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 bool use_msi;
  97 #ifdef CONFIG_NTB_MSI
  98 module_param(use_msi, bool, 0644);
  99 MODULE_PARM_DESC(use_msi, "Use MSI interrupts instead of doorbells");
 100 #endif
 101
 102 static struct dentry *nt_debugfs_dir;
 103
 104 /* Only two-ports NTB devices are supported */
 105 #define PIDX            NTB_DEF_PEER_IDX
 106
 107 struct ntb_queue_entry {
 108         /* ntb_queue list reference */
 109         struct list_head entry;
 110         /* pointers to data to be transferred */
 111         void *cb_data;
 112         void *buf;
 113         unsigned int len;
 114         unsigned int flags;
 115         int retries;
 116         int errors;
 117         unsigned int tx_index;
 118         unsigned int rx_index;
 119
 120         struct ntb_transport_qp *qp;
 121         union {
 122                 struct ntb_payload_header __iomem *tx_hdr;
 123                 struct ntb_payload_header *rx_hdr;
 124         };
 125 };
 126
 127 struct ntb_rx_info {
 128         unsigned int entry;
 129 };
 130
 131 struct ntb_transport_qp {
 132         struct ntb_transport_ctx *transport;
 133         struct ntb_dev *ndev;
 134         void *cb_data;
 135         struct dma_chan *tx_dma_chan;
 136         struct dma_chan *rx_dma_chan;
 137
 138         bool client_ready;
 139         bool link_is_up;
 140         bool active;
 141
 142         u8 qp_num;      /* Only 64 QP's are allowed.  0-63 */
 143         u64 qp_bit;
 144
 145         struct ntb_rx_info __iomem *rx_info;
 146         struct ntb_rx_info *remote_rx_info;
 147
 148         void (*tx_handler)(struct ntb_transport_qp *qp, void *qp_data,
 149                            void *data, int len);
 150         struct list_head tx_free_q;
 151         spinlock_t ntb_tx_free_q_lock;
 152         void __iomem *tx_mw;
 153         phys_addr_t tx_mw_phys;
 154         size_t tx_mw_size;
 155         dma_addr_t tx_mw_dma_addr;
 156         unsigned int tx_index;
 157         unsigned int tx_max_entry;
 158         unsigned int tx_max_frame;
 159
 160         void (*rx_handler)(struct ntb_transport_qp *qp, void *qp_data,
 161                            void *data, int len);
 162         struct list_head rx_post_q;
 163         struct list_head rx_pend_q;
 164         struct list_head rx_free_q;
 165         /* ntb_rx_q_lock: synchronize access to rx_XXXX_q */
 166         spinlock_t ntb_rx_q_lock;
 167         void *rx_buff;
 168         unsigned int rx_index;
 169         unsigned int rx_max_entry;
 170         unsigned int rx_max_frame;
 171         unsigned int rx_alloc_entry;
 172         dma_cookie_t last_cookie;
 173         struct tasklet_struct rxc_db_work;
 174
 175         void (*event_handler)(void *data, int status);
 176         struct delayed_work link_work;
 177         struct work_struct link_cleanup;
 178
 179         struct dentry *debugfs_dir;
 180         struct dentry *debugfs_stats;
 181
 182         /* Stats */
 183         u64 rx_bytes;
 184         u64 rx_pkts;
 185         u64 rx_ring_empty;
 186         u64 rx_err_no_buf;
 187         u64 rx_err_oflow;
 188         u64 rx_err_ver;
 189         u64 rx_memcpy;
 190         u64 rx_async;
 191         u64 tx_bytes;
 192         u64 tx_pkts;
 193         u64 tx_ring_full;
 194         u64 tx_err_no_buf;
 195         u64 tx_memcpy;
 196         u64 tx_async;
 197
 198         bool use_msi;
 199         int msi_irq;
 200         struct ntb_msi_desc msi_desc;
 201         struct ntb_msi_desc peer_msi_desc;
 202 };
 203
 204 struct ntb_transport_mw {
 205         phys_addr_t phys_addr;
 206         resource_size_t phys_size;
 207         void __iomem *vbase;
 208         size_t xlat_size;
 209         size_t buff_size;
 210         size_t alloc_size;
 211         void *alloc_addr;
 212         void *virt_addr;
 213         dma_addr_t dma_addr;
 214 };
 215
 216 struct ntb_transport_client_dev {
 217         struct list_head entry;
 218         struct ntb_transport_ctx *nt;
 219         struct device dev;
 220 };
 221
 222 struct ntb_transport_ctx {
 223         struct list_head entry;
 224         struct list_head client_devs;
 225
 226         struct ntb_dev *ndev;
 227
 228         struct ntb_transport_mw *mw_vec;
 229         struct ntb_transport_qp *qp_vec;
 230         unsigned int mw_count;
 231         unsigned int qp_count;
 232         u64 qp_bitmap;
 233         u64 qp_bitmap_free;
 234
 235         bool use_msi;
 236         unsigned int msi_spad_offset;
 237         u64 msi_db_mask;
 238
 239         bool link_is_up;
 240         struct delayed_work link_work;
 241         struct work_struct link_cleanup;
 242
 243         struct dentry *debugfs_node_dir;
 244 };
 245
 246 enum {
 247         DESC_DONE_FLAG = BIT(0),
 248         LINK_DOWN_FLAG = BIT(1),
 249 };
 250
 251 struct ntb_payload_header {
 252         unsigned int ver;
 253         unsigned int len;
 254         unsigned int flags;
 255 };
 256
 257 enum {
 258         VERSION = 0,
 259         QP_LINKS,
 260         NUM_QPS,
 261         NUM_MWS,
 262         MW0_SZ_HIGH,
 263         MW0_SZ_LOW,
 264 };
 265
 266 #define dev_client_dev(__dev) \
 267         container_of((__dev), struct ntb_transport_client_dev, dev)
 268
 269 #define drv_client(__drv) \
 270         container_of((__drv), struct ntb_transport_client, driver)
 271
 272 #define QP_TO_MW(nt, qp)        ((qp) % nt->mw_count)
 273 #define NTB_QP_DEF_NUM_ENTRIES  100
 274 #define NTB_LINK_DOWN_TIMEOUT   10
 275
 276 static void ntb_transport_rxc_db(unsigned long data);
 277 static const struct ntb_ctx_ops ntb_transport_ops;
 278 static struct ntb_client ntb_transport_client;
 279 static int ntb_async_tx_submit(struct ntb_transport_qp *qp,
 280                                struct ntb_queue_entry *entry);
 281 static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset);
 282 static int ntb_async_rx_submit(struct ntb_queue_entry *entry, void *offset);
 283 static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void *offset);
 284
 285
 286 static int ntb_transport_bus_match(struct device *dev,
 287                                    struct device_driver *drv)
 288 {
 289         return !strncmp(dev_name(dev), drv->name, strlen(drv->name));
 290 }
 291
 292 static int ntb_transport_bus_probe(struct device *dev)
 293 {
 294         const struct ntb_transport_client *client;
 295         int rc;
 296
 297         get_device(dev);
 298
 299         client = drv_client(dev->driver);
 300         rc = client->probe(dev);
 301         if (rc)
 302                 put_device(dev);
 303
 304         return rc;
 305 }
 306
 307 static void ntb_transport_bus_remove(struct device *dev)
 308 {
 309         const struct ntb_transport_client *client;
 310
 311         client = drv_client(dev->driver);
 312         client->remove(dev);
 313
 314         put_device(dev);
 315 }
 316
 317 static struct bus_type ntb_transport_bus = {
 318         .name = "ntb_transport",
 319         .match = ntb_transport_bus_match,
 320         .probe = ntb_transport_bus_probe,
 321         .remove = ntb_transport_bus_remove,
 322 };
 323
 324 static LIST_HEAD(ntb_transport_list);
 325
 326 static int ntb_bus_init(struct ntb_transport_ctx *nt)
 327 {
 328         list_add_tail(&nt->entry, &ntb_transport_list);
 329         return 0;
 330 }
 331
 332 static void ntb_bus_remove(struct ntb_transport_ctx *nt)
 333 {
 334         struct ntb_transport_client_dev *client_dev, *cd;
 335
 336         list_for_each_entry_safe(client_dev, cd, &nt->client_devs, entry) {
 337                 dev_err(client_dev->dev.parent, "%s still attached to bus, removing\n",
 338                         dev_name(&client_dev->dev));
 339                 list_del(&client_dev->entry);
 340                 device_unregister(&client_dev->dev);
 341         }
 342
 343         list_del(&nt->entry);
 344 }
 345
 346 static void ntb_transport_client_release(struct device *dev)
 347 {
 348         struct ntb_transport_client_dev *client_dev;
 349
 350         client_dev = dev_client_dev(dev);
 351         kfree(client_dev);
 352 }
 353
 354 /**
 355  * ntb_transport_unregister_client_dev - Unregister NTB client device
 356  * @device_name: Name of NTB client device
 357  *
 358  * Unregister an NTB client device with the NTB transport layer
 359  */
 360 void ntb_transport_unregister_client_dev(char *device_name)
 361 {
 362         struct ntb_transport_client_dev *client, *cd;
 363         struct ntb_transport_ctx *nt;
 364
 365         list_for_each_entry(nt, &ntb_transport_list, entry)
 366                 list_for_each_entry_safe(client, cd, &nt->client_devs, entry)
 367                         if (!strncmp(dev_name(&client->dev), device_name,
 368                                      strlen(device_name))) {
 369                                 list_del(&client->entry);
 370                                 device_unregister(&client->dev);
 371                         }
 372 }
 373 EXPORT_SYMBOL_GPL(ntb_transport_unregister_client_dev);
 374
 375 /**
 376  * ntb_transport_register_client_dev - Register NTB client device
 377  * @device_name: Name of NTB client device
 378  *
 379  * Register an NTB client device with the NTB transport layer
 380  */
 381 int ntb_transport_register_client_dev(char *device_name)
 382 {
 383         struct ntb_transport_client_dev *client_dev;
 384         struct ntb_transport_ctx *nt;
 385         int node;
 386         int rc, i = 0;
 387
 388         if (list_empty(&ntb_transport_list))
 389                 return -ENODEV;
 390
 391         list_for_each_entry(nt, &ntb_transport_list, entry) {
 392                 struct device *dev;
 393
 394                 node = dev_to_node(&nt->ndev->dev);
 395
 396                 client_dev = kzalloc_node(sizeof(*client_dev),
 397                                           GFP_KERNEL, node);
 398                 if (!client_dev) {
 399                         rc = -ENOMEM;
 400                         goto err;
 401                 }
 402
 403                 dev = &client_dev->dev;
 404
 405                 /* setup and register client devices */
 406                 dev_set_name(dev, "%s%d", device_name, i);
 407                 dev->bus = &ntb_transport_bus;
 408                 dev->release = ntb_transport_client_release;
 409                 dev->parent = &nt->ndev->dev;
 410
 411                 rc = device_register(dev);
 412                 if (rc) {
 413                         kfree(client_dev);
 414                         goto err;
 415                 }
 416
 417                 list_add_tail(&client_dev->entry, &nt->client_devs);
 418                 i++;
 419         }
 420
 421         return 0;
 422
 423 err:
 424         ntb_transport_unregister_client_dev(device_name);
 425
 426         return rc;
 427 }
 428 EXPORT_SYMBOL_GPL(ntb_transport_register_client_dev);
 429
 430 /**
 431  * ntb_transport_register_client - Register NTB client driver
 432  * @drv: NTB client driver to be registered
 433  *
 434  * Register an NTB client driver with the NTB transport layer
 435  *
 436  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 437  */
 438 int ntb_transport_register_client(struct ntb_transport_client *drv)
 439 {
 440         drv->driver.bus = &ntb_transport_bus;
 441
 442         if (list_empty(&ntb_transport_list))
 443                 return -ENODEV;
 444
 445         return driver_register(&drv->driver);
 446 }
 447 EXPORT_SYMBOL_GPL(ntb_transport_register_client);
 448
 449 /**
 450  * ntb_transport_unregister_client - Unregister NTB client driver
 451  * @drv: NTB client driver to be unregistered
 452  *
 453  * Unregister an NTB client driver with the NTB transport layer
 454  *
 455  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 456  */
 457 void ntb_transport_unregister_client(struct ntb_transport_client *drv)
 458 {
 459         driver_unregister(&drv->driver);
 460 }
 461 EXPORT_SYMBOL_GPL(ntb_transport_unregister_client);
 462
 463 static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count,
 464                             loff_t *offp)
 465 {
 466         struct ntb_transport_qp *qp;
 467         char *buf;
 468         ssize_t ret, out_offset, out_count;
 469
 470         qp = filp->private_data;
 471
 472         if (!qp || !qp->link_is_up)
 473                 return 0;
 474
 475         out_count = 1000;
 476
 477         buf = kmalloc(out_count, GFP_KERNEL);
 478         if (!buf)
 479                 return -ENOMEM;
 480
 481         out_offset = 0;
 482         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 483                                "\nNTB QP stats:\n\n");
 484         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 485                                "rx_bytes - \t%llu\n", qp->rx_bytes);
 486         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 487                                "rx_pkts - \t%llu\n", qp->rx_pkts);
 488         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 489                                "rx_memcpy - \t%llu\n", qp->rx_memcpy);
 490         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 491                                "rx_async - \t%llu\n", qp->rx_async);
 492         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 493                                "rx_ring_empty - %llu\n", qp->rx_ring_empty);
 494         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 495                                "rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
 496         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 497                                "rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
 498         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 499                                "rx_err_ver - \t%llu\n", qp->rx_err_ver);
 500         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 501                                "rx_buff - \t0x%p\n", qp->rx_buff);
 502         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 503                                "rx_index - \t%u\n", qp->rx_index);
 504         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 505                                "rx_max_entry - \t%u\n", qp->rx_max_entry);
 506         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 507                                "rx_alloc_entry - \t%u\n\n", qp->rx_alloc_entry);
 508
 509         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 510                                "tx_bytes - \t%llu\n", qp->tx_bytes);
 511         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 512                                "tx_pkts - \t%llu\n", qp->tx_pkts);
 513         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 514                                "tx_memcpy - \t%llu\n", qp->tx_memcpy);
 515         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 516                                "tx_async - \t%llu\n", qp->tx_async);
 517         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 518                                "tx_ring_full - \t%llu\n", qp->tx_ring_full);
 519         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 520                                "tx_err_no_buf - %llu\n", qp->tx_err_no_buf);
 521         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 522                                "tx_mw - \t0x%p\n", qp->tx_mw);
 523         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 524                                "tx_index (H) - \t%u\n", qp->tx_index);
 525         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 526                                "RRI (T) - \t%u\n",
 527                                qp->remote_rx_info->entry);
 528         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 529                                "tx_max_entry - \t%u\n", qp->tx_max_entry);
 530         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 531                                "free tx - \t%u\n",
 532                                ntb_transport_tx_free_entry(qp));
 533
 534         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 535                                "\n");
 536         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 537                                "Using TX DMA - \t%s\n",
 538                                qp->tx_dma_chan ? "Yes" : "No");
 539         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 540                                "Using RX DMA - \t%s\n",
 541                                qp->rx_dma_chan ? "Yes" : "No");
 542         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 543                                "QP Link - \t%s\n",
 544                                qp->link_is_up ? "Up" : "Down");
 545         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 546                                "\n");
 547
 548         if (out_offset > out_count)
 549                 out_offset = out_count;
 550
 551         ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
 552         kfree(buf);
 553         return ret;
 554 }
 555
 556 static const struct file_operations ntb_qp_debugfs_stats = {
 557         .owner = THIS_MODULE,
 558         .open = simple_open,
 559         .read = debugfs_read,
 560 };
 561
 562 static void ntb_list_add(spinlock_t *lock, struct list_head *entry,
 563                          struct list_head *list)
 564 {
 565         unsigned long flags;
 566
 567         spin_lock_irqsave(lock, flags);
 568         list_add_tail(entry, list);
 569         spin_unlock_irqrestore(lock, flags);
 570 }
 571
 572 static struct ntb_queue_entry *ntb_list_rm(spinlock_t *lock,
 573                                            struct list_head *list)
 574 {
 575         struct ntb_queue_entry *entry;
 576         unsigned long flags;
 577
 578         spin_lock_irqsave(lock, flags);
 579         if (list_empty(list)) {
 580                 entry = NULL;
 581                 goto out;
 582         }
 583         entry = list_first_entry(list, struct ntb_queue_entry, entry);
 584         list_del(&entry->entry);
 585
 586 out:
 587         spin_unlock_irqrestore(lock, flags);
 588
 589         return entry;
 590 }
 591
 592 static struct ntb_queue_entry *ntb_list_mv(spinlock_t *lock,
 593                                            struct list_head *list,
 594                                            struct list_head *to_list)
 595 {
 596         struct ntb_queue_entry *entry;
 597         unsigned long flags;
 598
 599         spin_lock_irqsave(lock, flags);
 600
 601         if (list_empty(list)) {
 602                 entry = NULL;
 603         } else {
 604                 entry = list_first_entry(list, struct ntb_queue_entry, entry);
 605                 list_move_tail(&entry->entry, to_list);
 606         }
 607
 608         spin_unlock_irqrestore(lock, flags);
 609
 610         return entry;
 611 }
 612
 613 static int ntb_transport_setup_qp_mw(struct ntb_transport_ctx *nt,
 614                                      unsigned int qp_num)
 615 {
 616         struct ntb_transport_qp *qp = &nt->qp_vec[qp_num];
 617         struct ntb_transport_mw *mw;
 618         struct ntb_dev *ndev = nt->ndev;
 619         struct ntb_queue_entry *entry;
 620         unsigned int rx_size, num_qps_mw;
 621         unsigned int mw_num, mw_count, qp_count;
 622         unsigned int i;
 623         int node;
 624
 625         mw_count = nt->mw_count;
 626         qp_count = nt->qp_count;
 627
 628         mw_num = QP_TO_MW(nt, qp_num);
 629         mw = &nt->mw_vec[mw_num];
 630
 631         if (!mw->virt_addr)
 632                 return -ENOMEM;
 633
 634         if (mw_num < qp_count % mw_count)
 635                 num_qps_mw = qp_count / mw_count + 1;
 636         else
 637                 num_qps_mw = qp_count / mw_count;
 638
 639         rx_size = (unsigned int)mw->xlat_size / num_qps_mw;
 640         qp->rx_buff = mw->virt_addr + rx_size * (qp_num / mw_count);
 641         rx_size -= sizeof(struct ntb_rx_info);
 642
 643         qp->remote_rx_info = qp->rx_buff + rx_size;
 644
 645         /* Due to housekeeping, there must be atleast 2 buffs */
 646         qp->rx_max_frame = min(transport_mtu, rx_size / 2);
 647         qp->rx_max_entry = rx_size / qp->rx_max_frame;
 648         qp->rx_index = 0;
 649
 650         /*
 651          * Checking to see if we have more entries than the default.
 652          * We should add additional entries if that is the case so we
 653          * can be in sync with the transport frames.
 654          */
 655         node = dev_to_node(&ndev->dev);
 656         for (i = qp->rx_alloc_entry; i < qp->rx_max_entry; i++) {
 657                 entry = kzalloc_node(sizeof(*entry), GFP_KERNEL, node);
 658                 if (!entry)
 659                         return -ENOMEM;
 660
 661                 entry->qp = qp;
 662                 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry,
 663                              &qp->rx_free_q);
 664                 qp->rx_alloc_entry++;
 665         }
 666
 667         qp->remote_rx_info->entry = qp->rx_max_entry - 1;
 668
 669         /* setup the hdr offsets with 0's */
 670         for (i = 0; i < qp->rx_max_entry; i++) {
 671                 void *offset = (qp->rx_buff + qp->rx_max_frame * (i + 1) -
 672                                 sizeof(struct ntb_payload_header));
 673                 memset(offset, 0, sizeof(struct ntb_payload_header));
 674         }
 675
 676         qp->rx_pkts = 0;
 677         qp->tx_pkts = 0;
 678         qp->tx_index = 0;
 679
 680         return 0;
 681 }
 682
 683 static irqreturn_t ntb_transport_isr(int irq, void *dev)
 684 {
 685         struct ntb_transport_qp *qp = dev;
 686
 687         tasklet_schedule(&qp->rxc_db_work);
 688
 689         return IRQ_HANDLED;
 690 }
 691
 692 static void ntb_transport_setup_qp_peer_msi(struct ntb_transport_ctx *nt,
 693                                             unsigned int qp_num)
 694 {
 695         struct ntb_transport_qp *qp = &nt->qp_vec[qp_num];
 696         int spad = qp_num * 2 + nt->msi_spad_offset;
 697
 698         if (!nt->use_msi)
 699                 return;
 700
 701         if (spad >= ntb_spad_count(nt->ndev))
 702                 return;
 703
 704         qp->peer_msi_desc.addr_offset =
 705                 ntb_peer_spad_read(qp->ndev, PIDX, spad);
 706         qp->peer_msi_desc.data =
 707                 ntb_peer_spad_read(qp->ndev, PIDX, spad + 1);
 708
 709         dev_dbg(&qp->ndev->pdev->dev, "QP%d Peer MSI addr=%x data=%x\n",
 710                 qp_num, qp->peer_msi_desc.addr_offset, qp->peer_msi_desc.data);
 711
 712         if (qp->peer_msi_desc.addr_offset) {
 713                 qp->use_msi = true;
 714                 dev_info(&qp->ndev->pdev->dev,
 715                          "Using MSI interrupts for QP%d\n", qp_num);
 716         }
 717 }
 718
 719 static void ntb_transport_setup_qp_msi(struct ntb_transport_ctx *nt,
 720                                        unsigned int qp_num)
 721 {
 722         struct ntb_transport_qp *qp = &nt->qp_vec[qp_num];
 723         int spad = qp_num * 2 + nt->msi_spad_offset;
 724         int rc;
 725
 726         if (!nt->use_msi)
 727                 return;
 728
 729         if (spad >= ntb_spad_count(nt->ndev)) {
 730                 dev_warn_once(&qp->ndev->pdev->dev,
 731                               "Not enough SPADS to use MSI interrupts\n");
 732                 return;
 733         }
 734
 735         ntb_spad_write(qp->ndev, spad, 0);
 736         ntb_spad_write(qp->ndev, spad + 1, 0);
 737
 738         if (!qp->msi_irq) {
 739                 qp->msi_irq = ntbm_msi_request_irq(qp->ndev, ntb_transport_isr,
 740                                                    KBUILD_MODNAME, qp,
 741                                                    &qp->msi_desc);
 742                 if (qp->msi_irq < 0) {
 743                         dev_warn(&qp->ndev->pdev->dev,
 744                                  "Unable to allocate MSI interrupt for qp%d\n",
 745                                  qp_num);
 746                         return;
 747                 }
 748         }
 749
 750         rc = ntb_spad_write(qp->ndev, spad, qp->msi_desc.addr_offset);
 751         if (rc)
 752                 goto err_free_interrupt;
 753
 754         rc = ntb_spad_write(qp->ndev, spad + 1, qp->msi_desc.data);
 755         if (rc)
 756                 goto err_free_interrupt;
 757
 758         dev_dbg(&qp->ndev->pdev->dev, "QP%d MSI %d addr=%x data=%x\n",
 759                 qp_num, qp->msi_irq, qp->msi_desc.addr_offset,
 760                 qp->msi_desc.data);
 761
 762         return;
 763
 764 err_free_interrupt:
 765         devm_free_irq(&nt->ndev->dev, qp->msi_irq, qp);
 766 }
 767
 768 static void ntb_transport_msi_peer_desc_changed(struct ntb_transport_ctx *nt)
 769 {
 770         int i;
 771
 772         dev_dbg(&nt->ndev->pdev->dev, "Peer MSI descriptors changed");
 773
 774         for (i = 0; i < nt->qp_count; i++)
 775                 ntb_transport_setup_qp_peer_msi(nt, i);
 776 }
 777
 778 static void ntb_transport_msi_desc_changed(void *data)
 779 {
 780         struct ntb_transport_ctx *nt = data;
 781         int i;
 782
 783         dev_dbg(&nt->ndev->pdev->dev, "MSI descriptors changed");
 784
 785         for (i = 0; i < nt->qp_count; i++)
 786                 ntb_transport_setup_qp_msi(nt, i);
 787
 788         ntb_peer_db_set(nt->ndev, nt->msi_db_mask);
 789 }
 790
 791 static void ntb_free_mw(struct ntb_transport_ctx *nt, int num_mw)
 792 {
 793         struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
 794         struct pci_dev *pdev = nt->ndev->pdev;
 795
 796         if (!mw->virt_addr)
 797                 return;
 798
 799         ntb_mw_clear_trans(nt->ndev, PIDX, num_mw);
 800         dma_free_coherent(&pdev->dev, mw->alloc_size,
 801                           mw->alloc_addr, mw->dma_addr);
 802         mw->xlat_size = 0;
 803         mw->buff_size = 0;
 804         mw->alloc_size = 0;
 805         mw->alloc_addr = NULL;
 806         mw->virt_addr = NULL;
 807 }
 808
 809 static int ntb_alloc_mw_buffer(struct ntb_transport_mw *mw,
 810                                struct device *dma_dev, size_t align)
 811 {
 812         dma_addr_t dma_addr;
 813         void *alloc_addr, *virt_addr;
 814         int rc;
 815
 816         alloc_addr = dma_alloc_coherent(dma_dev, mw->alloc_size,
 817                                         &dma_addr, GFP_KERNEL);
 818         if (!alloc_addr) {
 819                 dev_err(dma_dev, "Unable to alloc MW buff of size %zu\n",
 820                         mw->alloc_size);
 821                 return -ENOMEM;
 822         }
 823         virt_addr = alloc_addr;
 824
 825         /*
 826          * we must ensure that the memory address allocated is BAR size
 827          * aligned in order for the XLAT register to take the value. This
 828          * is a requirement of the hardware. It is recommended to setup CMA
 829          * for BAR sizes equal or greater than 4MB.
 830          */
 831         if (!IS_ALIGNED(dma_addr, align)) {
 832                 if (mw->alloc_size > mw->buff_size) {
 833                         virt_addr = PTR_ALIGN(alloc_addr, align);
 834                         dma_addr = ALIGN(dma_addr, align);
 835                 } else {
 836                         rc = -ENOMEM;
 837                         goto err;
 838                 }
 839         }
 840
 841         mw->alloc_addr = alloc_addr;
 842         mw->virt_addr = virt_addr;
 843         mw->dma_addr = dma_addr;
 844
 845         return 0;
 846
 847 err:
 848         dma_free_coherent(dma_dev, mw->alloc_size, alloc_addr, dma_addr);
 849
 850         return rc;
 851 }
 852
 853 static int ntb_set_mw(struct ntb_transport_ctx *nt, int num_mw,
 854                       resource_size_t size)
 855 {
 856         struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
 857         struct pci_dev *pdev = nt->ndev->pdev;
 858         size_t xlat_size, buff_size;
 859         resource_size_t xlat_align;
 860         resource_size_t xlat_align_size;
 861         int rc;
 862
 863         if (!size)
 864                 return -EINVAL;
 865
 866         rc = ntb_mw_get_align(nt->ndev, PIDX, num_mw, &xlat_align,
 867                               &xlat_align_size, NULL);
 868         if (rc)
 869                 return rc;
 870
 871         xlat_size = round_up(size, xlat_align_size);
 872         buff_size = round_up(size, xlat_align);
 873
 874         /* No need to re-setup */
 875         if (mw->xlat_size == xlat_size)
 876                 return 0;
 877
 878         if (mw->buff_size)
 879                 ntb_free_mw(nt, num_mw);
 880
 881         /* Alloc memory for receiving data.  Must be aligned */
 882         mw->xlat_size = xlat_size;
 883         mw->buff_size = buff_size;
 884         mw->alloc_size = buff_size;
 885
 886         rc = ntb_alloc_mw_buffer(mw, &pdev->dev, xlat_align);
 887         if (rc) {
 888                 mw->alloc_size *= 2;
 889                 rc = ntb_alloc_mw_buffer(mw, &pdev->dev, xlat_align);
 890                 if (rc) {
 891                         dev_err(&pdev->dev,
 892                                 "Unable to alloc aligned MW buff\n");
 893                         mw->xlat_size = 0;
 894                         mw->buff_size = 0;
 895                         mw->alloc_size = 0;
 896                         return rc;
 897                 }
 898         }
 899
 900         /* Notify HW the memory location of the receive buffer */
 901         rc = ntb_mw_set_trans(nt->ndev, PIDX, num_mw, mw->dma_addr,
 902                               mw->xlat_size);
 903         if (rc) {
 904                 dev_err(&pdev->dev, "Unable to set mw%d translation", num_mw);
 905                 ntb_free_mw(nt, num_mw);
 906                 return -EIO;
 907         }
 908
 909         return 0;
 910 }
 911
 912 static void ntb_qp_link_down_reset(struct ntb_transport_qp *qp)
 913 {
 914         qp->link_is_up = false;
 915         qp->active = false;
 916
 917         qp->tx_index = 0;
 918         qp->rx_index = 0;
 919         qp->rx_bytes = 0;
 920         qp->rx_pkts = 0;
 921         qp->rx_ring_empty = 0;
 922         qp->rx_err_no_buf = 0;
 923         qp->rx_err_oflow = 0;
 924         qp->rx_err_ver = 0;
 925         qp->rx_memcpy = 0;
 926         qp->rx_async = 0;
 927         qp->tx_bytes = 0;
 928         qp->tx_pkts = 0;
 929         qp->tx_ring_full = 0;
 930         qp->tx_err_no_buf = 0;
 931         qp->tx_memcpy = 0;
 932         qp->tx_async = 0;
 933 }
 934
 935 static void ntb_qp_link_cleanup(struct ntb_transport_qp *qp)
 936 {
 937         struct ntb_transport_ctx *nt = qp->transport;
 938         struct pci_dev *pdev = nt->ndev->pdev;
 939
 940         dev_info(&pdev->dev, "qp %d: Link Cleanup\n", qp->qp_num);
 941
 942         cancel_delayed_work_sync(&qp->link_work);
 943         ntb_qp_link_down_reset(qp);
 944
 945         if (qp->event_handler)
 946                 qp->event_handler(qp->cb_data, qp->link_is_up);
 947 }
 948
 949 static void ntb_qp_link_cleanup_work(struct work_struct *work)
 950 {
 951         struct ntb_transport_qp *qp = container_of(work,
 952                                                    struct ntb_transport_qp,
 953                                                    link_cleanup);
 954         struct ntb_transport_ctx *nt = qp->transport;
 955
 956         ntb_qp_link_cleanup(qp);
 957
 958         if (nt->link_is_up)
 959                 schedule_delayed_work(&qp->link_work,
 960                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 961 }
 962
 963 static void ntb_qp_link_down(struct ntb_transport_qp *qp)
 964 {
 965         schedule_work(&qp->link_cleanup);
 966 }
 967
 968 static void ntb_transport_link_cleanup(struct ntb_transport_ctx *nt)
 969 {
 970         struct ntb_transport_qp *qp;
 971         u64 qp_bitmap_alloc;
 972         unsigned int i, count;
 973
 974         qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
 975
 976         /* Pass along the info to any clients */
 977         for (i = 0; i < nt->qp_count; i++)
 978                 if (qp_bitmap_alloc & BIT_ULL(i)) {
 979                         qp = &nt->qp_vec[i];
 980                         ntb_qp_link_cleanup(qp);
 981                         cancel_work_sync(&qp->link_cleanup);
 982                         cancel_delayed_work_sync(&qp->link_work);
 983                 }
 984
 985         if (!nt->link_is_up)
 986                 cancel_delayed_work_sync(&nt->link_work);
 987
 988         for (i = 0; i < nt->mw_count; i++)
 989                 ntb_free_mw(nt, i);
 990
 991         /* The scratchpad registers keep the values if the remote side
 992          * goes down, blast them now to give them a sane value the next
 993          * time they are accessed
 994          */
 995         count = ntb_spad_count(nt->ndev);
 996         for (i = 0; i < count; i++)
 997                 ntb_spad_write(nt->ndev, i, 0);
 998 }
 999
1000 static void ntb_transport_link_cleanup_work(struct work_struct *work)
1001 {
1002         struct ntb_transport_ctx *nt =
1003                 container_of(work, struct ntb_transport_ctx, link_cleanup);
1004
1005         ntb_transport_link_cleanup(nt);
1006 }
1007
1008 static void ntb_transport_event_callback(void *data)
1009 {
1010         struct ntb_transport_ctx *nt = data;
1011
1012         if (ntb_link_is_up(nt->ndev, NULL, NULL) == 1)
1013                 schedule_delayed_work(&nt->link_work, 0);
1014         else
1015                 schedule_work(&nt->link_cleanup);
1016 }
1017
1018 static void ntb_transport_link_work(struct work_struct *work)
1019 {
1020         struct ntb_transport_ctx *nt =
1021                 container_of(work, struct ntb_transport_ctx, link_work.work);
1022         struct ntb_dev *ndev = nt->ndev;
1023         struct pci_dev *pdev = ndev->pdev;
1024         resource_size_t size;
1025         u32 val;
1026         int rc = 0, i, spad;
1027
1028         /* send the local info, in the opposite order of the way we read it */
1029
1030         if (nt->use_msi) {
1031                 rc = ntb_msi_setup_mws(ndev);
1032                 if (rc) {
1033                         dev_warn(&pdev->dev,
1034                                  "Failed to register MSI memory window: %d\n",
1035                                  rc);
1036                         nt->use_msi = false;
1037                 }
1038         }
1039
1040         for (i = 0; i < nt->qp_count; i++)
1041                 ntb_transport_setup_qp_msi(nt, i);
1042
1043         for (i = 0; i < nt->mw_count; i++) {
1044                 size = nt->mw_vec[i].phys_size;
1045
1046                 if (max_mw_size && size > max_mw_size)
1047                         size = max_mw_size;
1048
1049                 spad = MW0_SZ_HIGH + (i * 2);
1050                 ntb_peer_spad_write(ndev, PIDX, spad, upper_32_bits(size));
1051
1052                 spad = MW0_SZ_LOW + (i * 2);
1053                 ntb_peer_spad_write(ndev, PIDX, spad, lower_32_bits(size));
1054         }
1055
1056         ntb_peer_spad_write(ndev, PIDX, NUM_MWS, nt->mw_count);
1057
1058         ntb_peer_spad_write(ndev, PIDX, NUM_QPS, nt->qp_count);
1059
1060         ntb_peer_spad_write(ndev, PIDX, VERSION, NTB_TRANSPORT_VERSION);
1061
1062         /* Query the remote side for its info */
1063         val = ntb_spad_read(ndev, VERSION);
1064         dev_dbg(&pdev->dev, "Remote version = %d\n", val);
1065         if (val != NTB_TRANSPORT_VERSION)
1066                 goto out;
1067
1068         val = ntb_spad_read(ndev, NUM_QPS);
1069         dev_dbg(&pdev->dev, "Remote max number of qps = %d\n", val);
1070         if (val != nt->qp_count)
1071                 goto out;
1072
1073         val = ntb_spad_read(ndev, NUM_MWS);
1074         dev_dbg(&pdev->dev, "Remote number of mws = %d\n", val);
1075         if (val != nt->mw_count)
1076                 goto out;
1077
1078         for (i = 0; i < nt->mw_count; i++) {
1079                 u64 val64;
1080
1081                 val = ntb_spad_read(ndev, MW0_SZ_HIGH + (i * 2));
1082                 val64 = (u64)val << 32;
1083
1084                 val = ntb_spad_read(ndev, MW0_SZ_LOW + (i * 2));
1085                 val64 |= val;
1086
1087                 dev_dbg(&pdev->dev, "Remote MW%d size = %#llx\n", i, val64);
1088
1089                 rc = ntb_set_mw(nt, i, val64);
1090                 if (rc)
1091                         goto out1;
1092         }
1093
1094         nt->link_is_up = true;
1095
1096         for (i = 0; i < nt->qp_count; i++) {
1097                 struct ntb_transport_qp *qp = &nt->qp_vec[i];
1098
1099                 ntb_transport_setup_qp_mw(nt, i);
1100                 ntb_transport_setup_qp_peer_msi(nt, i);
1101
1102                 if (qp->client_ready)
1103                         schedule_delayed_work(&qp->link_work, 0);
1104         }
1105
1106         return;
1107
1108 out1:
1109         for (i = 0; i < nt->mw_count; i++)
1110                 ntb_free_mw(nt, i);
1111
1112         /* if there's an actual failure, we should just bail */
1113         if (rc < 0)
1114                 return;
1115
1116 out:
1117         if (ntb_link_is_up(ndev, NULL, NULL) == 1)
1118                 schedule_delayed_work(&nt->link_work,
1119                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
1120 }
1121
1122 static void ntb_qp_link_work(struct work_struct *work)
1123 {
1124         struct ntb_transport_qp *qp = container_of(work,
1125                                                    struct ntb_transport_qp,
1126                                                    link_work.work);
1127         struct pci_dev *pdev = qp->ndev->pdev;
1128         struct ntb_transport_ctx *nt = qp->transport;
1129         int val;
1130
1131         WARN_ON(!nt->link_is_up);
1132
1133         val = ntb_spad_read(nt->ndev, QP_LINKS);
1134
1135         ntb_peer_spad_write(nt->ndev, PIDX, QP_LINKS, val | BIT(qp->qp_num));
1136
1137         /* query remote spad for qp ready bits */
1138         dev_dbg_ratelimited(&pdev->dev, "Remote QP link status = %x\n", val);
1139
1140         /* See if the remote side is up */
1141         if (val & BIT(qp->qp_num)) {
1142                 dev_info(&pdev->dev, "qp %d: Link Up\n", qp->qp_num);
1143                 qp->link_is_up = true;
1144                 qp->active = true;
1145
1146                 if (qp->event_handler)
1147                         qp->event_handler(qp->cb_data, qp->link_is_up);
1148
1149                 if (qp->active)
1150                         tasklet_schedule(&qp->rxc_db_work);
1151         } else if (nt->link_is_up)
1152                 schedule_delayed_work(&qp->link_work,
1153                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
1154 }
1155
1156 static int ntb_transport_init_queue(struct ntb_transport_ctx *nt,
1157                                     unsigned int qp_num)
1158 {
1159         struct ntb_transport_qp *qp;
1160         phys_addr_t mw_base;
1161         resource_size_t mw_size;
1162         unsigned int num_qps_mw, tx_size;
1163         unsigned int mw_num, mw_count, qp_count;
1164         u64 qp_offset;
1165
1166         mw_count = nt->mw_count;
1167         qp_count = nt->qp_count;
1168
1169         mw_num = QP_TO_MW(nt, qp_num);
1170
1171         qp = &nt->qp_vec[qp_num];
1172         qp->qp_num = qp_num;
1173         qp->transport = nt;
1174         qp->ndev = nt->ndev;
1175         qp->client_ready = false;
1176         qp->event_handler = NULL;
1177         ntb_qp_link_down_reset(qp);
1178
1179         if (mw_num < qp_count % mw_count)
1180                 num_qps_mw = qp_count / mw_count + 1;
1181         else
1182                 num_qps_mw = qp_count / mw_count;
1183
1184         mw_base = nt->mw_vec[mw_num].phys_addr;
1185         mw_size = nt->mw_vec[mw_num].phys_size;
1186
1187         if (max_mw_size && mw_size > max_mw_size)
1188                 mw_size = max_mw_size;
1189
1190         tx_size = (unsigned int)mw_size / num_qps_mw;
1191         qp_offset = tx_size * (qp_num / mw_count);
1192
1193         qp->tx_mw_size = tx_size;
1194         qp->tx_mw = nt->mw_vec[mw_num].vbase + qp_offset;
1195         if (!qp->tx_mw)
1196                 return -EINVAL;
1197
1198         qp->tx_mw_phys = mw_base + qp_offset;
1199         if (!qp->tx_mw_phys)
1200                 return -EINVAL;
1201
1202         tx_size -= sizeof(struct ntb_rx_info);
1203         qp->rx_info = qp->tx_mw + tx_size;
1204
1205         /* Due to housekeeping, there must be atleast 2 buffs */
1206         qp->tx_max_frame = min(transport_mtu, tx_size / 2);
1207         qp->tx_max_entry = tx_size / qp->tx_max_frame;
1208
1209         if (nt->debugfs_node_dir) {
1210                 char debugfs_name[4];
1211
1212                 snprintf(debugfs_name, 4, "qp%d", qp_num);
1213                 qp->debugfs_dir = debugfs_create_dir(debugfs_name,
1214                                                      nt->debugfs_node_dir);
1215
1216                 qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR,
1217                                                         qp->debugfs_dir, qp,
1218                                                         &ntb_qp_debugfs_stats);
1219         } else {
1220                 qp->debugfs_dir = NULL;
1221                 qp->debugfs_stats = NULL;
1222         }
1223
1224         INIT_DELAYED_WORK(&qp->link_work, ntb_qp_link_work);
1225         INIT_WORK(&qp->link_cleanup, ntb_qp_link_cleanup_work);
1226
1227         spin_lock_init(&qp->ntb_rx_q_lock);
1228         spin_lock_init(&qp->ntb_tx_free_q_lock);
1229
1230         INIT_LIST_HEAD(&qp->rx_post_q);
1231         INIT_LIST_HEAD(&qp->rx_pend_q);
1232         INIT_LIST_HEAD(&qp->rx_free_q);
1233         INIT_LIST_HEAD(&qp->tx_free_q);
1234
1235         tasklet_init(&qp->rxc_db_work, ntb_transport_rxc_db,
1236                      (unsigned long)qp);
1237
1238         return 0;
1239 }
1240
1241 static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev)
1242 {
1243         struct ntb_transport_ctx *nt;
1244         struct ntb_transport_mw *mw;
1245         unsigned int mw_count, qp_count, spad_count, max_mw_count_for_spads;
1246         u64 qp_bitmap;
1247         int node;
1248         int rc, i;
1249
1250         mw_count = ntb_peer_mw_count(ndev);
1251
1252         if (!ndev->ops->mw_set_trans) {
1253                 dev_err(&ndev->dev, "Inbound MW based NTB API is required\n");
1254                 return -EINVAL;
1255         }
1256
1257         if (ntb_db_is_unsafe(ndev))
1258                 dev_dbg(&ndev->dev,
1259                         "doorbell is unsafe, proceed anyway...\n");
1260         if (ntb_spad_is_unsafe(ndev))
1261                 dev_dbg(&ndev->dev,
1262                         "scratchpad is unsafe, proceed anyway...\n");
1263
1264         if (ntb_peer_port_count(ndev) != NTB_DEF_PEER_CNT)
1265                 dev_warn(&ndev->dev, "Multi-port NTB devices unsupported\n");
1266
1267         node = dev_to_node(&ndev->dev);
1268
1269         nt = kzalloc_node(sizeof(*nt), GFP_KERNEL, node);
1270         if (!nt)
1271                 return -ENOMEM;
1272
1273         nt->ndev = ndev;
1274
1275         /*
1276          * If we are using MSI, and have at least one extra memory window,
1277          * we will reserve the last MW for the MSI window.
1278          */
1279         if (use_msi && mw_count > 1) {
1280                 rc = ntb_msi_init(ndev, ntb_transport_msi_desc_changed);
1281                 if (!rc) {
1282                         mw_count -= 1;
1283                         nt->use_msi = true;
1284                 }
1285         }
1286
1287         spad_count = ntb_spad_count(ndev);
1288
1289         /* Limit the MW's based on the availability of scratchpads */
1290
1291         if (spad_count < NTB_TRANSPORT_MIN_SPADS) {
1292                 nt->mw_count = 0;
1293                 rc = -EINVAL;
1294                 goto err;
1295         }
1296
1297         max_mw_count_for_spads = (spad_count - MW0_SZ_HIGH) / 2;
1298         nt->mw_count = min(mw_count, max_mw_count_for_spads);
1299
1300         nt->msi_spad_offset = nt->mw_count * 2 + MW0_SZ_HIGH;
1301
1302         nt->mw_vec = kcalloc_node(mw_count, sizeof(*nt->mw_vec),
1303                                   GFP_KERNEL, node);
1304         if (!nt->mw_vec) {
1305                 rc = -ENOMEM;
1306                 goto err;
1307         }
1308
1309         for (i = 0; i < mw_count; i++) {
1310                 mw = &nt->mw_vec[i];
1311
1312                 rc = ntb_peer_mw_get_addr(ndev, i, &mw->phys_addr,
1313                                           &mw->phys_size);
1314                 if (rc)
1315                         goto err1;
1316
1317                 mw->vbase = ioremap_wc(mw->phys_addr, mw->phys_size);
1318                 if (!mw->vbase) {
1319                         rc = -ENOMEM;
1320                         goto err1;
1321                 }
1322
1323                 mw->buff_size = 0;
1324                 mw->xlat_size = 0;
1325                 mw->virt_addr = NULL;
1326                 mw->dma_addr = 0;
1327         }
1328
1329         qp_bitmap = ntb_db_valid_mask(ndev);
1330
1331         qp_count = ilog2(qp_bitmap);
1332         if (nt->use_msi) {
1333                 qp_count -= 1;
1334                 nt->msi_db_mask = 1 << qp_count;
1335                 ntb_db_clear_mask(ndev, nt->msi_db_mask);
1336         }
1337
1338         if (max_num_clients && max_num_clients < qp_count)
1339                 qp_count = max_num_clients;
1340         else if (nt->mw_count < qp_count)
1341                 qp_count = nt->mw_count;
1342
1343         qp_bitmap &= BIT_ULL(qp_count) - 1;
1344
1345         nt->qp_count = qp_count;
1346         nt->qp_bitmap = qp_bitmap;
1347         nt->qp_bitmap_free = qp_bitmap;
1348
1349         nt->qp_vec = kcalloc_node(qp_count, sizeof(*nt->qp_vec),
1350                                   GFP_KERNEL, node);
1351         if (!nt->qp_vec) {
1352                 rc = -ENOMEM;
1353                 goto err1;
1354         }
1355
1356         if (nt_debugfs_dir) {
1357                 nt->debugfs_node_dir =
1358                         debugfs_create_dir(pci_name(ndev->pdev),
1359                                            nt_debugfs_dir);
1360         }
1361
1362         for (i = 0; i < qp_count; i++) {
1363                 rc = ntb_transport_init_queue(nt, i);
1364                 if (rc)
1365                         goto err2;
1366         }
1367
1368         INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work);
1369         INIT_WORK(&nt->link_cleanup, ntb_transport_link_cleanup_work);
1370
1371         rc = ntb_set_ctx(ndev, nt, &ntb_transport_ops);
1372         if (rc)
1373                 goto err2;
1374
1375         INIT_LIST_HEAD(&nt->client_devs);
1376         rc = ntb_bus_init(nt);
1377         if (rc)
1378                 goto err3;
1379
1380         nt->link_is_up = false;
1381         ntb_link_enable(ndev, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
1382         ntb_link_event(ndev);
1383
1384         return 0;
1385
1386 err3:
1387         ntb_clear_ctx(ndev);
1388 err2:
1389         kfree(nt->qp_vec);
1390 err1:
1391         while (i--) {
1392                 mw = &nt->mw_vec[i];
1393                 iounmap(mw->vbase);
1394         }
1395         kfree(nt->mw_vec);
1396 err:
1397         kfree(nt);
1398         return rc;
1399 }
1400
1401 static void ntb_transport_free(struct ntb_client *self, struct ntb_dev *ndev)
1402 {
1403         struct ntb_transport_ctx *nt = ndev->ctx;
1404         struct ntb_transport_qp *qp;
1405         u64 qp_bitmap_alloc;
1406         int i;
1407
1408         ntb_transport_link_cleanup(nt);
1409         cancel_work_sync(&nt->link_cleanup);
1410         cancel_delayed_work_sync(&nt->link_work);
1411
1412         qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
1413
1414         /* verify that all the qp's are freed */
1415         for (i = 0; i < nt->qp_count; i++) {
1416                 qp = &nt->qp_vec[i];
1417                 if (qp_bitmap_alloc & BIT_ULL(i))
1418                         ntb_transport_free_queue(qp);
1419                 debugfs_remove_recursive(qp->debugfs_dir);
1420         }
1421
1422         ntb_link_disable(ndev);
1423         ntb_clear_ctx(ndev);
1424
1425         ntb_bus_remove(nt);
1426
1427         for (i = nt->mw_count; i--; ) {
1428                 ntb_free_mw(nt, i);
1429                 iounmap(nt->mw_vec[i].vbase);
1430         }
1431
1432         kfree(nt->qp_vec);
1433         kfree(nt->mw_vec);
1434         kfree(nt);
1435 }
1436
1437 static void ntb_complete_rxc(struct ntb_transport_qp *qp)
1438 {
1439         struct ntb_queue_entry *entry;
1440         void *cb_data;
1441         unsigned int len;
1442         unsigned long irqflags;
1443
1444         spin_lock_irqsave(&qp->ntb_rx_q_lock, irqflags);
1445
1446         while (!list_empty(&qp->rx_post_q)) {
1447                 entry = list_first_entry(&qp->rx_post_q,
1448                                          struct ntb_queue_entry, entry);
1449                 if (!(entry->flags & DESC_DONE_FLAG))
1450                         break;
1451
1452                 entry->rx_hdr->flags = 0;
1453                 iowrite32(entry->rx_index, &qp->rx_info->entry);
1454
1455                 cb_data = entry->cb_data;
1456                 len = entry->len;
1457
1458                 list_move_tail(&entry->entry, &qp->rx_free_q);
1459
1460                 spin_unlock_irqrestore(&qp->ntb_rx_q_lock, irqflags);
1461
1462                 if (qp->rx_handler && qp->client_ready)
1463                         qp->rx_handler(qp, qp->cb_data, cb_data, len);
1464
1465                 spin_lock_irqsave(&qp->ntb_rx_q_lock, irqflags);
1466         }
1467
1468         spin_unlock_irqrestore(&qp->ntb_rx_q_lock, irqflags);
1469 }
1470
1471 static void ntb_rx_copy_callback(void *data,
1472                                  const struct dmaengine_result *res)
1473 {
1474         struct ntb_queue_entry *entry = data;
1475
1476         /* we need to check DMA results if we are using DMA */
1477         if (res) {
1478                 enum dmaengine_tx_result dma_err = res->result;
1479
1480                 switch (dma_err) {
1481                 case DMA_TRANS_READ_FAILED:
1482                 case DMA_TRANS_WRITE_FAILED:
1483                         entry->errors++;
1484                         fallthrough;
1485                 case DMA_TRANS_ABORTED:
1486                 {
1487                         struct ntb_transport_qp *qp = entry->qp;
1488                         void *offset = qp->rx_buff + qp->rx_max_frame *
1489                                         qp->rx_index;
1490
1491                         ntb_memcpy_rx(entry, offset);
1492                         qp->rx_memcpy++;
1493                         return;
1494                 }
1495
1496                 case DMA_TRANS_NOERROR:
1497                 default:
1498                         break;
1499                 }
1500         }
1501
1502         entry->flags |= DESC_DONE_FLAG;
1503
1504         ntb_complete_rxc(entry->qp);
1505 }
1506
1507 static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void *offset)
1508 {
1509         void *buf = entry->buf;
1510         size_t len = entry->len;
1511
1512         memcpy(buf, offset, len);
1513
1514         /* Ensure that the data is fully copied out before clearing the flag */
1515         wmb();
1516
1517         ntb_rx_copy_callback(entry, NULL);
1518 }
1519
1520 static int ntb_async_rx_submit(struct ntb_queue_entry *entry, void *offset)
1521 {
1522         struct dma_async_tx_descriptor *txd;
1523         struct ntb_transport_qp *qp = entry->qp;
1524         struct dma_chan *chan = qp->rx_dma_chan;
1525         struct dma_device *device;
1526         size_t pay_off, buff_off, len;
1527         struct dmaengine_unmap_data *unmap;
1528         dma_cookie_t cookie;
1529         void *buf = entry->buf;
1530
1531         len = entry->len;
1532         device = chan->device;
1533         pay_off = (size_t)offset & ~PAGE_MASK;
1534         buff_off = (size_t)buf & ~PAGE_MASK;
1535
1536         if (!is_dma_copy_aligned(device, pay_off, buff_off, len))
1537                 goto err;
1538
1539         unmap = dmaengine_get_unmap_data(device->dev, 2, GFP_NOWAIT);
1540         if (!unmap)
1541                 goto err;
1542
1543         unmap->len = len;
1544         unmap->addr[0] = dma_map_page(device->dev, virt_to_page(offset),
1545                                       pay_off, len, DMA_TO_DEVICE);
1546         if (dma_mapping_error(device->dev, unmap->addr[0]))
1547                 goto err_get_unmap;
1548
1549         unmap->to_cnt = 1;
1550
1551         unmap->addr[1] = dma_map_page(device->dev, virt_to_page(buf),
1552                                       buff_off, len, DMA_FROM_DEVICE);
1553         if (dma_mapping_error(device->dev, unmap->addr[1]))
1554                 goto err_get_unmap;
1555
1556         unmap->from_cnt = 1;
1557
1558         txd = device->device_prep_dma_memcpy(chan, unmap->addr[1],
1559                                              unmap->addr[0], len,
1560                                              DMA_PREP_INTERRUPT);
1561         if (!txd)
1562                 goto err_get_unmap;
1563
1564         txd->callback_result = ntb_rx_copy_callback;
1565         txd->callback_param = entry;
1566         dma_set_unmap(txd, unmap);
1567
1568         cookie = dmaengine_submit(txd);
1569         if (dma_submit_error(cookie))
1570                 goto err_set_unmap;
1571
1572         dmaengine_unmap_put(unmap);
1573
1574         qp->last_cookie = cookie;
1575
1576         qp->rx_async++;
1577
1578         return 0;
1579
1580 err_set_unmap:
1581         dmaengine_unmap_put(unmap);
1582 err_get_unmap:
1583         dmaengine_unmap_put(unmap);
1584 err:
1585         return -ENXIO;
1586 }
1587
1588 static void ntb_async_rx(struct ntb_queue_entry *entry, void *offset)
1589 {
1590         struct ntb_transport_qp *qp = entry->qp;
1591         struct dma_chan *chan = qp->rx_dma_chan;
1592         int res;
1593
1594         if (!chan)
1595                 goto err;
1596
1597         if (entry->len < copy_bytes)
1598                 goto err;
1599
1600         res = ntb_async_rx_submit(entry, offset);
1601         if (res < 0)
1602                 goto err;
1603
1604         if (!entry->retries)
1605                 qp->rx_async++;
1606
1607         return;
1608
1609 err:
1610         ntb_memcpy_rx(entry, offset);
1611         qp->rx_memcpy++;
1612 }
1613
1614 static int ntb_process_rxc(struct ntb_transport_qp *qp)
1615 {
1616         struct ntb_payload_header *hdr;
1617         struct ntb_queue_entry *entry;
1618         void *offset;
1619
1620         offset = qp->rx_buff + qp->rx_max_frame * qp->rx_index;
1621         hdr = offset + qp->rx_max_frame - sizeof(struct ntb_payload_header);
1622
1623         dev_dbg(&qp->ndev->pdev->dev, "qp %d: RX ver %u len %d flags %x\n",
1624                 qp->qp_num, hdr->ver, hdr->len, hdr->flags);
1625
1626         if (!(hdr->flags & DESC_DONE_FLAG)) {
1627                 dev_dbg(&qp->ndev->pdev->dev, "done flag not set\n");
1628                 qp->rx_ring_empty++;
1629                 return -EAGAIN;
1630         }
1631
1632         if (hdr->flags & LINK_DOWN_FLAG) {
1633                 dev_dbg(&qp->ndev->pdev->dev, "link down flag set\n");
1634                 ntb_qp_link_down(qp);
1635                 hdr->flags = 0;
1636                 return -EAGAIN;
1637         }
1638
1639         if (hdr->ver != (u32)qp->rx_pkts) {
1640                 dev_dbg(&qp->ndev->pdev->dev,
1641                         "version mismatch, expected %llu - got %u\n",
1642                         qp->rx_pkts, hdr->ver);
1643                 qp->rx_err_ver++;
1644                 return -EIO;
1645         }
1646
1647         entry = ntb_list_mv(&qp->ntb_rx_q_lock, &qp->rx_pend_q, &qp->rx_post_q);
1648         if (!entry) {
1649                 dev_dbg(&qp->ndev->pdev->dev, "no receive buffer\n");
1650                 qp->rx_err_no_buf++;
1651                 return -EAGAIN;
1652         }
1653
1654         entry->rx_hdr = hdr;
1655         entry->rx_index = qp->rx_index;
1656
1657         if (hdr->len > entry->len) {
1658                 dev_dbg(&qp->ndev->pdev->dev,
1659                         "receive buffer overflow! Wanted %d got %d\n",
1660                         hdr->len, entry->len);
1661                 qp->rx_err_oflow++;
1662
1663                 entry->len = -EIO;
1664                 entry->flags |= DESC_DONE_FLAG;
1665
1666                 ntb_complete_rxc(qp);
1667         } else {
1668                 dev_dbg(&qp->ndev->pdev->dev,
1669                         "RX OK index %u ver %u size %d into buf size %d\n",
1670                         qp->rx_index, hdr->ver, hdr->len, entry->len);
1671
1672                 qp->rx_bytes += hdr->len;
1673                 qp->rx_pkts++;
1674
1675                 entry->len = hdr->len;
1676
1677                 ntb_async_rx(entry, offset);
1678         }
1679
1680         qp->rx_index++;
1681         qp->rx_index %= qp->rx_max_entry;
1682
1683         return 0;
1684 }
1685
1686 static void ntb_transport_rxc_db(unsigned long data)
1687 {
1688         struct ntb_transport_qp *qp = (void *)data;
1689         int rc, i;
1690
1691         dev_dbg(&qp->ndev->pdev->dev, "%s: doorbell %d received\n",
1692                 __func__, qp->qp_num);
1693
1694         /* Limit the number of packets processed in a single interrupt to
1695          * provide fairness to others
1696          */
1697         for (i = 0; i < qp->rx_max_entry; i++) {
1698                 rc = ntb_process_rxc(qp);
1699                 if (rc)
1700                         break;
1701         }
1702
1703         if (i && qp->rx_dma_chan)
1704                 dma_async_issue_pending(qp->rx_dma_chan);
1705
1706         if (i == qp->rx_max_entry) {
1707                 /* there is more work to do */
1708                 if (qp->active)
1709                         tasklet_schedule(&qp->rxc_db_work);
1710         } else if (ntb_db_read(qp->ndev) & BIT_ULL(qp->qp_num)) {
1711                 /* the doorbell bit is set: clear it */
1712                 ntb_db_clear(qp->ndev, BIT_ULL(qp->qp_num));
1713                 /* ntb_db_read ensures ntb_db_clear write is committed */
1714                 ntb_db_read(qp->ndev);
1715
1716                 /* an interrupt may have arrived between finishing
1717                  * ntb_process_rxc and clearing the doorbell bit:
1718                  * there might be some more work to do.
1719                  */
1720                 if (qp->active)
1721                         tasklet_schedule(&qp->rxc_db_work);
1722         }
1723 }
1724
1725 static void ntb_tx_copy_callback(void *data,
1726                                  const struct dmaengine_result *res)
1727 {
1728         struct ntb_queue_entry *entry = data;
1729         struct ntb_transport_qp *qp = entry->qp;
1730         struct ntb_payload_header __iomem *hdr = entry->tx_hdr;
1731
1732         /* we need to check DMA results if we are using DMA */
1733         if (res) {
1734                 enum dmaengine_tx_result dma_err = res->result;
1735
1736                 switch (dma_err) {
1737                 case DMA_TRANS_READ_FAILED:
1738                 case DMA_TRANS_WRITE_FAILED:
1739                         entry->errors++;
1740                         fallthrough;
1741                 case DMA_TRANS_ABORTED:
1742                 {
1743                         void __iomem *offset =
1744                                 qp->tx_mw + qp->tx_max_frame *
1745                                 entry->tx_index;
1746
1747                         /* resubmit via CPU */
1748                         ntb_memcpy_tx(entry, offset);
1749                         qp->tx_memcpy++;
1750                         return;
1751                 }
1752
1753                 case DMA_TRANS_NOERROR:
1754                 default:
1755                         break;
1756                 }
1757         }
1758
1759         iowrite32(entry->flags | DESC_DONE_FLAG, &hdr->flags);
1760
1761         if (qp->use_msi)
1762                 ntb_msi_peer_trigger(qp->ndev, PIDX, &qp->peer_msi_desc);
1763         else
1764                 ntb_peer_db_set(qp->ndev, BIT_ULL(qp->qp_num));
1765
1766         /* The entry length can only be zero if the packet is intended to be a
1767          * "link down" or similar.  Since no payload is being sent in these
1768          * cases, there is nothing to add to the completion queue.
1769          */
1770         if (entry->len > 0) {
1771                 qp->tx_bytes += entry->len;
1772
1773                 if (qp->tx_handler)
1774                         qp->tx_handler(qp, qp->cb_data, entry->cb_data,
1775                                        entry->len);
1776         }
1777
1778         ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q);
1779 }
1780
1781 static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset)
1782 {
1783 #ifdef ARCH_HAS_NOCACHE_UACCESS
1784         /*
1785          * Using non-temporal mov to improve performance on non-cached
1786          * writes, even though we aren't actually copying from user space.
1787          */
1788         __copy_from_user_inatomic_nocache(offset, entry->buf, entry->len);
1789 #else
1790         memcpy_toio(offset, entry->buf, entry->len);
1791 #endif
1792
1793         /* Ensure that the data is fully copied out before setting the flags */
1794         wmb();
1795
1796         ntb_tx_copy_callback(entry, NULL);
1797 }
1798
1799 static int ntb_async_tx_submit(struct ntb_transport_qp *qp,
1800                                struct ntb_queue_entry *entry)
1801 {
1802         struct dma_async_tx_descriptor *txd;
1803         struct dma_chan *chan = qp->tx_dma_chan;
1804         struct dma_device *device;
1805         size_t len = entry->len;
1806         void *buf = entry->buf;
1807         size_t dest_off, buff_off;
1808         struct dmaengine_unmap_data *unmap;
1809         dma_addr_t dest;
1810         dma_cookie_t cookie;
1811
1812         device = chan->device;
1813         dest = qp->tx_mw_dma_addr + qp->tx_max_frame * entry->tx_index;
1814         buff_off = (size_t)buf & ~PAGE_MASK;
1815         dest_off = (size_t)dest & ~PAGE_MASK;
1816
1817         if (!is_dma_copy_aligned(device, buff_off, dest_off, len))
1818                 goto err;
1819
1820         unmap = dmaengine_get_unmap_data(device->dev, 1, GFP_NOWAIT);
1821         if (!unmap)
1822                 goto err;
1823
1824         unmap->len = len;
1825         unmap->addr[0] = dma_map_page(device->dev, virt_to_page(buf),
1826                                       buff_off, len, DMA_TO_DEVICE);
1827         if (dma_mapping_error(device->dev, unmap->addr[0]))
1828                 goto err_get_unmap;
1829
1830         unmap->to_cnt = 1;
1831
1832         txd = device->device_prep_dma_memcpy(chan, dest, unmap->addr[0], len,
1833                                              DMA_PREP_INTERRUPT);
1834         if (!txd)
1835                 goto err_get_unmap;
1836
1837         txd->callback_result = ntb_tx_copy_callback;
1838         txd->callback_param = entry;
1839         dma_set_unmap(txd, unmap);
1840
1841         cookie = dmaengine_submit(txd);
1842         if (dma_submit_error(cookie))
1843                 goto err_set_unmap;
1844
1845         dmaengine_unmap_put(unmap);
1846
1847         dma_async_issue_pending(chan);
1848
1849         return 0;
1850 err_set_unmap:
1851         dmaengine_unmap_put(unmap);
1852 err_get_unmap:
1853         dmaengine_unmap_put(unmap);
1854 err:
1855         return -ENXIO;
1856 }
1857
1858 static void ntb_async_tx(struct ntb_transport_qp *qp,
1859                          struct ntb_queue_entry *entry)
1860 {
1861         struct ntb_payload_header __iomem *hdr;
1862         struct dma_chan *chan = qp->tx_dma_chan;
1863         void __iomem *offset;
1864         int res;
1865
1866         entry->tx_index = qp->tx_index;
1867         offset = qp->tx_mw + qp->tx_max_frame * entry->tx_index;
1868         hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
1869         entry->tx_hdr = hdr;
1870
1871         iowrite32(entry->len, &hdr->len);
1872         iowrite32((u32)qp->tx_pkts, &hdr->ver);
1873
1874         if (!chan)
1875                 goto err;
1876
1877         if (entry->len < copy_bytes)
1878                 goto err;
1879
1880         res = ntb_async_tx_submit(qp, entry);
1881         if (res < 0)
1882                 goto err;
1883
1884         if (!entry->retries)
1885                 qp->tx_async++;
1886
1887         return;
1888
1889 err:
1890         ntb_memcpy_tx(entry, offset);
1891         qp->tx_memcpy++;
1892 }
1893
1894 static int ntb_process_tx(struct ntb_transport_qp *qp,
1895                           struct ntb_queue_entry *entry)
1896 {
1897         if (qp->tx_index == qp->remote_rx_info->entry) {
1898                 qp->tx_ring_full++;
1899                 return -EAGAIN;
1900         }
1901
1902         if (entry->len > qp->tx_max_frame - sizeof(struct ntb_payload_header)) {
1903                 if (qp->tx_handler)
1904                         qp->tx_handler(qp, qp->cb_data, NULL, -EIO);
1905
1906                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1907                              &qp->tx_free_q);
1908                 return 0;
1909         }
1910
1911         ntb_async_tx(qp, entry);
1912
1913         qp->tx_index++;
1914         qp->tx_index %= qp->tx_max_entry;
1915
1916         qp->tx_pkts++;
1917
1918         return 0;
1919 }
1920
1921 static void ntb_send_link_down(struct ntb_transport_qp *qp)
1922 {
1923         struct pci_dev *pdev = qp->ndev->pdev;
1924         struct ntb_queue_entry *entry;
1925         int i, rc;
1926
1927         if (!qp->link_is_up)
1928                 return;
1929
1930         dev_info(&pdev->dev, "qp %d: Send Link Down\n", qp->qp_num);
1931
1932         for (i = 0; i < NTB_LINK_DOWN_TIMEOUT; i++) {
1933                 entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1934                 if (entry)
1935                         break;
1936                 msleep(100);
1937         }
1938
1939         if (!entry)
1940                 return;
1941
1942         entry->cb_data = NULL;
1943         entry->buf = NULL;
1944         entry->len = 0;
1945         entry->flags = LINK_DOWN_FLAG;
1946
1947         rc = ntb_process_tx(qp, entry);
1948         if (rc)
1949                 dev_err(&pdev->dev, "ntb: QP%d unable to send linkdown msg\n",
1950                         qp->qp_num);
1951
1952         ntb_qp_link_down_reset(qp);
1953 }
1954
1955 static bool ntb_dma_filter_fn(struct dma_chan *chan, void *node)
1956 {
1957         return dev_to_node(&chan->dev->device) == (int)(unsigned long)node;
1958 }
1959
1960 /**
1961  * ntb_transport_create_queue - Create a new NTB transport layer queue
1962  * @rx_handler: receive callback function
1963  * @tx_handler: transmit callback function
1964  * @event_handler: event callback function
1965  *
1966  * Create a new NTB transport layer queue and provide the queue with a callback
1967  * routine for both transmit and receive.  The receive callback routine will be
1968  * used to pass up data when the transport has received it on the queue.   The
1969  * transmit callback routine will be called when the transport has completed the
1970  * transmission of the data on the queue and the data is ready to be freed.
1971  *
1972  * RETURNS: pointer to newly created ntb_queue, NULL on error.
1973  */
1974 struct ntb_transport_qp *
1975 ntb_transport_create_queue(void *data, struct device *client_dev,
1976                            const struct ntb_queue_handlers *handlers)
1977 {
1978         struct ntb_dev *ndev;
1979         struct pci_dev *pdev;
1980         struct ntb_transport_ctx *nt;
1981         struct ntb_queue_entry *entry;
1982         struct ntb_transport_qp *qp;
1983         u64 qp_bit;
1984         unsigned int free_queue;
1985         dma_cap_mask_t dma_mask;
1986         int node;
1987         int i;
1988
1989         ndev = dev_ntb(client_dev->parent);
1990         pdev = ndev->pdev;
1991         nt = ndev->ctx;
1992
1993         node = dev_to_node(&ndev->dev);
1994
1995         free_queue = ffs(nt->qp_bitmap_free);
1996         if (!free_queue)
1997                 goto err;
1998
1999         /* decrement free_queue to make it zero based */
2000         free_queue--;
2001
2002         qp = &nt->qp_vec[free_queue];
2003         qp_bit = BIT_ULL(qp->qp_num);
2004
2005         nt->qp_bitmap_free &= ~qp_bit;
2006
2007         qp->cb_data = data;
2008         qp->rx_handler = handlers->rx_handler;
2009         qp->tx_handler = handlers->tx_handler;
2010         qp->event_handler = handlers->event_handler;
2011
2012         dma_cap_zero(dma_mask);
2013         dma_cap_set(DMA_MEMCPY, dma_mask);
2014
2015         if (use_dma) {
2016                 qp->tx_dma_chan =
2017                         dma_request_channel(dma_mask, ntb_dma_filter_fn,
2018                                             (void *)(unsigned long)node);
2019                 if (!qp->tx_dma_chan)
2020                         dev_info(&pdev->dev, "Unable to allocate TX DMA channel\n");
2021
2022                 qp->rx_dma_chan =
2023                         dma_request_channel(dma_mask, ntb_dma_filter_fn,
2024                                             (void *)(unsigned long)node);
2025                 if (!qp->rx_dma_chan)
2026                         dev_info(&pdev->dev, "Unable to allocate RX DMA channel\n");
2027         } else {
2028                 qp->tx_dma_chan = NULL;
2029                 qp->rx_dma_chan = NULL;
2030         }
2031
2032         qp->tx_mw_dma_addr = 0;
2033         if (qp->tx_dma_chan) {
2034                 qp->tx_mw_dma_addr =
2035                         dma_map_resource(qp->tx_dma_chan->device->dev,
2036                                          qp->tx_mw_phys, qp->tx_mw_size,
2037                                          DMA_FROM_DEVICE, 0);
2038                 if (dma_mapping_error(qp->tx_dma_chan->device->dev,
2039                                       qp->tx_mw_dma_addr)) {
2040                         qp->tx_mw_dma_addr = 0;
2041                         goto err1;
2042                 }
2043         }
2044
2045         dev_dbg(&pdev->dev, "Using %s memcpy for TX\n",
2046                 qp->tx_dma_chan ? "DMA" : "CPU");
2047
2048         dev_dbg(&pdev->dev, "Using %s memcpy for RX\n",
2049                 qp->rx_dma_chan ? "DMA" : "CPU");
2050
2051         for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
2052                 entry = kzalloc_node(sizeof(*entry), GFP_KERNEL, node);
2053                 if (!entry)
2054                         goto err1;
2055
2056                 entry->qp = qp;
2057                 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry,
2058                              &qp->rx_free_q);
2059         }
2060         qp->rx_alloc_entry = NTB_QP_DEF_NUM_ENTRIES;
2061
2062         for (i = 0; i < qp->tx_max_entry; i++) {
2063                 entry = kzalloc_node(sizeof(*entry), GFP_KERNEL, node);
2064                 if (!entry)
2065                         goto err2;
2066
2067                 entry->qp = qp;
2068                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
2069                              &qp->tx_free_q);
2070         }
2071
2072         ntb_db_clear(qp->ndev, qp_bit);
2073         ntb_db_clear_mask(qp->ndev, qp_bit);
2074
2075         dev_info(&pdev->dev, "NTB Transport QP %d created\n", qp->qp_num);
2076
2077         return qp;
2078
2079 err2:
2080         while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
2081                 kfree(entry);
2082 err1:
2083         qp->rx_alloc_entry = 0;
2084         while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
2085                 kfree(entry);
2086         if (qp->tx_mw_dma_addr)
2087                 dma_unmap_resource(qp->tx_dma_chan->device->dev,
2088                                    qp->tx_mw_dma_addr, qp->tx_mw_size,
2089                                    DMA_FROM_DEVICE, 0);
2090         if (qp->tx_dma_chan)
2091                 dma_release_channel(qp->tx_dma_chan);
2092         if (qp->rx_dma_chan)
2093                 dma_release_channel(qp->rx_dma_chan);
2094         nt->qp_bitmap_free |= qp_bit;
2095 err:
2096         return NULL;
2097 }
2098 EXPORT_SYMBOL_GPL(ntb_transport_create_queue);
2099
2100 /**
2101  * ntb_transport_free_queue - Frees NTB transport queue
2102  * @qp: NTB queue to be freed
2103  *
2104  * Frees NTB transport queue
2105  */
2106 void ntb_transport_free_queue(struct ntb_transport_qp *qp)
2107 {
2108         struct pci_dev *pdev;
2109         struct ntb_queue_entry *entry;
2110         u64 qp_bit;
2111
2112         if (!qp)
2113                 return;
2114
2115         pdev = qp->ndev->pdev;
2116
2117         qp->active = false;
2118
2119         if (qp->tx_dma_chan) {
2120                 struct dma_chan *chan = qp->tx_dma_chan;
2121                 /* Putting the dma_chan to NULL will force any new traffic to be
2122                  * processed by the CPU instead of the DAM engine
2123                  */
2124                 qp->tx_dma_chan = NULL;
2125
2126                 /* Try to be nice and wait for any queued DMA engine
2127                  * transactions to process before smashing it with a rock
2128                  */
2129                 dma_sync_wait(chan, qp->last_cookie);
2130                 dmaengine_terminate_all(chan);
2131
2132                 dma_unmap_resource(chan->device->dev,
2133                                    qp->tx_mw_dma_addr, qp->tx_mw_size,
2134                                    DMA_FROM_DEVICE, 0);
2135
2136                 dma_release_channel(chan);
2137         }
2138
2139         if (qp->rx_dma_chan) {
2140                 struct dma_chan *chan = qp->rx_dma_chan;
2141                 /* Putting the dma_chan to NULL will force any new traffic to be
2142                  * processed by the CPU instead of the DAM engine
2143                  */
2144                 qp->rx_dma_chan = NULL;
2145
2146                 /* Try to be nice and wait for any queued DMA engine
2147                  * transactions to process before smashing it with a rock
2148                  */
2149                 dma_sync_wait(chan, qp->last_cookie);
2150                 dmaengine_terminate_all(chan);
2151                 dma_release_channel(chan);
2152         }
2153
2154         qp_bit = BIT_ULL(qp->qp_num);
2155
2156         ntb_db_set_mask(qp->ndev, qp_bit);
2157         tasklet_kill(&qp->rxc_db_work);
2158
2159         cancel_delayed_work_sync(&qp->link_work);
2160
2161         qp->cb_data = NULL;
2162         qp->rx_handler = NULL;
2163         qp->tx_handler = NULL;
2164         qp->event_handler = NULL;
2165
2166         while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
2167                 kfree(entry);
2168
2169         while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_pend_q))) {
2170                 dev_warn(&pdev->dev, "Freeing item from non-empty rx_pend_q\n");
2171                 kfree(entry);
2172         }
2173
2174         while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_post_q))) {
2175                 dev_warn(&pdev->dev, "Freeing item from non-empty rx_post_q\n");
2176                 kfree(entry);
2177         }
2178
2179         while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
2180                 kfree(entry);
2181
2182         qp->transport->qp_bitmap_free |= qp_bit;
2183
2184         dev_info(&pdev->dev, "NTB Transport QP %d freed\n", qp->qp_num);
2185 }
2186 EXPORT_SYMBOL_GPL(ntb_transport_free_queue);
2187
2188 /**
2189  * ntb_transport_rx_remove - Dequeues enqueued rx packet
2190  * @qp: NTB queue to be freed
2191  * @len: pointer to variable to write enqueued buffers length
2192  *
2193  * Dequeues unused buffers from receive queue.  Should only be used during
2194  * shutdown of qp.
2195  *
2196  * RETURNS: NULL error value on error, or void* for success.
2197  */
2198 void *ntb_transport_rx_remove(struct ntb_transport_qp *qp, unsigned int *len)
2199 {
2200         struct ntb_queue_entry *entry;
2201         void *buf;
2202
2203         if (!qp || qp->client_ready)
2204                 return NULL;
2205
2206         entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_pend_q);
2207         if (!entry)
2208                 return NULL;
2209
2210         buf = entry->cb_data;
2211         *len = entry->len;
2212
2213         ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_free_q);
2214
2215         return buf;
2216 }
2217 EXPORT_SYMBOL_GPL(ntb_transport_rx_remove);
2218
2219 /**
2220  * ntb_transport_rx_enqueue - Enqueue a new NTB queue entry
2221  * @qp: NTB transport layer queue the entry is to be enqueued on
2222  * @cb: per buffer pointer for callback function to use
2223  * @data: pointer to data buffer that incoming packets will be copied into
2224  * @len: length of the data buffer
2225  *
2226  * Enqueue a new receive buffer onto the transport queue into which a NTB
2227  * payload can be received into.
2228  *
2229  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
2230  */
2231 int ntb_transport_rx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
2232                              unsigned int len)
2233 {
2234         struct ntb_queue_entry *entry;
2235
2236         if (!qp)
2237                 return -EINVAL;
2238
2239         entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q);
2240         if (!entry)
2241                 return -ENOMEM;
2242
2243         entry->cb_data = cb;
2244         entry->buf = data;
2245         entry->len = len;
2246         entry->flags = 0;
2247         entry->retries = 0;
2248         entry->errors = 0;
2249         entry->rx_index = 0;
2250
2251         ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_pend_q);
2252
2253         if (qp->active)
2254                 tasklet_schedule(&qp->rxc_db_work);
2255
2256         return 0;
2257 }
2258 EXPORT_SYMBOL_GPL(ntb_transport_rx_enqueue);
2259
2260 /**
2261  * ntb_transport_tx_enqueue - Enqueue a new NTB queue entry
2262  * @qp: NTB transport layer queue the entry is to be enqueued on
2263  * @cb: per buffer pointer for callback function to use
2264  * @data: pointer to data buffer that will be sent
2265  * @len: length of the data buffer
2266  *
2267  * Enqueue a new transmit buffer onto the transport queue from which a NTB
2268  * payload will be transmitted.  This assumes that a lock is being held to
2269  * serialize access to the qp.
2270  *
2271  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
2272  */
2273 int ntb_transport_tx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
2274                              unsigned int len)
2275 {
2276         struct ntb_queue_entry *entry;
2277         int rc;
2278
2279         if (!qp || !qp->link_is_up || !len)
2280                 return -EINVAL;
2281
2282         entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
2283         if (!entry) {
2284                 qp->tx_err_no_buf++;
2285                 return -EBUSY;
2286         }
2287
2288         entry->cb_data = cb;
2289         entry->buf = data;
2290         entry->len = len;
2291         entry->flags = 0;
2292         entry->errors = 0;
2293         entry->retries = 0;
2294         entry->tx_index = 0;
2295
2296         rc = ntb_process_tx(qp, entry);
2297         if (rc)
2298                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
2299                              &qp->tx_free_q);
2300
2301         return rc;
2302 }
2303 EXPORT_SYMBOL_GPL(ntb_transport_tx_enqueue);
2304
2305 /**
2306  * ntb_transport_link_up - Notify NTB transport of client readiness to use queue
2307  * @qp: NTB transport layer queue to be enabled
2308  *
2309  * Notify NTB transport layer of client readiness to use queue
2310  */
2311 void ntb_transport_link_up(struct ntb_transport_qp *qp)
2312 {
2313         if (!qp)
2314                 return;
2315
2316         qp->client_ready = true;
2317
2318         if (qp->transport->link_is_up)
2319                 schedule_delayed_work(&qp->link_work, 0);
2320 }
2321 EXPORT_SYMBOL_GPL(ntb_transport_link_up);
2322
2323 /**
2324  * ntb_transport_link_down - Notify NTB transport to no longer enqueue data
2325  * @qp: NTB transport layer queue to be disabled
2326  *
2327  * Notify NTB transport layer of client's desire to no longer receive data on
2328  * transport queue specified.  It is the client's responsibility to ensure all
2329  * entries on queue are purged or otherwise handled appropriately.
2330  */
2331 void ntb_transport_link_down(struct ntb_transport_qp *qp)
2332 {
2333         int val;
2334
2335         if (!qp)
2336                 return;
2337
2338         qp->client_ready = false;
2339
2340         val = ntb_spad_read(qp->ndev, QP_LINKS);
2341
2342         ntb_peer_spad_write(qp->ndev, PIDX, QP_LINKS, val & ~BIT(qp->qp_num));
2343
2344         if (qp->link_is_up)
2345                 ntb_send_link_down(qp);
2346         else
2347                 cancel_delayed_work_sync(&qp->link_work);
2348 }
2349 EXPORT_SYMBOL_GPL(ntb_transport_link_down);
2350
2351 /**
2352  * ntb_transport_link_query - Query transport link state
2353  * @qp: NTB transport layer queue to be queried
2354  *
2355  * Query connectivity to the remote system of the NTB transport queue
2356  *
2357  * RETURNS: true for link up or false for link down
2358  */
2359 bool ntb_transport_link_query(struct ntb_transport_qp *qp)
2360 {
2361         if (!qp)
2362                 return false;
2363
2364         return qp->link_is_up;
2365 }
2366 EXPORT_SYMBOL_GPL(ntb_transport_link_query);
2367
2368 /**
2369  * ntb_transport_qp_num - Query the qp number
2370  * @qp: NTB transport layer queue to be queried
2371  *
2372  * Query qp number of the NTB transport queue
2373  *
2374  * RETURNS: a zero based number specifying the qp number
2375  */
2376 unsigned char ntb_transport_qp_num(struct ntb_transport_qp *qp)
2377 {
2378         if (!qp)
2379                 return 0;
2380
2381         return qp->qp_num;
2382 }
2383 EXPORT_SYMBOL_GPL(ntb_transport_qp_num);
2384
2385 /**
2386  * ntb_transport_max_size - Query the max payload size of a qp
2387  * @qp: NTB transport layer queue to be queried
2388  *
2389  * Query the maximum payload size permissible on the given qp
2390  *
2391  * RETURNS: the max payload size of a qp
2392  */
2393 unsigned int ntb_transport_max_size(struct ntb_transport_qp *qp)
2394 {
2395         unsigned int max_size;
2396         unsigned int copy_align;
2397         struct dma_chan *rx_chan, *tx_chan;
2398
2399         if (!qp)
2400                 return 0;
2401
2402         rx_chan = qp->rx_dma_chan;
2403         tx_chan = qp->tx_dma_chan;
2404
2405         copy_align = max(rx_chan ? rx_chan->device->copy_align : 0,
2406                          tx_chan ? tx_chan->device->copy_align : 0);
2407
2408         /* If DMA engine usage is possible, try to find the max size for that */
2409         max_size = qp->tx_max_frame - sizeof(struct ntb_payload_header);
2410         max_size = round_down(max_size, 1 << copy_align);
2411
2412         return max_size;
2413 }
2414 EXPORT_SYMBOL_GPL(ntb_transport_max_size);
2415
2416 unsigned int ntb_transport_tx_free_entry(struct ntb_transport_qp *qp)
2417 {
2418         unsigned int head = qp->tx_index;
2419         unsigned int tail = qp->remote_rx_info->entry;
2420
2421         return tail > head ? tail - head : qp->tx_max_entry + tail - head;
2422 }
2423 EXPORT_SYMBOL_GPL(ntb_transport_tx_free_entry);
2424
2425 static void ntb_transport_doorbell_callback(void *data, int vector)
2426 {
2427         struct ntb_transport_ctx *nt = data;
2428         struct ntb_transport_qp *qp;
2429         u64 db_bits;
2430         unsigned int qp_num;
2431
2432         if (ntb_db_read(nt->ndev) & nt->msi_db_mask) {
2433                 ntb_transport_msi_peer_desc_changed(nt);
2434                 ntb_db_clear(nt->ndev, nt->msi_db_mask);
2435         }
2436
2437         db_bits = (nt->qp_bitmap & ~nt->qp_bitmap_free &
2438                    ntb_db_vector_mask(nt->ndev, vector));
2439
2440         while (db_bits) {
2441                 qp_num = __ffs(db_bits);
2442                 qp = &nt->qp_vec[qp_num];
2443
2444                 if (qp->active)
2445                         tasklet_schedule(&qp->rxc_db_work);
2446
2447                 db_bits &= ~BIT_ULL(qp_num);
2448         }
2449 }
2450
2451 static const struct ntb_ctx_ops ntb_transport_ops = {
2452         .link_event = ntb_transport_event_callback,
2453         .db_event = ntb_transport_doorbell_callback,
2454 };
2455
2456 static struct ntb_client ntb_transport_client = {
2457         .ops = {
2458                 .probe = ntb_transport_probe,
2459                 .remove = ntb_transport_free,
2460         },
2461 };
2462
2463 static int __init ntb_transport_init(void)
2464 {
2465         int rc;
2466
2467         pr_info("%s, version %s\n", NTB_TRANSPORT_DESC, NTB_TRANSPORT_VER);
2468
2469         if (debugfs_initialized())
2470                 nt_debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
2471
2472         rc = bus_register(&ntb_transport_bus);
2473         if (rc)
2474                 goto err_bus;
2475
2476         rc = ntb_register_client(&ntb_transport_client);
2477         if (rc)
2478                 goto err_client;
2479
2480         return 0;
2481
2482 err_client:
2483         bus_unregister(&ntb_transport_bus);
2484 err_bus:
2485         debugfs_remove_recursive(nt_debugfs_dir);
2486         return rc;
2487 }
2488 module_init(ntb_transport_init);
2489
2490 static void __exit ntb_transport_exit(void)
2491 {
2492         ntb_unregister_client(&ntb_transport_client);
2493         bus_unregister(&ntb_transport_bus);
2494         debugfs_remove_recursive(nt_debugfs_dir);
2495 }
2496 module_exit(ntb_transport_exit);