diff options
Diffstat (limited to 'arch/x86/include/asm/fpu/api.h')
| -rw-r--r-- | arch/x86/include/asm/fpu/api.h | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/x86/include/asm/fpu/api.h b/arch/x86/include/asm/fpu/api.h index 67a4f1cb2aac..ed33a14188f6 100644 --- a/arch/x86/include/asm/fpu/api.h +++ b/arch/x86/include/asm/fpu/api.h @@ -32,7 +32,19 @@ extern void fpregs_mark_activate(void); /* Code that is unaware of kernel_fpu_begin_mask() can use this */ static inline void kernel_fpu_begin(void) { +#ifdef CONFIG_X86_64 + /* + * Any 64-bit code that uses 387 instructions must explicitly request + * KFPU_387. + */ + kernel_fpu_begin_mask(KFPU_MXCSR); +#else + /* + * 32-bit kernel code may use 387 operations as well as SSE2, etc, + * as long as it checks that the CPU has the required capability. + */ kernel_fpu_begin_mask(KFPU_387 | KFPU_MXCSR); +#endif } /* |