[PATCH v6 2/3] powerpc/numa: Prefer node id queried from vphn

[Srikar Dronamraju]

Node id queried from the static device tree may not
be correct. For example: it may always show 0 on a shared processor.
Hence prefer the node id queried from vphn and fallback on the device tree
based node id if vphn query fails.

Cc: linuxppc-dev at lists.ozlabs.org
Cc: linux-mm at kvack.org
Cc: Michal Hocko <mhocko at suse.com>
Cc: Mel Gorman <mgorman at suse.de>
Cc: Vlastimil Babka <vbabka at suse.cz>
Cc: Christopher Lameter <cl at linux.com>
Cc: Michael Ellerman <mpe at ellerman.id.au>
Cc: Andrew Morton <akpm at linux-foundation.org>
Cc: Linus Torvalds <torvalds at linux-foundation.org>
Cc: Gautham R Shenoy <ego at linux.vnet.ibm.com>
Cc: Satheesh Rajendran <sathnaga at linux.vnet.ibm.com>
Cc: David Hildenbrand <david at redhat.com>
Cc: Aneesh Kumar KV <aneesh.kumar at linux.ibm.com>
Signed-off-by: Srikar Dronamraju <srikar at linux.vnet.ibm.com>
---
Changelog v2:->v3:
- Resolved comments from Gautham.
Link v2: https://lore.kernel.org/linuxppc-dev/20200428093836.27190-1-srikar@linux.vnet.ibm.com/t/#u

Changelog v1:->v2:
- Rebased to v5.7-rc3

 arch/powerpc/mm/numa.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index 72f6cca1332c..10c5064eeb88 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -728,21 +728,22 @@ static int __init parse_numa_properties(void)
 	 */
 	for_each_present_cpu(i) {
 		struct device_node *cpu;
-		int nid;
-
-		cpu = of_get_cpu_node(i, NULL);
-		BUG_ON(!cpu);
-		nid = of_node_to_nid_single(cpu);
-		of_node_put(cpu);
+		int nid = vphn_get_nid(i);
 
 		/*
 		 * Don't fall back to default_nid yet -- we will plug
 		 * cpus into nodes once the memory scan has discovered
 		 * the topology.
 		 */
-		if (nid < 0)
-			continue;
-		node_set_online(nid);
+		if (nid == NUMA_NO_NODE) {
+			cpu = of_get_cpu_node(i, NULL);
+			BUG_ON(!cpu);
+			nid = of_node_to_nid_single(cpu);
+			of_node_put(cpu);
+		}
+
+		if (likely(nid > 0))
+			node_set_online(nid);
 	}
 
 	get_n_mem_cells(&n_mem_addr_cells, &n_mem_size_cells);
-- 
2.18.1