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authorPrarit Bhargava <prarit@redhat.com>2016-05-11 12:27:15 -0400
committerBjorn Helgaas <bhelgaas@google.com>2016-05-16 15:47:51 -0500
commitda77b67195de1c65bef4908fa29967c4d0af2da2 (patch)
tree2589259f523bb4df025fdd3eca7b3dfc9ca65ec0
parent92efb1bd9bcbdf83cc0e6cfead752d0c82f63677 (diff)
downloadlinux-da77b67195de1c65bef4908fa29967c4d0af2da2.tar.bz2
x86/PCI: Mark Broadwell-EP Home Agent 1 as having non-compliant BARs
Commit b894157145e4 ("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: b894157145e4 ("x86/PCI: Mark Broadwell-EP Home Agent & PCU as having non-compliant BARs") Signed-off-by: Prarit Bhargava <prarit@redhat.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: Thomas Gleixner <tglx@linutronix.de> CC: Ingo Molnar <mingo@redhat.com> CC: "H. Peter Anvin" <hpa@zytor.com> CC: Andi Kleen <ak@linux.intel.com>
-rw-r--r--arch/x86/pci/fixup.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c
index b7de1929714b..837ea36a837d 100644
--- a/arch/x86/pci/fixup.c
+++ b/arch/x86/pci/fixup.c
@@ -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);