linux/drivers/ntb/ntb_transport.c
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   1/*
   2 * This file is provided under a dual BSD/GPLv2 license.  When using or
   3 *   redistributing this file, you may do so under either license.
   4 *
   5 *   GPL LICENSE SUMMARY
   6 *
   7 *   Copyright(c) 2012 Intel Corporation. All rights reserved.
   8 *
   9 *   This program is free software; you can redistribute it and/or modify
  10 *   it under the terms of version 2 of the GNU General Public License as
  11 *   published by the Free Software Foundation.
  12 *
  13 *   BSD LICENSE
  14 *
  15 *   Copyright(c) 2012 Intel Corporation. All rights reserved.
  16 *
  17 *   Redistribution and use in source and binary forms, with or without
  18 *   modification, are permitted provided that the following conditions
  19 *   are met:
  20 *
  21 *     * Redistributions of source code must retain the above copyright
  22 *       notice, this list of conditions and the following disclaimer.
  23 *     * Redistributions in binary form must reproduce the above copy
  24 *       notice, this list of conditions and the following disclaimer in
  25 *       the documentation and/or other materials provided with the
  26 *       distribution.
  27 *     * Neither the name of Intel Corporation nor the names of its
  28 *       contributors may be used to endorse or promote products derived
  29 *       from this software without specific prior written permission.
  30 *
  31 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  32 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  33 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  34 *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  35 *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  36 *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  37 *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  38 *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  39 *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  40 *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  41 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  42 *
  43 * Intel PCIe NTB Linux driver
  44 *
  45 * Contact Information:
  46 * Jon Mason <jon.mason@intel.com>
  47 */
  48#include <linux/debugfs.h>
  49#include <linux/delay.h>
  50#include <linux/dma-mapping.h>
  51#include <linux/errno.h>
  52#include <linux/export.h>
  53#include <linux/interrupt.h>
  54#include <linux/module.h>
  55#include <linux/pci.h>
  56#include <linux/slab.h>
  57#include <linux/types.h>
  58#include <linux/ntb.h>
  59#include "ntb_hw.h"
  60
  61#define NTB_TRANSPORT_VERSION   3
  62
  63static unsigned int transport_mtu = 0x401E;
  64module_param(transport_mtu, uint, 0644);
  65MODULE_PARM_DESC(transport_mtu, "Maximum size of NTB transport packets");
  66
  67static unsigned char max_num_clients = 2;
  68module_param(max_num_clients, byte, 0644);
  69MODULE_PARM_DESC(max_num_clients, "Maximum number of NTB transport clients");
  70
  71struct 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
  81struct ntb_rx_info {
  82        unsigned int entry;
  83};
  84
  85struct ntb_transport_qp {
  86        struct ntb_transport *transport;
  87        struct ntb_device *ndev;
  88        void *cb_data;
  89
  90        bool client_ready;
  91        bool qp_link;
  92        u8 qp_num;      /* Only 64 QP's are allowed.  0-63 */
  93
  94        struct ntb_rx_info __iomem *rx_info;
  95        struct ntb_rx_info *remote_rx_info;
  96
  97        void (*tx_handler) (struct ntb_transport_qp *qp, void *qp_data,
  98                            void *data, int len);
  99        struct list_head tx_free_q;
 100        spinlock_t ntb_tx_free_q_lock;
 101        void __iomem *tx_mw;
 102        unsigned int tx_index;
 103        unsigned int tx_max_entry;
 104        unsigned int tx_max_frame;
 105
 106        void (*rx_handler) (struct ntb_transport_qp *qp, void *qp_data,
 107                            void *data, int len);
 108        struct tasklet_struct rx_work;
 109        struct list_head rx_pend_q;
 110        struct list_head rx_free_q;
 111        spinlock_t ntb_rx_pend_q_lock;
 112        spinlock_t ntb_rx_free_q_lock;
 113        void *rx_buff;
 114        unsigned int rx_index;
 115        unsigned int rx_max_entry;
 116        unsigned int rx_max_frame;
 117
 118        void (*event_handler) (void *data, int status);
 119        struct delayed_work link_work;
 120        struct work_struct link_cleanup;
 121
 122        struct dentry *debugfs_dir;
 123        struct dentry *debugfs_stats;
 124
 125        /* Stats */
 126        u64 rx_bytes;
 127        u64 rx_pkts;
 128        u64 rx_ring_empty;
 129        u64 rx_err_no_buf;
 130        u64 rx_err_oflow;
 131        u64 rx_err_ver;
 132        u64 tx_bytes;
 133        u64 tx_pkts;
 134        u64 tx_ring_full;
 135};
 136
 137struct ntb_transport_mw {
 138        size_t size;
 139        void *virt_addr;
 140        dma_addr_t dma_addr;
 141};
 142
 143struct ntb_transport_client_dev {
 144        struct list_head entry;
 145        struct device dev;
 146};
 147
 148struct ntb_transport {
 149        struct list_head entry;
 150        struct list_head client_devs;
 151
 152        struct ntb_device *ndev;
 153        struct ntb_transport_mw mw[NTB_NUM_MW];
 154        struct ntb_transport_qp *qps;
 155        unsigned int max_qps;
 156        unsigned long qp_bitmap;
 157        bool transport_link;
 158        struct delayed_work link_work;
 159        struct work_struct link_cleanup;
 160        struct dentry *debugfs_dir;
 161};
 162
 163enum {
 164        DESC_DONE_FLAG = 1 << 0,
 165        LINK_DOWN_FLAG = 1 << 1,
 166};
 167
 168struct ntb_payload_header {
 169        unsigned int ver;
 170        unsigned int len;
 171        unsigned int flags;
 172};
 173
 174enum {
 175        VERSION = 0,
 176        QP_LINKS,
 177        NUM_QPS,
 178        NUM_MWS,
 179        MW0_SZ_HIGH,
 180        MW0_SZ_LOW,
 181        MW1_SZ_HIGH,
 182        MW1_SZ_LOW,
 183        MAX_SPAD,
 184};
 185
 186#define QP_TO_MW(qp)            ((qp) % NTB_NUM_MW)
 187#define NTB_QP_DEF_NUM_ENTRIES  100
 188#define NTB_LINK_DOWN_TIMEOUT   10
 189
 190static int ntb_match_bus(struct device *dev, struct device_driver *drv)
 191{
 192        return !strncmp(dev_name(dev), drv->name, strlen(drv->name));
 193}
 194
 195static int ntb_client_probe(struct device *dev)
 196{
 197        const struct ntb_client *drv = container_of(dev->driver,
 198                                                    struct ntb_client, driver);
 199        struct pci_dev *pdev = container_of(dev->parent, struct pci_dev, dev);
 200        int rc = -EINVAL;
 201
 202        get_device(dev);
 203        if (drv && drv->probe)
 204                rc = drv->probe(pdev);
 205        if (rc)
 206                put_device(dev);
 207
 208        return rc;
 209}
 210
 211static int ntb_client_remove(struct device *dev)
 212{
 213        const struct ntb_client *drv = container_of(dev->driver,
 214                                                    struct ntb_client, driver);
 215        struct pci_dev *pdev = container_of(dev->parent, struct pci_dev, dev);
 216
 217        if (drv && drv->remove)
 218                drv->remove(pdev);
 219
 220        put_device(dev);
 221
 222        return 0;
 223}
 224
 225static struct bus_type ntb_bus_type = {
 226        .name = "ntb_bus",
 227        .match = ntb_match_bus,
 228        .probe = ntb_client_probe,
 229        .remove = ntb_client_remove,
 230};
 231
 232static LIST_HEAD(ntb_transport_list);
 233
 234static int ntb_bus_init(struct ntb_transport *nt)
 235{
 236        if (list_empty(&ntb_transport_list)) {
 237                int rc = bus_register(&ntb_bus_type);
 238                if (rc)
 239                        return rc;
 240        }
 241
 242        list_add(&nt->entry, &ntb_transport_list);
 243
 244        return 0;
 245}
 246
 247static void ntb_bus_remove(struct ntb_transport *nt)
 248{
 249        struct ntb_transport_client_dev *client_dev, *cd;
 250
 251        list_for_each_entry_safe(client_dev, cd, &nt->client_devs, entry) {
 252                dev_err(client_dev->dev.parent, "%s still attached to bus, removing\n",
 253                        dev_name(&client_dev->dev));
 254                list_del(&client_dev->entry);
 255                device_unregister(&client_dev->dev);
 256        }
 257
 258        list_del(&nt->entry);
 259
 260        if (list_empty(&ntb_transport_list))
 261                bus_unregister(&ntb_bus_type);
 262}
 263
 264static void ntb_client_release(struct device *dev)
 265{
 266        struct ntb_transport_client_dev *client_dev;
 267        client_dev = container_of(dev, struct ntb_transport_client_dev, dev);
 268
 269        kfree(client_dev);
 270}
 271
 272/**
 273 * ntb_unregister_client_dev - Unregister NTB client device
 274 * @device_name: Name of NTB client device
 275 *
 276 * Unregister an NTB client device with the NTB transport layer
 277 */
 278void ntb_unregister_client_dev(char *device_name)
 279{
 280        struct ntb_transport_client_dev *client, *cd;
 281        struct ntb_transport *nt;
 282
 283        list_for_each_entry(nt, &ntb_transport_list, entry)
 284                list_for_each_entry_safe(client, cd, &nt->client_devs, entry)
 285                        if (!strncmp(dev_name(&client->dev), device_name,
 286                                     strlen(device_name))) {
 287                                list_del(&client->entry);
 288                                device_unregister(&client->dev);
 289                        }
 290}
 291EXPORT_SYMBOL_GPL(ntb_unregister_client_dev);
 292
 293/**
 294 * ntb_register_client_dev - Register NTB client device
 295 * @device_name: Name of NTB client device
 296 *
 297 * Register an NTB client device with the NTB transport layer
 298 */
 299int ntb_register_client_dev(char *device_name)
 300{
 301        struct ntb_transport_client_dev *client_dev;
 302        struct ntb_transport *nt;
 303        int rc, i = 0;
 304
 305        if (list_empty(&ntb_transport_list))
 306                return -ENODEV;
 307
 308        list_for_each_entry(nt, &ntb_transport_list, entry) {
 309                struct device *dev;
 310
 311                client_dev = kzalloc(sizeof(struct ntb_transport_client_dev),
 312                                     GFP_KERNEL);
 313                if (!client_dev) {
 314                        rc = -ENOMEM;
 315                        goto err;
 316                }
 317
 318                dev = &client_dev->dev;
 319
 320                /* setup and register client devices */
 321                dev_set_name(dev, "%s%d", device_name, i);
 322                dev->bus = &ntb_bus_type;
 323                dev->release = ntb_client_release;
 324                dev->parent = &ntb_query_pdev(nt->ndev)->dev;
 325
 326                rc = device_register(dev);
 327                if (rc) {
 328                        kfree(client_dev);
 329                        goto err;
 330                }
 331
 332                list_add_tail(&client_dev->entry, &nt->client_devs);
 333                i++;
 334        }
 335
 336        return 0;
 337
 338err:
 339        ntb_unregister_client_dev(device_name);
 340
 341        return rc;
 342}
 343EXPORT_SYMBOL_GPL(ntb_register_client_dev);
 344
 345/**
 346 * ntb_register_client - Register NTB client driver
 347 * @drv: NTB client driver to be registered
 348 *
 349 * Register an NTB client driver with the NTB transport layer
 350 *
 351 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 352 */
 353int ntb_register_client(struct ntb_client *drv)
 354{
 355        drv->driver.bus = &ntb_bus_type;
 356
 357        if (list_empty(&ntb_transport_list))
 358                return -ENODEV;
 359
 360        return driver_register(&drv->driver);
 361}
 362EXPORT_SYMBOL_GPL(ntb_register_client);
 363
 364/**
 365 * ntb_unregister_client - Unregister NTB client driver
 366 * @drv: NTB client driver to be unregistered
 367 *
 368 * Unregister an NTB client driver with the NTB transport layer
 369 *
 370 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 371 */
 372void ntb_unregister_client(struct ntb_client *drv)
 373{
 374        driver_unregister(&drv->driver);
 375}
 376EXPORT_SYMBOL_GPL(ntb_unregister_client);
 377
 378static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count,
 379                            loff_t *offp)
 380{
 381        struct ntb_transport_qp *qp;
 382        char *buf;
 383        ssize_t ret, out_offset, out_count;
 384
 385        out_count = 600;
 386
 387        buf = kmalloc(out_count, GFP_KERNEL);
 388        if (!buf)
 389                return -ENOMEM;
 390
 391        qp = filp->private_data;
 392        out_offset = 0;
 393        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 394                               "NTB QP stats\n");
 395        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 396                               "rx_bytes - \t%llu\n", qp->rx_bytes);
 397        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 398                               "rx_pkts - \t%llu\n", qp->rx_pkts);
 399        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 400                               "rx_ring_empty - %llu\n", qp->rx_ring_empty);
 401        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 402                               "rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
 403        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 404                               "rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
 405        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 406                               "rx_err_ver - \t%llu\n", qp->rx_err_ver);
 407        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 408                               "rx_buff - \t%p\n", qp->rx_buff);
 409        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 410                               "rx_index - \t%u\n", qp->rx_index);
 411        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 412                               "rx_max_entry - \t%u\n", qp->rx_max_entry);
 413
 414        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 415                               "tx_bytes - \t%llu\n", qp->tx_bytes);
 416        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 417                               "tx_pkts - \t%llu\n", qp->tx_pkts);
 418        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 419                               "tx_ring_full - \t%llu\n", qp->tx_ring_full);
 420        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 421                               "tx_mw - \t%p\n", qp->tx_mw);
 422        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 423                               "tx_index - \t%u\n", qp->tx_index);
 424        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 425                               "tx_max_entry - \t%u\n", qp->tx_max_entry);
 426
 427        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 428                               "\nQP Link %s\n", (qp->qp_link == NTB_LINK_UP) ?
 429                               "Up" : "Down");
 430        if (out_offset > out_count)
 431                out_offset = out_count;
 432
 433        ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
 434        kfree(buf);
 435        return ret;
 436}
 437
 438static const struct file_operations ntb_qp_debugfs_stats = {
 439        .owner = THIS_MODULE,
 440        .open = simple_open,
 441        .read = debugfs_read,
 442};
 443
 444static void ntb_list_add(spinlock_t *lock, struct list_head *entry,
 445                         struct list_head *list)
 446{
 447        unsigned long flags;
 448
 449        spin_lock_irqsave(lock, flags);
 450        list_add_tail(entry, list);
 451        spin_unlock_irqrestore(lock, flags);
 452}
 453
 454static struct ntb_queue_entry *ntb_list_rm(spinlock_t *lock,
 455                                                struct list_head *list)
 456{
 457        struct ntb_queue_entry *entry;
 458        unsigned long flags;
 459
 460        spin_lock_irqsave(lock, flags);
 461        if (list_empty(list)) {
 462                entry = NULL;
 463                goto out;
 464        }
 465        entry = list_first_entry(list, struct ntb_queue_entry, entry);
 466        list_del(&entry->entry);
 467out:
 468        spin_unlock_irqrestore(lock, flags);
 469
 470        return entry;
 471}
 472
 473static void ntb_transport_setup_qp_mw(struct ntb_transport *nt,
 474                                      unsigned int qp_num)
 475{
 476        struct ntb_transport_qp *qp = &nt->qps[qp_num];
 477        unsigned int rx_size, num_qps_mw;
 478        u8 mw_num = QP_TO_MW(qp_num);
 479        unsigned int i;
 480
 481        WARN_ON(nt->mw[mw_num].virt_addr == NULL);
 482
 483        if (nt->max_qps % NTB_NUM_MW && mw_num < nt->max_qps % NTB_NUM_MW)
 484                num_qps_mw = nt->max_qps / NTB_NUM_MW + 1;
 485        else
 486                num_qps_mw = nt->max_qps / NTB_NUM_MW;
 487
 488        rx_size = (unsigned int) nt->mw[mw_num].size / num_qps_mw;
 489        qp->remote_rx_info = nt->mw[mw_num].virt_addr +
 490                             (qp_num / NTB_NUM_MW * rx_size);
 491        rx_size -= sizeof(struct ntb_rx_info);
 492
 493        qp->rx_buff = qp->remote_rx_info + 1;
 494        /* Due to housekeeping, there must be atleast 2 buffs */
 495        qp->rx_max_frame = min(transport_mtu, rx_size / 2);
 496        qp->rx_max_entry = rx_size / qp->rx_max_frame;
 497        qp->rx_index = 0;
 498
 499        qp->remote_rx_info->entry = qp->rx_max_entry - 1;
 500
 501        /* setup the hdr offsets with 0's */
 502        for (i = 0; i < qp->rx_max_entry; i++) {
 503                void *offset = qp->rx_buff + qp->rx_max_frame * (i + 1) -
 504                               sizeof(struct ntb_payload_header);
 505                memset(offset, 0, sizeof(struct ntb_payload_header));
 506        }
 507
 508        qp->rx_pkts = 0;
 509        qp->tx_pkts = 0;
 510        qp->tx_index = 0;
 511}
 512
 513static void ntb_free_mw(struct ntb_transport *nt, int num_mw)
 514{
 515        struct ntb_transport_mw *mw = &nt->mw[num_mw];
 516        struct pci_dev *pdev = ntb_query_pdev(nt->ndev);
 517
 518        if (!mw->virt_addr)
 519                return;
 520
 521        dma_free_coherent(&pdev->dev, mw->size, mw->virt_addr, mw->dma_addr);
 522        mw->virt_addr = NULL;
 523}
 524
 525static int ntb_set_mw(struct ntb_transport *nt, int num_mw, unsigned int size)
 526{
 527        struct ntb_transport_mw *mw = &nt->mw[num_mw];
 528        struct pci_dev *pdev = ntb_query_pdev(nt->ndev);
 529
 530        /* No need to re-setup */
 531        if (mw->size == ALIGN(size, 4096))
 532                return 0;
 533
 534        if (mw->size != 0)
 535                ntb_free_mw(nt, num_mw);
 536
 537        /* Alloc memory for receiving data.  Must be 4k aligned */
 538        mw->size = ALIGN(size, 4096);
 539
 540        mw->virt_addr = dma_alloc_coherent(&pdev->dev, mw->size, &mw->dma_addr,
 541                                           GFP_KERNEL);
 542        if (!mw->virt_addr) {
 543                mw->size = 0;
 544                dev_err(&pdev->dev, "Unable to allocate MW buffer of size %d\n",
 545                       (int) mw->size);
 546                return -ENOMEM;
 547        }
 548
 549        /* Notify HW the memory location of the receive buffer */
 550        ntb_set_mw_addr(nt->ndev, num_mw, mw->dma_addr);
 551
 552        return 0;
 553}
 554
 555static void ntb_qp_link_cleanup(struct work_struct *work)
 556{
 557        struct ntb_transport_qp *qp = container_of(work,
 558                                                   struct ntb_transport_qp,
 559                                                   link_cleanup);
 560        struct ntb_transport *nt = qp->transport;
 561        struct pci_dev *pdev = ntb_query_pdev(nt->ndev);
 562
 563        if (qp->qp_link == NTB_LINK_DOWN) {
 564                cancel_delayed_work_sync(&qp->link_work);
 565                return;
 566        }
 567
 568        if (qp->event_handler)
 569                qp->event_handler(qp->cb_data, NTB_LINK_DOWN);
 570
 571        dev_info(&pdev->dev, "qp %d: Link Down\n", qp->qp_num);
 572        qp->qp_link = NTB_LINK_DOWN;
 573
 574        if (nt->transport_link == NTB_LINK_UP)
 575                schedule_delayed_work(&qp->link_work,
 576                                      msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 577}
 578
 579static void ntb_qp_link_down(struct ntb_transport_qp *qp)
 580{
 581        schedule_work(&qp->link_cleanup);
 582}
 583
 584static void ntb_transport_link_cleanup(struct work_struct *work)
 585{
 586        struct ntb_transport *nt = container_of(work, struct ntb_transport,
 587                                                link_cleanup);
 588        int i;
 589
 590        if (nt->transport_link == NTB_LINK_DOWN)
 591                cancel_delayed_work_sync(&nt->link_work);
 592        else
 593                nt->transport_link = NTB_LINK_DOWN;
 594
 595        /* Pass along the info to any clients */
 596        for (i = 0; i < nt->max_qps; i++)
 597                if (!test_bit(i, &nt->qp_bitmap))
 598                        ntb_qp_link_down(&nt->qps[i]);
 599
 600        /* The scratchpad registers keep the values if the remote side
 601         * goes down, blast them now to give them a sane value the next
 602         * time they are accessed
 603         */
 604        for (i = 0; i < MAX_SPAD; i++)
 605                ntb_write_local_spad(nt->ndev, i, 0);
 606}
 607
 608static void ntb_transport_event_callback(void *data, enum ntb_hw_event event)
 609{
 610        struct ntb_transport *nt = data;
 611
 612        switch (event) {
 613        case NTB_EVENT_HW_LINK_UP:
 614                schedule_delayed_work(&nt->link_work, 0);
 615                break;
 616        case NTB_EVENT_HW_LINK_DOWN:
 617                schedule_work(&nt->link_cleanup);
 618                break;
 619        default:
 620                BUG();
 621        }
 622}
 623
 624static void ntb_transport_link_work(struct work_struct *work)
 625{
 626        struct ntb_transport *nt = container_of(work, struct ntb_transport,
 627                                                link_work.work);
 628        struct ntb_device *ndev = nt->ndev;
 629        struct pci_dev *pdev = ntb_query_pdev(ndev);
 630        u32 val;
 631        int rc, i;
 632
 633        /* send the local info, in the opposite order of the way we read it */
 634        for (i = 0; i < NTB_NUM_MW; i++) {
 635                rc = ntb_write_remote_spad(ndev, MW0_SZ_HIGH + (i * 2),
 636                                           ntb_get_mw_size(ndev, i) >> 32);
 637                if (rc) {
 638                        dev_err(&pdev->dev, "Error writing %u to remote spad %d\n",
 639                                (u32)(ntb_get_mw_size(ndev, i) >> 32),
 640                                MW0_SZ_HIGH + (i * 2));
 641                        goto out;
 642                }
 643
 644                rc = ntb_write_remote_spad(ndev, MW0_SZ_LOW + (i * 2),
 645                                           (u32) ntb_get_mw_size(ndev, i));
 646                if (rc) {
 647                        dev_err(&pdev->dev, "Error writing %u to remote spad %d\n",
 648                                (u32) ntb_get_mw_size(ndev, i),
 649                                MW0_SZ_LOW + (i * 2));
 650                        goto out;
 651                }
 652        }
 653
 654        rc = ntb_write_remote_spad(ndev, NUM_MWS, NTB_NUM_MW);
 655        if (rc) {
 656                dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
 657                        NTB_NUM_MW, NUM_MWS);
 658                goto out;
 659        }
 660
 661        rc = ntb_write_remote_spad(ndev, NUM_QPS, nt->max_qps);
 662        if (rc) {
 663                dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
 664                        nt->max_qps, NUM_QPS);
 665                goto out;
 666        }
 667
 668        rc = ntb_write_remote_spad(ndev, VERSION, NTB_TRANSPORT_VERSION);
 669        if (rc) {
 670                dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
 671                        NTB_TRANSPORT_VERSION, VERSION);
 672                goto out;
 673        }
 674
 675        /* Query the remote side for its info */
 676        rc = ntb_read_remote_spad(ndev, VERSION, &val);
 677        if (rc) {
 678                dev_err(&pdev->dev, "Error reading remote spad %d\n", VERSION);
 679                goto out;
 680        }
 681
 682        if (val != NTB_TRANSPORT_VERSION)
 683                goto out;
 684        dev_dbg(&pdev->dev, "Remote version = %d\n", val);
 685
 686        rc = ntb_read_remote_spad(ndev, NUM_QPS, &val);
 687        if (rc) {
 688                dev_err(&pdev->dev, "Error reading remote spad %d\n", NUM_QPS);
 689                goto out;
 690        }
 691
 692        if (val != nt->max_qps)
 693                goto out;
 694        dev_dbg(&pdev->dev, "Remote max number of qps = %d\n", val);
 695
 696        rc = ntb_read_remote_spad(ndev, NUM_MWS, &val);
 697        if (rc) {
 698                dev_err(&pdev->dev, "Error reading remote spad %d\n", NUM_MWS);
 699                goto out;
 700        }
 701
 702        if (val != NTB_NUM_MW)
 703                goto out;
 704        dev_dbg(&pdev->dev, "Remote number of mws = %d\n", val);
 705
 706        for (i = 0; i < NTB_NUM_MW; i++) {
 707                u64 val64;
 708
 709                rc = ntb_read_remote_spad(ndev, MW0_SZ_HIGH + (i * 2), &val);
 710                if (rc) {
 711                        dev_err(&pdev->dev, "Error reading remote spad %d\n",
 712                                MW0_SZ_HIGH + (i * 2));
 713                        goto out1;
 714                }
 715
 716                val64 = (u64) val << 32;
 717
 718                rc = ntb_read_remote_spad(ndev, MW0_SZ_LOW + (i * 2), &val);
 719                if (rc) {
 720                        dev_err(&pdev->dev, "Error reading remote spad %d\n",
 721                                MW0_SZ_LOW + (i * 2));
 722                        goto out1;
 723                }
 724
 725                val64 |= val;
 726
 727                dev_dbg(&pdev->dev, "Remote MW%d size = %llu\n", i, val64);
 728
 729                rc = ntb_set_mw(nt, i, val64);
 730                if (rc)
 731                        goto out1;
 732        }
 733
 734        nt->transport_link = NTB_LINK_UP;
 735
 736        for (i = 0; i < nt->max_qps; i++) {
 737                struct ntb_transport_qp *qp = &nt->qps[i];
 738
 739                ntb_transport_setup_qp_mw(nt, i);
 740
 741                if (qp->client_ready == NTB_LINK_UP)
 742                        schedule_delayed_work(&qp->link_work, 0);
 743        }
 744
 745        return;
 746
 747out1:
 748        for (i = 0; i < NTB_NUM_MW; i++)
 749                ntb_free_mw(nt, i);
 750out:
 751        if (ntb_hw_link_status(ndev))
 752                schedule_delayed_work(&nt->link_work,
 753                                      msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 754}
 755
 756static void ntb_qp_link_work(struct work_struct *work)
 757{
 758        struct ntb_transport_qp *qp = container_of(work,
 759                                                   struct ntb_transport_qp,
 760                                                   link_work.work);
 761        struct pci_dev *pdev = ntb_query_pdev(qp->ndev);
 762        struct ntb_transport *nt = qp->transport;
 763        int rc, val;
 764
 765        WARN_ON(nt->transport_link != NTB_LINK_UP);
 766
 767        rc = ntb_read_local_spad(nt->ndev, QP_LINKS, &val);
 768        if (rc) {
 769                dev_err(&pdev->dev, "Error reading spad %d\n", QP_LINKS);
 770                return;
 771        }
 772
 773        rc = ntb_write_remote_spad(nt->ndev, QP_LINKS, val | 1 << qp->qp_num);
 774        if (rc)
 775                dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
 776                        val | 1 << qp->qp_num, QP_LINKS);
 777
 778        /* query remote spad for qp ready bits */
 779        rc = ntb_read_remote_spad(nt->ndev, QP_LINKS, &val);
 780        if (rc)
 781                dev_err(&pdev->dev, "Error reading remote spad %d\n", QP_LINKS);
 782
 783        dev_dbg(&pdev->dev, "Remote QP link status = %x\n", val);
 784
 785        /* See if the remote side is up */
 786        if (1 << qp->qp_num & val) {
 787                qp->qp_link = NTB_LINK_UP;
 788
 789                dev_info(&pdev->dev, "qp %d: Link Up\n", qp->qp_num);
 790                if (qp->event_handler)
 791                        qp->event_handler(qp->cb_data, NTB_LINK_UP);
 792        } else if (nt->transport_link == NTB_LINK_UP)
 793                schedule_delayed_work(&qp->link_work,
 794                                      msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 795}
 796
 797static void ntb_transport_init_queue(struct ntb_transport *nt,
 798                                     unsigned int qp_num)
 799{
 800        struct ntb_transport_qp *qp;
 801        unsigned int num_qps_mw, tx_size;
 802        u8 mw_num = QP_TO_MW(qp_num);
 803
 804        qp = &nt->qps[qp_num];
 805        qp->qp_num = qp_num;
 806        qp->transport = nt;
 807        qp->ndev = nt->ndev;
 808        qp->qp_link = NTB_LINK_DOWN;
 809        qp->client_ready = NTB_LINK_DOWN;
 810        qp->event_handler = NULL;
 811
 812        if (nt->max_qps % NTB_NUM_MW && mw_num < nt->max_qps % NTB_NUM_MW)
 813                num_qps_mw = nt->max_qps / NTB_NUM_MW + 1;
 814        else
 815                num_qps_mw = nt->max_qps / NTB_NUM_MW;
 816
 817        tx_size = (unsigned int) ntb_get_mw_size(qp->ndev, mw_num) / num_qps_mw;
 818        qp->rx_info = ntb_get_mw_vbase(nt->ndev, mw_num) +
 819                      (qp_num / NTB_NUM_MW * tx_size);
 820        tx_size -= sizeof(struct ntb_rx_info);
 821
 822        qp->tx_mw = qp->rx_info + 1;
 823        /* Due to housekeeping, there must be atleast 2 buffs */
 824        qp->tx_max_frame = min(transport_mtu, tx_size / 2);
 825        qp->tx_max_entry = tx_size / qp->tx_max_frame;
 826
 827        if (nt->debugfs_dir) {
 828                char debugfs_name[4];
 829
 830                snprintf(debugfs_name, 4, "qp%d", qp_num);
 831                qp->debugfs_dir = debugfs_create_dir(debugfs_name,
 832                                                     nt->debugfs_dir);
 833
 834                qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR,
 835                                                        qp->debugfs_dir, qp,
 836                                                        &ntb_qp_debugfs_stats);
 837        }
 838
 839        INIT_DELAYED_WORK(&qp->link_work, ntb_qp_link_work);
 840        INIT_WORK(&qp->link_cleanup, ntb_qp_link_cleanup);
 841
 842        spin_lock_init(&qp->ntb_rx_pend_q_lock);
 843        spin_lock_init(&qp->ntb_rx_free_q_lock);
 844        spin_lock_init(&qp->ntb_tx_free_q_lock);
 845
 846        INIT_LIST_HEAD(&qp->rx_pend_q);
 847        INIT_LIST_HEAD(&qp->rx_free_q);
 848        INIT_LIST_HEAD(&qp->tx_free_q);
 849}
 850
 851int ntb_transport_init(struct pci_dev *pdev)
 852{
 853        struct ntb_transport *nt;
 854        int rc, i;
 855
 856        nt = kzalloc(sizeof(struct ntb_transport), GFP_KERNEL);
 857        if (!nt)
 858                return -ENOMEM;
 859
 860        if (debugfs_initialized())
 861                nt->debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
 862        else
 863                nt->debugfs_dir = NULL;
 864
 865        nt->ndev = ntb_register_transport(pdev, nt);
 866        if (!nt->ndev) {
 867                rc = -EIO;
 868                goto err;
 869        }
 870
 871        nt->max_qps = min(nt->ndev->max_cbs, max_num_clients);
 872
 873        nt->qps = kcalloc(nt->max_qps, sizeof(struct ntb_transport_qp),
 874                          GFP_KERNEL);
 875        if (!nt->qps) {
 876                rc = -ENOMEM;
 877                goto err1;
 878        }
 879
 880        nt->qp_bitmap = ((u64) 1 << nt->max_qps) - 1;
 881
 882        for (i = 0; i < nt->max_qps; i++)
 883                ntb_transport_init_queue(nt, i);
 884
 885        INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work);
 886        INIT_WORK(&nt->link_cleanup, ntb_transport_link_cleanup);
 887
 888        rc = ntb_register_event_callback(nt->ndev,
 889                                         ntb_transport_event_callback);
 890        if (rc)
 891                goto err2;
 892
 893        INIT_LIST_HEAD(&nt->client_devs);
 894        rc = ntb_bus_init(nt);
 895        if (rc)
 896                goto err3;
 897
 898        if (ntb_hw_link_status(nt->ndev))
 899                schedule_delayed_work(&nt->link_work, 0);
 900
 901        return 0;
 902
 903err3:
 904        ntb_unregister_event_callback(nt->ndev);
 905err2:
 906        kfree(nt->qps);
 907err1:
 908        ntb_unregister_transport(nt->ndev);
 909err:
 910        debugfs_remove_recursive(nt->debugfs_dir);
 911        kfree(nt);
 912        return rc;
 913}
 914
 915void ntb_transport_free(void *transport)
 916{
 917        struct ntb_transport *nt = transport;
 918        struct pci_dev *pdev;
 919        int i;
 920
 921        nt->transport_link = NTB_LINK_DOWN;
 922
 923        /* verify that all the qp's are freed */
 924        for (i = 0; i < nt->max_qps; i++)
 925                if (!test_bit(i, &nt->qp_bitmap))
 926                        ntb_transport_free_queue(&nt->qps[i]);
 927
 928        ntb_bus_remove(nt);
 929
 930        cancel_delayed_work_sync(&nt->link_work);
 931
 932        debugfs_remove_recursive(nt->debugfs_dir);
 933
 934        ntb_unregister_event_callback(nt->ndev);
 935
 936        pdev = ntb_query_pdev(nt->ndev);
 937
 938        for (i = 0; i < NTB_NUM_MW; i++)
 939                ntb_free_mw(nt, i);
 940
 941        kfree(nt->qps);
 942        ntb_unregister_transport(nt->ndev);
 943        kfree(nt);
 944}
 945
 946static void ntb_rx_copy_task(struct ntb_transport_qp *qp,
 947                             struct ntb_queue_entry *entry, void *offset)
 948{
 949        void *cb_data = entry->cb_data;
 950        unsigned int len = entry->len;
 951
 952        memcpy(entry->buf, offset, entry->len);
 953
 954        ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry, &qp->rx_free_q);
 955
 956        if (qp->rx_handler && qp->client_ready == NTB_LINK_UP)
 957                qp->rx_handler(qp, qp->cb_data, cb_data, len);
 958}
 959
 960static int ntb_process_rxc(struct ntb_transport_qp *qp)
 961{
 962        struct ntb_payload_header *hdr;
 963        struct ntb_queue_entry *entry;
 964        void *offset;
 965
 966        offset = qp->rx_buff + qp->rx_max_frame * qp->rx_index;
 967        hdr = offset + qp->rx_max_frame - sizeof(struct ntb_payload_header);
 968
 969        entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q);
 970        if (!entry) {
 971                dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
 972                        "no buffer - HDR ver %u, len %d, flags %x\n",
 973                        hdr->ver, hdr->len, hdr->flags);
 974                qp->rx_err_no_buf++;
 975                return -ENOMEM;
 976        }
 977
 978        if (!(hdr->flags & DESC_DONE_FLAG)) {
 979                ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
 980                             &qp->rx_pend_q);
 981                qp->rx_ring_empty++;
 982                return -EAGAIN;
 983        }
 984
 985        if (hdr->ver != (u32) qp->rx_pkts) {
 986                dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
 987                        "qp %d: version mismatch, expected %llu - got %u\n",
 988                        qp->qp_num, qp->rx_pkts, hdr->ver);
 989                ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
 990                             &qp->rx_pend_q);
 991                qp->rx_err_ver++;
 992                return -EIO;
 993        }
 994
 995        if (hdr->flags & LINK_DOWN_FLAG) {
 996                ntb_qp_link_down(qp);
 997
 998                ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
 999                             &qp->rx_pend_q);
1000                goto out;
1001        }
1002
1003        dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
1004                "rx offset %u, ver %u - %d payload received, buf size %d\n",
1005                qp->rx_index, hdr->ver, hdr->len, entry->len);
1006
1007        if (hdr->len <= entry->len) {
1008                entry->len = hdr->len;
1009                ntb_rx_copy_task(qp, entry, offset);
1010        } else {
1011                ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
1012                             &qp->rx_pend_q);
1013
1014                qp->rx_err_oflow++;
1015                dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
1016                        "RX overflow! Wanted %d got %d\n",
1017                        hdr->len, entry->len);
1018        }
1019
1020        qp->rx_bytes += hdr->len;
1021        qp->rx_pkts++;
1022
1023out:
1024        /* Ensure that the data is fully copied out before clearing the flag */
1025        wmb();
1026        hdr->flags = 0;
1027        iowrite32(qp->rx_index, &qp->rx_info->entry);
1028
1029        qp->rx_index++;
1030        qp->rx_index %= qp->rx_max_entry;
1031
1032        return 0;
1033}
1034
1035static void ntb_transport_rx(unsigned long data)
1036{
1037        struct ntb_transport_qp *qp = (struct ntb_transport_qp *)data;
1038        int rc, i;
1039
1040        /* Limit the number of packets processed in a single interrupt to
1041         * provide fairness to others
1042         */
1043        for (i = 0; i < qp->rx_max_entry; i++) {
1044                rc = ntb_process_rxc(qp);
1045                if (rc)
1046                        break;
1047        }
1048}
1049
1050static void ntb_transport_rxc_db(void *data, int db_num)
1051{
1052        struct ntb_transport_qp *qp = data;
1053
1054        dev_dbg(&ntb_query_pdev(qp->ndev)->dev, "%s: doorbell %d received\n",
1055                __func__, db_num);
1056
1057        tasklet_schedule(&qp->rx_work);
1058}
1059
1060static void ntb_tx_copy_task(struct ntb_transport_qp *qp,
1061                             struct ntb_queue_entry *entry,
1062                             void __iomem *offset)
1063{
1064        struct ntb_payload_header __iomem *hdr;
1065
1066        memcpy_toio(offset, entry->buf, entry->len);
1067
1068        hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
1069        iowrite32(entry->len, &hdr->len);
1070        iowrite32((u32) qp->tx_pkts, &hdr->ver);
1071
1072        /* Ensure that the data is fully copied out before setting the flag */
1073        wmb();
1074        iowrite32(entry->flags | DESC_DONE_FLAG, &hdr->flags);
1075
1076        ntb_ring_sdb(qp->ndev, qp->qp_num);
1077
1078        /* The entry length can only be zero if the packet is intended to be a
1079         * "link down" or similar.  Since no payload is being sent in these
1080         * cases, there is nothing to add to the completion queue.
1081         */
1082        if (entry->len > 0) {
1083                qp->tx_bytes += entry->len;
1084
1085                if (qp->tx_handler)
1086                        qp->tx_handler(qp, qp->cb_data, entry->cb_data,
1087                                       entry->len);
1088        }
1089
1090        ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q);
1091}
1092
1093static int ntb_process_tx(struct ntb_transport_qp *qp,
1094                          struct ntb_queue_entry *entry)
1095{
1096        void __iomem *offset;
1097
1098        offset = qp->tx_mw + qp->tx_max_frame * qp->tx_index;
1099
1100        dev_dbg(&ntb_query_pdev(qp->ndev)->dev, "%lld - offset %p, tx %u, entry len %d flags %x buff %p\n",
1101                qp->tx_pkts, offset, qp->tx_index, entry->len, entry->flags,
1102                entry->buf);
1103        if (qp->tx_index == qp->remote_rx_info->entry) {
1104                qp->tx_ring_full++;
1105                return -EAGAIN;
1106        }
1107
1108        if (entry->len > qp->tx_max_frame - sizeof(struct ntb_payload_header)) {
1109                if (qp->tx_handler)
1110                        qp->tx_handler(qp->cb_data, qp, NULL, -EIO);
1111
1112                ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1113                             &qp->tx_free_q);
1114                return 0;
1115        }
1116
1117        ntb_tx_copy_task(qp, entry, offset);
1118
1119        qp->tx_index++;
1120        qp->tx_index %= qp->tx_max_entry;
1121
1122        qp->tx_pkts++;
1123
1124        return 0;
1125}
1126
1127static void ntb_send_link_down(struct ntb_transport_qp *qp)
1128{
1129        struct pci_dev *pdev = ntb_query_pdev(qp->ndev);
1130        struct ntb_queue_entry *entry;
1131        int i, rc;
1132
1133        if (qp->qp_link == NTB_LINK_DOWN)
1134                return;
1135
1136        qp->qp_link = NTB_LINK_DOWN;
1137        dev_info(&pdev->dev, "qp %d: Link Down\n", qp->qp_num);
1138
1139        for (i = 0; i < NTB_LINK_DOWN_TIMEOUT; i++) {
1140                entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1141                if (entry)
1142                        break;
1143                msleep(100);
1144        }
1145
1146        if (!entry)
1147                return;
1148
1149        entry->cb_data = NULL;
1150        entry->buf = NULL;
1151        entry->len = 0;
1152        entry->flags = LINK_DOWN_FLAG;
1153
1154        rc = ntb_process_tx(qp, entry);
1155        if (rc)
1156                dev_err(&pdev->dev, "ntb: QP%d unable to send linkdown msg\n",
1157                        qp->qp_num);
1158}
1159
1160/**
1161 * ntb_transport_create_queue - Create a new NTB transport layer queue
1162 * @rx_handler: receive callback function
1163 * @tx_handler: transmit callback function
1164 * @event_handler: event callback function
1165 *
1166 * Create a new NTB transport layer queue and provide the queue with a callback
1167 * routine for both transmit and receive.  The receive callback routine will be
1168 * used to pass up data when the transport has received it on the queue.   The
1169 * transmit callback routine will be called when the transport has completed the
1170 * transmission of the data on the queue and the data is ready to be freed.
1171 *
1172 * RETURNS: pointer to newly created ntb_queue, NULL on error.
1173 */
1174struct ntb_transport_qp *
1175ntb_transport_create_queue(void *data, struct pci_dev *pdev,
1176                           const struct ntb_queue_handlers *handlers)
1177{
1178        struct ntb_queue_entry *entry;
1179        struct ntb_transport_qp *qp;
1180        struct ntb_transport *nt;
1181        unsigned int free_queue;
1182        int rc, i;
1183
1184        nt = ntb_find_transport(pdev);
1185        if (!nt)
1186                goto err;
1187
1188        free_queue = ffs(nt->qp_bitmap);
1189        if (!free_queue)
1190                goto err;
1191
1192        /* decrement free_queue to make it zero based */
1193        free_queue--;
1194
1195        clear_bit(free_queue, &nt->qp_bitmap);
1196
1197        qp = &nt->qps[free_queue];
1198        qp->cb_data = data;
1199        qp->rx_handler = handlers->rx_handler;
1200        qp->tx_handler = handlers->tx_handler;
1201        qp->event_handler = handlers->event_handler;
1202
1203        for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
1204                entry = kzalloc(sizeof(struct ntb_queue_entry), GFP_ATOMIC);
1205                if (!entry)
1206                        goto err1;
1207
1208                ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry,
1209                             &qp->rx_free_q);
1210        }
1211
1212        for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
1213                entry = kzalloc(sizeof(struct ntb_queue_entry), GFP_ATOMIC);
1214                if (!entry)
1215                        goto err2;
1216
1217                ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1218                             &qp->tx_free_q);
1219        }
1220
1221        tasklet_init(&qp->rx_work, ntb_transport_rx, (unsigned long) qp);
1222
1223        rc = ntb_register_db_callback(qp->ndev, free_queue, qp,
1224                                      ntb_transport_rxc_db);
1225        if (rc)
1226                goto err3;
1227
1228        dev_info(&pdev->dev, "NTB Transport QP %d created\n", qp->qp_num);
1229
1230        return qp;
1231
1232err3:
1233        tasklet_disable(&qp->rx_work);
1234err2:
1235        while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1236                kfree(entry);
1237err1:
1238        while ((entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q)))
1239                kfree(entry);
1240        set_bit(free_queue, &nt->qp_bitmap);
1241err:
1242        return NULL;
1243}
1244EXPORT_SYMBOL_GPL(ntb_transport_create_queue);
1245
1246/**
1247 * ntb_transport_free_queue - Frees NTB transport queue
1248 * @qp: NTB queue to be freed
1249 *
1250 * Frees NTB transport queue
1251 */
1252void ntb_transport_free_queue(struct ntb_transport_qp *qp)
1253{
1254        struct pci_dev *pdev;
1255        struct ntb_queue_entry *entry;
1256
1257        if (!qp)
1258                return;
1259
1260        pdev = ntb_query_pdev(qp->ndev);
1261
1262        cancel_delayed_work_sync(&qp->link_work);
1263
1264        ntb_unregister_db_callback(qp->ndev, qp->qp_num);
1265        tasklet_disable(&qp->rx_work);
1266
1267        while ((entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q)))
1268                kfree(entry);
1269
1270        while ((entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q))) {
1271                dev_warn(&pdev->dev, "Freeing item from a non-empty queue\n");
1272                kfree(entry);
1273        }
1274
1275        while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1276                kfree(entry);
1277
1278        set_bit(qp->qp_num, &qp->transport->qp_bitmap);
1279
1280        dev_info(&pdev->dev, "NTB Transport QP %d freed\n", qp->qp_num);
1281}
1282EXPORT_SYMBOL_GPL(ntb_transport_free_queue);
1283
1284/**
1285 * ntb_transport_rx_remove - Dequeues enqueued rx packet
1286 * @qp: NTB queue to be freed
1287 * @len: pointer to variable to write enqueued buffers length
1288 *
1289 * Dequeues unused buffers from receive queue.  Should only be used during
1290 * shutdown of qp.
1291 *
1292 * RETURNS: NULL error value on error, or void* for success.
1293 */
1294void *ntb_transport_rx_remove(struct ntb_transport_qp *qp, unsigned int *len)
1295{
1296        struct ntb_queue_entry *entry;
1297        void *buf;
1298
1299        if (!qp || qp->client_ready == NTB_LINK_UP)
1300                return NULL;
1301
1302        entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q);
1303        if (!entry)
1304                return NULL;
1305
1306        buf = entry->cb_data;
1307        *len = entry->len;
1308
1309        ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry, &qp->rx_free_q);
1310
1311        return buf;
1312}
1313EXPORT_SYMBOL_GPL(ntb_transport_rx_remove);
1314
1315/**
1316 * ntb_transport_rx_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 incoming packets will be copied into
1320 * @len: length of the data buffer
1321 *
1322 * Enqueue a new receive buffer onto the transport queue into which a NTB
1323 * payload can be received into.
1324 *
1325 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
1326 */
1327int ntb_transport_rx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
1328                             unsigned int len)
1329{
1330        struct ntb_queue_entry *entry;
1331
1332        if (!qp)
1333                return -EINVAL;
1334
1335        entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q);
1336        if (!entry)
1337                return -ENOMEM;
1338
1339        entry->cb_data = cb;
1340        entry->buf = data;
1341        entry->len = len;
1342
1343        ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry, &qp->rx_pend_q);
1344
1345        return 0;
1346}
1347EXPORT_SYMBOL_GPL(ntb_transport_rx_enqueue);
1348
1349/**
1350 * ntb_transport_tx_enqueue - Enqueue a new NTB queue entry
1351 * @qp: NTB transport layer queue the entry is to be enqueued on
1352 * @cb: per buffer pointer for callback function to use
1353 * @data: pointer to data buffer that will be sent
1354 * @len: length of the data buffer
1355 *
1356 * Enqueue a new transmit buffer onto the transport queue from which a NTB
1357 * payload will be transmitted.  This assumes that a lock is behing held to
1358 * serialize access to the qp.
1359 *
1360 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
1361 */
1362int ntb_transport_tx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
1363                             unsigned int len)
1364{
1365        struct ntb_queue_entry *entry;
1366        int rc;
1367
1368        if (!qp || qp->qp_link != NTB_LINK_UP || !len)
1369                return -EINVAL;
1370
1371        entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1372        if (!entry)
1373                return -ENOMEM;
1374
1375        entry->cb_data = cb;
1376        entry->buf = data;
1377        entry->len = len;
1378        entry->flags = 0;
1379
1380        rc = ntb_process_tx(qp, entry);
1381        if (rc)
1382                ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1383                             &qp->tx_free_q);
1384
1385        return rc;
1386}
1387EXPORT_SYMBOL_GPL(ntb_transport_tx_enqueue);
1388
1389/**
1390 * ntb_transport_link_up - Notify NTB transport of client readiness to use queue
1391 * @qp: NTB transport layer queue to be enabled
1392 *
1393 * Notify NTB transport layer of client readiness to use queue
1394 */
1395void ntb_transport_link_up(struct ntb_transport_qp *qp)
1396{
1397        if (!qp)
1398                return;
1399
1400        qp->client_ready = NTB_LINK_UP;
1401
1402        if (qp->transport->transport_link == NTB_LINK_UP)
1403                schedule_delayed_work(&qp->link_work, 0);
1404}
1405EXPORT_SYMBOL_GPL(ntb_transport_link_up);
1406
1407/**
1408 * ntb_transport_link_down - Notify NTB transport to no longer enqueue data
1409 * @qp: NTB transport layer queue to be disabled
1410 *
1411 * Notify NTB transport layer of client's desire to no longer receive data on
1412 * transport queue specified.  It is the client's responsibility to ensure all
1413 * entries on queue are purged or otherwise handled appropraitely.
1414 */
1415void ntb_transport_link_down(struct ntb_transport_qp *qp)
1416{
1417        struct pci_dev *pdev;
1418        int rc, val;
1419
1420        if (!qp)
1421                return;
1422
1423        pdev = ntb_query_pdev(qp->ndev);
1424        qp->client_ready = NTB_LINK_DOWN;
1425
1426        rc = ntb_read_local_spad(qp->ndev, QP_LINKS, &val);
1427        if (rc) {
1428                dev_err(&pdev->dev, "Error reading spad %d\n", QP_LINKS);
1429                return;
1430        }
1431
1432        rc = ntb_write_remote_spad(qp->ndev, QP_LINKS,
1433                                   val & ~(1 << qp->qp_num));
1434        if (rc)
1435                dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
1436                        val & ~(1 << qp->qp_num), QP_LINKS);
1437
1438        if (qp->qp_link == NTB_LINK_UP)
1439                ntb_send_link_down(qp);
1440        else
1441                cancel_delayed_work_sync(&qp->link_work);
1442}
1443EXPORT_SYMBOL_GPL(ntb_transport_link_down);
1444
1445/**
1446 * ntb_transport_link_query - Query transport link state
1447 * @qp: NTB transport layer queue to be queried
1448 *
1449 * Query connectivity to the remote system of the NTB transport queue
1450 *
1451 * RETURNS: true for link up or false for link down
1452 */
1453bool ntb_transport_link_query(struct ntb_transport_qp *qp)
1454{
1455        if (!qp)
1456                return false;
1457
1458        return qp->qp_link == NTB_LINK_UP;
1459}
1460EXPORT_SYMBOL_GPL(ntb_transport_link_query);
1461
1462/**
1463 * ntb_transport_qp_num - Query the qp number
1464 * @qp: NTB transport layer queue to be queried
1465 *
1466 * Query qp number of the NTB transport queue
1467 *
1468 * RETURNS: a zero based number specifying the qp number
1469 */
1470unsigned char ntb_transport_qp_num(struct ntb_transport_qp *qp)
1471{
1472        if (!qp)
1473                return 0;
1474
1475        return qp->qp_num;
1476}
1477EXPORT_SYMBOL_GPL(ntb_transport_qp_num);
1478
1479/**
1480 * ntb_transport_max_size - Query the max payload size of a qp
1481 * @qp: NTB transport layer queue to be queried
1482 *
1483 * Query the maximum payload size permissible on the given qp
1484 *
1485 * RETURNS: the max payload size of a qp
1486 */
1487unsigned int ntb_transport_max_size(struct ntb_transport_qp *qp)
1488{
1489        if (!qp)
1490                return 0;
1491
1492        return qp->tx_max_frame - sizeof(struct ntb_payload_header);
1493}
1494EXPORT_SYMBOL_GPL(ntb_transport_max_size);
1495
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