[RFC PATCH v4 3/5] riscv/atomic.h : Deduplicate arch_atomic.*

[Leonardo Bras]

Some functions use mostly the same asm for 32-bit and 64-bit versions.

Make a macro that is generic enough and avoid code duplication.

(This did not cause any change in generated asm)

Signed-off-by: Leonardo Bras <leobras@xxxxxxxxxx>
Reviewed-by: Guo Ren <guoren@xxxxxxxxxx>
Reviewed-by: Andrea Parri <parri.andrea@xxxxxxxxx>
---
 arch/riscv/include/asm/atomic.h | 164 +++++++++++++++-----------------
 1 file changed, 76 insertions(+), 88 deletions(-)

diff --git a/arch/riscv/include/asm/atomic.h b/arch/riscv/include/asm/atomic.h
index f5dfef6c2153..80cca7ac16fd 100644
--- a/arch/riscv/include/asm/atomic.h
+++ b/arch/riscv/include/asm/atomic.h
@@ -196,22 +196,28 @@ ATOMIC_OPS(xor, xor, i)
 #undef ATOMIC_FETCH_OP
 #undef ATOMIC_OP_RETURN
 
+#define _arch_atomic_fetch_add_unless(_prev, _rc, counter, _a, _u, sfx)	\
+({									\
+	__asm__ __volatile__ (						\
+		"0:	lr." sfx "     %[p],  %[c]\n"			\
+		"	beq	       %[p],  %[u], 1f\n"		\
+		"	add            %[rc], %[p], %[a]\n"		\
+		"	sc." sfx ".rl  %[rc], %[rc], %[c]\n"		\
+		"	bnez           %[rc], 0b\n"			\
+		"	fence          rw, rw\n"			\
+		"1:\n"							\
+		: [p]"=&r" (_prev), [rc]"=&r" (_rc), [c]"+A" (counter)	\
+		: [a]"r" (_a), [u]"r" (_u)				\
+		: "memory");						\
+})
+
 /* This is required to provide a full barrier on success. */
 static __always_inline int arch_atomic_fetch_add_unless(atomic_t *v, int a, int u)
 {
        int prev, rc;
 
-	__asm__ __volatile__ (
-		"0:	lr.w     %[p],  %[c]\n"
-		"	beq      %[p],  %[u], 1f\n"
-		"	add      %[rc], %[p], %[a]\n"
-		"	sc.w.rl  %[rc], %[rc], %[c]\n"
-		"	bnez     %[rc], 0b\n"
-		"	fence    rw, rw\n"
-		"1:\n"
-		: [p]"=&r" (prev), [rc]"=&r" (rc), [c]"+A" (v->counter)
-		: [a]"r" (a), [u]"r" (u)
-		: "memory");
+	_arch_atomic_fetch_add_unless(prev, rc, v->counter, a, u, "w");
+
 	return prev;
 }
 #define arch_atomic_fetch_add_unless arch_atomic_fetch_add_unless
@@ -222,77 +228,86 @@ static __always_inline s64 arch_atomic64_fetch_add_unless(atomic64_t *v, s64 a,
        s64 prev;
        long rc;
 
-	__asm__ __volatile__ (
-		"0:	lr.d     %[p],  %[c]\n"
-		"	beq      %[p],  %[u], 1f\n"
-		"	add      %[rc], %[p], %[a]\n"
-		"	sc.d.rl  %[rc], %[rc], %[c]\n"
-		"	bnez     %[rc], 0b\n"
-		"	fence    rw, rw\n"
-		"1:\n"
-		: [p]"=&r" (prev), [rc]"=&r" (rc), [c]"+A" (v->counter)
-		: [a]"r" (a), [u]"r" (u)
-		: "memory");
+	_arch_atomic_fetch_add_unless(prev, rc, v->counter, a, u, "d");
+
 	return prev;
 }
 #define arch_atomic64_fetch_add_unless arch_atomic64_fetch_add_unless
 #endif
 
+#define _arch_atomic_inc_unless_negative(_prev, _rc, counter, sfx)	\
+({									\
+	__asm__ __volatile__ (						\
+		"0:	lr." sfx "      %[p],  %[c]\n"			\
+		"	bltz            %[p],  1f\n"			\
+		"	addi            %[rc], %[p], 1\n"		\
+		"	sc." sfx ".rl   %[rc], %[rc], %[c]\n"		\
+		"	bnez            %[rc], 0b\n"			\
+		"	fence           rw, rw\n"			\
+		"1:\n"							\
+		: [p]"=&r" (_prev), [rc]"=&r" (_rc), [c]"+A" (counter)	\
+		:							\
+		: "memory");						\
+})
+
 static __always_inline bool arch_atomic_inc_unless_negative(atomic_t *v)
 {
 	int prev, rc;
 
-	__asm__ __volatile__ (
-		"0:	lr.w      %[p],  %[c]\n"
-		"	bltz      %[p],  1f\n"
-		"	addi      %[rc], %[p], 1\n"
-		"	sc.w.rl   %[rc], %[rc], %[c]\n"
-		"	bnez      %[rc], 0b\n"
-		"	fence     rw, rw\n"
-		"1:\n"
-		: [p]"=&r" (prev), [rc]"=&r" (rc), [c]"+A" (v->counter)
-		:
-		: "memory");
+	_arch_atomic_inc_unless_negative(prev, rc, v->counter, "w");
+
 	return !(prev < 0);
 }
 
 #define arch_atomic_inc_unless_negative arch_atomic_inc_unless_negative
 
+#define _arch_atomic_dec_unless_positive(_prev, _rc, counter, sfx)	\
+({									\
+	__asm__ __volatile__ (						\
+		"0:	lr." sfx "      %[p],  %[c]\n"			\
+		"	bgtz            %[p],  1f\n"			\
+		"	addi            %[rc], %[p], -1\n"		\
+		"	sc." sfx ".rl   %[rc], %[rc], %[c]\n"		\
+		"	bnez            %[rc], 0b\n"			\
+		"	fence           rw, rw\n"			\
+		"1:\n"							\
+		: [p]"=&r" (_prev), [rc]"=&r" (_rc), [c]"+A" (counter)	\
+		:							\
+		: "memory");						\
+})
+
 static __always_inline bool arch_atomic_dec_unless_positive(atomic_t *v)
 {
 	int prev, rc;
 
-	__asm__ __volatile__ (
-		"0:	lr.w      %[p],  %[c]\n"
-		"	bgtz      %[p],  1f\n"
-		"	addi      %[rc], %[p], -1\n"
-		"	sc.w.rl   %[rc], %[rc], %[c]\n"
-		"	bnez      %[rc], 0b\n"
-		"	fence     rw, rw\n"
-		"1:\n"
-		: [p]"=&r" (prev), [rc]"=&r" (rc), [c]"+A" (v->counter)
-		:
-		: "memory");
+	_arch_atomic_dec_unless_positive(prev, rc, v->counter, "w");
+
 	return !(prev > 0);
 }
 
 #define arch_atomic_dec_unless_positive arch_atomic_dec_unless_positive
 
+#define _arch_atomic_dec_if_positive(_prev, _rc, counter, sfx)		\
+({									\
+	__asm__ __volatile__ (						\
+		"0:	lr." sfx "     %[p],  %[c]\n"			\
+		"	addi           %[rc], %[p], -1\n"		\
+		"	bltz           %[rc], 1f\n"			\
+		"	sc." sfx ".rl  %[rc], %[rc], %[c]\n"		\
+		"	bnez           %[rc], 0b\n"			\
+		"	fence          rw, rw\n"			\
+		"1:\n"							\
+		: [p]"=&r" (_prev), [rc]"=&r" (_rc), [c]"+A" (counter)	\
+		:							\
+		: "memory");						\
+})
+
 static __always_inline int arch_atomic_dec_if_positive(atomic_t *v)
 {
        int prev, rc;
 
-	__asm__ __volatile__ (
-		"0:	lr.w     %[p],  %[c]\n"
-		"	addi     %[rc], %[p], -1\n"
-		"	bltz     %[rc], 1f\n"
-		"	sc.w.rl  %[rc], %[rc], %[c]\n"
-		"	bnez     %[rc], 0b\n"
-		"	fence    rw, rw\n"
-		"1:\n"
-		: [p]"=&r" (prev), [rc]"=&r" (rc), [c]"+A" (v->counter)
-		:
-		: "memory");
+	_arch_atomic_dec_if_positive(prev, rc, v->counter, "w");
+
 	return prev - 1;
 }
 
@@ -304,17 +319,8 @@ static __always_inline bool arch_atomic64_inc_unless_negative(atomic64_t *v)
 	s64 prev;
 	long rc;
 
-	__asm__ __volatile__ (
-		"0:	lr.d      %[p],  %[c]\n"
-		"	bltz      %[p],  1f\n"
-		"	addi      %[rc], %[p], 1\n"
-		"	sc.d.rl   %[rc], %[rc], %[c]\n"
-		"	bnez      %[rc], 0b\n"
-		"	fence     rw, rw\n"
-		"1:\n"
-		: [p]"=&r" (prev), [rc]"=&r" (rc), [c]"+A" (v->counter)
-		:
-		: "memory");
+	_arch_atomic_inc_unless_negative(prev, rc, v->counter, "d");
+
 	return !(prev < 0);
 }
 
@@ -325,17 +331,8 @@ static __always_inline bool arch_atomic64_dec_unless_positive(atomic64_t *v)
 	s64 prev;
 	long rc;
 
-	__asm__ __volatile__ (
-		"0:	lr.d      %[p],  %[c]\n"
-		"	bgtz      %[p],  1f\n"
-		"	addi      %[rc], %[p], -1\n"
-		"	sc.d.rl   %[rc], %[rc], %[c]\n"
-		"	bnez      %[rc], 0b\n"
-		"	fence     rw, rw\n"
-		"1:\n"
-		: [p]"=&r" (prev), [rc]"=&r" (rc), [c]"+A" (v->counter)
-		:
-		: "memory");
+	_arch_atomic_dec_unless_positive(prev, rc, v->counter, "d");
+
 	return !(prev > 0);
 }
 
@@ -346,17 +343,8 @@ static __always_inline s64 arch_atomic64_dec_if_positive(atomic64_t *v)
        s64 prev;
        long rc;
 
-	__asm__ __volatile__ (
-		"0:	lr.d     %[p],  %[c]\n"
-		"	addi      %[rc], %[p], -1\n"
-		"	bltz     %[rc], 1f\n"
-		"	sc.d.rl  %[rc], %[rc], %[c]\n"
-		"	bnez     %[rc], 0b\n"
-		"	fence    rw, rw\n"
-		"1:\n"
-		: [p]"=&r" (prev), [rc]"=&r" (rc), [c]"+A" (v->counter)
-		:
-		: "memory");
+	_arch_atomic_dec_if_positive(prev, rc, v->counter, "d");
+
 	return prev - 1;
 }
 
-- 
2.41.0