1 #include <stdio.h>
2 #include <stdlib.h>
3 #include <perf/cpumap.h>
4 #include <util/cpumap.h>
5 #include <internal/cpumap.h>
6 #include <api/fs/fs.h>
7 #include <errno.h>
8 #include "debug.h"
9 #include "header.h"
10
11 #define MIDR "/regs/identification/midr_el1"
12 #define MIDR_SIZE 19
13 #define MIDR_REVISION_MASK 0xf
14 #define MIDR_VARIANT_SHIFT 20
15 #define MIDR_VARIANT_MASK (0xf << MIDR_VARIANT_SHIFT)
16
_get_cpuid(char * buf,size_t sz,struct perf_cpu_map * cpus)17 static int _get_cpuid(char *buf, size_t sz, struct perf_cpu_map *cpus)
18 {
19 const char *sysfs = sysfs__mountpoint();
20 u64 midr = 0;
21 int cpu;
22
23 if (!sysfs || sz < MIDR_SIZE)
24 return EINVAL;
25
26 cpus = perf_cpu_map__get(cpus);
27
28 for (cpu = 0; cpu < perf_cpu_map__nr(cpus); cpu++) {
29 char path[PATH_MAX];
30 FILE *file;
31
32 scnprintf(path, PATH_MAX, "%s/devices/system/cpu/cpu%d"MIDR,
33 sysfs, cpus->map[cpu]);
34
35 file = fopen(path, "r");
36 if (!file) {
37 pr_debug("fopen failed for file %s\n", path);
38 continue;
39 }
40
41 if (!fgets(buf, MIDR_SIZE, file)) {
42 fclose(file);
43 continue;
44 }
45 fclose(file);
46
47 /* Ignore/clear Variant[23:20] and
48 * Revision[3:0] of MIDR
49 */
50 midr = strtoul(buf, NULL, 16);
51 midr &= (~(MIDR_VARIANT_MASK | MIDR_REVISION_MASK));
52 scnprintf(buf, MIDR_SIZE, "0x%016lx", midr);
53 /* got midr break loop */
54 break;
55 }
56
57 perf_cpu_map__put(cpus);
58
59 if (!midr)
60 return EINVAL;
61
62 return 0;
63 }
64
get_cpuid(char * buf,size_t sz)65 int get_cpuid(char *buf, size_t sz)
66 {
67 struct perf_cpu_map *cpus = perf_cpu_map__new(NULL);
68 int ret;
69
70 if (!cpus)
71 return EINVAL;
72
73 ret = _get_cpuid(buf, sz, cpus);
74
75 perf_cpu_map__put(cpus);
76
77 return ret;
78 }
79
get_cpuid_str(struct perf_pmu * pmu)80 char *get_cpuid_str(struct perf_pmu *pmu)
81 {
82 char *buf = NULL;
83 int res;
84
85 if (!pmu || !pmu->cpus)
86 return NULL;
87
88 buf = malloc(MIDR_SIZE);
89 if (!buf)
90 return NULL;
91
92 /* read midr from list of cpus mapped to this pmu */
93 res = _get_cpuid(buf, MIDR_SIZE, pmu->cpus);
94 if (res) {
95 pr_err("failed to get cpuid string for PMU %s\n", pmu->name);
96 free(buf);
97 buf = NULL;
98 }
99
100 return buf;
101 }
102