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   1
  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_transport_qp {
  82         struct ntb_transport *transport;
  83         struct ntb_device *ndev;
  84         void *cb_data;
  85
  86         bool client_ready;
  87         bool qp_link;
  88         u8 qp_num;      /* Only 64 QP's are allowed.  0-63 */
  89
  90         void (*tx_handler) (struct ntb_transport_qp *qp, void *qp_data,
  91                             void *data, int len);
  92         struct list_head tx_free_q;
  93         spinlock_t ntb_tx_free_q_lock;
  94         void *tx_mw_begin;
  95         void *tx_mw_end;
  96         void *tx_offset;
  97         unsigned int tx_max_frame;
  98
  99         void (*rx_handler) (struct ntb_transport_qp *qp, void *qp_data,
 100                             void *data, int len);
 101         struct tasklet_struct rx_work;
 102         struct list_head rx_pend_q;
 103         struct list_head rx_free_q;
 104         spinlock_t ntb_rx_pend_q_lock;
 105         spinlock_t ntb_rx_free_q_lock;
 106         void *rx_buff_begin;
 107         void *rx_buff_end;
 108         void *rx_offset;
 109         unsigned int rx_max_frame;
 110
 111         void (*event_handler) (void *data, int status);
 112         struct delayed_work link_work;
 113         struct work_struct link_cleanup;
 114
 115         struct dentry *debugfs_dir;
 116         struct dentry *debugfs_stats;
 117
 118         /* Stats */
 119         u64 rx_bytes;
 120         u64 rx_pkts;
 121         u64 rx_ring_empty;
 122         u64 rx_err_no_buf;
 123         u64 rx_err_oflow;
 124         u64 rx_err_ver;
 125         u64 tx_bytes;
 126         u64 tx_pkts;
 127         u64 tx_ring_full;
 128 };
 129
 130 struct ntb_transport_mw {
 131         size_t size;
 132         void *virt_addr;
 133         dma_addr_t dma_addr;
 134 };
 135
 136 struct ntb_transport_client_dev {
 137         struct list_head entry;
 138         struct device dev;
 139 };
 140
 141 struct ntb_transport {
 142         struct list_head entry;
 143         struct list_head client_devs;
 144
 145         struct ntb_device *ndev;
 146         struct ntb_transport_mw mw[NTB_NUM_MW];
 147         struct ntb_transport_qp *qps;
 148         unsigned int max_qps;
 149         unsigned long qp_bitmap;
 150         bool transport_link;
 151         struct delayed_work link_work;
 152         struct work_struct link_cleanup;
 153         struct dentry *debugfs_dir;
 154 };
 155
 156 enum {
 157         DESC_DONE_FLAG = 1 << 0,
 158         LINK_DOWN_FLAG = 1 << 1,
 159 };
 160
 161 struct ntb_payload_header {
 162         u64 ver;
 163         unsigned int len;
 164         unsigned int flags;
 165 };
 166
 167 enum {
 168         VERSION = 0,
 169         MW0_SZ,
 170         MW1_SZ,
 171         NUM_QPS,
 172         QP_LINKS,
 173         MAX_SPAD,
 174 };
 175
 176 #define QP_TO_MW(qp)            ((qp) % NTB_NUM_MW)
 177 #define NTB_QP_DEF_NUM_ENTRIES  100
 178 #define NTB_LINK_DOWN_TIMEOUT   10
 179
 180 static int ntb_match_bus(struct device *dev, struct device_driver *drv)
 181 {
 182         return !strncmp(dev_name(dev), drv->name, strlen(drv->name));
 183 }
 184
 185 static int ntb_client_probe(struct device *dev)
 186 {
 187         const struct ntb_client *drv = container_of(dev->driver,
 188                                                     struct ntb_client, driver);
 189         struct pci_dev *pdev = container_of(dev->parent, struct pci_dev, dev);
 190         int rc = -EINVAL;
 191
 192         get_device(dev);
 193         if (drv && drv->probe)
 194                 rc = drv->probe(pdev);
 195         if (rc)
 196                 put_device(dev);
 197
 198         return rc;
 199 }
 200
 201 static int ntb_client_remove(struct device *dev)
 202 {
 203         const struct ntb_client *drv = container_of(dev->driver,
 204                                                     struct ntb_client, driver);
 205         struct pci_dev *pdev = container_of(dev->parent, struct pci_dev, dev);
 206
 207         if (drv && drv->remove)
 208                 drv->remove(pdev);
 209
 210         put_device(dev);
 211
 212         return 0;
 213 }
 214
 215 struct bus_type ntb_bus_type = {
 216         .name = "ntb_bus",
 217         .match = ntb_match_bus,
 218         .probe = ntb_client_probe,
 219         .remove = ntb_client_remove,
 220 };
 221
 222 static LIST_HEAD(ntb_transport_list);
 223
 224 static int ntb_bus_init(struct ntb_transport *nt)
 225 {
 226         if (list_empty(&ntb_transport_list)) {
 227                 int rc = bus_register(&ntb_bus_type);
 228                 if (rc)
 229                         return rc;
 230         }
 231
 232         list_add(&nt->entry, &ntb_transport_list);
 233
 234         return 0;
 235 }
 236
 237 static void ntb_bus_remove(struct ntb_transport *nt)
 238 {
 239         struct ntb_transport_client_dev *client_dev, *cd;
 240
 241         list_for_each_entry_safe(client_dev, cd, &nt->client_devs, entry) {
 242                 dev_err(client_dev->dev.parent, "%s still attached to bus, removing\n",
 243                         dev_name(&client_dev->dev));
 244                 list_del(&client_dev->entry);
 245                 device_unregister(&client_dev->dev);
 246         }
 247
 248         list_del(&nt->entry);
 249
 250         if (list_empty(&ntb_transport_list))
 251                 bus_unregister(&ntb_bus_type);
 252 }
 253
 254 static void ntb_client_release(struct device *dev)
 255 {
 256         struct ntb_transport_client_dev *client_dev;
 257         client_dev = container_of(dev, struct ntb_transport_client_dev, dev);
 258
 259         kfree(client_dev);
 260 }
 261
 262 /**
 263  * ntb_unregister_client_dev - Unregister NTB client device
 264  * @device_name: Name of NTB client device
 265  *
 266  * Unregister an NTB client device with the NTB transport layer
 267  */
 268 void ntb_unregister_client_dev(char *device_name)
 269 {
 270         struct ntb_transport_client_dev *client, *cd;
 271         struct ntb_transport *nt;
 272
 273         list_for_each_entry(nt, &ntb_transport_list, entry)
 274                 list_for_each_entry_safe(client, cd, &nt->client_devs, entry)
 275                         if (!strncmp(dev_name(&client->dev), device_name,
 276                                      strlen(device_name))) {
 277                                 list_del(&client->entry);
 278                                 device_unregister(&client->dev);
 279                         }
 280 }
 281 EXPORT_SYMBOL_GPL(ntb_unregister_client_dev);
 282
 283 /**
 284  * ntb_register_client_dev - Register NTB client device
 285  * @device_name: Name of NTB client device
 286  *
 287  * Register an NTB client device with the NTB transport layer
 288  */
 289 int ntb_register_client_dev(char *device_name)
 290 {
 291         struct ntb_transport_client_dev *client_dev;
 292         struct ntb_transport *nt;
 293         int rc;
 294
 295         if (list_empty(&ntb_transport_list))
 296                 return -ENODEV;
 297
 298         list_for_each_entry(nt, &ntb_transport_list, entry) {
 299                 struct device *dev;
 300
 301                 client_dev = kzalloc(sizeof(struct ntb_transport_client_dev),
 302                                      GFP_KERNEL);
 303                 if (!client_dev) {
 304                         rc = -ENOMEM;
 305                         goto err;
 306                 }
 307
 308                 dev = &client_dev->dev;
 309
 310                 /* setup and register client devices */
 311                 dev_set_name(dev, "%s", device_name);
 312                 dev->bus = &ntb_bus_type;
 313                 dev->release = ntb_client_release;
 314                 dev->parent = &ntb_query_pdev(nt->ndev)->dev;
 315
 316                 rc = device_register(dev);
 317                 if (rc) {
 318                         kfree(client_dev);
 319                         goto err;
 320                 }
 321
 322                 list_add_tail(&client_dev->entry, &nt->client_devs);
 323         }
 324
 325         return 0;
 326
 327 err:
 328         ntb_unregister_client_dev(device_name);
 329
 330         return rc;
 331 }
 332 EXPORT_SYMBOL_GPL(ntb_register_client_dev);
 333
 334 /**
 335  * ntb_register_client - Register NTB client driver
 336  * @drv: NTB client driver to be registered
 337  *
 338  * Register an NTB client driver with the NTB transport layer
 339  *
 340  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 341  */
 342 int ntb_register_client(struct ntb_client *drv)
 343 {
 344         drv->driver.bus = &ntb_bus_type;
 345
 346         if (list_empty(&ntb_transport_list))
 347                 return -ENODEV;
 348
 349         return driver_register(&drv->driver);
 350 }
 351 EXPORT_SYMBOL_GPL(ntb_register_client);
 352
 353 /**
 354  * ntb_unregister_client - Unregister NTB client driver
 355  * @drv: NTB client driver to be unregistered
 356  *
 357  * Unregister an NTB client driver with the NTB transport layer
 358  *
 359  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 360  */
 361 void ntb_unregister_client(struct ntb_client *drv)
 362 {
 363         driver_unregister(&drv->driver);
 364 }
 365 EXPORT_SYMBOL_GPL(ntb_unregister_client);
 366
 367 static int debugfs_open(struct inode *inode, struct file *filp)
 368 {
 369         filp->private_data = inode->i_private;
 370         return 0;
 371 }
 372
 373 static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count,
 374                             loff_t *offp)
 375 {
 376         struct ntb_transport_qp *qp;
 377         char buf[1024];
 378         ssize_t ret, out_offset, out_count;
 379
 380         out_count = 1024;
 381
 382         qp = filp->private_data;
 383         out_offset = 0;
 384         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 385                                "NTB QP stats\n");
 386         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 387                                "rx_bytes - \t%llu\n", qp->rx_bytes);
 388         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 389                                "rx_pkts - \t%llu\n", qp->rx_pkts);
 390         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 391                                "rx_ring_empty - %llu\n", qp->rx_ring_empty);
 392         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 393                                "rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
 394         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 395                                "rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
 396         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 397                                "rx_err_ver - \t%llu\n", qp->rx_err_ver);
 398         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 399                                "rx_buff_begin - %p\n", qp->rx_buff_begin);
 400         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 401                                "rx_offset - \t%p\n", qp->rx_offset);
 402         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 403                                "rx_buff_end - \t%p\n", qp->rx_buff_end);
 404
 405         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 406                                "tx_bytes - \t%llu\n", qp->tx_bytes);
 407         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 408                                "tx_pkts - \t%llu\n", qp->tx_pkts);
 409         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 410                                "tx_ring_full - \t%llu\n", qp->tx_ring_full);
 411         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 412                                "tx_mw_begin - \t%p\n", qp->tx_mw_begin);
 413         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 414                                "tx_offset - \t%p\n", qp->tx_offset);
 415         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 416                                "tx_mw_end - \t%p\n", qp->tx_mw_end);
 417
 418         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 419                                "QP Link %s\n", (qp->qp_link == NTB_LINK_UP) ?
 420                                "Up" : "Down");
 421
 422         ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
 423         return ret;
 424 }
 425
 426 static const struct file_operations ntb_qp_debugfs_stats = {
 427         .owner = THIS_MODULE,
 428         .open = debugfs_open,
 429         .read = debugfs_read,
 430 };
 431
 432 static void ntb_list_add(spinlock_t *lock, struct list_head *entry,
 433                          struct list_head *list)
 434 {
 435         unsigned long flags;
 436
 437         spin_lock_irqsave(lock, flags);
 438         list_add_tail(entry, list);
 439         spin_unlock_irqrestore(lock, flags);
 440 }
 441
 442 static struct ntb_queue_entry *ntb_list_rm(spinlock_t *lock,
 443                                                 struct list_head *list)
 444 {
 445         struct ntb_queue_entry *entry;
 446         unsigned long flags;
 447
 448         spin_lock_irqsave(lock, flags);
 449         if (list_empty(list)) {
 450                 entry = NULL;
 451                 goto out;
 452         }
 453         entry = list_first_entry(list, struct ntb_queue_entry, entry);
 454         list_del(&entry->entry);
 455 out:
 456         spin_unlock_irqrestore(lock, flags);
 457
 458         return entry;
 459 }
 460
 461 static void ntb_transport_setup_qp_mw(struct ntb_transport *nt,
 462                                       unsigned int qp_num)
 463 {
 464         struct ntb_transport_qp *qp = &nt->qps[qp_num];
 465         unsigned int rx_size, num_qps_mw;
 466         u8 mw_num = QP_TO_MW(qp_num);
 467         void *offset;
 468
 469         WARN_ON(nt->mw[mw_num].virt_addr == 0);
 470
 471         if (nt->max_qps % NTB_NUM_MW && mw_num < nt->max_qps % NTB_NUM_MW)
 472                 num_qps_mw = nt->max_qps / NTB_NUM_MW + 1;
 473         else
 474                 num_qps_mw = nt->max_qps / NTB_NUM_MW;
 475
 476         rx_size = nt->mw[mw_num].size / num_qps_mw;
 477         qp->rx_buff_begin = nt->mw[mw_num].virt_addr +
 478                             (qp_num / NTB_NUM_MW * rx_size);
 479         qp->rx_buff_end = qp->rx_buff_begin + rx_size;
 480         qp->rx_offset = qp->rx_buff_begin;
 481         qp->rx_max_frame = min(transport_mtu, rx_size);
 482
 483         /* setup the hdr offsets with 0's */
 484         for (offset = qp->rx_buff_begin + qp->rx_max_frame -
 485                       sizeof(struct ntb_payload_header);
 486              offset < qp->rx_buff_end; offset += qp->rx_max_frame)
 487                 memset(offset, 0, sizeof(struct ntb_payload_header));
 488
 489         qp->rx_pkts = 0;
 490         qp->tx_pkts = 0;
 491 }
 492
 493 static int ntb_set_mw(struct ntb_transport *nt, int num_mw, unsigned int size)
 494 {
 495         struct ntb_transport_mw *mw = &nt->mw[num_mw];
 496         struct pci_dev *pdev = ntb_query_pdev(nt->ndev);
 497
 498         /* Alloc memory for receiving data.  Must be 4k aligned */
 499         mw->size = ALIGN(size, 4096);
 500
 501         mw->virt_addr = dma_alloc_coherent(&pdev->dev, mw->size, &mw->dma_addr,
 502                                            GFP_KERNEL);
 503         if (!mw->virt_addr) {
 504                 dev_err(&pdev->dev, "Unable to allocate MW buffer of size %d\n",
 505                        (int) mw->size);
 506                 return -ENOMEM;
 507         }
 508
 509         /* Notify HW the memory location of the receive buffer */
 510         ntb_set_mw_addr(nt->ndev, num_mw, mw->dma_addr);
 511
 512         return 0;
 513 }
 514
 515 static void ntb_qp_link_cleanup(struct work_struct *work)
 516 {
 517         struct ntb_transport_qp *qp = container_of(work,
 518                                                    struct ntb_transport_qp,
 519                                                    link_cleanup);
 520         struct ntb_transport *nt = qp->transport;
 521         struct pci_dev *pdev = ntb_query_pdev(nt->ndev);
 522
 523         if (qp->qp_link == NTB_LINK_DOWN) {
 524                 cancel_delayed_work_sync(&qp->link_work);
 525                 return;
 526         }
 527
 528         if (qp->event_handler)
 529                 qp->event_handler(qp->cb_data, NTB_LINK_DOWN);
 530
 531         dev_info(&pdev->dev, "qp %d: Link Down\n", qp->qp_num);
 532         qp->qp_link = NTB_LINK_DOWN;
 533
 534         if (nt->transport_link == NTB_LINK_UP)
 535                 schedule_delayed_work(&qp->link_work,
 536                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 537 }
 538
 539 static void ntb_qp_link_down(struct ntb_transport_qp *qp)
 540 {
 541         schedule_work(&qp->link_cleanup);
 542 }
 543
 544 static void ntb_transport_link_cleanup(struct work_struct *work)
 545 {
 546         struct ntb_transport *nt = container_of(work, struct ntb_transport,
 547                                                 link_cleanup);
 548         int i;
 549
 550         if (nt->transport_link == NTB_LINK_DOWN)
 551                 cancel_delayed_work_sync(&nt->link_work);
 552         else
 553                 nt->transport_link = NTB_LINK_DOWN;
 554
 555         /* Pass along the info to any clients */
 556         for (i = 0; i < nt->max_qps; i++)
 557                 if (!test_bit(i, &nt->qp_bitmap))
 558                         ntb_qp_link_down(&nt->qps[i]);
 559
 560         /* The scratchpad registers keep the values if the remote side
 561          * goes down, blast them now to give them a sane value the next
 562          * time they are accessed
 563          */
 564         for (i = 0; i < MAX_SPAD; i++)
 565                 ntb_write_local_spad(nt->ndev, i, 0);
 566 }
 567
 568 static void ntb_transport_event_callback(void *data, enum ntb_hw_event event)
 569 {
 570         struct ntb_transport *nt = data;
 571
 572         switch (event) {
 573         case NTB_EVENT_HW_LINK_UP:
 574                 schedule_delayed_work(&nt->link_work, 0);
 575                 break;
 576         case NTB_EVENT_HW_LINK_DOWN:
 577                 schedule_work(&nt->link_cleanup);
 578                 break;
 579         default:
 580                 BUG();
 581         }
 582 }
 583
 584 static void ntb_transport_link_work(struct work_struct *work)
 585 {
 586         struct ntb_transport *nt = container_of(work, struct ntb_transport,
 587                                                 link_work.work);
 588         struct ntb_device *ndev = nt->ndev;
 589         struct pci_dev *pdev = ntb_query_pdev(ndev);
 590         u32 val;
 591         int rc, i;
 592
 593         /* send the local info */
 594         rc = ntb_write_remote_spad(ndev, VERSION, NTB_TRANSPORT_VERSION);
 595         if (rc) {
 596                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
 597                         0, VERSION);
 598                 goto out;
 599         }
 600
 601         rc = ntb_write_remote_spad(ndev, MW0_SZ, ntb_get_mw_size(ndev, 0));
 602         if (rc) {
 603                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
 604                         (u32) ntb_get_mw_size(ndev, 0), MW0_SZ);
 605                 goto out;
 606         }
 607
 608         rc = ntb_write_remote_spad(ndev, MW1_SZ, ntb_get_mw_size(ndev, 1));
 609         if (rc) {
 610                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
 611                         (u32) ntb_get_mw_size(ndev, 1), MW1_SZ);
 612                 goto out;
 613         }
 614
 615         rc = ntb_write_remote_spad(ndev, NUM_QPS, nt->max_qps);
 616         if (rc) {
 617                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
 618                         nt->max_qps, NUM_QPS);
 619                 goto out;
 620         }
 621
 622         rc = ntb_read_local_spad(nt->ndev, QP_LINKS, &val);
 623         if (rc) {
 624                 dev_err(&pdev->dev, "Error reading spad %d\n", QP_LINKS);
 625                 goto out;
 626         }
 627
 628         rc = ntb_write_remote_spad(ndev, QP_LINKS, val);
 629         if (rc) {
 630                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
 631                         val, QP_LINKS);
 632                 goto out;
 633         }
 634
 635         /* Query the remote side for its info */
 636         rc = ntb_read_remote_spad(ndev, VERSION, &val);
 637         if (rc) {
 638                 dev_err(&pdev->dev, "Error reading remote spad %d\n", VERSION);
 639                 goto out;
 640         }
 641
 642         if (val != NTB_TRANSPORT_VERSION)
 643                 goto out;
 644         dev_dbg(&pdev->dev, "Remote version = %d\n", val);
 645
 646         rc = ntb_read_remote_spad(ndev, NUM_QPS, &val);
 647         if (rc) {
 648                 dev_err(&pdev->dev, "Error reading remote spad %d\n", NUM_QPS);
 649                 goto out;
 650         }
 651
 652         if (val != nt->max_qps)
 653                 goto out;
 654         dev_dbg(&pdev->dev, "Remote max number of qps = %d\n", val);
 655
 656         rc = ntb_read_remote_spad(ndev, MW0_SZ, &val);
 657         if (rc) {
 658                 dev_err(&pdev->dev, "Error reading remote spad %d\n", MW0_SZ);
 659                 goto out;
 660         }
 661
 662         if (!val)
 663                 goto out;
 664         dev_dbg(&pdev->dev, "Remote MW0 size = %d\n", val);
 665
 666         rc = ntb_set_mw(nt, 0, val);
 667         if (rc)
 668                 goto out;
 669
 670         rc = ntb_read_remote_spad(ndev, MW1_SZ, &val);
 671         if (rc) {
 672                 dev_err(&pdev->dev, "Error reading remote spad %d\n", MW1_SZ);
 673                 goto out;
 674         }
 675
 676         if (!val)
 677                 goto out;
 678         dev_dbg(&pdev->dev, "Remote MW1 size = %d\n", val);
 679
 680         rc = ntb_set_mw(nt, 1, val);
 681         if (rc)
 682                 goto out;
 683
 684         nt->transport_link = NTB_LINK_UP;
 685
 686         for (i = 0; i < nt->max_qps; i++) {
 687                 struct ntb_transport_qp *qp = &nt->qps[i];
 688
 689                 ntb_transport_setup_qp_mw(nt, i);
 690
 691                 if (qp->client_ready == NTB_LINK_UP)
 692                         schedule_delayed_work(&qp->link_work, 0);
 693         }
 694
 695         return;
 696
 697 out:
 698         if (ntb_hw_link_status(ndev))
 699                 schedule_delayed_work(&nt->link_work,
 700                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 701 }
 702
 703 static void ntb_qp_link_work(struct work_struct *work)
 704 {
 705         struct ntb_transport_qp *qp = container_of(work,
 706                                                    struct ntb_transport_qp,
 707                                                    link_work.work);
 708         struct pci_dev *pdev = ntb_query_pdev(qp->ndev);
 709         struct ntb_transport *nt = qp->transport;
 710         int rc, val;
 711
 712         WARN_ON(nt->transport_link != NTB_LINK_UP);
 713
 714         rc = ntb_read_local_spad(nt->ndev, QP_LINKS, &val);
 715         if (rc) {
 716                 dev_err(&pdev->dev, "Error reading spad %d\n", QP_LINKS);
 717                 return;
 718         }
 719
 720         rc = ntb_write_remote_spad(nt->ndev, QP_LINKS, val | 1 << qp->qp_num);
 721         if (rc)
 722                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
 723                         val | 1 << qp->qp_num, QP_LINKS);
 724
 725         /* query remote spad for qp ready bits */
 726         rc = ntb_read_remote_spad(nt->ndev, QP_LINKS, &val);
 727         if (rc)
 728                 dev_err(&pdev->dev, "Error reading remote spad %d\n", QP_LINKS);
 729
 730         dev_dbg(&pdev->dev, "Remote QP link status = %x\n", val);
 731
 732         /* See if the remote side is up */
 733         if (1 << qp->qp_num & val) {
 734                 qp->qp_link = NTB_LINK_UP;
 735
 736                 dev_info(&pdev->dev, "qp %d: Link Up\n", qp->qp_num);
 737                 if (qp->event_handler)
 738                         qp->event_handler(qp->cb_data, NTB_LINK_UP);
 739         } else if (nt->transport_link == NTB_LINK_UP)
 740                 schedule_delayed_work(&qp->link_work,
 741                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 742 }
 743
 744 static void ntb_transport_init_queue(struct ntb_transport *nt,
 745                                      unsigned int qp_num)
 746 {
 747         struct ntb_transport_qp *qp;
 748         unsigned int num_qps_mw, tx_size;
 749         u8 mw_num = QP_TO_MW(qp_num);
 750
 751         qp = &nt->qps[qp_num];
 752         qp->qp_num = qp_num;
 753         qp->transport = nt;
 754         qp->ndev = nt->ndev;
 755         qp->qp_link = NTB_LINK_DOWN;
 756         qp->client_ready = NTB_LINK_DOWN;
 757         qp->event_handler = NULL;
 758
 759         if (nt->max_qps % NTB_NUM_MW && mw_num < nt->max_qps % NTB_NUM_MW)
 760                 num_qps_mw = nt->max_qps / NTB_NUM_MW + 1;
 761         else
 762                 num_qps_mw = nt->max_qps / NTB_NUM_MW;
 763
 764         tx_size = ntb_get_mw_size(qp->ndev, mw_num) / num_qps_mw;
 765         qp->tx_mw_begin = ntb_get_mw_vbase(nt->ndev, mw_num) +
 766                           (qp_num / NTB_NUM_MW * tx_size);
 767         qp->tx_mw_end = qp->tx_mw_begin + tx_size;
 768         qp->tx_offset = qp->tx_mw_begin;
 769         qp->tx_max_frame = min(transport_mtu, tx_size);
 770
 771         if (nt->debugfs_dir) {
 772                 char debugfs_name[4];
 773
 774                 snprintf(debugfs_name, 4, "qp%d", qp_num);
 775                 qp->debugfs_dir = debugfs_create_dir(debugfs_name,
 776                                                      nt->debugfs_dir);
 777
 778                 qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR,
 779                                                         qp->debugfs_dir, qp,
 780                                                         &ntb_qp_debugfs_stats);
 781         }
 782
 783         INIT_DELAYED_WORK(&qp->link_work, ntb_qp_link_work);
 784         INIT_WORK(&qp->link_cleanup, ntb_qp_link_cleanup);
 785
 786         spin_lock_init(&qp->ntb_rx_pend_q_lock);
 787         spin_lock_init(&qp->ntb_rx_free_q_lock);
 788         spin_lock_init(&qp->ntb_tx_free_q_lock);
 789
 790         INIT_LIST_HEAD(&qp->rx_pend_q);
 791         INIT_LIST_HEAD(&qp->rx_free_q);
 792         INIT_LIST_HEAD(&qp->tx_free_q);
 793 }
 794
 795 int ntb_transport_init(struct pci_dev *pdev)
 796 {
 797         struct ntb_transport *nt;
 798         int rc, i;
 799
 800         nt = kzalloc(sizeof(struct ntb_transport), GFP_KERNEL);
 801         if (!nt)
 802                 return -ENOMEM;
 803
 804         if (debugfs_initialized())
 805                 nt->debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
 806         else
 807                 nt->debugfs_dir = NULL;
 808
 809         nt->ndev = ntb_register_transport(pdev, nt);
 810         if (!nt->ndev) {
 811                 rc = -EIO;
 812                 goto err;
 813         }
 814
 815         nt->max_qps = min(nt->ndev->max_cbs, max_num_clients);
 816
 817         nt->qps = kcalloc(nt->max_qps, sizeof(struct ntb_transport_qp),
 818                           GFP_KERNEL);
 819         if (!nt->qps) {
 820                 rc = -ENOMEM;
 821                 goto err1;
 822         }
 823
 824         nt->qp_bitmap = ((u64) 1 << nt->max_qps) - 1;
 825
 826         for (i = 0; i < nt->max_qps; i++)
 827                 ntb_transport_init_queue(nt, i);
 828
 829         INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work);
 830         INIT_WORK(&nt->link_cleanup, ntb_transport_link_cleanup);
 831
 832         rc = ntb_register_event_callback(nt->ndev,
 833                                          ntb_transport_event_callback);
 834         if (rc)
 835                 goto err2;
 836
 837         INIT_LIST_HEAD(&nt->client_devs);
 838         rc = ntb_bus_init(nt);
 839         if (rc)
 840                 goto err3;
 841
 842         if (ntb_hw_link_status(nt->ndev))
 843                 schedule_delayed_work(&nt->link_work, 0);
 844
 845         return 0;
 846
 847 err3:
 848         ntb_unregister_event_callback(nt->ndev);
 849 err2:
 850         kfree(nt->qps);
 851 err1:
 852         ntb_unregister_transport(nt->ndev);
 853 err:
 854         debugfs_remove_recursive(nt->debugfs_dir);
 855         kfree(nt);
 856         return rc;
 857 }
 858
 859 void ntb_transport_free(void *transport)
 860 {
 861         struct ntb_transport *nt = transport;
 862         struct pci_dev *pdev;
 863         int i;
 864
 865         nt->transport_link = NTB_LINK_DOWN;
 866
 867         /* verify that all the qp's are freed */
 868         for (i = 0; i < nt->max_qps; i++)
 869                 if (!test_bit(i, &nt->qp_bitmap))
 870                         ntb_transport_free_queue(&nt->qps[i]);
 871
 872         ntb_bus_remove(nt);
 873
 874         cancel_delayed_work_sync(&nt->link_work);
 875
 876         debugfs_remove_recursive(nt->debugfs_dir);
 877
 878         ntb_unregister_event_callback(nt->ndev);
 879
 880         pdev = ntb_query_pdev(nt->ndev);
 881
 882         for (i = 0; i < NTB_NUM_MW; i++)
 883                 if (nt->mw[i].virt_addr)
 884                         dma_free_coherent(&pdev->dev, nt->mw[i].size,
 885                                           nt->mw[i].virt_addr,
 886                                           nt->mw[i].dma_addr);
 887
 888         kfree(nt->qps);
 889         ntb_unregister_transport(nt->ndev);
 890         kfree(nt);
 891 }
 892
 893 static void ntb_rx_copy_task(struct ntb_transport_qp *qp,
 894                              struct ntb_queue_entry *entry, void *offset)
 895 {
 896
 897         struct ntb_payload_header *hdr;
 898
 899         BUG_ON(offset < qp->rx_buff_begin ||
 900                offset + qp->rx_max_frame >= qp->rx_buff_end);
 901
 902         hdr = offset + qp->rx_max_frame - sizeof(struct ntb_payload_header);
 903         entry->len = hdr->len;
 904
 905         memcpy(entry->buf, offset, entry->len);
 906
 907         /* Ensure that the data is fully copied out before clearing the flag */
 908         wmb();
 909         hdr->flags = 0;
 910
 911         if (qp->rx_handler && qp->client_ready == NTB_LINK_UP)
 912                 qp->rx_handler(qp, qp->cb_data, entry->cb_data, entry->len);
 913
 914         ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry, &qp->rx_free_q);
 915 }
 916
 917 static int ntb_process_rxc(struct ntb_transport_qp *qp)
 918 {
 919         struct ntb_payload_header *hdr;
 920         struct ntb_queue_entry *entry;
 921         void *offset;
 922
 923         entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q);
 924         if (!entry) {
 925                 hdr = offset + qp->rx_max_frame -
 926                       sizeof(struct ntb_payload_header);
 927                 dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
 928                         "no buffer - HDR ver %llu, len %d, flags %x\n",
 929                         hdr->ver, hdr->len, hdr->flags);
 930                 qp->rx_err_no_buf++;
 931                 return -ENOMEM;
 932         }
 933
 934         offset = qp->rx_offset;
 935         hdr = offset + qp->rx_max_frame - sizeof(struct ntb_payload_header);
 936
 937         if (!(hdr->flags & DESC_DONE_FLAG)) {
 938                 ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
 939                                   &qp->rx_pend_q);
 940                 qp->rx_ring_empty++;
 941                 return -EAGAIN;
 942         }
 943
 944         if (hdr->ver != qp->rx_pkts) {
 945                 dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
 946                         "qp %d: version mismatch, expected %llu - got %llu\n",
 947                         qp->qp_num, qp->rx_pkts, hdr->ver);
 948                 ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
 949                                   &qp->rx_pend_q);
 950                 qp->rx_err_ver++;
 951                 return -EIO;
 952         }
 953
 954         if (hdr->flags & LINK_DOWN_FLAG) {
 955                 ntb_qp_link_down(qp);
 956
 957                 ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
 958                                   &qp->rx_pend_q);
 959
 960                 /* Ensure that the data is fully copied out before clearing the
 961                  * done flag
 962                  */
 963                 wmb();
 964                 hdr->flags = 0;
 965                 goto out;
 966         }
 967
 968         dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
 969                 "rx offset %p, ver %llu - %d payload received, buf size %d\n",
 970                 qp->rx_offset, hdr->ver, hdr->len, entry->len);
 971
 972         if (hdr->len <= entry->len)
 973                 ntb_rx_copy_task(qp, entry, offset);
 974         else {
 975                 ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
 976                                   &qp->rx_pend_q);
 977
 978                 /* Ensure that the data is fully copied out before clearing the
 979                  * done flag
 980                  */
 981                 wmb();
 982                 hdr->flags = 0;
 983                 qp->rx_err_oflow++;
 984                 dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
 985                         "RX overflow! Wanted %d got %d\n",
 986                         hdr->len, entry->len);
 987         }
 988
 989         qp->rx_bytes += hdr->len;
 990         qp->rx_pkts++;
 991
 992 out:
 993         qp->rx_offset += qp->rx_max_frame;
 994         if (qp->rx_offset + qp->rx_max_frame >= qp->rx_buff_end)
 995                 qp->rx_offset = qp->rx_buff_begin;
 996
 997         return 0;
 998 }
 999
1000 static void ntb_transport_rx(unsigned long data)
1001 {
1002         struct ntb_transport_qp *qp = (struct ntb_transport_qp *)data;
1003         int rc;
1004
1005         do {
1006                 rc = ntb_process_rxc(qp);
1007         } while (!rc);
1008 }
1009
1010 static void ntb_transport_rxc_db(void *data, int db_num)
1011 {
1012         struct ntb_transport_qp *qp = data;
1013
1014         dev_dbg(&ntb_query_pdev(qp->ndev)->dev, "%s: doorbell %d received\n",
1015                 __func__, db_num);
1016
1017         tasklet_schedule(&qp->rx_work);
1018 }
1019
1020 static void ntb_tx_copy_task(struct ntb_transport_qp *qp,
1021                              struct ntb_queue_entry *entry,
1022                              void *offset)
1023 {
1024         struct ntb_payload_header *hdr;
1025
1026         BUG_ON(offset < qp->tx_mw_begin ||
1027                offset + qp->tx_max_frame >= qp->tx_mw_end);
1028
1029         memcpy_toio(offset, entry->buf, entry->len);
1030
1031         hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
1032         hdr->len = entry->len;
1033         hdr->ver = qp->tx_pkts;
1034
1035         /* Ensure that the data is fully copied out before setting the flag */
1036         wmb();
1037         hdr->flags = entry->flags | DESC_DONE_FLAG;
1038
1039         ntb_ring_sdb(qp->ndev, qp->qp_num);
1040
1041         /* The entry length can only be zero if the packet is intended to be a
1042          * "link down" or similar.  Since no payload is being sent in these
1043          * cases, there is nothing to add to the completion queue.
1044          */
1045         if (entry->len > 0) {
1046                 qp->tx_bytes += entry->len;
1047
1048                 if (qp->tx_handler)
1049                         qp->tx_handler(qp, qp->cb_data, entry->cb_data,
1050                                        entry->len);
1051         }
1052
1053         ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q);
1054 }
1055
1056 static int ntb_process_tx(struct ntb_transport_qp *qp,
1057                           struct ntb_queue_entry *entry)
1058 {
1059         struct ntb_payload_header *hdr;
1060         void *offset;
1061
1062         offset = qp->tx_offset;
1063         hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
1064
1065         dev_dbg(&ntb_query_pdev(qp->ndev)->dev, "%lld - offset %p, tx %p, entry len %d flags %x buff %p\n",
1066                  qp->tx_pkts, offset, qp->tx_offset, entry->len, entry->flags,
1067                  entry->buf);
1068         if (hdr->flags) {
1069                 qp->tx_ring_full++;
1070                 return -EAGAIN;
1071         }
1072
1073         if (entry->len > qp->tx_max_frame - sizeof(struct ntb_payload_header)) {
1074                 if (qp->tx_handler)
1075                         qp->tx_handler(qp->cb_data, qp, NULL, -EIO);
1076
1077                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1078                              &qp->tx_free_q);
1079                 return 0;
1080         }
1081
1082         ntb_tx_copy_task(qp, entry, offset);
1083
1084         qp->tx_offset += qp->tx_max_frame;
1085         if (qp->tx_offset + qp->tx_max_frame >= qp->tx_mw_end)
1086                 qp->tx_offset = qp->tx_mw_begin;
1087
1088         qp->tx_pkts++;
1089
1090         return 0;
1091 }
1092
1093 static void ntb_send_link_down(struct ntb_transport_qp *qp)
1094 {
1095         struct pci_dev *pdev = ntb_query_pdev(qp->ndev);
1096         struct ntb_queue_entry *entry;
1097         int i, rc;
1098
1099         if (qp->qp_link == NTB_LINK_DOWN)
1100                 return;
1101
1102         qp->qp_link = NTB_LINK_DOWN;
1103         dev_info(&pdev->dev, "qp %d: Link Down\n", qp->qp_num);
1104
1105         for (i = 0; i < NTB_LINK_DOWN_TIMEOUT; i++) {
1106                 entry = ntb_list_rm(&qp->ntb_tx_free_q_lock,
1107                                          &qp->tx_free_q);
1108                 if (entry)
1109                         break;
1110                 msleep(100);
1111         }
1112
1113         if (!entry)
1114                 return;
1115
1116         entry->cb_data = NULL;
1117         entry->buf = NULL;
1118         entry->len = 0;
1119         entry->flags = LINK_DOWN_FLAG;
1120
1121         rc = ntb_process_tx(qp, entry);
1122         if (rc)
1123                 dev_err(&pdev->dev, "ntb: QP%d unable to send linkdown msg\n",
1124                         qp->qp_num);
1125 }
1126
1127 /**
1128  * ntb_transport_create_queue - Create a new NTB transport layer queue
1129  * @rx_handler: receive callback function
1130  * @tx_handler: transmit callback function
1131  * @event_handler: event callback function
1132  *
1133  * Create a new NTB transport layer queue and provide the queue with a callback
1134  * routine for both transmit and receive.  The receive callback routine will be
1135  * used to pass up data when the transport has received it on the queue.   The
1136  * transmit callback routine will be called when the transport has completed the
1137  * transmission of the data on the queue and the data is ready to be freed.
1138  *
1139  * RETURNS: pointer to newly created ntb_queue, NULL on error.
1140  */
1141 struct ntb_transport_qp *
1142 ntb_transport_create_queue(void *data, struct pci_dev *pdev,
1143                            const struct ntb_queue_handlers *handlers)
1144 {
1145         struct ntb_queue_entry *entry;
1146         struct ntb_transport_qp *qp;
1147         struct ntb_transport *nt;
1148         unsigned int free_queue;
1149         int rc, i;
1150
1151         nt = ntb_find_transport(pdev);
1152         if (!nt)
1153                 goto err;
1154
1155         free_queue = ffs(nt->qp_bitmap);
1156         if (!free_queue)
1157                 goto err;
1158
1159         /* decrement free_queue to make it zero based */
1160         free_queue--;
1161
1162         clear_bit(free_queue, &nt->qp_bitmap);
1163
1164         qp = &nt->qps[free_queue];
1165         qp->cb_data = data;
1166         qp->rx_handler = handlers->rx_handler;
1167         qp->tx_handler = handlers->tx_handler;
1168         qp->event_handler = handlers->event_handler;
1169
1170         for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
1171                 entry = kzalloc(sizeof(struct ntb_queue_entry), GFP_ATOMIC);
1172                 if (!entry)
1173                         goto err1;
1174
1175                 ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry,
1176                                   &qp->rx_free_q);
1177         }
1178
1179         for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
1180                 entry = kzalloc(sizeof(struct ntb_queue_entry), GFP_ATOMIC);
1181                 if (!entry)
1182                         goto err2;
1183
1184                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1185                                   &qp->tx_free_q);
1186         }
1187
1188         tasklet_init(&qp->rx_work, ntb_transport_rx, (unsigned long) qp);
1189
1190         rc = ntb_register_db_callback(qp->ndev, free_queue, qp,
1191                                       ntb_transport_rxc_db);
1192         if (rc)
1193                 goto err3;
1194
1195         dev_info(&pdev->dev, "NTB Transport QP %d created\n", qp->qp_num);
1196
1197         return qp;
1198
1199 err3:
1200         tasklet_disable(&qp->rx_work);
1201 err2:
1202         while ((entry =
1203                 ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1204                 kfree(entry);
1205 err1:
1206         while ((entry =
1207                 ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q)))
1208                 kfree(entry);
1209         set_bit(free_queue, &nt->qp_bitmap);
1210 err:
1211         return NULL;
1212 }
1213 EXPORT_SYMBOL_GPL(ntb_transport_create_queue);
1214
1215 /**
1216  * ntb_transport_free_queue - Frees NTB transport queue
1217  * @qp: NTB queue to be freed
1218  *
1219  * Frees NTB transport queue
1220  */
1221 void ntb_transport_free_queue(struct ntb_transport_qp *qp)
1222 {
1223         struct pci_dev *pdev = ntb_query_pdev(qp->ndev);
1224         struct ntb_queue_entry *entry;
1225
1226         if (!qp)
1227                 return;
1228
1229         cancel_delayed_work_sync(&qp->link_work);
1230
1231         ntb_unregister_db_callback(qp->ndev, qp->qp_num);
1232         tasklet_disable(&qp->rx_work);
1233
1234         while ((entry =
1235                 ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q)))
1236                 kfree(entry);
1237
1238         while ((entry =
1239                 ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q))) {
1240                 dev_warn(&pdev->dev, "Freeing item from a non-empty queue\n");
1241                 kfree(entry);
1242         }
1243
1244         while ((entry =
1245                 ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1246                 kfree(entry);
1247
1248         set_bit(qp->qp_num, &qp->transport->qp_bitmap);
1249
1250         dev_info(&pdev->dev, "NTB Transport QP %d freed\n", qp->qp_num);
1251 }
1252 EXPORT_SYMBOL_GPL(ntb_transport_free_queue);
1253
1254 /**
1255  * ntb_transport_rx_remove - Dequeues enqueued rx packet
1256  * @qp: NTB queue to be freed
1257  * @len: pointer to variable to write enqueued buffers length
1258  *
1259  * Dequeues unused buffers from receive queue.  Should only be used during
1260  * shutdown of qp.
1261  *
1262  * RETURNS: NULL error value on error, or void* for success.
1263  */
1264 void *ntb_transport_rx_remove(struct ntb_transport_qp *qp, unsigned int *len)
1265 {
1266         struct ntb_queue_entry *entry;
1267         void *buf;
1268
1269         if (!qp || qp->client_ready == NTB_LINK_UP)
1270                 return NULL;
1271
1272         entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q);
1273         if (!entry)
1274                 return NULL;
1275
1276         buf = entry->cb_data;
1277         *len = entry->len;
1278
1279         ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry,
1280                           &qp->rx_free_q);
1281
1282         return buf;
1283 }
1284 EXPORT_SYMBOL_GPL(ntb_transport_rx_remove);
1285
1286 /**
1287  * ntb_transport_rx_enqueue - Enqueue a new NTB queue entry
1288  * @qp: NTB transport layer queue the entry is to be enqueued on
1289  * @cb: per buffer pointer for callback function to use
1290  * @data: pointer to data buffer that incoming packets will be copied into
1291  * @len: length of the data buffer
1292  *
1293  * Enqueue a new receive buffer onto the transport queue into which a NTB
1294  * payload can be received into.
1295  *
1296  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
1297  */
1298 int ntb_transport_rx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
1299                              unsigned int len)
1300 {
1301         struct ntb_queue_entry *entry;
1302
1303         if (!qp)
1304                 return -EINVAL;
1305
1306         entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q);
1307         if (!entry)
1308                 return -ENOMEM;
1309
1310         entry->cb_data = cb;
1311         entry->buf = data;
1312         entry->len = len;
1313
1314         ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
1315                           &qp->rx_pend_q);
1316
1317         return 0;
1318 }
1319 EXPORT_SYMBOL_GPL(ntb_transport_rx_enqueue);
1320
1321 /**
1322  * ntb_transport_tx_enqueue - Enqueue a new NTB queue entry
1323  * @qp: NTB transport layer queue the entry is to be enqueued on
1324  * @cb: per buffer pointer for callback function to use
1325  * @data: pointer to data buffer that will be sent
1326  * @len: length of the data buffer
1327  *
1328  * Enqueue a new transmit buffer onto the transport queue from which a NTB
1329  * payload will be transmitted.  This assumes that a lock is behing held to
1330  * serialize access to the qp.
1331  *
1332  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
1333  */
1334 int ntb_transport_tx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
1335                              unsigned int len)
1336 {
1337         struct ntb_queue_entry *entry;
1338         int rc;
1339
1340         if (!qp || qp->qp_link != NTB_LINK_UP || !len)
1341                 return -EINVAL;
1342
1343         entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1344         if (!entry)
1345                 return -ENOMEM;
1346
1347         entry->cb_data = cb;
1348         entry->buf = data;
1349         entry->len = len;
1350         entry->flags = 0;
1351
1352         rc = ntb_process_tx(qp, entry);
1353         if (rc)
1354                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1355                              &qp->tx_free_q);
1356
1357         return rc;
1358 }
1359 EXPORT_SYMBOL_GPL(ntb_transport_tx_enqueue);
1360
1361 /**
1362  * ntb_transport_link_up - Notify NTB transport of client readiness to use queue
1363  * @qp: NTB transport layer queue to be enabled
1364  *
1365  * Notify NTB transport layer of client readiness to use queue
1366  */
1367 void ntb_transport_link_up(struct ntb_transport_qp *qp)
1368 {
1369         if (!qp)
1370                 return;
1371
1372         qp->client_ready = NTB_LINK_UP;
1373
1374         if (qp->transport->transport_link == NTB_LINK_UP)
1375                 schedule_delayed_work(&qp->link_work, 0);
1376 }
1377 EXPORT_SYMBOL_GPL(ntb_transport_link_up);
1378
1379 /**
1380  * ntb_transport_link_down - Notify NTB transport to no longer enqueue data
1381  * @qp: NTB transport layer queue to be disabled
1382  *
1383  * Notify NTB transport layer of client's desire to no longer receive data on
1384  * transport queue specified.  It is the client's responsibility to ensure all
1385  * entries on queue are purged or otherwise handled appropraitely.
1386  */
1387 void ntb_transport_link_down(struct ntb_transport_qp *qp)
1388 {
1389         struct pci_dev *pdev = ntb_query_pdev(qp->ndev);
1390         int rc, val;
1391
1392         if (!qp)
1393                 return;
1394
1395         qp->client_ready = NTB_LINK_DOWN;
1396
1397         rc = ntb_read_local_spad(qp->ndev, QP_LINKS, &val);
1398         if (rc) {
1399                 dev_err(&pdev->dev, "Error reading spad %d\n", QP_LINKS);
1400                 return;
1401         }
1402
1403         rc = ntb_write_remote_spad(qp->ndev, QP_LINKS,
1404                                    val & ~(1 << qp->qp_num));
1405         if (rc)
1406                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
1407                         val & ~(1 << qp->qp_num), QP_LINKS);
1408
1409         if (qp->qp_link == NTB_LINK_UP)
1410                 ntb_send_link_down(qp);
1411         else
1412                 cancel_delayed_work_sync(&qp->link_work);
1413 }
1414 EXPORT_SYMBOL_GPL(ntb_transport_link_down);
1415
1416 /**
1417  * ntb_transport_link_query - Query transport link state
1418  * @qp: NTB transport layer queue to be queried
1419  *
1420  * Query connectivity to the remote system of the NTB transport queue
1421  *
1422  * RETURNS: true for link up or false for link down
1423  */
1424 bool ntb_transport_link_query(struct ntb_transport_qp *qp)
1425 {
1426         return qp->qp_link == NTB_LINK_UP;
1427 }
1428 EXPORT_SYMBOL_GPL(ntb_transport_link_query);
1429
1430 /**
1431  * ntb_transport_qp_num - Query the qp number
1432  * @qp: NTB transport layer queue to be queried
1433  *
1434  * Query qp number of the NTB transport queue
1435  *
1436  * RETURNS: a zero based number specifying the qp number
1437  */
1438 unsigned char ntb_transport_qp_num(struct ntb_transport_qp *qp)
1439 {
1440         return qp->qp_num;
1441 }
1442 EXPORT_SYMBOL_GPL(ntb_transport_qp_num);
1443
1444 /**
1445  * ntb_transport_max_size - Query the max payload size of a qp
1446  * @qp: NTB transport layer queue to be queried
1447  *
1448  * Query the maximum payload size permissible on the given qp
1449  *
1450  * RETURNS: the max payload size of a qp
1451  */
1452 unsigned int ntb_transport_max_size(struct ntb_transport_qp *qp)
1453 {
1454         return qp->tx_max_frame - sizeof(struct ntb_payload_header);
1455 }
1456 EXPORT_SYMBOL_GPL(ntb_transport_max_size);