Re: [PATCH V2 3/5] PCI: xilinx: Modifying AXI PCIe Host Bridge driver to work on both Zynq and Microblaze

Arnd Bergmann
2016-01-12T22:28:23Z

On Tuesday 12 January 2016 23:06:11 Bharat Kumar Gogada wrote:
> Modifying Xilinx AXI PCIe Host Bridge Soft IP driver to work on both
> Zynq and Microblaze Architectures.
> With these modifications drivers/pci/host/pcie-xilinx.c, will
> work on both Zynq and Microblaze Architectures.
>
> Signed-off-by: Bharat Kumar Gogada <bharatku@xilinx.com>
> Signed-off-by: Ravi Kiran Gummaluri <rgummal@xilinx.com>

I think this patch should be split into three, as you are doing three
unrelated things here.

> ---
> Changes:
> Changed Total number of MSI IRQ count logic according to both architectures.
> Updated MSI assigning functions accordingly to new count.
> Modified irq_domain_add_linear with new MSI IRQ count.
> Added #ifdef to pci_fixup_irqs which is ARM specific API.
> ---
> drivers/pci/host/pcie-xilinx.c | 22 +++++++++++++++++-----
> 1 file changed, 17 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/pci/host/pcie-xilinx.c b/drivers/pci/host/pcie-xilinx.c
> index 3e3757f..1981948 100644
> --- a/drivers/pci/host/pcie-xilinx.c
> +++ b/drivers/pci/host/pcie-xilinx.c
> @@ -92,7 +92,12 @@
> #define ECAM_DEV_NUM_SHIFT 12
>
> /* Number of MSI IRQs */
> -#define XILINX_NUM_MSI_IRQS 128
> +#define XILINX_NUM_MSI_IRQS 128
> +#ifdef CONFIG_ARM
> +#define TOT_NR_IRQS XILINX_NUM_MSI_IRQS
> +#else
> +#define TOT_NR_IRQS (NR_IRQS + XILINX_NUM_MSI_IRQS)
> +#endif

Something looks wrong here in the microblaze variant. What does NR_IRQS
have to do with it?

> @@ -238,15 +243,20 @@ static void xilinx_pcie_destroy_msi(unsigned int irq)
> */
> static int xilinx_pcie_assign_msi(struct xilinx_pcie_port *port)
> {
> + int irq;
> int pos;
>
> pos = find_first_zero_bit(msi_irq_in_use, XILINX_NUM_MSI_IRQS);
> - if (pos < XILINX_NUM_MSI_IRQS)
> + irq = pos;
> +#ifdef CONFIG_MICROBLAZE
> + irq = XILINX_NUM_MSI_IRQS + pos;
> +#endif

if (IS_ENABLED(CONFIG_MICROBLAZE))
irq = XILINX_NUM_MSI_IRQS + pos;

> @@ -705,7 +715,9 @@ static int xilinx_pcie_probe(struct platform_device *pdev)
> #endif
> pci_scan_child_bus(bus);
> pci_assign_unassigned_bus_resources(bus);
> +#ifdef CONFIG_ARM
> pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci);
> +#endif
> pci_bus_add_devices(bus);
> platform_set_drvdata(pdev, port);

Here it looks like microblaze gets it right. I'm not sure why we still
need the pci_fixup_irqs() on ARM, but my feeling is that this should be
fixed in common code.

Arnd