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 size_t ib_umem_num_dma_blocks(struct ib_umem *umem,
  38                                             unsigned long pgsz)
  39 {
  40         return (size_t)((ALIGN(umem->iova + umem->length, pgsz) -
  41                          ALIGN_DOWN(umem->iova, pgsz))) /
  42                pgsz;
  43 }
  44
  45 static inline size_t ib_umem_num_pages(struct ib_umem *umem)
  46 {
  47         return ib_umem_num_dma_blocks(umem, PAGE_SIZE);
  48 }
  49
  50 static inline void __rdma_umem_block_iter_start(struct ib_block_iter *biter,
  51                                                 struct ib_umem *umem,
  52                                                 unsigned long pgsz)
  53 {
  54         __rdma_block_iter_start(biter, umem->sg_head.sgl, umem->nmap, pgsz);
  55 }
  56
  57 /**
  58  * rdma_umem_for_each_dma_block - iterate over contiguous DMA blocks of the umem
  59  * @umem: umem to iterate over
  60  * @pgsz: Page size to split the list into
  61  *
  62  * pgsz must be <= PAGE_SIZE or computed by ib_umem_find_best_pgsz(). The
  63  * returned DMA blocks will be aligned to pgsz and span the range:
  64  * ALIGN_DOWN(umem->address, pgsz) to ALIGN(umem->address + umem->length, pgsz)
  65  *
  66  * Performs exactly ib_umem_num_dma_blocks() iterations.
  67  */
  68 #define rdma_umem_for_each_dma_block(umem, biter, pgsz)                        \
  69         for (__rdma_umem_block_iter_start(biter, umem, pgsz);                  \
  70              __rdma_block_iter_next(biter);)
  71
  72 #ifdef CONFIG_INFINIBAND_USER_MEM
  73
  74 struct ib_umem *ib_umem_get(struct ib_device *device, unsigned long addr,
  75                             size_t size, int access);
  76 void ib_umem_release(struct ib_umem *umem);
  77 int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset,
  78                       size_t length);
  79 unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem,
  80                                      unsigned long pgsz_bitmap,
  81                                      unsigned long virt);
  82
  83 #else /* CONFIG_INFINIBAND_USER_MEM */
  84
  85 #include <linux/err.h>
  86
  87 static inline struct ib_umem *ib_umem_get(struct ib_device *device,
  88                                           unsigned long addr, size_t size,
  89                                           int access)
  90 {
  91         return ERR_PTR(-EINVAL);
  92 }
  93 static inline void ib_umem_release(struct ib_umem *umem) { }
  94 static inline int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset,
  95                                     size_t length) {
  96         return -EINVAL;
  97 }
  98 static inline unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem,
  99                                                    unsigned long pgsz_bitmap,
 100                                                    unsigned long virt)
 101 {
 102         return 0;
 103 }
 104
 105 #endif /* CONFIG_INFINIBAND_USER_MEM */
 106
 107 #endif /* IB_UMEM_H */