[PATCH v11 3/3] PCI: uniphier: Add misc interrupt handler to invoke PME and AER

[Kunihiko Hayashi <hayashi.kunihiko@socionext.com>]

This patch adds misc interrupt handler to detect and invoke PME/AER event.

In UniPhier PCIe controller, PME/AER signals are assigned to the same
signal as MSI by the internal logic. These signals should be detected by
the internal register, however, DWC MSI handler can't handle these signals.

DWC MSI handler calls .msi_host_isr() callback function, that detects
PME/AER signals using the internal register and invokes the interrupt
with PME/AER IRQ numbers.

These IRQ numbers is obtained by uniphier_pcie_port_get_irq() function,
that finds the device that matches PME/AER from the devices associated
with Root Port, and returns its IRQ number.

Cc: Marc Zyngier <maz@kernel.org>
Cc: Jingoo Han <jingoohan1@gmail.com>
Cc: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 drivers/pci/controller/dwc/pcie-uniphier.c | 105 +++++++++++++++++++++++++----
 1 file changed, 91 insertions(+), 14 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-uniphier.c b/drivers/pci/controller/dwc/pcie-uniphier.c
index 7e8bad3..dcd8fa8 100644
--- a/drivers/pci/controller/dwc/pcie-uniphier.c
+++ b/drivers/pci/controller/dwc/pcie-uniphier.c
@@ -21,6 +21,7 @@
 #include <linux/reset.h>
 
 #include "pcie-designware.h"
+#include "../../pcie/portdrv.h"
 
 #define PCL_PINCTRL0			0x002c
 #define PCL_PERST_PLDN_REGEN		BIT(12)
@@ -44,7 +45,9 @@
 #define PCL_SYS_AUX_PWR_DET		BIT(8)
 
 #define PCL_RCV_INT			0x8108
+#define PCL_RCV_INT_ALL_INT_MASK	GENMASK(28, 25)
 #define PCL_RCV_INT_ALL_ENABLE		GENMASK(20, 17)
+#define PCL_RCV_INT_ALL_MSI_MASK	GENMASK(12, 9)
 #define PCL_CFG_BW_MGT_STATUS		BIT(4)
 #define PCL_CFG_LINK_AUTO_BW_STATUS	BIT(3)
 #define PCL_CFG_AER_RC_ERR_MSI_STATUS	BIT(2)
@@ -68,6 +71,8 @@ struct uniphier_pcie_priv {
 	struct reset_control *rst;
 	struct phy *phy;
 	struct irq_domain *legacy_irq_domain;
+	int aer_irq;
+	int pme_irq;
 };
 
 #define to_uniphier_pcie(x)	dev_get_drvdata((x)->dev)
@@ -164,7 +169,15 @@ static void uniphier_pcie_stop_link(struct dw_pcie *pci)
 
 static void uniphier_pcie_irq_enable(struct uniphier_pcie_priv *priv)
 {
-	writel(PCL_RCV_INT_ALL_ENABLE, priv->base + PCL_RCV_INT);
+	u32 val;
+
+	val = PCL_RCV_INT_ALL_ENABLE;
+	if (pci_msi_enabled())
+		val |= PCL_RCV_INT_ALL_INT_MASK;
+	else
+		val |= PCL_RCV_INT_ALL_MSI_MASK;
+
+	writel(val, priv->base + PCL_RCV_INT);
 	writel(PCL_RCV_INTX_ALL_ENABLE, priv->base + PCL_RCV_INTX);
 }
 
@@ -228,28 +241,51 @@ static const struct irq_domain_ops uniphier_intx_domain_ops = {
 	.map = uniphier_pcie_intx_map,
 };
 
-static void uniphier_pcie_irq_handler(struct irq_desc *desc)
+static void uniphier_pcie_misc_isr(struct pcie_port *pp, bool is_msi)
 {
-	struct pcie_port *pp = irq_desc_get_handler_data(desc);
 	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
 	struct uniphier_pcie_priv *priv = to_uniphier_pcie(pci);
-	struct irq_chip *chip = irq_desc_get_chip(desc);
-	unsigned long reg;
-	u32 val, bit, virq;
+	u32 val;
 
-	/* INT for debug */
 	val = readl(priv->base + PCL_RCV_INT);
 
 	if (val & PCL_CFG_BW_MGT_STATUS)
 		dev_dbg(pci->dev, "Link Bandwidth Management Event\n");
 	if (val & PCL_CFG_LINK_AUTO_BW_STATUS)
 		dev_dbg(pci->dev, "Link Autonomous Bandwidth Event\n");
-	if (val & PCL_CFG_AER_RC_ERR_MSI_STATUS)
-		dev_dbg(pci->dev, "Root Error\n");
-	if (val & PCL_CFG_PME_MSI_STATUS)
-		dev_dbg(pci->dev, "PME Interrupt\n");
+
+	if (is_msi) {
+		if (val & PCL_CFG_AER_RC_ERR_MSI_STATUS) {
+			dev_dbg(pci->dev, "Root Error Status\n");
+			if (priv->aer_irq)
+				generic_handle_irq(priv->aer_irq);
+		}
+
+		if (val & PCL_CFG_PME_MSI_STATUS) {
+			dev_dbg(pci->dev, "PME Interrupt\n");
+			if (priv->pme_irq)
+				generic_handle_irq(priv->pme_irq);
+		}
+	}
 
 	writel(val, priv->base + PCL_RCV_INT);
+}
+
+static void uniphier_pcie_msi_host_isr(struct pcie_port *pp)
+{
+	uniphier_pcie_misc_isr(pp, true);
+}
+
+static void uniphier_pcie_irq_handler(struct irq_desc *desc)
+{
+	struct pcie_port *pp = irq_desc_get_handler_data(desc);
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	struct uniphier_pcie_priv *priv = to_uniphier_pcie(pci);
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	unsigned long reg;
+	u32 val, bit, irq;
+
+	uniphier_pcie_misc_isr(pp, false);
 
 	/* INTx */
 	chained_irq_enter(chip, desc);
@@ -258,8 +294,8 @@ static void uniphier_pcie_irq_handler(struct irq_desc *desc)
 	reg = FIELD_GET(PCL_RCV_INTX_ALL_STATUS, val);
 
 	for_each_set_bit(bit, &reg, PCI_NUM_INTX) {
-		virq = irq_linear_revmap(priv->legacy_irq_domain, bit);
-		generic_handle_irq(virq);
+		irq = irq_linear_revmap(priv->legacy_irq_domain, bit);
+		generic_handle_irq(irq);
 	}
 
 	chained_irq_exit(chip, desc);
@@ -317,8 +353,45 @@ static int uniphier_pcie_host_init(struct pcie_port *pp)
 	return 0;
 }
 
+static int uniphier_pcie_port_get_irq(struct pcie_port *pp, u32 service)
+{
+	struct pci_dev *pcidev;
+	int irq = 0;
+
+	if (!IS_ENABLED(CONFIG_PCIEAER) && !IS_ENABLED(CONFIG_PCIE_PME))
+		return 0;
+
+	/*
+	 * Finds the device that matches 'service' from the devices
+	 * associated with Root Port, and returns its IRQ number.
+	 */
+	list_for_each_entry(pcidev, &pp->bridge->bus->devices, bus_list) {
+		irq = pcie_port_service_get_irq(pcidev, service);
+		if (irq)
+			break;
+	}
+
+	return irq;
+}
+
+static int uniphier_pcie_host_init_complete(struct pcie_port *pp)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	struct uniphier_pcie_priv *priv = to_uniphier_pcie(pci);
+
+	if (IS_ENABLED(CONFIG_PCIE_PME))
+		priv->pme_irq =
+			uniphier_pcie_port_get_irq(pp, PCIE_PORT_SERVICE_PME);
+	if (IS_ENABLED(CONFIG_PCIEAER))
+		priv->aer_irq =
+			uniphier_pcie_port_get_irq(pp, PCIE_PORT_SERVICE_AER);
+
+	return 0;
+}
+
 static const struct dw_pcie_host_ops uniphier_pcie_host_ops = {
 	.host_init = uniphier_pcie_host_init,
+	.msi_host_isr = uniphier_pcie_msi_host_isr,
 };
 
 static int uniphier_pcie_host_enable(struct uniphier_pcie_priv *priv)
@@ -398,7 +471,11 @@ static int uniphier_pcie_probe(struct platform_device *pdev)
 
 	priv->pci.pp.ops = &uniphier_pcie_host_ops;
 
-	return dw_pcie_host_init(&priv->pci.pp);
+	ret = dw_pcie_host_init(&priv->pci.pp);
+	if (ret)
+		return ret;
+
+	return uniphier_pcie_host_init_complete(&priv->pci.pp);
 }
 
 static const struct of_device_id uniphier_pcie_match[] = {
-- 
2.7.4