A circuit arrangement and method utilize cache injection logic to perform a cache inject and lock operation to inject a cache line in a cache memory and automatically lock the cache line in the cache memory in parallel with communication of the cache line to a main memory. The cache injection logic may additionally limit the maximum number of locked cache lines that may be stored in the cache memory, e.g., by aborting a cache inject and lock operation, injecting the cache line without locking, or unlocking and/or evicting another cache line in the cache memory.