Automatic Configuration for Control Units

Automatic Configuration for Control Units

      This disclosure provides the means by which a more flexible
system management environment can be provided for serially switched
I/O attachment mechanisms.  It provides automated detection and
inclusion of system resources without operator intervention, both at
system initialization and during system operations.  It also provides
system reconfiguration without manual manipulation of physical
resource information.

      The Figure describes the proposed system structure to be used
for automatic I/O configuration by this disclosure:

System configuration for automatic I/O configuration

      Terminology:

CHSC      Channel Subsystem Call: the mechanism by which S/390

CHSC

CHSC

CHSC
          channel subsystems are dynamically updated.

CM        Configuration Manager (described below)

CM

CM

CM

CPC       Central Processor Complex

CPC

CPC

CPC

CSS       Channel Subsystem

CSS

CSS

CSS

CU        Control Unit

CU

CU

CU

PCE       Processor Controller Element: a service processor directly

PCE

PCE

PCE
          attached to an S/390 CPC.

The components described below provide the primary functions required
by the invention described in this disclosure.

      The Configuration Repository contains customer configuration
constraints against the physical system configuration.  In other
words, it defines what portion of the physical I/O configuration is
to be actually configured.  Typically, the contents of this
repository are driven by performance and availability requirements
and are manually entered by the customer.  This disclosure assumes
that such data resides in the Processor Controller Element (PCE).

The Configuration Manager provides the following functions:

o   Retrieves physical link configuration data from CSS

o   Initiates communication with each I/O subsystem

o   Consolidates configuration data from each I/O subsystem into a
    single set of configuration records

o   Initializes the channel subsystem

o   Monitors I/O subsystems during system operations to detect and
    process any changes to system configuration

This disclosure assumes that the Configuration Manager resides in the
Processor Controller Element (PCE).

      The I/O subsystem configuration process provides the following
functions:

o   Collects I/O subsystem configuration data at time of
    initialization

o   Monitors I/O subsystem configuration data during system
    operations

o   Responds to requests for information from the configuration
    manager

o   Automatically reports detected I/O subsystem configuration
    changes to the configuration manager

It is located in an I/O control unit and is a required component in
each I/O subsystem.

      A dynamic switch control unit serves as the physical level
coordinator during initialization.  The primary unique function
provided by the dynamic switch control unit w...