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Diffstat (limited to 'include/asm-x86_64/i387.h')
| -rw-r--r-- | include/asm-x86_64/i387.h | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/include/asm-x86_64/i387.h b/include/asm-x86_64/i387.h new file mode 100644 index 000000000000..aa39cfd0e001 --- /dev/null +++ b/include/asm-x86_64/i387.h @@ -0,0 +1,150 @@ +/* + * include/asm-x86_64/i387.h + * + * 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 __ASM_X86_64_I387_H +#define __ASM_X86_64_I387_H + +#include <linux/sched.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); + +/* + * FPU lazy state save handling... + */ + +#define unlazy_fpu(tsk) do { \ + if ((tsk)->thread_info->status & TS_USEDFPU) \ + save_init_fpu(tsk); \ +} while (0) + +/* Ignore delayed exceptions from user space */ +static inline void tolerant_fwait(void) +{ + asm volatile("1: fwait\n" + "2:\n" + " .section __ex_table,\"a\"\n" + " .align 8\n" + " .quad 1b,2b\n" + " .previous\n"); +} + +#define clear_fpu(tsk) do { \ + if ((tsk)->thread_info->status & TS_USEDFPU) { \ + tolerant_fwait(); \ + (tsk)->thread_info->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)) + +static inline int restore_fpu_checking(struct i387_fxsave_struct *fx) +{ + int err; + asm volatile("1: rex64 ; fxrstor (%[fx])\n\t" + "2:\n" + ".section .fixup,\"ax\"\n" + "3: movl $-1,%[err]\n" + " jmp 2b\n" + ".previous\n" + ".section __ex_table,\"a\"\n" + " .align 8\n" + " .quad 1b,3b\n" + ".previous" + : [err] "=r" (err) + : [fx] "r" (fx), "0" (0)); + if (unlikely(err)) + init_fpu(current); + return err; +} + +static inline int save_i387_checking(struct i387_fxsave_struct __user *fx) +{ + int err; + asm volatile("1: rex64 ; fxsave (%[fx])\n\t" + "2:\n" + ".section .fixup,\"ax\"\n" + "3: movl $-1,%[err]\n" + " jmp 2b\n" + ".previous\n" + ".section __ex_table,\"a\"\n" + " .align 8\n" + " .quad 1b,3b\n" + ".previous" + : [err] "=r" (err) + : [fx] "r" (fx), "0" (0)); + if (unlikely(err)) + __clear_user(fx, sizeof(struct i387_fxsave_struct)); + return err; +} + +static inline void kernel_fpu_begin(void) +{ + struct thread_info *me = current_thread_info(); + preempt_disable(); + if (me->status & TS_USEDFPU) { + asm volatile("rex64 ; fxsave %0 ; fnclex" + : "=m" (me->task->thread.i387.fxsave)); + 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 ) +{ + asm volatile( "rex64 ; fxsave %0 ; fnclex" + : "=m" (tsk->thread.i387.fxsave)); + tsk->thread_info->status &= ~TS_USEDFPU; + stts(); +} + +/* + * This restores directly out of user space. Exceptions are handled. + */ +static inline int restore_i387(struct _fpstate __user *buf) +{ + return restore_fpu_checking((__force struct i387_fxsave_struct *)buf); +} + +#endif /* __ASM_X86_64_I387_H */ |