Messages in this thread Patch in this message | | | From | Leonardo Bras <> | Subject | [RFC PATCH v3 2/5] riscv/cmpxchg: Deduplicate cmpxchg() asm and macros | Date | Fri, 4 Aug 2023 05:48:55 -0300 |
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In this header every cmpxchg 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_cmpxchg* generation
(This did not cause any change in generated asm)
Signed-off-by: Leonardo Bras <leobras@redhat.com> Reviewed-by: Andrea Parri <parri.andrea@gmail.com> --- arch/riscv/include/asm/cmpxchg.h | 187 +++++-------------------------- 1 file changed, 29 insertions(+), 158 deletions(-)
diff --git a/arch/riscv/include/asm/cmpxchg.h b/arch/riscv/include/asm/cmpxchg.h index ec4ea4f3f908..5a07646fae65 100644 --- a/arch/riscv/include/asm/cmpxchg.h +++ b/arch/riscv/include/asm/cmpxchg.h @@ -71,127 +71,40 @@ * store NEW in MEM. Return the initial value in MEM. Success is * indicated by comparing RETURN with OLD. */ -#define __cmpxchg_relaxed(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__ ( \ - "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__ ( \ - "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_relaxed(ptr, o, n) \ -({ \ - __typeof__(*(ptr)) _o_ = (o); \ - __typeof__(*(ptr)) _n_ = (n); \ - (__typeof__(*(ptr))) __cmpxchg_relaxed((ptr), \ - _o_, _n_, sizeof(*(ptr))); \ -}) -#define __cmpxchg_acquire(ptr, old, new, size) \ +#define __arch_cmpxchg(lr_sfx, sc_sfx, prepend, append, r, p, co, o, n) \ ({ \ - __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__ ( \ - "0: lr.w %0, %2\n" \ - " bne %0, %z3, 1f\n" \ - " sc.w %1, %z4, %2\n" \ - " bnez %1, 0b\n" \ - RISCV_ACQUIRE_BARRIER \ - "1:\n" \ - : "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr) \ - : "rJ" ((long)__old), "rJ" (__new) \ - : "memory"); \ - break; \ - case 8: \ - __asm__ __volatile__ ( \ - "0: lr.d %0, %2\n" \ - " bne %0, %z3, 1f\n" \ - " sc.d %1, %z4, %2\n" \ - " bnez %1, 0b\n" \ - RISCV_ACQUIRE_BARRIER \ - "1:\n" \ - : "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr) \ - : "rJ" (__old), "rJ" (__new) \ - : "memory"); \ - break; \ - default: \ - BUILD_BUG(); \ - } \ - __ret; \ -}) - -#define arch_cmpxchg_acquire(ptr, o, n) \ -({ \ - __typeof__(*(ptr)) _o_ = (o); \ - __typeof__(*(ptr)) _n_ = (n); \ - (__typeof__(*(ptr))) __cmpxchg_acquire((ptr), \ - _o_, _n_, sizeof(*(ptr))); \ + \ + __asm__ __volatile__ ( \ + prepend \ + "0: lr" lr_sfx " %0, %2\n" \ + " bne %0, %z3, 1f\n" \ + " sc" sc_sfx " %1, %z4, %2\n" \ + " bnez %1, 0b\n" \ + append \ + "1:\n" \ + : "=&r" (r), "=&r" (__rc), "+A" (*(p)) \ + : "rJ" (co o), "rJ" (n) \ + : "memory"); \ }) -#define __cmpxchg_release(ptr, old, new, size) \ +#define _arch_cmpxchg(ptr, old, new, sc_sfx, prepend, append) \ ({ \ __typeof__(ptr) __ptr = (ptr); \ __typeof__(*(ptr)) __old = (old); \ __typeof__(*(ptr)) __new = (new); \ __typeof__(*(ptr)) __ret; \ - register unsigned int __rc; \ - switch (size) { \ + \ + switch (sizeof(*__ptr)) { \ 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"); \ + __arch_cmpxchg(".w", ".w" sc_sfx, prepend, append, \ + __ret, __ptr, (long), __old, __new); \ 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"); \ + __arch_cmpxchg(".d", ".d" sc_sfx, prepend, append, \ + __ret, __ptr, /**/, __old, __new); \ break; \ default: \ BUILD_BUG(); \ @@ -199,62 +112,20 @@ __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 arch_cmpxchg_relaxed(ptr, o, n) \ + _arch_cmpxchg((ptr), (o), (n), "", "", "") -#define __cmpxchg(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__ ( \ - "0: lr.w %0, %2\n" \ - " bne %0, %z3, 1f\n" \ - " sc.w.rl %1, %z4, %2\n" \ - " bnez %1, 0b\n" \ - " fence rw, rw\n" \ - "1:\n" \ - : "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr) \ - : "rJ" ((long)__old), "rJ" (__new) \ - : "memory"); \ - break; \ - case 8: \ - __asm__ __volatile__ ( \ - "0: lr.d %0, %2\n" \ - " bne %0, %z3, 1f\n" \ - " sc.d.rl %1, %z4, %2\n" \ - " bnez %1, 0b\n" \ - " fence rw, rw\n" \ - "1:\n" \ - : "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr) \ - : "rJ" (__old), "rJ" (__new) \ - : "memory"); \ - break; \ - default: \ - BUILD_BUG(); \ - } \ - __ret; \ -}) +#define arch_cmpxchg_acquire(ptr, o, n) \ + _arch_cmpxchg((ptr), (o), (n), "", "", RISCV_ACQUIRE_BARRIER) + +#define arch_cmpxchg_release(ptr, o, n) \ + _arch_cmpxchg((ptr), (o), (n), "", RISCV_RELEASE_BARRIER, "") #define arch_cmpxchg(ptr, o, n) \ -({ \ - __typeof__(*(ptr)) _o_ = (o); \ - __typeof__(*(ptr)) _n_ = (n); \ - (__typeof__(*(ptr))) __cmpxchg((ptr), \ - _o_, _n_, sizeof(*(ptr))); \ -}) + _arch_cmpxchg((ptr), (o), (n), ".rl", "", " fence rw, rw\n") #define arch_cmpxchg_local(ptr, o, n) \ - (__cmpxchg_relaxed((ptr), (o), (n), sizeof(*(ptr)))) + arch_cmpxchg_relaxed((ptr), (o), (n)) #define arch_cmpxchg64(ptr, o, n) \ ({ \ -- 2.41.0
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