[PATCH] for_each_possible_cpu: s390

for_each_cpu() actually iterates across all possible CPUs.  We've had mistakes
in the past where people were using for_each_cpu() where they should have been
iterating across only online or present CPUs.  This is inefficient and
possibly buggy.

We're renaming for_each_cpu() to for_each_possible_cpu() to avoid this in the
future.

This patch replaces for_each_cpu with for_each_possible_cpu.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/s390/kernel/smp.c

@@ -801,7 +801,7 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
          */
 	print_cpu_info(&S390_lowcore.cpu_data);
 
-        for_each_cpu(i) {
+        for_each_possible_cpu(i) {
 		lowcore_ptr[i] = (struct _lowcore *)
 			__get_free_pages(GFP_KERNEL|GFP_DMA, 
 					sizeof(void*) == 8 ? 1 : 0);
@@ -831,7 +831,7 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
 #endif
 	set_prefix((u32)(unsigned long) lowcore_ptr[smp_processor_id()]);
 
-	for_each_cpu(cpu)
+	for_each_possible_cpu(cpu)
 		if (cpu != smp_processor_id())
 			smp_create_idle(cpu);
 }
@@ -868,7 +868,7 @@ static int __init topology_init(void)
 	int cpu;
 	int ret;
 
-	for_each_cpu(cpu) {
+	for_each_possible_cpu(cpu) {
 		ret = register_cpu(&per_cpu(cpu_devices, cpu), cpu, NULL);
 		if (ret)
 			printk(KERN_WARNING "topology_init: register_cpu %d "

include/asm-s390/percpu.h

@@ -46,7 +46,7 @@ extern unsigned long __per_cpu_offset[NR_CPUS];
 #define percpu_modcopy(pcpudst, src, size)			\
 do {								\
 	unsigned int __i;					\
-	for_each_cpu(__i)					\
+	for_each_possible_cpu(__i)				\
 		memcpy((pcpudst)+__per_cpu_offset[__i],		\
 		       (src), (size));				\
 } while (0)