1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef PERF_CPUID_H 3 #define PERF_CPUID_H 1 4 5 6 static inline void 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