Merge branch 'upstream-fixes' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik...
[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/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 #define NUM_COUNTERS sizeof(struct infinipath_counters) / sizeof(u64)
112
113 static ssize_t atomic_counters_read(struct file *file, char __user *buf,
114                                     size_t count, loff_t *ppos)
115 {
116         u64 counters[NUM_COUNTERS];
117         u16 i;
118         struct ipath_devdata *dd;
119
120         dd = file->f_path.dentry->d_inode->i_private;
121
122         for (i = 0; i < NUM_COUNTERS; i++)
123                 counters[i] = ipath_snap_cntr(dd, i);
124
125         return simple_read_from_buffer(buf, count, ppos, counters,
126                                        sizeof counters);
127 }
128
129 static const struct file_operations atomic_counters_ops = {
130         .read = atomic_counters_read,
131 };
132
133 static ssize_t flash_read(struct file *file, char __user *buf,
134                           size_t count, loff_t *ppos)
135 {
136         struct ipath_devdata *dd;
137         ssize_t ret;
138         loff_t pos;
139         char *tmp;
140
141         pos = *ppos;
142
143         if ( pos < 0) {
144                 ret = -EINVAL;
145                 goto bail;
146         }
147
148         if (pos >= sizeof(struct ipath_flash)) {
149                 ret = 0;
150                 goto bail;
151         }
152
153         if (count > sizeof(struct ipath_flash) - pos)
154                 count = sizeof(struct ipath_flash) - pos;
155
156         tmp = kmalloc(count, GFP_KERNEL);
157         if (!tmp) {
158                 ret = -ENOMEM;
159                 goto bail;
160         }
161
162         dd = file->f_path.dentry->d_inode->i_private;
163         if (ipath_eeprom_read(dd, pos, tmp, count)) {
164                 ipath_dev_err(dd, "failed to read from flash\n");
165                 ret = -ENXIO;
166                 goto bail_tmp;
167         }
168
169         if (copy_to_user(buf, tmp, count)) {
170                 ret = -EFAULT;
171                 goto bail_tmp;
172         }
173
174         *ppos = pos + count;
175         ret = count;
176
177 bail_tmp:
178         kfree(tmp);
179
180 bail:
181         return ret;
182 }
183
184 static ssize_t flash_write(struct file *file, const char __user *buf,
185                            size_t count, loff_t *ppos)
186 {
187         struct ipath_devdata *dd;
188         ssize_t ret;
189         loff_t pos;
190         char *tmp;
191
192         pos = *ppos;
193
194         if (pos != 0) {
195                 ret = -EINVAL;
196                 goto bail;
197         }
198
199         if (count != sizeof(struct ipath_flash)) {
200                 ret = -EINVAL;
201                 goto bail;
202         }
203
204         tmp = kmalloc(count, GFP_KERNEL);
205         if (!tmp) {
206                 ret = -ENOMEM;
207                 goto bail;
208         }
209
210         if (copy_from_user(tmp, buf, count)) {
211                 ret = -EFAULT;
212                 goto bail_tmp;
213         }
214
215         dd = file->f_path.dentry->d_inode->i_private;
216         if (ipath_eeprom_write(dd, pos, tmp, count)) {
217                 ret = -ENXIO;
218                 ipath_dev_err(dd, "failed to write to flash\n");
219                 goto bail_tmp;
220         }
221
222         *ppos = pos + count;
223         ret = count;
224
225 bail_tmp:
226         kfree(tmp);
227
228 bail:
229         return ret;
230 }
231
232 static const struct file_operations flash_ops = {
233         .read = flash_read,
234         .write = flash_write,
235 };
236
237 static int create_device_files(struct super_block *sb,
238                                struct ipath_devdata *dd)
239 {
240         struct dentry *dir, *tmp;
241         char unit[10];
242         int ret;
243
244         snprintf(unit, sizeof unit, "%02d", dd->ipath_unit);
245         ret = create_file(unit, S_IFDIR|S_IRUGO|S_IXUGO, sb->s_root, &dir,
246                           (struct file_operations *) &simple_dir_operations,
247                           dd);
248         if (ret) {
249                 printk(KERN_ERR "create_file(%s) failed: %d\n", unit, ret);
250                 goto bail;
251         }
252
253         ret = create_file("atomic_counters", S_IFREG|S_IRUGO, dir, &tmp,
254                           &atomic_counters_ops, dd);
255         if (ret) {
256                 printk(KERN_ERR "create_file(%s/atomic_counters) "
257                        "failed: %d\n", unit, ret);
258                 goto bail;
259         }
260
261         ret = create_file("flash", S_IFREG|S_IWUSR|S_IRUGO, dir, &tmp,
262                           &flash_ops, dd);
263         if (ret) {
264                 printk(KERN_ERR "create_file(%s/flash) "
265                        "failed: %d\n", unit, ret);
266                 goto bail;
267         }
268
269 bail:
270         return ret;
271 }
272
273 static int remove_file(struct dentry *parent, char *name)
274 {
275         struct dentry *tmp;
276         int ret;
277
278         tmp = lookup_one_len(name, parent, strlen(name));
279
280         if (IS_ERR(tmp)) {
281                 ret = PTR_ERR(tmp);
282                 goto bail;
283         }
284
285         spin_lock(&dcache_lock);
286         spin_lock(&tmp->d_lock);
287         if (!(d_unhashed(tmp) && tmp->d_inode)) {
288                 dget_locked(tmp);
289                 __d_drop(tmp);
290                 spin_unlock(&tmp->d_lock);
291                 spin_unlock(&dcache_lock);
292                 simple_unlink(parent->d_inode, tmp);
293         } else {
294                 spin_unlock(&tmp->d_lock);
295                 spin_unlock(&dcache_lock);
296         }
297
298         ret = 0;
299 bail:
300         /*
301          * We don't expect clients to care about the return value, but
302          * it's there if they need it.
303          */
304         return ret;
305 }
306
307 static int remove_device_files(struct super_block *sb,
308                                struct ipath_devdata *dd)
309 {
310         struct dentry *dir, *root;
311         char unit[10];
312         int ret;
313
314         root = dget(sb->s_root);
315         mutex_lock(&root->d_inode->i_mutex);
316         snprintf(unit, sizeof unit, "%02d", dd->ipath_unit);
317         dir = lookup_one_len(unit, root, strlen(unit));
318
319         if (IS_ERR(dir)) {
320                 ret = PTR_ERR(dir);
321                 printk(KERN_ERR "Lookup of %s failed\n", unit);
322                 goto bail;
323         }
324
325         remove_file(dir, "flash");
326         remove_file(dir, "atomic_counters");
327         d_delete(dir);
328         ret = simple_rmdir(root->d_inode, dir);
329
330 bail:
331         mutex_unlock(&root->d_inode->i_mutex);
332         dput(root);
333         return ret;
334 }
335
336 static int ipathfs_fill_super(struct super_block *sb, void *data,
337                               int silent)
338 {
339         struct ipath_devdata *dd, *tmp;
340         unsigned long flags;
341         int ret;
342
343         static struct tree_descr files[] = {
344                 [2] = {"atomic_stats", &atomic_stats_ops, S_IRUGO},
345                 {""},
346         };
347
348         ret = simple_fill_super(sb, IPATHFS_MAGIC, files);
349         if (ret) {
350                 printk(KERN_ERR "simple_fill_super failed: %d\n", ret);
351                 goto bail;
352         }
353
354         spin_lock_irqsave(&ipath_devs_lock, flags);
355
356         list_for_each_entry_safe(dd, tmp, &ipath_dev_list, ipath_list) {
357                 spin_unlock_irqrestore(&ipath_devs_lock, flags);
358                 ret = create_device_files(sb, dd);
359                 if (ret) {
360                         deactivate_super(sb);
361                         goto bail;
362                 }
363                 spin_lock_irqsave(&ipath_devs_lock, flags);
364         }
365
366         spin_unlock_irqrestore(&ipath_devs_lock, flags);
367
368 bail:
369         return ret;
370 }
371
372 static int ipathfs_get_sb(struct file_system_type *fs_type, int flags,
373                         const char *dev_name, void *data, struct vfsmount *mnt)
374 {
375         int ret = get_sb_single(fs_type, flags, data,
376                                     ipathfs_fill_super, mnt);
377         if (ret >= 0)
378                 ipath_super = mnt->mnt_sb;
379         return ret;
380 }
381
382 static void ipathfs_kill_super(struct super_block *s)
383 {
384         kill_litter_super(s);
385         ipath_super = NULL;
386 }
387
388 int ipathfs_add_device(struct ipath_devdata *dd)
389 {
390         int ret;
391
392         if (ipath_super == NULL) {
393                 ret = 0;
394                 goto bail;
395         }
396
397         ret = create_device_files(ipath_super, dd);
398
399 bail:
400         return ret;
401 }
402
403 int ipathfs_remove_device(struct ipath_devdata *dd)
404 {
405         int ret;
406
407         if (ipath_super == NULL) {
408                 ret = 0;
409                 goto bail;
410         }
411
412         ret = remove_device_files(ipath_super, dd);
413
414 bail:
415         return ret;
416 }
417
418 static struct file_system_type ipathfs_fs_type = {
419         .owner =        THIS_MODULE,
420         .name =         "ipathfs",
421         .get_sb =       ipathfs_get_sb,
422         .kill_sb =      ipathfs_kill_super,
423 };
424
425 int __init ipath_init_ipathfs(void)
426 {
427         return register_filesystem(&ipathfs_fs_type);
428 }
429
430 void __exit ipath_exit_ipathfs(void)
431 {
432         unregister_filesystem(&ipathfs_fs_type);
433 }