diff options
| author |   Andreas Larsson <andreas@gaisler.com> | 2014-11-05 15:52:08 +0100 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2014-11-07 12:51:44 -0800 |
| commit | 1a17fdc4f4ed06b63fac1937470378a5441a663a (patch) | |
| tree | 1590a724b9a40458ba1a990ceb41fc51839196fc /arch/sparc/include/asm | |
| parent | sparc64: Do irq_{enter,exit}() around generic_smp_call_function*(). (diff) | |
| download | linux-dev-1a17fdc4f4ed06b63fac1937470378a5441a663a.tar.xz linux-dev-1a17fdc4f4ed06b63fac1937470378a5441a663a.zip | |
sparc32: Implement xchg and atomic_xchg using ATOMIC_HASH locks
Atomicity between xchg and cmpxchg cannot be guaranteed when xchg is
implemented with a swap and cmpxchg is implemented with locks.
Without this, e.g. mcs_spin_lock and mcs_spin_unlock are broken.
Signed-off-by: Andreas Larsson <andreas@gaisler.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/sparc/include/asm')
| -rw-r--r-- | arch/sparc/include/asm/atomic_32.h | 2 | ||||
| -rw-r--r-- | arch/sparc/include/asm/cmpxchg_32.h | 12 |
2 files changed, 3 insertions, 11 deletions
diff --git a/arch/sparc/include/asm/atomic_32.h b/arch/sparc/include/asm/atomic_32.h index 765c1776ec9f..0e69b7e7a439 100644 --- a/arch/sparc/include/asm/atomic_32.h +++ b/arch/sparc/include/asm/atomic_32.h @@ -22,7 +22,7 @@ int atomic_add_return(int, atomic_t *); int atomic_cmpxchg(atomic_t *, int, int); -#define atomic_xchg(v, new) (xchg(&((v)->counter), new)) +int atomic_xchg(atomic_t *, int); int __atomic_add_unless(atomic_t *, int, int); void atomic_set(atomic_t *, int); diff --git a/arch/sparc/include/asm/cmpxchg_32.h b/arch/sparc/include/asm/cmpxchg_32.h index 32c29a133f9d..d38b52dca216 100644 --- a/arch/sparc/include/asm/cmpxchg_32.h +++ b/arch/sparc/include/asm/cmpxchg_32.h @@ -11,22 +11,14 @@ #ifndef __ARCH_SPARC_CMPXCHG__ #define __ARCH_SPARC_CMPXCHG__ -static inline unsigned long xchg_u32(__volatile__ unsigned long *m, unsigned long val) -{ - __asm__ __volatile__("swap [%2], %0" - : "=&r" (val) - : "0" (val), "r" (m) - : "memory"); - return val; -} - +unsigned long __xchg_u32(volatile u32 *m, u32 new); 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); + return __xchg_u32(ptr, x); } __xchg_called_with_bad_pointer(); return x; |