From d05f9a087bf0603e50e218cab7b2fed7c8da6fa6 Mon Sep 17 00:00:00 2001 From: Dmitry Baryshkov Date: Thu, 7 Jul 2022 16:47:31 +0300 Subject: [PATCH] PCI: dwc: Handle MSIs routed to multiple GIC interrupts On some Qualcomm platforms each group of 32 MSI vectors is routed to a separate GIC interrupt. Implement support for such configurations by parsing "msi0" ... "msiX" interrupts and attaching them to the chained handler. Note that if DT doesn't list an array of MSI interrupts and uses a single "msi" IRQ, the driver will limit the number of supported MSI vectors to 32. Link: https://lore.kernel.org/r/20220707134733.2436629-5-dmitry.baryshkov@linaro.org Signed-off-by: Dmitry Baryshkov Signed-off-by: Bjorn Helgaas Reviewed-by: Rob Herring Reviewed-by: Johan Hovold Reviewed-by: Manivannan Sadhasivam --- .../pci/controller/dwc/pcie-designware-host.c | 61 ++++++++++++++++++- 1 file changed, 58 insertions(+), 3 deletions(-) diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c index 89316967c0703..7746f94a715f5 100644 --- a/drivers/pci/controller/dwc/pcie-designware-host.c +++ b/drivers/pci/controller/dwc/pcie-designware-host.c @@ -291,6 +291,46 @@ static void dw_pcie_msi_init(struct dw_pcie_rp *pp) dw_pcie_writel_dbi(pci, PCIE_MSI_ADDR_HI, upper_32_bits(msi_target)); } +static int dw_pcie_parse_split_msi_irq(struct dw_pcie_rp *pp) +{ + struct dw_pcie *pci = to_dw_pcie_from_pp(pp); + struct device *dev = pci->dev; + struct platform_device *pdev = to_platform_device(dev); + u32 ctrl, max_vectors; + int irq; + + /* Parse any "msiX" IRQs described in the devicetree */ + for (ctrl = 0; ctrl < MAX_MSI_CTRLS; ctrl++) { + char msi_name[] = "msiX"; + + msi_name[3] = '0' + ctrl; + 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; + } + + /* If no "msiX" IRQs, caller should fallback to "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 %u\n", + max_vectors); + pp->num_vectors = max_vectors; + } + if (!pp->num_vectors) + pp->num_vectors = max_vectors; + + return 0; +} + static int dw_pcie_msi_host_init(struct dw_pcie_rp *pp) { struct dw_pcie *pci = to_dw_pcie_from_pp(pp); @@ -299,10 +339,19 @@ static int dw_pcie_msi_host_init(struct dw_pcie_rp *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]) { pp->msi_irq[0] = platform_get_irq_byname_optional(pdev, "msi"); if (pp->msi_irq[0] < 0) { @@ -312,6 +361,8 @@ static int dw_pcie_msi_host_init(struct dw_pcie_rp *pp) } } + 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); @@ -410,7 +461,11 @@ int dw_pcie_host_init(struct dw_pcie_rp *pp) of_property_read_bool(np, "msi-parent") || of_property_read_bool(np, "msi-map")); - if (!pp->num_vectors) { + /* + * For the has_msi_ctrl case the default assignment is handled + * in the dw_pcie_msi_host_init(). + */ + 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"); -- 2.39.5