drivers/net/ethernet/mellanox/mlx5/core/fs_counters.c

   1 /*
   2  * Copyright (c) 2016, 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/mlx5/driver.h>
  34 #include <linux/mlx5/fs.h>
  35 #include <linux/rbtree.h>
  36 #include "mlx5_core.h"
  37 #include "fs_core.h"
  38 #include "fs_cmd.h"
  39
  40 #define MLX5_FC_STATS_PERIOD msecs_to_jiffies(1000)
  41
  42 /* locking scheme:
  43  *
  44  * It is the responsibility of the user to prevent concurrent calls or bad
  45  * ordering to mlx5_fc_create(), mlx5_fc_destroy() and accessing a reference
  46  * to struct mlx5_fc.
  47  * e.g en_tc.c is protected by RTNL lock of its caller, and will never call a
  48  * dump (access to struct mlx5_fc) after a counter is destroyed.
  49  *
  50  * access to counter list:
  51  * - create (user context)
  52  *   - mlx5_fc_create() only adds to an addlist to be used by
  53  *     mlx5_fc_stats_query_work(). addlist is protected by a spinlock.
  54  *   - spawn thread to do the actual destroy
  55  *
  56  * - destroy (user context)
  57  *   - mark a counter as deleted
  58  *   - spawn thread to do the actual del
  59  *
  60  * - dump (user context)
  61  *   user should not call dump after destroy
  62  *
  63  * - query (single thread workqueue context)
  64  *   destroy/dump - no conflict (see destroy)
  65  *   query/dump - packets and bytes might be inconsistent (since update is not
  66  *                atomic)
  67  *   query/create - no conflict (see create)
  68  *   since every create/destroy spawn the work, only after necessary time has
  69  *   elapsed, the thread will actually query the hardware.
  70  */
  71
  72 static void mlx5_fc_stats_insert(struct rb_root *root, struct mlx5_fc *counter)
  73 {
  74         struct rb_node **new = &root->rb_node;
  75         struct rb_node *parent = NULL;
  76
  77         while (*new) {
  78                 struct mlx5_fc *this = container_of(*new, struct mlx5_fc, node);
  79                 int result = counter->id - this->id;
  80
  81                 parent = *new;
  82                 if (result < 0)
  83                         new = &((*new)->rb_left);
  84                 else
  85                         new = &((*new)->rb_right);
  86         }
  87
  88         /* Add new node and rebalance tree. */
  89         rb_link_node(&counter->node, parent, new);
  90         rb_insert_color(&counter->node, root);
  91 }
  92
  93 static struct rb_node *mlx5_fc_stats_query(struct mlx5_core_dev *dev,
  94                                            struct mlx5_fc *first,
  95                                            u16 last_id)
  96 {
  97         struct mlx5_cmd_fc_bulk *b;
  98         struct rb_node *node = NULL;
  99         u16 afirst_id;
 100         int num;
 101         int err;
 102         int max_bulk = 1 << MLX5_CAP_GEN(dev, log_max_flow_counter_bulk);
 103
 104         /* first id must be aligned to 4 when using bulk query */
 105         afirst_id = first->id & ~0x3;
 106
 107         /* number of counters to query inc. the last counter */
 108         num = ALIGN(last_id - afirst_id + 1, 4);
 109         if (num > max_bulk) {
 110                 num = max_bulk;
 111                 last_id = afirst_id + num - 1;
 112         }
 113
 114         b = mlx5_cmd_fc_bulk_alloc(dev, afirst_id, num);
 115         if (!b) {
 116                 mlx5_core_err(dev, "Error allocating resources for bulk query\n");
 117                 return NULL;
 118         }
 119
 120         err = mlx5_cmd_fc_bulk_query(dev, b);
 121         if (err) {
 122                 mlx5_core_err(dev, "Error doing bulk query: %d\n", err);
 123                 goto out;
 124         }
 125
 126         for (node = &first->node; node; node = rb_next(node)) {
 127                 struct mlx5_fc *counter = rb_entry(node, struct mlx5_fc, node);
 128                 struct mlx5_fc_cache *c = &counter->cache;
 129
 130                 if (counter->id > last_id)
 131                         break;
 132
 133                 mlx5_cmd_fc_bulk_get(dev, b,
 134                                      counter->id, &c->packets, &c->bytes);
 135         }
 136
 137 out:
 138         mlx5_cmd_fc_bulk_free(b);
 139
 140         return node;
 141 }
 142
 143 static void mlx5_fc_stats_work(struct work_struct *work)
 144 {
 145         struct mlx5_core_dev *dev = container_of(work, struct mlx5_core_dev,
 146                                                  priv.fc_stats.work.work);
 147         struct mlx5_fc_stats *fc_stats = &dev->priv.fc_stats;
 148         unsigned long now = jiffies;
 149         struct mlx5_fc *counter = NULL;
 150         struct mlx5_fc *last = NULL;
 151         struct rb_node *node;
 152         LIST_HEAD(tmplist);
 153
 154         spin_lock(&fc_stats->addlist_lock);
 155
 156         list_splice_tail_init(&fc_stats->addlist, &tmplist);
 157
 158         if (!list_empty(&tmplist) || !RB_EMPTY_ROOT(&fc_stats->counters))
 159                 queue_delayed_work(fc_stats->wq, &fc_stats->work, MLX5_FC_STATS_PERIOD);
 160
 161         spin_unlock(&fc_stats->addlist_lock);
 162
 163         list_for_each_entry(counter, &tmplist, list)
 164                 mlx5_fc_stats_insert(&fc_stats->counters, counter);
 165
 166         node = rb_first(&fc_stats->counters);
 167         while (node) {
 168                 counter = rb_entry(node, struct mlx5_fc, node);
 169
 170                 node = rb_next(node);
 171
 172                 if (counter->deleted) {
 173                         rb_erase(&counter->node, &fc_stats->counters);
 174
 175                         mlx5_cmd_fc_free(dev, counter->id);
 176
 177                         kfree(counter);
 178                         continue;
 179                 }
 180
 181                 last = counter;
 182         }
 183
 184         if (time_before(now, fc_stats->next_query) || !last)
 185                 return;
 186
 187         node = rb_first(&fc_stats->counters);
 188         while (node) {
 189                 counter = rb_entry(node, struct mlx5_fc, node);
 190
 191                 node = mlx5_fc_stats_query(dev, counter, last->id);
 192         }
 193
 194         fc_stats->next_query = now + MLX5_FC_STATS_PERIOD;
 195 }
 196
 197 struct mlx5_fc *mlx5_fc_create(struct mlx5_core_dev *dev, bool aging)
 198 {
 199         struct mlx5_fc_stats *fc_stats = &dev->priv.fc_stats;
 200         struct mlx5_fc *counter;
 201         int err;
 202
 203         counter = kzalloc(sizeof(*counter), GFP_KERNEL);
 204         if (!counter)
 205                 return ERR_PTR(-ENOMEM);
 206
 207         err = mlx5_cmd_fc_alloc(dev, &counter->id);
 208         if (err)
 209                 goto err_out;
 210
 211         if (aging) {
 212                 counter->aging = true;
 213
 214                 spin_lock(&fc_stats->addlist_lock);
 215                 list_add(&counter->list, &fc_stats->addlist);
 216                 spin_unlock(&fc_stats->addlist_lock);
 217
 218                 mod_delayed_work(fc_stats->wq, &fc_stats->work, 0);
 219         }
 220
 221         return counter;
 222
 223 err_out:
 224         kfree(counter);
 225
 226         return ERR_PTR(err);
 227 }
 228
 229 void mlx5_fc_destroy(struct mlx5_core_dev *dev, struct mlx5_fc *counter)
 230 {
 231         struct mlx5_fc_stats *fc_stats = &dev->priv.fc_stats;
 232
 233         if (!counter)
 234                 return;
 235
 236         if (counter->aging) {
 237                 counter->deleted = true;
 238                 mod_delayed_work(fc_stats->wq, &fc_stats->work, 0);
 239                 return;
 240         }
 241
 242         mlx5_cmd_fc_free(dev, counter->id);
 243         kfree(counter);
 244 }
 245
 246 int mlx5_init_fc_stats(struct mlx5_core_dev *dev)
 247 {
 248         struct mlx5_fc_stats *fc_stats = &dev->priv.fc_stats;
 249
 250         fc_stats->counters = RB_ROOT;
 251         INIT_LIST_HEAD(&fc_stats->addlist);
 252         spin_lock_init(&fc_stats->addlist_lock);
 253
 254         fc_stats->wq = create_singlethread_workqueue("mlx5_fc");
 255         if (!fc_stats->wq)
 256                 return -ENOMEM;
 257
 258         INIT_DELAYED_WORK(&fc_stats->work, mlx5_fc_stats_work);
 259
 260         return 0;
 261 }
 262
 263 void mlx5_cleanup_fc_stats(struct mlx5_core_dev *dev)
 264 {
 265         struct mlx5_fc_stats *fc_stats = &dev->priv.fc_stats;
 266         struct mlx5_fc *counter;
 267         struct mlx5_fc *tmp;
 268         struct rb_node *node;
 269
 270         cancel_delayed_work_sync(&dev->priv.fc_stats.work);
 271         destroy_workqueue(dev->priv.fc_stats.wq);
 272         dev->priv.fc_stats.wq = NULL;
 273
 274         list_for_each_entry_safe(counter, tmp, &fc_stats->addlist, list) {
 275                 list_del(&counter->list);
 276
 277                 mlx5_cmd_fc_free(dev, counter->id);
 278
 279                 kfree(counter);
 280         }
 281
 282         node = rb_first(&fc_stats->counters);
 283         while (node) {
 284                 counter = rb_entry(node, struct mlx5_fc, node);
 285
 286                 node = rb_next(node);
 287
 288                 rb_erase(&counter->node, &fc_stats->counters);
 289
 290                 mlx5_cmd_fc_free(dev, counter->id);
 291
 292                 kfree(counter);
 293         }
 294 }
 295
 296 void mlx5_fc_query_cached(struct mlx5_fc *counter,
 297                           u64 *bytes, u64 *packets, u64 *lastuse)
 298 {
 299         struct mlx5_fc_cache c;
 300
 301         c = counter->cache;
 302
 303         *bytes = c.bytes - counter->lastbytes;
 304         *packets = c.packets - counter->lastpackets;
 305         *lastuse = c.lastuse;
 306
 307         counter->lastbytes = c.bytes;
 308         counter->lastpackets = c.packets;
 309 }