From 6437b0b4ddcd258b400baec9d4601ba9e19e3faf Mon Sep 17 00:00:00 2001 From: Helge Deller Date: Mon, 5 Feb 2024 10:39:20 +0100 Subject: [PATCH] Revert "parisc: Only list existing CPUs in cpu_possible_mask" commit 82b143aeb169b8b55798d7d2063032e1a6ceeeb0 upstream. This reverts commit 0921244f6f4f0d05698b953fe632a99b38907226. It broke CPU hotplugging because it modifies the __cpu_possible_mask after bootup, so that it will be different than nr_cpu_ids, which then effictively breaks the workqueue setup code and triggers crashes when shutting down CPUs at runtime. Guenter was the first who noticed the wrong values in __cpu_possible_mask, since the cpumask Kunit tests were failig. Reverting this commit fixes both issues, but sadly brings back this uncritical runtime warning: register_cpu_capacity_sysctl: too early to get CPU4 device! Signed-off-by: Helge Deller Reported-by: Guenter Roeck Link: https://lkml.org/lkml/2024/2/4/146 Link: https://lore.kernel.org/lkml/Zb0mbHlIud_bqftx@slm.duckdns.org/t/ Cc: stable@vger.kernel.org # 6.0+ Signed-off-by: Greg Kroah-Hartman --- arch/parisc/kernel/processor.c | 8 -------- 1 file changed, 8 deletions(-) diff --git a/arch/parisc/kernel/processor.c b/arch/parisc/kernel/processor.c index 1f6c776d8081..c67883487ecd 100644 --- a/arch/parisc/kernel/processor.c +++ b/arch/parisc/kernel/processor.c @@ -171,7 +171,6 @@ static int __init processor_probe(struct parisc_device *dev) p->cpu_num = cpu_info.cpu_num; p->cpu_loc = cpu_info.cpu_loc; - set_cpu_possible(cpuid, true); store_cpu_topology(cpuid); #ifdef CONFIG_SMP @@ -466,13 +465,6 @@ static struct parisc_driver cpu_driver __refdata = { */ void __init processor_init(void) { - unsigned int cpu; - reset_cpu_topology(); - - /* reset possible mask. We will mark those which are possible. */ - for_each_possible_cpu(cpu) - set_cpu_possible(cpu, false); - register_parisc_driver(&cpu_driver); }