1 /* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
2 /*
3 * Copyright (c) 2014 Mellanox Technologies. All rights reserved.
4 */
5
6 #ifndef IB_UMEM_ODP_H
7 #define IB_UMEM_ODP_H
8
9 #include <rdma/ib_umem.h>
10 #include <rdma/ib_verbs.h>
11
12 struct ib_umem_odp {
13 struct ib_umem umem;
14 struct mmu_interval_notifier notifier;
15 struct pid *tgid;
16
17 /* An array of the pfns included in the on-demand paging umem. */
18 unsigned long *pfn_list;
19
20 /*
21 * An array with DMA addresses mapped for pfns in pfn_list.
22 * The lower two bits designate access permissions.
23 * See ODP_READ_ALLOWED_BIT and ODP_WRITE_ALLOWED_BIT.
24 */
25 dma_addr_t *dma_list;
26 /*
27 * The umem_mutex protects the page_list and dma_list fields of an ODP
28 * umem, allowing only a single thread to map/unmap pages. The mutex
29 * also protects access to the mmu notifier counters.
30 */
31 struct mutex umem_mutex;
32 void *private; /* for the HW driver to use. */
33
34 int npages;
35
36 /*
37 * An implicit odp umem cannot be DMA mapped, has 0 length, and serves
38 * only as an anchor for the driver to hold onto the per_mm. FIXME:
39 * This should be removed and drivers should work with the per_mm
40 * directly.
41 */
42 bool is_implicit_odp;
43
44 unsigned int page_shift;
45 };
46
47 static inline struct ib_umem_odp *to_ib_umem_odp(struct ib_umem *umem)
48 {
49 return container_of(umem, struct ib_umem_odp, umem);
50 }
51
52 /* Returns the first page of an ODP umem. */
53 static inline unsigned long ib_umem_start(struct ib_umem_odp *umem_odp)
54 {
55 return umem_odp->notifier.interval_tree.start;
56 }
57
58 /* Returns the address of the page after the last one of an ODP umem. */
59 static inline unsigned long ib_umem_end(struct ib_umem_odp *umem_odp)
60 {
61 return umem_odp->notifier.interval_tree.last + 1;
62 }
63
64 static inline size_t ib_umem_odp_num_pages(struct ib_umem_odp *umem_odp)
65 {
66 return (ib_umem_end(umem_odp) - ib_umem_start(umem_odp)) >>
67 umem_odp->page_shift;
68 }
69
70 /*
71 * The lower 2 bits of the DMA address signal the R/W permissions for
72 * the entry. To upgrade the permissions, provide the appropriate
73 * bitmask to the map_dma_pages function.
74 *
75 * Be aware that upgrading a mapped address might result in change of
76 * the DMA address for the page.
77 */
78 #define ODP_READ_ALLOWED_BIT (1<<0ULL)
79 #define ODP_WRITE_ALLOWED_BIT (1<<1ULL)
80
81 #define ODP_DMA_ADDR_MASK (~(ODP_READ_ALLOWED_BIT | ODP_WRITE_ALLOWED_BIT))
82
83 #ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
84
85 struct ib_umem_odp *
86 ib_umem_odp_get(struct ib_device *device, unsigned long addr, size_t size,
87 int access, const struct mmu_interval_notifier_ops *ops);
88 struct ib_umem_odp *ib_umem_odp_alloc_implicit(struct ib_device *device,
89 int access);
90 struct ib_umem_odp *
91 ib_umem_odp_alloc_child(struct ib_umem_odp *root_umem, unsigned long addr,
92 size_t size,
93 const struct mmu_interval_notifier_ops *ops);
94 void ib_umem_odp_release(struct ib_umem_odp *umem_odp);
95
96 int ib_umem_odp_map_dma_and_lock(struct ib_umem_odp *umem_odp, u64 start_offset,
97 u64 bcnt, u64 access_mask, bool fault);
98
99 void ib_umem_odp_unmap_dma_pages(struct ib_umem_odp *umem_odp, u64 start_offset,
100 u64 bound);
101
102 #else /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */
103
104 static inline struct ib_umem_odp *
105 ib_umem_odp_get(struct ib_device *device, unsigned long addr, size_t size,
106 int access, const struct mmu_interval_notifier_ops *ops)
107 {
108 return ERR_PTR(-EINVAL);
109 }
110
111 static inline void ib_umem_odp_release(struct ib_umem_odp *umem_odp) {}
112
113 #endif /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */
114
115 #endif /* IB_UMEM_ODP_H */
116
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