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Diffstat (limited to 'kernel/arch/x86/include/asm/fpu/api.h')
| -rw-r--r-- | kernel/arch/x86/include/asm/fpu/api.h | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/kernel/arch/x86/include/asm/fpu/api.h b/kernel/arch/x86/include/asm/fpu/api.h new file mode 100644 index 000000000..1429a7c73 --- /dev/null +++ b/kernel/arch/x86/include/asm/fpu/api.h @@ -0,0 +1,48 @@ +/* + * Copyright (C) 1994 Linus Torvalds + * + * Pentium III FXSR, SSE support + * General FPU state handling cleanups + * Gareth Hughes <gareth@valinux.com>, May 2000 + * x86-64 work by Andi Kleen 2002 + */ + +#ifndef _ASM_X86_FPU_API_H +#define _ASM_X86_FPU_API_H + +/* + * Careful: __kernel_fpu_begin/end() must be called with preempt disabled + * and they don't touch the preempt state on their own. + * If you enable preemption after __kernel_fpu_begin(), preempt notifier + * should call the __kernel_fpu_end() to prevent the kernel/user FPU + * state from getting corrupted. KVM for example uses this model. + * + * All other cases use kernel_fpu_begin/end() which disable preemption + * during kernel FPU usage. + */ +extern void __kernel_fpu_begin(void); +extern void __kernel_fpu_end(void); +extern void kernel_fpu_begin(void); +extern void kernel_fpu_end(void); +extern bool irq_fpu_usable(void); + +/* + * Some instructions like VIA's padlock instructions generate a spurious + * DNA fault but don't modify SSE registers. And these instructions + * get used from interrupt context as well. To prevent these kernel instructions + * in interrupt context interacting wrongly with other user/kernel fpu usage, we + * should use them only in the context of irq_ts_save/restore() + */ +extern int irq_ts_save(void); +extern void irq_ts_restore(int TS_state); + +/* + * Query the presence of one or more xfeatures. Works on any legacy CPU as well. + * + * If 'feature_name' is set then put a human-readable description of + * the feature there as well - this can be used to print error (or success) + * messages. + */ +extern int cpu_has_xfeatures(u64 xfeatures_mask, const char **feature_name); + +#endif /* _ASM_X86_FPU_API_H */ |