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40 /* PROLOG END TAG zYx */
41 #ifndef _SPU_ATOMIC_DEC_IF_POSITIVE_H_
42 #define _SPU_ATOMIC_DEC_IF_POSITIVE_H_
44 #include <sync_utils.h>
48 * atomic_dec_if_positive - atomically decrement if counter is positive.
49 * @v: handle to effective address of counter.
51 * Atomically decrement a counter if its value is positive.
52 * The only restriction is that @v must be word aligned.
55 * Returns the old value of the counter, minus 1.
57 static __inline int _atomic_dec_if_positive(atomic_ea_t v)
62 ea64.ull = ALIGN128_EA(v);
63 offset = OFFSET128_EA_U32(v);
65 MFC_DMA(buf, ea64, size, tagid, MFC_GETLLAR_CMD);
66 spu_readch(MFC_RdAtomicStat);
68 ret_val = buf[offset] - 1;
69 if (likely(ret_val >= 0)) {
70 buf[offset] = ret_val;
71 MFC_DMA(buf, ea64, size, tagid, MFC_PUTLLC_CMD);
72 status = spu_readch(MFC_RdAtomicStat);
74 MFC_DMA(buf, ea64, size, tagid, MFC_PUTLLC_CMD);
75 spu_readch(MFC_RdAtomicStat);
79 } while (status != 0);
86 #endif /* _SPU_ATOMIC_DEC_IF_POSITIVE_H_ */