Browse Prior Art Database

High Performance Bus Master Token Ring Device Driver

IP.com Disclosure Number: IPCOM000113779D
Original Publication Date: 1994-Oct-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 4 page(s) / 99K

Publishing Venue

IBM

Related People

Knox Jr, T: AUTHOR [+3]

Abstract

Described is an algorithm to provide a high performance device driver for use with the Personal Computer (PC) bus master token ring adapters. The high performance device driver provides the ability to maximize chained commands and scatter/gather operations through the use of an efficient algorithm.

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This is the abbreviated version, containing approximately 53% of the total text.

High Performance Bus Master Token Ring Device Driver

      Described is an algorithm to provide a high performance device
driver for use with the Personal Computer (PC) bus master token ring
adapters.  The high performance device driver provides the ability to
maximize chained commands and scatter/gather operations through the
use of an efficient algorithm.

The high performance device driver is designed to provide three
important functions:
  1.  To support multiple adapters, such that service to each
      adapter is fair.
  2.  To provide a means whereby each token ring adapter is
      optimally operational so as to maximize throughput.
  3.  To provide a minimized critical path length.

      The high performance device driver functions are designed to
provide the capability to maximize the operations of token ring
adapters, as used in PC's equipped with a Micro Channel*.  This is
done by maximizing the chained receive and transmit chains in both an
interrupt and polled methodology.  Services are provided in the form
of an efficient code structure that mana`es multiple adapters with
the shortest possible path lengths.  This, in turn, produces optimal
token ring throughput.  The device has the following eight features:
  1.  Interrupt driven by completion of the next received frame,
      or completion of the entire transmit chain from any adapter.
  2.  Once in control, the device driver masks further interrupts
      on all adapters and operates in 'polling mode' to minimize
      OS/2* kernel interrupt processing overhead.
  3.  Adds frames dynamically to be transmitted without disrupting
      the firmware execution on the adapter card.
  4.  Scatter/Gather capabilities of the adapter are used to
      elimi...