The IOSUPFA macro obtains the address of the UCB prefix extension segment. To map the UCB prefix extension segment, use the IOSDUPFX mapping macro.
The IOSUPFA macro provides faster performance than the UCBLOOK macro; however, if the caller uses UCBLOOK to obtain several addresses in the same invocation, UCBLOOK might provide better performance than an IOSUPFA macro and an IOSCMXA macro. The UCBLOOK macro also validates input parameters and provides recovery.
The requirements for the caller are:
Environmental factor | Requirement |
---|---|
Minimum authorization: | Problem state and any PSW key |
Dispatchable unit mode: | Task or SRB |
Cross memory mode: | Any PASN, any HASN, any SASN |
AMODE: | 31-bit |
ASC mode: | Primary |
Interrupt status: | Enabled or disabled for I/O and external interrupts |
Locks: | The caller may hold locks, but is not required to hold any. |
Control parameters: | The input parameter must be in the primary address space. If the caller is disabled, the parameter list must reside in fixed or disabled reference (DREF) storage. |
The caller must pass a valid captured or actual UCB address.
The caller must pin the UCB or otherwise guarantee that the UCB will not be deleted. (If the caller issues a UCBLOOK macro with the PIN parameter to pin the UCB, use the UCBLOOK UCBPXPTR parameter rather than the IOSUPFA macro.)
The caller must supply recovery to handle any unexpected errors, such as abends.
None.
Before issuing the IOSUPFA macro, the caller does not have to place any information into any register unless using it in register notation for a particular parameter, or using it as a base register.
None.
The standard form of the IOSUPFA macro is written as follows:
Syntax | Description |
---|---|
name | name: symbol. Begin name in column 1. |
␢ | One or more blanks must precede IOSUPFA. |
IOSUPFA | |
␢ | One or more blanks must follow IOSUPFA. |
UCBPTR=ucbptr addr | ucbptr addr: RX-type address or register (2) - (12). |
,UCBPADDR=ucbpaddr addr | ucbpaddr addr: RX-type address or register (2) - (12). |
The parameters are explained as follows:
None.
None.