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Diffstat (limited to 'arch/h8300/include/asm/system.h')
| -rw-r--r-- | arch/h8300/include/asm/system.h | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/arch/h8300/include/asm/system.h b/arch/h8300/include/asm/system.h new file mode 100644 index 000000000000..4b8e475908ae --- /dev/null +++ b/arch/h8300/include/asm/system.h @@ -0,0 +1,158 @@ +#ifndef _H8300_SYSTEM_H +#define _H8300_SYSTEM_H + +#include <linux/linkage.h> + +/* + * switch_to(n) should switch tasks to task ptr, first checking that + * ptr isn't the current task, in which case it does nothing. This + * also clears the TS-flag if the task we switched to has used the + * math co-processor latest. + */ +/* + * switch_to() saves the extra registers, that are not saved + * automatically by SAVE_SWITCH_STACK in resume(), ie. d0-d5 and + * a0-a1. Some of these are used by schedule() and its predecessors + * and so we might get see unexpected behaviors when a task returns + * with unexpected register values. + * + * syscall stores these registers itself and none of them are used + * by syscall after the function in the syscall has been called. + * + * Beware that resume now expects *next to be in d1 and the offset of + * tss to be in a1. This saves a few instructions as we no longer have + * to push them onto the stack and read them back right after. + * + * 02/17/96 - Jes Sorensen (jds@kom.auc.dk) + * + * Changed 96/09/19 by Andreas Schwab + * pass prev in a0, next in a1, offset of tss in d1, and whether + * the mm structures are shared in d2 (to avoid atc flushing). + * + * H8/300 Porting 2002/09/04 Yoshinori Sato + */ + +asmlinkage void resume(void); +#define switch_to(prev,next,last) { \ + void *_last; \ + __asm__ __volatile__( \ + "mov.l %1, er0\n\t" \ + "mov.l %2, er1\n\t" \ + "mov.l %3, er2\n\t" \ + "jsr @_resume\n\t" \ + "mov.l er2,%0\n\t" \ + : "=r" (_last) \ + : "r" (&(prev->thread)), \ + "r" (&(next->thread)), \ + "g" (prev) \ + : "cc", "er0", "er1", "er2", "er3"); \ + (last) = _last; \ +} + +#define __sti() asm volatile ("andc #0x7f,ccr") +#define __cli() asm volatile ("orc #0x80,ccr") + +#define __save_flags(x) \ + asm volatile ("stc ccr,%w0":"=r" (x)) + +#define __restore_flags(x) \ + asm volatile ("ldc %w0,ccr": :"r" (x)) + +#define irqs_disabled() \ +({ \ + unsigned char flags; \ + __save_flags(flags); \ + ((flags & 0x80) == 0x80); \ +}) + +#define iret() __asm__ __volatile__ ("rte": : :"memory", "sp", "cc") + +/* For spinlocks etc */ +#define local_irq_disable() __cli() +#define local_irq_enable() __sti() +#define local_irq_save(x) ({ __save_flags(x); local_irq_disable(); }) +#define local_irq_restore(x) __restore_flags(x) +#define local_save_flags(x) __save_flags(x) + +/* + * Force strict CPU ordering. + * Not really required on H8... + */ +#define nop() asm volatile ("nop"::) +#define mb() asm volatile ("" : : :"memory") +#define rmb() asm volatile ("" : : :"memory") +#define wmb() asm volatile ("" : : :"memory") +#define set_mb(var, value) do { xchg(&var, value); } while (0) + +#ifdef CONFIG_SMP +#define smp_mb() mb() +#define smp_rmb() rmb() +#define smp_wmb() wmb() +#define smp_read_barrier_depends() read_barrier_depends() +#else +#define smp_mb() barrier() +#define smp_rmb() barrier() +#define smp_wmb() barrier() +#define smp_read_barrier_depends() do { } while(0) +#endif + +#define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr)))) + +struct __xchg_dummy { unsigned long a[100]; }; +#define __xg(x) ((volatile struct __xchg_dummy *)(x)) + +static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size) +{ + unsigned long tmp, flags; + + local_irq_save(flags); + + switch (size) { + case 1: + __asm__ __volatile__ + ("mov.b %2,%0\n\t" + "mov.b %1,%2" + : "=&r" (tmp) : "r" (x), "m" (*__xg(ptr)) : "memory"); + break; + case 2: + __asm__ __volatile__ + ("mov.w %2,%0\n\t" + "mov.w %1,%2" + : "=&r" (tmp) : "r" (x), "m" (*__xg(ptr)) : "memory"); + break; + case 4: + __asm__ __volatile__ + ("mov.l %2,%0\n\t" + "mov.l %1,%2" + : "=&r" (tmp) : "r" (x), "m" (*__xg(ptr)) : "memory"); + break; + default: + tmp = 0; + } + local_irq_restore(flags); + return tmp; +} + +#define HARD_RESET_NOW() ({ \ + local_irq_disable(); \ + asm("jmp @@0"); \ +}) + +#include <asm-generic/cmpxchg-local.h> + +/* + * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make + * them available. + */ +#define cmpxchg_local(ptr, o, n) \ + ((__typeof__(*(ptr)))__cmpxchg_local_generic((ptr), (unsigned long)(o),\ + (unsigned long)(n), sizeof(*(ptr)))) +#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n)) + +#ifndef CONFIG_SMP +#include <asm-generic/cmpxchg.h> +#endif + +#define arch_align_stack(x) (x) + +#endif /* _H8300_SYSTEM_H */ |