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
  70 MODULE_DESCRIPTION(NTB_TRANSPORT_DESC);
  71 MODULE_VERSION(NTB_TRANSPORT_VER);
  72 MODULE_LICENSE("Dual BSD/GPL");
  73 MODULE_AUTHOR("Intel Corporation");
  74
  75 static unsigned long max_mw_size;
  76 module_param(max_mw_size, ulong, 0644);
  77 MODULE_PARM_DESC(max_mw_size, "Limit size of large memory windows");
  78
  79 static unsigned int transport_mtu = 0x10000;
  80 module_param(transport_mtu, uint, 0644);
  81 MODULE_PARM_DESC(transport_mtu, "Maximum size of NTB transport packets");
  82
  83 static unsigned char max_num_clients;
  84 module_param(max_num_clients, byte, 0644);
  85 MODULE_PARM_DESC(max_num_clients, "Maximum number of NTB transport clients");
  86
  87 static unsigned int copy_bytes = 1024;
  88 module_param(copy_bytes, uint, 0644);
  89 MODULE_PARM_DESC(copy_bytes, "Threshold under which NTB will use the CPU to copy instead of DMA");
  90
  91 static bool use_dma;
  92 module_param(use_dma, bool, 0644);
  93 MODULE_PARM_DESC(use_dma, "Use DMA engine to perform large data copy");
  94
  95 static struct dentry *nt_debugfs_dir;
  96
  97 struct ntb_queue_entry {
  98         /* ntb_queue list reference */
  99         struct list_head entry;
 100         /* pointers to data to be transferred */
 101         void *cb_data;
 102         void *buf;
 103         unsigned int len;
 104         unsigned int flags;
 105
 106         struct ntb_transport_qp *qp;
 107         union {
 108                 struct ntb_payload_header __iomem *tx_hdr;
 109                 struct ntb_payload_header *rx_hdr;
 110         };
 111         unsigned int index;
 112 };
 113
 114 struct ntb_rx_info {
 115         unsigned int entry;
 116 };
 117
 118 struct ntb_transport_qp {
 119         struct ntb_transport_ctx *transport;
 120         struct ntb_dev *ndev;
 121         void *cb_data;
 122         struct dma_chan *dma_chan;
 123
 124         bool client_ready;
 125         bool link_is_up;
 126
 127         u8 qp_num;      /* Only 64 QP's are allowed.  0-63 */
 128         u64 qp_bit;
 129
 130         struct ntb_rx_info __iomem *rx_info;
 131         struct ntb_rx_info *remote_rx_info;
 132
 133         void (*tx_handler)(struct ntb_transport_qp *qp, void *qp_data,
 134                            void *data, int len);
 135         struct list_head tx_free_q;
 136         spinlock_t ntb_tx_free_q_lock;
 137         void __iomem *tx_mw;
 138         dma_addr_t tx_mw_phys;
 139         unsigned int tx_index;
 140         unsigned int tx_max_entry;
 141         unsigned int tx_max_frame;
 142
 143         void (*rx_handler)(struct ntb_transport_qp *qp, void *qp_data,
 144                            void *data, int len);
 145         struct list_head rx_post_q;
 146         struct list_head rx_pend_q;
 147         struct list_head rx_free_q;
 148         /* ntb_rx_q_lock: synchronize access to rx_XXXX_q */
 149         spinlock_t ntb_rx_q_lock;
 150         void *rx_buff;
 151         unsigned int rx_index;
 152         unsigned int rx_max_entry;
 153         unsigned int rx_max_frame;
 154         dma_cookie_t last_cookie;
 155         struct tasklet_struct rxc_db_work;
 156
 157         void (*event_handler)(void *data, int status);
 158         struct delayed_work link_work;
 159         struct work_struct link_cleanup;
 160
 161         struct dentry *debugfs_dir;
 162         struct dentry *debugfs_stats;
 163
 164         /* Stats */
 165         u64 rx_bytes;
 166         u64 rx_pkts;
 167         u64 rx_ring_empty;
 168         u64 rx_err_no_buf;
 169         u64 rx_err_oflow;
 170         u64 rx_err_ver;
 171         u64 rx_memcpy;
 172         u64 rx_async;
 173         u64 tx_bytes;
 174         u64 tx_pkts;
 175         u64 tx_ring_full;
 176         u64 tx_err_no_buf;
 177         u64 tx_memcpy;
 178         u64 tx_async;
 179 };
 180
 181 struct ntb_transport_mw {
 182         phys_addr_t phys_addr;
 183         resource_size_t phys_size;
 184         resource_size_t xlat_align;
 185         resource_size_t xlat_align_size;
 186         void __iomem *vbase;
 187         size_t xlat_size;
 188         size_t buff_size;
 189         void *virt_addr;
 190         dma_addr_t dma_addr;
 191 };
 192
 193 struct ntb_transport_client_dev {
 194         struct list_head entry;
 195         struct ntb_transport_ctx *nt;
 196         struct device dev;
 197 };
 198
 199 struct ntb_transport_ctx {
 200         struct list_head entry;
 201         struct list_head client_devs;
 202
 203         struct ntb_dev *ndev;
 204
 205         struct ntb_transport_mw *mw_vec;
 206         struct ntb_transport_qp *qp_vec;
 207         unsigned int mw_count;
 208         unsigned int qp_count;
 209         u64 qp_bitmap;
 210         u64 qp_bitmap_free;
 211
 212         bool link_is_up;
 213         struct delayed_work link_work;
 214         struct work_struct link_cleanup;
 215 };
 216
 217 enum {
 218         DESC_DONE_FLAG = BIT(0),
 219         LINK_DOWN_FLAG = BIT(1),
 220 };
 221
 222 struct ntb_payload_header {
 223         unsigned int ver;
 224         unsigned int len;
 225         unsigned int flags;
 226 };
 227
 228 enum {
 229         VERSION = 0,
 230         QP_LINKS,
 231         NUM_QPS,
 232         NUM_MWS,
 233         MW0_SZ_HIGH,
 234         MW0_SZ_LOW,
 235         MW1_SZ_HIGH,
 236         MW1_SZ_LOW,
 237         MAX_SPAD,
 238 };
 239
 240 #define dev_client_dev(__dev) \
 241         container_of((__dev), struct ntb_transport_client_dev, dev)
 242
 243 #define drv_client(__drv) \
 244         container_of((__drv), struct ntb_transport_client, driver)
 245
 246 #define QP_TO_MW(nt, qp)        ((qp) % nt->mw_count)
 247 #define NTB_QP_DEF_NUM_ENTRIES  100
 248 #define NTB_LINK_DOWN_TIMEOUT   10
 249
 250 static void ntb_transport_rxc_db(unsigned long data);
 251 static const struct ntb_ctx_ops ntb_transport_ops;
 252 static struct ntb_client ntb_transport_client;
 253
 254 static int ntb_transport_bus_match(struct device *dev,
 255                                    struct device_driver *drv)
 256 {
 257         return !strncmp(dev_name(dev), drv->name, strlen(drv->name));
 258 }
 259
 260 static int ntb_transport_bus_probe(struct device *dev)
 261 {
 262         const struct ntb_transport_client *client;
 263         int rc = -EINVAL;
 264
 265         get_device(dev);
 266
 267         client = drv_client(dev->driver);
 268         rc = client->probe(dev);
 269         if (rc)
 270                 put_device(dev);
 271
 272         return rc;
 273 }
 274
 275 static int ntb_transport_bus_remove(struct device *dev)
 276 {
 277         const struct ntb_transport_client *client;
 278
 279         client = drv_client(dev->driver);
 280         client->remove(dev);
 281
 282         put_device(dev);
 283
 284         return 0;
 285 }
 286
 287 static struct bus_type ntb_transport_bus = {
 288         .name = "ntb_transport",
 289         .match = ntb_transport_bus_match,
 290         .probe = ntb_transport_bus_probe,
 291         .remove = ntb_transport_bus_remove,
 292 };
 293
 294 static LIST_HEAD(ntb_transport_list);
 295
 296 static int ntb_bus_init(struct ntb_transport_ctx *nt)
 297 {
 298         list_add(&nt->entry, &ntb_transport_list);
 299         return 0;
 300 }
 301
 302 static void ntb_bus_remove(struct ntb_transport_ctx *nt)
 303 {
 304         struct ntb_transport_client_dev *client_dev, *cd;
 305
 306         list_for_each_entry_safe(client_dev, cd, &nt->client_devs, entry) {
 307                 dev_err(client_dev->dev.parent, "%s still attached to bus, removing\n",
 308                         dev_name(&client_dev->dev));
 309                 list_del(&client_dev->entry);
 310                 device_unregister(&client_dev->dev);
 311         }
 312
 313         list_del(&nt->entry);
 314 }
 315
 316 static void ntb_transport_client_release(struct device *dev)
 317 {
 318         struct ntb_transport_client_dev *client_dev;
 319
 320         client_dev = dev_client_dev(dev);
 321         kfree(client_dev);
 322 }
 323
 324 /**
 325  * ntb_transport_unregister_client_dev - Unregister NTB client device
 326  * @device_name: Name of NTB client device
 327  *
 328  * Unregister an NTB client device with the NTB transport layer
 329  */
 330 void ntb_transport_unregister_client_dev(char *device_name)
 331 {
 332         struct ntb_transport_client_dev *client, *cd;
 333         struct ntb_transport_ctx *nt;
 334
 335         list_for_each_entry(nt, &ntb_transport_list, entry)
 336                 list_for_each_entry_safe(client, cd, &nt->client_devs, entry)
 337                         if (!strncmp(dev_name(&client->dev), device_name,
 338                                      strlen(device_name))) {
 339                                 list_del(&client->entry);
 340                                 device_unregister(&client->dev);
 341                         }
 342 }
 343 EXPORT_SYMBOL_GPL(ntb_transport_unregister_client_dev);
 344
 345 /**
 346  * ntb_transport_register_client_dev - Register NTB client device
 347  * @device_name: Name of NTB client device
 348  *
 349  * Register an NTB client device with the NTB transport layer
 350  */
 351 int ntb_transport_register_client_dev(char *device_name)
 352 {
 353         struct ntb_transport_client_dev *client_dev;
 354         struct ntb_transport_ctx *nt;
 355         int node;
 356         int rc, i = 0;
 357
 358         if (list_empty(&ntb_transport_list))
 359                 return -ENODEV;
 360
 361         list_for_each_entry(nt, &ntb_transport_list, entry) {
 362                 struct device *dev;
 363
 364                 node = dev_to_node(&nt->ndev->dev);
 365
 366                 client_dev = kzalloc_node(sizeof(*client_dev),
 367                                           GFP_KERNEL, node);
 368                 if (!client_dev) {
 369                         rc = -ENOMEM;
 370                         goto err;
 371                 }
 372
 373                 dev = &client_dev->dev;
 374
 375                 /* setup and register client devices */
 376                 dev_set_name(dev, "%s%d", device_name, i);
 377                 dev->bus = &ntb_transport_bus;
 378                 dev->release = ntb_transport_client_release;
 379                 dev->parent = &nt->ndev->dev;
 380
 381                 rc = device_register(dev);
 382                 if (rc) {
 383                         kfree(client_dev);
 384                         goto err;
 385                 }
 386
 387                 list_add_tail(&client_dev->entry, &nt->client_devs);
 388                 i++;
 389         }
 390
 391         return 0;
 392
 393 err:
 394         ntb_transport_unregister_client_dev(device_name);
 395
 396         return rc;
 397 }
 398 EXPORT_SYMBOL_GPL(ntb_transport_register_client_dev);
 399
 400 /**
 401  * ntb_transport_register_client - Register NTB client driver
 402  * @drv: NTB client driver to be registered
 403  *
 404  * Register an NTB client driver with the NTB transport layer
 405  *
 406  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 407  */
 408 int ntb_transport_register_client(struct ntb_transport_client *drv)
 409 {
 410         drv->driver.bus = &ntb_transport_bus;
 411
 412         if (list_empty(&ntb_transport_list))
 413                 return -ENODEV;
 414
 415         return driver_register(&drv->driver);
 416 }
 417 EXPORT_SYMBOL_GPL(ntb_transport_register_client);
 418
 419 /**
 420  * ntb_transport_unregister_client - Unregister NTB client driver
 421  * @drv: NTB client driver to be unregistered
 422  *
 423  * Unregister an NTB client driver with the NTB transport layer
 424  *
 425  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 426  */
 427 void ntb_transport_unregister_client(struct ntb_transport_client *drv)
 428 {
 429         driver_unregister(&drv->driver);
 430 }
 431 EXPORT_SYMBOL_GPL(ntb_transport_unregister_client);
 432
 433 static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count,
 434                             loff_t *offp)
 435 {
 436         struct ntb_transport_qp *qp;
 437         char *buf;
 438         ssize_t ret, out_offset, out_count;
 439
 440         out_count = 1000;
 441
 442         buf = kmalloc(out_count, GFP_KERNEL);
 443         if (!buf)
 444                 return -ENOMEM;
 445
 446         qp = filp->private_data;
 447         out_offset = 0;
 448         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 449                                "NTB QP stats\n");
 450         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 451                                "rx_bytes - \t%llu\n", qp->rx_bytes);
 452         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 453                                "rx_pkts - \t%llu\n", qp->rx_pkts);
 454         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 455                                "rx_memcpy - \t%llu\n", qp->rx_memcpy);
 456         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 457                                "rx_async - \t%llu\n", qp->rx_async);
 458         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 459                                "rx_ring_empty - %llu\n", qp->rx_ring_empty);
 460         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 461                                "rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
 462         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 463                                "rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
 464         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 465                                "rx_err_ver - \t%llu\n", qp->rx_err_ver);
 466         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 467                                "rx_buff - \t%p\n", qp->rx_buff);
 468         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 469                                "rx_index - \t%u\n", qp->rx_index);
 470         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 471                                "rx_max_entry - \t%u\n", qp->rx_max_entry);
 472
 473         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 474                                "tx_bytes - \t%llu\n", qp->tx_bytes);
 475         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 476                                "tx_pkts - \t%llu\n", qp->tx_pkts);
 477         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 478                                "tx_memcpy - \t%llu\n", qp->tx_memcpy);
 479         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 480                                "tx_async - \t%llu\n", qp->tx_async);
 481         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 482                                "tx_ring_full - \t%llu\n", qp->tx_ring_full);
 483         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 484                                "tx_err_no_buf - %llu\n", qp->tx_err_no_buf);
 485         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 486                                "tx_mw - \t%p\n", qp->tx_mw);
 487         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 488                                "tx_index - \t%u\n", qp->tx_index);
 489         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 490                                "tx_max_entry - \t%u\n", qp->tx_max_entry);
 491
 492         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 493                                "\nQP Link %s\n",
 494                                qp->link_is_up ? "Up" : "Down");
 495         if (out_offset > out_count)
 496                 out_offset = out_count;
 497
 498         ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
 499         kfree(buf);
 500         return ret;
 501 }
 502
 503 static const struct file_operations ntb_qp_debugfs_stats = {
 504         .owner = THIS_MODULE,
 505         .open = simple_open,
 506         .read = debugfs_read,
 507 };
 508
 509 static void ntb_list_add(spinlock_t *lock, struct list_head *entry,
 510                          struct list_head *list)
 511 {
 512         unsigned long flags;
 513
 514         spin_lock_irqsave(lock, flags);
 515         list_add_tail(entry, list);
 516         spin_unlock_irqrestore(lock, flags);
 517 }
 518
 519 static struct ntb_queue_entry *ntb_list_rm(spinlock_t *lock,
 520                                            struct list_head *list)
 521 {
 522         struct ntb_queue_entry *entry;
 523         unsigned long flags;
 524
 525         spin_lock_irqsave(lock, flags);
 526         if (list_empty(list)) {
 527                 entry = NULL;
 528                 goto out;
 529         }
 530         entry = list_first_entry(list, struct ntb_queue_entry, entry);
 531         list_del(&entry->entry);
 532 out:
 533         spin_unlock_irqrestore(lock, flags);
 534
 535         return entry;
 536 }
 537
 538 static struct ntb_queue_entry *ntb_list_mv(spinlock_t *lock,
 539                                            struct list_head *list,
 540                                            struct list_head *to_list)
 541 {
 542         struct ntb_queue_entry *entry;
 543         unsigned long flags;
 544
 545         spin_lock_irqsave(lock, flags);
 546
 547         if (list_empty(list)) {
 548                 entry = NULL;
 549         } else {
 550                 entry = list_first_entry(list, struct ntb_queue_entry, entry);
 551                 list_move_tail(&entry->entry, to_list);
 552         }
 553
 554         spin_unlock_irqrestore(lock, flags);
 555
 556         return entry;
 557 }
 558
 559 static int ntb_transport_setup_qp_mw(struct ntb_transport_ctx *nt,
 560                                      unsigned int qp_num)
 561 {
 562         struct ntb_transport_qp *qp = &nt->qp_vec[qp_num];
 563         struct ntb_transport_mw *mw;
 564         unsigned int rx_size, num_qps_mw;
 565         unsigned int mw_num, mw_count, qp_count;
 566         unsigned int i;
 567
 568         mw_count = nt->mw_count;
 569         qp_count = nt->qp_count;
 570
 571         mw_num = QP_TO_MW(nt, qp_num);
 572         mw = &nt->mw_vec[mw_num];
 573
 574         if (!mw->virt_addr)
 575                 return -ENOMEM;
 576
 577         if (qp_count % mw_count && mw_num + 1 < qp_count / mw_count)
 578                 num_qps_mw = qp_count / mw_count + 1;
 579         else
 580                 num_qps_mw = qp_count / mw_count;
 581
 582         rx_size = (unsigned int)mw->xlat_size / num_qps_mw;
 583         qp->rx_buff = mw->virt_addr + rx_size * qp_num / mw_count;
 584         rx_size -= sizeof(struct ntb_rx_info);
 585
 586         qp->remote_rx_info = qp->rx_buff + rx_size;
 587
 588         /* Due to housekeeping, there must be atleast 2 buffs */
 589         qp->rx_max_frame = min(transport_mtu, rx_size / 2);
 590         qp->rx_max_entry = rx_size / qp->rx_max_frame;
 591         qp->rx_index = 0;
 592
 593         qp->remote_rx_info->entry = qp->rx_max_entry - 1;
 594
 595         /* setup the hdr offsets with 0's */
 596         for (i = 0; i < qp->rx_max_entry; i++) {
 597                 void *offset = (qp->rx_buff + qp->rx_max_frame * (i + 1) -
 598                                 sizeof(struct ntb_payload_header));
 599                 memset(offset, 0, sizeof(struct ntb_payload_header));
 600         }
 601
 602         qp->rx_pkts = 0;
 603         qp->tx_pkts = 0;
 604         qp->tx_index = 0;
 605
 606         return 0;
 607 }
 608
 609 static void ntb_free_mw(struct ntb_transport_ctx *nt, int num_mw)
 610 {
 611         struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
 612         struct pci_dev *pdev = nt->ndev->pdev;
 613
 614         if (!mw->virt_addr)
 615                 return;
 616
 617         ntb_mw_clear_trans(nt->ndev, num_mw);
 618         dma_free_coherent(&pdev->dev, mw->buff_size,
 619                           mw->virt_addr, mw->dma_addr);
 620         mw->xlat_size = 0;
 621         mw->buff_size = 0;
 622         mw->virt_addr = NULL;
 623 }
 624
 625 static int ntb_set_mw(struct ntb_transport_ctx *nt, int num_mw,
 626                       unsigned int size)
 627 {
 628         struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
 629         struct pci_dev *pdev = nt->ndev->pdev;
 630         unsigned int xlat_size, buff_size;
 631         int rc;
 632
 633         xlat_size = round_up(size, mw->xlat_align_size);
 634         buff_size = round_up(size, mw->xlat_align);
 635
 636         /* No need to re-setup */
 637         if (mw->xlat_size == xlat_size)
 638                 return 0;
 639
 640         if (mw->buff_size)
 641                 ntb_free_mw(nt, num_mw);
 642
 643         /* Alloc memory for receiving data.  Must be aligned */
 644         mw->xlat_size = xlat_size;
 645         mw->buff_size = buff_size;
 646
 647         mw->virt_addr = dma_alloc_coherent(&pdev->dev, buff_size,
 648                                            &mw->dma_addr, GFP_KERNEL);
 649         if (!mw->virt_addr) {
 650                 mw->xlat_size = 0;
 651                 mw->buff_size = 0;
 652                 dev_err(&pdev->dev, "Unable to alloc MW buff of size %d\n",
 653                         buff_size);
 654                 return -ENOMEM;
 655         }
 656
 657         /*
 658          * we must ensure that the memory address allocated is BAR size
 659          * aligned in order for the XLAT register to take the value. This
 660          * is a requirement of the hardware. It is recommended to setup CMA
 661          * for BAR sizes equal or greater than 4MB.
 662          */
 663         if (!IS_ALIGNED(mw->dma_addr, mw->xlat_align)) {
 664                 dev_err(&pdev->dev, "DMA memory %pad is not aligned\n",
 665                         &mw->dma_addr);
 666                 ntb_free_mw(nt, num_mw);
 667                 return -ENOMEM;
 668         }
 669
 670         /* Notify HW the memory location of the receive buffer */
 671         rc = ntb_mw_set_trans(nt->ndev, num_mw, mw->dma_addr, mw->xlat_size);
 672         if (rc) {
 673                 dev_err(&pdev->dev, "Unable to set mw%d translation", num_mw);
 674                 ntb_free_mw(nt, num_mw);
 675                 return -EIO;
 676         }
 677
 678         return 0;
 679 }
 680
 681 static void ntb_qp_link_down_reset(struct ntb_transport_qp *qp)
 682 {
 683         qp->link_is_up = false;
 684
 685         qp->tx_index = 0;
 686         qp->rx_index = 0;
 687         qp->rx_bytes = 0;
 688         qp->rx_pkts = 0;
 689         qp->rx_ring_empty = 0;
 690         qp->rx_err_no_buf = 0;
 691         qp->rx_err_oflow = 0;
 692         qp->rx_err_ver = 0;
 693         qp->rx_memcpy = 0;
 694         qp->rx_async = 0;
 695         qp->tx_bytes = 0;
 696         qp->tx_pkts = 0;
 697         qp->tx_ring_full = 0;
 698         qp->tx_err_no_buf = 0;
 699         qp->tx_memcpy = 0;
 700         qp->tx_async = 0;
 701 }
 702
 703 static void ntb_qp_link_cleanup(struct ntb_transport_qp *qp)
 704 {
 705         struct ntb_transport_ctx *nt = qp->transport;
 706         struct pci_dev *pdev = nt->ndev->pdev;
 707
 708         dev_info(&pdev->dev, "qp %d: Link Cleanup\n", qp->qp_num);
 709
 710         cancel_delayed_work_sync(&qp->link_work);
 711         ntb_qp_link_down_reset(qp);
 712
 713         if (qp->event_handler)
 714                 qp->event_handler(qp->cb_data, qp->link_is_up);
 715 }
 716
 717 static void ntb_qp_link_cleanup_work(struct work_struct *work)
 718 {
 719         struct ntb_transport_qp *qp = container_of(work,
 720                                                    struct ntb_transport_qp,
 721                                                    link_cleanup);
 722         struct ntb_transport_ctx *nt = qp->transport;
 723
 724         ntb_qp_link_cleanup(qp);
 725
 726         if (nt->link_is_up)
 727                 schedule_delayed_work(&qp->link_work,
 728                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 729 }
 730
 731 static void ntb_qp_link_down(struct ntb_transport_qp *qp)
 732 {
 733         schedule_work(&qp->link_cleanup);
 734 }
 735
 736 static void ntb_transport_link_cleanup(struct ntb_transport_ctx *nt)
 737 {
 738         struct ntb_transport_qp *qp;
 739         u64 qp_bitmap_alloc;
 740         int i;
 741
 742         qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
 743
 744         /* Pass along the info to any clients */
 745         for (i = 0; i < nt->qp_count; i++)
 746                 if (qp_bitmap_alloc & BIT_ULL(i)) {
 747                         qp = &nt->qp_vec[i];
 748                         ntb_qp_link_cleanup(qp);
 749                         cancel_work_sync(&qp->link_cleanup);
 750                         cancel_delayed_work_sync(&qp->link_work);
 751                 }
 752
 753         if (!nt->link_is_up)
 754                 cancel_delayed_work_sync(&nt->link_work);
 755
 756         /* The scratchpad registers keep the values if the remote side
 757          * goes down, blast them now to give them a sane value the next
 758          * time they are accessed
 759          */
 760         for (i = 0; i < MAX_SPAD; i++)
 761                 ntb_spad_write(nt->ndev, i, 0);
 762 }
 763
 764 static void ntb_transport_link_cleanup_work(struct work_struct *work)
 765 {
 766         struct ntb_transport_ctx *nt =
 767                 container_of(work, struct ntb_transport_ctx, link_cleanup);
 768
 769         ntb_transport_link_cleanup(nt);
 770 }
 771
 772 static void ntb_transport_event_callback(void *data)
 773 {
 774         struct ntb_transport_ctx *nt = data;
 775
 776         if (ntb_link_is_up(nt->ndev, NULL, NULL) == 1)
 777                 schedule_delayed_work(&nt->link_work, 0);
 778         else
 779                 schedule_work(&nt->link_cleanup);
 780 }
 781
 782 static void ntb_transport_link_work(struct work_struct *work)
 783 {
 784         struct ntb_transport_ctx *nt =
 785                 container_of(work, struct ntb_transport_ctx, link_work.work);
 786         struct ntb_dev *ndev = nt->ndev;
 787         struct pci_dev *pdev = ndev->pdev;
 788         resource_size_t size;
 789         u32 val;
 790         int rc, i, spad;
 791
 792         /* send the local info, in the opposite order of the way we read it */
 793         for (i = 0; i < nt->mw_count; i++) {
 794                 size = nt->mw_vec[i].phys_size;
 795
 796                 if (max_mw_size && size > max_mw_size)
 797                         size = max_mw_size;
 798
 799                 spad = MW0_SZ_HIGH + (i * 2);
 800                 ntb_peer_spad_write(ndev, spad, (u32)(size >> 32));
 801
 802                 spad = MW0_SZ_LOW + (i * 2);
 803                 ntb_peer_spad_write(ndev, spad, (u32)size);
 804         }
 805
 806         ntb_peer_spad_write(ndev, NUM_MWS, nt->mw_count);
 807
 808         ntb_peer_spad_write(ndev, NUM_QPS, nt->qp_count);
 809
 810         ntb_peer_spad_write(ndev, VERSION, NTB_TRANSPORT_VERSION);
 811
 812         /* Query the remote side for its info */
 813         val = ntb_spad_read(ndev, VERSION);
 814         dev_dbg(&pdev->dev, "Remote version = %d\n", val);
 815         if (val != NTB_TRANSPORT_VERSION)
 816                 goto out;
 817
 818         val = ntb_spad_read(ndev, NUM_QPS);
 819         dev_dbg(&pdev->dev, "Remote max number of qps = %d\n", val);
 820         if (val != nt->qp_count)
 821                 goto out;
 822
 823         val = ntb_spad_read(ndev, NUM_MWS);
 824         dev_dbg(&pdev->dev, "Remote number of mws = %d\n", val);
 825         if (val != nt->mw_count)
 826                 goto out;
 827
 828         for (i = 0; i < nt->mw_count; i++) {
 829                 u64 val64;
 830
 831                 val = ntb_spad_read(ndev, MW0_SZ_HIGH + (i * 2));
 832                 val64 = (u64)val << 32;
 833
 834                 val = ntb_spad_read(ndev, MW0_SZ_LOW + (i * 2));
 835                 val64 |= val;
 836
 837                 dev_dbg(&pdev->dev, "Remote MW%d size = %#llx\n", i, val64);
 838
 839                 rc = ntb_set_mw(nt, i, val64);
 840                 if (rc)
 841                         goto out1;
 842         }
 843
 844         nt->link_is_up = true;
 845
 846         for (i = 0; i < nt->qp_count; i++) {
 847                 struct ntb_transport_qp *qp = &nt->qp_vec[i];
 848
 849                 ntb_transport_setup_qp_mw(nt, i);
 850
 851                 if (qp->client_ready)
 852                         schedule_delayed_work(&qp->link_work, 0);
 853         }
 854
 855         return;
 856
 857 out1:
 858         for (i = 0; i < nt->mw_count; i++)
 859                 ntb_free_mw(nt, i);
 860 out:
 861         if (ntb_link_is_up(ndev, NULL, NULL) == 1)
 862                 schedule_delayed_work(&nt->link_work,
 863                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 864 }
 865
 866 static void ntb_qp_link_work(struct work_struct *work)
 867 {
 868         struct ntb_transport_qp *qp = container_of(work,
 869                                                    struct ntb_transport_qp,
 870                                                    link_work.work);
 871         struct pci_dev *pdev = qp->ndev->pdev;
 872         struct ntb_transport_ctx *nt = qp->transport;
 873         int val;
 874
 875         WARN_ON(!nt->link_is_up);
 876
 877         val = ntb_spad_read(nt->ndev, QP_LINKS);
 878
 879         ntb_peer_spad_write(nt->ndev, QP_LINKS, val | BIT(qp->qp_num));
 880
 881         /* query remote spad for qp ready bits */
 882         ntb_peer_spad_read(nt->ndev, QP_LINKS);
 883         dev_dbg_ratelimited(&pdev->dev, "Remote QP link status = %x\n", val);
 884
 885         /* See if the remote side is up */
 886         if (val & BIT(qp->qp_num)) {
 887                 dev_info(&pdev->dev, "qp %d: Link Up\n", qp->qp_num);
 888                 qp->link_is_up = true;
 889
 890                 if (qp->event_handler)
 891                         qp->event_handler(qp->cb_data, qp->link_is_up);
 892         } else if (nt->link_is_up)
 893                 schedule_delayed_work(&qp->link_work,
 894                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 895 }
 896
 897 static int ntb_transport_init_queue(struct ntb_transport_ctx *nt,
 898                                     unsigned int qp_num)
 899 {
 900         struct ntb_transport_qp *qp;
 901         struct ntb_transport_mw *mw;
 902         phys_addr_t mw_base;
 903         resource_size_t mw_size;
 904         unsigned int num_qps_mw, tx_size;
 905         unsigned int mw_num, mw_count, qp_count;
 906         u64 qp_offset;
 907
 908         mw_count = nt->mw_count;
 909         qp_count = nt->qp_count;
 910
 911         mw_num = QP_TO_MW(nt, qp_num);
 912         mw = &nt->mw_vec[mw_num];
 913
 914         qp = &nt->qp_vec[qp_num];
 915         qp->qp_num = qp_num;
 916         qp->transport = nt;
 917         qp->ndev = nt->ndev;
 918         qp->client_ready = false;
 919         qp->event_handler = NULL;
 920         ntb_qp_link_down_reset(qp);
 921
 922         if (qp_count % mw_count && mw_num + 1 < qp_count / mw_count)
 923                 num_qps_mw = qp_count / mw_count + 1;
 924         else
 925                 num_qps_mw = qp_count / mw_count;
 926
 927         mw_base = nt->mw_vec[mw_num].phys_addr;
 928         mw_size = nt->mw_vec[mw_num].phys_size;
 929
 930         tx_size = (unsigned int)mw_size / num_qps_mw;
 931         qp_offset = tx_size * qp_num / mw_count;
 932
 933         qp->tx_mw = nt->mw_vec[mw_num].vbase + qp_offset;
 934         if (!qp->tx_mw)
 935                 return -EINVAL;
 936
 937         qp->tx_mw_phys = mw_base + qp_offset;
 938         if (!qp->tx_mw_phys)
 939                 return -EINVAL;
 940
 941         tx_size -= sizeof(struct ntb_rx_info);
 942         qp->rx_info = qp->tx_mw + tx_size;
 943
 944         /* Due to housekeeping, there must be atleast 2 buffs */
 945         qp->tx_max_frame = min(transport_mtu, tx_size / 2);
 946         qp->tx_max_entry = tx_size / qp->tx_max_frame;
 947
 948         if (nt_debugfs_dir) {
 949                 char debugfs_name[4];
 950
 951                 snprintf(debugfs_name, 4, "qp%d", qp_num);
 952                 qp->debugfs_dir = debugfs_create_dir(debugfs_name,
 953                                                      nt_debugfs_dir);
 954
 955                 qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR,
 956                                                         qp->debugfs_dir, qp,
 957                                                         &ntb_qp_debugfs_stats);
 958         } else {
 959                 qp->debugfs_dir = NULL;
 960                 qp->debugfs_stats = NULL;
 961         }
 962
 963         INIT_DELAYED_WORK(&qp->link_work, ntb_qp_link_work);
 964         INIT_WORK(&qp->link_cleanup, ntb_qp_link_cleanup_work);
 965
 966         spin_lock_init(&qp->ntb_rx_q_lock);
 967         spin_lock_init(&qp->ntb_tx_free_q_lock);
 968
 969         INIT_LIST_HEAD(&qp->rx_post_q);
 970         INIT_LIST_HEAD(&qp->rx_pend_q);
 971         INIT_LIST_HEAD(&qp->rx_free_q);
 972         INIT_LIST_HEAD(&qp->tx_free_q);
 973
 974         tasklet_init(&qp->rxc_db_work, ntb_transport_rxc_db,
 975                      (unsigned long)qp);
 976
 977         return 0;
 978 }
 979
 980 static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev)
 981 {
 982         struct ntb_transport_ctx *nt;
 983         struct ntb_transport_mw *mw;
 984         unsigned int mw_count, qp_count;
 985         u64 qp_bitmap;
 986         int node;
 987         int rc, i;
 988
 989         if (ntb_db_is_unsafe(ndev))
 990                 dev_dbg(&ndev->dev,
 991                         "doorbell is unsafe, proceed anyway...\n");
 992         if (ntb_spad_is_unsafe(ndev))
 993                 dev_dbg(&ndev->dev,
 994                         "scratchpad is unsafe, proceed anyway...\n");
 995
 996         node = dev_to_node(&ndev->dev);
 997
 998         nt = kzalloc_node(sizeof(*nt), GFP_KERNEL, node);
 999         if (!nt)
1000                 return -ENOMEM;
1001
1002         nt->ndev = ndev;
1003
1004         mw_count = ntb_mw_count(ndev);
1005
1006         nt->mw_count = mw_count;
1007
1008         nt->mw_vec = kzalloc_node(mw_count * sizeof(*nt->mw_vec),
1009                                   GFP_KERNEL, node);
1010         if (!nt->mw_vec) {
1011                 rc = -ENOMEM;
1012                 goto err;
1013         }
1014
1015         for (i = 0; i < mw_count; i++) {
1016                 mw = &nt->mw_vec[i];
1017
1018                 rc = ntb_mw_get_range(ndev, i, &mw->phys_addr, &mw->phys_size,
1019                                       &mw->xlat_align, &mw->xlat_align_size);
1020                 if (rc)
1021                         goto err1;
1022
1023                 mw->vbase = ioremap_wc(mw->phys_addr, mw->phys_size);
1024                 if (!mw->vbase) {
1025                         rc = -ENOMEM;
1026                         goto err1;
1027                 }
1028
1029                 mw->buff_size = 0;
1030                 mw->xlat_size = 0;
1031                 mw->virt_addr = NULL;
1032                 mw->dma_addr = 0;
1033         }
1034
1035         qp_bitmap = ntb_db_valid_mask(ndev);
1036
1037         qp_count = ilog2(qp_bitmap);
1038         if (max_num_clients && max_num_clients < qp_count)
1039                 qp_count = max_num_clients;
1040         else if (mw_count < qp_count)
1041                 qp_count = mw_count;
1042
1043         qp_bitmap &= BIT_ULL(qp_count) - 1;
1044
1045         nt->qp_count = qp_count;
1046         nt->qp_bitmap = qp_bitmap;
1047         nt->qp_bitmap_free = qp_bitmap;
1048
1049         nt->qp_vec = kzalloc_node(qp_count * sizeof(*nt->qp_vec),
1050                                   GFP_KERNEL, node);
1051         if (!nt->qp_vec) {
1052                 rc = -ENOMEM;
1053                 goto err2;
1054         }
1055
1056         for (i = 0; i < qp_count; i++) {
1057                 rc = ntb_transport_init_queue(nt, i);
1058                 if (rc)
1059                         goto err3;
1060         }
1061
1062         INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work);
1063         INIT_WORK(&nt->link_cleanup, ntb_transport_link_cleanup_work);
1064
1065         rc = ntb_set_ctx(ndev, nt, &ntb_transport_ops);
1066         if (rc)
1067                 goto err3;
1068
1069         INIT_LIST_HEAD(&nt->client_devs);
1070         rc = ntb_bus_init(nt);
1071         if (rc)
1072                 goto err4;
1073
1074         nt->link_is_up = false;
1075         ntb_link_enable(ndev, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
1076         ntb_link_event(ndev);
1077
1078         return 0;
1079
1080 err4:
1081         ntb_clear_ctx(ndev);
1082 err3:
1083         kfree(nt->qp_vec);
1084 err2:
1085         kfree(nt->mw_vec);
1086 err1:
1087         while (i--) {
1088                 mw = &nt->mw_vec[i];
1089                 iounmap(mw->vbase);
1090         }
1091 err:
1092         kfree(nt);
1093         return rc;
1094 }
1095
1096 static void ntb_transport_free(struct ntb_client *self, struct ntb_dev *ndev)
1097 {
1098         struct ntb_transport_ctx *nt = ndev->ctx;
1099         struct ntb_transport_qp *qp;
1100         u64 qp_bitmap_alloc;
1101         int i;
1102
1103         ntb_transport_link_cleanup(nt);
1104         cancel_work_sync(&nt->link_cleanup);
1105         cancel_delayed_work_sync(&nt->link_work);
1106
1107         qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
1108
1109         /* verify that all the qp's are freed */
1110         for (i = 0; i < nt->qp_count; i++) {
1111                 qp = &nt->qp_vec[i];
1112                 if (qp_bitmap_alloc & BIT_ULL(i))
1113                         ntb_transport_free_queue(qp);
1114                 debugfs_remove_recursive(qp->debugfs_dir);
1115         }
1116
1117         ntb_link_disable(ndev);
1118         ntb_clear_ctx(ndev);
1119
1120         ntb_bus_remove(nt);
1121
1122         for (i = nt->mw_count; i--; ) {
1123                 ntb_free_mw(nt, i);
1124                 iounmap(nt->mw_vec[i].vbase);
1125         }
1126
1127         kfree(nt->qp_vec);
1128         kfree(nt->mw_vec);
1129         kfree(nt);
1130 }
1131
1132 static void ntb_complete_rxc(struct ntb_transport_qp *qp)
1133 {
1134         struct ntb_queue_entry *entry;
1135         void *cb_data;
1136         unsigned int len;
1137         unsigned long irqflags;
1138
1139         spin_lock_irqsave(&qp->ntb_rx_q_lock, irqflags);
1140
1141         while (!list_empty(&qp->rx_post_q)) {
1142                 entry = list_first_entry(&qp->rx_post_q,
1143                                          struct ntb_queue_entry, entry);
1144                 if (!(entry->flags & DESC_DONE_FLAG))
1145                         break;
1146
1147                 entry->rx_hdr->flags = 0;
1148                 iowrite32(entry->index, &qp->rx_info->entry);
1149
1150                 cb_data = entry->cb_data;
1151                 len = entry->len;
1152
1153                 list_move_tail(&entry->entry, &qp->rx_free_q);
1154
1155                 spin_unlock_irqrestore(&qp->ntb_rx_q_lock, irqflags);
1156
1157                 if (qp->rx_handler && qp->client_ready)
1158                         qp->rx_handler(qp, qp->cb_data, cb_data, len);
1159
1160                 spin_lock_irqsave(&qp->ntb_rx_q_lock, irqflags);
1161         }
1162
1163         spin_unlock_irqrestore(&qp->ntb_rx_q_lock, irqflags);
1164 }
1165
1166 static void ntb_rx_copy_callback(void *data)
1167 {
1168         struct ntb_queue_entry *entry = data;
1169
1170         entry->flags |= DESC_DONE_FLAG;
1171
1172         ntb_complete_rxc(entry->qp);
1173 }
1174
1175 static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void *offset)
1176 {
1177         void *buf = entry->buf;
1178         size_t len = entry->len;
1179
1180         memcpy(buf, offset, len);
1181
1182         /* Ensure that the data is fully copied out before clearing the flag */
1183         wmb();
1184
1185         ntb_rx_copy_callback(entry);
1186 }
1187
1188 static void ntb_async_rx(struct ntb_queue_entry *entry, void *offset)
1189 {
1190         struct dma_async_tx_descriptor *txd;
1191         struct ntb_transport_qp *qp = entry->qp;
1192         struct dma_chan *chan = qp->dma_chan;
1193         struct dma_device *device;
1194         size_t pay_off, buff_off, len;
1195         struct dmaengine_unmap_data *unmap;
1196         dma_cookie_t cookie;
1197         void *buf = entry->buf;
1198
1199         len = entry->len;
1200
1201         if (!chan)
1202                 goto err;
1203
1204         if (len < copy_bytes)
1205                 goto err_wait;
1206
1207         device = chan->device;
1208         pay_off = (size_t)offset & ~PAGE_MASK;
1209         buff_off = (size_t)buf & ~PAGE_MASK;
1210
1211         if (!is_dma_copy_aligned(device, pay_off, buff_off, len))
1212                 goto err_wait;
1213
1214         unmap = dmaengine_get_unmap_data(device->dev, 2, GFP_NOWAIT);
1215         if (!unmap)
1216                 goto err_wait;
1217
1218         unmap->len = len;
1219         unmap->addr[0] = dma_map_page(device->dev, virt_to_page(offset),
1220                                       pay_off, len, DMA_TO_DEVICE);
1221         if (dma_mapping_error(device->dev, unmap->addr[0]))
1222                 goto err_get_unmap;
1223
1224         unmap->to_cnt = 1;
1225
1226         unmap->addr[1] = dma_map_page(device->dev, virt_to_page(buf),
1227                                       buff_off, len, DMA_FROM_DEVICE);
1228         if (dma_mapping_error(device->dev, unmap->addr[1]))
1229                 goto err_get_unmap;
1230
1231         unmap->from_cnt = 1;
1232
1233         txd = device->device_prep_dma_memcpy(chan, unmap->addr[1],
1234                                              unmap->addr[0], len,
1235                                              DMA_PREP_INTERRUPT);
1236         if (!txd)
1237                 goto err_get_unmap;
1238
1239         txd->callback = ntb_rx_copy_callback;
1240         txd->callback_param = entry;
1241         dma_set_unmap(txd, unmap);
1242
1243         cookie = dmaengine_submit(txd);
1244         if (dma_submit_error(cookie))
1245                 goto err_set_unmap;
1246
1247         dmaengine_unmap_put(unmap);
1248
1249         qp->last_cookie = cookie;
1250
1251         qp->rx_async++;
1252
1253         return;
1254
1255 err_set_unmap:
1256         dmaengine_unmap_put(unmap);
1257 err_get_unmap:
1258         dmaengine_unmap_put(unmap);
1259 err_wait:
1260         /* If the callbacks come out of order, the writing of the index to the
1261          * last completed will be out of order.  This may result in the
1262          * receive stalling forever.
1263          */
1264         dma_sync_wait(chan, qp->last_cookie);
1265 err:
1266         ntb_memcpy_rx(entry, offset);
1267         qp->rx_memcpy++;
1268 }
1269
1270 static int ntb_process_rxc(struct ntb_transport_qp *qp)
1271 {
1272         struct ntb_payload_header *hdr;
1273         struct ntb_queue_entry *entry;
1274         void *offset;
1275
1276         offset = qp->rx_buff + qp->rx_max_frame * qp->rx_index;
1277         hdr = offset + qp->rx_max_frame - sizeof(struct ntb_payload_header);
1278
1279         dev_dbg(&qp->ndev->pdev->dev, "qp %d: RX ver %u len %d flags %x\n",
1280                 qp->qp_num, hdr->ver, hdr->len, hdr->flags);
1281
1282         if (!(hdr->flags & DESC_DONE_FLAG)) {
1283                 dev_dbg(&qp->ndev->pdev->dev, "done flag not set\n");
1284                 qp->rx_ring_empty++;
1285                 return -EAGAIN;
1286         }
1287
1288         if (hdr->flags & LINK_DOWN_FLAG) {
1289                 dev_dbg(&qp->ndev->pdev->dev, "link down flag set\n");
1290                 ntb_qp_link_down(qp);
1291                 hdr->flags = 0;
1292                 return -EAGAIN;
1293         }
1294
1295         if (hdr->ver != (u32)qp->rx_pkts) {
1296                 dev_dbg(&qp->ndev->pdev->dev,
1297                         "version mismatch, expected %llu - got %u\n",
1298                         qp->rx_pkts, hdr->ver);
1299                 qp->rx_err_ver++;
1300                 return -EIO;
1301         }
1302
1303         entry = ntb_list_mv(&qp->ntb_rx_q_lock, &qp->rx_pend_q, &qp->rx_post_q);
1304         if (!entry) {
1305                 dev_dbg(&qp->ndev->pdev->dev, "no receive buffer\n");
1306                 qp->rx_err_no_buf++;
1307                 return -EAGAIN;
1308         }
1309
1310         entry->rx_hdr = hdr;
1311         entry->index = qp->rx_index;
1312
1313         if (hdr->len > entry->len) {
1314                 dev_dbg(&qp->ndev->pdev->dev,
1315                         "receive buffer overflow! Wanted %d got %d\n",
1316                         hdr->len, entry->len);
1317                 qp->rx_err_oflow++;
1318
1319                 entry->len = -EIO;
1320                 entry->flags |= DESC_DONE_FLAG;
1321
1322                 ntb_complete_rxc(qp);
1323         } else {
1324                 dev_dbg(&qp->ndev->pdev->dev,
1325                         "RX OK index %u ver %u size %d into buf size %d\n",
1326                         qp->rx_index, hdr->ver, hdr->len, entry->len);
1327
1328                 qp->rx_bytes += hdr->len;
1329                 qp->rx_pkts++;
1330
1331                 entry->len = hdr->len;
1332
1333                 ntb_async_rx(entry, offset);
1334         }
1335
1336         qp->rx_index++;
1337         qp->rx_index %= qp->rx_max_entry;
1338
1339         return 0;
1340 }
1341
1342 static void ntb_transport_rxc_db(unsigned long data)
1343 {
1344         struct ntb_transport_qp *qp = (void *)data;
1345         int rc, i;
1346
1347         dev_dbg(&qp->ndev->pdev->dev, "%s: doorbell %d received\n",
1348                 __func__, qp->qp_num);
1349
1350         /* Limit the number of packets processed in a single interrupt to
1351          * provide fairness to others
1352          */
1353         for (i = 0; i < qp->rx_max_entry; i++) {
1354                 rc = ntb_process_rxc(qp);
1355                 if (rc)
1356                         break;
1357         }
1358
1359         if (i && qp->dma_chan)
1360                 dma_async_issue_pending(qp->dma_chan);
1361
1362         if (i == qp->rx_max_entry) {
1363                 /* there is more work to do */
1364                 tasklet_schedule(&qp->rxc_db_work);
1365         } else if (ntb_db_read(qp->ndev) & BIT_ULL(qp->qp_num)) {
1366                 /* the doorbell bit is set: clear it */
1367                 ntb_db_clear(qp->ndev, BIT_ULL(qp->qp_num));
1368                 /* ntb_db_read ensures ntb_db_clear write is committed */
1369                 ntb_db_read(qp->ndev);
1370
1371                 /* an interrupt may have arrived between finishing
1372                  * ntb_process_rxc and clearing the doorbell bit:
1373                  * there might be some more work to do.
1374                  */
1375                 tasklet_schedule(&qp->rxc_db_work);
1376         }
1377 }
1378
1379 static void ntb_tx_copy_callback(void *data)
1380 {
1381         struct ntb_queue_entry *entry = data;
1382         struct ntb_transport_qp *qp = entry->qp;
1383         struct ntb_payload_header __iomem *hdr = entry->tx_hdr;
1384
1385         iowrite32(entry->flags | DESC_DONE_FLAG, &hdr->flags);
1386
1387         ntb_peer_db_set(qp->ndev, BIT_ULL(qp->qp_num));
1388
1389         /* The entry length can only be zero if the packet is intended to be a
1390          * "link down" or similar.  Since no payload is being sent in these
1391          * cases, there is nothing to add to the completion queue.
1392          */
1393         if (entry->len > 0) {
1394                 qp->tx_bytes += entry->len;
1395
1396                 if (qp->tx_handler)
1397                         qp->tx_handler(qp, qp->cb_data, entry->cb_data,
1398                                        entry->len);
1399         }
1400
1401         ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q);
1402 }
1403
1404 static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset)
1405 {
1406 #ifdef ARCH_HAS_NOCACHE_UACCESS
1407         /*
1408          * Using non-temporal mov to improve performance on non-cached
1409          * writes, even though we aren't actually copying from user space.
1410          */
1411         __copy_from_user_inatomic_nocache(offset, entry->buf, entry->len);
1412 #else
1413         memcpy_toio(offset, entry->buf, entry->len);
1414 #endif
1415
1416         /* Ensure that the data is fully copied out before setting the flags */
1417         wmb();
1418
1419         ntb_tx_copy_callback(entry);
1420 }
1421
1422 static void ntb_async_tx(struct ntb_transport_qp *qp,
1423                          struct ntb_queue_entry *entry)
1424 {
1425         struct ntb_payload_header __iomem *hdr;
1426         struct dma_async_tx_descriptor *txd;
1427         struct dma_chan *chan = qp->dma_chan;
1428         struct dma_device *device;
1429         size_t dest_off, buff_off;
1430         struct dmaengine_unmap_data *unmap;
1431         dma_addr_t dest;
1432         dma_cookie_t cookie;
1433         void __iomem *offset;
1434         size_t len = entry->len;
1435         void *buf = entry->buf;
1436
1437         offset = qp->tx_mw + qp->tx_max_frame * qp->tx_index;
1438         hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
1439         entry->tx_hdr = hdr;
1440
1441         iowrite32(entry->len, &hdr->len);
1442         iowrite32((u32)qp->tx_pkts, &hdr->ver);
1443
1444         if (!chan)
1445                 goto err;
1446
1447         if (len < copy_bytes)
1448                 goto err;
1449
1450         device = chan->device;
1451         dest = qp->tx_mw_phys + qp->tx_max_frame * qp->tx_index;
1452         buff_off = (size_t)buf & ~PAGE_MASK;
1453         dest_off = (size_t)dest & ~PAGE_MASK;
1454
1455         if (!is_dma_copy_aligned(device, buff_off, dest_off, len))
1456                 goto err;
1457
1458         unmap = dmaengine_get_unmap_data(device->dev, 1, GFP_NOWAIT);
1459         if (!unmap)
1460                 goto err;
1461
1462         unmap->len = len;
1463         unmap->addr[0] = dma_map_page(device->dev, virt_to_page(buf),
1464                                       buff_off, len, DMA_TO_DEVICE);
1465         if (dma_mapping_error(device->dev, unmap->addr[0]))
1466                 goto err_get_unmap;
1467
1468         unmap->to_cnt = 1;
1469
1470         txd = device->device_prep_dma_memcpy(chan, dest, unmap->addr[0], len,
1471                                              DMA_PREP_INTERRUPT);
1472         if (!txd)
1473                 goto err_get_unmap;
1474
1475         txd->callback = ntb_tx_copy_callback;
1476         txd->callback_param = entry;
1477         dma_set_unmap(txd, unmap);
1478
1479         cookie = dmaengine_submit(txd);
1480         if (dma_submit_error(cookie))
1481                 goto err_set_unmap;
1482
1483         dmaengine_unmap_put(unmap);
1484
1485         dma_async_issue_pending(chan);
1486         qp->tx_async++;
1487
1488         return;
1489 err_set_unmap:
1490         dmaengine_unmap_put(unmap);
1491 err_get_unmap:
1492         dmaengine_unmap_put(unmap);
1493 err:
1494         ntb_memcpy_tx(entry, offset);
1495         qp->tx_memcpy++;
1496 }
1497
1498 static int ntb_process_tx(struct ntb_transport_qp *qp,
1499                           struct ntb_queue_entry *entry)
1500 {
1501         if (qp->tx_index == qp->remote_rx_info->entry) {
1502                 qp->tx_ring_full++;
1503                 return -EAGAIN;
1504         }
1505
1506         if (entry->len > qp->tx_max_frame - sizeof(struct ntb_payload_header)) {
1507                 if (qp->tx_handler)
1508                         qp->tx_handler(qp->cb_data, qp, NULL, -EIO);
1509
1510                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1511                              &qp->tx_free_q);
1512                 return 0;
1513         }
1514
1515         ntb_async_tx(qp, entry);
1516
1517         qp->tx_index++;
1518         qp->tx_index %= qp->tx_max_entry;
1519
1520         qp->tx_pkts++;
1521
1522         return 0;
1523 }
1524
1525 static void ntb_send_link_down(struct ntb_transport_qp *qp)
1526 {
1527         struct pci_dev *pdev = qp->ndev->pdev;
1528         struct ntb_queue_entry *entry;
1529         int i, rc;
1530
1531         if (!qp->link_is_up)
1532                 return;
1533
1534         dev_info(&pdev->dev, "qp %d: Send Link Down\n", qp->qp_num);
1535
1536         for (i = 0; i < NTB_LINK_DOWN_TIMEOUT; i++) {
1537                 entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1538                 if (entry)
1539                         break;
1540                 msleep(100);
1541         }
1542
1543         if (!entry)
1544                 return;
1545
1546         entry->cb_data = NULL;
1547         entry->buf = NULL;
1548         entry->len = 0;
1549         entry->flags = LINK_DOWN_FLAG;
1550
1551         rc = ntb_process_tx(qp, entry);
1552         if (rc)
1553                 dev_err(&pdev->dev, "ntb: QP%d unable to send linkdown msg\n",
1554                         qp->qp_num);
1555
1556         ntb_qp_link_down_reset(qp);
1557 }
1558
1559 static bool ntb_dma_filter_fn(struct dma_chan *chan, void *node)
1560 {
1561         return dev_to_node(&chan->dev->device) == (int)(unsigned long)node;
1562 }
1563
1564 /**
1565  * ntb_transport_create_queue - Create a new NTB transport layer queue
1566  * @rx_handler: receive callback function
1567  * @tx_handler: transmit callback function
1568  * @event_handler: event callback function
1569  *
1570  * Create a new NTB transport layer queue and provide the queue with a callback
1571  * routine for both transmit and receive.  The receive callback routine will be
1572  * used to pass up data when the transport has received it on the queue.   The
1573  * transmit callback routine will be called when the transport has completed the
1574  * transmission of the data on the queue and the data is ready to be freed.
1575  *
1576  * RETURNS: pointer to newly created ntb_queue, NULL on error.
1577  */
1578 struct ntb_transport_qp *
1579 ntb_transport_create_queue(void *data, struct device *client_dev,
1580                            const struct ntb_queue_handlers *handlers)
1581 {
1582         struct ntb_dev *ndev;
1583         struct pci_dev *pdev;
1584         struct ntb_transport_ctx *nt;
1585         struct ntb_queue_entry *entry;
1586         struct ntb_transport_qp *qp;
1587         u64 qp_bit;
1588         unsigned int free_queue;
1589         dma_cap_mask_t dma_mask;
1590         int node;
1591         int i;
1592
1593         ndev = dev_ntb(client_dev->parent);
1594         pdev = ndev->pdev;
1595         nt = ndev->ctx;
1596
1597         node = dev_to_node(&ndev->dev);
1598
1599         free_queue = ffs(nt->qp_bitmap);
1600         if (!free_queue)
1601                 goto err;
1602
1603         /* decrement free_queue to make it zero based */
1604         free_queue--;
1605
1606         qp = &nt->qp_vec[free_queue];
1607         qp_bit = BIT_ULL(qp->qp_num);
1608
1609         nt->qp_bitmap_free &= ~qp_bit;
1610
1611         qp->cb_data = data;
1612         qp->rx_handler = handlers->rx_handler;
1613         qp->tx_handler = handlers->tx_handler;
1614         qp->event_handler = handlers->event_handler;
1615
1616         dma_cap_zero(dma_mask);
1617         dma_cap_set(DMA_MEMCPY, dma_mask);
1618
1619         if (use_dma) {
1620                 qp->dma_chan = dma_request_channel(dma_mask, ntb_dma_filter_fn,
1621                                                    (void *)(unsigned long)node);
1622                 if (!qp->dma_chan)
1623                         dev_info(&pdev->dev, "Unable to allocate DMA channel\n");
1624         } else {
1625                 qp->dma_chan = NULL;
1626         }
1627         dev_dbg(&pdev->dev, "Using %s memcpy\n", qp->dma_chan ? "DMA" : "CPU");
1628
1629         for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
1630                 entry = kzalloc_node(sizeof(*entry), GFP_ATOMIC, node);
1631                 if (!entry)
1632                         goto err1;
1633
1634                 entry->qp = qp;
1635                 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry,
1636                              &qp->rx_free_q);
1637         }
1638
1639         for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
1640                 entry = kzalloc_node(sizeof(*entry), GFP_ATOMIC, node);
1641                 if (!entry)
1642                         goto err2;
1643
1644                 entry->qp = qp;
1645                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1646                              &qp->tx_free_q);
1647         }
1648
1649         ntb_db_clear(qp->ndev, qp_bit);
1650         ntb_db_clear_mask(qp->ndev, qp_bit);
1651
1652         dev_info(&pdev->dev, "NTB Transport QP %d created\n", qp->qp_num);
1653
1654         return qp;
1655
1656 err2:
1657         while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1658                 kfree(entry);
1659 err1:
1660         while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
1661                 kfree(entry);
1662         if (qp->dma_chan)
1663                 dma_release_channel(qp->dma_chan);
1664         nt->qp_bitmap_free |= qp_bit;
1665 err:
1666         return NULL;
1667 }
1668 EXPORT_SYMBOL_GPL(ntb_transport_create_queue);
1669
1670 /**
1671  * ntb_transport_free_queue - Frees NTB transport queue
1672  * @qp: NTB queue to be freed
1673  *
1674  * Frees NTB transport queue
1675  */
1676 void ntb_transport_free_queue(struct ntb_transport_qp *qp)
1677 {
1678         struct ntb_transport_ctx *nt = qp->transport;
1679         struct pci_dev *pdev;
1680         struct ntb_queue_entry *entry;
1681         u64 qp_bit;
1682
1683         if (!qp)
1684                 return;
1685
1686         pdev = qp->ndev->pdev;
1687
1688         if (qp->dma_chan) {
1689                 struct dma_chan *chan = qp->dma_chan;
1690                 /* Putting the dma_chan to NULL will force any new traffic to be
1691                  * processed by the CPU instead of the DAM engine
1692                  */
1693                 qp->dma_chan = NULL;
1694
1695                 /* Try to be nice and wait for any queued DMA engine
1696                  * transactions to process before smashing it with a rock
1697                  */
1698                 dma_sync_wait(chan, qp->last_cookie);
1699                 dmaengine_terminate_all(chan);
1700                 dma_release_channel(chan);
1701         }
1702
1703         qp_bit = BIT_ULL(qp->qp_num);
1704
1705         ntb_db_set_mask(qp->ndev, qp_bit);
1706         tasklet_disable(&qp->rxc_db_work);
1707
1708         cancel_delayed_work_sync(&qp->link_work);
1709
1710         qp->cb_data = NULL;
1711         qp->rx_handler = NULL;
1712         qp->tx_handler = NULL;
1713         qp->event_handler = NULL;
1714
1715         while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
1716                 kfree(entry);
1717
1718         while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_pend_q))) {
1719                 dev_warn(&pdev->dev, "Freeing item from non-empty rx_pend_q\n");
1720                 kfree(entry);
1721         }
1722
1723         while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_post_q))) {
1724                 dev_warn(&pdev->dev, "Freeing item from non-empty rx_post_q\n");
1725                 kfree(entry);
1726         }
1727
1728         while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1729                 kfree(entry);
1730
1731         nt->qp_bitmap_free |= qp_bit;
1732
1733         dev_info(&pdev->dev, "NTB Transport QP %d freed\n", qp->qp_num);
1734 }
1735 EXPORT_SYMBOL_GPL(ntb_transport_free_queue);
1736
1737 /**
1738  * ntb_transport_rx_remove - Dequeues enqueued rx packet
1739  * @qp: NTB queue to be freed
1740  * @len: pointer to variable to write enqueued buffers length
1741  *
1742  * Dequeues unused buffers from receive queue.  Should only be used during
1743  * shutdown of qp.
1744  *
1745  * RETURNS: NULL error value on error, or void* for success.
1746  */
1747 void *ntb_transport_rx_remove(struct ntb_transport_qp *qp, unsigned int *len)
1748 {
1749         struct ntb_queue_entry *entry;
1750         void *buf;
1751
1752         if (!qp || qp->client_ready)
1753                 return NULL;
1754
1755         entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_pend_q);
1756         if (!entry)
1757                 return NULL;
1758
1759         buf = entry->cb_data;
1760         *len = entry->len;
1761
1762         ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_free_q);
1763
1764         return buf;
1765 }
1766 EXPORT_SYMBOL_GPL(ntb_transport_rx_remove);
1767
1768 /**
1769  * ntb_transport_rx_enqueue - Enqueue a new NTB queue entry
1770  * @qp: NTB transport layer queue the entry is to be enqueued on
1771  * @cb: per buffer pointer for callback function to use
1772  * @data: pointer to data buffer that incoming packets will be copied into
1773  * @len: length of the data buffer
1774  *
1775  * Enqueue a new receive buffer onto the transport queue into which a NTB
1776  * payload can be received into.
1777  *
1778  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
1779  */
1780 int ntb_transport_rx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
1781                              unsigned int len)
1782 {
1783         struct ntb_queue_entry *entry;
1784
1785         if (!qp)
1786                 return -EINVAL;
1787
1788         entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q);
1789         if (!entry)
1790                 return -ENOMEM;
1791
1792         entry->cb_data = cb;
1793         entry->buf = data;
1794         entry->len = len;
1795         entry->flags = 0;
1796
1797         ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_pend_q);
1798
1799         tasklet_schedule(&qp->rxc_db_work);
1800
1801         return 0;
1802 }
1803 EXPORT_SYMBOL_GPL(ntb_transport_rx_enqueue);
1804
1805 /**
1806  * ntb_transport_tx_enqueue - Enqueue a new NTB queue entry
1807  * @qp: NTB transport layer queue the entry is to be enqueued on
1808  * @cb: per buffer pointer for callback function to use
1809  * @data: pointer to data buffer that will be sent
1810  * @len: length of the data buffer
1811  *
1812  * Enqueue a new transmit buffer onto the transport queue from which a NTB
1813  * payload will be transmitted.  This assumes that a lock is being held to
1814  * serialize access to the qp.
1815  *
1816  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
1817  */
1818 int ntb_transport_tx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
1819                              unsigned int len)
1820 {
1821         struct ntb_queue_entry *entry;
1822         int rc;
1823
1824         if (!qp || !qp->link_is_up || !len)
1825                 return -EINVAL;
1826
1827         entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1828         if (!entry) {
1829                 qp->tx_err_no_buf++;
1830                 return -ENOMEM;
1831         }
1832
1833         entry->cb_data = cb;
1834         entry->buf = data;
1835         entry->len = len;
1836         entry->flags = 0;
1837
1838         rc = ntb_process_tx(qp, entry);
1839         if (rc)
1840                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1841                              &qp->tx_free_q);
1842
1843         return rc;
1844 }
1845 EXPORT_SYMBOL_GPL(ntb_transport_tx_enqueue);
1846
1847 /**
1848  * ntb_transport_link_up - Notify NTB transport of client readiness to use queue
1849  * @qp: NTB transport layer queue to be enabled
1850  *
1851  * Notify NTB transport layer of client readiness to use queue
1852  */
1853 void ntb_transport_link_up(struct ntb_transport_qp *qp)
1854 {
1855         if (!qp)
1856                 return;
1857
1858         qp->client_ready = true;
1859
1860         if (qp->transport->link_is_up)
1861                 schedule_delayed_work(&qp->link_work, 0);
1862 }
1863 EXPORT_SYMBOL_GPL(ntb_transport_link_up);
1864
1865 /**
1866  * ntb_transport_link_down - Notify NTB transport to no longer enqueue data
1867  * @qp: NTB transport layer queue to be disabled
1868  *
1869  * Notify NTB transport layer of client's desire to no longer receive data on
1870  * transport queue specified.  It is the client's responsibility to ensure all
1871  * entries on queue are purged or otherwise handled appropriately.
1872  */
1873 void ntb_transport_link_down(struct ntb_transport_qp *qp)
1874 {
1875         struct pci_dev *pdev;
1876         int val;
1877
1878         if (!qp)
1879                 return;
1880
1881         pdev = qp->ndev->pdev;
1882         qp->client_ready = false;
1883
1884         val = ntb_spad_read(qp->ndev, QP_LINKS);
1885
1886         ntb_peer_spad_write(qp->ndev, QP_LINKS,
1887                             val & ~BIT(qp->qp_num));
1888
1889         if (qp->link_is_up)
1890                 ntb_send_link_down(qp);
1891         else
1892                 cancel_delayed_work_sync(&qp->link_work);
1893 }
1894 EXPORT_SYMBOL_GPL(ntb_transport_link_down);
1895
1896 /**
1897  * ntb_transport_link_query - Query transport link state
1898  * @qp: NTB transport layer queue to be queried
1899  *
1900  * Query connectivity to the remote system of the NTB transport queue
1901  *
1902  * RETURNS: true for link up or false for link down
1903  */
1904 bool ntb_transport_link_query(struct ntb_transport_qp *qp)
1905 {
1906         if (!qp)
1907                 return false;
1908
1909         return qp->link_is_up;
1910 }
1911 EXPORT_SYMBOL_GPL(ntb_transport_link_query);
1912
1913 /**
1914  * ntb_transport_qp_num - Query the qp number
1915  * @qp: NTB transport layer queue to be queried
1916  *
1917  * Query qp number of the NTB transport queue
1918  *
1919  * RETURNS: a zero based number specifying the qp number
1920  */
1921 unsigned char ntb_transport_qp_num(struct ntb_transport_qp *qp)
1922 {
1923         if (!qp)
1924                 return 0;
1925
1926         return qp->qp_num;
1927 }
1928 EXPORT_SYMBOL_GPL(ntb_transport_qp_num);
1929
1930 /**
1931  * ntb_transport_max_size - Query the max payload size of a qp
1932  * @qp: NTB transport layer queue to be queried
1933  *
1934  * Query the maximum payload size permissible on the given qp
1935  *
1936  * RETURNS: the max payload size of a qp
1937  */
1938 unsigned int ntb_transport_max_size(struct ntb_transport_qp *qp)
1939 {
1940         unsigned int max;
1941
1942         if (!qp)
1943                 return 0;
1944
1945         if (!qp->dma_chan)
1946                 return qp->tx_max_frame - sizeof(struct ntb_payload_header);
1947
1948         /* If DMA engine usage is possible, try to find the max size for that */
1949         max = qp->tx_max_frame - sizeof(struct ntb_payload_header);
1950         max -= max % (1 << qp->dma_chan->device->copy_align);
1951
1952         return max;
1953 }
1954 EXPORT_SYMBOL_GPL(ntb_transport_max_size);
1955
1956 static void ntb_transport_doorbell_callback(void *data, int vector)
1957 {
1958         struct ntb_transport_ctx *nt = data;
1959         struct ntb_transport_qp *qp;
1960         u64 db_bits;
1961         unsigned int qp_num;
1962
1963         db_bits = (nt->qp_bitmap & ~nt->qp_bitmap_free &
1964                    ntb_db_vector_mask(nt->ndev, vector));
1965
1966         while (db_bits) {
1967                 qp_num = __ffs(db_bits);
1968                 qp = &nt->qp_vec[qp_num];
1969
1970                 tasklet_schedule(&qp->rxc_db_work);
1971
1972                 db_bits &= ~BIT_ULL(qp_num);
1973         }
1974 }
1975
1976 static const struct ntb_ctx_ops ntb_transport_ops = {
1977         .link_event = ntb_transport_event_callback,
1978         .db_event = ntb_transport_doorbell_callback,
1979 };
1980
1981 static struct ntb_client ntb_transport_client = {
1982         .ops = {
1983                 .probe = ntb_transport_probe,
1984                 .remove = ntb_transport_free,
1985         },
1986 };
1987
1988 static int __init ntb_transport_init(void)
1989 {
1990         int rc;
1991
1992         pr_info("%s, version %s\n", NTB_TRANSPORT_DESC, NTB_TRANSPORT_VER);
1993
1994         if (debugfs_initialized())
1995                 nt_debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
1996
1997         rc = bus_register(&ntb_transport_bus);
1998         if (rc)
1999                 goto err_bus;
2000
2001         rc = ntb_register_client(&ntb_transport_client);
2002         if (rc)
2003                 goto err_client;
2004
2005         return 0;
2006
2007 err_client:
2008         bus_unregister(&ntb_transport_bus);
2009 err_bus:
2010         debugfs_remove_recursive(nt_debugfs_dir);
2011         return rc;
2012 }
2013 module_init(ntb_transport_init);
2014
2015 static void __exit ntb_transport_exit(void)
2016 {
2017         debugfs_remove_recursive(nt_debugfs_dir);
2018
2019         ntb_unregister_client(&ntb_transport_client);
2020         bus_unregister(&ntb_transport_bus);
2021 }
2022 module_exit(ntb_transport_exit);