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Linux 4.19.133
[linux/fpc-iii.git] / drivers / ntb / ntb_transport.c
blob9398959664769b5f6cd3c79e4914199d1cf35f0d
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 #define NTB_TRANSPORT_MIN_SPADS (MW0_SZ_HIGH + 2)
70
71 MODULE_DESCRIPTION(NTB_TRANSPORT_DESC);
72 MODULE_VERSION(NTB_TRANSPORT_VER);
73 MODULE_LICENSE("Dual BSD/GPL");
74 MODULE_AUTHOR("Intel Corporation");
75
76 static unsigned long max_mw_size;
77 module_param(max_mw_size, ulong, 0644);
78 MODULE_PARM_DESC(max_mw_size, "Limit size of large memory windows");
79
80 static unsigned int transport_mtu = 0x10000;
81 module_param(transport_mtu, uint, 0644);
82 MODULE_PARM_DESC(transport_mtu, "Maximum size of NTB transport packets");
83
84 static unsigned char max_num_clients;
85 module_param(max_num_clients, byte, 0644);
86 MODULE_PARM_DESC(max_num_clients, "Maximum number of NTB transport clients");
87
88 static unsigned int copy_bytes = 1024;
89 module_param(copy_bytes, uint, 0644);
90 MODULE_PARM_DESC(copy_bytes, "Threshold under which NTB will use the CPU to copy instead of DMA");
91
92 static bool use_dma;
93 module_param(use_dma, bool, 0644);
94 MODULE_PARM_DESC(use_dma, "Use DMA engine to perform large data copy");
95
96 static struct dentry *nt_debugfs_dir;
97
98 /* Only two-ports NTB devices are supported */
99 #define PIDX NTB_DEF_PEER_IDX
100
101 struct ntb_queue_entry {
102 /* ntb_queue list reference */
103 struct list_head entry;
104 /* pointers to data to be transferred */
105 void *cb_data;
106 void *buf;
107 unsigned int len;
108 unsigned int flags;
109 int retries;
110 int errors;
111 unsigned int tx_index;
112 unsigned int rx_index;
113
114 struct ntb_transport_qp *qp;
115 union {
116 struct ntb_payload_header __iomem *tx_hdr;
117 struct ntb_payload_header *rx_hdr;
118 };
119 };
120
121 struct ntb_rx_info {
122 unsigned int entry;
123 };
124
125 struct ntb_transport_qp {
126 struct ntb_transport_ctx *transport;
127 struct ntb_dev *ndev;
128 void *cb_data;
129 struct dma_chan *tx_dma_chan;
130 struct dma_chan *rx_dma_chan;
131
132 bool client_ready;
133 bool link_is_up;
134 bool active;
135
136 u8 qp_num; /* Only 64 QP's are allowed. 0-63 */
137 u64 qp_bit;
138
139 struct ntb_rx_info __iomem *rx_info;
140 struct ntb_rx_info *remote_rx_info;
141
142 void (*tx_handler)(struct ntb_transport_qp *qp, void *qp_data,
143 void *data, int len);
144 struct list_head tx_free_q;
145 spinlock_t ntb_tx_free_q_lock;
146 void __iomem *tx_mw;
147 dma_addr_t tx_mw_phys;
148 unsigned int tx_index;
149 unsigned int tx_max_entry;
150 unsigned int tx_max_frame;
151
152 void (*rx_handler)(struct ntb_transport_qp *qp, void *qp_data,
153 void *data, int len);
154 struct list_head rx_post_q;
155 struct list_head rx_pend_q;
156 struct list_head rx_free_q;
157 /* ntb_rx_q_lock: synchronize access to rx_XXXX_q */
158 spinlock_t ntb_rx_q_lock;
159 void *rx_buff;
160 unsigned int rx_index;
161 unsigned int rx_max_entry;
162 unsigned int rx_max_frame;
163 unsigned int rx_alloc_entry;
164 dma_cookie_t last_cookie;
165 struct tasklet_struct rxc_db_work;
166
167 void (*event_handler)(void *data, int status);
168 struct delayed_work link_work;
169 struct work_struct link_cleanup;
170
171 struct dentry *debugfs_dir;
172 struct dentry *debugfs_stats;
173
174 /* Stats */
175 u64 rx_bytes;
176 u64 rx_pkts;
177 u64 rx_ring_empty;
178 u64 rx_err_no_buf;
179 u64 rx_err_oflow;
180 u64 rx_err_ver;
181 u64 rx_memcpy;
182 u64 rx_async;
183 u64 tx_bytes;
184 u64 tx_pkts;
185 u64 tx_ring_full;
186 u64 tx_err_no_buf;
187 u64 tx_memcpy;
188 u64 tx_async;
189 };
190
191 struct ntb_transport_mw {
192 phys_addr_t phys_addr;
193 resource_size_t phys_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 };
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
257 static void ntb_transport_rxc_db(unsigned long data);
258 static const struct ntb_ctx_ops ntb_transport_ops;
259 static struct ntb_client ntb_transport_client;
260 static int ntb_async_tx_submit(struct ntb_transport_qp *qp,
261 struct ntb_queue_entry *entry);
262 static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset);
263 static int ntb_async_rx_submit(struct ntb_queue_entry *entry, void *offset);
264 static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void *offset);
265
266
267 static int ntb_transport_bus_match(struct device *dev,
268 struct device_driver *drv)
269 {
270 return !strncmp(dev_name(dev), drv->name, strlen(drv->name));
271 }
272
273 static int ntb_transport_bus_probe(struct device *dev)
274 {
275 const struct ntb_transport_client *client;
276 int rc = -EINVAL;
277
278 get_device(dev);
279
280 client = drv_client(dev->driver);
281 rc = client->probe(dev);
282 if (rc)
283 put_device(dev);
284
285 return rc;
286 }
287
288 static int ntb_transport_bus_remove(struct device *dev)
289 {
290 const struct ntb_transport_client *client;
291
292 client = drv_client(dev->driver);
293 client->remove(dev);
294
295 put_device(dev);
296
297 return 0;
298 }
299
300 static struct bus_type ntb_transport_bus = {
301 .name = "ntb_transport",
302 .match = ntb_transport_bus_match,
303 .probe = ntb_transport_bus_probe,
304 .remove = ntb_transport_bus_remove,
305 };
306
307 static LIST_HEAD(ntb_transport_list);
308
309 static int ntb_bus_init(struct ntb_transport_ctx *nt)
310 {
311 list_add_tail(&nt->entry, &ntb_transport_list);
312 return 0;
313 }
314
315 static void ntb_bus_remove(struct ntb_transport_ctx *nt)
316 {
317 struct ntb_transport_client_dev *client_dev, *cd;
318
319 list_for_each_entry_safe(client_dev, cd, &nt->client_devs, entry) {
320 dev_err(client_dev->dev.parent, "%s still attached to bus, removing\n",
321 dev_name(&client_dev->dev));
322 list_del(&client_dev->entry);
323 device_unregister(&client_dev->dev);
324 }
325
326 list_del(&nt->entry);
327 }
328
329 static void ntb_transport_client_release(struct device *dev)
330 {
331 struct ntb_transport_client_dev *client_dev;
332
333 client_dev = dev_client_dev(dev);
334 kfree(client_dev);
335 }
336
337 /**
338 * ntb_transport_unregister_client_dev - Unregister NTB client device
339 * @device_name: Name of NTB client device
340 *
341 * Unregister an NTB client device with the NTB transport layer
342 */
343 void ntb_transport_unregister_client_dev(char *device_name)
344 {
345 struct ntb_transport_client_dev *client, *cd;
346 struct ntb_transport_ctx *nt;
347
348 list_for_each_entry(nt, &ntb_transport_list, entry)
349 list_for_each_entry_safe(client, cd, &nt->client_devs, entry)
350 if (!strncmp(dev_name(&client->dev), device_name,
351 strlen(device_name))) {
352 list_del(&client->entry);
353 device_unregister(&client->dev);
354 }
355 }
356 EXPORT_SYMBOL_GPL(ntb_transport_unregister_client_dev);
357
358 /**
359 * ntb_transport_register_client_dev - Register NTB client device
360 * @device_name: Name of NTB client device
361 *
362 * Register an NTB client device with the NTB transport layer
363 */
364 int ntb_transport_register_client_dev(char *device_name)
365 {
366 struct ntb_transport_client_dev *client_dev;
367 struct ntb_transport_ctx *nt;
368 int node;
369 int rc, i = 0;
370
371 if (list_empty(&ntb_transport_list))
372 return -ENODEV;
373
374 list_for_each_entry(nt, &ntb_transport_list, entry) {
375 struct device *dev;
376
377 node = dev_to_node(&nt->ndev->dev);
378
379 client_dev = kzalloc_node(sizeof(*client_dev),
380 GFP_KERNEL, node);
381 if (!client_dev) {
382 rc = -ENOMEM;
383 goto err;
384 }
385
386 dev = &client_dev->dev;
387
388 /* setup and register client devices */
389 dev_set_name(dev, "%s%d", device_name, i);
390 dev->bus = &ntb_transport_bus;
391 dev->release = ntb_transport_client_release;
392 dev->parent = &nt->ndev->dev;
393
394 rc = device_register(dev);
395 if (rc) {
396 kfree(client_dev);
397 goto err;
398 }
399
400 list_add_tail(&client_dev->entry, &nt->client_devs);
401 i++;
402 }
403
404 return 0;
405
406 err:
407 ntb_transport_unregister_client_dev(device_name);
408
409 return rc;
410 }
411 EXPORT_SYMBOL_GPL(ntb_transport_register_client_dev);
412
413 /**
414 * ntb_transport_register_client - Register NTB client driver
415 * @drv: NTB client driver to be registered
416 *
417 * Register an NTB client driver with the NTB transport layer
418 *
419 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
420 */
421 int ntb_transport_register_client(struct ntb_transport_client *drv)
422 {
423 drv->driver.bus = &ntb_transport_bus;
424
425 if (list_empty(&ntb_transport_list))
426 return -ENODEV;
427
428 return driver_register(&drv->driver);
429 }
430 EXPORT_SYMBOL_GPL(ntb_transport_register_client);
431
432 /**
433 * ntb_transport_unregister_client - Unregister NTB client driver
434 * @drv: NTB client driver to be unregistered
435 *
436 * Unregister an NTB client driver with the NTB transport layer
437 *
438 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
439 */
440 void ntb_transport_unregister_client(struct ntb_transport_client *drv)
441 {
442 driver_unregister(&drv->driver);
443 }
444 EXPORT_SYMBOL_GPL(ntb_transport_unregister_client);
445
446 static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count,
447 loff_t *offp)
448 {
449 struct ntb_transport_qp *qp;
450 char *buf;
451 ssize_t ret, out_offset, out_count;
452
453 qp = filp->private_data;
454
455 if (!qp || !qp->link_is_up)
456 return 0;
457
458 out_count = 1000;
459
460 buf = kmalloc(out_count, GFP_KERNEL);
461 if (!buf)
462 return -ENOMEM;
463
464 out_offset = 0;
465 out_offset += snprintf(buf + out_offset, out_count - out_offset,
466 "\nNTB QP stats:\n\n");
467 out_offset += snprintf(buf + out_offset, out_count - out_offset,
468 "rx_bytes - \t%llu\n", qp->rx_bytes);
469 out_offset += snprintf(buf + out_offset, out_count - out_offset,
470 "rx_pkts - \t%llu\n", qp->rx_pkts);
471 out_offset += snprintf(buf + out_offset, out_count - out_offset,
472 "rx_memcpy - \t%llu\n", qp->rx_memcpy);
473 out_offset += snprintf(buf + out_offset, out_count - out_offset,
474 "rx_async - \t%llu\n", qp->rx_async);
475 out_offset += snprintf(buf + out_offset, out_count - out_offset,
476 "rx_ring_empty - %llu\n", qp->rx_ring_empty);
477 out_offset += snprintf(buf + out_offset, out_count - out_offset,
478 "rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
479 out_offset += snprintf(buf + out_offset, out_count - out_offset,
480 "rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
481 out_offset += snprintf(buf + out_offset, out_count - out_offset,
482 "rx_err_ver - \t%llu\n", qp->rx_err_ver);
483 out_offset += snprintf(buf + out_offset, out_count - out_offset,
484 "rx_buff - \t0x%p\n", qp->rx_buff);
485 out_offset += snprintf(buf + out_offset, out_count - out_offset,
486 "rx_index - \t%u\n", qp->rx_index);
487 out_offset += snprintf(buf + out_offset, out_count - out_offset,
488 "rx_max_entry - \t%u\n", qp->rx_max_entry);
489 out_offset += snprintf(buf + out_offset, out_count - out_offset,
490 "rx_alloc_entry - \t%u\n\n", qp->rx_alloc_entry);
491
492 out_offset += snprintf(buf + out_offset, out_count - out_offset,
493 "tx_bytes - \t%llu\n", qp->tx_bytes);
494 out_offset += snprintf(buf + out_offset, out_count - out_offset,
495 "tx_pkts - \t%llu\n", qp->tx_pkts);
496 out_offset += snprintf(buf + out_offset, out_count - out_offset,
497 "tx_memcpy - \t%llu\n", qp->tx_memcpy);
498 out_offset += snprintf(buf + out_offset, out_count - out_offset,
499 "tx_async - \t%llu\n", qp->tx_async);
500 out_offset += snprintf(buf + out_offset, out_count - out_offset,
501 "tx_ring_full - \t%llu\n", qp->tx_ring_full);
502 out_offset += snprintf(buf + out_offset, out_count - out_offset,
503 "tx_err_no_buf - %llu\n", qp->tx_err_no_buf);
504 out_offset += snprintf(buf + out_offset, out_count - out_offset,
505 "tx_mw - \t0x%p\n", qp->tx_mw);
506 out_offset += snprintf(buf + out_offset, out_count - out_offset,
507 "tx_index (H) - \t%u\n", qp->tx_index);
508 out_offset += snprintf(buf + out_offset, out_count - out_offset,
509 "RRI (T) - \t%u\n",
510 qp->remote_rx_info->entry);
511 out_offset += snprintf(buf + out_offset, out_count - out_offset,
512 "tx_max_entry - \t%u\n", qp->tx_max_entry);
513 out_offset += snprintf(buf + out_offset, out_count - out_offset,
514 "free tx - \t%u\n",
515 ntb_transport_tx_free_entry(qp));
516
517 out_offset += snprintf(buf + out_offset, out_count - out_offset,
518 "\n");
519 out_offset += snprintf(buf + out_offset, out_count - out_offset,
520 "Using TX DMA - \t%s\n",
521 qp->tx_dma_chan ? "Yes" : "No");
522 out_offset += snprintf(buf + out_offset, out_count - out_offset,
523 "Using RX DMA - \t%s\n",
524 qp->rx_dma_chan ? "Yes" : "No");
525 out_offset += snprintf(buf + out_offset, out_count - out_offset,
526 "QP Link - \t%s\n",
527 qp->link_is_up ? "Up" : "Down");
528 out_offset += snprintf(buf + out_offset, out_count - out_offset,
529 "\n");
530
531 if (out_offset > out_count)
532 out_offset = out_count;
533
534 ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
535 kfree(buf);
536 return ret;
537 }
538
539 static const struct file_operations ntb_qp_debugfs_stats = {
540 .owner = THIS_MODULE,
541 .open = simple_open,
542 .read = debugfs_read,
543 };
544
545 static void ntb_list_add(spinlock_t *lock, struct list_head *entry,
546 struct list_head *list)
547 {
548 unsigned long flags;
549
550 spin_lock_irqsave(lock, flags);
551 list_add_tail(entry, list);
552 spin_unlock_irqrestore(lock, flags);
553 }
554
555 static struct ntb_queue_entry *ntb_list_rm(spinlock_t *lock,
556 struct list_head *list)
557 {
558 struct ntb_queue_entry *entry;
559 unsigned long flags;
560
561 spin_lock_irqsave(lock, flags);
562 if (list_empty(list)) {
563 entry = NULL;
564 goto out;
565 }
566 entry = list_first_entry(list, struct ntb_queue_entry, entry);
567 list_del(&entry->entry);
568
569 out:
570 spin_unlock_irqrestore(lock, flags);
571
572 return entry;
573 }
574
575 static struct ntb_queue_entry *ntb_list_mv(spinlock_t *lock,
576 struct list_head *list,
577 struct list_head *to_list)
578 {
579 struct ntb_queue_entry *entry;
580 unsigned long flags;
581
582 spin_lock_irqsave(lock, flags);
583
584 if (list_empty(list)) {
585 entry = NULL;
586 } else {
587 entry = list_first_entry(list, struct ntb_queue_entry, entry);
588 list_move_tail(&entry->entry, to_list);
589 }
590
591 spin_unlock_irqrestore(lock, flags);
592
593 return entry;
594 }
595
596 static int ntb_transport_setup_qp_mw(struct ntb_transport_ctx *nt,
597 unsigned int qp_num)
598 {
599 struct ntb_transport_qp *qp = &nt->qp_vec[qp_num];
600 struct ntb_transport_mw *mw;
601 struct ntb_dev *ndev = nt->ndev;
602 struct ntb_queue_entry *entry;
603 unsigned int rx_size, num_qps_mw;
604 unsigned int mw_num, mw_count, qp_count;
605 unsigned int i;
606 int node;
607
608 mw_count = nt->mw_count;
609 qp_count = nt->qp_count;
610
611 mw_num = QP_TO_MW(nt, qp_num);
612 mw = &nt->mw_vec[mw_num];
613
614 if (!mw->virt_addr)
615 return -ENOMEM;
616
617 if (mw_num < qp_count % mw_count)
618 num_qps_mw = qp_count / mw_count + 1;
619 else
620 num_qps_mw = qp_count / mw_count;
621
622 rx_size = (unsigned int)mw->xlat_size / num_qps_mw;
623 qp->rx_buff = mw->virt_addr + rx_size * (qp_num / mw_count);
624 rx_size -= sizeof(struct ntb_rx_info);
625
626 qp->remote_rx_info = qp->rx_buff + rx_size;
627
628 /* Due to housekeeping, there must be atleast 2 buffs */
629 qp->rx_max_frame = min(transport_mtu, rx_size / 2);
630 qp->rx_max_entry = rx_size / qp->rx_max_frame;
631 qp->rx_index = 0;
632
633 /*
634 * Checking to see if we have more entries than the default.
635 * We should add additional entries if that is the case so we
636 * can be in sync with the transport frames.
637 */
638 node = dev_to_node(&ndev->dev);
639 for (i = qp->rx_alloc_entry; i < qp->rx_max_entry; i++) {
640 entry = kzalloc_node(sizeof(*entry), GFP_KERNEL, node);
641 if (!entry)
642 return -ENOMEM;
643
644 entry->qp = qp;
645 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry,
646 &qp->rx_free_q);
647 qp->rx_alloc_entry++;
648 }
649
650 qp->remote_rx_info->entry = qp->rx_max_entry - 1;
651
652 /* setup the hdr offsets with 0's */
653 for (i = 0; i < qp->rx_max_entry; i++) {
654 void *offset = (qp->rx_buff + qp->rx_max_frame * (i + 1) -
655 sizeof(struct ntb_payload_header));
656 memset(offset, 0, sizeof(struct ntb_payload_header));
657 }
658
659 qp->rx_pkts = 0;
660 qp->tx_pkts = 0;
661 qp->tx_index = 0;
662
663 return 0;
664 }
665
666 static void ntb_free_mw(struct ntb_transport_ctx *nt, int num_mw)
667 {
668 struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
669 struct pci_dev *pdev = nt->ndev->pdev;
670
671 if (!mw->virt_addr)
672 return;
673
674 ntb_mw_clear_trans(nt->ndev, PIDX, num_mw);
675 dma_free_coherent(&pdev->dev, mw->buff_size,
676 mw->virt_addr, mw->dma_addr);
677 mw->xlat_size = 0;
678 mw->buff_size = 0;
679 mw->virt_addr = NULL;
680 }
681
682 static int ntb_set_mw(struct ntb_transport_ctx *nt, int num_mw,
683 resource_size_t size)
684 {
685 struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
686 struct pci_dev *pdev = nt->ndev->pdev;
687 size_t xlat_size, buff_size;
688 resource_size_t xlat_align;
689 resource_size_t xlat_align_size;
690 int rc;
691
692 if (!size)
693 return -EINVAL;
694
695 rc = ntb_mw_get_align(nt->ndev, PIDX, num_mw, &xlat_align,
696 &xlat_align_size, NULL);
697 if (rc)
698 return rc;
699
700 xlat_size = round_up(size, xlat_align_size);
701 buff_size = round_up(size, xlat_align);
702
703 /* No need to re-setup */
704 if (mw->xlat_size == xlat_size)
705 return 0;
706
707 if (mw->buff_size)
708 ntb_free_mw(nt, num_mw);
709
710 /* Alloc memory for receiving data. Must be aligned */
711 mw->xlat_size = xlat_size;
712 mw->buff_size = buff_size;
713
714 mw->virt_addr = dma_alloc_coherent(&pdev->dev, buff_size,
715 &mw->dma_addr, GFP_KERNEL);
716 if (!mw->virt_addr) {
717 mw->xlat_size = 0;
718 mw->buff_size = 0;
719 dev_err(&pdev->dev, "Unable to alloc MW buff of size %zu\n",
720 buff_size);
721 return -ENOMEM;
722 }
723
724 /*
725 * we must ensure that the memory address allocated is BAR size
726 * aligned in order for the XLAT register to take the value. This
727 * is a requirement of the hardware. It is recommended to setup CMA
728 * for BAR sizes equal or greater than 4MB.
729 */
730 if (!IS_ALIGNED(mw->dma_addr, xlat_align)) {
731 dev_err(&pdev->dev, "DMA memory %pad is not aligned\n",
732 &mw->dma_addr);
733 ntb_free_mw(nt, num_mw);
734 return -ENOMEM;
735 }
736
737 /* Notify HW the memory location of the receive buffer */
738 rc = ntb_mw_set_trans(nt->ndev, PIDX, num_mw, mw->dma_addr,
739 mw->xlat_size);
740 if (rc) {
741 dev_err(&pdev->dev, "Unable to set mw%d translation", num_mw);
742 ntb_free_mw(nt, num_mw);
743 return -EIO;
744 }
745
746 return 0;
747 }
748
749 static void ntb_qp_link_down_reset(struct ntb_transport_qp *qp)
750 {
751 qp->link_is_up = false;
752 qp->active = false;
753
754 qp->tx_index = 0;
755 qp->rx_index = 0;
756 qp->rx_bytes = 0;
757 qp->rx_pkts = 0;
758 qp->rx_ring_empty = 0;
759 qp->rx_err_no_buf = 0;
760 qp->rx_err_oflow = 0;
761 qp->rx_err_ver = 0;
762 qp->rx_memcpy = 0;
763 qp->rx_async = 0;
764 qp->tx_bytes = 0;
765 qp->tx_pkts = 0;
766 qp->tx_ring_full = 0;
767 qp->tx_err_no_buf = 0;
768 qp->tx_memcpy = 0;
769 qp->tx_async = 0;
770 }
771
772 static void ntb_qp_link_cleanup(struct ntb_transport_qp *qp)
773 {
774 struct ntb_transport_ctx *nt = qp->transport;
775 struct pci_dev *pdev = nt->ndev->pdev;
776
777 dev_info(&pdev->dev, "qp %d: Link Cleanup\n", qp->qp_num);
778
779 cancel_delayed_work_sync(&qp->link_work);
780 ntb_qp_link_down_reset(qp);
781
782 if (qp->event_handler)
783 qp->event_handler(qp->cb_data, qp->link_is_up);
784 }
785
786 static void ntb_qp_link_cleanup_work(struct work_struct *work)
787 {
788 struct ntb_transport_qp *qp = container_of(work,
789 struct ntb_transport_qp,
790 link_cleanup);
791 struct ntb_transport_ctx *nt = qp->transport;
792
793 ntb_qp_link_cleanup(qp);
794
795 if (nt->link_is_up)
796 schedule_delayed_work(&qp->link_work,
797 msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
798 }
799
800 static void ntb_qp_link_down(struct ntb_transport_qp *qp)
801 {
802 schedule_work(&qp->link_cleanup);
803 }
804
805 static void ntb_transport_link_cleanup(struct ntb_transport_ctx *nt)
806 {
807 struct ntb_transport_qp *qp;
808 u64 qp_bitmap_alloc;
809 unsigned int i, count;
810
811 qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
812
813 /* Pass along the info to any clients */
814 for (i = 0; i < nt->qp_count; i++)
815 if (qp_bitmap_alloc & BIT_ULL(i)) {
816 qp = &nt->qp_vec[i];
817 ntb_qp_link_cleanup(qp);
818 cancel_work_sync(&qp->link_cleanup);
819 cancel_delayed_work_sync(&qp->link_work);
820 }
821
822 if (!nt->link_is_up)
823 cancel_delayed_work_sync(&nt->link_work);
824
825 /* The scratchpad registers keep the values if the remote side
826 * goes down, blast them now to give them a sane value the next
827 * time they are accessed
828 */
829 count = ntb_spad_count(nt->ndev);
830 for (i = 0; i < count; i++)
831 ntb_spad_write(nt->ndev, i, 0);
832 }
833
834 static void ntb_transport_link_cleanup_work(struct work_struct *work)
835 {
836 struct ntb_transport_ctx *nt =
837 container_of(work, struct ntb_transport_ctx, link_cleanup);
838
839 ntb_transport_link_cleanup(nt);
840 }
841
842 static void ntb_transport_event_callback(void *data)
843 {
844 struct ntb_transport_ctx *nt = data;
845
846 if (ntb_link_is_up(nt->ndev, NULL, NULL) == 1)
847 schedule_delayed_work(&nt->link_work, 0);
848 else
849 schedule_work(&nt->link_cleanup);
850 }
851
852 static void ntb_transport_link_work(struct work_struct *work)
853 {
854 struct ntb_transport_ctx *nt =
855 container_of(work, struct ntb_transport_ctx, link_work.work);
856 struct ntb_dev *ndev = nt->ndev;
857 struct pci_dev *pdev = ndev->pdev;
858 resource_size_t size;
859 u32 val;
860 int rc = 0, i, spad;
861
862 /* send the local info, in the opposite order of the way we read it */
863 for (i = 0; i < nt->mw_count; i++) {
864 size = nt->mw_vec[i].phys_size;
865
866 if (max_mw_size && size > max_mw_size)
867 size = max_mw_size;
868
869 spad = MW0_SZ_HIGH + (i * 2);
870 ntb_peer_spad_write(ndev, PIDX, spad, upper_32_bits(size));
871
872 spad = MW0_SZ_LOW + (i * 2);
873 ntb_peer_spad_write(ndev, PIDX, spad, lower_32_bits(size));
874 }
875
876 ntb_peer_spad_write(ndev, PIDX, NUM_MWS, nt->mw_count);
877
878 ntb_peer_spad_write(ndev, PIDX, NUM_QPS, nt->qp_count);
879
880 ntb_peer_spad_write(ndev, PIDX, VERSION, NTB_TRANSPORT_VERSION);
881
882 /* Query the remote side for its info */
883 val = ntb_spad_read(ndev, VERSION);
884 dev_dbg(&pdev->dev, "Remote version = %d\n", val);
885 if (val != NTB_TRANSPORT_VERSION)
886 goto out;
887
888 val = ntb_spad_read(ndev, NUM_QPS);
889 dev_dbg(&pdev->dev, "Remote max number of qps = %d\n", val);
890 if (val != nt->qp_count)
891 goto out;
892
893 val = ntb_spad_read(ndev, NUM_MWS);
894 dev_dbg(&pdev->dev, "Remote number of mws = %d\n", val);
895 if (val != nt->mw_count)
896 goto out;
897
898 for (i = 0; i < nt->mw_count; i++) {
899 u64 val64;
900
901 val = ntb_spad_read(ndev, MW0_SZ_HIGH + (i * 2));
902 val64 = (u64)val << 32;
903
904 val = ntb_spad_read(ndev, MW0_SZ_LOW + (i * 2));
905 val64 |= val;
906
907 dev_dbg(&pdev->dev, "Remote MW%d size = %#llx\n", i, val64);
908
909 rc = ntb_set_mw(nt, i, val64);
910 if (rc)
911 goto out1;
912 }
913
914 nt->link_is_up = true;
915
916 for (i = 0; i < nt->qp_count; i++) {
917 struct ntb_transport_qp *qp = &nt->qp_vec[i];
918
919 ntb_transport_setup_qp_mw(nt, i);
920
921 if (qp->client_ready)
922 schedule_delayed_work(&qp->link_work, 0);
923 }
924
925 return;
926
927 out1:
928 for (i = 0; i < nt->mw_count; i++)
929 ntb_free_mw(nt, i);
930
931 /* if there's an actual failure, we should just bail */
932 if (rc < 0)
933 return;
934
935 out:
936 if (ntb_link_is_up(ndev, NULL, NULL) == 1)
937 schedule_delayed_work(&nt->link_work,
938 msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
939 }
940
941 static void ntb_qp_link_work(struct work_struct *work)
942 {
943 struct ntb_transport_qp *qp = container_of(work,
944 struct ntb_transport_qp,
945 link_work.work);
946 struct pci_dev *pdev = qp->ndev->pdev;
947 struct ntb_transport_ctx *nt = qp->transport;
948 int val;
949
950 WARN_ON(!nt->link_is_up);
951
952 val = ntb_spad_read(nt->ndev, QP_LINKS);
953
954 ntb_peer_spad_write(nt->ndev, PIDX, QP_LINKS, val | BIT(qp->qp_num));
955
956 /* query remote spad for qp ready bits */
957 dev_dbg_ratelimited(&pdev->dev, "Remote QP link status = %x\n", val);
958
959 /* See if the remote side is up */
960 if (val & BIT(qp->qp_num)) {
961 dev_info(&pdev->dev, "qp %d: Link Up\n", qp->qp_num);
962 qp->link_is_up = true;
963 qp->active = true;
964
965 if (qp->event_handler)
966 qp->event_handler(qp->cb_data, qp->link_is_up);
967
968 if (qp->active)
969 tasklet_schedule(&qp->rxc_db_work);
970 } else if (nt->link_is_up)
971 schedule_delayed_work(&qp->link_work,
972 msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
973 }
974
975 static int ntb_transport_init_queue(struct ntb_transport_ctx *nt,
976 unsigned int qp_num)
977 {
978 struct ntb_transport_qp *qp;
979 phys_addr_t mw_base;
980 resource_size_t mw_size;
981 unsigned int num_qps_mw, tx_size;
982 unsigned int mw_num, mw_count, qp_count;
983 u64 qp_offset;
984
985 mw_count = nt->mw_count;
986 qp_count = nt->qp_count;
987
988 mw_num = QP_TO_MW(nt, qp_num);
989
990 qp = &nt->qp_vec[qp_num];
991 qp->qp_num = qp_num;
992 qp->transport = nt;
993 qp->ndev = nt->ndev;
994 qp->client_ready = false;
995 qp->event_handler = NULL;
996 ntb_qp_link_down_reset(qp);
997
998 if (mw_num < qp_count % mw_count)
999 num_qps_mw = qp_count / mw_count + 1;
1000 else
1001 num_qps_mw = qp_count / mw_count;
1002
1003 mw_base = nt->mw_vec[mw_num].phys_addr;
1004 mw_size = nt->mw_vec[mw_num].phys_size;
1005
1006 if (max_mw_size && mw_size > max_mw_size)
1007 mw_size = max_mw_size;
1008
1009 tx_size = (unsigned int)mw_size / num_qps_mw;
1010 qp_offset = tx_size * (qp_num / mw_count);
1011
1012 qp->tx_mw = nt->mw_vec[mw_num].vbase + qp_offset;
1013 if (!qp->tx_mw)
1014 return -EINVAL;
1015
1016 qp->tx_mw_phys = mw_base + qp_offset;
1017 if (!qp->tx_mw_phys)
1018 return -EINVAL;
1019
1020 tx_size -= sizeof(struct ntb_rx_info);
1021 qp->rx_info = qp->tx_mw + tx_size;
1022
1023 /* Due to housekeeping, there must be atleast 2 buffs */
1024 qp->tx_max_frame = min(transport_mtu, tx_size / 2);
1025 qp->tx_max_entry = tx_size / qp->tx_max_frame;
1026
1027 if (nt->debugfs_node_dir) {
1028 char debugfs_name[4];
1029
1030 snprintf(debugfs_name, 4, "qp%d", qp_num);
1031 qp->debugfs_dir = debugfs_create_dir(debugfs_name,
1032 nt->debugfs_node_dir);
1033
1034 qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR,
1035 qp->debugfs_dir, qp,
1036 &ntb_qp_debugfs_stats);
1037 } else {
1038 qp->debugfs_dir = NULL;
1039 qp->debugfs_stats = NULL;
1040 }
1041
1042 INIT_DELAYED_WORK(&qp->link_work, ntb_qp_link_work);
1043 INIT_WORK(&qp->link_cleanup, ntb_qp_link_cleanup_work);
1044
1045 spin_lock_init(&qp->ntb_rx_q_lock);
1046 spin_lock_init(&qp->ntb_tx_free_q_lock);
1047
1048 INIT_LIST_HEAD(&qp->rx_post_q);
1049 INIT_LIST_HEAD(&qp->rx_pend_q);
1050 INIT_LIST_HEAD(&qp->rx_free_q);
1051 INIT_LIST_HEAD(&qp->tx_free_q);
1052
1053 tasklet_init(&qp->rxc_db_work, ntb_transport_rxc_db,
1054 (unsigned long)qp);
1055
1056 return 0;
1057 }
1058
1059 static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev)
1060 {
1061 struct ntb_transport_ctx *nt;
1062 struct ntb_transport_mw *mw;
1063 unsigned int mw_count, qp_count, spad_count, max_mw_count_for_spads;
1064 u64 qp_bitmap;
1065 int node;
1066 int rc, i;
1067
1068 mw_count = ntb_peer_mw_count(ndev);
1069
1070 if (!ndev->ops->mw_set_trans) {
1071 dev_err(&ndev->dev, "Inbound MW based NTB API is required\n");
1072 return -EINVAL;
1073 }
1074
1075 if (ntb_db_is_unsafe(ndev))
1076 dev_dbg(&ndev->dev,
1077 "doorbell is unsafe, proceed anyway...\n");
1078 if (ntb_spad_is_unsafe(ndev))
1079 dev_dbg(&ndev->dev,
1080 "scratchpad is unsafe, proceed anyway...\n");
1081
1082 if (ntb_peer_port_count(ndev) != NTB_DEF_PEER_CNT)
1083 dev_warn(&ndev->dev, "Multi-port NTB devices unsupported\n");
1084
1085 node = dev_to_node(&ndev->dev);
1086
1087 nt = kzalloc_node(sizeof(*nt), GFP_KERNEL, node);
1088 if (!nt)
1089 return -ENOMEM;
1090
1091 nt->ndev = ndev;
1092 spad_count = ntb_spad_count(ndev);
1093
1094 /* Limit the MW's based on the availability of scratchpads */
1095
1096 if (spad_count < NTB_TRANSPORT_MIN_SPADS) {
1097 nt->mw_count = 0;
1098 rc = -EINVAL;
1099 goto err;
1100 }
1101
1102 max_mw_count_for_spads = (spad_count - MW0_SZ_HIGH) / 2;
1103 nt->mw_count = min(mw_count, max_mw_count_for_spads);
1104
1105 nt->mw_vec = kcalloc_node(mw_count, sizeof(*nt->mw_vec),
1106 GFP_KERNEL, node);
1107 if (!nt->mw_vec) {
1108 rc = -ENOMEM;
1109 goto err;
1110 }
1111
1112 for (i = 0; i < mw_count; i++) {
1113 mw = &nt->mw_vec[i];
1114
1115 rc = ntb_peer_mw_get_addr(ndev, i, &mw->phys_addr,
1116 &mw->phys_size);
1117 if (rc)
1118 goto err1;
1119
1120 mw->vbase = ioremap_wc(mw->phys_addr, mw->phys_size);
1121 if (!mw->vbase) {
1122 rc = -ENOMEM;
1123 goto err1;
1124 }
1125
1126 mw->buff_size = 0;
1127 mw->xlat_size = 0;
1128 mw->virt_addr = NULL;
1129 mw->dma_addr = 0;
1130 }
1131
1132 qp_bitmap = ntb_db_valid_mask(ndev);
1133
1134 qp_count = ilog2(qp_bitmap);
1135 if (max_num_clients && max_num_clients < qp_count)
1136 qp_count = max_num_clients;
1137 else if (nt->mw_count < qp_count)
1138 qp_count = nt->mw_count;
1139
1140 qp_bitmap &= BIT_ULL(qp_count) - 1;
1141
1142 nt->qp_count = qp_count;
1143 nt->qp_bitmap = qp_bitmap;
1144 nt->qp_bitmap_free = qp_bitmap;
1145
1146 nt->qp_vec = kcalloc_node(qp_count, sizeof(*nt->qp_vec),
1147 GFP_KERNEL, node);
1148 if (!nt->qp_vec) {
1149 rc = -ENOMEM;
1150 goto err1;
1151 }
1152
1153 if (nt_debugfs_dir) {
1154 nt->debugfs_node_dir =
1155 debugfs_create_dir(pci_name(ndev->pdev),
1156 nt_debugfs_dir);
1157 }
1158
1159 for (i = 0; i < qp_count; i++) {
1160 rc = ntb_transport_init_queue(nt, i);
1161 if (rc)
1162 goto err2;
1163 }
1164
1165 INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work);
1166 INIT_WORK(&nt->link_cleanup, ntb_transport_link_cleanup_work);
1167
1168 rc = ntb_set_ctx(ndev, nt, &ntb_transport_ops);
1169 if (rc)
1170 goto err2;
1171
1172 INIT_LIST_HEAD(&nt->client_devs);
1173 rc = ntb_bus_init(nt);
1174 if (rc)
1175 goto err3;
1176
1177 nt->link_is_up = false;
1178 ntb_link_enable(ndev, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
1179 ntb_link_event(ndev);
1180
1181 return 0;
1182
1183 err3:
1184 ntb_clear_ctx(ndev);
1185 err2:
1186 kfree(nt->qp_vec);
1187 err1:
1188 while (i--) {
1189 mw = &nt->mw_vec[i];
1190 iounmap(mw->vbase);
1191 }
1192 kfree(nt->mw_vec);
1193 err:
1194 kfree(nt);
1195 return rc;
1196 }
1197
1198 static void ntb_transport_free(struct ntb_client *self, struct ntb_dev *ndev)
1199 {
1200 struct ntb_transport_ctx *nt = ndev->ctx;
1201 struct ntb_transport_qp *qp;
1202 u64 qp_bitmap_alloc;
1203 int i;
1204
1205 ntb_transport_link_cleanup(nt);
1206 cancel_work_sync(&nt->link_cleanup);
1207 cancel_delayed_work_sync(&nt->link_work);
1208
1209 qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
1210
1211 /* verify that all the qp's are freed */
1212 for (i = 0; i < nt->qp_count; i++) {
1213 qp = &nt->qp_vec[i];
1214 if (qp_bitmap_alloc & BIT_ULL(i))
1215 ntb_transport_free_queue(qp);
1216 debugfs_remove_recursive(qp->debugfs_dir);
1217 }
1218
1219 ntb_link_disable(ndev);
1220 ntb_clear_ctx(ndev);
1221
1222 ntb_bus_remove(nt);
1223
1224 for (i = nt->mw_count; i--; ) {
1225 ntb_free_mw(nt, i);
1226 iounmap(nt->mw_vec[i].vbase);
1227 }
1228
1229 kfree(nt->qp_vec);
1230 kfree(nt->mw_vec);
1231 kfree(nt);
1232 }
1233
1234 static void ntb_complete_rxc(struct ntb_transport_qp *qp)
1235 {
1236 struct ntb_queue_entry *entry;
1237 void *cb_data;
1238 unsigned int len;
1239 unsigned long irqflags;
1240
1241 spin_lock_irqsave(&qp->ntb_rx_q_lock, irqflags);
1242
1243 while (!list_empty(&qp->rx_post_q)) {
1244 entry = list_first_entry(&qp->rx_post_q,
1245 struct ntb_queue_entry, entry);
1246 if (!(entry->flags & DESC_DONE_FLAG))
1247 break;
1248
1249 entry->rx_hdr->flags = 0;
1250 iowrite32(entry->rx_index, &qp->rx_info->entry);
1251
1252 cb_data = entry->cb_data;
1253 len = entry->len;
1254
1255 list_move_tail(&entry->entry, &qp->rx_free_q);
1256
1257 spin_unlock_irqrestore(&qp->ntb_rx_q_lock, irqflags);
1258
1259 if (qp->rx_handler && qp->client_ready)
1260 qp->rx_handler(qp, qp->cb_data, cb_data, len);
1261
1262 spin_lock_irqsave(&qp->ntb_rx_q_lock, irqflags);
1263 }
1264
1265 spin_unlock_irqrestore(&qp->ntb_rx_q_lock, irqflags);
1266 }
1267
1268 static void ntb_rx_copy_callback(void *data,
1269 const struct dmaengine_result *res)
1270 {
1271 struct ntb_queue_entry *entry = data;
1272
1273 /* we need to check DMA results if we are using DMA */
1274 if (res) {
1275 enum dmaengine_tx_result dma_err = res->result;
1276
1277 switch (dma_err) {
1278 case DMA_TRANS_READ_FAILED:
1279 case DMA_TRANS_WRITE_FAILED:
1280 entry->errors++;
1281 case DMA_TRANS_ABORTED:
1282 {
1283 struct ntb_transport_qp *qp = entry->qp;
1284 void *offset = qp->rx_buff + qp->rx_max_frame *
1285 qp->rx_index;
1286
1287 ntb_memcpy_rx(entry, offset);
1288 qp->rx_memcpy++;
1289 return;
1290 }
1291
1292 case DMA_TRANS_NOERROR:
1293 default:
1294 break;
1295 }
1296 }
1297
1298 entry->flags |= DESC_DONE_FLAG;
1299
1300 ntb_complete_rxc(entry->qp);
1301 }
1302
1303 static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void *offset)
1304 {
1305 void *buf = entry->buf;
1306 size_t len = entry->len;
1307
1308 memcpy(buf, offset, len);
1309
1310 /* Ensure that the data is fully copied out before clearing the flag */
1311 wmb();
1312
1313 ntb_rx_copy_callback(entry, NULL);
1314 }
1315
1316 static int ntb_async_rx_submit(struct ntb_queue_entry *entry, void *offset)
1317 {
1318 struct dma_async_tx_descriptor *txd;
1319 struct ntb_transport_qp *qp = entry->qp;
1320 struct dma_chan *chan = qp->rx_dma_chan;
1321 struct dma_device *device;
1322 size_t pay_off, buff_off, len;
1323 struct dmaengine_unmap_data *unmap;
1324 dma_cookie_t cookie;
1325 void *buf = entry->buf;
1326
1327 len = entry->len;
1328 device = chan->device;
1329 pay_off = (size_t)offset & ~PAGE_MASK;
1330 buff_off = (size_t)buf & ~PAGE_MASK;
1331
1332 if (!is_dma_copy_aligned(device, pay_off, buff_off, len))
1333 goto err;
1334
1335 unmap = dmaengine_get_unmap_data(device->dev, 2, GFP_NOWAIT);
1336 if (!unmap)
1337 goto err;
1338
1339 unmap->len = len;
1340 unmap->addr[0] = dma_map_page(device->dev, virt_to_page(offset),
1341 pay_off, len, DMA_TO_DEVICE);
1342 if (dma_mapping_error(device->dev, unmap->addr[0]))
1343 goto err_get_unmap;
1344
1345 unmap->to_cnt = 1;
1346
1347 unmap->addr[1] = dma_map_page(device->dev, virt_to_page(buf),
1348 buff_off, len, DMA_FROM_DEVICE);
1349 if (dma_mapping_error(device->dev, unmap->addr[1]))
1350 goto err_get_unmap;
1351
1352 unmap->from_cnt = 1;
1353
1354 txd = device->device_prep_dma_memcpy(chan, unmap->addr[1],
1355 unmap->addr[0], len,
1356 DMA_PREP_INTERRUPT);
1357 if (!txd)
1358 goto err_get_unmap;
1359
1360 txd->callback_result = ntb_rx_copy_callback;
1361 txd->callback_param = entry;
1362 dma_set_unmap(txd, unmap);
1363
1364 cookie = dmaengine_submit(txd);
1365 if (dma_submit_error(cookie))
1366 goto err_set_unmap;
1367
1368 dmaengine_unmap_put(unmap);
1369
1370 qp->last_cookie = cookie;
1371
1372 qp->rx_async++;
1373
1374 return 0;
1375
1376 err_set_unmap:
1377 dmaengine_unmap_put(unmap);
1378 err_get_unmap:
1379 dmaengine_unmap_put(unmap);
1380 err:
1381 return -ENXIO;
1382 }
1383
1384 static void ntb_async_rx(struct ntb_queue_entry *entry, void *offset)
1385 {
1386 struct ntb_transport_qp *qp = entry->qp;
1387 struct dma_chan *chan = qp->rx_dma_chan;
1388 int res;
1389
1390 if (!chan)
1391 goto err;
1392
1393 if (entry->len < copy_bytes)
1394 goto err;
1395
1396 res = ntb_async_rx_submit(entry, offset);
1397 if (res < 0)
1398 goto err;
1399
1400 if (!entry->retries)
1401 qp->rx_async++;
1402
1403 return;
1404
1405 err:
1406 ntb_memcpy_rx(entry, offset);
1407 qp->rx_memcpy++;
1408 }
1409
1410 static int ntb_process_rxc(struct ntb_transport_qp *qp)
1411 {
1412 struct ntb_payload_header *hdr;
1413 struct ntb_queue_entry *entry;
1414 void *offset;
1415
1416 offset = qp->rx_buff + qp->rx_max_frame * qp->rx_index;
1417 hdr = offset + qp->rx_max_frame - sizeof(struct ntb_payload_header);
1418
1419 dev_dbg(&qp->ndev->pdev->dev, "qp %d: RX ver %u len %d flags %x\n",
1420 qp->qp_num, hdr->ver, hdr->len, hdr->flags);
1421
1422 if (!(hdr->flags & DESC_DONE_FLAG)) {
1423 dev_dbg(&qp->ndev->pdev->dev, "done flag not set\n");
1424 qp->rx_ring_empty++;
1425 return -EAGAIN;
1426 }
1427
1428 if (hdr->flags & LINK_DOWN_FLAG) {
1429 dev_dbg(&qp->ndev->pdev->dev, "link down flag set\n");
1430 ntb_qp_link_down(qp);
1431 hdr->flags = 0;
1432 return -EAGAIN;
1433 }
1434
1435 if (hdr->ver != (u32)qp->rx_pkts) {
1436 dev_dbg(&qp->ndev->pdev->dev,
1437 "version mismatch, expected %llu - got %u\n",
1438 qp->rx_pkts, hdr->ver);
1439 qp->rx_err_ver++;
1440 return -EIO;
1441 }
1442
1443 entry = ntb_list_mv(&qp->ntb_rx_q_lock, &qp->rx_pend_q, &qp->rx_post_q);
1444 if (!entry) {
1445 dev_dbg(&qp->ndev->pdev->dev, "no receive buffer\n");
1446 qp->rx_err_no_buf++;
1447 return -EAGAIN;
1448 }
1449
1450 entry->rx_hdr = hdr;
1451 entry->rx_index = qp->rx_index;
1452
1453 if (hdr->len > entry->len) {
1454 dev_dbg(&qp->ndev->pdev->dev,
1455 "receive buffer overflow! Wanted %d got %d\n",
1456 hdr->len, entry->len);
1457 qp->rx_err_oflow++;
1458
1459 entry->len = -EIO;
1460 entry->flags |= DESC_DONE_FLAG;
1461
1462 ntb_complete_rxc(qp);
1463 } else {
1464 dev_dbg(&qp->ndev->pdev->dev,
1465 "RX OK index %u ver %u size %d into buf size %d\n",
1466 qp->rx_index, hdr->ver, hdr->len, entry->len);
1467
1468 qp->rx_bytes += hdr->len;
1469 qp->rx_pkts++;
1470
1471 entry->len = hdr->len;
1472
1473 ntb_async_rx(entry, offset);
1474 }
1475
1476 qp->rx_index++;
1477 qp->rx_index %= qp->rx_max_entry;
1478
1479 return 0;
1480 }
1481
1482 static void ntb_transport_rxc_db(unsigned long data)
1483 {
1484 struct ntb_transport_qp *qp = (void *)data;
1485 int rc, i;
1486
1487 dev_dbg(&qp->ndev->pdev->dev, "%s: doorbell %d received\n",
1488 __func__, qp->qp_num);
1489
1490 /* Limit the number of packets processed in a single interrupt to
1491 * provide fairness to others
1492 */
1493 for (i = 0; i < qp->rx_max_entry; i++) {
1494 rc = ntb_process_rxc(qp);
1495 if (rc)
1496 break;
1497 }
1498
1499 if (i && qp->rx_dma_chan)
1500 dma_async_issue_pending(qp->rx_dma_chan);
1501
1502 if (i == qp->rx_max_entry) {
1503 /* there is more work to do */
1504 if (qp->active)
1505 tasklet_schedule(&qp->rxc_db_work);
1506 } else if (ntb_db_read(qp->ndev) & BIT_ULL(qp->qp_num)) {
1507 /* the doorbell bit is set: clear it */
1508 ntb_db_clear(qp->ndev, BIT_ULL(qp->qp_num));
1509 /* ntb_db_read ensures ntb_db_clear write is committed */
1510 ntb_db_read(qp->ndev);
1511
1512 /* an interrupt may have arrived between finishing
1513 * ntb_process_rxc and clearing the doorbell bit:
1514 * there might be some more work to do.
1515 */
1516 if (qp->active)
1517 tasklet_schedule(&qp->rxc_db_work);
1518 }
1519 }
1520
1521 static void ntb_tx_copy_callback(void *data,
1522 const struct dmaengine_result *res)
1523 {
1524 struct ntb_queue_entry *entry = data;
1525 struct ntb_transport_qp *qp = entry->qp;
1526 struct ntb_payload_header __iomem *hdr = entry->tx_hdr;
1527
1528 /* we need to check DMA results if we are using DMA */
1529 if (res) {
1530 enum dmaengine_tx_result dma_err = res->result;
1531
1532 switch (dma_err) {
1533 case DMA_TRANS_READ_FAILED:
1534 case DMA_TRANS_WRITE_FAILED:
1535 entry->errors++;
1536 case DMA_TRANS_ABORTED:
1537 {
1538 void __iomem *offset =
1539 qp->tx_mw + qp->tx_max_frame *
1540 entry->tx_index;
1541
1542 /* resubmit via CPU */
1543 ntb_memcpy_tx(entry, offset);
1544 qp->tx_memcpy++;
1545 return;
1546 }
1547
1548 case DMA_TRANS_NOERROR:
1549 default:
1550 break;
1551 }
1552 }
1553
1554 iowrite32(entry->flags | DESC_DONE_FLAG, &hdr->flags);
1555
1556 ntb_peer_db_set(qp->ndev, BIT_ULL(qp->qp_num));
1557
1558 /* The entry length can only be zero if the packet is intended to be a
1559 * "link down" or similar. Since no payload is being sent in these
1560 * cases, there is nothing to add to the completion queue.
1561 */
1562 if (entry->len > 0) {
1563 qp->tx_bytes += entry->len;
1564
1565 if (qp->tx_handler)
1566 qp->tx_handler(qp, qp->cb_data, entry->cb_data,
1567 entry->len);
1568 }
1569
1570 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q);
1571 }
1572
1573 static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset)
1574 {
1575 #ifdef ARCH_HAS_NOCACHE_UACCESS
1576 /*
1577 * Using non-temporal mov to improve performance on non-cached
1578 * writes, even though we aren't actually copying from user space.
1579 */
1580 __copy_from_user_inatomic_nocache(offset, entry->buf, entry->len);
1581 #else
1582 memcpy_toio(offset, entry->buf, entry->len);
1583 #endif
1584
1585 /* Ensure that the data is fully copied out before setting the flags */
1586 wmb();
1587
1588 ntb_tx_copy_callback(entry, NULL);
1589 }
1590
1591 static int ntb_async_tx_submit(struct ntb_transport_qp *qp,
1592 struct ntb_queue_entry *entry)
1593 {
1594 struct dma_async_tx_descriptor *txd;
1595 struct dma_chan *chan = qp->tx_dma_chan;
1596 struct dma_device *device;
1597 size_t len = entry->len;
1598 void *buf = entry->buf;
1599 size_t dest_off, buff_off;
1600 struct dmaengine_unmap_data *unmap;
1601 dma_addr_t dest;
1602 dma_cookie_t cookie;
1603
1604 device = chan->device;
1605 dest = qp->tx_mw_phys + qp->tx_max_frame * entry->tx_index;
1606 buff_off = (size_t)buf & ~PAGE_MASK;
1607 dest_off = (size_t)dest & ~PAGE_MASK;
1608
1609 if (!is_dma_copy_aligned(device, buff_off, dest_off, len))
1610 goto err;
1611
1612 unmap = dmaengine_get_unmap_data(device->dev, 1, GFP_NOWAIT);
1613 if (!unmap)
1614 goto err;
1615
1616 unmap->len = len;
1617 unmap->addr[0] = dma_map_page(device->dev, virt_to_page(buf),
1618 buff_off, len, DMA_TO_DEVICE);
1619 if (dma_mapping_error(device->dev, unmap->addr[0]))
1620 goto err_get_unmap;
1621
1622 unmap->to_cnt = 1;
1623
1624 txd = device->device_prep_dma_memcpy(chan, dest, unmap->addr[0], len,
1625 DMA_PREP_INTERRUPT);
1626 if (!txd)
1627 goto err_get_unmap;
1628
1629 txd->callback_result = ntb_tx_copy_callback;
1630 txd->callback_param = entry;
1631 dma_set_unmap(txd, unmap);
1632
1633 cookie = dmaengine_submit(txd);
1634 if (dma_submit_error(cookie))
1635 goto err_set_unmap;
1636
1637 dmaengine_unmap_put(unmap);
1638
1639 dma_async_issue_pending(chan);
1640
1641 return 0;
1642 err_set_unmap:
1643 dmaengine_unmap_put(unmap);
1644 err_get_unmap:
1645 dmaengine_unmap_put(unmap);
1646 err:
1647 return -ENXIO;
1648 }
1649
1650 static void ntb_async_tx(struct ntb_transport_qp *qp,
1651 struct ntb_queue_entry *entry)
1652 {
1653 struct ntb_payload_header __iomem *hdr;
1654 struct dma_chan *chan = qp->tx_dma_chan;
1655 void __iomem *offset;
1656 int res;
1657
1658 entry->tx_index = qp->tx_index;
1659 offset = qp->tx_mw + qp->tx_max_frame * entry->tx_index;
1660 hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
1661 entry->tx_hdr = hdr;
1662
1663 iowrite32(entry->len, &hdr->len);
1664 iowrite32((u32)qp->tx_pkts, &hdr->ver);
1665
1666 if (!chan)
1667 goto err;
1668
1669 if (entry->len < copy_bytes)
1670 goto err;
1671
1672 res = ntb_async_tx_submit(qp, entry);
1673 if (res < 0)
1674 goto err;
1675
1676 if (!entry->retries)
1677 qp->tx_async++;
1678
1679 return;
1680
1681 err:
1682 ntb_memcpy_tx(entry, offset);
1683 qp->tx_memcpy++;
1684 }
1685
1686 static int ntb_process_tx(struct ntb_transport_qp *qp,
1687 struct ntb_queue_entry *entry)
1688 {
1689 if (qp->tx_index == qp->remote_rx_info->entry) {
1690 qp->tx_ring_full++;
1691 return -EAGAIN;
1692 }
1693
1694 if (entry->len > qp->tx_max_frame - sizeof(struct ntb_payload_header)) {
1695 if (qp->tx_handler)
1696 qp->tx_handler(qp, qp->cb_data, NULL, -EIO);
1697
1698 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1699 &qp->tx_free_q);
1700 return 0;
1701 }
1702
1703 ntb_async_tx(qp, entry);
1704
1705 qp->tx_index++;
1706 qp->tx_index %= qp->tx_max_entry;
1707
1708 qp->tx_pkts++;
1709
1710 return 0;
1711 }
1712
1713 static void ntb_send_link_down(struct ntb_transport_qp *qp)
1714 {
1715 struct pci_dev *pdev = qp->ndev->pdev;
1716 struct ntb_queue_entry *entry;
1717 int i, rc;
1718
1719 if (!qp->link_is_up)
1720 return;
1721
1722 dev_info(&pdev->dev, "qp %d: Send Link Down\n", qp->qp_num);
1723
1724 for (i = 0; i < NTB_LINK_DOWN_TIMEOUT; i++) {
1725 entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1726 if (entry)
1727 break;
1728 msleep(100);
1729 }
1730
1731 if (!entry)
1732 return;
1733
1734 entry->cb_data = NULL;
1735 entry->buf = NULL;
1736 entry->len = 0;
1737 entry->flags = LINK_DOWN_FLAG;
1738
1739 rc = ntb_process_tx(qp, entry);
1740 if (rc)
1741 dev_err(&pdev->dev, "ntb: QP%d unable to send linkdown msg\n",
1742 qp->qp_num);
1743
1744 ntb_qp_link_down_reset(qp);
1745 }
1746
1747 static bool ntb_dma_filter_fn(struct dma_chan *chan, void *node)
1748 {
1749 return dev_to_node(&chan->dev->device) == (int)(unsigned long)node;
1750 }
1751
1752 /**
1753 * ntb_transport_create_queue - Create a new NTB transport layer queue
1754 * @rx_handler: receive callback function
1755 * @tx_handler: transmit callback function
1756 * @event_handler: event callback function
1757 *
1758 * Create a new NTB transport layer queue and provide the queue with a callback
1759 * routine for both transmit and receive. The receive callback routine will be
1760 * used to pass up data when the transport has received it on the queue. The
1761 * transmit callback routine will be called when the transport has completed the
1762 * transmission of the data on the queue and the data is ready to be freed.
1763 *
1764 * RETURNS: pointer to newly created ntb_queue, NULL on error.
1765 */
1766 struct ntb_transport_qp *
1767 ntb_transport_create_queue(void *data, struct device *client_dev,
1768 const struct ntb_queue_handlers *handlers)
1769 {
1770 struct ntb_dev *ndev;
1771 struct pci_dev *pdev;
1772 struct ntb_transport_ctx *nt;
1773 struct ntb_queue_entry *entry;
1774 struct ntb_transport_qp *qp;
1775 u64 qp_bit;
1776 unsigned int free_queue;
1777 dma_cap_mask_t dma_mask;
1778 int node;
1779 int i;
1780
1781 ndev = dev_ntb(client_dev->parent);
1782 pdev = ndev->pdev;
1783 nt = ndev->ctx;
1784
1785 node = dev_to_node(&ndev->dev);
1786
1787 free_queue = ffs(nt->qp_bitmap_free);
1788 if (!free_queue)
1789 goto err;
1790
1791 /* decrement free_queue to make it zero based */
1792 free_queue--;
1793
1794 qp = &nt->qp_vec[free_queue];
1795 qp_bit = BIT_ULL(qp->qp_num);
1796
1797 nt->qp_bitmap_free &= ~qp_bit;
1798
1799 qp->cb_data = data;
1800 qp->rx_handler = handlers->rx_handler;
1801 qp->tx_handler = handlers->tx_handler;
1802 qp->event_handler = handlers->event_handler;
1803
1804 dma_cap_zero(dma_mask);
1805 dma_cap_set(DMA_MEMCPY, dma_mask);
1806
1807 if (use_dma) {
1808 qp->tx_dma_chan =
1809 dma_request_channel(dma_mask, ntb_dma_filter_fn,
1810 (void *)(unsigned long)node);
1811 if (!qp->tx_dma_chan)
1812 dev_info(&pdev->dev, "Unable to allocate TX DMA channel\n");
1813
1814 qp->rx_dma_chan =
1815 dma_request_channel(dma_mask, ntb_dma_filter_fn,
1816 (void *)(unsigned long)node);
1817 if (!qp->rx_dma_chan)
1818 dev_info(&pdev->dev, "Unable to allocate RX DMA channel\n");
1819 } else {
1820 qp->tx_dma_chan = NULL;
1821 qp->rx_dma_chan = NULL;
1822 }
1823
1824 dev_dbg(&pdev->dev, "Using %s memcpy for TX\n",
1825 qp->tx_dma_chan ? "DMA" : "CPU");
1826
1827 dev_dbg(&pdev->dev, "Using %s memcpy for RX\n",
1828 qp->rx_dma_chan ? "DMA" : "CPU");
1829
1830 for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
1831 entry = kzalloc_node(sizeof(*entry), GFP_KERNEL, node);
1832 if (!entry)
1833 goto err1;
1834
1835 entry->qp = qp;
1836 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry,
1837 &qp->rx_free_q);
1838 }
1839 qp->rx_alloc_entry = NTB_QP_DEF_NUM_ENTRIES;
1840
1841 for (i = 0; i < qp->tx_max_entry; i++) {
1842 entry = kzalloc_node(sizeof(*entry), GFP_KERNEL, node);
1843 if (!entry)
1844 goto err2;
1845
1846 entry->qp = qp;
1847 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1848 &qp->tx_free_q);
1849 }
1850
1851 ntb_db_clear(qp->ndev, qp_bit);
1852 ntb_db_clear_mask(qp->ndev, qp_bit);
1853
1854 dev_info(&pdev->dev, "NTB Transport QP %d created\n", qp->qp_num);
1855
1856 return qp;
1857
1858 err2:
1859 while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1860 kfree(entry);
1861 err1:
1862 qp->rx_alloc_entry = 0;
1863 while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
1864 kfree(entry);
1865 if (qp->tx_dma_chan)
1866 dma_release_channel(qp->tx_dma_chan);
1867 if (qp->rx_dma_chan)
1868 dma_release_channel(qp->rx_dma_chan);
1869 nt->qp_bitmap_free |= qp_bit;
1870 err:
1871 return NULL;
1872 }
1873 EXPORT_SYMBOL_GPL(ntb_transport_create_queue);
1874
1875 /**
1876 * ntb_transport_free_queue - Frees NTB transport queue
1877 * @qp: NTB queue to be freed
1878 *
1879 * Frees NTB transport queue
1880 */
1881 void ntb_transport_free_queue(struct ntb_transport_qp *qp)
1882 {
1883 struct pci_dev *pdev;
1884 struct ntb_queue_entry *entry;
1885 u64 qp_bit;
1886
1887 if (!qp)
1888 return;
1889
1890 pdev = qp->ndev->pdev;
1891
1892 qp->active = false;
1893
1894 if (qp->tx_dma_chan) {
1895 struct dma_chan *chan = qp->tx_dma_chan;
1896 /* Putting the dma_chan to NULL will force any new traffic to be
1897 * processed by the CPU instead of the DAM engine
1898 */
1899 qp->tx_dma_chan = NULL;
1900
1901 /* Try to be nice and wait for any queued DMA engine
1902 * transactions to process before smashing it with a rock
1903 */
1904 dma_sync_wait(chan, qp->last_cookie);
1905 dmaengine_terminate_all(chan);
1906 dma_release_channel(chan);
1907 }
1908
1909 if (qp->rx_dma_chan) {
1910 struct dma_chan *chan = qp->rx_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->rx_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 qp_bit = BIT_ULL(qp->qp_num);
1925
1926 ntb_db_set_mask(qp->ndev, qp_bit);
1927 tasklet_kill(&qp->rxc_db_work);
1928
1929 cancel_delayed_work_sync(&qp->link_work);
1930
1931 qp->cb_data = NULL;
1932 qp->rx_handler = NULL;
1933 qp->tx_handler = NULL;
1934 qp->event_handler = NULL;
1935
1936 while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
1937 kfree(entry);
1938
1939 while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_pend_q))) {
1940 dev_warn(&pdev->dev, "Freeing item from non-empty rx_pend_q\n");
1941 kfree(entry);
1942 }
1943
1944 while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_post_q))) {
1945 dev_warn(&pdev->dev, "Freeing item from non-empty rx_post_q\n");
1946 kfree(entry);
1947 }
1948
1949 while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1950 kfree(entry);
1951
1952 qp->transport->qp_bitmap_free |= qp_bit;
1953
1954 dev_info(&pdev->dev, "NTB Transport QP %d freed\n", qp->qp_num);
1955 }
1956 EXPORT_SYMBOL_GPL(ntb_transport_free_queue);
1957
1958 /**
1959 * ntb_transport_rx_remove - Dequeues enqueued rx packet
1960 * @qp: NTB queue to be freed
1961 * @len: pointer to variable to write enqueued buffers length
1962 *
1963 * Dequeues unused buffers from receive queue. Should only be used during
1964 * shutdown of qp.
1965 *
1966 * RETURNS: NULL error value on error, or void* for success.
1967 */
1968 void *ntb_transport_rx_remove(struct ntb_transport_qp *qp, unsigned int *len)
1969 {
1970 struct ntb_queue_entry *entry;
1971 void *buf;
1972
1973 if (!qp || qp->client_ready)
1974 return NULL;
1975
1976 entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_pend_q);
1977 if (!entry)
1978 return NULL;
1979
1980 buf = entry->cb_data;
1981 *len = entry->len;
1982
1983 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_free_q);
1984
1985 return buf;
1986 }
1987 EXPORT_SYMBOL_GPL(ntb_transport_rx_remove);
1988
1989 /**
1990 * ntb_transport_rx_enqueue - Enqueue a new NTB queue entry
1991 * @qp: NTB transport layer queue the entry is to be enqueued on
1992 * @cb: per buffer pointer for callback function to use
1993 * @data: pointer to data buffer that incoming packets will be copied into
1994 * @len: length of the data buffer
1995 *
1996 * Enqueue a new receive buffer onto the transport queue into which a NTB
1997 * payload can be received into.
1998 *
1999 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
2000 */
2001 int ntb_transport_rx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
2002 unsigned int len)
2003 {
2004 struct ntb_queue_entry *entry;
2005
2006 if (!qp)
2007 return -EINVAL;
2008
2009 entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q);
2010 if (!entry)
2011 return -ENOMEM;
2012
2013 entry->cb_data = cb;
2014 entry->buf = data;
2015 entry->len = len;
2016 entry->flags = 0;
2017 entry->retries = 0;
2018 entry->errors = 0;
2019 entry->rx_index = 0;
2020
2021 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_pend_q);
2022
2023 if (qp->active)
2024 tasklet_schedule(&qp->rxc_db_work);
2025
2026 return 0;
2027 }
2028 EXPORT_SYMBOL_GPL(ntb_transport_rx_enqueue);
2029
2030 /**
2031 * ntb_transport_tx_enqueue - Enqueue a new NTB queue entry
2032 * @qp: NTB transport layer queue the entry is to be enqueued on
2033 * @cb: per buffer pointer for callback function to use
2034 * @data: pointer to data buffer that will be sent
2035 * @len: length of the data buffer
2036 *
2037 * Enqueue a new transmit buffer onto the transport queue from which a NTB
2038 * payload will be transmitted. This assumes that a lock is being held to
2039 * serialize access to the qp.
2040 *
2041 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
2042 */
2043 int ntb_transport_tx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
2044 unsigned int len)
2045 {
2046 struct ntb_queue_entry *entry;
2047 int rc;
2048
2049 if (!qp || !qp->link_is_up || !len)
2050 return -EINVAL;
2051
2052 entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
2053 if (!entry) {
2054 qp->tx_err_no_buf++;
2055 return -EBUSY;
2056 }
2057
2058 entry->cb_data = cb;
2059 entry->buf = data;
2060 entry->len = len;
2061 entry->flags = 0;
2062 entry->errors = 0;
2063 entry->retries = 0;
2064 entry->tx_index = 0;
2065
2066 rc = ntb_process_tx(qp, entry);
2067 if (rc)
2068 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
2069 &qp->tx_free_q);
2070
2071 return rc;
2072 }
2073 EXPORT_SYMBOL_GPL(ntb_transport_tx_enqueue);
2074
2075 /**
2076 * ntb_transport_link_up - Notify NTB transport of client readiness to use queue
2077 * @qp: NTB transport layer queue to be enabled
2078 *
2079 * Notify NTB transport layer of client readiness to use queue
2080 */
2081 void ntb_transport_link_up(struct ntb_transport_qp *qp)
2082 {
2083 if (!qp)
2084 return;
2085
2086 qp->client_ready = true;
2087
2088 if (qp->transport->link_is_up)
2089 schedule_delayed_work(&qp->link_work, 0);
2090 }
2091 EXPORT_SYMBOL_GPL(ntb_transport_link_up);
2092
2093 /**
2094 * ntb_transport_link_down - Notify NTB transport to no longer enqueue data
2095 * @qp: NTB transport layer queue to be disabled
2096 *
2097 * Notify NTB transport layer of client's desire to no longer receive data on
2098 * transport queue specified. It is the client's responsibility to ensure all
2099 * entries on queue are purged or otherwise handled appropriately.
2100 */
2101 void ntb_transport_link_down(struct ntb_transport_qp *qp)
2102 {
2103 int val;
2104
2105 if (!qp)
2106 return;
2107
2108 qp->client_ready = false;
2109
2110 val = ntb_spad_read(qp->ndev, QP_LINKS);
2111
2112 ntb_peer_spad_write(qp->ndev, PIDX, QP_LINKS, val & ~BIT(qp->qp_num));
2113
2114 if (qp->link_is_up)
2115 ntb_send_link_down(qp);
2116 else
2117 cancel_delayed_work_sync(&qp->link_work);
2118 }
2119 EXPORT_SYMBOL_GPL(ntb_transport_link_down);
2120
2121 /**
2122 * ntb_transport_link_query - Query transport link state
2123 * @qp: NTB transport layer queue to be queried
2124 *
2125 * Query connectivity to the remote system of the NTB transport queue
2126 *
2127 * RETURNS: true for link up or false for link down
2128 */
2129 bool ntb_transport_link_query(struct ntb_transport_qp *qp)
2130 {
2131 if (!qp)
2132 return false;
2133
2134 return qp->link_is_up;
2135 }
2136 EXPORT_SYMBOL_GPL(ntb_transport_link_query);
2137
2138 /**
2139 * ntb_transport_qp_num - Query the qp number
2140 * @qp: NTB transport layer queue to be queried
2141 *
2142 * Query qp number of the NTB transport queue
2143 *
2144 * RETURNS: a zero based number specifying the qp number
2145 */
2146 unsigned char ntb_transport_qp_num(struct ntb_transport_qp *qp)
2147 {
2148 if (!qp)
2149 return 0;
2150
2151 return qp->qp_num;
2152 }
2153 EXPORT_SYMBOL_GPL(ntb_transport_qp_num);
2154
2155 /**
2156 * ntb_transport_max_size - Query the max payload size of a qp
2157 * @qp: NTB transport layer queue to be queried
2158 *
2159 * Query the maximum payload size permissible on the given qp
2160 *
2161 * RETURNS: the max payload size of a qp
2162 */
2163 unsigned int ntb_transport_max_size(struct ntb_transport_qp *qp)
2164 {
2165 unsigned int max_size;
2166 unsigned int copy_align;
2167 struct dma_chan *rx_chan, *tx_chan;
2168
2169 if (!qp)
2170 return 0;
2171
2172 rx_chan = qp->rx_dma_chan;
2173 tx_chan = qp->tx_dma_chan;
2174
2175 copy_align = max(rx_chan ? rx_chan->device->copy_align : 0,
2176 tx_chan ? tx_chan->device->copy_align : 0);
2177
2178 /* If DMA engine usage is possible, try to find the max size for that */
2179 max_size = qp->tx_max_frame - sizeof(struct ntb_payload_header);
2180 max_size = round_down(max_size, 1 << copy_align);
2181
2182 return max_size;
2183 }
2184 EXPORT_SYMBOL_GPL(ntb_transport_max_size);
2185
2186 unsigned int ntb_transport_tx_free_entry(struct ntb_transport_qp *qp)
2187 {
2188 unsigned int head = qp->tx_index;
2189 unsigned int tail = qp->remote_rx_info->entry;
2190
2191 return tail > head ? tail - head : qp->tx_max_entry + tail - head;
2192 }
2193 EXPORT_SYMBOL_GPL(ntb_transport_tx_free_entry);
2194
2195 static void ntb_transport_doorbell_callback(void *data, int vector)
2196 {
2197 struct ntb_transport_ctx *nt = data;
2198 struct ntb_transport_qp *qp;
2199 u64 db_bits;
2200 unsigned int qp_num;
2201
2202 db_bits = (nt->qp_bitmap & ~nt->qp_bitmap_free &
2203 ntb_db_vector_mask(nt->ndev, vector));
2204
2205 while (db_bits) {
2206 qp_num = __ffs(db_bits);
2207 qp = &nt->qp_vec[qp_num];
2208
2209 if (qp->active)
2210 tasklet_schedule(&qp->rxc_db_work);
2211
2212 db_bits &= ~BIT_ULL(qp_num);
2213 }
2214 }
2215
2216 static const struct ntb_ctx_ops ntb_transport_ops = {
2217 .link_event = ntb_transport_event_callback,
2218 .db_event = ntb_transport_doorbell_callback,
2219 };
2220
2221 static struct ntb_client ntb_transport_client = {
2222 .ops = {
2223 .probe = ntb_transport_probe,
2224 .remove = ntb_transport_free,
2225 },
2226 };
2227
2228 static int __init ntb_transport_init(void)
2229 {
2230 int rc;
2231
2232 pr_info("%s, version %s\n", NTB_TRANSPORT_DESC, NTB_TRANSPORT_VER);
2233
2234 if (debugfs_initialized())
2235 nt_debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
2236
2237 rc = bus_register(&ntb_transport_bus);
2238 if (rc)
2239 goto err_bus;
2240
2241 rc = ntb_register_client(&ntb_transport_client);
2242 if (rc)
2243 goto err_client;
2244
2245 return 0;
2246
2247 err_client:
2248 bus_unregister(&ntb_transport_bus);
2249 err_bus:
2250 debugfs_remove_recursive(nt_debugfs_dir);
2251 return rc;
2252 }
2253 module_init(ntb_transport_init);
2254
2255 static void __exit ntb_transport_exit(void)
2256 {
2257 ntb_unregister_client(&ntb_transport_client);
2258 bus_unregister(&ntb_transport_bus);
2259 debugfs_remove_recursive(nt_debugfs_dir);
2260 }
2261 module_exit(ntb_transport_exit);
Linux with added FPC-III support