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:
| Field | Description |
|---|---|
| SsaDPB | An array of size SSA_DPB_SIZE which is used by the SSA Adapter Device Driver and should be initialized to all NULLs. |
| SsaNotify | The address of the function in the SSA head device driver which the SSA Adapter Device Driver calls when the directive has completed. |
| u0 | This is the transaction to be executed. Valid transactions are described in the Technical Reference for the adapter. |
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 the Technical Reference for tha adapter.