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Diffstat (limited to 'arch/mn10300/include/asm/system.h')
| -rw-r--r-- | arch/mn10300/include/asm/system.h | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/arch/mn10300/include/asm/system.h b/arch/mn10300/include/asm/system.h new file mode 100644 index 000000000000..8214fb7e7fe4 --- /dev/null +++ b/arch/mn10300/include/asm/system.h @@ -0,0 +1,237 @@ +/* MN10300 System definitions + * + * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ +#ifndef _ASM_SYSTEM_H +#define _ASM_SYSTEM_H + +#include <asm/cpu-regs.h> + +#ifdef __KERNEL__ +#ifndef __ASSEMBLY__ + +#include <linux/kernel.h> + +struct task_struct; +struct thread_struct; + +extern asmlinkage +struct task_struct *__switch_to(struct thread_struct *prev, + struct thread_struct *next, + struct task_struct *prev_task); + +/* context switching is now performed out-of-line in switch_to.S */ +#define switch_to(prev, next, last) \ +do { \ + current->thread.wchan = (u_long) __builtin_return_address(0); \ + (last) = __switch_to(&(prev)->thread, &(next)->thread, (prev)); \ + mb(); \ + current->thread.wchan = 0; \ +} while (0) + +#define arch_align_stack(x) (x) + +#define nop() asm volatile ("nop") + +#endif /* !__ASSEMBLY__ */ + +/* + * Force strict CPU ordering. + * And yes, this is required on UP too when we're talking + * to devices. + * + * For now, "wmb()" doesn't actually do anything, as all + * Intel CPU's follow what Intel calls a *Processor Order*, + * in which all writes are seen in the program order even + * outside the CPU. + * + * I expect future Intel CPU's to have a weaker ordering, + * but I'd also expect them to finally get their act together + * and add some real memory barriers if so. + * + * Some non intel clones support out of order store. wmb() ceases to be a + * nop for these. + */ + +#define mb() asm volatile ("": : :"memory") +#define rmb() mb() +#define wmb() asm volatile ("": : :"memory") + +#ifdef CONFIG_SMP +#define smp_mb() mb() +#define smp_rmb() rmb() +#define smp_wmb() wmb() +#else +#define smp_mb() barrier() +#define smp_rmb() barrier() +#define smp_wmb() barrier() +#endif + +#define set_mb(var, value) do { var = value; mb(); } while (0) +#define set_wmb(var, value) do { var = value; wmb(); } while (0) + +#define read_barrier_depends() do {} while (0) +#define smp_read_barrier_depends() do {} while (0) + +/*****************************************************************************/ +/* + * interrupt control + * - "disabled": run in IM1/2 + * - level 0 - GDB stub + * - level 1 - virtual serial DMA (if present) + * - level 5 - normal interrupt priority + * - level 6 - timer interrupt + * - "enabled": run in IM7 + */ +#ifdef CONFIG_MN10300_TTYSM +#define MN10300_CLI_LEVEL EPSW_IM_2 +#else +#define MN10300_CLI_LEVEL EPSW_IM_1 +#endif + +#define local_save_flags(x) \ +do { \ + typecheck(unsigned long, x); \ + asm volatile( \ + " mov epsw,%0 \n" \ + : "=d"(x) \ + ); \ +} while (0) + +#define local_irq_disable() \ +do { \ + asm volatile( \ + " and %0,epsw \n" \ + " or %1,epsw \n" \ + " nop \n" \ + " nop \n" \ + " nop \n" \ + : \ + : "i"(~EPSW_IM), "i"(EPSW_IE | MN10300_CLI_LEVEL) \ + ); \ +} while (0) + +#define local_irq_save(x) \ +do { \ + local_save_flags(x); \ + local_irq_disable(); \ +} while (0) + +/* + * we make sure local_irq_enable() doesn't cause priority inversion + */ +#ifndef __ASSEMBLY__ + +extern unsigned long __mn10300_irq_enabled_epsw; + +#endif + +#define local_irq_enable() \ +do { \ + unsigned long tmp; \ + \ + asm volatile( \ + " mov epsw,%0 \n" \ + " and %1,%0 \n" \ + " or %2,%0 \n" \ + " mov %0,epsw \n" \ + : "=&d"(tmp) \ + : "i"(~EPSW_IM), "r"(__mn10300_irq_enabled_epsw) \ + ); \ +} while (0) + +#define local_irq_restore(x) \ +do { \ + typecheck(unsigned long, x); \ + asm volatile( \ + " mov %0,epsw \n" \ + " nop \n" \ + " nop \n" \ + " nop \n" \ + : \ + : "d"(x) \ + : "memory", "cc" \ + ); \ +} while (0) + +#define irqs_disabled() \ +({ \ + unsigned long flags; \ + local_save_flags(flags); \ + (flags & EPSW_IM) <= MN10300_CLI_LEVEL; \ +}) + +/* hook to save power by halting the CPU + * - called from the idle loop + * - must reenable interrupts (which takes three instruction cycles to complete) + */ +#define safe_halt() \ +do { \ + asm volatile(" or %0,epsw \n" \ + " nop \n" \ + " nop \n" \ + " bset %2,(%1) \n" \ + : \ + : "i"(EPSW_IE|EPSW_IM), "n"(&CPUM), "i"(CPUM_SLEEP)\ + : "cc" \ + ); \ +} while (0) + +#define STI or EPSW_IE|EPSW_IM,epsw +#define CLI and ~EPSW_IM,epsw; or EPSW_IE|MN10300_CLI_LEVEL,epsw; nop; nop; nop + +/*****************************************************************************/ +/* + * MN10300 doesn't actually have an exchange instruction + */ +#ifndef __ASSEMBLY__ + +struct __xchg_dummy { unsigned long a[100]; }; +#define __xg(x) ((struct __xchg_dummy *)(x)) + +static inline +unsigned long __xchg(volatile unsigned long *m, unsigned long val) +{ + unsigned long retval; + unsigned long flags; + + local_irq_save(flags); + retval = *m; + *m = val; + local_irq_restore(flags); + return retval; +} + +#define xchg(ptr, v) \ + ((__typeof__(*(ptr))) __xchg((unsigned long *)(ptr), \ + (unsigned long)(v))) + +static inline unsigned long __cmpxchg(volatile unsigned long *m, + unsigned long old, unsigned long new) +{ + unsigned long retval; + unsigned long flags; + + local_irq_save(flags); + retval = *m; + if (retval == old) + *m = new; + local_irq_restore(flags); + return retval; +} + +#define cmpxchg(ptr, o, n) \ + ((__typeof__(*(ptr))) __cmpxchg((unsigned long *)(ptr), \ + (unsigned long)(o), \ + (unsigned long)(n))) + +#endif /* !__ASSEMBLY__ */ + +#endif /* __KERNEL__ */ +#endif /* _ASM_SYSTEM_H */ |