drivers/net/ixgbe/ixgbe_dcb.c

   1 /*******************************************************************************
   2
   3   Intel 10 Gigabit PCI Express Linux driver
   4   Copyright(c) 1999 - 2011 Intel Corporation.
   5
   6   This program is free software; you can redistribute it and/or modify it
   7   under the terms and conditions of the GNU General Public License,
   8   version 2, as published by the Free Software Foundation.
   9
  10   This program is distributed in the hope it will be useful, but WITHOUT
  11   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13   more details.
  14
  15   You should have received a copy of the GNU General Public License along with
  16   this program; if not, write to the Free Software Foundation, Inc.,
  17   51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  18
  19   The full GNU General Public License is included in this distribution in
  20   the file called "COPYING".
  21
  22   Contact Information:
  23   Linux NICS <linux.nics@intel.com>
  24   e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
  25   Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
  26
  27 *******************************************************************************/
  28
  29
  30 #include "ixgbe.h"
  31 #include "ixgbe_type.h"
  32 #include "ixgbe_dcb.h"
  33 #include "ixgbe_dcb_82598.h"
  34 #include "ixgbe_dcb_82599.h"
  35
  36 /**
  37  * ixgbe_ieee_credits - This calculates the ieee traffic class
  38  * credits from the configured bandwidth percentages. Credits
  39  * are the smallest unit programmable into the underlying
  40  * hardware. The IEEE 802.1Qaz specification do not use bandwidth
  41  * groups so this is much simplified from the CEE case.
  42  */
  43 s32 ixgbe_ieee_credits(__u8 *bw, __u16 *refill, __u16 *max, int max_frame)
  44 {
  45         int min_percent = 100;
  46         int min_credit, multiplier;
  47         int i;
  48
  49         min_credit = ((max_frame / 2) + DCB_CREDIT_QUANTUM - 1) /
  50                         DCB_CREDIT_QUANTUM;
  51
  52         for (i = 0; i < MAX_TRAFFIC_CLASS; i++) {
  53                 if (bw[i] < min_percent && bw[i])
  54                         min_percent = bw[i];
  55         }
  56
  57         multiplier = (min_credit / min_percent) + 1;
  58
  59         /* Find out the hw credits for each TC */
  60         for (i = 0; i < MAX_TRAFFIC_CLASS; i++) {
  61                 int val = min(bw[i] * multiplier, MAX_CREDIT_REFILL);
  62
  63                 if (val < min_credit)
  64                         val = min_credit;
  65                 refill[i] = val;
  66
  67                 max[i] = bw[i] ? (bw[i] * MAX_CREDIT)/100 : min_credit;
  68         }
  69         return 0;
  70 }
  71
  72 /**
  73  * ixgbe_dcb_calculate_tc_credits - Calculates traffic class credits
  74  * @ixgbe_dcb_config: Struct containing DCB settings.
  75  * @direction: Configuring either Tx or Rx.
  76  *
  77  * This function calculates the credits allocated to each traffic class.
  78  * It should be called only after the rules are checked by
  79  * ixgbe_dcb_check_config().
  80  */
  81 s32 ixgbe_dcb_calculate_tc_credits(struct ixgbe_hw *hw,
  82                                    struct ixgbe_dcb_config *dcb_config,
  83                                    int max_frame, u8 direction)
  84 {
  85         struct tc_bw_alloc *p;
  86         int min_credit;
  87         int min_multiplier;
  88         int min_percent = 100;
  89         s32 ret_val = 0;
  90         /* Initialization values default for Tx settings */
  91         u32 credit_refill       = 0;
  92         u32 credit_max          = 0;
  93         u16 link_percentage     = 0;
  94         u8  bw_percent          = 0;
  95         u8  i;
  96
  97         if (dcb_config == NULL) {
  98                 ret_val = DCB_ERR_CONFIG;
  99                 goto out;
 100         }
 101
 102         min_credit = ((max_frame / 2) + DCB_CREDIT_QUANTUM - 1) /
 103                         DCB_CREDIT_QUANTUM;
 104
 105         /* Find smallest link percentage */
 106         for (i = 0; i < MAX_TRAFFIC_CLASS; i++) {
 107                 p = &dcb_config->tc_config[i].path[direction];
 108                 bw_percent = dcb_config->bw_percentage[direction][p->bwg_id];
 109                 link_percentage = p->bwg_percent;
 110
 111                 link_percentage = (link_percentage * bw_percent) / 100;
 112
 113                 if (link_percentage && link_percentage < min_percent)
 114                         min_percent = link_percentage;
 115         }
 116
 117         /*
 118          * The ratio between traffic classes will control the bandwidth
 119          * percentages seen on the wire. To calculate this ratio we use
 120          * a multiplier. It is required that the refill credits must be
 121          * larger than the max frame size so here we find the smallest
 122          * multiplier that will allow all bandwidth percentages to be
 123          * greater than the max frame size.
 124          */
 125         min_multiplier = (min_credit / min_percent) + 1;
 126
 127         /* Find out the link percentage for each TC first */
 128         for (i = 0; i < MAX_TRAFFIC_CLASS; i++) {
 129                 p = &dcb_config->tc_config[i].path[direction];
 130                 bw_percent = dcb_config->bw_percentage[direction][p->bwg_id];
 131
 132                 link_percentage = p->bwg_percent;
 133                 /* Must be careful of integer division for very small nums */
 134                 link_percentage = (link_percentage * bw_percent) / 100;
 135                 if (p->bwg_percent > 0 && link_percentage == 0)
 136                         link_percentage = 1;
 137
 138                 /* Save link_percentage for reference */
 139                 p->link_percent = (u8)link_percentage;
 140
 141                 /* Calculate credit refill ratio using multiplier */
 142                 credit_refill = min(link_percentage * min_multiplier,
 143                                     MAX_CREDIT_REFILL);
 144                 p->data_credits_refill = (u16)credit_refill;
 145
 146                 /* Calculate maximum credit for the TC */
 147                 credit_max = (link_percentage * MAX_CREDIT) / 100;
 148
 149                 /*
 150                  * Adjustment based on rule checking, if the percentage
 151                  * of a TC is too small, the maximum credit may not be
 152                  * enough to send out a jumbo frame in data plane arbitration.
 153                  */
 154                 if (credit_max && (credit_max < min_credit))
 155                         credit_max = min_credit;
 156
 157                 if (direction == DCB_TX_CONFIG) {
 158                         /*
 159                          * Adjustment based on rule checking, if the
 160                          * percentage of a TC is too small, the maximum
 161                          * credit may not be enough to send out a TSO
 162                          * packet in descriptor plane arbitration.
 163                          */
 164                         if ((hw->mac.type == ixgbe_mac_82598EB) &&
 165                             credit_max &&
 166                             (credit_max < MINIMUM_CREDIT_FOR_TSO))
 167                                 credit_max = MINIMUM_CREDIT_FOR_TSO;
 168
 169                         dcb_config->tc_config[i].desc_credits_max =
 170                                 (u16)credit_max;
 171                 }
 172
 173                 p->data_credits_max = (u16)credit_max;
 174         }
 175
 176 out:
 177         return ret_val;
 178 }
 179
 180 void ixgbe_dcb_unpack_pfc(struct ixgbe_dcb_config *cfg, u8 *pfc_en)
 181 {
 182         int i;
 183
 184         *pfc_en = 0;
 185         for (i = 0; i < MAX_TRAFFIC_CLASS; i++)
 186                 *pfc_en |= (cfg->tc_config[i].dcb_pfc & 0xF) << i;
 187 }
 188
 189 void ixgbe_dcb_unpack_refill(struct ixgbe_dcb_config *cfg, int direction,
 190                              u16 *refill)
 191 {
 192         struct tc_bw_alloc *p;
 193         int i;
 194
 195         for (i = 0; i < MAX_TRAFFIC_CLASS; i++) {
 196                 p = &cfg->tc_config[i].path[direction];
 197                 refill[i] = p->data_credits_refill;
 198         }
 199 }
 200
 201 void ixgbe_dcb_unpack_max(struct ixgbe_dcb_config *cfg, u16 *max)
 202 {
 203         int i;
 204
 205         for (i = 0; i < MAX_TRAFFIC_CLASS; i++)
 206                 max[i] = cfg->tc_config[i].desc_credits_max;
 207 }
 208
 209 void ixgbe_dcb_unpack_bwgid(struct ixgbe_dcb_config *cfg, int direction,
 210                             u8 *bwgid)
 211 {
 212         struct tc_bw_alloc *p;
 213         int i;
 214
 215         for (i = 0; i < MAX_TRAFFIC_CLASS; i++) {
 216                 p = &cfg->tc_config[i].path[direction];
 217                 bwgid[i] = p->bwg_id;
 218         }
 219 }
 220
 221 void ixgbe_dcb_unpack_prio(struct ixgbe_dcb_config *cfg, int direction,
 222                             u8 *ptype)
 223 {
 224         struct tc_bw_alloc *p;
 225         int i;
 226
 227         for (i = 0; i < MAX_TRAFFIC_CLASS; i++) {
 228                 p = &cfg->tc_config[i].path[direction];
 229                 ptype[i] = p->prio_type;
 230         }
 231 }
 232
 233 /**
 234  * ixgbe_dcb_hw_config - Config and enable DCB
 235  * @hw: pointer to hardware structure
 236  * @dcb_config: pointer to ixgbe_dcb_config structure
 237  *
 238  * Configure dcb settings and enable dcb mode.
 239  */
 240 s32 ixgbe_dcb_hw_config(struct ixgbe_hw *hw,
 241                         struct ixgbe_dcb_config *dcb_config)
 242 {
 243         s32 ret = 0;
 244         u8 pfc_en;
 245         u8 ptype[MAX_TRAFFIC_CLASS];
 246         u8 bwgid[MAX_TRAFFIC_CLASS];
 247         u16 refill[MAX_TRAFFIC_CLASS];
 248         u16 max[MAX_TRAFFIC_CLASS];
 249         /* CEE does not define a priority to tc mapping so map 1:1 */
 250         u8 prio_tc[MAX_TRAFFIC_CLASS] = {0, 1, 2, 3, 4, 5, 6, 7};
 251
 252         /* Unpack CEE standard containers */
 253         ixgbe_dcb_unpack_pfc(dcb_config, &pfc_en);
 254         ixgbe_dcb_unpack_refill(dcb_config, DCB_TX_CONFIG, refill);
 255         ixgbe_dcb_unpack_max(dcb_config, max);
 256         ixgbe_dcb_unpack_bwgid(dcb_config, DCB_TX_CONFIG, bwgid);
 257         ixgbe_dcb_unpack_prio(dcb_config, DCB_TX_CONFIG, ptype);
 258
 259         switch (hw->mac.type) {
 260         case ixgbe_mac_82598EB:
 261                 ret = ixgbe_dcb_hw_config_82598(hw, pfc_en, refill, max,
 262                                                 bwgid, ptype);
 263                 break;
 264         case ixgbe_mac_82599EB:
 265         case ixgbe_mac_X540:
 266                 ret = ixgbe_dcb_hw_config_82599(hw, pfc_en, refill, max,
 267                                                 bwgid, ptype, prio_tc);
 268                 break;
 269         default:
 270                 break;
 271         }
 272         return ret;
 273 }
 274
 275 /* Helper routines to abstract HW specifics from DCB netlink ops */
 276 s32 ixgbe_dcb_hw_pfc_config(struct ixgbe_hw *hw, u8 pfc_en)
 277 {
 278         int ret = -EINVAL;
 279
 280         switch (hw->mac.type) {
 281         case ixgbe_mac_82598EB:
 282                 ret = ixgbe_dcb_config_pfc_82598(hw, pfc_en);
 283                 break;
 284         case ixgbe_mac_82599EB:
 285         case ixgbe_mac_X540:
 286                 ret = ixgbe_dcb_config_pfc_82599(hw, pfc_en);
 287                 break;
 288         default:
 289                 break;
 290         }
 291         return ret;
 292 }
 293
 294 s32 ixgbe_dcb_hw_ets_config(struct ixgbe_hw *hw,
 295                             u16 *refill, u16 *max, u8 *bwg_id,
 296                             u8 *prio_type, u8 *prio_tc)
 297 {
 298         switch (hw->mac.type) {
 299         case ixgbe_mac_82598EB:
 300                 ixgbe_dcb_config_rx_arbiter_82598(hw, refill, max,
 301                                                         prio_type);
 302                 ixgbe_dcb_config_tx_desc_arbiter_82598(hw, refill, max,
 303                                                              bwg_id, prio_type);
 304                 ixgbe_dcb_config_tx_data_arbiter_82598(hw, refill, max,
 305                                                              bwg_id, prio_type);
 306                 break;
 307         case ixgbe_mac_82599EB:
 308         case ixgbe_mac_X540:
 309                 ixgbe_dcb_config_rx_arbiter_82599(hw, refill, max,
 310                                                   bwg_id, prio_type, prio_tc);
 311                 ixgbe_dcb_config_tx_desc_arbiter_82599(hw, refill, max,
 312                                                        bwg_id, prio_type);
 313                 ixgbe_dcb_config_tx_data_arbiter_82599(hw, refill, max, bwg_id,
 314                                                        prio_type, prio_tc);
 315                 break;
 316         default:
 317                 break;
 318         }
 319         return 0;
 320 }