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 int 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         return 0;
 317 }
 318
 319 static struct bus_type ntb_transport_bus = {
 320         .name = "ntb_transport",
 321         .match = ntb_transport_bus_match,
 322         .probe = ntb_transport_bus_probe,
 323         .remove = ntb_transport_bus_remove,
 324 };
 325
 326 static LIST_HEAD(ntb_transport_list);
 327
 328 static int ntb_bus_init(struct ntb_transport_ctx *nt)
 329 {
 330         list_add_tail(&nt->entry, &ntb_transport_list);
 331         return 0;
 332 }
 333
 334 static void ntb_bus_remove(struct ntb_transport_ctx *nt)
 335 {
 336         struct ntb_transport_client_dev *client_dev, *cd;
 337
 338         list_for_each_entry_safe(client_dev, cd, &nt->client_devs, entry) {
 339                 dev_err(client_dev->dev.parent, "%s still attached to bus, removing\n",
 340                         dev_name(&client_dev->dev));
 341                 list_del(&client_dev->entry);
 342                 device_unregister(&client_dev->dev);
 343         }
 344
 345         list_del(&nt->entry);
 346 }
 347
 348 static void ntb_transport_client_release(struct device *dev)
 349 {
 350         struct ntb_transport_client_dev *client_dev;
 351
 352         client_dev = dev_client_dev(dev);
 353         kfree(client_dev);
 354 }
 355
 356 /**
 357  * ntb_transport_unregister_client_dev - Unregister NTB client device
 358  * @device_name: Name of NTB client device
 359  *
 360  * Unregister an NTB client device with the NTB transport layer
 361  */
 362 void ntb_transport_unregister_client_dev(char *device_name)
 363 {
 364         struct ntb_transport_client_dev *client, *cd;
 365         struct ntb_transport_ctx *nt;
 366
 367         list_for_each_entry(nt, &ntb_transport_list, entry)
 368                 list_for_each_entry_safe(client, cd, &nt->client_devs, entry)
 369                         if (!strncmp(dev_name(&client->dev), device_name,
 370                                      strlen(device_name))) {
 371                                 list_del(&client->entry);
 372                                 device_unregister(&client->dev);
 373                         }
 374 }
 375 EXPORT_SYMBOL_GPL(ntb_transport_unregister_client_dev);
 376
 377 /**
 378  * ntb_transport_register_client_dev - Register NTB client device
 379  * @device_name: Name of NTB client device
 380  *
 381  * Register an NTB client device with the NTB transport layer
 382  */
 383 int ntb_transport_register_client_dev(char *device_name)
 384 {
 385         struct ntb_transport_client_dev *client_dev;
 386         struct ntb_transport_ctx *nt;
 387         int node;
 388         int rc, i = 0;
 389
 390         if (list_empty(&ntb_transport_list))
 391                 return -ENODEV;
 392
 393         list_for_each_entry(nt, &ntb_transport_list, entry) {
 394                 struct device *dev;
 395
 396                 node = dev_to_node(&nt->ndev->dev);
 397
 398                 client_dev = kzalloc_node(sizeof(*client_dev),
 399                                           GFP_KERNEL, node);
 400                 if (!client_dev) {
 401                         rc = -ENOMEM;
 402                         goto err;
 403                 }
 404
 405                 dev = &client_dev->dev;
 406
 407                 /* setup and register client devices */
 408                 dev_set_name(dev, "%s%d", device_name, i);
 409                 dev->bus = &ntb_transport_bus;
 410                 dev->release = ntb_transport_client_release;
 411                 dev->parent = &nt->ndev->dev;
 412
 413                 rc = device_register(dev);
 414                 if (rc) {
 415                         kfree(client_dev);
 416                         goto err;
 417                 }
 418
 419                 list_add_tail(&client_dev->entry, &nt->client_devs);
 420                 i++;
 421         }
 422
 423         return 0;
 424
 425 err:
 426         ntb_transport_unregister_client_dev(device_name);
 427
 428         return rc;
 429 }
 430 EXPORT_SYMBOL_GPL(ntb_transport_register_client_dev);
 431
 432 /**
 433  * ntb_transport_register_client - Register NTB client driver
 434  * @drv: NTB client driver to be registered
 435  *
 436  * Register an NTB client driver with the NTB transport layer
 437  *
 438  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 439  */
 440 int ntb_transport_register_client(struct ntb_transport_client *drv)
 441 {
 442         drv->driver.bus = &ntb_transport_bus;
 443
 444         if (list_empty(&ntb_transport_list))
 445                 return -ENODEV;
 446
 447         return driver_register(&drv->driver);
 448 }
 449 EXPORT_SYMBOL_GPL(ntb_transport_register_client);
 450
 451 /**
 452  * ntb_transport_unregister_client - Unregister NTB client driver
 453  * @drv: NTB client driver to be unregistered
 454  *
 455  * Unregister an NTB client driver with the NTB transport layer
 456  *
 457  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 458  */
 459 void ntb_transport_unregister_client(struct ntb_transport_client *drv)
 460 {
 461         driver_unregister(&drv->driver);
 462 }
 463 EXPORT_SYMBOL_GPL(ntb_transport_unregister_client);
 464
 465 static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count,
 466                             loff_t *offp)
 467 {
 468         struct ntb_transport_qp *qp;
 469         char *buf;
 470         ssize_t ret, out_offset, out_count;
 471
 472         qp = filp->private_data;
 473
 474         if (!qp || !qp->link_is_up)
 475                 return 0;
 476
 477         out_count = 1000;
 478
 479         buf = kmalloc(out_count, GFP_KERNEL);
 480         if (!buf)
 481                 return -ENOMEM;
 482
 483         out_offset = 0;
 484         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 485                                "\nNTB QP stats:\n\n");
 486         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 487                                "rx_bytes - \t%llu\n", qp->rx_bytes);
 488         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 489                                "rx_pkts - \t%llu\n", qp->rx_pkts);
 490         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 491                                "rx_memcpy - \t%llu\n", qp->rx_memcpy);
 492         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 493                                "rx_async - \t%llu\n", qp->rx_async);
 494         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 495                                "rx_ring_empty - %llu\n", qp->rx_ring_empty);
 496         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 497                                "rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
 498         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 499                                "rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
 500         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 501                                "rx_err_ver - \t%llu\n", qp->rx_err_ver);
 502         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 503                                "rx_buff - \t0x%p\n", qp->rx_buff);
 504         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 505                                "rx_index - \t%u\n", qp->rx_index);
 506         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 507                                "rx_max_entry - \t%u\n", qp->rx_max_entry);
 508         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 509                                "rx_alloc_entry - \t%u\n\n", qp->rx_alloc_entry);
 510
 511         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 512                                "tx_bytes - \t%llu\n", qp->tx_bytes);
 513         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 514                                "tx_pkts - \t%llu\n", qp->tx_pkts);
 515         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 516                                "tx_memcpy - \t%llu\n", qp->tx_memcpy);
 517         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 518                                "tx_async - \t%llu\n", qp->tx_async);
 519         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 520                                "tx_ring_full - \t%llu\n", qp->tx_ring_full);
 521         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 522                                "tx_err_no_buf - %llu\n", qp->tx_err_no_buf);
 523         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 524                                "tx_mw - \t0x%p\n", qp->tx_mw);
 525         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 526                                "tx_index (H) - \t%u\n", qp->tx_index);
 527         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 528                                "RRI (T) - \t%u\n",
 529                                qp->remote_rx_info->entry);
 530         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 531                                "tx_max_entry - \t%u\n", qp->tx_max_entry);
 532         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 533                                "free tx - \t%u\n",
 534                                ntb_transport_tx_free_entry(qp));
 535
 536         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 537                                "\n");
 538         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 539                                "Using TX DMA - \t%s\n",
 540                                qp->tx_dma_chan ? "Yes" : "No");
 541         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 542                                "Using RX DMA - \t%s\n",
 543                                qp->rx_dma_chan ? "Yes" : "No");
 544         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 545                                "QP Link - \t%s\n",
 546                                qp->link_is_up ? "Up" : "Down");
 547         out_offset += scnprintf(buf + out_offset, out_count - out_offset,
 548                                "\n");
 549
 550         if (out_offset > out_count)
 551                 out_offset = out_count;
 552
 553         ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
 554         kfree(buf);
 555         return ret;
 556 }
 557
 558 static const struct file_operations ntb_qp_debugfs_stats = {
 559         .owner = THIS_MODULE,
 560         .open = simple_open,
 561         .read = debugfs_read,
 562 };
 563
 564 static void ntb_list_add(spinlock_t *lock, struct list_head *entry,
 565                          struct list_head *list)
 566 {
 567         unsigned long flags;
 568
 569         spin_lock_irqsave(lock, flags);
 570         list_add_tail(entry, list);
 571         spin_unlock_irqrestore(lock, flags);
 572 }
 573
 574 static struct ntb_queue_entry *ntb_list_rm(spinlock_t *lock,
 575                                            struct list_head *list)
 576 {
 577         struct ntb_queue_entry *entry;
 578         unsigned long flags;
 579
 580         spin_lock_irqsave(lock, flags);
 581         if (list_empty(list)) {
 582                 entry = NULL;
 583                 goto out;
 584         }
 585         entry = list_first_entry(list, struct ntb_queue_entry, entry);
 586         list_del(&entry->entry);
 587
 588 out:
 589         spin_unlock_irqrestore(lock, flags);
 590
 591         return entry;
 592 }
 593
 594 static struct ntb_queue_entry *ntb_list_mv(spinlock_t *lock,
 595                                            struct list_head *list,
 596                                            struct list_head *to_list)
 597 {
 598         struct ntb_queue_entry *entry;
 599         unsigned long flags;
 600
 601         spin_lock_irqsave(lock, flags);
 602
 603         if (list_empty(list)) {
 604                 entry = NULL;
 605         } else {
 606                 entry = list_first_entry(list, struct ntb_queue_entry, entry);
 607                 list_move_tail(&entry->entry, to_list);
 608         }
 609
 610         spin_unlock_irqrestore(lock, flags);
 611
 612         return entry;
 613 }
 614
 615 static int ntb_transport_setup_qp_mw(struct ntb_transport_ctx *nt,
 616                                      unsigned int qp_num)
 617 {
 618         struct ntb_transport_qp *qp = &nt->qp_vec[qp_num];
 619         struct ntb_transport_mw *mw;
 620         struct ntb_dev *ndev = nt->ndev;
 621         struct ntb_queue_entry *entry;
 622         unsigned int rx_size, num_qps_mw;
 623         unsigned int mw_num, mw_count, qp_count;
 624         unsigned int i;
 625         int node;
 626
 627         mw_count = nt->mw_count;
 628         qp_count = nt->qp_count;
 629
 630         mw_num = QP_TO_MW(nt, qp_num);
 631         mw = &nt->mw_vec[mw_num];
 632
 633         if (!mw->virt_addr)
 634                 return -ENOMEM;
 635
 636         if (mw_num < qp_count % mw_count)
 637                 num_qps_mw = qp_count / mw_count + 1;
 638         else
 639                 num_qps_mw = qp_count / mw_count;
 640
 641         rx_size = (unsigned int)mw->xlat_size / num_qps_mw;
 642         qp->rx_buff = mw->virt_addr + rx_size * (qp_num / mw_count);
 643         rx_size -= sizeof(struct ntb_rx_info);
 644
 645         qp->remote_rx_info = qp->rx_buff + rx_size;
 646
 647         /* Due to housekeeping, there must be atleast 2 buffs */
 648         qp->rx_max_frame = min(transport_mtu, rx_size / 2);
 649         qp->rx_max_entry = rx_size / qp->rx_max_frame;
 650         qp->rx_index = 0;
 651
 652         /*
 653          * Checking to see if we have more entries than the default.
 654          * We should add additional entries if that is the case so we
 655          * can be in sync with the transport frames.
 656          */
 657         node = dev_to_node(&ndev->dev);
 658         for (i = qp->rx_alloc_entry; i < qp->rx_max_entry; i++) {
 659                 entry = kzalloc_node(sizeof(*entry), GFP_KERNEL, node);
 660                 if (!entry)
 661                         return -ENOMEM;
 662
 663                 entry->qp = qp;
 664                 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry,
 665                              &qp->rx_free_q);
 666                 qp->rx_alloc_entry++;
 667         }
 668
 669         qp->remote_rx_info->entry = qp->rx_max_entry - 1;
 670
 671         /* setup the hdr offsets with 0's */
 672         for (i = 0; i < qp->rx_max_entry; i++) {
 673                 void *offset = (qp->rx_buff + qp->rx_max_frame * (i + 1) -
 674                                 sizeof(struct ntb_payload_header));
 675                 memset(offset, 0, sizeof(struct ntb_payload_header));
 676         }
 677
 678         qp->rx_pkts = 0;
 679         qp->tx_pkts = 0;
 680         qp->tx_index = 0;
 681
 682         return 0;
 683 }
 684
 685 static irqreturn_t ntb_transport_isr(int irq, void *dev)
 686 {
 687         struct ntb_transport_qp *qp = dev;
 688
 689         tasklet_schedule(&qp->rxc_db_work);
 690
 691         return IRQ_HANDLED;
 692 }
 693
 694 static void ntb_transport_setup_qp_peer_msi(struct ntb_transport_ctx *nt,
 695                                             unsigned int qp_num)
 696 {
 697         struct ntb_transport_qp *qp = &nt->qp_vec[qp_num];
 698         int spad = qp_num * 2 + nt->msi_spad_offset;
 699
 700         if (!nt->use_msi)
 701                 return;
 702
 703         if (spad >= ntb_spad_count(nt->ndev))
 704                 return;
 705
 706         qp->peer_msi_desc.addr_offset =
 707                 ntb_peer_spad_read(qp->ndev, PIDX, spad);
 708         qp->peer_msi_desc.data =
 709                 ntb_peer_spad_read(qp->ndev, PIDX, spad + 1);
 710
 711         dev_dbg(&qp->ndev->pdev->dev, "QP%d Peer MSI addr=%x data=%x\n",
 712                 qp_num, qp->peer_msi_desc.addr_offset, qp->peer_msi_desc.data);
 713
 714         if (qp->peer_msi_desc.addr_offset) {
 715                 qp->use_msi = true;
 716                 dev_info(&qp->ndev->pdev->dev,
 717                          "Using MSI interrupts for QP%d\n", qp_num);
 718         }
 719 }
 720
 721 static void ntb_transport_setup_qp_msi(struct ntb_transport_ctx *nt,
 722                                        unsigned int qp_num)
 723 {
 724         struct ntb_transport_qp *qp = &nt->qp_vec[qp_num];
 725         int spad = qp_num * 2 + nt->msi_spad_offset;
 726         int rc;
 727
 728         if (!nt->use_msi)
 729                 return;
 730
 731         if (spad >= ntb_spad_count(nt->ndev)) {
 732                 dev_warn_once(&qp->ndev->pdev->dev,
 733                               "Not enough SPADS to use MSI interrupts\n");
 734                 return;
 735         }
 736
 737         ntb_spad_write(qp->ndev, spad, 0);
 738         ntb_spad_write(qp->ndev, spad + 1, 0);
 739
 740         if (!qp->msi_irq) {
 741                 qp->msi_irq = ntbm_msi_request_irq(qp->ndev, ntb_transport_isr,
 742                                                    KBUILD_MODNAME, qp,
 743                                                    &qp->msi_desc);
 744                 if (qp->msi_irq < 0) {
 745                         dev_warn(&qp->ndev->pdev->dev,
 746                                  "Unable to allocate MSI interrupt for qp%d\n",
 747                                  qp_num);
 748                         return;
 749                 }
 750         }
 751
 752         rc = ntb_spad_write(qp->ndev, spad, qp->msi_desc.addr_offset);
 753         if (rc)
 754                 goto err_free_interrupt;
 755
 756         rc = ntb_spad_write(qp->ndev, spad + 1, qp->msi_desc.data);
 757         if (rc)
 758                 goto err_free_interrupt;
 759
 760         dev_dbg(&qp->ndev->pdev->dev, "QP%d MSI %d addr=%x data=%x\n",
 761                 qp_num, qp->msi_irq, qp->msi_desc.addr_offset,
 762                 qp->msi_desc.data);
 763
 764         return;
 765
 766 err_free_interrupt:
 767         devm_free_irq(&nt->ndev->dev, qp->msi_irq, qp);
 768 }
 769
 770 static void ntb_transport_msi_peer_desc_changed(struct ntb_transport_ctx *nt)
 771 {
 772         int i;
 773
 774         dev_dbg(&nt->ndev->pdev->dev, "Peer MSI descriptors changed");
 775
 776         for (i = 0; i < nt->qp_count; i++)
 777                 ntb_transport_setup_qp_peer_msi(nt, i);
 778 }
 779
 780 static void ntb_transport_msi_desc_changed(void *data)
 781 {
 782         struct ntb_transport_ctx *nt = data;
 783         int i;
 784
 785         dev_dbg(&nt->ndev->pdev->dev, "MSI descriptors changed");
 786
 787         for (i = 0; i < nt->qp_count; i++)
 788                 ntb_transport_setup_qp_msi(nt, i);
 789
 790         ntb_peer_db_set(nt->ndev, nt->msi_db_mask);
 791 }
 792
 793 static void ntb_free_mw(struct ntb_transport_ctx *nt, int num_mw)
 794 {
 795         struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
 796         struct pci_dev *pdev = nt->ndev->pdev;
 797
 798         if (!mw->virt_addr)
 799                 return;
 800
 801         ntb_mw_clear_trans(nt->ndev, PIDX, num_mw);
 802         dma_free_coherent(&pdev->dev, mw->alloc_size,
 803                           mw->alloc_addr, mw->dma_addr);
 804         mw->xlat_size = 0;
 805         mw->buff_size = 0;
 806         mw->alloc_size = 0;
 807         mw->alloc_addr = NULL;
 808         mw->virt_addr = NULL;
 809 }
 810
 811 static int ntb_alloc_mw_buffer(struct ntb_transport_mw *mw,
 812                                struct device *dma_dev, size_t align)
 813 {
 814         dma_addr_t dma_addr;
 815         void *alloc_addr, *virt_addr;
 816         int rc;
 817
 818         alloc_addr = dma_alloc_coherent(dma_dev, mw->alloc_size,
 819                                         &dma_addr, GFP_KERNEL);
 820         if (!alloc_addr) {
 821                 dev_err(dma_dev, "Unable to alloc MW buff of size %zu\n",
 822                         mw->alloc_size);
 823                 return -ENOMEM;
 824         }
 825         virt_addr = alloc_addr;
 826
 827         /*
 828          * we must ensure that the memory address allocated is BAR size
 829          * aligned in order for the XLAT register to take the value. This
 830          * is a requirement of the hardware. It is recommended to setup CMA
 831          * for BAR sizes equal or greater than 4MB.
 832          */
 833         if (!IS_ALIGNED(dma_addr, align)) {
 834                 if (mw->alloc_size > mw->buff_size) {
 835                         virt_addr = PTR_ALIGN(alloc_addr, align);
 836                         dma_addr = ALIGN(dma_addr, align);
 837                 } else {
 838                         rc = -ENOMEM;
 839                         goto err;
 840                 }
 841         }
 842
 843         mw->alloc_addr = alloc_addr;
 844         mw->virt_addr = virt_addr;
 845         mw->dma_addr = dma_addr;
 846
 847         return 0;
 848
 849 err:
 850         dma_free_coherent(dma_dev, mw->alloc_size, alloc_addr, dma_addr);
 851
 852         return rc;
 853 }
 854
 855 static int ntb_set_mw(struct ntb_transport_ctx *nt, int num_mw,
 856                       resource_size_t size)
 857 {
 858         struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
 859         struct pci_dev *pdev = nt->ndev->pdev;
 860         size_t xlat_size, buff_size;
 861         resource_size_t xlat_align;
 862         resource_size_t xlat_align_size;
 863         int rc;
 864
 865         if (!size)
 866                 return -EINVAL;
 867
 868         rc = ntb_mw_get_align(nt->ndev, PIDX, num_mw, &xlat_align,
 869                               &xlat_align_size, NULL);
 870         if (rc)
 871                 return rc;
 872
 873         xlat_size = round_up(size, xlat_align_size);
 874         buff_size = round_up(size, xlat_align);
 875
 876         /* No need to re-setup */
 877         if (mw->xlat_size == xlat_size)
 878                 return 0;
 879
 880         if (mw->buff_size)
 881                 ntb_free_mw(nt, num_mw);
 882
 883         /* Alloc memory for receiving data.  Must be aligned */
 884         mw->xlat_size = xlat_size;
 885         mw->buff_size = buff_size;
 886         mw->alloc_size = buff_size;
 887
 888         rc = ntb_alloc_mw_buffer(mw, &pdev->dev, xlat_align);
 889         if (rc) {
 890                 mw->alloc_size *= 2;
 891                 rc = ntb_alloc_mw_buffer(mw, &pdev->dev, xlat_align);
 892                 if (rc) {
 893                         dev_err(&pdev->dev,
 894                                 "Unable to alloc aligned MW buff\n");
 895                         mw->xlat_size = 0;
 896                         mw->buff_size = 0;
 897                         mw->alloc_size = 0;
 898                         return rc;
 899                 }
 900         }
 901
 902         /* Notify HW the memory location of the receive buffer */
 903         rc = ntb_mw_set_trans(nt->ndev, PIDX, num_mw, mw->dma_addr,
 904                               mw->xlat_size);
 905         if (rc) {
 906                 dev_err(&pdev->dev, "Unable to set mw%d translation", num_mw);
 907                 ntb_free_mw(nt, num_mw);
 908                 return -EIO;
 909         }
 910
 911         return 0;
 912 }
 913
 914 static void ntb_qp_link_down_reset(struct ntb_transport_qp *qp)
 915 {
 916         qp->link_is_up = false;
 917         qp->active = false;
 918
 919         qp->tx_index = 0;
 920         qp->rx_index = 0;
 921         qp->rx_bytes = 0;
 922         qp->rx_pkts = 0;
 923         qp->rx_ring_empty = 0;
 924         qp->rx_err_no_buf = 0;
 925         qp->rx_err_oflow = 0;
 926         qp->rx_err_ver = 0;
 927         qp->rx_memcpy = 0;
 928         qp->rx_async = 0;
 929         qp->tx_bytes = 0;
 930         qp->tx_pkts = 0;
 931         qp->tx_ring_full = 0;
 932         qp->tx_err_no_buf = 0;
 933         qp->tx_memcpy = 0;
 934         qp->tx_async = 0;
 935 }
 936
 937 static void ntb_qp_link_cleanup(struct ntb_transport_qp *qp)
 938 {
 939         struct ntb_transport_ctx *nt = qp->transport;
 940         struct pci_dev *pdev = nt->ndev->pdev;
 941
 942         dev_info(&pdev->dev, "qp %d: Link Cleanup\n", qp->qp_num);
 943
 944         cancel_delayed_work_sync(&qp->link_work);
 945         ntb_qp_link_down_reset(qp);
 946
 947         if (qp->event_handler)
 948                 qp->event_handler(qp->cb_data, qp->link_is_up);
 949 }
 950
 951 static void ntb_qp_link_cleanup_work(struct work_struct *work)
 952 {
 953         struct ntb_transport_qp *qp = container_of(work,
 954                                                    struct ntb_transport_qp,
 955                                                    link_cleanup);
 956         struct ntb_transport_ctx *nt = qp->transport;
 957
 958         ntb_qp_link_cleanup(qp);
 959
 960         if (nt->link_is_up)
 961                 schedule_delayed_work(&qp->link_work,
 962                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
 963 }
 964
 965 static void ntb_qp_link_down(struct ntb_transport_qp *qp)
 966 {
 967         schedule_work(&qp->link_cleanup);
 968 }
 969
 970 static void ntb_transport_link_cleanup(struct ntb_transport_ctx *nt)
 971 {
 972         struct ntb_transport_qp *qp;
 973         u64 qp_bitmap_alloc;
 974         unsigned int i, count;
 975
 976         qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
 977
 978         /* Pass along the info to any clients */
 979         for (i = 0; i < nt->qp_count; i++)
 980                 if (qp_bitmap_alloc & BIT_ULL(i)) {
 981                         qp = &nt->qp_vec[i];
 982                         ntb_qp_link_cleanup(qp);
 983                         cancel_work_sync(&qp->link_cleanup);
 984                         cancel_delayed_work_sync(&qp->link_work);
 985                 }
 986
 987         if (!nt->link_is_up)
 988                 cancel_delayed_work_sync(&nt->link_work);
 989
 990         for (i = 0; i < nt->mw_count; i++)
 991                 ntb_free_mw(nt, i);
 992
 993         /* The scratchpad registers keep the values if the remote side
 994          * goes down, blast them now to give them a sane value the next
 995          * time they are accessed
 996          */
 997         count = ntb_spad_count(nt->ndev);
 998         for (i = 0; i < count; i++)
 999                 ntb_spad_write(nt->ndev, i, 0);
1000 }
1001
1002 static void ntb_transport_link_cleanup_work(struct work_struct *work)
1003 {
1004         struct ntb_transport_ctx *nt =
1005                 container_of(work, struct ntb_transport_ctx, link_cleanup);
1006
1007         ntb_transport_link_cleanup(nt);
1008 }
1009
1010 static void ntb_transport_event_callback(void *data)
1011 {
1012         struct ntb_transport_ctx *nt = data;
1013
1014         if (ntb_link_is_up(nt->ndev, NULL, NULL) == 1)
1015                 schedule_delayed_work(&nt->link_work, 0);
1016         else
1017                 schedule_work(&nt->link_cleanup);
1018 }
1019
1020 static void ntb_transport_link_work(struct work_struct *work)
1021 {
1022         struct ntb_transport_ctx *nt =
1023                 container_of(work, struct ntb_transport_ctx, link_work.work);
1024         struct ntb_dev *ndev = nt->ndev;
1025         struct pci_dev *pdev = ndev->pdev;
1026         resource_size_t size;
1027         u32 val;
1028         int rc = 0, i, spad;
1029
1030         /* send the local info, in the opposite order of the way we read it */
1031
1032         if (nt->use_msi) {
1033                 rc = ntb_msi_setup_mws(ndev);
1034                 if (rc) {
1035                         dev_warn(&pdev->dev,
1036                                  "Failed to register MSI memory window: %d\n",
1037                                  rc);
1038                         nt->use_msi = false;
1039                 }
1040         }
1041
1042         for (i = 0; i < nt->qp_count; i++)
1043                 ntb_transport_setup_qp_msi(nt, i);
1044
1045         for (i = 0; i < nt->mw_count; i++) {
1046                 size = nt->mw_vec[i].phys_size;
1047
1048                 if (max_mw_size && size > max_mw_size)
1049                         size = max_mw_size;
1050
1051                 spad = MW0_SZ_HIGH + (i * 2);
1052                 ntb_peer_spad_write(ndev, PIDX, spad, upper_32_bits(size));
1053
1054                 spad = MW0_SZ_LOW + (i * 2);
1055                 ntb_peer_spad_write(ndev, PIDX, spad, lower_32_bits(size));
1056         }
1057
1058         ntb_peer_spad_write(ndev, PIDX, NUM_MWS, nt->mw_count);
1059
1060         ntb_peer_spad_write(ndev, PIDX, NUM_QPS, nt->qp_count);
1061
1062         ntb_peer_spad_write(ndev, PIDX, VERSION, NTB_TRANSPORT_VERSION);
1063
1064         /* Query the remote side for its info */
1065         val = ntb_spad_read(ndev, VERSION);
1066         dev_dbg(&pdev->dev, "Remote version = %d\n", val);
1067         if (val != NTB_TRANSPORT_VERSION)
1068                 goto out;
1069
1070         val = ntb_spad_read(ndev, NUM_QPS);
1071         dev_dbg(&pdev->dev, "Remote max number of qps = %d\n", val);
1072         if (val != nt->qp_count)
1073                 goto out;
1074
1075         val = ntb_spad_read(ndev, NUM_MWS);
1076         dev_dbg(&pdev->dev, "Remote number of mws = %d\n", val);
1077         if (val != nt->mw_count)
1078                 goto out;
1079
1080         for (i = 0; i < nt->mw_count; i++) {
1081                 u64 val64;
1082
1083                 val = ntb_spad_read(ndev, MW0_SZ_HIGH + (i * 2));
1084                 val64 = (u64)val << 32;
1085
1086                 val = ntb_spad_read(ndev, MW0_SZ_LOW + (i * 2));
1087                 val64 |= val;
1088
1089                 dev_dbg(&pdev->dev, "Remote MW%d size = %#llx\n", i, val64);
1090
1091                 rc = ntb_set_mw(nt, i, val64);
1092                 if (rc)
1093                         goto out1;
1094         }
1095
1096         nt->link_is_up = true;
1097
1098         for (i = 0; i < nt->qp_count; i++) {
1099                 struct ntb_transport_qp *qp = &nt->qp_vec[i];
1100
1101                 ntb_transport_setup_qp_mw(nt, i);
1102                 ntb_transport_setup_qp_peer_msi(nt, i);
1103
1104                 if (qp->client_ready)
1105                         schedule_delayed_work(&qp->link_work, 0);
1106         }
1107
1108         return;
1109
1110 out1:
1111         for (i = 0; i < nt->mw_count; i++)
1112                 ntb_free_mw(nt, i);
1113
1114         /* if there's an actual failure, we should just bail */
1115         if (rc < 0)
1116                 return;
1117
1118 out:
1119         if (ntb_link_is_up(ndev, NULL, NULL) == 1)
1120                 schedule_delayed_work(&nt->link_work,
1121                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
1122 }
1123
1124 static void ntb_qp_link_work(struct work_struct *work)
1125 {
1126         struct ntb_transport_qp *qp = container_of(work,
1127                                                    struct ntb_transport_qp,
1128                                                    link_work.work);
1129         struct pci_dev *pdev = qp->ndev->pdev;
1130         struct ntb_transport_ctx *nt = qp->transport;
1131         int val;
1132
1133         WARN_ON(!nt->link_is_up);
1134
1135         val = ntb_spad_read(nt->ndev, QP_LINKS);
1136
1137         ntb_peer_spad_write(nt->ndev, PIDX, QP_LINKS, val | BIT(qp->qp_num));
1138
1139         /* query remote spad for qp ready bits */
1140         dev_dbg_ratelimited(&pdev->dev, "Remote QP link status = %x\n", val);
1141
1142         /* See if the remote side is up */
1143         if (val & BIT(qp->qp_num)) {
1144                 dev_info(&pdev->dev, "qp %d: Link Up\n", qp->qp_num);
1145                 qp->link_is_up = true;
1146                 qp->active = true;
1147
1148                 if (qp->event_handler)
1149                         qp->event_handler(qp->cb_data, qp->link_is_up);
1150
1151                 if (qp->active)
1152                         tasklet_schedule(&qp->rxc_db_work);
1153         } else if (nt->link_is_up)
1154                 schedule_delayed_work(&qp->link_work,
1155                                       msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
1156 }
1157
1158 static int ntb_transport_init_queue(struct ntb_transport_ctx *nt,
1159                                     unsigned int qp_num)
1160 {
1161         struct ntb_transport_qp *qp;
1162         phys_addr_t mw_base;
1163         resource_size_t mw_size;
1164         unsigned int num_qps_mw, tx_size;
1165         unsigned int mw_num, mw_count, qp_count;
1166         u64 qp_offset;
1167
1168         mw_count = nt->mw_count;
1169         qp_count = nt->qp_count;
1170
1171         mw_num = QP_TO_MW(nt, qp_num);
1172
1173         qp = &nt->qp_vec[qp_num];
1174         qp->qp_num = qp_num;
1175         qp->transport = nt;
1176         qp->ndev = nt->ndev;
1177         qp->client_ready = false;
1178         qp->event_handler = NULL;
1179         ntb_qp_link_down_reset(qp);
1180
1181         if (mw_num < qp_count % mw_count)
1182                 num_qps_mw = qp_count / mw_count + 1;
1183         else
1184                 num_qps_mw = qp_count / mw_count;
1185
1186         mw_base = nt->mw_vec[mw_num].phys_addr;
1187         mw_size = nt->mw_vec[mw_num].phys_size;
1188
1189         if (max_mw_size && mw_size > max_mw_size)
1190                 mw_size = max_mw_size;
1191
1192         tx_size = (unsigned int)mw_size / num_qps_mw;
1193         qp_offset = tx_size * (qp_num / mw_count);
1194
1195         qp->tx_mw_size = tx_size;
1196         qp->tx_mw = nt->mw_vec[mw_num].vbase + qp_offset;
1197         if (!qp->tx_mw)
1198                 return -EINVAL;
1199
1200         qp->tx_mw_phys = mw_base + qp_offset;
1201         if (!qp->tx_mw_phys)
1202                 return -EINVAL;
1203
1204         tx_size -= sizeof(struct ntb_rx_info);
1205         qp->rx_info = qp->tx_mw + tx_size;
1206
1207         /* Due to housekeeping, there must be atleast 2 buffs */
1208         qp->tx_max_frame = min(transport_mtu, tx_size / 2);
1209         qp->tx_max_entry = tx_size / qp->tx_max_frame;
1210
1211         if (nt->debugfs_node_dir) {
1212                 char debugfs_name[4];
1213
1214                 snprintf(debugfs_name, 4, "qp%d", qp_num);
1215                 qp->debugfs_dir = debugfs_create_dir(debugfs_name,
1216                                                      nt->debugfs_node_dir);
1217
1218                 qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR,
1219                                                         qp->debugfs_dir, qp,
1220                                                         &ntb_qp_debugfs_stats);
1221         } else {
1222                 qp->debugfs_dir = NULL;
1223                 qp->debugfs_stats = NULL;
1224         }
1225
1226         INIT_DELAYED_WORK(&qp->link_work, ntb_qp_link_work);
1227         INIT_WORK(&qp->link_cleanup, ntb_qp_link_cleanup_work);
1228
1229         spin_lock_init(&qp->ntb_rx_q_lock);
1230         spin_lock_init(&qp->ntb_tx_free_q_lock);
1231
1232         INIT_LIST_HEAD(&qp->rx_post_q);
1233         INIT_LIST_HEAD(&qp->rx_pend_q);
1234         INIT_LIST_HEAD(&qp->rx_free_q);
1235         INIT_LIST_HEAD(&qp->tx_free_q);
1236
1237         tasklet_init(&qp->rxc_db_work, ntb_transport_rxc_db,
1238                      (unsigned long)qp);
1239
1240         return 0;
1241 }
1242
1243 static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev)
1244 {
1245         struct ntb_transport_ctx *nt;
1246         struct ntb_transport_mw *mw;
1247         unsigned int mw_count, qp_count, spad_count, max_mw_count_for_spads;
1248         u64 qp_bitmap;
1249         int node;
1250         int rc, i;
1251
1252         mw_count = ntb_peer_mw_count(ndev);
1253
1254         if (!ndev->ops->mw_set_trans) {
1255                 dev_err(&ndev->dev, "Inbound MW based NTB API is required\n");
1256                 return -EINVAL;
1257         }
1258
1259         if (ntb_db_is_unsafe(ndev))
1260                 dev_dbg(&ndev->dev,
1261                         "doorbell is unsafe, proceed anyway...\n");
1262         if (ntb_spad_is_unsafe(ndev))
1263                 dev_dbg(&ndev->dev,
1264                         "scratchpad is unsafe, proceed anyway...\n");
1265
1266         if (ntb_peer_port_count(ndev) != NTB_DEF_PEER_CNT)
1267                 dev_warn(&ndev->dev, "Multi-port NTB devices unsupported\n");
1268
1269         node = dev_to_node(&ndev->dev);
1270
1271         nt = kzalloc_node(sizeof(*nt), GFP_KERNEL, node);
1272         if (!nt)
1273                 return -ENOMEM;
1274
1275         nt->ndev = ndev;
1276
1277         /*
1278          * If we are using MSI, and have at least one extra memory window,
1279          * we will reserve the last MW for the MSI window.
1280          */
1281         if (use_msi && mw_count > 1) {
1282                 rc = ntb_msi_init(ndev, ntb_transport_msi_desc_changed);
1283                 if (!rc) {
1284                         mw_count -= 1;
1285                         nt->use_msi = true;
1286                 }
1287         }
1288
1289         spad_count = ntb_spad_count(ndev);
1290
1291         /* Limit the MW's based on the availability of scratchpads */
1292
1293         if (spad_count < NTB_TRANSPORT_MIN_SPADS) {
1294                 nt->mw_count = 0;
1295                 rc = -EINVAL;
1296                 goto err;
1297         }
1298
1299         max_mw_count_for_spads = (spad_count - MW0_SZ_HIGH) / 2;
1300         nt->mw_count = min(mw_count, max_mw_count_for_spads);
1301
1302         nt->msi_spad_offset = nt->mw_count * 2 + MW0_SZ_HIGH;
1303
1304         nt->mw_vec = kcalloc_node(mw_count, sizeof(*nt->mw_vec),
1305                                   GFP_KERNEL, node);
1306         if (!nt->mw_vec) {
1307                 rc = -ENOMEM;
1308                 goto err;
1309         }
1310
1311         for (i = 0; i < mw_count; i++) {
1312                 mw = &nt->mw_vec[i];
1313
1314                 rc = ntb_peer_mw_get_addr(ndev, i, &mw->phys_addr,
1315                                           &mw->phys_size);
1316                 if (rc)
1317                         goto err1;
1318
1319                 mw->vbase = ioremap_wc(mw->phys_addr, mw->phys_size);
1320                 if (!mw->vbase) {
1321                         rc = -ENOMEM;
1322                         goto err1;
1323                 }
1324
1325                 mw->buff_size = 0;
1326                 mw->xlat_size = 0;
1327                 mw->virt_addr = NULL;
1328                 mw->dma_addr = 0;
1329         }
1330
1331         qp_bitmap = ntb_db_valid_mask(ndev);
1332
1333         qp_count = ilog2(qp_bitmap);
1334         if (nt->use_msi) {
1335                 qp_count -= 1;
1336                 nt->msi_db_mask = 1 << qp_count;
1337                 ntb_db_clear_mask(ndev, nt->msi_db_mask);
1338         }
1339
1340         if (max_num_clients && max_num_clients < qp_count)
1341                 qp_count = max_num_clients;
1342         else if (nt->mw_count < qp_count)
1343                 qp_count = nt->mw_count;
1344
1345         qp_bitmap &= BIT_ULL(qp_count) - 1;
1346
1347         nt->qp_count = qp_count;
1348         nt->qp_bitmap = qp_bitmap;
1349         nt->qp_bitmap_free = qp_bitmap;
1350
1351         nt->qp_vec = kcalloc_node(qp_count, sizeof(*nt->qp_vec),
1352                                   GFP_KERNEL, node);
1353         if (!nt->qp_vec) {
1354                 rc = -ENOMEM;
1355                 goto err1;
1356         }
1357
1358         if (nt_debugfs_dir) {
1359                 nt->debugfs_node_dir =
1360                         debugfs_create_dir(pci_name(ndev->pdev),
1361                                            nt_debugfs_dir);
1362         }
1363
1364         for (i = 0; i < qp_count; i++) {
1365                 rc = ntb_transport_init_queue(nt, i);
1366                 if (rc)
1367                         goto err2;
1368         }
1369
1370         INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work);
1371         INIT_WORK(&nt->link_cleanup, ntb_transport_link_cleanup_work);
1372
1373         rc = ntb_set_ctx(ndev, nt, &ntb_transport_ops);
1374         if (rc)
1375                 goto err2;
1376
1377         INIT_LIST_HEAD(&nt->client_devs);
1378         rc = ntb_bus_init(nt);
1379         if (rc)
1380                 goto err3;
1381
1382         nt->link_is_up = false;
1383         ntb_link_enable(ndev, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
1384         ntb_link_event(ndev);
1385
1386         return 0;
1387
1388 err3:
1389         ntb_clear_ctx(ndev);
1390 err2:
1391         kfree(nt->qp_vec);
1392 err1:
1393         while (i--) {
1394                 mw = &nt->mw_vec[i];
1395                 iounmap(mw->vbase);
1396         }
1397         kfree(nt->mw_vec);
1398 err:
1399         kfree(nt);
1400         return rc;
1401 }
1402
1403 static void ntb_transport_free(struct ntb_client *self, struct ntb_dev *ndev)
1404 {
1405         struct ntb_transport_ctx *nt = ndev->ctx;
1406         struct ntb_transport_qp *qp;
1407         u64 qp_bitmap_alloc;
1408         int i;
1409
1410         ntb_transport_link_cleanup(nt);
1411         cancel_work_sync(&nt->link_cleanup);
1412         cancel_delayed_work_sync(&nt->link_work);
1413
1414         qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
1415
1416         /* verify that all the qp's are freed */
1417         for (i = 0; i < nt->qp_count; i++) {
1418                 qp = &nt->qp_vec[i];
1419                 if (qp_bitmap_alloc & BIT_ULL(i))
1420                         ntb_transport_free_queue(qp);
1421                 debugfs_remove_recursive(qp->debugfs_dir);
1422         }
1423
1424         ntb_link_disable(ndev);
1425         ntb_clear_ctx(ndev);
1426
1427         ntb_bus_remove(nt);
1428
1429         for (i = nt->mw_count; i--; ) {
1430                 ntb_free_mw(nt, i);
1431                 iounmap(nt->mw_vec[i].vbase);
1432         }
1433
1434         kfree(nt->qp_vec);
1435         kfree(nt->mw_vec);
1436         kfree(nt);
1437 }
1438
1439 static void ntb_complete_rxc(struct ntb_transport_qp *qp)
1440 {
1441         struct ntb_queue_entry *entry;
1442         void *cb_data;
1443         unsigned int len;
1444         unsigned long irqflags;
1445
1446         spin_lock_irqsave(&qp->ntb_rx_q_lock, irqflags);
1447
1448         while (!list_empty(&qp->rx_post_q)) {
1449                 entry = list_first_entry(&qp->rx_post_q,
1450                                          struct ntb_queue_entry, entry);
1451                 if (!(entry->flags & DESC_DONE_FLAG))
1452                         break;
1453
1454                 entry->rx_hdr->flags = 0;
1455                 iowrite32(entry->rx_index, &qp->rx_info->entry);
1456
1457                 cb_data = entry->cb_data;
1458                 len = entry->len;
1459
1460                 list_move_tail(&entry->entry, &qp->rx_free_q);
1461
1462                 spin_unlock_irqrestore(&qp->ntb_rx_q_lock, irqflags);
1463
1464                 if (qp->rx_handler && qp->client_ready)
1465                         qp->rx_handler(qp, qp->cb_data, cb_data, len);
1466
1467                 spin_lock_irqsave(&qp->ntb_rx_q_lock, irqflags);
1468         }
1469
1470         spin_unlock_irqrestore(&qp->ntb_rx_q_lock, irqflags);
1471 }
1472
1473 static void ntb_rx_copy_callback(void *data,
1474                                  const struct dmaengine_result *res)
1475 {
1476         struct ntb_queue_entry *entry = data;
1477
1478         /* we need to check DMA results if we are using DMA */
1479         if (res) {
1480                 enum dmaengine_tx_result dma_err = res->result;
1481
1482                 switch (dma_err) {
1483                 case DMA_TRANS_READ_FAILED:
1484                 case DMA_TRANS_WRITE_FAILED:
1485                         entry->errors++;
1486                         fallthrough;
1487                 case DMA_TRANS_ABORTED:
1488                 {
1489                         struct ntb_transport_qp *qp = entry->qp;
1490                         void *offset = qp->rx_buff + qp->rx_max_frame *
1491                                         qp->rx_index;
1492
1493                         ntb_memcpy_rx(entry, offset);
1494                         qp->rx_memcpy++;
1495                         return;
1496                 }
1497
1498                 case DMA_TRANS_NOERROR:
1499                 default:
1500                         break;
1501                 }
1502         }
1503
1504         entry->flags |= DESC_DONE_FLAG;
1505
1506         ntb_complete_rxc(entry->qp);
1507 }
1508
1509 static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void *offset)
1510 {
1511         void *buf = entry->buf;
1512         size_t len = entry->len;
1513
1514         memcpy(buf, offset, len);
1515
1516         /* Ensure that the data is fully copied out before clearing the flag */
1517         wmb();
1518
1519         ntb_rx_copy_callback(entry, NULL);
1520 }
1521
1522 static int ntb_async_rx_submit(struct ntb_queue_entry *entry, void *offset)
1523 {
1524         struct dma_async_tx_descriptor *txd;
1525         struct ntb_transport_qp *qp = entry->qp;
1526         struct dma_chan *chan = qp->rx_dma_chan;
1527         struct dma_device *device;
1528         size_t pay_off, buff_off, len;
1529         struct dmaengine_unmap_data *unmap;
1530         dma_cookie_t cookie;
1531         void *buf = entry->buf;
1532
1533         len = entry->len;
1534         device = chan->device;
1535         pay_off = (size_t)offset & ~PAGE_MASK;
1536         buff_off = (size_t)buf & ~PAGE_MASK;
1537
1538         if (!is_dma_copy_aligned(device, pay_off, buff_off, len))
1539                 goto err;
1540
1541         unmap = dmaengine_get_unmap_data(device->dev, 2, GFP_NOWAIT);
1542         if (!unmap)
1543                 goto err;
1544
1545         unmap->len = len;
1546         unmap->addr[0] = dma_map_page(device->dev, virt_to_page(offset),
1547                                       pay_off, len, DMA_TO_DEVICE);
1548         if (dma_mapping_error(device->dev, unmap->addr[0]))
1549                 goto err_get_unmap;
1550
1551         unmap->to_cnt = 1;
1552
1553         unmap->addr[1] = dma_map_page(device->dev, virt_to_page(buf),
1554                                       buff_off, len, DMA_FROM_DEVICE);
1555         if (dma_mapping_error(device->dev, unmap->addr[1]))
1556                 goto err_get_unmap;
1557
1558         unmap->from_cnt = 1;
1559
1560         txd = device->device_prep_dma_memcpy(chan, unmap->addr[1],
1561                                              unmap->addr[0], len,
1562                                              DMA_PREP_INTERRUPT);
1563         if (!txd)
1564                 goto err_get_unmap;
1565
1566         txd->callback_result = ntb_rx_copy_callback;
1567         txd->callback_param = entry;
1568         dma_set_unmap(txd, unmap);
1569
1570         cookie = dmaengine_submit(txd);
1571         if (dma_submit_error(cookie))
1572                 goto err_set_unmap;
1573
1574         dmaengine_unmap_put(unmap);
1575
1576         qp->last_cookie = cookie;
1577
1578         qp->rx_async++;
1579
1580         return 0;
1581
1582 err_set_unmap:
1583         dmaengine_unmap_put(unmap);
1584 err_get_unmap:
1585         dmaengine_unmap_put(unmap);
1586 err:
1587         return -ENXIO;
1588 }
1589
1590 static void ntb_async_rx(struct ntb_queue_entry *entry, void *offset)
1591 {
1592         struct ntb_transport_qp *qp = entry->qp;
1593         struct dma_chan *chan = qp->rx_dma_chan;
1594         int res;
1595
1596         if (!chan)
1597                 goto err;
1598
1599         if (entry->len < copy_bytes)
1600                 goto err;
1601
1602         res = ntb_async_rx_submit(entry, offset);
1603         if (res < 0)
1604                 goto err;
1605
1606         if (!entry->retries)
1607                 qp->rx_async++;
1608
1609         return;
1610
1611 err:
1612         ntb_memcpy_rx(entry, offset);
1613         qp->rx_memcpy++;
1614 }
1615
1616 static int ntb_process_rxc(struct ntb_transport_qp *qp)
1617 {
1618         struct ntb_payload_header *hdr;
1619         struct ntb_queue_entry *entry;
1620         void *offset;
1621
1622         offset = qp->rx_buff + qp->rx_max_frame * qp->rx_index;
1623         hdr = offset + qp->rx_max_frame - sizeof(struct ntb_payload_header);
1624
1625         dev_dbg(&qp->ndev->pdev->dev, "qp %d: RX ver %u len %d flags %x\n",
1626                 qp->qp_num, hdr->ver, hdr->len, hdr->flags);
1627
1628         if (!(hdr->flags & DESC_DONE_FLAG)) {
1629                 dev_dbg(&qp->ndev->pdev->dev, "done flag not set\n");
1630                 qp->rx_ring_empty++;
1631                 return -EAGAIN;
1632         }
1633
1634         if (hdr->flags & LINK_DOWN_FLAG) {
1635                 dev_dbg(&qp->ndev->pdev->dev, "link down flag set\n");
1636                 ntb_qp_link_down(qp);
1637                 hdr->flags = 0;
1638                 return -EAGAIN;
1639         }
1640
1641         if (hdr->ver != (u32)qp->rx_pkts) {
1642                 dev_dbg(&qp->ndev->pdev->dev,
1643                         "version mismatch, expected %llu - got %u\n",
1644                         qp->rx_pkts, hdr->ver);
1645                 qp->rx_err_ver++;
1646                 return -EIO;
1647         }
1648
1649         entry = ntb_list_mv(&qp->ntb_rx_q_lock, &qp->rx_pend_q, &qp->rx_post_q);
1650         if (!entry) {
1651                 dev_dbg(&qp->ndev->pdev->dev, "no receive buffer\n");
1652                 qp->rx_err_no_buf++;
1653                 return -EAGAIN;
1654         }
1655
1656         entry->rx_hdr = hdr;
1657         entry->rx_index = qp->rx_index;
1658
1659         if (hdr->len > entry->len) {
1660                 dev_dbg(&qp->ndev->pdev->dev,
1661                         "receive buffer overflow! Wanted %d got %d\n",
1662                         hdr->len, entry->len);
1663                 qp->rx_err_oflow++;
1664
1665                 entry->len = -EIO;
1666                 entry->flags |= DESC_DONE_FLAG;
1667
1668                 ntb_complete_rxc(qp);
1669         } else {
1670                 dev_dbg(&qp->ndev->pdev->dev,
1671                         "RX OK index %u ver %u size %d into buf size %d\n",
1672                         qp->rx_index, hdr->ver, hdr->len, entry->len);
1673
1674                 qp->rx_bytes += hdr->len;
1675                 qp->rx_pkts++;
1676
1677                 entry->len = hdr->len;
1678
1679                 ntb_async_rx(entry, offset);
1680         }
1681
1682         qp->rx_index++;
1683         qp->rx_index %= qp->rx_max_entry;
1684
1685         return 0;
1686 }
1687
1688 static void ntb_transport_rxc_db(unsigned long data)
1689 {
1690         struct ntb_transport_qp *qp = (void *)data;
1691         int rc, i;
1692
1693         dev_dbg(&qp->ndev->pdev->dev, "%s: doorbell %d received\n",
1694                 __func__, qp->qp_num);
1695
1696         /* Limit the number of packets processed in a single interrupt to
1697          * provide fairness to others
1698          */
1699         for (i = 0; i < qp->rx_max_entry; i++) {
1700                 rc = ntb_process_rxc(qp);
1701                 if (rc)
1702                         break;
1703         }
1704
1705         if (i && qp->rx_dma_chan)
1706                 dma_async_issue_pending(qp->rx_dma_chan);
1707
1708         if (i == qp->rx_max_entry) {
1709                 /* there is more work to do */
1710                 if (qp->active)
1711                         tasklet_schedule(&qp->rxc_db_work);
1712         } else if (ntb_db_read(qp->ndev) & BIT_ULL(qp->qp_num)) {
1713                 /* the doorbell bit is set: clear it */
1714                 ntb_db_clear(qp->ndev, BIT_ULL(qp->qp_num));
1715                 /* ntb_db_read ensures ntb_db_clear write is committed */
1716                 ntb_db_read(qp->ndev);
1717
1718                 /* an interrupt may have arrived between finishing
1719                  * ntb_process_rxc and clearing the doorbell bit:
1720                  * there might be some more work to do.
1721                  */
1722                 if (qp->active)
1723                         tasklet_schedule(&qp->rxc_db_work);
1724         }
1725 }
1726
1727 static void ntb_tx_copy_callback(void *data,
1728                                  const struct dmaengine_result *res)
1729 {
1730         struct ntb_queue_entry *entry = data;
1731         struct ntb_transport_qp *qp = entry->qp;
1732         struct ntb_payload_header __iomem *hdr = entry->tx_hdr;
1733
1734         /* we need to check DMA results if we are using DMA */
1735         if (res) {
1736                 enum dmaengine_tx_result dma_err = res->result;
1737
1738                 switch (dma_err) {
1739                 case DMA_TRANS_READ_FAILED:
1740                 case DMA_TRANS_WRITE_FAILED:
1741                         entry->errors++;
1742                         fallthrough;
1743                 case DMA_TRANS_ABORTED:
1744                 {
1745                         void __iomem *offset =
1746                                 qp->tx_mw + qp->tx_max_frame *
1747                                 entry->tx_index;
1748
1749                         /* resubmit via CPU */
1750                         ntb_memcpy_tx(entry, offset);
1751                         qp->tx_memcpy++;
1752                         return;
1753                 }
1754
1755                 case DMA_TRANS_NOERROR:
1756                 default:
1757                         break;
1758                 }
1759         }
1760
1761         iowrite32(entry->flags | DESC_DONE_FLAG, &hdr->flags);
1762
1763         if (qp->use_msi)
1764                 ntb_msi_peer_trigger(qp->ndev, PIDX, &qp->peer_msi_desc);
1765         else
1766                 ntb_peer_db_set(qp->ndev, BIT_ULL(qp->qp_num));
1767
1768         /* The entry length can only be zero if the packet is intended to be a
1769          * "link down" or similar.  Since no payload is being sent in these
1770          * cases, there is nothing to add to the completion queue.
1771          */
1772         if (entry->len > 0) {
1773                 qp->tx_bytes += entry->len;
1774
1775                 if (qp->tx_handler)
1776                         qp->tx_handler(qp, qp->cb_data, entry->cb_data,
1777                                        entry->len);
1778         }
1779
1780         ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q);
1781 }
1782
1783 static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset)
1784 {
1785 #ifdef ARCH_HAS_NOCACHE_UACCESS
1786         /*
1787          * Using non-temporal mov to improve performance on non-cached
1788          * writes, even though we aren't actually copying from user space.
1789          */
1790         __copy_from_user_inatomic_nocache(offset, entry->buf, entry->len);
1791 #else
1792         memcpy_toio(offset, entry->buf, entry->len);
1793 #endif
1794
1795         /* Ensure that the data is fully copied out before setting the flags */
1796         wmb();
1797
1798         ntb_tx_copy_callback(entry, NULL);
1799 }
1800
1801 static int ntb_async_tx_submit(struct ntb_transport_qp *qp,
1802                                struct ntb_queue_entry *entry)
1803 {
1804         struct dma_async_tx_descriptor *txd;
1805         struct dma_chan *chan = qp->tx_dma_chan;
1806         struct dma_device *device;
1807         size_t len = entry->len;
1808         void *buf = entry->buf;
1809         size_t dest_off, buff_off;
1810         struct dmaengine_unmap_data *unmap;
1811         dma_addr_t dest;
1812         dma_cookie_t cookie;
1813
1814         device = chan->device;
1815         dest = qp->tx_mw_dma_addr + qp->tx_max_frame * entry->tx_index;
1816         buff_off = (size_t)buf & ~PAGE_MASK;
1817         dest_off = (size_t)dest & ~PAGE_MASK;
1818
1819         if (!is_dma_copy_aligned(device, buff_off, dest_off, len))
1820                 goto err;
1821
1822         unmap = dmaengine_get_unmap_data(device->dev, 1, GFP_NOWAIT);
1823         if (!unmap)
1824                 goto err;
1825
1826         unmap->len = len;
1827         unmap->addr[0] = dma_map_page(device->dev, virt_to_page(buf),
1828                                       buff_off, len, DMA_TO_DEVICE);
1829         if (dma_mapping_error(device->dev, unmap->addr[0]))
1830                 goto err_get_unmap;
1831
1832         unmap->to_cnt = 1;
1833
1834         txd = device->device_prep_dma_memcpy(chan, dest, unmap->addr[0], len,
1835                                              DMA_PREP_INTERRUPT);
1836         if (!txd)
1837                 goto err_get_unmap;
1838
1839         txd->callback_result = ntb_tx_copy_callback;
1840         txd->callback_param = entry;
1841         dma_set_unmap(txd, unmap);
1842
1843         cookie = dmaengine_submit(txd);
1844         if (dma_submit_error(cookie))
1845                 goto err_set_unmap;
1846
1847         dmaengine_unmap_put(unmap);
1848
1849         dma_async_issue_pending(chan);
1850
1851         return 0;
1852 err_set_unmap:
1853         dmaengine_unmap_put(unmap);
1854 err_get_unmap:
1855         dmaengine_unmap_put(unmap);
1856 err:
1857         return -ENXIO;
1858 }
1859
1860 static void ntb_async_tx(struct ntb_transport_qp *qp,
1861                          struct ntb_queue_entry *entry)
1862 {
1863         struct ntb_payload_header __iomem *hdr;
1864         struct dma_chan *chan = qp->tx_dma_chan;
1865         void __iomem *offset;
1866         int res;
1867
1868         entry->tx_index = qp->tx_index;
1869         offset = qp->tx_mw + qp->tx_max_frame * entry->tx_index;
1870         hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
1871         entry->tx_hdr = hdr;
1872
1873         iowrite32(entry->len, &hdr->len);
1874         iowrite32((u32)qp->tx_pkts, &hdr->ver);
1875
1876         if (!chan)
1877                 goto err;
1878
1879         if (entry->len < copy_bytes)
1880                 goto err;
1881
1882         res = ntb_async_tx_submit(qp, entry);
1883         if (res < 0)
1884                 goto err;
1885
1886         if (!entry->retries)
1887                 qp->tx_async++;
1888
1889         return;
1890
1891 err:
1892         ntb_memcpy_tx(entry, offset);
1893         qp->tx_memcpy++;
1894 }
1895
1896 static int ntb_process_tx(struct ntb_transport_qp *qp,
1897                           struct ntb_queue_entry *entry)
1898 {
1899         if (qp->tx_index == qp->remote_rx_info->entry) {
1900                 qp->tx_ring_full++;
1901                 return -EAGAIN;
1902         }
1903
1904         if (entry->len > qp->tx_max_frame - sizeof(struct ntb_payload_header)) {
1905                 if (qp->tx_handler)
1906                         qp->tx_handler(qp, qp->cb_data, NULL, -EIO);
1907
1908                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1909                              &qp->tx_free_q);
1910                 return 0;
1911         }
1912
1913         ntb_async_tx(qp, entry);
1914
1915         qp->tx_index++;
1916         qp->tx_index %= qp->tx_max_entry;
1917
1918         qp->tx_pkts++;
1919
1920         return 0;
1921 }
1922
1923 static void ntb_send_link_down(struct ntb_transport_qp *qp)
1924 {
1925         struct pci_dev *pdev = qp->ndev->pdev;
1926         struct ntb_queue_entry *entry;
1927         int i, rc;
1928
1929         if (!qp->link_is_up)
1930                 return;
1931
1932         dev_info(&pdev->dev, "qp %d: Send Link Down\n", qp->qp_num);
1933
1934         for (i = 0; i < NTB_LINK_DOWN_TIMEOUT; i++) {
1935                 entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1936                 if (entry)
1937                         break;
1938                 msleep(100);
1939         }
1940
1941         if (!entry)
1942                 return;
1943
1944         entry->cb_data = NULL;
1945         entry->buf = NULL;
1946         entry->len = 0;
1947         entry->flags = LINK_DOWN_FLAG;
1948
1949         rc = ntb_process_tx(qp, entry);
1950         if (rc)
1951                 dev_err(&pdev->dev, "ntb: QP%d unable to send linkdown msg\n",
1952                         qp->qp_num);
1953
1954         ntb_qp_link_down_reset(qp);
1955 }
1956
1957 static bool ntb_dma_filter_fn(struct dma_chan *chan, void *node)
1958 {
1959         return dev_to_node(&chan->dev->device) == (int)(unsigned long)node;
1960 }
1961
1962 /**
1963  * ntb_transport_create_queue - Create a new NTB transport layer queue
1964  * @rx_handler: receive callback function
1965  * @tx_handler: transmit callback function
1966  * @event_handler: event callback function
1967  *
1968  * Create a new NTB transport layer queue and provide the queue with a callback
1969  * routine for both transmit and receive.  The receive callback routine will be
1970  * used to pass up data when the transport has received it on the queue.   The
1971  * transmit callback routine will be called when the transport has completed the
1972  * transmission of the data on the queue and the data is ready to be freed.
1973  *
1974  * RETURNS: pointer to newly created ntb_queue, NULL on error.
1975  */
1976 struct ntb_transport_qp *
1977 ntb_transport_create_queue(void *data, struct device *client_dev,
1978                            const struct ntb_queue_handlers *handlers)
1979 {
1980         struct ntb_dev *ndev;
1981         struct pci_dev *pdev;
1982         struct ntb_transport_ctx *nt;
1983         struct ntb_queue_entry *entry;
1984         struct ntb_transport_qp *qp;
1985         u64 qp_bit;
1986         unsigned int free_queue;
1987         dma_cap_mask_t dma_mask;
1988         int node;
1989         int i;
1990
1991         ndev = dev_ntb(client_dev->parent);
1992         pdev = ndev->pdev;
1993         nt = ndev->ctx;
1994
1995         node = dev_to_node(&ndev->dev);
1996
1997         free_queue = ffs(nt->qp_bitmap_free);
1998         if (!free_queue)
1999                 goto err;
2000
2001         /* decrement free_queue to make it zero based */
2002         free_queue--;
2003
2004         qp = &nt->qp_vec[free_queue];
2005         qp_bit = BIT_ULL(qp->qp_num);
2006
2007         nt->qp_bitmap_free &= ~qp_bit;
2008
2009         qp->cb_data = data;
2010         qp->rx_handler = handlers->rx_handler;
2011         qp->tx_handler = handlers->tx_handler;
2012         qp->event_handler = handlers->event_handler;
2013
2014         dma_cap_zero(dma_mask);
2015         dma_cap_set(DMA_MEMCPY, dma_mask);
2016
2017         if (use_dma) {
2018                 qp->tx_dma_chan =
2019                         dma_request_channel(dma_mask, ntb_dma_filter_fn,
2020                                             (void *)(unsigned long)node);
2021                 if (!qp->tx_dma_chan)
2022                         dev_info(&pdev->dev, "Unable to allocate TX DMA channel\n");
2023
2024                 qp->rx_dma_chan =
2025                         dma_request_channel(dma_mask, ntb_dma_filter_fn,
2026                                             (void *)(unsigned long)node);
2027                 if (!qp->rx_dma_chan)
2028                         dev_info(&pdev->dev, "Unable to allocate RX DMA channel\n");
2029         } else {
2030                 qp->tx_dma_chan = NULL;
2031                 qp->rx_dma_chan = NULL;
2032         }
2033
2034         qp->tx_mw_dma_addr = 0;
2035         if (qp->tx_dma_chan) {
2036                 qp->tx_mw_dma_addr =
2037                         dma_map_resource(qp->tx_dma_chan->device->dev,
2038                                          qp->tx_mw_phys, qp->tx_mw_size,
2039                                          DMA_FROM_DEVICE, 0);
2040                 if (dma_mapping_error(qp->tx_dma_chan->device->dev,
2041                                       qp->tx_mw_dma_addr)) {
2042                         qp->tx_mw_dma_addr = 0;
2043                         goto err1;
2044                 }
2045         }
2046
2047         dev_dbg(&pdev->dev, "Using %s memcpy for TX\n",
2048                 qp->tx_dma_chan ? "DMA" : "CPU");
2049
2050         dev_dbg(&pdev->dev, "Using %s memcpy for RX\n",
2051                 qp->rx_dma_chan ? "DMA" : "CPU");
2052
2053         for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
2054                 entry = kzalloc_node(sizeof(*entry), GFP_KERNEL, node);
2055                 if (!entry)
2056                         goto err1;
2057
2058                 entry->qp = qp;
2059                 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry,
2060                              &qp->rx_free_q);
2061         }
2062         qp->rx_alloc_entry = NTB_QP_DEF_NUM_ENTRIES;
2063
2064         for (i = 0; i < qp->tx_max_entry; i++) {
2065                 entry = kzalloc_node(sizeof(*entry), GFP_KERNEL, node);
2066                 if (!entry)
2067                         goto err2;
2068
2069                 entry->qp = qp;
2070                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
2071                              &qp->tx_free_q);
2072         }
2073
2074         ntb_db_clear(qp->ndev, qp_bit);
2075         ntb_db_clear_mask(qp->ndev, qp_bit);
2076
2077         dev_info(&pdev->dev, "NTB Transport QP %d created\n", qp->qp_num);
2078
2079         return qp;
2080
2081 err2:
2082         while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
2083                 kfree(entry);
2084 err1:
2085         qp->rx_alloc_entry = 0;
2086         while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
2087                 kfree(entry);
2088         if (qp->tx_mw_dma_addr)
2089                 dma_unmap_resource(qp->tx_dma_chan->device->dev,
2090                                    qp->tx_mw_dma_addr, qp->tx_mw_size,
2091                                    DMA_FROM_DEVICE, 0);
2092         if (qp->tx_dma_chan)
2093                 dma_release_channel(qp->tx_dma_chan);
2094         if (qp->rx_dma_chan)
2095                 dma_release_channel(qp->rx_dma_chan);
2096         nt->qp_bitmap_free |= qp_bit;
2097 err:
2098         return NULL;
2099 }
2100 EXPORT_SYMBOL_GPL(ntb_transport_create_queue);
2101
2102 /**
2103  * ntb_transport_free_queue - Frees NTB transport queue
2104  * @qp: NTB queue to be freed
2105  *
2106  * Frees NTB transport queue
2107  */
2108 void ntb_transport_free_queue(struct ntb_transport_qp *qp)
2109 {
2110         struct pci_dev *pdev;
2111         struct ntb_queue_entry *entry;
2112         u64 qp_bit;
2113
2114         if (!qp)
2115                 return;
2116
2117         pdev = qp->ndev->pdev;
2118
2119         qp->active = false;
2120
2121         if (qp->tx_dma_chan) {
2122                 struct dma_chan *chan = qp->tx_dma_chan;
2123                 /* Putting the dma_chan to NULL will force any new traffic to be
2124                  * processed by the CPU instead of the DAM engine
2125                  */
2126                 qp->tx_dma_chan = NULL;
2127
2128                 /* Try to be nice and wait for any queued DMA engine
2129                  * transactions to process before smashing it with a rock
2130                  */
2131                 dma_sync_wait(chan, qp->last_cookie);
2132                 dmaengine_terminate_all(chan);
2133
2134                 dma_unmap_resource(chan->device->dev,
2135                                    qp->tx_mw_dma_addr, qp->tx_mw_size,
2136                                    DMA_FROM_DEVICE, 0);
2137
2138                 dma_release_channel(chan);
2139         }
2140
2141         if (qp->rx_dma_chan) {
2142                 struct dma_chan *chan = qp->rx_dma_chan;
2143                 /* Putting the dma_chan to NULL will force any new traffic to be
2144                  * processed by the CPU instead of the DAM engine
2145                  */
2146                 qp->rx_dma_chan = NULL;
2147
2148                 /* Try to be nice and wait for any queued DMA engine
2149                  * transactions to process before smashing it with a rock
2150                  */
2151                 dma_sync_wait(chan, qp->last_cookie);
2152                 dmaengine_terminate_all(chan);
2153                 dma_release_channel(chan);
2154         }
2155
2156         qp_bit = BIT_ULL(qp->qp_num);
2157
2158         ntb_db_set_mask(qp->ndev, qp_bit);
2159         tasklet_kill(&qp->rxc_db_work);
2160
2161         cancel_delayed_work_sync(&qp->link_work);
2162
2163         qp->cb_data = NULL;
2164         qp->rx_handler = NULL;
2165         qp->tx_handler = NULL;
2166         qp->event_handler = NULL;
2167
2168         while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
2169                 kfree(entry);
2170
2171         while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_pend_q))) {
2172                 dev_warn(&pdev->dev, "Freeing item from non-empty rx_pend_q\n");
2173                 kfree(entry);
2174         }
2175
2176         while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_post_q))) {
2177                 dev_warn(&pdev->dev, "Freeing item from non-empty rx_post_q\n");
2178                 kfree(entry);
2179         }
2180
2181         while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
2182                 kfree(entry);
2183
2184         qp->transport->qp_bitmap_free |= qp_bit;
2185
2186         dev_info(&pdev->dev, "NTB Transport QP %d freed\n", qp->qp_num);
2187 }
2188 EXPORT_SYMBOL_GPL(ntb_transport_free_queue);
2189
2190 /**
2191  * ntb_transport_rx_remove - Dequeues enqueued rx packet
2192  * @qp: NTB queue to be freed
2193  * @len: pointer to variable to write enqueued buffers length
2194  *
2195  * Dequeues unused buffers from receive queue.  Should only be used during
2196  * shutdown of qp.
2197  *
2198  * RETURNS: NULL error value on error, or void* for success.
2199  */
2200 void *ntb_transport_rx_remove(struct ntb_transport_qp *qp, unsigned int *len)
2201 {
2202         struct ntb_queue_entry *entry;
2203         void *buf;
2204
2205         if (!qp || qp->client_ready)
2206                 return NULL;
2207
2208         entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_pend_q);
2209         if (!entry)
2210                 return NULL;
2211
2212         buf = entry->cb_data;
2213         *len = entry->len;
2214
2215         ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_free_q);
2216
2217         return buf;
2218 }
2219 EXPORT_SYMBOL_GPL(ntb_transport_rx_remove);
2220
2221 /**
2222  * ntb_transport_rx_enqueue - Enqueue a new NTB queue entry
2223  * @qp: NTB transport layer queue the entry is to be enqueued on
2224  * @cb: per buffer pointer for callback function to use
2225  * @data: pointer to data buffer that incoming packets will be copied into
2226  * @len: length of the data buffer
2227  *
2228  * Enqueue a new receive buffer onto the transport queue into which a NTB
2229  * payload can be received into.
2230  *
2231  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
2232  */
2233 int ntb_transport_rx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
2234                              unsigned int len)
2235 {
2236         struct ntb_queue_entry *entry;
2237
2238         if (!qp)
2239                 return -EINVAL;
2240
2241         entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q);
2242         if (!entry)
2243                 return -ENOMEM;
2244
2245         entry->cb_data = cb;
2246         entry->buf = data;
2247         entry->len = len;
2248         entry->flags = 0;
2249         entry->retries = 0;
2250         entry->errors = 0;
2251         entry->rx_index = 0;
2252
2253         ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_pend_q);
2254
2255         if (qp->active)
2256                 tasklet_schedule(&qp->rxc_db_work);
2257
2258         return 0;
2259 }
2260 EXPORT_SYMBOL_GPL(ntb_transport_rx_enqueue);
2261
2262 /**
2263  * ntb_transport_tx_enqueue - Enqueue a new NTB queue entry
2264  * @qp: NTB transport layer queue the entry is to be enqueued on
2265  * @cb: per buffer pointer for callback function to use
2266  * @data: pointer to data buffer that will be sent
2267  * @len: length of the data buffer
2268  *
2269  * Enqueue a new transmit buffer onto the transport queue from which a NTB
2270  * payload will be transmitted.  This assumes that a lock is being held to
2271  * serialize access to the qp.
2272  *
2273  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
2274  */
2275 int ntb_transport_tx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
2276                              unsigned int len)
2277 {
2278         struct ntb_queue_entry *entry;
2279         int rc;
2280
2281         if (!qp || !qp->link_is_up || !len)
2282                 return -EINVAL;
2283
2284         entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
2285         if (!entry) {
2286                 qp->tx_err_no_buf++;
2287                 return -EBUSY;
2288         }
2289
2290         entry->cb_data = cb;
2291         entry->buf = data;
2292         entry->len = len;
2293         entry->flags = 0;
2294         entry->errors = 0;
2295         entry->retries = 0;
2296         entry->tx_index = 0;
2297
2298         rc = ntb_process_tx(qp, entry);
2299         if (rc)
2300                 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
2301                              &qp->tx_free_q);
2302
2303         return rc;
2304 }
2305 EXPORT_SYMBOL_GPL(ntb_transport_tx_enqueue);
2306
2307 /**
2308  * ntb_transport_link_up - Notify NTB transport of client readiness to use queue
2309  * @qp: NTB transport layer queue to be enabled
2310  *
2311  * Notify NTB transport layer of client readiness to use queue
2312  */
2313 void ntb_transport_link_up(struct ntb_transport_qp *qp)
2314 {
2315         if (!qp)
2316                 return;
2317
2318         qp->client_ready = true;
2319
2320         if (qp->transport->link_is_up)
2321                 schedule_delayed_work(&qp->link_work, 0);
2322 }
2323 EXPORT_SYMBOL_GPL(ntb_transport_link_up);
2324
2325 /**
2326  * ntb_transport_link_down - Notify NTB transport to no longer enqueue data
2327  * @qp: NTB transport layer queue to be disabled
2328  *
2329  * Notify NTB transport layer of client's desire to no longer receive data on
2330  * transport queue specified.  It is the client's responsibility to ensure all
2331  * entries on queue are purged or otherwise handled appropriately.
2332  */
2333 void ntb_transport_link_down(struct ntb_transport_qp *qp)
2334 {
2335         int val;
2336
2337         if (!qp)
2338                 return;
2339
2340         qp->client_ready = false;
2341
2342         val = ntb_spad_read(qp->ndev, QP_LINKS);
2343
2344         ntb_peer_spad_write(qp->ndev, PIDX, QP_LINKS, val & ~BIT(qp->qp_num));
2345
2346         if (qp->link_is_up)
2347                 ntb_send_link_down(qp);
2348         else
2349                 cancel_delayed_work_sync(&qp->link_work);
2350 }
2351 EXPORT_SYMBOL_GPL(ntb_transport_link_down);
2352
2353 /**
2354  * ntb_transport_link_query - Query transport link state
2355  * @qp: NTB transport layer queue to be queried
2356  *
2357  * Query connectivity to the remote system of the NTB transport queue
2358  *
2359  * RETURNS: true for link up or false for link down
2360  */
2361 bool ntb_transport_link_query(struct ntb_transport_qp *qp)
2362 {
2363         if (!qp)
2364                 return false;
2365
2366         return qp->link_is_up;
2367 }
2368 EXPORT_SYMBOL_GPL(ntb_transport_link_query);
2369
2370 /**
2371  * ntb_transport_qp_num - Query the qp number
2372  * @qp: NTB transport layer queue to be queried
2373  *
2374  * Query qp number of the NTB transport queue
2375  *
2376  * RETURNS: a zero based number specifying the qp number
2377  */
2378 unsigned char ntb_transport_qp_num(struct ntb_transport_qp *qp)
2379 {
2380         if (!qp)
2381                 return 0;
2382
2383         return qp->qp_num;
2384 }
2385 EXPORT_SYMBOL_GPL(ntb_transport_qp_num);
2386
2387 /**
2388  * ntb_transport_max_size - Query the max payload size of a qp
2389  * @qp: NTB transport layer queue to be queried
2390  *
2391  * Query the maximum payload size permissible on the given qp
2392  *
2393  * RETURNS: the max payload size of a qp
2394  */
2395 unsigned int ntb_transport_max_size(struct ntb_transport_qp *qp)
2396 {
2397         unsigned int max_size;
2398         unsigned int copy_align;
2399         struct dma_chan *rx_chan, *tx_chan;
2400
2401         if (!qp)
2402                 return 0;
2403
2404         rx_chan = qp->rx_dma_chan;
2405         tx_chan = qp->tx_dma_chan;
2406
2407         copy_align = max(rx_chan ? rx_chan->device->copy_align : 0,
2408                          tx_chan ? tx_chan->device->copy_align : 0);
2409
2410         /* If DMA engine usage is possible, try to find the max size for that */
2411         max_size = qp->tx_max_frame - sizeof(struct ntb_payload_header);
2412         max_size = round_down(max_size, 1 << copy_align);
2413
2414         return max_size;
2415 }
2416 EXPORT_SYMBOL_GPL(ntb_transport_max_size);
2417
2418 unsigned int ntb_transport_tx_free_entry(struct ntb_transport_qp *qp)
2419 {
2420         unsigned int head = qp->tx_index;
2421         unsigned int tail = qp->remote_rx_info->entry;
2422
2423         return tail > head ? tail - head : qp->tx_max_entry + tail - head;
2424 }
2425 EXPORT_SYMBOL_GPL(ntb_transport_tx_free_entry);
2426
2427 static void ntb_transport_doorbell_callback(void *data, int vector)
2428 {
2429         struct ntb_transport_ctx *nt = data;
2430         struct ntb_transport_qp *qp;
2431         u64 db_bits;
2432         unsigned int qp_num;
2433
2434         if (ntb_db_read(nt->ndev) & nt->msi_db_mask) {
2435                 ntb_transport_msi_peer_desc_changed(nt);
2436                 ntb_db_clear(nt->ndev, nt->msi_db_mask);
2437         }
2438
2439         db_bits = (nt->qp_bitmap & ~nt->qp_bitmap_free &
2440                    ntb_db_vector_mask(nt->ndev, vector));
2441
2442         while (db_bits) {
2443                 qp_num = __ffs(db_bits);
2444                 qp = &nt->qp_vec[qp_num];
2445
2446                 if (qp->active)
2447                         tasklet_schedule(&qp->rxc_db_work);
2448
2449                 db_bits &= ~BIT_ULL(qp_num);
2450         }
2451 }
2452
2453 static const struct ntb_ctx_ops ntb_transport_ops = {
2454         .link_event = ntb_transport_event_callback,
2455         .db_event = ntb_transport_doorbell_callback,
2456 };
2457
2458 static struct ntb_client ntb_transport_client = {
2459         .ops = {
2460                 .probe = ntb_transport_probe,
2461                 .remove = ntb_transport_free,
2462         },
2463 };
2464
2465 static int __init ntb_transport_init(void)
2466 {
2467         int rc;
2468
2469         pr_info("%s, version %s\n", NTB_TRANSPORT_DESC, NTB_TRANSPORT_VER);
2470
2471         if (debugfs_initialized())
2472                 nt_debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
2473
2474         rc = bus_register(&ntb_transport_bus);
2475         if (rc)
2476                 goto err_bus;
2477
2478         rc = ntb_register_client(&ntb_transport_client);
2479         if (rc)
2480                 goto err_client;
2481
2482         return 0;
2483
2484 err_client:
2485         bus_unregister(&ntb_transport_bus);
2486 err_bus:
2487         debugfs_remove_recursive(nt_debugfs_dir);
2488         return rc;
2489 }
2490 module_init(ntb_transport_init);
2491
2492 static void __exit ntb_transport_exit(void)
2493 {
2494         ntb_unregister_client(&ntb_transport_client);
2495         bus_unregister(&ntb_transport_bus);
2496         debugfs_remove_recursive(nt_debugfs_dir);
2497 }
2498 module_exit(ntb_transport_exit);