xref: /openbmc/linux/drivers/scsi/fnic/fnic_debugfs.c (revision 160b8e75)
1 /*
2  * Copyright 2012 Cisco Systems, Inc.  All rights reserved.
3  *
4  * This program is free software; you may redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; version 2 of the License.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
9  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
10  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
11  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
12  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
13  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
14  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
15  * SOFTWARE.
16  */
17 
18 #include <linux/module.h>
19 #include <linux/errno.h>
20 #include <linux/debugfs.h>
21 #include <linux/vmalloc.h>
22 #include "fnic.h"
23 
24 static struct dentry *fnic_trace_debugfs_root;
25 static struct dentry *fnic_trace_debugfs_file;
26 static struct dentry *fnic_trace_enable;
27 static struct dentry *fnic_stats_debugfs_root;
28 
29 static struct dentry *fnic_fc_trace_debugfs_file;
30 static struct dentry *fnic_fc_rdata_trace_debugfs_file;
31 static struct dentry *fnic_fc_trace_enable;
32 static struct dentry *fnic_fc_trace_clear;
33 
34 struct fc_trace_flag_type {
35 	u8 fc_row_file;
36 	u8 fc_normal_file;
37 	u8 fnic_trace;
38 	u8 fc_trace;
39 	u8 fc_clear;
40 };
41 
42 static struct fc_trace_flag_type *fc_trc_flag;
43 
44 /*
45  * fnic_debugfs_init - Initialize debugfs for fnic debug logging
46  *
47  * Description:
48  * When Debugfs is configured this routine sets up the fnic debugfs
49  * file system. If not already created, this routine will create the
50  * fnic directory and statistics directory for trace buffer and
51  * stats logging.
52  */
53 int fnic_debugfs_init(void)
54 {
55 	int rc = -1;
56 	fnic_trace_debugfs_root = debugfs_create_dir("fnic", NULL);
57 	if (!fnic_trace_debugfs_root) {
58 		printk(KERN_DEBUG "Cannot create debugfs root\n");
59 		return rc;
60 	}
61 
62 	if (!fnic_trace_debugfs_root) {
63 		printk(KERN_DEBUG
64 			"fnic root directory doesn't exist in debugfs\n");
65 		return rc;
66 	}
67 
68 	fnic_stats_debugfs_root = debugfs_create_dir("statistics",
69 						fnic_trace_debugfs_root);
70 	if (!fnic_stats_debugfs_root) {
71 		printk(KERN_DEBUG "Cannot create Statistics directory\n");
72 		return rc;
73 	}
74 
75 	/* Allocate memory to structure */
76 	fc_trc_flag = (struct fc_trace_flag_type *)
77 		vmalloc(sizeof(struct fc_trace_flag_type));
78 
79 	if (fc_trc_flag) {
80 		fc_trc_flag->fc_row_file = 0;
81 		fc_trc_flag->fc_normal_file = 1;
82 		fc_trc_flag->fnic_trace = 2;
83 		fc_trc_flag->fc_trace = 3;
84 		fc_trc_flag->fc_clear = 4;
85 	}
86 
87 	rc = 0;
88 	return rc;
89 }
90 
91 /*
92  * fnic_debugfs_terminate - Tear down debugfs infrastructure
93  *
94  * Description:
95  * When Debugfs is configured this routine removes debugfs file system
96  * elements that are specific to fnic.
97  */
98 void fnic_debugfs_terminate(void)
99 {
100 	debugfs_remove(fnic_stats_debugfs_root);
101 	fnic_stats_debugfs_root = NULL;
102 
103 	debugfs_remove(fnic_trace_debugfs_root);
104 	fnic_trace_debugfs_root = NULL;
105 
106 	if (fc_trc_flag)
107 		vfree(fc_trc_flag);
108 }
109 
110 /*
111  * fnic_trace_ctrl_read -
112  *          Read  trace_enable ,fc_trace_enable
113  *              or fc_trace_clear debugfs file
114  * @filp: The file pointer to read from.
115  * @ubuf: The buffer to copy the data to.
116  * @cnt: The number of bytes to read.
117  * @ppos: The position in the file to start reading from.
118  *
119  * Description:
120  * This routine reads value of variable fnic_tracing_enabled or
121  * fnic_fc_tracing_enabled or fnic_fc_trace_cleared
122  * and stores into local @buf.
123  * It will start reading file at @ppos and
124  * copy up to @cnt of data to @ubuf from @buf.
125  *
126  * Returns:
127  * This function returns the amount of data that was read.
128  */
129 static ssize_t fnic_trace_ctrl_read(struct file *filp,
130 				  char __user *ubuf,
131 				  size_t cnt, loff_t *ppos)
132 {
133 	char buf[64];
134 	int len;
135 	u8 *trace_type;
136 	len = 0;
137 	trace_type = (u8 *)filp->private_data;
138 	if (*trace_type == fc_trc_flag->fnic_trace)
139 		len = sprintf(buf, "%u\n", fnic_tracing_enabled);
140 	else if (*trace_type == fc_trc_flag->fc_trace)
141 		len = sprintf(buf, "%u\n", fnic_fc_tracing_enabled);
142 	else if (*trace_type == fc_trc_flag->fc_clear)
143 		len = sprintf(buf, "%u\n", fnic_fc_trace_cleared);
144 	else
145 		pr_err("fnic: Cannot read to any debugfs file\n");
146 
147 	return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
148 }
149 
150 /*
151  * fnic_trace_ctrl_write -
152  * Write to trace_enable, fc_trace_enable or
153  *         fc_trace_clear debugfs file
154  * @filp: The file pointer to write from.
155  * @ubuf: The buffer to copy the data from.
156  * @cnt: The number of bytes to write.
157  * @ppos: The position in the file to start writing to.
158  *
159  * Description:
160  * This routine writes data from user buffer @ubuf to buffer @buf and
161  * sets fc_trace_enable ,tracing_enable or fnic_fc_trace_cleared
162  * value as per user input.
163  *
164  * Returns:
165  * This function returns the amount of data that was written.
166  */
167 static ssize_t fnic_trace_ctrl_write(struct file *filp,
168 				  const char __user *ubuf,
169 				  size_t cnt, loff_t *ppos)
170 {
171 	char buf[64];
172 	unsigned long val;
173 	int ret;
174 	u8 *trace_type;
175 	trace_type = (u8 *)filp->private_data;
176 
177 	if (cnt >= sizeof(buf))
178 		return -EINVAL;
179 
180 	if (copy_from_user(&buf, ubuf, cnt))
181 		return -EFAULT;
182 
183 	buf[cnt] = 0;
184 
185 	ret = kstrtoul(buf, 10, &val);
186 	if (ret < 0)
187 		return ret;
188 
189 	if (*trace_type == fc_trc_flag->fnic_trace)
190 		fnic_tracing_enabled = val;
191 	else if (*trace_type == fc_trc_flag->fc_trace)
192 		fnic_fc_tracing_enabled = val;
193 	else if (*trace_type == fc_trc_flag->fc_clear)
194 		fnic_fc_trace_cleared = val;
195 	else
196 		pr_err("fnic: cannot write to any debugfs file\n");
197 
198 	(*ppos)++;
199 
200 	return cnt;
201 }
202 
203 static const struct file_operations fnic_trace_ctrl_fops = {
204 	.owner = THIS_MODULE,
205 	.open = simple_open,
206 	.read = fnic_trace_ctrl_read,
207 	.write = fnic_trace_ctrl_write,
208 };
209 
210 /*
211  * fnic_trace_debugfs_open - Open the fnic trace log
212  * @inode: The inode pointer
213  * @file: The file pointer to attach the log output
214  *
215  * Description:
216  * This routine is the entry point for the debugfs open file operation.
217  * It allocates the necessary buffer for the log, fills the buffer from
218  * the in-memory log and then returns a pointer to that log in
219  * the private_data field in @file.
220  *
221  * Returns:
222  * This function returns zero if successful. On error it will return
223  * a negative error value.
224  */
225 static int fnic_trace_debugfs_open(struct inode *inode,
226 				  struct file *file)
227 {
228 	fnic_dbgfs_t *fnic_dbg_prt;
229 	u8 *rdata_ptr;
230 	rdata_ptr = (u8 *)inode->i_private;
231 	fnic_dbg_prt = kzalloc(sizeof(fnic_dbgfs_t), GFP_KERNEL);
232 	if (!fnic_dbg_prt)
233 		return -ENOMEM;
234 
235 	if (*rdata_ptr == fc_trc_flag->fnic_trace) {
236 		fnic_dbg_prt->buffer = vmalloc(3 *
237 					(trace_max_pages * PAGE_SIZE));
238 		if (!fnic_dbg_prt->buffer) {
239 			kfree(fnic_dbg_prt);
240 			return -ENOMEM;
241 		}
242 		memset((void *)fnic_dbg_prt->buffer, 0,
243 		3 * (trace_max_pages * PAGE_SIZE));
244 		fnic_dbg_prt->buffer_len = fnic_get_trace_data(fnic_dbg_prt);
245 	} else {
246 		fnic_dbg_prt->buffer =
247 			vmalloc(3 * (fnic_fc_trace_max_pages * PAGE_SIZE));
248 		if (!fnic_dbg_prt->buffer) {
249 			kfree(fnic_dbg_prt);
250 			return -ENOMEM;
251 		}
252 		memset((void *)fnic_dbg_prt->buffer, 0,
253 			3 * (fnic_fc_trace_max_pages * PAGE_SIZE));
254 		fnic_dbg_prt->buffer_len =
255 			fnic_fc_trace_get_data(fnic_dbg_prt, *rdata_ptr);
256 	}
257 	file->private_data = fnic_dbg_prt;
258 
259 	return 0;
260 }
261 
262 /*
263  * fnic_trace_debugfs_lseek - Seek through a debugfs file
264  * @file: The file pointer to seek through.
265  * @offset: The offset to seek to or the amount to seek by.
266  * @howto: Indicates how to seek.
267  *
268  * Description:
269  * This routine is the entry point for the debugfs lseek file operation.
270  * The @howto parameter indicates whether @offset is the offset to directly
271  * seek to, or if it is a value to seek forward or reverse by. This function
272  * figures out what the new offset of the debugfs file will be and assigns
273  * that value to the f_pos field of @file.
274  *
275  * Returns:
276  * This function returns the new offset if successful and returns a negative
277  * error if unable to process the seek.
278  */
279 static loff_t fnic_trace_debugfs_lseek(struct file *file,
280 					loff_t offset,
281 					int howto)
282 {
283 	fnic_dbgfs_t *fnic_dbg_prt = file->private_data;
284 	return fixed_size_llseek(file, offset, howto,
285 				fnic_dbg_prt->buffer_len);
286 }
287 
288 /*
289  * fnic_trace_debugfs_read - Read a debugfs file
290  * @file: The file pointer to read from.
291  * @ubuf: The buffer to copy the data to.
292  * @nbytes: The number of bytes to read.
293  * @pos: The position in the file to start reading from.
294  *
295  * Description:
296  * This routine reads data from the buffer indicated in the private_data
297  * field of @file. It will start reading at @pos and copy up to @nbytes of
298  * data to @ubuf.
299  *
300  * Returns:
301  * This function returns the amount of data that was read (this could be
302  * less than @nbytes if the end of the file was reached).
303  */
304 static ssize_t fnic_trace_debugfs_read(struct file *file,
305 					char __user *ubuf,
306 					size_t nbytes,
307 					loff_t *pos)
308 {
309 	fnic_dbgfs_t *fnic_dbg_prt = file->private_data;
310 	int rc = 0;
311 	rc = simple_read_from_buffer(ubuf, nbytes, pos,
312 				  fnic_dbg_prt->buffer,
313 				  fnic_dbg_prt->buffer_len);
314 	return rc;
315 }
316 
317 /*
318  * fnic_trace_debugfs_release - Release the buffer used to store
319  * debugfs file data
320  * @inode: The inode pointer
321  * @file: The file pointer that contains the buffer to release
322  *
323  * Description:
324  * This routine frees the buffer that was allocated when the debugfs
325  * file was opened.
326  *
327  * Returns:
328  * This function returns zero.
329  */
330 static int fnic_trace_debugfs_release(struct inode *inode,
331 					  struct file *file)
332 {
333 	fnic_dbgfs_t *fnic_dbg_prt = file->private_data;
334 
335 	vfree(fnic_dbg_prt->buffer);
336 	kfree(fnic_dbg_prt);
337 	return 0;
338 }
339 
340 static const struct file_operations fnic_trace_debugfs_fops = {
341 	.owner = THIS_MODULE,
342 	.open = fnic_trace_debugfs_open,
343 	.llseek = fnic_trace_debugfs_lseek,
344 	.read = fnic_trace_debugfs_read,
345 	.release = fnic_trace_debugfs_release,
346 };
347 
348 /*
349  * fnic_trace_debugfs_init - Initialize debugfs for fnic trace logging
350  *
351  * Description:
352  * When Debugfs is configured this routine sets up the fnic debugfs
353  * file system. If not already created, this routine will create the
354  * create file trace to log fnic trace buffer output into debugfs and
355  * it will also create file trace_enable to control enable/disable of
356  * trace logging into trace buffer.
357  */
358 int fnic_trace_debugfs_init(void)
359 {
360 	int rc = -1;
361 	if (!fnic_trace_debugfs_root) {
362 		printk(KERN_DEBUG
363 			"FNIC Debugfs root directory doesn't exist\n");
364 		return rc;
365 	}
366 	fnic_trace_enable = debugfs_create_file("tracing_enable",
367 					S_IFREG|S_IRUGO|S_IWUSR,
368 					fnic_trace_debugfs_root,
369 					&(fc_trc_flag->fnic_trace),
370 					&fnic_trace_ctrl_fops);
371 
372 	if (!fnic_trace_enable) {
373 		printk(KERN_DEBUG
374 			"Cannot create trace_enable file under debugfs\n");
375 		return rc;
376 	}
377 
378 	fnic_trace_debugfs_file = debugfs_create_file("trace",
379 					S_IFREG|S_IRUGO|S_IWUSR,
380 					fnic_trace_debugfs_root,
381 					&(fc_trc_flag->fnic_trace),
382 					&fnic_trace_debugfs_fops);
383 
384 	if (!fnic_trace_debugfs_file) {
385 		printk(KERN_DEBUG
386 			"Cannot create trace file under debugfs\n");
387 		return rc;
388 	}
389 	rc = 0;
390 	return rc;
391 }
392 
393 /*
394  * fnic_trace_debugfs_terminate - Tear down debugfs infrastructure
395  *
396  * Description:
397  * When Debugfs is configured this routine removes debugfs file system
398  * elements that are specific to fnic trace logging.
399  */
400 void fnic_trace_debugfs_terminate(void)
401 {
402 	debugfs_remove(fnic_trace_debugfs_file);
403 	fnic_trace_debugfs_file = NULL;
404 
405 	debugfs_remove(fnic_trace_enable);
406 	fnic_trace_enable = NULL;
407 }
408 
409 /*
410  * fnic_fc_trace_debugfs_init -
411  * Initialize debugfs for fnic control frame trace logging
412  *
413  * Description:
414  * When Debugfs is configured this routine sets up the fnic_fc debugfs
415  * file system. If not already created, this routine will create the
416  * create file trace to log fnic fc trace buffer output into debugfs and
417  * it will also create file fc_trace_enable to control enable/disable of
418  * trace logging into trace buffer.
419  */
420 
421 int fnic_fc_trace_debugfs_init(void)
422 {
423 	int rc = -1;
424 
425 	if (!fnic_trace_debugfs_root) {
426 		pr_err("fnic:Debugfs root directory doesn't exist\n");
427 		return rc;
428 	}
429 
430 	fnic_fc_trace_enable = debugfs_create_file("fc_trace_enable",
431 					S_IFREG|S_IRUGO|S_IWUSR,
432 					fnic_trace_debugfs_root,
433 					&(fc_trc_flag->fc_trace),
434 					&fnic_trace_ctrl_fops);
435 
436 	if (!fnic_fc_trace_enable) {
437 		pr_err("fnic: Failed create fc_trace_enable file\n");
438 		return rc;
439 	}
440 
441 	fnic_fc_trace_clear = debugfs_create_file("fc_trace_clear",
442 					S_IFREG|S_IRUGO|S_IWUSR,
443 					fnic_trace_debugfs_root,
444 					&(fc_trc_flag->fc_clear),
445 					&fnic_trace_ctrl_fops);
446 
447 	if (!fnic_fc_trace_clear) {
448 		pr_err("fnic: Failed to create fc_trace_enable file\n");
449 		return rc;
450 	}
451 
452 	fnic_fc_rdata_trace_debugfs_file =
453 		debugfs_create_file("fc_trace_rdata",
454 				    S_IFREG|S_IRUGO|S_IWUSR,
455 				    fnic_trace_debugfs_root,
456 				    &(fc_trc_flag->fc_normal_file),
457 				    &fnic_trace_debugfs_fops);
458 
459 	if (!fnic_fc_rdata_trace_debugfs_file) {
460 		pr_err("fnic: Failed create fc_rdata_trace file\n");
461 		return rc;
462 	}
463 
464 	fnic_fc_trace_debugfs_file =
465 		debugfs_create_file("fc_trace",
466 				    S_IFREG|S_IRUGO|S_IWUSR,
467 				    fnic_trace_debugfs_root,
468 				    &(fc_trc_flag->fc_row_file),
469 				    &fnic_trace_debugfs_fops);
470 
471 	if (!fnic_fc_trace_debugfs_file) {
472 		pr_err("fnic: Failed to create fc_trace file\n");
473 		return rc;
474 	}
475 	rc = 0;
476 	return rc;
477 }
478 
479 /*
480  * fnic_fc_trace_debugfs_terminate - Tear down debugfs infrastructure
481  *
482  * Description:
483  * When Debugfs is configured this routine removes debugfs file system
484  * elements that are specific to fnic_fc trace logging.
485  */
486 
487 void fnic_fc_trace_debugfs_terminate(void)
488 {
489 	debugfs_remove(fnic_fc_trace_debugfs_file);
490 	fnic_fc_trace_debugfs_file = NULL;
491 
492 	debugfs_remove(fnic_fc_rdata_trace_debugfs_file);
493 	fnic_fc_rdata_trace_debugfs_file = NULL;
494 
495 	debugfs_remove(fnic_fc_trace_enable);
496 	fnic_fc_trace_enable = NULL;
497 
498 	debugfs_remove(fnic_fc_trace_clear);
499 	fnic_fc_trace_clear = NULL;
500 }
501 
502 /*
503  * fnic_reset_stats_open - Open the reset_stats file
504  * @inode: The inode pointer.
505  * @file: The file pointer to attach the stats reset flag.
506  *
507  * Description:
508  * This routine opens a debugsfs file reset_stats and stores i_private data
509  * to debug structure to retrieve later for while performing other
510  * file oprations.
511  *
512  * Returns:
513  * This function returns zero if successful.
514  */
515 static int fnic_reset_stats_open(struct inode *inode, struct file *file)
516 {
517 	struct stats_debug_info *debug;
518 
519 	debug = kzalloc(sizeof(struct stats_debug_info), GFP_KERNEL);
520 	if (!debug)
521 		return -ENOMEM;
522 
523 	debug->i_private = inode->i_private;
524 
525 	file->private_data = debug;
526 
527 	return 0;
528 }
529 
530 /*
531  * fnic_reset_stats_read - Read a reset_stats debugfs file
532  * @filp: The file pointer to read from.
533  * @ubuf: The buffer to copy the data to.
534  * @cnt: The number of bytes to read.
535  * @ppos: The position in the file to start reading from.
536  *
537  * Description:
538  * This routine reads value of variable reset_stats
539  * and stores into local @buf. It will start reading file at @ppos and
540  * copy up to @cnt of data to @ubuf from @buf.
541  *
542  * Returns:
543  * This function returns the amount of data that was read.
544  */
545 static ssize_t fnic_reset_stats_read(struct file *file,
546 					char __user *ubuf,
547 					size_t cnt, loff_t *ppos)
548 {
549 	struct stats_debug_info *debug = file->private_data;
550 	struct fnic *fnic = (struct fnic *)debug->i_private;
551 	char buf[64];
552 	int len;
553 
554 	len = sprintf(buf, "%u\n", fnic->reset_stats);
555 
556 	return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
557 }
558 
559 /*
560  * fnic_reset_stats_write - Write to reset_stats debugfs file
561  * @filp: The file pointer to write from.
562  * @ubuf: The buffer to copy the data from.
563  * @cnt: The number of bytes to write.
564  * @ppos: The position in the file to start writing to.
565  *
566  * Description:
567  * This routine writes data from user buffer @ubuf to buffer @buf and
568  * resets cumulative stats of fnic.
569  *
570  * Returns:
571  * This function returns the amount of data that was written.
572  */
573 static ssize_t fnic_reset_stats_write(struct file *file,
574 					const char __user *ubuf,
575 					size_t cnt, loff_t *ppos)
576 {
577 	struct stats_debug_info *debug = file->private_data;
578 	struct fnic *fnic = (struct fnic *)debug->i_private;
579 	struct fnic_stats *stats = &fnic->fnic_stats;
580 	u64 *io_stats_p = (u64 *)&stats->io_stats;
581 	u64 *fw_stats_p = (u64 *)&stats->fw_stats;
582 	char buf[64];
583 	unsigned long val;
584 	int ret;
585 
586 	if (cnt >= sizeof(buf))
587 		return -EINVAL;
588 
589 	if (copy_from_user(&buf, ubuf, cnt))
590 		return -EFAULT;
591 
592 	buf[cnt] = 0;
593 
594 	ret = kstrtoul(buf, 10, &val);
595 	if (ret < 0)
596 		return ret;
597 
598 	fnic->reset_stats = val;
599 
600 	if (fnic->reset_stats) {
601 		/* Skip variable is used to avoid descrepancies to Num IOs
602 		 * and IO Completions stats. Skip incrementing No IO Compls
603 		 * for pending active IOs after reset stats
604 		 */
605 		atomic64_set(&fnic->io_cmpl_skip,
606 			atomic64_read(&stats->io_stats.active_ios));
607 		memset(&stats->abts_stats, 0, sizeof(struct abort_stats));
608 		memset(&stats->term_stats, 0,
609 			sizeof(struct terminate_stats));
610 		memset(&stats->reset_stats, 0, sizeof(struct reset_stats));
611 		memset(&stats->misc_stats, 0, sizeof(struct misc_stats));
612 		memset(&stats->vlan_stats, 0, sizeof(struct vlan_stats));
613 		memset(io_stats_p+1, 0,
614 			sizeof(struct io_path_stats) - sizeof(u64));
615 		memset(fw_stats_p+1, 0,
616 			sizeof(struct fw_stats) - sizeof(u64));
617 		ktime_get_real_ts64(&stats->stats_timestamps.last_reset_time);
618 	}
619 
620 	(*ppos)++;
621 	return cnt;
622 }
623 
624 /*
625  * fnic_reset_stats_release - Release the buffer used to store
626  * debugfs file data
627  * @inode: The inode pointer
628  * @file: The file pointer that contains the buffer to release
629  *
630  * Description:
631  * This routine frees the buffer that was allocated when the debugfs
632  * file was opened.
633  *
634  * Returns:
635  * This function returns zero.
636  */
637 static int fnic_reset_stats_release(struct inode *inode,
638 					struct file *file)
639 {
640 	struct stats_debug_info *debug = file->private_data;
641 	kfree(debug);
642 	return 0;
643 }
644 
645 /*
646  * fnic_stats_debugfs_open - Open the stats file for specific host
647  * and get fnic stats.
648  * @inode: The inode pointer.
649  * @file: The file pointer to attach the specific host statistics.
650  *
651  * Description:
652  * This routine opens a debugsfs file stats of specific host and print
653  * fnic stats.
654  *
655  * Returns:
656  * This function returns zero if successful.
657  */
658 static int fnic_stats_debugfs_open(struct inode *inode,
659 					struct file *file)
660 {
661 	struct fnic *fnic = inode->i_private;
662 	struct fnic_stats *fnic_stats = &fnic->fnic_stats;
663 	struct stats_debug_info *debug;
664 	int buf_size = 2 * PAGE_SIZE;
665 
666 	debug = kzalloc(sizeof(struct stats_debug_info), GFP_KERNEL);
667 	if (!debug)
668 		return -ENOMEM;
669 
670 	debug->debug_buffer = vmalloc(buf_size);
671 	if (!debug->debug_buffer) {
672 		kfree(debug);
673 		return -ENOMEM;
674 	}
675 
676 	debug->buf_size = buf_size;
677 	memset((void *)debug->debug_buffer, 0, buf_size);
678 	debug->buffer_len = fnic_get_stats_data(debug, fnic_stats);
679 
680 	file->private_data = debug;
681 
682 	return 0;
683 }
684 
685 /*
686  * fnic_stats_debugfs_read - Read a debugfs file
687  * @file: The file pointer to read from.
688  * @ubuf: The buffer to copy the data to.
689  * @nbytes: The number of bytes to read.
690  * @pos: The position in the file to start reading from.
691  *
692  * Description:
693  * This routine reads data from the buffer indicated in the private_data
694  * field of @file. It will start reading at @pos and copy up to @nbytes of
695  * data to @ubuf.
696  *
697  * Returns:
698  * This function returns the amount of data that was read (this could be
699  * less than @nbytes if the end of the file was reached).
700  */
701 static ssize_t fnic_stats_debugfs_read(struct file *file,
702 					char __user *ubuf,
703 					size_t nbytes,
704 					loff_t *pos)
705 {
706 	struct stats_debug_info *debug = file->private_data;
707 	int rc = 0;
708 	rc = simple_read_from_buffer(ubuf, nbytes, pos,
709 					debug->debug_buffer,
710 					debug->buffer_len);
711 	return rc;
712 }
713 
714 /*
715  * fnic_stats_stats_release - Release the buffer used to store
716  * debugfs file data
717  * @inode: The inode pointer
718  * @file: The file pointer that contains the buffer to release
719  *
720  * Description:
721  * This routine frees the buffer that was allocated when the debugfs
722  * file was opened.
723  *
724  * Returns:
725  * This function returns zero.
726  */
727 static int fnic_stats_debugfs_release(struct inode *inode,
728 					struct file *file)
729 {
730 	struct stats_debug_info *debug = file->private_data;
731 	vfree(debug->debug_buffer);
732 	kfree(debug);
733 	return 0;
734 }
735 
736 static const struct file_operations fnic_stats_debugfs_fops = {
737 	.owner = THIS_MODULE,
738 	.open = fnic_stats_debugfs_open,
739 	.read = fnic_stats_debugfs_read,
740 	.release = fnic_stats_debugfs_release,
741 };
742 
743 static const struct file_operations fnic_reset_debugfs_fops = {
744 	.owner = THIS_MODULE,
745 	.open = fnic_reset_stats_open,
746 	.read = fnic_reset_stats_read,
747 	.write = fnic_reset_stats_write,
748 	.release = fnic_reset_stats_release,
749 };
750 
751 /*
752  * fnic_stats_init - Initialize stats struct and create stats file per fnic
753  *
754  * Description:
755  * When Debugfs is configured this routine sets up the stats file per fnic
756  * It will create file stats and reset_stats under statistics/host# directory
757  * to log per fnic stats.
758  */
759 int fnic_stats_debugfs_init(struct fnic *fnic)
760 {
761 	int rc = -1;
762 	char name[16];
763 
764 	snprintf(name, sizeof(name), "host%d", fnic->lport->host->host_no);
765 
766 	if (!fnic_stats_debugfs_root) {
767 		printk(KERN_DEBUG "fnic_stats root doesn't exist\n");
768 		return rc;
769 	}
770 	fnic->fnic_stats_debugfs_host = debugfs_create_dir(name,
771 						fnic_stats_debugfs_root);
772 	if (!fnic->fnic_stats_debugfs_host) {
773 		printk(KERN_DEBUG "Cannot create host directory\n");
774 		return rc;
775 	}
776 
777 	fnic->fnic_stats_debugfs_file = debugfs_create_file("stats",
778 						S_IFREG|S_IRUGO|S_IWUSR,
779 						fnic->fnic_stats_debugfs_host,
780 						fnic,
781 						&fnic_stats_debugfs_fops);
782 	if (!fnic->fnic_stats_debugfs_file) {
783 		printk(KERN_DEBUG "Cannot create host stats file\n");
784 		return rc;
785 	}
786 
787 	fnic->fnic_reset_debugfs_file = debugfs_create_file("reset_stats",
788 						S_IFREG|S_IRUGO|S_IWUSR,
789 						fnic->fnic_stats_debugfs_host,
790 						fnic,
791 						&fnic_reset_debugfs_fops);
792 	if (!fnic->fnic_reset_debugfs_file) {
793 		printk(KERN_DEBUG "Cannot create host stats file\n");
794 		return rc;
795 	}
796 	rc = 0;
797 	return rc;
798 }
799 
800 /*
801  * fnic_stats_debugfs_remove - Tear down debugfs infrastructure of stats
802  *
803  * Description:
804  * When Debugfs is configured this routine removes debugfs file system
805  * elements that are specific to fnic stats.
806  */
807 void fnic_stats_debugfs_remove(struct fnic *fnic)
808 {
809 	if (!fnic)
810 		return;
811 
812 	debugfs_remove(fnic->fnic_stats_debugfs_file);
813 	fnic->fnic_stats_debugfs_file = NULL;
814 
815 	debugfs_remove(fnic->fnic_reset_debugfs_file);
816 	fnic->fnic_reset_debugfs_file = NULL;
817 
818 	debugfs_remove(fnic->fnic_stats_debugfs_host);
819 	fnic->fnic_stats_debugfs_host = NULL;
820 }
821