[RFC PATCH] iommu: create direct_mapping after device attached
From: honghui.zhang at mediatek.com <hidden>
Date: 2016-07-20 12:49:43
Also in:
linux-devicetree, linux-iommu, linux-mediatek, lkml
Subsystem:
iommu subsystem, the rest · Maintainers:
Joerg Roedel, Will Deacon, Linus Torvalds
From: Honghui Zhang <redacted> For mtk iommu, the domain_finalize was called in device attatch, the mtk iommu iopgt ops was allocated and initialized in domain_finalize, the iommu_group_create_direct_mappings would call the map interface to implement the map. If it's earlier than device attach, there would be NULL dereference. Move the iommu_group_create_direct_mappings call after device attached. Signed-off-by: Honghui Zhang <redacted> --- drivers/iommu/iommu.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 3000051..24c671c 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c@@ -427,14 +427,19 @@ rename: dev->iommu_group = group; - iommu_group_create_direct_mappings(group, dev); - mutex_lock(&group->mutex); list_add_tail(&device->list, &group->devices); if (group->domain) __iommu_attach_device(group->domain, dev); mutex_unlock(&group->mutex); + /* + * For some iommu driver like mtk iommu, the map callback was assigned + * after device attached. The direct_mappings would call iommu map and + * dereference NULL if it's called earlier than attach_device. + */ + iommu_group_create_direct_mappings(group, dev); + /* Notify any listeners about change to group. */ blocking_notifier_call_chain(&group->notifier, IOMMU_GROUP_NOTIFY_ADD_DEVICE, dev);
--
1.8.1.1.dirty