PCI: keystone: Cleanup ks_pcie_msi_irq_handler()

ks_pcie_msi_irq_handler() invokes ks_pcie_handle_msi_irq() for handling
the interrupts.

Having two functions for handling the interrupt was used when keystone
PCIe driver was implemented using two files but with commit b492aca3
("PCI: keystone: Merge pci-keystone-dw.c and pci-keystone.c"), which
merged the keystone PCIe driver to use a single file, two functions for
handling the interrupt handler are not required.

Handle MSI interrupt in a single interrupt handler here.
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

drivers/pci/controller/dwc/pci-keystone.c

@@ -105,13 +105,6 @@ struct keystone_pcie {
 	struct resource		app;
 };
 
-static inline void update_reg_offset_bit_pos(u32 offset, u32 *reg_offset,
-					     u32 *bit_pos)
-{
-	*reg_offset = offset % 8;
-	*bit_pos = offset >> 3;
-}
-
 static phys_addr_t ks_pcie_get_msi_addr(struct pcie_port *pp)
 {
 	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
@@ -131,31 +124,6 @@ static void ks_pcie_app_writel(struct keystone_pcie *ks_pcie, u32 offset,
 	writel(val, ks_pcie->va_app_base + offset);
 }
 
-static void ks_pcie_handle_msi_irq(struct keystone_pcie *ks_pcie, int offset)
-{
-	struct dw_pcie *pci = ks_pcie->pci;
-	struct pcie_port *pp = &pci->pp;
-	struct device *dev = pci->dev;
-	u32 pending, vector;
-	int src, virq;
-
-	pending = ks_pcie_app_readl(ks_pcie, MSI_IRQ_STATUS(offset));
-
-	/*
-	 * MSI0 status bit 0-3 shows vectors 0, 8, 16, 24, MSI1 status bit
-	 * shows 1, 9, 17, 25 and so forth
-	 */
-	for (src = 0; src < 4; src++) {
-		if (BIT(src) & pending) {
-			vector = offset + (src << 3);
-			virq = irq_linear_revmap(pp->irq_domain, vector);
-			dev_dbg(dev, "irq: bit %d, vector %d, virq %d\n",
-				src, vector, virq);
-			generic_handle_irq(virq);
-		}
-	}
-}
-
 static void ks_pcie_msi_irq_ack(int irq, struct pcie_port *pp)
 {
 	u32 reg_offset, bit_pos;
@@ -164,7 +132,9 @@ static void ks_pcie_msi_irq_ack(int irq, struct pcie_port *pp)
 
 	pci = to_dw_pcie_from_pp(pp);
 	ks_pcie = to_keystone_pcie(pci);
-	update_reg_offset_bit_pos(irq, &reg_offset, &bit_pos);
+
+	reg_offset = irq % 8;
+	bit_pos = irq >> 3;
 
 	ks_pcie_app_writel(ks_pcie, MSI_IRQ_STATUS(reg_offset),
 			   BIT(bit_pos));
@@ -177,7 +147,9 @@ static void ks_pcie_msi_set_irq(struct pcie_port *pp, int irq)
 	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
 	struct keystone_pcie *ks_pcie = to_keystone_pcie(pci);
 
-	update_reg_offset_bit_pos(irq, &reg_offset, &bit_pos);
+	reg_offset = irq % 8;
+	bit_pos = irq >> 3;
+
 	ks_pcie_app_writel(ks_pcie, MSI_IRQ_ENABLE_SET(reg_offset),
 			   BIT(bit_pos));
 }
@@ -188,7 +160,9 @@ static void ks_pcie_msi_clear_irq(struct pcie_port *pp, int irq)
 	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
 	struct keystone_pcie *ks_pcie = to_keystone_pcie(pci);
 
-	update_reg_offset_bit_pos(irq, &reg_offset, &bit_pos);
+	reg_offset = irq % 8;
+	bit_pos = irq >> 3;
+
 	ks_pcie_app_writel(ks_pcie, MSI_IRQ_ENABLE_CLR(reg_offset),
 			   BIT(bit_pos));
 }
@@ -556,8 +530,10 @@ static void ks_pcie_msi_irq_handler(struct irq_desc *desc)
 	struct keystone_pcie *ks_pcie = irq_desc_get_handler_data(desc);
 	u32 offset = irq - ks_pcie->msi_host_irq;
 	struct dw_pcie *pci = ks_pcie->pci;
+	struct pcie_port *pp = &pci->pp;
 	struct device *dev = pci->dev;
 	struct irq_chip *chip = irq_desc_get_chip(desc);
+	u32 vector, virq, reg, pos;
 
 	dev_dbg(dev, "%s, irq %d\n", __func__, irq);
 
@@ -567,7 +543,23 @@ static void ks_pcie_msi_irq_handler(struct irq_desc *desc)
 	 * ack operation.
 	 */
 	chained_irq_enter(chip, desc);
-	ks_pcie_handle_msi_irq(ks_pcie, offset);
+
+	reg = ks_pcie_app_readl(ks_pcie, MSI_IRQ_STATUS(offset));
+	/*
+	 * MSI0 status bit 0-3 shows vectors 0, 8, 16, 24, MSI1 status bit
+	 * shows 1, 9, 17, 25 and so forth
+	 */
+	for (pos = 0; pos < 4; pos++) {
+		if (!(reg & BIT(pos)))
+			continue;
+
+		vector = offset + (pos << 3);
+		virq = irq_linear_revmap(pp->irq_domain, vector);
+		dev_dbg(dev, "irq: bit %d, vector %d, virq %d\n", pos, vector,
+			virq);
+		generic_handle_irq(virq);
+	}
+
 	chained_irq_exit(chip, desc);
 }