static void
pctrrd(struct pctrst *st)
{
int i, num, reg;
num = pctr_isamd ? PCTR_AMD_NUM : PCTR_INTEL_NUM;
reg = pctr_isamd ? MSR_K7_EVNTSEL0 : MSR_EVNTSEL0;
for (i = 0; i < num; i++)
st->pctr_fn[i] = rdmsr(reg + i);
__asm volatile("cli");
st->pctr_tsc = rdtsc();
for (i = 0; i < num; i++)
st->pctr_hwc[i] = rdpmc(i);
__asm volatile("sti");
}
/* From Peter Zijlstra's demo code */
unsigned long long mmap_read_self(void *addr,
unsigned long long *enabled,
unsigned long long *running)
{
struct perf_event_mmap_page *pc = addr;
unsigned int seq;
unsigned long long count, delta=0, cyc;
unsigned long long rem, quot;
do {
again:
seq=pc->lock;
barrier();
if (seq&1) goto again;
if ((enabled || running) && pc->time_mult) {
cyc = rdtsc();
quot=(cyc >> pc->time_shift);
rem = cyc & ((1 << pc->time_shift) -1);
delta=pc->time_offset +
quot*pc->time_mult +
((rem * pc->time_mult) >> pc->time_shift);
}
if (enabled) *enabled=pc->time_enabled+delta;
if (running) *running=pc->time_running+delta;
if (pc->index) {
count=rdpmc(pc->index-1);
count+=pc->offset;
}
else goto fail;
barrier();
} while (pc->lock != seq);
inline uint64_t rdmpc64(uint32_t counter)
{
UInt32 lo,hi;
rdpmc(counter, lo, hi);
return ((UInt64)hi << 32 ) | lo;
}
