[PATCH] ppc32: fix locking bugs in mv64x60 code

This patch fixes 2 SMP deadlocks.  The first is that mv64x60_read() was
returning before the unlock.  The second was mv64x60_modify() locks the
spin lock and calls mv64x60_read() and mv64x60_write() which also lock the
same spin lock.
Signed-Off-By: Brian Waite <waite@skycomputers.com>
Signed-off-by: Mark A. Greer <mgreer@mvista.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/ppc/syslib/mv64x60.c

@@ -32,7 +32,7 @@
 
 
 u8		mv64x60_pci_exclude_bridge = 1;
-spinlock_t	mv64x60_lock; /* Only really used by PIC code once init done */
+spinlock_t	mv64x60_lock = SPIN_LOCK_UNLOCKED;
 
 static phys_addr_t 	mv64x60_bridge_pbase = 0;
 static void 		*mv64x60_bridge_vbase = 0;

include/asm-ppc/mv64x60.h

@@ -254,10 +254,12 @@ mv64x60_write(struct mv64x60_handle *bh, u32 offset, u32 val) {
 extern inline u32
 mv64x60_read(struct mv64x60_handle *bh, u32 offset) {
 	ulong	flags;
+	u32     reg;
 
 	spin_lock_irqsave(&mv64x60_lock, flags);
-	return in_le32(bh->v_base + offset);
+	reg = in_le32(bh->v_base + offset);
 	spin_unlock_irqrestore(&mv64x60_lock, flags);
+	return reg;
 }
 
 extern inline void
@@ -267,9 +269,9 @@ mv64x60_modify(struct mv64x60_handle *bh, u32 offs, u32 data, u32 mask)
 	ulong	flags;
 
 	spin_lock_irqsave(&mv64x60_lock, flags);
-	reg = mv64x60_read(bh, offs) & (~mask); /* zero bits we care about */
-	reg |= data & mask; /* set bits from the data */
-	mv64x60_write(bh, offs, reg);
+	reg = in_le32(bh->v_base + offs) & (~mask);
+	reg |= data & mask;
+	out_le32(bh->v_base + offs, reg);
 	spin_unlock_irqrestore(&mv64x60_lock, flags);
 }