xref: /openbmc/linux/drivers/ntb/test/ntb_perf.c (revision 23c2b932)
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) 2015 Intel Corporation. All rights reserved.
8  *
9  *   This program is free software; you can redistribute it and/or modify
10  *   it under the terms of version 2 of the GNU General Public License as
11  *   published by the Free Software Foundation.
12  *
13  *   BSD LICENSE
14  *
15  *   Copyright(c) 2015 Intel Corporation. All rights reserved.
16  *
17  *   Redistribution and use in source and binary forms, with or without
18  *   modification, are permitted provided that the following conditions
19  *   are met:
20  *
21  *     * Redistributions of source code must retain the above copyright
22  *       notice, this list of conditions and the following disclaimer.
23  *     * Redistributions in binary form must reproduce the above copy
24  *       notice, this list of conditions and the following disclaimer in
25  *       the documentation and/or other materials provided with the
26  *       distribution.
27  *     * Neither the name of Intel Corporation nor the names of its
28  *       contributors may be used to endorse or promote products derived
29  *       from this software without specific prior written permission.
30  *
31  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
34  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
36  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
37  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
38  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
39  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
40  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
41  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
42  *
43  *   PCIe NTB Perf Linux driver
44  */
45 
46 #include <linux/init.h>
47 #include <linux/kernel.h>
48 #include <linux/module.h>
49 #include <linux/kthread.h>
50 #include <linux/time.h>
51 #include <linux/timer.h>
52 #include <linux/dma-mapping.h>
53 #include <linux/pci.h>
54 #include <linux/slab.h>
55 #include <linux/spinlock.h>
56 #include <linux/debugfs.h>
57 #include <linux/dmaengine.h>
58 #include <linux/delay.h>
59 #include <linux/sizes.h>
60 #include <linux/ntb.h>
61 
62 #define DRIVER_NAME		"ntb_perf"
63 #define DRIVER_DESCRIPTION	"PCIe NTB Performance Measurement Tool"
64 
65 #define DRIVER_LICENSE		"Dual BSD/GPL"
66 #define DRIVER_VERSION		"1.0"
67 #define DRIVER_AUTHOR		"Dave Jiang <dave.jiang@intel.com>"
68 
69 #define PERF_LINK_DOWN_TIMEOUT	10
70 #define PERF_VERSION		0xffff0001
71 #define MAX_THREADS		32
72 #define MAX_TEST_SIZE		SZ_1M
73 #define MAX_SRCS		32
74 #define DMA_OUT_RESOURCE_TO	50
75 #define DMA_RETRIES		20
76 #define SZ_4G			(1ULL << 32)
77 #define MAX_SEG_ORDER		20 /* no larger than 1M for kmalloc buffer */
78 
79 MODULE_LICENSE(DRIVER_LICENSE);
80 MODULE_VERSION(DRIVER_VERSION);
81 MODULE_AUTHOR(DRIVER_AUTHOR);
82 MODULE_DESCRIPTION(DRIVER_DESCRIPTION);
83 
84 static struct dentry *perf_debugfs_dir;
85 
86 static unsigned int seg_order = 19; /* 512K */
87 module_param(seg_order, uint, 0644);
88 MODULE_PARM_DESC(seg_order, "size order [n^2] of buffer segment for testing");
89 
90 static unsigned int run_order = 32; /* 4G */
91 module_param(run_order, uint, 0644);
92 MODULE_PARM_DESC(run_order, "size order [n^2] of total data to transfer");
93 
94 static bool use_dma; /* default to 0 */
95 module_param(use_dma, bool, 0644);
96 MODULE_PARM_DESC(use_dma, "Using DMA engine to measure performance");
97 
98 struct perf_mw {
99 	phys_addr_t	phys_addr;
100 	resource_size_t	phys_size;
101 	resource_size_t	xlat_align;
102 	resource_size_t	xlat_align_size;
103 	void __iomem	*vbase;
104 	size_t		xlat_size;
105 	size_t		buf_size;
106 	void		*virt_addr;
107 	dma_addr_t	dma_addr;
108 };
109 
110 struct perf_ctx;
111 
112 struct pthr_ctx {
113 	struct task_struct	*thread;
114 	struct perf_ctx		*perf;
115 	atomic_t		dma_sync;
116 	struct dma_chan		*dma_chan;
117 	int			dma_prep_err;
118 	int			src_idx;
119 	void			*srcs[MAX_SRCS];
120 };
121 
122 struct perf_ctx {
123 	struct ntb_dev		*ntb;
124 	spinlock_t		db_lock;
125 	struct perf_mw		mw;
126 	bool			link_is_up;
127 	struct work_struct	link_cleanup;
128 	struct delayed_work	link_work;
129 	struct dentry		*debugfs_node_dir;
130 	struct dentry		*debugfs_run;
131 	struct dentry		*debugfs_threads;
132 	u8			perf_threads;
133 	bool			run;
134 	struct pthr_ctx		pthr_ctx[MAX_THREADS];
135 	atomic_t		tsync;
136 };
137 
138 enum {
139 	VERSION = 0,
140 	MW_SZ_HIGH,
141 	MW_SZ_LOW,
142 	SPAD_MSG,
143 	SPAD_ACK,
144 	MAX_SPAD
145 };
146 
147 static void perf_link_event(void *ctx)
148 {
149 	struct perf_ctx *perf = ctx;
150 
151 	if (ntb_link_is_up(perf->ntb, NULL, NULL) == 1)
152 		schedule_delayed_work(&perf->link_work, 2*HZ);
153 	else
154 		schedule_work(&perf->link_cleanup);
155 }
156 
157 static void perf_db_event(void *ctx, int vec)
158 {
159 	struct perf_ctx *perf = ctx;
160 	u64 db_bits, db_mask;
161 
162 	db_mask = ntb_db_vector_mask(perf->ntb, vec);
163 	db_bits = ntb_db_read(perf->ntb);
164 
165 	dev_dbg(&perf->ntb->dev, "doorbell vec %d mask %#llx bits %#llx\n",
166 		vec, db_mask, db_bits);
167 }
168 
169 static const struct ntb_ctx_ops perf_ops = {
170 	.link_event = perf_link_event,
171 	.db_event = perf_db_event,
172 };
173 
174 static void perf_copy_callback(void *data)
175 {
176 	struct pthr_ctx *pctx = data;
177 
178 	atomic_dec(&pctx->dma_sync);
179 }
180 
181 static ssize_t perf_copy(struct pthr_ctx *pctx, char __iomem *dst,
182 			 char *src, size_t size)
183 {
184 	struct perf_ctx *perf = pctx->perf;
185 	struct dma_async_tx_descriptor *txd;
186 	struct dma_chan *chan = pctx->dma_chan;
187 	struct dma_device *device;
188 	struct dmaengine_unmap_data *unmap;
189 	dma_cookie_t cookie;
190 	size_t src_off, dst_off;
191 	struct perf_mw *mw = &perf->mw;
192 	void __iomem *vbase;
193 	void __iomem *dst_vaddr;
194 	dma_addr_t dst_phys;
195 	int retries = 0;
196 
197 	if (!use_dma) {
198 		memcpy_toio(dst, src, size);
199 		return size;
200 	}
201 
202 	if (!chan) {
203 		dev_err(&perf->ntb->dev, "DMA engine does not exist\n");
204 		return -EINVAL;
205 	}
206 
207 	device = chan->device;
208 	src_off = (uintptr_t)src & ~PAGE_MASK;
209 	dst_off = (uintptr_t __force)dst & ~PAGE_MASK;
210 
211 	if (!is_dma_copy_aligned(device, src_off, dst_off, size))
212 		return -ENODEV;
213 
214 	vbase = mw->vbase;
215 	dst_vaddr = dst;
216 	dst_phys = mw->phys_addr + (dst_vaddr - vbase);
217 
218 	unmap = dmaengine_get_unmap_data(device->dev, 1, GFP_NOWAIT);
219 	if (!unmap)
220 		return -ENOMEM;
221 
222 	unmap->len = size;
223 	unmap->addr[0] = dma_map_page(device->dev, virt_to_page(src),
224 				      src_off, size, DMA_TO_DEVICE);
225 	if (dma_mapping_error(device->dev, unmap->addr[0]))
226 		goto err_get_unmap;
227 
228 	unmap->to_cnt = 1;
229 
230 	do {
231 		txd = device->device_prep_dma_memcpy(chan, dst_phys,
232 						     unmap->addr[0],
233 						     size, DMA_PREP_INTERRUPT);
234 		if (!txd) {
235 			set_current_state(TASK_INTERRUPTIBLE);
236 			schedule_timeout(DMA_OUT_RESOURCE_TO);
237 		}
238 	} while (!txd && (++retries < DMA_RETRIES));
239 
240 	if (!txd) {
241 		pctx->dma_prep_err++;
242 		goto err_get_unmap;
243 	}
244 
245 	txd->callback = perf_copy_callback;
246 	txd->callback_param = pctx;
247 	dma_set_unmap(txd, unmap);
248 
249 	cookie = dmaengine_submit(txd);
250 	if (dma_submit_error(cookie))
251 		goto err_set_unmap;
252 
253 	atomic_inc(&pctx->dma_sync);
254 	dma_async_issue_pending(chan);
255 
256 	return size;
257 
258 err_set_unmap:
259 	dmaengine_unmap_put(unmap);
260 err_get_unmap:
261 	dmaengine_unmap_put(unmap);
262 	return 0;
263 }
264 
265 static int perf_move_data(struct pthr_ctx *pctx, char __iomem *dst, char *src,
266 			  u64 buf_size, u64 win_size, u64 total)
267 {
268 	int chunks, total_chunks, i;
269 	int copied_chunks = 0;
270 	u64 copied = 0, result;
271 	char __iomem *tmp = dst;
272 	u64 perf, diff_us;
273 	ktime_t kstart, kstop, kdiff;
274 
275 	chunks = div64_u64(win_size, buf_size);
276 	total_chunks = div64_u64(total, buf_size);
277 	kstart = ktime_get();
278 
279 	for (i = 0; i < total_chunks; i++) {
280 		result = perf_copy(pctx, tmp, src, buf_size);
281 		copied += result;
282 		copied_chunks++;
283 		if (copied_chunks == chunks) {
284 			tmp = dst;
285 			copied_chunks = 0;
286 		} else
287 			tmp += buf_size;
288 
289 		/* Probably should schedule every 4GB to prevent soft hang. */
290 		if (((copied % SZ_4G) == 0) && !use_dma) {
291 			set_current_state(TASK_INTERRUPTIBLE);
292 			schedule_timeout(1);
293 		}
294 	}
295 
296 	if (use_dma) {
297 		pr_info("%s: All DMA descriptors submitted\n", current->comm);
298 		while (atomic_read(&pctx->dma_sync) != 0)
299 			msleep(20);
300 	}
301 
302 	kstop = ktime_get();
303 	kdiff = ktime_sub(kstop, kstart);
304 	diff_us = ktime_to_us(kdiff);
305 
306 	pr_info("%s: copied %llu bytes\n", current->comm, copied);
307 
308 	pr_info("%s: lasted %llu usecs\n", current->comm, diff_us);
309 
310 	perf = div64_u64(copied, diff_us);
311 
312 	pr_info("%s: MBytes/s: %llu\n", current->comm, perf);
313 
314 	return 0;
315 }
316 
317 static bool perf_dma_filter_fn(struct dma_chan *chan, void *node)
318 {
319 	return dev_to_node(&chan->dev->device) == (int)(unsigned long)node;
320 }
321 
322 static int ntb_perf_thread(void *data)
323 {
324 	struct pthr_ctx *pctx = data;
325 	struct perf_ctx *perf = pctx->perf;
326 	struct pci_dev *pdev = perf->ntb->pdev;
327 	struct perf_mw *mw = &perf->mw;
328 	char __iomem *dst;
329 	u64 win_size, buf_size, total;
330 	void *src;
331 	int rc, node, i;
332 	struct dma_chan *dma_chan = NULL;
333 
334 	pr_info("kthread %s starting...\n", current->comm);
335 
336 	node = dev_to_node(&pdev->dev);
337 
338 	if (use_dma && !pctx->dma_chan) {
339 		dma_cap_mask_t dma_mask;
340 
341 		dma_cap_zero(dma_mask);
342 		dma_cap_set(DMA_MEMCPY, dma_mask);
343 		dma_chan = dma_request_channel(dma_mask, perf_dma_filter_fn,
344 					       (void *)(unsigned long)node);
345 		if (!dma_chan) {
346 			pr_warn("%s: cannot acquire DMA channel, quitting\n",
347 				current->comm);
348 			return -ENODEV;
349 		}
350 		pctx->dma_chan = dma_chan;
351 	}
352 
353 	for (i = 0; i < MAX_SRCS; i++) {
354 		pctx->srcs[i] = kmalloc_node(MAX_TEST_SIZE, GFP_KERNEL, node);
355 		if (!pctx->srcs[i]) {
356 			rc = -ENOMEM;
357 			goto err;
358 		}
359 	}
360 
361 	win_size = mw->phys_size;
362 	buf_size = 1ULL << seg_order;
363 	total = 1ULL << run_order;
364 
365 	if (buf_size > MAX_TEST_SIZE)
366 		buf_size = MAX_TEST_SIZE;
367 
368 	dst = (char __iomem *)mw->vbase;
369 
370 	atomic_inc(&perf->tsync);
371 	while (atomic_read(&perf->tsync) != perf->perf_threads)
372 		schedule();
373 
374 	src = pctx->srcs[pctx->src_idx];
375 	pctx->src_idx = (pctx->src_idx + 1) & (MAX_SRCS - 1);
376 
377 	rc = perf_move_data(pctx, dst, src, buf_size, win_size, total);
378 
379 	atomic_dec(&perf->tsync);
380 
381 	if (rc < 0) {
382 		pr_err("%s: failed\n", current->comm);
383 		rc = -ENXIO;
384 		goto err;
385 	}
386 
387 	for (i = 0; i < MAX_SRCS; i++) {
388 		kfree(pctx->srcs[i]);
389 		pctx->srcs[i] = NULL;
390 	}
391 
392 	return 0;
393 
394 err:
395 	for (i = 0; i < MAX_SRCS; i++) {
396 		kfree(pctx->srcs[i]);
397 		pctx->srcs[i] = NULL;
398 	}
399 
400 	if (dma_chan) {
401 		dma_release_channel(dma_chan);
402 		pctx->dma_chan = NULL;
403 	}
404 
405 	return rc;
406 }
407 
408 static void perf_free_mw(struct perf_ctx *perf)
409 {
410 	struct perf_mw *mw = &perf->mw;
411 	struct pci_dev *pdev = perf->ntb->pdev;
412 
413 	if (!mw->virt_addr)
414 		return;
415 
416 	ntb_mw_clear_trans(perf->ntb, 0);
417 	dma_free_coherent(&pdev->dev, mw->buf_size,
418 			  mw->virt_addr, mw->dma_addr);
419 	mw->xlat_size = 0;
420 	mw->buf_size = 0;
421 	mw->virt_addr = NULL;
422 }
423 
424 static int perf_set_mw(struct perf_ctx *perf, resource_size_t size)
425 {
426 	struct perf_mw *mw = &perf->mw;
427 	size_t xlat_size, buf_size;
428 	int rc;
429 
430 	if (!size)
431 		return -EINVAL;
432 
433 	xlat_size = round_up(size, mw->xlat_align_size);
434 	buf_size = round_up(size, mw->xlat_align);
435 
436 	if (mw->xlat_size == xlat_size)
437 		return 0;
438 
439 	if (mw->buf_size)
440 		perf_free_mw(perf);
441 
442 	mw->xlat_size = xlat_size;
443 	mw->buf_size = buf_size;
444 
445 	mw->virt_addr = dma_alloc_coherent(&perf->ntb->pdev->dev, buf_size,
446 					   &mw->dma_addr, GFP_KERNEL);
447 	if (!mw->virt_addr) {
448 		mw->xlat_size = 0;
449 		mw->buf_size = 0;
450 	}
451 
452 	rc = ntb_mw_set_trans(perf->ntb, 0, mw->dma_addr, mw->xlat_size);
453 	if (rc) {
454 		dev_err(&perf->ntb->dev, "Unable to set mw0 translation\n");
455 		perf_free_mw(perf);
456 		return -EIO;
457 	}
458 
459 	return 0;
460 }
461 
462 static void perf_link_work(struct work_struct *work)
463 {
464 	struct perf_ctx *perf =
465 		container_of(work, struct perf_ctx, link_work.work);
466 	struct ntb_dev *ndev = perf->ntb;
467 	struct pci_dev *pdev = ndev->pdev;
468 	u32 val;
469 	u64 size;
470 	int rc;
471 
472 	dev_dbg(&perf->ntb->pdev->dev, "%s called\n", __func__);
473 
474 	size = perf->mw.phys_size;
475 	ntb_peer_spad_write(ndev, MW_SZ_HIGH, upper_32_bits(size));
476 	ntb_peer_spad_write(ndev, MW_SZ_LOW, lower_32_bits(size));
477 	ntb_peer_spad_write(ndev, VERSION, PERF_VERSION);
478 
479 	/* now read what peer wrote */
480 	val = ntb_spad_read(ndev, VERSION);
481 	if (val != PERF_VERSION) {
482 		dev_dbg(&pdev->dev, "Remote version = %#x\n", val);
483 		goto out;
484 	}
485 
486 	val = ntb_spad_read(ndev, MW_SZ_HIGH);
487 	size = (u64)val << 32;
488 
489 	val = ntb_spad_read(ndev, MW_SZ_LOW);
490 	size |= val;
491 
492 	dev_dbg(&pdev->dev, "Remote MW size = %#llx\n", size);
493 
494 	rc = perf_set_mw(perf, size);
495 	if (rc)
496 		goto out1;
497 
498 	perf->link_is_up = true;
499 
500 	return;
501 
502 out1:
503 	perf_free_mw(perf);
504 
505 out:
506 	if (ntb_link_is_up(ndev, NULL, NULL) == 1)
507 		schedule_delayed_work(&perf->link_work,
508 				      msecs_to_jiffies(PERF_LINK_DOWN_TIMEOUT));
509 }
510 
511 static void perf_link_cleanup(struct work_struct *work)
512 {
513 	struct perf_ctx *perf = container_of(work,
514 					     struct perf_ctx,
515 					     link_cleanup);
516 
517 	dev_dbg(&perf->ntb->pdev->dev, "%s called\n", __func__);
518 
519 	if (!perf->link_is_up)
520 		cancel_delayed_work_sync(&perf->link_work);
521 }
522 
523 static int perf_setup_mw(struct ntb_dev *ntb, struct perf_ctx *perf)
524 {
525 	struct perf_mw *mw;
526 	int rc;
527 
528 	mw = &perf->mw;
529 
530 	rc = ntb_mw_get_range(ntb, 0, &mw->phys_addr, &mw->phys_size,
531 			      &mw->xlat_align, &mw->xlat_align_size);
532 	if (rc)
533 		return rc;
534 
535 	perf->mw.vbase = ioremap_wc(mw->phys_addr, mw->phys_size);
536 	if (!mw->vbase)
537 		return -ENOMEM;
538 
539 	return 0;
540 }
541 
542 static ssize_t debugfs_run_read(struct file *filp, char __user *ubuf,
543 				size_t count, loff_t *offp)
544 {
545 	struct perf_ctx *perf = filp->private_data;
546 	char *buf;
547 	ssize_t ret, out_offset;
548 
549 	if (!perf)
550 		return 0;
551 
552 	buf = kmalloc(64, GFP_KERNEL);
553 	if (!buf)
554 		return -ENOMEM;
555 	out_offset = snprintf(buf, 64, "%d\n", perf->run);
556 	ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
557 	kfree(buf);
558 
559 	return ret;
560 }
561 
562 static void threads_cleanup(struct perf_ctx *perf)
563 {
564 	struct pthr_ctx *pctx;
565 	int i;
566 
567 	perf->run = false;
568 	for (i = 0; i < MAX_THREADS; i++) {
569 		pctx = &perf->pthr_ctx[i];
570 		if (pctx->thread) {
571 			kthread_stop(pctx->thread);
572 			pctx->thread = NULL;
573 		}
574 	}
575 }
576 
577 static ssize_t debugfs_run_write(struct file *filp, const char __user *ubuf,
578 				 size_t count, loff_t *offp)
579 {
580 	struct perf_ctx *perf = filp->private_data;
581 	int node, i;
582 
583 	if (!perf->link_is_up)
584 		return 0;
585 
586 	if (perf->perf_threads == 0)
587 		return 0;
588 
589 	if (atomic_read(&perf->tsync) == 0)
590 		perf->run = false;
591 
592 	if (perf->run)
593 		threads_cleanup(perf);
594 	else {
595 		perf->run = true;
596 
597 		if (perf->perf_threads > MAX_THREADS) {
598 			perf->perf_threads = MAX_THREADS;
599 			pr_info("Reset total threads to: %u\n", MAX_THREADS);
600 		}
601 
602 		/* no greater than 1M */
603 		if (seg_order > MAX_SEG_ORDER) {
604 			seg_order = MAX_SEG_ORDER;
605 			pr_info("Fix seg_order to %u\n", seg_order);
606 		}
607 
608 		if (run_order < seg_order) {
609 			run_order = seg_order;
610 			pr_info("Fix run_order to %u\n", run_order);
611 		}
612 
613 		node = dev_to_node(&perf->ntb->pdev->dev);
614 		/* launch kernel thread */
615 		for (i = 0; i < perf->perf_threads; i++) {
616 			struct pthr_ctx *pctx;
617 
618 			pctx = &perf->pthr_ctx[i];
619 			atomic_set(&pctx->dma_sync, 0);
620 			pctx->perf = perf;
621 			pctx->thread =
622 				kthread_create_on_node(ntb_perf_thread,
623 						       (void *)pctx,
624 						       node, "ntb_perf %d", i);
625 			if (IS_ERR(pctx->thread)) {
626 				pctx->thread = NULL;
627 				goto err;
628 			} else
629 				wake_up_process(pctx->thread);
630 
631 			if (perf->run == false)
632 				return -ENXIO;
633 		}
634 
635 	}
636 
637 	return count;
638 
639 err:
640 	threads_cleanup(perf);
641 	return -ENXIO;
642 }
643 
644 static const struct file_operations ntb_perf_debugfs_run = {
645 	.owner = THIS_MODULE,
646 	.open = simple_open,
647 	.read = debugfs_run_read,
648 	.write = debugfs_run_write,
649 };
650 
651 static int perf_debugfs_setup(struct perf_ctx *perf)
652 {
653 	struct pci_dev *pdev = perf->ntb->pdev;
654 
655 	if (!debugfs_initialized())
656 		return -ENODEV;
657 
658 	if (!perf_debugfs_dir) {
659 		perf_debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
660 		if (!perf_debugfs_dir)
661 			return -ENODEV;
662 	}
663 
664 	perf->debugfs_node_dir = debugfs_create_dir(pci_name(pdev),
665 						    perf_debugfs_dir);
666 	if (!perf->debugfs_node_dir)
667 		return -ENODEV;
668 
669 	perf->debugfs_run = debugfs_create_file("run", S_IRUSR | S_IWUSR,
670 						perf->debugfs_node_dir, perf,
671 						&ntb_perf_debugfs_run);
672 	if (!perf->debugfs_run)
673 		return -ENODEV;
674 
675 	perf->debugfs_threads = debugfs_create_u8("threads", S_IRUSR | S_IWUSR,
676 						  perf->debugfs_node_dir,
677 						  &perf->perf_threads);
678 	if (!perf->debugfs_threads)
679 		return -ENODEV;
680 
681 	return 0;
682 }
683 
684 static int perf_probe(struct ntb_client *client, struct ntb_dev *ntb)
685 {
686 	struct pci_dev *pdev = ntb->pdev;
687 	struct perf_ctx *perf;
688 	int node;
689 	int rc = 0;
690 
691 	node = dev_to_node(&pdev->dev);
692 
693 	perf = kzalloc_node(sizeof(*perf), GFP_KERNEL, node);
694 	if (!perf) {
695 		rc = -ENOMEM;
696 		goto err_perf;
697 	}
698 
699 	perf->ntb = ntb;
700 	perf->perf_threads = 1;
701 	atomic_set(&perf->tsync, 0);
702 	perf->run = false;
703 	spin_lock_init(&perf->db_lock);
704 	perf_setup_mw(ntb, perf);
705 	INIT_DELAYED_WORK(&perf->link_work, perf_link_work);
706 	INIT_WORK(&perf->link_cleanup, perf_link_cleanup);
707 
708 	rc = ntb_set_ctx(ntb, perf, &perf_ops);
709 	if (rc)
710 		goto err_ctx;
711 
712 	perf->link_is_up = false;
713 	ntb_link_enable(ntb, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
714 	ntb_link_event(ntb);
715 
716 	rc = perf_debugfs_setup(perf);
717 	if (rc)
718 		goto err_ctx;
719 
720 	return 0;
721 
722 err_ctx:
723 	cancel_delayed_work_sync(&perf->link_work);
724 	cancel_work_sync(&perf->link_cleanup);
725 	kfree(perf);
726 err_perf:
727 	return rc;
728 }
729 
730 static void perf_remove(struct ntb_client *client, struct ntb_dev *ntb)
731 {
732 	struct perf_ctx *perf = ntb->ctx;
733 	int i;
734 
735 	dev_dbg(&perf->ntb->dev, "%s called\n", __func__);
736 
737 	cancel_delayed_work_sync(&perf->link_work);
738 	cancel_work_sync(&perf->link_cleanup);
739 
740 	ntb_clear_ctx(ntb);
741 	ntb_link_disable(ntb);
742 
743 	debugfs_remove_recursive(perf_debugfs_dir);
744 	perf_debugfs_dir = NULL;
745 
746 	if (use_dma) {
747 		for (i = 0; i < MAX_THREADS; i++) {
748 			struct pthr_ctx *pctx = &perf->pthr_ctx[i];
749 
750 			if (pctx->dma_chan)
751 				dma_release_channel(pctx->dma_chan);
752 		}
753 	}
754 
755 	kfree(perf);
756 }
757 
758 static struct ntb_client perf_client = {
759 	.ops = {
760 		.probe = perf_probe,
761 		.remove = perf_remove,
762 	},
763 };
764 module_ntb_client(perf_client);
765