Once stop_machine() is gone from the CPU offline path, we won't be able to depend on preempt_disable() or local_irq_disable() to prevent CPUs from going offline from under us. Use the get/put_online_cpus_atomic() APIs to prevent CPUs from going offline, while invoking from atomic context. Cc: David Howells <dhowells@xxxxxxxxxx> Cc: Koichi Yasutake <yasutake.koichi@xxxxxxxxxxxxxxxx> Cc: linux-am33-list@xxxxxxxxxx Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@xxxxxxxxxxxxxxxxxx> --- arch/mn10300/kernel/smp.c | 2 ++ arch/mn10300/mm/cache-smp.c | 5 +++++ arch/mn10300/mm/tlb-smp.c | 15 +++++++++------ 3 files changed, 16 insertions(+), 6 deletions(-) diff --git a/arch/mn10300/kernel/smp.c b/arch/mn10300/kernel/smp.c index 5d7e152..9dfa172 100644 --- a/arch/mn10300/kernel/smp.c +++ b/arch/mn10300/kernel/smp.c @@ -349,9 +349,11 @@ void send_IPI_allbutself(int irq) { cpumask_t cpumask; + get_online_cpus_atomic(); cpumask_copy(&cpumask, cpu_online_mask); cpumask_clear_cpu(smp_processor_id(), &cpumask); send_IPI_mask(&cpumask, irq); + put_online_cpus_atomic(); } void arch_send_call_function_ipi_mask(const struct cpumask *mask) diff --git a/arch/mn10300/mm/cache-smp.c b/arch/mn10300/mm/cache-smp.c index 2d23b9e..47ca1c9 100644 --- a/arch/mn10300/mm/cache-smp.c +++ b/arch/mn10300/mm/cache-smp.c @@ -13,6 +13,7 @@ #include <linux/mman.h> #include <linux/threads.h> #include <linux/interrupt.h> +#include <linux/cpu.h> #include <asm/page.h> #include <asm/pgtable.h> #include <asm/processor.h> @@ -94,6 +95,8 @@ void smp_cache_call(unsigned long opr_mask, smp_cache_mask = opr_mask; smp_cache_start = start; smp_cache_end = end; + + get_online_cpus_atomic(); cpumask_copy(&smp_cache_ipi_map, cpu_online_mask); cpumask_clear_cpu(smp_processor_id(), &smp_cache_ipi_map); @@ -102,4 +105,6 @@ void smp_cache_call(unsigned long opr_mask, while (!cpumask_empty(&smp_cache_ipi_map)) /* nothing. lockup detection does not belong here */ mb(); + + put_online_cpus_atomic(); } diff --git a/arch/mn10300/mm/tlb-smp.c b/arch/mn10300/mm/tlb-smp.c index 3e57faf..d47304d 100644 --- a/arch/mn10300/mm/tlb-smp.c +++ b/arch/mn10300/mm/tlb-smp.c @@ -23,6 +23,7 @@ #include <linux/sched.h> #include <linux/profile.h> #include <linux/smp.h> +#include <linux/cpu.h> #include <asm/tlbflush.h> #include <asm/bitops.h> #include <asm/processor.h> @@ -105,6 +106,7 @@ static void flush_tlb_others(cpumask_t cpumask, struct mm_struct *mm, BUG_ON(cpumask_empty(&cpumask)); BUG_ON(cpumask_test_cpu(smp_processor_id(), &cpumask)); + get_online_cpus_atomic(); cpumask_and(&tmp, &cpumask, cpu_online_mask); BUG_ON(!cpumask_equal(&cpumask, &tmp)); @@ -134,6 +136,7 @@ static void flush_tlb_others(cpumask_t cpumask, struct mm_struct *mm, flush_mm = NULL; flush_va = 0; spin_unlock(&tlbstate_lock); + put_online_cpus_atomic(); } /** @@ -144,7 +147,7 @@ void flush_tlb_mm(struct mm_struct *mm) { cpumask_t cpu_mask; - preempt_disable(); + get_online_cpus_atomic(); cpumask_copy(&cpu_mask, mm_cpumask(mm)); cpumask_clear_cpu(smp_processor_id(), &cpu_mask); @@ -152,7 +155,7 @@ void flush_tlb_mm(struct mm_struct *mm) if (!cpumask_empty(&cpu_mask)) flush_tlb_others(cpu_mask, mm, FLUSH_ALL); - preempt_enable(); + put_online_cpus_atomic(); } /** @@ -163,7 +166,7 @@ void flush_tlb_current_task(void) struct mm_struct *mm = current->mm; cpumask_t cpu_mask; - preempt_disable(); + get_online_cpus_atomic(); cpumask_copy(&cpu_mask, mm_cpumask(mm)); cpumask_clear_cpu(smp_processor_id(), &cpu_mask); @@ -171,7 +174,7 @@ void flush_tlb_current_task(void) if (!cpumask_empty(&cpu_mask)) flush_tlb_others(cpu_mask, mm, FLUSH_ALL); - preempt_enable(); + put_online_cpus_atomic(); } /** @@ -184,7 +187,7 @@ void flush_tlb_page(struct vm_area_struct *vma, unsigned long va) struct mm_struct *mm = vma->vm_mm; cpumask_t cpu_mask; - preempt_disable(); + get_online_cpus_atomic(); cpumask_copy(&cpu_mask, mm_cpumask(mm)); cpumask_clear_cpu(smp_processor_id(), &cpu_mask); @@ -192,7 +195,7 @@ void flush_tlb_page(struct vm_area_struct *vma, unsigned long va) if (!cpumask_empty(&cpu_mask)) flush_tlb_others(cpu_mask, mm, va); - preempt_enable(); + put_online_cpus_atomic(); } /** -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html