Dynamic Integrity and Data Encryption (IDE) Aggregation Size
To reduce bandwidth overheads associated with a message authentication code (MAC), aggregation is useful. To ensure there is no latency impact, something more than aggregation is needed. Integrity and Data Encryption (IDE) securing transaction layer packets (TLPs) can be used in a dynamic manner whereby before aggregating a new packet to the IDE TLP, a determination is made regarding whether the packet contains user data so that the packets with user data can be sent immediately rather than wanting for more packets to aggregate. On the receiving side, execution of the packet can occur before completing an integrity check that occurs in IDE TLP transfers to reduce latency.
1 . A data storage device, comprising:
a memory device; and
a controller coupled to the memory device, wherein the controller is configured to:
create an integrity and data encryption (IDE) transaction layer packet (TLP) using a first TLP and a second TLP, wherein the IDE TLP includes an IDE TLP message authentication code (MAC);
prepare a third TLP;
determine whether to aggregate the third TLP with the first TLP and the second TLP; and
send the IDE TLP MAC to a host device with a last TLP.
2 . The data storage device of claim 1 , wherein the determining comprises determining whether the second TLP is a user data packet.
3 . The data storage device of claim 1 , wherein upon determining that the second TLP is a non-user data packet, the controller is configured to send the second TLP to the host device.
4 . The data storage device of claim 3 , wherein the IDE TLP MAC is a signature for protecting the IDE TLP and wherein the signature is for the first TLP, the second TLP, and the third TLP.
5 . The data storage device of claim 1 , wherein the controller is configured to aggregate the third TLP with the first TLP and second TLP upon determining that the third TLP is a user data packet TLP.
6 . The data storage device of claim 1 , wherein the controller is configured to aggregate up to eight TLPs into the IDE TLP.
7 . The data storage device of claim 6 , wherein the IDE TLP comprises at least two integrity protected portions, at least two sequence numbers, and the IDE TLP MAC.
8 . The data storage device of claim 7 , wherein a first integrity protected portion of the at least two integrity protected portions is for the first TLP, a second integrity protected portion of the at least two integrity protected portions is for the second TLP, a first sequence number of the at least two sequence numbers is for the first TLP, a second sequence number of the at least two sequence numbers if for the second TLP, and the IDE TLP MAC is for both the first TLP and the second TLP.
9 . The data storage device of claim 1 , wherein the controller comprises a host interface module (HIM) that includes an IDE TLP dynamic aggregation module.
10 . The data storage device of claim 1 , wherein the controller comprises a host interface module (HIM) that includes an IDE aggregation speculation execution module.
11 . The data storage device of claim 1 , wherein the controller is configured to start speculative usage of another IDE TLP before completing a protection check.
12 . A data storage device, comprising:
a memory device; and
a controller coupled to the memory device, wherein the controller is configured to:
receive a first chunk of an integrity and data encryption (IDE) transaction layer packet (TLP);
determine whether the first chunk is the last chunk of the IDE TLP;
determine if the first chunk is a non-user data packet; and
perform speculative usage of the IDE TLP before completing a protection check.
13 . The data storage device of claim 12 , wherein the controller is configured to wait for a second chunk upon determining that the first chunk is a non-data packet.
14 . The data storage device of claim 12 , wherein the controller is configured to perform the speculative usage upon determining that the first chunk is not a non-data packet.
15 . The data storage device of claim 12 , wherein the controller is configured to perform the protection check upon determining that the first chunk is the last chunk.
16 . The data storage device of claim 12 , wherein the controller is configured to wait for a second chunk while performing the speculative usage.
17 . The data storage device of claim 12 , wherein the controller is configured to encrypt the chunk and ignore the encrypted chunk if the chunk is determined to be a bad packet.
18 . A data storage device, comprising:
means to store data; and
a controller coupled to the means to store data, wherein the controller is configured to:
determine whether to aggregate data packets based upon whether the packet contains non-user data;
directly post a first packet to a host device without aggregating packets if the packet contains non-user data; and
perform speculative usage of a second packet before completing a protection check of the second packet.
19 . The data storage device of claim 18 , wherein the controller is further configured to perform a protection check and cancel the speculative usage upon determining the protection check fails.
20 . The data storage device of claim 18 , wherein the aggregated data packets are an integrity and data encryption (IDE) transaction layer packet (TLP) that includes an IDE TLP media access controller (MAC), wherein the IDE TLP MAC is a signature for protecting the IDE TLP, and wherein the signature is for all aggregated data packets of the IDE TLP.