device/device.h: Drop multiple links

Multiple links are unused throughout the tree and make the code more
confusing as an iteration over all busses is needed to get downstream
devices. This also not done consistently e.g. the allocator does not
care about multiple links on busses. A better way of dealing multiple
links below a device is to feature dummy devices with each their
respective bus.

This drops the sconfig capability to declare the same device multiple
times which was previously used to declare multiple links.

Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Change-Id: Iab6fe269faef46ae77ed1ea425440cf5c7dbd49b
Reviewed-on: https://review.coreboot.org/c/coreboot/+/78328
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Jincheng Li <jincheng.li@intel.com>
Reviewed-by: Lean Sheng Tan <sheng.tan@9elements.com>

1 files changed, 20 insertions, 80 deletions

diff --git a/src/device/device_util.c b/src/device/device_util.c
index 260c9b43eedc..ea4ef27f9f0b 100644
--- a/src/device/device_util.c
+++ b/src/device/device_util.c
@@ -560,16 +560,9 @@ void search_bus_resources(struct bus *bus, unsigned long type_mask,
 
 			/* If it is a subtractive resource recurse. */
 			if (res->flags & IORESOURCE_SUBTRACTIVE) {
-				struct bus *subbus;
-				for (subbus = curdev->link_list; subbus;
-				     subbus = subbus->next)
-					if (subbus->link_num
-					== IOINDEX_SUBTRACTIVE_LINK(res->index))
-						break;
-				if (!subbus) /* Why can subbus be NULL?  */
-					break;
-				search_bus_resources(subbus, type_mask, type,
-						     search, gp);
+				if (curdev->link_list)
+					search_bus_resources(curdev->link_list, type_mask, type,
+							     search, gp);
 				continue;
 			}
 			search(gp, curdev, res);
@@ -624,9 +617,8 @@ void disable_children(struct bus *bus)
 	struct device *child;
 
 	for (child = bus->children; child; child = child->sibling) {
-		struct bus *link;
-		for (link = child->link_list; link; link = link->next)
-			disable_children(link);
+		if (child->link_list)
+			disable_children(child->link_list);
 		dev_set_enabled(child, 0);
 	}
 }
@@ -637,7 +629,6 @@ void disable_children(struct bus *bus)
  */
 bool dev_is_active_bridge(struct device *dev)
 {
-	struct bus *link;
 	struct device *child;
 
 	if (!dev || !dev->enabled)
@@ -646,71 +637,20 @@ bool dev_is_active_bridge(struct device *dev)
 	if (!dev->link_list || !dev->link_list->children)
 		return 0;
 
-	for (link = dev->link_list; link; link = link->next) {
-		for (child = link->children; child; child = child->sibling) {
-			if (child->path.type == DEVICE_PATH_NONE)
-				continue;
-
-			if (child->enabled)
-				return 1;
-		}
+	for (child = dev->link_list->children; child; child = child->sibling) {
+		if (child->path.type == DEVICE_PATH_NONE)
+			continue;
+		if (child->enabled)
+			return 1;
 	}
 
 	return 0;
 }
 
-/**
- * Ensure the device has a minimum number of bus links.
- *
- * @param dev The device to add links to.
- * @param total_links The minimum number of links to have.
- */
-void add_more_links(struct device *dev, unsigned int total_links)
-{
-	struct bus *link, *last = NULL;
-	int link_num = -1;
-
-	for (link = dev->link_list; link; link = link->next) {
-		if (link_num < link->link_num)
-			link_num = link->link_num;
-		last = link;
-	}
-
-	if (last) {
-		int links = total_links - (link_num + 1);
-		if (links > 0) {
-			link = malloc(links * sizeof(*link));
-			if (!link)
-				die("Couldn't allocate more links!\n");
-			memset(link, 0, links * sizeof(*link));
-			last->next = link;
-		} else {
-			/* No more links to add */
-			return;
-		}
-	} else {
-		link = malloc(total_links * sizeof(*link));
-		if (!link)
-			die("Couldn't allocate more links!\n");
-		memset(link, 0, total_links * sizeof(*link));
-		dev->link_list = link;
-	}
-
-	for (link_num = link_num + 1; link_num < total_links; link_num++) {
-		link->link_num = link_num;
-		link->dev = dev;
-		link->next = link + 1;
-		last = link;
-		link = link->next;
-	}
-	last->next = NULL;
-}
-
 static void resource_tree(const struct device *root, int debug_level, int depth)
 {
 	int i = 0;
 	struct device *child;
-	struct bus *link;
 	struct resource *res;
 	char indent[30];	/* If your tree has more levels, it's wrong. */
 
@@ -732,10 +672,11 @@ static void resource_tree(const struct device *root, int debug_level, int depth)
 			  res->index);
 	}
 
-	for (link = root->link_list; link; link = link->next) {
-		for (child = link->children; child; child = child->sibling)
-			resource_tree(child, debug_level, depth + 1);
-	}
+	if (!root->link_list)
+		return;
+
+	for (child = root->link_list->children; child; child = child->sibling)
+		resource_tree(child, debug_level, depth + 1);
 }
 
 void print_resource_tree(const struct device *root, int debug_level,
@@ -760,7 +701,6 @@ void show_devs_tree(const struct device *dev, int debug_level, int depth)
 	char depth_str[20];
 	int i;
 	struct device *sibling;
-	struct bus *link;
 
 	for (i = 0; i < depth; i++)
 		depth_str[i] = ' ';
@@ -769,11 +709,11 @@ void show_devs_tree(const struct device *dev, int debug_level, int depth)
 	printk(debug_level, "%s%s: enabled %d\n",
 		  depth_str, dev_path(dev), dev->enabled);
 
-	for (link = dev->link_list; link; link = link->next) {
-		for (sibling = link->children; sibling;
-		     sibling = sibling->sibling)
-			show_devs_tree(sibling, debug_level, depth + 1);
-	}
+	if (!dev->link_list)
+		return;
+
+	for (sibling = dev->link_list->children; sibling; sibling = sibling->sibling)
+		show_devs_tree(sibling, debug_level, depth + 1);
 }
 
 void show_all_devs_tree(int debug_level, const char *msg)