drivers/ntb/ntb_transport.c

   1 /*
   2  * This file is provided under a dual BSD/GPLv2 license.  When using or
   3  *   redistributing this file, you may do so under either license.
   4  *
   5  *   GPL LICENSE SUMMARY
   6  *
   7  *   Copyright(c) 2012 Intel Corporation. All rights reserved.
   8  *
   9  *   This program is free software; you can redistribute it and/or modify
  10  *   it under the terms of version 2 of the GNU General Public License as
  11  *   published by the Free Software Foundation.
  12  *
  13  *   BSD LICENSE
  14  *
  15  *   Copyright(c) 2012 Intel Corporation. All rights reserved.
  16  *
  17  *   Redistribution and use in source and binary forms, with or without
  18  *   modification, are permitted provided that the following conditions
  19  *   are met:
  20  *
  21  *     * Redistributions of source code must retain the above copyright
  22  *       notice, this list of conditions and the following disclaimer.
  23  *     * Redistributions in binary form must reproduce the above copy
  24  *       notice, this list of conditions and the following disclaimer in
  25  *       the documentation and/or other materials provided with the
  26  *       distribution.
  27  *     * Neither the name of Intel Corporation nor the names of its
  28  *       contributors may be used to endorse or promote products derived
  29  *       from this software without specific prior written permission.
  30  *
  31  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  32  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  33  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  34  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  35  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  36  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  37  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  38  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  39  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  40  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  41  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  42  *
  43  * Intel PCIe NTB Linux driver
  44  *
  45  * Contact Information:
  46  * Jon Mason <jon.mason@intel.com>
  47  */
  48 #include <linux/debugfs.h>
  49 #include <linux/delay.h>
  50 #include <linux/dma-mapping.h>
  51 #include <linux/errno.h>
  52 #include <linux/export.h>
  53 #include <linux/interrupt.h>
  54 #include <linux/module.h>
  55 #include <linux/pci.h>
  56 #include <linux/slab.h>
  57 #include <linux/types.h>
  58 #include <linux/ntb.h>
  59 #include "ntb_hw.h"
  60
  61 #define NTB_TRANSPORT_VERSION   1
  62
  63 static unsigned int transport_mtu = 0x401E;
  64 module_param(transport_mtu, uint, 0644);
  65 MODULE_PARM_DESC(transport_mtu, "Maximum size of NTB transport packets");
  66
  67 static unsigned char max_num_clients = 2;
  68 module_param(max_num_clients, byte, 0644);
  69 MODULE_PARM_DESC(max_num_clients, "Maximum number of NTB transport clients");
  70
  71 struct ntb_queue_entry {
  72         /* ntb_queue list reference */
  73         struct list_head entry;
  74         /* pointers to data to be transfered */
  75         void *cb_data;
  76         void *buf;
  77         unsigned int len;
  78         unsigned int flags;
  79 };
  80
  81 struct ntb_transport_qp {
  82         struct ntb_transport *transport;
  83         struct ntb_device *ndev;
  84         void *cb_data;
  85
  86         bool client_ready;
  87         bool qp_link;
  88         u8 qp_num;      /* Only 64 QP's are allowed.  0-63 */
  89
  90         void (*tx_handler) (struct ntb_transport_qp *qp, void *qp_data,
  91                             void *data, int len);
  92         struct list_head tx_free_q;
  93         spinlock_t ntb_tx_free_q_lock;
  94         void *tx_mw_begin;
  95         void *tx_mw_end;
  96         void *tx_offset;
  97         unsigned int tx_max_frame;
  98
  99         void (*rx_handler) (struct ntb_transport_qp *qp, void *qp_data,
 100                             void *data, int len);
 101         struct tasklet_struct rx_work;
 102         struct list_head rx_pend_q;
 103         struct list_head rx_free_q;
 104         spinlock_t ntb_rx_pend_q_lock;
 105         spinlock_t ntb_rx_free_q_lock;
 106         void *rx_buff_begin;
 107         void *rx_buff_end;
 108         void *rx_offset;
 109         unsigned int rx_max_frame;
 110
 111         void (*event_handler) (void *data, int status);
 112         struct delayed_work link_work;
 113         struct work_struct link_cleanup;
 114
 115         struct dentry *debugfs_dir;
 116         struct dentry *debugfs_stats;
 117
 118         /* Stats */
 119         u64 rx_bytes;
 120         u64 rx_pkts;
 121         u64 rx_ring_empty;
 122         u64 rx_err_no_buf;
 123         u64 rx_err_oflow;
 124         u64 rx_err_ver;
 125         u64 tx_bytes;
 126         u64 tx_pkts;
 127         u64 tx_ring_full;
 128 };
 129
 130 struct ntb_transport_mw {
 131         size_t size;
 132         void *virt_addr;
 133         dma_addr_t dma_addr;
 134 };
 135
 136 struct ntb_transport_client_dev {
 137         struct list_head entry;
 138         struct device dev;
 139 };
 140
 141 struct ntb_transport {
 142         struct list_head entry;
 143         struct list_head client_devs;
 144
 145         struct ntb_device *ndev;
 146         struct ntb_transport_mw mw[NTB_NUM_MW];
 147         struct ntb_transport_qp *qps;
 148         unsigned int max_qps;
 149         unsigned long qp_bitmap;
 150         bool transport_link;
 151         struct delayed_work link_work;
 152         struct work_struct link_cleanup;
 153         struct dentry *debugfs_dir;
 154 };
 155
 156 enum {
 157         DESC_DONE_FLAG = 1 << 0,
 158         LINK_DOWN_FLAG = 1 << 1,
 159 };
 160
 161 struct ntb_payload_header {
 162         u64 ver;
 163         unsigned int len;
 164         unsigned int flags;
 165 };
 166
 167 enum {
 168         VERSION = 0,
 169         MW0_SZ,
 170         MW1_SZ,
 171         NUM_QPS,
 172         QP_LINKS,
 173         MAX_SPAD,
 174 };
 175
 176 #define QP_TO_MW(qp)            ((qp) % NTB_NUM_MW)
 177 #define NTB_QP_DEF_NUM_ENTRIES  100
 178 #define NTB_LINK_DOWN_TIMEOUT   10
 179
 180 static int ntb_match_bus(struct device *dev, struct device_driver *drv)
 181 {
 182         return !strncmp(dev_name(dev), drv->name, strlen(drv->name));
 183 }
 184
 185 static int ntb_client_probe(struct device *dev)
 186 {
 187         const struct ntb_client *drv = container_of(dev->driver,
 188                                                     struct ntb_client, driver);
 189         struct pci_dev *pdev = container_of(dev->parent, struct pci_dev, dev);
 190         int rc = -EINVAL;
 191
 192         get_device(dev);
 193         if (drv && drv->probe)
 194                 rc = drv->probe(pdev);
 195         if (rc)
 196                 put_device(dev);
 197
 198         return rc;
 199 }
 200
 201 static int ntb_client_remove(struct device *dev)
 202 {
 203         const struct ntb_client *drv = container_of(dev->driver,
 204                                                     struct ntb_client, driver);
 205         struct pci_dev *pdev = container_of(dev->parent, struct pci_dev, dev);
 206
 207         if (drv && drv->remove)
 208                 drv->remove(pdev);
 209
 210         put_device(dev);
 211
 212         return 0;
 213 }
 214
 215 static struct bus_type ntb_bus_type = {
 216         .name = "ntb_bus",
 217         .match = ntb_match_bus,
 218         .probe = ntb_client_probe,
 219         .remove = ntb_client_remove,
 220 };
 221
 222 static LIST_HEAD(ntb_transport_list);
 223
 224 static int ntb_bus_init(struct ntb_transport *nt)
 225 {
 226         if (list_empty(&ntb_transport_list)) {
 227                 int rc = bus_register(&ntb_bus_type);
 228                 if (rc)
 229                         return rc;
 230         }
 231
 232         list_add(&nt->entry, &ntb_transport_list);
 233
 234         return 0;
 235 }
 236
 237 static void ntb_bus_remove(struct ntb_transport *nt)
 238 {
 239         struct ntb_transport_client_dev *client_dev, *cd;
 240
 241         list_for_each_entry_safe(client_dev, cd, &nt->client_devs, entry) {
 242                 dev_err(client_dev->dev.parent, "%s still attached to bus, removing\n",
 243                         dev_name(&client_dev->dev));
 244                 list_del(&client_dev->entry);
 245                 device_unregister(&client_dev->dev);
 246         }
 247
 248         list_del(&nt->entry);
 249
 250         if (list_empty(&ntb_transport_list))
 251                 bus_unregister(&ntb_bus_type);
 252 }
 253
 254 static void ntb_client_release(struct device *dev)
 255 {
 256         struct ntb_transport_client_dev *client_dev;
 257         client_dev = container_of(dev, struct ntb_transport_client_dev, dev);
 258
 259         kfree(client_dev);
 260 }
 261
 262 /**
 263  * ntb_unregister_client_dev - Unregister NTB client device
 264  * @device_name: Name of NTB client device
 265  *
 266  * Unregister an NTB client device with the NTB transport layer
 267  */
 268 void ntb_unregister_client_dev(char *device_name)
 269 {
 270         struct ntb_transport_client_dev *client, *cd;
 271         struct ntb_transport *nt;
 272
 273         list_for_each_entry(nt, &ntb_transport_list, entry)
 274                 list_for_each_entry_safe(client, cd, &nt->client_devs, entry)
 275                         if (!strncmp(dev_name(&client->dev), device_name,
 276                                      strlen(device_name))) {
 277                                 list_del(&client->entry);
 278                                 device_unregister(&client->dev);
 279                         }
 280 }
 281 EXPORT_SYMBOL_GPL(ntb_unregister_client_dev);
 282
 283 /**
 284  * ntb_register_client_dev - Register NTB client device
 285  * @device_name: Name of NTB client device
 286  *
 287  * Register an NTB client device with the NTB transport layer
 288  */
 289 int ntb_register_client_dev(char *device_name)
 290 {
 291         struct ntb_transport_client_dev *client_dev;
 292         struct ntb_transport *nt;
 293         int rc;
 294
 295         if (list_empty(&ntb_transport_list))
 296                 return -ENODEV;
 297
 298         list_for_each_entry(nt, &ntb_transport_list, entry) {
 299                 struct device *dev;
 300
 301                 client_dev = kzalloc(sizeof(struct ntb_transport_client_dev),
 302                                      GFP_KERNEL);
 303                 if (!client_dev) {
 304                         rc = -ENOMEM;
 305                         goto err;
 306                 }
 307
 308                 dev = &client_dev->dev;
 309
 310                 /* setup and register client devices */
 311                 dev_set_name(dev, "%s", device_name);
 312                 dev->bus = &ntb_bus_type;
 313                 dev->release = ntb_client_release;
 314                 dev->parent = &ntb_query_pdev(nt->ndev)->dev;
 315
 316                 rc = device_register(dev);
 317                 if (rc) {
 318                         kfree(client_dev);
 319                         goto err;
 320                 }
 321
 322                 list_add_tail(&client_dev->entry, &nt->client_devs);
 323         }
 324
 325         return 0;
 326
 327 err:
 328         ntb_unregister_client_dev(device_name);
 329
 330         return rc;
 331 }
 332 EXPORT_SYMBOL_GPL(ntb_register_client_dev);
 333
 334 /**
 335  * ntb_register_client - Register NTB client driver
 336  * @drv: NTB client driver to be registered
 337  *
 338  * Register an NTB client driver with the NTB transport layer
 339  *
 340  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 341  */
 342 int ntb_register_client(struct ntb_client *drv)
 343 {
 344         drv->driver.bus = &ntb_bus_type;
 345
 346         if (list_empty(&ntb_transport_list))
 347                 return -ENODEV;
 348
 349         return driver_register(&drv->driver);
 350 }
 351 EXPORT_SYMBOL_GPL(ntb_register_client);
 352
 353 /**
 354  * ntb_unregister_client - Unregister NTB client driver
 355  * @drv: NTB client driver to be unregistered
 356  *
 357  * Unregister an NTB client driver with the NTB transport layer
 358  *
 359  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 360  */
 361 void ntb_unregister_client(struct ntb_client *drv)
 362 {
 363         driver_unregister(&drv->driver);
 364 }
 365 EXPORT_SYMBOL_GPL(ntb_unregister_client);
 366
 367 static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count,
 368                             loff_t *offp)
 369 {
 370         struct ntb_transport_qp *qp;
 371         char buf[1024];
 372         ssize_t ret, out_offset, out_count;
 373
 374         out_count = 1024;
 375
 376         qp = filp->private_data;
 377         out_offset = 0;
 378         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 379                                "NTB QP stats\n");
 380         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 381                                "rx_bytes - \t%llu\n", qp->rx_bytes);
 382         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 383                                "rx_pkts - \t%llu\n", qp->rx_pkts);
 384         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 385                                "rx_ring_empty - %llu\n", qp->rx_ring_empty);
 386         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 387                                "rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
 388         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 389                                "rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
 390         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 391                                "rx_err_ver - \t%llu\n", qp->rx_err_ver);
 392         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 393                                "rx_buff_begin - %p\n", qp->rx_buff_begin);
 394         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 395                                "rx_offset - \t%p\n", qp->rx_offset);
 396         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 397                                "rx_buff_end - \t%p\n", qp->rx_buff_end);
 398
 399         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 400                                "tx_bytes - \t%llu\n", qp->tx_bytes);
 401         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 402                                "tx_pkts - \t%llu\n", qp->tx_pkts);
 403         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 404                                "tx_ring_full - \t%llu\n", qp->tx_ring_full);
 405         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 406                                "tx_mw_begin - \t%p\n", qp->tx_mw_begin);
 407         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 408                                "tx_offset - \t%p\n", qp->tx_offset);
 409         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 410                                "tx_mw_end - \t%p\n", qp->tx_mw_end);
 411
 412         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 413                                "QP Link %s\n", (qp->qp_link == NTB_LINK_UP) ?
 414                                "Up" : "Down");
 415
 416         ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
 417         return ret;
 418 }
 419
 420 static const struct file_operations ntb_qp_debugfs_stats = {
 421         .owner = THIS_MODULE,
 422         .open = simple_open,
 423         .read = debugfs_read,
 424 };
 425
 426 static void ntb_list_add(spinlock_t *lock, struct list_head *entry,
 427                          struct list_head *list)
 428 {
 429         unsigned long flags;
 430
 431         spin_lock_irqsave(lock, flags);
 432         list_add_tail(entry, list);
 433         spin_unlock_irqrestore(lock, flags);
 434 }
 435
 436 static struct ntb_queue_entry *ntb_list_rm(spinlock_t *lock,
 437                                                 struct list_head *list)
 438 {
 439         struct ntb_queue_entry *entry;
 440         unsigned long flags;
 441
 442         spin_lock_irqsave(lock, flags);
 443         if (list_empty(list)) {
 444                 entry = NULL;
 445                 goto out;
 446         }
 447         entry = list_first_entry(list, struct ntb_queue_entry, entry);
 448         list_del(&entry->entry);
 449 out:
 450         spin_unlock_irqrestore(lock, flags);
 451
 452         return entry;
 453 }
 454
 455 static void ntb_transport_setup_qp_mw(struct ntb_transport *nt,
 456                                       unsigned int qp_num)
 457 {
 458         struct ntb_transport_qp *qp = &nt->qps[qp_num];
 459         unsigned int rx_size, num_qps_mw;
 460         u8 mw_num = QP_TO_MW(qp_num);
 461         void *offset;
 462
 463         WARN_ON(nt->mw[mw_num].virt_addr == 0);
 464
 465         if (nt->max_qps % NTB_NUM_MW && mw_num < nt->max_qps % NTB_NUM_MW)
 466                 num_qps_mw = nt->max_qps / NTB_NUM_MW + 1;
 467         else
 468                 num_qps_mw = nt->max_qps / NTB_NUM_MW;
 469
 470         rx_size = nt->mw[mw_num].size / num_qps_mw;
 471         qp->rx_buff_begin = nt->mw[mw_num].virt_addr +
 472                             (qp_num / NTB_NUM_MW * rx_size);
 473         qp->rx_buff_end = qp->rx_buff_begin + rx_size;
 474         qp->rx_offset = qp->rx_buff_begin;
 475         qp->rx_max_frame = min(transport_mtu, rx_size);
 476
 477         /* setup the hdr offsets with 0's */
 478         for (offset = qp->rx_buff_begin + qp->rx_max_frame -
 479                       sizeof(struct ntb_payload_header);
 480              offset < qp->rx_buff_end; offset += qp->rx_max_frame)
 481                 memset(offset, 0, sizeof(struct ntb_payload_header));
 482
 483         qp->rx_pkts = 0;
 484         qp->tx_pkts = 0;
 485 }
 486
 487 static int ntb_set_mw(struct ntb_transport *nt, int num_mw, unsigned int size)
 488 {
 489         struct ntb_transport_mw *mw = &nt->mw[num_mw];
 490         struct pci_dev *pdev = ntb_query_pdev(nt->ndev);
 491
 492         /* Alloc memory for receiving data.  Must be 4k aligned */
 493         mw->size = ALIGN(size, 4096);
 494
 495         mw->virt_addr = dma_alloc_coherent(&pdev->dev, mw->size, &mw->dma_addr,
 496                                            GFP_KERNEL);
 497         if (!mw->virt_addr) {
 498                 dev_err(&pdev->dev, "Unable to allocate MW buffer of size %d\n",
 499                        (int) mw->size);
 500                 return -ENOMEM;
 501         }
 502
 503         /* Notify HW the memory location of the receive buffer */
 504         ntb_set_mw_addr(nt->ndev, num_mw, mw->dma_addr);
 505
 506         return 0;
 507 }
 508
 509 static void ntb_qp_link_cleanup(struct work_struct *work)
 510 {
 511         struct ntb_transport_qp *qp = container_of(work,
 512                                                    struct ntb_transport_qp,
 513                                                    link_cleanup);
 514         struct ntb_transport *nt = qp->transport;
 515         struct pci_dev *pdev = ntb_query_pdev(nt->ndev);
 516
 517         if (qp->qp_link == NTB_LINK_DOWN) {
 518                 cancel_delayed_work_sync(&qp->link_work);
 519                 return;
 520         }
 521
 522         if (qp->event_handler)
 523                 qp->event_handler(qp->cb_data, NTB_LINK_DOWN);
 524
 525         dev_info(&pdev->dev, "qp %d: Link Down\n", qp->qp_num);
 526         qp->qp_link = NTB_LINK_DOWN;
 527
 528         if (nt->transport_link == NTB_LINK_UP)
 529                 schedule_delayed_work(&qp->link_work,
 530                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 531 }
 532
 533 static void ntb_qp_link_down(struct ntb_transport_qp *qp)
 534 {
 535         schedule_work(&qp->link_cleanup);
 536 }
 537
 538 static void ntb_transport_link_cleanup(struct work_struct *work)
 539 {
 540         struct ntb_transport *nt = container_of(work, struct ntb_transport,
 541                                                 link_cleanup);
 542         int i;
 543
 544         if (nt->transport_link == NTB_LINK_DOWN)
 545                 cancel_delayed_work_sync(&nt->link_work);
 546         else
 547                 nt->transport_link = NTB_LINK_DOWN;
 548
 549         /* Pass along the info to any clients */
 550         for (i = 0; i < nt->max_qps; i++)
 551                 if (!test_bit(i, &nt->qp_bitmap))
 552                         ntb_qp_link_down(&nt->qps[i]);
 553
 554         /* The scratchpad registers keep the values if the remote side
 555          * goes down, blast them now to give them a sane value the next
 556          * time they are accessed
 557          */
 558         for (i = 0; i < MAX_SPAD; i++)
 559                 ntb_write_local_spad(nt->ndev, i, 0);
 560 }
 561
 562 static void ntb_transport_event_callback(void *data, enum ntb_hw_event event)
 563 {
 564         struct ntb_transport *nt = data;
 565
 566         switch (event) {
 567         case NTB_EVENT_HW_LINK_UP:
 568                 schedule_delayed_work(&nt->link_work, 0);
 569                 break;
 570         case NTB_EVENT_HW_LINK_DOWN:
 571                 schedule_work(&nt->link_cleanup);
 572                 break;
 573         default:
 574                 BUG();
 575         }
 576 }
 577
 578 static void ntb_transport_link_work(struct work_struct *work)
 579 {
 580         struct ntb_transport *nt = container_of(work, struct ntb_transport,
 581                                                 link_work.work);
 582         struct ntb_device *ndev = nt->ndev;
 583         struct pci_dev *pdev = ntb_query_pdev(ndev);
 584         u32 val;
 585         int rc, i;
 586
 587         /* send the local info */
 588         rc = ntb_write_remote_spad(ndev, VERSION, NTB_TRANSPORT_VERSION);
 589         if (rc) {
 590                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
 591                         0, VERSION);
 592                 goto out;
 593         }
 594
 595         rc = ntb_write_remote_spad(ndev, MW0_SZ, ntb_get_mw_size(ndev, 0));
 596         if (rc) {
 597                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
 598                         (u32) ntb_get_mw_size(ndev, 0), MW0_SZ);
 599                 goto out;
 600         }
 601
 602         rc = ntb_write_remote_spad(ndev, MW1_SZ, ntb_get_mw_size(ndev, 1));
 603         if (rc) {
 604                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
 605                         (u32) ntb_get_mw_size(ndev, 1), MW1_SZ);
 606                 goto out;
 607         }
 608
 609         rc = ntb_write_remote_spad(ndev, NUM_QPS, nt->max_qps);
 610         if (rc) {
 611                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
 612                         nt->max_qps, NUM_QPS);
 613                 goto out;
 614         }
 615
 616         rc = ntb_read_local_spad(nt->ndev, QP_LINKS, &val);
 617         if (rc) {
 618                 dev_err(&pdev->dev, "Error reading spad %d\n", QP_LINKS);
 619                 goto out;
 620         }
 621
 622         rc = ntb_write_remote_spad(ndev, QP_LINKS, val);
 623         if (rc) {
 624                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
 625                         val, QP_LINKS);
 626                 goto out;
 627         }
 628
 629         /* Query the remote side for its info */
 630         rc = ntb_read_remote_spad(ndev, VERSION, &val);
 631         if (rc) {
 632                 dev_err(&pdev->dev, "Error reading remote spad %d\n", VERSION);
 633                 goto out;
 634         }
 635
 636         if (val != NTB_TRANSPORT_VERSION)
 637                 goto out;
 638         dev_dbg(&pdev->dev, "Remote version = %d\n", val);
 639
 640         rc = ntb_read_remote_spad(ndev, NUM_QPS, &val);
 641         if (rc) {
 642                 dev_err(&pdev->dev, "Error reading remote spad %d\n", NUM_QPS);
 643                 goto out;
 644         }
 645
 646         if (val != nt->max_qps)
 647                 goto out;
 648         dev_dbg(&pdev->dev, "Remote max number of qps = %d\n", val);
 649
 650         rc = ntb_read_remote_spad(ndev, MW0_SZ, &val);
 651         if (rc) {
 652                 dev_err(&pdev->dev, "Error reading remote spad %d\n", MW0_SZ);
 653                 goto out;
 654         }
 655
 656         if (!val)
 657                 goto out;
 658         dev_dbg(&pdev->dev, "Remote MW0 size = %d\n", val);
 659
 660         rc = ntb_set_mw(nt, 0, val);
 661         if (rc)
 662                 goto out;
 663
 664         rc = ntb_read_remote_spad(ndev, MW1_SZ, &val);
 665         if (rc) {
 666                 dev_err(&pdev->dev, "Error reading remote spad %d\n", MW1_SZ);
 667                 goto out;
 668         }
 669
 670         if (!val)
 671                 goto out;
 672         dev_dbg(&pdev->dev, "Remote MW1 size = %d\n", val);
 673
 674         rc = ntb_set_mw(nt, 1, val);
 675         if (rc)
 676                 goto out;
 677
 678         nt->transport_link = NTB_LINK_UP;
 679
 680         for (i = 0; i < nt->max_qps; i++) {
 681                 struct ntb_transport_qp *qp = &nt->qps[i];
 682
 683                 ntb_transport_setup_qp_mw(nt, i);
 684
 685                 if (qp->client_ready == NTB_LINK_UP)
 686                         schedule_delayed_work(&qp->link_work, 0);
 687         }
 688
 689         return;
 690
 691 out:
 692         if (ntb_hw_link_status(ndev))
 693                 schedule_delayed_work(&nt->link_work,
 694                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 695 }
 696
 697 static void ntb_qp_link_work(struct work_struct *work)
 698 {
 699         struct ntb_transport_qp *qp = container_of(work,
 700                                                    struct ntb_transport_qp,
 701                                                    link_work.work);
 702         struct pci_dev *pdev = ntb_query_pdev(qp->ndev);
 703         struct ntb_transport *nt = qp->transport;
 704         int rc, val;
 705
 706         WARN_ON(nt->transport_link != NTB_LINK_UP);
 707
 708         rc = ntb_read_local_spad(nt->ndev, QP_LINKS, &val);
 709         if (rc) {
 710                 dev_err(&pdev->dev, "Error reading spad %d\n", QP_LINKS);
 711                 return;
 712         }
 713
 714         rc = ntb_write_remote_spad(nt->ndev, QP_LINKS, val | 1 << qp->qp_num);
 715         if (rc)
 716                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
 717                         val | 1 << qp->qp_num, QP_LINKS);
 718
 719         /* query remote spad for qp ready bits */
 720         rc = ntb_read_remote_spad(nt->ndev, QP_LINKS, &val);
 721         if (rc)
 722                 dev_err(&pdev->dev, "Error reading remote spad %d\n", QP_LINKS);
 723
 724         dev_dbg(&pdev->dev, "Remote QP link status = %x\n", val);
 725
 726         /* See if the remote side is up */
 727         if (1 << qp->qp_num & val) {
 728                 qp->qp_link = NTB_LINK_UP;
 729
 730                 dev_info(&pdev->dev, "qp %d: Link Up\n", qp->qp_num);
 731                 if (qp->event_handler)
 732                         qp->event_handler(qp->cb_data, NTB_LINK_UP);
 733         } else if (nt->transport_link == NTB_LINK_UP)
 734                 schedule_delayed_work(&qp->link_work,
 735                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 736 }
 737
 738 static void ntb_transport_init_queue(struct ntb_transport *nt,
 739                                      unsigned int qp_num)
 740 {
 741         struct ntb_transport_qp *qp;
 742         unsigned int num_qps_mw, tx_size;
 743         u8 mw_num = QP_TO_MW(qp_num);
 744
 745         qp = &nt->qps[qp_num];
 746         qp->qp_num = qp_num;
 747         qp->transport = nt;
 748         qp->ndev = nt->ndev;
 749         qp->qp_link = NTB_LINK_DOWN;
 750         qp->client_ready = NTB_LINK_DOWN;
 751         qp->event_handler = NULL;
 752
 753         if (nt->max_qps % NTB_NUM_MW && mw_num < nt->max_qps % NTB_NUM_MW)
 754                 num_qps_mw = nt->max_qps / NTB_NUM_MW + 1;
 755         else
 756                 num_qps_mw = nt->max_qps / NTB_NUM_MW;
 757
 758         tx_size = ntb_get_mw_size(qp->ndev, mw_num) / num_qps_mw;
 759         qp->tx_mw_begin = ntb_get_mw_vbase(nt->ndev, mw_num) +
 760                           (qp_num / NTB_NUM_MW * tx_size);
 761         qp->tx_mw_end = qp->tx_mw_begin + tx_size;
 762         qp->tx_offset = qp->tx_mw_begin;
 763         qp->tx_max_frame = min(transport_mtu, tx_size);
 764
 765         if (nt->debugfs_dir) {
 766                 char debugfs_name[4];
 767
 768                 snprintf(debugfs_name, 4, "qp%d", qp_num);
 769                 qp->debugfs_dir = debugfs_create_dir(debugfs_name,
 770                                                      nt->debugfs_dir);
 771
 772                 qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR,
 773                                                         qp->debugfs_dir, qp,
 774                                                         &ntb_qp_debugfs_stats);
 775         }
 776
 777         INIT_DELAYED_WORK(&qp->link_work, ntb_qp_link_work);
 778         INIT_WORK(&qp->link_cleanup, ntb_qp_link_cleanup);
 779
 780         spin_lock_init(&qp->ntb_rx_pend_q_lock);
 781         spin_lock_init(&qp->ntb_rx_free_q_lock);
 782         spin_lock_init(&qp->ntb_tx_free_q_lock);
 783
 784         INIT_LIST_HEAD(&qp->rx_pend_q);
 785         INIT_LIST_HEAD(&qp->rx_free_q);
 786         INIT_LIST_HEAD(&qp->tx_free_q);
 787 }
 788
 789 int ntb_transport_init(struct pci_dev *pdev)
 790 {
 791         struct ntb_transport *nt;
 792         int rc, i;
 793
 794         nt = kzalloc(sizeof(struct ntb_transport), GFP_KERNEL);
 795         if (!nt)
 796                 return -ENOMEM;
 797
 798         if (debugfs_initialized())
 799                 nt->debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
 800         else
 801                 nt->debugfs_dir = NULL;
 802
 803         nt->ndev = ntb_register_transport(pdev, nt);
 804         if (!nt->ndev) {
 805                 rc = -EIO;
 806                 goto err;
 807         }
 808
 809         nt->max_qps = min(nt->ndev->max_cbs, max_num_clients);
 810
 811         nt->qps = kcalloc(nt->max_qps, sizeof(struct ntb_transport_qp),
 812                           GFP_KERNEL);
 813         if (!nt->qps) {
 814                 rc = -ENOMEM;
 815                 goto err1;
 816         }
 817
 818         nt->qp_bitmap = ((u64) 1 << nt->max_qps) - 1;
 819
 820         for (i = 0; i < nt->max_qps; i++)
 821                 ntb_transport_init_queue(nt, i);
 822
 823         INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work);
 824         INIT_WORK(&nt->link_cleanup, ntb_transport_link_cleanup);
 825
 826         rc = ntb_register_event_callback(nt->ndev,
 827                                          ntb_transport_event_callback);
 828         if (rc)
 829                 goto err2;
 830
 831         INIT_LIST_HEAD(&nt->client_devs);
 832         rc = ntb_bus_init(nt);
 833         if (rc)
 834                 goto err3;
 835
 836         if (ntb_hw_link_status(nt->ndev))
 837                 schedule_delayed_work(&nt->link_work, 0);
 838
 839         return 0;
 840
 841 err3:
 842         ntb_unregister_event_callback(nt->ndev);
 843 err2:
 844         kfree(nt->qps);
 845 err1:
 846         ntb_unregister_transport(nt->ndev);
 847 err:
 848         debugfs_remove_recursive(nt->debugfs_dir);
 849         kfree(nt);
 850         return rc;
 851 }
 852
 853 void ntb_transport_free(void *transport)
 854 {
 855         struct ntb_transport *nt = transport;
 856         struct pci_dev *pdev;
 857         int i;
 858
 859         nt->transport_link = NTB_LINK_DOWN;
 860
 861         /* verify that all the qp's are freed */
 862         for (i = 0; i < nt->max_qps; i++)
 863                 if (!test_bit(i, &nt->qp_bitmap))
 864                         ntb_transport_free_queue(&nt->qps[i]);
 865
 866         ntb_bus_remove(nt);
 867
 868         cancel_delayed_work_sync(&nt->link_work);
 869
 870         debugfs_remove_recursive(nt->debugfs_dir);
 871
 872         ntb_unregister_event_callback(nt->ndev);
 873
 874         pdev = ntb_query_pdev(nt->ndev);
 875
 876         for (i = 0; i < NTB_NUM_MW; i++)
 877                 if (nt->mw[i].virt_addr)
 878                         dma_free_coherent(&pdev->dev, nt->mw[i].size,
 879                                           nt->mw[i].virt_addr,
 880                                           nt->mw[i].dma_addr);
 881
 882         kfree(nt->qps);
 883         ntb_unregister_transport(nt->ndev);
 884         kfree(nt);
 885 }
 886
 887 static void ntb_rx_copy_task(struct ntb_transport_qp *qp,
 888                              struct ntb_queue_entry *entry, void *offset)
 889 {
 890
 891         struct ntb_payload_header *hdr;
 892
 893         BUG_ON(offset < qp->rx_buff_begin ||
 894                offset + qp->rx_max_frame >= qp->rx_buff_end);
 895
 896         hdr = offset + qp->rx_max_frame - sizeof(struct ntb_payload_header);
 897         entry->len = hdr->len;
 898
 899         memcpy(entry->buf, offset, entry->len);
 900
 901         /* Ensure that the data is fully copied out before clearing the flag */
 902         wmb();
 903         hdr->flags = 0;
 904
 905         if (qp->rx_handler && qp->client_ready == NTB_LINK_UP)
 906                 qp->rx_handler(qp, qp->cb_data, entry->cb_data, entry->len);
 907
 908         ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry, &qp->rx_free_q);
 909 }
 910
 911 static int ntb_process_rxc(struct ntb_transport_qp *qp)
 912 {
 913         struct ntb_payload_header *hdr;
 914         struct ntb_queue_entry *entry;
 915         void *offset;
 916
 917         entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q);
 918         if (!entry) {
 919                 hdr = offset + qp->rx_max_frame -
 920                       sizeof(struct ntb_payload_header);
 921                 dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
 922                         "no buffer - HDR ver %llu, len %d, flags %x\n",
 923                         hdr->ver, hdr->len, hdr->flags);
 924                 qp->rx_err_no_buf++;
 925                 return -ENOMEM;
 926         }
 927
 928         offset = qp->rx_offset;
 929         hdr = offset + qp->rx_max_frame - sizeof(struct ntb_payload_header);
 930
 931         if (!(hdr->flags & DESC_DONE_FLAG)) {
 932                 ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
 933                                   &qp->rx_pend_q);
 934                 qp->rx_ring_empty++;
 935                 return -EAGAIN;
 936         }
 937
 938         if (hdr->ver != qp->rx_pkts) {
 939                 dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
 940                         "qp %d: version mismatch, expected %llu - got %llu\n",
 941                         qp->qp_num, qp->rx_pkts, hdr->ver);
 942                 ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
 943                                   &qp->rx_pend_q);
 944                 qp->rx_err_ver++;
 945                 return -EIO;
 946         }
 947
 948         if (hdr->flags & LINK_DOWN_FLAG) {
 949                 ntb_qp_link_down(qp);
 950
 951                 ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
 952                                   &qp->rx_pend_q);
 953
 954                 /* Ensure that the data is fully copied out before clearing the
 955                  * done flag
 956                  */
 957                 wmb();
 958                 hdr->flags = 0;
 959                 goto out;
 960         }
 961
 962         dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
 963                 "rx offset %p, ver %llu - %d payload received, buf size %d\n",
 964                 qp->rx_offset, hdr->ver, hdr->len, entry->len);
 965
 966         if (hdr->len <= entry->len)
 967                 ntb_rx_copy_task(qp, entry, offset);
 968         else {
 969                 ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
 970                                   &qp->rx_pend_q);
 971
 972                 /* Ensure that the data is fully copied out before clearing the
 973                  * done flag
 974                  */
 975                 wmb();
 976                 hdr->flags = 0;
 977                 qp->rx_err_oflow++;
 978                 dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
 979                         "RX overflow! Wanted %d got %d\n",
 980                         hdr->len, entry->len);
 981         }
 982
 983         qp->rx_bytes += hdr->len;
 984         qp->rx_pkts++;
 985
 986 out:
 987         qp->rx_offset += qp->rx_max_frame;
 988         if (qp->rx_offset + qp->rx_max_frame >= qp->rx_buff_end)
 989                 qp->rx_offset = qp->rx_buff_begin;
 990
 991         return 0;
 992 }
 993
 994 static void ntb_transport_rx(unsigned long data)
 995 {
 996         struct ntb_transport_qp *qp = (struct ntb_transport_qp *)data;
 997         int rc;
 998
 999         do {
1000                 rc = ntb_process_rxc(qp);
1001         } while (!rc);
1002 }
1003
1004 static void ntb_transport_rxc_db(void *data, int db_num)
1005 {
1006         struct ntb_transport_qp *qp = data;
1007
1008         dev_dbg(&ntb_query_pdev(qp->ndev)->dev, "%s: doorbell %d received\n",
1009                 __func__, db_num);
1010
1011         tasklet_schedule(&qp->rx_work);
1012 }
1013
1014 static void ntb_tx_copy_task(struct ntb_transport_qp *qp,
1015                              struct ntb_queue_entry *entry,
1016                              void *offset)
1017 {
1018         struct ntb_payload_header *hdr;
1019
1020         BUG_ON(offset < qp->tx_mw_begin ||
1021                offset + qp->tx_max_frame >= qp->tx_mw_end);
1022
1023         memcpy_toio(offset, entry->buf, entry->len);
1024
1025         hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
1026         hdr->len = entry->len;
1027         hdr->ver = qp->tx_pkts;
1028
1029         /* Ensure that the data is fully copied out before setting the flag */
1030         wmb();
1031         hdr->flags = entry->flags | DESC_DONE_FLAG;
1032
1033         ntb_ring_sdb(qp->ndev, qp->qp_num);
1034
1035         /* The entry length can only be zero if the packet is intended to be a
1036          * "link down" or similar.  Since no payload is being sent in these
1037          * cases, there is nothing to add to the completion queue.
1038          */
1039         if (entry->len > 0) {
1040                 qp->tx_bytes += entry->len;
1041
1042                 if (qp->tx_handler)
1043                         qp->tx_handler(qp, qp->cb_data, entry->cb_data,
1044                                        entry->len);
1045         }
1046
1047         ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q);
1048 }
1049
1050 static int ntb_process_tx(struct ntb_transport_qp *qp,
1051                           struct ntb_queue_entry *entry)
1052 {
1053         struct ntb_payload_header *hdr;
1054         void *offset;
1055
1056         offset = qp->tx_offset;
1057         hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
1058
1059         dev_dbg(&ntb_query_pdev(qp->ndev)->dev, "%lld - offset %p, tx %p, entry len %d flags %x buff %p\n",
1060                  qp->tx_pkts, offset, qp->tx_offset, entry->len, entry->flags,
1061                  entry->buf);
1062         if (hdr->flags) {
1063                 qp->tx_ring_full++;
1064                 return -EAGAIN;
1065         }
1066
1067         if (entry->len > qp->tx_max_frame - sizeof(struct ntb_payload_header)) {
1068                 if (qp->tx_handler)
1069                         qp->tx_handler(qp->cb_data, qp, NULL, -EIO);
1070
1071                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1072                              &qp->tx_free_q);
1073                 return 0;
1074         }
1075
1076         ntb_tx_copy_task(qp, entry, offset);
1077
1078         qp->tx_offset += qp->tx_max_frame;
1079         if (qp->tx_offset + qp->tx_max_frame >= qp->tx_mw_end)
1080                 qp->tx_offset = qp->tx_mw_begin;
1081
1082         qp->tx_pkts++;
1083
1084         return 0;
1085 }
1086
1087 static void ntb_send_link_down(struct ntb_transport_qp *qp)
1088 {
1089         struct pci_dev *pdev = ntb_query_pdev(qp->ndev);
1090         struct ntb_queue_entry *entry;
1091         int i, rc;
1092
1093         if (qp->qp_link == NTB_LINK_DOWN)
1094                 return;
1095
1096         qp->qp_link = NTB_LINK_DOWN;
1097         dev_info(&pdev->dev, "qp %d: Link Down\n", qp->qp_num);
1098
1099         for (i = 0; i < NTB_LINK_DOWN_TIMEOUT; i++) {
1100                 entry = ntb_list_rm(&qp->ntb_tx_free_q_lock,
1101                                          &qp->tx_free_q);
1102                 if (entry)
1103                         break;
1104                 msleep(100);
1105         }
1106
1107         if (!entry)
1108                 return;
1109
1110         entry->cb_data = NULL;
1111         entry->buf = NULL;
1112         entry->len = 0;
1113         entry->flags = LINK_DOWN_FLAG;
1114
1115         rc = ntb_process_tx(qp, entry);
1116         if (rc)
1117                 dev_err(&pdev->dev, "ntb: QP%d unable to send linkdown msg\n",
1118                         qp->qp_num);
1119 }
1120
1121 /**
1122  * ntb_transport_create_queue - Create a new NTB transport layer queue
1123  * @rx_handler: receive callback function
1124  * @tx_handler: transmit callback function
1125  * @event_handler: event callback function
1126  *
1127  * Create a new NTB transport layer queue and provide the queue with a callback
1128  * routine for both transmit and receive.  The receive callback routine will be
1129  * used to pass up data when the transport has received it on the queue.   The
1130  * transmit callback routine will be called when the transport has completed the
1131  * transmission of the data on the queue and the data is ready to be freed.
1132  *
1133  * RETURNS: pointer to newly created ntb_queue, NULL on error.
1134  */
1135 struct ntb_transport_qp *
1136 ntb_transport_create_queue(void *data, struct pci_dev *pdev,
1137                            const struct ntb_queue_handlers *handlers)
1138 {
1139         struct ntb_queue_entry *entry;
1140         struct ntb_transport_qp *qp;
1141         struct ntb_transport *nt;
1142         unsigned int free_queue;
1143         int rc, i;
1144
1145         nt = ntb_find_transport(pdev);
1146         if (!nt)
1147                 goto err;
1148
1149         free_queue = ffs(nt->qp_bitmap);
1150         if (!free_queue)
1151                 goto err;
1152
1153         /* decrement free_queue to make it zero based */
1154         free_queue--;
1155
1156         clear_bit(free_queue, &nt->qp_bitmap);
1157
1158         qp = &nt->qps[free_queue];
1159         qp->cb_data = data;
1160         qp->rx_handler = handlers->rx_handler;
1161         qp->tx_handler = handlers->tx_handler;
1162         qp->event_handler = handlers->event_handler;
1163
1164         for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
1165                 entry = kzalloc(sizeof(struct ntb_queue_entry), GFP_ATOMIC);
1166                 if (!entry)
1167                         goto err1;
1168
1169                 ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry,
1170                                   &qp->rx_free_q);
1171         }
1172
1173         for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
1174                 entry = kzalloc(sizeof(struct ntb_queue_entry), GFP_ATOMIC);
1175                 if (!entry)
1176                         goto err2;
1177
1178                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1179                                   &qp->tx_free_q);
1180         }
1181
1182         tasklet_init(&qp->rx_work, ntb_transport_rx, (unsigned long) qp);
1183
1184         rc = ntb_register_db_callback(qp->ndev, free_queue, qp,
1185                                       ntb_transport_rxc_db);
1186         if (rc)
1187                 goto err3;
1188
1189         dev_info(&pdev->dev, "NTB Transport QP %d created\n", qp->qp_num);
1190
1191         return qp;
1192
1193 err3:
1194         tasklet_disable(&qp->rx_work);
1195 err2:
1196         while ((entry =
1197                 ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1198                 kfree(entry);
1199 err1:
1200         while ((entry =
1201                 ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q)))
1202                 kfree(entry);
1203         set_bit(free_queue, &nt->qp_bitmap);
1204 err:
1205         return NULL;
1206 }
1207 EXPORT_SYMBOL_GPL(ntb_transport_create_queue);
1208
1209 /**
1210  * ntb_transport_free_queue - Frees NTB transport queue
1211  * @qp: NTB queue to be freed
1212  *
1213  * Frees NTB transport queue
1214  */
1215 void ntb_transport_free_queue(struct ntb_transport_qp *qp)
1216 {
1217         struct pci_dev *pdev = ntb_query_pdev(qp->ndev);
1218         struct ntb_queue_entry *entry;
1219
1220         if (!qp)
1221                 return;
1222
1223         cancel_delayed_work_sync(&qp->link_work);
1224
1225         ntb_unregister_db_callback(qp->ndev, qp->qp_num);
1226         tasklet_disable(&qp->rx_work);
1227
1228         while ((entry =
1229                 ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q)))
1230                 kfree(entry);
1231
1232         while ((entry =
1233                 ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q))) {
1234                 dev_warn(&pdev->dev, "Freeing item from a non-empty queue\n");
1235                 kfree(entry);
1236         }
1237
1238         while ((entry =
1239                 ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1240                 kfree(entry);
1241
1242         set_bit(qp->qp_num, &qp->transport->qp_bitmap);
1243
1244         dev_info(&pdev->dev, "NTB Transport QP %d freed\n", qp->qp_num);
1245 }
1246 EXPORT_SYMBOL_GPL(ntb_transport_free_queue);
1247
1248 /**
1249  * ntb_transport_rx_remove - Dequeues enqueued rx packet
1250  * @qp: NTB queue to be freed
1251  * @len: pointer to variable to write enqueued buffers length
1252  *
1253  * Dequeues unused buffers from receive queue.  Should only be used during
1254  * shutdown of qp.
1255  *
1256  * RETURNS: NULL error value on error, or void* for success.
1257  */
1258 void *ntb_transport_rx_remove(struct ntb_transport_qp *qp, unsigned int *len)
1259 {
1260         struct ntb_queue_entry *entry;
1261         void *buf;
1262
1263         if (!qp || qp->client_ready == NTB_LINK_UP)
1264                 return NULL;
1265
1266         entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q);
1267         if (!entry)
1268                 return NULL;
1269
1270         buf = entry->cb_data;
1271         *len = entry->len;
1272
1273         ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry,
1274                           &qp->rx_free_q);
1275
1276         return buf;
1277 }
1278 EXPORT_SYMBOL_GPL(ntb_transport_rx_remove);
1279
1280 /**
1281  * ntb_transport_rx_enqueue - Enqueue a new NTB queue entry
1282  * @qp: NTB transport layer queue the entry is to be enqueued on
1283  * @cb: per buffer pointer for callback function to use
1284  * @data: pointer to data buffer that incoming packets will be copied into
1285  * @len: length of the data buffer
1286  *
1287  * Enqueue a new receive buffer onto the transport queue into which a NTB
1288  * payload can be received into.
1289  *
1290  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
1291  */
1292 int ntb_transport_rx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
1293                              unsigned int len)
1294 {
1295         struct ntb_queue_entry *entry;
1296
1297         if (!qp)
1298                 return -EINVAL;
1299
1300         entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q);
1301         if (!entry)
1302                 return -ENOMEM;
1303
1304         entry->cb_data = cb;
1305         entry->buf = data;
1306         entry->len = len;
1307
1308         ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
1309                           &qp->rx_pend_q);
1310
1311         return 0;
1312 }
1313 EXPORT_SYMBOL_GPL(ntb_transport_rx_enqueue);
1314
1315 /**
1316  * ntb_transport_tx_enqueue - Enqueue a new NTB queue entry
1317  * @qp: NTB transport layer queue the entry is to be enqueued on
1318  * @cb: per buffer pointer for callback function to use
1319  * @data: pointer to data buffer that will be sent
1320  * @len: length of the data buffer
1321  *
1322  * Enqueue a new transmit buffer onto the transport queue from which a NTB
1323  * payload will be transmitted.  This assumes that a lock is behing held to
1324  * serialize access to the qp.
1325  *
1326  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
1327  */
1328 int ntb_transport_tx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
1329                              unsigned int len)
1330 {
1331         struct ntb_queue_entry *entry;
1332         int rc;
1333
1334         if (!qp || qp->qp_link != NTB_LINK_UP || !len)
1335                 return -EINVAL;
1336
1337         entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1338         if (!entry)
1339                 return -ENOMEM;
1340
1341         entry->cb_data = cb;
1342         entry->buf = data;
1343         entry->len = len;
1344         entry->flags = 0;
1345
1346         rc = ntb_process_tx(qp, entry);
1347         if (rc)
1348                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1349                              &qp->tx_free_q);
1350
1351         return rc;
1352 }
1353 EXPORT_SYMBOL_GPL(ntb_transport_tx_enqueue);
1354
1355 /**
1356  * ntb_transport_link_up - Notify NTB transport of client readiness to use queue
1357  * @qp: NTB transport layer queue to be enabled
1358  *
1359  * Notify NTB transport layer of client readiness to use queue
1360  */
1361 void ntb_transport_link_up(struct ntb_transport_qp *qp)
1362 {
1363         if (!qp)
1364                 return;
1365
1366         qp->client_ready = NTB_LINK_UP;
1367
1368         if (qp->transport->transport_link == NTB_LINK_UP)
1369                 schedule_delayed_work(&qp->link_work, 0);
1370 }
1371 EXPORT_SYMBOL_GPL(ntb_transport_link_up);
1372
1373 /**
1374  * ntb_transport_link_down - Notify NTB transport to no longer enqueue data
1375  * @qp: NTB transport layer queue to be disabled
1376  *
1377  * Notify NTB transport layer of client's desire to no longer receive data on
1378  * transport queue specified.  It is the client's responsibility to ensure all
1379  * entries on queue are purged or otherwise handled appropraitely.
1380  */
1381 void ntb_transport_link_down(struct ntb_transport_qp *qp)
1382 {
1383         struct pci_dev *pdev = ntb_query_pdev(qp->ndev);
1384         int rc, val;
1385
1386         if (!qp)
1387                 return;
1388
1389         qp->client_ready = NTB_LINK_DOWN;
1390
1391         rc = ntb_read_local_spad(qp->ndev, QP_LINKS, &val);
1392         if (rc) {
1393                 dev_err(&pdev->dev, "Error reading spad %d\n", QP_LINKS);
1394                 return;
1395         }
1396
1397         rc = ntb_write_remote_spad(qp->ndev, QP_LINKS,
1398                                    val & ~(1 << qp->qp_num));
1399         if (rc)
1400                 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
1401                         val & ~(1 << qp->qp_num), QP_LINKS);
1402
1403         if (qp->qp_link == NTB_LINK_UP)
1404                 ntb_send_link_down(qp);
1405         else
1406                 cancel_delayed_work_sync(&qp->link_work);
1407 }
1408 EXPORT_SYMBOL_GPL(ntb_transport_link_down);
1409
1410 /**
1411  * ntb_transport_link_query - Query transport link state
1412  * @qp: NTB transport layer queue to be queried
1413  *
1414  * Query connectivity to the remote system of the NTB transport queue
1415  *
1416  * RETURNS: true for link up or false for link down
1417  */
1418 bool ntb_transport_link_query(struct ntb_transport_qp *qp)
1419 {
1420         return qp->qp_link == NTB_LINK_UP;
1421 }
1422 EXPORT_SYMBOL_GPL(ntb_transport_link_query);
1423
1424 /**
1425  * ntb_transport_qp_num - Query the qp number
1426  * @qp: NTB transport layer queue to be queried
1427  *
1428  * Query qp number of the NTB transport queue
1429  *
1430  * RETURNS: a zero based number specifying the qp number
1431  */
1432 unsigned char ntb_transport_qp_num(struct ntb_transport_qp *qp)
1433 {
1434         return qp->qp_num;
1435 }
1436 EXPORT_SYMBOL_GPL(ntb_transport_qp_num);
1437
1438 /**
1439  * ntb_transport_max_size - Query the max payload size of a qp
1440  * @qp: NTB transport layer queue to be queried
1441  *
1442  * Query the maximum payload size permissible on the given qp
1443  *
1444  * RETURNS: the max payload size of a qp
1445  */
1446 unsigned int ntb_transport_max_size(struct ntb_transport_qp *qp)
1447 {
1448         return qp->tx_max_frame - sizeof(struct ntb_payload_header);
1449 }
1450 EXPORT_SYMBOL_GPL(ntb_transport_max_size);