drivers/infiniband/core/umem_rbtree.c

   1 /*
   2  * Copyright (c) 2014 Mellanox Technologies. All rights reserved.
   3  *
   4  * This software is available to you under a choice of one of two
   5  * licenses.  You may choose to be licensed under the terms of the GNU
   6  * General Public License (GPL) Version 2, available from the file
   7  * COPYING in the main directory of this source tree, or the
   8  * OpenIB.org BSD license below:
   9  *
  10  *     Redistribution and use in source and binary forms, with or
  11  *     without modification, are permitted provided that the following
  12  *     conditions are met:
  13  *
  14  *      - Redistributions of source code must retain the above
  15  *        copyright notice, this list of conditions and the following
  16  *        disclaimer.
  17  *
  18  *      - Redistributions in binary form must reproduce the above
  19  *        copyright notice, this list of conditions and the following
  20  *        disclaimer in the documentation and/or other materials
  21  *        provided with the distribution.
  22  *
  23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  30  * SOFTWARE.
  31  */
  32
  33 #include <linux/kernel.h>
  34 #include <linux/module.h>
  35 #include <linux/interval_tree_generic.h>
  36 #include <linux/sched.h>
  37 #include <linux/gfp.h>
  38 #include <rdma/ib_umem_odp.h>
  39
  40 /*
  41  * The ib_umem list keeps track of memory regions for which the HW
  42  * device request to receive notification when the related memory
  43  * mapping is changed.
  44  *
  45  * ib_umem_lock protects the list.
  46  */
  47
  48 static inline u64 node_start(struct umem_odp_node *n)
  49 {
  50         struct ib_umem_odp *umem_odp =
  51                         container_of(n, struct ib_umem_odp, interval_tree);
  52
  53         return ib_umem_start(umem_odp->umem);
  54 }
  55
  56 /* Note that the representation of the intervals in the interval tree
  57  * considers the ending point as contained in the interval, while the
  58  * function ib_umem_end returns the first address which is not contained
  59  * in the umem.
  60  */
  61 static inline u64 node_last(struct umem_odp_node *n)
  62 {
  63         struct ib_umem_odp *umem_odp =
  64                         container_of(n, struct ib_umem_odp, interval_tree);
  65
  66         return ib_umem_end(umem_odp->umem) - 1;
  67 }
  68
  69 INTERVAL_TREE_DEFINE(struct umem_odp_node, rb, u64, __subtree_last,
  70                      node_start, node_last, , rbt_ib_umem)
  71
  72 /* @last is not a part of the interval. See comment for function
  73  * node_last.
  74  */
  75 int rbt_ib_umem_for_each_in_range(struct rb_root *root,
  76                                   u64 start, u64 last,
  77                                   umem_call_back cb,
  78                                   void *cookie)
  79 {
  80         int ret_val = 0;
  81         struct umem_odp_node *node;
  82         struct ib_umem_odp *umem;
  83
  84         if (unlikely(start == last))
  85                 return ret_val;
  86
  87         for (node = rbt_ib_umem_iter_first(root, start, last - 1); node;
  88                         node = rbt_ib_umem_iter_next(node, start, last - 1)) {
  89                 umem = container_of(node, struct ib_umem_odp, interval_tree);
  90                 ret_val = cb(umem->umem, start, last, cookie) || ret_val;
  91         }
  92
  93         return ret_val;
  94 }