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signal/alpha: Document a conflict with SI_USER for SIGTRAP
[cris-mirror.git] / drivers / ntb / ntb_transport.c
blob9a03c5871efe675015418e6f5e1ebd1745faaac0
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 resource_size_t xlat_align;
195 resource_size_t xlat_align_size;
196 void __iomem *vbase;
197 size_t xlat_size;
198 size_t buff_size;
199 void *virt_addr;
200 dma_addr_t dma_addr;
201 };
202
203 struct ntb_transport_client_dev {
204 struct list_head entry;
205 struct ntb_transport_ctx *nt;
206 struct device dev;
207 };
208
209 struct ntb_transport_ctx {
210 struct list_head entry;
211 struct list_head client_devs;
212
213 struct ntb_dev *ndev;
214
215 struct ntb_transport_mw *mw_vec;
216 struct ntb_transport_qp *qp_vec;
217 unsigned int mw_count;
218 unsigned int qp_count;
219 u64 qp_bitmap;
220 u64 qp_bitmap_free;
221
222 bool link_is_up;
223 struct delayed_work link_work;
224 struct work_struct link_cleanup;
225
226 struct dentry *debugfs_node_dir;
227 };
228
229 enum {
230 DESC_DONE_FLAG = BIT(0),
231 LINK_DOWN_FLAG = BIT(1),
232 };
233
234 struct ntb_payload_header {
235 unsigned int ver;
236 unsigned int len;
237 unsigned int flags;
238 };
239
240 enum {
241 VERSION = 0,
242 QP_LINKS,
243 NUM_QPS,
244 NUM_MWS,
245 MW0_SZ_HIGH,
246 MW0_SZ_LOW,
247 };
248
249 #define dev_client_dev(__dev) \
250 container_of((__dev), struct ntb_transport_client_dev, dev)
251
252 #define drv_client(__drv) \
253 container_of((__drv), struct ntb_transport_client, driver)
254
255 #define QP_TO_MW(nt, qp) ((qp) % nt->mw_count)
256 #define NTB_QP_DEF_NUM_ENTRIES 100
257 #define NTB_LINK_DOWN_TIMEOUT 10
258
259 static void ntb_transport_rxc_db(unsigned long data);
260 static const struct ntb_ctx_ops ntb_transport_ops;
261 static struct ntb_client ntb_transport_client;
262 static int ntb_async_tx_submit(struct ntb_transport_qp *qp,
263 struct ntb_queue_entry *entry);
264 static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset);
265 static int ntb_async_rx_submit(struct ntb_queue_entry *entry, void *offset);
266 static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void *offset);
267
268
269 static int ntb_transport_bus_match(struct device *dev,
270 struct device_driver *drv)
271 {
272 return !strncmp(dev_name(dev), drv->name, strlen(drv->name));
273 }
274
275 static int ntb_transport_bus_probe(struct device *dev)
276 {
277 const struct ntb_transport_client *client;
278 int rc = -EINVAL;
279
280 get_device(dev);
281
282 client = drv_client(dev->driver);
283 rc = client->probe(dev);
284 if (rc)
285 put_device(dev);
286
287 return rc;
288 }
289
290 static int ntb_transport_bus_remove(struct device *dev)
291 {
292 const struct ntb_transport_client *client;
293
294 client = drv_client(dev->driver);
295 client->remove(dev);
296
297 put_device(dev);
298
299 return 0;
300 }
301
302 static struct bus_type ntb_transport_bus = {
303 .name = "ntb_transport",
304 .match = ntb_transport_bus_match,
305 .probe = ntb_transport_bus_probe,
306 .remove = ntb_transport_bus_remove,
307 };
308
309 static LIST_HEAD(ntb_transport_list);
310
311 static int ntb_bus_init(struct ntb_transport_ctx *nt)
312 {
313 list_add_tail(&nt->entry, &ntb_transport_list);
314 return 0;
315 }
316
317 static void ntb_bus_remove(struct ntb_transport_ctx *nt)
318 {
319 struct ntb_transport_client_dev *client_dev, *cd;
320
321 list_for_each_entry_safe(client_dev, cd, &nt->client_devs, entry) {
322 dev_err(client_dev->dev.parent, "%s still attached to bus, removing\n",
323 dev_name(&client_dev->dev));
324 list_del(&client_dev->entry);
325 device_unregister(&client_dev->dev);
326 }
327
328 list_del(&nt->entry);
329 }
330
331 static void ntb_transport_client_release(struct device *dev)
332 {
333 struct ntb_transport_client_dev *client_dev;
334
335 client_dev = dev_client_dev(dev);
336 kfree(client_dev);
337 }
338
339 /**
340 * ntb_transport_unregister_client_dev - Unregister NTB client device
341 * @device_name: Name of NTB client device
342 *
343 * Unregister an NTB client device with the NTB transport layer
344 */
345 void ntb_transport_unregister_client_dev(char *device_name)
346 {
347 struct ntb_transport_client_dev *client, *cd;
348 struct ntb_transport_ctx *nt;
349
350 list_for_each_entry(nt, &ntb_transport_list, entry)
351 list_for_each_entry_safe(client, cd, &nt->client_devs, entry)
352 if (!strncmp(dev_name(&client->dev), device_name,
353 strlen(device_name))) {
354 list_del(&client->entry);
355 device_unregister(&client->dev);
356 }
357 }
358 EXPORT_SYMBOL_GPL(ntb_transport_unregister_client_dev);
359
360 /**
361 * ntb_transport_register_client_dev - Register NTB client device
362 * @device_name: Name of NTB client device
363 *
364 * Register an NTB client device with the NTB transport layer
365 */
366 int ntb_transport_register_client_dev(char *device_name)
367 {
368 struct ntb_transport_client_dev *client_dev;
369 struct ntb_transport_ctx *nt;
370 int node;
371 int rc, i = 0;
372
373 if (list_empty(&ntb_transport_list))
374 return -ENODEV;
375
376 list_for_each_entry(nt, &ntb_transport_list, entry) {
377 struct device *dev;
378
379 node = dev_to_node(&nt->ndev->dev);
380
381 client_dev = kzalloc_node(sizeof(*client_dev),
382 GFP_KERNEL, node);
383 if (!client_dev) {
384 rc = -ENOMEM;
385 goto err;
386 }
387
388 dev = &client_dev->dev;
389
390 /* setup and register client devices */
391 dev_set_name(dev, "%s%d", device_name, i);
392 dev->bus = &ntb_transport_bus;
393 dev->release = ntb_transport_client_release;
394 dev->parent = &nt->ndev->dev;
395
396 rc = device_register(dev);
397 if (rc) {
398 kfree(client_dev);
399 goto err;
400 }
401
402 list_add_tail(&client_dev->entry, &nt->client_devs);
403 i++;
404 }
405
406 return 0;
407
408 err:
409 ntb_transport_unregister_client_dev(device_name);
410
411 return rc;
412 }
413 EXPORT_SYMBOL_GPL(ntb_transport_register_client_dev);
414
415 /**
416 * ntb_transport_register_client - Register NTB client driver
417 * @drv: NTB client driver to be registered
418 *
419 * Register an NTB client driver with the NTB transport layer
420 *
421 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
422 */
423 int ntb_transport_register_client(struct ntb_transport_client *drv)
424 {
425 drv->driver.bus = &ntb_transport_bus;
426
427 if (list_empty(&ntb_transport_list))
428 return -ENODEV;
429
430 return driver_register(&drv->driver);
431 }
432 EXPORT_SYMBOL_GPL(ntb_transport_register_client);
433
434 /**
435 * ntb_transport_unregister_client - Unregister NTB client driver
436 * @drv: NTB client driver to be unregistered
437 *
438 * Unregister an NTB client driver with the NTB transport layer
439 *
440 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
441 */
442 void ntb_transport_unregister_client(struct ntb_transport_client *drv)
443 {
444 driver_unregister(&drv->driver);
445 }
446 EXPORT_SYMBOL_GPL(ntb_transport_unregister_client);
447
448 static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count,
449 loff_t *offp)
450 {
451 struct ntb_transport_qp *qp;
452 char *buf;
453 ssize_t ret, out_offset, out_count;
454
455 qp = filp->private_data;
456
457 if (!qp || !qp->link_is_up)
458 return 0;
459
460 out_count = 1000;
461
462 buf = kmalloc(out_count, GFP_KERNEL);
463 if (!buf)
464 return -ENOMEM;
465
466 out_offset = 0;
467 out_offset += snprintf(buf + out_offset, out_count - out_offset,
468 "\nNTB QP stats:\n\n");
469 out_offset += snprintf(buf + out_offset, out_count - out_offset,
470 "rx_bytes - \t%llu\n", qp->rx_bytes);
471 out_offset += snprintf(buf + out_offset, out_count - out_offset,
472 "rx_pkts - \t%llu\n", qp->rx_pkts);
473 out_offset += snprintf(buf + out_offset, out_count - out_offset,
474 "rx_memcpy - \t%llu\n", qp->rx_memcpy);
475 out_offset += snprintf(buf + out_offset, out_count - out_offset,
476 "rx_async - \t%llu\n", qp->rx_async);
477 out_offset += snprintf(buf + out_offset, out_count - out_offset,
478 "rx_ring_empty - %llu\n", qp->rx_ring_empty);
479 out_offset += snprintf(buf + out_offset, out_count - out_offset,
480 "rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
481 out_offset += snprintf(buf + out_offset, out_count - out_offset,
482 "rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
483 out_offset += snprintf(buf + out_offset, out_count - out_offset,
484 "rx_err_ver - \t%llu\n", qp->rx_err_ver);
485 out_offset += snprintf(buf + out_offset, out_count - out_offset,
486 "rx_buff - \t0x%p\n", qp->rx_buff);
487 out_offset += snprintf(buf + out_offset, out_count - out_offset,
488 "rx_index - \t%u\n", qp->rx_index);
489 out_offset += snprintf(buf + out_offset, out_count - out_offset,
490 "rx_max_entry - \t%u\n", qp->rx_max_entry);
491 out_offset += snprintf(buf + out_offset, out_count - out_offset,
492 "rx_alloc_entry - \t%u\n\n", qp->rx_alloc_entry);
493
494 out_offset += snprintf(buf + out_offset, out_count - out_offset,
495 "tx_bytes - \t%llu\n", qp->tx_bytes);
496 out_offset += snprintf(buf + out_offset, out_count - out_offset,
497 "tx_pkts - \t%llu\n", qp->tx_pkts);
498 out_offset += snprintf(buf + out_offset, out_count - out_offset,
499 "tx_memcpy - \t%llu\n", qp->tx_memcpy);
500 out_offset += snprintf(buf + out_offset, out_count - out_offset,
501 "tx_async - \t%llu\n", qp->tx_async);
502 out_offset += snprintf(buf + out_offset, out_count - out_offset,
503 "tx_ring_full - \t%llu\n", qp->tx_ring_full);
504 out_offset += snprintf(buf + out_offset, out_count - out_offset,
505 "tx_err_no_buf - %llu\n", qp->tx_err_no_buf);
506 out_offset += snprintf(buf + out_offset, out_count - out_offset,
507 "tx_mw - \t0x%p\n", qp->tx_mw);
508 out_offset += snprintf(buf + out_offset, out_count - out_offset,
509 "tx_index (H) - \t%u\n", qp->tx_index);
510 out_offset += snprintf(buf + out_offset, out_count - out_offset,
511 "RRI (T) - \t%u\n",
512 qp->remote_rx_info->entry);
513 out_offset += snprintf(buf + out_offset, out_count - out_offset,
514 "tx_max_entry - \t%u\n", qp->tx_max_entry);
515 out_offset += snprintf(buf + out_offset, out_count - out_offset,
516 "free tx - \t%u\n",
517 ntb_transport_tx_free_entry(qp));
518
519 out_offset += snprintf(buf + out_offset, out_count - out_offset,
520 "\n");
521 out_offset += snprintf(buf + out_offset, out_count - out_offset,
522 "Using TX DMA - \t%s\n",
523 qp->tx_dma_chan ? "Yes" : "No");
524 out_offset += snprintf(buf + out_offset, out_count - out_offset,
525 "Using RX DMA - \t%s\n",
526 qp->rx_dma_chan ? "Yes" : "No");
527 out_offset += snprintf(buf + out_offset, out_count - out_offset,
528 "QP Link - \t%s\n",
529 qp->link_is_up ? "Up" : "Down");
530 out_offset += snprintf(buf + out_offset, out_count - out_offset,
531 "\n");
532
533 if (out_offset > out_count)
534 out_offset = out_count;
535
536 ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
537 kfree(buf);
538 return ret;
539 }
540
541 static const struct file_operations ntb_qp_debugfs_stats = {
542 .owner = THIS_MODULE,
543 .open = simple_open,
544 .read = debugfs_read,
545 };
546
547 static void ntb_list_add(spinlock_t *lock, struct list_head *entry,
548 struct list_head *list)
549 {
550 unsigned long flags;
551
552 spin_lock_irqsave(lock, flags);
553 list_add_tail(entry, list);
554 spin_unlock_irqrestore(lock, flags);
555 }
556
557 static struct ntb_queue_entry *ntb_list_rm(spinlock_t *lock,
558 struct list_head *list)
559 {
560 struct ntb_queue_entry *entry;
561 unsigned long flags;
562
563 spin_lock_irqsave(lock, flags);
564 if (list_empty(list)) {
565 entry = NULL;
566 goto out;
567 }
568 entry = list_first_entry(list, struct ntb_queue_entry, entry);
569 list_del(&entry->entry);
570
571 out:
572 spin_unlock_irqrestore(lock, flags);
573
574 return entry;
575 }
576
577 static struct ntb_queue_entry *ntb_list_mv(spinlock_t *lock,
578 struct list_head *list,
579 struct list_head *to_list)
580 {
581 struct ntb_queue_entry *entry;
582 unsigned long flags;
583
584 spin_lock_irqsave(lock, flags);
585
586 if (list_empty(list)) {
587 entry = NULL;
588 } else {
589 entry = list_first_entry(list, struct ntb_queue_entry, entry);
590 list_move_tail(&entry->entry, to_list);
591 }
592
593 spin_unlock_irqrestore(lock, flags);
594
595 return entry;
596 }
597
598 static int ntb_transport_setup_qp_mw(struct ntb_transport_ctx *nt,
599 unsigned int qp_num)
600 {
601 struct ntb_transport_qp *qp = &nt->qp_vec[qp_num];
602 struct ntb_transport_mw *mw;
603 struct ntb_dev *ndev = nt->ndev;
604 struct ntb_queue_entry *entry;
605 unsigned int rx_size, num_qps_mw;
606 unsigned int mw_num, mw_count, qp_count;
607 unsigned int i;
608 int node;
609
610 mw_count = nt->mw_count;
611 qp_count = nt->qp_count;
612
613 mw_num = QP_TO_MW(nt, qp_num);
614 mw = &nt->mw_vec[mw_num];
615
616 if (!mw->virt_addr)
617 return -ENOMEM;
618
619 if (mw_num < qp_count % mw_count)
620 num_qps_mw = qp_count / mw_count + 1;
621 else
622 num_qps_mw = qp_count / mw_count;
623
624 rx_size = (unsigned int)mw->xlat_size / num_qps_mw;
625 qp->rx_buff = mw->virt_addr + rx_size * (qp_num / mw_count);
626 rx_size -= sizeof(struct ntb_rx_info);
627
628 qp->remote_rx_info = qp->rx_buff + rx_size;
629
630 /* Due to housekeeping, there must be atleast 2 buffs */
631 qp->rx_max_frame = min(transport_mtu, rx_size / 2);
632 qp->rx_max_entry = rx_size / qp->rx_max_frame;
633 qp->rx_index = 0;
634
635 /*
636 * Checking to see if we have more entries than the default.
637 * We should add additional entries if that is the case so we
638 * can be in sync with the transport frames.
639 */
640 node = dev_to_node(&ndev->dev);
641 for (i = qp->rx_alloc_entry; i < qp->rx_max_entry; i++) {
642 entry = kzalloc_node(sizeof(*entry), GFP_ATOMIC, node);
643 if (!entry)
644 return -ENOMEM;
645
646 entry->qp = qp;
647 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry,
648 &qp->rx_free_q);
649 qp->rx_alloc_entry++;
650 }
651
652 qp->remote_rx_info->entry = qp->rx_max_entry - 1;
653
654 /* setup the hdr offsets with 0's */
655 for (i = 0; i < qp->rx_max_entry; i++) {
656 void *offset = (qp->rx_buff + qp->rx_max_frame * (i + 1) -
657 sizeof(struct ntb_payload_header));
658 memset(offset, 0, sizeof(struct ntb_payload_header));
659 }
660
661 qp->rx_pkts = 0;
662 qp->tx_pkts = 0;
663 qp->tx_index = 0;
664
665 return 0;
666 }
667
668 static void ntb_free_mw(struct ntb_transport_ctx *nt, int num_mw)
669 {
670 struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
671 struct pci_dev *pdev = nt->ndev->pdev;
672
673 if (!mw->virt_addr)
674 return;
675
676 ntb_mw_clear_trans(nt->ndev, PIDX, num_mw);
677 dma_free_coherent(&pdev->dev, mw->buff_size,
678 mw->virt_addr, mw->dma_addr);
679 mw->xlat_size = 0;
680 mw->buff_size = 0;
681 mw->virt_addr = NULL;
682 }
683
684 static int ntb_set_mw(struct ntb_transport_ctx *nt, int num_mw,
685 resource_size_t size)
686 {
687 struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
688 struct pci_dev *pdev = nt->ndev->pdev;
689 size_t xlat_size, buff_size;
690 int rc;
691
692 if (!size)
693 return -EINVAL;
694
695 xlat_size = round_up(size, mw->xlat_align_size);
696 buff_size = round_up(size, mw->xlat_align);
697
698 /* No need to re-setup */
699 if (mw->xlat_size == xlat_size)
700 return 0;
701
702 if (mw->buff_size)
703 ntb_free_mw(nt, num_mw);
704
705 /* Alloc memory for receiving data. Must be aligned */
706 mw->xlat_size = xlat_size;
707 mw->buff_size = buff_size;
708
709 mw->virt_addr = dma_alloc_coherent(&pdev->dev, buff_size,
710 &mw->dma_addr, GFP_KERNEL);
711 if (!mw->virt_addr) {
712 mw->xlat_size = 0;
713 mw->buff_size = 0;
714 dev_err(&pdev->dev, "Unable to alloc MW buff of size %zu\n",
715 buff_size);
716 return -ENOMEM;
717 }
718
719 /*
720 * we must ensure that the memory address allocated is BAR size
721 * aligned in order for the XLAT register to take the value. This
722 * is a requirement of the hardware. It is recommended to setup CMA
723 * for BAR sizes equal or greater than 4MB.
724 */
725 if (!IS_ALIGNED(mw->dma_addr, mw->xlat_align)) {
726 dev_err(&pdev->dev, "DMA memory %pad is not aligned\n",
727 &mw->dma_addr);
728 ntb_free_mw(nt, num_mw);
729 return -ENOMEM;
730 }
731
732 /* Notify HW the memory location of the receive buffer */
733 rc = ntb_mw_set_trans(nt->ndev, PIDX, num_mw, mw->dma_addr,
734 mw->xlat_size);
735 if (rc) {
736 dev_err(&pdev->dev, "Unable to set mw%d translation", num_mw);
737 ntb_free_mw(nt, num_mw);
738 return -EIO;
739 }
740
741 return 0;
742 }
743
744 static void ntb_qp_link_down_reset(struct ntb_transport_qp *qp)
745 {
746 qp->link_is_up = false;
747 qp->active = false;
748
749 qp->tx_index = 0;
750 qp->rx_index = 0;
751 qp->rx_bytes = 0;
752 qp->rx_pkts = 0;
753 qp->rx_ring_empty = 0;
754 qp->rx_err_no_buf = 0;
755 qp->rx_err_oflow = 0;
756 qp->rx_err_ver = 0;
757 qp->rx_memcpy = 0;
758 qp->rx_async = 0;
759 qp->tx_bytes = 0;
760 qp->tx_pkts = 0;
761 qp->tx_ring_full = 0;
762 qp->tx_err_no_buf = 0;
763 qp->tx_memcpy = 0;
764 qp->tx_async = 0;
765 }
766
767 static void ntb_qp_link_cleanup(struct ntb_transport_qp *qp)
768 {
769 struct ntb_transport_ctx *nt = qp->transport;
770 struct pci_dev *pdev = nt->ndev->pdev;
771
772 dev_info(&pdev->dev, "qp %d: Link Cleanup\n", qp->qp_num);
773
774 cancel_delayed_work_sync(&qp->link_work);
775 ntb_qp_link_down_reset(qp);
776
777 if (qp->event_handler)
778 qp->event_handler(qp->cb_data, qp->link_is_up);
779 }
780
781 static void ntb_qp_link_cleanup_work(struct work_struct *work)
782 {
783 struct ntb_transport_qp *qp = container_of(work,
784 struct ntb_transport_qp,
785 link_cleanup);
786 struct ntb_transport_ctx *nt = qp->transport;
787
788 ntb_qp_link_cleanup(qp);
789
790 if (nt->link_is_up)
791 schedule_delayed_work(&qp->link_work,
792 msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
793 }
794
795 static void ntb_qp_link_down(struct ntb_transport_qp *qp)
796 {
797 schedule_work(&qp->link_cleanup);
798 }
799
800 static void ntb_transport_link_cleanup(struct ntb_transport_ctx *nt)
801 {
802 struct ntb_transport_qp *qp;
803 u64 qp_bitmap_alloc;
804 unsigned int i, count;
805
806 qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
807
808 /* Pass along the info to any clients */
809 for (i = 0; i < nt->qp_count; i++)
810 if (qp_bitmap_alloc & BIT_ULL(i)) {
811 qp = &nt->qp_vec[i];
812 ntb_qp_link_cleanup(qp);
813 cancel_work_sync(&qp->link_cleanup);
814 cancel_delayed_work_sync(&qp->link_work);
815 }
816
817 if (!nt->link_is_up)
818 cancel_delayed_work_sync(&nt->link_work);
819
820 /* The scratchpad registers keep the values if the remote side
821 * goes down, blast them now to give them a sane value the next
822 * time they are accessed
823 */
824 count = ntb_spad_count(nt->ndev);
825 for (i = 0; i < count; i++)
826 ntb_spad_write(nt->ndev, i, 0);
827 }
828
829 static void ntb_transport_link_cleanup_work(struct work_struct *work)
830 {
831 struct ntb_transport_ctx *nt =
832 container_of(work, struct ntb_transport_ctx, link_cleanup);
833
834 ntb_transport_link_cleanup(nt);
835 }
836
837 static void ntb_transport_event_callback(void *data)
838 {
839 struct ntb_transport_ctx *nt = data;
840
841 if (ntb_link_is_up(nt->ndev, NULL, NULL) == 1)
842 schedule_delayed_work(&nt->link_work, 0);
843 else
844 schedule_work(&nt->link_cleanup);
845 }
846
847 static void ntb_transport_link_work(struct work_struct *work)
848 {
849 struct ntb_transport_ctx *nt =
850 container_of(work, struct ntb_transport_ctx, link_work.work);
851 struct ntb_dev *ndev = nt->ndev;
852 struct pci_dev *pdev = ndev->pdev;
853 resource_size_t size;
854 u32 val;
855 int rc = 0, i, spad;
856
857 /* send the local info, in the opposite order of the way we read it */
858 for (i = 0; i < nt->mw_count; i++) {
859 size = nt->mw_vec[i].phys_size;
860
861 if (max_mw_size && size > max_mw_size)
862 size = max_mw_size;
863
864 spad = MW0_SZ_HIGH + (i * 2);
865 ntb_peer_spad_write(ndev, PIDX, spad, upper_32_bits(size));
866
867 spad = MW0_SZ_LOW + (i * 2);
868 ntb_peer_spad_write(ndev, PIDX, spad, lower_32_bits(size));
869 }
870
871 ntb_peer_spad_write(ndev, PIDX, NUM_MWS, nt->mw_count);
872
873 ntb_peer_spad_write(ndev, PIDX, NUM_QPS, nt->qp_count);
874
875 ntb_peer_spad_write(ndev, PIDX, VERSION, NTB_TRANSPORT_VERSION);
876
877 /* Query the remote side for its info */
878 val = ntb_spad_read(ndev, VERSION);
879 dev_dbg(&pdev->dev, "Remote version = %d\n", val);
880 if (val != NTB_TRANSPORT_VERSION)
881 goto out;
882
883 val = ntb_spad_read(ndev, NUM_QPS);
884 dev_dbg(&pdev->dev, "Remote max number of qps = %d\n", val);
885 if (val != nt->qp_count)
886 goto out;
887
888 val = ntb_spad_read(ndev, NUM_MWS);
889 dev_dbg(&pdev->dev, "Remote number of mws = %d\n", val);
890 if (val != nt->mw_count)
891 goto out;
892
893 for (i = 0; i < nt->mw_count; i++) {
894 u64 val64;
895
896 val = ntb_spad_read(ndev, MW0_SZ_HIGH + (i * 2));
897 val64 = (u64)val << 32;
898
899 val = ntb_spad_read(ndev, MW0_SZ_LOW + (i * 2));
900 val64 |= val;
901
902 dev_dbg(&pdev->dev, "Remote MW%d size = %#llx\n", i, val64);
903
904 rc = ntb_set_mw(nt, i, val64);
905 if (rc)
906 goto out1;
907 }
908
909 nt->link_is_up = true;
910
911 for (i = 0; i < nt->qp_count; i++) {
912 struct ntb_transport_qp *qp = &nt->qp_vec[i];
913
914 ntb_transport_setup_qp_mw(nt, i);
915
916 if (qp->client_ready)
917 schedule_delayed_work(&qp->link_work, 0);
918 }
919
920 return;
921
922 out1:
923 for (i = 0; i < nt->mw_count; i++)
924 ntb_free_mw(nt, i);
925
926 /* if there's an actual failure, we should just bail */
927 if (rc < 0) {
928 ntb_link_disable(ndev);
929 return;
930 }
931
932 out:
933 if (ntb_link_is_up(ndev, NULL, NULL) == 1)
934 schedule_delayed_work(&nt->link_work,
935 msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
936 }
937
938 static void ntb_qp_link_work(struct work_struct *work)
939 {
940 struct ntb_transport_qp *qp = container_of(work,
941 struct ntb_transport_qp,
942 link_work.work);
943 struct pci_dev *pdev = qp->ndev->pdev;
944 struct ntb_transport_ctx *nt = qp->transport;
945 int val;
946
947 WARN_ON(!nt->link_is_up);
948
949 val = ntb_spad_read(nt->ndev, QP_LINKS);
950
951 ntb_peer_spad_write(nt->ndev, PIDX, QP_LINKS, val | BIT(qp->qp_num));
952
953 /* query remote spad for qp ready bits */
954 dev_dbg_ratelimited(&pdev->dev, "Remote QP link status = %x\n", val);
955
956 /* See if the remote side is up */
957 if (val & BIT(qp->qp_num)) {
958 dev_info(&pdev->dev, "qp %d: Link Up\n", qp->qp_num);
959 qp->link_is_up = true;
960 qp->active = true;
961
962 if (qp->event_handler)
963 qp->event_handler(qp->cb_data, qp->link_is_up);
964
965 if (qp->active)
966 tasklet_schedule(&qp->rxc_db_work);
967 } else if (nt->link_is_up)
968 schedule_delayed_work(&qp->link_work,
969 msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
970 }
971
972 static int ntb_transport_init_queue(struct ntb_transport_ctx *nt,
973 unsigned int qp_num)
974 {
975 struct ntb_transport_qp *qp;
976 phys_addr_t mw_base;
977 resource_size_t mw_size;
978 unsigned int num_qps_mw, tx_size;
979 unsigned int mw_num, mw_count, qp_count;
980 u64 qp_offset;
981
982 mw_count = nt->mw_count;
983 qp_count = nt->qp_count;
984
985 mw_num = QP_TO_MW(nt, qp_num);
986
987 qp = &nt->qp_vec[qp_num];
988 qp->qp_num = qp_num;
989 qp->transport = nt;
990 qp->ndev = nt->ndev;
991 qp->client_ready = false;
992 qp->event_handler = NULL;
993 ntb_qp_link_down_reset(qp);
994
995 if (mw_num < qp_count % mw_count)
996 num_qps_mw = qp_count / mw_count + 1;
997 else
998 num_qps_mw = qp_count / mw_count;
999
1000 mw_base = nt->mw_vec[mw_num].phys_addr;
1001 mw_size = nt->mw_vec[mw_num].phys_size;
1002
1003 tx_size = (unsigned int)mw_size / num_qps_mw;
1004 qp_offset = tx_size * (qp_num / mw_count);
1005
1006 qp->tx_mw = nt->mw_vec[mw_num].vbase + qp_offset;
1007 if (!qp->tx_mw)
1008 return -EINVAL;
1009
1010 qp->tx_mw_phys = mw_base + qp_offset;
1011 if (!qp->tx_mw_phys)
1012 return -EINVAL;
1013
1014 tx_size -= sizeof(struct ntb_rx_info);
1015 qp->rx_info = qp->tx_mw + tx_size;
1016
1017 /* Due to housekeeping, there must be atleast 2 buffs */
1018 qp->tx_max_frame = min(transport_mtu, tx_size / 2);
1019 qp->tx_max_entry = tx_size / qp->tx_max_frame;
1020
1021 if (nt->debugfs_node_dir) {
1022 char debugfs_name[4];
1023
1024 snprintf(debugfs_name, 4, "qp%d", qp_num);
1025 qp->debugfs_dir = debugfs_create_dir(debugfs_name,
1026 nt->debugfs_node_dir);
1027
1028 qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR,
1029 qp->debugfs_dir, qp,
1030 &ntb_qp_debugfs_stats);
1031 } else {
1032 qp->debugfs_dir = NULL;
1033 qp->debugfs_stats = NULL;
1034 }
1035
1036 INIT_DELAYED_WORK(&qp->link_work, ntb_qp_link_work);
1037 INIT_WORK(&qp->link_cleanup, ntb_qp_link_cleanup_work);
1038
1039 spin_lock_init(&qp->ntb_rx_q_lock);
1040 spin_lock_init(&qp->ntb_tx_free_q_lock);
1041
1042 INIT_LIST_HEAD(&qp->rx_post_q);
1043 INIT_LIST_HEAD(&qp->rx_pend_q);
1044 INIT_LIST_HEAD(&qp->rx_free_q);
1045 INIT_LIST_HEAD(&qp->tx_free_q);
1046
1047 tasklet_init(&qp->rxc_db_work, ntb_transport_rxc_db,
1048 (unsigned long)qp);
1049
1050 return 0;
1051 }
1052
1053 static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev)
1054 {
1055 struct ntb_transport_ctx *nt;
1056 struct ntb_transport_mw *mw;
1057 unsigned int mw_count, qp_count, spad_count, max_mw_count_for_spads;
1058 u64 qp_bitmap;
1059 int node;
1060 int rc, i;
1061
1062 mw_count = ntb_mw_count(ndev, PIDX);
1063
1064 if (!ndev->ops->mw_set_trans) {
1065 dev_err(&ndev->dev, "Inbound MW based NTB API is required\n");
1066 return -EINVAL;
1067 }
1068
1069 if (ntb_db_is_unsafe(ndev))
1070 dev_dbg(&ndev->dev,
1071 "doorbell is unsafe, proceed anyway...\n");
1072 if (ntb_spad_is_unsafe(ndev))
1073 dev_dbg(&ndev->dev,
1074 "scratchpad is unsafe, proceed anyway...\n");
1075
1076 if (ntb_peer_port_count(ndev) != NTB_DEF_PEER_CNT)
1077 dev_warn(&ndev->dev, "Multi-port NTB devices unsupported\n");
1078
1079 node = dev_to_node(&ndev->dev);
1080
1081 nt = kzalloc_node(sizeof(*nt), GFP_KERNEL, node);
1082 if (!nt)
1083 return -ENOMEM;
1084
1085 nt->ndev = ndev;
1086 spad_count = ntb_spad_count(ndev);
1087
1088 /* Limit the MW's based on the availability of scratchpads */
1089
1090 if (spad_count < NTB_TRANSPORT_MIN_SPADS) {
1091 nt->mw_count = 0;
1092 rc = -EINVAL;
1093 goto err;
1094 }
1095
1096 max_mw_count_for_spads = (spad_count - MW0_SZ_HIGH) / 2;
1097 nt->mw_count = min(mw_count, max_mw_count_for_spads);
1098
1099 nt->mw_vec = kzalloc_node(mw_count * sizeof(*nt->mw_vec),
1100 GFP_KERNEL, node);
1101 if (!nt->mw_vec) {
1102 rc = -ENOMEM;
1103 goto err;
1104 }
1105
1106 for (i = 0; i < mw_count; i++) {
1107 mw = &nt->mw_vec[i];
1108
1109 rc = ntb_mw_get_align(ndev, PIDX, i, &mw->xlat_align,
1110 &mw->xlat_align_size, NULL);
1111 if (rc)
1112 goto err1;
1113
1114 rc = ntb_peer_mw_get_addr(ndev, i, &mw->phys_addr,
1115 &mw->phys_size);
1116 if (rc)
1117 goto err1;
1118
1119 mw->vbase = ioremap_wc(mw->phys_addr, mw->phys_size);
1120 if (!mw->vbase) {
1121 rc = -ENOMEM;
1122 goto err1;
1123 }
1124
1125 mw->buff_size = 0;
1126 mw->xlat_size = 0;
1127 mw->virt_addr = NULL;
1128 mw->dma_addr = 0;
1129 }
1130
1131 qp_bitmap = ntb_db_valid_mask(ndev);
1132
1133 qp_count = ilog2(qp_bitmap);
1134 if (max_num_clients && max_num_clients < qp_count)
1135 qp_count = max_num_clients;
1136 else if (nt->mw_count < qp_count)
1137 qp_count = nt->mw_count;
1138
1139 qp_bitmap &= BIT_ULL(qp_count) - 1;
1140
1141 nt->qp_count = qp_count;
1142 nt->qp_bitmap = qp_bitmap;
1143 nt->qp_bitmap_free = qp_bitmap;
1144
1145 nt->qp_vec = kzalloc_node(qp_count * sizeof(*nt->qp_vec),
1146 GFP_KERNEL, node);
1147 if (!nt->qp_vec) {
1148 rc = -ENOMEM;
1149 goto err1;
1150 }
1151
1152 if (nt_debugfs_dir) {
1153 nt->debugfs_node_dir =
1154 debugfs_create_dir(pci_name(ndev->pdev),
1155 nt_debugfs_dir);
1156 }
1157
1158 for (i = 0; i < qp_count; i++) {
1159 rc = ntb_transport_init_queue(nt, i);
1160 if (rc)
1161 goto err2;
1162 }
1163
1164 INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work);
1165 INIT_WORK(&nt->link_cleanup, ntb_transport_link_cleanup_work);
1166
1167 rc = ntb_set_ctx(ndev, nt, &ntb_transport_ops);
1168 if (rc)
1169 goto err2;
1170
1171 INIT_LIST_HEAD(&nt->client_devs);
1172 rc = ntb_bus_init(nt);
1173 if (rc)
1174 goto err3;
1175
1176 nt->link_is_up = false;
1177 ntb_link_enable(ndev, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
1178 ntb_link_event(ndev);
1179
1180 return 0;
1181
1182 err3:
1183 ntb_clear_ctx(ndev);
1184 err2:
1185 kfree(nt->qp_vec);
1186 err1:
1187 while (i--) {
1188 mw = &nt->mw_vec[i];
1189 iounmap(mw->vbase);
1190 }
1191 kfree(nt->mw_vec);
1192 err:
1193 kfree(nt);
1194 return rc;
1195 }
1196
1197 static void ntb_transport_free(struct ntb_client *self, struct ntb_dev *ndev)
1198 {
1199 struct ntb_transport_ctx *nt = ndev->ctx;
1200 struct ntb_transport_qp *qp;
1201 u64 qp_bitmap_alloc;
1202 int i;
1203
1204 ntb_transport_link_cleanup(nt);
1205 cancel_work_sync(&nt->link_cleanup);
1206 cancel_delayed_work_sync(&nt->link_work);
1207
1208 qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
1209
1210 /* verify that all the qp's are freed */
1211 for (i = 0; i < nt->qp_count; i++) {
1212 qp = &nt->qp_vec[i];
1213 if (qp_bitmap_alloc & BIT_ULL(i))
1214 ntb_transport_free_queue(qp);
1215 debugfs_remove_recursive(qp->debugfs_dir);
1216 }
1217
1218 ntb_link_disable(ndev);
1219 ntb_clear_ctx(ndev);
1220
1221 ntb_bus_remove(nt);
1222
1223 for (i = nt->mw_count; i--; ) {
1224 ntb_free_mw(nt, i);
1225 iounmap(nt->mw_vec[i].vbase);
1226 }
1227
1228 kfree(nt->qp_vec);
1229 kfree(nt->mw_vec);
1230 kfree(nt);
1231 }
1232
1233 static void ntb_complete_rxc(struct ntb_transport_qp *qp)
1234 {
1235 struct ntb_queue_entry *entry;
1236 void *cb_data;
1237 unsigned int len;
1238 unsigned long irqflags;
1239
1240 spin_lock_irqsave(&qp->ntb_rx_q_lock, irqflags);
1241
1242 while (!list_empty(&qp->rx_post_q)) {
1243 entry = list_first_entry(&qp->rx_post_q,
1244 struct ntb_queue_entry, entry);
1245 if (!(entry->flags & DESC_DONE_FLAG))
1246 break;
1247
1248 entry->rx_hdr->flags = 0;
1249 iowrite32(entry->rx_index, &qp->rx_info->entry);
1250
1251 cb_data = entry->cb_data;
1252 len = entry->len;
1253
1254 list_move_tail(&entry->entry, &qp->rx_free_q);
1255
1256 spin_unlock_irqrestore(&qp->ntb_rx_q_lock, irqflags);
1257
1258 if (qp->rx_handler && qp->client_ready)
1259 qp->rx_handler(qp, qp->cb_data, cb_data, len);
1260
1261 spin_lock_irqsave(&qp->ntb_rx_q_lock, irqflags);
1262 }
1263
1264 spin_unlock_irqrestore(&qp->ntb_rx_q_lock, irqflags);
1265 }
1266
1267 static void ntb_rx_copy_callback(void *data,
1268 const struct dmaengine_result *res)
1269 {
1270 struct ntb_queue_entry *entry = data;
1271
1272 /* we need to check DMA results if we are using DMA */
1273 if (res) {
1274 enum dmaengine_tx_result dma_err = res->result;
1275
1276 switch (dma_err) {
1277 case DMA_TRANS_READ_FAILED:
1278 case DMA_TRANS_WRITE_FAILED:
1279 entry->errors++;
1280 case DMA_TRANS_ABORTED:
1281 {
1282 struct ntb_transport_qp *qp = entry->qp;
1283 void *offset = qp->rx_buff + qp->rx_max_frame *
1284 qp->rx_index;
1285
1286 ntb_memcpy_rx(entry, offset);
1287 qp->rx_memcpy++;
1288 return;
1289 }
1290
1291 case DMA_TRANS_NOERROR:
1292 default:
1293 break;
1294 }
1295 }
1296
1297 entry->flags |= DESC_DONE_FLAG;
1298
1299 ntb_complete_rxc(entry->qp);
1300 }
1301
1302 static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void *offset)
1303 {
1304 void *buf = entry->buf;
1305 size_t len = entry->len;
1306
1307 memcpy(buf, offset, len);
1308
1309 /* Ensure that the data is fully copied out before clearing the flag */
1310 wmb();
1311
1312 ntb_rx_copy_callback(entry, NULL);
1313 }
1314
1315 static int ntb_async_rx_submit(struct ntb_queue_entry *entry, void *offset)
1316 {
1317 struct dma_async_tx_descriptor *txd;
1318 struct ntb_transport_qp *qp = entry->qp;
1319 struct dma_chan *chan = qp->rx_dma_chan;
1320 struct dma_device *device;
1321 size_t pay_off, buff_off, len;
1322 struct dmaengine_unmap_data *unmap;
1323 dma_cookie_t cookie;
1324 void *buf = entry->buf;
1325
1326 len = entry->len;
1327 device = chan->device;
1328 pay_off = (size_t)offset & ~PAGE_MASK;
1329 buff_off = (size_t)buf & ~PAGE_MASK;
1330
1331 if (!is_dma_copy_aligned(device, pay_off, buff_off, len))
1332 goto err;
1333
1334 unmap = dmaengine_get_unmap_data(device->dev, 2, GFP_NOWAIT);
1335 if (!unmap)
1336 goto err;
1337
1338 unmap->len = len;
1339 unmap->addr[0] = dma_map_page(device->dev, virt_to_page(offset),
1340 pay_off, len, DMA_TO_DEVICE);
1341 if (dma_mapping_error(device->dev, unmap->addr[0]))
1342 goto err_get_unmap;
1343
1344 unmap->to_cnt = 1;
1345
1346 unmap->addr[1] = dma_map_page(device->dev, virt_to_page(buf),
1347 buff_off, len, DMA_FROM_DEVICE);
1348 if (dma_mapping_error(device->dev, unmap->addr[1]))
1349 goto err_get_unmap;
1350
1351 unmap->from_cnt = 1;
1352
1353 txd = device->device_prep_dma_memcpy(chan, unmap->addr[1],
1354 unmap->addr[0], len,
1355 DMA_PREP_INTERRUPT);
1356 if (!txd)
1357 goto err_get_unmap;
1358
1359 txd->callback_result = ntb_rx_copy_callback;
1360 txd->callback_param = entry;
1361 dma_set_unmap(txd, unmap);
1362
1363 cookie = dmaengine_submit(txd);
1364 if (dma_submit_error(cookie))
1365 goto err_set_unmap;
1366
1367 dmaengine_unmap_put(unmap);
1368
1369 qp->last_cookie = cookie;
1370
1371 qp->rx_async++;
1372
1373 return 0;
1374
1375 err_set_unmap:
1376 dmaengine_unmap_put(unmap);
1377 err_get_unmap:
1378 dmaengine_unmap_put(unmap);
1379 err:
1380 return -ENXIO;
1381 }
1382
1383 static void ntb_async_rx(struct ntb_queue_entry *entry, void *offset)
1384 {
1385 struct ntb_transport_qp *qp = entry->qp;
1386 struct dma_chan *chan = qp->rx_dma_chan;
1387 int res;
1388
1389 if (!chan)
1390 goto err;
1391
1392 if (entry->len < copy_bytes)
1393 goto err;
1394
1395 res = ntb_async_rx_submit(entry, offset);
1396 if (res < 0)
1397 goto err;
1398
1399 if (!entry->retries)
1400 qp->rx_async++;
1401
1402 return;
1403
1404 err:
1405 ntb_memcpy_rx(entry, offset);
1406 qp->rx_memcpy++;
1407 }
1408
1409 static int ntb_process_rxc(struct ntb_transport_qp *qp)
1410 {
1411 struct ntb_payload_header *hdr;
1412 struct ntb_queue_entry *entry;
1413 void *offset;
1414
1415 offset = qp->rx_buff + qp->rx_max_frame * qp->rx_index;
1416 hdr = offset + qp->rx_max_frame - sizeof(struct ntb_payload_header);
1417
1418 dev_dbg(&qp->ndev->pdev->dev, "qp %d: RX ver %u len %d flags %x\n",
1419 qp->qp_num, hdr->ver, hdr->len, hdr->flags);
1420
1421 if (!(hdr->flags & DESC_DONE_FLAG)) {
1422 dev_dbg(&qp->ndev->pdev->dev, "done flag not set\n");
1423 qp->rx_ring_empty++;
1424 return -EAGAIN;
1425 }
1426
1427 if (hdr->flags & LINK_DOWN_FLAG) {
1428 dev_dbg(&qp->ndev->pdev->dev, "link down flag set\n");
1429 ntb_qp_link_down(qp);
1430 hdr->flags = 0;
1431 return -EAGAIN;
1432 }
1433
1434 if (hdr->ver != (u32)qp->rx_pkts) {
1435 dev_dbg(&qp->ndev->pdev->dev,
1436 "version mismatch, expected %llu - got %u\n",
1437 qp->rx_pkts, hdr->ver);
1438 qp->rx_err_ver++;
1439 return -EIO;
1440 }
1441
1442 entry = ntb_list_mv(&qp->ntb_rx_q_lock, &qp->rx_pend_q, &qp->rx_post_q);
1443 if (!entry) {
1444 dev_dbg(&qp->ndev->pdev->dev, "no receive buffer\n");
1445 qp->rx_err_no_buf++;
1446 return -EAGAIN;
1447 }
1448
1449 entry->rx_hdr = hdr;
1450 entry->rx_index = qp->rx_index;
1451
1452 if (hdr->len > entry->len) {
1453 dev_dbg(&qp->ndev->pdev->dev,
1454 "receive buffer overflow! Wanted %d got %d\n",
1455 hdr->len, entry->len);
1456 qp->rx_err_oflow++;
1457
1458 entry->len = -EIO;
1459 entry->flags |= DESC_DONE_FLAG;
1460
1461 ntb_complete_rxc(qp);
1462 } else {
1463 dev_dbg(&qp->ndev->pdev->dev,
1464 "RX OK index %u ver %u size %d into buf size %d\n",
1465 qp->rx_index, hdr->ver, hdr->len, entry->len);
1466
1467 qp->rx_bytes += hdr->len;
1468 qp->rx_pkts++;
1469
1470 entry->len = hdr->len;
1471
1472 ntb_async_rx(entry, offset);
1473 }
1474
1475 qp->rx_index++;
1476 qp->rx_index %= qp->rx_max_entry;
1477
1478 return 0;
1479 }
1480
1481 static void ntb_transport_rxc_db(unsigned long data)
1482 {
1483 struct ntb_transport_qp *qp = (void *)data;
1484 int rc, i;
1485
1486 dev_dbg(&qp->ndev->pdev->dev, "%s: doorbell %d received\n",
1487 __func__, qp->qp_num);
1488
1489 /* Limit the number of packets processed in a single interrupt to
1490 * provide fairness to others
1491 */
1492 for (i = 0; i < qp->rx_max_entry; i++) {
1493 rc = ntb_process_rxc(qp);
1494 if (rc)
1495 break;
1496 }
1497
1498 if (i && qp->rx_dma_chan)
1499 dma_async_issue_pending(qp->rx_dma_chan);
1500
1501 if (i == qp->rx_max_entry) {
1502 /* there is more work to do */
1503 if (qp->active)
1504 tasklet_schedule(&qp->rxc_db_work);
1505 } else if (ntb_db_read(qp->ndev) & BIT_ULL(qp->qp_num)) {
1506 /* the doorbell bit is set: clear it */
1507 ntb_db_clear(qp->ndev, BIT_ULL(qp->qp_num));
1508 /* ntb_db_read ensures ntb_db_clear write is committed */
1509 ntb_db_read(qp->ndev);
1510
1511 /* an interrupt may have arrived between finishing
1512 * ntb_process_rxc and clearing the doorbell bit:
1513 * there might be some more work to do.
1514 */
1515 if (qp->active)
1516 tasklet_schedule(&qp->rxc_db_work);
1517 }
1518 }
1519
1520 static void ntb_tx_copy_callback(void *data,
1521 const struct dmaengine_result *res)
1522 {
1523 struct ntb_queue_entry *entry = data;
1524 struct ntb_transport_qp *qp = entry->qp;
1525 struct ntb_payload_header __iomem *hdr = entry->tx_hdr;
1526
1527 /* we need to check DMA results if we are using DMA */
1528 if (res) {
1529 enum dmaengine_tx_result dma_err = res->result;
1530
1531 switch (dma_err) {
1532 case DMA_TRANS_READ_FAILED:
1533 case DMA_TRANS_WRITE_FAILED:
1534 entry->errors++;
1535 case DMA_TRANS_ABORTED:
1536 {
1537 void __iomem *offset =
1538 qp->tx_mw + qp->tx_max_frame *
1539 entry->tx_index;
1540
1541 /* resubmit via CPU */
1542 ntb_memcpy_tx(entry, offset);
1543 qp->tx_memcpy++;
1544 return;
1545 }
1546
1547 case DMA_TRANS_NOERROR:
1548 default:
1549 break;
1550 }
1551 }
1552
1553 iowrite32(entry->flags | DESC_DONE_FLAG, &hdr->flags);
1554
1555 ntb_peer_db_set(qp->ndev, BIT_ULL(qp->qp_num));
1556
1557 /* The entry length can only be zero if the packet is intended to be a
1558 * "link down" or similar. Since no payload is being sent in these
1559 * cases, there is nothing to add to the completion queue.
1560 */
1561 if (entry->len > 0) {
1562 qp->tx_bytes += entry->len;
1563
1564 if (qp->tx_handler)
1565 qp->tx_handler(qp, qp->cb_data, entry->cb_data,
1566 entry->len);
1567 }
1568
1569 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q);
1570 }
1571
1572 static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset)
1573 {
1574 #ifdef ARCH_HAS_NOCACHE_UACCESS
1575 /*
1576 * Using non-temporal mov to improve performance on non-cached
1577 * writes, even though we aren't actually copying from user space.
1578 */
1579 __copy_from_user_inatomic_nocache(offset, entry->buf, entry->len);
1580 #else
1581 memcpy_toio(offset, entry->buf, entry->len);
1582 #endif
1583
1584 /* Ensure that the data is fully copied out before setting the flags */
1585 wmb();
1586
1587 ntb_tx_copy_callback(entry, NULL);
1588 }
1589
1590 static int ntb_async_tx_submit(struct ntb_transport_qp *qp,
1591 struct ntb_queue_entry *entry)
1592 {
1593 struct dma_async_tx_descriptor *txd;
1594 struct dma_chan *chan = qp->tx_dma_chan;
1595 struct dma_device *device;
1596 size_t len = entry->len;
1597 void *buf = entry->buf;
1598 size_t dest_off, buff_off;
1599 struct dmaengine_unmap_data *unmap;
1600 dma_addr_t dest;
1601 dma_cookie_t cookie;
1602
1603 device = chan->device;
1604 dest = qp->tx_mw_phys + qp->tx_max_frame * entry->tx_index;
1605 buff_off = (size_t)buf & ~PAGE_MASK;
1606 dest_off = (size_t)dest & ~PAGE_MASK;
1607
1608 if (!is_dma_copy_aligned(device, buff_off, dest_off, len))
1609 goto err;
1610
1611 unmap = dmaengine_get_unmap_data(device->dev, 1, GFP_NOWAIT);
1612 if (!unmap)
1613 goto err;
1614
1615 unmap->len = len;
1616 unmap->addr[0] = dma_map_page(device->dev, virt_to_page(buf),
1617 buff_off, len, DMA_TO_DEVICE);
1618 if (dma_mapping_error(device->dev, unmap->addr[0]))
1619 goto err_get_unmap;
1620
1621 unmap->to_cnt = 1;
1622
1623 txd = device->device_prep_dma_memcpy(chan, dest, unmap->addr[0], len,
1624 DMA_PREP_INTERRUPT);
1625 if (!txd)
1626 goto err_get_unmap;
1627
1628 txd->callback_result = ntb_tx_copy_callback;
1629 txd->callback_param = entry;
1630 dma_set_unmap(txd, unmap);
1631
1632 cookie = dmaengine_submit(txd);
1633 if (dma_submit_error(cookie))
1634 goto err_set_unmap;
1635
1636 dmaengine_unmap_put(unmap);
1637
1638 dma_async_issue_pending(chan);
1639
1640 return 0;
1641 err_set_unmap:
1642 dmaengine_unmap_put(unmap);
1643 err_get_unmap:
1644 dmaengine_unmap_put(unmap);
1645 err:
1646 return -ENXIO;
1647 }
1648
1649 static void ntb_async_tx(struct ntb_transport_qp *qp,
1650 struct ntb_queue_entry *entry)
1651 {
1652 struct ntb_payload_header __iomem *hdr;
1653 struct dma_chan *chan = qp->tx_dma_chan;
1654 void __iomem *offset;
1655 int res;
1656
1657 entry->tx_index = qp->tx_index;
1658 offset = qp->tx_mw + qp->tx_max_frame * entry->tx_index;
1659 hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
1660 entry->tx_hdr = hdr;
1661
1662 iowrite32(entry->len, &hdr->len);
1663 iowrite32((u32)qp->tx_pkts, &hdr->ver);
1664
1665 if (!chan)
1666 goto err;
1667
1668 if (entry->len < copy_bytes)
1669 goto err;
1670
1671 res = ntb_async_tx_submit(qp, entry);
1672 if (res < 0)
1673 goto err;
1674
1675 if (!entry->retries)
1676 qp->tx_async++;
1677
1678 return;
1679
1680 err:
1681 ntb_memcpy_tx(entry, offset);
1682 qp->tx_memcpy++;
1683 }
1684
1685 static int ntb_process_tx(struct ntb_transport_qp *qp,
1686 struct ntb_queue_entry *entry)
1687 {
1688 if (qp->tx_index == qp->remote_rx_info->entry) {
1689 qp->tx_ring_full++;
1690 return -EAGAIN;
1691 }
1692
1693 if (entry->len > qp->tx_max_frame - sizeof(struct ntb_payload_header)) {
1694 if (qp->tx_handler)
1695 qp->tx_handler(qp, qp->cb_data, NULL, -EIO);
1696
1697 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1698 &qp->tx_free_q);
1699 return 0;
1700 }
1701
1702 ntb_async_tx(qp, entry);
1703
1704 qp->tx_index++;
1705 qp->tx_index %= qp->tx_max_entry;
1706
1707 qp->tx_pkts++;
1708
1709 return 0;
1710 }
1711
1712 static void ntb_send_link_down(struct ntb_transport_qp *qp)
1713 {
1714 struct pci_dev *pdev = qp->ndev->pdev;
1715 struct ntb_queue_entry *entry;
1716 int i, rc;
1717
1718 if (!qp->link_is_up)
1719 return;
1720
1721 dev_info(&pdev->dev, "qp %d: Send Link Down\n", qp->qp_num);
1722
1723 for (i = 0; i < NTB_LINK_DOWN_TIMEOUT; i++) {
1724 entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1725 if (entry)
1726 break;
1727 msleep(100);
1728 }
1729
1730 if (!entry)
1731 return;
1732
1733 entry->cb_data = NULL;
1734 entry->buf = NULL;
1735 entry->len = 0;
1736 entry->flags = LINK_DOWN_FLAG;
1737
1738 rc = ntb_process_tx(qp, entry);
1739 if (rc)
1740 dev_err(&pdev->dev, "ntb: QP%d unable to send linkdown msg\n",
1741 qp->qp_num);
1742
1743 ntb_qp_link_down_reset(qp);
1744 }
1745
1746 static bool ntb_dma_filter_fn(struct dma_chan *chan, void *node)
1747 {
1748 return dev_to_node(&chan->dev->device) == (int)(unsigned long)node;
1749 }
1750
1751 /**
1752 * ntb_transport_create_queue - Create a new NTB transport layer queue
1753 * @rx_handler: receive callback function
1754 * @tx_handler: transmit callback function
1755 * @event_handler: event callback function
1756 *
1757 * Create a new NTB transport layer queue and provide the queue with a callback
1758 * routine for both transmit and receive. The receive callback routine will be
1759 * used to pass up data when the transport has received it on the queue. The
1760 * transmit callback routine will be called when the transport has completed the
1761 * transmission of the data on the queue and the data is ready to be freed.
1762 *
1763 * RETURNS: pointer to newly created ntb_queue, NULL on error.
1764 */
1765 struct ntb_transport_qp *
1766 ntb_transport_create_queue(void *data, struct device *client_dev,
1767 const struct ntb_queue_handlers *handlers)
1768 {
1769 struct ntb_dev *ndev;
1770 struct pci_dev *pdev;
1771 struct ntb_transport_ctx *nt;
1772 struct ntb_queue_entry *entry;
1773 struct ntb_transport_qp *qp;
1774 u64 qp_bit;
1775 unsigned int free_queue;
1776 dma_cap_mask_t dma_mask;
1777 int node;
1778 int i;
1779
1780 ndev = dev_ntb(client_dev->parent);
1781 pdev = ndev->pdev;
1782 nt = ndev->ctx;
1783
1784 node = dev_to_node(&ndev->dev);
1785
1786 free_queue = ffs(nt->qp_bitmap_free);
1787 if (!free_queue)
1788 goto err;
1789
1790 /* decrement free_queue to make it zero based */
1791 free_queue--;
1792
1793 qp = &nt->qp_vec[free_queue];
1794 qp_bit = BIT_ULL(qp->qp_num);
1795
1796 nt->qp_bitmap_free &= ~qp_bit;
1797
1798 qp->cb_data = data;
1799 qp->rx_handler = handlers->rx_handler;
1800 qp->tx_handler = handlers->tx_handler;
1801 qp->event_handler = handlers->event_handler;
1802
1803 dma_cap_zero(dma_mask);
1804 dma_cap_set(DMA_MEMCPY, dma_mask);
1805
1806 if (use_dma) {
1807 qp->tx_dma_chan =
1808 dma_request_channel(dma_mask, ntb_dma_filter_fn,
1809 (void *)(unsigned long)node);
1810 if (!qp->tx_dma_chan)
1811 dev_info(&pdev->dev, "Unable to allocate TX DMA channel\n");
1812
1813 qp->rx_dma_chan =
1814 dma_request_channel(dma_mask, ntb_dma_filter_fn,
1815 (void *)(unsigned long)node);
1816 if (!qp->rx_dma_chan)
1817 dev_info(&pdev->dev, "Unable to allocate RX DMA channel\n");
1818 } else {
1819 qp->tx_dma_chan = NULL;
1820 qp->rx_dma_chan = NULL;
1821 }
1822
1823 dev_dbg(&pdev->dev, "Using %s memcpy for TX\n",
1824 qp->tx_dma_chan ? "DMA" : "CPU");
1825
1826 dev_dbg(&pdev->dev, "Using %s memcpy for RX\n",
1827 qp->rx_dma_chan ? "DMA" : "CPU");
1828
1829 for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
1830 entry = kzalloc_node(sizeof(*entry), GFP_ATOMIC, node);
1831 if (!entry)
1832 goto err1;
1833
1834 entry->qp = qp;
1835 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry,
1836 &qp->rx_free_q);
1837 }
1838 qp->rx_alloc_entry = NTB_QP_DEF_NUM_ENTRIES;
1839
1840 for (i = 0; i < qp->tx_max_entry; i++) {
1841 entry = kzalloc_node(sizeof(*entry), GFP_ATOMIC, node);
1842 if (!entry)
1843 goto err2;
1844
1845 entry->qp = qp;
1846 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1847 &qp->tx_free_q);
1848 }
1849
1850 ntb_db_clear(qp->ndev, qp_bit);
1851 ntb_db_clear_mask(qp->ndev, qp_bit);
1852
1853 dev_info(&pdev->dev, "NTB Transport QP %d created\n", qp->qp_num);
1854
1855 return qp;
1856
1857 err2:
1858 while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1859 kfree(entry);
1860 err1:
1861 qp->rx_alloc_entry = 0;
1862 while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
1863 kfree(entry);
1864 if (qp->tx_dma_chan)
1865 dma_release_channel(qp->tx_dma_chan);
1866 if (qp->rx_dma_chan)
1867 dma_release_channel(qp->rx_dma_chan);
1868 nt->qp_bitmap_free |= qp_bit;
1869 err:
1870 return NULL;
1871 }
1872 EXPORT_SYMBOL_GPL(ntb_transport_create_queue);
1873
1874 /**
1875 * ntb_transport_free_queue - Frees NTB transport queue
1876 * @qp: NTB queue to be freed
1877 *
1878 * Frees NTB transport queue
1879 */
1880 void ntb_transport_free_queue(struct ntb_transport_qp *qp)
1881 {
1882 struct pci_dev *pdev;
1883 struct ntb_queue_entry *entry;
1884 u64 qp_bit;
1885
1886 if (!qp)
1887 return;
1888
1889 pdev = qp->ndev->pdev;
1890
1891 qp->active = false;
1892
1893 if (qp->tx_dma_chan) {
1894 struct dma_chan *chan = qp->tx_dma_chan;
1895 /* Putting the dma_chan to NULL will force any new traffic to be
1896 * processed by the CPU instead of the DAM engine
1897 */
1898 qp->tx_dma_chan = NULL;
1899
1900 /* Try to be nice and wait for any queued DMA engine
1901 * transactions to process before smashing it with a rock
1902 */
1903 dma_sync_wait(chan, qp->last_cookie);
1904 dmaengine_terminate_all(chan);
1905 dma_release_channel(chan);
1906 }
1907
1908 if (qp->rx_dma_chan) {
1909 struct dma_chan *chan = qp->rx_dma_chan;
1910 /* Putting the dma_chan to NULL will force any new traffic to be
1911 * processed by the CPU instead of the DAM engine
1912 */
1913 qp->rx_dma_chan = NULL;
1914
1915 /* Try to be nice and wait for any queued DMA engine
1916 * transactions to process before smashing it with a rock
1917 */
1918 dma_sync_wait(chan, qp->last_cookie);
1919 dmaengine_terminate_all(chan);
1920 dma_release_channel(chan);
1921 }
1922
1923 qp_bit = BIT_ULL(qp->qp_num);
1924
1925 ntb_db_set_mask(qp->ndev, qp_bit);
1926 tasklet_kill(&qp->rxc_db_work);
1927
1928 cancel_delayed_work_sync(&qp->link_work);
1929
1930 qp->cb_data = NULL;
1931 qp->rx_handler = NULL;
1932 qp->tx_handler = NULL;
1933 qp->event_handler = NULL;
1934
1935 while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
1936 kfree(entry);
1937
1938 while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_pend_q))) {
1939 dev_warn(&pdev->dev, "Freeing item from non-empty rx_pend_q\n");
1940 kfree(entry);
1941 }
1942
1943 while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_post_q))) {
1944 dev_warn(&pdev->dev, "Freeing item from non-empty rx_post_q\n");
1945 kfree(entry);
1946 }
1947
1948 while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1949 kfree(entry);
1950
1951 qp->transport->qp_bitmap_free |= qp_bit;
1952
1953 dev_info(&pdev->dev, "NTB Transport QP %d freed\n", qp->qp_num);
1954 }
1955 EXPORT_SYMBOL_GPL(ntb_transport_free_queue);
1956
1957 /**
1958 * ntb_transport_rx_remove - Dequeues enqueued rx packet
1959 * @qp: NTB queue to be freed
1960 * @len: pointer to variable to write enqueued buffers length
1961 *
1962 * Dequeues unused buffers from receive queue. Should only be used during
1963 * shutdown of qp.
1964 *
1965 * RETURNS: NULL error value on error, or void* for success.
1966 */
1967 void *ntb_transport_rx_remove(struct ntb_transport_qp *qp, unsigned int *len)
1968 {
1969 struct ntb_queue_entry *entry;
1970 void *buf;
1971
1972 if (!qp || qp->client_ready)
1973 return NULL;
1974
1975 entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_pend_q);
1976 if (!entry)
1977 return NULL;
1978
1979 buf = entry->cb_data;
1980 *len = entry->len;
1981
1982 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_free_q);
1983
1984 return buf;
1985 }
1986 EXPORT_SYMBOL_GPL(ntb_transport_rx_remove);
1987
1988 /**
1989 * ntb_transport_rx_enqueue - Enqueue a new NTB queue entry
1990 * @qp: NTB transport layer queue the entry is to be enqueued on
1991 * @cb: per buffer pointer for callback function to use
1992 * @data: pointer to data buffer that incoming packets will be copied into
1993 * @len: length of the data buffer
1994 *
1995 * Enqueue a new receive buffer onto the transport queue into which a NTB
1996 * payload can be received into.
1997 *
1998 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
1999 */
2000 int ntb_transport_rx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
2001 unsigned int len)
2002 {
2003 struct ntb_queue_entry *entry;
2004
2005 if (!qp)
2006 return -EINVAL;
2007
2008 entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q);
2009 if (!entry)
2010 return -ENOMEM;
2011
2012 entry->cb_data = cb;
2013 entry->buf = data;
2014 entry->len = len;
2015 entry->flags = 0;
2016 entry->retries = 0;
2017 entry->errors = 0;
2018 entry->rx_index = 0;
2019
2020 ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_pend_q);
2021
2022 if (qp->active)
2023 tasklet_schedule(&qp->rxc_db_work);
2024
2025 return 0;
2026 }
2027 EXPORT_SYMBOL_GPL(ntb_transport_rx_enqueue);
2028
2029 /**
2030 * ntb_transport_tx_enqueue - Enqueue a new NTB queue entry
2031 * @qp: NTB transport layer queue the entry is to be enqueued on
2032 * @cb: per buffer pointer for callback function to use
2033 * @data: pointer to data buffer that will be sent
2034 * @len: length of the data buffer
2035 *
2036 * Enqueue a new transmit buffer onto the transport queue from which a NTB
2037 * payload will be transmitted. This assumes that a lock is being held to
2038 * serialize access to the qp.
2039 *
2040 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
2041 */
2042 int ntb_transport_tx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
2043 unsigned int len)
2044 {
2045 struct ntb_queue_entry *entry;
2046 int rc;
2047
2048 if (!qp || !qp->link_is_up || !len)
2049 return -EINVAL;
2050
2051 entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
2052 if (!entry) {
2053 qp->tx_err_no_buf++;
2054 return -EBUSY;
2055 }
2056
2057 entry->cb_data = cb;
2058 entry->buf = data;
2059 entry->len = len;
2060 entry->flags = 0;
2061 entry->errors = 0;
2062 entry->retries = 0;
2063 entry->tx_index = 0;
2064
2065 rc = ntb_process_tx(qp, entry);
2066 if (rc)
2067 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
2068 &qp->tx_free_q);
2069
2070 return rc;
2071 }
2072 EXPORT_SYMBOL_GPL(ntb_transport_tx_enqueue);
2073
2074 /**
2075 * ntb_transport_link_up - Notify NTB transport of client readiness to use queue
2076 * @qp: NTB transport layer queue to be enabled
2077 *
2078 * Notify NTB transport layer of client readiness to use queue
2079 */
2080 void ntb_transport_link_up(struct ntb_transport_qp *qp)
2081 {
2082 if (!qp)
2083 return;
2084
2085 qp->client_ready = true;
2086
2087 if (qp->transport->link_is_up)
2088 schedule_delayed_work(&qp->link_work, 0);
2089 }
2090 EXPORT_SYMBOL_GPL(ntb_transport_link_up);
2091
2092 /**
2093 * ntb_transport_link_down - Notify NTB transport to no longer enqueue data
2094 * @qp: NTB transport layer queue to be disabled
2095 *
2096 * Notify NTB transport layer of client's desire to no longer receive data on
2097 * transport queue specified. It is the client's responsibility to ensure all
2098 * entries on queue are purged or otherwise handled appropriately.
2099 */
2100 void ntb_transport_link_down(struct ntb_transport_qp *qp)
2101 {
2102 int val;
2103
2104 if (!qp)
2105 return;
2106
2107 qp->client_ready = false;
2108
2109 val = ntb_spad_read(qp->ndev, QP_LINKS);
2110
2111 ntb_peer_spad_write(qp->ndev, PIDX, QP_LINKS, val & ~BIT(qp->qp_num));
2112
2113 if (qp->link_is_up)
2114 ntb_send_link_down(qp);
2115 else
2116 cancel_delayed_work_sync(&qp->link_work);
2117 }
2118 EXPORT_SYMBOL_GPL(ntb_transport_link_down);
2119
2120 /**
2121 * ntb_transport_link_query - Query transport link state
2122 * @qp: NTB transport layer queue to be queried
2123 *
2124 * Query connectivity to the remote system of the NTB transport queue
2125 *
2126 * RETURNS: true for link up or false for link down
2127 */
2128 bool ntb_transport_link_query(struct ntb_transport_qp *qp)
2129 {
2130 if (!qp)
2131 return false;
2132
2133 return qp->link_is_up;
2134 }
2135 EXPORT_SYMBOL_GPL(ntb_transport_link_query);
2136
2137 /**
2138 * ntb_transport_qp_num - Query the qp number
2139 * @qp: NTB transport layer queue to be queried
2140 *
2141 * Query qp number of the NTB transport queue
2142 *
2143 * RETURNS: a zero based number specifying the qp number
2144 */
2145 unsigned char ntb_transport_qp_num(struct ntb_transport_qp *qp)
2146 {
2147 if (!qp)
2148 return 0;
2149
2150 return qp->qp_num;
2151 }
2152 EXPORT_SYMBOL_GPL(ntb_transport_qp_num);
2153
2154 /**
2155 * ntb_transport_max_size - Query the max payload size of a qp
2156 * @qp: NTB transport layer queue to be queried
2157 *
2158 * Query the maximum payload size permissible on the given qp
2159 *
2160 * RETURNS: the max payload size of a qp
2161 */
2162 unsigned int ntb_transport_max_size(struct ntb_transport_qp *qp)
2163 {
2164 unsigned int max_size;
2165 unsigned int copy_align;
2166 struct dma_chan *rx_chan, *tx_chan;
2167
2168 if (!qp)
2169 return 0;
2170
2171 rx_chan = qp->rx_dma_chan;
2172 tx_chan = qp->tx_dma_chan;
2173
2174 copy_align = max(rx_chan ? rx_chan->device->copy_align : 0,
2175 tx_chan ? tx_chan->device->copy_align : 0);
2176
2177 /* If DMA engine usage is possible, try to find the max size for that */
2178 max_size = qp->tx_max_frame - sizeof(struct ntb_payload_header);
2179 max_size = round_down(max_size, 1 << copy_align);
2180
2181 return max_size;
2182 }
2183 EXPORT_SYMBOL_GPL(ntb_transport_max_size);
2184
2185 unsigned int ntb_transport_tx_free_entry(struct ntb_transport_qp *qp)
2186 {
2187 unsigned int head = qp->tx_index;
2188 unsigned int tail = qp->remote_rx_info->entry;
2189
2190 return tail > head ? tail - head : qp->tx_max_entry + tail - head;
2191 }
2192 EXPORT_SYMBOL_GPL(ntb_transport_tx_free_entry);
2193
2194 static void ntb_transport_doorbell_callback(void *data, int vector)
2195 {
2196 struct ntb_transport_ctx *nt = data;
2197 struct ntb_transport_qp *qp;
2198 u64 db_bits;
2199 unsigned int qp_num;
2200
2201 db_bits = (nt->qp_bitmap & ~nt->qp_bitmap_free &
2202 ntb_db_vector_mask(nt->ndev, vector));
2203
2204 while (db_bits) {
2205 qp_num = __ffs(db_bits);
2206 qp = &nt->qp_vec[qp_num];
2207
2208 if (qp->active)
2209 tasklet_schedule(&qp->rxc_db_work);
2210
2211 db_bits &= ~BIT_ULL(qp_num);
2212 }
2213 }
2214
2215 static const struct ntb_ctx_ops ntb_transport_ops = {
2216 .link_event = ntb_transport_event_callback,
2217 .db_event = ntb_transport_doorbell_callback,
2218 };
2219
2220 static struct ntb_client ntb_transport_client = {
2221 .ops = {
2222 .probe = ntb_transport_probe,
2223 .remove = ntb_transport_free,
2224 },
2225 };
2226
2227 static int __init ntb_transport_init(void)
2228 {
2229 int rc;
2230
2231 pr_info("%s, version %s\n", NTB_TRANSPORT_DESC, NTB_TRANSPORT_VER);
2232
2233 if (debugfs_initialized())
2234 nt_debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
2235
2236 rc = bus_register(&ntb_transport_bus);
2237 if (rc)
2238 goto err_bus;
2239
2240 rc = ntb_register_client(&ntb_transport_client);
2241 if (rc)
2242 goto err_client;
2243
2244 return 0;
2245
2246 err_client:
2247 bus_unregister(&ntb_transport_bus);
2248 err_bus:
2249 debugfs_remove_recursive(nt_debugfs_dir);
2250 return rc;
2251 }
2252 module_init(ntb_transport_init);
2253
2254 static void __exit ntb_transport_exit(void)
2255 {
2256 ntb_unregister_client(&ntb_transport_client);
2257 bus_unregister(&ntb_transport_bus);
2258 debugfs_remove_recursive(nt_debugfs_dir);
2259 }
2260 module_exit(ntb_transport_exit);
CRIS linux kernel tree