resource: Clean it up a bit

- Drop BUG_ON()s and do normal error handling instead, in
  find_next_iomem_res().

- Align function arguments on opening braces.

- Get rid of local var sibling_only in find_next_iomem_res().

- Shorten unnecessarily long first_level_children_only arg name.
Signed-off-by: Borislav Petkov <bp@suse.de>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Bjorn Helgaas <bhelgaas@google.com>
CC: Brijesh Singh <brijesh.singh@amd.com>
CC: Dan Williams <dan.j.williams@intel.com>
CC: H. Peter Anvin <hpa@zytor.com>
CC: Lianbo Jiang <lijiang@redhat.com>
CC: Takashi Iwai <tiwai@suse.de>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Tom Lendacky <thomas.lendacky@amd.com>
CC: Vivek Goyal <vgoyal@redhat.com>
CC: Yaowei Bai <baiyaowei@cmss.chinamobile.com>
CC: bhe@redhat.com
CC: dan.j.williams@intel.com
CC: dyoung@redhat.com
CC: kexec@lists.infradead.org
CC: mingo@redhat.com
Link: <new submission>

kernel/resource.c

@@ -328,25 +328,23 @@ EXPORT_SYMBOL(release_resource);
  * -1.
  *
  * This function walks the whole tree and not just first level children
- * unless @first_level_children_only is true.
+ * unless @first_lvl is true.
  */
 static int find_next_iomem_res(resource_size_t start, resource_size_t end,
 			       unsigned long flags, unsigned long desc,
-			       bool first_level_children_only,
-			       struct resource *res)
+			       bool first_lvl, struct resource *res)
 {
 	struct resource *p;
-	bool sibling_only = false;
 
-	BUG_ON(!res);
-	BUG_ON(start >= end);
+	if (!res)
+		return -EINVAL;
 
-	if (first_level_children_only)
-		sibling_only = true;
+	if (start >= end)
+		return -EINVAL;
 
 	read_lock(&resource_lock);
 
-	for (p = iomem_resource.child; p; p = next_resource(p, sibling_only)) {
+	for (p = iomem_resource.child; p; p = next_resource(p, first_lvl)) {
 		if ((p->flags & flags) != flags)
 			continue;
 		if ((desc != IORES_DESC_NONE) && (desc != p->desc))
@@ -373,15 +371,14 @@ static int find_next_iomem_res(resource_size_t start, resource_size_t end,
 
 static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end,
 				 unsigned long flags, unsigned long desc,
-				 bool first_level_children_only, void *arg,
+				 bool first_lvl, void *arg,
 				 int (*func)(struct resource *, void *))
 {
 	struct resource res;
 	int ret = -1;
 
 	while (start < end &&
-	       !find_next_iomem_res(start, end, flags, desc,
-				    first_level_children_only, &res)) {
+	       !find_next_iomem_res(start, end, flags, desc, first_lvl, &res)) {
 		ret = (*func)(&res, arg);
 		if (ret)
 			break;
@@ -392,7 +389,7 @@ static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end,
 	return ret;
 }
 
-/*
+/**
  * Walks through iomem resources and calls func() with matching resource
  * ranges. This walks through whole tree and not just first level children.
  * All the memory ranges which overlap start,end and also match flags and
@@ -971,9 +968,9 @@ int adjust_resource(struct resource *res, resource_size_t start,
 }
 EXPORT_SYMBOL(adjust_resource);
 
-static void __init __reserve_region_with_split(struct resource *root,
-		resource_size_t start, resource_size_t end,
-		const char *name)
+static void __init
+__reserve_region_with_split(struct resource *root, resource_size_t start,
+			    resource_size_t end, const char *name)
 {
 	struct resource *parent = root;
 	struct resource *conflict;
@@ -1032,9 +1029,9 @@ static void __init __reserve_region_with_split(struct resource *root,
 
 }
 
-void __init reserve_region_with_split(struct resource *root,
-		resource_size_t start, resource_size_t end,
-		const char *name)
+void __init
+reserve_region_with_split(struct resource *root, resource_size_t start,
+			  resource_size_t end, const char *name)
 {
 	int abort = 0;
 
@@ -1398,9 +1395,9 @@ static int devm_region_match(struct device *dev, void *res, void *match_data)
 		this->start == match->start && this->n == match->n;
 }
 
-struct resource * __devm_request_region(struct device *dev,
-				struct resource *parent, resource_size_t start,
-				resource_size_t n, const char *name)
+struct resource *
+__devm_request_region(struct device *dev, struct resource *parent,
+		      resource_size_t start, resource_size_t n, const char *name)
 {
 	struct region_devres *dr = NULL;
 	struct resource *res;