include/rdma/ib_umem.h

   1 /* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
   2 /*
   3  * Copyright (c) 2007 Cisco Systems.  All rights reserved.
   4  * Copyright (c) 2020 Intel Corporation.  All rights reserved.
   5  */
   6
   7 #ifndef IB_UMEM_H
   8 #define IB_UMEM_H
   9
  10 #include <linux/list.h>
  11 #include <linux/scatterlist.h>
  12 #include <linux/workqueue.h>
  13 #include <rdma/ib_verbs.h>
  14
  15 struct ib_ucontext;
  16 struct ib_umem_odp;
  17 struct dma_buf_attach_ops;
  18
  19 struct ib_umem {
  20         struct ib_device       *ibdev;
  21         struct mm_struct       *owning_mm;
  22         u64 iova;
  23         size_t                  length;
  24         unsigned long           address;
  25         u32 writable : 1;
  26         u32 is_odp : 1;
  27         u32 is_dmabuf : 1;
  28         struct work_struct      work;
  29         struct sg_append_table sgt_append;
  30 };
  31
  32 struct ib_umem_dmabuf {
  33         struct ib_umem umem;
  34         struct dma_buf_attachment *attach;
  35         struct sg_table *sgt;
  36         struct scatterlist *first_sg;
  37         struct scatterlist *last_sg;
  38         unsigned long first_sg_offset;
  39         unsigned long last_sg_trim;
  40         void *private;
  41 };
  42
  43 static inline struct ib_umem_dmabuf *to_ib_umem_dmabuf(struct ib_umem *umem)
  44 {
  45         return container_of(umem, struct ib_umem_dmabuf, umem);
  46 }
  47
  48 /* Returns the offset of the umem start relative to the first page. */
  49 static inline int ib_umem_offset(struct ib_umem *umem)
  50 {
  51         return umem->address & ~PAGE_MASK;
  52 }
  53
  54 static inline unsigned long ib_umem_dma_offset(struct ib_umem *umem,
  55                                                unsigned long pgsz)
  56 {
  57         return (sg_dma_address(umem->sgt_append.sgt.sgl) + ib_umem_offset(umem)) &
  58                (pgsz - 1);
  59 }
  60
  61 static inline size_t ib_umem_num_dma_blocks(struct ib_umem *umem,
  62                                             unsigned long pgsz)
  63 {
  64         return (size_t)((ALIGN(umem->iova + umem->length, pgsz) -
  65                          ALIGN_DOWN(umem->iova, pgsz))) /
  66                pgsz;
  67 }
  68
  69 static inline size_t ib_umem_num_pages(struct ib_umem *umem)
  70 {
  71         return ib_umem_num_dma_blocks(umem, PAGE_SIZE);
  72 }
  73
  74 static inline void __rdma_umem_block_iter_start(struct ib_block_iter *biter,
  75                                                 struct ib_umem *umem,
  76                                                 unsigned long pgsz)
  77 {
  78         __rdma_block_iter_start(biter, umem->sgt_append.sgt.sgl,
  79                                 umem->sgt_append.sgt.nents, pgsz);
  80 }
  81
  82 /**
  83  * rdma_umem_for_each_dma_block - iterate over contiguous DMA blocks of the umem
  84  * @umem: umem to iterate over
  85  * @pgsz: Page size to split the list into
  86  *
  87  * pgsz must be <= PAGE_SIZE or computed by ib_umem_find_best_pgsz(). The
  88  * returned DMA blocks will be aligned to pgsz and span the range:
  89  * ALIGN_DOWN(umem->address, pgsz) to ALIGN(umem->address + umem->length, pgsz)
  90  *
  91  * Performs exactly ib_umem_num_dma_blocks() iterations.
  92  */
  93 #define rdma_umem_for_each_dma_block(umem, biter, pgsz)                        \
  94         for (__rdma_umem_block_iter_start(biter, umem, pgsz);                  \
  95              __rdma_block_iter_next(biter);)
  96
  97 #ifdef CONFIG_INFINIBAND_USER_MEM
  98
  99 struct ib_umem *ib_umem_get(struct ib_device *device, unsigned long addr,
 100                             size_t size, int access);
 101 void ib_umem_release(struct ib_umem *umem);
 102 int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset,
 103                       size_t length);
 104 unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem,
 105                                      unsigned long pgsz_bitmap,
 106                                      unsigned long virt);
 107
 108 /**
 109  * ib_umem_find_best_pgoff - Find best HW page size
 110  *
 111  * @umem: umem struct
 112  * @pgsz_bitmap bitmap of HW supported page sizes
 113  * @pgoff_bitmask: Mask of bits that can be represented with an offset
 114  *
 115  * This is very similar to ib_umem_find_best_pgsz() except instead of accepting
 116  * an IOVA it accepts a bitmask specifying what address bits can be represented
 117  * with a page offset.
 118  *
 119  * For instance if the HW has multiple page sizes, requires 64 byte alignemnt,
 120  * and can support aligned offsets up to 4032 then pgoff_bitmask would be
 121  * "111111000000".
 122  *
 123  * If the pgoff_bitmask requires either alignment in the low bit or an
 124  * unavailable page size for the high bits, this function returns 0.
 125  */
 126 static inline unsigned long ib_umem_find_best_pgoff(struct ib_umem *umem,
 127                                                     unsigned long pgsz_bitmap,
 128                                                     u64 pgoff_bitmask)
 129 {
 130         struct scatterlist *sg = umem->sgt_append.sgt.sgl;
 131         dma_addr_t dma_addr;
 132
 133         dma_addr = sg_dma_address(sg) + (umem->address & ~PAGE_MASK);
 134         return ib_umem_find_best_pgsz(umem, pgsz_bitmap,
 135                                       dma_addr & pgoff_bitmask);
 136 }
 137
 138 struct ib_umem_dmabuf *ib_umem_dmabuf_get(struct ib_device *device,
 139                                           unsigned long offset, size_t size,
 140                                           int fd, int access,
 141                                           const struct dma_buf_attach_ops *ops);
 142 int ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf *umem_dmabuf);
 143 void ib_umem_dmabuf_unmap_pages(struct ib_umem_dmabuf *umem_dmabuf);
 144 void ib_umem_dmabuf_release(struct ib_umem_dmabuf *umem_dmabuf);
 145
 146 #else /* CONFIG_INFINIBAND_USER_MEM */
 147
 148 #include <linux/err.h>
 149
 150 static inline struct ib_umem *ib_umem_get(struct ib_device *device,
 151                                           unsigned long addr, size_t size,
 152                                           int access)
 153 {
 154         return ERR_PTR(-EOPNOTSUPP);
 155 }
 156 static inline void ib_umem_release(struct ib_umem *umem) { }
 157 static inline int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset,
 158                                     size_t length) {
 159         return -EOPNOTSUPP;
 160 }
 161 static inline unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem,
 162                                                    unsigned long pgsz_bitmap,
 163                                                    unsigned long virt)
 164 {
 165         return 0;
 166 }
 167 static inline unsigned long ib_umem_find_best_pgoff(struct ib_umem *umem,
 168                                                     unsigned long pgsz_bitmap,
 169                                                     u64 pgoff_bitmask)
 170 {
 171         return 0;
 172 }
 173 static inline
 174 struct ib_umem_dmabuf *ib_umem_dmabuf_get(struct ib_device *device,
 175                                           unsigned long offset,
 176                                           size_t size, int fd,
 177                                           int access,
 178                                           struct dma_buf_attach_ops *ops)
 179 {
 180         return ERR_PTR(-EOPNOTSUPP);
 181 }
 182 static inline int ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf *umem_dmabuf)
 183 {
 184         return -EOPNOTSUPP;
 185 }
 186 static inline void ib_umem_dmabuf_unmap_pages(struct ib_umem_dmabuf *umem_dmabuf) { }
 187 static inline void ib_umem_dmabuf_release(struct ib_umem_dmabuf *umem_dmabuf) { }
 188
 189 #endif /* CONFIG_INFINIBAND_USER_MEM */
 190 #endif /* IB_UMEM_H */