s390/hibernate: add early resume function

Some functions that do arch specific resume actions are called
directly from swsusp_asm64.S . Before we add another function call
provide a generic s390_early_resume function which can be used
for this purpose.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/include/asm/cio.h

@@ -296,6 +296,7 @@ static inline int ccw_dev_id_is_equal(struct ccw_dev_id *dev_id1,
 	return 0;
 }
 
+void channel_subsystem_reinit(void);
 extern void css_schedule_reprobe(void);
 
 extern void reipl_ccw_dev(struct ccw_dev_id *id);

arch/s390/kernel/suspend.c

@@ -10,6 +10,8 @@
 #include <linux/suspend.h>
 #include <linux/mm.h>
 #include <asm/ctl_reg.h>
+#include <asm/ipl.h>
+#include <asm/cio.h>
 
 /*
  * References to section boundaries
@@ -211,3 +213,10 @@ void restore_processor_state(void)
 	__ctl_set_bit(0,28);
 	local_mcck_enable();
 }
+
+/* Called at the end of swsusp_arch_resume */
+void s390_early_resume(void)
+{
+	lgr_info_log();
+	channel_subsystem_reinit();
+}

arch/s390/kernel/swsusp_asm64.S

@@ -281,11 +281,8 @@ restore_registers:
 	lghi	%r2,0
 	brasl	%r14,arch_set_page_states
 
-	/* Log potential guest relocation */
-	brasl	%r14,lgr_info_log
-
-	/* Reinitialize the channel subsystem */
-	brasl	%r14,channel_subsystem_reinit
+	/* Call arch specific early resume code */
+	brasl	%r14,s390_early_resume
 
 	/* Return 0 */
 	lmg	%r6,%r15,STACK_FRAME_OVERHEAD + __SF_GPRS(%r15)

drivers/s390/cio/css.h

@@ -130,8 +130,6 @@ struct channel_subsystem {
 
 extern struct channel_subsystem *channel_subsystems[];
 
-void channel_subsystem_reinit(void);
-
 /* Helper functions to build lists for the slow path. */
 void css_schedule_eval(struct subchannel_id schid);
 void css_schedule_eval_all(void);