PCI: apple: Move away from INTMSK{SET,CLR} for INTx and private interrupts

T602x seems to have dropped the rather useful SET/CLR accessors
to the masking register.

Instead, let's use the mask register directly, and wrap it with
a brand new spinlock. No, this isn't moving in the right direction.

Signed-off-by: Marc Zyngier <[email protected]>
Signed-off-by: Manivannan Sadhasivam <[email protected]>
Tested-by: Janne Grunau <[email protected]>
Reviewed-by: Rob Herring (Arm) <[email protected]>
Reviewed-by: Manivannan Sadhasivam <[email protected]>
Acked-by: Alyssa Rosenzweig <[email protected]>
Link: https://patch.msgid.link/[email protected]

Author: Marc Zyngier

drivers/pci/controller/pcie-apple.c

@@ -142,6 +142,7 @@ struct apple_pcie {
 };
 
 struct apple_pcie_port {
+	raw_spinlock_t		lock;
 	struct apple_pcie	*pcie;
 	struct device_node	*np;
 	void __iomem		*base;
@@ -261,14 +262,16 @@ static void apple_port_irq_mask(struct irq_data *data)
 {
 	struct apple_pcie_port *port = irq_data_get_irq_chip_data(data);
 
-	writel_relaxed(BIT(data->hwirq), port->base + PORT_INTMSKSET);
+	guard(raw_spinlock_irqsave)(&port->lock);
+	rmw_set(BIT(data->hwirq), port->base + PORT_INTMSK);
 }
 
 static void apple_port_irq_unmask(struct irq_data *data)
 {
 	struct apple_pcie_port *port = irq_data_get_irq_chip_data(data);
 
-	writel_relaxed(BIT(data->hwirq), port->base + PORT_INTMSKCLR);
+	guard(raw_spinlock_irqsave)(&port->lock);
+	rmw_clear(BIT(data->hwirq), port->base + PORT_INTMSK);
 }
 
 static bool hwirq_is_intx(unsigned int hwirq)
@@ -387,7 +390,7 @@ static int apple_pcie_port_setup_irq(struct apple_pcie_port *port)
 		return -ENOMEM;
 
 	/* Disable all interrupts */
-	writel_relaxed(~0, port->base + PORT_INTMSKSET);
+	writel_relaxed(~0, port->base + PORT_INTMSK);
 	writel_relaxed(~0, port->base + PORT_INTSTAT);
 
 	irq_set_chained_handler_and_data(irq, apple_port_irq_handler, port);
@@ -537,6 +540,8 @@ static int apple_pcie_setup_port(struct apple_pcie *pcie,
 	port->pcie = pcie;
 	port->np = np;
 
+	raw_spin_lock_init(&port->lock);
+
 	port->base = devm_platform_ioremap_resource(platform, port->idx + 2);
 	if (IS_ERR(port->base))
 		return PTR_ERR(port->base);