Type ASSEMBLE
Source Lines : 1,398
Fixes Applied : 21
Most Recent Version : Thursday, December 14, 1978
Last Fix ID : [HRC039DK]
Module
DMKVDA
Function
TO 'ATTACH' A REAL DEVICE TO A USER AS A VIRTUAL DEVICE,
OR TO DEDICATE ALL DEVICES ON A PARTICULAR CHANNEL TO A
SPECIFIED USER.
Attributes
REENTRANT, PAGEABLE, CALLED VIA SVC
Operation
1. THE INPUT LINE IS SCANNED VIA A CALL TO DMKVDCSC.
DMKVDCSC WILL SCAN THE COMMAND LINE VIA DMKSCNFD AND DMKCVTHB
TO OBTAIN AND CONVERT FROM HEX TO BINARY (WHERE APPROPRIATE)
THE REAL DEVICE, USERID, AND VIRTUAL DEVICE. IF ANY FIELDS
ARE OMITTED OR INVALID, AN ERROR CODE IS RETURNED TO THE
CALLER AND DMKVDA WILL ISSUE AN APPROPRIATE ERROR MESSAGE
BASED ON THE RETURN CODE RECEIVED. DMKCFCSC IS CALLED BY
DMKVDCSC TO SCAN THE FIRST COMMAND OPERAND TO DETERMINE IF
A RANGE OF REAL DEVICE ADDRESSES WAS SPECIFIED. IF MULTIPLE
ADDRESSES ARE SPECIFIED ON THE COMMAND LINE, A WORK AREA
IS OBTAINED AND ALL MULTIPLE REAL ADDRESSES ARE STORED IN
BINARY FORM IN THIS WORK AREA FOR LATER PROCESSING.
2. DMKVDCPS WILL BE CALLED TO PERFORM A PRESCAN WHEN A RANGE
OF REAL ADDRESSES OR MULTIPLE REAL ADDRESSES WERE SPECIFIED
ON THE COMMAND LINE. THE PURPOSE OF THE PRESCAN IS TO
DETERMINE THE NUMBER OF REAL DEVICES WHICH ARE LIKELY TO BE
ATTACHED ON THIS COMMAND EXECUTION AND TO ACQUIRE STORAGE
FOR VIRTUAL BLOCKS IN ADVANCE TO MINIMIZE REPEATED CALLS
TO DMKFRE LATER BY DMKVDS. DMKVDCPS WILL BE CALLED ONLY
WHEN MULTIPLE REAL ADDRESSES OR A RANGE OF REAL ADDRESSES
WERE SPECIFIED ON THE COMMAND LINE.
3. DMKSCNRU IS CALLED TO FIND RDEVBLOK FOR THE REAL DEVICE
(ERROR RETURNED IF NOT FOUND). DMKSCNAU IS CALLED TO FIND
THE ACTIVE USER FOR WHOM THE ATTACH IS SPECIFIED (ERROR
RETURNED IF HE IS NOT LOGGED ON). DMKSCNVU IS CALLED TO
ENSURE THAT THE VIRTUAL DEVICE DOES NOT ALREADY EXIST
(ERROR RETURNED IF IT DOES).
4. A CALL IS MADE TO DMKVDEDC TO VERIFY DEVICE
EXISTENCE. SETS UP AN I/O TASK (TIO) TO SEE IF
THE DEVICE EXISTS. IF THE DEVICE DOES NOT EXIST,
IT IS MARKED OFFLINE AND A 'DOES NOT EXIST' MESSAGE
IS ISSUED FROM DMKVDA.
FOR DASD, DMKVDEDC WILL SET UP AND EXECUTE AN
I/O TASK TO READ THE DASD VOLUME LABEL OF THE DEVICE
BEING ATTACHED. IF SUCCESSFUL, THE VOLUME SERIAL
IS INSERTED INTO THE 'RDEVSER' FIELD OF THE REAL
DEVICE BLOCK. AN ERROR RETURN CODE IS PASSED BACK TO
DMKVDA IF FAILURE ENCOUNTERED ON THE READ. A FLAG
IS SET IF IT IS A CP/370 OWNED VOLUME.
IF DMKVDEDC WAS CALLED WITH PARM = 1, INDICATING
ALLOCATION DATA IS PRESENT, THE ALLOCATION
RECORD IS READ INTO FREE STORAGE.
5. IF THESE TESTS ARE SATISFACTORY, THEN DMKVDSAT IS CALLED
TO ATTACH THE GIVEN REAL DEVICE AS A VIRTUAL DEVICE. IF AN
ERROR RETURN OCCURS FROM DMKVDSAT, THEN THE ERROR CODE IS
RETURNED TO THE CALLER OF DMKVDAAT AND AN ERROR MESSAGE IS
SENT.
6. IF DMKVDSAT WAS SUCCESSFUL, A MESSAGE IS
SENT TO THE USER INDICATING THE DEVICE HAS BEEN ATTACHED;
AN ADDITIONAL MESSAGE IS SENT TO THE CALLER INDICATING THAT
THE DEVICE HAS BEEN ATTACHED. IF THE CALLER IS NOT THE
SYSTEM OPERATOR, A MESSAGE IS SENT TO THE SYSTEM OPERATOR
INDICATING WHAT DEVICE WAS ATTACHED BY WHAT CALLER TO WHAT
USER.
7. PROCESSING WILL CONTINUE IF AN ERROR IS ENCOUNTERED WHILE
PROCESSING MULTIPLE REAL ADDRESSES OR A RANGE. AN ERROR
MESSAGE WILL BE ISSUED FOR THE DEVICE ADDRESSES IN ERROR.
A RESPONSE TYPE MESSAGE WILL ALSO BE ISSUED FOR THOSE REAL
ADDRESSES IN THE RANGE WHICH COULD BE ATTACHED OR THOSE
MULTIPLE ADDRESS IN THE COMMAND LINE WHICH COULD BE
ATTACHED.
8. FOR THE ATTACH CHANNEL COMMAND, A CHECK IS MADE TO ENSURE
THAT THE COMMAND LINE IS CORRECT VIA A CALL TO DMKVDCSC.
DMKVCHDC IS THEN CALLED TO ATTACH THE CHANNEL AND MARK ALL
CONTROL UNITS AND DEVICES ON THE CHANNEL AS DEDICATED.
Calls to Other Routines
DMKSSSVA
DMKSSSAS
DMKSTKCP
DMKSCNRN
DMKSCNRU
DMKSCNAU
DMKSCNVU
DMKSCNVS
DMKVDSAT
DMKCVTBH
DMKQCNWT
DMKFREE
DMKLOCKQ - LOCK USERID
DMKLOCKD - UNLOCK USERID
DMKVCHDC
DMKVDCPS - PRESCAN
DMKVDCAL - ALLOCATION ROUTINE
DMKVDCSC - SCAN COMMAND LINE
DMKSYSOW
DMKSYSOC
DMKVDERR - PUT OUR 'ATTACH' ERROR MESSAGES
DMKVDEDC - READ LABEL/ALLOCATION RECORD