VSMREGN — Obtain private area region size

Description

The VSMREGN macro provides the virtual starting address and sizes of the private area user regions associated with a given TCB in the current address space. For more information about the user region, see z/OS MVS Initialization and Tuning Guide.

Environment

The requirements for the caller are:

Environmental factor	Requirement
Minimum authorization:	Problem state and PSW key 8-15.
Dispatchable unit mode:	Task or SRB.
Cross memory mode:	Any PASN, any HASN, any SASN.
AMODE:	24- or 31-bit. All addresses passed to VSMREGN must be 31-bit addresses.
ASC mode:	Primary.
Interrupt status:	Enabled or disabled for I/O and external interrupts.
Locks:	If obtaining user region information for the currently active task by specifying its TCB address or by taking the default value for the TCB keyword, the caller is not required to hold any locks. Otherwise, the caller must hold the local lock of the currently addressable address space.
Control parameters:	Must be in the primary address space. All input parameters except for the TCB address can reside above 16 megabytes if the caller is running in 31-bit addressing mode. The TCB resides below 16 megabytes.

Programming requirements

None.

Restrictions

None.

Input register information

Before issuing the VSMREGN macro, the caller must ensure that the following general purpose registers (GPRs) contain the specified information:

Register: Contents
13: Address of a standard 72-byte save area

Output register information

When control returns to the caller, the GPRs contain:

Register: Contents
0-1: Used as work registers by the system
2-13: Unchanged
14: Used as a work register by the system
15: Return code

When control returns to the caller, the ARs contain:

Register: Contents
0-1: Used as work registers by the system
2-13: Unchanged
14-15: Used as work registers by the system

Some callers depend on register contents remaining the same before and after issuing a service. If the system changes the contents of registers on which the caller depends, the caller must save them before issuing the service, and restore them after the system returns control.

Performance implications

None.

Syntax

The VSMREGN macro is written as follows:

Syntax	Description

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

␢	One or more blanks must precede VSMREGN.

VSMREGN

␢	One or more blanks must follow VSMREGN.

WKAREA=`addr`	`addr`: RX-type address or register (0) - (12).

,TCB=`tcb addr`	`tcb addr`: RX-type address or register (0), (2) - (12).
	Default: (except for SRB routines) TCB address in PSATOLD.

Parameters

The parameters are explained as follows:

WKAREA=addr

Indicates the virtual address of a 16-byte work area, which is used by VSMREGN to return the requested information. The format of the work area is:

Bytes: Meaning
0-3: Virtual address of the region below 16 megabytes
4-7: Length of the region below 16 megabytes
8-11: Virtual address of the region above 16 megabytes
12-15: Length of the region above 16 megabytes

,TCB=tcb addr

Indicates the virtual address of the TCB to be used to identify the region (the region control task (RCT) region, the V=V region, or the V=R region). SRB routines and routines whose currently addressable address space is not the home address space must specify the TCB operand. They cannot use the default value.

ABEND codes

None.

Return and reason codes

When control returns from VSMREGN, GPR 15 always contains a return code of zero, indicating successful completion.

Example 1

Find the virtual address and length of the private area of the TCB whose address is in PSATOLD. Return the information in the work area whose address is given in register 2.

VSMREGN WKAREA=(2)

Example 2

Find the virtual address and length of the private area of the TCB specified in register 3. Return this information in the work area whose address is given in register 2.

VSMREGN WKAREA=(2),TCB=(3)

Example 3

Find the virtual address and length of the private area of the TCB whose address is X. Return this information in the work area whose address is given in register 2.

VSMREGN WKAREA=(2),TCB=X

Example 4

Find the virtual address and length of the private area of the TCB whose address is given in register 3. Return this information in the work area whose address is X.

VSMREGN WKAREA=X,TCB=(3)