[PATCH v5 3/3] riscv: atomic: Clean up unnecessary acquire and release definitions
Xianting Tian
xianting.tian at linux.alibaba.com
Fri Jul 1 05:05:48 PDT 2022
From: Guo Ren <guoren at linux.alibaba.com>
Clean up unnecessary xchg_acquire, xchg_release, and cmpxchg_release
custom definitions, because the generic implementation is the same as
the riscv custom implementation.
Before the patch:
000000000000024e <.LBB238>:
ops = xchg_acquire(pending_ipis, 0);
24e: 089937af amoswap.d a5,s1,(s2)
252: 0230000f fence r,rw
0000000000000256 <.LBB243>:
ops = xchg_release(pending_ipis, 0);
256: 0310000f fence rw,w
25a: 089934af amoswap.d s1,s1,(s2)
After the patch:
000000000000026e <.LBB245>:
ops = xchg_acquire(pending_ipis, 0);
26e: 089937af amoswap.d a5,s1,(s2)
0000000000000272 <.LBE247>:
272: 0230000f fence r,rw
0000000000000276 <.LBB249>:
ops = xchg_release(pending_ipis, 0);
276: 0310000f fence rw,w
000000000000027a <.LBB251>:
27a: 089934af amoswap.d s1,s1,(s2)
Only cmpxchg_acquire is necessary (It prevents unnecessary acquire
ordering when the value from lr is different from old).
Signed-off-by: Guo Ren <guoren at linux.alibaba.com>
Signed-off-by: Guo Ren <guoren at kernel.org>
Cc: Arnd Bergmann <arnd at arndb.de>
Cc: Palmer Dabbelt <palmer at dabbelt.com>
---
arch/riscv/include/asm/atomic.h | 19 -----
arch/riscv/include/asm/cmpxchg.h | 116 -------------------------------
2 files changed, 135 deletions(-)
diff --git a/arch/riscv/include/asm/atomic.h b/arch/riscv/include/asm/atomic.h
index 0dfe9d857a76..83636320ba95 100644
--- a/arch/riscv/include/asm/atomic.h
+++ b/arch/riscv/include/asm/atomic.h
@@ -249,16 +249,6 @@ c_t arch_atomic##prefix##_xchg_relaxed(atomic##prefix##_t *v, c_t n) \
return __xchg_relaxed(&(v->counter), n, size); \
} \
static __always_inline \
-c_t arch_atomic##prefix##_xchg_acquire(atomic##prefix##_t *v, c_t n) \
-{ \
- return __xchg_acquire(&(v->counter), n, size); \
-} \
-static __always_inline \
-c_t arch_atomic##prefix##_xchg_release(atomic##prefix##_t *v, c_t n) \
-{ \
- return __xchg_release(&(v->counter), n, size); \
-} \
-static __always_inline \
c_t arch_atomic##prefix##_xchg(atomic##prefix##_t *v, c_t n) \
{ \
return __xchg(&(v->counter), n, size); \
@@ -276,12 +266,6 @@ c_t arch_atomic##prefix##_cmpxchg_acquire(atomic##prefix##_t *v, \
return __cmpxchg_acquire(&(v->counter), o, n, size); \
} \
static __always_inline \
-c_t arch_atomic##prefix##_cmpxchg_release(atomic##prefix##_t *v, \
- c_t o, c_t n) \
-{ \
- return __cmpxchg_release(&(v->counter), o, n, size); \
-} \
-static __always_inline \
c_t arch_atomic##prefix##_cmpxchg(atomic##prefix##_t *v, c_t o, c_t n) \
{ \
return __cmpxchg(&(v->counter), o, n, size); \
@@ -299,12 +283,9 @@ c_t arch_atomic##prefix##_cmpxchg(atomic##prefix##_t *v, c_t o, c_t n) \
ATOMIC_OPS()
#define arch_atomic_xchg_relaxed arch_atomic_xchg_relaxed
-#define arch_atomic_xchg_acquire arch_atomic_xchg_acquire
-#define arch_atomic_xchg_release arch_atomic_xchg_release
#define arch_atomic_xchg arch_atomic_xchg
#define arch_atomic_cmpxchg_relaxed arch_atomic_cmpxchg_relaxed
#define arch_atomic_cmpxchg_acquire arch_atomic_cmpxchg_acquire
-#define arch_atomic_cmpxchg_release arch_atomic_cmpxchg_release
#define arch_atomic_cmpxchg arch_atomic_cmpxchg
#undef ATOMIC_OPS
diff --git a/arch/riscv/include/asm/cmpxchg.h b/arch/riscv/include/asm/cmpxchg.h
index 12debce235e5..67ab6375b650 100644
--- a/arch/riscv/include/asm/cmpxchg.h
+++ b/arch/riscv/include/asm/cmpxchg.h
@@ -44,76 +44,6 @@
_x_, sizeof(*(ptr))); \
})
-#define __xchg_acquire(ptr, new, size) \
-({ \
- __typeof__(ptr) __ptr = (ptr); \
- __typeof__(new) __new = (new); \
- __typeof__(*(ptr)) __ret; \
- switch (size) { \
- case 4: \
- __asm__ __volatile__ ( \
- " amoswap.w %0, %2, %1\n" \
- RISCV_ACQUIRE_BARRIER \
- : "=r" (__ret), "+A" (*__ptr) \
- : "r" (__new) \
- : "memory"); \
- break; \
- case 8: \
- __asm__ __volatile__ ( \
- " amoswap.d %0, %2, %1\n" \
- RISCV_ACQUIRE_BARRIER \
- : "=r" (__ret), "+A" (*__ptr) \
- : "r" (__new) \
- : "memory"); \
- break; \
- default: \
- BUILD_BUG(); \
- } \
- __ret; \
-})
-
-#define arch_xchg_acquire(ptr, x) \
-({ \
- __typeof__(*(ptr)) _x_ = (x); \
- (__typeof__(*(ptr))) __xchg_acquire((ptr), \
- _x_, sizeof(*(ptr))); \
-})
-
-#define __xchg_release(ptr, new, size) \
-({ \
- __typeof__(ptr) __ptr = (ptr); \
- __typeof__(new) __new = (new); \
- __typeof__(*(ptr)) __ret; \
- switch (size) { \
- case 4: \
- __asm__ __volatile__ ( \
- RISCV_RELEASE_BARRIER \
- " amoswap.w %0, %2, %1\n" \
- : "=r" (__ret), "+A" (*__ptr) \
- : "r" (__new) \
- : "memory"); \
- break; \
- case 8: \
- __asm__ __volatile__ ( \
- RISCV_RELEASE_BARRIER \
- " amoswap.d %0, %2, %1\n" \
- : "=r" (__ret), "+A" (*__ptr) \
- : "r" (__new) \
- : "memory"); \
- break; \
- default: \
- BUILD_BUG(); \
- } \
- __ret; \
-})
-
-#define arch_xchg_release(ptr, x) \
-({ \
- __typeof__(*(ptr)) _x_ = (x); \
- (__typeof__(*(ptr))) __xchg_release((ptr), \
- _x_, sizeof(*(ptr))); \
-})
-
#define __xchg(ptr, new, size) \
({ \
__typeof__(ptr) __ptr = (ptr); \
@@ -253,52 +183,6 @@
_o_, _n_, sizeof(*(ptr))); \
})
-#define __cmpxchg_release(ptr, old, new, size) \
-({ \
- __typeof__(ptr) __ptr = (ptr); \
- __typeof__(*(ptr)) __old = (old); \
- __typeof__(*(ptr)) __new = (new); \
- __typeof__(*(ptr)) __ret; \
- register unsigned int __rc; \
- switch (size) { \
- case 4: \
- __asm__ __volatile__ ( \
- RISCV_RELEASE_BARRIER \
- "0: lr.w %0, %2\n" \
- " bne %0, %z3, 1f\n" \
- " sc.w %1, %z4, %2\n" \
- " bnez %1, 0b\n" \
- "1:\n" \
- : "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr) \
- : "rJ" ((long)__old), "rJ" (__new) \
- : "memory"); \
- break; \
- case 8: \
- __asm__ __volatile__ ( \
- RISCV_RELEASE_BARRIER \
- "0: lr.d %0, %2\n" \
- " bne %0, %z3, 1f\n" \
- " sc.d %1, %z4, %2\n" \
- " bnez %1, 0b\n" \
- "1:\n" \
- : "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr) \
- : "rJ" (__old), "rJ" (__new) \
- : "memory"); \
- break; \
- default: \
- BUILD_BUG(); \
- } \
- __ret; \
-})
-
-#define arch_cmpxchg_release(ptr, o, n) \
-({ \
- __typeof__(*(ptr)) _o_ = (o); \
- __typeof__(*(ptr)) _n_ = (n); \
- (__typeof__(*(ptr))) __cmpxchg_release((ptr), \
- _o_, _n_, sizeof(*(ptr))); \
-})
-
#define __cmpxchg(ptr, old, new, size) \
({ \
__typeof__(ptr) __ptr = (ptr); \
--
2.17.1
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