gtpi1m28 | System Installation Support Reference |
User exit routine UCCSVW is invoked by those SVC macros that have a wait or
implied wait, and that return to the issuer of the macro by an LPSW CE1PSW
instruction in a postinterrupt routine. UCCSVW is invoked just before
issuing the LPSW
instruction if the SVW exit point is active. Exit point SVW is in CSECT
CCNUCL.
General Conditions at Entry
The registers at entry to UCCSVW are:
- R0-R7
- The contents have been restored from the ECB and contain the data that is
being returned to the E-type program that issued the macro.
- R8
- Base of the E-type program that is to receive control.
- R9
- Address of the ECB.
- R11-R15
- See User Exit Routines - Common Entry Conditions.
System Conditions at Entry
- System state
- Supervisor
- System mask
- Masked for I/O
- Protect key
- 0
- Address Space
- SVM or EVM.
Programming Considerations at Entry
- Usually, the address space active at the time of the user exit depends on
the processing of the postinterrupt routine. Most postinterrupt
routines can complete all of their processing in the SVM. For some
interrupt routines it is necessary to switch to the EVM, where they will
complete their processing. They are not required to switch back to the
SVM before returning to the macro decoder.
- To preserve the integrity of the stack, user processing must
not issue an SVC macro.
- See User Exit Routines - Common Entry Conditions.
- See User Exit Routines - Common Programming Considerations for other considerations.
Programming Considerations on Return
See User Exit Routines - Common Return Conditions.
General Conditions on Return
See User Exit Routines - Common Return Conditions.