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oprofile, s390: Add support for hardware based sampling on System z processors
[linux-2.6-block.git] / arch / s390 / oprofile / hwsampler.c
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ec6a3df1
HG		 1/**
2 * arch/s390/oprofile/hwsampler.c
3 *
4 * Copyright IBM Corp. 2010
5 * Author: Heinz Graalfs <graalfs@de.ibm.com>
6 */
7
8#include <linux/kernel.h>
9#include <linux/module.h>
10#include <linux/smp.h>
11#include <linux/errno.h>
12#include <linux/workqueue.h>
13#include <linux/interrupt.h>
14#include <linux/notifier.h>
15#include <linux/cpu.h>
16#include <linux/semaphore.h>
17#include <linux/oom.h>
18#include <linux/oprofile.h>
19
20#include <asm/lowcore.h>
21#include <asm/s390_ext.h>
22
23#include "hwsampler.h"
24
25#define MAX_NUM_SDB 511
26#define MIN_NUM_SDB 1
27
28#define ALERT_REQ_MASK 0x4000000000000000ul
29#define BUFFER_FULL_MASK 0x8000000000000000ul
30
31#define EI_IEA (1 << 31) /* invalid entry address */
32#define EI_ISE (1 << 30) /* incorrect SDBT entry */
33#define EI_PRA (1 << 29) /* program request alert */
34#define EI_SACA (1 << 23) /* sampler authorization change alert */
35#define EI_LSDA (1 << 22) /* loss of sample data alert */
36
37DECLARE_PER_CPU(struct hws_cpu_buffer, sampler_cpu_buffer);
38
39struct hws_execute_parms {
40 void *buffer;
41 signed int rc;
42};
43
44DEFINE_PER_CPU(struct hws_cpu_buffer, sampler_cpu_buffer);
45EXPORT_PER_CPU_SYMBOL(sampler_cpu_buffer);
46
47static DEFINE_MUTEX(hws_sem);
48static DEFINE_MUTEX(hws_sem_oom);
49
50static unsigned char hws_flush_all;
51static unsigned int hws_oom;
52static struct workqueue_struct *hws_wq;
53
54static unsigned int hws_state;
55enum {
56 HWS_INIT = 1,
57 HWS_DEALLOCATED,
58 HWS_STOPPED,
59 HWS_STARTED,
60 HWS_STOPPING };
61
62/* set to 1 if called by kernel during memory allocation */
63static unsigned char oom_killer_was_active;
64/* size of SDBT and SDB as of allocate API */
65static unsigned long num_sdbt = 100;
66static unsigned long num_sdb = 511;
67/* sampling interval (machine cycles) */
68static unsigned long interval;
69
70static unsigned long min_sampler_rate;
71static unsigned long max_sampler_rate;
72
73static int ssctl(void *buffer)
74{
75 int cc;
76
77 /* set in order to detect a program check */
78 cc = 1;
79
80 asm volatile(
81 "0: .insn s,0xB2870000,0(%1)\n"
82 "1: ipm %0\n"
83 " srl %0,28\n"
84 "2:\n"
85 EX_TABLE(0b, 2b) EX_TABLE(1b, 2b)
86 : "+d" (cc), "+a" (buffer)
87 : "m" (*((struct hws_ssctl_request_block *)buffer))
88 : "cc", "memory");
89
90 return cc ? -EINVAL : 0 ;
91}
92
93static int qsi(void *buffer)
94{
95 int cc;
96 cc = 1;
97
98 asm volatile(
99 "0: .insn s,0xB2860000,0(%1)\n"
100 "1: lhi %0,0\n"
101 "2:\n"
102 EX_TABLE(0b, 2b) EX_TABLE(1b, 2b)
103 : "=d" (cc), "+a" (buffer)
104 : "m" (*((struct hws_qsi_info_block *)buffer))
105 : "cc", "memory");
106
107 return cc ? -EINVAL : 0;
108}
109
110static void execute_qsi(void *parms)
111{
112 struct hws_execute_parms *ep = parms;
113
114 ep->rc = qsi(ep->buffer);
115}
116
117static void execute_ssctl(void *parms)
118{
119 struct hws_execute_parms *ep = parms;
120
121 ep->rc = ssctl(ep->buffer);
122}
123
124static int smp_ctl_ssctl_stop(int cpu)
125{
126 int rc;
127 struct hws_execute_parms ep;
128 struct hws_cpu_buffer *cb;
129
130 cb = &per_cpu(sampler_cpu_buffer, cpu);
131
132 cb->ssctl.es = 0;
133 cb->ssctl.cs = 0;
134
135 ep.buffer = &cb->ssctl;
136 smp_call_function_single(cpu, execute_ssctl, &ep, 1);
137 rc = ep.rc;
138 if (rc) {
139 printk(KERN_ERR "hwsampler: CPU %d CPUMF SSCTL failed.\n", cpu);
140 dump_stack();
141 }
142
143 ep.buffer = &cb->qsi;
144 smp_call_function_single(cpu, execute_qsi, &ep, 1);
145
146 if (cb->qsi.es || cb->qsi.cs) {
147 printk(KERN_EMERG "CPUMF sampling did not stop properly.\n");
148 dump_stack();
149 }
150
151 return rc;
152}
153
154static int smp_ctl_ssctl_deactivate(int cpu)
155{
156 int rc;
157 struct hws_execute_parms ep;
158 struct hws_cpu_buffer *cb;
159
160 cb = &per_cpu(sampler_cpu_buffer, cpu);
161
162 cb->ssctl.es = 1;
163 cb->ssctl.cs = 0;
164
165 ep.buffer = &cb->ssctl;
166 smp_call_function_single(cpu, execute_ssctl, &ep, 1);
167 rc = ep.rc;
168 if (rc)
169 printk(KERN_ERR "hwsampler: CPU %d CPUMF SSCTL failed.\n", cpu);
170
171 ep.buffer = &cb->qsi;
172 smp_call_function_single(cpu, execute_qsi, &ep, 1);
173
174 if (cb->qsi.cs)
175 printk(KERN_EMERG "CPUMF sampling was not set inactive.\n");
176
177 return rc;
178}
179
180static int smp_ctl_ssctl_enable_activate(int cpu, unsigned long interval)
181{
182 int rc;
183 struct hws_execute_parms ep;
184 struct hws_cpu_buffer *cb;
185
186 cb = &per_cpu(sampler_cpu_buffer, cpu);
187
188 cb->ssctl.h = 1;
189 cb->ssctl.tear = cb->first_sdbt;
190 cb->ssctl.dear = *(unsigned long *) cb->first_sdbt;
191 cb->ssctl.interval = interval;
192 cb->ssctl.es = 1;
193 cb->ssctl.cs = 1;
194
195 ep.buffer = &cb->ssctl;
196 smp_call_function_single(cpu, execute_ssctl, &ep, 1);
197 rc = ep.rc;
198 if (rc)
199 printk(KERN_ERR "hwsampler: CPU %d CPUMF SSCTL failed.\n", cpu);
200
201 ep.buffer = &cb->qsi;
202 smp_call_function_single(cpu, execute_qsi, &ep, 1);
203 if (ep.rc)
204 printk(KERN_ERR "hwsampler: CPU %d CPUMF QSI failed.\n", cpu);
205
206 return rc;
207}
208
209static int smp_ctl_qsi(int cpu)
210{
211 struct hws_execute_parms ep;
212 struct hws_cpu_buffer *cb;
213
214 cb = &per_cpu(sampler_cpu_buffer, cpu);
215
216 ep.buffer = &cb->qsi;
217 smp_call_function_single(cpu, execute_qsi, &ep, 1);
218
219 return ep.rc;
220}
221
222static inline unsigned long *trailer_entry_ptr(unsigned long v)
223{
224 void *ret;
225
226 ret = (void *)v;
227 ret += PAGE_SIZE;
228 ret -= sizeof(struct hws_trailer_entry);
229
230 return (unsigned long *) ret;
231}
232
233/* prototypes for external interrupt handler and worker */
234static void hws_ext_handler(unsigned int ext_int_code,
235 unsigned int param32, unsigned long param64);
236
237static void worker(struct work_struct *work);
238
239static void add_samples_to_oprofile(unsigned cpu, unsigned long *,
240 unsigned long *dear);
241
242static void init_all_cpu_buffers(void)
243{
244 int cpu;
245 struct hws_cpu_buffer *cb;
246
247 for_each_online_cpu(cpu) {
248 cb = &per_cpu(sampler_cpu_buffer, cpu);
249 memset(cb, 0, sizeof(struct hws_cpu_buffer));
250 }
251}
252
253static int is_link_entry(unsigned long *s)
254{
255 return *s & 0x1ul ? 1 : 0;
256}
257
258static unsigned long *get_next_sdbt(unsigned long *s)
259{
260 return (unsigned long *) (*s & ~0x1ul);
261}
262
263static int prepare_cpu_buffers(void)
264{
265 int cpu;
266 int rc;
267 struct hws_cpu_buffer *cb;
268
269 rc = 0;
270 for_each_online_cpu(cpu) {
271 cb = &per_cpu(sampler_cpu_buffer, cpu);
272 atomic_set(&cb->ext_params, 0);
273 cb->worker_entry = 0;
274 cb->sample_overflow = 0;
275 cb->req_alert = 0;
276 cb->incorrect_sdbt_entry = 0;
277 cb->invalid_entry_address = 0;
278 cb->loss_of_sample_data = 0;
279 cb->sample_auth_change_alert = 0;
280 cb->finish = 0;
281 cb->oom = 0;
282 cb->stop_mode = 0;
283 }
284
285 return rc;
286}
287
288/*
289 * allocate_sdbt() - allocate sampler memory
290 * @cpu: the cpu for which sampler memory is allocated
291 *
292 * A 4K page is allocated for each requested SDBT.
293 * A maximum of 511 4K pages are allocated for the SDBs in each of the SDBTs.
294 * Set ALERT_REQ mask in each SDBs trailer.
295 * Returns zero if successful, <0 otherwise.
296 */
297static int allocate_sdbt(int cpu)
298{
299 int j, k, rc;
300 unsigned long *sdbt;
301 unsigned long sdb;
302 unsigned long *tail;
303 unsigned long *trailer;
304 struct hws_cpu_buffer *cb;
305
306 cb = &per_cpu(sampler_cpu_buffer, cpu);
307
308 if (cb->first_sdbt)
309 return -EINVAL;
310
311 sdbt = NULL;
312 tail = sdbt;
313
314 for (j = 0; j < num_sdbt; j++) {
315 sdbt = (unsigned long *)get_zeroed_page(GFP_KERNEL);
316
317 mutex_lock(&hws_sem_oom);
318 /* OOM killer might have been activated */
319 barrier();
320 if (oom_killer_was_active || !sdbt) {
321 if (sdbt)
322 free_page((unsigned long)sdbt);
323
324 goto allocate_sdbt_error;
325 }
326 if (cb->first_sdbt == 0)
327 cb->first_sdbt = (unsigned long)sdbt;
328
329 /* link current page to tail of chain */
330 if (tail)
331 *tail = (unsigned long)(void *)sdbt + 1;
332
333 mutex_unlock(&hws_sem_oom);
334
335 for (k = 0; k < num_sdb; k++) {
336 /* get and set SDB page */
337 sdb = get_zeroed_page(GFP_KERNEL);
338
339 mutex_lock(&hws_sem_oom);
340 /* OOM killer might have been activated */
341 barrier();
342 if (oom_killer_was_active || !sdb) {
343 if (sdb)
344 free_page(sdb);
345
346 goto allocate_sdbt_error;
347 }
348 *sdbt = sdb;
349 trailer = trailer_entry_ptr(*sdbt);
350 *trailer = ALERT_REQ_MASK;
351 sdbt++;
352 mutex_unlock(&hws_sem_oom);
353 }
354 tail = sdbt;
355 }
356 mutex_lock(&hws_sem_oom);
357 if (oom_killer_was_active)
358 goto allocate_sdbt_error;
359
360 rc = 0;
361 if (tail)
362 *tail = (unsigned long)
363 ((void *)cb->first_sdbt) + 1;
364
365allocate_sdbt_exit:
366 mutex_unlock(&hws_sem_oom);
367 return rc;
368
369allocate_sdbt_error:
370 rc = -ENOMEM;
371 goto allocate_sdbt_exit;
372}
373
374/*
375 * deallocate_sdbt() - deallocate all sampler memory
376 *
377 * For each online CPU all SDBT trees are deallocated.
378 * Returns the number of freed pages.
379 */
380static int deallocate_sdbt(void)
381{
382 int cpu;
383 int counter;
384
385 counter = 0;
386
387 for_each_online_cpu(cpu) {
388 unsigned long start;
389 unsigned long sdbt;
390 unsigned long *curr;
391 struct hws_cpu_buffer *cb;
392
393 cb = &per_cpu(sampler_cpu_buffer, cpu);
394
395 if (!cb->first_sdbt)
396 continue;
397
398 sdbt = cb->first_sdbt;
399 curr = (unsigned long *) sdbt;
400 start = sdbt;
401
402 /* we'll free the SDBT after all SDBs are processed... */
403 while (1) {
404 if (!*curr || !sdbt)
405 break;
406
407 /* watch for link entry reset if found */
408 if (is_link_entry(curr)) {
409 curr = get_next_sdbt(curr);
410 if (sdbt)
411 free_page(sdbt);
412
413 /* we are done if we reach the start */
414 if ((unsigned long) curr == start)
415 break;
416 else
417 sdbt = (unsigned long) curr;
418 } else {
419 /* process SDB pointer */
420 if (*curr) {
421 free_page(*curr);
422 curr++;
423 }
424 }
425 counter++;
426 }
427 cb->first_sdbt = 0;
428 }
429 return counter;
430}
431
432static int start_sampling(int cpu)
433{
434 int rc;
435 struct hws_cpu_buffer *cb;
436
437 cb = &per_cpu(sampler_cpu_buffer, cpu);
438 rc = smp_ctl_ssctl_enable_activate(cpu, interval);
439 if (rc) {
440 printk(KERN_INFO "hwsampler: CPU %d ssctl failed.\n", cpu);
441 goto start_exit;
442 }
443
444 rc = -EINVAL;
445 if (!cb->qsi.es) {
446 printk(KERN_INFO "hwsampler: CPU %d ssctl not enabled.\n", cpu);
447 goto start_exit;
448 }
449
450 if (!cb->qsi.cs) {
451 printk(KERN_INFO "hwsampler: CPU %d ssctl not active.\n", cpu);
452 goto start_exit;
453 }
454
455 printk(KERN_INFO
456 "hwsampler: CPU %d, CPUMF Sampling started, interval %lu.\n",
457 cpu, interval);
458
459 rc = 0;
460
461start_exit:
462 return rc;
463}
464
465static int stop_sampling(int cpu)
466{
467 unsigned long v;
468 int rc;
469 struct hws_cpu_buffer *cb;
470
471 rc = smp_ctl_qsi(cpu);
472 WARN_ON(rc);
473
474 cb = &per_cpu(sampler_cpu_buffer, cpu);
475 if (!rc && !cb->qsi.es)
476 printk(KERN_INFO "hwsampler: CPU %d, already stopped.\n", cpu);
477
478 rc = smp_ctl_ssctl_stop(cpu);
479 if (rc) {
480 printk(KERN_INFO "hwsampler: CPU %d, ssctl stop error %d.\n",
481 cpu, rc);
482 goto stop_exit;
483 }
484
485 printk(KERN_INFO "hwsampler: CPU %d, CPUMF Sampling stopped.\n", cpu);
486
487stop_exit:
488 v = cb->req_alert;
489 if (v)
490 printk(KERN_ERR "hwsampler: CPU %d CPUMF Request alert,"
491 " count=%lu.\n", cpu, v);
492
493 v = cb->loss_of_sample_data;
494 if (v)
495 printk(KERN_ERR "hwsampler: CPU %d CPUMF Loss of sample data,"
496 " count=%lu.\n", cpu, v);
497
498 v = cb->invalid_entry_address;
499 if (v)
500 printk(KERN_ERR "hwsampler: CPU %d CPUMF Invalid entry address,"
501 " count=%lu.\n", cpu, v);
502
503 v = cb->incorrect_sdbt_entry;
504 if (v)
505 printk(KERN_ERR
506 "hwsampler: CPU %d CPUMF Incorrect SDBT address,"
507 " count=%lu.\n", cpu, v);
508
509 v = cb->sample_auth_change_alert;
510 if (v)
511 printk(KERN_ERR
512 "hwsampler: CPU %d CPUMF Sample authorization change,"
513 " count=%lu.\n", cpu, v);
514
515 return rc;
516}
517
518static int check_hardware_prerequisites(void)
519{
520 unsigned long long facility_bits[2];
521
522 memcpy(facility_bits, S390_lowcore.stfle_fac_list, 32);
523 if (!(facility_bits[1] & (1ULL << 59)))
524 return -EOPNOTSUPP;
525
526 return 0;
527}
528/*
529 * hws_oom_callback() - the OOM callback function
530 *
531 * In case the callback is invoked during memory allocation for the
532 * hw sampler, all obtained memory is deallocated and a flag is set
533 * so main sampler memory allocation can exit with a failure code.
534 * In case the callback is invoked during sampling the hw sampler
535 * is deactivated for all CPUs.
536 */
537static int hws_oom_callback(struct notifier_block *nfb,
538 unsigned long dummy, void *parm)
539{
540 unsigned long *freed;
541 int cpu;
542 struct hws_cpu_buffer *cb;
543
544 freed = parm;
545
546 mutex_lock(&hws_sem_oom);
547
548 if (hws_state == HWS_DEALLOCATED) {
549 /* during memory allocation */
550 if (oom_killer_was_active == 0) {
551 oom_killer_was_active = 1;
552 *freed += deallocate_sdbt();
553 }
554 } else {
555 int i;
556 cpu = get_cpu();
557 cb = &per_cpu(sampler_cpu_buffer, cpu);
558
559 if (!cb->oom) {
560 for_each_online_cpu(i) {
561 smp_ctl_ssctl_deactivate(i);
562 cb->oom = 1;
563 }
564 cb->finish = 1;
565
566 printk(KERN_INFO
567 "hwsampler: CPU %d, OOM notify during CPUMF Sampling.\n",
568 cpu);
569 }
570 }
571
572 mutex_unlock(&hws_sem_oom);
573
574 return NOTIFY_OK;
575}
576
577static struct notifier_block hws_oom_notifier = {
578 .notifier_call = hws_oom_callback
579};
580
581static int __cpuinit hws_cpu_callback(struct notifier_block *nfb,
582 unsigned long action, void *hcpu)
583{
584 /* We do not have sampler space available for all possible CPUs.
585 All CPUs should be online when hw sampling is activated. */
586 return NOTIFY_BAD;
587}
588
589static struct notifier_block hws_cpu_notifier = {
590 .notifier_call = hws_cpu_callback
591};
592
593/**
594 * hwsampler_deactivate() - set hardware sampling temporarily inactive
595 * @cpu: specifies the CPU to be set inactive.
596 *
597 * Returns 0 on success, !0 on failure.
598 */
599int hwsampler_deactivate(unsigned int cpu)
600{
601 /*
602 * Deactivate hw sampling temporarily and flush the buffer
603 * by pushing all the pending samples to oprofile buffer.
604 *
605 * This function can be called under one of the following conditions:
606 * Memory unmap, task is exiting.
607 */
608 int rc;
609 struct hws_cpu_buffer *cb;
610
611 rc = 0;
612 mutex_lock(&hws_sem);
613
614 cb = &per_cpu(sampler_cpu_buffer, cpu);
615 if (hws_state == HWS_STARTED) {
616 rc = smp_ctl_qsi(cpu);
617 WARN_ON(rc);
618 if (cb->qsi.cs) {
619 rc = smp_ctl_ssctl_deactivate(cpu);
620 if (rc) {
621 printk(KERN_INFO
622 "hwsampler: CPU %d, CPUMF Deactivation failed.\n", cpu);
623 cb->finish = 1;
624 hws_state = HWS_STOPPING;
625 } else {
626 hws_flush_all = 1;
627 /* Add work to queue to read pending samples.*/
628 queue_work_on(cpu, hws_wq, &cb->worker);
629 }
630 }
631 }
632 mutex_unlock(&hws_sem);
633
634 if (hws_wq)
635 flush_workqueue(hws_wq);
636
637 return rc;
638}
639
640/**
641 * hwsampler_activate() - activate/resume hardware sampling which was deactivated
642 * @cpu: specifies the CPU to be set active.
643 *
644 * Returns 0 on success, !0 on failure.
645 */
646int hwsampler_activate(unsigned int cpu)
647{
648 /*
649 * Re-activate hw sampling. This should be called in pair with
650 * hwsampler_deactivate().
651 */
652 int rc;
653 struct hws_cpu_buffer *cb;
654
655 rc = 0;
656 mutex_lock(&hws_sem);
657
658 cb = &per_cpu(sampler_cpu_buffer, cpu);
659 if (hws_state == HWS_STARTED) {
660 rc = smp_ctl_qsi(cpu);
661 WARN_ON(rc);
662 if (!cb->qsi.cs) {
663 hws_flush_all = 0;
664 rc = smp_ctl_ssctl_enable_activate(cpu, interval);
665 if (rc) {
666 printk(KERN_ERR
667 "CPU %d, CPUMF activate sampling failed.\n",
668 cpu);
669 }
670 }
671 }
672
673 mutex_unlock(&hws_sem);
674
675 return rc;
676}
677
678static void hws_ext_handler(unsigned int ext_int_code,
679 unsigned int param32, unsigned long param64)
680{
681 int cpu;
682 struct hws_cpu_buffer *cb;
683
684 cpu = smp_processor_id();
685 cb = &per_cpu(sampler_cpu_buffer, cpu);
686
687 atomic_xchg(
688 &cb->ext_params,
689 atomic_read(&cb->ext_params)
690 | S390_lowcore.ext_params);
691
692 if (hws_wq)
693 queue_work(hws_wq, &cb->worker);
694}
695
696static int check_qsi_on_setup(void)
697{
698 int rc;
699 unsigned int cpu;
700 struct hws_cpu_buffer *cb;
701
702 for_each_online_cpu(cpu) {
703 cb = &per_cpu(sampler_cpu_buffer, cpu);
704 rc = smp_ctl_qsi(cpu);
705 WARN_ON(rc);
706 if (rc)
707 return -EOPNOTSUPP;
708
709 if (!cb->qsi.as) {
710 printk(KERN_INFO "hwsampler: CPUMF sampling is not authorized.\n");
711 return -EINVAL;
712 }
713
714 if (cb->qsi.es) {
715 printk(KERN_WARNING "hwsampler: CPUMF is still enabled.\n");
716 rc = smp_ctl_ssctl_stop(cpu);
717 if (rc)
718 return -EINVAL;
719
720 printk(KERN_INFO
721 "CPU %d, CPUMF Sampling stopped now.\n", cpu);
722 }
723 }
724 return 0;
725}
726
727static int check_qsi_on_start(void)
728{
729 unsigned int cpu;
730 int rc;
731 struct hws_cpu_buffer *cb;
732
733 for_each_online_cpu(cpu) {
734 cb = &per_cpu(sampler_cpu_buffer, cpu);
735 rc = smp_ctl_qsi(cpu);
736 WARN_ON(rc);
737
738 if (!cb->qsi.as)
739 return -EINVAL;
740
741 if (cb->qsi.es)
742 return -EINVAL;
743
744 if (cb->qsi.cs)
745 return -EINVAL;
746 }
747 return 0;
748}
749
750static void worker_on_start(unsigned int cpu)
751{
752 struct hws_cpu_buffer *cb;
753
754 cb = &per_cpu(sampler_cpu_buffer, cpu);
755 cb->worker_entry = cb->first_sdbt;
756}
757
758static int worker_check_error(unsigned int cpu, int ext_params)
759{
760 int rc;
761 unsigned long *sdbt;
762 struct hws_cpu_buffer *cb;
763
764 rc = 0;
765 cb = &per_cpu(sampler_cpu_buffer, cpu);
766 sdbt = (unsigned long *) cb->worker_entry;
767
768 if (!sdbt || !*sdbt)
769 return -EINVAL;
770
771 if (ext_params & EI_IEA)
772 cb->req_alert++;
773
774 if (ext_params & EI_LSDA)
775 cb->loss_of_sample_data++;
776
777 if (ext_params & EI_IEA) {
778 cb->invalid_entry_address++;
779 rc = -EINVAL;
780 }
781
782 if (ext_params & EI_ISE) {
783 cb->incorrect_sdbt_entry++;
784 rc = -EINVAL;
785 }
786
787 if (ext_params & EI_SACA) {
788 cb->sample_auth_change_alert++;
789 rc = -EINVAL;
790 }
791
792 return rc;
793}
794
795static void worker_on_finish(unsigned int cpu)
796{
797 int rc, i;
798 struct hws_cpu_buffer *cb;
799
800 cb = &per_cpu(sampler_cpu_buffer, cpu);
801
802 if (cb->finish) {
803 rc = smp_ctl_qsi(cpu);
804 WARN_ON(rc);
805 if (cb->qsi.es) {
806 printk(KERN_INFO
807 "hwsampler: CPU %d, CPUMF Stop/Deactivate sampling.\n",
808 cpu);
809 rc = smp_ctl_ssctl_stop(cpu);
810 if (rc)
811 printk(KERN_INFO
812 "hwsampler: CPU %d, CPUMF Deactivation failed.\n",
813 cpu);
814
815 for_each_online_cpu(i) {
816 if (i == cpu)
817 continue;
818 if (!cb->finish) {
819 cb->finish = 1;
820 queue_work_on(i, hws_wq,
821 &cb->worker);
822 }
823 }
824 }
825 }
826}
827
828static void worker_on_interrupt(unsigned int cpu)
829{
830 unsigned long *sdbt;
831 unsigned char done;
832 struct hws_cpu_buffer *cb;
833
834 cb = &per_cpu(sampler_cpu_buffer, cpu);
835
836 sdbt = (unsigned long *) cb->worker_entry;
837
838 done = 0;
839 /* do not proceed if stop was entered,
840 * forget the buffers not yet processed */
841 while (!done && !cb->stop_mode) {
842 unsigned long *trailer;
843 struct hws_trailer_entry *te;
844 unsigned long *dear = 0;
845
846 trailer = trailer_entry_ptr(*sdbt);
847 /* leave loop if no more work to do */
848 if (!(*trailer & BUFFER_FULL_MASK)) {
849 done = 1;
850 if (!hws_flush_all)
851 continue;
852 }
853
854 te = (struct hws_trailer_entry *)trailer;
855 cb->sample_overflow += te->overflow;
856
857 add_samples_to_oprofile(cpu, sdbt, dear);
858
859 /* reset trailer */
860 xchg((unsigned char *) te, 0x40);
861
862 /* advance to next sdb slot in current sdbt */
863 sdbt++;
864 /* in case link bit is set use address w/o link bit */
865 if (is_link_entry(sdbt))
866 sdbt = get_next_sdbt(sdbt);
867
868 cb->worker_entry = (unsigned long)sdbt;
869 }
870}
871
872static void add_samples_to_oprofile(unsigned int cpu, unsigned long *sdbt,
873 unsigned long *dear)
874{
875 struct hws_data_entry *sample_data_ptr;
876 unsigned long *trailer;
877
878 trailer = trailer_entry_ptr(*sdbt);
879 if (dear) {
880 if (dear > trailer)
881 return;
882 trailer = dear;
883 }
884
885 sample_data_ptr = (struct hws_data_entry *)(*sdbt);
886
887 while ((unsigned long *)sample_data_ptr < trailer) {
888 struct pt_regs *regs = NULL;
889 struct task_struct *tsk = NULL;
890
891 /*
892 * Check sampling mode, 1 indicates basic (=customer) sampling
893 * mode.
894 */
895 if (sample_data_ptr->def != 1) {
896 /* sample slot is not yet written */
897 break;
898 } else {
899 /* make sure we don't use it twice,
900 * the next time the sampler will set it again */
901 sample_data_ptr->def = 0;
902 }
903
904 /* Get pt_regs. */
905 if (sample_data_ptr->P == 1) {
906 /* userspace sample */
907 unsigned int pid = sample_data_ptr->prim_asn;
908 rcu_read_lock();
909 tsk = pid_task(find_vpid(pid), PIDTYPE_PID);
910 if (tsk)
911 regs = task_pt_regs(tsk);
912 rcu_read_unlock();
913 } else {
914 /* kernelspace sample */
915 regs = task_pt_regs(current);
916 }
917
918 mutex_lock(&hws_sem);
919 oprofile_add_ext_hw_sample(sample_data_ptr->ia, regs, 0,
920 !sample_data_ptr->P, tsk);
921 mutex_unlock(&hws_sem);
922
923 sample_data_ptr++;
924 }
925}
926
927static void worker(struct work_struct *work)
928{
929 unsigned int cpu;
930 int ext_params;
931 struct hws_cpu_buffer *cb;
932
933 cb = container_of(work, struct hws_cpu_buffer, worker);
934 cpu = smp_processor_id();
935 ext_params = atomic_xchg(&cb->ext_params, 0);
936
937 if (!cb->worker_entry)
938 worker_on_start(cpu);
939
940 if (worker_check_error(cpu, ext_params))
941 return;
942
943 if (!cb->finish)
944 worker_on_interrupt(cpu);
945
946 if (cb->finish)
947 worker_on_finish(cpu);
948}
949
950/**
951 * hwsampler_allocate() - allocate memory for the hardware sampler
952 * @sdbt: number of SDBTs per online CPU (must be > 0)
953 * @sdb: number of SDBs per SDBT (minimum 1, maximum 511)
954 *
955 * Returns 0 on success, !0 on failure.
956 */
957int hwsampler_allocate(unsigned long sdbt, unsigned long sdb)
958{
959 int cpu, rc;
960 mutex_lock(&hws_sem);
961
962 rc = -EINVAL;
963 if (hws_state != HWS_DEALLOCATED)
964 goto allocate_exit;
965
966 if (sdbt < 1)
967 goto allocate_exit;
968
969 if (sdb > MAX_NUM_SDB || sdb < MIN_NUM_SDB)
970 goto allocate_exit;
971
972 num_sdbt = sdbt;
973 num_sdb = sdb;
974
975 oom_killer_was_active = 0;
976 register_oom_notifier(&hws_oom_notifier);
977
978 for_each_online_cpu(cpu) {
979 if (allocate_sdbt(cpu)) {
980 unregister_oom_notifier(&hws_oom_notifier);
981 goto allocate_error;
982 }
983 }
984 unregister_oom_notifier(&hws_oom_notifier);
985 if (oom_killer_was_active)
986 goto allocate_error;
987
988 hws_state = HWS_STOPPED;
989 rc = 0;
990
991allocate_exit:
992 mutex_unlock(&hws_sem);
993 return rc;
994
995allocate_error:
996 rc = -ENOMEM;
997 printk(KERN_ERR "hwsampler: CPUMF Memory allocation failed.\n");
998 goto allocate_exit;
999}
1000
1001/**
1002 * hwsampler_deallocate() - deallocate hardware sampler memory
1003 *
1004 * Returns 0 on success, !0 on failure.
1005 */
1006int hwsampler_deallocate()
1007{
1008 int rc;
1009
1010 mutex_lock(&hws_sem);
1011
1012 rc = -EINVAL;
1013 if (hws_state != HWS_STOPPED)
1014 goto deallocate_exit;
1015
1016 smp_ctl_clear_bit(0, 5); /* set bit 58 CR0 off */
1017 deallocate_sdbt();
1018
1019 hws_state = HWS_DEALLOCATED;
1020 rc = 0;
1021
1022deallocate_exit:
1023 mutex_unlock(&hws_sem);
1024
1025 return rc;
1026}
1027
1028long hwsampler_query_min_interval(void)
1029{
1030 if (min_sampler_rate)
1031 return min_sampler_rate;
1032 else
1033 return -EINVAL;
1034}
1035
1036long hwsampler_query_max_interval(void)
1037{
1038 if (max_sampler_rate)
1039 return max_sampler_rate;
1040 else
1041 return -EINVAL;
1042}
1043
1044unsigned long hwsampler_get_sample_overflow_count(unsigned int cpu)
1045{
1046 struct hws_cpu_buffer *cb;
1047
1048 cb = &per_cpu(sampler_cpu_buffer, cpu);
1049
1050 return cb->sample_overflow;
1051}
1052
1053int hwsampler_setup()
1054{
1055 int rc;
1056 int cpu;
1057 struct hws_cpu_buffer *cb;
1058
1059 mutex_lock(&hws_sem);
1060
1061 rc = -EINVAL;
1062 if (hws_state)
1063 goto setup_exit;
1064
1065 hws_state = HWS_INIT;
1066
1067 init_all_cpu_buffers();
1068
1069 rc = check_hardware_prerequisites();
1070 if (rc)
1071 goto setup_exit;
1072
1073 rc = check_qsi_on_setup();
1074 if (rc)
1075 goto setup_exit;
1076
1077 rc = -EINVAL;
1078 hws_wq = create_workqueue("hwsampler");
1079 if (!hws_wq)
1080 goto setup_exit;
1081
1082 register_cpu_notifier(&hws_cpu_notifier);
1083
1084 for_each_online_cpu(cpu) {
1085 cb = &per_cpu(sampler_cpu_buffer, cpu);
1086 INIT_WORK(&cb->worker, worker);
1087 rc = smp_ctl_qsi(cpu);
1088 WARN_ON(rc);
1089 if (min_sampler_rate != cb->qsi.min_sampl_rate) {
1090 if (min_sampler_rate) {
1091 printk(KERN_WARNING
1092 "hwsampler: different min sampler rate values.\n");
1093 if (min_sampler_rate < cb->qsi.min_sampl_rate)
1094 min_sampler_rate =
1095 cb->qsi.min_sampl_rate;
1096 } else
1097 min_sampler_rate = cb->qsi.min_sampl_rate;
1098 }
1099 if (max_sampler_rate != cb->qsi.max_sampl_rate) {
1100 if (max_sampler_rate) {
1101 printk(KERN_WARNING
1102 "hwsampler: different max sampler rate values.\n");
1103 if (max_sampler_rate > cb->qsi.max_sampl_rate)
1104 max_sampler_rate =
1105 cb->qsi.max_sampl_rate;
1106 } else
1107 max_sampler_rate = cb->qsi.max_sampl_rate;
1108 }
1109 }
1110 register_external_interrupt(0x1407, hws_ext_handler);
1111
1112 hws_state = HWS_DEALLOCATED;
1113 rc = 0;
1114
1115setup_exit:
1116 mutex_unlock(&hws_sem);
1117 return rc;
1118}
1119
1120int hwsampler_shutdown()
1121{
1122 int rc;
1123
1124 mutex_lock(&hws_sem);
1125
1126 rc = -EINVAL;
1127 if (hws_state == HWS_DEALLOCATED || hws_state == HWS_STOPPED) {
1128 mutex_unlock(&hws_sem);
1129
1130 if (hws_wq)
1131 flush_workqueue(hws_wq);
1132
1133 mutex_lock(&hws_sem);
1134
1135 if (hws_state == HWS_STOPPED) {
1136 smp_ctl_clear_bit(0, 5); /* set bit 58 CR0 off */
1137 deallocate_sdbt();
1138 }
1139 if (hws_wq) {
1140 destroy_workqueue(hws_wq);
1141 hws_wq = NULL;
1142 }
1143
1144 unregister_external_interrupt(0x1407, hws_ext_handler);
1145 hws_state = HWS_INIT;
1146 rc = 0;
1147 }
1148 mutex_unlock(&hws_sem);
1149
1150 unregister_cpu_notifier(&hws_cpu_notifier);
1151
1152 return rc;
1153}
1154
1155/**
1156 * hwsampler_start_all() - start hardware sampling on all online CPUs
1157 * @rate: specifies the used interval when samples are taken
1158 *
1159 * Returns 0 on success, !0 on failure.
1160 */
1161int hwsampler_start_all(unsigned long rate)
1162{
1163 int rc, cpu;
1164
1165 mutex_lock(&hws_sem);
1166
1167 hws_oom = 0;
1168
1169 rc = -EINVAL;
1170 if (hws_state != HWS_STOPPED)
1171 goto start_all_exit;
1172
1173 interval = rate;
1174
1175 /* fail if rate is not valid */
1176 if (interval < min_sampler_rate || interval > max_sampler_rate)
1177 goto start_all_exit;
1178
1179 rc = check_qsi_on_start();
1180 if (rc)
1181 goto start_all_exit;
1182
1183 rc = prepare_cpu_buffers();
1184 if (rc)
1185 goto start_all_exit;
1186
1187 for_each_online_cpu(cpu) {
1188 rc = start_sampling(cpu);
1189 if (rc)
1190 break;
1191 }
1192 if (rc) {
1193 for_each_online_cpu(cpu) {
1194 stop_sampling(cpu);
1195 }
1196 goto start_all_exit;
1197 }
1198 hws_state = HWS_STARTED;
1199 rc = 0;
1200
1201start_all_exit:
1202 mutex_unlock(&hws_sem);
1203
1204 if (rc)
1205 return rc;
1206
1207 register_oom_notifier(&hws_oom_notifier);
1208 hws_oom = 1;
1209 hws_flush_all = 0;
1210 /* now let them in, 1407 CPUMF external interrupts */
1211 smp_ctl_set_bit(0, 5); /* set CR0 bit 58 */
1212
1213 return 0;
1214}
1215
1216/**
1217 * hwsampler_stop_all() - stop hardware sampling on all online CPUs
1218 *
1219 * Returns 0 on success, !0 on failure.
1220 */
1221int hwsampler_stop_all()
1222{
1223 int tmp_rc, rc, cpu;
1224 struct hws_cpu_buffer *cb;
1225
1226 mutex_lock(&hws_sem);
1227
1228 rc = 0;
1229 if (hws_state == HWS_INIT) {
1230 mutex_unlock(&hws_sem);
1231 return rc;
1232 }
1233 hws_state = HWS_STOPPING;
1234 mutex_unlock(&hws_sem);
1235
1236 for_each_online_cpu(cpu) {
1237 cb = &per_cpu(sampler_cpu_buffer, cpu);
1238 cb->stop_mode = 1;
1239 tmp_rc = stop_sampling(cpu);
1240 if (tmp_rc)
1241 rc = tmp_rc;
1242 }
1243
1244 if (hws_wq)
1245 flush_workqueue(hws_wq);
1246
1247 mutex_lock(&hws_sem);
1248 if (hws_oom) {
1249 unregister_oom_notifier(&hws_oom_notifier);
1250 hws_oom = 0;
1251 }
1252 hws_state = HWS_STOPPED;
1253 mutex_unlock(&hws_sem);
1254
1255 return rc;
1256}
Linux 6.x block layer and io_uring tree(s)