i387: Split up <asm/i387.h> into exported and internal interfaces

While various modules include <asm/i387.h> to get access to things we
actually *intend* for them to use, most of that header file was really
pretty low-level internal stuff that we really don't want to expose to
others.

So split the header file into two: the small exported interfaces remain
in <asm/i387.h>, while the internal definitions that are only used by
core architecture code are now in <asm/fpu-internal.h>.

The guiding principle for this was to expose functions that we export to
modules, and leave them in <asm/i387.h>, while stuff that is used by
task switching or was marked GPL-only is in <asm/fpu-internal.h>.

The fpu-internal.h file could be further split up too, especially since
arch/x86/kvm/ uses some of the remaining stuff for its module.  But that
kvm usage should probably be abstracted out a bit, and at least now the
internal FPU accessor functions are much more contained.  Even if it
isn't perhaps as contained as it _could_ be.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1202211340330.5354@i5.linux-foundation.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

15 files changed, 540 insertions, 508 deletions

diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
index 65577698cab2..5563ba1cf513 100644
--- a/arch/x86/ia32/ia32_signal.c
+++ b/arch/x86/ia32/ia32_signal.c
@@ -24,6 +24,7 @@
 #include <asm/ucontext.h>
 #include <asm/uaccess.h>
 #include <asm/i387.h>
+#include <asm/fpu-internal.h>
 #include <asm/ptrace.h>
 #include <asm/ia32_unistd.h>
 #include <asm/user32.h>
diff --git a/arch/x86/include/asm/fpu-internal.h b/arch/x86/include/asm/fpu-internal.h
new file mode 100644
index 000000000000..4fa88154e4de
--- /dev/null
+++ b/arch/x86/include/asm/fpu-internal.h
@@ -0,0 +1,520 @@
+/*
+ * Copyright (C) 1994 Linus Torvalds
+ *
+ * Pentium III FXSR, SSE support
+ * General FPU state handling cleanups
+ *      Gareth Hughes <gareth@valinux.com>, May 2000
+ * x86-64 work by Andi Kleen 2002
+ */
+
+#ifndef _FPU_INTERNAL_H
+#define _FPU_INTERNAL_H
+
+#include <linux/kernel_stat.h>
+#include <linux/regset.h>
+#include <linux/slab.h>
+#include <asm/asm.h>
+#include <asm/cpufeature.h>
+#include <asm/processor.h>
+#include <asm/sigcontext.h>
+#include <asm/user.h>
+#include <asm/uaccess.h>
+#include <asm/xsave.h>
+
+extern unsigned int sig_xstate_size;
+extern void fpu_init(void);
+
+DECLARE_PER_CPU(struct task_struct *, fpu_owner_task);
+
+extern user_regset_active_fn fpregs_active, xfpregs_active;
+extern user_regset_get_fn fpregs_get, xfpregs_get, fpregs_soft_get,
+                                xstateregs_get;
+extern user_regset_set_fn fpregs_set, xfpregs_set, fpregs_soft_set,
+                                 xstateregs_set;
+
+
+/*
+ * xstateregs_active == fpregs_active. Please refer to the comment
+ * at the definition of fpregs_active.
+ */
+#define xstateregs_active       fpregs_active
+
+extern struct _fpx_sw_bytes fx_sw_reserved;
+#ifdef CONFIG_IA32_EMULATION
+extern unsigned int sig_xstate_ia32_size;
+extern struct _fpx_sw_bytes fx_sw_reserved_ia32;
+struct _fpstate_ia32;
+struct _xstate_ia32;
+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)
+{
+        return static_cpu_has(X86_FEATURE_XSAVEOPT);
+}
+
+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)
+{
+        if (!use_xsaveopt())
+                return;
+        __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;
+}
+
+static inline int fxsave_user(struct i387_fxsave_struct __user *fx)
+{
+        int err;
+
+        /*
+         * Clear the bytes not touched by the fxsave and reserved
+         * for the SW usage.
+         */
+        err = __clear_user(&fx->sw_reserved,
+                           sizeof(struct _fpx_sw_bytes));
+        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;
+}
+
+static inline void fpu_fxsave(struct fpu *fpu)
+{
+        /* 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. */
+
+#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
+}
+
+#else  /* CONFIG_X86_32 */
+
+/* perform fxrstor iff the processor has extended states, otherwise frstor */
+static inline int fxrstor_checking(struct i387_fxsave_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;
+}
+
+static inline void fpu_fxsave(struct fpu *fpu)
+{
+        asm volatile("fxsave %[fx]"
+                     : [fx] "=m" (fpu->state->fxsave));
+}
+
+#endif  /* CONFIG_X86_64 */
+
+/*
+ * These must be called with preempt disabled. Returns
+ * 'true' if the FPU state is still intact.
+ */
+static inline int fpu_save_init(struct fpu *fpu)
+{
+        if (use_xsave()) {
+                fpu_xsave(fpu);
+
+                /*
+                 * xsave header may indicate the init state of the FP.
+                 */
+                if (!(fpu->state->xsave.xsave_hdr.xstate_bv & XSTATE_FP))
+                        return 1;
+        } else if (use_fxsr()) {
+                fpu_fxsave(fpu);
+        } else {
+                asm volatile("fnsave %[fx]; fwait"
+                             : [fx] "=m" (fpu->state->fsave));
+                return 0;
+        }
+
+        /*
+         * If exceptions are pending, we need to clear them so
+         * that we don't randomly get exceptions later.
+         *
+         * FIXME! Is this perhaps only true for the old-style
+         * irq13 case? Maybe we could leave the x87 state
+         * intact otherwise?
+         */
+        if (unlikely(fpu->state->fxsave.swd & X87_FSW_ES)) {
+                asm volatile("fnclex");
+                return 0;
+        }
+        return 1;
+}
+
+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);
+        else
+                return fpu_fxrstor_checking(fpu);
+}
+
+static inline int restore_fpu_checking(struct task_struct *tsk)
+{
+        /* 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. "m" is a random variable that should be in L1 */
+        alternative_input(
+                ASM_NOP8 ASM_NOP2,
+                "emms\n\t"              /* clear stack tags */
+                "fildl %P[addr]",       /* set F?P to defined value */
+                X86_FEATURE_FXSAVE_LEAK,
+                [addr] "m" (tsk->thread.fpu.has_fpu));
+
+        return fpu_restore_checking(&tsk->thread.fpu);
+}
+
+/*
+ * Software FPU state helpers. Careful: these need to
+ * be preemption protection *and* they need to be
+ * properly paired with the CR0.TS changes!
+ */
+static inline int __thread_has_fpu(struct task_struct *tsk)
+{
+        return tsk->thread.fpu.has_fpu;
+}
+
+/* Must be paired with an 'stts' after! */
+static inline void __thread_clear_has_fpu(struct task_struct *tsk)
+{
+        tsk->thread.fpu.has_fpu = 0;
+        percpu_write(fpu_owner_task, NULL);
+}
+
+/* Must be paired with a 'clts' before! */
+static inline void __thread_set_has_fpu(struct task_struct *tsk)
+{
+        tsk->thread.fpu.has_fpu = 1;
+        percpu_write(fpu_owner_task, tsk);
+}
+
+/*
+ * Encapsulate the CR0.TS handling together with the
+ * software flag.
+ *
+ * These generally need preemption protection to work,
+ * do try to avoid using these on their own.
+ */
+static inline void __thread_fpu_end(struct task_struct *tsk)
+{
+        __thread_clear_has_fpu(tsk);
+        stts();
+}
+
+static inline void __thread_fpu_begin(struct task_struct *tsk)
+{
+        clts();
+        __thread_set_has_fpu(tsk);
+}
+
+/*
+ * FPU state switching for scheduling.
+ *
+ * This is a two-stage process:
+ *
+ *  - switch_fpu_prepare() saves the old state and
+ *    sets the new state of the CR0.TS bit. This is
+ *    done within the context of the old process.
+ *
+ *  - switch_fpu_finish() restores the new state as
+ *    necessary.
+ */
+typedef struct { int preload; } fpu_switch_t;
+
+/*
+ * FIXME! We could do a totally lazy restore, but we need to
+ * add a per-cpu "this was the task that last touched the FPU
+ * on this CPU" variable, and the task needs to have a "I last
+ * touched the FPU on this CPU" and check them.
+ *
+ * We don't do that yet, so "fpu_lazy_restore()" always returns
+ * false, but some day..
+ */
+static inline int fpu_lazy_restore(struct task_struct *new, unsigned int cpu)
+{
+        return new == percpu_read_stable(fpu_owner_task) &&
+                cpu == new->thread.fpu.last_cpu;
+}
+
+static inline fpu_switch_t switch_fpu_prepare(struct task_struct *old, struct task_struct *new, int cpu)
+{
+        fpu_switch_t fpu;
+
+        fpu.preload = tsk_used_math(new) && new->fpu_counter > 5;
+        if (__thread_has_fpu(old)) {
+                if (!__save_init_fpu(old))
+                        cpu = ~0;
+                old->thread.fpu.last_cpu = cpu;
+                old->thread.fpu.has_fpu = 0;    /* But leave fpu_owner_task! */
+
+                /* Don't change CR0.TS if we just switch! */
+                if (fpu.preload) {
+                        new->fpu_counter++;
+                        __thread_set_has_fpu(new);
+                        prefetch(new->thread.fpu.state);
+                } else
+                        stts();
+        } else {
+                old->fpu_counter = 0;
+                old->thread.fpu.last_cpu = ~0;
+                if (fpu.preload) {
+                        new->fpu_counter++;
+                        if (fpu_lazy_restore(new, cpu))
+                                fpu.preload = 0;
+                        else
+                                prefetch(new->thread.fpu.state);
+                        __thread_fpu_begin(new);
+                }
+        }
+        return fpu;
+}
+
+/*
+ * By the time this gets called, we've already cleared CR0.TS and
+ * given the process the FPU if we are going to preload the FPU
+ * state - all we need to do is to conditionally restore the register
+ * state itself.
+ */
+static inline void switch_fpu_finish(struct task_struct *new, fpu_switch_t fpu)
+{
+        if (fpu.preload) {
+                if (unlikely(restore_fpu_checking(new)))
+                        __thread_fpu_end(new);
+        }
+}
+
+/*
+ * Signal frame handlers...
+ */
+extern int save_i387_xstate(void __user *buf);
+extern int restore_i387_xstate(void __user *buf);
+
+static inline void __clear_fpu(struct task_struct *tsk)
+{
+        if (__thread_has_fpu(tsk)) {
+                /* Ignore delayed exceptions from user space */
+                asm volatile("1: fwait\n"
+                             "2:\n"
+                             _ASM_EXTABLE(1b, 2b));
+                __thread_fpu_end(tsk);
+        }
+}
+
+/*
+ * The actual user_fpu_begin/end() functions
+ * need to be preemption-safe.
+ *
+ * NOTE! user_fpu_end() must be used only after you
+ * have saved the FP state, and user_fpu_begin() must
+ * be used only immediately before restoring it.
+ * These functions do not do any save/restore on
+ * their own.
+ */
+static inline void user_fpu_end(void)
+{
+        preempt_disable();
+        __thread_fpu_end(current);
+        preempt_enable();
+}
+
+static inline void user_fpu_begin(void)
+{
+        preempt_disable();
+        if (!user_has_fpu())
+                __thread_fpu_begin(current);
+        preempt_enable();
+}
+
+/*
+ * These disable preemption on their own and are safe
+ */
+static inline void save_init_fpu(struct task_struct *tsk)
+{
+        WARN_ON_ONCE(!__thread_has_fpu(tsk));
+        preempt_disable();
+        __save_init_fpu(tsk);
+        __thread_fpu_end(tsk);
+        preempt_enable();
+}
+
+static inline void clear_fpu(struct task_struct *tsk)
+{
+        preempt_disable();
+        __clear_fpu(tsk);
+        preempt_enable();
+}
+
+/*
+ * i387 state interaction
+ */
+static inline unsigned short get_fpu_cwd(struct task_struct *tsk)
+{
+        if (cpu_has_fxsr) {
+                return tsk->thread.fpu.state->fxsave.cwd;
+        } else {
+                return (unsigned short)tsk->thread.fpu.state->fsave.cwd;
+        }
+}
+
+static inline unsigned short get_fpu_swd(struct task_struct *tsk)
+{
+        if (cpu_has_fxsr) {
+                return tsk->thread.fpu.state->fxsave.swd;
+        } else {
+                return (unsigned short)tsk->thread.fpu.state->fsave.swd;
+        }
+}
+
+static inline unsigned short get_fpu_mxcsr(struct task_struct *tsk)
+{
+        if (cpu_has_xmm) {
+                return tsk->thread.fpu.state->fxsave.mxcsr;
+        } else {
+                return MXCSR_DEFAULT;
+        }
+}
+
+static bool fpu_allocated(struct fpu *fpu)
+{
+        return fpu->state != NULL;
+}
+
+static inline int fpu_alloc(struct fpu *fpu)
+{
+        if (fpu_allocated(fpu))
+                return 0;
+        fpu->state = kmem_cache_alloc(task_xstate_cachep, GFP_KERNEL);
+        if (!fpu->state)
+                return -ENOMEM;
+        WARN_ON((unsigned long)fpu->state & 15);
+        return 0;
+}
+
+static inline void fpu_free(struct fpu *fpu)
+{
+        if (fpu->state) {
+                kmem_cache_free(task_xstate_cachep, fpu->state);
+                fpu->state = NULL;
+        }
+}
+
+static inline void fpu_copy(struct fpu *dst, struct fpu *src)
+{
+        memcpy(dst->state, src->state, xstate_size);
+}
+
+extern void fpu_finit(struct fpu *fpu);
+
+#endif
diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h
index 0c1031d354f2..7ce0798b1b26 100644
--- a/arch/x86/include/asm/i387.h
+++ b/arch/x86/include/asm/i387.h
@@ -13,411 +13,15 @@
 #ifndef __ASSEMBLY__
 
 #include <linux/sched.h>
-#include <linux/kernel_stat.h>
-#include <linux/regset.h>
 #include <linux/hardirq.h>
-#include <linux/slab.h>
-#include <asm/asm.h>
-#include <asm/cpufeature.h>
-#include <asm/processor.h>
-#include <asm/sigcontext.h>
-#include <asm/user.h>
-#include <asm/uaccess.h>
-#include <asm/xsave.h>
+#include <asm/system.h>
+
+struct pt_regs;
+struct user_i387_struct;
 
-extern unsigned int sig_xstate_size;
-extern void fpu_init(void);
-extern void mxcsr_feature_mask_init(void);
 extern int init_fpu(struct task_struct *child);
-extern void math_state_restore(void);
 extern int dump_fpu(struct pt_regs *, struct user_i387_struct *);
-
-DECLARE_PER_CPU(struct task_struct *, fpu_owner_task);
-
-extern user_regset_active_fn fpregs_active, xfpregs_active;
-extern user_regset_get_fn fpregs_get, xfpregs_get, fpregs_soft_get,
-                                xstateregs_get;
-extern user_regset_set_fn fpregs_set, xfpregs_set, fpregs_soft_set,
-                                 xstateregs_set;
-
-/*
- * xstateregs_active == fpregs_active. Please refer to the comment
- * at the definition of fpregs_active.
- */
-#define xstateregs_active       fpregs_active
-
-extern struct _fpx_sw_bytes fx_sw_reserved;
-#ifdef CONFIG_IA32_EMULATION
-extern unsigned int sig_xstate_ia32_size;
-extern struct _fpx_sw_bytes fx_sw_reserved_ia32;
-struct _fpstate_ia32;
-struct _xstate_ia32;
-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)
-{
-        return static_cpu_has(X86_FEATURE_XSAVEOPT);
-}
-
-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)
-{
-        if (!use_xsaveopt())
-                return;
-        __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;
-}
-
-static inline int fxsave_user(struct i387_fxsave_struct __user *fx)
-{
-        int err;
-
-        /*
-         * Clear the bytes not touched by the fxsave and reserved
-         * for the SW usage.
-         */
-        err = __clear_user(&fx->sw_reserved,
-                           sizeof(struct _fpx_sw_bytes));
-        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;
-}
-
-static inline void fpu_fxsave(struct fpu *fpu)
-{
-        /* 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. */
-
-#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
-}
-
-#else  /* CONFIG_X86_32 */
-
-/* perform fxrstor iff the processor has extended states, otherwise frstor */
-static inline int fxrstor_checking(struct i387_fxsave_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;
-}
-
-static inline void fpu_fxsave(struct fpu *fpu)
-{
-        asm volatile("fxsave %[fx]"
-                     : [fx] "=m" (fpu->state->fxsave));
-}
-
-#endif  /* CONFIG_X86_64 */
-
-/*
- * These must be called with preempt disabled. Returns
- * 'true' if the FPU state is still intact.
- */
-static inline int fpu_save_init(struct fpu *fpu)
-{
-        if (use_xsave()) {
-                fpu_xsave(fpu);
-
-                /*
-                 * xsave header may indicate the init state of the FP.
-                 */
-                if (!(fpu->state->xsave.xsave_hdr.xstate_bv & XSTATE_FP))
-                        return 1;
-        } else if (use_fxsr()) {
-                fpu_fxsave(fpu);
-        } else {
-                asm volatile("fnsave %[fx]; fwait"
-                             : [fx] "=m" (fpu->state->fsave));
-                return 0;
-        }
-
-        /*
-         * If exceptions are pending, we need to clear them so
-         * that we don't randomly get exceptions later.
-         *
-         * FIXME! Is this perhaps only true for the old-style
-         * irq13 case? Maybe we could leave the x87 state
-         * intact otherwise?
-         */
-        if (unlikely(fpu->state->fxsave.swd & X87_FSW_ES)) {
-                asm volatile("fnclex");
-                return 0;
-        }
-        return 1;
-}
-
-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);
-        else
-                return fpu_fxrstor_checking(fpu);
-}
-
-static inline int restore_fpu_checking(struct task_struct *tsk)
-{
-        /* 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. "m" is a random variable that should be in L1 */
-        alternative_input(
-                ASM_NOP8 ASM_NOP2,
-                "emms\n\t"              /* clear stack tags */
-                "fildl %P[addr]",       /* set F?P to defined value */
-                X86_FEATURE_FXSAVE_LEAK,
-                [addr] "m" (tsk->thread.fpu.has_fpu));
-
-        return fpu_restore_checking(&tsk->thread.fpu);
-}
-
-/*
- * Software FPU state helpers. Careful: these need to
- * be preemption protection *and* they need to be
- * properly paired with the CR0.TS changes!
- */
-static inline int __thread_has_fpu(struct task_struct *tsk)
-{
-        return tsk->thread.fpu.has_fpu;
-}
-
-/* Must be paired with an 'stts' after! */
-static inline void __thread_clear_has_fpu(struct task_struct *tsk)
-{
-        tsk->thread.fpu.has_fpu = 0;
-        percpu_write(fpu_owner_task, NULL);
-}
-
-/* Must be paired with a 'clts' before! */
-static inline void __thread_set_has_fpu(struct task_struct *tsk)
-{
-        tsk->thread.fpu.has_fpu = 1;
-        percpu_write(fpu_owner_task, tsk);
-}
-
-/*
- * Encapsulate the CR0.TS handling together with the
- * software flag.
- *
- * These generally need preemption protection to work,
- * do try to avoid using these on their own.
- */
-static inline void __thread_fpu_end(struct task_struct *tsk)
-{
-        __thread_clear_has_fpu(tsk);
-        stts();
-}
-
-static inline void __thread_fpu_begin(struct task_struct *tsk)
-{
-        clts();
-        __thread_set_has_fpu(tsk);
-}
-
-/*
- * FPU state switching for scheduling.
- *
- * This is a two-stage process:
- *
- *  - switch_fpu_prepare() saves the old state and
- *    sets the new state of the CR0.TS bit. This is
- *    done within the context of the old process.
- *
- *  - switch_fpu_finish() restores the new state as
- *    necessary.
- */
-typedef struct { int preload; } fpu_switch_t;
-
-/*
- * FIXME! We could do a totally lazy restore, but we need to
- * add a per-cpu "this was the task that last touched the FPU
- * on this CPU" variable, and the task needs to have a "I last
- * touched the FPU on this CPU" and check them.
- *
- * We don't do that yet, so "fpu_lazy_restore()" always returns
- * false, but some day..
- */
-static inline int fpu_lazy_restore(struct task_struct *new, unsigned int cpu)
-{
-        return new == percpu_read_stable(fpu_owner_task) &&
-                cpu == new->thread.fpu.last_cpu;
-}
-
-static inline fpu_switch_t switch_fpu_prepare(struct task_struct *old, struct task_struct *new, int cpu)
-{
-        fpu_switch_t fpu;
-
-        fpu.preload = tsk_used_math(new) && new->fpu_counter > 5;
-        if (__thread_has_fpu(old)) {
-                if (!__save_init_fpu(old))
-                        cpu = ~0;
-                old->thread.fpu.last_cpu = cpu;
-                old->thread.fpu.has_fpu = 0;    /* But leave fpu_owner_task! */
-
-                /* Don't change CR0.TS if we just switch! */
-                if (fpu.preload) {
-                        new->fpu_counter++;
-                        __thread_set_has_fpu(new);
-                        prefetch(new->thread.fpu.state);
-                } else
-                        stts();
-        } else {
-                old->fpu_counter = 0;
-                old->thread.fpu.last_cpu = ~0;
-                if (fpu.preload) {
-                        new->fpu_counter++;
-                        if (fpu_lazy_restore(new, cpu))
-                                fpu.preload = 0;
-                        else
-                                prefetch(new->thread.fpu.state);
-                        __thread_fpu_begin(new);
-                }
-        }
-        return fpu;
-}
-
-/*
- * By the time this gets called, we've already cleared CR0.TS and
- * given the process the FPU if we are going to preload the FPU
- * state - all we need to do is to conditionally restore the register
- * state itself.
- */
-static inline void switch_fpu_finish(struct task_struct *new, fpu_switch_t fpu)
-{
-        if (fpu.preload) {
-                if (unlikely(restore_fpu_checking(new)))
-                        __thread_fpu_end(new);
-        }
-}
-
-/*
- * Signal frame handlers...
- */
-extern int save_i387_xstate(void __user *buf);
-extern int restore_i387_xstate(void __user *buf);
-
-static inline void __clear_fpu(struct task_struct *tsk)
-{
-        if (__thread_has_fpu(tsk)) {
-                /* Ignore delayed exceptions from user space */
-                asm volatile("1: fwait\n"
-                             "2:\n"
-                             _ASM_EXTABLE(1b, 2b));
-                __thread_fpu_end(tsk);
-        }
-}
+extern void math_state_restore(void);
 
 extern bool irq_fpu_usable(void);
 extern void kernel_fpu_begin(void);
@@ -463,118 +67,14 @@ static inline void irq_ts_restore(int TS_state)
  * we can just assume we have FPU access - typically
  * to save the FP state - we'll just take a #NM
  * fault and get the FPU access back.
- *
- * The actual user_fpu_begin/end() functions
- * need to be preemption-safe, though.
- *
- * NOTE! user_fpu_end() must be used only after you
- * have saved the FP state, and user_fpu_begin() must
- * be used only immediately before restoring it.
- * These functions do not do any save/restore on
- * their own.
  */
 static inline int user_has_fpu(void)
 {
-        return __thread_has_fpu(current);
-}
-
-static inline void user_fpu_end(void)
-{
-        preempt_disable();
-        __thread_fpu_end(current);
-        preempt_enable();
-}
-
-static inline void user_fpu_begin(void)
-{
-        preempt_disable();
-        if (!user_has_fpu())
-                __thread_fpu_begin(current);
-        preempt_enable();
-}
-
-/*
- * These disable preemption on their own and are safe
- */
-static inline void save_init_fpu(struct task_struct *tsk)
-{
-        WARN_ON_ONCE(!__thread_has_fpu(tsk));
-        preempt_disable();
-        __save_init_fpu(tsk);
-        __thread_fpu_end(tsk);
-        preempt_enable();
+        return current->thread.fpu.has_fpu;
 }
 
 extern void unlazy_fpu(struct task_struct *tsk);
 
-static inline void clear_fpu(struct task_struct *tsk)
-{
-        preempt_disable();
-        __clear_fpu(tsk);
-        preempt_enable();
-}
-
-/*
- * i387 state interaction
- */
-static inline unsigned short get_fpu_cwd(struct task_struct *tsk)
-{
-        if (cpu_has_fxsr) {
-                return tsk->thread.fpu.state->fxsave.cwd;
-        } else {
-                return (unsigned short)tsk->thread.fpu.state->fsave.cwd;
-        }
-}
-
-static inline unsigned short get_fpu_swd(struct task_struct *tsk)
-{
-        if (cpu_has_fxsr) {
-                return tsk->thread.fpu.state->fxsave.swd;
-        } else {
-                return (unsigned short)tsk->thread.fpu.state->fsave.swd;
-        }
-}
-
-static inline unsigned short get_fpu_mxcsr(struct task_struct *tsk)
-{
-        if (cpu_has_xmm) {
-                return tsk->thread.fpu.state->fxsave.mxcsr;
-        } else {
-                return MXCSR_DEFAULT;
-        }
-}
-
-static bool fpu_allocated(struct fpu *fpu)
-{
-        return fpu->state != NULL;
-}
-
-static inline int fpu_alloc(struct fpu *fpu)
-{
-        if (fpu_allocated(fpu))
-                return 0;
-        fpu->state = kmem_cache_alloc(task_xstate_cachep, GFP_KERNEL);
-        if (!fpu->state)
-                return -ENOMEM;
-        WARN_ON((unsigned long)fpu->state & 15);
-        return 0;
-}
-
-static inline void fpu_free(struct fpu *fpu)
-{
-        if (fpu->state) {
-                kmem_cache_free(task_xstate_cachep, fpu->state);
-                fpu->state = NULL;
-        }
-}
-
-static inline void fpu_copy(struct fpu *dst, struct fpu *src)
-{
-        memcpy(dst->state, src->state, xstate_size);
-}
-
-extern void fpu_finit(struct fpu *fpu);
-
 #endif /* __ASSEMBLY__ */
 
 #endif /* _ASM_X86_I387_H */
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index cb71b01ab66e..89620b1725d4 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -28,6 +28,7 @@
 #include <asm/apic.h>
 #include <asm/desc.h>
 #include <asm/i387.h>
+#include <asm/fpu-internal.h>
 #include <asm/mtrr.h>
 #include <linux/numa.h>
 #include <asm/asm.h>
diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
index 17b7549c4134..7734bcbb5a3a 100644
--- a/arch/x86/kernel/i387.c
+++ b/arch/x86/kernel/i387.c
@@ -16,6 +16,7 @@
 #include <asm/uaccess.h>
 #include <asm/ptrace.h>
 #include <asm/i387.h>
+#include <asm/fpu-internal.h>
 #include <asm/user.h>
 
 #ifdef CONFIG_X86_64
@@ -124,7 +125,7 @@ EXPORT_SYMBOL_GPL(xstate_size);
 unsigned int sig_xstate_ia32_size = sizeof(struct _fpstate_ia32);
 static struct i387_fxsave_struct fx_scratch __cpuinitdata;
 
-void __cpuinit mxcsr_feature_mask_init(void)
+static void __cpuinit mxcsr_feature_mask_init(void)
 {
         unsigned long mask = 0;
 
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 15763af7bfe3..c38d84e01022 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -21,6 +21,7 @@
 #include <asm/idle.h>
 #include <asm/uaccess.h>
 #include <asm/i387.h>
+#include <asm/fpu-internal.h>
 #include <asm/debugreg.h>
 
 struct kmem_cache *task_xstate_cachep;
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index c08d1ff12b7c..ee32dee7a0a3 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -45,6 +45,7 @@
 #include <asm/ldt.h>
 #include <asm/processor.h>
 #include <asm/i387.h>
+#include <asm/fpu-internal.h>
 #include <asm/desc.h>
 #ifdef CONFIG_MATH_EMULATION
 #include <asm/math_emu.h>
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index cfa5c90c01db..5bad3c71e48f 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -43,6 +43,7 @@
 #include <asm/system.h>
 #include <asm/processor.h>
 #include <asm/i387.h>
+#include <asm/fpu-internal.h>
 #include <asm/mmu_context.h>
 #include <asm/prctl.h>
 #include <asm/desc.h>
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 50267386b766..78f05e438be5 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -27,6 +27,7 @@
 #include <asm/system.h>
 #include <asm/processor.h>
 #include <asm/i387.h>
+#include <asm/fpu-internal.h>
 #include <asm/debugreg.h>
 #include <asm/ldt.h>
 #include <asm/desc.h>
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 46a01bdc27e2..25edcfc9ba5b 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -24,6 +24,7 @@
 #include <asm/processor.h>
 #include <asm/ucontext.h>
 #include <asm/i387.h>
+#include <asm/fpu-internal.h>
 #include <asm/vdso.h>
 #include <asm/mce.h>
 
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 4bbe04d96744..ec61d4c1b93b 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -54,6 +54,7 @@
 #include <asm/traps.h>
 #include <asm/desc.h>
 #include <asm/i387.h>
+#include <asm/fpu-internal.h>
 #include <asm/mce.h>
 
 #include <asm/mach_traps.h>
diff --git a/arch/x86/kernel/xsave.c b/arch/x86/kernel/xsave.c
index 711091114119..e62728e30b01 100644
--- a/arch/x86/kernel/xsave.c
+++ b/arch/x86/kernel/xsave.c
@@ -6,6 +6,7 @@
 #include <linux/bootmem.h>
 #include <linux/compat.h>
 #include <asm/i387.h>
+#include <asm/fpu-internal.h>
 #ifdef CONFIG_IA32_EMULATION
 #include <asm/sigcontext32.h>
 #endif
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 3b4c8d8ad906..246490f643b6 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1457,7 +1457,7 @@ static void __vmx_load_host_state(struct vcpu_vmx *vmx)
 #ifdef CONFIG_X86_64
         wrmsrl(MSR_KERNEL_GS_BASE, vmx->msr_host_kernel_gs_base);
 #endif
-        if (__thread_has_fpu(current))
+        if (user_has_fpu())
                 clts();
         load_gdt(&__get_cpu_var(host_gdt));
 }
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 9cbfc0698118..b937b6179d80 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -57,6 +57,7 @@
 #include <asm/mtrr.h>
 #include <asm/mce.h>
 #include <asm/i387.h>
+#include <asm/fpu-internal.h> /* Ugh! */
 #include <asm/xcr.h>
 #include <asm/pvclock.h>
 #include <asm/div64.h>
diff --git a/arch/x86/power/cpu.c b/arch/x86/power/cpu.c
index f10c0afa1cb4..4889655ba784 100644
--- a/arch/x86/power/cpu.c
+++ b/arch/x86/power/cpu.c
@@ -20,6 +20,7 @@
 #include <asm/xcr.h>
 #include <asm/suspend.h>
 #include <asm/debugreg.h>
+#include <asm/fpu-internal.h> /* pcntxt_mask */
 
 #ifdef CONFIG_X86_32
 static struct saved_context saved_context;