[PATCH v2 04/25] platform: Add firmware-agnostic irq and affinity retrieval interface
From: Marc Zyngier <maz@kernel.org>
Date: 2025-09-15 08:57:14
Also in:
linux-acpi, lkml
Subsystem:
driver core, kobjects, debugfs and sysfs, the rest · Maintainers:
Greg Kroah-Hartman, "Rafael J. Wysocki", Danilo Krummrich, Linus Torvalds
Expand platform_get_irq_optional() to also return an affinity if available, renaming it to platform_get_irq_affinity() in the process. platform_get_irq_optional() is preserved with its current semantics by calling into the new helper with a NULL affinity pointer. Signed-off-by: Marc Zyngier <maz@kernel.org> --- drivers/base/platform.c | 60 +++++++++++++++++++++++++++------ include/linux/platform_device.h | 2 ++ 2 files changed, 52 insertions(+), 10 deletions(-)
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index 09450349cf323..fad33d6b2349a 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c@@ -150,25 +150,37 @@ devm_platform_ioremap_resource_byname(struct platform_device *pdev, EXPORT_SYMBOL_GPL(devm_platform_ioremap_resource_byname); #endif /* CONFIG_HAS_IOMEM */ +static const struct cpumask *get_irq_affinity(struct platform_device *dev, + unsigned int num) +{ + const struct cpumask *mask = NULL; +#ifndef CONFIG_SPARC + struct fwnode_handle *fwnode = dev_fwnode(&dev->dev); + + if (is_of_node(fwnode)) + mask = of_irq_get_affinity(to_of_node(fwnode), num); + else if (is_acpi_device_node(fwnode)) + mask = acpi_irq_get_affinity(ACPI_HANDLE_FWNODE(fwnode), num); +#endif + + return mask ?: cpu_possible_mask; +} + /** - * platform_get_irq_optional - get an optional IRQ for a device + * platform_get_irq_affinity - get an optional IRQ and its affnity for a device * @dev: platform device * @num: IRQ number index + * @affinity: optional cpumask pointer to get the affinity of a per-cpu IRQ * * Gets an IRQ for a platform device. Device drivers should check the return * value for errors so as to not pass a negative integer value to the - * request_irq() APIs. This is the same as platform_get_irq(), except that it - * does not print an error message if an IRQ can not be obtained. - * - * For example:: - * - * int irq = platform_get_irq_optional(pdev, 0); - * if (irq < 0) - * return irq; + * request_irq() APIs. Optional affinity information is provided in the + * affinity pointer if available, and NULL otherwise. * * Return: non-zero IRQ number on success, negative error number on failure. */ -int platform_get_irq_optional(struct platform_device *dev, unsigned int num) +int platform_get_irq_affinity(struct platform_device *dev, unsigned int num, + const struct cpumask **affinity) { int ret; #ifdef CONFIG_SPARC
@@ -236,8 +248,36 @@ int platform_get_irq_optional(struct platform_device *dev, unsigned int num) out: if (WARN(!ret, "0 is an invalid IRQ number\n")) return -EINVAL; + + if (ret > 0 && affinity) + *affinity = get_irq_affinity(dev, num); + return ret; } +EXPORT_SYMBOL_GPL(platform_get_irq_affinity); + +/** + * platform_get_irq_optional - get an optional IRQ for a device + * @dev: platform device + * @num: IRQ number index + * + * Gets an IRQ for a platform device. Device drivers should check the return + * value for errors so as to not pass a negative integer value to the + * request_irq() APIs. This is the same as platform_get_irq(), except that it + * does not print an error message if an IRQ can not be obtained. + * + * For example:: + * + * int irq = platform_get_irq_optional(pdev, 0); + * if (irq < 0) + * return irq; + * + * Return: non-zero IRQ number on success, negative error number on failure. + */ +int platform_get_irq_optional(struct platform_device *dev, unsigned int num) +{ + return platform_get_irq_affinity(dev, num, NULL); +} EXPORT_SYMBOL_GPL(platform_get_irq_optional); /**
diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h
index 074754c23d330..ad66333ce85ce 100644
--- a/include/linux/platform_device.h
+++ b/include/linux/platform_device.h@@ -102,6 +102,8 @@ devm_platform_ioremap_resource_byname(struct platform_device *pdev, extern int platform_get_irq(struct platform_device *, unsigned int); extern int platform_get_irq_optional(struct platform_device *, unsigned int); +extern int platform_get_irq_affinity(struct platform_device *, unsigned int, + const struct cpumask **); extern int platform_irq_count(struct platform_device *); extern int devm_platform_get_irqs_affinity(struct platform_device *dev, struct irq_affinity *affd,
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2.39.2