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   2
  62
  63 static unsigned int transport_mtu = 0x401E;
  64 module_param(transport_mtu, uint, 0644);
  65 MODULE_PARM_DESC(transport_mtu, "Maximum size of NTB transport packets");
  66
  67 static unsigned char max_num_clients = 2;
  68 module_param(max_num_clients, byte, 0644);
  69 MODULE_PARM_DESC(max_num_clients, "Maximum number of NTB transport clients");
  70
  71 struct ntb_queue_entry {
  72         /* ntb_queue list reference */
  73         struct list_head entry;
  74         /* pointers to data to be transfered */
  75         void *cb_data;
  76         void *buf;
  77         unsigned int len;
  78         unsigned int flags;
  79 };
  80
  81 struct ntb_rx_info {
  82         unsigned int entry;
  83 };
  84
  85 struct ntb_transport_qp {
  86         struct ntb_transport *transport;
  87         struct ntb_device *ndev;
  88         void *cb_data;
  89
  90         bool client_ready;
  91         bool qp_link;
  92         u8 qp_num;      /* Only 64 QP's are allowed.  0-63 */
  93
  94         struct ntb_rx_info __iomem *rx_info;
  95         struct ntb_rx_info *remote_rx_info;
  96
  97         void (*tx_handler) (struct ntb_transport_qp *qp, void *qp_data,
  98                             void *data, int len);
  99         struct list_head tx_free_q;
 100         spinlock_t ntb_tx_free_q_lock;
 101         void __iomem *tx_mw;
 102         unsigned int tx_index;
 103         unsigned int tx_max_entry;
 104         unsigned int tx_max_frame;
 105
 106         void (*rx_handler) (struct ntb_transport_qp *qp, void *qp_data,
 107                             void *data, int len);
 108         struct tasklet_struct rx_work;
 109         struct list_head rx_pend_q;
 110         struct list_head rx_free_q;
 111         spinlock_t ntb_rx_pend_q_lock;
 112         spinlock_t ntb_rx_free_q_lock;
 113         void *rx_buff;
 114         unsigned int rx_index;
 115         unsigned int rx_max_entry;
 116         unsigned int rx_max_frame;
 117
 118         void (*event_handler) (void *data, int status);
 119         struct delayed_work link_work;
 120         struct work_struct link_cleanup;
 121
 122         struct dentry *debugfs_dir;
 123         struct dentry *debugfs_stats;
 124
 125         /* Stats */
 126         u64 rx_bytes;
 127         u64 rx_pkts;
 128         u64 rx_ring_empty;
 129         u64 rx_err_no_buf;
 130         u64 rx_err_oflow;
 131         u64 rx_err_ver;
 132         u64 tx_bytes;
 133         u64 tx_pkts;
 134         u64 tx_ring_full;
 135 };
 136
 137 struct ntb_transport_mw {
 138         size_t size;
 139         void *virt_addr;
 140         dma_addr_t dma_addr;
 141 };
 142
 143 struct ntb_transport_client_dev {
 144         struct list_head entry;
 145         struct device dev;
 146 };
 147
 148 struct ntb_transport {
 149         struct list_head entry;
 150         struct list_head client_devs;
 151
 152         struct ntb_device *ndev;
 153         struct ntb_transport_mw mw[NTB_NUM_MW];
 154         struct ntb_transport_qp *qps;
 155         unsigned int max_qps;
 156         unsigned long qp_bitmap;
 157         bool transport_link;
 158         struct delayed_work link_work;
 159         struct work_struct link_cleanup;
 160         struct dentry *debugfs_dir;
 161 };
 162
 163 enum {
 164         DESC_DONE_FLAG = 1 << 0,
 165         LINK_DOWN_FLAG = 1 << 1,
 166 };
 167
 168 struct ntb_payload_header {
 169         unsigned int ver;
 170         unsigned int len;
 171         unsigned int flags;
 172 };
 173
 174 enum {
 175         VERSION = 0,
 176         MW0_SZ,
 177         MW1_SZ,
 178         NUM_QPS,
 179         QP_LINKS,
 180         MAX_SPAD,
 181 };
 182
 183 #define QP_TO_MW(qp)            ((qp) % NTB_NUM_MW)
 184 #define NTB_QP_DEF_NUM_ENTRIES  100
 185 #define NTB_LINK_DOWN_TIMEOUT   10
 186
 187 static int ntb_match_bus(struct device *dev, struct device_driver *drv)
 188 {
 189         return !strncmp(dev_name(dev), drv->name, strlen(drv->name));
 190 }
 191
 192 static int ntb_client_probe(struct device *dev)
 193 {
 194         const struct ntb_client *drv = container_of(dev->driver,
 195                                                     struct ntb_client, driver);
 196         struct pci_dev *pdev = container_of(dev->parent, struct pci_dev, dev);
 197         int rc = -EINVAL;
 198
 199         get_device(dev);
 200         if (drv && drv->probe)
 201                 rc = drv->probe(pdev);
 202         if (rc)
 203                 put_device(dev);
 204
 205         return rc;
 206 }
 207
 208 static int ntb_client_remove(struct device *dev)
 209 {
 210         const struct ntb_client *drv = container_of(dev->driver,
 211                                                     struct ntb_client, driver);
 212         struct pci_dev *pdev = container_of(dev->parent, struct pci_dev, dev);
 213
 214         if (drv && drv->remove)
 215                 drv->remove(pdev);
 216
 217         put_device(dev);
 218
 219         return 0;
 220 }
 221
 222 static struct bus_type ntb_bus_type = {
 223         .name = "ntb_bus",
 224         .match = ntb_match_bus,
 225         .probe = ntb_client_probe,
 226         .remove = ntb_client_remove,
 227 };
 228
 229 static LIST_HEAD(ntb_transport_list);
 230
 231 static int ntb_bus_init(struct ntb_transport *nt)
 232 {
 233         if (list_empty(&ntb_transport_list)) {
 234                 int rc = bus_register(&ntb_bus_type);
 235                 if (rc)
 236                         return rc;
 237         }
 238
 239         list_add(&nt->entry, &ntb_transport_list);
 240
 241         return 0;
 242 }
 243
 244 static void ntb_bus_remove(struct ntb_transport *nt)
 245 {
 246         struct ntb_transport_client_dev *client_dev, *cd;
 247
 248         list_for_each_entry_safe(client_dev, cd, &nt->client_devs, entry) {
 249                 dev_err(client_dev->dev.parent, "%s still attached to bus, removing\n",
 250                         dev_name(&client_dev->dev));
 251                 list_del(&client_dev->entry);
 252                 device_unregister(&client_dev->dev);
 253         }
 254
 255         list_del(&nt->entry);
 256
 257         if (list_empty(&ntb_transport_list))
 258                 bus_unregister(&ntb_bus_type);
 259 }
 260
 261 static void ntb_client_release(struct device *dev)
 262 {
 263         struct ntb_transport_client_dev *client_dev;
 264         client_dev = container_of(dev, struct ntb_transport_client_dev, dev);
 265
 266         kfree(client_dev);
 267 }
 268
 269 /**
 270  * ntb_unregister_client_dev - Unregister NTB client device
 271  * @device_name: Name of NTB client device
 272  *
 273  * Unregister an NTB client device with the NTB transport layer
 274  */
 275 void ntb_unregister_client_dev(char *device_name)
 276 {
 277         struct ntb_transport_client_dev *client, *cd;
 278         struct ntb_transport *nt;
 279
 280         list_for_each_entry(nt, &ntb_transport_list, entry)
 281                 list_for_each_entry_safe(client, cd, &nt->client_devs, entry)
 282                         if (!strncmp(dev_name(&client->dev), device_name,
 283                                      strlen(device_name))) {
 284                                 list_del(&client->entry);
 285                                 device_unregister(&client->dev);
 286                         }
 287 }
 288 EXPORT_SYMBOL_GPL(ntb_unregister_client_dev);
 289
 290 /**
 291  * ntb_register_client_dev - Register NTB client device
 292  * @device_name: Name of NTB client device
 293  *
 294  * Register an NTB client device with the NTB transport layer
 295  */
 296 int ntb_register_client_dev(char *device_name)
 297 {
 298         struct ntb_transport_client_dev *client_dev;
 299         struct ntb_transport *nt;
 300         int rc;
 301
 302         if (list_empty(&ntb_transport_list))
 303                 return -ENODEV;
 304
 305         list_for_each_entry(nt, &ntb_transport_list, entry) {
 306                 struct device *dev;
 307
 308                 client_dev = kzalloc(sizeof(struct ntb_transport_client_dev),
 309                                      GFP_KERNEL);
 310                 if (!client_dev) {
 311                         rc = -ENOMEM;
 312                         goto err;
 313                 }
 314
 315                 dev = &client_dev->dev;
 316
 317                 /* setup and register client devices */
 318                 dev_set_name(dev, "%s", device_name);
 319                 dev->bus = &ntb_bus_type;
 320                 dev->release = ntb_client_release;
 321                 dev->parent = &ntb_query_pdev(nt->ndev)->dev;
 322
 323                 rc = device_register(dev);
 324                 if (rc) {
 325                         kfree(client_dev);
 326                         goto err;
 327                 }
 328
 329                 list_add_tail(&client_dev->entry, &nt->client_devs);
 330         }
 331
 332         return 0;
 333
 334 err:
 335         ntb_unregister_client_dev(device_name);
 336
 337         return rc;
 338 }
 339 EXPORT_SYMBOL_GPL(ntb_register_client_dev);
 340
 341 /**
 342  * ntb_register_client - Register NTB client driver
 343  * @drv: NTB client driver to be registered
 344  *
 345  * Register an NTB client driver with the NTB transport layer
 346  *
 347  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 348  */
 349 int ntb_register_client(struct ntb_client *drv)
 350 {
 351         drv->driver.bus = &ntb_bus_type;
 352
 353         if (list_empty(&ntb_transport_list))
 354                 return -ENODEV;
 355
 356         return driver_register(&drv->driver);
 357 }
 358 EXPORT_SYMBOL_GPL(ntb_register_client);
 359
 360 /**
 361  * ntb_unregister_client - Unregister NTB client driver
 362  * @drv: NTB client driver to be unregistered
 363  *
 364  * Unregister an NTB client driver with the NTB transport layer
 365  *
 366  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 367  */
 368 void ntb_unregister_client(struct ntb_client *drv)
 369 {
 370         driver_unregister(&drv->driver);
 371 }
 372 EXPORT_SYMBOL_GPL(ntb_unregister_client);
 373
 374 static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count,
 375                             loff_t *offp)
 376 {
 377         struct ntb_transport_qp *qp;
 378         char *buf;
 379         ssize_t ret, out_offset, out_count;
 380
 381         out_count = 600;
 382
 383         buf = kmalloc(out_count, GFP_KERNEL);
 384         if (!buf)
 385                 return -ENOMEM;
 386
 387         qp = filp->private_data;
 388         out_offset = 0;
 389         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 390                                "NTB QP stats\n");
 391         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 392                                "rx_bytes - \t%llu\n", qp->rx_bytes);
 393         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 394                                "rx_pkts - \t%llu\n", qp->rx_pkts);
 395         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 396                                "rx_ring_empty - %llu\n", qp->rx_ring_empty);
 397         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 398                                "rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
 399         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 400                                "rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
 401         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 402                                "rx_err_ver - \t%llu\n", qp->rx_err_ver);
 403         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 404                                "rx_buff - \t%p\n", qp->rx_buff);
 405         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 406                                "rx_index - \t%u\n", qp->rx_index);
 407         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 408                                "rx_max_entry - \t%u\n", qp->rx_max_entry);
 409
 410         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 411                                "tx_bytes - \t%llu\n", qp->tx_bytes);
 412         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 413                                "tx_pkts - \t%llu\n", qp->tx_pkts);
 414         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 415                                "tx_ring_full - \t%llu\n", qp->tx_ring_full);
 416         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 417                                "tx_mw - \t%p\n", qp->tx_mw);
 418         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 419                                "tx_index - \t%u\n", qp->tx_index);
 420         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 421                                "tx_max_entry - \t%u\n", qp->tx_max_entry);
 422
 423         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 424                                "\nQP Link %s\n", (qp->qp_link == NTB_LINK_UP) ?
 425                                "Up" : "Down");
 426         if (out_offset > out_count)
 427                 out_offset = out_count;
 428
 429         ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
 430         kfree(buf);
 431         return ret;
 432 }
 433
 434 static const struct file_operations ntb_qp_debugfs_stats = {
 435         .owner = THIS_MODULE,
 436         .open = simple_open,
 437         .read = debugfs_read,
 438 };
 439
 440 static void ntb_list_add(spinlock_t *lock, struct list_head *entry,
 441                          struct list_head *list)
 442 {
 443         unsigned long flags;
 444
 445         spin_lock_irqsave(lock, flags);
 446         list_add_tail(entry, list);
 447         spin_unlock_irqrestore(lock, flags);
 448 }
 449
 450 static struct ntb_queue_entry *ntb_list_rm(spinlock_t *lock,
 451                                                 struct list_head *list)
 452 {
 453         struct ntb_queue_entry *entry;
 454         unsigned long flags;
 455
 456         spin_lock_irqsave(lock, flags);
 457         if (list_empty(list)) {
 458                 entry = NULL;
 459                 goto out;
 460         }
 461         entry = list_first_entry(list, struct ntb_queue_entry, entry);
 462         list_del(&entry->entry);
 463 out:
 464         spin_unlock_irqrestore(lock, flags);
 465
 466         return entry;
 467 }
 468
 469 static void ntb_transport_setup_qp_mw(struct ntb_transport *nt,
 470                                       unsigned int qp_num)
 471 {
 472         struct ntb_transport_qp *qp = &nt->qps[qp_num];
 473         unsigned int rx_size, num_qps_mw;
 474         u8 mw_num = QP_TO_MW(qp_num);
 475         unsigned int i;
 476
 477         WARN_ON(nt->mw[mw_num].virt_addr == NULL);
 478
 479         if (nt->max_qps % NTB_NUM_MW && mw_num < nt->max_qps % NTB_NUM_MW)
 480                 num_qps_mw = nt->max_qps / NTB_NUM_MW + 1;
 481         else
 482                 num_qps_mw = nt->max_qps / NTB_NUM_MW;
 483
 484         rx_size = (unsigned int) nt->mw[mw_num].size / num_qps_mw;
 485         qp->remote_rx_info = nt->mw[mw_num].virt_addr +
 486                              (qp_num / NTB_NUM_MW * rx_size);
 487         rx_size -= sizeof(struct ntb_rx_info);
 488
 489         qp->rx_buff = qp->remote_rx_info + sizeof(struct ntb_rx_info);
 490         qp->rx_max_frame = min(transport_mtu, rx_size);
 491         qp->rx_max_entry = rx_size / qp->rx_max_frame;
 492         qp->rx_index = 0;
 493
 494         qp->remote_rx_info->entry = qp->rx_max_entry;
 495
 496         /* setup the hdr offsets with 0's */
 497         for (i = 0; i < qp->rx_max_entry; i++) {
 498                 void *offset = qp->rx_buff + qp->rx_max_frame * (i + 1) -
 499                                sizeof(struct ntb_payload_header);
 500                 memset(offset, 0, sizeof(struct ntb_payload_header));
 501         }
 502
 503         qp->rx_pkts = 0;
 504         qp->tx_pkts = 0;
 505 }
 506
 507 static int ntb_set_mw(struct ntb_transport *nt, int num_mw, unsigned int size)
 508 {
 509         struct ntb_transport_mw *mw = &nt->mw[num_mw];
 510         struct pci_dev *pdev = ntb_query_pdev(nt->ndev);
 511
 512         /* Alloc memory for receiving data.  Must be 4k aligned */
 513         mw->size = ALIGN(size, 4096);
 514
 515         mw->virt_addr = dma_alloc_coherent(&pdev->dev, mw->size, &mw->dma_addr,
 516                                            GFP_KERNEL);
 517         if (!mw->virt_addr) {
 518                 dev_err(&pdev->dev, "Unable to allocate MW buffer of size %d\n",
 519                        (int) mw->size);
 520                 return -ENOMEM;
 521         }
 522
 523         /* Notify HW the memory location of the receive buffer */
 524         ntb_set_mw_addr(nt->ndev, num_mw, mw->dma_addr);
 525
 526         return 0;
 527 }
 528
 529 static void ntb_qp_link_cleanup(struct work_struct *work)
 530 {
 531         struct ntb_transport_qp *qp = container_of(work,
 532                                                    struct ntb_transport_qp,
 533                                                    link_cleanup);
 534         struct ntb_transport *nt = qp->transport;
 535         struct pci_dev *pdev = ntb_query_pdev(nt->ndev);
 536
 537         if (qp->qp_link == NTB_LINK_DOWN) {
 538                 cancel_delayed_work_sync(&qp->link_work);
 539                 return;
 540         }
 541
 542         if (qp->event_handler)
 543                 qp->event_handler(qp->cb_data, NTB_LINK_DOWN);
 544
 545         dev_info(&pdev->dev, "qp %d: Link Down\n", qp->qp_num);
 546         qp->qp_link = NTB_LINK_DOWN;
 547
 548         if (nt->transport_link == NTB_LINK_UP)
 549                 schedule_delayed_work(&qp->link_work,
 550                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 551 }
 552
 553 static void ntb_qp_link_down(struct ntb_transport_qp *qp)
 554 {
 555         schedule_work(&qp->link_cleanup);
 556 }
 557
 558 static void ntb_transport_link_cleanup(struct work_struct *work)
 559 {
 560         struct ntb_transport *nt = container_of(work, struct ntb_transport,
 561                                                 link_cleanup);
 562         int i;
 563
 564         if (nt->transport_link == NTB_LINK_DOWN)
 565                 cancel_delayed_work_sync(&nt->link_work);
 566         else
 567                 nt->transport_link = NTB_LINK_DOWN;
 568
 569         /* Pass along the info to any clients */
 570         for (i = 0; i < nt->max_qps; i++)
 571                 if (!test_bit(i, &nt->qp_bitmap))
 572                         ntb_qp_link_down(&nt->qps[i]);
 573
 574         /* The scratchpad registers keep the values if the remote side
 575          * goes down, blast them now to give them a sane value the next
 576          * time they are accessed
 577          */
 578         for (i = 0; i < MAX_SPAD; i++)
 579                 ntb_write_local_spad(nt->ndev, i, 0);
 580 }
 581
 582 static void ntb_transport_event_callback(void *data, enum ntb_hw_event event)
 583 {
 584         struct ntb_transport *nt = data;
 585
 586         switch (event) {
 587         case NTB_EVENT_HW_LINK_UP:
 588                 schedule_delayed_work(&nt->link_work, 0);
 589                 break;
 590         case NTB_EVENT_HW_LINK_DOWN:
 591                 schedule_work(&nt->link_cleanup);
 592                 break;
 593         default:
 594                 BUG();
 595         }
 596 }
 597
 598 static void ntb_transport_link_work(struct work_struct *work)
 599 {
 600         struct ntb_transport *nt = container_of(work, struct ntb_transport,
 601                                                 link_work.work);
 602         struct ntb_device *ndev = nt->ndev;
 603         struct pci_dev *pdev = ntb_query_pdev(ndev);
 604         u32 val;
 605         int rc, i;
 606
 607         /* send the local info */
 608         rc = ntb_write_remote_spad(ndev, VERSION, NTB_TRANSPORT_VERSION);
 609         if (rc) {
 610                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
 611                         0, VERSION);
 612                 goto out;
 613         }
 614
 615         rc = ntb_write_remote_spad(ndev, MW0_SZ, ntb_get_mw_size(ndev, 0));
 616         if (rc) {
 617                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
 618                         (u32) ntb_get_mw_size(ndev, 0), MW0_SZ);
 619                 goto out;
 620         }
 621
 622         rc = ntb_write_remote_spad(ndev, MW1_SZ, ntb_get_mw_size(ndev, 1));
 623         if (rc) {
 624                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
 625                         (u32) ntb_get_mw_size(ndev, 1), MW1_SZ);
 626                 goto out;
 627         }
 628
 629         rc = ntb_write_remote_spad(ndev, NUM_QPS, nt->max_qps);
 630         if (rc) {
 631                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
 632                         nt->max_qps, NUM_QPS);
 633                 goto out;
 634         }
 635
 636         rc = ntb_read_local_spad(nt->ndev, QP_LINKS, &val);
 637         if (rc) {
 638                 dev_err(&pdev->dev, "Error reading spad %d\n", QP_LINKS);
 639                 goto out;
 640         }
 641
 642         rc = ntb_write_remote_spad(ndev, QP_LINKS, val);
 643         if (rc) {
 644                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
 645                         val, QP_LINKS);
 646                 goto out;
 647         }
 648
 649         /* Query the remote side for its info */
 650         rc = ntb_read_remote_spad(ndev, VERSION, &val);
 651         if (rc) {
 652                 dev_err(&pdev->dev, "Error reading remote spad %d\n", VERSION);
 653                 goto out;
 654         }
 655
 656         if (val != NTB_TRANSPORT_VERSION)
 657                 goto out;
 658         dev_dbg(&pdev->dev, "Remote version = %d\n", val);
 659
 660         rc = ntb_read_remote_spad(ndev, NUM_QPS, &val);
 661         if (rc) {
 662                 dev_err(&pdev->dev, "Error reading remote spad %d\n", NUM_QPS);
 663                 goto out;
 664         }
 665
 666         if (val != nt->max_qps)
 667                 goto out;
 668         dev_dbg(&pdev->dev, "Remote max number of qps = %d\n", val);
 669
 670         rc = ntb_read_remote_spad(ndev, MW0_SZ, &val);
 671         if (rc) {
 672                 dev_err(&pdev->dev, "Error reading remote spad %d\n", MW0_SZ);
 673                 goto out;
 674         }
 675
 676         if (!val)
 677                 goto out;
 678         dev_dbg(&pdev->dev, "Remote MW0 size = %d\n", val);
 679
 680         rc = ntb_set_mw(nt, 0, val);
 681         if (rc)
 682                 goto out;
 683
 684         rc = ntb_read_remote_spad(ndev, MW1_SZ, &val);
 685         if (rc) {
 686                 dev_err(&pdev->dev, "Error reading remote spad %d\n", MW1_SZ);
 687                 goto out;
 688         }
 689
 690         if (!val)
 691                 goto out;
 692         dev_dbg(&pdev->dev, "Remote MW1 size = %d\n", val);
 693
 694         rc = ntb_set_mw(nt, 1, val);
 695         if (rc)
 696                 goto out;
 697
 698         nt->transport_link = NTB_LINK_UP;
 699
 700         for (i = 0; i < nt->max_qps; i++) {
 701                 struct ntb_transport_qp *qp = &nt->qps[i];
 702
 703                 ntb_transport_setup_qp_mw(nt, i);
 704
 705                 if (qp->client_ready == NTB_LINK_UP)
 706                         schedule_delayed_work(&qp->link_work, 0);
 707         }
 708
 709         return;
 710
 711 out:
 712         if (ntb_hw_link_status(ndev))
 713                 schedule_delayed_work(&nt->link_work,
 714                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 715 }
 716
 717 static void ntb_qp_link_work(struct work_struct *work)
 718 {
 719         struct ntb_transport_qp *qp = container_of(work,
 720                                                    struct ntb_transport_qp,
 721                                                    link_work.work);
 722         struct pci_dev *pdev = ntb_query_pdev(qp->ndev);
 723         struct ntb_transport *nt = qp->transport;
 724         int rc, val;
 725
 726         WARN_ON(nt->transport_link != NTB_LINK_UP);
 727
 728         rc = ntb_read_local_spad(nt->ndev, QP_LINKS, &val);
 729         if (rc) {
 730                 dev_err(&pdev->dev, "Error reading spad %d\n", QP_LINKS);
 731                 return;
 732         }
 733
 734         rc = ntb_write_remote_spad(nt->ndev, QP_LINKS, val | 1 << qp->qp_num);
 735         if (rc)
 736                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
 737                         val | 1 << qp->qp_num, QP_LINKS);
 738
 739         /* query remote spad for qp ready bits */
 740         rc = ntb_read_remote_spad(nt->ndev, QP_LINKS, &val);
 741         if (rc)
 742                 dev_err(&pdev->dev, "Error reading remote spad %d\n", QP_LINKS);
 743
 744         dev_dbg(&pdev->dev, "Remote QP link status = %x\n", val);
 745
 746         /* See if the remote side is up */
 747         if (1 << qp->qp_num & val) {
 748                 qp->qp_link = NTB_LINK_UP;
 749
 750                 dev_info(&pdev->dev, "qp %d: Link Up\n", qp->qp_num);
 751                 if (qp->event_handler)
 752                         qp->event_handler(qp->cb_data, NTB_LINK_UP);
 753         } else if (nt->transport_link == NTB_LINK_UP)
 754                 schedule_delayed_work(&qp->link_work,
 755                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 756 }
 757
 758 static void ntb_transport_init_queue(struct ntb_transport *nt,
 759                                      unsigned int qp_num)
 760 {
 761         struct ntb_transport_qp *qp;
 762         unsigned int num_qps_mw, tx_size;
 763         u8 mw_num = QP_TO_MW(qp_num);
 764
 765         qp = &nt->qps[qp_num];
 766         qp->qp_num = qp_num;
 767         qp->transport = nt;
 768         qp->ndev = nt->ndev;
 769         qp->qp_link = NTB_LINK_DOWN;
 770         qp->client_ready = NTB_LINK_DOWN;
 771         qp->event_handler = NULL;
 772
 773         if (nt->max_qps % NTB_NUM_MW && mw_num < nt->max_qps % NTB_NUM_MW)
 774                 num_qps_mw = nt->max_qps / NTB_NUM_MW + 1;
 775         else
 776                 num_qps_mw = nt->max_qps / NTB_NUM_MW;
 777
 778         tx_size = (unsigned int) ntb_get_mw_size(qp->ndev, mw_num) / num_qps_mw;
 779         qp->rx_info = ntb_get_mw_vbase(nt->ndev, mw_num) +
 780                       (qp_num / NTB_NUM_MW * tx_size);
 781         tx_size -= sizeof(struct ntb_rx_info);
 782
 783         qp->tx_mw = qp->rx_info + sizeof(struct ntb_rx_info);
 784         qp->tx_max_frame = min(transport_mtu, tx_size);
 785         qp->tx_max_entry = tx_size / qp->tx_max_frame;
 786         qp->tx_index = 0;
 787
 788         if (nt->debugfs_dir) {
 789                 char debugfs_name[4];
 790
 791                 snprintf(debugfs_name, 4, "qp%d", qp_num);
 792                 qp->debugfs_dir = debugfs_create_dir(debugfs_name,
 793                                                      nt->debugfs_dir);
 794
 795                 qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR,
 796                                                         qp->debugfs_dir, qp,
 797                                                         &ntb_qp_debugfs_stats);
 798         }
 799
 800         INIT_DELAYED_WORK(&qp->link_work, ntb_qp_link_work);
 801         INIT_WORK(&qp->link_cleanup, ntb_qp_link_cleanup);
 802
 803         spin_lock_init(&qp->ntb_rx_pend_q_lock);
 804         spin_lock_init(&qp->ntb_rx_free_q_lock);
 805         spin_lock_init(&qp->ntb_tx_free_q_lock);
 806
 807         INIT_LIST_HEAD(&qp->rx_pend_q);
 808         INIT_LIST_HEAD(&qp->rx_free_q);
 809         INIT_LIST_HEAD(&qp->tx_free_q);
 810 }
 811
 812 int ntb_transport_init(struct pci_dev *pdev)
 813 {
 814         struct ntb_transport *nt;
 815         int rc, i;
 816
 817         nt = kzalloc(sizeof(struct ntb_transport), GFP_KERNEL);
 818         if (!nt)
 819                 return -ENOMEM;
 820
 821         if (debugfs_initialized())
 822                 nt->debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
 823         else
 824                 nt->debugfs_dir = NULL;
 825
 826         nt->ndev = ntb_register_transport(pdev, nt);
 827         if (!nt->ndev) {
 828                 rc = -EIO;
 829                 goto err;
 830         }
 831
 832         nt->max_qps = min(nt->ndev->max_cbs, max_num_clients);
 833
 834         nt->qps = kcalloc(nt->max_qps, sizeof(struct ntb_transport_qp),
 835                           GFP_KERNEL);
 836         if (!nt->qps) {
 837                 rc = -ENOMEM;
 838                 goto err1;
 839         }
 840
 841         nt->qp_bitmap = ((u64) 1 << nt->max_qps) - 1;
 842
 843         for (i = 0; i < nt->max_qps; i++)
 844                 ntb_transport_init_queue(nt, i);
 845
 846         INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work);
 847         INIT_WORK(&nt->link_cleanup, ntb_transport_link_cleanup);
 848
 849         rc = ntb_register_event_callback(nt->ndev,
 850                                          ntb_transport_event_callback);
 851         if (rc)
 852                 goto err2;
 853
 854         INIT_LIST_HEAD(&nt->client_devs);
 855         rc = ntb_bus_init(nt);
 856         if (rc)
 857                 goto err3;
 858
 859         if (ntb_hw_link_status(nt->ndev))
 860                 schedule_delayed_work(&nt->link_work, 0);
 861
 862         return 0;
 863
 864 err3:
 865         ntb_unregister_event_callback(nt->ndev);
 866 err2:
 867         kfree(nt->qps);
 868 err1:
 869         ntb_unregister_transport(nt->ndev);
 870 err:
 871         debugfs_remove_recursive(nt->debugfs_dir);
 872         kfree(nt);
 873         return rc;
 874 }
 875
 876 void ntb_transport_free(void *transport)
 877 {
 878         struct ntb_transport *nt = transport;
 879         struct pci_dev *pdev;
 880         int i;
 881
 882         nt->transport_link = NTB_LINK_DOWN;
 883
 884         /* verify that all the qp's are freed */
 885         for (i = 0; i < nt->max_qps; i++)
 886                 if (!test_bit(i, &nt->qp_bitmap))
 887                         ntb_transport_free_queue(&nt->qps[i]);
 888
 889         ntb_bus_remove(nt);
 890
 891         cancel_delayed_work_sync(&nt->link_work);
 892
 893         debugfs_remove_recursive(nt->debugfs_dir);
 894
 895         ntb_unregister_event_callback(nt->ndev);
 896
 897         pdev = ntb_query_pdev(nt->ndev);
 898
 899         for (i = 0; i < NTB_NUM_MW; i++)
 900                 if (nt->mw[i].virt_addr)
 901                         dma_free_coherent(&pdev->dev, nt->mw[i].size,
 902                                           nt->mw[i].virt_addr,
 903                                           nt->mw[i].dma_addr);
 904
 905         kfree(nt->qps);
 906         ntb_unregister_transport(nt->ndev);
 907         kfree(nt);
 908 }
 909
 910 static void ntb_rx_copy_task(struct ntb_transport_qp *qp,
 911                              struct ntb_queue_entry *entry, void *offset)
 912 {
 913         void *cb_data = entry->cb_data;
 914         unsigned int len = entry->len;
 915
 916         memcpy(entry->buf, offset, entry->len);
 917
 918         ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry, &qp->rx_free_q);
 919
 920         if (qp->rx_handler && qp->client_ready == NTB_LINK_UP)
 921                 qp->rx_handler(qp, qp->cb_data, cb_data, len);
 922 }
 923
 924 static int ntb_process_rxc(struct ntb_transport_qp *qp)
 925 {
 926         struct ntb_payload_header *hdr;
 927         struct ntb_queue_entry *entry;
 928         void *offset;
 929
 930         offset = qp->rx_buff + qp->rx_max_frame * qp->rx_index;
 931         hdr = offset + qp->rx_max_frame - sizeof(struct ntb_payload_header);
 932
 933         entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q);
 934         if (!entry) {
 935                 dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
 936                         "no buffer - HDR ver %u, len %d, flags %x\n",
 937                         hdr->ver, hdr->len, hdr->flags);
 938                 qp->rx_err_no_buf++;
 939                 return -ENOMEM;
 940         }
 941
 942         if (!(hdr->flags & DESC_DONE_FLAG)) {
 943                 ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
 944                              &qp->rx_pend_q);
 945                 qp->rx_ring_empty++;
 946                 return -EAGAIN;
 947         }
 948
 949         if (hdr->ver != (u32) qp->rx_pkts) {
 950                 dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
 951                         "qp %d: version mismatch, expected %llu - got %u\n",
 952                         qp->qp_num, qp->rx_pkts, hdr->ver);
 953                 ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
 954                              &qp->rx_pend_q);
 955                 qp->rx_err_ver++;
 956                 return -EIO;
 957         }
 958
 959         if (hdr->flags & LINK_DOWN_FLAG) {
 960                 ntb_qp_link_down(qp);
 961
 962                 ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
 963                              &qp->rx_pend_q);
 964                 goto out;
 965         }
 966
 967         dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
 968                 "rx offset %u, ver %u - %d payload received, buf size %d\n",
 969                 qp->rx_index, hdr->ver, hdr->len, entry->len);
 970
 971         if (hdr->len <= entry->len) {
 972                 entry->len = hdr->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                 qp->rx_err_oflow++;
 979                 dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
 980                         "RX overflow! Wanted %d got %d\n",
 981                         hdr->len, entry->len);
 982         }
 983
 984         qp->rx_bytes += hdr->len;
 985         qp->rx_pkts++;
 986
 987 out:
 988         /* Ensure that the data is fully copied out before clearing the flag */
 989         wmb();
 990         hdr->flags = 0;
 991         iowrite32(qp->rx_index, &qp->rx_info->entry);
 992
 993         qp->rx_index++;
 994         qp->rx_index %= qp->rx_max_entry;
 995
 996         return 0;
 997 }
 998
 999 static void ntb_transport_rx(unsigned long data)
1000 {
1001         struct ntb_transport_qp *qp = (struct ntb_transport_qp *)data;
1002         int rc;
1003
1004         do {
1005                 rc = ntb_process_rxc(qp);
1006         } while (!rc);
1007 }
1008
1009 static void ntb_transport_rxc_db(void *data, int db_num)
1010 {
1011         struct ntb_transport_qp *qp = data;
1012
1013         dev_dbg(&ntb_query_pdev(qp->ndev)->dev, "%s: doorbell %d received\n",
1014                 __func__, db_num);
1015
1016         tasklet_schedule(&qp->rx_work);
1017 }
1018
1019 static void ntb_tx_copy_task(struct ntb_transport_qp *qp,
1020                              struct ntb_queue_entry *entry,
1021                              void __iomem *offset)
1022 {
1023         struct ntb_payload_header __iomem *hdr;
1024
1025         memcpy_toio(offset, entry->buf, entry->len);
1026
1027         hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
1028         iowrite32(entry->len, &hdr->len);
1029         iowrite32((u32) qp->tx_pkts, &hdr->ver);
1030
1031         /* Ensure that the data is fully copied out before setting the flag */
1032         wmb();
1033         iowrite32(entry->flags | DESC_DONE_FLAG, &hdr->flags);
1034
1035         ntb_ring_sdb(qp->ndev, qp->qp_num);
1036
1037         /* The entry length can only be zero if the packet is intended to be a
1038          * "link down" or similar.  Since no payload is being sent in these
1039          * cases, there is nothing to add to the completion queue.
1040          */
1041         if (entry->len > 0) {
1042                 qp->tx_bytes += entry->len;
1043
1044                 if (qp->tx_handler)
1045                         qp->tx_handler(qp, qp->cb_data, entry->cb_data,
1046                                        entry->len);
1047         }
1048
1049         ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q);
1050 }
1051
1052 static int ntb_process_tx(struct ntb_transport_qp *qp,
1053                           struct ntb_queue_entry *entry)
1054 {
1055         void __iomem *offset;
1056
1057         offset = qp->tx_mw + qp->tx_max_frame * qp->tx_index;
1058
1059         dev_dbg(&ntb_query_pdev(qp->ndev)->dev, "%lld - offset %p, tx %u, entry len %d flags %x buff %p\n",
1060                 qp->tx_pkts, offset, qp->tx_index, entry->len, entry->flags,
1061                 entry->buf);
1062         if (qp->tx_index == qp->remote_rx_info->entry) {
1063                 qp->tx_ring_full++;
1064                 return -EAGAIN;
1065         }
1066
1067         if (entry->len > qp->tx_max_frame - sizeof(struct ntb_payload_header)) {
1068                 if (qp->tx_handler)
1069                         qp->tx_handler(qp->cb_data, qp, NULL, -EIO);
1070
1071                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1072                              &qp->tx_free_q);
1073                 return 0;
1074         }
1075
1076         ntb_tx_copy_task(qp, entry, offset);
1077
1078         qp->tx_index++;
1079         qp->tx_index %= qp->tx_max_entry;
1080
1081         qp->tx_pkts++;
1082
1083         return 0;
1084 }
1085
1086 static void ntb_send_link_down(struct ntb_transport_qp *qp)
1087 {
1088         struct pci_dev *pdev = ntb_query_pdev(qp->ndev);
1089         struct ntb_queue_entry *entry;
1090         int i, rc;
1091
1092         if (qp->qp_link == NTB_LINK_DOWN)
1093                 return;
1094
1095         qp->qp_link = NTB_LINK_DOWN;
1096         dev_info(&pdev->dev, "qp %d: Link Down\n", qp->qp_num);
1097
1098         for (i = 0; i < NTB_LINK_DOWN_TIMEOUT; i++) {
1099                 entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1100                 if (entry)
1101                         break;
1102                 msleep(100);
1103         }
1104
1105         if (!entry)
1106                 return;
1107
1108         entry->cb_data = NULL;
1109         entry->buf = NULL;
1110         entry->len = 0;
1111         entry->flags = LINK_DOWN_FLAG;
1112
1113         rc = ntb_process_tx(qp, entry);
1114         if (rc)
1115                 dev_err(&pdev->dev, "ntb: QP%d unable to send linkdown msg\n",
1116                         qp->qp_num);
1117 }
1118
1119 /**
1120  * ntb_transport_create_queue - Create a new NTB transport layer queue
1121  * @rx_handler: receive callback function
1122  * @tx_handler: transmit callback function
1123  * @event_handler: event callback function
1124  *
1125  * Create a new NTB transport layer queue and provide the queue with a callback
1126  * routine for both transmit and receive.  The receive callback routine will be
1127  * used to pass up data when the transport has received it on the queue.   The
1128  * transmit callback routine will be called when the transport has completed the
1129  * transmission of the data on the queue and the data is ready to be freed.
1130  *
1131  * RETURNS: pointer to newly created ntb_queue, NULL on error.
1132  */
1133 struct ntb_transport_qp *
1134 ntb_transport_create_queue(void *data, struct pci_dev *pdev,
1135                            const struct ntb_queue_handlers *handlers)
1136 {
1137         struct ntb_queue_entry *entry;
1138         struct ntb_transport_qp *qp;
1139         struct ntb_transport *nt;
1140         unsigned int free_queue;
1141         int rc, i;
1142
1143         nt = ntb_find_transport(pdev);
1144         if (!nt)
1145                 goto err;
1146
1147         free_queue = ffs(nt->qp_bitmap);
1148         if (!free_queue)
1149                 goto err;
1150
1151         /* decrement free_queue to make it zero based */
1152         free_queue--;
1153
1154         clear_bit(free_queue, &nt->qp_bitmap);
1155
1156         qp = &nt->qps[free_queue];
1157         qp->cb_data = data;
1158         qp->rx_handler = handlers->rx_handler;
1159         qp->tx_handler = handlers->tx_handler;
1160         qp->event_handler = handlers->event_handler;
1161
1162         for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
1163                 entry = kzalloc(sizeof(struct ntb_queue_entry), GFP_ATOMIC);
1164                 if (!entry)
1165                         goto err1;
1166
1167                 ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry,
1168                              &qp->rx_free_q);
1169         }
1170
1171         for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
1172                 entry = kzalloc(sizeof(struct ntb_queue_entry), GFP_ATOMIC);
1173                 if (!entry)
1174                         goto err2;
1175
1176                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1177                              &qp->tx_free_q);
1178         }
1179
1180         tasklet_init(&qp->rx_work, ntb_transport_rx, (unsigned long) qp);
1181
1182         rc = ntb_register_db_callback(qp->ndev, free_queue, qp,
1183                                       ntb_transport_rxc_db);
1184         if (rc)
1185                 goto err3;
1186
1187         dev_info(&pdev->dev, "NTB Transport QP %d created\n", qp->qp_num);
1188
1189         return qp;
1190
1191 err3:
1192         tasklet_disable(&qp->rx_work);
1193 err2:
1194         while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1195                 kfree(entry);
1196 err1:
1197         while ((entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q)))
1198                 kfree(entry);
1199         set_bit(free_queue, &nt->qp_bitmap);
1200 err:
1201         return NULL;
1202 }
1203 EXPORT_SYMBOL_GPL(ntb_transport_create_queue);
1204
1205 /**
1206  * ntb_transport_free_queue - Frees NTB transport queue
1207  * @qp: NTB queue to be freed
1208  *
1209  * Frees NTB transport queue
1210  */
1211 void ntb_transport_free_queue(struct ntb_transport_qp *qp)
1212 {
1213         struct pci_dev *pdev = ntb_query_pdev(qp->ndev);
1214         struct ntb_queue_entry *entry;
1215
1216         if (!qp)
1217                 return;
1218
1219         cancel_delayed_work_sync(&qp->link_work);
1220
1221         ntb_unregister_db_callback(qp->ndev, qp->qp_num);
1222         tasklet_disable(&qp->rx_work);
1223
1224         while ((entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q)))
1225                 kfree(entry);
1226
1227         while ((entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q))) {
1228                 dev_warn(&pdev->dev, "Freeing item from a non-empty queue\n");
1229                 kfree(entry);
1230         }
1231
1232         while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1233                 kfree(entry);
1234
1235         set_bit(qp->qp_num, &qp->transport->qp_bitmap);
1236
1237         dev_info(&pdev->dev, "NTB Transport QP %d freed\n", qp->qp_num);
1238 }
1239 EXPORT_SYMBOL_GPL(ntb_transport_free_queue);
1240
1241 /**
1242  * ntb_transport_rx_remove - Dequeues enqueued rx packet
1243  * @qp: NTB queue to be freed
1244  * @len: pointer to variable to write enqueued buffers length
1245  *
1246  * Dequeues unused buffers from receive queue.  Should only be used during
1247  * shutdown of qp.
1248  *
1249  * RETURNS: NULL error value on error, or void* for success.
1250  */
1251 void *ntb_transport_rx_remove(struct ntb_transport_qp *qp, unsigned int *len)
1252 {
1253         struct ntb_queue_entry *entry;
1254         void *buf;
1255
1256         if (!qp || qp->client_ready == NTB_LINK_UP)
1257                 return NULL;
1258
1259         entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q);
1260         if (!entry)
1261                 return NULL;
1262
1263         buf = entry->cb_data;
1264         *len = entry->len;
1265
1266         ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry, &qp->rx_free_q);
1267
1268         return buf;
1269 }
1270 EXPORT_SYMBOL_GPL(ntb_transport_rx_remove);
1271
1272 /**
1273  * ntb_transport_rx_enqueue - Enqueue a new NTB queue entry
1274  * @qp: NTB transport layer queue the entry is to be enqueued on
1275  * @cb: per buffer pointer for callback function to use
1276  * @data: pointer to data buffer that incoming packets will be copied into
1277  * @len: length of the data buffer
1278  *
1279  * Enqueue a new receive buffer onto the transport queue into which a NTB
1280  * payload can be received into.
1281  *
1282  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
1283  */
1284 int ntb_transport_rx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
1285                              unsigned int len)
1286 {
1287         struct ntb_queue_entry *entry;
1288
1289         if (!qp)
1290                 return -EINVAL;
1291
1292         entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q);
1293         if (!entry)
1294                 return -ENOMEM;
1295
1296         entry->cb_data = cb;
1297         entry->buf = data;
1298         entry->len = len;
1299
1300         ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry, &qp->rx_pend_q);
1301
1302         return 0;
1303 }
1304 EXPORT_SYMBOL_GPL(ntb_transport_rx_enqueue);
1305
1306 /**
1307  * ntb_transport_tx_enqueue - Enqueue a new NTB queue entry
1308  * @qp: NTB transport layer queue the entry is to be enqueued on
1309  * @cb: per buffer pointer for callback function to use
1310  * @data: pointer to data buffer that will be sent
1311  * @len: length of the data buffer
1312  *
1313  * Enqueue a new transmit buffer onto the transport queue from which a NTB
1314  * payload will be transmitted.  This assumes that a lock is behing held to
1315  * serialize access to the qp.
1316  *
1317  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
1318  */
1319 int ntb_transport_tx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
1320                              unsigned int len)
1321 {
1322         struct ntb_queue_entry *entry;
1323         int rc;
1324
1325         if (!qp || qp->qp_link != NTB_LINK_UP || !len)
1326                 return -EINVAL;
1327
1328         entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1329         if (!entry)
1330                 return -ENOMEM;
1331
1332         entry->cb_data = cb;
1333         entry->buf = data;
1334         entry->len = len;
1335         entry->flags = 0;
1336
1337         rc = ntb_process_tx(qp, entry);
1338         if (rc)
1339                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1340                              &qp->tx_free_q);
1341
1342         return rc;
1343 }
1344 EXPORT_SYMBOL_GPL(ntb_transport_tx_enqueue);
1345
1346 /**
1347  * ntb_transport_link_up - Notify NTB transport of client readiness to use queue
1348  * @qp: NTB transport layer queue to be enabled
1349  *
1350  * Notify NTB transport layer of client readiness to use queue
1351  */
1352 void ntb_transport_link_up(struct ntb_transport_qp *qp)
1353 {
1354         if (!qp)
1355                 return;
1356
1357         qp->client_ready = NTB_LINK_UP;
1358
1359         if (qp->transport->transport_link == NTB_LINK_UP)
1360                 schedule_delayed_work(&qp->link_work, 0);
1361 }
1362 EXPORT_SYMBOL_GPL(ntb_transport_link_up);
1363
1364 /**
1365  * ntb_transport_link_down - Notify NTB transport to no longer enqueue data
1366  * @qp: NTB transport layer queue to be disabled
1367  *
1368  * Notify NTB transport layer of client's desire to no longer receive data on
1369  * transport queue specified.  It is the client's responsibility to ensure all
1370  * entries on queue are purged or otherwise handled appropraitely.
1371  */
1372 void ntb_transport_link_down(struct ntb_transport_qp *qp)
1373 {
1374         struct pci_dev *pdev = ntb_query_pdev(qp->ndev);
1375         int rc, val;
1376
1377         if (!qp)
1378                 return;
1379
1380         qp->client_ready = NTB_LINK_DOWN;
1381
1382         rc = ntb_read_local_spad(qp->ndev, QP_LINKS, &val);
1383         if (rc) {
1384                 dev_err(&pdev->dev, "Error reading spad %d\n", QP_LINKS);
1385                 return;
1386         }
1387
1388         rc = ntb_write_remote_spad(qp->ndev, QP_LINKS,
1389                                    val & ~(1 << qp->qp_num));
1390         if (rc)
1391                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
1392                         val & ~(1 << qp->qp_num), QP_LINKS);
1393
1394         if (qp->qp_link == NTB_LINK_UP)
1395                 ntb_send_link_down(qp);
1396         else
1397                 cancel_delayed_work_sync(&qp->link_work);
1398 }
1399 EXPORT_SYMBOL_GPL(ntb_transport_link_down);
1400
1401 /**
1402  * ntb_transport_link_query - Query transport link state
1403  * @qp: NTB transport layer queue to be queried
1404  *
1405  * Query connectivity to the remote system of the NTB transport queue
1406  *
1407  * RETURNS: true for link up or false for link down
1408  */
1409 bool ntb_transport_link_query(struct ntb_transport_qp *qp)
1410 {
1411         return qp->qp_link == NTB_LINK_UP;
1412 }
1413 EXPORT_SYMBOL_GPL(ntb_transport_link_query);
1414
1415 /**
1416  * ntb_transport_qp_num - Query the qp number
1417  * @qp: NTB transport layer queue to be queried
1418  *
1419  * Query qp number of the NTB transport queue
1420  *
1421  * RETURNS: a zero based number specifying the qp number
1422  */
1423 unsigned char ntb_transport_qp_num(struct ntb_transport_qp *qp)
1424 {
1425         return qp->qp_num;
1426 }
1427 EXPORT_SYMBOL_GPL(ntb_transport_qp_num);
1428
1429 /**
1430  * ntb_transport_max_size - Query the max payload size of a qp
1431  * @qp: NTB transport layer queue to be queried
1432  *
1433  * Query the maximum payload size permissible on the given qp
1434  *
1435  * RETURNS: the max payload size of a qp
1436  */
1437 unsigned int ntb_transport_max_size(struct ntb_transport_qp *qp)
1438 {
1439         return qp->tx_max_frame - sizeof(struct ntb_payload_header);
1440 }
1441 EXPORT_SYMBOL_GPL(ntb_transport_max_size);