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>
diff --git a/arch/x86/pci/direct.c b/arch/x86/pci/direct.c
index e6fd847..4f2c704 100644
--- a/arch/x86/pci/direct.c
+++ b/arch/x86/pci/direct.c
@@ -22,7 +22,7 @@
{
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 @@
{
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 @@
unsigned long flags;
int dev, fn;
+ WARN_ON(seg);
if ((bus > 255) || (devfn > 255) || (reg > 255)) {
*value = -1;
return -EINVAL;
@@ -138,6 +139,7 @@
unsigned long flags;
int dev, fn;
+ WARN_ON(seg);
if ((bus > 255) || (devfn > 255) || (reg > 255))
return -EINVAL;