diff options
| author | Alex Williamson <alex.williamson@redhat.com> | 2013-06-27 16:40:00 -0600 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2013-07-25 12:27:03 -0600 |
| commit | 15b100dfd1c9f7558d2fba4e3d13591dab50667f (patch) | |
| tree | f6fd4d2c6f37e48649cb606014c758332537d392 /drivers/pci | |
| parent | 83db7e0bdb70a9bb93cd000fefc3fbac3394f516 (diff) | |
| download | linux-15b100dfd1c9f7558d2fba4e3d13591dab50667f.tar.bz2 | |
PCI: Claim ACS support for AMD southbridge devices
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>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Donald Dutile <ddutile@redhat.com>
Diffstat (limited to 'drivers/pci')
| -rw-r--r-- | drivers/pci/quirks.c | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index e85d23044ae0..2e2ea2208f2e 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -3295,11 +3295,61 @@ 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 } }; |