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
46static struct super_block *ipath_super;
47
48static 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
75bail:
76	return error;
77}
78
79static 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
97static 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
104static const struct file_operations atomic_stats_ops = {
105	.read = atomic_stats_read,
106	.llseek = default_llseek,
107};
108
109static 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
122static const struct file_operations atomic_counters_ops = {
123	.read = atomic_counters_read,
124	.llseek = default_llseek,
125};
126
127static 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
171bail_tmp:
172	kfree(tmp);
173
174bail:
175	return ret;
176}
177
178static 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
219bail_tmp:
220	kfree(tmp);
221
222bail:
223	return ret;
224}
225
226static const struct file_operations flash_ops = {
227	.read = flash_read,
228	.write = flash_write,
229	.llseek = default_llseek,
230};
231
232static 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
263bail:
264	return ret;
265}
266
267static 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;
289bail:
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
297static 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
320bail:
321	mutex_unlock(&d_inode(root)->i_mutex);
322	dput(root);
323	return ret;
324}
325
326static 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
356bail:
357	return ret;
358}
359
360static 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
370static void ipathfs_kill_super(struct super_block *s)
371{
372	kill_litter_super(s);
373	ipath_super = NULL;
374}
375
376int 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
387bail:
388	return ret;
389}
390
391int 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
402bail:
403	return ret;
404}
405
406static 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};
412MODULE_ALIAS_FS("ipathfs");
413
414int __init ipath_init_ipathfs(void)
415{
416	return register_filesystem(&ipathfs_fs_type);
417}
418
419void __exit ipath_exit_ipathfs(void)
420{
421	unregister_filesystem(&ipathfs_fs_type);
422}
423