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x86, fpu: Merge fpu_save_init()

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Make 64-bit use the 32-bit version of fpu_save_init().  Remove
unused clear_fpu_state().

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <1283563039-3466-13-git-send-email-brgerst@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This commit is contained in:
Brian Gerst 2010-09-03 21:17:19 -04:00 • committed by H. Peter Anvin
parent 58a992b9cb
commit b2b57fe053
1 changed files with 4 additions and 44 deletions
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48
arch/x86/include/asm/i387.h
View file

@ -105,36 +105,6 @@ static inline int fxrstor_checking(struct i387_fxsave_struct *fx)
return err; 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) static inline int fxsave_user(struct i387_fxsave_struct __user *fx)
{ {
int err; int err;
@ -188,16 +158,6 @@ static inline void fpu_fxsave(struct fpu *fpu)
: [fx] "R" (&fpu->state->fxsave)); : [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 */ #else /* CONFIG_X86_32 */
/* perform fxrstor iff the processor has extended states, otherwise frstor */ /* 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)); : [fx] "=m" (fpu->state->fxsave));
} }
#endif /* CONFIG_X86_64 */
/* We need a safe address that is cheap to find and that is already /* We need a safe address that is cheap to find and that is already
in L1 during context switch. The best choices are unfortunately in L1 during context switch. The best choices are unfortunately
different for UP and SMP */ 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 is pending. Clear the x87 state here by setting it to fixed
values. safe_address is a random variable that should be in L1 */ values. safe_address is a random variable that should be in L1 */
alternative_input( alternative_input(
GENERIC_NOP8 GENERIC_NOP2, ASM_NOP8 ASM_NOP2,
"emms\n\t" /* clear stack tags */ "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, X86_FEATURE_FXSAVE_LEAK,
[addr] "m" (safe_address)); [addr] "m" (safe_address));
} }
#endif /* CONFIG_X86_64 */
static inline void __save_init_fpu(struct task_struct *tsk) static inline void __save_init_fpu(struct task_struct *tsk)
{ {
fpu_save_init(&tsk->thread.fpu); fpu_save_init(&tsk->thread.fpu);