nb/amd/pi/00730F01/northbridge: rework hw_mem_hole_info

This APU is always a single-node and also only has one DRAM controller,
so we don't need to loop over the different nodes to find the memory
hole below 4GB. We also don't need to check for the special case where
the memory hole is non-DRAM address space between the parts of the
address space decoded by different DRAM controllers.

TEST=PC Engines APU2 still boots and doesn't show any new problems

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: I9793d911d2d496be49168c06d83ceb802bc2b647
Reviewed-on: https://review.coreboot.org/c/coreboot/+/79606
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: Nico Huber <nico.h@gmx.de>
diff --git a/src/northbridge/amd/pi/00730F01/northbridge.c b/src/northbridge/amd/pi/00730F01/northbridge.c
index d138387..eb2f71d 100644
--- a/src/northbridge/amd/pi/00730F01/northbridge.c
+++ b/src/northbridge/amd/pi/00730F01/northbridge.c
@@ -33,11 +33,6 @@
 	return pcidev_on_root(DEV_CDB + nodeid, fn);
 }
 
-static unsigned int get_node_nums(void)
-{
-	return 1;
-}
-
 static int get_dram_base_limit(u32 nodeid, resource_t *basek, resource_t *limitk)
 {
 	u32 temp;
@@ -573,38 +568,15 @@
 static struct hw_mem_hole_info get_hw_mem_hole_info(void)
 {
 	struct hw_mem_hole_info mem_hole;
-	int i;
 	mem_hole.hole_startk = CONFIG_HW_MEM_HOLE_SIZEK;
 	mem_hole.node_id = -1;
-	for (i = 0; i < get_node_nums(); i++) {
-		resource_t basek, limitk;
-		u32 hole;
-		if (!get_dram_base_limit(i, &basek, &limitk))
-			continue; // no memory on this node
-		hole = pci_read_config32(get_node_pci(i, 1), 0xf0);
+
+	resource_t basek, limitk;
+	if (get_dram_base_limit(0, &basek, &limitk)) { // memory on this node
+		u32 hole = pci_read_config32(get_node_pci(0, 1), 0xf0);
 		if (hole & 2) { // we find the hole
 			mem_hole.hole_startk = (hole & (0xff << 24)) >> 10;
-			mem_hole.node_id = i; // record the node No with hole
-			break; // only one hole
-		}
-	}
-
-	/* We need to double check if there is special set on base reg and limit reg
-	 * are not continuous instead of hole, it will find out its hole_startk.
-	 */
-	if (mem_hole.node_id == -1) {
-		resource_t limitk_pri = 0;
-		for (i = 0; i < get_node_nums(); i++) {
-			resource_t base_k, limit_k;
-			if (!get_dram_base_limit(i, &base_k, &limit_k))
-				continue; // no memory on this node
-			if (base_k > 4 * 1024 * 1024) break; // don't need to go to check
-			if (limitk_pri != base_k) { // we find the hole
-				mem_hole.hole_startk = (unsigned int)limitk_pri; // must be below 4G
-				mem_hole.node_id = i;
-				break; //only one hole
-			}
-			limitk_pri = limit_k;
+			mem_hole.node_id = 0; // record the node No with hole
 		}
 	}
 	return mem_hole;