143 	u64 now;  in msr_read_counter()  local
146 		rdmsrl(event->hw.event_base, now);  in msr_read_counter()
148 		rdtscll(now);  in msr_read_counter()
150 	return now;  in msr_read_counter()
154 	u64 prev, now;  in msr_event_update()  local
160 	now = msr_read_counter(event);  in msr_event_update()
162 	if (local64_cmpxchg(&event->hw.prev_count, prev, now) != prev)  in msr_event_update()
165 	delta = now - prev;  in msr_event_update()
169 	local64_add(now - prev, &event->count);  in msr_event_update()
174 	u64 now;  in msr_event_start()  local
176 	now = msr_read_counter(event);  in msr_event_start()
177 	local64_set(&event->hw.prev_count, now);  in msr_event_start()