Hi Robin,
On 01/17/2018 08:31 PM, Robin Murphy wrote:
On 16/01/18 13:25, Jeffy Chen wrote:
IOMMU drivers are supposed to call this function instead of manually
creating a group in their .add_device callback. This behavior is not
strictly required by ARM DMA mapping implementation, but ARM64 already
relies on it. This patch fixes the rockchip-iommu driver to comply with
this requirement.
FWIW that's not 100% true: what arm64 relies on is the group having a
default DMA ops domain. Technically, you *could* open-code that in the
driver's group allocation, but obviously using the appropriate existing
API is nicer :)
ok, will rewrite the commit message.
[...]
@@ -1182,6 +1164,29 @@ static void rk_iommu_remove_device(struct
device *dev)
iommu_group_remove_device(dev);
}
+static struct iommu_group *rk_iommu_device_group(struct device *dev)
+{
+ struct iommu_group *group;
+ int ret;
+
+ group = iommu_group_get(dev);
+ if (!group) {
This check is pointless - if dev->iommu_group were non-NULL you wouldn't
have been called in the first place.
right, it's allocated in the probe.
Robin.
