1 /* 2 * This file is provided under a dual BSD/GPLv2 license. When using or 3 * redistributing this file, you may do so under either license. 4 * 5 * GPL LICENSE SUMMARY 6 * 7 * Copyright(c) 2012 Intel Corporation. All rights reserved. 8 * Copyright (C) 2015 EMC Corporation. All Rights Reserved. 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of version 2 of the GNU General Public License as 12 * published by the Free Software Foundation. 13 * 14 * BSD LICENSE 15 * 16 * Copyright(c) 2012 Intel Corporation. All rights reserved. 17 * Copyright (C) 2015 EMC Corporation. All Rights Reserved. 18 * 19 * Redistribution and use in source and binary forms, with or without 20 * modification, are permitted provided that the following conditions 21 * are met: 22 * 23 * * Redistributions of source code must retain the above copyright 24 * notice, this list of conditions and the following disclaimer. 25 * * Redistributions in binary form must reproduce the above copy 26 * notice, this list of conditions and the following disclaimer in 27 * the documentation and/or other materials provided with the 28 * distribution. 29 * * Neither the name of Intel Corporation nor the names of its 30 * contributors may be used to endorse or promote products derived 31 * from this software without specific prior written permission. 32 * 33 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 34 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 35 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 36 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 37 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 38 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 39 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 40 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 41 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 42 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 43 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 44 * 45 * PCIe NTB Network Linux driver 46 * 47 * Contact Information: 48 * Jon Mason <jon.mason@intel.com> 49 */ 50 #include <linux/etherdevice.h> 51 #include <linux/ethtool.h> 52 #include <linux/module.h> 53 #include <linux/pci.h> 54 #include <linux/ntb.h> 55 #include <linux/ntb_transport.h> 56 57 #define NTB_NETDEV_VER "0.7" 58 59 MODULE_DESCRIPTION(KBUILD_MODNAME); 60 MODULE_VERSION(NTB_NETDEV_VER); 61 MODULE_LICENSE("Dual BSD/GPL"); 62 MODULE_AUTHOR("Intel Corporation"); 63 64 /* Time in usecs for tx resource reaper */ 65 static unsigned int tx_time = 1; 66 67 /* Number of descriptors to free before resuming tx */ 68 static unsigned int tx_start = 10; 69 70 /* Number of descriptors still available before stop upper layer tx */ 71 static unsigned int tx_stop = 5; 72 73 struct ntb_netdev { 74 struct pci_dev *pdev; 75 struct net_device *ndev; 76 struct ntb_transport_qp *qp; 77 struct timer_list tx_timer; 78 }; 79 80 #define NTB_TX_TIMEOUT_MS 1000 81 #define NTB_RXQ_SIZE 100 82 83 static void ntb_netdev_event_handler(void *data, int link_is_up) 84 { 85 struct net_device *ndev = data; 86 struct ntb_netdev *dev = netdev_priv(ndev); 87 88 netdev_dbg(ndev, "Event %x, Link %x\n", link_is_up, 89 ntb_transport_link_query(dev->qp)); 90 91 if (link_is_up) { 92 if (ntb_transport_link_query(dev->qp)) 93 netif_carrier_on(ndev); 94 } else { 95 netif_carrier_off(ndev); 96 } 97 } 98 99 static void ntb_netdev_rx_handler(struct ntb_transport_qp *qp, void *qp_data, 100 void *data, int len) 101 { 102 struct net_device *ndev = qp_data; 103 struct sk_buff *skb; 104 int rc; 105 106 skb = data; 107 if (!skb) 108 return; 109 110 netdev_dbg(ndev, "%s: %d byte payload received\n", __func__, len); 111 112 if (len < 0) { 113 ndev->stats.rx_errors++; 114 ndev->stats.rx_length_errors++; 115 goto enqueue_again; 116 } 117 118 skb_put(skb, len); 119 skb->protocol = eth_type_trans(skb, ndev); 120 skb->ip_summed = CHECKSUM_NONE; 121 122 if (netif_rx(skb) == NET_RX_DROP) { 123 ndev->stats.rx_errors++; 124 ndev->stats.rx_dropped++; 125 } else { 126 ndev->stats.rx_packets++; 127 ndev->stats.rx_bytes += len; 128 } 129 130 skb = netdev_alloc_skb(ndev, ndev->mtu + ETH_HLEN); 131 if (!skb) { 132 ndev->stats.rx_errors++; 133 ndev->stats.rx_frame_errors++; 134 return; 135 } 136 137 enqueue_again: 138 rc = ntb_transport_rx_enqueue(qp, skb, skb->data, ndev->mtu + ETH_HLEN); 139 if (rc) { 140 dev_kfree_skb(skb); 141 ndev->stats.rx_errors++; 142 ndev->stats.rx_fifo_errors++; 143 } 144 } 145 146 static int __ntb_netdev_maybe_stop_tx(struct net_device *netdev, 147 struct ntb_transport_qp *qp, int size) 148 { 149 struct ntb_netdev *dev = netdev_priv(netdev); 150 151 netif_stop_queue(netdev); 152 /* Make sure to see the latest value of ntb_transport_tx_free_entry() 153 * since the queue was last started. 154 */ 155 smp_mb(); 156 157 if (likely(ntb_transport_tx_free_entry(qp) < size)) { 158 mod_timer(&dev->tx_timer, jiffies + usecs_to_jiffies(tx_time)); 159 return -EBUSY; 160 } 161 162 netif_start_queue(netdev); 163 return 0; 164 } 165 166 static int ntb_netdev_maybe_stop_tx(struct net_device *ndev, 167 struct ntb_transport_qp *qp, int size) 168 { 169 if (netif_queue_stopped(ndev) || 170 (ntb_transport_tx_free_entry(qp) >= size)) 171 return 0; 172 173 return __ntb_netdev_maybe_stop_tx(ndev, qp, size); 174 } 175 176 static void ntb_netdev_tx_handler(struct ntb_transport_qp *qp, void *qp_data, 177 void *data, int len) 178 { 179 struct net_device *ndev = qp_data; 180 struct sk_buff *skb; 181 struct ntb_netdev *dev = netdev_priv(ndev); 182 183 skb = data; 184 if (!skb || !ndev) 185 return; 186 187 if (len > 0) { 188 ndev->stats.tx_packets++; 189 ndev->stats.tx_bytes += skb->len; 190 } else { 191 ndev->stats.tx_errors++; 192 ndev->stats.tx_aborted_errors++; 193 } 194 195 dev_kfree_skb(skb); 196 197 if (ntb_transport_tx_free_entry(dev->qp) >= tx_start) { 198 /* Make sure anybody stopping the queue after this sees the new 199 * value of ntb_transport_tx_free_entry() 200 */ 201 smp_mb(); 202 if (netif_queue_stopped(ndev)) 203 netif_wake_queue(ndev); 204 } 205 } 206 207 static netdev_tx_t ntb_netdev_start_xmit(struct sk_buff *skb, 208 struct net_device *ndev) 209 { 210 struct ntb_netdev *dev = netdev_priv(ndev); 211 int rc; 212 213 ntb_netdev_maybe_stop_tx(ndev, dev->qp, tx_stop); 214 215 rc = ntb_transport_tx_enqueue(dev->qp, skb, skb->data, skb->len); 216 if (rc) 217 goto err; 218 219 /* check for next submit */ 220 ntb_netdev_maybe_stop_tx(ndev, dev->qp, tx_stop); 221 222 return NETDEV_TX_OK; 223 224 err: 225 ndev->stats.tx_dropped++; 226 ndev->stats.tx_errors++; 227 return NETDEV_TX_BUSY; 228 } 229 230 static void ntb_netdev_tx_timer(struct timer_list *t) 231 { 232 struct ntb_netdev *dev = from_timer(dev, t, tx_timer); 233 struct net_device *ndev = dev->ndev; 234 235 if (ntb_transport_tx_free_entry(dev->qp) < tx_stop) { 236 mod_timer(&dev->tx_timer, jiffies + usecs_to_jiffies(tx_time)); 237 } else { 238 /* Make sure anybody stopping the queue after this sees the new 239 * value of ntb_transport_tx_free_entry() 240 */ 241 smp_mb(); 242 if (netif_queue_stopped(ndev)) 243 netif_wake_queue(ndev); 244 } 245 } 246 247 static int ntb_netdev_open(struct net_device *ndev) 248 { 249 struct ntb_netdev *dev = netdev_priv(ndev); 250 struct sk_buff *skb; 251 int rc, i, len; 252 253 /* Add some empty rx bufs */ 254 for (i = 0; i < NTB_RXQ_SIZE; i++) { 255 skb = netdev_alloc_skb(ndev, ndev->mtu + ETH_HLEN); 256 if (!skb) { 257 rc = -ENOMEM; 258 goto err; 259 } 260 261 rc = ntb_transport_rx_enqueue(dev->qp, skb, skb->data, 262 ndev->mtu + ETH_HLEN); 263 if (rc) { 264 dev_kfree_skb(skb); 265 goto err; 266 } 267 } 268 269 timer_setup(&dev->tx_timer, ntb_netdev_tx_timer, 0); 270 271 netif_carrier_off(ndev); 272 ntb_transport_link_up(dev->qp); 273 netif_start_queue(ndev); 274 275 return 0; 276 277 err: 278 while ((skb = ntb_transport_rx_remove(dev->qp, &len))) 279 dev_kfree_skb(skb); 280 return rc; 281 } 282 283 static int ntb_netdev_close(struct net_device *ndev) 284 { 285 struct ntb_netdev *dev = netdev_priv(ndev); 286 struct sk_buff *skb; 287 int len; 288 289 ntb_transport_link_down(dev->qp); 290 291 while ((skb = ntb_transport_rx_remove(dev->qp, &len))) 292 dev_kfree_skb(skb); 293 294 del_timer_sync(&dev->tx_timer); 295 296 return 0; 297 } 298 299 static int ntb_netdev_change_mtu(struct net_device *ndev, int new_mtu) 300 { 301 struct ntb_netdev *dev = netdev_priv(ndev); 302 struct sk_buff *skb; 303 int len, rc; 304 305 if (new_mtu > ntb_transport_max_size(dev->qp) - ETH_HLEN) 306 return -EINVAL; 307 308 if (!netif_running(ndev)) { 309 ndev->mtu = new_mtu; 310 return 0; 311 } 312 313 /* Bring down the link and dispose of posted rx entries */ 314 ntb_transport_link_down(dev->qp); 315 316 if (ndev->mtu < new_mtu) { 317 int i; 318 319 for (i = 0; (skb = ntb_transport_rx_remove(dev->qp, &len)); i++) 320 dev_kfree_skb(skb); 321 322 for (; i; i--) { 323 skb = netdev_alloc_skb(ndev, new_mtu + ETH_HLEN); 324 if (!skb) { 325 rc = -ENOMEM; 326 goto err; 327 } 328 329 rc = ntb_transport_rx_enqueue(dev->qp, skb, skb->data, 330 new_mtu + ETH_HLEN); 331 if (rc) { 332 dev_kfree_skb(skb); 333 goto err; 334 } 335 } 336 } 337 338 ndev->mtu = new_mtu; 339 340 ntb_transport_link_up(dev->qp); 341 342 return 0; 343 344 err: 345 ntb_transport_link_down(dev->qp); 346 347 while ((skb = ntb_transport_rx_remove(dev->qp, &len))) 348 dev_kfree_skb(skb); 349 350 netdev_err(ndev, "Error changing MTU, device inoperable\n"); 351 return rc; 352 } 353 354 static const struct net_device_ops ntb_netdev_ops = { 355 .ndo_open = ntb_netdev_open, 356 .ndo_stop = ntb_netdev_close, 357 .ndo_start_xmit = ntb_netdev_start_xmit, 358 .ndo_change_mtu = ntb_netdev_change_mtu, 359 .ndo_set_mac_address = eth_mac_addr, 360 }; 361 362 static void ntb_get_drvinfo(struct net_device *ndev, 363 struct ethtool_drvinfo *info) 364 { 365 struct ntb_netdev *dev = netdev_priv(ndev); 366 367 strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver)); 368 strlcpy(info->version, NTB_NETDEV_VER, sizeof(info->version)); 369 strlcpy(info->bus_info, pci_name(dev->pdev), sizeof(info->bus_info)); 370 } 371 372 static int ntb_get_link_ksettings(struct net_device *dev, 373 struct ethtool_link_ksettings *cmd) 374 { 375 ethtool_link_ksettings_zero_link_mode(cmd, supported); 376 ethtool_link_ksettings_add_link_mode(cmd, supported, Backplane); 377 ethtool_link_ksettings_zero_link_mode(cmd, advertising); 378 ethtool_link_ksettings_add_link_mode(cmd, advertising, Backplane); 379 380 cmd->base.speed = SPEED_UNKNOWN; 381 cmd->base.duplex = DUPLEX_FULL; 382 cmd->base.port = PORT_OTHER; 383 cmd->base.phy_address = 0; 384 cmd->base.autoneg = AUTONEG_ENABLE; 385 386 return 0; 387 } 388 389 static const struct ethtool_ops ntb_ethtool_ops = { 390 .get_drvinfo = ntb_get_drvinfo, 391 .get_link = ethtool_op_get_link, 392 .get_link_ksettings = ntb_get_link_ksettings, 393 }; 394 395 static const struct ntb_queue_handlers ntb_netdev_handlers = { 396 .tx_handler = ntb_netdev_tx_handler, 397 .rx_handler = ntb_netdev_rx_handler, 398 .event_handler = ntb_netdev_event_handler, 399 }; 400 401 static int ntb_netdev_probe(struct device *client_dev) 402 { 403 struct ntb_dev *ntb; 404 struct net_device *ndev; 405 struct pci_dev *pdev; 406 struct ntb_netdev *dev; 407 int rc; 408 409 ntb = dev_ntb(client_dev->parent); 410 pdev = ntb->pdev; 411 if (!pdev) 412 return -ENODEV; 413 414 ndev = alloc_etherdev(sizeof(*dev)); 415 if (!ndev) 416 return -ENOMEM; 417 418 SET_NETDEV_DEV(ndev, client_dev); 419 420 dev = netdev_priv(ndev); 421 dev->ndev = ndev; 422 dev->pdev = pdev; 423 ndev->features = NETIF_F_HIGHDMA; 424 425 ndev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 426 427 ndev->hw_features = ndev->features; 428 ndev->watchdog_timeo = msecs_to_jiffies(NTB_TX_TIMEOUT_MS); 429 430 eth_random_addr(ndev->perm_addr); 431 memcpy(ndev->dev_addr, ndev->perm_addr, ndev->addr_len); 432 433 ndev->netdev_ops = &ntb_netdev_ops; 434 ndev->ethtool_ops = &ntb_ethtool_ops; 435 436 ndev->min_mtu = 0; 437 ndev->max_mtu = ETH_MAX_MTU; 438 439 dev->qp = ntb_transport_create_queue(ndev, client_dev, 440 &ntb_netdev_handlers); 441 if (!dev->qp) { 442 rc = -EIO; 443 goto err; 444 } 445 446 ndev->mtu = ntb_transport_max_size(dev->qp) - ETH_HLEN; 447 448 rc = register_netdev(ndev); 449 if (rc) 450 goto err1; 451 452 dev_set_drvdata(client_dev, ndev); 453 dev_info(&pdev->dev, "%s created\n", ndev->name); 454 return 0; 455 456 err1: 457 ntb_transport_free_queue(dev->qp); 458 err: 459 free_netdev(ndev); 460 return rc; 461 } 462 463 static void ntb_netdev_remove(struct device *client_dev) 464 { 465 struct net_device *ndev = dev_get_drvdata(client_dev); 466 struct ntb_netdev *dev = netdev_priv(ndev); 467 468 unregister_netdev(ndev); 469 ntb_transport_free_queue(dev->qp); 470 free_netdev(ndev); 471 } 472 473 static struct ntb_transport_client ntb_netdev_client = { 474 .driver.name = KBUILD_MODNAME, 475 .driver.owner = THIS_MODULE, 476 .probe = ntb_netdev_probe, 477 .remove = ntb_netdev_remove, 478 }; 479 480 static int __init ntb_netdev_init_module(void) 481 { 482 int rc; 483 484 rc = ntb_transport_register_client_dev(KBUILD_MODNAME); 485 if (rc) 486 return rc; 487 return ntb_transport_register_client(&ntb_netdev_client); 488 } 489 module_init(ntb_netdev_init_module); 490 491 static void __exit ntb_netdev_exit_module(void) 492 { 493 ntb_transport_unregister_client(&ntb_netdev_client); 494 ntb_transport_unregister_client_dev(KBUILD_MODNAME); 495 } 496 module_exit(ntb_netdev_exit_module); 497