x86, fpu: Merge fpu_save_init() (b2b57fe0) · Commits · 戴 / test

arch/x86/include/asm/i387.h

+4 −44

Original line number	Diff line number	Diff line
		@@ -105,36 +105,6 @@ static inline int fxrstor_checking(struct i387_fxsave_struct *fx)
		return err;
		}

		/* AMD CPUs don't save/restore FDP/FIP/FOP unless an exception
		is pending. Clear the x87 state here by setting it to fixed
		values. The kernel data segment can be sometimes 0 and sometimes
		new user value. Both should be ok.
		Use the PDA as safe address because it should be already in L1. */
		static inline void fpu_clear(struct fpu *fpu)
		{
		struct xsave_struct *xstate = &fpu->state->xsave;
		struct i387_fxsave_struct *fx = &fpu->state->fxsave;

		/*
		* xsave header may indicate the init state of the FP.
		*/
		if (use_xsave() &&
		!(xstate->xsave_hdr.xstate_bv & XSTATE_FP))
		return;

		if (unlikely(fx->swd & X87_FSW_ES))
		asm volatile("fnclex");
		alternative_input(ASM_NOP8 ASM_NOP2,
		" emms\n" /* clear stack tags */
		" fildl %%gs:0", /* load to clear state */
		X86_FEATURE_FXSAVE_LEAK);
		}

		static inline void clear_fpu_state(struct task_struct *tsk)
		{
		fpu_clear(&tsk->thread.fpu);
		}

		static inline int fxsave_user(struct i387_fxsave_struct __user *fx)
		{
		int err;
		@@ -188,16 +158,6 @@ static inline void fpu_fxsave(struct fpu *fpu)
		: [fx] "R" (&fpu->state->fxsave));
		}

		static inline void fpu_save_init(struct fpu *fpu)
		{
		if (use_xsave())
		fpu_xsave(fpu);
		else
		fpu_fxsave(fpu);

		fpu_clear(fpu);
		}

		#else /* CONFIG_X86_32 */

		/* perform fxrstor iff the processor has extended states, otherwise frstor */
		@@ -222,6 +182,8 @@ static inline void fpu_fxsave(struct fpu *fpu)
		: [fx] "=m" (fpu->state->fxsave));
		}

		#endif /* CONFIG_X86_64 */

		/* We need a safe address that is cheap to find and that is already
		in L1 during context switch. The best choices are unfortunately
		different for UP and SMP */
		@@ -259,15 +221,13 @@ static inline void fpu_save_init(struct fpu *fpu)
		is pending. Clear the x87 state here by setting it to fixed
		values. safe_address is a random variable that should be in L1 */
		alternative_input(
		GENERIC_NOP8 GENERIC_NOP2,
		ASM_NOP8 ASM_NOP2,
		"emms\n\t" /* clear stack tags */
		"fildl %[addr]", /* set F?P to defined value */
		"fildl %P[addr]", /* set F?P to defined value */
		X86_FEATURE_FXSAVE_LEAK,
		[addr] "m" (safe_address));
		}

		#endif /* CONFIG_X86_64 */

		static inline void __save_init_fpu(struct task_struct *tsk)
		{
		fpu_save_init(&tsk->thread.fpu);

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