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| author | Jan Beulich <JBeulich@novell.com> | 2011-07-22 11:13:05 +0400 |
|---|---|---|
| committer | Jesse Barnes <jbarnes@virtuousgeek.org> | 2011-07-22 19:25:41 +0400 |
| commit | db34a363b992e0c8063f432607561520d79fbfb8 (patch) | |
| tree | d57b4e848eeccade7dd81e39832215bdec3f52b7 /arch/x86/pci/pcbios.c | |
| parent | 688398bb7b9c6ac115da7749ea808d3ef69e029f (diff) | |
| download | linux-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/pcbios.c')
| -rw-r--r-- | arch/x86/pci/pcbios.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/pci/pcbios.c b/arch/x86/pci/pcbios.c index a5f7d0d63de0..f68553551467 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; |