include/rdma/ib_umem_odp.h

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