LXR linux/arch/mn10300/include/asm/fpu.h

   1/* MN10300 FPU definitions
   2 *
   3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   4 * Written by David Howells (dhowells@redhat.com)
   5 * Derived from include/asm-i386/i387.h: Copyright (C) 1994 Linus Torvalds
   6 *
   7 * This program is free software; you can redistribute it and/or
   8 * modify it under the terms of the GNU General Public Licence
   9 * as published by the Free Software Foundation; either version
  10 * 2 of the Licence, or (at your option) any later version.
  11 */
  12#ifndef _ASM_FPU_H
  13#define _ASM_FPU_H
  14
  15#ifndef __ASSEMBLY__
  16
  17#include <linux/sched.h>
  18#include <asm/exceptions.h>
  19#include <asm/sigcontext.h>
  20
  21#ifdef __KERNEL__
  22
  23extern asmlinkage void fpu_disabled(void);
  24
  25#ifdef CONFIG_FPU
  26
  27#ifdef CONFIG_LAZY_SAVE_FPU
  28/* the task that currently owns the FPU state */
  29extern struct task_struct *fpu_state_owner;
  30#endif
  31
  32#if (THREAD_USING_FPU & ~0xff)
  33#error THREAD_USING_FPU must be smaller than 0x100.
  34#endif
  35
  36static inline void set_using_fpu(struct task_struct *tsk)
  37{
  38        asm volatile(
  39                "bset %0,(0,%1)"
  40                :
  41                : "i"(THREAD_USING_FPU), "a"(&tsk->thread.fpu_flags)
  42                : "memory", "cc");
  43}
  44
  45static inline void clear_using_fpu(struct task_struct *tsk)
  46{
  47        asm volatile(
  48                "bclr %0,(0,%1)"
  49                :
  50                : "i"(THREAD_USING_FPU), "a"(&tsk->thread.fpu_flags)
  51                : "memory", "cc");
  52}
  53
  54#define is_using_fpu(tsk) ((tsk)->thread.fpu_flags & THREAD_USING_FPU)
  55
  56extern asmlinkage void fpu_kill_state(struct task_struct *);
  57extern asmlinkage void fpu_exception(struct pt_regs *, enum exception_code);
  58extern asmlinkage void fpu_init_state(void);
  59extern asmlinkage void fpu_save(struct fpu_state_struct *);
  60extern int fpu_setup_sigcontext(struct fpucontext *buf);
  61extern int fpu_restore_sigcontext(struct fpucontext *buf);
  62
  63static inline void unlazy_fpu(struct task_struct *tsk)
  64{
  65        preempt_disable();
  66#ifndef CONFIG_LAZY_SAVE_FPU
  67        if (tsk->thread.fpu_flags & THREAD_HAS_FPU) {
  68                fpu_save(&tsk->thread.fpu_state);
  69                tsk->thread.fpu_flags &= ~THREAD_HAS_FPU;
  70                tsk->thread.uregs->epsw &= ~EPSW_FE;
  71        }
  72#else
  73        if (fpu_state_owner == tsk)
  74                fpu_save(&tsk->thread.fpu_state);
  75#endif
  76        preempt_enable();
  77}
  78
  79static inline void exit_fpu(void)
  80{
  81#ifdef CONFIG_LAZY_SAVE_FPU
  82        struct task_struct *tsk = current;
  83
  84        preempt_disable();
  85        if (fpu_state_owner == tsk)
  86                fpu_state_owner = NULL;
  87        preempt_enable();
  88#endif
  89}
  90
  91static inline void flush_fpu(void)
  92{
  93        struct task_struct *tsk = current;
  94
  95        preempt_disable();
  96#ifndef CONFIG_LAZY_SAVE_FPU
  97        if (tsk->thread.fpu_flags & THREAD_HAS_FPU) {
  98                tsk->thread.fpu_flags &= ~THREAD_HAS_FPU;
  99                tsk->thread.uregs->epsw &= ~EPSW_FE;
 100        }
 101#else
 102        if (fpu_state_owner == tsk) {
 103                fpu_state_owner = NULL;
 104                tsk->thread.uregs->epsw &= ~EPSW_FE;
 105        }
 106#endif
 107        preempt_enable();
 108        clear_using_fpu(tsk);
 109}
 110
 111#else /* CONFIG_FPU */
 112
 113extern asmlinkage
 114void unexpected_fpu_exception(struct pt_regs *, enum exception_code);
 115#define fpu_exception unexpected_fpu_exception
 116
 117struct task_struct;
 118struct fpu_state_struct;
 119static inline bool is_using_fpu(struct task_struct *tsk) { return false; }
 120static inline void set_using_fpu(struct task_struct *tsk) {}
 121static inline void clear_using_fpu(struct task_struct *tsk) {}
 122static inline void fpu_init_state(void) {}
 123static inline void fpu_save(struct fpu_state_struct *s) {}
 124static inline void fpu_kill_state(struct task_struct *tsk) {}
 125static inline void unlazy_fpu(struct task_struct *tsk) {}
 126static inline void exit_fpu(void) {}
 127static inline void flush_fpu(void) {}
 128static inline int fpu_setup_sigcontext(struct fpucontext *buf) { return 0; }
 129static inline int fpu_restore_sigcontext(struct fpucontext *buf) { return 0; }
 130#endif /* CONFIG_FPU  */
 131
 132#endif /* __KERNEL__ */
 133#endif /* !__ASSEMBLY__ */
 134#endif /* _ASM_FPU_H */
 135