| | 8 | |
| | 9 | {{{ |
| | 10 | |
| | 11 | inline static int GC_test_and_set(volatile unsigned int *addr) { |
| | 12 | int oldval; |
| | 13 | int temp = 1; /* locked value */ |
| | 14 | |
| | 15 | __asm__ __volatile__( |
| | 16 | "1:\tlwarx %0,0,%3\n" /* load and reserve */ |
| | 17 | "\tcmpwi %0, 0\n" /* if load is */ |
| | 18 | "\tbne 2f\n" /* non-zero, return already set */ |
| | 19 | "\tstwcx. %2,0,%1\n" /* else store conditional */ |
| | 20 | "\tbne- 1b\n" /* retry if lost reservation */ |
| | 21 | "\tsync\n" /* import barrier */ |
| | 22 | "2:\t\n" /* oldval is zero if we set */ |
| | 23 | : "=&r"(oldval), "=p"(addr) |
| | 24 | : "r"(temp), "1"(addr) |
| | 25 | : "cr0","memory"); |
| | 26 | return oldval; |
| | 27 | } |
| | 28 | }}} |
