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authorRobin Murphy <robin.murphy@arm.com>2015-10-01 22:13:58 +0300
committerJoerg Roedel <jroedel@suse.de>2015-10-15 17:41:04 +0300
commit0db2e5d18f76a66ca945447d9f610bed0a94ca5a (patch)
tree0c3d896165c2bd071eacdb06879082fcc0c32a12 /include/linux/dma-iommu.h
parent25cb62b76430a91cc6195f902e61c2cb84ade622 (diff)
downloadlinux-0db2e5d18f76a66ca945447d9f610bed0a94ca5a.tar.xz
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 <robin.murphy@arm.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'include/linux/dma-iommu.h')
-rw-r--r--include/linux/dma-iommu.h85
1 files changed, 85 insertions, 0 deletions
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 <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 */