Remove many uses of cpu_possible_map and iterators over NR_CPUS.

The significant remaining culprits for x86 are credit2, hpet, and
percpu-area subsystems. To be dealt with in a separate patch.

Signed-off-by: Keir Fraser <keir.fraser@citrix.com>

1 files changed, 22 insertions, 3 deletions

diff --git a/xen/common/stop_machine.c b/xen/common/stop_machine.c
index 83f525f09b..31d5c6fff7 100644
--- a/xen/common/stop_machine.c
+++ b/xen/common/stop_machine.c
@@ -155,12 +155,31 @@ static void stopmachine_action(unsigned long cpu)
     local_irq_enable();
 }
 
-static int __init cpu_stopmachine_init(void)
+static int cpu_callback(
+    struct notifier_block *nfb, unsigned long action, void *hcpu)
 {
-    unsigned int cpu;
-    for_each_possible_cpu ( cpu )
+    unsigned int cpu = (unsigned long)hcpu;
+
+    if ( action == CPU_UP_PREPARE )
         tasklet_init(&per_cpu(stopmachine_tasklet, cpu),
                      stopmachine_action, cpu);
+
+    return NOTIFY_DONE;
+}
+
+static struct notifier_block cpu_nfb = {
+    .notifier_call = cpu_callback
+};
+
+static int __init cpu_stopmachine_init(void)
+{
+    unsigned int cpu;
+    for_each_online_cpu ( cpu )
+    {
+        void *hcpu = (void *)(long)cpu;
+        cpu_callback(&cpu_nfb, CPU_UP_PREPARE, hcpu);
+    }
+    register_cpu_notifier(&cpu_nfb);
     return 0;
 }
 __initcall(cpu_stopmachine_init);