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Programming Interface Information:
This information is NOT
intended to be
used as Programming Interfaces of VM/ESA. It is to be used for diagnosis only. |
IFSNT
Cross Reference (Contains links to field and bit definitions)
IFSNT Prolog
NAME : HCPIFSNT
DESCRIPTION: INTERPRETATION FACILITY SUBCHANNEL NUMBER TABLE
DSECT : IFSNT
FUNCTION : TO ALLOW THE MICROCODE TO DETERMINE IF A SIOF
INSTRUCTION ISSUED, UNDER SIE, BY THE V=R GUEST SHOULD
BE PASSED THROUGH OR CAUSE INTERCEPTION.
THE IFSNT IS A 16K TABLE ON A PAGE FRAME BOUNDARY. IT IS
CONTAINED IN FIXED, CONTIGUOUS REAL STORAGE. IT CONTAINS
ONE ENTRY (4 BYTES LONG) FOR EACH DEVICE THAT COULD BE
SUPPORTED UNDER I/O PASS THROUGH. IT IS ONLY APPLICABLE
FOR A 370 V=R GUEST. DEVICES WITH ADDRESSES 000 THRU
FFF ARE SUPPORTED UNDER I/O PASS THROUGH.
THE MICROCODE USES THE DEVICE ADDRESS OPERAND OF THE
SIOF INSTRUCTION TO INDEX INTO THE IFSNT. IF THE FIRST
BYTE OF THE ENTRY IS NON-ZERO, THE SIOF INSTRUCTION
IS ELIGIBLE TO BE PASSED THROUGH. THE FIRST BYTE THEN
CONTAINS THE LOGICAL PATH MASK (LPM) TO BE PLACED IN THE
OPERATION REQUEST BLOCK (ORB) CONSTRUCTED BY THE
MICROCODE. IF THE FIRST BYTE OF THE ENTRY IS ZERO, SIOF
MUST CAUSE INTERCEPTION.
THE SECOND BYTE IS RESERVED AND THE THIRD AND FOURTH
BYTES CONTAIN THE SUBCHANNEL NUMBER.
LOCATED BY : THE ADDRESS OF THE REAL STORAGE IS CONTAINED IN SYSVRIFS
WHENEVER CP CAN ALLOCATE SUFFICIENT STORAGE.
WHEN A 370 V=R GUEST IS OPERATING UNDER I/O PASS THROUGH
THE ADDRESS OF THE INITIALIZED TABLE IS IN SIESNORG OF
THE BASE VMDBK.
CREATED BY : HCPIOAIT, HCPIOAGS
DELETED BY : HCPIOARC, HCPIOARS
IFSNT Control Block Content
IFSNT DSECT
Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure IFSNT INTERPRETATION FACILITY SUBCHANNEL NUMBER TABLE 0000 0 Bitstring 1 IFSNTLPM IF NON-ZERO, SIOF CAN BE PASSED THROUGH FOR THIS DEVICE. THIS BYTE CONTAINS LPM FOR MICROCODE BUILT ORB. IF ZERO, SIOF MUST CAUSE INTERCEPTION. 0001 1 Bitstring 1 * RESERVED FOR FUTURE IBM USE 0002 2 Signed 2 IFSNTSNO SUBCHANNEL NUMBER FOR THIS DEVICE 00004000 IFSNTLEN 4096*4 LENGTH OF IFSNT 00000004 IFSNTFCT 4 NUMBER OF FRAMES NEEDED FOR THE IFSNT
IFSNT Storage Layout
*** IFSNT - INTERPRETATION FACILITY SUBCHANNEL NUMBER TABLE * * +------+------+-------------+ * 0 |:NTLPM|//////| IFSNTSNO | 4 * +------+------+-------------+ * *** IFSNT - INTERPRETATION FACILITY SUBCHANNEL NUMBER TABLE
IFSNT Cross Reference
(contains links to field and bit definitions)Symbol Dspl Value -------------- ---- -----IFSNTFCT 0002 00000004
IFSNTLEN 0002 00004000
IFSNTLPM 0000
IFSNTSNO 0002
Last updated on 3 Aug 1999 at 12:05:43 EDT.
Copyright IBM Corporation, 1990, 1999