lowRISC / lowRISC/opentitan

[ROM] consider checking FIFO depth before sending data to HMAC/KMAC interfaces

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Type:FutureRelease
Dominant language
SystemVerilog
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Description

### Description

In the past we had the assumption that any FIFO overflows would be prevented by stalling the bus. This is not an ideal behavior given that we could end up in a situation where incoming interrupts can cause deadlock scenarios.

Adding to the ROM milestone for initial triage.

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First steps

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  3. Fork the repository and make your change on a branch.
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Research direction

No source file, test, or entry point is named. Start by tracing the ROM paths that send data to the HMAC/KMAC interfaces and inspect how FIFO fullness and bus stalling are currently handled; done should prevent FIFO overflow without creating the described interrupt-related deadlock scenario.

Written by the indexing model from the issue text.

Assessment

Domain
cryptography
Issue type
Feature
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
32/100

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