6.6-stable review patch. If anyone has any objections, please let me know.
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From: Danil Skrebenkov danil.skrebenkov@cloudbear.ru
[ Upstream commit ae9e9f3d67dcef7582a4524047b01e33c5185ddb ]
openSBI v1.7 adds harts checks for ipi operations. Especially it adds comparison between hmask passed as an argument from linux and mask of online harts (from openSBI side). If they don't fit each other the error occurs.
When cpu is offline, cpu_online_mask is explicitly cleared in __cpu_disable. However, there is no explicit clearing of mm_cpumask. mm_cpumask is used for rfence operations that call openSBI RFENCE extension which uses ipi to remote harts. If hart is offline there may be error if mask of linux is not as mask of online harts in openSBI.
this patch adds explicit clearing of mm_cpumask for offline hart.
Signed-off-by: Danil Skrebenkov danil.skrebenkov@cloudbear.ru Reviewed-by: Andrew Jones ajones@ventanamicro.com Link: https://lore.kernel.org/r/20250919132849.31676-1-danil.skrebenkov@cloudbear.... [pjw@kernel.org: rewrote subject line for clarity] Signed-off-by: Paul Walmsley pjw@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- arch/riscv/kernel/cpu-hotplug.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/arch/riscv/kernel/cpu-hotplug.c b/arch/riscv/kernel/cpu-hotplug.c index 6b710ef9d9aef..2114903ee3ad4 100644 --- a/arch/riscv/kernel/cpu-hotplug.c +++ b/arch/riscv/kernel/cpu-hotplug.c @@ -61,6 +61,7 @@ void arch_cpuhp_cleanup_dead_cpu(unsigned int cpu)
pr_notice("CPU%u: off\n", cpu);
+ clear_tasks_mm_cpumask(cpu); /* Verify from the firmware if the cpu is really stopped*/ if (cpu_ops[cpu]->cpu_is_stopped) ret = cpu_ops[cpu]->cpu_is_stopped(cpu);