drivers/infiniband/hw/usnic/usnic_uiom_interval_tree.c

   1 /*
   2  * Copyright (c) 2014, Cisco Systems, Inc. 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  * 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
  34 #include <linux/init.h>
  35 #include <linux/list.h>
  36 #include <linux/slab.h>
  37 #include <linux/list_sort.h>
  38
  39 #include <linux/interval_tree_generic.h>
  40 #include "usnic_uiom_interval_tree.h"
  41
  42 #define START(node) ((node)->start)
  43 #define LAST(node) ((node)->last)
  44
  45 #define MAKE_NODE(node, start, end, ref_cnt, flags, err, err_out)       \
  46                 do {                                                    \
  47                         node = usnic_uiom_interval_node_alloc(start,    \
  48                                         end, ref_cnt, flags);           \
  49                                 if (!node) {                            \
  50                                         err = -ENOMEM;                  \
  51                                         goto err_out;                   \
  52                                 }                                       \
  53                 } while (0)
  54
  55 #define MARK_FOR_ADD(node, list) (list_add_tail(&node->link, list))
  56
  57 #define MAKE_NODE_AND_APPEND(node, start, end, ref_cnt, flags, err,     \
  58                                 err_out, list)                          \
  59                                 do {                                    \
  60                                         MAKE_NODE(node, start, end,     \
  61                                                 ref_cnt, flags, err,    \
  62                                                 err_out);               \
  63                                         MARK_FOR_ADD(node, list);       \
  64                                 } while (0)
  65
  66 #define FLAGS_EQUAL(flags1, flags2, mask)                               \
  67                         (((flags1) & (mask)) == ((flags2) & (mask)))
  68
  69 static struct usnic_uiom_interval_node*
  70 usnic_uiom_interval_node_alloc(long int start, long int last, int ref_cnt,
  71                                 int flags)
  72 {
  73         struct usnic_uiom_interval_node *interval = kzalloc(sizeof(*interval),
  74                                                                 GFP_ATOMIC);
  75         if (!interval)
  76                 return NULL;
  77
  78         interval->start = start;
  79         interval->last = last;
  80         interval->flags = flags;
  81         interval->ref_cnt = ref_cnt;
  82
  83         return interval;
  84 }
  85
  86 static int interval_cmp(void *priv, struct list_head *a, struct list_head *b)
  87 {
  88         struct usnic_uiom_interval_node *node_a, *node_b;
  89
  90         node_a = list_entry(a, struct usnic_uiom_interval_node, link);
  91         node_b = list_entry(b, struct usnic_uiom_interval_node, link);
  92
  93         /* long to int */
  94         if (node_a->start < node_b->start)
  95                 return -1;
  96         else if (node_a->start > node_b->start)
  97                 return 1;
  98
  99         return 0;
 100 }
 101
 102 static void
 103 find_intervals_intersection_sorted(struct rb_root *root, unsigned long start,
 104                                         unsigned long last,
 105                                         struct list_head *list)
 106 {
 107         struct usnic_uiom_interval_node *node;
 108
 109         INIT_LIST_HEAD(list);
 110
 111         for (node = usnic_uiom_interval_tree_iter_first(root, start, last);
 112                 node;
 113                 node = usnic_uiom_interval_tree_iter_next(node, start, last))
 114                 list_add_tail(&node->link, list);
 115
 116         list_sort(NULL, list, interval_cmp);
 117 }
 118
 119 int usnic_uiom_get_intervals_diff(unsigned long start, unsigned long last,
 120                                         int flags, int flag_mask,
 121                                         struct rb_root *root,
 122                                         struct list_head *diff_set)
 123 {
 124         struct usnic_uiom_interval_node *interval, *tmp;
 125         int err = 0;
 126         long int pivot = start;
 127         LIST_HEAD(intersection_set);
 128
 129         INIT_LIST_HEAD(diff_set);
 130
 131         find_intervals_intersection_sorted(root, start, last,
 132                                                 &intersection_set);
 133
 134         list_for_each_entry(interval, &intersection_set, link) {
 135                 if (pivot < interval->start) {
 136                         MAKE_NODE_AND_APPEND(tmp, pivot, interval->start - 1,
 137                                                 1, flags, err, err_out,
 138                                                 diff_set);
 139                         pivot = interval->start;
 140                 }
 141
 142                 /*
 143                  * Invariant: Set [start, pivot] is either in diff_set or root,
 144                  * but not in both.
 145                  */
 146
 147                 if (pivot > interval->last) {
 148                         continue;
 149                 } else if (pivot <= interval->last &&
 150                                 FLAGS_EQUAL(interval->flags, flags,
 151                                 flag_mask)) {
 152                         pivot = interval->last + 1;
 153                 }
 154         }
 155
 156         if (pivot <= last)
 157                 MAKE_NODE_AND_APPEND(tmp, pivot, last, 1, flags, err, err_out,
 158                                         diff_set);
 159
 160         return 0;
 161
 162 err_out:
 163         list_for_each_entry_safe(interval, tmp, diff_set, link) {
 164                 list_del(&interval->link);
 165                 kfree(interval);
 166         }
 167
 168         return err;
 169 }
 170
 171 void usnic_uiom_put_interval_set(struct list_head *intervals)
 172 {
 173         struct usnic_uiom_interval_node *interval, *tmp;
 174         list_for_each_entry_safe(interval, tmp, intervals, link)
 175                 kfree(interval);
 176 }
 177
 178 int usnic_uiom_insert_interval(struct rb_root *root, unsigned long start,
 179                                 unsigned long last, int flags)
 180 {
 181         struct usnic_uiom_interval_node *interval, *tmp;
 182         unsigned long istart, ilast;
 183         int iref_cnt, iflags;
 184         unsigned long lpivot = start;
 185         int err = 0;
 186         LIST_HEAD(to_add);
 187         LIST_HEAD(intersection_set);
 188
 189         find_intervals_intersection_sorted(root, start, last,
 190                                                 &intersection_set);
 191
 192         list_for_each_entry(interval, &intersection_set, link) {
 193                 /*
 194                  * Invariant - lpivot is the left edge of next interval to be
 195                  * inserted
 196                  */
 197                 istart = interval->start;
 198                 ilast = interval->last;
 199                 iref_cnt = interval->ref_cnt;
 200                 iflags = interval->flags;
 201
 202                 if (istart < lpivot) {
 203                         MAKE_NODE_AND_APPEND(tmp, istart, lpivot - 1, iref_cnt,
 204                                                 iflags, err, err_out, &to_add);
 205                 } else if (istart > lpivot) {
 206                         MAKE_NODE_AND_APPEND(tmp, lpivot, istart - 1, 1, flags,
 207                                                 err, err_out, &to_add);
 208                         lpivot = istart;
 209                 } else {
 210                         lpivot = istart;
 211                 }
 212
 213                 if (ilast > last) {
 214                         MAKE_NODE_AND_APPEND(tmp, lpivot, last, iref_cnt + 1,
 215                                                 iflags | flags, err, err_out,
 216                                                 &to_add);
 217                         MAKE_NODE_AND_APPEND(tmp, last + 1, ilast, iref_cnt,
 218                                                 iflags, err, err_out, &to_add);
 219                 } else {
 220                         MAKE_NODE_AND_APPEND(tmp, lpivot, ilast, iref_cnt + 1,
 221                                                 iflags | flags, err, err_out,
 222                                                 &to_add);
 223                 }
 224
 225                 lpivot = ilast + 1;
 226         }
 227
 228         if (lpivot <= last)
 229                 MAKE_NODE_AND_APPEND(tmp, lpivot, last, 1, flags, err, err_out,
 230                                         &to_add);
 231
 232         list_for_each_entry_safe(interval, tmp, &intersection_set, link) {
 233                 usnic_uiom_interval_tree_remove(interval, root);
 234                 kfree(interval);
 235         }
 236
 237         list_for_each_entry(interval, &to_add, link)
 238                 usnic_uiom_interval_tree_insert(interval, root);
 239
 240         return 0;
 241
 242 err_out:
 243         list_for_each_entry_safe(interval, tmp, &to_add, link)
 244                 kfree(interval);
 245
 246         return err;
 247 }
 248
 249 void usnic_uiom_remove_interval(struct rb_root *root, unsigned long start,
 250                                 unsigned long last, struct list_head *removed)
 251 {
 252         struct usnic_uiom_interval_node *interval;
 253
 254         for (interval = usnic_uiom_interval_tree_iter_first(root, start, last);
 255                         interval;
 256                         interval = usnic_uiom_interval_tree_iter_next(interval,
 257                                                                         start,
 258                                                                         last)) {
 259                 if (--interval->ref_cnt == 0)
 260                         list_add_tail(&interval->link, removed);
 261         }
 262
 263         list_for_each_entry(interval, removed, link)
 264                 usnic_uiom_interval_tree_remove(interval, root);
 265 }
 266
 267 INTERVAL_TREE_DEFINE(struct usnic_uiom_interval_node, rb,
 268                         unsigned long, __subtree_last,
 269                         START, LAST, , usnic_uiom_interval_tree)