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iommu: Implement common IOMMU ops for DMA mapping

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Taking inspiration from the existing arch/arm code, break out some
generic functions to interface the DMA-API to the IOMMU-API. This will
do the bulk of the heavy lifting for IOMMU-backed dma-mapping.

Since associating an IOVA allocator with an IOMMU domain is a fairly
common need, rather than introduce yet another private structure just to
do this for ourselves, extend the top-level struct iommu_domain with the
notion. A simple opaque cookie allows reuse by other IOMMU API users
with their various different incompatible allocator types.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Robin Murphy
2015-10-01 20:13:58 +01:00
committed by Joerg Roedel
parent 25cb62b764
commit 0db2e5d18f
5 changed files with 618 additions and 0 deletions
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85
include/linux/dma-iommu.h Normal file
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/*
* Copyright (C) 2014-2015 ARM Ltd.
*
* 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.
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __DMA_IOMMU_H
#define __DMA_IOMMU_H
#ifdef __KERNEL__
#include <asm/errno.h>
#ifdef CONFIG_IOMMU_DMA
#include <linux/iommu.h>
int iommu_dma_init(void);
/* Domain management interface for IOMMU drivers */
int iommu_get_dma_cookie(struct iommu_domain *domain);
void iommu_put_dma_cookie(struct iommu_domain *domain);
/* Setup call for arch DMA mapping code */
int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base, u64 size);
/* General helpers for DMA-API <-> IOMMU-API interaction */
int dma_direction_to_prot(enum dma_data_direction dir, bool coherent);
/*
* These implement the bulk of the relevant DMA mapping callbacks, but require
* the arch code to take care of attributes and cache maintenance
*/
struct page **iommu_dma_alloc(struct device *dev, size_t size,
gfp_t gfp, int prot, dma_addr_t *handle,
void (*flush_page)(struct device *, const void *, phys_addr_t));
void iommu_dma_free(struct device *dev, struct page **pages, size_t size,
dma_addr_t *handle);
int iommu_dma_mmap(struct page **pages, size_t size, struct vm_area_struct *vma);
dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size, int prot);
int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg,
int nents, int prot);
/*
* Arch code with no special attribute handling may use these
* directly as DMA mapping callbacks for simplicity
*/
void iommu_dma_unmap_page(struct device *dev, dma_addr_t handle, size_t size,
enum dma_data_direction dir, struct dma_attrs *attrs);
void iommu_dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
enum dma_data_direction dir, struct dma_attrs *attrs);
int iommu_dma_supported(struct device *dev, u64 mask);
int iommu_dma_mapping_error(struct device *dev, dma_addr_t dma_addr);
#else
struct iommu_domain;
static inline int iommu_dma_init(void)
{
return 0;
}
static inline int iommu_get_dma_cookie(struct iommu_domain *domain)
{
return -ENODEV;
}
static inline void iommu_put_dma_cookie(struct iommu_domain *domain)
{
}
#endif /* CONFIG_IOMMU_DMA */
#endif /* __KERNEL__ */
#endif /* __DMA_IOMMU_H */