tools/perf/arch/arm64/util/header.c

   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
  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
  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
  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 }