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x86/PCI: Mark Broadwell-EP Home Agent 1 as having non-compliant BARs
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Commit b894157 ("x86/PCI: Mark Broadwell-EP Home Agent & PCU as having
non-compliant BARs") marked Home Agent 0 & PCU has having non-compliant
BARs.  Home Agent 1 also has non-compliant BARs.

Mark Home Agent 1 as having non-compliant BARs so the PCI core doesn't
touch them.

The problem with these devices is documented in the Xeon v4 specification
update:

  BDF2          PCI BARs in the Home Agent Will Return Non-Zero Values
                During Enumeration

  Problem:      During system initialization the Operating System may access
                the standard PCI BARs (Base Address Registers).  Due to
                this erratum, accesses to the Home Agent BAR registers (Bus
                1; Device 18; Function 0,4; Offsets (0x14-0x24) will return
                non-zero values.

  Implication:  The operating system may issue a warning.  Intel has not
                observed any functional failures due to this erratum.

Link: http://www.intel.com/content/www/us/en/processors/xeon/xeon-e5-v4-spec-update.html
Fixes: b894157 ("x86/PCI: Mark Broadwell-EP Home Agent & PCU as having non-compliant BARs")
Signed-off-by: Prarit Bhargava <[email protected]>
Signed-off-by: Bjorn Helgaas <[email protected]>
CC: Thomas Gleixner <[email protected]>
CC: Ingo Molnar <[email protected]>
CC: "H. Peter Anvin" <[email protected]>
CC: Andi Kleen <[email protected]>
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prarit authored and bjorn-helgaas committed May 16, 2016
1 parent 92efb1b commit da77b67
Showing 1 changed file with 7 additions and 0 deletions.
7 changes: 7 additions & 0 deletions arch/x86/pci/fixup.c
Original file line number Diff line number Diff line change
Expand Up @@ -552,9 +552,16 @@ static void twinhead_reserve_killing_zone(struct pci_dev *dev)
}
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x27B9, twinhead_reserve_killing_zone);

/*
* Broadwell EP Home Agent BARs erroneously return non-zero values when read.
*
* See http://www.intel.com/content/www/us/en/processors/xeon/xeon-e5-v4-spec-update.html
* entry BDF2.
*/
static void pci_bdwep_bar(struct pci_dev *dev)
{
dev->non_compliant_bars = 1;
}
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6f60, pci_bdwep_bar);
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6fa0, pci_bdwep_bar);
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6fc0, pci_bdwep_bar);

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