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/direct.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'arch/x86/pci/direct.c') diff --git a/arch/x86/pci/direct.c b/arch/x86/pci/direct.c index e6fd8473fb7b..4f2c70439d7f 100644 --- a/arch/x86/pci/direct.c +++ b/arch/x86/pci/direct.c @@ -22,7 +22,7 @@ static int pci_conf1_read(unsigned int seg, unsigned int bus, { unsigned long flags; - if ((bus > 255) || (devfn > 255) || (reg > 4095)) { + if (seg || (bus > 255) || (devfn > 255) || (reg > 4095)) { *value = -1; return -EINVAL; } @@ -53,7 +53,7 @@ static int pci_conf1_write(unsigned int seg, unsigned int bus, { unsigned long flags; - if ((bus > 255) || (devfn > 255) || (reg > 4095)) + if (seg || (bus > 255) || (devfn > 255) || (reg > 4095)) return -EINVAL; raw_spin_lock_irqsave(&pci_config_lock, flags); @@ -97,6 +97,7 @@ static int pci_conf2_read(unsigned int seg, unsigned int bus, unsigned long flags; int dev, fn; + WARN_ON(seg); if ((bus > 255) || (devfn > 255) || (reg > 255)) { *value = -1; return -EINVAL; @@ -138,6 +139,7 @@ static int pci_conf2_write(unsigned int seg, unsigned int bus, unsigned long flags; int dev, fn; + WARN_ON(seg); if ((bus > 255) || (devfn > 255) || (reg > 255)) return -EINVAL; -- cgit v1.2.3-55-g7522