gtpg2m5eGeneral Macros

VALBC-Validate Storage Block Address

Use this general macro to validate a storage block address and determine whether the block is in use.

Format




CHECKIN
Specifies the address space containing the address specified in the BLOCK parameter. The CHECKIN parameter is required and one of these address spaces must be specified.

EVM
When specified, the block address is checked for validity in the EVM and is considered valid only if the address is within the ECB's virtual memory (EVM).

SVM
When specified, the block address is checked for validity in the SVM and is considered valid only if the address is within the system's virtual memory (SVM).

BLOCK=R1|Rm
This parameter indicates the block to be validated. The register specified contains the address of the storage block to be validated. This address can be either an SVA or an EVA address, but will be validated depending on the setting of the CHECKIN parameter.

The default assignment is R1.

TYPE=R0|Rn
The register specified in this parameter contains the storage block type. The default assignment is R0. The following types are supported:

L0
128 byte block

L1
381 byte block

L2
1055 byte block

L4
4095 byte block

LECB (L3)
Entry Control Block

LSWB
System Work Block

LIOCB
I/O Control Block

SAVREG
The specified volatile registers will be saved by the macro in the stack area or in the registers specified by the WKREG parameter. Up to 3 registers can be specified. Those registers are R0, R1, R2. If this keyword is omitted, none of the 3 registers will be saved. You should not save a volatile register if you expect it to contain an output parameter. The register will be overwritten with its original contents, since the reload is the last thing performed by the macro.

WKREG
The specified symbolic register names are free to be used by the macro to save the volatile registers coded on the SAVREG parameter. Up to 3 registers can be specified, but the standard linkage registers R13 through R2 cannot be used here. This parameter is used in conjunction with the SAVREG parameter to generate efficient code and enhance the performance of the macro. The number of registers specified by WKREG should be less than or equal to the number of registers specified by SAVREG. If this parameter is omitted or not used to its maximum capacity, code optimization is sacrificed.

Entry Requirements

Return Conditions

Programming Considerations

Examples

None.