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

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* '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()
This commit is contained in:
Linus Torvalds 2009-06-10 15:55:04 -07:00
commit 5301e0de34
2 changed files with 16 additions and 20 deletions
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31
arch/x86/include/asm/i387.h
View File

@ -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 @@ end:
#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...
*/

5
arch/x86/kernel/traps.c
View File

@ -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++;
}