riscv: remove unused __cmpxchg_user() macro

This macro is defined but not used, remove it.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

arch/riscv/include/asm/uaccess.h

@@ -388,81 +388,6 @@ unsigned long __must_check clear_user(void __user *to, unsigned long n)
 		__clear_user(to, n) : n;
 }
 
-/*
- * Atomic compare-and-exchange, but with a fixup for userspace faults.  Faults
- * will set "err" to -EFAULT, while successful accesses return the previous
- * value.
- */
-#define __cmpxchg_user(ptr, old, new, err, size, lrb, scb)	\
-({								\
-	__typeof__(ptr) __ptr = (ptr);				\
-	__typeof__(*(ptr)) __old = (old);			\
-	__typeof__(*(ptr)) __new = (new);			\
-	__typeof__(*(ptr)) __ret;				\
-	__typeof__(err) __err = 0;				\
-	register unsigned int __rc;				\
-	__enable_user_access();					\
-	switch (size) {						\
-	case 4:							\
-		__asm__ __volatile__ (				\
-		"0:\n"						\
-		"	lr.w" #scb " %[ret], %[ptr]\n"		\
-		"	bne          %[ret], %z[old], 1f\n"	\
-		"	sc.w" #lrb " %[rc], %z[new], %[ptr]\n"	\
-		"	bnez         %[rc], 0b\n"		\
-		"1:\n"						\
-		".section .fixup,\"ax\"\n"			\
-		".balign 4\n"					\
-		"2:\n"						\
-		"	li %[err], %[efault]\n"			\
-		"	jump 1b, %[rc]\n"			\
-		".previous\n"					\
-		".section __ex_table,\"a\"\n"			\
-		".balign " RISCV_SZPTR "\n"			\
-		"	" RISCV_PTR " 1b, 2b\n"			\
-		".previous\n"					\
-			: [ret] "=&r" (__ret),			\
-			  [rc]  "=&r" (__rc),			\
-			  [ptr] "+A" (*__ptr),			\
-			  [err] "=&r" (__err)			\
-			: [old] "rJ" (__old),			\
-			  [new] "rJ" (__new),			\
-			  [efault] "i" (-EFAULT));		\
-		break;						\
-	case 8:							\
-		__asm__ __volatile__ (				\
-		"0:\n"						\
-		"	lr.d" #scb " %[ret], %[ptr]\n"		\
-		"	bne          %[ret], %z[old], 1f\n"	\
-		"	sc.d" #lrb " %[rc], %z[new], %[ptr]\n"	\
-		"	bnez         %[rc], 0b\n"		\
-		"1:\n"						\
-		".section .fixup,\"ax\"\n"			\
-		".balign 4\n"					\
-		"2:\n"						\
-		"	li %[err], %[efault]\n"			\
-		"	jump 1b, %[rc]\n"			\
-		".previous\n"					\
-		".section __ex_table,\"a\"\n"			\
-		".balign " RISCV_SZPTR "\n"			\
-		"	" RISCV_PTR " 1b, 2b\n"			\
-		".previous\n"					\
-			: [ret] "=&r" (__ret),			\
-			  [rc]  "=&r" (__rc),			\
-			  [ptr] "+A" (*__ptr),			\
-			  [err] "=&r" (__err)			\
-			: [old] "rJ" (__old),			\
-			  [new] "rJ" (__new),			\
-			  [efault] "i" (-EFAULT));		\
-		break;						\
-	default:						\
-		BUILD_BUG();					\
-	}							\
-	__disable_user_access();				\
-	(err) = __err;						\
-	__ret;							\
-})
-
 #define HAVE_GET_KERNEL_NOFAULT
 
 #define __get_kernel_nofault(dst, src, type, err_label)			\