drivers/ntb/ntb_transport.c

   1 /*
   2  * This file is provided under a dual BSD/GPLv2 license.  When using or
   3  *   redistributing this file, you may do so under either license.
   4  *
   5  *   GPL LICENSE SUMMARY
   6  *
   7  *   Copyright(c) 2012 Intel Corporation. All rights reserved.
   8  *
   9  *   This program is free software; you can redistribute it and/or modify
  10  *   it under the terms of version 2 of the GNU General Public License as
  11  *   published by the Free Software Foundation.
  12  *
  13  *   BSD LICENSE
  14  *
  15  *   Copyright(c) 2012 Intel Corporation. All rights reserved.
  16  *
  17  *   Redistribution and use in source and binary forms, with or without
  18  *   modification, are permitted provided that the following conditions
  19  *   are met:
  20  *
  21  *     * Redistributions of source code must retain the above copyright
  22  *       notice, this list of conditions and the following disclaimer.
  23  *     * Redistributions in binary form must reproduce the above copy
  24  *       notice, this list of conditions and the following disclaimer in
  25  *       the documentation and/or other materials provided with the
  26  *       distribution.
  27  *     * Neither the name of Intel Corporation nor the names of its
  28  *       contributors may be used to endorse or promote products derived
  29  *       from this software without specific prior written permission.
  30  *
  31  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  32  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  33  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  34  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  35  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  36  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  37  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  38  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  39  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  40  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  41  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  42  *
  43  * Intel PCIe NTB Linux driver
  44  *
  45  * Contact Information:
  46  * Jon Mason <jon.mason@intel.com>
  47  */
  48 #include <linux/debugfs.h>
  49 #include <linux/delay.h>
  50 #include <linux/dma-mapping.h>
  51 #include <linux/errno.h>
  52 #include <linux/export.h>
  53 #include <linux/interrupt.h>
  54 #include <linux/module.h>
  55 #include <linux/pci.h>
  56 #include <linux/slab.h>
  57 #include <linux/types.h>
  58 #include <linux/ntb.h>
  59 #include "ntb_hw.h"
  60
  61 #define NTB_TRANSPORT_VERSION   1
  62
  63 static int transport_mtu = 0x401E;
  64 module_param(transport_mtu, uint, 0644);
  65 MODULE_PARM_DESC(transport_mtu, "Maximum size of NTB transport packets");
  66
  67 static unsigned char max_num_clients = 2;
  68 module_param(max_num_clients, byte, 0644);
  69 MODULE_PARM_DESC(max_num_clients, "Maximum number of NTB transport clients");
  70
  71 struct ntb_queue_entry {
  72         /* ntb_queue list reference */
  73         struct list_head entry;
  74         /* pointers to data to be transfered */
  75         void *cb_data;
  76         void *buf;
  77         unsigned int len;
  78         unsigned int flags;
  79 };
  80
  81 struct ntb_transport_qp {
  82         struct ntb_transport *transport;
  83         struct ntb_device *ndev;
  84         void *cb_data;
  85
  86         bool client_ready;
  87         bool qp_link;
  88         u8 qp_num;      /* Only 64 QP's are allowed.  0-63 */
  89
  90         void (*tx_handler) (struct ntb_transport_qp *qp, void *qp_data,
  91                             void *data, int len);
  92         struct list_head tx_free_q;
  93         spinlock_t ntb_tx_free_q_lock;
  94         void *tx_mw_begin;
  95         void *tx_mw_end;
  96         void *tx_offset;
  97
  98         void (*rx_handler) (struct ntb_transport_qp *qp, void *qp_data,
  99                             void *data, int len);
 100         struct tasklet_struct rx_work;
 101         struct list_head rx_pend_q;
 102         struct list_head rx_free_q;
 103         spinlock_t ntb_rx_pend_q_lock;
 104         spinlock_t ntb_rx_free_q_lock;
 105         void *rx_buff_begin;
 106         void *rx_buff_end;
 107         void *rx_offset;
 108
 109         void (*event_handler) (void *data, int status);
 110         struct delayed_work link_work;
 111
 112         struct dentry *debugfs_dir;
 113         struct dentry *debugfs_stats;
 114
 115         /* Stats */
 116         u64 rx_bytes;
 117         u64 rx_pkts;
 118         u64 rx_ring_empty;
 119         u64 rx_err_no_buf;
 120         u64 rx_err_oflow;
 121         u64 rx_err_ver;
 122         u64 tx_bytes;
 123         u64 tx_pkts;
 124         u64 tx_ring_full;
 125 };
 126
 127 struct ntb_transport_mw {
 128         size_t size;
 129         void *virt_addr;
 130         dma_addr_t dma_addr;
 131 };
 132
 133 struct ntb_transport_client_dev {
 134         struct list_head entry;
 135         struct device dev;
 136 };
 137
 138 struct ntb_transport {
 139         struct list_head entry;
 140         struct list_head client_devs;
 141
 142         struct ntb_device *ndev;
 143         struct ntb_transport_mw mw[NTB_NUM_MW];
 144         struct ntb_transport_qp *qps;
 145         unsigned int max_qps;
 146         unsigned long qp_bitmap;
 147         bool transport_link;
 148         struct delayed_work link_work;
 149         struct dentry *debugfs_dir;
 150 };
 151
 152 enum {
 153         DESC_DONE_FLAG = 1 << 0,
 154         LINK_DOWN_FLAG = 1 << 1,
 155 };
 156
 157 struct ntb_payload_header {
 158         u64 ver;
 159         unsigned int len;
 160         unsigned int flags;
 161 };
 162
 163 enum {
 164         VERSION = 0,
 165         MW0_SZ,
 166         MW1_SZ,
 167         NUM_QPS,
 168         QP_LINKS,
 169         MAX_SPAD,
 170 };
 171
 172 #define QP_TO_MW(qp)            ((qp) % NTB_NUM_MW)
 173 #define NTB_QP_DEF_NUM_ENTRIES  100
 174 #define NTB_LINK_DOWN_TIMEOUT   10
 175
 176 static int ntb_match_bus(struct device *dev, struct device_driver *drv)
 177 {
 178         return !strncmp(dev_name(dev), drv->name, strlen(drv->name));
 179 }
 180
 181 static int ntb_client_probe(struct device *dev)
 182 {
 183         const struct ntb_client *drv = container_of(dev->driver,
 184                                                     struct ntb_client, driver);
 185         struct pci_dev *pdev = container_of(dev->parent, struct pci_dev, dev);
 186         int rc = -EINVAL;
 187
 188         get_device(dev);
 189         if (drv && drv->probe)
 190                 rc = drv->probe(pdev);
 191         if (rc)
 192                 put_device(dev);
 193
 194         return rc;
 195 }
 196
 197 static int ntb_client_remove(struct device *dev)
 198 {
 199         const struct ntb_client *drv = container_of(dev->driver,
 200                                                     struct ntb_client, driver);
 201         struct pci_dev *pdev = container_of(dev->parent, struct pci_dev, dev);
 202
 203         if (drv && drv->remove)
 204                 drv->remove(pdev);
 205
 206         put_device(dev);
 207
 208         return 0;
 209 }
 210
 211 struct bus_type ntb_bus_type = {
 212         .name = "ntb_bus",
 213         .match = ntb_match_bus,
 214         .probe = ntb_client_probe,
 215         .remove = ntb_client_remove,
 216 };
 217
 218 static LIST_HEAD(ntb_transport_list);
 219
 220 static int ntb_bus_init(struct ntb_transport *nt)
 221 {
 222         if (list_empty(&ntb_transport_list)) {
 223                 int rc = bus_register(&ntb_bus_type);
 224                 if (rc)
 225                         return rc;
 226         }
 227
 228         list_add(&nt->entry, &ntb_transport_list);
 229
 230         return 0;
 231 }
 232
 233 static void ntb_bus_remove(struct ntb_transport *nt)
 234 {
 235         struct ntb_transport_client_dev *client_dev, *cd;
 236
 237         list_for_each_entry_safe(client_dev, cd, &nt->client_devs, entry) {
 238                 dev_err(client_dev->dev.parent, "%s still attached to bus, removing\n",
 239                         dev_name(&client_dev->dev));
 240                 list_del(&client_dev->entry);
 241                 device_unregister(&client_dev->dev);
 242         }
 243
 244         list_del(&nt->entry);
 245
 246         if (list_empty(&ntb_transport_list))
 247                 bus_unregister(&ntb_bus_type);
 248 }
 249
 250 static void ntb_client_release(struct device *dev)
 251 {
 252         struct ntb_transport_client_dev *client_dev;
 253         client_dev = container_of(dev, struct ntb_transport_client_dev, dev);
 254
 255         kfree(client_dev);
 256 }
 257
 258 /**
 259  * ntb_unregister_client_dev - Unregister NTB client device
 260  * @device_name: Name of NTB client device
 261  *
 262  * Unregister an NTB client device with the NTB transport layer
 263  */
 264 void ntb_unregister_client_dev(char *device_name)
 265 {
 266         struct ntb_transport_client_dev *client, *cd;
 267         struct ntb_transport *nt;
 268
 269         list_for_each_entry(nt, &ntb_transport_list, entry)
 270                 list_for_each_entry_safe(client, cd, &nt->client_devs, entry)
 271                         if (!strncmp(dev_name(&client->dev), device_name,
 272                                      strlen(device_name))) {
 273                                 list_del(&client->entry);
 274                                 device_unregister(&client->dev);
 275                         }
 276 }
 277 EXPORT_SYMBOL_GPL(ntb_unregister_client_dev);
 278
 279 /**
 280  * ntb_register_client_dev - Register NTB client device
 281  * @device_name: Name of NTB client device
 282  *
 283  * Register an NTB client device with the NTB transport layer
 284  */
 285 int ntb_register_client_dev(char *device_name)
 286 {
 287         struct ntb_transport_client_dev *client_dev;
 288         struct ntb_transport *nt;
 289         int rc;
 290
 291         list_for_each_entry(nt, &ntb_transport_list, entry) {
 292                 struct device *dev;
 293
 294                 client_dev = kzalloc(sizeof(struct ntb_transport_client_dev),
 295                                      GFP_KERNEL);
 296                 if (!client_dev) {
 297                         rc = -ENOMEM;
 298                         goto err;
 299                 }
 300
 301                 dev = &client_dev->dev;
 302
 303                 /* setup and register client devices */
 304                 dev_set_name(dev, "%s", device_name);
 305                 dev->bus = &ntb_bus_type;
 306                 dev->release = ntb_client_release;
 307                 dev->parent = &ntb_query_pdev(nt->ndev)->dev;
 308
 309                 rc = device_register(dev);
 310                 if (rc) {
 311                         kfree(client_dev);
 312                         goto err;
 313                 }
 314
 315                 list_add_tail(&client_dev->entry, &nt->client_devs);
 316         }
 317
 318         return 0;
 319
 320 err:
 321         ntb_unregister_client_dev(device_name);
 322
 323         return rc;
 324 }
 325 EXPORT_SYMBOL_GPL(ntb_register_client_dev);
 326
 327 /**
 328  * ntb_register_client - Register NTB client driver
 329  * @drv: NTB client driver to be registered
 330  *
 331  * Register an NTB client driver with the NTB transport layer
 332  *
 333  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 334  */
 335 int ntb_register_client(struct ntb_client *drv)
 336 {
 337         drv->driver.bus = &ntb_bus_type;
 338
 339         return driver_register(&drv->driver);
 340 }
 341 EXPORT_SYMBOL_GPL(ntb_register_client);
 342
 343 /**
 344  * ntb_unregister_client - Unregister NTB client driver
 345  * @drv: NTB client driver to be unregistered
 346  *
 347  * Unregister an NTB client driver with the NTB transport layer
 348  *
 349  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 350  */
 351 void ntb_unregister_client(struct ntb_client *drv)
 352 {
 353         driver_unregister(&drv->driver);
 354 }
 355 EXPORT_SYMBOL_GPL(ntb_unregister_client);
 356
 357 static int debugfs_open(struct inode *inode, struct file *filp)
 358 {
 359         filp->private_data = inode->i_private;
 360         return 0;
 361 }
 362
 363 static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count,
 364                             loff_t *offp)
 365 {
 366         struct ntb_transport_qp *qp;
 367         char buf[1024];
 368         ssize_t ret, out_offset, out_count;
 369
 370         out_count = 1024;
 371
 372         qp = filp->private_data;
 373         out_offset = 0;
 374         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 375                                "NTB QP stats\n");
 376         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 377                                "rx_bytes - \t%llu\n", qp->rx_bytes);
 378         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 379                                "rx_pkts - \t%llu\n", qp->rx_pkts);
 380         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 381                                "rx_ring_empty - %llu\n", qp->rx_ring_empty);
 382         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 383                                "rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
 384         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 385                                "rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
 386         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 387                                "rx_err_ver - \t%llu\n", qp->rx_err_ver);
 388         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 389                                "rx_buff_begin - %p\n", qp->rx_buff_begin);
 390         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 391                                "rx_offset - \t%p\n", qp->rx_offset);
 392         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 393                                "rx_buff_end - \t%p\n", qp->rx_buff_end);
 394
 395         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 396                                "tx_bytes - \t%llu\n", qp->tx_bytes);
 397         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 398                                "tx_pkts - \t%llu\n", qp->tx_pkts);
 399         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 400                                "tx_ring_full - \t%llu\n", qp->tx_ring_full);
 401         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 402                                "tx_mw_begin - \t%p\n", qp->tx_mw_begin);
 403         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 404                                "tx_offset - \t%p\n", qp->tx_offset);
 405         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 406                                "tx_mw_end - \t%p\n", qp->tx_mw_end);
 407
 408         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 409                                "QP Link %s\n", (qp->qp_link == NTB_LINK_UP) ?
 410                                "Up" : "Down");
 411
 412         ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
 413         return ret;
 414 }
 415
 416 static const struct file_operations ntb_qp_debugfs_stats = {
 417         .owner = THIS_MODULE,
 418         .open = debugfs_open,
 419         .read = debugfs_read,
 420 };
 421
 422 static void ntb_list_add(spinlock_t *lock, struct list_head *entry,
 423                          struct list_head *list)
 424 {
 425         unsigned long flags;
 426
 427         spin_lock_irqsave(lock, flags);
 428         list_add_tail(entry, list);
 429         spin_unlock_irqrestore(lock, flags);
 430 }
 431
 432 static struct ntb_queue_entry *ntb_list_rm(spinlock_t *lock,
 433                                                 struct list_head *list)
 434 {
 435         struct ntb_queue_entry *entry;
 436         unsigned long flags;
 437
 438         spin_lock_irqsave(lock, flags);
 439         if (list_empty(list)) {
 440                 entry = NULL;
 441                 goto out;
 442         }
 443         entry = list_first_entry(list, struct ntb_queue_entry, entry);
 444         list_del(&entry->entry);
 445 out:
 446         spin_unlock_irqrestore(lock, flags);
 447
 448         return entry;
 449 }
 450
 451 static void ntb_transport_setup_qp_mw(struct ntb_transport *nt,
 452                                       unsigned int qp_num)
 453 {
 454         struct ntb_transport_qp *qp = &nt->qps[qp_num];
 455         unsigned int size, num_qps_mw;
 456         u8 mw_num = QP_TO_MW(qp_num);
 457
 458         WARN_ON(nt->mw[mw_num].virt_addr == 0);
 459
 460         if (nt->max_qps % NTB_NUM_MW && !mw_num)
 461                 num_qps_mw = nt->max_qps / NTB_NUM_MW +
 462                              (nt->max_qps % NTB_NUM_MW - mw_num);
 463         else
 464                 num_qps_mw = nt->max_qps / NTB_NUM_MW;
 465
 466         size = nt->mw[mw_num].size / num_qps_mw;
 467
 468         qp->rx_buff_begin = nt->mw[mw_num].virt_addr +
 469                             (qp_num / NTB_NUM_MW * size);
 470         qp->rx_buff_end = qp->rx_buff_begin + size;
 471         qp->rx_offset = qp->rx_buff_begin;
 472
 473         qp->tx_mw_begin = ntb_get_mw_vbase(nt->ndev, mw_num) +
 474                           (qp_num / NTB_NUM_MW * size);
 475         qp->tx_mw_end = qp->tx_mw_begin + size;
 476         qp->tx_offset = qp->tx_mw_begin;
 477
 478         qp->rx_pkts = 0;
 479         qp->tx_pkts = 0;
 480 }
 481
 482 static int ntb_set_mw(struct ntb_transport *nt, int num_mw, unsigned int size)
 483 {
 484         struct ntb_transport_mw *mw = &nt->mw[num_mw];
 485         struct pci_dev *pdev = ntb_query_pdev(nt->ndev);
 486         void *offset;
 487
 488         /* Alloc memory for receiving data.  Must be 4k aligned */
 489         mw->size = ALIGN(size, 4096);
 490
 491         mw->virt_addr = dma_alloc_coherent(&pdev->dev, mw->size, &mw->dma_addr,
 492                                            GFP_KERNEL);
 493         if (!mw->virt_addr) {
 494                 dev_err(&pdev->dev, "Unable to allocate MW buffer of size %d\n",
 495                        (int) mw->size);
 496                 return -ENOMEM;
 497         }
 498
 499         /* setup the hdr offsets with 0's */
 500         for (offset = mw->virt_addr + transport_mtu -
 501                       sizeof(struct ntb_payload_header);
 502              offset < mw->virt_addr + size; offset += transport_mtu)
 503                 memset(offset, 0, sizeof(struct ntb_payload_header));
 504
 505         /* Notify HW the memory location of the receive buffer */
 506         ntb_set_mw_addr(nt->ndev, num_mw, mw->dma_addr);
 507
 508         return 0;
 509 }
 510
 511 static void ntb_qp_link_down(struct ntb_transport_qp *qp)
 512 {
 513         struct ntb_transport *nt = qp->transport;
 514         struct pci_dev *pdev = ntb_query_pdev(nt->ndev);
 515
 516         if (qp->qp_link == NTB_LINK_DOWN) {
 517                 cancel_delayed_work_sync(&qp->link_work);
 518                 return;
 519         }
 520
 521         if (qp->event_handler)
 522                 qp->event_handler(qp->cb_data, NTB_LINK_DOWN);
 523
 524         dev_info(&pdev->dev, "qp %d: Link Down\n", qp->qp_num);
 525         qp->qp_link = NTB_LINK_DOWN;
 526
 527         if (nt->transport_link == NTB_LINK_UP)
 528                 schedule_delayed_work(&qp->link_work,
 529                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 530 }
 531
 532 static void ntb_transport_conn_down(struct ntb_transport *nt)
 533 {
 534         int i;
 535
 536         if (nt->transport_link == NTB_LINK_DOWN)
 537                 cancel_delayed_work_sync(&nt->link_work);
 538         else
 539                 nt->transport_link = NTB_LINK_DOWN;
 540
 541         /* Pass along the info to any clients */
 542         for (i = 0; i < nt->max_qps; i++)
 543                 if (!test_bit(i, &nt->qp_bitmap))
 544                         ntb_qp_link_down(&nt->qps[i]);
 545
 546         /* The scratchpad registers keep the values if the remote side
 547          * goes down, blast them now to give them a sane value the next
 548          * time they are accessed
 549          */
 550         for (i = 0; i < MAX_SPAD; i++)
 551                 ntb_write_local_spad(nt->ndev, i, 0);
 552 }
 553
 554 static void ntb_transport_event_callback(void *data, enum ntb_hw_event event)
 555 {
 556         struct ntb_transport *nt = data;
 557
 558         switch (event) {
 559         case NTB_EVENT_HW_LINK_UP:
 560                 schedule_delayed_work(&nt->link_work, 0);
 561                 break;
 562         case NTB_EVENT_HW_LINK_DOWN:
 563                 ntb_transport_conn_down(nt);
 564                 break;
 565         default:
 566                 BUG();
 567         }
 568 }
 569
 570 static void ntb_transport_link_work(struct work_struct *work)
 571 {
 572         struct ntb_transport *nt = container_of(work, struct ntb_transport,
 573                                                 link_work.work);
 574         struct ntb_device *ndev = nt->ndev;
 575         struct pci_dev *pdev = ntb_query_pdev(ndev);
 576         u32 val;
 577         int rc, i;
 578
 579         /* send the local info */
 580         rc = ntb_write_remote_spad(ndev, VERSION, NTB_TRANSPORT_VERSION);
 581         if (rc) {
 582                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
 583                         0, VERSION);
 584                 goto out;
 585         }
 586
 587         rc = ntb_write_remote_spad(ndev, MW0_SZ, ntb_get_mw_size(ndev, 0));
 588         if (rc) {
 589                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
 590                         (u32) ntb_get_mw_size(ndev, 0), MW0_SZ);
 591                 goto out;
 592         }
 593
 594         rc = ntb_write_remote_spad(ndev, MW1_SZ, ntb_get_mw_size(ndev, 1));
 595         if (rc) {
 596                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
 597                         (u32) ntb_get_mw_size(ndev, 1), MW1_SZ);
 598                 goto out;
 599         }
 600
 601         rc = ntb_write_remote_spad(ndev, NUM_QPS, nt->max_qps);
 602         if (rc) {
 603                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
 604                         nt->max_qps, NUM_QPS);
 605                 goto out;
 606         }
 607
 608         rc = ntb_read_local_spad(nt->ndev, QP_LINKS, &val);
 609         if (rc) {
 610                 dev_err(&pdev->dev, "Error reading spad %d\n", QP_LINKS);
 611                 goto out;
 612         }
 613
 614         rc = ntb_write_remote_spad(ndev, QP_LINKS, val);
 615         if (rc) {
 616                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
 617                         val, QP_LINKS);
 618                 goto out;
 619         }
 620
 621         /* Query the remote side for its info */
 622         rc = ntb_read_remote_spad(ndev, VERSION, &val);
 623         if (rc) {
 624                 dev_err(&pdev->dev, "Error reading remote spad %d\n", VERSION);
 625                 goto out;
 626         }
 627
 628         if (val != NTB_TRANSPORT_VERSION)
 629                 goto out;
 630         dev_dbg(&pdev->dev, "Remote version = %d\n", val);
 631
 632         rc = ntb_read_remote_spad(ndev, NUM_QPS, &val);
 633         if (rc) {
 634                 dev_err(&pdev->dev, "Error reading remote spad %d\n", NUM_QPS);
 635                 goto out;
 636         }
 637
 638         if (val != nt->max_qps)
 639                 goto out;
 640         dev_dbg(&pdev->dev, "Remote max number of qps = %d\n", val);
 641
 642         rc = ntb_read_remote_spad(ndev, MW0_SZ, &val);
 643         if (rc) {
 644                 dev_err(&pdev->dev, "Error reading remote spad %d\n", MW0_SZ);
 645                 goto out;
 646         }
 647
 648         if (!val)
 649                 goto out;
 650         dev_dbg(&pdev->dev, "Remote MW0 size = %d\n", val);
 651
 652         rc = ntb_set_mw(nt, 0, val);
 653         if (rc)
 654                 goto out;
 655
 656         rc = ntb_read_remote_spad(ndev, MW1_SZ, &val);
 657         if (rc) {
 658                 dev_err(&pdev->dev, "Error reading remote spad %d\n", MW1_SZ);
 659                 goto out;
 660         }
 661
 662         if (!val)
 663                 goto out;
 664         dev_dbg(&pdev->dev, "Remote MW1 size = %d\n", val);
 665
 666         rc = ntb_set_mw(nt, 1, val);
 667         if (rc)
 668                 goto out;
 669
 670         nt->transport_link = NTB_LINK_UP;
 671
 672         for (i = 0; i < nt->max_qps; i++) {
 673                 struct ntb_transport_qp *qp = &nt->qps[i];
 674
 675                 ntb_transport_setup_qp_mw(nt, i);
 676
 677                 if (qp->client_ready == NTB_LINK_UP)
 678                         schedule_delayed_work(&qp->link_work, 0);
 679         }
 680
 681         return;
 682
 683 out:
 684         if (ntb_hw_link_status(ndev))
 685                 schedule_delayed_work(&nt->link_work,
 686                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 687 }
 688
 689 static void ntb_qp_link_work(struct work_struct *work)
 690 {
 691         struct ntb_transport_qp *qp = container_of(work,
 692                                                    struct ntb_transport_qp,
 693                                                    link_work.work);
 694         struct pci_dev *pdev = ntb_query_pdev(qp->ndev);
 695         struct ntb_transport *nt = qp->transport;
 696         int rc, val;
 697
 698         WARN_ON(nt->transport_link != NTB_LINK_UP);
 699
 700         rc = ntb_read_local_spad(nt->ndev, QP_LINKS, &val);
 701         if (rc) {
 702                 dev_err(&pdev->dev, "Error reading spad %d\n", QP_LINKS);
 703                 return;
 704         }
 705
 706         rc = ntb_write_remote_spad(nt->ndev, QP_LINKS, val | 1 << qp->qp_num);
 707         if (rc)
 708                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
 709                         val | 1 << qp->qp_num, QP_LINKS);
 710
 711         /* query remote spad for qp ready bits */
 712         rc = ntb_read_remote_spad(nt->ndev, QP_LINKS, &val);
 713         if (rc)
 714                 dev_err(&pdev->dev, "Error reading remote spad %d\n", QP_LINKS);
 715
 716         dev_dbg(&pdev->dev, "Remote QP link status = %x\n", val);
 717
 718         /* See if the remote side is up */
 719         if (1 << qp->qp_num & val) {
 720                 qp->qp_link = NTB_LINK_UP;
 721
 722                 dev_info(&pdev->dev, "qp %d: Link Up\n", qp->qp_num);
 723                 if (qp->event_handler)
 724                         qp->event_handler(qp->cb_data, NTB_LINK_UP);
 725         } else if (nt->transport_link == NTB_LINK_UP)
 726                 schedule_delayed_work(&qp->link_work,
 727                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 728 }
 729
 730 static void ntb_transport_init_queue(struct ntb_transport *nt,
 731                                      unsigned int qp_num)
 732 {
 733         struct ntb_transport_qp *qp;
 734
 735         qp = &nt->qps[qp_num];
 736         qp->qp_num = qp_num;
 737         qp->transport = nt;
 738         qp->ndev = nt->ndev;
 739         qp->qp_link = NTB_LINK_DOWN;
 740         qp->client_ready = NTB_LINK_DOWN;
 741         qp->event_handler = NULL;
 742
 743         if (nt->debugfs_dir) {
 744                 char debugfs_name[4];
 745
 746                 snprintf(debugfs_name, 4, "qp%d", qp_num);
 747                 qp->debugfs_dir = debugfs_create_dir(debugfs_name,
 748                                                      nt->debugfs_dir);
 749
 750                 qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR,
 751                                                         qp->debugfs_dir, qp,
 752                                                         &ntb_qp_debugfs_stats);
 753         }
 754
 755         INIT_DELAYED_WORK(&qp->link_work, ntb_qp_link_work);
 756
 757         spin_lock_init(&qp->ntb_rx_pend_q_lock);
 758         spin_lock_init(&qp->ntb_rx_free_q_lock);
 759         spin_lock_init(&qp->ntb_tx_free_q_lock);
 760
 761         INIT_LIST_HEAD(&qp->rx_pend_q);
 762         INIT_LIST_HEAD(&qp->rx_free_q);
 763         INIT_LIST_HEAD(&qp->tx_free_q);
 764 }
 765
 766 int ntb_transport_init(struct pci_dev *pdev)
 767 {
 768         struct ntb_transport *nt;
 769         int rc, i;
 770
 771         nt = kzalloc(sizeof(struct ntb_transport), GFP_KERNEL);
 772         if (!nt)
 773                 return -ENOMEM;
 774
 775         if (debugfs_initialized())
 776                 nt->debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
 777         else
 778                 nt->debugfs_dir = NULL;
 779
 780         nt->ndev = ntb_register_transport(pdev, nt);
 781         if (!nt->ndev) {
 782                 rc = -EIO;
 783                 goto err;
 784         }
 785
 786         nt->max_qps = min(nt->ndev->max_cbs, max_num_clients);
 787
 788         nt->qps = kcalloc(nt->max_qps, sizeof(struct ntb_transport_qp),
 789                           GFP_KERNEL);
 790         if (!nt->qps) {
 791                 rc = -ENOMEM;
 792                 goto err1;
 793         }
 794
 795         nt->qp_bitmap = ((u64) 1 << nt->max_qps) - 1;
 796
 797         for (i = 0; i < nt->max_qps; i++)
 798                 ntb_transport_init_queue(nt, i);
 799
 800         INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work);
 801
 802         rc = ntb_register_event_callback(nt->ndev,
 803                                          ntb_transport_event_callback);
 804         if (rc)
 805                 goto err2;
 806
 807         INIT_LIST_HEAD(&nt->client_devs);
 808         rc = ntb_bus_init(nt);
 809         if (rc)
 810                 goto err3;
 811
 812         if (ntb_hw_link_status(nt->ndev))
 813                 schedule_delayed_work(&nt->link_work, 0);
 814
 815         return 0;
 816
 817 err3:
 818         ntb_unregister_event_callback(nt->ndev);
 819 err2:
 820         kfree(nt->qps);
 821 err1:
 822         ntb_unregister_transport(nt->ndev);
 823 err:
 824         debugfs_remove_recursive(nt->debugfs_dir);
 825         kfree(nt);
 826         return rc;
 827 }
 828
 829 void ntb_transport_free(void *transport)
 830 {
 831         struct ntb_transport *nt = transport;
 832         struct pci_dev *pdev;
 833         int i;
 834
 835         nt->transport_link = NTB_LINK_DOWN;
 836
 837         /* verify that all the qp's are freed */
 838         for (i = 0; i < nt->max_qps; i++)
 839                 if (!test_bit(i, &nt->qp_bitmap))
 840                         ntb_transport_free_queue(&nt->qps[i]);
 841
 842         ntb_bus_remove(nt);
 843
 844         cancel_delayed_work_sync(&nt->link_work);
 845
 846         debugfs_remove_recursive(nt->debugfs_dir);
 847
 848         ntb_unregister_event_callback(nt->ndev);
 849
 850         pdev = ntb_query_pdev(nt->ndev);
 851
 852         for (i = 0; i < NTB_NUM_MW; i++)
 853                 if (nt->mw[i].virt_addr)
 854                         dma_free_coherent(&pdev->dev, nt->mw[i].size,
 855                                           nt->mw[i].virt_addr,
 856                                           nt->mw[i].dma_addr);
 857
 858         kfree(nt->qps);
 859         ntb_unregister_transport(nt->ndev);
 860         kfree(nt);
 861 }
 862
 863 static void ntb_rx_copy_task(struct ntb_transport_qp *qp,
 864                              struct ntb_queue_entry *entry, void *offset)
 865 {
 866
 867         struct ntb_payload_header *hdr;
 868
 869         BUG_ON(offset < qp->rx_buff_begin ||
 870                offset + transport_mtu >= qp->rx_buff_end);
 871
 872         hdr = offset + transport_mtu - sizeof(struct ntb_payload_header);
 873         entry->len = hdr->len;
 874
 875         memcpy(entry->buf, offset, entry->len);
 876
 877         /* Ensure that the data is fully copied out before clearing the flag */
 878         wmb();
 879         hdr->flags = 0;
 880
 881         if (qp->rx_handler && qp->client_ready == NTB_LINK_UP)
 882                 qp->rx_handler(qp, qp->cb_data, entry->cb_data, entry->len);
 883
 884         ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry, &qp->rx_free_q);
 885 }
 886
 887 static int ntb_process_rxc(struct ntb_transport_qp *qp)
 888 {
 889         struct ntb_payload_header *hdr;
 890         struct ntb_queue_entry *entry;
 891         void *offset;
 892
 893         entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q);
 894         if (!entry) {
 895                 hdr = offset + transport_mtu -
 896                       sizeof(struct ntb_payload_header);
 897                 dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
 898                         "no buffer - HDR ver %llu, len %d, flags %x\n",
 899                         hdr->ver, hdr->len, hdr->flags);
 900                 qp->rx_err_no_buf++;
 901                 return -ENOMEM;
 902         }
 903
 904         offset = qp->rx_offset;
 905         hdr = offset + transport_mtu - sizeof(struct ntb_payload_header);
 906
 907         if (!(hdr->flags & DESC_DONE_FLAG)) {
 908                 ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
 909                                   &qp->rx_pend_q);
 910                 qp->rx_ring_empty++;
 911                 return -EAGAIN;
 912         }
 913
 914         if (hdr->ver != qp->rx_pkts) {
 915                 dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
 916                         "qp %d: version mismatch, expected %llu - got %llu\n",
 917                         qp->qp_num, qp->rx_pkts, hdr->ver);
 918                 ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
 919                                   &qp->rx_pend_q);
 920                 qp->rx_err_ver++;
 921                 return -EIO;
 922         }
 923
 924         if (hdr->flags & LINK_DOWN_FLAG) {
 925                 ntb_qp_link_down(qp);
 926
 927                 ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
 928                                   &qp->rx_pend_q);
 929
 930                 /* Ensure that the data is fully copied out before clearing the
 931                  * done flag
 932                  */
 933                 wmb();
 934                 hdr->flags = 0;
 935                 goto out;
 936         }
 937
 938         dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
 939                 "rx offset %p, ver %llu - %d payload received, buf size %d\n",
 940                 qp->rx_offset, hdr->ver, hdr->len, entry->len);
 941
 942         if (hdr->len <= entry->len)
 943                 ntb_rx_copy_task(qp, entry, offset);
 944         else {
 945                 ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
 946                                   &qp->rx_pend_q);
 947
 948                 /* Ensure that the data is fully copied out before clearing the
 949                  * done flag
 950                  */
 951                 wmb();
 952                 hdr->flags = 0;
 953                 qp->rx_err_oflow++;
 954                 dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
 955                         "RX overflow! Wanted %d got %d\n",
 956                         hdr->len, entry->len);
 957         }
 958
 959         qp->rx_bytes += hdr->len;
 960         qp->rx_pkts++;
 961
 962 out:
 963         qp->rx_offset += transport_mtu;
 964         if (qp->rx_offset + transport_mtu >= qp->rx_buff_end)
 965                 qp->rx_offset = qp->rx_buff_begin;
 966
 967         return 0;
 968 }
 969
 970 static void ntb_transport_rx(unsigned long data)
 971 {
 972         struct ntb_transport_qp *qp = (struct ntb_transport_qp *)data;
 973         int rc;
 974
 975         do {
 976                 rc = ntb_process_rxc(qp);
 977         } while (!rc);
 978 }
 979
 980 static void ntb_transport_rxc_db(void *data, int db_num)
 981 {
 982         struct ntb_transport_qp *qp = data;
 983
 984         dev_dbg(&ntb_query_pdev(qp->ndev)->dev, "%s: doorbell %d received\n",
 985                 __func__, db_num);
 986
 987         tasklet_schedule(&qp->rx_work);
 988 }
 989
 990 static void ntb_tx_copy_task(struct ntb_transport_qp *qp,
 991                              struct ntb_queue_entry *entry,
 992                              void *offset)
 993 {
 994         struct ntb_payload_header *hdr;
 995
 996         BUG_ON(offset < qp->tx_mw_begin ||
 997                offset + transport_mtu >= qp->tx_mw_end);
 998
 999         memcpy_toio(offset, entry->buf, entry->len);
1000
1001         hdr = offset + transport_mtu - sizeof(struct ntb_payload_header);
1002         hdr->len = entry->len;
1003         hdr->ver = qp->tx_pkts;
1004
1005         /* Ensure that the data is fully copied out before setting the flag */
1006         mmiowb();
1007         hdr->flags = entry->flags | DESC_DONE_FLAG;
1008
1009         ntb_ring_sdb(qp->ndev, qp->qp_num);
1010
1011         /* The entry length can only be zero if the packet is intended to be a
1012          * "link down" or similar.  Since no payload is being sent in these
1013          * cases, there is nothing to add to the completion queue.
1014          */
1015         if (entry->len > 0) {
1016                 qp->tx_bytes += entry->len;
1017
1018                 if (qp->tx_handler)
1019                         qp->tx_handler(qp, qp->cb_data, entry->cb_data,
1020                                        entry->len);
1021         }
1022
1023         ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q);
1024 }
1025
1026 static int ntb_process_tx(struct ntb_transport_qp *qp,
1027                           struct ntb_queue_entry *entry)
1028 {
1029         struct ntb_payload_header *hdr;
1030         void *offset;
1031
1032         offset = qp->tx_offset;
1033         hdr = offset + transport_mtu - sizeof(struct ntb_payload_header);
1034
1035         dev_dbg(&ntb_query_pdev(qp->ndev)->dev, "%lld - offset %p, tx %p, entry len %d flags %x buff %p\n",
1036                  qp->tx_pkts, offset, qp->tx_offset, entry->len, entry->flags,
1037                  entry->buf);
1038         if (hdr->flags) {
1039                 qp->tx_ring_full++;
1040                 return -EAGAIN;
1041         }
1042
1043         if (entry->len > transport_mtu - sizeof(struct ntb_payload_header)) {
1044                 if (qp->tx_handler)
1045                         qp->tx_handler(qp->cb_data, qp, NULL, -EIO);
1046
1047                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1048                              &qp->tx_free_q);
1049                 return 0;
1050         }
1051
1052         ntb_tx_copy_task(qp, entry, offset);
1053
1054         qp->tx_offset += transport_mtu;
1055         if (qp->tx_offset + transport_mtu >= qp->tx_mw_end)
1056                 qp->tx_offset = qp->tx_mw_begin;
1057
1058         qp->tx_pkts++;
1059
1060         return 0;
1061 }
1062
1063 static void ntb_send_link_down(struct ntb_transport_qp *qp)
1064 {
1065         struct pci_dev *pdev = ntb_query_pdev(qp->ndev);
1066         struct ntb_queue_entry *entry;
1067         int i, rc;
1068
1069         if (qp->qp_link == NTB_LINK_DOWN)
1070                 return;
1071
1072         qp->qp_link = NTB_LINK_DOWN;
1073         dev_info(&pdev->dev, "qp %d: Link Down\n", qp->qp_num);
1074
1075         for (i = 0; i < NTB_LINK_DOWN_TIMEOUT; i++) {
1076                 entry = ntb_list_rm(&qp->ntb_tx_free_q_lock,
1077                                          &qp->tx_free_q);
1078                 if (entry)
1079                         break;
1080                 msleep(100);
1081         }
1082
1083         if (!entry)
1084                 return;
1085
1086         entry->cb_data = NULL;
1087         entry->buf = NULL;
1088         entry->len = 0;
1089         entry->flags = LINK_DOWN_FLAG;
1090
1091         rc = ntb_process_tx(qp, entry);
1092         if (rc)
1093                 dev_err(&pdev->dev, "ntb: QP%d unable to send linkdown msg\n",
1094                         qp->qp_num);
1095 }
1096
1097 /**
1098  * ntb_transport_create_queue - Create a new NTB transport layer queue
1099  * @rx_handler: receive callback function
1100  * @tx_handler: transmit callback function
1101  * @event_handler: event callback function
1102  *
1103  * Create a new NTB transport layer queue and provide the queue with a callback
1104  * routine for both transmit and receive.  The receive callback routine will be
1105  * used to pass up data when the transport has received it on the queue.   The
1106  * transmit callback routine will be called when the transport has completed the
1107  * transmission of the data on the queue and the data is ready to be freed.
1108  *
1109  * RETURNS: pointer to newly created ntb_queue, NULL on error.
1110  */
1111 struct ntb_transport_qp *
1112 ntb_transport_create_queue(void *data, struct pci_dev *pdev,
1113                            const struct ntb_queue_handlers *handlers)
1114 {
1115         struct ntb_queue_entry *entry;
1116         struct ntb_transport_qp *qp;
1117         struct ntb_transport *nt;
1118         unsigned int free_queue;
1119         int rc, i;
1120
1121         nt = ntb_find_transport(pdev);
1122         if (!nt)
1123                 goto err;
1124
1125         free_queue = ffs(nt->qp_bitmap);
1126         if (!free_queue)
1127                 goto err;
1128
1129         /* decrement free_queue to make it zero based */
1130         free_queue--;
1131
1132         clear_bit(free_queue, &nt->qp_bitmap);
1133
1134         qp = &nt->qps[free_queue];
1135         qp->cb_data = data;
1136         qp->rx_handler = handlers->rx_handler;
1137         qp->tx_handler = handlers->tx_handler;
1138         qp->event_handler = handlers->event_handler;
1139
1140         for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
1141                 entry = kzalloc(sizeof(struct ntb_queue_entry), GFP_ATOMIC);
1142                 if (!entry)
1143                         goto err1;
1144
1145                 ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry,
1146                                   &qp->rx_free_q);
1147         }
1148
1149         for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
1150                 entry = kzalloc(sizeof(struct ntb_queue_entry), GFP_ATOMIC);
1151                 if (!entry)
1152                         goto err2;
1153
1154                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1155                                   &qp->tx_free_q);
1156         }
1157
1158         tasklet_init(&qp->rx_work, ntb_transport_rx, (unsigned long) qp);
1159
1160         rc = ntb_register_db_callback(qp->ndev, free_queue, qp,
1161                                       ntb_transport_rxc_db);
1162         if (rc)
1163                 goto err3;
1164
1165         dev_info(&pdev->dev, "NTB Transport QP %d created\n", qp->qp_num);
1166
1167         return qp;
1168
1169 err3:
1170         tasklet_disable(&qp->rx_work);
1171 err2:
1172         while ((entry =
1173                 ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1174                 kfree(entry);
1175 err1:
1176         while ((entry =
1177                 ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q)))
1178                 kfree(entry);
1179         set_bit(free_queue, &nt->qp_bitmap);
1180 err:
1181         return NULL;
1182 }
1183 EXPORT_SYMBOL_GPL(ntb_transport_create_queue);
1184
1185 /**
1186  * ntb_transport_free_queue - Frees NTB transport queue
1187  * @qp: NTB queue to be freed
1188  *
1189  * Frees NTB transport queue
1190  */
1191 void ntb_transport_free_queue(struct ntb_transport_qp *qp)
1192 {
1193         struct pci_dev *pdev = ntb_query_pdev(qp->ndev);
1194         struct ntb_queue_entry *entry;
1195
1196         if (!qp)
1197                 return;
1198
1199         cancel_delayed_work_sync(&qp->link_work);
1200
1201         ntb_unregister_db_callback(qp->ndev, qp->qp_num);
1202         tasklet_disable(&qp->rx_work);
1203
1204         while ((entry =
1205                 ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q)))
1206                 kfree(entry);
1207
1208         while ((entry =
1209                 ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q))) {
1210                 dev_warn(&pdev->dev, "Freeing item from a non-empty queue\n");
1211                 kfree(entry);
1212         }
1213
1214         while ((entry =
1215                 ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1216                 kfree(entry);
1217
1218         set_bit(qp->qp_num, &qp->transport->qp_bitmap);
1219
1220         dev_info(&pdev->dev, "NTB Transport QP %d freed\n", qp->qp_num);
1221 }
1222 EXPORT_SYMBOL_GPL(ntb_transport_free_queue);
1223
1224 /**
1225  * ntb_transport_rx_remove - Dequeues enqueued rx packet
1226  * @qp: NTB queue to be freed
1227  * @len: pointer to variable to write enqueued buffers length
1228  *
1229  * Dequeues unused buffers from receive queue.  Should only be used during
1230  * shutdown of qp.
1231  *
1232  * RETURNS: NULL error value on error, or void* for success.
1233  */
1234 void *ntb_transport_rx_remove(struct ntb_transport_qp *qp, unsigned int *len)
1235 {
1236         struct ntb_queue_entry *entry;
1237         void *buf;
1238
1239         if (!qp || qp->client_ready == NTB_LINK_UP)
1240                 return NULL;
1241
1242         entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q);
1243         if (!entry)
1244                 return NULL;
1245
1246         buf = entry->cb_data;
1247         *len = entry->len;
1248
1249         ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry,
1250                           &qp->rx_free_q);
1251
1252         return buf;
1253 }
1254 EXPORT_SYMBOL_GPL(ntb_transport_rx_remove);
1255
1256 /**
1257  * ntb_transport_rx_enqueue - Enqueue a new NTB queue entry
1258  * @qp: NTB transport layer queue the entry is to be enqueued on
1259  * @cb: per buffer pointer for callback function to use
1260  * @data: pointer to data buffer that incoming packets will be copied into
1261  * @len: length of the data buffer
1262  *
1263  * Enqueue a new receive buffer onto the transport queue into which a NTB
1264  * payload can be received into.
1265  *
1266  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
1267  */
1268 int ntb_transport_rx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
1269                              unsigned int len)
1270 {
1271         struct ntb_queue_entry *entry;
1272
1273         if (!qp)
1274                 return -EINVAL;
1275
1276         entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q);
1277         if (!entry)
1278                 return -ENOMEM;
1279
1280         entry->cb_data = cb;
1281         entry->buf = data;
1282         entry->len = len;
1283
1284         ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
1285                           &qp->rx_pend_q);
1286
1287         return 0;
1288 }
1289 EXPORT_SYMBOL_GPL(ntb_transport_rx_enqueue);
1290
1291 /**
1292  * ntb_transport_tx_enqueue - Enqueue a new NTB queue entry
1293  * @qp: NTB transport layer queue the entry is to be enqueued on
1294  * @cb: per buffer pointer for callback function to use
1295  * @data: pointer to data buffer that will be sent
1296  * @len: length of the data buffer
1297  *
1298  * Enqueue a new transmit buffer onto the transport queue from which a NTB
1299  * payload will be transmitted.  This assumes that a lock is behing held to
1300  * serialize access to the qp.
1301  *
1302  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
1303  */
1304 int ntb_transport_tx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
1305                              unsigned int len)
1306 {
1307         struct ntb_queue_entry *entry;
1308         int rc;
1309
1310         if (!qp || qp->qp_link != NTB_LINK_UP || !len)
1311                 return -EINVAL;
1312
1313         entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1314         if (!entry)
1315                 return -ENOMEM;
1316
1317         entry->cb_data = cb;
1318         entry->buf = data;
1319         entry->len = len;
1320         entry->flags = 0;
1321
1322         rc = ntb_process_tx(qp, entry);
1323         if (rc)
1324                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1325                              &qp->tx_free_q);
1326
1327         return rc;
1328 }
1329 EXPORT_SYMBOL_GPL(ntb_transport_tx_enqueue);
1330
1331 /**
1332  * ntb_transport_link_up - Notify NTB transport of client readiness to use queue
1333  * @qp: NTB transport layer queue to be enabled
1334  *
1335  * Notify NTB transport layer of client readiness to use queue
1336  */
1337 void ntb_transport_link_up(struct ntb_transport_qp *qp)
1338 {
1339         if (!qp)
1340                 return;
1341
1342         qp->client_ready = NTB_LINK_UP;
1343
1344         if (qp->transport->transport_link == NTB_LINK_UP)
1345                 schedule_delayed_work(&qp->link_work, 0);
1346 }
1347 EXPORT_SYMBOL_GPL(ntb_transport_link_up);
1348
1349 /**
1350  * ntb_transport_link_down - Notify NTB transport to no longer enqueue data
1351  * @qp: NTB transport layer queue to be disabled
1352  *
1353  * Notify NTB transport layer of client's desire to no longer receive data on
1354  * transport queue specified.  It is the client's responsibility to ensure all
1355  * entries on queue are purged or otherwise handled appropraitely.
1356  */
1357 void ntb_transport_link_down(struct ntb_transport_qp *qp)
1358 {
1359         struct pci_dev *pdev = ntb_query_pdev(qp->ndev);
1360         int rc, val;
1361
1362         if (!qp)
1363                 return;
1364
1365         qp->client_ready = NTB_LINK_DOWN;
1366
1367         rc = ntb_read_local_spad(qp->ndev, QP_LINKS, &val);
1368         if (rc) {
1369                 dev_err(&pdev->dev, "Error reading spad %d\n", QP_LINKS);
1370                 return;
1371         }
1372
1373         rc = ntb_write_remote_spad(qp->ndev, QP_LINKS,
1374                                    val & ~(1 << qp->qp_num));
1375         if (rc)
1376                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
1377                         val & ~(1 << qp->qp_num), QP_LINKS);
1378
1379         if (qp->qp_link == NTB_LINK_UP)
1380                 ntb_send_link_down(qp);
1381         else
1382                 cancel_delayed_work_sync(&qp->link_work);
1383 }
1384 EXPORT_SYMBOL_GPL(ntb_transport_link_down);
1385
1386 /**
1387  * ntb_transport_link_query - Query transport link state
1388  * @qp: NTB transport layer queue to be queried
1389  *
1390  * Query connectivity to the remote system of the NTB transport queue
1391  *
1392  * RETURNS: true for link up or false for link down
1393  */
1394 bool ntb_transport_link_query(struct ntb_transport_qp *qp)
1395 {
1396         return qp->qp_link == NTB_LINK_UP;
1397 }
1398 EXPORT_SYMBOL_GPL(ntb_transport_link_query);
1399
1400 /**
1401  * ntb_transport_qp_num - Query the qp number
1402  * @qp: NTB transport layer queue to be queried
1403  *
1404  * Query qp number of the NTB transport queue
1405  *
1406  * RETURNS: a zero based number specifying the qp number
1407  */
1408 unsigned char ntb_transport_qp_num(struct ntb_transport_qp *qp)
1409 {
1410         return qp->qp_num;
1411 }
1412 EXPORT_SYMBOL_GPL(ntb_transport_qp_num);
1413
1414 /**
1415  * ntb_transport_max_size - Query the max payload size of a qp
1416  * @qp: NTB transport layer queue to be queried
1417  *
1418  * Query the maximum payload size permissible on the given qp
1419  *
1420  * RETURNS: the max payload size of a qp
1421  */
1422 unsigned int
1423 ntb_transport_max_size(__attribute__((unused)) struct ntb_transport_qp *qp)
1424 {
1425         return transport_mtu - sizeof(struct ntb_payload_header);
1426 }
1427 EXPORT_SYMBOL_GPL(ntb_transport_max_size);