A method for preventing deadlock due to the need for data exclusivity when performing forced atomic instructions in a multi-level cache in a multi-processor system. The system determines whether an aligned multi-byte word in which the data of a forced atomic instruction, such as an integer store operation, is exclusive in a first level cache. If so, the forced atomic instruction is allowed to enter a second level cache pipeline. If not, the forced atomic instruction is prevented from entering the second level cache pipeline and a cache miss and fill operation is initiated to cause the aligned word to be exclusive in the first level cache.