linux/include/asm-generic/cmpxchg.h
Paul Gortmaker 80da6a4fee asm-generic: add linux/types.h to cmpxchg.h
Builds of the openrisc or1ksim_defconfig show the following:

  In file included from arch/openrisc/include/generated/asm/cmpxchg.h:1:0,
                   from include/asm-generic/atomic.h:18,
                   from arch/openrisc/include/generated/asm/atomic.h:1,
                   from include/linux/atomic.h:4,
                   from include/linux/dcache.h:4,
                   from fs/notify/fsnotify.c:19:
  include/asm-generic/cmpxchg.h: In function '__xchg':
  include/asm-generic/cmpxchg.h:34:20: error: expected ')' before 'u8'
  include/asm-generic/cmpxchg.h:34:20: warning: type defaults to 'int' in type name

and many more lines of similar errors.  It seems specific to the or32
because most other platforms have an arch specific component that would
have already included types.h ahead of time, but the o32 does not.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jonas Bonn <jonas@southpole.se>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: David Howells <dhowells@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-04-02 14:41:27 -07:00

99 lines
2.0 KiB
C

/*
* Generic UP xchg and cmpxchg using interrupt disablement. Does not
* support SMP.
*/
#ifndef __ASM_GENERIC_CMPXCHG_H
#define __ASM_GENERIC_CMPXCHG_H
#ifdef CONFIG_SMP
#error "Cannot use generic cmpxchg on SMP"
#endif
#include <linux/types.h>
#include <linux/irqflags.h>
#ifndef xchg
/*
* This function doesn't exist, so you'll get a linker error if
* something tries to do an invalidly-sized 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))))
#endif /* xchg */
/*
* Atomic compare and exchange.
*
* Do not define __HAVE_ARCH_CMPXCHG because we want to use it to check whether
* a cmpxchg primitive faster than repeated local irq save/restore exists.
*/
#include <asm-generic/cmpxchg-local.h>
#define cmpxchg(ptr, o, n) cmpxchg_local((ptr), (o), (n))
#define cmpxchg64(ptr, o, n) cmpxchg64_local((ptr), (o), (n))
#endif /* __ASM_GENERIC_CMPXCHG_H */