4 files changed, 38 insertions, 0 deletions

diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index 5113c080f0c4..65c9b58655ff 100644
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -1924,6 +1924,12 @@ static phys_addr_t amd_iommu_iova_to_phys(struct iommu_domain *dom,
         return paddr;
 }
 
+static int amd_iommu_domain_has_cap(struct iommu_domain *domain,
+                                    unsigned long cap)
+{
+        return 0;
+}
+
 static struct iommu_ops amd_iommu_ops = {
         .domain_init = amd_iommu_domain_init,
         .domain_destroy = amd_iommu_domain_destroy,
@@ -1932,5 +1938,6 @@ static struct iommu_ops amd_iommu_ops = {
         .map = amd_iommu_map_range,
         .unmap = amd_iommu_unmap_range,
         .iova_to_phys = amd_iommu_iova_to_phys,
+        .domain_has_cap = amd_iommu_domain_has_cap,
 };
 
diff --git a/drivers/base/iommu.c b/drivers/base/iommu.c
index 5e039d4f877c..c314f144825f 100644
--- a/drivers/base/iommu.c
+++ b/drivers/base/iommu.c
@@ -98,3 +98,10 @@ phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain,
         return iommu_ops->iova_to_phys(domain, iova);
 }
 EXPORT_SYMBOL_GPL(iommu_iova_to_phys);
+
+int iommu_domain_has_cap(struct iommu_domain *domain,
+                         unsigned long cap)
+{
+        return iommu_ops->domain_has_cap(domain, cap);
+}
+EXPORT_SYMBOL_GPL(iommu_domain_has_cap);
diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index be999ff025af..3778ab149baf 100644
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -3158,6 +3158,17 @@ static phys_addr_t intel_iommu_iova_to_phys(struct iommu_domain *domain,
         return phys;
 }
 
+static int intel_iommu_domain_has_cap(struct iommu_domain *domain,
+                                      unsigned long cap)
+{
+        struct dmar_domain *dmar_domain = domain->priv;
+
+        if (cap == IOMMU_CAP_CACHE_COHERENCY)
+                return dmar_domain->iommu_snooping;
+
+        return 0;
+}
+
 static struct iommu_ops intel_iommu_ops = {
         .domain_init    = intel_iommu_domain_init,
         .domain_destroy = intel_iommu_domain_destroy,
@@ -3166,6 +3177,7 @@ static struct iommu_ops intel_iommu_ops = {
         .map            = intel_iommu_map_range,
         .unmap          = intel_iommu_unmap_range,
         .iova_to_phys   = intel_iommu_iova_to_phys,
+        .domain_has_cap = intel_iommu_domain_has_cap,
 };
 
 static void __devinit quirk_iommu_rwbf(struct pci_dev *dev)
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 8a7bfb1b6ca0..0cf3a4e43f23 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -28,6 +28,8 @@ struct iommu_domain {
         void *priv;
 };
 
+#define IOMMU_CAP_CACHE_COHERENCY       0x1
+
 struct iommu_ops {
         int (*domain_init)(struct iommu_domain *domain);
         void (*domain_destroy)(struct iommu_domain *domain);
@@ -39,6 +41,8 @@ struct iommu_ops {
                       size_t size);
         phys_addr_t (*iova_to_phys)(struct iommu_domain *domain,
                                     unsigned long iova);
+        int (*domain_has_cap)(struct iommu_domain *domain,
+                              unsigned long cap);
 };
 
 #ifdef CONFIG_IOMMU_API
@@ -57,6 +61,8 @@ extern void iommu_unmap_range(struct iommu_domain *domain, unsigned long iova,
                               size_t size);
 extern phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain,
                                       unsigned long iova);
+extern int iommu_domain_has_cap(struct iommu_domain *domain,
+                                unsigned long cap);
 
 #else /* CONFIG_IOMMU_API */
 
@@ -107,6 +113,12 @@ static inline phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain,
         return 0;
 }
 
+static inline int domain_has_cap(struct iommu_domain *domain,
+                                 unsigned long cap)
+{
+        return 0;
+}
+
 #endif /* CONFIG_IOMMU_API */
 
 #endif /* __LINUX_IOMMU_H */