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