[S390] topology: get rid of ifdefs

Remove all ifdefs from topology code and also only compile it for the
CONFIG_SCHED_BOOK case. The new code selects SCHED_MC if SCHED_BOOK is
selected. SCHED_MC without SCHED_BOOK is not possible anymore.
Furthermore various sysfs attributes are not available anymore for the
!SCHED_BOOK case. In particular all attributes that correspond to
CPU polarization.
But since all real world kernels have SCHED_BOOK selected anyway this
doesn't matter too much.

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

arch/s390/Kconfig

@@ -191,18 +191,13 @@ config HOTPLUG_CPU
 	  Say N if you want to disable CPU hotplug.
 
 config SCHED_MC
-	def_bool y
-	prompt "Multi-core scheduler support"
-	depends on SMP
-	help
-	  Multi-core scheduler support improves the CPU scheduler's decision
-	  making when dealing with multi-core CPU chips at a cost of slightly
-	  increased overhead in some places.
+	def_bool n
 
 config SCHED_BOOK
 	def_bool y
 	prompt "Book scheduler support"
-	depends on SMP && SCHED_MC
+	depends on SMP
+	select SCHED_MC
 	help
 	  Book scheduler support improves the CPU scheduler's decision making
 	  when dealing with machines that have several books.

arch/s390/include/asm/smp.h

@@ -23,7 +23,6 @@ extern void __cpu_die (unsigned int cpu);
 extern int __cpu_up (unsigned int cpu);
 
 extern struct mutex smp_cpu_state_mutex;
-extern int smp_cpu_polarization[];
 
 extern void arch_send_call_function_single_ipi(int cpu);
 extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);

arch/s390/include/asm/topology.h

@@ -4,6 +4,10 @@
 #include <linux/cpumask.h>
 #include <asm/sysinfo.h>
 
+struct cpu;
+
+#ifdef CONFIG_SCHED_BOOK
+
 extern unsigned char cpu_core_id[NR_CPUS];
 extern cpumask_t cpu_core_map[NR_CPUS];
 
@@ -16,8 +20,6 @@ static inline const struct cpumask *cpu_coregroup_mask(int cpu)
 #define topology_core_cpumask(cpu)	(&cpu_core_map[cpu])
 #define mc_capable()			(1)
 
-#ifdef CONFIG_SCHED_BOOK
-
 extern unsigned char cpu_book_id[NR_CPUS];
 extern cpumask_t cpu_book_map[NR_CPUS];
 
@@ -29,19 +31,43 @@ static inline const struct cpumask *cpu_book_mask(int cpu)
 #define topology_book_id(cpu)		(cpu_book_id[cpu])
 #define topology_book_cpumask(cpu)	(&cpu_book_map[cpu])
 
-#endif /* CONFIG_SCHED_BOOK */
-
+int topology_cpu_init(struct cpu *);
 int topology_set_cpu_management(int fc);
 void topology_schedule_update(void);
 void store_topology(struct sysinfo_15_1_x *info);
 
-#define POLARIZATION_UNKNWN	(-1)
+#else /* CONFIG_SCHED_BOOK */
+
+static inline void topology_schedule_update(void) { }
+static inline int topology_cpu_init(struct cpu *cpu) { return 0; }
+
+#endif /* CONFIG_SCHED_BOOK */
+
+#define POLARIZATION_UNKNOWN	(-1)
 #define POLARIZATION_HRZ	(0)
 #define POLARIZATION_VL		(1)
 #define POLARIZATION_VM		(2)
 #define POLARIZATION_VH		(3)
 
-#ifdef CONFIG_SMP
+extern int cpu_polarization[];
+
+static inline void cpu_set_polarization(int cpu, int val)
+{
+#ifdef CONFIG_SCHED_BOOK
+	cpu_polarization[cpu] = val;
+#endif
+}
+
+static inline int cpu_read_polarization(int cpu)
+{
+#ifdef CONFIG_SCHED_BOOK
+	return cpu_polarization[cpu];
+#else
+	return POLARIZATION_HRZ;
+#endif
+}
+
+#ifdef CONFIG_SCHED_BOOK
 void s390_init_cpu_topology(void);
 #else
 static inline void s390_init_cpu_topology(void)

arch/s390/kernel/Makefile

@@ -32,7 +32,8 @@ extra-y				+= head.o init_task.o vmlinux.lds
 extra-y				+= $(if $(CONFIG_64BIT),head64.o,head31.o)
 
 obj-$(CONFIG_MODULES)		+= s390_ksyms.o module.o
-obj-$(CONFIG_SMP)		+= smp.o topology.o
+obj-$(CONFIG_SMP)		+= smp.o
+obj-$(CONFIG_SCHED_BOOK)	+= topology.o
 obj-$(CONFIG_SMP)		+= $(if $(CONFIG_64BIT),switch_cpu64.o, \
 							switch_cpu.o)
 obj-$(CONFIG_HIBERNATION)	+= suspend.o swsusp_asm64.o

arch/s390/kernel/smp.c

@@ -69,9 +69,7 @@ enum s390_cpu_state {
 };
 
 DEFINE_MUTEX(smp_cpu_state_mutex);
-int smp_cpu_polarization[NR_CPUS];
 static int smp_cpu_state[NR_CPUS];
-static int cpu_management;
 
 static DEFINE_PER_CPU(struct cpu, cpu_devices);
 
@@ -369,7 +367,7 @@ static int smp_rescan_cpus_sigp(cpumask_t avail)
 		if (cpu_known(cpu_id))
 			continue;
 		__cpu_logical_map[logical_cpu] = cpu_id;
-		smp_cpu_polarization[logical_cpu] = POLARIZATION_UNKNWN;
+		cpu_set_polarization(logical_cpu, POLARIZATION_UNKNOWN);
 		if (!cpu_stopped(logical_cpu))
 			continue;
 		set_cpu_present(logical_cpu, true);
@@ -403,7 +401,7 @@ static int smp_rescan_cpus_sclp(cpumask_t avail)
 		if (cpu_known(cpu_id))
 			continue;
 		__cpu_logical_map[logical_cpu] = cpu_id;
-		smp_cpu_polarization[logical_cpu] = POLARIZATION_UNKNWN;
+		cpu_set_polarization(logical_cpu, POLARIZATION_UNKNOWN);
 		set_cpu_present(logical_cpu, true);
 		if (cpu >= info->configured)
 			smp_cpu_state[logical_cpu] = CPU_STATE_STANDBY;
@@ -806,7 +804,7 @@ void __init smp_prepare_boot_cpu(void)
 	S390_lowcore.percpu_offset = __per_cpu_offset[0];
 	current_set[0] = current;
 	smp_cpu_state[0] = CPU_STATE_CONFIGURED;
-	smp_cpu_polarization[0] = POLARIZATION_UNKNWN;
+	cpu_set_polarization(0, POLARIZATION_UNKNOWN);
 }
 
 void __init smp_cpus_done(unsigned int max_cpus)
@@ -868,7 +866,7 @@ static ssize_t cpu_configure_store(struct sys_device *dev,
 			rc = sclp_cpu_deconfigure(__cpu_logical_map[cpu]);
 			if (!rc) {
 				smp_cpu_state[cpu] = CPU_STATE_STANDBY;
-				smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
+				cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
 			}
 		}
 		break;
@@ -877,7 +875,7 @@ static ssize_t cpu_configure_store(struct sys_device *dev,
 			rc = sclp_cpu_configure(__cpu_logical_map[cpu]);
 			if (!rc) {
 				smp_cpu_state[cpu] = CPU_STATE_CONFIGURED;
-				smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
+				cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
 			}
 		}
 		break;
@@ -892,49 +890,18 @@ static ssize_t cpu_configure_store(struct sys_device *dev,
 static SYSDEV_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store);
 #endif /* CONFIG_HOTPLUG_CPU */
 
-static ssize_t cpu_polarization_show(struct sys_device *dev,
-				     struct sysdev_attribute *attr, char *buf)
-{
-	int cpu = dev->id;
-	ssize_t count;
-
-	mutex_lock(&smp_cpu_state_mutex);
-	switch (smp_cpu_polarization[cpu]) {
-	case POLARIZATION_HRZ:
-		count = sprintf(buf, "horizontal\n");
-		break;
-	case POLARIZATION_VL:
-		count = sprintf(buf, "vertical:low\n");
-		break;
-	case POLARIZATION_VM:
-		count = sprintf(buf, "vertical:medium\n");
-		break;
-	case POLARIZATION_VH:
-		count = sprintf(buf, "vertical:high\n");
-		break;
-	default:
-		count = sprintf(buf, "unknown\n");
-		break;
-	}
-	mutex_unlock(&smp_cpu_state_mutex);
-	return count;
-}
-static SYSDEV_ATTR(polarization, 0444, cpu_polarization_show, NULL);
-
 static ssize_t show_cpu_address(struct sys_device *dev,
 				struct sysdev_attribute *attr, char *buf)
 {
 	return sprintf(buf, "%d\n", __cpu_logical_map[dev->id]);
 }
 static SYSDEV_ATTR(address, 0444, show_cpu_address, NULL);
 
-
 static struct attribute *cpu_common_attrs[] = {
 #ifdef CONFIG_HOTPLUG_CPU
 	&attr_configure.attr,
 #endif
 	&attr_address.attr,
-	&attr_polarization.attr,
 	NULL,
 };
 
@@ -1055,11 +1022,20 @@ static int __devinit smp_add_present_cpu(int cpu)
 	rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
 	if (rc)
 		goto out_cpu;
-	if (!cpu_online(cpu))
-		goto out;
-	rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
-	if (!rc)
-		return 0;
+	if (cpu_online(cpu)) {
+		rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
+		if (rc)
+			goto out_online;
+	}
+	rc = topology_cpu_init(c);
+	if (rc)
+		goto out_topology;
+	return 0;
+
+out_topology:
+	if (cpu_online(cpu))
+		sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
+out_online:
 	sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
 out_cpu:
 #ifdef CONFIG_HOTPLUG_CPU
@@ -1111,66 +1087,21 @@ static ssize_t __ref rescan_store(struct sysdev_class *class,
 static SYSDEV_CLASS_ATTR(rescan, 0200, NULL, rescan_store);
 #endif /* CONFIG_HOTPLUG_CPU */
 
-static ssize_t dispatching_show(struct sysdev_class *class,
-				struct sysdev_class_attribute *attr,
-				char *buf)
+static int __init s390_smp_init(void)
 {
-	ssize_t count;
-
-	mutex_lock(&smp_cpu_state_mutex);
-	count = sprintf(buf, "%d\n", cpu_management);
-	mutex_unlock(&smp_cpu_state_mutex);
-	return count;
-}
-
-static ssize_t dispatching_store(struct sysdev_class *dev,
-				 struct sysdev_class_attribute *attr,
-				 const char *buf,
-				 size_t count)
-{
-	int val, rc;
-	char delim;
-
-	if (sscanf(buf, "%d %c", &val, &delim) != 1)
-		return -EINVAL;
-	if (val != 0 && val != 1)
-		return -EINVAL;
-	rc = 0;
-	get_online_cpus();
-	mutex_lock(&smp_cpu_state_mutex);
-	if (cpu_management == val)
-		goto out;
-	rc = topology_set_cpu_management(val);
-	if (!rc)
-		cpu_management = val;
-out:
-	mutex_unlock(&smp_cpu_state_mutex);
-	put_online_cpus();
-	return rc ? rc : count;
-}
-static SYSDEV_CLASS_ATTR(dispatching, 0644, dispatching_show,
-			 dispatching_store);
-
-static int __init topology_init(void)
-{
-	int cpu;
-	int rc;
+	int cpu, rc;
 
 	register_cpu_notifier(&smp_cpu_nb);
-
 #ifdef CONFIG_HOTPLUG_CPU
 	rc = sysdev_class_create_file(&cpu_sysdev_class, &attr_rescan);
 	if (rc)
 		return rc;
 #endif
-	rc = sysdev_class_create_file(&cpu_sysdev_class, &attr_dispatching);
-	if (rc)
-		return rc;
 	for_each_present_cpu(cpu) {
 		rc = smp_add_present_cpu(cpu);
 		if (rc)
 			return rc;
 	}
 	return 0;
 }
-subsys_initcall(topology_init);
+subsys_initcall(s390_smp_init);