[S390] rework smp code

Define struct pcpu and merge some of the NR_CPUS arrays into it, including
__cpu_logical_map, current_set and smp_cpu_state. Split smp related
functions to those operating on physical cpus and the functions operating
on a logical cpu number. Make the functions for physical cpus use a
pointer to a struct pcpu. This hides the knowledge about cpu addresses in
smp.c, entry[64].S and swsusp_asm64.S, thus remove the sigp.h header.

The PSW restart mechanism is used to start secondary cpus, calling a
function on an online cpu, calling a function on the ipl cpu, and for
the nmi signal. Replace the different assembler functions with a
single function restart_int_handler. The new entry point calls a function
whose pointer is stored in the lowcore of the target cpu and it can wait
for the source cpu to stop. This covers all existing use cases.

Overall the code is now simpler and there are ~380 lines less code.

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 11 insertions, 10 deletions

diff --git a/arch/s390/kernel/ipl.c b/arch/s390/kernel/ipl.c
index affa8e68124a..e5a72a2b0c56 100644
--- a/arch/s390/kernel/ipl.c
+++ b/arch/s390/kernel/ipl.c
@@ -2,7 +2,7 @@
  *  arch/s390/kernel/ipl.c
  *    ipl/reipl/dump support for Linux on s390.
  *
- *    Copyright IBM Corp. 2005,2007
+ *    Copyright IBM Corp. 2005,2012
  *    Author(s): Michael Holzheu <holzheu@de.ibm.com>
  *		 Heiko Carstens <heiko.carstens@de.ibm.com>
  *		 Volker Sameske <sameske@de.ibm.com>
@@ -25,7 +25,6 @@
 #include <asm/ebcdic.h>
 #include <asm/reset.h>
 #include <asm/sclp.h>
-#include <asm/sigp.h>
 #include <asm/checksum.h>
 #include "entry.h"
 
@@ -571,7 +570,7 @@ static void __ipl_run(void *unused)
 
 static void ipl_run(struct shutdown_trigger *trigger)
 {
-	smp_switch_to_ipl_cpu(__ipl_run, NULL);
+	smp_call_ipl_cpu(__ipl_run, NULL);
 }
 
 static int __init ipl_init(void)
@@ -1101,7 +1100,7 @@ static void __reipl_run(void *unused)
 
 static void reipl_run(struct shutdown_trigger *trigger)
 {
-	smp_switch_to_ipl_cpu(__reipl_run, NULL);
+	smp_call_ipl_cpu(__reipl_run, NULL);
 }
 
 static void reipl_block_ccw_init(struct ipl_parameter_block *ipb)
@@ -1421,7 +1420,7 @@ static void dump_run(struct shutdown_trigger *trigger)
 	if (dump_method == DUMP_METHOD_NONE)
 		return;
 	smp_send_stop();
-	smp_switch_to_ipl_cpu(__dump_run, NULL);
+	smp_call_ipl_cpu(__dump_run, NULL);
 }
 
 static int __init dump_ccw_init(void)
@@ -1623,9 +1622,7 @@ static void stop_run(struct shutdown_trigger *trigger)
 	if (strcmp(trigger->name, ON_PANIC_STR) == 0 ||
 	    strcmp(trigger->name, ON_RESTART_STR) == 0)
 		disabled_wait((unsigned long) __builtin_return_address(0));
-	while (sigp(smp_processor_id(), sigp_stop) == sigp_busy)
-		cpu_relax();
-	for (;;);
+	smp_stop_cpu();
 }
 
 static struct shutdown_action stop_action = {SHUTDOWN_ACTION_STOP_STR,
@@ -1738,9 +1735,8 @@ static ssize_t on_restart_store(struct kobject *kobj,
 static struct kobj_attribute on_restart_attr =
 	__ATTR(on_restart, 0644, on_restart_show, on_restart_store);
 
-void do_restart(void)
+static void __do_restart(void *ignore)
 {
-	smp_restart_with_online_cpu();
 	smp_send_stop();
 #ifdef CONFIG_CRASH_DUMP
 	crash_kexec(NULL);
@@ -1749,6 +1745,11 @@ void do_restart(void)
 	stop_run(&on_restart_trigger);
 }
 
+void do_restart(void)
+{
+	smp_call_online_cpu(__do_restart, NULL);
+}
+
 /* on halt */
 
 static struct shutdown_trigger on_halt_trigger = {ON_HALT_STR, &stop_action};