1 files changed, 61 insertions, 0 deletions
diff --git a/src/device/resource_allocator_common.c b/src/device/resource_allocator_common.c
new file mode 100644
index 0000000000..202318bfe6
--- /dev/null
+++ b/src/device/resource_allocator_common.c
@@ -0,0 +1,61 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <console/console.h>
+#include <device/device.h>
+
+struct pick_largest_state {
+	struct resource *last;
+	const struct device *result_dev;
+	struct resource *result;
+	int seen_last;
+};
+
+static void pick_largest_resource(void *gp, struct device *dev,
+				  struct resource *resource)
+{
+	struct pick_largest_state *state = gp;
+	struct resource *last;
+
+	last = state->last;
+
+	/* Be certain to pick the successor to last. */
+	if (resource == last) {
+		state->seen_last = 1;
+		return;
+	}
+	if (resource->flags & IORESOURCE_FIXED)
+		return;	/* Skip it. */
+	if (last && ((last->align < resource->align) ||
+		     ((last->align == resource->align) &&
+		      (last->size < resource->size)) ||
+		     ((last->align == resource->align) &&
+		      (last->size == resource->size) && (!state->seen_last)))) {
+		return;
+	}
+	if (!state->result ||
+	    (state->result->align < resource->align) ||
+	    ((state->result->align == resource->align) &&
+	     (state->result->size < resource->size))) {
+		state->result_dev = dev;
+		state->result = resource;
+	}
+}
+
+const struct device *largest_resource(struct bus *bus,
+				      struct resource **result_res,
+				      unsigned long type_mask,
+				      unsigned long type)
+{
+	struct pick_largest_state state;
+
+	state.last = *result_res;
+	state.result_dev = NULL;
+	state.result = NULL;
+	state.seen_last = 0;
+
+	search_bus_resources(bus, type_mask, type, pick_largest_resource,
+			     &state);
+
+	*result_res = state.result;
+	return state.result_dev;
+}