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/*
* Copyright(c) 2016 Intel Corporation.
*
* This file is provided under a dual BSD/GPLv2 license. When using or
* redistributing this file, you may do so under either license.
*
* GPL LICENSE SUMMARY
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of version 2 of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* BSD LICENSE
*
* 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.
* - Neither the name of Intel Corporation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include <linux/types.h>
#include <linux/scatterlist.h>
#include <rdma/ib_verbs.h>
#include "dma.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 rvt_mapping_error(struct ib_device *dev, u64 dma_addr)
{
return dma_addr == BAD_DMA_ADDRESS;
}
static u64 rvt_dma_map_single(struct ib_device *dev, void *cpu_addr,
size_t size, enum dma_data_direction direction)
{
if (WARN_ON(!valid_dma_direction(direction)))
return BAD_DMA_ADDRESS;
return (u64)cpu_addr;
}
static void rvt_dma_unmap_single(struct ib_device *dev, u64 addr, size_t size,
enum dma_data_direction direction)
{
/* This is a stub, nothing to be done here */
}
static u64 rvt_dma_map_page(struct ib_device *dev, struct page *page,
unsigned long offset, size_t size,
enum dma_data_direction direction)
{
u64 addr;
if (WARN_ON(!valid_dma_direction(direction)))
return BAD_DMA_ADDRESS;
if (offset + size > PAGE_SIZE)
return BAD_DMA_ADDRESS;
addr = (u64)page_address(page);
if (addr)
addr += offset;
return addr;
}
static void rvt_dma_unmap_page(struct ib_device *dev, u64 addr, size_t size,
enum dma_data_direction direction)
{
/* This is a stub, nothing to be done here */
}
static int rvt_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;
if (WARN_ON(!valid_dma_direction(direction)))
return 0;
for_each_sg(sgl, sg, nents, i) {
addr = (u64)page_address(sg_page(sg));
if (!addr) {
ret = 0;
break;
}
sg->dma_address = addr + sg->offset;
#ifdef CONFIG_NEED_SG_DMA_LENGTH
sg->dma_length = sg->length;
#endif
}
return ret;
}
static void rvt_unmap_sg(struct ib_device *dev,
struct scatterlist *sg, int nents,
enum dma_data_direction direction)
{
/* This is a stub, nothing to be done here */
}
static void rvt_sync_single_for_cpu(struct ib_device *dev, u64 addr,
size_t size, enum dma_data_direction dir)
{
}
static void rvt_sync_single_for_device(struct ib_device *dev, u64 addr,
size_t size,
enum dma_data_direction dir)
{
}
static void *rvt_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 rvt_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 rvt_default_dma_mapping_ops = {
.mapping_error = rvt_mapping_error,
.map_single = rvt_dma_map_single,
.unmap_single = rvt_dma_unmap_single,
.map_page = rvt_dma_map_page,
.unmap_page = rvt_dma_unmap_page,
.map_sg = rvt_map_sg,
.unmap_sg = rvt_unmap_sg,
.sync_single_for_cpu = rvt_sync_single_for_cpu,
.sync_single_for_device = rvt_sync_single_for_device,
.alloc_coherent = rvt_dma_alloc_coherent,
.free_coherent = rvt_dma_free_coherent
};
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