// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright 2014, Michael Ellerman, IBM Corp.
*/
#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 "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();
}
bool ebb_is_supported(void)
{
#ifdef PPC_FEATURE2_EBB
/* EBB requires at least POWER8 */
return have_hwcap2(PPC_FEATURE2_EBB);
#else
return false;
#endif
}
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();
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);
}
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