x86: call machine_shutdown and stop all CPUs in native_machine_halt

Impact: really halt all CPUs on halt

Function machine_halt (resp. native_machine_halt) is empty for x86
architectures. When command 'halt -f' is invoked, the message "System
halted." is displayed but this is not really true because all CPUs are
still running.

There are also similar inconsistencies for other arches (some uses
power-off for halt or forever-loop with IRQs enabled/disabled).

IMO there should be used the same approach for all architectures OR
what does the message "System halted" really mean?

This patch fixes it for x86.

Signed-off-by: Ivan Vecera <ivecera@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

5 files changed, 24 insertions, 13 deletions

diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index 3b1510b4fc57..25caa0738af5 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -193,6 +193,7 @@ extern u8 setup_APIC_eilvt_ibs(u8 vector, u8 msg_type, u8 mask);
 static inline void lapic_shutdown(void) { }
 #define local_apic_timer_c2_ok          1
 static inline void init_apic_mappings(void) { }
+static inline void disable_local_APIC(void) { }
 
 #endif /* !CONFIG_X86_LOCAL_APIC */
 
diff --git a/arch/x86/include/asm/system.h b/arch/x86/include/asm/system.h
index 2ed3f0f44ff7..07c3e4048991 100644
--- a/arch/x86/include/asm/system.h
+++ b/arch/x86/include/asm/system.h
@@ -314,6 +314,8 @@ extern void free_init_pages(char *what, unsigned long begin, unsigned long end);
 
 void default_idle(void);
 
+void stop_this_cpu(void *dummy);
+
 /*
  * Force strict CPU ordering.
  * And yes, this is required on UP too when we're talking
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index c622772744d8..a4da7c4b3129 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -8,6 +8,7 @@
 #include <linux/pm.h>
 #include <linux/clockchips.h>
 #include <asm/system.h>
+#include <asm/apic.h>
 
 unsigned long idle_halt;
 EXPORT_SYMBOL(idle_halt);
@@ -122,6 +123,21 @@ void default_idle(void)
 EXPORT_SYMBOL(default_idle);
 #endif
 
+void stop_this_cpu(void *dummy)
+{
+        local_irq_disable();
+        /*
+         * Remove this CPU:
+         */
+        cpu_clear(smp_processor_id(), cpu_online_map);
+        disable_local_APIC();
+
+        for (;;) {
+                if (hlt_works(smp_processor_id()))
+                        halt();
+        }
+}
+
 static void do_nothing(void *unused)
 {
 }
diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
index 724adfc63cb9..34f8d37ae3c5 100644
--- a/arch/x86/kernel/reboot.c
+++ b/arch/x86/kernel/reboot.c
@@ -461,6 +461,11 @@ static void native_machine_restart(char *__unused)
 
 static void native_machine_halt(void)
 {
+        /* stop other cpus and apics */
+        machine_shutdown();
+
+        /* stop this cpu */
+        stop_this_cpu(NULL);
 }
 
 static void native_machine_power_off(void)
diff --git a/arch/x86/kernel/smp.c b/arch/x86/kernel/smp.c
index 18f9b19f5f8f..3f92b134ab90 100644
--- a/arch/x86/kernel/smp.c
+++ b/arch/x86/kernel/smp.c
@@ -140,19 +140,6 @@ void native_send_call_func_ipi(cpumask_t mask)
                 send_IPI_mask(mask, CALL_FUNCTION_VECTOR);
 }
 
-static void stop_this_cpu(void *dummy)
-{
-        local_irq_disable();
-        /*
-         * Remove this CPU:
-         */
-        cpu_clear(smp_processor_id(), cpu_online_map);
-        disable_local_APIC();
-        if (hlt_works(smp_processor_id()))
-                for (;;) halt();
-        for (;;);
-}
-
 /*
  * this function calls the 'stop' function on all other CPUs in the system.
  */