kernel-ark/include/asm-mips/fpu.h
Atsushi Nemoto 5323180db7 [MIPS] Disallow CpU exception in kernel again.
The commit 4d40bff7110e9e1a97ff8c01bdd6350e9867cc10 ("Allow CpU
exception in kernel partially") was broken.  The commit was to fix
theoretical problem but broke usual case.  Revert it for now.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-04-20 14:58:37 +01:00

164 lines
3.4 KiB
C

/*
* Copyright (C) 2002 MontaVista Software Inc.
* Author: Jun Sun, jsun@mvista.com or jsun@junsun.net
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*/
#ifndef _ASM_FPU_H
#define _ASM_FPU_H
#include <linux/sched.h>
#include <linux/thread_info.h>
#include <asm/mipsregs.h>
#include <asm/cpu.h>
#include <asm/cpu-features.h>
#include <asm/bitops.h>
#include <asm/processor.h>
#include <asm/current.h>
#ifdef CONFIG_MIPS_MT_FPAFF
#include <asm/mips_mt.h>
#endif
struct sigcontext;
struct sigcontext32;
extern asmlinkage int (*save_fp_context)(struct sigcontext __user *sc);
extern asmlinkage int (*restore_fp_context)(struct sigcontext __user *sc);
extern asmlinkage int (*save_fp_context32)(struct sigcontext32 __user *sc);
extern asmlinkage int (*restore_fp_context32)(struct sigcontext32 __user *sc);
extern void fpu_emulator_init_fpu(void);
extern void _init_fpu(void);
extern void _save_fp(struct task_struct *);
extern void _restore_fp(struct task_struct *);
#if defined(CONFIG_CPU_SB1)
#define __enable_fpu_hazard() \
do { \
asm(".set push \n\t" \
".set mips64 \n\t" \
".set noreorder \n\t" \
"ssnop \n\t" \
"bnezl $0, .+4 \n\t" \
"ssnop \n\t" \
".set pop"); \
} while (0)
#else
#define __enable_fpu_hazard() \
do { \
asm("nop;nop;nop;nop"); /* max. hazard */ \
} while (0)
#endif
#define __enable_fpu() \
do { \
set_c0_status(ST0_CU1); \
__enable_fpu_hazard(); \
} while (0)
#define __disable_fpu() \
do { \
clear_c0_status(ST0_CU1); \
/* We don't care about the c0 hazard here */ \
} while (0)
#define enable_fpu() \
do { \
if (cpu_has_fpu) \
__enable_fpu(); \
} while (0)
#define disable_fpu() \
do { \
if (cpu_has_fpu) \
__disable_fpu(); \
} while (0)
#define clear_fpu_owner() clear_thread_flag(TIF_USEDFPU)
static inline int __is_fpu_owner(void)
{
return test_thread_flag(TIF_USEDFPU);
}
static inline int is_fpu_owner(void)
{
return cpu_has_fpu && __is_fpu_owner();
}
static inline void __own_fpu(void)
{
__enable_fpu();
KSTK_STATUS(current) |= ST0_CU1;
set_thread_flag(TIF_USEDFPU);
}
static inline void own_fpu(int restore)
{
preempt_disable();
if (cpu_has_fpu && !__is_fpu_owner()) {
__own_fpu();
if (restore)
_restore_fp(current);
}
preempt_enable();
}
static inline void lose_fpu(int save)
{
preempt_disable();
if (is_fpu_owner()) {
if (save)
_save_fp(current);
KSTK_STATUS(current) &= ~ST0_CU1;
clear_thread_flag(TIF_USEDFPU);
__disable_fpu();
}
preempt_enable();
}
static inline void init_fpu(void)
{
preempt_disable();
if (cpu_has_fpu) {
__own_fpu();
_init_fpu();
} else {
fpu_emulator_init_fpu();
}
preempt_enable();
}
static inline void save_fp(struct task_struct *tsk)
{
if (cpu_has_fpu)
_save_fp(tsk);
}
static inline void restore_fp(struct task_struct *tsk)
{
if (cpu_has_fpu)
_restore_fp(tsk);
}
static inline fpureg_t *get_fpu_regs(struct task_struct *tsk)
{
if (tsk == current) {
preempt_disable();
if (is_fpu_owner())
_save_fp(current);
preempt_enable();
}
return tsk->thread.fpu.fpr;
}
#endif /* _ASM_FPU_H */