[PATCH] Fix PCI BAR size interpretation on 64-bit arches

On 64-bit machines, PCI_BASE_ADDRESS_MEM_MASK and other mask constants
passed to pci_size() are 64-bit (for example ~0x0fUL).  However, pci_size
does comparisons between the u32 arguments and the mask, which will fail
even though any result from pci_size is still just 32-bit.

Changing the mask argument to u32 seems the obvious thing to do, since all
arithmetic in the function is 32-bit and having a larger mask makes no
sense.

This triggered on a PPC64 system here where an adapter (VGA, as it
happened) had a memory region base of 0xfe000000 and a sz of the same,
matching the if (max == maxbase ...) test at the bottom of pci_size but
failing the mask comparison.  Quite a corner case which I guess explains
why we haven't seen it until now.

Signed-off-by: Olof Johansson <olof@lixom.net>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index b7ae878..fd48b20 100644 (file)
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -125,7 +125,7 @@ static inline unsigned int pci_calc_resource_flags(unsigned int flags)
 /*
  * Find the extent of a PCI decode..
  */
-static u32 pci_size(u32 base, u32 maxbase, unsigned long mask)
+static u32 pci_size(u32 base, u32 maxbase, u32 mask)
 {
        u32 size = mask & maxbase;      /* Find the significant bits */
        if (!size)