x86: provide __smp_call_function

This function is used in smp_send_stop(). It's like
smp_call_function_mask, but always go to all online cpus,
and does not take any locks.

It is added to x86_64, but will soon be unified in a common file

Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/kernel/smp_64.c b/arch/x86/kernel/smp_64.c
index 1d8b863fa357add5bcd2725fadc0f1e7f10bb63b..aa2edb7f3a5147de61bf9ca0dad6719d90609908 100644 (file)
--- a/arch/x86/kernel/smp_64.c
+++ b/arch/x86/kernel/smp_64.c
@@ -322,6 +322,38 @@ void unlock_ipi_call_lock(void)
        spin_unlock_irq(&call_lock);
 }
 
+static void __smp_call_function(void (*func) (void *info), void *info,
+                               int nonatomic, int wait)
+{
+       struct call_data_struct data;
+       int cpus = num_online_cpus() - 1;
+
+       if (!cpus)
+               return;
+
+       data.func = func;
+       data.info = info;
+       atomic_set(&data.started, 0);
+       data.wait = wait;
+       if (wait)
+               atomic_set(&data.finished, 0);
+
+       call_data = &data;
+       mb();
+
+       /* Send a message to all other CPUs and wait for them to respond */
+       send_IPI_allbutself(CALL_FUNCTION_VECTOR);
+
+       /* Wait for response */
+       while (atomic_read(&data.started) != cpus)
+               cpu_relax();
+
+       if (wait)
+               while (atomic_read(&data.finished) != cpus)
+                       cpu_relax();
+}
+
+
 /*
  * this function sends a 'generic call function' IPI to all other CPU
  * of the system defined in the mask.
@@ -424,7 +456,7 @@ void smp_send_stop(void)
        /* Don't deadlock on the call lock in panic */
        nolock = !spin_trylock(&call_lock);
        local_irq_save(flags);
-       __smp_call_function_mask(cpu_online_map, stop_this_cpu, NULL, 0);
+       __smp_call_function(stop_this_cpu, NULL, 0, 0);
        if (!nolock)
                spin_unlock(&call_lock);
        disable_local_APIC();