This direct call entry point allows another kernel extension to send transactions to the SSA Adapter Device Driver. This is not valid for a user process. On completion the caller will be notified by an off level interrupt. See SSA_GET_ENTRY_POINT SSA Adapter ioctl operation.
The entry point address is the address returned in EntryPoint by the SSA_GET_ENTRY_POINT ioctl operation. The function takes a single parameter of type SSA_Ioreq_t which is defined in /usr/include/sys/ssa.h.
The fields of the SSA_Ioreq_t structure are used as follows:
This function does not return errors. The success or otherwise of the directive can be established by examining the directive status byte and transaction result fields which are set up in the SSA MCB. For details see SSA Adapter Technical Reference.
The SSA Adapter Device Driver, ssadisk SSA Disk Device Driver, SSA Subsystem Overview.