2 files changed, 17 insertions, 0 deletions

diff --git a/drivers/pci/intr_remapping.c b/drivers/pci/intr_remapping.c
index c26633d7e7da..ef25caade54b 100644
--- a/drivers/pci/intr_remapping.c
+++ b/drivers/pci/intr_remapping.c
@@ -415,12 +415,27 @@ static void iommu_set_intr_remapping(struct intel_iommu *iommu, int mode)
 
         /* Set interrupt-remapping table pointer */
         cmd = iommu->gcmd | DMA_GCMD_SIRTP;
+        iommu->gcmd |= DMA_GCMD_SIRTP;
         writel(cmd, iommu->reg + DMAR_GCMD_REG);
 
         IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
                       readl, (sts & DMA_GSTS_IRTPS), sts);
         spin_unlock_irqrestore(&iommu->register_lock, flags);
 
+        if (mode == 0) {
+                spin_lock_irqsave(&iommu->register_lock, flags);
+
+                /* enable comaptiblity format interrupt pass through */
+                cmd = iommu->gcmd | DMA_GCMD_CFI;
+                iommu->gcmd |= DMA_GCMD_CFI;
+                writel(cmd, iommu->reg + DMAR_GCMD_REG);
+
+                IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
+                              readl, (sts & DMA_GSTS_CFIS), sts);
+
+                spin_unlock_irqrestore(&iommu->register_lock, flags);
+        }
+
         /*
          * global invalidation of interrupt entry cache before enabling
          * interrupt-remapping.
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index 3771cd1f876e..aa8c53171233 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -164,6 +164,7 @@ static inline void dmar_writeq(void __iomem *addr, u64 val)
 #define DMA_GCMD_QIE (((u32)1) << 26)
 #define DMA_GCMD_SIRTP (((u32)1) << 24)
 #define DMA_GCMD_IRE (((u32) 1) << 25)
+#define DMA_GCMD_CFI (((u32) 1) << 23)
 
 /* GSTS_REG */
 #define DMA_GSTS_TES (((u32)1) << 31)
@@ -174,6 +175,7 @@ static inline void dmar_writeq(void __iomem *addr, u64 val)
 #define DMA_GSTS_QIES (((u32)1) << 26)
 #define DMA_GSTS_IRTPS (((u32)1) << 24)
 #define DMA_GSTS_IRES (((u32)1) << 25)
+#define DMA_GSTS_CFIS (((u32)1) << 23)
 
 /* CCMD_REG */
 #define DMA_CCMD_ICC (((u64)1) << 63)