Adapter discovery
The cryptographic device driver provides two misc device nodes, one for cryptographic requests, and one for a device from which random numbers can be read.
Cryptographic adapters are detected automatically when the device driver is started. They are reprobed periodically, and following any hardware problem.
Upon detection of a cryptographic adapter, the device driver presents a Linux® misc device, z90crypt, to user space. A user space process can open the misc device to submit cryptographic requests to the adapter through IOCTLs.
If at least one of the detected cryptographic adapters is a CCA coprocessor, an additional misc device, hwrng, is created from which random numbers can be read.
You can set cryptographic adapters online or offline in the device driver. The cryptographic device driver ignores adapters that are configured offline even if the hardware is detected. The online or offline configuration is independent of the hardware configuration.