1 files changed, 24 insertions, 17 deletions

diff --git a/arch/arc/kernel/intc-arcv2.c b/arch/arc/kernel/intc-arcv2.c
index 0394f9f61b46..942526322ae7 100644
--- a/arch/arc/kernel/intc-arcv2.c
+++ b/arch/arc/kernel/intc-arcv2.c
@@ -14,6 +14,8 @@
 #include <linux/irqchip.h>
 #include <asm/irq.h>
 
+static int irq_prio;
+
 /*
  * Early Hardware specific Interrupt setup
  * -Called very early (start_kernel -> setup_arch -> setup_processor)
@@ -24,6 +26,14 @@ void arc_init_IRQ(void)
 {
         unsigned int tmp;
 
+        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 aux_irq_ctrl {
 #ifdef CONFIG_CPU_BIG_ENDIAN
                 unsigned int res3:18, save_idx_regs:1, res2:1,
@@ -46,28 +56,25 @@ void arc_init_IRQ(void)
 
         WRITE_AUX(AUX_IRQ_CTRL, ictrl);
 
-        /* setup status32, don't enable intr yet as kernel doesn't want */
-        tmp = read_aux_reg(0xa);
-        tmp |= ISA_INIT_STATUS_BITS;
-        tmp &= ~STATUS_IE_MASK;
-        asm volatile("flag %0   \n"::"r"(tmp));
-
         /*
          * ARCv2 core intc provides multiple interrupt priorities (upto 16).
          * Typical builds though have only two levels (0-high, 1-low)
          * Linux by default uses lower prio 1 for most irqs, reserving 0 for
          * NMI style interrupts in future (say perf)
-         *
-         * Read the intc BCR to confirm that Linux default priority is avail
-         * in h/w
-         *
-         * Note:
-         *  IRQ_BCR[27..24] contains N-1 (for N priority levels) and prio level
-         *  is 0 based.
          */
-        tmp = (read_aux_reg(ARC_REG_IRQ_BCR) >> 24 ) & 0xF;
-        if (ARCV2_IRQ_DEF_PRIO > tmp)
-                panic("Linux default irq prio incorrect\n");
+
+        READ_BCR(ARC_REG_IRQ_BCR, irq_bcr);
+
+        irq_prio = irq_bcr.prio;        /* Encoded as N-1 for N levels */
+        pr_info("archs-intc\t: %d priority levels (default %d)%s\n",
+                irq_prio + 1, irq_prio,
+                irq_bcr.firq ? " FIRQ (not used)":"");
+
+        /* setup status32, don't enable intr yet as kernel doesn't want */
+        tmp = read_aux_reg(0xa);
+        tmp |= STATUS_AD_MASK | (irq_prio << 1);
+        tmp &= ~STATUS_IE_MASK;
+        asm volatile("flag %0   \n"::"r"(tmp));
 }
 
 static void arcv2_irq_mask(struct irq_data *data)
@@ -86,7 +93,7 @@ void arcv2_irq_enable(struct irq_data *data)
 {
         /* set default priority */
         write_aux_reg(AUX_IRQ_SELECT, data->irq);
-        write_aux_reg(AUX_IRQ_PRIORITY, ARCV2_IRQ_DEF_PRIO);
+        write_aux_reg(AUX_IRQ_PRIORITY, irq_prio);
 
         /*
          * hw auto enables (linux unmask) all by default