1 /*
2 * Copyright (C) 2014-2015 ARM Ltd.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License
14 * along with this program. If not, see <http://www.gnu.org/licenses/>.
15 */
16 #ifndef __DMA_IOMMU_H
17 #define __DMA_IOMMU_H
18
19 #ifdef __KERNEL__
20 #include <asm/errno.h>
21
22 #ifdef CONFIG_IOMMU_DMA
23 #include <linux/iommu.h>
24
25 int iommu_dma_init(void);
26
27 /* Domain management interface for IOMMU drivers */
28 int iommu_get_dma_cookie(struct iommu_domain *domain);
29 void iommu_put_dma_cookie(struct iommu_domain *domain);
30
31 /* Setup call for arch DMA mapping code */
32 int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base, u64 size);
33
34 /* General helpers for DMA-API <-> IOMMU-API interaction */
35 int dma_direction_to_prot(enum dma_data_direction dir, bool coherent);
36
37 /*
38 * These implement the bulk of the relevant DMA mapping callbacks, but require
39 * the arch code to take care of attributes and cache maintenance
40 */
41 struct page **iommu_dma_alloc(struct device *dev, size_t size,
42 gfp_t gfp, int prot, dma_addr_t *handle,
43 void (*flush_page)(struct device *, const void *, phys_addr_t));
44 void iommu_dma_free(struct device *dev, struct page **pages, size_t size,
45 dma_addr_t *handle);
46
47 int iommu_dma_mmap(struct page **pages, size_t size, struct vm_area_struct *vma);
48
49 dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page,
50 unsigned long offset, size_t size, int prot);
51 int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg,
52 int nents, int prot);
53
54 /*
55 * Arch code with no special attribute handling may use these
56 * directly as DMA mapping callbacks for simplicity
57 */
58 void iommu_dma_unmap_page(struct device *dev, dma_addr_t handle, size_t size,
59 enum dma_data_direction dir, struct dma_attrs *attrs);
60 void iommu_dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
61 enum dma_data_direction dir, struct dma_attrs *attrs);
62 int iommu_dma_supported(struct device *dev, u64 mask);
63 int iommu_dma_mapping_error(struct device *dev, dma_addr_t dma_addr);
64
65 #else
66
67 struct iommu_domain;
68
iommu_dma_init(void)69 static inline int iommu_dma_init(void)
70 {
71 return 0;
72 }
73
iommu_get_dma_cookie(struct iommu_domain * domain)74 static inline int iommu_get_dma_cookie(struct iommu_domain *domain)
75 {
76 return -ENODEV;
77 }
78
iommu_put_dma_cookie(struct iommu_domain * domain)79 static inline void iommu_put_dma_cookie(struct iommu_domain *domain)
80 {
81 }
82
83 #endif /* CONFIG_IOMMU_DMA */
84 #endif /* __KERNEL__ */
85 #endif /* __DMA_IOMMU_H */
86