Messages in this thread Patch in this message | | | From | Leonardo Bras <> | Subject | [RFC PATCH 1/6] riscv/cmpxchg: Deduplicate cmpxchg() asm functions | Date | Sat, 18 Mar 2023 05:00:55 -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.
(This did not cause any change in generated asm)
Signed-off-by: Leonardo Bras <leobras@redhat.com> --- arch/riscv/include/asm/cmpxchg.h | 102 ++++++++----------------------- 1 file changed, 24 insertions(+), 78 deletions(-)
diff --git a/arch/riscv/include/asm/cmpxchg.h b/arch/riscv/include/asm/cmpxchg.h index 12debce235e52..21984d24cbfe7 100644 --- a/arch/riscv/include/asm/cmpxchg.h +++ b/arch/riscv/include/asm/cmpxchg.h @@ -163,6 +163,22 @@ * store NEW in MEM. Return the initial value in MEM. Success is * indicated by comparing RETURN with OLD. */ + +#define ___cmpxchg(lr_sfx, sc_sfx, prepend, append) \ +{ \ + __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" (__ret), "=&r" (__rc), "+A" (*__ptr) \ + : "rJ" ((long)__old), "rJ" (__new) \ + : "memory"); \ +} + #define __cmpxchg_relaxed(ptr, old, new, size) \ ({ \ __typeof__(ptr) __ptr = (ptr); \ @@ -172,26 +188,10 @@ 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"); \ + ___cmpxchg(".w", ".w", "", ""); \ 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"); \ + ___cmpxchg(".d", ".d", "", ""); \ break; \ default: \ BUILD_BUG(); \ @@ -216,28 +216,10 @@ 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"); \ + ___cmpxchg(".w", ".w", "", RISCV_ACQUIRE_BARRIER); \ 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"); \ + ___cmpxchg(".d", ".d", "", RISCV_ACQUIRE_BARRIER); \ break; \ default: \ BUILD_BUG(); \ @@ -262,28 +244,10 @@ 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"); \ + ___cmpxchg(".w", ".w", RISCV_RELEASE_BARRIER, ""); \ 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"); \ + ___cmpxchg(".d", ".d", RISCV_RELEASE_BARRIER, ""); \ break; \ default: \ BUILD_BUG(); \ @@ -308,28 +272,10 @@ 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"); \ + ___cmpxchg(".w", ".w.rl", "", " fence rw, rw\n"); \ 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"); \ + ___cmpxchg(".d", ".d.rl", "", " fence rw, rw\n"); \ break; \ default: \ BUILD_BUG(); \ -- 2.40.0
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