1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef PERF_CPUID_H
3 #define PERF_CPUID_H 1
4
5
6 static inline void
cpuid(unsigned int op,unsigned int op2,unsigned int * a,unsigned int * b,unsigned int * c,unsigned int * d)7 cpuid(unsigned int op, unsigned int op2, unsigned int *a, unsigned int *b,
8 unsigned int *c, unsigned int *d)
9 {
10 /*
11 * Preserve %ebx/%rbx register by either placing it in %rdi or saving it
12 * on the stack - x86-64 needs to avoid the stack red zone. In PIC
13 * compilations %ebx contains the address of the global offset
14 * table. %rbx is occasionally used to address stack variables in
15 * presence of dynamic allocas.
16 */
17 asm(
18 #if defined(__x86_64__)
19 "mov %%rbx, %%rdi\n"
20 "cpuid\n"
21 "xchg %%rdi, %%rbx\n"
22 #else
23 "pushl %%ebx\n"
24 "cpuid\n"
25 "movl %%ebx, %%edi\n"
26 "popl %%ebx\n"
27 #endif
28 : "=a"(*a), "=D"(*b), "=c"(*c), "=d"(*d)
29 : "a"(op), "2"(op2));
30 }
31
32 void get_cpuid_0(char *vendor, unsigned int *lvl);
33
34 #endif
35
