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

From: [email-masked] (Murali Karicheri)
Date: Thu, 31 Mar 2016 18:11:48 -0400

On 03/22/2016 03:52 PM, 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 <[email-masked]>
> Cc: Rob Herring <[email-masked]>
> Cc: Pawel Moll <[email-masked]>
> Cc: Mark Rutland <[email-masked]>
> Cc: Ian Campbell <[email-masked]>
> Cc: Kumar Gala <[email-masked]>
> Cc: Bjorn Helgaas <[email-masked]>
> ---
>  .../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 ed34c95..524901d 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
>  
> @@ -248,6 +271,29 @@ 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,
> 
Bjorn,

Will you be applying this to your PCI next branch?
-- 
Murali Karicheri
Linux Kernel, Keystone