ntb_transport.c 37.8 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
/*
 * This file is provided under a dual BSD/GPLv2 license.  When using or
 *   redistributing this file, you may do so under either license.
 *
 *   GPL LICENSE SUMMARY
 *
 *   Copyright(c) 2012 Intel Corporation. All rights reserved.
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of version 2 of the GNU General Public License as
 *   published by the Free Software Foundation.
 *
 *   BSD LICENSE
 *
 *   Copyright(c) 2012 Intel Corporation. All rights reserved.
 *
 *   Redistribution and use in source and binary forms, with or without
 *   modification, are permitted provided that the following conditions
 *   are met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copy
 *       notice, this list of conditions and the following disclaimer in
 *       the documentation and/or other materials provided with the
 *       distribution.
 *     * Neither the name of Intel Corporation nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Intel PCIe NTB Linux driver
 *
 * Contact Information:
 * Jon Mason <jon.mason@intel.com>
 */
#include <linux/debugfs.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/errno.h>
#include <linux/export.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/ntb.h>
#include "ntb_hw.h"

Jon Mason's avatar
Jon Mason committed
61
#define NTB_TRANSPORT_VERSION	3
62

63
static unsigned int transport_mtu = 0x401E;
64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80
module_param(transport_mtu, uint, 0644);
MODULE_PARM_DESC(transport_mtu, "Maximum size of NTB transport packets");

static unsigned char max_num_clients = 2;
module_param(max_num_clients, byte, 0644);
MODULE_PARM_DESC(max_num_clients, "Maximum number of NTB transport clients");

struct ntb_queue_entry {
	/* ntb_queue list reference */
	struct list_head entry;
	/* pointers to data to be transfered */
	void *cb_data;
	void *buf;
	unsigned int len;
	unsigned int flags;
};

Jon Mason's avatar
Jon Mason committed
81 82 83 84
struct ntb_rx_info {
	unsigned int entry;
};

85 86 87 88 89 90 91 92 93
struct ntb_transport_qp {
	struct ntb_transport *transport;
	struct ntb_device *ndev;
	void *cb_data;

	bool client_ready;
	bool qp_link;
	u8 qp_num;	/* Only 64 QP's are allowed.  0-63 */

Jon Mason's avatar
Jon Mason committed
94
	struct ntb_rx_info __iomem *rx_info;
Jon Mason's avatar
Jon Mason committed
95 96
	struct ntb_rx_info *remote_rx_info;

97 98 99 100
	void (*tx_handler) (struct ntb_transport_qp *qp, void *qp_data,
			    void *data, int len);
	struct list_head tx_free_q;
	spinlock_t ntb_tx_free_q_lock;
Jon Mason's avatar
Jon Mason committed
101
	void __iomem *tx_mw;
Jon Mason's avatar
Jon Mason committed
102 103
	unsigned int tx_index;
	unsigned int tx_max_entry;
104
	unsigned int tx_max_frame;
105 106 107 108 109 110 111 112

	void (*rx_handler) (struct ntb_transport_qp *qp, void *qp_data,
			    void *data, int len);
	struct tasklet_struct rx_work;
	struct list_head rx_pend_q;
	struct list_head rx_free_q;
	spinlock_t ntb_rx_pend_q_lock;
	spinlock_t ntb_rx_free_q_lock;
Jon Mason's avatar
Jon Mason committed
113 114 115
	void *rx_buff;
	unsigned int rx_index;
	unsigned int rx_max_entry;
116
	unsigned int rx_max_frame;
117 118 119

	void (*event_handler) (void *data, int status);
	struct delayed_work link_work;
120
	struct work_struct link_cleanup;
121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158

	struct dentry *debugfs_dir;
	struct dentry *debugfs_stats;

	/* Stats */
	u64 rx_bytes;
	u64 rx_pkts;
	u64 rx_ring_empty;
	u64 rx_err_no_buf;
	u64 rx_err_oflow;
	u64 rx_err_ver;
	u64 tx_bytes;
	u64 tx_pkts;
	u64 tx_ring_full;
};

struct ntb_transport_mw {
	size_t size;
	void *virt_addr;
	dma_addr_t dma_addr;
};

struct ntb_transport_client_dev {
	struct list_head entry;
	struct device dev;
};

struct ntb_transport {
	struct list_head entry;
	struct list_head client_devs;

	struct ntb_device *ndev;
	struct ntb_transport_mw mw[NTB_NUM_MW];
	struct ntb_transport_qp *qps;
	unsigned int max_qps;
	unsigned long qp_bitmap;
	bool transport_link;
	struct delayed_work link_work;
159
	struct work_struct link_cleanup;
160 161 162 163 164 165 166 167
};

enum {
	DESC_DONE_FLAG = 1 << 0,
	LINK_DOWN_FLAG = 1 << 1,
};

struct ntb_payload_header {
Jon Mason's avatar
Jon Mason committed
168
	unsigned int ver;
169 170 171 172 173 174 175
	unsigned int len;
	unsigned int flags;
};

enum {
	VERSION = 0,
	QP_LINKS,
Jon Mason's avatar
Jon Mason committed
176 177 178 179 180 181
	NUM_QPS,
	NUM_MWS,
	MW0_SZ_HIGH,
	MW0_SZ_LOW,
	MW1_SZ_HIGH,
	MW1_SZ_LOW,
182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223
	MAX_SPAD,
};

#define QP_TO_MW(qp)		((qp) % NTB_NUM_MW)
#define NTB_QP_DEF_NUM_ENTRIES	100
#define NTB_LINK_DOWN_TIMEOUT	10

static int ntb_match_bus(struct device *dev, struct device_driver *drv)
{
	return !strncmp(dev_name(dev), drv->name, strlen(drv->name));
}

static int ntb_client_probe(struct device *dev)
{
	const struct ntb_client *drv = container_of(dev->driver,
						    struct ntb_client, driver);
	struct pci_dev *pdev = container_of(dev->parent, struct pci_dev, dev);
	int rc = -EINVAL;

	get_device(dev);
	if (drv && drv->probe)
		rc = drv->probe(pdev);
	if (rc)
		put_device(dev);

	return rc;
}

static int ntb_client_remove(struct device *dev)
{
	const struct ntb_client *drv = container_of(dev->driver,
						    struct ntb_client, driver);
	struct pci_dev *pdev = container_of(dev->parent, struct pci_dev, dev);

	if (drv && drv->remove)
		drv->remove(pdev);

	put_device(dev);

	return 0;
}

Jon Mason's avatar
Jon Mason committed
224
static struct bus_type ntb_bus_type = {
225 226 227 228 229 230 231 232
	.name = "ntb_bus",
	.match = ntb_match_bus,
	.probe = ntb_client_probe,
	.remove = ntb_client_remove,
};

static LIST_HEAD(ntb_transport_list);

233
static int ntb_bus_init(struct ntb_transport *nt)
234 235 236 237 238 239 240 241 242 243 244 245
{
	if (list_empty(&ntb_transport_list)) {
		int rc = bus_register(&ntb_bus_type);
		if (rc)
			return rc;
	}

	list_add(&nt->entry, &ntb_transport_list);

	return 0;
}

246
static void ntb_bus_remove(struct ntb_transport *nt)
247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301
{
	struct ntb_transport_client_dev *client_dev, *cd;

	list_for_each_entry_safe(client_dev, cd, &nt->client_devs, entry) {
		dev_err(client_dev->dev.parent, "%s still attached to bus, removing\n",
			dev_name(&client_dev->dev));
		list_del(&client_dev->entry);
		device_unregister(&client_dev->dev);
	}

	list_del(&nt->entry);

	if (list_empty(&ntb_transport_list))
		bus_unregister(&ntb_bus_type);
}

static void ntb_client_release(struct device *dev)
{
	struct ntb_transport_client_dev *client_dev;
	client_dev = container_of(dev, struct ntb_transport_client_dev, dev);

	kfree(client_dev);
}

/**
 * ntb_unregister_client_dev - Unregister NTB client device
 * @device_name: Name of NTB client device
 *
 * Unregister an NTB client device with the NTB transport layer
 */
void ntb_unregister_client_dev(char *device_name)
{
	struct ntb_transport_client_dev *client, *cd;
	struct ntb_transport *nt;

	list_for_each_entry(nt, &ntb_transport_list, entry)
		list_for_each_entry_safe(client, cd, &nt->client_devs, entry)
			if (!strncmp(dev_name(&client->dev), device_name,
				     strlen(device_name))) {
				list_del(&client->entry);
				device_unregister(&client->dev);
			}
}
EXPORT_SYMBOL_GPL(ntb_unregister_client_dev);

/**
 * ntb_register_client_dev - Register NTB client device
 * @device_name: Name of NTB client device
 *
 * Register an NTB client device with the NTB transport layer
 */
int ntb_register_client_dev(char *device_name)
{
	struct ntb_transport_client_dev *client_dev;
	struct ntb_transport *nt;
Jon Mason's avatar
Jon Mason committed
302
	int rc, i = 0;
303

304 305 306
	if (list_empty(&ntb_transport_list))
		return -ENODEV;

307 308 309 310 311 312 313 314 315 316 317 318 319
	list_for_each_entry(nt, &ntb_transport_list, entry) {
		struct device *dev;

		client_dev = kzalloc(sizeof(struct ntb_transport_client_dev),
				     GFP_KERNEL);
		if (!client_dev) {
			rc = -ENOMEM;
			goto err;
		}

		dev = &client_dev->dev;

		/* setup and register client devices */
Jon Mason's avatar
Jon Mason committed
320
		dev_set_name(dev, "%s%d", device_name, i);
321 322 323 324 325 326 327 328 329 330 331
		dev->bus = &ntb_bus_type;
		dev->release = ntb_client_release;
		dev->parent = &ntb_query_pdev(nt->ndev)->dev;

		rc = device_register(dev);
		if (rc) {
			kfree(client_dev);
			goto err;
		}

		list_add_tail(&client_dev->entry, &nt->client_devs);
Jon Mason's avatar
Jon Mason committed
332
		i++;
333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355
	}

	return 0;

err:
	ntb_unregister_client_dev(device_name);

	return rc;
}
EXPORT_SYMBOL_GPL(ntb_register_client_dev);

/**
 * ntb_register_client - Register NTB client driver
 * @drv: NTB client driver to be registered
 *
 * Register an NTB client driver with the NTB transport layer
 *
 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 */
int ntb_register_client(struct ntb_client *drv)
{
	drv->driver.bus = &ntb_bus_type;

356 357 358
	if (list_empty(&ntb_transport_list))
		return -ENODEV;

359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380
	return driver_register(&drv->driver);
}
EXPORT_SYMBOL_GPL(ntb_register_client);

/**
 * ntb_unregister_client - Unregister NTB client driver
 * @drv: NTB client driver to be unregistered
 *
 * Unregister an NTB client driver with the NTB transport layer
 *
 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 */
void ntb_unregister_client(struct ntb_client *drv)
{
	driver_unregister(&drv->driver);
}
EXPORT_SYMBOL_GPL(ntb_unregister_client);

static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count,
			    loff_t *offp)
{
	struct ntb_transport_qp *qp;
381
	char *buf;
382 383
	ssize_t ret, out_offset, out_count;

384 385 386 387 388
	out_count = 600;

	buf = kmalloc(out_count, GFP_KERNEL);
	if (!buf)
		return -ENOMEM;
389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406

	qp = filp->private_data;
	out_offset = 0;
	out_offset += snprintf(buf + out_offset, out_count - out_offset,
			       "NTB QP stats\n");
	out_offset += snprintf(buf + out_offset, out_count - out_offset,
			       "rx_bytes - \t%llu\n", qp->rx_bytes);
	out_offset += snprintf(buf + out_offset, out_count - out_offset,
			       "rx_pkts - \t%llu\n", qp->rx_pkts);
	out_offset += snprintf(buf + out_offset, out_count - out_offset,
			       "rx_ring_empty - %llu\n", qp->rx_ring_empty);
	out_offset += snprintf(buf + out_offset, out_count - out_offset,
			       "rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
	out_offset += snprintf(buf + out_offset, out_count - out_offset,
			       "rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
	out_offset += snprintf(buf + out_offset, out_count - out_offset,
			       "rx_err_ver - \t%llu\n", qp->rx_err_ver);
	out_offset += snprintf(buf + out_offset, out_count - out_offset,
Jon Mason's avatar
Jon Mason committed
407
			       "rx_buff - \t%p\n", qp->rx_buff);
408
	out_offset += snprintf(buf + out_offset, out_count - out_offset,
Jon Mason's avatar
Jon Mason committed
409
			       "rx_index - \t%u\n", qp->rx_index);
410
	out_offset += snprintf(buf + out_offset, out_count - out_offset,
Jon Mason's avatar
Jon Mason committed
411
			       "rx_max_entry - \t%u\n", qp->rx_max_entry);
412 413 414 415 416 417 418 419

	out_offset += snprintf(buf + out_offset, out_count - out_offset,
			       "tx_bytes - \t%llu\n", qp->tx_bytes);
	out_offset += snprintf(buf + out_offset, out_count - out_offset,
			       "tx_pkts - \t%llu\n", qp->tx_pkts);
	out_offset += snprintf(buf + out_offset, out_count - out_offset,
			       "tx_ring_full - \t%llu\n", qp->tx_ring_full);
	out_offset += snprintf(buf + out_offset, out_count - out_offset,
Jon Mason's avatar
Jon Mason committed
420
			       "tx_mw - \t%p\n", qp->tx_mw);
421
	out_offset += snprintf(buf + out_offset, out_count - out_offset,
Jon Mason's avatar
Jon Mason committed
422
			       "tx_index - \t%u\n", qp->tx_index);
423
	out_offset += snprintf(buf + out_offset, out_count - out_offset,
Jon Mason's avatar
Jon Mason committed
424
			       "tx_max_entry - \t%u\n", qp->tx_max_entry);
425 426

	out_offset += snprintf(buf + out_offset, out_count - out_offset,
427
			       "\nQP Link %s\n", (qp->qp_link == NTB_LINK_UP) ?
428
			       "Up" : "Down");
429 430
	if (out_offset > out_count)
		out_offset = out_count;
431 432

	ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
433
	kfree(buf);
434 435 436 437 438
	return ret;
}

static const struct file_operations ntb_qp_debugfs_stats = {
	.owner = THIS_MODULE,
Jon Mason's avatar
Jon Mason committed
439
	.open = simple_open,
440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475
	.read = debugfs_read,
};

static void ntb_list_add(spinlock_t *lock, struct list_head *entry,
			 struct list_head *list)
{
	unsigned long flags;

	spin_lock_irqsave(lock, flags);
	list_add_tail(entry, list);
	spin_unlock_irqrestore(lock, flags);
}

static struct ntb_queue_entry *ntb_list_rm(spinlock_t *lock,
						struct list_head *list)
{
	struct ntb_queue_entry *entry;
	unsigned long flags;

	spin_lock_irqsave(lock, flags);
	if (list_empty(list)) {
		entry = NULL;
		goto out;
	}
	entry = list_first_entry(list, struct ntb_queue_entry, entry);
	list_del(&entry->entry);
out:
	spin_unlock_irqrestore(lock, flags);

	return entry;
}

static void ntb_transport_setup_qp_mw(struct ntb_transport *nt,
				      unsigned int qp_num)
{
	struct ntb_transport_qp *qp = &nt->qps[qp_num];
476
	unsigned int rx_size, num_qps_mw;
477
	u8 mw_num = QP_TO_MW(qp_num);
Jon Mason's avatar
Jon Mason committed
478
	unsigned int i;
479

Jon Mason's avatar
Jon Mason committed
480
	WARN_ON(nt->mw[mw_num].virt_addr == NULL);
481

482 483
	if (nt->max_qps % NTB_NUM_MW && mw_num < nt->max_qps % NTB_NUM_MW)
		num_qps_mw = nt->max_qps / NTB_NUM_MW + 1;
484 485 486
	else
		num_qps_mw = nt->max_qps / NTB_NUM_MW;

Jon Mason's avatar
Jon Mason committed
487 488 489 490 491
	rx_size = (unsigned int) nt->mw[mw_num].size / num_qps_mw;
	qp->remote_rx_info = nt->mw[mw_num].virt_addr +
			     (qp_num / NTB_NUM_MW * rx_size);
	rx_size -= sizeof(struct ntb_rx_info);

Dan Carpenter's avatar
Dan Carpenter committed
492
	qp->rx_buff = qp->remote_rx_info + 1;
493 494
	/* Due to housekeeping, there must be atleast 2 buffs */
	qp->rx_max_frame = min(transport_mtu, rx_size / 2);
Jon Mason's avatar
Jon Mason committed
495 496 497
	qp->rx_max_entry = rx_size / qp->rx_max_frame;
	qp->rx_index = 0;

498
	qp->remote_rx_info->entry = qp->rx_max_entry - 1;
499

500
	/* setup the hdr offsets with 0's */
Jon Mason's avatar
Jon Mason committed
501 502 503
	for (i = 0; i < qp->rx_max_entry; i++) {
		void *offset = qp->rx_buff + qp->rx_max_frame * (i + 1) -
			       sizeof(struct ntb_payload_header);
504
		memset(offset, 0, sizeof(struct ntb_payload_header));
Jon Mason's avatar
Jon Mason committed
505
	}
506 507 508

	qp->rx_pkts = 0;
	qp->tx_pkts = 0;
Jon Mason's avatar
Jon Mason committed
509
	qp->tx_index = 0;
510 511
}

Jon Mason's avatar
Jon Mason committed
512 513 514 515 516 517 518 519 520 521 522 523
static void ntb_free_mw(struct ntb_transport *nt, int num_mw)
{
	struct ntb_transport_mw *mw = &nt->mw[num_mw];
	struct pci_dev *pdev = ntb_query_pdev(nt->ndev);

	if (!mw->virt_addr)
		return;

	dma_free_coherent(&pdev->dev, mw->size, mw->virt_addr, mw->dma_addr);
	mw->virt_addr = NULL;
}

524 525 526 527 528
static int ntb_set_mw(struct ntb_transport *nt, int num_mw, unsigned int size)
{
	struct ntb_transport_mw *mw = &nt->mw[num_mw];
	struct pci_dev *pdev = ntb_query_pdev(nt->ndev);

Jon Mason's avatar
Jon Mason committed
529 530 531 532 533 534 535
	/* No need to re-setup */
	if (mw->size == ALIGN(size, 4096))
		return 0;

	if (mw->size != 0)
		ntb_free_mw(nt, num_mw);

536 537 538 539 540 541
	/* Alloc memory for receiving data.  Must be 4k aligned */
	mw->size = ALIGN(size, 4096);

	mw->virt_addr = dma_alloc_coherent(&pdev->dev, mw->size, &mw->dma_addr,
					   GFP_KERNEL);
	if (!mw->virt_addr) {
Jon Mason's avatar
Jon Mason committed
542
		mw->size = 0;
543 544 545 546 547 548 549 550 551 552 553
		dev_err(&pdev->dev, "Unable to allocate MW buffer of size %d\n",
		       (int) mw->size);
		return -ENOMEM;
	}

	/* Notify HW the memory location of the receive buffer */
	ntb_set_mw_addr(nt->ndev, num_mw, mw->dma_addr);

	return 0;
}

554
static void ntb_qp_link_cleanup(struct work_struct *work)
555
{
556 557 558
	struct ntb_transport_qp *qp = container_of(work,
						   struct ntb_transport_qp,
						   link_cleanup);
559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577
	struct ntb_transport *nt = qp->transport;
	struct pci_dev *pdev = ntb_query_pdev(nt->ndev);

	if (qp->qp_link == NTB_LINK_DOWN) {
		cancel_delayed_work_sync(&qp->link_work);
		return;
	}

	if (qp->event_handler)
		qp->event_handler(qp->cb_data, NTB_LINK_DOWN);

	dev_info(&pdev->dev, "qp %d: Link Down\n", qp->qp_num);
	qp->qp_link = NTB_LINK_DOWN;

	if (nt->transport_link == NTB_LINK_UP)
		schedule_delayed_work(&qp->link_work,
				      msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
}

578 579 580 581 582 583
static void ntb_qp_link_down(struct ntb_transport_qp *qp)
{
	schedule_work(&qp->link_cleanup);
}

static void ntb_transport_link_cleanup(struct work_struct *work)
584
{
585 586
	struct ntb_transport *nt = container_of(work, struct ntb_transport,
						link_cleanup);
587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615
	int i;

	if (nt->transport_link == NTB_LINK_DOWN)
		cancel_delayed_work_sync(&nt->link_work);
	else
		nt->transport_link = NTB_LINK_DOWN;

	/* Pass along the info to any clients */
	for (i = 0; i < nt->max_qps; i++)
		if (!test_bit(i, &nt->qp_bitmap))
			ntb_qp_link_down(&nt->qps[i]);

	/* The scratchpad registers keep the values if the remote side
	 * goes down, blast them now to give them a sane value the next
	 * time they are accessed
	 */
	for (i = 0; i < MAX_SPAD; i++)
		ntb_write_local_spad(nt->ndev, i, 0);
}

static void ntb_transport_event_callback(void *data, enum ntb_hw_event event)
{
	struct ntb_transport *nt = data;

	switch (event) {
	case NTB_EVENT_HW_LINK_UP:
		schedule_delayed_work(&nt->link_work, 0);
		break;
	case NTB_EVENT_HW_LINK_DOWN:
616
		schedule_work(&nt->link_cleanup);
617 618 619 620 621 622 623 624 625 626 627 628 629 630 631
		break;
	default:
		BUG();
	}
}

static void ntb_transport_link_work(struct work_struct *work)
{
	struct ntb_transport *nt = container_of(work, struct ntb_transport,
						link_work.work);
	struct ntb_device *ndev = nt->ndev;
	struct pci_dev *pdev = ntb_query_pdev(ndev);
	u32 val;
	int rc, i;

Jon Mason's avatar
Jon Mason committed
632 633 634 635 636 637 638 639 640 641
	/* send the local info, in the opposite order of the way we read it */
	for (i = 0; i < NTB_NUM_MW; i++) {
		rc = ntb_write_remote_spad(ndev, MW0_SZ_HIGH + (i * 2),
					   ntb_get_mw_size(ndev, i) >> 32);
		if (rc) {
			dev_err(&pdev->dev, "Error writing %u to remote spad %d\n",
				(u32)(ntb_get_mw_size(ndev, i) >> 32),
				MW0_SZ_HIGH + (i * 2));
			goto out;
		}
642

Jon Mason's avatar
Jon Mason committed
643 644 645 646 647 648 649 650
		rc = ntb_write_remote_spad(ndev, MW0_SZ_LOW + (i * 2),
					   (u32) ntb_get_mw_size(ndev, i));
		if (rc) {
			dev_err(&pdev->dev, "Error writing %u to remote spad %d\n",
				(u32) ntb_get_mw_size(ndev, i),
				MW0_SZ_LOW + (i * 2));
			goto out;
		}
651 652
	}

Jon Mason's avatar
Jon Mason committed
653
	rc = ntb_write_remote_spad(ndev, NUM_MWS, NTB_NUM_MW);
654 655
	if (rc) {
		dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
Jon Mason's avatar
Jon Mason committed
656
			NTB_NUM_MW, NUM_MWS);
657 658 659 660 661 662 663 664 665 666
		goto out;
	}

	rc = ntb_write_remote_spad(ndev, NUM_QPS, nt->max_qps);
	if (rc) {
		dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
			nt->max_qps, NUM_QPS);
		goto out;
	}

Jon Mason's avatar
Jon Mason committed
667
	rc = ntb_write_remote_spad(ndev, VERSION, NTB_TRANSPORT_VERSION);
668 669
	if (rc) {
		dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
Jon Mason's avatar
Jon Mason committed
670
			NTB_TRANSPORT_VERSION, VERSION);
671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694
		goto out;
	}

	/* Query the remote side for its info */
	rc = ntb_read_remote_spad(ndev, VERSION, &val);
	if (rc) {
		dev_err(&pdev->dev, "Error reading remote spad %d\n", VERSION);
		goto out;
	}

	if (val != NTB_TRANSPORT_VERSION)
		goto out;
	dev_dbg(&pdev->dev, "Remote version = %d\n", val);

	rc = ntb_read_remote_spad(ndev, NUM_QPS, &val);
	if (rc) {
		dev_err(&pdev->dev, "Error reading remote spad %d\n", NUM_QPS);
		goto out;
	}

	if (val != nt->max_qps)
		goto out;
	dev_dbg(&pdev->dev, "Remote max number of qps = %d\n", val);

Jon Mason's avatar
Jon Mason committed
695
	rc = ntb_read_remote_spad(ndev, NUM_MWS, &val);
696
	if (rc) {
Jon Mason's avatar
Jon Mason committed
697
		dev_err(&pdev->dev, "Error reading remote spad %d\n", NUM_MWS);
698 699 700
		goto out;
	}

Jon Mason's avatar
Jon Mason committed
701
	if (val != NTB_NUM_MW)
702
		goto out;
Jon Mason's avatar
Jon Mason committed
703
	dev_dbg(&pdev->dev, "Remote number of mws = %d\n", val);
704

Jon Mason's avatar
Jon Mason committed
705 706
	for (i = 0; i < NTB_NUM_MW; i++) {
		u64 val64;
707

Jon Mason's avatar
Jon Mason committed
708 709 710 711 712 713
		rc = ntb_read_remote_spad(ndev, MW0_SZ_HIGH + (i * 2), &val);
		if (rc) {
			dev_err(&pdev->dev, "Error reading remote spad %d\n",
				MW0_SZ_HIGH + (i * 2));
			goto out1;
		}
714

Jon Mason's avatar
Jon Mason committed
715
		val64 = (u64) val << 32;
716

Jon Mason's avatar
Jon Mason committed
717 718 719 720 721 722 723 724 725 726 727 728 729 730 731
		rc = ntb_read_remote_spad(ndev, MW0_SZ_LOW + (i * 2), &val);
		if (rc) {
			dev_err(&pdev->dev, "Error reading remote spad %d\n",
				MW0_SZ_LOW + (i * 2));
			goto out1;
		}

		val64 |= val;

		dev_dbg(&pdev->dev, "Remote MW%d size = %llu\n", i, val64);

		rc = ntb_set_mw(nt, i, val64);
		if (rc)
			goto out1;
	}
732 733 734 735 736 737 738 739 740 741 742 743 744 745

	nt->transport_link = NTB_LINK_UP;

	for (i = 0; i < nt->max_qps; i++) {
		struct ntb_transport_qp *qp = &nt->qps[i];

		ntb_transport_setup_qp_mw(nt, i);

		if (qp->client_ready == NTB_LINK_UP)
			schedule_delayed_work(&qp->link_work, 0);
	}

	return;

Jon Mason's avatar
Jon Mason committed
746 747 748
out1:
	for (i = 0; i < NTB_NUM_MW; i++)
		ntb_free_mw(nt, i);
749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799
out:
	if (ntb_hw_link_status(ndev))
		schedule_delayed_work(&nt->link_work,
				      msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
}

static void ntb_qp_link_work(struct work_struct *work)
{
	struct ntb_transport_qp *qp = container_of(work,
						   struct ntb_transport_qp,
						   link_work.work);
	struct pci_dev *pdev = ntb_query_pdev(qp->ndev);
	struct ntb_transport *nt = qp->transport;
	int rc, val;

	WARN_ON(nt->transport_link != NTB_LINK_UP);

	rc = ntb_read_local_spad(nt->ndev, QP_LINKS, &val);
	if (rc) {
		dev_err(&pdev->dev, "Error reading spad %d\n", QP_LINKS);
		return;
	}

	rc = ntb_write_remote_spad(nt->ndev, QP_LINKS, val | 1 << qp->qp_num);
	if (rc)
		dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
			val | 1 << qp->qp_num, QP_LINKS);

	/* query remote spad for qp ready bits */
	rc = ntb_read_remote_spad(nt->ndev, QP_LINKS, &val);
	if (rc)
		dev_err(&pdev->dev, "Error reading remote spad %d\n", QP_LINKS);

	dev_dbg(&pdev->dev, "Remote QP link status = %x\n", val);

	/* See if the remote side is up */
	if (1 << qp->qp_num & val) {
		qp->qp_link = NTB_LINK_UP;

		dev_info(&pdev->dev, "qp %d: Link Up\n", qp->qp_num);
		if (qp->event_handler)
			qp->event_handler(qp->cb_data, NTB_LINK_UP);
	} else if (nt->transport_link == NTB_LINK_UP)
		schedule_delayed_work(&qp->link_work,
				      msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
}

static void ntb_transport_init_queue(struct ntb_transport *nt,
				     unsigned int qp_num)
{
	struct ntb_transport_qp *qp;
800 801
	unsigned int num_qps_mw, tx_size;
	u8 mw_num = QP_TO_MW(qp_num);
802 803 804 805 806 807 808 809 810

	qp = &nt->qps[qp_num];
	qp->qp_num = qp_num;
	qp->transport = nt;
	qp->ndev = nt->ndev;
	qp->qp_link = NTB_LINK_DOWN;
	qp->client_ready = NTB_LINK_DOWN;
	qp->event_handler = NULL;

811 812 813 814 815
	if (nt->max_qps % NTB_NUM_MW && mw_num < nt->max_qps % NTB_NUM_MW)
		num_qps_mw = nt->max_qps / NTB_NUM_MW + 1;
	else
		num_qps_mw = nt->max_qps / NTB_NUM_MW;

Jon Mason's avatar
Jon Mason committed
816 817 818 819 820
	tx_size = (unsigned int) ntb_get_mw_size(qp->ndev, mw_num) / num_qps_mw;
	qp->rx_info = ntb_get_mw_vbase(nt->ndev, mw_num) +
		      (qp_num / NTB_NUM_MW * tx_size);
	tx_size -= sizeof(struct ntb_rx_info);

Dan Carpenter's avatar
Dan Carpenter committed
821
	qp->tx_mw = qp->rx_info + 1;
822 823
	/* Due to housekeeping, there must be atleast 2 buffs */
	qp->tx_max_frame = min(transport_mtu, tx_size / 2);
Jon Mason's avatar
Jon Mason committed
824
	qp->tx_max_entry = tx_size / qp->tx_max_frame;
825

826
	if (ntb_query_debugfs(nt->ndev)) {
827 828 829 830
		char debugfs_name[4];

		snprintf(debugfs_name, 4, "qp%d", qp_num);
		qp->debugfs_dir = debugfs_create_dir(debugfs_name,
831
						 ntb_query_debugfs(nt->ndev));
832 833 834 835 836 837 838

		qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR,
							qp->debugfs_dir, qp,
							&ntb_qp_debugfs_stats);
	}

	INIT_DELAYED_WORK(&qp->link_work, ntb_qp_link_work);
839
	INIT_WORK(&qp->link_cleanup, ntb_qp_link_cleanup);
840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879

	spin_lock_init(&qp->ntb_rx_pend_q_lock);
	spin_lock_init(&qp->ntb_rx_free_q_lock);
	spin_lock_init(&qp->ntb_tx_free_q_lock);

	INIT_LIST_HEAD(&qp->rx_pend_q);
	INIT_LIST_HEAD(&qp->rx_free_q);
	INIT_LIST_HEAD(&qp->tx_free_q);
}

int ntb_transport_init(struct pci_dev *pdev)
{
	struct ntb_transport *nt;
	int rc, i;

	nt = kzalloc(sizeof(struct ntb_transport), GFP_KERNEL);
	if (!nt)
		return -ENOMEM;

	nt->ndev = ntb_register_transport(pdev, nt);
	if (!nt->ndev) {
		rc = -EIO;
		goto err;
	}

	nt->max_qps = min(nt->ndev->max_cbs, max_num_clients);

	nt->qps = kcalloc(nt->max_qps, sizeof(struct ntb_transport_qp),
			  GFP_KERNEL);
	if (!nt->qps) {
		rc = -ENOMEM;
		goto err1;
	}

	nt->qp_bitmap = ((u64) 1 << nt->max_qps) - 1;

	for (i = 0; i < nt->max_qps; i++)
		ntb_transport_init_queue(nt, i);

	INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work);
880
	INIT_WORK(&nt->link_cleanup, ntb_transport_link_cleanup);
881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916

	rc = ntb_register_event_callback(nt->ndev,
					 ntb_transport_event_callback);
	if (rc)
		goto err2;

	INIT_LIST_HEAD(&nt->client_devs);
	rc = ntb_bus_init(nt);
	if (rc)
		goto err3;

	if (ntb_hw_link_status(nt->ndev))
		schedule_delayed_work(&nt->link_work, 0);

	return 0;

err3:
	ntb_unregister_event_callback(nt->ndev);
err2:
	kfree(nt->qps);
err1:
	ntb_unregister_transport(nt->ndev);
err:
	kfree(nt);
	return rc;
}

void ntb_transport_free(void *transport)
{
	struct ntb_transport *nt = transport;
	struct pci_dev *pdev;
	int i;

	nt->transport_link = NTB_LINK_DOWN;

	/* verify that all the qp's are freed */
917
	for (i = 0; i < nt->max_qps; i++) {
918 919
		if (!test_bit(i, &nt->qp_bitmap))
			ntb_transport_free_queue(&nt->qps[i]);
920 921
		debugfs_remove_recursive(nt->qps[i].debugfs_dir);
	}
922 923 924 925 926 927 928 929 930 931

	ntb_bus_remove(nt);

	cancel_delayed_work_sync(&nt->link_work);

	ntb_unregister_event_callback(nt->ndev);

	pdev = ntb_query_pdev(nt->ndev);

	for (i = 0; i < NTB_NUM_MW; i++)
Jon Mason's avatar
Jon Mason committed
932
		ntb_free_mw(nt, i);
933 934 935 936 937 938 939 940 941

	kfree(nt->qps);
	ntb_unregister_transport(nt->ndev);
	kfree(nt);
}

static void ntb_rx_copy_task(struct ntb_transport_qp *qp,
			     struct ntb_queue_entry *entry, void *offset)
{
942 943
	void *cb_data = entry->cb_data;
	unsigned int len = entry->len;
944

945
	memcpy(entry->buf, offset, entry->len);
946 947

	ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry, &qp->rx_free_q);
948 949 950

	if (qp->rx_handler && qp->client_ready == NTB_LINK_UP)
		qp->rx_handler(qp, qp->cb_data, cb_data, len);
951 952 953 954 955 956 957 958
}

static int ntb_process_rxc(struct ntb_transport_qp *qp)
{
	struct ntb_payload_header *hdr;
	struct ntb_queue_entry *entry;
	void *offset;

Jon Mason's avatar
Jon Mason committed
959 960 961
	offset = qp->rx_buff + qp->rx_max_frame * qp->rx_index;
	hdr = offset + qp->rx_max_frame - sizeof(struct ntb_payload_header);

962 963 964
	entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q);
	if (!entry) {
		dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
Jon Mason's avatar
Jon Mason committed
965
			"no buffer - HDR ver %u, len %d, flags %x\n",
966 967 968 969 970 971 972
			hdr->ver, hdr->len, hdr->flags);
		qp->rx_err_no_buf++;
		return -ENOMEM;
	}

	if (!(hdr->flags & DESC_DONE_FLAG)) {
		ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
Jon Mason's avatar
Jon Mason committed
973
			     &qp->rx_pend_q);
974 975 976 977
		qp->rx_ring_empty++;
		return -EAGAIN;
	}

Jon Mason's avatar
Jon Mason committed
978
	if (hdr->ver != (u32) qp->rx_pkts) {
979
		dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
Jon Mason's avatar
Jon Mason committed
980
			"qp %d: version mismatch, expected %llu - got %u\n",
981 982
			qp->qp_num, qp->rx_pkts, hdr->ver);
		ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
Jon Mason's avatar
Jon Mason committed
983
			     &qp->rx_pend_q);
984 985 986 987 988 989 990 991
		qp->rx_err_ver++;
		return -EIO;
	}

	if (hdr->flags & LINK_DOWN_FLAG) {
		ntb_qp_link_down(qp);

		ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
Jon Mason's avatar
Jon Mason committed
992
			     &qp->rx_pend_q);
993 994 995 996
		goto out;
	}

	dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
Jon Mason's avatar
Jon Mason committed
997
		"rx offset %u, ver %u - %d payload received, buf size %d\n",
Jon Mason's avatar
Jon Mason committed
998
		qp->rx_index, hdr->ver, hdr->len, entry->len);
999

Jon Mason's avatar
Jon Mason committed
1000 1001
	if (hdr->len <= entry->len) {
		entry->len = hdr->len;
1002
		ntb_rx_copy_task(qp, entry, offset);
Jon Mason's avatar
Jon Mason committed
1003
	} else {
1004
		ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
Jon Mason's avatar
Jon Mason committed
1005
			     &qp->rx_pend_q);
1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016

		qp->rx_err_oflow++;
		dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
			"RX overflow! Wanted %d got %d\n",
			hdr->len, entry->len);
	}

	qp->rx_bytes += hdr->len;
	qp->rx_pkts++;

out:
Jon Mason's avatar
Jon Mason committed
1017 1018 1019
	/* Ensure that the data is fully copied out before clearing the flag */
	wmb();
	hdr->flags = 0;
Jon Mason's avatar
Jon Mason committed
1020
	iowrite32(qp->rx_index, &qp->rx_info->entry);
Jon Mason's avatar
Jon Mason committed
1021 1022 1023

	qp->rx_index++;
	qp->rx_index %= qp->rx_max_entry;
1024 1025 1026 1027 1028 1029 1030

	return 0;
}

static void ntb_transport_rx(unsigned long data)
{
	struct ntb_transport_qp *qp = (struct ntb_transport_qp *)data;
Jon Mason's avatar
Jon Mason committed
1031
	int rc, i;
1032

Jon Mason's avatar
Jon Mason committed
1033 1034 1035 1036
	/* Limit the number of packets processed in a single interrupt to
	 * provide fairness to others
	 */
	for (i = 0; i < qp->rx_max_entry; i++) {
1037
		rc = ntb_process_rxc(qp);
Jon Mason's avatar
Jon Mason committed
1038 1039 1040
		if (rc)
			break;
	}
1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054
}

static void ntb_transport_rxc_db(void *data, int db_num)
{
	struct ntb_transport_qp *qp = data;

	dev_dbg(&ntb_query_pdev(qp->ndev)->dev, "%s: doorbell %d received\n",
		__func__, db_num);

	tasklet_schedule(&qp->rx_work);
}

static void ntb_tx_copy_task(struct ntb_transport_qp *qp,
			     struct ntb_queue_entry *entry,
Jon Mason's avatar
Jon Mason committed
1055
			     void __iomem *offset)
1056
{
Jon Mason's avatar
Jon Mason committed
1057
	struct ntb_payload_header __iomem *hdr;
1058 1059 1060

	memcpy_toio(offset, entry->buf, entry->len);

1061
	hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
Jon Mason's avatar
Jon Mason committed
1062 1063
	iowrite32(entry->len, &hdr->len);
	iowrite32((u32) qp->tx_pkts, &hdr->ver);
1064 1065

	/* Ensure that the data is fully copied out before setting the flag */
Jon Mason's avatar
Jon Mason committed
1066
	wmb();
Jon Mason's avatar
Jon Mason committed
1067
	iowrite32(entry->flags | DESC_DONE_FLAG, &hdr->flags);
1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088

	ntb_ring_sdb(qp->ndev, qp->qp_num);

	/* The entry length can only be zero if the packet is intended to be a
	 * "link down" or similar.  Since no payload is being sent in these
	 * cases, there is nothing to add to the completion queue.
	 */
	if (entry->len > 0) {
		qp->tx_bytes += entry->len;

		if (qp->tx_handler)
			qp->tx_handler(qp, qp->cb_data, entry->cb_data,
				       entry->len);
	}

	ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q);
}

static int ntb_process_tx(struct ntb_transport_qp *qp,
			  struct ntb_queue_entry *entry)
{
Jon Mason's avatar
Jon Mason committed
1089
	void __iomem *offset;
1090

Jon Mason's avatar
Jon Mason committed
1091
	offset = qp->tx_mw + qp->tx_max_frame * qp->tx_index;
1092

Jon Mason's avatar
Jon Mason committed
1093 1094
	dev_dbg(&ntb_query_pdev(qp->ndev)->dev, "%lld - offset %p, tx %u, entry len %d flags %x buff %p\n",
		qp->tx_pkts, offset, qp->tx_index, entry->len, entry->flags,
Jon Mason's avatar
Jon Mason committed
1095
		entry->buf);
Jon Mason's avatar
Jon Mason committed
1096
	if (qp->tx_index == qp->remote_rx_info->entry) {
1097 1098 1099 1100
		qp->tx_ring_full++;
		return -EAGAIN;
	}

1101
	if (entry->len > qp->tx_max_frame - sizeof(struct ntb_payload_header)) {
1102 1103 1104 1105 1106 1107 1108 1109 1110 1111
		if (qp->tx_handler)
			qp->tx_handler(qp->cb_data, qp, NULL, -EIO);

		ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
			     &qp->tx_free_q);
		return 0;
	}

	ntb_tx_copy_task(qp, entry, offset);

Jon Mason's avatar
Jon Mason committed
1112 1113
	qp->tx_index++;
	qp->tx_index %= qp->tx_max_entry;
1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132

	qp->tx_pkts++;

	return 0;
}

static void ntb_send_link_down(struct ntb_transport_qp *qp)
{
	struct pci_dev *pdev = ntb_query_pdev(qp->ndev);
	struct ntb_queue_entry *entry;
	int i, rc;

	if (qp->qp_link == NTB_LINK_DOWN)
		return;

	qp->qp_link = NTB_LINK_DOWN;
	dev_info(&pdev->dev, "qp %d: Link Down\n", qp->qp_num);

	for (i = 0; i < NTB_LINK_DOWN_TIMEOUT; i++) {
Jon Mason's avatar
Jon Mason committed
1133
		entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201
		if (entry)
			break;
		msleep(100);
	}

	if (!entry)
		return;

	entry->cb_data = NULL;
	entry->buf = NULL;
	entry->len = 0;
	entry->flags = LINK_DOWN_FLAG;

	rc = ntb_process_tx(qp, entry);
	if (rc)
		dev_err(&pdev->dev, "ntb: QP%d unable to send linkdown msg\n",
			qp->qp_num);
}

/**
 * ntb_transport_create_queue - Create a new NTB transport layer queue
 * @rx_handler: receive callback function
 * @tx_handler: transmit callback function
 * @event_handler: event callback function
 *
 * Create a new NTB transport layer queue and provide the queue with a callback
 * routine for both transmit and receive.  The receive callback routine will be
 * used to pass up data when the transport has received it on the queue.   The
 * transmit callback routine will be called when the transport has completed the
 * transmission of the data on the queue and the data is ready to be freed.
 *
 * RETURNS: pointer to newly created ntb_queue, NULL on error.
 */
struct ntb_transport_qp *
ntb_transport_create_queue(void *data, struct pci_dev *pdev,
			   const struct ntb_queue_handlers *handlers)
{
	struct ntb_queue_entry *entry;
	struct ntb_transport_qp *qp;
	struct ntb_transport *nt;
	unsigned int free_queue;
	int rc, i;

	nt = ntb_find_transport(pdev);
	if (!nt)
		goto err;

	free_queue = ffs(nt->qp_bitmap);
	if (!free_queue)
		goto err;

	/* decrement free_queue to make it zero based */
	free_queue--;

	clear_bit(free_queue, &nt->qp_bitmap);

	qp = &nt->qps[free_queue];
	qp->cb_data = data;
	qp->rx_handler = handlers->rx_handler;
	qp->tx_handler = handlers->tx_handler;
	qp->event_handler = handlers->event_handler;

	for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
		entry = kzalloc(sizeof(struct ntb_queue_entry), GFP_ATOMIC);
		if (!entry)
			goto err1;

		ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry,
Jon Mason's avatar
Jon Mason committed
1202
			     &qp->rx_free_q);
1203 1204 1205 1206 1207 1208 1209 1210
	}

	for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
		entry = kzalloc(sizeof(struct ntb_queue_entry), GFP_ATOMIC);
		if (!entry)
			goto err2;

		ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
Jon Mason's avatar
Jon Mason committed
1211
			     &qp->tx_free_q);
1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227
	}

	tasklet_init(&qp->rx_work, ntb_transport_rx, (unsigned long) qp);

	rc = ntb_register_db_callback(qp->ndev, free_queue, qp,
				      ntb_transport_rxc_db);
	if (rc)
		goto err3;

	dev_info(&pdev->dev, "NTB Transport QP %d created\n", qp->qp_num);

	return qp;

err3:
	tasklet_disable(&qp->rx_work);
err2:
Jon Mason's avatar
Jon Mason committed
1228
	while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1229 1230
		kfree(entry);
err1:
Jon Mason's avatar
Jon Mason committed
1231
	while ((entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q)))
1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246
		kfree(entry);
	set_bit(free_queue, &nt->qp_bitmap);
err:
	return NULL;
}
EXPORT_SYMBOL_GPL(ntb_transport_create_queue);

/**
 * ntb_transport_free_queue - Frees NTB transport queue
 * @qp: NTB queue to be freed
 *
 * Frees NTB transport queue
 */
void ntb_transport_free_queue(struct ntb_transport_qp *qp)
{
1247
	struct pci_dev *pdev;
1248 1249 1250 1251 1252
	struct ntb_queue_entry *entry;

	if (!qp)
		return;

1253 1254
	pdev = ntb_query_pdev(qp->ndev);

1255 1256 1257 1258 1259
	cancel_delayed_work_sync(&qp->link_work);

	ntb_unregister_db_callback(qp->ndev, qp->qp_num);
	tasklet_disable(&qp->rx_work);

Jon Mason's avatar
Jon Mason committed
1260
	while ((entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q)))
1261 1262
		kfree(entry);

Jon Mason's avatar
Jon Mason committed
1263
	while ((entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q))) {
1264 1265 1266 1267
		dev_warn(&pdev->dev, "Freeing item from a non-empty queue\n");
		kfree(entry);
	}

Jon Mason's avatar
Jon Mason committed
1268
	while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301
		kfree(entry);

	set_bit(qp->qp_num, &qp->transport->qp_bitmap);

	dev_info(&pdev->dev, "NTB Transport QP %d freed\n", qp->qp_num);
}
EXPORT_SYMBOL_GPL(ntb_transport_free_queue);

/**
 * ntb_transport_rx_remove - Dequeues enqueued rx packet
 * @qp: NTB queue to be freed
 * @len: pointer to variable to write enqueued buffers length
 *
 * Dequeues unused buffers from receive queue.  Should only be used during
 * shutdown of qp.
 *
 * RETURNS: NULL error value on error, or void* for success.
 */
void *ntb_transport_rx_remove(struct ntb_transport_qp *qp, unsigned int *len)
{
	struct ntb_queue_entry *entry;
	void *buf;

	if (!qp || qp->client_ready == NTB_LINK_UP)
		return NULL;

	entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q);
	if (!entry)
		return NULL;

	buf = entry->cb_data;
	*len = entry->len;

Jon Mason's avatar
Jon Mason committed
1302
	ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry, &qp->rx_free_q);
1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335

	return buf;
}
EXPORT_SYMBOL_GPL(ntb_transport_rx_remove);

/**
 * ntb_transport_rx_enqueue - Enqueue a new NTB queue entry
 * @qp: NTB transport layer queue the entry is to be enqueued on
 * @cb: per buffer pointer for callback function to use
 * @data: pointer to data buffer that incoming packets will be copied into
 * @len: length of the data buffer
 *
 * Enqueue a new receive buffer onto the transport queue into which a NTB
 * payload can be received into.
 *
 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 */
int ntb_transport_rx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
			     unsigned int len)
{
	struct ntb_queue_entry *entry;

	if (!qp)
		return -EINVAL;

	entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q);
	if (!entry)
		return -ENOMEM;

	entry->cb_data = cb;
	entry->buf = data;
	entry->len = len;

Jon Mason's avatar
Jon Mason committed
1336
	ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry, &qp->rx_pend_q);
1337 1338 1339 1340 1341 1342 1343 1344 1345 1346