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
  23 extern 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 */
  29 extern 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
  36 static 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
  45 static 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
  56 extern asmlinkage void fpu_kill_state(struct task_struct *);
  57 extern asmlinkage void fpu_exception(struct pt_regs *, enum exception_code);
  58 extern asmlinkage void fpu_init_state(void);
  59 extern asmlinkage void fpu_save(struct fpu_state_struct *);
  60 extern int fpu_setup_sigcontext(struct fpucontext *buf);
  61 extern int fpu_restore_sigcontext(struct fpucontext *buf);
  62
  63 static 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
  79 static 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
  91 static 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
 113 extern asmlinkage
 114 void unexpected_fpu_exception(struct pt_regs *, enum exception_code);
 115 #define fpu_exception unexpected_fpu_exception
 116
 117 struct task_struct;
 118 struct fpu_state_struct;
 119 static inline bool is_using_fpu(struct task_struct *tsk) { return false; }
 120 static inline void set_using_fpu(struct task_struct *tsk) {}
 121 static inline void clear_using_fpu(struct task_struct *tsk) {}
 122 static inline void fpu_init_state(void) {}
 123 static inline void fpu_save(struct fpu_state_struct *s) {}
 124 static inline void fpu_kill_state(struct task_struct *tsk) {}
 125 static inline void unlazy_fpu(struct task_struct *tsk) {}
 126 static inline void exit_fpu(void) {}
 127 static inline void flush_fpu(void) {}
 128 static inline int fpu_setup_sigcontext(struct fpucontext *buf) { return 0; }
 129 static 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 */