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@xxxxxxxxxx> --- drivers/pci/quirks.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index 7d68aee..02855dd 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -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 } }; -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
