LXR linux/include/rdma/ib_umem

   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        /* 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
  47static 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. */
  53static 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. */
  59static inline unsigned long ib_umem_end(struct ib_umem_odp *umem_odp)
  60{
  61        return umem_odp->notifier.interval_tree.last + 1;
  62}
  63
  64static 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
  85struct ib_umem_odp *
  86ib_umem_odp_get(struct ib_device *device, unsigned long addr, size_t size,
  87                int access, const struct mmu_interval_notifier_ops *ops);
  88struct ib_umem_odp *ib_umem_odp_alloc_implicit(struct ib_device *device,
  89                                               int access);
  90struct ib_umem_odp *
  91ib_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);
  94void ib_umem_odp_release(struct ib_umem_odp *umem_odp);
  95
  96int 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
  99void 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
 104static inline struct ib_umem_odp *
 105ib_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
 111static 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