[PATCH 4.9 46/96] xtensa: SMP: limit number of possible CPUs by NR_CPUS

Greg Kroah-Hartman
2019-03-12T17:20:09Z

[ Upstream commit 25384ce5f9530def39421597b1457d9462df6455 ]

This fixes the following warning at boot when the kernel is booted on a
board with more CPU cores than was configured in NR_CPUS:

smp_init_cpus: Core Count = 8
smp_init_cpus: Core Id = 0
------------[ cut here ]------------
WARNING: CPU: 0 PID: 0 at include/linux/cpumask.h:121 smp_init_cpus+0x54/0x74
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 5.0.0-rc3-00015-g1459333f88a0 #124
Call Trace:
__warn$part$3+0x6a/0x7c
warn_slowpath_null+0x35/0x3c
smp_init_cpus+0x54/0x74
setup_arch+0x1c0/0x1d0
start_kernel+0x44/0x310
_startup+0x107/0x107

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/xtensa/kernel/smp.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/arch/xtensa/kernel/smp.c b/arch/xtensa/kernel/smp.c
index 8329891071aa..44805673a250 100644
--- a/arch/xtensa/kernel/smp.c
+++ b/arch/xtensa/kernel/smp.c
@@ -93,6 +93,11 @@ void __init smp_init_cpus(void)
pr_info("%s: Core Count = %d\n", __func__, ncpus);
pr_info("%s: Core Id = %d\n", __func__, core_id);

+ if (ncpus > NR_CPUS) {
+ ncpus = NR_CPUS;
+ pr_info("%s: limiting core count by %d\n", __func__, ncpus);
+ }
+
for (i = 0; i < ncpus; ++i)
set_cpu_possible(i, true);
}
--
2.19.1