locking/atomic: riscv: move to ARCH_ATOMIC

We'd like all architectures to convert to ARCH_ATOMIC, as once all
architectures are converted it will be possible to make significant
cleanups to the atomics headers, and this will make it much easier to
generically enable atomic functionality (e.g. debug logic in the
instrumented wrappers).

As a step towards that, this patch migrates riscv to ARCH_ATOMIC. The
arch code provides arch_{atomic,atomic64,xchg,cmpxchg}*(), and common
code wraps these with optional instrumentation to provide the regular
functions.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210525140232.53872-29-mark.rutland@arm.com

arch/riscv/Kconfig

@@ -12,6 +12,7 @@ config 32BIT
 
 config RISCV
 	def_bool y
+	select ARCH_ATOMIC
 	select ARCH_CLOCKSOURCE_INIT
 	select ARCH_SUPPORTS_ATOMIC_RMW
 	select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU

arch/riscv/include/asm/cmpxchg.h

@@ -37,7 +37,7 @@
 	__ret;								\
 })
 
-#define xchg_relaxed(ptr, x)						\
+#define arch_xchg_relaxed(ptr, x)					\
 ({									\
 	__typeof__(*(ptr)) _x_ = (x);					\
 	(__typeof__(*(ptr))) __xchg_relaxed((ptr),			\
@@ -72,7 +72,7 @@
 	__ret;								\
 })
 
-#define xchg_acquire(ptr, x)						\
+#define arch_xchg_acquire(ptr, x)					\
 ({									\
 	__typeof__(*(ptr)) _x_ = (x);					\
 	(__typeof__(*(ptr))) __xchg_acquire((ptr),			\
@@ -107,7 +107,7 @@
 	__ret;								\
 })
 
-#define xchg_release(ptr, x)						\
+#define arch_xchg_release(ptr, x)					\
 ({									\
 	__typeof__(*(ptr)) _x_ = (x);					\
 	(__typeof__(*(ptr))) __xchg_release((ptr),			\
@@ -140,7 +140,7 @@
 	__ret;								\
 })
 
-#define xchg(ptr, x)							\
+#define arch_xchg(ptr, x)						\
 ({									\
 	__typeof__(*(ptr)) _x_ = (x);					\
 	(__typeof__(*(ptr))) __xchg((ptr), _x_, sizeof(*(ptr)));	\
@@ -149,13 +149,13 @@
 #define xchg32(ptr, x)							\
 ({									\
 	BUILD_BUG_ON(sizeof(*(ptr)) != 4);				\
-	xchg((ptr), (x));						\
+	arch_xchg((ptr), (x));						\
 })
 
 #define xchg64(ptr, x)							\
 ({									\
 	BUILD_BUG_ON(sizeof(*(ptr)) != 8);				\
-	xchg((ptr), (x));						\
+	arch_xchg((ptr), (x));						\
 })
 
 /*
@@ -199,7 +199,7 @@
 	__ret;								\
 })
 
-#define cmpxchg_relaxed(ptr, o, n)					\
+#define arch_cmpxchg_relaxed(ptr, o, n)					\
 ({									\
 	__typeof__(*(ptr)) _o_ = (o);					\
 	__typeof__(*(ptr)) _n_ = (n);					\
@@ -245,7 +245,7 @@
 	__ret;								\
 })
 
-#define cmpxchg_acquire(ptr, o, n)					\
+#define arch_cmpxchg_acquire(ptr, o, n)					\
 ({									\
 	__typeof__(*(ptr)) _o_ = (o);					\
 	__typeof__(*(ptr)) _n_ = (n);					\
@@ -291,7 +291,7 @@
 	__ret;								\
 })
 
-#define cmpxchg_release(ptr, o, n)					\
+#define arch_cmpxchg_release(ptr, o, n)					\
 ({									\
 	__typeof__(*(ptr)) _o_ = (o);					\
 	__typeof__(*(ptr)) _n_ = (n);					\
@@ -337,7 +337,7 @@
 	__ret;								\
 })
 
-#define cmpxchg(ptr, o, n)						\
+#define arch_cmpxchg(ptr, o, n)						\
 ({									\
 	__typeof__(*(ptr)) _o_ = (o);					\
 	__typeof__(*(ptr)) _n_ = (n);					\
@@ -345,31 +345,31 @@
 				       _o_, _n_, sizeof(*(ptr)));	\
 })
 
-#define cmpxchg_local(ptr, o, n)					\
+#define arch_cmpxchg_local(ptr, o, n)					\
 	(__cmpxchg_relaxed((ptr), (o), (n), sizeof(*(ptr))))
 
 #define cmpxchg32(ptr, o, n)						\
 ({									\
 	BUILD_BUG_ON(sizeof(*(ptr)) != 4);				\
-	cmpxchg((ptr), (o), (n));					\
+	arch_cmpxchg((ptr), (o), (n));					\
 })
 
 #define cmpxchg32_local(ptr, o, n)					\
 ({									\
 	BUILD_BUG_ON(sizeof(*(ptr)) != 4);				\
-	cmpxchg_relaxed((ptr), (o), (n))				\
+	arch_cmpxchg_relaxed((ptr), (o), (n))				\
 })
 
-#define cmpxchg64(ptr, o, n)						\
+#define arch_cmpxchg64(ptr, o, n)					\
 ({									\
 	BUILD_BUG_ON(sizeof(*(ptr)) != 8);				\
-	cmpxchg((ptr), (o), (n));					\
+	arch_cmpxchg((ptr), (o), (n));					\
 })
 
-#define cmpxchg64_local(ptr, o, n)					\
+#define arch_cmpxchg64_local(ptr, o, n)					\
 ({									\
 	BUILD_BUG_ON(sizeof(*(ptr)) != 8);				\
-	cmpxchg_relaxed((ptr), (o), (n));				\
+	arch_cmpxchg_relaxed((ptr), (o), (n));				\
 })
 
 #endif /* _ASM_RISCV_CMPXCHG_H */