x86, fpu: Consolidate inline asm routines for saving/restoring fpu state

Consolidate x86, x86_64 inline asm routines saving/restoring fpu state
using config_enabled().

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Link: http://lkml.kernel.org/r/1343171129-2747-3-git-send-email-suresh.b.siddha@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

diff --git a/arch/x86/include/asm/fpu-internal.h b/arch/x86/include/asm/fpu-internal.h
index 6f595435ff9eb72c763860fb0a515ecb1fb822ff..016acb30fa4a470e2f19ee3db3ad5e126e3335a0 100644 (file)
--- a/arch/x86/include/asm/fpu-internal.h
+++ b/arch/x86/include/asm/fpu-internal.h
@@ -97,34 +97,24 @@ static inline void sanitize_i387_state(struct task_struct *tsk)
        __sanitize_i387_state(tsk);
 }
 
-#ifdef CONFIG_X86_64
-static inline int fxrstor_checking(struct i387_fxsave_struct *fx)
-{
-       int err;
-
-       /* See comment in fxsave() below. */
-#ifdef CONFIG_AS_FXSAVEQ
-       asm volatile("1:  fxrstorq %[fx]\n\t"
-                    "2:\n"
-                    ".section .fixup,\"ax\"\n"
-                    "3:  movl $-1,%[err]\n"
-                    "    jmp  2b\n"
-                    ".previous\n"
-                    _ASM_EXTABLE(1b, 3b)
-                    : [err] "=r" (err)
-                    : [fx] "m" (*fx), "0" (0));
-#else
-       asm volatile("1:  rex64/fxrstor (%[fx])\n\t"
-                    "2:\n"
-                    ".section .fixup,\"ax\"\n"
-                    "3:  movl $-1,%[err]\n"
-                    "    jmp  2b\n"
-                    ".previous\n"
-                    _ASM_EXTABLE(1b, 3b)
-                    : [err] "=r" (err)
-                    : [fx] "R" (fx), "m" (*fx), "0" (0));
-#endif
-       return err;
+#define check_insn(insn, output, input...)                             \
+({                                                                     \
+       int err;                                                        \
+       asm volatile("1:" #insn "\n\t"                                  \
+                    "2:\n"                                             \
+                    ".section .fixup,\"ax\"\n"                         \
+                    "3:  movl $-1,%[err]\n"                            \
+                    "    jmp  2b\n"                                    \
+                    ".previous\n"                                      \
+                    _ASM_EXTABLE(1b, 3b)                               \
+                    : [err] "=r" (err), output                         \
+                    : "0"(0), input);                                  \
+       err;                                                            \
+})
+
+static inline int fsave_user(struct i387_fsave_struct __user *fx)
+{
+       return check_insn(fnsave %[fx]; fwait,  [fx] "=m" (*fx), "m" (*fx));
 }
 
 static inline int fxsave_user(struct i387_fxsave_struct __user *fx)
@@ -140,90 +130,73 @@ static inline int fxsave_user(struct i387_fxsave_struct __user *fx)
        if (unlikely(err))
                return -EFAULT;
 
-       /* See comment in fxsave() below. */
-#ifdef CONFIG_AS_FXSAVEQ
-       asm volatile("1:  fxsaveq %[fx]\n\t"
-                    "2:\n"
-                    ".section .fixup,\"ax\"\n"
-                    "3:  movl $-1,%[err]\n"
-                    "    jmp  2b\n"
-                    ".previous\n"
-                    _ASM_EXTABLE(1b, 3b)
-                    : [err] "=r" (err), [fx] "=m" (*fx)
-                    : "0" (0));
-#else
-       asm volatile("1:  rex64/fxsave (%[fx])\n\t"
-                    "2:\n"
-                    ".section .fixup,\"ax\"\n"
-                    "3:  movl $-1,%[err]\n"
-                    "    jmp  2b\n"
-                    ".previous\n"
-                    _ASM_EXTABLE(1b, 3b)
-                    : [err] "=r" (err), "=m" (*fx)
-                    : [fx] "R" (fx), "0" (0));
-#endif
-       if (unlikely(err) &&
-           __clear_user(fx, sizeof(struct i387_fxsave_struct)))
-               err = -EFAULT;
-       /* No need to clear here because the caller clears USED_MATH */
-       return err;
+       if (config_enabled(CONFIG_X86_32))
+               return check_insn(fxsave %[fx], [fx] "=m" (*fx), "m" (*fx));
+       else if (config_enabled(CONFIG_AS_FXSAVEQ))
+               return check_insn(fxsaveq %[fx], [fx] "=m" (*fx), "m" (*fx));
+
+       /* See comment in fpu_fxsave() below. */
+       return check_insn(rex64/fxsave (%[fx]), "=m" (*fx), [fx] "R" (fx));
 }
 
-static inline void fpu_fxsave(struct fpu *fpu)
+static inline int fxrstor_checking(struct i387_fxsave_struct *fx)
 {
-       /* Using "rex64; fxsave %0" is broken because, if the memory operand
-          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 (config_enabled(CONFIG_X86_32))
+               return check_insn(fxrstor %[fx], "=m" (*fx), [fx] "m" (*fx));
+       else if (config_enabled(CONFIG_AS_FXSAVEQ))
+               return check_insn(fxrstorq %[fx], "=m" (*fx), [fx] "m" (*fx));
 
-#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));
-#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));
-          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 (%[fx])"
-                    : "=m" (fpu->state->fxsave)
-                    : [fx] "R" (&fpu->state->fxsave));
-#endif
+       /* See comment in fpu_fxsave() below. */
+       return check_insn(rex64/fxrstor (%[fx]), "=m" (*fx), [fx] "R" (fx),
+                         "m" (*fx));
 }
 
-int ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
-                       compat_sigset_t *set, struct pt_regs *regs);
-int ia32_setup_frame(int sig, struct k_sigaction *ka,
-                    compat_sigset_t *set, struct pt_regs *regs);
-
-#else  /* CONFIG_X86_32 */
-
-/* perform fxrstor iff the processor has extended states, otherwise frstor */
-static inline int fxrstor_checking(struct i387_fxsave_struct *fx)
+static inline int frstor_checking(struct i387_fsave_struct *fx)
 {
-       /*
-        * The "nop" is needed to make the instructions the same
-        * length.
-        */
-       alternative_input(
-               "nop ; frstor %1",
-               "fxrstor %1",
-               X86_FEATURE_FXSR,
-               "m" (*fx));
-
-       return 0;
+       return check_insn(frstor %[fx], "=m" (*fx), [fx] "m" (*fx));
 }
 
 static inline void fpu_fxsave(struct fpu *fpu)
 {
-       asm volatile("fxsave %[fx]"
-                    : [fx] "=m" (fpu->state->fxsave));
+       if (config_enabled(CONFIG_X86_32))
+               asm volatile( "fxsave %[fx]" : [fx] "=m" (fpu->state->fxsave));
+       else if (config_enabled(CONFIG_AS_FXSAVEQ))
+               asm volatile("fxsaveq %0" : "=m" (fpu->state->fxsave));
+       else {
+               /* Using "rex64; fxsave %0" is broken because, if the memory
+                * operand 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.
+                *
+                * Using "fxsaveq %0" would be the ideal choice, but is only
+                * supported starting with gas 2.16.
+                *
+                * 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));
+                *
+                * 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 (%[fx])"
+                            : "=m" (fpu->state->fxsave)
+                            : [fx] "R" (&fpu->state->fxsave));
+       }
 }
+#ifdef CONFIG_X86_64
+
+int ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
+                       compat_sigset_t *set, struct pt_regs *regs);
+int ia32_setup_frame(int sig, struct k_sigaction *ka,
+                    compat_sigset_t *set, struct pt_regs *regs);
+
+#else  /* CONFIG_X86_32 */
 
 #define ia32_setup_frame       __setup_frame
 #define ia32_setup_rt_frame    __setup_rt_frame
@@ -272,17 +245,14 @@ static inline int __save_init_fpu(struct task_struct *tsk)
        return fpu_save_init(&tsk->thread.fpu);
 }
 
-static inline int fpu_fxrstor_checking(struct fpu *fpu)
-{
-       return fxrstor_checking(&fpu->state->fxsave);
-}
-
 static inline int fpu_restore_checking(struct fpu *fpu)
 {
        if (use_xsave())
-               return fpu_xrstor_checking(fpu);
+               return fpu_xrstor_checking(&fpu->state->xsave);
+       else if (use_fxsr())
+               return fxrstor_checking(&fpu->state->fxsave);
        else
-               return fpu_fxrstor_checking(fpu);
+               return frstor_checking(&fpu->state->fsave);
 }
 
 static inline int restore_fpu_checking(struct task_struct *tsk)

diff --git a/arch/x86/include/asm/xsave.h b/arch/x86/include/asm/xsave.h
index 8a1b6f9b594a71bbf960635dc1dbfeb07eecbd52..aaac810e8613feb179a47c2986274fd5dd210896 100644 (file)
--- a/arch/x86/include/asm/xsave.h
+++ b/arch/x86/include/asm/xsave.h
@@ -42,9 +42,8 @@ extern int check_for_xstate(struct i387_fxsave_struct __user *buf,
                            void __user *fpstate,
                            struct _fpx_sw_bytes *sw);
 
-static inline int fpu_xrstor_checking(struct fpu *fpu)
+static inline int fpu_xrstor_checking(struct xsave_struct *fx)
 {
-       struct xsave_struct *fx = &fpu->state->xsave;
        int err;
 
        asm volatile("1: .byte " REX_PREFIX "0x0f,0xae,0x2f\n\t"
@@ -84,9 +83,6 @@ static inline int xsave_user(struct xsave_struct __user *buf)
                             : [err] "=r" (err)
                             : "D" (buf), "a" (-1), "d" (-1), "0" (0)
                             : "memory");
-       if (unlikely(err) && __clear_user(buf, xstate_size))
-               err = -EFAULT;
-       /* No need to clear here because the caller clears USED_MATH */
        return err;
 }
 

diff --git a/arch/x86/kernel/xsave.c b/arch/x86/kernel/xsave.c
index 9e1a8a7ba6e6f43b8c6479411ffbfb4468a3e6ae..7a3d4df9eaf6461b5201b00e81d1d0f577047166 100644 (file)
--- a/arch/x86/kernel/xsave.c
+++ b/arch/x86/kernel/xsave.c
@@ -176,8 +176,10 @@ int save_i387_xstate(void __user *buf)
                else
                        err = fxsave_user(buf);
 
-               if (err)
+               if (unlikely(err)) {
+                       __clear_user(buf, xstate_size);
                        return err;
+               }
                user_fpu_end();
        } else {
                sanitize_i387_state(tsk);