[PATCH 17/25] irqchip/armada-370-xp: Refactor mpic_handle_msi_irq() code

["Marek Behún" <kabel@kernel.org>]

Refactor the mpic_handle_msi_irq() function to make it simpler:
- use for_each_set_bit()
- rename the variable holding the doorbell cause register to cause

Signed-off-by: Marek Behún <kabel@kernel.org>
---
 drivers/irqchip/irq-armada-370-xp.c | 23 +++++++----------------
 1 file changed, 7 insertions(+), 16 deletions(-)

diff --git a/drivers/irqchip/irq-armada-370-xp.c b/drivers/irqchip/irq-armada-370-xp.c
index d8db46001961..9e8b189da1d1 100644
--- a/drivers/irqchip/irq-armada-370-xp.c
+++ b/drivers/irqchip/irq-armada-370-xp.c
@@ -618,24 +618,15 @@ static const struct irq_domain_ops mpic_irq_ops = {
 #ifdef CONFIG_PCI_MSI
 static void mpic_handle_msi_irq(struct pt_regs *regs, bool is_chained)
 {
-	u32 msimask, msinr;
+	unsigned long cause, nr;
 
-	msimask = readl_relaxed(per_cpu_int_base + MPIC_IN_DRBEL_CAUSE);
-	msimask &= msi_doorbell_mask();
+	cause = readl_relaxed(per_cpu_int_base + MPIC_IN_DRBEL_CAUSE);
+	cause &= msi_doorbell_mask();
+	writel(~cause, per_cpu_int_base + MPIC_IN_DRBEL_CAUSE);
 
-	writel(~msimask, per_cpu_int_base + MPIC_IN_DRBEL_CAUSE);
-
-	for (msinr = msi_doorbell_start();
-	     msinr < msi_doorbell_end(); msinr++) {
-		unsigned int irq;
-
-		if (!(msimask & BIT(msinr)))
-			continue;
-
-		irq = msinr - msi_doorbell_start();
-
-		generic_handle_domain_irq(mpic_msi_inner_domain, irq);
-	}
+	for_each_set_bit(nr, &cause, BITS_PER_LONG)
+		generic_handle_domain_irq(mpic_msi_inner_domain,
+					  nr - msi_doorbell_start());
 }
 #else
 static void mpic_handle_msi_irq(struct pt_regs *r, bool b) {}
-- 
2.44.2