[PATCH] kexec: x86_64: factor out apic shutdown code

Factor out the apic and smp shutdown code from machine_restart so it can be
called by in the kexec reboot path as well.

Signed-off-by: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 33 insertions, 29 deletions

diff --git a/arch/x86_64/kernel/reboot.c b/arch/x86_64/kernel/reboot.c
index be4b36f762cf..57e71dbdfd69 100644
--- a/arch/x86_64/kernel/reboot.c
+++ b/arch/x86_64/kernel/reboot.c
@@ -66,41 +66,47 @@ static int __init reboot_setup(char *str)
 
 __setup("reboot=", reboot_setup);
 
-#ifdef CONFIG_SMP
-static void smp_halt(void)
+static inline void kb_wait(void)
 {
-        int cpuid = safe_smp_processor_id(); 
-        static int first_entry = 1;
+        int i;
 
-        if (reboot_force)
-                return;
+        for (i=0; i<0x10000; i++)
+                if ((inb_p(0x64) & 0x02) == 0)
+                        break;
+}
 
-        if (first_entry) {
-                first_entry = 0;
-                smp_call_function((void *)machine_restart, NULL, 1, 0);
-        }
-                        
-        smp_stop_cpu(); 
+void machine_shutdown(void)
+{
+        /* Stop the cpus and apics */
+#ifdef CONFIG_SMP
+        int reboot_cpu_id;
 
-        /* AP calling this. Just halt */
-        if (cpuid != boot_cpu_id) { 
-                for (;;) 
-                        asm("hlt");
+        /* The boot cpu is always logical cpu 0 */
+        reboot_cpu_id = 0;
+
+        /* Make certain the cpu I'm about to reboot on is online */
+        if (!cpu_isset(reboot_cpu_id, cpu_online_map)) {
+                reboot_cpu_id = smp_processor_id();
         }
 
-        /* Wait for all other CPUs to have run smp_stop_cpu */
-        while (!cpus_empty(cpu_online_map))
-                rep_nop(); 
-}
+        /* Make certain I only run on the appropriate processor */
+        set_cpus_allowed(current, cpumask_of_cpu(reboot_cpu_id));
+
+        /* O.K Now that I'm on the appropriate processor,
+         * stop all of the others.
+         */
+        smp_send_stop();
 #endif
 
-static inline void kb_wait(void)
-{
-        int i;
+        local_irq_disable();
 
-        for (i=0; i<0x10000; i++)
-                if ((inb_p(0x64) & 0x02) == 0)
-                        break;
+#ifndef CONFIG_SMP
+        disable_local_APIC();
+#endif
+
+        disable_IO_APIC();
+
+        local_irq_enable();
 }
 
 void machine_restart(char * __unused)
@@ -109,9 +115,7 @@ void machine_restart(char * __unused)
 
         printk("machine restart\n");
 
-#ifdef CONFIG_SMP
-        smp_halt(); 
-#endif
+        machine_shutdown();
 
         if (!reboot_force) {
                 local_irq_disable();