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                         put_device(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_context_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_down_reset(struct ntb_transport_qp *qp)
 936 {
 937         ntb_qp_link_context_reset(qp);
 938         if (qp->remote_rx_info)
 939                 qp->remote_rx_info->entry = qp->rx_max_entry - 1;
 940 }
 941
 942 static void ntb_qp_link_cleanup(struct ntb_transport_qp *qp)
 943 {
 944         struct ntb_transport_ctx *nt = qp->transport;
 945         struct pci_dev *pdev = nt->ndev->pdev;
 946
 947         dev_info(&pdev->dev, "qp %d: Link Cleanup\n", qp->qp_num);
 948
 949         cancel_delayed_work_sync(&qp->link_work);
 950         ntb_qp_link_down_reset(qp);
 951
 952         if (qp->event_handler)
 953                 qp->event_handler(qp->cb_data, qp->link_is_up);
 954 }
 955
 956 static void ntb_qp_link_cleanup_work(struct work_struct *work)
 957 {
 958         struct ntb_transport_qp *qp = container_of(work,
 959                                                    struct ntb_transport_qp,
 960                                                    link_cleanup);
 961         struct ntb_transport_ctx *nt = qp->transport;
 962
 963         ntb_qp_link_cleanup(qp);
 964
 965         if (nt->link_is_up)
 966                 schedule_delayed_work(&qp->link_work,
 967                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 968 }
 969
 970 static void ntb_qp_link_down(struct ntb_transport_qp *qp)
 971 {
 972         schedule_work(&qp->link_cleanup);
 973 }
 974
 975 static void ntb_transport_link_cleanup(struct ntb_transport_ctx *nt)
 976 {
 977         struct ntb_transport_qp *qp;
 978         u64 qp_bitmap_alloc;
 979         unsigned int i, count;
 980
 981         qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
 982
 983         /* Pass along the info to any clients */
 984         for (i = 0; i < nt->qp_count; i++)
 985                 if (qp_bitmap_alloc & BIT_ULL(i)) {
 986                         qp = &nt->qp_vec[i];
 987                         ntb_qp_link_cleanup(qp);
 988                         cancel_work_sync(&qp->link_cleanup);
 989                         cancel_delayed_work_sync(&qp->link_work);
 990                 }
 991
 992         if (!nt->link_is_up)
 993                 cancel_delayed_work_sync(&nt->link_work);
 994
 995         for (i = 0; i < nt->mw_count; i++)
 996                 ntb_free_mw(nt, i);
 997
 998         /* The scratchpad registers keep the values if the remote side
 999          * goes down, blast them now to give them a sane value the next
1000          * time they are accessed
1001          */
1002         count = ntb_spad_count(nt->ndev);
1003         for (i = 0; i < count; i++)
1004                 ntb_spad_write(nt->ndev, i, 0);
1005 }
1006
1007 static void ntb_transport_link_cleanup_work(struct work_struct *work)
1008 {
1009         struct ntb_transport_ctx *nt =
1010                 container_of(work, struct ntb_transport_ctx, link_cleanup);
1011
1012         ntb_transport_link_cleanup(nt);
1013 }
1014
1015 static void ntb_transport_event_callback(void *data)
1016 {
1017         struct ntb_transport_ctx *nt = data;
1018
1019         if (ntb_link_is_up(nt->ndev, NULL, NULL) == 1)
1020                 schedule_delayed_work(&nt->link_work, 0);
1021         else
1022                 schedule_work(&nt->link_cleanup);
1023 }
1024
1025 static void ntb_transport_link_work(struct work_struct *work)
1026 {
1027         struct ntb_transport_ctx *nt =
1028                 container_of(work, struct ntb_transport_ctx, link_work.work);
1029         struct ntb_dev *ndev = nt->ndev;
1030         struct pci_dev *pdev = ndev->pdev;
1031         resource_size_t size;
1032         u32 val;
1033         int rc = 0, i, spad;
1034
1035         /* send the local info, in the opposite order of the way we read it */
1036
1037         if (nt->use_msi) {
1038                 rc = ntb_msi_setup_mws(ndev);
1039                 if (rc) {
1040                         dev_warn(&pdev->dev,
1041                                  "Failed to register MSI memory window: %d\n",
1042                                  rc);
1043                         nt->use_msi = false;
1044                 }
1045         }
1046
1047         for (i = 0; i < nt->qp_count; i++)
1048                 ntb_transport_setup_qp_msi(nt, i);
1049
1050         for (i = 0; i < nt->mw_count; i++) {
1051                 size = nt->mw_vec[i].phys_size;
1052
1053                 if (max_mw_size && size > max_mw_size)
1054                         size = max_mw_size;
1055
1056                 spad = MW0_SZ_HIGH + (i * 2);
1057                 ntb_peer_spad_write(ndev, PIDX, spad, upper_32_bits(size));
1058
1059                 spad = MW0_SZ_LOW + (i * 2);
1060                 ntb_peer_spad_write(ndev, PIDX, spad, lower_32_bits(size));
1061         }
1062
1063         ntb_peer_spad_write(ndev, PIDX, NUM_MWS, nt->mw_count);
1064
1065         ntb_peer_spad_write(ndev, PIDX, NUM_QPS, nt->qp_count);
1066
1067         ntb_peer_spad_write(ndev, PIDX, VERSION, NTB_TRANSPORT_VERSION);
1068
1069         /* Query the remote side for its info */
1070         val = ntb_spad_read(ndev, VERSION);
1071         dev_dbg(&pdev->dev, "Remote version = %d\n", val);
1072         if (val != NTB_TRANSPORT_VERSION)
1073                 goto out;
1074
1075         val = ntb_spad_read(ndev, NUM_QPS);
1076         dev_dbg(&pdev->dev, "Remote max number of qps = %d\n", val);
1077         if (val != nt->qp_count)
1078                 goto out;
1079
1080         val = ntb_spad_read(ndev, NUM_MWS);
1081         dev_dbg(&pdev->dev, "Remote number of mws = %d\n", val);
1082         if (val != nt->mw_count)
1083                 goto out;
1084
1085         for (i = 0; i < nt->mw_count; i++) {
1086                 u64 val64;
1087
1088                 val = ntb_spad_read(ndev, MW0_SZ_HIGH + (i * 2));
1089                 val64 = (u64)val << 32;
1090
1091                 val = ntb_spad_read(ndev, MW0_SZ_LOW + (i * 2));
1092                 val64 |= val;
1093
1094                 dev_dbg(&pdev->dev, "Remote MW%d size = %#llx\n", i, val64);
1095
1096                 rc = ntb_set_mw(nt, i, val64);
1097                 if (rc)
1098                         goto out1;
1099         }
1100
1101         nt->link_is_up = true;
1102
1103         for (i = 0; i < nt->qp_count; i++) {
1104                 struct ntb_transport_qp *qp = &nt->qp_vec[i];
1105
1106                 ntb_transport_setup_qp_mw(nt, i);
1107                 ntb_transport_setup_qp_peer_msi(nt, i);
1108
1109                 if (qp->client_ready)
1110                         schedule_delayed_work(&qp->link_work, 0);
1111         }
1112
1113         return;
1114
1115 out1:
1116         for (i = 0; i < nt->mw_count; i++)
1117                 ntb_free_mw(nt, i);
1118
1119         /* if there's an actual failure, we should just bail */
1120         if (rc < 0)
1121                 return;
1122
1123 out:
1124         if (ntb_link_is_up(ndev, NULL, NULL) == 1)
1125                 schedule_delayed_work(&nt->link_work,
1126                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
1127 }
1128
1129 static void ntb_qp_link_work(struct work_struct *work)
1130 {
1131         struct ntb_transport_qp *qp = container_of(work,
1132                                                    struct ntb_transport_qp,
1133                                                    link_work.work);
1134         struct pci_dev *pdev = qp->ndev->pdev;
1135         struct ntb_transport_ctx *nt = qp->transport;
1136         int val;
1137
1138         WARN_ON(!nt->link_is_up);
1139
1140         val = ntb_spad_read(nt->ndev, QP_LINKS);
1141
1142         ntb_peer_spad_write(nt->ndev, PIDX, QP_LINKS, val | BIT(qp->qp_num));
1143
1144         /* query remote spad for qp ready bits */
1145         dev_dbg_ratelimited(&pdev->dev, "Remote QP link status = %x\n", val);
1146
1147         /* See if the remote side is up */
1148         if (val & BIT(qp->qp_num)) {
1149                 dev_info(&pdev->dev, "qp %d: Link Up\n", qp->qp_num);
1150                 qp->link_is_up = true;
1151                 qp->active = true;
1152
1153                 if (qp->event_handler)
1154                         qp->event_handler(qp->cb_data, qp->link_is_up);
1155
1156                 if (qp->active)
1157                         tasklet_schedule(&qp->rxc_db_work);
1158         } else if (nt->link_is_up)
1159                 schedule_delayed_work(&qp->link_work,
1160                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
1161 }
1162
1163 static int ntb_transport_init_queue(struct ntb_transport_ctx *nt,
1164                                     unsigned int qp_num)
1165 {
1166         struct ntb_transport_qp *qp;
1167         phys_addr_t mw_base;
1168         resource_size_t mw_size;
1169         unsigned int num_qps_mw, tx_size;
1170         unsigned int mw_num, mw_count, qp_count;
1171         u64 qp_offset;
1172
1173         mw_count = nt->mw_count;
1174         qp_count = nt->qp_count;
1175
1176         mw_num = QP_TO_MW(nt, qp_num);
1177
1178         qp = &nt->qp_vec[qp_num];
1179         qp->qp_num = qp_num;
1180         qp->transport = nt;
1181         qp->ndev = nt->ndev;
1182         qp->client_ready = false;
1183         qp->event_handler = NULL;
1184         ntb_qp_link_context_reset(qp);
1185
1186         if (mw_num < qp_count % mw_count)
1187                 num_qps_mw = qp_count / mw_count + 1;
1188         else
1189                 num_qps_mw = qp_count / mw_count;
1190
1191         mw_base = nt->mw_vec[mw_num].phys_addr;
1192         mw_size = nt->mw_vec[mw_num].phys_size;
1193
1194         if (max_mw_size && mw_size > max_mw_size)
1195                 mw_size = max_mw_size;
1196
1197         tx_size = (unsigned int)mw_size / num_qps_mw;
1198         qp_offset = tx_size * (qp_num / mw_count);
1199
1200         qp->tx_mw_size = tx_size;
1201         qp->tx_mw = nt->mw_vec[mw_num].vbase + qp_offset;
1202         if (!qp->tx_mw)
1203                 return -EINVAL;
1204
1205         qp->tx_mw_phys = mw_base + qp_offset;
1206         if (!qp->tx_mw_phys)
1207                 return -EINVAL;
1208
1209         tx_size -= sizeof(struct ntb_rx_info);
1210         qp->rx_info = qp->tx_mw + tx_size;
1211
1212         /* Due to housekeeping, there must be atleast 2 buffs */
1213         qp->tx_max_frame = min(transport_mtu, tx_size / 2);
1214         qp->tx_max_entry = tx_size / qp->tx_max_frame;
1215
1216         if (nt->debugfs_node_dir) {
1217                 char debugfs_name[4];
1218
1219                 snprintf(debugfs_name, 4, "qp%d", qp_num);
1220                 qp->debugfs_dir = debugfs_create_dir(debugfs_name,
1221                                                      nt->debugfs_node_dir);
1222
1223                 qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR,
1224                                                         qp->debugfs_dir, qp,
1225                                                         &ntb_qp_debugfs_stats);
1226         } else {
1227                 qp->debugfs_dir = NULL;
1228                 qp->debugfs_stats = NULL;
1229         }
1230
1231         INIT_DELAYED_WORK(&qp->link_work, ntb_qp_link_work);
1232         INIT_WORK(&qp->link_cleanup, ntb_qp_link_cleanup_work);
1233
1234         spin_lock_init(&qp->ntb_rx_q_lock);
1235         spin_lock_init(&qp->ntb_tx_free_q_lock);
1236
1237         INIT_LIST_HEAD(&qp->rx_post_q);
1238         INIT_LIST_HEAD(&qp->rx_pend_q);
1239         INIT_LIST_HEAD(&qp->rx_free_q);
1240         INIT_LIST_HEAD(&qp->tx_free_q);
1241
1242         tasklet_init(&qp->rxc_db_work, ntb_transport_rxc_db,
1243                      (unsigned long)qp);
1244
1245         return 0;
1246 }
1247
1248 static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev)
1249 {
1250         struct ntb_transport_ctx *nt;
1251         struct ntb_transport_mw *mw;
1252         unsigned int mw_count, qp_count, spad_count, max_mw_count_for_spads;
1253         u64 qp_bitmap;
1254         int node;
1255         int rc, i;
1256
1257         mw_count = ntb_peer_mw_count(ndev);
1258
1259         if (!ndev->ops->mw_set_trans) {
1260                 dev_err(&ndev->dev, "Inbound MW based NTB API is required\n");
1261                 return -EINVAL;
1262         }
1263
1264         if (ntb_db_is_unsafe(ndev))
1265                 dev_dbg(&ndev->dev,
1266                         "doorbell is unsafe, proceed anyway...\n");
1267         if (ntb_spad_is_unsafe(ndev))
1268                 dev_dbg(&ndev->dev,
1269                         "scratchpad is unsafe, proceed anyway...\n");
1270
1271         if (ntb_peer_port_count(ndev) != NTB_DEF_PEER_CNT)
1272                 dev_warn(&ndev->dev, "Multi-port NTB devices unsupported\n");
1273
1274         node = dev_to_node(&ndev->dev);
1275
1276         nt = kzalloc_node(sizeof(*nt), GFP_KERNEL, node);
1277         if (!nt)
1278                 return -ENOMEM;
1279
1280         nt->ndev = ndev;
1281
1282         /*
1283          * If we are using MSI, and have at least one extra memory window,
1284          * we will reserve the last MW for the MSI window.
1285          */
1286         if (use_msi && mw_count > 1) {
1287                 rc = ntb_msi_init(ndev, ntb_transport_msi_desc_changed);
1288                 if (!rc) {
1289                         mw_count -= 1;
1290                         nt->use_msi = true;
1291                 }
1292         }
1293
1294         spad_count = ntb_spad_count(ndev);
1295
1296         /* Limit the MW's based on the availability of scratchpads */
1297
1298         if (spad_count < NTB_TRANSPORT_MIN_SPADS) {
1299                 nt->mw_count = 0;
1300                 rc = -EINVAL;
1301                 goto err;
1302         }
1303
1304         max_mw_count_for_spads = (spad_count - MW0_SZ_HIGH) / 2;
1305         nt->mw_count = min(mw_count, max_mw_count_for_spads);
1306
1307         nt->msi_spad_offset = nt->mw_count * 2 + MW0_SZ_HIGH;
1308
1309         nt->mw_vec = kcalloc_node(mw_count, sizeof(*nt->mw_vec),
1310                                   GFP_KERNEL, node);
1311         if (!nt->mw_vec) {
1312                 rc = -ENOMEM;
1313                 goto err;
1314         }
1315
1316         for (i = 0; i < mw_count; i++) {
1317                 mw = &nt->mw_vec[i];
1318
1319                 rc = ntb_peer_mw_get_addr(ndev, i, &mw->phys_addr,
1320                                           &mw->phys_size);
1321                 if (rc)
1322                         goto err1;
1323
1324                 mw->vbase = ioremap_wc(mw->phys_addr, mw->phys_size);
1325                 if (!mw->vbase) {
1326                         rc = -ENOMEM;
1327                         goto err1;
1328                 }
1329
1330                 mw->buff_size = 0;
1331                 mw->xlat_size = 0;
1332                 mw->virt_addr = NULL;
1333                 mw->dma_addr = 0;
1334         }
1335
1336         qp_bitmap = ntb_db_valid_mask(ndev);
1337
1338         qp_count = ilog2(qp_bitmap);
1339         if (nt->use_msi) {
1340                 qp_count -= 1;
1341                 nt->msi_db_mask = 1 << qp_count;
1342                 ntb_db_clear_mask(ndev, nt->msi_db_mask);
1343         }
1344
1345         if (max_num_clients && max_num_clients < qp_count)
1346                 qp_count = max_num_clients;
1347         else if (nt->mw_count < qp_count)
1348                 qp_count = nt->mw_count;
1349
1350         qp_bitmap &= BIT_ULL(qp_count) - 1;
1351
1352         nt->qp_count = qp_count;
1353         nt->qp_bitmap = qp_bitmap;
1354         nt->qp_bitmap_free = qp_bitmap;
1355
1356         nt->qp_vec = kcalloc_node(qp_count, sizeof(*nt->qp_vec),
1357                                   GFP_KERNEL, node);
1358         if (!nt->qp_vec) {
1359                 rc = -ENOMEM;
1360                 goto err1;
1361         }
1362
1363         if (nt_debugfs_dir) {
1364                 nt->debugfs_node_dir =
1365                         debugfs_create_dir(pci_name(ndev->pdev),
1366                                            nt_debugfs_dir);
1367         }
1368
1369         for (i = 0; i < qp_count; i++) {
1370                 rc = ntb_transport_init_queue(nt, i);
1371                 if (rc)
1372                         goto err2;
1373         }
1374
1375         INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work);
1376         INIT_WORK(&nt->link_cleanup, ntb_transport_link_cleanup_work);
1377
1378         rc = ntb_set_ctx(ndev, nt, &ntb_transport_ops);
1379         if (rc)
1380                 goto err2;
1381
1382         INIT_LIST_HEAD(&nt->client_devs);
1383         rc = ntb_bus_init(nt);
1384         if (rc)
1385                 goto err3;
1386
1387         nt->link_is_up = false;
1388         ntb_link_enable(ndev, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
1389         ntb_link_event(ndev);
1390
1391         return 0;
1392
1393 err3:
1394         ntb_clear_ctx(ndev);
1395 err2:
1396         kfree(nt->qp_vec);
1397 err1:
1398         while (i--) {
1399                 mw = &nt->mw_vec[i];
1400                 iounmap(mw->vbase);
1401         }
1402         kfree(nt->mw_vec);
1403 err:
1404         kfree(nt);
1405         return rc;
1406 }
1407
1408 static void ntb_transport_free(struct ntb_client *self, struct ntb_dev *ndev)
1409 {
1410         struct ntb_transport_ctx *nt = ndev->ctx;
1411         struct ntb_transport_qp *qp;
1412         u64 qp_bitmap_alloc;
1413         int i;
1414
1415         ntb_transport_link_cleanup(nt);
1416         cancel_work_sync(&nt->link_cleanup);
1417         cancel_delayed_work_sync(&nt->link_work);
1418
1419         qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
1420
1421         /* verify that all the qp's are freed */
1422         for (i = 0; i < nt->qp_count; i++) {
1423                 qp = &nt->qp_vec[i];
1424                 if (qp_bitmap_alloc & BIT_ULL(i))
1425                         ntb_transport_free_queue(qp);
1426                 debugfs_remove_recursive(qp->debugfs_dir);
1427         }
1428
1429         ntb_link_disable(ndev);
1430         ntb_clear_ctx(ndev);
1431
1432         ntb_bus_remove(nt);
1433
1434         for (i = nt->mw_count; i--; ) {
1435                 ntb_free_mw(nt, i);
1436                 iounmap(nt->mw_vec[i].vbase);
1437         }
1438
1439         kfree(nt->qp_vec);
1440         kfree(nt->mw_vec);
1441         kfree(nt);
1442 }
1443
1444 static void ntb_complete_rxc(struct ntb_transport_qp *qp)
1445 {
1446         struct ntb_queue_entry *entry;
1447         void *cb_data;
1448         unsigned int len;
1449         unsigned long irqflags;
1450
1451         spin_lock_irqsave(&qp->ntb_rx_q_lock, irqflags);
1452
1453         while (!list_empty(&qp->rx_post_q)) {
1454                 entry = list_first_entry(&qp->rx_post_q,
1455                                          struct ntb_queue_entry, entry);
1456                 if (!(entry->flags & DESC_DONE_FLAG))
1457                         break;
1458
1459                 entry->rx_hdr->flags = 0;
1460                 iowrite32(entry->rx_index, &qp->rx_info->entry);
1461
1462                 cb_data = entry->cb_data;
1463                 len = entry->len;
1464
1465                 list_move_tail(&entry->entry, &qp->rx_free_q);
1466
1467                 spin_unlock_irqrestore(&qp->ntb_rx_q_lock, irqflags);
1468
1469                 if (qp->rx_handler && qp->client_ready)
1470                         qp->rx_handler(qp, qp->cb_data, cb_data, len);
1471
1472                 spin_lock_irqsave(&qp->ntb_rx_q_lock, irqflags);
1473         }
1474
1475         spin_unlock_irqrestore(&qp->ntb_rx_q_lock, irqflags);
1476 }
1477
1478 static void ntb_rx_copy_callback(void *data,
1479                                  const struct dmaengine_result *res)
1480 {
1481         struct ntb_queue_entry *entry = data;
1482
1483         /* we need to check DMA results if we are using DMA */
1484         if (res) {
1485                 enum dmaengine_tx_result dma_err = res->result;
1486
1487                 switch (dma_err) {
1488                 case DMA_TRANS_READ_FAILED:
1489                 case DMA_TRANS_WRITE_FAILED:
1490                         entry->errors++;
1491                         fallthrough;
1492                 case DMA_TRANS_ABORTED:
1493                 {
1494                         struct ntb_transport_qp *qp = entry->qp;
1495                         void *offset = qp->rx_buff + qp->rx_max_frame *
1496                                         qp->rx_index;
1497
1498                         ntb_memcpy_rx(entry, offset);
1499                         qp->rx_memcpy++;
1500                         return;
1501                 }
1502
1503                 case DMA_TRANS_NOERROR:
1504                 default:
1505                         break;
1506                 }
1507         }
1508
1509         entry->flags |= DESC_DONE_FLAG;
1510
1511         ntb_complete_rxc(entry->qp);
1512 }
1513
1514 static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void *offset)
1515 {
1516         void *buf = entry->buf;
1517         size_t len = entry->len;
1518
1519         memcpy(buf, offset, len);
1520
1521         /* Ensure that the data is fully copied out before clearing the flag */
1522         wmb();
1523
1524         ntb_rx_copy_callback(entry, NULL);
1525 }
1526
1527 static int ntb_async_rx_submit(struct ntb_queue_entry *entry, void *offset)
1528 {
1529         struct dma_async_tx_descriptor *txd;
1530         struct ntb_transport_qp *qp = entry->qp;
1531         struct dma_chan *chan = qp->rx_dma_chan;
1532         struct dma_device *device;
1533         size_t pay_off, buff_off, len;
1534         struct dmaengine_unmap_data *unmap;
1535         dma_cookie_t cookie;
1536         void *buf = entry->buf;
1537
1538         len = entry->len;
1539         device = chan->device;
1540         pay_off = (size_t)offset & ~PAGE_MASK;
1541         buff_off = (size_t)buf & ~PAGE_MASK;
1542
1543         if (!is_dma_copy_aligned(device, pay_off, buff_off, len))
1544                 goto err;
1545
1546         unmap = dmaengine_get_unmap_data(device->dev, 2, GFP_NOWAIT);
1547         if (!unmap)
1548                 goto err;
1549
1550         unmap->len = len;
1551         unmap->addr[0] = dma_map_page(device->dev, virt_to_page(offset),
1552                                       pay_off, len, DMA_TO_DEVICE);
1553         if (dma_mapping_error(device->dev, unmap->addr[0]))
1554                 goto err_get_unmap;
1555
1556         unmap->to_cnt = 1;
1557
1558         unmap->addr[1] = dma_map_page(device->dev, virt_to_page(buf),
1559                                       buff_off, len, DMA_FROM_DEVICE);
1560         if (dma_mapping_error(device->dev, unmap->addr[1]))
1561                 goto err_get_unmap;
1562
1563         unmap->from_cnt = 1;
1564
1565         txd = device->device_prep_dma_memcpy(chan, unmap->addr[1],
1566                                              unmap->addr[0], len,
1567                                              DMA_PREP_INTERRUPT);
1568         if (!txd)
1569                 goto err_get_unmap;
1570
1571         txd->callback_result = ntb_rx_copy_callback;
1572         txd->callback_param = entry;
1573         dma_set_unmap(txd, unmap);
1574
1575         cookie = dmaengine_submit(txd);
1576         if (dma_submit_error(cookie))
1577                 goto err_set_unmap;
1578
1579         dmaengine_unmap_put(unmap);
1580
1581         qp->last_cookie = cookie;
1582
1583         qp->rx_async++;
1584
1585         return 0;
1586
1587 err_set_unmap:
1588         dmaengine_unmap_put(unmap);
1589 err_get_unmap:
1590         dmaengine_unmap_put(unmap);
1591 err:
1592         return -ENXIO;
1593 }
1594
1595 static void ntb_async_rx(struct ntb_queue_entry *entry, void *offset)
1596 {
1597         struct ntb_transport_qp *qp = entry->qp;
1598         struct dma_chan *chan = qp->rx_dma_chan;
1599         int res;
1600
1601         if (!chan)
1602                 goto err;
1603
1604         if (entry->len < copy_bytes)
1605                 goto err;
1606
1607         res = ntb_async_rx_submit(entry, offset);
1608         if (res < 0)
1609                 goto err;
1610
1611         if (!entry->retries)
1612                 qp->rx_async++;
1613
1614         return;
1615
1616 err:
1617         ntb_memcpy_rx(entry, offset);
1618         qp->rx_memcpy++;
1619 }
1620
1621 static int ntb_process_rxc(struct ntb_transport_qp *qp)
1622 {
1623         struct ntb_payload_header *hdr;
1624         struct ntb_queue_entry *entry;
1625         void *offset;
1626
1627         offset = qp->rx_buff + qp->rx_max_frame * qp->rx_index;
1628         hdr = offset + qp->rx_max_frame - sizeof(struct ntb_payload_header);
1629
1630         dev_dbg(&qp->ndev->pdev->dev, "qp %d: RX ver %u len %d flags %x\n",
1631                 qp->qp_num, hdr->ver, hdr->len, hdr->flags);
1632
1633         if (!(hdr->flags & DESC_DONE_FLAG)) {
1634                 dev_dbg(&qp->ndev->pdev->dev, "done flag not set\n");
1635                 qp->rx_ring_empty++;
1636                 return -EAGAIN;
1637         }
1638
1639         if (hdr->flags & LINK_DOWN_FLAG) {
1640                 dev_dbg(&qp->ndev->pdev->dev, "link down flag set\n");
1641                 ntb_qp_link_down(qp);
1642                 hdr->flags = 0;
1643                 return -EAGAIN;
1644         }
1645
1646         if (hdr->ver != (u32)qp->rx_pkts) {
1647                 dev_dbg(&qp->ndev->pdev->dev,
1648                         "version mismatch, expected %llu - got %u\n",
1649                         qp->rx_pkts, hdr->ver);
1650                 qp->rx_err_ver++;
1651                 return -EIO;
1652         }
1653
1654         entry = ntb_list_mv(&qp->ntb_rx_q_lock, &qp->rx_pend_q, &qp->rx_post_q);
1655         if (!entry) {
1656                 dev_dbg(&qp->ndev->pdev->dev, "no receive buffer\n");
1657                 qp->rx_err_no_buf++;
1658                 return -EAGAIN;
1659         }
1660
1661         entry->rx_hdr = hdr;
1662         entry->rx_index = qp->rx_index;
1663
1664         if (hdr->len > entry->len) {
1665                 dev_dbg(&qp->ndev->pdev->dev,
1666                         "receive buffer overflow! Wanted %d got %d\n",
1667                         hdr->len, entry->len);
1668                 qp->rx_err_oflow++;
1669
1670                 entry->len = -EIO;
1671                 entry->flags |= DESC_DONE_FLAG;
1672
1673                 ntb_complete_rxc(qp);
1674         } else {
1675                 dev_dbg(&qp->ndev->pdev->dev,
1676                         "RX OK index %u ver %u size %d into buf size %d\n",
1677                         qp->rx_index, hdr->ver, hdr->len, entry->len);
1678
1679                 qp->rx_bytes += hdr->len;
1680                 qp->rx_pkts++;
1681
1682                 entry->len = hdr->len;
1683
1684                 ntb_async_rx(entry, offset);
1685         }
1686
1687         qp->rx_index++;
1688         qp->rx_index %= qp->rx_max_entry;
1689
1690         return 0;
1691 }
1692
1693 static void ntb_transport_rxc_db(unsigned long data)
1694 {
1695         struct ntb_transport_qp *qp = (void *)data;
1696         int rc, i;
1697
1698         dev_dbg(&qp->ndev->pdev->dev, "%s: doorbell %d received\n",
1699                 __func__, qp->qp_num);
1700
1701         /* Limit the number of packets processed in a single interrupt to
1702          * provide fairness to others
1703          */
1704         for (i = 0; i < qp->rx_max_entry; i++) {
1705                 rc = ntb_process_rxc(qp);
1706                 if (rc)
1707                         break;
1708         }
1709
1710         if (i && qp->rx_dma_chan)
1711                 dma_async_issue_pending(qp->rx_dma_chan);
1712
1713         if (i == qp->rx_max_entry) {
1714                 /* there is more work to do */
1715                 if (qp->active)
1716                         tasklet_schedule(&qp->rxc_db_work);
1717         } else if (ntb_db_read(qp->ndev) & BIT_ULL(qp->qp_num)) {
1718                 /* the doorbell bit is set: clear it */
1719                 ntb_db_clear(qp->ndev, BIT_ULL(qp->qp_num));
1720                 /* ntb_db_read ensures ntb_db_clear write is committed */
1721                 ntb_db_read(qp->ndev);
1722
1723                 /* an interrupt may have arrived between finishing
1724                  * ntb_process_rxc and clearing the doorbell bit:
1725                  * there might be some more work to do.
1726                  */
1727                 if (qp->active)
1728                         tasklet_schedule(&qp->rxc_db_work);
1729         }
1730 }
1731
1732 static void ntb_tx_copy_callback(void *data,
1733                                  const struct dmaengine_result *res)
1734 {
1735         struct ntb_queue_entry *entry = data;
1736         struct ntb_transport_qp *qp = entry->qp;
1737         struct ntb_payload_header __iomem *hdr = entry->tx_hdr;
1738
1739         /* we need to check DMA results if we are using DMA */
1740         if (res) {
1741                 enum dmaengine_tx_result dma_err = res->result;
1742
1743                 switch (dma_err) {
1744                 case DMA_TRANS_READ_FAILED:
1745                 case DMA_TRANS_WRITE_FAILED:
1746                         entry->errors++;
1747                         fallthrough;
1748                 case DMA_TRANS_ABORTED:
1749                 {
1750                         void __iomem *offset =
1751                                 qp->tx_mw + qp->tx_max_frame *
1752                                 entry->tx_index;
1753
1754                         /* resubmit via CPU */
1755                         ntb_memcpy_tx(entry, offset);
1756                         qp->tx_memcpy++;
1757                         return;
1758                 }
1759
1760                 case DMA_TRANS_NOERROR:
1761                 default:
1762                         break;
1763                 }
1764         }
1765
1766         iowrite32(entry->flags | DESC_DONE_FLAG, &hdr->flags);
1767
1768         if (qp->use_msi)
1769                 ntb_msi_peer_trigger(qp->ndev, PIDX, &qp->peer_msi_desc);
1770         else
1771                 ntb_peer_db_set(qp->ndev, BIT_ULL(qp->qp_num));
1772
1773         /* The entry length can only be zero if the packet is intended to be a
1774          * "link down" or similar.  Since no payload is being sent in these
1775          * cases, there is nothing to add to the completion queue.
1776          */
1777         if (entry->len > 0) {
1778                 qp->tx_bytes += entry->len;
1779
1780                 if (qp->tx_handler)
1781                         qp->tx_handler(qp, qp->cb_data, entry->cb_data,
1782                                        entry->len);
1783         }
1784
1785         ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q);
1786 }
1787
1788 static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset)
1789 {
1790 #ifdef ARCH_HAS_NOCACHE_UACCESS
1791         /*
1792          * Using non-temporal mov to improve performance on non-cached
1793          * writes, even though we aren't actually copying from user space.
1794          */
1795         __copy_from_user_inatomic_nocache(offset, entry->buf, entry->len);
1796 #else
1797         memcpy_toio(offset, entry->buf, entry->len);
1798 #endif
1799
1800         /* Ensure that the data is fully copied out before setting the flags */
1801         wmb();
1802
1803         ntb_tx_copy_callback(entry, NULL);
1804 }
1805
1806 static int ntb_async_tx_submit(struct ntb_transport_qp *qp,
1807                                struct ntb_queue_entry *entry)
1808 {
1809         struct dma_async_tx_descriptor *txd;
1810         struct dma_chan *chan = qp->tx_dma_chan;
1811         struct dma_device *device;
1812         size_t len = entry->len;
1813         void *buf = entry->buf;
1814         size_t dest_off, buff_off;
1815         struct dmaengine_unmap_data *unmap;
1816         dma_addr_t dest;
1817         dma_cookie_t cookie;
1818
1819         device = chan->device;
1820         dest = qp->tx_mw_dma_addr + qp->tx_max_frame * entry->tx_index;
1821         buff_off = (size_t)buf & ~PAGE_MASK;
1822         dest_off = (size_t)dest & ~PAGE_MASK;
1823
1824         if (!is_dma_copy_aligned(device, buff_off, dest_off, len))
1825                 goto err;
1826
1827         unmap = dmaengine_get_unmap_data(device->dev, 1, GFP_NOWAIT);
1828         if (!unmap)
1829                 goto err;
1830
1831         unmap->len = len;
1832         unmap->addr[0] = dma_map_page(device->dev, virt_to_page(buf),
1833                                       buff_off, len, DMA_TO_DEVICE);
1834         if (dma_mapping_error(device->dev, unmap->addr[0]))
1835                 goto err_get_unmap;
1836
1837         unmap->to_cnt = 1;
1838
1839         txd = device->device_prep_dma_memcpy(chan, dest, unmap->addr[0], len,
1840                                              DMA_PREP_INTERRUPT);
1841         if (!txd)
1842                 goto err_get_unmap;
1843
1844         txd->callback_result = ntb_tx_copy_callback;
1845         txd->callback_param = entry;
1846         dma_set_unmap(txd, unmap);
1847
1848         cookie = dmaengine_submit(txd);
1849         if (dma_submit_error(cookie))
1850                 goto err_set_unmap;
1851
1852         dmaengine_unmap_put(unmap);
1853
1854         dma_async_issue_pending(chan);
1855
1856         return 0;
1857 err_set_unmap:
1858         dmaengine_unmap_put(unmap);
1859 err_get_unmap:
1860         dmaengine_unmap_put(unmap);
1861 err:
1862         return -ENXIO;
1863 }
1864
1865 static void ntb_async_tx(struct ntb_transport_qp *qp,
1866                          struct ntb_queue_entry *entry)
1867 {
1868         struct ntb_payload_header __iomem *hdr;
1869         struct dma_chan *chan = qp->tx_dma_chan;
1870         void __iomem *offset;
1871         int res;
1872
1873         entry->tx_index = qp->tx_index;
1874         offset = qp->tx_mw + qp->tx_max_frame * entry->tx_index;
1875         hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
1876         entry->tx_hdr = hdr;
1877
1878         iowrite32(entry->len, &hdr->len);
1879         iowrite32((u32)qp->tx_pkts, &hdr->ver);
1880
1881         if (!chan)
1882                 goto err;
1883
1884         if (entry->len < copy_bytes)
1885                 goto err;
1886
1887         res = ntb_async_tx_submit(qp, entry);
1888         if (res < 0)
1889                 goto err;
1890
1891         if (!entry->retries)
1892                 qp->tx_async++;
1893
1894         return;
1895
1896 err:
1897         ntb_memcpy_tx(entry, offset);
1898         qp->tx_memcpy++;
1899 }
1900
1901 static int ntb_process_tx(struct ntb_transport_qp *qp,
1902                           struct ntb_queue_entry *entry)
1903 {
1904         if (!ntb_transport_tx_free_entry(qp)) {
1905                 qp->tx_ring_full++;
1906                 return -EAGAIN;
1907         }
1908
1909         if (entry->len > qp->tx_max_frame - sizeof(struct ntb_payload_header)) {
1910                 if (qp->tx_handler)
1911                         qp->tx_handler(qp, qp->cb_data, NULL, -EIO);
1912
1913                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1914                              &qp->tx_free_q);
1915                 return 0;
1916         }
1917
1918         ntb_async_tx(qp, entry);
1919
1920         qp->tx_index++;
1921         qp->tx_index %= qp->tx_max_entry;
1922
1923         qp->tx_pkts++;
1924
1925         return 0;
1926 }
1927
1928 static void ntb_send_link_down(struct ntb_transport_qp *qp)
1929 {
1930         struct pci_dev *pdev = qp->ndev->pdev;
1931         struct ntb_queue_entry *entry;
1932         int i, rc;
1933
1934         if (!qp->link_is_up)
1935                 return;
1936
1937         dev_info(&pdev->dev, "qp %d: Send Link Down\n", qp->qp_num);
1938
1939         for (i = 0; i < NTB_LINK_DOWN_TIMEOUT; i++) {
1940                 entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1941                 if (entry)
1942                         break;
1943                 msleep(100);
1944         }
1945
1946         if (!entry)
1947                 return;
1948
1949         entry->cb_data = NULL;
1950         entry->buf = NULL;
1951         entry->len = 0;
1952         entry->flags = LINK_DOWN_FLAG;
1953
1954         rc = ntb_process_tx(qp, entry);
1955         if (rc)
1956                 dev_err(&pdev->dev, "ntb: QP%d unable to send linkdown msg\n",
1957                         qp->qp_num);
1958
1959         ntb_qp_link_down_reset(qp);
1960 }
1961
1962 static bool ntb_dma_filter_fn(struct dma_chan *chan, void *node)
1963 {
1964         return dev_to_node(&chan->dev->device) == (int)(unsigned long)node;
1965 }
1966
1967 /**
1968  * ntb_transport_create_queue - Create a new NTB transport layer queue
1969  * @rx_handler: receive callback function
1970  * @tx_handler: transmit callback function
1971  * @event_handler: event callback function
1972  *
1973  * Create a new NTB transport layer queue and provide the queue with a callback
1974  * routine for both transmit and receive.  The receive callback routine will be
1975  * used to pass up data when the transport has received it on the queue.   The
1976  * transmit callback routine will be called when the transport has completed the
1977  * transmission of the data on the queue and the data is ready to be freed.
1978  *
1979  * RETURNS: pointer to newly created ntb_queue, NULL on error.
1980  */
1981 struct ntb_transport_qp *
1982 ntb_transport_create_queue(void *data, struct device *client_dev,
1983                            const struct ntb_queue_handlers *handlers)
1984 {
1985         struct ntb_dev *ndev;
1986         struct pci_dev *pdev;
1987         struct ntb_transport_ctx *nt;
1988         struct ntb_queue_entry *entry;
1989         struct ntb_transport_qp *qp;
1990         u64 qp_bit;
1991         unsigned int free_queue;
1992         dma_cap_mask_t dma_mask;
1993         int node;
1994         int i;
1995
1996         ndev = dev_ntb(client_dev->parent);
1997         pdev = ndev->pdev;
1998         nt = ndev->ctx;
1999
2000         node = dev_to_node(&ndev->dev);
2001
2002         free_queue = ffs(nt->qp_bitmap_free);
2003         if (!free_queue)
2004                 goto err;
2005
2006         /* decrement free_queue to make it zero based */
2007         free_queue--;
2008
2009         qp = &nt->qp_vec[free_queue];
2010         qp_bit = BIT_ULL(qp->qp_num);
2011
2012         nt->qp_bitmap_free &= ~qp_bit;
2013
2014         qp->cb_data = data;
2015         qp->rx_handler = handlers->rx_handler;
2016         qp->tx_handler = handlers->tx_handler;
2017         qp->event_handler = handlers->event_handler;
2018
2019         dma_cap_zero(dma_mask);
2020         dma_cap_set(DMA_MEMCPY, dma_mask);
2021
2022         if (use_dma) {
2023                 qp->tx_dma_chan =
2024                         dma_request_channel(dma_mask, ntb_dma_filter_fn,
2025                                             (void *)(unsigned long)node);
2026                 if (!qp->tx_dma_chan)
2027                         dev_info(&pdev->dev, "Unable to allocate TX DMA channel\n");
2028
2029                 qp->rx_dma_chan =
2030                         dma_request_channel(dma_mask, ntb_dma_filter_fn,
2031                                             (void *)(unsigned long)node);
2032                 if (!qp->rx_dma_chan)
2033                         dev_info(&pdev->dev, "Unable to allocate RX DMA channel\n");
2034         } else {
2035                 qp->tx_dma_chan = NULL;
2036                 qp->rx_dma_chan = NULL;
2037         }
2038
2039         qp->tx_mw_dma_addr = 0;
2040         if (qp->tx_dma_chan) {
2041                 qp->tx_mw_dma_addr =
2042                         dma_map_resource(qp->tx_dma_chan->device->dev,
2043                                          qp->tx_mw_phys, qp->tx_mw_size,
2044                                          DMA_FROM_DEVICE, 0);
2045                 if (dma_mapping_error(qp->tx_dma_chan->device->dev,
2046                                       qp->tx_mw_dma_addr)) {
2047                         qp->tx_mw_dma_addr = 0;
2048                         goto err1;
2049                 }
2050         }
2051
2052         dev_dbg(&pdev->dev, "Using %s memcpy for TX\n",
2053                 qp->tx_dma_chan ? "DMA" : "CPU");
2054
2055         dev_dbg(&pdev->dev, "Using %s memcpy for RX\n",
2056                 qp->rx_dma_chan ? "DMA" : "CPU");
2057
2058         for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
2059                 entry = kzalloc_node(sizeof(*entry), GFP_KERNEL, node);
2060                 if (!entry)
2061                         goto err1;
2062
2063                 entry->qp = qp;
2064                 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry,
2065                              &qp->rx_free_q);
2066         }
2067         qp->rx_alloc_entry = NTB_QP_DEF_NUM_ENTRIES;
2068
2069         for (i = 0; i < qp->tx_max_entry; i++) {
2070                 entry = kzalloc_node(sizeof(*entry), GFP_KERNEL, node);
2071                 if (!entry)
2072                         goto err2;
2073
2074                 entry->qp = qp;
2075                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
2076                              &qp->tx_free_q);
2077         }
2078
2079         ntb_db_clear(qp->ndev, qp_bit);
2080         ntb_db_clear_mask(qp->ndev, qp_bit);
2081
2082         dev_info(&pdev->dev, "NTB Transport QP %d created\n", qp->qp_num);
2083
2084         return qp;
2085
2086 err2:
2087         while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
2088                 kfree(entry);
2089 err1:
2090         qp->rx_alloc_entry = 0;
2091         while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
2092                 kfree(entry);
2093         if (qp->tx_mw_dma_addr)
2094                 dma_unmap_resource(qp->tx_dma_chan->device->dev,
2095                                    qp->tx_mw_dma_addr, qp->tx_mw_size,
2096                                    DMA_FROM_DEVICE, 0);
2097         if (qp->tx_dma_chan)
2098                 dma_release_channel(qp->tx_dma_chan);
2099         if (qp->rx_dma_chan)
2100                 dma_release_channel(qp->rx_dma_chan);
2101         nt->qp_bitmap_free |= qp_bit;
2102 err:
2103         return NULL;
2104 }
2105 EXPORT_SYMBOL_GPL(ntb_transport_create_queue);
2106
2107 /**
2108  * ntb_transport_free_queue - Frees NTB transport queue
2109  * @qp: NTB queue to be freed
2110  *
2111  * Frees NTB transport queue
2112  */
2113 void ntb_transport_free_queue(struct ntb_transport_qp *qp)
2114 {
2115         struct pci_dev *pdev;
2116         struct ntb_queue_entry *entry;
2117         u64 qp_bit;
2118
2119         if (!qp)
2120                 return;
2121
2122         pdev = qp->ndev->pdev;
2123
2124         qp->active = false;
2125
2126         if (qp->tx_dma_chan) {
2127                 struct dma_chan *chan = qp->tx_dma_chan;
2128                 /* Putting the dma_chan to NULL will force any new traffic to be
2129                  * processed by the CPU instead of the DAM engine
2130                  */
2131                 qp->tx_dma_chan = NULL;
2132
2133                 /* Try to be nice and wait for any queued DMA engine
2134                  * transactions to process before smashing it with a rock
2135                  */
2136                 dma_sync_wait(chan, qp->last_cookie);
2137                 dmaengine_terminate_all(chan);
2138
2139                 dma_unmap_resource(chan->device->dev,
2140                                    qp->tx_mw_dma_addr, qp->tx_mw_size,
2141                                    DMA_FROM_DEVICE, 0);
2142
2143                 dma_release_channel(chan);
2144         }
2145
2146         if (qp->rx_dma_chan) {
2147                 struct dma_chan *chan = qp->rx_dma_chan;
2148                 /* Putting the dma_chan to NULL will force any new traffic to be
2149                  * processed by the CPU instead of the DAM engine
2150                  */
2151                 qp->rx_dma_chan = NULL;
2152
2153                 /* Try to be nice and wait for any queued DMA engine
2154                  * transactions to process before smashing it with a rock
2155                  */
2156                 dma_sync_wait(chan, qp->last_cookie);
2157                 dmaengine_terminate_all(chan);
2158                 dma_release_channel(chan);
2159         }
2160
2161         qp_bit = BIT_ULL(qp->qp_num);
2162
2163         ntb_db_set_mask(qp->ndev, qp_bit);
2164         tasklet_kill(&qp->rxc_db_work);
2165
2166         cancel_delayed_work_sync(&qp->link_work);
2167
2168         qp->cb_data = NULL;
2169         qp->rx_handler = NULL;
2170         qp->tx_handler = NULL;
2171         qp->event_handler = NULL;
2172
2173         while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
2174                 kfree(entry);
2175
2176         while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_pend_q))) {
2177                 dev_warn(&pdev->dev, "Freeing item from non-empty rx_pend_q\n");
2178                 kfree(entry);
2179         }
2180
2181         while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_post_q))) {
2182                 dev_warn(&pdev->dev, "Freeing item from non-empty rx_post_q\n");
2183                 kfree(entry);
2184         }
2185
2186         while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
2187                 kfree(entry);
2188
2189         qp->transport->qp_bitmap_free |= qp_bit;
2190
2191         dev_info(&pdev->dev, "NTB Transport QP %d freed\n", qp->qp_num);
2192 }
2193 EXPORT_SYMBOL_GPL(ntb_transport_free_queue);
2194
2195 /**
2196  * ntb_transport_rx_remove - Dequeues enqueued rx packet
2197  * @qp: NTB queue to be freed
2198  * @len: pointer to variable to write enqueued buffers length
2199  *
2200  * Dequeues unused buffers from receive queue.  Should only be used during
2201  * shutdown of qp.
2202  *
2203  * RETURNS: NULL error value on error, or void* for success.
2204  */
2205 void *ntb_transport_rx_remove(struct ntb_transport_qp *qp, unsigned int *len)
2206 {
2207         struct ntb_queue_entry *entry;
2208         void *buf;
2209
2210         if (!qp || qp->client_ready)
2211                 return NULL;
2212
2213         entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_pend_q);
2214         if (!entry)
2215                 return NULL;
2216
2217         buf = entry->cb_data;
2218         *len = entry->len;
2219
2220         ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_free_q);
2221
2222         return buf;
2223 }
2224 EXPORT_SYMBOL_GPL(ntb_transport_rx_remove);
2225
2226 /**
2227  * ntb_transport_rx_enqueue - Enqueue a new NTB queue entry
2228  * @qp: NTB transport layer queue the entry is to be enqueued on
2229  * @cb: per buffer pointer for callback function to use
2230  * @data: pointer to data buffer that incoming packets will be copied into
2231  * @len: length of the data buffer
2232  *
2233  * Enqueue a new receive buffer onto the transport queue into which a NTB
2234  * payload can be received into.
2235  *
2236  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
2237  */
2238 int ntb_transport_rx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
2239                              unsigned int len)
2240 {
2241         struct ntb_queue_entry *entry;
2242
2243         if (!qp)
2244                 return -EINVAL;
2245
2246         entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q);
2247         if (!entry)
2248                 return -ENOMEM;
2249
2250         entry->cb_data = cb;
2251         entry->buf = data;
2252         entry->len = len;
2253         entry->flags = 0;
2254         entry->retries = 0;
2255         entry->errors = 0;
2256         entry->rx_index = 0;
2257
2258         ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_pend_q);
2259
2260         if (qp->active)
2261                 tasklet_schedule(&qp->rxc_db_work);
2262
2263         return 0;
2264 }
2265 EXPORT_SYMBOL_GPL(ntb_transport_rx_enqueue);
2266
2267 /**
2268  * ntb_transport_tx_enqueue - Enqueue a new NTB queue entry
2269  * @qp: NTB transport layer queue the entry is to be enqueued on
2270  * @cb: per buffer pointer for callback function to use
2271  * @data: pointer to data buffer that will be sent
2272  * @len: length of the data buffer
2273  *
2274  * Enqueue a new transmit buffer onto the transport queue from which a NTB
2275  * payload will be transmitted.  This assumes that a lock is being held to
2276  * serialize access to the qp.
2277  *
2278  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
2279  */
2280 int ntb_transport_tx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
2281                              unsigned int len)
2282 {
2283         struct ntb_queue_entry *entry;
2284         int rc;
2285
2286         if (!qp || !len)
2287                 return -EINVAL;
2288
2289         /* If the qp link is down already, just ignore. */
2290         if (!qp->link_is_up)
2291                 return 0;
2292
2293         entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
2294         if (!entry) {
2295                 qp->tx_err_no_buf++;
2296                 return -EBUSY;
2297         }
2298
2299         entry->cb_data = cb;
2300         entry->buf = data;
2301         entry->len = len;
2302         entry->flags = 0;
2303         entry->errors = 0;
2304         entry->retries = 0;
2305         entry->tx_index = 0;
2306
2307         rc = ntb_process_tx(qp, entry);
2308         if (rc)
2309                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
2310                              &qp->tx_free_q);
2311
2312         return rc;
2313 }
2314 EXPORT_SYMBOL_GPL(ntb_transport_tx_enqueue);
2315
2316 /**
2317  * ntb_transport_link_up - Notify NTB transport of client readiness to use queue
2318  * @qp: NTB transport layer queue to be enabled
2319  *
2320  * Notify NTB transport layer of client readiness to use queue
2321  */
2322 void ntb_transport_link_up(struct ntb_transport_qp *qp)
2323 {
2324         if (!qp)
2325                 return;
2326
2327         qp->client_ready = true;
2328
2329         if (qp->transport->link_is_up)
2330                 schedule_delayed_work(&qp->link_work, 0);
2331 }
2332 EXPORT_SYMBOL_GPL(ntb_transport_link_up);
2333
2334 /**
2335  * ntb_transport_link_down - Notify NTB transport to no longer enqueue data
2336  * @qp: NTB transport layer queue to be disabled
2337  *
2338  * Notify NTB transport layer of client's desire to no longer receive data on
2339  * transport queue specified.  It is the client's responsibility to ensure all
2340  * entries on queue are purged or otherwise handled appropriately.
2341  */
2342 void ntb_transport_link_down(struct ntb_transport_qp *qp)
2343 {
2344         int val;
2345
2346         if (!qp)
2347                 return;
2348
2349         qp->client_ready = false;
2350
2351         val = ntb_spad_read(qp->ndev, QP_LINKS);
2352
2353         ntb_peer_spad_write(qp->ndev, PIDX, QP_LINKS, val & ~BIT(qp->qp_num));
2354
2355         if (qp->link_is_up)
2356                 ntb_send_link_down(qp);
2357         else
2358                 cancel_delayed_work_sync(&qp->link_work);
2359 }
2360 EXPORT_SYMBOL_GPL(ntb_transport_link_down);
2361
2362 /**
2363  * ntb_transport_link_query - Query transport link state
2364  * @qp: NTB transport layer queue to be queried
2365  *
2366  * Query connectivity to the remote system of the NTB transport queue
2367  *
2368  * RETURNS: true for link up or false for link down
2369  */
2370 bool ntb_transport_link_query(struct ntb_transport_qp *qp)
2371 {
2372         if (!qp)
2373                 return false;
2374
2375         return qp->link_is_up;
2376 }
2377 EXPORT_SYMBOL_GPL(ntb_transport_link_query);
2378
2379 /**
2380  * ntb_transport_qp_num - Query the qp number
2381  * @qp: NTB transport layer queue to be queried
2382  *
2383  * Query qp number of the NTB transport queue
2384  *
2385  * RETURNS: a zero based number specifying the qp number
2386  */
2387 unsigned char ntb_transport_qp_num(struct ntb_transport_qp *qp)
2388 {
2389         if (!qp)
2390                 return 0;
2391
2392         return qp->qp_num;
2393 }
2394 EXPORT_SYMBOL_GPL(ntb_transport_qp_num);
2395
2396 /**
2397  * ntb_transport_max_size - Query the max payload size of a qp
2398  * @qp: NTB transport layer queue to be queried
2399  *
2400  * Query the maximum payload size permissible on the given qp
2401  *
2402  * RETURNS: the max payload size of a qp
2403  */
2404 unsigned int ntb_transport_max_size(struct ntb_transport_qp *qp)
2405 {
2406         unsigned int max_size;
2407         unsigned int copy_align;
2408         struct dma_chan *rx_chan, *tx_chan;
2409
2410         if (!qp)
2411                 return 0;
2412
2413         rx_chan = qp->rx_dma_chan;
2414         tx_chan = qp->tx_dma_chan;
2415
2416         copy_align = max(rx_chan ? rx_chan->device->copy_align : 0,
2417                          tx_chan ? tx_chan->device->copy_align : 0);
2418
2419         /* If DMA engine usage is possible, try to find the max size for that */
2420         max_size = qp->tx_max_frame - sizeof(struct ntb_payload_header);
2421         max_size = round_down(max_size, 1 << copy_align);
2422
2423         return max_size;
2424 }
2425 EXPORT_SYMBOL_GPL(ntb_transport_max_size);
2426
2427 unsigned int ntb_transport_tx_free_entry(struct ntb_transport_qp *qp)
2428 {
2429         unsigned int head = qp->tx_index;
2430         unsigned int tail = qp->remote_rx_info->entry;
2431
2432         return tail >= head ? tail - head : qp->tx_max_entry + tail - head;
2433 }
2434 EXPORT_SYMBOL_GPL(ntb_transport_tx_free_entry);
2435
2436 static void ntb_transport_doorbell_callback(void *data, int vector)
2437 {
2438         struct ntb_transport_ctx *nt = data;
2439         struct ntb_transport_qp *qp;
2440         u64 db_bits;
2441         unsigned int qp_num;
2442
2443         if (ntb_db_read(nt->ndev) & nt->msi_db_mask) {
2444                 ntb_transport_msi_peer_desc_changed(nt);
2445                 ntb_db_clear(nt->ndev, nt->msi_db_mask);
2446         }
2447
2448         db_bits = (nt->qp_bitmap & ~nt->qp_bitmap_free &
2449                    ntb_db_vector_mask(nt->ndev, vector));
2450
2451         while (db_bits) {
2452                 qp_num = __ffs(db_bits);
2453                 qp = &nt->qp_vec[qp_num];
2454
2455                 if (qp->active)
2456                         tasklet_schedule(&qp->rxc_db_work);
2457
2458                 db_bits &= ~BIT_ULL(qp_num);
2459         }
2460 }
2461
2462 static const struct ntb_ctx_ops ntb_transport_ops = {
2463         .link_event = ntb_transport_event_callback,
2464         .db_event = ntb_transport_doorbell_callback,
2465 };
2466
2467 static struct ntb_client ntb_transport_client = {
2468         .ops = {
2469                 .probe = ntb_transport_probe,
2470                 .remove = ntb_transport_free,
2471         },
2472 };
2473
2474 static int __init ntb_transport_init(void)
2475 {
2476         int rc;
2477
2478         pr_info("%s, version %s\n", NTB_TRANSPORT_DESC, NTB_TRANSPORT_VER);
2479
2480         if (debugfs_initialized())
2481                 nt_debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
2482
2483         rc = bus_register(&ntb_transport_bus);
2484         if (rc)
2485                 goto err_bus;
2486
2487         rc = ntb_register_client(&ntb_transport_client);
2488         if (rc)
2489                 goto err_client;
2490
2491         return 0;
2492
2493 err_client:
2494         bus_unregister(&ntb_transport_bus);
2495 err_bus:
2496         debugfs_remove_recursive(nt_debugfs_dir);
2497         return rc;
2498 }
2499 module_init(ntb_transport_init);
2500
2501 static void __exit ntb_transport_exit(void)
2502 {
2503         ntb_unregister_client(&ntb_transport_client);
2504         bus_unregister(&ntb_transport_bus);
2505         debugfs_remove_recursive(nt_debugfs_dir);
2506 }
2507 module_exit(ntb_transport_exit);