On Mon, May 23, 2022 at 09:18:33PM +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 configurations by
> parsing "msi0" ... "msiN" 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 | 61 +++++++++++++++++--
> 1 file changed, 57 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
> index a076abe6611c..98a57249ecaf 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-host.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-host.c
> @@ -288,6 +288,47 @@ static void dw_pcie_msi_init(struct pcie_port *pp)
> dw_pcie_writel_dbi(pci, PCIE_MSI_ADDR_HI, upper_32_bits(msi_target));
> }
>
> +static const char * const split_msi_names[] = {
> + "msi0", "msi1", "msi2", "msi3",
> + "msi4", "msi5", "msi6", "msi7",
> +};
> +
> +static int dw_pcie_parse_split_msi_irq(struct pcie_port *pp)
> +{
> + struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> + struct device *dev = pci->dev;
> + struct platform_device *pdev = to_platform_device(dev);
> + int irq;
> + u32 ctrl, max_vectors;
> +
> + /* Parse as many IRQs as described in the devicetree. */
> + for (ctrl = 0; ctrl < MAX_MSI_CTRLS; ctrl++) {
> + irq = platform_get_irq_byname_optional(pdev, split_msi_names[ctrl]);
> + if (irq == -ENXIO)
> + break;
> + if (irq < 0)
> + return dev_err_probe(dev, irq,
> + "Failed to parse MSI IRQ '%s'\n",
> + split_msi_names[ctrl]);
> +
> + pp->msi_irq[ctrl] = irq;
> + }
> +
> + /* If there were no "msiN" IRQs at all, fallback to the standard "msi" IRQ. */
> + if (ctrl == 0)
> + return -ENXIO;
> +
> + max_vectors = ctrl * MAX_MSI_IRQS_PER_CTRL;
> + if (pp->num_vectors > max_vectors) {
> + dev_warn(dev, "Exceeding number of MSI vectors, limiting to %d\n", max_vectors);
%u
break line after last comma?
> + pp->num_vectors = max_vectors;
> + }
> + if (!pp->num_vectors)
> + pp->num_vectors = max_vectors;
> +
> + return 0;
> +}
> +
> static int dw_pcie_msi_host_init(struct pcie_port *pp)
> {
> struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> @@ -296,21 +337,32 @@ static int dw_pcie_msi_host_init(struct pcie_port *pp)
> int ret;
> u32 ctrl, num_ctrls;
>
> - num_ctrls = pp->num_vectors / MAX_MSI_IRQS_PER_CTRL;
> - for (ctrl = 0; ctrl < num_ctrls; ctrl++)
> + for (ctrl = 0; ctrl < MAX_MSI_CTRLS; ctrl++)
> pp->irq_mask[ctrl] = ~0;
>
> + if (!pp->msi_irq[0]) {
> + ret = dw_pcie_parse_split_msi_irq(pp);
> + if (ret < 0 && ret != -ENXIO)
> + return ret;
> + }
> +
> + if (!pp->num_vectors)
> + pp->num_vectors = MSI_DEF_NUM_VECTORS;
> + num_ctrls = pp->num_vectors / MAX_MSI_IRQS_PER_CTRL;
> +
> if (!pp->msi_irq[0]) {
> int irq = platform_get_irq_byname_optional(pdev, "msi");
>
> if (irq < 0) {
> irq = platform_get_irq(pdev, 0);
> if (irq < 0)
> - return irq;
> + return dev_err_probe(dev, irq, "Failed to parse MSI irq\n");
> }
> pp->msi_irq[0] = irq;
> }
>
> + dev_dbg(dev, "Using %d MSI vectors\n", pp->num_vectors);
> +
> pp->msi_irq_chip = &dw_pci_msi_bottom_irq_chip;
>
> ret = dw_pcie_allocate_domains(pp);
> @@ -407,7 +459,8 @@ int dw_pcie_host_init(struct pcie_port *pp)
> of_property_read_bool(np, "msi-parent") ||
> of_property_read_bool(np, "msi-map"));
>
> - if (!pp->num_vectors) {
> + /* for the has_msi_ctrl the default assignment is handled inside dw_pcie_msi_host_init() */
Add the missing "case" after "has_msi_ctrl".
s/inside/in/
Please make this a multiline comment split at < 80 chars.
And follow the comment style of the driver and start with a capital
letter.
> + if (!pp->has_msi_ctrl && !pp->num_vectors) {
> pp->num_vectors = MSI_DEF_NUM_VECTORS;
> } else if (pp->num_vectors > MAX_MSI_IRQS) {
> dev_err(dev, "Invalid number of vectors\n");
Looks good now otherwise.
But please consider Rob's suggestion for generating the interrupt names.
Reviewed-by: Johan Hovold <johan+linaro@xxxxxxxxxx>
