PCI: mvebu: Fix macro names and comments about legacy interrupts

Register 0x1910 unmasks interrupts and legacy INTx interrupts are unmasked
because driver does not support individual masking yet.

Link: https://lore.kernel.org/r/20220222155030.988-11-pali@kernel.orgSigned-off-by: NPali Rohár <pali@kernel.org>
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>

drivers/pci/controller/pci-mvebu.c

@@ -54,9 +54,10 @@
 	 PCIE_CONF_ADDR_EN)
 #define PCIE_CONF_DATA_OFF	0x18fc
 #define PCIE_INT_CAUSE_OFF	0x1900
+#define PCIE_INT_UNMASK_OFF	0x1910
+#define  PCIE_INT_INTX(i)		BIT(24+i)
 #define  PCIE_INT_PM_PME		BIT(28)
-#define PCIE_MASK_OFF		0x1910
-#define  PCIE_MASK_ENABLE_INTS          0x0f000000
+#define  PCIE_INT_ALL_MASK		GENMASK(31, 0)
 #define PCIE_CTRL_OFF		0x1a00
 #define  PCIE_CTRL_X1_MODE		0x0001
 #define  PCIE_CTRL_RC_MODE		BIT(1)
@@ -235,7 +236,7 @@ static void mvebu_pcie_setup_wins(struct mvebu_pcie_port *port)
 
 static void mvebu_pcie_setup_hw(struct mvebu_pcie_port *port)
 {
-	u32 ctrl, lnkcap, cmd, dev_rev, mask;
+	u32 ctrl, lnkcap, cmd, dev_rev, unmask;
 
 	/* Setup PCIe controller to Root Complex mode. */
 	ctrl = mvebu_readl(port, PCIE_CTRL_OFF);
@@ -288,10 +289,19 @@ static void mvebu_pcie_setup_hw(struct mvebu_pcie_port *port)
 	/* Point PCIe unit MBUS decode windows to DRAM space. */
 	mvebu_pcie_setup_wins(port);
 
-	/* Enable interrupt lines A-D. */
-	mask = mvebu_readl(port, PCIE_MASK_OFF);
-	mask |= PCIE_MASK_ENABLE_INTS;
-	mvebu_writel(port, mask, PCIE_MASK_OFF);
+	/*
+	 * Unmask all legacy INTx interrupts as driver does not provide a way
+	 * for masking and unmasking of individual legacy INTx interrupts.
+	 * Legacy INTx are reported via one shared GIC source and therefore
+	 * kernel cannot distinguish which individual legacy INTx was triggered.
+	 * These interrupts are shared, so it should not cause any issue. Just
+	 * performance penalty as every PCIe interrupt handler needs to be
+	 * called when some interrupt is triggered.
+	 */
+	unmask = mvebu_readl(port, PCIE_INT_UNMASK_OFF);
+	unmask |= PCIE_INT_INTX(0) | PCIE_INT_INTX(1) |
+		  PCIE_INT_INTX(2) | PCIE_INT_INTX(3);
+	mvebu_writel(port, unmask, PCIE_INT_UNMASK_OFF);
 }
 
 static struct mvebu_pcie_port *mvebu_pcie_find_port(struct mvebu_pcie *pcie,
@@ -1450,7 +1460,7 @@ static int mvebu_pcie_remove(struct platform_device *pdev)
 		mvebu_writel(port, cmd, PCIE_CMD_OFF);
 
 		/* Mask all interrupt sources. */
-		mvebu_writel(port, 0, PCIE_MASK_OFF);
+		mvebu_writel(port, ~PCIE_INT_ALL_MASK, PCIE_INT_UNMASK_OFF);
 
 		/* Free config space for emulated root bridge. */
 		pci_bridge_emul_cleanup(&port->bridge);