[PATCH v3 08/14] iommufd/viommu: Add iommufd_viommu_report_irq helper

[Nicolin Chen <nicolinc@nvidia.com>]

Similar to iommu_report_device_fault, this allows IOMMU drivers to report,
from threaded IRQ handlers to user space hypervisors, IRQs or events that
belong to a vIOMMU.

Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
---
 include/linux/iommufd.h        |  9 +++++++++
 drivers/iommu/iommufd/driver.c | 37 ++++++++++++++++++++++++++++++++++
 2 files changed, 46 insertions(+)

diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h
index ac1f1897d290..c5909125775a 100644
--- a/include/linux/iommufd.h
+++ b/include/linux/iommufd.h
@@ -192,6 +192,8 @@ struct device *iommufd_viommu_find_dev(struct iommufd_viommu *viommu,
 				       unsigned long vdev_id);
 unsigned long iommufd_viommu_get_vdev_id(struct iommufd_viommu *viommu,
 					 struct device *dev);
+int iommufd_viommu_report_irq(struct iommufd_viommu *viommu, unsigned int type,
+			      void *irq_ptr, size_t irq_len);
 #else /* !CONFIG_IOMMUFD_DRIVER_CORE */
 static inline struct iommufd_object *
 _iommufd_object_alloc(struct iommufd_ctx *ictx, size_t size,
@@ -211,6 +213,13 @@ iommufd_viommu_get_vdev_id(struct iommufd_viommu *viommu, struct device *dev)
 {
 	return 0;
 }
+
+static inline int iommufd_viommu_report_irq(struct iommufd_viommu *viommu,
+					    unsigned int type, void *irq_ptr,
+					    size_t irq_len)
+{
+	return -EOPNOTSUPP;
+}
 #endif /* CONFIG_IOMMUFD_DRIVER_CORE */
 
 /*
diff --git a/drivers/iommu/iommufd/driver.c b/drivers/iommu/iommufd/driver.c
index e5d7397c0a6c..2ab793f27f72 100644
--- a/drivers/iommu/iommufd/driver.c
+++ b/drivers/iommu/iommufd/driver.c
@@ -69,5 +69,42 @@ unsigned long iommufd_viommu_get_vdev_id(struct iommufd_viommu *viommu,
 }
 EXPORT_SYMBOL_NS_GPL(iommufd_viommu_get_vdev_id, "IOMMUFD");
 
+/* Typically called in driver's threaded IRQ handler */
+int iommufd_viommu_report_irq(struct iommufd_viommu *viommu, unsigned int type,
+			      void *irq_ptr, size_t irq_len)
+{
+	struct iommufd_virq_header *header;
+	struct iommufd_virq *virq;
+	int rc = 0;
+
+	if (!viommu)
+		return -ENODEV;
+	if (WARN_ON_ONCE(!irq_len || !irq_ptr))
+		return -EINVAL;
+
+	down_read(&viommu->virqs_rwsem);
+
+	virq = iommufd_viommu_find_virq(viommu, type);
+	if (!virq) {
+		rc = -EOPNOTSUPP;
+		goto out_unlock_virqs;
+	}
+
+	header = kzalloc(sizeof(*header) + irq_len, GFP_KERNEL);
+	if (!header) {
+		rc = -ENOMEM;
+		goto out_unlock_virqs;
+	}
+	header->irq_data = (void *)header + sizeof(*header);
+	memcpy(header->irq_data, irq_ptr, irq_len);
+	header->irq_len = irq_len;
+
+	iommufd_virq_handler(virq, header);
+out_unlock_virqs:
+	up_read(&viommu->virqs_rwsem);
+	return rc;
+}
+EXPORT_SYMBOL_NS_GPL(iommufd_viommu_report_irq, "IOMMUFD");
+
 MODULE_DESCRIPTION("iommufd code shared with builtin modules");
 MODULE_LICENSE("GPL");
-- 
2.43.0