2 * Copyright (c) 2014 Mellanox Technologies. All rights reserved.
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6 * General Public License (GPL) Version 2, available from the file
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8 * OpenIB.org BSD license below:
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11 * without modification, are permitted provided that the following
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15 * copyright notice, this list of conditions and the following
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23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
36 #include <rdma/ib_umem.h>
37 #include <rdma/ib_verbs.h>
38 #include <linux/interval_tree.h>
40 struct umem_odp_node {
47 struct ib_ucontext_per_mm *per_mm;
50 * An array of the pages included in the on-demand paging umem.
51 * Indices of pages that are currently not mapped into the device will
54 struct page **page_list;
56 * An array of the same size as page_list, with DMA addresses mapped
57 * for pages the pages in page_list. The lower two bits designate
58 * access permissions. See ODP_READ_ALLOWED_BIT and
59 * ODP_WRITE_ALLOWED_BIT.
63 * The umem_mutex protects the page_list and dma_list fields of an ODP
64 * umem, allowing only a single thread to map/unmap pages. The mutex
65 * also protects access to the mmu notifier counters.
67 struct mutex umem_mutex;
68 void *private; /* for the HW driver to use. */
74 struct umem_odp_node interval_tree;
76 struct completion notifier_completion;
78 struct work_struct work;
81 static inline struct ib_umem_odp *to_ib_umem_odp(struct ib_umem *umem)
83 return container_of(umem, struct ib_umem_odp, umem);
87 * The lower 2 bits of the DMA address signal the R/W permissions for
88 * the entry. To upgrade the permissions, provide the appropriate
89 * bitmask to the map_dma_pages function.
91 * Be aware that upgrading a mapped address might result in change of
92 * the DMA address for the page.
94 #define ODP_READ_ALLOWED_BIT (1<<0ULL)
95 #define ODP_WRITE_ALLOWED_BIT (1<<1ULL)
97 #define ODP_DMA_ADDR_MASK (~(ODP_READ_ALLOWED_BIT | ODP_WRITE_ALLOWED_BIT))
99 #ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
101 struct ib_ucontext_per_mm {
102 struct ib_ucontext *context;
103 struct mm_struct *mm;
107 struct rb_root_cached umem_tree;
108 /* Protects umem_tree */
109 struct rw_semaphore umem_rwsem;
111 struct mmu_notifier mn;
112 unsigned int odp_mrs_count;
114 struct list_head ucontext_list;
118 int ib_umem_odp_get(struct ib_umem_odp *umem_odp, int access);
119 struct ib_umem_odp *ib_alloc_odp_umem(struct ib_umem_odp *root_umem,
120 unsigned long addr, size_t size);
121 void ib_umem_odp_release(struct ib_umem_odp *umem_odp);
123 int ib_umem_odp_map_dma_pages(struct ib_umem_odp *umem_odp, u64 start_offset,
124 u64 bcnt, u64 access_mask,
125 unsigned long current_seq);
127 void ib_umem_odp_unmap_dma_pages(struct ib_umem_odp *umem_odp, u64 start_offset,
130 typedef int (*umem_call_back)(struct ib_umem_odp *item, u64 start, u64 end,
133 * Call the callback on each ib_umem in the range. Returns the logical or of
134 * the return values of the functions called.
136 int rbt_ib_umem_for_each_in_range(struct rb_root_cached *root,
139 bool blockable, void *cookie);
142 * Find first region intersecting with address range.
143 * Return NULL if not found
145 struct ib_umem_odp *rbt_ib_umem_lookup(struct rb_root_cached *root,
146 u64 addr, u64 length);
148 static inline int ib_umem_mmu_notifier_retry(struct ib_umem_odp *umem_odp,
149 unsigned long mmu_seq)
152 * This code is strongly based on the KVM code from
153 * mmu_notifier_retry. Should be called with
154 * the relevant locks taken (umem_odp->umem_mutex
155 * and the ucontext umem_mutex semaphore locked for read).
158 if (unlikely(umem_odp->notifiers_count))
160 if (umem_odp->notifiers_seq != mmu_seq)
165 #else /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */
167 static inline int ib_umem_odp_get(struct ib_umem_odp *umem_odp, int access)
172 static inline void ib_umem_odp_release(struct ib_umem_odp *umem_odp) {}
174 #endif /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */
176 #endif /* IB_UMEM_ODP_H */