xref: /openbmc/linux/tools/perf/arch/x86/util/header.c (revision e3b9f1e8)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <sys/types.h>
3 #include <unistd.h>
4 #include <stdio.h>
5 #include <stdlib.h>
6 #include <string.h>
7 
8 #include "../../util/header.h"
9 
10 static inline void
11 cpuid(unsigned int op, unsigned int *a, unsigned int *b, unsigned int *c,
12       unsigned int *d)
13 {
14 	__asm__ __volatile__ (".byte 0x53\n\tcpuid\n\t"
15 			      "movl %%ebx, %%esi\n\t.byte 0x5b"
16 			: "=a" (*a),
17 			"=S" (*b),
18 			"=c" (*c),
19 			"=d" (*d)
20 			: "a" (op));
21 }
22 
23 static int
24 __get_cpuid(char *buffer, size_t sz, const char *fmt)
25 {
26 	unsigned int a, b, c, d, lvl;
27 	int family = -1, model = -1, step = -1;
28 	int nb;
29 	char vendor[16];
30 
31 	cpuid(0, &lvl, &b, &c, &d);
32 	strncpy(&vendor[0], (char *)(&b), 4);
33 	strncpy(&vendor[4], (char *)(&d), 4);
34 	strncpy(&vendor[8], (char *)(&c), 4);
35 	vendor[12] = '\0';
36 
37 	if (lvl >= 1) {
38 		cpuid(1, &a, &b, &c, &d);
39 
40 		family = (a >> 8) & 0xf;  /* bits 11 - 8 */
41 		model  = (a >> 4) & 0xf;  /* Bits  7 - 4 */
42 		step   = a & 0xf;
43 
44 		/* extended family */
45 		if (family == 0xf)
46 			family += (a >> 20) & 0xff;
47 
48 		/* extended model */
49 		if (family >= 0x6)
50 			model += ((a >> 16) & 0xf) << 4;
51 	}
52 	nb = scnprintf(buffer, sz, fmt, vendor, family, model, step);
53 
54 	/* look for end marker to ensure the entire data fit */
55 	if (strchr(buffer, '$')) {
56 		buffer[nb-1] = '\0';
57 		return 0;
58 	}
59 	return -1;
60 }
61 
62 int
63 get_cpuid(char *buffer, size_t sz)
64 {
65 	return __get_cpuid(buffer, sz, "%s,%u,%u,%u$");
66 }
67 
68 char *
69 get_cpuid_str(struct perf_pmu *pmu __maybe_unused)
70 {
71 	char *buf = malloc(128);
72 
73 	if (buf && __get_cpuid(buf, 128, "%s-%u-%X$") < 0) {
74 		free(buf);
75 		return NULL;
76 	}
77 	return buf;
78 }
79