From dbce456280857f329af9069af5e48a9b6ebad146 Mon Sep 17 00:00:00 2001

From: Srikar Dronamraju <srikar@linux.vnet.ibm.com>

Date: Fri, 24 Jul 2020 16:28:09 +0530

Subject: [PATCH] powerpc/numa: Limit possible nodes to within

 num_possible_nodes

References: bsc#1209999 ltc#202140 bsc#1142685 ltc#179509 FATE#327775 git-fixes

Patch-mainline: v5.9-rc1

Git-commit: dbce456280857f329af9069af5e48a9b6ebad146

MAX_NUMNODES is a theoretical maximum number of nodes thats is

supported by the kernel. Device tree properties exposes the number of

possible nodes on the current platform. The kernel would detected this

and would use it for most of its resource allocations. If the platform

now increases the nodes to over what was already exposed, then it may

lead to inconsistencies. Hence limit it to the already exposed nodes.

Suggested-by: Nathan Lynch <nathanl@linux.ibm.com>

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Link: https://lore.kernel.org/r/20200724105809.24733-1-srikar@linux.vnet.ibm.com

Acked-by: Michal Suchanek <msuchanek@suse.de>

---

 arch/powerpc/mm/numa.c | 7 ++++---

 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c

index e437a9ac4956..92938393fec6 100644

--- a/arch/powerpc/mm/numa.c

+++ b/arch/powerpc/mm/numa.c

@@ -221,7 +221,8 @@ static void initialize_distance_lookup_table(int nid,

 	}

 }

-/* Returns nid in the range [0..MAX_NUMNODES-1], or -1 if no useful numa

+/*

+ * Returns nid in the range [0..nr_node_ids], or -1 if no useful NUMA

  * info is found.

  */

 static int associativity_to_nid(const __be32 *associativity)

@@ -235,7 +236,7 @@ static int associativity_to_nid(const __be32 *associativity)

 		nid = of_read_number(&associativity[min_common_depth], 1);

 	/* POWER4 LPAR uses 0xffff as invalid node */

-	if (nid == 0xffff || nid >= MAX_NUMNODES)

+	if (nid == 0xffff || nid >= nr_node_ids)

 		nid = NUMA_NO_NODE;

 	if (nid > 0 &&

@@ -448,7 +449,7 @@ static int of_drconf_to_nid_single(struct drmem_lmb *lmb)

 		index = lmb->aa_index * aa.array_sz + min_common_depth - 1;

 		nid = of_read_number(&aa.arrays[index], 1);

-		if (nid == 0xffff || nid >= MAX_NUMNODES)

+		if (nid == 0xffff || nid >= nr_node_ids)

 			nid = default_nid;

 		if (nid > 0) {

-- 

2.40.0