[PATCH 7/9] iommu: Add helper to set iopf handler for domain

[Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>]

To avoid open code everywhere.

Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
---
 include/linux/iommu.h | 14 +++++++++++---
 drivers/iommu/iommu.c | 20 ++++++++++++++++++--
 2 files changed, 29 insertions(+), 5 deletions(-)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index f10be6680f8a..c86ff10b40f3 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -198,6 +198,8 @@ struct iommu_page_response {
 
 typedef int (*iommu_fault_handler_t)(struct iommu_domain *,
 			struct device *, unsigned long, int, void *);
+typedef enum iommu_page_response_code (*iommu_iopf_handler_t)(struct iommu_fault *,
+			struct device *dev, void *data);
 
 struct iommu_domain_geometry {
 	dma_addr_t aperture_start; /* First address that can be mapped    */
@@ -247,9 +249,7 @@ struct iommu_domain {
 	unsigned long pgsize_bitmap;	/* Bitmap of page sizes in use */
 	struct iommu_domain_geometry geometry;
 	struct iommu_dma_cookie *iova_cookie;
-	enum iommu_page_response_code (*iopf_handler)(struct iommu_fault *fault,
-						      struct device *dev,
-						      void *data);
+	iommu_iopf_handler_t iopf_handler;
 	void *fault_data;
 	union {
 		struct {
@@ -634,6 +634,8 @@ extern ssize_t iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
 extern phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain, dma_addr_t iova);
 extern void iommu_set_fault_handler(struct iommu_domain *domain,
 			iommu_fault_handler_t handler, void *token);
+void iommu_domain_set_iopf_handler(struct iommu_domain *domain,
+				   iommu_iopf_handler_t handler, void *data);
 
 extern void iommu_get_resv_regions(struct device *dev, struct list_head *list);
 extern void iommu_put_resv_regions(struct device *dev, struct list_head *list);
@@ -957,6 +959,12 @@ static inline void iommu_set_fault_handler(struct iommu_domain *domain,
 {
 }
 
+static inline void iommu_domain_set_iopf_handler(struct iommu_domain *domain,
+						 iommu_iopf_handler_t handler,
+						 void *data)
+{
+}
+
 static inline void iommu_get_resv_regions(struct device *dev,
 					struct list_head *list)
 {
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index fc5e9698b35c..3dc59af24208 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1847,6 +1847,23 @@ void iommu_set_fault_handler(struct iommu_domain *domain,
 }
 EXPORT_SYMBOL_GPL(iommu_set_fault_handler);
 
+/**
+ * iommu_domain_set_iopf_handler() - set io page fault handler for a domain
+ * @domain: iommu domain
+ * @handler: fault handler
+ * @data: user data, will be passed back to the fault handler
+ *
+ * This function should be used by iommu domain users which want to be notified
+ * whenever an IOMMU I/O page fault happens.
+ */
+void iommu_domain_set_iopf_handler(struct iommu_domain *domain,
+				   iommu_iopf_handler_t handler, void *data)
+{
+	domain->iopf_handler = handler;
+	domain->fault_data = data;
+}
+EXPORT_SYMBOL_GPL(iommu_domain_set_iopf_handler);
+
 static struct iommu_domain *__iommu_domain_alloc(const struct bus_type *bus,
 						 unsigned type)
 {
@@ -3335,8 +3352,7 @@ struct iommu_domain *iommu_sva_domain_alloc(struct device *dev,
 	domain->type = IOMMU_DOMAIN_SVA;
 	mmgrab(mm);
 	domain->mm = mm;
-	domain->iopf_handler = iommu_sva_handle_iopf;
-	domain->fault_data = mm;
+	iommu_domain_set_iopf_handler(domain, iommu_sva_handle_iopf, mm);
 
 	return domain;
 }
-- 
2.34.1