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

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

[Olof Johansson]

Hi,

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>

Index: 2.6/drivers/pci/probe.c
===================================================================
--- 2.6.orig/drivers/pci/probe.c	2005-06-10 15:09:37.000000000 -0500
+++ 2.6/drivers/pci/probe.c	2005-06-10 15:43:36.000000000 -0500
@@ -125,7 +125,7 @@ static inline unsigned int pci_calc_reso
 /*
  * 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)