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[deliverable/linux.git] / drivers / ntb / ntb_transport.c
1 /*
2 * This file is provided under a dual BSD/GPLv2 license. When using or
3 * redistributing this file, you may do so under either license.
4 *
5 * GPL LICENSE SUMMARY
6 *
7 * Copyright(c) 2012 Intel Corporation. All rights reserved.
8 * 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 int retries;
106 int errors;
107 unsigned int tx_index;
108 unsigned int rx_index;
109
110 struct ntb_transport_qp *qp;
111 union {
112 struct ntb_payload_header __iomem *tx_hdr;
113 struct ntb_payload_header *rx_hdr;
114 };
115 };
116
117 struct ntb_rx_info {
118 unsigned int entry;
119 };
120
121 struct ntb_transport_qp {
122 struct ntb_transport_ctx *transport;
123 struct ntb_dev *ndev;
124 void *cb_data;
125 struct dma_chan *tx_dma_chan;
126 struct dma_chan *rx_dma_chan;
127
128 bool client_ready;
129 bool link_is_up;
130 bool active;
131
132 u8 qp_num; /* Only 64 QP's are allowed. 0-63 */
133 u64 qp_bit;
134
135 struct ntb_rx_info __iomem *rx_info;
136 struct ntb_rx_info *remote_rx_info;
137
138 void (*tx_handler)(struct ntb_transport_qp *qp, void *qp_data,
139 void *data, int len);
140 struct list_head tx_free_q;
141 spinlock_t ntb_tx_free_q_lock;
142 void __iomem *tx_mw;
143 dma_addr_t tx_mw_phys;
144 unsigned int tx_index;
145 unsigned int tx_max_entry;
146 unsigned int tx_max_frame;
147
148 void (*rx_handler)(struct ntb_transport_qp *qp, void *qp_data,
149 void *data, int len);
150 struct list_head rx_post_q;
151 struct list_head rx_pend_q;
152 struct list_head rx_free_q;
153 /* ntb_rx_q_lock: synchronize access to rx_XXXX_q */
154 spinlock_t ntb_rx_q_lock;
155 void *rx_buff;
156 unsigned int rx_index;
157 unsigned int rx_max_entry;
158 unsigned int rx_max_frame;
159 unsigned int rx_alloc_entry;
160 dma_cookie_t last_cookie;
161 struct tasklet_struct rxc_db_work;
162
163 void (*event_handler)(void *data, int status);
164 struct delayed_work link_work;
165 struct work_struct link_cleanup;
166
167 struct dentry *debugfs_dir;
168 struct dentry *debugfs_stats;
169
170 /* Stats */
171 u64 rx_bytes;
172 u64 rx_pkts;
173 u64 rx_ring_empty;
174 u64 rx_err_no_buf;
175 u64 rx_err_oflow;
176 u64 rx_err_ver;
177 u64 rx_memcpy;
178 u64 rx_async;
179 u64 dma_rx_prep_err;
180 u64 tx_bytes;
181 u64 tx_pkts;
182 u64 tx_ring_full;
183 u64 tx_err_no_buf;
184 u64 tx_memcpy;
185 u64 tx_async;
186 u64 dma_tx_prep_err;
187 };
188
189 struct ntb_transport_mw {
190 phys_addr_t phys_addr;
191 resource_size_t phys_size;
192 resource_size_t xlat_align;
193 resource_size_t xlat_align_size;
194 void __iomem *vbase;
195 size_t xlat_size;
196 size_t buff_size;
197 void *virt_addr;
198 dma_addr_t dma_addr;
199 };
200
201 struct ntb_transport_client_dev {
202 struct list_head entry;
203 struct ntb_transport_ctx *nt;
204 struct device dev;
205 };
206
207 struct ntb_transport_ctx {
208 struct list_head entry;
209 struct list_head client_devs;
210
211 struct ntb_dev *ndev;
212
213 struct ntb_transport_mw *mw_vec;
214 struct ntb_transport_qp *qp_vec;
215 unsigned int mw_count;
216 unsigned int qp_count;
217 u64 qp_bitmap;
218 u64 qp_bitmap_free;
219
220 bool link_is_up;
221 struct delayed_work link_work;
222 struct work_struct link_cleanup;
223
224 struct dentry *debugfs_node_dir;
225 };
226
227 enum {
228 DESC_DONE_FLAG = BIT(0),
229 LINK_DOWN_FLAG = BIT(1),
230 };
231
232 struct ntb_payload_header {
233 unsigned int ver;
234 unsigned int len;
235 unsigned int flags;
236 };
237
238 enum {
239 VERSION = 0,
240 QP_LINKS,
241 NUM_QPS,
242 NUM_MWS,
243 MW0_SZ_HIGH,
244 MW0_SZ_LOW,
245 MW1_SZ_HIGH,
246 MW1_SZ_LOW,
247 MAX_SPAD,
248 };
249
250 #define dev_client_dev(__dev) \
251 container_of((__dev), struct ntb_transport_client_dev, dev)
252
253 #define drv_client(__drv) \
254 container_of((__drv), struct ntb_transport_client, driver)
255
256 #define QP_TO_MW(nt, qp) ((qp) % nt->mw_count)
257 #define NTB_QP_DEF_NUM_ENTRIES 100
258 #define NTB_LINK_DOWN_TIMEOUT 10
259 #define DMA_RETRIES 20
260 #define DMA_OUT_RESOURCE_TO 50
261
262 static void ntb_transport_rxc_db(unsigned long data);
263 static const struct ntb_ctx_ops ntb_transport_ops;
264 static struct ntb_client ntb_transport_client;
265 static int ntb_async_tx_submit(struct ntb_transport_qp *qp,
266 struct ntb_queue_entry *entry);
267 static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset);
268 static int ntb_async_rx_submit(struct ntb_queue_entry *entry, void *offset);
269 static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void *offset);
270
271
272 static int ntb_transport_bus_match(struct device *dev,
273 struct device_driver *drv)
274 {
275 return !strncmp(dev_name(dev), drv->name, strlen(drv->name));
276 }
277
278 static int ntb_transport_bus_probe(struct device *dev)
279 {
280 const struct ntb_transport_client *client;
281 int rc = -EINVAL;
282
283 get_device(dev);
284
285 client = drv_client(dev->driver);
286 rc = client->probe(dev);
287 if (rc)
288 put_device(dev);
289
290 return rc;
291 }
292
293 static int ntb_transport_bus_remove(struct device *dev)
294 {
295 const struct ntb_transport_client *client;
296
297 client = drv_client(dev->driver);
298 client->remove(dev);
299
300 put_device(dev);
301
302 return 0;
303 }
304
305 static struct bus_type ntb_transport_bus = {
306 .name = "ntb_transport",
307 .match = ntb_transport_bus_match,
308 .probe = ntb_transport_bus_probe,
309 .remove = ntb_transport_bus_remove,
310 };
311
312 static LIST_HEAD(ntb_transport_list);
313
314 static int ntb_bus_init(struct ntb_transport_ctx *nt)
315 {
316 list_add_tail(&nt->entry, &ntb_transport_list);
317 return 0;
318 }
319
320 static void ntb_bus_remove(struct ntb_transport_ctx *nt)
321 {
322 struct ntb_transport_client_dev *client_dev, *cd;
323
324 list_for_each_entry_safe(client_dev, cd, &nt->client_devs, entry) {
325 dev_err(client_dev->dev.parent, "%s still attached to bus, removing\n",
326 dev_name(&client_dev->dev));
327 list_del(&client_dev->entry);
328 device_unregister(&client_dev->dev);
329 }
330
331 list_del(&nt->entry);
332 }
333
334 static void ntb_transport_client_release(struct device *dev)
335 {
336 struct ntb_transport_client_dev *client_dev;
337
338 client_dev = dev_client_dev(dev);
339 kfree(client_dev);
340 }
341
342 /**
343 * ntb_transport_unregister_client_dev - Unregister NTB client device
344 * @device_name: Name of NTB client device
345 *
346 * Unregister an NTB client device with the NTB transport layer
347 */
348 void ntb_transport_unregister_client_dev(char *device_name)
349 {
350 struct ntb_transport_client_dev *client, *cd;
351 struct ntb_transport_ctx *nt;
352
353 list_for_each_entry(nt, &ntb_transport_list, entry)
354 list_for_each_entry_safe(client, cd, &nt->client_devs, entry)
355 if (!strncmp(dev_name(&client->dev), device_name,
356 strlen(device_name))) {
357 list_del(&client->entry);
358 device_unregister(&client->dev);
359 }
360 }
361 EXPORT_SYMBOL_GPL(ntb_transport_unregister_client_dev);
362
363 /**
364 * ntb_transport_register_client_dev - Register NTB client device
365 * @device_name: Name of NTB client device
366 *
367 * Register an NTB client device with the NTB transport layer
368 */
369 int ntb_transport_register_client_dev(char *device_name)
370 {
371 struct ntb_transport_client_dev *client_dev;
372 struct ntb_transport_ctx *nt;
373 int node;
374 int rc, i = 0;
375
376 if (list_empty(&ntb_transport_list))
377 return -ENODEV;
378
379 list_for_each_entry(nt, &ntb_transport_list, entry) {
380 struct device *dev;
381
382 node = dev_to_node(&nt->ndev->dev);
383
384 client_dev = kzalloc_node(sizeof(*client_dev),
385 GFP_KERNEL, node);
386 if (!client_dev) {
387 rc = -ENOMEM;
388 goto err;
389 }
390
391 dev = &client_dev->dev;
392
393 /* setup and register client devices */
394 dev_set_name(dev, "%s%d", device_name, i);
395 dev->bus = &ntb_transport_bus;
396 dev->release = ntb_transport_client_release;
397 dev->parent = &nt->ndev->dev;
398
399 rc = device_register(dev);
400 if (rc) {
401 kfree(client_dev);
402 goto err;
403 }
404
405 list_add_tail(&client_dev->entry, &nt->client_devs);
406 i++;
407 }
408
409 return 0;
410
411 err:
412 ntb_transport_unregister_client_dev(device_name);
413
414 return rc;
415 }
416 EXPORT_SYMBOL_GPL(ntb_transport_register_client_dev);
417
418 /**
419 * ntb_transport_register_client - Register NTB client driver
420 * @drv: NTB client driver to be registered
421 *
422 * Register an NTB client driver with the NTB transport layer
423 *
424 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
425 */
426 int ntb_transport_register_client(struct ntb_transport_client *drv)
427 {
428 drv->driver.bus = &ntb_transport_bus;
429
430 if (list_empty(&ntb_transport_list))
431 return -ENODEV;
432
433 return driver_register(&drv->driver);
434 }
435 EXPORT_SYMBOL_GPL(ntb_transport_register_client);
436
437 /**
438 * ntb_transport_unregister_client - Unregister NTB client driver
439 * @drv: NTB client driver to be unregistered
440 *
441 * Unregister an NTB client driver with the NTB transport layer
442 *
443 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
444 */
445 void ntb_transport_unregister_client(struct ntb_transport_client *drv)
446 {
447 driver_unregister(&drv->driver);
448 }
449 EXPORT_SYMBOL_GPL(ntb_transport_unregister_client);
450
451 static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count,
452 loff_t *offp)
453 {
454 struct ntb_transport_qp *qp;
455 char *buf;
456 ssize_t ret, out_offset, out_count;
457
458 qp = filp->private_data;
459
460 if (!qp || !qp->link_is_up)
461 return 0;
462
463 out_count = 1000;
464
465 buf = kmalloc(out_count, GFP_KERNEL);
466 if (!buf)
467 return -ENOMEM;
468
469 out_offset = 0;
470 out_offset += snprintf(buf + out_offset, out_count - out_offset,
471 "\nNTB QP stats:\n\n");
472 out_offset += snprintf(buf + out_offset, out_count - out_offset,
473 "rx_bytes - \t%llu\n", qp->rx_bytes);
474 out_offset += snprintf(buf + out_offset, out_count - out_offset,
475 "rx_pkts - \t%llu\n", qp->rx_pkts);
476 out_offset += snprintf(buf + out_offset, out_count - out_offset,
477 "rx_memcpy - \t%llu\n", qp->rx_memcpy);
478 out_offset += snprintf(buf + out_offset, out_count - out_offset,
479 "rx_async - \t%llu\n", qp->rx_async);
480 out_offset += snprintf(buf + out_offset, out_count - out_offset,
481 "rx_ring_empty - %llu\n", qp->rx_ring_empty);
482 out_offset += snprintf(buf + out_offset, out_count - out_offset,
483 "rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
484 out_offset += snprintf(buf + out_offset, out_count - out_offset,
485 "rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
486 out_offset += snprintf(buf + out_offset, out_count - out_offset,
487 "rx_err_ver - \t%llu\n", qp->rx_err_ver);
488 out_offset += snprintf(buf + out_offset, out_count - out_offset,
489 "rx_buff - \t0x%p\n", qp->rx_buff);
490 out_offset += snprintf(buf + out_offset, out_count - out_offset,
491 "rx_index - \t%u\n", qp->rx_index);
492 out_offset += snprintf(buf + out_offset, out_count - out_offset,
493 "rx_max_entry - \t%u\n", qp->rx_max_entry);
494 out_offset += snprintf(buf + out_offset, out_count - out_offset,
495 "rx_alloc_entry - \t%u\n\n", qp->rx_alloc_entry);
496
497 out_offset += snprintf(buf + out_offset, out_count - out_offset,
498 "tx_bytes - \t%llu\n", qp->tx_bytes);
499 out_offset += snprintf(buf + out_offset, out_count - out_offset,
500 "tx_pkts - \t%llu\n", qp->tx_pkts);
501 out_offset += snprintf(buf + out_offset, out_count - out_offset,
502 "tx_memcpy - \t%llu\n", qp->tx_memcpy);
503 out_offset += snprintf(buf + out_offset, out_count - out_offset,
504 "tx_async - \t%llu\n", qp->tx_async);
505 out_offset += snprintf(buf + out_offset, out_count - out_offset,
506 "tx_ring_full - \t%llu\n", qp->tx_ring_full);
507 out_offset += snprintf(buf + out_offset, out_count - out_offset,
508 "tx_err_no_buf - %llu\n", qp->tx_err_no_buf);
509 out_offset += snprintf(buf + out_offset, out_count - out_offset,
510 "tx_mw - \t0x%p\n", qp->tx_mw);
511 out_offset += snprintf(buf + out_offset, out_count - out_offset,
512 "tx_index (H) - \t%u\n", qp->tx_index);
513 out_offset += snprintf(buf + out_offset, out_count - out_offset,
514 "RRI (T) - \t%u\n",
515 qp->remote_rx_info->entry);
516 out_offset += snprintf(buf + out_offset, out_count - out_offset,
517 "tx_max_entry - \t%u\n", qp->tx_max_entry);
518 out_offset += snprintf(buf + out_offset, out_count - out_offset,
519 "free tx - \t%u\n",
520 ntb_transport_tx_free_entry(qp));
521 out_offset += snprintf(buf + out_offset, out_count - out_offset,
522 "DMA tx prep err - \t%llu\n",
523 qp->dma_tx_prep_err);
524 out_offset += snprintf(buf + out_offset, out_count - out_offset,
525 "DMA rx prep err - \t%llu\n",
526 qp->dma_rx_prep_err);
527
528 out_offset += snprintf(buf + out_offset, out_count - out_offset,
529 "\n");
530 out_offset += snprintf(buf + out_offset, out_count - out_offset,
531 "Using TX DMA - \t%s\n",
532 qp->tx_dma_chan ? "Yes" : "No");
533 out_offset += snprintf(buf + out_offset, out_count - out_offset,
534 "Using RX DMA - \t%s\n",
535 qp->rx_dma_chan ? "Yes" : "No");
536 out_offset += snprintf(buf + out_offset, out_count - out_offset,
537 "QP Link - \t%s\n",
538 qp->link_is_up ? "Up" : "Down");
539 out_offset += snprintf(buf + out_offset, out_count - out_offset,
540 "\n");
541
542 if (out_offset > out_count)
543 out_offset = out_count;
544
545 ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
546 kfree(buf);
547 return ret;
548 }
549
550 static const struct file_operations ntb_qp_debugfs_stats = {
551 .owner = THIS_MODULE,
552 .open = simple_open,
553 .read = debugfs_read,
554 };
555
556 static void ntb_list_add(spinlock_t *lock, struct list_head *entry,
557 struct list_head *list)
558 {
559 unsigned long flags;
560
561 spin_lock_irqsave(lock, flags);
562 list_add_tail(entry, list);
563 spin_unlock_irqrestore(lock, flags);
564 }
565
566 static struct ntb_queue_entry *ntb_list_rm(spinlock_t *lock,
567 struct list_head *list)
568 {
569 struct ntb_queue_entry *entry;
570 unsigned long flags;
571
572 spin_lock_irqsave(lock, flags);
573 if (list_empty(list)) {
574 entry = NULL;
575 goto out;
576 }
577 entry = list_first_entry(list, struct ntb_queue_entry, entry);
578 list_del(&entry->entry);
579
580 out:
581 spin_unlock_irqrestore(lock, flags);
582
583 return entry;
584 }
585
586 static struct ntb_queue_entry *ntb_list_mv(spinlock_t *lock,
587 struct list_head *list,
588 struct list_head *to_list)
589 {
590 struct ntb_queue_entry *entry;
591 unsigned long flags;
592
593 spin_lock_irqsave(lock, flags);
594
595 if (list_empty(list)) {
596 entry = NULL;
597 } else {
598 entry = list_first_entry(list, struct ntb_queue_entry, entry);
599 list_move_tail(&entry->entry, to_list);
600 }
601
602 spin_unlock_irqrestore(lock, flags);
603
604 return entry;
605 }
606
607 static int ntb_transport_setup_qp_mw(struct ntb_transport_ctx *nt,
608 unsigned int qp_num)
609 {
610 struct ntb_transport_qp *qp = &nt->qp_vec[qp_num];
611 struct ntb_transport_mw *mw;
612 struct ntb_dev *ndev = nt->ndev;
613 struct ntb_queue_entry *entry;
614 unsigned int rx_size, num_qps_mw;
615 unsigned int mw_num, mw_count, qp_count;
616 unsigned int i;
617 int node;
618
619 mw_count = nt->mw_count;
620 qp_count = nt->qp_count;
621
622 mw_num = QP_TO_MW(nt, qp_num);
623 mw = &nt->mw_vec[mw_num];
624
625 if (!mw->virt_addr)
626 return -ENOMEM;
627
628 if (qp_count % mw_count && mw_num + 1 < qp_count / mw_count)
629 num_qps_mw = qp_count / mw_count + 1;
630 else
631 num_qps_mw = qp_count / mw_count;
632
633 rx_size = (unsigned int)mw->xlat_size / num_qps_mw;
634 qp->rx_buff = mw->virt_addr + rx_size * (qp_num / mw_count);
635 rx_size -= sizeof(struct ntb_rx_info);
636
637 qp->remote_rx_info = qp->rx_buff + rx_size;
638
639 /* Due to housekeeping, there must be atleast 2 buffs */
640 qp->rx_max_frame = min(transport_mtu, rx_size / 2);
641 qp->rx_max_entry = rx_size / qp->rx_max_frame;
642 qp->rx_index = 0;
643
644 /*
645 * Checking to see if we have more entries than the default.
646 * We should add additional entries if that is the case so we
647 * can be in sync with the transport frames.
648 */
649 node = dev_to_node(&ndev->dev);
650 for (i = qp->rx_alloc_entry; i < qp->rx_max_entry; i++) {
651 entry = kzalloc_node(sizeof(*entry), GFP_ATOMIC, node);
652 if (!entry)
653 return -ENOMEM;
654
655 entry->qp = qp;
656 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry,
657 &qp->rx_free_q);
658 qp->rx_alloc_entry++;
659 }
660
661 qp->remote_rx_info->entry = qp->rx_max_entry - 1;
662
663 /* setup the hdr offsets with 0's */
664 for (i = 0; i < qp->rx_max_entry; i++) {
665 void *offset = (qp->rx_buff + qp->rx_max_frame * (i + 1) -
666 sizeof(struct ntb_payload_header));
667 memset(offset, 0, sizeof(struct ntb_payload_header));
668 }
669
670 qp->rx_pkts = 0;
671 qp->tx_pkts = 0;
672 qp->tx_index = 0;
673
674 return 0;
675 }
676
677 static void ntb_free_mw(struct ntb_transport_ctx *nt, int num_mw)
678 {
679 struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
680 struct pci_dev *pdev = nt->ndev->pdev;
681
682 if (!mw->virt_addr)
683 return;
684
685 ntb_mw_clear_trans(nt->ndev, num_mw);
686 dma_free_coherent(&pdev->dev, mw->buff_size,
687 mw->virt_addr, mw->dma_addr);
688 mw->xlat_size = 0;
689 mw->buff_size = 0;
690 mw->virt_addr = NULL;
691 }
692
693 static int ntb_set_mw(struct ntb_transport_ctx *nt, int num_mw,
694 resource_size_t size)
695 {
696 struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
697 struct pci_dev *pdev = nt->ndev->pdev;
698 size_t xlat_size, buff_size;
699 int rc;
700
701 if (!size)
702 return -EINVAL;
703
704 xlat_size = round_up(size, mw->xlat_align_size);
705 buff_size = round_up(size, mw->xlat_align);
706
707 /* No need to re-setup */
708 if (mw->xlat_size == xlat_size)
709 return 0;
710
711 if (mw->buff_size)
712 ntb_free_mw(nt, num_mw);
713
714 /* Alloc memory for receiving data. Must be aligned */
715 mw->xlat_size = xlat_size;
716 mw->buff_size = buff_size;
717
718 mw->virt_addr = dma_alloc_coherent(&pdev->dev, buff_size,
719 &mw->dma_addr, GFP_KERNEL);
720 if (!mw->virt_addr) {
721 mw->xlat_size = 0;
722 mw->buff_size = 0;
723 dev_err(&pdev->dev, "Unable to alloc MW buff of size %zu\n",
724 buff_size);
725 return -ENOMEM;
726 }
727
728 /*
729 * we must ensure that the memory address allocated is BAR size
730 * aligned in order for the XLAT register to take the value. This
731 * is a requirement of the hardware. It is recommended to setup CMA
732 * for BAR sizes equal or greater than 4MB.
733 */
734 if (!IS_ALIGNED(mw->dma_addr, mw->xlat_align)) {
735 dev_err(&pdev->dev, "DMA memory %pad is not aligned\n",
736 &mw->dma_addr);
737 ntb_free_mw(nt, num_mw);
738 return -ENOMEM;
739 }
740
741 /* Notify HW the memory location of the receive buffer */
742 rc = ntb_mw_set_trans(nt->ndev, num_mw, mw->dma_addr, mw->xlat_size);
743 if (rc) {
744 dev_err(&pdev->dev, "Unable to set mw%d translation", num_mw);
745 ntb_free_mw(nt, num_mw);
746 return -EIO;
747 }
748
749 return 0;
750 }
751
752 static void ntb_qp_link_down_reset(struct ntb_transport_qp *qp)
753 {
754 qp->link_is_up = false;
755 qp->active = false;
756
757 qp->tx_index = 0;
758 qp->rx_index = 0;
759 qp->rx_bytes = 0;
760 qp->rx_pkts = 0;
761 qp->rx_ring_empty = 0;
762 qp->rx_err_no_buf = 0;
763 qp->rx_err_oflow = 0;
764 qp->rx_err_ver = 0;
765 qp->rx_memcpy = 0;
766 qp->rx_async = 0;
767 qp->tx_bytes = 0;
768 qp->tx_pkts = 0;
769 qp->tx_ring_full = 0;
770 qp->tx_err_no_buf = 0;
771 qp->tx_memcpy = 0;
772 qp->tx_async = 0;
773 qp->dma_tx_prep_err = 0;
774 qp->dma_rx_prep_err = 0;
775 }
776
777 static void ntb_qp_link_cleanup(struct ntb_transport_qp *qp)
778 {
779 struct ntb_transport_ctx *nt = qp->transport;
780 struct pci_dev *pdev = nt->ndev->pdev;
781
782 dev_info(&pdev->dev, "qp %d: Link Cleanup\n", qp->qp_num);
783
784 cancel_delayed_work_sync(&qp->link_work);
785 ntb_qp_link_down_reset(qp);
786
787 if (qp->event_handler)
788 qp->event_handler(qp->cb_data, qp->link_is_up);
789 }
790
791 static void ntb_qp_link_cleanup_work(struct work_struct *work)
792 {
793 struct ntb_transport_qp *qp = container_of(work,
794 struct ntb_transport_qp,
795 link_cleanup);
796 struct ntb_transport_ctx *nt = qp->transport;
797
798 ntb_qp_link_cleanup(qp);
799
800 if (nt->link_is_up)
801 schedule_delayed_work(&qp->link_work,
802 msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
803 }
804
805 static void ntb_qp_link_down(struct ntb_transport_qp *qp)
806 {
807 schedule_work(&qp->link_cleanup);
808 }
809
810 static void ntb_transport_link_cleanup(struct ntb_transport_ctx *nt)
811 {
812 struct ntb_transport_qp *qp;
813 u64 qp_bitmap_alloc;
814 int i;
815
816 qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
817
818 /* Pass along the info to any clients */
819 for (i = 0; i < nt->qp_count; i++)
820 if (qp_bitmap_alloc & BIT_ULL(i)) {
821 qp = &nt->qp_vec[i];
822 ntb_qp_link_cleanup(qp);
823 cancel_work_sync(&qp->link_cleanup);
824 cancel_delayed_work_sync(&qp->link_work);
825 }
826
827 if (!nt->link_is_up)
828 cancel_delayed_work_sync(&nt->link_work);
829
830 /* The scratchpad registers keep the values if the remote side
831 * goes down, blast them now to give them a sane value the next
832 * time they are accessed
833 */
834 for (i = 0; i < MAX_SPAD; i++)
835 ntb_spad_write(nt->ndev, i, 0);
836 }
837
838 static void ntb_transport_link_cleanup_work(struct work_struct *work)
839 {
840 struct ntb_transport_ctx *nt =
841 container_of(work, struct ntb_transport_ctx, link_cleanup);
842
843 ntb_transport_link_cleanup(nt);
844 }
845
846 static void ntb_transport_event_callback(void *data)
847 {
848 struct ntb_transport_ctx *nt = data;
849
850 if (ntb_link_is_up(nt->ndev, NULL, NULL) == 1)
851 schedule_delayed_work(&nt->link_work, 0);
852 else
853 schedule_work(&nt->link_cleanup);
854 }
855
856 static void ntb_transport_link_work(struct work_struct *work)
857 {
858 struct ntb_transport_ctx *nt =
859 container_of(work, struct ntb_transport_ctx, link_work.work);
860 struct ntb_dev *ndev = nt->ndev;
861 struct pci_dev *pdev = ndev->pdev;
862 resource_size_t size;
863 u32 val;
864 int rc = 0, i, spad;
865
866 /* send the local info, in the opposite order of the way we read it */
867 for (i = 0; i < nt->mw_count; i++) {
868 size = nt->mw_vec[i].phys_size;
869
870 if (max_mw_size && size > max_mw_size)
871 size = max_mw_size;
872
873 spad = MW0_SZ_HIGH + (i * 2);
874 ntb_peer_spad_write(ndev, spad, upper_32_bits(size));
875
876 spad = MW0_SZ_LOW + (i * 2);
877 ntb_peer_spad_write(ndev, spad, lower_32_bits(size));
878 }
879
880 ntb_peer_spad_write(ndev, NUM_MWS, nt->mw_count);
881
882 ntb_peer_spad_write(ndev, NUM_QPS, nt->qp_count);
883
884 ntb_peer_spad_write(ndev, VERSION, NTB_TRANSPORT_VERSION);
885
886 /* Query the remote side for its info */
887 val = ntb_spad_read(ndev, VERSION);
888 dev_dbg(&pdev->dev, "Remote version = %d\n", val);
889 if (val != NTB_TRANSPORT_VERSION)
890 goto out;
891
892 val = ntb_spad_read(ndev, NUM_QPS);
893 dev_dbg(&pdev->dev, "Remote max number of qps = %d\n", val);
894 if (val != nt->qp_count)
895 goto out;
896
897 val = ntb_spad_read(ndev, NUM_MWS);
898 dev_dbg(&pdev->dev, "Remote number of mws = %d\n", val);
899 if (val != nt->mw_count)
900 goto out;
901
902 for (i = 0; i < nt->mw_count; i++) {
903 u64 val64;
904
905 val = ntb_spad_read(ndev, MW0_SZ_HIGH + (i * 2));
906 val64 = (u64)val << 32;
907
908 val = ntb_spad_read(ndev, MW0_SZ_LOW + (i * 2));
909 val64 |= val;
910
911 dev_dbg(&pdev->dev, "Remote MW%d size = %#llx\n", i, val64);
912
913 rc = ntb_set_mw(nt, i, val64);
914 if (rc)
915 goto out1;
916 }
917
918 nt->link_is_up = true;
919
920 for (i = 0; i < nt->qp_count; i++) {
921 struct ntb_transport_qp *qp = &nt->qp_vec[i];
922
923 ntb_transport_setup_qp_mw(nt, i);
924
925 if (qp->client_ready)
926 schedule_delayed_work(&qp->link_work, 0);
927 }
928
929 return;
930
931 out1:
932 for (i = 0; i < nt->mw_count; i++)
933 ntb_free_mw(nt, i);
934
935 /* if there's an actual failure, we should just bail */
936 if (rc < 0) {
937 ntb_link_disable(ndev);
938 return;
939 }
940
941 out:
942 if (ntb_link_is_up(ndev, NULL, NULL) == 1)
943 schedule_delayed_work(&nt->link_work,
944 msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
945 }
946
947 static void ntb_qp_link_work(struct work_struct *work)
948 {
949 struct ntb_transport_qp *qp = container_of(work,
950 struct ntb_transport_qp,
951 link_work.work);
952 struct pci_dev *pdev = qp->ndev->pdev;
953 struct ntb_transport_ctx *nt = qp->transport;
954 int val;
955
956 WARN_ON(!nt->link_is_up);
957
958 val = ntb_spad_read(nt->ndev, QP_LINKS);
959
960 ntb_peer_spad_write(nt->ndev, QP_LINKS, val | BIT(qp->qp_num));
961
962 /* query remote spad for qp ready bits */
963 ntb_peer_spad_read(nt->ndev, QP_LINKS);
964 dev_dbg_ratelimited(&pdev->dev, "Remote QP link status = %x\n", val);
965
966 /* See if the remote side is up */
967 if (val & BIT(qp->qp_num)) {
968 dev_info(&pdev->dev, "qp %d: Link Up\n", qp->qp_num);
969 qp->link_is_up = true;
970 qp->active = true;
971
972 if (qp->event_handler)
973 qp->event_handler(qp->cb_data, qp->link_is_up);
974
975 if (qp->active)
976 tasklet_schedule(&qp->rxc_db_work);
977 } else if (nt->link_is_up)
978 schedule_delayed_work(&qp->link_work,
979 msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
980 }
981
982 static int ntb_transport_init_queue(struct ntb_transport_ctx *nt,
983 unsigned int qp_num)
984 {
985 struct ntb_transport_qp *qp;
986 phys_addr_t mw_base;
987 resource_size_t mw_size;
988 unsigned int num_qps_mw, tx_size;
989 unsigned int mw_num, mw_count, qp_count;
990 u64 qp_offset;
991
992 mw_count = nt->mw_count;
993 qp_count = nt->qp_count;
994
995 mw_num = QP_TO_MW(nt, qp_num);
996
997 qp = &nt->qp_vec[qp_num];
998 qp->qp_num = qp_num;
999 qp->transport = nt;
1000 qp->ndev = nt->ndev;
1001 qp->client_ready = false;
1002 qp->event_handler = NULL;
1003 ntb_qp_link_down_reset(qp);
1004
1005 if (qp_count % mw_count && mw_num + 1 < qp_count / mw_count)
1006 num_qps_mw = qp_count / mw_count + 1;
1007 else
1008 num_qps_mw = qp_count / mw_count;
1009
1010 mw_base = nt->mw_vec[mw_num].phys_addr;
1011 mw_size = nt->mw_vec[mw_num].phys_size;
1012
1013 tx_size = (unsigned int)mw_size / num_qps_mw;
1014 qp_offset = tx_size * (qp_num / mw_count);
1015
1016 qp->tx_mw = nt->mw_vec[mw_num].vbase + qp_offset;
1017 if (!qp->tx_mw)
1018 return -EINVAL;
1019
1020 qp->tx_mw_phys = mw_base + qp_offset;
1021 if (!qp->tx_mw_phys)
1022 return -EINVAL;
1023
1024 tx_size -= sizeof(struct ntb_rx_info);
1025 qp->rx_info = qp->tx_mw + tx_size;
1026
1027 /* Due to housekeeping, there must be atleast 2 buffs */
1028 qp->tx_max_frame = min(transport_mtu, tx_size / 2);
1029 qp->tx_max_entry = tx_size / qp->tx_max_frame;
1030
1031 if (nt->debugfs_node_dir) {
1032 char debugfs_name[4];
1033
1034 snprintf(debugfs_name, 4, "qp%d", qp_num);
1035 qp->debugfs_dir = debugfs_create_dir(debugfs_name,
1036 nt->debugfs_node_dir);
1037
1038 qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR,
1039 qp->debugfs_dir, qp,
1040 &ntb_qp_debugfs_stats);
1041 } else {
1042 qp->debugfs_dir = NULL;
1043 qp->debugfs_stats = NULL;
1044 }
1045
1046 INIT_DELAYED_WORK(&qp->link_work, ntb_qp_link_work);
1047 INIT_WORK(&qp->link_cleanup, ntb_qp_link_cleanup_work);
1048
1049 spin_lock_init(&qp->ntb_rx_q_lock);
1050 spin_lock_init(&qp->ntb_tx_free_q_lock);
1051
1052 INIT_LIST_HEAD(&qp->rx_post_q);
1053 INIT_LIST_HEAD(&qp->rx_pend_q);
1054 INIT_LIST_HEAD(&qp->rx_free_q);
1055 INIT_LIST_HEAD(&qp->tx_free_q);
1056
1057 tasklet_init(&qp->rxc_db_work, ntb_transport_rxc_db,
1058 (unsigned long)qp);
1059
1060 return 0;
1061 }
1062
1063 static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev)
1064 {
1065 struct ntb_transport_ctx *nt;
1066 struct ntb_transport_mw *mw;
1067 unsigned int mw_count, qp_count;
1068 u64 qp_bitmap;
1069 int node;
1070 int rc, i;
1071
1072 mw_count = ntb_mw_count(ndev);
1073 if (ntb_spad_count(ndev) < (NUM_MWS + 1 + mw_count * 2)) {
1074 dev_err(&ndev->dev, "Not enough scratch pad registers for %s",
1075 NTB_TRANSPORT_NAME);
1076 return -EIO;
1077 }
1078
1079 if (ntb_db_is_unsafe(ndev))
1080 dev_dbg(&ndev->dev,
1081 "doorbell is unsafe, proceed anyway...\n");
1082 if (ntb_spad_is_unsafe(ndev))
1083 dev_dbg(&ndev->dev,
1084 "scratchpad is unsafe, proceed anyway...\n");
1085
1086 node = dev_to_node(&ndev->dev);
1087
1088 nt = kzalloc_node(sizeof(*nt), GFP_KERNEL, node);
1089 if (!nt)
1090 return -ENOMEM;
1091
1092 nt->ndev = ndev;
1093
1094 nt->mw_count = mw_count;
1095
1096 nt->mw_vec = kzalloc_node(mw_count * sizeof(*nt->mw_vec),
1097 GFP_KERNEL, node);
1098 if (!nt->mw_vec) {
1099 rc = -ENOMEM;
1100 goto err;
1101 }
1102
1103 for (i = 0; i < mw_count; i++) {
1104 mw = &nt->mw_vec[i];
1105
1106 rc = ntb_mw_get_range(ndev, i, &mw->phys_addr, &mw->phys_size,
1107 &mw->xlat_align, &mw->xlat_align_size);
1108 if (rc)
1109 goto err1;
1110
1111 mw->vbase = ioremap_wc(mw->phys_addr, mw->phys_size);
1112 if (!mw->vbase) {
1113 rc = -ENOMEM;
1114 goto err1;
1115 }
1116
1117 mw->buff_size = 0;
1118 mw->xlat_size = 0;
1119 mw->virt_addr = NULL;
1120 mw->dma_addr = 0;
1121 }
1122
1123 qp_bitmap = ntb_db_valid_mask(ndev);
1124
1125 qp_count = ilog2(qp_bitmap);
1126 if (max_num_clients && max_num_clients < qp_count)
1127 qp_count = max_num_clients;
1128 else if (mw_count < qp_count)
1129 qp_count = mw_count;
1130
1131 qp_bitmap &= BIT_ULL(qp_count) - 1;
1132
1133 nt->qp_count = qp_count;
1134 nt->qp_bitmap = qp_bitmap;
1135 nt->qp_bitmap_free = qp_bitmap;
1136
1137 nt->qp_vec = kzalloc_node(qp_count * sizeof(*nt->qp_vec),
1138 GFP_KERNEL, node);
1139 if (!nt->qp_vec) {
1140 rc = -ENOMEM;
1141 goto err1;
1142 }
1143
1144 if (nt_debugfs_dir) {
1145 nt->debugfs_node_dir =
1146 debugfs_create_dir(pci_name(ndev->pdev),
1147 nt_debugfs_dir);
1148 }
1149
1150 for (i = 0; i < qp_count; i++) {
1151 rc = ntb_transport_init_queue(nt, i);
1152 if (rc)
1153 goto err2;
1154 }
1155
1156 INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work);
1157 INIT_WORK(&nt->link_cleanup, ntb_transport_link_cleanup_work);
1158
1159 rc = ntb_set_ctx(ndev, nt, &ntb_transport_ops);
1160 if (rc)
1161 goto err2;
1162
1163 INIT_LIST_HEAD(&nt->client_devs);
1164 rc = ntb_bus_init(nt);
1165 if (rc)
1166 goto err3;
1167
1168 nt->link_is_up = false;
1169 ntb_link_enable(ndev, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
1170 ntb_link_event(ndev);
1171
1172 return 0;
1173
1174 err3:
1175 ntb_clear_ctx(ndev);
1176 err2:
1177 kfree(nt->qp_vec);
1178 err1:
1179 while (i--) {
1180 mw = &nt->mw_vec[i];
1181 iounmap(mw->vbase);
1182 }
1183 kfree(nt->mw_vec);
1184 err:
1185 kfree(nt);
1186 return rc;
1187 }
1188
1189 static void ntb_transport_free(struct ntb_client *self, struct ntb_dev *ndev)
1190 {
1191 struct ntb_transport_ctx *nt = ndev->ctx;
1192 struct ntb_transport_qp *qp;
1193 u64 qp_bitmap_alloc;
1194 int i;
1195
1196 ntb_transport_link_cleanup(nt);
1197 cancel_work_sync(&nt->link_cleanup);
1198 cancel_delayed_work_sync(&nt->link_work);
1199
1200 qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
1201
1202 /* verify that all the qp's are freed */
1203 for (i = 0; i < nt->qp_count; i++) {
1204 qp = &nt->qp_vec[i];
1205 if (qp_bitmap_alloc & BIT_ULL(i))
1206 ntb_transport_free_queue(qp);
1207 debugfs_remove_recursive(qp->debugfs_dir);
1208 }
1209
1210 ntb_link_disable(ndev);
1211 ntb_clear_ctx(ndev);
1212
1213 ntb_bus_remove(nt);
1214
1215 for (i = nt->mw_count; i--; ) {
1216 ntb_free_mw(nt, i);
1217 iounmap(nt->mw_vec[i].vbase);
1218 }
1219
1220 kfree(nt->qp_vec);
1221 kfree(nt->mw_vec);
1222 kfree(nt);
1223 }
1224
1225 static void ntb_complete_rxc(struct ntb_transport_qp *qp)
1226 {
1227 struct ntb_queue_entry *entry;
1228 void *cb_data;
1229 unsigned int len;
1230 unsigned long irqflags;
1231
1232 spin_lock_irqsave(&qp->ntb_rx_q_lock, irqflags);
1233
1234 while (!list_empty(&qp->rx_post_q)) {
1235 entry = list_first_entry(&qp->rx_post_q,
1236 struct ntb_queue_entry, entry);
1237 if (!(entry->flags & DESC_DONE_FLAG))
1238 break;
1239
1240 entry->rx_hdr->flags = 0;
1241 iowrite32(entry->rx_index, &qp->rx_info->entry);
1242
1243 cb_data = entry->cb_data;
1244 len = entry->len;
1245
1246 list_move_tail(&entry->entry, &qp->rx_free_q);
1247
1248 spin_unlock_irqrestore(&qp->ntb_rx_q_lock, irqflags);
1249
1250 if (qp->rx_handler && qp->client_ready)
1251 qp->rx_handler(qp, qp->cb_data, cb_data, len);
1252
1253 spin_lock_irqsave(&qp->ntb_rx_q_lock, irqflags);
1254 }
1255
1256 spin_unlock_irqrestore(&qp->ntb_rx_q_lock, irqflags);
1257 }
1258
1259 static void ntb_rx_copy_callback(void *data,
1260 const struct dmaengine_result *res)
1261 {
1262 struct ntb_queue_entry *entry = data;
1263
1264 /* we need to check DMA results if we are using DMA */
1265 if (res) {
1266 enum dmaengine_tx_result dma_err = res->result;
1267
1268 switch (dma_err) {
1269 case DMA_TRANS_READ_FAILED:
1270 case DMA_TRANS_WRITE_FAILED:
1271 entry->errors++;
1272 case DMA_TRANS_ABORTED:
1273 {
1274 struct ntb_transport_qp *qp = entry->qp;
1275 void *offset = qp->rx_buff + qp->rx_max_frame *
1276 qp->rx_index;
1277
1278 ntb_memcpy_rx(entry, offset);
1279 qp->rx_memcpy++;
1280 return;
1281 }
1282
1283 case DMA_TRANS_NOERROR:
1284 default:
1285 break;
1286 }
1287 }
1288
1289 entry->flags |= DESC_DONE_FLAG;
1290
1291 ntb_complete_rxc(entry->qp);
1292 }
1293
1294 static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void *offset)
1295 {
1296 void *buf = entry->buf;
1297 size_t len = entry->len;
1298
1299 memcpy(buf, offset, len);
1300
1301 /* Ensure that the data is fully copied out before clearing the flag */
1302 wmb();
1303
1304 ntb_rx_copy_callback(entry, NULL);
1305 }
1306
1307 static int ntb_async_rx_submit(struct ntb_queue_entry *entry, void *offset)
1308 {
1309 struct dma_async_tx_descriptor *txd;
1310 struct ntb_transport_qp *qp = entry->qp;
1311 struct dma_chan *chan = qp->rx_dma_chan;
1312 struct dma_device *device;
1313 size_t pay_off, buff_off, len;
1314 struct dmaengine_unmap_data *unmap;
1315 dma_cookie_t cookie;
1316 void *buf = entry->buf;
1317 int retries = 0;
1318
1319 len = entry->len;
1320 device = chan->device;
1321 pay_off = (size_t)offset & ~PAGE_MASK;
1322 buff_off = (size_t)buf & ~PAGE_MASK;
1323
1324 if (!is_dma_copy_aligned(device, pay_off, buff_off, len))
1325 goto err;
1326
1327 unmap = dmaengine_get_unmap_data(device->dev, 2, GFP_NOWAIT);
1328 if (!unmap)
1329 goto err;
1330
1331 unmap->len = len;
1332 unmap->addr[0] = dma_map_page(device->dev, virt_to_page(offset),
1333 pay_off, len, DMA_TO_DEVICE);
1334 if (dma_mapping_error(device->dev, unmap->addr[0]))
1335 goto err_get_unmap;
1336
1337 unmap->to_cnt = 1;
1338
1339 unmap->addr[1] = dma_map_page(device->dev, virt_to_page(buf),
1340 buff_off, len, DMA_FROM_DEVICE);
1341 if (dma_mapping_error(device->dev, unmap->addr[1]))
1342 goto err_get_unmap;
1343
1344 unmap->from_cnt = 1;
1345
1346 for (retries = 0; retries < DMA_RETRIES; retries++) {
1347 txd = device->device_prep_dma_memcpy(chan,
1348 unmap->addr[1],
1349 unmap->addr[0], len,
1350 DMA_PREP_INTERRUPT);
1351 if (txd)
1352 break;
1353
1354 set_current_state(TASK_INTERRUPTIBLE);
1355 schedule_timeout(DMA_OUT_RESOURCE_TO);
1356 }
1357
1358 if (!txd) {
1359 qp->dma_rx_prep_err++;
1360 goto err_get_unmap;
1361 }
1362
1363 txd->callback_result = ntb_rx_copy_callback;
1364 txd->callback_param = entry;
1365 dma_set_unmap(txd, unmap);
1366
1367 cookie = dmaengine_submit(txd);
1368 if (dma_submit_error(cookie))
1369 goto err_set_unmap;
1370
1371 dmaengine_unmap_put(unmap);
1372
1373 qp->last_cookie = cookie;
1374
1375 qp->rx_async++;
1376
1377 return 0;
1378
1379 err_set_unmap:
1380 dmaengine_unmap_put(unmap);
1381 err_get_unmap:
1382 dmaengine_unmap_put(unmap);
1383 err:
1384 return -ENXIO;
1385 }
1386
1387 static void ntb_async_rx(struct ntb_queue_entry *entry, void *offset)
1388 {
1389 struct ntb_transport_qp *qp = entry->qp;
1390 struct dma_chan *chan = qp->rx_dma_chan;
1391 int res;
1392
1393 if (!chan)
1394 goto err;
1395
1396 if (entry->len < copy_bytes)
1397 goto err;
1398
1399 res = ntb_async_rx_submit(entry, offset);
1400 if (res < 0)
1401 goto err;
1402
1403 if (!entry->retries)
1404 qp->rx_async++;
1405
1406 return;
1407
1408 err:
1409 ntb_memcpy_rx(entry, offset);
1410 qp->rx_memcpy++;
1411 }
1412
1413 static int ntb_process_rxc(struct ntb_transport_qp *qp)
1414 {
1415 struct ntb_payload_header *hdr;
1416 struct ntb_queue_entry *entry;
1417 void *offset;
1418
1419 offset = qp->rx_buff + qp->rx_max_frame * qp->rx_index;
1420 hdr = offset + qp->rx_max_frame - sizeof(struct ntb_payload_header);
1421
1422 dev_dbg(&qp->ndev->pdev->dev, "qp %d: RX ver %u len %d flags %x\n",
1423 qp->qp_num, hdr->ver, hdr->len, hdr->flags);
1424
1425 if (!(hdr->flags & DESC_DONE_FLAG)) {
1426 dev_dbg(&qp->ndev->pdev->dev, "done flag not set\n");
1427 qp->rx_ring_empty++;
1428 return -EAGAIN;
1429 }
1430
1431 if (hdr->flags & LINK_DOWN_FLAG) {
1432 dev_dbg(&qp->ndev->pdev->dev, "link down flag set\n");
1433 ntb_qp_link_down(qp);
1434 hdr->flags = 0;
1435 return -EAGAIN;
1436 }
1437
1438 if (hdr->ver != (u32)qp->rx_pkts) {
1439 dev_dbg(&qp->ndev->pdev->dev,
1440 "version mismatch, expected %llu - got %u\n",
1441 qp->rx_pkts, hdr->ver);
1442 qp->rx_err_ver++;
1443 return -EIO;
1444 }
1445
1446 entry = ntb_list_mv(&qp->ntb_rx_q_lock, &qp->rx_pend_q, &qp->rx_post_q);
1447 if (!entry) {
1448 dev_dbg(&qp->ndev->pdev->dev, "no receive buffer\n");
1449 qp->rx_err_no_buf++;
1450 return -EAGAIN;
1451 }
1452
1453 entry->rx_hdr = hdr;
1454 entry->rx_index = qp->rx_index;
1455
1456 if (hdr->len > entry->len) {
1457 dev_dbg(&qp->ndev->pdev->dev,
1458 "receive buffer overflow! Wanted %d got %d\n",
1459 hdr->len, entry->len);
1460 qp->rx_err_oflow++;
1461
1462 entry->len = -EIO;
1463 entry->flags |= DESC_DONE_FLAG;
1464
1465 ntb_complete_rxc(qp);
1466 } else {
1467 dev_dbg(&qp->ndev->pdev->dev,
1468 "RX OK index %u ver %u size %d into buf size %d\n",
1469 qp->rx_index, hdr->ver, hdr->len, entry->len);
1470
1471 qp->rx_bytes += hdr->len;
1472 qp->rx_pkts++;
1473
1474 entry->len = hdr->len;
1475
1476 ntb_async_rx(entry, offset);
1477 }
1478
1479 qp->rx_index++;
1480 qp->rx_index %= qp->rx_max_entry;
1481
1482 return 0;
1483 }
1484
1485 static void ntb_transport_rxc_db(unsigned long data)
1486 {
1487 struct ntb_transport_qp *qp = (void *)data;
1488 int rc, i;
1489
1490 dev_dbg(&qp->ndev->pdev->dev, "%s: doorbell %d received\n",
1491 __func__, qp->qp_num);
1492
1493 /* Limit the number of packets processed in a single interrupt to
1494 * provide fairness to others
1495 */
1496 for (i = 0; i < qp->rx_max_entry; i++) {
1497 rc = ntb_process_rxc(qp);
1498 if (rc)
1499 break;
1500 }
1501
1502 if (i && qp->rx_dma_chan)
1503 dma_async_issue_pending(qp->rx_dma_chan);
1504
1505 if (i == qp->rx_max_entry) {
1506 /* there is more work to do */
1507 if (qp->active)
1508 tasklet_schedule(&qp->rxc_db_work);
1509 } else if (ntb_db_read(qp->ndev) & BIT_ULL(qp->qp_num)) {
1510 /* the doorbell bit is set: clear it */
1511 ntb_db_clear(qp->ndev, BIT_ULL(qp->qp_num));
1512 /* ntb_db_read ensures ntb_db_clear write is committed */
1513 ntb_db_read(qp->ndev);
1514
1515 /* an interrupt may have arrived between finishing
1516 * ntb_process_rxc and clearing the doorbell bit:
1517 * there might be some more work to do.
1518 */
1519 if (qp->active)
1520 tasklet_schedule(&qp->rxc_db_work);
1521 }
1522 }
1523
1524 static void ntb_tx_copy_callback(void *data,
1525 const struct dmaengine_result *res)
1526 {
1527 struct ntb_queue_entry *entry = data;
1528 struct ntb_transport_qp *qp = entry->qp;
1529 struct ntb_payload_header __iomem *hdr = entry->tx_hdr;
1530
1531 /* we need to check DMA results if we are using DMA */
1532 if (res) {
1533 enum dmaengine_tx_result dma_err = res->result;
1534
1535 switch (dma_err) {
1536 case DMA_TRANS_READ_FAILED:
1537 case DMA_TRANS_WRITE_FAILED:
1538 entry->errors++;
1539 case DMA_TRANS_ABORTED:
1540 {
1541 void __iomem *offset =
1542 qp->tx_mw + qp->tx_max_frame *
1543 entry->tx_index;
1544
1545 /* resubmit via CPU */
1546 ntb_memcpy_tx(entry, offset);
1547 qp->tx_memcpy++;
1548 return;
1549 }
1550
1551 case DMA_TRANS_NOERROR:
1552 default:
1553 break;
1554 }
1555 }
1556
1557 iowrite32(entry->flags | DESC_DONE_FLAG, &hdr->flags);
1558
1559 ntb_peer_db_set(qp->ndev, BIT_ULL(qp->qp_num));
1560
1561 /* The entry length can only be zero if the packet is intended to be a
1562 * "link down" or similar. Since no payload is being sent in these
1563 * cases, there is nothing to add to the completion queue.
1564 */
1565 if (entry->len > 0) {
1566 qp->tx_bytes += entry->len;
1567
1568 if (qp->tx_handler)
1569 qp->tx_handler(qp, qp->cb_data, entry->cb_data,
1570 entry->len);
1571 }
1572
1573 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q);
1574 }
1575
1576 static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset)
1577 {
1578 #ifdef ARCH_HAS_NOCACHE_UACCESS
1579 /*
1580 * Using non-temporal mov to improve performance on non-cached
1581 * writes, even though we aren't actually copying from user space.
1582 */
1583 __copy_from_user_inatomic_nocache(offset, entry->buf, entry->len);
1584 #else
1585 memcpy_toio(offset, entry->buf, entry->len);
1586 #endif
1587
1588 /* Ensure that the data is fully copied out before setting the flags */
1589 wmb();
1590
1591 ntb_tx_copy_callback(entry, NULL);
1592 }
1593
1594 static int ntb_async_tx_submit(struct ntb_transport_qp *qp,
1595 struct ntb_queue_entry *entry)
1596 {
1597 struct dma_async_tx_descriptor *txd;
1598 struct dma_chan *chan = qp->tx_dma_chan;
1599 struct dma_device *device;
1600 size_t len = entry->len;
1601 void *buf = entry->buf;
1602 size_t dest_off, buff_off;
1603 struct dmaengine_unmap_data *unmap;
1604 dma_addr_t dest;
1605 dma_cookie_t cookie;
1606 int retries = 0;
1607
1608 device = chan->device;
1609 dest = qp->tx_mw_phys + qp->tx_max_frame * entry->tx_index;
1610 buff_off = (size_t)buf & ~PAGE_MASK;
1611 dest_off = (size_t)dest & ~PAGE_MASK;
1612
1613 if (!is_dma_copy_aligned(device, buff_off, dest_off, len))
1614 goto err;
1615
1616 unmap = dmaengine_get_unmap_data(device->dev, 1, GFP_NOWAIT);
1617 if (!unmap)
1618 goto err;
1619
1620 unmap->len = len;
1621 unmap->addr[0] = dma_map_page(device->dev, virt_to_page(buf),
1622 buff_off, len, DMA_TO_DEVICE);
1623 if (dma_mapping_error(device->dev, unmap->addr[0]))
1624 goto err_get_unmap;
1625
1626 unmap->to_cnt = 1;
1627
1628 for (retries = 0; retries < DMA_RETRIES; retries++) {
1629 txd = device->device_prep_dma_memcpy(chan, dest,
1630 unmap->addr[0], len,
1631 DMA_PREP_INTERRUPT);
1632 if (txd)
1633 break;
1634
1635 set_current_state(TASK_INTERRUPTIBLE);
1636 schedule_timeout(DMA_OUT_RESOURCE_TO);
1637 }
1638
1639 if (!txd) {
1640 qp->dma_tx_prep_err++;
1641 goto err_get_unmap;
1642 }
1643
1644 txd->callback_result = ntb_tx_copy_callback;
1645 txd->callback_param = entry;
1646 dma_set_unmap(txd, unmap);
1647
1648 cookie = dmaengine_submit(txd);
1649 if (dma_submit_error(cookie))
1650 goto err_set_unmap;
1651
1652 dmaengine_unmap_put(unmap);
1653
1654 dma_async_issue_pending(chan);
1655
1656 return 0;
1657 err_set_unmap:
1658 dmaengine_unmap_put(unmap);
1659 err_get_unmap:
1660 dmaengine_unmap_put(unmap);
1661 err:
1662 return -ENXIO;
1663 }
1664
1665 static void ntb_async_tx(struct ntb_transport_qp *qp,
1666 struct ntb_queue_entry *entry)
1667 {
1668 struct ntb_payload_header __iomem *hdr;
1669 struct dma_chan *chan = qp->tx_dma_chan;
1670 void __iomem *offset;
1671 int res;
1672
1673 entry->tx_index = qp->tx_index;
1674 offset = qp->tx_mw + qp->tx_max_frame * entry->tx_index;
1675 hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
1676 entry->tx_hdr = hdr;
1677
1678 iowrite32(entry->len, &hdr->len);
1679 iowrite32((u32)qp->tx_pkts, &hdr->ver);
1680
1681 if (!chan)
1682 goto err;
1683
1684 if (entry->len < copy_bytes)
1685 goto err;
1686
1687 res = ntb_async_tx_submit(qp, entry);
1688 if (res < 0)
1689 goto err;
1690
1691 if (!entry->retries)
1692 qp->tx_async++;
1693
1694 return;
1695
1696 err:
1697 ntb_memcpy_tx(entry, offset);
1698 qp->tx_memcpy++;
1699 }
1700
1701 static int ntb_process_tx(struct ntb_transport_qp *qp,
1702 struct ntb_queue_entry *entry)
1703 {
1704 if (qp->tx_index == qp->remote_rx_info->entry) {
1705 qp->tx_ring_full++;
1706 return -EAGAIN;
1707 }
1708
1709 if (entry->len > qp->tx_max_frame - sizeof(struct ntb_payload_header)) {
1710 if (qp->tx_handler)
1711 qp->tx_handler(qp, qp->cb_data, NULL, -EIO);
1712
1713 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1714 &qp->tx_free_q);
1715 return 0;
1716 }
1717
1718 ntb_async_tx(qp, entry);
1719
1720 qp->tx_index++;
1721 qp->tx_index %= qp->tx_max_entry;
1722
1723 qp->tx_pkts++;
1724
1725 return 0;
1726 }
1727
1728 static void ntb_send_link_down(struct ntb_transport_qp *qp)
1729 {
1730 struct pci_dev *pdev = qp->ndev->pdev;
1731 struct ntb_queue_entry *entry;
1732 int i, rc;
1733
1734 if (!qp->link_is_up)
1735 return;
1736
1737 dev_info(&pdev->dev, "qp %d: Send Link Down\n", qp->qp_num);
1738
1739 for (i = 0; i < NTB_LINK_DOWN_TIMEOUT; i++) {
1740 entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1741 if (entry)
1742 break;
1743 msleep(100);
1744 }
1745
1746 if (!entry)
1747 return;
1748
1749 entry->cb_data = NULL;
1750 entry->buf = NULL;
1751 entry->len = 0;
1752 entry->flags = LINK_DOWN_FLAG;
1753
1754 rc = ntb_process_tx(qp, entry);
1755 if (rc)
1756 dev_err(&pdev->dev, "ntb: QP%d unable to send linkdown msg\n",
1757 qp->qp_num);
1758
1759 ntb_qp_link_down_reset(qp);
1760 }
1761
1762 static bool ntb_dma_filter_fn(struct dma_chan *chan, void *node)
1763 {
1764 return dev_to_node(&chan->dev->device) == (int)(unsigned long)node;
1765 }
1766
1767 /**
1768 * ntb_transport_create_queue - Create a new NTB transport layer queue
1769 * @rx_handler: receive callback function
1770 * @tx_handler: transmit callback function
1771 * @event_handler: event callback function
1772 *
1773 * Create a new NTB transport layer queue and provide the queue with a callback
1774 * routine for both transmit and receive. The receive callback routine will be
1775 * used to pass up data when the transport has received it on the queue. The
1776 * transmit callback routine will be called when the transport has completed the
1777 * transmission of the data on the queue and the data is ready to be freed.
1778 *
1779 * RETURNS: pointer to newly created ntb_queue, NULL on error.
1780 */
1781 struct ntb_transport_qp *
1782 ntb_transport_create_queue(void *data, struct device *client_dev,
1783 const struct ntb_queue_handlers *handlers)
1784 {
1785 struct ntb_dev *ndev;
1786 struct pci_dev *pdev;
1787 struct ntb_transport_ctx *nt;
1788 struct ntb_queue_entry *entry;
1789 struct ntb_transport_qp *qp;
1790 u64 qp_bit;
1791 unsigned int free_queue;
1792 dma_cap_mask_t dma_mask;
1793 int node;
1794 int i;
1795
1796 ndev = dev_ntb(client_dev->parent);
1797 pdev = ndev->pdev;
1798 nt = ndev->ctx;
1799
1800 node = dev_to_node(&ndev->dev);
1801
1802 free_queue = ffs(nt->qp_bitmap);
1803 if (!free_queue)
1804 goto err;
1805
1806 /* decrement free_queue to make it zero based */
1807 free_queue--;
1808
1809 qp = &nt->qp_vec[free_queue];
1810 qp_bit = BIT_ULL(qp->qp_num);
1811
1812 nt->qp_bitmap_free &= ~qp_bit;
1813
1814 qp->cb_data = data;
1815 qp->rx_handler = handlers->rx_handler;
1816 qp->tx_handler = handlers->tx_handler;
1817 qp->event_handler = handlers->event_handler;
1818
1819 dma_cap_zero(dma_mask);
1820 dma_cap_set(DMA_MEMCPY, dma_mask);
1821
1822 if (use_dma) {
1823 qp->tx_dma_chan =
1824 dma_request_channel(dma_mask, ntb_dma_filter_fn,
1825 (void *)(unsigned long)node);
1826 if (!qp->tx_dma_chan)
1827 dev_info(&pdev->dev, "Unable to allocate TX DMA channel\n");
1828
1829 qp->rx_dma_chan =
1830 dma_request_channel(dma_mask, ntb_dma_filter_fn,
1831 (void *)(unsigned long)node);
1832 if (!qp->rx_dma_chan)
1833 dev_info(&pdev->dev, "Unable to allocate RX DMA channel\n");
1834 } else {
1835 qp->tx_dma_chan = NULL;
1836 qp->rx_dma_chan = NULL;
1837 }
1838
1839 dev_dbg(&pdev->dev, "Using %s memcpy for TX\n",
1840 qp->tx_dma_chan ? "DMA" : "CPU");
1841
1842 dev_dbg(&pdev->dev, "Using %s memcpy for RX\n",
1843 qp->rx_dma_chan ? "DMA" : "CPU");
1844
1845 for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
1846 entry = kzalloc_node(sizeof(*entry), GFP_ATOMIC, node);
1847 if (!entry)
1848 goto err1;
1849
1850 entry->qp = qp;
1851 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry,
1852 &qp->rx_free_q);
1853 }
1854 qp->rx_alloc_entry = NTB_QP_DEF_NUM_ENTRIES;
1855
1856 for (i = 0; i < qp->tx_max_entry; i++) {
1857 entry = kzalloc_node(sizeof(*entry), GFP_ATOMIC, node);
1858 if (!entry)
1859 goto err2;
1860
1861 entry->qp = qp;
1862 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1863 &qp->tx_free_q);
1864 }
1865
1866 ntb_db_clear(qp->ndev, qp_bit);
1867 ntb_db_clear_mask(qp->ndev, qp_bit);
1868
1869 dev_info(&pdev->dev, "NTB Transport QP %d created\n", qp->qp_num);
1870
1871 return qp;
1872
1873 err2:
1874 while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1875 kfree(entry);
1876 err1:
1877 qp->rx_alloc_entry = 0;
1878 while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
1879 kfree(entry);
1880 if (qp->tx_dma_chan)
1881 dma_release_channel(qp->tx_dma_chan);
1882 if (qp->rx_dma_chan)
1883 dma_release_channel(qp->rx_dma_chan);
1884 nt->qp_bitmap_free |= qp_bit;
1885 err:
1886 return NULL;
1887 }
1888 EXPORT_SYMBOL_GPL(ntb_transport_create_queue);
1889
1890 /**
1891 * ntb_transport_free_queue - Frees NTB transport queue
1892 * @qp: NTB queue to be freed
1893 *
1894 * Frees NTB transport queue
1895 */
1896 void ntb_transport_free_queue(struct ntb_transport_qp *qp)
1897 {
1898 struct pci_dev *pdev;
1899 struct ntb_queue_entry *entry;
1900 u64 qp_bit;
1901
1902 if (!qp)
1903 return;
1904
1905 pdev = qp->ndev->pdev;
1906
1907 qp->active = false;
1908
1909 if (qp->tx_dma_chan) {
1910 struct dma_chan *chan = qp->tx_dma_chan;
1911 /* Putting the dma_chan to NULL will force any new traffic to be
1912 * processed by the CPU instead of the DAM engine
1913 */
1914 qp->tx_dma_chan = NULL;
1915
1916 /* Try to be nice and wait for any queued DMA engine
1917 * transactions to process before smashing it with a rock
1918 */
1919 dma_sync_wait(chan, qp->last_cookie);
1920 dmaengine_terminate_all(chan);
1921 dma_release_channel(chan);
1922 }
1923
1924 if (qp->rx_dma_chan) {
1925 struct dma_chan *chan = qp->rx_dma_chan;
1926 /* Putting the dma_chan to NULL will force any new traffic to be
1927 * processed by the CPU instead of the DAM engine
1928 */
1929 qp->rx_dma_chan = NULL;
1930
1931 /* Try to be nice and wait for any queued DMA engine
1932 * transactions to process before smashing it with a rock
1933 */
1934 dma_sync_wait(chan, qp->last_cookie);
1935 dmaengine_terminate_all(chan);
1936 dma_release_channel(chan);
1937 }
1938
1939 qp_bit = BIT_ULL(qp->qp_num);
1940
1941 ntb_db_set_mask(qp->ndev, qp_bit);
1942 tasklet_kill(&qp->rxc_db_work);
1943
1944 cancel_delayed_work_sync(&qp->link_work);
1945
1946 qp->cb_data = NULL;
1947 qp->rx_handler = NULL;
1948 qp->tx_handler = NULL;
1949 qp->event_handler = NULL;
1950
1951 while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
1952 kfree(entry);
1953
1954 while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_pend_q))) {
1955 dev_warn(&pdev->dev, "Freeing item from non-empty rx_pend_q\n");
1956 kfree(entry);
1957 }
1958
1959 while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_post_q))) {
1960 dev_warn(&pdev->dev, "Freeing item from non-empty rx_post_q\n");
1961 kfree(entry);
1962 }
1963
1964 while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1965 kfree(entry);
1966
1967 qp->transport->qp_bitmap_free |= qp_bit;
1968
1969 dev_info(&pdev->dev, "NTB Transport QP %d freed\n", qp->qp_num);
1970 }
1971 EXPORT_SYMBOL_GPL(ntb_transport_free_queue);
1972
1973 /**
1974 * ntb_transport_rx_remove - Dequeues enqueued rx packet
1975 * @qp: NTB queue to be freed
1976 * @len: pointer to variable to write enqueued buffers length
1977 *
1978 * Dequeues unused buffers from receive queue. Should only be used during
1979 * shutdown of qp.
1980 *
1981 * RETURNS: NULL error value on error, or void* for success.
1982 */
1983 void *ntb_transport_rx_remove(struct ntb_transport_qp *qp, unsigned int *len)
1984 {
1985 struct ntb_queue_entry *entry;
1986 void *buf;
1987
1988 if (!qp || qp->client_ready)
1989 return NULL;
1990
1991 entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_pend_q);
1992 if (!entry)
1993 return NULL;
1994
1995 buf = entry->cb_data;
1996 *len = entry->len;
1997
1998 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_free_q);
1999
2000 return buf;
2001 }
2002 EXPORT_SYMBOL_GPL(ntb_transport_rx_remove);
2003
2004 /**
2005 * ntb_transport_rx_enqueue - Enqueue a new NTB queue entry
2006 * @qp: NTB transport layer queue the entry is to be enqueued on
2007 * @cb: per buffer pointer for callback function to use
2008 * @data: pointer to data buffer that incoming packets will be copied into
2009 * @len: length of the data buffer
2010 *
2011 * Enqueue a new receive buffer onto the transport queue into which a NTB
2012 * payload can be received into.
2013 *
2014 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
2015 */
2016 int ntb_transport_rx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
2017 unsigned int len)
2018 {
2019 struct ntb_queue_entry *entry;
2020
2021 if (!qp)
2022 return -EINVAL;
2023
2024 entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q);
2025 if (!entry)
2026 return -ENOMEM;
2027
2028 entry->cb_data = cb;
2029 entry->buf = data;
2030 entry->len = len;
2031 entry->flags = 0;
2032 entry->retries = 0;
2033 entry->errors = 0;
2034 entry->rx_index = 0;
2035
2036 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_pend_q);
2037
2038 if (qp->active)
2039 tasklet_schedule(&qp->rxc_db_work);
2040
2041 return 0;
2042 }
2043 EXPORT_SYMBOL_GPL(ntb_transport_rx_enqueue);
2044
2045 /**
2046 * ntb_transport_tx_enqueue - Enqueue a new NTB queue entry
2047 * @qp: NTB transport layer queue the entry is to be enqueued on
2048 * @cb: per buffer pointer for callback function to use
2049 * @data: pointer to data buffer that will be sent
2050 * @len: length of the data buffer
2051 *
2052 * Enqueue a new transmit buffer onto the transport queue from which a NTB
2053 * payload will be transmitted. This assumes that a lock is being held to
2054 * serialize access to the qp.
2055 *
2056 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
2057 */
2058 int ntb_transport_tx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
2059 unsigned int len)
2060 {
2061 struct ntb_queue_entry *entry;
2062 int rc;
2063
2064 if (!qp || !qp->link_is_up || !len)
2065 return -EINVAL;
2066
2067 entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
2068 if (!entry) {
2069 qp->tx_err_no_buf++;
2070 return -EBUSY;
2071 }
2072
2073 entry->cb_data = cb;
2074 entry->buf = data;
2075 entry->len = len;
2076 entry->flags = 0;
2077 entry->errors = 0;
2078 entry->retries = 0;
2079 entry->tx_index = 0;
2080
2081 rc = ntb_process_tx(qp, entry);
2082 if (rc)
2083 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
2084 &qp->tx_free_q);
2085
2086 return rc;
2087 }
2088 EXPORT_SYMBOL_GPL(ntb_transport_tx_enqueue);
2089
2090 /**
2091 * ntb_transport_link_up - Notify NTB transport of client readiness to use queue
2092 * @qp: NTB transport layer queue to be enabled
2093 *
2094 * Notify NTB transport layer of client readiness to use queue
2095 */
2096 void ntb_transport_link_up(struct ntb_transport_qp *qp)
2097 {
2098 if (!qp)
2099 return;
2100
2101 qp->client_ready = true;
2102
2103 if (qp->transport->link_is_up)
2104 schedule_delayed_work(&qp->link_work, 0);
2105 }
2106 EXPORT_SYMBOL_GPL(ntb_transport_link_up);
2107
2108 /**
2109 * ntb_transport_link_down - Notify NTB transport to no longer enqueue data
2110 * @qp: NTB transport layer queue to be disabled
2111 *
2112 * Notify NTB transport layer of client's desire to no longer receive data on
2113 * transport queue specified. It is the client's responsibility to ensure all
2114 * entries on queue are purged or otherwise handled appropriately.
2115 */
2116 void ntb_transport_link_down(struct ntb_transport_qp *qp)
2117 {
2118 int val;
2119
2120 if (!qp)
2121 return;
2122
2123 qp->client_ready = false;
2124
2125 val = ntb_spad_read(qp->ndev, QP_LINKS);
2126
2127 ntb_peer_spad_write(qp->ndev, QP_LINKS,
2128 val & ~BIT(qp->qp_num));
2129
2130 if (qp->link_is_up)
2131 ntb_send_link_down(qp);
2132 else
2133 cancel_delayed_work_sync(&qp->link_work);
2134 }
2135 EXPORT_SYMBOL_GPL(ntb_transport_link_down);
2136
2137 /**
2138 * ntb_transport_link_query - Query transport link state
2139 * @qp: NTB transport layer queue to be queried
2140 *
2141 * Query connectivity to the remote system of the NTB transport queue
2142 *
2143 * RETURNS: true for link up or false for link down
2144 */
2145 bool ntb_transport_link_query(struct ntb_transport_qp *qp)
2146 {
2147 if (!qp)
2148 return false;
2149
2150 return qp->link_is_up;
2151 }
2152 EXPORT_SYMBOL_GPL(ntb_transport_link_query);
2153
2154 /**
2155 * ntb_transport_qp_num - Query the qp number
2156 * @qp: NTB transport layer queue to be queried
2157 *
2158 * Query qp number of the NTB transport queue
2159 *
2160 * RETURNS: a zero based number specifying the qp number
2161 */
2162 unsigned char ntb_transport_qp_num(struct ntb_transport_qp *qp)
2163 {
2164 if (!qp)
2165 return 0;
2166
2167 return qp->qp_num;
2168 }
2169 EXPORT_SYMBOL_GPL(ntb_transport_qp_num);
2170
2171 /**
2172 * ntb_transport_max_size - Query the max payload size of a qp
2173 * @qp: NTB transport layer queue to be queried
2174 *
2175 * Query the maximum payload size permissible on the given qp
2176 *
2177 * RETURNS: the max payload size of a qp
2178 */
2179 unsigned int ntb_transport_max_size(struct ntb_transport_qp *qp)
2180 {
2181 unsigned int max_size;
2182 unsigned int copy_align;
2183 struct dma_chan *rx_chan, *tx_chan;
2184
2185 if (!qp)
2186 return 0;
2187
2188 rx_chan = qp->rx_dma_chan;
2189 tx_chan = qp->tx_dma_chan;
2190
2191 copy_align = max(rx_chan ? rx_chan->device->copy_align : 0,
2192 tx_chan ? tx_chan->device->copy_align : 0);
2193
2194 /* If DMA engine usage is possible, try to find the max size for that */
2195 max_size = qp->tx_max_frame - sizeof(struct ntb_payload_header);
2196 max_size = round_down(max_size, 1 << copy_align);
2197
2198 return max_size;
2199 }
2200 EXPORT_SYMBOL_GPL(ntb_transport_max_size);
2201
2202 unsigned int ntb_transport_tx_free_entry(struct ntb_transport_qp *qp)
2203 {
2204 unsigned int head = qp->tx_index;
2205 unsigned int tail = qp->remote_rx_info->entry;
2206
2207 return tail > head ? tail - head : qp->tx_max_entry + tail - head;
2208 }
2209 EXPORT_SYMBOL_GPL(ntb_transport_tx_free_entry);
2210
2211 static void ntb_transport_doorbell_callback(void *data, int vector)
2212 {
2213 struct ntb_transport_ctx *nt = data;
2214 struct ntb_transport_qp *qp;
2215 u64 db_bits;
2216 unsigned int qp_num;
2217
2218 db_bits = (nt->qp_bitmap & ~nt->qp_bitmap_free &
2219 ntb_db_vector_mask(nt->ndev, vector));
2220
2221 while (db_bits) {
2222 qp_num = __ffs(db_bits);
2223 qp = &nt->qp_vec[qp_num];
2224
2225 if (qp->active)
2226 tasklet_schedule(&qp->rxc_db_work);
2227
2228 db_bits &= ~BIT_ULL(qp_num);
2229 }
2230 }
2231
2232 static const struct ntb_ctx_ops ntb_transport_ops = {
2233 .link_event = ntb_transport_event_callback,
2234 .db_event = ntb_transport_doorbell_callback,
2235 };
2236
2237 static struct ntb_client ntb_transport_client = {
2238 .ops = {
2239 .probe = ntb_transport_probe,
2240 .remove = ntb_transport_free,
2241 },
2242 };
2243
2244 static int __init ntb_transport_init(void)
2245 {
2246 int rc;
2247
2248 pr_info("%s, version %s\n", NTB_TRANSPORT_DESC, NTB_TRANSPORT_VER);
2249
2250 if (debugfs_initialized())
2251 nt_debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
2252
2253 rc = bus_register(&ntb_transport_bus);
2254 if (rc)
2255 goto err_bus;
2256
2257 rc = ntb_register_client(&ntb_transport_client);
2258 if (rc)
2259 goto err_client;
2260
2261 return 0;
2262
2263 err_client:
2264 bus_unregister(&ntb_transport_bus);
2265 err_bus:
2266 debugfs_remove_recursive(nt_debugfs_dir);
2267 return rc;
2268 }
2269 module_init(ntb_transport_init);
2270
2271 static void __exit ntb_transport_exit(void)
2272 {
2273 debugfs_remove_recursive(nt_debugfs_dir);
2274
2275 ntb_unregister_client(&ntb_transport_client);
2276 bus_unregister(&ntb_transport_bus);
2277 }
2278 module_exit(ntb_transport_exit);
Linux kernel - Deliverables
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