AMD IOMMU: add domain id free function

Impact: add code to release a domain id

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index 8a0fd3d09973..0922d5fe633c 100644
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -571,6 +571,18 @@ static u16 domain_id_alloc(void)
         return id;
 }
 
+#ifdef CONFIG_IOMMU_API
+static void domain_id_free(int id)
+{
+        unsigned long flags;
+
+        write_lock_irqsave(&amd_iommu_devtable_lock, flags);
+        if (id > 0 && id < MAX_DOMAIN_ID)
+                __clear_bit(id, amd_iommu_pd_alloc_bitmap);
+        write_unlock_irqrestore(&amd_iommu_devtable_lock, flags);
+}
+#endif
+
 /*
  * Used to reserve address ranges in the aperture (e.g. for exclusion
  * ranges.