DIAGNOSE Code X'80' -- MSSFCALL I Privilege class G DIAGNOSE code X'80' is the VM/SP interface for communicating between CP and the Monitoring and Service Support Facility (MSSF). MSSF is a hardware
component of the processor controller of the 3081 processor complex; it provides
system configuration and storage information for the 3081 processor complex.
Entry Values: Rx is a user-specified register that contains the address of the MSSF data block (MSFBLOK). MSFBLOK is defined in increments of 8 bytes to a max­
imum of 2048 bytes. It must be aligned on a 2K boundary. MSFBLOK is locked
in storage during the MSSFCALL request.
Ry is a user-specified register that contains the MSSF command word representing
the function that MSSF is to perform. (See MSSF command words below.) Usage: The CP module DMKMHC issues a real DIAGNOSE X'80' and services all MSSF external interruptions. DMKMHC issues a real DIAGNOSE X'80' when:
1. The operator issues a V AR Y ONLINE PROCESSOR nn command or a
VARY OFFLINE PROCESSOR nn VPHY command. (These commands
modify the real processor configuration to bring the processor physically online
or offline.)
2. A V=R virtual machine running in EC mode issues the MSSF command word SCPINFO.6 (Operating systems running in a virtual machine use the MSSF SCPINFO command to get information about a system configuration and stor­
age allocation.
3. A user with privilege class C or E runs the IOCP program to read from or write
to the Input/Output Configuration Data Set (IOCDS). When CP ISSUES DIAGNOSE X'80', the hardware call block that is created
(HCBLOK) contains the MSFBLOK address, the MSSF command word, and the
address to return to after the MSSF has processed the request. See VM / SP Data
Areas and Control Block Logic, Volume 1 for the format of the MSFBLOK and
HCBLOK.
MSSF COMMAND WORDS X'0011nn01 ' VARY ONLINE PROCESSOR nn where nn is the ID of the
processor to be varied online. CP use only. X'0010nn01' V AR Y OFFLINE PROCESSOR nn VPHY where nn is the ID
of the processor to be physically varied offline. CP use only. X'00020001' SCPINFO command. Virtual machine use only.
6
When a V = V virtual machine issues SCPINFO, DMKMHV does not pass control to DMKMHC.
CP does not issue the DIAGNOSE X'80' but simulates the MSSF response and returns prede­
fined data and status codes to the user. See VM/SP System Logic and Problem Determination
Guide, Volume 1 -CP for a description of the pre-defined data. DIAGNOSE Instruction in a Virtual Machine 265
X'00400002' X'00400102' X'00410002' X'00410102' IOCP special command to obtain or release the IOCP write
lock. IOCP WRITE to Level 1 IOCDS. IOCP READ from Level 0 IOCDS. IOCP READ from Level 1 IOCDS. Completion and Condition Codes: Two possible condition codes returned for
DIAGNOSE X'80' are: cc=O MSSF is processing the MSSFCALL request.
cc=2 MSSF is busy.
Note: If CP issued the MSSFCALL request, and MSSF was already processing a
previous MSSFCALL request, abend MHC001 occurs. If a V=R user issued the
request, CP reflects the condition code (2) to the virtual machine's PSW. At the completion of an MSSFCALL, the following actions occur: MSSF generates a service signal interrupt, external interrupt X'240 l' (class 24
external interrupt). This interrupt stores the absolute address of the MSSF
data block (MSFBLOK) at decimal locations 128-131 in the virtual machine's PSA. Bit 22 of control register 0 controls masking of the service signal. MSSF passes a completion status code back in the MSFBLOK. CP returns control to the address specified in HCBLOK. If tracing is on, trace table entry X'17' traces all MSSFCALL requests. Refer
to "Figure 8. CP Trace Table Entries" for the format and content of the entry.
In addition, trace table entry X'O l' reflects external interrupt X'240 l' when
the MSSF generates the service signal interrupt to CP. Successful MSSF completion status codes are: 0010 - SCPINFO complete. 0020 - The processor is varied online/offline. 0120 - The processor is already varied online/offline. IOCP operation com­
plete. 8020 - An IOCP READ is invalid because the file is open for writing. 4020 - The IOCP read or write operation was performed on the active IOCDS. 2020 - The active IOCDS has been written to.
Reject status codes are: 01FO - Invalid command code or identification byte. 41FO - Attempt to read closed IOCDS. 266 VM/SP System Programmer's Guide /'
Previous Page Next Page