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 struct ntb_queue_entry {
  99         /* ntb_queue list reference */
 100         struct list_head entry;
 101         /* pointers to data to be transferred */
 102         void *cb_data;
 103         void *buf;
 104         unsigned int len;
 105         unsigned int flags;
 106         int retries;
 107         int errors;
 108         unsigned int tx_index;
 109         unsigned int rx_index;
 110
 111         struct ntb_transport_qp *qp;
 112         union {
 113                 struct ntb_payload_header __iomem *tx_hdr;
 114                 struct ntb_payload_header *rx_hdr;
 115         };
 116 };
 117
 118 struct ntb_rx_info {
 119         unsigned int entry;
 120 };
 121
 122 struct ntb_transport_qp {
 123         struct ntb_transport_ctx *transport;
 124         struct ntb_dev *ndev;
 125         void *cb_data;
 126         struct dma_chan *tx_dma_chan;
 127         struct dma_chan *rx_dma_chan;
 128
 129         bool client_ready;
 130         bool link_is_up;
 131         bool active;
 132
 133         u8 qp_num;      /* Only 64 QP's are allowed.  0-63 */
 134         u64 qp_bit;
 135
 136         struct ntb_rx_info __iomem *rx_info;
 137         struct ntb_rx_info *remote_rx_info;
 138
 139         void (*tx_handler)(struct ntb_transport_qp *qp, void *qp_data,
 140                            void *data, int len);
 141         struct list_head tx_free_q;
 142         spinlock_t ntb_tx_free_q_lock;
 143         void __iomem *tx_mw;
 144         dma_addr_t tx_mw_phys;
 145         unsigned int tx_index;
 146         unsigned int tx_max_entry;
 147         unsigned int tx_max_frame;
 148
 149         void (*rx_handler)(struct ntb_transport_qp *qp, void *qp_data,
 150                            void *data, int len);
 151         struct list_head rx_post_q;
 152         struct list_head rx_pend_q;
 153         struct list_head rx_free_q;
 154         /* ntb_rx_q_lock: synchronize access to rx_XXXX_q */
 155         spinlock_t ntb_rx_q_lock;
 156         void *rx_buff;
 157         unsigned int rx_index;
 158         unsigned int rx_max_entry;
 159         unsigned int rx_max_frame;
 160         unsigned int rx_alloc_entry;
 161         dma_cookie_t last_cookie;
 162         struct tasklet_struct rxc_db_work;
 163
 164         void (*event_handler)(void *data, int status);
 165         struct delayed_work link_work;
 166         struct work_struct link_cleanup;
 167
 168         struct dentry *debugfs_dir;
 169         struct dentry *debugfs_stats;
 170
 171         /* Stats */
 172         u64 rx_bytes;
 173         u64 rx_pkts;
 174         u64 rx_ring_empty;
 175         u64 rx_err_no_buf;
 176         u64 rx_err_oflow;
 177         u64 rx_err_ver;
 178         u64 rx_memcpy;
 179         u64 rx_async;
 180         u64 dma_rx_prep_err;
 181         u64 tx_bytes;
 182         u64 tx_pkts;
 183         u64 tx_ring_full;
 184         u64 tx_err_no_buf;
 185         u64 tx_memcpy;
 186         u64 tx_async;
 187         u64 dma_tx_prep_err;
 188 };
 189
 190 struct ntb_transport_mw {
 191         phys_addr_t phys_addr;
 192         resource_size_t phys_size;
 193         resource_size_t xlat_align;
 194         resource_size_t xlat_align_size;
 195         void __iomem *vbase;
 196         size_t xlat_size;
 197         size_t buff_size;
 198         void *virt_addr;
 199         dma_addr_t dma_addr;
 200 };
 201
 202 struct ntb_transport_client_dev {
 203         struct list_head entry;
 204         struct ntb_transport_ctx *nt;
 205         struct device dev;
 206 };
 207
 208 struct ntb_transport_ctx {
 209         struct list_head entry;
 210         struct list_head client_devs;
 211
 212         struct ntb_dev *ndev;
 213
 214         struct ntb_transport_mw *mw_vec;
 215         struct ntb_transport_qp *qp_vec;
 216         unsigned int mw_count;
 217         unsigned int qp_count;
 218         u64 qp_bitmap;
 219         u64 qp_bitmap_free;
 220
 221         bool link_is_up;
 222         struct delayed_work link_work;
 223         struct work_struct link_cleanup;
 224
 225         struct dentry *debugfs_node_dir;
 226 };
 227
 228 enum {
 229         DESC_DONE_FLAG = BIT(0),
 230         LINK_DOWN_FLAG = BIT(1),
 231 };
 232
 233 struct ntb_payload_header {
 234         unsigned int ver;
 235         unsigned int len;
 236         unsigned int flags;
 237 };
 238
 239 enum {
 240         VERSION = 0,
 241         QP_LINKS,
 242         NUM_QPS,
 243         NUM_MWS,
 244         MW0_SZ_HIGH,
 245         MW0_SZ_LOW,
 246 };
 247
 248 #define dev_client_dev(__dev) \
 249         container_of((__dev), struct ntb_transport_client_dev, dev)
 250
 251 #define drv_client(__drv) \
 252         container_of((__drv), struct ntb_transport_client, driver)
 253
 254 #define QP_TO_MW(nt, qp)        ((qp) % nt->mw_count)
 255 #define NTB_QP_DEF_NUM_ENTRIES  100
 256 #define NTB_LINK_DOWN_TIMEOUT   10
 257 #define DMA_RETRIES             20
 258 #define DMA_OUT_RESOURCE_TO     msecs_to_jiffies(50)
 259
 260 static void ntb_transport_rxc_db(unsigned long data);
 261 static const struct ntb_ctx_ops ntb_transport_ops;
 262 static struct ntb_client ntb_transport_client;
 263 static int ntb_async_tx_submit(struct ntb_transport_qp *qp,
 264                                struct ntb_queue_entry *entry);
 265 static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset);
 266 static int ntb_async_rx_submit(struct ntb_queue_entry *entry, void *offset);
 267 static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void *offset);
 268
 269
 270 static int ntb_transport_bus_match(struct device *dev,
 271                                    struct device_driver *drv)
 272 {
 273         return !strncmp(dev_name(dev), drv->name, strlen(drv->name));
 274 }
 275
 276 static int ntb_transport_bus_probe(struct device *dev)
 277 {
 278         const struct ntb_transport_client *client;
 279         int rc = -EINVAL;
 280
 281         get_device(dev);
 282
 283         client = drv_client(dev->driver);
 284         rc = client->probe(dev);
 285         if (rc)
 286                 put_device(dev);
 287
 288         return rc;
 289 }
 290
 291 static int ntb_transport_bus_remove(struct device *dev)
 292 {
 293         const struct ntb_transport_client *client;
 294
 295         client = drv_client(dev->driver);
 296         client->remove(dev);
 297
 298         put_device(dev);
 299
 300         return 0;
 301 }
 302
 303 static struct bus_type ntb_transport_bus = {
 304         .name = "ntb_transport",
 305         .match = ntb_transport_bus_match,
 306         .probe = ntb_transport_bus_probe,
 307         .remove = ntb_transport_bus_remove,
 308 };
 309
 310 static LIST_HEAD(ntb_transport_list);
 311
 312 static int ntb_bus_init(struct ntb_transport_ctx *nt)
 313 {
 314         list_add_tail(&nt->entry, &ntb_transport_list);
 315         return 0;
 316 }
 317
 318 static void ntb_bus_remove(struct ntb_transport_ctx *nt)
 319 {
 320         struct ntb_transport_client_dev *client_dev, *cd;
 321
 322         list_for_each_entry_safe(client_dev, cd, &nt->client_devs, entry) {
 323                 dev_err(client_dev->dev.parent, "%s still attached to bus, removing\n",
 324                         dev_name(&client_dev->dev));
 325                 list_del(&client_dev->entry);
 326                 device_unregister(&client_dev->dev);
 327         }
 328
 329         list_del(&nt->entry);
 330 }
 331
 332 static void ntb_transport_client_release(struct device *dev)
 333 {
 334         struct ntb_transport_client_dev *client_dev;
 335
 336         client_dev = dev_client_dev(dev);
 337         kfree(client_dev);
 338 }
 339
 340 /**
 341  * ntb_transport_unregister_client_dev - Unregister NTB client device
 342  * @device_name: Name of NTB client device
 343  *
 344  * Unregister an NTB client device with the NTB transport layer
 345  */
 346 void ntb_transport_unregister_client_dev(char *device_name)
 347 {
 348         struct ntb_transport_client_dev *client, *cd;
 349         struct ntb_transport_ctx *nt;
 350
 351         list_for_each_entry(nt, &ntb_transport_list, entry)
 352                 list_for_each_entry_safe(client, cd, &nt->client_devs, entry)
 353                         if (!strncmp(dev_name(&client->dev), device_name,
 354                                      strlen(device_name))) {
 355                                 list_del(&client->entry);
 356                                 device_unregister(&client->dev);
 357                         }
 358 }
 359 EXPORT_SYMBOL_GPL(ntb_transport_unregister_client_dev);
 360
 361 /**
 362  * ntb_transport_register_client_dev - Register NTB client device
 363  * @device_name: Name of NTB client device
 364  *
 365  * Register an NTB client device with the NTB transport layer
 366  */
 367 int ntb_transport_register_client_dev(char *device_name)
 368 {
 369         struct ntb_transport_client_dev *client_dev;
 370         struct ntb_transport_ctx *nt;
 371         int node;
 372         int rc, i = 0;
 373
 374         if (list_empty(&ntb_transport_list))
 375                 return -ENODEV;
 376
 377         list_for_each_entry(nt, &ntb_transport_list, entry) {
 378                 struct device *dev;
 379
 380                 node = dev_to_node(&nt->ndev->dev);
 381
 382                 client_dev = kzalloc_node(sizeof(*client_dev),
 383                                           GFP_KERNEL, node);
 384                 if (!client_dev) {
 385                         rc = -ENOMEM;
 386                         goto err;
 387                 }
 388
 389                 dev = &client_dev->dev;
 390
 391                 /* setup and register client devices */
 392                 dev_set_name(dev, "%s%d", device_name, i);
 393                 dev->bus = &ntb_transport_bus;
 394                 dev->release = ntb_transport_client_release;
 395                 dev->parent = &nt->ndev->dev;
 396
 397                 rc = device_register(dev);
 398                 if (rc) {
 399                         kfree(client_dev);
 400                         goto err;
 401                 }
 402
 403                 list_add_tail(&client_dev->entry, &nt->client_devs);
 404                 i++;
 405         }
 406
 407         return 0;
 408
 409 err:
 410         ntb_transport_unregister_client_dev(device_name);
 411
 412         return rc;
 413 }
 414 EXPORT_SYMBOL_GPL(ntb_transport_register_client_dev);
 415
 416 /**
 417  * ntb_transport_register_client - Register NTB client driver
 418  * @drv: NTB client driver to be registered
 419  *
 420  * Register an NTB client driver with the NTB transport layer
 421  *
 422  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 423  */
 424 int ntb_transport_register_client(struct ntb_transport_client *drv)
 425 {
 426         drv->driver.bus = &ntb_transport_bus;
 427
 428         if (list_empty(&ntb_transport_list))
 429                 return -ENODEV;
 430
 431         return driver_register(&drv->driver);
 432 }
 433 EXPORT_SYMBOL_GPL(ntb_transport_register_client);
 434
 435 /**
 436  * ntb_transport_unregister_client - Unregister NTB client driver
 437  * @drv: NTB client driver to be unregistered
 438  *
 439  * Unregister an NTB client driver with the NTB transport layer
 440  *
 441  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 442  */
 443 void ntb_transport_unregister_client(struct ntb_transport_client *drv)
 444 {
 445         driver_unregister(&drv->driver);
 446 }
 447 EXPORT_SYMBOL_GPL(ntb_transport_unregister_client);
 448
 449 static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count,
 450                             loff_t *offp)
 451 {
 452         struct ntb_transport_qp *qp;
 453         char *buf;
 454         ssize_t ret, out_offset, out_count;
 455
 456         qp = filp->private_data;
 457
 458         if (!qp || !qp->link_is_up)
 459                 return 0;
 460
 461         out_count = 1000;
 462
 463         buf = kmalloc(out_count, GFP_KERNEL);
 464         if (!buf)
 465                 return -ENOMEM;
 466
 467         out_offset = 0;
 468         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 469                                "\nNTB QP stats:\n\n");
 470         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 471                                "rx_bytes - \t%llu\n", qp->rx_bytes);
 472         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 473                                "rx_pkts - \t%llu\n", qp->rx_pkts);
 474         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 475                                "rx_memcpy - \t%llu\n", qp->rx_memcpy);
 476         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 477                                "rx_async - \t%llu\n", qp->rx_async);
 478         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 479                                "rx_ring_empty - %llu\n", qp->rx_ring_empty);
 480         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 481                                "rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
 482         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 483                                "rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
 484         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 485                                "rx_err_ver - \t%llu\n", qp->rx_err_ver);
 486         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 487                                "rx_buff - \t0x%p\n", qp->rx_buff);
 488         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 489                                "rx_index - \t%u\n", qp->rx_index);
 490         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 491                                "rx_max_entry - \t%u\n", qp->rx_max_entry);
 492         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 493                                "rx_alloc_entry - \t%u\n\n", qp->rx_alloc_entry);
 494
 495         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 496                                "tx_bytes - \t%llu\n", qp->tx_bytes);
 497         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 498                                "tx_pkts - \t%llu\n", qp->tx_pkts);
 499         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 500                                "tx_memcpy - \t%llu\n", qp->tx_memcpy);
 501         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 502                                "tx_async - \t%llu\n", qp->tx_async);
 503         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 504                                "tx_ring_full - \t%llu\n", qp->tx_ring_full);
 505         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 506                                "tx_err_no_buf - %llu\n", qp->tx_err_no_buf);
 507         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 508                                "tx_mw - \t0x%p\n", qp->tx_mw);
 509         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 510                                "tx_index (H) - \t%u\n", qp->tx_index);
 511         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 512                                "RRI (T) - \t%u\n",
 513                                qp->remote_rx_info->entry);
 514         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 515                                "tx_max_entry - \t%u\n", qp->tx_max_entry);
 516         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 517                                "free tx - \t%u\n",
 518                                ntb_transport_tx_free_entry(qp));
 519         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 520                                "DMA tx prep err - \t%llu\n",
 521                                qp->dma_tx_prep_err);
 522         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 523                                "DMA rx prep err - \t%llu\n",
 524                                qp->dma_rx_prep_err);
 525
 526         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 527                                "\n");
 528         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 529                                "Using TX DMA - \t%s\n",
 530                                qp->tx_dma_chan ? "Yes" : "No");
 531         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 532                                "Using RX DMA - \t%s\n",
 533                                qp->rx_dma_chan ? "Yes" : "No");
 534         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 535                                "QP Link - \t%s\n",
 536                                qp->link_is_up ? "Up" : "Down");
 537         out_offset += snprintf(buf + out_offset, out_count - out_offset,
 538                                "\n");
 539
 540         if (out_offset > out_count)
 541                 out_offset = out_count;
 542
 543         ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
 544         kfree(buf);
 545         return ret;
 546 }
 547
 548 static const struct file_operations ntb_qp_debugfs_stats = {
 549         .owner = THIS_MODULE,
 550         .open = simple_open,
 551         .read = debugfs_read,
 552 };
 553
 554 static void ntb_list_add(spinlock_t *lock, struct list_head *entry,
 555                          struct list_head *list)
 556 {
 557         unsigned long flags;
 558
 559         spin_lock_irqsave(lock, flags);
 560         list_add_tail(entry, list);
 561         spin_unlock_irqrestore(lock, flags);
 562 }
 563
 564 static struct ntb_queue_entry *ntb_list_rm(spinlock_t *lock,
 565                                            struct list_head *list)
 566 {
 567         struct ntb_queue_entry *entry;
 568         unsigned long flags;
 569
 570         spin_lock_irqsave(lock, flags);
 571         if (list_empty(list)) {
 572                 entry = NULL;
 573                 goto out;
 574         }
 575         entry = list_first_entry(list, struct ntb_queue_entry, entry);
 576         list_del(&entry->entry);
 577
 578 out:
 579         spin_unlock_irqrestore(lock, flags);
 580
 581         return entry;
 582 }
 583
 584 static struct ntb_queue_entry *ntb_list_mv(spinlock_t *lock,
 585                                            struct list_head *list,
 586                                            struct list_head *to_list)
 587 {
 588         struct ntb_queue_entry *entry;
 589         unsigned long flags;
 590
 591         spin_lock_irqsave(lock, flags);
 592
 593         if (list_empty(list)) {
 594                 entry = NULL;
 595         } else {
 596                 entry = list_first_entry(list, struct ntb_queue_entry, entry);
 597                 list_move_tail(&entry->entry, to_list);
 598         }
 599
 600         spin_unlock_irqrestore(lock, flags);
 601
 602         return entry;
 603 }
 604
 605 static int ntb_transport_setup_qp_mw(struct ntb_transport_ctx *nt,
 606                                      unsigned int qp_num)
 607 {
 608         struct ntb_transport_qp *qp = &nt->qp_vec[qp_num];
 609         struct ntb_transport_mw *mw;
 610         struct ntb_dev *ndev = nt->ndev;
 611         struct ntb_queue_entry *entry;
 612         unsigned int rx_size, num_qps_mw;
 613         unsigned int mw_num, mw_count, qp_count;
 614         unsigned int i;
 615         int node;
 616
 617         mw_count = nt->mw_count;
 618         qp_count = nt->qp_count;
 619
 620         mw_num = QP_TO_MW(nt, qp_num);
 621         mw = &nt->mw_vec[mw_num];
 622
 623         if (!mw->virt_addr)
 624                 return -ENOMEM;
 625
 626         if (qp_count % mw_count && mw_num + 1 < qp_count / mw_count)
 627                 num_qps_mw = qp_count / mw_count + 1;
 628         else
 629                 num_qps_mw = qp_count / mw_count;
 630
 631         rx_size = (unsigned int)mw->xlat_size / num_qps_mw;
 632         qp->rx_buff = mw->virt_addr + rx_size * (qp_num / mw_count);
 633         rx_size -= sizeof(struct ntb_rx_info);
 634
 635         qp->remote_rx_info = qp->rx_buff + rx_size;
 636
 637         /* Due to housekeeping, there must be atleast 2 buffs */
 638         qp->rx_max_frame = min(transport_mtu, rx_size / 2);
 639         qp->rx_max_entry = rx_size / qp->rx_max_frame;
 640         qp->rx_index = 0;
 641
 642         /*
 643          * Checking to see if we have more entries than the default.
 644          * We should add additional entries if that is the case so we
 645          * can be in sync with the transport frames.
 646          */
 647         node = dev_to_node(&ndev->dev);
 648         for (i = qp->rx_alloc_entry; i < qp->rx_max_entry; i++) {
 649                 entry = kzalloc_node(sizeof(*entry), GFP_ATOMIC, node);
 650                 if (!entry)
 651                         return -ENOMEM;
 652
 653                 entry->qp = qp;
 654                 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry,
 655                              &qp->rx_free_q);
 656                 qp->rx_alloc_entry++;
 657         }
 658
 659         qp->remote_rx_info->entry = qp->rx_max_entry - 1;
 660
 661         /* setup the hdr offsets with 0's */
 662         for (i = 0; i < qp->rx_max_entry; i++) {
 663                 void *offset = (qp->rx_buff + qp->rx_max_frame * (i + 1) -
 664                                 sizeof(struct ntb_payload_header));
 665                 memset(offset, 0, sizeof(struct ntb_payload_header));
 666         }
 667
 668         qp->rx_pkts = 0;
 669         qp->tx_pkts = 0;
 670         qp->tx_index = 0;
 671
 672         return 0;
 673 }
 674
 675 static void ntb_free_mw(struct ntb_transport_ctx *nt, int num_mw)
 676 {
 677         struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
 678         struct pci_dev *pdev = nt->ndev->pdev;
 679
 680         if (!mw->virt_addr)
 681                 return;
 682
 683         ntb_mw_clear_trans(nt->ndev, num_mw);
 684         dma_free_coherent(&pdev->dev, mw->buff_size,
 685                           mw->virt_addr, mw->dma_addr);
 686         mw->xlat_size = 0;
 687         mw->buff_size = 0;
 688         mw->virt_addr = NULL;
 689 }
 690
 691 static int ntb_set_mw(struct ntb_transport_ctx *nt, int num_mw,
 692                       resource_size_t size)
 693 {
 694         struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
 695         struct pci_dev *pdev = nt->ndev->pdev;
 696         size_t xlat_size, buff_size;
 697         int rc;
 698
 699         if (!size)
 700                 return -EINVAL;
 701
 702         xlat_size = round_up(size, mw->xlat_align_size);
 703         buff_size = round_up(size, mw->xlat_align);
 704
 705         /* No need to re-setup */
 706         if (mw->xlat_size == xlat_size)
 707                 return 0;
 708
 709         if (mw->buff_size)
 710                 ntb_free_mw(nt, num_mw);
 711
 712         /* Alloc memory for receiving data.  Must be aligned */
 713         mw->xlat_size = xlat_size;
 714         mw->buff_size = buff_size;
 715
 716         mw->virt_addr = dma_alloc_coherent(&pdev->dev, buff_size,
 717                                            &mw->dma_addr, GFP_KERNEL);
 718         if (!mw->virt_addr) {
 719                 mw->xlat_size = 0;
 720                 mw->buff_size = 0;
 721                 dev_err(&pdev->dev, "Unable to alloc MW buff of size %zu\n",
 722                         buff_size);
 723                 return -ENOMEM;
 724         }
 725
 726         /*
 727          * we must ensure that the memory address allocated is BAR size
 728          * aligned in order for the XLAT register to take the value. This
 729          * is a requirement of the hardware. It is recommended to setup CMA
 730          * for BAR sizes equal or greater than 4MB.
 731          */
 732         if (!IS_ALIGNED(mw->dma_addr, mw->xlat_align)) {
 733                 dev_err(&pdev->dev, "DMA memory %pad is not aligned\n",
 734                         &mw->dma_addr);
 735                 ntb_free_mw(nt, num_mw);
 736                 return -ENOMEM;
 737         }
 738
 739         /* Notify HW the memory location of the receive buffer */
 740         rc = ntb_mw_set_trans(nt->ndev, num_mw, mw->dma_addr, mw->xlat_size);
 741         if (rc) {
 742                 dev_err(&pdev->dev, "Unable to set mw%d translation", num_mw);
 743                 ntb_free_mw(nt, num_mw);
 744                 return -EIO;
 745         }
 746
 747         return 0;
 748 }
 749
 750 static void ntb_qp_link_down_reset(struct ntb_transport_qp *qp)
 751 {
 752         qp->link_is_up = false;
 753         qp->active = false;
 754
 755         qp->tx_index = 0;
 756         qp->rx_index = 0;
 757         qp->rx_bytes = 0;
 758         qp->rx_pkts = 0;
 759         qp->rx_ring_empty = 0;
 760         qp->rx_err_no_buf = 0;
 761         qp->rx_err_oflow = 0;
 762         qp->rx_err_ver = 0;
 763         qp->rx_memcpy = 0;
 764         qp->rx_async = 0;
 765         qp->tx_bytes = 0;
 766         qp->tx_pkts = 0;
 767         qp->tx_ring_full = 0;
 768         qp->tx_err_no_buf = 0;
 769         qp->tx_memcpy = 0;
 770         qp->tx_async = 0;
 771         qp->dma_tx_prep_err = 0;
 772         qp->dma_rx_prep_err = 0;
 773 }
 774
 775 static void ntb_qp_link_cleanup(struct ntb_transport_qp *qp)
 776 {
 777         struct ntb_transport_ctx *nt = qp->transport;
 778         struct pci_dev *pdev = nt->ndev->pdev;
 779
 780         dev_info(&pdev->dev, "qp %d: Link Cleanup\n", qp->qp_num);
 781
 782         cancel_delayed_work_sync(&qp->link_work);
 783         ntb_qp_link_down_reset(qp);
 784
 785         if (qp->event_handler)
 786                 qp->event_handler(qp->cb_data, qp->link_is_up);
 787 }
 788
 789 static void ntb_qp_link_cleanup_work(struct work_struct *work)
 790 {
 791         struct ntb_transport_qp *qp = container_of(work,
 792                                                    struct ntb_transport_qp,
 793                                                    link_cleanup);
 794         struct ntb_transport_ctx *nt = qp->transport;
 795
 796         ntb_qp_link_cleanup(qp);
 797
 798         if (nt->link_is_up)
 799                 schedule_delayed_work(&qp->link_work,
 800                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 801 }
 802
 803 static void ntb_qp_link_down(struct ntb_transport_qp *qp)
 804 {
 805         schedule_work(&qp->link_cleanup);
 806 }
 807
 808 static void ntb_transport_link_cleanup(struct ntb_transport_ctx *nt)
 809 {
 810         struct ntb_transport_qp *qp;
 811         u64 qp_bitmap_alloc;
 812         unsigned int i, count;
 813
 814         qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
 815
 816         /* Pass along the info to any clients */
 817         for (i = 0; i < nt->qp_count; i++)
 818                 if (qp_bitmap_alloc & BIT_ULL(i)) {
 819                         qp = &nt->qp_vec[i];
 820                         ntb_qp_link_cleanup(qp);
 821                         cancel_work_sync(&qp->link_cleanup);
 822                         cancel_delayed_work_sync(&qp->link_work);
 823                 }
 824
 825         if (!nt->link_is_up)
 826                 cancel_delayed_work_sync(&nt->link_work);
 827
 828         /* The scratchpad registers keep the values if the remote side
 829          * goes down, blast them now to give them a sane value the next
 830          * time they are accessed
 831          */
 832         count = ntb_spad_count(nt->ndev);
 833         for (i = 0; i < count; i++)
 834                 ntb_spad_write(nt->ndev, i, 0);
 835 }
 836
 837 static void ntb_transport_link_cleanup_work(struct work_struct *work)
 838 {
 839         struct ntb_transport_ctx *nt =
 840                 container_of(work, struct ntb_transport_ctx, link_cleanup);
 841
 842         ntb_transport_link_cleanup(nt);
 843 }
 844
 845 static void ntb_transport_event_callback(void *data)
 846 {
 847         struct ntb_transport_ctx *nt = data;
 848
 849         if (ntb_link_is_up(nt->ndev, NULL, NULL) == 1)
 850                 schedule_delayed_work(&nt->link_work, 0);
 851         else
 852                 schedule_work(&nt->link_cleanup);
 853 }
 854
 855 static void ntb_transport_link_work(struct work_struct *work)
 856 {
 857         struct ntb_transport_ctx *nt =
 858                 container_of(work, struct ntb_transport_ctx, link_work.work);
 859         struct ntb_dev *ndev = nt->ndev;
 860         struct pci_dev *pdev = ndev->pdev;
 861         resource_size_t size;
 862         u32 val;
 863         int rc = 0, i, spad;
 864
 865         /* send the local info, in the opposite order of the way we read it */
 866         for (i = 0; i < nt->mw_count; i++) {
 867                 size = nt->mw_vec[i].phys_size;
 868
 869                 if (max_mw_size && size > max_mw_size)
 870                         size = max_mw_size;
 871
 872                 spad = MW0_SZ_HIGH + (i * 2);
 873                 ntb_peer_spad_write(ndev, spad, upper_32_bits(size));
 874
 875                 spad = MW0_SZ_LOW + (i * 2);
 876                 ntb_peer_spad_write(ndev, spad, lower_32_bits(size));
 877         }
 878
 879         ntb_peer_spad_write(ndev, NUM_MWS, nt->mw_count);
 880
 881         ntb_peer_spad_write(ndev, NUM_QPS, nt->qp_count);
 882
 883         ntb_peer_spad_write(ndev, VERSION, NTB_TRANSPORT_VERSION);
 884
 885         /* Query the remote side for its info */
 886         val = ntb_spad_read(ndev, VERSION);
 887         dev_dbg(&pdev->dev, "Remote version = %d\n", val);
 888         if (val != NTB_TRANSPORT_VERSION)
 889                 goto out;
 890
 891         val = ntb_spad_read(ndev, NUM_QPS);
 892         dev_dbg(&pdev->dev, "Remote max number of qps = %d\n", val);
 893         if (val != nt->qp_count)
 894                 goto out;
 895
 896         val = ntb_spad_read(ndev, NUM_MWS);
 897         dev_dbg(&pdev->dev, "Remote number of mws = %d\n", val);
 898         if (val != nt->mw_count)
 899                 goto out;
 900
 901         for (i = 0; i < nt->mw_count; i++) {
 902                 u64 val64;
 903
 904                 val = ntb_spad_read(ndev, MW0_SZ_HIGH + (i * 2));
 905                 val64 = (u64)val << 32;
 906
 907                 val = ntb_spad_read(ndev, MW0_SZ_LOW + (i * 2));
 908                 val64 |= val;
 909
 910                 dev_dbg(&pdev->dev, "Remote MW%d size = %#llx\n", i, val64);
 911
 912                 rc = ntb_set_mw(nt, i, val64);
 913                 if (rc)
 914                         goto out1;
 915         }
 916
 917         nt->link_is_up = true;
 918
 919         for (i = 0; i < nt->qp_count; i++) {
 920                 struct ntb_transport_qp *qp = &nt->qp_vec[i];
 921
 922                 ntb_transport_setup_qp_mw(nt, i);
 923
 924                 if (qp->client_ready)
 925                         schedule_delayed_work(&qp->link_work, 0);
 926         }
 927
 928         return;
 929
 930 out1:
 931         for (i = 0; i < nt->mw_count; i++)
 932                 ntb_free_mw(nt, i);
 933
 934         /* if there's an actual failure, we should just bail */
 935         if (rc < 0) {
 936                 ntb_link_disable(ndev);
 937                 return;
 938         }
 939
 940 out:
 941         if (ntb_link_is_up(ndev, NULL, NULL) == 1)
 942                 schedule_delayed_work(&nt->link_work,
 943                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 944 }
 945
 946 static void ntb_qp_link_work(struct work_struct *work)
 947 {
 948         struct ntb_transport_qp *qp = container_of(work,
 949                                                    struct ntb_transport_qp,
 950                                                    link_work.work);
 951         struct pci_dev *pdev = qp->ndev->pdev;
 952         struct ntb_transport_ctx *nt = qp->transport;
 953         int val;
 954
 955         WARN_ON(!nt->link_is_up);
 956
 957         val = ntb_spad_read(nt->ndev, QP_LINKS);
 958
 959         ntb_peer_spad_write(nt->ndev, QP_LINKS, val | BIT(qp->qp_num));
 960
 961         /* query remote spad for qp ready bits */
 962         dev_dbg_ratelimited(&pdev->dev, "Remote QP link status = %x\n", val);
 963
 964         /* See if the remote side is up */
 965         if (val & BIT(qp->qp_num)) {
 966                 dev_info(&pdev->dev, "qp %d: Link Up\n", qp->qp_num);
 967                 qp->link_is_up = true;
 968                 qp->active = true;
 969
 970                 if (qp->event_handler)
 971                         qp->event_handler(qp->cb_data, qp->link_is_up);
 972
 973                 if (qp->active)
 974                         tasklet_schedule(&qp->rxc_db_work);
 975         } else if (nt->link_is_up)
 976                 schedule_delayed_work(&qp->link_work,
 977                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 978 }
 979
 980 static int ntb_transport_init_queue(struct ntb_transport_ctx *nt,
 981                                     unsigned int qp_num)
 982 {
 983         struct ntb_transport_qp *qp;
 984         phys_addr_t mw_base;
 985         resource_size_t mw_size;
 986         unsigned int num_qps_mw, tx_size;
 987         unsigned int mw_num, mw_count, qp_count;
 988         u64 qp_offset;
 989
 990         mw_count = nt->mw_count;
 991         qp_count = nt->qp_count;
 992
 993         mw_num = QP_TO_MW(nt, qp_num);
 994
 995         qp = &nt->qp_vec[qp_num];
 996         qp->qp_num = qp_num;
 997         qp->transport = nt;
 998         qp->ndev = nt->ndev;
 999         qp->client_ready = false;
1000         qp->event_handler = NULL;
1001         ntb_qp_link_down_reset(qp);
1002
1003         if (qp_count % mw_count && mw_num + 1 < qp_count / mw_count)
1004                 num_qps_mw = qp_count / mw_count + 1;
1005         else
1006                 num_qps_mw = qp_count / mw_count;
1007
1008         mw_base = nt->mw_vec[mw_num].phys_addr;
1009         mw_size = nt->mw_vec[mw_num].phys_size;
1010
1011         tx_size = (unsigned int)mw_size / num_qps_mw;
1012         qp_offset = tx_size * (qp_num / mw_count);
1013
1014         qp->tx_mw = nt->mw_vec[mw_num].vbase + qp_offset;
1015         if (!qp->tx_mw)
1016                 return -EINVAL;
1017
1018         qp->tx_mw_phys = mw_base + qp_offset;
1019         if (!qp->tx_mw_phys)
1020                 return -EINVAL;
1021
1022         tx_size -= sizeof(struct ntb_rx_info);
1023         qp->rx_info = qp->tx_mw + tx_size;
1024
1025         /* Due to housekeeping, there must be atleast 2 buffs */
1026         qp->tx_max_frame = min(transport_mtu, tx_size / 2);
1027         qp->tx_max_entry = tx_size / qp->tx_max_frame;
1028
1029         if (nt->debugfs_node_dir) {
1030                 char debugfs_name[4];
1031
1032                 snprintf(debugfs_name, 4, "qp%d", qp_num);
1033                 qp->debugfs_dir = debugfs_create_dir(debugfs_name,
1034                                                      nt->debugfs_node_dir);
1035
1036                 qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR,
1037                                                         qp->debugfs_dir, qp,
1038                                                         &ntb_qp_debugfs_stats);
1039         } else {
1040                 qp->debugfs_dir = NULL;
1041                 qp->debugfs_stats = NULL;
1042         }
1043
1044         INIT_DELAYED_WORK(&qp->link_work, ntb_qp_link_work);
1045         INIT_WORK(&qp->link_cleanup, ntb_qp_link_cleanup_work);
1046
1047         spin_lock_init(&qp->ntb_rx_q_lock);
1048         spin_lock_init(&qp->ntb_tx_free_q_lock);
1049
1050         INIT_LIST_HEAD(&qp->rx_post_q);
1051         INIT_LIST_HEAD(&qp->rx_pend_q);
1052         INIT_LIST_HEAD(&qp->rx_free_q);
1053         INIT_LIST_HEAD(&qp->tx_free_q);
1054
1055         tasklet_init(&qp->rxc_db_work, ntb_transport_rxc_db,
1056                      (unsigned long)qp);
1057
1058         return 0;
1059 }
1060
1061 static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev)
1062 {
1063         struct ntb_transport_ctx *nt;
1064         struct ntb_transport_mw *mw;
1065         unsigned int mw_count, qp_count, spad_count, max_mw_count_for_spads;
1066         u64 qp_bitmap;
1067         int node;
1068         int rc, i;
1069
1070         mw_count = ntb_mw_count(ndev);
1071
1072         if (ntb_db_is_unsafe(ndev))
1073                 dev_dbg(&ndev->dev,
1074                         "doorbell is unsafe, proceed anyway...\n");
1075         if (ntb_spad_is_unsafe(ndev))
1076                 dev_dbg(&ndev->dev,
1077                         "scratchpad is unsafe, proceed anyway...\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_range(ndev, i, &mw->phys_addr, &mw->phys_size,
1110                                       &mw->xlat_align, &mw->xlat_align_size);
1111                 if (rc)
1112                         goto err1;
1113
1114                 mw->vbase = ioremap_wc(mw->phys_addr, mw->phys_size);
1115                 if (!mw->vbase) {
1116                         rc = -ENOMEM;
1117                         goto err1;
1118                 }
1119
1120                 mw->buff_size = 0;
1121                 mw->xlat_size = 0;
1122                 mw->virt_addr = NULL;
1123                 mw->dma_addr = 0;
1124         }
1125
1126         qp_bitmap = ntb_db_valid_mask(ndev);
1127
1128         qp_count = ilog2(qp_bitmap);
1129         if (max_num_clients && max_num_clients < qp_count)
1130                 qp_count = max_num_clients;
1131         else if (mw_count < qp_count)
1132                 qp_count = mw_count;
1133
1134         qp_bitmap &= BIT_ULL(qp_count) - 1;
1135
1136         nt->qp_count = qp_count;
1137         nt->qp_bitmap = qp_bitmap;
1138         nt->qp_bitmap_free = qp_bitmap;
1139
1140         nt->qp_vec = kzalloc_node(qp_count * sizeof(*nt->qp_vec),
1141                                   GFP_KERNEL, node);
1142         if (!nt->qp_vec) {
1143                 rc = -ENOMEM;
1144                 goto err1;
1145         }
1146
1147         if (nt_debugfs_dir) {
1148                 nt->debugfs_node_dir =
1149                         debugfs_create_dir(pci_name(ndev->pdev),
1150                                            nt_debugfs_dir);
1151         }
1152
1153         for (i = 0; i < qp_count; i++) {
1154                 rc = ntb_transport_init_queue(nt, i);
1155                 if (rc)
1156                         goto err2;
1157         }
1158
1159         INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work);
1160         INIT_WORK(&nt->link_cleanup, ntb_transport_link_cleanup_work);
1161
1162         rc = ntb_set_ctx(ndev, nt, &ntb_transport_ops);
1163         if (rc)
1164                 goto err2;
1165
1166         INIT_LIST_HEAD(&nt->client_devs);
1167         rc = ntb_bus_init(nt);
1168         if (rc)
1169                 goto err3;
1170
1171         nt->link_is_up = false;
1172         ntb_link_enable(ndev, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
1173         ntb_link_event(ndev);
1174
1175         return 0;
1176
1177 err3:
1178         ntb_clear_ctx(ndev);
1179 err2:
1180         kfree(nt->qp_vec);
1181 err1:
1182         while (i--) {
1183                 mw = &nt->mw_vec[i];
1184                 iounmap(mw->vbase);
1185         }
1186         kfree(nt->mw_vec);
1187 err:
1188         kfree(nt);
1189         return rc;
1190 }
1191
1192 static void ntb_transport_free(struct ntb_client *self, struct ntb_dev *ndev)
1193 {
1194         struct ntb_transport_ctx *nt = ndev->ctx;
1195         struct ntb_transport_qp *qp;
1196         u64 qp_bitmap_alloc;
1197         int i;
1198
1199         ntb_transport_link_cleanup(nt);
1200         cancel_work_sync(&nt->link_cleanup);
1201         cancel_delayed_work_sync(&nt->link_work);
1202
1203         qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
1204
1205         /* verify that all the qp's are freed */
1206         for (i = 0; i < nt->qp_count; i++) {
1207                 qp = &nt->qp_vec[i];
1208                 if (qp_bitmap_alloc & BIT_ULL(i))
1209                         ntb_transport_free_queue(qp);
1210                 debugfs_remove_recursive(qp->debugfs_dir);
1211         }
1212
1213         ntb_link_disable(ndev);
1214         ntb_clear_ctx(ndev);
1215
1216         ntb_bus_remove(nt);
1217
1218         for (i = nt->mw_count; i--; ) {
1219                 ntb_free_mw(nt, i);
1220                 iounmap(nt->mw_vec[i].vbase);
1221         }
1222
1223         kfree(nt->qp_vec);
1224         kfree(nt->mw_vec);
1225         kfree(nt);
1226 }
1227
1228 static void ntb_complete_rxc(struct ntb_transport_qp *qp)
1229 {
1230         struct ntb_queue_entry *entry;
1231         void *cb_data;
1232         unsigned int len;
1233         unsigned long irqflags;
1234
1235         spin_lock_irqsave(&qp->ntb_rx_q_lock, irqflags);
1236
1237         while (!list_empty(&qp->rx_post_q)) {
1238                 entry = list_first_entry(&qp->rx_post_q,
1239                                          struct ntb_queue_entry, entry);
1240                 if (!(entry->flags & DESC_DONE_FLAG))
1241                         break;
1242
1243                 entry->rx_hdr->flags = 0;
1244                 iowrite32(entry->rx_index, &qp->rx_info->entry);
1245
1246                 cb_data = entry->cb_data;
1247                 len = entry->len;
1248
1249                 list_move_tail(&entry->entry, &qp->rx_free_q);
1250
1251                 spin_unlock_irqrestore(&qp->ntb_rx_q_lock, irqflags);
1252
1253                 if (qp->rx_handler && qp->client_ready)
1254                         qp->rx_handler(qp, qp->cb_data, cb_data, len);
1255
1256                 spin_lock_irqsave(&qp->ntb_rx_q_lock, irqflags);
1257         }
1258
1259         spin_unlock_irqrestore(&qp->ntb_rx_q_lock, irqflags);
1260 }
1261
1262 static void ntb_rx_copy_callback(void *data,
1263                                  const struct dmaengine_result *res)
1264 {
1265         struct ntb_queue_entry *entry = data;
1266
1267         /* we need to check DMA results if we are using DMA */
1268         if (res) {
1269                 enum dmaengine_tx_result dma_err = res->result;
1270
1271                 switch (dma_err) {
1272                 case DMA_TRANS_READ_FAILED:
1273                 case DMA_TRANS_WRITE_FAILED:
1274                         entry->errors++;
1275                 case DMA_TRANS_ABORTED:
1276                 {
1277                         struct ntb_transport_qp *qp = entry->qp;
1278                         void *offset = qp->rx_buff + qp->rx_max_frame *
1279                                         qp->rx_index;
1280
1281                         ntb_memcpy_rx(entry, offset);
1282                         qp->rx_memcpy++;
1283                         return;
1284                 }
1285
1286                 case DMA_TRANS_NOERROR:
1287                 default:
1288                         break;
1289                 }
1290         }
1291
1292         entry->flags |= DESC_DONE_FLAG;
1293
1294         ntb_complete_rxc(entry->qp);
1295 }
1296
1297 static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void *offset)
1298 {
1299         void *buf = entry->buf;
1300         size_t len = entry->len;
1301
1302         memcpy(buf, offset, len);
1303
1304         /* Ensure that the data is fully copied out before clearing the flag */
1305         wmb();
1306
1307         ntb_rx_copy_callback(entry, NULL);
1308 }
1309
1310 static int ntb_async_rx_submit(struct ntb_queue_entry *entry, void *offset)
1311 {
1312         struct dma_async_tx_descriptor *txd;
1313         struct ntb_transport_qp *qp = entry->qp;
1314         struct dma_chan *chan = qp->rx_dma_chan;
1315         struct dma_device *device;
1316         size_t pay_off, buff_off, len;
1317         struct dmaengine_unmap_data *unmap;
1318         dma_cookie_t cookie;
1319         void *buf = entry->buf;
1320         int retries = 0;
1321
1322         len = entry->len;
1323         device = chan->device;
1324         pay_off = (size_t)offset & ~PAGE_MASK;
1325         buff_off = (size_t)buf & ~PAGE_MASK;
1326
1327         if (!is_dma_copy_aligned(device, pay_off, buff_off, len))
1328                 goto err;
1329
1330         unmap = dmaengine_get_unmap_data(device->dev, 2, GFP_NOWAIT);
1331         if (!unmap)
1332                 goto err;
1333
1334         unmap->len = len;
1335         unmap->addr[0] = dma_map_page(device->dev, virt_to_page(offset),
1336                                       pay_off, len, DMA_TO_DEVICE);
1337         if (dma_mapping_error(device->dev, unmap->addr[0]))
1338                 goto err_get_unmap;
1339
1340         unmap->to_cnt = 1;
1341
1342         unmap->addr[1] = dma_map_page(device->dev, virt_to_page(buf),
1343                                       buff_off, len, DMA_FROM_DEVICE);
1344         if (dma_mapping_error(device->dev, unmap->addr[1]))
1345                 goto err_get_unmap;
1346
1347         unmap->from_cnt = 1;
1348
1349         for (retries = 0; retries < DMA_RETRIES; retries++) {
1350                 txd = device->device_prep_dma_memcpy(chan,
1351                                                      unmap->addr[1],
1352                                                      unmap->addr[0], len,
1353                                                      DMA_PREP_INTERRUPT);
1354                 if (txd)
1355                         break;
1356
1357                 set_current_state(TASK_INTERRUPTIBLE);
1358                 schedule_timeout(DMA_OUT_RESOURCE_TO);
1359         }
1360
1361         if (!txd) {
1362                 qp->dma_rx_prep_err++;
1363                 goto err_get_unmap;
1364         }
1365
1366         txd->callback_result = ntb_rx_copy_callback;
1367         txd->callback_param = entry;
1368         dma_set_unmap(txd, unmap);
1369
1370         cookie = dmaengine_submit(txd);
1371         if (dma_submit_error(cookie))
1372                 goto err_set_unmap;
1373
1374         dmaengine_unmap_put(unmap);
1375
1376         qp->last_cookie = cookie;
1377
1378         qp->rx_async++;
1379
1380         return 0;
1381
1382 err_set_unmap:
1383         dmaengine_unmap_put(unmap);
1384 err_get_unmap:
1385         dmaengine_unmap_put(unmap);
1386 err:
1387         return -ENXIO;
1388 }
1389
1390 static void ntb_async_rx(struct ntb_queue_entry *entry, void *offset)
1391 {
1392         struct ntb_transport_qp *qp = entry->qp;
1393         struct dma_chan *chan = qp->rx_dma_chan;
1394         int res;
1395
1396         if (!chan)
1397                 goto err;
1398
1399         if (entry->len < copy_bytes)
1400                 goto err;
1401
1402         res = ntb_async_rx_submit(entry, offset);
1403         if (res < 0)
1404                 goto err;
1405
1406         if (!entry->retries)
1407                 qp->rx_async++;
1408
1409         return;
1410
1411 err:
1412         ntb_memcpy_rx(entry, offset);
1413         qp->rx_memcpy++;
1414 }
1415
1416 static int ntb_process_rxc(struct ntb_transport_qp *qp)
1417 {
1418         struct ntb_payload_header *hdr;
1419         struct ntb_queue_entry *entry;
1420         void *offset;
1421
1422         offset = qp->rx_buff + qp->rx_max_frame * qp->rx_index;
1423         hdr = offset + qp->rx_max_frame - sizeof(struct ntb_payload_header);
1424
1425         dev_dbg(&qp->ndev->pdev->dev, "qp %d: RX ver %u len %d flags %x\n",
1426                 qp->qp_num, hdr->ver, hdr->len, hdr->flags);
1427
1428         if (!(hdr->flags & DESC_DONE_FLAG)) {
1429                 dev_dbg(&qp->ndev->pdev->dev, "done flag not set\n");
1430                 qp->rx_ring_empty++;
1431                 return -EAGAIN;
1432         }
1433
1434         if (hdr->flags & LINK_DOWN_FLAG) {
1435                 dev_dbg(&qp->ndev->pdev->dev, "link down flag set\n");
1436                 ntb_qp_link_down(qp);
1437                 hdr->flags = 0;
1438                 return -EAGAIN;
1439         }
1440
1441         if (hdr->ver != (u32)qp->rx_pkts) {
1442                 dev_dbg(&qp->ndev->pdev->dev,
1443                         "version mismatch, expected %llu - got %u\n",
1444                         qp->rx_pkts, hdr->ver);
1445                 qp->rx_err_ver++;
1446                 return -EIO;
1447         }
1448
1449         entry = ntb_list_mv(&qp->ntb_rx_q_lock, &qp->rx_pend_q, &qp->rx_post_q);
1450         if (!entry) {
1451                 dev_dbg(&qp->ndev->pdev->dev, "no receive buffer\n");
1452                 qp->rx_err_no_buf++;
1453                 return -EAGAIN;
1454         }
1455
1456         entry->rx_hdr = hdr;
1457         entry->rx_index = qp->rx_index;
1458
1459         if (hdr->len > entry->len) {
1460                 dev_dbg(&qp->ndev->pdev->dev,
1461                         "receive buffer overflow! Wanted %d got %d\n",
1462                         hdr->len, entry->len);
1463                 qp->rx_err_oflow++;
1464
1465                 entry->len = -EIO;
1466                 entry->flags |= DESC_DONE_FLAG;
1467
1468                 ntb_complete_rxc(qp);
1469         } else {
1470                 dev_dbg(&qp->ndev->pdev->dev,
1471                         "RX OK index %u ver %u size %d into buf size %d\n",
1472                         qp->rx_index, hdr->ver, hdr->len, entry->len);
1473
1474                 qp->rx_bytes += hdr->len;
1475                 qp->rx_pkts++;
1476
1477                 entry->len = hdr->len;
1478
1479                 ntb_async_rx(entry, offset);
1480         }
1481
1482         qp->rx_index++;
1483         qp->rx_index %= qp->rx_max_entry;
1484
1485         return 0;
1486 }
1487
1488 static void ntb_transport_rxc_db(unsigned long data)
1489 {
1490         struct ntb_transport_qp *qp = (void *)data;
1491         int rc, i;
1492
1493         dev_dbg(&qp->ndev->pdev->dev, "%s: doorbell %d received\n",
1494                 __func__, qp->qp_num);
1495
1496         /* Limit the number of packets processed in a single interrupt to
1497          * provide fairness to others
1498          */
1499         for (i = 0; i < qp->rx_max_entry; i++) {
1500                 rc = ntb_process_rxc(qp);
1501                 if (rc)
1502                         break;
1503         }
1504
1505         if (i && qp->rx_dma_chan)
1506                 dma_async_issue_pending(qp->rx_dma_chan);
1507
1508         if (i == qp->rx_max_entry) {
1509                 /* there is more work to do */
1510                 if (qp->active)
1511                         tasklet_schedule(&qp->rxc_db_work);
1512         } else if (ntb_db_read(qp->ndev) & BIT_ULL(qp->qp_num)) {
1513                 /* the doorbell bit is set: clear it */
1514                 ntb_db_clear(qp->ndev, BIT_ULL(qp->qp_num));
1515                 /* ntb_db_read ensures ntb_db_clear write is committed */
1516                 ntb_db_read(qp->ndev);
1517
1518                 /* an interrupt may have arrived between finishing
1519                  * ntb_process_rxc and clearing the doorbell bit:
1520                  * there might be some more work to do.
1521                  */
1522                 if (qp->active)
1523                         tasklet_schedule(&qp->rxc_db_work);
1524         }
1525 }
1526
1527 static void ntb_tx_copy_callback(void *data,
1528                                  const struct dmaengine_result *res)
1529 {
1530         struct ntb_queue_entry *entry = data;
1531         struct ntb_transport_qp *qp = entry->qp;
1532         struct ntb_payload_header __iomem *hdr = entry->tx_hdr;
1533
1534         /* we need to check DMA results if we are using DMA */
1535         if (res) {
1536                 enum dmaengine_tx_result dma_err = res->result;
1537
1538                 switch (dma_err) {
1539                 case DMA_TRANS_READ_FAILED:
1540                 case DMA_TRANS_WRITE_FAILED:
1541                         entry->errors++;
1542                 case DMA_TRANS_ABORTED:
1543                 {
1544                         void __iomem *offset =
1545                                 qp->tx_mw + qp->tx_max_frame *
1546                                 entry->tx_index;
1547
1548                         /* resubmit via CPU */
1549                         ntb_memcpy_tx(entry, offset);
1550                         qp->tx_memcpy++;
1551                         return;
1552                 }
1553
1554                 case DMA_TRANS_NOERROR:
1555                 default:
1556                         break;
1557                 }
1558         }
1559
1560         iowrite32(entry->flags | DESC_DONE_FLAG, &hdr->flags);
1561
1562         ntb_peer_db_set(qp->ndev, BIT_ULL(qp->qp_num));
1563
1564         /* The entry length can only be zero if the packet is intended to be a
1565          * "link down" or similar.  Since no payload is being sent in these
1566          * cases, there is nothing to add to the completion queue.
1567          */
1568         if (entry->len > 0) {
1569                 qp->tx_bytes += entry->len;
1570
1571                 if (qp->tx_handler)
1572                         qp->tx_handler(qp, qp->cb_data, entry->cb_data,
1573                                        entry->len);
1574         }
1575
1576         ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q);
1577 }
1578
1579 static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset)
1580 {
1581 #ifdef ARCH_HAS_NOCACHE_UACCESS
1582         /*
1583          * Using non-temporal mov to improve performance on non-cached
1584          * writes, even though we aren't actually copying from user space.
1585          */
1586         __copy_from_user_inatomic_nocache(offset, entry->buf, entry->len);
1587 #else
1588         memcpy_toio(offset, entry->buf, entry->len);
1589 #endif
1590
1591         /* Ensure that the data is fully copied out before setting the flags */
1592         wmb();
1593
1594         ntb_tx_copy_callback(entry, NULL);
1595 }
1596
1597 static int ntb_async_tx_submit(struct ntb_transport_qp *qp,
1598                                struct ntb_queue_entry *entry)
1599 {
1600         struct dma_async_tx_descriptor *txd;
1601         struct dma_chan *chan = qp->tx_dma_chan;
1602         struct dma_device *device;
1603         size_t len = entry->len;
1604         void *buf = entry->buf;
1605         size_t dest_off, buff_off;
1606         struct dmaengine_unmap_data *unmap;
1607         dma_addr_t dest;
1608         dma_cookie_t cookie;
1609         int retries = 0;
1610
1611         device = chan->device;
1612         dest = qp->tx_mw_phys + qp->tx_max_frame * entry->tx_index;
1613         buff_off = (size_t)buf & ~PAGE_MASK;
1614         dest_off = (size_t)dest & ~PAGE_MASK;
1615
1616         if (!is_dma_copy_aligned(device, buff_off, dest_off, len))
1617                 goto err;
1618
1619         unmap = dmaengine_get_unmap_data(device->dev, 1, GFP_NOWAIT);
1620         if (!unmap)
1621                 goto err;
1622
1623         unmap->len = len;
1624         unmap->addr[0] = dma_map_page(device->dev, virt_to_page(buf),
1625                                       buff_off, len, DMA_TO_DEVICE);
1626         if (dma_mapping_error(device->dev, unmap->addr[0]))
1627                 goto err_get_unmap;
1628
1629         unmap->to_cnt = 1;
1630
1631         for (retries = 0; retries < DMA_RETRIES; retries++) {
1632                 txd = device->device_prep_dma_memcpy(chan, dest,
1633                                                      unmap->addr[0], len,
1634                                                      DMA_PREP_INTERRUPT);
1635                 if (txd)
1636                         break;
1637
1638                 set_current_state(TASK_INTERRUPTIBLE);
1639                 schedule_timeout(DMA_OUT_RESOURCE_TO);
1640         }
1641
1642         if (!txd) {
1643                 qp->dma_tx_prep_err++;
1644                 goto err_get_unmap;
1645         }
1646
1647         txd->callback_result = ntb_tx_copy_callback;
1648         txd->callback_param = entry;
1649         dma_set_unmap(txd, unmap);
1650
1651         cookie = dmaengine_submit(txd);
1652         if (dma_submit_error(cookie))
1653                 goto err_set_unmap;
1654
1655         dmaengine_unmap_put(unmap);
1656
1657         dma_async_issue_pending(chan);
1658
1659         return 0;
1660 err_set_unmap:
1661         dmaengine_unmap_put(unmap);
1662 err_get_unmap:
1663         dmaengine_unmap_put(unmap);
1664 err:
1665         return -ENXIO;
1666 }
1667
1668 static void ntb_async_tx(struct ntb_transport_qp *qp,
1669                          struct ntb_queue_entry *entry)
1670 {
1671         struct ntb_payload_header __iomem *hdr;
1672         struct dma_chan *chan = qp->tx_dma_chan;
1673         void __iomem *offset;
1674         int res;
1675
1676         entry->tx_index = qp->tx_index;
1677         offset = qp->tx_mw + qp->tx_max_frame * entry->tx_index;
1678         hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
1679         entry->tx_hdr = hdr;
1680
1681         iowrite32(entry->len, &hdr->len);
1682         iowrite32((u32)qp->tx_pkts, &hdr->ver);
1683
1684         if (!chan)
1685                 goto err;
1686
1687         if (entry->len < copy_bytes)
1688                 goto err;
1689
1690         res = ntb_async_tx_submit(qp, entry);
1691         if (res < 0)
1692                 goto err;
1693
1694         if (!entry->retries)
1695                 qp->tx_async++;
1696
1697         return;
1698
1699 err:
1700         ntb_memcpy_tx(entry, offset);
1701         qp->tx_memcpy++;
1702 }
1703
1704 static int ntb_process_tx(struct ntb_transport_qp *qp,
1705                           struct ntb_queue_entry *entry)
1706 {
1707         if (qp->tx_index == qp->remote_rx_info->entry) {
1708                 qp->tx_ring_full++;
1709                 return -EAGAIN;
1710         }
1711
1712         if (entry->len > qp->tx_max_frame - sizeof(struct ntb_payload_header)) {
1713                 if (qp->tx_handler)
1714                         qp->tx_handler(qp, qp->cb_data, NULL, -EIO);
1715
1716                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1717                              &qp->tx_free_q);
1718                 return 0;
1719         }
1720
1721         ntb_async_tx(qp, entry);
1722
1723         qp->tx_index++;
1724         qp->tx_index %= qp->tx_max_entry;
1725
1726         qp->tx_pkts++;
1727
1728         return 0;
1729 }
1730
1731 static void ntb_send_link_down(struct ntb_transport_qp *qp)
1732 {
1733         struct pci_dev *pdev = qp->ndev->pdev;
1734         struct ntb_queue_entry *entry;
1735         int i, rc;
1736
1737         if (!qp->link_is_up)
1738                 return;
1739
1740         dev_info(&pdev->dev, "qp %d: Send Link Down\n", qp->qp_num);
1741
1742         for (i = 0; i < NTB_LINK_DOWN_TIMEOUT; i++) {
1743                 entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1744                 if (entry)
1745                         break;
1746                 msleep(100);
1747         }
1748
1749         if (!entry)
1750                 return;
1751
1752         entry->cb_data = NULL;
1753         entry->buf = NULL;
1754         entry->len = 0;
1755         entry->flags = LINK_DOWN_FLAG;
1756
1757         rc = ntb_process_tx(qp, entry);
1758         if (rc)
1759                 dev_err(&pdev->dev, "ntb: QP%d unable to send linkdown msg\n",
1760                         qp->qp_num);
1761
1762         ntb_qp_link_down_reset(qp);
1763 }
1764
1765 static bool ntb_dma_filter_fn(struct dma_chan *chan, void *node)
1766 {
1767         return dev_to_node(&chan->dev->device) == (int)(unsigned long)node;
1768 }
1769
1770 /**
1771  * ntb_transport_create_queue - Create a new NTB transport layer queue
1772  * @rx_handler: receive callback function
1773  * @tx_handler: transmit callback function
1774  * @event_handler: event callback function
1775  *
1776  * Create a new NTB transport layer queue and provide the queue with a callback
1777  * routine for both transmit and receive.  The receive callback routine will be
1778  * used to pass up data when the transport has received it on the queue.   The
1779  * transmit callback routine will be called when the transport has completed the
1780  * transmission of the data on the queue and the data is ready to be freed.
1781  *
1782  * RETURNS: pointer to newly created ntb_queue, NULL on error.
1783  */
1784 struct ntb_transport_qp *
1785 ntb_transport_create_queue(void *data, struct device *client_dev,
1786                            const struct ntb_queue_handlers *handlers)
1787 {
1788         struct ntb_dev *ndev;
1789         struct pci_dev *pdev;
1790         struct ntb_transport_ctx *nt;
1791         struct ntb_queue_entry *entry;
1792         struct ntb_transport_qp *qp;
1793         u64 qp_bit;
1794         unsigned int free_queue;
1795         dma_cap_mask_t dma_mask;
1796         int node;
1797         int i;
1798
1799         ndev = dev_ntb(client_dev->parent);
1800         pdev = ndev->pdev;
1801         nt = ndev->ctx;
1802
1803         node = dev_to_node(&ndev->dev);
1804
1805         free_queue = ffs(nt->qp_bitmap_free);
1806         if (!free_queue)
1807                 goto err;
1808
1809         /* decrement free_queue to make it zero based */
1810         free_queue--;
1811
1812         qp = &nt->qp_vec[free_queue];
1813         qp_bit = BIT_ULL(qp->qp_num);
1814
1815         nt->qp_bitmap_free &= ~qp_bit;
1816
1817         qp->cb_data = data;
1818         qp->rx_handler = handlers->rx_handler;
1819         qp->tx_handler = handlers->tx_handler;
1820         qp->event_handler = handlers->event_handler;
1821
1822         dma_cap_zero(dma_mask);
1823         dma_cap_set(DMA_MEMCPY, dma_mask);
1824
1825         if (use_dma) {
1826                 qp->tx_dma_chan =
1827                         dma_request_channel(dma_mask, ntb_dma_filter_fn,
1828                                             (void *)(unsigned long)node);
1829                 if (!qp->tx_dma_chan)
1830                         dev_info(&pdev->dev, "Unable to allocate TX DMA channel\n");
1831
1832                 qp->rx_dma_chan =
1833                         dma_request_channel(dma_mask, ntb_dma_filter_fn,
1834                                             (void *)(unsigned long)node);
1835                 if (!qp->rx_dma_chan)
1836                         dev_info(&pdev->dev, "Unable to allocate RX DMA channel\n");
1837         } else {
1838                 qp->tx_dma_chan = NULL;
1839                 qp->rx_dma_chan = NULL;
1840         }
1841
1842         dev_dbg(&pdev->dev, "Using %s memcpy for TX\n",
1843                 qp->tx_dma_chan ? "DMA" : "CPU");
1844
1845         dev_dbg(&pdev->dev, "Using %s memcpy for RX\n",
1846                 qp->rx_dma_chan ? "DMA" : "CPU");
1847
1848         for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
1849                 entry = kzalloc_node(sizeof(*entry), GFP_ATOMIC, node);
1850                 if (!entry)
1851                         goto err1;
1852
1853                 entry->qp = qp;
1854                 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry,
1855                              &qp->rx_free_q);
1856         }
1857         qp->rx_alloc_entry = NTB_QP_DEF_NUM_ENTRIES;
1858
1859         for (i = 0; i < qp->tx_max_entry; i++) {
1860                 entry = kzalloc_node(sizeof(*entry), GFP_ATOMIC, node);
1861                 if (!entry)
1862                         goto err2;
1863
1864                 entry->qp = qp;
1865                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1866                              &qp->tx_free_q);
1867         }
1868
1869         ntb_db_clear(qp->ndev, qp_bit);
1870         ntb_db_clear_mask(qp->ndev, qp_bit);
1871
1872         dev_info(&pdev->dev, "NTB Transport QP %d created\n", qp->qp_num);
1873
1874         return qp;
1875
1876 err2:
1877         while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1878                 kfree(entry);
1879 err1:
1880         qp->rx_alloc_entry = 0;
1881         while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
1882                 kfree(entry);
1883         if (qp->tx_dma_chan)
1884                 dma_release_channel(qp->tx_dma_chan);
1885         if (qp->rx_dma_chan)
1886                 dma_release_channel(qp->rx_dma_chan);
1887         nt->qp_bitmap_free |= qp_bit;
1888 err:
1889         return NULL;
1890 }
1891 EXPORT_SYMBOL_GPL(ntb_transport_create_queue);
1892
1893 /**
1894  * ntb_transport_free_queue - Frees NTB transport queue
1895  * @qp: NTB queue to be freed
1896  *
1897  * Frees NTB transport queue
1898  */
1899 void ntb_transport_free_queue(struct ntb_transport_qp *qp)
1900 {
1901         struct pci_dev *pdev;
1902         struct ntb_queue_entry *entry;
1903         u64 qp_bit;
1904
1905         if (!qp)
1906                 return;
1907
1908         pdev = qp->ndev->pdev;
1909
1910         qp->active = false;
1911
1912         if (qp->tx_dma_chan) {
1913                 struct dma_chan *chan = qp->tx_dma_chan;
1914                 /* Putting the dma_chan to NULL will force any new traffic to be
1915                  * processed by the CPU instead of the DAM engine
1916                  */
1917                 qp->tx_dma_chan = NULL;
1918
1919                 /* Try to be nice and wait for any queued DMA engine
1920                  * transactions to process before smashing it with a rock
1921                  */
1922                 dma_sync_wait(chan, qp->last_cookie);
1923                 dmaengine_terminate_all(chan);
1924                 dma_release_channel(chan);
1925         }
1926
1927         if (qp->rx_dma_chan) {
1928                 struct dma_chan *chan = qp->rx_dma_chan;
1929                 /* Putting the dma_chan to NULL will force any new traffic to be
1930                  * processed by the CPU instead of the DAM engine
1931                  */
1932                 qp->rx_dma_chan = NULL;
1933
1934                 /* Try to be nice and wait for any queued DMA engine
1935                  * transactions to process before smashing it with a rock
1936                  */
1937                 dma_sync_wait(chan, qp->last_cookie);
1938                 dmaengine_terminate_all(chan);
1939                 dma_release_channel(chan);
1940         }
1941
1942         qp_bit = BIT_ULL(qp->qp_num);
1943
1944         ntb_db_set_mask(qp->ndev, qp_bit);
1945         tasklet_kill(&qp->rxc_db_work);
1946
1947         cancel_delayed_work_sync(&qp->link_work);
1948
1949         qp->cb_data = NULL;
1950         qp->rx_handler = NULL;
1951         qp->tx_handler = NULL;
1952         qp->event_handler = NULL;
1953
1954         while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
1955                 kfree(entry);
1956
1957         while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_pend_q))) {
1958                 dev_warn(&pdev->dev, "Freeing item from non-empty rx_pend_q\n");
1959                 kfree(entry);
1960         }
1961
1962         while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_post_q))) {
1963                 dev_warn(&pdev->dev, "Freeing item from non-empty rx_post_q\n");
1964                 kfree(entry);
1965         }
1966
1967         while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1968                 kfree(entry);
1969
1970         qp->transport->qp_bitmap_free |= qp_bit;
1971
1972         dev_info(&pdev->dev, "NTB Transport QP %d freed\n", qp->qp_num);
1973 }
1974 EXPORT_SYMBOL_GPL(ntb_transport_free_queue);
1975
1976 /**
1977  * ntb_transport_rx_remove - Dequeues enqueued rx packet
1978  * @qp: NTB queue to be freed
1979  * @len: pointer to variable to write enqueued buffers length
1980  *
1981  * Dequeues unused buffers from receive queue.  Should only be used during
1982  * shutdown of qp.
1983  *
1984  * RETURNS: NULL error value on error, or void* for success.
1985  */
1986 void *ntb_transport_rx_remove(struct ntb_transport_qp *qp, unsigned int *len)
1987 {
1988         struct ntb_queue_entry *entry;
1989         void *buf;
1990
1991         if (!qp || qp->client_ready)
1992                 return NULL;
1993
1994         entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_pend_q);
1995         if (!entry)
1996                 return NULL;
1997
1998         buf = entry->cb_data;
1999         *len = entry->len;
2000
2001         ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_free_q);
2002
2003         return buf;
2004 }
2005 EXPORT_SYMBOL_GPL(ntb_transport_rx_remove);
2006
2007 /**
2008  * ntb_transport_rx_enqueue - Enqueue a new NTB queue entry
2009  * @qp: NTB transport layer queue the entry is to be enqueued on
2010  * @cb: per buffer pointer for callback function to use
2011  * @data: pointer to data buffer that incoming packets will be copied into
2012  * @len: length of the data buffer
2013  *
2014  * Enqueue a new receive buffer onto the transport queue into which a NTB
2015  * payload can be received into.
2016  *
2017  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
2018  */
2019 int ntb_transport_rx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
2020                              unsigned int len)
2021 {
2022         struct ntb_queue_entry *entry;
2023
2024         if (!qp)
2025                 return -EINVAL;
2026
2027         entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q);
2028         if (!entry)
2029                 return -ENOMEM;
2030
2031         entry->cb_data = cb;
2032         entry->buf = data;
2033         entry->len = len;
2034         entry->flags = 0;
2035         entry->retries = 0;
2036         entry->errors = 0;
2037         entry->rx_index = 0;
2038
2039         ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_pend_q);
2040
2041         if (qp->active)
2042                 tasklet_schedule(&qp->rxc_db_work);
2043
2044         return 0;
2045 }
2046 EXPORT_SYMBOL_GPL(ntb_transport_rx_enqueue);
2047
2048 /**
2049  * ntb_transport_tx_enqueue - Enqueue a new NTB queue entry
2050  * @qp: NTB transport layer queue the entry is to be enqueued on
2051  * @cb: per buffer pointer for callback function to use
2052  * @data: pointer to data buffer that will be sent
2053  * @len: length of the data buffer
2054  *
2055  * Enqueue a new transmit buffer onto the transport queue from which a NTB
2056  * payload will be transmitted.  This assumes that a lock is being held to
2057  * serialize access to the qp.
2058  *
2059  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
2060  */
2061 int ntb_transport_tx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
2062                              unsigned int len)
2063 {
2064         struct ntb_queue_entry *entry;
2065         int rc;
2066
2067         if (!qp || !qp->link_is_up || !len)
2068                 return -EINVAL;
2069
2070         entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
2071         if (!entry) {
2072                 qp->tx_err_no_buf++;
2073                 return -EBUSY;
2074         }
2075
2076         entry->cb_data = cb;
2077         entry->buf = data;
2078         entry->len = len;
2079         entry->flags = 0;
2080         entry->errors = 0;
2081         entry->retries = 0;
2082         entry->tx_index = 0;
2083
2084         rc = ntb_process_tx(qp, entry);
2085         if (rc)
2086                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
2087                              &qp->tx_free_q);
2088
2089         return rc;
2090 }
2091 EXPORT_SYMBOL_GPL(ntb_transport_tx_enqueue);
2092
2093 /**
2094  * ntb_transport_link_up - Notify NTB transport of client readiness to use queue
2095  * @qp: NTB transport layer queue to be enabled
2096  *
2097  * Notify NTB transport layer of client readiness to use queue
2098  */
2099 void ntb_transport_link_up(struct ntb_transport_qp *qp)
2100 {
2101         if (!qp)
2102                 return;
2103
2104         qp->client_ready = true;
2105
2106         if (qp->transport->link_is_up)
2107                 schedule_delayed_work(&qp->link_work, 0);
2108 }
2109 EXPORT_SYMBOL_GPL(ntb_transport_link_up);
2110
2111 /**
2112  * ntb_transport_link_down - Notify NTB transport to no longer enqueue data
2113  * @qp: NTB transport layer queue to be disabled
2114  *
2115  * Notify NTB transport layer of client's desire to no longer receive data on
2116  * transport queue specified.  It is the client's responsibility to ensure all
2117  * entries on queue are purged or otherwise handled appropriately.
2118  */
2119 void ntb_transport_link_down(struct ntb_transport_qp *qp)
2120 {
2121         int val;
2122
2123         if (!qp)
2124                 return;
2125
2126         qp->client_ready = false;
2127
2128         val = ntb_spad_read(qp->ndev, QP_LINKS);
2129
2130         ntb_peer_spad_write(qp->ndev, QP_LINKS,
2131                             val & ~BIT(qp->qp_num));
2132
2133         if (qp->link_is_up)
2134                 ntb_send_link_down(qp);
2135         else
2136                 cancel_delayed_work_sync(&qp->link_work);
2137 }
2138 EXPORT_SYMBOL_GPL(ntb_transport_link_down);
2139
2140 /**
2141  * ntb_transport_link_query - Query transport link state
2142  * @qp: NTB transport layer queue to be queried
2143  *
2144  * Query connectivity to the remote system of the NTB transport queue
2145  *
2146  * RETURNS: true for link up or false for link down
2147  */
2148 bool ntb_transport_link_query(struct ntb_transport_qp *qp)
2149 {
2150         if (!qp)
2151                 return false;
2152
2153         return qp->link_is_up;
2154 }
2155 EXPORT_SYMBOL_GPL(ntb_transport_link_query);
2156
2157 /**
2158  * ntb_transport_qp_num - Query the qp number
2159  * @qp: NTB transport layer queue to be queried
2160  *
2161  * Query qp number of the NTB transport queue
2162  *
2163  * RETURNS: a zero based number specifying the qp number
2164  */
2165 unsigned char ntb_transport_qp_num(struct ntb_transport_qp *qp)
2166 {
2167         if (!qp)
2168                 return 0;
2169
2170         return qp->qp_num;
2171 }
2172 EXPORT_SYMBOL_GPL(ntb_transport_qp_num);
2173
2174 /**
2175  * ntb_transport_max_size - Query the max payload size of a qp
2176  * @qp: NTB transport layer queue to be queried
2177  *
2178  * Query the maximum payload size permissible on the given qp
2179  *
2180  * RETURNS: the max payload size of a qp
2181  */
2182 unsigned int ntb_transport_max_size(struct ntb_transport_qp *qp)
2183 {
2184         unsigned int max_size;
2185         unsigned int copy_align;
2186         struct dma_chan *rx_chan, *tx_chan;
2187
2188         if (!qp)
2189                 return 0;
2190
2191         rx_chan = qp->rx_dma_chan;
2192         tx_chan = qp->tx_dma_chan;
2193
2194         copy_align = max(rx_chan ? rx_chan->device->copy_align : 0,
2195                          tx_chan ? tx_chan->device->copy_align : 0);
2196
2197         /* If DMA engine usage is possible, try to find the max size for that */
2198         max_size = qp->tx_max_frame - sizeof(struct ntb_payload_header);
2199         max_size = round_down(max_size, 1 << copy_align);
2200
2201         return max_size;
2202 }
2203 EXPORT_SYMBOL_GPL(ntb_transport_max_size);
2204
2205 unsigned int ntb_transport_tx_free_entry(struct ntb_transport_qp *qp)
2206 {
2207         unsigned int head = qp->tx_index;
2208         unsigned int tail = qp->remote_rx_info->entry;
2209
2210         return tail > head ? tail - head : qp->tx_max_entry + tail - head;
2211 }
2212 EXPORT_SYMBOL_GPL(ntb_transport_tx_free_entry);
2213
2214 static void ntb_transport_doorbell_callback(void *data, int vector)
2215 {
2216         struct ntb_transport_ctx *nt = data;
2217         struct ntb_transport_qp *qp;
2218         u64 db_bits;
2219         unsigned int qp_num;
2220
2221         db_bits = (nt->qp_bitmap & ~nt->qp_bitmap_free &
2222                    ntb_db_vector_mask(nt->ndev, vector));
2223
2224         while (db_bits) {
2225                 qp_num = __ffs(db_bits);
2226                 qp = &nt->qp_vec[qp_num];
2227
2228                 if (qp->active)
2229                         tasklet_schedule(&qp->rxc_db_work);
2230
2231                 db_bits &= ~BIT_ULL(qp_num);
2232         }
2233 }
2234
2235 static const struct ntb_ctx_ops ntb_transport_ops = {
2236         .link_event = ntb_transport_event_callback,
2237         .db_event = ntb_transport_doorbell_callback,
2238 };
2239
2240 static struct ntb_client ntb_transport_client = {
2241         .ops = {
2242                 .probe = ntb_transport_probe,
2243                 .remove = ntb_transport_free,
2244         },
2245 };
2246
2247 static int __init ntb_transport_init(void)
2248 {
2249         int rc;
2250
2251         pr_info("%s, version %s\n", NTB_TRANSPORT_DESC, NTB_TRANSPORT_VER);
2252
2253         if (debugfs_initialized())
2254                 nt_debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
2255
2256         rc = bus_register(&ntb_transport_bus);
2257         if (rc)
2258                 goto err_bus;
2259
2260         rc = ntb_register_client(&ntb_transport_client);
2261         if (rc)
2262                 goto err_client;
2263
2264         return 0;
2265
2266 err_client:
2267         bus_unregister(&ntb_transport_bus);
2268 err_bus:
2269         debugfs_remove_recursive(nt_debugfs_dir);
2270         return rc;
2271 }
2272 module_init(ntb_transport_init);
2273
2274 static void __exit ntb_transport_exit(void)
2275 {
2276         ntb_unregister_client(&ntb_transport_client);
2277         bus_unregister(&ntb_transport_bus);
2278         debugfs_remove_recursive(nt_debugfs_dir);
2279 }
2280 module_exit(ntb_transport_exit);