drivers/ntb/ntb_transport.c

   1 /*
   2  * This file is provided under a dual BSD/GPLv2 license.  When using or
   3  *   redistributing this file, you may do so under either license.
   4  *
   5  *   GPL LICENSE SUMMARY
   6  *
   7  *   Copyright(c) 2012 Intel Corporation. All rights reserved.
   8  *   Copyright (C) 2015 EMC Corporation. All Rights Reserved.
   9  *
  10  *   This program is free software; you can redistribute it and/or modify
  11  *   it under the terms of version 2 of the GNU General Public License as
  12  *   published by the Free Software Foundation.
  13  *
  14  *   BSD LICENSE
  15  *
  16  *   Copyright(c) 2012 Intel Corporation. All rights reserved.
  17  *   Copyright (C) 2015 EMC Corporation. All Rights Reserved.
  18  *
  19  *   Redistribution and use in source and binary forms, with or without
  20  *   modification, are permitted provided that the following conditions
  21  *   are met:
  22  *
  23  *     * Redistributions of source code must retain the above copyright
  24  *       notice, this list of conditions and the following disclaimer.
  25  *     * Redistributions in binary form must reproduce the above copy
  26  *       notice, this list of conditions and the following disclaimer in
  27  *       the documentation and/or other materials provided with the
  28  *       distribution.
  29  *     * Neither the name of Intel Corporation nor the names of its
  30  *       contributors may be used to endorse or promote products derived
  31  *       from this software without specific prior written permission.
  32  *
  33  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  34  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  35  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  36  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  37  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  38  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  39  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  40  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  41  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  42  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  43  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  44  *
  45  * PCIe NTB Transport Linux driver
  46  *
  47  * Contact Information:
  48  * Jon Mason <jon.mason@intel.com>
  49  */
  50 #include <linux/debugfs.h>
  51 #include <linux/delay.h>
  52 #include <linux/dmaengine.h>
  53 #include <linux/dma-mapping.h>
  54 #include <linux/errno.h>
  55 #include <linux/export.h>
  56 #include <linux/interrupt.h>
  57 #include <linux/module.h>
  58 #include <linux/pci.h>
  59 #include <linux/slab.h>
  60 #include <linux/types.h>
  61 #include <linux/uaccess.h>
  62 #include "linux/ntb.h"
  63 #include "linux/ntb_transport.h"
  64
  65 #define NTB_TRANSPORT_VERSION   4
  66 #define NTB_TRANSPORT_VER       "4"
  67 #define NTB_TRANSPORT_NAME      "ntb_transport"
  68 #define NTB_TRANSPORT_DESC      "Software Queue-Pair Transport over NTB"
  69 #define NTB_TRANSPORT_MIN_SPADS (MW0_SZ_HIGH + 2)
  70
  71 MODULE_DESCRIPTION(NTB_TRANSPORT_DESC);
  72 MODULE_VERSION(NTB_TRANSPORT_VER);
  73 MODULE_LICENSE("Dual BSD/GPL");
  74 MODULE_AUTHOR("Intel Corporation");
  75
  76 static unsigned long max_mw_size;
  77 module_param(max_mw_size, ulong, 0644);
  78 MODULE_PARM_DESC(max_mw_size, "Limit size of large memory windows");
  79
  80 static unsigned int transport_mtu = 0x10000;
  81 module_param(transport_mtu, uint, 0644);
  82 MODULE_PARM_DESC(transport_mtu, "Maximum size of NTB transport packets");
  83
  84 static unsigned char max_num_clients;
  85 module_param(max_num_clients, byte, 0644);
  86 MODULE_PARM_DESC(max_num_clients, "Maximum number of NTB transport clients");
  87
  88 static unsigned int copy_bytes = 1024;
  89 module_param(copy_bytes, uint, 0644);
  90 MODULE_PARM_DESC(copy_bytes, "Threshold under which NTB will use the CPU to copy instead of DMA");
  91
  92 static bool use_dma;
  93 module_param(use_dma, bool, 0644);
  94 MODULE_PARM_DESC(use_dma, "Use DMA engine to perform large data copy");
  95
  96 static struct dentry *nt_debugfs_dir;
  97
  98 /* Only two-ports NTB devices are supported */
  99 #define PIDX            NTB_DEF_PEER_IDX
 100
 101 struct ntb_queue_entry {
 102         /* ntb_queue list reference */
 103         struct list_head entry;
 104         /* pointers to data to be transferred */
 105         void *cb_data;
 106         void *buf;
 107         unsigned int len;
 108         unsigned int flags;
 109         int retries;
 110         int errors;
 111         unsigned int tx_index;
 112         unsigned int rx_index;
 113
 114         struct ntb_transport_qp *qp;
 115         union {
 116                 struct ntb_payload_header __iomem *tx_hdr;
 117                 struct ntb_payload_header *rx_hdr;
 118         };
 119 };
 120
 121 struct ntb_rx_info {
 122         unsigned int entry;
 123 };
 124
 125 struct ntb_transport_qp {
 126         struct ntb_transport_ctx *transport;
 127         struct ntb_dev *ndev;
 128         void *cb_data;
 129         struct dma_chan *tx_dma_chan;
 130         struct dma_chan *rx_dma_chan;
 131
 132         bool client_ready;
 133         bool link_is_up;
 134         bool active;
 135
 136         u8 qp_num;      /* Only 64 QP's are allowed.  0-63 */
 137         u64 qp_bit;
 138
 139         struct ntb_rx_info __iomem *rx_info;
 140         struct ntb_rx_info *remote_rx_info;
 141
 142         void (*tx_handler)(struct ntb_transport_qp *qp, void *qp_data,
 143                            void *data, int len);
 144         struct list_head tx_free_q;
 145         spinlock_t ntb_tx_free_q_lock;
 146         void __iomem *tx_mw;
 147         dma_addr_t tx_mw_phys;
 148         unsigned int tx_index;
 149         unsigned int tx_max_entry;
 150         unsigned int tx_max_frame;
 151
 152         void (*rx_handler)(struct ntb_transport_qp *qp, void *qp_data,
 153                            void *data, int len);
 154         struct list_head rx_post_q;
 155         struct list_head rx_pend_q;
 156         struct list_head rx_free_q;
 157         /* ntb_rx_q_lock: synchronize access to rx_XXXX_q */
 158         spinlock_t ntb_rx_q_lock;
 159         void *rx_buff;
 160         unsigned int rx_index;
 161         unsigned int rx_max_entry;
 162         unsigned int rx_max_frame;
 163         unsigned int rx_alloc_entry;
 164         dma_cookie_t last_cookie;
 165         struct tasklet_struct rxc_db_work;
 166
 167         void (*event_handler)(void *data, int status);
 168         struct delayed_work link_work;
 169         struct work_struct link_cleanup;
 170
 171         struct dentry *debugfs_dir;
 172         struct dentry *debugfs_stats;
 173
 174         /* Stats */
 175         u64 rx_bytes;
 176         u64 rx_pkts;
 177         u64 rx_ring_empty;
 178         u64 rx_err_no_buf;
 179         u64 rx_err_oflow;
 180         u64 rx_err_ver;
 181         u64 rx_memcpy;
 182         u64 rx_async;
 183         u64 tx_bytes;
 184         u64 tx_pkts;
 185         u64 tx_ring_full;
 186         u64 tx_err_no_buf;
 187         u64 tx_memcpy;
 188         u64 tx_async;
 189 };
 190
 191 struct ntb_transport_mw {
 192         phys_addr_t phys_addr;
 193         resource_size_t phys_size;
 194         resource_size_t xlat_align;
 195         resource_size_t xlat_align_size;
 196         void __iomem *vbase;
 197         size_t xlat_size;
 198         size_t buff_size;
 199         void *virt_addr;
 200         dma_addr_t dma_addr;
 201 };
 202
 203 struct ntb_transport_client_dev {
 204         struct list_head entry;
 205         struct ntb_transport_ctx *nt;
 206         struct device dev;
 207 };
 208
 209 struct ntb_transport_ctx {
 210         struct list_head entry;
 211         struct list_head client_devs;
 212
 213         struct ntb_dev *ndev;
 214
 215         struct ntb_transport_mw *mw_vec;
 216         struct ntb_transport_qp *qp_vec;
 217         unsigned int mw_count;
 218         unsigned int qp_count;
 219         u64 qp_bitmap;
 220         u64 qp_bitmap_free;
 221
 222         bool link_is_up;
 223         struct delayed_work link_work;
 224         struct work_struct link_cleanup;
 225
 226         struct dentry *debugfs_node_dir;
 227 };
 228
 229 enum {
 230         DESC_DONE_FLAG = BIT(0),
 231         LINK_DOWN_FLAG = BIT(1),
 232 };
 233
 234 struct ntb_payload_header {
 235         unsigned int ver;
 236         unsigned int len;
 237         unsigned int flags;
 238 };
 239
 240 enum {
 241         VERSION = 0,
 242         QP_LINKS,
 243         NUM_QPS,
 244         NUM_MWS,
 245         MW0_SZ_HIGH,
 246         MW0_SZ_LOW,
 247 };
 248
 249 #define dev_client_dev(__dev) \
 250         container_of((__dev), struct ntb_transport_client_dev, dev)
 251
 252 #define drv_client(__drv) \
 253         container_of((__drv), struct ntb_transport_client, driver)
 254
 255 #define QP_TO_MW(nt, qp)        ((qp) % nt->mw_count)
 256 #define NTB_QP_DEF_NUM_ENTRIES  100
 257 #define NTB_LINK_DOWN_TIMEOUT   10
 258
 259 static void ntb_transport_rxc_db(unsigned long data);
 260 static const struct ntb_ctx_ops ntb_transport_ops;
 261 static struct ntb_client ntb_transport_client;
 262 static int ntb_async_tx_submit(struct ntb_transport_qp *qp,
 263                                struct ntb_queue_entry *entry);
 264 static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset);
 265 static int ntb_async_rx_submit(struct ntb_queue_entry *entry, void *offset);
 266 static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void *offset);
 267
 268
 269 static int ntb_transport_bus_match(struct device *dev,
 270                                    struct device_driver *drv)
 271 {
 272         return !strncmp(dev_name(dev), drv->name, strlen(drv->name));
 273 }
 274
 275 static int ntb_transport_bus_probe(struct device *dev)
 276 {
 277         const struct ntb_transport_client *client;
 278         int rc = -EINVAL;
 279
 280         get_device(dev);
 281
 282         client = drv_client(dev->driver);
 283         rc = client->probe(dev);
 284         if (rc)
 285                 put_device(dev);
 286
 287         return rc;
 288 }
 289
 290 static int ntb_transport_bus_remove(struct device *dev)
 291 {
 292         const struct ntb_transport_client *client;
 293
 294         client = drv_client(dev->driver);
 295         client->remove(dev);
 296
 297         put_device(dev);
 298
 299         return 0;
 300 }
 301
 302 static struct bus_type ntb_transport_bus = {
 303         .name = "ntb_transport",
 304         .match = ntb_transport_bus_match,
 305         .probe = ntb_transport_bus_probe,
 306         .remove = ntb_transport_bus_remove,
 307 };
 308
 309 static LIST_HEAD(ntb_transport_list);
 310
 311 static int ntb_bus_init(struct ntb_transport_ctx *nt)
 312 {
 313         list_add_tail(&nt->entry, &ntb_transport_list);
 314         return 0;
 315 }
 316
 317 static void ntb_bus_remove(struct ntb_transport_ctx *nt)
 318 {
 319         struct ntb_transport_client_dev *client_dev, *cd;
 320
 321         list_for_each_entry_safe(client_dev, cd, &nt->client_devs, entry) {
 322                 dev_err(client_dev->dev.parent, "%s still attached to bus, removing\n",
 323                         dev_name(&client_dev->dev));
 324                 list_del(&client_dev->entry);
 325                 device_unregister(&client_dev->dev);
 326         }
 327
 328         list_del(&nt->entry);
 329 }
 330
 331 static void ntb_transport_client_release(struct device *dev)
 332 {
 333         struct ntb_transport_client_dev *client_dev;
 334
 335         client_dev = dev_client_dev(dev);
 336         kfree(client_dev);
 337 }
 338
 339 /**
 340  * ntb_transport_unregister_client_dev - Unregister NTB client device
 341  * @device_name: Name of NTB client device
 342  *
 343  * Unregister an NTB client device with the NTB transport layer
 344  */
 345 void ntb_transport_unregister_client_dev(char *device_name)
 346 {
 347         struct ntb_transport_client_dev *client, *cd;
 348         struct ntb_transport_ctx *nt;
 349
 350         list_for_each_entry(nt, &ntb_transport_list, entry)
 351                 list_for_each_entry_safe(client, cd, &nt->client_devs, entry)
 352                         if (!strncmp(dev_name(&client->dev), device_name,
 353                                      strlen(device_name))) {
 354                                 list_del(&client->entry);
 355                                 device_unregister(&client->dev);
 356                         }
 357 }
 358 EXPORT_SYMBOL_GPL(ntb_transport_unregister_client_dev);
 359
 360 /**
 361  * ntb_transport_register_client_dev - Register NTB client device
 362  * @device_name: Name of NTB client device
 363  *
 364  * Register an NTB client device with the NTB transport layer
 365  */
 366 int ntb_transport_register_client_dev(char *device_name)
 367 {
 368         struct ntb_transport_client_dev *client_dev;
 369         struct ntb_transport_ctx *nt;
 370         int node;
 371         int rc, i = 0;
 372
 373         if (list_empty(&ntb_transport_list))
 374                 return -ENODEV;
 375
 376         list_for_each_entry(nt, &ntb_transport_list, entry) {
 377                 struct device *dev;
 378
 379                 node = dev_to_node(&nt->ndev->dev);
 380
 381                 client_dev = kzalloc_node(sizeof(*client_dev),
 382                                           GFP_KERNEL, node);
 383                 if (!client_dev) {
 384                         rc = -ENOMEM;
 385                         goto err;
 386                 }
 387
 388                 dev = &client_dev->dev;
 389
 390                 /* setup and register client devices */
 391                 dev_set_name(dev, "%s%d", device_name, i);
 392                 dev->bus = &ntb_transport_bus;
 393                 dev->release = ntb_transport_client_release;
 394                 dev->parent = &nt->ndev->dev;
 395
 396                 rc = device_register(dev);
 397                 if (rc) {
 398                         kfree(client_dev);
 399                         goto err;
 400                 }
 401
 402                 list_add_tail(&client_dev->entry, &nt->client_devs);
 403                 i++;
 404         }
 405
 406         return 0;
 407
 408 err:
 409         ntb_transport_unregister_client_dev(device_name);
 410
 411         return rc;
 412 }
 413 EXPORT_SYMBOL_GPL(ntb_transport_register_client_dev);
 414
 415 /**
 416  * ntb_transport_register_client - Register NTB client driver
 417  * @drv: NTB client driver to be registered
 418  *
 419  * Register an NTB client driver with the NTB transport layer
 420  *
 421  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 422  */
 423 int ntb_transport_register_client(struct ntb_transport_client *drv)
 424 {
 425         drv->driver.bus = &ntb_transport_bus;
 426
 427         if (list_empty(&ntb_transport_list))
 428                 return -ENODEV;
 429
 430         return driver_register(&drv->driver);
 431 }
 432 EXPORT_SYMBOL_GPL(ntb_transport_register_client);
 433
 434 /**
 435  * ntb_transport_unregister_client - Unregister NTB client driver
 436  * @drv: NTB client driver to be unregistered
 437  *
 438  * Unregister an NTB client driver with the NTB transport layer
 439  *
 440  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 441  */
 442 void ntb_transport_unregister_client(struct ntb_transport_client *drv)
 443 {
 444         driver_unregister(&drv->driver);
 445 }
 446 EXPORT_SYMBOL_GPL(ntb_transport_unregister_client);
 447
 448 static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count,
 449                             loff_t *offp)
 450 {
 451         struct ntb_transport_qp *qp;
 452         char *buf;
 453         ssize_t ret, out_offset, out_count;
 454
 455         qp = filp->private_data;
 456
 457         if (!qp || !qp->link_is_up)
 458                 return 0;
 459
 460         out_count = 1000;
 461
 462         buf = kmalloc(out_count, GFP_KERNEL);
 463         if (!buf)
 464                 return -ENOMEM;
 465
 466         out_offset = 0;
 467         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 468                                "\nNTB QP stats:\n\n");
 469         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 470                                "rx_bytes - \t%llu\n", qp->rx_bytes);
 471         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 472                                "rx_pkts - \t%llu\n", qp->rx_pkts);
 473         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 474                                "rx_memcpy - \t%llu\n", qp->rx_memcpy);
 475         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 476                                "rx_async - \t%llu\n", qp->rx_async);
 477         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 478                                "rx_ring_empty - %llu\n", qp->rx_ring_empty);
 479         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 480                                "rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
 481         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 482                                "rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
 483         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 484                                "rx_err_ver - \t%llu\n", qp->rx_err_ver);
 485         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 486                                "rx_buff - \t0x%p\n", qp->rx_buff);
 487         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 488                                "rx_index - \t%u\n", qp->rx_index);
 489         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 490                                "rx_max_entry - \t%u\n", qp->rx_max_entry);
 491         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 492                                "rx_alloc_entry - \t%u\n\n", qp->rx_alloc_entry);
 493
 494         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 495                                "tx_bytes - \t%llu\n", qp->tx_bytes);
 496         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 497                                "tx_pkts - \t%llu\n", qp->tx_pkts);
 498         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 499                                "tx_memcpy - \t%llu\n", qp->tx_memcpy);
 500         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 501                                "tx_async - \t%llu\n", qp->tx_async);
 502         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 503                                "tx_ring_full - \t%llu\n", qp->tx_ring_full);
 504         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 505                                "tx_err_no_buf - %llu\n", qp->tx_err_no_buf);
 506         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 507                                "tx_mw - \t0x%p\n", qp->tx_mw);
 508         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 509                                "tx_index (H) - \t%u\n", qp->tx_index);
 510         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 511                                "RRI (T) - \t%u\n",
 512                                qp->remote_rx_info->entry);
 513         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 514                                "tx_max_entry - \t%u\n", qp->tx_max_entry);
 515         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 516                                "free tx - \t%u\n",
 517                                ntb_transport_tx_free_entry(qp));
 518
 519         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 520                                "\n");
 521         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 522                                "Using TX DMA - \t%s\n",
 523                                qp->tx_dma_chan ? "Yes" : "No");
 524         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 525                                "Using RX DMA - \t%s\n",
 526                                qp->rx_dma_chan ? "Yes" : "No");
 527         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 528                                "QP Link - \t%s\n",
 529                                qp->link_is_up ? "Up" : "Down");
 530         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 531                                "\n");
 532
 533         if (out_offset > out_count)
 534                 out_offset = out_count;
 535
 536         ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
 537         kfree(buf);
 538         return ret;
 539 }
 540
 541 static const struct file_operations ntb_qp_debugfs_stats = {
 542         .owner = THIS_MODULE,
 543         .open = simple_open,
 544         .read = debugfs_read,
 545 };
 546
 547 static void ntb_list_add(spinlock_t *lock, struct list_head *entry,
 548                          struct list_head *list)
 549 {
 550         unsigned long flags;
 551
 552         spin_lock_irqsave(lock, flags);
 553         list_add_tail(entry, list);
 554         spin_unlock_irqrestore(lock, flags);
 555 }
 556
 557 static struct ntb_queue_entry *ntb_list_rm(spinlock_t *lock,
 558                                            struct list_head *list)
 559 {
 560         struct ntb_queue_entry *entry;
 561         unsigned long flags;
 562
 563         spin_lock_irqsave(lock, flags);
 564         if (list_empty(list)) {
 565                 entry = NULL;
 566                 goto out;
 567         }
 568         entry = list_first_entry(list, struct ntb_queue_entry, entry);
 569         list_del(&entry->entry);
 570
 571 out:
 572         spin_unlock_irqrestore(lock, flags);
 573
 574         return entry;
 575 }
 576
 577 static struct ntb_queue_entry *ntb_list_mv(spinlock_t *lock,
 578                                            struct list_head *list,
 579                                            struct list_head *to_list)
 580 {
 581         struct ntb_queue_entry *entry;
 582         unsigned long flags;
 583
 584         spin_lock_irqsave(lock, flags);
 585
 586         if (list_empty(list)) {
 587                 entry = NULL;
 588         } else {
 589                 entry = list_first_entry(list, struct ntb_queue_entry, entry);
 590                 list_move_tail(&entry->entry, to_list);
 591         }
 592
 593         spin_unlock_irqrestore(lock, flags);
 594
 595         return entry;
 596 }
 597
 598 static int ntb_transport_setup_qp_mw(struct ntb_transport_ctx *nt,
 599                                      unsigned int qp_num)
 600 {
 601         struct ntb_transport_qp *qp = &nt->qp_vec[qp_num];
 602         struct ntb_transport_mw *mw;
 603         struct ntb_dev *ndev = nt->ndev;
 604         struct ntb_queue_entry *entry;
 605         unsigned int rx_size, num_qps_mw;
 606         unsigned int mw_num, mw_count, qp_count;
 607         unsigned int i;
 608         int node;
 609
 610         mw_count = nt->mw_count;
 611         qp_count = nt->qp_count;
 612
 613         mw_num = QP_TO_MW(nt, qp_num);
 614         mw = &nt->mw_vec[mw_num];
 615
 616         if (!mw->virt_addr)
 617                 return -ENOMEM;
 618
 619         if (mw_num < qp_count % mw_count)
 620                 num_qps_mw = qp_count / mw_count + 1;
 621         else
 622                 num_qps_mw = qp_count / mw_count;
 623
 624         rx_size = (unsigned int)mw->xlat_size / num_qps_mw;
 625         qp->rx_buff = mw->virt_addr + rx_size * (qp_num / mw_count);
 626         rx_size -= sizeof(struct ntb_rx_info);
 627
 628         qp->remote_rx_info = qp->rx_buff + rx_size;
 629
 630         /* Due to housekeeping, there must be atleast 2 buffs */
 631         qp->rx_max_frame = min(transport_mtu, rx_size / 2);
 632         qp->rx_max_entry = rx_size / qp->rx_max_frame;
 633         qp->rx_index = 0;
 634
 635         /*
 636          * Checking to see if we have more entries than the default.
 637          * We should add additional entries if that is the case so we
 638          * can be in sync with the transport frames.
 639          */
 640         node = dev_to_node(&ndev->dev);
 641         for (i = qp->rx_alloc_entry; i < qp->rx_max_entry; i++) {
 642                 entry = kzalloc_node(sizeof(*entry), GFP_ATOMIC, node);
 643                 if (!entry)
 644                         return -ENOMEM;
 645
 646                 entry->qp = qp;
 647                 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry,
 648                              &qp->rx_free_q);
 649                 qp->rx_alloc_entry++;
 650         }
 651
 652         qp->remote_rx_info->entry = qp->rx_max_entry - 1;
 653
 654         /* setup the hdr offsets with 0's */
 655         for (i = 0; i < qp->rx_max_entry; i++) {
 656                 void *offset = (qp->rx_buff + qp->rx_max_frame * (i + 1) -
 657                                 sizeof(struct ntb_payload_header));
 658                 memset(offset, 0, sizeof(struct ntb_payload_header));
 659         }
 660
 661         qp->rx_pkts = 0;
 662         qp->tx_pkts = 0;
 663         qp->tx_index = 0;
 664
 665         return 0;
 666 }
 667
 668 static void ntb_free_mw(struct ntb_transport_ctx *nt, int num_mw)
 669 {
 670         struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
 671         struct pci_dev *pdev = nt->ndev->pdev;
 672
 673         if (!mw->virt_addr)
 674                 return;
 675
 676         ntb_mw_clear_trans(nt->ndev, PIDX, num_mw);
 677         dma_free_coherent(&pdev->dev, mw->buff_size,
 678                           mw->virt_addr, mw->dma_addr);
 679         mw->xlat_size = 0;
 680         mw->buff_size = 0;
 681         mw->virt_addr = NULL;
 682 }
 683
 684 static int ntb_set_mw(struct ntb_transport_ctx *nt, int num_mw,
 685                       resource_size_t size)
 686 {
 687         struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
 688         struct pci_dev *pdev = nt->ndev->pdev;
 689         size_t xlat_size, buff_size;
 690         int rc;
 691
 692         if (!size)
 693                 return -EINVAL;
 694
 695         xlat_size = round_up(size, mw->xlat_align_size);
 696         buff_size = round_up(size, mw->xlat_align);
 697
 698         /* No need to re-setup */
 699         if (mw->xlat_size == xlat_size)
 700                 return 0;
 701
 702         if (mw->buff_size)
 703                 ntb_free_mw(nt, num_mw);
 704
 705         /* Alloc memory for receiving data.  Must be aligned */
 706         mw->xlat_size = xlat_size;
 707         mw->buff_size = buff_size;
 708
 709         mw->virt_addr = dma_alloc_coherent(&pdev->dev, buff_size,
 710                                            &mw->dma_addr, GFP_KERNEL);
 711         if (!mw->virt_addr) {
 712                 mw->xlat_size = 0;
 713                 mw->buff_size = 0;
 714                 dev_err(&pdev->dev, "Unable to alloc MW buff of size %zu\n",
 715                         buff_size);
 716                 return -ENOMEM;
 717         }
 718
 719         /*
 720          * we must ensure that the memory address allocated is BAR size
 721          * aligned in order for the XLAT register to take the value. This
 722          * is a requirement of the hardware. It is recommended to setup CMA
 723          * for BAR sizes equal or greater than 4MB.
 724          */
 725         if (!IS_ALIGNED(mw->dma_addr, mw->xlat_align)) {
 726                 dev_err(&pdev->dev, "DMA memory %pad is not aligned\n",
 727                         &mw->dma_addr);
 728                 ntb_free_mw(nt, num_mw);
 729                 return -ENOMEM;
 730         }
 731
 732         /* Notify HW the memory location of the receive buffer */
 733         rc = ntb_mw_set_trans(nt->ndev, PIDX, num_mw, mw->dma_addr,
 734                               mw->xlat_size);
 735         if (rc) {
 736                 dev_err(&pdev->dev, "Unable to set mw%d translation", num_mw);
 737                 ntb_free_mw(nt, num_mw);
 738                 return -EIO;
 739         }
 740
 741         return 0;
 742 }
 743
 744 static void ntb_qp_link_down_reset(struct ntb_transport_qp *qp)
 745 {
 746         qp->link_is_up = false;
 747         qp->active = false;
 748
 749         qp->tx_index = 0;
 750         qp->rx_index = 0;
 751         qp->rx_bytes = 0;
 752         qp->rx_pkts = 0;
 753         qp->rx_ring_empty = 0;
 754         qp->rx_err_no_buf = 0;
 755         qp->rx_err_oflow = 0;
 756         qp->rx_err_ver = 0;
 757         qp->rx_memcpy = 0;
 758         qp->rx_async = 0;
 759         qp->tx_bytes = 0;
 760         qp->tx_pkts = 0;
 761         qp->tx_ring_full = 0;
 762         qp->tx_err_no_buf = 0;
 763         qp->tx_memcpy = 0;
 764         qp->tx_async = 0;
 765 }
 766
 767 static void ntb_qp_link_cleanup(struct ntb_transport_qp *qp)
 768 {
 769         struct ntb_transport_ctx *nt = qp->transport;
 770         struct pci_dev *pdev = nt->ndev->pdev;
 771
 772         dev_info(&pdev->dev, "qp %d: Link Cleanup\n", qp->qp_num);
 773
 774         cancel_delayed_work_sync(&qp->link_work);
 775         ntb_qp_link_down_reset(qp);
 776
 777         if (qp->event_handler)
 778                 qp->event_handler(qp->cb_data, qp->link_is_up);
 779 }
 780
 781 static void ntb_qp_link_cleanup_work(struct work_struct *work)
 782 {
 783         struct ntb_transport_qp *qp = container_of(work,
 784                                                    struct ntb_transport_qp,
 785                                                    link_cleanup);
 786         struct ntb_transport_ctx *nt = qp->transport;
 787
 788         ntb_qp_link_cleanup(qp);
 789
 790         if (nt->link_is_up)
 791                 schedule_delayed_work(&qp->link_work,
 792                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 793 }
 794
 795 static void ntb_qp_link_down(struct ntb_transport_qp *qp)
 796 {
 797         schedule_work(&qp->link_cleanup);
 798 }
 799
 800 static void ntb_transport_link_cleanup(struct ntb_transport_ctx *nt)
 801 {
 802         struct ntb_transport_qp *qp;
 803         u64 qp_bitmap_alloc;
 804         unsigned int i, count;
 805
 806         qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
 807
 808         /* Pass along the info to any clients */
 809         for (i = 0; i < nt->qp_count; i++)
 810                 if (qp_bitmap_alloc & BIT_ULL(i)) {
 811                         qp = &nt->qp_vec[i];
 812                         ntb_qp_link_cleanup(qp);
 813                         cancel_work_sync(&qp->link_cleanup);
 814                         cancel_delayed_work_sync(&qp->link_work);
 815                 }
 816
 817         if (!nt->link_is_up)
 818                 cancel_delayed_work_sync(&nt->link_work);
 819
 820         /* The scratchpad registers keep the values if the remote side
 821          * goes down, blast them now to give them a sane value the next
 822          * time they are accessed
 823          */
 824         count = ntb_spad_count(nt->ndev);
 825         for (i = 0; i < count; i++)
 826                 ntb_spad_write(nt->ndev, i, 0);
 827 }
 828
 829 static void ntb_transport_link_cleanup_work(struct work_struct *work)
 830 {
 831         struct ntb_transport_ctx *nt =
 832                 container_of(work, struct ntb_transport_ctx, link_cleanup);
 833
 834         ntb_transport_link_cleanup(nt);
 835 }
 836
 837 static void ntb_transport_event_callback(void *data)
 838 {
 839         struct ntb_transport_ctx *nt = data;
 840
 841         if (ntb_link_is_up(nt->ndev, NULL, NULL) == 1)
 842                 schedule_delayed_work(&nt->link_work, 0);
 843         else
 844                 schedule_work(&nt->link_cleanup);
 845 }
 846
 847 static void ntb_transport_link_work(struct work_struct *work)
 848 {
 849         struct ntb_transport_ctx *nt =
 850                 container_of(work, struct ntb_transport_ctx, link_work.work);
 851         struct ntb_dev *ndev = nt->ndev;
 852         struct pci_dev *pdev = ndev->pdev;
 853         resource_size_t size;
 854         u32 val;
 855         int rc = 0, i, spad;
 856
 857         /* send the local info, in the opposite order of the way we read it */
 858         for (i = 0; i < nt->mw_count; i++) {
 859                 size = nt->mw_vec[i].phys_size;
 860
 861                 if (max_mw_size && size > max_mw_size)
 862                         size = max_mw_size;
 863
 864                 spad = MW0_SZ_HIGH + (i * 2);
 865                 ntb_peer_spad_write(ndev, PIDX, spad, upper_32_bits(size));
 866
 867                 spad = MW0_SZ_LOW + (i * 2);
 868                 ntb_peer_spad_write(ndev, PIDX, spad, lower_32_bits(size));
 869         }
 870
 871         ntb_peer_spad_write(ndev, PIDX, NUM_MWS, nt->mw_count);
 872
 873         ntb_peer_spad_write(ndev, PIDX, NUM_QPS, nt->qp_count);
 874
 875         ntb_peer_spad_write(ndev, PIDX, VERSION, NTB_TRANSPORT_VERSION);
 876
 877         /* Query the remote side for its info */
 878         val = ntb_spad_read(ndev, VERSION);
 879         dev_dbg(&pdev->dev, "Remote version = %d\n", val);
 880         if (val != NTB_TRANSPORT_VERSION)
 881                 goto out;
 882
 883         val = ntb_spad_read(ndev, NUM_QPS);
 884         dev_dbg(&pdev->dev, "Remote max number of qps = %d\n", val);
 885         if (val != nt->qp_count)
 886                 goto out;
 887
 888         val = ntb_spad_read(ndev, NUM_MWS);
 889         dev_dbg(&pdev->dev, "Remote number of mws = %d\n", val);
 890         if (val != nt->mw_count)
 891                 goto out;
 892
 893         for (i = 0; i < nt->mw_count; i++) {
 894                 u64 val64;
 895
 896                 val = ntb_spad_read(ndev, MW0_SZ_HIGH + (i * 2));
 897                 val64 = (u64)val << 32;
 898
 899                 val = ntb_spad_read(ndev, MW0_SZ_LOW + (i * 2));
 900                 val64 |= val;
 901
 902                 dev_dbg(&pdev->dev, "Remote MW%d size = %#llx\n", i, val64);
 903
 904                 rc = ntb_set_mw(nt, i, val64);
 905                 if (rc)
 906                         goto out1;
 907         }
 908
 909         nt->link_is_up = true;
 910
 911         for (i = 0; i < nt->qp_count; i++) {
 912                 struct ntb_transport_qp *qp = &nt->qp_vec[i];
 913
 914                 ntb_transport_setup_qp_mw(nt, i);
 915
 916                 if (qp->client_ready)
 917                         schedule_delayed_work(&qp->link_work, 0);
 918         }
 919
 920         return;
 921
 922 out1:
 923         for (i = 0; i < nt->mw_count; i++)
 924                 ntb_free_mw(nt, i);
 925
 926         /* if there's an actual failure, we should just bail */
 927         if (rc < 0) {
 928                 ntb_link_disable(ndev);
 929                 return;
 930         }
 931
 932 out:
 933         if (ntb_link_is_up(ndev, NULL, NULL) == 1)
 934                 schedule_delayed_work(&nt->link_work,
 935                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 936 }
 937
 938 static void ntb_qp_link_work(struct work_struct *work)
 939 {
 940         struct ntb_transport_qp *qp = container_of(work,
 941                                                    struct ntb_transport_qp,
 942                                                    link_work.work);
 943         struct pci_dev *pdev = qp->ndev->pdev;
 944         struct ntb_transport_ctx *nt = qp->transport;
 945         int val;
 946
 947         WARN_ON(!nt->link_is_up);
 948
 949         val = ntb_spad_read(nt->ndev, QP_LINKS);
 950
 951         ntb_peer_spad_write(nt->ndev, PIDX, QP_LINKS, val | BIT(qp->qp_num));
 952
 953         /* query remote spad for qp ready bits */
 954         dev_dbg_ratelimited(&pdev->dev, "Remote QP link status = %x\n", val);
 955
 956         /* See if the remote side is up */
 957         if (val & BIT(qp->qp_num)) {
 958                 dev_info(&pdev->dev, "qp %d: Link Up\n", qp->qp_num);
 959                 qp->link_is_up = true;
 960                 qp->active = true;
 961
 962                 if (qp->event_handler)
 963                         qp->event_handler(qp->cb_data, qp->link_is_up);
 964
 965                 if (qp->active)
 966                         tasklet_schedule(&qp->rxc_db_work);
 967         } else if (nt->link_is_up)
 968                 schedule_delayed_work(&qp->link_work,
 969                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 970 }
 971
 972 static int ntb_transport_init_queue(struct ntb_transport_ctx *nt,
 973                                     unsigned int qp_num)
 974 {
 975         struct ntb_transport_qp *qp;
 976         phys_addr_t mw_base;
 977         resource_size_t mw_size;
 978         unsigned int num_qps_mw, tx_size;
 979         unsigned int mw_num, mw_count, qp_count;
 980         u64 qp_offset;
 981
 982         mw_count = nt->mw_count;
 983         qp_count = nt->qp_count;
 984
 985         mw_num = QP_TO_MW(nt, qp_num);
 986
 987         qp = &nt->qp_vec[qp_num];
 988         qp->qp_num = qp_num;
 989         qp->transport = nt;
 990         qp->ndev = nt->ndev;
 991         qp->client_ready = false;
 992         qp->event_handler = NULL;
 993         ntb_qp_link_down_reset(qp);
 994
 995         if (mw_num < qp_count % mw_count)
 996                 num_qps_mw = qp_count / mw_count + 1;
 997         else
 998                 num_qps_mw = qp_count / mw_count;
 999
1000         mw_base = nt->mw_vec[mw_num].phys_addr;
1001         mw_size = nt->mw_vec[mw_num].phys_size;
1002
1003         tx_size = (unsigned int)mw_size / num_qps_mw;
1004         qp_offset = tx_size * (qp_num / mw_count);
1005
1006         qp->tx_mw = nt->mw_vec[mw_num].vbase + qp_offset;
1007         if (!qp->tx_mw)
1008                 return -EINVAL;
1009
1010         qp->tx_mw_phys = mw_base + qp_offset;
1011         if (!qp->tx_mw_phys)
1012                 return -EINVAL;
1013
1014         tx_size -= sizeof(struct ntb_rx_info);
1015         qp->rx_info = qp->tx_mw + tx_size;
1016
1017         /* Due to housekeeping, there must be atleast 2 buffs */
1018         qp->tx_max_frame = min(transport_mtu, tx_size / 2);
1019         qp->tx_max_entry = tx_size / qp->tx_max_frame;
1020
1021         if (nt->debugfs_node_dir) {
1022                 char debugfs_name[4];
1023
1024                 snprintf(debugfs_name, 4, "qp%d", qp_num);
1025                 qp->debugfs_dir = debugfs_create_dir(debugfs_name,
1026                                                      nt->debugfs_node_dir);
1027
1028                 qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR,
1029                                                         qp->debugfs_dir, qp,
1030                                                         &ntb_qp_debugfs_stats);
1031         } else {
1032                 qp->debugfs_dir = NULL;
1033                 qp->debugfs_stats = NULL;
1034         }
1035
1036         INIT_DELAYED_WORK(&qp->link_work, ntb_qp_link_work);
1037         INIT_WORK(&qp->link_cleanup, ntb_qp_link_cleanup_work);
1038
1039         spin_lock_init(&qp->ntb_rx_q_lock);
1040         spin_lock_init(&qp->ntb_tx_free_q_lock);
1041
1042         INIT_LIST_HEAD(&qp->rx_post_q);
1043         INIT_LIST_HEAD(&qp->rx_pend_q);
1044         INIT_LIST_HEAD(&qp->rx_free_q);
1045         INIT_LIST_HEAD(&qp->tx_free_q);
1046
1047         tasklet_init(&qp->rxc_db_work, ntb_transport_rxc_db,
1048                      (unsigned long)qp);
1049
1050         return 0;
1051 }
1052
1053 static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev)
1054 {
1055         struct ntb_transport_ctx *nt;
1056         struct ntb_transport_mw *mw;
1057         unsigned int mw_count, qp_count, spad_count, max_mw_count_for_spads;
1058         u64 qp_bitmap;
1059         int node;
1060         int rc, i;
1061
1062         mw_count = ntb_mw_count(ndev, PIDX);
1063
1064         if (!ndev->ops->mw_set_trans) {
1065                 dev_err(&ndev->dev, "Inbound MW based NTB API is required\n");
1066                 return -EINVAL;
1067         }
1068
1069         if (ntb_db_is_unsafe(ndev))
1070                 dev_dbg(&ndev->dev,
1071                         "doorbell is unsafe, proceed anyway...\n");
1072         if (ntb_spad_is_unsafe(ndev))
1073                 dev_dbg(&ndev->dev,
1074                         "scratchpad is unsafe, proceed anyway...\n");
1075
1076         if (ntb_peer_port_count(ndev) != NTB_DEF_PEER_CNT)
1077                 dev_warn(&ndev->dev, "Multi-port NTB devices unsupported\n");
1078
1079         node = dev_to_node(&ndev->dev);
1080
1081         nt = kzalloc_node(sizeof(*nt), GFP_KERNEL, node);
1082         if (!nt)
1083                 return -ENOMEM;
1084
1085         nt->ndev = ndev;
1086         spad_count = ntb_spad_count(ndev);
1087
1088         /* Limit the MW's based on the availability of scratchpads */
1089
1090         if (spad_count < NTB_TRANSPORT_MIN_SPADS) {
1091                 nt->mw_count = 0;
1092                 rc = -EINVAL;
1093                 goto err;
1094         }
1095
1096         max_mw_count_for_spads = (spad_count - MW0_SZ_HIGH) / 2;
1097         nt->mw_count = min(mw_count, max_mw_count_for_spads);
1098
1099         nt->mw_vec = kzalloc_node(mw_count * sizeof(*nt->mw_vec),
1100                                   GFP_KERNEL, node);
1101         if (!nt->mw_vec) {
1102                 rc = -ENOMEM;
1103                 goto err;
1104         }
1105
1106         for (i = 0; i < mw_count; i++) {
1107                 mw = &nt->mw_vec[i];
1108
1109                 rc = ntb_mw_get_align(ndev, PIDX, i, &mw->xlat_align,
1110                                       &mw->xlat_align_size, NULL);
1111                 if (rc)
1112                         goto err1;
1113
1114                 rc = ntb_peer_mw_get_addr(ndev, i, &mw->phys_addr,
1115                                           &mw->phys_size);
1116                 if (rc)
1117                         goto err1;
1118
1119                 mw->vbase = ioremap_wc(mw->phys_addr, mw->phys_size);
1120                 if (!mw->vbase) {
1121                         rc = -ENOMEM;
1122                         goto err1;
1123                 }
1124
1125                 mw->buff_size = 0;
1126                 mw->xlat_size = 0;
1127                 mw->virt_addr = NULL;
1128                 mw->dma_addr = 0;
1129         }
1130
1131         qp_bitmap = ntb_db_valid_mask(ndev);
1132
1133         qp_count = ilog2(qp_bitmap);
1134         if (max_num_clients && max_num_clients < qp_count)
1135                 qp_count = max_num_clients;
1136         else if (nt->mw_count < qp_count)
1137                 qp_count = nt->mw_count;
1138
1139         qp_bitmap &= BIT_ULL(qp_count) - 1;
1140
1141         nt->qp_count = qp_count;
1142         nt->qp_bitmap = qp_bitmap;
1143         nt->qp_bitmap_free = qp_bitmap;
1144
1145         nt->qp_vec = kzalloc_node(qp_count * sizeof(*nt->qp_vec),
1146                                   GFP_KERNEL, node);
1147         if (!nt->qp_vec) {
1148                 rc = -ENOMEM;
1149                 goto err1;
1150         }
1151
1152         if (nt_debugfs_dir) {
1153                 nt->debugfs_node_dir =
1154                         debugfs_create_dir(pci_name(ndev->pdev),
1155                                            nt_debugfs_dir);
1156         }
1157
1158         for (i = 0; i < qp_count; i++) {
1159                 rc = ntb_transport_init_queue(nt, i);
1160                 if (rc)
1161                         goto err2;
1162         }
1163
1164         INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work);
1165         INIT_WORK(&nt->link_cleanup, ntb_transport_link_cleanup_work);
1166
1167         rc = ntb_set_ctx(ndev, nt, &ntb_transport_ops);
1168         if (rc)
1169                 goto err2;
1170
1171         INIT_LIST_HEAD(&nt->client_devs);
1172         rc = ntb_bus_init(nt);
1173         if (rc)
1174                 goto err3;
1175
1176         nt->link_is_up = false;
1177         ntb_link_enable(ndev, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
1178         ntb_link_event(ndev);
1179
1180         return 0;
1181
1182 err3:
1183         ntb_clear_ctx(ndev);
1184 err2:
1185         kfree(nt->qp_vec);
1186 err1:
1187         while (i--) {
1188                 mw = &nt->mw_vec[i];
1189                 iounmap(mw->vbase);
1190         }
1191         kfree(nt->mw_vec);
1192 err:
1193         kfree(nt);
1194         return rc;
1195 }
1196
1197 static void ntb_transport_free(struct ntb_client *self, struct ntb_dev *ndev)
1198 {
1199         struct ntb_transport_ctx *nt = ndev->ctx;
1200         struct ntb_transport_qp *qp;
1201         u64 qp_bitmap_alloc;
1202         int i;
1203
1204         ntb_transport_link_cleanup(nt);
1205         cancel_work_sync(&nt->link_cleanup);
1206         cancel_delayed_work_sync(&nt->link_work);
1207
1208         qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
1209
1210         /* verify that all the qp's are freed */
1211         for (i = 0; i < nt->qp_count; i++) {
1212                 qp = &nt->qp_vec[i];
1213                 if (qp_bitmap_alloc & BIT_ULL(i))
1214                         ntb_transport_free_queue(qp);
1215                 debugfs_remove_recursive(qp->debugfs_dir);
1216         }
1217
1218         ntb_link_disable(ndev);
1219         ntb_clear_ctx(ndev);
1220
1221         ntb_bus_remove(nt);
1222
1223         for (i = nt->mw_count; i--; ) {
1224                 ntb_free_mw(nt, i);
1225                 iounmap(nt->mw_vec[i].vbase);
1226         }
1227
1228         kfree(nt->qp_vec);
1229         kfree(nt->mw_vec);
1230         kfree(nt);
1231 }
1232
1233 static void ntb_complete_rxc(struct ntb_transport_qp *qp)
1234 {
1235         struct ntb_queue_entry *entry;
1236         void *cb_data;
1237         unsigned int len;
1238         unsigned long irqflags;
1239
1240         spin_lock_irqsave(&qp->ntb_rx_q_lock, irqflags);
1241
1242         while (!list_empty(&qp->rx_post_q)) {
1243                 entry = list_first_entry(&qp->rx_post_q,
1244                                          struct ntb_queue_entry, entry);
1245                 if (!(entry->flags & DESC_DONE_FLAG))
1246                         break;
1247
1248                 entry->rx_hdr->flags = 0;
1249                 iowrite32(entry->rx_index, &qp->rx_info->entry);
1250
1251                 cb_data = entry->cb_data;
1252                 len = entry->len;
1253
1254                 list_move_tail(&entry->entry, &qp->rx_free_q);
1255
1256                 spin_unlock_irqrestore(&qp->ntb_rx_q_lock, irqflags);
1257
1258                 if (qp->rx_handler && qp->client_ready)
1259                         qp->rx_handler(qp, qp->cb_data, cb_data, len);
1260
1261                 spin_lock_irqsave(&qp->ntb_rx_q_lock, irqflags);
1262         }
1263
1264         spin_unlock_irqrestore(&qp->ntb_rx_q_lock, irqflags);
1265 }
1266
1267 static void ntb_rx_copy_callback(void *data,
1268                                  const struct dmaengine_result *res)
1269 {
1270         struct ntb_queue_entry *entry = data;
1271
1272         /* we need to check DMA results if we are using DMA */
1273         if (res) {
1274                 enum dmaengine_tx_result dma_err = res->result;
1275
1276                 switch (dma_err) {
1277                 case DMA_TRANS_READ_FAILED:
1278                 case DMA_TRANS_WRITE_FAILED:
1279                         entry->errors++;
1280                 case DMA_TRANS_ABORTED:
1281                 {
1282                         struct ntb_transport_qp *qp = entry->qp;
1283                         void *offset = qp->rx_buff + qp->rx_max_frame *
1284                                         qp->rx_index;
1285
1286                         ntb_memcpy_rx(entry, offset);
1287                         qp->rx_memcpy++;
1288                         return;
1289                 }
1290
1291                 case DMA_TRANS_NOERROR:
1292                 default:
1293                         break;
1294                 }
1295         }
1296
1297         entry->flags |= DESC_DONE_FLAG;
1298
1299         ntb_complete_rxc(entry->qp);
1300 }
1301
1302 static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void *offset)
1303 {
1304         void *buf = entry->buf;
1305         size_t len = entry->len;
1306
1307         memcpy(buf, offset, len);
1308
1309         /* Ensure that the data is fully copied out before clearing the flag */
1310         wmb();
1311
1312         ntb_rx_copy_callback(entry, NULL);
1313 }
1314
1315 static int ntb_async_rx_submit(struct ntb_queue_entry *entry, void *offset)
1316 {
1317         struct dma_async_tx_descriptor *txd;
1318         struct ntb_transport_qp *qp = entry->qp;
1319         struct dma_chan *chan = qp->rx_dma_chan;
1320         struct dma_device *device;
1321         size_t pay_off, buff_off, len;
1322         struct dmaengine_unmap_data *unmap;
1323         dma_cookie_t cookie;
1324         void *buf = entry->buf;
1325
1326         len = entry->len;
1327         device = chan->device;
1328         pay_off = (size_t)offset & ~PAGE_MASK;
1329         buff_off = (size_t)buf & ~PAGE_MASK;
1330
1331         if (!is_dma_copy_aligned(device, pay_off, buff_off, len))
1332                 goto err;
1333
1334         unmap = dmaengine_get_unmap_data(device->dev, 2, GFP_NOWAIT);
1335         if (!unmap)
1336                 goto err;
1337
1338         unmap->len = len;
1339         unmap->addr[0] = dma_map_page(device->dev, virt_to_page(offset),
1340                                       pay_off, len, DMA_TO_DEVICE);
1341         if (dma_mapping_error(device->dev, unmap->addr[0]))
1342                 goto err_get_unmap;
1343
1344         unmap->to_cnt = 1;
1345
1346         unmap->addr[1] = dma_map_page(device->dev, virt_to_page(buf),
1347                                       buff_off, len, DMA_FROM_DEVICE);
1348         if (dma_mapping_error(device->dev, unmap->addr[1]))
1349                 goto err_get_unmap;
1350
1351         unmap->from_cnt = 1;
1352
1353         txd = device->device_prep_dma_memcpy(chan, unmap->addr[1],
1354                                              unmap->addr[0], len,
1355                                              DMA_PREP_INTERRUPT);
1356         if (!txd)
1357                 goto err_get_unmap;
1358
1359         txd->callback_result = ntb_rx_copy_callback;
1360         txd->callback_param = entry;
1361         dma_set_unmap(txd, unmap);
1362
1363         cookie = dmaengine_submit(txd);
1364         if (dma_submit_error(cookie))
1365                 goto err_set_unmap;
1366
1367         dmaengine_unmap_put(unmap);
1368
1369         qp->last_cookie = cookie;
1370
1371         qp->rx_async++;
1372
1373         return 0;
1374
1375 err_set_unmap:
1376         dmaengine_unmap_put(unmap);
1377 err_get_unmap:
1378         dmaengine_unmap_put(unmap);
1379 err:
1380         return -ENXIO;
1381 }
1382
1383 static void ntb_async_rx(struct ntb_queue_entry *entry, void *offset)
1384 {
1385         struct ntb_transport_qp *qp = entry->qp;
1386         struct dma_chan *chan = qp->rx_dma_chan;
1387         int res;
1388
1389         if (!chan)
1390                 goto err;
1391
1392         if (entry->len < copy_bytes)
1393                 goto err;
1394
1395         res = ntb_async_rx_submit(entry, offset);
1396         if (res < 0)
1397                 goto err;
1398
1399         if (!entry->retries)
1400                 qp->rx_async++;
1401
1402         return;
1403
1404 err:
1405         ntb_memcpy_rx(entry, offset);
1406         qp->rx_memcpy++;
1407 }
1408
1409 static int ntb_process_rxc(struct ntb_transport_qp *qp)
1410 {
1411         struct ntb_payload_header *hdr;
1412         struct ntb_queue_entry *entry;
1413         void *offset;
1414
1415         offset = qp->rx_buff + qp->rx_max_frame * qp->rx_index;
1416         hdr = offset + qp->rx_max_frame - sizeof(struct ntb_payload_header);
1417
1418         dev_dbg(&qp->ndev->pdev->dev, "qp %d: RX ver %u len %d flags %x\n",
1419                 qp->qp_num, hdr->ver, hdr->len, hdr->flags);
1420
1421         if (!(hdr->flags & DESC_DONE_FLAG)) {
1422                 dev_dbg(&qp->ndev->pdev->dev, "done flag not set\n");
1423                 qp->rx_ring_empty++;
1424                 return -EAGAIN;
1425         }
1426
1427         if (hdr->flags & LINK_DOWN_FLAG) {
1428                 dev_dbg(&qp->ndev->pdev->dev, "link down flag set\n");
1429                 ntb_qp_link_down(qp);
1430                 hdr->flags = 0;
1431                 return -EAGAIN;
1432         }
1433
1434         if (hdr->ver != (u32)qp->rx_pkts) {
1435                 dev_dbg(&qp->ndev->pdev->dev,
1436                         "version mismatch, expected %llu - got %u\n",
1437                         qp->rx_pkts, hdr->ver);
1438                 qp->rx_err_ver++;
1439                 return -EIO;
1440         }
1441
1442         entry = ntb_list_mv(&qp->ntb_rx_q_lock, &qp->rx_pend_q, &qp->rx_post_q);
1443         if (!entry) {
1444                 dev_dbg(&qp->ndev->pdev->dev, "no receive buffer\n");
1445                 qp->rx_err_no_buf++;
1446                 return -EAGAIN;
1447         }
1448
1449         entry->rx_hdr = hdr;
1450         entry->rx_index = qp->rx_index;
1451
1452         if (hdr->len > entry->len) {
1453                 dev_dbg(&qp->ndev->pdev->dev,
1454                         "receive buffer overflow! Wanted %d got %d\n",
1455                         hdr->len, entry->len);
1456                 qp->rx_err_oflow++;
1457
1458                 entry->len = -EIO;
1459                 entry->flags |= DESC_DONE_FLAG;
1460
1461                 ntb_complete_rxc(qp);
1462         } else {
1463                 dev_dbg(&qp->ndev->pdev->dev,
1464                         "RX OK index %u ver %u size %d into buf size %d\n",
1465                         qp->rx_index, hdr->ver, hdr->len, entry->len);
1466
1467                 qp->rx_bytes += hdr->len;
1468                 qp->rx_pkts++;
1469
1470                 entry->len = hdr->len;
1471
1472                 ntb_async_rx(entry, offset);
1473         }
1474
1475         qp->rx_index++;
1476         qp->rx_index %= qp->rx_max_entry;
1477
1478         return 0;
1479 }
1480
1481 static void ntb_transport_rxc_db(unsigned long data)
1482 {
1483         struct ntb_transport_qp *qp = (void *)data;
1484         int rc, i;
1485
1486         dev_dbg(&qp->ndev->pdev->dev, "%s: doorbell %d received\n",
1487                 __func__, qp->qp_num);
1488
1489         /* Limit the number of packets processed in a single interrupt to
1490          * provide fairness to others
1491          */
1492         for (i = 0; i < qp->rx_max_entry; i++) {
1493                 rc = ntb_process_rxc(qp);
1494                 if (rc)
1495                         break;
1496         }
1497
1498         if (i && qp->rx_dma_chan)
1499                 dma_async_issue_pending(qp->rx_dma_chan);
1500
1501         if (i == qp->rx_max_entry) {
1502                 /* there is more work to do */
1503                 if (qp->active)
1504                         tasklet_schedule(&qp->rxc_db_work);
1505         } else if (ntb_db_read(qp->ndev) & BIT_ULL(qp->qp_num)) {
1506                 /* the doorbell bit is set: clear it */
1507                 ntb_db_clear(qp->ndev, BIT_ULL(qp->qp_num));
1508                 /* ntb_db_read ensures ntb_db_clear write is committed */
1509                 ntb_db_read(qp->ndev);
1510
1511                 /* an interrupt may have arrived between finishing
1512                  * ntb_process_rxc and clearing the doorbell bit:
1513                  * there might be some more work to do.
1514                  */
1515                 if (qp->active)
1516                         tasklet_schedule(&qp->rxc_db_work);
1517         }
1518 }
1519
1520 static void ntb_tx_copy_callback(void *data,
1521                                  const struct dmaengine_result *res)
1522 {
1523         struct ntb_queue_entry *entry = data;
1524         struct ntb_transport_qp *qp = entry->qp;
1525         struct ntb_payload_header __iomem *hdr = entry->tx_hdr;
1526
1527         /* we need to check DMA results if we are using DMA */
1528         if (res) {
1529                 enum dmaengine_tx_result dma_err = res->result;
1530
1531                 switch (dma_err) {
1532                 case DMA_TRANS_READ_FAILED:
1533                 case DMA_TRANS_WRITE_FAILED:
1534                         entry->errors++;
1535                 case DMA_TRANS_ABORTED:
1536                 {
1537                         void __iomem *offset =
1538                                 qp->tx_mw + qp->tx_max_frame *
1539                                 entry->tx_index;
1540
1541                         /* resubmit via CPU */
1542                         ntb_memcpy_tx(entry, offset);
1543                         qp->tx_memcpy++;
1544                         return;
1545                 }
1546
1547                 case DMA_TRANS_NOERROR:
1548                 default:
1549                         break;
1550                 }
1551         }
1552
1553         iowrite32(entry->flags | DESC_DONE_FLAG, &hdr->flags);
1554
1555         ntb_peer_db_set(qp->ndev, BIT_ULL(qp->qp_num));
1556
1557         /* The entry length can only be zero if the packet is intended to be a
1558          * "link down" or similar.  Since no payload is being sent in these
1559          * cases, there is nothing to add to the completion queue.
1560          */
1561         if (entry->len > 0) {
1562                 qp->tx_bytes += entry->len;
1563
1564                 if (qp->tx_handler)
1565                         qp->tx_handler(qp, qp->cb_data, entry->cb_data,
1566                                        entry->len);
1567         }
1568
1569         ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q);
1570 }
1571
1572 static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset)
1573 {
1574 #ifdef ARCH_HAS_NOCACHE_UACCESS
1575         /*
1576          * Using non-temporal mov to improve performance on non-cached
1577          * writes, even though we aren't actually copying from user space.
1578          */
1579         __copy_from_user_inatomic_nocache(offset, entry->buf, entry->len);
1580 #else
1581         memcpy_toio(offset, entry->buf, entry->len);
1582 #endif
1583
1584         /* Ensure that the data is fully copied out before setting the flags */
1585         wmb();
1586
1587         ntb_tx_copy_callback(entry, NULL);
1588 }
1589
1590 static int ntb_async_tx_submit(struct ntb_transport_qp *qp,
1591                                struct ntb_queue_entry *entry)
1592 {
1593         struct dma_async_tx_descriptor *txd;
1594         struct dma_chan *chan = qp->tx_dma_chan;
1595         struct dma_device *device;
1596         size_t len = entry->len;
1597         void *buf = entry->buf;
1598         size_t dest_off, buff_off;
1599         struct dmaengine_unmap_data *unmap;
1600         dma_addr_t dest;
1601         dma_cookie_t cookie;
1602
1603         device = chan->device;
1604         dest = qp->tx_mw_phys + qp->tx_max_frame * entry->tx_index;
1605         buff_off = (size_t)buf & ~PAGE_MASK;
1606         dest_off = (size_t)dest & ~PAGE_MASK;
1607
1608         if (!is_dma_copy_aligned(device, buff_off, dest_off, len))
1609                 goto err;
1610
1611         unmap = dmaengine_get_unmap_data(device->dev, 1, GFP_NOWAIT);
1612         if (!unmap)
1613                 goto err;
1614
1615         unmap->len = len;
1616         unmap->addr[0] = dma_map_page(device->dev, virt_to_page(buf),
1617                                       buff_off, len, DMA_TO_DEVICE);
1618         if (dma_mapping_error(device->dev, unmap->addr[0]))
1619                 goto err_get_unmap;
1620
1621         unmap->to_cnt = 1;
1622
1623         txd = device->device_prep_dma_memcpy(chan, dest, unmap->addr[0], len,
1624                                              DMA_PREP_INTERRUPT);
1625         if (!txd)
1626                 goto err_get_unmap;
1627
1628         txd->callback_result = ntb_tx_copy_callback;
1629         txd->callback_param = entry;
1630         dma_set_unmap(txd, unmap);
1631
1632         cookie = dmaengine_submit(txd);
1633         if (dma_submit_error(cookie))
1634                 goto err_set_unmap;
1635
1636         dmaengine_unmap_put(unmap);
1637
1638         dma_async_issue_pending(chan);
1639
1640         return 0;
1641 err_set_unmap:
1642         dmaengine_unmap_put(unmap);
1643 err_get_unmap:
1644         dmaengine_unmap_put(unmap);
1645 err:
1646         return -ENXIO;
1647 }
1648
1649 static void ntb_async_tx(struct ntb_transport_qp *qp,
1650                          struct ntb_queue_entry *entry)
1651 {
1652         struct ntb_payload_header __iomem *hdr;
1653         struct dma_chan *chan = qp->tx_dma_chan;
1654         void __iomem *offset;
1655         int res;
1656
1657         entry->tx_index = qp->tx_index;
1658         offset = qp->tx_mw + qp->tx_max_frame * entry->tx_index;
1659         hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
1660         entry->tx_hdr = hdr;
1661
1662         iowrite32(entry->len, &hdr->len);
1663         iowrite32((u32)qp->tx_pkts, &hdr->ver);
1664
1665         if (!chan)
1666                 goto err;
1667
1668         if (entry->len < copy_bytes)
1669                 goto err;
1670
1671         res = ntb_async_tx_submit(qp, entry);
1672         if (res < 0)
1673                 goto err;
1674
1675         if (!entry->retries)
1676                 qp->tx_async++;
1677
1678         return;
1679
1680 err:
1681         ntb_memcpy_tx(entry, offset);
1682         qp->tx_memcpy++;
1683 }
1684
1685 static int ntb_process_tx(struct ntb_transport_qp *qp,
1686                           struct ntb_queue_entry *entry)
1687 {
1688         if (qp->tx_index == qp->remote_rx_info->entry) {
1689                 qp->tx_ring_full++;
1690                 return -EAGAIN;
1691         }
1692
1693         if (entry->len > qp->tx_max_frame - sizeof(struct ntb_payload_header)) {
1694                 if (qp->tx_handler)
1695                         qp->tx_handler(qp, qp->cb_data, NULL, -EIO);
1696
1697                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1698                              &qp->tx_free_q);
1699                 return 0;
1700         }
1701
1702         ntb_async_tx(qp, entry);
1703
1704         qp->tx_index++;
1705         qp->tx_index %= qp->tx_max_entry;
1706
1707         qp->tx_pkts++;
1708
1709         return 0;
1710 }
1711
1712 static void ntb_send_link_down(struct ntb_transport_qp *qp)
1713 {
1714         struct pci_dev *pdev = qp->ndev->pdev;
1715         struct ntb_queue_entry *entry;
1716         int i, rc;
1717
1718         if (!qp->link_is_up)
1719                 return;
1720
1721         dev_info(&pdev->dev, "qp %d: Send Link Down\n", qp->qp_num);
1722
1723         for (i = 0; i < NTB_LINK_DOWN_TIMEOUT; i++) {
1724                 entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1725                 if (entry)
1726                         break;
1727                 msleep(100);
1728         }
1729
1730         if (!entry)
1731                 return;
1732
1733         entry->cb_data = NULL;
1734         entry->buf = NULL;
1735         entry->len = 0;
1736         entry->flags = LINK_DOWN_FLAG;
1737
1738         rc = ntb_process_tx(qp, entry);
1739         if (rc)
1740                 dev_err(&pdev->dev, "ntb: QP%d unable to send linkdown msg\n",
1741                         qp->qp_num);
1742
1743         ntb_qp_link_down_reset(qp);
1744 }
1745
1746 static bool ntb_dma_filter_fn(struct dma_chan *chan, void *node)
1747 {
1748         return dev_to_node(&chan->dev->device) == (int)(unsigned long)node;
1749 }
1750
1751 /**
1752  * ntb_transport_create_queue - Create a new NTB transport layer queue
1753  * @rx_handler: receive callback function
1754  * @tx_handler: transmit callback function
1755  * @event_handler: event callback function
1756  *
1757  * Create a new NTB transport layer queue and provide the queue with a callback
1758  * routine for both transmit and receive.  The receive callback routine will be
1759  * used to pass up data when the transport has received it on the queue.   The
1760  * transmit callback routine will be called when the transport has completed the
1761  * transmission of the data on the queue and the data is ready to be freed.
1762  *
1763  * RETURNS: pointer to newly created ntb_queue, NULL on error.
1764  */
1765 struct ntb_transport_qp *
1766 ntb_transport_create_queue(void *data, struct device *client_dev,
1767                            const struct ntb_queue_handlers *handlers)
1768 {
1769         struct ntb_dev *ndev;
1770         struct pci_dev *pdev;
1771         struct ntb_transport_ctx *nt;
1772         struct ntb_queue_entry *entry;
1773         struct ntb_transport_qp *qp;
1774         u64 qp_bit;
1775         unsigned int free_queue;
1776         dma_cap_mask_t dma_mask;
1777         int node;
1778         int i;
1779
1780         ndev = dev_ntb(client_dev->parent);
1781         pdev = ndev->pdev;
1782         nt = ndev->ctx;
1783
1784         node = dev_to_node(&ndev->dev);
1785
1786         free_queue = ffs(nt->qp_bitmap_free);
1787         if (!free_queue)
1788                 goto err;
1789
1790         /* decrement free_queue to make it zero based */
1791         free_queue--;
1792
1793         qp = &nt->qp_vec[free_queue];
1794         qp_bit = BIT_ULL(qp->qp_num);
1795
1796         nt->qp_bitmap_free &= ~qp_bit;
1797
1798         qp->cb_data = data;
1799         qp->rx_handler = handlers->rx_handler;
1800         qp->tx_handler = handlers->tx_handler;
1801         qp->event_handler = handlers->event_handler;
1802
1803         dma_cap_zero(dma_mask);
1804         dma_cap_set(DMA_MEMCPY, dma_mask);
1805
1806         if (use_dma) {
1807                 qp->tx_dma_chan =
1808                         dma_request_channel(dma_mask, ntb_dma_filter_fn,
1809                                             (void *)(unsigned long)node);
1810                 if (!qp->tx_dma_chan)
1811                         dev_info(&pdev->dev, "Unable to allocate TX DMA channel\n");
1812
1813                 qp->rx_dma_chan =
1814                         dma_request_channel(dma_mask, ntb_dma_filter_fn,
1815                                             (void *)(unsigned long)node);
1816                 if (!qp->rx_dma_chan)
1817                         dev_info(&pdev->dev, "Unable to allocate RX DMA channel\n");
1818         } else {
1819                 qp->tx_dma_chan = NULL;
1820                 qp->rx_dma_chan = NULL;
1821         }
1822
1823         dev_dbg(&pdev->dev, "Using %s memcpy for TX\n",
1824                 qp->tx_dma_chan ? "DMA" : "CPU");
1825
1826         dev_dbg(&pdev->dev, "Using %s memcpy for RX\n",
1827                 qp->rx_dma_chan ? "DMA" : "CPU");
1828
1829         for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
1830                 entry = kzalloc_node(sizeof(*entry), GFP_ATOMIC, node);
1831                 if (!entry)
1832                         goto err1;
1833
1834                 entry->qp = qp;
1835                 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry,
1836                              &qp->rx_free_q);
1837         }
1838         qp->rx_alloc_entry = NTB_QP_DEF_NUM_ENTRIES;
1839
1840         for (i = 0; i < qp->tx_max_entry; i++) {
1841                 entry = kzalloc_node(sizeof(*entry), GFP_ATOMIC, node);
1842                 if (!entry)
1843                         goto err2;
1844
1845                 entry->qp = qp;
1846                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1847                              &qp->tx_free_q);
1848         }
1849
1850         ntb_db_clear(qp->ndev, qp_bit);
1851         ntb_db_clear_mask(qp->ndev, qp_bit);
1852
1853         dev_info(&pdev->dev, "NTB Transport QP %d created\n", qp->qp_num);
1854
1855         return qp;
1856
1857 err2:
1858         while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1859                 kfree(entry);
1860 err1:
1861         qp->rx_alloc_entry = 0;
1862         while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
1863                 kfree(entry);
1864         if (qp->tx_dma_chan)
1865                 dma_release_channel(qp->tx_dma_chan);
1866         if (qp->rx_dma_chan)
1867                 dma_release_channel(qp->rx_dma_chan);
1868         nt->qp_bitmap_free |= qp_bit;
1869 err:
1870         return NULL;
1871 }
1872 EXPORT_SYMBOL_GPL(ntb_transport_create_queue);
1873
1874 /**
1875  * ntb_transport_free_queue - Frees NTB transport queue
1876  * @qp: NTB queue to be freed
1877  *
1878  * Frees NTB transport queue
1879  */
1880 void ntb_transport_free_queue(struct ntb_transport_qp *qp)
1881 {
1882         struct pci_dev *pdev;
1883         struct ntb_queue_entry *entry;
1884         u64 qp_bit;
1885
1886         if (!qp)
1887                 return;
1888
1889         pdev = qp->ndev->pdev;
1890
1891         qp->active = false;
1892
1893         if (qp->tx_dma_chan) {
1894                 struct dma_chan *chan = qp->tx_dma_chan;
1895                 /* Putting the dma_chan to NULL will force any new traffic to be
1896                  * processed by the CPU instead of the DAM engine
1897                  */
1898                 qp->tx_dma_chan = NULL;
1899
1900                 /* Try to be nice and wait for any queued DMA engine
1901                  * transactions to process before smashing it with a rock
1902                  */
1903                 dma_sync_wait(chan, qp->last_cookie);
1904                 dmaengine_terminate_all(chan);
1905                 dma_release_channel(chan);
1906         }
1907
1908         if (qp->rx_dma_chan) {
1909                 struct dma_chan *chan = qp->rx_dma_chan;
1910                 /* Putting the dma_chan to NULL will force any new traffic to be
1911                  * processed by the CPU instead of the DAM engine
1912                  */
1913                 qp->rx_dma_chan = NULL;
1914
1915                 /* Try to be nice and wait for any queued DMA engine
1916                  * transactions to process before smashing it with a rock
1917                  */
1918                 dma_sync_wait(chan, qp->last_cookie);
1919                 dmaengine_terminate_all(chan);
1920                 dma_release_channel(chan);
1921         }
1922
1923         qp_bit = BIT_ULL(qp->qp_num);
1924
1925         ntb_db_set_mask(qp->ndev, qp_bit);
1926         tasklet_kill(&qp->rxc_db_work);
1927
1928         cancel_delayed_work_sync(&qp->link_work);
1929
1930         qp->cb_data = NULL;
1931         qp->rx_handler = NULL;
1932         qp->tx_handler = NULL;
1933         qp->event_handler = NULL;
1934
1935         while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
1936                 kfree(entry);
1937
1938         while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_pend_q))) {
1939                 dev_warn(&pdev->dev, "Freeing item from non-empty rx_pend_q\n");
1940                 kfree(entry);
1941         }
1942
1943         while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_post_q))) {
1944                 dev_warn(&pdev->dev, "Freeing item from non-empty rx_post_q\n");
1945                 kfree(entry);
1946         }
1947
1948         while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1949                 kfree(entry);
1950
1951         qp->transport->qp_bitmap_free |= qp_bit;
1952
1953         dev_info(&pdev->dev, "NTB Transport QP %d freed\n", qp->qp_num);
1954 }
1955 EXPORT_SYMBOL_GPL(ntb_transport_free_queue);
1956
1957 /**
1958  * ntb_transport_rx_remove - Dequeues enqueued rx packet
1959  * @qp: NTB queue to be freed
1960  * @len: pointer to variable to write enqueued buffers length
1961  *
1962  * Dequeues unused buffers from receive queue.  Should only be used during
1963  * shutdown of qp.
1964  *
1965  * RETURNS: NULL error value on error, or void* for success.
1966  */
1967 void *ntb_transport_rx_remove(struct ntb_transport_qp *qp, unsigned int *len)
1968 {
1969         struct ntb_queue_entry *entry;
1970         void *buf;
1971
1972         if (!qp || qp->client_ready)
1973                 return NULL;
1974
1975         entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_pend_q);
1976         if (!entry)
1977                 return NULL;
1978
1979         buf = entry->cb_data;
1980         *len = entry->len;
1981
1982         ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_free_q);
1983
1984         return buf;
1985 }
1986 EXPORT_SYMBOL_GPL(ntb_transport_rx_remove);
1987
1988 /**
1989  * ntb_transport_rx_enqueue - Enqueue a new NTB queue entry
1990  * @qp: NTB transport layer queue the entry is to be enqueued on
1991  * @cb: per buffer pointer for callback function to use
1992  * @data: pointer to data buffer that incoming packets will be copied into
1993  * @len: length of the data buffer
1994  *
1995  * Enqueue a new receive buffer onto the transport queue into which a NTB
1996  * payload can be received into.
1997  *
1998  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
1999  */
2000 int ntb_transport_rx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
2001                              unsigned int len)
2002 {
2003         struct ntb_queue_entry *entry;
2004
2005         if (!qp)
2006                 return -EINVAL;
2007
2008         entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q);
2009         if (!entry)
2010                 return -ENOMEM;
2011
2012         entry->cb_data = cb;
2013         entry->buf = data;
2014         entry->len = len;
2015         entry->flags = 0;
2016         entry->retries = 0;
2017         entry->errors = 0;
2018         entry->rx_index = 0;
2019
2020         ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_pend_q);
2021
2022         if (qp->active)
2023                 tasklet_schedule(&qp->rxc_db_work);
2024
2025         return 0;
2026 }
2027 EXPORT_SYMBOL_GPL(ntb_transport_rx_enqueue);
2028
2029 /**
2030  * ntb_transport_tx_enqueue - Enqueue a new NTB queue entry
2031  * @qp: NTB transport layer queue the entry is to be enqueued on
2032  * @cb: per buffer pointer for callback function to use
2033  * @data: pointer to data buffer that will be sent
2034  * @len: length of the data buffer
2035  *
2036  * Enqueue a new transmit buffer onto the transport queue from which a NTB
2037  * payload will be transmitted.  This assumes that a lock is being held to
2038  * serialize access to the qp.
2039  *
2040  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
2041  */
2042 int ntb_transport_tx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
2043                              unsigned int len)
2044 {
2045         struct ntb_queue_entry *entry;
2046         int rc;
2047
2048         if (!qp || !qp->link_is_up || !len)
2049                 return -EINVAL;
2050
2051         entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
2052         if (!entry) {
2053                 qp->tx_err_no_buf++;
2054                 return -EBUSY;
2055         }
2056
2057         entry->cb_data = cb;
2058         entry->buf = data;
2059         entry->len = len;
2060         entry->flags = 0;
2061         entry->errors = 0;
2062         entry->retries = 0;
2063         entry->tx_index = 0;
2064
2065         rc = ntb_process_tx(qp, entry);
2066         if (rc)
2067                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
2068                              &qp->tx_free_q);
2069
2070         return rc;
2071 }
2072 EXPORT_SYMBOL_GPL(ntb_transport_tx_enqueue);
2073
2074 /**
2075  * ntb_transport_link_up - Notify NTB transport of client readiness to use queue
2076  * @qp: NTB transport layer queue to be enabled
2077  *
2078  * Notify NTB transport layer of client readiness to use queue
2079  */
2080 void ntb_transport_link_up(struct ntb_transport_qp *qp)
2081 {
2082         if (!qp)
2083                 return;
2084
2085         qp->client_ready = true;
2086
2087         if (qp->transport->link_is_up)
2088                 schedule_delayed_work(&qp->link_work, 0);
2089 }
2090 EXPORT_SYMBOL_GPL(ntb_transport_link_up);
2091
2092 /**
2093  * ntb_transport_link_down - Notify NTB transport to no longer enqueue data
2094  * @qp: NTB transport layer queue to be disabled
2095  *
2096  * Notify NTB transport layer of client's desire to no longer receive data on
2097  * transport queue specified.  It is the client's responsibility to ensure all
2098  * entries on queue are purged or otherwise handled appropriately.
2099  */
2100 void ntb_transport_link_down(struct ntb_transport_qp *qp)
2101 {
2102         int val;
2103
2104         if (!qp)
2105                 return;
2106
2107         qp->client_ready = false;
2108
2109         val = ntb_spad_read(qp->ndev, QP_LINKS);
2110
2111         ntb_peer_spad_write(qp->ndev, PIDX, QP_LINKS, val & ~BIT(qp->qp_num));
2112
2113         if (qp->link_is_up)
2114                 ntb_send_link_down(qp);
2115         else
2116                 cancel_delayed_work_sync(&qp->link_work);
2117 }
2118 EXPORT_SYMBOL_GPL(ntb_transport_link_down);
2119
2120 /**
2121  * ntb_transport_link_query - Query transport link state
2122  * @qp: NTB transport layer queue to be queried
2123  *
2124  * Query connectivity to the remote system of the NTB transport queue
2125  *
2126  * RETURNS: true for link up or false for link down
2127  */
2128 bool ntb_transport_link_query(struct ntb_transport_qp *qp)
2129 {
2130         if (!qp)
2131                 return false;
2132
2133         return qp->link_is_up;
2134 }
2135 EXPORT_SYMBOL_GPL(ntb_transport_link_query);
2136
2137 /**
2138  * ntb_transport_qp_num - Query the qp number
2139  * @qp: NTB transport layer queue to be queried
2140  *
2141  * Query qp number of the NTB transport queue
2142  *
2143  * RETURNS: a zero based number specifying the qp number
2144  */
2145 unsigned char ntb_transport_qp_num(struct ntb_transport_qp *qp)
2146 {
2147         if (!qp)
2148                 return 0;
2149
2150         return qp->qp_num;
2151 }
2152 EXPORT_SYMBOL_GPL(ntb_transport_qp_num);
2153
2154 /**
2155  * ntb_transport_max_size - Query the max payload size of a qp
2156  * @qp: NTB transport layer queue to be queried
2157  *
2158  * Query the maximum payload size permissible on the given qp
2159  *
2160  * RETURNS: the max payload size of a qp
2161  */
2162 unsigned int ntb_transport_max_size(struct ntb_transport_qp *qp)
2163 {
2164         unsigned int max_size;
2165         unsigned int copy_align;
2166         struct dma_chan *rx_chan, *tx_chan;
2167
2168         if (!qp)
2169                 return 0;
2170
2171         rx_chan = qp->rx_dma_chan;
2172         tx_chan = qp->tx_dma_chan;
2173
2174         copy_align = max(rx_chan ? rx_chan->device->copy_align : 0,
2175                          tx_chan ? tx_chan->device->copy_align : 0);
2176
2177         /* If DMA engine usage is possible, try to find the max size for that */
2178         max_size = qp->tx_max_frame - sizeof(struct ntb_payload_header);
2179         max_size = round_down(max_size, 1 << copy_align);
2180
2181         return max_size;
2182 }
2183 EXPORT_SYMBOL_GPL(ntb_transport_max_size);
2184
2185 unsigned int ntb_transport_tx_free_entry(struct ntb_transport_qp *qp)
2186 {
2187         unsigned int head = qp->tx_index;
2188         unsigned int tail = qp->remote_rx_info->entry;
2189
2190         return tail > head ? tail - head : qp->tx_max_entry + tail - head;
2191 }
2192 EXPORT_SYMBOL_GPL(ntb_transport_tx_free_entry);
2193
2194 static void ntb_transport_doorbell_callback(void *data, int vector)
2195 {
2196         struct ntb_transport_ctx *nt = data;
2197         struct ntb_transport_qp *qp;
2198         u64 db_bits;
2199         unsigned int qp_num;
2200
2201         db_bits = (nt->qp_bitmap & ~nt->qp_bitmap_free &
2202                    ntb_db_vector_mask(nt->ndev, vector));
2203
2204         while (db_bits) {
2205                 qp_num = __ffs(db_bits);
2206                 qp = &nt->qp_vec[qp_num];
2207
2208                 if (qp->active)
2209                         tasklet_schedule(&qp->rxc_db_work);
2210
2211                 db_bits &= ~BIT_ULL(qp_num);
2212         }
2213 }
2214
2215 static const struct ntb_ctx_ops ntb_transport_ops = {
2216         .link_event = ntb_transport_event_callback,
2217         .db_event = ntb_transport_doorbell_callback,
2218 };
2219
2220 static struct ntb_client ntb_transport_client = {
2221         .ops = {
2222                 .probe = ntb_transport_probe,
2223                 .remove = ntb_transport_free,
2224         },
2225 };
2226
2227 static int __init ntb_transport_init(void)
2228 {
2229         int rc;
2230
2231         pr_info("%s, version %s\n", NTB_TRANSPORT_DESC, NTB_TRANSPORT_VER);
2232
2233         if (debugfs_initialized())
2234                 nt_debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
2235
2236         rc = bus_register(&ntb_transport_bus);
2237         if (rc)
2238                 goto err_bus;
2239
2240         rc = ntb_register_client(&ntb_transport_client);
2241         if (rc)
2242                 goto err_client;
2243
2244         return 0;
2245
2246 err_client:
2247         bus_unregister(&ntb_transport_bus);
2248 err_bus:
2249         debugfs_remove_recursive(nt_debugfs_dir);
2250         return rc;
2251 }
2252 module_init(ntb_transport_init);
2253
2254 static void __exit ntb_transport_exit(void)
2255 {
2256         ntb_unregister_client(&ntb_transport_client);
2257         bus_unregister(&ntb_transport_bus);
2258         debugfs_remove_recursive(nt_debugfs_dir);
2259 }
2260 module_exit(ntb_transport_exit);