4 files changed, 168 insertions, 130 deletions

diff --git a/drivers/pci/controller/dwc/Makefile b/drivers/pci/controller/dwc/Makefile
index eca805c1a023..9e6ce0dc2f53 100644
--- a/drivers/pci/controller/dwc/Makefile
+++ b/drivers/pci/controller/dwc/Makefile
@@ -18,6 +18,7 @@ obj-$(CONFIG_PCIE_INTEL_GW) += pcie-intel-gw.o
 obj-$(CONFIG_PCIE_KIRIN) += pcie-kirin.o
 obj-$(CONFIG_PCIE_HISI_STB) += pcie-histb.o
 obj-$(CONFIG_PCI_MESON) += pci-meson.o
+obj-$(CONFIG_PCIE_TEGRA194) += pcie-tegra194.o
 obj-$(CONFIG_PCIE_UNIPHIER) += pcie-uniphier.o
 obj-$(CONFIG_PCIE_UNIPHIER_EP) += pcie-uniphier-ep.o
 
@@ -38,6 +39,6 @@ ifdef CONFIG_ACPI
 ifdef CONFIG_PCI_QUIRKS
 obj-$(CONFIG_ARM64) += pcie-al.o
 obj-$(CONFIG_ARM64) += pcie-hisi.o
-obj-$(CONFIG_ARM64) += pcie-tegra194.o
+obj-$(CONFIG_ARM64) += pcie-tegra194-acpi.o
 endif
 endif
diff --git a/drivers/pci/controller/dwc/pcie-tegra194-acpi.c b/drivers/pci/controller/dwc/pcie-tegra194-acpi.c
new file mode 100644
index 000000000000..c2de6ed4d86f
--- /dev/null
+++ b/drivers/pci/controller/dwc/pcie-tegra194-acpi.c
@@ -0,0 +1,108 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * ACPI quirks for Tegra194 PCIe host controller
+ *
+ * Copyright (C) 2021 NVIDIA Corporation.
+ *
+ * Author: Vidya Sagar <vidyas@nvidia.com>
+ */
+
+#include <linux/pci.h>
+#include <linux/pci-acpi.h>
+#include <linux/pci-ecam.h>
+
+#include "pcie-designware.h"
+
+struct tegra194_pcie_ecam  {
+	void __iomem *config_base;
+	void __iomem *iatu_base;
+	void __iomem *dbi_base;
+};
+
+static int tegra194_acpi_init(struct pci_config_window *cfg)
+{
+	struct device *dev = cfg->parent;
+	struct tegra194_pcie_ecam *pcie_ecam;
+
+	pcie_ecam = devm_kzalloc(dev, sizeof(*pcie_ecam), GFP_KERNEL);
+	if (!pcie_ecam)
+		return -ENOMEM;
+
+	pcie_ecam->config_base = cfg->win;
+	pcie_ecam->iatu_base = cfg->win + SZ_256K;
+	pcie_ecam->dbi_base = cfg->win + SZ_512K;
+	cfg->priv = pcie_ecam;
+
+	return 0;
+}
+
+static void atu_reg_write(struct tegra194_pcie_ecam *pcie_ecam, int index,
+			  u32 val, u32 reg)
+{
+	u32 offset = PCIE_GET_ATU_OUTB_UNR_REG_OFFSET(index);
+
+	writel(val, pcie_ecam->iatu_base + offset + reg);
+}
+
+static void program_outbound_atu(struct tegra194_pcie_ecam *pcie_ecam,
+				 int index, int type, u64 cpu_addr,
+				 u64 pci_addr, u64 size)
+{
+	atu_reg_write(pcie_ecam, index, lower_32_bits(cpu_addr),
+		      PCIE_ATU_LOWER_BASE);
+	atu_reg_write(pcie_ecam, index, upper_32_bits(cpu_addr),
+		      PCIE_ATU_UPPER_BASE);
+	atu_reg_write(pcie_ecam, index, lower_32_bits(pci_addr),
+		      PCIE_ATU_LOWER_TARGET);
+	atu_reg_write(pcie_ecam, index, lower_32_bits(cpu_addr + size - 1),
+		      PCIE_ATU_LIMIT);
+	atu_reg_write(pcie_ecam, index, upper_32_bits(pci_addr),
+		      PCIE_ATU_UPPER_TARGET);
+	atu_reg_write(pcie_ecam, index, type, PCIE_ATU_CR1);
+	atu_reg_write(pcie_ecam, index, PCIE_ATU_ENABLE, PCIE_ATU_CR2);
+}
+
+static void __iomem *tegra194_map_bus(struct pci_bus *bus,
+				      unsigned int devfn, int where)
+{
+	struct pci_config_window *cfg = bus->sysdata;
+	struct tegra194_pcie_ecam *pcie_ecam = cfg->priv;
+	u32 busdev;
+	int type;
+
+	if (bus->number < cfg->busr.start || bus->number > cfg->busr.end)
+		return NULL;
+
+	if (bus->number == cfg->busr.start) {
+		if (PCI_SLOT(devfn) == 0)
+			return pcie_ecam->dbi_base + where;
+		else
+			return NULL;
+	}
+
+	busdev = PCIE_ATU_BUS(bus->number) | PCIE_ATU_DEV(PCI_SLOT(devfn)) |
+		 PCIE_ATU_FUNC(PCI_FUNC(devfn));
+
+	if (bus->parent->number == cfg->busr.start) {
+		if (PCI_SLOT(devfn) == 0)
+			type = PCIE_ATU_TYPE_CFG0;
+		else
+			return NULL;
+	} else {
+		type = PCIE_ATU_TYPE_CFG1;
+	}
+
+	program_outbound_atu(pcie_ecam, 0, type, cfg->res.start, busdev,
+			     SZ_256K);
+
+	return pcie_ecam->config_base + where;
+}
+
+const struct pci_ecam_ops tegra194_pcie_ops = {
+	.init		= tegra194_acpi_init,
+	.pci_ops	= {
+		.map_bus	= tegra194_map_bus,
+		.read		= pci_generic_config_read,
+		.write		= pci_generic_config_write,
+	}
+};
diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index bafd2c6ab3c2..504669e3afe0 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -22,8 +22,6 @@
 #include <linux/of_irq.h>
 #include <linux/of_pci.h>
 #include <linux/pci.h>
-#include <linux/pci-acpi.h>
-#include <linux/pci-ecam.h>
 #include <linux/phy/phy.h>
 #include <linux/pinctrl/consumer.h>
 #include <linux/platform_device.h>
@@ -247,24 +245,6 @@ static const unsigned int pcie_gen_freq[] = {
 	GEN4_CORE_CLK_FREQ
 };
 
-static const u32 event_cntr_ctrl_offset[] = {
-	0x1d8,
-	0x1a8,
-	0x1a8,
-	0x1a8,
-	0x1c4,
-	0x1d8
-};
-
-static const u32 event_cntr_data_offset[] = {
-	0x1dc,
-	0x1ac,
-	0x1ac,
-	0x1ac,
-	0x1c8,
-	0x1dc
-};
-
 struct tegra_pcie_dw {
 	struct device *dev;
 	struct resource *appl_res;
@@ -313,104 +293,6 @@ struct tegra_pcie_dw_of_data {
 	enum dw_pcie_device_mode mode;
 };
 
-#if defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS)
-struct tegra194_pcie_ecam  {
-	void __iomem *config_base;
-	void __iomem *iatu_base;
-	void __iomem *dbi_base;
-};
-
-static int tegra194_acpi_init(struct pci_config_window *cfg)
-{
-	struct device *dev = cfg->parent;
-	struct tegra194_pcie_ecam *pcie_ecam;
-
-	pcie_ecam = devm_kzalloc(dev, sizeof(*pcie_ecam), GFP_KERNEL);
-	if (!pcie_ecam)
-		return -ENOMEM;
-
-	pcie_ecam->config_base = cfg->win;
-	pcie_ecam->iatu_base = cfg->win + SZ_256K;
-	pcie_ecam->dbi_base = cfg->win + SZ_512K;
-	cfg->priv = pcie_ecam;
-
-	return 0;
-}
-
-static void atu_reg_write(struct tegra194_pcie_ecam *pcie_ecam, int index,
-			  u32 val, u32 reg)
-{
-	u32 offset = PCIE_GET_ATU_OUTB_UNR_REG_OFFSET(index);
-
-	writel(val, pcie_ecam->iatu_base + offset + reg);
-}
-
-static void program_outbound_atu(struct tegra194_pcie_ecam *pcie_ecam,
-				 int index, int type, u64 cpu_addr,
-				 u64 pci_addr, u64 size)
-{
-	atu_reg_write(pcie_ecam, index, lower_32_bits(cpu_addr),
-		      PCIE_ATU_LOWER_BASE);
-	atu_reg_write(pcie_ecam, index, upper_32_bits(cpu_addr),
-		      PCIE_ATU_UPPER_BASE);
-	atu_reg_write(pcie_ecam, index, lower_32_bits(pci_addr),
-		      PCIE_ATU_LOWER_TARGET);
-	atu_reg_write(pcie_ecam, index, lower_32_bits(cpu_addr + size - 1),
-		      PCIE_ATU_LIMIT);
-	atu_reg_write(pcie_ecam, index, upper_32_bits(pci_addr),
-		      PCIE_ATU_UPPER_TARGET);
-	atu_reg_write(pcie_ecam, index, type, PCIE_ATU_CR1);
-	atu_reg_write(pcie_ecam, index, PCIE_ATU_ENABLE, PCIE_ATU_CR2);
-}
-
-static void __iomem *tegra194_map_bus(struct pci_bus *bus,
-				      unsigned int devfn, int where)
-{
-	struct pci_config_window *cfg = bus->sysdata;
-	struct tegra194_pcie_ecam *pcie_ecam = cfg->priv;
-	u32 busdev;
-	int type;
-
-	if (bus->number < cfg->busr.start || bus->number > cfg->busr.end)
-		return NULL;
-
-	if (bus->number == cfg->busr.start) {
-		if (PCI_SLOT(devfn) == 0)
-			return pcie_ecam->dbi_base + where;
-		else
-			return NULL;
-	}
-
-	busdev = PCIE_ATU_BUS(bus->number) | PCIE_ATU_DEV(PCI_SLOT(devfn)) |
-		 PCIE_ATU_FUNC(PCI_FUNC(devfn));
-
-	if (bus->parent->number == cfg->busr.start) {
-		if (PCI_SLOT(devfn) == 0)
-			type = PCIE_ATU_TYPE_CFG0;
-		else
-			return NULL;
-	} else {
-		type = PCIE_ATU_TYPE_CFG1;
-	}
-
-	program_outbound_atu(pcie_ecam, 0, type, cfg->res.start, busdev,
-			     SZ_256K);
-
-	return pcie_ecam->config_base + where;
-}
-
-const struct pci_ecam_ops tegra194_pcie_ops = {
-	.init		= tegra194_acpi_init,
-	.pci_ops	= {
-		.map_bus	= tegra194_map_bus,
-		.read		= pci_generic_config_read,
-		.write		= pci_generic_config_write,
-	}
-};
-#endif /* defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS) */
-
-#ifdef CONFIG_PCIE_TEGRA194
-
 static inline struct tegra_pcie_dw *to_tegra_pcie(struct dw_pcie *pci)
 {
 	return container_of(pci, struct tegra_pcie_dw, pci);
@@ -694,6 +576,24 @@ static struct pci_ops tegra_pci_ops = {
 };
 
 #if defined(CONFIG_PCIEASPM)
+static const u32 event_cntr_ctrl_offset[] = {
+	0x1d8,
+	0x1a8,
+	0x1a8,
+	0x1a8,
+	0x1c4,
+	0x1d8
+};
+
+static const u32 event_cntr_data_offset[] = {
+	0x1dc,
+	0x1ac,
+	0x1ac,
+	0x1ac,
+	0x1c8,
+	0x1dc
+};
+
 static void disable_aspm_l11(struct tegra_pcie_dw *pcie)
 {
 	u32 val;
@@ -2411,5 +2311,3 @@ MODULE_DEVICE_TABLE(of, tegra_pcie_dw_of_match);
 MODULE_AUTHOR("Vidya Sagar <vidyas@nvidia.com>");
 MODULE_DESCRIPTION("NVIDIA PCIe host controller driver");
 MODULE_LICENSE("GPL v2");
-
-#endif /* CONFIG_PCIE_TEGRA194 */
diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c
index 051b48bd7985..e3f5e7ab7606 100644
--- a/drivers/pci/controller/pci-aardvark.c
+++ b/drivers/pci/controller/pci-aardvark.c
@@ -514,7 +514,7 @@ static int advk_pcie_wait_pio(struct advk_pcie *pcie)
 		udelay(PIO_RETRY_DELAY);
 	}
 
-	dev_err(dev, "config read/write timed out\n");
+	dev_err(dev, "PIO read/write transfer time out\n");
 	return -ETIMEDOUT;
 }
 
@@ -657,6 +657,35 @@ static bool advk_pcie_valid_device(struct advk_pcie *pcie, struct pci_bus *bus,
 	return true;
 }
 
+static bool advk_pcie_pio_is_running(struct advk_pcie *pcie)
+{
+	struct device *dev = &pcie->pdev->dev;
+
+	/*
+	 * Trying to start a new PIO transfer when previous has not completed
+	 * cause External Abort on CPU which results in kernel panic:
+	 *
+	 *     SError Interrupt on CPU0, code 0xbf000002 -- SError
+	 *     Kernel panic - not syncing: Asynchronous SError Interrupt
+	 *
+	 * Functions advk_pcie_rd_conf() and advk_pcie_wr_conf() are protected
+	 * by raw_spin_lock_irqsave() at pci_lock_config() level to prevent
+	 * concurrent calls at the same time. But because PIO transfer may take
+	 * about 1.5s when link is down or card is disconnected, it means that
+	 * advk_pcie_wait_pio() does not always have to wait for completion.
+	 *
+	 * Some versions of ARM Trusted Firmware handles this External Abort at
+	 * EL3 level and mask it to prevent kernel panic. Relevant TF-A commit:
+	 * https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/commit/?id=3c7dcdac5c50
+	 */
+	if (advk_readl(pcie, PIO_START)) {
+		dev_err(dev, "Previous PIO read/write transfer is still running\n");
+		return true;
+	}
+
+	return false;
+}
+
 static int advk_pcie_rd_conf(struct pci_bus *bus, u32 devfn,
 			     int where, int size, u32 *val)
 {
@@ -673,9 +702,10 @@ static int advk_pcie_rd_conf(struct pci_bus *bus, u32 devfn,
 		return pci_bridge_emul_conf_read(&pcie->bridge, where,
 						 size, val);
 
-	/* Start PIO */
-	advk_writel(pcie, 0, PIO_START);
-	advk_writel(pcie, 1, PIO_ISR);
+	if (advk_pcie_pio_is_running(pcie)) {
+		*val = 0xffffffff;
+		return PCIBIOS_SET_FAILED;
+	}
 
 	/* Program the control register */
 	reg = advk_readl(pcie, PIO_CTRL);
@@ -694,7 +724,8 @@ static int advk_pcie_rd_conf(struct pci_bus *bus, u32 devfn,
 	/* Program the data strobe */
 	advk_writel(pcie, 0xf, PIO_WR_DATA_STRB);
 
-	/* Start the transfer */
+	/* Clear PIO DONE ISR and start the transfer */
+	advk_writel(pcie, 1, PIO_ISR);
 	advk_writel(pcie, 1, PIO_START);
 
 	ret = advk_pcie_wait_pio(pcie);
@@ -734,9 +765,8 @@ static int advk_pcie_wr_conf(struct pci_bus *bus, u32 devfn,
 	if (where % size)
 		return PCIBIOS_SET_FAILED;
 
-	/* Start PIO */
-	advk_writel(pcie, 0, PIO_START);
-	advk_writel(pcie, 1, PIO_ISR);
+	if (advk_pcie_pio_is_running(pcie))
+		return PCIBIOS_SET_FAILED;
 
 	/* Program the control register */
 	reg = advk_readl(pcie, PIO_CTRL);
@@ -763,7 +793,8 @@ static int advk_pcie_wr_conf(struct pci_bus *bus, u32 devfn,
 	/* Program the data strobe */
 	advk_writel(pcie, data_strobe, PIO_WR_DATA_STRB);
 
-	/* Start the transfer */
+	/* Clear PIO DONE ISR and start the transfer */
+	advk_writel(pcie, 1, PIO_ISR);
 	advk_writel(pcie, 1, PIO_START);
 
 	ret = advk_pcie_wait_pio(pcie);