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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
12struct ib_umem_odp {
13 struct ib_umem umem;
14 struct mmu_interval_notifier notifier;
15 struct pid *tgid;
16
17 /*
18 * An array of the pages included in the on-demand paging umem.
19 * Indices of pages that are currently not mapped into the device will
20 * contain NULL.
21 */
22 struct page **page_list;
23 /*
24 * An array of the same size as page_list, with DMA addresses mapped
25 * for pages the pages in page_list. The lower two bits designate
26 * access permissions. See ODP_READ_ALLOWED_BIT and
27 * ODP_WRITE_ALLOWED_BIT.
28 */
29 dma_addr_t *dma_list;
30 /*
31 * The umem_mutex protects the page_list and dma_list fields of an ODP
32 * umem, allowing only a single thread to map/unmap pages. The mutex
33 * also protects access to the mmu notifier counters.
34 */
35 struct mutex umem_mutex;
36 void *private; /* for the HW driver to use. */
37
38 int npages;
39
40 /*
41 * An implicit odp umem cannot be DMA mapped, has 0 length, and serves
42 * only as an anchor for the driver to hold onto the per_mm. FIXME:
43 * This should be removed and drivers should work with the per_mm
44 * directly.
45 */
46 bool is_implicit_odp;
47
48 unsigned int page_shift;
49};
50
51static inline struct ib_umem_odp *to_ib_umem_odp(struct ib_umem *umem)
52{
53 return container_of(umem, struct ib_umem_odp, umem);
54}
55
56/* Returns the first page of an ODP umem. */
57static inline unsigned long ib_umem_start(struct ib_umem_odp *umem_odp)
58{
59 return umem_odp->notifier.interval_tree.start;
60}
61
62/* Returns the address of the page after the last one of an ODP umem. */
63static inline unsigned long ib_umem_end(struct ib_umem_odp *umem_odp)
64{
65 return umem_odp->notifier.interval_tree.last + 1;
66}
67
68static inline size_t ib_umem_odp_num_pages(struct ib_umem_odp *umem_odp)
69{
70 return (ib_umem_end(umem_odp) - ib_umem_start(umem_odp)) >>
71 umem_odp->page_shift;
72}
73
74/*
75 * The lower 2 bits of the DMA address signal the R/W permissions for
76 * the entry. To upgrade the permissions, provide the appropriate
77 * bitmask to the map_dma_pages function.
78 *
79 * Be aware that upgrading a mapped address might result in change of
80 * the DMA address for the page.
81 */
82#define ODP_READ_ALLOWED_BIT (1<<0ULL)
83#define ODP_WRITE_ALLOWED_BIT (1<<1ULL)
84
85#define ODP_DMA_ADDR_MASK (~(ODP_READ_ALLOWED_BIT | ODP_WRITE_ALLOWED_BIT))
86
87#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
88
89struct ib_umem_odp *
90ib_umem_odp_get(struct ib_device *device, unsigned long addr, size_t size,
91 int access, const struct mmu_interval_notifier_ops *ops);
92struct ib_umem_odp *ib_umem_odp_alloc_implicit(struct ib_device *device,
93 int access);
94struct ib_umem_odp *
95ib_umem_odp_alloc_child(struct ib_umem_odp *root_umem, unsigned long addr,
96 size_t size,
97 const struct mmu_interval_notifier_ops *ops);
98void ib_umem_odp_release(struct ib_umem_odp *umem_odp);
99
100int ib_umem_odp_map_dma_pages(struct ib_umem_odp *umem_odp, u64 start_offset,
101 u64 bcnt, u64 access_mask,
102 unsigned long current_seq);
103
104void ib_umem_odp_unmap_dma_pages(struct ib_umem_odp *umem_odp, u64 start_offset,
105 u64 bound);
106
107#else /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */
108
109static inline struct ib_umem_odp *
110ib_umem_odp_get(struct ib_device *device, unsigned long addr, size_t size,
111 int access, const struct mmu_interval_notifier_ops *ops)
112{
113 return ERR_PTR(-EINVAL);
114}
115
116static inline void ib_umem_odp_release(struct ib_umem_odp *umem_odp) {}
117
118#endif /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */
119
120#endif /* IB_UMEM_ODP_H */