root/drivers/net/ethernet/intel/ixgbe/ixgbe_dcb.c

DEFINITIONS

1. ixgbe_ieee_credits
2. ixgbe_dcb_calculate_tc_credits
3. ixgbe_dcb_unpack_pfc
4. ixgbe_dcb_unpack_refill
5. ixgbe_dcb_unpack_max
6. ixgbe_dcb_unpack_bwgid
7. ixgbe_dcb_unpack_prio
8. ixgbe_dcb_get_tc_from_up
9. ixgbe_dcb_unpack_map
10. ixgbe_dcb_hw_config
11. ixgbe_dcb_hw_pfc_config
12. ixgbe_dcb_hw_ets
13. ixgbe_dcb_hw_ets_config
14. ixgbe_dcb_read_rtrup2tc_82599
15. ixgbe_dcb_read_rtrup2tc

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright(c) 1999 - 2018 Intel Corporation. */
   3 
   4 #include "ixgbe.h"
   5 #include "ixgbe_type.h"
   6 #include "ixgbe_dcb.h"
   7 #include "ixgbe_dcb_82598.h"
   8 #include "ixgbe_dcb_82599.h"
   9 
  10 /**
  11  * ixgbe_ieee_credits - This calculates the ieee traffic class
  12  * credits from the configured bandwidth percentages. Credits
  13  * are the smallest unit programmable into the underlying
  14  * hardware. The IEEE 802.1Qaz specification do not use bandwidth
  15  * groups so this is much simplified from the CEE case.
  16  * @bw: bandwidth index by traffic class
  17  * @refill: refill credits index by traffic class
  18  * @max: max credits by traffic class
  19  * @max_frame: maximum frame size
  20  */
  21 static s32 ixgbe_ieee_credits(__u8 *bw, __u16 *refill,
  22                               __u16 *max, int max_frame)
  23 {
  24         int min_percent = 100;
  25         int min_credit, multiplier;
  26         int i;
  27 
  28         min_credit = ((max_frame / 2) + DCB_CREDIT_QUANTUM - 1) /
  29                         DCB_CREDIT_QUANTUM;
  30 
  31         for (i = 0; i < MAX_TRAFFIC_CLASS; i++) {
  32                 if (bw[i] < min_percent && bw[i])
  33                         min_percent = bw[i];
  34         }
  35 
  36         multiplier = (min_credit / min_percent) + 1;
  37 
  38         /* Find out the hw credits for each TC */
  39         for (i = 0; i < MAX_TRAFFIC_CLASS; i++) {
  40                 int val = min(bw[i] * multiplier, MAX_CREDIT_REFILL);
  41 
  42                 if (val < min_credit)
  43                         val = min_credit;
  44                 refill[i] = val;
  45 
  46                 max[i] = bw[i] ? (bw[i] * MAX_CREDIT)/100 : min_credit;
  47         }
  48         return 0;
  49 }
  50 
  51 /**
  52  * ixgbe_dcb_calculate_tc_credits - Calculates traffic class credits
  53  * @hw: pointer to hardware structure
  54  * @dcb_config: Struct containing DCB settings
  55  * @max_frame: Maximum frame size
  56  * @direction: Configuring either Tx or Rx
  57  *
  58  * This function calculates the credits allocated to each traffic class.
  59  * It should be called only after the rules are checked by
  60  * ixgbe_dcb_check_config().
  61  */
  62 s32 ixgbe_dcb_calculate_tc_credits(struct ixgbe_hw *hw,
  63                                    struct ixgbe_dcb_config *dcb_config,
  64                                    int max_frame, u8 direction)
  65 {
  66         struct tc_bw_alloc *p;
  67         int min_credit;
  68         int min_multiplier;
  69         int min_percent = 100;
  70         /* Initialization values default for Tx settings */
  71         u32 credit_refill       = 0;
  72         u32 credit_max          = 0;
  73         u16 link_percentage     = 0;
  74         u8  bw_percent          = 0;
  75         u8  i;
  76 
  77         if (!dcb_config)
  78                 return DCB_ERR_CONFIG;
  79 
  80         min_credit = ((max_frame / 2) + DCB_CREDIT_QUANTUM - 1) /
  81                         DCB_CREDIT_QUANTUM;
  82 
  83         /* Find smallest link percentage */
  84         for (i = 0; i < MAX_TRAFFIC_CLASS; i++) {
  85                 p = &dcb_config->tc_config[i].path[direction];
  86                 bw_percent = dcb_config->bw_percentage[direction][p->bwg_id];
  87                 link_percentage = p->bwg_percent;
  88 
  89                 link_percentage = (link_percentage * bw_percent) / 100;
  90 
  91                 if (link_percentage && link_percentage < min_percent)
  92                         min_percent = link_percentage;
  93         }
  94 
  95         /*
  96          * The ratio between traffic classes will control the bandwidth
  97          * percentages seen on the wire. To calculate this ratio we use
  98          * a multiplier. It is required that the refill credits must be
  99          * larger than the max frame size so here we find the smallest
 100          * multiplier that will allow all bandwidth percentages to be
 101          * greater than the max frame size.
 102          */
 103         min_multiplier = (min_credit / min_percent) + 1;
 104 
 105         /* Find out the link percentage for each TC first */
 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 
 110                 link_percentage = p->bwg_percent;
 111                 /* Must be careful of integer division for very small nums */
 112                 link_percentage = (link_percentage * bw_percent) / 100;
 113                 if (p->bwg_percent > 0 && link_percentage == 0)
 114                         link_percentage = 1;
 115 
 116                 /* Save link_percentage for reference */
 117                 p->link_percent = (u8)link_percentage;
 118 
 119                 /* Calculate credit refill ratio using multiplier */
 120                 credit_refill = min(link_percentage * min_multiplier,
 121                                     MAX_CREDIT_REFILL);
 122 
 123                 /* Refill at least minimum credit */
 124                 if (credit_refill < min_credit)
 125                         credit_refill = min_credit;
 126 
 127                 p->data_credits_refill = (u16)credit_refill;
 128 
 129                 /* Calculate maximum credit for the TC */
 130                 credit_max = (link_percentage * MAX_CREDIT) / 100;
 131 
 132                 /*
 133                  * Adjustment based on rule checking, if the percentage
 134                  * of a TC is too small, the maximum credit may not be
 135                  * enough to send out a jumbo frame in data plane arbitration.
 136                  */
 137                 if (credit_max < min_credit)
 138                         credit_max = min_credit;
 139 
 140                 if (direction == DCB_TX_CONFIG) {
 141                         /*
 142                          * Adjustment based on rule checking, if the
 143                          * percentage of a TC is too small, the maximum
 144                          * credit may not be enough to send out a TSO
 145                          * packet in descriptor plane arbitration.
 146                          */
 147                         if ((hw->mac.type == ixgbe_mac_82598EB) &&
 148                             credit_max &&
 149                             (credit_max < MINIMUM_CREDIT_FOR_TSO))
 150                                 credit_max = MINIMUM_CREDIT_FOR_TSO;
 151 
 152                         dcb_config->tc_config[i].desc_credits_max =
 153                                 (u16)credit_max;
 154                 }
 155 
 156                 p->data_credits_max = (u16)credit_max;
 157         }
 158 
 159         return 0;
 160 }
 161 
 162 void ixgbe_dcb_unpack_pfc(struct ixgbe_dcb_config *cfg, u8 *pfc_en)
 163 {
 164         struct tc_configuration *tc_config = &cfg->tc_config[0];
 165         int tc;
 166 
 167         for (*pfc_en = 0, tc = 0; tc < MAX_TRAFFIC_CLASS; tc++) {
 168                 if (tc_config[tc].dcb_pfc != pfc_disabled)
 169                         *pfc_en |= BIT(tc);
 170         }
 171 }
 172 
 173 void ixgbe_dcb_unpack_refill(struct ixgbe_dcb_config *cfg, int direction,
 174                              u16 *refill)
 175 {
 176         struct tc_configuration *tc_config = &cfg->tc_config[0];
 177         int tc;
 178 
 179         for (tc = 0; tc < MAX_TRAFFIC_CLASS; tc++)
 180                 refill[tc] = tc_config[tc].path[direction].data_credits_refill;
 181 }
 182 
 183 void ixgbe_dcb_unpack_max(struct ixgbe_dcb_config *cfg, u16 *max)
 184 {
 185         struct tc_configuration *tc_config = &cfg->tc_config[0];
 186         int tc;
 187 
 188         for (tc = 0; tc < MAX_TRAFFIC_CLASS; tc++)
 189                 max[tc] = tc_config[tc].desc_credits_max;
 190 }
 191 
 192 void ixgbe_dcb_unpack_bwgid(struct ixgbe_dcb_config *cfg, int direction,
 193                             u8 *bwgid)
 194 {
 195         struct tc_configuration *tc_config = &cfg->tc_config[0];
 196         int tc;
 197 
 198         for (tc = 0; tc < MAX_TRAFFIC_CLASS; tc++)
 199                 bwgid[tc] = tc_config[tc].path[direction].bwg_id;
 200 }
 201 
 202 void ixgbe_dcb_unpack_prio(struct ixgbe_dcb_config *cfg, int direction,
 203                             u8 *ptype)
 204 {
 205         struct tc_configuration *tc_config = &cfg->tc_config[0];
 206         int tc;
 207 
 208         for (tc = 0; tc < MAX_TRAFFIC_CLASS; tc++)
 209                 ptype[tc] = tc_config[tc].path[direction].prio_type;
 210 }
 211 
 212 u8 ixgbe_dcb_get_tc_from_up(struct ixgbe_dcb_config *cfg, int direction, u8 up)
 213 {
 214         struct tc_configuration *tc_config = &cfg->tc_config[0];
 215         u8 prio_mask = BIT(up);
 216         u8 tc = cfg->num_tcs.pg_tcs;
 217 
 218         /* If tc is 0 then DCB is likely not enabled or supported */
 219         if (!tc)
 220                 return 0;
 221 
 222         /*
 223          * Test from maximum TC to 1 and report the first match we find.  If
 224          * we find no match we can assume that the TC is 0 since the TC must
 225          * be set for all user priorities
 226          */
 227         for (tc--; tc; tc--) {
 228                 if (prio_mask & tc_config[tc].path[direction].up_to_tc_bitmap)
 229                         break;
 230         }
 231 
 232         return tc;
 233 }
 234 
 235 void ixgbe_dcb_unpack_map(struct ixgbe_dcb_config *cfg, int direction, u8 *map)
 236 {
 237         u8 up;
 238 
 239         for (up = 0; up < MAX_USER_PRIORITY; up++)
 240                 map[up] = ixgbe_dcb_get_tc_from_up(cfg, direction, up);
 241 }
 242 
 243 /**
 244  * ixgbe_dcb_hw_config - Config and enable DCB
 245  * @hw: pointer to hardware structure
 246  * @dcb_config: pointer to ixgbe_dcb_config structure
 247  *
 248  * Configure dcb settings and enable dcb mode.
 249  */
 250 s32 ixgbe_dcb_hw_config(struct ixgbe_hw *hw,
 251                         struct ixgbe_dcb_config *dcb_config)
 252 {
 253         u8 pfc_en;
 254         u8 ptype[MAX_TRAFFIC_CLASS];
 255         u8 bwgid[MAX_TRAFFIC_CLASS];
 256         u8 prio_tc[MAX_TRAFFIC_CLASS];
 257         u16 refill[MAX_TRAFFIC_CLASS];
 258         u16 max[MAX_TRAFFIC_CLASS];
 259 
 260         /* Unpack CEE standard containers */
 261         ixgbe_dcb_unpack_pfc(dcb_config, &pfc_en);
 262         ixgbe_dcb_unpack_refill(dcb_config, DCB_TX_CONFIG, refill);
 263         ixgbe_dcb_unpack_max(dcb_config, max);
 264         ixgbe_dcb_unpack_bwgid(dcb_config, DCB_TX_CONFIG, bwgid);
 265         ixgbe_dcb_unpack_prio(dcb_config, DCB_TX_CONFIG, ptype);
 266         ixgbe_dcb_unpack_map(dcb_config, DCB_TX_CONFIG, prio_tc);
 267 
 268         switch (hw->mac.type) {
 269         case ixgbe_mac_82598EB:
 270                 return ixgbe_dcb_hw_config_82598(hw, pfc_en, refill, max,
 271                                                  bwgid, ptype);
 272         case ixgbe_mac_82599EB:
 273         case ixgbe_mac_X540:
 274         case ixgbe_mac_X550:
 275         case ixgbe_mac_X550EM_x:
 276         case ixgbe_mac_x550em_a:
 277                 return ixgbe_dcb_hw_config_82599(hw, pfc_en, refill, max,
 278                                                  bwgid, ptype, prio_tc);
 279         default:
 280                 break;
 281         }
 282         return 0;
 283 }
 284 
 285 /* Helper routines to abstract HW specifics from DCB netlink ops */
 286 s32 ixgbe_dcb_hw_pfc_config(struct ixgbe_hw *hw, u8 pfc_en, u8 *prio_tc)
 287 {
 288         switch (hw->mac.type) {
 289         case ixgbe_mac_82598EB:
 290                 return ixgbe_dcb_config_pfc_82598(hw, pfc_en);
 291         case ixgbe_mac_82599EB:
 292         case ixgbe_mac_X540:
 293         case ixgbe_mac_X550:
 294         case ixgbe_mac_X550EM_x:
 295         case ixgbe_mac_x550em_a:
 296                 return ixgbe_dcb_config_pfc_82599(hw, pfc_en, prio_tc);
 297         default:
 298                 break;
 299         }
 300         return -EINVAL;
 301 }
 302 
 303 s32 ixgbe_dcb_hw_ets(struct ixgbe_hw *hw, struct ieee_ets *ets, int max_frame)
 304 {
 305         __u16 refill[IEEE_8021QAZ_MAX_TCS], max[IEEE_8021QAZ_MAX_TCS];
 306         __u8 prio_type[IEEE_8021QAZ_MAX_TCS];
 307         int i;
 308 
 309         /* naively give each TC a bwg to map onto CEE hardware */
 310         __u8 bwg_id[IEEE_8021QAZ_MAX_TCS] = {0, 1, 2, 3, 4, 5, 6, 7};
 311 
 312         /* Map TSA onto CEE prio type */
 313         for (i = 0; i < IEEE_8021QAZ_MAX_TCS; i++) {
 314                 switch (ets->tc_tsa[i]) {
 315                 case IEEE_8021QAZ_TSA_STRICT:
 316                         prio_type[i] = 2;
 317                         break;
 318                 case IEEE_8021QAZ_TSA_ETS:
 319                         prio_type[i] = 0;
 320                         break;
 321                 default:
 322                         /* Hardware only supports priority strict or
 323                          * ETS transmission selection algorithms if
 324                          * we receive some other value from dcbnl
 325                          * throw an error
 326                          */
 327                         return -EINVAL;
 328                 }
 329         }
 330 
 331         ixgbe_ieee_credits(ets->tc_tx_bw, refill, max, max_frame);
 332         return ixgbe_dcb_hw_ets_config(hw, refill, max,
 333                                        bwg_id, prio_type, ets->prio_tc);
 334 }
 335 
 336 s32 ixgbe_dcb_hw_ets_config(struct ixgbe_hw *hw,
 337                             u16 *refill, u16 *max, u8 *bwg_id,
 338                             u8 *prio_type, u8 *prio_tc)
 339 {
 340         switch (hw->mac.type) {
 341         case ixgbe_mac_82598EB:
 342                 ixgbe_dcb_config_rx_arbiter_82598(hw, refill, max,
 343                                                         prio_type);
 344                 ixgbe_dcb_config_tx_desc_arbiter_82598(hw, refill, max,
 345                                                              bwg_id, prio_type);
 346                 ixgbe_dcb_config_tx_data_arbiter_82598(hw, refill, max,
 347                                                              bwg_id, prio_type);
 348                 break;
 349         case ixgbe_mac_82599EB:
 350         case ixgbe_mac_X540:
 351         case ixgbe_mac_X550:
 352         case ixgbe_mac_X550EM_x:
 353         case ixgbe_mac_x550em_a:
 354                 ixgbe_dcb_config_rx_arbiter_82599(hw, refill, max,
 355                                                   bwg_id, prio_type, prio_tc);
 356                 ixgbe_dcb_config_tx_desc_arbiter_82599(hw, refill, max,
 357                                                        bwg_id, prio_type);
 358                 ixgbe_dcb_config_tx_data_arbiter_82599(hw, refill, max, bwg_id,
 359                                                        prio_type, prio_tc);
 360                 break;
 361         default:
 362                 break;
 363         }
 364         return 0;
 365 }
 366 
 367 static void ixgbe_dcb_read_rtrup2tc_82599(struct ixgbe_hw *hw, u8 *map)
 368 {
 369         u32 reg, i;
 370 
 371         reg = IXGBE_READ_REG(hw, IXGBE_RTRUP2TC);
 372         for (i = 0; i < MAX_USER_PRIORITY; i++)
 373                 map[i] = IXGBE_RTRUP2TC_UP_MASK &
 374                         (reg >> (i * IXGBE_RTRUP2TC_UP_SHIFT));
 375 }
 376 
 377 void ixgbe_dcb_read_rtrup2tc(struct ixgbe_hw *hw, u8 *map)
 378 {
 379         switch (hw->mac.type) {
 380         case ixgbe_mac_82599EB:
 381         case ixgbe_mac_X540:
 382         case ixgbe_mac_X550:
 383         case ixgbe_mac_X550EM_x:
 384         case ixgbe_mac_x550em_a:
 385                 ixgbe_dcb_read_rtrup2tc_82599(hw, map);
 386                 break;
 387         default:
 388                 break;
 389         }
 390 }