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Restartable sequences: tests: introduce simple rseq start/finish
[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 bool active;
128
129 u8 qp_num; /* Only 64 QP's are allowed. 0-63 */
130 u64 qp_bit;
131
132 struct ntb_rx_info __iomem *rx_info;
133 struct ntb_rx_info *remote_rx_info;
134
135 void (*tx_handler)(struct ntb_transport_qp *qp, void *qp_data,
136 void *data, int len);
137 struct list_head tx_free_q;
138 spinlock_t ntb_tx_free_q_lock;
139 void __iomem *tx_mw;
140 dma_addr_t tx_mw_phys;
141 unsigned int tx_index;
142 unsigned int tx_max_entry;
143 unsigned int tx_max_frame;
144
145 void (*rx_handler)(struct ntb_transport_qp *qp, void *qp_data,
146 void *data, int len);
147 struct list_head rx_post_q;
148 struct list_head rx_pend_q;
149 struct list_head rx_free_q;
150 /* ntb_rx_q_lock: synchronize access to rx_XXXX_q */
151 spinlock_t ntb_rx_q_lock;
152 void *rx_buff;
153 unsigned int rx_index;
154 unsigned int rx_max_entry;
155 unsigned int rx_max_frame;
156 unsigned int rx_alloc_entry;
157 dma_cookie_t last_cookie;
158 struct tasklet_struct rxc_db_work;
159
160 void (*event_handler)(void *data, int status);
161 struct delayed_work link_work;
162 struct work_struct link_cleanup;
163
164 struct dentry *debugfs_dir;
165 struct dentry *debugfs_stats;
166
167 /* Stats */
168 u64 rx_bytes;
169 u64 rx_pkts;
170 u64 rx_ring_empty;
171 u64 rx_err_no_buf;
172 u64 rx_err_oflow;
173 u64 rx_err_ver;
174 u64 rx_memcpy;
175 u64 rx_async;
176 u64 dma_rx_prep_err;
177 u64 tx_bytes;
178 u64 tx_pkts;
179 u64 tx_ring_full;
180 u64 tx_err_no_buf;
181 u64 tx_memcpy;
182 u64 tx_async;
183 u64 dma_tx_prep_err;
184 };
185
186 struct ntb_transport_mw {
187 phys_addr_t phys_addr;
188 resource_size_t phys_size;
189 resource_size_t xlat_align;
190 resource_size_t xlat_align_size;
191 void __iomem *vbase;
192 size_t xlat_size;
193 size_t buff_size;
194 void *virt_addr;
195 dma_addr_t dma_addr;
196 };
197
198 struct ntb_transport_client_dev {
199 struct list_head entry;
200 struct ntb_transport_ctx *nt;
201 struct device dev;
202 };
203
204 struct ntb_transport_ctx {
205 struct list_head entry;
206 struct list_head client_devs;
207
208 struct ntb_dev *ndev;
209
210 struct ntb_transport_mw *mw_vec;
211 struct ntb_transport_qp *qp_vec;
212 unsigned int mw_count;
213 unsigned int qp_count;
214 u64 qp_bitmap;
215 u64 qp_bitmap_free;
216
217 bool link_is_up;
218 struct delayed_work link_work;
219 struct work_struct link_cleanup;
220
221 struct dentry *debugfs_node_dir;
222 };
223
224 enum {
225 DESC_DONE_FLAG = BIT(0),
226 LINK_DOWN_FLAG = BIT(1),
227 };
228
229 struct ntb_payload_header {
230 unsigned int ver;
231 unsigned int len;
232 unsigned int flags;
233 };
234
235 enum {
236 VERSION = 0,
237 QP_LINKS,
238 NUM_QPS,
239 NUM_MWS,
240 MW0_SZ_HIGH,
241 MW0_SZ_LOW,
242 MW1_SZ_HIGH,
243 MW1_SZ_LOW,
244 MAX_SPAD,
245 };
246
247 #define dev_client_dev(__dev) \
248 container_of((__dev), struct ntb_transport_client_dev, dev)
249
250 #define drv_client(__drv) \
251 container_of((__drv), struct ntb_transport_client, driver)
252
253 #define QP_TO_MW(nt, qp) ((qp) % nt->mw_count)
254 #define NTB_QP_DEF_NUM_ENTRIES 100
255 #define NTB_LINK_DOWN_TIMEOUT 10
256 #define DMA_RETRIES 20
257 #define DMA_OUT_RESOURCE_TO 50
258
259 static void ntb_transport_rxc_db(unsigned long data);
260 static const struct ntb_ctx_ops ntb_transport_ops;
261 static struct ntb_client ntb_transport_client;
262
263 static int ntb_transport_bus_match(struct device *dev,
264 struct device_driver *drv)
265 {
266 return !strncmp(dev_name(dev), drv->name, strlen(drv->name));
267 }
268
269 static int ntb_transport_bus_probe(struct device *dev)
270 {
271 const struct ntb_transport_client *client;
272 int rc = -EINVAL;
273
274 get_device(dev);
275
276 client = drv_client(dev->driver);
277 rc = client->probe(dev);
278 if (rc)
279 put_device(dev);
280
281 return rc;
282 }
283
284 static int ntb_transport_bus_remove(struct device *dev)
285 {
286 const struct ntb_transport_client *client;
287
288 client = drv_client(dev->driver);
289 client->remove(dev);
290
291 put_device(dev);
292
293 return 0;
294 }
295
296 static struct bus_type ntb_transport_bus = {
297 .name = "ntb_transport",
298 .match = ntb_transport_bus_match,
299 .probe = ntb_transport_bus_probe,
300 .remove = ntb_transport_bus_remove,
301 };
302
303 static LIST_HEAD(ntb_transport_list);
304
305 static int ntb_bus_init(struct ntb_transport_ctx *nt)
306 {
307 list_add_tail(&nt->entry, &ntb_transport_list);
308 return 0;
309 }
310
311 static void ntb_bus_remove(struct ntb_transport_ctx *nt)
312 {
313 struct ntb_transport_client_dev *client_dev, *cd;
314
315 list_for_each_entry_safe(client_dev, cd, &nt->client_devs, entry) {
316 dev_err(client_dev->dev.parent, "%s still attached to bus, removing\n",
317 dev_name(&client_dev->dev));
318 list_del(&client_dev->entry);
319 device_unregister(&client_dev->dev);
320 }
321
322 list_del(&nt->entry);
323 }
324
325 static void ntb_transport_client_release(struct device *dev)
326 {
327 struct ntb_transport_client_dev *client_dev;
328
329 client_dev = dev_client_dev(dev);
330 kfree(client_dev);
331 }
332
333 /**
334 * ntb_transport_unregister_client_dev - Unregister NTB client device
335 * @device_name: Name of NTB client device
336 *
337 * Unregister an NTB client device with the NTB transport layer
338 */
339 void ntb_transport_unregister_client_dev(char *device_name)
340 {
341 struct ntb_transport_client_dev *client, *cd;
342 struct ntb_transport_ctx *nt;
343
344 list_for_each_entry(nt, &ntb_transport_list, entry)
345 list_for_each_entry_safe(client, cd, &nt->client_devs, entry)
346 if (!strncmp(dev_name(&client->dev), device_name,
347 strlen(device_name))) {
348 list_del(&client->entry);
349 device_unregister(&client->dev);
350 }
351 }
352 EXPORT_SYMBOL_GPL(ntb_transport_unregister_client_dev);
353
354 /**
355 * ntb_transport_register_client_dev - Register NTB client device
356 * @device_name: Name of NTB client device
357 *
358 * Register an NTB client device with the NTB transport layer
359 */
360 int ntb_transport_register_client_dev(char *device_name)
361 {
362 struct ntb_transport_client_dev *client_dev;
363 struct ntb_transport_ctx *nt;
364 int node;
365 int rc, i = 0;
366
367 if (list_empty(&ntb_transport_list))
368 return -ENODEV;
369
370 list_for_each_entry(nt, &ntb_transport_list, entry) {
371 struct device *dev;
372
373 node = dev_to_node(&nt->ndev->dev);
374
375 client_dev = kzalloc_node(sizeof(*client_dev),
376 GFP_KERNEL, node);
377 if (!client_dev) {
378 rc = -ENOMEM;
379 goto err;
380 }
381
382 dev = &client_dev->dev;
383
384 /* setup and register client devices */
385 dev_set_name(dev, "%s%d", device_name, i);
386 dev->bus = &ntb_transport_bus;
387 dev->release = ntb_transport_client_release;
388 dev->parent = &nt->ndev->dev;
389
390 rc = device_register(dev);
391 if (rc) {
392 kfree(client_dev);
393 goto err;
394 }
395
396 list_add_tail(&client_dev->entry, &nt->client_devs);
397 i++;
398 }
399
400 return 0;
401
402 err:
403 ntb_transport_unregister_client_dev(device_name);
404
405 return rc;
406 }
407 EXPORT_SYMBOL_GPL(ntb_transport_register_client_dev);
408
409 /**
410 * ntb_transport_register_client - Register NTB client driver
411 * @drv: NTB client driver to be registered
412 *
413 * Register an NTB client driver with the NTB transport layer
414 *
415 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
416 */
417 int ntb_transport_register_client(struct ntb_transport_client *drv)
418 {
419 drv->driver.bus = &ntb_transport_bus;
420
421 if (list_empty(&ntb_transport_list))
422 return -ENODEV;
423
424 return driver_register(&drv->driver);
425 }
426 EXPORT_SYMBOL_GPL(ntb_transport_register_client);
427
428 /**
429 * ntb_transport_unregister_client - Unregister NTB client driver
430 * @drv: NTB client driver to be unregistered
431 *
432 * Unregister an NTB client driver with the NTB transport layer
433 *
434 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
435 */
436 void ntb_transport_unregister_client(struct ntb_transport_client *drv)
437 {
438 driver_unregister(&drv->driver);
439 }
440 EXPORT_SYMBOL_GPL(ntb_transport_unregister_client);
441
442 static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count,
443 loff_t *offp)
444 {
445 struct ntb_transport_qp *qp;
446 char *buf;
447 ssize_t ret, out_offset, out_count;
448
449 qp = filp->private_data;
450
451 if (!qp || !qp->link_is_up)
452 return 0;
453
454 out_count = 1000;
455
456 buf = kmalloc(out_count, GFP_KERNEL);
457 if (!buf)
458 return -ENOMEM;
459
460 out_offset = 0;
461 out_offset += snprintf(buf + out_offset, out_count - out_offset,
462 "\nNTB QP stats:\n\n");
463 out_offset += snprintf(buf + out_offset, out_count - out_offset,
464 "rx_bytes - \t%llu\n", qp->rx_bytes);
465 out_offset += snprintf(buf + out_offset, out_count - out_offset,
466 "rx_pkts - \t%llu\n", qp->rx_pkts);
467 out_offset += snprintf(buf + out_offset, out_count - out_offset,
468 "rx_memcpy - \t%llu\n", qp->rx_memcpy);
469 out_offset += snprintf(buf + out_offset, out_count - out_offset,
470 "rx_async - \t%llu\n", qp->rx_async);
471 out_offset += snprintf(buf + out_offset, out_count - out_offset,
472 "rx_ring_empty - %llu\n", qp->rx_ring_empty);
473 out_offset += snprintf(buf + out_offset, out_count - out_offset,
474 "rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
475 out_offset += snprintf(buf + out_offset, out_count - out_offset,
476 "rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
477 out_offset += snprintf(buf + out_offset, out_count - out_offset,
478 "rx_err_ver - \t%llu\n", qp->rx_err_ver);
479 out_offset += snprintf(buf + out_offset, out_count - out_offset,
480 "rx_buff - \t0x%p\n", qp->rx_buff);
481 out_offset += snprintf(buf + out_offset, out_count - out_offset,
482 "rx_index - \t%u\n", qp->rx_index);
483 out_offset += snprintf(buf + out_offset, out_count - out_offset,
484 "rx_max_entry - \t%u\n", qp->rx_max_entry);
485 out_offset += snprintf(buf + out_offset, out_count - out_offset,
486 "rx_alloc_entry - \t%u\n\n", qp->rx_alloc_entry);
487
488 out_offset += snprintf(buf + out_offset, out_count - out_offset,
489 "tx_bytes - \t%llu\n", qp->tx_bytes);
490 out_offset += snprintf(buf + out_offset, out_count - out_offset,
491 "tx_pkts - \t%llu\n", qp->tx_pkts);
492 out_offset += snprintf(buf + out_offset, out_count - out_offset,
493 "tx_memcpy - \t%llu\n", qp->tx_memcpy);
494 out_offset += snprintf(buf + out_offset, out_count - out_offset,
495 "tx_async - \t%llu\n", qp->tx_async);
496 out_offset += snprintf(buf + out_offset, out_count - out_offset,
497 "tx_ring_full - \t%llu\n", qp->tx_ring_full);
498 out_offset += snprintf(buf + out_offset, out_count - out_offset,
499 "tx_err_no_buf - %llu\n", qp->tx_err_no_buf);
500 out_offset += snprintf(buf + out_offset, out_count - out_offset,
501 "tx_mw - \t0x%p\n", qp->tx_mw);
502 out_offset += snprintf(buf + out_offset, out_count - out_offset,
503 "tx_index (H) - \t%u\n", qp->tx_index);
504 out_offset += snprintf(buf + out_offset, out_count - out_offset,
505 "RRI (T) - \t%u\n",
506 qp->remote_rx_info->entry);
507 out_offset += snprintf(buf + out_offset, out_count - out_offset,
508 "tx_max_entry - \t%u\n", qp->tx_max_entry);
509 out_offset += snprintf(buf + out_offset, out_count - out_offset,
510 "free tx - \t%u\n",
511 ntb_transport_tx_free_entry(qp));
512 out_offset += snprintf(buf + out_offset, out_count - out_offset,
513 "DMA tx prep err - \t%llu\n",
514 qp->dma_tx_prep_err);
515 out_offset += snprintf(buf + out_offset, out_count - out_offset,
516 "DMA rx prep err - \t%llu\n",
517 qp->dma_rx_prep_err);
518
519 out_offset += snprintf(buf + out_offset, out_count - out_offset,
520 "\n");
521 out_offset += snprintf(buf + out_offset, out_count - out_offset,
522 "Using TX DMA - \t%s\n",
523 qp->tx_dma_chan ? "Yes" : "No");
524 out_offset += snprintf(buf + out_offset, out_count - out_offset,
525 "Using RX DMA - \t%s\n",
526 qp->rx_dma_chan ? "Yes" : "No");
527 out_offset += snprintf(buf + out_offset, out_count - out_offset,
528 "QP Link - \t%s\n",
529 qp->link_is_up ? "Up" : "Down");
530 out_offset += snprintf(buf + out_offset, out_count - out_offset,
531 "\n");
532
533 if (out_offset > out_count)
534 out_offset = out_count;
535
536 ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
537 kfree(buf);
538 return ret;
539 }
540
541 static const struct file_operations ntb_qp_debugfs_stats = {
542 .owner = THIS_MODULE,
543 .open = simple_open,
544 .read = debugfs_read,
545 };
546
547 static void ntb_list_add(spinlock_t *lock, struct list_head *entry,
548 struct list_head *list)
549 {
550 unsigned long flags;
551
552 spin_lock_irqsave(lock, flags);
553 list_add_tail(entry, list);
554 spin_unlock_irqrestore(lock, flags);
555 }
556
557 static struct ntb_queue_entry *ntb_list_rm(spinlock_t *lock,
558 struct list_head *list)
559 {
560 struct ntb_queue_entry *entry;
561 unsigned long flags;
562
563 spin_lock_irqsave(lock, flags);
564 if (list_empty(list)) {
565 entry = NULL;
566 goto out;
567 }
568 entry = list_first_entry(list, struct ntb_queue_entry, entry);
569 list_del(&entry->entry);
570
571 out:
572 spin_unlock_irqrestore(lock, flags);
573
574 return entry;
575 }
576
577 static struct ntb_queue_entry *ntb_list_mv(spinlock_t *lock,
578 struct list_head *list,
579 struct list_head *to_list)
580 {
581 struct ntb_queue_entry *entry;
582 unsigned long flags;
583
584 spin_lock_irqsave(lock, flags);
585
586 if (list_empty(list)) {
587 entry = NULL;
588 } else {
589 entry = list_first_entry(list, struct ntb_queue_entry, entry);
590 list_move_tail(&entry->entry, to_list);
591 }
592
593 spin_unlock_irqrestore(lock, flags);
594
595 return entry;
596 }
597
598 static int ntb_transport_setup_qp_mw(struct ntb_transport_ctx *nt,
599 unsigned int qp_num)
600 {
601 struct ntb_transport_qp *qp = &nt->qp_vec[qp_num];
602 struct ntb_transport_mw *mw;
603 struct ntb_dev *ndev = nt->ndev;
604 struct ntb_queue_entry *entry;
605 unsigned int rx_size, num_qps_mw;
606 unsigned int mw_num, mw_count, qp_count;
607 unsigned int i;
608 int node;
609
610 mw_count = nt->mw_count;
611 qp_count = nt->qp_count;
612
613 mw_num = QP_TO_MW(nt, qp_num);
614 mw = &nt->mw_vec[mw_num];
615
616 if (!mw->virt_addr)
617 return -ENOMEM;
618
619 if (qp_count % mw_count && mw_num + 1 < qp_count / mw_count)
620 num_qps_mw = qp_count / mw_count + 1;
621 else
622 num_qps_mw = qp_count / mw_count;
623
624 rx_size = (unsigned int)mw->xlat_size / num_qps_mw;
625 qp->rx_buff = mw->virt_addr + rx_size * (qp_num / mw_count);
626 rx_size -= sizeof(struct ntb_rx_info);
627
628 qp->remote_rx_info = qp->rx_buff + rx_size;
629
630 /* Due to housekeeping, there must be atleast 2 buffs */
631 qp->rx_max_frame = min(transport_mtu, rx_size / 2);
632 qp->rx_max_entry = rx_size / qp->rx_max_frame;
633 qp->rx_index = 0;
634
635 /*
636 * Checking to see if we have more entries than the default.
637 * We should add additional entries if that is the case so we
638 * can be in sync with the transport frames.
639 */
640 node = dev_to_node(&ndev->dev);
641 for (i = qp->rx_alloc_entry; i < qp->rx_max_entry; i++) {
642 entry = kzalloc_node(sizeof(*entry), GFP_ATOMIC, node);
643 if (!entry)
644 return -ENOMEM;
645
646 entry->qp = qp;
647 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry,
648 &qp->rx_free_q);
649 qp->rx_alloc_entry++;
650 }
651
652 qp->remote_rx_info->entry = qp->rx_max_entry - 1;
653
654 /* setup the hdr offsets with 0's */
655 for (i = 0; i < qp->rx_max_entry; i++) {
656 void *offset = (qp->rx_buff + qp->rx_max_frame * (i + 1) -
657 sizeof(struct ntb_payload_header));
658 memset(offset, 0, sizeof(struct ntb_payload_header));
659 }
660
661 qp->rx_pkts = 0;
662 qp->tx_pkts = 0;
663 qp->tx_index = 0;
664
665 return 0;
666 }
667
668 static void ntb_free_mw(struct ntb_transport_ctx *nt, int num_mw)
669 {
670 struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
671 struct pci_dev *pdev = nt->ndev->pdev;
672
673 if (!mw->virt_addr)
674 return;
675
676 ntb_mw_clear_trans(nt->ndev, num_mw);
677 dma_free_coherent(&pdev->dev, mw->buff_size,
678 mw->virt_addr, mw->dma_addr);
679 mw->xlat_size = 0;
680 mw->buff_size = 0;
681 mw->virt_addr = NULL;
682 }
683
684 static int ntb_set_mw(struct ntb_transport_ctx *nt, int num_mw,
685 resource_size_t size)
686 {
687 struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
688 struct pci_dev *pdev = nt->ndev->pdev;
689 size_t xlat_size, buff_size;
690 int rc;
691
692 if (!size)
693 return -EINVAL;
694
695 xlat_size = round_up(size, mw->xlat_align_size);
696 buff_size = round_up(size, mw->xlat_align);
697
698 /* No need to re-setup */
699 if (mw->xlat_size == xlat_size)
700 return 0;
701
702 if (mw->buff_size)
703 ntb_free_mw(nt, num_mw);
704
705 /* Alloc memory for receiving data. Must be aligned */
706 mw->xlat_size = xlat_size;
707 mw->buff_size = buff_size;
708
709 mw->virt_addr = dma_alloc_coherent(&pdev->dev, buff_size,
710 &mw->dma_addr, GFP_KERNEL);
711 if (!mw->virt_addr) {
712 mw->xlat_size = 0;
713 mw->buff_size = 0;
714 dev_err(&pdev->dev, "Unable to alloc MW buff of size %zu\n",
715 buff_size);
716 return -ENOMEM;
717 }
718
719 /*
720 * we must ensure that the memory address allocated is BAR size
721 * aligned in order for the XLAT register to take the value. This
722 * is a requirement of the hardware. It is recommended to setup CMA
723 * for BAR sizes equal or greater than 4MB.
724 */
725 if (!IS_ALIGNED(mw->dma_addr, mw->xlat_align)) {
726 dev_err(&pdev->dev, "DMA memory %pad is not aligned\n",
727 &mw->dma_addr);
728 ntb_free_mw(nt, num_mw);
729 return -ENOMEM;
730 }
731
732 /* Notify HW the memory location of the receive buffer */
733 rc = ntb_mw_set_trans(nt->ndev, num_mw, mw->dma_addr, mw->xlat_size);
734 if (rc) {
735 dev_err(&pdev->dev, "Unable to set mw%d translation", num_mw);
736 ntb_free_mw(nt, num_mw);
737 return -EIO;
738 }
739
740 return 0;
741 }
742
743 static void ntb_qp_link_down_reset(struct ntb_transport_qp *qp)
744 {
745 qp->link_is_up = false;
746 qp->active = false;
747
748 qp->tx_index = 0;
749 qp->rx_index = 0;
750 qp->rx_bytes = 0;
751 qp->rx_pkts = 0;
752 qp->rx_ring_empty = 0;
753 qp->rx_err_no_buf = 0;
754 qp->rx_err_oflow = 0;
755 qp->rx_err_ver = 0;
756 qp->rx_memcpy = 0;
757 qp->rx_async = 0;
758 qp->tx_bytes = 0;
759 qp->tx_pkts = 0;
760 qp->tx_ring_full = 0;
761 qp->tx_err_no_buf = 0;
762 qp->tx_memcpy = 0;
763 qp->tx_async = 0;
764 qp->dma_tx_prep_err = 0;
765 qp->dma_rx_prep_err = 0;
766 }
767
768 static void ntb_qp_link_cleanup(struct ntb_transport_qp *qp)
769 {
770 struct ntb_transport_ctx *nt = qp->transport;
771 struct pci_dev *pdev = nt->ndev->pdev;
772
773 dev_info(&pdev->dev, "qp %d: Link Cleanup\n", qp->qp_num);
774
775 cancel_delayed_work_sync(&qp->link_work);
776 ntb_qp_link_down_reset(qp);
777
778 if (qp->event_handler)
779 qp->event_handler(qp->cb_data, qp->link_is_up);
780 }
781
782 static void ntb_qp_link_cleanup_work(struct work_struct *work)
783 {
784 struct ntb_transport_qp *qp = container_of(work,
785 struct ntb_transport_qp,
786 link_cleanup);
787 struct ntb_transport_ctx *nt = qp->transport;
788
789 ntb_qp_link_cleanup(qp);
790
791 if (nt->link_is_up)
792 schedule_delayed_work(&qp->link_work,
793 msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
794 }
795
796 static void ntb_qp_link_down(struct ntb_transport_qp *qp)
797 {
798 schedule_work(&qp->link_cleanup);
799 }
800
801 static void ntb_transport_link_cleanup(struct ntb_transport_ctx *nt)
802 {
803 struct ntb_transport_qp *qp;
804 u64 qp_bitmap_alloc;
805 int i;
806
807 qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
808
809 /* Pass along the info to any clients */
810 for (i = 0; i < nt->qp_count; i++)
811 if (qp_bitmap_alloc & BIT_ULL(i)) {
812 qp = &nt->qp_vec[i];
813 ntb_qp_link_cleanup(qp);
814 cancel_work_sync(&qp->link_cleanup);
815 cancel_delayed_work_sync(&qp->link_work);
816 }
817
818 if (!nt->link_is_up)
819 cancel_delayed_work_sync(&nt->link_work);
820
821 /* The scratchpad registers keep the values if the remote side
822 * goes down, blast them now to give them a sane value the next
823 * time they are accessed
824 */
825 for (i = 0; i < MAX_SPAD; i++)
826 ntb_spad_write(nt->ndev, i, 0);
827 }
828
829 static void ntb_transport_link_cleanup_work(struct work_struct *work)
830 {
831 struct ntb_transport_ctx *nt =
832 container_of(work, struct ntb_transport_ctx, link_cleanup);
833
834 ntb_transport_link_cleanup(nt);
835 }
836
837 static void ntb_transport_event_callback(void *data)
838 {
839 struct ntb_transport_ctx *nt = data;
840
841 if (ntb_link_is_up(nt->ndev, NULL, NULL) == 1)
842 schedule_delayed_work(&nt->link_work, 0);
843 else
844 schedule_work(&nt->link_cleanup);
845 }
846
847 static void ntb_transport_link_work(struct work_struct *work)
848 {
849 struct ntb_transport_ctx *nt =
850 container_of(work, struct ntb_transport_ctx, link_work.work);
851 struct ntb_dev *ndev = nt->ndev;
852 struct pci_dev *pdev = ndev->pdev;
853 resource_size_t size;
854 u32 val;
855 int rc = 0, i, spad;
856
857 /* send the local info, in the opposite order of the way we read it */
858 for (i = 0; i < nt->mw_count; i++) {
859 size = nt->mw_vec[i].phys_size;
860
861 if (max_mw_size && size > max_mw_size)
862 size = max_mw_size;
863
864 spad = MW0_SZ_HIGH + (i * 2);
865 ntb_peer_spad_write(ndev, spad, upper_32_bits(size));
866
867 spad = MW0_SZ_LOW + (i * 2);
868 ntb_peer_spad_write(ndev, spad, lower_32_bits(size));
869 }
870
871 ntb_peer_spad_write(ndev, NUM_MWS, nt->mw_count);
872
873 ntb_peer_spad_write(ndev, NUM_QPS, nt->qp_count);
874
875 ntb_peer_spad_write(ndev, VERSION, NTB_TRANSPORT_VERSION);
876
877 /* Query the remote side for its info */
878 val = ntb_spad_read(ndev, VERSION);
879 dev_dbg(&pdev->dev, "Remote version = %d\n", val);
880 if (val != NTB_TRANSPORT_VERSION)
881 goto out;
882
883 val = ntb_spad_read(ndev, NUM_QPS);
884 dev_dbg(&pdev->dev, "Remote max number of qps = %d\n", val);
885 if (val != nt->qp_count)
886 goto out;
887
888 val = ntb_spad_read(ndev, NUM_MWS);
889 dev_dbg(&pdev->dev, "Remote number of mws = %d\n", val);
890 if (val != nt->mw_count)
891 goto out;
892
893 for (i = 0; i < nt->mw_count; i++) {
894 u64 val64;
895
896 val = ntb_spad_read(ndev, MW0_SZ_HIGH + (i * 2));
897 val64 = (u64)val << 32;
898
899 val = ntb_spad_read(ndev, MW0_SZ_LOW + (i * 2));
900 val64 |= val;
901
902 dev_dbg(&pdev->dev, "Remote MW%d size = %#llx\n", i, val64);
903
904 rc = ntb_set_mw(nt, i, val64);
905 if (rc)
906 goto out1;
907 }
908
909 nt->link_is_up = true;
910
911 for (i = 0; i < nt->qp_count; i++) {
912 struct ntb_transport_qp *qp = &nt->qp_vec[i];
913
914 ntb_transport_setup_qp_mw(nt, i);
915
916 if (qp->client_ready)
917 schedule_delayed_work(&qp->link_work, 0);
918 }
919
920 return;
921
922 out1:
923 for (i = 0; i < nt->mw_count; i++)
924 ntb_free_mw(nt, i);
925
926 /* if there's an actual failure, we should just bail */
927 if (rc < 0) {
928 ntb_link_disable(ndev);
929 return;
930 }
931
932 out:
933 if (ntb_link_is_up(ndev, NULL, NULL) == 1)
934 schedule_delayed_work(&nt->link_work,
935 msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
936 }
937
938 static void ntb_qp_link_work(struct work_struct *work)
939 {
940 struct ntb_transport_qp *qp = container_of(work,
941 struct ntb_transport_qp,
942 link_work.work);
943 struct pci_dev *pdev = qp->ndev->pdev;
944 struct ntb_transport_ctx *nt = qp->transport;
945 int val;
946
947 WARN_ON(!nt->link_is_up);
948
949 val = ntb_spad_read(nt->ndev, QP_LINKS);
950
951 ntb_peer_spad_write(nt->ndev, QP_LINKS, val | BIT(qp->qp_num));
952
953 /* query remote spad for qp ready bits */
954 ntb_peer_spad_read(nt->ndev, QP_LINKS);
955 dev_dbg_ratelimited(&pdev->dev, "Remote QP link status = %x\n", val);
956
957 /* See if the remote side is up */
958 if (val & BIT(qp->qp_num)) {
959 dev_info(&pdev->dev, "qp %d: Link Up\n", qp->qp_num);
960 qp->link_is_up = true;
961 qp->active = true;
962
963 if (qp->event_handler)
964 qp->event_handler(qp->cb_data, qp->link_is_up);
965
966 if (qp->active)
967 tasklet_schedule(&qp->rxc_db_work);
968 } else if (nt->link_is_up)
969 schedule_delayed_work(&qp->link_work,
970 msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
971 }
972
973 static int ntb_transport_init_queue(struct ntb_transport_ctx *nt,
974 unsigned int qp_num)
975 {
976 struct ntb_transport_qp *qp;
977 phys_addr_t mw_base;
978 resource_size_t mw_size;
979 unsigned int num_qps_mw, tx_size;
980 unsigned int mw_num, mw_count, qp_count;
981 u64 qp_offset;
982
983 mw_count = nt->mw_count;
984 qp_count = nt->qp_count;
985
986 mw_num = QP_TO_MW(nt, qp_num);
987
988 qp = &nt->qp_vec[qp_num];
989 qp->qp_num = qp_num;
990 qp->transport = nt;
991 qp->ndev = nt->ndev;
992 qp->client_ready = false;
993 qp->event_handler = NULL;
994 ntb_qp_link_down_reset(qp);
995
996 if (qp_count % mw_count && mw_num + 1 < qp_count / mw_count)
997 num_qps_mw = qp_count / mw_count + 1;
998 else
999 num_qps_mw = qp_count / mw_count;
1000
1001 mw_base = nt->mw_vec[mw_num].phys_addr;
1002 mw_size = nt->mw_vec[mw_num].phys_size;
1003
1004 tx_size = (unsigned int)mw_size / num_qps_mw;
1005 qp_offset = tx_size * (qp_num / mw_count);
1006
1007 qp->tx_mw = nt->mw_vec[mw_num].vbase + qp_offset;
1008 if (!qp->tx_mw)
1009 return -EINVAL;
1010
1011 qp->tx_mw_phys = mw_base + qp_offset;
1012 if (!qp->tx_mw_phys)
1013 return -EINVAL;
1014
1015 tx_size -= sizeof(struct ntb_rx_info);
1016 qp->rx_info = qp->tx_mw + tx_size;
1017
1018 /* Due to housekeeping, there must be atleast 2 buffs */
1019 qp->tx_max_frame = min(transport_mtu, tx_size / 2);
1020 qp->tx_max_entry = tx_size / qp->tx_max_frame;
1021
1022 if (nt->debugfs_node_dir) {
1023 char debugfs_name[4];
1024
1025 snprintf(debugfs_name, 4, "qp%d", qp_num);
1026 qp->debugfs_dir = debugfs_create_dir(debugfs_name,
1027 nt->debugfs_node_dir);
1028
1029 qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR,
1030 qp->debugfs_dir, qp,
1031 &ntb_qp_debugfs_stats);
1032 } else {
1033 qp->debugfs_dir = NULL;
1034 qp->debugfs_stats = NULL;
1035 }
1036
1037 INIT_DELAYED_WORK(&qp->link_work, ntb_qp_link_work);
1038 INIT_WORK(&qp->link_cleanup, ntb_qp_link_cleanup_work);
1039
1040 spin_lock_init(&qp->ntb_rx_q_lock);
1041 spin_lock_init(&qp->ntb_tx_free_q_lock);
1042
1043 INIT_LIST_HEAD(&qp->rx_post_q);
1044 INIT_LIST_HEAD(&qp->rx_pend_q);
1045 INIT_LIST_HEAD(&qp->rx_free_q);
1046 INIT_LIST_HEAD(&qp->tx_free_q);
1047
1048 tasklet_init(&qp->rxc_db_work, ntb_transport_rxc_db,
1049 (unsigned long)qp);
1050
1051 return 0;
1052 }
1053
1054 static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev)
1055 {
1056 struct ntb_transport_ctx *nt;
1057 struct ntb_transport_mw *mw;
1058 unsigned int mw_count, qp_count;
1059 u64 qp_bitmap;
1060 int node;
1061 int rc, i;
1062
1063 mw_count = ntb_mw_count(ndev);
1064 if (ntb_spad_count(ndev) < (NUM_MWS + 1 + mw_count * 2)) {
1065 dev_err(&ndev->dev, "Not enough scratch pad registers for %s",
1066 NTB_TRANSPORT_NAME);
1067 return -EIO;
1068 }
1069
1070 if (ntb_db_is_unsafe(ndev))
1071 dev_dbg(&ndev->dev,
1072 "doorbell is unsafe, proceed anyway...\n");
1073 if (ntb_spad_is_unsafe(ndev))
1074 dev_dbg(&ndev->dev,
1075 "scratchpad is unsafe, proceed anyway...\n");
1076
1077 node = dev_to_node(&ndev->dev);
1078
1079 nt = kzalloc_node(sizeof(*nt), GFP_KERNEL, node);
1080 if (!nt)
1081 return -ENOMEM;
1082
1083 nt->ndev = ndev;
1084
1085 nt->mw_count = mw_count;
1086
1087 nt->mw_vec = kzalloc_node(mw_count * sizeof(*nt->mw_vec),
1088 GFP_KERNEL, node);
1089 if (!nt->mw_vec) {
1090 rc = -ENOMEM;
1091 goto err;
1092 }
1093
1094 for (i = 0; i < mw_count; i++) {
1095 mw = &nt->mw_vec[i];
1096
1097 rc = ntb_mw_get_range(ndev, i, &mw->phys_addr, &mw->phys_size,
1098 &mw->xlat_align, &mw->xlat_align_size);
1099 if (rc)
1100 goto err1;
1101
1102 mw->vbase = ioremap_wc(mw->phys_addr, mw->phys_size);
1103 if (!mw->vbase) {
1104 rc = -ENOMEM;
1105 goto err1;
1106 }
1107
1108 mw->buff_size = 0;
1109 mw->xlat_size = 0;
1110 mw->virt_addr = NULL;
1111 mw->dma_addr = 0;
1112 }
1113
1114 qp_bitmap = ntb_db_valid_mask(ndev);
1115
1116 qp_count = ilog2(qp_bitmap);
1117 if (max_num_clients && max_num_clients < qp_count)
1118 qp_count = max_num_clients;
1119 else if (mw_count < qp_count)
1120 qp_count = mw_count;
1121
1122 qp_bitmap &= BIT_ULL(qp_count) - 1;
1123
1124 nt->qp_count = qp_count;
1125 nt->qp_bitmap = qp_bitmap;
1126 nt->qp_bitmap_free = qp_bitmap;
1127
1128 nt->qp_vec = kzalloc_node(qp_count * sizeof(*nt->qp_vec),
1129 GFP_KERNEL, node);
1130 if (!nt->qp_vec) {
1131 rc = -ENOMEM;
1132 goto err1;
1133 }
1134
1135 if (nt_debugfs_dir) {
1136 nt->debugfs_node_dir =
1137 debugfs_create_dir(pci_name(ndev->pdev),
1138 nt_debugfs_dir);
1139 }
1140
1141 for (i = 0; i < qp_count; i++) {
1142 rc = ntb_transport_init_queue(nt, i);
1143 if (rc)
1144 goto err2;
1145 }
1146
1147 INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work);
1148 INIT_WORK(&nt->link_cleanup, ntb_transport_link_cleanup_work);
1149
1150 rc = ntb_set_ctx(ndev, nt, &ntb_transport_ops);
1151 if (rc)
1152 goto err2;
1153
1154 INIT_LIST_HEAD(&nt->client_devs);
1155 rc = ntb_bus_init(nt);
1156 if (rc)
1157 goto err3;
1158
1159 nt->link_is_up = false;
1160 ntb_link_enable(ndev, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
1161 ntb_link_event(ndev);
1162
1163 return 0;
1164
1165 err3:
1166 ntb_clear_ctx(ndev);
1167 err2:
1168 kfree(nt->qp_vec);
1169 err1:
1170 while (i--) {
1171 mw = &nt->mw_vec[i];
1172 iounmap(mw->vbase);
1173 }
1174 kfree(nt->mw_vec);
1175 err:
1176 kfree(nt);
1177 return rc;
1178 }
1179
1180 static void ntb_transport_free(struct ntb_client *self, struct ntb_dev *ndev)
1181 {
1182 struct ntb_transport_ctx *nt = ndev->ctx;
1183 struct ntb_transport_qp *qp;
1184 u64 qp_bitmap_alloc;
1185 int i;
1186
1187 ntb_transport_link_cleanup(nt);
1188 cancel_work_sync(&nt->link_cleanup);
1189 cancel_delayed_work_sync(&nt->link_work);
1190
1191 qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
1192
1193 /* verify that all the qp's are freed */
1194 for (i = 0; i < nt->qp_count; i++) {
1195 qp = &nt->qp_vec[i];
1196 if (qp_bitmap_alloc & BIT_ULL(i))
1197 ntb_transport_free_queue(qp);
1198 debugfs_remove_recursive(qp->debugfs_dir);
1199 }
1200
1201 ntb_link_disable(ndev);
1202 ntb_clear_ctx(ndev);
1203
1204 ntb_bus_remove(nt);
1205
1206 for (i = nt->mw_count; i--; ) {
1207 ntb_free_mw(nt, i);
1208 iounmap(nt->mw_vec[i].vbase);
1209 }
1210
1211 kfree(nt->qp_vec);
1212 kfree(nt->mw_vec);
1213 kfree(nt);
1214 }
1215
1216 static void ntb_complete_rxc(struct ntb_transport_qp *qp)
1217 {
1218 struct ntb_queue_entry *entry;
1219 void *cb_data;
1220 unsigned int len;
1221 unsigned long irqflags;
1222
1223 spin_lock_irqsave(&qp->ntb_rx_q_lock, irqflags);
1224
1225 while (!list_empty(&qp->rx_post_q)) {
1226 entry = list_first_entry(&qp->rx_post_q,
1227 struct ntb_queue_entry, entry);
1228 if (!(entry->flags & DESC_DONE_FLAG))
1229 break;
1230
1231 entry->rx_hdr->flags = 0;
1232 iowrite32(entry->index, &qp->rx_info->entry);
1233
1234 cb_data = entry->cb_data;
1235 len = entry->len;
1236
1237 list_move_tail(&entry->entry, &qp->rx_free_q);
1238
1239 spin_unlock_irqrestore(&qp->ntb_rx_q_lock, irqflags);
1240
1241 if (qp->rx_handler && qp->client_ready)
1242 qp->rx_handler(qp, qp->cb_data, cb_data, len);
1243
1244 spin_lock_irqsave(&qp->ntb_rx_q_lock, irqflags);
1245 }
1246
1247 spin_unlock_irqrestore(&qp->ntb_rx_q_lock, irqflags);
1248 }
1249
1250 static void ntb_rx_copy_callback(void *data)
1251 {
1252 struct ntb_queue_entry *entry = data;
1253
1254 entry->flags |= DESC_DONE_FLAG;
1255
1256 ntb_complete_rxc(entry->qp);
1257 }
1258
1259 static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void *offset)
1260 {
1261 void *buf = entry->buf;
1262 size_t len = entry->len;
1263
1264 memcpy(buf, offset, len);
1265
1266 /* Ensure that the data is fully copied out before clearing the flag */
1267 wmb();
1268
1269 ntb_rx_copy_callback(entry);
1270 }
1271
1272 static void ntb_async_rx(struct ntb_queue_entry *entry, void *offset)
1273 {
1274 struct dma_async_tx_descriptor *txd;
1275 struct ntb_transport_qp *qp = entry->qp;
1276 struct dma_chan *chan = qp->rx_dma_chan;
1277 struct dma_device *device;
1278 size_t pay_off, buff_off, len;
1279 struct dmaengine_unmap_data *unmap;
1280 dma_cookie_t cookie;
1281 void *buf = entry->buf;
1282 int retries = 0;
1283
1284 len = entry->len;
1285
1286 if (!chan)
1287 goto err;
1288
1289 if (len < copy_bytes)
1290 goto err;
1291
1292 device = chan->device;
1293 pay_off = (size_t)offset & ~PAGE_MASK;
1294 buff_off = (size_t)buf & ~PAGE_MASK;
1295
1296 if (!is_dma_copy_aligned(device, pay_off, buff_off, len))
1297 goto err;
1298
1299 unmap = dmaengine_get_unmap_data(device->dev, 2, GFP_NOWAIT);
1300 if (!unmap)
1301 goto err;
1302
1303 unmap->len = len;
1304 unmap->addr[0] = dma_map_page(device->dev, virt_to_page(offset),
1305 pay_off, len, DMA_TO_DEVICE);
1306 if (dma_mapping_error(device->dev, unmap->addr[0]))
1307 goto err_get_unmap;
1308
1309 unmap->to_cnt = 1;
1310
1311 unmap->addr[1] = dma_map_page(device->dev, virt_to_page(buf),
1312 buff_off, len, DMA_FROM_DEVICE);
1313 if (dma_mapping_error(device->dev, unmap->addr[1]))
1314 goto err_get_unmap;
1315
1316 unmap->from_cnt = 1;
1317
1318 for (retries = 0; retries < DMA_RETRIES; retries++) {
1319 txd = device->device_prep_dma_memcpy(chan, unmap->addr[1],
1320 unmap->addr[0], len,
1321 DMA_PREP_INTERRUPT);
1322 if (txd)
1323 break;
1324
1325 set_current_state(TASK_INTERRUPTIBLE);
1326 schedule_timeout(DMA_OUT_RESOURCE_TO);
1327 }
1328
1329 if (!txd) {
1330 qp->dma_rx_prep_err++;
1331 goto err_get_unmap;
1332 }
1333
1334 txd->callback = ntb_rx_copy_callback;
1335 txd->callback_param = entry;
1336 dma_set_unmap(txd, unmap);
1337
1338 cookie = dmaengine_submit(txd);
1339 if (dma_submit_error(cookie))
1340 goto err_set_unmap;
1341
1342 dmaengine_unmap_put(unmap);
1343
1344 qp->last_cookie = cookie;
1345
1346 qp->rx_async++;
1347
1348 return;
1349
1350 err_set_unmap:
1351 dmaengine_unmap_put(unmap);
1352 err_get_unmap:
1353 dmaengine_unmap_put(unmap);
1354 err:
1355 ntb_memcpy_rx(entry, offset);
1356 qp->rx_memcpy++;
1357 }
1358
1359 static int ntb_process_rxc(struct ntb_transport_qp *qp)
1360 {
1361 struct ntb_payload_header *hdr;
1362 struct ntb_queue_entry *entry;
1363 void *offset;
1364
1365 offset = qp->rx_buff + qp->rx_max_frame * qp->rx_index;
1366 hdr = offset + qp->rx_max_frame - sizeof(struct ntb_payload_header);
1367
1368 dev_dbg(&qp->ndev->pdev->dev, "qp %d: RX ver %u len %d flags %x\n",
1369 qp->qp_num, hdr->ver, hdr->len, hdr->flags);
1370
1371 if (!(hdr->flags & DESC_DONE_FLAG)) {
1372 dev_dbg(&qp->ndev->pdev->dev, "done flag not set\n");
1373 qp->rx_ring_empty++;
1374 return -EAGAIN;
1375 }
1376
1377 if (hdr->flags & LINK_DOWN_FLAG) {
1378 dev_dbg(&qp->ndev->pdev->dev, "link down flag set\n");
1379 ntb_qp_link_down(qp);
1380 hdr->flags = 0;
1381 return -EAGAIN;
1382 }
1383
1384 if (hdr->ver != (u32)qp->rx_pkts) {
1385 dev_dbg(&qp->ndev->pdev->dev,
1386 "version mismatch, expected %llu - got %u\n",
1387 qp->rx_pkts, hdr->ver);
1388 qp->rx_err_ver++;
1389 return -EIO;
1390 }
1391
1392 entry = ntb_list_mv(&qp->ntb_rx_q_lock, &qp->rx_pend_q, &qp->rx_post_q);
1393 if (!entry) {
1394 dev_dbg(&qp->ndev->pdev->dev, "no receive buffer\n");
1395 qp->rx_err_no_buf++;
1396 return -EAGAIN;
1397 }
1398
1399 entry->rx_hdr = hdr;
1400 entry->index = qp->rx_index;
1401
1402 if (hdr->len > entry->len) {
1403 dev_dbg(&qp->ndev->pdev->dev,
1404 "receive buffer overflow! Wanted %d got %d\n",
1405 hdr->len, entry->len);
1406 qp->rx_err_oflow++;
1407
1408 entry->len = -EIO;
1409 entry->flags |= DESC_DONE_FLAG;
1410
1411 ntb_complete_rxc(qp);
1412 } else {
1413 dev_dbg(&qp->ndev->pdev->dev,
1414 "RX OK index %u ver %u size %d into buf size %d\n",
1415 qp->rx_index, hdr->ver, hdr->len, entry->len);
1416
1417 qp->rx_bytes += hdr->len;
1418 qp->rx_pkts++;
1419
1420 entry->len = hdr->len;
1421
1422 ntb_async_rx(entry, offset);
1423 }
1424
1425 qp->rx_index++;
1426 qp->rx_index %= qp->rx_max_entry;
1427
1428 return 0;
1429 }
1430
1431 static void ntb_transport_rxc_db(unsigned long data)
1432 {
1433 struct ntb_transport_qp *qp = (void *)data;
1434 int rc, i;
1435
1436 dev_dbg(&qp->ndev->pdev->dev, "%s: doorbell %d received\n",
1437 __func__, qp->qp_num);
1438
1439 /* Limit the number of packets processed in a single interrupt to
1440 * provide fairness to others
1441 */
1442 for (i = 0; i < qp->rx_max_entry; i++) {
1443 rc = ntb_process_rxc(qp);
1444 if (rc)
1445 break;
1446 }
1447
1448 if (i && qp->rx_dma_chan)
1449 dma_async_issue_pending(qp->rx_dma_chan);
1450
1451 if (i == qp->rx_max_entry) {
1452 /* there is more work to do */
1453 if (qp->active)
1454 tasklet_schedule(&qp->rxc_db_work);
1455 } else if (ntb_db_read(qp->ndev) & BIT_ULL(qp->qp_num)) {
1456 /* the doorbell bit is set: clear it */
1457 ntb_db_clear(qp->ndev, BIT_ULL(qp->qp_num));
1458 /* ntb_db_read ensures ntb_db_clear write is committed */
1459 ntb_db_read(qp->ndev);
1460
1461 /* an interrupt may have arrived between finishing
1462 * ntb_process_rxc and clearing the doorbell bit:
1463 * there might be some more work to do.
1464 */
1465 if (qp->active)
1466 tasklet_schedule(&qp->rxc_db_work);
1467 }
1468 }
1469
1470 static void ntb_tx_copy_callback(void *data)
1471 {
1472 struct ntb_queue_entry *entry = data;
1473 struct ntb_transport_qp *qp = entry->qp;
1474 struct ntb_payload_header __iomem *hdr = entry->tx_hdr;
1475
1476 iowrite32(entry->flags | DESC_DONE_FLAG, &hdr->flags);
1477
1478 ntb_peer_db_set(qp->ndev, BIT_ULL(qp->qp_num));
1479
1480 /* The entry length can only be zero if the packet is intended to be a
1481 * "link down" or similar. Since no payload is being sent in these
1482 * cases, there is nothing to add to the completion queue.
1483 */
1484 if (entry->len > 0) {
1485 qp->tx_bytes += entry->len;
1486
1487 if (qp->tx_handler)
1488 qp->tx_handler(qp, qp->cb_data, entry->cb_data,
1489 entry->len);
1490 }
1491
1492 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q);
1493 }
1494
1495 static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset)
1496 {
1497 #ifdef ARCH_HAS_NOCACHE_UACCESS
1498 /*
1499 * Using non-temporal mov to improve performance on non-cached
1500 * writes, even though we aren't actually copying from user space.
1501 */
1502 __copy_from_user_inatomic_nocache(offset, entry->buf, entry->len);
1503 #else
1504 memcpy_toio(offset, entry->buf, entry->len);
1505 #endif
1506
1507 /* Ensure that the data is fully copied out before setting the flags */
1508 wmb();
1509
1510 ntb_tx_copy_callback(entry);
1511 }
1512
1513 static void ntb_async_tx(struct ntb_transport_qp *qp,
1514 struct ntb_queue_entry *entry)
1515 {
1516 struct ntb_payload_header __iomem *hdr;
1517 struct dma_async_tx_descriptor *txd;
1518 struct dma_chan *chan = qp->tx_dma_chan;
1519 struct dma_device *device;
1520 size_t dest_off, buff_off;
1521 struct dmaengine_unmap_data *unmap;
1522 dma_addr_t dest;
1523 dma_cookie_t cookie;
1524 void __iomem *offset;
1525 size_t len = entry->len;
1526 void *buf = entry->buf;
1527 int retries = 0;
1528
1529 offset = qp->tx_mw + qp->tx_max_frame * qp->tx_index;
1530 hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
1531 entry->tx_hdr = hdr;
1532
1533 iowrite32(entry->len, &hdr->len);
1534 iowrite32((u32)qp->tx_pkts, &hdr->ver);
1535
1536 if (!chan)
1537 goto err;
1538
1539 if (len < copy_bytes)
1540 goto err;
1541
1542 device = chan->device;
1543 dest = qp->tx_mw_phys + qp->tx_max_frame * qp->tx_index;
1544 buff_off = (size_t)buf & ~PAGE_MASK;
1545 dest_off = (size_t)dest & ~PAGE_MASK;
1546
1547 if (!is_dma_copy_aligned(device, buff_off, dest_off, len))
1548 goto err;
1549
1550 unmap = dmaengine_get_unmap_data(device->dev, 1, GFP_NOWAIT);
1551 if (!unmap)
1552 goto err;
1553
1554 unmap->len = len;
1555 unmap->addr[0] = dma_map_page(device->dev, virt_to_page(buf),
1556 buff_off, len, DMA_TO_DEVICE);
1557 if (dma_mapping_error(device->dev, unmap->addr[0]))
1558 goto err_get_unmap;
1559
1560 unmap->to_cnt = 1;
1561
1562 for (retries = 0; retries < DMA_RETRIES; retries++) {
1563 txd = device->device_prep_dma_memcpy(chan, dest, unmap->addr[0],
1564 len, DMA_PREP_INTERRUPT);
1565 if (txd)
1566 break;
1567
1568 set_current_state(TASK_INTERRUPTIBLE);
1569 schedule_timeout(DMA_OUT_RESOURCE_TO);
1570 }
1571
1572 if (!txd) {
1573 qp->dma_tx_prep_err++;
1574 goto err_get_unmap;
1575 }
1576
1577 txd->callback = ntb_tx_copy_callback;
1578 txd->callback_param = entry;
1579 dma_set_unmap(txd, unmap);
1580
1581 cookie = dmaengine_submit(txd);
1582 if (dma_submit_error(cookie))
1583 goto err_set_unmap;
1584
1585 dmaengine_unmap_put(unmap);
1586
1587 dma_async_issue_pending(chan);
1588 qp->tx_async++;
1589
1590 return;
1591 err_set_unmap:
1592 dmaengine_unmap_put(unmap);
1593 err_get_unmap:
1594 dmaengine_unmap_put(unmap);
1595 err:
1596 ntb_memcpy_tx(entry, offset);
1597 qp->tx_memcpy++;
1598 }
1599
1600 static int ntb_process_tx(struct ntb_transport_qp *qp,
1601 struct ntb_queue_entry *entry)
1602 {
1603 if (qp->tx_index == qp->remote_rx_info->entry) {
1604 qp->tx_ring_full++;
1605 return -EAGAIN;
1606 }
1607
1608 if (entry->len > qp->tx_max_frame - sizeof(struct ntb_payload_header)) {
1609 if (qp->tx_handler)
1610 qp->tx_handler(qp, qp->cb_data, NULL, -EIO);
1611
1612 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1613 &qp->tx_free_q);
1614 return 0;
1615 }
1616
1617 ntb_async_tx(qp, entry);
1618
1619 qp->tx_index++;
1620 qp->tx_index %= qp->tx_max_entry;
1621
1622 qp->tx_pkts++;
1623
1624 return 0;
1625 }
1626
1627 static void ntb_send_link_down(struct ntb_transport_qp *qp)
1628 {
1629 struct pci_dev *pdev = qp->ndev->pdev;
1630 struct ntb_queue_entry *entry;
1631 int i, rc;
1632
1633 if (!qp->link_is_up)
1634 return;
1635
1636 dev_info(&pdev->dev, "qp %d: Send Link Down\n", qp->qp_num);
1637
1638 for (i = 0; i < NTB_LINK_DOWN_TIMEOUT; i++) {
1639 entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1640 if (entry)
1641 break;
1642 msleep(100);
1643 }
1644
1645 if (!entry)
1646 return;
1647
1648 entry->cb_data = NULL;
1649 entry->buf = NULL;
1650 entry->len = 0;
1651 entry->flags = LINK_DOWN_FLAG;
1652
1653 rc = ntb_process_tx(qp, entry);
1654 if (rc)
1655 dev_err(&pdev->dev, "ntb: QP%d unable to send linkdown msg\n",
1656 qp->qp_num);
1657
1658 ntb_qp_link_down_reset(qp);
1659 }
1660
1661 static bool ntb_dma_filter_fn(struct dma_chan *chan, void *node)
1662 {
1663 return dev_to_node(&chan->dev->device) == (int)(unsigned long)node;
1664 }
1665
1666 /**
1667 * ntb_transport_create_queue - Create a new NTB transport layer queue
1668 * @rx_handler: receive callback function
1669 * @tx_handler: transmit callback function
1670 * @event_handler: event callback function
1671 *
1672 * Create a new NTB transport layer queue and provide the queue with a callback
1673 * routine for both transmit and receive. The receive callback routine will be
1674 * used to pass up data when the transport has received it on the queue. The
1675 * transmit callback routine will be called when the transport has completed the
1676 * transmission of the data on the queue and the data is ready to be freed.
1677 *
1678 * RETURNS: pointer to newly created ntb_queue, NULL on error.
1679 */
1680 struct ntb_transport_qp *
1681 ntb_transport_create_queue(void *data, struct device *client_dev,
1682 const struct ntb_queue_handlers *handlers)
1683 {
1684 struct ntb_dev *ndev;
1685 struct pci_dev *pdev;
1686 struct ntb_transport_ctx *nt;
1687 struct ntb_queue_entry *entry;
1688 struct ntb_transport_qp *qp;
1689 u64 qp_bit;
1690 unsigned int free_queue;
1691 dma_cap_mask_t dma_mask;
1692 int node;
1693 int i;
1694
1695 ndev = dev_ntb(client_dev->parent);
1696 pdev = ndev->pdev;
1697 nt = ndev->ctx;
1698
1699 node = dev_to_node(&ndev->dev);
1700
1701 free_queue = ffs(nt->qp_bitmap);
1702 if (!free_queue)
1703 goto err;
1704
1705 /* decrement free_queue to make it zero based */
1706 free_queue--;
1707
1708 qp = &nt->qp_vec[free_queue];
1709 qp_bit = BIT_ULL(qp->qp_num);
1710
1711 nt->qp_bitmap_free &= ~qp_bit;
1712
1713 qp->cb_data = data;
1714 qp->rx_handler = handlers->rx_handler;
1715 qp->tx_handler = handlers->tx_handler;
1716 qp->event_handler = handlers->event_handler;
1717
1718 dma_cap_zero(dma_mask);
1719 dma_cap_set(DMA_MEMCPY, dma_mask);
1720
1721 if (use_dma) {
1722 qp->tx_dma_chan =
1723 dma_request_channel(dma_mask, ntb_dma_filter_fn,
1724 (void *)(unsigned long)node);
1725 if (!qp->tx_dma_chan)
1726 dev_info(&pdev->dev, "Unable to allocate TX DMA channel\n");
1727
1728 qp->rx_dma_chan =
1729 dma_request_channel(dma_mask, ntb_dma_filter_fn,
1730 (void *)(unsigned long)node);
1731 if (!qp->rx_dma_chan)
1732 dev_info(&pdev->dev, "Unable to allocate RX DMA channel\n");
1733 } else {
1734 qp->tx_dma_chan = NULL;
1735 qp->rx_dma_chan = NULL;
1736 }
1737
1738 dev_dbg(&pdev->dev, "Using %s memcpy for TX\n",
1739 qp->tx_dma_chan ? "DMA" : "CPU");
1740
1741 dev_dbg(&pdev->dev, "Using %s memcpy for RX\n",
1742 qp->rx_dma_chan ? "DMA" : "CPU");
1743
1744 for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
1745 entry = kzalloc_node(sizeof(*entry), GFP_ATOMIC, node);
1746 if (!entry)
1747 goto err1;
1748
1749 entry->qp = qp;
1750 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry,
1751 &qp->rx_free_q);
1752 }
1753 qp->rx_alloc_entry = NTB_QP_DEF_NUM_ENTRIES;
1754
1755 for (i = 0; i < qp->tx_max_entry; i++) {
1756 entry = kzalloc_node(sizeof(*entry), GFP_ATOMIC, node);
1757 if (!entry)
1758 goto err2;
1759
1760 entry->qp = qp;
1761 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1762 &qp->tx_free_q);
1763 }
1764
1765 ntb_db_clear(qp->ndev, qp_bit);
1766 ntb_db_clear_mask(qp->ndev, qp_bit);
1767
1768 dev_info(&pdev->dev, "NTB Transport QP %d created\n", qp->qp_num);
1769
1770 return qp;
1771
1772 err2:
1773 while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1774 kfree(entry);
1775 err1:
1776 qp->rx_alloc_entry = 0;
1777 while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
1778 kfree(entry);
1779 if (qp->tx_dma_chan)
1780 dma_release_channel(qp->tx_dma_chan);
1781 if (qp->rx_dma_chan)
1782 dma_release_channel(qp->rx_dma_chan);
1783 nt->qp_bitmap_free |= qp_bit;
1784 err:
1785 return NULL;
1786 }
1787 EXPORT_SYMBOL_GPL(ntb_transport_create_queue);
1788
1789 /**
1790 * ntb_transport_free_queue - Frees NTB transport queue
1791 * @qp: NTB queue to be freed
1792 *
1793 * Frees NTB transport queue
1794 */
1795 void ntb_transport_free_queue(struct ntb_transport_qp *qp)
1796 {
1797 struct pci_dev *pdev;
1798 struct ntb_queue_entry *entry;
1799 u64 qp_bit;
1800
1801 if (!qp)
1802 return;
1803
1804 pdev = qp->ndev->pdev;
1805
1806 qp->active = false;
1807
1808 if (qp->tx_dma_chan) {
1809 struct dma_chan *chan = qp->tx_dma_chan;
1810 /* Putting the dma_chan to NULL will force any new traffic to be
1811 * processed by the CPU instead of the DAM engine
1812 */
1813 qp->tx_dma_chan = NULL;
1814
1815 /* Try to be nice and wait for any queued DMA engine
1816 * transactions to process before smashing it with a rock
1817 */
1818 dma_sync_wait(chan, qp->last_cookie);
1819 dmaengine_terminate_all(chan);
1820 dma_release_channel(chan);
1821 }
1822
1823 if (qp->rx_dma_chan) {
1824 struct dma_chan *chan = qp->rx_dma_chan;
1825 /* Putting the dma_chan to NULL will force any new traffic to be
1826 * processed by the CPU instead of the DAM engine
1827 */
1828 qp->rx_dma_chan = NULL;
1829
1830 /* Try to be nice and wait for any queued DMA engine
1831 * transactions to process before smashing it with a rock
1832 */
1833 dma_sync_wait(chan, qp->last_cookie);
1834 dmaengine_terminate_all(chan);
1835 dma_release_channel(chan);
1836 }
1837
1838 qp_bit = BIT_ULL(qp->qp_num);
1839
1840 ntb_db_set_mask(qp->ndev, qp_bit);
1841 tasklet_kill(&qp->rxc_db_work);
1842
1843 cancel_delayed_work_sync(&qp->link_work);
1844
1845 qp->cb_data = NULL;
1846 qp->rx_handler = NULL;
1847 qp->tx_handler = NULL;
1848 qp->event_handler = NULL;
1849
1850 while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
1851 kfree(entry);
1852
1853 while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_pend_q))) {
1854 dev_warn(&pdev->dev, "Freeing item from non-empty rx_pend_q\n");
1855 kfree(entry);
1856 }
1857
1858 while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_post_q))) {
1859 dev_warn(&pdev->dev, "Freeing item from non-empty rx_post_q\n");
1860 kfree(entry);
1861 }
1862
1863 while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1864 kfree(entry);
1865
1866 qp->transport->qp_bitmap_free |= qp_bit;
1867
1868 dev_info(&pdev->dev, "NTB Transport QP %d freed\n", qp->qp_num);
1869 }
1870 EXPORT_SYMBOL_GPL(ntb_transport_free_queue);
1871
1872 /**
1873 * ntb_transport_rx_remove - Dequeues enqueued rx packet
1874 * @qp: NTB queue to be freed
1875 * @len: pointer to variable to write enqueued buffers length
1876 *
1877 * Dequeues unused buffers from receive queue. Should only be used during
1878 * shutdown of qp.
1879 *
1880 * RETURNS: NULL error value on error, or void* for success.
1881 */
1882 void *ntb_transport_rx_remove(struct ntb_transport_qp *qp, unsigned int *len)
1883 {
1884 struct ntb_queue_entry *entry;
1885 void *buf;
1886
1887 if (!qp || qp->client_ready)
1888 return NULL;
1889
1890 entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_pend_q);
1891 if (!entry)
1892 return NULL;
1893
1894 buf = entry->cb_data;
1895 *len = entry->len;
1896
1897 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_free_q);
1898
1899 return buf;
1900 }
1901 EXPORT_SYMBOL_GPL(ntb_transport_rx_remove);
1902
1903 /**
1904 * ntb_transport_rx_enqueue - Enqueue a new NTB queue entry
1905 * @qp: NTB transport layer queue the entry is to be enqueued on
1906 * @cb: per buffer pointer for callback function to use
1907 * @data: pointer to data buffer that incoming packets will be copied into
1908 * @len: length of the data buffer
1909 *
1910 * Enqueue a new receive buffer onto the transport queue into which a NTB
1911 * payload can be received into.
1912 *
1913 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
1914 */
1915 int ntb_transport_rx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
1916 unsigned int len)
1917 {
1918 struct ntb_queue_entry *entry;
1919
1920 if (!qp)
1921 return -EINVAL;
1922
1923 entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q);
1924 if (!entry)
1925 return -ENOMEM;
1926
1927 entry->cb_data = cb;
1928 entry->buf = data;
1929 entry->len = len;
1930 entry->flags = 0;
1931
1932 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_pend_q);
1933
1934 if (qp->active)
1935 tasklet_schedule(&qp->rxc_db_work);
1936
1937 return 0;
1938 }
1939 EXPORT_SYMBOL_GPL(ntb_transport_rx_enqueue);
1940
1941 /**
1942 * ntb_transport_tx_enqueue - Enqueue a new NTB queue entry
1943 * @qp: NTB transport layer queue the entry is to be enqueued on
1944 * @cb: per buffer pointer for callback function to use
1945 * @data: pointer to data buffer that will be sent
1946 * @len: length of the data buffer
1947 *
1948 * Enqueue a new transmit buffer onto the transport queue from which a NTB
1949 * payload will be transmitted. This assumes that a lock is being held to
1950 * serialize access to the qp.
1951 *
1952 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
1953 */
1954 int ntb_transport_tx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
1955 unsigned int len)
1956 {
1957 struct ntb_queue_entry *entry;
1958 int rc;
1959
1960 if (!qp || !qp->link_is_up || !len)
1961 return -EINVAL;
1962
1963 entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1964 if (!entry) {
1965 qp->tx_err_no_buf++;
1966 return -EBUSY;
1967 }
1968
1969 entry->cb_data = cb;
1970 entry->buf = data;
1971 entry->len = len;
1972 entry->flags = 0;
1973
1974 rc = ntb_process_tx(qp, entry);
1975 if (rc)
1976 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1977 &qp->tx_free_q);
1978
1979 return rc;
1980 }
1981 EXPORT_SYMBOL_GPL(ntb_transport_tx_enqueue);
1982
1983 /**
1984 * ntb_transport_link_up - Notify NTB transport of client readiness to use queue
1985 * @qp: NTB transport layer queue to be enabled
1986 *
1987 * Notify NTB transport layer of client readiness to use queue
1988 */
1989 void ntb_transport_link_up(struct ntb_transport_qp *qp)
1990 {
1991 if (!qp)
1992 return;
1993
1994 qp->client_ready = true;
1995
1996 if (qp->transport->link_is_up)
1997 schedule_delayed_work(&qp->link_work, 0);
1998 }
1999 EXPORT_SYMBOL_GPL(ntb_transport_link_up);
2000
2001 /**
2002 * ntb_transport_link_down - Notify NTB transport to no longer enqueue data
2003 * @qp: NTB transport layer queue to be disabled
2004 *
2005 * Notify NTB transport layer of client's desire to no longer receive data on
2006 * transport queue specified. It is the client's responsibility to ensure all
2007 * entries on queue are purged or otherwise handled appropriately.
2008 */
2009 void ntb_transport_link_down(struct ntb_transport_qp *qp)
2010 {
2011 int val;
2012
2013 if (!qp)
2014 return;
2015
2016 qp->client_ready = false;
2017
2018 val = ntb_spad_read(qp->ndev, QP_LINKS);
2019
2020 ntb_peer_spad_write(qp->ndev, QP_LINKS,
2021 val & ~BIT(qp->qp_num));
2022
2023 if (qp->link_is_up)
2024 ntb_send_link_down(qp);
2025 else
2026 cancel_delayed_work_sync(&qp->link_work);
2027 }
2028 EXPORT_SYMBOL_GPL(ntb_transport_link_down);
2029
2030 /**
2031 * ntb_transport_link_query - Query transport link state
2032 * @qp: NTB transport layer queue to be queried
2033 *
2034 * Query connectivity to the remote system of the NTB transport queue
2035 *
2036 * RETURNS: true for link up or false for link down
2037 */
2038 bool ntb_transport_link_query(struct ntb_transport_qp *qp)
2039 {
2040 if (!qp)
2041 return false;
2042
2043 return qp->link_is_up;
2044 }
2045 EXPORT_SYMBOL_GPL(ntb_transport_link_query);
2046
2047 /**
2048 * ntb_transport_qp_num - Query the qp number
2049 * @qp: NTB transport layer queue to be queried
2050 *
2051 * Query qp number of the NTB transport queue
2052 *
2053 * RETURNS: a zero based number specifying the qp number
2054 */
2055 unsigned char ntb_transport_qp_num(struct ntb_transport_qp *qp)
2056 {
2057 if (!qp)
2058 return 0;
2059
2060 return qp->qp_num;
2061 }
2062 EXPORT_SYMBOL_GPL(ntb_transport_qp_num);
2063
2064 /**
2065 * ntb_transport_max_size - Query the max payload size of a qp
2066 * @qp: NTB transport layer queue to be queried
2067 *
2068 * Query the maximum payload size permissible on the given qp
2069 *
2070 * RETURNS: the max payload size of a qp
2071 */
2072 unsigned int ntb_transport_max_size(struct ntb_transport_qp *qp)
2073 {
2074 unsigned int max_size;
2075 unsigned int copy_align;
2076 struct dma_chan *rx_chan, *tx_chan;
2077
2078 if (!qp)
2079 return 0;
2080
2081 rx_chan = qp->rx_dma_chan;
2082 tx_chan = qp->tx_dma_chan;
2083
2084 copy_align = max(rx_chan ? rx_chan->device->copy_align : 0,
2085 tx_chan ? tx_chan->device->copy_align : 0);
2086
2087 /* If DMA engine usage is possible, try to find the max size for that */
2088 max_size = qp->tx_max_frame - sizeof(struct ntb_payload_header);
2089 max_size = round_down(max_size, 1 << copy_align);
2090
2091 return max_size;
2092 }
2093 EXPORT_SYMBOL_GPL(ntb_transport_max_size);
2094
2095 unsigned int ntb_transport_tx_free_entry(struct ntb_transport_qp *qp)
2096 {
2097 unsigned int head = qp->tx_index;
2098 unsigned int tail = qp->remote_rx_info->entry;
2099
2100 return tail > head ? tail - head : qp->tx_max_entry + tail - head;
2101 }
2102 EXPORT_SYMBOL_GPL(ntb_transport_tx_free_entry);
2103
2104 static void ntb_transport_doorbell_callback(void *data, int vector)
2105 {
2106 struct ntb_transport_ctx *nt = data;
2107 struct ntb_transport_qp *qp;
2108 u64 db_bits;
2109 unsigned int qp_num;
2110
2111 db_bits = (nt->qp_bitmap & ~nt->qp_bitmap_free &
2112 ntb_db_vector_mask(nt->ndev, vector));
2113
2114 while (db_bits) {
2115 qp_num = __ffs(db_bits);
2116 qp = &nt->qp_vec[qp_num];
2117
2118 if (qp->active)
2119 tasklet_schedule(&qp->rxc_db_work);
2120
2121 db_bits &= ~BIT_ULL(qp_num);
2122 }
2123 }
2124
2125 static const struct ntb_ctx_ops ntb_transport_ops = {
2126 .link_event = ntb_transport_event_callback,
2127 .db_event = ntb_transport_doorbell_callback,
2128 };
2129
2130 static struct ntb_client ntb_transport_client = {
2131 .ops = {
2132 .probe = ntb_transport_probe,
2133 .remove = ntb_transport_free,
2134 },
2135 };
2136
2137 static int __init ntb_transport_init(void)
2138 {
2139 int rc;
2140
2141 pr_info("%s, version %s\n", NTB_TRANSPORT_DESC, NTB_TRANSPORT_VER);
2142
2143 if (debugfs_initialized())
2144 nt_debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
2145
2146 rc = bus_register(&ntb_transport_bus);
2147 if (rc)
2148 goto err_bus;
2149
2150 rc = ntb_register_client(&ntb_transport_client);
2151 if (rc)
2152 goto err_client;
2153
2154 return 0;
2155
2156 err_client:
2157 bus_unregister(&ntb_transport_bus);
2158 err_bus:
2159 debugfs_remove_recursive(nt_debugfs_dir);
2160 return rc;
2161 }
2162 module_init(ntb_transport_init);
2163
2164 static void __exit ntb_transport_exit(void)
2165 {
2166 debugfs_remove_recursive(nt_debugfs_dir);
2167
2168 ntb_unregister_client(&ntb_transport_client);
2169 bus_unregister(&ntb_transport_bus);
2170 }
2171 module_exit(ntb_transport_exit);
Linux kernel - Deliverables
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