1 // SPDX-License-Identifier: GPL-2.0
2 #include <sys/types.h>
3 #include <errno.h>
4 #include <unistd.h>
5 #include <stdio.h>
6 #include <stdlib.h>
7 #include <string.h>
8
9 #include "../../util/header.h"
10
11 static inline void
cpuid(unsigned int op,unsigned int * a,unsigned int * b,unsigned int * c,unsigned int * d)12 cpuid(unsigned int op, unsigned int *a, unsigned int *b, unsigned int *c,
13 unsigned int *d)
14 {
15 __asm__ __volatile__ (".byte 0x53\n\tcpuid\n\t"
16 "movl %%ebx, %%esi\n\t.byte 0x5b"
17 : "=a" (*a),
18 "=S" (*b),
19 "=c" (*c),
20 "=d" (*d)
21 : "a" (op));
22 }
23
24 static int
__get_cpuid(char * buffer,size_t sz,const char * fmt)25 __get_cpuid(char *buffer, size_t sz, const char *fmt)
26 {
27 unsigned int a, b, c, d, lvl;
28 int family = -1, model = -1, step = -1;
29 int nb;
30 char vendor[16];
31
32 cpuid(0, &lvl, &b, &c, &d);
33 strncpy(&vendor[0], (char *)(&b), 4);
34 strncpy(&vendor[4], (char *)(&d), 4);
35 strncpy(&vendor[8], (char *)(&c), 4);
36 vendor[12] = '\0';
37
38 if (lvl >= 1) {
39 cpuid(1, &a, &b, &c, &d);
40
41 family = (a >> 8) & 0xf; /* bits 11 - 8 */
42 model = (a >> 4) & 0xf; /* Bits 7 - 4 */
43 step = a & 0xf;
44
45 /* extended family */
46 if (family == 0xf)
47 family += (a >> 20) & 0xff;
48
49 /* extended model */
50 if (family >= 0x6)
51 model += ((a >> 16) & 0xf) << 4;
52 }
53 nb = scnprintf(buffer, sz, fmt, vendor, family, model, step);
54
55 /* look for end marker to ensure the entire data fit */
56 if (strchr(buffer, '$')) {
57 buffer[nb-1] = '\0';
58 return 0;
59 }
60 return ENOBUFS;
61 }
62
63 int
get_cpuid(char * buffer,size_t sz)64 get_cpuid(char *buffer, size_t sz)
65 {
66 return __get_cpuid(buffer, sz, "%s,%u,%u,%u$");
67 }
68
69 char *
get_cpuid_str(struct perf_pmu * pmu __maybe_unused)70 get_cpuid_str(struct perf_pmu *pmu __maybe_unused)
71 {
72 char *buf = malloc(128);
73
74 if (buf && __get_cpuid(buf, 128, "%s-%u-%X$") < 0) {
75 free(buf);
76 return NULL;
77 }
78 return buf;
79 }
80