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/version.h>
  35 #include <linux/module.h>
  36 #include <linux/fs.h>
  37 #include <linux/mount.h>
  38 #include <linux/pagemap.h>
  39 #include <linux/init.h>
  40 #include <linux/namei.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_uid = 0;
  62         inode->i_gid = 0;
  63         inode->i_blocks = 0;
  64         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
  65         inode->i_private = data;
  66         if ((mode & S_IFMT) == S_IFDIR) {
  67                 inode->i_op = &simple_dir_inode_operations;
  68                 inc_nlink(inode);
  69                 inc_nlink(dir);
  70         }
  71
  72         inode->i_fop = fops;
  73
  74         d_instantiate(dentry, inode);
  75         error = 0;
  76
  77 bail:
  78         return error;
  79 }
  80
  81 static int create_file(const char *name, mode_t mode,
  82                        struct dentry *parent, struct dentry **dentry,
  83                        const struct file_operations *fops, void *data)
  84 {
  85         int error;
  86
  87         *dentry = NULL;
  88         mutex_lock(&parent->d_inode->i_mutex);
  89         *dentry = lookup_one_len(name, parent, strlen(name));
  90         if (!IS_ERR(dentry))
  91                 error = ipathfs_mknod(parent->d_inode, *dentry,
  92                                       mode, fops, data);
  93         else
  94                 error = PTR_ERR(dentry);
  95         mutex_unlock(&parent->d_inode->i_mutex);
  96
  97         return error;
  98 }
  99
 100 static ssize_t atomic_stats_read(struct file *file, char __user *buf,
 101                                  size_t count, loff_t *ppos)
 102 {
 103         return simple_read_from_buffer(buf, count, ppos, &ipath_stats,
 104                                        sizeof ipath_stats);
 105 }
 106
 107 static const struct file_operations atomic_stats_ops = {
 108         .read = atomic_stats_read,
 109 };
 110
 111 static ssize_t atomic_counters_read(struct file *file, char __user *buf,
 112                                     size_t count, loff_t *ppos)
 113 {
 114         struct infinipath_counters counters;
 115         struct ipath_devdata *dd;
 116
 117         dd = file->f_path.dentry->d_inode->i_private;
 118         dd->ipath_f_read_counters(dd, &counters);
 119
 120         return simple_read_from_buffer(buf, count, ppos, &counters,
 121                                        sizeof counters);
 122 }
 123
 124 static const struct file_operations atomic_counters_ops = {
 125         .read = atomic_counters_read,
 126 };
 127
 128 static ssize_t flash_read(struct file *file, char __user *buf,
 129                           size_t count, loff_t *ppos)
 130 {
 131         struct ipath_devdata *dd;
 132         ssize_t ret;
 133         loff_t pos;
 134         char *tmp;
 135
 136         pos = *ppos;
 137
 138         if ( pos < 0) {
 139                 ret = -EINVAL;
 140                 goto bail;
 141         }
 142
 143         if (pos >= sizeof(struct ipath_flash)) {
 144                 ret = 0;
 145                 goto bail;
 146         }
 147
 148         if (count > sizeof(struct ipath_flash) - pos)
 149                 count = sizeof(struct ipath_flash) - pos;
 150
 151         tmp = kmalloc(count, GFP_KERNEL);
 152         if (!tmp) {
 153                 ret = -ENOMEM;
 154                 goto bail;
 155         }
 156
 157         dd = file->f_path.dentry->d_inode->i_private;
 158         if (ipath_eeprom_read(dd, pos, tmp, count)) {
 159                 ipath_dev_err(dd, "failed to read from flash\n");
 160                 ret = -ENXIO;
 161                 goto bail_tmp;
 162         }
 163
 164         if (copy_to_user(buf, tmp, count)) {
 165                 ret = -EFAULT;
 166                 goto bail_tmp;
 167         }
 168
 169         *ppos = pos + count;
 170         ret = count;
 171
 172 bail_tmp:
 173         kfree(tmp);
 174
 175 bail:
 176         return ret;
 177 }
 178
 179 static ssize_t flash_write(struct file *file, const char __user *buf,
 180                            size_t count, loff_t *ppos)
 181 {
 182         struct ipath_devdata *dd;
 183         ssize_t ret;
 184         loff_t pos;
 185         char *tmp;
 186
 187         pos = *ppos;
 188
 189         if (pos != 0) {
 190                 ret = -EINVAL;
 191                 goto bail;
 192         }
 193
 194         if (count != sizeof(struct ipath_flash)) {
 195                 ret = -EINVAL;
 196                 goto bail;
 197         }
 198
 199         tmp = kmalloc(count, GFP_KERNEL);
 200         if (!tmp) {
 201                 ret = -ENOMEM;
 202                 goto bail;
 203         }
 204
 205         if (copy_from_user(tmp, buf, count)) {
 206                 ret = -EFAULT;
 207                 goto bail_tmp;
 208         }
 209
 210         dd = file->f_path.dentry->d_inode->i_private;
 211         if (ipath_eeprom_write(dd, pos, tmp, count)) {
 212                 ret = -ENXIO;
 213                 ipath_dev_err(dd, "failed to write to flash\n");
 214                 goto bail_tmp;
 215         }
 216
 217         *ppos = pos + count;
 218         ret = count;
 219
 220 bail_tmp:
 221         kfree(tmp);
 222
 223 bail:
 224         return ret;
 225 }
 226
 227 static const struct file_operations flash_ops = {
 228         .read = flash_read,
 229         .write = flash_write,
 230 };
 231
 232 static int create_device_files(struct super_block *sb,
 233                                struct ipath_devdata *dd)
 234 {
 235         struct dentry *dir, *tmp;
 236         char unit[10];
 237         int ret;
 238
 239         snprintf(unit, sizeof unit, "%02d", dd->ipath_unit);
 240         ret = create_file(unit, S_IFDIR|S_IRUGO|S_IXUGO, sb->s_root, &dir,
 241                           &simple_dir_operations, dd);
 242         if (ret) {
 243                 printk(KERN_ERR "create_file(%s) failed: %d\n", unit, ret);
 244                 goto bail;
 245         }
 246
 247         ret = create_file("atomic_counters", S_IFREG|S_IRUGO, dir, &tmp,
 248                           &atomic_counters_ops, dd);
 249         if (ret) {
 250                 printk(KERN_ERR "create_file(%s/atomic_counters) "
 251                        "failed: %d\n", unit, ret);
 252                 goto bail;
 253         }
 254
 255         ret = create_file("flash", S_IFREG|S_IWUSR|S_IRUGO, dir, &tmp,
 256                           &flash_ops, dd);
 257         if (ret) {
 258                 printk(KERN_ERR "create_file(%s/flash) "
 259                        "failed: %d\n", unit, ret);
 260                 goto bail;
 261         }
 262
 263 bail:
 264         return ret;
 265 }
 266
 267 static int remove_file(struct dentry *parent, char *name)
 268 {
 269         struct dentry *tmp;
 270         int ret;
 271
 272         tmp = lookup_one_len(name, parent, strlen(name));
 273
 274         if (IS_ERR(tmp)) {
 275                 ret = PTR_ERR(tmp);
 276                 goto bail;
 277         }
 278
 279         spin_lock(&dcache_lock);
 280         spin_lock(&tmp->d_lock);
 281         if (!(d_unhashed(tmp) && tmp->d_inode)) {
 282                 dget_locked(tmp);
 283                 __d_drop(tmp);
 284                 spin_unlock(&tmp->d_lock);
 285                 spin_unlock(&dcache_lock);
 286                 simple_unlink(parent->d_inode, tmp);
 287         } else {
 288                 spin_unlock(&tmp->d_lock);
 289                 spin_unlock(&dcache_lock);
 290         }
 291
 292         ret = 0;
 293 bail:
 294         /*
 295          * We don't expect clients to care about the return value, but
 296          * it's there if they need it.
 297          */
 298         return ret;
 299 }
 300
 301 static int remove_device_files(struct super_block *sb,
 302                                struct ipath_devdata *dd)
 303 {
 304         struct dentry *dir, *root;
 305         char unit[10];
 306         int ret;
 307
 308         root = dget(sb->s_root);
 309         mutex_lock(&root->d_inode->i_mutex);
 310         snprintf(unit, sizeof unit, "%02d", dd->ipath_unit);
 311         dir = lookup_one_len(unit, root, strlen(unit));
 312
 313         if (IS_ERR(dir)) {
 314                 ret = PTR_ERR(dir);
 315                 printk(KERN_ERR "Lookup of %s failed\n", unit);
 316                 goto bail;
 317         }
 318
 319         remove_file(dir, "flash");
 320         remove_file(dir, "atomic_counters");
 321         d_delete(dir);
 322         ret = simple_rmdir(root->d_inode, dir);
 323
 324 bail:
 325         mutex_unlock(&root->d_inode->i_mutex);
 326         dput(root);
 327         return ret;
 328 }
 329
 330 static int ipathfs_fill_super(struct super_block *sb, void *data,
 331                               int silent)
 332 {
 333         struct ipath_devdata *dd, *tmp;
 334         unsigned long flags;
 335         int ret;
 336
 337         static struct tree_descr files[] = {
 338                 [2] = {"atomic_stats", &atomic_stats_ops, S_IRUGO},
 339                 {""},
 340         };
 341
 342         ret = simple_fill_super(sb, IPATHFS_MAGIC, files);
 343         if (ret) {
 344                 printk(KERN_ERR "simple_fill_super failed: %d\n", ret);
 345                 goto bail;
 346         }
 347
 348         spin_lock_irqsave(&ipath_devs_lock, flags);
 349
 350         list_for_each_entry_safe(dd, tmp, &ipath_dev_list, ipath_list) {
 351                 spin_unlock_irqrestore(&ipath_devs_lock, flags);
 352                 ret = create_device_files(sb, dd);
 353                 if (ret) {
 354                         deactivate_super(sb);
 355                         goto bail;
 356                 }
 357                 spin_lock_irqsave(&ipath_devs_lock, flags);
 358         }
 359
 360         spin_unlock_irqrestore(&ipath_devs_lock, flags);
 361
 362 bail:
 363         return ret;
 364 }
 365
 366 static int ipathfs_get_sb(struct file_system_type *fs_type, int flags,
 367                         const char *dev_name, void *data, struct vfsmount *mnt)
 368 {
 369         int ret = get_sb_single(fs_type, flags, data,
 370                                     ipathfs_fill_super, mnt);
 371         if (ret >= 0)
 372                 ipath_super = mnt->mnt_sb;
 373         return ret;
 374 }
 375
 376 static void ipathfs_kill_super(struct super_block *s)
 377 {
 378         kill_litter_super(s);
 379         ipath_super = NULL;
 380 }
 381
 382 int ipathfs_add_device(struct ipath_devdata *dd)
 383 {
 384         int ret;
 385
 386         if (ipath_super == NULL) {
 387                 ret = 0;
 388                 goto bail;
 389         }
 390
 391         ret = create_device_files(ipath_super, dd);
 392
 393 bail:
 394         return ret;
 395 }
 396
 397 int ipathfs_remove_device(struct ipath_devdata *dd)
 398 {
 399         int ret;
 400
 401         if (ipath_super == NULL) {
 402                 ret = 0;
 403                 goto bail;
 404         }
 405
 406         ret = remove_device_files(ipath_super, dd);
 407
 408 bail:
 409         return ret;
 410 }
 411
 412 static struct file_system_type ipathfs_fs_type = {
 413         .owner =        THIS_MODULE,
 414         .name =         "ipathfs",
 415         .get_sb =       ipathfs_get_sb,
 416         .kill_sb =      ipathfs_kill_super,
 417 };
 418
 419 int __init ipath_init_ipathfs(void)
 420 {
 421         return register_filesystem(&ipathfs_fs_type);
 422 }
 423
 424 void __exit ipath_exit_ipathfs(void)
 425 {
 426         unregister_filesystem(&ipathfs_fs_type);
 427 }