mirror of
https://github.com/adulau/aha.git
synced 2024-12-27 19:26:25 +00:00
2bd9af046f
There's a circular locking dependency: ---> isdn_net_get_locked_lp --->lock &nd->queue_lock --->lock &nd->queue->xmit_lock ..................... ---->unlock &nd->queue_lock ---> isdn_net_writebuf_skb (called with &nd->queue->xmit_lock locked) ---->isdn_net_inc_frame_cnt ---->isdn_net_device_busy ----> lock &nd->queue_lock This will trigger lockdep warnings: ======================================================= [ INFO: possible circular locking dependency detected ] 2.6.32-rc4-testing #7 ------------------------------------------------------- ipppd/28379 is trying to acquire lock: (&netdev->queue_lock){......}, at: [<e62ad0fd>] isdn_net_device_busy+0x2c/0x74 [isdn] but task is already holding lock: (&netdev->local->xmit_lock){+.....}, at: [<e62aefc2>] isdn_net_write_super+0x3f/0x6e [isdn] which lock already depends on the new lock. ....... We don't need to lock nd->queue->xmit_lock to protect single isdn_net_lp_busy(). This can fix above lockdep warnings. Reported-and-tested-by: Tilman Schmidt <tilman@imap.cc> Signed-off-by: Xiaotian Feng <xtfeng@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
152 lines
4.9 KiB
C
152 lines
4.9 KiB
C
/* $Id: isdn_net.h,v 1.1.2.2 2004/01/12 22:37:19 keil Exp $
|
|
*
|
|
* header for Linux ISDN subsystem, network related functions (linklevel).
|
|
*
|
|
* Copyright 1994-1999 by Fritz Elfert (fritz@isdn4linux.de)
|
|
* Copyright 1995,96 by Thinking Objects Software GmbH Wuerzburg
|
|
* Copyright 1995,96 by Michael Hipp (Michael.Hipp@student.uni-tuebingen.de)
|
|
*
|
|
* This software may be used and distributed according to the terms
|
|
* of the GNU General Public License, incorporated herein by reference.
|
|
*
|
|
*/
|
|
|
|
/* Definitions for hupflags: */
|
|
#define ISDN_WAITCHARGE 1 /* did not get a charge info yet */
|
|
#define ISDN_HAVECHARGE 2 /* We know a charge info */
|
|
#define ISDN_CHARGEHUP 4 /* We want to use the charge mechanism */
|
|
#define ISDN_INHUP 8 /* Even if incoming, close after huptimeout */
|
|
#define ISDN_MANCHARGE 16 /* Charge Interval manually set */
|
|
|
|
/*
|
|
* Definitions for Cisco-HDLC header.
|
|
*/
|
|
|
|
#define CISCO_ADDR_UNICAST 0x0f
|
|
#define CISCO_ADDR_BROADCAST 0x8f
|
|
#define CISCO_CTRL 0x00
|
|
#define CISCO_TYPE_CDP 0x2000
|
|
#define CISCO_TYPE_SLARP 0x8035
|
|
#define CISCO_SLARP_REQUEST 0
|
|
#define CISCO_SLARP_REPLY 1
|
|
#define CISCO_SLARP_KEEPALIVE 2
|
|
|
|
extern char *isdn_net_new(char *, struct net_device *);
|
|
extern char *isdn_net_newslave(char *);
|
|
extern int isdn_net_rm(char *);
|
|
extern int isdn_net_rmall(void);
|
|
extern int isdn_net_stat_callback(int, isdn_ctrl *);
|
|
extern int isdn_net_setcfg(isdn_net_ioctl_cfg *);
|
|
extern int isdn_net_getcfg(isdn_net_ioctl_cfg *);
|
|
extern int isdn_net_addphone(isdn_net_ioctl_phone *);
|
|
extern int isdn_net_getphones(isdn_net_ioctl_phone *, char __user *);
|
|
extern int isdn_net_getpeer(isdn_net_ioctl_phone *, isdn_net_ioctl_phone __user *);
|
|
extern int isdn_net_delphone(isdn_net_ioctl_phone *);
|
|
extern int isdn_net_find_icall(int, int, int, setup_parm *);
|
|
extern void isdn_net_hangup(struct net_device *);
|
|
extern void isdn_net_dial(void);
|
|
extern void isdn_net_autohup(void);
|
|
extern int isdn_net_force_hangup(char *);
|
|
extern int isdn_net_force_dial(char *);
|
|
extern isdn_net_dev *isdn_net_findif(char *);
|
|
extern int isdn_net_rcv_skb(int, struct sk_buff *);
|
|
extern int isdn_net_dial_req(isdn_net_local *);
|
|
extern void isdn_net_writebuf_skb(isdn_net_local *lp, struct sk_buff *skb);
|
|
extern void isdn_net_write_super(isdn_net_local *lp, struct sk_buff *skb);
|
|
|
|
#define ISDN_NET_MAX_QUEUE_LENGTH 2
|
|
|
|
#define ISDN_MASTER_PRIV(lp) ((isdn_net_local *) netdev_priv(lp->master))
|
|
#define ISDN_SLAVE_PRIV(lp) ((isdn_net_local *) netdev_priv(lp->slave))
|
|
#define MASTER_TO_SLAVE(master) \
|
|
(((isdn_net_local *) netdev_priv(master))->slave)
|
|
|
|
/*
|
|
* is this particular channel busy?
|
|
*/
|
|
static __inline__ int isdn_net_lp_busy(isdn_net_local *lp)
|
|
{
|
|
if (atomic_read(&lp->frame_cnt) < ISDN_NET_MAX_QUEUE_LENGTH)
|
|
return 0;
|
|
else
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* For the given net device, this will get a non-busy channel out of the
|
|
* corresponding bundle. The returned channel is locked.
|
|
*/
|
|
static __inline__ isdn_net_local * isdn_net_get_locked_lp(isdn_net_dev *nd)
|
|
{
|
|
unsigned long flags;
|
|
isdn_net_local *lp;
|
|
|
|
spin_lock_irqsave(&nd->queue_lock, flags);
|
|
lp = nd->queue; /* get lp on top of queue */
|
|
while (isdn_net_lp_busy(nd->queue)) {
|
|
nd->queue = nd->queue->next;
|
|
if (nd->queue == lp) { /* not found -- should never happen */
|
|
lp = NULL;
|
|
goto errout;
|
|
}
|
|
}
|
|
lp = nd->queue;
|
|
nd->queue = nd->queue->next;
|
|
spin_unlock_irqrestore(&nd->queue_lock, flags);
|
|
spin_lock(&lp->xmit_lock);
|
|
local_bh_disable();
|
|
return lp;
|
|
errout:
|
|
spin_unlock_irqrestore(&nd->queue_lock, flags);
|
|
return lp;
|
|
}
|
|
|
|
/*
|
|
* add a channel to a bundle
|
|
*/
|
|
static __inline__ void isdn_net_add_to_bundle(isdn_net_dev *nd, isdn_net_local *nlp)
|
|
{
|
|
isdn_net_local *lp;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&nd->queue_lock, flags);
|
|
|
|
lp = nd->queue;
|
|
// printk(KERN_DEBUG "%s: lp:%s(%p) nlp:%s(%p) last(%p)\n",
|
|
// __func__, lp->name, lp, nlp->name, nlp, lp->last);
|
|
nlp->last = lp->last;
|
|
lp->last->next = nlp;
|
|
lp->last = nlp;
|
|
nlp->next = lp;
|
|
nd->queue = nlp;
|
|
|
|
spin_unlock_irqrestore(&nd->queue_lock, flags);
|
|
}
|
|
/*
|
|
* remove a channel from the bundle it belongs to
|
|
*/
|
|
static __inline__ void isdn_net_rm_from_bundle(isdn_net_local *lp)
|
|
{
|
|
isdn_net_local *master_lp = lp;
|
|
unsigned long flags;
|
|
|
|
if (lp->master)
|
|
master_lp = ISDN_MASTER_PRIV(lp);
|
|
|
|
// printk(KERN_DEBUG "%s: lp:%s(%p) mlp:%s(%p) last(%p) next(%p) mndq(%p)\n",
|
|
// __func__, lp->name, lp, master_lp->name, master_lp, lp->last, lp->next, master_lp->netdev->queue);
|
|
spin_lock_irqsave(&master_lp->netdev->queue_lock, flags);
|
|
lp->last->next = lp->next;
|
|
lp->next->last = lp->last;
|
|
if (master_lp->netdev->queue == lp) {
|
|
master_lp->netdev->queue = lp->next;
|
|
if (lp->next == lp) { /* last in queue */
|
|
master_lp->netdev->queue = master_lp->netdev->local;
|
|
}
|
|
}
|
|
lp->next = lp->last = lp; /* (re)set own pointers */
|
|
// printk(KERN_DEBUG "%s: mndq(%p)\n",
|
|
// __func__, master_lp->netdev->queue);
|
|
spin_unlock_irqrestore(&master_lp->netdev->queue_lock, flags);
|
|
}
|
|
|