locking/arch: Rename all internal __xchg() names to __arch_xchg()

Decrease the probability of this internal facility to be used by
driver code.

Signed-off-by: Andrzej Hajda <[e-mail]>
Signed-off-by: Peter Zijlstra (Intel) <[e-mail]>
Signed-off-by: Ingo Molnar <[e-mail]>
Reviewed-by: Arnd Bergmann <[e-mail]>
Reviewed-by: Andi Shyti <[e-mail]>
Acked-by: Geert Uytterhoeven <[e-mail]> [m68k]
Acked-by: Palmer Dabbelt <[e-mail]> [riscv]
Link: https://lore.kernel.org/r/[e-mail]
Cc: Linus Torvalds <[e-mail]>

arch/alpha/include/asm/cmpxchg.h

···
  * Atomic exchange routines.
  */
 
-#define ____xchg(type, args...)		__xchg ## type ## _local(args)
+#define ____xchg(type, args...)		__arch_xchg ## type ## _local(args)
 #define ____cmpxchg(type, args...)	__cmpxchg ## type ## _local(args)
 #include <asm/xchg.h>
 
 #define xchg_local(ptr, x)						\
 ({									\
 	__typeof__(*(ptr)) _x_ = (x);					\
-	(__typeof__(*(ptr))) __xchg_local((ptr), (unsigned long)_x_,	\
-				       sizeof(*(ptr)));			\
+	(__typeof__(*(ptr))) __arch_xchg_local((ptr), (unsigned long)_x_,\
+					       sizeof(*(ptr)));		\
 })
 
 #define arch_cmpxchg_local(ptr, o, n)					\
···
 
 #undef ____xchg
 #undef ____cmpxchg
-#define ____xchg(type, args...)		__xchg ##type(args)
+#define ____xchg(type, args...)		__arch_xchg ##type(args)
 #define ____cmpxchg(type, args...)	__cmpxchg ##type(args)
 #include <asm/xchg.h>
 
···
 	__typeof__(*(ptr)) _x_ = (x);					\
 	smp_mb();							\
 	__ret = (__typeof__(*(ptr)))					\
-		__xchg((ptr), (unsigned long)_x_, sizeof(*(ptr)));	\
+		__arch_xchg((ptr), (unsigned long)_x_, sizeof(*(ptr)));	\
 	smp_mb();							\
 	__ret;								\
 })

arch/arc/include/asm/cmpxchg.h

···
  */
 #ifdef CONFIG_ARC_HAS_LLSC
 
-#define __xchg(ptr, val)						\
+#define __arch_xchg(ptr, val)						\
 ({									\
 	__asm__ __volatile__(						\
 	"	ex  %0, [%1]	\n"	/* set new value */	        \
···
 									\
 	switch(sizeof(*(_p_))) {					\
 	case 4:								\
-		_val_ = __xchg(_p_, _val_);				\
+		_val_ = __arch_xchg(_p_, _val_);			\
 		break;							\
 	default:							\
 		BUILD_BUG();						\

arch/arm/include/asm/cmpxchg.h

···
 #define swp_is_buggy
 #endif
 
-static inline unsigned long __xchg(unsigned long x, volatile void *ptr, int size)
+static inline unsigned long
+__arch_xchg(unsigned long x, volatile void *ptr, int size)
 {
 	extern void __bad_xchg(volatile void *, int);
 	unsigned long ret;
···
 }
 
 #define arch_xchg_relaxed(ptr, x) ({					\
-	(__typeof__(*(ptr)))__xchg((unsigned long)(x), (ptr),		\
-				   sizeof(*(ptr)));			\
+	(__typeof__(*(ptr)))__arch_xchg((unsigned long)(x), (ptr),	\
+					sizeof(*(ptr)));		\
 })
 
 #include <asm-generic/cmpxchg-local.h>

arch/arm64/include/asm/cmpxchg.h

···
 #undef __XCHG_CASE
 
 #define __XCHG_GEN(sfx)							\
-static __always_inline  unsigned long __xchg##sfx(unsigned long x,	\
-					volatile void *ptr,		\
-					int size)			\
+static __always_inline unsigned long					\
+__arch_xchg##sfx(unsigned long x, volatile void *ptr, int size)		\
 {									\
 	switch (size) {							\
 	case 1:								\
···
 ({									\
 	__typeof__(*(ptr)) __ret;					\
 	__ret = (__typeof__(*(ptr)))					\
-		__xchg##sfx((unsigned long)(x), (ptr), sizeof(*(ptr))); \
+		__arch_xchg##sfx((unsigned long)(x), (ptr), sizeof(*(ptr))); \
 	__ret;								\
 })
 

arch/hexagon/include/asm/cmpxchg.h

···
 #define _ASM_CMPXCHG_H
 
 /*
- * __xchg - atomically exchange a register and a memory location
+ * __arch_xchg - atomically exchange a register and a memory location
  * @x: value to swap
  * @ptr: pointer to memory
  * @size:  size of the value
···
  * Note:  there was an errata for V2 about .new's and memw_locked.
  *
  */
-static inline unsigned long __xchg(unsigned long x, volatile void *ptr,
-				   int size)
+static inline unsigned long
+__arch_xchg(unsigned long x, volatile void *ptr, int size)
 {
 	unsigned long retval;
 
···
  * Atomically swap the contents of a register with memory.  Should be atomic
  * between multiple CPU's and within interrupts on the same CPU.
  */
-#define arch_xchg(ptr, v) ((__typeof__(*(ptr)))__xchg((unsigned long)(v), (ptr), \
-	sizeof(*(ptr))))
+#define arch_xchg(ptr, v) ((__typeof__(*(ptr)))__arch_xchg((unsigned long)(v), (ptr), \
+							   sizeof(*(ptr))))
 
 /*
  *  see rt-mutex-design.txt; cmpxchg supposedly checks if *ptr == A and swaps.

arch/ia64/include/asm/cmpxchg.h

···
 #include <uapi/asm/cmpxchg.h>
 
 #define arch_xchg(ptr, x)	\
-({(__typeof__(*(ptr))) __xchg((unsigned long) (x), (ptr), sizeof(*(ptr)));})
+({(__typeof__(*(ptr))) __arch_xchg((unsigned long) (x), (ptr), sizeof(*(ptr)));})
 
 #define arch_cmpxchg(ptr, o, n)		cmpxchg_acq((ptr), (o), (n))
 #define arch_cmpxchg64(ptr, o, n)	cmpxchg_acq((ptr), (o), (n))

arch/ia64/include/uapi/asm/cmpxchg.h

···
  */
 extern void ia64_xchg_called_with_bad_pointer(void);
 
-#define __xchg(x, ptr, size)						\
+#define __arch_xchg(x, ptr, size)					\
 ({									\
 	unsigned long __xchg_result;					\
 									\
···
 
 #ifndef __KERNEL__
 #define xchg(ptr, x)							\
-({(__typeof__(*(ptr))) __xchg((unsigned long) (x), (ptr), sizeof(*(ptr)));})
+({(__typeof__(*(ptr))) __arch_xchg((unsigned long) (x), (ptr), sizeof(*(ptr)));})
 #endif
 
 /*

arch/loongarch/include/asm/cmpxchg.h

···
 }
 
 static __always_inline unsigned long
-__xchg(volatile void *ptr, unsigned long x, int size)
+__arch_xchg(volatile void *ptr, unsigned long x, int size)
 {
 	switch (size) {
 	case 1:
···
 	__typeof__(*(ptr)) __res;					\
 									\
 	__res = (__typeof__(*(ptr)))					\
-		__xchg((ptr), (unsigned long)(x), sizeof(*(ptr)));	\
+		__arch_xchg((ptr), (unsigned long)(x), sizeof(*(ptr)));	\
 									\
 	__res;								\
 })

arch/m68k/include/asm/cmpxchg.h

···
 extern unsigned long __invalid_xchg_size(unsigned long, volatile void *, int);
 
 #ifndef CONFIG_RMW_INSNS
-static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
+static inline unsigned long __arch_xchg(unsigned long x, volatile void * ptr, int size)
 {
 	unsigned long flags, tmp;
 
···
 	return x;
 }
 #else
-static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
+static inline unsigned long __arch_xchg(unsigned long x, volatile void * ptr, int size)
 {
 	switch (size) {
 	case 1:
···
 }
 #endif
 
-#define arch_xchg(ptr,x) ({(__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr)));})
+#define arch_xchg(ptr,x) ({(__typeof__(*(ptr)))__arch_xchg((unsigned long)(x),(ptr),sizeof(*(ptr)));})
 
 #include <asm-generic/cmpxchg-local.h>
 

arch/mips/include/asm/cmpxchg.h

···
 				  unsigned int size);
 
 static __always_inline
-unsigned long __xchg(volatile void *ptr, unsigned long x, int size)
+unsigned long __arch_xchg(volatile void *ptr, unsigned long x, int size)
 {
 	switch (size) {
 	case 1:
···
 		smp_mb__before_llsc();					\
 									\
 	__res = (__typeof__(*(ptr)))					\
-		__xchg((ptr), (unsigned long)(x), sizeof(*(ptr)));	\
+		__arch_xchg((ptr), (unsigned long)(x), sizeof(*(ptr)));	\
 									\
 	smp_llsc_mb();							\
 									\

arch/openrisc/include/asm/cmpxchg.h

···
 extern unsigned long __xchg_called_with_bad_pointer(void)
 	__compiletime_error("Bad argument size for xchg");
 
-static inline unsigned long __xchg(volatile void *ptr, unsigned long with,
-		int size)
+static inline unsigned long
+__arch_xchg(volatile void *ptr, unsigned long with, int size)
 {
 	switch (size) {
 	case 1:
···
 
 #define arch_xchg(ptr, with) 						\
 	({								\
-		(__typeof__(*(ptr))) __xchg((ptr),			\
-					    (unsigned long)(with),	\
-					    sizeof(*(ptr)));		\
+		(__typeof__(*(ptr))) __arch_xchg((ptr),			\
+						 (unsigned long)(with),	\
+						 sizeof(*(ptr)));	\
 	})
 
 #endif /* __ASM_OPENRISC_CMPXCHG_H */

arch/parisc/include/asm/cmpxchg.h

···
 
 /* optimizer better get rid of switch since size is a constant */
 static inline unsigned long
-__xchg(unsigned long x, volatile void *ptr, int size)
+__arch_xchg(unsigned long x, volatile void *ptr, int size)
 {
 	switch (size) {
 #ifdef CONFIG_64BIT
···
 	__typeof__(*(ptr)) __ret;					\
 	__typeof__(*(ptr)) _x_ = (x);					\
 	__ret = (__typeof__(*(ptr)))					\
-		__xchg((unsigned long)_x_, (ptr), sizeof(*(ptr)));	\
+		__arch_xchg((unsigned long)_x_, (ptr), sizeof(*(ptr)));	\
 	__ret;								\
 })
 

arch/powerpc/include/asm/cmpxchg.h

···
 		return __xchg_u64_local(ptr, x);
 #endif
 	}
-	BUILD_BUG_ON_MSG(1, "Unsupported size for __xchg");
+	BUILD_BUG_ON_MSG(1, "Unsupported size for __xchg_local");
 	return x;
 }
 
···
 		return __xchg_u64_relaxed(ptr, x);
 #endif
 	}
-	BUILD_BUG_ON_MSG(1, "Unsupported size for __xchg_local");
+	BUILD_BUG_ON_MSG(1, "Unsupported size for __xchg_relaxed");
 	return x;
 }
 #define arch_xchg_local(ptr,x)						     \

arch/riscv/include/asm/atomic.h

···
 static __always_inline							\
 c_t arch_atomic##prefix##_xchg(atomic##prefix##_t *v, c_t n)		\
 {									\
-	return __xchg(&(v->counter), n, size);				\
+	return __arch_xchg(&(v->counter), n, size);			\
 }									\
 static __always_inline							\
 c_t arch_atomic##prefix##_cmpxchg_relaxed(atomic##prefix##_t *v,	\

arch/riscv/include/asm/cmpxchg.h

···
 					    _x_, sizeof(*(ptr)));	\
 })
 
-#define __xchg(ptr, new, size)						\
+#define __arch_xchg(ptr, new, size)					\
 ({									\
 	__typeof__(ptr) __ptr = (ptr);					\
 	__typeof__(new) __new = (new);					\
···
 #define arch_xchg(ptr, x)						\
 ({									\
 	__typeof__(*(ptr)) _x_ = (x);					\
-	(__typeof__(*(ptr))) __xchg((ptr), _x_, sizeof(*(ptr)));	\
+	(__typeof__(*(ptr))) __arch_xchg((ptr), _x_, sizeof(*(ptr)));	\
 })
 
 #define xchg32(ptr, x)							\

arch/s390/include/asm/cmpxchg.h

···
 
 void __xchg_called_with_bad_pointer(void);
 
-static __always_inline unsigned long __xchg(unsigned long x,
-					    unsigned long address, int size)
+static __always_inline unsigned long
+__arch_xchg(unsigned long x, unsigned long address, int size)
 {
 	unsigned long old;
 	int shift;
···
 	__typeof__(*(ptr)) __ret;					\
 									\
 	__ret = (__typeof__(*(ptr)))					\
-		__xchg((unsigned long)(x), (unsigned long)(ptr),	\
-		       sizeof(*(ptr)));					\
+		__arch_xchg((unsigned long)(x), (unsigned long)(ptr),	\
+			    sizeof(*(ptr)));				\
 	__ret;								\
 })
 

arch/sh/include/asm/cmpxchg.h

···
 
 extern void __xchg_called_with_bad_pointer(void);
 
-#define __xchg(ptr, x, size)				\
+#define __arch_xchg(ptr, x, size)				\
 ({							\
 	unsigned long __xchg__res;			\
 	volatile void *__xchg_ptr = (ptr);		\
···
 })
 
 #define arch_xchg(ptr,x)	\
-	((__typeof__(*(ptr)))__xchg((ptr),(unsigned long)(x), sizeof(*(ptr))))
+	((__typeof__(*(ptr)))__arch_xchg((ptr),(unsigned long)(x), sizeof(*(ptr))))
 
 /* This function doesn't exist, so you'll get a linker error
  * if something tries to do an invalid cmpxchg(). */

arch/sparc/include/asm/cmpxchg_32.h

···
 unsigned long __xchg_u32(volatile u32 *m, u32 new);
 void __xchg_called_with_bad_pointer(void);
 
-static inline unsigned long __xchg(unsigned long x, __volatile__ void * ptr, int size)
+static inline unsigned long __arch_xchg(unsigned long x, __volatile__ void * ptr, int size)
 {
 	switch (size) {
 	case 4:
···
 	return x;
 }
 
-#define arch_xchg(ptr,x) ({(__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr)));})
+#define arch_xchg(ptr,x) ({(__typeof__(*(ptr)))__arch_xchg((unsigned long)(x),(ptr),sizeof(*(ptr)));})
 
 /* Emulate cmpxchg() the same way we emulate atomics,
  * by hashing the object address and indexing into an array

arch/sparc/include/asm/cmpxchg_64.h

···
 #define arch_xchg(ptr,x)							\
 ({	__typeof__(*(ptr)) __ret;					\
 	__ret = (__typeof__(*(ptr)))					\
-		__xchg((unsigned long)(x), (ptr), sizeof(*(ptr)));	\
+		__arch_xchg((unsigned long)(x), (ptr), sizeof(*(ptr)));	\
 	__ret;								\
 })
 
···
 	return (load32 & mask) >> bit_shift;
 }
 
-static inline unsigned long __xchg(unsigned long x, __volatile__ void * ptr,
-				       int size)
+static inline unsigned long
+__arch_xchg(unsigned long x, __volatile__ void * ptr, int size)
 {
 	switch (size) {
 	case 2:

arch/xtensa/include/asm/cmpxchg.h

···
 }
 
 #define arch_xchg(ptr,x) \
-	((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
+	((__typeof__(*(ptr)))__arch_xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
 
 static inline u32 xchg_small(volatile void *ptr, u32 x, int size)
 {
···
 extern void __xchg_called_with_bad_pointer(void);
 
 static __inline__ unsigned long
-__xchg(unsigned long x, volatile void * ptr, int size)
+__arch_xchg(unsigned long x, volatile void * ptr, int size)
 {
 	switch (size) {
 	case 1: