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