2 files changed, 11 insertions, 3 deletions

diff --git a/arch/x86/include/asm/amd_iommu_types.h b/arch/x86/include/asm/amd_iommu_types.h
index ab3e7bf1af71..e68b14811380 100644
--- a/arch/x86/include/asm/amd_iommu_types.h
+++ b/arch/x86/include/asm/amd_iommu_types.h
@@ -238,7 +238,9 @@ struct protection_domain {
         unsigned long flags;    /* flags to find out type of domain */
         bool updated;           /* complete domain flush required */
         unsigned dev_cnt;       /* devices assigned to this domain */
+        unsigned dev_iommu[MAX_IOMMUS]; /* per-IOMMU reference count */
         void *priv;             /* private data */
+
 };
 
 /*
diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index 7fe28be3b548..8c38f0085403 100644
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -1175,7 +1175,9 @@ static void __attach_device(struct amd_iommu *iommu,
         /* update DTE entry */
         set_dte_entry(devid, domain);
 
-        domain->dev_cnt += 1;
+        /* Do reference counting */
+        domain->dev_iommu[iommu->index] += 1;
+        domain->dev_cnt                 += 1;
 
         /* ready */
         spin_unlock(&domain->lock);
@@ -1209,6 +1211,9 @@ static void attach_device(struct amd_iommu *iommu,
  */
 static void __detach_device(struct protection_domain *domain, u16 devid)
 {
+        struct amd_iommu *iommu = amd_iommu_rlookup_table[devid];
+
+        BUG_ON(!iommu);
 
         /* lock domain */
         spin_lock(&domain->lock);
@@ -1223,8 +1228,9 @@ static void __detach_device(struct protection_domain *domain, u16 devid)
 
         amd_iommu_apply_erratum_63(devid);
 
-        /* decrease reference counter */
-        domain->dev_cnt -= 1;
+        /* decrease reference counters */
+        domain->dev_iommu[iommu->index] -= 1;
+        domain->dev_cnt                 -= 1;
 
         /* ready */
         spin_unlock(&domain->lock);