aafe4dbed0
These are all kernel internal interfaces that get copied around a lot. In most cases, architectures can provide their own optimized versions, but these generic versions can work as well. I have tried to use the most common contents of each header to allow existing architectures to migrate easily. Thanks to Remis for suggesting a number of cleanups. Signed-off-by: Remis Lima Baima <remis.developer@googlemail.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
161 lines
3.7 KiB
C
161 lines
3.7 KiB
C
/* Generic system definitions, based on MN10300 definitions.
|
|
*
|
|
* It should be possible to use these on really simple architectures,
|
|
* but it serves more as a starting point for new ports.
|
|
*
|
|
* 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_GENERIC_SYSTEM_H
|
|
#define __ASM_GENERIC_SYSTEM_H
|
|
|
|
#ifdef __KERNEL__
|
|
#ifndef __ASSEMBLY__
|
|
|
|
#include <linux/types.h>
|
|
#include <linux/irqflags.h>
|
|
|
|
#include <asm/cmpxchg-local.h>
|
|
|
|
struct task_struct;
|
|
|
|
/* context switching is now performed out-of-line in switch_to.S */
|
|
extern struct task_struct *__switch_to(struct task_struct *,
|
|
struct task_struct *);
|
|
#define switch_to(prev, next, last) \
|
|
do { \
|
|
((last) = __switch_to((prev), (next))); \
|
|
} 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.
|
|
*
|
|
* This implementation only contains a compiler barrier.
|
|
*/
|
|
|
|
#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)
|
|
|
|
/*
|
|
* we make sure local_irq_enable() doesn't cause priority inversion
|
|
*/
|
|
#ifndef __ASSEMBLY__
|
|
|
|
/* This function doesn't exist, so you'll get a linker error
|
|
* if something tries to do an invalid xchg(). */
|
|
extern void __xchg_called_with_bad_pointer(void);
|
|
|
|
static inline
|
|
unsigned long __xchg(unsigned long x, volatile void *ptr, int size)
|
|
{
|
|
unsigned long ret, flags;
|
|
|
|
switch (size) {
|
|
case 1:
|
|
#ifdef __xchg_u8
|
|
return __xchg_u8(x, ptr);
|
|
#else
|
|
local_irq_save(flags);
|
|
ret = *(volatile u8 *)ptr;
|
|
*(volatile u8 *)ptr = x;
|
|
local_irq_restore(flags);
|
|
return ret;
|
|
#endif /* __xchg_u8 */
|
|
|
|
case 2:
|
|
#ifdef __xchg_u16
|
|
return __xchg_u16(x, ptr);
|
|
#else
|
|
local_irq_save(flags);
|
|
ret = *(volatile u16 *)ptr;
|
|
*(volatile u16 *)ptr = x;
|
|
local_irq_restore(flags);
|
|
return ret;
|
|
#endif /* __xchg_u16 */
|
|
|
|
case 4:
|
|
#ifdef __xchg_u32
|
|
return __xchg_u32(x, ptr);
|
|
#else
|
|
local_irq_save(flags);
|
|
ret = *(volatile u32 *)ptr;
|
|
*(volatile u32 *)ptr = x;
|
|
local_irq_restore(flags);
|
|
return ret;
|
|
#endif /* __xchg_u32 */
|
|
|
|
#ifdef CONFIG_64BIT
|
|
case 8:
|
|
#ifdef __xchg_u64
|
|
return __xchg_u64(x, ptr);
|
|
#else
|
|
local_irq_save(flags);
|
|
ret = *(volatile u64 *)ptr;
|
|
*(volatile u64 *)ptr = x;
|
|
local_irq_restore(flags);
|
|
return ret;
|
|
#endif /* __xchg_u64 */
|
|
#endif /* CONFIG_64BIT */
|
|
|
|
default:
|
|
__xchg_called_with_bad_pointer();
|
|
return x;
|
|
}
|
|
}
|
|
|
|
#define xchg(ptr, x) \
|
|
((__typeof__(*(ptr))) __xchg((unsigned long)(x), (ptr), sizeof(*(ptr))))
|
|
|
|
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_GENERIC_SYSTEM_H */
|