drivers/infiniband/hw/ipath/ipath_fs.c

   1 /*
   2  * Copyright (c) 2006, 2007 QLogic Corporation. All rights reserved.
   3  * Copyright (c) 2006 PathScale, Inc. All rights reserved.
   4  *
   5  * This software is available to you under a choice of one of two
   6  * licenses.  You may choose to be licensed under the terms of the GNU
   7  * General Public License (GPL) Version 2, available from the file
   8  * COPYING in the main directory of this source tree, or the
   9  * OpenIB.org BSD license below:
  10  *
  11  *     Redistribution and use in source and binary forms, with or
  12  *     without modification, are permitted provided that the following
  13  *     conditions are met:
  14  *
  15  *      - Redistributions of source code must retain the above
  16  *        copyright notice, this list of conditions and the following
  17  *        disclaimer.
  18  *
  19  *      - Redistributions in binary form must reproduce the above
  20  *        copyright notice, this list of conditions and the following
  21  *        disclaimer in the documentation and/or other materials
  22  *        provided with the distribution.
  23  *
  24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  25  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  26  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  27  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  28  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  29  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  30  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  31  * SOFTWARE.
  32  */
  33
  34 #include <linux/module.h>
  35 #include <linux/fs.h>
  36 #include <linux/mount.h>
  37 #include <linux/pagemap.h>
  38 #include <linux/init.h>
  39 #include <linux/namei.h>
  40 #include <linux/slab.h>
  41
  42 #include "ipath_kernel.h"
  43
  44 #define IPATHFS_MAGIC 0x726a77
  45
  46 static struct super_block *ipath_super;
  47
  48 static int ipathfs_mknod(struct inode *dir, struct dentry *dentry,
  49                          int mode, const struct file_operations *fops,
  50                          void *data)
  51 {
  52         int error;
  53         struct inode *inode = new_inode(dir->i_sb);
  54
  55         if (!inode) {
  56                 error = -EPERM;
  57                 goto bail;
  58         }
  59
  60         inode->i_mode = mode;
  61         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
  62         inode->i_private = data;
  63         if ((mode & S_IFMT) == S_IFDIR) {
  64                 inode->i_op = &simple_dir_inode_operations;
  65                 inc_nlink(inode);
  66                 inc_nlink(dir);
  67         }
  68
  69         inode->i_fop = fops;
  70
  71         d_instantiate(dentry, inode);
  72         error = 0;
  73
  74 bail:
  75         return error;
  76 }
  77
  78 static int create_file(const char *name, mode_t mode,
  79                        struct dentry *parent, struct dentry **dentry,
  80                        const struct file_operations *fops, void *data)
  81 {
  82         int error;
  83
  84         *dentry = NULL;
  85         mutex_lock(&parent->d_inode->i_mutex);
  86         *dentry = lookup_one_len(name, parent, strlen(name));
  87         if (!IS_ERR(*dentry))
  88                 error = ipathfs_mknod(parent->d_inode, *dentry,
  89                                       mode, fops, data);
  90         else
  91                 error = PTR_ERR(dentry);
  92         mutex_unlock(&parent->d_inode->i_mutex);
  93
  94         return error;
  95 }
  96
  97 static ssize_t atomic_stats_read(struct file *file, char __user *buf,
  98                                  size_t count, loff_t *ppos)
  99 {
 100         return simple_read_from_buffer(buf, count, ppos, &ipath_stats,
 101                                        sizeof ipath_stats);
 102 }
 103
 104 static const struct file_operations atomic_stats_ops = {
 105         .read = atomic_stats_read,
 106 };
 107
 108 static ssize_t atomic_counters_read(struct file *file, char __user *buf,
 109                                     size_t count, loff_t *ppos)
 110 {
 111         struct infinipath_counters counters;
 112         struct ipath_devdata *dd;
 113
 114         dd = file->f_path.dentry->d_inode->i_private;
 115         dd->ipath_f_read_counters(dd, &counters);
 116
 117         return simple_read_from_buffer(buf, count, ppos, &counters,
 118                                        sizeof counters);
 119 }
 120
 121 static const struct file_operations atomic_counters_ops = {
 122         .read = atomic_counters_read,
 123 };
 124
 125 static ssize_t flash_read(struct file *file, char __user *buf,
 126                           size_t count, loff_t *ppos)
 127 {
 128         struct ipath_devdata *dd;
 129         ssize_t ret;
 130         loff_t pos;
 131         char *tmp;
 132
 133         pos = *ppos;
 134
 135         if ( pos < 0) {
 136                 ret = -EINVAL;
 137                 goto bail;
 138         }
 139
 140         if (pos >= sizeof(struct ipath_flash)) {
 141                 ret = 0;
 142                 goto bail;
 143         }
 144
 145         if (count > sizeof(struct ipath_flash) - pos)
 146                 count = sizeof(struct ipath_flash) - pos;
 147
 148         tmp = kmalloc(count, GFP_KERNEL);
 149         if (!tmp) {
 150                 ret = -ENOMEM;
 151                 goto bail;
 152         }
 153
 154         dd = file->f_path.dentry->d_inode->i_private;
 155         if (ipath_eeprom_read(dd, pos, tmp, count)) {
 156                 ipath_dev_err(dd, "failed to read from flash\n");
 157                 ret = -ENXIO;
 158                 goto bail_tmp;
 159         }
 160
 161         if (copy_to_user(buf, tmp, count)) {
 162                 ret = -EFAULT;
 163                 goto bail_tmp;
 164         }
 165
 166         *ppos = pos + count;
 167         ret = count;
 168
 169 bail_tmp:
 170         kfree(tmp);
 171
 172 bail:
 173         return ret;
 174 }
 175
 176 static ssize_t flash_write(struct file *file, const char __user *buf,
 177                            size_t count, loff_t *ppos)
 178 {
 179         struct ipath_devdata *dd;
 180         ssize_t ret;
 181         loff_t pos;
 182         char *tmp;
 183
 184         pos = *ppos;
 185
 186         if (pos != 0) {
 187                 ret = -EINVAL;
 188                 goto bail;
 189         }
 190
 191         if (count != sizeof(struct ipath_flash)) {
 192                 ret = -EINVAL;
 193                 goto bail;
 194         }
 195
 196         tmp = kmalloc(count, GFP_KERNEL);
 197         if (!tmp) {
 198                 ret = -ENOMEM;
 199                 goto bail;
 200         }
 201
 202         if (copy_from_user(tmp, buf, count)) {
 203                 ret = -EFAULT;
 204                 goto bail_tmp;
 205         }
 206
 207         dd = file->f_path.dentry->d_inode->i_private;
 208         if (ipath_eeprom_write(dd, pos, tmp, count)) {
 209                 ret = -ENXIO;
 210                 ipath_dev_err(dd, "failed to write to flash\n");
 211                 goto bail_tmp;
 212         }
 213
 214         *ppos = pos + count;
 215         ret = count;
 216
 217 bail_tmp:
 218         kfree(tmp);
 219
 220 bail:
 221         return ret;
 222 }
 223
 224 static const struct file_operations flash_ops = {
 225         .read = flash_read,
 226         .write = flash_write,
 227 };
 228
 229 static int create_device_files(struct super_block *sb,
 230                                struct ipath_devdata *dd)
 231 {
 232         struct dentry *dir, *tmp;
 233         char unit[10];
 234         int ret;
 235
 236         snprintf(unit, sizeof unit, "%02d", dd->ipath_unit);
 237         ret = create_file(unit, S_IFDIR|S_IRUGO|S_IXUGO, sb->s_root, &dir,
 238                           &simple_dir_operations, dd);
 239         if (ret) {
 240                 printk(KERN_ERR "create_file(%s) failed: %d\n", unit, ret);
 241                 goto bail;
 242         }
 243
 244         ret = create_file("atomic_counters", S_IFREG|S_IRUGO, dir, &tmp,
 245                           &atomic_counters_ops, dd);
 246         if (ret) {
 247                 printk(KERN_ERR "create_file(%s/atomic_counters) "
 248                        "failed: %d\n", unit, ret);
 249                 goto bail;
 250         }
 251
 252         ret = create_file("flash", S_IFREG|S_IWUSR|S_IRUGO, dir, &tmp,
 253                           &flash_ops, dd);
 254         if (ret) {
 255                 printk(KERN_ERR "create_file(%s/flash) "
 256                        "failed: %d\n", unit, ret);
 257                 goto bail;
 258         }
 259
 260 bail:
 261         return ret;
 262 }
 263
 264 static int remove_file(struct dentry *parent, char *name)
 265 {
 266         struct dentry *tmp;
 267         int ret;
 268
 269         tmp = lookup_one_len(name, parent, strlen(name));
 270
 271         if (IS_ERR(tmp)) {
 272                 ret = PTR_ERR(tmp);
 273                 goto bail;
 274         }
 275
 276         spin_lock(&dcache_lock);
 277         spin_lock(&tmp->d_lock);
 278         if (!(d_unhashed(tmp) && tmp->d_inode)) {
 279                 dget_locked(tmp);
 280                 __d_drop(tmp);
 281                 spin_unlock(&tmp->d_lock);
 282                 spin_unlock(&dcache_lock);
 283                 simple_unlink(parent->d_inode, tmp);
 284         } else {
 285                 spin_unlock(&tmp->d_lock);
 286                 spin_unlock(&dcache_lock);
 287         }
 288
 289         ret = 0;
 290 bail:
 291         /*
 292          * We don't expect clients to care about the return value, but
 293          * it's there if they need it.
 294          */
 295         return ret;
 296 }
 297
 298 static int remove_device_files(struct super_block *sb,
 299                                struct ipath_devdata *dd)
 300 {
 301         struct dentry *dir, *root;
 302         char unit[10];
 303         int ret;
 304
 305         root = dget(sb->s_root);
 306         mutex_lock(&root->d_inode->i_mutex);
 307         snprintf(unit, sizeof unit, "%02d", dd->ipath_unit);
 308         dir = lookup_one_len(unit, root, strlen(unit));
 309
 310         if (IS_ERR(dir)) {
 311                 ret = PTR_ERR(dir);
 312                 printk(KERN_ERR "Lookup of %s failed\n", unit);
 313                 goto bail;
 314         }
 315
 316         remove_file(dir, "flash");
 317         remove_file(dir, "atomic_counters");
 318         d_delete(dir);
 319         ret = simple_rmdir(root->d_inode, dir);
 320
 321 bail:
 322         mutex_unlock(&root->d_inode->i_mutex);
 323         dput(root);
 324         return ret;
 325 }
 326
 327 static int ipathfs_fill_super(struct super_block *sb, void *data,
 328                               int silent)
 329 {
 330         struct ipath_devdata *dd, *tmp;
 331         unsigned long flags;
 332         int ret;
 333
 334         static struct tree_descr files[] = {
 335                 [2] = {"atomic_stats", &atomic_stats_ops, S_IRUGO},
 336                 {""},
 337         };
 338
 339         ret = simple_fill_super(sb, IPATHFS_MAGIC, files);
 340         if (ret) {
 341                 printk(KERN_ERR "simple_fill_super failed: %d\n", ret);
 342                 goto bail;
 343         }
 344
 345         spin_lock_irqsave(&ipath_devs_lock, flags);
 346
 347         list_for_each_entry_safe(dd, tmp, &ipath_dev_list, ipath_list) {
 348                 spin_unlock_irqrestore(&ipath_devs_lock, flags);
 349                 ret = create_device_files(sb, dd);
 350                 if (ret)
 351                         goto bail;
 352                 spin_lock_irqsave(&ipath_devs_lock, flags);
 353         }
 354
 355         spin_unlock_irqrestore(&ipath_devs_lock, flags);
 356
 357 bail:
 358         return ret;
 359 }
 360
 361 static int ipathfs_get_sb(struct file_system_type *fs_type, int flags,
 362                         const char *dev_name, void *data, struct vfsmount *mnt)
 363 {
 364         int ret = get_sb_single(fs_type, flags, data,
 365                                     ipathfs_fill_super, mnt);
 366         if (ret >= 0)
 367                 ipath_super = mnt->mnt_sb;
 368         return ret;
 369 }
 370
 371 static void ipathfs_kill_super(struct super_block *s)
 372 {
 373         kill_litter_super(s);
 374         ipath_super = NULL;
 375 }
 376
 377 int ipathfs_add_device(struct ipath_devdata *dd)
 378 {
 379         int ret;
 380
 381         if (ipath_super == NULL) {
 382                 ret = 0;
 383                 goto bail;
 384         }
 385
 386         ret = create_device_files(ipath_super, dd);
 387
 388 bail:
 389         return ret;
 390 }
 391
 392 int ipathfs_remove_device(struct ipath_devdata *dd)
 393 {
 394         int ret;
 395
 396         if (ipath_super == NULL) {
 397                 ret = 0;
 398                 goto bail;
 399         }
 400
 401         ret = remove_device_files(ipath_super, dd);
 402
 403 bail:
 404         return ret;
 405 }
 406
 407 static struct file_system_type ipathfs_fs_type = {
 408         .owner =        THIS_MODULE,
 409         .name =         "ipathfs",
 410         .get_sb =       ipathfs_get_sb,
 411         .kill_sb =      ipathfs_kill_super,
 412 };
 413
 414 int __init ipath_init_ipathfs(void)
 415 {
 416         return register_filesystem(&ipathfs_fs_type);
 417 }
 418
 419 void __exit ipath_exit_ipathfs(void)
 420 {
 421         unregister_filesystem(&ipathfs_fs_type);
 422 }