@@ -969,8 +969,12 @@ void __init setup_arch(char **cmdline_p)
klp_init_thread_info(&init_task);
setup_initial_init_mm(_stext, _etext, _edata, _end);
-
+ /* sched_init() does the mmgrab(&init_mm) for the primary CPU */
+ VM_WARN_ON(cpumask_test_cpu(smp_processor_id(), mm_cpumask(&init_mm)));
+ cpumask_set_cpu(smp_processor_id(), mm_cpumask(&init_mm));
+ inc_mm_active_cpus(&init_mm);
mm_iommu_init(&init_mm);
+
irqstack_early_init();
exc_lvl_early_init();
emergency_stack_init();
@@ -47,6 +47,7 @@
#include <asm/smp.h>
#include <asm/time.h>
#include <asm/machdep.h>
+#include <asm/mmu_context.h>
#include <asm/cputhreads.h>
#include <asm/cputable.h>
#include <asm/mpic.h>
@@ -1615,6 +1616,9 @@ void start_secondary(void *unused)
mmgrab_lazy_tlb(&init_mm);
current->active_mm = &init_mm;
+ VM_WARN_ON(cpumask_test_cpu(smp_processor_id(), mm_cpumask(&init_mm)));
+ cpumask_set_cpu(cpu, mm_cpumask(&init_mm));
+ inc_mm_active_cpus(&init_mm);
smp_store_cpu_info(cpu);
set_dec(tb_ticks_per_jiffy);
@@ -1750,6 +1754,14 @@ int __cpu_disable(void)
void __cpu_die(unsigned int cpu)
{
+ /*
+ * This could perhaps be a generic call in idlea_task_dead(), but
+ * that requires testing from all archs, so first put it here to
+ */
+ VM_WARN_ON_ONCE(!cpumask_test_cpu(cpu, mm_cpumask(&init_mm)));
+ dec_mm_active_cpus(&init_mm);
+ cpumask_clear_cpu(cpu, mm_cpumask(&init_mm));
+
if (smp_ops->cpu_die)
smp_ops->cpu_die(cpu);
}
@@ -47,6 +47,7 @@ void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
/* Mark this context has been used on the new CPU */
if (!cpumask_test_cpu(smp_processor_id(), mm_cpumask(next))) {
+ VM_WARN_ON_ONCE(next == &init_mm);
cpumask_set_cpu(smp_processor_id(), mm_cpumask(next));
inc_mm_active_cpus(next);
init_mm mm_cpumask and context.active_cpus is not maintained at boot and hotplug. This seems to be harmless because init_mm does not have a userspace and so never gets user TLBs flushed, but it looks odd and it prevents some sanity checks being added. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> --- arch/powerpc/kernel/setup-common.c | 6 +++++- arch/powerpc/kernel/smp.c | 12 ++++++++++++ arch/powerpc/mm/mmu_context.c | 1 + 3 files changed, 18 insertions(+), 1 deletion(-)