xref: /openbmc/linux/tools/perf/arch/x86/util/header.c (revision 12eb4683)
1 #include <sys/types.h>
2 #include <unistd.h>
3 #include <stdio.h>
4 #include <stdlib.h>
5 #include <string.h>
6 
7 #include "../../util/header.h"
8 
9 static inline void
10 cpuid(unsigned int op, unsigned int *a, unsigned int *b, unsigned int *c,
11       unsigned int *d)
12 {
13 	__asm__ __volatile__ (".byte 0x53\n\tcpuid\n\t"
14 			      "movl %%ebx, %%esi\n\t.byte 0x5b"
15 			: "=a" (*a),
16 			"=S" (*b),
17 			"=c" (*c),
18 			"=d" (*d)
19 			: "a" (op));
20 }
21 
22 int
23 get_cpuid(char *buffer, size_t sz)
24 {
25 	unsigned int a, b, c, d, lvl;
26 	int family = -1, model = -1, step = -1;
27 	int nb;
28 	char vendor[16];
29 
30 	cpuid(0, &lvl, &b, &c, &d);
31 	strncpy(&vendor[0], (char *)(&b), 4);
32 	strncpy(&vendor[4], (char *)(&d), 4);
33 	strncpy(&vendor[8], (char *)(&c), 4);
34 	vendor[12] = '\0';
35 
36 	if (lvl >= 1) {
37 		cpuid(1, &a, &b, &c, &d);
38 
39 		family = (a >> 8) & 0xf;  /* bits 11 - 8 */
40 		model  = (a >> 4) & 0xf;  /* Bits  7 - 4 */
41 		step   = a & 0xf;
42 
43 		/* extended family */
44 		if (family == 0xf)
45 			family += (a >> 20) & 0xff;
46 
47 		/* extended model */
48 		if (family >= 0x6)
49 			model += ((a >> 16) & 0xf) << 4;
50 	}
51 	nb = scnprintf(buffer, sz, "%s,%u,%u,%u$", vendor, family, model, step);
52 
53 	/* look for end marker to ensure the entire data fit */
54 	if (strchr(buffer, '$')) {
55 		buffer[nb-1] = '\0';
56 		return 0;
57 	}
58 	return -1;
59 }
60