[PATCH v4 34/40] MIPS: sgi-ip27: optimize alloc_level()

[Yury Norov <yury.norov@gmail.com>]

Simplify alloc_level by using a dedicated atomic find() API, and make
it a nice one-liner wrappers.

Signed-off-by: Yury Norov <yury.norov@gmail.com>
---
 arch/mips/sgi-ip27/ip27-irq.c | 13 +++----------
 1 file changed, 3 insertions(+), 10 deletions(-)

diff --git a/arch/mips/sgi-ip27/ip27-irq.c b/arch/mips/sgi-ip27/ip27-irq.c
index 00e63e9ef61d..fc29252860a3 100644
--- a/arch/mips/sgi-ip27/ip27-irq.c
+++ b/arch/mips/sgi-ip27/ip27-irq.c
@@ -13,6 +13,7 @@
 #include <linux/ioport.h>
 #include <linux/kernel.h>
 #include <linux/bitops.h>
+#include <linux/find_atomic.h>
 #include <linux/sched.h>
 
 #include <asm/io.h>
@@ -36,17 +37,9 @@ static DEFINE_PER_CPU(unsigned long [2], irq_enable_mask);
 
 static inline int alloc_level(void)
 {
-	int level;
+	int level = find_and_set_bit(hub_irq_map, IP27_HUB_IRQ_COUNT);
 
-again:
-	level = find_first_zero_bit(hub_irq_map, IP27_HUB_IRQ_COUNT);
-	if (level >= IP27_HUB_IRQ_COUNT)
-		return -ENOSPC;
-
-	if (test_and_set_bit(level, hub_irq_map))
-		goto again;
-
-	return level;
+	return level < IP27_HUB_IRQ_COUNT ? level : -ENOSPC;
 }
 
 static void enable_hub_irq(struct irq_data *d)
-- 
2.43.0