irqchip/gic: Kconfig the number of instances

There is currently a hack in the GIC driver making it possible
to pass the number of GIC instances from the platform-specific
include files and thus override the variable MAX_GIC_NR.

With multiplatform deployments, this will not work as we need
to get rid of the platform-specific include files.

It turns out that this feature is only used by the RealView
platform which has a cascaded GIC. So move the configuration
to Kconfig and bump to 2 instances if we're building for the
RealView. The include file hacks can then be removed.

Tested on the ARM PB11MPCore with its cascaded GIC.
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

drivers/irqchip/Kconfig

@@ -8,6 +8,11 @@ config ARM_GIC
 	select IRQ_DOMAIN_HIERARCHY
 	select MULTI_IRQ_HANDLER
 
+config ARM_GIC_MAX_NR
+	int
+	default 2 if ARCH_REALVIEW
+	default 1
+
 config ARM_GIC_V2M
 	bool
 	depends on ARM_GIC

drivers/irqchip/irq-gic.c

@@ -100,11 +100,7 @@ static u8 gic_cpu_map[NR_GIC_CPU_IF] __read_mostly;
 
 static struct static_key supports_deactivate = STATIC_KEY_INIT_TRUE;
 
-#ifndef MAX_GIC_NR
-#define MAX_GIC_NR	1
-#endif
-
-static struct gic_chip_data gic_data[MAX_GIC_NR] __read_mostly;
+static struct gic_chip_data gic_data[CONFIG_ARM_GIC_MAX_NR] __read_mostly;
 
 #ifdef CONFIG_GIC_NON_BANKED
 static void __iomem *gic_get_percpu_base(union gic_base *base)
@@ -417,8 +413,7 @@ static struct irq_chip gic_eoimode1_chip = {
 
 void __init gic_cascade_irq(unsigned int gic_nr, unsigned int irq)
 {
-	if (gic_nr >= MAX_GIC_NR)
-		BUG();
+	BUG_ON(gic_nr >= CONFIG_ARM_GIC_MAX_NR);
 	irq_set_chained_handler_and_data(irq, gic_handle_cascade_irq,
 					 &gic_data[gic_nr]);
 }
@@ -524,7 +519,7 @@ int gic_cpu_if_down(unsigned int gic_nr)
 	void __iomem *cpu_base;
 	u32 val = 0;
 
-	if (gic_nr >= MAX_GIC_NR)
+	if (gic_nr >= CONFIG_ARM_GIC_MAX_NR)
 		return -EINVAL;
 
 	cpu_base = gic_data_cpu_base(&gic_data[gic_nr]);
@@ -548,8 +543,7 @@ static void gic_dist_save(unsigned int gic_nr)
 	void __iomem *dist_base;
 	int i;
 
-	if (gic_nr >= MAX_GIC_NR)
-		BUG();
+	BUG_ON(gic_nr >= CONFIG_ARM_GIC_MAX_NR);
 
 	gic_irqs = gic_data[gic_nr].gic_irqs;
 	dist_base = gic_data_dist_base(&gic_data[gic_nr]);
@@ -587,8 +581,7 @@ static void gic_dist_restore(unsigned int gic_nr)
 	unsigned int i;
 	void __iomem *dist_base;
 
-	if (gic_nr >= MAX_GIC_NR)
-		BUG();
+	BUG_ON(gic_nr >= CONFIG_ARM_GIC_MAX_NR);
 
 	gic_irqs = gic_data[gic_nr].gic_irqs;
 	dist_base = gic_data_dist_base(&gic_data[gic_nr]);
@@ -634,8 +627,7 @@ static void gic_cpu_save(unsigned int gic_nr)
 	void __iomem *dist_base;
 	void __iomem *cpu_base;
 
-	if (gic_nr >= MAX_GIC_NR)
-		BUG();
+	BUG_ON(gic_nr >= CONFIG_ARM_GIC_MAX_NR);
 
 	dist_base = gic_data_dist_base(&gic_data[gic_nr]);
 	cpu_base = gic_data_cpu_base(&gic_data[gic_nr]);
@@ -664,8 +656,7 @@ static void gic_cpu_restore(unsigned int gic_nr)
 	void __iomem *dist_base;
 	void __iomem *cpu_base;
 
-	if (gic_nr >= MAX_GIC_NR)
-		BUG();
+	BUG_ON(gic_nr >= CONFIG_ARM_GIC_MAX_NR);
 
 	dist_base = gic_data_dist_base(&gic_data[gic_nr]);
 	cpu_base = gic_data_cpu_base(&gic_data[gic_nr]);
@@ -703,7 +694,7 @@ static int gic_notifier(struct notifier_block *self, unsigned long cmd,	void *v)
 {
 	int i;
 
-	for (i = 0; i < MAX_GIC_NR; i++) {
+	for (i = 0; i < CONFIG_ARM_GIC_MAX_NR; i++) {
 #ifdef CONFIG_GIC_NON_BANKED
 		/* Skip over unused GICs */
 		if (!gic_data[i].get_base)
@@ -835,8 +826,7 @@ void gic_migrate_target(unsigned int new_cpu_id)
 	int i, ror_val, cpu = smp_processor_id();
 	u32 val, cur_target_mask, active_mask;
 
-	if (gic_nr >= MAX_GIC_NR)
-		BUG();
+	BUG_ON(gic_nr >= CONFIG_ARM_GIC_MAX_NR);
 
 	dist_base = gic_data_dist_base(&gic_data[gic_nr]);
 	if (!dist_base)
@@ -1035,7 +1025,7 @@ static void __init __gic_init_bases(unsigned int gic_nr, int irq_start,
 	struct gic_chip_data *gic;
 	int gic_irqs, irq_base, i;
 
-	BUG_ON(gic_nr >= MAX_GIC_NR);
+	BUG_ON(gic_nr >= CONFIG_ARM_GIC_MAX_NR);
 
 	gic_check_cpu_features();