drivers/ntb/ntb_transport.c

   1 /*
   2  * This file is provided under a dual BSD/GPLv2 license.  When using or
   3  *   redistributing this file, you may do so under either license.
   4  *
   5  *   GPL LICENSE SUMMARY
   6  *
   7  *   Copyright(c) 2012 Intel Corporation. All rights reserved.
   8  *
   9  *   This program is free software; you can redistribute it and/or modify
  10  *   it under the terms of version 2 of the GNU General Public License as
  11  *   published by the Free Software Foundation.
  12  *
  13  *   BSD LICENSE
  14  *
  15  *   Copyright(c) 2012 Intel Corporation. All rights reserved.
  16  *
  17  *   Redistribution and use in source and binary forms, with or without
  18  *   modification, are permitted provided that the following conditions
  19  *   are met:
  20  *
  21  *     * Redistributions of source code must retain the above copyright
  22  *       notice, this list of conditions and the following disclaimer.
  23  *     * Redistributions in binary form must reproduce the above copy
  24  *       notice, this list of conditions and the following disclaimer in
  25  *       the documentation and/or other materials provided with the
  26  *       distribution.
  27  *     * Neither the name of Intel Corporation nor the names of its
  28  *       contributors may be used to endorse or promote products derived
  29  *       from this software without specific prior written permission.
  30  *
  31  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  32  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  33  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  34  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  35  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  36  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  37  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  38  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  39  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  40  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  41  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  42  *
  43  * Intel PCIe NTB Linux driver
  44  *
  45  * Contact Information:
  46  * Jon Mason <jon.mason@intel.com>
  47  */
  48 #include <linux/debugfs.h>
  49 #include <linux/delay.h>
  50 #include <linux/dma-mapping.h>
  51 #include <linux/errno.h>
  52 #include <linux/export.h>
  53 #include <linux/interrupt.h>
  54 #include <linux/module.h>
  55 #include <linux/pci.h>
  56 #include <linux/slab.h>
  57 #include <linux/types.h>
  58 #include <linux/ntb.h>
  59 #include "ntb_hw.h"
  60
  61 #define NTB_TRANSPORT_VERSION   3
  62
  63 static unsigned int transport_mtu = 0x401E;
  64 module_param(transport_mtu, uint, 0644);
  65 MODULE_PARM_DESC(transport_mtu, "Maximum size of NTB transport packets");
  66
  67 static unsigned char max_num_clients = 2;
  68 module_param(max_num_clients, byte, 0644);
  69 MODULE_PARM_DESC(max_num_clients, "Maximum number of NTB transport clients");
  70
  71 struct ntb_queue_entry {
  72         /* ntb_queue list reference */
  73         struct list_head entry;
  74         /* pointers to data to be transfered */
  75         void *cb_data;
  76         void *buf;
  77         unsigned int len;
  78         unsigned int flags;
  79 };
  80
  81 struct ntb_rx_info {
  82         unsigned int entry;
  83 };
  84
  85 struct ntb_transport_qp {
  86         struct ntb_transport *transport;
  87         struct ntb_device *ndev;
  88         void *cb_data;
  89
  90         bool client_ready;
  91         bool qp_link;
  92         u8 qp_num;      /* Only 64 QP's are allowed.  0-63 */
  93
  94         struct ntb_rx_info __iomem *rx_info;
  95         struct ntb_rx_info *remote_rx_info;
  96
  97         void (*tx_handler) (struct ntb_transport_qp *qp, void *qp_data,
  98                             void *data, int len);
  99         struct list_head tx_free_q;
 100         spinlock_t ntb_tx_free_q_lock;
 101         void __iomem *tx_mw;
 102         unsigned int tx_index;
 103         unsigned int tx_max_entry;
 104         unsigned int tx_max_frame;
 105
 106         void (*rx_handler) (struct ntb_transport_qp *qp, void *qp_data,
 107                             void *data, int len);
 108         struct tasklet_struct rx_work;
 109         struct list_head rx_pend_q;
 110         struct list_head rx_free_q;
 111         spinlock_t ntb_rx_pend_q_lock;
 112         spinlock_t ntb_rx_free_q_lock;
 113         void *rx_buff;
 114         unsigned int rx_index;
 115         unsigned int rx_max_entry;
 116         unsigned int rx_max_frame;
 117
 118         void (*event_handler) (void *data, int status);
 119         struct delayed_work link_work;
 120         struct work_struct link_cleanup;
 121
 122         struct dentry *debugfs_dir;
 123         struct dentry *debugfs_stats;
 124
 125         /* Stats */
 126         u64 rx_bytes;
 127         u64 rx_pkts;
 128         u64 rx_ring_empty;
 129         u64 rx_err_no_buf;
 130         u64 rx_err_oflow;
 131         u64 rx_err_ver;
 132         u64 tx_bytes;
 133         u64 tx_pkts;
 134         u64 tx_ring_full;
 135 };
 136
 137 struct ntb_transport_mw {
 138         size_t size;
 139         void *virt_addr;
 140         dma_addr_t dma_addr;
 141 };
 142
 143 struct ntb_transport_client_dev {
 144         struct list_head entry;
 145         struct device dev;
 146 };
 147
 148 struct ntb_transport {
 149         struct list_head entry;
 150         struct list_head client_devs;
 151
 152         struct ntb_device *ndev;
 153         struct ntb_transport_mw mw[NTB_NUM_MW];
 154         struct ntb_transport_qp *qps;
 155         unsigned int max_qps;
 156         unsigned long qp_bitmap;
 157         bool transport_link;
 158         struct delayed_work link_work;
 159         struct work_struct link_cleanup;
 160         struct dentry *debugfs_dir;
 161 };
 162
 163 enum {
 164         DESC_DONE_FLAG = 1 << 0,
 165         LINK_DOWN_FLAG = 1 << 1,
 166 };
 167
 168 struct ntb_payload_header {
 169         unsigned int ver;
 170         unsigned int len;
 171         unsigned int flags;
 172 };
 173
 174 enum {
 175         VERSION = 0,
 176         QP_LINKS,
 177         NUM_QPS,
 178         NUM_MWS,
 179         MW0_SZ_HIGH,
 180         MW0_SZ_LOW,
 181         MW1_SZ_HIGH,
 182         MW1_SZ_LOW,
 183         MAX_SPAD,
 184 };
 185
 186 #define QP_TO_MW(qp)            ((qp) % NTB_NUM_MW)
 187 #define NTB_QP_DEF_NUM_ENTRIES  100
 188 #define NTB_LINK_DOWN_TIMEOUT   10
 189
 190 static int ntb_match_bus(struct device *dev, struct device_driver *drv)
 191 {
 192         return !strncmp(dev_name(dev), drv->name, strlen(drv->name));
 193 }
 194
 195 static int ntb_client_probe(struct device *dev)
 196 {
 197         const struct ntb_client *drv = container_of(dev->driver,
 198                                                     struct ntb_client, driver);
 199         struct pci_dev *pdev = container_of(dev->parent, struct pci_dev, dev);
 200         int rc = -EINVAL;
 201
 202         get_device(dev);
 203         if (drv && drv->probe)
 204                 rc = drv->probe(pdev);
 205         if (rc)
 206                 put_device(dev);
 207
 208         return rc;
 209 }
 210
 211 static int ntb_client_remove(struct device *dev)
 212 {
 213         const struct ntb_client *drv = container_of(dev->driver,
 214                                                     struct ntb_client, driver);
 215         struct pci_dev *pdev = container_of(dev->parent, struct pci_dev, dev);
 216
 217         if (drv && drv->remove)
 218                 drv->remove(pdev);
 219
 220         put_device(dev);
 221
 222         return 0;
 223 }
 224
 225 static struct bus_type ntb_bus_type = {
 226         .name = "ntb_bus",
 227         .match = ntb_match_bus,
 228         .probe = ntb_client_probe,
 229         .remove = ntb_client_remove,
 230 };
 231
 232 static LIST_HEAD(ntb_transport_list);
 233
 234 static int ntb_bus_init(struct ntb_transport *nt)
 235 {
 236         if (list_empty(&ntb_transport_list)) {
 237                 int rc = bus_register(&ntb_bus_type);
 238                 if (rc)
 239                         return rc;
 240         }
 241
 242         list_add(&nt->entry, &ntb_transport_list);
 243
 244         return 0;
 245 }
 246
 247 static void ntb_bus_remove(struct ntb_transport *nt)
 248 {
 249         struct ntb_transport_client_dev *client_dev, *cd;
 250
 251         list_for_each_entry_safe(client_dev, cd, &nt->client_devs, entry) {
 252                 dev_err(client_dev->dev.parent, "%s still attached to bus, removing\n",
 253                         dev_name(&client_dev->dev));
 254                 list_del(&client_dev->entry);
 255                 device_unregister(&client_dev->dev);
 256         }
 257
 258         list_del(&nt->entry);
 259
 260         if (list_empty(&ntb_transport_list))
 261                 bus_unregister(&ntb_bus_type);
 262 }
 263
 264 static void ntb_client_release(struct device *dev)
 265 {
 266         struct ntb_transport_client_dev *client_dev;
 267         client_dev = container_of(dev, struct ntb_transport_client_dev, dev);
 268
 269         kfree(client_dev);
 270 }
 271
 272 /**
 273  * ntb_unregister_client_dev - Unregister NTB client device
 274  * @device_name: Name of NTB client device
 275  *
 276  * Unregister an NTB client device with the NTB transport layer
 277  */
 278 void ntb_unregister_client_dev(char *device_name)
 279 {
 280         struct ntb_transport_client_dev *client, *cd;
 281         struct ntb_transport *nt;
 282
 283         list_for_each_entry(nt, &ntb_transport_list, entry)
 284                 list_for_each_entry_safe(client, cd, &nt->client_devs, entry)
 285                         if (!strncmp(dev_name(&client->dev), device_name,
 286                                      strlen(device_name))) {
 287                                 list_del(&client->entry);
 288                                 device_unregister(&client->dev);
 289                         }
 290 }
 291 EXPORT_SYMBOL_GPL(ntb_unregister_client_dev);
 292
 293 /**
 294  * ntb_register_client_dev - Register NTB client device
 295  * @device_name: Name of NTB client device
 296  *
 297  * Register an NTB client device with the NTB transport layer
 298  */
 299 int ntb_register_client_dev(char *device_name)
 300 {
 301         struct ntb_transport_client_dev *client_dev;
 302         struct ntb_transport *nt;
 303         int rc;
 304
 305         if (list_empty(&ntb_transport_list))
 306                 return -ENODEV;
 307
 308         list_for_each_entry(nt, &ntb_transport_list, entry) {
 309                 struct device *dev;
 310
 311                 client_dev = kzalloc(sizeof(struct ntb_transport_client_dev),
 312                                      GFP_KERNEL);
 313                 if (!client_dev) {
 314                         rc = -ENOMEM;
 315                         goto err;
 316                 }
 317
 318                 dev = &client_dev->dev;
 319
 320                 /* setup and register client devices */
 321                 dev_set_name(dev, "%s", device_name);
 322                 dev->bus = &ntb_bus_type;
 323                 dev->release = ntb_client_release;
 324                 dev->parent = &ntb_query_pdev(nt->ndev)->dev;
 325
 326                 rc = device_register(dev);
 327                 if (rc) {
 328                         kfree(client_dev);
 329                         goto err;
 330                 }
 331
 332                 list_add_tail(&client_dev->entry, &nt->client_devs);
 333         }
 334
 335         return 0;
 336
 337 err:
 338         ntb_unregister_client_dev(device_name);
 339
 340         return rc;
 341 }
 342 EXPORT_SYMBOL_GPL(ntb_register_client_dev);
 343
 344 /**
 345  * ntb_register_client - Register NTB client driver
 346  * @drv: NTB client driver to be registered
 347  *
 348  * Register an NTB client driver with the NTB transport layer
 349  *
 350  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 351  */
 352 int ntb_register_client(struct ntb_client *drv)
 353 {
 354         drv->driver.bus = &ntb_bus_type;
 355
 356         if (list_empty(&ntb_transport_list))
 357                 return -ENODEV;
 358
 359         return driver_register(&drv->driver);
 360 }
 361 EXPORT_SYMBOL_GPL(ntb_register_client);
 362
 363 /**
 364  * ntb_unregister_client - Unregister NTB client driver
 365  * @drv: NTB client driver to be unregistered
 366  *
 367  * Unregister an NTB client driver with the NTB transport layer
 368  *
 369  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 370  */
 371 void ntb_unregister_client(struct ntb_client *drv)
 372 {
 373         driver_unregister(&drv->driver);
 374 }
 375 EXPORT_SYMBOL_GPL(ntb_unregister_client);
 376
 377 static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count,
 378                             loff_t *offp)
 379 {
 380         struct ntb_transport_qp *qp;
 381         char *buf;
 382         ssize_t ret, out_offset, out_count;
 383
 384         out_count = 600;
 385
 386         buf = kmalloc(out_count, GFP_KERNEL);
 387         if (!buf)
 388                 return -ENOMEM;
 389
 390         qp = filp->private_data;
 391         out_offset = 0;
 392         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 393                                "NTB QP stats\n");
 394         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 395                                "rx_bytes - \t%llu\n", qp->rx_bytes);
 396         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 397                                "rx_pkts - \t%llu\n", qp->rx_pkts);
 398         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 399                                "rx_ring_empty - %llu\n", qp->rx_ring_empty);
 400         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 401                                "rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
 402         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 403                                "rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
 404         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 405                                "rx_err_ver - \t%llu\n", qp->rx_err_ver);
 406         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 407                                "rx_buff - \t%p\n", qp->rx_buff);
 408         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 409                                "rx_index - \t%u\n", qp->rx_index);
 410         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 411                                "rx_max_entry - \t%u\n", qp->rx_max_entry);
 412
 413         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 414                                "tx_bytes - \t%llu\n", qp->tx_bytes);
 415         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 416                                "tx_pkts - \t%llu\n", qp->tx_pkts);
 417         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 418                                "tx_ring_full - \t%llu\n", qp->tx_ring_full);
 419         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 420                                "tx_mw - \t%p\n", qp->tx_mw);
 421         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 422                                "tx_index - \t%u\n", qp->tx_index);
 423         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 424                                "tx_max_entry - \t%u\n", qp->tx_max_entry);
 425
 426         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 427                                "\nQP Link %s\n", (qp->qp_link == NTB_LINK_UP) ?
 428                                "Up" : "Down");
 429         if (out_offset > out_count)
 430                 out_offset = out_count;
 431
 432         ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
 433         kfree(buf);
 434         return ret;
 435 }
 436
 437 static const struct file_operations ntb_qp_debugfs_stats = {
 438         .owner = THIS_MODULE,
 439         .open = simple_open,
 440         .read = debugfs_read,
 441 };
 442
 443 static void ntb_list_add(spinlock_t *lock, struct list_head *entry,
 444                          struct list_head *list)
 445 {
 446         unsigned long flags;
 447
 448         spin_lock_irqsave(lock, flags);
 449         list_add_tail(entry, list);
 450         spin_unlock_irqrestore(lock, flags);
 451 }
 452
 453 static struct ntb_queue_entry *ntb_list_rm(spinlock_t *lock,
 454                                                 struct list_head *list)
 455 {
 456         struct ntb_queue_entry *entry;
 457         unsigned long flags;
 458
 459         spin_lock_irqsave(lock, flags);
 460         if (list_empty(list)) {
 461                 entry = NULL;
 462                 goto out;
 463         }
 464         entry = list_first_entry(list, struct ntb_queue_entry, entry);
 465         list_del(&entry->entry);
 466 out:
 467         spin_unlock_irqrestore(lock, flags);
 468
 469         return entry;
 470 }
 471
 472 static void ntb_transport_setup_qp_mw(struct ntb_transport *nt,
 473                                       unsigned int qp_num)
 474 {
 475         struct ntb_transport_qp *qp = &nt->qps[qp_num];
 476         unsigned int rx_size, num_qps_mw;
 477         u8 mw_num = QP_TO_MW(qp_num);
 478         unsigned int i;
 479
 480         WARN_ON(nt->mw[mw_num].virt_addr == NULL);
 481
 482         if (nt->max_qps % NTB_NUM_MW && mw_num < nt->max_qps % NTB_NUM_MW)
 483                 num_qps_mw = nt->max_qps / NTB_NUM_MW + 1;
 484         else
 485                 num_qps_mw = nt->max_qps / NTB_NUM_MW;
 486
 487         rx_size = (unsigned int) nt->mw[mw_num].size / num_qps_mw;
 488         qp->remote_rx_info = nt->mw[mw_num].virt_addr +
 489                              (qp_num / NTB_NUM_MW * rx_size);
 490         rx_size -= sizeof(struct ntb_rx_info);
 491
 492         qp->rx_buff = qp->remote_rx_info + 1;
 493         qp->rx_max_frame = min(transport_mtu, rx_size);
 494         qp->rx_max_entry = rx_size / qp->rx_max_frame;
 495         qp->rx_index = 0;
 496
 497         qp->remote_rx_info->entry = qp->rx_max_entry;
 498
 499         /* setup the hdr offsets with 0's */
 500         for (i = 0; i < qp->rx_max_entry; i++) {
 501                 void *offset = qp->rx_buff + qp->rx_max_frame * (i + 1) -
 502                                sizeof(struct ntb_payload_header);
 503                 memset(offset, 0, sizeof(struct ntb_payload_header));
 504         }
 505
 506         qp->rx_pkts = 0;
 507         qp->tx_pkts = 0;
 508         qp->tx_index = 0;
 509 }
 510
 511 static void ntb_free_mw(struct ntb_transport *nt, int num_mw)
 512 {
 513         struct ntb_transport_mw *mw = &nt->mw[num_mw];
 514         struct pci_dev *pdev = ntb_query_pdev(nt->ndev);
 515
 516         if (!mw->virt_addr)
 517                 return;
 518
 519         dma_free_coherent(&pdev->dev, mw->size, mw->virt_addr, mw->dma_addr);
 520         mw->virt_addr = NULL;
 521 }
 522
 523 static int ntb_set_mw(struct ntb_transport *nt, int num_mw, unsigned int size)
 524 {
 525         struct ntb_transport_mw *mw = &nt->mw[num_mw];
 526         struct pci_dev *pdev = ntb_query_pdev(nt->ndev);
 527
 528         /* No need to re-setup */
 529         if (mw->size == ALIGN(size, 4096))
 530                 return 0;
 531
 532         if (mw->size != 0)
 533                 ntb_free_mw(nt, num_mw);
 534
 535         /* Alloc memory for receiving data.  Must be 4k aligned */
 536         mw->size = ALIGN(size, 4096);
 537
 538         mw->virt_addr = dma_alloc_coherent(&pdev->dev, mw->size, &mw->dma_addr,
 539                                            GFP_KERNEL);
 540         if (!mw->virt_addr) {
 541                 mw->size = 0;
 542                 dev_err(&pdev->dev, "Unable to allocate MW buffer of size %d\n",
 543                        (int) mw->size);
 544                 return -ENOMEM;
 545         }
 546
 547         /* Notify HW the memory location of the receive buffer */
 548         ntb_set_mw_addr(nt->ndev, num_mw, mw->dma_addr);
 549
 550         return 0;
 551 }
 552
 553 static void ntb_qp_link_cleanup(struct work_struct *work)
 554 {
 555         struct ntb_transport_qp *qp = container_of(work,
 556                                                    struct ntb_transport_qp,
 557                                                    link_cleanup);
 558         struct ntb_transport *nt = qp->transport;
 559         struct pci_dev *pdev = ntb_query_pdev(nt->ndev);
 560
 561         if (qp->qp_link == NTB_LINK_DOWN) {
 562                 cancel_delayed_work_sync(&qp->link_work);
 563                 return;
 564         }
 565
 566         if (qp->event_handler)
 567                 qp->event_handler(qp->cb_data, NTB_LINK_DOWN);
 568
 569         dev_info(&pdev->dev, "qp %d: Link Down\n", qp->qp_num);
 570         qp->qp_link = NTB_LINK_DOWN;
 571
 572         if (nt->transport_link == NTB_LINK_UP)
 573                 schedule_delayed_work(&qp->link_work,
 574                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 575 }
 576
 577 static void ntb_qp_link_down(struct ntb_transport_qp *qp)
 578 {
 579         schedule_work(&qp->link_cleanup);
 580 }
 581
 582 static void ntb_transport_link_cleanup(struct work_struct *work)
 583 {
 584         struct ntb_transport *nt = container_of(work, struct ntb_transport,
 585                                                 link_cleanup);
 586         int i;
 587
 588         if (nt->transport_link == NTB_LINK_DOWN)
 589                 cancel_delayed_work_sync(&nt->link_work);
 590         else
 591                 nt->transport_link = NTB_LINK_DOWN;
 592
 593         /* Pass along the info to any clients */
 594         for (i = 0; i < nt->max_qps; i++)
 595                 if (!test_bit(i, &nt->qp_bitmap))
 596                         ntb_qp_link_down(&nt->qps[i]);
 597
 598         /* The scratchpad registers keep the values if the remote side
 599          * goes down, blast them now to give them a sane value the next
 600          * time they are accessed
 601          */
 602         for (i = 0; i < MAX_SPAD; i++)
 603                 ntb_write_local_spad(nt->ndev, i, 0);
 604 }
 605
 606 static void ntb_transport_event_callback(void *data, enum ntb_hw_event event)
 607 {
 608         struct ntb_transport *nt = data;
 609
 610         switch (event) {
 611         case NTB_EVENT_HW_LINK_UP:
 612                 schedule_delayed_work(&nt->link_work, 0);
 613                 break;
 614         case NTB_EVENT_HW_LINK_DOWN:
 615                 schedule_work(&nt->link_cleanup);
 616                 break;
 617         default:
 618                 BUG();
 619         }
 620 }
 621
 622 static void ntb_transport_link_work(struct work_struct *work)
 623 {
 624         struct ntb_transport *nt = container_of(work, struct ntb_transport,
 625                                                 link_work.work);
 626         struct ntb_device *ndev = nt->ndev;
 627         struct pci_dev *pdev = ntb_query_pdev(ndev);
 628         u32 val;
 629         int rc, i;
 630
 631         /* send the local info, in the opposite order of the way we read it */
 632         for (i = 0; i < NTB_NUM_MW; i++) {
 633                 rc = ntb_write_remote_spad(ndev, MW0_SZ_HIGH + (i * 2),
 634                                            ntb_get_mw_size(ndev, i) >> 32);
 635                 if (rc) {
 636                         dev_err(&pdev->dev, "Error writing %u to remote spad %d\n",
 637                                 (u32)(ntb_get_mw_size(ndev, i) >> 32),
 638                                 MW0_SZ_HIGH + (i * 2));
 639                         goto out;
 640                 }
 641
 642                 rc = ntb_write_remote_spad(ndev, MW0_SZ_LOW + (i * 2),
 643                                            (u32) ntb_get_mw_size(ndev, i));
 644                 if (rc) {
 645                         dev_err(&pdev->dev, "Error writing %u to remote spad %d\n",
 646                                 (u32) ntb_get_mw_size(ndev, i),
 647                                 MW0_SZ_LOW + (i * 2));
 648                         goto out;
 649                 }
 650         }
 651
 652         rc = ntb_write_remote_spad(ndev, NUM_MWS, NTB_NUM_MW);
 653         if (rc) {
 654                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
 655                         NTB_NUM_MW, NUM_MWS);
 656                 goto out;
 657         }
 658
 659         rc = ntb_write_remote_spad(ndev, NUM_QPS, nt->max_qps);
 660         if (rc) {
 661                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
 662                         nt->max_qps, NUM_QPS);
 663                 goto out;
 664         }
 665
 666         rc = ntb_write_remote_spad(ndev, VERSION, NTB_TRANSPORT_VERSION);
 667         if (rc) {
 668                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
 669                         NTB_TRANSPORT_VERSION, VERSION);
 670                 goto out;
 671         }
 672
 673         /* Query the remote side for its info */
 674         rc = ntb_read_remote_spad(ndev, VERSION, &val);
 675         if (rc) {
 676                 dev_err(&pdev->dev, "Error reading remote spad %d\n", VERSION);
 677                 goto out;
 678         }
 679
 680         if (val != NTB_TRANSPORT_VERSION)
 681                 goto out;
 682         dev_dbg(&pdev->dev, "Remote version = %d\n", val);
 683
 684         rc = ntb_read_remote_spad(ndev, NUM_QPS, &val);
 685         if (rc) {
 686                 dev_err(&pdev->dev, "Error reading remote spad %d\n", NUM_QPS);
 687                 goto out;
 688         }
 689
 690         if (val != nt->max_qps)
 691                 goto out;
 692         dev_dbg(&pdev->dev, "Remote max number of qps = %d\n", val);
 693
 694         rc = ntb_read_remote_spad(ndev, NUM_MWS, &val);
 695         if (rc) {
 696                 dev_err(&pdev->dev, "Error reading remote spad %d\n", NUM_MWS);
 697                 goto out;
 698         }
 699
 700         if (val != NTB_NUM_MW)
 701                 goto out;
 702         dev_dbg(&pdev->dev, "Remote number of mws = %d\n", val);
 703
 704         for (i = 0; i < NTB_NUM_MW; i++) {
 705                 u64 val64;
 706
 707                 rc = ntb_read_remote_spad(ndev, MW0_SZ_HIGH + (i * 2), &val);
 708                 if (rc) {
 709                         dev_err(&pdev->dev, "Error reading remote spad %d\n",
 710                                 MW0_SZ_HIGH + (i * 2));
 711                         goto out1;
 712                 }
 713
 714                 val64 = (u64) val << 32;
 715
 716                 rc = ntb_read_remote_spad(ndev, MW0_SZ_LOW + (i * 2), &val);
 717                 if (rc) {
 718                         dev_err(&pdev->dev, "Error reading remote spad %d\n",
 719                                 MW0_SZ_LOW + (i * 2));
 720                         goto out1;
 721                 }
 722
 723                 val64 |= val;
 724
 725                 dev_dbg(&pdev->dev, "Remote MW%d size = %llu\n", i, val64);
 726
 727                 rc = ntb_set_mw(nt, i, val64);
 728                 if (rc)
 729                         goto out1;
 730         }
 731
 732         nt->transport_link = NTB_LINK_UP;
 733
 734         for (i = 0; i < nt->max_qps; i++) {
 735                 struct ntb_transport_qp *qp = &nt->qps[i];
 736
 737                 ntb_transport_setup_qp_mw(nt, i);
 738
 739                 if (qp->client_ready == NTB_LINK_UP)
 740                         schedule_delayed_work(&qp->link_work, 0);
 741         }
 742
 743         return;
 744
 745 out1:
 746         for (i = 0; i < NTB_NUM_MW; i++)
 747                 ntb_free_mw(nt, i);
 748 out:
 749         if (ntb_hw_link_status(ndev))
 750                 schedule_delayed_work(&nt->link_work,
 751                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 752 }
 753
 754 static void ntb_qp_link_work(struct work_struct *work)
 755 {
 756         struct ntb_transport_qp *qp = container_of(work,
 757                                                    struct ntb_transport_qp,
 758                                                    link_work.work);
 759         struct pci_dev *pdev = ntb_query_pdev(qp->ndev);
 760         struct ntb_transport *nt = qp->transport;
 761         int rc, val;
 762
 763         WARN_ON(nt->transport_link != NTB_LINK_UP);
 764
 765         rc = ntb_read_local_spad(nt->ndev, QP_LINKS, &val);
 766         if (rc) {
 767                 dev_err(&pdev->dev, "Error reading spad %d\n", QP_LINKS);
 768                 return;
 769         }
 770
 771         rc = ntb_write_remote_spad(nt->ndev, QP_LINKS, val | 1 << qp->qp_num);
 772         if (rc)
 773                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
 774                         val | 1 << qp->qp_num, QP_LINKS);
 775
 776         /* query remote spad for qp ready bits */
 777         rc = ntb_read_remote_spad(nt->ndev, QP_LINKS, &val);
 778         if (rc)
 779                 dev_err(&pdev->dev, "Error reading remote spad %d\n", QP_LINKS);
 780
 781         dev_dbg(&pdev->dev, "Remote QP link status = %x\n", val);
 782
 783         /* See if the remote side is up */
 784         if (1 << qp->qp_num & val) {
 785                 qp->qp_link = NTB_LINK_UP;
 786
 787                 dev_info(&pdev->dev, "qp %d: Link Up\n", qp->qp_num);
 788                 if (qp->event_handler)
 789                         qp->event_handler(qp->cb_data, NTB_LINK_UP);
 790         } else if (nt->transport_link == NTB_LINK_UP)
 791                 schedule_delayed_work(&qp->link_work,
 792                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 793 }
 794
 795 static void ntb_transport_init_queue(struct ntb_transport *nt,
 796                                      unsigned int qp_num)
 797 {
 798         struct ntb_transport_qp *qp;
 799         unsigned int num_qps_mw, tx_size;
 800         u8 mw_num = QP_TO_MW(qp_num);
 801
 802         qp = &nt->qps[qp_num];
 803         qp->qp_num = qp_num;
 804         qp->transport = nt;
 805         qp->ndev = nt->ndev;
 806         qp->qp_link = NTB_LINK_DOWN;
 807         qp->client_ready = NTB_LINK_DOWN;
 808         qp->event_handler = NULL;
 809
 810         if (nt->max_qps % NTB_NUM_MW && mw_num < nt->max_qps % NTB_NUM_MW)
 811                 num_qps_mw = nt->max_qps / NTB_NUM_MW + 1;
 812         else
 813                 num_qps_mw = nt->max_qps / NTB_NUM_MW;
 814
 815         tx_size = (unsigned int) ntb_get_mw_size(qp->ndev, mw_num) / num_qps_mw;
 816         qp->rx_info = ntb_get_mw_vbase(nt->ndev, mw_num) +
 817                       (qp_num / NTB_NUM_MW * tx_size);
 818         tx_size -= sizeof(struct ntb_rx_info);
 819
 820         qp->tx_mw = qp->rx_info + 1;
 821         qp->tx_max_frame = min(transport_mtu, tx_size);
 822         qp->tx_max_entry = tx_size / qp->tx_max_frame;
 823
 824         if (nt->debugfs_dir) {
 825                 char debugfs_name[4];
 826
 827                 snprintf(debugfs_name, 4, "qp%d", qp_num);
 828                 qp->debugfs_dir = debugfs_create_dir(debugfs_name,
 829                                                      nt->debugfs_dir);
 830
 831                 qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR,
 832                                                         qp->debugfs_dir, qp,
 833                                                         &ntb_qp_debugfs_stats);
 834         }
 835
 836         INIT_DELAYED_WORK(&qp->link_work, ntb_qp_link_work);
 837         INIT_WORK(&qp->link_cleanup, ntb_qp_link_cleanup);
 838
 839         spin_lock_init(&qp->ntb_rx_pend_q_lock);
 840         spin_lock_init(&qp->ntb_rx_free_q_lock);
 841         spin_lock_init(&qp->ntb_tx_free_q_lock);
 842
 843         INIT_LIST_HEAD(&qp->rx_pend_q);
 844         INIT_LIST_HEAD(&qp->rx_free_q);
 845         INIT_LIST_HEAD(&qp->tx_free_q);
 846 }
 847
 848 int ntb_transport_init(struct pci_dev *pdev)
 849 {
 850         struct ntb_transport *nt;
 851         int rc, i;
 852
 853         nt = kzalloc(sizeof(struct ntb_transport), GFP_KERNEL);
 854         if (!nt)
 855                 return -ENOMEM;
 856
 857         if (debugfs_initialized())
 858                 nt->debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
 859         else
 860                 nt->debugfs_dir = NULL;
 861
 862         nt->ndev = ntb_register_transport(pdev, nt);
 863         if (!nt->ndev) {
 864                 rc = -EIO;
 865                 goto err;
 866         }
 867
 868         nt->max_qps = min(nt->ndev->max_cbs, max_num_clients);
 869
 870         nt->qps = kcalloc(nt->max_qps, sizeof(struct ntb_transport_qp),
 871                           GFP_KERNEL);
 872         if (!nt->qps) {
 873                 rc = -ENOMEM;
 874                 goto err1;
 875         }
 876
 877         nt->qp_bitmap = ((u64) 1 << nt->max_qps) - 1;
 878
 879         for (i = 0; i < nt->max_qps; i++)
 880                 ntb_transport_init_queue(nt, i);
 881
 882         INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work);
 883         INIT_WORK(&nt->link_cleanup, ntb_transport_link_cleanup);
 884
 885         rc = ntb_register_event_callback(nt->ndev,
 886                                          ntb_transport_event_callback);
 887         if (rc)
 888                 goto err2;
 889
 890         INIT_LIST_HEAD(&nt->client_devs);
 891         rc = ntb_bus_init(nt);
 892         if (rc)
 893                 goto err3;
 894
 895         if (ntb_hw_link_status(nt->ndev))
 896                 schedule_delayed_work(&nt->link_work, 0);
 897
 898         return 0;
 899
 900 err3:
 901         ntb_unregister_event_callback(nt->ndev);
 902 err2:
 903         kfree(nt->qps);
 904 err1:
 905         ntb_unregister_transport(nt->ndev);
 906 err:
 907         debugfs_remove_recursive(nt->debugfs_dir);
 908         kfree(nt);
 909         return rc;
 910 }
 911
 912 void ntb_transport_free(void *transport)
 913 {
 914         struct ntb_transport *nt = transport;
 915         struct pci_dev *pdev;
 916         int i;
 917
 918         nt->transport_link = NTB_LINK_DOWN;
 919
 920         /* verify that all the qp's are freed */
 921         for (i = 0; i < nt->max_qps; i++)
 922                 if (!test_bit(i, &nt->qp_bitmap))
 923                         ntb_transport_free_queue(&nt->qps[i]);
 924
 925         ntb_bus_remove(nt);
 926
 927         cancel_delayed_work_sync(&nt->link_work);
 928
 929         debugfs_remove_recursive(nt->debugfs_dir);
 930
 931         ntb_unregister_event_callback(nt->ndev);
 932
 933         pdev = ntb_query_pdev(nt->ndev);
 934
 935         for (i = 0; i < NTB_NUM_MW; i++)
 936                 ntb_free_mw(nt, i);
 937
 938         kfree(nt->qps);
 939         ntb_unregister_transport(nt->ndev);
 940         kfree(nt);
 941 }
 942
 943 static void ntb_rx_copy_task(struct ntb_transport_qp *qp,
 944                              struct ntb_queue_entry *entry, void *offset)
 945 {
 946         void *cb_data = entry->cb_data;
 947         unsigned int len = entry->len;
 948
 949         memcpy(entry->buf, offset, entry->len);
 950
 951         ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry, &qp->rx_free_q);
 952
 953         if (qp->rx_handler && qp->client_ready == NTB_LINK_UP)
 954                 qp->rx_handler(qp, qp->cb_data, cb_data, len);
 955 }
 956
 957 static int ntb_process_rxc(struct ntb_transport_qp *qp)
 958 {
 959         struct ntb_payload_header *hdr;
 960         struct ntb_queue_entry *entry;
 961         void *offset;
 962
 963         offset = qp->rx_buff + qp->rx_max_frame * qp->rx_index;
 964         hdr = offset + qp->rx_max_frame - sizeof(struct ntb_payload_header);
 965
 966         entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q);
 967         if (!entry) {
 968                 dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
 969                         "no buffer - HDR ver %u, len %d, flags %x\n",
 970                         hdr->ver, hdr->len, hdr->flags);
 971                 qp->rx_err_no_buf++;
 972                 return -ENOMEM;
 973         }
 974
 975         if (!(hdr->flags & DESC_DONE_FLAG)) {
 976                 ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
 977                              &qp->rx_pend_q);
 978                 qp->rx_ring_empty++;
 979                 return -EAGAIN;
 980         }
 981
 982         if (hdr->ver != (u32) qp->rx_pkts) {
 983                 dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
 984                         "qp %d: version mismatch, expected %llu - got %u\n",
 985                         qp->qp_num, qp->rx_pkts, hdr->ver);
 986                 ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
 987                              &qp->rx_pend_q);
 988                 qp->rx_err_ver++;
 989                 return -EIO;
 990         }
 991
 992         if (hdr->flags & LINK_DOWN_FLAG) {
 993                 ntb_qp_link_down(qp);
 994
 995                 ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
 996                              &qp->rx_pend_q);
 997                 goto out;
 998         }
 999
1000         dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
1001                 "rx offset %u, ver %u - %d payload received, buf size %d\n",
1002                 qp->rx_index, hdr->ver, hdr->len, entry->len);
1003
1004         if (hdr->len <= entry->len) {
1005                 entry->len = hdr->len;
1006                 ntb_rx_copy_task(qp, entry, offset);
1007         } else {
1008                 ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
1009                              &qp->rx_pend_q);
1010
1011                 qp->rx_err_oflow++;
1012                 dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
1013                         "RX overflow! Wanted %d got %d\n",
1014                         hdr->len, entry->len);
1015         }
1016
1017         qp->rx_bytes += hdr->len;
1018         qp->rx_pkts++;
1019
1020 out:
1021         /* Ensure that the data is fully copied out before clearing the flag */
1022         wmb();
1023         hdr->flags = 0;
1024         iowrite32(qp->rx_index, &qp->rx_info->entry);
1025
1026         qp->rx_index++;
1027         qp->rx_index %= qp->rx_max_entry;
1028
1029         return 0;
1030 }
1031
1032 static void ntb_transport_rx(unsigned long data)
1033 {
1034         struct ntb_transport_qp *qp = (struct ntb_transport_qp *)data;
1035         int rc;
1036
1037         do {
1038                 rc = ntb_process_rxc(qp);
1039         } while (!rc);
1040 }
1041
1042 static void ntb_transport_rxc_db(void *data, int db_num)
1043 {
1044         struct ntb_transport_qp *qp = data;
1045
1046         dev_dbg(&ntb_query_pdev(qp->ndev)->dev, "%s: doorbell %d received\n",
1047                 __func__, db_num);
1048
1049         tasklet_schedule(&qp->rx_work);
1050 }
1051
1052 static void ntb_tx_copy_task(struct ntb_transport_qp *qp,
1053                              struct ntb_queue_entry *entry,
1054                              void __iomem *offset)
1055 {
1056         struct ntb_payload_header __iomem *hdr;
1057
1058         memcpy_toio(offset, entry->buf, entry->len);
1059
1060         hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
1061         iowrite32(entry->len, &hdr->len);
1062         iowrite32((u32) qp->tx_pkts, &hdr->ver);
1063
1064         /* Ensure that the data is fully copied out before setting the flag */
1065         wmb();
1066         iowrite32(entry->flags | DESC_DONE_FLAG, &hdr->flags);
1067
1068         ntb_ring_sdb(qp->ndev, qp->qp_num);
1069
1070         /* The entry length can only be zero if the packet is intended to be a
1071          * "link down" or similar.  Since no payload is being sent in these
1072          * cases, there is nothing to add to the completion queue.
1073          */
1074         if (entry->len > 0) {
1075                 qp->tx_bytes += entry->len;
1076
1077                 if (qp->tx_handler)
1078                         qp->tx_handler(qp, qp->cb_data, entry->cb_data,
1079                                        entry->len);
1080         }
1081
1082         ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q);
1083 }
1084
1085 static int ntb_process_tx(struct ntb_transport_qp *qp,
1086                           struct ntb_queue_entry *entry)
1087 {
1088         void __iomem *offset;
1089
1090         offset = qp->tx_mw + qp->tx_max_frame * qp->tx_index;
1091
1092         dev_dbg(&ntb_query_pdev(qp->ndev)->dev, "%lld - offset %p, tx %u, entry len %d flags %x buff %p\n",
1093                 qp->tx_pkts, offset, qp->tx_index, entry->len, entry->flags,
1094                 entry->buf);
1095         if (qp->tx_index == qp->remote_rx_info->entry) {
1096                 qp->tx_ring_full++;
1097                 return -EAGAIN;
1098         }
1099
1100         if (entry->len > qp->tx_max_frame - sizeof(struct ntb_payload_header)) {
1101                 if (qp->tx_handler)
1102                         qp->tx_handler(qp->cb_data, qp, NULL, -EIO);
1103
1104                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1105                              &qp->tx_free_q);
1106                 return 0;
1107         }
1108
1109         ntb_tx_copy_task(qp, entry, offset);
1110
1111         qp->tx_index++;
1112         qp->tx_index %= qp->tx_max_entry;
1113
1114         qp->tx_pkts++;
1115
1116         return 0;
1117 }
1118
1119 static void ntb_send_link_down(struct ntb_transport_qp *qp)
1120 {
1121         struct pci_dev *pdev = ntb_query_pdev(qp->ndev);
1122         struct ntb_queue_entry *entry;
1123         int i, rc;
1124
1125         if (qp->qp_link == NTB_LINK_DOWN)
1126                 return;
1127
1128         qp->qp_link = NTB_LINK_DOWN;
1129         dev_info(&pdev->dev, "qp %d: Link Down\n", qp->qp_num);
1130
1131         for (i = 0; i < NTB_LINK_DOWN_TIMEOUT; i++) {
1132                 entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1133                 if (entry)
1134                         break;
1135                 msleep(100);
1136         }
1137
1138         if (!entry)
1139                 return;
1140
1141         entry->cb_data = NULL;
1142         entry->buf = NULL;
1143         entry->len = 0;
1144         entry->flags = LINK_DOWN_FLAG;
1145
1146         rc = ntb_process_tx(qp, entry);
1147         if (rc)
1148                 dev_err(&pdev->dev, "ntb: QP%d unable to send linkdown msg\n",
1149                         qp->qp_num);
1150 }
1151
1152 /**
1153  * ntb_transport_create_queue - Create a new NTB transport layer queue
1154  * @rx_handler: receive callback function
1155  * @tx_handler: transmit callback function
1156  * @event_handler: event callback function
1157  *
1158  * Create a new NTB transport layer queue and provide the queue with a callback
1159  * routine for both transmit and receive.  The receive callback routine will be
1160  * used to pass up data when the transport has received it on the queue.   The
1161  * transmit callback routine will be called when the transport has completed the
1162  * transmission of the data on the queue and the data is ready to be freed.
1163  *
1164  * RETURNS: pointer to newly created ntb_queue, NULL on error.
1165  */
1166 struct ntb_transport_qp *
1167 ntb_transport_create_queue(void *data, struct pci_dev *pdev,
1168                            const struct ntb_queue_handlers *handlers)
1169 {
1170         struct ntb_queue_entry *entry;
1171         struct ntb_transport_qp *qp;
1172         struct ntb_transport *nt;
1173         unsigned int free_queue;
1174         int rc, i;
1175
1176         nt = ntb_find_transport(pdev);
1177         if (!nt)
1178                 goto err;
1179
1180         free_queue = ffs(nt->qp_bitmap);
1181         if (!free_queue)
1182                 goto err;
1183
1184         /* decrement free_queue to make it zero based */
1185         free_queue--;
1186
1187         clear_bit(free_queue, &nt->qp_bitmap);
1188
1189         qp = &nt->qps[free_queue];
1190         qp->cb_data = data;
1191         qp->rx_handler = handlers->rx_handler;
1192         qp->tx_handler = handlers->tx_handler;
1193         qp->event_handler = handlers->event_handler;
1194
1195         for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
1196                 entry = kzalloc(sizeof(struct ntb_queue_entry), GFP_ATOMIC);
1197                 if (!entry)
1198                         goto err1;
1199
1200                 ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry,
1201                              &qp->rx_free_q);
1202         }
1203
1204         for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
1205                 entry = kzalloc(sizeof(struct ntb_queue_entry), GFP_ATOMIC);
1206                 if (!entry)
1207                         goto err2;
1208
1209                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1210                              &qp->tx_free_q);
1211         }
1212
1213         tasklet_init(&qp->rx_work, ntb_transport_rx, (unsigned long) qp);
1214
1215         rc = ntb_register_db_callback(qp->ndev, free_queue, qp,
1216                                       ntb_transport_rxc_db);
1217         if (rc)
1218                 goto err3;
1219
1220         dev_info(&pdev->dev, "NTB Transport QP %d created\n", qp->qp_num);
1221
1222         return qp;
1223
1224 err3:
1225         tasklet_disable(&qp->rx_work);
1226 err2:
1227         while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1228                 kfree(entry);
1229 err1:
1230         while ((entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q)))
1231                 kfree(entry);
1232         set_bit(free_queue, &nt->qp_bitmap);
1233 err:
1234         return NULL;
1235 }
1236 EXPORT_SYMBOL_GPL(ntb_transport_create_queue);
1237
1238 /**
1239  * ntb_transport_free_queue - Frees NTB transport queue
1240  * @qp: NTB queue to be freed
1241  *
1242  * Frees NTB transport queue
1243  */
1244 void ntb_transport_free_queue(struct ntb_transport_qp *qp)
1245 {
1246         struct pci_dev *pdev;
1247         struct ntb_queue_entry *entry;
1248
1249         if (!qp)
1250                 return;
1251
1252         pdev = ntb_query_pdev(qp->ndev);
1253
1254         cancel_delayed_work_sync(&qp->link_work);
1255
1256         ntb_unregister_db_callback(qp->ndev, qp->qp_num);
1257         tasklet_disable(&qp->rx_work);
1258
1259         while ((entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q)))
1260                 kfree(entry);
1261
1262         while ((entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q))) {
1263                 dev_warn(&pdev->dev, "Freeing item from a non-empty queue\n");
1264                 kfree(entry);
1265         }
1266
1267         while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1268                 kfree(entry);
1269
1270         set_bit(qp->qp_num, &qp->transport->qp_bitmap);
1271
1272         dev_info(&pdev->dev, "NTB Transport QP %d freed\n", qp->qp_num);
1273 }
1274 EXPORT_SYMBOL_GPL(ntb_transport_free_queue);
1275
1276 /**
1277  * ntb_transport_rx_remove - Dequeues enqueued rx packet
1278  * @qp: NTB queue to be freed
1279  * @len: pointer to variable to write enqueued buffers length
1280  *
1281  * Dequeues unused buffers from receive queue.  Should only be used during
1282  * shutdown of qp.
1283  *
1284  * RETURNS: NULL error value on error, or void* for success.
1285  */
1286 void *ntb_transport_rx_remove(struct ntb_transport_qp *qp, unsigned int *len)
1287 {
1288         struct ntb_queue_entry *entry;
1289         void *buf;
1290
1291         if (!qp || qp->client_ready == NTB_LINK_UP)
1292                 return NULL;
1293
1294         entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q);
1295         if (!entry)
1296                 return NULL;
1297
1298         buf = entry->cb_data;
1299         *len = entry->len;
1300
1301         ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry, &qp->rx_free_q);
1302
1303         return buf;
1304 }
1305 EXPORT_SYMBOL_GPL(ntb_transport_rx_remove);
1306
1307 /**
1308  * ntb_transport_rx_enqueue - Enqueue a new NTB queue entry
1309  * @qp: NTB transport layer queue the entry is to be enqueued on
1310  * @cb: per buffer pointer for callback function to use
1311  * @data: pointer to data buffer that incoming packets will be copied into
1312  * @len: length of the data buffer
1313  *
1314  * Enqueue a new receive buffer onto the transport queue into which a NTB
1315  * payload can be received into.
1316  *
1317  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
1318  */
1319 int ntb_transport_rx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
1320                              unsigned int len)
1321 {
1322         struct ntb_queue_entry *entry;
1323
1324         if (!qp)
1325                 return -EINVAL;
1326
1327         entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q);
1328         if (!entry)
1329                 return -ENOMEM;
1330
1331         entry->cb_data = cb;
1332         entry->buf = data;
1333         entry->len = len;
1334
1335         ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry, &qp->rx_pend_q);
1336
1337         return 0;
1338 }
1339 EXPORT_SYMBOL_GPL(ntb_transport_rx_enqueue);
1340
1341 /**
1342  * ntb_transport_tx_enqueue - Enqueue a new NTB queue entry
1343  * @qp: NTB transport layer queue the entry is to be enqueued on
1344  * @cb: per buffer pointer for callback function to use
1345  * @data: pointer to data buffer that will be sent
1346  * @len: length of the data buffer
1347  *
1348  * Enqueue a new transmit buffer onto the transport queue from which a NTB
1349  * payload will be transmitted.  This assumes that a lock is behing held to
1350  * serialize access to the qp.
1351  *
1352  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
1353  */
1354 int ntb_transport_tx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
1355                              unsigned int len)
1356 {
1357         struct ntb_queue_entry *entry;
1358         int rc;
1359
1360         if (!qp || qp->qp_link != NTB_LINK_UP || !len)
1361                 return -EINVAL;
1362
1363         entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1364         if (!entry)
1365                 return -ENOMEM;
1366
1367         entry->cb_data = cb;
1368         entry->buf = data;
1369         entry->len = len;
1370         entry->flags = 0;
1371
1372         rc = ntb_process_tx(qp, entry);
1373         if (rc)
1374                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1375                              &qp->tx_free_q);
1376
1377         return rc;
1378 }
1379 EXPORT_SYMBOL_GPL(ntb_transport_tx_enqueue);
1380
1381 /**
1382  * ntb_transport_link_up - Notify NTB transport of client readiness to use queue
1383  * @qp: NTB transport layer queue to be enabled
1384  *
1385  * Notify NTB transport layer of client readiness to use queue
1386  */
1387 void ntb_transport_link_up(struct ntb_transport_qp *qp)
1388 {
1389         if (!qp)
1390                 return;
1391
1392         qp->client_ready = NTB_LINK_UP;
1393
1394         if (qp->transport->transport_link == NTB_LINK_UP)
1395                 schedule_delayed_work(&qp->link_work, 0);
1396 }
1397 EXPORT_SYMBOL_GPL(ntb_transport_link_up);
1398
1399 /**
1400  * ntb_transport_link_down - Notify NTB transport to no longer enqueue data
1401  * @qp: NTB transport layer queue to be disabled
1402  *
1403  * Notify NTB transport layer of client's desire to no longer receive data on
1404  * transport queue specified.  It is the client's responsibility to ensure all
1405  * entries on queue are purged or otherwise handled appropraitely.
1406  */
1407 void ntb_transport_link_down(struct ntb_transport_qp *qp)
1408 {
1409         struct pci_dev *pdev;
1410         int rc, val;
1411
1412         if (!qp)
1413                 return;
1414
1415         pdev = ntb_query_pdev(qp->ndev);
1416         qp->client_ready = NTB_LINK_DOWN;
1417
1418         rc = ntb_read_local_spad(qp->ndev, QP_LINKS, &val);
1419         if (rc) {
1420                 dev_err(&pdev->dev, "Error reading spad %d\n", QP_LINKS);
1421                 return;
1422         }
1423
1424         rc = ntb_write_remote_spad(qp->ndev, QP_LINKS,
1425                                    val & ~(1 << qp->qp_num));
1426         if (rc)
1427                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
1428                         val & ~(1 << qp->qp_num), QP_LINKS);
1429
1430         if (qp->qp_link == NTB_LINK_UP)
1431                 ntb_send_link_down(qp);
1432         else
1433                 cancel_delayed_work_sync(&qp->link_work);
1434 }
1435 EXPORT_SYMBOL_GPL(ntb_transport_link_down);
1436
1437 /**
1438  * ntb_transport_link_query - Query transport link state
1439  * @qp: NTB transport layer queue to be queried
1440  *
1441  * Query connectivity to the remote system of the NTB transport queue
1442  *
1443  * RETURNS: true for link up or false for link down
1444  */
1445 bool ntb_transport_link_query(struct ntb_transport_qp *qp)
1446 {
1447         if (!qp)
1448                 return false;
1449
1450         return qp->qp_link == NTB_LINK_UP;
1451 }
1452 EXPORT_SYMBOL_GPL(ntb_transport_link_query);
1453
1454 /**
1455  * ntb_transport_qp_num - Query the qp number
1456  * @qp: NTB transport layer queue to be queried
1457  *
1458  * Query qp number of the NTB transport queue
1459  *
1460  * RETURNS: a zero based number specifying the qp number
1461  */
1462 unsigned char ntb_transport_qp_num(struct ntb_transport_qp *qp)
1463 {
1464         if (!qp)
1465                 return 0;
1466
1467         return qp->qp_num;
1468 }
1469 EXPORT_SYMBOL_GPL(ntb_transport_qp_num);
1470
1471 /**
1472  * ntb_transport_max_size - Query the max payload size of a qp
1473  * @qp: NTB transport layer queue to be queried
1474  *
1475  * Query the maximum payload size permissible on the given qp
1476  *
1477  * RETURNS: the max payload size of a qp
1478  */
1479 unsigned int ntb_transport_max_size(struct ntb_transport_qp *qp)
1480 {
1481         if (!qp)
1482                 return 0;
1483
1484         return qp->tx_max_frame - sizeof(struct ntb_payload_header);
1485 }
1486 EXPORT_SYMBOL_GPL(ntb_transport_max_size);