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NTB: fix access of free-ed pointer
[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, (u32)(size >> 32));
829
830 spad = MW0_SZ_LOW + (i * 2);
831 ntb_peer_spad_write(ndev, spad, (u32)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 struct ntb_transport_mw *mw;
932 phys_addr_t mw_base;
933 resource_size_t mw_size;
934 unsigned int num_qps_mw, tx_size;
935 unsigned int mw_num, mw_count, qp_count;
936 u64 qp_offset;
937
938 mw_count = nt->mw_count;
939 qp_count = nt->qp_count;
940
941 mw_num = QP_TO_MW(nt, qp_num);
942 mw = &nt->mw_vec[mw_num];
943
944 qp = &nt->qp_vec[qp_num];
945 qp->qp_num = qp_num;
946 qp->transport = nt;
947 qp->ndev = nt->ndev;
948 qp->client_ready = false;
949 qp->event_handler = NULL;
950 ntb_qp_link_down_reset(qp);
951
952 if (qp_count % mw_count && mw_num + 1 < qp_count / mw_count)
953 num_qps_mw = qp_count / mw_count + 1;
954 else
955 num_qps_mw = qp_count / mw_count;
956
957 mw_base = nt->mw_vec[mw_num].phys_addr;
958 mw_size = nt->mw_vec[mw_num].phys_size;
959
960 tx_size = (unsigned int)mw_size / num_qps_mw;
961 qp_offset = tx_size * qp_num / mw_count;
962
963 qp->tx_mw = nt->mw_vec[mw_num].vbase + qp_offset;
964 if (!qp->tx_mw)
965 return -EINVAL;
966
967 qp->tx_mw_phys = mw_base + qp_offset;
968 if (!qp->tx_mw_phys)
969 return -EINVAL;
970
971 tx_size -= sizeof(struct ntb_rx_info);
972 qp->rx_info = qp->tx_mw + tx_size;
973
974 /* Due to housekeeping, there must be atleast 2 buffs */
975 qp->tx_max_frame = min(transport_mtu, tx_size / 2);
976 qp->tx_max_entry = tx_size / qp->tx_max_frame;
977
978 if (nt->debugfs_node_dir) {
979 char debugfs_name[4];
980
981 snprintf(debugfs_name, 4, "qp%d", qp_num);
982 qp->debugfs_dir = debugfs_create_dir(debugfs_name,
983 nt->debugfs_node_dir);
984
985 qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR,
986 qp->debugfs_dir, qp,
987 &ntb_qp_debugfs_stats);
988 } else {
989 qp->debugfs_dir = NULL;
990 qp->debugfs_stats = NULL;
991 }
992
993 INIT_DELAYED_WORK(&qp->link_work, ntb_qp_link_work);
994 INIT_WORK(&qp->link_cleanup, ntb_qp_link_cleanup_work);
995
996 spin_lock_init(&qp->ntb_rx_q_lock);
997 spin_lock_init(&qp->ntb_tx_free_q_lock);
998
999 INIT_LIST_HEAD(&qp->rx_post_q);
1000 INIT_LIST_HEAD(&qp->rx_pend_q);
1001 INIT_LIST_HEAD(&qp->rx_free_q);
1002 INIT_LIST_HEAD(&qp->tx_free_q);
1003
1004 tasklet_init(&qp->rxc_db_work, ntb_transport_rxc_db,
1005 (unsigned long)qp);
1006
1007 return 0;
1008 }
1009
1010 static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev)
1011 {
1012 struct ntb_transport_ctx *nt;
1013 struct ntb_transport_mw *mw;
1014 unsigned int mw_count, qp_count;
1015 u64 qp_bitmap;
1016 int node;
1017 int rc, i;
1018
1019 if (ntb_db_is_unsafe(ndev))
1020 dev_dbg(&ndev->dev,
1021 "doorbell is unsafe, proceed anyway...\n");
1022 if (ntb_spad_is_unsafe(ndev))
1023 dev_dbg(&ndev->dev,
1024 "scratchpad is unsafe, proceed anyway...\n");
1025
1026 node = dev_to_node(&ndev->dev);
1027
1028 nt = kzalloc_node(sizeof(*nt), GFP_KERNEL, node);
1029 if (!nt)
1030 return -ENOMEM;
1031
1032 nt->ndev = ndev;
1033
1034 mw_count = ntb_mw_count(ndev);
1035
1036 nt->mw_count = mw_count;
1037
1038 nt->mw_vec = kzalloc_node(mw_count * sizeof(*nt->mw_vec),
1039 GFP_KERNEL, node);
1040 if (!nt->mw_vec) {
1041 rc = -ENOMEM;
1042 goto err;
1043 }
1044
1045 for (i = 0; i < mw_count; i++) {
1046 mw = &nt->mw_vec[i];
1047
1048 rc = ntb_mw_get_range(ndev, i, &mw->phys_addr, &mw->phys_size,
1049 &mw->xlat_align, &mw->xlat_align_size);
1050 if (rc)
1051 goto err1;
1052
1053 mw->vbase = ioremap_wc(mw->phys_addr, mw->phys_size);
1054 if (!mw->vbase) {
1055 rc = -ENOMEM;
1056 goto err1;
1057 }
1058
1059 mw->buff_size = 0;
1060 mw->xlat_size = 0;
1061 mw->virt_addr = NULL;
1062 mw->dma_addr = 0;
1063 }
1064
1065 qp_bitmap = ntb_db_valid_mask(ndev);
1066
1067 qp_count = ilog2(qp_bitmap);
1068 if (max_num_clients && max_num_clients < qp_count)
1069 qp_count = max_num_clients;
1070 else if (mw_count < qp_count)
1071 qp_count = mw_count;
1072
1073 qp_bitmap &= BIT_ULL(qp_count) - 1;
1074
1075 nt->qp_count = qp_count;
1076 nt->qp_bitmap = qp_bitmap;
1077 nt->qp_bitmap_free = qp_bitmap;
1078
1079 nt->qp_vec = kzalloc_node(qp_count * sizeof(*nt->qp_vec),
1080 GFP_KERNEL, node);
1081 if (!nt->qp_vec) {
1082 rc = -ENOMEM;
1083 goto err1;
1084 }
1085
1086 if (nt_debugfs_dir) {
1087 nt->debugfs_node_dir =
1088 debugfs_create_dir(pci_name(ndev->pdev),
1089 nt_debugfs_dir);
1090 }
1091
1092 for (i = 0; i < qp_count; i++) {
1093 rc = ntb_transport_init_queue(nt, i);
1094 if (rc)
1095 goto err2;
1096 }
1097
1098 INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work);
1099 INIT_WORK(&nt->link_cleanup, ntb_transport_link_cleanup_work);
1100
1101 rc = ntb_set_ctx(ndev, nt, &ntb_transport_ops);
1102 if (rc)
1103 goto err2;
1104
1105 INIT_LIST_HEAD(&nt->client_devs);
1106 rc = ntb_bus_init(nt);
1107 if (rc)
1108 goto err3;
1109
1110 nt->link_is_up = false;
1111 ntb_link_enable(ndev, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
1112 ntb_link_event(ndev);
1113
1114 return 0;
1115
1116 err3:
1117 ntb_clear_ctx(ndev);
1118 err2:
1119 kfree(nt->qp_vec);
1120 err1:
1121 while (i--) {
1122 mw = &nt->mw_vec[i];
1123 iounmap(mw->vbase);
1124 }
1125 kfree(nt->mw_vec);
1126 err:
1127 kfree(nt);
1128 return rc;
1129 }
1130
1131 static void ntb_transport_free(struct ntb_client *self, struct ntb_dev *ndev)
1132 {
1133 struct ntb_transport_ctx *nt = ndev->ctx;
1134 struct ntb_transport_qp *qp;
1135 u64 qp_bitmap_alloc;
1136 int i;
1137
1138 ntb_transport_link_cleanup(nt);
1139 cancel_work_sync(&nt->link_cleanup);
1140 cancel_delayed_work_sync(&nt->link_work);
1141
1142 qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
1143
1144 /* verify that all the qp's are freed */
1145 for (i = 0; i < nt->qp_count; i++) {
1146 qp = &nt->qp_vec[i];
1147 if (qp_bitmap_alloc & BIT_ULL(i))
1148 ntb_transport_free_queue(qp);
1149 debugfs_remove_recursive(qp->debugfs_dir);
1150 }
1151
1152 ntb_link_disable(ndev);
1153 ntb_clear_ctx(ndev);
1154
1155 ntb_bus_remove(nt);
1156
1157 for (i = nt->mw_count; i--; ) {
1158 ntb_free_mw(nt, i);
1159 iounmap(nt->mw_vec[i].vbase);
1160 }
1161
1162 kfree(nt->qp_vec);
1163 kfree(nt->mw_vec);
1164 kfree(nt);
1165 }
1166
1167 static void ntb_complete_rxc(struct ntb_transport_qp *qp)
1168 {
1169 struct ntb_queue_entry *entry;
1170 void *cb_data;
1171 unsigned int len;
1172 unsigned long irqflags;
1173
1174 spin_lock_irqsave(&qp->ntb_rx_q_lock, irqflags);
1175
1176 while (!list_empty(&qp->rx_post_q)) {
1177 entry = list_first_entry(&qp->rx_post_q,
1178 struct ntb_queue_entry, entry);
1179 if (!(entry->flags & DESC_DONE_FLAG))
1180 break;
1181
1182 entry->rx_hdr->flags = 0;
1183 iowrite32(entry->index, &qp->rx_info->entry);
1184
1185 cb_data = entry->cb_data;
1186 len = entry->len;
1187
1188 list_move_tail(&entry->entry, &qp->rx_free_q);
1189
1190 spin_unlock_irqrestore(&qp->ntb_rx_q_lock, irqflags);
1191
1192 if (qp->rx_handler && qp->client_ready)
1193 qp->rx_handler(qp, qp->cb_data, cb_data, len);
1194
1195 spin_lock_irqsave(&qp->ntb_rx_q_lock, irqflags);
1196 }
1197
1198 spin_unlock_irqrestore(&qp->ntb_rx_q_lock, irqflags);
1199 }
1200
1201 static void ntb_rx_copy_callback(void *data)
1202 {
1203 struct ntb_queue_entry *entry = data;
1204
1205 entry->flags |= DESC_DONE_FLAG;
1206
1207 ntb_complete_rxc(entry->qp);
1208 }
1209
1210 static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void *offset)
1211 {
1212 void *buf = entry->buf;
1213 size_t len = entry->len;
1214
1215 memcpy(buf, offset, len);
1216
1217 /* Ensure that the data is fully copied out before clearing the flag */
1218 wmb();
1219
1220 ntb_rx_copy_callback(entry);
1221 }
1222
1223 static void ntb_async_rx(struct ntb_queue_entry *entry, void *offset)
1224 {
1225 struct dma_async_tx_descriptor *txd;
1226 struct ntb_transport_qp *qp = entry->qp;
1227 struct dma_chan *chan = qp->rx_dma_chan;
1228 struct dma_device *device;
1229 size_t pay_off, buff_off, len;
1230 struct dmaengine_unmap_data *unmap;
1231 dma_cookie_t cookie;
1232 void *buf = entry->buf;
1233
1234 len = entry->len;
1235
1236 if (!chan)
1237 goto err;
1238
1239 if (len < copy_bytes)
1240 goto err;
1241
1242 device = chan->device;
1243 pay_off = (size_t)offset & ~PAGE_MASK;
1244 buff_off = (size_t)buf & ~PAGE_MASK;
1245
1246 if (!is_dma_copy_aligned(device, pay_off, buff_off, len))
1247 goto err;
1248
1249 unmap = dmaengine_get_unmap_data(device->dev, 2, GFP_NOWAIT);
1250 if (!unmap)
1251 goto err;
1252
1253 unmap->len = len;
1254 unmap->addr[0] = dma_map_page(device->dev, virt_to_page(offset),
1255 pay_off, len, DMA_TO_DEVICE);
1256 if (dma_mapping_error(device->dev, unmap->addr[0]))
1257 goto err_get_unmap;
1258
1259 unmap->to_cnt = 1;
1260
1261 unmap->addr[1] = dma_map_page(device->dev, virt_to_page(buf),
1262 buff_off, len, DMA_FROM_DEVICE);
1263 if (dma_mapping_error(device->dev, unmap->addr[1]))
1264 goto err_get_unmap;
1265
1266 unmap->from_cnt = 1;
1267
1268 txd = device->device_prep_dma_memcpy(chan, unmap->addr[1],
1269 unmap->addr[0], len,
1270 DMA_PREP_INTERRUPT);
1271 if (!txd)
1272 goto err_get_unmap;
1273
1274 txd->callback = ntb_rx_copy_callback;
1275 txd->callback_param = entry;
1276 dma_set_unmap(txd, unmap);
1277
1278 cookie = dmaengine_submit(txd);
1279 if (dma_submit_error(cookie))
1280 goto err_set_unmap;
1281
1282 dmaengine_unmap_put(unmap);
1283
1284 qp->last_cookie = cookie;
1285
1286 qp->rx_async++;
1287
1288 return;
1289
1290 err_set_unmap:
1291 dmaengine_unmap_put(unmap);
1292 err_get_unmap:
1293 dmaengine_unmap_put(unmap);
1294 err:
1295 ntb_memcpy_rx(entry, offset);
1296 qp->rx_memcpy++;
1297 }
1298
1299 static int ntb_process_rxc(struct ntb_transport_qp *qp)
1300 {
1301 struct ntb_payload_header *hdr;
1302 struct ntb_queue_entry *entry;
1303 void *offset;
1304
1305 offset = qp->rx_buff + qp->rx_max_frame * qp->rx_index;
1306 hdr = offset + qp->rx_max_frame - sizeof(struct ntb_payload_header);
1307
1308 dev_dbg(&qp->ndev->pdev->dev, "qp %d: RX ver %u len %d flags %x\n",
1309 qp->qp_num, hdr->ver, hdr->len, hdr->flags);
1310
1311 if (!(hdr->flags & DESC_DONE_FLAG)) {
1312 dev_dbg(&qp->ndev->pdev->dev, "done flag not set\n");
1313 qp->rx_ring_empty++;
1314 return -EAGAIN;
1315 }
1316
1317 if (hdr->flags & LINK_DOWN_FLAG) {
1318 dev_dbg(&qp->ndev->pdev->dev, "link down flag set\n");
1319 ntb_qp_link_down(qp);
1320 hdr->flags = 0;
1321 return -EAGAIN;
1322 }
1323
1324 if (hdr->ver != (u32)qp->rx_pkts) {
1325 dev_dbg(&qp->ndev->pdev->dev,
1326 "version mismatch, expected %llu - got %u\n",
1327 qp->rx_pkts, hdr->ver);
1328 qp->rx_err_ver++;
1329 return -EIO;
1330 }
1331
1332 entry = ntb_list_mv(&qp->ntb_rx_q_lock, &qp->rx_pend_q, &qp->rx_post_q);
1333 if (!entry) {
1334 dev_dbg(&qp->ndev->pdev->dev, "no receive buffer\n");
1335 qp->rx_err_no_buf++;
1336 return -EAGAIN;
1337 }
1338
1339 entry->rx_hdr = hdr;
1340 entry->index = qp->rx_index;
1341
1342 if (hdr->len > entry->len) {
1343 dev_dbg(&qp->ndev->pdev->dev,
1344 "receive buffer overflow! Wanted %d got %d\n",
1345 hdr->len, entry->len);
1346 qp->rx_err_oflow++;
1347
1348 entry->len = -EIO;
1349 entry->flags |= DESC_DONE_FLAG;
1350
1351 ntb_complete_rxc(qp);
1352 } else {
1353 dev_dbg(&qp->ndev->pdev->dev,
1354 "RX OK index %u ver %u size %d into buf size %d\n",
1355 qp->rx_index, hdr->ver, hdr->len, entry->len);
1356
1357 qp->rx_bytes += hdr->len;
1358 qp->rx_pkts++;
1359
1360 entry->len = hdr->len;
1361
1362 ntb_async_rx(entry, offset);
1363 }
1364
1365 qp->rx_index++;
1366 qp->rx_index %= qp->rx_max_entry;
1367
1368 return 0;
1369 }
1370
1371 static void ntb_transport_rxc_db(unsigned long data)
1372 {
1373 struct ntb_transport_qp *qp = (void *)data;
1374 int rc, i;
1375
1376 dev_dbg(&qp->ndev->pdev->dev, "%s: doorbell %d received\n",
1377 __func__, qp->qp_num);
1378
1379 /* Limit the number of packets processed in a single interrupt to
1380 * provide fairness to others
1381 */
1382 for (i = 0; i < qp->rx_max_entry; i++) {
1383 rc = ntb_process_rxc(qp);
1384 if (rc)
1385 break;
1386 }
1387
1388 if (i && qp->rx_dma_chan)
1389 dma_async_issue_pending(qp->rx_dma_chan);
1390
1391 if (i == qp->rx_max_entry) {
1392 /* there is more work to do */
1393 tasklet_schedule(&qp->rxc_db_work);
1394 } else if (ntb_db_read(qp->ndev) & BIT_ULL(qp->qp_num)) {
1395 /* the doorbell bit is set: clear it */
1396 ntb_db_clear(qp->ndev, BIT_ULL(qp->qp_num));
1397 /* ntb_db_read ensures ntb_db_clear write is committed */
1398 ntb_db_read(qp->ndev);
1399
1400 /* an interrupt may have arrived between finishing
1401 * ntb_process_rxc and clearing the doorbell bit:
1402 * there might be some more work to do.
1403 */
1404 tasklet_schedule(&qp->rxc_db_work);
1405 }
1406 }
1407
1408 static void ntb_tx_copy_callback(void *data)
1409 {
1410 struct ntb_queue_entry *entry = data;
1411 struct ntb_transport_qp *qp = entry->qp;
1412 struct ntb_payload_header __iomem *hdr = entry->tx_hdr;
1413
1414 iowrite32(entry->flags | DESC_DONE_FLAG, &hdr->flags);
1415
1416 ntb_peer_db_set(qp->ndev, BIT_ULL(qp->qp_num));
1417
1418 /* The entry length can only be zero if the packet is intended to be a
1419 * "link down" or similar. Since no payload is being sent in these
1420 * cases, there is nothing to add to the completion queue.
1421 */
1422 if (entry->len > 0) {
1423 qp->tx_bytes += entry->len;
1424
1425 if (qp->tx_handler)
1426 qp->tx_handler(qp, qp->cb_data, entry->cb_data,
1427 entry->len);
1428 }
1429
1430 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q);
1431 }
1432
1433 static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset)
1434 {
1435 #ifdef ARCH_HAS_NOCACHE_UACCESS
1436 /*
1437 * Using non-temporal mov to improve performance on non-cached
1438 * writes, even though we aren't actually copying from user space.
1439 */
1440 __copy_from_user_inatomic_nocache(offset, entry->buf, entry->len);
1441 #else
1442 memcpy_toio(offset, entry->buf, entry->len);
1443 #endif
1444
1445 /* Ensure that the data is fully copied out before setting the flags */
1446 wmb();
1447
1448 ntb_tx_copy_callback(entry);
1449 }
1450
1451 static void ntb_async_tx(struct ntb_transport_qp *qp,
1452 struct ntb_queue_entry *entry)
1453 {
1454 struct ntb_payload_header __iomem *hdr;
1455 struct dma_async_tx_descriptor *txd;
1456 struct dma_chan *chan = qp->tx_dma_chan;
1457 struct dma_device *device;
1458 size_t dest_off, buff_off;
1459 struct dmaengine_unmap_data *unmap;
1460 dma_addr_t dest;
1461 dma_cookie_t cookie;
1462 void __iomem *offset;
1463 size_t len = entry->len;
1464 void *buf = entry->buf;
1465
1466 offset = qp->tx_mw + qp->tx_max_frame * qp->tx_index;
1467 hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
1468 entry->tx_hdr = hdr;
1469
1470 iowrite32(entry->len, &hdr->len);
1471 iowrite32((u32)qp->tx_pkts, &hdr->ver);
1472
1473 if (!chan)
1474 goto err;
1475
1476 if (len < copy_bytes)
1477 goto err;
1478
1479 device = chan->device;
1480 dest = qp->tx_mw_phys + qp->tx_max_frame * qp->tx_index;
1481 buff_off = (size_t)buf & ~PAGE_MASK;
1482 dest_off = (size_t)dest & ~PAGE_MASK;
1483
1484 if (!is_dma_copy_aligned(device, buff_off, dest_off, len))
1485 goto err;
1486
1487 unmap = dmaengine_get_unmap_data(device->dev, 1, GFP_NOWAIT);
1488 if (!unmap)
1489 goto err;
1490
1491 unmap->len = len;
1492 unmap->addr[0] = dma_map_page(device->dev, virt_to_page(buf),
1493 buff_off, len, DMA_TO_DEVICE);
1494 if (dma_mapping_error(device->dev, unmap->addr[0]))
1495 goto err_get_unmap;
1496
1497 unmap->to_cnt = 1;
1498
1499 txd = device->device_prep_dma_memcpy(chan, dest, unmap->addr[0], len,
1500 DMA_PREP_INTERRUPT);
1501 if (!txd)
1502 goto err_get_unmap;
1503
1504 txd->callback = ntb_tx_copy_callback;
1505 txd->callback_param = entry;
1506 dma_set_unmap(txd, unmap);
1507
1508 cookie = dmaengine_submit(txd);
1509 if (dma_submit_error(cookie))
1510 goto err_set_unmap;
1511
1512 dmaengine_unmap_put(unmap);
1513
1514 dma_async_issue_pending(chan);
1515 qp->tx_async++;
1516
1517 return;
1518 err_set_unmap:
1519 dmaengine_unmap_put(unmap);
1520 err_get_unmap:
1521 dmaengine_unmap_put(unmap);
1522 err:
1523 ntb_memcpy_tx(entry, offset);
1524 qp->tx_memcpy++;
1525 }
1526
1527 static int ntb_process_tx(struct ntb_transport_qp *qp,
1528 struct ntb_queue_entry *entry)
1529 {
1530 if (qp->tx_index == qp->remote_rx_info->entry) {
1531 qp->tx_ring_full++;
1532 return -EAGAIN;
1533 }
1534
1535 if (entry->len > qp->tx_max_frame - sizeof(struct ntb_payload_header)) {
1536 if (qp->tx_handler)
1537 qp->tx_handler(qp->cb_data, qp, NULL, -EIO);
1538
1539 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1540 &qp->tx_free_q);
1541 return 0;
1542 }
1543
1544 ntb_async_tx(qp, entry);
1545
1546 qp->tx_index++;
1547 qp->tx_index %= qp->tx_max_entry;
1548
1549 qp->tx_pkts++;
1550
1551 return 0;
1552 }
1553
1554 static void ntb_send_link_down(struct ntb_transport_qp *qp)
1555 {
1556 struct pci_dev *pdev = qp->ndev->pdev;
1557 struct ntb_queue_entry *entry;
1558 int i, rc;
1559
1560 if (!qp->link_is_up)
1561 return;
1562
1563 dev_info(&pdev->dev, "qp %d: Send Link Down\n", qp->qp_num);
1564
1565 for (i = 0; i < NTB_LINK_DOWN_TIMEOUT; i++) {
1566 entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1567 if (entry)
1568 break;
1569 msleep(100);
1570 }
1571
1572 if (!entry)
1573 return;
1574
1575 entry->cb_data = NULL;
1576 entry->buf = NULL;
1577 entry->len = 0;
1578 entry->flags = LINK_DOWN_FLAG;
1579
1580 rc = ntb_process_tx(qp, entry);
1581 if (rc)
1582 dev_err(&pdev->dev, "ntb: QP%d unable to send linkdown msg\n",
1583 qp->qp_num);
1584
1585 ntb_qp_link_down_reset(qp);
1586 }
1587
1588 static bool ntb_dma_filter_fn(struct dma_chan *chan, void *node)
1589 {
1590 return dev_to_node(&chan->dev->device) == (int)(unsigned long)node;
1591 }
1592
1593 /**
1594 * ntb_transport_create_queue - Create a new NTB transport layer queue
1595 * @rx_handler: receive callback function
1596 * @tx_handler: transmit callback function
1597 * @event_handler: event callback function
1598 *
1599 * Create a new NTB transport layer queue and provide the queue with a callback
1600 * routine for both transmit and receive. The receive callback routine will be
1601 * used to pass up data when the transport has received it on the queue. The
1602 * transmit callback routine will be called when the transport has completed the
1603 * transmission of the data on the queue and the data is ready to be freed.
1604 *
1605 * RETURNS: pointer to newly created ntb_queue, NULL on error.
1606 */
1607 struct ntb_transport_qp *
1608 ntb_transport_create_queue(void *data, struct device *client_dev,
1609 const struct ntb_queue_handlers *handlers)
1610 {
1611 struct ntb_dev *ndev;
1612 struct pci_dev *pdev;
1613 struct ntb_transport_ctx *nt;
1614 struct ntb_queue_entry *entry;
1615 struct ntb_transport_qp *qp;
1616 u64 qp_bit;
1617 unsigned int free_queue;
1618 dma_cap_mask_t dma_mask;
1619 int node;
1620 int i;
1621
1622 ndev = dev_ntb(client_dev->parent);
1623 pdev = ndev->pdev;
1624 nt = ndev->ctx;
1625
1626 node = dev_to_node(&ndev->dev);
1627
1628 free_queue = ffs(nt->qp_bitmap);
1629 if (!free_queue)
1630 goto err;
1631
1632 /* decrement free_queue to make it zero based */
1633 free_queue--;
1634
1635 qp = &nt->qp_vec[free_queue];
1636 qp_bit = BIT_ULL(qp->qp_num);
1637
1638 nt->qp_bitmap_free &= ~qp_bit;
1639
1640 qp->cb_data = data;
1641 qp->rx_handler = handlers->rx_handler;
1642 qp->tx_handler = handlers->tx_handler;
1643 qp->event_handler = handlers->event_handler;
1644
1645 dma_cap_zero(dma_mask);
1646 dma_cap_set(DMA_MEMCPY, dma_mask);
1647
1648 if (use_dma) {
1649 qp->tx_dma_chan =
1650 dma_request_channel(dma_mask, ntb_dma_filter_fn,
1651 (void *)(unsigned long)node);
1652 if (!qp->tx_dma_chan)
1653 dev_info(&pdev->dev, "Unable to allocate TX DMA channel\n");
1654
1655 qp->rx_dma_chan =
1656 dma_request_channel(dma_mask, ntb_dma_filter_fn,
1657 (void *)(unsigned long)node);
1658 if (!qp->rx_dma_chan)
1659 dev_info(&pdev->dev, "Unable to allocate RX DMA channel\n");
1660 } else {
1661 qp->tx_dma_chan = NULL;
1662 qp->rx_dma_chan = NULL;
1663 }
1664
1665 dev_dbg(&pdev->dev, "Using %s memcpy for TX\n",
1666 qp->tx_dma_chan ? "DMA" : "CPU");
1667
1668 dev_dbg(&pdev->dev, "Using %s memcpy for RX\n",
1669 qp->rx_dma_chan ? "DMA" : "CPU");
1670
1671 for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
1672 entry = kzalloc_node(sizeof(*entry), GFP_ATOMIC, node);
1673 if (!entry)
1674 goto err1;
1675
1676 entry->qp = qp;
1677 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry,
1678 &qp->rx_free_q);
1679 }
1680
1681 for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
1682 entry = kzalloc_node(sizeof(*entry), GFP_ATOMIC, node);
1683 if (!entry)
1684 goto err2;
1685
1686 entry->qp = qp;
1687 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1688 &qp->tx_free_q);
1689 }
1690
1691 ntb_db_clear(qp->ndev, qp_bit);
1692 ntb_db_clear_mask(qp->ndev, qp_bit);
1693
1694 dev_info(&pdev->dev, "NTB Transport QP %d created\n", qp->qp_num);
1695
1696 return qp;
1697
1698 err2:
1699 while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1700 kfree(entry);
1701 err1:
1702 while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
1703 kfree(entry);
1704 if (qp->tx_dma_chan)
1705 dma_release_channel(qp->tx_dma_chan);
1706 if (qp->rx_dma_chan)
1707 dma_release_channel(qp->rx_dma_chan);
1708 nt->qp_bitmap_free |= qp_bit;
1709 err:
1710 return NULL;
1711 }
1712 EXPORT_SYMBOL_GPL(ntb_transport_create_queue);
1713
1714 /**
1715 * ntb_transport_free_queue - Frees NTB transport queue
1716 * @qp: NTB queue to be freed
1717 *
1718 * Frees NTB transport queue
1719 */
1720 void ntb_transport_free_queue(struct ntb_transport_qp *qp)
1721 {
1722 struct pci_dev *pdev;
1723 struct ntb_queue_entry *entry;
1724 u64 qp_bit;
1725
1726 if (!qp)
1727 return;
1728
1729 pdev = qp->ndev->pdev;
1730
1731 if (qp->tx_dma_chan) {
1732 struct dma_chan *chan = qp->tx_dma_chan;
1733 /* Putting the dma_chan to NULL will force any new traffic to be
1734 * processed by the CPU instead of the DAM engine
1735 */
1736 qp->tx_dma_chan = NULL;
1737
1738 /* Try to be nice and wait for any queued DMA engine
1739 * transactions to process before smashing it with a rock
1740 */
1741 dma_sync_wait(chan, qp->last_cookie);
1742 dmaengine_terminate_all(chan);
1743 dma_release_channel(chan);
1744 }
1745
1746 if (qp->rx_dma_chan) {
1747 struct dma_chan *chan = qp->rx_dma_chan;
1748 /* Putting the dma_chan to NULL will force any new traffic to be
1749 * processed by the CPU instead of the DAM engine
1750 */
1751 qp->rx_dma_chan = NULL;
1752
1753 /* Try to be nice and wait for any queued DMA engine
1754 * transactions to process before smashing it with a rock
1755 */
1756 dma_sync_wait(chan, qp->last_cookie);
1757 dmaengine_terminate_all(chan);
1758 dma_release_channel(chan);
1759 }
1760
1761 qp_bit = BIT_ULL(qp->qp_num);
1762
1763 ntb_db_set_mask(qp->ndev, qp_bit);
1764 tasklet_disable(&qp->rxc_db_work);
1765
1766 cancel_delayed_work_sync(&qp->link_work);
1767
1768 qp->cb_data = NULL;
1769 qp->rx_handler = NULL;
1770 qp->tx_handler = NULL;
1771 qp->event_handler = NULL;
1772
1773 while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
1774 kfree(entry);
1775
1776 while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_pend_q))) {
1777 dev_warn(&pdev->dev, "Freeing item from non-empty rx_pend_q\n");
1778 kfree(entry);
1779 }
1780
1781 while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_post_q))) {
1782 dev_warn(&pdev->dev, "Freeing item from non-empty rx_post_q\n");
1783 kfree(entry);
1784 }
1785
1786 while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1787 kfree(entry);
1788
1789 qp->transport->qp_bitmap_free |= qp_bit;
1790
1791 dev_info(&pdev->dev, "NTB Transport QP %d freed\n", qp->qp_num);
1792 }
1793 EXPORT_SYMBOL_GPL(ntb_transport_free_queue);
1794
1795 /**
1796 * ntb_transport_rx_remove - Dequeues enqueued rx packet
1797 * @qp: NTB queue to be freed
1798 * @len: pointer to variable to write enqueued buffers length
1799 *
1800 * Dequeues unused buffers from receive queue. Should only be used during
1801 * shutdown of qp.
1802 *
1803 * RETURNS: NULL error value on error, or void* for success.
1804 */
1805 void *ntb_transport_rx_remove(struct ntb_transport_qp *qp, unsigned int *len)
1806 {
1807 struct ntb_queue_entry *entry;
1808 void *buf;
1809
1810 if (!qp || qp->client_ready)
1811 return NULL;
1812
1813 entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_pend_q);
1814 if (!entry)
1815 return NULL;
1816
1817 buf = entry->cb_data;
1818 *len = entry->len;
1819
1820 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_free_q);
1821
1822 return buf;
1823 }
1824 EXPORT_SYMBOL_GPL(ntb_transport_rx_remove);
1825
1826 /**
1827 * ntb_transport_rx_enqueue - Enqueue a new NTB queue entry
1828 * @qp: NTB transport layer queue the entry is to be enqueued on
1829 * @cb: per buffer pointer for callback function to use
1830 * @data: pointer to data buffer that incoming packets will be copied into
1831 * @len: length of the data buffer
1832 *
1833 * Enqueue a new receive buffer onto the transport queue into which a NTB
1834 * payload can be received into.
1835 *
1836 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
1837 */
1838 int ntb_transport_rx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
1839 unsigned int len)
1840 {
1841 struct ntb_queue_entry *entry;
1842
1843 if (!qp)
1844 return -EINVAL;
1845
1846 entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q);
1847 if (!entry)
1848 return -ENOMEM;
1849
1850 entry->cb_data = cb;
1851 entry->buf = data;
1852 entry->len = len;
1853 entry->flags = 0;
1854
1855 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_pend_q);
1856
1857 tasklet_schedule(&qp->rxc_db_work);
1858
1859 return 0;
1860 }
1861 EXPORT_SYMBOL_GPL(ntb_transport_rx_enqueue);
1862
1863 /**
1864 * ntb_transport_tx_enqueue - Enqueue a new NTB queue entry
1865 * @qp: NTB transport layer queue the entry is to be enqueued on
1866 * @cb: per buffer pointer for callback function to use
1867 * @data: pointer to data buffer that will be sent
1868 * @len: length of the data buffer
1869 *
1870 * Enqueue a new transmit buffer onto the transport queue from which a NTB
1871 * payload will be transmitted. This assumes that a lock is being held to
1872 * serialize access to the qp.
1873 *
1874 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
1875 */
1876 int ntb_transport_tx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
1877 unsigned int len)
1878 {
1879 struct ntb_queue_entry *entry;
1880 int rc;
1881
1882 if (!qp || !qp->link_is_up || !len)
1883 return -EINVAL;
1884
1885 entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1886 if (!entry) {
1887 qp->tx_err_no_buf++;
1888 return -EBUSY;
1889 }
1890
1891 entry->cb_data = cb;
1892 entry->buf = data;
1893 entry->len = len;
1894 entry->flags = 0;
1895
1896 rc = ntb_process_tx(qp, entry);
1897 if (rc)
1898 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1899 &qp->tx_free_q);
1900
1901 return rc;
1902 }
1903 EXPORT_SYMBOL_GPL(ntb_transport_tx_enqueue);
1904
1905 /**
1906 * ntb_transport_link_up - Notify NTB transport of client readiness to use queue
1907 * @qp: NTB transport layer queue to be enabled
1908 *
1909 * Notify NTB transport layer of client readiness to use queue
1910 */
1911 void ntb_transport_link_up(struct ntb_transport_qp *qp)
1912 {
1913 if (!qp)
1914 return;
1915
1916 qp->client_ready = true;
1917
1918 if (qp->transport->link_is_up)
1919 schedule_delayed_work(&qp->link_work, 0);
1920 }
1921 EXPORT_SYMBOL_GPL(ntb_transport_link_up);
1922
1923 /**
1924 * ntb_transport_link_down - Notify NTB transport to no longer enqueue data
1925 * @qp: NTB transport layer queue to be disabled
1926 *
1927 * Notify NTB transport layer of client's desire to no longer receive data on
1928 * transport queue specified. It is the client's responsibility to ensure all
1929 * entries on queue are purged or otherwise handled appropriately.
1930 */
1931 void ntb_transport_link_down(struct ntb_transport_qp *qp)
1932 {
1933 struct pci_dev *pdev;
1934 int val;
1935
1936 if (!qp)
1937 return;
1938
1939 pdev = qp->ndev->pdev;
1940 qp->client_ready = false;
1941
1942 val = ntb_spad_read(qp->ndev, QP_LINKS);
1943
1944 ntb_peer_spad_write(qp->ndev, QP_LINKS,
1945 val & ~BIT(qp->qp_num));
1946
1947 if (qp->link_is_up)
1948 ntb_send_link_down(qp);
1949 else
1950 cancel_delayed_work_sync(&qp->link_work);
1951 }
1952 EXPORT_SYMBOL_GPL(ntb_transport_link_down);
1953
1954 /**
1955 * ntb_transport_link_query - Query transport link state
1956 * @qp: NTB transport layer queue to be queried
1957 *
1958 * Query connectivity to the remote system of the NTB transport queue
1959 *
1960 * RETURNS: true for link up or false for link down
1961 */
1962 bool ntb_transport_link_query(struct ntb_transport_qp *qp)
1963 {
1964 if (!qp)
1965 return false;
1966
1967 return qp->link_is_up;
1968 }
1969 EXPORT_SYMBOL_GPL(ntb_transport_link_query);
1970
1971 /**
1972 * ntb_transport_qp_num - Query the qp number
1973 * @qp: NTB transport layer queue to be queried
1974 *
1975 * Query qp number of the NTB transport queue
1976 *
1977 * RETURNS: a zero based number specifying the qp number
1978 */
1979 unsigned char ntb_transport_qp_num(struct ntb_transport_qp *qp)
1980 {
1981 if (!qp)
1982 return 0;
1983
1984 return qp->qp_num;
1985 }
1986 EXPORT_SYMBOL_GPL(ntb_transport_qp_num);
1987
1988 /**
1989 * ntb_transport_max_size - Query the max payload size of a qp
1990 * @qp: NTB transport layer queue to be queried
1991 *
1992 * Query the maximum payload size permissible on the given qp
1993 *
1994 * RETURNS: the max payload size of a qp
1995 */
1996 unsigned int ntb_transport_max_size(struct ntb_transport_qp *qp)
1997 {
1998 unsigned int max_size;
1999 unsigned int copy_align;
2000 struct dma_chan *rx_chan, *tx_chan;
2001
2002 if (!qp)
2003 return 0;
2004
2005 rx_chan = qp->rx_dma_chan;
2006 tx_chan = qp->tx_dma_chan;
2007
2008 copy_align = max(rx_chan ? rx_chan->device->copy_align : 0,
2009 tx_chan ? tx_chan->device->copy_align : 0);
2010
2011 /* If DMA engine usage is possible, try to find the max size for that */
2012 max_size = qp->tx_max_frame - sizeof(struct ntb_payload_header);
2013 max_size = round_down(max_size, 1 << copy_align);
2014
2015 return max_size;
2016 }
2017 EXPORT_SYMBOL_GPL(ntb_transport_max_size);
2018
2019 unsigned int ntb_transport_tx_free_entry(struct ntb_transport_qp *qp)
2020 {
2021 unsigned int head = qp->tx_index;
2022 unsigned int tail = qp->remote_rx_info->entry;
2023
2024 return tail > head ? tail - head : qp->tx_max_entry + tail - head;
2025 }
2026 EXPORT_SYMBOL_GPL(ntb_transport_tx_free_entry);
2027
2028 static void ntb_transport_doorbell_callback(void *data, int vector)
2029 {
2030 struct ntb_transport_ctx *nt = data;
2031 struct ntb_transport_qp *qp;
2032 u64 db_bits;
2033 unsigned int qp_num;
2034
2035 db_bits = (nt->qp_bitmap & ~nt->qp_bitmap_free &
2036 ntb_db_vector_mask(nt->ndev, vector));
2037
2038 while (db_bits) {
2039 qp_num = __ffs(db_bits);
2040 qp = &nt->qp_vec[qp_num];
2041
2042 tasklet_schedule(&qp->rxc_db_work);
2043
2044 db_bits &= ~BIT_ULL(qp_num);
2045 }
2046 }
2047
2048 static const struct ntb_ctx_ops ntb_transport_ops = {
2049 .link_event = ntb_transport_event_callback,
2050 .db_event = ntb_transport_doorbell_callback,
2051 };
2052
2053 static struct ntb_client ntb_transport_client = {
2054 .ops = {
2055 .probe = ntb_transport_probe,
2056 .remove = ntb_transport_free,
2057 },
2058 };
2059
2060 static int __init ntb_transport_init(void)
2061 {
2062 int rc;
2063
2064 pr_info("%s, version %s\n", NTB_TRANSPORT_DESC, NTB_TRANSPORT_VER);
2065
2066 if (debugfs_initialized())
2067 nt_debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
2068
2069 rc = bus_register(&ntb_transport_bus);
2070 if (rc)
2071 goto err_bus;
2072
2073 rc = ntb_register_client(&ntb_transport_client);
2074 if (rc)
2075 goto err_client;
2076
2077 return 0;
2078
2079 err_client:
2080 bus_unregister(&ntb_transport_bus);
2081 err_bus:
2082 debugfs_remove_recursive(nt_debugfs_dir);
2083 return rc;
2084 }
2085 module_init(ntb_transport_init);
2086
2087 static void __exit ntb_transport_exit(void)
2088 {
2089 debugfs_remove_recursive(nt_debugfs_dir);
2090
2091 ntb_unregister_client(&ntb_transport_client);
2092 bus_unregister(&ntb_transport_bus);
2093 }
2094 module_exit(ntb_transport_exit);
Linux kernel - Deliverables
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