1 files changed, 61 insertions, 12 deletions

diff --git a/kernel/resource.c b/kernel/resource.c
index e4e9bac12e6e..31341bdd7707 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -48,6 +48,14 @@ struct resource iomem_resource = {
 };
 EXPORT_SYMBOL(iomem_resource);
 
+struct resource soft_reserve_resource = {
+	.name	= "Soft Reserved",
+	.start	= 0,
+	.end	= -1,
+	.desc	= IORES_DESC_SOFT_RESERVED,
+	.flags	= IORESOURCE_MEM,
+};
+
 static DEFINE_RWLOCK(resource_lock);
 
 /*
@@ -82,7 +90,7 @@ static struct resource *next_resource(struct resource *p, bool skip_children,
 
 #ifdef CONFIG_PROC_FS
 
-enum { MAX_IORES_LEVEL = 5 };
+enum { MAX_IORES_LEVEL = 8 };
 
 static void *r_start(struct seq_file *m, loff_t *pos)
 	__acquires(resource_lock)
@@ -321,13 +329,14 @@ static bool is_type_match(struct resource *p, unsigned long flags, unsigned long
 }
 
 /**
- * find_next_iomem_res - Finds the lowest iomem resource that covers part of
- *			 [@start..@end].
+ * find_next_res - Finds the lowest resource that covers part of
+ *		   [@start..@end].
  *
  * If a resource is found, returns 0 and @*res is overwritten with the part
  * of the resource that's within [@start..@end]; if none is found, returns
  * -ENODEV.  Returns -EINVAL for invalid parameters.
  *
+ * @parent:	resource tree root to search
  * @start:	start address of the resource searched for
  * @end:	end address of same resource
  * @flags:	flags which the resource must have
@@ -337,9 +346,9 @@ static bool is_type_match(struct resource *p, unsigned long flags, unsigned long
  * The caller must specify @start, @end, @flags, and @desc
  * (which may be IORES_DESC_NONE).
  */
-static int find_next_iomem_res(resource_size_t start, resource_size_t end,
-			       unsigned long flags, unsigned long desc,
-			       struct resource *res)
+static int find_next_res(struct resource *parent, resource_size_t start,
+			 resource_size_t end, unsigned long flags,
+			 unsigned long desc, struct resource *res)
 {
 	/* Skip children until we find a top level range that matches */
 	bool skip_children = true;
@@ -353,7 +362,7 @@ static int find_next_iomem_res(resource_size_t start, resource_size_t end,
 
 	read_lock(&resource_lock);
 
-	for_each_resource(&iomem_resource, p, skip_children) {
+	for_each_resource(parent, p, skip_children) {
 		/* If we passed the resource we are looking for, stop */
 		if (p->start > end) {
 			p = NULL;
@@ -390,16 +399,23 @@ static int find_next_iomem_res(resource_size_t start, resource_size_t end,
 	return p ? 0 : -ENODEV;
 }
 
-static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end,
-				 unsigned long flags, unsigned long desc,
-				 void *arg,
-				 int (*func)(struct resource *, void *))
+static int find_next_iomem_res(resource_size_t start, resource_size_t end,
+			       unsigned long flags, unsigned long desc,
+			       struct resource *res)
+{
+	return find_next_res(&iomem_resource, start, end, flags, desc, res);
+}
+
+static int walk_res_desc(struct resource *parent, resource_size_t start,
+			 resource_size_t end, unsigned long flags,
+			 unsigned long desc, void *arg,
+			 int (*func)(struct resource *, void *))
 {
 	struct resource res;
 	int ret = -EINVAL;
 
 	while (start < end &&
-	       !find_next_iomem_res(start, end, flags, desc, &res)) {
+	       !find_next_res(parent, start, end, flags, desc, &res)) {
 		ret = (*func)(&res, arg);
 		if (ret)
 			break;
@@ -410,6 +426,15 @@ static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end,
 	return ret;
 }
 
+static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end,
+				 unsigned long flags, unsigned long desc,
+				 void *arg,
+				 int (*func)(struct resource *, void *))
+{
+	return walk_res_desc(&iomem_resource, start, end, flags, desc, arg, func);
+}
+
+
 /**
  * walk_iomem_res_desc - Walks through iomem resources and calls func()
  *			 with matching resource ranges.
@@ -435,6 +460,18 @@ int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start,
 EXPORT_SYMBOL_GPL(walk_iomem_res_desc);
 
 /*
+ * In support of device drivers claiming Soft Reserved resources, walk the Soft
+ * Reserved resource deferral tree.
+ */
+int walk_soft_reserve_res(u64 start, u64 end, void *arg,
+			  int (*func)(struct resource *, void *))
+{
+	return walk_res_desc(&soft_reserve_resource, start, end, IORESOURCE_MEM,
+			     IORES_DESC_SOFT_RESERVED, arg, func);
+}
+EXPORT_SYMBOL_GPL(walk_soft_reserve_res);
+
+/*
  * This function calls the @func callback against all memory ranges of type
  * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
  * Now, this function is only for System RAM, it deals with full ranges and
@@ -656,6 +693,18 @@ int region_intersects(resource_size_t start, size_t size, unsigned long flags,
 }
 EXPORT_SYMBOL_GPL(region_intersects);
 
+/*
+ * Check if the provided range is registered in the Soft Reserved resource
+ * deferral tree for driver consideration.
+ */
+int region_intersects_soft_reserve(resource_size_t start, size_t size)
+{
+	guard(read_lock)(&resource_lock);
+	return __region_intersects(&soft_reserve_resource, start, size,
+				   IORESOURCE_MEM, IORES_DESC_SOFT_RESERVED);
+}
+EXPORT_SYMBOL_GPL(region_intersects_soft_reserve);
+
 void __weak arch_remove_reservations(struct resource *avail)
 {
 }