drivers/ntb/ntb_transport.c

   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  *
   9  *   This program is free software; you can redistribute it and/or modify
  10  *   it under the terms of version 2 of the GNU General Public License as
  11  *   published by the Free Software Foundation.
  12  *
  13  *   BSD LICENSE
  14  *
  15  *   Copyright(c) 2012 Intel Corporation. All rights reserved.
  16  *
  17  *   Redistribution and use in source and binary forms, with or without
  18  *   modification, are permitted provided that the following conditions
  19  *   are met:
  20  *
  21  *     * Redistributions of source code must retain the above copyright
  22  *       notice, this list of conditions and the following disclaimer.
  23  *     * Redistributions in binary form must reproduce the above copy
  24  *       notice, this list of conditions and the following disclaimer in
  25  *       the documentation and/or other materials provided with the
  26  *       distribution.
  27  *     * Neither the name of Intel Corporation nor the names of its
  28  *       contributors may be used to endorse or promote products derived
  29  *       from this software without specific prior written permission.
  30  *
  31  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  32  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  33  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  34  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  35  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  36  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  37  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  38  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  39  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  40  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  41  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  42  *
  43  * Intel PCIe NTB Linux driver
  44  *
  45  * Contact Information:
  46  * Jon Mason <jon.mason@intel.com>
  47  */
  48 #include <linux/debugfs.h>
  49 #include <linux/delay.h>
  50 #include <linux/dma-mapping.h>
  51 #include <linux/errno.h>
  52 #include <linux/export.h>
  53 #include <linux/interrupt.h>
  54 #include <linux/module.h>
  55 #include <linux/pci.h>
  56 #include <linux/slab.h>
  57 #include <linux/types.h>
  58 #include <linux/ntb.h>
  59 #include "ntb_hw.h"
  60
  61 #define NTB_TRANSPORT_VERSION   3
  62
  63 static unsigned int transport_mtu = 0x401E;
  64 module_param(transport_mtu, uint, 0644);
  65 MODULE_PARM_DESC(transport_mtu, "Maximum size of NTB transport packets");
  66
  67 static unsigned char max_num_clients = 2;
  68 module_param(max_num_clients, byte, 0644);
  69 MODULE_PARM_DESC(max_num_clients, "Maximum number of NTB transport clients");
  70
  71 struct ntb_queue_entry {
  72         /* ntb_queue list reference */
  73         struct list_head entry;
  74         /* pointers to data to be transfered */
  75         void *cb_data;
  76         void *buf;
  77         unsigned int len;
  78         unsigned int flags;
  79 };
  80
  81 struct ntb_rx_info {
  82         unsigned int entry;
  83 };
  84
  85 struct ntb_transport_qp {
  86         struct ntb_transport *transport;
  87         struct ntb_device *ndev;
  88         void *cb_data;
  89
  90         bool client_ready;
  91         bool qp_link;
  92         u8 qp_num;      /* Only 64 QP's are allowed.  0-63 */
  93
  94         struct ntb_rx_info __iomem *rx_info;
  95         struct ntb_rx_info *remote_rx_info;
  96
  97         void (*tx_handler) (struct ntb_transport_qp *qp, void *qp_data,
  98                             void *data, int len);
  99         struct list_head tx_free_q;
 100         spinlock_t ntb_tx_free_q_lock;
 101         void __iomem *tx_mw;
 102         unsigned int tx_index;
 103         unsigned int tx_max_entry;
 104         unsigned int tx_max_frame;
 105
 106         void (*rx_handler) (struct ntb_transport_qp *qp, void *qp_data,
 107                             void *data, int len);
 108         struct tasklet_struct rx_work;
 109         struct list_head rx_pend_q;
 110         struct list_head rx_free_q;
 111         spinlock_t ntb_rx_pend_q_lock;
 112         spinlock_t ntb_rx_free_q_lock;
 113         void *rx_buff;
 114         unsigned int rx_index;
 115         unsigned int rx_max_entry;
 116         unsigned int rx_max_frame;
 117
 118         void (*event_handler) (void *data, int status);
 119         struct delayed_work link_work;
 120         struct work_struct link_cleanup;
 121
 122         struct dentry *debugfs_dir;
 123         struct dentry *debugfs_stats;
 124
 125         /* Stats */
 126         u64 rx_bytes;
 127         u64 rx_pkts;
 128         u64 rx_ring_empty;
 129         u64 rx_err_no_buf;
 130         u64 rx_err_oflow;
 131         u64 rx_err_ver;
 132         u64 tx_bytes;
 133         u64 tx_pkts;
 134         u64 tx_ring_full;
 135 };
 136
 137 struct ntb_transport_mw {
 138         size_t size;
 139         void *virt_addr;
 140         dma_addr_t dma_addr;
 141 };
 142
 143 struct ntb_transport_client_dev {
 144         struct list_head entry;
 145         struct device dev;
 146 };
 147
 148 struct ntb_transport {
 149         struct list_head entry;
 150         struct list_head client_devs;
 151
 152         struct ntb_device *ndev;
 153         struct ntb_transport_mw mw[NTB_NUM_MW];
 154         struct ntb_transport_qp *qps;
 155         unsigned int max_qps;
 156         unsigned long qp_bitmap;
 157         bool transport_link;
 158         struct delayed_work link_work;
 159         struct work_struct link_cleanup;
 160         struct dentry *debugfs_dir;
 161 };
 162
 163 enum {
 164         DESC_DONE_FLAG = 1 << 0,
 165         LINK_DOWN_FLAG = 1 << 1,
 166 };
 167
 168 struct ntb_payload_header {
 169         unsigned int ver;
 170         unsigned int len;
 171         unsigned int flags;
 172 };
 173
 174 enum {
 175         VERSION = 0,
 176         QP_LINKS,
 177         NUM_QPS,
 178         NUM_MWS,
 179         MW0_SZ_HIGH,
 180         MW0_SZ_LOW,
 181         MW1_SZ_HIGH,
 182         MW1_SZ_LOW,
 183         MAX_SPAD,
 184 };
 185
 186 #define QP_TO_MW(qp)            ((qp) % NTB_NUM_MW)
 187 #define NTB_QP_DEF_NUM_ENTRIES  100
 188 #define NTB_LINK_DOWN_TIMEOUT   10
 189
 190 static int ntb_match_bus(struct device *dev, struct device_driver *drv)
 191 {
 192         return !strncmp(dev_name(dev), drv->name, strlen(drv->name));
 193 }
 194
 195 static int ntb_client_probe(struct device *dev)
 196 {
 197         const struct ntb_client *drv = container_of(dev->driver,
 198                                                     struct ntb_client, driver);
 199         struct pci_dev *pdev = container_of(dev->parent, struct pci_dev, dev);
 200         int rc = -EINVAL;
 201
 202         get_device(dev);
 203         if (drv && drv->probe)
 204                 rc = drv->probe(pdev);
 205         if (rc)
 206                 put_device(dev);
 207
 208         return rc;
 209 }
 210
 211 static int ntb_client_remove(struct device *dev)
 212 {
 213         const struct ntb_client *drv = container_of(dev->driver,
 214                                                     struct ntb_client, driver);
 215         struct pci_dev *pdev = container_of(dev->parent, struct pci_dev, dev);
 216
 217         if (drv && drv->remove)
 218                 drv->remove(pdev);
 219
 220         put_device(dev);
 221
 222         return 0;
 223 }
 224
 225 static struct bus_type ntb_bus_type = {
 226         .name = "ntb_bus",
 227         .match = ntb_match_bus,
 228         .probe = ntb_client_probe,
 229         .remove = ntb_client_remove,
 230 };
 231
 232 static LIST_HEAD(ntb_transport_list);
 233
 234 static int ntb_bus_init(struct ntb_transport *nt)
 235 {
 236         if (list_empty(&ntb_transport_list)) {
 237                 int rc = bus_register(&ntb_bus_type);
 238                 if (rc)
 239                         return rc;
 240         }
 241
 242         list_add(&nt->entry, &ntb_transport_list);
 243
 244         return 0;
 245 }
 246
 247 static void ntb_bus_remove(struct ntb_transport *nt)
 248 {
 249         struct ntb_transport_client_dev *client_dev, *cd;
 250
 251         list_for_each_entry_safe(client_dev, cd, &nt->client_devs, entry) {
 252                 dev_err(client_dev->dev.parent, "%s still attached to bus, removing\n",
 253                         dev_name(&client_dev->dev));
 254                 list_del(&client_dev->entry);
 255                 device_unregister(&client_dev->dev);
 256         }
 257
 258         list_del(&nt->entry);
 259
 260         if (list_empty(&ntb_transport_list))
 261                 bus_unregister(&ntb_bus_type);
 262 }
 263
 264 static void ntb_client_release(struct device *dev)
 265 {
 266         struct ntb_transport_client_dev *client_dev;
 267         client_dev = container_of(dev, struct ntb_transport_client_dev, dev);
 268
 269         kfree(client_dev);
 270 }
 271
 272 /**
 273  * ntb_unregister_client_dev - Unregister NTB client device
 274  * @device_name: Name of NTB client device
 275  *
 276  * Unregister an NTB client device with the NTB transport layer
 277  */
 278 void ntb_unregister_client_dev(char *device_name)
 279 {
 280         struct ntb_transport_client_dev *client, *cd;
 281         struct ntb_transport *nt;
 282
 283         list_for_each_entry(nt, &ntb_transport_list, entry)
 284                 list_for_each_entry_safe(client, cd, &nt->client_devs, entry)
 285                         if (!strncmp(dev_name(&client->dev), device_name,
 286                                      strlen(device_name))) {
 287                                 list_del(&client->entry);
 288                                 device_unregister(&client->dev);
 289                         }
 290 }
 291 EXPORT_SYMBOL_GPL(ntb_unregister_client_dev);
 292
 293 /**
 294  * ntb_register_client_dev - Register NTB client device
 295  * @device_name: Name of NTB client device
 296  *
 297  * Register an NTB client device with the NTB transport layer
 298  */
 299 int ntb_register_client_dev(char *device_name)
 300 {
 301         struct ntb_transport_client_dev *client_dev;
 302         struct ntb_transport *nt;
 303         int rc, i = 0;
 304
 305         if (list_empty(&ntb_transport_list))
 306                 return -ENODEV;
 307
 308         list_for_each_entry(nt, &ntb_transport_list, entry) {
 309                 struct device *dev;
 310
 311                 client_dev = kzalloc(sizeof(struct ntb_transport_client_dev),
 312                                      GFP_KERNEL);
 313                 if (!client_dev) {
 314                         rc = -ENOMEM;
 315                         goto err;
 316                 }
 317
 318                 dev = &client_dev->dev;
 319
 320                 /* setup and register client devices */
 321                 dev_set_name(dev, "%s%d", device_name, i);
 322                 dev->bus = &ntb_bus_type;
 323                 dev->release = ntb_client_release;
 324                 dev->parent = &ntb_query_pdev(nt->ndev)->dev;
 325
 326                 rc = device_register(dev);
 327                 if (rc) {
 328                         kfree(client_dev);
 329                         goto err;
 330                 }
 331
 332                 list_add_tail(&client_dev->entry, &nt->client_devs);
 333                 i++;
 334         }
 335
 336         return 0;
 337
 338 err:
 339         ntb_unregister_client_dev(device_name);
 340
 341         return rc;
 342 }
 343 EXPORT_SYMBOL_GPL(ntb_register_client_dev);
 344
 345 /**
 346  * ntb_register_client - Register NTB client driver
 347  * @drv: NTB client driver to be registered
 348  *
 349  * Register an NTB client driver with the NTB transport layer
 350  *
 351  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 352  */
 353 int ntb_register_client(struct ntb_client *drv)
 354 {
 355         drv->driver.bus = &ntb_bus_type;
 356
 357         if (list_empty(&ntb_transport_list))
 358                 return -ENODEV;
 359
 360         return driver_register(&drv->driver);
 361 }
 362 EXPORT_SYMBOL_GPL(ntb_register_client);
 363
 364 /**
 365  * ntb_unregister_client - Unregister NTB client driver
 366  * @drv: NTB client driver to be unregistered
 367  *
 368  * Unregister an NTB client driver with the NTB transport layer
 369  *
 370  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 371  */
 372 void ntb_unregister_client(struct ntb_client *drv)
 373 {
 374         driver_unregister(&drv->driver);
 375 }
 376 EXPORT_SYMBOL_GPL(ntb_unregister_client);
 377
 378 static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count,
 379                             loff_t *offp)
 380 {
 381         struct ntb_transport_qp *qp;
 382         char *buf;
 383         ssize_t ret, out_offset, out_count;
 384
 385         out_count = 600;
 386
 387         buf = kmalloc(out_count, GFP_KERNEL);
 388         if (!buf)
 389                 return -ENOMEM;
 390
 391         qp = filp->private_data;
 392         out_offset = 0;
 393         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 394                                "NTB QP stats\n");
 395         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 396                                "rx_bytes - \t%llu\n", qp->rx_bytes);
 397         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 398                                "rx_pkts - \t%llu\n", qp->rx_pkts);
 399         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 400                                "rx_ring_empty - %llu\n", qp->rx_ring_empty);
 401         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 402                                "rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
 403         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 404                                "rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
 405         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 406                                "rx_err_ver - \t%llu\n", qp->rx_err_ver);
 407         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 408                                "rx_buff - \t%p\n", qp->rx_buff);
 409         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 410                                "rx_index - \t%u\n", qp->rx_index);
 411         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 412                                "rx_max_entry - \t%u\n", qp->rx_max_entry);
 413
 414         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 415                                "tx_bytes - \t%llu\n", qp->tx_bytes);
 416         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 417                                "tx_pkts - \t%llu\n", qp->tx_pkts);
 418         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 419                                "tx_ring_full - \t%llu\n", qp->tx_ring_full);
 420         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 421                                "tx_mw - \t%p\n", qp->tx_mw);
 422         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 423                                "tx_index - \t%u\n", qp->tx_index);
 424         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 425                                "tx_max_entry - \t%u\n", qp->tx_max_entry);
 426
 427         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 428                                "\nQP Link %s\n", (qp->qp_link == NTB_LINK_UP) ?
 429                                "Up" : "Down");
 430         if (out_offset > out_count)
 431                 out_offset = out_count;
 432
 433         ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
 434         kfree(buf);
 435         return ret;
 436 }
 437
 438 static const struct file_operations ntb_qp_debugfs_stats = {
 439         .owner = THIS_MODULE,
 440         .open = simple_open,
 441         .read = debugfs_read,
 442 };
 443
 444 static void ntb_list_add(spinlock_t *lock, struct list_head *entry,
 445                          struct list_head *list)
 446 {
 447         unsigned long flags;
 448
 449         spin_lock_irqsave(lock, flags);
 450         list_add_tail(entry, list);
 451         spin_unlock_irqrestore(lock, flags);
 452 }
 453
 454 static struct ntb_queue_entry *ntb_list_rm(spinlock_t *lock,
 455                                                 struct list_head *list)
 456 {
 457         struct ntb_queue_entry *entry;
 458         unsigned long flags;
 459
 460         spin_lock_irqsave(lock, flags);
 461         if (list_empty(list)) {
 462                 entry = NULL;
 463                 goto out;
 464         }
 465         entry = list_first_entry(list, struct ntb_queue_entry, entry);
 466         list_del(&entry->entry);
 467 out:
 468         spin_unlock_irqrestore(lock, flags);
 469
 470         return entry;
 471 }
 472
 473 static void ntb_transport_setup_qp_mw(struct ntb_transport *nt,
 474                                       unsigned int qp_num)
 475 {
 476         struct ntb_transport_qp *qp = &nt->qps[qp_num];
 477         unsigned int rx_size, num_qps_mw;
 478         u8 mw_num = QP_TO_MW(qp_num);
 479         unsigned int i;
 480
 481         WARN_ON(nt->mw[mw_num].virt_addr == NULL);
 482
 483         if (nt->max_qps % NTB_NUM_MW && mw_num < nt->max_qps % NTB_NUM_MW)
 484                 num_qps_mw = nt->max_qps / NTB_NUM_MW + 1;
 485         else
 486                 num_qps_mw = nt->max_qps / NTB_NUM_MW;
 487
 488         rx_size = (unsigned int) nt->mw[mw_num].size / num_qps_mw;
 489         qp->remote_rx_info = nt->mw[mw_num].virt_addr +
 490                              (qp_num / NTB_NUM_MW * rx_size);
 491         rx_size -= sizeof(struct ntb_rx_info);
 492
 493         qp->rx_buff = qp->remote_rx_info + 1;
 494         /* Due to housekeeping, there must be atleast 2 buffs */
 495         qp->rx_max_frame = min(transport_mtu, rx_size / 2);
 496         qp->rx_max_entry = rx_size / qp->rx_max_frame;
 497         qp->rx_index = 0;
 498
 499         qp->remote_rx_info->entry = qp->rx_max_entry - 1;
 500
 501         /* setup the hdr offsets with 0's */
 502         for (i = 0; i < qp->rx_max_entry; i++) {
 503                 void *offset = qp->rx_buff + qp->rx_max_frame * (i + 1) -
 504                                sizeof(struct ntb_payload_header);
 505                 memset(offset, 0, sizeof(struct ntb_payload_header));
 506         }
 507
 508         qp->rx_pkts = 0;
 509         qp->tx_pkts = 0;
 510         qp->tx_index = 0;
 511 }
 512
 513 static void ntb_free_mw(struct ntb_transport *nt, int num_mw)
 514 {
 515         struct ntb_transport_mw *mw = &nt->mw[num_mw];
 516         struct pci_dev *pdev = ntb_query_pdev(nt->ndev);
 517
 518         if (!mw->virt_addr)
 519                 return;
 520
 521         dma_free_coherent(&pdev->dev, mw->size, mw->virt_addr, mw->dma_addr);
 522         mw->virt_addr = NULL;
 523 }
 524
 525 static int ntb_set_mw(struct ntb_transport *nt, int num_mw, unsigned int size)
 526 {
 527         struct ntb_transport_mw *mw = &nt->mw[num_mw];
 528         struct pci_dev *pdev = ntb_query_pdev(nt->ndev);
 529
 530         /* No need to re-setup */
 531         if (mw->size == ALIGN(size, 4096))
 532                 return 0;
 533
 534         if (mw->size != 0)
 535                 ntb_free_mw(nt, num_mw);
 536
 537         /* Alloc memory for receiving data.  Must be 4k aligned */
 538         mw->size = ALIGN(size, 4096);
 539
 540         mw->virt_addr = dma_alloc_coherent(&pdev->dev, mw->size, &mw->dma_addr,
 541                                            GFP_KERNEL);
 542         if (!mw->virt_addr) {
 543                 mw->size = 0;
 544                 dev_err(&pdev->dev, "Unable to allocate MW buffer of size %d\n",
 545                        (int) mw->size);
 546                 return -ENOMEM;
 547         }
 548
 549         /* Notify HW the memory location of the receive buffer */
 550         ntb_set_mw_addr(nt->ndev, num_mw, mw->dma_addr);
 551
 552         return 0;
 553 }
 554
 555 static void ntb_qp_link_cleanup(struct work_struct *work)
 556 {
 557         struct ntb_transport_qp *qp = container_of(work,
 558                                                    struct ntb_transport_qp,
 559                                                    link_cleanup);
 560         struct ntb_transport *nt = qp->transport;
 561         struct pci_dev *pdev = ntb_query_pdev(nt->ndev);
 562
 563         if (qp->qp_link == NTB_LINK_DOWN) {
 564                 cancel_delayed_work_sync(&qp->link_work);
 565                 return;
 566         }
 567
 568         if (qp->event_handler)
 569                 qp->event_handler(qp->cb_data, NTB_LINK_DOWN);
 570
 571         dev_info(&pdev->dev, "qp %d: Link Down\n", qp->qp_num);
 572         qp->qp_link = NTB_LINK_DOWN;
 573
 574         if (nt->transport_link == NTB_LINK_UP)
 575                 schedule_delayed_work(&qp->link_work,
 576                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 577 }
 578
 579 static void ntb_qp_link_down(struct ntb_transport_qp *qp)
 580 {
 581         schedule_work(&qp->link_cleanup);
 582 }
 583
 584 static void ntb_transport_link_cleanup(struct work_struct *work)
 585 {
 586         struct ntb_transport *nt = container_of(work, struct ntb_transport,
 587                                                 link_cleanup);
 588         int i;
 589
 590         if (nt->transport_link == NTB_LINK_DOWN)
 591                 cancel_delayed_work_sync(&nt->link_work);
 592         else
 593                 nt->transport_link = NTB_LINK_DOWN;
 594
 595         /* Pass along the info to any clients */
 596         for (i = 0; i < nt->max_qps; i++)
 597                 if (!test_bit(i, &nt->qp_bitmap))
 598                         ntb_qp_link_down(&nt->qps[i]);
 599
 600         /* The scratchpad registers keep the values if the remote side
 601          * goes down, blast them now to give them a sane value the next
 602          * time they are accessed
 603          */
 604         for (i = 0; i < MAX_SPAD; i++)
 605                 ntb_write_local_spad(nt->ndev, i, 0);
 606 }
 607
 608 static void ntb_transport_event_callback(void *data, enum ntb_hw_event event)
 609 {
 610         struct ntb_transport *nt = data;
 611
 612         switch (event) {
 613         case NTB_EVENT_HW_LINK_UP:
 614                 schedule_delayed_work(&nt->link_work, 0);
 615                 break;
 616         case NTB_EVENT_HW_LINK_DOWN:
 617                 schedule_work(&nt->link_cleanup);
 618                 break;
 619         default:
 620                 BUG();
 621         }
 622 }
 623
 624 static void ntb_transport_link_work(struct work_struct *work)
 625 {
 626         struct ntb_transport *nt = container_of(work, struct ntb_transport,
 627                                                 link_work.work);
 628         struct ntb_device *ndev = nt->ndev;
 629         struct pci_dev *pdev = ntb_query_pdev(ndev);
 630         u32 val;
 631         int rc, i;
 632
 633         /* send the local info, in the opposite order of the way we read it */
 634         for (i = 0; i < NTB_NUM_MW; i++) {
 635                 rc = ntb_write_remote_spad(ndev, MW0_SZ_HIGH + (i * 2),
 636                                            ntb_get_mw_size(ndev, i) >> 32);
 637                 if (rc) {
 638                         dev_err(&pdev->dev, "Error writing %u to remote spad %d\n",
 639                                 (u32)(ntb_get_mw_size(ndev, i) >> 32),
 640                                 MW0_SZ_HIGH + (i * 2));
 641                         goto out;
 642                 }
 643
 644                 rc = ntb_write_remote_spad(ndev, MW0_SZ_LOW + (i * 2),
 645                                            (u32) ntb_get_mw_size(ndev, i));
 646                 if (rc) {
 647                         dev_err(&pdev->dev, "Error writing %u to remote spad %d\n",
 648                                 (u32) ntb_get_mw_size(ndev, i),
 649                                 MW0_SZ_LOW + (i * 2));
 650                         goto out;
 651                 }
 652         }
 653
 654         rc = ntb_write_remote_spad(ndev, NUM_MWS, NTB_NUM_MW);
 655         if (rc) {
 656                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
 657                         NTB_NUM_MW, NUM_MWS);
 658                 goto out;
 659         }
 660
 661         rc = ntb_write_remote_spad(ndev, NUM_QPS, nt->max_qps);
 662         if (rc) {
 663                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
 664                         nt->max_qps, NUM_QPS);
 665                 goto out;
 666         }
 667
 668         rc = ntb_write_remote_spad(ndev, VERSION, NTB_TRANSPORT_VERSION);
 669         if (rc) {
 670                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
 671                         NTB_TRANSPORT_VERSION, VERSION);
 672                 goto out;
 673         }
 674
 675         /* Query the remote side for its info */
 676         rc = ntb_read_remote_spad(ndev, VERSION, &val);
 677         if (rc) {
 678                 dev_err(&pdev->dev, "Error reading remote spad %d\n", VERSION);
 679                 goto out;
 680         }
 681
 682         if (val != NTB_TRANSPORT_VERSION)
 683                 goto out;
 684         dev_dbg(&pdev->dev, "Remote version = %d\n", val);
 685
 686         rc = ntb_read_remote_spad(ndev, NUM_QPS, &val);
 687         if (rc) {
 688                 dev_err(&pdev->dev, "Error reading remote spad %d\n", NUM_QPS);
 689                 goto out;
 690         }
 691
 692         if (val != nt->max_qps)
 693                 goto out;
 694         dev_dbg(&pdev->dev, "Remote max number of qps = %d\n", val);
 695
 696         rc = ntb_read_remote_spad(ndev, NUM_MWS, &val);
 697         if (rc) {
 698                 dev_err(&pdev->dev, "Error reading remote spad %d\n", NUM_MWS);
 699                 goto out;
 700         }
 701
 702         if (val != NTB_NUM_MW)
 703                 goto out;
 704         dev_dbg(&pdev->dev, "Remote number of mws = %d\n", val);
 705
 706         for (i = 0; i < NTB_NUM_MW; i++) {
 707                 u64 val64;
 708
 709                 rc = ntb_read_remote_spad(ndev, MW0_SZ_HIGH + (i * 2), &val);
 710                 if (rc) {
 711                         dev_err(&pdev->dev, "Error reading remote spad %d\n",
 712                                 MW0_SZ_HIGH + (i * 2));
 713                         goto out1;
 714                 }
 715
 716                 val64 = (u64) val << 32;
 717
 718                 rc = ntb_read_remote_spad(ndev, MW0_SZ_LOW + (i * 2), &val);
 719                 if (rc) {
 720                         dev_err(&pdev->dev, "Error reading remote spad %d\n",
 721                                 MW0_SZ_LOW + (i * 2));
 722                         goto out1;
 723                 }
 724
 725                 val64 |= val;
 726
 727                 dev_dbg(&pdev->dev, "Remote MW%d size = %llu\n", i, val64);
 728
 729                 rc = ntb_set_mw(nt, i, val64);
 730                 if (rc)
 731                         goto out1;
 732         }
 733
 734         nt->transport_link = NTB_LINK_UP;
 735
 736         for (i = 0; i < nt->max_qps; i++) {
 737                 struct ntb_transport_qp *qp = &nt->qps[i];
 738
 739                 ntb_transport_setup_qp_mw(nt, i);
 740
 741                 if (qp->client_ready == NTB_LINK_UP)
 742                         schedule_delayed_work(&qp->link_work, 0);
 743         }
 744
 745         return;
 746
 747 out1:
 748         for (i = 0; i < NTB_NUM_MW; i++)
 749                 ntb_free_mw(nt, i);
 750 out:
 751         if (ntb_hw_link_status(ndev))
 752                 schedule_delayed_work(&nt->link_work,
 753                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 754 }
 755
 756 static void ntb_qp_link_work(struct work_struct *work)
 757 {
 758         struct ntb_transport_qp *qp = container_of(work,
 759                                                    struct ntb_transport_qp,
 760                                                    link_work.work);
 761         struct pci_dev *pdev = ntb_query_pdev(qp->ndev);
 762         struct ntb_transport *nt = qp->transport;
 763         int rc, val;
 764
 765         WARN_ON(nt->transport_link != NTB_LINK_UP);
 766
 767         rc = ntb_read_local_spad(nt->ndev, QP_LINKS, &val);
 768         if (rc) {
 769                 dev_err(&pdev->dev, "Error reading spad %d\n", QP_LINKS);
 770                 return;
 771         }
 772
 773         rc = ntb_write_remote_spad(nt->ndev, QP_LINKS, val | 1 << qp->qp_num);
 774         if (rc)
 775                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
 776                         val | 1 << qp->qp_num, QP_LINKS);
 777
 778         /* query remote spad for qp ready bits */
 779         rc = ntb_read_remote_spad(nt->ndev, QP_LINKS, &val);
 780         if (rc)
 781                 dev_err(&pdev->dev, "Error reading remote spad %d\n", QP_LINKS);
 782
 783         dev_dbg(&pdev->dev, "Remote QP link status = %x\n", val);
 784
 785         /* See if the remote side is up */
 786         if (1 << qp->qp_num & val) {
 787                 qp->qp_link = NTB_LINK_UP;
 788
 789                 dev_info(&pdev->dev, "qp %d: Link Up\n", qp->qp_num);
 790                 if (qp->event_handler)
 791                         qp->event_handler(qp->cb_data, NTB_LINK_UP);
 792         } else if (nt->transport_link == NTB_LINK_UP)
 793                 schedule_delayed_work(&qp->link_work,
 794                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 795 }
 796
 797 static void ntb_transport_init_queue(struct ntb_transport *nt,
 798                                      unsigned int qp_num)
 799 {
 800         struct ntb_transport_qp *qp;
 801         unsigned int num_qps_mw, tx_size;
 802         u8 mw_num = QP_TO_MW(qp_num);
 803
 804         qp = &nt->qps[qp_num];
 805         qp->qp_num = qp_num;
 806         qp->transport = nt;
 807         qp->ndev = nt->ndev;
 808         qp->qp_link = NTB_LINK_DOWN;
 809         qp->client_ready = NTB_LINK_DOWN;
 810         qp->event_handler = NULL;
 811
 812         if (nt->max_qps % NTB_NUM_MW && mw_num < nt->max_qps % NTB_NUM_MW)
 813                 num_qps_mw = nt->max_qps / NTB_NUM_MW + 1;
 814         else
 815                 num_qps_mw = nt->max_qps / NTB_NUM_MW;
 816
 817         tx_size = (unsigned int) ntb_get_mw_size(qp->ndev, mw_num) / num_qps_mw;
 818         qp->rx_info = ntb_get_mw_vbase(nt->ndev, mw_num) +
 819                       (qp_num / NTB_NUM_MW * tx_size);
 820         tx_size -= sizeof(struct ntb_rx_info);
 821
 822         qp->tx_mw = qp->rx_info + 1;
 823         /* Due to housekeeping, there must be atleast 2 buffs */
 824         qp->tx_max_frame = min(transport_mtu, tx_size / 2);
 825         qp->tx_max_entry = tx_size / qp->tx_max_frame;
 826
 827         if (nt->debugfs_dir) {
 828                 char debugfs_name[4];
 829
 830                 snprintf(debugfs_name, 4, "qp%d", qp_num);
 831                 qp->debugfs_dir = debugfs_create_dir(debugfs_name,
 832                                                      nt->debugfs_dir);
 833
 834                 qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR,
 835                                                         qp->debugfs_dir, qp,
 836                                                         &ntb_qp_debugfs_stats);
 837         }
 838
 839         INIT_DELAYED_WORK(&qp->link_work, ntb_qp_link_work);
 840         INIT_WORK(&qp->link_cleanup, ntb_qp_link_cleanup);
 841
 842         spin_lock_init(&qp->ntb_rx_pend_q_lock);
 843         spin_lock_init(&qp->ntb_rx_free_q_lock);
 844         spin_lock_init(&qp->ntb_tx_free_q_lock);
 845
 846         INIT_LIST_HEAD(&qp->rx_pend_q);
 847         INIT_LIST_HEAD(&qp->rx_free_q);
 848         INIT_LIST_HEAD(&qp->tx_free_q);
 849 }
 850
 851 int ntb_transport_init(struct pci_dev *pdev)
 852 {
 853         struct ntb_transport *nt;
 854         int rc, i;
 855
 856         nt = kzalloc(sizeof(struct ntb_transport), GFP_KERNEL);
 857         if (!nt)
 858                 return -ENOMEM;
 859
 860         if (debugfs_initialized())
 861                 nt->debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
 862         else
 863                 nt->debugfs_dir = NULL;
 864
 865         nt->ndev = ntb_register_transport(pdev, nt);
 866         if (!nt->ndev) {
 867                 rc = -EIO;
 868                 goto err;
 869         }
 870
 871         nt->max_qps = min(nt->ndev->max_cbs, max_num_clients);
 872
 873         nt->qps = kcalloc(nt->max_qps, sizeof(struct ntb_transport_qp),
 874                           GFP_KERNEL);
 875         if (!nt->qps) {
 876                 rc = -ENOMEM;
 877                 goto err1;
 878         }
 879
 880         nt->qp_bitmap = ((u64) 1 << nt->max_qps) - 1;
 881
 882         for (i = 0; i < nt->max_qps; i++)
 883                 ntb_transport_init_queue(nt, i);
 884
 885         INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work);
 886         INIT_WORK(&nt->link_cleanup, ntb_transport_link_cleanup);
 887
 888         rc = ntb_register_event_callback(nt->ndev,
 889                                          ntb_transport_event_callback);
 890         if (rc)
 891                 goto err2;
 892
 893         INIT_LIST_HEAD(&nt->client_devs);
 894         rc = ntb_bus_init(nt);
 895         if (rc)
 896                 goto err3;
 897
 898         if (ntb_hw_link_status(nt->ndev))
 899                 schedule_delayed_work(&nt->link_work, 0);
 900
 901         return 0;
 902
 903 err3:
 904         ntb_unregister_event_callback(nt->ndev);
 905 err2:
 906         kfree(nt->qps);
 907 err1:
 908         ntb_unregister_transport(nt->ndev);
 909 err:
 910         debugfs_remove_recursive(nt->debugfs_dir);
 911         kfree(nt);
 912         return rc;
 913 }
 914
 915 void ntb_transport_free(void *transport)
 916 {
 917         struct ntb_transport *nt = transport;
 918         struct pci_dev *pdev;
 919         int i;
 920
 921         nt->transport_link = NTB_LINK_DOWN;
 922
 923         /* verify that all the qp's are freed */
 924         for (i = 0; i < nt->max_qps; i++)
 925                 if (!test_bit(i, &nt->qp_bitmap))
 926                         ntb_transport_free_queue(&nt->qps[i]);
 927
 928         ntb_bus_remove(nt);
 929
 930         cancel_delayed_work_sync(&nt->link_work);
 931
 932         debugfs_remove_recursive(nt->debugfs_dir);
 933
 934         ntb_unregister_event_callback(nt->ndev);
 935
 936         pdev = ntb_query_pdev(nt->ndev);
 937
 938         for (i = 0; i < NTB_NUM_MW; i++)
 939                 ntb_free_mw(nt, i);
 940
 941         kfree(nt->qps);
 942         ntb_unregister_transport(nt->ndev);
 943         kfree(nt);
 944 }
 945
 946 static void ntb_rx_copy_task(struct ntb_transport_qp *qp,
 947                              struct ntb_queue_entry *entry, void *offset)
 948 {
 949         void *cb_data = entry->cb_data;
 950         unsigned int len = entry->len;
 951
 952         memcpy(entry->buf, offset, entry->len);
 953
 954         ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry, &qp->rx_free_q);
 955
 956         if (qp->rx_handler && qp->client_ready == NTB_LINK_UP)
 957                 qp->rx_handler(qp, qp->cb_data, cb_data, len);
 958 }
 959
 960 static int ntb_process_rxc(struct ntb_transport_qp *qp)
 961 {
 962         struct ntb_payload_header *hdr;
 963         struct ntb_queue_entry *entry;
 964         void *offset;
 965
 966         offset = qp->rx_buff + qp->rx_max_frame * qp->rx_index;
 967         hdr = offset + qp->rx_max_frame - sizeof(struct ntb_payload_header);
 968
 969         entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q);
 970         if (!entry) {
 971                 dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
 972                         "no buffer - HDR ver %u, len %d, flags %x\n",
 973                         hdr->ver, hdr->len, hdr->flags);
 974                 qp->rx_err_no_buf++;
 975                 return -ENOMEM;
 976         }
 977
 978         if (!(hdr->flags & DESC_DONE_FLAG)) {
 979                 ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
 980                              &qp->rx_pend_q);
 981                 qp->rx_ring_empty++;
 982                 return -EAGAIN;
 983         }
 984
 985         if (hdr->ver != (u32) qp->rx_pkts) {
 986                 dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
 987                         "qp %d: version mismatch, expected %llu - got %u\n",
 988                         qp->qp_num, qp->rx_pkts, hdr->ver);
 989                 ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
 990                              &qp->rx_pend_q);
 991                 qp->rx_err_ver++;
 992                 return -EIO;
 993         }
 994
 995         if (hdr->flags & LINK_DOWN_FLAG) {
 996                 ntb_qp_link_down(qp);
 997
 998                 ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
 999                              &qp->rx_pend_q);
1000                 goto out;
1001         }
1002
1003         dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
1004                 "rx offset %u, ver %u - %d payload received, buf size %d\n",
1005                 qp->rx_index, hdr->ver, hdr->len, entry->len);
1006
1007         if (hdr->len <= entry->len) {
1008                 entry->len = hdr->len;
1009                 ntb_rx_copy_task(qp, entry, offset);
1010         } else {
1011                 ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
1012                              &qp->rx_pend_q);
1013
1014                 qp->rx_err_oflow++;
1015                 dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
1016                         "RX overflow! Wanted %d got %d\n",
1017                         hdr->len, entry->len);
1018         }
1019
1020         qp->rx_bytes += hdr->len;
1021         qp->rx_pkts++;
1022
1023 out:
1024         /* Ensure that the data is fully copied out before clearing the flag */
1025         wmb();
1026         hdr->flags = 0;
1027         iowrite32(qp->rx_index, &qp->rx_info->entry);
1028
1029         qp->rx_index++;
1030         qp->rx_index %= qp->rx_max_entry;
1031
1032         return 0;
1033 }
1034
1035 static void ntb_transport_rx(unsigned long data)
1036 {
1037         struct ntb_transport_qp *qp = (struct ntb_transport_qp *)data;
1038         int rc, i;
1039
1040         /* Limit the number of packets processed in a single interrupt to
1041          * provide fairness to others
1042          */
1043         for (i = 0; i < qp->rx_max_entry; i++) {
1044                 rc = ntb_process_rxc(qp);
1045                 if (rc)
1046                         break;
1047         }
1048 }
1049
1050 static void ntb_transport_rxc_db(void *data, int db_num)
1051 {
1052         struct ntb_transport_qp *qp = data;
1053
1054         dev_dbg(&ntb_query_pdev(qp->ndev)->dev, "%s: doorbell %d received\n",
1055                 __func__, db_num);
1056
1057         tasklet_schedule(&qp->rx_work);
1058 }
1059
1060 static void ntb_tx_copy_task(struct ntb_transport_qp *qp,
1061                              struct ntb_queue_entry *entry,
1062                              void __iomem *offset)
1063 {
1064         struct ntb_payload_header __iomem *hdr;
1065
1066         memcpy_toio(offset, entry->buf, entry->len);
1067
1068         hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
1069         iowrite32(entry->len, &hdr->len);
1070         iowrite32((u32) qp->tx_pkts, &hdr->ver);
1071
1072         /* Ensure that the data is fully copied out before setting the flag */
1073         wmb();
1074         iowrite32(entry->flags | DESC_DONE_FLAG, &hdr->flags);
1075
1076         ntb_ring_sdb(qp->ndev, qp->qp_num);
1077
1078         /* The entry length can only be zero if the packet is intended to be a
1079          * "link down" or similar.  Since no payload is being sent in these
1080          * cases, there is nothing to add to the completion queue.
1081          */
1082         if (entry->len > 0) {
1083                 qp->tx_bytes += entry->len;
1084
1085                 if (qp->tx_handler)
1086                         qp->tx_handler(qp, qp->cb_data, entry->cb_data,
1087                                        entry->len);
1088         }
1089
1090         ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q);
1091 }
1092
1093 static int ntb_process_tx(struct ntb_transport_qp *qp,
1094                           struct ntb_queue_entry *entry)
1095 {
1096         void __iomem *offset;
1097
1098         offset = qp->tx_mw + qp->tx_max_frame * qp->tx_index;
1099
1100         dev_dbg(&ntb_query_pdev(qp->ndev)->dev, "%lld - offset %p, tx %u, entry len %d flags %x buff %p\n",
1101                 qp->tx_pkts, offset, qp->tx_index, entry->len, entry->flags,
1102                 entry->buf);
1103         if (qp->tx_index == qp->remote_rx_info->entry) {
1104                 qp->tx_ring_full++;
1105                 return -EAGAIN;
1106         }
1107
1108         if (entry->len > qp->tx_max_frame - sizeof(struct ntb_payload_header)) {
1109                 if (qp->tx_handler)
1110                         qp->tx_handler(qp->cb_data, qp, NULL, -EIO);
1111
1112                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1113                              &qp->tx_free_q);
1114                 return 0;
1115         }
1116
1117         ntb_tx_copy_task(qp, entry, offset);
1118
1119         qp->tx_index++;
1120         qp->tx_index %= qp->tx_max_entry;
1121
1122         qp->tx_pkts++;
1123
1124         return 0;
1125 }
1126
1127 static void ntb_send_link_down(struct ntb_transport_qp *qp)
1128 {
1129         struct pci_dev *pdev = ntb_query_pdev(qp->ndev);
1130         struct ntb_queue_entry *entry;
1131         int i, rc;
1132
1133         if (qp->qp_link == NTB_LINK_DOWN)
1134                 return;
1135
1136         qp->qp_link = NTB_LINK_DOWN;
1137         dev_info(&pdev->dev, "qp %d: Link Down\n", qp->qp_num);
1138
1139         for (i = 0; i < NTB_LINK_DOWN_TIMEOUT; i++) {
1140                 entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1141                 if (entry)
1142                         break;
1143                 msleep(100);
1144         }
1145
1146         if (!entry)
1147                 return;
1148
1149         entry->cb_data = NULL;
1150         entry->buf = NULL;
1151         entry->len = 0;
1152         entry->flags = LINK_DOWN_FLAG;
1153
1154         rc = ntb_process_tx(qp, entry);
1155         if (rc)
1156                 dev_err(&pdev->dev, "ntb: QP%d unable to send linkdown msg\n",
1157                         qp->qp_num);
1158 }
1159
1160 /**
1161  * ntb_transport_create_queue - Create a new NTB transport layer queue
1162  * @rx_handler: receive callback function
1163  * @tx_handler: transmit callback function
1164  * @event_handler: event callback function
1165  *
1166  * Create a new NTB transport layer queue and provide the queue with a callback
1167  * routine for both transmit and receive.  The receive callback routine will be
1168  * used to pass up data when the transport has received it on the queue.   The
1169  * transmit callback routine will be called when the transport has completed the
1170  * transmission of the data on the queue and the data is ready to be freed.
1171  *
1172  * RETURNS: pointer to newly created ntb_queue, NULL on error.
1173  */
1174 struct ntb_transport_qp *
1175 ntb_transport_create_queue(void *data, struct pci_dev *pdev,
1176                            const struct ntb_queue_handlers *handlers)
1177 {
1178         struct ntb_queue_entry *entry;
1179         struct ntb_transport_qp *qp;
1180         struct ntb_transport *nt;
1181         unsigned int free_queue;
1182         int rc, i;
1183
1184         nt = ntb_find_transport(pdev);
1185         if (!nt)
1186                 goto err;
1187
1188         free_queue = ffs(nt->qp_bitmap);
1189         if (!free_queue)
1190                 goto err;
1191
1192         /* decrement free_queue to make it zero based */
1193         free_queue--;
1194
1195         clear_bit(free_queue, &nt->qp_bitmap);
1196
1197         qp = &nt->qps[free_queue];
1198         qp->cb_data = data;
1199         qp->rx_handler = handlers->rx_handler;
1200         qp->tx_handler = handlers->tx_handler;
1201         qp->event_handler = handlers->event_handler;
1202
1203         for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
1204                 entry = kzalloc(sizeof(struct ntb_queue_entry), GFP_ATOMIC);
1205                 if (!entry)
1206                         goto err1;
1207
1208                 ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry,
1209                              &qp->rx_free_q);
1210         }
1211
1212         for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
1213                 entry = kzalloc(sizeof(struct ntb_queue_entry), GFP_ATOMIC);
1214                 if (!entry)
1215                         goto err2;
1216
1217                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1218                              &qp->tx_free_q);
1219         }
1220
1221         tasklet_init(&qp->rx_work, ntb_transport_rx, (unsigned long) qp);
1222
1223         rc = ntb_register_db_callback(qp->ndev, free_queue, qp,
1224                                       ntb_transport_rxc_db);
1225         if (rc)
1226                 goto err3;
1227
1228         dev_info(&pdev->dev, "NTB Transport QP %d created\n", qp->qp_num);
1229
1230         return qp;
1231
1232 err3:
1233         tasklet_disable(&qp->rx_work);
1234 err2:
1235         while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1236                 kfree(entry);
1237 err1:
1238         while ((entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q)))
1239                 kfree(entry);
1240         set_bit(free_queue, &nt->qp_bitmap);
1241 err:
1242         return NULL;
1243 }
1244 EXPORT_SYMBOL_GPL(ntb_transport_create_queue);
1245
1246 /**
1247  * ntb_transport_free_queue - Frees NTB transport queue
1248  * @qp: NTB queue to be freed
1249  *
1250  * Frees NTB transport queue
1251  */
1252 void ntb_transport_free_queue(struct ntb_transport_qp *qp)
1253 {
1254         struct pci_dev *pdev;
1255         struct ntb_queue_entry *entry;
1256
1257         if (!qp)
1258                 return;
1259
1260         pdev = ntb_query_pdev(qp->ndev);
1261
1262         cancel_delayed_work_sync(&qp->link_work);
1263
1264         ntb_unregister_db_callback(qp->ndev, qp->qp_num);
1265         tasklet_disable(&qp->rx_work);
1266
1267         while ((entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q)))
1268                 kfree(entry);
1269
1270         while ((entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q))) {
1271                 dev_warn(&pdev->dev, "Freeing item from a non-empty queue\n");
1272                 kfree(entry);
1273         }
1274
1275         while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1276                 kfree(entry);
1277
1278         set_bit(qp->qp_num, &qp->transport->qp_bitmap);
1279
1280         dev_info(&pdev->dev, "NTB Transport QP %d freed\n", qp->qp_num);
1281 }
1282 EXPORT_SYMBOL_GPL(ntb_transport_free_queue);
1283
1284 /**
1285  * ntb_transport_rx_remove - Dequeues enqueued rx packet
1286  * @qp: NTB queue to be freed
1287  * @len: pointer to variable to write enqueued buffers length
1288  *
1289  * Dequeues unused buffers from receive queue.  Should only be used during
1290  * shutdown of qp.
1291  *
1292  * RETURNS: NULL error value on error, or void* for success.
1293  */
1294 void *ntb_transport_rx_remove(struct ntb_transport_qp *qp, unsigned int *len)
1295 {
1296         struct ntb_queue_entry *entry;
1297         void *buf;
1298
1299         if (!qp || qp->client_ready == NTB_LINK_UP)
1300                 return NULL;
1301
1302         entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q);
1303         if (!entry)
1304                 return NULL;
1305
1306         buf = entry->cb_data;
1307         *len = entry->len;
1308
1309         ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry, &qp->rx_free_q);
1310
1311         return buf;
1312 }
1313 EXPORT_SYMBOL_GPL(ntb_transport_rx_remove);
1314
1315 /**
1316  * ntb_transport_rx_enqueue - Enqueue a new NTB queue entry
1317  * @qp: NTB transport layer queue the entry is to be enqueued on
1318  * @cb: per buffer pointer for callback function to use
1319  * @data: pointer to data buffer that incoming packets will be copied into
1320  * @len: length of the data buffer
1321  *
1322  * Enqueue a new receive buffer onto the transport queue into which a NTB
1323  * payload can be received into.
1324  *
1325  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
1326  */
1327 int ntb_transport_rx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
1328                              unsigned int len)
1329 {
1330         struct ntb_queue_entry *entry;
1331
1332         if (!qp)
1333                 return -EINVAL;
1334
1335         entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q);
1336         if (!entry)
1337                 return -ENOMEM;
1338
1339         entry->cb_data = cb;
1340         entry->buf = data;
1341         entry->len = len;
1342
1343         ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry, &qp->rx_pend_q);
1344
1345         return 0;
1346 }
1347 EXPORT_SYMBOL_GPL(ntb_transport_rx_enqueue);
1348
1349 /**
1350  * ntb_transport_tx_enqueue - Enqueue a new NTB queue entry
1351  * @qp: NTB transport layer queue the entry is to be enqueued on
1352  * @cb: per buffer pointer for callback function to use
1353  * @data: pointer to data buffer that will be sent
1354  * @len: length of the data buffer
1355  *
1356  * Enqueue a new transmit buffer onto the transport queue from which a NTB
1357  * payload will be transmitted.  This assumes that a lock is behing held to
1358  * serialize access to the qp.
1359  *
1360  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
1361  */
1362 int ntb_transport_tx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
1363                              unsigned int len)
1364 {
1365         struct ntb_queue_entry *entry;
1366         int rc;
1367
1368         if (!qp || qp->qp_link != NTB_LINK_UP || !len)
1369                 return -EINVAL;
1370
1371         entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1372         if (!entry)
1373                 return -ENOMEM;
1374
1375         entry->cb_data = cb;
1376         entry->buf = data;
1377         entry->len = len;
1378         entry->flags = 0;
1379
1380         rc = ntb_process_tx(qp, entry);
1381         if (rc)
1382                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1383                              &qp->tx_free_q);
1384
1385         return rc;
1386 }
1387 EXPORT_SYMBOL_GPL(ntb_transport_tx_enqueue);
1388
1389 /**
1390  * ntb_transport_link_up - Notify NTB transport of client readiness to use queue
1391  * @qp: NTB transport layer queue to be enabled
1392  *
1393  * Notify NTB transport layer of client readiness to use queue
1394  */
1395 void ntb_transport_link_up(struct ntb_transport_qp *qp)
1396 {
1397         if (!qp)
1398                 return;
1399
1400         qp->client_ready = NTB_LINK_UP;
1401
1402         if (qp->transport->transport_link == NTB_LINK_UP)
1403                 schedule_delayed_work(&qp->link_work, 0);
1404 }
1405 EXPORT_SYMBOL_GPL(ntb_transport_link_up);
1406
1407 /**
1408  * ntb_transport_link_down - Notify NTB transport to no longer enqueue data
1409  * @qp: NTB transport layer queue to be disabled
1410  *
1411  * Notify NTB transport layer of client's desire to no longer receive data on
1412  * transport queue specified.  It is the client's responsibility to ensure all
1413  * entries on queue are purged or otherwise handled appropraitely.
1414  */
1415 void ntb_transport_link_down(struct ntb_transport_qp *qp)
1416 {
1417         struct pci_dev *pdev;
1418         int rc, val;
1419
1420         if (!qp)
1421                 return;
1422
1423         pdev = ntb_query_pdev(qp->ndev);
1424         qp->client_ready = NTB_LINK_DOWN;
1425
1426         rc = ntb_read_local_spad(qp->ndev, QP_LINKS, &val);
1427         if (rc) {
1428                 dev_err(&pdev->dev, "Error reading spad %d\n", QP_LINKS);
1429                 return;
1430         }
1431
1432         rc = ntb_write_remote_spad(qp->ndev, QP_LINKS,
1433                                    val & ~(1 << qp->qp_num));
1434         if (rc)
1435                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
1436                         val & ~(1 << qp->qp_num), QP_LINKS);
1437
1438         if (qp->qp_link == NTB_LINK_UP)
1439                 ntb_send_link_down(qp);
1440         else
1441                 cancel_delayed_work_sync(&qp->link_work);
1442 }
1443 EXPORT_SYMBOL_GPL(ntb_transport_link_down);
1444
1445 /**
1446  * ntb_transport_link_query - Query transport link state
1447  * @qp: NTB transport layer queue to be queried
1448  *
1449  * Query connectivity to the remote system of the NTB transport queue
1450  *
1451  * RETURNS: true for link up or false for link down
1452  */
1453 bool ntb_transport_link_query(struct ntb_transport_qp *qp)
1454 {
1455         if (!qp)
1456                 return false;
1457
1458         return qp->qp_link == NTB_LINK_UP;
1459 }
1460 EXPORT_SYMBOL_GPL(ntb_transport_link_query);
1461
1462 /**
1463  * ntb_transport_qp_num - Query the qp number
1464  * @qp: NTB transport layer queue to be queried
1465  *
1466  * Query qp number of the NTB transport queue
1467  *
1468  * RETURNS: a zero based number specifying the qp number
1469  */
1470 unsigned char ntb_transport_qp_num(struct ntb_transport_qp *qp)
1471 {
1472         if (!qp)
1473                 return 0;
1474
1475         return qp->qp_num;
1476 }
1477 EXPORT_SYMBOL_GPL(ntb_transport_qp_num);
1478
1479 /**
1480  * ntb_transport_max_size - Query the max payload size of a qp
1481  * @qp: NTB transport layer queue to be queried
1482  *
1483  * Query the maximum payload size permissible on the given qp
1484  *
1485  * RETURNS: the max payload size of a qp
1486  */
1487 unsigned int ntb_transport_max_size(struct ntb_transport_qp *qp)
1488 {
1489         if (!qp)
1490                 return 0;
1491
1492         return qp->tx_max_frame - sizeof(struct ntb_payload_header);
1493 }
1494 EXPORT_SYMBOL_GPL(ntb_transport_max_size);