kernel/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         mutex_lock(&d_inode(parent)->i_mutex);
  86         *dentry = lookup_one_len(name, parent, strlen(name));
  87         if (!IS_ERR(*dentry))
  88                 error = ipathfs_mknod(d_inode(parent), *dentry,
  89                                       mode, fops, data);
  90         else
  91                 error = PTR_ERR(*dentry);
  92         mutex_unlock(&d_inode(parent)->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         .llseek = default_llseek,
 107 };
 108
 109 static ssize_t atomic_counters_read(struct file *file, char __user *buf,
 110                                     size_t count, loff_t *ppos)
 111 {
 112         struct infinipath_counters counters;
 113         struct ipath_devdata *dd;
 114
 115         dd = file_inode(file)->i_private;
 116         dd->ipath_f_read_counters(dd, &counters);
 117
 118         return simple_read_from_buffer(buf, count, ppos, &counters,
 119                                        sizeof counters);
 120 }
 121
 122 static const struct file_operations atomic_counters_ops = {
 123         .read = atomic_counters_read,
 124         .llseek = default_llseek,
 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_inode(file)->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_inode(file)->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         .llseek = default_llseek,
 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(&tmp->d_lock);
 280         if (!d_unhashed(tmp) && d_really_is_positive(tmp)) {
 281                 dget_dlock(tmp);
 282                 __d_drop(tmp);
 283                 spin_unlock(&tmp->d_lock);
 284                 simple_unlink(d_inode(parent), tmp);
 285         } else
 286                 spin_unlock(&tmp->d_lock);
 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(&d_inode(root)->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(d_inode(root), dir);
 319
 320 bail:
 321         mutex_unlock(&d_inode(root)->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                         goto bail;
 351                 spin_lock_irqsave(&ipath_devs_lock, flags);
 352         }
 353
 354         spin_unlock_irqrestore(&ipath_devs_lock, flags);
 355
 356 bail:
 357         return ret;
 358 }
 359
 360 static struct dentry *ipathfs_mount(struct file_system_type *fs_type,
 361                         int flags, const char *dev_name, void *data)
 362 {
 363         struct dentry *ret;
 364         ret = mount_single(fs_type, flags, data, ipathfs_fill_super);
 365         if (!IS_ERR(ret))
 366                 ipath_super = ret->d_sb;
 367         return ret;
 368 }
 369
 370 static void ipathfs_kill_super(struct super_block *s)
 371 {
 372         kill_litter_super(s);
 373         ipath_super = NULL;
 374 }
 375
 376 int ipathfs_add_device(struct ipath_devdata *dd)
 377 {
 378         int ret;
 379
 380         if (ipath_super == NULL) {
 381                 ret = 0;
 382                 goto bail;
 383         }
 384
 385         ret = create_device_files(ipath_super, dd);
 386
 387 bail:
 388         return ret;
 389 }
 390
 391 int ipathfs_remove_device(struct ipath_devdata *dd)
 392 {
 393         int ret;
 394
 395         if (ipath_super == NULL) {
 396                 ret = 0;
 397                 goto bail;
 398         }
 399
 400         ret = remove_device_files(ipath_super, dd);
 401
 402 bail:
 403         return ret;
 404 }
 405
 406 static struct file_system_type ipathfs_fs_type = {
 407         .owner =        THIS_MODULE,
 408         .name =         "ipathfs",
 409         .mount =        ipathfs_mount,
 410         .kill_sb =      ipathfs_kill_super,
 411 };
 412 MODULE_ALIAS_FS("ipathfs");
 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 }