74 static inline void perf_mmap__write_tail(struct perf_mmap *md, u64 tail)  in perf_mmap__write_tail()  argument
76 	ring_buffer_write_tail(md->base, tail);  in perf_mmap__write_tail()
138 static int __perf_mmap__read_init(struct perf_mmap *md)  in __perf_mmap__read_init()  argument
140 	u64 head = perf_mmap__read_head(md);  in __perf_mmap__read_init()
141 	u64 old = md->prev;  in __perf_mmap__read_init()
142 	unsigned char *data = md->base + page_size;  in __perf_mmap__read_init()
145 	md->start = md->overwrite ? head : old;  in __perf_mmap__read_init()
146 	md->end = md->overwrite ? old : head;  in __perf_mmap__read_init()
148 	if ((md->end - md->start) < md->flush)  in __perf_mmap__read_init()
151 	size = md->end - md->start;  in __perf_mmap__read_init()
152 	if (size > (unsigned long)(md->mask) + 1) {  in __perf_mmap__read_init()
153 		if (!md->overwrite) {  in __perf_mmap__read_init()
156 			md->prev = head;  in __perf_mmap__read_init()
157 			perf_mmap__consume(md);  in __perf_mmap__read_init()
165 		if (overwrite_rb_find_range(data, md->mask, &md->start, &md->end))  in __perf_mmap__read_init()