locking/atomic: hexagon: 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 hexagon 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: NMark Rutland <mark.rutland@arm.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210525140232.53872-19-mark.rutland@arm.com

arch/hexagon/Kconfig

@@ -5,6 +5,7 @@ comment "Linux Kernel Configuration for Hexagon"
 config HEXAGON
 	def_bool y
 	select ARCH_32BIT_OFF_T
+	select ARCH_ATOMIC
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
 	select ARCH_NO_PREEMPT
 	# Other pending projects/to-do items.

arch/hexagon/include/asm/atomic.h

@@ -14,7 +14,7 @@
 
 /*  Normal writes in our arch don't clear lock reservations  */
 
-static inline void atomic_set(atomic_t *v, int new)
+static inline void arch_atomic_set(atomic_t *v, int new)
 {
 	asm volatile(
 		"1:	r6 = memw_locked(%0);\n"
@@ -26,26 +26,26 @@ static inline void atomic_set(atomic_t *v, int new)
 	);
 }
 
-#define atomic_set_release(v, i)	atomic_set((v), (i))
+#define arch_atomic_set_release(v, i)	arch_atomic_set((v), (i))
 
 /**
- * atomic_read - reads a word, atomically
+ * arch_atomic_read - reads a word, atomically
  * @v: pointer to atomic value
  *
  * Assumes all word reads on our architecture are atomic.
  */
-#define atomic_read(v)		READ_ONCE((v)->counter)
+#define arch_atomic_read(v)		READ_ONCE((v)->counter)
 
 /**
- * atomic_xchg - atomic
+ * arch_atomic_xchg - atomic
  * @v: pointer to memory to change
  * @new: new value (technically passed in a register -- see xchg)
  */
-#define atomic_xchg(v, new)	(xchg(&((v)->counter), (new)))
+#define arch_atomic_xchg(v, new)	(arch_xchg(&((v)->counter), (new)))
 
 
 /**
- * atomic_cmpxchg - atomic compare-and-exchange values
+ * arch_atomic_cmpxchg - atomic compare-and-exchange values
  * @v: pointer to value to change
  * @old:  desired old value to match
  * @new:  new value to put in
@@ -61,7 +61,7 @@ static inline void atomic_set(atomic_t *v, int new)
  *
  * "old" is "expected" old val, __oldval is actual old value
  */
-static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
+static inline int arch_atomic_cmpxchg(atomic_t *v, int old, int new)
 {
 	int __oldval;
 
@@ -81,7 +81,7 @@ static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
 }
 
 #define ATOMIC_OP(op)							\
-static inline void atomic_##op(int i, atomic_t *v)			\
+static inline void arch_atomic_##op(int i, atomic_t *v)			\
 {									\
 	int output;							\
 									\
@@ -97,7 +97,7 @@ static inline void atomic_##op(int i, atomic_t *v)			\
 }									\
 
 #define ATOMIC_OP_RETURN(op)						\
-static inline int atomic_##op##_return(int i, atomic_t *v)		\
+static inline int arch_atomic_##op##_return(int i, atomic_t *v)		\
 {									\
 	int output;							\
 									\
@@ -114,7 +114,7 @@ static inline int atomic_##op##_return(int i, atomic_t *v)		\
 }
 
 #define ATOMIC_FETCH_OP(op)						\
-static inline int atomic_fetch_##op(int i, atomic_t *v)			\
+static inline int arch_atomic_fetch_##op(int i, atomic_t *v)		\
 {									\
 	int output, val;						\
 									\
@@ -148,7 +148,7 @@ ATOMIC_OPS(xor)
 #undef ATOMIC_OP
 
 /**
- * atomic_fetch_add_unless - add unless the number is a given value
+ * arch_atomic_fetch_add_unless - add unless the number is a given value
  * @v: pointer to value
  * @a: amount to add
  * @u: unless value is equal to u
@@ -157,7 +157,7 @@ ATOMIC_OPS(xor)
  *
  */
 
-static inline int atomic_fetch_add_unless(atomic_t *v, int a, int u)
+static inline int arch_atomic_fetch_add_unless(atomic_t *v, int a, int u)
 {
 	int __oldval;
 	register int tmp;
@@ -180,6 +180,6 @@ static inline int atomic_fetch_add_unless(atomic_t *v, int a, int u)
 	);
 	return __oldval;
 }
-#define atomic_fetch_add_unless atomic_fetch_add_unless
+#define arch_atomic_fetch_add_unless arch_atomic_fetch_add_unless
 
 #endif

arch/hexagon/include/asm/cmpxchg.h

@@ -42,7 +42,7 @@ static inline unsigned long __xchg(unsigned long x, volatile void *ptr,
  * Atomically swap the contents of a register with memory.  Should be atomic
  * between multiple CPU's and within interrupts on the same CPU.
  */
-#define xchg(ptr, v) ((__typeof__(*(ptr)))__xchg((unsigned long)(v), (ptr), \
+#define arch_xchg(ptr, v) ((__typeof__(*(ptr)))__xchg((unsigned long)(v), (ptr), \
 	sizeof(*(ptr))))
 
 /*
@@ -51,7 +51,7 @@ static inline unsigned long __xchg(unsigned long x, volatile void *ptr,
  *  variable casting.
  */
 
-#define cmpxchg(ptr, old, new)					\
+#define arch_cmpxchg(ptr, old, new)				\
 ({								\
 	__typeof__(ptr) __ptr = (ptr);				\
 	__typeof__(*(ptr)) __old = (old);			\