[PATCH v3 5/8] resource: Handle simple alignment inside __find_resource_space()

[Ilpo Järvinen]

allocate_resource() accepts ->alignf() callback to perform custom
alignment beyond constraint->align. If alignf is NULL,
simple_align_resource() is used which only returns avail->start (no
change).

Using avail->start directly is natural and can be done with a
conditional in __find_resource_space() instead which avoids
unnecessarily using callback. It makes the code inside
__find_resource_space() more obvious and removes the need for the
caller to provide constraint->alignf unnecessarily.

This is preparation for exporting find_resource_space().

Tested-by: Lidong Wang <lidong.wang@xxxxxxxxx>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Reviewed-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
---
 kernel/resource.c | 20 +++++++-------------
 1 file changed, 7 insertions(+), 13 deletions(-)

diff --git a/kernel/resource.c b/kernel/resource.c
index 26ad6f223652..35c44c23b037 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -621,14 +621,6 @@ void __weak arch_remove_reservations(struct resource *avail)
 {
 }
 
-static resource_size_t simple_align_resource(void *data,
-					     const struct resource *avail,
-					     resource_size_t size,
-					     resource_size_t align)
-{
-	return avail->start;
-}
-
 static void resource_clip(struct resource *res, resource_size_t min,
 			  resource_size_t max)
 {
@@ -648,6 +640,7 @@ static int __find_resource_space(struct resource *root, struct resource *old,
 {
 	struct resource *this = root->child;
 	struct resource tmp = *new, avail, alloc;
+	resource_alignf alignf = constraint->alignf;
 
 	tmp.start = root->start;
 	/*
@@ -676,8 +669,12 @@ static int __find_resource_space(struct resource *root, struct resource *old,
 		avail.flags = new->flags & ~IORESOURCE_UNSET;
 		if (avail.start >= tmp.start) {
 			alloc.flags = avail.flags;
-			alloc.start = constraint->alignf(constraint->alignf_data, &avail,
-					size, constraint->align);
+			if (alignf) {
+				alloc.start = alignf(constraint->alignf_data,
+						     &avail, size, constraint->align);
+			} else {
+				alloc.start = avail.start;
+			}
 			alloc.end = alloc.start + size - 1;
 			if (alloc.start <= alloc.end &&
 			    resource_contains(&avail, &alloc)) {
@@ -788,9 +785,6 @@ int allocate_resource(struct resource *root, struct resource *new,
 	int err;
 	struct resource_constraint constraint;
 
-	if (!alignf)
-		alignf = simple_align_resource;
-
 	constraint.min = min;
 	constraint.max = max;
 	constraint.align = align;
-- 
2.39.2