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>

diff --git a/Documentation/devicetree/bindings/pci/pci-keystone.txt b/Documentation/devicetree/bindings/pci/pci-keystone.txt
index 54eae29..d08a4d5 100644 (file)
--- a/Documentation/devicetree/bindings/pci/pci-keystone.txt
+++ b/Documentation/devicetree/bindings/pci/pci-keystone.txt
@@ -56,6 +56,7 @@ Optional properties:-
        phy-names: name of the Generic Keystine SerDes phy for PCI
          - If boot loader already does PCI link establishment, then phys and
            phy-names shouldn't be present.
+       interrupts: platform interrupt for error interrupts.
 
 Designware DT Properties not applicable for Keystone PCI
 

diff --git a/drivers/pci/host/pci-keystone-dw.c b/drivers/pci/host/pci-keystone-dw.c
index 6153853..4151509 100644 (file)
--- 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)
 {
 }

diff --git a/drivers/pci/host/pci-keystone.c b/drivers/pci/host/pci-keystone.c
index b71f55b..5812000 100644 (file)
--- a/drivers/pci/host/pci-keystone.c
+++ b/drivers/pci/host/pci-keystone.c
@@ -15,6 +15,7 @@
 #include <linux/irqchip/chained_irq.h>
 #include <linux/clk.h>
 #include <linux/delay.h>
+#include <linux/interrupt.h>
 #include <linux/irqdomain.h>
 #include <linux/module.h>
 #include <linux/msi.h>
@@ -226,6 +227,9 @@ static void ks_pcie_setup_interrupts(struct keystone_pcie *ks_pcie)
                                                         ks_pcie);
                }
        }
+
+       if (ks_pcie->error_irq > 0)
+               ks_dw_pcie_enable_error_irq(ks_pcie->va_app_base);
 }
 
 /*
@@ -289,6 +293,14 @@ static struct pcie_host_ops keystone_pcie_host_ops = {
        .scan_bus = ks_dw_pcie_v3_65_scan_bus,
 };
 
+static irqreturn_t pcie_err_irq_handler(int irq, void *priv)
+{
+       struct keystone_pcie *ks_pcie = priv;
+
+       return ks_dw_pcie_handle_error_irq(ks_pcie->pp.dev,
+                                          ks_pcie->va_app_base);
+}
+
 static int __init ks_add_pcie_port(struct keystone_pcie *ks_pcie,
                         struct platform_device *pdev)
 {
@@ -309,6 +321,22 @@ static int __init ks_add_pcie_port(struct keystone_pcie *ks_pcie,
                        return ret;
        }
 
+       /*
+        * Index 0 is the platform interrupt for error interrupt
+        * from RC.  This is optional.
+        */
+       ks_pcie->error_irq = irq_of_parse_and_map(ks_pcie->np, 0);
+       if (ks_pcie->error_irq <= 0)
+               dev_info(&pdev->dev, "no error IRQ defined\n");
+       else {
+               if (request_irq(ks_pcie->error_irq, pcie_err_irq_handler,
+                               IRQF_SHARED, "pcie-error-irq", ks_pcie) < 0) {
+                       dev_err(&pdev->dev, "failed to request error IRQ %d\n",
+                               ks_pcie->error_irq);
+                       return ret;
+               }
+       }
+
        pp->root_bus_nr = -1;
        pp->ops = &keystone_pcie_host_ops;
        ret = ks_dw_pcie_host_init(ks_pcie, ks_pcie->msi_intc_np);
@@ -376,6 +404,7 @@ static int __init ks_pcie_probe(struct platform_device *pdev)
        devm_release_mem_region(dev, res->start, resource_size(res));
 
        pp->dev = dev;
+       ks_pcie->np = dev->of_node;
        platform_set_drvdata(pdev, ks_pcie);
        ks_pcie->clk = devm_clk_get(dev, "pcie");
        if (IS_ERR(ks_pcie->clk)) {

diff --git a/drivers/pci/host/pci-keystone.h b/drivers/pci/host/pci-keystone.h
index f0944e8..a5b0cb2 100644 (file)
--- a/drivers/pci/host/pci-keystone.h
+++ b/drivers/pci/host/pci-keystone.h
@@ -29,6 +29,9 @@ struct keystone_pcie {
        int                     msi_host_irqs[MAX_MSI_HOST_IRQS];
        struct                  device_node *msi_intc_np;
        struct irq_domain       *legacy_irq_domain;
+       struct device_node      *np;
+
+       int error_irq;
 
        /* Application register space */
        void __iomem            *va_app_base;
@@ -42,6 +45,9 @@ phys_addr_t ks_dw_pcie_get_msi_addr(struct pcie_port *pp);
 /* Keystone specific PCI controller APIs */
 void ks_dw_pcie_enable_legacy_irqs(struct keystone_pcie *ks_pcie);
 void ks_dw_pcie_handle_legacy_irq(struct keystone_pcie *ks_pcie, int offset);
+void ks_dw_pcie_enable_error_irq(void __iomem *reg_base);
+irqreturn_t ks_dw_pcie_handle_error_irq(struct device *dev,
+                                       void __iomem *reg_base);
 int  ks_dw_pcie_host_init(struct keystone_pcie *ks_pcie,
                        struct device_node *msi_intc_np);
 int ks_dw_pcie_wr_other_conf(struct pcie_port *pp, struct pci_bus *bus,