Gigaset: permit module unload
Fix the initialization and reference counting of the Gigaset driver modules
so that they can be unloaded when they are not actually in use.
Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Cc: Hansjoerg Lipp <hjlipp@web.de>
Cc: Greg KH <gregkh@suse.de>
Cc: Karsten Keil <kkeil@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/isdn/gigaset/common.c b/drivers/isdn/gigaset/common.c
index f8f7d7e5..aacedec 100644
--- a/drivers/isdn/gigaset/common.c
+++ b/drivers/isdn/gigaset/common.c
@@ -31,7 +31,6 @@
/* driver state flags */
#define VALID_MINOR 0x01
#define VALID_ID 0x02
-#define ASSIGNED 0x04
void gigaset_dbg_buffer(enum debuglevel level, const unsigned char *msg,
size_t len, const unsigned char *buf)
@@ -178,7 +177,7 @@
unsigned long flags;
spin_lock_irqsave(&bcs->cs->lock, flags);
- if (bcs->use_count) {
+ if (bcs->use_count || !try_module_get(bcs->cs->driver->owner)) {
gig_dbg(DEBUG_ANY, "could not allocate channel %d",
bcs->channel);
spin_unlock_irqrestore(&bcs->cs->lock, flags);
@@ -203,6 +202,7 @@
}
--bcs->use_count;
bcs->busy = 0;
+ module_put(bcs->cs->driver->owner);
gig_dbg(DEBUG_ANY, "freed channel %d", bcs->channel);
spin_unlock_irqrestore(&bcs->cs->lock, flags);
}
@@ -356,31 +356,28 @@
{
unsigned long flags;
unsigned i;
+ struct cardstate *cs;
struct cardstate *ret = NULL;
spin_lock_irqsave(&drv->lock, flags);
+ if (drv->blocked)
+ goto exit;
for (i = 0; i < drv->minors; ++i) {
- if (!(drv->flags[i] & VALID_MINOR)) {
- if (try_module_get(drv->owner)) {
- drv->flags[i] = VALID_MINOR;
- ret = drv->cs + i;
- }
+ cs = drv->cs + i;
+ if (!(cs->flags & VALID_MINOR)) {
+ cs->flags = VALID_MINOR;
+ ret = cs;
break;
}
}
+exit:
spin_unlock_irqrestore(&drv->lock, flags);
return ret;
}
static void free_cs(struct cardstate *cs)
{
- unsigned long flags;
- struct gigaset_driver *drv = cs->driver;
- spin_lock_irqsave(&drv->lock, flags);
- if (drv->flags[cs->minor_index] & VALID_MINOR)
- module_put(drv->owner);
- drv->flags[cs->minor_index] = 0;
- spin_unlock_irqrestore(&drv->lock, flags);
+ cs->flags = 0;
}
static void make_valid(struct cardstate *cs, unsigned mask)
@@ -388,7 +385,7 @@
unsigned long flags;
struct gigaset_driver *drv = cs->driver;
spin_lock_irqsave(&drv->lock, flags);
- drv->flags[cs->minor_index] |= mask;
+ cs->flags |= mask;
spin_unlock_irqrestore(&drv->lock, flags);
}
@@ -397,7 +394,7 @@
unsigned long flags;
struct gigaset_driver *drv = cs->driver;
spin_lock_irqsave(&drv->lock, flags);
- drv->flags[cs->minor_index] &= ~mask;
+ cs->flags &= ~mask;
spin_unlock_irqrestore(&drv->lock, flags);
}
@@ -893,10 +890,17 @@
}
EXPORT_SYMBOL_GPL(gigaset_start);
-void gigaset_shutdown(struct cardstate *cs)
+/* gigaset_shutdown
+ * check if a device is associated to the cardstate structure and stop it
+ * return value: 0 if ok, -1 if no device was associated
+ */
+int gigaset_shutdown(struct cardstate *cs)
{
mutex_lock(&cs->mutex);
+ if (!(cs->flags & VALID_MINOR))
+ return -1;
+
cs->waiting = 1;
if (!gigaset_add_event(cs, &cs->at_state, EV_SHUTDOWN, NULL, 0, NULL)) {
@@ -913,6 +917,7 @@
exit:
mutex_unlock(&cs->mutex);
+ return 0;
}
EXPORT_SYMBOL_GPL(gigaset_shutdown);
@@ -954,13 +959,11 @@
list_for_each_entry(drv, &drivers, list) {
spin_lock(&drv->lock);
for (i = 0; i < drv->minors; ++i) {
- if (drv->flags[i] & VALID_ID) {
- cs = drv->cs + i;
- if (cs->myid == id)
- ret = cs;
- }
- if (ret)
+ cs = drv->cs + i;
+ if ((cs->flags & VALID_ID) && cs->myid == id) {
+ ret = cs;
break;
+ }
}
spin_unlock(&drv->lock);
if (ret)
@@ -983,10 +986,9 @@
spin_lock(&drv->lock);
for (i = 0; i < drv->minors; ++i) {
gig_dbg(DEBUG_DRIVER, " index %u", i);
- gig_dbg(DEBUG_DRIVER, " flags 0x%02x",
- drv->flags[i]);
cs = drv->cs + i;
gig_dbg(DEBUG_DRIVER, " cardstate %p", cs);
+ gig_dbg(DEBUG_DRIVER, " flags 0x%02x", cs->flags);
gig_dbg(DEBUG_DRIVER, " minor_index %u",
cs->minor_index);
gig_dbg(DEBUG_DRIVER, " driver %p", cs->driver);
@@ -1010,7 +1012,7 @@
continue;
index = minor - drv->minor;
spin_lock(&drv->lock);
- if (drv->flags[index] & VALID_MINOR)
+ if (drv->cs[index].flags & VALID_MINOR)
ret = drv->cs + index;
spin_unlock(&drv->lock);
if (ret)
@@ -1038,7 +1040,6 @@
gigaset_if_freedriver(drv);
kfree(drv->cs);
- kfree(drv->flags);
kfree(drv);
}
EXPORT_SYMBOL_GPL(gigaset_freedriver);
@@ -1080,12 +1081,8 @@
if (!drv->cs)
goto error;
- drv->flags = kmalloc(minors * sizeof *drv->flags, GFP_KERNEL);
- if (!drv->flags)
- goto error;
-
for (i = 0; i < minors; ++i) {
- drv->flags[i] = 0;
+ drv->cs[i].flags = 0;
drv->cs[i].driver = drv;
drv->cs[i].ops = drv->ops;
drv->cs[i].minor_index = i;
@@ -1106,53 +1103,9 @@
}
EXPORT_SYMBOL_GPL(gigaset_initdriver);
-/* For drivers without fixed assignment device<->cardstate (usb) */
-struct cardstate *gigaset_getunassignedcs(struct gigaset_driver *drv)
-{
- unsigned long flags;
- struct cardstate *cs = NULL;
- unsigned i;
-
- spin_lock_irqsave(&drv->lock, flags);
- if (drv->blocked)
- goto exit;
- for (i = 0; i < drv->minors; ++i) {
- if ((drv->flags[i] & VALID_MINOR) &&
- !(drv->flags[i] & ASSIGNED)) {
- drv->flags[i] |= ASSIGNED;
- cs = drv->cs + i;
- break;
- }
- }
-exit:
- spin_unlock_irqrestore(&drv->lock, flags);
- return cs;
-}
-EXPORT_SYMBOL_GPL(gigaset_getunassignedcs);
-
-void gigaset_unassign(struct cardstate *cs)
-{
- unsigned long flags;
- unsigned *minor_flags;
- struct gigaset_driver *drv;
-
- if (!cs)
- return;
- drv = cs->driver;
- spin_lock_irqsave(&drv->lock, flags);
- minor_flags = drv->flags + cs->minor_index;
- if (*minor_flags & VALID_MINOR)
- *minor_flags &= ~ASSIGNED;
- spin_unlock_irqrestore(&drv->lock, flags);
-}
-EXPORT_SYMBOL_GPL(gigaset_unassign);
-
void gigaset_blockdriver(struct gigaset_driver *drv)
{
- unsigned long flags;
- spin_lock_irqsave(&drv->lock, flags);
drv->blocked = 1;
- spin_unlock_irqrestore(&drv->lock, flags);
}
EXPORT_SYMBOL_GPL(gigaset_blockdriver);