irqchip/loongson-eiointc: Route interrupt parsed from bios table

Interrupt controller eiointc routes interrupts to CPU interface IP0 - IP7.

It is currently hard-coded that eiointc routes interrupts to the CPU
starting from IP1, but it should base that decision on the parent
interrupt, which is provided by ACPI or DTS.

Retrieve the parent's hardware interrupt number and store it in the
descriptor of the eointc instance, so that the routing function can utilize
it for the correct route settings.

[ tglx: Massaged change log ]

Signed-off-by: Bibo Mao <[e-mail]>
Signed-off-by: Thomas Gleixner <[e-mail]>
Link: https://lore.kernel.org/all/[e-mail]

drivers/irqchip/irq-loongson-eiointc.c

···
 	struct fwnode_handle	*domain_handle;
 	struct irq_domain	*eiointc_domain;
 	int			flags;
+	irq_hw_number_t		parent_hwirq;
 };
 
 static struct eiointc_priv *eiointc_priv[MAX_IO_PICS];
···
 		}
 
 		for (i = 0; i < eiointc_priv[0]->vec_count / 32 / 4; i++) {
-			bit = BIT(1 + index); /* Route to IP[1 + index] */
+			/*
+			 * Route to interrupt pin, relative offset used here
+			 * Offset 0 means routing to IP0 and so on
+			 * Every 32 vector routing to one interrupt pin
+			 */
+			bit = BIT(eiointc_priv[index]->parent_hwirq - INT_HWI0);
 			data = bit | (bit << 8) | (bit << 16) | (bit << 24);
 			iocsr_write32(data, EIOINTC_REG_IPMAP + i * 4);
 		}
···
 
 	priv->vec_count = VEC_COUNT;
 	priv->node = acpi_eiointc->node;
-
+	priv->parent_hwirq = acpi_eiointc->cascade;
 	parent_irq = irq_create_mapping(parent, acpi_eiointc->cascade);
 
 	ret = eiointc_init(priv, parent_irq, acpi_eiointc->node_map);
···
 static int __init eiointc_of_init(struct device_node *of_node,
 				  struct device_node *parent)
 {
-	int parent_irq, ret;
 	struct eiointc_priv *priv;
+	struct irq_data *irq_data;
+	int parent_irq, ret;
 
 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 	if (!priv)
···
 	if (ret < 0)
 		goto out_free_priv;
 
+	irq_data = irq_get_irq_data(parent_irq);
+	if (!irq_data) {
+		ret = -ENODEV;
+		goto out_free_priv;
+	}
+
 	/*
 	 * In particular, the number of devices supported by the LS2K0500
 	 * extended I/O interrupt vector is 128.
···
 		priv->vec_count = 128;
 	else
 		priv->vec_count = VEC_COUNT;
-
+	priv->parent_hwirq = irqd_to_hwirq(irq_data);
 	priv->node = 0;
 	priv->domain_handle = of_fwnode_handle(of_node);