1 // SPDX-License-Identifier: GPL-2.0
19 void perf_mmap__init(struct perf_mmap *map, struct perf_mmap *prev,  in perf_mmap__init()  argument
23 	map->fd = -1;  in perf_mmap__init()
24 	map->overwrite = overwrite;  in perf_mmap__init()
25 	map->unmap_cb  = unmap_cb;  in perf_mmap__init()
26 	refcount_set(&map->refcnt, 0);  in perf_mmap__init()
28 		prev->next = map;  in perf_mmap__init()
31 size_t perf_mmap__mmap_len(struct perf_mmap *map)  in perf_mmap__mmap_len()  argument
33 	return map->mask + 1 + page_size;  in perf_mmap__mmap_len()
36 int perf_mmap__mmap(struct perf_mmap *map, struct perf_mmap_param *mp,  in perf_mmap__mmap()  argument
37 		    int fd, struct perf_cpu cpu)  in perf_mmap__mmap()
39 	map->prev = 0;  in perf_mmap__mmap()
40 	map->mask = mp->mask;  in perf_mmap__mmap()
41 	map->base = mmap(NULL, perf_mmap__mmap_len(map), mp->prot,  in perf_mmap__mmap()
43 	if (map->base == MAP_FAILED) {  in perf_mmap__mmap()
44 		map->base = NULL;  in perf_mmap__mmap()
45 		return -1;  in perf_mmap__mmap()
48 	map->fd  = fd;  in perf_mmap__mmap()
49 	map->cpu = cpu;  in perf_mmap__mmap()
53 void perf_mmap__munmap(struct perf_mmap *map)  in perf_mmap__munmap()  argument
55 	if (!map)  in perf_mmap__munmap()
58 	zfree(&map->event_copy);  in perf_mmap__munmap()
59 	map->event_copy_sz = 0;  in perf_mmap__munmap()
60 	if (map->base) {  in perf_mmap__munmap()
61 		munmap(map->base, perf_mmap__mmap_len(map));  in perf_mmap__munmap()
62 		map->base = NULL;  in perf_mmap__munmap()
63 		map->fd = -1;  in perf_mmap__munmap()
64 		refcount_set(&map->refcnt, 0);  in perf_mmap__munmap()
66 	if (map->unmap_cb)  in perf_mmap__munmap()
67 		map->unmap_cb(map);  in perf_mmap__munmap()
70 void perf_mmap__get(struct perf_mmap *map)  in perf_mmap__get()  argument
72 	refcount_inc(&map->refcnt);  in perf_mmap__get()
75 void perf_mmap__put(struct perf_mmap *map)  in perf_mmap__put()  argument
77 	BUG_ON(map->base && refcount_read(&map->refcnt) == 0);  in perf_mmap__put()
79 	if (refcount_dec_and_test(&map->refcnt))  in perf_mmap__put()
80 		perf_mmap__munmap(map);  in perf_mmap__put()
85 	ring_buffer_write_tail(md->base, tail);  in perf_mmap__write_tail()
88 u64 perf_mmap__read_head(struct perf_mmap *map)  in perf_mmap__read_head()  argument
90 	return ring_buffer_read_head(map->base);  in perf_mmap__read_head()
93 static bool perf_mmap__empty(struct perf_mmap *map)  in perf_mmap__empty()  argument
95 	struct perf_event_mmap_page *pc = map->base;  in perf_mmap__empty()
97 	return perf_mmap__read_head(map) == map->prev && !pc->aux_size;  in perf_mmap__empty()
100 void perf_mmap__consume(struct perf_mmap *map)  in perf_mmap__consume()  argument
102 	if (!map->overwrite) {  in perf_mmap__consume()
103 		u64 old = map->prev;  in perf_mmap__consume()
105 		perf_mmap__write_tail(map, old);  in perf_mmap__consume()
108 	if (refcount_read(&map->refcnt) == 1 && perf_mmap__empty(map))  in perf_mmap__consume()
109 		perf_mmap__put(map);  in perf_mmap__consume()
112 static int overwrite_rb_find_range(void *buf, int mask, u64 *start, u64 *end)  in overwrite_rb_find_range()  argument
116 	int size = mask + 1;  in overwrite_rb_find_range()
119 	pheader = (struct perf_event_header *)(buf + (*start & mask));  in overwrite_rb_find_range()
121 		if (evt_head - *start >= (unsigned int)size) {  in overwrite_rb_find_range()
123 			if (evt_head - *start > (unsigned int)size)  in overwrite_rb_find_range()
124 				evt_head -= pheader->size;  in overwrite_rb_find_range()
129 		pheader = (struct perf_event_header *)(buf + (evt_head & mask));  in overwrite_rb_find_range()
131 		if (pheader->size == 0) {  in overwrite_rb_find_range()
137 		evt_head += pheader->size;  in overwrite_rb_find_range()
141 	return -1;  in overwrite_rb_find_range()
147 static int __perf_mmap__read_init(struct perf_mmap *md)  in __perf_mmap__read_init()
150 	u64 old = md->prev;  in __perf_mmap__read_init()
151 	unsigned char *data = md->base + page_size;  in __perf_mmap__read_init()
154 	md->start = md->overwrite ? head : old;  in __perf_mmap__read_init()
155 	md->end = md->overwrite ? old : head;  in __perf_mmap__read_init()
157 	if ((md->end - md->start) < md->flush)  in __perf_mmap__read_init()
158 		return -EAGAIN;  in __perf_mmap__read_init()
160 	size = md->end - md->start;  in __perf_mmap__read_init()
161 	if (size > (unsigned long)(md->mask) + 1) {  in __perf_mmap__read_init()
162 		if (!md->overwrite) {  in __perf_mmap__read_init()
165 			md->prev = head;  in __perf_mmap__read_init()
167 			return -EAGAIN;  in __perf_mmap__read_init()
174 		if (overwrite_rb_find_range(data, md->mask, &md->start, &md->end))  in __perf_mmap__read_init()
175 			return -EINVAL;  in __perf_mmap__read_init()
181 int perf_mmap__read_init(struct perf_mmap *map)  in perf_mmap__read_init()  argument
186 	if (!refcount_read(&map->refcnt))  in perf_mmap__read_init()
187 		return -ENOENT;  in perf_mmap__read_init()
189 	return __perf_mmap__read_init(map);  in perf_mmap__read_init()
195  * The last perf_mmap__read() will set tail to map->core.prev.
196  * Need to correct the map->core.prev to head which is the end of next read.
198 void perf_mmap__read_done(struct perf_mmap *map)  in perf_mmap__read_done()  argument
203 	if (!refcount_read(&map->refcnt))  in perf_mmap__read_done()
206 	map->prev = perf_mmap__read_head(map);  in perf_mmap__read_done()
210 static union perf_event *perf_mmap__read(struct perf_mmap *map,  in perf_mmap__read()  argument
213 	unsigned char *data = map->base + page_size;  in perf_mmap__read()
215 	int diff = end - *startp;  in perf_mmap__read()
217 	if (diff >= (int)sizeof(event->header)) {  in perf_mmap__read()
220 		event = (union perf_event *)&data[*startp & map->mask];  in perf_mmap__read()
221 		size = event->header.size;  in perf_mmap__read()
223 		if (size < sizeof(event->header) || diff < (int)size)  in perf_mmap__read()
227 		 * Event straddles the mmap boundary -- header should always  in perf_mmap__read()
230 		if ((*startp & map->mask) + size != ((*startp + size) & map->mask)) {  in perf_mmap__read()
231 			unsigned int offset = *startp;  in perf_mmap__read()
232 			unsigned int len = size, cpy;  in perf_mmap__read()
233 			void *dst = map->event_copy;  in perf_mmap__read()
235 			if (size > map->event_copy_sz) {  in perf_mmap__read()
236 				dst = realloc(map->event_copy, size);  in perf_mmap__read()
239 				map->event_copy = dst;  in perf_mmap__read()
240 				map->event_copy_sz = size;  in perf_mmap__read()
244 				cpy = min(map->mask + 1 - (offset & map->mask), len);  in perf_mmap__read()
245 				memcpy(dst, &data[offset & map->mask], cpy);  in perf_mmap__read()
248 				len -= cpy;  in perf_mmap__read()
251 			event = (union perf_event *)map->event_copy;  in perf_mmap__read()
272 union perf_event *perf_mmap__read_event(struct perf_mmap *map)  in perf_mmap__read_event()  argument
279 	if (!refcount_read(&map->refcnt))  in perf_mmap__read_event()
282 	/* non-overwrite doesn't pause the ringbuffer */  in perf_mmap__read_event()
283 	if (!map->overwrite)  in perf_mmap__read_event()
284 		map->end = perf_mmap__read_head(map);  in perf_mmap__read_event()
286 	event = perf_mmap__read(map, &map->start, map->end);  in perf_mmap__read_event()
288 	if (!map->overwrite)  in perf_mmap__read_event()
289 		map->prev = map->start;  in perf_mmap__read_event()
295 static u64 read_perf_counter(unsigned int counter)  in read_perf_counter()
297 	unsigned int low, high;  in read_perf_counter()
306 	unsigned int low, high;  in read_timestamp()
364 static u64 read_perf_counter(unsigned int counter)  in read_perf_counter()
409 /* __riscv_xlen contains the witdh of the native base integer, here 64-bit */
426 static unsigned long csr_read_num(int csr_num)  in csr_read_num()
465 static u64 read_perf_counter(unsigned int counter)  in read_perf_counter()
476 static u64 read_perf_counter(unsigned int counter __maybe_unused) { return 0; }  in read_perf_counter()
480 int perf_mmap__read_self(struct perf_mmap *map, struct perf_counts_values *count)  in perf_mmap__read_self()  argument
482 	struct perf_event_mmap_page *pc = map->base;  in perf_mmap__read_self()
486 	if (!pc || !pc->cap_user_rdpmc)  in perf_mmap__read_self()
487 		return -1;  in perf_mmap__read_self()
490 		seq = READ_ONCE(pc->lock);  in perf_mmap__read_self()
493 		count->ena = READ_ONCE(pc->time_enabled);  in perf_mmap__read_self()
494 		count->run = READ_ONCE(pc->time_running);  in perf_mmap__read_self()
496 		if (pc->cap_user_time && count->ena != count->run) {  in perf_mmap__read_self()
498 			time_mult = READ_ONCE(pc->time_mult);  in perf_mmap__read_self()
499 			time_shift = READ_ONCE(pc->time_shift);  in perf_mmap__read_self()
500 			time_offset = READ_ONCE(pc->time_offset);  in perf_mmap__read_self()
502 			if (pc->cap_user_time_short) {  in perf_mmap__read_self()
503 				time_cycles = READ_ONCE(pc->time_cycles);  in perf_mmap__read_self()
504 				time_mask = READ_ONCE(pc->time_mask);  in perf_mmap__read_self()
508 		idx = READ_ONCE(pc->index);  in perf_mmap__read_self()
509 		cnt = READ_ONCE(pc->offset);  in perf_mmap__read_self()
510 		if (pc->cap_user_rdpmc && idx) {  in perf_mmap__read_self()
511 			s64 evcnt = read_perf_counter(idx - 1);  in perf_mmap__read_self()
512 			u16 width = READ_ONCE(pc->pmc_width);  in perf_mmap__read_self()
514 			evcnt <<= 64 - width;  in perf_mmap__read_self()
515 			evcnt >>= 64 - width;  in perf_mmap__read_self()
518 			return -1;  in perf_mmap__read_self()
521 	} while (READ_ONCE(pc->lock) != seq);  in perf_mmap__read_self()
523 	if (count->ena != count->run) {  in perf_mmap__read_self()
527 		cyc = time_cycles + ((cyc - time_cycles) & time_mask);  in perf_mmap__read_self()
531 		count->ena += delta;  in perf_mmap__read_self()
533 			count->run += delta;  in perf_mmap__read_self()
536 	count->val = cnt;  in perf_mmap__read_self()