35 lines
833 B
C
35 lines
833 B
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef PERF_CPUID_H
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#define PERF_CPUID_H 1
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static inline void
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cpuid(unsigned int op, unsigned int op2, unsigned int *a, unsigned int *b,
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unsigned int *c, unsigned int *d)
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{
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/*
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* Preserve %ebx/%rbx register by either placing it in %rdi or saving it
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* on the stack - x86-64 needs to avoid the stack red zone. In PIC
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* compilations %ebx contains the address of the global offset
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* table. %rbx is occasionally used to address stack variables in
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* presence of dynamic allocas.
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*/
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asm(
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#if defined(__x86_64__)
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"mov %%rbx, %%rdi\n"
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"cpuid\n"
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"xchg %%rdi, %%rbx\n"
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#else
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"pushl %%ebx\n"
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"cpuid\n"
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"movl %%ebx, %%edi\n"
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"popl %%ebx\n"
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#endif
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: "=a"(*a), "=D"(*b), "=c"(*c), "=d"(*d)
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: "a"(op), "2"(op2));
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}
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void get_cpuid_0(char *vendor, unsigned int *lvl);
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#endif
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