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x86/pci/mrst: Use configuration mechanism 1 for 00:00.0, 00:02.0, 00:03.0

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For real PCI devices 00:00.0, 00:02.0 and 00:03.0, there is either no
PCI shim, or no guarantee of data correctness of offset 256-4k.  So for
whatever reason, Linux kernel should not do MMCFG PCI config access to
those devices.  Instead, always use configuration mechanism 1 for those
devices.

The 00:00.0, 00:02.0 and 00:03.0 devices are built-in single-function
devices and are not PCI-PCI bridges, so this set of devices should be
complete.

Signed-off-by: Bin Gao <bin.gao@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
This commit is contained in:
Bin Gao
2013-04-30 00:21:47 -07:00
committed by Bjorn Helgaas
parent e5f66eafe5
commit dd72be99d1
1 changed files with 6 additions and 4 deletions
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10
arch/x86/pci/mrst.c
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@@ -141,6 +141,11 @@ static int pci_device_update_fixed(struct pci_bus *bus, unsigned int devfn,
*/ */
static bool type1_access_ok(unsigned int bus, unsigned int devfn, int reg) static bool type1_access_ok(unsigned int bus, unsigned int devfn, int reg)
{ {
if (bus == 0 && (devfn == PCI_DEVFN(2, 0)
|| devfn == PCI_DEVFN(0, 0)
|| devfn == PCI_DEVFN(3, 0)))
return 1;
/* This is a workaround for A0 LNC bug where PCI status register does /* This is a workaround for A0 LNC bug where PCI status register does
* not have new CAP bit set. can not be written by SW either. * not have new CAP bit set. can not be written by SW either.
* *
@@ -150,10 +155,7 @@ static bool type1_access_ok(unsigned int bus, unsigned int devfn, int reg)
*/ */
if (reg >= 0x100 || reg == PCI_STATUS || reg == PCI_HEADER_TYPE) if (reg >= 0x100 || reg == PCI_STATUS || reg == PCI_HEADER_TYPE)
return 0; return 0;
if (bus == 0 && (devfn == PCI_DEVFN(2, 0)
|| devfn == PCI_DEVFN(0, 0)
|| devfn == PCI_DEVFN(3, 0)))
return 1;
return 0; /* langwell on others */ return 0; /* langwell on others */
} }