forked from mirrors/linux
		
	This header isn't exported to user-space, and even if it was, the __KERNEL__ check covers the entire file, so we'd get a useless stub in the first place. So punt it. Signed-off-by: Mike Frysinger <vapier@gentoo.org> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
		
			
				
	
	
		
			141 lines
		
	
	
	
		
			3.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			141 lines
		
	
	
	
		
			3.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* Generic system definitions, based on MN10300 definitions.
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 *
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 * It should be possible to use these on really simple architectures,
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 * but it serves more as a starting point for new ports.
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 *
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 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
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 * Written by David Howells (dhowells@redhat.com)
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 *
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 * This program is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU General Public Licence
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 * as published by the Free Software Foundation; either version
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 * 2 of the Licence, or (at your option) any later version.
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 */
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#ifndef __ASM_GENERIC_SYSTEM_H
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#define __ASM_GENERIC_SYSTEM_H
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#ifndef __ASSEMBLY__
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#include <linux/types.h>
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#include <linux/irqflags.h>
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#include <asm/cmpxchg-local.h>
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#include <asm/cmpxchg.h>
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struct task_struct;
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/* context switching is now performed out-of-line in switch_to.S */
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extern struct task_struct *__switch_to(struct task_struct *,
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		struct task_struct *);
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#define switch_to(prev, next, last)					\
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	do {								\
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		((last) = __switch_to((prev), (next)));			\
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	} while (0)
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#define arch_align_stack(x) (x)
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#define nop() asm volatile ("nop")
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#endif /* !__ASSEMBLY__ */
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/*
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 * Force strict CPU ordering.
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 * And yes, this is required on UP too when we're talking
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 * to devices.
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 *
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 * This implementation only contains a compiler barrier.
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 */
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#define mb()	asm volatile ("": : :"memory")
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#define rmb()	mb()
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#define wmb()	asm volatile ("": : :"memory")
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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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#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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#endif
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#define set_mb(var, value)  do { var = value;  mb(); } while (0)
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#define set_wmb(var, value) do { var = value; wmb(); } while (0)
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#define read_barrier_depends()		do {} while (0)
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#define smp_read_barrier_depends()	do {} while (0)
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/*
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 * we make sure local_irq_enable() doesn't cause priority inversion
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 */
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#ifndef __ASSEMBLY__
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/* This function doesn't exist, so you'll get a linker error
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 *    if something tries to do an invalid xchg().  */
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extern void __xchg_called_with_bad_pointer(void);
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static inline
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unsigned long __xchg(unsigned long x, volatile void *ptr, int size)
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{
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	unsigned long ret, flags;
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	switch (size) {
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	case 1:
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#ifdef __xchg_u8
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		return __xchg_u8(x, ptr);
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#else
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		local_irq_save(flags);
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		ret = *(volatile u8 *)ptr;
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		*(volatile u8 *)ptr = x;
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		local_irq_restore(flags);
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		return ret;
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#endif /* __xchg_u8 */
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	case 2:
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#ifdef __xchg_u16
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		return __xchg_u16(x, ptr);
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#else
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		local_irq_save(flags);
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		ret = *(volatile u16 *)ptr;
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		*(volatile u16 *)ptr = x;
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		local_irq_restore(flags);
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		return ret;
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#endif /* __xchg_u16 */
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	case 4:
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#ifdef __xchg_u32
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		return __xchg_u32(x, ptr);
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#else
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		local_irq_save(flags);
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		ret = *(volatile u32 *)ptr;
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		*(volatile u32 *)ptr = x;
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		local_irq_restore(flags);
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		return ret;
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#endif /* __xchg_u32 */
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#ifdef CONFIG_64BIT
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	case 8:
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#ifdef __xchg_u64
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		return __xchg_u64(x, ptr);
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#else
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		local_irq_save(flags);
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		ret = *(volatile u64 *)ptr;
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		*(volatile u64 *)ptr = x;
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		local_irq_restore(flags);
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		return ret;
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#endif /* __xchg_u64 */
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#endif /* CONFIG_64BIT */
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	default:
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		__xchg_called_with_bad_pointer();
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		return x;
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	}
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}
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#define xchg(ptr, x) \
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	((__typeof__(*(ptr))) __xchg((unsigned long)(x), (ptr), sizeof(*(ptr))))
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#endif /* !__ASSEMBLY__ */
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#endif /* __ASM_GENERIC_SYSTEM_H */
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