Merge branch 'remotes/lorenzo/pci/imx'

  - Reduce i.MX 6Quad DBI register length to avoid aborts from accessing
    invalid registers (Stefan Agner)

* remotes/lorenzo/pci/imx:
  PCI: imx6: Limit DBI register length

1 files changed, 33 insertions, 0 deletions

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 9b5cb5b70389..8b8efa3063f5 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -57,6 +57,7 @@ enum imx6_pcie_variants {
 struct imx6_pcie_drvdata {
 	enum imx6_pcie_variants variant;
 	u32 flags;
+	int dbi_length;
 };
 
 struct imx6_pcie {
@@ -1212,6 +1213,7 @@ static const struct imx6_pcie_drvdata drvdata[] = {
 		.variant = IMX6Q,
 		.flags = IMX6_PCIE_FLAG_IMX6_PHY |
 			 IMX6_PCIE_FLAG_IMX6_SPEED_CHANGE,
+		.dbi_length = 0x200,
 	},
 	[IMX6SX] = {
 		.variant = IMX6SX,
@@ -1254,6 +1256,37 @@ static struct platform_driver imx6_pcie_driver = {
 	.shutdown = imx6_pcie_shutdown,
 };
 
+static void imx6_pcie_quirk(struct pci_dev *dev)
+{
+	struct pci_bus *bus = dev->bus;
+	struct pcie_port *pp = bus->sysdata;
+
+	/* Bus parent is the PCI bridge, its parent is this platform driver */
+	if (!bus->dev.parent || !bus->dev.parent->parent)
+		return;
+
+	/* Make sure we only quirk devices associated with this driver */
+	if (bus->dev.parent->parent->driver != &imx6_pcie_driver.driver)
+		return;
+
+	if (bus->number == pp->root_bus_nr) {
+		struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+		struct imx6_pcie *imx6_pcie = to_imx6_pcie(pci);
+
+		/*
+		 * Limit config length to avoid the kernel reading beyond
+		 * the register set and causing an abort on i.MX 6Quad
+		 */
+		if (imx6_pcie->drvdata->dbi_length) {
+			dev->cfg_size = imx6_pcie->drvdata->dbi_length;
+			dev_info(&dev->dev, "Limiting cfg_size to %d\n",
+					dev->cfg_size);
+		}
+	}
+}
+DECLARE_PCI_FIXUP_CLASS_HEADER(PCI_VENDOR_ID_SYNOPSYS, 0xabcd,
+			PCI_CLASS_BRIDGE_PCI, 8, imx6_pcie_quirk);
+
 static int __init imx6_pcie_init(void)
 {
 #ifdef CONFIG_ARM