1 files changed, 50 insertions, 135 deletions

diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h
index a73a8d5a5e6..4aa2bb3b242 100644
--- a/arch/x86/include/asm/i387.h
+++ b/arch/x86/include/asm/i387.h
@@ -55,6 +55,12 @@ extern int save_i387_xstate_ia32(void __user *buf);
 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 @@ static __always_inline __pure bool use_xsave(void)
         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 @@ static inline void sanitize_i387_state(struct task_struct *tsk)
 }
 
 #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 @@ static inline int fxrstor_checking(struct i387_fxsave_struct *fx)
                      ".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 @@ static inline int fxsave_user(struct i387_fxsave_struct __user *fx)
         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 @@ 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() 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 @@ static inline void fpu_fxsave(struct fpu *fpu)
            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. */
-#if 0
+
+#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 @@ static inline int fxrstor_checking(struct i387_fxsave_struct *fx)
         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 int fxrstor_checking(struct i387_fxsave_struct *fx)
 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 @@ static inline void __save_init_fpu(struct task_struct *tsk)
         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 __unlazy_fpu(struct task_struct *tsk)
 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 @@ static inline void irq_ts_restore(int TS_state)
                 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 @@ static inline void clear_fpu(struct task_struct *tsk)
         preempt_enable();
 }
 
-#endif  /* CONFIG_X86_64 */
-
 /*
  * i387 state interaction
  */
@@ -508,7 +426,4 @@ extern void fpu_finit(struct fpu *fpu);
 
 #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 */