-#define xchg(ptr,x) \
-({ \
- __typeof__(*(ptr)) __ret; \
- __ret = (__typeof__(*(ptr))) \
- __xchg((unsigned long)(x), (ptr), sizeof(*(ptr))); \
- __ret; \
-})
-
-static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
- unsigned long new, int size)
-{
- unsigned long oldval = 0, res;
-
- switch (size) {
- case 1:
- do {
- asm volatile("// __cmpxchg1\n"
- " ldxrb %w1, %2\n"
- " mov %w0, #0\n"
- " cmp %w1, %w3\n"
- " b.ne 1f\n"
- " stxrb %w0, %w4, %2\n"
- "1:\n"
- : "=&r" (res), "=&r" (oldval), "+Q" (*(u8 *)ptr)
- : "Ir" (old), "r" (new)
- : "cc");
- } while (res);
- break;
-
- case 2:
- do {
- asm volatile("// __cmpxchg2\n"
- " ldxrh %w1, %2\n"
- " mov %w0, #0\n"
- " cmp %w1, %w3\n"
- " b.ne 1f\n"
- " stxrh %w0, %w4, %2\n"
- "1:\n"
- : "=&r" (res), "=&r" (oldval), "+Q" (*(u16 *)ptr)
- : "Ir" (old), "r" (new)
- : "cc");
- } while (res);
- break;
-
- case 4:
- do {
- asm volatile("// __cmpxchg4\n"
- " ldxr %w1, %2\n"
- " mov %w0, #0\n"
- " cmp %w1, %w3\n"
- " b.ne 1f\n"
- " stxr %w0, %w4, %2\n"
- "1:\n"
- : "=&r" (res), "=&r" (oldval), "+Q" (*(u32 *)ptr)
- : "Ir" (old), "r" (new)
- : "cc");
- } while (res);
- break;
-
- case 8:
- do {
- asm volatile("// __cmpxchg8\n"
- " ldxr %1, %2\n"
- " mov %w0, #0\n"
- " cmp %1, %3\n"
- " b.ne 1f\n"
- " stxr %w0, %4, %2\n"
- "1:\n"
- : "=&r" (res), "=&r" (oldval), "+Q" (*(u64 *)ptr)
- : "Ir" (old), "r" (new)
- : "cc");
- } while (res);
- break;
-
- default:
- BUILD_BUG();
- }
-
- return oldval;
+__XCHG_CASE(w, b, 1, , , , , , )
+__XCHG_CASE(w, h, 2, , , , , , )
+__XCHG_CASE(w, , 4, , , , , , )
+__XCHG_CASE( , , 8, , , , , , )
+__XCHG_CASE(w, b, acq_1, , , a, a, , "memory")
+__XCHG_CASE(w, h, acq_2, , , a, a, , "memory")
+__XCHG_CASE(w, , acq_4, , , a, a, , "memory")
+__XCHG_CASE( , , acq_8, , , a, a, , "memory")
+__XCHG_CASE(w, b, rel_1, , , , , l, "memory")
+__XCHG_CASE(w, h, rel_2, , , , , l, "memory")
+__XCHG_CASE(w, , rel_4, , , , , l, "memory")
+__XCHG_CASE( , , rel_8, , , , , l, "memory")
+__XCHG_CASE(w, b, mb_1, dmb ish, nop, , a, l, "memory")
+__XCHG_CASE(w, h, mb_2, dmb ish, nop, , a, l, "memory")
+__XCHG_CASE(w, , mb_4, dmb ish, nop, , a, l, "memory")
+__XCHG_CASE( , , mb_8, dmb ish, nop, , a, l, "memory")
+
+#undef __XCHG_CASE
+
+#define __XCHG_GEN(sfx) \
+static inline unsigned long __xchg##sfx(unsigned long x, \
+ volatile void *ptr, \
+ int size) \
+{ \
+ switch (size) { \
+ case 1: \
+ return __xchg_case##sfx##_1(x, ptr); \
+ case 2: \
+ return __xchg_case##sfx##_2(x, ptr); \
+ case 4: \
+ return __xchg_case##sfx##_4(x, ptr); \
+ case 8: \
+ return __xchg_case##sfx##_8(x, ptr); \
+ default: \
+ BUILD_BUG(); \
+ } \
+ \
+ unreachable(); \