[coreboot-gerrit] Change in coreboot[master]: util/sconfig: Fix illogical override rule for resource

[Nico Huber (Code Review)]

Nico Huber has submitted this change. ( https://review.coreboot.org/c/coreboot/+/37109 )

Change subject: util/sconfig: Fix illogical override rule for resource
......................................................................

util/sconfig: Fix illogical override rule for resource

The old logic only uses the type to identify resources, which makes a
resource in override tree overriding the first resource with the same
type (but possibly different index) in base tree, and resources with
same type (but again different index) in override tree overriding each
other.

Resources had better be identified with both their type and index.

Change-Id: I7cd88905a8d6d1c7c6c03833835df2fba83047ea
Signed-off-by: Bill XIE 
Reviewed-on: https://review.coreboot.org/c/coreboot/+/37109
Reviewed-by: Nico Huber 
Tested-by: build bot (Jenkins) 
---
M util/sconfig/main.c
1 file changed, 14 insertions(+), 5 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Nico Huber: Looks good to me, approved

diff --git a/util/sconfig/main.c b/util/sconfig/main.c
index 5c23333..3b60e2a 100644
--- a/util/sconfig/main.c
+++ b/util/sconfig/main.c
@@ -1073,6 +1073,16 @@
 }

/*
+ * Match resource nodes from base and override tree to see if they are the same
+ * node.
+ */
+static int res_match(struct resource *a, struct resource *b)
+{
+	return ((a->type == b->type) &&
+		(a->index == b->index));
+}
+
+/*
  * Walk through the override subtree in breadth-first manner starting at node to
  * see if chip_instance pointer of the node is same as chip_instance pointer of
  * override parent that is passed into the function. If yes, then update the
@@ -1104,8 +1114,7 @@
    struct resource *base_res = dev->res;

while (base_res) {
-		if (base_res->type == res->type) {
-			base_res->index = res->index;
+		if (res_match(base_res, res)) {
    		base_res->base = res->base;
    		return;
    	}
@@ -1195,9 +1204,9 @@
  * |                    |                                            |
  * | res                | Each resource that is present in override  |
  * |                    | device is copied over to base device:      |
- * |                    | 1. If resource of same type is present in  |
- * |                    |    base device, then index and base of the |
- * |                    |    resource is copied.                     |
+ * |                    | 1. If resource of same type and index is   |
+ * |                    |    present in base device, then base of    |
+ * |                    |    the resource is copied.                 |
  * |                    | 2. If not, then a new resource is allocated|
  * |                    |    under the base device using type, index |
  * |                    |    and base from override res.             |