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/include/linux/iommu.h b/include/linux/iommu.h
index 8a7bfb1..0cf3a4e 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -28,6 +28,8 @@
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 @@
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 @@
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 @@
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 */