/*
* We cannot restore the ibs pmu state, so we always needs to update
* the event while stopping it and then reset the state when starting
* again. Thus, ignoring PERF_EF_RELOAD and PERF_EF_UPDATE flags in
* perf_ibs_start()/perf_ibs_stop() and instead always do it.
*/
static void perf_ibs_start(struct perf_event *event, int flags)
{
struct hw_perf_event *hwc = &event->hw;
struct perf_ibs *perf_ibs = container_of(event->pmu, struct perf_ibs, pmu);
struct cpu_perf_ibs *pcpu = this_cpu_ptr(perf_ibs->pcpu);
u64 period;
if (WARN_ON_ONCE(!(hwc->state & PERF_HES_STOPPED)))
return;
WARN_ON_ONCE(!(hwc->state & PERF_HES_UPTODATE));
hwc->state = 0;
perf_ibs_set_period(perf_ibs, hwc, &period);
/*
* Set STARTED before enabling the hardware, such that
* a subsequent NMI must observe it. Then clear STOPPING
* such that we don't consume NMIs by accident.
*/
set_bit(IBS_STARTED, pcpu->state);
clear_bit(IBS_STOPPING, pcpu->state);
perf_ibs_enable_event(perf_ibs, hwc, period >> 4);
perf_event_update_userpage(event);
}
/*
* We cannot restore the ibs pmu state, so we always needs to update
* the event while stopping it and then reset the state when starting
* again. Thus, ignoring PERF_EF_RELOAD and PERF_EF_UPDATE flags in
* perf_ibs_start()/perf_ibs_stop() and instead always do it.
*/
static void perf_ibs_start(struct perf_event *event, int flags)
{
struct hw_perf_event *hwc = &event->hw;
struct perf_ibs *perf_ibs = container_of(event->pmu, struct perf_ibs, pmu);
struct cpu_perf_ibs *pcpu = this_cpu_ptr(perf_ibs->pcpu);
u64 period;
if (WARN_ON_ONCE(!(hwc->state & PERF_HES_STOPPED)))
return;
WARN_ON_ONCE(!(hwc->state & PERF_HES_UPTODATE));
hwc->state = 0;
perf_ibs_set_period(perf_ibs, hwc, &period);
set_bit(IBS_STARTED, pcpu->state);
perf_ibs_enable_event(perf_ibs, hwc, period >> 4);
perf_event_update_userpage(event);
}
static int perf_ibs_handle_irq(struct perf_ibs *perf_ibs, struct pt_regs *iregs)
{
struct cpu_perf_ibs *pcpu = this_cpu_ptr(perf_ibs->pcpu);
struct perf_event *event = pcpu->event;
struct hw_perf_event *hwc = &event->hw;
struct perf_sample_data data;
struct perf_raw_record raw;
struct pt_regs regs;
struct perf_ibs_data ibs_data;
int offset, size, check_rip, offset_max, throttle = 0;
unsigned int msr;
u64 *buf, *config, period;
if (!test_bit(IBS_STARTED, pcpu->state)) {
/*
* Catch spurious interrupts after stopping IBS: After
* disabling IBS there could be still incoming NMIs
* with samples that even have the valid bit cleared.
* Mark all this NMIs as handled.
*/
return test_and_clear_bit(IBS_STOPPING, pcpu->state) ? 1 : 0;
}
msr = hwc->config_base;
buf = ibs_data.regs;
rdmsrl(msr, *buf);
if (!(*buf++ & perf_ibs->valid_mask))
return 0;
config = &ibs_data.regs[0];
perf_ibs_event_update(perf_ibs, event, config);
perf_sample_data_init(&data, 0, hwc->last_period);
if (!perf_ibs_set_period(perf_ibs, hwc, &period))
goto out; /* no sw counter overflow */
ibs_data.caps = ibs_caps;
size = 1;
offset = 1;
check_rip = (perf_ibs == &perf_ibs_op && (ibs_caps & IBS_CAPS_RIPINVALIDCHK));
if (event->attr.sample_type & PERF_SAMPLE_RAW)
offset_max = perf_ibs->offset_max;
else if (check_rip)
offset_max = 2;
else
offset_max = 1;
do {
rdmsrl(msr + offset, *buf++);
size++;
offset = find_next_bit(perf_ibs->offset_mask,
perf_ibs->offset_max,
offset + 1);
} while (offset < offset_max);
if (event->attr.sample_type & PERF_SAMPLE_RAW) {
/*
* Read IbsBrTarget and IbsOpData4 separately
* depending on their availability.
* Can't add to offset_max as they are staggered
*/
if (ibs_caps & IBS_CAPS_BRNTRGT) {
rdmsrl(MSR_AMD64_IBSBRTARGET, *buf++);
size++;
}
if (ibs_caps & IBS_CAPS_OPDATA4) {
rdmsrl(MSR_AMD64_IBSOPDATA4, *buf++);
size++;
}
}
ibs_data.size = sizeof(u64) * size;
regs = *iregs;
if (check_rip && (ibs_data.regs[2] & IBS_RIP_INVALID)) {
regs.flags &= ~PERF_EFLAGS_EXACT;
} else {
set_linear_ip(®s, ibs_data.regs[1]);
regs.flags |= PERF_EFLAGS_EXACT;
}
if (event->attr.sample_type & PERF_SAMPLE_RAW) {
raw.size = sizeof(u32) + ibs_data.size;
raw.data = ibs_data.data;
data.raw = &raw;
}
throttle = perf_event_overflow(event, &data, ®s);
out:
if (throttle)
perf_ibs_disable_event(perf_ibs, hwc, *config);
else
perf_ibs_enable_event(perf_ibs, hwc, period >> 4);
perf_event_update_userpage(event);
return 1;
}