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

Marc Zyngier
2022-02-16T09:09:04Z

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