/*
* Copyright (C) 2004-2006 Atmel Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef __ASM_AVR32_SYSTEM_H
#define __ASM_AVR32_SYSTEM_H
#include <linux/compiler.h>
#include <linux/linkage.h>
#include <linux/types.h>
#include <asm/ptrace.h>
#include <asm/sysreg.h>
#define xchg(ptr,x) \
((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
#define nop() asm volatile("nop")
#define mb() asm volatile("" : : : "memory")
#define rmb() mb()
#define wmb() asm volatile("sync 0" : : : "memory")
#define read_barrier_depends() do { } while(0)
#define set_mb(var, value) do { var = value; mb(); } while(0)
/*
* Help PathFinder and other Nexus-compliant debuggers keep track of
* the current PID by emitting an Ownership Trace Message each time we
* switch task.
*/
#ifdef CONFIG_OWNERSHIP_TRACE
#include <asm/ocd.h>
#define finish_arch_switch(prev) \
do { \
ocd_write(PID, prev->pid); \
ocd_write(PID, current->pid); \
} while(0)
#endif
/*
* switch_to(prev, next, last) should switch from task `prev' to task
* `next'. `prev' will never be the same as `next'.
*
* We just delegate everything to the __switch_to assembly function,
* which is implemented in arch/avr32/kernel/switch_to.S
*
* mb() tells GCC not to cache `current' across this call.
*/
struct cpu_context;
struct task_struct;
extern struct task_struct *__switch_to(struct task_struct *,
struct cpu_context *,
struct cpu_context *);
#define switch_to(prev, next, last) \
do { \
last = __switch_to(prev, &prev->thread.cpu_context + 1, \
&next->thread.cpu_context); \
} while (0)
#ifdef CONFIG_SMP
# error "The AVR32 port does not support SMP"
#else
# define smp_mb() barrier()
# define smp_rmb() barrier()
# define smp_wmb() barrier()
# define smp_read_barrier_depends() do { } while(0)
#endif
#include <linux/irqflags.h>
extern void __xchg_called_with_bad_pointer(void);
static inline unsigned long xchg_u32(u32 val, volatile u32 *m)
{
u32 ret;
asm volatile("xchg %[ret], %[m], %[val]"
: [ret] "=&r"(ret), "=m"(*m)
: "m"(*m), [m] "r"(m), [val] "r"(val)
: "memory");
return ret;
}
static inline unsigned long __xchg(unsigned long x,
volatile void *ptr,
int size)
{
switch(size) {
case 4:
return xchg_u32(x, ptr);
default:
__xchg_called_with_bad_pointer();
return x;
}
}
static inline unsigned long __cmpxchg_u32(volatile int *m, unsigned long old,
unsigned long new)
{
__u32 ret;
asm volatile(
"1: ssrf 5\n"
" ld.w %[ret], %[m]\n"
" cp.w %[ret], %[old]\n"
" brne 2f\n"
" stcond %[m], %[new]\n"
" brne 1b\n"
"2:\n"
: [ret] "=&r"(ret), [m] "=m"(*m)
: "m"(m), [old] "ir"(old), [new] "r"(new)
: "memory", "cc");
return ret;
}
extern unsigned long __cmpxchg_u64_unsupported_on_32bit_kernels(
volatile int * m, unsigned long old, unsigned long new);
#define __cmpxchg_u64 __cmpxchg_u64_unsupported_on_32bit_kernels
/* This function doesn't exist, so you'll get a linker error
if something tries to do an invalid cmpxchg(). */
extern void __cmpxchg_called_with_bad_pointer(void);
#define __HAVE_ARCH_CMPXCHG 1
static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
unsigned long new, int size)
{
switch (size) {
case 4:
return __cmpxchg_u32(ptr, old, new);
case 8:
return __cmpxchg_u64(ptr, old, new);
}
__cmpxchg_called_with_bad_pointer();
return old;
}
#define cmpxchg(ptr, old, new) \
((typeof(*(ptr)))__cmpxchg((ptr), (unsigned long)(old), \
(unsigned long)(new), \
sizeof(*(ptr))))
struct pt_regs;
void NORET_TYPE die(const char *str, struct pt_regs *regs, long err);
void _exception(long signr, struct pt_regs *regs, int code,
unsigned long addr);
#define arch_align_stack(x) (x)
#endif /* __ASM_AVR32_SYSTEM_H */
