NAME
iopaau —
Intel I/O Processor
Application Accelerator Unit
SYNOPSIS
iopxs* at mainbus?
iopaau* at iopxs?
DESCRIPTION
The Application Accelerator Unit, or AAU, provides hardware-assisted support for
performing block fills on a region of memory, XOR of multiple regions of
memory (parity computation), and parity verification.
The
iopaau driver supports the Application Accelerator Units
on the following Intel I/O Processors:
- Intel i80321 I/O Processor
The
iopaau driver provides a back-end to the
dmover(9) interface, and
supports the following
dmover(9) functions:
-
-
- zero
- Zero a region of memory
-
-
- fill8
- Fill a region of memory with an 8-bit value
-
-
- copy
- Copy a region of memory
-
-
- xor2
- Perform an XOR of 2 input streams
-
-
- xor3
- Perform an XOR of 3 input streams
-
-
- xor4
- Perform an XOR of 4 input streams
-
-
- xor5
- Perform an XOR of 5 input streams
-
-
- xor6
- Perform an XOR of 6 input streams
-
-
- xor7
- Perform an XOR of 7 input streams
-
-
- xor8
- Perform an XOR of 8 input streams
SEE ALSO
dmover(9)
HISTORY
The
iopaau device first appeared in
NetBSD
2.0.
AUTHORS
The
iopaau driver was written by
Jason R.
Thorpe
<
thorpej@wasabisystems.com>
and contributed by Wasabi Systems, Inc.
BUGS
Due to limitations in how scatter-gather is done by the AAU hardware, a given
DMA segment must be the same length for the output stream and each input
stream. The easiest way to achieve this is to ensure that all streams used in
an AAU operation begin at the same offset into a page.