diff mbox series

[XEN,v11,10/20] xen/iommu: protect iommu_add_dt_device() with dtdevs_lock

Message ID 20230901045947.32351-11-vikram.garhwal@amd.com (mailing list archive)
State Superseded
Headers show
Series dynamic node programming using overlay dtbo | expand

Commit Message

Vikram Garhwal Sept. 1, 2023, 4:59 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>

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

Comments

Stefano Stabellini Sept. 6, 2023, 12:29 a.m. UTC | #1 
On Thu, 31 Aug 2023, Vikram Garhwal wrote:
> 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 --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;
>  }
>  
> -- 
> 2.17.1
>
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;
 }