x86/amd-iommu: Add per IOMMU reference counting

This patch adds reference counting for protection domains
per IOMMU. This allows a smarter TLB flushing strategy.

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

1 files changed, 9 insertions, 3 deletions

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);