On Fri, Jun 03, 2022 at 10:41:34AM +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).
>
> Reviewed-by: Rob Herring <robh@xxxxxxxxxx>
> Reviewed-by: Johan Hovold <johan+linaro@xxxxxxxxxx>
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
> ---
> .../pci/controller/dwc/pcie-designware-host.c | 63 +++++++++++++++++--
> 1 file changed, 59 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
> index 85c1160792e1..d1f9e20df903 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-host.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-host.c
> @@ -289,6 +289,46 @@ 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 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++) {
> + char *msi_name = "msiX";
> +
> + msi_name[3] = '0' + ctrl;
This oopses here as the string constant is read only:
[ 19.787973] Unable to handle kernel write to read-only memory at virtual address ffffaa14f831afd3
Did you not test the series before posting?
You need to define msi_name as:
char msi_name[] = "msiX";
> + irq = platform_get_irq_byname_optional(pdev, msi_name);
> + if (irq == -ENXIO)
> + break;
> + if (irq < 0)
> + return dev_err_probe(dev, irq,
> + "Failed to parse MSI IRQ '%s'\n",
> + msi_name);
> +
> + pp->msi_irq[ctrl] = irq;
> + }
Johan
