diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 6ddb5b50a14ae389d138f1044e5dd0441e59b297..39e91a7b1dd9d29e2f75c8f42b5ab5fbbacef445 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -5071,6 +5071,22 @@ static int  pci_quirk_wangxun_nic_acs(struct pci_dev *dev, u16 acs_flags)
 	return false;
 }
 
+/*
+ * Phytium 5000E SOC have no ACS capability, and on multi-function
+ * devices, peer-to-peer transactions are not be used between the functions.
+ * So add an ACS quirk for below devices to isolate functions.
+ */
+static int  pci_quirk_phytium_pcie_ports_acs(struct pci_dev *dev, u16 acs_flags)
+{
+       switch (dev->device) {
+       case 0x0100:
+               return pci_acs_ctrl_enabled(acs_flags,
+                       PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF);
+       }
+
+       return false;
+}
+
 static const struct pci_dev_acs_enabled {
 	u16 vendor;
 	u16 device;
@@ -5242,6 +5258,8 @@ static const struct pci_dev_acs_enabled {
 	{ PCI_VENDOR_ID_ZHAOXIN, PCI_ANY_ID, pci_quirk_zhaoxin_pcie_ports_acs },
 	/* Wangxun nics */
 	{ PCI_VENDOR_ID_WANGXUN, PCI_ANY_ID, pci_quirk_wangxun_nic_acs },
+	/* Phytium Socs */
+	{ PCI_VENDOR_ID_PHYTIUM, PCI_ANY_ID, pci_quirk_phytium_pcie_ports_acs },
 	{ 0 }
 };