[PATCH 6.12.y 2/2] LoongArch: Don't init & online empty nodes

[Sasha Levin <sashal@kernel.org>]

From: Huacai Chen <chenhuacai@loongson.cn>

[ Upstream commit 87c6d144bc7bbed0c4573848b9c92006edca7848 ]

Don't init & online empty nodes without any CPU cores (and memory), in
this way "lscpu" will not display confusing empty nodes.

Modify fake_numa_init() to make sure at least Node-0 isn't empty for the
FDT booting case.

Cc: stable@vger.kernel.org
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/loongarch/kernel/numa.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/arch/loongarch/kernel/numa.c b/arch/loongarch/kernel/numa.c
index aefe9984be794..7c0ae91cb395f 100644
--- a/arch/loongarch/kernel/numa.c
+++ b/arch/loongarch/kernel/numa.c
@@ -318,6 +318,8 @@ static int __init fake_numa_init(void)
 	phys_addr_t start = memblock_start_of_DRAM();
 	phys_addr_t end = memblock_end_of_DRAM() - 1;
 
+	set_cpuid_to_node(0, 0);
+	early_numa_add_cpu(0, 0);
 	pr_info("Faking a node at [mem %pap-%pap]\n", &start, &end);
 
 	return numa_add_memblk(0, start, end + 1);
@@ -352,8 +354,10 @@ int __init init_numa_memory(void)
 		return -EINVAL;
 
 	for_each_node_mask(node, node_possible_map) {
-		node_mem_init(node);
-		node_set_online(node);
+		if (!cpumask_empty(&cpus_on_node[node])) {
+			node_mem_init(node);
+			node_set_online(node);
+		}
 	}
 	max_low_pfn = PHYS_PFN(memblock_end_of_DRAM());
 
-- 
2.53.0