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torvalds
GitHub Repository: torvalds/linux
 Path: blob/master/arch/x86/kernel/fpu/legacy.h
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/* SPDX-License-Identifier: GPL-2.0 */

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#ifndef __X86_KERNEL_FPU_LEGACY_H

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#define __X86_KERNEL_FPU_LEGACY_H

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#include <asm/fpu/types.h>

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extern unsigned int mxcsr_feature_mask;

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static inline void ldmxcsr(u32 mxcsr)

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{

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	asm volatile("ldmxcsr %0" :: "m" (mxcsr));

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}

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/*

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 * Returns 0 on success or the trap number when the operation raises an

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 * exception.

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 */

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#define user_insn(insn, output, input...)				\

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({									\

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	int err;							\

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									\

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	might_fault();							\

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									\

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	asm volatile(ASM_STAC "\n"					\

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		     "1: " #insn "\n"					\

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		     "2: " ASM_CLAC "\n"				\

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		     _ASM_EXTABLE_TYPE(1b, 2b, EX_TYPE_FAULT_MCE_SAFE)	\

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		     : [err] "=a" (err), output				\

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		     : "0"(0), input);					\

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	err;								\

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})

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#define kernel_insn_err(insn, output, input...)				\

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({									\

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	int err;							\

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	asm volatile("1:" #insn "\n\t"					\

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		     "2:\n"						\

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		     _ASM_EXTABLE_TYPE_REG(1b, 2b, EX_TYPE_EFAULT_REG, %[err]) \

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		     : [err] "=r" (err), output				\

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		     : "0"(0), input);					\

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	err;								\

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})

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#define kernel_insn(insn, output, input...)				\

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	asm volatile("1:" #insn "\n\t"					\

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		     "2:\n"						\

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		     _ASM_EXTABLE_TYPE(1b, 2b, EX_TYPE_FPU_RESTORE)	\

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		     : output : input)

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static inline int fnsave_to_user_sigframe(struct fregs_state __user *fx)

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{

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	return user_insn(fnsave %[fx]; fwait,  [fx] "=m" (*fx), "m" (*fx));

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}

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static inline int fxsave_to_user_sigframe(struct fxregs_state __user *fx)

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{

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	if (IS_ENABLED(CONFIG_X86_32))

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		return user_insn(fxsave %[fx], [fx] "=m" (*fx), "m" (*fx));

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	else

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		return user_insn(fxsaveq %[fx], [fx] "=m" (*fx), "m" (*fx));

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}

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static inline void fxrstor(struct fxregs_state *fx)

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{

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	if (IS_ENABLED(CONFIG_X86_32))

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		kernel_insn(fxrstor %[fx], "=m" (*fx), [fx] "m" (*fx));

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	else

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		kernel_insn(fxrstorq %[fx], "=m" (*fx), [fx] "m" (*fx));

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}

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static inline int fxrstor_safe(struct fxregs_state *fx)

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{

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	if (IS_ENABLED(CONFIG_X86_32))

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		return kernel_insn_err(fxrstor %[fx], "=m" (*fx), [fx] "m" (*fx));

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	else

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		return kernel_insn_err(fxrstorq %[fx], "=m" (*fx), [fx] "m" (*fx));

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}

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static inline int fxrstor_from_user_sigframe(struct fxregs_state __user *fx)

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{

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	if (IS_ENABLED(CONFIG_X86_32))

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		return user_insn(fxrstor %[fx], "=m" (*fx), [fx] "m" (*fx));

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	else

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		return user_insn(fxrstorq %[fx], "=m" (*fx), [fx] "m" (*fx));

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}

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static inline void frstor(struct fregs_state *fx)

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{

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	kernel_insn(frstor %[fx], "=m" (*fx), [fx] "m" (*fx));

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}

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static inline int frstor_safe(struct fregs_state *fx)

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{

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	return kernel_insn_err(frstor %[fx], "=m" (*fx), [fx] "m" (*fx));

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}

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static inline int frstor_from_user_sigframe(struct fregs_state __user *fx)

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{

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	return user_insn(frstor %[fx], "=m" (*fx), [fx] "m" (*fx));

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}

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static inline void fxsave(struct fxregs_state *fx)

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{

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	if (IS_ENABLED(CONFIG_X86_32))

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		asm volatile( "fxsave %[fx]" : [fx] "=m" (*fx));

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	else

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		asm volatile("fxsaveq %[fx]" : [fx] "=m" (*fx));

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}

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#endif

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