From: Thierry Reding <treding@nvidia.com>
Date: Fri, 3 Apr 2020 19:46:57 +0200
Subject: of: reserved-memory: Support multiple regions per device

Git-commit: 081df76a040df3e31e78df4ca9106eb114dabc6a
Patch-mainline: v5.8-rc1
References: jsc#SLE-15847

While the lookup/initialization code already supports multiple memory
regions per device, the release code will only ever release the first
matching memory region.

Enhance the code to release all matching regions. Each attachment of
a region to a device is uniquely identifiable using a struct device
pointer and a pointer to the memory region's struct reserved_mem.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@suse.com>
---
 drivers/of/of_reserved_mem.c | 22 ++++++++++------------
 1 file changed, 10 insertions(+), 12 deletions(-)

diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
index ed2ff6f01d32..f61e8739502a 100644
--- a/drivers/of/of_reserved_mem.c
+++ b/drivers/of/of_reserved_mem.c
@@ -385,24 +385,22 @@ EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_name);
  */
 void of_reserved_mem_device_release(struct device *dev)
 {
-	struct rmem_assigned_device *rd;
-	struct reserved_mem *rmem = NULL;
+	struct rmem_assigned_device *rd, *tmp;
+	LIST_HEAD(release_list);
 
 	mutex_lock(&of_rmem_assigned_device_mutex);
-	list_for_each_entry(rd, &of_rmem_assigned_device_list, list) {
-		if (rd->dev == dev) {
-			rmem = rd->rmem;
-			list_del(&rd->list);
-			kfree(rd);
-			break;
-		}
+	list_for_each_entry_safe(rd, tmp, &of_rmem_assigned_device_list, list) {
+		if (rd->dev == dev)
+			list_move_tail(&rd->list, &release_list);
 	}
 	mutex_unlock(&of_rmem_assigned_device_mutex);
 
-	if (!rmem || !rmem->ops || !rmem->ops->device_release)
-		return;
+	list_for_each_entry_safe(rd, tmp, &release_list, list) {
+		if (rd->rmem && rd->rmem->ops && rd->rmem->ops->device_release)
+			rd->rmem->ops->device_release(rd->rmem, dev);
 
-	rmem->ops->device_release(rmem, dev);
+		kfree(rd);
+	}
 }
 EXPORT_SYMBOL_GPL(of_reserved_mem_device_release);
 
-- 
2.26.2