x86 / hibernate: Use hlt_play_dead() when resuming from hibernation

[cascardo/linux.git] / arch / x86 / power / cpu.c

diff --git a/arch/x86/power/cpu.c b/arch/x86/power/cpu.c
index d5f6499..b12c26e 100644 (file)
--- a/arch/x86/power/cpu.c
+++ b/arch/x86/power/cpu.c
@@ -12,6 +12,7 @@
 #include <linux/export.h>
 #include <linux/smp.h>
 #include <linux/perf_event.h>
+#include <linux/tboot.h>
 
 #include <asm/pgtable.h>
 #include <asm/proto.h>
@@ -266,6 +267,35 @@ void notrace restore_processor_state(void)
 EXPORT_SYMBOL(restore_processor_state);
 #endif
 
+#if defined(CONFIG_HIBERNATION) && defined(CONFIG_HOTPLUG_CPU)
+static void resume_play_dead(void)
+{
+       play_dead_common();
+       tboot_shutdown(TB_SHUTDOWN_WFS);
+       hlt_play_dead();
+}
+
+int hibernate_resume_nonboot_cpu_disable(void)
+{
+       void (*play_dead)(void) = smp_ops.play_dead;
+       int ret;
+
+       /*
+        * Ensure that MONITOR/MWAIT will not be used in the "play dead" loop
+        * during hibernate image restoration, because it is likely that the
+        * monitored address will be actually written to at that time and then
+        * the "dead" CPU will attempt to execute instructions again, but the
+        * address in its instruction pointer may not be possible to resolve
+        * any more at that point (the page tables used by it previously may
+        * have been overwritten by hibernate image data).
+        */
+       smp_ops.play_dead = resume_play_dead;
+       ret = disable_nonboot_cpus();
+       smp_ops.play_dead = play_dead;
+       return ret;
+}
+#endif
+
 /*
  * When bsp_check() is called in hibernate and suspend, cpu hotplug
  * is disabled already. So it's unnessary to handle race condition between