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  */
   5
   6 #ifndef IB_UMEM_H
   7 #define IB_UMEM_H
   8
   9 #include <linux/list.h>
  10 #include <linux/scatterlist.h>
  11 #include <linux/workqueue.h>
  12 #include <rdma/ib_verbs.h>
  13
  14 struct ib_ucontext;
  15 struct ib_umem_odp;
  16
  17 struct ib_umem {
  18         struct ib_device       *ibdev;
  19         struct mm_struct       *owning_mm;
  20         u64 iova;
  21         size_t                  length;
  22         unsigned long           address;
  23         u32 writable : 1;
  24         u32 is_odp : 1;
  25         struct work_struct      work;
  26         struct sg_table sg_head;
  27         int             nmap;
  28         unsigned int    sg_nents;
  29 };
  30
  31 /* Returns the offset of the umem start relative to the first page. */
  32 static inline int ib_umem_offset(struct ib_umem *umem)
  33 {
  34         return umem->address & ~PAGE_MASK;
  35 }
  36
  37 static inline unsigned long ib_umem_dma_offset(struct ib_umem *umem,
  38                                                unsigned long pgsz)
  39 {
  40         return (sg_dma_address(umem->sg_head.sgl) + ib_umem_offset(umem)) &
  41                (pgsz - 1);
  42 }
  43
  44 static inline size_t ib_umem_num_dma_blocks(struct ib_umem *umem,
  45                                             unsigned long pgsz)
  46 {
  47         return (size_t)((ALIGN(umem->iova + umem->length, pgsz) -
  48                          ALIGN_DOWN(umem->iova, pgsz))) /
  49                pgsz;
  50 }
  51
  52 static inline size_t ib_umem_num_pages(struct ib_umem *umem)
  53 {
  54         return ib_umem_num_dma_blocks(umem, PAGE_SIZE);
  55 }
  56
  57 static inline void __rdma_umem_block_iter_start(struct ib_block_iter *biter,
  58                                                 struct ib_umem *umem,
  59                                                 unsigned long pgsz)
  60 {
  61         __rdma_block_iter_start(biter, umem->sg_head.sgl, umem->nmap, pgsz);
  62 }
  63
  64 /**
  65  * rdma_umem_for_each_dma_block - iterate over contiguous DMA blocks of the umem
  66  * @umem: umem to iterate over
  67  * @pgsz: Page size to split the list into
  68  *
  69  * pgsz must be <= PAGE_SIZE or computed by ib_umem_find_best_pgsz(). The
  70  * returned DMA blocks will be aligned to pgsz and span the range:
  71  * ALIGN_DOWN(umem->address, pgsz) to ALIGN(umem->address + umem->length, pgsz)
  72  *
  73  * Performs exactly ib_umem_num_dma_blocks() iterations.
  74  */
  75 #define rdma_umem_for_each_dma_block(umem, biter, pgsz)                        \
  76         for (__rdma_umem_block_iter_start(biter, umem, pgsz);                  \
  77              __rdma_block_iter_next(biter);)
  78
  79 #ifdef CONFIG_INFINIBAND_USER_MEM
  80
  81 struct ib_umem *ib_umem_get(struct ib_device *device, unsigned long addr,
  82                             size_t size, int access);
  83 void ib_umem_release(struct ib_umem *umem);
  84 int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset,
  85                       size_t length);
  86 unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem,
  87                                      unsigned long pgsz_bitmap,
  88                                      unsigned long virt);
  89 /**
  90  * ib_umem_find_best_pgoff - Find best HW page size
  91  *
  92  * @umem: umem struct
  93  * @pgsz_bitmap bitmap of HW supported page sizes
  94  * @pgoff_bitmask: Mask of bits that can be represented with an offset
  95  *
  96  * This is very similar to ib_umem_find_best_pgsz() except instead of accepting
  97  * an IOVA it accepts a bitmask specifying what address bits can be represented
  98  * with a page offset.
  99  *
 100  * For instance if the HW has multiple page sizes, requires 64 byte alignemnt,
 101  * and can support aligned offsets up to 4032 then pgoff_bitmask would be
 102  * "111111000000".
 103  *
 104  * If the pgoff_bitmask requires either alignment in the low bit or an
 105  * unavailable page size for the high bits, this function returns 0.
 106  */
 107 static inline unsigned long ib_umem_find_best_pgoff(struct ib_umem *umem,
 108                                                     unsigned long pgsz_bitmap,
 109                                                     u64 pgoff_bitmask)
 110 {
 111         struct scatterlist *sg = umem->sg_head.sgl;
 112         dma_addr_t dma_addr;
 113
 114         dma_addr = sg_dma_address(sg) + (umem->address & ~PAGE_MASK);
 115         return ib_umem_find_best_pgsz(umem, pgsz_bitmap,
 116                                       dma_addr & pgoff_bitmask);
 117 }
 118
 119 #else /* CONFIG_INFINIBAND_USER_MEM */
 120
 121 #include <linux/err.h>
 122
 123 static inline struct ib_umem *ib_umem_get(struct ib_device *device,
 124                                           unsigned long addr, size_t size,
 125                                           int access)
 126 {
 127         return ERR_PTR(-EINVAL);
 128 }
 129 static inline void ib_umem_release(struct ib_umem *umem) { }
 130 static inline int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset,
 131                                     size_t length) {
 132         return -EINVAL;
 133 }
 134 static inline unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem,
 135                                                    unsigned long pgsz_bitmap,
 136                                                    unsigned long virt)
 137 {
 138         return 0;
 139 }
 140 static inline unsigned long ib_umem_find_best_pgoff(struct ib_umem *umem,
 141                                                     unsigned long pgsz_bitmap,
 142                                                     u64 pgoff_bitmask)
 143 {
 144         return 0;
 145 }
 146
 147 #endif /* CONFIG_INFINIBAND_USER_MEM */
 148
 149 #endif /* IB_UMEM_H */