[TOKENRING]: Use interrupt-safe locking with rif_lock.

Change operations on rif_lock from spin_{un}lock_bh to
spin_{un}lock_irq{save,restore} equivalents. Some of the
rif_lock critical sections are called from interrupt context via
tr_type_trans->tr_add_rif_info. The TR NIC drivers call tr_type_trans
from their packet receive handlers.

Signed-off-by: Jay Vosburgh <[e-mail]>
Signed-off-by: John W. Linville <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

net/802/tr.c

···
 	unsigned int hash;
 	struct rif_cache *entry;
 	unsigned char *olddata;
+	unsigned long flags;
 	static const unsigned char mcast_func_addr[] 
 		= {0xC0,0x00,0x00,0x04,0x00,0x00};
 	
-	spin_lock_bh(&rif_lock);
+	spin_lock_irqsave(&rif_lock, flags);
 
 	/*
 	 *	Broadcasts are single route as stated in RFC 1042 
···
 	else 
 		slack = 18 - ((ntohs(trh->rcf) & TR_RCF_LEN_MASK)>>8);
 	olddata = skb->data;
-	spin_unlock_bh(&rif_lock);
+	spin_unlock_irqrestore(&rif_lock, flags);
 
 	skb_pull(skb, slack);
 	memmove(skb->data, olddata, sizeof(struct trh_hdr) - slack);
···
 static void tr_add_rif_info(struct trh_hdr *trh, struct net_device *dev)
 {
 	unsigned int hash, rii_p = 0;
+	unsigned long flags;
 	struct rif_cache *entry;
 
 
-	spin_lock_bh(&rif_lock);
+	spin_lock_irqsave(&rif_lock, flags);
 	
 	/*
 	 *	Firstly see if the entry exists
···
 		if(!entry) 
 		{
 			printk(KERN_DEBUG "tr.c: Couldn't malloc rif cache entry !\n");
-			spin_unlock_bh(&rif_lock);
+			spin_unlock_irqrestore(&rif_lock, flags);
 			return;
 		}
 
···
 		    }                                         
            	entry->last_used=jiffies;               
 	}
-	spin_unlock_bh(&rif_lock);
+	spin_unlock_irqrestore(&rif_lock, flags);
 }
 
 /*
···
 static void rif_check_expire(unsigned long dummy) 
 {
 	int i;
-	unsigned long next_interval = jiffies + sysctl_tr_rif_timeout/2;
+	unsigned long flags, next_interval = jiffies + sysctl_tr_rif_timeout/2;
 
-	spin_lock_bh(&rif_lock);
+	spin_lock_irqsave(&rif_lock, flags);
 	
 	for(i =0; i < RIF_TABLE_SIZE; i++) {
 		struct rif_cache *entry, **pentry;
···
 		}
 	}
 	
-	spin_unlock_bh(&rif_lock);
+	spin_unlock_irqrestore(&rif_lock, flags);
 
 	mod_timer(&rif_timer, next_interval);
 
···
 
 static void *rif_seq_start(struct seq_file *seq, loff_t *pos)
 {
-	spin_lock_bh(&rif_lock);
+	spin_lock_irq(&rif_lock);
 
 	return *pos ? rif_get_idx(*pos - 1) : SEQ_START_TOKEN;
 }
···
 
 static void rif_seq_stop(struct seq_file *seq, void *v)
 {
-	spin_unlock_bh(&rif_lock);
+	spin_unlock_irq(&rif_lock);
 }
 
 static int rif_seq_show(struct seq_file *seq, void *v)