xref: /openbmc/linux/drivers/ntb/test/ntb_perf.c (revision 6d99a79c)
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  *   Copyright(c) 2017 T-Platforms. All Rights Reserved.
9  *
10  *   This program is free software; you can redistribute it and/or modify
11  *   it under the terms of version 2 of the GNU General Public License as
12  *   published by the Free Software Foundation.
13  *
14  *   BSD LICENSE
15  *
16  *   Copyright(c) 2015 Intel Corporation. All rights reserved.
17  *   Copyright(c) 2017 T-Platforms. All Rights Reserved.
18  *
19  *   Redistribution and use in source and binary forms, with or without
20  *   modification, are permitted provided that the following conditions
21  *   are met:
22  *
23  *     * Redistributions of source code must retain the above copyright
24  *       notice, this list of conditions and the following disclaimer.
25  *     * Redistributions in binary form must reproduce the above copy
26  *       notice, this list of conditions and the following disclaimer in
27  *       the documentation and/or other materials provided with the
28  *       distribution.
29  *     * Neither the name of Intel Corporation nor the names of its
30  *       contributors may be used to endorse or promote products derived
31  *       from this software without specific prior written permission.
32  *
33  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
34  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
35  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
36  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
37  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
38  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
39  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
40  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
41  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
42  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
43  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
44  *
45  * PCIe NTB Perf Linux driver
46  */
47 
48 /*
49  * How to use this tool, by example.
50  *
51  * Assuming $DBG_DIR is something like:
52  * '/sys/kernel/debug/ntb_perf/0000:00:03.0'
53  * Suppose aside from local device there is at least one remote device
54  * connected to NTB with index 0.
55  *-----------------------------------------------------------------------------
56  * Eg: install driver with specified chunk/total orders and dma-enabled flag
57  *
58  * root@self# insmod ntb_perf.ko chunk_order=19 total_order=28 use_dma
59  *-----------------------------------------------------------------------------
60  * Eg: check NTB ports (index) and MW mapping information
61  *
62  * root@self# cat $DBG_DIR/info
63  *-----------------------------------------------------------------------------
64  * Eg: start performance test with peer (index 0) and get the test metrics
65  *
66  * root@self# echo 0 > $DBG_DIR/run
67  * root@self# cat $DBG_DIR/run
68  */
69 
70 #include <linux/init.h>
71 #include <linux/kernel.h>
72 #include <linux/module.h>
73 #include <linux/sched.h>
74 #include <linux/wait.h>
75 #include <linux/dma-mapping.h>
76 #include <linux/dmaengine.h>
77 #include <linux/pci.h>
78 #include <linux/ktime.h>
79 #include <linux/slab.h>
80 #include <linux/delay.h>
81 #include <linux/sizes.h>
82 #include <linux/workqueue.h>
83 #include <linux/debugfs.h>
84 #include <linux/random.h>
85 #include <linux/ntb.h>
86 
87 #define DRIVER_NAME		"ntb_perf"
88 #define DRIVER_VERSION		"2.0"
89 
90 MODULE_LICENSE("Dual BSD/GPL");
91 MODULE_VERSION(DRIVER_VERSION);
92 MODULE_AUTHOR("Dave Jiang <dave.jiang@intel.com>");
93 MODULE_DESCRIPTION("PCIe NTB Performance Measurement Tool");
94 
95 #define MAX_THREADS_CNT		32
96 #define DEF_THREADS_CNT		1
97 #define MAX_CHUNK_SIZE		SZ_1M
98 #define MAX_CHUNK_ORDER		20 /* no larger than 1M */
99 
100 #define DMA_TRIES		100
101 #define DMA_MDELAY		10
102 
103 #define MSG_TRIES		500
104 #define MSG_UDELAY_LOW		1000
105 #define MSG_UDELAY_HIGH		2000
106 
107 #define PERF_BUF_LEN 1024
108 
109 static unsigned long max_mw_size;
110 module_param(max_mw_size, ulong, 0644);
111 MODULE_PARM_DESC(max_mw_size, "Upper limit of memory window size");
112 
113 static unsigned char chunk_order = 19; /* 512K */
114 module_param(chunk_order, byte, 0644);
115 MODULE_PARM_DESC(chunk_order, "Data chunk order [2^n] to transfer");
116 
117 static unsigned char total_order = 30; /* 1G */
118 module_param(total_order, byte, 0644);
119 MODULE_PARM_DESC(total_order, "Total data order [2^n] to transfer");
120 
121 static bool use_dma; /* default to 0 */
122 module_param(use_dma, bool, 0644);
123 MODULE_PARM_DESC(use_dma, "Use DMA engine to measure performance");
124 
125 /*==============================================================================
126  *                         Perf driver data definition
127  *==============================================================================
128  */
129 
130 enum perf_cmd {
131 	PERF_CMD_INVAL = -1,/* invalid spad command */
132 	PERF_CMD_SSIZE = 0, /* send out buffer size */
133 	PERF_CMD_RSIZE = 1, /* recv in  buffer size */
134 	PERF_CMD_SXLAT = 2, /* send in  buffer xlat */
135 	PERF_CMD_RXLAT = 3, /* recv out buffer xlat */
136 	PERF_CMD_CLEAR = 4, /* clear allocated memory */
137 	PERF_STS_DONE  = 5, /* init is done */
138 	PERF_STS_LNKUP = 6, /* link up state flag */
139 };
140 
141 struct perf_ctx;
142 
143 struct perf_peer {
144 	struct perf_ctx	*perf;
145 	int pidx;
146 	int gidx;
147 
148 	/* Outbound MW params */
149 	u64 outbuf_xlat;
150 	resource_size_t outbuf_size;
151 	void __iomem *outbuf;
152 
153 	/* Inbound MW params */
154 	dma_addr_t inbuf_xlat;
155 	resource_size_t inbuf_size;
156 	void		*inbuf;
157 
158 	/* NTB connection setup service */
159 	struct work_struct	service;
160 	unsigned long		sts;
161 };
162 #define to_peer_service(__work) \
163 	container_of(__work, struct perf_peer, service)
164 
165 struct perf_thread {
166 	struct perf_ctx *perf;
167 	int tidx;
168 
169 	/* DMA-based test sync parameters */
170 	atomic_t dma_sync;
171 	wait_queue_head_t dma_wait;
172 	struct dma_chan *dma_chan;
173 
174 	/* Data source and measured statistics */
175 	void *src;
176 	u64 copied;
177 	ktime_t duration;
178 	int status;
179 	struct work_struct work;
180 };
181 #define to_thread_work(__work) \
182 	container_of(__work, struct perf_thread, work)
183 
184 struct perf_ctx {
185 	struct ntb_dev *ntb;
186 
187 	/* Global device index and peers descriptors */
188 	int gidx;
189 	int pcnt;
190 	struct perf_peer *peers;
191 
192 	/* Performance measuring work-threads interface */
193 	unsigned long busy_flag;
194 	wait_queue_head_t twait;
195 	atomic_t tsync;
196 	u8 tcnt;
197 	struct perf_peer *test_peer;
198 	struct perf_thread threads[MAX_THREADS_CNT];
199 
200 	/* Scratchpad/Message IO operations */
201 	int (*cmd_send)(struct perf_peer *peer, enum perf_cmd cmd, u64 data);
202 	int (*cmd_recv)(struct perf_ctx *perf, int *pidx, enum perf_cmd *cmd,
203 			u64 *data);
204 
205 	struct dentry *dbgfs_dir;
206 };
207 
208 /*
209  * Scratchpads-base commands interface
210  */
211 #define PERF_SPAD_CNT(_pcnt) \
212 	(3*((_pcnt) + 1))
213 #define PERF_SPAD_CMD(_gidx) \
214 	(3*(_gidx))
215 #define PERF_SPAD_LDATA(_gidx) \
216 	(3*(_gidx) + 1)
217 #define PERF_SPAD_HDATA(_gidx) \
218 	(3*(_gidx) + 2)
219 #define PERF_SPAD_NOTIFY(_gidx) \
220 	(BIT_ULL(_gidx))
221 
222 /*
223  * Messages-base commands interface
224  */
225 #define PERF_MSG_CNT		3
226 #define PERF_MSG_CMD		0
227 #define PERF_MSG_LDATA		1
228 #define PERF_MSG_HDATA		2
229 
230 /*==============================================================================
231  *                           Static data declarations
232  *==============================================================================
233  */
234 
235 static struct dentry *perf_dbgfs_topdir;
236 
237 static struct workqueue_struct *perf_wq __read_mostly;
238 
239 /*==============================================================================
240  *                  NTB cross-link commands execution service
241  *==============================================================================
242  */
243 
244 static void perf_terminate_test(struct perf_ctx *perf);
245 
246 static inline bool perf_link_is_up(struct perf_peer *peer)
247 {
248 	u64 link;
249 
250 	link = ntb_link_is_up(peer->perf->ntb, NULL, NULL);
251 	return !!(link & BIT_ULL_MASK(peer->pidx));
252 }
253 
254 static int perf_spad_cmd_send(struct perf_peer *peer, enum perf_cmd cmd,
255 			      u64 data)
256 {
257 	struct perf_ctx *perf = peer->perf;
258 	int try;
259 	u32 sts;
260 
261 	dev_dbg(&perf->ntb->dev, "CMD send: %d 0x%llx\n", cmd, data);
262 
263 	/*
264 	 * Perform predefined number of attempts before give up.
265 	 * We are sending the data to the port specific scratchpad, so
266 	 * to prevent a multi-port access race-condition. Additionally
267 	 * there is no need in local locking since only thread-safe
268 	 * service work is using this method.
269 	 */
270 	for (try = 0; try < MSG_TRIES; try++) {
271 		if (!perf_link_is_up(peer))
272 			return -ENOLINK;
273 
274 		sts = ntb_peer_spad_read(perf->ntb, peer->pidx,
275 					 PERF_SPAD_CMD(perf->gidx));
276 		if (sts != PERF_CMD_INVAL) {
277 			usleep_range(MSG_UDELAY_LOW, MSG_UDELAY_HIGH);
278 			continue;
279 		}
280 
281 		ntb_peer_spad_write(perf->ntb, peer->pidx,
282 				    PERF_SPAD_LDATA(perf->gidx),
283 				    lower_32_bits(data));
284 		ntb_peer_spad_write(perf->ntb, peer->pidx,
285 				    PERF_SPAD_HDATA(perf->gidx),
286 				    upper_32_bits(data));
287 		mmiowb();
288 		ntb_peer_spad_write(perf->ntb, peer->pidx,
289 				    PERF_SPAD_CMD(perf->gidx),
290 				    cmd);
291 		mmiowb();
292 		ntb_peer_db_set(perf->ntb, PERF_SPAD_NOTIFY(peer->gidx));
293 
294 		dev_dbg(&perf->ntb->dev, "DB ring peer %#llx\n",
295 			PERF_SPAD_NOTIFY(peer->gidx));
296 
297 		break;
298 	}
299 
300 	return try < MSG_TRIES ? 0 : -EAGAIN;
301 }
302 
303 static int perf_spad_cmd_recv(struct perf_ctx *perf, int *pidx,
304 			      enum perf_cmd *cmd, u64 *data)
305 {
306 	struct perf_peer *peer;
307 	u32 val;
308 
309 	ntb_db_clear(perf->ntb, PERF_SPAD_NOTIFY(perf->gidx));
310 
311 	/*
312 	 * We start scanning all over, since cleared DB may have been set
313 	 * by any peer. Yes, it makes peer with smaller index being
314 	 * serviced with greater priority, but it's convenient for spad
315 	 * and message code unification and simplicity.
316 	 */
317 	for (*pidx = 0; *pidx < perf->pcnt; (*pidx)++) {
318 		peer = &perf->peers[*pidx];
319 
320 		if (!perf_link_is_up(peer))
321 			continue;
322 
323 		val = ntb_spad_read(perf->ntb, PERF_SPAD_CMD(peer->gidx));
324 		if (val == PERF_CMD_INVAL)
325 			continue;
326 
327 		*cmd = val;
328 
329 		val = ntb_spad_read(perf->ntb, PERF_SPAD_LDATA(peer->gidx));
330 		*data = val;
331 
332 		val = ntb_spad_read(perf->ntb, PERF_SPAD_HDATA(peer->gidx));
333 		*data |= (u64)val << 32;
334 
335 		/* Next command can be retrieved from now */
336 		ntb_spad_write(perf->ntb, PERF_SPAD_CMD(peer->gidx),
337 			       PERF_CMD_INVAL);
338 
339 		dev_dbg(&perf->ntb->dev, "CMD recv: %d 0x%llx\n", *cmd, *data);
340 
341 		return 0;
342 	}
343 
344 	return -ENODATA;
345 }
346 
347 static int perf_msg_cmd_send(struct perf_peer *peer, enum perf_cmd cmd,
348 			     u64 data)
349 {
350 	struct perf_ctx *perf = peer->perf;
351 	int try, ret;
352 	u64 outbits;
353 
354 	dev_dbg(&perf->ntb->dev, "CMD send: %d 0x%llx\n", cmd, data);
355 
356 	/*
357 	 * Perform predefined number of attempts before give up. Message
358 	 * registers are free of race-condition problem when accessed
359 	 * from different ports, so we don't need splitting registers
360 	 * by global device index. We also won't have local locking,
361 	 * since the method is used from service work only.
362 	 */
363 	outbits = ntb_msg_outbits(perf->ntb);
364 	for (try = 0; try < MSG_TRIES; try++) {
365 		if (!perf_link_is_up(peer))
366 			return -ENOLINK;
367 
368 		ret = ntb_msg_clear_sts(perf->ntb, outbits);
369 		if (ret)
370 			return ret;
371 
372 		ntb_peer_msg_write(perf->ntb, peer->pidx, PERF_MSG_LDATA,
373 				   lower_32_bits(data));
374 
375 		if (ntb_msg_read_sts(perf->ntb) & outbits) {
376 			usleep_range(MSG_UDELAY_LOW, MSG_UDELAY_HIGH);
377 			continue;
378 		}
379 
380 		ntb_peer_msg_write(perf->ntb, peer->pidx, PERF_MSG_HDATA,
381 				   upper_32_bits(data));
382 		mmiowb();
383 
384 		/* This call shall trigger peer message event */
385 		ntb_peer_msg_write(perf->ntb, peer->pidx, PERF_MSG_CMD, cmd);
386 
387 		break;
388 	}
389 
390 	return try < MSG_TRIES ? 0 : -EAGAIN;
391 }
392 
393 static int perf_msg_cmd_recv(struct perf_ctx *perf, int *pidx,
394 			     enum perf_cmd *cmd, u64 *data)
395 {
396 	u64 inbits;
397 	u32 val;
398 
399 	inbits = ntb_msg_inbits(perf->ntb);
400 
401 	if (hweight64(ntb_msg_read_sts(perf->ntb) & inbits) < 3)
402 		return -ENODATA;
403 
404 	val = ntb_msg_read(perf->ntb, pidx, PERF_MSG_CMD);
405 	*cmd = val;
406 
407 	val = ntb_msg_read(perf->ntb, pidx, PERF_MSG_LDATA);
408 	*data = val;
409 
410 	val = ntb_msg_read(perf->ntb, pidx, PERF_MSG_HDATA);
411 	*data |= (u64)val << 32;
412 
413 	/* Next command can be retrieved from now */
414 	ntb_msg_clear_sts(perf->ntb, inbits);
415 
416 	dev_dbg(&perf->ntb->dev, "CMD recv: %d 0x%llx\n", *cmd, *data);
417 
418 	return 0;
419 }
420 
421 static int perf_cmd_send(struct perf_peer *peer, enum perf_cmd cmd, u64 data)
422 {
423 	struct perf_ctx *perf = peer->perf;
424 
425 	if (cmd == PERF_CMD_SSIZE || cmd == PERF_CMD_SXLAT)
426 		return perf->cmd_send(peer, cmd, data);
427 
428 	dev_err(&perf->ntb->dev, "Send invalid command\n");
429 	return -EINVAL;
430 }
431 
432 static int perf_cmd_exec(struct perf_peer *peer, enum perf_cmd cmd)
433 {
434 	switch (cmd) {
435 	case PERF_CMD_SSIZE:
436 	case PERF_CMD_RSIZE:
437 	case PERF_CMD_SXLAT:
438 	case PERF_CMD_RXLAT:
439 	case PERF_CMD_CLEAR:
440 		break;
441 	default:
442 		dev_err(&peer->perf->ntb->dev, "Exec invalid command\n");
443 		return -EINVAL;
444 	}
445 
446 	/* No need of memory barrier, since bit ops have invernal lock */
447 	set_bit(cmd, &peer->sts);
448 
449 	dev_dbg(&peer->perf->ntb->dev, "CMD exec: %d\n", cmd);
450 
451 	(void)queue_work(system_highpri_wq, &peer->service);
452 
453 	return 0;
454 }
455 
456 static int perf_cmd_recv(struct perf_ctx *perf)
457 {
458 	struct perf_peer *peer;
459 	int ret, pidx, cmd;
460 	u64 data;
461 
462 	while (!(ret = perf->cmd_recv(perf, &pidx, &cmd, &data))) {
463 		peer = &perf->peers[pidx];
464 
465 		switch (cmd) {
466 		case PERF_CMD_SSIZE:
467 			peer->inbuf_size = data;
468 			return perf_cmd_exec(peer, PERF_CMD_RSIZE);
469 		case PERF_CMD_SXLAT:
470 			peer->outbuf_xlat = data;
471 			return perf_cmd_exec(peer, PERF_CMD_RXLAT);
472 		default:
473 			dev_err(&perf->ntb->dev, "Recv invalid command\n");
474 			return -EINVAL;
475 		}
476 	}
477 
478 	/* Return 0 if no data left to process, otherwise an error */
479 	return ret == -ENODATA ? 0 : ret;
480 }
481 
482 static void perf_link_event(void *ctx)
483 {
484 	struct perf_ctx *perf = ctx;
485 	struct perf_peer *peer;
486 	bool lnk_up;
487 	int pidx;
488 
489 	for (pidx = 0; pidx < perf->pcnt; pidx++) {
490 		peer = &perf->peers[pidx];
491 
492 		lnk_up = perf_link_is_up(peer);
493 
494 		if (lnk_up &&
495 		    !test_and_set_bit(PERF_STS_LNKUP, &peer->sts)) {
496 			perf_cmd_exec(peer, PERF_CMD_SSIZE);
497 		} else if (!lnk_up &&
498 			   test_and_clear_bit(PERF_STS_LNKUP, &peer->sts)) {
499 			perf_cmd_exec(peer, PERF_CMD_CLEAR);
500 		}
501 	}
502 }
503 
504 static void perf_db_event(void *ctx, int vec)
505 {
506 	struct perf_ctx *perf = ctx;
507 
508 	dev_dbg(&perf->ntb->dev, "DB vec %d mask %#llx bits %#llx\n", vec,
509 		ntb_db_vector_mask(perf->ntb, vec), ntb_db_read(perf->ntb));
510 
511 	/* Just receive all available commands */
512 	(void)perf_cmd_recv(perf);
513 }
514 
515 static void perf_msg_event(void *ctx)
516 {
517 	struct perf_ctx *perf = ctx;
518 
519 	dev_dbg(&perf->ntb->dev, "Msg status bits %#llx\n",
520 		ntb_msg_read_sts(perf->ntb));
521 
522 	/* Messages are only sent one-by-one */
523 	(void)perf_cmd_recv(perf);
524 }
525 
526 static const struct ntb_ctx_ops perf_ops = {
527 	.link_event = perf_link_event,
528 	.db_event = perf_db_event,
529 	.msg_event = perf_msg_event
530 };
531 
532 static void perf_free_outbuf(struct perf_peer *peer)
533 {
534 	(void)ntb_peer_mw_clear_trans(peer->perf->ntb, peer->pidx, peer->gidx);
535 }
536 
537 static int perf_setup_outbuf(struct perf_peer *peer)
538 {
539 	struct perf_ctx *perf = peer->perf;
540 	int ret;
541 
542 	/* Outbuf size can be unaligned due to custom max_mw_size */
543 	ret = ntb_peer_mw_set_trans(perf->ntb, peer->pidx, peer->gidx,
544 				    peer->outbuf_xlat, peer->outbuf_size);
545 	if (ret) {
546 		dev_err(&perf->ntb->dev, "Failed to set outbuf translation\n");
547 		return ret;
548 	}
549 
550 	/* Initialization is finally done */
551 	set_bit(PERF_STS_DONE, &peer->sts);
552 
553 	return 0;
554 }
555 
556 static void perf_free_inbuf(struct perf_peer *peer)
557 {
558 	if (!peer->inbuf)
559 		return;
560 
561 	(void)ntb_mw_clear_trans(peer->perf->ntb, peer->pidx, peer->gidx);
562 	dma_free_coherent(&peer->perf->ntb->dev, peer->inbuf_size,
563 			  peer->inbuf, peer->inbuf_xlat);
564 	peer->inbuf = NULL;
565 }
566 
567 static int perf_setup_inbuf(struct perf_peer *peer)
568 {
569 	resource_size_t xlat_align, size_align, size_max;
570 	struct perf_ctx *perf = peer->perf;
571 	int ret;
572 
573 	/* Get inbound MW parameters */
574 	ret = ntb_mw_get_align(perf->ntb, peer->pidx, perf->gidx,
575 			       &xlat_align, &size_align, &size_max);
576 	if (ret) {
577 		dev_err(&perf->ntb->dev, "Couldn't get inbuf restrictions\n");
578 		return ret;
579 	}
580 
581 	if (peer->inbuf_size > size_max) {
582 		dev_err(&perf->ntb->dev, "Too big inbuf size %pa > %pa\n",
583 			&peer->inbuf_size, &size_max);
584 		return -EINVAL;
585 	}
586 
587 	peer->inbuf_size = round_up(peer->inbuf_size, size_align);
588 
589 	perf_free_inbuf(peer);
590 
591 	peer->inbuf = dma_alloc_coherent(&perf->ntb->dev, peer->inbuf_size,
592 					 &peer->inbuf_xlat, GFP_KERNEL);
593 	if (!peer->inbuf) {
594 		dev_err(&perf->ntb->dev, "Failed to alloc inbuf of %pa\n",
595 			&peer->inbuf_size);
596 		return -ENOMEM;
597 	}
598 	if (!IS_ALIGNED(peer->inbuf_xlat, xlat_align)) {
599 		dev_err(&perf->ntb->dev, "Unaligned inbuf allocated\n");
600 		goto err_free_inbuf;
601 	}
602 
603 	ret = ntb_mw_set_trans(perf->ntb, peer->pidx, peer->gidx,
604 			       peer->inbuf_xlat, peer->inbuf_size);
605 	if (ret) {
606 		dev_err(&perf->ntb->dev, "Failed to set inbuf translation\n");
607 		goto err_free_inbuf;
608 	}
609 
610 	/*
611 	 * We submit inbuf xlat transmission cmd for execution here to follow
612 	 * the code architecture, even though this method is called from service
613 	 * work itself so the command will be executed right after it returns.
614 	 */
615 	(void)perf_cmd_exec(peer, PERF_CMD_SXLAT);
616 
617 	return 0;
618 
619 err_free_inbuf:
620 	perf_free_inbuf(peer);
621 
622 	return ret;
623 }
624 
625 static void perf_service_work(struct work_struct *work)
626 {
627 	struct perf_peer *peer = to_peer_service(work);
628 
629 	if (test_and_clear_bit(PERF_CMD_SSIZE, &peer->sts))
630 		perf_cmd_send(peer, PERF_CMD_SSIZE, peer->outbuf_size);
631 
632 	if (test_and_clear_bit(PERF_CMD_RSIZE, &peer->sts))
633 		perf_setup_inbuf(peer);
634 
635 	if (test_and_clear_bit(PERF_CMD_SXLAT, &peer->sts))
636 		perf_cmd_send(peer, PERF_CMD_SXLAT, peer->inbuf_xlat);
637 
638 	if (test_and_clear_bit(PERF_CMD_RXLAT, &peer->sts))
639 		perf_setup_outbuf(peer);
640 
641 	if (test_and_clear_bit(PERF_CMD_CLEAR, &peer->sts)) {
642 		clear_bit(PERF_STS_DONE, &peer->sts);
643 		if (test_bit(0, &peer->perf->busy_flag) &&
644 		    peer == peer->perf->test_peer) {
645 			dev_warn(&peer->perf->ntb->dev,
646 				"Freeing while test on-fly\n");
647 			perf_terminate_test(peer->perf);
648 		}
649 		perf_free_outbuf(peer);
650 		perf_free_inbuf(peer);
651 	}
652 }
653 
654 static int perf_init_service(struct perf_ctx *perf)
655 {
656 	u64 mask;
657 
658 	if (ntb_peer_mw_count(perf->ntb) < perf->pcnt + 1) {
659 		dev_err(&perf->ntb->dev, "Not enough memory windows\n");
660 		return -EINVAL;
661 	}
662 
663 	if (ntb_msg_count(perf->ntb) >= PERF_MSG_CNT) {
664 		perf->cmd_send = perf_msg_cmd_send;
665 		perf->cmd_recv = perf_msg_cmd_recv;
666 
667 		dev_dbg(&perf->ntb->dev, "Message service initialized\n");
668 
669 		return 0;
670 	}
671 
672 	dev_dbg(&perf->ntb->dev, "Message service unsupported\n");
673 
674 	mask = GENMASK_ULL(perf->pcnt, 0);
675 	if (ntb_spad_count(perf->ntb) >= PERF_SPAD_CNT(perf->pcnt) &&
676 	    (ntb_db_valid_mask(perf->ntb) & mask) == mask) {
677 		perf->cmd_send = perf_spad_cmd_send;
678 		perf->cmd_recv = perf_spad_cmd_recv;
679 
680 		dev_dbg(&perf->ntb->dev, "Scratchpad service initialized\n");
681 
682 		return 0;
683 	}
684 
685 	dev_dbg(&perf->ntb->dev, "Scratchpad service unsupported\n");
686 
687 	dev_err(&perf->ntb->dev, "Command services unsupported\n");
688 
689 	return -EINVAL;
690 }
691 
692 static int perf_enable_service(struct perf_ctx *perf)
693 {
694 	u64 mask, incmd_bit;
695 	int ret, sidx, scnt;
696 
697 	mask = ntb_db_valid_mask(perf->ntb);
698 	(void)ntb_db_set_mask(perf->ntb, mask);
699 
700 	ret = ntb_set_ctx(perf->ntb, perf, &perf_ops);
701 	if (ret)
702 		return ret;
703 
704 	if (perf->cmd_send == perf_msg_cmd_send) {
705 		u64 inbits, outbits;
706 
707 		inbits = ntb_msg_inbits(perf->ntb);
708 		outbits = ntb_msg_outbits(perf->ntb);
709 		(void)ntb_msg_set_mask(perf->ntb, inbits | outbits);
710 
711 		incmd_bit = BIT_ULL(__ffs64(inbits));
712 		ret = ntb_msg_clear_mask(perf->ntb, incmd_bit);
713 
714 		dev_dbg(&perf->ntb->dev, "MSG sts unmasked %#llx\n", incmd_bit);
715 	} else {
716 		scnt = ntb_spad_count(perf->ntb);
717 		for (sidx = 0; sidx < scnt; sidx++)
718 			ntb_spad_write(perf->ntb, sidx, PERF_CMD_INVAL);
719 		incmd_bit = PERF_SPAD_NOTIFY(perf->gidx);
720 		ret = ntb_db_clear_mask(perf->ntb, incmd_bit);
721 
722 		dev_dbg(&perf->ntb->dev, "DB bits unmasked %#llx\n", incmd_bit);
723 	}
724 	if (ret) {
725 		ntb_clear_ctx(perf->ntb);
726 		return ret;
727 	}
728 
729 	ntb_link_enable(perf->ntb, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
730 	/* Might be not necessary */
731 	ntb_link_event(perf->ntb);
732 
733 	return 0;
734 }
735 
736 static void perf_disable_service(struct perf_ctx *perf)
737 {
738 	int pidx;
739 
740 	ntb_link_disable(perf->ntb);
741 
742 	if (perf->cmd_send == perf_msg_cmd_send) {
743 		u64 inbits;
744 
745 		inbits = ntb_msg_inbits(perf->ntb);
746 		(void)ntb_msg_set_mask(perf->ntb, inbits);
747 	} else {
748 		(void)ntb_db_set_mask(perf->ntb, PERF_SPAD_NOTIFY(perf->gidx));
749 	}
750 
751 	ntb_clear_ctx(perf->ntb);
752 
753 	for (pidx = 0; pidx < perf->pcnt; pidx++)
754 		perf_cmd_exec(&perf->peers[pidx], PERF_CMD_CLEAR);
755 
756 	for (pidx = 0; pidx < perf->pcnt; pidx++)
757 		flush_work(&perf->peers[pidx].service);
758 }
759 
760 /*==============================================================================
761  *                      Performance measuring work-thread
762  *==============================================================================
763  */
764 
765 static void perf_dma_copy_callback(void *data)
766 {
767 	struct perf_thread *pthr = data;
768 
769 	atomic_dec(&pthr->dma_sync);
770 	wake_up(&pthr->dma_wait);
771 }
772 
773 static int perf_copy_chunk(struct perf_thread *pthr,
774 			   void __iomem *dst, void *src, size_t len)
775 {
776 	struct dma_async_tx_descriptor *tx;
777 	struct dmaengine_unmap_data *unmap;
778 	struct device *dma_dev;
779 	int try = 0, ret = 0;
780 
781 	if (!use_dma) {
782 		memcpy_toio(dst, src, len);
783 		goto ret_check_tsync;
784 	}
785 
786 	dma_dev = pthr->dma_chan->device->dev;
787 
788 	if (!is_dma_copy_aligned(pthr->dma_chan->device, offset_in_page(src),
789 				 offset_in_page(dst), len))
790 		return -EIO;
791 
792 	unmap = dmaengine_get_unmap_data(dma_dev, 2, GFP_NOWAIT);
793 	if (!unmap)
794 		return -ENOMEM;
795 
796 	unmap->len = len;
797 	unmap->addr[0] = dma_map_page(dma_dev, virt_to_page(src),
798 		offset_in_page(src), len, DMA_TO_DEVICE);
799 	if (dma_mapping_error(dma_dev, unmap->addr[0])) {
800 		ret = -EIO;
801 		goto err_free_resource;
802 	}
803 	unmap->to_cnt = 1;
804 
805 	unmap->addr[1] = dma_map_page(dma_dev, virt_to_page(dst),
806 		offset_in_page(dst), len, DMA_FROM_DEVICE);
807 	if (dma_mapping_error(dma_dev, unmap->addr[1])) {
808 		ret = -EIO;
809 		goto err_free_resource;
810 	}
811 	unmap->from_cnt = 1;
812 
813 	do {
814 		tx = dmaengine_prep_dma_memcpy(pthr->dma_chan, unmap->addr[1],
815 			unmap->addr[0], len, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
816 		if (!tx)
817 			msleep(DMA_MDELAY);
818 	} while (!tx && (try++ < DMA_TRIES));
819 
820 	if (!tx) {
821 		ret = -EIO;
822 		goto err_free_resource;
823 	}
824 
825 	tx->callback = perf_dma_copy_callback;
826 	tx->callback_param = pthr;
827 	dma_set_unmap(tx, unmap);
828 
829 	ret = dma_submit_error(dmaengine_submit(tx));
830 	if (ret) {
831 		dmaengine_unmap_put(unmap);
832 		goto err_free_resource;
833 	}
834 
835 	dmaengine_unmap_put(unmap);
836 
837 	atomic_inc(&pthr->dma_sync);
838 	dma_async_issue_pending(pthr->dma_chan);
839 
840 ret_check_tsync:
841 	return likely(atomic_read(&pthr->perf->tsync) > 0) ? 0 : -EINTR;
842 
843 err_free_resource:
844 	dmaengine_unmap_put(unmap);
845 
846 	return ret;
847 }
848 
849 static bool perf_dma_filter(struct dma_chan *chan, void *data)
850 {
851 	struct perf_ctx *perf = data;
852 	int node;
853 
854 	node = dev_to_node(&perf->ntb->dev);
855 
856 	return node == NUMA_NO_NODE || node == dev_to_node(chan->device->dev);
857 }
858 
859 static int perf_init_test(struct perf_thread *pthr)
860 {
861 	struct perf_ctx *perf = pthr->perf;
862 	dma_cap_mask_t dma_mask;
863 
864 	pthr->src = kmalloc_node(perf->test_peer->outbuf_size, GFP_KERNEL,
865 				 dev_to_node(&perf->ntb->dev));
866 	if (!pthr->src)
867 		return -ENOMEM;
868 
869 	get_random_bytes(pthr->src, perf->test_peer->outbuf_size);
870 
871 	if (!use_dma)
872 		return 0;
873 
874 	dma_cap_zero(dma_mask);
875 	dma_cap_set(DMA_MEMCPY, dma_mask);
876 	pthr->dma_chan = dma_request_channel(dma_mask, perf_dma_filter, perf);
877 	if (!pthr->dma_chan) {
878 		dev_err(&perf->ntb->dev, "%d: Failed to get DMA channel\n",
879 			pthr->tidx);
880 		atomic_dec(&perf->tsync);
881 		wake_up(&perf->twait);
882 		kfree(pthr->src);
883 		return -ENODEV;
884 	}
885 
886 	atomic_set(&pthr->dma_sync, 0);
887 
888 	return 0;
889 }
890 
891 static int perf_run_test(struct perf_thread *pthr)
892 {
893 	struct perf_peer *peer = pthr->perf->test_peer;
894 	struct perf_ctx *perf = pthr->perf;
895 	void __iomem *flt_dst, *bnd_dst;
896 	u64 total_size, chunk_size;
897 	void *flt_src;
898 	int ret = 0;
899 
900 	total_size = 1ULL << total_order;
901 	chunk_size = 1ULL << chunk_order;
902 	chunk_size = min_t(u64, peer->outbuf_size, chunk_size);
903 
904 	flt_src = pthr->src;
905 	bnd_dst = peer->outbuf + peer->outbuf_size;
906 	flt_dst = peer->outbuf;
907 
908 	pthr->duration = ktime_get();
909 
910 	/* Copied field is cleared on test launch stage */
911 	while (pthr->copied < total_size) {
912 		ret = perf_copy_chunk(pthr, flt_dst, flt_src, chunk_size);
913 		if (ret) {
914 			dev_err(&perf->ntb->dev, "%d: Got error %d on test\n",
915 				pthr->tidx, ret);
916 			return ret;
917 		}
918 
919 		pthr->copied += chunk_size;
920 
921 		flt_dst += chunk_size;
922 		flt_src += chunk_size;
923 		if (flt_dst >= bnd_dst || flt_dst < peer->outbuf) {
924 			flt_dst = peer->outbuf;
925 			flt_src = pthr->src;
926 		}
927 
928 		/* Give up CPU to give a chance for other threads to use it */
929 		schedule();
930 	}
931 
932 	return 0;
933 }
934 
935 static int perf_sync_test(struct perf_thread *pthr)
936 {
937 	struct perf_ctx *perf = pthr->perf;
938 
939 	if (!use_dma)
940 		goto no_dma_ret;
941 
942 	wait_event(pthr->dma_wait,
943 		   (atomic_read(&pthr->dma_sync) == 0 ||
944 		    atomic_read(&perf->tsync) < 0));
945 
946 	if (atomic_read(&perf->tsync) < 0)
947 		return -EINTR;
948 
949 no_dma_ret:
950 	pthr->duration = ktime_sub(ktime_get(), pthr->duration);
951 
952 	dev_dbg(&perf->ntb->dev, "%d: copied %llu bytes\n",
953 		pthr->tidx, pthr->copied);
954 
955 	dev_dbg(&perf->ntb->dev, "%d: lasted %llu usecs\n",
956 		pthr->tidx, ktime_to_us(pthr->duration));
957 
958 	dev_dbg(&perf->ntb->dev, "%d: %llu MBytes/s\n", pthr->tidx,
959 		div64_u64(pthr->copied, ktime_to_us(pthr->duration)));
960 
961 	return 0;
962 }
963 
964 static void perf_clear_test(struct perf_thread *pthr)
965 {
966 	struct perf_ctx *perf = pthr->perf;
967 
968 	if (!use_dma)
969 		goto no_dma_notify;
970 
971 	/*
972 	 * If test finished without errors, termination isn't needed.
973 	 * We call it anyway just to be sure of the transfers completion.
974 	 */
975 	(void)dmaengine_terminate_sync(pthr->dma_chan);
976 
977 	dma_release_channel(pthr->dma_chan);
978 
979 no_dma_notify:
980 	atomic_dec(&perf->tsync);
981 	wake_up(&perf->twait);
982 	kfree(pthr->src);
983 }
984 
985 static void perf_thread_work(struct work_struct *work)
986 {
987 	struct perf_thread *pthr = to_thread_work(work);
988 	int ret;
989 
990 	/*
991 	 * Perform stages in compliance with use_dma flag value.
992 	 * Test status is changed only if error happened, otherwise
993 	 * status -ENODATA is kept while test is on-fly. Results
994 	 * synchronization is performed only if test fininshed
995 	 * without an error or interruption.
996 	 */
997 	ret = perf_init_test(pthr);
998 	if (ret) {
999 		pthr->status = ret;
1000 		return;
1001 	}
1002 
1003 	ret = perf_run_test(pthr);
1004 	if (ret) {
1005 		pthr->status = ret;
1006 		goto err_clear_test;
1007 	}
1008 
1009 	pthr->status = perf_sync_test(pthr);
1010 
1011 err_clear_test:
1012 	perf_clear_test(pthr);
1013 }
1014 
1015 static int perf_set_tcnt(struct perf_ctx *perf, u8 tcnt)
1016 {
1017 	if (tcnt == 0 || tcnt > MAX_THREADS_CNT)
1018 		return -EINVAL;
1019 
1020 	if (test_and_set_bit_lock(0, &perf->busy_flag))
1021 		return -EBUSY;
1022 
1023 	perf->tcnt = tcnt;
1024 
1025 	clear_bit_unlock(0, &perf->busy_flag);
1026 
1027 	return 0;
1028 }
1029 
1030 static void perf_terminate_test(struct perf_ctx *perf)
1031 {
1032 	int tidx;
1033 
1034 	atomic_set(&perf->tsync, -1);
1035 	wake_up(&perf->twait);
1036 
1037 	for (tidx = 0; tidx < MAX_THREADS_CNT; tidx++) {
1038 		wake_up(&perf->threads[tidx].dma_wait);
1039 		cancel_work_sync(&perf->threads[tidx].work);
1040 	}
1041 }
1042 
1043 static int perf_submit_test(struct perf_peer *peer)
1044 {
1045 	struct perf_ctx *perf = peer->perf;
1046 	struct perf_thread *pthr;
1047 	int tidx, ret;
1048 
1049 	if (!test_bit(PERF_STS_DONE, &peer->sts))
1050 		return -ENOLINK;
1051 
1052 	if (test_and_set_bit_lock(0, &perf->busy_flag))
1053 		return -EBUSY;
1054 
1055 	perf->test_peer = peer;
1056 	atomic_set(&perf->tsync, perf->tcnt);
1057 
1058 	for (tidx = 0; tidx < MAX_THREADS_CNT; tidx++) {
1059 		pthr = &perf->threads[tidx];
1060 
1061 		pthr->status = -ENODATA;
1062 		pthr->copied = 0;
1063 		pthr->duration = ktime_set(0, 0);
1064 		if (tidx < perf->tcnt)
1065 			(void)queue_work(perf_wq, &pthr->work);
1066 	}
1067 
1068 	ret = wait_event_interruptible(perf->twait,
1069 				       atomic_read(&perf->tsync) <= 0);
1070 	if (ret == -ERESTARTSYS) {
1071 		perf_terminate_test(perf);
1072 		ret = -EINTR;
1073 	}
1074 
1075 	clear_bit_unlock(0, &perf->busy_flag);
1076 
1077 	return ret;
1078 }
1079 
1080 static int perf_read_stats(struct perf_ctx *perf, char *buf,
1081 			   size_t size, ssize_t *pos)
1082 {
1083 	struct perf_thread *pthr;
1084 	int tidx;
1085 
1086 	if (test_and_set_bit_lock(0, &perf->busy_flag))
1087 		return -EBUSY;
1088 
1089 	(*pos) += scnprintf(buf + *pos, size - *pos,
1090 		"    Peer %d test statistics:\n", perf->test_peer->pidx);
1091 
1092 	for (tidx = 0; tidx < MAX_THREADS_CNT; tidx++) {
1093 		pthr = &perf->threads[tidx];
1094 
1095 		if (pthr->status == -ENODATA)
1096 			continue;
1097 
1098 		if (pthr->status) {
1099 			(*pos) += scnprintf(buf + *pos, size - *pos,
1100 				"%d: error status %d\n", tidx, pthr->status);
1101 			continue;
1102 		}
1103 
1104 		(*pos) += scnprintf(buf + *pos, size - *pos,
1105 			"%d: copied %llu bytes in %llu usecs, %llu MBytes/s\n",
1106 			tidx, pthr->copied, ktime_to_us(pthr->duration),
1107 			div64_u64(pthr->copied, ktime_to_us(pthr->duration)));
1108 	}
1109 
1110 	clear_bit_unlock(0, &perf->busy_flag);
1111 
1112 	return 0;
1113 }
1114 
1115 static void perf_init_threads(struct perf_ctx *perf)
1116 {
1117 	struct perf_thread *pthr;
1118 	int tidx;
1119 
1120 	perf->tcnt = DEF_THREADS_CNT;
1121 	perf->test_peer = &perf->peers[0];
1122 	init_waitqueue_head(&perf->twait);
1123 
1124 	for (tidx = 0; tidx < MAX_THREADS_CNT; tidx++) {
1125 		pthr = &perf->threads[tidx];
1126 
1127 		pthr->perf = perf;
1128 		pthr->tidx = tidx;
1129 		pthr->status = -ENODATA;
1130 		init_waitqueue_head(&pthr->dma_wait);
1131 		INIT_WORK(&pthr->work, perf_thread_work);
1132 	}
1133 }
1134 
1135 static void perf_clear_threads(struct perf_ctx *perf)
1136 {
1137 	perf_terminate_test(perf);
1138 }
1139 
1140 /*==============================================================================
1141  *                               DebugFS nodes
1142  *==============================================================================
1143  */
1144 
1145 static ssize_t perf_dbgfs_read_info(struct file *filep, char __user *ubuf,
1146 				    size_t size, loff_t *offp)
1147 {
1148 	struct perf_ctx *perf = filep->private_data;
1149 	struct perf_peer *peer;
1150 	size_t buf_size;
1151 	ssize_t pos = 0;
1152 	int ret, pidx;
1153 	char *buf;
1154 
1155 	buf_size = min_t(size_t, size, 0x1000U);
1156 
1157 	buf = kmalloc(buf_size, GFP_KERNEL);
1158 	if (!buf)
1159 		return -ENOMEM;
1160 
1161 	pos += scnprintf(buf + pos, buf_size - pos,
1162 		"    Performance measuring tool info:\n\n");
1163 
1164 	pos += scnprintf(buf + pos, buf_size - pos,
1165 		"Local port %d, Global index %d\n", ntb_port_number(perf->ntb),
1166 		perf->gidx);
1167 	pos += scnprintf(buf + pos, buf_size - pos, "Test status: ");
1168 	if (test_bit(0, &perf->busy_flag)) {
1169 		pos += scnprintf(buf + pos, buf_size - pos,
1170 			"on-fly with port %d (%d)\n",
1171 			ntb_peer_port_number(perf->ntb, perf->test_peer->pidx),
1172 			perf->test_peer->pidx);
1173 	} else {
1174 		pos += scnprintf(buf + pos, buf_size - pos, "idle\n");
1175 	}
1176 
1177 	for (pidx = 0; pidx < perf->pcnt; pidx++) {
1178 		peer = &perf->peers[pidx];
1179 
1180 		pos += scnprintf(buf + pos, buf_size - pos,
1181 			"Port %d (%d), Global index %d:\n",
1182 			ntb_peer_port_number(perf->ntb, peer->pidx), peer->pidx,
1183 			peer->gidx);
1184 
1185 		pos += scnprintf(buf + pos, buf_size - pos,
1186 			"\tLink status: %s\n",
1187 			test_bit(PERF_STS_LNKUP, &peer->sts) ? "up" : "down");
1188 
1189 		pos += scnprintf(buf + pos, buf_size - pos,
1190 			"\tOut buffer addr 0x%pK\n", peer->outbuf);
1191 
1192 		pos += scnprintf(buf + pos, buf_size - pos,
1193 			"\tOut buffer size %pa\n", &peer->outbuf_size);
1194 
1195 		pos += scnprintf(buf + pos, buf_size - pos,
1196 			"\tOut buffer xlat 0x%016llx[p]\n", peer->outbuf_xlat);
1197 
1198 		if (!peer->inbuf) {
1199 			pos += scnprintf(buf + pos, buf_size - pos,
1200 				"\tIn buffer addr: unallocated\n");
1201 			continue;
1202 		}
1203 
1204 		pos += scnprintf(buf + pos, buf_size - pos,
1205 			"\tIn buffer addr 0x%pK\n", peer->inbuf);
1206 
1207 		pos += scnprintf(buf + pos, buf_size - pos,
1208 			"\tIn buffer size %pa\n", &peer->inbuf_size);
1209 
1210 		pos += scnprintf(buf + pos, buf_size - pos,
1211 			"\tIn buffer xlat %pad[p]\n", &peer->inbuf_xlat);
1212 	}
1213 
1214 	ret = simple_read_from_buffer(ubuf, size, offp, buf, pos);
1215 	kfree(buf);
1216 
1217 	return ret;
1218 }
1219 
1220 static const struct file_operations perf_dbgfs_info = {
1221 	.open = simple_open,
1222 	.read = perf_dbgfs_read_info
1223 };
1224 
1225 static ssize_t perf_dbgfs_read_run(struct file *filep, char __user *ubuf,
1226 				   size_t size, loff_t *offp)
1227 {
1228 	struct perf_ctx *perf = filep->private_data;
1229 	ssize_t ret, pos = 0;
1230 	char *buf;
1231 
1232 	buf = kmalloc(PERF_BUF_LEN, GFP_KERNEL);
1233 	if (!buf)
1234 		return -ENOMEM;
1235 
1236 	ret = perf_read_stats(perf, buf, PERF_BUF_LEN, &pos);
1237 	if (ret)
1238 		goto err_free;
1239 
1240 	ret = simple_read_from_buffer(ubuf, size, offp, buf, pos);
1241 err_free:
1242 	kfree(buf);
1243 
1244 	return ret;
1245 }
1246 
1247 static ssize_t perf_dbgfs_write_run(struct file *filep, const char __user *ubuf,
1248 				    size_t size, loff_t *offp)
1249 {
1250 	struct perf_ctx *perf = filep->private_data;
1251 	struct perf_peer *peer;
1252 	int pidx, ret;
1253 
1254 	ret = kstrtoint_from_user(ubuf, size, 0, &pidx);
1255 	if (ret)
1256 		return ret;
1257 
1258 	if (pidx < 0 || pidx >= perf->pcnt)
1259 		return -EINVAL;
1260 
1261 	peer = &perf->peers[pidx];
1262 
1263 	ret = perf_submit_test(peer);
1264 	if (ret)
1265 		return ret;
1266 
1267 	return size;
1268 }
1269 
1270 static const struct file_operations perf_dbgfs_run = {
1271 	.open = simple_open,
1272 	.read = perf_dbgfs_read_run,
1273 	.write = perf_dbgfs_write_run
1274 };
1275 
1276 static ssize_t perf_dbgfs_read_tcnt(struct file *filep, char __user *ubuf,
1277 				    size_t size, loff_t *offp)
1278 {
1279 	struct perf_ctx *perf = filep->private_data;
1280 	char buf[8];
1281 	ssize_t pos;
1282 
1283 	pos = scnprintf(buf, sizeof(buf), "%hhu\n", perf->tcnt);
1284 
1285 	return simple_read_from_buffer(ubuf, size, offp, buf, pos);
1286 }
1287 
1288 static ssize_t perf_dbgfs_write_tcnt(struct file *filep,
1289 				     const char __user *ubuf,
1290 				     size_t size, loff_t *offp)
1291 {
1292 	struct perf_ctx *perf = filep->private_data;
1293 	int ret;
1294 	u8 val;
1295 
1296 	ret = kstrtou8_from_user(ubuf, size, 0, &val);
1297 	if (ret)
1298 		return ret;
1299 
1300 	ret = perf_set_tcnt(perf, val);
1301 	if (ret)
1302 		return ret;
1303 
1304 	return size;
1305 }
1306 
1307 static const struct file_operations perf_dbgfs_tcnt = {
1308 	.open = simple_open,
1309 	.read = perf_dbgfs_read_tcnt,
1310 	.write = perf_dbgfs_write_tcnt
1311 };
1312 
1313 static void perf_setup_dbgfs(struct perf_ctx *perf)
1314 {
1315 	struct pci_dev *pdev = perf->ntb->pdev;
1316 
1317 	perf->dbgfs_dir = debugfs_create_dir(pci_name(pdev), perf_dbgfs_topdir);
1318 	if (!perf->dbgfs_dir) {
1319 		dev_warn(&perf->ntb->dev, "DebugFS unsupported\n");
1320 		return;
1321 	}
1322 
1323 	debugfs_create_file("info", 0600, perf->dbgfs_dir, perf,
1324 			    &perf_dbgfs_info);
1325 
1326 	debugfs_create_file("run", 0600, perf->dbgfs_dir, perf,
1327 			    &perf_dbgfs_run);
1328 
1329 	debugfs_create_file("threads_count", 0600, perf->dbgfs_dir, perf,
1330 			    &perf_dbgfs_tcnt);
1331 
1332 	/* They are made read-only for test exec safety and integrity */
1333 	debugfs_create_u8("chunk_order", 0500, perf->dbgfs_dir, &chunk_order);
1334 
1335 	debugfs_create_u8("total_order", 0500, perf->dbgfs_dir, &total_order);
1336 
1337 	debugfs_create_bool("use_dma", 0500, perf->dbgfs_dir, &use_dma);
1338 }
1339 
1340 static void perf_clear_dbgfs(struct perf_ctx *perf)
1341 {
1342 	debugfs_remove_recursive(perf->dbgfs_dir);
1343 }
1344 
1345 /*==============================================================================
1346  *                        Basic driver initialization
1347  *==============================================================================
1348  */
1349 
1350 static struct perf_ctx *perf_create_data(struct ntb_dev *ntb)
1351 {
1352 	struct perf_ctx *perf;
1353 
1354 	perf = devm_kzalloc(&ntb->dev, sizeof(*perf), GFP_KERNEL);
1355 	if (!perf)
1356 		return ERR_PTR(-ENOMEM);
1357 
1358 	perf->pcnt = ntb_peer_port_count(ntb);
1359 	perf->peers = devm_kcalloc(&ntb->dev, perf->pcnt, sizeof(*perf->peers),
1360 				  GFP_KERNEL);
1361 	if (!perf->peers)
1362 		return ERR_PTR(-ENOMEM);
1363 
1364 	perf->ntb = ntb;
1365 
1366 	return perf;
1367 }
1368 
1369 static int perf_setup_peer_mw(struct perf_peer *peer)
1370 {
1371 	struct perf_ctx *perf = peer->perf;
1372 	phys_addr_t phys_addr;
1373 	int ret;
1374 
1375 	/* Get outbound MW parameters and map it */
1376 	ret = ntb_peer_mw_get_addr(perf->ntb, peer->gidx, &phys_addr,
1377 				   &peer->outbuf_size);
1378 	if (ret)
1379 		return ret;
1380 
1381 	peer->outbuf = devm_ioremap_wc(&perf->ntb->dev, phys_addr,
1382 					peer->outbuf_size);
1383 	if (!peer->outbuf)
1384 		return -ENOMEM;
1385 
1386 	if (max_mw_size && peer->outbuf_size > max_mw_size) {
1387 		peer->outbuf_size = max_mw_size;
1388 		dev_warn(&peer->perf->ntb->dev,
1389 			"Peer %d outbuf reduced to %pa\n", peer->pidx,
1390 			&peer->outbuf_size);
1391 	}
1392 
1393 	return 0;
1394 }
1395 
1396 static int perf_init_peers(struct perf_ctx *perf)
1397 {
1398 	struct perf_peer *peer;
1399 	int pidx, lport, ret;
1400 
1401 	lport = ntb_port_number(perf->ntb);
1402 	perf->gidx = -1;
1403 	for (pidx = 0; pidx < perf->pcnt; pidx++) {
1404 		peer = &perf->peers[pidx];
1405 
1406 		peer->perf = perf;
1407 		peer->pidx = pidx;
1408 		if (lport < ntb_peer_port_number(perf->ntb, pidx)) {
1409 			if (perf->gidx == -1)
1410 				perf->gidx = pidx;
1411 			peer->gidx = pidx + 1;
1412 		} else {
1413 			peer->gidx = pidx;
1414 		}
1415 		INIT_WORK(&peer->service, perf_service_work);
1416 	}
1417 	if (perf->gidx == -1)
1418 		perf->gidx = pidx;
1419 
1420 	for (pidx = 0; pidx < perf->pcnt; pidx++) {
1421 		ret = perf_setup_peer_mw(&perf->peers[pidx]);
1422 		if (ret)
1423 			return ret;
1424 	}
1425 
1426 	dev_dbg(&perf->ntb->dev, "Global port index %d\n", perf->gidx);
1427 
1428 	return 0;
1429 }
1430 
1431 static int perf_probe(struct ntb_client *client, struct ntb_dev *ntb)
1432 {
1433 	struct perf_ctx *perf;
1434 	int ret;
1435 
1436 	perf = perf_create_data(ntb);
1437 	if (IS_ERR(perf))
1438 		return PTR_ERR(perf);
1439 
1440 	ret = perf_init_peers(perf);
1441 	if (ret)
1442 		return ret;
1443 
1444 	perf_init_threads(perf);
1445 
1446 	ret = perf_init_service(perf);
1447 	if (ret)
1448 		return ret;
1449 
1450 	ret = perf_enable_service(perf);
1451 	if (ret)
1452 		return ret;
1453 
1454 	perf_setup_dbgfs(perf);
1455 
1456 	return 0;
1457 }
1458 
1459 static void perf_remove(struct ntb_client *client, struct ntb_dev *ntb)
1460 {
1461 	struct perf_ctx *perf = ntb->ctx;
1462 
1463 	perf_clear_dbgfs(perf);
1464 
1465 	perf_disable_service(perf);
1466 
1467 	perf_clear_threads(perf);
1468 }
1469 
1470 static struct ntb_client perf_client = {
1471 	.ops = {
1472 		.probe = perf_probe,
1473 		.remove = perf_remove
1474 	}
1475 };
1476 
1477 static int __init perf_init(void)
1478 {
1479 	int ret;
1480 
1481 	if (chunk_order > MAX_CHUNK_ORDER) {
1482 		chunk_order = MAX_CHUNK_ORDER;
1483 		pr_info("Chunk order reduced to %hhu\n", chunk_order);
1484 	}
1485 
1486 	if (total_order < chunk_order) {
1487 		total_order = chunk_order;
1488 		pr_info("Total data order reduced to %hhu\n", total_order);
1489 	}
1490 
1491 	perf_wq = alloc_workqueue("perf_wq", WQ_UNBOUND | WQ_SYSFS, 0);
1492 	if (!perf_wq)
1493 		return -ENOMEM;
1494 
1495 	if (debugfs_initialized())
1496 		perf_dbgfs_topdir = debugfs_create_dir(KBUILD_MODNAME, NULL);
1497 
1498 	ret = ntb_register_client(&perf_client);
1499 	if (ret) {
1500 		debugfs_remove_recursive(perf_dbgfs_topdir);
1501 		destroy_workqueue(perf_wq);
1502 	}
1503 
1504 	return ret;
1505 }
1506 module_init(perf_init);
1507 
1508 static void __exit perf_exit(void)
1509 {
1510 	ntb_unregister_client(&perf_client);
1511 	debugfs_remove_recursive(perf_dbgfs_topdir);
1512 	destroy_workqueue(perf_wq);
1513 }
1514 module_exit(perf_exit);
1515 
1516