From 0db2e5d18f76a66ca945447d9f610bed0a94ca5a Mon Sep 17 00:00:00 2001 From: Robin Murphy Date: Thu, 1 Oct 2015 20:13:58 +0100 Subject: 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: Robin Murphy Signed-off-by: Joerg Roedel --- include/linux/dma-iommu.h | 85 +++++++++++++++++++++++++++++++++++++++++++++++ include/linux/iommu.h | 1 + 2 files changed, 86 insertions(+) create mode 100644 include/linux/dma-iommu.h (limited to 'include/linux') diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h new file mode 100644 index 000000000000..fc481037478a --- /dev/null +++ b/include/linux/dma-iommu.h @@ -0,0 +1,85 @@ +/* + * 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 . + */ +#ifndef __DMA_IOMMU_H +#define __DMA_IOMMU_H + +#ifdef __KERNEL__ +#include + +#ifdef CONFIG_IOMMU_DMA +#include + +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 */ diff --git a/include/linux/iommu.h b/include/linux/iommu.h index f9c1b6d0f2e4..f174506a5343 100644 --- a/include/linux/iommu.h +++ b/include/linux/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 { -- cgit v1.2.3