Commit 0db2e5d1 authored by Robin Murphy's avatar Robin Murphy Committed by Joerg Roedel

iommu: Implement common IOMMU ops for DMA mapping

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: default avatarRobin Murphy <>
Signed-off-by: default avatarJoerg Roedel <>
parent 25cb62b7
......@@ -49,6 +49,13 @@ config OF_IOMMU
def_bool y
depends on OF && IOMMU_API
# IOMMU-agnostic DMA-mapping layer
config IOMMU_DMA
select IOMMU_API
config FSL_PAMU
bool "Freescale IOMMU support"
depends on PPC32
obj-$(CONFIG_IOMMU_API) += iommu.o
obj-$(CONFIG_IOMMU_API) += iommu-traces.o
obj-$(CONFIG_IOMMU_API) += iommu-sysfs.o
obj-$(CONFIG_IOMMU_DMA) += dma-iommu.o
obj-$(CONFIG_IOMMU_IO_PGTABLE) += io-pgtable.o
obj-$(CONFIG_IOMMU_IO_PGTABLE_LPAE) += io-pgtable-arm.o
obj-$(CONFIG_IOMMU_IOVA) += iova.o
This diff is collapsed.
* 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
* 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 <>.
#ifndef __DMA_IOMMU_H
#define __DMA_IOMMU_H
#ifdef __KERNEL__
#include <asm/errno.h>
#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);
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 */
......@@ -81,6 +81,7 @@ struct iommu_domain {
iommu_fault_handler_t handler;
void *handler_token;
struct iommu_domain_geometry geometry;
void *iova_cookie;
enum iommu_cap {
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