2 * Copyright 2014, Michael Ellerman, IBM Corp.
3 * Licensed under GPLv2.
6 #define _GNU_SOURCE /* For CPU_ZERO etc. */
15 #include <sys/ioctl.h>
21 void (*ebb_user_func)(void);
29 struct ebb_state ebb_state;
31 u64 sample_period = 0x40000000ull;
33 void reset_ebb_with_clear_mask(unsigned long mmcr0_clear_mask)
37 /* 2) clear MMCR0[PMAO] - docs say BESCR[PMEO] should do this */
38 /* 3) set MMCR0[PMAE] - docs say BESCR[PME] should do this */
39 val = mfspr(SPRN_MMCR0);
40 mtspr(SPRN_MMCR0, (val & ~mmcr0_clear_mask) | MMCR0_PMAE);
42 /* 4) clear BESCR[PMEO] */
43 mtspr(SPRN_BESCRR, BESCR_PMEO);
45 /* 5) set BESCR[PME] */
46 mtspr(SPRN_BESCRS, BESCR_PME);
48 /* 6) rfebb 1 - done in our caller */
53 reset_ebb_with_clear_mask(MMCR0_PMAO | MMCR0_FC);
56 /* Called outside of the EBB handler to check MMCR0 is sane */
57 int ebb_check_mmcr0(void)
61 val = mfspr(SPRN_MMCR0);
62 if ((val & (MMCR0_FC | MMCR0_PMAO)) == MMCR0_FC) {
63 /* It's OK if we see FC & PMAO, but not FC by itself */
64 printf("Outside of loop, only FC set 0x%llx\n", val);
71 bool ebb_check_count(int pmc, u64 sample_period, int fudge)
73 u64 count, upper, lower;
75 count = ebb_state.stats.pmc_count[PMC_INDEX(pmc)];
77 lower = ebb_state.stats.ebb_count * (sample_period - fudge);
80 printf("PMC%d count (0x%llx) below lower limit 0x%llx (-0x%llx)\n",
81 pmc, count, lower, lower - count);
85 upper = ebb_state.stats.ebb_count * (sample_period + fudge);
88 printf("PMC%d count (0x%llx) above upper limit 0x%llx (+0x%llx)\n",
89 pmc, count, upper, count - upper);
93 printf("PMC%d count (0x%llx) is between 0x%llx and 0x%llx delta +0x%llx/-0x%llx\n",
94 pmc, count, lower, upper, count - lower, upper - count);
99 void standard_ebb_callee(void)
104 val = mfspr(SPRN_BESCR);
105 if (!(val & BESCR_PMEO)) {
106 ebb_state.stats.spurious++;
110 ebb_state.stats.ebb_count++;
111 trace_log_counter(ebb_state.trace, ebb_state.stats.ebb_count);
113 val = mfspr(SPRN_MMCR0);
114 trace_log_reg(ebb_state.trace, SPRN_MMCR0, val);
117 for (i = 1; i <= 6; i++) {
118 if (ebb_state.pmc_enable[PMC_INDEX(i)])
119 found += count_pmc(i, sample_period);
123 ebb_state.stats.no_overflow++;
129 extern void ebb_handler(void);
131 void setup_ebb_handler(void (*callee)(void))
135 #if defined(_CALL_ELF) && _CALL_ELF == 2
136 entry = (u64)ebb_handler;
144 opd = (struct opd *)ebb_handler;
147 printf("EBB Handler is at %#llx\n", entry);
149 ebb_user_func = callee;
151 /* Ensure ebb_user_func is set before we set the handler */
153 mtspr(SPRN_EBBHR, entry);
155 /* Make sure the handler is set before we return */
159 void clear_ebb_stats(void)
161 memset(&ebb_state.stats, 0, sizeof(ebb_state.stats));
164 void dump_summary_ebb_state(void)
166 printf("ebb_state:\n" \
167 " ebb_count = %d\n" \
170 " no_overflow = %d\n" \
171 " pmc[1] count = 0x%llx\n" \
172 " pmc[2] count = 0x%llx\n" \
173 " pmc[3] count = 0x%llx\n" \
174 " pmc[4] count = 0x%llx\n" \
175 " pmc[5] count = 0x%llx\n" \
176 " pmc[6] count = 0x%llx\n",
177 ebb_state.stats.ebb_count, ebb_state.stats.spurious,
178 ebb_state.stats.negative, ebb_state.stats.no_overflow,
179 ebb_state.stats.pmc_count[0], ebb_state.stats.pmc_count[1],
180 ebb_state.stats.pmc_count[2], ebb_state.stats.pmc_count[3],
181 ebb_state.stats.pmc_count[4], ebb_state.stats.pmc_count[5]);
184 static char *decode_mmcr0(u32 value)
190 if (value & (1 << 31))
192 if (value & (1 << 26))
193 strcat(buf, "PMAE ");
194 if (value & (1 << 7))
195 strcat(buf, "PMAO ");
200 static char *decode_bescr(u64 value)
206 if (value & (1ull << 63))
208 if (value & (1ull << 32))
209 strcat(buf, "PMAE ");
211 strcat(buf, "PMAO ");
216 void dump_ebb_hw_state(void)
221 mmcr0 = mfspr(SPRN_MMCR0);
222 bescr = mfspr(SPRN_BESCR);
224 printf("HW state:\n" \
225 "MMCR0 0x%016x %s\n" \
228 "BESCR 0x%016llx %s\n" \
236 mmcr0, decode_mmcr0(mmcr0), mfspr(SPRN_MMCR2),
237 mfspr(SPRN_EBBHR), bescr, decode_bescr(bescr),
238 mfspr(SPRN_PMC1), mfspr(SPRN_PMC2), mfspr(SPRN_PMC3),
239 mfspr(SPRN_PMC4), mfspr(SPRN_PMC5), mfspr(SPRN_PMC6),
243 void dump_ebb_state(void)
245 dump_summary_ebb_state();
249 trace_buffer_print(ebb_state.trace);
252 int count_pmc(int pmc, uint32_t sample_period)
254 uint32_t start_value;
258 start_value = pmc_sample_period(sample_period);
261 if (val < start_value)
262 ebb_state.stats.negative++;
264 ebb_state.stats.pmc_count[PMC_INDEX(pmc)] += val - start_value;
266 trace_log_reg(ebb_state.trace, SPRN_PMC1 + pmc - 1, val);
269 write_pmc(pmc, start_value);
271 /* Report if we overflowed */
272 return val >= COUNTER_OVERFLOW;
275 int ebb_event_enable(struct event *e)
279 /* Ensure any SPR writes are ordered vs us */
282 rc = ioctl(e->fd, PERF_EVENT_IOC_ENABLE);
294 void ebb_freeze_pmcs(void)
296 mtspr(SPRN_MMCR0, mfspr(SPRN_MMCR0) | MMCR0_FC);
300 void ebb_unfreeze_pmcs(void)
302 /* Unfreeze counters */
303 mtspr(SPRN_MMCR0, mfspr(SPRN_MMCR0) & ~MMCR0_FC);
307 void ebb_global_enable(void)
309 /* Enable EBBs globally and PMU EBBs */
310 mtspr(SPRN_BESCR, 0x8000000100000000ull);
314 void ebb_global_disable(void)
316 /* Disable EBBs & freeze counters, events are still scheduled */
317 mtspr(SPRN_BESCRR, BESCR_PME);
321 bool ebb_is_supported(void)
323 #ifdef PPC_FEATURE2_EBB
324 /* EBB requires at least POWER8 */
325 return have_hwcap2(PPC_FEATURE2_EBB);
331 void event_ebb_init(struct event *e)
333 e->attr.config |= (1ull << 63);
336 void event_bhrb_init(struct event *e, unsigned ifm)
338 e->attr.config |= (1ull << 62) | ((u64)ifm << 60);
341 void event_leader_ebb_init(struct event *e)
345 e->attr.exclusive = 1;
349 int ebb_child(union pipe read_pipe, union pipe write_pipe)
354 FAIL_IF(wait_for_parent(read_pipe));
356 event_init_named(&event, 0x1001e, "cycles");
357 event_leader_ebb_init(&event);
359 event.attr.exclude_kernel = 1;
360 event.attr.exclude_hv = 1;
361 event.attr.exclude_idle = 1;
363 FAIL_IF(event_open(&event));
365 ebb_enable_pmc_counting(1);
366 setup_ebb_handler(standard_ebb_callee);
369 FAIL_IF(event_enable(&event));
371 if (event_read(&event)) {
373 * Some tests expect to fail here, so don't report an error on
374 * this line, and return a distinguisable error code. Tell the
375 * parent an error happened.
377 notify_parent_of_error(write_pipe);
381 mtspr(SPRN_PMC1, pmc_sample_period(sample_period));
383 FAIL_IF(notify_parent(write_pipe));
384 FAIL_IF(wait_for_parent(read_pipe));
385 FAIL_IF(notify_parent(write_pipe));
387 while (ebb_state.stats.ebb_count < 20) {
388 FAIL_IF(core_busy_loop());
390 /* To try and hit SIGILL case */
391 val = mfspr(SPRN_MMCRA);
392 val |= mfspr(SPRN_MMCR2);
393 val |= mfspr(SPRN_MMCR0);
396 ebb_global_disable();
399 count_pmc(1, sample_period);
405 FAIL_IF(ebb_state.stats.ebb_count == 0);
410 static jmp_buf setjmp_env;
412 static void sigill_handler(int signal)
414 printf("Took sigill\n");
415 longjmp(setjmp_env, 1);
418 static struct sigaction sigill_action = {
419 .sa_handler = sigill_handler,
422 int catch_sigill(void (*func)(void))
424 if (sigaction(SIGILL, &sigill_action, NULL)) {
429 if (setjmp(setjmp_env) == 0) {
437 void write_pmc1(void)
442 void write_pmc(int pmc, u64 value)
445 case 1: mtspr(SPRN_PMC1, value); break;
446 case 2: mtspr(SPRN_PMC2, value); break;
447 case 3: mtspr(SPRN_PMC3, value); break;
448 case 4: mtspr(SPRN_PMC4, value); break;
449 case 5: mtspr(SPRN_PMC5, value); break;
450 case 6: mtspr(SPRN_PMC6, value); break;
454 u64 read_pmc(int pmc)
457 case 1: return mfspr(SPRN_PMC1);
458 case 2: return mfspr(SPRN_PMC2);
459 case 3: return mfspr(SPRN_PMC3);
460 case 4: return mfspr(SPRN_PMC4);
461 case 5: return mfspr(SPRN_PMC5);
462 case 6: return mfspr(SPRN_PMC6);
468 static void term_handler(int signal)
470 dump_summary_ebb_state();
475 struct sigaction term_action = {
476 .sa_handler = term_handler,
479 static void __attribute__((constructor)) ebb_init(void)
483 if (sigaction(SIGTERM, &term_action, NULL))
486 ebb_state.trace = trace_buffer_allocate(1 * 1024 * 1024);