linux-imx

/*

** ccio-dma.c:

**  DMA management routines for first generation cache-coherent machines.

**  Program U2/Uturn in "Virtual Mode" and use the I/O MMU.

**

**  (c) Copyright 2000 Grant Grundler

**  (c) Copyright 2000 Ryan Bradetich

**  (c) Copyright 2000 Hewlett-Packard Company

**

** This program is free software; you can redistribute it and/or modify

** it under the terms of the GNU General Public License as published by

** the Free Software Foundation; either version 2 of the License, or

** (at your option) any later version.

**

**

**  "Real Mode" operation refers to U2/Uturn chip operation.

**  U2/Uturn were designed to perform coherency checks w/o using

**  the I/O MMU - basically what x86 does.

**

**  Philipp Rumpf has a "Real Mode" driver for PCX-W machines at:

**      CVSROOT=:pserver:anonymous@198.186.203.37:/cvsroot/linux-parisc

**      cvs -z3 co linux/arch/parisc/kernel/dma-rm.c

**

**  I've rewritten his code to work under TPG's tree. See ccio-rm-dma.c.

**

**  Drawbacks of using Real Mode are:

**  o outbound DMA is slower - U2 won't prefetch data (GSC+ XQL signal).

**      o Inbound DMA less efficient - U2 can't use DMA_FAST attribute.

**  o Ability to do scatter/gather in HW is lost.

**  o Doesn't work under PCX-U/U+ machines since they didn't follow

**        the coherency design originally worked out. Only PCX-W does.

*/

​

#include <linux/types.h>

#include <linux/kernel.h>

#include <linux/init.h>

#include <linux/mm.h>

#include <linux/spinlock.h>

#include <linux/slab.h>

#include <linux/string.h>

#include <linux/pci.h>

#include <linux/reboot.h>

#include <linux/proc_fs.h>

#include <linux/seq_file.h>

#include <linux/scatterlist.h>

#include <linux/iommu-helper.h>

#include <linux/export.h>

​

#include <asm/byteorder.h>

#include <asm/cache.h>      /* for L1_CACHE_BYTES */

#include <linux/uaccess.h>

#include <asm/page.h>

#include <asm/dma.h>

#include <asm/io.h>

#include <asm/hardware.h>       /* for register_module() */

#include <asm/parisc-device.h>

​

#include "iommu.h"

​

/* 

** Choose "ccio" since that's what HP-UX calls it.

** Make it easier for folks to migrate from one to the other :^)

*/