diff options
author | Matthias Kaehlcke <matthias.kaehlcke@gmail.com> | 2007-05-08 03:32:08 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-05-08 14:15:15 -0400 |
commit | 0e82d5b61841f2b9e2d31a4299ce09752c5d3288 (patch) | |
tree | b8d6009112eb44425fca70779f4bc2337e9df6ca /drivers | |
parent | 6acc369a43ada9b829b3e1e4daef5c8a52a2d39a (diff) |
use mutex instead of semaphore for misc char devices
The misc character device driver uses a semaphore as mutex. Use the mutex API
instead of the (binary) semaphore.
Signed-off-by: Matthias Kaehlcke <matthias.kaehlcke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/char/misc.c | 27 |
1 files changed, 14 insertions, 13 deletions
diff --git a/drivers/char/misc.c b/drivers/char/misc.c index 7e975f606924..4e6fb9651a16 100644 --- a/drivers/char/misc.c +++ b/drivers/char/misc.c | |||
@@ -41,6 +41,7 @@ | |||
41 | #include <linux/kernel.h> | 41 | #include <linux/kernel.h> |
42 | #include <linux/major.h> | 42 | #include <linux/major.h> |
43 | #include <linux/slab.h> | 43 | #include <linux/slab.h> |
44 | #include <linux/mutex.h> | ||
44 | #include <linux/proc_fs.h> | 45 | #include <linux/proc_fs.h> |
45 | #include <linux/seq_file.h> | 46 | #include <linux/seq_file.h> |
46 | #include <linux/stat.h> | 47 | #include <linux/stat.h> |
@@ -53,7 +54,7 @@ | |||
53 | * Head entry for the doubly linked miscdevice list | 54 | * Head entry for the doubly linked miscdevice list |
54 | */ | 55 | */ |
55 | static LIST_HEAD(misc_list); | 56 | static LIST_HEAD(misc_list); |
56 | static DECLARE_MUTEX(misc_sem); | 57 | static DEFINE_MUTEX(misc_mtx); |
57 | 58 | ||
58 | /* | 59 | /* |
59 | * Assigned numbers, used for dynamic minors | 60 | * Assigned numbers, used for dynamic minors |
@@ -69,7 +70,7 @@ static void *misc_seq_start(struct seq_file *seq, loff_t *pos) | |||
69 | struct miscdevice *p; | 70 | struct miscdevice *p; |
70 | loff_t off = 0; | 71 | loff_t off = 0; |
71 | 72 | ||
72 | down(&misc_sem); | 73 | mutex_lock(&misc_mtx); |
73 | list_for_each_entry(p, &misc_list, list) { | 74 | list_for_each_entry(p, &misc_list, list) { |
74 | if (*pos == off++) | 75 | if (*pos == off++) |
75 | return p; | 76 | return p; |
@@ -89,7 +90,7 @@ static void *misc_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |||
89 | 90 | ||
90 | static void misc_seq_stop(struct seq_file *seq, void *v) | 91 | static void misc_seq_stop(struct seq_file *seq, void *v) |
91 | { | 92 | { |
92 | up(&misc_sem); | 93 | mutex_unlock(&misc_mtx); |
93 | } | 94 | } |
94 | 95 | ||
95 | static int misc_seq_show(struct seq_file *seq, void *v) | 96 | static int misc_seq_show(struct seq_file *seq, void *v) |
@@ -129,7 +130,7 @@ static int misc_open(struct inode * inode, struct file * file) | |||
129 | int err = -ENODEV; | 130 | int err = -ENODEV; |
130 | const struct file_operations *old_fops, *new_fops = NULL; | 131 | const struct file_operations *old_fops, *new_fops = NULL; |
131 | 132 | ||
132 | down(&misc_sem); | 133 | mutex_lock(&misc_mtx); |
133 | 134 | ||
134 | list_for_each_entry(c, &misc_list, list) { | 135 | list_for_each_entry(c, &misc_list, list) { |
135 | if (c->minor == minor) { | 136 | if (c->minor == minor) { |
@@ -139,9 +140,9 @@ static int misc_open(struct inode * inode, struct file * file) | |||
139 | } | 140 | } |
140 | 141 | ||
141 | if (!new_fops) { | 142 | if (!new_fops) { |
142 | up(&misc_sem); | 143 | mutex_unlock(&misc_mtx); |
143 | request_module("char-major-%d-%d", MISC_MAJOR, minor); | 144 | request_module("char-major-%d-%d", MISC_MAJOR, minor); |
144 | down(&misc_sem); | 145 | mutex_lock(&misc_mtx); |
145 | 146 | ||
146 | list_for_each_entry(c, &misc_list, list) { | 147 | list_for_each_entry(c, &misc_list, list) { |
147 | if (c->minor == minor) { | 148 | if (c->minor == minor) { |
@@ -165,7 +166,7 @@ static int misc_open(struct inode * inode, struct file * file) | |||
165 | } | 166 | } |
166 | fops_put(old_fops); | 167 | fops_put(old_fops); |
167 | fail: | 168 | fail: |
168 | up(&misc_sem); | 169 | mutex_unlock(&misc_mtx); |
169 | return err; | 170 | return err; |
170 | } | 171 | } |
171 | 172 | ||
@@ -201,10 +202,10 @@ int misc_register(struct miscdevice * misc) | |||
201 | 202 | ||
202 | INIT_LIST_HEAD(&misc->list); | 203 | INIT_LIST_HEAD(&misc->list); |
203 | 204 | ||
204 | down(&misc_sem); | 205 | mutex_lock(&misc_mtx); |
205 | list_for_each_entry(c, &misc_list, list) { | 206 | list_for_each_entry(c, &misc_list, list) { |
206 | if (c->minor == misc->minor) { | 207 | if (c->minor == misc->minor) { |
207 | up(&misc_sem); | 208 | mutex_unlock(&misc_mtx); |
208 | return -EBUSY; | 209 | return -EBUSY; |
209 | } | 210 | } |
210 | } | 211 | } |
@@ -215,7 +216,7 @@ int misc_register(struct miscdevice * misc) | |||
215 | if ( (misc_minors[i>>3] & (1 << (i&7))) == 0) | 216 | if ( (misc_minors[i>>3] & (1 << (i&7))) == 0) |
216 | break; | 217 | break; |
217 | if (i<0) { | 218 | if (i<0) { |
218 | up(&misc_sem); | 219 | mutex_unlock(&misc_mtx); |
219 | return -EBUSY; | 220 | return -EBUSY; |
220 | } | 221 | } |
221 | misc->minor = i; | 222 | misc->minor = i; |
@@ -238,7 +239,7 @@ int misc_register(struct miscdevice * misc) | |||
238 | */ | 239 | */ |
239 | list_add(&misc->list, &misc_list); | 240 | list_add(&misc->list, &misc_list); |
240 | out: | 241 | out: |
241 | up(&misc_sem); | 242 | mutex_unlock(&misc_mtx); |
242 | return err; | 243 | return err; |
243 | } | 244 | } |
244 | 245 | ||
@@ -259,13 +260,13 @@ int misc_deregister(struct miscdevice * misc) | |||
259 | if (list_empty(&misc->list)) | 260 | if (list_empty(&misc->list)) |
260 | return -EINVAL; | 261 | return -EINVAL; |
261 | 262 | ||
262 | down(&misc_sem); | 263 | mutex_lock(&misc_mtx); |
263 | list_del(&misc->list); | 264 | list_del(&misc->list); |
264 | device_destroy(misc_class, MKDEV(MISC_MAJOR, misc->minor)); | 265 | device_destroy(misc_class, MKDEV(MISC_MAJOR, misc->minor)); |
265 | if (i < DYNAMIC_MINORS && i>0) { | 266 | if (i < DYNAMIC_MINORS && i>0) { |
266 | misc_minors[i>>3] &= ~(1 << (misc->minor & 7)); | 267 | misc_minors[i>>3] &= ~(1 << (misc->minor & 7)); |
267 | } | 268 | } |
268 | up(&misc_sem); | 269 | mutex_unlock(&misc_mtx); |
269 | return 0; | 270 | return 0; |
270 | } | 271 | } |
271 | 272 | ||