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