iommu: Add domain_has_cap iommu_ops

This iommu_op can tell if domain have a specific capability, like snooping
control for Intel IOMMU, which can be used by other components of kernel to
adjust the behaviour.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index 5113c08..65c9b58 100644 (file)
--- 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 5e039d4..c314f14 100644 (file)
--- 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 be999ff..3778ab1 100644 (file)
--- 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 8a7bfb1..0cf3a4e 100644 (file)
--- 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 */