[PATCH -mm 28/43] x86 i387 header cleanup
From: Roland McGrath
Date: Thu Dec 20 2007 - 07:13:04 EST
This moves some code into asm-x86/i387_64.h in preparation for
unifying this code between 32 and 64. The 32-bit versions of
some things are copied in some existing names changed to match
32-bit names and share code. For 64, save_i387 is moved into
an inline from i387_64.c; this matches restore_i387, which is
already an inline, and makes sense since there is exactly one
caller (in signal_64.c). The save_i387 function could use more
cosmetic cleanup, but it is just moved verbatim in this patch.
Signed-off-by: Roland McGrath <roland@xxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
arch/x86/kernel/i387_64.c | 31 -----
include/asm-x86/i387_64.h | 315 +++++++++++++++++++++++++++++++++------------
2 files changed, 233 insertions(+), 113 deletions(-)
diff --git a/arch/x86/kernel/i387_64.c b/arch/x86/kernel/i387_64.c
index bfaff28..f335a76 100644
--- a/arch/x86/kernel/i387_64.c
+++ b/arch/x86/kernel/i387_64.c
@@ -72,37 +72,6 @@ void init_fpu(struct task_struct *child)
}
/*
- * Signal frame handlers.
- */
-
-int save_i387(struct _fpstate __user *buf)
-{
- struct task_struct *tsk = current;
- int err = 0;
-
- BUILD_BUG_ON(sizeof(struct user_i387_struct) !=
- sizeof(tsk->thread.i387.fxsave));
-
- if ((unsigned long)buf % 16)
- printk("save_i387: bad fpstate %p\n",buf);
-
- if (!used_math())
- return 0;
- clear_used_math(); /* trigger finit */
- if (task_thread_info(tsk)->status & TS_USEDFPU) {
- err = save_i387_checking((struct i387_fxsave_struct __user *)buf);
- if (err) return err;
- task_thread_info(tsk)->status &= ~TS_USEDFPU;
- stts();
- } else {
- if (__copy_to_user(buf, &tsk->thread.i387.fxsave,
- sizeof(struct i387_fxsave_struct)))
- return -1;
- }
- return 1;
-}
-
-/*
* ptrace request handlers.
*/
diff --git a/include/asm-x86/i387_64.h b/include/asm-x86/i387_64.h
index 12edb9f..4cea737 100644
--- a/include/asm-x86/i387_64.h
+++ b/include/asm-x86/i387_64.h
@@ -7,33 +7,23 @@
* x86-64 work by Andi Kleen 2002
*/
-#ifndef __ASM_X86_64_I387_H
-#define __ASM_X86_64_I387_H
+#ifndef _ASM_X86_I387_H
+#define _ASM_X86_I387_H
#include <linux/sched.h>
+#include <linux/kernel_stat.h>
#include <asm/processor.h>
#include <asm/sigcontext.h>
#include <asm/user.h>
-#include <asm/thread_info.h>
#include <asm/uaccess.h>
extern void fpu_init(void);
extern unsigned int mxcsr_feature_mask;
extern void mxcsr_feature_mask_init(void);
extern void init_fpu(struct task_struct *child);
-extern int save_i387(struct _fpstate __user *buf);
extern asmlinkage void math_state_restore(void);
-/*
- * FPU lazy state save handling...
- */
-
-#define unlazy_fpu(tsk) do { \
- if (task_thread_info(tsk)->status & TS_USEDFPU) \
- save_init_fpu(tsk); \
- else \
- tsk->fpu_counter = 0; \
-} while (0)
+#ifdef CONFIG_X86_64
/* Ignore delayed exceptions from user space */
static inline void tolerant_fwait(void)
@@ -46,52 +36,8 @@ static inline void tolerant_fwait(void)
" .previous\n");
}
-#define clear_fpu(tsk) do { \
- if (task_thread_info(tsk)->status & TS_USEDFPU) { \
- tolerant_fwait(); \
- task_thread_info(tsk)->status &= ~TS_USEDFPU; \
- stts(); \
- } \
-} while (0)
-
-/*
- * ptrace request handers...
- */
-extern int get_fpregs(struct user_i387_struct __user *buf,
- struct task_struct *tsk);
-extern int set_fpregs(struct task_struct *tsk,
- struct user_i387_struct __user *buf);
-
-/*
- * i387 state interaction
- */
-#define get_fpu_mxcsr(t) ((t)->thread.i387.fxsave.mxcsr)
-#define get_fpu_cwd(t) ((t)->thread.i387.fxsave.cwd)
-#define get_fpu_fxsr_twd(t) ((t)->thread.i387.fxsave.twd)
-#define get_fpu_swd(t) ((t)->thread.i387.fxsave.swd)
-#define set_fpu_cwd(t,val) ((t)->thread.i387.fxsave.cwd = (val))
-#define set_fpu_swd(t,val) ((t)->thread.i387.fxsave.swd = (val))
-#define set_fpu_fxsr_twd(t,val) ((t)->thread.i387.fxsave.twd = (val))
-
-#define X87_FSW_ES (1 << 7) /* Exception Summary */
-
-/* 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 clear_fpu_state(struct i387_fxsave_struct *fx)
+static inline int restore_fpu_checking(struct i387_fxsave_struct *fx)
{
- 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 int restore_fpu_checking(struct i387_fxsave_struct *fx)
-{
int err;
asm volatile("1: rex64/fxrstor (%[fx])\n\t"
@@ -105,7 +51,7 @@ static inline int restore_fpu_checking(struct i387_fxsave_struct *fx)
" .quad 1b,3b\n"
".previous"
: [err] "=r" (err)
-#if 0 /* See comment in __fxsave_clear() below. */
+#if 0 /* See comment in __save_init_fpu() below. */
: [fx] "r" (fx), "m" (*fx), "0" (0));
#else
: [fx] "cdaSDb" (fx), "m" (*fx), "0" (0));
@@ -113,10 +59,27 @@ static inline int restore_fpu_checking(struct i387_fxsave_struct *fx)
if (unlikely(err))
init_fpu(current);
return err;
-}
+}
-static inline int save_i387_checking(struct i387_fxsave_struct __user *fx)
-{
+#define X87_FSW_ES (1 << 7) /* Exception Summary */
+
+/* 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 clear_fpu_state(struct i387_fxsave_struct *fx)
+{
+ 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 int save_i387_checking(struct i387_fxsave_struct __user *fx)
+{
int err;
asm volatile("1: rex64/fxsave (%[fx])\n\t"
@@ -139,9 +102,9 @@ static inline int save_i387_checking(struct i387_fxsave_struct __user *fx)
err = -EFAULT;
/* No need to clear here because the caller clears USED_MATH */
return err;
-}
+}
-static inline void __fxsave_clear(struct task_struct *tsk)
+static inline void __save_init_fpu(struct task_struct *tsk)
{
/* Using "rex64; fxsave %0" is broken because, if the memory operand
uses any extended registers for addressing, a second REX prefix
@@ -169,18 +132,142 @@ static inline void __fxsave_clear(struct task_struct *tsk)
thread.i387.fxsave)));
#endif
clear_fpu_state(&tsk->thread.i387.fxsave);
+ task_thread_info(tsk)->status &= ~TS_USEDFPU;
+}
+
+/*
+ * Signal frame handlers.
+ */
+
+static inline int save_i387(struct _fpstate __user *buf)
+{
+ struct task_struct *tsk = current;
+ int err = 0;
+
+ BUILD_BUG_ON(sizeof(struct user_i387_struct) !=
+ sizeof(tsk->thread.i387.fxsave));
+
+ if ((unsigned long)buf % 16)
+ printk("save_i387: bad fpstate %p\n", buf);
+
+ if (!used_math())
+ return 0;
+ clear_used_math(); /* trigger finit */
+ if (task_thread_info(tsk)->status & TS_USEDFPU) {
+ err = save_i387_checking((struct i387_fxsave_struct __user *)buf);
+ if (err) return err;
+ task_thread_info(tsk)->status &= ~TS_USEDFPU;
+ stts();
+ } else {
+ if (__copy_to_user(buf, &tsk->thread.i387.fxsave,
+ sizeof(struct i387_fxsave_struct)))
+ return -1;
+ }
+ return 1;
+}
+
+/*
+ * This restores directly out of user space. Exceptions are handled.
+ */
+static inline int restore_i387(struct _fpstate __user *buf)
+{
+ set_used_math();
+ if (!(task_thread_info(current)->status & TS_USEDFPU)) {
+ clts();
+ task_thread_info(current)->status |= TS_USEDFPU;
+ }
+ return restore_fpu_checking((__force struct i387_fxsave_struct *)buf);
+}
+
+#else /* CONFIG_X86_32 */
+
+static inline void tolerant_fwait(void)
+{
+ asm volatile("fnclex ; fwait");
+}
+
+static inline void restore_fpu(struct task_struct *tsk)
+{
+ /*
+ * The "nop" is needed to make the instructions the same
+ * length.
+ */
+ alternative_input(
+ "nop ; frstor %1",
+ "fxrstor %1",
+ X86_FEATURE_FXSR,
+ "m" ((tsk)->thread.i387.fxsave));
+}
+
+/* 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 */
+#ifdef CONFIG_SMP
+#define safe_address (__per_cpu_offset[0])
+#else
+#define safe_address (kstat_cpu(0).cpustat.user)
+#endif
+
+/*
+ * These must be called with preempt disabled
+ */
+static inline void __save_init_fpu(struct task_struct *tsk)
+{
+ /* 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" (tsk->thread.i387.fxsave),
+ [fsw] "m" (tsk->thread.i387.fxsave.swd) : "memory");
+ /* 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,
+ "emms\n\t" /* clear stack tags */
+ "fildl %[addr]", /* set F?P to defined value */
+ X86_FEATURE_FXSAVE_LEAK,
+ [addr] "m" (safe_address));
+ task_thread_info(tsk)->status &= ~TS_USEDFPU;
+}
+
+/*
+ * Signal frame handlers...
+ */
+extern int save_i387(struct _fpstate __user *buf);
+extern int restore_i387(struct _fpstate __user *buf);
+
+#endif /* CONFIG_X86_64 */
+
+static inline void __unlazy_fpu(struct task_struct *tsk)
+{
+ if (task_thread_info(tsk)->status & TS_USEDFPU) {
+ __save_init_fpu(tsk);
+ stts();
+ } else
+ tsk->fpu_counter = 0;
+}
+
+static inline void __clear_fpu(struct task_struct *tsk)
+{
+ if (task_thread_info(tsk)->status & TS_USEDFPU) {
+ tolerant_fwait();
+ task_thread_info(tsk)->status &= ~TS_USEDFPU;
+ stts();
+ }
}
static inline void kernel_fpu_begin(void)
{
struct thread_info *me = current_thread_info();
preempt_disable();
- if (me->status & TS_USEDFPU) {
- __fxsave_clear(me->task);
- me->status &= ~TS_USEDFPU;
- return;
- }
- clts();
+ if (me->status & TS_USEDFPU)
+ __save_init_fpu(me->task);
+ else
+ clts();
}
static inline void kernel_fpu_end(void)
@@ -189,24 +276,88 @@ static inline void kernel_fpu_end(void)
preempt_enable();
}
+#ifdef CONFIG_X86_64
+
static inline void save_init_fpu(struct task_struct *tsk)
{
- __fxsave_clear(tsk);
- task_thread_info(tsk)->status &= ~TS_USEDFPU;
+ __save_init_fpu(tsk);
stts();
}
-/*
- * This restores directly out of user space. Exceptions are handled.
+#define unlazy_fpu __unlazy_fpu
+#define clear_fpu __clear_fpu
+
+#else /* CONFIG_X86_32 */
+
+/*
+ * These disable preemption on their own and are safe
*/
-static inline int restore_i387(struct _fpstate __user *buf)
+static inline void save_init_fpu(struct task_struct *tsk)
{
- set_used_math();
- if (!(task_thread_info(current)->status & TS_USEDFPU)) {
- clts();
- task_thread_info(current)->status |= TS_USEDFPU;
+ preempt_disable();
+ __save_init_fpu(tsk);
+ stts();
+ preempt_enable();
+}
+
+static inline void unlazy_fpu(struct task_struct *tsk)
+{
+ preempt_disable();
+ __unlazy_fpu(tsk);
+ preempt_enable();
+}
+
+static inline void clear_fpu(struct task_struct *tsk)
+{
+ preempt_disable();
+ __clear_fpu(tsk);
+ preempt_enable();
+}
+
+#endif /* CONFIG_X86_64 */
+
+/*
+ * ptrace request handlers...
+ */
+extern int get_fpregs(struct user_i387_struct __user *buf,
+ struct task_struct *tsk);
+extern int set_fpregs(struct task_struct *tsk,
+ struct user_i387_struct __user *buf);
+
+struct user_fxsr_struct;
+extern int get_fpxregs(struct user_fxsr_struct __user *buf,
+ struct task_struct *tsk);
+extern int set_fpxregs(struct task_struct *tsk,
+ struct user_fxsr_struct __user *buf);
+
+/*
+ * i387 state interaction
+ */
+static inline unsigned short get_fpu_cwd(struct task_struct *tsk)
+{
+ if (cpu_has_fxsr) {
+ return tsk->thread.i387.fxsave.cwd;
+ } else {
+ return (unsigned short)tsk->thread.i387.fsave.cwd;
+ }
+}
+
+static inline unsigned short get_fpu_swd(struct task_struct *tsk)
+{
+ if (cpu_has_fxsr) {
+ return tsk->thread.i387.fxsave.swd;
+ } else {
+ return (unsigned short)tsk->thread.i387.fsave.swd;
+ }
+}
+
+static inline unsigned short get_fpu_mxcsr(struct task_struct *tsk)
+{
+ if (cpu_has_xmm) {
+ return tsk->thread.i387.fxsave.mxcsr;
+ } else {
+ return MXCSR_DEFAULT;
}
- return restore_fpu_checking((__force struct i387_fxsave_struct *)buf);
}
-#endif /* __ASM_X86_64_I387_H */
+#endif /* _ASM_X86_I387_H */
--
1.5.3.6
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