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| author |   Max Filippov <jcmvbkbc@gmail.com> | 2018-12-20 17:18:12 -0800 |
|---|---|---|
| committer | Max Filippov <jcmvbkbc@gmail.com> | 2019-05-07 10:36:31 -0700 |
| commit | f7c34874f04a80d6c39a32f08da2529e59602d3c (patch) | |
| tree | a225ab153205701d24bee7423fc950a9009cb533 /arch/xtensa/include/asm/atomic.h | |
| parent | xtensa: clean up inline assembly in futex.h (diff) | |
| download | linux-dev-f7c34874f04a80d6c39a32f08da2529e59602d3c.tar.xz linux-dev-f7c34874f04a80d6c39a32f08da2529e59602d3c.zip | |
xtensa: add exclusive atomics support
Implement atomic primitives using exclusive access opcodes available in
the recent xtensa cores.
Since l32ex/s32ex don't have any memory ordering guarantees don't define
__smp_mb__before_atomic/__smp_mb__after_atomic to make them use memw.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Diffstat (limited to 'arch/xtensa/include/asm/atomic.h')
| -rw-r--r-- | arch/xtensa/include/asm/atomic.h | 62 |
1 files changed, 61 insertions, 1 deletions
diff --git a/arch/xtensa/include/asm/atomic.h b/arch/xtensa/include/asm/atomic.h index 4e7311f58ae8..7b00d26f472e 100644 --- a/arch/xtensa/include/asm/atomic.h +++ b/arch/xtensa/include/asm/atomic.h @@ -56,7 +56,67 @@ */ #define atomic_set(v,i) WRITE_ONCE((v)->counter, (i)) -#if XCHAL_HAVE_S32C1I +#if XCHAL_HAVE_EXCLUSIVE +#define ATOMIC_OP(op) \ +static inline void atomic_##op(int i, atomic_t *v) \ +{ \ + unsigned long tmp; \ + int result; \ + \ + __asm__ __volatile__( \ + "1: l32ex %1, %3\n" \ + " " #op " %0, %1, %2\n" \ + " s32ex %0, %3\n" \ + " getex %0\n" \ + " beqz %0, 1b\n" \ + : "=&a" (result), "=&a" (tmp) \ + : "a" (i), "a" (v) \ + : "memory" \ + ); \ +} \ + +#define ATOMIC_OP_RETURN(op) \ +static inline int atomic_##op##_return(int i, atomic_t *v) \ +{ \ + unsigned long tmp; \ + int result; \ + \ + __asm__ __volatile__( \ + "1: l32ex %1, %3\n" \ + " " #op " %0, %1, %2\n" \ + " s32ex %0, %3\n" \ + " getex %0\n" \ + " beqz %0, 1b\n" \ + " " #op " %0, %1, %2\n" \ + : "=&a" (result), "=&a" (tmp) \ + : "a" (i), "a" (v) \ + : "memory" \ + ); \ + \ + return result; \ +} + +#define ATOMIC_FETCH_OP(op) \ +static inline int atomic_fetch_##op(int i, atomic_t *v) \ +{ \ + unsigned long tmp; \ + int result; \ + \ + __asm__ __volatile__( \ + "1: l32ex %1, %3\n" \ + " " #op " %0, %1, %2\n" \ + " s32ex %0, %3\n" \ + " getex %0\n" \ + " beqz %0, 1b\n" \ + : "=&a" (result), "=&a" (tmp) \ + : "a" (i), "a" (v) \ + : "memory" \ + ); \ + \ + return tmp; \ +} + +#elif XCHAL_HAVE_S32C1I #define ATOMIC_OP(op) \ static inline void atomic_##op(int i, atomic_t * v) \ { \ |