PCI: designware: Implement multivector MSI IRQ setup

Implement multivector MSI IRQ setup.  This allows to set up and use multiple
MSI IRQs per device.

[bhelgaas: changelog, use -EINVAL instead of -ENOSYS]
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Pratyush Anand <pratyush.anand@gmail.com>

1 files changed, 31 insertions, 0 deletions

diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c
index ea5b285baea6..66d789aefa0d 100644
--- a/drivers/pci/host/pcie-designware.c
+++ b/drivers/pci/host/pcie-designware.c
@@ -286,6 +286,9 @@ static int assign_irq(int no_irqs, struct msi_desc *desc, int *pos)
         }
 
         *pos = pos0;
+        desc->nvec_used = no_irqs;
+        desc->msi_attrib.multiple = order_base_2(no_irqs);
+
         return irq;
 
 no_valid_irq:
@@ -329,6 +332,33 @@ static int dw_msi_setup_irq(struct msi_controller *chip, struct pci_dev *pdev,
         return 0;
 }
 
+static int dw_msi_setup_irqs(struct msi_controller *chip, struct pci_dev *pdev,
+                             int nvec, int type)
+{
+#ifdef CONFIG_PCI_MSI
+        int irq, pos;
+        struct msi_desc *desc;
+        struct pcie_port *pp = sys_to_pcie(pdev->bus->sysdata);
+
+        /* MSI-X interrupts are not supported */
+        if (type == PCI_CAP_ID_MSIX)
+                return -EINVAL;
+
+        WARN_ON(!list_is_singular(&pdev->dev.msi_list));
+        desc = list_entry(pdev->dev.msi_list.next, struct msi_desc, list);
+
+        irq = assign_irq(nvec, desc, &pos);
+        if (irq < 0)
+                return irq;
+
+        dw_msi_setup_msg(pp, irq, pos);
+
+        return 0;
+#else
+        return -EINVAL;
+#endif
+}
+
 static void dw_msi_teardown_irq(struct msi_controller *chip, unsigned int irq)
 {
         struct irq_data *data = irq_get_irq_data(irq);
@@ -340,6 +370,7 @@ static void dw_msi_teardown_irq(struct msi_controller *chip, unsigned int irq)
 
 static struct msi_controller dw_pcie_msi_chip = {
         .setup_irq = dw_msi_setup_irq,
+        .setup_irqs = dw_msi_setup_irqs,
         .teardown_irq = dw_msi_teardown_irq,
 };