[MIPS] Make irq number allocator generally available for fixing EV64120.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

4 files changed, 46 insertions, 25 deletions

diff --git a/arch/mips/kernel/irq.c b/arch/mips/kernel/irq.c
index dd24434392b6..9b0e49d63d7b 100644
--- a/arch/mips/kernel/irq.c
+++ b/arch/mips/kernel/irq.c
@@ -26,6 +26,48 @@
 #include <asm/system.h>
 #include <asm/uaccess.h>
 
+static unsigned long irq_map[NR_IRQS / BITS_PER_LONG];
+
+int __devinit allocate_irqno(void)
+{
+        int irq;
+
+again:
+        irq = find_first_zero_bit(irq_map, NR_IRQS);
+
+        if (irq >= NR_IRQS)
+                return -ENOSPC;
+
+        if (test_and_set_bit(irq, irq_map))
+                goto again;
+
+        return irq;
+}
+
+EXPORT_SYMBOL_GPL(allocate_irqno);
+
+/*
+ * Allocate the 16 legacy interrupts for i8259 devices.  This happens early
+ * in the kernel initialization so treating allocation failure as BUG() is
+ * ok.
+ */
+void __init alloc_legacy_irqno(void)
+{
+        int i;
+
+        for (i = 0; i <= 16; i++)
+                BUG_ON(test_and_set_bit(i, irq_map));
+}
+
+void __devinit free_irqno(unsigned int irq)
+{
+        smp_mb__before_clear_bit();
+        clear_bit(irq, irq_map);
+        smp_mb__after_clear_bit();
+}
+
+EXPORT_SYMBOL_GPL(free_irqno);
+
 /*
  * 'what should we do if we get a hw irq event on an illegal vector'.
  * each architecture has to answer this themselves.
diff --git a/arch/mips/sgi-ip27/ip27-irq.c b/arch/mips/sgi-ip27/ip27-irq.c
index f01ba1f90770..270ecd3e6b4a 100644
--- a/arch/mips/sgi-ip27/ip27-irq.c
+++ b/arch/mips/sgi-ip27/ip27-irq.c
@@ -354,29 +354,6 @@ static struct irq_chip bridge_irq_type = {
         .end            = end_bridge_irq,
 };
 
-static unsigned long irq_map[NR_IRQS / BITS_PER_LONG];
-
-int allocate_irqno(void)
-{
-        int irq;
-
-again:
-        irq = find_first_zero_bit(irq_map, NR_IRQS);
-
-        if (irq >= NR_IRQS)
-                return -ENOSPC;
-
-        if (test_and_set_bit(irq, irq_map))
-                goto again;
-
-        return irq;
-}
-
-void free_irqno(unsigned int irq)
-{
-        clear_bit(irq, irq_map);
-}
-
 void __devinit register_bridge_irq(unsigned int irq)
 {
         irq_desc[irq].status    = IRQ_DISABLED;
diff --git a/arch/mips/sgi-ip27/ip27-timer.c b/arch/mips/sgi-ip27/ip27-timer.c
index c965705f3427..5e82a268e3c9 100644
--- a/arch/mips/sgi-ip27/ip27-timer.c
+++ b/arch/mips/sgi-ip27/ip27-timer.c
@@ -214,8 +214,6 @@ static struct irqaction rt_irqaction = {
         .name           = "timer"
 };
 
-extern int allocate_irqno(void);
-
 void __init plat_timer_setup(struct irqaction *irq)
 {
         int irqno  = allocate_irqno();
diff --git a/include/asm-mips/irq.h b/include/asm-mips/irq.h
index 0ce2a80b689e..35a05ca5560c 100644
--- a/include/asm-mips/irq.h
+++ b/include/asm-mips/irq.h
@@ -74,4 +74,8 @@ extern int setup_irq_smtc(unsigned int irq, struct irqaction * new,
                           unsigned long hwmask);
 #endif /* CONFIG_MIPS_MT_SMTC */
 
+extern int allocate_irqno(void);
+extern void alloc_legacy_irqno(void);
+extern void free_irqno(unsigned int irq);
+
 #endif /* _ASM_IRQ_H */