Many Zhaoxin Root Ports and Switch Downstream Ports do provide ACS-like
capability but have no ACS Capability Structure. Peer-to-Peer
transactions could be blocked between these ports, so add quirk
to make devices behind them could be assigned to different IOMMU group.
Signed-off-by: Raymond Pang <RaymondPang-oc@xxxxxxxxxxx>
---
drivers/pci/quirks.c | 26 ++++++++++++++++++++++++++
1 file changed, 26 insertions(+)
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 3f06496a3d4c..49cf6e943f16 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -4464,6 +4464,30 @@ static int pci_quirk_xgene_acs(struct pci_dev *dev, u16 acs_flags)
return pci_acs_ctrl_enabled(acs_flags,
PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF);
}
+
+/*
+ * Many Zhaoxin Root Ports and Switch Downstream Ports have no ACS capability.
+ * But the implementation could block peer-to-peer transactions between them
+ * and provide ACS-like functionality.
+ */
+static int pci_quirk_zhaoxin_pcie_ports_acs(struct pci_dev *dev, u16 acs_flags)
+{
+
+ if (!pci_is_pcie(dev) ||
+ ((pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT) &&
+ (pci_pcie_type(dev) != PCI_EXP_TYPE_DOWNSTREAM)))
+ return -ENOTTY;
+
+ switch (dev->device) {
+ case 0x0710 ... 0x071e:
+ case 0x0721:
+ case 0x0723 ... 0x0732:
+ return pci_acs_ctrl_enabled(acs_flags,
+ PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF);
+ }
+
+ return false;
+}
/*
* Many Intel PCH Root Ports do provide ACS-like features to disable peer
@@ -4771,6 +4795,8 @@ static const struct pci_dev_acs_enabled {
{ PCI_VENDOR_ID_ZHAOXIN, 0x3038, pci_quirk_mf_endpoint_acs },
{ PCI_VENDOR_ID_ZHAOXIN, 0x3104, pci_quirk_mf_endpoint_acs },
{ PCI_VENDOR_ID_ZHAOXIN, 0x9083, pci_quirk_mf_endpoint_acs },
+ /* Zhaoxin Root/Downstream Ports */
+ { PCI_VENDOR_ID_ZHAOXIN, PCI_ANY_ID, pci_quirk_zhaoxin_pcie_ports_acs },
{ 0 }
};
--
2.26.0
