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#include <stdio.h>
#include <stdlib.h>
#include <api/fs/fs.h>
#include "header.h"
#define MIDR "/regs/identification/midr_el1"
#define MIDR_SIZE 19
#define MIDR_REVISION_MASK 0xf
#define MIDR_VARIANT_SHIFT 20
#define MIDR_VARIANT_MASK (0xf << MIDR_VARIANT_SHIFT)
char *get_cpuid_str(struct perf_pmu *pmu)
{
char *buf = NULL;
char path[PATH_MAX];
const char *sysfs = sysfs__mountpoint();
int cpu;
u64 midr = 0;
struct cpu_map *cpus;
FILE *file;
if (!sysfs || !pmu || !pmu->cpus)
return NULL;
buf = malloc(MIDR_SIZE);
if (!buf)
return NULL;
/* read midr from list of cpus mapped to this pmu */
cpus = cpu_map__get(pmu->cpus);
for (cpu = 0; cpu < cpus->nr; cpu++) {
scnprintf(path, PATH_MAX, "%s/devices/system/cpu/cpu%d"MIDR,
sysfs, cpus->map[cpu]);
file = fopen(path, "r");
if (!file) {
pr_debug("fopen failed for file %s\n", path);
continue;
}
if (!fgets(buf, MIDR_SIZE, file)) {
fclose(file);
continue;
}
fclose(file);
/* Ignore/clear Variant[23:20] and
* Revision[3:0] of MIDR
*/
midr = strtoul(buf, NULL, 16);
midr &= (~(MIDR_VARIANT_MASK | MIDR_REVISION_MASK));
scnprintf(buf, MIDR_SIZE, "0x%016lx", midr);
/* got midr break loop */
break;
}
if (!midr) {
pr_err("failed to get cpuid string for PMU %s\n", pmu->name);
free(buf);
buf = NULL;
}
cpu_map__put(cpus);
return buf;
}
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