1// SPDX-License-Identifier: GPL-2.0-only
  2#include <perf/cpumap.h>
  3#include <stdlib.h>
  4#include <linux/refcount.h>
  5#include <internal/cpumap.h>
  6#include <asm/bug.h>
  7#include <stdio.h>
  8#include <string.h>
  9#include <unistd.h>
 10#include <ctype.h>
 11#include <limits.h>
 12
 13struct perf_cpu_map *perf_cpu_map__dummy_new(void)
 14{
 15	struct perf_cpu_map *cpus = malloc(sizeof(*cpus) + sizeof(int));
 16
 17	if (cpus != NULL) {
 18		cpus->nr = 1;
 19		cpus->map[0] = -1;
 20		refcount_set(&cpus->refcnt, 1);
 21	}
 22
 23	return cpus;
 24}
 25
 26static void cpu_map__delete(struct perf_cpu_map *map)
 27{
 28	if (map) {
 29		WARN_ONCE(refcount_read(&map->refcnt) != 0,
 30			  "cpu_map refcnt unbalanced\n");
 31		free(map);
 32	}
 33}
 34
 35struct perf_cpu_map *perf_cpu_map__get(struct perf_cpu_map *map)
 36{
 37	if (map)
 38		refcount_inc(&map->refcnt);
 39	return map;
 40}
 41
 42void perf_cpu_map__put(struct perf_cpu_map *map)
 43{
 44	if (map && refcount_dec_and_test(&map->refcnt))
 45		cpu_map__delete(map);
 46}
 47
 48static struct perf_cpu_map *cpu_map__default_new(void)
 49{
 50	struct perf_cpu_map *cpus;
 51	int nr_cpus;
 52
 53	nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
 54	if (nr_cpus < 0)
 55		return NULL;
 56
 57	cpus = malloc(sizeof(*cpus) + nr_cpus * sizeof(int));
 58	if (cpus != NULL) {
 59		int i;
 60
 61		for (i = 0; i < nr_cpus; ++i)
 62			cpus->map[i] = i;
 63
 64		cpus->nr = nr_cpus;
 65		refcount_set(&cpus->refcnt, 1);
 66	}
 67
 68	return cpus;
 69}
 70
 71static struct perf_cpu_map *cpu_map__trim_new(int nr_cpus, int *tmp_cpus)
 72{
 73	size_t payload_size = nr_cpus * sizeof(int);
 74	struct perf_cpu_map *cpus = malloc(sizeof(*cpus) + payload_size);
 75
 76	if (cpus != NULL) {
 77		cpus->nr = nr_cpus;
 78		memcpy(cpus->map, tmp_cpus, payload_size);
 79		refcount_set(&cpus->refcnt, 1);
 80	}
 81
 82	return cpus;
 83}
 84
 85struct perf_cpu_map *perf_cpu_map__read(FILE *file)
 86{
 87	struct perf_cpu_map *cpus = NULL;
 88	int nr_cpus = 0;
 89	int *tmp_cpus = NULL, *tmp;
 90	int max_entries = 0;
 91	int n, cpu, prev;
 92	char sep;
 93
 94	sep = 0;
 95	prev = -1;
 96	for (;;) {
 97		n = fscanf(file, "%u%c", &cpu, &sep);
 98		if (n <= 0)
 99			break;
100		if (prev >= 0) {
101			int new_max = nr_cpus + cpu - prev - 1;
102
103			WARN_ONCE(new_max >= MAX_NR_CPUS, "Perf can support %d CPUs. "
104							  "Consider raising MAX_NR_CPUS\n", MAX_NR_CPUS);
105
106			if (new_max >= max_entries) {
107				max_entries = new_max + MAX_NR_CPUS / 2;
108				tmp = realloc(tmp_cpus, max_entries * sizeof(int));
109				if (tmp == NULL)
110					goto out_free_tmp;
111				tmp_cpus = tmp;
112			}
113
114			while (++prev < cpu)
115				tmp_cpus[nr_cpus++] = prev;
116		}
117		if (nr_cpus == max_entries) {
118			max_entries += MAX_NR_CPUS;
119			tmp = realloc(tmp_cpus, max_entries * sizeof(int));
120			if (tmp == NULL)
121				goto out_free_tmp;
122			tmp_cpus = tmp;
123		}
124
125		tmp_cpus[nr_cpus++] = cpu;
126		if (n == 2 && sep == '-')
127			prev = cpu;
128		else
129			prev = -1;
130		if (n == 1 || sep == '\n')
131			break;
132	}
133
134	if (nr_cpus > 0)
135		cpus = cpu_map__trim_new(nr_cpus, tmp_cpus);
136	else
137		cpus = cpu_map__default_new();
138out_free_tmp:
139	free(tmp_cpus);
140	return cpus;
141}
142
143static struct perf_cpu_map *cpu_map__read_all_cpu_map(void)
144{
145	struct perf_cpu_map *cpus = NULL;
146	FILE *onlnf;
147
148	onlnf = fopen("/sys/devices/system/cpu/online", "r");
149	if (!onlnf)
150		return cpu_map__default_new();
151
152	cpus = perf_cpu_map__read(onlnf);
153	fclose(onlnf);
154	return cpus;
155}
156
157struct perf_cpu_map *perf_cpu_map__new(const char *cpu_list)
158{
159	struct perf_cpu_map *cpus = NULL;
160	unsigned long start_cpu, end_cpu = 0;
161	char *p = NULL;
162	int i, nr_cpus = 0;
163	int *tmp_cpus = NULL, *tmp;
164	int max_entries = 0;
165
166	if (!cpu_list)
167		return cpu_map__read_all_cpu_map();
168
169	/*
170	 * must handle the case of empty cpumap to cover
171	 * TOPOLOGY header for NUMA nodes with no CPU
172	 * ( e.g., because of CPU hotplug)
173	 */
174	if (!isdigit(*cpu_list) && *cpu_list != '\0')
175		goto out;
176
177	while (isdigit(*cpu_list)) {
178		p = NULL;
179		start_cpu = strtoul(cpu_list, &p, 0);
180		if (start_cpu >= INT_MAX
181		    || (*p != '\0' && *p != ',' && *p != '-'))
182			goto invalid;
183
184		if (*p == '-') {
185			cpu_list = ++p;
186			p = NULL;
187			end_cpu = strtoul(cpu_list, &p, 0);
188
189			if (end_cpu >= INT_MAX || (*p != '\0' && *p != ','))
190				goto invalid;
191
192			if (end_cpu < start_cpu)
193				goto invalid;
194		} else {
195			end_cpu = start_cpu;
196		}
197
198		WARN_ONCE(end_cpu >= MAX_NR_CPUS, "Perf can support %d CPUs. "
199						  "Consider raising MAX_NR_CPUS\n", MAX_NR_CPUS);
200
201		for (; start_cpu <= end_cpu; start_cpu++) {
202			/* check for duplicates */
203			for (i = 0; i < nr_cpus; i++)
204				if (tmp_cpus[i] == (int)start_cpu)
205					goto invalid;
206
207			if (nr_cpus == max_entries) {
208				max_entries += MAX_NR_CPUS;
209				tmp = realloc(tmp_cpus, max_entries * sizeof(int));
210				if (tmp == NULL)
211					goto invalid;
212				tmp_cpus = tmp;
213			}
214			tmp_cpus[nr_cpus++] = (int)start_cpu;
215		}
216		if (*p)
217			++p;
218
219		cpu_list = p;
220	}
221
222	if (nr_cpus > 0)
223		cpus = cpu_map__trim_new(nr_cpus, tmp_cpus);
224	else if (*cpu_list != '\0')
225		cpus = cpu_map__default_new();
226	else
227		cpus = perf_cpu_map__dummy_new();
228invalid:
229	free(tmp_cpus);
230out:
231	return cpus;
232}
233
234int perf_cpu_map__cpu(const struct perf_cpu_map *cpus, int idx)
235{
236	if (idx < cpus->nr)
237		return cpus->map[idx];
238
239	return -1;
240}
241
242int perf_cpu_map__nr(const struct perf_cpu_map *cpus)
243{
244	return cpus ? cpus->nr : 1;
245}
246
247bool perf_cpu_map__empty(const struct perf_cpu_map *map)
248{
249	return map ? map->map[0] == -1 : true;
250}
251
252int perf_cpu_map__idx(struct perf_cpu_map *cpus, int cpu)
253{
254	int i;
255
256	for (i = 0; i < cpus->nr; ++i) {
257		if (cpus->map[i] == cpu)
258			return i;
259	}
260
261	return -1;
262}
263
264int perf_cpu_map__max(struct perf_cpu_map *map)
265{
266	int i, max = -1;
267
268	for (i = 0; i < map->nr; i++) {
269		if (map->map[i] > max)
270			max = map->map[i];
271	}
272
273	return max;
274}