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Message-Id: <20230406082018.70367-3-leobras@redhat.com>
Date: Thu, 6 Apr 2023 05:20:19 -0300
From: Leonardo Bras <leobras@...hat.com>
To: Paul Walmsley <paul.walmsley@...ive.com>,
Palmer Dabbelt <palmer@...belt.com>,
Albert Ou <aou@...s.berkeley.edu>,
Leonardo Bras <leobras@...hat.com>,
Guo Ren <guoren@...nel.org>,
Andrea Parri <parri.andrea@...il.com>,
Conor Dooley <conor.dooley@...rochip.com>
Cc: linux-riscv@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: [RFC PATCH v1 2/2] riscv/cmpxchg: Deduplicate xchg() asm functions
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@...hat.com>
---
arch/riscv/include/asm/cmpxchg.h | 135 +++++++------------------------
1 file changed, 31 insertions(+), 104 deletions(-)
diff --git a/arch/riscv/include/asm/cmpxchg.h b/arch/riscv/include/asm/cmpxchg.h
index f88fae357071c..905a888d8b04d 100644
--- a/arch/riscv/include/asm/cmpxchg.h
+++ b/arch/riscv/include/asm/cmpxchg.h
@@ -11,25 +11,30 @@
#include <asm/barrier.h>
#include <asm/fence.h>
-#define __xchg_relaxed(ptr, new, size) \
+#define ____xchg(sfx, prepend, append, r, p, n) \
+({ \
+ __asm__ __volatile__ ( \
+ prepend \
+ " amoswap" sfx " %0, %2, %1\n" \
+ append \
+ : "=r" (r), "+A" (*(p)) \
+ : "r" (n) \
+ : "memory"); \
+})
+
+#define ___xchg(ptr, new, size, sfx, prepend, append) \
({ \
__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"); \
+ ____xchg(".w" sfx, prepend, append, \
+ __ret, __ptr, __new); \
break; \
case 8: \
- __asm__ __volatile__ ( \
- " amoswap.d %0, %2, %1\n" \
- : "=r" (__ret), "+A" (*__ptr) \
- : "r" (__new) \
- : "memory"); \
+ ____xchg(".d" sfx, prepend, append, \
+ __ret, __ptr, __new); \
break; \
default: \
BUILD_BUG(); \
@@ -37,114 +42,36 @@
__ret; \
})
-#define arch_xchg_relaxed(ptr, x) \
+#define __xchg_relaxed(ptr, new, size) \
+ ___xchg(ptr, new, size, "", "", "")
+
+#define _arch_xchg(order, ptr, x) \
({ \
__typeof__(*(ptr)) _x_ = (x); \
- (__typeof__(*(ptr))) __xchg_relaxed((ptr), \
- _x_, sizeof(*(ptr))); \
+ (__typeof__(*(ptr))) __xchg ## order((ptr), \
+ _x_, sizeof(*(ptr))); \
})
+#define arch_xchg_relaxed(ptr, x) \
+ _arch_xchg(_relaxed, ptr, x)
+
#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; \
-})
+ ___xchg(ptr, new, size, "", "", RISCV_ACQUIRE_BARRIER)
#define arch_xchg_acquire(ptr, x) \
-({ \
- __typeof__(*(ptr)) _x_ = (x); \
- (__typeof__(*(ptr))) __xchg_acquire((ptr), \
- _x_, sizeof(*(ptr))); \
-})
+ _arch_xchg(_acquire, 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; \
-})
+ ___xchg(ptr, new, size, "", RISCV_RELEASE_BARRIER, "")
#define arch_xchg_release(ptr, x) \
-({ \
- __typeof__(*(ptr)) _x_ = (x); \
- (__typeof__(*(ptr))) __xchg_release((ptr), \
- _x_, sizeof(*(ptr))); \
-})
+ _arch_xchg(_release, ptr, x)
#define __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; \
-})
+ ___xchg(ptr, new, size, ".aqrl", "", "")
#define arch_xchg(ptr, x) \
-({ \
- __typeof__(*(ptr)) _x_ = (x); \
- (__typeof__(*(ptr))) __xchg((ptr), _x_, sizeof(*(ptr))); \
-})
+ _arch_xchg(, ptr, x)
#define xchg32(ptr, x) \
({ \
--
2.40.0
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