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