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Merge tag 'iio-fixes-for-4.4a' of ssh://ra.kernel.org/pub/scm/linux/kernel/git/jic23...
[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 * Copyright (C) 2015 EMC Corporation. All Rights Reserved.
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of version 2 of the GNU General Public License as
12 * published by the Free Software Foundation.
13 *
14 * BSD LICENSE
15 *
16 * Copyright(c) 2012 Intel Corporation. All rights reserved.
17 * Copyright (C) 2015 EMC Corporation. All Rights Reserved.
18 *
19 * Redistribution and use in source and binary forms, with or without
20 * modification, are permitted provided that the following conditions
21 * are met:
22 *
23 * * Redistributions of source code must retain the above copyright
24 * notice, this list of conditions and the following disclaimer.
25 * * Redistributions in binary form must reproduce the above copy
26 * notice, this list of conditions and the following disclaimer in
27 * the documentation and/or other materials provided with the
28 * distribution.
29 * * Neither the name of Intel Corporation nor the names of its
30 * contributors may be used to endorse or promote products derived
31 * from this software without specific prior written permission.
32 *
33 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
34 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
35 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
36 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
37 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
38 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
39 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
40 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
41 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
42 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
43 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
44 *
45 * PCIe NTB Transport Linux driver
46 *
47 * Contact Information:
48 * Jon Mason <jon.mason@intel.com>
49 */
50 #include <linux/debugfs.h>
51 #include <linux/delay.h>
52 #include <linux/dmaengine.h>
53 #include <linux/dma-mapping.h>
54 #include <linux/errno.h>
55 #include <linux/export.h>
56 #include <linux/interrupt.h>
57 #include <linux/module.h>
58 #include <linux/pci.h>
59 #include <linux/slab.h>
60 #include <linux/types.h>
61 #include <linux/uaccess.h>
62 #include "linux/ntb.h"
63 #include "linux/ntb_transport.h"
64
65 #define NTB_TRANSPORT_VERSION 4
66 #define NTB_TRANSPORT_VER "4"
67 #define NTB_TRANSPORT_NAME "ntb_transport"
68 #define NTB_TRANSPORT_DESC "Software Queue-Pair Transport over NTB"
69
70 MODULE_DESCRIPTION(NTB_TRANSPORT_DESC);
71 MODULE_VERSION(NTB_TRANSPORT_VER);
72 MODULE_LICENSE("Dual BSD/GPL");
73 MODULE_AUTHOR("Intel Corporation");
74
75 static unsigned long max_mw_size;
76 module_param(max_mw_size, ulong, 0644);
77 MODULE_PARM_DESC(max_mw_size, "Limit size of large memory windows");
78
79 static unsigned int transport_mtu = 0x10000;
80 module_param(transport_mtu, uint, 0644);
81 MODULE_PARM_DESC(transport_mtu, "Maximum size of NTB transport packets");
82
83 static unsigned char max_num_clients;
84 module_param(max_num_clients, byte, 0644);
85 MODULE_PARM_DESC(max_num_clients, "Maximum number of NTB transport clients");
86
87 static unsigned int copy_bytes = 1024;
88 module_param(copy_bytes, uint, 0644);
89 MODULE_PARM_DESC(copy_bytes, "Threshold under which NTB will use the CPU to copy instead of DMA");
90
91 static bool use_dma;
92 module_param(use_dma, bool, 0644);
93 MODULE_PARM_DESC(use_dma, "Use DMA engine to perform large data copy");
94
95 static struct dentry *nt_debugfs_dir;
96
97 struct ntb_queue_entry {
98 /* ntb_queue list reference */
99 struct list_head entry;
100 /* pointers to data to be transferred */
101 void *cb_data;
102 void *buf;
103 unsigned int len;
104 unsigned int flags;
105
106 struct ntb_transport_qp *qp;
107 union {
108 struct ntb_payload_header __iomem *tx_hdr;
109 struct ntb_payload_header *rx_hdr;
110 };
111 unsigned int index;
112 };
113
114 struct ntb_rx_info {
115 unsigned int entry;
116 };
117
118 struct ntb_transport_qp {
119 struct ntb_transport_ctx *transport;
120 struct ntb_dev *ndev;
121 void *cb_data;
122 struct dma_chan *tx_dma_chan;
123 struct dma_chan *rx_dma_chan;
124
125 bool client_ready;
126 bool link_is_up;
127
128 u8 qp_num; /* Only 64 QP's are allowed. 0-63 */
129 u64 qp_bit;
130
131 struct ntb_rx_info __iomem *rx_info;
132 struct ntb_rx_info *remote_rx_info;
133
134 void (*tx_handler)(struct ntb_transport_qp *qp, void *qp_data,
135 void *data, int len);
136 struct list_head tx_free_q;
137 spinlock_t ntb_tx_free_q_lock;
138 void __iomem *tx_mw;
139 dma_addr_t tx_mw_phys;
140 unsigned int tx_index;
141 unsigned int tx_max_entry;
142 unsigned int tx_max_frame;
143
144 void (*rx_handler)(struct ntb_transport_qp *qp, void *qp_data,
145 void *data, int len);
146 struct list_head rx_post_q;
147 struct list_head rx_pend_q;
148 struct list_head rx_free_q;
149 /* ntb_rx_q_lock: synchronize access to rx_XXXX_q */
150 spinlock_t ntb_rx_q_lock;
151 void *rx_buff;
152 unsigned int rx_index;
153 unsigned int rx_max_entry;
154 unsigned int rx_max_frame;
155 dma_cookie_t last_cookie;
156 struct tasklet_struct rxc_db_work;
157
158 void (*event_handler)(void *data, int status);
159 struct delayed_work link_work;
160 struct work_struct link_cleanup;
161
162 struct dentry *debugfs_dir;
163 struct dentry *debugfs_stats;
164
165 /* Stats */
166 u64 rx_bytes;
167 u64 rx_pkts;
168 u64 rx_ring_empty;
169 u64 rx_err_no_buf;
170 u64 rx_err_oflow;
171 u64 rx_err_ver;
172 u64 rx_memcpy;
173 u64 rx_async;
174 u64 tx_bytes;
175 u64 tx_pkts;
176 u64 tx_ring_full;
177 u64 tx_err_no_buf;
178 u64 tx_memcpy;
179 u64 tx_async;
180 };
181
182 struct ntb_transport_mw {
183 phys_addr_t phys_addr;
184 resource_size_t phys_size;
185 resource_size_t xlat_align;
186 resource_size_t xlat_align_size;
187 void __iomem *vbase;
188 size_t xlat_size;
189 size_t buff_size;
190 void *virt_addr;
191 dma_addr_t dma_addr;
192 };
193
194 struct ntb_transport_client_dev {
195 struct list_head entry;
196 struct ntb_transport_ctx *nt;
197 struct device dev;
198 };
199
200 struct ntb_transport_ctx {
201 struct list_head entry;
202 struct list_head client_devs;
203
204 struct ntb_dev *ndev;
205
206 struct ntb_transport_mw *mw_vec;
207 struct ntb_transport_qp *qp_vec;
208 unsigned int mw_count;
209 unsigned int qp_count;
210 u64 qp_bitmap;
211 u64 qp_bitmap_free;
212
213 bool link_is_up;
214 struct delayed_work link_work;
215 struct work_struct link_cleanup;
216
217 struct dentry *debugfs_node_dir;
218 };
219
220 enum {
221 DESC_DONE_FLAG = BIT(0),
222 LINK_DOWN_FLAG = BIT(1),
223 };
224
225 struct ntb_payload_header {
226 unsigned int ver;
227 unsigned int len;
228 unsigned int flags;
229 };
230
231 enum {
232 VERSION = 0,
233 QP_LINKS,
234 NUM_QPS,
235 NUM_MWS,
236 MW0_SZ_HIGH,
237 MW0_SZ_LOW,
238 MW1_SZ_HIGH,
239 MW1_SZ_LOW,
240 MAX_SPAD,
241 };
242
243 #define dev_client_dev(__dev) \
244 container_of((__dev), struct ntb_transport_client_dev, dev)
245
246 #define drv_client(__drv) \
247 container_of((__drv), struct ntb_transport_client, driver)
248
249 #define QP_TO_MW(nt, qp) ((qp) % nt->mw_count)
250 #define NTB_QP_DEF_NUM_ENTRIES 100
251 #define NTB_LINK_DOWN_TIMEOUT 10
252
253 static void ntb_transport_rxc_db(unsigned long data);
254 static const struct ntb_ctx_ops ntb_transport_ops;
255 static struct ntb_client ntb_transport_client;
256
257 static int ntb_transport_bus_match(struct device *dev,
258 struct device_driver *drv)
259 {
260 return !strncmp(dev_name(dev), drv->name, strlen(drv->name));
261 }
262
263 static int ntb_transport_bus_probe(struct device *dev)
264 {
265 const struct ntb_transport_client *client;
266 int rc = -EINVAL;
267
268 get_device(dev);
269
270 client = drv_client(dev->driver);
271 rc = client->probe(dev);
272 if (rc)
273 put_device(dev);
274
275 return rc;
276 }
277
278 static int ntb_transport_bus_remove(struct device *dev)
279 {
280 const struct ntb_transport_client *client;
281
282 client = drv_client(dev->driver);
283 client->remove(dev);
284
285 put_device(dev);
286
287 return 0;
288 }
289
290 static struct bus_type ntb_transport_bus = {
291 .name = "ntb_transport",
292 .match = ntb_transport_bus_match,
293 .probe = ntb_transport_bus_probe,
294 .remove = ntb_transport_bus_remove,
295 };
296
297 static LIST_HEAD(ntb_transport_list);
298
299 static int ntb_bus_init(struct ntb_transport_ctx *nt)
300 {
301 list_add_tail(&nt->entry, &ntb_transport_list);
302 return 0;
303 }
304
305 static void ntb_bus_remove(struct ntb_transport_ctx *nt)
306 {
307 struct ntb_transport_client_dev *client_dev, *cd;
308
309 list_for_each_entry_safe(client_dev, cd, &nt->client_devs, entry) {
310 dev_err(client_dev->dev.parent, "%s still attached to bus, removing\n",
311 dev_name(&client_dev->dev));
312 list_del(&client_dev->entry);
313 device_unregister(&client_dev->dev);
314 }
315
316 list_del(&nt->entry);
317 }
318
319 static void ntb_transport_client_release(struct device *dev)
320 {
321 struct ntb_transport_client_dev *client_dev;
322
323 client_dev = dev_client_dev(dev);
324 kfree(client_dev);
325 }
326
327 /**
328 * ntb_transport_unregister_client_dev - Unregister NTB client device
329 * @device_name: Name of NTB client device
330 *
331 * Unregister an NTB client device with the NTB transport layer
332 */
333 void ntb_transport_unregister_client_dev(char *device_name)
334 {
335 struct ntb_transport_client_dev *client, *cd;
336 struct ntb_transport_ctx *nt;
337
338 list_for_each_entry(nt, &ntb_transport_list, entry)
339 list_for_each_entry_safe(client, cd, &nt->client_devs, entry)
340 if (!strncmp(dev_name(&client->dev), device_name,
341 strlen(device_name))) {
342 list_del(&client->entry);
343 device_unregister(&client->dev);
344 }
345 }
346 EXPORT_SYMBOL_GPL(ntb_transport_unregister_client_dev);
347
348 /**
349 * ntb_transport_register_client_dev - Register NTB client device
350 * @device_name: Name of NTB client device
351 *
352 * Register an NTB client device with the NTB transport layer
353 */
354 int ntb_transport_register_client_dev(char *device_name)
355 {
356 struct ntb_transport_client_dev *client_dev;
357 struct ntb_transport_ctx *nt;
358 int node;
359 int rc, i = 0;
360
361 if (list_empty(&ntb_transport_list))
362 return -ENODEV;
363
364 list_for_each_entry(nt, &ntb_transport_list, entry) {
365 struct device *dev;
366
367 node = dev_to_node(&nt->ndev->dev);
368
369 client_dev = kzalloc_node(sizeof(*client_dev),
370 GFP_KERNEL, node);
371 if (!client_dev) {
372 rc = -ENOMEM;
373 goto err;
374 }
375
376 dev = &client_dev->dev;
377
378 /* setup and register client devices */
379 dev_set_name(dev, "%s%d", device_name, i);
380 dev->bus = &ntb_transport_bus;
381 dev->release = ntb_transport_client_release;
382 dev->parent = &nt->ndev->dev;
383
384 rc = device_register(dev);
385 if (rc) {
386 kfree(client_dev);
387 goto err;
388 }
389
390 list_add_tail(&client_dev->entry, &nt->client_devs);
391 i++;
392 }
393
394 return 0;
395
396 err:
397 ntb_transport_unregister_client_dev(device_name);
398
399 return rc;
400 }
401 EXPORT_SYMBOL_GPL(ntb_transport_register_client_dev);
402
403 /**
404 * ntb_transport_register_client - Register NTB client driver
405 * @drv: NTB client driver to be registered
406 *
407 * Register an NTB client driver with the NTB transport layer
408 *
409 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
410 */
411 int ntb_transport_register_client(struct ntb_transport_client *drv)
412 {
413 drv->driver.bus = &ntb_transport_bus;
414
415 if (list_empty(&ntb_transport_list))
416 return -ENODEV;
417
418 return driver_register(&drv->driver);
419 }
420 EXPORT_SYMBOL_GPL(ntb_transport_register_client);
421
422 /**
423 * ntb_transport_unregister_client - Unregister NTB client driver
424 * @drv: NTB client driver to be unregistered
425 *
426 * Unregister an NTB client driver with the NTB transport layer
427 *
428 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
429 */
430 void ntb_transport_unregister_client(struct ntb_transport_client *drv)
431 {
432 driver_unregister(&drv->driver);
433 }
434 EXPORT_SYMBOL_GPL(ntb_transport_unregister_client);
435
436 static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count,
437 loff_t *offp)
438 {
439 struct ntb_transport_qp *qp;
440 char *buf;
441 ssize_t ret, out_offset, out_count;
442
443 qp = filp->private_data;
444
445 if (!qp || !qp->link_is_up)
446 return 0;
447
448 out_count = 1000;
449
450 buf = kmalloc(out_count, GFP_KERNEL);
451 if (!buf)
452 return -ENOMEM;
453
454 out_offset = 0;
455 out_offset += snprintf(buf + out_offset, out_count - out_offset,
456 "\nNTB QP stats:\n\n");
457 out_offset += snprintf(buf + out_offset, out_count - out_offset,
458 "rx_bytes - \t%llu\n", qp->rx_bytes);
459 out_offset += snprintf(buf + out_offset, out_count - out_offset,
460 "rx_pkts - \t%llu\n", qp->rx_pkts);
461 out_offset += snprintf(buf + out_offset, out_count - out_offset,
462 "rx_memcpy - \t%llu\n", qp->rx_memcpy);
463 out_offset += snprintf(buf + out_offset, out_count - out_offset,
464 "rx_async - \t%llu\n", qp->rx_async);
465 out_offset += snprintf(buf + out_offset, out_count - out_offset,
466 "rx_ring_empty - %llu\n", qp->rx_ring_empty);
467 out_offset += snprintf(buf + out_offset, out_count - out_offset,
468 "rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
469 out_offset += snprintf(buf + out_offset, out_count - out_offset,
470 "rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
471 out_offset += snprintf(buf + out_offset, out_count - out_offset,
472 "rx_err_ver - \t%llu\n", qp->rx_err_ver);
473 out_offset += snprintf(buf + out_offset, out_count - out_offset,
474 "rx_buff - \t0x%p\n", qp->rx_buff);
475 out_offset += snprintf(buf + out_offset, out_count - out_offset,
476 "rx_index - \t%u\n", qp->rx_index);
477 out_offset += snprintf(buf + out_offset, out_count - out_offset,
478 "rx_max_entry - \t%u\n\n", qp->rx_max_entry);
479
480 out_offset += snprintf(buf + out_offset, out_count - out_offset,
481 "tx_bytes - \t%llu\n", qp->tx_bytes);
482 out_offset += snprintf(buf + out_offset, out_count - out_offset,
483 "tx_pkts - \t%llu\n", qp->tx_pkts);
484 out_offset += snprintf(buf + out_offset, out_count - out_offset,
485 "tx_memcpy - \t%llu\n", qp->tx_memcpy);
486 out_offset += snprintf(buf + out_offset, out_count - out_offset,
487 "tx_async - \t%llu\n", qp->tx_async);
488 out_offset += snprintf(buf + out_offset, out_count - out_offset,
489 "tx_ring_full - \t%llu\n", qp->tx_ring_full);
490 out_offset += snprintf(buf + out_offset, out_count - out_offset,
491 "tx_err_no_buf - %llu\n", qp->tx_err_no_buf);
492 out_offset += snprintf(buf + out_offset, out_count - out_offset,
493 "tx_mw - \t0x%p\n", qp->tx_mw);
494 out_offset += snprintf(buf + out_offset, out_count - out_offset,
495 "tx_index (H) - \t%u\n", qp->tx_index);
496 out_offset += snprintf(buf + out_offset, out_count - out_offset,
497 "RRI (T) - \t%u\n",
498 qp->remote_rx_info->entry);
499 out_offset += snprintf(buf + out_offset, out_count - out_offset,
500 "tx_max_entry - \t%u\n", qp->tx_max_entry);
501 out_offset += snprintf(buf + out_offset, out_count - out_offset,
502 "free tx - \t%u\n",
503 ntb_transport_tx_free_entry(qp));
504
505 out_offset += snprintf(buf + out_offset, out_count - out_offset,
506 "\n");
507 out_offset += snprintf(buf + out_offset, out_count - out_offset,
508 "Using TX DMA - \t%s\n",
509 qp->tx_dma_chan ? "Yes" : "No");
510 out_offset += snprintf(buf + out_offset, out_count - out_offset,
511 "Using RX DMA - \t%s\n",
512 qp->rx_dma_chan ? "Yes" : "No");
513 out_offset += snprintf(buf + out_offset, out_count - out_offset,
514 "QP Link - \t%s\n",
515 qp->link_is_up ? "Up" : "Down");
516 out_offset += snprintf(buf + out_offset, out_count - out_offset,
517 "\n");
518
519 if (out_offset > out_count)
520 out_offset = out_count;
521
522 ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
523 kfree(buf);
524 return ret;
525 }
526
527 static const struct file_operations ntb_qp_debugfs_stats = {
528 .owner = THIS_MODULE,
529 .open = simple_open,
530 .read = debugfs_read,
531 };
532
533 static void ntb_list_add(spinlock_t *lock, struct list_head *entry,
534 struct list_head *list)
535 {
536 unsigned long flags;
537
538 spin_lock_irqsave(lock, flags);
539 list_add_tail(entry, list);
540 spin_unlock_irqrestore(lock, flags);
541 }
542
543 static struct ntb_queue_entry *ntb_list_rm(spinlock_t *lock,
544 struct list_head *list)
545 {
546 struct ntb_queue_entry *entry;
547 unsigned long flags;
548
549 spin_lock_irqsave(lock, flags);
550 if (list_empty(list)) {
551 entry = NULL;
552 goto out;
553 }
554 entry = list_first_entry(list, struct ntb_queue_entry, entry);
555 list_del(&entry->entry);
556
557 out:
558 spin_unlock_irqrestore(lock, flags);
559
560 return entry;
561 }
562
563 static struct ntb_queue_entry *ntb_list_mv(spinlock_t *lock,
564 struct list_head *list,
565 struct list_head *to_list)
566 {
567 struct ntb_queue_entry *entry;
568 unsigned long flags;
569
570 spin_lock_irqsave(lock, flags);
571
572 if (list_empty(list)) {
573 entry = NULL;
574 } else {
575 entry = list_first_entry(list, struct ntb_queue_entry, entry);
576 list_move_tail(&entry->entry, to_list);
577 }
578
579 spin_unlock_irqrestore(lock, flags);
580
581 return entry;
582 }
583
584 static int ntb_transport_setup_qp_mw(struct ntb_transport_ctx *nt,
585 unsigned int qp_num)
586 {
587 struct ntb_transport_qp *qp = &nt->qp_vec[qp_num];
588 struct ntb_transport_mw *mw;
589 unsigned int rx_size, num_qps_mw;
590 unsigned int mw_num, mw_count, qp_count;
591 unsigned int i;
592
593 mw_count = nt->mw_count;
594 qp_count = nt->qp_count;
595
596 mw_num = QP_TO_MW(nt, qp_num);
597 mw = &nt->mw_vec[mw_num];
598
599 if (!mw->virt_addr)
600 return -ENOMEM;
601
602 if (qp_count % mw_count && mw_num + 1 < qp_count / mw_count)
603 num_qps_mw = qp_count / mw_count + 1;
604 else
605 num_qps_mw = qp_count / mw_count;
606
607 rx_size = (unsigned int)mw->xlat_size / num_qps_mw;
608 qp->rx_buff = mw->virt_addr + rx_size * (qp_num / mw_count);
609 rx_size -= sizeof(struct ntb_rx_info);
610
611 qp->remote_rx_info = qp->rx_buff + rx_size;
612
613 /* Due to housekeeping, there must be atleast 2 buffs */
614 qp->rx_max_frame = min(transport_mtu, rx_size / 2);
615 qp->rx_max_entry = rx_size / qp->rx_max_frame;
616 qp->rx_index = 0;
617
618 qp->remote_rx_info->entry = qp->rx_max_entry - 1;
619
620 /* setup the hdr offsets with 0's */
621 for (i = 0; i < qp->rx_max_entry; i++) {
622 void *offset = (qp->rx_buff + qp->rx_max_frame * (i + 1) -
623 sizeof(struct ntb_payload_header));
624 memset(offset, 0, sizeof(struct ntb_payload_header));
625 }
626
627 qp->rx_pkts = 0;
628 qp->tx_pkts = 0;
629 qp->tx_index = 0;
630
631 return 0;
632 }
633
634 static void ntb_free_mw(struct ntb_transport_ctx *nt, int num_mw)
635 {
636 struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
637 struct pci_dev *pdev = nt->ndev->pdev;
638
639 if (!mw->virt_addr)
640 return;
641
642 ntb_mw_clear_trans(nt->ndev, num_mw);
643 dma_free_coherent(&pdev->dev, mw->buff_size,
644 mw->virt_addr, mw->dma_addr);
645 mw->xlat_size = 0;
646 mw->buff_size = 0;
647 mw->virt_addr = NULL;
648 }
649
650 static int ntb_set_mw(struct ntb_transport_ctx *nt, int num_mw,
651 resource_size_t size)
652 {
653 struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
654 struct pci_dev *pdev = nt->ndev->pdev;
655 size_t xlat_size, buff_size;
656 int rc;
657
658 if (!size)
659 return -EINVAL;
660
661 xlat_size = round_up(size, mw->xlat_align_size);
662 buff_size = round_up(size, mw->xlat_align);
663
664 /* No need to re-setup */
665 if (mw->xlat_size == xlat_size)
666 return 0;
667
668 if (mw->buff_size)
669 ntb_free_mw(nt, num_mw);
670
671 /* Alloc memory for receiving data. Must be aligned */
672 mw->xlat_size = xlat_size;
673 mw->buff_size = buff_size;
674
675 mw->virt_addr = dma_alloc_coherent(&pdev->dev, buff_size,
676 &mw->dma_addr, GFP_KERNEL);
677 if (!mw->virt_addr) {
678 mw->xlat_size = 0;
679 mw->buff_size = 0;
680 dev_err(&pdev->dev, "Unable to alloc MW buff of size %zu\n",
681 buff_size);
682 return -ENOMEM;
683 }
684
685 /*
686 * we must ensure that the memory address allocated is BAR size
687 * aligned in order for the XLAT register to take the value. This
688 * is a requirement of the hardware. It is recommended to setup CMA
689 * for BAR sizes equal or greater than 4MB.
690 */
691 if (!IS_ALIGNED(mw->dma_addr, mw->xlat_align)) {
692 dev_err(&pdev->dev, "DMA memory %pad is not aligned\n",
693 &mw->dma_addr);
694 ntb_free_mw(nt, num_mw);
695 return -ENOMEM;
696 }
697
698 /* Notify HW the memory location of the receive buffer */
699 rc = ntb_mw_set_trans(nt->ndev, num_mw, mw->dma_addr, mw->xlat_size);
700 if (rc) {
701 dev_err(&pdev->dev, "Unable to set mw%d translation", num_mw);
702 ntb_free_mw(nt, num_mw);
703 return -EIO;
704 }
705
706 return 0;
707 }
708
709 static void ntb_qp_link_down_reset(struct ntb_transport_qp *qp)
710 {
711 qp->link_is_up = false;
712
713 qp->tx_index = 0;
714 qp->rx_index = 0;
715 qp->rx_bytes = 0;
716 qp->rx_pkts = 0;
717 qp->rx_ring_empty = 0;
718 qp->rx_err_no_buf = 0;
719 qp->rx_err_oflow = 0;
720 qp->rx_err_ver = 0;
721 qp->rx_memcpy = 0;
722 qp->rx_async = 0;
723 qp->tx_bytes = 0;
724 qp->tx_pkts = 0;
725 qp->tx_ring_full = 0;
726 qp->tx_err_no_buf = 0;
727 qp->tx_memcpy = 0;
728 qp->tx_async = 0;
729 }
730
731 static void ntb_qp_link_cleanup(struct ntb_transport_qp *qp)
732 {
733 struct ntb_transport_ctx *nt = qp->transport;
734 struct pci_dev *pdev = nt->ndev->pdev;
735
736 dev_info(&pdev->dev, "qp %d: Link Cleanup\n", qp->qp_num);
737
738 cancel_delayed_work_sync(&qp->link_work);
739 ntb_qp_link_down_reset(qp);
740
741 if (qp->event_handler)
742 qp->event_handler(qp->cb_data, qp->link_is_up);
743 }
744
745 static void ntb_qp_link_cleanup_work(struct work_struct *work)
746 {
747 struct ntb_transport_qp *qp = container_of(work,
748 struct ntb_transport_qp,
749 link_cleanup);
750 struct ntb_transport_ctx *nt = qp->transport;
751
752 ntb_qp_link_cleanup(qp);
753
754 if (nt->link_is_up)
755 schedule_delayed_work(&qp->link_work,
756 msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
757 }
758
759 static void ntb_qp_link_down(struct ntb_transport_qp *qp)
760 {
761 schedule_work(&qp->link_cleanup);
762 }
763
764 static void ntb_transport_link_cleanup(struct ntb_transport_ctx *nt)
765 {
766 struct ntb_transport_qp *qp;
767 u64 qp_bitmap_alloc;
768 int i;
769
770 qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
771
772 /* Pass along the info to any clients */
773 for (i = 0; i < nt->qp_count; i++)
774 if (qp_bitmap_alloc & BIT_ULL(i)) {
775 qp = &nt->qp_vec[i];
776 ntb_qp_link_cleanup(qp);
777 cancel_work_sync(&qp->link_cleanup);
778 cancel_delayed_work_sync(&qp->link_work);
779 }
780
781 if (!nt->link_is_up)
782 cancel_delayed_work_sync(&nt->link_work);
783
784 /* The scratchpad registers keep the values if the remote side
785 * goes down, blast them now to give them a sane value the next
786 * time they are accessed
787 */
788 for (i = 0; i < MAX_SPAD; i++)
789 ntb_spad_write(nt->ndev, i, 0);
790 }
791
792 static void ntb_transport_link_cleanup_work(struct work_struct *work)
793 {
794 struct ntb_transport_ctx *nt =
795 container_of(work, struct ntb_transport_ctx, link_cleanup);
796
797 ntb_transport_link_cleanup(nt);
798 }
799
800 static void ntb_transport_event_callback(void *data)
801 {
802 struct ntb_transport_ctx *nt = data;
803
804 if (ntb_link_is_up(nt->ndev, NULL, NULL) == 1)
805 schedule_delayed_work(&nt->link_work, 0);
806 else
807 schedule_work(&nt->link_cleanup);
808 }
809
810 static void ntb_transport_link_work(struct work_struct *work)
811 {
812 struct ntb_transport_ctx *nt =
813 container_of(work, struct ntb_transport_ctx, link_work.work);
814 struct ntb_dev *ndev = nt->ndev;
815 struct pci_dev *pdev = ndev->pdev;
816 resource_size_t size;
817 u32 val;
818 int rc, i, spad;
819
820 /* send the local info, in the opposite order of the way we read it */
821 for (i = 0; i < nt->mw_count; i++) {
822 size = nt->mw_vec[i].phys_size;
823
824 if (max_mw_size && size > max_mw_size)
825 size = max_mw_size;
826
827 spad = MW0_SZ_HIGH + (i * 2);
828 ntb_peer_spad_write(ndev, spad, upper_32_bits(size));
829
830 spad = MW0_SZ_LOW + (i * 2);
831 ntb_peer_spad_write(ndev, spad, lower_32_bits(size));
832 }
833
834 ntb_peer_spad_write(ndev, NUM_MWS, nt->mw_count);
835
836 ntb_peer_spad_write(ndev, NUM_QPS, nt->qp_count);
837
838 ntb_peer_spad_write(ndev, VERSION, NTB_TRANSPORT_VERSION);
839
840 /* Query the remote side for its info */
841 val = ntb_spad_read(ndev, VERSION);
842 dev_dbg(&pdev->dev, "Remote version = %d\n", val);
843 if (val != NTB_TRANSPORT_VERSION)
844 goto out;
845
846 val = ntb_spad_read(ndev, NUM_QPS);
847 dev_dbg(&pdev->dev, "Remote max number of qps = %d\n", val);
848 if (val != nt->qp_count)
849 goto out;
850
851 val = ntb_spad_read(ndev, NUM_MWS);
852 dev_dbg(&pdev->dev, "Remote number of mws = %d\n", val);
853 if (val != nt->mw_count)
854 goto out;
855
856 for (i = 0; i < nt->mw_count; i++) {
857 u64 val64;
858
859 val = ntb_spad_read(ndev, MW0_SZ_HIGH + (i * 2));
860 val64 = (u64)val << 32;
861
862 val = ntb_spad_read(ndev, MW0_SZ_LOW + (i * 2));
863 val64 |= val;
864
865 dev_dbg(&pdev->dev, "Remote MW%d size = %#llx\n", i, val64);
866
867 rc = ntb_set_mw(nt, i, val64);
868 if (rc)
869 goto out1;
870 }
871
872 nt->link_is_up = true;
873
874 for (i = 0; i < nt->qp_count; i++) {
875 struct ntb_transport_qp *qp = &nt->qp_vec[i];
876
877 ntb_transport_setup_qp_mw(nt, i);
878
879 if (qp->client_ready)
880 schedule_delayed_work(&qp->link_work, 0);
881 }
882
883 return;
884
885 out1:
886 for (i = 0; i < nt->mw_count; i++)
887 ntb_free_mw(nt, i);
888 out:
889 if (ntb_link_is_up(ndev, NULL, NULL) == 1)
890 schedule_delayed_work(&nt->link_work,
891 msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
892 }
893
894 static void ntb_qp_link_work(struct work_struct *work)
895 {
896 struct ntb_transport_qp *qp = container_of(work,
897 struct ntb_transport_qp,
898 link_work.work);
899 struct pci_dev *pdev = qp->ndev->pdev;
900 struct ntb_transport_ctx *nt = qp->transport;
901 int val;
902
903 WARN_ON(!nt->link_is_up);
904
905 val = ntb_spad_read(nt->ndev, QP_LINKS);
906
907 ntb_peer_spad_write(nt->ndev, QP_LINKS, val | BIT(qp->qp_num));
908
909 /* query remote spad for qp ready bits */
910 ntb_peer_spad_read(nt->ndev, QP_LINKS);
911 dev_dbg_ratelimited(&pdev->dev, "Remote QP link status = %x\n", val);
912
913 /* See if the remote side is up */
914 if (val & BIT(qp->qp_num)) {
915 dev_info(&pdev->dev, "qp %d: Link Up\n", qp->qp_num);
916 qp->link_is_up = true;
917
918 if (qp->event_handler)
919 qp->event_handler(qp->cb_data, qp->link_is_up);
920
921 tasklet_schedule(&qp->rxc_db_work);
922 } else if (nt->link_is_up)
923 schedule_delayed_work(&qp->link_work,
924 msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
925 }
926
927 static int ntb_transport_init_queue(struct ntb_transport_ctx *nt,
928 unsigned int qp_num)
929 {
930 struct ntb_transport_qp *qp;
931 phys_addr_t mw_base;
932 resource_size_t mw_size;
933 unsigned int num_qps_mw, tx_size;
934 unsigned int mw_num, mw_count, qp_count;
935 u64 qp_offset;
936
937 mw_count = nt->mw_count;
938 qp_count = nt->qp_count;
939
940 mw_num = QP_TO_MW(nt, qp_num);
941
942 qp = &nt->qp_vec[qp_num];
943 qp->qp_num = qp_num;
944 qp->transport = nt;
945 qp->ndev = nt->ndev;
946 qp->client_ready = false;
947 qp->event_handler = NULL;
948 ntb_qp_link_down_reset(qp);
949
950 if (qp_count % mw_count && mw_num + 1 < qp_count / mw_count)
951 num_qps_mw = qp_count / mw_count + 1;
952 else
953 num_qps_mw = qp_count / mw_count;
954
955 mw_base = nt->mw_vec[mw_num].phys_addr;
956 mw_size = nt->mw_vec[mw_num].phys_size;
957
958 tx_size = (unsigned int)mw_size / num_qps_mw;
959 qp_offset = tx_size * (qp_num / mw_count);
960
961 qp->tx_mw = nt->mw_vec[mw_num].vbase + qp_offset;
962 if (!qp->tx_mw)
963 return -EINVAL;
964
965 qp->tx_mw_phys = mw_base + qp_offset;
966 if (!qp->tx_mw_phys)
967 return -EINVAL;
968
969 tx_size -= sizeof(struct ntb_rx_info);
970 qp->rx_info = qp->tx_mw + tx_size;
971
972 /* Due to housekeeping, there must be atleast 2 buffs */
973 qp->tx_max_frame = min(transport_mtu, tx_size / 2);
974 qp->tx_max_entry = tx_size / qp->tx_max_frame;
975
976 if (nt->debugfs_node_dir) {
977 char debugfs_name[4];
978
979 snprintf(debugfs_name, 4, "qp%d", qp_num);
980 qp->debugfs_dir = debugfs_create_dir(debugfs_name,
981 nt->debugfs_node_dir);
982
983 qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR,
984 qp->debugfs_dir, qp,
985 &ntb_qp_debugfs_stats);
986 } else {
987 qp->debugfs_dir = NULL;
988 qp->debugfs_stats = NULL;
989 }
990
991 INIT_DELAYED_WORK(&qp->link_work, ntb_qp_link_work);
992 INIT_WORK(&qp->link_cleanup, ntb_qp_link_cleanup_work);
993
994 spin_lock_init(&qp->ntb_rx_q_lock);
995 spin_lock_init(&qp->ntb_tx_free_q_lock);
996
997 INIT_LIST_HEAD(&qp->rx_post_q);
998 INIT_LIST_HEAD(&qp->rx_pend_q);
999 INIT_LIST_HEAD(&qp->rx_free_q);
1000 INIT_LIST_HEAD(&qp->tx_free_q);
1001
1002 tasklet_init(&qp->rxc_db_work, ntb_transport_rxc_db,
1003 (unsigned long)qp);
1004
1005 return 0;
1006 }
1007
1008 static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev)
1009 {
1010 struct ntb_transport_ctx *nt;
1011 struct ntb_transport_mw *mw;
1012 unsigned int mw_count, qp_count;
1013 u64 qp_bitmap;
1014 int node;
1015 int rc, i;
1016
1017 if (ntb_db_is_unsafe(ndev))
1018 dev_dbg(&ndev->dev,
1019 "doorbell is unsafe, proceed anyway...\n");
1020 if (ntb_spad_is_unsafe(ndev))
1021 dev_dbg(&ndev->dev,
1022 "scratchpad is unsafe, proceed anyway...\n");
1023
1024 node = dev_to_node(&ndev->dev);
1025
1026 nt = kzalloc_node(sizeof(*nt), GFP_KERNEL, node);
1027 if (!nt)
1028 return -ENOMEM;
1029
1030 nt->ndev = ndev;
1031
1032 mw_count = ntb_mw_count(ndev);
1033
1034 nt->mw_count = mw_count;
1035
1036 nt->mw_vec = kzalloc_node(mw_count * sizeof(*nt->mw_vec),
1037 GFP_KERNEL, node);
1038 if (!nt->mw_vec) {
1039 rc = -ENOMEM;
1040 goto err;
1041 }
1042
1043 for (i = 0; i < mw_count; i++) {
1044 mw = &nt->mw_vec[i];
1045
1046 rc = ntb_mw_get_range(ndev, i, &mw->phys_addr, &mw->phys_size,
1047 &mw->xlat_align, &mw->xlat_align_size);
1048 if (rc)
1049 goto err1;
1050
1051 mw->vbase = ioremap_wc(mw->phys_addr, mw->phys_size);
1052 if (!mw->vbase) {
1053 rc = -ENOMEM;
1054 goto err1;
1055 }
1056
1057 mw->buff_size = 0;
1058 mw->xlat_size = 0;
1059 mw->virt_addr = NULL;
1060 mw->dma_addr = 0;
1061 }
1062
1063 qp_bitmap = ntb_db_valid_mask(ndev);
1064
1065 qp_count = ilog2(qp_bitmap);
1066 if (max_num_clients && max_num_clients < qp_count)
1067 qp_count = max_num_clients;
1068 else if (mw_count < qp_count)
1069 qp_count = mw_count;
1070
1071 qp_bitmap &= BIT_ULL(qp_count) - 1;
1072
1073 nt->qp_count = qp_count;
1074 nt->qp_bitmap = qp_bitmap;
1075 nt->qp_bitmap_free = qp_bitmap;
1076
1077 nt->qp_vec = kzalloc_node(qp_count * sizeof(*nt->qp_vec),
1078 GFP_KERNEL, node);
1079 if (!nt->qp_vec) {
1080 rc = -ENOMEM;
1081 goto err1;
1082 }
1083
1084 if (nt_debugfs_dir) {
1085 nt->debugfs_node_dir =
1086 debugfs_create_dir(pci_name(ndev->pdev),
1087 nt_debugfs_dir);
1088 }
1089
1090 for (i = 0; i < qp_count; i++) {
1091 rc = ntb_transport_init_queue(nt, i);
1092 if (rc)
1093 goto err2;
1094 }
1095
1096 INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work);
1097 INIT_WORK(&nt->link_cleanup, ntb_transport_link_cleanup_work);
1098
1099 rc = ntb_set_ctx(ndev, nt, &ntb_transport_ops);
1100 if (rc)
1101 goto err2;
1102
1103 INIT_LIST_HEAD(&nt->client_devs);
1104 rc = ntb_bus_init(nt);
1105 if (rc)
1106 goto err3;
1107
1108 nt->link_is_up = false;
1109 ntb_link_enable(ndev, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
1110 ntb_link_event(ndev);
1111
1112 return 0;
1113
1114 err3:
1115 ntb_clear_ctx(ndev);
1116 err2:
1117 kfree(nt->qp_vec);
1118 err1:
1119 while (i--) {
1120 mw = &nt->mw_vec[i];
1121 iounmap(mw->vbase);
1122 }
1123 kfree(nt->mw_vec);
1124 err:
1125 kfree(nt);
1126 return rc;
1127 }
1128
1129 static void ntb_transport_free(struct ntb_client *self, struct ntb_dev *ndev)
1130 {
1131 struct ntb_transport_ctx *nt = ndev->ctx;
1132 struct ntb_transport_qp *qp;
1133 u64 qp_bitmap_alloc;
1134 int i;
1135
1136 ntb_transport_link_cleanup(nt);
1137 cancel_work_sync(&nt->link_cleanup);
1138 cancel_delayed_work_sync(&nt->link_work);
1139
1140 qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
1141
1142 /* verify that all the qp's are freed */
1143 for (i = 0; i < nt->qp_count; i++) {
1144 qp = &nt->qp_vec[i];
1145 if (qp_bitmap_alloc & BIT_ULL(i))
1146 ntb_transport_free_queue(qp);
1147 debugfs_remove_recursive(qp->debugfs_dir);
1148 }
1149
1150 ntb_link_disable(ndev);
1151 ntb_clear_ctx(ndev);
1152
1153 ntb_bus_remove(nt);
1154
1155 for (i = nt->mw_count; i--; ) {
1156 ntb_free_mw(nt, i);
1157 iounmap(nt->mw_vec[i].vbase);
1158 }
1159
1160 kfree(nt->qp_vec);
1161 kfree(nt->mw_vec);
1162 kfree(nt);
1163 }
1164
1165 static void ntb_complete_rxc(struct ntb_transport_qp *qp)
1166 {
1167 struct ntb_queue_entry *entry;
1168 void *cb_data;
1169 unsigned int len;
1170 unsigned long irqflags;
1171
1172 spin_lock_irqsave(&qp->ntb_rx_q_lock, irqflags);
1173
1174 while (!list_empty(&qp->rx_post_q)) {
1175 entry = list_first_entry(&qp->rx_post_q,
1176 struct ntb_queue_entry, entry);
1177 if (!(entry->flags & DESC_DONE_FLAG))
1178 break;
1179
1180 entry->rx_hdr->flags = 0;
1181 iowrite32(entry->index, &qp->rx_info->entry);
1182
1183 cb_data = entry->cb_data;
1184 len = entry->len;
1185
1186 list_move_tail(&entry->entry, &qp->rx_free_q);
1187
1188 spin_unlock_irqrestore(&qp->ntb_rx_q_lock, irqflags);
1189
1190 if (qp->rx_handler && qp->client_ready)
1191 qp->rx_handler(qp, qp->cb_data, cb_data, len);
1192
1193 spin_lock_irqsave(&qp->ntb_rx_q_lock, irqflags);
1194 }
1195
1196 spin_unlock_irqrestore(&qp->ntb_rx_q_lock, irqflags);
1197 }
1198
1199 static void ntb_rx_copy_callback(void *data)
1200 {
1201 struct ntb_queue_entry *entry = data;
1202
1203 entry->flags |= DESC_DONE_FLAG;
1204
1205 ntb_complete_rxc(entry->qp);
1206 }
1207
1208 static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void *offset)
1209 {
1210 void *buf = entry->buf;
1211 size_t len = entry->len;
1212
1213 memcpy(buf, offset, len);
1214
1215 /* Ensure that the data is fully copied out before clearing the flag */
1216 wmb();
1217
1218 ntb_rx_copy_callback(entry);
1219 }
1220
1221 static void ntb_async_rx(struct ntb_queue_entry *entry, void *offset)
1222 {
1223 struct dma_async_tx_descriptor *txd;
1224 struct ntb_transport_qp *qp = entry->qp;
1225 struct dma_chan *chan = qp->rx_dma_chan;
1226 struct dma_device *device;
1227 size_t pay_off, buff_off, len;
1228 struct dmaengine_unmap_data *unmap;
1229 dma_cookie_t cookie;
1230 void *buf = entry->buf;
1231
1232 len = entry->len;
1233
1234 if (!chan)
1235 goto err;
1236
1237 if (len < copy_bytes)
1238 goto err;
1239
1240 device = chan->device;
1241 pay_off = (size_t)offset & ~PAGE_MASK;
1242 buff_off = (size_t)buf & ~PAGE_MASK;
1243
1244 if (!is_dma_copy_aligned(device, pay_off, buff_off, len))
1245 goto err;
1246
1247 unmap = dmaengine_get_unmap_data(device->dev, 2, GFP_NOWAIT);
1248 if (!unmap)
1249 goto err;
1250
1251 unmap->len = len;
1252 unmap->addr[0] = dma_map_page(device->dev, virt_to_page(offset),
1253 pay_off, len, DMA_TO_DEVICE);
1254 if (dma_mapping_error(device->dev, unmap->addr[0]))
1255 goto err_get_unmap;
1256
1257 unmap->to_cnt = 1;
1258
1259 unmap->addr[1] = dma_map_page(device->dev, virt_to_page(buf),
1260 buff_off, len, DMA_FROM_DEVICE);
1261 if (dma_mapping_error(device->dev, unmap->addr[1]))
1262 goto err_get_unmap;
1263
1264 unmap->from_cnt = 1;
1265
1266 txd = device->device_prep_dma_memcpy(chan, unmap->addr[1],
1267 unmap->addr[0], len,
1268 DMA_PREP_INTERRUPT);
1269 if (!txd)
1270 goto err_get_unmap;
1271
1272 txd->callback = ntb_rx_copy_callback;
1273 txd->callback_param = entry;
1274 dma_set_unmap(txd, unmap);
1275
1276 cookie = dmaengine_submit(txd);
1277 if (dma_submit_error(cookie))
1278 goto err_set_unmap;
1279
1280 dmaengine_unmap_put(unmap);
1281
1282 qp->last_cookie = cookie;
1283
1284 qp->rx_async++;
1285
1286 return;
1287
1288 err_set_unmap:
1289 dmaengine_unmap_put(unmap);
1290 err_get_unmap:
1291 dmaengine_unmap_put(unmap);
1292 err:
1293 ntb_memcpy_rx(entry, offset);
1294 qp->rx_memcpy++;
1295 }
1296
1297 static int ntb_process_rxc(struct ntb_transport_qp *qp)
1298 {
1299 struct ntb_payload_header *hdr;
1300 struct ntb_queue_entry *entry;
1301 void *offset;
1302
1303 offset = qp->rx_buff + qp->rx_max_frame * qp->rx_index;
1304 hdr = offset + qp->rx_max_frame - sizeof(struct ntb_payload_header);
1305
1306 dev_dbg(&qp->ndev->pdev->dev, "qp %d: RX ver %u len %d flags %x\n",
1307 qp->qp_num, hdr->ver, hdr->len, hdr->flags);
1308
1309 if (!(hdr->flags & DESC_DONE_FLAG)) {
1310 dev_dbg(&qp->ndev->pdev->dev, "done flag not set\n");
1311 qp->rx_ring_empty++;
1312 return -EAGAIN;
1313 }
1314
1315 if (hdr->flags & LINK_DOWN_FLAG) {
1316 dev_dbg(&qp->ndev->pdev->dev, "link down flag set\n");
1317 ntb_qp_link_down(qp);
1318 hdr->flags = 0;
1319 return -EAGAIN;
1320 }
1321
1322 if (hdr->ver != (u32)qp->rx_pkts) {
1323 dev_dbg(&qp->ndev->pdev->dev,
1324 "version mismatch, expected %llu - got %u\n",
1325 qp->rx_pkts, hdr->ver);
1326 qp->rx_err_ver++;
1327 return -EIO;
1328 }
1329
1330 entry = ntb_list_mv(&qp->ntb_rx_q_lock, &qp->rx_pend_q, &qp->rx_post_q);
1331 if (!entry) {
1332 dev_dbg(&qp->ndev->pdev->dev, "no receive buffer\n");
1333 qp->rx_err_no_buf++;
1334 return -EAGAIN;
1335 }
1336
1337 entry->rx_hdr = hdr;
1338 entry->index = qp->rx_index;
1339
1340 if (hdr->len > entry->len) {
1341 dev_dbg(&qp->ndev->pdev->dev,
1342 "receive buffer overflow! Wanted %d got %d\n",
1343 hdr->len, entry->len);
1344 qp->rx_err_oflow++;
1345
1346 entry->len = -EIO;
1347 entry->flags |= DESC_DONE_FLAG;
1348
1349 ntb_complete_rxc(qp);
1350 } else {
1351 dev_dbg(&qp->ndev->pdev->dev,
1352 "RX OK index %u ver %u size %d into buf size %d\n",
1353 qp->rx_index, hdr->ver, hdr->len, entry->len);
1354
1355 qp->rx_bytes += hdr->len;
1356 qp->rx_pkts++;
1357
1358 entry->len = hdr->len;
1359
1360 ntb_async_rx(entry, offset);
1361 }
1362
1363 qp->rx_index++;
1364 qp->rx_index %= qp->rx_max_entry;
1365
1366 return 0;
1367 }
1368
1369 static void ntb_transport_rxc_db(unsigned long data)
1370 {
1371 struct ntb_transport_qp *qp = (void *)data;
1372 int rc, i;
1373
1374 dev_dbg(&qp->ndev->pdev->dev, "%s: doorbell %d received\n",
1375 __func__, qp->qp_num);
1376
1377 /* Limit the number of packets processed in a single interrupt to
1378 * provide fairness to others
1379 */
1380 for (i = 0; i < qp->rx_max_entry; i++) {
1381 rc = ntb_process_rxc(qp);
1382 if (rc)
1383 break;
1384 }
1385
1386 if (i && qp->rx_dma_chan)
1387 dma_async_issue_pending(qp->rx_dma_chan);
1388
1389 if (i == qp->rx_max_entry) {
1390 /* there is more work to do */
1391 tasklet_schedule(&qp->rxc_db_work);
1392 } else if (ntb_db_read(qp->ndev) & BIT_ULL(qp->qp_num)) {
1393 /* the doorbell bit is set: clear it */
1394 ntb_db_clear(qp->ndev, BIT_ULL(qp->qp_num));
1395 /* ntb_db_read ensures ntb_db_clear write is committed */
1396 ntb_db_read(qp->ndev);
1397
1398 /* an interrupt may have arrived between finishing
1399 * ntb_process_rxc and clearing the doorbell bit:
1400 * there might be some more work to do.
1401 */
1402 tasklet_schedule(&qp->rxc_db_work);
1403 }
1404 }
1405
1406 static void ntb_tx_copy_callback(void *data)
1407 {
1408 struct ntb_queue_entry *entry = data;
1409 struct ntb_transport_qp *qp = entry->qp;
1410 struct ntb_payload_header __iomem *hdr = entry->tx_hdr;
1411
1412 iowrite32(entry->flags | DESC_DONE_FLAG, &hdr->flags);
1413
1414 ntb_peer_db_set(qp->ndev, BIT_ULL(qp->qp_num));
1415
1416 /* The entry length can only be zero if the packet is intended to be a
1417 * "link down" or similar. Since no payload is being sent in these
1418 * cases, there is nothing to add to the completion queue.
1419 */
1420 if (entry->len > 0) {
1421 qp->tx_bytes += entry->len;
1422
1423 if (qp->tx_handler)
1424 qp->tx_handler(qp, qp->cb_data, entry->cb_data,
1425 entry->len);
1426 }
1427
1428 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q);
1429 }
1430
1431 static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset)
1432 {
1433 #ifdef ARCH_HAS_NOCACHE_UACCESS
1434 /*
1435 * Using non-temporal mov to improve performance on non-cached
1436 * writes, even though we aren't actually copying from user space.
1437 */
1438 __copy_from_user_inatomic_nocache(offset, entry->buf, entry->len);
1439 #else
1440 memcpy_toio(offset, entry->buf, entry->len);
1441 #endif
1442
1443 /* Ensure that the data is fully copied out before setting the flags */
1444 wmb();
1445
1446 ntb_tx_copy_callback(entry);
1447 }
1448
1449 static void ntb_async_tx(struct ntb_transport_qp *qp,
1450 struct ntb_queue_entry *entry)
1451 {
1452 struct ntb_payload_header __iomem *hdr;
1453 struct dma_async_tx_descriptor *txd;
1454 struct dma_chan *chan = qp->tx_dma_chan;
1455 struct dma_device *device;
1456 size_t dest_off, buff_off;
1457 struct dmaengine_unmap_data *unmap;
1458 dma_addr_t dest;
1459 dma_cookie_t cookie;
1460 void __iomem *offset;
1461 size_t len = entry->len;
1462 void *buf = entry->buf;
1463
1464 offset = qp->tx_mw + qp->tx_max_frame * qp->tx_index;
1465 hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
1466 entry->tx_hdr = hdr;
1467
1468 iowrite32(entry->len, &hdr->len);
1469 iowrite32((u32)qp->tx_pkts, &hdr->ver);
1470
1471 if (!chan)
1472 goto err;
1473
1474 if (len < copy_bytes)
1475 goto err;
1476
1477 device = chan->device;
1478 dest = qp->tx_mw_phys + qp->tx_max_frame * qp->tx_index;
1479 buff_off = (size_t)buf & ~PAGE_MASK;
1480 dest_off = (size_t)dest & ~PAGE_MASK;
1481
1482 if (!is_dma_copy_aligned(device, buff_off, dest_off, len))
1483 goto err;
1484
1485 unmap = dmaengine_get_unmap_data(device->dev, 1, GFP_NOWAIT);
1486 if (!unmap)
1487 goto err;
1488
1489 unmap->len = len;
1490 unmap->addr[0] = dma_map_page(device->dev, virt_to_page(buf),
1491 buff_off, len, DMA_TO_DEVICE);
1492 if (dma_mapping_error(device->dev, unmap->addr[0]))
1493 goto err_get_unmap;
1494
1495 unmap->to_cnt = 1;
1496
1497 txd = device->device_prep_dma_memcpy(chan, dest, unmap->addr[0], len,
1498 DMA_PREP_INTERRUPT);
1499 if (!txd)
1500 goto err_get_unmap;
1501
1502 txd->callback = ntb_tx_copy_callback;
1503 txd->callback_param = entry;
1504 dma_set_unmap(txd, unmap);
1505
1506 cookie = dmaengine_submit(txd);
1507 if (dma_submit_error(cookie))
1508 goto err_set_unmap;
1509
1510 dmaengine_unmap_put(unmap);
1511
1512 dma_async_issue_pending(chan);
1513 qp->tx_async++;
1514
1515 return;
1516 err_set_unmap:
1517 dmaengine_unmap_put(unmap);
1518 err_get_unmap:
1519 dmaengine_unmap_put(unmap);
1520 err:
1521 ntb_memcpy_tx(entry, offset);
1522 qp->tx_memcpy++;
1523 }
1524
1525 static int ntb_process_tx(struct ntb_transport_qp *qp,
1526 struct ntb_queue_entry *entry)
1527 {
1528 if (qp->tx_index == qp->remote_rx_info->entry) {
1529 qp->tx_ring_full++;
1530 return -EAGAIN;
1531 }
1532
1533 if (entry->len > qp->tx_max_frame - sizeof(struct ntb_payload_header)) {
1534 if (qp->tx_handler)
1535 qp->tx_handler(qp->cb_data, qp, NULL, -EIO);
1536
1537 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1538 &qp->tx_free_q);
1539 return 0;
1540 }
1541
1542 ntb_async_tx(qp, entry);
1543
1544 qp->tx_index++;
1545 qp->tx_index %= qp->tx_max_entry;
1546
1547 qp->tx_pkts++;
1548
1549 return 0;
1550 }
1551
1552 static void ntb_send_link_down(struct ntb_transport_qp *qp)
1553 {
1554 struct pci_dev *pdev = qp->ndev->pdev;
1555 struct ntb_queue_entry *entry;
1556 int i, rc;
1557
1558 if (!qp->link_is_up)
1559 return;
1560
1561 dev_info(&pdev->dev, "qp %d: Send Link Down\n", qp->qp_num);
1562
1563 for (i = 0; i < NTB_LINK_DOWN_TIMEOUT; i++) {
1564 entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1565 if (entry)
1566 break;
1567 msleep(100);
1568 }
1569
1570 if (!entry)
1571 return;
1572
1573 entry->cb_data = NULL;
1574 entry->buf = NULL;
1575 entry->len = 0;
1576 entry->flags = LINK_DOWN_FLAG;
1577
1578 rc = ntb_process_tx(qp, entry);
1579 if (rc)
1580 dev_err(&pdev->dev, "ntb: QP%d unable to send linkdown msg\n",
1581 qp->qp_num);
1582
1583 ntb_qp_link_down_reset(qp);
1584 }
1585
1586 static bool ntb_dma_filter_fn(struct dma_chan *chan, void *node)
1587 {
1588 return dev_to_node(&chan->dev->device) == (int)(unsigned long)node;
1589 }
1590
1591 /**
1592 * ntb_transport_create_queue - Create a new NTB transport layer queue
1593 * @rx_handler: receive callback function
1594 * @tx_handler: transmit callback function
1595 * @event_handler: event callback function
1596 *
1597 * Create a new NTB transport layer queue and provide the queue with a callback
1598 * routine for both transmit and receive. The receive callback routine will be
1599 * used to pass up data when the transport has received it on the queue. The
1600 * transmit callback routine will be called when the transport has completed the
1601 * transmission of the data on the queue and the data is ready to be freed.
1602 *
1603 * RETURNS: pointer to newly created ntb_queue, NULL on error.
1604 */
1605 struct ntb_transport_qp *
1606 ntb_transport_create_queue(void *data, struct device *client_dev,
1607 const struct ntb_queue_handlers *handlers)
1608 {
1609 struct ntb_dev *ndev;
1610 struct pci_dev *pdev;
1611 struct ntb_transport_ctx *nt;
1612 struct ntb_queue_entry *entry;
1613 struct ntb_transport_qp *qp;
1614 u64 qp_bit;
1615 unsigned int free_queue;
1616 dma_cap_mask_t dma_mask;
1617 int node;
1618 int i;
1619
1620 ndev = dev_ntb(client_dev->parent);
1621 pdev = ndev->pdev;
1622 nt = ndev->ctx;
1623
1624 node = dev_to_node(&ndev->dev);
1625
1626 free_queue = ffs(nt->qp_bitmap);
1627 if (!free_queue)
1628 goto err;
1629
1630 /* decrement free_queue to make it zero based */
1631 free_queue--;
1632
1633 qp = &nt->qp_vec[free_queue];
1634 qp_bit = BIT_ULL(qp->qp_num);
1635
1636 nt->qp_bitmap_free &= ~qp_bit;
1637
1638 qp->cb_data = data;
1639 qp->rx_handler = handlers->rx_handler;
1640 qp->tx_handler = handlers->tx_handler;
1641 qp->event_handler = handlers->event_handler;
1642
1643 dma_cap_zero(dma_mask);
1644 dma_cap_set(DMA_MEMCPY, dma_mask);
1645
1646 if (use_dma) {
1647 qp->tx_dma_chan =
1648 dma_request_channel(dma_mask, ntb_dma_filter_fn,
1649 (void *)(unsigned long)node);
1650 if (!qp->tx_dma_chan)
1651 dev_info(&pdev->dev, "Unable to allocate TX DMA channel\n");
1652
1653 qp->rx_dma_chan =
1654 dma_request_channel(dma_mask, ntb_dma_filter_fn,
1655 (void *)(unsigned long)node);
1656 if (!qp->rx_dma_chan)
1657 dev_info(&pdev->dev, "Unable to allocate RX DMA channel\n");
1658 } else {
1659 qp->tx_dma_chan = NULL;
1660 qp->rx_dma_chan = NULL;
1661 }
1662
1663 dev_dbg(&pdev->dev, "Using %s memcpy for TX\n",
1664 qp->tx_dma_chan ? "DMA" : "CPU");
1665
1666 dev_dbg(&pdev->dev, "Using %s memcpy for RX\n",
1667 qp->rx_dma_chan ? "DMA" : "CPU");
1668
1669 for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
1670 entry = kzalloc_node(sizeof(*entry), GFP_ATOMIC, node);
1671 if (!entry)
1672 goto err1;
1673
1674 entry->qp = qp;
1675 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry,
1676 &qp->rx_free_q);
1677 }
1678
1679 for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
1680 entry = kzalloc_node(sizeof(*entry), GFP_ATOMIC, node);
1681 if (!entry)
1682 goto err2;
1683
1684 entry->qp = qp;
1685 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1686 &qp->tx_free_q);
1687 }
1688
1689 ntb_db_clear(qp->ndev, qp_bit);
1690 ntb_db_clear_mask(qp->ndev, qp_bit);
1691
1692 dev_info(&pdev->dev, "NTB Transport QP %d created\n", qp->qp_num);
1693
1694 return qp;
1695
1696 err2:
1697 while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1698 kfree(entry);
1699 err1:
1700 while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
1701 kfree(entry);
1702 if (qp->tx_dma_chan)
1703 dma_release_channel(qp->tx_dma_chan);
1704 if (qp->rx_dma_chan)
1705 dma_release_channel(qp->rx_dma_chan);
1706 nt->qp_bitmap_free |= qp_bit;
1707 err:
1708 return NULL;
1709 }
1710 EXPORT_SYMBOL_GPL(ntb_transport_create_queue);
1711
1712 /**
1713 * ntb_transport_free_queue - Frees NTB transport queue
1714 * @qp: NTB queue to be freed
1715 *
1716 * Frees NTB transport queue
1717 */
1718 void ntb_transport_free_queue(struct ntb_transport_qp *qp)
1719 {
1720 struct pci_dev *pdev;
1721 struct ntb_queue_entry *entry;
1722 u64 qp_bit;
1723
1724 if (!qp)
1725 return;
1726
1727 pdev = qp->ndev->pdev;
1728
1729 if (qp->tx_dma_chan) {
1730 struct dma_chan *chan = qp->tx_dma_chan;
1731 /* Putting the dma_chan to NULL will force any new traffic to be
1732 * processed by the CPU instead of the DAM engine
1733 */
1734 qp->tx_dma_chan = NULL;
1735
1736 /* Try to be nice and wait for any queued DMA engine
1737 * transactions to process before smashing it with a rock
1738 */
1739 dma_sync_wait(chan, qp->last_cookie);
1740 dmaengine_terminate_all(chan);
1741 dma_release_channel(chan);
1742 }
1743
1744 if (qp->rx_dma_chan) {
1745 struct dma_chan *chan = qp->rx_dma_chan;
1746 /* Putting the dma_chan to NULL will force any new traffic to be
1747 * processed by the CPU instead of the DAM engine
1748 */
1749 qp->rx_dma_chan = NULL;
1750
1751 /* Try to be nice and wait for any queued DMA engine
1752 * transactions to process before smashing it with a rock
1753 */
1754 dma_sync_wait(chan, qp->last_cookie);
1755 dmaengine_terminate_all(chan);
1756 dma_release_channel(chan);
1757 }
1758
1759 qp_bit = BIT_ULL(qp->qp_num);
1760
1761 ntb_db_set_mask(qp->ndev, qp_bit);
1762 tasklet_disable(&qp->rxc_db_work);
1763
1764 cancel_delayed_work_sync(&qp->link_work);
1765
1766 qp->cb_data = NULL;
1767 qp->rx_handler = NULL;
1768 qp->tx_handler = NULL;
1769 qp->event_handler = NULL;
1770
1771 while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
1772 kfree(entry);
1773
1774 while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_pend_q))) {
1775 dev_warn(&pdev->dev, "Freeing item from non-empty rx_pend_q\n");
1776 kfree(entry);
1777 }
1778
1779 while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_post_q))) {
1780 dev_warn(&pdev->dev, "Freeing item from non-empty rx_post_q\n");
1781 kfree(entry);
1782 }
1783
1784 while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1785 kfree(entry);
1786
1787 qp->transport->qp_bitmap_free |= qp_bit;
1788
1789 dev_info(&pdev->dev, "NTB Transport QP %d freed\n", qp->qp_num);
1790 }
1791 EXPORT_SYMBOL_GPL(ntb_transport_free_queue);
1792
1793 /**
1794 * ntb_transport_rx_remove - Dequeues enqueued rx packet
1795 * @qp: NTB queue to be freed
1796 * @len: pointer to variable to write enqueued buffers length
1797 *
1798 * Dequeues unused buffers from receive queue. Should only be used during
1799 * shutdown of qp.
1800 *
1801 * RETURNS: NULL error value on error, or void* for success.
1802 */
1803 void *ntb_transport_rx_remove(struct ntb_transport_qp *qp, unsigned int *len)
1804 {
1805 struct ntb_queue_entry *entry;
1806 void *buf;
1807
1808 if (!qp || qp->client_ready)
1809 return NULL;
1810
1811 entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_pend_q);
1812 if (!entry)
1813 return NULL;
1814
1815 buf = entry->cb_data;
1816 *len = entry->len;
1817
1818 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_free_q);
1819
1820 return buf;
1821 }
1822 EXPORT_SYMBOL_GPL(ntb_transport_rx_remove);
1823
1824 /**
1825 * ntb_transport_rx_enqueue - Enqueue a new NTB queue entry
1826 * @qp: NTB transport layer queue the entry is to be enqueued on
1827 * @cb: per buffer pointer for callback function to use
1828 * @data: pointer to data buffer that incoming packets will be copied into
1829 * @len: length of the data buffer
1830 *
1831 * Enqueue a new receive buffer onto the transport queue into which a NTB
1832 * payload can be received into.
1833 *
1834 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
1835 */
1836 int ntb_transport_rx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
1837 unsigned int len)
1838 {
1839 struct ntb_queue_entry *entry;
1840
1841 if (!qp)
1842 return -EINVAL;
1843
1844 entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q);
1845 if (!entry)
1846 return -ENOMEM;
1847
1848 entry->cb_data = cb;
1849 entry->buf = data;
1850 entry->len = len;
1851 entry->flags = 0;
1852
1853 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_pend_q);
1854
1855 tasklet_schedule(&qp->rxc_db_work);
1856
1857 return 0;
1858 }
1859 EXPORT_SYMBOL_GPL(ntb_transport_rx_enqueue);
1860
1861 /**
1862 * ntb_transport_tx_enqueue - Enqueue a new NTB queue entry
1863 * @qp: NTB transport layer queue the entry is to be enqueued on
1864 * @cb: per buffer pointer for callback function to use
1865 * @data: pointer to data buffer that will be sent
1866 * @len: length of the data buffer
1867 *
1868 * Enqueue a new transmit buffer onto the transport queue from which a NTB
1869 * payload will be transmitted. This assumes that a lock is being held to
1870 * serialize access to the qp.
1871 *
1872 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
1873 */
1874 int ntb_transport_tx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
1875 unsigned int len)
1876 {
1877 struct ntb_queue_entry *entry;
1878 int rc;
1879
1880 if (!qp || !qp->link_is_up || !len)
1881 return -EINVAL;
1882
1883 entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1884 if (!entry) {
1885 qp->tx_err_no_buf++;
1886 return -EBUSY;
1887 }
1888
1889 entry->cb_data = cb;
1890 entry->buf = data;
1891 entry->len = len;
1892 entry->flags = 0;
1893
1894 rc = ntb_process_tx(qp, entry);
1895 if (rc)
1896 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1897 &qp->tx_free_q);
1898
1899 return rc;
1900 }
1901 EXPORT_SYMBOL_GPL(ntb_transport_tx_enqueue);
1902
1903 /**
1904 * ntb_transport_link_up - Notify NTB transport of client readiness to use queue
1905 * @qp: NTB transport layer queue to be enabled
1906 *
1907 * Notify NTB transport layer of client readiness to use queue
1908 */
1909 void ntb_transport_link_up(struct ntb_transport_qp *qp)
1910 {
1911 if (!qp)
1912 return;
1913
1914 qp->client_ready = true;
1915
1916 if (qp->transport->link_is_up)
1917 schedule_delayed_work(&qp->link_work, 0);
1918 }
1919 EXPORT_SYMBOL_GPL(ntb_transport_link_up);
1920
1921 /**
1922 * ntb_transport_link_down - Notify NTB transport to no longer enqueue data
1923 * @qp: NTB transport layer queue to be disabled
1924 *
1925 * Notify NTB transport layer of client's desire to no longer receive data on
1926 * transport queue specified. It is the client's responsibility to ensure all
1927 * entries on queue are purged or otherwise handled appropriately.
1928 */
1929 void ntb_transport_link_down(struct ntb_transport_qp *qp)
1930 {
1931 int val;
1932
1933 if (!qp)
1934 return;
1935
1936 qp->client_ready = false;
1937
1938 val = ntb_spad_read(qp->ndev, QP_LINKS);
1939
1940 ntb_peer_spad_write(qp->ndev, QP_LINKS,
1941 val & ~BIT(qp->qp_num));
1942
1943 if (qp->link_is_up)
1944 ntb_send_link_down(qp);
1945 else
1946 cancel_delayed_work_sync(&qp->link_work);
1947 }
1948 EXPORT_SYMBOL_GPL(ntb_transport_link_down);
1949
1950 /**
1951 * ntb_transport_link_query - Query transport link state
1952 * @qp: NTB transport layer queue to be queried
1953 *
1954 * Query connectivity to the remote system of the NTB transport queue
1955 *
1956 * RETURNS: true for link up or false for link down
1957 */
1958 bool ntb_transport_link_query(struct ntb_transport_qp *qp)
1959 {
1960 if (!qp)
1961 return false;
1962
1963 return qp->link_is_up;
1964 }
1965 EXPORT_SYMBOL_GPL(ntb_transport_link_query);
1966
1967 /**
1968 * ntb_transport_qp_num - Query the qp number
1969 * @qp: NTB transport layer queue to be queried
1970 *
1971 * Query qp number of the NTB transport queue
1972 *
1973 * RETURNS: a zero based number specifying the qp number
1974 */
1975 unsigned char ntb_transport_qp_num(struct ntb_transport_qp *qp)
1976 {
1977 if (!qp)
1978 return 0;
1979
1980 return qp->qp_num;
1981 }
1982 EXPORT_SYMBOL_GPL(ntb_transport_qp_num);
1983
1984 /**
1985 * ntb_transport_max_size - Query the max payload size of a qp
1986 * @qp: NTB transport layer queue to be queried
1987 *
1988 * Query the maximum payload size permissible on the given qp
1989 *
1990 * RETURNS: the max payload size of a qp
1991 */
1992 unsigned int ntb_transport_max_size(struct ntb_transport_qp *qp)
1993 {
1994 unsigned int max_size;
1995 unsigned int copy_align;
1996 struct dma_chan *rx_chan, *tx_chan;
1997
1998 if (!qp)
1999 return 0;
2000
2001 rx_chan = qp->rx_dma_chan;
2002 tx_chan = qp->tx_dma_chan;
2003
2004 copy_align = max(rx_chan ? rx_chan->device->copy_align : 0,
2005 tx_chan ? tx_chan->device->copy_align : 0);
2006
2007 /* If DMA engine usage is possible, try to find the max size for that */
2008 max_size = qp->tx_max_frame - sizeof(struct ntb_payload_header);
2009 max_size = round_down(max_size, 1 << copy_align);
2010
2011 return max_size;
2012 }
2013 EXPORT_SYMBOL_GPL(ntb_transport_max_size);
2014
2015 unsigned int ntb_transport_tx_free_entry(struct ntb_transport_qp *qp)
2016 {
2017 unsigned int head = qp->tx_index;
2018 unsigned int tail = qp->remote_rx_info->entry;
2019
2020 return tail > head ? tail - head : qp->tx_max_entry + tail - head;
2021 }
2022 EXPORT_SYMBOL_GPL(ntb_transport_tx_free_entry);
2023
2024 static void ntb_transport_doorbell_callback(void *data, int vector)
2025 {
2026 struct ntb_transport_ctx *nt = data;
2027 struct ntb_transport_qp *qp;
2028 u64 db_bits;
2029 unsigned int qp_num;
2030
2031 db_bits = (nt->qp_bitmap & ~nt->qp_bitmap_free &
2032 ntb_db_vector_mask(nt->ndev, vector));
2033
2034 while (db_bits) {
2035 qp_num = __ffs(db_bits);
2036 qp = &nt->qp_vec[qp_num];
2037
2038 tasklet_schedule(&qp->rxc_db_work);
2039
2040 db_bits &= ~BIT_ULL(qp_num);
2041 }
2042 }
2043
2044 static const struct ntb_ctx_ops ntb_transport_ops = {
2045 .link_event = ntb_transport_event_callback,
2046 .db_event = ntb_transport_doorbell_callback,
2047 };
2048
2049 static struct ntb_client ntb_transport_client = {
2050 .ops = {
2051 .probe = ntb_transport_probe,
2052 .remove = ntb_transport_free,
2053 },
2054 };
2055
2056 static int __init ntb_transport_init(void)
2057 {
2058 int rc;
2059
2060 pr_info("%s, version %s\n", NTB_TRANSPORT_DESC, NTB_TRANSPORT_VER);
2061
2062 if (debugfs_initialized())
2063 nt_debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
2064
2065 rc = bus_register(&ntb_transport_bus);
2066 if (rc)
2067 goto err_bus;
2068
2069 rc = ntb_register_client(&ntb_transport_client);
2070 if (rc)
2071 goto err_client;
2072
2073 return 0;
2074
2075 err_client:
2076 bus_unregister(&ntb_transport_bus);
2077 err_bus:
2078 debugfs_remove_recursive(nt_debugfs_dir);
2079 return rc;
2080 }
2081 module_init(ntb_transport_init);
2082
2083 static void __exit ntb_transport_exit(void)
2084 {
2085 debugfs_remove_recursive(nt_debugfs_dir);
2086
2087 ntb_unregister_client(&ntb_transport_client);
2088 bus_unregister(&ntb_transport_bus);
2089 }
2090 module_exit(ntb_transport_exit);
Linux kernel - Deliverables
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