2 * arch/s390/oprofile/hwsampler.c
4 * Copyright IBM Corp. 2010
5 * Author: Heinz Graalfs <graalfs@de.ibm.com>
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>
20 #include <asm/lowcore.h>
21 #include <asm/s390_ext.h>
23 #include "hwsampler.h"
25 #define MAX_NUM_SDB 511
28 #define ALERT_REQ_MASK 0x4000000000000000ul
29 #define BUFFER_FULL_MASK 0x8000000000000000ul
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 */
37 DECLARE_PER_CPU(struct hws_cpu_buffer
, sampler_cpu_buffer
);
39 struct hws_execute_parms
{
44 DEFINE_PER_CPU(struct hws_cpu_buffer
, sampler_cpu_buffer
);
45 EXPORT_PER_CPU_SYMBOL(sampler_cpu_buffer
);
47 static DEFINE_MUTEX(hws_sem
);
48 static DEFINE_MUTEX(hws_sem_oom
);
50 static unsigned char hws_flush_all
;
51 static unsigned int hws_oom
;
52 static struct workqueue_struct
*hws_wq
;
54 static unsigned int hws_state
;
62 /* set to 1 if called by kernel during memory allocation */
63 static unsigned char oom_killer_was_active
;
64 /* size of SDBT and SDB as of allocate API */
65 static unsigned long num_sdbt
= 100;
66 static unsigned long num_sdb
= 511;
67 /* sampling interval (machine cycles) */
68 static unsigned long interval
;
70 static unsigned long min_sampler_rate
;
71 static unsigned long max_sampler_rate
;
73 static int ssctl(void *buffer
)
77 /* set in order to detect a program check */
81 "0: .insn s,0xB2870000,0(%1)\n"
85 EX_TABLE(0b
, 2b
) EX_TABLE(1b
, 2b
)
86 : "+d" (cc
), "+a" (buffer
)
87 : "m" (*((struct hws_ssctl_request_block
*)buffer
))
90 return cc
? -EINVAL
: 0 ;
93 static int qsi(void *buffer
)
99 "0: .insn s,0xB2860000,0(%1)\n"
102 EX_TABLE(0b
, 2b
) EX_TABLE(1b
, 2b
)
103 : "=d" (cc
), "+a" (buffer
)
104 : "m" (*((struct hws_qsi_info_block
*)buffer
))
107 return cc
? -EINVAL
: 0;
110 static void execute_qsi(void *parms
)
112 struct hws_execute_parms
*ep
= parms
;
114 ep
->rc
= qsi(ep
->buffer
);
117 static void execute_ssctl(void *parms
)
119 struct hws_execute_parms
*ep
= parms
;
121 ep
->rc
= ssctl(ep
->buffer
);
124 static int smp_ctl_ssctl_stop(int cpu
)
127 struct hws_execute_parms ep
;
128 struct hws_cpu_buffer
*cb
;
130 cb
= &per_cpu(sampler_cpu_buffer
, cpu
);
135 ep
.buffer
= &cb
->ssctl
;
136 smp_call_function_single(cpu
, execute_ssctl
, &ep
, 1);
139 printk(KERN_ERR
"hwsampler: CPU %d CPUMF SSCTL failed.\n", cpu
);
143 ep
.buffer
= &cb
->qsi
;
144 smp_call_function_single(cpu
, execute_qsi
, &ep
, 1);
146 if (cb
->qsi
.es
|| cb
->qsi
.cs
) {
147 printk(KERN_EMERG
"CPUMF sampling did not stop properly.\n");
154 static int smp_ctl_ssctl_deactivate(int cpu
)
157 struct hws_execute_parms ep
;
158 struct hws_cpu_buffer
*cb
;
160 cb
= &per_cpu(sampler_cpu_buffer
, cpu
);
165 ep
.buffer
= &cb
->ssctl
;
166 smp_call_function_single(cpu
, execute_ssctl
, &ep
, 1);
169 printk(KERN_ERR
"hwsampler: CPU %d CPUMF SSCTL failed.\n", cpu
);
171 ep
.buffer
= &cb
->qsi
;
172 smp_call_function_single(cpu
, execute_qsi
, &ep
, 1);
175 printk(KERN_EMERG
"CPUMF sampling was not set inactive.\n");
180 static int smp_ctl_ssctl_enable_activate(int cpu
, unsigned long interval
)
183 struct hws_execute_parms ep
;
184 struct hws_cpu_buffer
*cb
;
186 cb
= &per_cpu(sampler_cpu_buffer
, cpu
);
189 cb
->ssctl
.tear
= cb
->first_sdbt
;
190 cb
->ssctl
.dear
= *(unsigned long *) cb
->first_sdbt
;
191 cb
->ssctl
.interval
= interval
;
195 ep
.buffer
= &cb
->ssctl
;
196 smp_call_function_single(cpu
, execute_ssctl
, &ep
, 1);
199 printk(KERN_ERR
"hwsampler: CPU %d CPUMF SSCTL failed.\n", cpu
);
201 ep
.buffer
= &cb
->qsi
;
202 smp_call_function_single(cpu
, execute_qsi
, &ep
, 1);
204 printk(KERN_ERR
"hwsampler: CPU %d CPUMF QSI failed.\n", cpu
);
209 static int smp_ctl_qsi(int cpu
)
211 struct hws_execute_parms ep
;
212 struct hws_cpu_buffer
*cb
;
214 cb
= &per_cpu(sampler_cpu_buffer
, cpu
);
216 ep
.buffer
= &cb
->qsi
;
217 smp_call_function_single(cpu
, execute_qsi
, &ep
, 1);
222 static inline unsigned long *trailer_entry_ptr(unsigned long v
)
228 ret
-= sizeof(struct hws_trailer_entry
);
230 return (unsigned long *) ret
;
233 /* prototypes for external interrupt handler and worker */
234 static void hws_ext_handler(unsigned int ext_int_code
,
235 unsigned int param32
, unsigned long param64
);
237 static void worker(struct work_struct
*work
);
239 static void add_samples_to_oprofile(unsigned cpu
, unsigned long *,
240 unsigned long *dear
);
242 static void init_all_cpu_buffers(void)
245 struct hws_cpu_buffer
*cb
;
247 for_each_online_cpu(cpu
) {
248 cb
= &per_cpu(sampler_cpu_buffer
, cpu
);
249 memset(cb
, 0, sizeof(struct hws_cpu_buffer
));
253 static int is_link_entry(unsigned long *s
)
255 return *s
& 0x1ul
? 1 : 0;
258 static unsigned long *get_next_sdbt(unsigned long *s
)
260 return (unsigned long *) (*s
& ~0x1ul
);
263 static int prepare_cpu_buffers(void)
267 struct hws_cpu_buffer
*cb
;
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;
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;
289 * allocate_sdbt() - allocate sampler memory
290 * @cpu: the cpu for which sampler memory is allocated
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.
297 static int allocate_sdbt(int cpu
)
303 unsigned long *trailer
;
304 struct hws_cpu_buffer
*cb
;
306 cb
= &per_cpu(sampler_cpu_buffer
, cpu
);
314 for (j
= 0; j
< num_sdbt
; j
++) {
315 sdbt
= (unsigned long *)get_zeroed_page(GFP_KERNEL
);
317 mutex_lock(&hws_sem_oom
);
318 /* OOM killer might have been activated */
320 if (oom_killer_was_active
|| !sdbt
) {
322 free_page((unsigned long)sdbt
);
324 goto allocate_sdbt_error
;
326 if (cb
->first_sdbt
== 0)
327 cb
->first_sdbt
= (unsigned long)sdbt
;
329 /* link current page to tail of chain */
331 *tail
= (unsigned long)(void *)sdbt
+ 1;
333 mutex_unlock(&hws_sem_oom
);
335 for (k
= 0; k
< num_sdb
; k
++) {
336 /* get and set SDB page */
337 sdb
= get_zeroed_page(GFP_KERNEL
);
339 mutex_lock(&hws_sem_oom
);
340 /* OOM killer might have been activated */
342 if (oom_killer_was_active
|| !sdb
) {
346 goto allocate_sdbt_error
;
349 trailer
= trailer_entry_ptr(*sdbt
);
350 *trailer
= ALERT_REQ_MASK
;
352 mutex_unlock(&hws_sem_oom
);
356 mutex_lock(&hws_sem_oom
);
357 if (oom_killer_was_active
)
358 goto allocate_sdbt_error
;
362 *tail
= (unsigned long)
363 ((void *)cb
->first_sdbt
) + 1;
366 mutex_unlock(&hws_sem_oom
);
371 goto allocate_sdbt_exit
;
375 * deallocate_sdbt() - deallocate all sampler memory
377 * For each online CPU all SDBT trees are deallocated.
378 * Returns the number of freed pages.
380 static int deallocate_sdbt(void)
387 for_each_online_cpu(cpu
) {
391 struct hws_cpu_buffer
*cb
;
393 cb
= &per_cpu(sampler_cpu_buffer
, cpu
);
398 sdbt
= cb
->first_sdbt
;
399 curr
= (unsigned long *) sdbt
;
402 /* we'll free the SDBT after all SDBs are processed... */
407 /* watch for link entry reset if found */
408 if (is_link_entry(curr
)) {
409 curr
= get_next_sdbt(curr
);
413 /* we are done if we reach the start */
414 if ((unsigned long) curr
== start
)
417 sdbt
= (unsigned long) curr
;
419 /* process SDB pointer */
432 static int start_sampling(int cpu
)
435 struct hws_cpu_buffer
*cb
;
437 cb
= &per_cpu(sampler_cpu_buffer
, cpu
);
438 rc
= smp_ctl_ssctl_enable_activate(cpu
, interval
);
440 printk(KERN_INFO
"hwsampler: CPU %d ssctl failed.\n", cpu
);
446 printk(KERN_INFO
"hwsampler: CPU %d ssctl not enabled.\n", cpu
);
451 printk(KERN_INFO
"hwsampler: CPU %d ssctl not active.\n", cpu
);
456 "hwsampler: CPU %d, CPUMF Sampling started, interval %lu.\n",
465 static int stop_sampling(int cpu
)
469 struct hws_cpu_buffer
*cb
;
471 rc
= smp_ctl_qsi(cpu
);
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
);
478 rc
= smp_ctl_ssctl_stop(cpu
);
480 printk(KERN_INFO
"hwsampler: CPU %d, ssctl stop error %d.\n",
485 printk(KERN_INFO
"hwsampler: CPU %d, CPUMF Sampling stopped.\n", cpu
);
490 printk(KERN_ERR
"hwsampler: CPU %d CPUMF Request alert,"
491 " count=%lu.\n", cpu
, v
);
493 v
= cb
->loss_of_sample_data
;
495 printk(KERN_ERR
"hwsampler: CPU %d CPUMF Loss of sample data,"
496 " count=%lu.\n", cpu
, v
);
498 v
= cb
->invalid_entry_address
;
500 printk(KERN_ERR
"hwsampler: CPU %d CPUMF Invalid entry address,"
501 " count=%lu.\n", cpu
, v
);
503 v
= cb
->incorrect_sdbt_entry
;
506 "hwsampler: CPU %d CPUMF Incorrect SDBT address,"
507 " count=%lu.\n", cpu
, v
);
509 v
= cb
->sample_auth_change_alert
;
512 "hwsampler: CPU %d CPUMF Sample authorization change,"
513 " count=%lu.\n", cpu
, v
);
518 static int check_hardware_prerequisites(void)
520 unsigned long long facility_bits
[2];
522 memcpy(facility_bits
, S390_lowcore
.stfle_fac_list
, 32);
523 if (!(facility_bits
[1] & (1ULL << 59)))
529 * hws_oom_callback() - the OOM callback function
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.
537 static int hws_oom_callback(struct notifier_block
*nfb
,
538 unsigned long dummy
, void *parm
)
540 unsigned long *freed
;
542 struct hws_cpu_buffer
*cb
;
546 mutex_lock(&hws_sem_oom
);
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();
557 cb
= &per_cpu(sampler_cpu_buffer
, cpu
);
560 for_each_online_cpu(i
) {
561 smp_ctl_ssctl_deactivate(i
);
567 "hwsampler: CPU %d, OOM notify during CPUMF Sampling.\n",
572 mutex_unlock(&hws_sem_oom
);
577 static struct notifier_block hws_oom_notifier
= {
578 .notifier_call
= hws_oom_callback
581 static int hws_cpu_callback(struct notifier_block
*nfb
,
582 unsigned long action
, void *hcpu
)
584 /* We do not have sampler space available for all possible CPUs.
585 All CPUs should be online when hw sampling is activated. */
589 static struct notifier_block hws_cpu_notifier
= {
590 .notifier_call
= hws_cpu_callback
594 * hwsampler_deactivate() - set hardware sampling temporarily inactive
595 * @cpu: specifies the CPU to be set inactive.
597 * Returns 0 on success, !0 on failure.
599 int hwsampler_deactivate(unsigned int cpu
)
602 * Deactivate hw sampling temporarily and flush the buffer
603 * by pushing all the pending samples to oprofile buffer.
605 * This function can be called under one of the following conditions:
606 * Memory unmap, task is exiting.
609 struct hws_cpu_buffer
*cb
;
612 mutex_lock(&hws_sem
);
614 cb
= &per_cpu(sampler_cpu_buffer
, cpu
);
615 if (hws_state
== HWS_STARTED
) {
616 rc
= smp_ctl_qsi(cpu
);
619 rc
= smp_ctl_ssctl_deactivate(cpu
);
622 "hwsampler: CPU %d, CPUMF Deactivation failed.\n", cpu
);
624 hws_state
= HWS_STOPPING
;
627 /* Add work to queue to read pending samples.*/
628 queue_work_on(cpu
, hws_wq
, &cb
->worker
);
632 mutex_unlock(&hws_sem
);
635 flush_workqueue(hws_wq
);
641 * hwsampler_activate() - activate/resume hardware sampling which was deactivated
642 * @cpu: specifies the CPU to be set active.
644 * Returns 0 on success, !0 on failure.
646 int hwsampler_activate(unsigned int cpu
)
649 * Re-activate hw sampling. This should be called in pair with
650 * hwsampler_deactivate().
653 struct hws_cpu_buffer
*cb
;
656 mutex_lock(&hws_sem
);
658 cb
= &per_cpu(sampler_cpu_buffer
, cpu
);
659 if (hws_state
== HWS_STARTED
) {
660 rc
= smp_ctl_qsi(cpu
);
664 rc
= smp_ctl_ssctl_enable_activate(cpu
, interval
);
667 "CPU %d, CPUMF activate sampling failed.\n",
673 mutex_unlock(&hws_sem
);
678 static void hws_ext_handler(unsigned int ext_int_code
,
679 unsigned int param32
, unsigned long param64
)
682 struct hws_cpu_buffer
*cb
;
684 cpu
= smp_processor_id();
685 cb
= &per_cpu(sampler_cpu_buffer
, cpu
);
689 atomic_read(&cb
->ext_params
)
690 | S390_lowcore
.ext_params
);
693 queue_work(hws_wq
, &cb
->worker
);
696 static int check_qsi_on_setup(void)
700 struct hws_cpu_buffer
*cb
;
702 for_each_online_cpu(cpu
) {
703 cb
= &per_cpu(sampler_cpu_buffer
, cpu
);
704 rc
= smp_ctl_qsi(cpu
);
710 printk(KERN_INFO
"hwsampler: CPUMF sampling is not authorized.\n");
715 printk(KERN_WARNING
"hwsampler: CPUMF is still enabled.\n");
716 rc
= smp_ctl_ssctl_stop(cpu
);
721 "CPU %d, CPUMF Sampling stopped now.\n", cpu
);
727 static int check_qsi_on_start(void)
731 struct hws_cpu_buffer
*cb
;
733 for_each_online_cpu(cpu
) {
734 cb
= &per_cpu(sampler_cpu_buffer
, cpu
);
735 rc
= smp_ctl_qsi(cpu
);
750 static void worker_on_start(unsigned int cpu
)
752 struct hws_cpu_buffer
*cb
;
754 cb
= &per_cpu(sampler_cpu_buffer
, cpu
);
755 cb
->worker_entry
= cb
->first_sdbt
;
758 static int worker_check_error(unsigned int cpu
, int ext_params
)
762 struct hws_cpu_buffer
*cb
;
765 cb
= &per_cpu(sampler_cpu_buffer
, cpu
);
766 sdbt
= (unsigned long *) cb
->worker_entry
;
771 if (ext_params
& EI_IEA
)
774 if (ext_params
& EI_LSDA
)
775 cb
->loss_of_sample_data
++;
777 if (ext_params
& EI_IEA
) {
778 cb
->invalid_entry_address
++;
782 if (ext_params
& EI_ISE
) {
783 cb
->incorrect_sdbt_entry
++;
787 if (ext_params
& EI_SACA
) {
788 cb
->sample_auth_change_alert
++;
795 static void worker_on_finish(unsigned int cpu
)
798 struct hws_cpu_buffer
*cb
;
800 cb
= &per_cpu(sampler_cpu_buffer
, cpu
);
803 rc
= smp_ctl_qsi(cpu
);
807 "hwsampler: CPU %d, CPUMF Stop/Deactivate sampling.\n",
809 rc
= smp_ctl_ssctl_stop(cpu
);
812 "hwsampler: CPU %d, CPUMF Deactivation failed.\n",
815 for_each_online_cpu(i
) {
820 queue_work_on(i
, hws_wq
,
828 static void worker_on_interrupt(unsigned int cpu
)
832 struct hws_cpu_buffer
*cb
;
834 cb
= &per_cpu(sampler_cpu_buffer
, cpu
);
836 sdbt
= (unsigned long *) cb
->worker_entry
;
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;
846 trailer
= trailer_entry_ptr(*sdbt
);
847 /* leave loop if no more work to do */
848 if (!(*trailer
& BUFFER_FULL_MASK
)) {
854 te
= (struct hws_trailer_entry
*)trailer
;
855 cb
->sample_overflow
+= te
->overflow
;
857 add_samples_to_oprofile(cpu
, sdbt
, dear
);
860 xchg((unsigned char *) te
, 0x40);
862 /* advance to next sdb slot in current 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
);
868 cb
->worker_entry
= (unsigned long)sdbt
;
872 static void add_samples_to_oprofile(unsigned int cpu
, unsigned long *sdbt
,
875 struct hws_data_entry
*sample_data_ptr
;
876 unsigned long *trailer
;
878 trailer
= trailer_entry_ptr(*sdbt
);
885 sample_data_ptr
= (struct hws_data_entry
*)(*sdbt
);
887 while ((unsigned long *)sample_data_ptr
< trailer
) {
888 struct pt_regs
*regs
= NULL
;
889 struct task_struct
*tsk
= NULL
;
892 * Check sampling mode, 1 indicates basic (=customer) sampling
895 if (sample_data_ptr
->def
!= 1) {
896 /* sample slot is not yet written */
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;
905 if (sample_data_ptr
->P
== 1) {
906 /* userspace sample */
907 unsigned int pid
= sample_data_ptr
->prim_asn
;
909 tsk
= pid_task(find_vpid(pid
), PIDTYPE_PID
);
911 regs
= task_pt_regs(tsk
);
914 /* kernelspace sample */
915 regs
= task_pt_regs(current
);
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
);
927 static void worker(struct work_struct
*work
)
931 struct hws_cpu_buffer
*cb
;
933 cb
= container_of(work
, struct hws_cpu_buffer
, worker
);
934 cpu
= smp_processor_id();
935 ext_params
= atomic_xchg(&cb
->ext_params
, 0);
937 if (!cb
->worker_entry
)
938 worker_on_start(cpu
);
940 if (worker_check_error(cpu
, ext_params
))
944 worker_on_interrupt(cpu
);
947 worker_on_finish(cpu
);
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)
955 * Returns 0 on success, !0 on failure.
957 int hwsampler_allocate(unsigned long sdbt
, unsigned long sdb
)
960 mutex_lock(&hws_sem
);
963 if (hws_state
!= HWS_DEALLOCATED
)
969 if (sdb
> MAX_NUM_SDB
|| sdb
< MIN_NUM_SDB
)
975 oom_killer_was_active
= 0;
976 register_oom_notifier(&hws_oom_notifier
);
978 for_each_online_cpu(cpu
) {
979 if (allocate_sdbt(cpu
)) {
980 unregister_oom_notifier(&hws_oom_notifier
);
984 unregister_oom_notifier(&hws_oom_notifier
);
985 if (oom_killer_was_active
)
988 hws_state
= HWS_STOPPED
;
992 mutex_unlock(&hws_sem
);
997 printk(KERN_ERR
"hwsampler: CPUMF Memory allocation failed.\n");
1002 * hwsampler_deallocate() - deallocate hardware sampler memory
1004 * Returns 0 on success, !0 on failure.
1006 int hwsampler_deallocate()
1010 mutex_lock(&hws_sem
);
1013 if (hws_state
!= HWS_STOPPED
)
1014 goto deallocate_exit
;
1016 smp_ctl_clear_bit(0, 5); /* set bit 58 CR0 off */
1019 hws_state
= HWS_DEALLOCATED
;
1023 mutex_unlock(&hws_sem
);
1028 long hwsampler_query_min_interval(void)
1030 if (min_sampler_rate
)
1031 return min_sampler_rate
;
1036 long hwsampler_query_max_interval(void)
1038 if (max_sampler_rate
)
1039 return max_sampler_rate
;
1044 unsigned long hwsampler_get_sample_overflow_count(unsigned int cpu
)
1046 struct hws_cpu_buffer
*cb
;
1048 cb
= &per_cpu(sampler_cpu_buffer
, cpu
);
1050 return cb
->sample_overflow
;
1053 int hwsampler_setup()
1057 struct hws_cpu_buffer
*cb
;
1059 mutex_lock(&hws_sem
);
1065 hws_state
= HWS_INIT
;
1067 init_all_cpu_buffers();
1069 rc
= check_hardware_prerequisites();
1073 rc
= check_qsi_on_setup();
1078 hws_wq
= create_workqueue("hwsampler");
1082 register_cpu_notifier(&hws_cpu_notifier
);
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
);
1089 if (min_sampler_rate
!= cb
->qsi
.min_sampl_rate
) {
1090 if (min_sampler_rate
) {
1092 "hwsampler: different min sampler rate values.\n");
1093 if (min_sampler_rate
< cb
->qsi
.min_sampl_rate
)
1095 cb
->qsi
.min_sampl_rate
;
1097 min_sampler_rate
= cb
->qsi
.min_sampl_rate
;
1099 if (max_sampler_rate
!= cb
->qsi
.max_sampl_rate
) {
1100 if (max_sampler_rate
) {
1102 "hwsampler: different max sampler rate values.\n");
1103 if (max_sampler_rate
> cb
->qsi
.max_sampl_rate
)
1105 cb
->qsi
.max_sampl_rate
;
1107 max_sampler_rate
= cb
->qsi
.max_sampl_rate
;
1110 register_external_interrupt(0x1407, hws_ext_handler
);
1112 hws_state
= HWS_DEALLOCATED
;
1116 mutex_unlock(&hws_sem
);
1120 int hwsampler_shutdown()
1124 mutex_lock(&hws_sem
);
1127 if (hws_state
== HWS_DEALLOCATED
|| hws_state
== HWS_STOPPED
) {
1128 mutex_unlock(&hws_sem
);
1131 flush_workqueue(hws_wq
);
1133 mutex_lock(&hws_sem
);
1135 if (hws_state
== HWS_STOPPED
) {
1136 smp_ctl_clear_bit(0, 5); /* set bit 58 CR0 off */
1140 destroy_workqueue(hws_wq
);
1144 unregister_external_interrupt(0x1407, hws_ext_handler
);
1145 hws_state
= HWS_INIT
;
1148 mutex_unlock(&hws_sem
);
1150 unregister_cpu_notifier(&hws_cpu_notifier
);
1156 * hwsampler_start_all() - start hardware sampling on all online CPUs
1157 * @rate: specifies the used interval when samples are taken
1159 * Returns 0 on success, !0 on failure.
1161 int hwsampler_start_all(unsigned long rate
)
1165 mutex_lock(&hws_sem
);
1170 if (hws_state
!= HWS_STOPPED
)
1171 goto start_all_exit
;
1175 /* fail if rate is not valid */
1176 if (interval
< min_sampler_rate
|| interval
> max_sampler_rate
)
1177 goto start_all_exit
;
1179 rc
= check_qsi_on_start();
1181 goto start_all_exit
;
1183 rc
= prepare_cpu_buffers();
1185 goto start_all_exit
;
1187 for_each_online_cpu(cpu
) {
1188 rc
= start_sampling(cpu
);
1193 for_each_online_cpu(cpu
) {
1196 goto start_all_exit
;
1198 hws_state
= HWS_STARTED
;
1202 mutex_unlock(&hws_sem
);
1207 register_oom_notifier(&hws_oom_notifier
);
1210 /* now let them in, 1407 CPUMF external interrupts */
1211 smp_ctl_set_bit(0, 5); /* set CR0 bit 58 */
1217 * hwsampler_stop_all() - stop hardware sampling on all online CPUs
1219 * Returns 0 on success, !0 on failure.
1221 int hwsampler_stop_all()
1223 int tmp_rc
, rc
, cpu
;
1224 struct hws_cpu_buffer
*cb
;
1226 mutex_lock(&hws_sem
);
1229 if (hws_state
== HWS_INIT
) {
1230 mutex_unlock(&hws_sem
);
1233 hws_state
= HWS_STOPPING
;
1234 mutex_unlock(&hws_sem
);
1236 for_each_online_cpu(cpu
) {
1237 cb
= &per_cpu(sampler_cpu_buffer
, cpu
);
1239 tmp_rc
= stop_sampling(cpu
);
1245 flush_workqueue(hws_wq
);
1247 mutex_lock(&hws_sem
);
1249 unregister_oom_notifier(&hws_oom_notifier
);
1252 hws_state
= HWS_STOPPED
;
1253 mutex_unlock(&hws_sem
);