drivers/net/sfc/sfc_switch.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  *
   3  * Copyright(c) 2019-2020 Xilinx, Inc.
   4  * Copyright(c) 2019 Solarflare Communications Inc.
   5  *
   6  * This software was jointly developed between OKTET Labs (under contract
   7  * for Solarflare) and Solarflare Communications, Inc.
   8  */
   9
  10 #include <stdbool.h>
  11
  12 #include <rte_common.h>
  13 #include <rte_spinlock.h>
  14
  15 #include "efx.h"
  16
  17 #include "sfc.h"
  18 #include "sfc_log.h"
  19 #include "sfc_switch.h"
  20
  21 /**
  22  * Switch port registry entry.
  23  *
  24  * Drivers aware of RTE switch domains also have to maintain RTE switch
  25  * port IDs for RTE ethdev instances they operate. These IDs are supposed
  26  * to stand for physical interconnect entities, in example, PCIe functions.
  27  *
  28  * In terms of MAE, a physical interconnect entity can be referred to using
  29  * an MPORT selector, that is, a 32-bit value. RTE switch port IDs, in turn,
  30  * are 16-bit values, so indirect mapping has to be maintained:
  31  *
  32  * +--------------------+          +---------------------------------------+
  33  * | RTE switch port ID |  ------  |         MAE switch port entry         |
  34  * +--------------------+          |         ---------------------         |
  35  *                                 |                                       |
  36  *                                 | Entity (PCIe function) MPORT selector |
  37  *                                 |                   +                   |
  38  *                                 |  Port type (independent/representor)  |
  39  *                                 +---------------------------------------+
  40  *
  41  * This mapping comprises a port type to ensure that RTE switch port ID
  42  * of a represented entity and that of its representor are different in
  43  * the case when the entity gets plugged into DPDK and not into a guest.
  44  *
  45  * Entry data also comprises RTE ethdev's own MPORT. This value
  46  * coincides with the entity MPORT in the case of independent ports.
  47  * In the case of representors, this ID is not a selector and refers
  48  * to an allocatable object (that is, it's likely to change on RTE
  49  * ethdev replug). Flow API backend must use this value rather
  50  * than entity_mport to support flow rule action PORT_ID.
  51  */
  52 struct sfc_mae_switch_port {
  53         TAILQ_ENTRY(sfc_mae_switch_port)        switch_domain_ports;
  54
  55         /** RTE ethdev MPORT */
  56         efx_mport_sel_t                         ethdev_mport;
  57         /** RTE ethdev port ID */
  58         uint16_t                                ethdev_port_id;
  59
  60         /** Entity (PCIe function) MPORT selector */
  61         efx_mport_sel_t                         entity_mport;
  62         /** Port type (independent/representor) */
  63         enum sfc_mae_switch_port_type           type;
  64         /** RTE switch port ID */
  65         uint16_t                                id;
  66 };
  67
  68 TAILQ_HEAD(sfc_mae_switch_ports, sfc_mae_switch_port);
  69
  70 /**
  71  * Switch domain registry entry.
  72  *
  73  * Even if an RTE ethdev instance gets unplugged, the corresponding
  74  * entry in the switch port registry will not be removed because the
  75  * entity (PCIe function) MPORT is static and cannot change. If this
  76  * RTE ethdev gets plugged back, the entry will be reused, and
  77  * RTE switch port ID will be the same.
  78  */
  79 struct sfc_mae_switch_domain {
  80         TAILQ_ENTRY(sfc_mae_switch_domain)      entries;
  81
  82         /** HW switch ID */
  83         struct sfc_hw_switch_id                 *hw_switch_id;
  84         /** The number of ports in the switch port registry */
  85         unsigned int                            nb_ports;
  86         /** Switch port registry */
  87         struct sfc_mae_switch_ports             ports;
  88         /** RTE switch domain ID allocated for a group of devices */
  89         uint16_t                                id;
  90 };
  91
  92 TAILQ_HEAD(sfc_mae_switch_domains, sfc_mae_switch_domain);
  93
  94 /**
  95  * MAE representation of RTE switch infrastructure.
  96  *
  97  * It is possible that an RTE flow API client tries to insert a rule
  98  * referencing an RTE ethdev deployed on top of a different physical
  99  * device (it may belong to the same vendor or not). This particular
 100  * driver/engine cannot support this and has to turn down such rules.
 101  *
 102  * Technically, it's HW switch identifier which, if queried for each
 103  * RTE ethdev instance, indicates relationship between the instances.
 104  * In the meantime, RTE flow API clients also need to somehow figure
 105  * out relationship between RTE ethdev instances in advance.
 106  *
 107  * The concept of RTE switch domains resolves this issue. The driver
 108  * maintains a static list of switch domains which is easy to browse,
 109  * and each RTE ethdev fills RTE switch parameters in device
 110  * information structure which is made available to clients.
 111  *
 112  * Even if all RTE ethdev instances belonging to a switch domain get
 113  * unplugged, the corresponding entry in the switch domain registry
 114  * will not be removed because the corresponding HW switch exists
 115  * regardless of its ports being plugged to DPDK or kept aside.
 116  * If a port gets plugged back to DPDK, the corresponding
 117  * RTE ethdev will indicate the same RTE switch domain ID.
 118  */
 119 struct sfc_mae_switch {
 120         /** A lock to protect the whole structure */
 121         rte_spinlock_t                  lock;
 122         /** Switch domain registry */
 123         struct sfc_mae_switch_domains   domains;
 124 };
 125
 126 static struct sfc_mae_switch sfc_mae_switch = {
 127         .lock = RTE_SPINLOCK_INITIALIZER,
 128         .domains = TAILQ_HEAD_INITIALIZER(sfc_mae_switch.domains),
 129 };
 130
 131
 132 /* This function expects to be called only when the lock is held */
 133 static struct sfc_mae_switch_domain *
 134 sfc_mae_find_switch_domain_by_id(uint16_t switch_domain_id)
 135 {
 136         struct sfc_mae_switch_domain *domain;
 137
 138         SFC_ASSERT(rte_spinlock_is_locked(&sfc_mae_switch.lock));
 139
 140         TAILQ_FOREACH(domain, &sfc_mae_switch.domains, entries) {
 141                 if (domain->id == switch_domain_id)
 142                         return domain;
 143         }
 144
 145         return NULL;
 146 }
 147
 148 /* This function expects to be called only when the lock is held */
 149 static struct sfc_mae_switch_domain *
 150 sfc_mae_find_switch_domain_by_hw_switch_id(const struct sfc_hw_switch_id *id)
 151 {
 152         struct sfc_mae_switch_domain *domain;
 153
 154         SFC_ASSERT(rte_spinlock_is_locked(&sfc_mae_switch.lock));
 155
 156         TAILQ_FOREACH(domain, &sfc_mae_switch.domains, entries) {
 157                 if (sfc_hw_switch_ids_equal(domain->hw_switch_id, id))
 158                         return domain;
 159         }
 160
 161         return NULL;
 162 }
 163
 164 int
 165 sfc_mae_assign_switch_domain(struct sfc_adapter *sa,
 166                              uint16_t *switch_domain_id)
 167 {
 168         struct sfc_hw_switch_id *hw_switch_id;
 169         struct sfc_mae_switch_domain *domain;
 170         int rc;
 171
 172         rte_spinlock_lock(&sfc_mae_switch.lock);
 173
 174         rc = sfc_hw_switch_id_init(sa, &hw_switch_id);
 175         if (rc != 0)
 176                 goto fail_hw_switch_id_init;
 177
 178         domain = sfc_mae_find_switch_domain_by_hw_switch_id(hw_switch_id);
 179         if (domain != NULL) {
 180                 sfc_hw_switch_id_fini(sa, hw_switch_id);
 181                 goto done;
 182         }
 183
 184         domain = rte_zmalloc("sfc_mae_switch_domain", sizeof(*domain), 0);
 185         if (domain == NULL) {
 186                 rc = ENOMEM;
 187                 goto fail_mem_alloc;
 188         }
 189
 190         /*
 191          * This code belongs to driver init path, that is, negation is
 192          * done at the end of the path by sfc_eth_dev_init(). RTE APIs
 193          * negate error codes, so drop negation here.
 194          */
 195         rc = -rte_eth_switch_domain_alloc(&domain->id);
 196         if (rc != 0)
 197                 goto fail_domain_alloc;
 198
 199         domain->hw_switch_id = hw_switch_id;
 200
 201         TAILQ_INIT(&domain->ports);
 202
 203         TAILQ_INSERT_TAIL(&sfc_mae_switch.domains, domain, entries);
 204
 205 done:
 206         *switch_domain_id = domain->id;
 207
 208         rte_spinlock_unlock(&sfc_mae_switch.lock);
 209
 210         return 0;
 211
 212 fail_domain_alloc:
 213         rte_free(domain);
 214
 215 fail_mem_alloc:
 216         sfc_hw_switch_id_fini(sa, hw_switch_id);
 217         rte_spinlock_unlock(&sfc_mae_switch.lock);
 218
 219 fail_hw_switch_id_init:
 220         return rc;
 221 }
 222
 223 /* This function expects to be called only when the lock is held */
 224 static struct sfc_mae_switch_port *
 225 sfc_mae_find_switch_port_by_entity(const struct sfc_mae_switch_domain *domain,
 226                                    const efx_mport_sel_t *entity_mportp,
 227                                    enum sfc_mae_switch_port_type type)
 228 {
 229         struct sfc_mae_switch_port *port;
 230
 231         SFC_ASSERT(rte_spinlock_is_locked(&sfc_mae_switch.lock));
 232
 233         TAILQ_FOREACH(port, &domain->ports, switch_domain_ports) {
 234                 if (port->entity_mport.sel == entity_mportp->sel &&
 235                     port->type == type)
 236                         return port;
 237         }
 238
 239         return NULL;
 240 }
 241
 242 int
 243 sfc_mae_assign_switch_port(uint16_t switch_domain_id,
 244                            const struct sfc_mae_switch_port_request *req,
 245                            uint16_t *switch_port_id)
 246 {
 247         struct sfc_mae_switch_domain *domain;
 248         struct sfc_mae_switch_port *port;
 249         int rc;
 250
 251         rte_spinlock_lock(&sfc_mae_switch.lock);
 252
 253         domain = sfc_mae_find_switch_domain_by_id(switch_domain_id);
 254         if (domain == NULL) {
 255                 rc = EINVAL;
 256                 goto fail_find_switch_domain_by_id;
 257         }
 258
 259         port = sfc_mae_find_switch_port_by_entity(domain, req->entity_mportp,
 260                                                   req->type);
 261         if (port != NULL)
 262                 goto done;
 263
 264         port = rte_zmalloc("sfc_mae_switch_port", sizeof(*port), 0);
 265         if (port == NULL) {
 266                 rc = ENOMEM;
 267                 goto fail_mem_alloc;
 268         }
 269
 270         port->entity_mport.sel = req->entity_mportp->sel;
 271         port->type = req->type;
 272
 273         port->id = (domain->nb_ports++);
 274
 275         TAILQ_INSERT_TAIL(&domain->ports, port, switch_domain_ports);
 276
 277 done:
 278         port->ethdev_mport = *req->ethdev_mportp;
 279         port->ethdev_port_id = req->ethdev_port_id;
 280
 281         *switch_port_id = port->id;
 282
 283         rte_spinlock_unlock(&sfc_mae_switch.lock);
 284
 285         return 0;
 286
 287 fail_mem_alloc:
 288 fail_find_switch_domain_by_id:
 289         rte_spinlock_unlock(&sfc_mae_switch.lock);
 290         return rc;
 291 }
 292
 293 /* This function expects to be called only when the lock is held */
 294 static int
 295 sfc_mae_find_switch_port_by_ethdev(uint16_t switch_domain_id,
 296                                    uint16_t ethdev_port_id,
 297                                    efx_mport_sel_t *mport_sel)
 298 {
 299         struct sfc_mae_switch_domain *domain;
 300         struct sfc_mae_switch_port *port;
 301
 302         SFC_ASSERT(rte_spinlock_is_locked(&sfc_mae_switch.lock));
 303
 304         if (ethdev_port_id == RTE_MAX_ETHPORTS)
 305                 return EINVAL;
 306
 307         domain = sfc_mae_find_switch_domain_by_id(switch_domain_id);
 308         if (domain == NULL)
 309                 return EINVAL;
 310
 311         TAILQ_FOREACH(port, &domain->ports, switch_domain_ports) {
 312                 if (port->ethdev_port_id == ethdev_port_id) {
 313                         *mport_sel = port->ethdev_mport;
 314                         return 0;
 315                 }
 316         }
 317
 318         return ENOENT;
 319 }
 320
 321 int
 322 sfc_mae_switch_port_by_ethdev(uint16_t switch_domain_id,
 323                               uint16_t ethdev_port_id,
 324                               efx_mport_sel_t *mport_sel)
 325 {
 326         int rc;
 327
 328         rte_spinlock_lock(&sfc_mae_switch.lock);
 329         rc = sfc_mae_find_switch_port_by_ethdev(switch_domain_id,
 330                                                 ethdev_port_id, mport_sel);
 331         rte_spinlock_unlock(&sfc_mae_switch.lock);
 332
 333         return rc;
 334 }