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authorJohn Garry <john.garry@huawei.com>2020-12-02 18:36:56 +0800
committerMarc Zyngier <maz@kernel.org>2020-12-11 14:47:51 +0000
commite15f2fa959f2cce8a05e8e3a596e75d068cd42c5 (patch)
tree6d5ae39c5e3cbd1d206e288d5d328e9392c5aa4c /drivers/base/platform.c
parent1c3f69b4543af0aad514c127298e5ea40392575d (diff)
downloadlwn-e15f2fa959f2cce8a05e8e3a596e75d068cd42c5.tar.gz
lwn-e15f2fa959f2cce8a05e8e3a596e75d068cd42c5.zip
driver core: platform: Add devm_platform_get_irqs_affinity()
Drivers for multi-queue platform devices may also want managed interrupts for handling HW queue completion interrupts, so add support. The function accepts an affinity descriptor pointer, which covers all IRQs expected for the device. The function is devm class as the only current in-tree user will also use devm method for requesting the interrupts; as such, the function is made as devm as it can ensure ordering of freeing the irq and disposing of the mapping. Signed-off-by: John Garry <john.garry@huawei.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Acked-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/1606905417-183214-5-git-send-email-john.garry@huawei.com
Diffstat (limited to 'drivers/base/platform.c')
-rw-r--r--drivers/base/platform.c121
1 files changed, 121 insertions, 0 deletions
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index 88aef93eb4dd..ea8add164b89 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -15,6 +15,8 @@
#include <linux/of_irq.h>
#include <linux/module.h>
#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
#include <linux/dma-mapping.h>
#include <linux/memblock.h>
#include <linux/err.h>
@@ -289,6 +291,125 @@ int platform_irq_count(struct platform_device *dev)
}
EXPORT_SYMBOL_GPL(platform_irq_count);
+struct irq_affinity_devres {
+ unsigned int count;
+ unsigned int irq[];
+};
+
+static void platform_disable_acpi_irq(struct platform_device *pdev, int index)
+{
+ struct resource *r;
+
+ r = platform_get_resource(pdev, IORESOURCE_IRQ, index);
+ if (r)
+ irqresource_disabled(r, 0);
+}
+
+static void devm_platform_get_irqs_affinity_release(struct device *dev,
+ void *res)
+{
+ struct irq_affinity_devres *ptr = res;
+ int i;
+
+ for (i = 0; i < ptr->count; i++) {
+ irq_dispose_mapping(ptr->irq[i]);
+
+ if (has_acpi_companion(dev))
+ platform_disable_acpi_irq(to_platform_device(dev), i);
+ }
+}
+
+/**
+ * devm_platform_get_irqs_affinity - devm method to get a set of IRQs for a
+ * device using an interrupt affinity descriptor
+ * @dev: platform device pointer
+ * @affd: affinity descriptor
+ * @minvec: minimum count of interrupt vectors
+ * @maxvec: maximum count of interrupt vectors
+ * @irqs: pointer holder for IRQ numbers
+ *
+ * Gets a set of IRQs for a platform device, and updates IRQ afffinty according
+ * to the passed affinity descriptor
+ *
+ * Return: Number of vectors on success, negative error number on failure.
+ */
+int devm_platform_get_irqs_affinity(struct platform_device *dev,
+ struct irq_affinity *affd,
+ unsigned int minvec,
+ unsigned int maxvec,
+ int **irqs)
+{
+ struct irq_affinity_devres *ptr;
+ struct irq_affinity_desc *desc;
+ size_t size;
+ int i, ret, nvec;
+
+ if (!affd)
+ return -EPERM;
+
+ if (maxvec < minvec)
+ return -ERANGE;
+
+ nvec = platform_irq_count(dev);
+
+ if (nvec < minvec)
+ return -ENOSPC;
+
+ nvec = irq_calc_affinity_vectors(minvec, nvec, affd);
+ if (nvec < minvec)
+ return -ENOSPC;
+
+ if (nvec > maxvec)
+ nvec = maxvec;
+
+ size = sizeof(*ptr) + sizeof(unsigned int) * nvec;
+ ptr = devres_alloc(devm_platform_get_irqs_affinity_release, size,
+ GFP_KERNEL);
+ if (!ptr)
+ return -ENOMEM;
+
+ ptr->count = nvec;
+
+ for (i = 0; i < nvec; i++) {
+ int irq = platform_get_irq(dev, i);
+ if (irq < 0) {
+ ret = irq;
+ goto err_free_devres;
+ }
+ ptr->irq[i] = irq;
+ }
+
+ desc = irq_create_affinity_masks(nvec, affd);
+ if (!desc) {
+ ret = -ENOMEM;
+ 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;
+}
+EXPORT_SYMBOL_GPL(devm_platform_get_irqs_affinity);
+
/**
* platform_get_resource_byname - get a resource for a device by name
* @dev: platform device