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[deliverable/linux.git] / drivers / ntb / ntb_transport.c
1 /*
2 * This file is provided under a dual BSD/GPLv2 license. When using or
3 * redistributing this file, you may do so under either license.
4 *
5 * GPL LICENSE SUMMARY
6 *
7 * Copyright(c) 2012 Intel Corporation. All rights reserved.
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of version 2 of the GNU General Public License as
11 * published by the Free Software Foundation.
12 *
13 * BSD LICENSE
14 *
15 * Copyright(c) 2012 Intel Corporation. All rights reserved.
16 *
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions
19 * are met:
20 *
21 * * Redistributions of source code must retain the above copyright
22 * notice, this list of conditions and the following disclaimer.
23 * * Redistributions in binary form must reproduce the above copy
24 * notice, this list of conditions and the following disclaimer in
25 * the documentation and/or other materials provided with the
26 * distribution.
27 * * Neither the name of Intel Corporation nor the names of its
28 * contributors may be used to endorse or promote products derived
29 * from this software without specific prior written permission.
30 *
31 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
34 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
36 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
37 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
38 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
39 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
40 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
41 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
42 *
43 * Intel PCIe NTB Linux driver
44 *
45 * Contact Information:
46 * Jon Mason <jon.mason@intel.com>
47 */
48 #include <linux/debugfs.h>
49 #include <linux/delay.h>
50 #include <linux/dmaengine.h>
51 #include <linux/dma-mapping.h>
52 #include <linux/errno.h>
53 #include <linux/export.h>
54 #include <linux/interrupt.h>
55 #include <linux/module.h>
56 #include <linux/pci.h>
57 #include <linux/slab.h>
58 #include <linux/types.h>
59 #include <linux/ntb.h>
60 #include "ntb_hw.h"
61
62 #define NTB_TRANSPORT_VERSION 3
63
64 static unsigned int transport_mtu = 0x401E;
65 module_param(transport_mtu, uint, 0644);
66 MODULE_PARM_DESC(transport_mtu, "Maximum size of NTB transport packets");
67
68 static unsigned char max_num_clients;
69 module_param(max_num_clients, byte, 0644);
70 MODULE_PARM_DESC(max_num_clients, "Maximum number of NTB transport clients");
71
72 static unsigned int copy_bytes = 1024;
73 module_param(copy_bytes, uint, 0644);
74 MODULE_PARM_DESC(copy_bytes, "Threshold under which NTB will use the CPU to copy instead of DMA");
75
76 struct ntb_queue_entry {
77 /* ntb_queue list reference */
78 struct list_head entry;
79 /* pointers to data to be transfered */
80 void *cb_data;
81 void *buf;
82 unsigned int len;
83 unsigned int flags;
84
85 struct ntb_transport_qp *qp;
86 union {
87 struct ntb_payload_header __iomem *tx_hdr;
88 struct ntb_payload_header *rx_hdr;
89 };
90 unsigned int index;
91 };
92
93 struct ntb_rx_info {
94 unsigned int entry;
95 };
96
97 struct ntb_transport_qp {
98 struct ntb_transport *transport;
99 struct ntb_device *ndev;
100 void *cb_data;
101 struct dma_chan *dma_chan;
102
103 bool client_ready;
104 bool qp_link;
105 u8 qp_num; /* Only 64 QP's are allowed. 0-63 */
106
107 struct ntb_rx_info __iomem *rx_info;
108 struct ntb_rx_info *remote_rx_info;
109
110 void (*tx_handler) (struct ntb_transport_qp *qp, void *qp_data,
111 void *data, int len);
112 struct list_head tx_free_q;
113 spinlock_t ntb_tx_free_q_lock;
114 void __iomem *tx_mw;
115 dma_addr_t tx_mw_phys;
116 unsigned int tx_index;
117 unsigned int tx_max_entry;
118 unsigned int tx_max_frame;
119
120 void (*rx_handler) (struct ntb_transport_qp *qp, void *qp_data,
121 void *data, int len);
122 struct tasklet_struct rx_work;
123 struct list_head rx_pend_q;
124 struct list_head rx_free_q;
125 spinlock_t ntb_rx_pend_q_lock;
126 spinlock_t ntb_rx_free_q_lock;
127 void *rx_buff;
128 unsigned int rx_index;
129 unsigned int rx_max_entry;
130 unsigned int rx_max_frame;
131 dma_cookie_t last_cookie;
132
133 void (*event_handler) (void *data, int status);
134 struct delayed_work link_work;
135 struct work_struct link_cleanup;
136
137 struct dentry *debugfs_dir;
138 struct dentry *debugfs_stats;
139
140 /* Stats */
141 u64 rx_bytes;
142 u64 rx_pkts;
143 u64 rx_ring_empty;
144 u64 rx_err_no_buf;
145 u64 rx_err_oflow;
146 u64 rx_err_ver;
147 u64 rx_memcpy;
148 u64 rx_async;
149 u64 tx_bytes;
150 u64 tx_pkts;
151 u64 tx_ring_full;
152 u64 tx_err_no_buf;
153 u64 tx_memcpy;
154 u64 tx_async;
155 };
156
157 struct ntb_transport_mw {
158 size_t size;
159 void *virt_addr;
160 dma_addr_t dma_addr;
161 };
162
163 struct ntb_transport_client_dev {
164 struct list_head entry;
165 struct device dev;
166 };
167
168 struct ntb_transport {
169 struct list_head entry;
170 struct list_head client_devs;
171
172 struct ntb_device *ndev;
173 struct ntb_transport_mw *mw;
174 struct ntb_transport_qp *qps;
175 unsigned int max_qps;
176 unsigned long qp_bitmap;
177 bool transport_link;
178 struct delayed_work link_work;
179 struct work_struct link_cleanup;
180 };
181
182 enum {
183 DESC_DONE_FLAG = 1 << 0,
184 LINK_DOWN_FLAG = 1 << 1,
185 };
186
187 struct ntb_payload_header {
188 unsigned int ver;
189 unsigned int len;
190 unsigned int flags;
191 };
192
193 enum {
194 VERSION = 0,
195 QP_LINKS,
196 NUM_QPS,
197 NUM_MWS,
198 MW0_SZ_HIGH,
199 MW0_SZ_LOW,
200 MW1_SZ_HIGH,
201 MW1_SZ_LOW,
202 MAX_SPAD,
203 };
204
205 #define QP_TO_MW(ndev, qp) ((qp) % ntb_max_mw(ndev))
206 #define NTB_QP_DEF_NUM_ENTRIES 100
207 #define NTB_LINK_DOWN_TIMEOUT 10
208
209 static int ntb_match_bus(struct device *dev, struct device_driver *drv)
210 {
211 return !strncmp(dev_name(dev), drv->name, strlen(drv->name));
212 }
213
214 static int ntb_client_probe(struct device *dev)
215 {
216 const struct ntb_client *drv = container_of(dev->driver,
217 struct ntb_client, driver);
218 struct pci_dev *pdev = container_of(dev->parent, struct pci_dev, dev);
219 int rc = -EINVAL;
220
221 get_device(dev);
222 if (drv && drv->probe)
223 rc = drv->probe(pdev);
224 if (rc)
225 put_device(dev);
226
227 return rc;
228 }
229
230 static int ntb_client_remove(struct device *dev)
231 {
232 const struct ntb_client *drv = container_of(dev->driver,
233 struct ntb_client, driver);
234 struct pci_dev *pdev = container_of(dev->parent, struct pci_dev, dev);
235
236 if (drv && drv->remove)
237 drv->remove(pdev);
238
239 put_device(dev);
240
241 return 0;
242 }
243
244 static struct bus_type ntb_bus_type = {
245 .name = "ntb_bus",
246 .match = ntb_match_bus,
247 .probe = ntb_client_probe,
248 .remove = ntb_client_remove,
249 };
250
251 static LIST_HEAD(ntb_transport_list);
252
253 static int ntb_bus_init(struct ntb_transport *nt)
254 {
255 if (list_empty(&ntb_transport_list)) {
256 int rc = bus_register(&ntb_bus_type);
257 if (rc)
258 return rc;
259 }
260
261 list_add(&nt->entry, &ntb_transport_list);
262
263 return 0;
264 }
265
266 static void ntb_bus_remove(struct ntb_transport *nt)
267 {
268 struct ntb_transport_client_dev *client_dev, *cd;
269
270 list_for_each_entry_safe(client_dev, cd, &nt->client_devs, entry) {
271 dev_err(client_dev->dev.parent, "%s still attached to bus, removing\n",
272 dev_name(&client_dev->dev));
273 list_del(&client_dev->entry);
274 device_unregister(&client_dev->dev);
275 }
276
277 list_del(&nt->entry);
278
279 if (list_empty(&ntb_transport_list))
280 bus_unregister(&ntb_bus_type);
281 }
282
283 static void ntb_client_release(struct device *dev)
284 {
285 struct ntb_transport_client_dev *client_dev;
286 client_dev = container_of(dev, struct ntb_transport_client_dev, dev);
287
288 kfree(client_dev);
289 }
290
291 /**
292 * ntb_unregister_client_dev - Unregister NTB client device
293 * @device_name: Name of NTB client device
294 *
295 * Unregister an NTB client device with the NTB transport layer
296 */
297 void ntb_unregister_client_dev(char *device_name)
298 {
299 struct ntb_transport_client_dev *client, *cd;
300 struct ntb_transport *nt;
301
302 list_for_each_entry(nt, &ntb_transport_list, entry)
303 list_for_each_entry_safe(client, cd, &nt->client_devs, entry)
304 if (!strncmp(dev_name(&client->dev), device_name,
305 strlen(device_name))) {
306 list_del(&client->entry);
307 device_unregister(&client->dev);
308 }
309 }
310 EXPORT_SYMBOL_GPL(ntb_unregister_client_dev);
311
312 /**
313 * ntb_register_client_dev - Register NTB client device
314 * @device_name: Name of NTB client device
315 *
316 * Register an NTB client device with the NTB transport layer
317 */
318 int ntb_register_client_dev(char *device_name)
319 {
320 struct ntb_transport_client_dev *client_dev;
321 struct ntb_transport *nt;
322 int rc, i = 0;
323
324 if (list_empty(&ntb_transport_list))
325 return -ENODEV;
326
327 list_for_each_entry(nt, &ntb_transport_list, entry) {
328 struct device *dev;
329
330 client_dev = kzalloc(sizeof(struct ntb_transport_client_dev),
331 GFP_KERNEL);
332 if (!client_dev) {
333 rc = -ENOMEM;
334 goto err;
335 }
336
337 dev = &client_dev->dev;
338
339 /* setup and register client devices */
340 dev_set_name(dev, "%s%d", device_name, i);
341 dev->bus = &ntb_bus_type;
342 dev->release = ntb_client_release;
343 dev->parent = &ntb_query_pdev(nt->ndev)->dev;
344
345 rc = device_register(dev);
346 if (rc) {
347 kfree(client_dev);
348 goto err;
349 }
350
351 list_add_tail(&client_dev->entry, &nt->client_devs);
352 i++;
353 }
354
355 return 0;
356
357 err:
358 ntb_unregister_client_dev(device_name);
359
360 return rc;
361 }
362 EXPORT_SYMBOL_GPL(ntb_register_client_dev);
363
364 /**
365 * ntb_register_client - Register NTB client driver
366 * @drv: NTB client driver to be registered
367 *
368 * Register an NTB client driver with the NTB transport layer
369 *
370 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
371 */
372 int ntb_register_client(struct ntb_client *drv)
373 {
374 drv->driver.bus = &ntb_bus_type;
375
376 if (list_empty(&ntb_transport_list))
377 return -ENODEV;
378
379 return driver_register(&drv->driver);
380 }
381 EXPORT_SYMBOL_GPL(ntb_register_client);
382
383 /**
384 * ntb_unregister_client - Unregister NTB client driver
385 * @drv: NTB client driver to be unregistered
386 *
387 * Unregister an NTB client driver with the NTB transport layer
388 *
389 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
390 */
391 void ntb_unregister_client(struct ntb_client *drv)
392 {
393 driver_unregister(&drv->driver);
394 }
395 EXPORT_SYMBOL_GPL(ntb_unregister_client);
396
397 static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count,
398 loff_t *offp)
399 {
400 struct ntb_transport_qp *qp;
401 char *buf;
402 ssize_t ret, out_offset, out_count;
403
404 out_count = 1000;
405
406 buf = kmalloc(out_count, GFP_KERNEL);
407 if (!buf)
408 return -ENOMEM;
409
410 qp = filp->private_data;
411 out_offset = 0;
412 out_offset += snprintf(buf + out_offset, out_count - out_offset,
413 "NTB QP stats\n");
414 out_offset += snprintf(buf + out_offset, out_count - out_offset,
415 "rx_bytes - \t%llu\n", qp->rx_bytes);
416 out_offset += snprintf(buf + out_offset, out_count - out_offset,
417 "rx_pkts - \t%llu\n", qp->rx_pkts);
418 out_offset += snprintf(buf + out_offset, out_count - out_offset,
419 "rx_memcpy - \t%llu\n", qp->rx_memcpy);
420 out_offset += snprintf(buf + out_offset, out_count - out_offset,
421 "rx_async - \t%llu\n", qp->rx_async);
422 out_offset += snprintf(buf + out_offset, out_count - out_offset,
423 "rx_ring_empty - %llu\n", qp->rx_ring_empty);
424 out_offset += snprintf(buf + out_offset, out_count - out_offset,
425 "rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
426 out_offset += snprintf(buf + out_offset, out_count - out_offset,
427 "rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
428 out_offset += snprintf(buf + out_offset, out_count - out_offset,
429 "rx_err_ver - \t%llu\n", qp->rx_err_ver);
430 out_offset += snprintf(buf + out_offset, out_count - out_offset,
431 "rx_buff - \t%p\n", qp->rx_buff);
432 out_offset += snprintf(buf + out_offset, out_count - out_offset,
433 "rx_index - \t%u\n", qp->rx_index);
434 out_offset += snprintf(buf + out_offset, out_count - out_offset,
435 "rx_max_entry - \t%u\n", qp->rx_max_entry);
436
437 out_offset += snprintf(buf + out_offset, out_count - out_offset,
438 "tx_bytes - \t%llu\n", qp->tx_bytes);
439 out_offset += snprintf(buf + out_offset, out_count - out_offset,
440 "tx_pkts - \t%llu\n", qp->tx_pkts);
441 out_offset += snprintf(buf + out_offset, out_count - out_offset,
442 "tx_memcpy - \t%llu\n", qp->tx_memcpy);
443 out_offset += snprintf(buf + out_offset, out_count - out_offset,
444 "tx_async - \t%llu\n", qp->tx_async);
445 out_offset += snprintf(buf + out_offset, out_count - out_offset,
446 "tx_ring_full - \t%llu\n", qp->tx_ring_full);
447 out_offset += snprintf(buf + out_offset, out_count - out_offset,
448 "tx_err_no_buf - %llu\n", qp->tx_err_no_buf);
449 out_offset += snprintf(buf + out_offset, out_count - out_offset,
450 "tx_mw - \t%p\n", qp->tx_mw);
451 out_offset += snprintf(buf + out_offset, out_count - out_offset,
452 "tx_index - \t%u\n", qp->tx_index);
453 out_offset += snprintf(buf + out_offset, out_count - out_offset,
454 "tx_max_entry - \t%u\n", qp->tx_max_entry);
455
456 out_offset += snprintf(buf + out_offset, out_count - out_offset,
457 "\nQP Link %s\n", (qp->qp_link == NTB_LINK_UP) ?
458 "Up" : "Down");
459 if (out_offset > out_count)
460 out_offset = out_count;
461
462 ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
463 kfree(buf);
464 return ret;
465 }
466
467 static const struct file_operations ntb_qp_debugfs_stats = {
468 .owner = THIS_MODULE,
469 .open = simple_open,
470 .read = debugfs_read,
471 };
472
473 static void ntb_list_add(spinlock_t *lock, struct list_head *entry,
474 struct list_head *list)
475 {
476 unsigned long flags;
477
478 spin_lock_irqsave(lock, flags);
479 list_add_tail(entry, list);
480 spin_unlock_irqrestore(lock, flags);
481 }
482
483 static struct ntb_queue_entry *ntb_list_rm(spinlock_t *lock,
484 struct list_head *list)
485 {
486 struct ntb_queue_entry *entry;
487 unsigned long flags;
488
489 spin_lock_irqsave(lock, flags);
490 if (list_empty(list)) {
491 entry = NULL;
492 goto out;
493 }
494 entry = list_first_entry(list, struct ntb_queue_entry, entry);
495 list_del(&entry->entry);
496 out:
497 spin_unlock_irqrestore(lock, flags);
498
499 return entry;
500 }
501
502 static void ntb_transport_setup_qp_mw(struct ntb_transport *nt,
503 unsigned int qp_num)
504 {
505 struct ntb_transport_qp *qp = &nt->qps[qp_num];
506 unsigned int rx_size, num_qps_mw;
507 u8 mw_num, mw_max;
508 unsigned int i;
509
510 mw_max = ntb_max_mw(nt->ndev);
511 mw_num = QP_TO_MW(nt->ndev, qp_num);
512
513 WARN_ON(nt->mw[mw_num].virt_addr == NULL);
514
515 if (nt->max_qps % mw_max && mw_num < nt->max_qps % mw_max)
516 num_qps_mw = nt->max_qps / mw_max + 1;
517 else
518 num_qps_mw = nt->max_qps / mw_max;
519
520 rx_size = (unsigned int) nt->mw[mw_num].size / num_qps_mw;
521 qp->rx_buff = nt->mw[mw_num].virt_addr + qp_num / mw_max * rx_size;
522 rx_size -= sizeof(struct ntb_rx_info);
523
524 qp->remote_rx_info = qp->rx_buff + rx_size;
525
526 /* Due to housekeeping, there must be atleast 2 buffs */
527 qp->rx_max_frame = min(transport_mtu, rx_size / 2);
528 qp->rx_max_entry = rx_size / qp->rx_max_frame;
529 qp->rx_index = 0;
530
531 qp->remote_rx_info->entry = qp->rx_max_entry - 1;
532
533 /* setup the hdr offsets with 0's */
534 for (i = 0; i < qp->rx_max_entry; i++) {
535 void *offset = qp->rx_buff + qp->rx_max_frame * (i + 1) -
536 sizeof(struct ntb_payload_header);
537 memset(offset, 0, sizeof(struct ntb_payload_header));
538 }
539
540 qp->rx_pkts = 0;
541 qp->tx_pkts = 0;
542 qp->tx_index = 0;
543 }
544
545 static void ntb_free_mw(struct ntb_transport *nt, int num_mw)
546 {
547 struct ntb_transport_mw *mw = &nt->mw[num_mw];
548 struct pci_dev *pdev = ntb_query_pdev(nt->ndev);
549
550 if (!mw->virt_addr)
551 return;
552
553 dma_free_coherent(&pdev->dev, mw->size, mw->virt_addr, mw->dma_addr);
554 mw->virt_addr = NULL;
555 }
556
557 static int ntb_set_mw(struct ntb_transport *nt, int num_mw, unsigned int size)
558 {
559 struct ntb_transport_mw *mw = &nt->mw[num_mw];
560 struct pci_dev *pdev = ntb_query_pdev(nt->ndev);
561
562 /* No need to re-setup */
563 if (mw->size == ALIGN(size, 4096))
564 return 0;
565
566 if (mw->size != 0)
567 ntb_free_mw(nt, num_mw);
568
569 /* Alloc memory for receiving data. Must be 4k aligned */
570 mw->size = ALIGN(size, 4096);
571
572 mw->virt_addr = dma_alloc_coherent(&pdev->dev, mw->size, &mw->dma_addr,
573 GFP_KERNEL);
574 if (!mw->virt_addr) {
575 mw->size = 0;
576 dev_err(&pdev->dev, "Unable to allocate MW buffer of size %d\n",
577 (int) mw->size);
578 return -ENOMEM;
579 }
580
581 /* Notify HW the memory location of the receive buffer */
582 ntb_set_mw_addr(nt->ndev, num_mw, mw->dma_addr);
583
584 return 0;
585 }
586
587 static void ntb_qp_link_cleanup(struct ntb_transport_qp *qp)
588 {
589 struct ntb_transport *nt = qp->transport;
590 struct pci_dev *pdev = ntb_query_pdev(nt->ndev);
591
592 if (qp->qp_link == NTB_LINK_DOWN) {
593 cancel_delayed_work_sync(&qp->link_work);
594 return;
595 }
596
597 if (qp->event_handler)
598 qp->event_handler(qp->cb_data, NTB_LINK_DOWN);
599
600 dev_info(&pdev->dev, "qp %d: Link Down\n", qp->qp_num);
601 qp->qp_link = NTB_LINK_DOWN;
602 }
603
604 static void ntb_qp_link_cleanup_work(struct work_struct *work)
605 {
606 struct ntb_transport_qp *qp = container_of(work,
607 struct ntb_transport_qp,
608 link_cleanup);
609 struct ntb_transport *nt = qp->transport;
610
611 ntb_qp_link_cleanup(qp);
612
613 if (nt->transport_link == NTB_LINK_UP)
614 schedule_delayed_work(&qp->link_work,
615 msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
616 }
617
618 static void ntb_qp_link_down(struct ntb_transport_qp *qp)
619 {
620 schedule_work(&qp->link_cleanup);
621 }
622
623 static void ntb_transport_link_cleanup(struct ntb_transport *nt)
624 {
625 int i;
626
627 /* Pass along the info to any clients */
628 for (i = 0; i < nt->max_qps; i++)
629 if (!test_bit(i, &nt->qp_bitmap))
630 ntb_qp_link_cleanup(&nt->qps[i]);
631
632 if (nt->transport_link == NTB_LINK_DOWN)
633 cancel_delayed_work_sync(&nt->link_work);
634 else
635 nt->transport_link = NTB_LINK_DOWN;
636
637 /* The scratchpad registers keep the values if the remote side
638 * goes down, blast them now to give them a sane value the next
639 * time they are accessed
640 */
641 for (i = 0; i < MAX_SPAD; i++)
642 ntb_write_local_spad(nt->ndev, i, 0);
643 }
644
645 static void ntb_transport_link_cleanup_work(struct work_struct *work)
646 {
647 struct ntb_transport *nt = container_of(work, struct ntb_transport,
648 link_cleanup);
649
650 ntb_transport_link_cleanup(nt);
651 }
652
653 static void ntb_transport_event_callback(void *data, enum ntb_hw_event event)
654 {
655 struct ntb_transport *nt = data;
656
657 switch (event) {
658 case NTB_EVENT_HW_LINK_UP:
659 schedule_delayed_work(&nt->link_work, 0);
660 break;
661 case NTB_EVENT_HW_LINK_DOWN:
662 schedule_work(&nt->link_cleanup);
663 break;
664 default:
665 BUG();
666 }
667 }
668
669 static void ntb_transport_link_work(struct work_struct *work)
670 {
671 struct ntb_transport *nt = container_of(work, struct ntb_transport,
672 link_work.work);
673 struct ntb_device *ndev = nt->ndev;
674 struct pci_dev *pdev = ntb_query_pdev(ndev);
675 u32 val;
676 int rc, i;
677
678 /* send the local info, in the opposite order of the way we read it */
679 for (i = 0; i < ntb_max_mw(ndev); i++) {
680 rc = ntb_write_remote_spad(ndev, MW0_SZ_HIGH + (i * 2),
681 ntb_get_mw_size(ndev, i) >> 32);
682 if (rc) {
683 dev_err(&pdev->dev, "Error writing %u to remote spad %d\n",
684 (u32)(ntb_get_mw_size(ndev, i) >> 32),
685 MW0_SZ_HIGH + (i * 2));
686 goto out;
687 }
688
689 rc = ntb_write_remote_spad(ndev, MW0_SZ_LOW + (i * 2),
690 (u32) ntb_get_mw_size(ndev, i));
691 if (rc) {
692 dev_err(&pdev->dev, "Error writing %u to remote spad %d\n",
693 (u32) ntb_get_mw_size(ndev, i),
694 MW0_SZ_LOW + (i * 2));
695 goto out;
696 }
697 }
698
699 rc = ntb_write_remote_spad(ndev, NUM_MWS, ntb_max_mw(ndev));
700 if (rc) {
701 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
702 ntb_max_mw(ndev), NUM_MWS);
703 goto out;
704 }
705
706 rc = ntb_write_remote_spad(ndev, NUM_QPS, nt->max_qps);
707 if (rc) {
708 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
709 nt->max_qps, NUM_QPS);
710 goto out;
711 }
712
713 rc = ntb_write_remote_spad(ndev, VERSION, NTB_TRANSPORT_VERSION);
714 if (rc) {
715 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
716 NTB_TRANSPORT_VERSION, VERSION);
717 goto out;
718 }
719
720 /* Query the remote side for its info */
721 rc = ntb_read_remote_spad(ndev, VERSION, &val);
722 if (rc) {
723 dev_err(&pdev->dev, "Error reading remote spad %d\n", VERSION);
724 goto out;
725 }
726
727 if (val != NTB_TRANSPORT_VERSION)
728 goto out;
729 dev_dbg(&pdev->dev, "Remote version = %d\n", val);
730
731 rc = ntb_read_remote_spad(ndev, NUM_QPS, &val);
732 if (rc) {
733 dev_err(&pdev->dev, "Error reading remote spad %d\n", NUM_QPS);
734 goto out;
735 }
736
737 if (val != nt->max_qps)
738 goto out;
739 dev_dbg(&pdev->dev, "Remote max number of qps = %d\n", val);
740
741 rc = ntb_read_remote_spad(ndev, NUM_MWS, &val);
742 if (rc) {
743 dev_err(&pdev->dev, "Error reading remote spad %d\n", NUM_MWS);
744 goto out;
745 }
746
747 if (val != ntb_max_mw(ndev))
748 goto out;
749 dev_dbg(&pdev->dev, "Remote number of mws = %d\n", val);
750
751 for (i = 0; i < ntb_max_mw(ndev); i++) {
752 u64 val64;
753
754 rc = ntb_read_remote_spad(ndev, MW0_SZ_HIGH + (i * 2), &val);
755 if (rc) {
756 dev_err(&pdev->dev, "Error reading remote spad %d\n",
757 MW0_SZ_HIGH + (i * 2));
758 goto out1;
759 }
760
761 val64 = (u64) val << 32;
762
763 rc = ntb_read_remote_spad(ndev, MW0_SZ_LOW + (i * 2), &val);
764 if (rc) {
765 dev_err(&pdev->dev, "Error reading remote spad %d\n",
766 MW0_SZ_LOW + (i * 2));
767 goto out1;
768 }
769
770 val64 |= val;
771
772 dev_dbg(&pdev->dev, "Remote MW%d size = %llu\n", i, val64);
773
774 rc = ntb_set_mw(nt, i, val64);
775 if (rc)
776 goto out1;
777 }
778
779 nt->transport_link = NTB_LINK_UP;
780
781 for (i = 0; i < nt->max_qps; i++) {
782 struct ntb_transport_qp *qp = &nt->qps[i];
783
784 ntb_transport_setup_qp_mw(nt, i);
785
786 if (qp->client_ready == NTB_LINK_UP)
787 schedule_delayed_work(&qp->link_work, 0);
788 }
789
790 return;
791
792 out1:
793 for (i = 0; i < ntb_max_mw(ndev); i++)
794 ntb_free_mw(nt, i);
795 out:
796 if (ntb_hw_link_status(ndev))
797 schedule_delayed_work(&nt->link_work,
798 msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
799 }
800
801 static void ntb_qp_link_work(struct work_struct *work)
802 {
803 struct ntb_transport_qp *qp = container_of(work,
804 struct ntb_transport_qp,
805 link_work.work);
806 struct pci_dev *pdev = ntb_query_pdev(qp->ndev);
807 struct ntb_transport *nt = qp->transport;
808 int rc, val;
809
810 WARN_ON(nt->transport_link != NTB_LINK_UP);
811
812 rc = ntb_read_local_spad(nt->ndev, QP_LINKS, &val);
813 if (rc) {
814 dev_err(&pdev->dev, "Error reading spad %d\n", QP_LINKS);
815 return;
816 }
817
818 rc = ntb_write_remote_spad(nt->ndev, QP_LINKS, val | 1 << qp->qp_num);
819 if (rc)
820 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
821 val | 1 << qp->qp_num, QP_LINKS);
822
823 /* query remote spad for qp ready bits */
824 rc = ntb_read_remote_spad(nt->ndev, QP_LINKS, &val);
825 if (rc)
826 dev_err(&pdev->dev, "Error reading remote spad %d\n", QP_LINKS);
827
828 dev_dbg(&pdev->dev, "Remote QP link status = %x\n", val);
829
830 /* See if the remote side is up */
831 if (1 << qp->qp_num & val) {
832 qp->qp_link = NTB_LINK_UP;
833
834 dev_info(&pdev->dev, "qp %d: Link Up\n", qp->qp_num);
835 if (qp->event_handler)
836 qp->event_handler(qp->cb_data, NTB_LINK_UP);
837 } else if (nt->transport_link == NTB_LINK_UP)
838 schedule_delayed_work(&qp->link_work,
839 msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
840 }
841
842 static int ntb_transport_init_queue(struct ntb_transport *nt,
843 unsigned int qp_num)
844 {
845 struct ntb_transport_qp *qp;
846 unsigned int num_qps_mw, tx_size;
847 u8 mw_num, mw_max;
848 u64 qp_offset;
849
850 mw_max = ntb_max_mw(nt->ndev);
851 mw_num = QP_TO_MW(nt->ndev, qp_num);
852
853 qp = &nt->qps[qp_num];
854 qp->qp_num = qp_num;
855 qp->transport = nt;
856 qp->ndev = nt->ndev;
857 qp->qp_link = NTB_LINK_DOWN;
858 qp->client_ready = NTB_LINK_DOWN;
859 qp->event_handler = NULL;
860
861 if (nt->max_qps % mw_max && mw_num < nt->max_qps % mw_max)
862 num_qps_mw = nt->max_qps / mw_max + 1;
863 else
864 num_qps_mw = nt->max_qps / mw_max;
865
866 tx_size = (unsigned int) ntb_get_mw_size(qp->ndev, mw_num) / num_qps_mw;
867 qp_offset = qp_num / mw_max * tx_size;
868 qp->tx_mw = ntb_get_mw_vbase(nt->ndev, mw_num) + qp_offset;
869 if (!qp->tx_mw)
870 return -EINVAL;
871
872 qp->tx_mw_phys = ntb_get_mw_base(qp->ndev, mw_num) + qp_offset;
873 if (!qp->tx_mw_phys)
874 return -EINVAL;
875
876 tx_size -= sizeof(struct ntb_rx_info);
877 qp->rx_info = qp->tx_mw + tx_size;
878
879 /* Due to housekeeping, there must be atleast 2 buffs */
880 qp->tx_max_frame = min(transport_mtu, tx_size / 2);
881 qp->tx_max_entry = tx_size / qp->tx_max_frame;
882
883 if (ntb_query_debugfs(nt->ndev)) {
884 char debugfs_name[4];
885
886 snprintf(debugfs_name, 4, "qp%d", qp_num);
887 qp->debugfs_dir = debugfs_create_dir(debugfs_name,
888 ntb_query_debugfs(nt->ndev));
889
890 qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR,
891 qp->debugfs_dir, qp,
892 &ntb_qp_debugfs_stats);
893 }
894
895 INIT_DELAYED_WORK(&qp->link_work, ntb_qp_link_work);
896 INIT_WORK(&qp->link_cleanup, ntb_qp_link_cleanup_work);
897
898 spin_lock_init(&qp->ntb_rx_pend_q_lock);
899 spin_lock_init(&qp->ntb_rx_free_q_lock);
900 spin_lock_init(&qp->ntb_tx_free_q_lock);
901
902 INIT_LIST_HEAD(&qp->rx_pend_q);
903 INIT_LIST_HEAD(&qp->rx_free_q);
904 INIT_LIST_HEAD(&qp->tx_free_q);
905
906 return 0;
907 }
908
909 int ntb_transport_init(struct pci_dev *pdev)
910 {
911 struct ntb_transport *nt;
912 int rc, i;
913
914 nt = kzalloc(sizeof(struct ntb_transport), GFP_KERNEL);
915 if (!nt)
916 return -ENOMEM;
917
918 nt->ndev = ntb_register_transport(pdev, nt);
919 if (!nt->ndev) {
920 rc = -EIO;
921 goto err;
922 }
923
924 nt->mw = kcalloc(ntb_max_mw(nt->ndev), sizeof(struct ntb_transport_mw),
925 GFP_KERNEL);
926 if (!nt->mw) {
927 rc = -ENOMEM;
928 goto err1;
929 }
930
931 if (max_num_clients)
932 nt->max_qps = min(ntb_max_cbs(nt->ndev), max_num_clients);
933 else
934 nt->max_qps = min(ntb_max_cbs(nt->ndev), ntb_max_mw(nt->ndev));
935
936 nt->qps = kcalloc(nt->max_qps, sizeof(struct ntb_transport_qp),
937 GFP_KERNEL);
938 if (!nt->qps) {
939 rc = -ENOMEM;
940 goto err2;
941 }
942
943 nt->qp_bitmap = ((u64) 1 << nt->max_qps) - 1;
944
945 for (i = 0; i < nt->max_qps; i++) {
946 rc = ntb_transport_init_queue(nt, i);
947 if (rc)
948 goto err3;
949 }
950
951 INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work);
952 INIT_WORK(&nt->link_cleanup, ntb_transport_link_cleanup_work);
953
954 rc = ntb_register_event_callback(nt->ndev,
955 ntb_transport_event_callback);
956 if (rc)
957 goto err3;
958
959 INIT_LIST_HEAD(&nt->client_devs);
960 rc = ntb_bus_init(nt);
961 if (rc)
962 goto err4;
963
964 if (ntb_hw_link_status(nt->ndev))
965 schedule_delayed_work(&nt->link_work, 0);
966
967 return 0;
968
969 err4:
970 ntb_unregister_event_callback(nt->ndev);
971 err3:
972 kfree(nt->qps);
973 err2:
974 kfree(nt->mw);
975 err1:
976 ntb_unregister_transport(nt->ndev);
977 err:
978 kfree(nt);
979 return rc;
980 }
981
982 void ntb_transport_free(void *transport)
983 {
984 struct ntb_transport *nt = transport;
985 struct ntb_device *ndev = nt->ndev;
986 int i;
987
988 ntb_transport_link_cleanup(nt);
989
990 /* verify that all the qp's are freed */
991 for (i = 0; i < nt->max_qps; i++) {
992 if (!test_bit(i, &nt->qp_bitmap))
993 ntb_transport_free_queue(&nt->qps[i]);
994 debugfs_remove_recursive(nt->qps[i].debugfs_dir);
995 }
996
997 ntb_bus_remove(nt);
998
999 cancel_delayed_work_sync(&nt->link_work);
1000
1001 ntb_unregister_event_callback(ndev);
1002
1003 for (i = 0; i < ntb_max_mw(ndev); i++)
1004 ntb_free_mw(nt, i);
1005
1006 kfree(nt->qps);
1007 kfree(nt->mw);
1008 ntb_unregister_transport(ndev);
1009 kfree(nt);
1010 }
1011
1012 static void ntb_rx_copy_callback(void *data)
1013 {
1014 struct ntb_queue_entry *entry = data;
1015 struct ntb_transport_qp *qp = entry->qp;
1016 void *cb_data = entry->cb_data;
1017 unsigned int len = entry->len;
1018 struct ntb_payload_header *hdr = entry->rx_hdr;
1019
1020 /* Ensure that the data is fully copied out before clearing the flag */
1021 wmb();
1022 hdr->flags = 0;
1023
1024 iowrite32(entry->index, &qp->rx_info->entry);
1025
1026 ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry, &qp->rx_free_q);
1027
1028 if (qp->rx_handler && qp->client_ready == NTB_LINK_UP)
1029 qp->rx_handler(qp, qp->cb_data, cb_data, len);
1030 }
1031
1032 static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void *offset)
1033 {
1034 void *buf = entry->buf;
1035 size_t len = entry->len;
1036
1037 memcpy(buf, offset, len);
1038
1039 ntb_rx_copy_callback(entry);
1040 }
1041
1042 static void ntb_async_rx(struct ntb_queue_entry *entry, void *offset,
1043 size_t len)
1044 {
1045 struct dma_async_tx_descriptor *txd;
1046 struct ntb_transport_qp *qp = entry->qp;
1047 struct dma_chan *chan = qp->dma_chan;
1048 struct dma_device *device;
1049 size_t pay_off, buff_off;
1050 dma_addr_t src, dest;
1051 dma_cookie_t cookie;
1052 void *buf = entry->buf;
1053 unsigned long flags;
1054
1055 entry->len = len;
1056
1057 if (!chan)
1058 goto err;
1059
1060 if (len < copy_bytes)
1061 goto err1;
1062
1063 device = chan->device;
1064 pay_off = (size_t) offset & ~PAGE_MASK;
1065 buff_off = (size_t) buf & ~PAGE_MASK;
1066
1067 if (!is_dma_copy_aligned(device, pay_off, buff_off, len))
1068 goto err1;
1069
1070 dest = dma_map_single(device->dev, buf, len, DMA_FROM_DEVICE);
1071 if (dma_mapping_error(device->dev, dest))
1072 goto err1;
1073
1074 src = dma_map_single(device->dev, offset, len, DMA_TO_DEVICE);
1075 if (dma_mapping_error(device->dev, src))
1076 goto err2;
1077
1078 flags = DMA_COMPL_DEST_UNMAP_SINGLE | DMA_COMPL_SRC_UNMAP_SINGLE |
1079 DMA_PREP_INTERRUPT;
1080 txd = device->device_prep_dma_memcpy(chan, dest, src, len, flags);
1081 if (!txd)
1082 goto err3;
1083
1084 txd->callback = ntb_rx_copy_callback;
1085 txd->callback_param = entry;
1086
1087 cookie = dmaengine_submit(txd);
1088 if (dma_submit_error(cookie))
1089 goto err3;
1090
1091 qp->last_cookie = cookie;
1092
1093 qp->rx_async++;
1094
1095 return;
1096
1097 err3:
1098 dma_unmap_single(device->dev, src, len, DMA_TO_DEVICE);
1099 err2:
1100 dma_unmap_single(device->dev, dest, len, DMA_FROM_DEVICE);
1101 err1:
1102 /* If the callbacks come out of order, the writing of the index to the
1103 * last completed will be out of order. This may result in the
1104 * receive stalling forever.
1105 */
1106 dma_sync_wait(chan, qp->last_cookie);
1107 err:
1108 ntb_memcpy_rx(entry, offset);
1109 qp->rx_memcpy++;
1110 }
1111
1112 static int ntb_process_rxc(struct ntb_transport_qp *qp)
1113 {
1114 struct ntb_payload_header *hdr;
1115 struct ntb_queue_entry *entry;
1116 void *offset;
1117
1118 offset = qp->rx_buff + qp->rx_max_frame * qp->rx_index;
1119 hdr = offset + qp->rx_max_frame - sizeof(struct ntb_payload_header);
1120
1121 entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q);
1122 if (!entry) {
1123 dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
1124 "no buffer - HDR ver %u, len %d, flags %x\n",
1125 hdr->ver, hdr->len, hdr->flags);
1126 qp->rx_err_no_buf++;
1127 return -ENOMEM;
1128 }
1129
1130 if (!(hdr->flags & DESC_DONE_FLAG)) {
1131 ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
1132 &qp->rx_pend_q);
1133 qp->rx_ring_empty++;
1134 return -EAGAIN;
1135 }
1136
1137 if (hdr->ver != (u32) qp->rx_pkts) {
1138 dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
1139 "qp %d: version mismatch, expected %llu - got %u\n",
1140 qp->qp_num, qp->rx_pkts, hdr->ver);
1141 ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
1142 &qp->rx_pend_q);
1143 qp->rx_err_ver++;
1144 return -EIO;
1145 }
1146
1147 if (hdr->flags & LINK_DOWN_FLAG) {
1148 ntb_qp_link_down(qp);
1149
1150 goto err;
1151 }
1152
1153 dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
1154 "rx offset %u, ver %u - %d payload received, buf size %d\n",
1155 qp->rx_index, hdr->ver, hdr->len, entry->len);
1156
1157 qp->rx_bytes += hdr->len;
1158 qp->rx_pkts++;
1159
1160 if (hdr->len > entry->len) {
1161 qp->rx_err_oflow++;
1162 dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
1163 "RX overflow! Wanted %d got %d\n",
1164 hdr->len, entry->len);
1165
1166 goto err;
1167 }
1168
1169 entry->index = qp->rx_index;
1170 entry->rx_hdr = hdr;
1171
1172 ntb_async_rx(entry, offset, hdr->len);
1173
1174 out:
1175 qp->rx_index++;
1176 qp->rx_index %= qp->rx_max_entry;
1177
1178 return 0;
1179
1180 err:
1181 ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
1182 &qp->rx_pend_q);
1183 /* Ensure that the data is fully copied out before clearing the flag */
1184 wmb();
1185 hdr->flags = 0;
1186 iowrite32(qp->rx_index, &qp->rx_info->entry);
1187
1188 goto out;
1189 }
1190
1191 static void ntb_transport_rx(unsigned long data)
1192 {
1193 struct ntb_transport_qp *qp = (struct ntb_transport_qp *)data;
1194 int rc, i;
1195
1196 /* Limit the number of packets processed in a single interrupt to
1197 * provide fairness to others
1198 */
1199 for (i = 0; i < qp->rx_max_entry; i++) {
1200 rc = ntb_process_rxc(qp);
1201 if (rc)
1202 break;
1203 }
1204
1205 if (qp->dma_chan)
1206 dma_async_issue_pending(qp->dma_chan);
1207 }
1208
1209 static void ntb_transport_rxc_db(void *data, int db_num)
1210 {
1211 struct ntb_transport_qp *qp = data;
1212
1213 dev_dbg(&ntb_query_pdev(qp->ndev)->dev, "%s: doorbell %d received\n",
1214 __func__, db_num);
1215
1216 tasklet_schedule(&qp->rx_work);
1217 }
1218
1219 static void ntb_tx_copy_callback(void *data)
1220 {
1221 struct ntb_queue_entry *entry = data;
1222 struct ntb_transport_qp *qp = entry->qp;
1223 struct ntb_payload_header __iomem *hdr = entry->tx_hdr;
1224
1225 /* Ensure that the data is fully copied out before setting the flags */
1226 wmb();
1227 iowrite32(entry->flags | DESC_DONE_FLAG, &hdr->flags);
1228
1229 ntb_ring_doorbell(qp->ndev, qp->qp_num);
1230
1231 /* The entry length can only be zero if the packet is intended to be a
1232 * "link down" or similar. Since no payload is being sent in these
1233 * cases, there is nothing to add to the completion queue.
1234 */
1235 if (entry->len > 0) {
1236 qp->tx_bytes += entry->len;
1237
1238 if (qp->tx_handler)
1239 qp->tx_handler(qp, qp->cb_data, entry->cb_data,
1240 entry->len);
1241 }
1242
1243 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q);
1244 }
1245
1246 static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset)
1247 {
1248 memcpy_toio(offset, entry->buf, entry->len);
1249
1250 ntb_tx_copy_callback(entry);
1251 }
1252
1253 static void ntb_async_tx(struct ntb_transport_qp *qp,
1254 struct ntb_queue_entry *entry)
1255 {
1256 struct ntb_payload_header __iomem *hdr;
1257 struct dma_async_tx_descriptor *txd;
1258 struct dma_chan *chan = qp->dma_chan;
1259 struct dma_device *device;
1260 size_t dest_off, buff_off;
1261 dma_addr_t src, dest;
1262 dma_cookie_t cookie;
1263 void __iomem *offset;
1264 size_t len = entry->len;
1265 void *buf = entry->buf;
1266 unsigned long flags;
1267
1268 offset = qp->tx_mw + qp->tx_max_frame * qp->tx_index;
1269 hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
1270 entry->tx_hdr = hdr;
1271
1272 iowrite32(entry->len, &hdr->len);
1273 iowrite32((u32) qp->tx_pkts, &hdr->ver);
1274
1275 if (!chan)
1276 goto err;
1277
1278 if (len < copy_bytes)
1279 goto err;
1280
1281 device = chan->device;
1282 dest = qp->tx_mw_phys + qp->tx_max_frame * qp->tx_index;
1283 buff_off = (size_t) buf & ~PAGE_MASK;
1284 dest_off = (size_t) dest & ~PAGE_MASK;
1285
1286 if (!is_dma_copy_aligned(device, buff_off, dest_off, len))
1287 goto err;
1288
1289 src = dma_map_single(device->dev, buf, len, DMA_TO_DEVICE);
1290 if (dma_mapping_error(device->dev, src))
1291 goto err;
1292
1293 flags = DMA_COMPL_SRC_UNMAP_SINGLE | DMA_PREP_INTERRUPT;
1294 txd = device->device_prep_dma_memcpy(chan, dest, src, len, flags);
1295 if (!txd)
1296 goto err1;
1297
1298 txd->callback = ntb_tx_copy_callback;
1299 txd->callback_param = entry;
1300
1301 cookie = dmaengine_submit(txd);
1302 if (dma_submit_error(cookie))
1303 goto err1;
1304
1305 dma_async_issue_pending(chan);
1306 qp->tx_async++;
1307
1308 return;
1309 err1:
1310 dma_unmap_single(device->dev, src, len, DMA_TO_DEVICE);
1311 err:
1312 ntb_memcpy_tx(entry, offset);
1313 qp->tx_memcpy++;
1314 }
1315
1316 static int ntb_process_tx(struct ntb_transport_qp *qp,
1317 struct ntb_queue_entry *entry)
1318 {
1319 dev_dbg(&ntb_query_pdev(qp->ndev)->dev, "%lld - tx %u, entry len %d flags %x buff %p\n",
1320 qp->tx_pkts, qp->tx_index, entry->len, entry->flags,
1321 entry->buf);
1322 if (qp->tx_index == qp->remote_rx_info->entry) {
1323 qp->tx_ring_full++;
1324 return -EAGAIN;
1325 }
1326
1327 if (entry->len > qp->tx_max_frame - sizeof(struct ntb_payload_header)) {
1328 if (qp->tx_handler)
1329 qp->tx_handler(qp->cb_data, qp, NULL, -EIO);
1330
1331 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1332 &qp->tx_free_q);
1333 return 0;
1334 }
1335
1336 ntb_async_tx(qp, entry);
1337
1338 qp->tx_index++;
1339 qp->tx_index %= qp->tx_max_entry;
1340
1341 qp->tx_pkts++;
1342
1343 return 0;
1344 }
1345
1346 static void ntb_send_link_down(struct ntb_transport_qp *qp)
1347 {
1348 struct pci_dev *pdev = ntb_query_pdev(qp->ndev);
1349 struct ntb_queue_entry *entry;
1350 int i, rc;
1351
1352 if (qp->qp_link == NTB_LINK_DOWN)
1353 return;
1354
1355 qp->qp_link = NTB_LINK_DOWN;
1356 dev_info(&pdev->dev, "qp %d: Link Down\n", qp->qp_num);
1357
1358 for (i = 0; i < NTB_LINK_DOWN_TIMEOUT; i++) {
1359 entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1360 if (entry)
1361 break;
1362 msleep(100);
1363 }
1364
1365 if (!entry)
1366 return;
1367
1368 entry->cb_data = NULL;
1369 entry->buf = NULL;
1370 entry->len = 0;
1371 entry->flags = LINK_DOWN_FLAG;
1372
1373 rc = ntb_process_tx(qp, entry);
1374 if (rc)
1375 dev_err(&pdev->dev, "ntb: QP%d unable to send linkdown msg\n",
1376 qp->qp_num);
1377 }
1378
1379 /**
1380 * ntb_transport_create_queue - Create a new NTB transport layer queue
1381 * @rx_handler: receive callback function
1382 * @tx_handler: transmit callback function
1383 * @event_handler: event callback function
1384 *
1385 * Create a new NTB transport layer queue and provide the queue with a callback
1386 * routine for both transmit and receive. The receive callback routine will be
1387 * used to pass up data when the transport has received it on the queue. The
1388 * transmit callback routine will be called when the transport has completed the
1389 * transmission of the data on the queue and the data is ready to be freed.
1390 *
1391 * RETURNS: pointer to newly created ntb_queue, NULL on error.
1392 */
1393 struct ntb_transport_qp *
1394 ntb_transport_create_queue(void *data, struct pci_dev *pdev,
1395 const struct ntb_queue_handlers *handlers)
1396 {
1397 struct ntb_queue_entry *entry;
1398 struct ntb_transport_qp *qp;
1399 struct ntb_transport *nt;
1400 unsigned int free_queue;
1401 int rc, i;
1402
1403 nt = ntb_find_transport(pdev);
1404 if (!nt)
1405 goto err;
1406
1407 free_queue = ffs(nt->qp_bitmap);
1408 if (!free_queue)
1409 goto err;
1410
1411 /* decrement free_queue to make it zero based */
1412 free_queue--;
1413
1414 clear_bit(free_queue, &nt->qp_bitmap);
1415
1416 qp = &nt->qps[free_queue];
1417 qp->cb_data = data;
1418 qp->rx_handler = handlers->rx_handler;
1419 qp->tx_handler = handlers->tx_handler;
1420 qp->event_handler = handlers->event_handler;
1421
1422 qp->dma_chan = dma_find_channel(DMA_MEMCPY);
1423 if (!qp->dma_chan)
1424 dev_info(&pdev->dev, "Unable to allocate DMA channel, using CPU instead\n");
1425 else
1426 dmaengine_get();
1427
1428 for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
1429 entry = kzalloc(sizeof(struct ntb_queue_entry), GFP_ATOMIC);
1430 if (!entry)
1431 goto err1;
1432
1433 entry->qp = qp;
1434 ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry,
1435 &qp->rx_free_q);
1436 }
1437
1438 for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
1439 entry = kzalloc(sizeof(struct ntb_queue_entry), GFP_ATOMIC);
1440 if (!entry)
1441 goto err2;
1442
1443 entry->qp = qp;
1444 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1445 &qp->tx_free_q);
1446 }
1447
1448 tasklet_init(&qp->rx_work, ntb_transport_rx, (unsigned long) qp);
1449
1450 rc = ntb_register_db_callback(qp->ndev, free_queue, qp,
1451 ntb_transport_rxc_db);
1452 if (rc)
1453 goto err3;
1454
1455 dev_info(&pdev->dev, "NTB Transport QP %d created\n", qp->qp_num);
1456
1457 return qp;
1458
1459 err3:
1460 tasklet_disable(&qp->rx_work);
1461 err2:
1462 while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1463 kfree(entry);
1464 err1:
1465 while ((entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q)))
1466 kfree(entry);
1467 set_bit(free_queue, &nt->qp_bitmap);
1468 err:
1469 return NULL;
1470 }
1471 EXPORT_SYMBOL_GPL(ntb_transport_create_queue);
1472
1473 /**
1474 * ntb_transport_free_queue - Frees NTB transport queue
1475 * @qp: NTB queue to be freed
1476 *
1477 * Frees NTB transport queue
1478 */
1479 void ntb_transport_free_queue(struct ntb_transport_qp *qp)
1480 {
1481 struct pci_dev *pdev;
1482 struct ntb_queue_entry *entry;
1483
1484 if (!qp)
1485 return;
1486
1487 pdev = ntb_query_pdev(qp->ndev);
1488
1489 if (qp->dma_chan) {
1490 struct dma_chan *chan = qp->dma_chan;
1491 /* Putting the dma_chan to NULL will force any new traffic to be
1492 * processed by the CPU instead of the DAM engine
1493 */
1494 qp->dma_chan = NULL;
1495
1496 /* Try to be nice and wait for any queued DMA engine
1497 * transactions to process before smashing it with a rock
1498 */
1499 dma_sync_wait(chan, qp->last_cookie);
1500 dmaengine_terminate_all(chan);
1501 dmaengine_put();
1502 }
1503
1504 ntb_unregister_db_callback(qp->ndev, qp->qp_num);
1505 tasklet_disable(&qp->rx_work);
1506
1507 cancel_delayed_work_sync(&qp->link_work);
1508
1509 while ((entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q)))
1510 kfree(entry);
1511
1512 while ((entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q))) {
1513 dev_warn(&pdev->dev, "Freeing item from a non-empty queue\n");
1514 kfree(entry);
1515 }
1516
1517 while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1518 kfree(entry);
1519
1520 set_bit(qp->qp_num, &qp->transport->qp_bitmap);
1521
1522 dev_info(&pdev->dev, "NTB Transport QP %d freed\n", qp->qp_num);
1523 }
1524 EXPORT_SYMBOL_GPL(ntb_transport_free_queue);
1525
1526 /**
1527 * ntb_transport_rx_remove - Dequeues enqueued rx packet
1528 * @qp: NTB queue to be freed
1529 * @len: pointer to variable to write enqueued buffers length
1530 *
1531 * Dequeues unused buffers from receive queue. Should only be used during
1532 * shutdown of qp.
1533 *
1534 * RETURNS: NULL error value on error, or void* for success.
1535 */
1536 void *ntb_transport_rx_remove(struct ntb_transport_qp *qp, unsigned int *len)
1537 {
1538 struct ntb_queue_entry *entry;
1539 void *buf;
1540
1541 if (!qp || qp->client_ready == NTB_LINK_UP)
1542 return NULL;
1543
1544 entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q);
1545 if (!entry)
1546 return NULL;
1547
1548 buf = entry->cb_data;
1549 *len = entry->len;
1550
1551 ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry, &qp->rx_free_q);
1552
1553 return buf;
1554 }
1555 EXPORT_SYMBOL_GPL(ntb_transport_rx_remove);
1556
1557 /**
1558 * ntb_transport_rx_enqueue - Enqueue a new NTB queue entry
1559 * @qp: NTB transport layer queue the entry is to be enqueued on
1560 * @cb: per buffer pointer for callback function to use
1561 * @data: pointer to data buffer that incoming packets will be copied into
1562 * @len: length of the data buffer
1563 *
1564 * Enqueue a new receive buffer onto the transport queue into which a NTB
1565 * payload can be received into.
1566 *
1567 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
1568 */
1569 int ntb_transport_rx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
1570 unsigned int len)
1571 {
1572 struct ntb_queue_entry *entry;
1573
1574 if (!qp)
1575 return -EINVAL;
1576
1577 entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q);
1578 if (!entry)
1579 return -ENOMEM;
1580
1581 entry->cb_data = cb;
1582 entry->buf = data;
1583 entry->len = len;
1584
1585 ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry, &qp->rx_pend_q);
1586
1587 return 0;
1588 }
1589 EXPORT_SYMBOL_GPL(ntb_transport_rx_enqueue);
1590
1591 /**
1592 * ntb_transport_tx_enqueue - Enqueue a new NTB queue entry
1593 * @qp: NTB transport layer queue the entry is to be enqueued on
1594 * @cb: per buffer pointer for callback function to use
1595 * @data: pointer to data buffer that will be sent
1596 * @len: length of the data buffer
1597 *
1598 * Enqueue a new transmit buffer onto the transport queue from which a NTB
1599 * payload will be transmitted. This assumes that a lock is being held to
1600 * serialize access to the qp.
1601 *
1602 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
1603 */
1604 int ntb_transport_tx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
1605 unsigned int len)
1606 {
1607 struct ntb_queue_entry *entry;
1608 int rc;
1609
1610 if (!qp || qp->qp_link != NTB_LINK_UP || !len)
1611 return -EINVAL;
1612
1613 entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1614 if (!entry) {
1615 qp->tx_err_no_buf++;
1616 return -ENOMEM;
1617 }
1618
1619 entry->cb_data = cb;
1620 entry->buf = data;
1621 entry->len = len;
1622 entry->flags = 0;
1623
1624 rc = ntb_process_tx(qp, entry);
1625 if (rc)
1626 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1627 &qp->tx_free_q);
1628
1629 return rc;
1630 }
1631 EXPORT_SYMBOL_GPL(ntb_transport_tx_enqueue);
1632
1633 /**
1634 * ntb_transport_link_up - Notify NTB transport of client readiness to use queue
1635 * @qp: NTB transport layer queue to be enabled
1636 *
1637 * Notify NTB transport layer of client readiness to use queue
1638 */
1639 void ntb_transport_link_up(struct ntb_transport_qp *qp)
1640 {
1641 if (!qp)
1642 return;
1643
1644 qp->client_ready = NTB_LINK_UP;
1645
1646 if (qp->transport->transport_link == NTB_LINK_UP)
1647 schedule_delayed_work(&qp->link_work, 0);
1648 }
1649 EXPORT_SYMBOL_GPL(ntb_transport_link_up);
1650
1651 /**
1652 * ntb_transport_link_down - Notify NTB transport to no longer enqueue data
1653 * @qp: NTB transport layer queue to be disabled
1654 *
1655 * Notify NTB transport layer of client's desire to no longer receive data on
1656 * transport queue specified. It is the client's responsibility to ensure all
1657 * entries on queue are purged or otherwise handled appropriately.
1658 */
1659 void ntb_transport_link_down(struct ntb_transport_qp *qp)
1660 {
1661 struct pci_dev *pdev;
1662 int rc, val;
1663
1664 if (!qp)
1665 return;
1666
1667 pdev = ntb_query_pdev(qp->ndev);
1668 qp->client_ready = NTB_LINK_DOWN;
1669
1670 rc = ntb_read_local_spad(qp->ndev, QP_LINKS, &val);
1671 if (rc) {
1672 dev_err(&pdev->dev, "Error reading spad %d\n", QP_LINKS);
1673 return;
1674 }
1675
1676 rc = ntb_write_remote_spad(qp->ndev, QP_LINKS,
1677 val & ~(1 << qp->qp_num));
1678 if (rc)
1679 dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
1680 val & ~(1 << qp->qp_num), QP_LINKS);
1681
1682 if (qp->qp_link == NTB_LINK_UP)
1683 ntb_send_link_down(qp);
1684 else
1685 cancel_delayed_work_sync(&qp->link_work);
1686 }
1687 EXPORT_SYMBOL_GPL(ntb_transport_link_down);
1688
1689 /**
1690 * ntb_transport_link_query - Query transport link state
1691 * @qp: NTB transport layer queue to be queried
1692 *
1693 * Query connectivity to the remote system of the NTB transport queue
1694 *
1695 * RETURNS: true for link up or false for link down
1696 */
1697 bool ntb_transport_link_query(struct ntb_transport_qp *qp)
1698 {
1699 if (!qp)
1700 return false;
1701
1702 return qp->qp_link == NTB_LINK_UP;
1703 }
1704 EXPORT_SYMBOL_GPL(ntb_transport_link_query);
1705
1706 /**
1707 * ntb_transport_qp_num - Query the qp number
1708 * @qp: NTB transport layer queue to be queried
1709 *
1710 * Query qp number of the NTB transport queue
1711 *
1712 * RETURNS: a zero based number specifying the qp number
1713 */
1714 unsigned char ntb_transport_qp_num(struct ntb_transport_qp *qp)
1715 {
1716 if (!qp)
1717 return 0;
1718
1719 return qp->qp_num;
1720 }
1721 EXPORT_SYMBOL_GPL(ntb_transport_qp_num);
1722
1723 /**
1724 * ntb_transport_max_size - Query the max payload size of a qp
1725 * @qp: NTB transport layer queue to be queried
1726 *
1727 * Query the maximum payload size permissible on the given qp
1728 *
1729 * RETURNS: the max payload size of a qp
1730 */
1731 unsigned int ntb_transport_max_size(struct ntb_transport_qp *qp)
1732 {
1733 unsigned int max;
1734
1735 if (!qp)
1736 return 0;
1737
1738 if (!qp->dma_chan)
1739 return qp->tx_max_frame - sizeof(struct ntb_payload_header);
1740
1741 /* If DMA engine usage is possible, try to find the max size for that */
1742 max = qp->tx_max_frame - sizeof(struct ntb_payload_header);
1743 max -= max % (1 << qp->dma_chan->device->copy_align);
1744
1745 return max;
1746 }
1747 EXPORT_SYMBOL_GPL(ntb_transport_max_size);
Linux kernel - Deliverables
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