231 	u64 now;  in msr_read_counter()  local
234 		rdmsrl(event->hw.event_base, now);  in msr_read_counter()
236 		now = rdtsc_ordered();  in msr_read_counter()
238 	return now;  in msr_read_counter()
243 	u64 prev, now;  in msr_event_update()  local
249 		now = msr_read_counter(event);  in msr_event_update()
250 	} while (!local64_try_cmpxchg(&event->hw.prev_count, &prev, now));  in msr_event_update()
252 	delta = now - prev;  in msr_event_update()
258 		now = now & (1ULL << 31) ? (now >> 16) & 0x3f :  -1;  in msr_event_update()
259 		local64_set(&event->count, now);  in msr_event_update()
267 	u64 now = msr_read_counter(event);  in msr_event_start()  local
269 	local64_set(&event->hw.prev_count, now);  in msr_event_start()