AMD IOMMU: add device reference counting for protection domains

Impact: know how many devices are assigned to a domain

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

1 files changed, 2 insertions, 1 deletions

diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index 5c465c91150e..8b45bc49d1c5 100644
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -825,9 +825,10 @@ static void set_device_domain(struct amd_iommu *iommu,
                               u16 devid)
 {
         unsigned long flags;
-
         u64 pte_root = virt_to_phys(domain->pt_root);
 
+        domain->dev_cnt += 1;
+
         pte_root |= (domain->mode & DEV_ENTRY_MODE_MASK)
                     << DEV_ENTRY_MODE_SHIFT;
         pte_root |= IOMMU_PTE_IR | IOMMU_PTE_IW | IOMMU_PTE_P | IOMMU_PTE_TV;