drivers/scsi/fnic/fnic_debugfs.c

   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         fnic_trace_debugfs_root = debugfs_create_dir("fnic", NULL);
  56
  57         fnic_stats_debugfs_root = debugfs_create_dir("statistics",
  58                                                 fnic_trace_debugfs_root);
  59
  60         /* Allocate memory to structure */
  61         fc_trc_flag = (struct fc_trace_flag_type *)
  62                 vmalloc(sizeof(struct fc_trace_flag_type));
  63
  64         if (fc_trc_flag) {
  65                 fc_trc_flag->fc_row_file = 0;
  66                 fc_trc_flag->fc_normal_file = 1;
  67                 fc_trc_flag->fnic_trace = 2;
  68                 fc_trc_flag->fc_trace = 3;
  69                 fc_trc_flag->fc_clear = 4;
  70         }
  71
  72         return 0;
  73 }
  74
  75 /*
  76  * fnic_debugfs_terminate - Tear down debugfs infrastructure
  77  *
  78  * Description:
  79  * When Debugfs is configured this routine removes debugfs file system
  80  * elements that are specific to fnic.
  81  */
  82 void fnic_debugfs_terminate(void)
  83 {
  84         debugfs_remove(fnic_stats_debugfs_root);
  85         fnic_stats_debugfs_root = NULL;
  86
  87         debugfs_remove(fnic_trace_debugfs_root);
  88         fnic_trace_debugfs_root = NULL;
  89
  90         if (fc_trc_flag)
  91                 vfree(fc_trc_flag);
  92 }
  93
  94 /*
  95  * fnic_trace_ctrl_read -
  96  *          Read  trace_enable ,fc_trace_enable
  97  *              or fc_trace_clear debugfs file
  98  * @filp: The file pointer to read from.
  99  * @ubuf: The buffer to copy the data to.
 100  * @cnt: The number of bytes to read.
 101  * @ppos: The position in the file to start reading from.
 102  *
 103  * Description:
 104  * This routine reads value of variable fnic_tracing_enabled or
 105  * fnic_fc_tracing_enabled or fnic_fc_trace_cleared
 106  * and stores into local @buf.
 107  * It will start reading file at @ppos and
 108  * copy up to @cnt of data to @ubuf from @buf.
 109  *
 110  * Returns:
 111  * This function returns the amount of data that was read.
 112  */
 113 static ssize_t fnic_trace_ctrl_read(struct file *filp,
 114                                   char __user *ubuf,
 115                                   size_t cnt, loff_t *ppos)
 116 {
 117         char buf[64];
 118         int len;
 119         u8 *trace_type;
 120         len = 0;
 121         trace_type = (u8 *)filp->private_data;
 122         if (*trace_type == fc_trc_flag->fnic_trace)
 123                 len = sprintf(buf, "%d\n", fnic_tracing_enabled);
 124         else if (*trace_type == fc_trc_flag->fc_trace)
 125                 len = sprintf(buf, "%d\n", fnic_fc_tracing_enabled);
 126         else if (*trace_type == fc_trc_flag->fc_clear)
 127                 len = sprintf(buf, "%d\n", fnic_fc_trace_cleared);
 128         else
 129                 pr_err("fnic: Cannot read to any debugfs file\n");
 130
 131         return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
 132 }
 133
 134 /*
 135  * fnic_trace_ctrl_write -
 136  * Write to trace_enable, fc_trace_enable or
 137  *         fc_trace_clear debugfs file
 138  * @filp: The file pointer to write from.
 139  * @ubuf: The buffer to copy the data from.
 140  * @cnt: The number of bytes to write.
 141  * @ppos: The position in the file to start writing to.
 142  *
 143  * Description:
 144  * This routine writes data from user buffer @ubuf to buffer @buf and
 145  * sets fc_trace_enable ,tracing_enable or fnic_fc_trace_cleared
 146  * value as per user input.
 147  *
 148  * Returns:
 149  * This function returns the amount of data that was written.
 150  */
 151 static ssize_t fnic_trace_ctrl_write(struct file *filp,
 152                                   const char __user *ubuf,
 153                                   size_t cnt, loff_t *ppos)
 154 {
 155         char buf[64];
 156         unsigned long val;
 157         int ret;
 158         u8 *trace_type;
 159         trace_type = (u8 *)filp->private_data;
 160
 161         if (cnt >= sizeof(buf))
 162                 return -EINVAL;
 163
 164         if (copy_from_user(&buf, ubuf, cnt))
 165                 return -EFAULT;
 166
 167         buf[cnt] = 0;
 168
 169         ret = kstrtoul(buf, 10, &val);
 170         if (ret < 0)
 171                 return ret;
 172
 173         if (*trace_type == fc_trc_flag->fnic_trace)
 174                 fnic_tracing_enabled = val;
 175         else if (*trace_type == fc_trc_flag->fc_trace)
 176                 fnic_fc_tracing_enabled = val;
 177         else if (*trace_type == fc_trc_flag->fc_clear)
 178                 fnic_fc_trace_cleared = val;
 179         else
 180                 pr_err("fnic: cannot write to any debugfs file\n");
 181
 182         (*ppos)++;
 183
 184         return cnt;
 185 }
 186
 187 static const struct file_operations fnic_trace_ctrl_fops = {
 188         .owner = THIS_MODULE,
 189         .open = simple_open,
 190         .read = fnic_trace_ctrl_read,
 191         .write = fnic_trace_ctrl_write,
 192 };
 193
 194 /*
 195  * fnic_trace_debugfs_open - Open the fnic trace log
 196  * @inode: The inode pointer
 197  * @file: The file pointer to attach the log output
 198  *
 199  * Description:
 200  * This routine is the entry point for the debugfs open file operation.
 201  * It allocates the necessary buffer for the log, fills the buffer from
 202  * the in-memory log and then returns a pointer to that log in
 203  * the private_data field in @file.
 204  *
 205  * Returns:
 206  * This function returns zero if successful. On error it will return
 207  * a negative error value.
 208  */
 209 static int fnic_trace_debugfs_open(struct inode *inode,
 210                                   struct file *file)
 211 {
 212         fnic_dbgfs_t *fnic_dbg_prt;
 213         u8 *rdata_ptr;
 214         rdata_ptr = (u8 *)inode->i_private;
 215         fnic_dbg_prt = kzalloc(sizeof(fnic_dbgfs_t), GFP_KERNEL);
 216         if (!fnic_dbg_prt)
 217                 return -ENOMEM;
 218
 219         if (*rdata_ptr == fc_trc_flag->fnic_trace) {
 220                 fnic_dbg_prt->buffer = vmalloc(array3_size(3, trace_max_pages,
 221                                                            PAGE_SIZE));
 222                 if (!fnic_dbg_prt->buffer) {
 223                         kfree(fnic_dbg_prt);
 224                         return -ENOMEM;
 225                 }
 226                 memset((void *)fnic_dbg_prt->buffer, 0,
 227                 3 * (trace_max_pages * PAGE_SIZE));
 228                 fnic_dbg_prt->buffer_len = fnic_get_trace_data(fnic_dbg_prt);
 229         } else {
 230                 fnic_dbg_prt->buffer =
 231                         vmalloc(array3_size(3, fnic_fc_trace_max_pages,
 232                                             PAGE_SIZE));
 233                 if (!fnic_dbg_prt->buffer) {
 234                         kfree(fnic_dbg_prt);
 235                         return -ENOMEM;
 236                 }
 237                 memset((void *)fnic_dbg_prt->buffer, 0,
 238                         3 * (fnic_fc_trace_max_pages * PAGE_SIZE));
 239                 fnic_dbg_prt->buffer_len =
 240                         fnic_fc_trace_get_data(fnic_dbg_prt, *rdata_ptr);
 241         }
 242         file->private_data = fnic_dbg_prt;
 243
 244         return 0;
 245 }
 246
 247 /*
 248  * fnic_trace_debugfs_lseek - Seek through a debugfs file
 249  * @file: The file pointer to seek through.
 250  * @offset: The offset to seek to or the amount to seek by.
 251  * @howto: Indicates how to seek.
 252  *
 253  * Description:
 254  * This routine is the entry point for the debugfs lseek file operation.
 255  * The @howto parameter indicates whether @offset is the offset to directly
 256  * seek to, or if it is a value to seek forward or reverse by. This function
 257  * figures out what the new offset of the debugfs file will be and assigns
 258  * that value to the f_pos field of @file.
 259  *
 260  * Returns:
 261  * This function returns the new offset if successful and returns a negative
 262  * error if unable to process the seek.
 263  */
 264 static loff_t fnic_trace_debugfs_lseek(struct file *file,
 265                                         loff_t offset,
 266                                         int howto)
 267 {
 268         fnic_dbgfs_t *fnic_dbg_prt = file->private_data;
 269         return fixed_size_llseek(file, offset, howto,
 270                                 fnic_dbg_prt->buffer_len);
 271 }
 272
 273 /*
 274  * fnic_trace_debugfs_read - Read a debugfs file
 275  * @file: The file pointer to read from.
 276  * @ubuf: The buffer to copy the data to.
 277  * @nbytes: The number of bytes to read.
 278  * @pos: The position in the file to start reading from.
 279  *
 280  * Description:
 281  * This routine reads data from the buffer indicated in the private_data
 282  * field of @file. It will start reading at @pos and copy up to @nbytes of
 283  * data to @ubuf.
 284  *
 285  * Returns:
 286  * This function returns the amount of data that was read (this could be
 287  * less than @nbytes if the end of the file was reached).
 288  */
 289 static ssize_t fnic_trace_debugfs_read(struct file *file,
 290                                         char __user *ubuf,
 291                                         size_t nbytes,
 292                                         loff_t *pos)
 293 {
 294         fnic_dbgfs_t *fnic_dbg_prt = file->private_data;
 295         int rc = 0;
 296         rc = simple_read_from_buffer(ubuf, nbytes, pos,
 297                                   fnic_dbg_prt->buffer,
 298                                   fnic_dbg_prt->buffer_len);
 299         return rc;
 300 }
 301
 302 /*
 303  * fnic_trace_debugfs_release - Release the buffer used to store
 304  * debugfs file data
 305  * @inode: The inode pointer
 306  * @file: The file pointer that contains the buffer to release
 307  *
 308  * Description:
 309  * This routine frees the buffer that was allocated when the debugfs
 310  * file was opened.
 311  *
 312  * Returns:
 313  * This function returns zero.
 314  */
 315 static int fnic_trace_debugfs_release(struct inode *inode,
 316                                           struct file *file)
 317 {
 318         fnic_dbgfs_t *fnic_dbg_prt = file->private_data;
 319
 320         vfree(fnic_dbg_prt->buffer);
 321         kfree(fnic_dbg_prt);
 322         return 0;
 323 }
 324
 325 static const struct file_operations fnic_trace_debugfs_fops = {
 326         .owner = THIS_MODULE,
 327         .open = fnic_trace_debugfs_open,
 328         .llseek = fnic_trace_debugfs_lseek,
 329         .read = fnic_trace_debugfs_read,
 330         .release = fnic_trace_debugfs_release,
 331 };
 332
 333 /*
 334  * fnic_trace_debugfs_init - Initialize debugfs for fnic trace logging
 335  *
 336  * Description:
 337  * When Debugfs is configured this routine sets up the fnic debugfs
 338  * file system. If not already created, this routine will create the
 339  * create file trace to log fnic trace buffer output into debugfs and
 340  * it will also create file trace_enable to control enable/disable of
 341  * trace logging into trace buffer.
 342  */
 343 void fnic_trace_debugfs_init(void)
 344 {
 345         fnic_trace_enable = debugfs_create_file("tracing_enable",
 346                                         S_IFREG|S_IRUGO|S_IWUSR,
 347                                         fnic_trace_debugfs_root,
 348                                         &(fc_trc_flag->fnic_trace),
 349                                         &fnic_trace_ctrl_fops);
 350
 351         fnic_trace_debugfs_file = debugfs_create_file("trace",
 352                                         S_IFREG|S_IRUGO|S_IWUSR,
 353                                         fnic_trace_debugfs_root,
 354                                         &(fc_trc_flag->fnic_trace),
 355                                         &fnic_trace_debugfs_fops);
 356 }
 357
 358 /*
 359  * fnic_trace_debugfs_terminate - Tear down debugfs infrastructure
 360  *
 361  * Description:
 362  * When Debugfs is configured this routine removes debugfs file system
 363  * elements that are specific to fnic trace logging.
 364  */
 365 void fnic_trace_debugfs_terminate(void)
 366 {
 367         debugfs_remove(fnic_trace_debugfs_file);
 368         fnic_trace_debugfs_file = NULL;
 369
 370         debugfs_remove(fnic_trace_enable);
 371         fnic_trace_enable = NULL;
 372 }
 373
 374 /*
 375  * fnic_fc_trace_debugfs_init -
 376  * Initialize debugfs for fnic control frame trace logging
 377  *
 378  * Description:
 379  * When Debugfs is configured this routine sets up the fnic_fc debugfs
 380  * file system. If not already created, this routine will create the
 381  * create file trace to log fnic fc trace buffer output into debugfs and
 382  * it will also create file fc_trace_enable to control enable/disable of
 383  * trace logging into trace buffer.
 384  */
 385
 386 void fnic_fc_trace_debugfs_init(void)
 387 {
 388         fnic_fc_trace_enable = debugfs_create_file("fc_trace_enable",
 389                                         S_IFREG|S_IRUGO|S_IWUSR,
 390                                         fnic_trace_debugfs_root,
 391                                         &(fc_trc_flag->fc_trace),
 392                                         &fnic_trace_ctrl_fops);
 393
 394         fnic_fc_trace_clear = debugfs_create_file("fc_trace_clear",
 395                                         S_IFREG|S_IRUGO|S_IWUSR,
 396                                         fnic_trace_debugfs_root,
 397                                         &(fc_trc_flag->fc_clear),
 398                                         &fnic_trace_ctrl_fops);
 399
 400         fnic_fc_rdata_trace_debugfs_file =
 401                 debugfs_create_file("fc_trace_rdata",
 402                                     S_IFREG|S_IRUGO|S_IWUSR,
 403                                     fnic_trace_debugfs_root,
 404                                     &(fc_trc_flag->fc_normal_file),
 405                                     &fnic_trace_debugfs_fops);
 406
 407         fnic_fc_trace_debugfs_file =
 408                 debugfs_create_file("fc_trace",
 409                                     S_IFREG|S_IRUGO|S_IWUSR,
 410                                     fnic_trace_debugfs_root,
 411                                     &(fc_trc_flag->fc_row_file),
 412                                     &fnic_trace_debugfs_fops);
 413 }
 414
 415 /*
 416  * fnic_fc_trace_debugfs_terminate - Tear down debugfs infrastructure
 417  *
 418  * Description:
 419  * When Debugfs is configured this routine removes debugfs file system
 420  * elements that are specific to fnic_fc trace logging.
 421  */
 422
 423 void fnic_fc_trace_debugfs_terminate(void)
 424 {
 425         debugfs_remove(fnic_fc_trace_debugfs_file);
 426         fnic_fc_trace_debugfs_file = NULL;
 427
 428         debugfs_remove(fnic_fc_rdata_trace_debugfs_file);
 429         fnic_fc_rdata_trace_debugfs_file = NULL;
 430
 431         debugfs_remove(fnic_fc_trace_enable);
 432         fnic_fc_trace_enable = NULL;
 433
 434         debugfs_remove(fnic_fc_trace_clear);
 435         fnic_fc_trace_clear = NULL;
 436 }
 437
 438 /*
 439  * fnic_reset_stats_open - Open the reset_stats file
 440  * @inode: The inode pointer.
 441  * @file: The file pointer to attach the stats reset flag.
 442  *
 443  * Description:
 444  * This routine opens a debugsfs file reset_stats and stores i_private data
 445  * to debug structure to retrieve later for while performing other
 446  * file oprations.
 447  *
 448  * Returns:
 449  * This function returns zero if successful.
 450  */
 451 static int fnic_reset_stats_open(struct inode *inode, struct file *file)
 452 {
 453         struct stats_debug_info *debug;
 454
 455         debug = kzalloc(sizeof(struct stats_debug_info), GFP_KERNEL);
 456         if (!debug)
 457                 return -ENOMEM;
 458
 459         debug->i_private = inode->i_private;
 460
 461         file->private_data = debug;
 462
 463         return 0;
 464 }
 465
 466 /*
 467  * fnic_reset_stats_read - Read a reset_stats debugfs file
 468  * @filp: The file pointer to read from.
 469  * @ubuf: The buffer to copy the data to.
 470  * @cnt: The number of bytes to read.
 471  * @ppos: The position in the file to start reading from.
 472  *
 473  * Description:
 474  * This routine reads value of variable reset_stats
 475  * and stores into local @buf. It will start reading file at @ppos and
 476  * copy up to @cnt of data to @ubuf from @buf.
 477  *
 478  * Returns:
 479  * This function returns the amount of data that was read.
 480  */
 481 static ssize_t fnic_reset_stats_read(struct file *file,
 482                                         char __user *ubuf,
 483                                         size_t cnt, loff_t *ppos)
 484 {
 485         struct stats_debug_info *debug = file->private_data;
 486         struct fnic *fnic = (struct fnic *)debug->i_private;
 487         char buf[64];
 488         int len;
 489
 490         len = sprintf(buf, "%u\n", fnic->reset_stats);
 491
 492         return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
 493 }
 494
 495 /*
 496  * fnic_reset_stats_write - Write to reset_stats debugfs file
 497  * @filp: The file pointer to write from.
 498  * @ubuf: The buffer to copy the data from.
 499  * @cnt: The number of bytes to write.
 500  * @ppos: The position in the file to start writing to.
 501  *
 502  * Description:
 503  * This routine writes data from user buffer @ubuf to buffer @buf and
 504  * resets cumulative stats of fnic.
 505  *
 506  * Returns:
 507  * This function returns the amount of data that was written.
 508  */
 509 static ssize_t fnic_reset_stats_write(struct file *file,
 510                                         const char __user *ubuf,
 511                                         size_t cnt, loff_t *ppos)
 512 {
 513         struct stats_debug_info *debug = file->private_data;
 514         struct fnic *fnic = (struct fnic *)debug->i_private;
 515         struct fnic_stats *stats = &fnic->fnic_stats;
 516         u64 *io_stats_p = (u64 *)&stats->io_stats;
 517         u64 *fw_stats_p = (u64 *)&stats->fw_stats;
 518         char buf[64];
 519         unsigned long val;
 520         int ret;
 521
 522         if (cnt >= sizeof(buf))
 523                 return -EINVAL;
 524
 525         if (copy_from_user(&buf, ubuf, cnt))
 526                 return -EFAULT;
 527
 528         buf[cnt] = 0;
 529
 530         ret = kstrtoul(buf, 10, &val);
 531         if (ret < 0)
 532                 return ret;
 533
 534         fnic->reset_stats = val;
 535
 536         if (fnic->reset_stats) {
 537                 /* Skip variable is used to avoid descrepancies to Num IOs
 538                  * and IO Completions stats. Skip incrementing No IO Compls
 539                  * for pending active IOs after reset stats
 540                  */
 541                 atomic64_set(&fnic->io_cmpl_skip,
 542                         atomic64_read(&stats->io_stats.active_ios));
 543                 memset(&stats->abts_stats, 0, sizeof(struct abort_stats));
 544                 memset(&stats->term_stats, 0,
 545                         sizeof(struct terminate_stats));
 546                 memset(&stats->reset_stats, 0, sizeof(struct reset_stats));
 547                 memset(&stats->misc_stats, 0, sizeof(struct misc_stats));
 548                 memset(&stats->vlan_stats, 0, sizeof(struct vlan_stats));
 549                 memset(io_stats_p+1, 0,
 550                         sizeof(struct io_path_stats) - sizeof(u64));
 551                 memset(fw_stats_p+1, 0,
 552                         sizeof(struct fw_stats) - sizeof(u64));
 553                 ktime_get_real_ts64(&stats->stats_timestamps.last_reset_time);
 554         }
 555
 556         (*ppos)++;
 557         return cnt;
 558 }
 559
 560 /*
 561  * fnic_reset_stats_release - Release the buffer used to store
 562  * debugfs file data
 563  * @inode: The inode pointer
 564  * @file: The file pointer that contains the buffer to release
 565  *
 566  * Description:
 567  * This routine frees the buffer that was allocated when the debugfs
 568  * file was opened.
 569  *
 570  * Returns:
 571  * This function returns zero.
 572  */
 573 static int fnic_reset_stats_release(struct inode *inode,
 574                                         struct file *file)
 575 {
 576         struct stats_debug_info *debug = file->private_data;
 577         kfree(debug);
 578         return 0;
 579 }
 580
 581 /*
 582  * fnic_stats_debugfs_open - Open the stats file for specific host
 583  * and get fnic stats.
 584  * @inode: The inode pointer.
 585  * @file: The file pointer to attach the specific host statistics.
 586  *
 587  * Description:
 588  * This routine opens a debugsfs file stats of specific host and print
 589  * fnic stats.
 590  *
 591  * Returns:
 592  * This function returns zero if successful.
 593  */
 594 static int fnic_stats_debugfs_open(struct inode *inode,
 595                                         struct file *file)
 596 {
 597         struct fnic *fnic = inode->i_private;
 598         struct fnic_stats *fnic_stats = &fnic->fnic_stats;
 599         struct stats_debug_info *debug;
 600         int buf_size = 2 * PAGE_SIZE;
 601
 602         debug = kzalloc(sizeof(struct stats_debug_info), GFP_KERNEL);
 603         if (!debug)
 604                 return -ENOMEM;
 605
 606         debug->debug_buffer = vmalloc(buf_size);
 607         if (!debug->debug_buffer) {
 608                 kfree(debug);
 609                 return -ENOMEM;
 610         }
 611
 612         debug->buf_size = buf_size;
 613         memset((void *)debug->debug_buffer, 0, buf_size);
 614         debug->buffer_len = fnic_get_stats_data(debug, fnic_stats);
 615
 616         file->private_data = debug;
 617
 618         return 0;
 619 }
 620
 621 /*
 622  * fnic_stats_debugfs_read - Read a debugfs file
 623  * @file: The file pointer to read from.
 624  * @ubuf: The buffer to copy the data to.
 625  * @nbytes: The number of bytes to read.
 626  * @pos: The position in the file to start reading from.
 627  *
 628  * Description:
 629  * This routine reads data from the buffer indicated in the private_data
 630  * field of @file. It will start reading at @pos and copy up to @nbytes of
 631  * data to @ubuf.
 632  *
 633  * Returns:
 634  * This function returns the amount of data that was read (this could be
 635  * less than @nbytes if the end of the file was reached).
 636  */
 637 static ssize_t fnic_stats_debugfs_read(struct file *file,
 638                                         char __user *ubuf,
 639                                         size_t nbytes,
 640                                         loff_t *pos)
 641 {
 642         struct stats_debug_info *debug = file->private_data;
 643         int rc = 0;
 644         rc = simple_read_from_buffer(ubuf, nbytes, pos,
 645                                         debug->debug_buffer,
 646                                         debug->buffer_len);
 647         return rc;
 648 }
 649
 650 /*
 651  * fnic_stats_stats_release - Release the buffer used to store
 652  * debugfs file data
 653  * @inode: The inode pointer
 654  * @file: The file pointer that contains the buffer to release
 655  *
 656  * Description:
 657  * This routine frees the buffer that was allocated when the debugfs
 658  * file was opened.
 659  *
 660  * Returns:
 661  * This function returns zero.
 662  */
 663 static int fnic_stats_debugfs_release(struct inode *inode,
 664                                         struct file *file)
 665 {
 666         struct stats_debug_info *debug = file->private_data;
 667         vfree(debug->debug_buffer);
 668         kfree(debug);
 669         return 0;
 670 }
 671
 672 static const struct file_operations fnic_stats_debugfs_fops = {
 673         .owner = THIS_MODULE,
 674         .open = fnic_stats_debugfs_open,
 675         .read = fnic_stats_debugfs_read,
 676         .release = fnic_stats_debugfs_release,
 677 };
 678
 679 static const struct file_operations fnic_reset_debugfs_fops = {
 680         .owner = THIS_MODULE,
 681         .open = fnic_reset_stats_open,
 682         .read = fnic_reset_stats_read,
 683         .write = fnic_reset_stats_write,
 684         .release = fnic_reset_stats_release,
 685 };
 686
 687 /*
 688  * fnic_stats_init - Initialize stats struct and create stats file per fnic
 689  *
 690  * Description:
 691  * When Debugfs is configured this routine sets up the stats file per fnic
 692  * It will create file stats and reset_stats under statistics/host# directory
 693  * to log per fnic stats.
 694  */
 695 void fnic_stats_debugfs_init(struct fnic *fnic)
 696 {
 697         char name[16];
 698
 699         snprintf(name, sizeof(name), "host%d", fnic->lport->host->host_no);
 700
 701         fnic->fnic_stats_debugfs_host = debugfs_create_dir(name,
 702                                                 fnic_stats_debugfs_root);
 703
 704         fnic->fnic_stats_debugfs_file = debugfs_create_file("stats",
 705                                                 S_IFREG|S_IRUGO|S_IWUSR,
 706                                                 fnic->fnic_stats_debugfs_host,
 707                                                 fnic,
 708                                                 &fnic_stats_debugfs_fops);
 709
 710         fnic->fnic_reset_debugfs_file = debugfs_create_file("reset_stats",
 711                                                 S_IFREG|S_IRUGO|S_IWUSR,
 712                                                 fnic->fnic_stats_debugfs_host,
 713                                                 fnic,
 714                                                 &fnic_reset_debugfs_fops);
 715 }
 716
 717 /*
 718  * fnic_stats_debugfs_remove - Tear down debugfs infrastructure of stats
 719  *
 720  * Description:
 721  * When Debugfs is configured this routine removes debugfs file system
 722  * elements that are specific to fnic stats.
 723  */
 724 void fnic_stats_debugfs_remove(struct fnic *fnic)
 725 {
 726         if (!fnic)
 727                 return;
 728
 729         debugfs_remove(fnic->fnic_stats_debugfs_file);
 730         fnic->fnic_stats_debugfs_file = NULL;
 731
 732         debugfs_remove(fnic->fnic_reset_debugfs_file);
 733         fnic->fnic_reset_debugfs_file = NULL;
 734
 735         debugfs_remove(fnic->fnic_stats_debugfs_host);
 736         fnic->fnic_stats_debugfs_host = NULL;
 737 }