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                          umode_t 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_ino = get_next_ino();
  61         inode->i_mode = mode;
  62         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
  63         inode->i_private = data;
  64         if (S_ISDIR(mode)) {
  65                 inode->i_op = &simple_dir_inode_operations;
  66                 inc_nlink(inode);
  67                 inc_nlink(dir);
  68         }
  69
  70         inode->i_fop = fops;
  71
  72         d_instantiate(dentry, inode);
  73         error = 0;
  74
  75 bail:
  76         return error;
  77 }
  78
  79 static int create_file(const char *name, umode_t mode,
  80                        struct dentry *parent, struct dentry **dentry,
  81                        const struct file_operations *fops, void *data)
  82 {
  83         int error;
  84
  85         *dentry = NULL;
  86         mutex_lock(&parent->d_inode->i_mutex);
  87         *dentry = lookup_one_len(name, parent, strlen(name));
  88         if (!IS_ERR(*dentry))
  89                 error = ipathfs_mknod(parent->d_inode, *dentry,
  90                                       mode, fops, data);
  91         else
  92                 error = PTR_ERR(*dentry);
  93         mutex_unlock(&parent->d_inode->i_mutex);
  94
  95         return error;
  96 }
  97
  98 static ssize_t atomic_stats_read(struct file *file, char __user *buf,
  99                                  size_t count, loff_t *ppos)
 100 {
 101         return simple_read_from_buffer(buf, count, ppos, &ipath_stats,
 102                                        sizeof ipath_stats);
 103 }
 104
 105 static const struct file_operations atomic_stats_ops = {
 106         .read = atomic_stats_read,
 107         .llseek = default_llseek,
 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         .llseek = default_llseek,
 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         .llseek = default_llseek,
 231 };
 232
 233 static int create_device_files(struct super_block *sb,
 234                                struct ipath_devdata *dd)
 235 {
 236         struct dentry *dir, *tmp;
 237         char unit[10];
 238         int ret;
 239
 240         snprintf(unit, sizeof unit, "%02d", dd->ipath_unit);
 241         ret = create_file(unit, S_IFDIR|S_IRUGO|S_IXUGO, sb->s_root, &dir,
 242                           &simple_dir_operations, dd);
 243         if (ret) {
 244                 printk(KERN_ERR "create_file(%s) failed: %d\n", unit, ret);
 245                 goto bail;
 246         }
 247
 248         ret = create_file("atomic_counters", S_IFREG|S_IRUGO, dir, &tmp,
 249                           &atomic_counters_ops, dd);
 250         if (ret) {
 251                 printk(KERN_ERR "create_file(%s/atomic_counters) "
 252                        "failed: %d\n", unit, ret);
 253                 goto bail;
 254         }
 255
 256         ret = create_file("flash", S_IFREG|S_IWUSR|S_IRUGO, dir, &tmp,
 257                           &flash_ops, dd);
 258         if (ret) {
 259                 printk(KERN_ERR "create_file(%s/flash) "
 260                        "failed: %d\n", unit, ret);
 261                 goto bail;
 262         }
 263
 264 bail:
 265         return ret;
 266 }
 267
 268 static int remove_file(struct dentry *parent, char *name)
 269 {
 270         struct dentry *tmp;
 271         int ret;
 272
 273         tmp = lookup_one_len(name, parent, strlen(name));
 274
 275         if (IS_ERR(tmp)) {
 276                 ret = PTR_ERR(tmp);
 277                 goto bail;
 278         }
 279
 280         spin_lock(&tmp->d_lock);
 281         if (!(d_unhashed(tmp) && tmp->d_inode)) {
 282                 dget_dlock(tmp);
 283                 __d_drop(tmp);
 284                 spin_unlock(&tmp->d_lock);
 285                 simple_unlink(parent->d_inode, tmp);
 286         } else
 287                 spin_unlock(&tmp->d_lock);
 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 struct dentry *ipathfs_mount(struct file_system_type *fs_type,
 362                         int flags, const char *dev_name, void *data)
 363 {
 364         struct dentry *ret;
 365         ret = mount_single(fs_type, flags, data, ipathfs_fill_super);
 366         if (!IS_ERR(ret))
 367                 ipath_super = ret->d_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         .mount =        ipathfs_mount,
 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 }