78 lines
2.8 KiB
Groff
78 lines
2.8 KiB
Groff
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.\" Copyright (c) 2016 Ruslan Bukin <br@bsdpad.com>
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.\" All rights reserved.
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.\"
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.\" This software was developed by SRI International and the University of
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.\" Cambridge Computer Laboratory under DARPA/AFRL contract FA8750-10-C-0237
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.\" ("CTSRD"), as part of the DARPA CRASH research programme.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" SUCH DAMAGE.
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.\"
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.\" $FreeBSD$
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.\"
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.Dd December 12, 2016
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.Dt XDMA 4
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.Os
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.Sh NAME
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.Nm xdma
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.Nd DMA abstraction layer
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.Sh SYNOPSIS
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To compile xDMA device support into the kernel, place the following line
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in your kernel configuration file:
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.Bd -ragged -offset indent
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.Cd "device xdma"
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.Ed
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.Pp
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To compile xDMA FDT-based test driver, place the following line as well:
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.Bd -literal -offset indent
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.Cd "device xdma_test"
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.Ed
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.Sh DESCRIPTION
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xDMA is a DMA framework designed to abstract the interaction between device
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drivers and DMA engines.
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.Pp
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xDMA defines an interface for efficient interaction between the device driver
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and DMA controller.
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The
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.Nm
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device provides a virtual DMA controller and virtual channels called xchans.
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The controller provides virtual channels management (allocation, deallocation,
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configuration) and interrupt notification esteblishment needed to receive
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events from the hardware DMA controller.
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.Nm
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supports the following transfer types:
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.Bl -hang -offset indent -width xxxxxxxx
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.It Nm Cyclic
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A non-stop periodic transfer designed for applications like audio.
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.It Nm Memcpy
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A memory-to-memory transfer.
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.El
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.Sh SEE ALSO
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.Xr bus_dma 9
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.Sh HISTORY
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Support for xDMA first appeared in
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.Fx 12.0 .
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.Sh AUTHORS
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.An -nosplit
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.Fx
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xDMA framework was first added by
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.An Ruslan Bukin Aq Mt br@FreeBSD.org .
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