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Diffstat (limited to 'arch/x86/boot/cpuflags.c')
| -rw-r--r-- | arch/x86/boot/cpuflags.c | 25 |
1 files changed, 20 insertions, 5 deletions
diff --git a/arch/x86/boot/cpuflags.c b/arch/x86/boot/cpuflags.c index a9fcb7cfb241..431fa5f84537 100644 --- a/arch/x86/boot/cpuflags.c +++ b/arch/x86/boot/cpuflags.c @@ -28,20 +28,35 @@ static int has_fpu(void) return fsw == 0 && (fcw & 0x103f) == 0x003f; } +/* + * For building the 16-bit code we want to explicitly specify 32-bit + * push/pop operations, rather than just saying 'pushf' or 'popf' and + * letting the compiler choose. But this is also included from the + * compressed/ directory where it may be 64-bit code, and thus needs + * to be 'pushfq' or 'popfq' in that case. + */ +#ifdef __x86_64__ +#define PUSHF "pushfq" +#define POPF "popfq" +#else +#define PUSHF "pushfl" +#define POPF "popfl" +#endif + int has_eflag(unsigned long mask) { unsigned long f0, f1; - asm volatile("pushf \n\t" - "pushf \n\t" + asm volatile(PUSHF " \n\t" + PUSHF " \n\t" "pop %0 \n\t" "mov %0,%1 \n\t" "xor %2,%1 \n\t" "push %1 \n\t" - "popf \n\t" - "pushf \n\t" + POPF " \n\t" + PUSHF " \n\t" "pop %1 \n\t" - "popf" + POPF : "=&r" (f0), "=&r" (f1) : "ri" (mask)); |