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