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Message-ID: <20120319165454.GA12831@gmail.com>
Date: Mon, 19 Mar 2012 17:54:54 +0100
From: Ingo Molnar <mingo@...nel.org>
To: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: linux-kernel@...r.kernel.org, "H. Peter Anvin" <hpa@...or.com>,
Thomas Gleixner <tglx@...utronix.de>,
Andrew Morton <akpm@...ux-foundation.org>
Subject: [GIT PULL] x86/fpu changes for v3.4
Linus,
Please pull the latest x86-fpu-for-linus git tree from:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-fpu-for-linus
HEAD: 1361b83a13d4d92e53fbb6c877528713e118b821 i387: Split up <asm/i387.h> into exported and internal interfaces
Thanks,
Ingo
------------------>
Linus Torvalds (2):
i387: Uninline the generic FP helpers that we expose to kernel modules
i387: Split up <asm/i387.h> into exported and internal interfaces
arch/x86/ia32/ia32_signal.c | 1 +
arch/x86/include/asm/fpu-internal.h | 520 ++++++++++++++++++++++++++++++
arch/x86/include/asm/i387.h | 590 +----------------------------------
arch/x86/kernel/cpu/common.c | 3 +-
arch/x86/kernel/i387.c | 83 +++++-
arch/x86/kernel/process.c | 1 +
arch/x86/kernel/process_32.c | 1 +
arch/x86/kernel/process_64.c | 1 +
arch/x86/kernel/ptrace.c | 1 +
arch/x86/kernel/signal.c | 1 +
arch/x86/kernel/traps.c | 1 +
arch/x86/kernel/xsave.c | 1 +
arch/x86/kvm/vmx.c | 2 +-
arch/x86/kvm/x86.c | 1 +
arch/x86/power/cpu.c | 1 +
15 files changed, 624 insertions(+), 584 deletions(-)
create mode 100644 arch/x86/include/asm/fpu-internal.h
diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
index 6557769..5563ba1 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 0000000..4fa8815
--- /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@...inux.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 2479049..7ce0798 100644
--- a/arch/x86/include/asm/i387.h
+++ b/arch/x86/include/asm/i387.h
@@ -13,476 +13,19 @@
#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 *);
+extern void math_state_restore(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);
- }
-}
-
-/*
- * Were we in an interrupt that interrupted kernel mode?
- *
- * We can do a kernel_fpu_begin/end() pair *ONLY* if that
- * pair does nothing at all: the thread must not have fpu (so
- * that we don't try to save the FPU state), and TS must
- * be set (so that the clts/stts pair does nothing that is
- * visible in the interrupted kernel thread).
- */
-static inline bool interrupted_kernel_fpu_idle(void)
-{
- return !__thread_has_fpu(current) &&
- (read_cr0() & X86_CR0_TS);
-}
-
-/*
- * Were we in user mode (or vm86 mode) when we were
- * interrupted?
- *
- * Doing kernel_fpu_begin/end() is ok if we are running
- * in an interrupt context from user mode - we'll just
- * save the FPU state as required.
- */
-static inline bool interrupted_user_mode(void)
-{
- struct pt_regs *regs = get_irq_regs();
- return regs && user_mode_vm(regs);
-}
-
-/*
- * Can we use the FPU in kernel mode with the
- * whole "kernel_fpu_begin/end()" sequence?
- *
- * It's always ok in process context (ie "not interrupt")
- * but it is sometimes ok even from an irq.
- */
-static inline bool irq_fpu_usable(void)
-{
- return !in_interrupt() ||
- interrupted_user_mode() ||
- interrupted_kernel_fpu_idle();
-}
-
-static inline void kernel_fpu_begin(void)
-{
- struct task_struct *me = current;
-
- WARN_ON_ONCE(!irq_fpu_usable());
- preempt_disable();
- if (__thread_has_fpu(me)) {
- __save_init_fpu(me);
- __thread_clear_has_fpu(me);
- /* We do 'stts()' in kernel_fpu_end() */
- } else {
- percpu_write(fpu_owner_task, NULL);
- clts();
- }
-}
-
-static inline void kernel_fpu_end(void)
-{
- stts();
- preempt_enable();
-}
+extern bool irq_fpu_usable(void);
+extern void kernel_fpu_begin(void);
+extern void kernel_fpu_end(void);
/*
* Some instructions like VIA's padlock instructions generate a spurious
@@ -524,126 +67,13 @@ 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();
-}
-
-static inline void unlazy_fpu(struct task_struct *tsk)
-{
- preempt_disable();
- if (__thread_has_fpu(tsk)) {
- __save_init_fpu(tsk);
- __thread_fpu_end(tsk);
- } else
- tsk->fpu_counter = 0;
- 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);
+ return current->thread.fpu.has_fpu;
}
-extern void fpu_finit(struct fpu *fpu);
+extern void unlazy_fpu(struct task_struct *tsk);
#endif /* __ASSEMBLY__ */
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index c0f7d68..89620b1 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>
@@ -1045,7 +1046,6 @@ DEFINE_PER_CPU(char *, irq_stack_ptr) =
DEFINE_PER_CPU(unsigned int, irq_count) = -1;
DEFINE_PER_CPU(struct task_struct *, fpu_owner_task);
-EXPORT_PER_CPU_SYMBOL(fpu_owner_task);
/*
* Special IST stacks which the CPU switches to when it calls
@@ -1115,7 +1115,6 @@ void debug_stack_reset(void)
DEFINE_PER_CPU(struct task_struct *, current_task) = &init_task;
EXPORT_PER_CPU_SYMBOL(current_task);
DEFINE_PER_CPU(struct task_struct *, fpu_owner_task);
-EXPORT_PER_CPU_SYMBOL(fpu_owner_task);
#ifdef CONFIG_CC_STACKPROTECTOR
DEFINE_PER_CPU_ALIGNED(struct stack_canary, stack_canary);
diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
index 739d859..7734bcb 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
@@ -32,6 +33,86 @@
# define user32_fxsr_struct user_fxsr_struct
#endif
+/*
+ * Were we in an interrupt that interrupted kernel mode?
+ *
+ * We can do a kernel_fpu_begin/end() pair *ONLY* if that
+ * pair does nothing at all: the thread must not have fpu (so
+ * that we don't try to save the FPU state), and TS must
+ * be set (so that the clts/stts pair does nothing that is
+ * visible in the interrupted kernel thread).
+ */
+static inline bool interrupted_kernel_fpu_idle(void)
+{
+ return !__thread_has_fpu(current) &&
+ (read_cr0() & X86_CR0_TS);
+}
+
+/*
+ * Were we in user mode (or vm86 mode) when we were
+ * interrupted?
+ *
+ * Doing kernel_fpu_begin/end() is ok if we are running
+ * in an interrupt context from user mode - we'll just
+ * save the FPU state as required.
+ */
+static inline bool interrupted_user_mode(void)
+{
+ struct pt_regs *regs = get_irq_regs();
+ return regs && user_mode_vm(regs);
+}
+
+/*
+ * Can we use the FPU in kernel mode with the
+ * whole "kernel_fpu_begin/end()" sequence?
+ *
+ * It's always ok in process context (ie "not interrupt")
+ * but it is sometimes ok even from an irq.
+ */
+bool irq_fpu_usable(void)
+{
+ return !in_interrupt() ||
+ interrupted_user_mode() ||
+ interrupted_kernel_fpu_idle();
+}
+EXPORT_SYMBOL(irq_fpu_usable);
+
+void kernel_fpu_begin(void)
+{
+ struct task_struct *me = current;
+
+ WARN_ON_ONCE(!irq_fpu_usable());
+ preempt_disable();
+ if (__thread_has_fpu(me)) {
+ __save_init_fpu(me);
+ __thread_clear_has_fpu(me);
+ /* We do 'stts()' in kernel_fpu_end() */
+ } else {
+ percpu_write(fpu_owner_task, NULL);
+ clts();
+ }
+}
+EXPORT_SYMBOL(kernel_fpu_begin);
+
+void kernel_fpu_end(void)
+{
+ stts();
+ preempt_enable();
+}
+EXPORT_SYMBOL(kernel_fpu_end);
+
+void unlazy_fpu(struct task_struct *tsk)
+{
+ preempt_disable();
+ if (__thread_has_fpu(tsk)) {
+ __save_init_fpu(tsk);
+ __thread_fpu_end(tsk);
+ } else
+ tsk->fpu_counter = 0;
+ preempt_enable();
+}
+EXPORT_SYMBOL(unlazy_fpu);
+
#ifdef CONFIG_MATH_EMULATION
# define HAVE_HWFP (boot_cpu_data.hard_math)
#else
@@ -44,7 +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 15763af..c38d84e 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 c08d1ff..ee32dee 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 cfa5c90..5bad3c7 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 5026738..78f05e4 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 46a01bd..25edcfc 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 4bbe04d..ec61d4c 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 7110911..e62728e 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 3b4c8d8..246490f 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 9cbfc06..b937b61 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 f10c0af..4889655 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;
--
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