irqchip/loongson-htvec: Support 8 groups of HT vectors

The original version can only used by old Loongson-3 which only use 4
groups of HT vectors. Now Loongson-3A R4 can use 8 groups, so improve
the driver to support all 8 groups.

Fixes: 818e915 ("irqchip: Add Loongson HyperTransport Vector support")
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Link: https://lore.kernel.org/r/1596099090-23516-5-git-send-email-chenhc@lemote.com

Author: chenhuacai

drivers/irqchip/irq-loongson-htvec.c

@@ -19,15 +19,14 @@
 
 /* Registers */
 #define HTVEC_EN_OFF		0x20
-#define HTVEC_MAX_PARENT_IRQ	4
+#define HTVEC_MAX_PARENT_IRQ	8
 
 #define VEC_COUNT_PER_REG	32
-#define VEC_REG_COUNT		4
-#define VEC_COUNT		(VEC_COUNT_PER_REG * VEC_REG_COUNT)
 #define VEC_REG_IDX(irq_id)	((irq_id) / VEC_COUNT_PER_REG)
 #define VEC_REG_BIT(irq_id)	((irq_id) % VEC_COUNT_PER_REG)
 
 struct htvec {
+	int			num_parents;
 	void __iomem		*base;
 	struct irq_domain	*htvec_domain;
 	raw_spinlock_t		htvec_lock;
@@ -43,7 +42,7 @@ static void htvec_irq_dispatch(struct irq_desc *desc)
 
 	chained_irq_enter(chip, desc);
 
-	for (i = 0; i < VEC_REG_COUNT; i++) {
+	for (i = 0; i < priv->num_parents; i++) {
 		pending = readl(priv->base + 4 * i);
 		while (pending) {
 			int bit = __ffs(pending);
@@ -150,7 +149,7 @@ static void htvec_reset(struct htvec *priv)
 	u32 idx;
 
 	/* Clear IRQ cause registers, mask all interrupts */
-	for (idx = 0; idx < VEC_REG_COUNT; idx++) {
+	for (idx = 0; idx < priv->num_parents; idx++) {
 		writel_relaxed(0x0, priv->base + HTVEC_EN_OFF + 4 * idx);
 		writel_relaxed(0xFFFFFFFF, priv->base);
 	}
@@ -160,7 +159,7 @@ static int htvec_of_init(struct device_node *node,
 				struct device_node *parent)
 {
 	struct htvec *priv;
-	int err, parent_irq[4], num_parents = 0, i;
+	int err, parent_irq[8], i;
 
 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 	if (!priv)
@@ -179,19 +178,18 @@ static int htvec_of_init(struct device_node *node,
 		if (parent_irq[i] <= 0)
 			break;
 
-		num_parents++;
+		priv->num_parents++;
 	}
 
-	if (!num_parents) {
+	if (!priv->num_parents) {
 		pr_err("Failed to get parent irqs\n");
 		err = -ENODEV;
 		goto iounmap_base;
 	}
 
 	priv->htvec_domain = irq_domain_create_linear(of_node_to_fwnode(node),
-						      VEC_COUNT,
-						      &htvec_domain_ops,
-						      priv);
+					(VEC_COUNT_PER_REG * priv->num_parents),
+					&htvec_domain_ops, priv);
 	if (!priv->htvec_domain) {
 		pr_err("Failed to create IRQ domain\n");
 		err = -ENOMEM;
@@ -200,7 +198,7 @@ static int htvec_of_init(struct device_node *node,
 
 	htvec_reset(priv);
 
-	for (i = 0; i < num_parents; i++)
+	for (i = 0; i < priv->num_parents; i++)
 		irq_set_chained_handler_and_data(parent_irq[i],
 						 htvec_irq_dispatch, priv);