From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261366AbVFJWpC (ORCPT ); Fri, 10 Jun 2005 18:45:02 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261388AbVFJWpB (ORCPT ); Fri, 10 Jun 2005 18:45:01 -0400 Received: from zeus1.kernel.org ([204.152.191.4]:35050 "EHLO zeus1.kernel.org") by vger.kernel.org with ESMTP id S261370AbVFJWoP (ORCPT ); Fri, 10 Jun 2005 18:44:15 -0400 Date: Fri, 10 Jun 2005 16:22:52 -0500 To: linux-kernel@vger.kernel.org Cc: linux-pci@atrey.karlin.mff.cuni.cz, greg@kroah.com, akpm@osdl.org, linuxppc64-dev@ozlabs.org Subject: [PATCH] Fix PCI BAR size interpretation on 64-bit arches Message-ID: <20050610212252.GA28655@austin.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.6+20040907i From: Olof Johansson Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org 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 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)