diff options
Diffstat (limited to 'powerpc/pmu/ebb/ebb.c')
| -rw-r--r-- | powerpc/pmu/ebb/ebb.c | 478 |
1 files changed, 478 insertions, 0 deletions
diff --git a/powerpc/pmu/ebb/ebb.c b/powerpc/pmu/ebb/ebb.c new file mode 100644 index 0000000..d7a72ce --- /dev/null +++ b/powerpc/pmu/ebb/ebb.c @@ -0,0 +1,478 @@ +/* + * Copyright 2014, Michael Ellerman, IBM Corp. + * Licensed under GPLv2. + */ + +#define _GNU_SOURCE /* For CPU_ZERO etc. */ + +#include <sched.h> +#include <sys/wait.h> +#include <setjmp.h> +#include <signal.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/ioctl.h> + +#include "trace.h" +#include "reg.h" +#include "ebb.h" + + +void (*ebb_user_func)(void); + +void ebb_hook(void) +{ + if (ebb_user_func) + ebb_user_func(); +} + +struct ebb_state ebb_state; + +u64 sample_period = 0x40000000ull; + +void reset_ebb_with_clear_mask(unsigned long mmcr0_clear_mask) +{ + u64 val; + + /* 2) clear MMCR0[PMAO] - docs say BESCR[PMEO] should do this */ + /* 3) set MMCR0[PMAE] - docs say BESCR[PME] should do this */ + val = mfspr(SPRN_MMCR0); + mtspr(SPRN_MMCR0, (val & ~mmcr0_clear_mask) | MMCR0_PMAE); + + /* 4) clear BESCR[PMEO] */ + mtspr(SPRN_BESCRR, BESCR_PMEO); + + /* 5) set BESCR[PME] */ + mtspr(SPRN_BESCRS, BESCR_PME); + + /* 6) rfebb 1 - done in our caller */ +} + +void reset_ebb(void) +{ + reset_ebb_with_clear_mask(MMCR0_PMAO | MMCR0_FC); +} + +/* Called outside of the EBB handler to check MMCR0 is sane */ +int ebb_check_mmcr0(void) +{ + u64 val; + + val = mfspr(SPRN_MMCR0); + if ((val & (MMCR0_FC | MMCR0_PMAO)) == MMCR0_FC) { + /* It's OK if we see FC & PMAO, but not FC by itself */ + printf("Outside of loop, only FC set 0x%llx\n", val); + return 1; + } + + return 0; +} + +bool ebb_check_count(int pmc, u64 sample_period, int fudge) +{ + u64 count, upper, lower; + + count = ebb_state.stats.pmc_count[PMC_INDEX(pmc)]; + + lower = ebb_state.stats.ebb_count * (sample_period - fudge); + + if (count < lower) { + printf("PMC%d count (0x%llx) below lower limit 0x%llx (-0x%llx)\n", + pmc, count, lower, lower - count); + return false; + } + + upper = ebb_state.stats.ebb_count * (sample_period + fudge); + + if (count > upper) { + printf("PMC%d count (0x%llx) above upper limit 0x%llx (+0x%llx)\n", + pmc, count, upper, count - upper); + return false; + } + + printf("PMC%d count (0x%llx) is between 0x%llx and 0x%llx delta +0x%llx/-0x%llx\n", + pmc, count, lower, upper, count - lower, upper - count); + + return true; +} + +void standard_ebb_callee(void) +{ + int found, i; + u64 val; + + val = mfspr(SPRN_BESCR); + if (!(val & BESCR_PMEO)) { + ebb_state.stats.spurious++; + goto out; + } + + ebb_state.stats.ebb_count++; + trace_log_counter(ebb_state.trace, ebb_state.stats.ebb_count); + + val = mfspr(SPRN_MMCR0); + trace_log_reg(ebb_state.trace, SPRN_MMCR0, val); + + found = 0; + for (i = 1; i <= 6; i++) { + if (ebb_state.pmc_enable[PMC_INDEX(i)]) + found += count_pmc(i, sample_period); + } + + if (!found) + ebb_state.stats.no_overflow++; + +out: + reset_ebb(); +} + +extern void ebb_handler(void); + +void setup_ebb_handler(void (*callee)(void)) +{ + u64 entry; + +#if defined(_CALL_ELF) && _CALL_ELF == 2 + entry = (u64)ebb_handler; +#else + struct opd + { + u64 entry; + u64 toc; + } *opd; + + opd = (struct opd *)ebb_handler; + entry = opd->entry; +#endif + printf("EBB Handler is at %#llx\n", entry); + + ebb_user_func = callee; + + /* Ensure ebb_user_func is set before we set the handler */ + mb(); + mtspr(SPRN_EBBHR, entry); + + /* Make sure the handler is set before we return */ + mb(); +} + +void clear_ebb_stats(void) +{ + memset(&ebb_state.stats, 0, sizeof(ebb_state.stats)); +} + +void dump_summary_ebb_state(void) +{ + printf("ebb_state:\n" \ + " ebb_count = %d\n" \ + " spurious = %d\n" \ + " negative = %d\n" \ + " no_overflow = %d\n" \ + " pmc[1] count = 0x%llx\n" \ + " pmc[2] count = 0x%llx\n" \ + " pmc[3] count = 0x%llx\n" \ + " pmc[4] count = 0x%llx\n" \ + " pmc[5] count = 0x%llx\n" \ + " pmc[6] count = 0x%llx\n", + ebb_state.stats.ebb_count, ebb_state.stats.spurious, + ebb_state.stats.negative, ebb_state.stats.no_overflow, + ebb_state.stats.pmc_count[0], ebb_state.stats.pmc_count[1], + ebb_state.stats.pmc_count[2], ebb_state.stats.pmc_count[3], + ebb_state.stats.pmc_count[4], ebb_state.stats.pmc_count[5]); +} + +static char *decode_mmcr0(u32 value) +{ + static char buf[16]; + + buf[0] = '\0'; + + if (value & (1 << 31)) + strcat(buf, "FC "); + if (value & (1 << 26)) + strcat(buf, "PMAE "); + if (value & (1 << 7)) + strcat(buf, "PMAO "); + + return buf; +} + +static char *decode_bescr(u64 value) +{ + static char buf[16]; + + buf[0] = '\0'; + + if (value & (1ull << 63)) + strcat(buf, "GE "); + if (value & (1ull << 32)) + strcat(buf, "PMAE "); + if (value & 1) + strcat(buf, "PMAO "); + + return buf; +} + +void dump_ebb_hw_state(void) +{ + u64 bescr; + u32 mmcr0; + + mmcr0 = mfspr(SPRN_MMCR0); + bescr = mfspr(SPRN_BESCR); + + printf("HW state:\n" \ + "MMCR0 0x%016x %s\n" \ + "MMCR2 0x%016lx\n" \ + "EBBHR 0x%016lx\n" \ + "BESCR 0x%016llx %s\n" \ + "PMC1 0x%016lx\n" \ + "PMC2 0x%016lx\n" \ + "PMC3 0x%016lx\n" \ + "PMC4 0x%016lx\n" \ + "PMC5 0x%016lx\n" \ + "PMC6 0x%016lx\n" \ + "SIAR 0x%016lx\n", + mmcr0, decode_mmcr0(mmcr0), mfspr(SPRN_MMCR2), + mfspr(SPRN_EBBHR), bescr, decode_bescr(bescr), + mfspr(SPRN_PMC1), mfspr(SPRN_PMC2), mfspr(SPRN_PMC3), + mfspr(SPRN_PMC4), mfspr(SPRN_PMC5), mfspr(SPRN_PMC6), + mfspr(SPRN_SIAR)); +} + +void dump_ebb_state(void) +{ + dump_summary_ebb_state(); + + dump_ebb_hw_state(); + + trace_buffer_print(ebb_state.trace); +} + +int count_pmc(int pmc, uint32_t sample_period) +{ + uint32_t start_value; + u64 val; + + /* 0) Read PMC */ + start_value = pmc_sample_period(sample_period); + + val = read_pmc(pmc); + if (val < start_value) + ebb_state.stats.negative++; + else + ebb_state.stats.pmc_count[PMC_INDEX(pmc)] += val - start_value; + + trace_log_reg(ebb_state.trace, SPRN_PMC1 + pmc - 1, val); + + /* 1) Reset PMC */ + write_pmc(pmc, start_value); + + /* Report if we overflowed */ + return val >= COUNTER_OVERFLOW; +} + +int ebb_event_enable(struct event *e) +{ + int rc; + + /* Ensure any SPR writes are ordered vs us */ + mb(); + + rc = ioctl(e->fd, PERF_EVENT_IOC_ENABLE); + if (rc) + return rc; + + rc = event_read(e); + + /* Ditto */ + mb(); + + return rc; +} + +void ebb_freeze_pmcs(void) +{ + mtspr(SPRN_MMCR0, mfspr(SPRN_MMCR0) | MMCR0_FC); + mb(); +} + +void ebb_unfreeze_pmcs(void) +{ + /* Unfreeze counters */ + mtspr(SPRN_MMCR0, mfspr(SPRN_MMCR0) & ~MMCR0_FC); + mb(); +} + +void ebb_global_enable(void) +{ + /* Enable EBBs globally and PMU EBBs */ + mtspr(SPRN_BESCR, 0x8000000100000000ull); + mb(); +} + +void ebb_global_disable(void) +{ + /* Disable EBBs & freeze counters, events are still scheduled */ + mtspr(SPRN_BESCRR, BESCR_PME); + mb(); +} + +void event_ebb_init(struct event *e) +{ + e->attr.config |= (1ull << 63); +} + +void event_bhrb_init(struct event *e, unsigned ifm) +{ + e->attr.config |= (1ull << 62) | ((u64)ifm << 60); +} + +void event_leader_ebb_init(struct event *e) +{ + event_ebb_init(e); + + e->attr.exclusive = 1; + e->attr.pinned = 1; +} + +int ebb_child(union pipe read_pipe, union pipe write_pipe) +{ + struct event event; + uint64_t val; + + FAIL_IF(wait_for_parent(read_pipe)); + + event_init_named(&event, 0x1001e, "cycles"); + event_leader_ebb_init(&event); + + event.attr.exclude_kernel = 1; + event.attr.exclude_hv = 1; + event.attr.exclude_idle = 1; + + FAIL_IF(event_open(&event)); + + ebb_enable_pmc_counting(1); + setup_ebb_handler(standard_ebb_callee); + ebb_global_enable(); + + FAIL_IF(event_enable(&event)); + + if (event_read(&event)) { + /* + * Some tests expect to fail here, so don't report an error on + * this line, and return a distinguisable error code. Tell the + * parent an error happened. + */ + notify_parent_of_error(write_pipe); + return 2; + } + + mtspr(SPRN_PMC1, pmc_sample_period(sample_period)); + + FAIL_IF(notify_parent(write_pipe)); + FAIL_IF(wait_for_parent(read_pipe)); + FAIL_IF(notify_parent(write_pipe)); + + while (ebb_state.stats.ebb_count < 20) { + FAIL_IF(core_busy_loop()); + + /* To try and hit SIGILL case */ + val = mfspr(SPRN_MMCRA); + val |= mfspr(SPRN_MMCR2); + val |= mfspr(SPRN_MMCR0); + } + + ebb_global_disable(); + ebb_freeze_pmcs(); + + count_pmc(1, sample_period); + + dump_ebb_state(); + + event_close(&event); + + FAIL_IF(ebb_state.stats.ebb_count == 0); + + return 0; +} + +static jmp_buf setjmp_env; + +static void sigill_handler(int signal) +{ + printf("Took sigill\n"); + longjmp(setjmp_env, 1); +} + +static struct sigaction sigill_action = { + .sa_handler = sigill_handler, +}; + +int catch_sigill(void (*func)(void)) +{ + if (sigaction(SIGILL, &sigill_action, NULL)) { + perror("sigaction"); + return 1; + } + + if (setjmp(setjmp_env) == 0) { + func(); + return 1; + } + + return 0; +} + +void write_pmc1(void) +{ + mtspr(SPRN_PMC1, 0); +} + +void write_pmc(int pmc, u64 value) +{ + switch (pmc) { + case 1: mtspr(SPRN_PMC1, value); break; + case 2: mtspr(SPRN_PMC2, value); break; + case 3: mtspr(SPRN_PMC3, value); break; + case 4: mtspr(SPRN_PMC4, value); break; + case 5: mtspr(SPRN_PMC5, value); break; + case 6: mtspr(SPRN_PMC6, value); break; + } +} + +u64 read_pmc(int pmc) +{ + switch (pmc) { + case 1: return mfspr(SPRN_PMC1); + case 2: return mfspr(SPRN_PMC2); + case 3: return mfspr(SPRN_PMC3); + case 4: return mfspr(SPRN_PMC4); + case 5: return mfspr(SPRN_PMC5); + case 6: return mfspr(SPRN_PMC6); + } + + return 0; +} + +static void term_handler(int signal) +{ + dump_summary_ebb_state(); + dump_ebb_hw_state(); + abort(); +} + +struct sigaction term_action = { + .sa_handler = term_handler, +}; + +static void __attribute__((constructor)) ebb_init(void) +{ + clear_ebb_stats(); + + if (sigaction(SIGTERM, &term_action, NULL)) + perror("sigaction"); + + ebb_state.trace = trace_buffer_allocate(1 * 1024 * 1024); +} |