From: Casey Leedom <leedom@xxxxxxxxxxx>
The new flag PCI_DEV_FLAGS_NO_RELAXED_ORDERING indicates that the Relaxed
Ordering Attribute should not be used on Transaction Layer Packets destined
for the PCIe End Node so flagged. Initially flagged this way are Intel
E5-26xx Root Complex Ports which suffer from a Flow Control Credit
Performance Problem and AMD A1100 ARM ("SEATTLE") Root Complex Ports which
don't obey PCIe 3.0 ordering rules which can lead to Data Corruption.
Signed-off-by: Casey Leedom <leedom@xxxxxxxxxxx>
Signed-off-by: Ding Tianhong <dingtianhong@xxxxxxxxxx>
---
drivers/pci/quirks.c | 38 ++++++++++++++++++++++++++++++++++++++
include/linux/pci.h | 2 ++
2 files changed, 40 insertions(+)
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 085fb78..58bdd23 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -3999,6 +3999,44 @@ static void quirk_tw686x_class(struct pci_dev *pdev)
quirk_tw686x_class);
/*
+ * Some devices have problems with Transaction Layer Packets with the Relaxed
+ * Ordering Attribute set. Such devices should mark themselves and other
+ * Device Drivers should check before sending TLPs with RO set.
+ */
+static void quirk_relaxedordering_disable(struct pci_dev *dev)
+{
+ dev->dev_flags |= PCI_DEV_FLAGS_NO_RELAXED_ORDERING;
+}
+
+/*
+ * Intel E5-26xx Root Complex has a Flow Control Credit issue which can
+ * cause performance problems with Upstream Transaction Layer Packets with
+ * Relaxed Ordering set.
+ */
+DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_INTEL, 0x6f02, PCI_CLASS_NOT_DEFINED, 8,
+ quirk_relaxedordering_disable);
+DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_INTEL, 0x6f04, PCI_CLASS_NOT_DEFINED, 8,
+ quirk_relaxedordering_disable);
+DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_INTEL, 0x6f08, PCI_CLASS_NOT_DEFINED, 8,
+ quirk_relaxedordering_disable);
+
+/*
+ * The AMD ARM A1100 (AKA "SEATTLE") SoC has a bug in its PCIe Root Complex
+ * where Upstream Transaction Layer Packets with the Relaxed Ordering
+ * Attribute clear are allowed to bypass earlier TLPs with Relaxed Ordering
+ * set. This is a violation of the PCIe 3.0 Transaction Ordering Rules
+ * outlined in Section 2.4.1 (PCI Express(r) Base Specification Revision 3.0
+ * November 10, 2010). As a result, on this platform we can't use Relaxed
+ * Ordering for Upstream TLPs.
+ */
+DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_AMD, 0x1a00, PCI_CLASS_NOT_DEFINED, 8,
+ quirk_relaxedordering_disable);
+DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_AMD, 0x1a01, PCI_CLASS_NOT_DEFINED, 8,
+ quirk_relaxedordering_disable);
+DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_AMD, 0x1a02, PCI_CLASS_NOT_DEFINED, 8,
+ quirk_relaxedordering_disable);
+
+/*
* Per PCIe r3.0, sec 2.2.9, "Completion headers must supply the same
* values for the Attribute as were supplied in the header of the
* corresponding Request, except as explicitly allowed when IDO is used."
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 8039f9f..ce77690 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -188,6 +188,8 @@ enum pci_dev_flags {
* the direct_complete optimization.
*/
PCI_DEV_FLAGS_NEEDS_RESUME = (__force pci_dev_flags_t) (1 << 11),
+ /* Don't use Relaxed Ordering for TLPs directed at this device */
+ PCI_DEV_FLAGS_NO_RELAXED_ORDERING = (__force pci_dev_flags_t) (1 << 12),
};
enum pci_irq_reroute_variant {
--
1.9.0
