diff mbox series

[XEN,v12,10/20] xen/iommu: protect iommu_add_dt_device() with dtdevs_lock

Message ID 20230906011631.30310-11-vikram.garhwal@amd.com (mailing list archive)
State New, archived
Headers show
Series dynamic node programming using overlay dtbo | expand

Commit Message

Vikram Garhwal Sept. 6, 2023, 1:16 a.m. UTC 
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 accessed by dynamic node add/remove using
device tree overlays.

Signed-off-by: Vikram Garhwal <vikram.garhwal@amd.com>
Reviewed-by: Luca Fancellu <luca.fancellu@arm.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>

---
    Changes from v7:
        Update commit message and fix indent.
---
---
 xen/drivers/passthrough/device_tree.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/xen/drivers/passthrough/device_tree.c b/xen/drivers/passthrough/device_tree.c
index a7d86a20a0..687c61e7da 100644
--- a/xen/drivers/passthrough/device_tree.c
+++ b/xen/drivers/passthrough/device_tree.c
@@ -147,6 +147,8 @@  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.
@@ -159,7 +161,10 @@  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;
@@ -190,6 +195,8 @@  int iommu_add_dt_device(struct dt_device_node *np)
     if ( rc < 0 )
         iommu_fwspec_free(dev);
 
+ fail:
+    spin_unlock(&dtdevs_lock);
     return rc;
 }