Processing cache evictions in a directory snoop filter with ECAM

A computer system for sharing data comprising:

• a memory which stores instructions;
• one or more processors coupled to the memory wherein the one or more processors, when executing the instructions which are stored, are configured to:
• access a system-on-a-chip (SOC), wherein the SOC includes one or more compute coherency blocks (CCBs) and one or more coherency ordering agents (COAs), wherein a first COA within the one or more COAs comprises a directory snoop filter (DSF), an eviction content addressable memory (eCAM), a miss and snoop queue (MSQ), and a pipeline logic, wherein the DSF comprises N ways;
• initiate, by a first CCB in the one or more CCBs, a read request to a first address, wherein the first address includes a first index, wherein the read request misses in the DSF, and wherein the DSF is occupied with a valid data at each way of the N ways corresponding to the first index;
• select, by the DSF, a cache line for eviction, wherein the cache line includes the first index and a selected way within the N ways, wherein the first index and the selected way are stored in an entry within one or more entries of the eCAM;
• save the read request from the first CCB in the MSQ;
• arbitrate, by the eCAM, for the pipeline logic within the COA, wherein the arbitrating includes selecting, by the eCAM, the entry to send to the pipeline logic;
• send, by the eCAM, to the pipeline logic, the entry, wherein the sending causes a cache line associated with the first index to be evicted from the DSF, wherein the cache line is associated with a second address, wherein the sending includes writing, to the eCAM, by the DSF, the second address, wherein the second address overwrites the entry in the eCAM, and wherein the sending includes generating, by the pipeline logic, a snoop of the second address;
• mediate, by the MSQ, for the pipeline logic within the COA, wherein the mediating includes replaying, to the pipeline logic, by the MSQ, the read request to the first address;
• and
• start, by the COA, the read request to the first address, wherein the read request to the first address is handled coherently.