include/rdma/ib_umem_odp.h

   1 /*
   2  * Copyright (c) 2014 Mellanox Technologies. All rights reserved.
   3  *
   4  * This software is available to you under a choice of one of two
   5  * licenses.  You may choose to be licensed under the terms of the GNU
   6  * General Public License (GPL) Version 2, available from the file
   7  * COPYING in the main directory of this source tree, or the
   8  * OpenIB.org BSD license below:
   9  *
  10  *     Redistribution and use in source and binary forms, with or
  11  *     without modification, are permitted provided that the following
  12  *     conditions are met:
  13  *
  14  *      - Redistributions of source code must retain the above
  15  *        copyright notice, this list of conditions and the following
  16  *        disclaimer.
  17  *
  18  *      - Redistributions in binary form must reproduce the above
  19  *        copyright notice, this list of conditions and the following
  20  *        disclaimer in the documentation and/or other materials
  21  *        provided with the distribution.
  22  *
  23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  30  * SOFTWARE.
  31  */
  32
  33 #ifndef IB_UMEM_ODP_H
  34 #define IB_UMEM_ODP_H
  35
  36 #include <rdma/ib_umem.h>
  37 #include <rdma/ib_verbs.h>
  38
  39 struct ib_umem_odp {
  40         struct ib_umem umem;
  41         struct mmu_interval_notifier notifier;
  42         struct pid *tgid;
  43
  44         /*
  45          * An array of the pages included in the on-demand paging umem.
  46          * Indices of pages that are currently not mapped into the device will
  47          * contain NULL.
  48          */
  49         struct page             **page_list;
  50         /*
  51          * An array of the same size as page_list, with DMA addresses mapped
  52          * for pages the pages in page_list. The lower two bits designate
  53          * access permissions. See ODP_READ_ALLOWED_BIT and
  54          * ODP_WRITE_ALLOWED_BIT.
  55          */
  56         dma_addr_t              *dma_list;
  57         /*
  58          * The umem_mutex protects the page_list and dma_list fields of an ODP
  59          * umem, allowing only a single thread to map/unmap pages. The mutex
  60          * also protects access to the mmu notifier counters.
  61          */
  62         struct mutex            umem_mutex;
  63         void                    *private; /* for the HW driver to use. */
  64
  65         int npages;
  66
  67         /*
  68          * An implicit odp umem cannot be DMA mapped, has 0 length, and serves
  69          * only as an anchor for the driver to hold onto the per_mm. FIXME:
  70          * This should be removed and drivers should work with the per_mm
  71          * directly.
  72          */
  73         bool is_implicit_odp;
  74
  75         unsigned int            page_shift;
  76 };
  77
  78 static inline struct ib_umem_odp *to_ib_umem_odp(struct ib_umem *umem)
  79 {
  80         return container_of(umem, struct ib_umem_odp, umem);
  81 }
  82
  83 /* Returns the first page of an ODP umem. */
  84 static inline unsigned long ib_umem_start(struct ib_umem_odp *umem_odp)
  85 {
  86         return umem_odp->notifier.interval_tree.start;
  87 }
  88
  89 /* Returns the address of the page after the last one of an ODP umem. */
  90 static inline unsigned long ib_umem_end(struct ib_umem_odp *umem_odp)
  91 {
  92         return umem_odp->notifier.interval_tree.last + 1;
  93 }
  94
  95 static inline size_t ib_umem_odp_num_pages(struct ib_umem_odp *umem_odp)
  96 {
  97         return (ib_umem_end(umem_odp) - ib_umem_start(umem_odp)) >>
  98                umem_odp->page_shift;
  99 }
 100
 101 /*
 102  * The lower 2 bits of the DMA address signal the R/W permissions for
 103  * the entry. To upgrade the permissions, provide the appropriate
 104  * bitmask to the map_dma_pages function.
 105  *
 106  * Be aware that upgrading a mapped address might result in change of
 107  * the DMA address for the page.
 108  */
 109 #define ODP_READ_ALLOWED_BIT  (1<<0ULL)
 110 #define ODP_WRITE_ALLOWED_BIT (1<<1ULL)
 111
 112 #define ODP_DMA_ADDR_MASK (~(ODP_READ_ALLOWED_BIT | ODP_WRITE_ALLOWED_BIT))
 113
 114 #ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
 115
 116 struct ib_umem_odp *
 117 ib_umem_odp_get(struct ib_device *device, unsigned long addr, size_t size,
 118                 int access, const struct mmu_interval_notifier_ops *ops);
 119 struct ib_umem_odp *ib_umem_odp_alloc_implicit(struct ib_device *device,
 120                                                int access);
 121 struct ib_umem_odp *
 122 ib_umem_odp_alloc_child(struct ib_umem_odp *root_umem, unsigned long addr,
 123                         size_t size,
 124                         const struct mmu_interval_notifier_ops *ops);
 125 void ib_umem_odp_release(struct ib_umem_odp *umem_odp);
 126
 127 int ib_umem_odp_map_dma_pages(struct ib_umem_odp *umem_odp, u64 start_offset,
 128                               u64 bcnt, u64 access_mask,
 129                               unsigned long current_seq);
 130
 131 void ib_umem_odp_unmap_dma_pages(struct ib_umem_odp *umem_odp, u64 start_offset,
 132                                  u64 bound);
 133
 134 #else /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */
 135
 136 static inline struct ib_umem_odp *
 137 ib_umem_odp_get(struct ib_device *device, unsigned long addr, size_t size,
 138                 int access, const struct mmu_interval_notifier_ops *ops)
 139 {
 140         return ERR_PTR(-EINVAL);
 141 }
 142
 143 static inline void ib_umem_odp_release(struct ib_umem_odp *umem_odp) {}
 144
 145 #endif /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */
 146
 147 #endif /* IB_UMEM_ODP_H */