3  * resource counting etc..
21 #include <asm/cpu-features.h>
30 	return READ_ONCE(v->counter);					\
35 	WRITE_ONCE(v->counter, i);					\
40 	return cmpxchg(&v->counter, o, n);				\
45 	return xchg(&v->counter, n);					\
55 #define ATOMIC_OP(pfx, op, type, c_op, asm_op, ll, sc)			\  argument
64 		v->counter c_op i;					\
75 	"	" #sc "	%0, %1					\n"	\
78 	: "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (v->counter)		\
82 #define ATOMIC_OP_RETURN(pfx, op, type, c_op, asm_op, ll, sc)		\  argument
91 		result = v->counter;					\
93 		v->counter = result;					\
104 	"	" #sc "	%0, %2					\n"	\
109 	  "+" GCC_OFF_SMALL_ASM() (v->counter)				\
115 #define ATOMIC_FETCH_OP(pfx, op, type, c_op, asm_op, ll, sc)		\  argument
124 		result = v->counter;					\
125 		v->counter c_op i;					\
136 	"	" #sc "	%0, %2					\n"	\
141 	  "+" GCC_OFF_SMALL_ASM() (v->counter)				\
148 #define ATOMIC_OPS(pfx, op, type, c_op, asm_op, ll, sc)			\  argument
149 	ATOMIC_OP(pfx, op, type, c_op, asm_op, ll, sc)			\
150 	ATOMIC_OP_RETURN(pfx, op, type, c_op, asm_op, ll, sc)		\
151 	ATOMIC_FETCH_OP(pfx, op, type, c_op, asm_op, ll, sc)
153 ATOMIC_OPS(atomic, add, int, +=, addu, ll, sc)
154 ATOMIC_OPS(atomic, sub, int, -=, subu, ll, sc)
163 ATOMIC_OPS(atomic64, sub, s64, -=, dsubu, lld, scd)
171 #define ATOMIC_OPS(pfx, op, type, c_op, asm_op, ll, sc)			\  argument
172 	ATOMIC_OP(pfx, op, type, c_op, asm_op, ll, sc)			\
173 	ATOMIC_FETCH_OP(pfx, op, type, c_op, asm_op, ll, sc)
175 ATOMIC_OPS(atomic, and, int, &=, and, ll, sc)
176 ATOMIC_OPS(atomic, or, int, |=, or, ll, sc)
177 ATOMIC_OPS(atomic, xor, int, ^=, xor, ll, sc)
198  * atomic_sub_if_positive - conditionally subtract integer from atomic variable
205 #define ATOMIC_SIP_OP(pfx, type, op, ll, sc)				\  argument
216 		result = v->counter;					\
217 		result -= i;						\
219 			v->counter = result;				\
236 	"	" #sc "	%1, %2					\n"	\
241 	  "+" GCC_OFF_SMALL_ASM() (v->counter)				\
248 	 * bltz that can branch	to code outside of the LL/SC loop. As	\
257 ATOMIC_SIP_OP(atomic, int, subu, ll, sc)