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 /* Max number of counters to query in bulk read is 32K */
  42 #define MLX5_SW_MAX_COUNTERS_BULK BIT(15)
  43
  44 struct mlx5_fc_cache {
  45         u64 packets;
  46         u64 bytes;
  47         u64 lastuse;
  48 };
  49
  50 struct mlx5_fc {
  51         struct list_head list;
  52         struct llist_node addlist;
  53         struct llist_node dellist;
  54
  55         /* last{packets,bytes} members are used when calculating the delta since
  56          * last reading
  57          */
  58         u64 lastpackets;
  59         u64 lastbytes;
  60
  61         u32 id;
  62         bool aging;
  63
  64         struct mlx5_fc_cache cache ____cacheline_aligned_in_smp;
  65 };
  66
  67 /* locking scheme:
  68  *
  69  * It is the responsibility of the user to prevent concurrent calls or bad
  70  * ordering to mlx5_fc_create(), mlx5_fc_destroy() and accessing a reference
  71  * to struct mlx5_fc.
  72  * e.g en_tc.c is protected by RTNL lock of its caller, and will never call a
  73  * dump (access to struct mlx5_fc) after a counter is destroyed.
  74  *
  75  * access to counter list:
  76  * - create (user context)
  77  *   - mlx5_fc_create() only adds to an addlist to be used by
  78  *     mlx5_fc_stats_query_work(). addlist is a lockless single linked list
  79  *     that doesn't require any additional synchronization when adding single
  80  *     node.
  81  *   - spawn thread to do the actual destroy
  82  *
  83  * - destroy (user context)
  84  *   - add a counter to lockless dellist
  85  *   - spawn thread to do the actual del
  86  *
  87  * - dump (user context)
  88  *   user should not call dump after destroy
  89  *
  90  * - query (single thread workqueue context)
  91  *   destroy/dump - no conflict (see destroy)
  92  *   query/dump - packets and bytes might be inconsistent (since update is not
  93  *                atomic)
  94  *   query/create - no conflict (see create)
  95  *   since every create/destroy spawn the work, only after necessary time has
  96  *   elapsed, the thread will actually query the hardware.
  97  */
  98
  99 static struct list_head *mlx5_fc_counters_lookup_next(struct mlx5_core_dev *dev,
 100                                                       u32 id)
 101 {
 102         struct mlx5_fc_stats *fc_stats = &dev->priv.fc_stats;
 103         unsigned long next_id = (unsigned long)id + 1;
 104         struct mlx5_fc *counter;
 105         unsigned long tmp;
 106
 107         rcu_read_lock();
 108         /* skip counters that are in idr, but not yet in counters list */
 109         idr_for_each_entry_continue_ul(&fc_stats->counters_idr,
 110                                        counter, tmp, next_id) {
 111                 if (!list_empty(&counter->list))
 112                         break;
 113         }
 114         rcu_read_unlock();
 115
 116         return counter ? &counter->list : &fc_stats->counters;
 117 }
 118
 119 static void mlx5_fc_stats_insert(struct mlx5_core_dev *dev,
 120                                  struct mlx5_fc *counter)
 121 {
 122         struct list_head *next = mlx5_fc_counters_lookup_next(dev, counter->id);
 123
 124         list_add_tail(&counter->list, next);
 125 }
 126
 127 static void mlx5_fc_stats_remove(struct mlx5_core_dev *dev,
 128                                  struct mlx5_fc *counter)
 129 {
 130         struct mlx5_fc_stats *fc_stats = &dev->priv.fc_stats;
 131
 132         list_del(&counter->list);
 133
 134         spin_lock(&fc_stats->counters_idr_lock);
 135         WARN_ON(!idr_remove(&fc_stats->counters_idr, counter->id));
 136         spin_unlock(&fc_stats->counters_idr_lock);
 137 }
 138
 139 /* The function returns the last counter that was queried so the caller
 140  * function can continue calling it till all counters are queried.
 141  */
 142 static struct mlx5_fc *mlx5_fc_stats_query(struct mlx5_core_dev *dev,
 143                                            struct mlx5_fc *first,
 144                                            u32 last_id)
 145 {
 146         struct mlx5_fc_stats *fc_stats = &dev->priv.fc_stats;
 147         struct mlx5_fc *counter = NULL;
 148         struct mlx5_cmd_fc_bulk *b;
 149         bool more = false;
 150         u32 afirst_id;
 151         int num;
 152         int err;
 153
 154         int max_bulk = min_t(int, MLX5_SW_MAX_COUNTERS_BULK,
 155                              (1 << MLX5_CAP_GEN(dev, log_max_flow_counter_bulk)));
 156
 157         /* first id must be aligned to 4 when using bulk query */
 158         afirst_id = first->id & ~0x3;
 159
 160         /* number of counters to query inc. the last counter */
 161         num = ALIGN(last_id - afirst_id + 1, 4);
 162         if (num > max_bulk) {
 163                 num = max_bulk;
 164                 last_id = afirst_id + num - 1;
 165         }
 166
 167         b = mlx5_cmd_fc_bulk_alloc(dev, afirst_id, num);
 168         if (!b) {
 169                 mlx5_core_err(dev, "Error allocating resources for bulk query\n");
 170                 return NULL;
 171         }
 172
 173         err = mlx5_cmd_fc_bulk_query(dev, b);
 174         if (err) {
 175                 mlx5_core_err(dev, "Error doing bulk query: %d\n", err);
 176                 goto out;
 177         }
 178
 179         counter = first;
 180         list_for_each_entry_from(counter, &fc_stats->counters, list) {
 181                 struct mlx5_fc_cache *c = &counter->cache;
 182                 u64 packets;
 183                 u64 bytes;
 184
 185                 if (counter->id > last_id) {
 186                         more = true;
 187                         break;
 188                 }
 189
 190                 mlx5_cmd_fc_bulk_get(dev, b,
 191                                      counter->id, &packets, &bytes);
 192
 193                 if (c->packets == packets)
 194                         continue;
 195
 196                 c->packets = packets;
 197                 c->bytes = bytes;
 198                 c->lastuse = jiffies;
 199         }
 200
 201 out:
 202         mlx5_cmd_fc_bulk_free(b);
 203
 204         return more ? counter : NULL;
 205 }
 206
 207 static void mlx5_free_fc(struct mlx5_core_dev *dev,
 208                          struct mlx5_fc *counter)
 209 {
 210         mlx5_cmd_fc_free(dev, counter->id);
 211         kfree(counter);
 212 }
 213
 214 static void mlx5_fc_stats_work(struct work_struct *work)
 215 {
 216         struct mlx5_core_dev *dev = container_of(work, struct mlx5_core_dev,
 217                                                  priv.fc_stats.work.work);
 218         struct mlx5_fc_stats *fc_stats = &dev->priv.fc_stats;
 219         /* Take dellist first to ensure that counters cannot be deleted before
 220          * they are inserted.
 221          */
 222         struct llist_node *dellist = llist_del_all(&fc_stats->dellist);
 223         struct llist_node *addlist = llist_del_all(&fc_stats->addlist);
 224         struct mlx5_fc *counter = NULL, *last = NULL, *tmp;
 225         unsigned long now = jiffies;
 226
 227         if (addlist || !list_empty(&fc_stats->counters))
 228                 queue_delayed_work(fc_stats->wq, &fc_stats->work,
 229                                    fc_stats->sampling_interval);
 230
 231         llist_for_each_entry(counter, addlist, addlist)
 232                 mlx5_fc_stats_insert(dev, counter);
 233
 234         llist_for_each_entry_safe(counter, tmp, dellist, dellist) {
 235                 mlx5_fc_stats_remove(dev, counter);
 236
 237                 mlx5_free_fc(dev, counter);
 238         }
 239
 240         if (time_before(now, fc_stats->next_query) ||
 241             list_empty(&fc_stats->counters))
 242                 return;
 243         last = list_last_entry(&fc_stats->counters, struct mlx5_fc, list);
 244
 245         counter = list_first_entry(&fc_stats->counters, struct mlx5_fc,
 246                                    list);
 247         while (counter)
 248                 counter = mlx5_fc_stats_query(dev, counter, last->id);
 249
 250         fc_stats->next_query = now + fc_stats->sampling_interval;
 251 }
 252
 253 struct mlx5_fc *mlx5_fc_create(struct mlx5_core_dev *dev, bool aging)
 254 {
 255         struct mlx5_fc_stats *fc_stats = &dev->priv.fc_stats;
 256         struct mlx5_fc *counter;
 257         int err;
 258
 259         counter = kzalloc(sizeof(*counter), GFP_KERNEL);
 260         if (!counter)
 261                 return ERR_PTR(-ENOMEM);
 262         INIT_LIST_HEAD(&counter->list);
 263
 264         err = mlx5_cmd_fc_alloc(dev, &counter->id);
 265         if (err)
 266                 goto err_out;
 267
 268         if (aging) {
 269                 u32 id = counter->id;
 270
 271                 counter->cache.lastuse = jiffies;
 272                 counter->aging = true;
 273
 274                 idr_preload(GFP_KERNEL);
 275                 spin_lock(&fc_stats->counters_idr_lock);
 276
 277                 err = idr_alloc_u32(&fc_stats->counters_idr, counter, &id, id,
 278                                     GFP_NOWAIT);
 279
 280                 spin_unlock(&fc_stats->counters_idr_lock);
 281                 idr_preload_end();
 282                 if (err)
 283                         goto err_out_alloc;
 284
 285                 llist_add(&counter->addlist, &fc_stats->addlist);
 286
 287                 mod_delayed_work(fc_stats->wq, &fc_stats->work, 0);
 288         }
 289
 290         return counter;
 291
 292 err_out_alloc:
 293         mlx5_cmd_fc_free(dev, counter->id);
 294 err_out:
 295         kfree(counter);
 296
 297         return ERR_PTR(err);
 298 }
 299 EXPORT_SYMBOL(mlx5_fc_create);
 300
 301 u32 mlx5_fc_id(struct mlx5_fc *counter)
 302 {
 303         return counter->id;
 304 }
 305 EXPORT_SYMBOL(mlx5_fc_id);
 306
 307 void mlx5_fc_destroy(struct mlx5_core_dev *dev, struct mlx5_fc *counter)
 308 {
 309         struct mlx5_fc_stats *fc_stats = &dev->priv.fc_stats;
 310
 311         if (!counter)
 312                 return;
 313
 314         if (counter->aging) {
 315                 llist_add(&counter->dellist, &fc_stats->dellist);
 316                 mod_delayed_work(fc_stats->wq, &fc_stats->work, 0);
 317                 return;
 318         }
 319
 320         mlx5_free_fc(dev, counter);
 321 }
 322 EXPORT_SYMBOL(mlx5_fc_destroy);
 323
 324 int mlx5_init_fc_stats(struct mlx5_core_dev *dev)
 325 {
 326         struct mlx5_fc_stats *fc_stats = &dev->priv.fc_stats;
 327
 328         spin_lock_init(&fc_stats->counters_idr_lock);
 329         idr_init(&fc_stats->counters_idr);
 330         INIT_LIST_HEAD(&fc_stats->counters);
 331         init_llist_head(&fc_stats->addlist);
 332         init_llist_head(&fc_stats->dellist);
 333
 334         fc_stats->wq = create_singlethread_workqueue("mlx5_fc");
 335         if (!fc_stats->wq)
 336                 return -ENOMEM;
 337
 338         fc_stats->sampling_interval = MLX5_FC_STATS_PERIOD;
 339         INIT_DELAYED_WORK(&fc_stats->work, mlx5_fc_stats_work);
 340
 341         return 0;
 342 }
 343
 344 void mlx5_cleanup_fc_stats(struct mlx5_core_dev *dev)
 345 {
 346         struct mlx5_fc_stats *fc_stats = &dev->priv.fc_stats;
 347         struct llist_node *tmplist;
 348         struct mlx5_fc *counter;
 349         struct mlx5_fc *tmp;
 350
 351         cancel_delayed_work_sync(&dev->priv.fc_stats.work);
 352         destroy_workqueue(dev->priv.fc_stats.wq);
 353         dev->priv.fc_stats.wq = NULL;
 354
 355         idr_destroy(&fc_stats->counters_idr);
 356
 357         tmplist = llist_del_all(&fc_stats->addlist);
 358         llist_for_each_entry_safe(counter, tmp, tmplist, addlist)
 359                 mlx5_free_fc(dev, counter);
 360
 361         list_for_each_entry_safe(counter, tmp, &fc_stats->counters, list)
 362                 mlx5_free_fc(dev, counter);
 363 }
 364
 365 int mlx5_fc_query(struct mlx5_core_dev *dev, struct mlx5_fc *counter,
 366                   u64 *packets, u64 *bytes)
 367 {
 368         return mlx5_cmd_fc_query(dev, counter->id, packets, bytes);
 369 }
 370 EXPORT_SYMBOL(mlx5_fc_query);
 371
 372 void mlx5_fc_query_cached(struct mlx5_fc *counter,
 373                           u64 *bytes, u64 *packets, u64 *lastuse)
 374 {
 375         struct mlx5_fc_cache c;
 376
 377         c = counter->cache;
 378
 379         *bytes = c.bytes - counter->lastbytes;
 380         *packets = c.packets - counter->lastpackets;
 381         *lastuse = c.lastuse;
 382
 383         counter->lastbytes = c.bytes;
 384         counter->lastpackets = c.packets;
 385 }
 386
 387 void mlx5_fc_queue_stats_work(struct mlx5_core_dev *dev,
 388                               struct delayed_work *dwork,
 389                               unsigned long delay)
 390 {
 391         struct mlx5_fc_stats *fc_stats = &dev->priv.fc_stats;
 392
 393         queue_delayed_work(fc_stats->wq, dwork, delay);
 394 }
 395
 396 void mlx5_fc_update_sampling_interval(struct mlx5_core_dev *dev,
 397                                       unsigned long interval)
 398 {
 399         struct mlx5_fc_stats *fc_stats = &dev->priv.fc_stats;
 400
 401         fc_stats->sampling_interval = min_t(unsigned long, interval,
 402                                             fc_stats->sampling_interval);
 403 }