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

   1 /*
   2  * Copyright (c) 2013-2016, 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/kernel.h>
  34 #include <linux/module.h>
  35 #include <linux/mlx5/driver.h>
  36 #include <linux/mlx5/cmd.h>
  37 #include "mlx5_core.h"
  38
  39 /* Finds an entry where we can register the given rate
  40  * If the rate already exists, return the entry where it is registered,
  41  * otherwise return the first available entry.
  42  * If the table is full, return NULL
  43  */
  44 static struct mlx5_rl_entry *find_rl_entry(struct mlx5_rl_table *table,
  45                                            u32 rate)
  46 {
  47         struct mlx5_rl_entry *ret_entry = NULL;
  48         bool empty_found = false;
  49         int i;
  50
  51         for (i = 0; i < table->max_size; i++) {
  52                 if (table->rl_entry[i].rate == rate)
  53                         return &table->rl_entry[i];
  54                 if (!empty_found && !table->rl_entry[i].rate) {
  55                         empty_found = true;
  56                         ret_entry = &table->rl_entry[i];
  57                 }
  58         }
  59
  60         return ret_entry;
  61 }
  62
  63 static int mlx5_set_rate_limit_cmd(struct mlx5_core_dev *dev,
  64                                    u32 rate, u16 index)
  65 {
  66         u32 in[MLX5_ST_SZ_DW(set_rate_limit_in)];
  67         u32 out[MLX5_ST_SZ_DW(set_rate_limit_out)];
  68
  69         memset(in, 0, sizeof(in));
  70         memset(out, 0, sizeof(out));
  71
  72         MLX5_SET(set_rate_limit_in, in, opcode,
  73                  MLX5_CMD_OP_SET_RATE_LIMIT);
  74         MLX5_SET(set_rate_limit_in, in, rate_limit_index, index);
  75         MLX5_SET(set_rate_limit_in, in, rate_limit, rate);
  76
  77         return mlx5_cmd_exec_check_status(dev, in, sizeof(in),
  78                                           out, sizeof(out));
  79 }
  80
  81 bool mlx5_rl_is_in_range(struct mlx5_core_dev *dev, u32 rate)
  82 {
  83         struct mlx5_rl_table *table = &dev->priv.rl_table;
  84
  85         return (rate <= table->max_rate && rate >= table->min_rate);
  86 }
  87 EXPORT_SYMBOL(mlx5_rl_is_in_range);
  88
  89 int mlx5_rl_add_rate(struct mlx5_core_dev *dev, u32 rate, u16 *index)
  90 {
  91         struct mlx5_rl_table *table = &dev->priv.rl_table;
  92         struct mlx5_rl_entry *entry;
  93         int err = 0;
  94
  95         mutex_lock(&table->rl_lock);
  96
  97         if (!rate || !mlx5_rl_is_in_range(dev, rate)) {
  98                 mlx5_core_err(dev, "Invalid rate: %u, should be %u to %u\n",
  99                               rate, table->min_rate, table->max_rate);
 100                 err = -EINVAL;
 101                 goto out;
 102         }
 103
 104         entry = find_rl_entry(table, rate);
 105         if (!entry) {
 106                 mlx5_core_err(dev, "Max number of %u rates reached\n",
 107                               table->max_size);
 108                 err = -ENOSPC;
 109                 goto out;
 110         }
 111         if (entry->refcount) {
 112                 /* rate already configured */
 113                 entry->refcount++;
 114         } else {
 115                 /* new rate limit */
 116                 err = mlx5_set_rate_limit_cmd(dev, rate, entry->index);
 117                 if (err) {
 118                         mlx5_core_err(dev, "Failed configuring rate: %u (%d)\n",
 119                                       rate, err);
 120                         goto out;
 121                 }
 122                 entry->rate = rate;
 123                 entry->refcount = 1;
 124         }
 125         *index = entry->index;
 126
 127 out:
 128         mutex_unlock(&table->rl_lock);
 129         return err;
 130 }
 131 EXPORT_SYMBOL(mlx5_rl_add_rate);
 132
 133 void mlx5_rl_remove_rate(struct mlx5_core_dev *dev, u32 rate)
 134 {
 135         struct mlx5_rl_table *table = &dev->priv.rl_table;
 136         struct mlx5_rl_entry *entry = NULL;
 137
 138         /* 0 is a reserved value for unlimited rate */
 139         if (rate == 0)
 140                 return;
 141
 142         mutex_lock(&table->rl_lock);
 143         entry = find_rl_entry(table, rate);
 144         if (!entry || !entry->refcount) {
 145                 mlx5_core_warn(dev, "Rate %u is not configured\n", rate);
 146                 goto out;
 147         }
 148
 149         entry->refcount--;
 150         if (!entry->refcount) {
 151                 /* need to remove rate */
 152                 mlx5_set_rate_limit_cmd(dev, 0, entry->index);
 153                 entry->rate = 0;
 154         }
 155
 156 out:
 157         mutex_unlock(&table->rl_lock);
 158 }
 159 EXPORT_SYMBOL(mlx5_rl_remove_rate);
 160
 161 int mlx5_init_rl_table(struct mlx5_core_dev *dev)
 162 {
 163         struct mlx5_rl_table *table = &dev->priv.rl_table;
 164         int i;
 165
 166         mutex_init(&table->rl_lock);
 167         if (!MLX5_CAP_GEN(dev, qos) || !MLX5_CAP_QOS(dev, packet_pacing)) {
 168                 table->max_size = 0;
 169                 return 0;
 170         }
 171
 172         /* First entry is reserved for unlimited rate */
 173         table->max_size = MLX5_CAP_QOS(dev, packet_pacing_rate_table_size) - 1;
 174         table->max_rate = MLX5_CAP_QOS(dev, packet_pacing_max_rate);
 175         table->min_rate = MLX5_CAP_QOS(dev, packet_pacing_min_rate);
 176
 177         table->rl_entry = kcalloc(table->max_size, sizeof(struct mlx5_rl_entry),
 178                                   GFP_KERNEL);
 179         if (!table->rl_entry)
 180                 return -ENOMEM;
 181
 182         /* The index represents the index in HW rate limit table
 183          * Index 0 is reserved for unlimited rate
 184          */
 185         for (i = 0; i < table->max_size; i++)
 186                 table->rl_entry[i].index = i + 1;
 187
 188         /* Index 0 is reserved */
 189         mlx5_core_info(dev, "Rate limit: %u rates are supported, range: %uMbps to %uMbps\n",
 190                        table->max_size,
 191                        table->min_rate >> 10,
 192                        table->max_rate >> 10);
 193
 194         return 0;
 195 }
 196
 197 void mlx5_cleanup_rl_table(struct mlx5_core_dev *dev)
 198 {
 199         struct mlx5_rl_table *table = &dev->priv.rl_table;
 200         int i;
 201
 202         /* Clear all configured rates */
 203         for (i = 0; i < table->max_size; i++)
 204                 if (table->rl_entry[i].rate)
 205                         mlx5_set_rate_limit_cmd(dev, 0,
 206                                                 table->rl_entry[i].index);
 207
 208         kfree(dev->priv.rl_table.rl_entry);
 209 }