drivers/net/ethernet/mellanox/mlx5/core/en/port_buffer.c

   1 /*
   2  * Copyright (c) 2018, 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 #include "port_buffer.h"
  33
  34 int mlx5e_port_query_buffer(struct mlx5e_priv *priv,
  35                             struct mlx5e_port_buffer *port_buffer)
  36 {
  37         u16 port_buff_cell_sz = priv->dcbx.port_buff_cell_sz;
  38         struct mlx5_core_dev *mdev = priv->mdev;
  39         int sz = MLX5_ST_SZ_BYTES(pbmc_reg);
  40         u32 total_used = 0;
  41         void *buffer;
  42         void *out;
  43         int err;
  44         int i;
  45
  46         out = kzalloc(sz, GFP_KERNEL);
  47         if (!out)
  48                 return -ENOMEM;
  49
  50         err = mlx5e_port_query_pbmc(mdev, out);
  51         if (err)
  52                 goto out;
  53
  54         for (i = 0; i < MLX5E_MAX_BUFFER; i++) {
  55                 buffer = MLX5_ADDR_OF(pbmc_reg, out, buffer[i]);
  56                 port_buffer->buffer[i].lossy =
  57                         MLX5_GET(bufferx_reg, buffer, lossy);
  58                 port_buffer->buffer[i].epsb =
  59                         MLX5_GET(bufferx_reg, buffer, epsb);
  60                 port_buffer->buffer[i].size =
  61                         MLX5_GET(bufferx_reg, buffer, size) * port_buff_cell_sz;
  62                 port_buffer->buffer[i].xon =
  63                         MLX5_GET(bufferx_reg, buffer, xon_threshold) * port_buff_cell_sz;
  64                 port_buffer->buffer[i].xoff =
  65                         MLX5_GET(bufferx_reg, buffer, xoff_threshold) * port_buff_cell_sz;
  66                 total_used += port_buffer->buffer[i].size;
  67
  68                 mlx5e_dbg(HW, priv, "buffer %d: size=%d, xon=%d, xoff=%d, epsb=%d, lossy=%d\n", i,
  69                           port_buffer->buffer[i].size,
  70                           port_buffer->buffer[i].xon,
  71                           port_buffer->buffer[i].xoff,
  72                           port_buffer->buffer[i].epsb,
  73                           port_buffer->buffer[i].lossy);
  74         }
  75
  76         port_buffer->port_buffer_size =
  77                 MLX5_GET(pbmc_reg, out, port_buffer_size) * port_buff_cell_sz;
  78         port_buffer->spare_buffer_size =
  79                 port_buffer->port_buffer_size - total_used;
  80
  81         mlx5e_dbg(HW, priv, "total buffer size=%d, spare buffer size=%d\n",
  82                   port_buffer->port_buffer_size,
  83                   port_buffer->spare_buffer_size);
  84 out:
  85         kfree(out);
  86         return err;
  87 }
  88
  89 static int port_set_buffer(struct mlx5e_priv *priv,
  90                            struct mlx5e_port_buffer *port_buffer)
  91 {
  92         u16 port_buff_cell_sz = priv->dcbx.port_buff_cell_sz;
  93         struct mlx5_core_dev *mdev = priv->mdev;
  94         int sz = MLX5_ST_SZ_BYTES(pbmc_reg);
  95         void *in;
  96         int err;
  97         int i;
  98
  99         in = kzalloc(sz, GFP_KERNEL);
 100         if (!in)
 101                 return -ENOMEM;
 102
 103         err = mlx5e_port_query_pbmc(mdev, in);
 104         if (err)
 105                 goto out;
 106
 107         for (i = 0; i < MLX5E_MAX_BUFFER; i++) {
 108                 void *buffer = MLX5_ADDR_OF(pbmc_reg, in, buffer[i]);
 109                 u64 size = port_buffer->buffer[i].size;
 110                 u64 xoff = port_buffer->buffer[i].xoff;
 111                 u64 xon = port_buffer->buffer[i].xon;
 112
 113                 do_div(size, port_buff_cell_sz);
 114                 do_div(xoff, port_buff_cell_sz);
 115                 do_div(xon, port_buff_cell_sz);
 116                 MLX5_SET(bufferx_reg, buffer, size, size);
 117                 MLX5_SET(bufferx_reg, buffer, lossy, port_buffer->buffer[i].lossy);
 118                 MLX5_SET(bufferx_reg, buffer, xoff_threshold, xoff);
 119                 MLX5_SET(bufferx_reg, buffer, xon_threshold, xon);
 120         }
 121
 122         err = mlx5e_port_set_pbmc(mdev, in);
 123 out:
 124         kfree(in);
 125         return err;
 126 }
 127
 128 /* xoff = ((301+2.16 * len [m]) * speed [Gbps] + 2.72 MTU [B])
 129  * minimum speed value is 40Gbps
 130  */
 131 static u32 calculate_xoff(struct mlx5e_priv *priv, unsigned int mtu)
 132 {
 133         u32 speed;
 134         u32 xoff;
 135         int err;
 136
 137         err = mlx5e_port_linkspeed(priv->mdev, &speed);
 138         if (err)
 139                 speed = SPEED_40000;
 140         speed = max_t(u32, speed, SPEED_40000);
 141
 142         xoff = (301 + 216 * priv->dcbx.cable_len / 100) * speed / 1000 + 272 * mtu / 100;
 143
 144         mlx5e_dbg(HW, priv, "%s: xoff=%d\n", __func__, xoff);
 145         return xoff;
 146 }
 147
 148 static int update_xoff_threshold(struct mlx5e_port_buffer *port_buffer,
 149                                  u32 xoff, unsigned int max_mtu, u16 port_buff_cell_sz)
 150 {
 151         int i;
 152
 153         for (i = 0; i < MLX5E_MAX_BUFFER; i++) {
 154                 if (port_buffer->buffer[i].lossy) {
 155                         port_buffer->buffer[i].xoff = 0;
 156                         port_buffer->buffer[i].xon  = 0;
 157                         continue;
 158                 }
 159
 160                 if (port_buffer->buffer[i].size <
 161                     (xoff + max_mtu + port_buff_cell_sz)) {
 162                         pr_err("buffer_size[%d]=%d is not enough for lossless buffer\n",
 163                                i, port_buffer->buffer[i].size);
 164                         return -ENOMEM;
 165                 }
 166
 167                 port_buffer->buffer[i].xoff = port_buffer->buffer[i].size - xoff;
 168                 port_buffer->buffer[i].xon  =
 169                         port_buffer->buffer[i].xoff - max_mtu;
 170         }
 171
 172         return 0;
 173 }
 174
 175 /**
 176  *      update_buffer_lossy     - Update buffer configuration based on pfc
 177  *      @max_mtu: netdev's max_mtu
 178  *      @pfc_en: <input> current pfc configuration
 179  *      @buffer: <input> current prio to buffer mapping
 180  *      @xoff:   <input> xoff value
 181  *      @port_buff_cell_sz: <input> port buffer cell_size
 182  *      @port_buffer: <output> port receive buffer configuration
 183  *      @change: <output>
 184  *
 185  *      Update buffer configuration based on pfc configuration and
 186  *      priority to buffer mapping.
 187  *      Buffer's lossy bit is changed to:
 188  *              lossless if there is at least one PFC enabled priority
 189  *              mapped to this buffer lossy if all priorities mapped to
 190  *              this buffer are PFC disabled
 191  *
 192  *      @return: 0 if no error,
 193  *      sets change to true if buffer configuration was modified.
 194  */
 195 static int update_buffer_lossy(unsigned int max_mtu,
 196                                u8 pfc_en, u8 *buffer, u32 xoff, u16 port_buff_cell_sz,
 197                                struct mlx5e_port_buffer *port_buffer,
 198                                bool *change)
 199 {
 200         bool changed = false;
 201         u8 lossy_count;
 202         u8 prio_count;
 203         u8 lossy;
 204         int prio;
 205         int err;
 206         int i;
 207
 208         for (i = 0; i < MLX5E_MAX_BUFFER; i++) {
 209                 prio_count = 0;
 210                 lossy_count = 0;
 211
 212                 for (prio = 0; prio < MLX5E_MAX_PRIORITY; prio++) {
 213                         if (buffer[prio] != i)
 214                                 continue;
 215
 216                         prio_count++;
 217                         lossy_count += !(pfc_en & (1 << prio));
 218                 }
 219
 220                 if (lossy_count == prio_count)
 221                         lossy = 1;
 222                 else /* lossy_count < prio_count */
 223                         lossy = 0;
 224
 225                 if (lossy != port_buffer->buffer[i].lossy) {
 226                         port_buffer->buffer[i].lossy = lossy;
 227                         changed = true;
 228                 }
 229         }
 230
 231         if (changed) {
 232                 err = update_xoff_threshold(port_buffer, xoff, max_mtu, port_buff_cell_sz);
 233                 if (err)
 234                         return err;
 235
 236                 *change = true;
 237         }
 238
 239         return 0;
 240 }
 241
 242 static int fill_pfc_en(struct mlx5_core_dev *mdev, u8 *pfc_en)
 243 {
 244         u32 g_rx_pause, g_tx_pause;
 245         int err;
 246
 247         err = mlx5_query_port_pause(mdev, &g_rx_pause, &g_tx_pause);
 248         if (err)
 249                 return err;
 250
 251         /* If global pause enabled, set all active buffers to lossless.
 252          * Otherwise, check PFC setting.
 253          */
 254         if (g_rx_pause || g_tx_pause)
 255                 *pfc_en = 0xff;
 256         else
 257                 err = mlx5_query_port_pfc(mdev, pfc_en, NULL);
 258
 259         return err;
 260 }
 261
 262 #define MINIMUM_MAX_MTU 9216
 263 int mlx5e_port_manual_buffer_config(struct mlx5e_priv *priv,
 264                                     u32 change, unsigned int mtu,
 265                                     struct ieee_pfc *pfc,
 266                                     u32 *buffer_size,
 267                                     u8 *prio2buffer)
 268 {
 269         u16 port_buff_cell_sz = priv->dcbx.port_buff_cell_sz;
 270         struct mlx5e_port_buffer port_buffer;
 271         u32 xoff = calculate_xoff(priv, mtu);
 272         bool update_prio2buffer = false;
 273         u8 buffer[MLX5E_MAX_PRIORITY];
 274         bool update_buffer = false;
 275         unsigned int max_mtu;
 276         u32 total_used = 0;
 277         u8 curr_pfc_en;
 278         int err;
 279         int i;
 280
 281         mlx5e_dbg(HW, priv, "%s: change=%x\n", __func__, change);
 282         max_mtu = max_t(unsigned int, priv->netdev->max_mtu, MINIMUM_MAX_MTU);
 283
 284         err = mlx5e_port_query_buffer(priv, &port_buffer);
 285         if (err)
 286                 return err;
 287
 288         if (change & MLX5E_PORT_BUFFER_CABLE_LEN) {
 289                 update_buffer = true;
 290                 err = update_xoff_threshold(&port_buffer, xoff, max_mtu, port_buff_cell_sz);
 291                 if (err)
 292                         return err;
 293         }
 294
 295         if (change & MLX5E_PORT_BUFFER_PFC) {
 296                 err = mlx5e_port_query_priority2buffer(priv->mdev, buffer);
 297                 if (err)
 298                         return err;
 299
 300                 err = update_buffer_lossy(max_mtu, pfc->pfc_en, buffer, xoff, port_buff_cell_sz,
 301                                           &port_buffer, &update_buffer);
 302                 if (err)
 303                         return err;
 304         }
 305
 306         if (change & MLX5E_PORT_BUFFER_PRIO2BUFFER) {
 307                 update_prio2buffer = true;
 308                 err = fill_pfc_en(priv->mdev, &curr_pfc_en);
 309                 if (err)
 310                         return err;
 311
 312                 err = update_buffer_lossy(max_mtu, curr_pfc_en, prio2buffer, port_buff_cell_sz,
 313                                           xoff, &port_buffer, &update_buffer);
 314                 if (err)
 315                         return err;
 316         }
 317
 318         if (change & MLX5E_PORT_BUFFER_SIZE) {
 319                 for (i = 0; i < MLX5E_MAX_BUFFER; i++) {
 320                         mlx5e_dbg(HW, priv, "%s: buffer[%d]=%d\n", __func__, i, buffer_size[i]);
 321                         if (!port_buffer.buffer[i].lossy && !buffer_size[i]) {
 322                                 mlx5e_dbg(HW, priv, "%s: lossless buffer[%d] size cannot be zero\n",
 323                                           __func__, i);
 324                                 return -EINVAL;
 325                         }
 326
 327                         port_buffer.buffer[i].size = buffer_size[i];
 328                         total_used += buffer_size[i];
 329                 }
 330
 331                 mlx5e_dbg(HW, priv, "%s: total buffer requested=%d\n", __func__, total_used);
 332
 333                 if (total_used > port_buffer.port_buffer_size)
 334                         return -EINVAL;
 335
 336                 update_buffer = true;
 337                 err = update_xoff_threshold(&port_buffer, xoff, max_mtu, port_buff_cell_sz);
 338                 if (err)
 339                         return err;
 340         }
 341
 342         /* Need to update buffer configuration if xoff value is changed */
 343         if (!update_buffer && xoff != priv->dcbx.xoff) {
 344                 update_buffer = true;
 345                 err = update_xoff_threshold(&port_buffer, xoff, max_mtu, port_buff_cell_sz);
 346                 if (err)
 347                         return err;
 348         }
 349         priv->dcbx.xoff = xoff;
 350
 351         /* Apply the settings */
 352         if (update_buffer) {
 353                 err = port_set_buffer(priv, &port_buffer);
 354                 if (err)
 355                         return err;
 356         }
 357
 358         if (update_prio2buffer)
 359                 err = mlx5e_port_set_priority2buffer(priv->mdev, prio2buffer);
 360
 361         return err;
 362 }