[SCSI] megaraid: fix MMIO casts

megaraid's MMIO RD*/WR* macros directly call readl() and writel() with
an 'unsigned long' argument.  This throws a warning, but is otherwise OK
because the 'unsigned long' is really the result of ioremap().  This
setup is also OK because the variable can hold an ioremap cookie /or/ a
PCI I/O port (PIO).

However, to fix the warning thrown when readl() and writel() are passed
an unsigned long cookie, I introduce 'void __iomem *mmio_base', holding
the same value as 'base'.  This will silence the warnings, and also
cause an oops whenever these MMIO-only functions are ever accidentally
passed an I/O address.
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/megaraid.c

@@ -73,10 +73,10 @@ static unsigned short int max_mbox_busy_wait = MBOX_BUSY_WAIT;
 module_param(max_mbox_busy_wait, ushort, 0);
 MODULE_PARM_DESC(max_mbox_busy_wait, "Maximum wait for mailbox in microseconds if busy (default=MBOX_BUSY_WAIT=10)");
 
-#define RDINDOOR(adapter)		readl((adapter)->base + 0x20)
-#define RDOUTDOOR(adapter)		readl((adapter)->base + 0x2C)
-#define WRINDOOR(adapter,value)		writel(value, (adapter)->base + 0x20)
-#define WROUTDOOR(adapter,value)	writel(value, (adapter)->base + 0x2C)
+#define RDINDOOR(adapter)	readl((adapter)->mmio_base + 0x20)
+#define RDOUTDOOR(adapter)	readl((adapter)->mmio_base + 0x2C)
+#define WRINDOOR(adapter,value)	 writel(value, (adapter)->mmio_base + 0x20)
+#define WROUTDOOR(adapter,value) writel(value, (adapter)->mmio_base + 0x2C)
 
 /*
  * Global variables
@@ -1386,7 +1386,8 @@ megaraid_isr_memmapped(int irq, void *devp)
 
 		handled = 1;
 
-		while( RDINDOOR(adapter) & 0x02 ) cpu_relax();
+		while( RDINDOOR(adapter) & 0x02 )
+			cpu_relax();
 
 		mega_cmd_done(adapter, completed, nstatus, status);
 
@@ -4668,6 +4669,8 @@ megaraid_probe_one(struct pci_dev *pdev, const struct pci_device_id *id)
 		host->host_no, mega_baseport, irq);
 
 	adapter->base = mega_baseport;
+	if (flag & BOARD_MEMMAP)
+		adapter->mmio_base = (void __iomem *) mega_baseport;
 
 	INIT_LIST_HEAD(&adapter->free_list);
 	INIT_LIST_HEAD(&adapter->pending_list);

drivers/scsi/megaraid.h

@@ -802,6 +802,7 @@ typedef struct {
 	u32	flag;
 
 	unsigned long		base;
+	void __iomem		*mmio_base;
 
 	/* mbox64 with mbox not aligned on 16-byte boundry */
 	mbox64_t	*una_mbox64;