summaryrefslogtreecommitdiffstats
path: root/drivers/iommu/iommu.c
diff options
context:
space:
mode:
authorRobin Murphy <robin.murphy@arm.com>2022-04-25 13:42:02 +0100
committerJoerg Roedel <jroedel@suse.de>2022-04-28 10:30:25 +0200
commited36d04e8f8d7b00db451b0fa56a54e8e02ec43e (patch)
treefbf6b85e5f30de228ecf43abeea69ce86881b8e5 /drivers/iommu/iommu.c
parentf316ba0a8814f4c91e80a435da3421baf0ddd24c (diff)
downloadlinux-ed36d04e8f8d7b00db451b0fa56a54e8e02ec43e.tar.bz2
iommu: Introduce device_iommu_capable()
iommu_capable() only really works for systems where all IOMMU instances are completely homogeneous, and all devices are IOMMU-mapped. Implement the new variant which will be able to give a more accurate answer for whichever device the caller is actually interested in, and even more so once all the external users have been converted and we can reliably pass the device pointer through the internal driver interface too. Signed-off-by: Robin Murphy <robin.murphy@arm.com> Link: https://lore.kernel.org/r/8407eb9586677995b7a9fd70d0fd82d85929a9bb.1650878781.git.robin.murphy@arm.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu/iommu.c')
-rw-r--r--drivers/iommu/iommu.c23
1 files changed, 23 insertions, 0 deletions
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index f2c45b85b9fc..780c11734979 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1906,6 +1906,29 @@ bool iommu_present(struct bus_type *bus)
}
EXPORT_SYMBOL_GPL(iommu_present);
+/**
+ * device_iommu_capable() - check for a general IOMMU capability
+ * @dev: device to which the capability would be relevant, if available
+ * @cap: IOMMU capability
+ *
+ * Return: true if an IOMMU is present and supports the given capability
+ * for the given device, otherwise false.
+ */
+bool device_iommu_capable(struct device *dev, enum iommu_cap cap)
+{
+ const struct iommu_ops *ops;
+
+ if (!dev->iommu || !dev->iommu->iommu_dev)
+ return false;
+
+ ops = dev_iommu_ops(dev);
+ if (!ops->capable)
+ return false;
+
+ return ops->capable(cap);
+}
+EXPORT_SYMBOL_GPL(device_iommu_capable);
+
bool iommu_capable(struct bus_type *bus, enum iommu_cap cap)
{
if (!bus->iommu_ops || !bus->iommu_ops->capable)