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Merge branch 'for-4.6-ns' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
[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 dma_rx_prep_err;
175 u64 tx_bytes;
176 u64 tx_pkts;
177 u64 tx_ring_full;
178 u64 tx_err_no_buf;
179 u64 tx_memcpy;
180 u64 tx_async;
181 u64 dma_tx_prep_err;
182 };
183
184 struct ntb_transport_mw {
185 phys_addr_t phys_addr;
186 resource_size_t phys_size;
187 resource_size_t xlat_align;
188 resource_size_t xlat_align_size;
189 void __iomem *vbase;
190 size_t xlat_size;
191 size_t buff_size;
192 void *virt_addr;
193 dma_addr_t dma_addr;
194 };
195
196 struct ntb_transport_client_dev {
197 struct list_head entry;
198 struct ntb_transport_ctx *nt;
199 struct device dev;
200 };
201
202 struct ntb_transport_ctx {
203 struct list_head entry;
204 struct list_head client_devs;
205
206 struct ntb_dev *ndev;
207
208 struct ntb_transport_mw *mw_vec;
209 struct ntb_transport_qp *qp_vec;
210 unsigned int mw_count;
211 unsigned int qp_count;
212 u64 qp_bitmap;
213 u64 qp_bitmap_free;
214
215 bool link_is_up;
216 struct delayed_work link_work;
217 struct work_struct link_cleanup;
218
219 struct dentry *debugfs_node_dir;
220 };
221
222 enum {
223 DESC_DONE_FLAG = BIT(0),
224 LINK_DOWN_FLAG = BIT(1),
225 };
226
227 struct ntb_payload_header {
228 unsigned int ver;
229 unsigned int len;
230 unsigned int flags;
231 };
232
233 enum {
234 VERSION = 0,
235 QP_LINKS,
236 NUM_QPS,
237 NUM_MWS,
238 MW0_SZ_HIGH,
239 MW0_SZ_LOW,
240 MW1_SZ_HIGH,
241 MW1_SZ_LOW,
242 MAX_SPAD,
243 };
244
245 #define dev_client_dev(__dev) \
246 container_of((__dev), struct ntb_transport_client_dev, dev)
247
248 #define drv_client(__drv) \
249 container_of((__drv), struct ntb_transport_client, driver)
250
251 #define QP_TO_MW(nt, qp) ((qp) % nt->mw_count)
252 #define NTB_QP_DEF_NUM_ENTRIES 100
253 #define NTB_LINK_DOWN_TIMEOUT 10
254 #define DMA_RETRIES 20
255 #define DMA_OUT_RESOURCE_TO 50
256
257 static void ntb_transport_rxc_db(unsigned long data);
258 static const struct ntb_ctx_ops ntb_transport_ops;
259 static struct ntb_client ntb_transport_client;
260
261 static int ntb_transport_bus_match(struct device *dev,
262 struct device_driver *drv)
263 {
264 return !strncmp(dev_name(dev), drv->name, strlen(drv->name));
265 }
266
267 static int ntb_transport_bus_probe(struct device *dev)
268 {
269 const struct ntb_transport_client *client;
270 int rc = -EINVAL;
271
272 get_device(dev);
273
274 client = drv_client(dev->driver);
275 rc = client->probe(dev);
276 if (rc)
277 put_device(dev);
278
279 return rc;
280 }
281
282 static int ntb_transport_bus_remove(struct device *dev)
283 {
284 const struct ntb_transport_client *client;
285
286 client = drv_client(dev->driver);
287 client->remove(dev);
288
289 put_device(dev);
290
291 return 0;
292 }
293
294 static struct bus_type ntb_transport_bus = {
295 .name = "ntb_transport",
296 .match = ntb_transport_bus_match,
297 .probe = ntb_transport_bus_probe,
298 .remove = ntb_transport_bus_remove,
299 };
300
301 static LIST_HEAD(ntb_transport_list);
302
303 static int ntb_bus_init(struct ntb_transport_ctx *nt)
304 {
305 list_add_tail(&nt->entry, &ntb_transport_list);
306 return 0;
307 }
308
309 static void ntb_bus_remove(struct ntb_transport_ctx *nt)
310 {
311 struct ntb_transport_client_dev *client_dev, *cd;
312
313 list_for_each_entry_safe(client_dev, cd, &nt->client_devs, entry) {
314 dev_err(client_dev->dev.parent, "%s still attached to bus, removing\n",
315 dev_name(&client_dev->dev));
316 list_del(&client_dev->entry);
317 device_unregister(&client_dev->dev);
318 }
319
320 list_del(&nt->entry);
321 }
322
323 static void ntb_transport_client_release(struct device *dev)
324 {
325 struct ntb_transport_client_dev *client_dev;
326
327 client_dev = dev_client_dev(dev);
328 kfree(client_dev);
329 }
330
331 /**
332 * ntb_transport_unregister_client_dev - Unregister NTB client device
333 * @device_name: Name of NTB client device
334 *
335 * Unregister an NTB client device with the NTB transport layer
336 */
337 void ntb_transport_unregister_client_dev(char *device_name)
338 {
339 struct ntb_transport_client_dev *client, *cd;
340 struct ntb_transport_ctx *nt;
341
342 list_for_each_entry(nt, &ntb_transport_list, entry)
343 list_for_each_entry_safe(client, cd, &nt->client_devs, entry)
344 if (!strncmp(dev_name(&client->dev), device_name,
345 strlen(device_name))) {
346 list_del(&client->entry);
347 device_unregister(&client->dev);
348 }
349 }
350 EXPORT_SYMBOL_GPL(ntb_transport_unregister_client_dev);
351
352 /**
353 * ntb_transport_register_client_dev - Register NTB client device
354 * @device_name: Name of NTB client device
355 *
356 * Register an NTB client device with the NTB transport layer
357 */
358 int ntb_transport_register_client_dev(char *device_name)
359 {
360 struct ntb_transport_client_dev *client_dev;
361 struct ntb_transport_ctx *nt;
362 int node;
363 int rc, i = 0;
364
365 if (list_empty(&ntb_transport_list))
366 return -ENODEV;
367
368 list_for_each_entry(nt, &ntb_transport_list, entry) {
369 struct device *dev;
370
371 node = dev_to_node(&nt->ndev->dev);
372
373 client_dev = kzalloc_node(sizeof(*client_dev),
374 GFP_KERNEL, node);
375 if (!client_dev) {
376 rc = -ENOMEM;
377 goto err;
378 }
379
380 dev = &client_dev->dev;
381
382 /* setup and register client devices */
383 dev_set_name(dev, "%s%d", device_name, i);
384 dev->bus = &ntb_transport_bus;
385 dev->release = ntb_transport_client_release;
386 dev->parent = &nt->ndev->dev;
387
388 rc = device_register(dev);
389 if (rc) {
390 kfree(client_dev);
391 goto err;
392 }
393
394 list_add_tail(&client_dev->entry, &nt->client_devs);
395 i++;
396 }
397
398 return 0;
399
400 err:
401 ntb_transport_unregister_client_dev(device_name);
402
403 return rc;
404 }
405 EXPORT_SYMBOL_GPL(ntb_transport_register_client_dev);
406
407 /**
408 * ntb_transport_register_client - Register NTB client driver
409 * @drv: NTB client driver to be registered
410 *
411 * Register an NTB client driver with the NTB transport layer
412 *
413 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
414 */
415 int ntb_transport_register_client(struct ntb_transport_client *drv)
416 {
417 drv->driver.bus = &ntb_transport_bus;
418
419 if (list_empty(&ntb_transport_list))
420 return -ENODEV;
421
422 return driver_register(&drv->driver);
423 }
424 EXPORT_SYMBOL_GPL(ntb_transport_register_client);
425
426 /**
427 * ntb_transport_unregister_client - Unregister NTB client driver
428 * @drv: NTB client driver to be unregistered
429 *
430 * Unregister an NTB client driver with the NTB transport layer
431 *
432 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
433 */
434 void ntb_transport_unregister_client(struct ntb_transport_client *drv)
435 {
436 driver_unregister(&drv->driver);
437 }
438 EXPORT_SYMBOL_GPL(ntb_transport_unregister_client);
439
440 static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count,
441 loff_t *offp)
442 {
443 struct ntb_transport_qp *qp;
444 char *buf;
445 ssize_t ret, out_offset, out_count;
446
447 qp = filp->private_data;
448
449 if (!qp || !qp->link_is_up)
450 return 0;
451
452 out_count = 1000;
453
454 buf = kmalloc(out_count, GFP_KERNEL);
455 if (!buf)
456 return -ENOMEM;
457
458 out_offset = 0;
459 out_offset += snprintf(buf + out_offset, out_count - out_offset,
460 "\nNTB QP stats:\n\n");
461 out_offset += snprintf(buf + out_offset, out_count - out_offset,
462 "rx_bytes - \t%llu\n", qp->rx_bytes);
463 out_offset += snprintf(buf + out_offset, out_count - out_offset,
464 "rx_pkts - \t%llu\n", qp->rx_pkts);
465 out_offset += snprintf(buf + out_offset, out_count - out_offset,
466 "rx_memcpy - \t%llu\n", qp->rx_memcpy);
467 out_offset += snprintf(buf + out_offset, out_count - out_offset,
468 "rx_async - \t%llu\n", qp->rx_async);
469 out_offset += snprintf(buf + out_offset, out_count - out_offset,
470 "rx_ring_empty - %llu\n", qp->rx_ring_empty);
471 out_offset += snprintf(buf + out_offset, out_count - out_offset,
472 "rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
473 out_offset += snprintf(buf + out_offset, out_count - out_offset,
474 "rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
475 out_offset += snprintf(buf + out_offset, out_count - out_offset,
476 "rx_err_ver - \t%llu\n", qp->rx_err_ver);
477 out_offset += snprintf(buf + out_offset, out_count - out_offset,
478 "rx_buff - \t0x%p\n", qp->rx_buff);
479 out_offset += snprintf(buf + out_offset, out_count - out_offset,
480 "rx_index - \t%u\n", qp->rx_index);
481 out_offset += snprintf(buf + out_offset, out_count - out_offset,
482 "rx_max_entry - \t%u\n\n", qp->rx_max_entry);
483
484 out_offset += snprintf(buf + out_offset, out_count - out_offset,
485 "tx_bytes - \t%llu\n", qp->tx_bytes);
486 out_offset += snprintf(buf + out_offset, out_count - out_offset,
487 "tx_pkts - \t%llu\n", qp->tx_pkts);
488 out_offset += snprintf(buf + out_offset, out_count - out_offset,
489 "tx_memcpy - \t%llu\n", qp->tx_memcpy);
490 out_offset += snprintf(buf + out_offset, out_count - out_offset,
491 "tx_async - \t%llu\n", qp->tx_async);
492 out_offset += snprintf(buf + out_offset, out_count - out_offset,
493 "tx_ring_full - \t%llu\n", qp->tx_ring_full);
494 out_offset += snprintf(buf + out_offset, out_count - out_offset,
495 "tx_err_no_buf - %llu\n", qp->tx_err_no_buf);
496 out_offset += snprintf(buf + out_offset, out_count - out_offset,
497 "tx_mw - \t0x%p\n", qp->tx_mw);
498 out_offset += snprintf(buf + out_offset, out_count - out_offset,
499 "tx_index (H) - \t%u\n", qp->tx_index);
500 out_offset += snprintf(buf + out_offset, out_count - out_offset,
501 "RRI (T) - \t%u\n",
502 qp->remote_rx_info->entry);
503 out_offset += snprintf(buf + out_offset, out_count - out_offset,
504 "tx_max_entry - \t%u\n", qp->tx_max_entry);
505 out_offset += snprintf(buf + out_offset, out_count - out_offset,
506 "free tx - \t%u\n",
507 ntb_transport_tx_free_entry(qp));
508 out_offset += snprintf(buf + out_offset, out_count - out_offset,
509 "DMA tx prep err - \t%llu\n",
510 qp->dma_tx_prep_err);
511 out_offset += snprintf(buf + out_offset, out_count - out_offset,
512 "DMA rx prep err - \t%llu\n",
513 qp->dma_rx_prep_err);
514
515 out_offset += snprintf(buf + out_offset, out_count - out_offset,
516 "\n");
517 out_offset += snprintf(buf + out_offset, out_count - out_offset,
518 "Using TX DMA - \t%s\n",
519 qp->tx_dma_chan ? "Yes" : "No");
520 out_offset += snprintf(buf + out_offset, out_count - out_offset,
521 "Using RX DMA - \t%s\n",
522 qp->rx_dma_chan ? "Yes" : "No");
523 out_offset += snprintf(buf + out_offset, out_count - out_offset,
524 "QP Link - \t%s\n",
525 qp->link_is_up ? "Up" : "Down");
526 out_offset += snprintf(buf + out_offset, out_count - out_offset,
527 "\n");
528
529 if (out_offset > out_count)
530 out_offset = out_count;
531
532 ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
533 kfree(buf);
534 return ret;
535 }
536
537 static const struct file_operations ntb_qp_debugfs_stats = {
538 .owner = THIS_MODULE,
539 .open = simple_open,
540 .read = debugfs_read,
541 };
542
543 static void ntb_list_add(spinlock_t *lock, struct list_head *entry,
544 struct list_head *list)
545 {
546 unsigned long flags;
547
548 spin_lock_irqsave(lock, flags);
549 list_add_tail(entry, list);
550 spin_unlock_irqrestore(lock, flags);
551 }
552
553 static struct ntb_queue_entry *ntb_list_rm(spinlock_t *lock,
554 struct list_head *list)
555 {
556 struct ntb_queue_entry *entry;
557 unsigned long flags;
558
559 spin_lock_irqsave(lock, flags);
560 if (list_empty(list)) {
561 entry = NULL;
562 goto out;
563 }
564 entry = list_first_entry(list, struct ntb_queue_entry, entry);
565 list_del(&entry->entry);
566
567 out:
568 spin_unlock_irqrestore(lock, flags);
569
570 return entry;
571 }
572
573 static struct ntb_queue_entry *ntb_list_mv(spinlock_t *lock,
574 struct list_head *list,
575 struct list_head *to_list)
576 {
577 struct ntb_queue_entry *entry;
578 unsigned long flags;
579
580 spin_lock_irqsave(lock, flags);
581
582 if (list_empty(list)) {
583 entry = NULL;
584 } else {
585 entry = list_first_entry(list, struct ntb_queue_entry, entry);
586 list_move_tail(&entry->entry, to_list);
587 }
588
589 spin_unlock_irqrestore(lock, flags);
590
591 return entry;
592 }
593
594 static int ntb_transport_setup_qp_mw(struct ntb_transport_ctx *nt,
595 unsigned int qp_num)
596 {
597 struct ntb_transport_qp *qp = &nt->qp_vec[qp_num];
598 struct ntb_transport_mw *mw;
599 unsigned int rx_size, num_qps_mw;
600 unsigned int mw_num, mw_count, qp_count;
601 unsigned int i;
602
603 mw_count = nt->mw_count;
604 qp_count = nt->qp_count;
605
606 mw_num = QP_TO_MW(nt, qp_num);
607 mw = &nt->mw_vec[mw_num];
608
609 if (!mw->virt_addr)
610 return -ENOMEM;
611
612 if (qp_count % mw_count && mw_num + 1 < qp_count / mw_count)
613 num_qps_mw = qp_count / mw_count + 1;
614 else
615 num_qps_mw = qp_count / mw_count;
616
617 rx_size = (unsigned int)mw->xlat_size / num_qps_mw;
618 qp->rx_buff = mw->virt_addr + rx_size * (qp_num / mw_count);
619 rx_size -= sizeof(struct ntb_rx_info);
620
621 qp->remote_rx_info = qp->rx_buff + rx_size;
622
623 /* Due to housekeeping, there must be atleast 2 buffs */
624 qp->rx_max_frame = min(transport_mtu, rx_size / 2);
625 qp->rx_max_entry = rx_size / qp->rx_max_frame;
626 qp->rx_index = 0;
627
628 qp->remote_rx_info->entry = qp->rx_max_entry - 1;
629
630 /* setup the hdr offsets with 0's */
631 for (i = 0; i < qp->rx_max_entry; i++) {
632 void *offset = (qp->rx_buff + qp->rx_max_frame * (i + 1) -
633 sizeof(struct ntb_payload_header));
634 memset(offset, 0, sizeof(struct ntb_payload_header));
635 }
636
637 qp->rx_pkts = 0;
638 qp->tx_pkts = 0;
639 qp->tx_index = 0;
640
641 return 0;
642 }
643
644 static void ntb_free_mw(struct ntb_transport_ctx *nt, int num_mw)
645 {
646 struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
647 struct pci_dev *pdev = nt->ndev->pdev;
648
649 if (!mw->virt_addr)
650 return;
651
652 ntb_mw_clear_trans(nt->ndev, num_mw);
653 dma_free_coherent(&pdev->dev, mw->buff_size,
654 mw->virt_addr, mw->dma_addr);
655 mw->xlat_size = 0;
656 mw->buff_size = 0;
657 mw->virt_addr = NULL;
658 }
659
660 static int ntb_set_mw(struct ntb_transport_ctx *nt, int num_mw,
661 resource_size_t size)
662 {
663 struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
664 struct pci_dev *pdev = nt->ndev->pdev;
665 size_t xlat_size, buff_size;
666 int rc;
667
668 if (!size)
669 return -EINVAL;
670
671 xlat_size = round_up(size, mw->xlat_align_size);
672 buff_size = round_up(size, mw->xlat_align);
673
674 /* No need to re-setup */
675 if (mw->xlat_size == xlat_size)
676 return 0;
677
678 if (mw->buff_size)
679 ntb_free_mw(nt, num_mw);
680
681 /* Alloc memory for receiving data. Must be aligned */
682 mw->xlat_size = xlat_size;
683 mw->buff_size = buff_size;
684
685 mw->virt_addr = dma_alloc_coherent(&pdev->dev, buff_size,
686 &mw->dma_addr, GFP_KERNEL);
687 if (!mw->virt_addr) {
688 mw->xlat_size = 0;
689 mw->buff_size = 0;
690 dev_err(&pdev->dev, "Unable to alloc MW buff of size %zu\n",
691 buff_size);
692 return -ENOMEM;
693 }
694
695 /*
696 * we must ensure that the memory address allocated is BAR size
697 * aligned in order for the XLAT register to take the value. This
698 * is a requirement of the hardware. It is recommended to setup CMA
699 * for BAR sizes equal or greater than 4MB.
700 */
701 if (!IS_ALIGNED(mw->dma_addr, mw->xlat_align)) {
702 dev_err(&pdev->dev, "DMA memory %pad is not aligned\n",
703 &mw->dma_addr);
704 ntb_free_mw(nt, num_mw);
705 return -ENOMEM;
706 }
707
708 /* Notify HW the memory location of the receive buffer */
709 rc = ntb_mw_set_trans(nt->ndev, num_mw, mw->dma_addr, mw->xlat_size);
710 if (rc) {
711 dev_err(&pdev->dev, "Unable to set mw%d translation", num_mw);
712 ntb_free_mw(nt, num_mw);
713 return -EIO;
714 }
715
716 return 0;
717 }
718
719 static void ntb_qp_link_down_reset(struct ntb_transport_qp *qp)
720 {
721 qp->link_is_up = false;
722
723 qp->tx_index = 0;
724 qp->rx_index = 0;
725 qp->rx_bytes = 0;
726 qp->rx_pkts = 0;
727 qp->rx_ring_empty = 0;
728 qp->rx_err_no_buf = 0;
729 qp->rx_err_oflow = 0;
730 qp->rx_err_ver = 0;
731 qp->rx_memcpy = 0;
732 qp->rx_async = 0;
733 qp->tx_bytes = 0;
734 qp->tx_pkts = 0;
735 qp->tx_ring_full = 0;
736 qp->tx_err_no_buf = 0;
737 qp->tx_memcpy = 0;
738 qp->tx_async = 0;
739 qp->dma_tx_prep_err = 0;
740 qp->dma_rx_prep_err = 0;
741 }
742
743 static void ntb_qp_link_cleanup(struct ntb_transport_qp *qp)
744 {
745 struct ntb_transport_ctx *nt = qp->transport;
746 struct pci_dev *pdev = nt->ndev->pdev;
747
748 dev_info(&pdev->dev, "qp %d: Link Cleanup\n", qp->qp_num);
749
750 cancel_delayed_work_sync(&qp->link_work);
751 ntb_qp_link_down_reset(qp);
752
753 if (qp->event_handler)
754 qp->event_handler(qp->cb_data, qp->link_is_up);
755 }
756
757 static void ntb_qp_link_cleanup_work(struct work_struct *work)
758 {
759 struct ntb_transport_qp *qp = container_of(work,
760 struct ntb_transport_qp,
761 link_cleanup);
762 struct ntb_transport_ctx *nt = qp->transport;
763
764 ntb_qp_link_cleanup(qp);
765
766 if (nt->link_is_up)
767 schedule_delayed_work(&qp->link_work,
768 msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
769 }
770
771 static void ntb_qp_link_down(struct ntb_transport_qp *qp)
772 {
773 schedule_work(&qp->link_cleanup);
774 }
775
776 static void ntb_transport_link_cleanup(struct ntb_transport_ctx *nt)
777 {
778 struct ntb_transport_qp *qp;
779 u64 qp_bitmap_alloc;
780 int i;
781
782 qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
783
784 /* Pass along the info to any clients */
785 for (i = 0; i < nt->qp_count; i++)
786 if (qp_bitmap_alloc & BIT_ULL(i)) {
787 qp = &nt->qp_vec[i];
788 ntb_qp_link_cleanup(qp);
789 cancel_work_sync(&qp->link_cleanup);
790 cancel_delayed_work_sync(&qp->link_work);
791 }
792
793 if (!nt->link_is_up)
794 cancel_delayed_work_sync(&nt->link_work);
795
796 /* The scratchpad registers keep the values if the remote side
797 * goes down, blast them now to give them a sane value the next
798 * time they are accessed
799 */
800 for (i = 0; i < MAX_SPAD; i++)
801 ntb_spad_write(nt->ndev, i, 0);
802 }
803
804 static void ntb_transport_link_cleanup_work(struct work_struct *work)
805 {
806 struct ntb_transport_ctx *nt =
807 container_of(work, struct ntb_transport_ctx, link_cleanup);
808
809 ntb_transport_link_cleanup(nt);
810 }
811
812 static void ntb_transport_event_callback(void *data)
813 {
814 struct ntb_transport_ctx *nt = data;
815
816 if (ntb_link_is_up(nt->ndev, NULL, NULL) == 1)
817 schedule_delayed_work(&nt->link_work, 0);
818 else
819 schedule_work(&nt->link_cleanup);
820 }
821
822 static void ntb_transport_link_work(struct work_struct *work)
823 {
824 struct ntb_transport_ctx *nt =
825 container_of(work, struct ntb_transport_ctx, link_work.work);
826 struct ntb_dev *ndev = nt->ndev;
827 struct pci_dev *pdev = ndev->pdev;
828 resource_size_t size;
829 u32 val;
830 int rc, i, spad;
831
832 /* send the local info, in the opposite order of the way we read it */
833 for (i = 0; i < nt->mw_count; i++) {
834 size = nt->mw_vec[i].phys_size;
835
836 if (max_mw_size && size > max_mw_size)
837 size = max_mw_size;
838
839 spad = MW0_SZ_HIGH + (i * 2);
840 ntb_peer_spad_write(ndev, spad, upper_32_bits(size));
841
842 spad = MW0_SZ_LOW + (i * 2);
843 ntb_peer_spad_write(ndev, spad, lower_32_bits(size));
844 }
845
846 ntb_peer_spad_write(ndev, NUM_MWS, nt->mw_count);
847
848 ntb_peer_spad_write(ndev, NUM_QPS, nt->qp_count);
849
850 ntb_peer_spad_write(ndev, VERSION, NTB_TRANSPORT_VERSION);
851
852 /* Query the remote side for its info */
853 val = ntb_spad_read(ndev, VERSION);
854 dev_dbg(&pdev->dev, "Remote version = %d\n", val);
855 if (val != NTB_TRANSPORT_VERSION)
856 goto out;
857
858 val = ntb_spad_read(ndev, NUM_QPS);
859 dev_dbg(&pdev->dev, "Remote max number of qps = %d\n", val);
860 if (val != nt->qp_count)
861 goto out;
862
863 val = ntb_spad_read(ndev, NUM_MWS);
864 dev_dbg(&pdev->dev, "Remote number of mws = %d\n", val);
865 if (val != nt->mw_count)
866 goto out;
867
868 for (i = 0; i < nt->mw_count; i++) {
869 u64 val64;
870
871 val = ntb_spad_read(ndev, MW0_SZ_HIGH + (i * 2));
872 val64 = (u64)val << 32;
873
874 val = ntb_spad_read(ndev, MW0_SZ_LOW + (i * 2));
875 val64 |= val;
876
877 dev_dbg(&pdev->dev, "Remote MW%d size = %#llx\n", i, val64);
878
879 rc = ntb_set_mw(nt, i, val64);
880 if (rc)
881 goto out1;
882 }
883
884 nt->link_is_up = true;
885
886 for (i = 0; i < nt->qp_count; i++) {
887 struct ntb_transport_qp *qp = &nt->qp_vec[i];
888
889 ntb_transport_setup_qp_mw(nt, i);
890
891 if (qp->client_ready)
892 schedule_delayed_work(&qp->link_work, 0);
893 }
894
895 return;
896
897 out1:
898 for (i = 0; i < nt->mw_count; i++)
899 ntb_free_mw(nt, i);
900 out:
901 if (ntb_link_is_up(ndev, NULL, NULL) == 1)
902 schedule_delayed_work(&nt->link_work,
903 msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
904 }
905
906 static void ntb_qp_link_work(struct work_struct *work)
907 {
908 struct ntb_transport_qp *qp = container_of(work,
909 struct ntb_transport_qp,
910 link_work.work);
911 struct pci_dev *pdev = qp->ndev->pdev;
912 struct ntb_transport_ctx *nt = qp->transport;
913 int val;
914
915 WARN_ON(!nt->link_is_up);
916
917 val = ntb_spad_read(nt->ndev, QP_LINKS);
918
919 ntb_peer_spad_write(nt->ndev, QP_LINKS, val | BIT(qp->qp_num));
920
921 /* query remote spad for qp ready bits */
922 ntb_peer_spad_read(nt->ndev, QP_LINKS);
923 dev_dbg_ratelimited(&pdev->dev, "Remote QP link status = %x\n", val);
924
925 /* See if the remote side is up */
926 if (val & BIT(qp->qp_num)) {
927 dev_info(&pdev->dev, "qp %d: Link Up\n", qp->qp_num);
928 qp->link_is_up = true;
929
930 if (qp->event_handler)
931 qp->event_handler(qp->cb_data, qp->link_is_up);
932
933 tasklet_schedule(&qp->rxc_db_work);
934 } else if (nt->link_is_up)
935 schedule_delayed_work(&qp->link_work,
936 msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
937 }
938
939 static int ntb_transport_init_queue(struct ntb_transport_ctx *nt,
940 unsigned int qp_num)
941 {
942 struct ntb_transport_qp *qp;
943 phys_addr_t mw_base;
944 resource_size_t mw_size;
945 unsigned int num_qps_mw, tx_size;
946 unsigned int mw_num, mw_count, qp_count;
947 u64 qp_offset;
948
949 mw_count = nt->mw_count;
950 qp_count = nt->qp_count;
951
952 mw_num = QP_TO_MW(nt, qp_num);
953
954 qp = &nt->qp_vec[qp_num];
955 qp->qp_num = qp_num;
956 qp->transport = nt;
957 qp->ndev = nt->ndev;
958 qp->client_ready = false;
959 qp->event_handler = NULL;
960 ntb_qp_link_down_reset(qp);
961
962 if (qp_count % mw_count && mw_num + 1 < qp_count / mw_count)
963 num_qps_mw = qp_count / mw_count + 1;
964 else
965 num_qps_mw = qp_count / mw_count;
966
967 mw_base = nt->mw_vec[mw_num].phys_addr;
968 mw_size = nt->mw_vec[mw_num].phys_size;
969
970 tx_size = (unsigned int)mw_size / num_qps_mw;
971 qp_offset = tx_size * (qp_num / mw_count);
972
973 qp->tx_mw = nt->mw_vec[mw_num].vbase + qp_offset;
974 if (!qp->tx_mw)
975 return -EINVAL;
976
977 qp->tx_mw_phys = mw_base + qp_offset;
978 if (!qp->tx_mw_phys)
979 return -EINVAL;
980
981 tx_size -= sizeof(struct ntb_rx_info);
982 qp->rx_info = qp->tx_mw + tx_size;
983
984 /* Due to housekeeping, there must be atleast 2 buffs */
985 qp->tx_max_frame = min(transport_mtu, tx_size / 2);
986 qp->tx_max_entry = tx_size / qp->tx_max_frame;
987
988 if (nt->debugfs_node_dir) {
989 char debugfs_name[4];
990
991 snprintf(debugfs_name, 4, "qp%d", qp_num);
992 qp->debugfs_dir = debugfs_create_dir(debugfs_name,
993 nt->debugfs_node_dir);
994
995 qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR,
996 qp->debugfs_dir, qp,
997 &ntb_qp_debugfs_stats);
998 } else {
999 qp->debugfs_dir = NULL;
1000 qp->debugfs_stats = NULL;
1001 }
1002
1003 INIT_DELAYED_WORK(&qp->link_work, ntb_qp_link_work);
1004 INIT_WORK(&qp->link_cleanup, ntb_qp_link_cleanup_work);
1005
1006 spin_lock_init(&qp->ntb_rx_q_lock);
1007 spin_lock_init(&qp->ntb_tx_free_q_lock);
1008
1009 INIT_LIST_HEAD(&qp->rx_post_q);
1010 INIT_LIST_HEAD(&qp->rx_pend_q);
1011 INIT_LIST_HEAD(&qp->rx_free_q);
1012 INIT_LIST_HEAD(&qp->tx_free_q);
1013
1014 tasklet_init(&qp->rxc_db_work, ntb_transport_rxc_db,
1015 (unsigned long)qp);
1016
1017 return 0;
1018 }
1019
1020 static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev)
1021 {
1022 struct ntb_transport_ctx *nt;
1023 struct ntb_transport_mw *mw;
1024 unsigned int mw_count, qp_count;
1025 u64 qp_bitmap;
1026 int node;
1027 int rc, i;
1028
1029 if (ntb_db_is_unsafe(ndev))
1030 dev_dbg(&ndev->dev,
1031 "doorbell is unsafe, proceed anyway...\n");
1032 if (ntb_spad_is_unsafe(ndev))
1033 dev_dbg(&ndev->dev,
1034 "scratchpad is unsafe, proceed anyway...\n");
1035
1036 node = dev_to_node(&ndev->dev);
1037
1038 nt = kzalloc_node(sizeof(*nt), GFP_KERNEL, node);
1039 if (!nt)
1040 return -ENOMEM;
1041
1042 nt->ndev = ndev;
1043
1044 mw_count = ntb_mw_count(ndev);
1045
1046 nt->mw_count = mw_count;
1047
1048 nt->mw_vec = kzalloc_node(mw_count * sizeof(*nt->mw_vec),
1049 GFP_KERNEL, node);
1050 if (!nt->mw_vec) {
1051 rc = -ENOMEM;
1052 goto err;
1053 }
1054
1055 for (i = 0; i < mw_count; i++) {
1056 mw = &nt->mw_vec[i];
1057
1058 rc = ntb_mw_get_range(ndev, i, &mw->phys_addr, &mw->phys_size,
1059 &mw->xlat_align, &mw->xlat_align_size);
1060 if (rc)
1061 goto err1;
1062
1063 mw->vbase = ioremap_wc(mw->phys_addr, mw->phys_size);
1064 if (!mw->vbase) {
1065 rc = -ENOMEM;
1066 goto err1;
1067 }
1068
1069 mw->buff_size = 0;
1070 mw->xlat_size = 0;
1071 mw->virt_addr = NULL;
1072 mw->dma_addr = 0;
1073 }
1074
1075 qp_bitmap = ntb_db_valid_mask(ndev);
1076
1077 qp_count = ilog2(qp_bitmap);
1078 if (max_num_clients && max_num_clients < qp_count)
1079 qp_count = max_num_clients;
1080 else if (mw_count < qp_count)
1081 qp_count = mw_count;
1082
1083 qp_bitmap &= BIT_ULL(qp_count) - 1;
1084
1085 nt->qp_count = qp_count;
1086 nt->qp_bitmap = qp_bitmap;
1087 nt->qp_bitmap_free = qp_bitmap;
1088
1089 nt->qp_vec = kzalloc_node(qp_count * sizeof(*nt->qp_vec),
1090 GFP_KERNEL, node);
1091 if (!nt->qp_vec) {
1092 rc = -ENOMEM;
1093 goto err1;
1094 }
1095
1096 if (nt_debugfs_dir) {
1097 nt->debugfs_node_dir =
1098 debugfs_create_dir(pci_name(ndev->pdev),
1099 nt_debugfs_dir);
1100 }
1101
1102 for (i = 0; i < qp_count; i++) {
1103 rc = ntb_transport_init_queue(nt, i);
1104 if (rc)
1105 goto err2;
1106 }
1107
1108 INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work);
1109 INIT_WORK(&nt->link_cleanup, ntb_transport_link_cleanup_work);
1110
1111 rc = ntb_set_ctx(ndev, nt, &ntb_transport_ops);
1112 if (rc)
1113 goto err2;
1114
1115 INIT_LIST_HEAD(&nt->client_devs);
1116 rc = ntb_bus_init(nt);
1117 if (rc)
1118 goto err3;
1119
1120 nt->link_is_up = false;
1121 ntb_link_enable(ndev, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
1122 ntb_link_event(ndev);
1123
1124 return 0;
1125
1126 err3:
1127 ntb_clear_ctx(ndev);
1128 err2:
1129 kfree(nt->qp_vec);
1130 err1:
1131 while (i--) {
1132 mw = &nt->mw_vec[i];
1133 iounmap(mw->vbase);
1134 }
1135 kfree(nt->mw_vec);
1136 err:
1137 kfree(nt);
1138 return rc;
1139 }
1140
1141 static void ntb_transport_free(struct ntb_client *self, struct ntb_dev *ndev)
1142 {
1143 struct ntb_transport_ctx *nt = ndev->ctx;
1144 struct ntb_transport_qp *qp;
1145 u64 qp_bitmap_alloc;
1146 int i;
1147
1148 ntb_transport_link_cleanup(nt);
1149 cancel_work_sync(&nt->link_cleanup);
1150 cancel_delayed_work_sync(&nt->link_work);
1151
1152 qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
1153
1154 /* verify that all the qp's are freed */
1155 for (i = 0; i < nt->qp_count; i++) {
1156 qp = &nt->qp_vec[i];
1157 if (qp_bitmap_alloc & BIT_ULL(i))
1158 ntb_transport_free_queue(qp);
1159 debugfs_remove_recursive(qp->debugfs_dir);
1160 }
1161
1162 ntb_link_disable(ndev);
1163 ntb_clear_ctx(ndev);
1164
1165 ntb_bus_remove(nt);
1166
1167 for (i = nt->mw_count; i--; ) {
1168 ntb_free_mw(nt, i);
1169 iounmap(nt->mw_vec[i].vbase);
1170 }
1171
1172 kfree(nt->qp_vec);
1173 kfree(nt->mw_vec);
1174 kfree(nt);
1175 }
1176
1177 static void ntb_complete_rxc(struct ntb_transport_qp *qp)
1178 {
1179 struct ntb_queue_entry *entry;
1180 void *cb_data;
1181 unsigned int len;
1182 unsigned long irqflags;
1183
1184 spin_lock_irqsave(&qp->ntb_rx_q_lock, irqflags);
1185
1186 while (!list_empty(&qp->rx_post_q)) {
1187 entry = list_first_entry(&qp->rx_post_q,
1188 struct ntb_queue_entry, entry);
1189 if (!(entry->flags & DESC_DONE_FLAG))
1190 break;
1191
1192 entry->rx_hdr->flags = 0;
1193 iowrite32(entry->index, &qp->rx_info->entry);
1194
1195 cb_data = entry->cb_data;
1196 len = entry->len;
1197
1198 list_move_tail(&entry->entry, &qp->rx_free_q);
1199
1200 spin_unlock_irqrestore(&qp->ntb_rx_q_lock, irqflags);
1201
1202 if (qp->rx_handler && qp->client_ready)
1203 qp->rx_handler(qp, qp->cb_data, cb_data, len);
1204
1205 spin_lock_irqsave(&qp->ntb_rx_q_lock, irqflags);
1206 }
1207
1208 spin_unlock_irqrestore(&qp->ntb_rx_q_lock, irqflags);
1209 }
1210
1211 static void ntb_rx_copy_callback(void *data)
1212 {
1213 struct ntb_queue_entry *entry = data;
1214
1215 entry->flags |= DESC_DONE_FLAG;
1216
1217 ntb_complete_rxc(entry->qp);
1218 }
1219
1220 static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void *offset)
1221 {
1222 void *buf = entry->buf;
1223 size_t len = entry->len;
1224
1225 memcpy(buf, offset, len);
1226
1227 /* Ensure that the data is fully copied out before clearing the flag */
1228 wmb();
1229
1230 ntb_rx_copy_callback(entry);
1231 }
1232
1233 static void ntb_async_rx(struct ntb_queue_entry *entry, void *offset)
1234 {
1235 struct dma_async_tx_descriptor *txd;
1236 struct ntb_transport_qp *qp = entry->qp;
1237 struct dma_chan *chan = qp->rx_dma_chan;
1238 struct dma_device *device;
1239 size_t pay_off, buff_off, len;
1240 struct dmaengine_unmap_data *unmap;
1241 dma_cookie_t cookie;
1242 void *buf = entry->buf;
1243 int retries = 0;
1244
1245 len = entry->len;
1246
1247 if (!chan)
1248 goto err;
1249
1250 if (len < copy_bytes)
1251 goto err;
1252
1253 device = chan->device;
1254 pay_off = (size_t)offset & ~PAGE_MASK;
1255 buff_off = (size_t)buf & ~PAGE_MASK;
1256
1257 if (!is_dma_copy_aligned(device, pay_off, buff_off, len))
1258 goto err;
1259
1260 unmap = dmaengine_get_unmap_data(device->dev, 2, GFP_NOWAIT);
1261 if (!unmap)
1262 goto err;
1263
1264 unmap->len = len;
1265 unmap->addr[0] = dma_map_page(device->dev, virt_to_page(offset),
1266 pay_off, len, DMA_TO_DEVICE);
1267 if (dma_mapping_error(device->dev, unmap->addr[0]))
1268 goto err_get_unmap;
1269
1270 unmap->to_cnt = 1;
1271
1272 unmap->addr[1] = dma_map_page(device->dev, virt_to_page(buf),
1273 buff_off, len, DMA_FROM_DEVICE);
1274 if (dma_mapping_error(device->dev, unmap->addr[1]))
1275 goto err_get_unmap;
1276
1277 unmap->from_cnt = 1;
1278
1279 for (retries = 0; retries < DMA_RETRIES; retries++) {
1280 txd = device->device_prep_dma_memcpy(chan, unmap->addr[1],
1281 unmap->addr[0], len,
1282 DMA_PREP_INTERRUPT);
1283 if (txd)
1284 break;
1285
1286 set_current_state(TASK_INTERRUPTIBLE);
1287 schedule_timeout(DMA_OUT_RESOURCE_TO);
1288 }
1289
1290 if (!txd) {
1291 qp->dma_rx_prep_err++;
1292 goto err_get_unmap;
1293 }
1294
1295 txd->callback = ntb_rx_copy_callback;
1296 txd->callback_param = entry;
1297 dma_set_unmap(txd, unmap);
1298
1299 cookie = dmaengine_submit(txd);
1300 if (dma_submit_error(cookie))
1301 goto err_set_unmap;
1302
1303 dmaengine_unmap_put(unmap);
1304
1305 qp->last_cookie = cookie;
1306
1307 qp->rx_async++;
1308
1309 return;
1310
1311 err_set_unmap:
1312 dmaengine_unmap_put(unmap);
1313 err_get_unmap:
1314 dmaengine_unmap_put(unmap);
1315 err:
1316 ntb_memcpy_rx(entry, offset);
1317 qp->rx_memcpy++;
1318 }
1319
1320 static int ntb_process_rxc(struct ntb_transport_qp *qp)
1321 {
1322 struct ntb_payload_header *hdr;
1323 struct ntb_queue_entry *entry;
1324 void *offset;
1325
1326 offset = qp->rx_buff + qp->rx_max_frame * qp->rx_index;
1327 hdr = offset + qp->rx_max_frame - sizeof(struct ntb_payload_header);
1328
1329 dev_dbg(&qp->ndev->pdev->dev, "qp %d: RX ver %u len %d flags %x\n",
1330 qp->qp_num, hdr->ver, hdr->len, hdr->flags);
1331
1332 if (!(hdr->flags & DESC_DONE_FLAG)) {
1333 dev_dbg(&qp->ndev->pdev->dev, "done flag not set\n");
1334 qp->rx_ring_empty++;
1335 return -EAGAIN;
1336 }
1337
1338 if (hdr->flags & LINK_DOWN_FLAG) {
1339 dev_dbg(&qp->ndev->pdev->dev, "link down flag set\n");
1340 ntb_qp_link_down(qp);
1341 hdr->flags = 0;
1342 return -EAGAIN;
1343 }
1344
1345 if (hdr->ver != (u32)qp->rx_pkts) {
1346 dev_dbg(&qp->ndev->pdev->dev,
1347 "version mismatch, expected %llu - got %u\n",
1348 qp->rx_pkts, hdr->ver);
1349 qp->rx_err_ver++;
1350 return -EIO;
1351 }
1352
1353 entry = ntb_list_mv(&qp->ntb_rx_q_lock, &qp->rx_pend_q, &qp->rx_post_q);
1354 if (!entry) {
1355 dev_dbg(&qp->ndev->pdev->dev, "no receive buffer\n");
1356 qp->rx_err_no_buf++;
1357 return -EAGAIN;
1358 }
1359
1360 entry->rx_hdr = hdr;
1361 entry->index = qp->rx_index;
1362
1363 if (hdr->len > entry->len) {
1364 dev_dbg(&qp->ndev->pdev->dev,
1365 "receive buffer overflow! Wanted %d got %d\n",
1366 hdr->len, entry->len);
1367 qp->rx_err_oflow++;
1368
1369 entry->len = -EIO;
1370 entry->flags |= DESC_DONE_FLAG;
1371
1372 ntb_complete_rxc(qp);
1373 } else {
1374 dev_dbg(&qp->ndev->pdev->dev,
1375 "RX OK index %u ver %u size %d into buf size %d\n",
1376 qp->rx_index, hdr->ver, hdr->len, entry->len);
1377
1378 qp->rx_bytes += hdr->len;
1379 qp->rx_pkts++;
1380
1381 entry->len = hdr->len;
1382
1383 ntb_async_rx(entry, offset);
1384 }
1385
1386 qp->rx_index++;
1387 qp->rx_index %= qp->rx_max_entry;
1388
1389 return 0;
1390 }
1391
1392 static void ntb_transport_rxc_db(unsigned long data)
1393 {
1394 struct ntb_transport_qp *qp = (void *)data;
1395 int rc, i;
1396
1397 dev_dbg(&qp->ndev->pdev->dev, "%s: doorbell %d received\n",
1398 __func__, qp->qp_num);
1399
1400 /* Limit the number of packets processed in a single interrupt to
1401 * provide fairness to others
1402 */
1403 for (i = 0; i < qp->rx_max_entry; i++) {
1404 rc = ntb_process_rxc(qp);
1405 if (rc)
1406 break;
1407 }
1408
1409 if (i && qp->rx_dma_chan)
1410 dma_async_issue_pending(qp->rx_dma_chan);
1411
1412 if (i == qp->rx_max_entry) {
1413 /* there is more work to do */
1414 tasklet_schedule(&qp->rxc_db_work);
1415 } else if (ntb_db_read(qp->ndev) & BIT_ULL(qp->qp_num)) {
1416 /* the doorbell bit is set: clear it */
1417 ntb_db_clear(qp->ndev, BIT_ULL(qp->qp_num));
1418 /* ntb_db_read ensures ntb_db_clear write is committed */
1419 ntb_db_read(qp->ndev);
1420
1421 /* an interrupt may have arrived between finishing
1422 * ntb_process_rxc and clearing the doorbell bit:
1423 * there might be some more work to do.
1424 */
1425 tasklet_schedule(&qp->rxc_db_work);
1426 }
1427 }
1428
1429 static void ntb_tx_copy_callback(void *data)
1430 {
1431 struct ntb_queue_entry *entry = data;
1432 struct ntb_transport_qp *qp = entry->qp;
1433 struct ntb_payload_header __iomem *hdr = entry->tx_hdr;
1434
1435 iowrite32(entry->flags | DESC_DONE_FLAG, &hdr->flags);
1436
1437 ntb_peer_db_set(qp->ndev, BIT_ULL(qp->qp_num));
1438
1439 /* The entry length can only be zero if the packet is intended to be a
1440 * "link down" or similar. Since no payload is being sent in these
1441 * cases, there is nothing to add to the completion queue.
1442 */
1443 if (entry->len > 0) {
1444 qp->tx_bytes += entry->len;
1445
1446 if (qp->tx_handler)
1447 qp->tx_handler(qp, qp->cb_data, entry->cb_data,
1448 entry->len);
1449 }
1450
1451 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q);
1452 }
1453
1454 static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset)
1455 {
1456 #ifdef ARCH_HAS_NOCACHE_UACCESS
1457 /*
1458 * Using non-temporal mov to improve performance on non-cached
1459 * writes, even though we aren't actually copying from user space.
1460 */
1461 __copy_from_user_inatomic_nocache(offset, entry->buf, entry->len);
1462 #else
1463 memcpy_toio(offset, entry->buf, entry->len);
1464 #endif
1465
1466 /* Ensure that the data is fully copied out before setting the flags */
1467 wmb();
1468
1469 ntb_tx_copy_callback(entry);
1470 }
1471
1472 static void ntb_async_tx(struct ntb_transport_qp *qp,
1473 struct ntb_queue_entry *entry)
1474 {
1475 struct ntb_payload_header __iomem *hdr;
1476 struct dma_async_tx_descriptor *txd;
1477 struct dma_chan *chan = qp->tx_dma_chan;
1478 struct dma_device *device;
1479 size_t dest_off, buff_off;
1480 struct dmaengine_unmap_data *unmap;
1481 dma_addr_t dest;
1482 dma_cookie_t cookie;
1483 void __iomem *offset;
1484 size_t len = entry->len;
1485 void *buf = entry->buf;
1486 int retries = 0;
1487
1488 offset = qp->tx_mw + qp->tx_max_frame * qp->tx_index;
1489 hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
1490 entry->tx_hdr = hdr;
1491
1492 iowrite32(entry->len, &hdr->len);
1493 iowrite32((u32)qp->tx_pkts, &hdr->ver);
1494
1495 if (!chan)
1496 goto err;
1497
1498 if (len < copy_bytes)
1499 goto err;
1500
1501 device = chan->device;
1502 dest = qp->tx_mw_phys + qp->tx_max_frame * qp->tx_index;
1503 buff_off = (size_t)buf & ~PAGE_MASK;
1504 dest_off = (size_t)dest & ~PAGE_MASK;
1505
1506 if (!is_dma_copy_aligned(device, buff_off, dest_off, len))
1507 goto err;
1508
1509 unmap = dmaengine_get_unmap_data(device->dev, 1, GFP_NOWAIT);
1510 if (!unmap)
1511 goto err;
1512
1513 unmap->len = len;
1514 unmap->addr[0] = dma_map_page(device->dev, virt_to_page(buf),
1515 buff_off, len, DMA_TO_DEVICE);
1516 if (dma_mapping_error(device->dev, unmap->addr[0]))
1517 goto err_get_unmap;
1518
1519 unmap->to_cnt = 1;
1520
1521 for (retries = 0; retries < DMA_RETRIES; retries++) {
1522 txd = device->device_prep_dma_memcpy(chan, dest, unmap->addr[0],
1523 len, DMA_PREP_INTERRUPT);
1524 if (txd)
1525 break;
1526
1527 set_current_state(TASK_INTERRUPTIBLE);
1528 schedule_timeout(DMA_OUT_RESOURCE_TO);
1529 }
1530
1531 if (!txd) {
1532 qp->dma_tx_prep_err++;
1533 goto err_get_unmap;
1534 }
1535
1536 txd->callback = ntb_tx_copy_callback;
1537 txd->callback_param = entry;
1538 dma_set_unmap(txd, unmap);
1539
1540 cookie = dmaengine_submit(txd);
1541 if (dma_submit_error(cookie))
1542 goto err_set_unmap;
1543
1544 dmaengine_unmap_put(unmap);
1545
1546 dma_async_issue_pending(chan);
1547 qp->tx_async++;
1548
1549 return;
1550 err_set_unmap:
1551 dmaengine_unmap_put(unmap);
1552 err_get_unmap:
1553 dmaengine_unmap_put(unmap);
1554 err:
1555 ntb_memcpy_tx(entry, offset);
1556 qp->tx_memcpy++;
1557 }
1558
1559 static int ntb_process_tx(struct ntb_transport_qp *qp,
1560 struct ntb_queue_entry *entry)
1561 {
1562 if (qp->tx_index == qp->remote_rx_info->entry) {
1563 qp->tx_ring_full++;
1564 return -EAGAIN;
1565 }
1566
1567 if (entry->len > qp->tx_max_frame - sizeof(struct ntb_payload_header)) {
1568 if (qp->tx_handler)
1569 qp->tx_handler(qp, qp->cb_data, NULL, -EIO);
1570
1571 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1572 &qp->tx_free_q);
1573 return 0;
1574 }
1575
1576 ntb_async_tx(qp, entry);
1577
1578 qp->tx_index++;
1579 qp->tx_index %= qp->tx_max_entry;
1580
1581 qp->tx_pkts++;
1582
1583 return 0;
1584 }
1585
1586 static void ntb_send_link_down(struct ntb_transport_qp *qp)
1587 {
1588 struct pci_dev *pdev = qp->ndev->pdev;
1589 struct ntb_queue_entry *entry;
1590 int i, rc;
1591
1592 if (!qp->link_is_up)
1593 return;
1594
1595 dev_info(&pdev->dev, "qp %d: Send Link Down\n", qp->qp_num);
1596
1597 for (i = 0; i < NTB_LINK_DOWN_TIMEOUT; i++) {
1598 entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1599 if (entry)
1600 break;
1601 msleep(100);
1602 }
1603
1604 if (!entry)
1605 return;
1606
1607 entry->cb_data = NULL;
1608 entry->buf = NULL;
1609 entry->len = 0;
1610 entry->flags = LINK_DOWN_FLAG;
1611
1612 rc = ntb_process_tx(qp, entry);
1613 if (rc)
1614 dev_err(&pdev->dev, "ntb: QP%d unable to send linkdown msg\n",
1615 qp->qp_num);
1616
1617 ntb_qp_link_down_reset(qp);
1618 }
1619
1620 static bool ntb_dma_filter_fn(struct dma_chan *chan, void *node)
1621 {
1622 return dev_to_node(&chan->dev->device) == (int)(unsigned long)node;
1623 }
1624
1625 /**
1626 * ntb_transport_create_queue - Create a new NTB transport layer queue
1627 * @rx_handler: receive callback function
1628 * @tx_handler: transmit callback function
1629 * @event_handler: event callback function
1630 *
1631 * Create a new NTB transport layer queue and provide the queue with a callback
1632 * routine for both transmit and receive. The receive callback routine will be
1633 * used to pass up data when the transport has received it on the queue. The
1634 * transmit callback routine will be called when the transport has completed the
1635 * transmission of the data on the queue and the data is ready to be freed.
1636 *
1637 * RETURNS: pointer to newly created ntb_queue, NULL on error.
1638 */
1639 struct ntb_transport_qp *
1640 ntb_transport_create_queue(void *data, struct device *client_dev,
1641 const struct ntb_queue_handlers *handlers)
1642 {
1643 struct ntb_dev *ndev;
1644 struct pci_dev *pdev;
1645 struct ntb_transport_ctx *nt;
1646 struct ntb_queue_entry *entry;
1647 struct ntb_transport_qp *qp;
1648 u64 qp_bit;
1649 unsigned int free_queue;
1650 dma_cap_mask_t dma_mask;
1651 int node;
1652 int i;
1653
1654 ndev = dev_ntb(client_dev->parent);
1655 pdev = ndev->pdev;
1656 nt = ndev->ctx;
1657
1658 node = dev_to_node(&ndev->dev);
1659
1660 free_queue = ffs(nt->qp_bitmap);
1661 if (!free_queue)
1662 goto err;
1663
1664 /* decrement free_queue to make it zero based */
1665 free_queue--;
1666
1667 qp = &nt->qp_vec[free_queue];
1668 qp_bit = BIT_ULL(qp->qp_num);
1669
1670 nt->qp_bitmap_free &= ~qp_bit;
1671
1672 qp->cb_data = data;
1673 qp->rx_handler = handlers->rx_handler;
1674 qp->tx_handler = handlers->tx_handler;
1675 qp->event_handler = handlers->event_handler;
1676
1677 dma_cap_zero(dma_mask);
1678 dma_cap_set(DMA_MEMCPY, dma_mask);
1679
1680 if (use_dma) {
1681 qp->tx_dma_chan =
1682 dma_request_channel(dma_mask, ntb_dma_filter_fn,
1683 (void *)(unsigned long)node);
1684 if (!qp->tx_dma_chan)
1685 dev_info(&pdev->dev, "Unable to allocate TX DMA channel\n");
1686
1687 qp->rx_dma_chan =
1688 dma_request_channel(dma_mask, ntb_dma_filter_fn,
1689 (void *)(unsigned long)node);
1690 if (!qp->rx_dma_chan)
1691 dev_info(&pdev->dev, "Unable to allocate RX DMA channel\n");
1692 } else {
1693 qp->tx_dma_chan = NULL;
1694 qp->rx_dma_chan = NULL;
1695 }
1696
1697 dev_dbg(&pdev->dev, "Using %s memcpy for TX\n",
1698 qp->tx_dma_chan ? "DMA" : "CPU");
1699
1700 dev_dbg(&pdev->dev, "Using %s memcpy for RX\n",
1701 qp->rx_dma_chan ? "DMA" : "CPU");
1702
1703 for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
1704 entry = kzalloc_node(sizeof(*entry), GFP_ATOMIC, node);
1705 if (!entry)
1706 goto err1;
1707
1708 entry->qp = qp;
1709 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry,
1710 &qp->rx_free_q);
1711 }
1712
1713 for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
1714 entry = kzalloc_node(sizeof(*entry), GFP_ATOMIC, node);
1715 if (!entry)
1716 goto err2;
1717
1718 entry->qp = qp;
1719 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1720 &qp->tx_free_q);
1721 }
1722
1723 ntb_db_clear(qp->ndev, qp_bit);
1724 ntb_db_clear_mask(qp->ndev, qp_bit);
1725
1726 dev_info(&pdev->dev, "NTB Transport QP %d created\n", qp->qp_num);
1727
1728 return qp;
1729
1730 err2:
1731 while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1732 kfree(entry);
1733 err1:
1734 while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
1735 kfree(entry);
1736 if (qp->tx_dma_chan)
1737 dma_release_channel(qp->tx_dma_chan);
1738 if (qp->rx_dma_chan)
1739 dma_release_channel(qp->rx_dma_chan);
1740 nt->qp_bitmap_free |= qp_bit;
1741 err:
1742 return NULL;
1743 }
1744 EXPORT_SYMBOL_GPL(ntb_transport_create_queue);
1745
1746 /**
1747 * ntb_transport_free_queue - Frees NTB transport queue
1748 * @qp: NTB queue to be freed
1749 *
1750 * Frees NTB transport queue
1751 */
1752 void ntb_transport_free_queue(struct ntb_transport_qp *qp)
1753 {
1754 struct pci_dev *pdev;
1755 struct ntb_queue_entry *entry;
1756 u64 qp_bit;
1757
1758 if (!qp)
1759 return;
1760
1761 pdev = qp->ndev->pdev;
1762
1763 if (qp->tx_dma_chan) {
1764 struct dma_chan *chan = qp->tx_dma_chan;
1765 /* Putting the dma_chan to NULL will force any new traffic to be
1766 * processed by the CPU instead of the DAM engine
1767 */
1768 qp->tx_dma_chan = NULL;
1769
1770 /* Try to be nice and wait for any queued DMA engine
1771 * transactions to process before smashing it with a rock
1772 */
1773 dma_sync_wait(chan, qp->last_cookie);
1774 dmaengine_terminate_all(chan);
1775 dma_release_channel(chan);
1776 }
1777
1778 if (qp->rx_dma_chan) {
1779 struct dma_chan *chan = qp->rx_dma_chan;
1780 /* Putting the dma_chan to NULL will force any new traffic to be
1781 * processed by the CPU instead of the DAM engine
1782 */
1783 qp->rx_dma_chan = NULL;
1784
1785 /* Try to be nice and wait for any queued DMA engine
1786 * transactions to process before smashing it with a rock
1787 */
1788 dma_sync_wait(chan, qp->last_cookie);
1789 dmaengine_terminate_all(chan);
1790 dma_release_channel(chan);
1791 }
1792
1793 qp_bit = BIT_ULL(qp->qp_num);
1794
1795 ntb_db_set_mask(qp->ndev, qp_bit);
1796 tasklet_disable(&qp->rxc_db_work);
1797
1798 cancel_delayed_work_sync(&qp->link_work);
1799
1800 qp->cb_data = NULL;
1801 qp->rx_handler = NULL;
1802 qp->tx_handler = NULL;
1803 qp->event_handler = NULL;
1804
1805 while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
1806 kfree(entry);
1807
1808 while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_pend_q))) {
1809 dev_warn(&pdev->dev, "Freeing item from non-empty rx_pend_q\n");
1810 kfree(entry);
1811 }
1812
1813 while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_post_q))) {
1814 dev_warn(&pdev->dev, "Freeing item from non-empty rx_post_q\n");
1815 kfree(entry);
1816 }
1817
1818 while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1819 kfree(entry);
1820
1821 qp->transport->qp_bitmap_free |= qp_bit;
1822
1823 dev_info(&pdev->dev, "NTB Transport QP %d freed\n", qp->qp_num);
1824 }
1825 EXPORT_SYMBOL_GPL(ntb_transport_free_queue);
1826
1827 /**
1828 * ntb_transport_rx_remove - Dequeues enqueued rx packet
1829 * @qp: NTB queue to be freed
1830 * @len: pointer to variable to write enqueued buffers length
1831 *
1832 * Dequeues unused buffers from receive queue. Should only be used during
1833 * shutdown of qp.
1834 *
1835 * RETURNS: NULL error value on error, or void* for success.
1836 */
1837 void *ntb_transport_rx_remove(struct ntb_transport_qp *qp, unsigned int *len)
1838 {
1839 struct ntb_queue_entry *entry;
1840 void *buf;
1841
1842 if (!qp || qp->client_ready)
1843 return NULL;
1844
1845 entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_pend_q);
1846 if (!entry)
1847 return NULL;
1848
1849 buf = entry->cb_data;
1850 *len = entry->len;
1851
1852 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_free_q);
1853
1854 return buf;
1855 }
1856 EXPORT_SYMBOL_GPL(ntb_transport_rx_remove);
1857
1858 /**
1859 * ntb_transport_rx_enqueue - Enqueue a new NTB queue entry
1860 * @qp: NTB transport layer queue the entry is to be enqueued on
1861 * @cb: per buffer pointer for callback function to use
1862 * @data: pointer to data buffer that incoming packets will be copied into
1863 * @len: length of the data buffer
1864 *
1865 * Enqueue a new receive buffer onto the transport queue into which a NTB
1866 * payload can be received into.
1867 *
1868 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
1869 */
1870 int ntb_transport_rx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
1871 unsigned int len)
1872 {
1873 struct ntb_queue_entry *entry;
1874
1875 if (!qp)
1876 return -EINVAL;
1877
1878 entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q);
1879 if (!entry)
1880 return -ENOMEM;
1881
1882 entry->cb_data = cb;
1883 entry->buf = data;
1884 entry->len = len;
1885 entry->flags = 0;
1886
1887 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_pend_q);
1888
1889 tasklet_schedule(&qp->rxc_db_work);
1890
1891 return 0;
1892 }
1893 EXPORT_SYMBOL_GPL(ntb_transport_rx_enqueue);
1894
1895 /**
1896 * ntb_transport_tx_enqueue - Enqueue a new NTB queue entry
1897 * @qp: NTB transport layer queue the entry is to be enqueued on
1898 * @cb: per buffer pointer for callback function to use
1899 * @data: pointer to data buffer that will be sent
1900 * @len: length of the data buffer
1901 *
1902 * Enqueue a new transmit buffer onto the transport queue from which a NTB
1903 * payload will be transmitted. This assumes that a lock is being held to
1904 * serialize access to the qp.
1905 *
1906 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
1907 */
1908 int ntb_transport_tx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
1909 unsigned int len)
1910 {
1911 struct ntb_queue_entry *entry;
1912 int rc;
1913
1914 if (!qp || !qp->link_is_up || !len)
1915 return -EINVAL;
1916
1917 entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1918 if (!entry) {
1919 qp->tx_err_no_buf++;
1920 return -EBUSY;
1921 }
1922
1923 entry->cb_data = cb;
1924 entry->buf = data;
1925 entry->len = len;
1926 entry->flags = 0;
1927
1928 rc = ntb_process_tx(qp, entry);
1929 if (rc)
1930 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1931 &qp->tx_free_q);
1932
1933 return rc;
1934 }
1935 EXPORT_SYMBOL_GPL(ntb_transport_tx_enqueue);
1936
1937 /**
1938 * ntb_transport_link_up - Notify NTB transport of client readiness to use queue
1939 * @qp: NTB transport layer queue to be enabled
1940 *
1941 * Notify NTB transport layer of client readiness to use queue
1942 */
1943 void ntb_transport_link_up(struct ntb_transport_qp *qp)
1944 {
1945 if (!qp)
1946 return;
1947
1948 qp->client_ready = true;
1949
1950 if (qp->transport->link_is_up)
1951 schedule_delayed_work(&qp->link_work, 0);
1952 }
1953 EXPORT_SYMBOL_GPL(ntb_transport_link_up);
1954
1955 /**
1956 * ntb_transport_link_down - Notify NTB transport to no longer enqueue data
1957 * @qp: NTB transport layer queue to be disabled
1958 *
1959 * Notify NTB transport layer of client's desire to no longer receive data on
1960 * transport queue specified. It is the client's responsibility to ensure all
1961 * entries on queue are purged or otherwise handled appropriately.
1962 */
1963 void ntb_transport_link_down(struct ntb_transport_qp *qp)
1964 {
1965 int val;
1966
1967 if (!qp)
1968 return;
1969
1970 qp->client_ready = false;
1971
1972 val = ntb_spad_read(qp->ndev, QP_LINKS);
1973
1974 ntb_peer_spad_write(qp->ndev, QP_LINKS,
1975 val & ~BIT(qp->qp_num));
1976
1977 if (qp->link_is_up)
1978 ntb_send_link_down(qp);
1979 else
1980 cancel_delayed_work_sync(&qp->link_work);
1981 }
1982 EXPORT_SYMBOL_GPL(ntb_transport_link_down);
1983
1984 /**
1985 * ntb_transport_link_query - Query transport link state
1986 * @qp: NTB transport layer queue to be queried
1987 *
1988 * Query connectivity to the remote system of the NTB transport queue
1989 *
1990 * RETURNS: true for link up or false for link down
1991 */
1992 bool ntb_transport_link_query(struct ntb_transport_qp *qp)
1993 {
1994 if (!qp)
1995 return false;
1996
1997 return qp->link_is_up;
1998 }
1999 EXPORT_SYMBOL_GPL(ntb_transport_link_query);
2000
2001 /**
2002 * ntb_transport_qp_num - Query the qp number
2003 * @qp: NTB transport layer queue to be queried
2004 *
2005 * Query qp number of the NTB transport queue
2006 *
2007 * RETURNS: a zero based number specifying the qp number
2008 */
2009 unsigned char ntb_transport_qp_num(struct ntb_transport_qp *qp)
2010 {
2011 if (!qp)
2012 return 0;
2013
2014 return qp->qp_num;
2015 }
2016 EXPORT_SYMBOL_GPL(ntb_transport_qp_num);
2017
2018 /**
2019 * ntb_transport_max_size - Query the max payload size of a qp
2020 * @qp: NTB transport layer queue to be queried
2021 *
2022 * Query the maximum payload size permissible on the given qp
2023 *
2024 * RETURNS: the max payload size of a qp
2025 */
2026 unsigned int ntb_transport_max_size(struct ntb_transport_qp *qp)
2027 {
2028 unsigned int max_size;
2029 unsigned int copy_align;
2030 struct dma_chan *rx_chan, *tx_chan;
2031
2032 if (!qp)
2033 return 0;
2034
2035 rx_chan = qp->rx_dma_chan;
2036 tx_chan = qp->tx_dma_chan;
2037
2038 copy_align = max(rx_chan ? rx_chan->device->copy_align : 0,
2039 tx_chan ? tx_chan->device->copy_align : 0);
2040
2041 /* If DMA engine usage is possible, try to find the max size for that */
2042 max_size = qp->tx_max_frame - sizeof(struct ntb_payload_header);
2043 max_size = round_down(max_size, 1 << copy_align);
2044
2045 return max_size;
2046 }
2047 EXPORT_SYMBOL_GPL(ntb_transport_max_size);
2048
2049 unsigned int ntb_transport_tx_free_entry(struct ntb_transport_qp *qp)
2050 {
2051 unsigned int head = qp->tx_index;
2052 unsigned int tail = qp->remote_rx_info->entry;
2053
2054 return tail > head ? tail - head : qp->tx_max_entry + tail - head;
2055 }
2056 EXPORT_SYMBOL_GPL(ntb_transport_tx_free_entry);
2057
2058 static void ntb_transport_doorbell_callback(void *data, int vector)
2059 {
2060 struct ntb_transport_ctx *nt = data;
2061 struct ntb_transport_qp *qp;
2062 u64 db_bits;
2063 unsigned int qp_num;
2064
2065 db_bits = (nt->qp_bitmap & ~nt->qp_bitmap_free &
2066 ntb_db_vector_mask(nt->ndev, vector));
2067
2068 while (db_bits) {
2069 qp_num = __ffs(db_bits);
2070 qp = &nt->qp_vec[qp_num];
2071
2072 tasklet_schedule(&qp->rxc_db_work);
2073
2074 db_bits &= ~BIT_ULL(qp_num);
2075 }
2076 }
2077
2078 static const struct ntb_ctx_ops ntb_transport_ops = {
2079 .link_event = ntb_transport_event_callback,
2080 .db_event = ntb_transport_doorbell_callback,
2081 };
2082
2083 static struct ntb_client ntb_transport_client = {
2084 .ops = {
2085 .probe = ntb_transport_probe,
2086 .remove = ntb_transport_free,
2087 },
2088 };
2089
2090 static int __init ntb_transport_init(void)
2091 {
2092 int rc;
2093
2094 pr_info("%s, version %s\n", NTB_TRANSPORT_DESC, NTB_TRANSPORT_VER);
2095
2096 if (debugfs_initialized())
2097 nt_debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
2098
2099 rc = bus_register(&ntb_transport_bus);
2100 if (rc)
2101 goto err_bus;
2102
2103 rc = ntb_register_client(&ntb_transport_client);
2104 if (rc)
2105 goto err_client;
2106
2107 return 0;
2108
2109 err_client:
2110 bus_unregister(&ntb_transport_bus);
2111 err_bus:
2112 debugfs_remove_recursive(nt_debugfs_dir);
2113 return rc;
2114 }
2115 module_init(ntb_transport_init);
2116
2117 static void __exit ntb_transport_exit(void)
2118 {
2119 debugfs_remove_recursive(nt_debugfs_dir);
2120
2121 ntb_unregister_client(&ntb_transport_client);
2122 bus_unregister(&ntb_transport_bus);
2123 }
2124 module_exit(ntb_transport_exit);
Linux kernel - Deliverables
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