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/ntb.h" 62 #include "linux/ntb_transport.h" 63 64 #define NTB_TRANSPORT_VERSION 4 65 #define NTB_TRANSPORT_VER "4" 66 #define NTB_TRANSPORT_NAME "ntb_transport" 67 #define NTB_TRANSPORT_DESC "Software Queue-Pair Transport over NTB" 68 69 MODULE_DESCRIPTION(NTB_TRANSPORT_DESC); 70 MODULE_VERSION(NTB_TRANSPORT_VER); 71 MODULE_LICENSE("Dual BSD/GPL"); 72 MODULE_AUTHOR("Intel Corporation"); 73 74 static unsigned long max_mw_size; 75 module_param(max_mw_size, ulong, 0644); 76 MODULE_PARM_DESC(max_mw_size, "Limit size of large memory windows"); 77 78 static unsigned int transport_mtu = 0x401E; 79 module_param(transport_mtu, uint, 0644); 80 MODULE_PARM_DESC(transport_mtu, "Maximum size of NTB transport packets"); 81 82 static unsigned char max_num_clients; 83 module_param(max_num_clients, byte, 0644); 84 MODULE_PARM_DESC(max_num_clients, "Maximum number of NTB transport clients"); 85 86 static unsigned int copy_bytes = 1024; 87 module_param(copy_bytes, uint, 0644); 88 MODULE_PARM_DESC(copy_bytes, "Threshold under which NTB will use the CPU to copy instead of DMA"); 89 90 static struct dentry *nt_debugfs_dir; 91 92 struct ntb_queue_entry { 93 /* ntb_queue list reference */ 94 struct list_head entry; 95 /* pointers to data to be transferred */ 96 void *cb_data; 97 void *buf; 98 unsigned int len; 99 unsigned int flags; 100 101 struct ntb_transport_qp *qp; 102 union { 103 struct ntb_payload_header __iomem *tx_hdr; 104 struct ntb_payload_header *rx_hdr; 105 }; 106 unsigned int index; 107 }; 108 109 struct ntb_rx_info { 110 unsigned int entry; 111 }; 112 113 struct ntb_transport_qp { 114 struct ntb_transport_ctx *transport; 115 struct ntb_dev *ndev; 116 void *cb_data; 117 struct dma_chan *dma_chan; 118 119 bool client_ready; 120 bool link_is_up; 121 122 u8 qp_num; /* Only 64 QP's are allowed. 0-63 */ 123 u64 qp_bit; 124 125 struct ntb_rx_info __iomem *rx_info; 126 struct ntb_rx_info *remote_rx_info; 127 128 void (*tx_handler)(struct ntb_transport_qp *qp, void *qp_data, 129 void *data, int len); 130 struct list_head tx_free_q; 131 spinlock_t ntb_tx_free_q_lock; 132 void __iomem *tx_mw; 133 dma_addr_t tx_mw_phys; 134 unsigned int tx_index; 135 unsigned int tx_max_entry; 136 unsigned int tx_max_frame; 137 138 void (*rx_handler)(struct ntb_transport_qp *qp, void *qp_data, 139 void *data, int len); 140 struct list_head rx_pend_q; 141 struct list_head rx_free_q; 142 spinlock_t ntb_rx_pend_q_lock; 143 spinlock_t ntb_rx_free_q_lock; 144 void *rx_buff; 145 unsigned int rx_index; 146 unsigned int rx_max_entry; 147 unsigned int rx_max_frame; 148 dma_cookie_t last_cookie; 149 struct tasklet_struct rxc_db_work; 150 151 void (*event_handler)(void *data, int status); 152 struct delayed_work link_work; 153 struct work_struct link_cleanup; 154 155 struct dentry *debugfs_dir; 156 struct dentry *debugfs_stats; 157 158 /* Stats */ 159 u64 rx_bytes; 160 u64 rx_pkts; 161 u64 rx_ring_empty; 162 u64 rx_err_no_buf; 163 u64 rx_err_oflow; 164 u64 rx_err_ver; 165 u64 rx_memcpy; 166 u64 rx_async; 167 u64 tx_bytes; 168 u64 tx_pkts; 169 u64 tx_ring_full; 170 u64 tx_err_no_buf; 171 u64 tx_memcpy; 172 u64 tx_async; 173 }; 174 175 struct ntb_transport_mw { 176 phys_addr_t phys_addr; 177 resource_size_t phys_size; 178 resource_size_t xlat_align; 179 resource_size_t xlat_align_size; 180 void __iomem *vbase; 181 size_t xlat_size; 182 size_t buff_size; 183 void *virt_addr; 184 dma_addr_t dma_addr; 185 }; 186 187 struct ntb_transport_client_dev { 188 struct list_head entry; 189 struct ntb_transport_ctx *nt; 190 struct device dev; 191 }; 192 193 struct ntb_transport_ctx { 194 struct list_head entry; 195 struct list_head client_devs; 196 197 struct ntb_dev *ndev; 198 199 struct ntb_transport_mw *mw_vec; 200 struct ntb_transport_qp *qp_vec; 201 unsigned int mw_count; 202 unsigned int qp_count; 203 u64 qp_bitmap; 204 u64 qp_bitmap_free; 205 206 bool link_is_up; 207 struct delayed_work link_work; 208 struct work_struct link_cleanup; 209 }; 210 211 enum { 212 DESC_DONE_FLAG = BIT(0), 213 LINK_DOWN_FLAG = BIT(1), 214 }; 215 216 struct ntb_payload_header { 217 unsigned int ver; 218 unsigned int len; 219 unsigned int flags; 220 }; 221 222 enum { 223 VERSION = 0, 224 QP_LINKS, 225 NUM_QPS, 226 NUM_MWS, 227 MW0_SZ_HIGH, 228 MW0_SZ_LOW, 229 MW1_SZ_HIGH, 230 MW1_SZ_LOW, 231 MAX_SPAD, 232 }; 233 234 #define dev_client_dev(__dev) \ 235 container_of((__dev), struct ntb_transport_client_dev, dev) 236 237 #define drv_client(__drv) \ 238 container_of((__drv), struct ntb_transport_client, driver) 239 240 #define QP_TO_MW(nt, qp) ((qp) % nt->mw_count) 241 #define NTB_QP_DEF_NUM_ENTRIES 100 242 #define NTB_LINK_DOWN_TIMEOUT 10 243 244 static void ntb_transport_rxc_db(unsigned long data); 245 static const struct ntb_ctx_ops ntb_transport_ops; 246 static struct ntb_client ntb_transport_client; 247 248 static int ntb_transport_bus_match(struct device *dev, 249 struct device_driver *drv) 250 { 251 return !strncmp(dev_name(dev), drv->name, strlen(drv->name)); 252 } 253 254 static int ntb_transport_bus_probe(struct device *dev) 255 { 256 const struct ntb_transport_client *client; 257 int rc = -EINVAL; 258 259 get_device(dev); 260 261 client = drv_client(dev->driver); 262 rc = client->probe(dev); 263 if (rc) 264 put_device(dev); 265 266 return rc; 267 } 268 269 static int ntb_transport_bus_remove(struct device *dev) 270 { 271 const struct ntb_transport_client *client; 272 273 client = drv_client(dev->driver); 274 client->remove(dev); 275 276 put_device(dev); 277 278 return 0; 279 } 280 281 static struct bus_type ntb_transport_bus = { 282 .name = "ntb_transport", 283 .match = ntb_transport_bus_match, 284 .probe = ntb_transport_bus_probe, 285 .remove = ntb_transport_bus_remove, 286 }; 287 288 static LIST_HEAD(ntb_transport_list); 289 290 static int ntb_bus_init(struct ntb_transport_ctx *nt) 291 { 292 list_add(&nt->entry, &ntb_transport_list); 293 return 0; 294 } 295 296 static void ntb_bus_remove(struct ntb_transport_ctx *nt) 297 { 298 struct ntb_transport_client_dev *client_dev, *cd; 299 300 list_for_each_entry_safe(client_dev, cd, &nt->client_devs, entry) { 301 dev_err(client_dev->dev.parent, "%s still attached to bus, removing\n", 302 dev_name(&client_dev->dev)); 303 list_del(&client_dev->entry); 304 device_unregister(&client_dev->dev); 305 } 306 307 list_del(&nt->entry); 308 } 309 310 static void ntb_transport_client_release(struct device *dev) 311 { 312 struct ntb_transport_client_dev *client_dev; 313 314 client_dev = dev_client_dev(dev); 315 kfree(client_dev); 316 } 317 318 /** 319 * ntb_transport_unregister_client_dev - Unregister NTB client device 320 * @device_name: Name of NTB client device 321 * 322 * Unregister an NTB client device with the NTB transport layer 323 */ 324 void ntb_transport_unregister_client_dev(char *device_name) 325 { 326 struct ntb_transport_client_dev *client, *cd; 327 struct ntb_transport_ctx *nt; 328 329 list_for_each_entry(nt, &ntb_transport_list, entry) 330 list_for_each_entry_safe(client, cd, &nt->client_devs, entry) 331 if (!strncmp(dev_name(&client->dev), device_name, 332 strlen(device_name))) { 333 list_del(&client->entry); 334 device_unregister(&client->dev); 335 } 336 } 337 EXPORT_SYMBOL_GPL(ntb_transport_unregister_client_dev); 338 339 /** 340 * ntb_transport_register_client_dev - Register NTB client device 341 * @device_name: Name of NTB client device 342 * 343 * Register an NTB client device with the NTB transport layer 344 */ 345 int ntb_transport_register_client_dev(char *device_name) 346 { 347 struct ntb_transport_client_dev *client_dev; 348 struct ntb_transport_ctx *nt; 349 int rc, i = 0; 350 351 if (list_empty(&ntb_transport_list)) 352 return -ENODEV; 353 354 list_for_each_entry(nt, &ntb_transport_list, entry) { 355 struct device *dev; 356 357 client_dev = kzalloc(sizeof(*client_dev), 358 GFP_KERNEL); 359 if (!client_dev) { 360 rc = -ENOMEM; 361 goto err; 362 } 363 364 dev = &client_dev->dev; 365 366 /* setup and register client devices */ 367 dev_set_name(dev, "%s%d", device_name, i); 368 dev->bus = &ntb_transport_bus; 369 dev->release = ntb_transport_client_release; 370 dev->parent = &nt->ndev->dev; 371 372 rc = device_register(dev); 373 if (rc) { 374 kfree(client_dev); 375 goto err; 376 } 377 378 list_add_tail(&client_dev->entry, &nt->client_devs); 379 i++; 380 } 381 382 return 0; 383 384 err: 385 ntb_transport_unregister_client_dev(device_name); 386 387 return rc; 388 } 389 EXPORT_SYMBOL_GPL(ntb_transport_register_client_dev); 390 391 /** 392 * ntb_transport_register_client - Register NTB client driver 393 * @drv: NTB client driver to be registered 394 * 395 * Register an NTB client driver with the NTB transport layer 396 * 397 * RETURNS: An appropriate -ERRNO error value on error, or zero for success. 398 */ 399 int ntb_transport_register_client(struct ntb_transport_client *drv) 400 { 401 drv->driver.bus = &ntb_transport_bus; 402 403 if (list_empty(&ntb_transport_list)) 404 return -ENODEV; 405 406 return driver_register(&drv->driver); 407 } 408 EXPORT_SYMBOL_GPL(ntb_transport_register_client); 409 410 /** 411 * ntb_transport_unregister_client - Unregister NTB client driver 412 * @drv: NTB client driver to be unregistered 413 * 414 * Unregister an NTB client driver with the NTB transport layer 415 * 416 * RETURNS: An appropriate -ERRNO error value on error, or zero for success. 417 */ 418 void ntb_transport_unregister_client(struct ntb_transport_client *drv) 419 { 420 driver_unregister(&drv->driver); 421 } 422 EXPORT_SYMBOL_GPL(ntb_transport_unregister_client); 423 424 static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count, 425 loff_t *offp) 426 { 427 struct ntb_transport_qp *qp; 428 char *buf; 429 ssize_t ret, out_offset, out_count; 430 431 out_count = 1000; 432 433 buf = kmalloc(out_count, GFP_KERNEL); 434 if (!buf) 435 return -ENOMEM; 436 437 qp = filp->private_data; 438 out_offset = 0; 439 out_offset += snprintf(buf + out_offset, out_count - out_offset, 440 "NTB QP stats\n"); 441 out_offset += snprintf(buf + out_offset, out_count - out_offset, 442 "rx_bytes - \t%llu\n", qp->rx_bytes); 443 out_offset += snprintf(buf + out_offset, out_count - out_offset, 444 "rx_pkts - \t%llu\n", qp->rx_pkts); 445 out_offset += snprintf(buf + out_offset, out_count - out_offset, 446 "rx_memcpy - \t%llu\n", qp->rx_memcpy); 447 out_offset += snprintf(buf + out_offset, out_count - out_offset, 448 "rx_async - \t%llu\n", qp->rx_async); 449 out_offset += snprintf(buf + out_offset, out_count - out_offset, 450 "rx_ring_empty - %llu\n", qp->rx_ring_empty); 451 out_offset += snprintf(buf + out_offset, out_count - out_offset, 452 "rx_err_no_buf - %llu\n", qp->rx_err_no_buf); 453 out_offset += snprintf(buf + out_offset, out_count - out_offset, 454 "rx_err_oflow - \t%llu\n", qp->rx_err_oflow); 455 out_offset += snprintf(buf + out_offset, out_count - out_offset, 456 "rx_err_ver - \t%llu\n", qp->rx_err_ver); 457 out_offset += snprintf(buf + out_offset, out_count - out_offset, 458 "rx_buff - \t%p\n", qp->rx_buff); 459 out_offset += snprintf(buf + out_offset, out_count - out_offset, 460 "rx_index - \t%u\n", qp->rx_index); 461 out_offset += snprintf(buf + out_offset, out_count - out_offset, 462 "rx_max_entry - \t%u\n", qp->rx_max_entry); 463 464 out_offset += snprintf(buf + out_offset, out_count - out_offset, 465 "tx_bytes - \t%llu\n", qp->tx_bytes); 466 out_offset += snprintf(buf + out_offset, out_count - out_offset, 467 "tx_pkts - \t%llu\n", qp->tx_pkts); 468 out_offset += snprintf(buf + out_offset, out_count - out_offset, 469 "tx_memcpy - \t%llu\n", qp->tx_memcpy); 470 out_offset += snprintf(buf + out_offset, out_count - out_offset, 471 "tx_async - \t%llu\n", qp->tx_async); 472 out_offset += snprintf(buf + out_offset, out_count - out_offset, 473 "tx_ring_full - \t%llu\n", qp->tx_ring_full); 474 out_offset += snprintf(buf + out_offset, out_count - out_offset, 475 "tx_err_no_buf - %llu\n", qp->tx_err_no_buf); 476 out_offset += snprintf(buf + out_offset, out_count - out_offset, 477 "tx_mw - \t%p\n", qp->tx_mw); 478 out_offset += snprintf(buf + out_offset, out_count - out_offset, 479 "tx_index - \t%u\n", qp->tx_index); 480 out_offset += snprintf(buf + out_offset, out_count - out_offset, 481 "tx_max_entry - \t%u\n", qp->tx_max_entry); 482 483 out_offset += snprintf(buf + out_offset, out_count - out_offset, 484 "\nQP Link %s\n", 485 qp->link_is_up ? "Up" : "Down"); 486 if (out_offset > out_count) 487 out_offset = out_count; 488 489 ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset); 490 kfree(buf); 491 return ret; 492 } 493 494 static const struct file_operations ntb_qp_debugfs_stats = { 495 .owner = THIS_MODULE, 496 .open = simple_open, 497 .read = debugfs_read, 498 }; 499 500 static void ntb_list_add(spinlock_t *lock, struct list_head *entry, 501 struct list_head *list) 502 { 503 unsigned long flags; 504 505 spin_lock_irqsave(lock, flags); 506 list_add_tail(entry, list); 507 spin_unlock_irqrestore(lock, flags); 508 } 509 510 static struct ntb_queue_entry *ntb_list_rm(spinlock_t *lock, 511 struct list_head *list) 512 { 513 struct ntb_queue_entry *entry; 514 unsigned long flags; 515 516 spin_lock_irqsave(lock, flags); 517 if (list_empty(list)) { 518 entry = NULL; 519 goto out; 520 } 521 entry = list_first_entry(list, struct ntb_queue_entry, entry); 522 list_del(&entry->entry); 523 out: 524 spin_unlock_irqrestore(lock, flags); 525 526 return entry; 527 } 528 529 static int ntb_transport_setup_qp_mw(struct ntb_transport_ctx *nt, 530 unsigned int qp_num) 531 { 532 struct ntb_transport_qp *qp = &nt->qp_vec[qp_num]; 533 struct ntb_transport_mw *mw; 534 unsigned int rx_size, num_qps_mw; 535 unsigned int mw_num, mw_count, qp_count; 536 unsigned int i; 537 538 mw_count = nt->mw_count; 539 qp_count = nt->qp_count; 540 541 mw_num = QP_TO_MW(nt, qp_num); 542 mw = &nt->mw_vec[mw_num]; 543 544 if (!mw->virt_addr) 545 return -ENOMEM; 546 547 if (qp_count % mw_count && mw_num + 1 < qp_count / mw_count) 548 num_qps_mw = qp_count / mw_count + 1; 549 else 550 num_qps_mw = qp_count / mw_count; 551 552 rx_size = (unsigned int)mw->xlat_size / num_qps_mw; 553 qp->rx_buff = mw->virt_addr + rx_size * qp_num / mw_count; 554 rx_size -= sizeof(struct ntb_rx_info); 555 556 qp->remote_rx_info = qp->rx_buff + rx_size; 557 558 /* Due to housekeeping, there must be atleast 2 buffs */ 559 qp->rx_max_frame = min(transport_mtu, rx_size / 2); 560 qp->rx_max_entry = rx_size / qp->rx_max_frame; 561 qp->rx_index = 0; 562 563 qp->remote_rx_info->entry = qp->rx_max_entry - 1; 564 565 /* setup the hdr offsets with 0's */ 566 for (i = 0; i < qp->rx_max_entry; i++) { 567 void *offset = (qp->rx_buff + qp->rx_max_frame * (i + 1) - 568 sizeof(struct ntb_payload_header)); 569 memset(offset, 0, sizeof(struct ntb_payload_header)); 570 } 571 572 qp->rx_pkts = 0; 573 qp->tx_pkts = 0; 574 qp->tx_index = 0; 575 576 return 0; 577 } 578 579 static void ntb_free_mw(struct ntb_transport_ctx *nt, int num_mw) 580 { 581 struct ntb_transport_mw *mw = &nt->mw_vec[num_mw]; 582 struct pci_dev *pdev = nt->ndev->pdev; 583 584 if (!mw->virt_addr) 585 return; 586 587 ntb_mw_clear_trans(nt->ndev, num_mw); 588 dma_free_coherent(&pdev->dev, mw->buff_size, 589 mw->virt_addr, mw->dma_addr); 590 mw->xlat_size = 0; 591 mw->buff_size = 0; 592 mw->virt_addr = NULL; 593 } 594 595 static int ntb_set_mw(struct ntb_transport_ctx *nt, int num_mw, 596 unsigned int size) 597 { 598 struct ntb_transport_mw *mw = &nt->mw_vec[num_mw]; 599 struct pci_dev *pdev = nt->ndev->pdev; 600 unsigned int xlat_size, buff_size; 601 int rc; 602 603 xlat_size = round_up(size, mw->xlat_align_size); 604 buff_size = round_up(size, mw->xlat_align); 605 606 /* No need to re-setup */ 607 if (mw->xlat_size == xlat_size) 608 return 0; 609 610 if (mw->buff_size) 611 ntb_free_mw(nt, num_mw); 612 613 /* Alloc memory for receiving data. Must be aligned */ 614 mw->xlat_size = xlat_size; 615 mw->buff_size = buff_size; 616 617 mw->virt_addr = dma_alloc_coherent(&pdev->dev, buff_size, 618 &mw->dma_addr, GFP_KERNEL); 619 if (!mw->virt_addr) { 620 mw->xlat_size = 0; 621 mw->buff_size = 0; 622 dev_err(&pdev->dev, "Unable to alloc MW buff of size %d\n", 623 buff_size); 624 return -ENOMEM; 625 } 626 627 /* 628 * we must ensure that the memory address allocated is BAR size 629 * aligned in order for the XLAT register to take the value. This 630 * is a requirement of the hardware. It is recommended to setup CMA 631 * for BAR sizes equal or greater than 4MB. 632 */ 633 if (!IS_ALIGNED(mw->dma_addr, mw->xlat_align)) { 634 dev_err(&pdev->dev, "DMA memory %pad is not aligned\n", 635 &mw->dma_addr); 636 ntb_free_mw(nt, num_mw); 637 return -ENOMEM; 638 } 639 640 /* Notify HW the memory location of the receive buffer */ 641 rc = ntb_mw_set_trans(nt->ndev, num_mw, mw->dma_addr, mw->xlat_size); 642 if (rc) { 643 dev_err(&pdev->dev, "Unable to set mw%d translation", num_mw); 644 ntb_free_mw(nt, num_mw); 645 return -EIO; 646 } 647 648 return 0; 649 } 650 651 static void ntb_qp_link_cleanup(struct ntb_transport_qp *qp) 652 { 653 struct ntb_transport_ctx *nt = qp->transport; 654 struct pci_dev *pdev = nt->ndev->pdev; 655 656 if (qp->link_is_up) { 657 cancel_delayed_work_sync(&qp->link_work); 658 return; 659 } 660 661 dev_info(&pdev->dev, "qp %d: Link Down\n", qp->qp_num); 662 qp->link_is_up = false; 663 664 if (qp->event_handler) 665 qp->event_handler(qp->cb_data, qp->link_is_up); 666 } 667 668 static void ntb_qp_link_cleanup_work(struct work_struct *work) 669 { 670 struct ntb_transport_qp *qp = container_of(work, 671 struct ntb_transport_qp, 672 link_cleanup); 673 struct ntb_transport_ctx *nt = qp->transport; 674 675 ntb_qp_link_cleanup(qp); 676 677 if (nt->link_is_up) 678 schedule_delayed_work(&qp->link_work, 679 msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT)); 680 } 681 682 static void ntb_qp_link_down(struct ntb_transport_qp *qp) 683 { 684 schedule_work(&qp->link_cleanup); 685 } 686 687 static void ntb_transport_link_cleanup(struct ntb_transport_ctx *nt) 688 { 689 struct ntb_transport_qp *qp; 690 u64 qp_bitmap_alloc; 691 int i; 692 693 qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free; 694 695 /* Pass along the info to any clients */ 696 for (i = 0; i < nt->qp_count; i++) 697 if (qp_bitmap_alloc & BIT_ULL(i)) { 698 qp = &nt->qp_vec[i]; 699 ntb_qp_link_cleanup(qp); 700 cancel_work_sync(&qp->link_cleanup); 701 cancel_delayed_work_sync(&qp->link_work); 702 } 703 704 if (!nt->link_is_up) 705 cancel_delayed_work_sync(&nt->link_work); 706 707 /* The scratchpad registers keep the values if the remote side 708 * goes down, blast them now to give them a sane value the next 709 * time they are accessed 710 */ 711 for (i = 0; i < MAX_SPAD; i++) 712 ntb_spad_write(nt->ndev, i, 0); 713 } 714 715 static void ntb_transport_link_cleanup_work(struct work_struct *work) 716 { 717 struct ntb_transport_ctx *nt = 718 container_of(work, struct ntb_transport_ctx, link_cleanup); 719 720 ntb_transport_link_cleanup(nt); 721 } 722 723 static void ntb_transport_event_callback(void *data) 724 { 725 struct ntb_transport_ctx *nt = data; 726 727 if (ntb_link_is_up(nt->ndev, NULL, NULL) == 1) 728 schedule_delayed_work(&nt->link_work, 0); 729 else 730 schedule_work(&nt->link_cleanup); 731 } 732 733 static void ntb_transport_link_work(struct work_struct *work) 734 { 735 struct ntb_transport_ctx *nt = 736 container_of(work, struct ntb_transport_ctx, link_work.work); 737 struct ntb_dev *ndev = nt->ndev; 738 struct pci_dev *pdev = ndev->pdev; 739 resource_size_t size; 740 u32 val; 741 int rc, i, spad; 742 743 /* send the local info, in the opposite order of the way we read it */ 744 for (i = 0; i < nt->mw_count; i++) { 745 size = nt->mw_vec[i].phys_size; 746 747 if (max_mw_size && size > max_mw_size) 748 size = max_mw_size; 749 750 spad = MW0_SZ_HIGH + (i * 2); 751 ntb_peer_spad_write(ndev, spad, (u32)(size >> 32)); 752 753 spad = MW0_SZ_LOW + (i * 2); 754 ntb_peer_spad_write(ndev, spad, (u32)size); 755 } 756 757 ntb_peer_spad_write(ndev, NUM_MWS, nt->mw_count); 758 759 ntb_peer_spad_write(ndev, NUM_QPS, nt->qp_count); 760 761 ntb_peer_spad_write(ndev, VERSION, NTB_TRANSPORT_VERSION); 762 763 /* Query the remote side for its info */ 764 val = ntb_spad_read(ndev, VERSION); 765 dev_dbg(&pdev->dev, "Remote version = %d\n", val); 766 if (val != NTB_TRANSPORT_VERSION) 767 goto out; 768 769 val = ntb_spad_read(ndev, NUM_QPS); 770 dev_dbg(&pdev->dev, "Remote max number of qps = %d\n", val); 771 if (val != nt->qp_count) 772 goto out; 773 774 val = ntb_spad_read(ndev, NUM_MWS); 775 dev_dbg(&pdev->dev, "Remote number of mws = %d\n", val); 776 if (val != nt->mw_count) 777 goto out; 778 779 for (i = 0; i < nt->mw_count; i++) { 780 u64 val64; 781 782 val = ntb_spad_read(ndev, MW0_SZ_HIGH + (i * 2)); 783 val64 = (u64)val << 32; 784 785 val = ntb_spad_read(ndev, MW0_SZ_LOW + (i * 2)); 786 val64 |= val; 787 788 dev_dbg(&pdev->dev, "Remote MW%d size = %#llx\n", i, val64); 789 790 rc = ntb_set_mw(nt, i, val64); 791 if (rc) 792 goto out1; 793 } 794 795 nt->link_is_up = true; 796 797 for (i = 0; i < nt->qp_count; i++) { 798 struct ntb_transport_qp *qp = &nt->qp_vec[i]; 799 800 ntb_transport_setup_qp_mw(nt, i); 801 802 if (qp->client_ready) 803 schedule_delayed_work(&qp->link_work, 0); 804 } 805 806 return; 807 808 out1: 809 for (i = 0; i < nt->mw_count; i++) 810 ntb_free_mw(nt, i); 811 out: 812 if (ntb_link_is_up(ndev, NULL, NULL) == 1) 813 schedule_delayed_work(&nt->link_work, 814 msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT)); 815 } 816 817 static void ntb_qp_link_work(struct work_struct *work) 818 { 819 struct ntb_transport_qp *qp = container_of(work, 820 struct ntb_transport_qp, 821 link_work.work); 822 struct pci_dev *pdev = qp->ndev->pdev; 823 struct ntb_transport_ctx *nt = qp->transport; 824 int val; 825 826 WARN_ON(!nt->link_is_up); 827 828 val = ntb_spad_read(nt->ndev, QP_LINKS); 829 830 ntb_peer_spad_write(nt->ndev, QP_LINKS, val | BIT(qp->qp_num)); 831 832 /* query remote spad for qp ready bits */ 833 ntb_peer_spad_read(nt->ndev, QP_LINKS); 834 dev_dbg(&pdev->dev, "Remote QP link status = %x\n", val); 835 836 /* See if the remote side is up */ 837 if (val & BIT(qp->qp_num)) { 838 dev_info(&pdev->dev, "qp %d: Link Up\n", qp->qp_num); 839 qp->link_is_up = true; 840 841 if (qp->event_handler) 842 qp->event_handler(qp->cb_data, qp->link_is_up); 843 } else if (nt->link_is_up) 844 schedule_delayed_work(&qp->link_work, 845 msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT)); 846 } 847 848 static int ntb_transport_init_queue(struct ntb_transport_ctx *nt, 849 unsigned int qp_num) 850 { 851 struct ntb_transport_qp *qp; 852 struct ntb_transport_mw *mw; 853 phys_addr_t mw_base; 854 resource_size_t mw_size; 855 unsigned int num_qps_mw, tx_size; 856 unsigned int mw_num, mw_count, qp_count; 857 u64 qp_offset; 858 859 mw_count = nt->mw_count; 860 qp_count = nt->qp_count; 861 862 mw_num = QP_TO_MW(nt, qp_num); 863 mw = &nt->mw_vec[mw_num]; 864 865 qp = &nt->qp_vec[qp_num]; 866 qp->qp_num = qp_num; 867 qp->transport = nt; 868 qp->ndev = nt->ndev; 869 qp->link_is_up = false; 870 qp->client_ready = false; 871 qp->event_handler = NULL; 872 873 if (qp_count % mw_count && mw_num + 1 < qp_count / mw_count) 874 num_qps_mw = qp_count / mw_count + 1; 875 else 876 num_qps_mw = qp_count / mw_count; 877 878 mw_base = nt->mw_vec[mw_num].phys_addr; 879 mw_size = nt->mw_vec[mw_num].phys_size; 880 881 tx_size = (unsigned int)mw_size / num_qps_mw; 882 qp_offset = tx_size * qp_num / mw_count; 883 884 qp->tx_mw = nt->mw_vec[mw_num].vbase + qp_offset; 885 if (!qp->tx_mw) 886 return -EINVAL; 887 888 qp->tx_mw_phys = mw_base + qp_offset; 889 if (!qp->tx_mw_phys) 890 return -EINVAL; 891 892 tx_size -= sizeof(struct ntb_rx_info); 893 qp->rx_info = qp->tx_mw + tx_size; 894 895 /* Due to housekeeping, there must be atleast 2 buffs */ 896 qp->tx_max_frame = min(transport_mtu, tx_size / 2); 897 qp->tx_max_entry = tx_size / qp->tx_max_frame; 898 899 if (nt_debugfs_dir) { 900 char debugfs_name[4]; 901 902 snprintf(debugfs_name, 4, "qp%d", qp_num); 903 qp->debugfs_dir = debugfs_create_dir(debugfs_name, 904 nt_debugfs_dir); 905 906 qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR, 907 qp->debugfs_dir, qp, 908 &ntb_qp_debugfs_stats); 909 } else { 910 qp->debugfs_dir = NULL; 911 qp->debugfs_stats = NULL; 912 } 913 914 INIT_DELAYED_WORK(&qp->link_work, ntb_qp_link_work); 915 INIT_WORK(&qp->link_cleanup, ntb_qp_link_cleanup_work); 916 917 spin_lock_init(&qp->ntb_rx_pend_q_lock); 918 spin_lock_init(&qp->ntb_rx_free_q_lock); 919 spin_lock_init(&qp->ntb_tx_free_q_lock); 920 921 INIT_LIST_HEAD(&qp->rx_pend_q); 922 INIT_LIST_HEAD(&qp->rx_free_q); 923 INIT_LIST_HEAD(&qp->tx_free_q); 924 925 tasklet_init(&qp->rxc_db_work, ntb_transport_rxc_db, 926 (unsigned long)qp); 927 928 return 0; 929 } 930 931 static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev) 932 { 933 struct ntb_transport_ctx *nt; 934 struct ntb_transport_mw *mw; 935 unsigned int mw_count, qp_count; 936 u64 qp_bitmap; 937 int rc, i; 938 939 if (ntb_db_is_unsafe(ndev)) 940 dev_dbg(&ndev->dev, 941 "doorbell is unsafe, proceed anyway...\n"); 942 if (ntb_spad_is_unsafe(ndev)) 943 dev_dbg(&ndev->dev, 944 "scratchpad is unsafe, proceed anyway...\n"); 945 946 nt = kzalloc(sizeof(*nt), GFP_KERNEL); 947 if (!nt) 948 return -ENOMEM; 949 950 nt->ndev = ndev; 951 952 mw_count = ntb_mw_count(ndev); 953 954 nt->mw_count = mw_count; 955 956 nt->mw_vec = kcalloc(mw_count, sizeof(*nt->mw_vec), GFP_KERNEL); 957 if (!nt->mw_vec) { 958 rc = -ENOMEM; 959 goto err; 960 } 961 962 for (i = 0; i < mw_count; i++) { 963 mw = &nt->mw_vec[i]; 964 965 rc = ntb_mw_get_range(ndev, i, &mw->phys_addr, &mw->phys_size, 966 &mw->xlat_align, &mw->xlat_align_size); 967 if (rc) 968 goto err1; 969 970 mw->vbase = ioremap(mw->phys_addr, mw->phys_size); 971 if (!mw->vbase) { 972 rc = -ENOMEM; 973 goto err1; 974 } 975 976 mw->buff_size = 0; 977 mw->xlat_size = 0; 978 mw->virt_addr = NULL; 979 mw->dma_addr = 0; 980 } 981 982 qp_bitmap = ntb_db_valid_mask(ndev); 983 984 qp_count = ilog2(qp_bitmap); 985 if (max_num_clients && max_num_clients < qp_count) 986 qp_count = max_num_clients; 987 else if (mw_count < qp_count) 988 qp_count = mw_count; 989 990 qp_bitmap &= BIT_ULL(qp_count) - 1; 991 992 nt->qp_count = qp_count; 993 nt->qp_bitmap = qp_bitmap; 994 nt->qp_bitmap_free = qp_bitmap; 995 996 nt->qp_vec = kcalloc(qp_count, sizeof(*nt->qp_vec), GFP_KERNEL); 997 if (!nt->qp_vec) { 998 rc = -ENOMEM; 999 goto err2; 1000 } 1001 1002 for (i = 0; i < qp_count; i++) { 1003 rc = ntb_transport_init_queue(nt, i); 1004 if (rc) 1005 goto err3; 1006 } 1007 1008 INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work); 1009 INIT_WORK(&nt->link_cleanup, ntb_transport_link_cleanup_work); 1010 1011 rc = ntb_set_ctx(ndev, nt, &ntb_transport_ops); 1012 if (rc) 1013 goto err3; 1014 1015 INIT_LIST_HEAD(&nt->client_devs); 1016 rc = ntb_bus_init(nt); 1017 if (rc) 1018 goto err4; 1019 1020 nt->link_is_up = false; 1021 ntb_link_enable(ndev, NTB_SPEED_AUTO, NTB_WIDTH_AUTO); 1022 ntb_link_event(ndev); 1023 1024 return 0; 1025 1026 err4: 1027 ntb_clear_ctx(ndev); 1028 err3: 1029 kfree(nt->qp_vec); 1030 err2: 1031 kfree(nt->mw_vec); 1032 err1: 1033 while (i--) { 1034 mw = &nt->mw_vec[i]; 1035 iounmap(mw->vbase); 1036 } 1037 err: 1038 kfree(nt); 1039 return rc; 1040 } 1041 1042 static void ntb_transport_free(struct ntb_client *self, struct ntb_dev *ndev) 1043 { 1044 struct ntb_transport_ctx *nt = ndev->ctx; 1045 struct ntb_transport_qp *qp; 1046 u64 qp_bitmap_alloc; 1047 int i; 1048 1049 ntb_transport_link_cleanup(nt); 1050 cancel_work_sync(&nt->link_cleanup); 1051 cancel_delayed_work_sync(&nt->link_work); 1052 1053 qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free; 1054 1055 /* verify that all the qp's are freed */ 1056 for (i = 0; i < nt->qp_count; i++) { 1057 qp = &nt->qp_vec[i]; 1058 if (qp_bitmap_alloc & BIT_ULL(i)) 1059 ntb_transport_free_queue(qp); 1060 debugfs_remove_recursive(qp->debugfs_dir); 1061 } 1062 1063 ntb_link_disable(ndev); 1064 ntb_clear_ctx(ndev); 1065 1066 ntb_bus_remove(nt); 1067 1068 for (i = nt->mw_count; i--; ) { 1069 ntb_free_mw(nt, i); 1070 iounmap(nt->mw_vec[i].vbase); 1071 } 1072 1073 kfree(nt->qp_vec); 1074 kfree(nt->mw_vec); 1075 kfree(nt); 1076 } 1077 1078 static void ntb_rx_copy_callback(void *data) 1079 { 1080 struct ntb_queue_entry *entry = data; 1081 struct ntb_transport_qp *qp = entry->qp; 1082 void *cb_data = entry->cb_data; 1083 unsigned int len = entry->len; 1084 struct ntb_payload_header *hdr = entry->rx_hdr; 1085 1086 hdr->flags = 0; 1087 1088 iowrite32(entry->index, &qp->rx_info->entry); 1089 1090 ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry, &qp->rx_free_q); 1091 1092 if (qp->rx_handler && qp->client_ready) 1093 qp->rx_handler(qp, qp->cb_data, cb_data, len); 1094 } 1095 1096 static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void *offset) 1097 { 1098 void *buf = entry->buf; 1099 size_t len = entry->len; 1100 1101 memcpy(buf, offset, len); 1102 1103 /* Ensure that the data is fully copied out before clearing the flag */ 1104 wmb(); 1105 1106 ntb_rx_copy_callback(entry); 1107 } 1108 1109 static void ntb_async_rx(struct ntb_queue_entry *entry, void *offset, 1110 size_t len) 1111 { 1112 struct dma_async_tx_descriptor *txd; 1113 struct ntb_transport_qp *qp = entry->qp; 1114 struct dma_chan *chan = qp->dma_chan; 1115 struct dma_device *device; 1116 size_t pay_off, buff_off; 1117 struct dmaengine_unmap_data *unmap; 1118 dma_cookie_t cookie; 1119 void *buf = entry->buf; 1120 1121 entry->len = len; 1122 1123 if (!chan) 1124 goto err; 1125 1126 if (len < copy_bytes) 1127 goto err_wait; 1128 1129 device = chan->device; 1130 pay_off = (size_t)offset & ~PAGE_MASK; 1131 buff_off = (size_t)buf & ~PAGE_MASK; 1132 1133 if (!is_dma_copy_aligned(device, pay_off, buff_off, len)) 1134 goto err_wait; 1135 1136 unmap = dmaengine_get_unmap_data(device->dev, 2, GFP_NOWAIT); 1137 if (!unmap) 1138 goto err_wait; 1139 1140 unmap->len = len; 1141 unmap->addr[0] = dma_map_page(device->dev, virt_to_page(offset), 1142 pay_off, len, DMA_TO_DEVICE); 1143 if (dma_mapping_error(device->dev, unmap->addr[0])) 1144 goto err_get_unmap; 1145 1146 unmap->to_cnt = 1; 1147 1148 unmap->addr[1] = dma_map_page(device->dev, virt_to_page(buf), 1149 buff_off, len, DMA_FROM_DEVICE); 1150 if (dma_mapping_error(device->dev, unmap->addr[1])) 1151 goto err_get_unmap; 1152 1153 unmap->from_cnt = 1; 1154 1155 txd = device->device_prep_dma_memcpy(chan, unmap->addr[1], 1156 unmap->addr[0], len, 1157 DMA_PREP_INTERRUPT); 1158 if (!txd) 1159 goto err_get_unmap; 1160 1161 txd->callback = ntb_rx_copy_callback; 1162 txd->callback_param = entry; 1163 dma_set_unmap(txd, unmap); 1164 1165 cookie = dmaengine_submit(txd); 1166 if (dma_submit_error(cookie)) 1167 goto err_set_unmap; 1168 1169 dmaengine_unmap_put(unmap); 1170 1171 qp->last_cookie = cookie; 1172 1173 qp->rx_async++; 1174 1175 return; 1176 1177 err_set_unmap: 1178 dmaengine_unmap_put(unmap); 1179 err_get_unmap: 1180 dmaengine_unmap_put(unmap); 1181 err_wait: 1182 /* If the callbacks come out of order, the writing of the index to the 1183 * last completed will be out of order. This may result in the 1184 * receive stalling forever. 1185 */ 1186 dma_sync_wait(chan, qp->last_cookie); 1187 err: 1188 ntb_memcpy_rx(entry, offset); 1189 qp->rx_memcpy++; 1190 } 1191 1192 static int ntb_process_rxc(struct ntb_transport_qp *qp) 1193 { 1194 struct ntb_payload_header *hdr; 1195 struct ntb_queue_entry *entry; 1196 void *offset; 1197 int rc; 1198 1199 offset = qp->rx_buff + qp->rx_max_frame * qp->rx_index; 1200 hdr = offset + qp->rx_max_frame - sizeof(struct ntb_payload_header); 1201 1202 dev_dbg(&qp->ndev->pdev->dev, "qp %d: RX ver %u len %d flags %x\n", 1203 qp->qp_num, hdr->ver, hdr->len, hdr->flags); 1204 1205 if (!(hdr->flags & DESC_DONE_FLAG)) { 1206 dev_dbg(&qp->ndev->pdev->dev, "done flag not set\n"); 1207 qp->rx_ring_empty++; 1208 return -EAGAIN; 1209 } 1210 1211 if (hdr->flags & LINK_DOWN_FLAG) { 1212 dev_dbg(&qp->ndev->pdev->dev, "link down flag set\n"); 1213 ntb_qp_link_down(qp); 1214 hdr->flags = 0; 1215 iowrite32(qp->rx_index, &qp->rx_info->entry); 1216 return 0; 1217 } 1218 1219 if (hdr->ver != (u32)qp->rx_pkts) { 1220 dev_dbg(&qp->ndev->pdev->dev, 1221 "version mismatch, expected %llu - got %u\n", 1222 qp->rx_pkts, hdr->ver); 1223 qp->rx_err_ver++; 1224 return -EIO; 1225 } 1226 1227 entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q); 1228 if (!entry) { 1229 dev_dbg(&qp->ndev->pdev->dev, "no receive buffer\n"); 1230 qp->rx_err_no_buf++; 1231 1232 rc = -ENOMEM; 1233 goto err; 1234 } 1235 1236 if (hdr->len > entry->len) { 1237 dev_dbg(&qp->ndev->pdev->dev, 1238 "receive buffer overflow! Wanted %d got %d\n", 1239 hdr->len, entry->len); 1240 qp->rx_err_oflow++; 1241 1242 rc = -EIO; 1243 goto err; 1244 } 1245 1246 dev_dbg(&qp->ndev->pdev->dev, 1247 "RX OK index %u ver %u size %d into buf size %d\n", 1248 qp->rx_index, hdr->ver, hdr->len, entry->len); 1249 1250 qp->rx_bytes += hdr->len; 1251 qp->rx_pkts++; 1252 1253 entry->index = qp->rx_index; 1254 entry->rx_hdr = hdr; 1255 1256 ntb_async_rx(entry, offset, hdr->len); 1257 1258 qp->rx_index++; 1259 qp->rx_index %= qp->rx_max_entry; 1260 1261 return 0; 1262 1263 err: 1264 /* FIXME: if this syncrhonous update of the rx_index gets ahead of 1265 * asyncrhonous ntb_rx_copy_callback of previous entry, there are three 1266 * scenarios: 1267 * 1268 * 1) The peer might miss this update, but observe the update 1269 * from the memcpy completion callback. In this case, the buffer will 1270 * not be freed on the peer to be reused for a different packet. The 1271 * successful rx of a later packet would clear the condition, but the 1272 * condition could persist if several rx fail in a row. 1273 * 1274 * 2) The peer may observe this update before the asyncrhonous copy of 1275 * prior packets is completed. The peer may overwrite the buffers of 1276 * the prior packets before they are copied. 1277 * 1278 * 3) Both: the peer may observe the update, and then observe the index 1279 * decrement by the asynchronous completion callback. Who knows what 1280 * badness that will cause. 1281 */ 1282 hdr->flags = 0; 1283 iowrite32(qp->rx_index, &qp->rx_info->entry); 1284 1285 return rc; 1286 } 1287 1288 static void ntb_transport_rxc_db(unsigned long data) 1289 { 1290 struct ntb_transport_qp *qp = (void *)data; 1291 int rc, i; 1292 1293 dev_dbg(&qp->ndev->pdev->dev, "%s: doorbell %d received\n", 1294 __func__, qp->qp_num); 1295 1296 /* Limit the number of packets processed in a single interrupt to 1297 * provide fairness to others 1298 */ 1299 for (i = 0; i < qp->rx_max_entry; i++) { 1300 rc = ntb_process_rxc(qp); 1301 if (rc) 1302 break; 1303 } 1304 1305 if (qp->dma_chan) 1306 dma_async_issue_pending(qp->dma_chan); 1307 1308 if (i == qp->rx_max_entry) { 1309 /* there is more work to do */ 1310 tasklet_schedule(&qp->rxc_db_work); 1311 } else if (ntb_db_read(qp->ndev) & BIT_ULL(qp->qp_num)) { 1312 /* the doorbell bit is set: clear it */ 1313 ntb_db_clear(qp->ndev, BIT_ULL(qp->qp_num)); 1314 /* ntb_db_read ensures ntb_db_clear write is committed */ 1315 ntb_db_read(qp->ndev); 1316 1317 /* an interrupt may have arrived between finishing 1318 * ntb_process_rxc and clearing the doorbell bit: 1319 * there might be some more work to do. 1320 */ 1321 tasklet_schedule(&qp->rxc_db_work); 1322 } 1323 } 1324 1325 static void ntb_tx_copy_callback(void *data) 1326 { 1327 struct ntb_queue_entry *entry = data; 1328 struct ntb_transport_qp *qp = entry->qp; 1329 struct ntb_payload_header __iomem *hdr = entry->tx_hdr; 1330 1331 iowrite32(entry->flags | DESC_DONE_FLAG, &hdr->flags); 1332 1333 ntb_peer_db_set(qp->ndev, BIT_ULL(qp->qp_num)); 1334 1335 /* The entry length can only be zero if the packet is intended to be a 1336 * "link down" or similar. Since no payload is being sent in these 1337 * cases, there is nothing to add to the completion queue. 1338 */ 1339 if (entry->len > 0) { 1340 qp->tx_bytes += entry->len; 1341 1342 if (qp->tx_handler) 1343 qp->tx_handler(qp, qp->cb_data, entry->cb_data, 1344 entry->len); 1345 } 1346 1347 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q); 1348 } 1349 1350 static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset) 1351 { 1352 memcpy_toio(offset, entry->buf, entry->len); 1353 1354 /* Ensure that the data is fully copied out before setting the flags */ 1355 wmb(); 1356 1357 ntb_tx_copy_callback(entry); 1358 } 1359 1360 static void ntb_async_tx(struct ntb_transport_qp *qp, 1361 struct ntb_queue_entry *entry) 1362 { 1363 struct ntb_payload_header __iomem *hdr; 1364 struct dma_async_tx_descriptor *txd; 1365 struct dma_chan *chan = qp->dma_chan; 1366 struct dma_device *device; 1367 size_t dest_off, buff_off; 1368 struct dmaengine_unmap_data *unmap; 1369 dma_addr_t dest; 1370 dma_cookie_t cookie; 1371 void __iomem *offset; 1372 size_t len = entry->len; 1373 void *buf = entry->buf; 1374 1375 offset = qp->tx_mw + qp->tx_max_frame * qp->tx_index; 1376 hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header); 1377 entry->tx_hdr = hdr; 1378 1379 iowrite32(entry->len, &hdr->len); 1380 iowrite32((u32)qp->tx_pkts, &hdr->ver); 1381 1382 if (!chan) 1383 goto err; 1384 1385 if (len < copy_bytes) 1386 goto err; 1387 1388 device = chan->device; 1389 dest = qp->tx_mw_phys + qp->tx_max_frame * qp->tx_index; 1390 buff_off = (size_t)buf & ~PAGE_MASK; 1391 dest_off = (size_t)dest & ~PAGE_MASK; 1392 1393 if (!is_dma_copy_aligned(device, buff_off, dest_off, len)) 1394 goto err; 1395 1396 unmap = dmaengine_get_unmap_data(device->dev, 1, GFP_NOWAIT); 1397 if (!unmap) 1398 goto err; 1399 1400 unmap->len = len; 1401 unmap->addr[0] = dma_map_page(device->dev, virt_to_page(buf), 1402 buff_off, len, DMA_TO_DEVICE); 1403 if (dma_mapping_error(device->dev, unmap->addr[0])) 1404 goto err_get_unmap; 1405 1406 unmap->to_cnt = 1; 1407 1408 txd = device->device_prep_dma_memcpy(chan, dest, unmap->addr[0], len, 1409 DMA_PREP_INTERRUPT); 1410 if (!txd) 1411 goto err_get_unmap; 1412 1413 txd->callback = ntb_tx_copy_callback; 1414 txd->callback_param = entry; 1415 dma_set_unmap(txd, unmap); 1416 1417 cookie = dmaengine_submit(txd); 1418 if (dma_submit_error(cookie)) 1419 goto err_set_unmap; 1420 1421 dmaengine_unmap_put(unmap); 1422 1423 dma_async_issue_pending(chan); 1424 qp->tx_async++; 1425 1426 return; 1427 err_set_unmap: 1428 dmaengine_unmap_put(unmap); 1429 err_get_unmap: 1430 dmaengine_unmap_put(unmap); 1431 err: 1432 ntb_memcpy_tx(entry, offset); 1433 qp->tx_memcpy++; 1434 } 1435 1436 static int ntb_process_tx(struct ntb_transport_qp *qp, 1437 struct ntb_queue_entry *entry) 1438 { 1439 if (qp->tx_index == qp->remote_rx_info->entry) { 1440 qp->tx_ring_full++; 1441 return -EAGAIN; 1442 } 1443 1444 if (entry->len > qp->tx_max_frame - sizeof(struct ntb_payload_header)) { 1445 if (qp->tx_handler) 1446 qp->tx_handler(qp->cb_data, qp, NULL, -EIO); 1447 1448 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, 1449 &qp->tx_free_q); 1450 return 0; 1451 } 1452 1453 ntb_async_tx(qp, entry); 1454 1455 qp->tx_index++; 1456 qp->tx_index %= qp->tx_max_entry; 1457 1458 qp->tx_pkts++; 1459 1460 return 0; 1461 } 1462 1463 static void ntb_send_link_down(struct ntb_transport_qp *qp) 1464 { 1465 struct pci_dev *pdev = qp->ndev->pdev; 1466 struct ntb_queue_entry *entry; 1467 int i, rc; 1468 1469 if (!qp->link_is_up) 1470 return; 1471 1472 qp->link_is_up = false; 1473 dev_info(&pdev->dev, "qp %d: Link Down\n", qp->qp_num); 1474 1475 for (i = 0; i < NTB_LINK_DOWN_TIMEOUT; i++) { 1476 entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q); 1477 if (entry) 1478 break; 1479 msleep(100); 1480 } 1481 1482 if (!entry) 1483 return; 1484 1485 entry->cb_data = NULL; 1486 entry->buf = NULL; 1487 entry->len = 0; 1488 entry->flags = LINK_DOWN_FLAG; 1489 1490 rc = ntb_process_tx(qp, entry); 1491 if (rc) 1492 dev_err(&pdev->dev, "ntb: QP%d unable to send linkdown msg\n", 1493 qp->qp_num); 1494 } 1495 1496 /** 1497 * ntb_transport_create_queue - Create a new NTB transport layer queue 1498 * @rx_handler: receive callback function 1499 * @tx_handler: transmit callback function 1500 * @event_handler: event callback function 1501 * 1502 * Create a new NTB transport layer queue and provide the queue with a callback 1503 * routine for both transmit and receive. The receive callback routine will be 1504 * used to pass up data when the transport has received it on the queue. The 1505 * transmit callback routine will be called when the transport has completed the 1506 * transmission of the data on the queue and the data is ready to be freed. 1507 * 1508 * RETURNS: pointer to newly created ntb_queue, NULL on error. 1509 */ 1510 struct ntb_transport_qp * 1511 ntb_transport_create_queue(void *data, struct device *client_dev, 1512 const struct ntb_queue_handlers *handlers) 1513 { 1514 struct ntb_dev *ndev; 1515 struct pci_dev *pdev; 1516 struct ntb_transport_ctx *nt; 1517 struct ntb_queue_entry *entry; 1518 struct ntb_transport_qp *qp; 1519 u64 qp_bit; 1520 unsigned int free_queue; 1521 int i; 1522 1523 ndev = dev_ntb(client_dev->parent); 1524 pdev = ndev->pdev; 1525 nt = ndev->ctx; 1526 1527 free_queue = ffs(nt->qp_bitmap); 1528 if (!free_queue) 1529 goto err; 1530 1531 /* decrement free_queue to make it zero based */ 1532 free_queue--; 1533 1534 qp = &nt->qp_vec[free_queue]; 1535 qp_bit = BIT_ULL(qp->qp_num); 1536 1537 nt->qp_bitmap_free &= ~qp_bit; 1538 1539 qp->cb_data = data; 1540 qp->rx_handler = handlers->rx_handler; 1541 qp->tx_handler = handlers->tx_handler; 1542 qp->event_handler = handlers->event_handler; 1543 1544 dmaengine_get(); 1545 qp->dma_chan = dma_find_channel(DMA_MEMCPY); 1546 if (!qp->dma_chan) { 1547 dmaengine_put(); 1548 dev_info(&pdev->dev, "Unable to allocate DMA channel, using CPU instead\n"); 1549 } 1550 1551 for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) { 1552 entry = kzalloc(sizeof(*entry), GFP_ATOMIC); 1553 if (!entry) 1554 goto err1; 1555 1556 entry->qp = qp; 1557 ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry, 1558 &qp->rx_free_q); 1559 } 1560 1561 for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) { 1562 entry = kzalloc(sizeof(*entry), GFP_ATOMIC); 1563 if (!entry) 1564 goto err2; 1565 1566 entry->qp = qp; 1567 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, 1568 &qp->tx_free_q); 1569 } 1570 1571 ntb_db_clear(qp->ndev, qp_bit); 1572 ntb_db_clear_mask(qp->ndev, qp_bit); 1573 1574 dev_info(&pdev->dev, "NTB Transport QP %d created\n", qp->qp_num); 1575 1576 return qp; 1577 1578 err2: 1579 while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q))) 1580 kfree(entry); 1581 err1: 1582 while ((entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q))) 1583 kfree(entry); 1584 if (qp->dma_chan) 1585 dmaengine_put(); 1586 nt->qp_bitmap_free |= qp_bit; 1587 err: 1588 return NULL; 1589 } 1590 EXPORT_SYMBOL_GPL(ntb_transport_create_queue); 1591 1592 /** 1593 * ntb_transport_free_queue - Frees NTB transport queue 1594 * @qp: NTB queue to be freed 1595 * 1596 * Frees NTB transport queue 1597 */ 1598 void ntb_transport_free_queue(struct ntb_transport_qp *qp) 1599 { 1600 struct ntb_transport_ctx *nt = qp->transport; 1601 struct pci_dev *pdev; 1602 struct ntb_queue_entry *entry; 1603 u64 qp_bit; 1604 1605 if (!qp) 1606 return; 1607 1608 pdev = qp->ndev->pdev; 1609 1610 if (qp->dma_chan) { 1611 struct dma_chan *chan = qp->dma_chan; 1612 /* Putting the dma_chan to NULL will force any new traffic to be 1613 * processed by the CPU instead of the DAM engine 1614 */ 1615 qp->dma_chan = NULL; 1616 1617 /* Try to be nice and wait for any queued DMA engine 1618 * transactions to process before smashing it with a rock 1619 */ 1620 dma_sync_wait(chan, qp->last_cookie); 1621 dmaengine_terminate_all(chan); 1622 dmaengine_put(); 1623 } 1624 1625 qp_bit = BIT_ULL(qp->qp_num); 1626 1627 ntb_db_set_mask(qp->ndev, qp_bit); 1628 tasklet_disable(&qp->rxc_db_work); 1629 1630 cancel_delayed_work_sync(&qp->link_work); 1631 1632 qp->cb_data = NULL; 1633 qp->rx_handler = NULL; 1634 qp->tx_handler = NULL; 1635 qp->event_handler = NULL; 1636 1637 while ((entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q))) 1638 kfree(entry); 1639 1640 while ((entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q))) { 1641 dev_warn(&pdev->dev, "Freeing item from a non-empty queue\n"); 1642 kfree(entry); 1643 } 1644 1645 while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q))) 1646 kfree(entry); 1647 1648 nt->qp_bitmap_free |= qp_bit; 1649 1650 dev_info(&pdev->dev, "NTB Transport QP %d freed\n", qp->qp_num); 1651 } 1652 EXPORT_SYMBOL_GPL(ntb_transport_free_queue); 1653 1654 /** 1655 * ntb_transport_rx_remove - Dequeues enqueued rx packet 1656 * @qp: NTB queue to be freed 1657 * @len: pointer to variable to write enqueued buffers length 1658 * 1659 * Dequeues unused buffers from receive queue. Should only be used during 1660 * shutdown of qp. 1661 * 1662 * RETURNS: NULL error value on error, or void* for success. 1663 */ 1664 void *ntb_transport_rx_remove(struct ntb_transport_qp *qp, unsigned int *len) 1665 { 1666 struct ntb_queue_entry *entry; 1667 void *buf; 1668 1669 if (!qp || qp->client_ready) 1670 return NULL; 1671 1672 entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q); 1673 if (!entry) 1674 return NULL; 1675 1676 buf = entry->cb_data; 1677 *len = entry->len; 1678 1679 ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry, &qp->rx_free_q); 1680 1681 return buf; 1682 } 1683 EXPORT_SYMBOL_GPL(ntb_transport_rx_remove); 1684 1685 /** 1686 * ntb_transport_rx_enqueue - Enqueue a new NTB queue entry 1687 * @qp: NTB transport layer queue the entry is to be enqueued on 1688 * @cb: per buffer pointer for callback function to use 1689 * @data: pointer to data buffer that incoming packets will be copied into 1690 * @len: length of the data buffer 1691 * 1692 * Enqueue a new receive buffer onto the transport queue into which a NTB 1693 * payload can be received into. 1694 * 1695 * RETURNS: An appropriate -ERRNO error value on error, or zero for success. 1696 */ 1697 int ntb_transport_rx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data, 1698 unsigned int len) 1699 { 1700 struct ntb_queue_entry *entry; 1701 1702 if (!qp) 1703 return -EINVAL; 1704 1705 entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q); 1706 if (!entry) 1707 return -ENOMEM; 1708 1709 entry->cb_data = cb; 1710 entry->buf = data; 1711 entry->len = len; 1712 1713 ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry, &qp->rx_pend_q); 1714 1715 return 0; 1716 } 1717 EXPORT_SYMBOL_GPL(ntb_transport_rx_enqueue); 1718 1719 /** 1720 * ntb_transport_tx_enqueue - Enqueue a new NTB queue entry 1721 * @qp: NTB transport layer queue the entry is to be enqueued on 1722 * @cb: per buffer pointer for callback function to use 1723 * @data: pointer to data buffer that will be sent 1724 * @len: length of the data buffer 1725 * 1726 * Enqueue a new transmit buffer onto the transport queue from which a NTB 1727 * payload will be transmitted. This assumes that a lock is being held to 1728 * serialize access to the qp. 1729 * 1730 * RETURNS: An appropriate -ERRNO error value on error, or zero for success. 1731 */ 1732 int ntb_transport_tx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data, 1733 unsigned int len) 1734 { 1735 struct ntb_queue_entry *entry; 1736 int rc; 1737 1738 if (!qp || !qp->link_is_up || !len) 1739 return -EINVAL; 1740 1741 entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q); 1742 if (!entry) { 1743 qp->tx_err_no_buf++; 1744 return -ENOMEM; 1745 } 1746 1747 entry->cb_data = cb; 1748 entry->buf = data; 1749 entry->len = len; 1750 entry->flags = 0; 1751 1752 rc = ntb_process_tx(qp, entry); 1753 if (rc) 1754 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, 1755 &qp->tx_free_q); 1756 1757 return rc; 1758 } 1759 EXPORT_SYMBOL_GPL(ntb_transport_tx_enqueue); 1760 1761 /** 1762 * ntb_transport_link_up - Notify NTB transport of client readiness to use queue 1763 * @qp: NTB transport layer queue to be enabled 1764 * 1765 * Notify NTB transport layer of client readiness to use queue 1766 */ 1767 void ntb_transport_link_up(struct ntb_transport_qp *qp) 1768 { 1769 if (!qp) 1770 return; 1771 1772 qp->client_ready = true; 1773 1774 if (qp->transport->link_is_up) 1775 schedule_delayed_work(&qp->link_work, 0); 1776 } 1777 EXPORT_SYMBOL_GPL(ntb_transport_link_up); 1778 1779 /** 1780 * ntb_transport_link_down - Notify NTB transport to no longer enqueue data 1781 * @qp: NTB transport layer queue to be disabled 1782 * 1783 * Notify NTB transport layer of client's desire to no longer receive data on 1784 * transport queue specified. It is the client's responsibility to ensure all 1785 * entries on queue are purged or otherwise handled appropriately. 1786 */ 1787 void ntb_transport_link_down(struct ntb_transport_qp *qp) 1788 { 1789 struct pci_dev *pdev; 1790 int val; 1791 1792 if (!qp) 1793 return; 1794 1795 pdev = qp->ndev->pdev; 1796 qp->client_ready = false; 1797 1798 val = ntb_spad_read(qp->ndev, QP_LINKS); 1799 1800 ntb_peer_spad_write(qp->ndev, QP_LINKS, 1801 val & ~BIT(qp->qp_num)); 1802 1803 if (qp->link_is_up) 1804 ntb_send_link_down(qp); 1805 else 1806 cancel_delayed_work_sync(&qp->link_work); 1807 } 1808 EXPORT_SYMBOL_GPL(ntb_transport_link_down); 1809 1810 /** 1811 * ntb_transport_link_query - Query transport link state 1812 * @qp: NTB transport layer queue to be queried 1813 * 1814 * Query connectivity to the remote system of the NTB transport queue 1815 * 1816 * RETURNS: true for link up or false for link down 1817 */ 1818 bool ntb_transport_link_query(struct ntb_transport_qp *qp) 1819 { 1820 if (!qp) 1821 return false; 1822 1823 return qp->link_is_up; 1824 } 1825 EXPORT_SYMBOL_GPL(ntb_transport_link_query); 1826 1827 /** 1828 * ntb_transport_qp_num - Query the qp number 1829 * @qp: NTB transport layer queue to be queried 1830 * 1831 * Query qp number of the NTB transport queue 1832 * 1833 * RETURNS: a zero based number specifying the qp number 1834 */ 1835 unsigned char ntb_transport_qp_num(struct ntb_transport_qp *qp) 1836 { 1837 if (!qp) 1838 return 0; 1839 1840 return qp->qp_num; 1841 } 1842 EXPORT_SYMBOL_GPL(ntb_transport_qp_num); 1843 1844 /** 1845 * ntb_transport_max_size - Query the max payload size of a qp 1846 * @qp: NTB transport layer queue to be queried 1847 * 1848 * Query the maximum payload size permissible on the given qp 1849 * 1850 * RETURNS: the max payload size of a qp 1851 */ 1852 unsigned int ntb_transport_max_size(struct ntb_transport_qp *qp) 1853 { 1854 unsigned int max; 1855 1856 if (!qp) 1857 return 0; 1858 1859 if (!qp->dma_chan) 1860 return qp->tx_max_frame - sizeof(struct ntb_payload_header); 1861 1862 /* If DMA engine usage is possible, try to find the max size for that */ 1863 max = qp->tx_max_frame - sizeof(struct ntb_payload_header); 1864 max -= max % (1 << qp->dma_chan->device->copy_align); 1865 1866 return max; 1867 } 1868 EXPORT_SYMBOL_GPL(ntb_transport_max_size); 1869 1870 static void ntb_transport_doorbell_callback(void *data, int vector) 1871 { 1872 struct ntb_transport_ctx *nt = data; 1873 struct ntb_transport_qp *qp; 1874 u64 db_bits; 1875 unsigned int qp_num; 1876 1877 db_bits = (nt->qp_bitmap & ~nt->qp_bitmap_free & 1878 ntb_db_vector_mask(nt->ndev, vector)); 1879 1880 while (db_bits) { 1881 qp_num = __ffs(db_bits); 1882 qp = &nt->qp_vec[qp_num]; 1883 1884 tasklet_schedule(&qp->rxc_db_work); 1885 1886 db_bits &= ~BIT_ULL(qp_num); 1887 } 1888 } 1889 1890 static const struct ntb_ctx_ops ntb_transport_ops = { 1891 .link_event = ntb_transport_event_callback, 1892 .db_event = ntb_transport_doorbell_callback, 1893 }; 1894 1895 static struct ntb_client ntb_transport_client = { 1896 .ops = { 1897 .probe = ntb_transport_probe, 1898 .remove = ntb_transport_free, 1899 }, 1900 }; 1901 1902 static int __init ntb_transport_init(void) 1903 { 1904 int rc; 1905 1906 if (debugfs_initialized()) 1907 nt_debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL); 1908 1909 rc = bus_register(&ntb_transport_bus); 1910 if (rc) 1911 goto err_bus; 1912 1913 rc = ntb_register_client(&ntb_transport_client); 1914 if (rc) 1915 goto err_client; 1916 1917 return 0; 1918 1919 err_client: 1920 bus_unregister(&ntb_transport_bus); 1921 err_bus: 1922 debugfs_remove_recursive(nt_debugfs_dir); 1923 return rc; 1924 } 1925 module_init(ntb_transport_init); 1926 1927 static void __exit ntb_transport_exit(void) 1928 { 1929 debugfs_remove_recursive(nt_debugfs_dir); 1930 1931 ntb_unregister_client(&ntb_transport_client); 1932 bus_unregister(&ntb_transport_bus); 1933 } 1934 module_exit(ntb_transport_exit); 1935