PCI: layerscape: Fix MSG TLP drop setting

Some kinds of Layerscape PCIe controllers will forward the received message
TLPs to system application address space, which could corrupt system memory
or lead to a system hang.  Enable MSG_DROP to fix this issue.

Signed-off-by: Minghuan Lian <Minghuan.Lian@nxp.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/host/pci-layerscape.c

@@ -77,6 +77,16 @@ static void ls_pcie_fix_class(struct ls_pcie *pcie)
 	iowrite16(PCI_CLASS_BRIDGE_PCI, pcie->dbi + PCI_CLASS_DEVICE);
 }
 
+/* Drop MSG TLP except for Vendor MSG */
+static void ls_pcie_drop_msg_tlp(struct ls_pcie *pcie)
+{
+	u32 val;
+
+	val = ioread32(pcie->dbi + PCIE_STRFMR1);
+	val &= 0xDFFFFFFF;
+	iowrite32(val, pcie->dbi + PCIE_STRFMR1);
+}
+
 static int ls1021_pcie_link_up(struct pcie_port *pp)
 {
 	u32 state;
@@ -97,7 +107,7 @@ static int ls1021_pcie_link_up(struct pcie_port *pp)
 static void ls1021_pcie_host_init(struct pcie_port *pp)
 {
 	struct ls_pcie *pcie = to_ls_pcie(pp);
-	u32 val, index[2];
+	u32 index[2];
 
 	pcie->scfg = syscon_regmap_lookup_by_phandle(pp->dev->of_node,
 						     "fsl,pcie-scfg");
@@ -116,13 +126,7 @@ static void ls1021_pcie_host_init(struct pcie_port *pp)
 
 	dw_pcie_setup_rc(pp);
 
-	/*
-	 * LS1021A Workaround for internal TKT228622
-	 * to fix the INTx hang issue
-	 */
-	val = ioread32(pcie->dbi + PCIE_STRFMR1);
-	val &= 0xffff;
-	iowrite32(val, pcie->dbi + PCIE_STRFMR1);
+	ls_pcie_drop_msg_tlp(pcie);
 }
 
 static int ls_pcie_link_up(struct pcie_port *pp)
@@ -147,6 +151,7 @@ static void ls_pcie_host_init(struct pcie_port *pp)
 	iowrite32(1, pcie->dbi + PCIE_DBI_RO_WR_EN);
 	ls_pcie_fix_class(pcie);
 	ls_pcie_clear_multifunction(pcie);
+	ls_pcie_drop_msg_tlp(pcie);
 	iowrite32(0, pcie->dbi + PCIE_DBI_RO_WR_EN);
 }