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 *   Copyright (C) 2015 EMC Corporation. All Rights Reserved.
   9 *
  10 *   This program is free software; you can redistribute it and/or modify
  11 *   it under the terms of version 2 of the GNU General Public License as
  12 *   published by the Free Software Foundation.
  13 *
  14 *   BSD LICENSE
  15 *
  16 *   Copyright(c) 2012 Intel Corporation. All rights reserved.
  17 *   Copyright (C) 2015 EMC Corporation. All Rights Reserved.
  18 *
  19 *   Redistribution and use in source and binary forms, with or without
  20 *   modification, are permitted provided that the following conditions
  21 *   are met:
  22 *
  23 *     * Redistributions of source code must retain the above copyright
  24 *       notice, this list of conditions and the following disclaimer.
  25 *     * Redistributions in binary form must reproduce the above copy
  26 *       notice, this list of conditions and the following disclaimer in
  27 *       the documentation and/or other materials provided with the
  28 *       distribution.
  29 *     * Neither the name of Intel Corporation nor the names of its
  30 *       contributors may be used to endorse or promote products derived
  31 *       from this software without specific prior written permission.
  32 *
  33 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  34 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  35 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  36 *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  37 *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  38 *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  39 *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  40 *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  41 *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  42 *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  43 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  44 *
  45 * PCIe NTB Transport Linux driver
  46 *
  47 * Contact Information:
  48 * Jon Mason <jon.mason@intel.com>
  49 */
  50#include <linux/debugfs.h>
  51#include <linux/delay.h>
  52#include <linux/dmaengine.h>
  53#include <linux/dma-mapping.h>
  54#include <linux/errno.h>
  55#include <linux/export.h>
  56#include <linux/interrupt.h>
  57#include <linux/module.h>
  58#include <linux/pci.h>
  59#include <linux/slab.h>
  60#include <linux/types.h>
  61#include <linux/uaccess.h>
  62#include "linux/ntb.h"
  63#include "linux/ntb_transport.h"
  64
  65#define NTB_TRANSPORT_VERSION   4
  66#define NTB_TRANSPORT_VER       "4"
  67#define NTB_TRANSPORT_NAME      "ntb_transport"
  68#define NTB_TRANSPORT_DESC      "Software Queue-Pair Transport over NTB"
  69#define NTB_TRANSPORT_MIN_SPADS (MW0_SZ_HIGH + 2)
  70
  71MODULE_DESCRIPTION(NTB_TRANSPORT_DESC);
  72MODULE_VERSION(NTB_TRANSPORT_VER);
  73MODULE_LICENSE("Dual BSD/GPL");
  74MODULE_AUTHOR("Intel Corporation");
  75
  76static unsigned long max_mw_size;
  77module_param(max_mw_size, ulong, 0644);
  78MODULE_PARM_DESC(max_mw_size, "Limit size of large memory windows");
  79
  80static unsigned int transport_mtu = 0x10000;
  81module_param(transport_mtu, uint, 0644);
  82MODULE_PARM_DESC(transport_mtu, "Maximum size of NTB transport packets");
  83
  84static unsigned char max_num_clients;
  85module_param(max_num_clients, byte, 0644);
  86MODULE_PARM_DESC(max_num_clients, "Maximum number of NTB transport clients");
  87
  88static unsigned int copy_bytes = 1024;
  89module_param(copy_bytes, uint, 0644);
  90MODULE_PARM_DESC(copy_bytes, "Threshold under which NTB will use the CPU to copy instead of DMA");
  91
  92static bool use_dma;
  93module_param(use_dma, bool, 0644);
  94MODULE_PARM_DESC(use_dma, "Use DMA engine to perform large data copy");
  95
  96static bool use_msi;
  97#ifdef CONFIG_NTB_MSI
  98module_param(use_msi, bool, 0644);
  99MODULE_PARM_DESC(use_msi, "Use MSI interrupts instead of doorbells");
 100#endif
 101
 102static struct dentry *nt_debugfs_dir;
 103
 104/* Only two-ports NTB devices are supported */
 105#define PIDX            NTB_DEF_PEER_IDX
 106
 107struct ntb_queue_entry {
 108        /* ntb_queue list reference */
 109        struct list_head entry;
 110        /* pointers to data to be transferred */
 111        void *cb_data;
 112        void *buf;
 113        unsigned int len;
 114        unsigned int flags;
 115        int retries;
 116        int errors;
 117        unsigned int tx_index;
 118        unsigned int rx_index;
 119
 120        struct ntb_transport_qp *qp;
 121        union {
 122                struct ntb_payload_header __iomem *tx_hdr;
 123                struct ntb_payload_header *rx_hdr;
 124        };
 125};
 126
 127struct ntb_rx_info {
 128        unsigned int entry;
 129};
 130
 131struct ntb_transport_qp {
 132        struct ntb_transport_ctx *transport;
 133        struct ntb_dev *ndev;
 134        void *cb_data;
 135        struct dma_chan *tx_dma_chan;
 136        struct dma_chan *rx_dma_chan;
 137
 138        bool client_ready;
 139        bool link_is_up;
 140        bool active;
 141
 142        u8 qp_num;      /* Only 64 QP's are allowed.  0-63 */
 143        u64 qp_bit;
 144
 145        struct ntb_rx_info __iomem *rx_info;
 146        struct ntb_rx_info *remote_rx_info;
 147
 148        void (*tx_handler)(struct ntb_transport_qp *qp, void *qp_data,
 149                           void *data, int len);
 150        struct list_head tx_free_q;
 151        spinlock_t ntb_tx_free_q_lock;
 152        void __iomem *tx_mw;
 153        phys_addr_t tx_mw_phys;
 154        size_t tx_mw_size;
 155        dma_addr_t tx_mw_dma_addr;
 156        unsigned int tx_index;
 157        unsigned int tx_max_entry;
 158        unsigned int tx_max_frame;
 159
 160        void (*rx_handler)(struct ntb_transport_qp *qp, void *qp_data,
 161                           void *data, int len);
 162        struct list_head rx_post_q;
 163        struct list_head rx_pend_q;
 164        struct list_head rx_free_q;
 165        /* ntb_rx_q_lock: synchronize access to rx_XXXX_q */
 166        spinlock_t ntb_rx_q_lock;
 167        void *rx_buff;
 168        unsigned int rx_index;
 169        unsigned int rx_max_entry;
 170        unsigned int rx_max_frame;
 171        unsigned int rx_alloc_entry;
 172        dma_cookie_t last_cookie;
 173        struct tasklet_struct rxc_db_work;
 174
 175        void (*event_handler)(void *data, int status);
 176        struct delayed_work link_work;
 177        struct work_struct link_cleanup;
 178
 179        struct dentry *debugfs_dir;
 180        struct dentry *debugfs_stats;
 181
 182        /* Stats */
 183        u64 rx_bytes;
 184        u64 rx_pkts;
 185        u64 rx_ring_empty;
 186        u64 rx_err_no_buf;
 187        u64 rx_err_oflow;
 188        u64 rx_err_ver;
 189        u64 rx_memcpy;
 190        u64 rx_async;
 191        u64 tx_bytes;
 192        u64 tx_pkts;
 193        u64 tx_ring_full;
 194        u64 tx_err_no_buf;
 195        u64 tx_memcpy;
 196        u64 tx_async;
 197
 198        bool use_msi;
 199        int msi_irq;
 200        struct ntb_msi_desc msi_desc;
 201        struct ntb_msi_desc peer_msi_desc;
 202};
 203
 204struct ntb_transport_mw {
 205        phys_addr_t phys_addr;
 206        resource_size_t phys_size;
 207        void __iomem *vbase;
 208        size_t xlat_size;
 209        size_t buff_size;
 210        size_t alloc_size;
 211        void *alloc_addr;
 212        void *virt_addr;
 213        dma_addr_t dma_addr;
 214};
 215
 216struct ntb_transport_client_dev {
 217        struct list_head entry;
 218        struct ntb_transport_ctx *nt;
 219        struct device dev;
 220};
 221
 222struct ntb_transport_ctx {
 223        struct list_head entry;
 224        struct list_head client_devs;
 225
 226        struct ntb_dev *ndev;
 227
 228        struct ntb_transport_mw *mw_vec;
 229        struct ntb_transport_qp *qp_vec;
 230        unsigned int mw_count;
 231        unsigned int qp_count;
 232        u64 qp_bitmap;
 233        u64 qp_bitmap_free;
 234
 235        bool use_msi;
 236        unsigned int msi_spad_offset;
 237        u64 msi_db_mask;
 238
 239        bool link_is_up;
 240        struct delayed_work link_work;
 241        struct work_struct link_cleanup;
 242
 243        struct dentry *debugfs_node_dir;
 244};
 245
 246enum {
 247        DESC_DONE_FLAG = BIT(0),
 248        LINK_DOWN_FLAG = BIT(1),
 249};
 250
 251struct ntb_payload_header {
 252        unsigned int ver;
 253        unsigned int len;
 254        unsigned int flags;
 255};
 256
 257enum {
 258        VERSION = 0,
 259        QP_LINKS,
 260        NUM_QPS,
 261        NUM_MWS,
 262        MW0_SZ_HIGH,
 263        MW0_SZ_LOW,
 264};
 265
 266#define dev_client_dev(__dev) \
 267        container_of((__dev), struct ntb_transport_client_dev, dev)
 268
 269#define drv_client(__drv) \
 270        container_of((__drv), struct ntb_transport_client, driver)
 271
 272#define QP_TO_MW(nt, qp)        ((qp) % nt->mw_count)
 273#define NTB_QP_DEF_NUM_ENTRIES  100
 274#define NTB_LINK_DOWN_TIMEOUT   10
 275
 276static void ntb_transport_rxc_db(unsigned long data);
 277static const struct ntb_ctx_ops ntb_transport_ops;
 278static struct ntb_client ntb_transport_client;
 279static int ntb_async_tx_submit(struct ntb_transport_qp *qp,
 280                               struct ntb_queue_entry *entry);
 281static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset);
 282static int ntb_async_rx_submit(struct ntb_queue_entry *entry, void *offset);
 283static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void *offset);
 284
 285
 286static int ntb_transport_bus_match(struct device *dev,
 287                                   struct device_driver *drv)
 288{
 289        return !strncmp(dev_name(dev), drv->name, strlen(drv->name));
 290}
 291
 292static int ntb_transport_bus_probe(struct device *dev)
 293{
 294        const struct ntb_transport_client *client;
 295        int rc;
 296
 297        get_device(dev);
 298
 299        client = drv_client(dev->driver);
 300        rc = client->probe(dev);
 301        if (rc)
 302                put_device(dev);
 303
 304        return rc;
 305}
 306
 307static int ntb_transport_bus_remove(struct device *dev)
 308{
 309        const struct ntb_transport_client *client;
 310
 311        client = drv_client(dev->driver);
 312        client->remove(dev);
 313
 314        put_device(dev);
 315
 316        return 0;
 317}
 318
 319static struct bus_type ntb_transport_bus = {
 320        .name = "ntb_transport",
 321        .match = ntb_transport_bus_match,
 322        .probe = ntb_transport_bus_probe,
 323        .remove = ntb_transport_bus_remove,
 324};
 325
 326static LIST_HEAD(ntb_transport_list);
 327
 328static int ntb_bus_init(struct ntb_transport_ctx *nt)
 329{
 330        list_add_tail(&nt->entry, &ntb_transport_list);
 331        return 0;
 332}
 333
 334static void ntb_bus_remove(struct ntb_transport_ctx *nt)
 335{
 336        struct ntb_transport_client_dev *client_dev, *cd;
 337
 338        list_for_each_entry_safe(client_dev, cd, &nt->client_devs, entry) {
 339                dev_err(client_dev->dev.parent, "%s still attached to bus, removing\n",
 340                        dev_name(&client_dev->dev));
 341                list_del(&client_dev->entry);
 342                device_unregister(&client_dev->dev);
 343        }
 344
 345        list_del(&nt->entry);
 346}
 347
 348static void ntb_transport_client_release(struct device *dev)
 349{
 350        struct ntb_transport_client_dev *client_dev;
 351
 352        client_dev = dev_client_dev(dev);
 353        kfree(client_dev);
 354}
 355
 356/**
 357 * ntb_transport_unregister_client_dev - Unregister NTB client device
 358 * @device_name: Name of NTB client device
 359 *
 360 * Unregister an NTB client device with the NTB transport layer
 361 */
 362void ntb_transport_unregister_client_dev(char *device_name)
 363{
 364        struct ntb_transport_client_dev *client, *cd;
 365        struct ntb_transport_ctx *nt;
 366
 367        list_for_each_entry(nt, &ntb_transport_list, entry)
 368                list_for_each_entry_safe(client, cd, &nt->client_devs, entry)
 369                        if (!strncmp(dev_name(&client->dev), device_name,
 370                                     strlen(device_name))) {
 371                                list_del(&client->entry);
 372                                device_unregister(&client->dev);
 373                        }
 374}
 375EXPORT_SYMBOL_GPL(ntb_transport_unregister_client_dev);
 376
 377/**
 378 * ntb_transport_register_client_dev - Register NTB client device
 379 * @device_name: Name of NTB client device
 380 *
 381 * Register an NTB client device with the NTB transport layer
 382 */
 383int ntb_transport_register_client_dev(char *device_name)
 384{
 385        struct ntb_transport_client_dev *client_dev;
 386        struct ntb_transport_ctx *nt;
 387        int node;
 388        int rc, i = 0;
 389
 390        if (list_empty(&ntb_transport_list))
 391                return -ENODEV;
 392
 393        list_for_each_entry(nt, &ntb_transport_list, entry) {
 394                struct device *dev;
 395
 396                node = dev_to_node(&nt->ndev->dev);
 397
 398                client_dev = kzalloc_node(sizeof(*client_dev),
 399                                          GFP_KERNEL, node);
 400                if (!client_dev) {
 401                        rc = -ENOMEM;
 402                        goto err;
 403                }
 404
 405                dev = &client_dev->dev;
 406
 407                /* setup and register client devices */
 408                dev_set_name(dev, "%s%d", device_name, i);
 409                dev->bus = &ntb_transport_bus;
 410                dev->release = ntb_transport_client_release;
 411                dev->parent = &nt->ndev->dev;
 412
 413                rc = device_register(dev);
 414                if (rc) {
 415                        kfree(client_dev);
 416                        goto err;
 417                }
 418
 419                list_add_tail(&client_dev->entry, &nt->client_devs);
 420                i++;
 421        }
 422
 423        return 0;
 424
 425err:
 426        ntb_transport_unregister_client_dev(device_name);
 427
 428        return rc;
 429}
 430EXPORT_SYMBOL_GPL(ntb_transport_register_client_dev);
 431
 432/**
 433 * ntb_transport_register_client - Register NTB client driver
 434 * @drv: NTB client driver to be registered
 435 *
 436 * Register an NTB client driver with the NTB transport layer
 437 *
 438 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 439 */
 440int ntb_transport_register_client(struct ntb_transport_client *drv)
 441{
 442        drv->driver.bus = &ntb_transport_bus;
 443
 444        if (list_empty(&ntb_transport_list))
 445                return -ENODEV;
 446
 447        return driver_register(&drv->driver);
 448}
 449EXPORT_SYMBOL_GPL(ntb_transport_register_client);
 450
 451/**
 452 * ntb_transport_unregister_client - Unregister NTB client driver
 453 * @drv: NTB client driver to be unregistered
 454 *
 455 * Unregister an NTB client driver with the NTB transport layer
 456 *
 457 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 458 */
 459void ntb_transport_unregister_client(struct ntb_transport_client *drv)
 460{
 461        driver_unregister(&drv->driver);
 462}
 463EXPORT_SYMBOL_GPL(ntb_transport_unregister_client);
 464
 465static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count,
 466                            loff_t *offp)
 467{
 468        struct ntb_transport_qp *qp;
 469        char *buf;
 470        ssize_t ret, out_offset, out_count;
 471
 472        qp = filp->private_data;
 473
 474        if (!qp || !qp->link_is_up)
 475                return 0;
 476
 477        out_count = 1000;
 478
 479        buf = kmalloc(out_count, GFP_KERNEL);
 480        if (!buf)
 481                return -ENOMEM;
 482
 483        out_offset = 0;
 484        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 485                               "\nNTB QP stats:\n\n");
 486        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 487                               "rx_bytes - \t%llu\n", qp->rx_bytes);
 488        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 489                               "rx_pkts - \t%llu\n", qp->rx_pkts);
 490        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 491                               "rx_memcpy - \t%llu\n", qp->rx_memcpy);
 492        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 493                               "rx_async - \t%llu\n", qp->rx_async);
 494        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 495                               "rx_ring_empty - %llu\n", qp->rx_ring_empty);
 496        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 497                               "rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
 498        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 499                               "rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
 500        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 501                               "rx_err_ver - \t%llu\n", qp->rx_err_ver);
 502        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 503                               "rx_buff - \t0x%p\n", qp->rx_buff);
 504        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 505                               "rx_index - \t%u\n", qp->rx_index);
 506        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 507                               "rx_max_entry - \t%u\n", qp->rx_max_entry);
 508        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 509                               "rx_alloc_entry - \t%u\n\n", qp->rx_alloc_entry);
 510
 511        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 512                               "tx_bytes - \t%llu\n", qp->tx_bytes);
 513        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 514                               "tx_pkts - \t%llu\n", qp->tx_pkts);
 515        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 516                               "tx_memcpy - \t%llu\n", qp->tx_memcpy);
 517        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 518                               "tx_async - \t%llu\n", qp->tx_async);
 519        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 520                               "tx_ring_full - \t%llu\n", qp->tx_ring_full);
 521        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 522                               "tx_err_no_buf - %llu\n", qp->tx_err_no_buf);
 523        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 524                               "tx_mw - \t0x%p\n", qp->tx_mw);
 525        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 526                               "tx_index (H) - \t%u\n", qp->tx_index);
 527        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 528                               "RRI (T) - \t%u\n",
 529                               qp->remote_rx_info->entry);
 530        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 531                               "tx_max_entry - \t%u\n", qp->tx_max_entry);
 532        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 533                               "free tx - \t%u\n",
 534                               ntb_transport_tx_free_entry(qp));
 535
 536        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 537                               "\n");
 538        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 539                               "Using TX DMA - \t%s\n",
 540                               qp->tx_dma_chan ? "Yes" : "No");
 541        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 542                               "Using RX DMA - \t%s\n",
 543                               qp->rx_dma_chan ? "Yes" : "No");
 544        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 545                               "QP Link - \t%s\n",
 546                               qp->link_is_up ? "Up" : "Down");
 547        out_offset += snprintf(buf + out_offset, out_count - out_offset,
 548                               "\n");
 549
 550        if (out_offset > out_count)
 551                out_offset = out_count;
 552
 553        ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
 554        kfree(buf);
 555        return ret;
 556}
 557
 558static const struct file_operations ntb_qp_debugfs_stats = {
 559        .owner = THIS_MODULE,
 560        .open = simple_open,
 561        .read = debugfs_read,
 562};
 563
 564static void ntb_list_add(spinlock_t *lock, struct list_head *entry,
 565                         struct list_head *list)
 566{
 567        unsigned long flags;
 568
 569        spin_lock_irqsave(lock, flags);
 570        list_add_tail(entry, list);
 571        spin_unlock_irqrestore(lock, flags);
 572}
 573
 574static struct ntb_queue_entry *ntb_list_rm(spinlock_t *lock,
 575                                           struct list_head *list)
 576{
 577        struct ntb_queue_entry *entry;
 578        unsigned long flags;
 579
 580        spin_lock_irqsave(lock, flags);
 581        if (list_empty(list)) {
 582                entry = NULL;
 583                goto out;
 584        }
 585        entry = list_first_entry(list, struct ntb_queue_entry, entry);
 586        list_del(&entry->entry);
 587
 588out:
 589        spin_unlock_irqrestore(lock, flags);
 590
 591        return entry;
 592}
 593
 594static struct ntb_queue_entry *ntb_list_mv(spinlock_t *lock,
 595                                           struct list_head *list,
 596                                           struct list_head *to_list)
 597{
 598        struct ntb_queue_entry *entry;
 599        unsigned long flags;
 600
 601        spin_lock_irqsave(lock, flags);
 602
 603        if (list_empty(list)) {
 604                entry = NULL;
 605        } else {
 606                entry = list_first_entry(list, struct ntb_queue_entry, entry);
 607                list_move_tail(&entry->entry, to_list);
 608        }
 609
 610        spin_unlock_irqrestore(lock, flags);
 611
 612        return entry;
 613}
 614
 615static int ntb_transport_setup_qp_mw(struct ntb_transport_ctx *nt,
 616                                     unsigned int qp_num)
 617{
 618        struct ntb_transport_qp *qp = &nt->qp_vec[qp_num];
 619        struct ntb_transport_mw *mw;
 620        struct ntb_dev *ndev = nt->ndev;
 621        struct ntb_queue_entry *entry;
 622        unsigned int rx_size, num_qps_mw;
 623        unsigned int mw_num, mw_count, qp_count;
 624        unsigned int i;
 625        int node;
 626
 627        mw_count = nt->mw_count;
 628        qp_count = nt->qp_count;
 629
 630        mw_num = QP_TO_MW(nt, qp_num);
 631        mw = &nt->mw_vec[mw_num];
 632
 633        if (!mw->virt_addr)
 634                return -ENOMEM;
 635
 636        if (mw_num < qp_count % mw_count)
 637                num_qps_mw = qp_count / mw_count + 1;
 638        else
 639                num_qps_mw = qp_count / mw_count;
 640
 641        rx_size = (unsigned int)mw->xlat_size / num_qps_mw;
 642        qp->rx_buff = mw->virt_addr + rx_size * (qp_num / mw_count);
 643        rx_size -= sizeof(struct ntb_rx_info);
 644
 645        qp->remote_rx_info = qp->rx_buff + rx_size;
 646
 647        /* Due to housekeeping, there must be atleast 2 buffs */
 648        qp->rx_max_frame = min(transport_mtu, rx_size / 2);
 649        qp->rx_max_entry = rx_size / qp->rx_max_frame;
 650        qp->rx_index = 0;
 651
 652        /*
 653         * Checking to see if we have more entries than the default.
 654         * We should add additional entries if that is the case so we
 655         * can be in sync with the transport frames.
 656         */
 657        node = dev_to_node(&ndev->dev);
 658        for (i = qp->rx_alloc_entry; i < qp->rx_max_entry; i++) {
 659                entry = kzalloc_node(sizeof(*entry), GFP_KERNEL, node);
 660                if (!entry)
 661                        return -ENOMEM;
 662
 663                entry->qp = qp;
 664                ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry,
 665                             &qp->rx_free_q);
 666                qp->rx_alloc_entry++;
 667        }
 668
 669        qp->remote_rx_info->entry = qp->rx_max_entry - 1;
 670
 671        /* setup the hdr offsets with 0's */
 672        for (i = 0; i < qp->rx_max_entry; i++) {
 673                void *offset = (qp->rx_buff + qp->rx_max_frame * (i + 1) -
 674                                sizeof(struct ntb_payload_header));
 675                memset(offset, 0, sizeof(struct ntb_payload_header));
 676        }
 677
 678        qp->rx_pkts = 0;
 679        qp->tx_pkts = 0;
 680        qp->tx_index = 0;
 681
 682        return 0;
 683}
 684
 685static irqreturn_t ntb_transport_isr(int irq, void *dev)
 686{
 687        struct ntb_transport_qp *qp = dev;
 688
 689        tasklet_schedule(&qp->rxc_db_work);
 690
 691        return IRQ_HANDLED;
 692}
 693
 694static void ntb_transport_setup_qp_peer_msi(struct ntb_transport_ctx *nt,
 695                                            unsigned int qp_num)
 696{
 697        struct ntb_transport_qp *qp = &nt->qp_vec[qp_num];
 698        int spad = qp_num * 2 + nt->msi_spad_offset;
 699
 700        if (!nt->use_msi)
 701                return;
 702
 703        if (spad >= ntb_spad_count(nt->ndev))
 704                return;
 705
 706        qp->peer_msi_desc.addr_offset =
 707                ntb_peer_spad_read(qp->ndev, PIDX, spad);
 708        qp->peer_msi_desc.data =
 709                ntb_peer_spad_read(qp->ndev, PIDX, spad + 1);
 710
 711        dev_dbg(&qp->ndev->pdev->dev, "QP%d Peer MSI addr=%x data=%x\n",
 712                qp_num, qp->peer_msi_desc.addr_offset, qp->peer_msi_desc.data);
 713
 714        if (qp->peer_msi_desc.addr_offset) {
 715                qp->use_msi = true;
 716                dev_info(&qp->ndev->pdev->dev,
 717                         "Using MSI interrupts for QP%d\n", qp_num);
 718        }
 719}
 720
 721static void ntb_transport_setup_qp_msi(struct ntb_transport_ctx *nt,
 722                                       unsigned int qp_num)
 723{
 724        struct ntb_transport_qp *qp = &nt->qp_vec[qp_num];
 725        int spad = qp_num * 2 + nt->msi_spad_offset;
 726        int rc;
 727
 728        if (!nt->use_msi)
 729                return;
 730
 731        if (spad >= ntb_spad_count(nt->ndev)) {
 732                dev_warn_once(&qp->ndev->pdev->dev,
 733                              "Not enough SPADS to use MSI interrupts\n");
 734                return;
 735        }
 736
 737        ntb_spad_write(qp->ndev, spad, 0);
 738        ntb_spad_write(qp->ndev, spad + 1, 0);
 739
 740        if (!qp->msi_irq) {
 741                qp->msi_irq = ntbm_msi_request_irq(qp->ndev, ntb_transport_isr,
 742                                                   KBUILD_MODNAME, qp,
 743                                                   &qp->msi_desc);
 744                if (qp->msi_irq < 0) {
 745                        dev_warn(&qp->ndev->pdev->dev,
 746                                 "Unable to allocate MSI interrupt for qp%d\n",
 747                                 qp_num);
 748                        return;
 749                }
 750        }
 751
 752        rc = ntb_spad_write(qp->ndev, spad, qp->msi_desc.addr_offset);
 753        if (rc)
 754                goto err_free_interrupt;
 755
 756        rc = ntb_spad_write(qp->ndev, spad + 1, qp->msi_desc.data);
 757        if (rc)
 758                goto err_free_interrupt;
 759
 760        dev_dbg(&qp->ndev->pdev->dev, "QP%d MSI %d addr=%x data=%x\n",
 761                qp_num, qp->msi_irq, qp->msi_desc.addr_offset,
 762                qp->msi_desc.data);
 763
 764        return;
 765
 766err_free_interrupt:
 767        devm_free_irq(&nt->ndev->dev, qp->msi_irq, qp);
 768}
 769
 770static void ntb_transport_msi_peer_desc_changed(struct ntb_transport_ctx *nt)
 771{
 772        int i;
 773
 774        dev_dbg(&nt->ndev->pdev->dev, "Peer MSI descriptors changed");
 775
 776        for (i = 0; i < nt->qp_count; i++)
 777                ntb_transport_setup_qp_peer_msi(nt, i);
 778}
 779
 780static void ntb_transport_msi_desc_changed(void *data)
 781{
 782        struct ntb_transport_ctx *nt = data;
 783        int i;
 784
 785        dev_dbg(&nt->ndev->pdev->dev, "MSI descriptors changed");
 786
 787        for (i = 0; i < nt->qp_count; i++)
 788                ntb_transport_setup_qp_msi(nt, i);
 789
 790        ntb_peer_db_set(nt->ndev, nt->msi_db_mask);
 791}
 792
 793static void ntb_free_mw(struct ntb_transport_ctx *nt, int num_mw)
 794{
 795        struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
 796        struct pci_dev *pdev = nt->ndev->pdev;
 797
 798        if (!mw->virt_addr)
 799                return;
 800
 801        ntb_mw_clear_trans(nt->ndev, PIDX, num_mw);
 802        dma_free_coherent(&pdev->dev, mw->alloc_size,
 803                          mw->alloc_addr, mw->dma_addr);
 804        mw->xlat_size = 0;
 805        mw->buff_size = 0;
 806        mw->alloc_size = 0;
 807        mw->alloc_addr = NULL;
 808        mw->virt_addr = NULL;
 809}
 810
 811static int ntb_alloc_mw_buffer(struct ntb_transport_mw *mw,
 812                               struct device *dma_dev, size_t align)
 813{
 814        dma_addr_t dma_addr;
 815        void *alloc_addr, *virt_addr;
 816        int rc;
 817
 818        alloc_addr = dma_alloc_coherent(dma_dev, mw->alloc_size,
 819                                        &dma_addr, GFP_KERNEL);
 820        if (!alloc_addr) {
 821                dev_err(dma_dev, "Unable to alloc MW buff of size %zu\n",
 822                        mw->alloc_size);
 823                return -ENOMEM;
 824        }
 825        virt_addr = alloc_addr;
 826
 827        /*
 828         * we must ensure that the memory address allocated is BAR size
 829         * aligned in order for the XLAT register to take the value. This
 830         * is a requirement of the hardware. It is recommended to setup CMA
 831         * for BAR sizes equal or greater than 4MB.
 832         */
 833        if (!IS_ALIGNED(dma_addr, align)) {
 834                if (mw->alloc_size > mw->buff_size) {
 835                        virt_addr = PTR_ALIGN(alloc_addr, align);
 836                        dma_addr = ALIGN(dma_addr, align);
 837                } else {
 838                        rc = -ENOMEM;
 839                        goto err;
 840                }
 841        }
 842
 843        mw->alloc_addr = alloc_addr;
 844        mw->virt_addr = virt_addr;
 845        mw->dma_addr = dma_addr;
 846
 847        return 0;
 848
 849err:
 850        dma_free_coherent(dma_dev, mw->alloc_size, alloc_addr, dma_addr);
 851
 852        return rc;
 853}
 854
 855static int ntb_set_mw(struct ntb_transport_ctx *nt, int num_mw,
 856                      resource_size_t size)
 857{
 858        struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
 859        struct pci_dev *pdev = nt->ndev->pdev;
 860        size_t xlat_size, buff_size;
 861        resource_size_t xlat_align;
 862        resource_size_t xlat_align_size;
 863        int rc;
 864
 865        if (!size)
 866                return -EINVAL;
 867
 868        rc = ntb_mw_get_align(nt->ndev, PIDX, num_mw, &xlat_align,
 869                              &xlat_align_size, NULL);
 870        if (rc)
 871                return rc;
 872
 873        xlat_size = round_up(size, xlat_align_size);
 874        buff_size = round_up(size, xlat_align);
 875
 876        /* No need to re-setup */
 877        if (mw->xlat_size == xlat_size)
 878                return 0;
 879
 880        if (mw->buff_size)
 881                ntb_free_mw(nt, num_mw);
 882
 883        /* Alloc memory for receiving data.  Must be aligned */
 884        mw->xlat_size = xlat_size;
 885        mw->buff_size = buff_size;
 886        mw->alloc_size = buff_size;
 887
 888        rc = ntb_alloc_mw_buffer(mw, &pdev->dev, xlat_align);
 889        if (rc) {
 890                mw->alloc_size *= 2;
 891                rc = ntb_alloc_mw_buffer(mw, &pdev->dev, xlat_align);
 892                if (rc) {
 893                        dev_err(&pdev->dev,
 894                                "Unable to alloc aligned MW buff\n");
 895                        mw->xlat_size = 0;
 896                        mw->buff_size = 0;
 897                        mw->alloc_size = 0;
 898                        return rc;
 899                }
 900        }
 901
 902        /* Notify HW the memory location of the receive buffer */
 903        rc = ntb_mw_set_trans(nt->ndev, PIDX, num_mw, mw->dma_addr,
 904                              mw->xlat_size);
 905        if (rc) {
 906                dev_err(&pdev->dev, "Unable to set mw%d translation", num_mw);
 907                ntb_free_mw(nt, num_mw);
 908                return -EIO;
 909        }
 910
 911        return 0;
 912}
 913
 914static void ntb_qp_link_down_reset(struct ntb_transport_qp *qp)
 915{
 916        qp->link_is_up = false;
 917        qp->active = false;
 918
 919        qp->tx_index = 0;
 920        qp->rx_index = 0;
 921        qp->rx_bytes = 0;
 922        qp->rx_pkts = 0;
 923        qp->rx_ring_empty = 0;
 924        qp->rx_err_no_buf = 0;
 925        qp->rx_err_oflow = 0;
 926        qp->rx_err_ver = 0;
 927        qp->rx_memcpy = 0;
 928        qp->rx_async = 0;
 929        qp->tx_bytes = 0;
 930        qp->tx_pkts = 0;
 931        qp->tx_ring_full = 0;
 932        qp->tx_err_no_buf = 0;
 933        qp->tx_memcpy = 0;
 934        qp->tx_async = 0;
 935}
 936
 937static void ntb_qp_link_cleanup(struct ntb_transport_qp *qp)
 938{
 939        struct ntb_transport_ctx *nt = qp->transport;
 940        struct pci_dev *pdev = nt->ndev->pdev;
 941
 942        dev_info(&pdev->dev, "qp %d: Link Cleanup\n", qp->qp_num);
 943
 944        cancel_delayed_work_sync(&qp->link_work);
 945        ntb_qp_link_down_reset(qp);
 946
 947        if (qp->event_handler)
 948                qp->event_handler(qp->cb_data, qp->link_is_up);
 949}
 950
 951static void ntb_qp_link_cleanup_work(struct work_struct *work)
 952{
 953        struct ntb_transport_qp *qp = container_of(work,
 954                                                   struct ntb_transport_qp,
 955                                                   link_cleanup);
 956        struct ntb_transport_ctx *nt = qp->transport;
 957
 958        ntb_qp_link_cleanup(qp);
 959
 960        if (nt->link_is_up)
 961                schedule_delayed_work(&qp->link_work,
 962                                      msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 963}
 964
 965static void ntb_qp_link_down(struct ntb_transport_qp *qp)
 966{
 967        schedule_work(&qp->link_cleanup);
 968}
 969
 970static void ntb_transport_link_cleanup(struct ntb_transport_ctx *nt)
 971{
 972        struct ntb_transport_qp *qp;
 973        u64 qp_bitmap_alloc;
 974        unsigned int i, count;
 975
 976        qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
 977
 978        /* Pass along the info to any clients */
 979        for (i = 0; i < nt->qp_count; i++)
 980                if (qp_bitmap_alloc & BIT_ULL(i)) {
 981                        qp = &nt->qp_vec[i];
 982                        ntb_qp_link_cleanup(qp);
 983                        cancel_work_sync(&qp->link_cleanup);
 984                        cancel_delayed_work_sync(&qp->link_work);
 985                }
 986
 987        if (!nt->link_is_up)
 988                cancel_delayed_work_sync(&nt->link_work);
 989
 990        for (i = 0; i < nt->mw_count; i++)
 991                ntb_free_mw(nt, i);
 992
 993        /* The scratchpad registers keep the values if the remote side
 994         * goes down, blast them now to give them a sane value the next
 995         * time they are accessed
 996         */
 997        count = ntb_spad_count(nt->ndev);
 998        for (i = 0; i < count; i++)
 999                ntb_spad_write(nt->ndev, i, 0);
1000}
1001
1002static void ntb_transport_link_cleanup_work(struct work_struct *work)
1003{
1004        struct ntb_transport_ctx *nt =
1005                container_of(work, struct ntb_transport_ctx, link_cleanup);
1006
1007        ntb_transport_link_cleanup(nt);
1008}
1009
1010static void ntb_transport_event_callback(void *data)
1011{
1012        struct ntb_transport_ctx *nt = data;
1013
1014        if (ntb_link_is_up(nt->ndev, NULL, NULL) == 1)
1015                schedule_delayed_work(&nt->link_work, 0);
1016        else
1017                schedule_work(&nt->link_cleanup);
1018}
1019
1020static void ntb_transport_link_work(struct work_struct *work)
1021{
1022        struct ntb_transport_ctx *nt =
1023                container_of(work, struct ntb_transport_ctx, link_work.work);
1024        struct ntb_dev *ndev = nt->ndev;
1025        struct pci_dev *pdev = ndev->pdev;
1026        resource_size_t size;
1027        u32 val;
1028        int rc = 0, i, spad;
1029
1030        /* send the local info, in the opposite order of the way we read it */
1031
1032        if (nt->use_msi) {
1033                rc = ntb_msi_setup_mws(ndev);
1034                if (rc) {
1035                        dev_warn(&pdev->dev,
1036                                 "Failed to register MSI memory window: %d\n",
1037                                 rc);
1038                        nt->use_msi = false;
1039                }
1040        }
1041
1042        for (i = 0; i < nt->qp_count; i++)
1043                ntb_transport_setup_qp_msi(nt, i);
1044
1045        for (i = 0; i < nt->mw_count; i++) {
1046                size = nt->mw_vec[i].phys_size;
1047
1048                if (max_mw_size && size > max_mw_size)
1049                        size = max_mw_size;
1050
1051                spad = MW0_SZ_HIGH + (i * 2);
1052                ntb_peer_spad_write(ndev, PIDX, spad, upper_32_bits(size));
1053
1054                spad = MW0_SZ_LOW + (i * 2);
1055                ntb_peer_spad_write(ndev, PIDX, spad, lower_32_bits(size));
1056        }
1057
1058        ntb_peer_spad_write(ndev, PIDX, NUM_MWS, nt->mw_count);
1059
1060        ntb_peer_spad_write(ndev, PIDX, NUM_QPS, nt->qp_count);
1061
1062        ntb_peer_spad_write(ndev, PIDX, VERSION, NTB_TRANSPORT_VERSION);
1063
1064        /* Query the remote side for its info */
1065        val = ntb_spad_read(ndev, VERSION);
1066        dev_dbg(&pdev->dev, "Remote version = %d\n", val);
1067        if (val != NTB_TRANSPORT_VERSION)
1068                goto out;
1069
1070        val = ntb_spad_read(ndev, NUM_QPS);
1071        dev_dbg(&pdev->dev, "Remote max number of qps = %d\n", val);
1072        if (val != nt->qp_count)
1073                goto out;
1074
1075        val = ntb_spad_read(ndev, NUM_MWS);
1076        dev_dbg(&pdev->dev, "Remote number of mws = %d\n", val);
1077        if (val != nt->mw_count)
1078                goto out;
1079
1080        for (i = 0; i < nt->mw_count; i++) {
1081                u64 val64;
1082
1083                val = ntb_spad_read(ndev, MW0_SZ_HIGH + (i * 2));
1084                val64 = (u64)val << 32;
1085
1086                val = ntb_spad_read(ndev, MW0_SZ_LOW + (i * 2));
1087                val64 |= val;
1088
1089                dev_dbg(&pdev->dev, "Remote MW%d size = %#llx\n", i, val64);
1090
1091                rc = ntb_set_mw(nt, i, val64);
1092                if (rc)
1093                        goto out1;
1094        }
1095
1096        nt->link_is_up = true;
1097
1098        for (i = 0; i < nt->qp_count; i++) {
1099                struct ntb_transport_qp *qp = &nt->qp_vec[i];
1100
1101                ntb_transport_setup_qp_mw(nt, i);
1102                ntb_transport_setup_qp_peer_msi(nt, i);
1103
1104                if (qp->client_ready)
1105                        schedule_delayed_work(&qp->link_work, 0);
1106        }
1107
1108        return;
1109
1110out1:
1111        for (i = 0; i < nt->mw_count; i++)
1112                ntb_free_mw(nt, i);
1113
1114        /* if there's an actual failure, we should just bail */
1115        if (rc < 0)
1116                return;
1117
1118out:
1119        if (ntb_link_is_up(ndev, NULL, NULL) == 1)
1120                schedule_delayed_work(&nt->link_work,
1121                                      msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
1122}
1123
1124static void ntb_qp_link_work(struct work_struct *work)
1125{
1126        struct ntb_transport_qp *qp = container_of(work,
1127                                                   struct ntb_transport_qp,
1128                                                   link_work.work);
1129        struct pci_dev *pdev = qp->ndev->pdev;
1130        struct ntb_transport_ctx *nt = qp->transport;
1131        int val;
1132
1133        WARN_ON(!nt->link_is_up);
1134
1135        val = ntb_spad_read(nt->ndev, QP_LINKS);
1136
1137        ntb_peer_spad_write(nt->ndev, PIDX, QP_LINKS, val | BIT(qp->qp_num));
1138
1139        /* query remote spad for qp ready bits */
1140        dev_dbg_ratelimited(&pdev->dev, "Remote QP link status = %x\n", val);
1141
1142        /* See if the remote side is up */
1143        if (val & BIT(qp->qp_num)) {
1144                dev_info(&pdev->dev, "qp %d: Link Up\n", qp->qp_num);
1145                qp->link_is_up = true;
1146                qp->active = true;
1147
1148                if (qp->event_handler)
1149                        qp->event_handler(qp->cb_data, qp->link_is_up);
1150
1151                if (qp->active)
1152                        tasklet_schedule(&qp->rxc_db_work);
1153        } else if (nt->link_is_up)
1154                schedule_delayed_work(&qp->link_work,
1155                                      msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
1156}
1157
1158static int ntb_transport_init_queue(struct ntb_transport_ctx *nt,
1159                                    unsigned int qp_num)
1160{
1161        struct ntb_transport_qp *qp;
1162        phys_addr_t mw_base;
1163        resource_size_t mw_size;
1164        unsigned int num_qps_mw, tx_size;
1165        unsigned int mw_num, mw_count, qp_count;
1166        u64 qp_offset;
1167
1168        mw_count = nt->mw_count;
1169        qp_count = nt->qp_count;
1170
1171        mw_num = QP_TO_MW(nt, qp_num);
1172
1173        qp = &nt->qp_vec[qp_num];
1174        qp->qp_num = qp_num;
1175        qp->transport = nt;
1176        qp->ndev = nt->ndev;
1177        qp->client_ready = false;
1178        qp->event_handler = NULL;
1179        ntb_qp_link_down_reset(qp);
1180
1181        if (mw_num < qp_count % mw_count)
1182                num_qps_mw = qp_count / mw_count + 1;
1183        else
1184                num_qps_mw = qp_count / mw_count;
1185
1186        mw_base = nt->mw_vec[mw_num].phys_addr;
1187        mw_size = nt->mw_vec[mw_num].phys_size;
1188
1189        if (max_mw_size && mw_size > max_mw_size)
1190                mw_size = max_mw_size;
1191
1192        tx_size = (unsigned int)mw_size / num_qps_mw;
1193        qp_offset = tx_size * (qp_num / mw_count);
1194
1195        qp->tx_mw_size = tx_size;
1196        qp->tx_mw = nt->mw_vec[mw_num].vbase + qp_offset;
1197        if (!qp->tx_mw)
1198                return -EINVAL;
1199
1200        qp->tx_mw_phys = mw_base + qp_offset;
1201        if (!qp->tx_mw_phys)
1202                return -EINVAL;
1203
1204        tx_size -= sizeof(struct ntb_rx_info);
1205        qp->rx_info = qp->tx_mw + tx_size;
1206
1207        /* Due to housekeeping, there must be atleast 2 buffs */
1208        qp->tx_max_frame = min(transport_mtu, tx_size / 2);
1209        qp->tx_max_entry = tx_size / qp->tx_max_frame;
1210
1211        if (nt->debugfs_node_dir) {
1212                char debugfs_name[4];
1213
1214                snprintf(debugfs_name, 4, "qp%d", qp_num);
1215                qp->debugfs_dir = debugfs_create_dir(debugfs_name,
1216                                                     nt->debugfs_node_dir);
1217
1218                qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR,
1219                                                        qp->debugfs_dir, qp,
1220                                                        &ntb_qp_debugfs_stats);
1221        } else {
1222                qp->debugfs_dir = NULL;
1223                qp->debugfs_stats = NULL;
1224        }
1225
1226        INIT_DELAYED_WORK(&qp->link_work, ntb_qp_link_work);
1227        INIT_WORK(&qp->link_cleanup, ntb_qp_link_cleanup_work);
1228
1229        spin_lock_init(&qp->ntb_rx_q_lock);
1230        spin_lock_init(&qp->ntb_tx_free_q_lock);
1231
1232        INIT_LIST_HEAD(&qp->rx_post_q);
1233        INIT_LIST_HEAD(&qp->rx_pend_q);
1234        INIT_LIST_HEAD(&qp->rx_free_q);
1235        INIT_LIST_HEAD(&qp->tx_free_q);
1236
1237        tasklet_init(&qp->rxc_db_work, ntb_transport_rxc_db,
1238                     (unsigned long)qp);
1239
1240        return 0;
1241}
1242
1243static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev)
1244{
1245        struct ntb_transport_ctx *nt;
1246        struct ntb_transport_mw *mw;
1247        unsigned int mw_count, qp_count, spad_count, max_mw_count_for_spads;
1248        u64 qp_bitmap;
1249        int node;
1250        int rc, i;
1251
1252        mw_count = ntb_peer_mw_count(ndev);
1253
1254        if (!ndev->ops->mw_set_trans) {
1255                dev_err(&ndev->dev, "Inbound MW based NTB API is required\n");
1256                return -EINVAL;
1257        }
1258
1259        if (ntb_db_is_unsafe(ndev))
1260                dev_dbg(&ndev->dev,
1261                        "doorbell is unsafe, proceed anyway...\n");
1262        if (ntb_spad_is_unsafe(ndev))
1263                dev_dbg(&ndev->dev,
1264                        "scratchpad is unsafe, proceed anyway...\n");
1265
1266        if (ntb_peer_port_count(ndev) != NTB_DEF_PEER_CNT)
1267                dev_warn(&ndev->dev, "Multi-port NTB devices unsupported\n");
1268
1269        node = dev_to_node(&ndev->dev);
1270
1271        nt = kzalloc_node(sizeof(*nt), GFP_KERNEL, node);
1272        if (!nt)
1273                return -ENOMEM;
1274
1275        nt->ndev = ndev;
1276
1277        /*
1278         * If we are using MSI, and have at least one extra memory window,
1279         * we will reserve the last MW for the MSI window.
1280         */
1281        if (use_msi && mw_count > 1) {
1282                rc = ntb_msi_init(ndev, ntb_transport_msi_desc_changed);
1283                if (!rc) {
1284                        mw_count -= 1;
1285                        nt->use_msi = true;
1286                }
1287        }
1288
1289        spad_count = ntb_spad_count(ndev);
1290
1291        /* Limit the MW's based on the availability of scratchpads */
1292
1293        if (spad_count < NTB_TRANSPORT_MIN_SPADS) {
1294                nt->mw_count = 0;
1295                rc = -EINVAL;
1296                goto err;
1297        }
1298
1299        max_mw_count_for_spads = (spad_count - MW0_SZ_HIGH) / 2;
1300        nt->mw_count = min(mw_count, max_mw_count_for_spads);
1301
1302        nt->msi_spad_offset = nt->mw_count * 2 + MW0_SZ_HIGH;
1303
1304        nt->mw_vec = kcalloc_node(mw_count, sizeof(*nt->mw_vec),
1305                                  GFP_KERNEL, node);
1306        if (!nt->mw_vec) {
1307                rc = -ENOMEM;
1308                goto err;
1309        }
1310
1311        for (i = 0; i < mw_count; i++) {
1312                mw = &nt->mw_vec[i];
1313
1314                rc = ntb_peer_mw_get_addr(ndev, i, &mw->phys_addr,
1315                                          &mw->phys_size);
1316                if (rc)
1317                        goto err1;
1318
1319                mw->vbase = ioremap_wc(mw->phys_addr, mw->phys_size);
1320                if (!mw->vbase) {
1321                        rc = -ENOMEM;
1322                        goto err1;
1323                }
1324
1325                mw->buff_size = 0;
1326                mw->xlat_size = 0;
1327                mw->virt_addr = NULL;
1328                mw->dma_addr = 0;
1329        }
1330
1331        qp_bitmap = ntb_db_valid_mask(ndev);
1332
1333        qp_count = ilog2(qp_bitmap);
1334        if (nt->use_msi) {
1335                qp_count -= 1;
1336                nt->msi_db_mask = 1 << qp_count;
1337                ntb_db_clear_mask(ndev, nt->msi_db_mask);
1338        }
1339
1340        if (max_num_clients && max_num_clients < qp_count)
1341                qp_count = max_num_clients;
1342        else if (nt->mw_count < qp_count)
1343                qp_count = nt->mw_count;
1344
1345        qp_bitmap &= BIT_ULL(qp_count) - 1;
1346
1347        nt->qp_count = qp_count;
1348        nt->qp_bitmap = qp_bitmap;
1349        nt->qp_bitmap_free = qp_bitmap;
1350
1351        nt->qp_vec = kcalloc_node(qp_count, sizeof(*nt->qp_vec),
1352                                  GFP_KERNEL, node);
1353        if (!nt->qp_vec) {
1354                rc = -ENOMEM;
1355                goto err1;
1356        }
1357
1358        if (nt_debugfs_dir) {
1359                nt->debugfs_node_dir =
1360                        debugfs_create_dir(pci_name(ndev->pdev),
1361                                           nt_debugfs_dir);
1362        }
1363
1364        for (i = 0; i < qp_count; i++) {
1365                rc = ntb_transport_init_queue(nt, i);
1366                if (rc)
1367                        goto err2;
1368        }
1369
1370        INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work);
1371        INIT_WORK(&nt->link_cleanup, ntb_transport_link_cleanup_work);
1372
1373        rc = ntb_set_ctx(ndev, nt, &ntb_transport_ops);
1374        if (rc)
1375                goto err2;
1376
1377        INIT_LIST_HEAD(&nt->client_devs);
1378        rc = ntb_bus_init(nt);
1379        if (rc)
1380                goto err3;
1381
1382        nt->link_is_up = false;
1383        ntb_link_enable(ndev, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
1384        ntb_link_event(ndev);
1385
1386        return 0;
1387
1388err3:
1389        ntb_clear_ctx(ndev);
1390err2:
1391        kfree(nt->qp_vec);
1392err1:
1393        while (i--) {
1394                mw = &nt->mw_vec[i];
1395                iounmap(mw->vbase);
1396        }
1397        kfree(nt->mw_vec);
1398err:
1399        kfree(nt);
1400        return rc;
1401}
1402
1403static void ntb_transport_free(struct ntb_client *self, struct ntb_dev *ndev)
1404{
1405        struct ntb_transport_ctx *nt = ndev->ctx;
1406        struct ntb_transport_qp *qp;
1407        u64 qp_bitmap_alloc;
1408        int i;
1409
1410        ntb_transport_link_cleanup(nt);
1411        cancel_work_sync(&nt->link_cleanup);
1412        cancel_delayed_work_sync(&nt->link_work);
1413
1414        qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
1415
1416        /* verify that all the qp's are freed */
1417        for (i = 0; i < nt->qp_count; i++) {
1418                qp = &nt->qp_vec[i];
1419                if (qp_bitmap_alloc & BIT_ULL(i))
1420                        ntb_transport_free_queue(qp);
1421                debugfs_remove_recursive(qp->debugfs_dir);
1422        }
1423
1424        ntb_link_disable(ndev);
1425        ntb_clear_ctx(ndev);
1426
1427        ntb_bus_remove(nt);
1428
1429        for (i = nt->mw_count; i--; ) {
1430                ntb_free_mw(nt, i);
1431                iounmap(nt->mw_vec[i].vbase);
1432        }
1433
1434        kfree(nt->qp_vec);
1435        kfree(nt->mw_vec);
1436        kfree(nt);
1437}
1438
1439static void ntb_complete_rxc(struct ntb_transport_qp *qp)
1440{
1441        struct ntb_queue_entry *entry;
1442        void *cb_data;
1443        unsigned int len;
1444        unsigned long irqflags;
1445
1446        spin_lock_irqsave(&qp->ntb_rx_q_lock, irqflags);
1447
1448        while (!list_empty(&qp->rx_post_q)) {
1449                entry = list_first_entry(&qp->rx_post_q,
1450                                         struct ntb_queue_entry, entry);
1451                if (!(entry->flags & DESC_DONE_FLAG))
1452                        break;
1453
1454                entry->rx_hdr->flags = 0;
1455                iowrite32(entry->rx_index, &qp->rx_info->entry);
1456
1457                cb_data = entry->cb_data;
1458                len = entry->len;
1459
1460                list_move_tail(&entry->entry, &qp->rx_free_q);
1461
1462                spin_unlock_irqrestore(&qp->ntb_rx_q_lock, irqflags);
1463
1464                if (qp->rx_handler && qp->client_ready)
1465                        qp->rx_handler(qp, qp->cb_data, cb_data, len);
1466
1467                spin_lock_irqsave(&qp->ntb_rx_q_lock, irqflags);
1468        }
1469
1470        spin_unlock_irqrestore(&qp->ntb_rx_q_lock, irqflags);
1471}
1472
1473static void ntb_rx_copy_callback(void *data,
1474                                 const struct dmaengine_result *res)
1475{
1476        struct ntb_queue_entry *entry = data;
1477
1478        /* we need to check DMA results if we are using DMA */
1479        if (res) {
1480                enum dmaengine_tx_result dma_err = res->result;
1481
1482                switch (dma_err) {
1483                case DMA_TRANS_READ_FAILED:
1484                case DMA_TRANS_WRITE_FAILED:
1485                        entry->errors++;
1486                        /* fall through */
1487                case DMA_TRANS_ABORTED:
1488                {
1489                        struct ntb_transport_qp *qp = entry->qp;
1490                        void *offset = qp->rx_buff + qp->rx_max_frame *
1491                                        qp->rx_index;
1492
1493                        ntb_memcpy_rx(entry, offset);
1494                        qp->rx_memcpy++;
1495                        return;
1496                }
1497
1498                case DMA_TRANS_NOERROR:
1499                default:
1500                        break;
1501                }
1502        }
1503
1504        entry->flags |= DESC_DONE_FLAG;
1505
1506        ntb_complete_rxc(entry->qp);
1507}
1508
1509static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void *offset)
1510{
1511        void *buf = entry->buf;
1512        size_t len = entry->len;
1513
1514        memcpy(buf, offset, len);
1515
1516        /* Ensure that the data is fully copied out before clearing the flag */
1517        wmb();
1518
1519        ntb_rx_copy_callback(entry, NULL);
1520}
1521
1522static int ntb_async_rx_submit(struct ntb_queue_entry *entry, void *offset)
1523{
1524        struct dma_async_tx_descriptor *txd;
1525        struct ntb_transport_qp *qp = entry->qp;
1526        struct dma_chan *chan = qp->rx_dma_chan;
1527        struct dma_device *device;
1528        size_t pay_off, buff_off, len;
1529        struct dmaengine_unmap_data *unmap;
1530        dma_cookie_t cookie;
1531        void *buf = entry->buf;
1532
1533        len = entry->len;
1534        device = chan->device;
1535        pay_off = (size_t)offset & ~PAGE_MASK;
1536        buff_off = (size_t)buf & ~PAGE_MASK;
1537
1538        if (!is_dma_copy_aligned(device, pay_off, buff_off, len))
1539                goto err;
1540
1541        unmap = dmaengine_get_unmap_data(device->dev, 2, GFP_NOWAIT);
1542        if (!unmap)
1543                goto err;
1544
1545        unmap->len = len;
1546        unmap->addr[0] = dma_map_page(device->dev, virt_to_page(offset),
1547                                      pay_off, len, DMA_TO_DEVICE);
1548        if (dma_mapping_error(device->dev, unmap->addr[0]))
1549                goto err_get_unmap;
1550
1551        unmap->to_cnt = 1;
1552
1553        unmap->addr[1] = dma_map_page(device->dev, virt_to_page(buf),
1554                                      buff_off, len, DMA_FROM_DEVICE);
1555        if (dma_mapping_error(device->dev, unmap->addr[1]))
1556                goto err_get_unmap;
1557
1558        unmap->from_cnt = 1;
1559
1560        txd = device->device_prep_dma_memcpy(chan, unmap->addr[1],
1561                                             unmap->addr[0], len,
1562                                             DMA_PREP_INTERRUPT);
1563        if (!txd)
1564                goto err_get_unmap;
1565
1566        txd->callback_result = ntb_rx_copy_callback;
1567        txd->callback_param = entry;
1568        dma_set_unmap(txd, unmap);
1569
1570        cookie = dmaengine_submit(txd);
1571        if (dma_submit_error(cookie))
1572                goto err_set_unmap;
1573
1574        dmaengine_unmap_put(unmap);
1575
1576        qp->last_cookie = cookie;
1577
1578        qp->rx_async++;
1579
1580        return 0;
1581
1582err_set_unmap:
1583        dmaengine_unmap_put(unmap);
1584err_get_unmap:
1585        dmaengine_unmap_put(unmap);
1586err:
1587        return -ENXIO;
1588}
1589
1590static void ntb_async_rx(struct ntb_queue_entry *entry, void *offset)
1591{
1592        struct ntb_transport_qp *qp = entry->qp;
1593        struct dma_chan *chan = qp->rx_dma_chan;
1594        int res;
1595
1596        if (!chan)
1597                goto err;
1598
1599        if (entry->len < copy_bytes)
1600                goto err;
1601
1602        res = ntb_async_rx_submit(entry, offset);
1603        if (res < 0)
1604                goto err;
1605
1606        if (!entry->retries)
1607                qp->rx_async++;
1608
1609        return;
1610
1611err:
1612        ntb_memcpy_rx(entry, offset);
1613        qp->rx_memcpy++;
1614}
1615
1616static int ntb_process_rxc(struct ntb_transport_qp *qp)
1617{
1618        struct ntb_payload_header *hdr;
1619        struct ntb_queue_entry *entry;
1620        void *offset;
1621
1622        offset = qp->rx_buff + qp->rx_max_frame * qp->rx_index;
1623        hdr = offset + qp->rx_max_frame - sizeof(struct ntb_payload_header);
1624
1625        dev_dbg(&qp->ndev->pdev->dev, "qp %d: RX ver %u len %d flags %x\n",
1626                qp->qp_num, hdr->ver, hdr->len, hdr->flags);
1627
1628        if (!(hdr->flags & DESC_DONE_FLAG)) {
1629                dev_dbg(&qp->ndev->pdev->dev, "done flag not set\n");
1630                qp->rx_ring_empty++;
1631                return -EAGAIN;
1632        }
1633
1634        if (hdr->flags & LINK_DOWN_FLAG) {
1635                dev_dbg(&qp->ndev->pdev->dev, "link down flag set\n");
1636                ntb_qp_link_down(qp);
1637                hdr->flags = 0;
1638                return -EAGAIN;
1639        }
1640
1641        if (hdr->ver != (u32)qp->rx_pkts) {
1642                dev_dbg(&qp->ndev->pdev->dev,
1643                        "version mismatch, expected %llu - got %u\n",
1644                        qp->rx_pkts, hdr->ver);
1645                qp->rx_err_ver++;
1646                return -EIO;
1647        }
1648
1649        entry = ntb_list_mv(&qp->ntb_rx_q_lock, &qp->rx_pend_q, &qp->rx_post_q);
1650        if (!entry) {
1651                dev_dbg(&qp->ndev->pdev->dev, "no receive buffer\n");
1652                qp->rx_err_no_buf++;
1653                return -EAGAIN;
1654        }
1655
1656        entry->rx_hdr = hdr;
1657        entry->rx_index = qp->rx_index;
1658
1659        if (hdr->len > entry->len) {
1660                dev_dbg(&qp->ndev->pdev->dev,
1661                        "receive buffer overflow! Wanted %d got %d\n",
1662                        hdr->len, entry->len);
1663                qp->rx_err_oflow++;
1664
1665                entry->len = -EIO;
1666                entry->flags |= DESC_DONE_FLAG;
1667
1668                ntb_complete_rxc(qp);
1669        } else {
1670                dev_dbg(&qp->ndev->pdev->dev,
1671                        "RX OK index %u ver %u size %d into buf size %d\n",
1672                        qp->rx_index, hdr->ver, hdr->len, entry->len);
1673
1674                qp->rx_bytes += hdr->len;
1675                qp->rx_pkts++;
1676
1677                entry->len = hdr->len;
1678
1679                ntb_async_rx(entry, offset);
1680        }
1681
1682        qp->rx_index++;
1683        qp->rx_index %= qp->rx_max_entry;
1684
1685        return 0;
1686}
1687
1688static void ntb_transport_rxc_db(unsigned long data)
1689{
1690        struct ntb_transport_qp *qp = (void *)data;
1691        int rc, i;
1692
1693        dev_dbg(&qp->ndev->pdev->dev, "%s: doorbell %d received\n",
1694                __func__, qp->qp_num);
1695
1696        /* Limit the number of packets processed in a single interrupt to
1697         * provide fairness to others
1698         */
1699        for (i = 0; i < qp->rx_max_entry; i++) {
1700                rc = ntb_process_rxc(qp);
1701                if (rc)
1702                        break;
1703        }
1704
1705        if (i && qp->rx_dma_chan)
1706                dma_async_issue_pending(qp->rx_dma_chan);
1707
1708        if (i == qp->rx_max_entry) {
1709                /* there is more work to do */
1710                if (qp->active)
1711                        tasklet_schedule(&qp->rxc_db_work);
1712        } else if (ntb_db_read(qp->ndev) & BIT_ULL(qp->qp_num)) {
1713                /* the doorbell bit is set: clear it */
1714                ntb_db_clear(qp->ndev, BIT_ULL(qp->qp_num));
1715                /* ntb_db_read ensures ntb_db_clear write is committed */
1716                ntb_db_read(qp->ndev);
1717
1718                /* an interrupt may have arrived between finishing
1719                 * ntb_process_rxc and clearing the doorbell bit:
1720                 * there might be some more work to do.
1721                 */
1722                if (qp->active)
1723                        tasklet_schedule(&qp->rxc_db_work);
1724        }
1725}
1726
1727static void ntb_tx_copy_callback(void *data,
1728                                 const struct dmaengine_result *res)
1729{
1730        struct ntb_queue_entry *entry = data;
1731        struct ntb_transport_qp *qp = entry->qp;
1732        struct ntb_payload_header __iomem *hdr = entry->tx_hdr;
1733
1734        /* we need to check DMA results if we are using DMA */
1735        if (res) {
1736                enum dmaengine_tx_result dma_err = res->result;
1737
1738                switch (dma_err) {
1739                case DMA_TRANS_READ_FAILED:
1740                case DMA_TRANS_WRITE_FAILED:
1741                        entry->errors++;
1742                        /* fall through */
1743                case DMA_TRANS_ABORTED:
1744                {
1745                        void __iomem *offset =
1746                                qp->tx_mw + qp->tx_max_frame *
1747                                entry->tx_index;
1748
1749                        /* resubmit via CPU */
1750                        ntb_memcpy_tx(entry, offset);
1751                        qp->tx_memcpy++;
1752                        return;
1753                }
1754
1755                case DMA_TRANS_NOERROR:
1756                default:
1757                        break;
1758                }
1759        }
1760
1761        iowrite32(entry->flags | DESC_DONE_FLAG, &hdr->flags);
1762
1763        if (qp->use_msi)
1764                ntb_msi_peer_trigger(qp->ndev, PIDX, &qp->peer_msi_desc);
1765        else
1766                ntb_peer_db_set(qp->ndev, BIT_ULL(qp->qp_num));
1767
1768        /* The entry length can only be zero if the packet is intended to be a
1769         * "link down" or similar.  Since no payload is being sent in these
1770         * cases, there is nothing to add to the completion queue.
1771         */
1772        if (entry->len > 0) {
1773                qp->tx_bytes += entry->len;
1774
1775                if (qp->tx_handler)
1776                        qp->tx_handler(qp, qp->cb_data, entry->cb_data,
1777                                       entry->len);
1778        }
1779
1780        ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q);
1781}
1782
1783static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset)
1784{
1785#ifdef ARCH_HAS_NOCACHE_UACCESS
1786        /*
1787         * Using non-temporal mov to improve performance on non-cached
1788         * writes, even though we aren't actually copying from user space.
1789         */
1790        __copy_from_user_inatomic_nocache(offset, entry->buf, entry->len);
1791#else
1792        memcpy_toio(offset, entry->buf, entry->len);
1793#endif
1794
1795        /* Ensure that the data is fully copied out before setting the flags */
1796        wmb();
1797
1798        ntb_tx_copy_callback(entry, NULL);
1799}
1800
1801static int ntb_async_tx_submit(struct ntb_transport_qp *qp,
1802                               struct ntb_queue_entry *entry)
1803{
1804        struct dma_async_tx_descriptor *txd;
1805        struct dma_chan *chan = qp->tx_dma_chan;
1806        struct dma_device *device;
1807        size_t len = entry->len;
1808        void *buf = entry->buf;
1809        size_t dest_off, buff_off;
1810        struct dmaengine_unmap_data *unmap;
1811        dma_addr_t dest;
1812        dma_cookie_t cookie;
1813
1814        device = chan->device;
1815        dest = qp->tx_mw_dma_addr + qp->tx_max_frame * entry->tx_index;
1816        buff_off = (size_t)buf & ~PAGE_MASK;
1817        dest_off = (size_t)dest & ~PAGE_MASK;
1818
1819        if (!is_dma_copy_aligned(device, buff_off, dest_off, len))
1820                goto err;
1821
1822        unmap = dmaengine_get_unmap_data(device->dev, 1, GFP_NOWAIT);
1823        if (!unmap)
1824                goto err;
1825
1826        unmap->len = len;
1827        unmap->addr[0] = dma_map_page(device->dev, virt_to_page(buf),
1828                                      buff_off, len, DMA_TO_DEVICE);
1829        if (dma_mapping_error(device->dev, unmap->addr[0]))
1830                goto err_get_unmap;
1831
1832        unmap->to_cnt = 1;
1833
1834        txd = device->device_prep_dma_memcpy(chan, dest, unmap->addr[0], len,
1835                                             DMA_PREP_INTERRUPT);
1836        if (!txd)
1837                goto err_get_unmap;
1838
1839        txd->callback_result = ntb_tx_copy_callback;
1840        txd->callback_param = entry;
1841        dma_set_unmap(txd, unmap);
1842
1843        cookie = dmaengine_submit(txd);
1844        if (dma_submit_error(cookie))
1845                goto err_set_unmap;
1846
1847        dmaengine_unmap_put(unmap);
1848
1849        dma_async_issue_pending(chan);
1850
1851        return 0;
1852err_set_unmap:
1853        dmaengine_unmap_put(unmap);
1854err_get_unmap:
1855        dmaengine_unmap_put(unmap);
1856err:
1857        return -ENXIO;
1858}
1859
1860static void ntb_async_tx(struct ntb_transport_qp *qp,
1861                         struct ntb_queue_entry *entry)
1862{
1863        struct ntb_payload_header __iomem *hdr;
1864        struct dma_chan *chan = qp->tx_dma_chan;
1865        void __iomem *offset;
1866        int res;
1867
1868        entry->tx_index = qp->tx_index;
1869        offset = qp->tx_mw + qp->tx_max_frame * entry->tx_index;
1870        hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
1871        entry->tx_hdr = hdr;
1872
1873        iowrite32(entry->len, &hdr->len);
1874        iowrite32((u32)qp->tx_pkts, &hdr->ver);
1875
1876        if (!chan)
1877                goto err;
1878
1879        if (entry->len < copy_bytes)
1880                goto err;
1881
1882        res = ntb_async_tx_submit(qp, entry);
1883        if (res < 0)
1884                goto err;
1885
1886        if (!entry->retries)
1887                qp->tx_async++;
1888
1889        return;
1890
1891err:
1892        ntb_memcpy_tx(entry, offset);
1893        qp->tx_memcpy++;
1894}
1895
1896static int ntb_process_tx(struct ntb_transport_qp *qp,
1897                          struct ntb_queue_entry *entry)
1898{
1899        if (qp->tx_index == qp->remote_rx_info->entry) {
1900                qp->tx_ring_full++;
1901                return -EAGAIN;
1902        }
1903
1904        if (entry->len > qp->tx_max_frame - sizeof(struct ntb_payload_header)) {
1905                if (qp->tx_handler)
1906                        qp->tx_handler(qp, qp->cb_data, NULL, -EIO);
1907
1908                ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1909                             &qp->tx_free_q);
1910                return 0;
1911        }
1912
1913        ntb_async_tx(qp, entry);
1914
1915        qp->tx_index++;
1916        qp->tx_index %= qp->tx_max_entry;
1917
1918        qp->tx_pkts++;
1919
1920        return 0;
1921}
1922
1923static void ntb_send_link_down(struct ntb_transport_qp *qp)
1924{
1925        struct pci_dev *pdev = qp->ndev->pdev;
1926        struct ntb_queue_entry *entry;
1927        int i, rc;
1928
1929        if (!qp->link_is_up)
1930                return;
1931
1932        dev_info(&pdev->dev, "qp %d: Send Link Down\n", qp->qp_num);
1933
1934        for (i = 0; i < NTB_LINK_DOWN_TIMEOUT; i++) {
1935                entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1936                if (entry)
1937                        break;
1938                msleep(100);
1939        }
1940
1941        if (!entry)
1942                return;
1943
1944        entry->cb_data = NULL;
1945        entry->buf = NULL;
1946        entry->len = 0;
1947        entry->flags = LINK_DOWN_FLAG;
1948
1949        rc = ntb_process_tx(qp, entry);
1950        if (rc)
1951                dev_err(&pdev->dev, "ntb: QP%d unable to send linkdown msg\n",
1952                        qp->qp_num);
1953
1954        ntb_qp_link_down_reset(qp);
1955}
1956
1957static bool ntb_dma_filter_fn(struct dma_chan *chan, void *node)
1958{
1959        return dev_to_node(&chan->dev->device) == (int)(unsigned long)node;
1960}
1961
1962/**
1963 * ntb_transport_create_queue - Create a new NTB transport layer queue
1964 * @rx_handler: receive callback function
1965 * @tx_handler: transmit callback function
1966 * @event_handler: event callback function
1967 *
1968 * Create a new NTB transport layer queue and provide the queue with a callback
1969 * routine for both transmit and receive.  The receive callback routine will be
1970 * used to pass up data when the transport has received it on the queue.   The
1971 * transmit callback routine will be called when the transport has completed the
1972 * transmission of the data on the queue and the data is ready to be freed.
1973 *
1974 * RETURNS: pointer to newly created ntb_queue, NULL on error.
1975 */
1976struct ntb_transport_qp *
1977ntb_transport_create_queue(void *data, struct device *client_dev,
1978                           const struct ntb_queue_handlers *handlers)
1979{
1980        struct ntb_dev *ndev;
1981        struct pci_dev *pdev;
1982        struct ntb_transport_ctx *nt;
1983        struct ntb_queue_entry *entry;
1984        struct ntb_transport_qp *qp;
1985        u64 qp_bit;
1986        unsigned int free_queue;
1987        dma_cap_mask_t dma_mask;
1988        int node;
1989        int i;
1990
1991        ndev = dev_ntb(client_dev->parent);
1992        pdev = ndev->pdev;
1993        nt = ndev->ctx;
1994
1995        node = dev_to_node(&ndev->dev);
1996
1997        free_queue = ffs(nt->qp_bitmap_free);
1998        if (!free_queue)
1999                goto err;
2000
2001        /* decrement free_queue to make it zero based */
2002        free_queue--;
2003
2004        qp = &nt->qp_vec[free_queue];
2005        qp_bit = BIT_ULL(qp->qp_num);
2006
2007        nt->qp_bitmap_free &= ~qp_bit;
2008
2009        qp->cb_data = data;
2010        qp->rx_handler = handlers->rx_handler;
2011        qp->tx_handler = handlers->tx_handler;
2012        qp->event_handler = handlers->event_handler;
2013
2014        dma_cap_zero(dma_mask);
2015        dma_cap_set(DMA_MEMCPY, dma_mask);
2016
2017        if (use_dma) {
2018                qp->tx_dma_chan =
2019                        dma_request_channel(dma_mask, ntb_dma_filter_fn,
2020                                            (void *)(unsigned long)node);
2021                if (!qp->tx_dma_chan)
2022                        dev_info(&pdev->dev, "Unable to allocate TX DMA channel\n");
2023
2024                qp->rx_dma_chan =
2025                        dma_request_channel(dma_mask, ntb_dma_filter_fn,
2026                                            (void *)(unsigned long)node);
2027                if (!qp->rx_dma_chan)
2028                        dev_info(&pdev->dev, "Unable to allocate RX DMA channel\n");
2029        } else {
2030                qp->tx_dma_chan = NULL;
2031                qp->rx_dma_chan = NULL;
2032        }
2033
2034        qp->tx_mw_dma_addr = 0;
2035        if (qp->tx_dma_chan) {
2036                qp->tx_mw_dma_addr =
2037                        dma_map_resource(qp->tx_dma_chan->device->dev,
2038                                         qp->tx_mw_phys, qp->tx_mw_size,
2039                                         DMA_FROM_DEVICE, 0);
2040                if (dma_mapping_error(qp->tx_dma_chan->device->dev,
2041                                      qp->tx_mw_dma_addr)) {
2042                        qp->tx_mw_dma_addr = 0;
2043                        goto err1;
2044                }
2045        }
2046
2047        dev_dbg(&pdev->dev, "Using %s memcpy for TX\n",
2048                qp->tx_dma_chan ? "DMA" : "CPU");
2049
2050        dev_dbg(&pdev->dev, "Using %s memcpy for RX\n",
2051                qp->rx_dma_chan ? "DMA" : "CPU");
2052
2053        for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
2054                entry = kzalloc_node(sizeof(*entry), GFP_KERNEL, node);
2055                if (!entry)
2056                        goto err1;
2057
2058                entry->qp = qp;
2059                ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry,
2060                             &qp->rx_free_q);
2061        }
2062        qp->rx_alloc_entry = NTB_QP_DEF_NUM_ENTRIES;
2063
2064        for (i = 0; i < qp->tx_max_entry; i++) {
2065                entry = kzalloc_node(sizeof(*entry), GFP_KERNEL, node);
2066                if (!entry)
2067                        goto err2;
2068
2069                entry->qp = qp;
2070                ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
2071                             &qp->tx_free_q);
2072        }
2073
2074        ntb_db_clear(qp->ndev, qp_bit);
2075        ntb_db_clear_mask(qp->ndev, qp_bit);
2076
2077        dev_info(&pdev->dev, "NTB Transport QP %d created\n", qp->qp_num);
2078
2079        return qp;
2080
2081err2:
2082        while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
2083                kfree(entry);
2084err1:
2085        qp->rx_alloc_entry = 0;
2086        while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
2087                kfree(entry);
2088        if (qp->tx_mw_dma_addr)
2089                dma_unmap_resource(qp->tx_dma_chan->device->dev,
2090                                   qp->tx_mw_dma_addr, qp->tx_mw_size,
2091                                   DMA_FROM_DEVICE, 0);
2092        if (qp->tx_dma_chan)
2093                dma_release_channel(qp->tx_dma_chan);
2094        if (qp->rx_dma_chan)
2095                dma_release_channel(qp->rx_dma_chan);
2096        nt->qp_bitmap_free |= qp_bit;
2097err:
2098        return NULL;
2099}
2100EXPORT_SYMBOL_GPL(ntb_transport_create_queue);
2101
2102/**
2103 * ntb_transport_free_queue - Frees NTB transport queue
2104 * @qp: NTB queue to be freed
2105 *
2106 * Frees NTB transport queue
2107 */
2108void ntb_transport_free_queue(struct ntb_transport_qp *qp)
2109{
2110        struct pci_dev *pdev;
2111        struct ntb_queue_entry *entry;
2112        u64 qp_bit;
2113
2114        if (!qp)
2115                return;
2116
2117        pdev = qp->ndev->pdev;
2118
2119        qp->active = false;
2120
2121        if (qp->tx_dma_chan) {
2122                struct dma_chan *chan = qp->tx_dma_chan;
2123                /* Putting the dma_chan to NULL will force any new traffic to be
2124                 * processed by the CPU instead of the DAM engine
2125                 */
2126                qp->tx_dma_chan = NULL;
2127
2128                /* Try to be nice and wait for any queued DMA engine
2129                 * transactions to process before smashing it with a rock
2130                 */
2131                dma_sync_wait(chan, qp->last_cookie);
2132                dmaengine_terminate_all(chan);
2133
2134                dma_unmap_resource(chan->device->dev,
2135                                   qp->tx_mw_dma_addr, qp->tx_mw_size,
2136                                   DMA_FROM_DEVICE, 0);
2137
2138                dma_release_channel(chan);
2139        }
2140
2141        if (qp->rx_dma_chan) {
2142                struct dma_chan *chan = qp->rx_dma_chan;
2143                /* Putting the dma_chan to NULL will force any new traffic to be
2144                 * processed by the CPU instead of the DAM engine
2145                 */
2146                qp->rx_dma_chan = NULL;
2147
2148                /* Try to be nice and wait for any queued DMA engine
2149                 * transactions to process before smashing it with a rock
2150                 */
2151                dma_sync_wait(chan, qp->last_cookie);
2152                dmaengine_terminate_all(chan);
2153                dma_release_channel(chan);
2154        }
2155
2156        qp_bit = BIT_ULL(qp->qp_num);
2157
2158        ntb_db_set_mask(qp->ndev, qp_bit);
2159        tasklet_kill(&qp->rxc_db_work);
2160
2161        cancel_delayed_work_sync(&qp->link_work);
2162
2163        qp->cb_data = NULL;
2164        qp->rx_handler = NULL;
2165        qp->tx_handler = NULL;
2166        qp->event_handler = NULL;
2167
2168        while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
2169                kfree(entry);
2170
2171        while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_pend_q))) {
2172                dev_warn(&pdev->dev, "Freeing item from non-empty rx_pend_q\n");
2173                kfree(entry);
2174        }
2175
2176        while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_post_q))) {
2177                dev_warn(&pdev->dev, "Freeing item from non-empty rx_post_q\n");
2178                kfree(entry);
2179        }
2180
2181        while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
2182                kfree(entry);
2183
2184        qp->transport->qp_bitmap_free |= qp_bit;
2185
2186        dev_info(&pdev->dev, "NTB Transport QP %d freed\n", qp->qp_num);
2187}
2188EXPORT_SYMBOL_GPL(ntb_transport_free_queue);
2189
2190/**
2191 * ntb_transport_rx_remove - Dequeues enqueued rx packet
2192 * @qp: NTB queue to be freed
2193 * @len: pointer to variable to write enqueued buffers length
2194 *
2195 * Dequeues unused buffers from receive queue.  Should only be used during
2196 * shutdown of qp.
2197 *
2198 * RETURNS: NULL error value on error, or void* for success.
2199 */
2200void *ntb_transport_rx_remove(struct ntb_transport_qp *qp, unsigned int *len)
2201{
2202        struct ntb_queue_entry *entry;
2203        void *buf;
2204
2205        if (!qp || qp->client_ready)
2206                return NULL;
2207
2208        entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_pend_q);
2209        if (!entry)
2210                return NULL;
2211
2212        buf = entry->cb_data;
2213        *len = entry->len;
2214
2215        ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_free_q);
2216
2217        return buf;
2218}
2219EXPORT_SYMBOL_GPL(ntb_transport_rx_remove);
2220
2221/**
2222 * ntb_transport_rx_enqueue - Enqueue a new NTB queue entry
2223 * @qp: NTB transport layer queue the entry is to be enqueued on
2224 * @cb: per buffer pointer for callback function to use
2225 * @data: pointer to data buffer that incoming packets will be copied into
2226 * @len: length of the data buffer
2227 *
2228 * Enqueue a new receive buffer onto the transport queue into which a NTB
2229 * payload can be received into.
2230 *
2231 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
2232 */
2233int ntb_transport_rx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
2234                             unsigned int len)
2235{
2236        struct ntb_queue_entry *entry;
2237
2238        if (!qp)
2239                return -EINVAL;
2240
2241        entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q);
2242        if (!entry)
2243                return -ENOMEM;
2244
2245        entry->cb_data = cb;
2246        entry->buf = data;
2247        entry->len = len;
2248        entry->flags = 0;
2249        entry->retries = 0;
2250        entry->errors = 0;
2251        entry->rx_index = 0;
2252
2253        ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_pend_q);
2254
2255        if (qp->active)
2256                tasklet_schedule(&qp->rxc_db_work);
2257
2258        return 0;
2259}
2260EXPORT_SYMBOL_GPL(ntb_transport_rx_enqueue);
2261
2262/**
2263 * ntb_transport_tx_enqueue - Enqueue a new NTB queue entry
2264 * @qp: NTB transport layer queue the entry is to be enqueued on
2265 * @cb: per buffer pointer for callback function to use
2266 * @data: pointer to data buffer that will be sent
2267 * @len: length of the data buffer
2268 *
2269 * Enqueue a new transmit buffer onto the transport queue from which a NTB
2270 * payload will be transmitted.  This assumes that a lock is being held to
2271 * serialize access to the qp.
2272 *
2273 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
2274 */
2275int ntb_transport_tx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
2276                             unsigned int len)
2277{
2278        struct ntb_queue_entry *entry;
2279        int rc;
2280
2281        if (!qp || !qp->link_is_up || !len)
2282                return -EINVAL;
2283
2284        entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
2285        if (!entry) {
2286                qp->tx_err_no_buf++;
2287                return -EBUSY;
2288        }
2289
2290        entry->cb_data = cb;
2291        entry->buf = data;
2292        entry->len = len;
2293        entry->flags = 0;
2294        entry->errors = 0;
2295        entry->retries = 0;
2296        entry->tx_index = 0;
2297
2298        rc = ntb_process_tx(qp, entry);
2299        if (rc)
2300                ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
2301                             &qp->tx_free_q);
2302
2303        return rc;
2304}
2305EXPORT_SYMBOL_GPL(ntb_transport_tx_enqueue);
2306
2307/**
2308 * ntb_transport_link_up - Notify NTB transport of client readiness to use queue
2309 * @qp: NTB transport layer queue to be enabled
2310 *
2311 * Notify NTB transport layer of client readiness to use queue
2312 */
2313void ntb_transport_link_up(struct ntb_transport_qp *qp)
2314{
2315        if (!qp)
2316                return;
2317
2318        qp->client_ready = true;
2319
2320        if (qp->transport->link_is_up)
2321                schedule_delayed_work(&qp->link_work, 0);
2322}
2323EXPORT_SYMBOL_GPL(ntb_transport_link_up);
2324
2325/**
2326 * ntb_transport_link_down - Notify NTB transport to no longer enqueue data
2327 * @qp: NTB transport layer queue to be disabled
2328 *
2329 * Notify NTB transport layer of client's desire to no longer receive data on
2330 * transport queue specified.  It is the client's responsibility to ensure all
2331 * entries on queue are purged or otherwise handled appropriately.
2332 */
2333void ntb_transport_link_down(struct ntb_transport_qp *qp)
2334{
2335        int val;
2336
2337        if (!qp)
2338                return;
2339
2340        qp->client_ready = false;
2341
2342        val = ntb_spad_read(qp->ndev, QP_LINKS);
2343
2344        ntb_peer_spad_write(qp->ndev, PIDX, QP_LINKS, val & ~BIT(qp->qp_num));
2345
2346        if (qp->link_is_up)
2347                ntb_send_link_down(qp);
2348        else
2349                cancel_delayed_work_sync(&qp->link_work);
2350}
2351EXPORT_SYMBOL_GPL(ntb_transport_link_down);
2352
2353/**
2354 * ntb_transport_link_query - Query transport link state
2355 * @qp: NTB transport layer queue to be queried
2356 *
2357 * Query connectivity to the remote system of the NTB transport queue
2358 *
2359 * RETURNS: true for link up or false for link down
2360 */
2361bool ntb_transport_link_query(struct ntb_transport_qp *qp)
2362{
2363        if (!qp)
2364                return false;
2365
2366        return qp->link_is_up;
2367}
2368EXPORT_SYMBOL_GPL(ntb_transport_link_query);
2369
2370/**
2371 * ntb_transport_qp_num - Query the qp number
2372 * @qp: NTB transport layer queue to be queried
2373 *
2374 * Query qp number of the NTB transport queue
2375 *
2376 * RETURNS: a zero based number specifying the qp number
2377 */
2378unsigned char ntb_transport_qp_num(struct ntb_transport_qp *qp)
2379{
2380        if (!qp)
2381                return 0;
2382
2383        return qp->qp_num;
2384}
2385EXPORT_SYMBOL_GPL(ntb_transport_qp_num);
2386
2387/**
2388 * ntb_transport_max_size - Query the max payload size of a qp
2389 * @qp: NTB transport layer queue to be queried
2390 *
2391 * Query the maximum payload size permissible on the given qp
2392 *
2393 * RETURNS: the max payload size of a qp
2394 */
2395unsigned int ntb_transport_max_size(struct ntb_transport_qp *qp)
2396{
2397        unsigned int max_size;
2398        unsigned int copy_align;
2399        struct dma_chan *rx_chan, *tx_chan;
2400
2401        if (!qp)
2402                return 0;
2403
2404        rx_chan = qp->rx_dma_chan;
2405        tx_chan = qp->tx_dma_chan;
2406
2407        copy_align = max(rx_chan ? rx_chan->device->copy_align : 0,
2408                         tx_chan ? tx_chan->device->copy_align : 0);
2409
2410        /* If DMA engine usage is possible, try to find the max size for that */
2411        max_size = qp->tx_max_frame - sizeof(struct ntb_payload_header);
2412        max_size = round_down(max_size, 1 << copy_align);
2413
2414        return max_size;
2415}
2416EXPORT_SYMBOL_GPL(ntb_transport_max_size);
2417
2418unsigned int ntb_transport_tx_free_entry(struct ntb_transport_qp *qp)
2419{
2420        unsigned int head = qp->tx_index;
2421        unsigned int tail = qp->remote_rx_info->entry;
2422
2423        return tail > head ? tail - head : qp->tx_max_entry + tail - head;
2424}
2425EXPORT_SYMBOL_GPL(ntb_transport_tx_free_entry);
2426
2427static void ntb_transport_doorbell_callback(void *data, int vector)
2428{
2429        struct ntb_transport_ctx *nt = data;
2430        struct ntb_transport_qp *qp;
2431        u64 db_bits;
2432        unsigned int qp_num;
2433
2434        if (ntb_db_read(nt->ndev) & nt->msi_db_mask) {
2435                ntb_transport_msi_peer_desc_changed(nt);
2436                ntb_db_clear(nt->ndev, nt->msi_db_mask);
2437        }
2438
2439        db_bits = (nt->qp_bitmap & ~nt->qp_bitmap_free &
2440                   ntb_db_vector_mask(nt->ndev, vector));
2441
2442        while (db_bits) {
2443                qp_num = __ffs(db_bits);
2444                qp = &nt->qp_vec[qp_num];
2445
2446                if (qp->active)
2447                        tasklet_schedule(&qp->rxc_db_work);
2448
2449                db_bits &= ~BIT_ULL(qp_num);
2450        }
2451}
2452
2453static const struct ntb_ctx_ops ntb_transport_ops = {
2454        .link_event = ntb_transport_event_callback,
2455        .db_event = ntb_transport_doorbell_callback,
2456};
2457
2458static struct ntb_client ntb_transport_client = {
2459        .ops = {
2460                .probe = ntb_transport_probe,
2461                .remove = ntb_transport_free,
2462        },
2463};
2464
2465static int __init ntb_transport_init(void)
2466{
2467        int rc;
2468
2469        pr_info("%s, version %s\n", NTB_TRANSPORT_DESC, NTB_TRANSPORT_VER);
2470
2471        if (debugfs_initialized())
2472                nt_debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
2473
2474        rc = bus_register(&ntb_transport_bus);
2475        if (rc)
2476                goto err_bus;
2477
2478        rc = ntb_register_client(&ntb_transport_client);
2479        if (rc)
2480                goto err_client;
2481
2482        return 0;
2483
2484err_client:
2485        bus_unregister(&ntb_transport_bus);
2486err_bus:
2487        debugfs_remove_recursive(nt_debugfs_dir);
2488        return rc;
2489}
2490module_init(ntb_transport_init);
2491
2492static void __exit ntb_transport_exit(void)
2493{
2494        ntb_unregister_client(&ntb_transport_client);
2495        bus_unregister(&ntb_transport_bus);
2496        debugfs_remove_recursive(nt_debugfs_dir);
2497}
2498module_exit(ntb_transport_exit);
2499