[PATCH next v2 1/2] PCI: keystone: add pci error irq handler

[PATCH next v2 1/2] PCI: keystone: add pci error irq handler

[Murali Karicheri]

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

Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Acked-by: Rob Herring <robh@kernel.org>
Cc: Rob Herring <robh+dt@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>
Cc: Bjorn Helgaas <bhelgaas@google.com>

---
 v2 - No change
 v1 - fixed a compilation issue reported by kbuild test robot
    - rebased to linux-next master branch
    - Added ack from Rob Herring

 .../devicetree/bindings/pci/pci-keystone.txt       |  1 +
 drivers/pci/host/pci-keystone-dw.c                 | 46 ++++++++++++++++++++++
 drivers/pci/host/pci-keystone.c                    | 32 +++++++++++++++
 drivers/pci/host/pci-keystone.h                    |  6 +++
 4 files changed, 85 insertions(+)

diff --git a/Documentation/devicetree/bindings/pci/pci-keystone.txt b/Documentation/devicetree/bindings/pci/pci-keystone.txt
index 54eae29..d08a4d5 100644
--- 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..2a45fe8 100644
--- a/drivers/pci/host/pci-keystone-dw.c
+++ b/drivers/pci/host/pci-keystone-dw.c
@@ -53,6 +53,29 @@
 #define IRQ_STATUS			0x184
 #define MSI_IRQ_OFFSET			4
 
+/*
+ * error IRQ bits. Enable following errors
+ *  - ERR_AER  - ECRC error - BIT(5)
+ *  - ERR_AXI  - AXI tag lookup fatal error BIT(4)
+ *  - ERR_CORR - Correctable error BIT(3)
+ *  - ERR_NONFATAL - Non fatal error BIT(2)
+ *  - ERR_FATAL - Fatal error BIT(1)
+ *  - ERR_SYS - System error (fatal, nonfatal or correctable error)
+ */
+#define ERR_AER				BIT(5)
+#define ERR_AXI				BIT(4)
+#define ERR_CORR			BIT(3)
+#define ERR_NONFATAL			BIT(2)
+#define ERR_FATAL			BIT(1)
+#define ERR_SYS				BIT(0)
+#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 +266,29 @@ 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);
+}
+
+bool ks_dw_pcie_handle_error_irq(struct device *dev, void __iomem *reg_base)
+{
+	u32 status;
+	bool ret = false;
+
+	status = readl(reg_base + ERR_IRQ_STATUS_RAW) & ERR_IRQ_ALL;
+	if (status) {
+		/* The PCIESS interrupt status buts are "write 1 to clear" */
+		if (status & ERR_FATAL_IRQ)
+			dev_err(dev, "PCIE fatal error detected\n");
+
+		/* ack the irq event. */
+		writel(status, reg_base + ERR_IRQ_STATUS);
+		ret = true;
+	}
+	return ret;
+}
+
 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..299f2f0 100644
--- 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 +227,10 @@ static void ks_pcie_setup_interrupts(struct keystone_pcie *ks_pcie)
 							 ks_pcie);
 		}
 	}
+
+	/* enable error interrupt */
+	if (ks_pcie->error_irq > 0)
+		ks_dw_pcie_enable_error_irq(ks_pcie->va_app_base);
 }
 
 /*
@@ -289,6 +294,16 @@ 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;
+
+	if (ks_dw_pcie_handle_error_irq(ks_pcie->pp.dev, ks_pcie->va_app_base))
+		return IRQ_HANDLED;
+
+	return IRQ_NONE;
+}
+
 static int __init ks_add_pcie_port(struct keystone_pcie *ks_pcie,
 			 struct platform_device *pdev)
 {
@@ -309,6 +324,22 @@ 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. As this is optional to define this, we will
+	 * just print a warning
+	 */
+	ks_pcie->error_irq = irq_of_parse_and_map(ks_pcie->np, 0);
+	if (ks_pcie->error_irq <= 0)
+		dev_warn(&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\n");
+			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 +407,7 @@ 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 = 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..2daa215 100644
--- a/drivers/pci/host/pci-keystone.h
+++ b/drivers/pci/host/pci-keystone.h
@@ -29,6 +29,10 @@ 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;
+
+	/* error interrupt */
+	int error_irq;
 
 	/* Application register space */
 	void __iomem		*va_app_base;
@@ -42,6 +46,8 @@ 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);
+bool 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,
-- 
1.9.1

[PATCH next v2 2/2] PCI: keystone: remove unnecessary goto statement

[Murali Karicheri]

Fix the misuse of goto statement in ks_pcie_get_irq_controller_info()
as simple return is more appropriate for this function. While at
it add an error log for absence of interrupt controller node.

Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Cc: Rob Herring <robh+dt@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>
Cc: Bjorn Helgaas <bhelgaas@google.com>

---
 v2 - removed an unnecessary extra line added in the previous version
 v1 - same as before initial version
 drivers/pci/host/pci-keystone.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/host/pci-keystone.c b/drivers/pci/host/pci-keystone.c
index 299f2f0..0234828 100644
--- a/drivers/pci/host/pci-keystone.c
+++ b/drivers/pci/host/pci-keystone.c
@@ -181,11 +181,13 @@ static int ks_pcie_get_irq_controller_info(struct keystone_pcie *ks_pcie,
 	*np_temp = of_find_node_by_name(np_pcie, controller);
 	if (!(*np_temp)) {
 		dev_err(dev, "Node for %s is absent\n", controller);
-		goto out;
+		return ret;
 	}
 	temp = of_irq_count(*np_temp);
-	if (!temp)
-		goto out;
+	if (!temp) {
+		dev_err(dev, "No entries in %s\n", controller);
+		return ret;
+	}
 	if (temp > max_host_irqs)
 		dev_warn(dev, "Too many %s interrupts defined %u\n",
 			(legacy ? "legacy" : "MSI"), temp);
@@ -203,7 +205,6 @@ static int ks_pcie_get_irq_controller_info(struct keystone_pcie *ks_pcie,
 		*num_irqs = temp;
 		ret = 0;
 	}
-out:
 	return ret;
 }
 
-- 
1.9.1

Re: [PATCH next v2 1/2] PCI: keystone: add pci error irq handler

[Bjorn Helgaas]

Hi Murali,

On Mon, Apr 11, 2016 at 10:50:30AM -0400, Murali Karicheri wrote:
> Keystone PCI hardware generates error interrupts at RC using platform
> irq instead of standard msi/legacy irq. Add a simple error handler that
> logs the fatal interrupt status to the console.
> 
> Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
> Acked-by: Rob Herring <robh@kernel.org>
> Cc: Rob Herring <robh+dt@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>
> Cc: Bjorn Helgaas <bhelgaas@google.com>

I applied this with minor changes to pci/host-keystone for v4.7.
See below:

> +bool ks_dw_pcie_handle_error_irq(struct device *dev, void __iomem *reg_base)
> +{
> +	u32 status;
> +	bool ret = false;
> +
> +	status = readl(reg_base + ERR_IRQ_STATUS_RAW) & ERR_IRQ_ALL;
> +	if (status) {
> +		/* The PCIESS interrupt status buts are "write 1 to clear" */
> +		if (status & ERR_FATAL_IRQ)
> +			dev_err(dev, "PCIE fatal error detected\n");
> +
> +		/* ack the irq event. */
> +		writel(status, reg_base + ERR_IRQ_STATUS);
> +		ret = true;
> +	}
> +	return ret;
> +}

It seems pointless to me to return true/false here and then:

> +static irqreturn_t pcie_err_irq_handler(int irq, void *priv)
> +{
> +	struct keystone_pcie *ks_pcie = priv;
> +
> +	if (ks_dw_pcie_handle_error_irq(ks_pcie->pp.dev, ks_pcie->va_app_base))
> +		return IRQ_HANDLED;
> +
> +	return IRQ_NONE;
> +}

convert the true/false to IRQ_HANDLED/IRQ_NONE here.  So I changed
ks_dw_pcie_handle_error_irq() to return IRQ_HANDLED/IRQ_NONE directly,
resulting in the patch below.

This is applied to pci/host-keystone for v4.7.


commit 7be92716c1aa40f5690e6a5f01fc0d385dd72303
Author: Murali Karicheri <m-karicheri2@ti.com>
Date:   Mon Apr 11 10:50:30 2016 -0400

    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: 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
--- 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
--- 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..6868918 100644
--- 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 = 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
--- 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,

Re: [PATCH next v2 2/2] PCI: keystone: remove unnecessary goto statement

[Bjorn Helgaas]

Hi Murali,

On Mon, Apr 11, 2016 at 10:50:31AM -0400, Murali Karicheri wrote:
> Fix the misuse of goto statement in ks_pcie_get_irq_controller_info()
> as simple return is more appropriate for this function. While at
> it add an error log for absence of interrupt controller node.
> 
> Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
> Cc: Rob Herring <robh+dt@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>
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> 
> ---
>  v2 - removed an unnecessary extra line added in the previous version
>  v1 - same as before initial version
>  drivers/pci/host/pci-keystone.c | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/pci/host/pci-keystone.c b/drivers/pci/host/pci-keystone.c
> index 299f2f0..0234828 100644
> --- a/drivers/pci/host/pci-keystone.c
> +++ b/drivers/pci/host/pci-keystone.c
> @@ -181,11 +181,13 @@ static int ks_pcie_get_irq_controller_info(struct keystone_pcie *ks_pcie,
>  	*np_temp = of_find_node_by_name(np_pcie, controller);
>  	if (!(*np_temp)) {
>  		dev_err(dev, "Node for %s is absent\n", controller);
> -		goto out;
> +		return ret;
>  	}
>  	temp = of_irq_count(*np_temp);
> -	if (!temp)
> -		goto out;
> +	if (!temp) {
> +		dev_err(dev, "No entries in %s\n", controller);
> +		return ret;
> +	}
>  	if (temp > max_host_irqs)
>  		dev_warn(dev, "Too many %s interrupts defined %u\n",
>  			(legacy ? "legacy" : "MSI"), temp);
> @@ -203,7 +205,6 @@ static int ks_pcie_get_irq_controller_info(struct keystone_pcie *ks_pcie,
>  		*num_irqs = temp;
>  		ret = 0;
>  	}
> -out:
>  	return ret;

I really like these cleanups; thanks for doing them.

I went a step further because I think we always know the value of
"ret" at each of these places, so I inserted those and dropped "ret"
altogether.

I applied the patch below to pci/host-keystone for v4.7.


commit a7ed67a22484f70b8d0c33c76ad7faeac97222a7
Author: Murali Karicheri <m-karicheri2@ti.com>
Date:   Mon Apr 11 10:50:31 2016 -0400

    PCI: keystone: Remove unnecessary goto statement
    
    Fix the misuse of goto statement in ks_pcie_get_irq_controller_info() as
    simple return is more appropriate for this function.  While at it add an
    error log for absence of interrupt controller node.
    
    [bhelgaas: drop "ret" altogether since we always know the return value]
    Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
    Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
    CC: Rob Herring <robh+dt@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/drivers/pci/host/pci-keystone.c b/drivers/pci/host/pci-keystone.c
index 6868918..95a66f77 100644
--- a/drivers/pci/host/pci-keystone.c
+++ b/drivers/pci/host/pci-keystone.c
@@ -160,7 +160,7 @@ static void ks_pcie_legacy_irq_handler(struct irq_desc *desc)
 static int ks_pcie_get_irq_controller_info(struct keystone_pcie *ks_pcie,
 					   char *controller, int *num_irqs)
 {
-	int temp, max_host_irqs, legacy = 1, *host_irqs, ret = -EINVAL;
+	int temp, max_host_irqs, legacy = 1, *host_irqs;
 	struct device *dev = ks_pcie->pp.dev;
 	struct device_node *np_pcie = dev->of_node, **np_temp;
 
@@ -181,11 +181,15 @@ static int ks_pcie_get_irq_controller_info(struct keystone_pcie *ks_pcie,
 	*np_temp = of_find_node_by_name(np_pcie, controller);
 	if (!(*np_temp)) {
 		dev_err(dev, "Node for %s is absent\n", controller);
-		goto out;
+		return -EINVAL;
 	}
+
 	temp = of_irq_count(*np_temp);
-	if (!temp)
-		goto out;
+	if (!temp) {
+		dev_err(dev, "No IRQ entries in %s\n", controller);
+		return -EINVAL;
+	}
+
 	if (temp > max_host_irqs)
 		dev_warn(dev, "Too many %s interrupts defined %u\n",
 			(legacy ? "legacy" : "MSI"), temp);
@@ -199,12 +203,13 @@ static int ks_pcie_get_irq_controller_info(struct keystone_pcie *ks_pcie,
 		if (!host_irqs[temp])
 			break;
 	}
+
 	if (temp) {
 		*num_irqs = temp;
-		ret = 0;
+		return 0;
 	}
-out:
-	return ret;
+
+	return -EINVAL;
 }
 
 static void ks_pcie_setup_interrupts(struct keystone_pcie *ks_pcie)
@@ -345,7 +350,7 @@ static int __init ks_add_pcie_port(struct keystone_pcie *ks_pcie,
 		return ret;
 	}
 
-	return ret;
+	return 0;
 }
 
 static const struct of_device_id ks_pcie_of_match[] = {
@@ -374,7 +379,7 @@ static int __init ks_pcie_probe(struct platform_device *pdev)
 	struct resource *res;
 	void __iomem *reg_p;
 	struct phy *phy;
-	int ret = 0;
+	int ret;
 
 	ks_pcie = devm_kzalloc(&pdev->dev, sizeof(*ks_pcie),
 				GFP_KERNEL);

Re: [PATCH next v2 1/2] PCI: keystone: add pci error irq handler

[Murali Karicheri]

On 04/19/2016 09:03 PM, Bjorn Helgaas wrote:
> Hi Murali,
> 
> On Mon, Apr 11, 2016 at 10:50:30AM -0400, Murali Karicheri wrote:
>> Keystone PCI hardware generates error interrupts at RC using platform
>> irq instead of standard msi/legacy irq. Add a simple error handler that
>> logs the fatal interrupt status to the console.
>>
>> Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
>> Acked-by: Rob Herring <robh@kernel.org>
>> Cc: Rob Herring <robh+dt@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>
>> Cc: Bjorn Helgaas <bhelgaas@google.com>
> 
> I applied this with minor changes to pci/host-keystone for v4.7.
> See below:
> 
>> +bool ks_dw_pcie_handle_error_irq(struct device *dev, void __iomem *reg_base)
>> +{
>> +	u32 status;
>> +	bool ret = false;
>> +
>> +	status = readl(reg_base + ERR_IRQ_STATUS_RAW) & ERR_IRQ_ALL;
>> +	if (status) {
>> +		/* The PCIESS interrupt status buts are "write 1 to clear" */
>> +		if (status & ERR_FATAL_IRQ)
>> +			dev_err(dev, "PCIE fatal error detected\n");
>> +
>> +		/* ack the irq event. */
>> +		writel(status, reg_base + ERR_IRQ_STATUS);
>> +		ret = true;
>> +	}
>> +	return ret;
>> +}
> 
> It seems pointless to me to return true/false here and then:
> 
>> +static irqreturn_t pcie_err_irq_handler(int irq, void *priv)
>> +{
>> +	struct keystone_pcie *ks_pcie = priv;
>> +
>> +	if (ks_dw_pcie_handle_error_irq(ks_pcie->pp.dev, ks_pcie->va_app_base))
>> +		return IRQ_HANDLED;
>> +
>> +	return IRQ_NONE;
>> +}
> 
> convert the true/false to IRQ_HANDLED/IRQ_NONE here.  So I changed
> ks_dw_pcie_handle_error_irq() to return IRQ_HANDLED/IRQ_NONE directly,
> resulting in the patch below.

I think that should be fine. Only reason, i did that way was that the pcie-designware
code is kept as a library of functions to configure the designware hardware common to
all platforms that has the designware core h/w and keep all of the platform specific info
such as IRQ handler to the platform glue driver such as pci-keystone.c. But that is not
true today as there is msi irq handler in this driver. So this is fine.

I will pull these from your designware pci/host-keystone and let you know if I see
any issues or send a diff patch to the list.

Once again, thanks for pulling this to v4.7.

Murali
> 
> This is applied to pci/host-keystone for v4.7.
> 
> 
> commit 7be92716c1aa40f5690e6a5f01fc0d385dd72303
> Author: Murali Karicheri <m-karicheri2@ti.com>
> Date:   Mon Apr 11 10:50:30 2016 -0400
> 
>     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: 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
> --- 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
> --- 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..6868918 100644
> --- 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 = 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
> --- 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,
> 


-- 
Murali Karicheri
Linux Kernel, Keystone

Re: [PATCH next v2 2/2] PCI: keystone: remove unnecessary goto statement

[Murali Karicheri]

On 04/19/2016 09:06 PM, Bjorn Helgaas wrote:
> Hi Murali,
> 
> On Mon, Apr 11, 2016 at 10:50:31AM -0400, Murali Karicheri wrote:
>> Fix the misuse of goto statement in ks_pcie_get_irq_controller_info()
>> as simple return is more appropriate for this function. While at
>> it add an error log for absence of interrupt controller node.
>>
>> Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
>> Cc: Rob Herring <robh+dt@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>
>> Cc: Bjorn Helgaas <bhelgaas@google.com>
>>
>> ---
>>  v2 - removed an unnecessary extra line added in the previous version
>>  v1 - same as before initial version
>>  drivers/pci/host/pci-keystone.c | 9 +++++----
>>  1 file changed, 5 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/pci/host/pci-keystone.c b/drivers/pci/host/pci-keystone.c
>> index 299f2f0..0234828 100644
>> --- a/drivers/pci/host/pci-keystone.c
>> +++ b/drivers/pci/host/pci-keystone.c
>> @@ -181,11 +181,13 @@ static int ks_pcie_get_irq_controller_info(struct keystone_pcie *ks_pcie,
>>  	*np_temp = of_find_node_by_name(np_pcie, controller);
>>  	if (!(*np_temp)) {
>>  		dev_err(dev, "Node for %s is absent\n", controller);
>> -		goto out;
>> +		return ret;
>>  	}
>>  	temp = of_irq_count(*np_temp);
>> -	if (!temp)
>> -		goto out;
>> +	if (!temp) {
>> +		dev_err(dev, "No entries in %s\n", controller);
>> +		return ret;
>> +	}
>>  	if (temp > max_host_irqs)
>>  		dev_warn(dev, "Too many %s interrupts defined %u\n",
>>  			(legacy ? "legacy" : "MSI"), temp);
>> @@ -203,7 +205,6 @@ static int ks_pcie_get_irq_controller_info(struct keystone_pcie *ks_pcie,
>>  		*num_irqs = temp;
>>  		ret = 0;
>>  	}
>> -out:
>>  	return ret;
> 
> I really like these cleanups; thanks for doing them.
> 
> I went a step further because I think we always know the value of
> "ret" at each of these places, so I inserted those and dropped "ret"
> altogether.
> 
> I applied the patch below to pci/host-keystone for v4.7.
Bjorn,

Which repo has your  pci/host-keystone branch?

I did a fetch of the remote pci at git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci.git
and could see only following host branches:-

git branch -r | grep "pci/pci/host-"

pci/pci/host-designware
pci/pci/host-generic
pci/pci/host-imx6
pci/pci/host-iproc
pci/pci/host-mvebu
pci/pci/host-rcar
pci/pci/host-tegra
pci/pci/host-vmd
pci/pci/host-xgene
pci/pci/host-xgene-dd2
pci/pci/host-xilinx-nwl

Thanks and Regards,

Murali

> 
> 
> commit a7ed67a22484f70b8d0c33c76ad7faeac97222a7
> Author: Murali Karicheri <m-karicheri2@ti.com>
> Date:   Mon Apr 11 10:50:31 2016 -0400
> 
>     PCI: keystone: Remove unnecessary goto statement
>     
>     Fix the misuse of goto statement in ks_pcie_get_irq_controller_info() as
>     simple return is more appropriate for this function.  While at it add an
>     error log for absence of interrupt controller node.
>     
>     [bhelgaas: drop "ret" altogether since we always know the return value]
>     Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
>     Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
>     CC: Rob Herring <robh+dt@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/drivers/pci/host/pci-keystone.c b/drivers/pci/host/pci-keystone.c
> index 6868918..95a66f77 100644
> --- a/drivers/pci/host/pci-keystone.c
> +++ b/drivers/pci/host/pci-keystone.c
> @@ -160,7 +160,7 @@ static void ks_pcie_legacy_irq_handler(struct irq_desc *desc)
>  static int ks_pcie_get_irq_controller_info(struct keystone_pcie *ks_pcie,
>  					   char *controller, int *num_irqs)
>  {
> -	int temp, max_host_irqs, legacy = 1, *host_irqs, ret = -EINVAL;
> +	int temp, max_host_irqs, legacy = 1, *host_irqs;
>  	struct device *dev = ks_pcie->pp.dev;
>  	struct device_node *np_pcie = dev->of_node, **np_temp;
>  
> @@ -181,11 +181,15 @@ static int ks_pcie_get_irq_controller_info(struct keystone_pcie *ks_pcie,
>  	*np_temp = of_find_node_by_name(np_pcie, controller);
>  	if (!(*np_temp)) {
>  		dev_err(dev, "Node for %s is absent\n", controller);
> -		goto out;
> +		return -EINVAL;
>  	}
> +
>  	temp = of_irq_count(*np_temp);
> -	if (!temp)
> -		goto out;
> +	if (!temp) {
> +		dev_err(dev, "No IRQ entries in %s\n", controller);
> +		return -EINVAL;
> +	}
> +
>  	if (temp > max_host_irqs)
>  		dev_warn(dev, "Too many %s interrupts defined %u\n",
>  			(legacy ? "legacy" : "MSI"), temp);
> @@ -199,12 +203,13 @@ static int ks_pcie_get_irq_controller_info(struct keystone_pcie *ks_pcie,
>  		if (!host_irqs[temp])
>  			break;
>  	}
> +
>  	if (temp) {
>  		*num_irqs = temp;
> -		ret = 0;
> +		return 0;
>  	}
> -out:
> -	return ret;
> +
> +	return -EINVAL;
>  }
>  
>  static void ks_pcie_setup_interrupts(struct keystone_pcie *ks_pcie)
> @@ -345,7 +350,7 @@ static int __init ks_add_pcie_port(struct keystone_pcie *ks_pcie,
>  		return ret;
>  	}
>  
> -	return ret;
> +	return 0;
>  }
>  
>  static const struct of_device_id ks_pcie_of_match[] = {
> @@ -374,7 +379,7 @@ static int __init ks_pcie_probe(struct platform_device *pdev)
>  	struct resource *res;
>  	void __iomem *reg_p;
>  	struct phy *phy;
> -	int ret = 0;
> +	int ret;
>  
>  	ks_pcie = devm_kzalloc(&pdev->dev, sizeof(*ks_pcie),
>  				GFP_KERNEL);
> 


-- 
Murali Karicheri
Linux Kernel, Keystone