[PATCH v4 10/12] PCI: mvebu: Fix macro names and comments about legacy interrupts

Pali Rohár
2022-02-22T15:56:58Z

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

Signed-off-by: Pali Rohár <pali@kernel.org>
---
drivers/pci/controller/pci-mvebu.c | 26 ++++++++++++++++++--------
1 file changed, 18 insertions(+), 8 deletions(-)

diff --git a/drivers/pci/controller/pci-mvebu.c b/drivers/pci/controller/pci-mvebu.c
index 1ae7718a2e3e..d096289035bc 100644
--- a/drivers/pci/controller/pci-mvebu.c
+++ b/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);