LXR linux/include/rdma/ib_umem

   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
  39struct 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
  78static 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. */
  84static 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. */
  90static inline unsigned long ib_umem_end(struct ib_umem_odp *umem_odp)
  91{
  92        return umem_odp->notifier.interval_tree.last + 1;
  93}
  94
  95static 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
 116struct ib_umem_odp *
 117ib_umem_odp_get(struct ib_device *device, unsigned long addr, size_t size,
 118                int access, const struct mmu_interval_notifier_ops *ops);
 119struct ib_umem_odp *ib_umem_odp_alloc_implicit(struct ib_device *device,
 120                                               int access);
 121struct ib_umem_odp *
 122ib_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);
 125void ib_umem_odp_release(struct ib_umem_odp *umem_odp);
 126
 127int 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
 131void 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
 136static inline struct ib_umem_odp *
 137ib_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
 143static 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 */
 148