LXR linux/drivers/infiniband/hw/usnic/usnic_uiom_interval

   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
  69static struct usnic_uiom_interval_node*
  70usnic_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
  86static 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
 102static void
 103find_intervals_intersection_sorted(struct rb_root_cached *root,
 104                                   unsigned long start, 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
 119int usnic_uiom_get_intervals_diff(unsigned long start, unsigned long last,
 120                                        int flags, int flag_mask,
 121                                        struct rb_root_cached *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
 162err_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
 171void 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
 178int usnic_uiom_insert_interval(struct rb_root_cached *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
 242err_out:
 243        list_for_each_entry_safe(interval, tmp, &to_add, link)
 244                kfree(interval);
 245
 246        return err;
 247}
 248
 249void usnic_uiom_remove_interval(struct rb_root_cached *root,
 250                                unsigned long start, unsigned long last,
 251                                struct list_head *removed)
 252{
 253        struct usnic_uiom_interval_node *interval;
 254
 255        for (interval = usnic_uiom_interval_tree_iter_first(root, start, last);
 256                        interval;
 257                        interval = usnic_uiom_interval_tree_iter_next(interval,
 258                                                                        start,
 259                                                                        last)) {
 260                if (--interval->ref_cnt == 0)
 261                        list_add_tail(&interval->link, removed);
 262        }
 263
 264        list_for_each_entry(interval, removed, link)
 265                usnic_uiom_interval_tree_remove(interval, root);
 266}
 267
 268INTERVAL_TREE_DEFINE(struct usnic_uiom_interval_node, rb,
 269                        unsigned long, __subtree_last,
 270                        START, LAST, , usnic_uiom_interval_tree)
 271