PCI: Add quirk for known incorrect MPSS

Using legacy interrupts and TLPs > 256 bytes on the SFC4000 (all
revisions) may cause interrupt messages to be replayed.  In some
systems this results in a non-recoverable MCE.  Early boards using the
SFC4000 set the maximum payload size supported (MPSS) to 1024 bytes
and we should override that.

There are probably other devices with similar issues, so give this
quirk a generic name.
Signed-off-by: NBen Hutchings <bhutchings@solarflare.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

drivers/pci/quirks.c

@@ -2822,6 +2822,20 @@ static void __devinit fixup_ti816x_class(struct pci_dev* dev)
 }
 DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_TI, 0xb800, fixup_ti816x_class);
 
+/* Some PCIe devices do not work reliably with the claimed maximum
+ * payload size supported.
+ */
+static void __devinit fixup_mpss_256(struct pci_dev *dev)
+{
+	dev->pcie_mpss = 1; /* 256 bytes */
+}
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_SOLARFLARE,
+			 PCI_DEVICE_ID_SOLARFLARE_SFC4000A_0, fixup_mpss_256);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_SOLARFLARE,
+			 PCI_DEVICE_ID_SOLARFLARE_SFC4000A_1, fixup_mpss_256);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_SOLARFLARE,
+			 PCI_DEVICE_ID_SOLARFLARE_SFC4000B, fixup_mpss_256);
+
 static void pci_do_fixups(struct pci_dev *dev, struct pci_fixup *f,
 			  struct pci_fixup *end)
 {