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[PATCH] ipmi: use rcu lock for using command receivers 

Use rcu_read_lock for the cmd_rcvrs list, since that was what what
intended, anyway.  This means that all the users of the cmd_rcvrs_lock are
tasks, so the irq disables are no longer required for that lock and it can
become a semaphore.

Signed-off-by: Corey Minyard <minyard@acm.org>
Acked-by: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Corey Minyard 2005-11-07 01:00:05 -08:00 committed by Linus Torvalds
parent e9a705a0a0
commit e61fb5b651
1 changed files with 15 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

31
drivers/char/ipmi/ipmi_msghandler.c
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@ -209,7 +209,7 @@ struct ipmi_smi
/* The list of command receivers that are registered for commands
on this interface. */
spinlock_t cmd_rcvrs_lock;
struct semaphore cmd_rcvrs_lock;
struct list_head cmd_rcvrs;
/* Events that were queues because no one was there to receive
@ -345,7 +345,6 @@ static void clean_up_interface_data(ipmi_smi_t intf)
{
int i;
struct cmd_rcvr *rcvr, *rcvr2;
unsigned long flags;
struct list_head list;
free_recv_msg_list(&intf->waiting_msgs);
@ -353,10 +352,10 @@ static void clean_up_interface_data(ipmi_smi_t intf)
/* Wholesale remove all the entries from the list in the
* interface and wait for RCU to know that none are in use. */
spin_lock_irqsave(&intf->cmd_rcvrs_lock, flags);
down(&intf->cmd_rcvrs_lock);
list_add_rcu(&list, &intf->cmd_rcvrs);
list_del_rcu(&intf->cmd_rcvrs);
spin_unlock_irqrestore(&intf->cmd_rcvrs_lock, flags);
up(&intf->cmd_rcvrs_lock);
synchronize_rcu();
list_for_each_entry_safe(rcvr, rcvr2, &list, link)
@ -812,7 +811,7 @@ int ipmi_destroy_user(ipmi_user_t user)
* since other things may be using it till we do
* synchronize_rcu()) then free everything in that list.
*/
spin_lock_irqsave(&intf->cmd_rcvrs_lock, flags);
down(&intf->cmd_rcvrs_lock);
list_for_each_safe_rcu(entry1, entry2, &intf->cmd_rcvrs) {
rcvr = list_entry(entry1, struct cmd_rcvr, link);
if (rcvr->user == user) {
@ -821,7 +820,7 @@ int ipmi_destroy_user(ipmi_user_t user)
rcvrs = rcvr;
}
}
spin_unlock_irqrestore(&intf->cmd_rcvrs_lock, flags);
up(&intf->cmd_rcvrs_lock);
synchronize_rcu();
while (rcvrs) {
rcvr = rcvrs;
@ -950,7 +949,7 @@ int ipmi_register_for_cmd(ipmi_user_t user,
rcvr->netfn = netfn;
rcvr->user = user;
spin_lock_irq(&intf->cmd_rcvrs_lock);
down(&intf->cmd_rcvrs_lock);
/* Make sure the command/netfn is not already registered. */
entry = find_cmd_rcvr(intf, netfn, cmd);
if (entry) {
@ -961,7 +960,7 @@ int ipmi_register_for_cmd(ipmi_user_t user,
list_add_rcu(&rcvr->link, &intf->cmd_rcvrs);
out_unlock:
spin_unlock_irq(&intf->cmd_rcvrs_lock);
up(&intf->cmd_rcvrs_lock);
if (rv)
kfree(rcvr);
@ -975,17 +974,17 @@ int ipmi_unregister_for_cmd(ipmi_user_t user,
ipmi_smi_t intf = user->intf;
struct cmd_rcvr *rcvr;
spin_lock_irq(&intf->cmd_rcvrs_lock);
down(&intf->cmd_rcvrs_lock);
/* Make sure the command/netfn is not already registered. */
rcvr = find_cmd_rcvr(intf, netfn, cmd);
if ((rcvr) && (rcvr->user == user)) {
list_del_rcu(&rcvr->link);
spin_unlock_irq(&intf->cmd_rcvrs_lock);
up(&intf->cmd_rcvrs_lock);
synchronize_rcu();
kfree(rcvr);
return 0;
} else {
spin_unlock_irq(&intf->cmd_rcvrs_lock);
up(&intf->cmd_rcvrs_lock);
return -ENOENT;
}
}
@ -1858,7 +1857,7 @@ int ipmi_register_smi(struct ipmi_smi_handlers *handlers,
spin_lock_init(&intf->events_lock);
INIT_LIST_HEAD(&intf->waiting_events);
intf->waiting_events_count = 0;
spin_lock_init(&intf->cmd_rcvrs_lock);
init_MUTEX(&intf->cmd_rcvrs_lock);
INIT_LIST_HEAD(&intf->cmd_rcvrs);
init_waitqueue_head(&intf->waitq);
@ -2058,14 +2057,14 @@ static int handle_ipmb_get_msg_cmd(ipmi_smi_t intf,
netfn = msg->rsp[4] >> 2;
cmd = msg->rsp[8];
spin_lock_irqsave(&intf->cmd_rcvrs_lock, flags);
rcu_read_lock();
rcvr = find_cmd_rcvr(intf, netfn, cmd);
if (rcvr) {
user = rcvr->user;
kref_get(&user->refcount);
} else
user = NULL;
spin_unlock_irqrestore(&intf->cmd_rcvrs_lock, flags);
rcu_read_unlock();
if (user == NULL) {
/* We didn't find a user, deliver an error response. */
@ -2238,14 +2237,14 @@ static int handle_lan_get_msg_cmd(ipmi_smi_t intf,
netfn = msg->rsp[6] >> 2;
cmd = msg->rsp[10];
spin_lock_irqsave(&intf->cmd_rcvrs_lock, flags);
rcu_read_lock();
rcvr = find_cmd_rcvr(intf, netfn, cmd);
if (rcvr) {
user = rcvr->user;
kref_get(&user->refcount);
} else
user = NULL;
spin_unlock_irqrestore(&intf->cmd_rcvrs_lock, flags);
rcu_read_unlock();
if (user == NULL) {
/* We didn't find a user, just give up. */