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
  41 #include "ipath_kernel.h"
  42
  43 #define IPATHFS_MAGIC 0x726a77
  44
  45 static struct super_block *ipath_super;
  46
  47 static int ipathfs_mknod(struct inode *dir, struct dentry *dentry,
  48                          int mode, const struct file_operations *fops,
  49                          void *data)
  50 {
  51         int error;
  52         struct inode *inode = new_inode(dir->i_sb);
  53
  54         if (!inode) {
  55                 error = -EPERM;
  56                 goto bail;
  57         }
  58
  59         inode->i_mode = mode;
  60         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
  61         inode->i_private = data;
  62         if ((mode & S_IFMT) == S_IFDIR) {
  63                 inode->i_op = &simple_dir_inode_operations;
  64                 inc_nlink(inode);
  65                 inc_nlink(dir);
  66         }
  67
  68         inode->i_fop = fops;
  69
  70         d_instantiate(dentry, inode);
  71         error = 0;
  72
  73 bail:
  74         return error;
  75 }
  76
  77 static int create_file(const char *name, mode_t mode,
  78                        struct dentry *parent, struct dentry **dentry,
  79                        const struct file_operations *fops, void *data)
  80 {
  81         int error;
  82
  83         *dentry = NULL;
  84         mutex_lock(&parent->d_inode->i_mutex);
  85         *dentry = lookup_one_len(name, parent, strlen(name));
  86         if (!IS_ERR(*dentry))
  87                 error = ipathfs_mknod(parent->d_inode, *dentry,
  88                                       mode, fops, data);
  89         else
  90                 error = PTR_ERR(dentry);
  91         mutex_unlock(&parent->d_inode->i_mutex);
  92
  93         return error;
  94 }
  95
  96 static ssize_t atomic_stats_read(struct file *file, char __user *buf,
  97                                  size_t count, loff_t *ppos)
  98 {
  99         return simple_read_from_buffer(buf, count, ppos, &ipath_stats,
 100                                        sizeof ipath_stats);
 101 }
 102
 103 static const struct file_operations atomic_stats_ops = {
 104         .read = atomic_stats_read,
 105 };
 106
 107 static ssize_t atomic_counters_read(struct file *file, char __user *buf,
 108                                     size_t count, loff_t *ppos)
 109 {
 110         struct infinipath_counters counters;
 111         struct ipath_devdata *dd;
 112
 113         dd = file->f_path.dentry->d_inode->i_private;
 114         dd->ipath_f_read_counters(dd, &counters);
 115
 116         return simple_read_from_buffer(buf, count, ppos, &counters,
 117                                        sizeof counters);
 118 }
 119
 120 static const struct file_operations atomic_counters_ops = {
 121         .read = atomic_counters_read,
 122 };
 123
 124 static ssize_t flash_read(struct file *file, char __user *buf,
 125                           size_t count, loff_t *ppos)
 126 {
 127         struct ipath_devdata *dd;
 128         ssize_t ret;
 129         loff_t pos;
 130         char *tmp;
 131
 132         pos = *ppos;
 133
 134         if ( pos < 0) {
 135                 ret = -EINVAL;
 136                 goto bail;
 137         }
 138
 139         if (pos >= sizeof(struct ipath_flash)) {
 140                 ret = 0;
 141                 goto bail;
 142         }
 143
 144         if (count > sizeof(struct ipath_flash) - pos)
 145                 count = sizeof(struct ipath_flash) - pos;
 146
 147         tmp = kmalloc(count, GFP_KERNEL);
 148         if (!tmp) {
 149                 ret = -ENOMEM;
 150                 goto bail;
 151         }
 152
 153         dd = file->f_path.dentry->d_inode->i_private;
 154         if (ipath_eeprom_read(dd, pos, tmp, count)) {
 155                 ipath_dev_err(dd, "failed to read from flash\n");
 156                 ret = -ENXIO;
 157                 goto bail_tmp;
 158         }
 159
 160         if (copy_to_user(buf, tmp, count)) {
 161                 ret = -EFAULT;
 162                 goto bail_tmp;
 163         }
 164
 165         *ppos = pos + count;
 166         ret = count;
 167
 168 bail_tmp:
 169         kfree(tmp);
 170
 171 bail:
 172         return ret;
 173 }
 174
 175 static ssize_t flash_write(struct file *file, const char __user *buf,
 176                            size_t count, loff_t *ppos)
 177 {
 178         struct ipath_devdata *dd;
 179         ssize_t ret;
 180         loff_t pos;
 181         char *tmp;
 182
 183         pos = *ppos;
 184
 185         if (pos != 0) {
 186                 ret = -EINVAL;
 187                 goto bail;
 188         }
 189
 190         if (count != sizeof(struct ipath_flash)) {
 191                 ret = -EINVAL;
 192                 goto bail;
 193         }
 194
 195         tmp = kmalloc(count, GFP_KERNEL);
 196         if (!tmp) {
 197                 ret = -ENOMEM;
 198                 goto bail;
 199         }
 200
 201         if (copy_from_user(tmp, buf, count)) {
 202                 ret = -EFAULT;
 203                 goto bail_tmp;
 204         }
 205
 206         dd = file->f_path.dentry->d_inode->i_private;
 207         if (ipath_eeprom_write(dd, pos, tmp, count)) {
 208                 ret = -ENXIO;
 209                 ipath_dev_err(dd, "failed to write to flash\n");
 210                 goto bail_tmp;
 211         }
 212
 213         *ppos = pos + count;
 214         ret = count;
 215
 216 bail_tmp:
 217         kfree(tmp);
 218
 219 bail:
 220         return ret;
 221 }
 222
 223 static const struct file_operations flash_ops = {
 224         .read = flash_read,
 225         .write = flash_write,
 226 };
 227
 228 static int create_device_files(struct super_block *sb,
 229                                struct ipath_devdata *dd)
 230 {
 231         struct dentry *dir, *tmp;
 232         char unit[10];
 233         int ret;
 234
 235         snprintf(unit, sizeof unit, "%02d", dd->ipath_unit);
 236         ret = create_file(unit, S_IFDIR|S_IRUGO|S_IXUGO, sb->s_root, &dir,
 237                           &simple_dir_operations, dd);
 238         if (ret) {
 239                 printk(KERN_ERR "create_file(%s) failed: %d\n", unit, ret);
 240                 goto bail;
 241         }
 242
 243         ret = create_file("atomic_counters", S_IFREG|S_IRUGO, dir, &tmp,
 244                           &atomic_counters_ops, dd);
 245         if (ret) {
 246                 printk(KERN_ERR "create_file(%s/atomic_counters) "
 247                        "failed: %d\n", unit, ret);
 248                 goto bail;
 249         }
 250
 251         ret = create_file("flash", S_IFREG|S_IWUSR|S_IRUGO, dir, &tmp,
 252                           &flash_ops, dd);
 253         if (ret) {
 254                 printk(KERN_ERR "create_file(%s/flash) "
 255                        "failed: %d\n", unit, ret);
 256                 goto bail;
 257         }
 258
 259 bail:
 260         return ret;
 261 }
 262
 263 static int remove_file(struct dentry *parent, char *name)
 264 {
 265         struct dentry *tmp;
 266         int ret;
 267
 268         tmp = lookup_one_len(name, parent, strlen(name));
 269
 270         if (IS_ERR(tmp)) {
 271                 ret = PTR_ERR(tmp);
 272                 goto bail;
 273         }
 274
 275         spin_lock(&dcache_lock);
 276         spin_lock(&tmp->d_lock);
 277         if (!(d_unhashed(tmp) && tmp->d_inode)) {
 278                 dget_locked(tmp);
 279                 __d_drop(tmp);
 280                 spin_unlock(&tmp->d_lock);
 281                 spin_unlock(&dcache_lock);
 282                 simple_unlink(parent->d_inode, tmp);
 283         } else {
 284                 spin_unlock(&tmp->d_lock);
 285                 spin_unlock(&dcache_lock);
 286         }
 287
 288         ret = 0;
 289 bail:
 290         /*
 291          * We don't expect clients to care about the return value, but
 292          * it's there if they need it.
 293          */
 294         return ret;
 295 }
 296
 297 static int remove_device_files(struct super_block *sb,
 298                                struct ipath_devdata *dd)
 299 {
 300         struct dentry *dir, *root;
 301         char unit[10];
 302         int ret;
 303
 304         root = dget(sb->s_root);
 305         mutex_lock(&root->d_inode->i_mutex);
 306         snprintf(unit, sizeof unit, "%02d", dd->ipath_unit);
 307         dir = lookup_one_len(unit, root, strlen(unit));
 308
 309         if (IS_ERR(dir)) {
 310                 ret = PTR_ERR(dir);
 311                 printk(KERN_ERR "Lookup of %s failed\n", unit);
 312                 goto bail;
 313         }
 314
 315         remove_file(dir, "flash");
 316         remove_file(dir, "atomic_counters");
 317         d_delete(dir);
 318         ret = simple_rmdir(root->d_inode, dir);
 319
 320 bail:
 321         mutex_unlock(&root->d_inode->i_mutex);
 322         dput(root);
 323         return ret;
 324 }
 325
 326 static int ipathfs_fill_super(struct super_block *sb, void *data,
 327                               int silent)
 328 {
 329         struct ipath_devdata *dd, *tmp;
 330         unsigned long flags;
 331         int ret;
 332
 333         static struct tree_descr files[] = {
 334                 [2] = {"atomic_stats", &atomic_stats_ops, S_IRUGO},
 335                 {""},
 336         };
 337
 338         ret = simple_fill_super(sb, IPATHFS_MAGIC, files);
 339         if (ret) {
 340                 printk(KERN_ERR "simple_fill_super failed: %d\n", ret);
 341                 goto bail;
 342         }
 343
 344         spin_lock_irqsave(&ipath_devs_lock, flags);
 345
 346         list_for_each_entry_safe(dd, tmp, &ipath_dev_list, ipath_list) {
 347                 spin_unlock_irqrestore(&ipath_devs_lock, flags);
 348                 ret = create_device_files(sb, dd);
 349                 if (ret) {
 350                         deactivate_locked_super(sb);
 351                         goto bail;
 352                 }
 353                 spin_lock_irqsave(&ipath_devs_lock, flags);
 354         }
 355
 356         spin_unlock_irqrestore(&ipath_devs_lock, flags);
 357
 358 bail:
 359         return ret;
 360 }
 361
 362 static int ipathfs_get_sb(struct file_system_type *fs_type, int flags,
 363                         const char *dev_name, void *data, struct vfsmount *mnt)
 364 {
 365         int ret = get_sb_single(fs_type, flags, data,
 366                                     ipathfs_fill_super, mnt);
 367         if (ret >= 0)
 368                 ipath_super = mnt->mnt_sb;
 369         return ret;
 370 }
 371
 372 static void ipathfs_kill_super(struct super_block *s)
 373 {
 374         kill_litter_super(s);
 375         ipath_super = NULL;
 376 }
 377
 378 int ipathfs_add_device(struct ipath_devdata *dd)
 379 {
 380         int ret;
 381
 382         if (ipath_super == NULL) {
 383                 ret = 0;
 384                 goto bail;
 385         }
 386
 387         ret = create_device_files(ipath_super, dd);
 388
 389 bail:
 390         return ret;
 391 }
 392
 393 int ipathfs_remove_device(struct ipath_devdata *dd)
 394 {
 395         int ret;
 396
 397         if (ipath_super == NULL) {
 398                 ret = 0;
 399                 goto bail;
 400         }
 401
 402         ret = remove_device_files(ipath_super, dd);
 403
 404 bail:
 405         return ret;
 406 }
 407
 408 static struct file_system_type ipathfs_fs_type = {
 409         .owner =        THIS_MODULE,
 410         .name =         "ipathfs",
 411         .get_sb =       ipathfs_get_sb,
 412         .kill_sb =      ipathfs_kill_super,
 413 };
 414
 415 int __init ipath_init_ipathfs(void)
 416 {
 417         return register_filesystem(&ipathfs_fs_type);
 418 }
 419
 420 void __exit ipath_exit_ipathfs(void)
 421 {
 422         unregister_filesystem(&ipathfs_fs_type);
 423 }