OpenCloudOS-Kernel/arch/x86/include/asm/fpu/api.h

40 lines
1.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* 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);
/*
* 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 */