Merge commit 'v2.6.27-rc6' into x86/pat
[linux-2.6] / 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 }