From db34a363b992e0c8063f432607561520d79fbfb8 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Fri, 22 Jul 2011 08:13:05 +0100 Subject: x86/PCI: config space accessor functions should not ignore the segment argument Without this change, the majority of the raw PCI config space access functions silently ignore a non-zero segment argument, which is certainly wrong. Apart from pci_direct_conf1, all other non-MMCFG access methods get used only for non-extended accesses (i.e. assigned to raw_pci_ops only). Consequently, with the way raw_pci_{read,write}() work, it would be a coding error to call these functions with a non-zero segment (with the current call flow this cannot happen afaict). The access method 1 accessor, as it can be used for extended accesses (on AMD systems) instead gets checks added for the passed in segment to be zero. This would be the case when on such a system having multiple PCI segments (don't know whether any exist in practice) MMCFG for some reason is not usable, and method 1 gets selected for doing extended accesses. Rather than accessing the wrong device's config space, the function will now error out. v2: Convert BUG_ON() to WARN_ON(), and extend description as per Ingo's request. Signed-off-by: Jan Beulich Reviewed-by: Ingo Molnar Signed-off-by: Jesse Barnes --- arch/x86/pci/pcbios.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/x86/pci/pcbios.c') diff --git a/arch/x86/pci/pcbios.c b/arch/x86/pci/pcbios.c index a5f7d0d63de..f6855355146 100644 --- a/arch/x86/pci/pcbios.c +++ b/arch/x86/pci/pcbios.c @@ -181,6 +181,7 @@ static int pci_bios_read(unsigned int seg, unsigned int bus, unsigned long flags; unsigned long bx = (bus << 8) | devfn; + WARN_ON(seg); if (!value || (bus > 255) || (devfn > 255) || (reg > 255)) return -EINVAL; @@ -247,6 +248,7 @@ static int pci_bios_write(unsigned int seg, unsigned int bus, unsigned long flags; unsigned long bx = (bus << 8) | devfn; + WARN_ON(seg); if ((bus > 255) || (devfn > 255) || (reg > 255)) return -EINVAL; -- cgit v1.2.3-18-g5258