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         int retries;
 106         int errors;
 107         unsigned int tx_index;
 108         unsigned int rx_index;
 109
 110         struct ntb_transport_qp *qp;
 111         union {
 112                 struct ntb_payload_header __iomem *tx_hdr;
 113                 struct ntb_payload_header *rx_hdr;
 114         };
 115 };
 116
 117 struct ntb_rx_info {
 118         unsigned int entry;
 119 };
 120
 121 struct ntb_transport_qp {
 122         struct ntb_transport_ctx *transport;
 123         struct ntb_dev *ndev;
 124         void *cb_data;
 125         struct dma_chan *tx_dma_chan;
 126         struct dma_chan *rx_dma_chan;
 127
 128         bool client_ready;
 129         bool link_is_up;
 130         bool active;
 131
 132         u8 qp_num;      /* Only 64 QP's are allowed.  0-63 */
 133         u64 qp_bit;
 134
 135         struct ntb_rx_info __iomem *rx_info;
 136         struct ntb_rx_info *remote_rx_info;
 137
 138         void (*tx_handler)(struct ntb_transport_qp *qp, void *qp_data,
 139                            void *data, int len);
 140         struct list_head tx_free_q;
 141         spinlock_t ntb_tx_free_q_lock;
 142         void __iomem *tx_mw;
 143         dma_addr_t tx_mw_phys;
 144         unsigned int tx_index;
 145         unsigned int tx_max_entry;
 146         unsigned int tx_max_frame;
 147
 148         void (*rx_handler)(struct ntb_transport_qp *qp, void *qp_data,
 149                            void *data, int len);
 150         struct list_head rx_post_q;
 151         struct list_head rx_pend_q;
 152         struct list_head rx_free_q;
 153         /* ntb_rx_q_lock: synchronize access to rx_XXXX_q */
 154         spinlock_t ntb_rx_q_lock;
 155         void *rx_buff;
 156         unsigned int rx_index;
 157         unsigned int rx_max_entry;
 158         unsigned int rx_max_frame;
 159         unsigned int rx_alloc_entry;
 160         dma_cookie_t last_cookie;
 161         struct tasklet_struct rxc_db_work;
 162
 163         void (*event_handler)(void *data, int status);
 164         struct delayed_work link_work;
 165         struct work_struct link_cleanup;
 166
 167         struct dentry *debugfs_dir;
 168         struct dentry *debugfs_stats;
 169
 170         /* Stats */
 171         u64 rx_bytes;
 172         u64 rx_pkts;
 173         u64 rx_ring_empty;
 174         u64 rx_err_no_buf;
 175         u64 rx_err_oflow;
 176         u64 rx_err_ver;
 177         u64 rx_memcpy;
 178         u64 rx_async;
 179         u64 dma_rx_prep_err;
 180         u64 tx_bytes;
 181         u64 tx_pkts;
 182         u64 tx_ring_full;
 183         u64 tx_err_no_buf;
 184         u64 tx_memcpy;
 185         u64 tx_async;
 186         u64 dma_tx_prep_err;
 187 };
 188
 189 struct ntb_transport_mw {
 190         phys_addr_t phys_addr;
 191         resource_size_t phys_size;
 192         resource_size_t xlat_align;
 193         resource_size_t xlat_align_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         MW1_SZ_HIGH,
 246         MW1_SZ_LOW,
 247         MAX_SPAD,
 248 };
 249
 250 #define dev_client_dev(__dev) \
 251         container_of((__dev), struct ntb_transport_client_dev, dev)
 252
 253 #define drv_client(__drv) \
 254         container_of((__drv), struct ntb_transport_client, driver)
 255
 256 #define QP_TO_MW(nt, qp)        ((qp) % nt->mw_count)
 257 #define NTB_QP_DEF_NUM_ENTRIES  100
 258 #define NTB_LINK_DOWN_TIMEOUT   10
 259 #define DMA_RETRIES             20
 260 #define DMA_OUT_RESOURCE_TO     msecs_to_jiffies(50)
 261
 262 static void ntb_transport_rxc_db(unsigned long data);
 263 static const struct ntb_ctx_ops ntb_transport_ops;
 264 static struct ntb_client ntb_transport_client;
 265 static int ntb_async_tx_submit(struct ntb_transport_qp *qp,
 266                                struct ntb_queue_entry *entry);
 267 static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset);
 268 static int ntb_async_rx_submit(struct ntb_queue_entry *entry, void *offset);
 269 static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void *offset);
 270
 271
 272 static int ntb_transport_bus_match(struct device *dev,
 273                                    struct device_driver *drv)
 274 {
 275         return !strncmp(dev_name(dev), drv->name, strlen(drv->name));
 276 }
 277
 278 static int ntb_transport_bus_probe(struct device *dev)
 279 {
 280         const struct ntb_transport_client *client;
 281         int rc = -EINVAL;
 282
 283         get_device(dev);
 284
 285         client = drv_client(dev->driver);
 286         rc = client->probe(dev);
 287         if (rc)
 288                 put_device(dev);
 289
 290         return rc;
 291 }
 292
 293 static int ntb_transport_bus_remove(struct device *dev)
 294 {
 295         const struct ntb_transport_client *client;
 296
 297         client = drv_client(dev->driver);
 298         client->remove(dev);
 299
 300         put_device(dev);
 301
 302         return 0;
 303 }
 304
 305 static struct bus_type ntb_transport_bus = {
 306         .name = "ntb_transport",
 307         .match = ntb_transport_bus_match,
 308         .probe = ntb_transport_bus_probe,
 309         .remove = ntb_transport_bus_remove,
 310 };
 311
 312 static LIST_HEAD(ntb_transport_list);
 313
 314 static int ntb_bus_init(struct ntb_transport_ctx *nt)
 315 {
 316         list_add_tail(&nt->entry, &ntb_transport_list);
 317         return 0;
 318 }
 319
 320 static void ntb_bus_remove(struct ntb_transport_ctx *nt)
 321 {
 322         struct ntb_transport_client_dev *client_dev, *cd;
 323
 324         list_for_each_entry_safe(client_dev, cd, &nt->client_devs, entry) {
 325                 dev_err(client_dev->dev.parent, "%s still attached to bus, removing\n",
 326                         dev_name(&client_dev->dev));
 327                 list_del(&client_dev->entry);
 328                 device_unregister(&client_dev->dev);
 329         }
 330
 331         list_del(&nt->entry);
 332 }
 333
 334 static void ntb_transport_client_release(struct device *dev)
 335 {
 336         struct ntb_transport_client_dev *client_dev;
 337
 338         client_dev = dev_client_dev(dev);
 339         kfree(client_dev);
 340 }
 341
 342 /**
 343  * ntb_transport_unregister_client_dev - Unregister NTB client device
 344  * @device_name: Name of NTB client device
 345  *
 346  * Unregister an NTB client device with the NTB transport layer
 347  */
 348 void ntb_transport_unregister_client_dev(char *device_name)
 349 {
 350         struct ntb_transport_client_dev *client, *cd;
 351         struct ntb_transport_ctx *nt;
 352
 353         list_for_each_entry(nt, &ntb_transport_list, entry)
 354                 list_for_each_entry_safe(client, cd, &nt->client_devs, entry)
 355                         if (!strncmp(dev_name(&client->dev), device_name,
 356                                      strlen(device_name))) {
 357                                 list_del(&client->entry);
 358                                 device_unregister(&client->dev);
 359                         }
 360 }
 361 EXPORT_SYMBOL_GPL(ntb_transport_unregister_client_dev);
 362
 363 /**
 364  * ntb_transport_register_client_dev - Register NTB client device
 365  * @device_name: Name of NTB client device
 366  *
 367  * Register an NTB client device with the NTB transport layer
 368  */
 369 int ntb_transport_register_client_dev(char *device_name)
 370 {
 371         struct ntb_transport_client_dev *client_dev;
 372         struct ntb_transport_ctx *nt;
 373         int node;
 374         int rc, i = 0;
 375
 376         if (list_empty(&ntb_transport_list))
 377                 return -ENODEV;
 378
 379         list_for_each_entry(nt, &ntb_transport_list, entry) {
 380                 struct device *dev;
 381
 382                 node = dev_to_node(&nt->ndev->dev);
 383
 384                 client_dev = kzalloc_node(sizeof(*client_dev),
 385                                           GFP_KERNEL, node);
 386                 if (!client_dev) {
 387                         rc = -ENOMEM;
 388                         goto err;
 389                 }
 390
 391                 dev = &client_dev->dev;
 392
 393                 /* setup and register client devices */
 394                 dev_set_name(dev, "%s%d", device_name, i);
 395                 dev->bus = &ntb_transport_bus;
 396                 dev->release = ntb_transport_client_release;
 397                 dev->parent = &nt->ndev->dev;
 398
 399                 rc = device_register(dev);
 400                 if (rc) {
 401                         kfree(client_dev);
 402                         goto err;
 403                 }
 404
 405                 list_add_tail(&client_dev->entry, &nt->client_devs);
 406                 i++;
 407         }
 408
 409         return 0;
 410
 411 err:
 412         ntb_transport_unregister_client_dev(device_name);
 413
 414         return rc;
 415 }
 416 EXPORT_SYMBOL_GPL(ntb_transport_register_client_dev);
 417
 418 /**
 419  * ntb_transport_register_client - Register NTB client driver
 420  * @drv: NTB client driver to be registered
 421  *
 422  * Register an NTB client driver with the NTB transport layer
 423  *
 424  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 425  */
 426 int ntb_transport_register_client(struct ntb_transport_client *drv)
 427 {
 428         drv->driver.bus = &ntb_transport_bus;
 429
 430         if (list_empty(&ntb_transport_list))
 431                 return -ENODEV;
 432
 433         return driver_register(&drv->driver);
 434 }
 435 EXPORT_SYMBOL_GPL(ntb_transport_register_client);
 436
 437 /**
 438  * ntb_transport_unregister_client - Unregister NTB client driver
 439  * @drv: NTB client driver to be unregistered
 440  *
 441  * Unregister an NTB client driver with the NTB transport layer
 442  *
 443  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 444  */
 445 void ntb_transport_unregister_client(struct ntb_transport_client *drv)
 446 {
 447         driver_unregister(&drv->driver);
 448 }
 449 EXPORT_SYMBOL_GPL(ntb_transport_unregister_client);
 450
 451 static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count,
 452                             loff_t *offp)
 453 {
 454         struct ntb_transport_qp *qp;
 455         char *buf;
 456         ssize_t ret, out_offset, out_count;
 457
 458         qp = filp->private_data;
 459
 460         if (!qp || !qp->link_is_up)
 461                 return 0;
 462
 463         out_count = 1000;
 464
 465         buf = kmalloc(out_count, GFP_KERNEL);
 466         if (!buf)
 467                 return -ENOMEM;
 468
 469         out_offset = 0;
 470         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 471                                "\nNTB QP stats:\n\n");
 472         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 473                                "rx_bytes - \t%llu\n", qp->rx_bytes);
 474         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 475                                "rx_pkts - \t%llu\n", qp->rx_pkts);
 476         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 477                                "rx_memcpy - \t%llu\n", qp->rx_memcpy);
 478         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 479                                "rx_async - \t%llu\n", qp->rx_async);
 480         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 481                                "rx_ring_empty - %llu\n", qp->rx_ring_empty);
 482         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 483                                "rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
 484         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 485                                "rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
 486         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 487                                "rx_err_ver - \t%llu\n", qp->rx_err_ver);
 488         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 489                                "rx_buff - \t0x%p\n", qp->rx_buff);
 490         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 491                                "rx_index - \t%u\n", qp->rx_index);
 492         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 493                                "rx_max_entry - \t%u\n", qp->rx_max_entry);
 494         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 495                                "rx_alloc_entry - \t%u\n\n", qp->rx_alloc_entry);
 496
 497         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 498                                "tx_bytes - \t%llu\n", qp->tx_bytes);
 499         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 500                                "tx_pkts - \t%llu\n", qp->tx_pkts);
 501         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 502                                "tx_memcpy - \t%llu\n", qp->tx_memcpy);
 503         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 504                                "tx_async - \t%llu\n", qp->tx_async);
 505         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 506                                "tx_ring_full - \t%llu\n", qp->tx_ring_full);
 507         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 508                                "tx_err_no_buf - %llu\n", qp->tx_err_no_buf);
 509         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 510                                "tx_mw - \t0x%p\n", qp->tx_mw);
 511         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 512                                "tx_index (H) - \t%u\n", qp->tx_index);
 513         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 514                                "RRI (T) - \t%u\n",
 515                                qp->remote_rx_info->entry);
 516         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 517                                "tx_max_entry - \t%u\n", qp->tx_max_entry);
 518         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 519                                "free tx - \t%u\n",
 520                                ntb_transport_tx_free_entry(qp));
 521         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 522                                "DMA tx prep err - \t%llu\n",
 523                                qp->dma_tx_prep_err);
 524         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 525                                "DMA rx prep err - \t%llu\n",
 526                                qp->dma_rx_prep_err);
 527
 528         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 529                                "\n");
 530         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 531                                "Using TX DMA - \t%s\n",
 532                                qp->tx_dma_chan ? "Yes" : "No");
 533         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 534                                "Using RX DMA - \t%s\n",
 535                                qp->rx_dma_chan ? "Yes" : "No");
 536         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 537                                "QP Link - \t%s\n",
 538                                qp->link_is_up ? "Up" : "Down");
 539         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 540                                "\n");
 541
 542         if (out_offset > out_count)
 543                 out_offset = out_count;
 544
 545         ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
 546         kfree(buf);
 547         return ret;
 548 }
 549
 550 static const struct file_operations ntb_qp_debugfs_stats = {
 551         .owner = THIS_MODULE,
 552         .open = simple_open,
 553         .read = debugfs_read,
 554 };
 555
 556 static void ntb_list_add(spinlock_t *lock, struct list_head *entry,
 557                          struct list_head *list)
 558 {
 559         unsigned long flags;
 560
 561         spin_lock_irqsave(lock, flags);
 562         list_add_tail(entry, list);
 563         spin_unlock_irqrestore(lock, flags);
 564 }
 565
 566 static struct ntb_queue_entry *ntb_list_rm(spinlock_t *lock,
 567                                            struct list_head *list)
 568 {
 569         struct ntb_queue_entry *entry;
 570         unsigned long flags;
 571
 572         spin_lock_irqsave(lock, flags);
 573         if (list_empty(list)) {
 574                 entry = NULL;
 575                 goto out;
 576         }
 577         entry = list_first_entry(list, struct ntb_queue_entry, entry);
 578         list_del(&entry->entry);
 579
 580 out:
 581         spin_unlock_irqrestore(lock, flags);
 582
 583         return entry;
 584 }
 585
 586 static struct ntb_queue_entry *ntb_list_mv(spinlock_t *lock,
 587                                            struct list_head *list,
 588                                            struct list_head *to_list)
 589 {
 590         struct ntb_queue_entry *entry;
 591         unsigned long flags;
 592
 593         spin_lock_irqsave(lock, flags);
 594
 595         if (list_empty(list)) {
 596                 entry = NULL;
 597         } else {
 598                 entry = list_first_entry(list, struct ntb_queue_entry, entry);
 599                 list_move_tail(&entry->entry, to_list);
 600         }
 601
 602         spin_unlock_irqrestore(lock, flags);
 603
 604         return entry;
 605 }
 606
 607 static int ntb_transport_setup_qp_mw(struct ntb_transport_ctx *nt,
 608                                      unsigned int qp_num)
 609 {
 610         struct ntb_transport_qp *qp = &nt->qp_vec[qp_num];
 611         struct ntb_transport_mw *mw;
 612         struct ntb_dev *ndev = nt->ndev;
 613         struct ntb_queue_entry *entry;
 614         unsigned int rx_size, num_qps_mw;
 615         unsigned int mw_num, mw_count, qp_count;
 616         unsigned int i;
 617         int node;
 618
 619         mw_count = nt->mw_count;
 620         qp_count = nt->qp_count;
 621
 622         mw_num = QP_TO_MW(nt, qp_num);
 623         mw = &nt->mw_vec[mw_num];
 624
 625         if (!mw->virt_addr)
 626                 return -ENOMEM;
 627
 628         if (qp_count % mw_count && mw_num + 1 < qp_count / mw_count)
 629                 num_qps_mw = qp_count / mw_count + 1;
 630         else
 631                 num_qps_mw = qp_count / mw_count;
 632
 633         rx_size = (unsigned int)mw->xlat_size / num_qps_mw;
 634         qp->rx_buff = mw->virt_addr + rx_size * (qp_num / mw_count);
 635         rx_size -= sizeof(struct ntb_rx_info);
 636
 637         qp->remote_rx_info = qp->rx_buff + rx_size;
 638
 639         /* Due to housekeeping, there must be atleast 2 buffs */
 640         qp->rx_max_frame = min(transport_mtu, rx_size / 2);
 641         qp->rx_max_entry = rx_size / qp->rx_max_frame;
 642         qp->rx_index = 0;
 643
 644         /*
 645          * Checking to see if we have more entries than the default.
 646          * We should add additional entries if that is the case so we
 647          * can be in sync with the transport frames.
 648          */
 649         node = dev_to_node(&ndev->dev);
 650         for (i = qp->rx_alloc_entry; i < qp->rx_max_entry; i++) {
 651                 entry = kzalloc_node(sizeof(*entry), GFP_ATOMIC, node);
 652                 if (!entry)
 653                         return -ENOMEM;
 654
 655                 entry->qp = qp;
 656                 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry,
 657                              &qp->rx_free_q);
 658                 qp->rx_alloc_entry++;
 659         }
 660
 661         qp->remote_rx_info->entry = qp->rx_max_entry - 1;
 662
 663         /* setup the hdr offsets with 0's */
 664         for (i = 0; i < qp->rx_max_entry; i++) {
 665                 void *offset = (qp->rx_buff + qp->rx_max_frame * (i + 1) -
 666                                 sizeof(struct ntb_payload_header));
 667                 memset(offset, 0, sizeof(struct ntb_payload_header));
 668         }
 669
 670         qp->rx_pkts = 0;
 671         qp->tx_pkts = 0;
 672         qp->tx_index = 0;
 673
 674         return 0;
 675 }
 676
 677 static void ntb_free_mw(struct ntb_transport_ctx *nt, int num_mw)
 678 {
 679         struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
 680         struct pci_dev *pdev = nt->ndev->pdev;
 681
 682         if (!mw->virt_addr)
 683                 return;
 684
 685         ntb_mw_clear_trans(nt->ndev, num_mw);
 686         dma_free_coherent(&pdev->dev, mw->buff_size,
 687                           mw->virt_addr, mw->dma_addr);
 688         mw->xlat_size = 0;
 689         mw->buff_size = 0;
 690         mw->virt_addr = NULL;
 691 }
 692
 693 static int ntb_set_mw(struct ntb_transport_ctx *nt, int num_mw,
 694                       resource_size_t size)
 695 {
 696         struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
 697         struct pci_dev *pdev = nt->ndev->pdev;
 698         size_t xlat_size, buff_size;
 699         int rc;
 700
 701         if (!size)
 702                 return -EINVAL;
 703
 704         xlat_size = round_up(size, mw->xlat_align_size);
 705         buff_size = round_up(size, mw->xlat_align);
 706
 707         /* No need to re-setup */
 708         if (mw->xlat_size == xlat_size)
 709                 return 0;
 710
 711         if (mw->buff_size)
 712                 ntb_free_mw(nt, num_mw);
 713
 714         /* Alloc memory for receiving data.  Must be aligned */
 715         mw->xlat_size = xlat_size;
 716         mw->buff_size = buff_size;
 717
 718         mw->virt_addr = dma_alloc_coherent(&pdev->dev, buff_size,
 719                                            &mw->dma_addr, GFP_KERNEL);
 720         if (!mw->virt_addr) {
 721                 mw->xlat_size = 0;
 722                 mw->buff_size = 0;
 723                 dev_err(&pdev->dev, "Unable to alloc MW buff of size %zu\n",
 724                         buff_size);
 725                 return -ENOMEM;
 726         }
 727
 728         /*
 729          * we must ensure that the memory address allocated is BAR size
 730          * aligned in order for the XLAT register to take the value. This
 731          * is a requirement of the hardware. It is recommended to setup CMA
 732          * for BAR sizes equal or greater than 4MB.
 733          */
 734         if (!IS_ALIGNED(mw->dma_addr, mw->xlat_align)) {
 735                 dev_err(&pdev->dev, "DMA memory %pad is not aligned\n",
 736                         &mw->dma_addr);
 737                 ntb_free_mw(nt, num_mw);
 738                 return -ENOMEM;
 739         }
 740
 741         /* Notify HW the memory location of the receive buffer */
 742         rc = ntb_mw_set_trans(nt->ndev, num_mw, mw->dma_addr, mw->xlat_size);
 743         if (rc) {
 744                 dev_err(&pdev->dev, "Unable to set mw%d translation", num_mw);
 745                 ntb_free_mw(nt, num_mw);
 746                 return -EIO;
 747         }
 748
 749         return 0;
 750 }
 751
 752 static void ntb_qp_link_down_reset(struct ntb_transport_qp *qp)
 753 {
 754         qp->link_is_up = false;
 755         qp->active = false;
 756
 757         qp->tx_index = 0;
 758         qp->rx_index = 0;
 759         qp->rx_bytes = 0;
 760         qp->rx_pkts = 0;
 761         qp->rx_ring_empty = 0;
 762         qp->rx_err_no_buf = 0;
 763         qp->rx_err_oflow = 0;
 764         qp->rx_err_ver = 0;
 765         qp->rx_memcpy = 0;
 766         qp->rx_async = 0;
 767         qp->tx_bytes = 0;
 768         qp->tx_pkts = 0;
 769         qp->tx_ring_full = 0;
 770         qp->tx_err_no_buf = 0;
 771         qp->tx_memcpy = 0;
 772         qp->tx_async = 0;
 773         qp->dma_tx_prep_err = 0;
 774         qp->dma_rx_prep_err = 0;
 775 }
 776
 777 static void ntb_qp_link_cleanup(struct ntb_transport_qp *qp)
 778 {
 779         struct ntb_transport_ctx *nt = qp->transport;
 780         struct pci_dev *pdev = nt->ndev->pdev;
 781
 782         dev_info(&pdev->dev, "qp %d: Link Cleanup\n", qp->qp_num);
 783
 784         cancel_delayed_work_sync(&qp->link_work);
 785         ntb_qp_link_down_reset(qp);
 786
 787         if (qp->event_handler)
 788                 qp->event_handler(qp->cb_data, qp->link_is_up);
 789 }
 790
 791 static void ntb_qp_link_cleanup_work(struct work_struct *work)
 792 {
 793         struct ntb_transport_qp *qp = container_of(work,
 794                                                    struct ntb_transport_qp,
 795                                                    link_cleanup);
 796         struct ntb_transport_ctx *nt = qp->transport;
 797
 798         ntb_qp_link_cleanup(qp);
 799
 800         if (nt->link_is_up)
 801                 schedule_delayed_work(&qp->link_work,
 802                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 803 }
 804
 805 static void ntb_qp_link_down(struct ntb_transport_qp *qp)
 806 {
 807         schedule_work(&qp->link_cleanup);
 808 }
 809
 810 static void ntb_transport_link_cleanup(struct ntb_transport_ctx *nt)
 811 {
 812         struct ntb_transport_qp *qp;
 813         u64 qp_bitmap_alloc;
 814         int i;
 815
 816         qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
 817
 818         /* Pass along the info to any clients */
 819         for (i = 0; i < nt->qp_count; i++)
 820                 if (qp_bitmap_alloc & BIT_ULL(i)) {
 821                         qp = &nt->qp_vec[i];
 822                         ntb_qp_link_cleanup(qp);
 823                         cancel_work_sync(&qp->link_cleanup);
 824                         cancel_delayed_work_sync(&qp->link_work);
 825                 }
 826
 827         if (!nt->link_is_up)
 828                 cancel_delayed_work_sync(&nt->link_work);
 829
 830         /* The scratchpad registers keep the values if the remote side
 831          * goes down, blast them now to give them a sane value the next
 832          * time they are accessed
 833          */
 834         for (i = 0; i < MAX_SPAD; i++)
 835                 ntb_spad_write(nt->ndev, i, 0);
 836 }
 837
 838 static void ntb_transport_link_cleanup_work(struct work_struct *work)
 839 {
 840         struct ntb_transport_ctx *nt =
 841                 container_of(work, struct ntb_transport_ctx, link_cleanup);
 842
 843         ntb_transport_link_cleanup(nt);
 844 }
 845
 846 static void ntb_transport_event_callback(void *data)
 847 {
 848         struct ntb_transport_ctx *nt = data;
 849
 850         if (ntb_link_is_up(nt->ndev, NULL, NULL) == 1)
 851                 schedule_delayed_work(&nt->link_work, 0);
 852         else
 853                 schedule_work(&nt->link_cleanup);
 854 }
 855
 856 static void ntb_transport_link_work(struct work_struct *work)
 857 {
 858         struct ntb_transport_ctx *nt =
 859                 container_of(work, struct ntb_transport_ctx, link_work.work);
 860         struct ntb_dev *ndev = nt->ndev;
 861         struct pci_dev *pdev = ndev->pdev;
 862         resource_size_t size;
 863         u32 val;
 864         int rc = 0, i, spad;
 865
 866         /* send the local info, in the opposite order of the way we read it */
 867         for (i = 0; i < nt->mw_count; i++) {
 868                 size = nt->mw_vec[i].phys_size;
 869
 870                 if (max_mw_size && size > max_mw_size)
 871                         size = max_mw_size;
 872
 873                 spad = MW0_SZ_HIGH + (i * 2);
 874                 ntb_peer_spad_write(ndev, spad, upper_32_bits(size));
 875
 876                 spad = MW0_SZ_LOW + (i * 2);
 877                 ntb_peer_spad_write(ndev, spad, lower_32_bits(size));
 878         }
 879
 880         ntb_peer_spad_write(ndev, NUM_MWS, nt->mw_count);
 881
 882         ntb_peer_spad_write(ndev, NUM_QPS, nt->qp_count);
 883
 884         ntb_peer_spad_write(ndev, VERSION, NTB_TRANSPORT_VERSION);
 885
 886         /* Query the remote side for its info */
 887         val = ntb_spad_read(ndev, VERSION);
 888         dev_dbg(&pdev->dev, "Remote version = %d\n", val);
 889         if (val != NTB_TRANSPORT_VERSION)
 890                 goto out;
 891
 892         val = ntb_spad_read(ndev, NUM_QPS);
 893         dev_dbg(&pdev->dev, "Remote max number of qps = %d\n", val);
 894         if (val != nt->qp_count)
 895                 goto out;
 896
 897         val = ntb_spad_read(ndev, NUM_MWS);
 898         dev_dbg(&pdev->dev, "Remote number of mws = %d\n", val);
 899         if (val != nt->mw_count)
 900                 goto out;
 901
 902         for (i = 0; i < nt->mw_count; i++) {
 903                 u64 val64;
 904
 905                 val = ntb_spad_read(ndev, MW0_SZ_HIGH + (i * 2));
 906                 val64 = (u64)val << 32;
 907
 908                 val = ntb_spad_read(ndev, MW0_SZ_LOW + (i * 2));
 909                 val64 |= val;
 910
 911                 dev_dbg(&pdev->dev, "Remote MW%d size = %#llx\n", i, val64);
 912
 913                 rc = ntb_set_mw(nt, i, val64);
 914                 if (rc)
 915                         goto out1;
 916         }
 917
 918         nt->link_is_up = true;
 919
 920         for (i = 0; i < nt->qp_count; i++) {
 921                 struct ntb_transport_qp *qp = &nt->qp_vec[i];
 922
 923                 ntb_transport_setup_qp_mw(nt, i);
 924
 925                 if (qp->client_ready)
 926                         schedule_delayed_work(&qp->link_work, 0);
 927         }
 928
 929         return;
 930
 931 out1:
 932         for (i = 0; i < nt->mw_count; i++)
 933                 ntb_free_mw(nt, i);
 934
 935         /* if there's an actual failure, we should just bail */
 936         if (rc < 0) {
 937                 ntb_link_disable(ndev);
 938                 return;
 939         }
 940
 941 out:
 942         if (ntb_link_is_up(ndev, NULL, NULL) == 1)
 943                 schedule_delayed_work(&nt->link_work,
 944                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 945 }
 946
 947 static void ntb_qp_link_work(struct work_struct *work)
 948 {
 949         struct ntb_transport_qp *qp = container_of(work,
 950                                                    struct ntb_transport_qp,
 951                                                    link_work.work);
 952         struct pci_dev *pdev = qp->ndev->pdev;
 953         struct ntb_transport_ctx *nt = qp->transport;
 954         int val;
 955
 956         WARN_ON(!nt->link_is_up);
 957
 958         val = ntb_spad_read(nt->ndev, QP_LINKS);
 959
 960         ntb_peer_spad_write(nt->ndev, QP_LINKS, val | BIT(qp->qp_num));
 961
 962         /* query remote spad for qp ready bits */
 963         ntb_peer_spad_read(nt->ndev, QP_LINKS);
 964         dev_dbg_ratelimited(&pdev->dev, "Remote QP link status = %x\n", val);
 965
 966         /* See if the remote side is up */
 967         if (val & BIT(qp->qp_num)) {
 968                 dev_info(&pdev->dev, "qp %d: Link Up\n", qp->qp_num);
 969                 qp->link_is_up = true;
 970                 qp->active = true;
 971
 972                 if (qp->event_handler)
 973                         qp->event_handler(qp->cb_data, qp->link_is_up);
 974
 975                 if (qp->active)
 976                         tasklet_schedule(&qp->rxc_db_work);
 977         } else if (nt->link_is_up)
 978                 schedule_delayed_work(&qp->link_work,
 979                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 980 }
 981
 982 static int ntb_transport_init_queue(struct ntb_transport_ctx *nt,
 983                                     unsigned int qp_num)
 984 {
 985         struct ntb_transport_qp *qp;
 986         phys_addr_t mw_base;
 987         resource_size_t mw_size;
 988         unsigned int num_qps_mw, tx_size;
 989         unsigned int mw_num, mw_count, qp_count;
 990         u64 qp_offset;
 991
 992         mw_count = nt->mw_count;
 993         qp_count = nt->qp_count;
 994
 995         mw_num = QP_TO_MW(nt, qp_num);
 996
 997         qp = &nt->qp_vec[qp_num];
 998         qp->qp_num = qp_num;
 999         qp->transport = nt;
1000         qp->ndev = nt->ndev;
1001         qp->client_ready = false;
1002         qp->event_handler = NULL;
1003         ntb_qp_link_down_reset(qp);
1004
1005         if (qp_count % mw_count && mw_num + 1 < qp_count / mw_count)
1006                 num_qps_mw = qp_count / mw_count + 1;
1007         else
1008                 num_qps_mw = qp_count / mw_count;
1009
1010         mw_base = nt->mw_vec[mw_num].phys_addr;
1011         mw_size = nt->mw_vec[mw_num].phys_size;
1012
1013         tx_size = (unsigned int)mw_size / num_qps_mw;
1014         qp_offset = tx_size * (qp_num / mw_count);
1015
1016         qp->tx_mw = nt->mw_vec[mw_num].vbase + qp_offset;
1017         if (!qp->tx_mw)
1018                 return -EINVAL;
1019
1020         qp->tx_mw_phys = mw_base + qp_offset;
1021         if (!qp->tx_mw_phys)
1022                 return -EINVAL;
1023
1024         tx_size -= sizeof(struct ntb_rx_info);
1025         qp->rx_info = qp->tx_mw + tx_size;
1026
1027         /* Due to housekeeping, there must be atleast 2 buffs */
1028         qp->tx_max_frame = min(transport_mtu, tx_size / 2);
1029         qp->tx_max_entry = tx_size / qp->tx_max_frame;
1030
1031         if (nt->debugfs_node_dir) {
1032                 char debugfs_name[4];
1033
1034                 snprintf(debugfs_name, 4, "qp%d", qp_num);
1035                 qp->debugfs_dir = debugfs_create_dir(debugfs_name,
1036                                                      nt->debugfs_node_dir);
1037
1038                 qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR,
1039                                                         qp->debugfs_dir, qp,
1040                                                         &ntb_qp_debugfs_stats);
1041         } else {
1042                 qp->debugfs_dir = NULL;
1043                 qp->debugfs_stats = NULL;
1044         }
1045
1046         INIT_DELAYED_WORK(&qp->link_work, ntb_qp_link_work);
1047         INIT_WORK(&qp->link_cleanup, ntb_qp_link_cleanup_work);
1048
1049         spin_lock_init(&qp->ntb_rx_q_lock);
1050         spin_lock_init(&qp->ntb_tx_free_q_lock);
1051
1052         INIT_LIST_HEAD(&qp->rx_post_q);
1053         INIT_LIST_HEAD(&qp->rx_pend_q);
1054         INIT_LIST_HEAD(&qp->rx_free_q);
1055         INIT_LIST_HEAD(&qp->tx_free_q);
1056
1057         tasklet_init(&qp->rxc_db_work, ntb_transport_rxc_db,
1058                      (unsigned long)qp);
1059
1060         return 0;
1061 }
1062
1063 static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev)
1064 {
1065         struct ntb_transport_ctx *nt;
1066         struct ntb_transport_mw *mw;
1067         unsigned int mw_count, qp_count;
1068         u64 qp_bitmap;
1069         int node;
1070         int rc, i;
1071
1072         mw_count = ntb_mw_count(ndev);
1073         if (ntb_spad_count(ndev) < (NUM_MWS + 1 + mw_count * 2)) {
1074                 dev_err(&ndev->dev, "Not enough scratch pad registers for %s",
1075                         NTB_TRANSPORT_NAME);
1076                 return -EIO;
1077         }
1078
1079         if (ntb_db_is_unsafe(ndev))
1080                 dev_dbg(&ndev->dev,
1081                         "doorbell is unsafe, proceed anyway...\n");
1082         if (ntb_spad_is_unsafe(ndev))
1083                 dev_dbg(&ndev->dev,
1084                         "scratchpad is unsafe, proceed anyway...\n");
1085
1086         node = dev_to_node(&ndev->dev);
1087
1088         nt = kzalloc_node(sizeof(*nt), GFP_KERNEL, node);
1089         if (!nt)
1090                 return -ENOMEM;
1091
1092         nt->ndev = ndev;
1093
1094         nt->mw_count = mw_count;
1095
1096         nt->mw_vec = kzalloc_node(mw_count * sizeof(*nt->mw_vec),
1097                                   GFP_KERNEL, node);
1098         if (!nt->mw_vec) {
1099                 rc = -ENOMEM;
1100                 goto err;
1101         }
1102
1103         for (i = 0; i < mw_count; i++) {
1104                 mw = &nt->mw_vec[i];
1105
1106                 rc = ntb_mw_get_range(ndev, i, &mw->phys_addr, &mw->phys_size,
1107                                       &mw->xlat_align, &mw->xlat_align_size);
1108                 if (rc)
1109                         goto err1;
1110
1111                 mw->vbase = ioremap_wc(mw->phys_addr, mw->phys_size);
1112                 if (!mw->vbase) {
1113                         rc = -ENOMEM;
1114                         goto err1;
1115                 }
1116
1117                 mw->buff_size = 0;
1118                 mw->xlat_size = 0;
1119                 mw->virt_addr = NULL;
1120                 mw->dma_addr = 0;
1121         }
1122
1123         qp_bitmap = ntb_db_valid_mask(ndev);
1124
1125         qp_count = ilog2(qp_bitmap);
1126         if (max_num_clients && max_num_clients < qp_count)
1127                 qp_count = max_num_clients;
1128         else if (mw_count < qp_count)
1129                 qp_count = mw_count;
1130
1131         qp_bitmap &= BIT_ULL(qp_count) - 1;
1132
1133         nt->qp_count = qp_count;
1134         nt->qp_bitmap = qp_bitmap;
1135         nt->qp_bitmap_free = qp_bitmap;
1136
1137         nt->qp_vec = kzalloc_node(qp_count * sizeof(*nt->qp_vec),
1138                                   GFP_KERNEL, node);
1139         if (!nt->qp_vec) {
1140                 rc = -ENOMEM;
1141                 goto err1;
1142         }
1143
1144         if (nt_debugfs_dir) {
1145                 nt->debugfs_node_dir =
1146                         debugfs_create_dir(pci_name(ndev->pdev),
1147                                            nt_debugfs_dir);
1148         }
1149
1150         for (i = 0; i < qp_count; i++) {
1151                 rc = ntb_transport_init_queue(nt, i);
1152                 if (rc)
1153                         goto err2;
1154         }
1155
1156         INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work);
1157         INIT_WORK(&nt->link_cleanup, ntb_transport_link_cleanup_work);
1158
1159         rc = ntb_set_ctx(ndev, nt, &ntb_transport_ops);
1160         if (rc)
1161                 goto err2;
1162
1163         INIT_LIST_HEAD(&nt->client_devs);
1164         rc = ntb_bus_init(nt);
1165         if (rc)
1166                 goto err3;
1167
1168         nt->link_is_up = false;
1169         ntb_link_enable(ndev, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
1170         ntb_link_event(ndev);
1171
1172         return 0;
1173
1174 err3:
1175         ntb_clear_ctx(ndev);
1176 err2:
1177         kfree(nt->qp_vec);
1178 err1:
1179         while (i--) {
1180                 mw = &nt->mw_vec[i];
1181                 iounmap(mw->vbase);
1182         }
1183         kfree(nt->mw_vec);
1184 err:
1185         kfree(nt);
1186         return rc;
1187 }
1188
1189 static void ntb_transport_free(struct ntb_client *self, struct ntb_dev *ndev)
1190 {
1191         struct ntb_transport_ctx *nt = ndev->ctx;
1192         struct ntb_transport_qp *qp;
1193         u64 qp_bitmap_alloc;
1194         int i;
1195
1196         ntb_transport_link_cleanup(nt);
1197         cancel_work_sync(&nt->link_cleanup);
1198         cancel_delayed_work_sync(&nt->link_work);
1199
1200         qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
1201
1202         /* verify that all the qp's are freed */
1203         for (i = 0; i < nt->qp_count; i++) {
1204                 qp = &nt->qp_vec[i];
1205                 if (qp_bitmap_alloc & BIT_ULL(i))
1206                         ntb_transport_free_queue(qp);
1207                 debugfs_remove_recursive(qp->debugfs_dir);
1208         }
1209
1210         ntb_link_disable(ndev);
1211         ntb_clear_ctx(ndev);
1212
1213         ntb_bus_remove(nt);
1214
1215         for (i = nt->mw_count; i--; ) {
1216                 ntb_free_mw(nt, i);
1217                 iounmap(nt->mw_vec[i].vbase);
1218         }
1219
1220         kfree(nt->qp_vec);
1221         kfree(nt->mw_vec);
1222         kfree(nt);
1223 }
1224
1225 static void ntb_complete_rxc(struct ntb_transport_qp *qp)
1226 {
1227         struct ntb_queue_entry *entry;
1228         void *cb_data;
1229         unsigned int len;
1230         unsigned long irqflags;
1231
1232         spin_lock_irqsave(&qp->ntb_rx_q_lock, irqflags);
1233
1234         while (!list_empty(&qp->rx_post_q)) {
1235                 entry = list_first_entry(&qp->rx_post_q,
1236                                          struct ntb_queue_entry, entry);
1237                 if (!(entry->flags & DESC_DONE_FLAG))
1238                         break;
1239
1240                 entry->rx_hdr->flags = 0;
1241                 iowrite32(entry->rx_index, &qp->rx_info->entry);
1242
1243                 cb_data = entry->cb_data;
1244                 len = entry->len;
1245
1246                 list_move_tail(&entry->entry, &qp->rx_free_q);
1247
1248                 spin_unlock_irqrestore(&qp->ntb_rx_q_lock, irqflags);
1249
1250                 if (qp->rx_handler && qp->client_ready)
1251                         qp->rx_handler(qp, qp->cb_data, cb_data, len);
1252
1253                 spin_lock_irqsave(&qp->ntb_rx_q_lock, irqflags);
1254         }
1255
1256         spin_unlock_irqrestore(&qp->ntb_rx_q_lock, irqflags);
1257 }
1258
1259 static void ntb_rx_copy_callback(void *data,
1260                                  const struct dmaengine_result *res)
1261 {
1262         struct ntb_queue_entry *entry = data;
1263
1264         /* we need to check DMA results if we are using DMA */
1265         if (res) {
1266                 enum dmaengine_tx_result dma_err = res->result;
1267
1268                 switch (dma_err) {
1269                 case DMA_TRANS_READ_FAILED:
1270                 case DMA_TRANS_WRITE_FAILED:
1271                         entry->errors++;
1272                 case DMA_TRANS_ABORTED:
1273                 {
1274                         struct ntb_transport_qp *qp = entry->qp;
1275                         void *offset = qp->rx_buff + qp->rx_max_frame *
1276                                         qp->rx_index;
1277
1278                         ntb_memcpy_rx(entry, offset);
1279                         qp->rx_memcpy++;
1280                         return;
1281                 }
1282
1283                 case DMA_TRANS_NOERROR:
1284                 default:
1285                         break;
1286                 }
1287         }
1288
1289         entry->flags |= DESC_DONE_FLAG;
1290
1291         ntb_complete_rxc(entry->qp);
1292 }
1293
1294 static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void *offset)
1295 {
1296         void *buf = entry->buf;
1297         size_t len = entry->len;
1298
1299         memcpy(buf, offset, len);
1300
1301         /* Ensure that the data is fully copied out before clearing the flag */
1302         wmb();
1303
1304         ntb_rx_copy_callback(entry, NULL);
1305 }
1306
1307 static int ntb_async_rx_submit(struct ntb_queue_entry *entry, void *offset)
1308 {
1309         struct dma_async_tx_descriptor *txd;
1310         struct ntb_transport_qp *qp = entry->qp;
1311         struct dma_chan *chan = qp->rx_dma_chan;
1312         struct dma_device *device;
1313         size_t pay_off, buff_off, len;
1314         struct dmaengine_unmap_data *unmap;
1315         dma_cookie_t cookie;
1316         void *buf = entry->buf;
1317         int retries = 0;
1318
1319         len = entry->len;
1320         device = chan->device;
1321         pay_off = (size_t)offset & ~PAGE_MASK;
1322         buff_off = (size_t)buf & ~PAGE_MASK;
1323
1324         if (!is_dma_copy_aligned(device, pay_off, buff_off, len))
1325                 goto err;
1326
1327         unmap = dmaengine_get_unmap_data(device->dev, 2, GFP_NOWAIT);
1328         if (!unmap)
1329                 goto err;
1330
1331         unmap->len = len;
1332         unmap->addr[0] = dma_map_page(device->dev, virt_to_page(offset),
1333                                       pay_off, len, DMA_TO_DEVICE);
1334         if (dma_mapping_error(device->dev, unmap->addr[0]))
1335                 goto err_get_unmap;
1336
1337         unmap->to_cnt = 1;
1338
1339         unmap->addr[1] = dma_map_page(device->dev, virt_to_page(buf),
1340                                       buff_off, len, DMA_FROM_DEVICE);
1341         if (dma_mapping_error(device->dev, unmap->addr[1]))
1342                 goto err_get_unmap;
1343
1344         unmap->from_cnt = 1;
1345
1346         for (retries = 0; retries < DMA_RETRIES; retries++) {
1347                 txd = device->device_prep_dma_memcpy(chan,
1348                                                      unmap->addr[1],
1349                                                      unmap->addr[0], len,
1350                                                      DMA_PREP_INTERRUPT);
1351                 if (txd)
1352                         break;
1353
1354                 set_current_state(TASK_INTERRUPTIBLE);
1355                 schedule_timeout(DMA_OUT_RESOURCE_TO);
1356         }
1357
1358         if (!txd) {
1359                 qp->dma_rx_prep_err++;
1360                 goto err_get_unmap;
1361         }
1362
1363         txd->callback_result = ntb_rx_copy_callback;
1364         txd->callback_param = entry;
1365         dma_set_unmap(txd, unmap);
1366
1367         cookie = dmaengine_submit(txd);
1368         if (dma_submit_error(cookie))
1369                 goto err_set_unmap;
1370
1371         dmaengine_unmap_put(unmap);
1372
1373         qp->last_cookie = cookie;
1374
1375         qp->rx_async++;
1376
1377         return 0;
1378
1379 err_set_unmap:
1380         dmaengine_unmap_put(unmap);
1381 err_get_unmap:
1382         dmaengine_unmap_put(unmap);
1383 err:
1384         return -ENXIO;
1385 }
1386
1387 static void ntb_async_rx(struct ntb_queue_entry *entry, void *offset)
1388 {
1389         struct ntb_transport_qp *qp = entry->qp;
1390         struct dma_chan *chan = qp->rx_dma_chan;
1391         int res;
1392
1393         if (!chan)
1394                 goto err;
1395
1396         if (entry->len < copy_bytes)
1397                 goto err;
1398
1399         res = ntb_async_rx_submit(entry, offset);
1400         if (res < 0)
1401                 goto err;
1402
1403         if (!entry->retries)
1404                 qp->rx_async++;
1405
1406         return;
1407
1408 err:
1409         ntb_memcpy_rx(entry, offset);
1410         qp->rx_memcpy++;
1411 }
1412
1413 static int ntb_process_rxc(struct ntb_transport_qp *qp)
1414 {
1415         struct ntb_payload_header *hdr;
1416         struct ntb_queue_entry *entry;
1417         void *offset;
1418
1419         offset = qp->rx_buff + qp->rx_max_frame * qp->rx_index;
1420         hdr = offset + qp->rx_max_frame - sizeof(struct ntb_payload_header);
1421
1422         dev_dbg(&qp->ndev->pdev->dev, "qp %d: RX ver %u len %d flags %x\n",
1423                 qp->qp_num, hdr->ver, hdr->len, hdr->flags);
1424
1425         if (!(hdr->flags & DESC_DONE_FLAG)) {
1426                 dev_dbg(&qp->ndev->pdev->dev, "done flag not set\n");
1427                 qp->rx_ring_empty++;
1428                 return -EAGAIN;
1429         }
1430
1431         if (hdr->flags & LINK_DOWN_FLAG) {
1432                 dev_dbg(&qp->ndev->pdev->dev, "link down flag set\n");
1433                 ntb_qp_link_down(qp);
1434                 hdr->flags = 0;
1435                 return -EAGAIN;
1436         }
1437
1438         if (hdr->ver != (u32)qp->rx_pkts) {
1439                 dev_dbg(&qp->ndev->pdev->dev,
1440                         "version mismatch, expected %llu - got %u\n",
1441                         qp->rx_pkts, hdr->ver);
1442                 qp->rx_err_ver++;
1443                 return -EIO;
1444         }
1445
1446         entry = ntb_list_mv(&qp->ntb_rx_q_lock, &qp->rx_pend_q, &qp->rx_post_q);
1447         if (!entry) {
1448                 dev_dbg(&qp->ndev->pdev->dev, "no receive buffer\n");
1449                 qp->rx_err_no_buf++;
1450                 return -EAGAIN;
1451         }
1452
1453         entry->rx_hdr = hdr;
1454         entry->rx_index = qp->rx_index;
1455
1456         if (hdr->len > entry->len) {
1457                 dev_dbg(&qp->ndev->pdev->dev,
1458                         "receive buffer overflow! Wanted %d got %d\n",
1459                         hdr->len, entry->len);
1460                 qp->rx_err_oflow++;
1461
1462                 entry->len = -EIO;
1463                 entry->flags |= DESC_DONE_FLAG;
1464
1465                 ntb_complete_rxc(qp);
1466         } else {
1467                 dev_dbg(&qp->ndev->pdev->dev,
1468                         "RX OK index %u ver %u size %d into buf size %d\n",
1469                         qp->rx_index, hdr->ver, hdr->len, entry->len);
1470
1471                 qp->rx_bytes += hdr->len;
1472                 qp->rx_pkts++;
1473
1474                 entry->len = hdr->len;
1475
1476                 ntb_async_rx(entry, offset);
1477         }
1478
1479         qp->rx_index++;
1480         qp->rx_index %= qp->rx_max_entry;
1481
1482         return 0;
1483 }
1484
1485 static void ntb_transport_rxc_db(unsigned long data)
1486 {
1487         struct ntb_transport_qp *qp = (void *)data;
1488         int rc, i;
1489
1490         dev_dbg(&qp->ndev->pdev->dev, "%s: doorbell %d received\n",
1491                 __func__, qp->qp_num);
1492
1493         /* Limit the number of packets processed in a single interrupt to
1494          * provide fairness to others
1495          */
1496         for (i = 0; i < qp->rx_max_entry; i++) {
1497                 rc = ntb_process_rxc(qp);
1498                 if (rc)
1499                         break;
1500         }
1501
1502         if (i && qp->rx_dma_chan)
1503                 dma_async_issue_pending(qp->rx_dma_chan);
1504
1505         if (i == qp->rx_max_entry) {
1506                 /* there is more work to do */
1507                 if (qp->active)
1508                         tasklet_schedule(&qp->rxc_db_work);
1509         } else if (ntb_db_read(qp->ndev) & BIT_ULL(qp->qp_num)) {
1510                 /* the doorbell bit is set: clear it */
1511                 ntb_db_clear(qp->ndev, BIT_ULL(qp->qp_num));
1512                 /* ntb_db_read ensures ntb_db_clear write is committed */
1513                 ntb_db_read(qp->ndev);
1514
1515                 /* an interrupt may have arrived between finishing
1516                  * ntb_process_rxc and clearing the doorbell bit:
1517                  * there might be some more work to do.
1518                  */
1519                 if (qp->active)
1520                         tasklet_schedule(&qp->rxc_db_work);
1521         }
1522 }
1523
1524 static void ntb_tx_copy_callback(void *data,
1525                                  const struct dmaengine_result *res)
1526 {
1527         struct ntb_queue_entry *entry = data;
1528         struct ntb_transport_qp *qp = entry->qp;
1529         struct ntb_payload_header __iomem *hdr = entry->tx_hdr;
1530
1531         /* we need to check DMA results if we are using DMA */
1532         if (res) {
1533                 enum dmaengine_tx_result dma_err = res->result;
1534
1535                 switch (dma_err) {
1536                 case DMA_TRANS_READ_FAILED:
1537                 case DMA_TRANS_WRITE_FAILED:
1538                         entry->errors++;
1539                 case DMA_TRANS_ABORTED:
1540                 {
1541                         void __iomem *offset =
1542                                 qp->tx_mw + qp->tx_max_frame *
1543                                 entry->tx_index;
1544
1545                         /* resubmit via CPU */
1546                         ntb_memcpy_tx(entry, offset);
1547                         qp->tx_memcpy++;
1548                         return;
1549                 }
1550
1551                 case DMA_TRANS_NOERROR:
1552                 default:
1553                         break;
1554                 }
1555         }
1556
1557         iowrite32(entry->flags | DESC_DONE_FLAG, &hdr->flags);
1558
1559         ntb_peer_db_set(qp->ndev, BIT_ULL(qp->qp_num));
1560
1561         /* The entry length can only be zero if the packet is intended to be a
1562          * "link down" or similar.  Since no payload is being sent in these
1563          * cases, there is nothing to add to the completion queue.
1564          */
1565         if (entry->len > 0) {
1566                 qp->tx_bytes += entry->len;
1567
1568                 if (qp->tx_handler)
1569                         qp->tx_handler(qp, qp->cb_data, entry->cb_data,
1570                                        entry->len);
1571         }
1572
1573         ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q);
1574 }
1575
1576 static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset)
1577 {
1578 #ifdef ARCH_HAS_NOCACHE_UACCESS
1579         /*
1580          * Using non-temporal mov to improve performance on non-cached
1581          * writes, even though we aren't actually copying from user space.
1582          */
1583         __copy_from_user_inatomic_nocache(offset, entry->buf, entry->len);
1584 #else
1585         memcpy_toio(offset, entry->buf, entry->len);
1586 #endif
1587
1588         /* Ensure that the data is fully copied out before setting the flags */
1589         wmb();
1590
1591         ntb_tx_copy_callback(entry, NULL);
1592 }
1593
1594 static int ntb_async_tx_submit(struct ntb_transport_qp *qp,
1595                                struct ntb_queue_entry *entry)
1596 {
1597         struct dma_async_tx_descriptor *txd;
1598         struct dma_chan *chan = qp->tx_dma_chan;
1599         struct dma_device *device;
1600         size_t len = entry->len;
1601         void *buf = entry->buf;
1602         size_t dest_off, buff_off;
1603         struct dmaengine_unmap_data *unmap;
1604         dma_addr_t dest;
1605         dma_cookie_t cookie;
1606         int retries = 0;
1607
1608         device = chan->device;
1609         dest = qp->tx_mw_phys + qp->tx_max_frame * entry->tx_index;
1610         buff_off = (size_t)buf & ~PAGE_MASK;
1611         dest_off = (size_t)dest & ~PAGE_MASK;
1612
1613         if (!is_dma_copy_aligned(device, buff_off, dest_off, len))
1614                 goto err;
1615
1616         unmap = dmaengine_get_unmap_data(device->dev, 1, GFP_NOWAIT);
1617         if (!unmap)
1618                 goto err;
1619
1620         unmap->len = len;
1621         unmap->addr[0] = dma_map_page(device->dev, virt_to_page(buf),
1622                                       buff_off, len, DMA_TO_DEVICE);
1623         if (dma_mapping_error(device->dev, unmap->addr[0]))
1624                 goto err_get_unmap;
1625
1626         unmap->to_cnt = 1;
1627
1628         for (retries = 0; retries < DMA_RETRIES; retries++) {
1629                 txd = device->device_prep_dma_memcpy(chan, dest,
1630                                                      unmap->addr[0], len,
1631                                                      DMA_PREP_INTERRUPT);
1632                 if (txd)
1633                         break;
1634
1635                 set_current_state(TASK_INTERRUPTIBLE);
1636                 schedule_timeout(DMA_OUT_RESOURCE_TO);
1637         }
1638
1639         if (!txd) {
1640                 qp->dma_tx_prep_err++;
1641                 goto err_get_unmap;
1642         }
1643
1644         txd->callback_result = ntb_tx_copy_callback;
1645         txd->callback_param = entry;
1646         dma_set_unmap(txd, unmap);
1647
1648         cookie = dmaengine_submit(txd);
1649         if (dma_submit_error(cookie))
1650                 goto err_set_unmap;
1651
1652         dmaengine_unmap_put(unmap);
1653
1654         dma_async_issue_pending(chan);
1655
1656         return 0;
1657 err_set_unmap:
1658         dmaengine_unmap_put(unmap);
1659 err_get_unmap:
1660         dmaengine_unmap_put(unmap);
1661 err:
1662         return -ENXIO;
1663 }
1664
1665 static void ntb_async_tx(struct ntb_transport_qp *qp,
1666                          struct ntb_queue_entry *entry)
1667 {
1668         struct ntb_payload_header __iomem *hdr;
1669         struct dma_chan *chan = qp->tx_dma_chan;
1670         void __iomem *offset;
1671         int res;
1672
1673         entry->tx_index = qp->tx_index;
1674         offset = qp->tx_mw + qp->tx_max_frame * entry->tx_index;
1675         hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
1676         entry->tx_hdr = hdr;
1677
1678         iowrite32(entry->len, &hdr->len);
1679         iowrite32((u32)qp->tx_pkts, &hdr->ver);
1680
1681         if (!chan)
1682                 goto err;
1683
1684         if (entry->len < copy_bytes)
1685                 goto err;
1686
1687         res = ntb_async_tx_submit(qp, entry);
1688         if (res < 0)
1689                 goto err;
1690
1691         if (!entry->retries)
1692                 qp->tx_async++;
1693
1694         return;
1695
1696 err:
1697         ntb_memcpy_tx(entry, offset);
1698         qp->tx_memcpy++;
1699 }
1700
1701 static int ntb_process_tx(struct ntb_transport_qp *qp,
1702                           struct ntb_queue_entry *entry)
1703 {
1704         if (qp->tx_index == qp->remote_rx_info->entry) {
1705                 qp->tx_ring_full++;
1706                 return -EAGAIN;
1707         }
1708
1709         if (entry->len > qp->tx_max_frame - sizeof(struct ntb_payload_header)) {
1710                 if (qp->tx_handler)
1711                         qp->tx_handler(qp, qp->cb_data, NULL, -EIO);
1712
1713                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1714                              &qp->tx_free_q);
1715                 return 0;
1716         }
1717
1718         ntb_async_tx(qp, entry);
1719
1720         qp->tx_index++;
1721         qp->tx_index %= qp->tx_max_entry;
1722
1723         qp->tx_pkts++;
1724
1725         return 0;
1726 }
1727
1728 static void ntb_send_link_down(struct ntb_transport_qp *qp)
1729 {
1730         struct pci_dev *pdev = qp->ndev->pdev;
1731         struct ntb_queue_entry *entry;
1732         int i, rc;
1733
1734         if (!qp->link_is_up)
1735                 return;
1736
1737         dev_info(&pdev->dev, "qp %d: Send Link Down\n", qp->qp_num);
1738
1739         for (i = 0; i < NTB_LINK_DOWN_TIMEOUT; i++) {
1740                 entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1741                 if (entry)
1742                         break;
1743                 msleep(100);
1744         }
1745
1746         if (!entry)
1747                 return;
1748
1749         entry->cb_data = NULL;
1750         entry->buf = NULL;
1751         entry->len = 0;
1752         entry->flags = LINK_DOWN_FLAG;
1753
1754         rc = ntb_process_tx(qp, entry);
1755         if (rc)
1756                 dev_err(&pdev->dev, "ntb: QP%d unable to send linkdown msg\n",
1757                         qp->qp_num);
1758
1759         ntb_qp_link_down_reset(qp);
1760 }
1761
1762 static bool ntb_dma_filter_fn(struct dma_chan *chan, void *node)
1763 {
1764         return dev_to_node(&chan->dev->device) == (int)(unsigned long)node;
1765 }
1766
1767 /**
1768  * ntb_transport_create_queue - Create a new NTB transport layer queue
1769  * @rx_handler: receive callback function
1770  * @tx_handler: transmit callback function
1771  * @event_handler: event callback function
1772  *
1773  * Create a new NTB transport layer queue and provide the queue with a callback
1774  * routine for both transmit and receive.  The receive callback routine will be
1775  * used to pass up data when the transport has received it on the queue.   The
1776  * transmit callback routine will be called when the transport has completed the
1777  * transmission of the data on the queue and the data is ready to be freed.
1778  *
1779  * RETURNS: pointer to newly created ntb_queue, NULL on error.
1780  */
1781 struct ntb_transport_qp *
1782 ntb_transport_create_queue(void *data, struct device *client_dev,
1783                            const struct ntb_queue_handlers *handlers)
1784 {
1785         struct ntb_dev *ndev;
1786         struct pci_dev *pdev;
1787         struct ntb_transport_ctx *nt;
1788         struct ntb_queue_entry *entry;
1789         struct ntb_transport_qp *qp;
1790         u64 qp_bit;
1791         unsigned int free_queue;
1792         dma_cap_mask_t dma_mask;
1793         int node;
1794         int i;
1795
1796         ndev = dev_ntb(client_dev->parent);
1797         pdev = ndev->pdev;
1798         nt = ndev->ctx;
1799
1800         node = dev_to_node(&ndev->dev);
1801
1802         free_queue = ffs(nt->qp_bitmap);
1803         if (!free_queue)
1804                 goto err;
1805
1806         /* decrement free_queue to make it zero based */
1807         free_queue--;
1808
1809         qp = &nt->qp_vec[free_queue];
1810         qp_bit = BIT_ULL(qp->qp_num);
1811
1812         nt->qp_bitmap_free &= ~qp_bit;
1813
1814         qp->cb_data = data;
1815         qp->rx_handler = handlers->rx_handler;
1816         qp->tx_handler = handlers->tx_handler;
1817         qp->event_handler = handlers->event_handler;
1818
1819         dma_cap_zero(dma_mask);
1820         dma_cap_set(DMA_MEMCPY, dma_mask);
1821
1822         if (use_dma) {
1823                 qp->tx_dma_chan =
1824                         dma_request_channel(dma_mask, ntb_dma_filter_fn,
1825                                             (void *)(unsigned long)node);
1826                 if (!qp->tx_dma_chan)
1827                         dev_info(&pdev->dev, "Unable to allocate TX DMA channel\n");
1828
1829                 qp->rx_dma_chan =
1830                         dma_request_channel(dma_mask, ntb_dma_filter_fn,
1831                                             (void *)(unsigned long)node);
1832                 if (!qp->rx_dma_chan)
1833                         dev_info(&pdev->dev, "Unable to allocate RX DMA channel\n");
1834         } else {
1835                 qp->tx_dma_chan = NULL;
1836                 qp->rx_dma_chan = NULL;
1837         }
1838
1839         dev_dbg(&pdev->dev, "Using %s memcpy for TX\n",
1840                 qp->tx_dma_chan ? "DMA" : "CPU");
1841
1842         dev_dbg(&pdev->dev, "Using %s memcpy for RX\n",
1843                 qp->rx_dma_chan ? "DMA" : "CPU");
1844
1845         for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
1846                 entry = kzalloc_node(sizeof(*entry), GFP_ATOMIC, node);
1847                 if (!entry)
1848                         goto err1;
1849
1850                 entry->qp = qp;
1851                 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry,
1852                              &qp->rx_free_q);
1853         }
1854         qp->rx_alloc_entry = NTB_QP_DEF_NUM_ENTRIES;
1855
1856         for (i = 0; i < qp->tx_max_entry; i++) {
1857                 entry = kzalloc_node(sizeof(*entry), GFP_ATOMIC, node);
1858                 if (!entry)
1859                         goto err2;
1860
1861                 entry->qp = qp;
1862                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1863                              &qp->tx_free_q);
1864         }
1865
1866         ntb_db_clear(qp->ndev, qp_bit);
1867         ntb_db_clear_mask(qp->ndev, qp_bit);
1868
1869         dev_info(&pdev->dev, "NTB Transport QP %d created\n", qp->qp_num);
1870
1871         return qp;
1872
1873 err2:
1874         while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1875                 kfree(entry);
1876 err1:
1877         qp->rx_alloc_entry = 0;
1878         while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
1879                 kfree(entry);
1880         if (qp->tx_dma_chan)
1881                 dma_release_channel(qp->tx_dma_chan);
1882         if (qp->rx_dma_chan)
1883                 dma_release_channel(qp->rx_dma_chan);
1884         nt->qp_bitmap_free |= qp_bit;
1885 err:
1886         return NULL;
1887 }
1888 EXPORT_SYMBOL_GPL(ntb_transport_create_queue);
1889
1890 /**
1891  * ntb_transport_free_queue - Frees NTB transport queue
1892  * @qp: NTB queue to be freed
1893  *
1894  * Frees NTB transport queue
1895  */
1896 void ntb_transport_free_queue(struct ntb_transport_qp *qp)
1897 {
1898         struct pci_dev *pdev;
1899         struct ntb_queue_entry *entry;
1900         u64 qp_bit;
1901
1902         if (!qp)
1903                 return;
1904
1905         pdev = qp->ndev->pdev;
1906
1907         qp->active = false;
1908
1909         if (qp->tx_dma_chan) {
1910                 struct dma_chan *chan = qp->tx_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->tx_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         if (qp->rx_dma_chan) {
1925                 struct dma_chan *chan = qp->rx_dma_chan;
1926                 /* Putting the dma_chan to NULL will force any new traffic to be
1927                  * processed by the CPU instead of the DAM engine
1928                  */
1929                 qp->rx_dma_chan = NULL;
1930
1931                 /* Try to be nice and wait for any queued DMA engine
1932                  * transactions to process before smashing it with a rock
1933                  */
1934                 dma_sync_wait(chan, qp->last_cookie);
1935                 dmaengine_terminate_all(chan);
1936                 dma_release_channel(chan);
1937         }
1938
1939         qp_bit = BIT_ULL(qp->qp_num);
1940
1941         ntb_db_set_mask(qp->ndev, qp_bit);
1942         tasklet_kill(&qp->rxc_db_work);
1943
1944         cancel_delayed_work_sync(&qp->link_work);
1945
1946         qp->cb_data = NULL;
1947         qp->rx_handler = NULL;
1948         qp->tx_handler = NULL;
1949         qp->event_handler = NULL;
1950
1951         while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
1952                 kfree(entry);
1953
1954         while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_pend_q))) {
1955                 dev_warn(&pdev->dev, "Freeing item from non-empty rx_pend_q\n");
1956                 kfree(entry);
1957         }
1958
1959         while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_post_q))) {
1960                 dev_warn(&pdev->dev, "Freeing item from non-empty rx_post_q\n");
1961                 kfree(entry);
1962         }
1963
1964         while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1965                 kfree(entry);
1966
1967         qp->transport->qp_bitmap_free |= qp_bit;
1968
1969         dev_info(&pdev->dev, "NTB Transport QP %d freed\n", qp->qp_num);
1970 }
1971 EXPORT_SYMBOL_GPL(ntb_transport_free_queue);
1972
1973 /**
1974  * ntb_transport_rx_remove - Dequeues enqueued rx packet
1975  * @qp: NTB queue to be freed
1976  * @len: pointer to variable to write enqueued buffers length
1977  *
1978  * Dequeues unused buffers from receive queue.  Should only be used during
1979  * shutdown of qp.
1980  *
1981  * RETURNS: NULL error value on error, or void* for success.
1982  */
1983 void *ntb_transport_rx_remove(struct ntb_transport_qp *qp, unsigned int *len)
1984 {
1985         struct ntb_queue_entry *entry;
1986         void *buf;
1987
1988         if (!qp || qp->client_ready)
1989                 return NULL;
1990
1991         entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_pend_q);
1992         if (!entry)
1993                 return NULL;
1994
1995         buf = entry->cb_data;
1996         *len = entry->len;
1997
1998         ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_free_q);
1999
2000         return buf;
2001 }
2002 EXPORT_SYMBOL_GPL(ntb_transport_rx_remove);
2003
2004 /**
2005  * ntb_transport_rx_enqueue - Enqueue a new NTB queue entry
2006  * @qp: NTB transport layer queue the entry is to be enqueued on
2007  * @cb: per buffer pointer for callback function to use
2008  * @data: pointer to data buffer that incoming packets will be copied into
2009  * @len: length of the data buffer
2010  *
2011  * Enqueue a new receive buffer onto the transport queue into which a NTB
2012  * payload can be received into.
2013  *
2014  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
2015  */
2016 int ntb_transport_rx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
2017                              unsigned int len)
2018 {
2019         struct ntb_queue_entry *entry;
2020
2021         if (!qp)
2022                 return -EINVAL;
2023
2024         entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q);
2025         if (!entry)
2026                 return -ENOMEM;
2027
2028         entry->cb_data = cb;
2029         entry->buf = data;
2030         entry->len = len;
2031         entry->flags = 0;
2032         entry->retries = 0;
2033         entry->errors = 0;
2034         entry->rx_index = 0;
2035
2036         ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_pend_q);
2037
2038         if (qp->active)
2039                 tasklet_schedule(&qp->rxc_db_work);
2040
2041         return 0;
2042 }
2043 EXPORT_SYMBOL_GPL(ntb_transport_rx_enqueue);
2044
2045 /**
2046  * ntb_transport_tx_enqueue - Enqueue a new NTB queue entry
2047  * @qp: NTB transport layer queue the entry is to be enqueued on
2048  * @cb: per buffer pointer for callback function to use
2049  * @data: pointer to data buffer that will be sent
2050  * @len: length of the data buffer
2051  *
2052  * Enqueue a new transmit buffer onto the transport queue from which a NTB
2053  * payload will be transmitted.  This assumes that a lock is being held to
2054  * serialize access to the qp.
2055  *
2056  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
2057  */
2058 int ntb_transport_tx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
2059                              unsigned int len)
2060 {
2061         struct ntb_queue_entry *entry;
2062         int rc;
2063
2064         if (!qp || !qp->link_is_up || !len)
2065                 return -EINVAL;
2066
2067         entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
2068         if (!entry) {
2069                 qp->tx_err_no_buf++;
2070                 return -EBUSY;
2071         }
2072
2073         entry->cb_data = cb;
2074         entry->buf = data;
2075         entry->len = len;
2076         entry->flags = 0;
2077         entry->errors = 0;
2078         entry->retries = 0;
2079         entry->tx_index = 0;
2080
2081         rc = ntb_process_tx(qp, entry);
2082         if (rc)
2083                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
2084                              &qp->tx_free_q);
2085
2086         return rc;
2087 }
2088 EXPORT_SYMBOL_GPL(ntb_transport_tx_enqueue);
2089
2090 /**
2091  * ntb_transport_link_up - Notify NTB transport of client readiness to use queue
2092  * @qp: NTB transport layer queue to be enabled
2093  *
2094  * Notify NTB transport layer of client readiness to use queue
2095  */
2096 void ntb_transport_link_up(struct ntb_transport_qp *qp)
2097 {
2098         if (!qp)
2099                 return;
2100
2101         qp->client_ready = true;
2102
2103         if (qp->transport->link_is_up)
2104                 schedule_delayed_work(&qp->link_work, 0);
2105 }
2106 EXPORT_SYMBOL_GPL(ntb_transport_link_up);
2107
2108 /**
2109  * ntb_transport_link_down - Notify NTB transport to no longer enqueue data
2110  * @qp: NTB transport layer queue to be disabled
2111  *
2112  * Notify NTB transport layer of client's desire to no longer receive data on
2113  * transport queue specified.  It is the client's responsibility to ensure all
2114  * entries on queue are purged or otherwise handled appropriately.
2115  */
2116 void ntb_transport_link_down(struct ntb_transport_qp *qp)
2117 {
2118         int val;
2119
2120         if (!qp)
2121                 return;
2122
2123         qp->client_ready = false;
2124
2125         val = ntb_spad_read(qp->ndev, QP_LINKS);
2126
2127         ntb_peer_spad_write(qp->ndev, QP_LINKS,
2128                             val & ~BIT(qp->qp_num));
2129
2130         if (qp->link_is_up)
2131                 ntb_send_link_down(qp);
2132         else
2133                 cancel_delayed_work_sync(&qp->link_work);
2134 }
2135 EXPORT_SYMBOL_GPL(ntb_transport_link_down);
2136
2137 /**
2138  * ntb_transport_link_query - Query transport link state
2139  * @qp: NTB transport layer queue to be queried
2140  *
2141  * Query connectivity to the remote system of the NTB transport queue
2142  *
2143  * RETURNS: true for link up or false for link down
2144  */
2145 bool ntb_transport_link_query(struct ntb_transport_qp *qp)
2146 {
2147         if (!qp)
2148                 return false;
2149
2150         return qp->link_is_up;
2151 }
2152 EXPORT_SYMBOL_GPL(ntb_transport_link_query);
2153
2154 /**
2155  * ntb_transport_qp_num - Query the qp number
2156  * @qp: NTB transport layer queue to be queried
2157  *
2158  * Query qp number of the NTB transport queue
2159  *
2160  * RETURNS: a zero based number specifying the qp number
2161  */
2162 unsigned char ntb_transport_qp_num(struct ntb_transport_qp *qp)
2163 {
2164         if (!qp)
2165                 return 0;
2166
2167         return qp->qp_num;
2168 }
2169 EXPORT_SYMBOL_GPL(ntb_transport_qp_num);
2170
2171 /**
2172  * ntb_transport_max_size - Query the max payload size of a qp
2173  * @qp: NTB transport layer queue to be queried
2174  *
2175  * Query the maximum payload size permissible on the given qp
2176  *
2177  * RETURNS: the max payload size of a qp
2178  */
2179 unsigned int ntb_transport_max_size(struct ntb_transport_qp *qp)
2180 {
2181         unsigned int max_size;
2182         unsigned int copy_align;
2183         struct dma_chan *rx_chan, *tx_chan;
2184
2185         if (!qp)
2186                 return 0;
2187
2188         rx_chan = qp->rx_dma_chan;
2189         tx_chan = qp->tx_dma_chan;
2190
2191         copy_align = max(rx_chan ? rx_chan->device->copy_align : 0,
2192                          tx_chan ? tx_chan->device->copy_align : 0);
2193
2194         /* If DMA engine usage is possible, try to find the max size for that */
2195         max_size = qp->tx_max_frame - sizeof(struct ntb_payload_header);
2196         max_size = round_down(max_size, 1 << copy_align);
2197
2198         return max_size;
2199 }
2200 EXPORT_SYMBOL_GPL(ntb_transport_max_size);
2201
2202 unsigned int ntb_transport_tx_free_entry(struct ntb_transport_qp *qp)
2203 {
2204         unsigned int head = qp->tx_index;
2205         unsigned int tail = qp->remote_rx_info->entry;
2206
2207         return tail > head ? tail - head : qp->tx_max_entry + tail - head;
2208 }
2209 EXPORT_SYMBOL_GPL(ntb_transport_tx_free_entry);
2210
2211 static void ntb_transport_doorbell_callback(void *data, int vector)
2212 {
2213         struct ntb_transport_ctx *nt = data;
2214         struct ntb_transport_qp *qp;
2215         u64 db_bits;
2216         unsigned int qp_num;
2217
2218         db_bits = (nt->qp_bitmap & ~nt->qp_bitmap_free &
2219                    ntb_db_vector_mask(nt->ndev, vector));
2220
2221         while (db_bits) {
2222                 qp_num = __ffs(db_bits);
2223                 qp = &nt->qp_vec[qp_num];
2224
2225                 if (qp->active)
2226                         tasklet_schedule(&qp->rxc_db_work);
2227
2228                 db_bits &= ~BIT_ULL(qp_num);
2229         }
2230 }
2231
2232 static const struct ntb_ctx_ops ntb_transport_ops = {
2233         .link_event = ntb_transport_event_callback,
2234         .db_event = ntb_transport_doorbell_callback,
2235 };
2236
2237 static struct ntb_client ntb_transport_client = {
2238         .ops = {
2239                 .probe = ntb_transport_probe,
2240                 .remove = ntb_transport_free,
2241         },
2242 };
2243
2244 static int __init ntb_transport_init(void)
2245 {
2246         int rc;
2247
2248         pr_info("%s, version %s\n", NTB_TRANSPORT_DESC, NTB_TRANSPORT_VER);
2249
2250         if (debugfs_initialized())
2251                 nt_debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
2252
2253         rc = bus_register(&ntb_transport_bus);
2254         if (rc)
2255                 goto err_bus;
2256
2257         rc = ntb_register_client(&ntb_transport_client);
2258         if (rc)
2259                 goto err_client;
2260
2261         return 0;
2262
2263 err_client:
2264         bus_unregister(&ntb_transport_bus);
2265 err_bus:
2266         debugfs_remove_recursive(nt_debugfs_dir);
2267         return rc;
2268 }
2269 module_init(ntb_transport_init);
2270
2271 static void __exit ntb_transport_exit(void)
2272 {
2273         debugfs_remove_recursive(nt_debugfs_dir);
2274
2275         ntb_unregister_client(&ntb_transport_client);
2276         bus_unregister(&ntb_transport_bus);
2277 }
2278 module_exit(ntb_transport_exit);