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: Paul Mundt <let...@linux-sh.org> Cc: linux...@vger.kernel.org Signed-off-by: Srivatsa S. Bhat <srivatsa.b...@linux.vnet.ibm.com> --- arch/sh/kernel/smp.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/arch/sh/kernel/smp.c b/arch/sh/kernel/smp.c index 2062aa8..232fabe 100644 --- a/arch/sh/kernel/smp.c +++ b/arch/sh/kernel/smp.c @@ -357,7 +357,7 @@ static void flush_tlb_mm_ipi(void *mm) */ void flush_tlb_mm(struct mm_struct *mm) { - preempt_disable(); + get_online_cpus_atomic(); if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) { smp_call_function(flush_tlb_mm_ipi, (void *)mm, 1); @@ -369,7 +369,7 @@ void flush_tlb_mm(struct mm_struct *mm) } local_flush_tlb_mm(mm); - preempt_enable(); + put_online_cpus_atomic(); } struct flush_tlb_data { @@ -390,7 +390,7 @@ void flush_tlb_range(struct vm_area_struct *vma, { struct mm_struct *mm = vma->vm_mm; - preempt_disable(); + get_online_cpus_atomic(); if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) { struct flush_tlb_data fd; @@ -405,7 +405,7 @@ void flush_tlb_range(struct vm_area_struct *vma, cpu_context(i, mm) = 0; } local_flush_tlb_range(vma, start, end); - preempt_enable(); + put_online_cpus_atomic(); } static void flush_tlb_kernel_range_ipi(void *info) @@ -433,7 +433,7 @@ static void flush_tlb_page_ipi(void *info) void flush_tlb_page(struct vm_area_struct *vma, unsigned long page) { - preempt_disable(); + get_online_cpus_atomic(); if ((atomic_read(&vma->vm_mm->mm_users) != 1) || (current->mm != vma->vm_mm)) { struct flush_tlb_data fd; @@ -448,7 +448,7 @@ void flush_tlb_page(struct vm_area_struct *vma, unsigned long page) cpu_context(i, vma->vm_mm) = 0; } local_flush_tlb_page(vma, page); - preempt_enable(); + put_online_cpus_atomic(); } static void flush_tlb_one_ipi(void *info) _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev