static void msr_event_start(struct perf_event *event, int flags)
{
u64 now;
now = msr_read_counter(event);
local64_set(&event->hw.prev_count, now);
}
static void msr_event_update(struct perf_event *event)
{
u64 prev, now;
s64 delta;
/* Careful, an NMI might modify the previous event value. */
again:
prev = local64_read(&event->hw.prev_count);
now = msr_read_counter(event);
if (local64_cmpxchg(&event->hw.prev_count, prev, now) != prev)
goto again;
delta = now - prev;
if (unlikely(event->hw.event_base == MSR_SMI_COUNT)) {
delta <<= 32;
delta >>= 32; /* sign extend */
}
static void msr_event_update(struct perf_event *event)
{
u64 prev, now;
s64 delta;
/* Careful, an NMI might modify the previous event value: */
again:
prev = local64_read(&event->hw.prev_count);
now = msr_read_counter(event);
if (local64_cmpxchg(&event->hw.prev_count, prev, now) != prev)
goto again;
delta = now - prev;
if (unlikely(event->hw.event_base == MSR_SMI_COUNT)) {
delta = sign_extend64(delta, 31);
local64_add(delta, &event->count);
} else if (unlikely(event->hw.event_base == MSR_IA32_THERM_STATUS)) {
/* If valid, extract digital readout, otherwise set to -1: */
now = now & (1ULL << 31) ? (now >> 16) & 0x3f : -1;
local64_set(&event->count, now);
} else {