blob: 44dabb1809f22b8dba8a5301ef8e22d2d5c427da [file] [log] [blame]
/* Copyright (c) 2015-2017, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 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.
*/
#ifndef _LINUX_MSM_DMA_IOMMU_MAPPING_H
#define _LINUX_MSM_DMA_IOMMU_MAPPING_H
#include <linux/device.h>
#include <linux/dma-buf.h>
#include <linux/scatterlist.h>
#include <linux/dma-mapping.h>
#ifdef CONFIG_QCOM_LAZY_MAPPING
/*
* This function is not taking a reference to the dma_buf here. It is expected
* that clients hold reference to the dma_buf until they are done with mapping
* and unmapping.
*/
int msm_dma_map_sg_attrs(struct device *dev, struct scatterlist *sg, int nents,
enum dma_data_direction dir, struct dma_buf *dma_buf,
unsigned long attrs);
/*
* This function takes an extra reference to the dma_buf.
* What this means is that calling msm_dma_unmap_sg will not result in buffer's
* iommu mapping being removed, which means that subsequent calls to lazy map
* will simply re-use the existing iommu mapping.
* The iommu unmapping of the buffer will occur when the ION buffer is
* destroyed.
* Using lazy mapping can provide a performance benefit because subsequent
* mappings are faster.
*
* The limitation of using this API are that all subsequent iommu mappings
* must be the same as the original mapping, ie they must map the same part of
* the buffer with the same dma data direction. Also there can't be multiple
* mappings of different parts of the buffer.
*/
static inline int msm_dma_map_sg_lazy(struct device *dev,
struct scatterlist *sg, int nents,
enum dma_data_direction dir,
struct dma_buf *dma_buf)
{
return msm_dma_map_sg_attrs(dev, sg, nents, dir, dma_buf, 0);
}
static inline int msm_dma_map_sg(struct device *dev, struct scatterlist *sg,
int nents, enum dma_data_direction dir,
struct dma_buf *dma_buf)
{
unsigned long attrs;
attrs = DMA_ATTR_NO_DELAYED_UNMAP;
return msm_dma_map_sg_attrs(dev, sg, nents, dir, dma_buf, attrs);
}
void msm_dma_unmap_sg(struct device *dev, struct scatterlist *sgl, int nents,
enum dma_data_direction dir, struct dma_buf *dma_buf);
int msm_dma_unmap_all_for_dev(struct device *dev);
/*
* Below is private function only to be called by framework (ION) and not by
* clients.
*/
void msm_dma_buf_freed(void *buffer);
#else /*CONFIG_QCOM_LAZY_MAPPING*/
static inline int msm_dma_map_sg_attrs(struct device *dev,
struct scatterlist *sg, int nents,
enum dma_data_direction dir, struct dma_buf *dma_buf,
unsigned long attrs)
{
return -EINVAL;
}
static inline int msm_dma_map_sg_lazy(struct device *dev,
struct scatterlist *sg, int nents,
enum dma_data_direction dir,
struct dma_buf *dma_buf)
{
return -EINVAL;
}
static inline int msm_dma_map_sg(struct device *dev, struct scatterlist *sg,
int nents, enum dma_data_direction dir,
struct dma_buf *dma_buf)
{
return -EINVAL;
}
static inline void msm_dma_unmap_sg(struct device *dev,
struct scatterlist *sgl, int nents,
enum dma_data_direction dir,
struct dma_buf *dma_buf)
{
}
static inline int msm_dma_unmap_all_for_dev(struct device *dev)
{
return 0;
}
static inline void msm_dma_buf_freed(void *buffer) {}
#endif /*CONFIG_QCOM_LAZY_MAPPING*/
#endif