x86: xen: use smp_call_function_many()

Impact: use new API, remove cpumask from stack.

Change smp_call_function_mask() callers to smp_call_function_many().

This removes a cpumask from the stack, and falls back should allocating
the cpumask var fail (only possible with CONFIG_CPUMASKS_OFFSTACK).

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Mike Travis <travis@sgi.com>
Cc: jeremy@xensource.com

1 files changed, 15 insertions, 5 deletions

diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 636ef4caa52d..e59e53b11e2b 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -1079,7 +1079,7 @@ static void drop_other_mm_ref(void *info)
 
 static void xen_drop_mm_ref(struct mm_struct *mm)
 {
-        cpumask_t mask;
+        cpumask_var_t mask;
         unsigned cpu;
 
         if (current->active_mm == mm) {
@@ -1091,7 +1091,16 @@ static void xen_drop_mm_ref(struct mm_struct *mm)
         }
 
         /* Get the "official" set of cpus referring to our pagetable. */
-        mask = mm->cpu_vm_mask;
+        if (!alloc_cpumask_var(&mask, GFP_ATOMIC)) {
+                for_each_online_cpu(cpu) {
+                        if (!cpumask_test_cpu(cpu, &mm->cpu_vm_mask)
+                            && per_cpu(xen_current_cr3, cpu) != __pa(mm->pgd))
+                                continue;
+                        smp_call_function_single(cpu, drop_other_mm_ref, mm, 1);
+                }
+                return;
+        }
+        cpumask_copy(mask, &mm->cpu_vm_mask);
 
         /* It's possible that a vcpu may have a stale reference to our
            cr3, because its in lazy mode, and it hasn't yet flushed
@@ -1100,11 +1109,12 @@ static void xen_drop_mm_ref(struct mm_struct *mm)
            if needed. */
         for_each_online_cpu(cpu) {
                 if (per_cpu(xen_current_cr3, cpu) == __pa(mm->pgd))
-                        cpu_set(cpu, mask);
+                        cpumask_set_cpu(cpu, mask);
         }
 
-        if (!cpus_empty(mask))
-                smp_call_function_mask(mask, drop_other_mm_ref, mm, 1);
+        if (!cpumask_empty(mask))
+                smp_call_function_many(mask, drop_other_mm_ref, mm, 1);
+        free_cpumask_var(mask);
 }
 #else
 static void xen_drop_mm_ref(struct mm_struct *mm)