ARCv2: intc: Use runtime value of irq count for setting up intc

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

2 files changed, 18 insertions, 11 deletions

diff --git a/arch/arc/include/asm/irq.h b/arch/arc/include/asm/irq.h
index a3880b423925..0618b1ce707c 100644
--- a/arch/arc/include/asm/irq.h
+++ b/arch/arc/include/asm/irq.h
@@ -21,6 +21,7 @@
 #ifdef CONFIG_ISA_ARCV2
 #define IPI_IRQ         19
 #define SOFTIRQ_IRQ     21
+#define FIRST_EXT_IRQ   24
 #endif
 
 #include <linux/interrupt.h>
diff --git a/arch/arc/kernel/intc-arcv2.c b/arch/arc/kernel/intc-arcv2.c
index 5c5769dd8f5d..4d3166f9bbc9 100644
--- a/arch/arc/kernel/intc-arcv2.c
+++ b/arch/arc/kernel/intc-arcv2.c
@@ -14,7 +14,15 @@
 #include <linux/irqchip.h>
 #include <asm/irq.h>
 
-#define NR_CPU_IRQS     32      /* number of irq lines coming in */
+#define NR_EXCEPTIONS   16
+
+struct bcr_irq_arcv2 {
+#ifdef CONFIG_CPU_BIG_ENDIAN
+        unsigned int pad:3, firq:1, prio:4, exts:8, irqs:8, ver:8;
+#else
+        unsigned int ver:8, irqs:8, exts:8, prio:4, firq:1, pad:3;
+#endif
+};
 
 /*
  * Early Hardware specific Interrupt setup
@@ -25,14 +33,7 @@
 void arc_init_IRQ(void)
 {
         unsigned int tmp, irq_prio;
-
-        struct irq_build {
-#ifdef CONFIG_CPU_BIG_ENDIAN
-                unsigned int pad:3, firq:1, prio:4, exts:8, irqs:8, ver:8;
-#else
-                unsigned int ver:8, irqs:8, exts:8, prio:4, firq:1, pad:3;
-#endif
-        } irq_bcr;
+        struct bcr_irq_arcv2 irq_bcr;
 
         struct aux_irq_ctrl {
 #ifdef CONFIG_CPU_BIG_ENDIAN
@@ -117,7 +118,7 @@ static int arcv2_irq_map(struct irq_domain *d, unsigned int irq,
          * core intc IRQs [16, 23]:
          * Statically assigned always private-per-core (Timers, WDT, IPI, PCT)
          */
-        if (hw < 24) {
+        if (hw < FIRST_EXT_IRQ) {
                 /*
                  * A subsequent request_percpu_irq() fails if percpu_devid is
                  * not set. That in turns sets NOAUTOEN, meaning each core needs
@@ -142,11 +143,16 @@ static int __init
 init_onchip_IRQ(struct device_node *intc, struct device_node *parent)
 {
         struct irq_domain *root_domain;
+        struct bcr_irq_arcv2 irq_bcr;
+        unsigned int nr_cpu_irqs;
+
+        READ_BCR(ARC_REG_IRQ_BCR, irq_bcr);
+        nr_cpu_irqs = irq_bcr.irqs + NR_EXCEPTIONS;
 
         if (parent)
                 panic("DeviceTree incore intc not a root irq controller\n");
 
-        root_domain = irq_domain_add_linear(intc, NR_CPU_IRQS, &arcv2_irq_ops, NULL);
+        root_domain = irq_domain_add_linear(intc, nr_cpu_irqs, &arcv2_irq_ops, NULL);
         if (!root_domain)
                 panic("root irq domain not avail\n");