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| Rev 1864 | Rev 1888 | ||
|---|---|---|---|
| Line 47... | Line 47... | ||
| 47 | * @return Value of the atomic variable as it existed before addition. |
47 | * @return Value of the atomic variable as it existed before addition. |
| 48 | */ |
48 | */ |
| 49 | static inline long atomic_add(atomic_t *val, int i) |
49 | static inline long atomic_add(atomic_t *val, int i) |
| 50 | { |
50 | { |
| 51 | uint64_t a, b; |
51 | uint64_t a, b; |
| 52 | volatile uint64_t x = (uint64_t) &val->count; |
- | |
| 53 | 52 | ||
| 54 | __asm__ volatile ( |
- | |
| 55 | "0:\n" |
53 | do { |
| 56 | "ldx %0, %1\n" |
- | |
| 57 | "add %1, %3, %2\n" |
54 | volatile uintptr_t x = (uint64_t) &val->count; |
| - | 55 | ||
| 58 | "casx %0, %1, %2\n" |
56 | a = *((uint64_t *) x); |
| 59 | "cmp %1, %2\n" |
57 | b = a + i; |
| 60 | "bne 0b\n" /* The operation failed and must be attempted again if a != b. */ |
- | |
| 61 | "nop\n" |
- | |
| 62 | : "=m" (*((uint64_t *)x)), "=r" (a), "=r" (b) |
58 | __asm__ volatile ("casx %0, %1, %2\n": "+m" (*((uint64_t *)x)), "+r" (a), "+r" (b)); |
| 63 | : "r" (i) |
59 | } while (a != b); |
| 64 | ); |
- | |
| 65 | 60 | ||
| 66 | return a; |
61 | return a; |
| 67 | } |
62 | } |
| 68 | 63 | ||
| 69 | static inline long atomic_preinc(atomic_t *val) |
64 | static inline long atomic_preinc(atomic_t *val) |