[PATCH] Fix SMP support on 3c527 net driver

[Felipe W Damasio <felipewd@terra.com.br>]

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	Hi Richard,

	Patch against 2.6.0-test4

	This is a first try to fix SMP support on the 3c527 net driver, by 
removing cli/sti and replacing them with proper locking.

	Since the critical section that used cli/save_flags to serialize its 
access had "sleep_on" in it, I added a per-device semaphore to it, and 
used this lock instead. Also, the down/up function doesn't seem to be 
used in interrupt context, so I think it will work.

	Compile fine, but I don't have the hardware to test it.

	Please review this patch and consider applying if it looks good,

	Thanks.

Felipe
-- 
It's most certainly GNU/Linux, not Linux. Read more at
http://www.gnu.org/gnu/why-gnu-linux.html

[-- Attachment #2: 3c527-smp.patch --]
[-- Type: text/plain, Size: 2773 bytes --]

--- linux-2.6.0-test4/drivers/net/3c527.c	Fri Aug 22 20:56:34 2003
+++ linux-2.6.0-test4-fwd/drivers/net/3c527.c	Sat Aug 30 23:57:25 2003
@@ -17,8 +17,8 @@
  */
 
 #define DRV_NAME		"3c527"
-#define DRV_VERSION		"0.6a"
-#define DRV_RELDATE		"2001/11/17"
+#define DRV_VERSION		"0.6b"
+#define DRV_RELDATE		"2003/08/31"
 
 static const char *version =
 DRV_NAME ".c:v" DRV_VERSION " " DRV_RELDATE " Richard Proctor (rnp@netlink.co.nz)\n";
@@ -174,6 +174,8 @@
 
 	struct mc32_ring_desc tx_ring[TX_RING_LEN];	/* Host Transmit ring */
 	struct mc32_ring_desc rx_ring[RX_RING_LEN];	/* Host Receive ring */
+	
+	struct semaphore mc32_sem;
 
 	u16 tx_ring_tail;       /* index to tx de-queue end */
 	u16 tx_ring_head;       /* index to tx en-queue end */
@@ -615,16 +617,14 @@
 {
 	struct mc32_local *lp = (struct mc32_local *)dev->priv;
 	int ioaddr = dev->base_addr;
-	unsigned long flags;
 	int ret = 0;
 	
 	/*
 	 *	Wait for a command
 	 */
 	 
-	save_flags(flags);
-	cli();
-	 
+	down(&lp->mc32_sem);
+	
 	while(lp->exec_pending)
 		sleep_on(&lp->event);
 		
@@ -634,7 +634,7 @@
 
 	lp->exec_pending=1;
 	
-	restore_flags(flags);
+	up(&lp->mc32_sem);
 	
 	lp->exec_box->mbox=0;
 	lp->exec_box->mbox=cmd;
@@ -645,13 +645,12 @@
 	while(!(inb(ioaddr+HOST_STATUS)&HOST_STATUS_CRR));
 	outb(1<<6, ioaddr+HOST_CMD);	
 
-	save_flags(flags);
-	cli();
+	down(&lp->mc32_sem);
 
 	while(lp->exec_pending!=2)
 		sleep_on(&lp->event);
 	lp->exec_pending=0;
-	restore_flags(flags);
+	up(&lp->mc32_sem);
 	
 	if(lp->exec_box->mbox&(1<<13))
 		ret = -1;
@@ -725,7 +724,6 @@
 {
 	struct mc32_local *lp = (struct mc32_local *)dev->priv;
 	int ioaddr = dev->base_addr;
-	unsigned long flags;
 
 	mc32_ready_poll(dev);	
 
@@ -735,14 +733,13 @@
 	outb(HOST_CMD_SUSPND_RX, ioaddr+HOST_CMD);			
 	mc32_ready_poll(dev); 
 	outb(HOST_CMD_SUSPND_TX, ioaddr+HOST_CMD);	
-		
-	save_flags(flags);
-	cli();
+	
+	down(&lp->mc32_sem);
 		
 	while(lp->xceiver_state!=HALTED) 
 		sleep_on(&lp->event); 
 		
-	restore_flags(flags);	
+	up(&lp->mc32_sem);
 } 
 
 
@@ -1008,6 +1005,7 @@
 		return -ENOBUFS;
 	}
 
+	init_MUTEX(&lp->mc32_sem);
 	lp->desired_state = RUNNING; 
 	
 	/* And finally, set the ball rolling... */
@@ -1056,18 +1054,16 @@
 static int mc32_send_packet(struct sk_buff *skb, struct net_device *dev)
 {
 	struct mc32_local *lp = (struct mc32_local *)dev->priv;
-	unsigned long flags;
 
 	volatile struct skb_header *p, *np;
 
 	netif_stop_queue(dev);
 
-	save_flags(flags);
-	cli();
+	down(&lp->mc32_sem);
 		
 	if(atomic_read(&lp->tx_count)==0)
 	{
-		restore_flags(flags);
+		up(&lp->mc32_sem);
 		return 1;
 	}
 
@@ -1098,7 +1094,7 @@
 		
 	p->control     &= ~CONTROL_EOL;     /* Clear EOL on p */ 
 out:	
-	restore_flags(flags);
+	up(&lp->mc32_sem);
 
 	netif_wake_queue(dev);
 	return 0;