[PATCH v8 05/11] ACPI/IORT: Add a helper to retrieve RMR memory regions

[Shameer Kolothum <shameerali.kolothum.thodi@xxxxxxxxxx>]

Add helper functions (iort_iommu_get/put_rmrs()) that
retrieves/releases RMR memory descriptors associated
with a given IOMMU. This will be used by IOMMU drivers
to set up necessary mappings.

Invoke it from the generic iommu helper functions.

Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@xxxxxxxxxx>
---
 drivers/acpi/arm64/iort.c | 56 +++++++++++++++++++++++++++++++++++++++
 drivers/iommu/dma-iommu.c |  4 +++
 include/linux/acpi_iort.h | 14 ++++++++++
 3 files changed, 74 insertions(+)

diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index 05da9ebff50a..b2c959c72fb2 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -1055,6 +1055,57 @@ static void iort_find_rmrs(struct acpi_iort_node *iommu, struct device *dev,
 	}
 }
 
+/**
+ * iort_iommu_dma_put_rmrs - Free any memory associated with RMRs.
+ * @iommu_fwnode: fwnode associated with IOMMU
+ * @head: Resereved region list
+ *
+ * This function go through the provided reserved region list and
+ * free up memory associated with RMR entries and delete them from
+ * the list.
+ */
+void iort_iommu_put_rmrs(struct fwnode_handle *iommu_fwnode,
+			 struct list_head *head)
+{
+	struct iommu_resv_region *e, *tmp;
+
+	/*
+	 * RMR entries will have mem allocated for fw_data.rmr.sids.
+	 * Free the mem and delete the node.
+	 */
+	list_for_each_entry_safe(e, tmp, head, list) {
+		if (e->fw_data.rmr.sids) {
+			kfree(e->fw_data.rmr.sids);
+			list_del(&e->list);
+			kfree(e);
+		}
+	}
+}
+
+/**
+ *
+ * iort_iommu_dma_get_rmrs - Retrieve Reserved Memory Regions(RMRs) associated
+ *                      with a given IOMMU and dev.
+ * @iommu_fwnode: fwnode associated with IOMMU
+ * @dev: Device associated with RMR(Optional)
+ * @list: RMR list to be populated
+ *
+ * This function populates the RMR list associated with a given IOMMU and
+ * dev(if provided). If dev is NULL, the function populates all the RMRs
+ * associated with the given IOMMU.
+ */
+void iort_iommu_get_rmrs(struct fwnode_handle *iommu_fwnode, struct device *dev,
+			 struct list_head *head)
+{
+	struct acpi_iort_node *iommu;
+
+	iommu = iort_get_iort_node(iommu_fwnode);
+	if (!iommu)
+		return;
+
+	iort_find_rmrs(iommu, dev, head);
+}
+
 /**
  * iort_iommu_msi_get_resv_regions - Reserved region driver helper
  * @dev: Device from iommu_get_resv_regions()
@@ -1287,6 +1338,11 @@ int iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head *head)
 { return 0; }
 int iort_iommu_configure_id(struct device *dev, const u32 *input_id)
 { return -ENODEV; }
+void iort_iommu_get_rmrs(struct fwnode_handle *fwnode, struct device *dev,
+			 struct list_head *head)
+{ }
+void iort_iommu_put_rmrs(struct fwnode_handle *fwnode, struct list_head *head)
+{ }
 #endif
 
 static int nc_dma_get_range(struct device *dev, u64 *size)
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 65ab01d5128b..b33e4df85de1 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -382,12 +382,16 @@ void iommu_put_dma_cookie(struct iommu_domain *domain)
 void iommu_dma_get_rmrs(struct fwnode_handle *iommu_fwnode, struct device *dev,
 			struct list_head *list)
 {
+	if (!is_of_node(iommu_fwnode))
+		iort_iommu_get_rmrs(iommu_fwnode, dev, list);
 }
 EXPORT_SYMBOL(iommu_dma_get_rmrs);
 
 void iommu_dma_put_rmrs(struct fwnode_handle *iommu_fwnode,
 			struct list_head *list)
 {
+	if (!is_of_node(iommu_fwnode))
+		iort_iommu_put_rmrs(iommu_fwnode, list);
 }
 EXPORT_SYMBOL(iommu_dma_put_rmrs);
 
diff --git a/include/linux/acpi_iort.h b/include/linux/acpi_iort.h
index f1f0842a2cb2..212f7f178ec3 100644
--- a/include/linux/acpi_iort.h
+++ b/include/linux/acpi_iort.h
@@ -38,6 +38,10 @@ int iort_dma_get_ranges(struct device *dev, u64 *size);
 int iort_iommu_configure_id(struct device *dev, const u32 *id_in);
 int iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head *head);
 phys_addr_t acpi_iort_dma_get_max_cpu_address(void);
+void iort_iommu_get_rmrs(struct fwnode_handle *iommu_fwnode, struct device *dev,
+			 struct list_head *list);
+void iort_iommu_put_rmrs(struct fwnode_handle *iommu_fwnode,
+			 struct list_head *list);
 #else
 static inline void acpi_iort_init(void) { }
 static inline u32 iort_msi_map_id(struct device *dev, u32 id)
@@ -57,6 +61,16 @@ int iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head *head)
 
 static inline phys_addr_t acpi_iort_dma_get_max_cpu_address(void)
 { return PHYS_ADDR_MAX; }
+
+static inline
+void iort_iommu_get_rmrs(struct fwnode_handle *iommu_fwnode, struct device *dev,
+			 struct list_head *list)
+{  }
+void iort_iommu_put_rmrs(struct fwnode_handle *iommu_fwnode,
+			 struct list_head *list)
+{ }
+
+{ }
 #endif
 
 #endif /* __ACPI_IORT_H__ */
-- 
2.25.1