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/*
* Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch>
* Copyright (C) 2009 Wind River Systems Inc
* Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com
*
* Based on DMA code from MIPS.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/export.h>
#include <linux/string.h>
#include <linux/scatterlist.h>
#include <linux/dma-mapping.h>
#include <linux/io.h>
#include <linux/cache.h>
#include <asm/cacheflush.h>
static inline void __dma_sync_for_device(void *vaddr, size_t size,
enum dma_data_direction direction)
{
switch (direction) {
case DMA_FROM_DEVICE:
invalidate_dcache_range((unsigned long)vaddr,
(unsigned long)(vaddr + size));
break;
case DMA_TO_DEVICE:
/*
* We just need to flush the caches here , but Nios2 flush
* instruction will do both writeback and invalidate.
*/
case DMA_BIDIRECTIONAL: /* flush and invalidate */
flush_dcache_range((unsigned long)vaddr,
(unsigned long)(vaddr + size));
break;
default:
BUG();
}
}
static inline void __dma_sync_for_cpu(void *vaddr, size_t size,
enum dma_data_direction direction)
{
switch (direction) {
case DMA_BIDIRECTIONAL:
case DMA_FROM_DEVICE:
invalidate_dcache_range((unsigned long)vaddr,
(unsigned long)(vaddr + size));
break;
case DMA_TO_DEVICE:
break;
default:
BUG();
}
}
static void *nios2_dma_alloc(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
{
void *ret;
/* ignore region specifiers */
gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
/* optimized page clearing */
gfp |= __GFP_ZERO;
if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff))
gfp |= GFP_DMA;
ret = (void *) __get_free_pages(gfp, get_order(size));
if (ret != NULL) {
*dma_handle = virt_to_phys(ret);
flush_dcache_range((unsigned long) ret,
(unsigned long) ret + size);
ret = UNCAC_ADDR(ret);
}
return ret;
}
static void nios2_dma_free(struct device *dev, size_t size, void *vaddr,
dma_addr_t dma_handle, unsigned long attrs)
{
unsigned long addr = (unsigned long) CAC_ADDR((unsigned long) vaddr);
free_pages(addr, get_order(size));
}
static int nios2_dma_map_sg(struct device *dev, struct scatterlist *sg,
int nents, enum dma_data_direction direction,
unsigned long attrs)
{
int i;
for_each_sg(sg, sg, nents, i) {
void *addr = sg_virt(sg);
if (!addr)
continue;
sg->dma_address = sg_phys(sg);
if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
continue;
__dma_sync_for_device(addr, sg->length, direction);
}
return nents;
}
static dma_addr_t nios2_dma_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size,
enum dma_data_direction direction,
unsigned long attrs)
{
void *addr = page_address(page) + offset;
if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
__dma_sync_for_device(addr, size, direction);
return page_to_phys(page) + offset;
}
static void nios2_dma_unmap_page(struct device *dev, dma_addr_t dma_address,
size_t size, enum dma_data_direction direction,
unsigned long attrs)
{
if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
__dma_sync_for_cpu(phys_to_virt(dma_address), size, direction);
}
static void nios2_dma_unmap_sg(struct device *dev, struct scatterlist *sg,
int nhwentries, enum dma_data_direction direction,
unsigned long attrs)
{
void *addr;
int i;
if (direction == DMA_TO_DEVICE)
return;
if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
return;
for_each_sg(sg, sg, nhwentries, i) {
addr = sg_virt(sg);
if (addr)
__dma_sync_for_cpu(addr, sg->length, direction);
}
}
static void nios2_dma_sync_single_for_cpu(struct device *dev,
dma_addr_t dma_handle, size_t size,
enum dma_data_direction direction)
{
__dma_sync_for_cpu(phys_to_virt(dma_handle), size, direction);
}
static void nios2_dma_sync_single_for_device(struct device *dev,
dma_addr_t dma_handle, size_t size,
enum dma_data_direction direction)
{
__dma_sync_for_device(phys_to_virt(dma_handle), size, direction);
}
static void nios2_dma_sync_sg_for_cpu(struct device *dev,
struct scatterlist *sg, int nelems,
enum dma_data_direction direction)
{
int i;
/* Make sure that gcc doesn't leave the empty loop body. */
for_each_sg(sg, sg, nelems, i)
__dma_sync_for_cpu(sg_virt(sg), sg->length, direction);
}
static void nios2_dma_sync_sg_for_device(struct device *dev,
struct scatterlist *sg, int nelems,
enum dma_data_direction direction)
{
int i;
/* Make sure that gcc doesn't leave the empty loop body. */
for_each_sg(sg, sg, nelems, i)
__dma_sync_for_device(sg_virt(sg), sg->length, direction);
}
const struct dma_map_ops nios2_dma_ops = {
.alloc = nios2_dma_alloc,
.free = nios2_dma_free,
.map_page = nios2_dma_map_page,
.unmap_page = nios2_dma_unmap_page,
.map_sg = nios2_dma_map_sg,
.unmap_sg = nios2_dma_unmap_sg,
.sync_single_for_device = nios2_dma_sync_single_for_device,
.sync_single_for_cpu = nios2_dma_sync_single_for_cpu,
.sync_sg_for_cpu = nios2_dma_sync_sg_for_cpu,
.sync_sg_for_device = nios2_dma_sync_sg_for_device,
};
EXPORT_SYMBOL(nios2_dma_ops);
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