PCI: keystone: Add error IRQ handler

Keystone PCI hardware generates error interrupts at RC using a platform IRQ
instead of a standard MSI or legacy IRQ.  Add a simple error handler that
logs the fatal interrupt status to the console.

[bhelgaas: s/node/dev->of_node/, tidy comments, return irqreturn_t directly]
Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rob Herring <robh@kernel.org>
CC: Pawel Moll <pawel.moll@arm.com>
CC: Mark Rutland <mark.rutland@arm.com>
CC: Ian Campbell <ijc+devicetree@hellion.org.uk>
CC: Kumar Gala <galak@codeaurora.org>

1 files changed, 38 insertions, 0 deletions

diff --git a/drivers/pci/host/pci-keystone-dw.c b/drivers/pci/host/pci-keystone-dw.c
index 6153853ca9c3..41515092eb0d 100644
--- a/drivers/pci/host/pci-keystone-dw.c
+++ b/drivers/pci/host/pci-keystone-dw.c
@@ -14,6 +14,7 @@
 
 #include <linux/irq.h>
 #include <linux/irqdomain.h>
+#include <linux/irqreturn.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_pci.h>
@@ -53,6 +54,21 @@
 #define IRQ_STATUS			0x184
 #define MSI_IRQ_OFFSET			4
 
+/* Error IRQ bits */
+#define ERR_AER		BIT(5)	/* ECRC error */
+#define ERR_AXI		BIT(4)	/* AXI tag lookup fatal error */
+#define ERR_CORR	BIT(3)	/* Correctable error */
+#define ERR_NONFATAL	BIT(2)	/* Non-fatal error */
+#define ERR_FATAL	BIT(1)	/* Fatal error */
+#define ERR_SYS		BIT(0)	/* System (fatal, non-fatal, or correctable) */
+#define ERR_IRQ_ALL	(ERR_AER | ERR_AXI | ERR_CORR | \
+			 ERR_NONFATAL | ERR_FATAL | ERR_SYS)
+#define ERR_FATAL_IRQ	(ERR_FATAL | ERR_AXI)
+#define ERR_IRQ_STATUS_RAW		0x1c0
+#define ERR_IRQ_STATUS			0x1c4
+#define ERR_IRQ_ENABLE_SET		0x1c8
+#define ERR_IRQ_ENABLE_CLR		0x1cc
+
 /* Config space registers */
 #define DEBUG0				0x728
 
@@ -243,6 +259,28 @@ void ks_dw_pcie_handle_legacy_irq(struct keystone_pcie *ks_pcie, int offset)
 	writel(offset, ks_pcie->va_app_base + IRQ_EOI);
 }
 
+void ks_dw_pcie_enable_error_irq(void __iomem *reg_base)
+{
+	writel(ERR_IRQ_ALL, reg_base + ERR_IRQ_ENABLE_SET);
+}
+
+irqreturn_t ks_dw_pcie_handle_error_irq(struct device *dev,
+					void __iomem *reg_base)
+{
+	u32 status;
+
+	status = readl(reg_base + ERR_IRQ_STATUS_RAW) & ERR_IRQ_ALL;
+	if (!status)
+		return IRQ_NONE;
+
+	if (status & ERR_FATAL_IRQ)
+		dev_err(dev, "fatal error (status %#010x)\n", status);
+
+	/* Ack the IRQ; status bits are RW1C */
+	writel(status, reg_base + ERR_IRQ_STATUS);
+	return IRQ_HANDLED;
+}
+
 static void ks_dw_pcie_ack_legacy_irq(struct irq_data *d)
 {
 }