Re: [PATCH 2/3] PCI: Use dedicated Xilinx controller irq number for AER

From: Bjorn Helgaas
Date: Mon Aug 06 2018 - 17:04:03 EST


On Wed, Aug 01, 2018 at 10:14:48PM +0530, Bharat Kumar Gogada wrote:
> Xilinx ZynqMP PS PCIe does not report AER interrupts using Advanced
> Error Interrupt Message Number. The controller has dedicated interrupt line
> for reporting PCIe errors along with AER.
>
> Using pci_dev->sysdata of root port to save controller irq number, which
> will be used for registering AER irq handler.
>
> Signed-off-by: Bharat Kumar Gogada <bharat.kumar.gogada@xxxxxxxxxx>
> ---
> drivers/pci/quirks.c | 29 +++++++++++++++++++++++++++++
> 1 files changed, 29 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index f439de8..e666373 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -4753,3 +4753,32 @@ static void quirk_gpu_hda(struct pci_dev *hda)
> PCI_CLASS_MULTIMEDIA_HD_AUDIO, 8, quirk_gpu_hda);
> DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_NVIDIA, PCI_ANY_ID,
> PCI_CLASS_MULTIMEDIA_HD_AUDIO, 8, quirk_gpu_hda);
> +
> +#if defined(CONFIG_ARCH_ZYNQMP) && defined(CONFIG_PCIE_XILINX_NWL) && \
> + defined(CONFIG_PCIEAER)
> +/*
> + * Xilinx ZynqMP PS PCIe does not report AER interrupts using Advanced
> + * Error Interrupt Message Number. The controller has dedicated interrupt line
> + * for reporting PCIe errors along with AER.

Your comment says "PCIe errors along with AER", but your ifdef tests
CONFIG_PCIEAER. Per PCIe r4.0, sec 6.2.6, interrupts can be generated
even if AER isn't supported. Don't we want to allow that?

> + */
> +#include <linux/of.h>
> +#include <linux/of_irq.h>
> +
> +static void quirk_xilinx_aer_irq(struct pci_dev *dev)
> +{
> + struct device_node *dev_node;
> +
> + if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT &&
> + pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR)) {
> + dev_node = of_find_compatible_node(NULL, NULL,
> + "xlnx,nwl-pcie-2.11");
> + if (!dev_node) {
> + dev_err(&dev->dev, "Error could not find ZynqMP PS PCIe node\n");

Use pci_err().

Doesn't arm64 support generic kernels that may contain support for
several platforms? We don't want a warning if a generic kernel
happens to be running on a non-ZynqMP system.

> + return;
> + }
> +
> + dev->sysdata = dev_node->data;
> + }
> +}
> +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_XILINX, PCI_ANY_ID, quirk_xilinx_aer_irq);
> +#endif
> --
> 1.7.1
>