[PATCH 1/2] genirq: Extract irq_set_affinity_masks() from devm_platform_get_irqs_affinity()

[Marc Zyngier <maz@kernel.org>]

In order to better support drivers that deal with interrupts in a more
"hands-on" way, extract the core of devm_platform_get_irqs_affinity()
and expose it as irq_set_affinity_masks().

This helper allows a driver to provide a set of wired interrupts that
are to be configured as managed interrupts. As with the original helper,
this is exported as EXPORT_SYMBOL_GPL.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 drivers/base/platform.c   | 20 +++-----------------
 include/linux/interrupt.h |  8 ++++++++
 kernel/irq/affinity.c     | 27 +++++++++++++++++++++++++++
 3 files changed, 38 insertions(+), 17 deletions(-)

diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index 6cb04ac48bf0..b363cf6ce5be 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -335,7 +335,6 @@ int devm_platform_get_irqs_affinity(struct platform_device *dev,
 				    int **irqs)
 {
 	struct irq_affinity_devres *ptr;
-	struct irq_affinity_desc *desc;
 	size_t size;
 	int i, ret, nvec;
 
@@ -376,31 +375,18 @@ int devm_platform_get_irqs_affinity(struct platform_device *dev,
 		ptr->irq[i] = irq;
 	}
 
-	desc = irq_create_affinity_masks(nvec, affd);
-	if (!desc) {
-		ret = -ENOMEM;
+	ret = irq_set_affinity_masks(affd, ptr->irq, nvec);
+	if (ret) {
+		dev_err(&dev->dev, "failed to update affinity descriptors (%d)\n", ret);
 		goto err_free_devres;
 	}
 
-	for (i = 0; i < nvec; i++) {
-		ret = irq_update_affinity_desc(ptr->irq[i], &desc[i]);
-		if (ret) {
-			dev_err(&dev->dev, "failed to update irq%d affinity descriptor (%d)\n",
-				ptr->irq[i], ret);
-			goto err_free_desc;
-		}
-	}
-
 	devres_add(&dev->dev, ptr);
 
-	kfree(desc);
-
 	*irqs = ptr->irq;
 
 	return nvec;
 
-err_free_desc:
-	kfree(desc);
 err_free_devres:
 	devres_free(ptr);
 	return ret;
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index 9367f1cb2e3c..6bfce96206f8 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -381,6 +381,8 @@ irq_create_affinity_masks(unsigned int nvec, struct irq_affinity *affd);
 unsigned int irq_calc_affinity_vectors(unsigned int minvec, unsigned int maxvec,
 				       const struct irq_affinity *affd);
 
+int irq_set_affinity_masks(struct irq_affinity *affd, int *irqs, int nvec);
+
 #else /* CONFIG_SMP */
 
 static inline int irq_set_affinity(unsigned int irq, const struct cpumask *m)
@@ -443,6 +445,12 @@ irq_calc_affinity_vectors(unsigned int minvec, unsigned int maxvec,
 	return maxvec;
 }
 
+static inline int
+irq_set_affinity_masks(struct irq_affinity *affd, int *irqs, int nvec)
+{
+	return -EINVAL;
+}
+
 #endif /* CONFIG_SMP */
 
 /*
diff --git a/kernel/irq/affinity.c b/kernel/irq/affinity.c
index f7ff8919dc9b..c0f868cd5b87 100644
--- a/kernel/irq/affinity.c
+++ b/kernel/irq/affinity.c
@@ -512,3 +512,30 @@ unsigned int irq_calc_affinity_vectors(unsigned int minvec, unsigned int maxvec,
 
 	return resv + min(set_vecs, maxvec - resv);
 }
+
+/*
+ * irq_set_affinity_masks - Set the affinity masks of a number of interrupts
+ *                          for multiqueue spreading
+ * @affd:	Description of the affinity requirements
+ * @irqs:	An array of interrupt numbers
+ * @nvec:	The total number of interrupts
+ */
+int irq_set_affinity_masks(struct irq_affinity *affd, int *irqs, int nvec)
+{
+	struct irq_affinity_desc *desc;
+	int i, err = 0;
+
+	desc = irq_create_affinity_masks(nvec, affd);
+	if (!desc)
+		return -ENOMEM;
+
+	for (i = 0; i < nvec; i++) {
+		err = irq_update_affinity_desc(irqs[i], desc + i);
+		if (err)
+			break;
+	}
+
+	kfree(desc);
+	return err;
+}
+EXPORT_SYMBOL_GPL(irq_set_affinity_masks);
-- 
2.30.2