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, fpu: Merge fpu_save_init()
x86-32, fpu: Rewrite fpu_save_init()
x86, fpu: Remove PSHUFB_XMM5_* macros
x86, fpu: Remove unnecessary ifdefs from i387 code.
x86-32, fpu: Remove math_emulate stub
x86-64, fpu: Simplify constraints for fxsave/fxtstor
x86-64, fpu: Fix %cs value in convert_from_fxsr()
x86-64, fpu: Disable preemption when using TS_USEDFPU
x86, fpu: Merge __save_init_fpu()
x86, fpu: Merge tolerant_fwait()
x86, fpu: Merge fpu_init()
x86: Use correct type for %cr4
x86, xsave: Disable xsave in i387 emulation mode
Fixed up fxsaveq-induced conflict in arch/x86/include/asm/i387.h
diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h
index 70f105b..4aa2bb3 100644
--- a/arch/x86/include/asm/i387.h
+++ b/arch/x86/include/asm/i387.h
@@ -55,6 +55,12 @@
extern int restore_i387_xstate_ia32(void __user *buf);
#endif
+#ifdef CONFIG_MATH_EMULATION
+extern void finit_soft_fpu(struct i387_soft_struct *soft);
+#else
+static inline void finit_soft_fpu(struct i387_soft_struct *soft) {}
+#endif
+
#define X87_FSW_ES (1 << 7) /* Exception Summary */
static __always_inline __pure bool use_xsaveopt(void)
@@ -67,6 +73,11 @@
return static_cpu_has(X86_FEATURE_XSAVE);
}
+static __always_inline __pure bool use_fxsr(void)
+{
+ return static_cpu_has(X86_FEATURE_FXSR);
+}
+
extern void __sanitize_i387_state(struct task_struct *);
static inline void sanitize_i387_state(struct task_struct *tsk)
@@ -77,19 +88,11 @@
}
#ifdef CONFIG_X86_64
-
-/* Ignore delayed exceptions from user space */
-static inline void tolerant_fwait(void)
-{
- asm volatile("1: fwait\n"
- "2:\n"
- _ASM_EXTABLE(1b, 2b));
-}
-
static inline int fxrstor_checking(struct i387_fxsave_struct *fx)
{
int err;
+ /* See comment in fxsave() below. */
asm volatile("1: rex64/fxrstor (%[fx])\n\t"
"2:\n"
".section .fixup,\"ax\"\n"
@@ -98,44 +101,10 @@
".previous\n"
_ASM_EXTABLE(1b, 3b)
: [err] "=r" (err)
-#if 0 /* See comment in fxsave() below. */
- : [fx] "r" (fx), "m" (*fx), "0" (0));
-#else
- : [fx] "cdaSDb" (fx), "m" (*fx), "0" (0));
-#endif
+ : [fx] "R" (fx), "m" (*fx), "0" (0));
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;
@@ -149,6 +118,7 @@
if (unlikely(err))
return -EFAULT;
+ /* See comment in fxsave() below. */
asm volatile("1: rex64/fxsave (%[fx])\n\t"
"2:\n"
".section .fixup,\"ax\"\n"
@@ -157,11 +127,7 @@
".previous\n"
_ASM_EXTABLE(1b, 3b)
: [err] "=r" (err), "=m" (*fx)
-#if 0 /* See comment in fxsave() below. */
- : [fx] "r" (fx), "0" (0));
-#else
- : [fx] "cdaSDb" (fx), "0" (0));
-#endif
+ : [fx] "R" (fx), "0" (0));
if (unlikely(err) &&
__clear_user(fx, sizeof(struct i387_fxsave_struct)))
err = -EFAULT;
@@ -175,56 +141,29 @@
uses any extended registers for addressing, a second REX prefix
will be generated (to the assembler, rex64 followed by semicolon
is a separate instruction), and hence the 64-bitness is lost. */
+
#ifdef CONFIG_AS_FXSAVEQ
/* Using "fxsaveq %0" would be the ideal choice, but is only supported
starting with gas 2.16. */
__asm__ __volatile__("fxsaveq %0"
: "=m" (fpu->state->fxsave));
-#elif 0
+#else
/* Using, as a workaround, the properly prefixed form below isn't
accepted by any binutils version so far released, complaining that
the same type of prefix is used twice if an extended register is
- needed for addressing (fix submitted to mainline 2005-11-21). */
- __asm__ __volatile__("rex64/fxsave %0"
- : "=m" (fpu->state->fxsave));
-#else
- /* This, however, we can work around by forcing the compiler to select
+ needed for addressing (fix submitted to mainline 2005-11-21).
+ asm volatile("rex64/fxsave %0"
+ : "=m" (fpu->state->fxsave));
+ This, however, we can work around by forcing the compiler to select
an addressing mode that doesn't require extended registers. */
- __asm__ __volatile__("rex64/fxsave (%1)"
- : "=m" (fpu->state->fxsave)
- : "cdaSDb" (&fpu->state->fxsave));
+ asm volatile("rex64/fxsave (%[fx])"
+ : "=m" (fpu->state->fxsave)
+ : [fx] "R" (&fpu->state->fxsave));
#endif
}
-static inline void fpu_save_init(struct fpu *fpu)
-{
- if (use_xsave())
- fpu_xsave(fpu);
- else
- fpu_fxsave(fpu);
-
- fpu_clear(fpu);
-}
-
-static inline void __save_init_fpu(struct task_struct *tsk)
-{
- fpu_save_init(&tsk->thread.fpu);
- task_thread_info(tsk)->status &= ~TS_USEDFPU;
-}
-
#else /* CONFIG_X86_32 */
-#ifdef CONFIG_MATH_EMULATION
-extern void finit_soft_fpu(struct i387_soft_struct *soft);
-#else
-static inline void finit_soft_fpu(struct i387_soft_struct *soft) {}
-#endif
-
-static inline void tolerant_fwait(void)
-{
- asm volatile("fnclex ; fwait");
-}
-
/* perform fxrstor iff the processor has extended states, otherwise frstor */
static inline int fxrstor_checking(struct i387_fxsave_struct *fx)
{
@@ -241,6 +180,14 @@
return 0;
}
+static inline void fpu_fxsave(struct fpu *fpu)
+{
+ asm volatile("fxsave %[fx]"
+ : [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 */
@@ -256,47 +203,33 @@
static inline void fpu_save_init(struct fpu *fpu)
{
if (use_xsave()) {
- struct xsave_struct *xstate = &fpu->state->xsave;
- struct i387_fxsave_struct *fx = &fpu->state->fxsave;
-
fpu_xsave(fpu);
/*
* xsave header may indicate the init state of the FP.
*/
- if (!(xstate->xsave_hdr.xstate_bv & XSTATE_FP))
- goto end;
-
- if (unlikely(fx->swd & X87_FSW_ES))
- asm volatile("fnclex");
-
- /*
- * we can do a simple return here or be paranoid :)
- */
- goto clear_state;
+ if (!(fpu->state->xsave.xsave_hdr.xstate_bv & XSTATE_FP))
+ return;
+ } else if (use_fxsr()) {
+ fpu_fxsave(fpu);
+ } else {
+ asm volatile("fsave %[fx]; fwait"
+ : [fx] "=m" (fpu->state->fsave));
+ return;
}
- /* Use more nops than strictly needed in case the compiler
- varies code */
- alternative_input(
- "fnsave %[fx] ;fwait;" GENERIC_NOP8 GENERIC_NOP4,
- "fxsave %[fx]\n"
- "bt $7,%[fsw] ; jnc 1f ; fnclex\n1:",
- X86_FEATURE_FXSR,
- [fx] "m" (fpu->state->fxsave),
- [fsw] "m" (fpu->state->fxsave.swd) : "memory");
-clear_state:
+ if (unlikely(fpu->state->fxsave.swd & X87_FSW_ES))
+ asm volatile("fnclex");
+
/* AMD K7/K8 CPUs don't save/restore FDP/FIP/FOP unless an exception
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));
-end:
- ;
}
static inline void __save_init_fpu(struct task_struct *tsk)
@@ -305,9 +238,6 @@
task_thread_info(tsk)->status &= ~TS_USEDFPU;
}
-
-#endif /* CONFIG_X86_64 */
-
static inline int fpu_fxrstor_checking(struct fpu *fpu)
{
return fxrstor_checking(&fpu->state->fxsave);
@@ -344,7 +274,10 @@
static inline void __clear_fpu(struct task_struct *tsk)
{
if (task_thread_info(tsk)->status & TS_USEDFPU) {
- tolerant_fwait();
+ /* Ignore delayed exceptions from user space */
+ asm volatile("1: fwait\n"
+ "2:\n"
+ _ASM_EXTABLE(1b, 2b));
task_thread_info(tsk)->status &= ~TS_USEDFPU;
stts();
}
@@ -405,19 +338,6 @@
stts();
}
-#ifdef CONFIG_X86_64
-
-static inline void save_init_fpu(struct task_struct *tsk)
-{
- __save_init_fpu(tsk);
- stts();
-}
-
-#define unlazy_fpu __unlazy_fpu
-#define clear_fpu __clear_fpu
-
-#else /* CONFIG_X86_32 */
-
/*
* These disable preemption on their own and are safe
*/
@@ -443,8 +363,6 @@
preempt_enable();
}
-#endif /* CONFIG_X86_64 */
-
/*
* i387 state interaction
*/
@@ -508,7 +426,4 @@
#endif /* __ASSEMBLY__ */
-#define PSHUFB_XMM5_XMM0 .byte 0x66, 0x0f, 0x38, 0x00, 0xc5
-#define PSHUFB_XMM5_XMM6 .byte 0x66, 0x0f, 0x38, 0x00, 0xf5
-
#endif /* _ASM_X86_I387_H */