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x86: x86 i387 header cleanup

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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@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Roland McGrath 2008-01-30 13:31:49 +01:00 committed by Ingo Molnar
parent 99f8ecdf45
commit cc927a25bd
2 changed files with 242 additions and 122 deletions
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31
arch/x86/kernel/i387_64.c
View file

@ -71,37 +71,6 @@ void init_fpu(struct task_struct *child)
set_stopped_child_used_math(child); set_stopped_child_used_math(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. * ptrace request handlers.
*/ */

333
include/asm-x86/i387_64.h
View file

@ -7,33 +7,23 @@
* x86-64 work by Andi Kleen 2002 * x86-64 work by Andi Kleen 2002
*/ */
#ifndef __ASM_X86_64_I387_H #ifndef _ASM_X86_I387_H
#define __ASM_X86_64_I387_H #define _ASM_X86_I387_H
#include <linux/sched.h> #include <linux/sched.h>
#include <linux/kernel_stat.h>
#include <asm/processor.h> #include <asm/processor.h>
#include <asm/sigcontext.h> #include <asm/sigcontext.h>
#include <asm/user.h> #include <asm/user.h>
#include <asm/thread_info.h>
#include <asm/uaccess.h> #include <asm/uaccess.h>
extern void fpu_init(void); extern void fpu_init(void);
extern unsigned int mxcsr_feature_mask; extern unsigned int mxcsr_feature_mask;
extern void mxcsr_feature_mask_init(void); extern void mxcsr_feature_mask_init(void);
extern void init_fpu(struct task_struct *child); extern void init_fpu(struct task_struct *child);
extern int save_i387(struct _fpstate __user *buf);
extern asmlinkage void math_state_restore(void); extern asmlinkage void math_state_restore(void);
/* #ifdef CONFIG_X86_64
* 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)
/* Ignore delayed exceptions from user space */ /* Ignore delayed exceptions from user space */
static inline void tolerant_fwait(void) static inline void tolerant_fwait(void)
@ -46,52 +36,8 @@ static inline void tolerant_fwait(void)
" .previous\n"); " .previous\n");
} }
#define clear_fpu(tsk) do { \ static inline int restore_fpu_checking(struct i387_fxsave_struct *fx)
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)
{ {
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; int err;
asm volatile("1: rex64/fxrstor (%[fx])\n\t" 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" " .quad 1b,3b\n"
".previous" ".previous"
: [err] "=r" (err) : [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)); : [fx] "r" (fx), "m" (*fx), "0" (0));
#else #else
: [fx] "cdaSDb" (fx), "m" (*fx), "0" (0)); : [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)) if (unlikely(err))
init_fpu(current); init_fpu(current);
return err; 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; int err;
asm volatile("1: rex64/fxsave (%[fx])\n\t" 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; err = -EFAULT;
/* No need to clear here because the caller clears USED_MATH */ /* No need to clear here because the caller clears USED_MATH */
return err; 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 /* Using "rex64; fxsave %0" is broken because, if the memory operand
uses any extended registers for addressing, a second REX prefix uses any extended registers for addressing, a second REX prefix
@ -169,34 +132,41 @@ static inline void __fxsave_clear(struct task_struct *tsk)
thread.i387.fxsave))); thread.i387.fxsave)));
#endif #endif
clear_fpu_state(&tsk->thread.i387.fxsave); clear_fpu_state(&tsk->thread.i387.fxsave);
}
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();
}
static inline void kernel_fpu_end(void)
{
stts();
preempt_enable();
}
static inline void save_init_fpu(struct task_struct *tsk)
{
__fxsave_clear(tsk);
task_thread_info(tsk)->status &= ~TS_USEDFPU; task_thread_info(tsk)->status &= ~TS_USEDFPU;
stts();
} }
/* /*
* 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. * This restores directly out of user space. Exceptions are handled.
*/ */
static inline int restore_i387(struct _fpstate __user *buf) static inline int restore_i387(struct _fpstate __user *buf)
@ -209,4 +179,185 @@ static inline int restore_i387(struct _fpstate __user *buf)
return restore_fpu_checking((__force struct i387_fxsave_struct *)buf); return restore_fpu_checking((__force struct i387_fxsave_struct *)buf);
} }
#endif /* __ASM_X86_64_I387_H */ #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)
__save_init_fpu(me->task);
else
clts();
}
static inline void kernel_fpu_end(void)
{
stts();
preempt_enable();
}
#ifdef CONFIG_X86_64
static inline void save_init_fpu(struct task_struct *tsk)
{
__save_init_fpu(tsk);
stts();
}
#define unlazy_fpu __unlazy_fpu
#define clear_fpu __clear_fpu
#else /* CONFIG_X86_32 */
/*
* These disable preemption on their own and are safe
*/
static inline void save_init_fpu(struct task_struct *tsk)
{
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;
}
}
#endif /* _ASM_X86_I387_H */