Request processing

Cryptographic adapters process requests asynchronously.

The device driver detects request completion either by standard polling, a special high-frequency polling thread, or by hardware interrupts. Hardware interrupt support is only available for Linux instances that run in an LPAR. If hardware interrupt support is available, the device driver does not use polling to detect request completion.

All requests to either of the two misc devices are routed to a cryptographic adapter using a crypto request scheduling function that, for each adapter, takes into account:
  • The supported functions
  • The number of pending requests
  • A speed rating