dma.c
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/*
* Copyright (C) 2011 Texas Instruments Incorporated
* Author: Mark Salter <msalter@redhat.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/dma-mapping.h>
#include <linux/mm.h>
#include <linux/mm_types.h>
#include <linux/scatterlist.h>
#include <asm/cacheflush.h>
static void c6x_dma_sync(dma_addr_t handle, size_t size,
enum dma_data_direction dir)
{
unsigned long paddr = handle;
BUG_ON(!valid_dma_direction(dir));
switch (dir) {
case DMA_FROM_DEVICE:
L2_cache_block_invalidate(paddr, paddr + size);
break;
case DMA_TO_DEVICE:
L2_cache_block_writeback(paddr, paddr + size);
break;
case DMA_BIDIRECTIONAL:
L2_cache_block_writeback_invalidate(paddr, paddr + size);
break;
default:
break;
}
}
static dma_addr_t c6x_dma_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size, enum dma_data_direction dir,
unsigned long attrs)
{
dma_addr_t handle = virt_to_phys(page_address(page) + offset);
if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
c6x_dma_sync(handle, size, dir);
return handle;
}
static void c6x_dma_unmap_page(struct device *dev, dma_addr_t handle,
size_t size, enum dma_data_direction dir, unsigned long attrs)
{
if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
c6x_dma_sync(handle, size, dir);
}
static int c6x_dma_map_sg(struct device *dev, struct scatterlist *sglist,
int nents, enum dma_data_direction dir, unsigned long attrs)
{
struct scatterlist *sg;
int i;
for_each_sg(sglist, sg, nents, i) {
sg->dma_address = sg_phys(sg);
if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
c6x_dma_sync(sg->dma_address, sg->length, dir);
}
return nents;
}
static void c6x_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
int nents, enum dma_data_direction dir, unsigned long attrs)
{
struct scatterlist *sg;
int i;
if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
return;
for_each_sg(sglist, sg, nents, i)
c6x_dma_sync(sg_dma_address(sg), sg->length, dir);
}
static void c6x_dma_sync_single_for_cpu(struct device *dev, dma_addr_t handle,
size_t size, enum dma_data_direction dir)
{
c6x_dma_sync(handle, size, dir);
}
static void c6x_dma_sync_single_for_device(struct device *dev,
dma_addr_t handle, size_t size, enum dma_data_direction dir)
{
c6x_dma_sync(handle, size, dir);
}
static void c6x_dma_sync_sg_for_cpu(struct device *dev,
struct scatterlist *sglist, int nents,
enum dma_data_direction dir)
{
struct scatterlist *sg;
int i;
for_each_sg(sglist, sg, nents, i)
c6x_dma_sync_single_for_cpu(dev, sg_dma_address(sg),
sg->length, dir);
}
static void c6x_dma_sync_sg_for_device(struct device *dev,
struct scatterlist *sglist, int nents,
enum dma_data_direction dir)
{
struct scatterlist *sg;
int i;
for_each_sg(sglist, sg, nents, i)
c6x_dma_sync_single_for_device(dev, sg_dma_address(sg),
sg->length, dir);
}
const struct dma_map_ops c6x_dma_ops = {
.alloc = c6x_dma_alloc,
.free = c6x_dma_free,
.map_page = c6x_dma_map_page,
.unmap_page = c6x_dma_unmap_page,
.map_sg = c6x_dma_map_sg,
.unmap_sg = c6x_dma_unmap_sg,
.sync_single_for_device = c6x_dma_sync_single_for_device,
.sync_single_for_cpu = c6x_dma_sync_single_for_cpu,
.sync_sg_for_device = c6x_dma_sync_sg_for_device,
.sync_sg_for_cpu = c6x_dma_sync_sg_for_cpu,
};
EXPORT_SYMBOL(c6x_dma_ops);
/* Number of entries preallocated for DMA-API debugging */
#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
static int __init dma_init(void)
{
dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
return 0;
}
fs_initcall(dma_init);