On Thu, May 12, 2022 at 01:45:41PM +0300, Dmitry Baryshkov wrote:
> On some of Qualcomm platforms each group of 32 MSI vectors is routed to the
> separate GIC interrupt. Implement support for such configuraions by
> parsing "msi0" ... "msi7" interrupts and attaching them to the chained
> handler.
>
> Note, that if DT doesn't list an array of MSI interrupts and uses single
> "msi" IRQ, the driver will limit the amount of supported MSI vectors
> accordingly (to 32).
>
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
> ---
> .../pci/controller/dwc/pcie-designware-host.c | 33 ++++++++++++++++++-
> drivers/pci/controller/dwc/pcie-designware.h | 1 +
> 2 files changed, 33 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
> index 6b0c7b75391f..258bafa306dc 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-host.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-host.c
> @@ -291,7 +291,8 @@ static void dw_pcie_msi_init(struct pcie_port *pp)
> static int dw_pcie_msi_host_init(struct pcie_port *pp)
> {
> struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> - struct platform_device *pdev = to_platform_device(pci->dev);
> + struct device *dev = pci->dev;
> + struct platform_device *pdev = to_platform_device(dev);
> int ret;
> u32 ctrl, num_ctrls;
>
> @@ -299,6 +300,36 @@ static int dw_pcie_msi_host_init(struct pcie_port *pp)
> for (ctrl = 0; ctrl < num_ctrls; ctrl++)
> pp->irq_mask[ctrl] = ~0;
>
> + if (pp->has_split_msi_irq) {
> + char irq_name[] = "msiXX";
> + int irq;
> +
> + if (!pp->msi_irq[0]) {
> + irq = platform_get_irq_byname_optional(pdev, irq_name);
> + if (irq == -ENXIO) {
> + num_ctrls = 1;
> + pp->num_vectors = min((u32)MAX_MSI_IRQS_PER_CTRL, pp->num_vectors);
min_t()?
> + dev_warn(dev, "No additional MSI IRQs, limiting amount of MSI vectors to %d\n",
> + pp->num_vectors);
We already print the number of vectors used a bit further down in this
function, no need to repeat it here.
This will also be printed when booting with devicetrees which only have
a single "msi" interrupt (which isn't deprecated).
Perhaps a debug printk is sufficient, or at least something less verbose.
> + } else {
> + pp->msi_irq[0] = irq;
> + }
> + }
> +
> + /* If we fallback to the single MSI ctrl IRQ, this loop will be skipped as num_ctrls is 1 */
Please break lines at 80 columns unless not doing so improves
readability.
> + for (ctrl = 1; ctrl < num_ctrls; ctrl++) {
> + if (pp->msi_irq[ctrl])
> + continue;
> +
> + snprintf(irq_name, sizeof(irq_name), "msi%d", ctrl);
> + irq = platform_get_irq_byname(pdev, irq_name);
> + if (irq < 0)
> + return irq;
> +
> + pp->msi_irq[ctrl] = irq;
> + }
> + }
> +
> if (!pp->msi_irq[0]) {
> int irq = platform_get_irq_byname_optional(pdev, "msi");
Johan
