linux/include/asm-xtensa/system.h
Steven Rostedt 52393ccc0a [PATCH] remove set_wmb - arch removal
set_wmb should not be used in the kernel because it just confuses the
code more and has no benefit.  Since it is not currently used in the
kernel this patch removes it so that new code does not include it.

All archs define set_wmb(var, value) to do { var = value; wmb(); }
while(0) except ia64 and sparc which use a mb() instead.  But this is
still moot since it is not used anyway.

Hasn't been tested on any archs but x86 and x86_64 (and only compiled
tested)

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-14 21:56:14 -07:00

233 lines
5.6 KiB
C

/*
* include/asm-xtensa/system.h
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2001 - 2005 Tensilica Inc.
*/
#ifndef _XTENSA_SYSTEM_H
#define _XTENSA_SYSTEM_H
#include <linux/stringify.h>
#include <asm/processor.h>
/* interrupt control */
#define local_save_flags(x) \
__asm__ __volatile__ ("rsr %0,"__stringify(PS) : "=a" (x));
#define local_irq_restore(x) do { \
__asm__ __volatile__ ("wsr %0, "__stringify(PS)" ; rsync" \
:: "a" (x) : "memory"); } while(0);
#define local_irq_save(x) do { \
__asm__ __volatile__ ("rsil %0, "__stringify(LOCKLEVEL) \
: "=a" (x) :: "memory");} while(0);
static inline void local_irq_disable(void)
{
unsigned long flags;
__asm__ __volatile__ ("rsil %0, "__stringify(LOCKLEVEL)
: "=a" (flags) :: "memory");
}
static inline void local_irq_enable(void)
{
unsigned long flags;
__asm__ __volatile__ ("rsil %0, 0" : "=a" (flags) :: "memory");
}
static inline int irqs_disabled(void)
{
unsigned long flags;
local_save_flags(flags);
return flags & 0xf;
}
#define RSR_CPENABLE(x) do { \
__asm__ __volatile__("rsr %0," __stringify(CPENABLE) : "=a" (x)); \
} while(0);
#define WSR_CPENABLE(x) do { \
__asm__ __volatile__("wsr %0," __stringify(CPENABLE)";rsync" \
:: "a" (x));} while(0);
#define clear_cpenable() __clear_cpenable()
static inline void __clear_cpenable(void)
{
#if XCHAL_HAVE_CP
unsigned long i = 0;
WSR_CPENABLE(i);
#endif
}
static inline void enable_coprocessor(int i)
{
#if XCHAL_HAVE_CP
int cp;
RSR_CPENABLE(cp);
cp |= 1 << i;
WSR_CPENABLE(cp);
#endif
}
static inline void disable_coprocessor(int i)
{
#if XCHAL_HAVE_CP
int cp;
RSR_CPENABLE(cp);
cp &= ~(1 << i);
WSR_CPENABLE(cp);
#endif
}
#define smp_read_barrier_depends() do { } while(0)
#define read_barrier_depends() do { } while(0)
#define mb() barrier()
#define rmb() mb()
#define wmb() mb()
#ifdef CONFIG_SMP
#error smp_* not defined
#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)
#if !defined (__ASSEMBLY__)
/* * switch_to(n) should switch tasks to task nr n, first
* checking that n isn't the current task, in which case it does nothing.
*/
extern void *_switch_to(void *last, void *next);
#endif /* __ASSEMBLY__ */
#define switch_to(prev,next,last) \
do { \
clear_cpenable(); \
(last) = _switch_to(prev, next); \
} while(0)
/*
* cmpxchg
*/
static inline unsigned long
__cmpxchg_u32(volatile int *p, int old, int new)
{
__asm__ __volatile__("rsil a15, "__stringify(LOCKLEVEL)"\n\t"
"l32i %0, %1, 0 \n\t"
"bne %0, %2, 1f \n\t"
"s32i %3, %1, 0 \n\t"
"1: \n\t"
"wsr a15, "__stringify(PS)" \n\t"
"rsync \n\t"
: "=&a" (old)
: "a" (p), "a" (old), "r" (new)
: "a15", "memory");
return old;
}
/* 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);
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);
default: __cmpxchg_called_with_bad_pointer();
return old;
}
}
#define cmpxchg(ptr,o,n) \
({ __typeof__(*(ptr)) _o_ = (o); \
__typeof__(*(ptr)) _n_ = (n); \
(__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \
(unsigned long)_n_, sizeof (*(ptr))); \
})
/*
* xchg_u32
*
* Note that a15 is used here because the register allocation
* done by the compiler is not guaranteed and a window overflow
* may not occur between the rsil and wsr instructions. By using
* a15 in the rsil, the machine is guaranteed to be in a state
* where no register reference will cause an overflow.
*/
static inline unsigned long xchg_u32(volatile int * m, unsigned long val)
{
unsigned long tmp;
__asm__ __volatile__("rsil a15, "__stringify(LOCKLEVEL)"\n\t"
"l32i %0, %1, 0 \n\t"
"s32i %2, %1, 0 \n\t"
"wsr a15, "__stringify(PS)" \n\t"
"rsync \n\t"
: "=&a" (tmp)
: "a" (m), "a" (val)
: "a15", "memory");
return tmp;
}
#define tas(ptr) (xchg((ptr),1))
#define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
/*
* This only works if the compiler isn't horribly bad at optimizing.
* gcc-2.5.8 reportedly can't handle this, but I define that one to
* be dead anyway.
*/
extern void __xchg_called_with_bad_pointer(void);
static __inline__ unsigned long
__xchg(unsigned long x, volatile void * ptr, int size)
{
switch (size) {
case 4:
return xchg_u32(ptr, x);
}
__xchg_called_with_bad_pointer();
return x;
}
extern void set_except_vector(int n, void *addr);
static inline void spill_registers(void)
{
unsigned int a0, ps;
__asm__ __volatile__ (
"movi a14," __stringify (PS_EXCM_MASK) " | 1\n\t"
"mov a12, a0\n\t"
"rsr a13," __stringify(SAR) "\n\t"
"xsr a14," __stringify(PS) "\n\t"
"movi a0, _spill_registers\n\t"
"rsync\n\t"
"callx0 a0\n\t"
"mov a0, a12\n\t"
"wsr a13," __stringify(SAR) "\n\t"
"wsr a14," __stringify(PS) "\n\t"
:: "a" (&a0), "a" (&ps)
: "a2", "a3", "a12", "a13", "a14", "a15", "memory");
}
#define arch_align_stack(x) (x)
#endif /* _XTENSA_SYSTEM_H */