1 files changed, 136 insertions, 22 deletions

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 80f843030e36..2f993a7239b4 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -29,6 +29,7 @@
 #include <linux/reset.h>
 #include <linux/pm_domain.h>
 #include <linux/pm_runtime.h>
+#include <asm/opcodes.h>
 
 #include "pcie-designware.h"
 
@@ -41,6 +42,11 @@ enum imx6_pcie_variants {
 	IMX7D,
 };
 
+struct imx6_pcie_drvdata {
+	enum imx6_pcie_variants variant;
+	int dbi_length;
+};
+
 struct imx6_pcie {
 	struct dw_pcie		*pci;
 	int			reset_gpio;
@@ -53,7 +59,6 @@ struct imx6_pcie {
 	struct reset_control	*pciephy_reset;
 	struct reset_control	*apps_reset;
 	struct reset_control	*turnoff_reset;
-	enum imx6_pcie_variants variant;
 	u32			tx_deemph_gen1;
 	u32			tx_deemph_gen2_3p5db;
 	u32			tx_deemph_gen2_6db;
@@ -66,6 +71,7 @@ struct imx6_pcie {
 	struct device		*pd_pcie;
 	/* power domain for pcie phy */
 	struct device		*pd_pcie_phy;
+	const struct imx6_pcie_drvdata *drvdata;
 };
 
 /* Parameters for the waiting for PCIe PHY PLL to lock on i.MX7 */
@@ -269,8 +275,14 @@ static int imx6q_pcie_abort_handler(unsigned long addr,
 		unsigned int fsr, struct pt_regs *regs)
 {
 	unsigned long pc = instruction_pointer(regs);
-	unsigned long instr = *(unsigned long *)pc;
-	int reg = (instr >> 12) & 15;
+	unsigned long instr;
+	int reg;
+
+	if (user_mode(regs))
+		return 1;
+
+	instr = *(unsigned long *)pc;
+	reg = (instr >> 12) & 15;
 
 	/*
 	 * If the instruction being executed was a read,
@@ -338,11 +350,64 @@ static int imx6_pcie_attach_pd(struct device *dev)
 	return 0;
 }
 
+static int imx6q_pcie_abort_handler_thumb2(unsigned long addr,
+		unsigned int fsr, struct pt_regs *regs)
+{
+	unsigned long pc = instruction_pointer(regs);
+	unsigned long instr;
+
+	if (user_mode(regs))
+		return 1;
+
+	instr = __mem_to_opcode_thumb32(*(unsigned long *)pc);
+
+	if (__opcode_is_thumb32(instr)) {
+		/* Load word/byte and halfword immediate offset */
+		if ((instr & 0xff100000UL) == 0xf8100000UL) {
+			int reg = (instr >> 12) & 0xf;
+			unsigned long val;
+
+			if ((instr & 0x00700000UL) == 0x00100000UL)
+				val = 0xff;
+			else if ((instr & 0x00700000UL) == 0x00300000UL)
+				val = 0xffff;
+			else
+				val = 0xffffffffUL;
+
+			regs->uregs[reg] = val;
+			regs->ARM_pc += 4;
+			return 0;
+		}
+	} else {
+		instr = __mem_to_opcode_thumb16(*(unsigned long *)pc);
+
+		/* Load word/byte and halfword immediate offset */
+		if (((instr & 0xe800) == 0x6800) ||
+		    ((instr & 0xf800) == 0x8800)) {
+			int reg = instr & 0x7;
+			unsigned long val;
+
+			if (instr & 0x1000)
+				val = 0xff;
+			else if (instr & 0x8000)
+				val = 0xffff;
+			else
+				val = 0xffffffffUL;
+
+			regs->uregs[reg] = val;
+			regs->ARM_pc += 2;
+			return 0;
+		}
+	}
+
+	return 1;
+}
+
 static void imx6_pcie_assert_core_reset(struct imx6_pcie *imx6_pcie)
 {
 	struct device *dev = imx6_pcie->pci->dev;
 
-	switch (imx6_pcie->variant) {
+	switch (imx6_pcie->drvdata->variant) {
 	case IMX7D:
 		reset_control_assert(imx6_pcie->pciephy_reset);
 		reset_control_assert(imx6_pcie->apps_reset);
@@ -384,7 +449,7 @@ static int imx6_pcie_enable_ref_clk(struct imx6_pcie *imx6_pcie)
 	struct device *dev = pci->dev;
 	int ret = 0;
 
-	switch (imx6_pcie->variant) {
+	switch (imx6_pcie->drvdata->variant) {
 	case IMX6SX:
 		ret = clk_prepare_enable(imx6_pcie->pcie_inbound_axi);
 		if (ret) {
@@ -487,7 +552,7 @@ static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)
 					!imx6_pcie->gpio_active_high);
 	}
 
-	switch (imx6_pcie->variant) {
+	switch (imx6_pcie->drvdata->variant) {
 	case IMX7D:
 		reset_control_deassert(imx6_pcie->pciephy_reset);
 		imx7d_pcie_wait_for_phy_pll_lock(imx6_pcie);
@@ -525,7 +590,7 @@ err_pcie_phy:
 
 static void imx6_pcie_init_phy(struct imx6_pcie *imx6_pcie)
 {
-	switch (imx6_pcie->variant) {
+	switch (imx6_pcie->drvdata->variant) {
 	case IMX7D:
 		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
 				   IMX7D_GPR12_PCIE_PHY_REFCLK_SEL, 0);
@@ -647,7 +712,7 @@ static void imx6_pcie_ltssm_enable(struct device *dev)
 {
 	struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
 
-	switch (imx6_pcie->variant) {
+	switch (imx6_pcie->drvdata->variant) {
 	case IMX6Q:
 	case IMX6SX:
 	case IMX6QP:
@@ -700,7 +765,7 @@ static int imx6_pcie_establish_link(struct imx6_pcie *imx6_pcie)
 		tmp |= PORT_LOGIC_SPEED_CHANGE;
 		dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, tmp);
 
-		if (imx6_pcie->variant != IMX7D) {
+		if (imx6_pcie->drvdata->variant != IMX7D) {
 			/*
 			 * On i.MX7, DIRECT_SPEED_CHANGE behaves differently
 			 * from i.MX6 family when no link speed transition
@@ -797,7 +862,7 @@ static void imx6_pcie_ltssm_disable(struct device *dev)
 {
 	struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
 
-	switch (imx6_pcie->variant) {
+	switch (imx6_pcie->drvdata->variant) {
 	case IMX6SX:
 	case IMX6QP:
 		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
@@ -823,7 +888,7 @@ static void imx6_pcie_pm_turnoff(struct imx6_pcie *imx6_pcie)
 	}
 
 	/* Others poke directly at IOMUXC registers */
-	switch (imx6_pcie->variant) {
+	switch (imx6_pcie->drvdata->variant) {
 	case IMX6SX:
 		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
 				IMX6SX_GPR12_PCIE_PM_TURN_OFF,
@@ -853,7 +918,7 @@ static void imx6_pcie_clk_disable(struct imx6_pcie *imx6_pcie)
 	clk_disable_unprepare(imx6_pcie->pcie_phy);
 	clk_disable_unprepare(imx6_pcie->pcie_bus);
 
-	switch (imx6_pcie->variant) {
+	switch (imx6_pcie->drvdata->variant) {
 	case IMX6SX:
 		clk_disable_unprepare(imx6_pcie->pcie_inbound_axi);
 		break;
@@ -869,8 +934,8 @@ static void imx6_pcie_clk_disable(struct imx6_pcie *imx6_pcie)
 
 static inline bool imx6_pcie_supports_suspend(struct imx6_pcie *imx6_pcie)
 {
-	return (imx6_pcie->variant == IMX7D ||
-		imx6_pcie->variant == IMX6SX);
+	return (imx6_pcie->drvdata->variant == IMX7D ||
+		imx6_pcie->drvdata->variant == IMX6SX);
 }
 
 static int imx6_pcie_suspend_noirq(struct device *dev)
@@ -936,8 +1001,7 @@ static int imx6_pcie_probe(struct platform_device *pdev)
 	pci->ops = &dw_pcie_ops;
 
 	imx6_pcie->pci = pci;
-	imx6_pcie->variant =
-		(enum imx6_pcie_variants)of_device_get_match_data(dev);
+	imx6_pcie->drvdata = of_device_get_match_data(dev);
 
 	dbi_base = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	pci->dbi_base = devm_ioremap_resource(dev, dbi_base);
@@ -981,7 +1045,7 @@ static int imx6_pcie_probe(struct platform_device *pdev)
 		return PTR_ERR(imx6_pcie->pcie);
 	}
 
-	switch (imx6_pcie->variant) {
+	switch (imx6_pcie->drvdata->variant) {
 	case IMX6SX:
 		imx6_pcie->pcie_inbound_axi = devm_clk_get(dev,
 							   "pcie_inbound_axi");
@@ -1087,11 +1151,27 @@ static void imx6_pcie_shutdown(struct platform_device *pdev)
 	imx6_pcie_assert_core_reset(imx6_pcie);
 }
 
+static const struct imx6_pcie_drvdata drvdata[] = {
+	[IMX6Q] = {
+		.variant = IMX6Q,
+		.dbi_length = 0x200,
+	},
+	[IMX6SX] = {
+		.variant = IMX6SX,
+	},
+	[IMX6QP] = {
+		.variant = IMX6QP,
+	},
+	[IMX7D] = {
+		.variant = IMX7D,
+	},
+};
+
 static const struct of_device_id imx6_pcie_of_match[] = {
-	{ .compatible = "fsl,imx6q-pcie",  .data = (void *)IMX6Q,  },
-	{ .compatible = "fsl,imx6sx-pcie", .data = (void *)IMX6SX, },
-	{ .compatible = "fsl,imx6qp-pcie", .data = (void *)IMX6QP, },
-	{ .compatible = "fsl,imx7d-pcie",  .data = (void *)IMX7D,  },
+	{ .compatible = "fsl,imx6q-pcie",  .data = &drvdata[IMX6Q],  },
+	{ .compatible = "fsl,imx6sx-pcie", .data = &drvdata[IMX6SX], },
+	{ .compatible = "fsl,imx6qp-pcie", .data = &drvdata[IMX6QP], },
+	{ .compatible = "fsl,imx7d-pcie",  .data = &drvdata[IMX7D],  },
 	{},
 };
 
@@ -1106,8 +1186,41 @@ 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)
 {
+	bool thumb2 = IS_ENABLED(CONFIG_THUMB2_KERNEL);
+
 	/*
 	 * Since probe() can be deferred we need to make sure that
 	 * hook_fault_code is not called after __init memory is freed
@@ -1115,7 +1228,8 @@ static int __init imx6_pcie_init(void)
 	 * we can install the handler here without risking it
 	 * accessing some uninitialized driver state.
 	 */
-	hook_fault_code(8, imx6q_pcie_abort_handler, SIGBUS, 0,
+	hook_fault_code(8, thumb2 ? imx6q_pcie_abort_handler_thumb2 :
+			imx6q_pcie_abort_handler, SIGBUS, 0,
 			"external abort on non-linefetch");
 
 	return platform_driver_register(&imx6_pcie_driver);