Protect iommu_add_dt_device() with dtdevs_lock to prevent concurrent access
to add/remove/assign/deassign.
With addition of dynamic programming feature(follow-up patches in this series),
this function can be concurrently access by pci device assign/deassign and also
by dynamic node add/remove using device tree overlays.
Signed-off-by: Vikram Garhwal <vikram.garh...@amd.com>
Reviewed-by: Luca Fancellu <luca.fance...@arm.com>
Reviewed-by: Michal Orzel <michal.or...@amd.com>
---
Changes from v7:
Update commit message and fix indent.
---
---
xen/drivers/passthrough/device_tree.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/xen/drivers/passthrough/device_tree.c
b/xen/drivers/passthrough/device_tree.c
index 5796ee1f93..096ef2dd68 100644
--- a/xen/drivers/passthrough/device_tree.c
+++ b/xen/drivers/passthrough/device_tree.c
@@ -148,6 +148,8 @@ int iommu_add_dt_device(struct dt_device_node *np)
if ( dev_iommu_fwspec_get(dev) )
return 0;
+ spin_lock(&dtdevs_lock);
+
/*
* According to the Documentation/devicetree/bindings/iommu/iommu.txt
* from Linux.
@@ -160,7 +162,10 @@ int iommu_add_dt_device(struct dt_device_node *np)
* these callback implemented.
*/
if ( !ops->add_device || !ops->dt_xlate )
- return -EINVAL;
+ {
+ rc = -EINVAL;
+ goto fail;
+ }
if ( !dt_device_is_available(iommu_spec.np) )
break;
@@ -191,6 +196,8 @@ int iommu_add_dt_device(struct dt_device_node *np)
if ( rc < 0 )
iommu_fwspec_free(dev);
+ fail:
+ spin_unlock(&dtdevs_lock);
return rc;
}
--
2.17.1
