From 278d91c4609d55202c1e63d5fc5f01466cc7bbab Mon Sep 17 00:00:00 2001 From: Akira Takeuchi Date: Wed, 27 Oct 2010 17:28:52 +0100 Subject: MN10300: Make the FPU operate in non-lazy mode under SMP Make the FPU operate in non-lazy mode under SMP so that when the process that is currently using the FPU migrates to a different CPU, we don't have to ping its previous CPU to flush the FPU context. Signed-off-by: Akira Takeuchi Signed-off-by: Kiyoshi Owada Signed-off-by: David Howells --- arch/mn10300/include/asm/elf.h | 2 - arch/mn10300/include/asm/exceptions.h | 1 - arch/mn10300/include/asm/fpu.h | 157 ++++++++++++++++++++++------------ arch/mn10300/include/asm/processor.h | 1 + arch/mn10300/include/asm/system.h | 16 ++++ 5 files changed, 121 insertions(+), 56 deletions(-) (limited to 'arch/mn10300/include') diff --git a/arch/mn10300/include/asm/elf.h b/arch/mn10300/include/asm/elf.h index e5fa97cd9a14..a30d220de5ca 100644 --- a/arch/mn10300/include/asm/elf.h +++ b/arch/mn10300/include/asm/elf.h @@ -47,8 +47,6 @@ typedef struct { u_int32_t fpcr; } elf_fpregset_t; -extern int dump_fpu(struct pt_regs *, elf_fpregset_t *); - /* * This is used to ensure we don't load something for the wrong architecture */ diff --git a/arch/mn10300/include/asm/exceptions.h b/arch/mn10300/include/asm/exceptions.h index 3f3826abc745..7d8080bc6590 100644 --- a/arch/mn10300/include/asm/exceptions.h +++ b/arch/mn10300/include/asm/exceptions.h @@ -101,7 +101,6 @@ extern asmlinkage void dtlb_aerror(void); extern asmlinkage void raw_bus_error(void); extern asmlinkage void double_fault(void); extern asmlinkage int system_call(struct pt_regs *); -extern asmlinkage void fpu_exception(struct pt_regs *, enum exception_code); extern asmlinkage void nmi(struct pt_regs *, enum exception_code); extern asmlinkage void uninitialised_exception(struct pt_regs *, enum exception_code); diff --git a/arch/mn10300/include/asm/fpu.h b/arch/mn10300/include/asm/fpu.h index 64a2b83a7a6a..b7625de8eade 100644 --- a/arch/mn10300/include/asm/fpu.h +++ b/arch/mn10300/include/asm/fpu.h @@ -12,74 +12,125 @@ #ifndef _ASM_FPU_H #define _ASM_FPU_H -#include +#ifndef __ASSEMBLY__ + +#include +#include #include -#include #ifdef __KERNEL__ -/* the task that owns the FPU state */ +extern asmlinkage void fpu_disabled(void); + +#ifdef CONFIG_FPU + +#ifdef CONFIG_LAZY_SAVE_FPU +/* the task that currently owns the FPU state */ extern struct task_struct *fpu_state_owner; +#endif -#define set_using_fpu(tsk) \ -do { \ - (tsk)->thread.fpu_flags |= THREAD_USING_FPU; \ -} while (0) +#if (THREAD_USING_FPU & ~0xff) +#error THREAD_USING_FPU must be smaller than 0x100. +#endif -#define clear_using_fpu(tsk) \ -do { \ - (tsk)->thread.fpu_flags &= ~THREAD_USING_FPU; \ -} while (0) +static inline void set_using_fpu(struct task_struct *tsk) +{ + asm volatile( + "bset %0,(0,%1)" + : + : "i"(THREAD_USING_FPU), "a"(&tsk->thread.fpu_flags) + : "memory", "cc"); +} -#define is_using_fpu(tsk) ((tsk)->thread.fpu_flags & THREAD_USING_FPU) +static inline void clear_using_fpu(struct task_struct *tsk) +{ + asm volatile( + "bclr %0,(0,%1)" + : + : "i"(THREAD_USING_FPU), "a"(&tsk->thread.fpu_flags) + : "memory", "cc"); +} -#define unlazy_fpu(tsk) \ -do { \ - preempt_disable(); \ - if (fpu_state_owner == (tsk)) \ - fpu_save(&tsk->thread.fpu_state); \ - preempt_enable(); \ -} while (0) - -#define exit_fpu() \ -do { \ - struct task_struct *__tsk = current; \ - preempt_disable(); \ - if (fpu_state_owner == __tsk) \ - fpu_state_owner = NULL; \ - preempt_enable(); \ -} while (0) - -#define flush_fpu() \ -do { \ - struct task_struct *__tsk = current; \ - preempt_disable(); \ - if (fpu_state_owner == __tsk) { \ - fpu_state_owner = NULL; \ - __tsk->thread.uregs->epsw &= ~EPSW_FE; \ - } \ - preempt_enable(); \ - clear_using_fpu(__tsk); \ -} while (0) +#define is_using_fpu(tsk) ((tsk)->thread.fpu_flags & THREAD_USING_FPU) -extern asmlinkage void fpu_init_state(void); extern asmlinkage void fpu_kill_state(struct task_struct *); -extern asmlinkage void fpu_disabled(struct pt_regs *, enum exception_code); extern asmlinkage void fpu_exception(struct pt_regs *, enum exception_code); - -#ifdef CONFIG_FPU +extern asmlinkage void fpu_invalid_op(struct pt_regs *, enum exception_code); +extern asmlinkage void fpu_init_state(void); extern asmlinkage void fpu_save(struct fpu_state_struct *); -extern asmlinkage void fpu_restore(struct fpu_state_struct *); -#else -#define fpu_save(a) -#define fpu_restore(a) -#endif /* CONFIG_FPU */ - -/* - * signal frame handlers - */ extern int fpu_setup_sigcontext(struct fpucontext *buf); extern int fpu_restore_sigcontext(struct fpucontext *buf); +static inline void unlazy_fpu(struct task_struct *tsk) +{ + preempt_disable(); +#ifndef CONFIG_LAZY_SAVE_FPU + if (tsk->thread.fpu_flags & THREAD_HAS_FPU) { + fpu_save(&tsk->thread.fpu_state); + tsk->thread.fpu_flags &= ~THREAD_HAS_FPU; + tsk->thread.uregs->epsw &= ~EPSW_FE; + } +#else + if (fpu_state_owner == tsk) + fpu_save(&tsk->thread.fpu_state); +#endif + preempt_enable(); +} + +static inline void exit_fpu(void) +{ +#ifdef CONFIG_LAZY_SAVE_FPU + struct task_struct *tsk = current; + + preempt_disable(); + if (fpu_state_owner == tsk) + fpu_state_owner = NULL; + preempt_enable(); +#endif +} + +static inline void flush_fpu(void) +{ + struct task_struct *tsk = current; + + preempt_disable(); +#ifndef CONFIG_LAZY_SAVE_FPU + if (tsk->thread.fpu_flags & THREAD_HAS_FPU) { + tsk->thread.fpu_flags &= ~THREAD_HAS_FPU; + tsk->thread.uregs->epsw &= ~EPSW_FE; + } +#else + if (fpu_state_owner == tsk) { + fpu_state_owner = NULL; + tsk->thread.uregs->epsw &= ~EPSW_FE; + } +#endif + preempt_enable(); + clear_using_fpu(tsk); +} + +#else /* CONFIG_FPU */ + +extern asmlinkage +void unexpected_fpu_exception(struct pt_regs *, enum exception_code); +#define fpu_invalid_op unexpected_fpu_exception +#define fpu_exception unexpected_fpu_exception + +struct task_struct; +struct fpu_state_struct; +static inline bool is_using_fpu(struct task_struct *tsk) { return false; } +static inline void set_using_fpu(struct task_struct *tsk) {} +static inline void clear_using_fpu(struct task_struct *tsk) {} +static inline void fpu_init_state(void) {} +static inline void fpu_save(struct fpu_state_struct *s) {} +static inline void fpu_kill_state(struct task_struct *tsk) {} +static inline void unlazy_fpu(struct task_struct *tsk) {} +static inline void exit_fpu(void) {} +static inline void flush_fpu(void) {} +static inline int fpu_setup_sigcontext(struct fpucontext *buf) { return 0; } +static inline int fpu_restore_sigcontext(struct fpucontext *buf) { return 0; } +#endif /* CONFIG_FPU */ + #endif /* __KERNEL__ */ +#endif /* !__ASSEMBLY__ */ #endif /* _ASM_FPU_H */ diff --git a/arch/mn10300/include/asm/processor.h b/arch/mn10300/include/asm/processor.h index fd96c180e649..0032fc76c8ba 100644 --- a/arch/mn10300/include/asm/processor.h +++ b/arch/mn10300/include/asm/processor.h @@ -95,6 +95,7 @@ struct thread_struct { struct pt_regs *__frame; unsigned long fpu_flags; #define THREAD_USING_FPU 0x00000001 /* T if this task is using the FPU */ +#define THREAD_HAS_FPU 0x00000002 /* T if this task owns the FPU right now */ struct fpu_state_struct fpu_state; }; diff --git a/arch/mn10300/include/asm/system.h b/arch/mn10300/include/asm/system.h index 9f7c7e17c01e..3c272a1a1015 100644 --- a/arch/mn10300/include/asm/system.h +++ b/arch/mn10300/include/asm/system.h @@ -19,6 +19,21 @@ #include #include +#if !defined(CONFIG_LAZY_SAVE_FPU) +struct fpu_state_struct; +extern asmlinkage void fpu_save(struct fpu_state_struct *); +#define switch_fpu(prev, next) \ + do { \ + if ((prev)->thread.fpu_flags & THREAD_HAS_FPU) { \ + (prev)->thread.fpu_flags &= ~THREAD_HAS_FPU; \ + (prev)->thread.uregs->epsw &= ~EPSW_FE; \ + fpu_save(&(prev)->thread.fpu_state); \ + } \ + } while (0) +#else +#define switch_fpu(prev, next) do {} while (0) +#endif + struct task_struct; struct thread_struct; @@ -30,6 +45,7 @@ struct task_struct *__switch_to(struct thread_struct *prev, /* context switching is now performed out-of-line in switch_to.S */ #define switch_to(prev, next, last) \ do { \ + switch_fpu(prev, next); \ current->thread.wchan = (u_long) __builtin_return_address(0); \ (last) = __switch_to(&(prev)->thread, &(next)->thread, (prev)); \ mb(); \ -- cgit v1.2.3