+++ /dev/null
-/*
- * 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 _X86_64_I387_H
-#define _X86_64_I387_H
-
-#include <lwk/task.h>
-#include <lwk/errno.h>
-#include <arch/processor.h>
-#include <arch/sigcontext.h>
-#include <arch/user.h>
-#include <arch/uaccess.h>
-
-extern void fpu_init(void);
-extern unsigned int mxcsr_feature_mask;
-extern void mxcsr_feature_mask_init(void);
-
-/* 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->arch.status & TS_USEDFPU) { \
- tolerant_fwait(); \
- tsk->arch.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)->arch.i387.fxsave.mxcsr)
-#define get_fpu_cwd(t) ((t)->arch.i387.fxsave.cwd)
-#define get_fpu_fxsr_twd(t) ((t)->arch.i387.fxsave.twd)
-#define get_fpu_swd(t) ((t)->arch.i387.fxsave.swd)
-#define set_fpu_cwd(t,val) ((t)->arch.i387.fxsave.cwd = (val))
-#define set_fpu_swd(t,val) ((t)->arch.i387.fxsave.swd = (val))
-#define set_fpu_fxsr_twd(t,val) ((t)->arch.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");
-
- /*
- * Unconditional fix for AMD CPUs that don't save/restore FDP/FIP/FOP.
- * TODO: some CPUs may not need this, possibly use Linux
- * alternative_input() mechanism.
- */
- asm volatile ("emms"); /* clear stack tags */
- asm volatile ("fildl %gs:0"); /* load to clear state */
-}
-
-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), "=m" (*fx)
-#if 0 /* See comment in __fxsave_clear() below. */
- : [fx] "r" (fx), "0" (0));
-#else
- : [fx] "cdaSDb" (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 __fxsave_clear(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
- will be generated (to the assembler, rex64 followed by semicolon
- is a separate instruction), and hence the 64-bitness is lost. */
-#if 0
- /* Using "fxsaveq %0" would be the ideal choice, but is only supported
- starting with gas 2.16. */
- __asm__ __volatile__("fxsaveq %0"
- : "=m" (tsk->arch.thread.i387.fxsave));
-#elif 0
- /* 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" (tsk->arch.thread.i387.fxsave));
-#else
- /* 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 %P2(%1)"
- : "=m" (tsk->arch.thread.i387.fxsave)
- : "cdaSDb" (tsk),
- "i" (offsetof(__typeof__(*tsk),
- arch.thread.i387.fxsave)));
-#endif
- clear_fpu_state(&tsk->arch.thread.i387.fxsave);
-}
-
-static inline void kernel_fpu_begin(void)
-{
- if (current->arch.flags & TF_USED_FPU) {
- __fxsave_clear(current);
- return;
- }
- clts();
-}
-
-static inline void kernel_fpu_end(void)
-{
- stts();
-}
-
-static inline void
-fpu_save_state(struct task_struct *task)
-{
- __asm__ __volatile__("fxsaveq %0"
- : "=m" (task->arch.thread.i387.fxsave));
- clear_fpu_state(&task->arch.thread.i387.fxsave);
-}
-
-static inline void
-fpu_restore_state(struct task_struct *task)
-{
- __asm__ __volatile__("fxrstorq %0"
- ::"m" (task->arch.thread.i387.fxsave));
-}
-
-#endif /* _X86_64_I387_H */