mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-16 04:27:36 +07:00
00c30e0681
asm/cmpxchg.h can be included on its own and needs to be self-consistent.
The definitions for the cmpxchg*_local macros, as such, need to be part
of this file.
This fixes a build issue on OpenRISC since the system.h smashing patch
96f951edb1 that introdued the direct inclusion
asm/cmpxchg.h into linux/llist.h.
CC: David Howells <dhowells@redhat.com>
Signed-off-by: Jonas Bonn <jonas@southpole.se>
Acked-by: Arnd Bergmann <arnd@arndb.de>
109 lines
2.3 KiB
C
109 lines
2.3 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>
|
|
|
|
#ifndef cmpxchg_local
|
|
#define cmpxchg_local(ptr, o, n) \
|
|
((__typeof__(*(ptr)))__cmpxchg_local_generic((ptr), (unsigned long)(o),\
|
|
(unsigned long)(n), sizeof(*(ptr))))
|
|
#endif
|
|
|
|
#ifndef cmpxchg64_local
|
|
#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
|
|
#endif
|
|
|
|
#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 */
|