Messages in this thread Patch in this message | | | From | Leonardo Bras <> | Subject | [RFC PATCH v2 1/3] riscv/cmpxchg: Deduplicate xchg() asm functions | Date | Thu, 3 Aug 2023 02:13:58 -0300 |
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In this header every xchg define (_relaxed, _acquire, _release, vanilla) contain it's own asm file, both for 4-byte variables an 8-byte variables, on a total of 8 versions of mostly the same asm.
This is usually bad, as it means any change may be done in up to 8 different places.
Unify those versions by creating a new define with enough parameters to generate any version of the previous 8.
Then unify the result under a more general define, and simplify arch_xchg* generation.
(This did not cause any change in generated asm)
Signed-off-by: Leonardo Bras <leobras@redhat.com> --- arch/riscv/include/asm/cmpxchg.h | 136 +++++-------------------------- 1 file changed, 22 insertions(+), 114 deletions(-)
diff --git a/arch/riscv/include/asm/cmpxchg.h b/arch/riscv/include/asm/cmpxchg.h index 2f4726d3cfcc..ec4ea4f3f908 100644 --- a/arch/riscv/include/asm/cmpxchg.h +++ b/arch/riscv/include/asm/cmpxchg.h @@ -11,60 +11,30 @@ #include <asm/barrier.h> #include <asm/fence.h> -#define __xchg_relaxed(ptr, new, size) \ +#define __arch_xchg(sfx, prepend, append, r, p, n) \ ({ \ - __typeof__(ptr) __ptr = (ptr); \ - __typeof__(new) __new = (new); \ - __typeof__(*(ptr)) __ret; \ - switch (size) { \ - case 4: \ - __asm__ __volatile__ ( \ - " amoswap.w %0, %2, %1\n" \ - : "=r" (__ret), "+A" (*__ptr) \ - : "r" (__new) \ - : "memory"); \ - break; \ - case 8: \ - __asm__ __volatile__ ( \ - " amoswap.d %0, %2, %1\n" \ - : "=r" (__ret), "+A" (*__ptr) \ - : "r" (__new) \ - : "memory"); \ - break; \ - default: \ - BUILD_BUG(); \ - } \ - __ret; \ -}) - -#define arch_xchg_relaxed(ptr, x) \ -({ \ - __typeof__(*(ptr)) _x_ = (x); \ - (__typeof__(*(ptr))) __xchg_relaxed((ptr), \ - _x_, sizeof(*(ptr))); \ + __asm__ __volatile__ ( \ + prepend \ + " amoswap" sfx " %0, %2, %1\n" \ + append \ + : "=r" (r), "+A" (*(p)) \ + : "r" (n) \ + : "memory"); \ }) -#define __xchg_acquire(ptr, new, size) \ +#define _arch_xchg(ptr, new, sfx, prepend, append) \ ({ \ - __typeof__(ptr) __ptr = (ptr); \ - __typeof__(new) __new = (new); \ + __typeof__(*(ptr)) __new = (new); \ __typeof__(*(ptr)) __ret; \ - switch (size) { \ + __typeof__(ptr) __ptr = (ptr); \ + switch (sizeof(*__ptr)) { \ case 4: \ - __asm__ __volatile__ ( \ - " amoswap.w %0, %2, %1\n" \ - RISCV_ACQUIRE_BARRIER \ - : "=r" (__ret), "+A" (*__ptr) \ - : "r" (__new) \ - : "memory"); \ + __arch_xchg(".w" sfx, prepend, append, \ + __ret, __ptr, __new); \ break; \ case 8: \ - __asm__ __volatile__ ( \ - " amoswap.d %0, %2, %1\n" \ - RISCV_ACQUIRE_BARRIER \ - : "=r" (__ret), "+A" (*__ptr) \ - : "r" (__new) \ - : "memory"); \ + __arch_xchg(".d" sfx, prepend, append, \ + __ret, __ptr, __new); \ break; \ default: \ BUILD_BUG(); \ @@ -72,79 +42,17 @@ __ret; \ }) -#define arch_xchg_acquire(ptr, x) \ -({ \ - __typeof__(*(ptr)) _x_ = (x); \ - (__typeof__(*(ptr))) __xchg_acquire((ptr), \ - _x_, sizeof(*(ptr))); \ -}) +#define arch_xchg_relaxed(ptr, x) \ + _arch_xchg(ptr, x, "", "", "") -#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_acquire(ptr, x) \ + _arch_xchg(ptr, x, "", "", RISCV_ACQUIRE_BARRIER) #define arch_xchg_release(ptr, x) \ -({ \ - __typeof__(*(ptr)) _x_ = (x); \ - (__typeof__(*(ptr))) __xchg_release((ptr), \ - _x_, sizeof(*(ptr))); \ -}) - -#define __arch_xchg(ptr, new, size) \ -({ \ - __typeof__(ptr) __ptr = (ptr); \ - __typeof__(new) __new = (new); \ - __typeof__(*(ptr)) __ret; \ - switch (size) { \ - case 4: \ - __asm__ __volatile__ ( \ - " amoswap.w.aqrl %0, %2, %1\n" \ - : "=r" (__ret), "+A" (*__ptr) \ - : "r" (__new) \ - : "memory"); \ - break; \ - case 8: \ - __asm__ __volatile__ ( \ - " amoswap.d.aqrl %0, %2, %1\n" \ - : "=r" (__ret), "+A" (*__ptr) \ - : "r" (__new) \ - : "memory"); \ - break; \ - default: \ - BUILD_BUG(); \ - } \ - __ret; \ -}) + _arch_xchg(ptr, x, "", RISCV_RELEASE_BARRIER, "") #define arch_xchg(ptr, x) \ -({ \ - __typeof__(*(ptr)) _x_ = (x); \ - (__typeof__(*(ptr))) __arch_xchg((ptr), _x_, sizeof(*(ptr))); \ -}) + _arch_xchg(ptr, x, ".aqrl", "", "") #define xchg32(ptr, x) \ ({ \ -- 2.41.0
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