ks_pcie_legacy_irq_handler() uses 'virq' to get the IRQ number offset.
This offset is used to get the correct IRQ_STATUS register
corresponding to the IRQ line that raised the interrupt.
There is no guarantee that 'virq' assigned for consecutive hardware
IRQ will be contiguous. And this might get us an incorrect IRQ number
offset.

Fix it here by using 'hwirq' to get the IRQ number offset.

Link: https://lkml.kernel.org/r/bb081d21-7c03-0357-4294-7e92d95d838c@arm.com
Signed-off-by: Kishon Vijay Abraham I <redacted>
---
 drivers/pci/controller/dwc/pci-keystone.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/controller/dwc/pci-keystone.c b/drivers/pci/controller/dwc/pci-keystone.c
index e8b1d8eca78e..d35ac712a9f8 100644
--- a/drivers/pci/controller/dwc/pci-keystone.c
+++ b/drivers/pci/controller/dwc/pci-keystone.c

@@ -87,7 +87,7 @@ struct keystone_pcie {
 	struct dw_pcie		*pci;
 	/* PCI Device ID */
 	u32			device_id;
-	int			legacy_host_irqs[PCI_NUM_INTX];
+	int			legacy_host_irq;
 	struct			device_node *legacy_intc_np;
 
 	int			msi_host_irqs[MAX_MSI_HOST_IRQS];

@@ -582,11 +582,11 @@ static void ks_pcie_msi_irq_handler(struct irq_desc *desc)
  */
 static void ks_pcie_legacy_irq_handler(struct irq_desc *desc)
 {
-	unsigned int irq = irq_desc_get_irq(desc);
+	unsigned int irq = desc->irq_data.hwirq;
 	struct keystone_pcie *ks_pcie = irq_desc_get_handler_data(desc);
 	struct dw_pcie *pci = ks_pcie->pci;
 	struct device *dev = pci->dev;
-	u32 irq_offset = irq - ks_pcie->legacy_host_irqs[0];
+	u32 irq_offset = irq - ks_pcie->legacy_host_irq;

 	struct irq_chip *chip = irq_desc_get_chip(desc);
 
 	dev_dbg(dev, ": Handling legacy irq %d\n", irq);

@@ -657,6 +657,7 @@ static int ks_pcie_config_legacy_irq(struct keystone_pcie *ks_pcie)
 	struct device_node *np = ks_pcie->np;
 	struct device_node *intc_np;
 	int irq_count, irq, ret, i;
+	struct irq_data *irq_data;
 
 	intc_np = of_get_child_by_name(np, "legacy-interrupt-controller");
 	if (!intc_np) {

@@ -677,7 +678,15 @@ static int ks_pcie_config_legacy_irq(struct keystone_pcie *ks_pcie)
 			ret = -EINVAL;
 			goto err;
 		}
-		ks_pcie->legacy_host_irqs[i] = irq;
+
+		if (!ks_pcie->legacy_host_irq) {
+			irq_data = irq_get_irq_data(irq);
+			if (!irq_data) {
+				ret = -EINVAL;
+				goto err;
+			}
+			ks_pcie->legacy_host_irq = irq_data->hwirq;