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/uaccess.h>
62 #include "linux/ntb.h"
63 #include "linux/ntb_transport.h"
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"
70 MODULE_DESCRIPTION(NTB_TRANSPORT_DESC);
71 MODULE_VERSION(NTB_TRANSPORT_VER);
72 MODULE_LICENSE("Dual BSD/GPL");
73 MODULE_AUTHOR("Intel Corporation");
75 static unsigned long max_mw_size;
76 module_param(max_mw_size, ulong, 0644);
77 MODULE_PARM_DESC(max_mw_size, "Limit size of large memory windows");
79 static unsigned int transport_mtu = 0x10000;
80 module_param(transport_mtu, uint, 0644);
81 MODULE_PARM_DESC(transport_mtu, "Maximum size of NTB transport packets");
83 static unsigned char max_num_clients;
84 module_param(max_num_clients, byte, 0644);
85 MODULE_PARM_DESC(max_num_clients, "Maximum number of NTB transport clients");
87 static unsigned int copy_bytes = 1024;
88 module_param(copy_bytes, uint, 0644);
89 MODULE_PARM_DESC(copy_bytes, "Threshold under which NTB will use the CPU to copy instead of DMA");
92 module_param(use_dma, bool, 0644);
93 MODULE_PARM_DESC(use_dma, "Use DMA engine to perform large data copy");
95 static struct dentry *nt_debugfs_dir;
97 struct ntb_queue_entry {
98 /* ntb_queue list reference */
99 struct list_head entry;
100 /* pointers to data to be transferred */
106 struct ntb_transport_qp *qp;
108 struct ntb_payload_header __iomem *tx_hdr;
109 struct ntb_payload_header *rx_hdr;
118 struct ntb_transport_qp {
119 struct ntb_transport_ctx *transport;
120 struct ntb_dev *ndev;
122 struct dma_chan *dma_chan;
127 u8 qp_num; /* Only 64 QP's are allowed. 0-63 */
130 struct ntb_rx_info __iomem *rx_info;
131 struct ntb_rx_info *remote_rx_info;
133 void (*tx_handler)(struct ntb_transport_qp *qp, void *qp_data,
134 void *data, int len);
135 struct list_head tx_free_q;
136 spinlock_t ntb_tx_free_q_lock;
138 dma_addr_t tx_mw_phys;
139 unsigned int tx_index;
140 unsigned int tx_max_entry;
141 unsigned int tx_max_frame;
143 void (*rx_handler)(struct ntb_transport_qp *qp, void *qp_data,
144 void *data, int len);
145 struct list_head rx_pend_q;
146 struct list_head rx_free_q;
147 spinlock_t ntb_rx_pend_q_lock;
148 spinlock_t ntb_rx_free_q_lock;
150 unsigned int rx_index;
151 unsigned int rx_max_entry;
152 unsigned int rx_max_frame;
153 dma_cookie_t last_cookie;
154 struct tasklet_struct rxc_db_work;
156 void (*event_handler)(void *data, int status);
157 struct delayed_work link_work;
158 struct work_struct link_cleanup;
160 struct dentry *debugfs_dir;
161 struct dentry *debugfs_stats;
180 struct ntb_transport_mw {
181 phys_addr_t phys_addr;
182 resource_size_t phys_size;
183 resource_size_t xlat_align;
184 resource_size_t xlat_align_size;
192 struct ntb_transport_client_dev {
193 struct list_head entry;
194 struct ntb_transport_ctx *nt;
198 struct ntb_transport_ctx {
199 struct list_head entry;
200 struct list_head client_devs;
202 struct ntb_dev *ndev;
204 struct ntb_transport_mw *mw_vec;
205 struct ntb_transport_qp *qp_vec;
206 unsigned int mw_count;
207 unsigned int qp_count;
212 struct delayed_work link_work;
213 struct work_struct link_cleanup;
217 DESC_DONE_FLAG = BIT(0),
218 LINK_DOWN_FLAG = BIT(1),
221 struct ntb_payload_header {
239 #define dev_client_dev(__dev) \
240 container_of((__dev), struct ntb_transport_client_dev, dev)
242 #define drv_client(__drv) \
243 container_of((__drv), struct ntb_transport_client, driver)
245 #define QP_TO_MW(nt, qp) ((qp) % nt->mw_count)
246 #define NTB_QP_DEF_NUM_ENTRIES 100
247 #define NTB_LINK_DOWN_TIMEOUT 10
249 static void ntb_transport_rxc_db(unsigned long data);
250 static const struct ntb_ctx_ops ntb_transport_ops;
251 static struct ntb_client ntb_transport_client;
253 static int ntb_transport_bus_match(struct device *dev,
254 struct device_driver *drv)
256 return !strncmp(dev_name(dev), drv->name, strlen(drv->name));
259 static int ntb_transport_bus_probe(struct device *dev)
261 const struct ntb_transport_client *client;
266 client = drv_client(dev->driver);
267 rc = client->probe(dev);
274 static int ntb_transport_bus_remove(struct device *dev)
276 const struct ntb_transport_client *client;
278 client = drv_client(dev->driver);
286 static struct bus_type ntb_transport_bus = {
287 .name = "ntb_transport",
288 .match = ntb_transport_bus_match,
289 .probe = ntb_transport_bus_probe,
290 .remove = ntb_transport_bus_remove,
293 static LIST_HEAD(ntb_transport_list);
295 static int ntb_bus_init(struct ntb_transport_ctx *nt)
297 list_add(&nt->entry, &ntb_transport_list);
301 static void ntb_bus_remove(struct ntb_transport_ctx *nt)
303 struct ntb_transport_client_dev *client_dev, *cd;
305 list_for_each_entry_safe(client_dev, cd, &nt->client_devs, entry) {
306 dev_err(client_dev->dev.parent, "%s still attached to bus, removing\n",
307 dev_name(&client_dev->dev));
308 list_del(&client_dev->entry);
309 device_unregister(&client_dev->dev);
312 list_del(&nt->entry);
315 static void ntb_transport_client_release(struct device *dev)
317 struct ntb_transport_client_dev *client_dev;
319 client_dev = dev_client_dev(dev);
324 * ntb_transport_unregister_client_dev - Unregister NTB client device
325 * @device_name: Name of NTB client device
327 * Unregister an NTB client device with the NTB transport layer
329 void ntb_transport_unregister_client_dev(char *device_name)
331 struct ntb_transport_client_dev *client, *cd;
332 struct ntb_transport_ctx *nt;
334 list_for_each_entry(nt, &ntb_transport_list, entry)
335 list_for_each_entry_safe(client, cd, &nt->client_devs, entry)
336 if (!strncmp(dev_name(&client->dev), device_name,
337 strlen(device_name))) {
338 list_del(&client->entry);
339 device_unregister(&client->dev);
342 EXPORT_SYMBOL_GPL(ntb_transport_unregister_client_dev);
345 * ntb_transport_register_client_dev - Register NTB client device
346 * @device_name: Name of NTB client device
348 * Register an NTB client device with the NTB transport layer
350 int ntb_transport_register_client_dev(char *device_name)
352 struct ntb_transport_client_dev *client_dev;
353 struct ntb_transport_ctx *nt;
357 if (list_empty(&ntb_transport_list))
360 list_for_each_entry(nt, &ntb_transport_list, entry) {
363 node = dev_to_node(&nt->ndev->dev);
365 client_dev = kzalloc_node(sizeof(*client_dev),
372 dev = &client_dev->dev;
374 /* setup and register client devices */
375 dev_set_name(dev, "%s%d", device_name, i);
376 dev->bus = &ntb_transport_bus;
377 dev->release = ntb_transport_client_release;
378 dev->parent = &nt->ndev->dev;
380 rc = device_register(dev);
386 list_add_tail(&client_dev->entry, &nt->client_devs);
393 ntb_transport_unregister_client_dev(device_name);
397 EXPORT_SYMBOL_GPL(ntb_transport_register_client_dev);
400 * ntb_transport_register_client - Register NTB client driver
401 * @drv: NTB client driver to be registered
403 * Register an NTB client driver with the NTB transport layer
405 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
407 int ntb_transport_register_client(struct ntb_transport_client *drv)
409 drv->driver.bus = &ntb_transport_bus;
411 if (list_empty(&ntb_transport_list))
414 return driver_register(&drv->driver);
416 EXPORT_SYMBOL_GPL(ntb_transport_register_client);
419 * ntb_transport_unregister_client - Unregister NTB client driver
420 * @drv: NTB client driver to be unregistered
422 * Unregister an NTB client driver with the NTB transport layer
424 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
426 void ntb_transport_unregister_client(struct ntb_transport_client *drv)
428 driver_unregister(&drv->driver);
430 EXPORT_SYMBOL_GPL(ntb_transport_unregister_client);
432 static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count,
435 struct ntb_transport_qp *qp;
437 ssize_t ret, out_offset, out_count;
441 buf = kmalloc(out_count, GFP_KERNEL);
445 qp = filp->private_data;
447 out_offset += snprintf(buf + out_offset, out_count - out_offset,
449 out_offset += snprintf(buf + out_offset, out_count - out_offset,
450 "rx_bytes - \t%llu\n", qp->rx_bytes);
451 out_offset += snprintf(buf + out_offset, out_count - out_offset,
452 "rx_pkts - \t%llu\n", qp->rx_pkts);
453 out_offset += snprintf(buf + out_offset, out_count - out_offset,
454 "rx_memcpy - \t%llu\n", qp->rx_memcpy);
455 out_offset += snprintf(buf + out_offset, out_count - out_offset,
456 "rx_async - \t%llu\n", qp->rx_async);
457 out_offset += snprintf(buf + out_offset, out_count - out_offset,
458 "rx_ring_empty - %llu\n", qp->rx_ring_empty);
459 out_offset += snprintf(buf + out_offset, out_count - out_offset,
460 "rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
461 out_offset += snprintf(buf + out_offset, out_count - out_offset,
462 "rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
463 out_offset += snprintf(buf + out_offset, out_count - out_offset,
464 "rx_err_ver - \t%llu\n", qp->rx_err_ver);
465 out_offset += snprintf(buf + out_offset, out_count - out_offset,
466 "rx_buff - \t%p\n", qp->rx_buff);
467 out_offset += snprintf(buf + out_offset, out_count - out_offset,
468 "rx_index - \t%u\n", qp->rx_index);
469 out_offset += snprintf(buf + out_offset, out_count - out_offset,
470 "rx_max_entry - \t%u\n", qp->rx_max_entry);
472 out_offset += snprintf(buf + out_offset, out_count - out_offset,
473 "tx_bytes - \t%llu\n", qp->tx_bytes);
474 out_offset += snprintf(buf + out_offset, out_count - out_offset,
475 "tx_pkts - \t%llu\n", qp->tx_pkts);
476 out_offset += snprintf(buf + out_offset, out_count - out_offset,
477 "tx_memcpy - \t%llu\n", qp->tx_memcpy);
478 out_offset += snprintf(buf + out_offset, out_count - out_offset,
479 "tx_async - \t%llu\n", qp->tx_async);
480 out_offset += snprintf(buf + out_offset, out_count - out_offset,
481 "tx_ring_full - \t%llu\n", qp->tx_ring_full);
482 out_offset += snprintf(buf + out_offset, out_count - out_offset,
483 "tx_err_no_buf - %llu\n", qp->tx_err_no_buf);
484 out_offset += snprintf(buf + out_offset, out_count - out_offset,
485 "tx_mw - \t%p\n", qp->tx_mw);
486 out_offset += snprintf(buf + out_offset, out_count - out_offset,
487 "tx_index - \t%u\n", qp->tx_index);
488 out_offset += snprintf(buf + out_offset, out_count - out_offset,
489 "tx_max_entry - \t%u\n", qp->tx_max_entry);
491 out_offset += snprintf(buf + out_offset, out_count - out_offset,
493 qp->link_is_up ? "Up" : "Down");
494 if (out_offset > out_count)
495 out_offset = out_count;
497 ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
502 static const struct file_operations ntb_qp_debugfs_stats = {
503 .owner = THIS_MODULE,
505 .read = debugfs_read,
508 static void ntb_list_add(spinlock_t *lock, struct list_head *entry,
509 struct list_head *list)
513 spin_lock_irqsave(lock, flags);
514 list_add_tail(entry, list);
515 spin_unlock_irqrestore(lock, flags);
518 static struct ntb_queue_entry *ntb_list_rm(spinlock_t *lock,
519 struct list_head *list)
521 struct ntb_queue_entry *entry;
524 spin_lock_irqsave(lock, flags);
525 if (list_empty(list)) {
529 entry = list_first_entry(list, struct ntb_queue_entry, entry);
530 list_del(&entry->entry);
532 spin_unlock_irqrestore(lock, flags);
537 static int ntb_transport_setup_qp_mw(struct ntb_transport_ctx *nt,
540 struct ntb_transport_qp *qp = &nt->qp_vec[qp_num];
541 struct ntb_transport_mw *mw;
542 unsigned int rx_size, num_qps_mw;
543 unsigned int mw_num, mw_count, qp_count;
546 mw_count = nt->mw_count;
547 qp_count = nt->qp_count;
549 mw_num = QP_TO_MW(nt, qp_num);
550 mw = &nt->mw_vec[mw_num];
555 if (qp_count % mw_count && mw_num + 1 < qp_count / mw_count)
556 num_qps_mw = qp_count / mw_count + 1;
558 num_qps_mw = qp_count / mw_count;
560 rx_size = (unsigned int)mw->xlat_size / num_qps_mw;
561 qp->rx_buff = mw->virt_addr + rx_size * qp_num / mw_count;
562 rx_size -= sizeof(struct ntb_rx_info);
564 qp->remote_rx_info = qp->rx_buff + rx_size;
566 /* Due to housekeeping, there must be atleast 2 buffs */
567 qp->rx_max_frame = min(transport_mtu, rx_size / 2);
568 qp->rx_max_entry = rx_size / qp->rx_max_frame;
571 qp->remote_rx_info->entry = qp->rx_max_entry - 1;
573 /* setup the hdr offsets with 0's */
574 for (i = 0; i < qp->rx_max_entry; i++) {
575 void *offset = (qp->rx_buff + qp->rx_max_frame * (i + 1) -
576 sizeof(struct ntb_payload_header));
577 memset(offset, 0, sizeof(struct ntb_payload_header));
587 static void ntb_free_mw(struct ntb_transport_ctx *nt, int num_mw)
589 struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
590 struct pci_dev *pdev = nt->ndev->pdev;
595 ntb_mw_clear_trans(nt->ndev, num_mw);
596 dma_free_coherent(&pdev->dev, mw->buff_size,
597 mw->virt_addr, mw->dma_addr);
600 mw->virt_addr = NULL;
603 static int ntb_set_mw(struct ntb_transport_ctx *nt, int num_mw,
606 struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
607 struct pci_dev *pdev = nt->ndev->pdev;
608 unsigned int xlat_size, buff_size;
611 xlat_size = round_up(size, mw->xlat_align_size);
612 buff_size = round_up(size, mw->xlat_align);
614 /* No need to re-setup */
615 if (mw->xlat_size == xlat_size)
619 ntb_free_mw(nt, num_mw);
621 /* Alloc memory for receiving data. Must be aligned */
622 mw->xlat_size = xlat_size;
623 mw->buff_size = buff_size;
625 mw->virt_addr = dma_alloc_coherent(&pdev->dev, buff_size,
626 &mw->dma_addr, GFP_KERNEL);
627 if (!mw->virt_addr) {
630 dev_err(&pdev->dev, "Unable to alloc MW buff of size %d\n",
636 * we must ensure that the memory address allocated is BAR size
637 * aligned in order for the XLAT register to take the value. This
638 * is a requirement of the hardware. It is recommended to setup CMA
639 * for BAR sizes equal or greater than 4MB.
641 if (!IS_ALIGNED(mw->dma_addr, mw->xlat_align)) {
642 dev_err(&pdev->dev, "DMA memory %pad is not aligned\n",
644 ntb_free_mw(nt, num_mw);
648 /* Notify HW the memory location of the receive buffer */
649 rc = ntb_mw_set_trans(nt->ndev, num_mw, mw->dma_addr, mw->xlat_size);
651 dev_err(&pdev->dev, "Unable to set mw%d translation", num_mw);
652 ntb_free_mw(nt, num_mw);
659 static void ntb_qp_link_down_reset(struct ntb_transport_qp *qp)
661 qp->link_is_up = false;
667 qp->rx_ring_empty = 0;
668 qp->rx_err_no_buf = 0;
669 qp->rx_err_oflow = 0;
675 qp->tx_ring_full = 0;
676 qp->tx_err_no_buf = 0;
681 static void ntb_qp_link_cleanup(struct ntb_transport_qp *qp)
683 struct ntb_transport_ctx *nt = qp->transport;
684 struct pci_dev *pdev = nt->ndev->pdev;
686 dev_info(&pdev->dev, "qp %d: Link Cleanup\n", qp->qp_num);
688 cancel_delayed_work_sync(&qp->link_work);
689 ntb_qp_link_down_reset(qp);
691 if (qp->event_handler)
692 qp->event_handler(qp->cb_data, qp->link_is_up);
695 static void ntb_qp_link_cleanup_work(struct work_struct *work)
697 struct ntb_transport_qp *qp = container_of(work,
698 struct ntb_transport_qp,
700 struct ntb_transport_ctx *nt = qp->transport;
702 ntb_qp_link_cleanup(qp);
705 schedule_delayed_work(&qp->link_work,
706 msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
709 static void ntb_qp_link_down(struct ntb_transport_qp *qp)
711 schedule_work(&qp->link_cleanup);
714 static void ntb_transport_link_cleanup(struct ntb_transport_ctx *nt)
716 struct ntb_transport_qp *qp;
720 qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
722 /* Pass along the info to any clients */
723 for (i = 0; i < nt->qp_count; i++)
724 if (qp_bitmap_alloc & BIT_ULL(i)) {
726 ntb_qp_link_cleanup(qp);
727 cancel_work_sync(&qp->link_cleanup);
728 cancel_delayed_work_sync(&qp->link_work);
732 cancel_delayed_work_sync(&nt->link_work);
734 /* The scratchpad registers keep the values if the remote side
735 * goes down, blast them now to give them a sane value the next
736 * time they are accessed
738 for (i = 0; i < MAX_SPAD; i++)
739 ntb_spad_write(nt->ndev, i, 0);
742 static void ntb_transport_link_cleanup_work(struct work_struct *work)
744 struct ntb_transport_ctx *nt =
745 container_of(work, struct ntb_transport_ctx, link_cleanup);
747 ntb_transport_link_cleanup(nt);
750 static void ntb_transport_event_callback(void *data)
752 struct ntb_transport_ctx *nt = data;
754 if (ntb_link_is_up(nt->ndev, NULL, NULL) == 1)
755 schedule_delayed_work(&nt->link_work, 0);
757 schedule_work(&nt->link_cleanup);
760 static void ntb_transport_link_work(struct work_struct *work)
762 struct ntb_transport_ctx *nt =
763 container_of(work, struct ntb_transport_ctx, link_work.work);
764 struct ntb_dev *ndev = nt->ndev;
765 struct pci_dev *pdev = ndev->pdev;
766 resource_size_t size;
770 /* send the local info, in the opposite order of the way we read it */
771 for (i = 0; i < nt->mw_count; i++) {
772 size = nt->mw_vec[i].phys_size;
774 if (max_mw_size && size > max_mw_size)
777 spad = MW0_SZ_HIGH + (i * 2);
778 ntb_peer_spad_write(ndev, spad, (u32)(size >> 32));
780 spad = MW0_SZ_LOW + (i * 2);
781 ntb_peer_spad_write(ndev, spad, (u32)size);
784 ntb_peer_spad_write(ndev, NUM_MWS, nt->mw_count);
786 ntb_peer_spad_write(ndev, NUM_QPS, nt->qp_count);
788 ntb_peer_spad_write(ndev, VERSION, NTB_TRANSPORT_VERSION);
790 /* Query the remote side for its info */
791 val = ntb_spad_read(ndev, VERSION);
792 dev_dbg(&pdev->dev, "Remote version = %d\n", val);
793 if (val != NTB_TRANSPORT_VERSION)
796 val = ntb_spad_read(ndev, NUM_QPS);
797 dev_dbg(&pdev->dev, "Remote max number of qps = %d\n", val);
798 if (val != nt->qp_count)
801 val = ntb_spad_read(ndev, NUM_MWS);
802 dev_dbg(&pdev->dev, "Remote number of mws = %d\n", val);
803 if (val != nt->mw_count)
806 for (i = 0; i < nt->mw_count; i++) {
809 val = ntb_spad_read(ndev, MW0_SZ_HIGH + (i * 2));
810 val64 = (u64)val << 32;
812 val = ntb_spad_read(ndev, MW0_SZ_LOW + (i * 2));
815 dev_dbg(&pdev->dev, "Remote MW%d size = %#llx\n", i, val64);
817 rc = ntb_set_mw(nt, i, val64);
822 nt->link_is_up = true;
824 for (i = 0; i < nt->qp_count; i++) {
825 struct ntb_transport_qp *qp = &nt->qp_vec[i];
827 ntb_transport_setup_qp_mw(nt, i);
829 if (qp->client_ready)
830 schedule_delayed_work(&qp->link_work, 0);
836 for (i = 0; i < nt->mw_count; i++)
839 if (ntb_link_is_up(ndev, NULL, NULL) == 1)
840 schedule_delayed_work(&nt->link_work,
841 msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
844 static void ntb_qp_link_work(struct work_struct *work)
846 struct ntb_transport_qp *qp = container_of(work,
847 struct ntb_transport_qp,
849 struct pci_dev *pdev = qp->ndev->pdev;
850 struct ntb_transport_ctx *nt = qp->transport;
853 WARN_ON(!nt->link_is_up);
855 val = ntb_spad_read(nt->ndev, QP_LINKS);
857 ntb_peer_spad_write(nt->ndev, QP_LINKS, val | BIT(qp->qp_num));
859 /* query remote spad for qp ready bits */
860 ntb_peer_spad_read(nt->ndev, QP_LINKS);
861 dev_dbg_ratelimited(&pdev->dev, "Remote QP link status = %x\n", val);
863 /* See if the remote side is up */
864 if (val & BIT(qp->qp_num)) {
865 dev_info(&pdev->dev, "qp %d: Link Up\n", qp->qp_num);
866 qp->link_is_up = true;
868 if (qp->event_handler)
869 qp->event_handler(qp->cb_data, qp->link_is_up);
870 } else if (nt->link_is_up)
871 schedule_delayed_work(&qp->link_work,
872 msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
875 static int ntb_transport_init_queue(struct ntb_transport_ctx *nt,
878 struct ntb_transport_qp *qp;
879 struct ntb_transport_mw *mw;
881 resource_size_t mw_size;
882 unsigned int num_qps_mw, tx_size;
883 unsigned int mw_num, mw_count, qp_count;
886 mw_count = nt->mw_count;
887 qp_count = nt->qp_count;
889 mw_num = QP_TO_MW(nt, qp_num);
890 mw = &nt->mw_vec[mw_num];
892 qp = &nt->qp_vec[qp_num];
896 qp->client_ready = false;
897 qp->event_handler = NULL;
898 ntb_qp_link_down_reset(qp);
900 if (qp_count % mw_count && mw_num + 1 < qp_count / mw_count)
901 num_qps_mw = qp_count / mw_count + 1;
903 num_qps_mw = qp_count / mw_count;
905 mw_base = nt->mw_vec[mw_num].phys_addr;
906 mw_size = nt->mw_vec[mw_num].phys_size;
908 tx_size = (unsigned int)mw_size / num_qps_mw;
909 qp_offset = tx_size * qp_num / mw_count;
911 qp->tx_mw = nt->mw_vec[mw_num].vbase + qp_offset;
915 qp->tx_mw_phys = mw_base + qp_offset;
919 tx_size -= sizeof(struct ntb_rx_info);
920 qp->rx_info = qp->tx_mw + tx_size;
922 /* Due to housekeeping, there must be atleast 2 buffs */
923 qp->tx_max_frame = min(transport_mtu, tx_size / 2);
924 qp->tx_max_entry = tx_size / qp->tx_max_frame;
926 if (nt_debugfs_dir) {
927 char debugfs_name[4];
929 snprintf(debugfs_name, 4, "qp%d", qp_num);
930 qp->debugfs_dir = debugfs_create_dir(debugfs_name,
933 qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR,
935 &ntb_qp_debugfs_stats);
937 qp->debugfs_dir = NULL;
938 qp->debugfs_stats = NULL;
941 INIT_DELAYED_WORK(&qp->link_work, ntb_qp_link_work);
942 INIT_WORK(&qp->link_cleanup, ntb_qp_link_cleanup_work);
944 spin_lock_init(&qp->ntb_rx_pend_q_lock);
945 spin_lock_init(&qp->ntb_rx_free_q_lock);
946 spin_lock_init(&qp->ntb_tx_free_q_lock);
948 INIT_LIST_HEAD(&qp->rx_pend_q);
949 INIT_LIST_HEAD(&qp->rx_free_q);
950 INIT_LIST_HEAD(&qp->tx_free_q);
952 tasklet_init(&qp->rxc_db_work, ntb_transport_rxc_db,
958 static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev)
960 struct ntb_transport_ctx *nt;
961 struct ntb_transport_mw *mw;
962 unsigned int mw_count, qp_count;
967 if (ntb_db_is_unsafe(ndev))
969 "doorbell is unsafe, proceed anyway...\n");
970 if (ntb_spad_is_unsafe(ndev))
972 "scratchpad is unsafe, proceed anyway...\n");
974 node = dev_to_node(&ndev->dev);
976 nt = kzalloc_node(sizeof(*nt), GFP_KERNEL, node);
982 mw_count = ntb_mw_count(ndev);
984 nt->mw_count = mw_count;
986 nt->mw_vec = kzalloc_node(mw_count * sizeof(*nt->mw_vec),
993 for (i = 0; i < mw_count; i++) {
996 rc = ntb_mw_get_range(ndev, i, &mw->phys_addr, &mw->phys_size,
997 &mw->xlat_align, &mw->xlat_align_size);
1001 mw->vbase = ioremap_wc(mw->phys_addr, mw->phys_size);
1009 mw->virt_addr = NULL;
1013 qp_bitmap = ntb_db_valid_mask(ndev);
1015 qp_count = ilog2(qp_bitmap);
1016 if (max_num_clients && max_num_clients < qp_count)
1017 qp_count = max_num_clients;
1018 else if (mw_count < qp_count)
1019 qp_count = mw_count;
1021 qp_bitmap &= BIT_ULL(qp_count) - 1;
1023 nt->qp_count = qp_count;
1024 nt->qp_bitmap = qp_bitmap;
1025 nt->qp_bitmap_free = qp_bitmap;
1027 nt->qp_vec = kzalloc_node(qp_count * sizeof(*nt->qp_vec),
1034 for (i = 0; i < qp_count; i++) {
1035 rc = ntb_transport_init_queue(nt, i);
1040 INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work);
1041 INIT_WORK(&nt->link_cleanup, ntb_transport_link_cleanup_work);
1043 rc = ntb_set_ctx(ndev, nt, &ntb_transport_ops);
1047 INIT_LIST_HEAD(&nt->client_devs);
1048 rc = ntb_bus_init(nt);
1052 nt->link_is_up = false;
1053 ntb_link_enable(ndev, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
1054 ntb_link_event(ndev);
1059 ntb_clear_ctx(ndev);
1066 mw = &nt->mw_vec[i];
1074 static void ntb_transport_free(struct ntb_client *self, struct ntb_dev *ndev)
1076 struct ntb_transport_ctx *nt = ndev->ctx;
1077 struct ntb_transport_qp *qp;
1078 u64 qp_bitmap_alloc;
1081 ntb_transport_link_cleanup(nt);
1082 cancel_work_sync(&nt->link_cleanup);
1083 cancel_delayed_work_sync(&nt->link_work);
1085 qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
1087 /* verify that all the qp's are freed */
1088 for (i = 0; i < nt->qp_count; i++) {
1089 qp = &nt->qp_vec[i];
1090 if (qp_bitmap_alloc & BIT_ULL(i))
1091 ntb_transport_free_queue(qp);
1092 debugfs_remove_recursive(qp->debugfs_dir);
1095 ntb_link_disable(ndev);
1096 ntb_clear_ctx(ndev);
1100 for (i = nt->mw_count; i--; ) {
1102 iounmap(nt->mw_vec[i].vbase);
1110 static void ntb_rx_copy_callback(void *data)
1112 struct ntb_queue_entry *entry = data;
1113 struct ntb_transport_qp *qp = entry->qp;
1114 void *cb_data = entry->cb_data;
1115 unsigned int len = entry->len;
1116 struct ntb_payload_header *hdr = entry->rx_hdr;
1120 iowrite32(entry->index, &qp->rx_info->entry);
1122 ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry, &qp->rx_free_q);
1124 if (qp->rx_handler && qp->client_ready)
1125 qp->rx_handler(qp, qp->cb_data, cb_data, len);
1128 static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void *offset)
1130 void *buf = entry->buf;
1131 size_t len = entry->len;
1133 memcpy(buf, offset, len);
1135 /* Ensure that the data is fully copied out before clearing the flag */
1138 ntb_rx_copy_callback(entry);
1141 static void ntb_async_rx(struct ntb_queue_entry *entry, void *offset,
1144 struct dma_async_tx_descriptor *txd;
1145 struct ntb_transport_qp *qp = entry->qp;
1146 struct dma_chan *chan = qp->dma_chan;
1147 struct dma_device *device;
1148 size_t pay_off, buff_off;
1149 struct dmaengine_unmap_data *unmap;
1150 dma_cookie_t cookie;
1151 void *buf = entry->buf;
1158 if (len < copy_bytes)
1161 device = chan->device;
1162 pay_off = (size_t)offset & ~PAGE_MASK;
1163 buff_off = (size_t)buf & ~PAGE_MASK;
1165 if (!is_dma_copy_aligned(device, pay_off, buff_off, len))
1168 unmap = dmaengine_get_unmap_data(device->dev, 2, GFP_NOWAIT);
1173 unmap->addr[0] = dma_map_page(device->dev, virt_to_page(offset),
1174 pay_off, len, DMA_TO_DEVICE);
1175 if (dma_mapping_error(device->dev, unmap->addr[0]))
1180 unmap->addr[1] = dma_map_page(device->dev, virt_to_page(buf),
1181 buff_off, len, DMA_FROM_DEVICE);
1182 if (dma_mapping_error(device->dev, unmap->addr[1]))
1185 unmap->from_cnt = 1;
1187 txd = device->device_prep_dma_memcpy(chan, unmap->addr[1],
1188 unmap->addr[0], len,
1189 DMA_PREP_INTERRUPT);
1193 txd->callback = ntb_rx_copy_callback;
1194 txd->callback_param = entry;
1195 dma_set_unmap(txd, unmap);
1197 cookie = dmaengine_submit(txd);
1198 if (dma_submit_error(cookie))
1201 dmaengine_unmap_put(unmap);
1203 qp->last_cookie = cookie;
1210 dmaengine_unmap_put(unmap);
1212 dmaengine_unmap_put(unmap);
1214 /* If the callbacks come out of order, the writing of the index to the
1215 * last completed will be out of order. This may result in the
1216 * receive stalling forever.
1218 dma_sync_wait(chan, qp->last_cookie);
1220 ntb_memcpy_rx(entry, offset);
1224 static int ntb_process_rxc(struct ntb_transport_qp *qp)
1226 struct ntb_payload_header *hdr;
1227 struct ntb_queue_entry *entry;
1231 offset = qp->rx_buff + qp->rx_max_frame * qp->rx_index;
1232 hdr = offset + qp->rx_max_frame - sizeof(struct ntb_payload_header);
1234 dev_dbg(&qp->ndev->pdev->dev, "qp %d: RX ver %u len %d flags %x\n",
1235 qp->qp_num, hdr->ver, hdr->len, hdr->flags);
1237 if (!(hdr->flags & DESC_DONE_FLAG)) {
1238 dev_dbg(&qp->ndev->pdev->dev, "done flag not set\n");
1239 qp->rx_ring_empty++;
1243 if (hdr->flags & LINK_DOWN_FLAG) {
1244 dev_dbg(&qp->ndev->pdev->dev, "link down flag set\n");
1245 ntb_qp_link_down(qp);
1250 if (hdr->ver != (u32)qp->rx_pkts) {
1251 dev_dbg(&qp->ndev->pdev->dev,
1252 "version mismatch, expected %llu - got %u\n",
1253 qp->rx_pkts, hdr->ver);
1258 entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q);
1260 dev_dbg(&qp->ndev->pdev->dev, "no receive buffer\n");
1261 qp->rx_err_no_buf++;
1267 if (hdr->len > entry->len) {
1268 dev_dbg(&qp->ndev->pdev->dev,
1269 "receive buffer overflow! Wanted %d got %d\n",
1270 hdr->len, entry->len);
1277 dev_dbg(&qp->ndev->pdev->dev,
1278 "RX OK index %u ver %u size %d into buf size %d\n",
1279 qp->rx_index, hdr->ver, hdr->len, entry->len);
1281 qp->rx_bytes += hdr->len;
1284 entry->index = qp->rx_index;
1285 entry->rx_hdr = hdr;
1287 ntb_async_rx(entry, offset, hdr->len);
1290 qp->rx_index %= qp->rx_max_entry;
1295 /* FIXME: if this syncrhonous update of the rx_index gets ahead of
1296 * asyncrhonous ntb_rx_copy_callback of previous entry, there are three
1299 * 1) The peer might miss this update, but observe the update
1300 * from the memcpy completion callback. In this case, the buffer will
1301 * not be freed on the peer to be reused for a different packet. The
1302 * successful rx of a later packet would clear the condition, but the
1303 * condition could persist if several rx fail in a row.
1305 * 2) The peer may observe this update before the asyncrhonous copy of
1306 * prior packets is completed. The peer may overwrite the buffers of
1307 * the prior packets before they are copied.
1309 * 3) Both: the peer may observe the update, and then observe the index
1310 * decrement by the asynchronous completion callback. Who knows what
1311 * badness that will cause.
1314 iowrite32(qp->rx_index, &qp->rx_info->entry);
1319 static void ntb_transport_rxc_db(unsigned long data)
1321 struct ntb_transport_qp *qp = (void *)data;
1324 dev_dbg(&qp->ndev->pdev->dev, "%s: doorbell %d received\n",
1325 __func__, qp->qp_num);
1327 /* Limit the number of packets processed in a single interrupt to
1328 * provide fairness to others
1330 for (i = 0; i < qp->rx_max_entry; i++) {
1331 rc = ntb_process_rxc(qp);
1337 dma_async_issue_pending(qp->dma_chan);
1339 if (i == qp->rx_max_entry) {
1340 /* there is more work to do */
1341 tasklet_schedule(&qp->rxc_db_work);
1342 } else if (ntb_db_read(qp->ndev) & BIT_ULL(qp->qp_num)) {
1343 /* the doorbell bit is set: clear it */
1344 ntb_db_clear(qp->ndev, BIT_ULL(qp->qp_num));
1345 /* ntb_db_read ensures ntb_db_clear write is committed */
1346 ntb_db_read(qp->ndev);
1348 /* an interrupt may have arrived between finishing
1349 * ntb_process_rxc and clearing the doorbell bit:
1350 * there might be some more work to do.
1352 tasklet_schedule(&qp->rxc_db_work);
1356 static void ntb_tx_copy_callback(void *data)
1358 struct ntb_queue_entry *entry = data;
1359 struct ntb_transport_qp *qp = entry->qp;
1360 struct ntb_payload_header __iomem *hdr = entry->tx_hdr;
1362 iowrite32(entry->flags | DESC_DONE_FLAG, &hdr->flags);
1364 ntb_peer_db_set(qp->ndev, BIT_ULL(qp->qp_num));
1366 /* The entry length can only be zero if the packet is intended to be a
1367 * "link down" or similar. Since no payload is being sent in these
1368 * cases, there is nothing to add to the completion queue.
1370 if (entry->len > 0) {
1371 qp->tx_bytes += entry->len;
1374 qp->tx_handler(qp, qp->cb_data, entry->cb_data,
1378 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q);
1381 static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset)
1383 #ifdef ARCH_HAS_NOCACHE_UACCESS
1385 * Using non-temporal mov to improve performance on non-cached
1386 * writes, even though we aren't actually copying from user space.
1388 __copy_from_user_inatomic_nocache(offset, entry->buf, entry->len);
1390 memcpy_toio(offset, entry->buf, entry->len);
1393 /* Ensure that the data is fully copied out before setting the flags */
1396 ntb_tx_copy_callback(entry);
1399 static void ntb_async_tx(struct ntb_transport_qp *qp,
1400 struct ntb_queue_entry *entry)
1402 struct ntb_payload_header __iomem *hdr;
1403 struct dma_async_tx_descriptor *txd;
1404 struct dma_chan *chan = qp->dma_chan;
1405 struct dma_device *device;
1406 size_t dest_off, buff_off;
1407 struct dmaengine_unmap_data *unmap;
1409 dma_cookie_t cookie;
1410 void __iomem *offset;
1411 size_t len = entry->len;
1412 void *buf = entry->buf;
1414 offset = qp->tx_mw + qp->tx_max_frame * qp->tx_index;
1415 hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
1416 entry->tx_hdr = hdr;
1418 iowrite32(entry->len, &hdr->len);
1419 iowrite32((u32)qp->tx_pkts, &hdr->ver);
1424 if (len < copy_bytes)
1427 device = chan->device;
1428 dest = qp->tx_mw_phys + qp->tx_max_frame * qp->tx_index;
1429 buff_off = (size_t)buf & ~PAGE_MASK;
1430 dest_off = (size_t)dest & ~PAGE_MASK;
1432 if (!is_dma_copy_aligned(device, buff_off, dest_off, len))
1435 unmap = dmaengine_get_unmap_data(device->dev, 1, GFP_NOWAIT);
1440 unmap->addr[0] = dma_map_page(device->dev, virt_to_page(buf),
1441 buff_off, len, DMA_TO_DEVICE);
1442 if (dma_mapping_error(device->dev, unmap->addr[0]))
1447 txd = device->device_prep_dma_memcpy(chan, dest, unmap->addr[0], len,
1448 DMA_PREP_INTERRUPT);
1452 txd->callback = ntb_tx_copy_callback;
1453 txd->callback_param = entry;
1454 dma_set_unmap(txd, unmap);
1456 cookie = dmaengine_submit(txd);
1457 if (dma_submit_error(cookie))
1460 dmaengine_unmap_put(unmap);
1462 dma_async_issue_pending(chan);
1467 dmaengine_unmap_put(unmap);
1469 dmaengine_unmap_put(unmap);
1471 ntb_memcpy_tx(entry, offset);
1475 static int ntb_process_tx(struct ntb_transport_qp *qp,
1476 struct ntb_queue_entry *entry)
1478 if (qp->tx_index == qp->remote_rx_info->entry) {
1483 if (entry->len > qp->tx_max_frame - sizeof(struct ntb_payload_header)) {
1485 qp->tx_handler(qp->cb_data, qp, NULL, -EIO);
1487 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1492 ntb_async_tx(qp, entry);
1495 qp->tx_index %= qp->tx_max_entry;
1502 static void ntb_send_link_down(struct ntb_transport_qp *qp)
1504 struct pci_dev *pdev = qp->ndev->pdev;
1505 struct ntb_queue_entry *entry;
1508 if (!qp->link_is_up)
1511 dev_info(&pdev->dev, "qp %d: Send Link Down\n", qp->qp_num);
1513 for (i = 0; i < NTB_LINK_DOWN_TIMEOUT; i++) {
1514 entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1523 entry->cb_data = NULL;
1526 entry->flags = LINK_DOWN_FLAG;
1528 rc = ntb_process_tx(qp, entry);
1530 dev_err(&pdev->dev, "ntb: QP%d unable to send linkdown msg\n",
1533 ntb_qp_link_down_reset(qp);
1536 static bool ntb_dma_filter_fn(struct dma_chan *chan, void *node)
1538 return dev_to_node(&chan->dev->device) == (int)(unsigned long)node;
1542 * ntb_transport_create_queue - Create a new NTB transport layer queue
1543 * @rx_handler: receive callback function
1544 * @tx_handler: transmit callback function
1545 * @event_handler: event callback function
1547 * Create a new NTB transport layer queue and provide the queue with a callback
1548 * routine for both transmit and receive. The receive callback routine will be
1549 * used to pass up data when the transport has received it on the queue. The
1550 * transmit callback routine will be called when the transport has completed the
1551 * transmission of the data on the queue and the data is ready to be freed.
1553 * RETURNS: pointer to newly created ntb_queue, NULL on error.
1555 struct ntb_transport_qp *
1556 ntb_transport_create_queue(void *data, struct device *client_dev,
1557 const struct ntb_queue_handlers *handlers)
1559 struct ntb_dev *ndev;
1560 struct pci_dev *pdev;
1561 struct ntb_transport_ctx *nt;
1562 struct ntb_queue_entry *entry;
1563 struct ntb_transport_qp *qp;
1565 unsigned int free_queue;
1566 dma_cap_mask_t dma_mask;
1570 ndev = dev_ntb(client_dev->parent);
1574 node = dev_to_node(&ndev->dev);
1576 free_queue = ffs(nt->qp_bitmap);
1580 /* decrement free_queue to make it zero based */
1583 qp = &nt->qp_vec[free_queue];
1584 qp_bit = BIT_ULL(qp->qp_num);
1586 nt->qp_bitmap_free &= ~qp_bit;
1589 qp->rx_handler = handlers->rx_handler;
1590 qp->tx_handler = handlers->tx_handler;
1591 qp->event_handler = handlers->event_handler;
1593 dma_cap_zero(dma_mask);
1594 dma_cap_set(DMA_MEMCPY, dma_mask);
1597 qp->dma_chan = dma_request_channel(dma_mask, ntb_dma_filter_fn,
1598 (void *)(unsigned long)node);
1600 dev_info(&pdev->dev, "Unable to allocate DMA channel\n");
1602 qp->dma_chan = NULL;
1604 dev_dbg(&pdev->dev, "Using %s memcpy\n", qp->dma_chan ? "DMA" : "CPU");
1606 for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
1607 entry = kzalloc_node(sizeof(*entry), GFP_ATOMIC, node);
1612 ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry,
1616 for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
1617 entry = kzalloc_node(sizeof(*entry), GFP_ATOMIC, node);
1622 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1626 ntb_db_clear(qp->ndev, qp_bit);
1627 ntb_db_clear_mask(qp->ndev, qp_bit);
1629 dev_info(&pdev->dev, "NTB Transport QP %d created\n", qp->qp_num);
1634 while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1637 while ((entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q)))
1640 dma_release_channel(qp->dma_chan);
1641 nt->qp_bitmap_free |= qp_bit;
1645 EXPORT_SYMBOL_GPL(ntb_transport_create_queue);
1648 * ntb_transport_free_queue - Frees NTB transport queue
1649 * @qp: NTB queue to be freed
1651 * Frees NTB transport queue
1653 void ntb_transport_free_queue(struct ntb_transport_qp *qp)
1655 struct ntb_transport_ctx *nt = qp->transport;
1656 struct pci_dev *pdev;
1657 struct ntb_queue_entry *entry;
1663 pdev = qp->ndev->pdev;
1666 struct dma_chan *chan = qp->dma_chan;
1667 /* Putting the dma_chan to NULL will force any new traffic to be
1668 * processed by the CPU instead of the DAM engine
1670 qp->dma_chan = NULL;
1672 /* Try to be nice and wait for any queued DMA engine
1673 * transactions to process before smashing it with a rock
1675 dma_sync_wait(chan, qp->last_cookie);
1676 dmaengine_terminate_all(chan);
1677 dma_release_channel(chan);
1680 qp_bit = BIT_ULL(qp->qp_num);
1682 ntb_db_set_mask(qp->ndev, qp_bit);
1683 tasklet_disable(&qp->rxc_db_work);
1685 cancel_delayed_work_sync(&qp->link_work);
1688 qp->rx_handler = NULL;
1689 qp->tx_handler = NULL;
1690 qp->event_handler = NULL;
1692 while ((entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q)))
1695 while ((entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q))) {
1696 dev_warn(&pdev->dev, "Freeing item from a non-empty queue\n");
1700 while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
1703 nt->qp_bitmap_free |= qp_bit;
1705 dev_info(&pdev->dev, "NTB Transport QP %d freed\n", qp->qp_num);
1707 EXPORT_SYMBOL_GPL(ntb_transport_free_queue);
1710 * ntb_transport_rx_remove - Dequeues enqueued rx packet
1711 * @qp: NTB queue to be freed
1712 * @len: pointer to variable to write enqueued buffers length
1714 * Dequeues unused buffers from receive queue. Should only be used during
1717 * RETURNS: NULL error value on error, or void* for success.
1719 void *ntb_transport_rx_remove(struct ntb_transport_qp *qp, unsigned int *len)
1721 struct ntb_queue_entry *entry;
1724 if (!qp || qp->client_ready)
1727 entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q);
1731 buf = entry->cb_data;
1734 ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry, &qp->rx_free_q);
1738 EXPORT_SYMBOL_GPL(ntb_transport_rx_remove);
1741 * ntb_transport_rx_enqueue - Enqueue a new NTB queue entry
1742 * @qp: NTB transport layer queue the entry is to be enqueued on
1743 * @cb: per buffer pointer for callback function to use
1744 * @data: pointer to data buffer that incoming packets will be copied into
1745 * @len: length of the data buffer
1747 * Enqueue a new receive buffer onto the transport queue into which a NTB
1748 * payload can be received into.
1750 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
1752 int ntb_transport_rx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
1755 struct ntb_queue_entry *entry;
1760 entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q);
1764 entry->cb_data = cb;
1768 ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry, &qp->rx_pend_q);
1772 EXPORT_SYMBOL_GPL(ntb_transport_rx_enqueue);
1775 * ntb_transport_tx_enqueue - Enqueue a new NTB queue entry
1776 * @qp: NTB transport layer queue the entry is to be enqueued on
1777 * @cb: per buffer pointer for callback function to use
1778 * @data: pointer to data buffer that will be sent
1779 * @len: length of the data buffer
1781 * Enqueue a new transmit buffer onto the transport queue from which a NTB
1782 * payload will be transmitted. This assumes that a lock is being held to
1783 * serialize access to the qp.
1785 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
1787 int ntb_transport_tx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
1790 struct ntb_queue_entry *entry;
1793 if (!qp || !qp->link_is_up || !len)
1796 entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
1798 qp->tx_err_no_buf++;
1802 entry->cb_data = cb;
1807 rc = ntb_process_tx(qp, entry);
1809 ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
1814 EXPORT_SYMBOL_GPL(ntb_transport_tx_enqueue);
1817 * ntb_transport_link_up - Notify NTB transport of client readiness to use queue
1818 * @qp: NTB transport layer queue to be enabled
1820 * Notify NTB transport layer of client readiness to use queue
1822 void ntb_transport_link_up(struct ntb_transport_qp *qp)
1827 qp->client_ready = true;
1829 if (qp->transport->link_is_up)
1830 schedule_delayed_work(&qp->link_work, 0);
1832 EXPORT_SYMBOL_GPL(ntb_transport_link_up);
1835 * ntb_transport_link_down - Notify NTB transport to no longer enqueue data
1836 * @qp: NTB transport layer queue to be disabled
1838 * Notify NTB transport layer of client's desire to no longer receive data on
1839 * transport queue specified. It is the client's responsibility to ensure all
1840 * entries on queue are purged or otherwise handled appropriately.
1842 void ntb_transport_link_down(struct ntb_transport_qp *qp)
1844 struct pci_dev *pdev;
1850 pdev = qp->ndev->pdev;
1851 qp->client_ready = false;
1853 val = ntb_spad_read(qp->ndev, QP_LINKS);
1855 ntb_peer_spad_write(qp->ndev, QP_LINKS,
1856 val & ~BIT(qp->qp_num));
1859 ntb_send_link_down(qp);
1861 cancel_delayed_work_sync(&qp->link_work);
1863 EXPORT_SYMBOL_GPL(ntb_transport_link_down);
1866 * ntb_transport_link_query - Query transport link state
1867 * @qp: NTB transport layer queue to be queried
1869 * Query connectivity to the remote system of the NTB transport queue
1871 * RETURNS: true for link up or false for link down
1873 bool ntb_transport_link_query(struct ntb_transport_qp *qp)
1878 return qp->link_is_up;
1880 EXPORT_SYMBOL_GPL(ntb_transport_link_query);
1883 * ntb_transport_qp_num - Query the qp number
1884 * @qp: NTB transport layer queue to be queried
1886 * Query qp number of the NTB transport queue
1888 * RETURNS: a zero based number specifying the qp number
1890 unsigned char ntb_transport_qp_num(struct ntb_transport_qp *qp)
1897 EXPORT_SYMBOL_GPL(ntb_transport_qp_num);
1900 * ntb_transport_max_size - Query the max payload size of a qp
1901 * @qp: NTB transport layer queue to be queried
1903 * Query the maximum payload size permissible on the given qp
1905 * RETURNS: the max payload size of a qp
1907 unsigned int ntb_transport_max_size(struct ntb_transport_qp *qp)
1915 return qp->tx_max_frame - sizeof(struct ntb_payload_header);
1917 /* If DMA engine usage is possible, try to find the max size for that */
1918 max = qp->tx_max_frame - sizeof(struct ntb_payload_header);
1919 max -= max % (1 << qp->dma_chan->device->copy_align);
1923 EXPORT_SYMBOL_GPL(ntb_transport_max_size);
1925 static void ntb_transport_doorbell_callback(void *data, int vector)
1927 struct ntb_transport_ctx *nt = data;
1928 struct ntb_transport_qp *qp;
1930 unsigned int qp_num;
1932 db_bits = (nt->qp_bitmap & ~nt->qp_bitmap_free &
1933 ntb_db_vector_mask(nt->ndev, vector));
1936 qp_num = __ffs(db_bits);
1937 qp = &nt->qp_vec[qp_num];
1939 tasklet_schedule(&qp->rxc_db_work);
1941 db_bits &= ~BIT_ULL(qp_num);
1945 static const struct ntb_ctx_ops ntb_transport_ops = {
1946 .link_event = ntb_transport_event_callback,
1947 .db_event = ntb_transport_doorbell_callback,
1950 static struct ntb_client ntb_transport_client = {
1952 .probe = ntb_transport_probe,
1953 .remove = ntb_transport_free,
1957 static int __init ntb_transport_init(void)
1961 pr_info("%s, version %s\n", NTB_TRANSPORT_DESC, NTB_TRANSPORT_VER);
1963 if (debugfs_initialized())
1964 nt_debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
1966 rc = bus_register(&ntb_transport_bus);
1970 rc = ntb_register_client(&ntb_transport_client);
1977 bus_unregister(&ntb_transport_bus);
1979 debugfs_remove_recursive(nt_debugfs_dir);
1982 module_init(ntb_transport_init);
1984 static void __exit ntb_transport_exit(void)
1986 debugfs_remove_recursive(nt_debugfs_dir);
1988 ntb_unregister_client(&ntb_transport_client);
1989 bus_unregister(&ntb_transport_bus);
1991 module_exit(ntb_transport_exit);