/*
* Copyright (c) 2006 QLogic, Corporation. All rights reserved.
*
* This software is available to you under a choice of one of two
* licenses. You may choose to be licensed under the terms of the GNU
* General Public License (GPL) Version 2, available from the file
* COPYING in the main directory of this source tree, or the
* OpenIB.org BSD license below:
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer.
*
* - Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#include <linux/scatterlist.h>
#include <rdma/ib_verbs.h>
#include "ipath_verbs.h"
#define BAD_DMA_ADDRESS ((u64) 0)
/*
* The following functions implement driver specific replacements
* for the ib_dma_*() functions.
*
* These functions return kernel virtual addresses instead of
* device bus addresses since the driver uses the CPU to copy
* data instead of using hardware DMA.
*/
static int ipath_mapping_error(struct ib_device *dev, u64 dma_addr)
{
return dma_addr == BAD_DMA_ADDRESS;
}
static u64 ipath_dma_map_single(struct ib_device *dev,
void *cpu_addr, size_t size,
enum dma_data_direction direction)
{
BUG_ON(!valid_dma_direction(direction));
return (u64) cpu_addr;
}
static void ipath_dma_unmap_single(struct ib_device *dev,
u64 addr, size_t size,
enum dma_data_direction direction)
{
BUG_ON(!valid_dma_direction(direction));
}
static u64 ipath_dma_map_page(struct ib_device *dev,
struct page *page,
unsigned long offset,
size_t size,
enum dma_data_direction direction)
{
u64 addr;
BUG_ON(!valid_dma_direction(direction));
if (offset + size > PAGE_SIZE) {
addr = BAD_DMA_ADDRESS;
goto done;
}
addr = (u64) page_address(page);
if (addr)
addr += offset;
/* TODO: handle highmem pages */
done:
return addr;
}
static void ipath_dma_unmap_page(struct ib_device *dev,
u64 addr, size_t size,
enum dma_data_direction direction)
{
BUG_ON(!valid_dma_direction(direction));
}
static int ipath_map_sg(struct ib_device *dev, struct scatterlist *sgl,
int nents, enum dma_data_direction direction)
{
struct scatterlist *sg;
u64 addr;
int i;
int ret = nents;
BUG_ON(!valid_dma_direction(direction));
for_each_sg(sgl, sg, nents, i) {
addr = (u64) page_address(sg_page(sg));
/* TODO: handle highmem pages */
if (!addr) {
ret = 0;
break;
}
}
return ret;
}
static void ipath_unmap_sg(struct ib_device *dev,
struct scatterlist *sg, int nents,
enum dma_data_direction direction)
{
BUG_ON(!valid_dma_direction(direction));
}
static u64 ipath_sg_dma_address(struct ib_device *dev, struct scatterlist *sg)
{
u64 addr = (u64) page_address(sg_page(sg));
if (addr)
addr += sg->offset;
return addr;
}
static unsigned int ipath_sg_dma_len(struct ib_device *dev,
struct scatterlist *sg)
{
return sg->length;
}
static void ipath_sync_single_for_cpu(struct ib_device *dev,
u64 addr,
size_t size,
enum dma_data_direction dir)
{
}
static void ipath_sync_single_for_device(struct ib_device *dev,
u64 addr,
size_t size,
enum dma_data_direction dir)
{
}
static void *ipath_dma_alloc_coherent(struct ib_device *dev, size_t size,
u64 *dma_handle, gfp_t flag)
{
struct page *p;
void *addr = NULL;
p = alloc_pages(flag, get_order(size));
if (p)
addr = page_address(p);
if (dma_handle)
*dma_handle = (u64) addr;
return addr;
}
static void ipath_dma_free_coherent(struct ib_device *dev, size_t size,
void *cpu_addr, u64 dma_handle)
{
free_pages((unsigned long) cpu_addr, get_order(size));
}
struct ib_dma_mapping_ops ipath_dma_mapping_ops = {
ipath_mapping_error,
ipath_dma_map_single,
ipath_dma_unmap_single,
ipath_dma_map_page,
ipath_dma_unmap_page,
ipath_map_sg,
ipath_unmap_sg,
ipath_sg_dma_address,
ipath_sg_dma_len,
ipath_sync_single_for_cpu,
ipath_sync_single_for_device,
ipath_dma_alloc_coherent,
ipath_dma_free_coherent
};
