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.
7 * Copyright(c) 2012 Intel Corporation. All rights reserved.
8 * Copyright (C) 2015 EMC Corporation. All Rights Reserved.
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.
16 * Copyright(c) 2012 Intel Corporation. All rights reserved.
17 * Copyright (C) 2015 EMC Corporation. All Rights Reserved.
19 * Redistribution and use in source and binary forms, with or without
20 * modification, are permitted provided that the following conditions
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
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.
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.
45 * PCIe NTB Transport Linux driver
47 * Contact Information:
48 * Jon Mason <jon.mason@intel.com>
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/ntb.h"
62 #include "linux/ntb_transport.h"
64 #define NTB_TRANSPORT_VERSION 4
65 #define NTB_TRANSPORT_VER "4"
66 #define NTB_TRANSPORT_NAME "ntb_transport"
67 #define NTB_TRANSPORT_DESC "Software Queue-Pair Transport over NTB"
69 MODULE_DESCRIPTION(NTB_TRANSPORT_DESC);
70 MODULE_VERSION(NTB_TRANSPORT_VER);
71 MODULE_LICENSE("Dual BSD/GPL");
72 MODULE_AUTHOR("Intel Corporation");
74 static unsigned long max_mw_size;
75 module_param(max_mw_size, ulong, 0644);
76 MODULE_PARM_DESC(max_mw_size, "Limit size of large memory windows");
78 static unsigned int transport_mtu = 0x401E;
79 module_param(transport_mtu, uint, 0644);
80 MODULE_PARM_DESC(transport_mtu, "Maximum size of NTB transport packets");
82 static unsigned char max_num_clients;
83 module_param(max_num_clients, byte, 0644);
84 MODULE_PARM_DESC(max_num_clients, "Maximum number of NTB transport clients");
86 static unsigned int copy_bytes = 1024;
87 module_param(copy_bytes, uint, 0644);
88 MODULE_PARM_DESC(copy_bytes, "Threshold under which NTB will use the CPU to copy instead of DMA");
90 static struct dentry *nt_debugfs_dir;
92 struct ntb_queue_entry {
93 /* ntb_queue list reference */
94 struct list_head entry;
95 /* pointers to data to be transferred */
101 struct ntb_transport_qp *qp;
103 struct ntb_payload_header __iomem *tx_hdr;
104 struct ntb_payload_header *rx_hdr;
113 struct ntb_transport_qp {
114 struct ntb_transport_ctx *transport;
115 struct ntb_dev *ndev;
117 struct dma_chan *dma_chan;
122 u8 qp_num; /* Only 64 QP's are allowed. 0-63 */
125 struct ntb_rx_info __iomem *rx_info;
126 struct ntb_rx_info *remote_rx_info;
128 void (*tx_handler)(struct ntb_transport_qp *qp, void *qp_data,
129 void *data, int len);
130 struct list_head tx_free_q;
131 spinlock_t ntb_tx_free_q_lock;
133 dma_addr_t tx_mw_phys;
134 unsigned int tx_index;
135 unsigned int tx_max_entry;
136 unsigned int tx_max_frame;
138 void (*rx_handler)(struct ntb_transport_qp *qp, void *qp_data,
139 void *data, int len);
140 struct list_head rx_pend_q;
141 struct list_head rx_free_q;
142 spinlock_t ntb_rx_pend_q_lock;
143 spinlock_t ntb_rx_free_q_lock;
145 unsigned int rx_index;
146 unsigned int rx_max_entry;
147 unsigned int rx_max_frame;
148 dma_cookie_t last_cookie;
149 struct tasklet_struct rxc_db_work;
151 void (*event_handler)(void *data, int status);
152 struct delayed_work link_work;
153 struct work_struct link_cleanup;
155 struct dentry *debugfs_dir;
156 struct dentry *debugfs_stats;
175 struct ntb_transport_mw {
176 phys_addr_t phys_addr;
177 resource_size_t phys_size;
178 resource_size_t xlat_align;
179 resource_size_t xlat_align_size;
187 struct ntb_transport_client_dev {
188 struct list_head entry;
189 struct ntb_transport_ctx *nt;
193 struct ntb_transport_ctx {
194 struct list_head entry;
195 struct list_head client_devs;
197 struct ntb_dev *ndev;
199 struct ntb_transport_mw *mw_vec;
200 struct ntb_transport_qp *qp_vec;
201 unsigned int mw_count;
202 unsigned int qp_count;
207 struct delayed_work link_work;
208 struct work_struct link_cleanup;
212 DESC_DONE_FLAG = BIT(0),
213 LINK_DOWN_FLAG = BIT(1),
216 struct ntb_payload_header {
234 #define dev_client_dev(__dev) \
235 container_of((__dev), struct ntb_transport_client_dev, dev)
237 #define drv_client(__drv) \
238 container_of((__drv), struct ntb_transport_client, driver)
240 #define QP_TO_MW(nt, qp) ((qp) % nt->mw_count)
241 #define NTB_QP_DEF_NUM_ENTRIES 100
242 #define NTB_LINK_DOWN_TIMEOUT 10
244 static void ntb_transport_rxc_db(unsigned long data);
245 static const struct ntb_ctx_ops ntb_transport_ops;
246 static struct ntb_client ntb_transport_client;
248 static int ntb_transport_bus_match(struct device *dev,
249 struct device_driver *drv)
251 return !strncmp(dev_name(dev), drv->name, strlen(drv->name));
254 static int ntb_transport_bus_probe(struct device *dev)
256 const struct ntb_transport_client *client;
261 client = drv_client(dev->driver);
262 rc = client->probe(dev);
269 static int ntb_transport_bus_remove(struct device *dev)
271 const struct ntb_transport_client *client;
273 client = drv_client(dev->driver);
281 static struct bus_type ntb_transport_bus = {
282 .name = "ntb_transport",
283 .match = ntb_transport_bus_match,
284 .probe = ntb_transport_bus_probe,
285 .remove = ntb_transport_bus_remove,
288 static LIST_HEAD(ntb_transport_list);
290 static int ntb_bus_init(struct ntb_transport_ctx *nt)
292 list_add(&nt->entry, &ntb_transport_list);
296 static void ntb_bus_remove(struct ntb_transport_ctx *nt)
298 struct ntb_transport_client_dev *client_dev, *cd;
300 list_for_each_entry_safe(client_dev, cd, &nt->client_devs, entry) {
301 dev_err(client_dev->dev.parent, "%s still attached to bus, removing\n",
302 dev_name(&client_dev->dev));
303 list_del(&client_dev->entry);
304 device_unregister(&client_dev->dev);
307 list_del(&nt->entry);
310 static void ntb_transport_client_release(struct device *dev)
312 struct ntb_transport_client_dev *client_dev;
314 client_dev = dev_client_dev(dev);
319 * ntb_transport_unregister_client_dev - Unregister NTB client device
320 * @device_name: Name of NTB client device
322 * Unregister an NTB client device with the NTB transport layer
324 void ntb_transport_unregister_client_dev(char *device_name)
326 struct ntb_transport_client_dev *client, *cd;
327 struct ntb_transport_ctx *nt;
329 list_for_each_entry(nt, &ntb_transport_list, entry)
330 list_for_each_entry_safe(client, cd, &nt->client_devs, entry)
331 if (!strncmp(dev_name(&client->dev), device_name,
332 strlen(device_name))) {
333 list_del(&client->entry);
334 device_unregister(&client->dev);
337 EXPORT_SYMBOL_GPL(ntb_transport_unregister_client_dev);
340 * ntb_transport_register_client_dev - Register NTB client device
341 * @device_name: Name of NTB client device
343 * Register an NTB client device with the NTB transport layer
345 int ntb_transport_register_client_dev(char *device_name)
347 struct ntb_transport_client_dev *client_dev;
348 struct ntb_transport_ctx *nt;
351 if (list_empty(&ntb_transport_list))
354 list_for_each_entry(nt, &ntb_transport_list, entry) {
357 client_dev = kzalloc(sizeof(*client_dev),
364 dev = &client_dev->dev;
366 /* setup and register client devices */
367 dev_set_name(dev, "%s%d", device_name, i);
368 dev->bus = &ntb_transport_bus;
369 dev->release = ntb_transport_client_release;
370 dev->parent = &nt->ndev->dev;
372 rc = device_register(dev);
378 list_add_tail(&client_dev->entry, &nt->client_devs);
385 ntb_transport_unregister_client_dev(device_name);
389 EXPORT_SYMBOL_GPL(ntb_transport_register_client_dev);
392 * ntb_transport_register_client - Register NTB client driver
393 * @drv: NTB client driver to be registered
395 * Register an NTB client driver with the NTB transport layer
397 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
399 int ntb_transport_register_client(struct ntb_transport_client *drv)
401 drv->driver.bus = &ntb_transport_bus;
403 if (list_empty(&ntb_transport_list))
406 return driver_register(&drv->driver);
408 EXPORT_SYMBOL_GPL(ntb_transport_register_client);
411 * ntb_transport_unregister_client - Unregister NTB client driver
412 * @drv: NTB client driver to be unregistered
414 * Unregister an NTB client driver with the NTB transport layer
416 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
418 void ntb_transport_unregister_client(struct ntb_transport_client *drv)
420 driver_unregister(&drv->driver);
422 EXPORT_SYMBOL_GPL(ntb_transport_unregister_client);
424 static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count,
427 struct ntb_transport_qp *qp;
429 ssize_t ret, out_offset, out_count;
433 buf = kmalloc(out_count, GFP_KERNEL);
437 qp = filp->private_data;
439 out_offset += snprintf(buf + out_offset, out_count - out_offset,
441 out_offset += snprintf(buf + out_offset, out_count - out_offset,
442 "rx_bytes - \t%llu\n", qp->rx_bytes);
443 out_offset += snprintf(buf + out_offset, out_count - out_offset,
444 "rx_pkts - \t%llu\n", qp->rx_pkts);
445 out_offset += snprintf(buf + out_offset, out_count - out_offset,
446 "rx_memcpy - \t%llu\n", qp->rx_memcpy);
447 out_offset += snprintf(buf + out_offset, out_count - out_offset,
448 "rx_async - \t%llu\n", qp->rx_async);
449 out_offset += snprintf(buf + out_offset, out_count - out_offset,
450 "rx_ring_empty - %llu\n", qp->rx_ring_empty);
451 out_offset += snprintf(buf + out_offset, out_count - out_offset,
452 "rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
453 out_offset += snprintf(buf + out_offset, out_count - out_offset,
454 "rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
455 out_offset += snprintf(buf + out_offset, out_count - out_offset,
456 "rx_err_ver - \t%llu\n", qp->rx_err_ver);
457 out_offset += snprintf(buf + out_offset, out_count - out_offset,
458 "rx_buff - \t%p\n", qp->rx_buff);
459 out_offset += snprintf(buf + out_offset, out_count - out_offset,
460 "rx_index - \t%u\n", qp->rx_index);
461 out_offset += snprintf(buf + out_offset, out_count - out_offset,
462 "rx_max_entry - \t%u\n", qp->rx_max_entry);
464 out_offset += snprintf(buf + out_offset, out_count - out_offset,
465 "tx_bytes - \t%llu\n", qp->tx_bytes);
466 out_offset += snprintf(buf + out_offset, out_count - out_offset,
467 "tx_pkts - \t%llu\n", qp->tx_pkts);
468 out_offset += snprintf(buf + out_offset, out_count - out_offset,
469 "tx_memcpy - \t%llu\n", qp->tx_memcpy);
470 out_offset += snprintf(buf + out_offset, out_count - out_offset,
471 "tx_async - \t%llu\n", qp->tx_async);
472 out_offset += snprintf(buf + out_offset, out_count - out_offset,
473 "tx_ring_full - \t%llu\n", qp->tx_ring_full);
474 out_offset += snprintf(buf + out_offset, out_count - out_offset,
475 "tx_err_no_buf - %llu\n", qp->tx_err_no_buf);
476 out_offset += snprintf(buf + out_offset, out_count - out_offset,
477 "tx_mw - \t%p\n", qp->tx_mw);
478 out_offset += snprintf(buf + out_offset, out_count - out_offset,
479 "tx_index - \t%u\n", qp->tx_index);
480 out_offset += snprintf(buf + out_offset, out_count - out_offset,
481 "tx_max_entry - \t%u\n", qp->tx_max_entry);
483 out_offset += snprintf(buf + out_offset, out_count - out_offset,
485 qp->link_is_up ? "Up" : "Down");
486 if (out_offset > out_count)
487 out_offset = out_count;
489 ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
494 static const struct file_operations ntb_qp_debugfs_stats = {
495 .owner = THIS_MODULE,
497 .read = debugfs_read,
500 static void ntb_list_add(spinlock_t *lock, struct list_head *entry,
501 struct list_head *list)
505 spin_lock_irqsave(lock, flags);
506 list_add_tail(entry, list);
507 spin_unlock_irqrestore(lock, flags);
510 static struct ntb_queue_entry *ntb_list_rm(spinlock_t *lock,
511 struct list_head *list)
513 struct ntb_queue_entry *entry;
516 spin_lock_irqsave(lock, flags);
517 if (list_empty(list)) {
521 entry = list_first_entry(list, struct ntb_queue_entry, entry);
522 list_del(&entry->entry);
524 spin_unlock_irqrestore(lock, flags);
529 static int ntb_transport_setup_qp_mw(struct ntb_transport_ctx *nt,
532 struct ntb_transport_qp *qp = &nt->qp_vec[qp_num];
533 struct ntb_transport_mw *mw;
534 unsigned int rx_size, num_qps_mw;
535 unsigned int mw_num, mw_count, qp_count;
538 mw_count = nt->mw_count;
539 qp_count = nt->qp_count;
541 mw_num = QP_TO_MW(nt, qp_num);
542 mw = &nt->mw_vec[mw_num];
547 if (qp_count % mw_count && mw_num + 1 < qp_count / mw_count)
548 num_qps_mw = qp_count / mw_count + 1;
550 num_qps_mw = qp_count / mw_count;
552 rx_size = (unsigned int)mw->xlat_size / num_qps_mw;
553 qp->rx_buff = mw->virt_addr + rx_size * qp_num / mw_count;
554 rx_size -= sizeof(struct ntb_rx_info);
556 qp->remote_rx_info = qp->rx_buff + rx_size;
558 /* Due to housekeeping, there must be atleast 2 buffs */
559 qp->rx_max_frame = min(transport_mtu, rx_size / 2);
560 qp->rx_max_entry = rx_size / qp->rx_max_frame;
563 qp->remote_rx_info->entry = qp->rx_max_entry - 1;
565 /* setup the hdr offsets with 0's */
566 for (i = 0; i < qp->rx_max_entry; i++) {
567 void *offset = (qp->rx_buff + qp->rx_max_frame * (i + 1) -
568 sizeof(struct ntb_payload_header));
569 memset(offset, 0, sizeof(struct ntb_payload_header));
579 static void ntb_free_mw(struct ntb_transport_ctx *nt, int num_mw)
581 struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
582 struct pci_dev *pdev = nt->ndev->pdev;
587 ntb_mw_clear_trans(nt->ndev, num_mw);
588 dma_free_coherent(&pdev->dev, mw->buff_size,
589 mw->virt_addr, mw->dma_addr);
592 mw->virt_addr = NULL;
595 static int ntb_set_mw(struct ntb_transport_ctx *nt, int num_mw,
598 struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
599 struct pci_dev *pdev = nt->ndev->pdev;
600 unsigned int xlat_size, buff_size;
603 xlat_size = round_up(size, mw->xlat_align_size);
604 buff_size = round_up(size, mw->xlat_align);
606 /* No need to re-setup */
607 if (mw->xlat_size == xlat_size)
611 ntb_free_mw(nt, num_mw);
613 /* Alloc memory for receiving data. Must be aligned */
614 mw->xlat_size = xlat_size;
615 mw->buff_size = buff_size;
617 mw->virt_addr = dma_alloc_coherent(&pdev->dev, buff_size,
618 &mw->dma_addr, GFP_KERNEL);
619 if (!mw->virt_addr) {
622 dev_err(&pdev->dev, "Unable to alloc MW buff of size %d\n",
628 * we must ensure that the memory address allocated is BAR size
629 * aligned in order for the XLAT register to take the value. This
630 * is a requirement of the hardware. It is recommended to setup CMA
631 * for BAR sizes equal or greater than 4MB.
633 if (!IS_ALIGNED(mw->dma_addr, mw->xlat_align)) {
634 dev_err(&pdev->dev, "DMA memory %pad is not aligned\n",
636 ntb_free_mw(nt, num_mw);
640 /* Notify HW the memory location of the receive buffer */
641 rc = ntb_mw_set_trans(nt->ndev, num_mw, mw->dma_addr, mw->xlat_size);
643 dev_err(&pdev->dev, "Unable to set mw%d translation", num_mw);
644 ntb_free_mw(nt, num_mw);
651 static void ntb_qp_link_down_reset(struct ntb_transport_qp *qp)
653 qp->link_is_up = false;
659 qp->rx_ring_empty = 0;
660 qp->rx_err_no_buf = 0;
661 qp->rx_err_oflow = 0;
667 qp->tx_ring_full = 0;
668 qp->tx_err_no_buf = 0;
673 static void ntb_qp_link_cleanup(struct ntb_transport_qp *qp)
675 struct ntb_transport_ctx *nt = qp->transport;
676 struct pci_dev *pdev = nt->ndev->pdev;
678 dev_info(&pdev->dev, "qp %d: Link Cleanup\n", qp->qp_num);
680 cancel_delayed_work_sync(&qp->link_work);
681 ntb_qp_link_down_reset(qp);
683 if (qp->event_handler)
684 qp->event_handler(qp->cb_data, qp->link_is_up);
687 static void ntb_qp_link_cleanup_work(struct work_struct *work)
689 struct ntb_transport_qp *qp = container_of(work,
690 struct ntb_transport_qp,
692 struct ntb_transport_ctx *nt = qp->transport;
694 ntb_qp_link_cleanup(qp);
697 schedule_delayed_work(&qp->link_work,
698 msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
701 static void ntb_qp_link_down(struct ntb_transport_qp *qp)
703 schedule_work(&qp->link_cleanup);
706 static void ntb_transport_link_cleanup(struct ntb_transport_ctx *nt)
708 struct ntb_transport_qp *qp;
712 qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
714 /* Pass along the info to any clients */
715 for (i = 0; i < nt->qp_count; i++)
716 if (qp_bitmap_alloc & BIT_ULL(i)) {
718 ntb_qp_link_cleanup(qp);
719 cancel_work_sync(&qp->link_cleanup);
720 cancel_delayed_work_sync(&qp->link_work);
724 cancel_delayed_work_sync(&nt->link_work);
726 /* The scratchpad registers keep the values if the remote side
727 * goes down, blast them now to give them a sane value the next
728 * time they are accessed
730 for (i = 0; i < MAX_SPAD; i++)
731 ntb_spad_write(nt->ndev, i, 0);
734 static void ntb_transport_link_cleanup_work(struct work_struct *work)
736 struct ntb_transport_ctx *nt =
737 container_of(work, struct ntb_transport_ctx, link_cleanup);
739 ntb_transport_link_cleanup(nt);
742 static void ntb_transport_event_callback(void *data)
744 struct ntb_transport_ctx *nt = data;
746 if (ntb_link_is_up(nt->ndev, NULL, NULL) == 1)
747 schedule_delayed_work(&nt->link_work, 0);
749 schedule_work(&nt->link_cleanup);
752 static void ntb_transport_link_work(struct work_struct *work)
754 struct ntb_transport_ctx *nt =
755 container_of(work, struct ntb_transport_ctx, link_work.work);
756 struct ntb_dev *ndev = nt->ndev;
757 struct pci_dev *pdev = ndev->pdev;
758 resource_size_t size;
762 /* send the local info, in the opposite order of the way we read it */
763 for (i = 0; i < nt->mw_count; i++) {
764 size = nt->mw_vec[i].phys_size;
766 if (max_mw_size && size > max_mw_size)
769 spad = MW0_SZ_HIGH + (i * 2);
770 ntb_peer_spad_write(ndev, spad, (u32)(size >> 32));
772 spad = MW0_SZ_LOW + (i * 2);
773 ntb_peer_spad_write(ndev, spad, (u32)size);
776 ntb_peer_spad_write(ndev, NUM_MWS, nt->mw_count);
778 ntb_peer_spad_write(ndev, NUM_QPS, nt->qp_count);
780 ntb_peer_spad_write(ndev, VERSION, NTB_TRANSPORT_VERSION);
782 /* Query the remote side for its info */
783 val = ntb_spad_read(ndev, VERSION);
784 dev_dbg(&pdev->dev, "Remote version = %d\n", val);
785 if (val != NTB_TRANSPORT_VERSION)
788 val = ntb_spad_read(ndev, NUM_QPS);
789 dev_dbg(&pdev->dev, "Remote max number of qps = %d\n", val);
790 if (val != nt->qp_count)
793 val = ntb_spad_read(ndev, NUM_MWS);
794 dev_dbg(&pdev->dev, "Remote number of mws = %d\n", val);
795 if (val != nt->mw_count)
798 for (i = 0; i < nt->mw_count; i++) {
801 val = ntb_spad_read(ndev, MW0_SZ_HIGH + (i * 2));
802 val64 = (u64)val << 32;
804 val = ntb_spad_read(ndev, MW0_SZ_LOW + (i * 2));
807 dev_dbg(&pdev->dev, "Remote MW%d size = %#llx\n", i, val64);
809 rc = ntb_set_mw(nt, i, val64);
814 nt->link_is_up = true;
816 for (i = 0; i < nt->qp_count; i++) {
817 struct ntb_transport_qp *qp = &nt->qp_vec[i];
819 ntb_transport_setup_qp_mw(nt, i);
821 if (qp->client_ready)
822 schedule_delayed_work(&qp->link_work, 0);
828 for (i = 0; i < nt->mw_count; i++)
831 if (ntb_link_is_up(ndev, NULL, NULL) == 1)
832 schedule_delayed_work(&nt->link_work,
833 msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
836 static void ntb_qp_link_work(struct work_struct *work)
838 struct ntb_transport_qp *qp = container_of(work,
839 struct ntb_transport_qp,
841 struct pci_dev *pdev = qp->ndev->pdev;
842 struct ntb_transport_ctx *nt = qp->transport;
845 WARN_ON(!nt->link_is_up);
847 val = ntb_spad_read(nt->ndev, QP_LINKS);
849 ntb_peer_spad_write(nt->ndev, QP_LINKS, val | BIT(qp->qp_num));
851 /* query remote spad for qp ready bits */
852 ntb_peer_spad_read(nt->ndev, QP_LINKS);
853 dev_dbg_ratelimited(&pdev->dev, "Remote QP link status = %x\n", val);
855 /* See if the remote side is up */
856 if (val & BIT(qp->qp_num)) {
857 dev_info(&pdev->dev, "qp %d: Link Up\n", qp->qp_num);
858 qp->link_is_up = true;
860 if (qp->event_handler)
861 qp->event_handler(qp->cb_data, qp->link_is_up);
862 } else if (nt->link_is_up)
863 schedule_delayed_work(&qp->link_work,
864 msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
867 static int ntb_transport_init_queue(struct ntb_transport_ctx *nt,
870 struct ntb_transport_qp *qp;
871 struct ntb_transport_mw *mw;
873 resource_size_t mw_size;
874 unsigned int num_qps_mw, tx_size;
875 unsigned int mw_num, mw_count, qp_count;
878 mw_count = nt->mw_count;
879 qp_count = nt->qp_count;
881 mw_num = QP_TO_MW(nt, qp_num);
882 mw = &nt->mw_vec[mw_num];
884 qp = &nt->qp_vec[qp_num];
888 qp->client_ready = false;
889 qp->event_handler = NULL;
890 ntb_qp_link_down_reset(qp);
892 if (qp_count % mw_count && mw_num + 1 < qp_count / mw_count)
893 num_qps_mw = qp_count / mw_count + 1;
895 num_qps_mw = qp_count / mw_count;
897 mw_base = nt->mw_vec[mw_num].phys_addr;
898 mw_size = nt->mw_vec[mw_num].phys_size;
900 tx_size = (unsigned int)mw_size / num_qps_mw;
901 qp_offset = tx_size * qp_num / mw_count;
903 qp->tx_mw = nt->mw_vec[mw_num].vbase + qp_offset;
907 qp->tx_mw_phys = mw_base + qp_offset;
911 tx_size -= sizeof(struct ntb_rx_info);
912 qp->rx_info = qp->tx_mw + tx_size;
914 /* Due to housekeeping, there must be atleast 2 buffs */
915 qp->tx_max_frame = min(transport_mtu, tx_size / 2);
916 qp->tx_max_entry = tx_size / qp->tx_max_frame;
918 if (nt_debugfs_dir) {
919 char debugfs_name[4];
921 snprintf(debugfs_name, 4, "qp%d", qp_num);
922 qp->debugfs_dir = debugfs_create_dir(debugfs_name,
925 qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR,
927 &ntb_qp_debugfs_stats);
929 qp->debugfs_dir = NULL;
930 qp->debugfs_stats = NULL;
933 INIT_DELAYED_WORK(&qp->link_work, ntb_qp_link_work);
934 INIT_WORK(&qp->link_cleanup, ntb_qp_link_cleanup_work);
936 spin_lock_init(&qp->ntb_rx_pend_q_lock);
937 spin_lock_init(&qp->ntb_rx_free_q_lock);
938 spin_lock_init(&qp->ntb_tx_free_q_lock);
940 INIT_LIST_HEAD(&qp->rx_pend_q);
941 INIT_LIST_HEAD(&qp->rx_free_q);
942 INIT_LIST_HEAD(&qp->tx_free_q);
944 tasklet_init(&qp->rxc_db_work, ntb_transport_rxc_db,
950 static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev)
952 struct ntb_transport_ctx *nt;
953 struct ntb_transport_mw *mw;
954 unsigned int mw_count, qp_count;
958 if (ntb_db_is_unsafe(ndev))
960 "doorbell is unsafe, proceed anyway...\n");
961 if (ntb_spad_is_unsafe(ndev))
963 "scratchpad is unsafe, proceed anyway...\n");
965 nt = kzalloc(sizeof(*nt), GFP_KERNEL);
971 mw_count = ntb_mw_count(ndev);
973 nt->mw_count = mw_count;
975 nt->mw_vec = kcalloc(mw_count, sizeof(*nt->mw_vec), GFP_KERNEL);
981 for (i = 0; i < mw_count; i++) {
984 rc = ntb_mw_get_range(ndev, i, &mw->phys_addr, &mw->phys_size,
985 &mw->xlat_align, &mw->xlat_align_size);
989 mw->vbase = ioremap(mw->phys_addr, mw->phys_size);
997 mw->virt_addr = NULL;
1001 qp_bitmap = ntb_db_valid_mask(ndev);
1003 qp_count = ilog2(qp_bitmap);
1004 if (max_num_clients && max_num_clients < qp_count)
1005 qp_count = max_num_clients;
1006 else if (mw_count < qp_count)
1007 qp_count = mw_count;
1009 qp_bitmap &= BIT_ULL(qp_count) - 1;
1011 nt->qp_count = qp_count;
1012 nt->qp_bitmap = qp_bitmap;
1013 nt->qp_bitmap_free = qp_bitmap;
1015 nt->qp_vec = kcalloc(qp_count, sizeof(*nt->qp_vec), GFP_KERNEL);
1021 for (i = 0; i < qp_count; i++) {
1022 rc = ntb_transport_init_queue(nt, i);
1027 INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work);
1028 INIT_WORK(&nt->link_cleanup, ntb_transport_link_cleanup_work);
1030 rc = ntb_set_ctx(ndev, nt, &ntb_transport_ops);
1034 INIT_LIST_HEAD(&nt->client_devs);
1035 rc = ntb_bus_init(nt);
1039 nt->link_is_up = false;
1040 ntb_link_enable(ndev, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
1041 ntb_link_event(ndev);
1046 ntb_clear_ctx(ndev);
1053 mw = &nt->mw_vec[i];
1061 static void ntb_transport_free(struct ntb_client *self, struct ntb_dev *ndev)
1063 struct ntb_transport_ctx *nt = ndev->ctx;
1064 struct ntb_transport_qp *qp;
1065 u64 qp_bitmap_alloc;
1068 ntb_transport_link_cleanup(nt);
1069 cancel_work_sync(&nt->link_cleanup);
1070 cancel_delayed_work_sync(&nt->link_work);
1072 qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
1074 /* verify that all the qp's are freed */
1075 for (i = 0; i < nt->qp_count; i++) {
1076 qp = &nt->qp_vec[i];
1077 if (qp_bitmap_alloc & BIT_ULL(i))
1078 ntb_transport_free_queue(qp);
1079 debugfs_remove_recursive(qp->debugfs_dir);
1082 ntb_link_disable(ndev);
1083 ntb_clear_ctx(ndev);
1087 for (i = nt->mw_count; i--; ) {
1089 iounmap(nt->mw_vec[i].vbase);
1097 static void ntb_rx_copy_callback(void *data)
1099 struct ntb_queue_entry *entry = data;
1100 struct ntb_transport_qp *qp = entry->qp;
1101 void *cb_data = entry->cb_data;
1102 unsigned int len = entry->len;
1103 struct ntb_payload_header *hdr = entry->rx_hdr;
1107 iowrite32(entry->index, &qp->rx_info->entry);
1109 ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry, &qp->rx_free_q);
1111 if (qp->rx_handler && qp->client_ready)
1112 qp->rx_handler(qp, qp->cb_data, cb_data, len);
1115 static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void *offset)
1117 void *buf = entry->buf;
1118 size_t len = entry->len;
1120 memcpy(buf, offset, len);
1122 /* Ensure that the data is fully copied out before clearing the flag */
1125 ntb_rx_copy_callback(entry);
1128 static void ntb_async_rx(struct ntb_queue_entry *entry, void *offset,
1131 struct dma_async_tx_descriptor *txd;
1132 struct ntb_transport_qp *qp = entry->qp;
1133 struct dma_chan *chan = qp->dma_chan;
1134 struct dma_device *device;
1135 size_t pay_off, buff_off;
1136 struct dmaengine_unmap_data *unmap;
1137 dma_cookie_t cookie;
1138 void *buf = entry->buf;
1145 if (len < copy_bytes)
1148 device = chan->device;
1149 pay_off = (size_t)offset & ~PAGE_MASK;
1150 buff_off = (size_t)buf & ~PAGE_MASK;
1152 if (!is_dma_copy_aligned(device, pay_off, buff_off, len))
1155 unmap = dmaengine_get_unmap_data(device->dev, 2, GFP_NOWAIT);
1160 unmap->addr[0] = dma_map_page(device->dev, virt_to_page(offset),
1161 pay_off, len, DMA_TO_DEVICE);
1162 if (dma_mapping_error(device->dev, unmap->addr[0]))
1167 unmap->addr[1] = dma_map_page(device->dev, virt_to_page(buf),
1168 buff_off, len, DMA_FROM_DEVICE);
1169 if (dma_mapping_error(device->dev, unmap->addr[1]))
1172 unmap->from_cnt = 1;
1174 txd = device->device_prep_dma_memcpy(chan, unmap->addr[1],
1175 unmap->addr[0], len,
1176 DMA_PREP_INTERRUPT);
1180 txd->callback = ntb_rx_copy_callback;
1181 txd->callback_param = entry;
1182 dma_set_unmap(txd, unmap);
1184 cookie = dmaengine_submit(txd);
1185 if (dma_submit_error(cookie))
1188 dmaengine_unmap_put(unmap);
1190 qp->last_cookie = cookie;
1197 dmaengine_unmap_put(unmap);
1199 dmaengine_unmap_put(unmap);
1201 /* If the callbacks come out of order, the writing of the index to the
1202 * last completed will be out of order. This may result in the
1203 * receive stalling forever.
1205 dma_sync_wait(chan, qp->last_cookie);
1207 ntb_memcpy_rx(entry, offset);
1211 static int ntb_process_rxc(struct ntb_transport_qp *qp)
1213 struct ntb_payload_header *hdr;
1214 struct ntb_queue_entry *entry;
1218 offset = qp->rx_buff + qp->rx_max_frame * qp->rx_index;
1219 hdr = offset + qp->rx_max_frame - sizeof(struct ntb_payload_header);
1221 dev_dbg(&qp->ndev->pdev->dev, "qp %d: RX ver %u len %d flags %x\n",
1222 qp->qp_num, hdr->ver, hdr->len, hdr->flags);
1224 if (!(hdr->flags & DESC_DONE_FLAG)) {
1225 dev_dbg(&qp->ndev->pdev->dev, "done flag not set\n");
1226 qp->rx_ring_empty++;
1230 if (hdr->flags & LINK_DOWN_FLAG) {
1231 dev_dbg(&qp->ndev->pdev->dev, "link down flag set\n");
1232 ntb_qp_link_down(qp);
1237 if (hdr->ver != (u32)qp->rx_pkts) {
1238 dev_dbg(&qp->ndev->pdev->dev,
1239 "version mismatch, expected %llu - got %u\n",
1240 qp->rx_pkts, hdr->ver);
1245 entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q);
1247 dev_dbg(&qp->ndev->pdev->dev, "no receive buffer\n");
1248 qp->rx_err_no_buf++;
1254 if (hdr->len > entry->len) {
1255 dev_dbg(&qp->ndev->pdev->dev,
1256 "receive buffer overflow! Wanted %d got %d\n",
1257 hdr->len, entry->len);
1264 dev_dbg(&qp->ndev->pdev->dev,
1265 "RX OK index %u ver %u size %d into buf size %d\n",
1266 qp->rx_index, hdr->ver, hdr->len, entry->len);
1268 qp->rx_bytes += hdr->len;
1271 entry->index = qp->rx_index;
1272 entry->rx_hdr = hdr;
1274 ntb_async_rx(entry, offset, hdr->len);
1277 qp->rx_index %= qp->rx_max_entry;
1282 /* FIXME: if this syncrhonous update of the rx_index gets ahead of
1283 * asyncrhonous ntb_rx_copy_callback of previous entry, there are three
1286 * 1) The peer might miss this update, but observe the update
1287 * from the memcpy completion callback. In this case, the buffer will
1288 * not be freed on the peer to be reused for a different packet. The
1289 * successful rx of a later packet would clear the condition, but the
1290 * condition could persist if several rx fail in a row.
1292 * 2) The peer may observe this update before the asyncrhonous copy of
1293 * prior packets is completed. The peer may overwrite the buffers of
1294 * the prior packets before they are copied.
1296 * 3) Both: the peer may observe the update, and then observe the index
1297 * decrement by the asynchronous completion callback. Who knows what
1298 * badness that will cause.
1301 iowrite32(qp->rx_index, &qp->rx_info->entry);
1306 static void ntb_transport_rxc_db(unsigned long data)
1308 struct ntb_transport_qp *qp = (void *)data;
1311 dev_dbg(&qp->ndev->pdev->dev, "%s: doorbell %d received\n",
1312 __func__, qp->qp_num);
1314 /* Limit the number of packets processed in a single interrupt to
1315 * provide fairness to others
1317 for (i = 0; i < qp->rx_max_entry; i++) {
1318 rc = ntb_process_rxc(qp);
1324 dma_async_issue_pending(qp->dma_chan);
1326 if (i == qp->rx_max_entry) {
1327 /* there is more work to do */
1328 tasklet_schedule(&qp->rxc_db_work);
1329 } else if (ntb_db_read(qp->ndev) & BIT_ULL(qp->qp_num)) {
1330 /* the doorbell bit is set: clear it */
1331 ntb_db_clear(qp->ndev, BIT_ULL(qp->qp_num));
1332 /* ntb_db_read ensures ntb_db_clear write is committed */
1333 ntb_db_read(qp->ndev);
1335 /* an interrupt may have arrived between finishing
1336 * ntb_process_rxc and clearing the doorbell bit:
1337 * there might be some more work to do.
1339 tasklet_schedule(&qp->rxc_db_work);
1343 static void ntb_tx_copy_callback(void *data)
1345 struct ntb_queue_entry *entry = data;
1346 struct ntb_transport_qp *qp = entry->qp;
1347 struct ntb_payload_header __iomem *hdr = entry->tx_hdr;
1349 iowrite32(entry->flags | DESC_DONE_FLAG, &hdr->flags);
1351 ntb_peer_db_set(qp->ndev, BIT_ULL(qp->qp_num));
1353 /* The entry length can only be zero if the packet is intended to be a
1354 * "link down" or similar. Since no payload is being sent in these
1355 * cases, there is nothing to add to the completion queue.
1357 if (entry->len > 0) {
1358 qp->tx_bytes += entry->len;
1361 qp->tx_handler(qp, qp->cb_data, entry->cb_data,
1365 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q);
1368 static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset)
1370 memcpy_toio(offset, entry->buf, entry->len);
1372 /* Ensure that the data is fully copied out before setting the flags */
1375 ntb_tx_copy_callback(entry);
1378 static void ntb_async_tx(struct ntb_transport_qp *qp,
1379 struct ntb_queue_entry *entry)
1381 struct ntb_payload_header __iomem *hdr;
1382 struct dma_async_tx_descriptor *txd;
1383 struct dma_chan *chan = qp->dma_chan;
1384 struct dma_device *device;
1385 size_t dest_off, buff_off;
1386 struct dmaengine_unmap_data *unmap;
1388 dma_cookie_t cookie;
1389 void __iomem *offset;
1390 size_t len = entry->len;
1391 void *buf = entry->buf;
1393 offset = qp->tx_mw + qp->tx_max_frame * qp->tx_index;
1394 hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
1395 entry->tx_hdr = hdr;
1397 iowrite32(entry->len, &hdr->len);
1398 iowrite32((u32)qp->tx_pkts, &hdr->ver);
1403 if (len < copy_bytes)
1406 device = chan->device;
1407 dest = qp->tx_mw_phys + qp->tx_max_frame * qp->tx_index;
1408 buff_off = (size_t)buf & ~PAGE_MASK;
1409 dest_off = (size_t)dest & ~PAGE_MASK;
1411 if (!is_dma_copy_aligned(device, buff_off, dest_off, len))
1414 unmap = dmaengine_get_unmap_data(device->dev, 1, GFP_NOWAIT);
1419 unmap->addr[0] = dma_map_page(device->dev, virt_to_page(buf),
1420 buff_off, len, DMA_TO_DEVICE);
1421 if (dma_mapping_error(device->dev, unmap->addr[0]))
1426 txd = device->device_prep_dma_memcpy(chan, dest, unmap->addr[0], len,
1427 DMA_PREP_INTERRUPT);
1431 txd->callback = ntb_tx_copy_callback;
1432 txd->callback_param = entry;
1433 dma_set_unmap(txd, unmap);
1435 cookie = dmaengine_submit(txd);
1436 if (dma_submit_error(cookie))
1439 dmaengine_unmap_put(unmap);
1441 dma_async_issue_pending(chan);
1446 dmaengine_unmap_put(unmap);
1448 dmaengine_unmap_put(unmap);
1450 ntb_memcpy_tx(entry, offset);
1454 static int ntb_process_tx(struct ntb_transport_qp *qp,
1455 struct ntb_queue_entry *entry)
1457 if (qp->tx_index == qp->remote_rx_info->entry) {
1462 if (entry->len > qp->tx_max_frame - sizeof(struct ntb_payload_header)) {
1464 qp->tx_handler(qp->cb_data, qp, NULL, -EIO);
1466 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1471 ntb_async_tx(qp, entry);
1474 qp->tx_index %= qp->tx_max_entry;
1481 static void ntb_send_link_down(struct ntb_transport_qp *qp)
1483 struct pci_dev *pdev = qp->ndev->pdev;
1484 struct ntb_queue_entry *entry;
1487 if (!qp->link_is_up)
1490 dev_info(&pdev->dev, "qp %d: Send Link Down\n", qp->qp_num);
1492 for (i = 0; i < NTB_LINK_DOWN_TIMEOUT; i++) {
1493 entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1502 entry->cb_data = NULL;
1505 entry->flags = LINK_DOWN_FLAG;
1507 rc = ntb_process_tx(qp, entry);
1509 dev_err(&pdev->dev, "ntb: QP%d unable to send linkdown msg\n",
1512 ntb_qp_link_down_reset(qp);
1516 * ntb_transport_create_queue - Create a new NTB transport layer queue
1517 * @rx_handler: receive callback function
1518 * @tx_handler: transmit callback function
1519 * @event_handler: event callback function
1521 * Create a new NTB transport layer queue and provide the queue with a callback
1522 * routine for both transmit and receive. The receive callback routine will be
1523 * used to pass up data when the transport has received it on the queue. The
1524 * transmit callback routine will be called when the transport has completed the
1525 * transmission of the data on the queue and the data is ready to be freed.
1527 * RETURNS: pointer to newly created ntb_queue, NULL on error.
1529 struct ntb_transport_qp *
1530 ntb_transport_create_queue(void *data, struct device *client_dev,
1531 const struct ntb_queue_handlers *handlers)
1533 struct ntb_dev *ndev;
1534 struct pci_dev *pdev;
1535 struct ntb_transport_ctx *nt;
1536 struct ntb_queue_entry *entry;
1537 struct ntb_transport_qp *qp;
1539 unsigned int free_queue;
1542 ndev = dev_ntb(client_dev->parent);
1546 free_queue = ffs(nt->qp_bitmap);
1550 /* decrement free_queue to make it zero based */
1553 qp = &nt->qp_vec[free_queue];
1554 qp_bit = BIT_ULL(qp->qp_num);
1556 nt->qp_bitmap_free &= ~qp_bit;
1559 qp->rx_handler = handlers->rx_handler;
1560 qp->tx_handler = handlers->tx_handler;
1561 qp->event_handler = handlers->event_handler;
1564 qp->dma_chan = dma_find_channel(DMA_MEMCPY);
1565 if (!qp->dma_chan) {
1567 dev_info(&pdev->dev, "Unable to allocate DMA channel, using CPU instead\n");
1570 for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
1571 entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
1576 ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry,
1580 for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
1581 entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
1586 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1590 ntb_db_clear(qp->ndev, qp_bit);
1591 ntb_db_clear_mask(qp->ndev, qp_bit);
1593 dev_info(&pdev->dev, "NTB Transport QP %d created\n", qp->qp_num);
1598 while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1601 while ((entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q)))
1605 nt->qp_bitmap_free |= qp_bit;
1609 EXPORT_SYMBOL_GPL(ntb_transport_create_queue);
1612 * ntb_transport_free_queue - Frees NTB transport queue
1613 * @qp: NTB queue to be freed
1615 * Frees NTB transport queue
1617 void ntb_transport_free_queue(struct ntb_transport_qp *qp)
1619 struct ntb_transport_ctx *nt = qp->transport;
1620 struct pci_dev *pdev;
1621 struct ntb_queue_entry *entry;
1627 pdev = qp->ndev->pdev;
1630 struct dma_chan *chan = qp->dma_chan;
1631 /* Putting the dma_chan to NULL will force any new traffic to be
1632 * processed by the CPU instead of the DAM engine
1634 qp->dma_chan = NULL;
1636 /* Try to be nice and wait for any queued DMA engine
1637 * transactions to process before smashing it with a rock
1639 dma_sync_wait(chan, qp->last_cookie);
1640 dmaengine_terminate_all(chan);
1644 qp_bit = BIT_ULL(qp->qp_num);
1646 ntb_db_set_mask(qp->ndev, qp_bit);
1647 tasklet_disable(&qp->rxc_db_work);
1649 cancel_delayed_work_sync(&qp->link_work);
1652 qp->rx_handler = NULL;
1653 qp->tx_handler = NULL;
1654 qp->event_handler = NULL;
1656 while ((entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q)))
1659 while ((entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q))) {
1660 dev_warn(&pdev->dev, "Freeing item from a non-empty queue\n");
1664 while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1667 nt->qp_bitmap_free |= qp_bit;
1669 dev_info(&pdev->dev, "NTB Transport QP %d freed\n", qp->qp_num);
1671 EXPORT_SYMBOL_GPL(ntb_transport_free_queue);
1674 * ntb_transport_rx_remove - Dequeues enqueued rx packet
1675 * @qp: NTB queue to be freed
1676 * @len: pointer to variable to write enqueued buffers length
1678 * Dequeues unused buffers from receive queue. Should only be used during
1681 * RETURNS: NULL error value on error, or void* for success.
1683 void *ntb_transport_rx_remove(struct ntb_transport_qp *qp, unsigned int *len)
1685 struct ntb_queue_entry *entry;
1688 if (!qp || qp->client_ready)
1691 entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q);
1695 buf = entry->cb_data;
1698 ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry, &qp->rx_free_q);
1702 EXPORT_SYMBOL_GPL(ntb_transport_rx_remove);
1705 * ntb_transport_rx_enqueue - Enqueue a new NTB queue entry
1706 * @qp: NTB transport layer queue the entry is to be enqueued on
1707 * @cb: per buffer pointer for callback function to use
1708 * @data: pointer to data buffer that incoming packets will be copied into
1709 * @len: length of the data buffer
1711 * Enqueue a new receive buffer onto the transport queue into which a NTB
1712 * payload can be received into.
1714 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
1716 int ntb_transport_rx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
1719 struct ntb_queue_entry *entry;
1724 entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q);
1728 entry->cb_data = cb;
1732 ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry, &qp->rx_pend_q);
1736 EXPORT_SYMBOL_GPL(ntb_transport_rx_enqueue);
1739 * ntb_transport_tx_enqueue - Enqueue a new NTB queue entry
1740 * @qp: NTB transport layer queue the entry is to be enqueued on
1741 * @cb: per buffer pointer for callback function to use
1742 * @data: pointer to data buffer that will be sent
1743 * @len: length of the data buffer
1745 * Enqueue a new transmit buffer onto the transport queue from which a NTB
1746 * payload will be transmitted. This assumes that a lock is being held to
1747 * serialize access to the qp.
1749 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
1751 int ntb_transport_tx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
1754 struct ntb_queue_entry *entry;
1757 if (!qp || !qp->link_is_up || !len)
1760 entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1762 qp->tx_err_no_buf++;
1766 entry->cb_data = cb;
1771 rc = ntb_process_tx(qp, entry);
1773 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1778 EXPORT_SYMBOL_GPL(ntb_transport_tx_enqueue);
1781 * ntb_transport_link_up - Notify NTB transport of client readiness to use queue
1782 * @qp: NTB transport layer queue to be enabled
1784 * Notify NTB transport layer of client readiness to use queue
1786 void ntb_transport_link_up(struct ntb_transport_qp *qp)
1791 qp->client_ready = true;
1793 if (qp->transport->link_is_up)
1794 schedule_delayed_work(&qp->link_work, 0);
1796 EXPORT_SYMBOL_GPL(ntb_transport_link_up);
1799 * ntb_transport_link_down - Notify NTB transport to no longer enqueue data
1800 * @qp: NTB transport layer queue to be disabled
1802 * Notify NTB transport layer of client's desire to no longer receive data on
1803 * transport queue specified. It is the client's responsibility to ensure all
1804 * entries on queue are purged or otherwise handled appropriately.
1806 void ntb_transport_link_down(struct ntb_transport_qp *qp)
1808 struct pci_dev *pdev;
1814 pdev = qp->ndev->pdev;
1815 qp->client_ready = false;
1817 val = ntb_spad_read(qp->ndev, QP_LINKS);
1819 ntb_peer_spad_write(qp->ndev, QP_LINKS,
1820 val & ~BIT(qp->qp_num));
1823 ntb_send_link_down(qp);
1825 cancel_delayed_work_sync(&qp->link_work);
1827 EXPORT_SYMBOL_GPL(ntb_transport_link_down);
1830 * ntb_transport_link_query - Query transport link state
1831 * @qp: NTB transport layer queue to be queried
1833 * Query connectivity to the remote system of the NTB transport queue
1835 * RETURNS: true for link up or false for link down
1837 bool ntb_transport_link_query(struct ntb_transport_qp *qp)
1842 return qp->link_is_up;
1844 EXPORT_SYMBOL_GPL(ntb_transport_link_query);
1847 * ntb_transport_qp_num - Query the qp number
1848 * @qp: NTB transport layer queue to be queried
1850 * Query qp number of the NTB transport queue
1852 * RETURNS: a zero based number specifying the qp number
1854 unsigned char ntb_transport_qp_num(struct ntb_transport_qp *qp)
1861 EXPORT_SYMBOL_GPL(ntb_transport_qp_num);
1864 * ntb_transport_max_size - Query the max payload size of a qp
1865 * @qp: NTB transport layer queue to be queried
1867 * Query the maximum payload size permissible on the given qp
1869 * RETURNS: the max payload size of a qp
1871 unsigned int ntb_transport_max_size(struct ntb_transport_qp *qp)
1879 return qp->tx_max_frame - sizeof(struct ntb_payload_header);
1881 /* If DMA engine usage is possible, try to find the max size for that */
1882 max = qp->tx_max_frame - sizeof(struct ntb_payload_header);
1883 max -= max % (1 << qp->dma_chan->device->copy_align);
1887 EXPORT_SYMBOL_GPL(ntb_transport_max_size);
1889 static void ntb_transport_doorbell_callback(void *data, int vector)
1891 struct ntb_transport_ctx *nt = data;
1892 struct ntb_transport_qp *qp;
1894 unsigned int qp_num;
1896 db_bits = (nt->qp_bitmap & ~nt->qp_bitmap_free &
1897 ntb_db_vector_mask(nt->ndev, vector));
1900 qp_num = __ffs(db_bits);
1901 qp = &nt->qp_vec[qp_num];
1903 tasklet_schedule(&qp->rxc_db_work);
1905 db_bits &= ~BIT_ULL(qp_num);
1909 static const struct ntb_ctx_ops ntb_transport_ops = {
1910 .link_event = ntb_transport_event_callback,
1911 .db_event = ntb_transport_doorbell_callback,
1914 static struct ntb_client ntb_transport_client = {
1916 .probe = ntb_transport_probe,
1917 .remove = ntb_transport_free,
1921 static int __init ntb_transport_init(void)
1925 if (debugfs_initialized())
1926 nt_debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
1928 rc = bus_register(&ntb_transport_bus);
1932 rc = ntb_register_client(&ntb_transport_client);
1939 bus_unregister(&ntb_transport_bus);
1941 debugfs_remove_recursive(nt_debugfs_dir);
1944 module_init(ntb_transport_init);
1946 static void __exit ntb_transport_exit(void)
1948 debugfs_remove_recursive(nt_debugfs_dir);
1950 ntb_unregister_client(&ntb_transport_client);
1951 bus_unregister(&ntb_transport_bus);
1953 module_exit(ntb_transport_exit);