@@ -3270,11 +3270,61 @@ struct pci_dev *pci_get_dma_source(struct pci_dev *dev)
return pci_dev_get(dev);
}
+/*
+ * AMD has indicated that the devices below do not support peer-to-peer
+ * in any system where they are found in the southbridge with an AMD
+ * IOMMU in the system. Multifunction devices that do not support
+ * peer-to-peer between functions can claim to support a subset of ACS.
+ * Such devices effectively enable request redirect (RR) and completion
+ * redirect (CR) since all transactions are redirected to the upstream
+ * root complex.
+ *
+ * http://permalink.gmane.org/gmane.comp.emulators.kvm.devel/94086
+ * http://permalink.gmane.org/gmane.comp.emulators.kvm.devel/94102
+ * http://permalink.gmane.org/gmane.comp.emulators.kvm.devel/99402
+ *
+ * 1002:4385 SBx00 SMBus Controller
+ * 1002:439c SB7x0/SB8x0/SB9x0 IDE Controller
+ * 1002:4383 SBx00 Azalia (Intel HDA)
+ * 1002:439d SB7x0/SB8x0/SB9x0 LPC host controller
+ * 1002:4384 SBx00 PCI to PCI Bridge
+ * 1002:4399 SB7x0/SB8x0/SB9x0 USB OHCI2 Controller
+ */
+static int pci_quirk_amd_sb_acs(struct pci_dev *dev, u16 acs_flags)
+{
+#ifdef CONFIG_ACPI
+ struct acpi_table_header *header = NULL;
+ acpi_status status;
+
+ /* Targeting multifunction devices on the SB (appears on root bus) */
+ if (!dev->multifunction || !pci_is_root_bus(dev->bus))
+ return -ENODEV;
+
+ /* The IVRS table describes the AMD IOMMU */
+ status = acpi_get_table("IVRS", 0, &header);
+ if (ACPI_FAILURE(status))
+ return -ENODEV;
+
+ /* Filter out flags not applicable to multifunction */
+ acs_flags &= (PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_EC | PCI_ACS_DT);
+
+ return acs_flags & ~(PCI_ACS_RR | PCI_ACS_CR) ? 0 : 1;
+#else
+ return -ENODEV;
+#endif
+}
+
static const struct pci_dev_acs_enabled {
u16 vendor;
u16 device;
int (*acs_enabled)(struct pci_dev *dev, u16 acs_flags);
} pci_dev_acs_enabled[] = {
+ { PCI_VENDOR_ID_ATI, 0x4385, pci_quirk_amd_sb_acs },
+ { PCI_VENDOR_ID_ATI, 0x439c, pci_quirk_amd_sb_acs },
+ { PCI_VENDOR_ID_ATI, 0x4383, pci_quirk_amd_sb_acs },
+ { PCI_VENDOR_ID_ATI, 0x439d, pci_quirk_amd_sb_acs },
+ { PCI_VENDOR_ID_ATI, 0x4384, pci_quirk_amd_sb_acs },
+ { PCI_VENDOR_ID_ATI, 0x4399, pci_quirk_amd_sb_acs },
{ 0 }
};
AMD confirmed that peer-to-peer between these devices is not possible. We can therefore claim that they support a subset of ACS. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> --- drivers/pci/quirks.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html