IXP42x: Use __fls() in QMgr interrupt handlers.

Signed-off-by: Krzysztof Hałasa <khc@pm.waw.pl>

1 files changed, 20 insertions, 15 deletions

diff --git a/arch/arm/mach-ixp4xx/ixp4xx_qmgr.c b/arch/arm/mach-ixp4xx/ixp4xx_qmgr.c
index 6e6dc4c78a10..bfdbe4b5a3cc 100644
--- a/arch/arm/mach-ixp4xx/ixp4xx_qmgr.c
+++ b/arch/arm/mach-ixp4xx/ixp4xx_qmgr.c
@@ -52,14 +52,15 @@ void qmgr_set_irq(unsigned int queue, int src,
 static irqreturn_t qmgr_irq1_a0(int irq, void *pdev)
 {
         int i, ret = 0;
+        u32 en_bitmap, src, stat;
 
         /* ACK - it may clear any bits so don't rely on it */
         __raw_writel(0xFFFFFFFF, &qmgr_regs->irqstat[0]);
 
-        for (i = 0; i < HALF_QUEUES; i++) {
-                u32 src, stat;
-                if (!(qmgr_regs->irqen[0] & BIT(i)))
-                        continue;
+        en_bitmap = qmgr_regs->irqen[0];
+        while (en_bitmap) {
+                i = __fls(en_bitmap); /* number of the last "low" queue */
+                en_bitmap &= ~BIT(i);
                 src = qmgr_regs->irqsrc[i >> 3];
                 stat = qmgr_regs->stat1[i >> 3];
                 if (src & 4) /* the IRQ condition is inverted */
@@ -82,9 +83,9 @@ static irqreturn_t qmgr_irq2_a0(int irq, void *pdev)
         __raw_writel(0xFFFFFFFF, &qmgr_regs->irqstat[1]);
 
         req_bitmap = qmgr_regs->irqen[1] & qmgr_regs->statne_h;
-        for (i = 0; i < HALF_QUEUES; i++) {
-                if (!(req_bitmap & BIT(i)))
-                        continue;
+        while (req_bitmap) {
+                i = __fls(req_bitmap); /* number of the last "high" queue */
+                req_bitmap &= ~BIT(i);
                 irq_handlers[HALF_QUEUES + i](irq_pdevs[HALF_QUEUES + i]);
                 ret = IRQ_HANDLED;
         }
@@ -95,15 +96,19 @@ static irqreturn_t qmgr_irq2_a0(int irq, void *pdev)
 static irqreturn_t qmgr_irq(int irq, void *pdev)
 {
         int i, half = (irq == IRQ_IXP4XX_QM1 ? 0 : 1);
-        u32 val = __raw_readl(&qmgr_regs->irqstat[half]);
-        __raw_writel(val, &qmgr_regs->irqstat[half]); /* ACK */
+        u32 req_bitmap = __raw_readl(&qmgr_regs->irqstat[half]);
 
-        for (i = 0; i < HALF_QUEUES; i++)
-                if (val & (1 << i)) {
-                        int irq = half * HALF_QUEUES + i;
-                        irq_handlers[irq](irq_pdevs[irq]);
-                }
-        return val ? IRQ_HANDLED : 0;
+        if (!req_bitmap)
+                return 0;
+        __raw_writel(req_bitmap, &qmgr_regs->irqstat[half]); /* ACK */
+
+        while (req_bitmap) {
+                i = __fls(req_bitmap); /* number of the last queue */
+                req_bitmap &= ~BIT(i);
+                i += half * HALF_QUEUES;
+                irq_handlers[i](irq_pdevs[i]);
+        }
+        return IRQ_HANDLED;
 }