xref: /openbmc/linux/include/drm/ttm/ttm_kmap_iter.h (revision 9a29f5fc)
1 /* SPDX-License-Identifier: MIT */
2 /*
3  * Copyright © 2021 Intel Corporation
4  */
5 #ifndef __TTM_KMAP_ITER_H__
6 #define __TTM_KMAP_ITER_H__
7 
8 #include <linux/types.h>
9 
10 struct ttm_kmap_iter;
11 struct iosys_map;
12 
13 /**
14  * struct ttm_kmap_iter_ops - Ops structure for a struct
15  * ttm_kmap_iter.
16  * @maps_tt: Whether the iterator maps TT memory directly, as opposed
17  * mapping a TT through an aperture. Both these modes have
18  * struct ttm_resource_manager::use_tt set, but the latter typically
19  * returns is_iomem == true from ttm_mem_io_reserve.
20  */
21 struct ttm_kmap_iter_ops {
22 	/**
23 	 * kmap_local() - Map a PAGE_SIZE part of the resource using
24 	 * kmap_local semantics.
25 	 * @res_iter: Pointer to the struct ttm_kmap_iter representing
26 	 * the resource.
27 	 * @dmap: The struct iosys_map holding the virtual address after
28 	 * the operation.
29 	 * @i: The location within the resource to map. PAGE_SIZE granularity.
30 	 */
31 	void (*map_local)(struct ttm_kmap_iter *res_iter,
32 			  struct iosys_map *dmap, pgoff_t i);
33 	/**
34 	 * unmap_local() - Unmap a PAGE_SIZE part of the resource previously
35 	 * mapped using kmap_local.
36 	 * @res_iter: Pointer to the struct ttm_kmap_iter representing
37 	 * the resource.
38 	 * @dmap: The struct iosys_map holding the virtual address after
39 	 * the operation.
40 	 */
41 	void (*unmap_local)(struct ttm_kmap_iter *res_iter,
42 			    struct iosys_map *dmap);
43 	bool maps_tt;
44 };
45 
46 /**
47  * struct ttm_kmap_iter - Iterator for kmap_local type operations on a
48  * resource.
49  * @ops: Pointer to the operations struct.
50  *
51  * This struct is intended to be embedded in a resource-specific specialization
52  * implementing operations for the resource.
53  *
54  * Nothing stops us from extending the operations to vmap, vmap_pfn etc,
55  * replacing some or parts of the ttm_bo_util. cpu-map functionality.
56  */
57 struct ttm_kmap_iter {
58 	const struct ttm_kmap_iter_ops *ops;
59 };
60 
61 #endif /* __TTM_KMAP_ITER_H__ */
62