Commit 5301e0de authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 

* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86_64: fix incorrect comments
  x86: unify restore_fpu_checking
  x86_32: introduce restore_fpu_checking()
parents c44e3ed5 4ecf4584

arch/x86/include/asm/i387.h

+15 −16
Original line number Diff line number Diff line
@@ -67,7 +67,7 @@ static inline int fxrstor_checking(struct i387_fxsave_struct *fx) 
		     ".previous\n"

		     _ASM_EXTABLE(1b, 3b)

		     : [err] "=r" (err)

#if 0 /* See comment in __save_init_fpu() below. */

#if 0 /* See comment in fxsave() below. */

		     : [fx] "r" (fx), "m" (*fx), "0" (0));

#else

		     : [fx] "cdaSDb" (fx), "m" (*fx), "0" (0));
@@ -75,14 +75,6 @@ static inline int fxrstor_checking(struct i387_fxsave_struct *fx) 
	return err;

}



static inline int restore_fpu_checking(struct task_struct *tsk)

{

	if (task_thread_info(tsk)->status & TS_XSAVE)

		return xrstor_checking(&tsk->thread.xstate->xsave);

	else

		return fxrstor_checking(&tsk->thread.xstate->fxsave);

}



/* 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
@@ -120,7 +112,7 @@ static inline int fxsave_user(struct i387_fxsave_struct __user *fx) 
		     ".previous\n"

		     _ASM_EXTABLE(1b, 3b)

		     : [err] "=r" (err), "=m" (*fx)

#if 0 /* See comment in __fxsave_clear() below. */

#if 0 /* See comment in fxsave() below. */

		     : [fx] "r" (fx), "0" (0));

#else

		     : [fx] "cdaSDb" (fx), "0" (0));
@@ -185,12 +177,9 @@ static inline void tolerant_fwait(void) 
	asm volatile("fnclex ; fwait");

}



static inline void restore_fpu(struct task_struct *tsk)

/* perform fxrstor iff the processor has extended states, otherwise frstor */

static inline int fxrstor_checking(struct i387_fxsave_struct *fx)

{

	if (task_thread_info(tsk)->status & TS_XSAVE) {

		xrstor_checking(&tsk->thread.xstate->xsave);

		return;

	}

	/*

	 * The "nop" is needed to make the instructions the same

	 * length.
@@ -199,7 +188,9 @@ static inline void restore_fpu(struct task_struct *tsk) 
		"nop ; frstor %1",

		"fxrstor %1",

		X86_FEATURE_FXSR,

		"m" (tsk->thread.xstate->fxsave));

		"m" (*fx));



	return 0;

}



/* We need a safe address that is cheap to find and that is already
@@ -262,6 +253,14 @@ static inline void __save_init_fpu(struct task_struct *tsk) 


#endif	/* CONFIG_X86_64 */



static inline int restore_fpu_checking(struct task_struct *tsk)

{

	if (task_thread_info(tsk)->status & TS_XSAVE)

		return xrstor_checking(&tsk->thread.xstate->xsave);

	else

		return fxrstor_checking(&tsk->thread.xstate->fxsave);

}



/*

 * Signal frame handlers...

 */

arch/x86/kernel/traps.c

+1 −4
Original line number Diff line number Diff line
@@ -839,9 +839,6 @@ asmlinkage void math_state_restore(void) 
	}



	clts();				/* Allow maths ops (or we recurse) */

#ifdef CONFIG_X86_32

	restore_fpu(tsk);

#else

	/*

	 * Paranoid restore. send a SIGSEGV if we fail to restore the state.

	 */
@@ -850,7 +847,7 @@ asmlinkage void math_state_restore(void) 
		force_sig(SIGSEGV, tsk);

		return;

	}

#endif



	thread->status |= TS_USEDFPU;	/* So we fnsave on switch_to() */

	tsk->fpu_counter++;

}