interrupt-driven */
1304 /* Activate sampling control.
1305 * Next call of pmu_enable() starts sampling.
1307 static void cpumsf_pmu_start(struct perf_event
*event
, int flags
)
1309 struct cpu_hw_sf
*cpuhw
= this_cpu_ptr(&cpu_hw_sf
);
1311 if (WARN_ON_ONCE(!(event
->hw
.state
& PERF_HES_STOPPED
)))
1314 if (flags
& PERF_EF_RELOAD
)
1315 WARN_ON_ONCE(!(event
->hw
.state
& PERF_HES_UPTODATE
));
1317 perf_pmu_disable(event
->pmu
);
1318 event
->hw
.state
= 0;
1319 cpuhw
->lsctl
.cs
= 1;
1320 if (SAMPL_DIAG_MODE(&event
->hw
))
1321 cpuhw
->lsctl
.cd
= 1;
1322 perf_pmu_enable(event
->pmu
);
1325 /* Deactivate sampling control.
1326 * Next call of pmu_enable() stops sampling.
1328 static void cpumsf_pmu_stop(struct perf_event
*event
, int flags
)
1330 struct cpu_hw_sf
*cpuhw
= this_cpu_ptr(&cpu_hw_sf
);
1332 if (event
->hw
.state
& PERF_HES_STOPPED
)
1335 perf_pmu_disable(event
->pmu
);
1336 cpuhw
->lsctl
.cs
= 0;
1337 cpuhw
->lsctl
.cd
= 0;
1338 event
->hw
.state
|= PERF_HES_STOPPED
;
1340 if ((flags
& PERF_EF_UPDATE
) && !(event
->hw
.state
& PERF_HES_UPTODATE
)) {
1341 hw_perf_event_update(event
, 1);
1342 event
->hw
.state
|= PERF_HES_UPTODATE
;
1344 perf_pmu_enable(event
->pmu
);
1347 static int cpumsf_pmu_add(struct perf_event
*event
, int flags
)
1349 struct cpu_hw_sf
*cpuhw
= this_cpu_ptr(&cpu_hw_sf
);
1352 if (cpuhw
->flags
& PMU_F_IN_USE
)
1355 if (!cpuhw
->sfb
.sdbt
)
1359 perf_pmu_disable(event
->pmu
);
1361 event
->hw
.state
= PERF_HES_UPTODATE
| PERF_HES_STOPPED
;
1363 /* Set up sampling controls. Always program the sampling register
1364 * using the SDB-table start. Reset TEAR_REG event hardware register
1365 * that is used by hw_perf_event_update() to store the sampling buffer
1366 * position after samples have been flushed.
1370 cpuhw
->lsctl
.tear
= (unsigned long) cpuhw
->sfb
.sdbt
;
1371 cpuhw
->lsctl
.dear
= *(unsigned long *) cpuhw
->sfb
.sdbt
;
1372 cpuhw
->lsctl
.interval
= SAMPL_RATE(&event
->hw
);
1373 hw_reset_registers(&event
->hw
, cpuhw
->sfb
.sdbt
);
1375 /* Ensure sampling functions are in the disabled state. If disabled,
1376 * switch on sampling enable control. */
1377 if (WARN_ON_ONCE(cpuhw
->lsctl
.es
== 1 || cpuhw
->lsctl
.ed
== 1)) {
1381 cpuhw
->lsctl
.es
= 1;
1382 if (SAMPL_DIAG_MODE(&event
->hw
))
1383 cpuhw
->lsctl
.ed
= 1;
1385 /* Set in_use flag and store event */
1386 cpuhw
->event
= event
;
1387 cpuhw
->flags
|= PMU_F_IN_USE
;
1389 if (flags
& PERF_EF_START
)
1390 cpumsf_pmu_start(event
, PERF_EF_RELOAD
);
1392 perf_event_update_userpage(event
);
1393 perf_pmu_enable(event
->pmu
);
1397 static void cpumsf_pmu_del(struct perf_event
*event
, int flags
)
1399 struct cpu_hw_sf
*cpuhw
= this_cpu_ptr(&cpu_hw_sf
);
1401 perf_pmu_disable(event
->pmu
);
1402 cpumsf_pmu_stop(event
, PERF_EF_UPDATE
);
1404 cpuhw
->lsctl
.es
= 0;
1405 cpuhw
->lsctl
.ed
= 0;
1406 cpuhw
->flags
&= ~PMU_F_IN_USE
;
1407 cpuhw
->event
= NULL
;
1409 perf_event_update_userpage(event
);
1410 perf_pmu_enable(event
->pmu
);
1413 CPUMF_EVENT_ATTR(SF
, SF_CYCLES_BASIC
, PERF_EVENT_CPUM_SF
);
1414 CPUMF_EVENT_ATTR(SF
, SF_CYCLES_BASIC_DIAG
, PERF_EVENT_CPUM_SF_DIAG
);
1416 static struct attribute
*cpumsf_pmu_events_attr
[] = {
1417 CPUMF_EVENT_PTR(SF
, SF_CYCLES_BASIC
),
1422 PMU_FORMAT_ATTR(event
, "config:0-63");
1424 static struct attribute
*cpumsf_pmu_format_attr
[] = {
1425 &format_attr_event
.attr
,
1429 static struct attribute_group cpumsf_pmu_events_group
= {
1431 .attrs
= cpumsf_pmu_events_attr
,
1433 static struct attribute_group cpumsf_pmu_format_group
= {
1435 .attrs
= cpumsf_pmu_format_attr
,
1437 static const struct attribute_group
*cpumsf_pmu_attr_groups
[] = {
1438 &cpumsf_pmu_events_group
,
1439 &cpumsf_pmu_format_group
,
1443 static struct pmu cpumf_sampling
= {
1444 .pmu_enable
= cpumsf_pmu_enable
,
1445 .pmu_disable
= cpumsf_pmu_disable
,
1447 .event_init
= cpumsf_pmu_event_init
,
1448 .add
= cpumsf_pmu_add
,
1449 .del
= cpumsf_pmu_del
,
1451 .start
= cpumsf_pmu_start
,
1452 .stop
= cpumsf_pmu_stop
,
1453 .read
= cpumsf_pmu_read
,
1455 .attr_groups
= cpumsf_pmu_attr_groups
,
1458 static void cpumf_measurement_alert(struct ext_code ext_code
,
1459 unsigned int alert
, unsigned long unused
)
1461 struct cpu_hw_sf
*cpuhw
;
1463 if (!(alert
& CPU_MF_INT_SF_MASK
))
1465 inc_irq_stat(IRQEXT_CMS
);
1466 cpuhw
= this_cpu_ptr(&cpu_hw_sf
);
1468 /* Measurement alerts are shared and might happen when the PMU
1469 * is not reserved. Ignore these alerts in this case. */
1470 if (!(cpuhw
->flags
& PMU_F_RESERVED
))
1473 /* The processing below must take care of multiple alert events that
1474 * might be indicated concurrently. */
1476 /* Program alert request */
1477 if (alert
& CPU_MF_INT_SF_PRA
) {
1478 if (cpuhw
->flags
& PMU_F_IN_USE
)
1479 hw_perf_event_update(cpuhw
->event
, 0);
1481 WARN_ON_ONCE(!(cpuhw
->flags
& PMU_F_IN_USE
));
1484 /* Report measurement alerts only for non-PRA codes */
1485 if (alert
!= CPU_MF_INT_SF_PRA
)
1486 debug_sprintf_event(sfdbg
, 6, "measurement alert: 0x%x\n", alert
);
1488 /* Sampling authorization change request */
1489 if (alert
& CPU_MF_INT_SF_SACA
)
1492 /* Loss of sample data due to high-priority machine activities */
1493 if (alert
& CPU_MF_INT_SF_LSDA
) {
1494 pr_err("Sample data was lost\n");
1495 cpuhw
->flags
|= PMU_F_ERR_LSDA
;
1499 /* Invalid sampling buffer entry */
1500 if (alert
& (CPU_MF_INT_SF_IAE
|CPU_MF_INT_SF_ISE
)) {
1501 pr_err("A sampling buffer entry is incorrect (alert=0x%x)\n",
1503 cpuhw
->flags
|= PMU_F_ERR_IBE
;
1508 static int cpumf_pmu_notifier(struct notifier_block
*self
,
1509 unsigned long action
, void *hcpu
)
1511 unsigned int cpu
= (long) hcpu
;
1514 /* Ignore the notification if no events are scheduled on the PMU.
1515 * This might be racy...
1517 if (!atomic_read(&num_events
))
1520 switch (action
& ~CPU_TASKS_FROZEN
) {
1522 case CPU_ONLINE_FROZEN
:
1524 smp_call_function_single(cpu
, setup_pmc_cpu
, &flags
, 1);
1526 case CPU_DOWN_PREPARE
:
1527 flags
= PMC_RELEASE
;
1528 smp_call_function_single(cpu
, setup_pmc_cpu
, &flags
, 1);
1537 static int param_get_sfb_size(char *buffer
, const struct kernel_param
*kp
)
1539 if (!cpum_sf_avail())
1541 return sprintf(buffer
, "%lu,%lu", CPUM_SF_MIN_SDB
, CPUM_SF_MAX_SDB
);
1544 static int param_set_sfb_size(const char *val
, const struct kernel_param
*kp
)
1547 unsigned long min
, max
;
1549 if (!cpum_sf_avail())
1551 if (!val
|| !strlen(val
))
1554 /* Valid parameter values: "min,max" or "max" */
1555 min
= CPUM_SF_MIN_SDB
;
1556 max
= CPUM_SF_MAX_SDB
;
1557 if (strchr(val
, ','))
1558 rc
= (sscanf(val
, "%lu,%lu", &min
, &max
) == 2) ? 0 : -EINVAL
;
1560 rc
= kstrtoul(val
, 10, &max
);
1562 if (min
< 2 || min
>= max
|| max
> get_num_physpages())
1567 sfb_set_limits(min
, max
);
1568 pr_info("The sampling buffer limits have changed to: "
1569 "min=%lu max=%lu (diag=x%lu)\n",
1570 CPUM_SF_MIN_SDB
, CPUM_SF_MAX_SDB
, CPUM_SF_SDB_DIAG_FACTOR
);
1574 #define param_check_sfb_size(name, p) __param_check(name, p, void)
1575 static const struct kernel_param_ops param_ops_sfb_size
= {
1576 .set
= param_set_sfb_size
,
1577 .get
= param_get_sfb_size
,
1580 #define RS_INIT_FAILURE_QSI 0x0001
1581 #define RS_INIT_FAILURE_BSDES 0x0002
1582 #define RS_INIT_FAILURE_ALRT 0x0003
1583 #define RS_INIT_FAILURE_PERF 0x0004
1584 static void __init
pr_cpumsf_err(unsigned int reason
)
1586 pr_err("Sampling facility support for perf is not available: "
1587 "reason=%04x\n", reason
);
1590 static int __init
init_cpum_sampling_pmu(void)
1592 struct hws_qsi_info_block si
;
1595 if (!cpum_sf_avail())
1598 memset(&si
, 0, sizeof(si
));
1600 pr_cpumsf_err(RS_INIT_FAILURE_QSI
);
1604 if (si
.bsdes
!= sizeof(struct hws_basic_entry
)) {
1605 pr_cpumsf_err(RS_INIT_FAILURE_BSDES
);
1610 sfb_set_limits(CPUM_SF_MIN_SDB
, CPUM_SF_MAX_SDB
);
1611 cpumsf_pmu_events_attr
[1] =
1612 CPUMF_EVENT_PTR(SF
, SF_CYCLES_BASIC_DIAG
);
1615 sfdbg
= debug_register(KMSG_COMPONENT
, 2, 1, 80);
1617 pr_err("Registering for s390dbf failed\n");
1618 debug_register_view(sfdbg
, &debug_sprintf_view
);
1620 err
= register_external_irq(EXT_IRQ_MEASURE_ALERT
,
1621 cpumf_measurement_alert
);
1623 pr_cpumsf_err(RS_INIT_FAILURE_ALRT
);
1627 err
= perf_pmu_register(&cpumf_sampling
, "cpum_sf", PERF_TYPE_RAW
);
1629 pr_cpumsf_err(RS_INIT_FAILURE_PERF
);
1630 unregister_external_irq(EXT_IRQ_MEASURE_ALERT
,
1631 cpumf_measurement_alert
);
1634 perf_cpu_notifier(cpumf_pmu_notifier
);
1638 arch_initcall(init_cpum_sampling_pmu
);
1639 core_param(cpum_sfb_size
, CPUM_SF_MAX_SDB
, sfb_size
, 0640);