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