Use this system macro inline to establish addressability to the Common Link
Access to Workstation (CLAW) control blocks.
Format
- label
- A symbolic name can be assigned to the macro statement.
- BLKNAME=blkname
- The name of the block being requested. BLKNAME is a required
parameter.
- FOURKF
- Locked page for channel control word (CCW)
- ICADAP
- Adapter control block
- ICLAWB
- CLAW device interface block
- ICLAWG
- CLAW page structure
- ICLCON
- Connection control table
- ICLIBK
- Client control block
- ICLIOI
- Extension block for CLAW I/O interrupt
- ICLTRB
- Transaction control block
- ICMSGB
- Message control block
- ICNBLK
- Extension block for CLAW initialization
- ICPATH
- Path control block
- ICPERM
- Permanent work area
- ICPOLL
- POLL request extension block
- ICQBLK
- Message queue element structure
- ICRBLK
- Extension block for returning CLAW page
- ICRCCW
- Read channel CCW area
- ICTRCE
- Trace data structure
- ICWCCW
- Write channel CCW area
- ISCCDT
- CLAW device table
- ISCFDT
- File descriptor
- ISCIPT
- Internet Protocol (IP) address table.
- ADDR
- The SVM address of the requested block. The ADDR parameter is
required.
- addr
- An address.
- (Rx)
- A register containing the address.
- RADDR
- The system virtual memory (SVM) address of the requested block. The
RADDR parameter is optional.
- addr
- The SVM address.
- (Ry)
- A register containing the address.
- ERROR
- If an error occurs, processing resumes at the specified address.
The ERROR parameter is optional.
- addr
- An address.
- (Rz)
- The register containing the address of the error.
Entry Requirements
This macro is for use in the control program (CP) only.
Return Conditions
- Control is returned to the next sequential instruction (NSI).
- If an error occurs (for example, if no blocks of the specified type are
available), control resumes with the address specified by the ERROR parameter
or the program exits.
- The contents of all registers, except R0, R14, and R15, are preserved
across this macro call.
- R0 contains the return code. A zero return code indicates success
and a nonzero return code indicates an error.
Programming Considerations
This macro can be run on any I-stream.
Examples
- This call shows block ICLAWG being requested for address VCTADDR.
GCLAC BLKNAME=ICLAWG,ADDR=VCTADDR
- This call shows block ICLAWG being requested for the address found in
register R3.
GCLAC BLKNAME=ICLAWG,ADDR=(R3)