[RFC PATCH 1/6] DRIVERS: IRQCHIP: IRQ-GIC: Add support for routable irqs

Hi Thomas,

Thanks a lot for reviewing this.

On Thursday 24 October 2013 02:42 PM, Thomas Gleixner wrote:

On Mon, 30 Sep 2013, Sricharan R wrote:

quoted

diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
index 1760ceb..c5778ab 100644
--- a/drivers/irqchip/irq-gic.c
+++ b/drivers/irqchip/irq-gic.c

@@ -72,6 +72,8 @@ struct gic_chip_data {
 
 static DEFINE_RAW_SPINLOCK(irq_controller_lock);
 
+const struct irq_domain_ops *gic_routable_irq_domain_ops;
+
 /*
  * The GIC mapping of CPU interfaces does not necessarily match
  * the logical CPU numbering.  Let's use a mapping as returned

@@ -675,11 +677,26 @@ static int gic_irq_domain_map(struct irq_domain *d, unsigned int irq,
 		irq_set_chip_and_handler(irq, &gic_chip,
 					 handle_fasteoi_irq);
 		set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
+
+		if (gic_routable_irq_domain_ops &&
+		    gic_routable_irq_domain_ops->map)
+			gic_routable_irq_domain_ops->map(d, irq, hw);

Shudder. Why are you sprinkling these if (ops && ops->fun)
conditionals all over the place instead of having a default ops
implementation which handles the non crossbar case by proper empty
functions. That code is not on a hot path so it does not matter at
all.

 Ok, Understand. Will add default ops to avoid these checks.

quoted

 	}
 	irq_set_chip_data(irq, d->host_data);
 	return 0;
 }
 
+static void gic_irq_domain_unmap(struct irq_domain *d, unsigned int irq)
+{
+	irq_hw_number_t hw = irq_get_irq_data(irq)->hwirq;
+
+	if (hw > 32) {

Groan. This wants to be in the ops->unmap function. It's not related
to the GIC core code.

 Ok, will move this to unmap ops of the crossbar.

quoted

+		if (gic_routable_irq_domain_ops &&
+		    gic_routable_irq_domain_ops->unmap)
+			gic_routable_irq_domain_ops->unmap(d, irq);
+	}
+}
+
 static int gic_irq_domain_xlate(struct irq_domain *d,
 				struct device_node *controller,
 				const u32 *intspec, unsigned int intsize,

@@ -694,8 +711,15 @@ static int gic_irq_domain_xlate(struct irq_domain *d,
 	*out_hwirq = intspec[1] + 16;
 
 	/* For SPIs, we need to add 16 more to get the GIC irq ID number */
-	if (!intspec[0])
-		*out_hwirq += 16;
+	if (!intspec[0]) {
+		if (gic_routable_irq_domain_ops &&
+		    gic_routable_irq_domain_ops->xlate)
+			*out_hwirq = gic_routable_irq_domain_ops->xlate(d,
+						controller, intspec, intsize,
+						out_hwirq, out_type);
+		else
+			*out_hwirq += 16;
+	}

So if you have a default xlate ops implementation then this boils down to

      if (!intspec[0])
		*out_hwirq = routing_ops->xlate()

And the default (non crossbar) implementation would be:

    	return *out_hwirq + 16;
    

 Ok. This is better. Will change here.


Regards,
 Sricharan