T6EXIT — Type 6 exit

Description

The T6EXIT macro returns control from a type 6 SVC. This exit macro can only be used in a type 6 SVC routine.

Environment

The requirements for the caller are:

Environmental factor	Requirement
Minimum authorization:	Supervisor state and PSW key 0
Dispatchable unit mode:	Task
Cross memory mode:	PASN=HASN=SASN
AMODE:	24- or 31-bit
ASC mode:	Primary
Interrupt status:	Disabled for I/O and external interrupts
Locks:	No locks held
Control parameters:	None

Programming requirements

The caller must include the CVT mapping macro with DSECT=YES specified.

Restrictions

None.

Input register information

On input, general purpose register (GPR) 1 must point to a service request block (SRB) if RETURN=SRB is specified.

Output register information

For RETURN=CALLER, registers 0, 1, and 15 are returned from the type 6 SVC routine to the calling program (the issuer of the SVC). For RETURN=DISPATCH and RETURN=SRB, no registers are returned to the calling program.

Performance implications

None.

Syntax

The T6EXIT macro is written as follows:

Syntax	Description

`name`	`name`: Symbol. Begin `name` in column 1.

␢	One or more blanks must precede T6EXIT.

T6EXIT

␢	One or more blanks must follow T6EXIT.

RETURN=CALLER	Default: RETURN=CALLER

RETURN=DISPATCH

RETURN=SRB

Parameter

The explanation of the RETURN parameter is as follows:

RETURN

Specifies how the type 6 SVC has chosen to exit, which is one of the following:

CALLER specifies that the return is directly to the caller or issuer of the SVC. The contents of GPRs 0, 1, and 15 at the time of the T6EXIT are returned to the issuer of the SVC. CALLER is the default return option.
DISPATCH specifies that the return should be to the system to dispatch other work. This function is for the use of routines that have suspended the current task. When the task resumes, the issuer of the type 6 SVC receives control at the instruction after the SVC.
SRB specifies that the system should immediately dispatch an SRB. This SRB must:
- Be initialized by the type 6 SVC.
- Be pointed to by register 1.
- Run in the same address space as the SVC. The SRB has the same format as an SRB dispatched through the SCHEDULE macro.

ABEND codes

None.

Return and reason codes

None.

Example

Terminate type 6 SVC processing and return control from the type 6 SVC to the caller of the SVC.

T6EXIT  RETURN=CALLER