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