From ffbe5d21d10f9c7890c07fca17db772f941385bf Mon Sep 17 00:00:00 2001
From: Nicholas Piggin <npiggin@gmail.com>
Date: Thu, 2 Dec 2021 00:41:46 +1000
Subject: [PATCH] powerpc/64: pcpu setup avoid reading mmu_linear_psize on 64e
or radix
References: bsc#1204413 ltc#200176
Patch-mainline: v5.17-rc1
Git-commit: ffbe5d21d10f9c7890c07fca17db772f941385bf
Radix never sets mmu_linear_psize so it's always 4K, which causes pcpu
atom_size to always be PAGE_SIZE. 64e sets it to 1GB always.
Make paths for these platforms to be explicit about what value they set
atom_size to.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211201144153.2456614-12-npiggin@gmail.com
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
arch/powerpc/kernel/setup_64.c | 21 +++++++++++++++------
1 file changed, 15 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 6052f5d5ded3..9a493796ce66 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -880,14 +880,23 @@ void __init setup_per_cpu_areas(void)
int rc = -EINVAL;
/*
- * Linear mapping is one of 4K, 1M and 16M. For 4K, no need
- * to group units. For larger mappings, use 1M atom which
- * should be large enough to contain a number of units.
+ * BookE and BookS radix are historical values and should be revisited.
*/
- if (mmu_linear_psize == MMU_PAGE_4K)
+ if (IS_ENABLED(CONFIG_PPC_BOOK3E)) {
+ atom_size = SZ_1M;
+ } else if (radix_enabled()) {
atom_size = PAGE_SIZE;
- else
- atom_size = 1 << 20;
+ } else {
+ /*
+ * Linear mapping is one of 4K, 1M and 16M. For 4K, no need
+ * to group units. For larger mappings, use 1M atom which
+ * should be large enough to contain a number of units.
+ */
+ if (mmu_linear_psize == MMU_PAGE_4K)
+ atom_size = PAGE_SIZE;
+ else
+ atom_size = SZ_1M;
+ }
if (pcpu_chosen_fc != PCPU_FC_PAGE) {
rc = pcpu_embed_first_chunk(0, dyn_size, atom_size, pcpu_cpu_distance,
--
2.35.3