drivers/ntb/ntb_transport.c

   1 /*
   2  * This file is provided under a dual BSD/GPLv2 license.  When using or
   3  *   redistributing this file, you may do so under either license.
   4  *
   5  *   GPL LICENSE SUMMARY
   6  *
   7  *   Copyright(c) 2012 Intel Corporation. All rights reserved.
   8  *   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
  71 MODULE_DESCRIPTION(NTB_TRANSPORT_DESC);
  72 MODULE_VERSION(NTB_TRANSPORT_VER);
  73 MODULE_LICENSE("Dual BSD/GPL");
  74 MODULE_AUTHOR("Intel Corporation");
  75
  76 static unsigned long max_mw_size;
  77 module_param(max_mw_size, ulong, 0644);
  78 MODULE_PARM_DESC(max_mw_size, "Limit size of large memory windows");
  79
  80 static unsigned int transport_mtu = 0x10000;
  81 module_param(transport_mtu, uint, 0644);
  82 MODULE_PARM_DESC(transport_mtu, "Maximum size of NTB transport packets");
  83
  84 static unsigned char max_num_clients;
  85 module_param(max_num_clients, byte, 0644);
  86 MODULE_PARM_DESC(max_num_clients, "Maximum number of NTB transport clients");
  87
  88 static unsigned int copy_bytes = 1024;
  89 module_param(copy_bytes, uint, 0644);
  90 MODULE_PARM_DESC(copy_bytes, "Threshold under which NTB will use the CPU to copy instead of DMA");
  91
  92 static bool use_dma;
  93 module_param(use_dma, bool, 0644);
  94 MODULE_PARM_DESC(use_dma, "Use DMA engine to perform large data copy");
  95
  96 static struct dentry *nt_debugfs_dir;
  97
  98 /* Only two-ports NTB devices are supported */
  99 #define PIDX            NTB_DEF_PEER_IDX
 100
 101 struct ntb_queue_entry {
 102         /* ntb_queue list reference */
 103         struct list_head entry;
 104         /* pointers to data to be transferred */
 105         void *cb_data;
 106         void *buf;
 107         unsigned int len;
 108         unsigned int flags;
 109         int retries;
 110         int errors;
 111         unsigned int tx_index;
 112         unsigned int rx_index;
 113
 114         struct ntb_transport_qp *qp;
 115         union {
 116                 struct ntb_payload_header __iomem *tx_hdr;
 117                 struct ntb_payload_header *rx_hdr;
 118         };
 119 };
 120
 121 struct ntb_rx_info {
 122         unsigned int entry;
 123 };
 124
 125 struct ntb_transport_qp {
 126         struct ntb_transport_ctx *transport;
 127         struct ntb_dev *ndev;
 128         void *cb_data;
 129         struct dma_chan *tx_dma_chan;
 130         struct dma_chan *rx_dma_chan;
 131
 132         bool client_ready;
 133         bool link_is_up;
 134         bool active;
 135
 136         u8 qp_num;      /* Only 64 QP's are allowed.  0-63 */
 137         u64 qp_bit;
 138
 139         struct ntb_rx_info __iomem *rx_info;
 140         struct ntb_rx_info *remote_rx_info;
 141
 142         void (*tx_handler)(struct ntb_transport_qp *qp, void *qp_data,
 143                            void *data, int len);
 144         struct list_head tx_free_q;
 145         spinlock_t ntb_tx_free_q_lock;
 146         void __iomem *tx_mw;
 147         dma_addr_t tx_mw_phys;
 148         unsigned int tx_index;
 149         unsigned int tx_max_entry;
 150         unsigned int tx_max_frame;
 151
 152         void (*rx_handler)(struct ntb_transport_qp *qp, void *qp_data,
 153                            void *data, int len);
 154         struct list_head rx_post_q;
 155         struct list_head rx_pend_q;
 156         struct list_head rx_free_q;
 157         /* ntb_rx_q_lock: synchronize access to rx_XXXX_q */
 158         spinlock_t ntb_rx_q_lock;
 159         void *rx_buff;
 160         unsigned int rx_index;
 161         unsigned int rx_max_entry;
 162         unsigned int rx_max_frame;
 163         unsigned int rx_alloc_entry;
 164         dma_cookie_t last_cookie;
 165         struct tasklet_struct rxc_db_work;
 166
 167         void (*event_handler)(void *data, int status);
 168         struct delayed_work link_work;
 169         struct work_struct link_cleanup;
 170
 171         struct dentry *debugfs_dir;
 172         struct dentry *debugfs_stats;
 173
 174         /* Stats */
 175         u64 rx_bytes;
 176         u64 rx_pkts;
 177         u64 rx_ring_empty;
 178         u64 rx_err_no_buf;
 179         u64 rx_err_oflow;
 180         u64 rx_err_ver;
 181         u64 rx_memcpy;
 182         u64 rx_async;
 183         u64 tx_bytes;
 184         u64 tx_pkts;
 185         u64 tx_ring_full;
 186         u64 tx_err_no_buf;
 187         u64 tx_memcpy;
 188         u64 tx_async;
 189 };
 190
 191 struct ntb_transport_mw {
 192         phys_addr_t phys_addr;
 193         resource_size_t phys_size;
 194         void __iomem *vbase;
 195         size_t xlat_size;
 196         size_t buff_size;
 197         size_t alloc_size;
 198         void *alloc_addr;
 199         void *virt_addr;
 200         dma_addr_t dma_addr;
 201 };
 202
 203 struct ntb_transport_client_dev {
 204         struct list_head entry;
 205         struct ntb_transport_ctx *nt;
 206         struct device dev;
 207 };
 208
 209 struct ntb_transport_ctx {
 210         struct list_head entry;
 211         struct list_head client_devs;
 212
 213         struct ntb_dev *ndev;
 214
 215         struct ntb_transport_mw *mw_vec;
 216         struct ntb_transport_qp *qp_vec;
 217         unsigned int mw_count;
 218         unsigned int qp_count;
 219         u64 qp_bitmap;
 220         u64 qp_bitmap_free;
 221
 222         bool link_is_up;
 223         struct delayed_work link_work;
 224         struct work_struct link_cleanup;
 225
 226         struct dentry *debugfs_node_dir;
 227 };
 228
 229 enum {
 230         DESC_DONE_FLAG = BIT(0),
 231         LINK_DOWN_FLAG = BIT(1),
 232 };
 233
 234 struct ntb_payload_header {
 235         unsigned int ver;
 236         unsigned int len;
 237         unsigned int flags;
 238 };
 239
 240 enum {
 241         VERSION = 0,
 242         QP_LINKS,
 243         NUM_QPS,
 244         NUM_MWS,
 245         MW0_SZ_HIGH,
 246         MW0_SZ_LOW,
 247 };
 248
 249 #define dev_client_dev(__dev) \
 250         container_of((__dev), struct ntb_transport_client_dev, dev)
 251
 252 #define drv_client(__drv) \
 253         container_of((__drv), struct ntb_transport_client, driver)
 254
 255 #define QP_TO_MW(nt, qp)        ((qp) % nt->mw_count)
 256 #define NTB_QP_DEF_NUM_ENTRIES  100
 257 #define NTB_LINK_DOWN_TIMEOUT   10
 258
 259 static void ntb_transport_rxc_db(unsigned long data);
 260 static const struct ntb_ctx_ops ntb_transport_ops;
 261 static struct ntb_client ntb_transport_client;
 262 static int ntb_async_tx_submit(struct ntb_transport_qp *qp,
 263                                struct ntb_queue_entry *entry);
 264 static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset);
 265 static int ntb_async_rx_submit(struct ntb_queue_entry *entry, void *offset);
 266 static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void *offset);
 267
 268
 269 static int ntb_transport_bus_match(struct device *dev,
 270                                    struct device_driver *drv)
 271 {
 272         return !strncmp(dev_name(dev), drv->name, strlen(drv->name));
 273 }
 274
 275 static int ntb_transport_bus_probe(struct device *dev)
 276 {
 277         const struct ntb_transport_client *client;
 278         int rc = -EINVAL;
 279
 280         get_device(dev);
 281
 282         client = drv_client(dev->driver);
 283         rc = client->probe(dev);
 284         if (rc)
 285                 put_device(dev);
 286
 287         return rc;
 288 }
 289
 290 static int ntb_transport_bus_remove(struct device *dev)
 291 {
 292         const struct ntb_transport_client *client;
 293
 294         client = drv_client(dev->driver);
 295         client->remove(dev);
 296
 297         put_device(dev);
 298
 299         return 0;
 300 }
 301
 302 static struct bus_type ntb_transport_bus = {
 303         .name = "ntb_transport",
 304         .match = ntb_transport_bus_match,
 305         .probe = ntb_transport_bus_probe,
 306         .remove = ntb_transport_bus_remove,
 307 };
 308
 309 static LIST_HEAD(ntb_transport_list);
 310
 311 static int ntb_bus_init(struct ntb_transport_ctx *nt)
 312 {
 313         list_add_tail(&nt->entry, &ntb_transport_list);
 314         return 0;
 315 }
 316
 317 static void ntb_bus_remove(struct ntb_transport_ctx *nt)
 318 {
 319         struct ntb_transport_client_dev *client_dev, *cd;
 320
 321         list_for_each_entry_safe(client_dev, cd, &nt->client_devs, entry) {
 322                 dev_err(client_dev->dev.parent, "%s still attached to bus, removing\n",
 323                         dev_name(&client_dev->dev));
 324                 list_del(&client_dev->entry);
 325                 device_unregister(&client_dev->dev);
 326         }
 327
 328         list_del(&nt->entry);
 329 }
 330
 331 static void ntb_transport_client_release(struct device *dev)
 332 {
 333         struct ntb_transport_client_dev *client_dev;
 334
 335         client_dev = dev_client_dev(dev);
 336         kfree(client_dev);
 337 }
 338
 339 /**
 340  * ntb_transport_unregister_client_dev - Unregister NTB client device
 341  * @device_name: Name of NTB client device
 342  *
 343  * Unregister an NTB client device with the NTB transport layer
 344  */
 345 void ntb_transport_unregister_client_dev(char *device_name)
 346 {
 347         struct ntb_transport_client_dev *client, *cd;
 348         struct ntb_transport_ctx *nt;
 349
 350         list_for_each_entry(nt, &ntb_transport_list, entry)
 351                 list_for_each_entry_safe(client, cd, &nt->client_devs, entry)
 352                         if (!strncmp(dev_name(&client->dev), device_name,
 353                                      strlen(device_name))) {
 354                                 list_del(&client->entry);
 355                                 device_unregister(&client->dev);
 356                         }
 357 }
 358 EXPORT_SYMBOL_GPL(ntb_transport_unregister_client_dev);
 359
 360 /**
 361  * ntb_transport_register_client_dev - Register NTB client device
 362  * @device_name: Name of NTB client device
 363  *
 364  * Register an NTB client device with the NTB transport layer
 365  */
 366 int ntb_transport_register_client_dev(char *device_name)
 367 {
 368         struct ntb_transport_client_dev *client_dev;
 369         struct ntb_transport_ctx *nt;
 370         int node;
 371         int rc, i = 0;
 372
 373         if (list_empty(&ntb_transport_list))
 374                 return -ENODEV;
 375
 376         list_for_each_entry(nt, &ntb_transport_list, entry) {
 377                 struct device *dev;
 378
 379                 node = dev_to_node(&nt->ndev->dev);
 380
 381                 client_dev = kzalloc_node(sizeof(*client_dev),
 382                                           GFP_KERNEL, node);
 383                 if (!client_dev) {
 384                         rc = -ENOMEM;
 385                         goto err;
 386                 }
 387
 388                 dev = &client_dev->dev;
 389
 390                 /* setup and register client devices */
 391                 dev_set_name(dev, "%s%d", device_name, i);
 392                 dev->bus = &ntb_transport_bus;
 393                 dev->release = ntb_transport_client_release;
 394                 dev->parent = &nt->ndev->dev;
 395
 396                 rc = device_register(dev);
 397                 if (rc) {
 398                         kfree(client_dev);
 399                         goto err;
 400                 }
 401
 402                 list_add_tail(&client_dev->entry, &nt->client_devs);
 403                 i++;
 404         }
 405
 406         return 0;
 407
 408 err:
 409         ntb_transport_unregister_client_dev(device_name);
 410
 411         return rc;
 412 }
 413 EXPORT_SYMBOL_GPL(ntb_transport_register_client_dev);
 414
 415 /**
 416  * ntb_transport_register_client - Register NTB client driver
 417  * @drv: NTB client driver to be registered
 418  *
 419  * Register an NTB client driver with the NTB transport layer
 420  *
 421  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 422  */
 423 int ntb_transport_register_client(struct ntb_transport_client *drv)
 424 {
 425         drv->driver.bus = &ntb_transport_bus;
 426
 427         if (list_empty(&ntb_transport_list))
 428                 return -ENODEV;
 429
 430         return driver_register(&drv->driver);
 431 }
 432 EXPORT_SYMBOL_GPL(ntb_transport_register_client);
 433
 434 /**
 435  * ntb_transport_unregister_client - Unregister NTB client driver
 436  * @drv: NTB client driver to be unregistered
 437  *
 438  * Unregister an NTB client driver with the NTB transport layer
 439  *
 440  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 441  */
 442 void ntb_transport_unregister_client(struct ntb_transport_client *drv)
 443 {
 444         driver_unregister(&drv->driver);
 445 }
 446 EXPORT_SYMBOL_GPL(ntb_transport_unregister_client);
 447
 448 static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count,
 449                             loff_t *offp)
 450 {
 451         struct ntb_transport_qp *qp;
 452         char *buf;
 453         ssize_t ret, out_offset, out_count;
 454
 455         qp = filp->private_data;
 456
 457         if (!qp || !qp->link_is_up)
 458                 return 0;
 459
 460         out_count = 1000;
 461
 462         buf = kmalloc(out_count, GFP_KERNEL);
 463         if (!buf)
 464                 return -ENOMEM;
 465
 466         out_offset = 0;
 467         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 468                                "\nNTB QP stats:\n\n");
 469         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 470                                "rx_bytes - \t%llu\n", qp->rx_bytes);
 471         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 472                                "rx_pkts - \t%llu\n", qp->rx_pkts);
 473         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 474                                "rx_memcpy - \t%llu\n", qp->rx_memcpy);
 475         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 476                                "rx_async - \t%llu\n", qp->rx_async);
 477         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 478                                "rx_ring_empty - %llu\n", qp->rx_ring_empty);
 479         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 480                                "rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
 481         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 482                                "rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
 483         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 484                                "rx_err_ver - \t%llu\n", qp->rx_err_ver);
 485         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 486                                "rx_buff - \t0x%p\n", qp->rx_buff);
 487         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 488                                "rx_index - \t%u\n", qp->rx_index);
 489         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 490                                "rx_max_entry - \t%u\n", qp->rx_max_entry);
 491         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 492                                "rx_alloc_entry - \t%u\n\n", qp->rx_alloc_entry);
 493
 494         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 495                                "tx_bytes - \t%llu\n", qp->tx_bytes);
 496         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 497                                "tx_pkts - \t%llu\n", qp->tx_pkts);
 498         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 499                                "tx_memcpy - \t%llu\n", qp->tx_memcpy);
 500         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 501                                "tx_async - \t%llu\n", qp->tx_async);
 502         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 503                                "tx_ring_full - \t%llu\n", qp->tx_ring_full);
 504         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 505                                "tx_err_no_buf - %llu\n", qp->tx_err_no_buf);
 506         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 507                                "tx_mw - \t0x%p\n", qp->tx_mw);
 508         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 509                                "tx_index (H) - \t%u\n", qp->tx_index);
 510         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 511                                "RRI (T) - \t%u\n",
 512                                qp->remote_rx_info->entry);
 513         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 514                                "tx_max_entry - \t%u\n", qp->tx_max_entry);
 515         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 516                                "free tx - \t%u\n",
 517                                ntb_transport_tx_free_entry(qp));
 518
 519         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 520                                "\n");
 521         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 522                                "Using TX DMA - \t%s\n",
 523                                qp->tx_dma_chan ? "Yes" : "No");
 524         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 525                                "Using RX DMA - \t%s\n",
 526                                qp->rx_dma_chan ? "Yes" : "No");
 527         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 528                                "QP Link - \t%s\n",
 529                                qp->link_is_up ? "Up" : "Down");
 530         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 531                                "\n");
 532
 533         if (out_offset > out_count)
 534                 out_offset = out_count;
 535
 536         ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
 537         kfree(buf);
 538         return ret;
 539 }
 540
 541 static const struct file_operations ntb_qp_debugfs_stats = {
 542         .owner = THIS_MODULE,
 543         .open = simple_open,
 544         .read = debugfs_read,
 545 };
 546
 547 static void ntb_list_add(spinlock_t *lock, struct list_head *entry,
 548                          struct list_head *list)
 549 {
 550         unsigned long flags;
 551
 552         spin_lock_irqsave(lock, flags);
 553         list_add_tail(entry, list);
 554         spin_unlock_irqrestore(lock, flags);
 555 }
 556
 557 static struct ntb_queue_entry *ntb_list_rm(spinlock_t *lock,
 558                                            struct list_head *list)
 559 {
 560         struct ntb_queue_entry *entry;
 561         unsigned long flags;
 562
 563         spin_lock_irqsave(lock, flags);
 564         if (list_empty(list)) {
 565                 entry = NULL;
 566                 goto out;
 567         }
 568         entry = list_first_entry(list, struct ntb_queue_entry, entry);
 569         list_del(&entry->entry);
 570
 571 out:
 572         spin_unlock_irqrestore(lock, flags);
 573
 574         return entry;
 575 }
 576
 577 static struct ntb_queue_entry *ntb_list_mv(spinlock_t *lock,
 578                                            struct list_head *list,
 579                                            struct list_head *to_list)
 580 {
 581         struct ntb_queue_entry *entry;
 582         unsigned long flags;
 583
 584         spin_lock_irqsave(lock, flags);
 585
 586         if (list_empty(list)) {
 587                 entry = NULL;
 588         } else {
 589                 entry = list_first_entry(list, struct ntb_queue_entry, entry);
 590                 list_move_tail(&entry->entry, to_list);
 591         }
 592
 593         spin_unlock_irqrestore(lock, flags);
 594
 595         return entry;
 596 }
 597
 598 static int ntb_transport_setup_qp_mw(struct ntb_transport_ctx *nt,
 599                                      unsigned int qp_num)
 600 {
 601         struct ntb_transport_qp *qp = &nt->qp_vec[qp_num];
 602         struct ntb_transport_mw *mw;
 603         struct ntb_dev *ndev = nt->ndev;
 604         struct ntb_queue_entry *entry;
 605         unsigned int rx_size, num_qps_mw;
 606         unsigned int mw_num, mw_count, qp_count;
 607         unsigned int i;
 608         int node;
 609
 610         mw_count = nt->mw_count;
 611         qp_count = nt->qp_count;
 612
 613         mw_num = QP_TO_MW(nt, qp_num);
 614         mw = &nt->mw_vec[mw_num];
 615
 616         if (!mw->virt_addr)
 617                 return -ENOMEM;
 618
 619         if (mw_num < qp_count % mw_count)
 620                 num_qps_mw = qp_count / mw_count + 1;
 621         else
 622                 num_qps_mw = qp_count / mw_count;
 623
 624         rx_size = (unsigned int)mw->xlat_size / num_qps_mw;
 625         qp->rx_buff = mw->virt_addr + rx_size * (qp_num / mw_count);
 626         rx_size -= sizeof(struct ntb_rx_info);
 627
 628         qp->remote_rx_info = qp->rx_buff + rx_size;
 629
 630         /* Due to housekeeping, there must be atleast 2 buffs */
 631         qp->rx_max_frame = min(transport_mtu, rx_size / 2);
 632         qp->rx_max_entry = rx_size / qp->rx_max_frame;
 633         qp->rx_index = 0;
 634
 635         /*
 636          * Checking to see if we have more entries than the default.
 637          * We should add additional entries if that is the case so we
 638          * can be in sync with the transport frames.
 639          */
 640         node = dev_to_node(&ndev->dev);
 641         for (i = qp->rx_alloc_entry; i < qp->rx_max_entry; i++) {
 642                 entry = kzalloc_node(sizeof(*entry), GFP_KERNEL, node);
 643                 if (!entry)
 644                         return -ENOMEM;
 645
 646                 entry->qp = qp;
 647                 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry,
 648                              &qp->rx_free_q);
 649                 qp->rx_alloc_entry++;
 650         }
 651
 652         qp->remote_rx_info->entry = qp->rx_max_entry - 1;
 653
 654         /* setup the hdr offsets with 0's */
 655         for (i = 0; i < qp->rx_max_entry; i++) {
 656                 void *offset = (qp->rx_buff + qp->rx_max_frame * (i + 1) -
 657                                 sizeof(struct ntb_payload_header));
 658                 memset(offset, 0, sizeof(struct ntb_payload_header));
 659         }
 660
 661         qp->rx_pkts = 0;
 662         qp->tx_pkts = 0;
 663         qp->tx_index = 0;
 664
 665         return 0;
 666 }
 667
 668 static void ntb_free_mw(struct ntb_transport_ctx *nt, int num_mw)
 669 {
 670         struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
 671         struct pci_dev *pdev = nt->ndev->pdev;
 672
 673         if (!mw->virt_addr)
 674                 return;
 675
 676         ntb_mw_clear_trans(nt->ndev, PIDX, num_mw);
 677         dma_free_coherent(&pdev->dev, mw->alloc_size,
 678                           mw->alloc_addr, mw->dma_addr);
 679         mw->xlat_size = 0;
 680         mw->buff_size = 0;
 681         mw->alloc_size = 0;
 682         mw->alloc_addr = NULL;
 683         mw->virt_addr = NULL;
 684 }
 685
 686 static int ntb_alloc_mw_buffer(struct ntb_transport_mw *mw,
 687                                struct device *dma_dev, size_t align)
 688 {
 689         dma_addr_t dma_addr;
 690         void *alloc_addr, *virt_addr;
 691         int rc;
 692
 693         alloc_addr = dma_alloc_coherent(dma_dev, mw->alloc_size,
 694                                         &dma_addr, GFP_KERNEL);
 695         if (!alloc_addr) {
 696                 dev_err(dma_dev, "Unable to alloc MW buff of size %zu\n",
 697                         mw->alloc_size);
 698                 return -ENOMEM;
 699         }
 700         virt_addr = alloc_addr;
 701
 702         /*
 703          * we must ensure that the memory address allocated is BAR size
 704          * aligned in order for the XLAT register to take the value. This
 705          * is a requirement of the hardware. It is recommended to setup CMA
 706          * for BAR sizes equal or greater than 4MB.
 707          */
 708         if (!IS_ALIGNED(dma_addr, align)) {
 709                 if (mw->alloc_size > mw->buff_size) {
 710                         virt_addr = PTR_ALIGN(alloc_addr, align);
 711                         dma_addr = ALIGN(dma_addr, align);
 712                 } else {
 713                         rc = -ENOMEM;
 714                         goto err;
 715                 }
 716         }
 717
 718         mw->alloc_addr = alloc_addr;
 719         mw->virt_addr = virt_addr;
 720         mw->dma_addr = dma_addr;
 721
 722         return 0;
 723
 724 err:
 725         dma_free_coherent(dma_dev, mw->alloc_size, alloc_addr, dma_addr);
 726
 727         return rc;
 728 }
 729
 730 static int ntb_set_mw(struct ntb_transport_ctx *nt, int num_mw,
 731                       resource_size_t size)
 732 {
 733         struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
 734         struct pci_dev *pdev = nt->ndev->pdev;
 735         size_t xlat_size, buff_size;
 736         resource_size_t xlat_align;
 737         resource_size_t xlat_align_size;
 738         int rc;
 739
 740         if (!size)
 741                 return -EINVAL;
 742
 743         rc = ntb_mw_get_align(nt->ndev, PIDX, num_mw, &xlat_align,
 744                               &xlat_align_size, NULL);
 745         if (rc)
 746                 return rc;
 747
 748         xlat_size = round_up(size, xlat_align_size);
 749         buff_size = round_up(size, xlat_align);
 750
 751         /* No need to re-setup */
 752         if (mw->xlat_size == xlat_size)
 753                 return 0;
 754
 755         if (mw->buff_size)
 756                 ntb_free_mw(nt, num_mw);
 757
 758         /* Alloc memory for receiving data.  Must be aligned */
 759         mw->xlat_size = xlat_size;
 760         mw->buff_size = buff_size;
 761         mw->alloc_size = buff_size;
 762
 763         rc = ntb_alloc_mw_buffer(mw, &pdev->dev, xlat_align);
 764         if (rc) {
 765                 mw->alloc_size *= 2;
 766                 rc = ntb_alloc_mw_buffer(mw, &pdev->dev, xlat_align);
 767                 if (rc) {
 768                         dev_err(&pdev->dev,
 769                                 "Unable to alloc aligned MW buff\n");
 770                         mw->xlat_size = 0;
 771                         mw->buff_size = 0;
 772                         mw->alloc_size = 0;
 773                         return rc;
 774                 }
 775         }
 776
 777         /* Notify HW the memory location of the receive buffer */
 778         rc = ntb_mw_set_trans(nt->ndev, PIDX, num_mw, mw->dma_addr,
 779                               mw->xlat_size);
 780         if (rc) {
 781                 dev_err(&pdev->dev, "Unable to set mw%d translation", num_mw);
 782                 ntb_free_mw(nt, num_mw);
 783                 return -EIO;
 784         }
 785
 786         return 0;
 787 }
 788
 789 static void ntb_qp_link_down_reset(struct ntb_transport_qp *qp)
 790 {
 791         qp->link_is_up = false;
 792         qp->active = false;
 793
 794         qp->tx_index = 0;
 795         qp->rx_index = 0;
 796         qp->rx_bytes = 0;
 797         qp->rx_pkts = 0;
 798         qp->rx_ring_empty = 0;
 799         qp->rx_err_no_buf = 0;
 800         qp->rx_err_oflow = 0;
 801         qp->rx_err_ver = 0;
 802         qp->rx_memcpy = 0;
 803         qp->rx_async = 0;
 804         qp->tx_bytes = 0;
 805         qp->tx_pkts = 0;
 806         qp->tx_ring_full = 0;
 807         qp->tx_err_no_buf = 0;
 808         qp->tx_memcpy = 0;
 809         qp->tx_async = 0;
 810 }
 811
 812 static void ntb_qp_link_cleanup(struct ntb_transport_qp *qp)
 813 {
 814         struct ntb_transport_ctx *nt = qp->transport;
 815         struct pci_dev *pdev = nt->ndev->pdev;
 816
 817         dev_info(&pdev->dev, "qp %d: Link Cleanup\n", qp->qp_num);
 818
 819         cancel_delayed_work_sync(&qp->link_work);
 820         ntb_qp_link_down_reset(qp);
 821
 822         if (qp->event_handler)
 823                 qp->event_handler(qp->cb_data, qp->link_is_up);
 824 }
 825
 826 static void ntb_qp_link_cleanup_work(struct work_struct *work)
 827 {
 828         struct ntb_transport_qp *qp = container_of(work,
 829                                                    struct ntb_transport_qp,
 830                                                    link_cleanup);
 831         struct ntb_transport_ctx *nt = qp->transport;
 832
 833         ntb_qp_link_cleanup(qp);
 834
 835         if (nt->link_is_up)
 836                 schedule_delayed_work(&qp->link_work,
 837                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 838 }
 839
 840 static void ntb_qp_link_down(struct ntb_transport_qp *qp)
 841 {
 842         schedule_work(&qp->link_cleanup);
 843 }
 844
 845 static void ntb_transport_link_cleanup(struct ntb_transport_ctx *nt)
 846 {
 847         struct ntb_transport_qp *qp;
 848         u64 qp_bitmap_alloc;
 849         unsigned int i, count;
 850
 851         qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
 852
 853         /* Pass along the info to any clients */
 854         for (i = 0; i < nt->qp_count; i++)
 855                 if (qp_bitmap_alloc & BIT_ULL(i)) {
 856                         qp = &nt->qp_vec[i];
 857                         ntb_qp_link_cleanup(qp);
 858                         cancel_work_sync(&qp->link_cleanup);
 859                         cancel_delayed_work_sync(&qp->link_work);
 860                 }
 861
 862         if (!nt->link_is_up)
 863                 cancel_delayed_work_sync(&nt->link_work);
 864
 865         /* The scratchpad registers keep the values if the remote side
 866          * goes down, blast them now to give them a sane value the next
 867          * time they are accessed
 868          */
 869         count = ntb_spad_count(nt->ndev);
 870         for (i = 0; i < count; i++)
 871                 ntb_spad_write(nt->ndev, i, 0);
 872 }
 873
 874 static void ntb_transport_link_cleanup_work(struct work_struct *work)
 875 {
 876         struct ntb_transport_ctx *nt =
 877                 container_of(work, struct ntb_transport_ctx, link_cleanup);
 878
 879         ntb_transport_link_cleanup(nt);
 880 }
 881
 882 static void ntb_transport_event_callback(void *data)
 883 {
 884         struct ntb_transport_ctx *nt = data;
 885
 886         if (ntb_link_is_up(nt->ndev, NULL, NULL) == 1)
 887                 schedule_delayed_work(&nt->link_work, 0);
 888         else
 889                 schedule_work(&nt->link_cleanup);
 890 }
 891
 892 static void ntb_transport_link_work(struct work_struct *work)
 893 {
 894         struct ntb_transport_ctx *nt =
 895                 container_of(work, struct ntb_transport_ctx, link_work.work);
 896         struct ntb_dev *ndev = nt->ndev;
 897         struct pci_dev *pdev = ndev->pdev;
 898         resource_size_t size;
 899         u32 val;
 900         int rc = 0, i, spad;
 901
 902         /* send the local info, in the opposite order of the way we read it */
 903         for (i = 0; i < nt->mw_count; i++) {
 904                 size = nt->mw_vec[i].phys_size;
 905
 906                 if (max_mw_size && size > max_mw_size)
 907                         size = max_mw_size;
 908
 909                 spad = MW0_SZ_HIGH + (i * 2);
 910                 ntb_peer_spad_write(ndev, PIDX, spad, upper_32_bits(size));
 911
 912                 spad = MW0_SZ_LOW + (i * 2);
 913                 ntb_peer_spad_write(ndev, PIDX, spad, lower_32_bits(size));
 914         }
 915
 916         ntb_peer_spad_write(ndev, PIDX, NUM_MWS, nt->mw_count);
 917
 918         ntb_peer_spad_write(ndev, PIDX, NUM_QPS, nt->qp_count);
 919
 920         ntb_peer_spad_write(ndev, PIDX, VERSION, NTB_TRANSPORT_VERSION);
 921
 922         /* Query the remote side for its info */
 923         val = ntb_spad_read(ndev, VERSION);
 924         dev_dbg(&pdev->dev, "Remote version = %d\n", val);
 925         if (val != NTB_TRANSPORT_VERSION)
 926                 goto out;
 927
 928         val = ntb_spad_read(ndev, NUM_QPS);
 929         dev_dbg(&pdev->dev, "Remote max number of qps = %d\n", val);
 930         if (val != nt->qp_count)
 931                 goto out;
 932
 933         val = ntb_spad_read(ndev, NUM_MWS);
 934         dev_dbg(&pdev->dev, "Remote number of mws = %d\n", val);
 935         if (val != nt->mw_count)
 936                 goto out;
 937
 938         for (i = 0; i < nt->mw_count; i++) {
 939                 u64 val64;
 940
 941                 val = ntb_spad_read(ndev, MW0_SZ_HIGH + (i * 2));
 942                 val64 = (u64)val << 32;
 943
 944                 val = ntb_spad_read(ndev, MW0_SZ_LOW + (i * 2));
 945                 val64 |= val;
 946
 947                 dev_dbg(&pdev->dev, "Remote MW%d size = %#llx\n", i, val64);
 948
 949                 rc = ntb_set_mw(nt, i, val64);
 950                 if (rc)
 951                         goto out1;
 952         }
 953
 954         nt->link_is_up = true;
 955
 956         for (i = 0; i < nt->qp_count; i++) {
 957                 struct ntb_transport_qp *qp = &nt->qp_vec[i];
 958
 959                 ntb_transport_setup_qp_mw(nt, i);
 960
 961                 if (qp->client_ready)
 962                         schedule_delayed_work(&qp->link_work, 0);
 963         }
 964
 965         return;
 966
 967 out1:
 968         for (i = 0; i < nt->mw_count; i++)
 969                 ntb_free_mw(nt, i);
 970
 971         /* if there's an actual failure, we should just bail */
 972         if (rc < 0)
 973                 return;
 974
 975 out:
 976         if (ntb_link_is_up(ndev, NULL, NULL) == 1)
 977                 schedule_delayed_work(&nt->link_work,
 978                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 979 }
 980
 981 static void ntb_qp_link_work(struct work_struct *work)
 982 {
 983         struct ntb_transport_qp *qp = container_of(work,
 984                                                    struct ntb_transport_qp,
 985                                                    link_work.work);
 986         struct pci_dev *pdev = qp->ndev->pdev;
 987         struct ntb_transport_ctx *nt = qp->transport;
 988         int val;
 989
 990         WARN_ON(!nt->link_is_up);
 991
 992         val = ntb_spad_read(nt->ndev, QP_LINKS);
 993
 994         ntb_peer_spad_write(nt->ndev, PIDX, QP_LINKS, val | BIT(qp->qp_num));
 995
 996         /* query remote spad for qp ready bits */
 997         dev_dbg_ratelimited(&pdev->dev, "Remote QP link status = %x\n", val);
 998
 999         /* See if the remote side is up */
1000         if (val & BIT(qp->qp_num)) {
1001                 dev_info(&pdev->dev, "qp %d: Link Up\n", qp->qp_num);
1002                 qp->link_is_up = true;
1003                 qp->active = true;
1004
1005                 if (qp->event_handler)
1006                         qp->event_handler(qp->cb_data, qp->link_is_up);
1007
1008                 if (qp->active)
1009                         tasklet_schedule(&qp->rxc_db_work);
1010         } else if (nt->link_is_up)
1011                 schedule_delayed_work(&qp->link_work,
1012                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
1013 }
1014
1015 static int ntb_transport_init_queue(struct ntb_transport_ctx *nt,
1016                                     unsigned int qp_num)
1017 {
1018         struct ntb_transport_qp *qp;
1019         phys_addr_t mw_base;
1020         resource_size_t mw_size;
1021         unsigned int num_qps_mw, tx_size;
1022         unsigned int mw_num, mw_count, qp_count;
1023         u64 qp_offset;
1024
1025         mw_count = nt->mw_count;
1026         qp_count = nt->qp_count;
1027
1028         mw_num = QP_TO_MW(nt, qp_num);
1029
1030         qp = &nt->qp_vec[qp_num];
1031         qp->qp_num = qp_num;
1032         qp->transport = nt;
1033         qp->ndev = nt->ndev;
1034         qp->client_ready = false;
1035         qp->event_handler = NULL;
1036         ntb_qp_link_down_reset(qp);
1037
1038         if (mw_num < qp_count % mw_count)
1039                 num_qps_mw = qp_count / mw_count + 1;
1040         else
1041                 num_qps_mw = qp_count / mw_count;
1042
1043         mw_base = nt->mw_vec[mw_num].phys_addr;
1044         mw_size = nt->mw_vec[mw_num].phys_size;
1045
1046         if (max_mw_size && mw_size > max_mw_size)
1047                 mw_size = max_mw_size;
1048
1049         tx_size = (unsigned int)mw_size / num_qps_mw;
1050         qp_offset = tx_size * (qp_num / mw_count);
1051
1052         qp->tx_mw = nt->mw_vec[mw_num].vbase + qp_offset;
1053         if (!qp->tx_mw)
1054                 return -EINVAL;
1055
1056         qp->tx_mw_phys = mw_base + qp_offset;
1057         if (!qp->tx_mw_phys)
1058                 return -EINVAL;
1059
1060         tx_size -= sizeof(struct ntb_rx_info);
1061         qp->rx_info = qp->tx_mw + tx_size;
1062
1063         /* Due to housekeeping, there must be atleast 2 buffs */
1064         qp->tx_max_frame = min(transport_mtu, tx_size / 2);
1065         qp->tx_max_entry = tx_size / qp->tx_max_frame;
1066
1067         if (nt->debugfs_node_dir) {
1068                 char debugfs_name[4];
1069
1070                 snprintf(debugfs_name, 4, "qp%d", qp_num);
1071                 qp->debugfs_dir = debugfs_create_dir(debugfs_name,
1072                                                      nt->debugfs_node_dir);
1073
1074                 qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR,
1075                                                         qp->debugfs_dir, qp,
1076                                                         &ntb_qp_debugfs_stats);
1077         } else {
1078                 qp->debugfs_dir = NULL;
1079                 qp->debugfs_stats = NULL;
1080         }
1081
1082         INIT_DELAYED_WORK(&qp->link_work, ntb_qp_link_work);
1083         INIT_WORK(&qp->link_cleanup, ntb_qp_link_cleanup_work);
1084
1085         spin_lock_init(&qp->ntb_rx_q_lock);
1086         spin_lock_init(&qp->ntb_tx_free_q_lock);
1087
1088         INIT_LIST_HEAD(&qp->rx_post_q);
1089         INIT_LIST_HEAD(&qp->rx_pend_q);
1090         INIT_LIST_HEAD(&qp->rx_free_q);
1091         INIT_LIST_HEAD(&qp->tx_free_q);
1092
1093         tasklet_init(&qp->rxc_db_work, ntb_transport_rxc_db,
1094                      (unsigned long)qp);
1095
1096         return 0;
1097 }
1098
1099 static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev)
1100 {
1101         struct ntb_transport_ctx *nt;
1102         struct ntb_transport_mw *mw;
1103         unsigned int mw_count, qp_count, spad_count, max_mw_count_for_spads;
1104         u64 qp_bitmap;
1105         int node;
1106         int rc, i;
1107
1108         mw_count = ntb_peer_mw_count(ndev);
1109
1110         if (!ndev->ops->mw_set_trans) {
1111                 dev_err(&ndev->dev, "Inbound MW based NTB API is required\n");
1112                 return -EINVAL;
1113         }
1114
1115         if (ntb_db_is_unsafe(ndev))
1116                 dev_dbg(&ndev->dev,
1117                         "doorbell is unsafe, proceed anyway...\n");
1118         if (ntb_spad_is_unsafe(ndev))
1119                 dev_dbg(&ndev->dev,
1120                         "scratchpad is unsafe, proceed anyway...\n");
1121
1122         if (ntb_peer_port_count(ndev) != NTB_DEF_PEER_CNT)
1123                 dev_warn(&ndev->dev, "Multi-port NTB devices unsupported\n");
1124
1125         node = dev_to_node(&ndev->dev);
1126
1127         nt = kzalloc_node(sizeof(*nt), GFP_KERNEL, node);
1128         if (!nt)
1129                 return -ENOMEM;
1130
1131         nt->ndev = ndev;
1132         spad_count = ntb_spad_count(ndev);
1133
1134         /* Limit the MW's based on the availability of scratchpads */
1135
1136         if (spad_count < NTB_TRANSPORT_MIN_SPADS) {
1137                 nt->mw_count = 0;
1138                 rc = -EINVAL;
1139                 goto err;
1140         }
1141
1142         max_mw_count_for_spads = (spad_count - MW0_SZ_HIGH) / 2;
1143         nt->mw_count = min(mw_count, max_mw_count_for_spads);
1144
1145         nt->mw_vec = kcalloc_node(mw_count, sizeof(*nt->mw_vec),
1146                                   GFP_KERNEL, node);
1147         if (!nt->mw_vec) {
1148                 rc = -ENOMEM;
1149                 goto err;
1150         }
1151
1152         for (i = 0; i < mw_count; i++) {
1153                 mw = &nt->mw_vec[i];
1154
1155                 rc = ntb_peer_mw_get_addr(ndev, i, &mw->phys_addr,
1156                                           &mw->phys_size);
1157                 if (rc)
1158                         goto err1;
1159
1160                 mw->vbase = ioremap_wc(mw->phys_addr, mw->phys_size);
1161                 if (!mw->vbase) {
1162                         rc = -ENOMEM;
1163                         goto err1;
1164                 }
1165
1166                 mw->buff_size = 0;
1167                 mw->xlat_size = 0;
1168                 mw->virt_addr = NULL;
1169                 mw->dma_addr = 0;
1170         }
1171
1172         qp_bitmap = ntb_db_valid_mask(ndev);
1173
1174         qp_count = ilog2(qp_bitmap);
1175         if (max_num_clients && max_num_clients < qp_count)
1176                 qp_count = max_num_clients;
1177         else if (nt->mw_count < qp_count)
1178                 qp_count = nt->mw_count;
1179
1180         qp_bitmap &= BIT_ULL(qp_count) - 1;
1181
1182         nt->qp_count = qp_count;
1183         nt->qp_bitmap = qp_bitmap;
1184         nt->qp_bitmap_free = qp_bitmap;
1185
1186         nt->qp_vec = kcalloc_node(qp_count, sizeof(*nt->qp_vec),
1187                                   GFP_KERNEL, node);
1188         if (!nt->qp_vec) {
1189                 rc = -ENOMEM;
1190                 goto err1;
1191         }
1192
1193         if (nt_debugfs_dir) {
1194                 nt->debugfs_node_dir =
1195                         debugfs_create_dir(pci_name(ndev->pdev),
1196                                            nt_debugfs_dir);
1197         }
1198
1199         for (i = 0; i < qp_count; i++) {
1200                 rc = ntb_transport_init_queue(nt, i);
1201                 if (rc)
1202                         goto err2;
1203         }
1204
1205         INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work);
1206         INIT_WORK(&nt->link_cleanup, ntb_transport_link_cleanup_work);
1207
1208         rc = ntb_set_ctx(ndev, nt, &ntb_transport_ops);
1209         if (rc)
1210                 goto err2;
1211
1212         INIT_LIST_HEAD(&nt->client_devs);
1213         rc = ntb_bus_init(nt);
1214         if (rc)
1215                 goto err3;
1216
1217         nt->link_is_up = false;
1218         ntb_link_enable(ndev, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
1219         ntb_link_event(ndev);
1220
1221         return 0;
1222
1223 err3:
1224         ntb_clear_ctx(ndev);
1225 err2:
1226         kfree(nt->qp_vec);
1227 err1:
1228         while (i--) {
1229                 mw = &nt->mw_vec[i];
1230                 iounmap(mw->vbase);
1231         }
1232         kfree(nt->mw_vec);
1233 err:
1234         kfree(nt);
1235         return rc;
1236 }
1237
1238 static void ntb_transport_free(struct ntb_client *self, struct ntb_dev *ndev)
1239 {
1240         struct ntb_transport_ctx *nt = ndev->ctx;
1241         struct ntb_transport_qp *qp;
1242         u64 qp_bitmap_alloc;
1243         int i;
1244
1245         ntb_transport_link_cleanup(nt);
1246         cancel_work_sync(&nt->link_cleanup);
1247         cancel_delayed_work_sync(&nt->link_work);
1248
1249         qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
1250
1251         /* verify that all the qp's are freed */
1252         for (i = 0; i < nt->qp_count; i++) {
1253                 qp = &nt->qp_vec[i];
1254                 if (qp_bitmap_alloc & BIT_ULL(i))
1255                         ntb_transport_free_queue(qp);
1256                 debugfs_remove_recursive(qp->debugfs_dir);
1257         }
1258
1259         ntb_link_disable(ndev);
1260         ntb_clear_ctx(ndev);
1261
1262         ntb_bus_remove(nt);
1263
1264         for (i = nt->mw_count; i--; ) {
1265                 ntb_free_mw(nt, i);
1266                 iounmap(nt->mw_vec[i].vbase);
1267         }
1268
1269         kfree(nt->qp_vec);
1270         kfree(nt->mw_vec);
1271         kfree(nt);
1272 }
1273
1274 static void ntb_complete_rxc(struct ntb_transport_qp *qp)
1275 {
1276         struct ntb_queue_entry *entry;
1277         void *cb_data;
1278         unsigned int len;
1279         unsigned long irqflags;
1280
1281         spin_lock_irqsave(&qp->ntb_rx_q_lock, irqflags);
1282
1283         while (!list_empty(&qp->rx_post_q)) {
1284                 entry = list_first_entry(&qp->rx_post_q,
1285                                          struct ntb_queue_entry, entry);
1286                 if (!(entry->flags & DESC_DONE_FLAG))
1287                         break;
1288
1289                 entry->rx_hdr->flags = 0;
1290                 iowrite32(entry->rx_index, &qp->rx_info->entry);
1291
1292                 cb_data = entry->cb_data;
1293                 len = entry->len;
1294
1295                 list_move_tail(&entry->entry, &qp->rx_free_q);
1296
1297                 spin_unlock_irqrestore(&qp->ntb_rx_q_lock, irqflags);
1298
1299                 if (qp->rx_handler && qp->client_ready)
1300                         qp->rx_handler(qp, qp->cb_data, cb_data, len);
1301
1302                 spin_lock_irqsave(&qp->ntb_rx_q_lock, irqflags);
1303         }
1304
1305         spin_unlock_irqrestore(&qp->ntb_rx_q_lock, irqflags);
1306 }
1307
1308 static void ntb_rx_copy_callback(void *data,
1309                                  const struct dmaengine_result *res)
1310 {
1311         struct ntb_queue_entry *entry = data;
1312
1313         /* we need to check DMA results if we are using DMA */
1314         if (res) {
1315                 enum dmaengine_tx_result dma_err = res->result;
1316
1317                 switch (dma_err) {
1318                 case DMA_TRANS_READ_FAILED:
1319                 case DMA_TRANS_WRITE_FAILED:
1320                         entry->errors++;
1321                         /* fall through */
1322                 case DMA_TRANS_ABORTED:
1323                 {
1324                         struct ntb_transport_qp *qp = entry->qp;
1325                         void *offset = qp->rx_buff + qp->rx_max_frame *
1326                                         qp->rx_index;
1327
1328                         ntb_memcpy_rx(entry, offset);
1329                         qp->rx_memcpy++;
1330                         return;
1331                 }
1332
1333                 case DMA_TRANS_NOERROR:
1334                 default:
1335                         break;
1336                 }
1337         }
1338
1339         entry->flags |= DESC_DONE_FLAG;
1340
1341         ntb_complete_rxc(entry->qp);
1342 }
1343
1344 static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void *offset)
1345 {
1346         void *buf = entry->buf;
1347         size_t len = entry->len;
1348
1349         memcpy(buf, offset, len);
1350
1351         /* Ensure that the data is fully copied out before clearing the flag */
1352         wmb();
1353
1354         ntb_rx_copy_callback(entry, NULL);
1355 }
1356
1357 static int ntb_async_rx_submit(struct ntb_queue_entry *entry, void *offset)
1358 {
1359         struct dma_async_tx_descriptor *txd;
1360         struct ntb_transport_qp *qp = entry->qp;
1361         struct dma_chan *chan = qp->rx_dma_chan;
1362         struct dma_device *device;
1363         size_t pay_off, buff_off, len;
1364         struct dmaengine_unmap_data *unmap;
1365         dma_cookie_t cookie;
1366         void *buf = entry->buf;
1367
1368         len = entry->len;
1369         device = chan->device;
1370         pay_off = (size_t)offset & ~PAGE_MASK;
1371         buff_off = (size_t)buf & ~PAGE_MASK;
1372
1373         if (!is_dma_copy_aligned(device, pay_off, buff_off, len))
1374                 goto err;
1375
1376         unmap = dmaengine_get_unmap_data(device->dev, 2, GFP_NOWAIT);
1377         if (!unmap)
1378                 goto err;
1379
1380         unmap->len = len;
1381         unmap->addr[0] = dma_map_page(device->dev, virt_to_page(offset),
1382                                       pay_off, len, DMA_TO_DEVICE);
1383         if (dma_mapping_error(device->dev, unmap->addr[0]))
1384                 goto err_get_unmap;
1385
1386         unmap->to_cnt = 1;
1387
1388         unmap->addr[1] = dma_map_page(device->dev, virt_to_page(buf),
1389                                       buff_off, len, DMA_FROM_DEVICE);
1390         if (dma_mapping_error(device->dev, unmap->addr[1]))
1391                 goto err_get_unmap;
1392
1393         unmap->from_cnt = 1;
1394
1395         txd = device->device_prep_dma_memcpy(chan, unmap->addr[1],
1396                                              unmap->addr[0], len,
1397                                              DMA_PREP_INTERRUPT);
1398         if (!txd)
1399                 goto err_get_unmap;
1400
1401         txd->callback_result = ntb_rx_copy_callback;
1402         txd->callback_param = entry;
1403         dma_set_unmap(txd, unmap);
1404
1405         cookie = dmaengine_submit(txd);
1406         if (dma_submit_error(cookie))
1407                 goto err_set_unmap;
1408
1409         dmaengine_unmap_put(unmap);
1410
1411         qp->last_cookie = cookie;
1412
1413         qp->rx_async++;
1414
1415         return 0;
1416
1417 err_set_unmap:
1418         dmaengine_unmap_put(unmap);
1419 err_get_unmap:
1420         dmaengine_unmap_put(unmap);
1421 err:
1422         return -ENXIO;
1423 }
1424
1425 static void ntb_async_rx(struct ntb_queue_entry *entry, void *offset)
1426 {
1427         struct ntb_transport_qp *qp = entry->qp;
1428         struct dma_chan *chan = qp->rx_dma_chan;
1429         int res;
1430
1431         if (!chan)
1432                 goto err;
1433
1434         if (entry->len < copy_bytes)
1435                 goto err;
1436
1437         res = ntb_async_rx_submit(entry, offset);
1438         if (res < 0)
1439                 goto err;
1440
1441         if (!entry->retries)
1442                 qp->rx_async++;
1443
1444         return;
1445
1446 err:
1447         ntb_memcpy_rx(entry, offset);
1448         qp->rx_memcpy++;
1449 }
1450
1451 static int ntb_process_rxc(struct ntb_transport_qp *qp)
1452 {
1453         struct ntb_payload_header *hdr;
1454         struct ntb_queue_entry *entry;
1455         void *offset;
1456
1457         offset = qp->rx_buff + qp->rx_max_frame * qp->rx_index;
1458         hdr = offset + qp->rx_max_frame - sizeof(struct ntb_payload_header);
1459
1460         dev_dbg(&qp->ndev->pdev->dev, "qp %d: RX ver %u len %d flags %x\n",
1461                 qp->qp_num, hdr->ver, hdr->len, hdr->flags);
1462
1463         if (!(hdr->flags & DESC_DONE_FLAG)) {
1464                 dev_dbg(&qp->ndev->pdev->dev, "done flag not set\n");
1465                 qp->rx_ring_empty++;
1466                 return -EAGAIN;
1467         }
1468
1469         if (hdr->flags & LINK_DOWN_FLAG) {
1470                 dev_dbg(&qp->ndev->pdev->dev, "link down flag set\n");
1471                 ntb_qp_link_down(qp);
1472                 hdr->flags = 0;
1473                 return -EAGAIN;
1474         }
1475
1476         if (hdr->ver != (u32)qp->rx_pkts) {
1477                 dev_dbg(&qp->ndev->pdev->dev,
1478                         "version mismatch, expected %llu - got %u\n",
1479                         qp->rx_pkts, hdr->ver);
1480                 qp->rx_err_ver++;
1481                 return -EIO;
1482         }
1483
1484         entry = ntb_list_mv(&qp->ntb_rx_q_lock, &qp->rx_pend_q, &qp->rx_post_q);
1485         if (!entry) {
1486                 dev_dbg(&qp->ndev->pdev->dev, "no receive buffer\n");
1487                 qp->rx_err_no_buf++;
1488                 return -EAGAIN;
1489         }
1490
1491         entry->rx_hdr = hdr;
1492         entry->rx_index = qp->rx_index;
1493
1494         if (hdr->len > entry->len) {
1495                 dev_dbg(&qp->ndev->pdev->dev,
1496                         "receive buffer overflow! Wanted %d got %d\n",
1497                         hdr->len, entry->len);
1498                 qp->rx_err_oflow++;
1499
1500                 entry->len = -EIO;
1501                 entry->flags |= DESC_DONE_FLAG;
1502
1503                 ntb_complete_rxc(qp);
1504         } else {
1505                 dev_dbg(&qp->ndev->pdev->dev,
1506                         "RX OK index %u ver %u size %d into buf size %d\n",
1507                         qp->rx_index, hdr->ver, hdr->len, entry->len);
1508
1509                 qp->rx_bytes += hdr->len;
1510                 qp->rx_pkts++;
1511
1512                 entry->len = hdr->len;
1513
1514                 ntb_async_rx(entry, offset);
1515         }
1516
1517         qp->rx_index++;
1518         qp->rx_index %= qp->rx_max_entry;
1519
1520         return 0;
1521 }
1522
1523 static void ntb_transport_rxc_db(unsigned long data)
1524 {
1525         struct ntb_transport_qp *qp = (void *)data;
1526         int rc, i;
1527
1528         dev_dbg(&qp->ndev->pdev->dev, "%s: doorbell %d received\n",
1529                 __func__, qp->qp_num);
1530
1531         /* Limit the number of packets processed in a single interrupt to
1532          * provide fairness to others
1533          */
1534         for (i = 0; i < qp->rx_max_entry; i++) {
1535                 rc = ntb_process_rxc(qp);
1536                 if (rc)
1537                         break;
1538         }
1539
1540         if (i && qp->rx_dma_chan)
1541                 dma_async_issue_pending(qp->rx_dma_chan);
1542
1543         if (i == qp->rx_max_entry) {
1544                 /* there is more work to do */
1545                 if (qp->active)
1546                         tasklet_schedule(&qp->rxc_db_work);
1547         } else if (ntb_db_read(qp->ndev) & BIT_ULL(qp->qp_num)) {
1548                 /* the doorbell bit is set: clear it */
1549                 ntb_db_clear(qp->ndev, BIT_ULL(qp->qp_num));
1550                 /* ntb_db_read ensures ntb_db_clear write is committed */
1551                 ntb_db_read(qp->ndev);
1552
1553                 /* an interrupt may have arrived between finishing
1554                  * ntb_process_rxc and clearing the doorbell bit:
1555                  * there might be some more work to do.
1556                  */
1557                 if (qp->active)
1558                         tasklet_schedule(&qp->rxc_db_work);
1559         }
1560 }
1561
1562 static void ntb_tx_copy_callback(void *data,
1563                                  const struct dmaengine_result *res)
1564 {
1565         struct ntb_queue_entry *entry = data;
1566         struct ntb_transport_qp *qp = entry->qp;
1567         struct ntb_payload_header __iomem *hdr = entry->tx_hdr;
1568
1569         /* we need to check DMA results if we are using DMA */
1570         if (res) {
1571                 enum dmaengine_tx_result dma_err = res->result;
1572
1573                 switch (dma_err) {
1574                 case DMA_TRANS_READ_FAILED:
1575                 case DMA_TRANS_WRITE_FAILED:
1576                         entry->errors++;
1577                         /* fall through */
1578                 case DMA_TRANS_ABORTED:
1579                 {
1580                         void __iomem *offset =
1581                                 qp->tx_mw + qp->tx_max_frame *
1582                                 entry->tx_index;
1583
1584                         /* resubmit via CPU */
1585                         ntb_memcpy_tx(entry, offset);
1586                         qp->tx_memcpy++;
1587                         return;
1588                 }
1589
1590                 case DMA_TRANS_NOERROR:
1591                 default:
1592                         break;
1593                 }
1594         }
1595
1596         iowrite32(entry->flags | DESC_DONE_FLAG, &hdr->flags);
1597
1598         ntb_peer_db_set(qp->ndev, BIT_ULL(qp->qp_num));
1599
1600         /* The entry length can only be zero if the packet is intended to be a
1601          * "link down" or similar.  Since no payload is being sent in these
1602          * cases, there is nothing to add to the completion queue.
1603          */
1604         if (entry->len > 0) {
1605                 qp->tx_bytes += entry->len;
1606
1607                 if (qp->tx_handler)
1608                         qp->tx_handler(qp, qp->cb_data, entry->cb_data,
1609                                        entry->len);
1610         }
1611
1612         ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q);
1613 }
1614
1615 static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset)
1616 {
1617 #ifdef ARCH_HAS_NOCACHE_UACCESS
1618         /*
1619          * Using non-temporal mov to improve performance on non-cached
1620          * writes, even though we aren't actually copying from user space.
1621          */
1622         __copy_from_user_inatomic_nocache(offset, entry->buf, entry->len);
1623 #else
1624         memcpy_toio(offset, entry->buf, entry->len);
1625 #endif
1626
1627         /* Ensure that the data is fully copied out before setting the flags */
1628         wmb();
1629
1630         ntb_tx_copy_callback(entry, NULL);
1631 }
1632
1633 static int ntb_async_tx_submit(struct ntb_transport_qp *qp,
1634                                struct ntb_queue_entry *entry)
1635 {
1636         struct dma_async_tx_descriptor *txd;
1637         struct dma_chan *chan = qp->tx_dma_chan;
1638         struct dma_device *device;
1639         size_t len = entry->len;
1640         void *buf = entry->buf;
1641         size_t dest_off, buff_off;
1642         struct dmaengine_unmap_data *unmap;
1643         dma_addr_t dest;
1644         dma_cookie_t cookie;
1645
1646         device = chan->device;
1647         dest = qp->tx_mw_phys + qp->tx_max_frame * entry->tx_index;
1648         buff_off = (size_t)buf & ~PAGE_MASK;
1649         dest_off = (size_t)dest & ~PAGE_MASK;
1650
1651         if (!is_dma_copy_aligned(device, buff_off, dest_off, len))
1652                 goto err;
1653
1654         unmap = dmaengine_get_unmap_data(device->dev, 1, GFP_NOWAIT);
1655         if (!unmap)
1656                 goto err;
1657
1658         unmap->len = len;
1659         unmap->addr[0] = dma_map_page(device->dev, virt_to_page(buf),
1660                                       buff_off, len, DMA_TO_DEVICE);
1661         if (dma_mapping_error(device->dev, unmap->addr[0]))
1662                 goto err_get_unmap;
1663
1664         unmap->to_cnt = 1;
1665
1666         txd = device->device_prep_dma_memcpy(chan, dest, unmap->addr[0], len,
1667                                              DMA_PREP_INTERRUPT);
1668         if (!txd)
1669                 goto err_get_unmap;
1670
1671         txd->callback_result = ntb_tx_copy_callback;
1672         txd->callback_param = entry;
1673         dma_set_unmap(txd, unmap);
1674
1675         cookie = dmaengine_submit(txd);
1676         if (dma_submit_error(cookie))
1677                 goto err_set_unmap;
1678
1679         dmaengine_unmap_put(unmap);
1680
1681         dma_async_issue_pending(chan);
1682
1683         return 0;
1684 err_set_unmap:
1685         dmaengine_unmap_put(unmap);
1686 err_get_unmap:
1687         dmaengine_unmap_put(unmap);
1688 err:
1689         return -ENXIO;
1690 }
1691
1692 static void ntb_async_tx(struct ntb_transport_qp *qp,
1693                          struct ntb_queue_entry *entry)
1694 {
1695         struct ntb_payload_header __iomem *hdr;
1696         struct dma_chan *chan = qp->tx_dma_chan;
1697         void __iomem *offset;
1698         int res;
1699
1700         entry->tx_index = qp->tx_index;
1701         offset = qp->tx_mw + qp->tx_max_frame * entry->tx_index;
1702         hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
1703         entry->tx_hdr = hdr;
1704
1705         iowrite32(entry->len, &hdr->len);
1706         iowrite32((u32)qp->tx_pkts, &hdr->ver);
1707
1708         if (!chan)
1709                 goto err;
1710
1711         if (entry->len < copy_bytes)
1712                 goto err;
1713
1714         res = ntb_async_tx_submit(qp, entry);
1715         if (res < 0)
1716                 goto err;
1717
1718         if (!entry->retries)
1719                 qp->tx_async++;
1720
1721         return;
1722
1723 err:
1724         ntb_memcpy_tx(entry, offset);
1725         qp->tx_memcpy++;
1726 }
1727
1728 static int ntb_process_tx(struct ntb_transport_qp *qp,
1729                           struct ntb_queue_entry *entry)
1730 {
1731         if (qp->tx_index == qp->remote_rx_info->entry) {
1732                 qp->tx_ring_full++;
1733                 return -EAGAIN;
1734         }
1735
1736         if (entry->len > qp->tx_max_frame - sizeof(struct ntb_payload_header)) {
1737                 if (qp->tx_handler)
1738                         qp->tx_handler(qp, qp->cb_data, NULL, -EIO);
1739
1740                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1741                              &qp->tx_free_q);
1742                 return 0;
1743         }
1744
1745         ntb_async_tx(qp, entry);
1746
1747         qp->tx_index++;
1748         qp->tx_index %= qp->tx_max_entry;
1749
1750         qp->tx_pkts++;
1751
1752         return 0;
1753 }
1754
1755 static void ntb_send_link_down(struct ntb_transport_qp *qp)
1756 {
1757         struct pci_dev *pdev = qp->ndev->pdev;
1758         struct ntb_queue_entry *entry;
1759         int i, rc;
1760
1761         if (!qp->link_is_up)
1762                 return;
1763
1764         dev_info(&pdev->dev, "qp %d: Send Link Down\n", qp->qp_num);
1765
1766         for (i = 0; i < NTB_LINK_DOWN_TIMEOUT; i++) {
1767                 entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1768                 if (entry)
1769                         break;
1770                 msleep(100);
1771         }
1772
1773         if (!entry)
1774                 return;
1775
1776         entry->cb_data = NULL;
1777         entry->buf = NULL;
1778         entry->len = 0;
1779         entry->flags = LINK_DOWN_FLAG;
1780
1781         rc = ntb_process_tx(qp, entry);
1782         if (rc)
1783                 dev_err(&pdev->dev, "ntb: QP%d unable to send linkdown msg\n",
1784                         qp->qp_num);
1785
1786         ntb_qp_link_down_reset(qp);
1787 }
1788
1789 static bool ntb_dma_filter_fn(struct dma_chan *chan, void *node)
1790 {
1791         return dev_to_node(&chan->dev->device) == (int)(unsigned long)node;
1792 }
1793
1794 /**
1795  * ntb_transport_create_queue - Create a new NTB transport layer queue
1796  * @rx_handler: receive callback function
1797  * @tx_handler: transmit callback function
1798  * @event_handler: event callback function
1799  *
1800  * Create a new NTB transport layer queue and provide the queue with a callback
1801  * routine for both transmit and receive.  The receive callback routine will be
1802  * used to pass up data when the transport has received it on the queue.   The
1803  * transmit callback routine will be called when the transport has completed the
1804  * transmission of the data on the queue and the data is ready to be freed.
1805  *
1806  * RETURNS: pointer to newly created ntb_queue, NULL on error.
1807  */
1808 struct ntb_transport_qp *
1809 ntb_transport_create_queue(void *data, struct device *client_dev,
1810                            const struct ntb_queue_handlers *handlers)
1811 {
1812         struct ntb_dev *ndev;
1813         struct pci_dev *pdev;
1814         struct ntb_transport_ctx *nt;
1815         struct ntb_queue_entry *entry;
1816         struct ntb_transport_qp *qp;
1817         u64 qp_bit;
1818         unsigned int free_queue;
1819         dma_cap_mask_t dma_mask;
1820         int node;
1821         int i;
1822
1823         ndev = dev_ntb(client_dev->parent);
1824         pdev = ndev->pdev;
1825         nt = ndev->ctx;
1826
1827         node = dev_to_node(&ndev->dev);
1828
1829         free_queue = ffs(nt->qp_bitmap_free);
1830         if (!free_queue)
1831                 goto err;
1832
1833         /* decrement free_queue to make it zero based */
1834         free_queue--;
1835
1836         qp = &nt->qp_vec[free_queue];
1837         qp_bit = BIT_ULL(qp->qp_num);
1838
1839         nt->qp_bitmap_free &= ~qp_bit;
1840
1841         qp->cb_data = data;
1842         qp->rx_handler = handlers->rx_handler;
1843         qp->tx_handler = handlers->tx_handler;
1844         qp->event_handler = handlers->event_handler;
1845
1846         dma_cap_zero(dma_mask);
1847         dma_cap_set(DMA_MEMCPY, dma_mask);
1848
1849         if (use_dma) {
1850                 qp->tx_dma_chan =
1851                         dma_request_channel(dma_mask, ntb_dma_filter_fn,
1852                                             (void *)(unsigned long)node);
1853                 if (!qp->tx_dma_chan)
1854                         dev_info(&pdev->dev, "Unable to allocate TX DMA channel\n");
1855
1856                 qp->rx_dma_chan =
1857                         dma_request_channel(dma_mask, ntb_dma_filter_fn,
1858                                             (void *)(unsigned long)node);
1859                 if (!qp->rx_dma_chan)
1860                         dev_info(&pdev->dev, "Unable to allocate RX DMA channel\n");
1861         } else {
1862                 qp->tx_dma_chan = NULL;
1863                 qp->rx_dma_chan = NULL;
1864         }
1865
1866         dev_dbg(&pdev->dev, "Using %s memcpy for TX\n",
1867                 qp->tx_dma_chan ? "DMA" : "CPU");
1868
1869         dev_dbg(&pdev->dev, "Using %s memcpy for RX\n",
1870                 qp->rx_dma_chan ? "DMA" : "CPU");
1871
1872         for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
1873                 entry = kzalloc_node(sizeof(*entry), GFP_KERNEL, node);
1874                 if (!entry)
1875                         goto err1;
1876
1877                 entry->qp = qp;
1878                 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry,
1879                              &qp->rx_free_q);
1880         }
1881         qp->rx_alloc_entry = NTB_QP_DEF_NUM_ENTRIES;
1882
1883         for (i = 0; i < qp->tx_max_entry; i++) {
1884                 entry = kzalloc_node(sizeof(*entry), GFP_KERNEL, node);
1885                 if (!entry)
1886                         goto err2;
1887
1888                 entry->qp = qp;
1889                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1890                              &qp->tx_free_q);
1891         }
1892
1893         ntb_db_clear(qp->ndev, qp_bit);
1894         ntb_db_clear_mask(qp->ndev, qp_bit);
1895
1896         dev_info(&pdev->dev, "NTB Transport QP %d created\n", qp->qp_num);
1897
1898         return qp;
1899
1900 err2:
1901         while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1902                 kfree(entry);
1903 err1:
1904         qp->rx_alloc_entry = 0;
1905         while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
1906                 kfree(entry);
1907         if (qp->tx_dma_chan)
1908                 dma_release_channel(qp->tx_dma_chan);
1909         if (qp->rx_dma_chan)
1910                 dma_release_channel(qp->rx_dma_chan);
1911         nt->qp_bitmap_free |= qp_bit;
1912 err:
1913         return NULL;
1914 }
1915 EXPORT_SYMBOL_GPL(ntb_transport_create_queue);
1916
1917 /**
1918  * ntb_transport_free_queue - Frees NTB transport queue
1919  * @qp: NTB queue to be freed
1920  *
1921  * Frees NTB transport queue
1922  */
1923 void ntb_transport_free_queue(struct ntb_transport_qp *qp)
1924 {
1925         struct pci_dev *pdev;
1926         struct ntb_queue_entry *entry;
1927         u64 qp_bit;
1928
1929         if (!qp)
1930                 return;
1931
1932         pdev = qp->ndev->pdev;
1933
1934         qp->active = false;
1935
1936         if (qp->tx_dma_chan) {
1937                 struct dma_chan *chan = qp->tx_dma_chan;
1938                 /* Putting the dma_chan to NULL will force any new traffic to be
1939                  * processed by the CPU instead of the DAM engine
1940                  */
1941                 qp->tx_dma_chan = NULL;
1942
1943                 /* Try to be nice and wait for any queued DMA engine
1944                  * transactions to process before smashing it with a rock
1945                  */
1946                 dma_sync_wait(chan, qp->last_cookie);
1947                 dmaengine_terminate_all(chan);
1948                 dma_release_channel(chan);
1949         }
1950
1951         if (qp->rx_dma_chan) {
1952                 struct dma_chan *chan = qp->rx_dma_chan;
1953                 /* Putting the dma_chan to NULL will force any new traffic to be
1954                  * processed by the CPU instead of the DAM engine
1955                  */
1956                 qp->rx_dma_chan = NULL;
1957
1958                 /* Try to be nice and wait for any queued DMA engine
1959                  * transactions to process before smashing it with a rock
1960                  */
1961                 dma_sync_wait(chan, qp->last_cookie);
1962                 dmaengine_terminate_all(chan);
1963                 dma_release_channel(chan);
1964         }
1965
1966         qp_bit = BIT_ULL(qp->qp_num);
1967
1968         ntb_db_set_mask(qp->ndev, qp_bit);
1969         tasklet_kill(&qp->rxc_db_work);
1970
1971         cancel_delayed_work_sync(&qp->link_work);
1972
1973         qp->cb_data = NULL;
1974         qp->rx_handler = NULL;
1975         qp->tx_handler = NULL;
1976         qp->event_handler = NULL;
1977
1978         while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
1979                 kfree(entry);
1980
1981         while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_pend_q))) {
1982                 dev_warn(&pdev->dev, "Freeing item from non-empty rx_pend_q\n");
1983                 kfree(entry);
1984         }
1985
1986         while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_post_q))) {
1987                 dev_warn(&pdev->dev, "Freeing item from non-empty rx_post_q\n");
1988                 kfree(entry);
1989         }
1990
1991         while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1992                 kfree(entry);
1993
1994         qp->transport->qp_bitmap_free |= qp_bit;
1995
1996         dev_info(&pdev->dev, "NTB Transport QP %d freed\n", qp->qp_num);
1997 }
1998 EXPORT_SYMBOL_GPL(ntb_transport_free_queue);
1999
2000 /**
2001  * ntb_transport_rx_remove - Dequeues enqueued rx packet
2002  * @qp: NTB queue to be freed
2003  * @len: pointer to variable to write enqueued buffers length
2004  *
2005  * Dequeues unused buffers from receive queue.  Should only be used during
2006  * shutdown of qp.
2007  *
2008  * RETURNS: NULL error value on error, or void* for success.
2009  */
2010 void *ntb_transport_rx_remove(struct ntb_transport_qp *qp, unsigned int *len)
2011 {
2012         struct ntb_queue_entry *entry;
2013         void *buf;
2014
2015         if (!qp || qp->client_ready)
2016                 return NULL;
2017
2018         entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_pend_q);
2019         if (!entry)
2020                 return NULL;
2021
2022         buf = entry->cb_data;
2023         *len = entry->len;
2024
2025         ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_free_q);
2026
2027         return buf;
2028 }
2029 EXPORT_SYMBOL_GPL(ntb_transport_rx_remove);
2030
2031 /**
2032  * ntb_transport_rx_enqueue - Enqueue a new NTB queue entry
2033  * @qp: NTB transport layer queue the entry is to be enqueued on
2034  * @cb: per buffer pointer for callback function to use
2035  * @data: pointer to data buffer that incoming packets will be copied into
2036  * @len: length of the data buffer
2037  *
2038  * Enqueue a new receive buffer onto the transport queue into which a NTB
2039  * payload can be received into.
2040  *
2041  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
2042  */
2043 int ntb_transport_rx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
2044                              unsigned int len)
2045 {
2046         struct ntb_queue_entry *entry;
2047
2048         if (!qp)
2049                 return -EINVAL;
2050
2051         entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q);
2052         if (!entry)
2053                 return -ENOMEM;
2054
2055         entry->cb_data = cb;
2056         entry->buf = data;
2057         entry->len = len;
2058         entry->flags = 0;
2059         entry->retries = 0;
2060         entry->errors = 0;
2061         entry->rx_index = 0;
2062
2063         ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_pend_q);
2064
2065         if (qp->active)
2066                 tasklet_schedule(&qp->rxc_db_work);
2067
2068         return 0;
2069 }
2070 EXPORT_SYMBOL_GPL(ntb_transport_rx_enqueue);
2071
2072 /**
2073  * ntb_transport_tx_enqueue - Enqueue a new NTB queue entry
2074  * @qp: NTB transport layer queue the entry is to be enqueued on
2075  * @cb: per buffer pointer for callback function to use
2076  * @data: pointer to data buffer that will be sent
2077  * @len: length of the data buffer
2078  *
2079  * Enqueue a new transmit buffer onto the transport queue from which a NTB
2080  * payload will be transmitted.  This assumes that a lock is being held to
2081  * serialize access to the qp.
2082  *
2083  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
2084  */
2085 int ntb_transport_tx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
2086                              unsigned int len)
2087 {
2088         struct ntb_queue_entry *entry;
2089         int rc;
2090
2091         if (!qp || !qp->link_is_up || !len)
2092                 return -EINVAL;
2093
2094         entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
2095         if (!entry) {
2096                 qp->tx_err_no_buf++;
2097                 return -EBUSY;
2098         }
2099
2100         entry->cb_data = cb;
2101         entry->buf = data;
2102         entry->len = len;
2103         entry->flags = 0;
2104         entry->errors = 0;
2105         entry->retries = 0;
2106         entry->tx_index = 0;
2107
2108         rc = ntb_process_tx(qp, entry);
2109         if (rc)
2110                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
2111                              &qp->tx_free_q);
2112
2113         return rc;
2114 }
2115 EXPORT_SYMBOL_GPL(ntb_transport_tx_enqueue);
2116
2117 /**
2118  * ntb_transport_link_up - Notify NTB transport of client readiness to use queue
2119  * @qp: NTB transport layer queue to be enabled
2120  *
2121  * Notify NTB transport layer of client readiness to use queue
2122  */
2123 void ntb_transport_link_up(struct ntb_transport_qp *qp)
2124 {
2125         if (!qp)
2126                 return;
2127
2128         qp->client_ready = true;
2129
2130         if (qp->transport->link_is_up)
2131                 schedule_delayed_work(&qp->link_work, 0);
2132 }
2133 EXPORT_SYMBOL_GPL(ntb_transport_link_up);
2134
2135 /**
2136  * ntb_transport_link_down - Notify NTB transport to no longer enqueue data
2137  * @qp: NTB transport layer queue to be disabled
2138  *
2139  * Notify NTB transport layer of client's desire to no longer receive data on
2140  * transport queue specified.  It is the client's responsibility to ensure all
2141  * entries on queue are purged or otherwise handled appropriately.
2142  */
2143 void ntb_transport_link_down(struct ntb_transport_qp *qp)
2144 {
2145         int val;
2146
2147         if (!qp)
2148                 return;
2149
2150         qp->client_ready = false;
2151
2152         val = ntb_spad_read(qp->ndev, QP_LINKS);
2153
2154         ntb_peer_spad_write(qp->ndev, PIDX, QP_LINKS, val & ~BIT(qp->qp_num));
2155
2156         if (qp->link_is_up)
2157                 ntb_send_link_down(qp);
2158         else
2159                 cancel_delayed_work_sync(&qp->link_work);
2160 }
2161 EXPORT_SYMBOL_GPL(ntb_transport_link_down);
2162
2163 /**
2164  * ntb_transport_link_query - Query transport link state
2165  * @qp: NTB transport layer queue to be queried
2166  *
2167  * Query connectivity to the remote system of the NTB transport queue
2168  *
2169  * RETURNS: true for link up or false for link down
2170  */
2171 bool ntb_transport_link_query(struct ntb_transport_qp *qp)
2172 {
2173         if (!qp)
2174                 return false;
2175
2176         return qp->link_is_up;
2177 }
2178 EXPORT_SYMBOL_GPL(ntb_transport_link_query);
2179
2180 /**
2181  * ntb_transport_qp_num - Query the qp number
2182  * @qp: NTB transport layer queue to be queried
2183  *
2184  * Query qp number of the NTB transport queue
2185  *
2186  * RETURNS: a zero based number specifying the qp number
2187  */
2188 unsigned char ntb_transport_qp_num(struct ntb_transport_qp *qp)
2189 {
2190         if (!qp)
2191                 return 0;
2192
2193         return qp->qp_num;
2194 }
2195 EXPORT_SYMBOL_GPL(ntb_transport_qp_num);
2196
2197 /**
2198  * ntb_transport_max_size - Query the max payload size of a qp
2199  * @qp: NTB transport layer queue to be queried
2200  *
2201  * Query the maximum payload size permissible on the given qp
2202  *
2203  * RETURNS: the max payload size of a qp
2204  */
2205 unsigned int ntb_transport_max_size(struct ntb_transport_qp *qp)
2206 {
2207         unsigned int max_size;
2208         unsigned int copy_align;
2209         struct dma_chan *rx_chan, *tx_chan;
2210
2211         if (!qp)
2212                 return 0;
2213
2214         rx_chan = qp->rx_dma_chan;
2215         tx_chan = qp->tx_dma_chan;
2216
2217         copy_align = max(rx_chan ? rx_chan->device->copy_align : 0,
2218                          tx_chan ? tx_chan->device->copy_align : 0);
2219
2220         /* If DMA engine usage is possible, try to find the max size for that */
2221         max_size = qp->tx_max_frame - sizeof(struct ntb_payload_header);
2222         max_size = round_down(max_size, 1 << copy_align);
2223
2224         return max_size;
2225 }
2226 EXPORT_SYMBOL_GPL(ntb_transport_max_size);
2227
2228 unsigned int ntb_transport_tx_free_entry(struct ntb_transport_qp *qp)
2229 {
2230         unsigned int head = qp->tx_index;
2231         unsigned int tail = qp->remote_rx_info->entry;
2232
2233         return tail > head ? tail - head : qp->tx_max_entry + tail - head;
2234 }
2235 EXPORT_SYMBOL_GPL(ntb_transport_tx_free_entry);
2236
2237 static void ntb_transport_doorbell_callback(void *data, int vector)
2238 {
2239         struct ntb_transport_ctx *nt = data;
2240         struct ntb_transport_qp *qp;
2241         u64 db_bits;
2242         unsigned int qp_num;
2243
2244         db_bits = (nt->qp_bitmap & ~nt->qp_bitmap_free &
2245                    ntb_db_vector_mask(nt->ndev, vector));
2246
2247         while (db_bits) {
2248                 qp_num = __ffs(db_bits);
2249                 qp = &nt->qp_vec[qp_num];
2250
2251                 if (qp->active)
2252                         tasklet_schedule(&qp->rxc_db_work);
2253
2254                 db_bits &= ~BIT_ULL(qp_num);
2255         }
2256 }
2257
2258 static const struct ntb_ctx_ops ntb_transport_ops = {
2259         .link_event = ntb_transport_event_callback,
2260         .db_event = ntb_transport_doorbell_callback,
2261 };
2262
2263 static struct ntb_client ntb_transport_client = {
2264         .ops = {
2265                 .probe = ntb_transport_probe,
2266                 .remove = ntb_transport_free,
2267         },
2268 };
2269
2270 static int __init ntb_transport_init(void)
2271 {
2272         int rc;
2273
2274         pr_info("%s, version %s\n", NTB_TRANSPORT_DESC, NTB_TRANSPORT_VER);
2275
2276         if (debugfs_initialized())
2277                 nt_debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
2278
2279         rc = bus_register(&ntb_transport_bus);
2280         if (rc)
2281                 goto err_bus;
2282
2283         rc = ntb_register_client(&ntb_transport_client);
2284         if (rc)
2285                 goto err_client;
2286
2287         return 0;
2288
2289 err_client:
2290         bus_unregister(&ntb_transport_bus);
2291 err_bus:
2292         debugfs_remove_recursive(nt_debugfs_dir);
2293         return rc;
2294 }
2295 module_init(ntb_transport_init);
2296
2297 static void __exit ntb_transport_exit(void)
2298 {
2299         ntb_unregister_client(&ntb_transport_client);
2300         bus_unregister(&ntb_transport_bus);
2301         debugfs_remove_recursive(nt_debugfs_dir);
2302 }
2303 module_exit(ntb_transport_exit);