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authorJan Beulich <JBeulich@novell.com>2011-07-22 11:13:05 +0400
committerJesse Barnes <jbarnes@virtuousgeek.org>2011-07-22 19:25:41 +0400
commitdb34a363b992e0c8063f432607561520d79fbfb8 (patch)
treed57b4e848eeccade7dd81e39832215bdec3f52b7 /arch/x86/pci/direct.c
parent688398bb7b9c6ac115da7749ea808d3ef69e029f (diff)
downloadlinux-db34a363b992e0c8063f432607561520d79fbfb8.tar.xz
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 <jbeulich@novell.com> Reviewed-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Diffstat (limited to 'arch/x86/pci/direct.c')
-rw-r--r--arch/x86/pci/direct.c6
1 files changed, 4 insertions, 2 deletions
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;