Re: [PATCH 4/9] sh: intc: Drop the use of irq_create_identity_mapping()

On Tue, 06 Apr 2021 11:32:13 +0100,
Geert Uytterhoeven [off-list ref] wrote:

Hi Marc,

On Tue, Apr 6, 2021 at 11:44 AM Marc Zyngier [off-list ref] wrote:

quoted

Instead of playing games with using irq_create_identity_mapping()
and irq_domain_associate(), drop the use of the former and only
use the latter, together with the allocation of the irq_desc
as needed.

It doesn't make the code less awful, but at least the intent
is clearer.

Signed-off-by: Marc Zyngier <maz@kernel.org>

Thanks for your patch!

quoted

--- a/drivers/sh/intc/core.c
+++ b/drivers/sh/intc/core.c

@@ -179,6 +179,23 @@ static unsigned int __init save_reg(struct intc_desc_int *d,
        return 0;
 }

+static bool __init intc_map(struct irq_domain *domain, int irq)
+{
+       int res;

warning: unused variable ‘res’ [-Wunused-variable]

quoted

+
+       if (!irq_to_desc(irq) && irq_alloc_desc_at(irq, NUMA_NO_NODE) != irq) {
+               pr_err("uname to allocate IRQ %d\n", irq);
+               return false;
+       }
+
+       if (irq_domain_associate(domain, irq, irq)) {
+               pr_err("domain association failure\n");
+               return false;
+       }
+
+       return true;
+}
+
 int __init register_intc_controller(struct intc_desc *desc)
 {
        unsigned int i, k, smp;

@@ -316,19 +333,8 @@ int __init register_intc_controller(struct intc_desc *desc)

warning: unused variable ‘res’ [-Wunused-variable]

Ah, thanks for spotting these.

quoted

                if (!vect->enum_id)
                        continue;

-               res = irq_create_identity_mapping(d->domain, irq);

quoted

-               if (unlikely(res)) {
-                       if (res == -EEXIST) {
-                               res = irq_domain_associate(d->domain, irq, irq);
-                               if (unlikely(res)) {
-                                       pr_err("domain association failure\n");
-                                       continue;
-                               }
-                       } else {
-                               pr_err("can't identity map IRQ %d\n", irq);
-                               continue;
-                       }
-               }
+               if (!intc_map(d->domain, irq))
+                       continue;

                intc_irq_xlate_set(irq, vect->enum_id, d);
                intc_register_irq(desc, d, vect->enum_id, irq);

Otherwise this seems to work fine on real hardware (landisk) and qemu
(rts7751r2d).  I did verify that the new function intc_map() is called.

Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>

Awesome, thanks Geert.

	M.

-- 
Without deviation from the norm, progress is not possible.