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 <linux/types.h>
21 #include <asm/errno.h>
22
23 #ifdef CONFIG_IOMMU_DMA
24 #include <linux/iommu.h>
25
26 int iommu_dma_init(void);
27
28 /* Domain management interface for IOMMU drivers */
29 int iommu_get_dma_cookie(struct iommu_domain *domain);
30 void iommu_put_dma_cookie(struct iommu_domain *domain);
31
32 /* Setup call for arch DMA mapping code */
33 int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base, u64 size);
34
35 /* General helpers for DMA-API <-> IOMMU-API interaction */
36 int dma_direction_to_prot(enum dma_data_direction dir, bool coherent);
37
38 /*
39 * These implement the bulk of the relevant DMA mapping callbacks, but require
40 * the arch code to take care of attributes and cache maintenance
41 */
42 struct page **iommu_dma_alloc(struct device *dev, size_t size,
43 gfp_t gfp, int prot, dma_addr_t *handle,
44 void (*flush_page)(struct device *, const void *, phys_addr_t));
45 void iommu_dma_free(struct device *dev, struct page **pages, size_t size,
46 dma_addr_t *handle);
47
48 int iommu_dma_mmap(struct page **pages, size_t size, struct vm_area_struct *vma);
49
50 dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page,
51 unsigned long offset, size_t size, int prot);
52 int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg,
53 int nents, int prot);
54
55 /*
56 * Arch code with no special attribute handling may use these
57 * directly as DMA mapping callbacks for simplicity
58 */
59 void iommu_dma_unmap_page(struct device *dev, dma_addr_t handle, size_t size,
60 enum dma_data_direction dir, struct dma_attrs *attrs);
61 void iommu_dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
62 enum dma_data_direction dir, struct dma_attrs *attrs);
63 int iommu_dma_supported(struct device *dev, u64 mask);
64 int iommu_dma_mapping_error(struct device *dev, dma_addr_t dma_addr);
65
66 #else
67
68 struct iommu_domain;
69
iommu_dma_init(void)70 static inline int iommu_dma_init(void)
71 {
72 return 0;
73 }
74
iommu_get_dma_cookie(struct iommu_domain * domain)75 static inline int iommu_get_dma_cookie(struct iommu_domain *domain)
76 {
77 return -ENODEV;
78 }
79
iommu_put_dma_cookie(struct iommu_domain * domain)80 static inline void iommu_put_dma_cookie(struct iommu_domain *domain)
81 {
82 }
83
84 #endif /* CONFIG_IOMMU_DMA */
85 #endif /* __KERNEL__ */
86 #endif /* __DMA_IOMMU_H */
87