Type ASSEMBLE
Source Lines : 1,302
Fixes Applied : 14
Most Recent Version : Monday, January 22, 1979
Last Fix ID : [R13026DK]

Module

       DMKMCH

Function

        THE FUNCTION OF THIS ROUTINE IS TO DETERMINE THE SEVERITY OF
        A MACHINE CHECK AND ATTEMPT TO CORRECT THE MALFUNCTION.
        DIAGNOSTIC MESSAGES  FOR THE SYSTEM OPERATOR, AND ERROR DATA
        FOR THE F.E. PERSONNEL USE WILL BE PRODUCED AS OUTPUT.

Attributes

        RESIDENT,ENTERED DIRECTLY VIA MC NEW PSW

Operation

        DMKMCHIN
        1. RECEIVES CONTROL WHEN A MACHINE CHECK INTERRUPT CAUSES THE
           MC NEW PSW TO BE LOADED

        2. INITALLY DISABLES BOTH HARD AND SOFT MACHINE CHECKS WHILE
         DETERMINING THE SEVERITY OF THE ERROR. WHEN IT IS DETERMINED
         THAT THE ERROR IS NOT ONE THAT REQUIRES SYSTEM TERMINATION
         THEN HARD MACHINE CHECK INTERRUPTS WILL BE RE-ENABLED.

        3. IF THE ERROR IS ONE THAT SHOULD TERMINATE SYSTEM OPERATION,
         AND THE SYSTEM IS IN ATTACHED PROCESSOR MODE, CONTROL WILL
         BE GIVEN TO DMKMCTPT, THE PROCESSOR TERMINATION ROUTINE FOR
         ATTACHED PROCESSING. FOR UNIPROCESSING MODE,
         A DIRECT I/O OPERATION TO THE SYSTEM OPERATOR INFORMING
         HIM OF THE FAILURE, AND RECOMMENDED ACTION TO BE PERFORMED
         WILL BE DONE IF CONSOLE IS ACCESSABLE, FOLLOWED BY DMKMCH
         PLACING THE SYSTEM IN A DISABLED WAIT STATE.
           IF THE ERROR AFFECTS ONLY THE VIRTUAL USER, THE ERROR WILL
         BE RECORDED AND A MESSAGE WILL BE SENT TO THE AFFECTED USER.
         THE VIRTUAL MACHINE WILL BE RESET AND PLACED IN
         CP CONSOLE FUNCTION MODE. THE VIRTUAL= REAL USER
         WILL BE TERMINATED AND LOGGED OFF IF A STORAGE ERROR
         HAS OCCURRED.

        4. BEFORE ANY SYSTEM FUNCTIONS ARE USED, THE MACHINE CHECK
         HANDLER WILL ATTEMPT TO GET THE GLOBAL SYSTEM LOCK. IF THE
         LOCK IS UNAVAILABLE, CPMCHLK WILL BE SET TO ALLOW PROCESSING
         TO CONTINUE WHEN THE LOCK IS AVAILABLE. DMKMCHSE WILL RECEIVE
         CONTROL FROM THE DISPATCHER WHEN CPMCHLK IS ON.
         IF ANY MACHINE CHECKS OCCUR DURING THIS PROCESSING, THEY
         WILL BE VIEWED AS RECURSIVE MACHINE CHECKS.
         CPMCHLK PREVENTS THE DISPATCHER FROM DISPATCHING ANY
         NEW WORK FOR THAT PROCESSOR UNTIL THE MACHINE CHECK
         INTERRUPT IS HANDLED.


        5. ON SOFT ERRORS THE SYSTEM OPERATOR WILL BE INFORMED, A TEST
         WILL BE MADE TO DETERMINE IF ANY SOFT ERROR THRESHOLDS HAVE
         BEEN EXCEEDED, THE ERROR WILL BE RECORDED, AND CONTROL WILL
         BE RETURNED TO THE INTERRUPTED PROGRAM.

        6. ON SPF AND MULTI-BIT ECC ERRORS AN ANALYSIS WILL BE MADE TO
         DETERMINE IF THE DAMAGE CAN BE REFRESHED OR NOT. ADDITIONALLY
         A FUNCTIONAL TEST OF THE FAILING FRAME OF STORAGE WILL BE
         PERFORMED TO DETERMINE IF THAT FRAME SHOULD BE REMOVED FROM
        SYSTEMS USE.

        7. A THRESHOLD COUNT FOR ALL SOFT MACHINE CHECKS WILL
           BE KEPT AND WHEN THE THRESHOLD COUNT EXCEED THE
           MAX. VALUE, THE SOFT MACHINE CHECKS WILL BE DISABLE
           FOR SOFT INTERRUPTS FOR BOTH PROCESSORS.

        8. THE SYSTEM OPERATOR WILL BE INFORMED OF ANYTIME
           THE MACHINE IS DISABLED FOR SOFT MACHINE CHECKS.

Calls to Other Routines

        DMKIOEMC - TO RECORD FORMATTED MACHINE CHECK RECORDS
                   GPR6 = FORMATTED MACHINE CHECK RECORD ADDRESS
                   GPR7 = LENGTH OF MACHINE CHECK RECORD
        DMKQCNWT - TO SEND MESSAGES TO A VIRTUAL MACHINE AND THE
                   SYSTEM OPERATOR
        DMKPTRFT - TO PURGE DEFECTIVE PAGE IN STORAGE
        DMKFREE  - TO GET STORAGE FOR CPEXBLOKS
        DMKSTKOP - TO STACK A CPEXBLOK FOR THE OTHER PROCESSOR
        DMKPGSPO - TO RELEASE USER'S VIRTUAL STORAGE
        DMKCFMBK - TO PUT USER IN CONSOLE FUNCTION MODE
        DMKCFPRR - TO RESET VIRTUAL MACHINE
        DMKOPRWT - TO WRITE EMERGENCY MESSAGE TO SYSTEM OPERATOR
        DMKMCTPT - TERMINATE THE AILING PROCESSOR
        DMKMCTST - TERMINATE THE SYSTEM