IBM: SGIOP

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.

SGIOP

Prolog

Control Block Contents

SGIOP DSECT

Storage Layout

Cross Reference (Contains links to field and bit definitions)

SGIOP Prolog

 NAME       : HCPSGIOP
 DESCRIPTION: Synchronous General I/O Parameters
 DSECT      : SGIOP
 FUNCTION   : Describe the parameters of a Diagnose 'A8' request
 LOCATED BY : The "X" register contains the logical address of
              the SGIOP in Guest storage at the time Diagnose 'A8'
              is issued.
 CREATED BY : The program issuing Diagnose 'A8'.
 DELETED BY : N/A
 COMMENTS   : The SGIOP is fetched by CP from the VM's storage during
              Diagnose 'A8' initialization.  An updated version may be
              stored back in the virtual machine before the Diagnose
              instruction processing completes.

SGIOP Control Block Content


SGIOP DSECT
Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      SGIOP          Synchronous General I/O
                                        Parameters
0000    0 Signed       2 SGIDEVNO       The virtual device number of the
                                        device to be used.
0002    2 Bitstring    2 SGIOKF (0)     Key and Flag bytes.
0002    2 Bitstring    1 SGIKEY         The Storage Protection Key to use
                                        for I/O operations with this
                                        request.
0003    3 Bitstring    1 SGIFLG         General I/O request flag.
          00000080       SGIFMT         X'80' CCW format.
0004    4 Signed       4 SGIRESV1       Reserved for future IBM use.
0008    8 Address      4 SGICPA         Channel Program Address for this
                                        request.
000C   12 Signed       4 SGIRESV2       Reserved for future IBM use.
0010   16 Bitstring    8 SGICASC (0)    Combined CCW Address, Device &
                                        Subchannel status and Residual
                                        count fields.
0010   16 Address      4 SGICCWA        Address of CCW at Interrupt (+8).
0014   20 Bitstring    1 SGIDEVST       The Device Status byte, returned
                                        by CP.
0015   21 Bitstring    1 SGISCHST       The Subchannel Status byte,
                                        returned by CP
0016   22 Signed       2 SGIRESCT       The Residual Count, returned by
                                        CP.
0018   24 Bitstring    1 SGILPM         Path down which i/o is to be done
0019   25 Bitstring    1 SGIRESV3 (3)   Reserved for future IBM use.
001C   28 Signed       2 SGIRESV4       Reserved for future IBM use.
001E   30 Signed       2 SGISNSCT       The amount of sense data present.
0020   32 Signed       4 SGIRESV5       Reserved for future IBM use.
0024   36 Signed       4 SGIRESV6       Reserved for future IBM use.
0028   40 Signed       4 SGIRESV7       Reserved for future IBM use.
002C   44 Signed       4 SGIRESV8       Reserved for future IBM use.
0030   48 Signed       4 SGIRESV9       Reserved for future IBM use.
0034   52 Signed       4 SGIRESVA       Reserved for future IBM use.
0038   56 Bitstring   32 SGISDATA       The sense data (only if unit
                                        check is on in SGIDEVST).
          00000058       SGIBYLEN       *-SGIOP Length (in bytes) of
                                        SGIOP.
          0000000B       SGIDWSIZ       ((SGIBYLEN+7)/8) Size of SGIOP in
                                        Doublewords.
0008    8 Bitstring    3 *
000B   11 Bitstring    1 SGICPA3        Right-most byte for alignment
                                        test

SGIOP Storage Layout

*** SGIOP - Synchronous General I/O Parameters
*
*     +-------------+------+------+---------------------------+
*   0 |  SGIDEVNO   |SGIKEY|SGIFLG|         SGIRESV1          |
*     +-------------+------+------+---------------------------+
*   8 |          SGICPA           |         SGIRESV2          |
*     +---------------------------+------+------+-------------+
*  10 |         SGICCWA           |:DEVST|:SCHST|  SGIRESCT   |
*     +------+--------------------+------+------+-------------+
*  18 |SGILPM|     SGIRESV3       |  SGIRESV4   |  SGISNSCT   |
*     +------+--------------------+-------------+-------------+
*  20 |         SGIRESV5          |         SGIRESV6          |
*     +---------------------------+---------------------------+
*  28 |         SGIRESV7          |         SGIRESV8          |
*     +---------------------------+---------------------------+
*  30 |         SGIRESV9          |         SGIRESVA          |
*     +---------------------------+---------------------------+
*  38 |                                                       |
*     =                       SGISDATA                        =
*     |                                                       |
*     +-------------------------------------------------------+
*  58
*
*** SGIOP - Synchronous General I/O Parameters
*** Overlay for SGICPA in SGIOP
*
*     +--------------------+------+
*   8 |////////////////////|:CPA3 | C
*     +--------------------+------+
*
*** Overlay for SGICPA in SGIOP