1 files changed, 438 insertions, 197 deletions

diff --git a/arch/s390/kernel/topology.c b/arch/s390/kernel/topology.c
index 4b2e3e317004..1913a5566ac2 100644
--- a/arch/s390/kernel/topology.c
+++ b/arch/s390/kernel/topology.c
@@ -1,92 +1,155 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  *    Copyright IBM Corp. 2007, 2011
- *    Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
  */
 
-#define KMSG_COMPONENT "cpu"
-#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+#define pr_fmt(fmt) "cpu: " fmt
 
+#include <linux/cpufeature.h>
 #include <linux/workqueue.h>
-#include <linux/bootmem.h>
+#include <linux/memblock.h>
+#include <linux/uaccess.h>
+#include <linux/sysctl.h>
 #include <linux/cpuset.h>
 #include <linux/device.h>
 #include <linux/export.h>
 #include <linux/kernel.h>
 #include <linux/sched.h>
-#include <linux/init.h>
+#include <linux/sched/topology.h>
 #include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/slab.h>
 #include <linux/cpu.h>
 #include <linux/smp.h>
 #include <linux/mm.h>
+#include <linux/nodemask.h>
+#include <linux/node.h>
+#include <asm/hiperdispatch.h>
 #include <asm/sysinfo.h>
+#include <asm/asm.h>
 
 #define PTF_HORIZONTAL	(0UL)
 #define PTF_VERTICAL	(1UL)
 #define PTF_CHECK	(2UL)
 
+enum {
+	TOPOLOGY_MODE_HW,
+	TOPOLOGY_MODE_SINGLE,
+	TOPOLOGY_MODE_PACKAGE,
+	TOPOLOGY_MODE_UNINITIALIZED
+};
+
 struct mask_info {
 	struct mask_info *next;
 	unsigned char id;
 	cpumask_t mask;
 };
 
+static int topology_mode = TOPOLOGY_MODE_UNINITIALIZED;
 static void set_topology_timer(void);
 static void topology_work_fn(struct work_struct *work);
 static struct sysinfo_15_1_x *tl_info;
+static int cpu_management;
 
-static int topology_enabled = 1;
 static DECLARE_WORK(topology_work, topology_work_fn);
 
-/* topology_lock protects the socket and book linked lists */
-static DEFINE_SPINLOCK(topology_lock);
+/*
+ * Socket/Book linked lists and cpu_topology updates are
+ * protected by "sched_domains_mutex".
+ */
 static struct mask_info socket_info;
 static struct mask_info book_info;
+static struct mask_info drawer_info;
 
 struct cpu_topology_s390 cpu_topology[NR_CPUS];
 EXPORT_SYMBOL_GPL(cpu_topology);
 
-static cpumask_t cpu_group_map(struct mask_info *info, unsigned int cpu)
+static void cpu_group_map(cpumask_t *dst, struct mask_info *info, unsigned int cpu)
 {
-	cpumask_t mask;
+	static cpumask_t mask;
+
+	cpumask_clear(&mask);
+	if (!cpumask_test_cpu(cpu, &cpu_setup_mask))
+		goto out;
+	cpumask_set_cpu(cpu, &mask);
+	switch (topology_mode) {
+	case TOPOLOGY_MODE_HW:
+		while (info) {
+			if (cpumask_test_cpu(cpu, &info->mask)) {
+				cpumask_copy(&mask, &info->mask);
+				break;
+			}
+			info = info->next;
+		}
+		break;
+	case TOPOLOGY_MODE_PACKAGE:
+		cpumask_copy(&mask, cpu_present_mask);
+		break;
+	default:
+		fallthrough;
+	case TOPOLOGY_MODE_SINGLE:
+		break;
+	}
+	cpumask_and(&mask, &mask, &cpu_setup_mask);
+out:
+	cpumask_copy(dst, &mask);
+}
+
+static void cpu_thread_map(cpumask_t *dst, unsigned int cpu)
+{
+	static cpumask_t mask;
+	unsigned int max_cpu;
 
-	cpumask_copy(&mask, cpumask_of(cpu));
-	if (!topology_enabled || !MACHINE_HAS_TOPOLOGY)
-		return mask;
-	for (; info; info = info->next) {
-		if (cpumask_test_cpu(cpu, &info->mask))
-			return info->mask;
+	cpumask_clear(&mask);
+	if (!cpumask_test_cpu(cpu, &cpu_setup_mask))
+		goto out;
+	cpumask_set_cpu(cpu, &mask);
+	if (topology_mode != TOPOLOGY_MODE_HW)
+		goto out;
+	cpu -= cpu % (smp_cpu_mtid + 1);
+	max_cpu = min(cpu + smp_cpu_mtid, nr_cpu_ids - 1);
+	for (; cpu <= max_cpu; cpu++) {
+		if (cpumask_test_cpu(cpu, &cpu_setup_mask))
+			cpumask_set_cpu(cpu, &mask);
 	}
-	return mask;
+out:
+	cpumask_copy(dst, &mask);
 }
 
-static struct mask_info *add_cpus_to_mask(struct topology_cpu *tl_cpu,
-					  struct mask_info *book,
-					  struct mask_info *socket,
-					  int one_socket_per_cpu)
+#define TOPOLOGY_CORE_BITS	64
+
+static void add_cpus_to_mask(struct topology_core *tl_core,
+			     struct mask_info *drawer,
+			     struct mask_info *book,
+			     struct mask_info *socket)
 {
-	unsigned int cpu;
+	struct cpu_topology_s390 *topo;
+	unsigned int core;
 
-	for_each_set_bit(cpu, &tl_cpu->mask[0], TOPOLOGY_CPU_BITS) {
-		unsigned int rcpu;
-		int lcpu;
+	for_each_set_bit(core, &tl_core->mask, TOPOLOGY_CORE_BITS) {
+		unsigned int max_cpu, rcore;
+		int cpu;
 
-		rcpu = TOPOLOGY_CPU_BITS - 1 - cpu + tl_cpu->origin;
-		lcpu = smp_find_processor_id(rcpu);
-		if (lcpu < 0)
+		rcore = TOPOLOGY_CORE_BITS - 1 - core + tl_core->origin;
+		cpu = smp_find_processor_id(rcore << smp_cpu_mt_shift);
+		if (cpu < 0)
 			continue;
-		cpumask_set_cpu(lcpu, &book->mask);
-		cpu_topology[lcpu].book_id = book->id;
-		cpumask_set_cpu(lcpu, &socket->mask);
-		cpu_topology[lcpu].core_id = rcpu;
-		if (one_socket_per_cpu) {
-			cpu_topology[lcpu].socket_id = rcpu;
-			socket = socket->next;
-		} else {
-			cpu_topology[lcpu].socket_id = socket->id;
+		max_cpu = min(cpu + smp_cpu_mtid, nr_cpu_ids - 1);
+		for (; cpu <= max_cpu; cpu++) {
+			topo = &cpu_topology[cpu];
+			topo->drawer_id = drawer->id;
+			topo->book_id = book->id;
+			topo->socket_id = socket->id;
+			topo->core_id = rcore;
+			topo->thread_id = cpu;
+			topo->dedicated = tl_core->d;
+			cpumask_set_cpu(cpu, &drawer->mask);
+			cpumask_set_cpu(cpu, &book->mask);
+			cpumask_set_cpu(cpu, &socket->mask);
+			smp_cpu_set_polarization(cpu, tl_core->pp);
+			smp_cpu_set_capacity(cpu, CPU_CAPACITY_HIGH);
 		}
-		smp_cpu_set_polarization(lcpu, tl_cpu->pp);
 	}
-	return socket;
 }
 
 static void clear_masks(void)
@@ -103,25 +166,36 @@ static void clear_masks(void)
 		cpumask_clear(&info->mask);
 		info = info->next;
 	}
+	info = &drawer_info;
+	while (info) {
+		cpumask_clear(&info->mask);
+		info = info->next;
+	}
 }
 
 static union topology_entry *next_tle(union topology_entry *tle)
 {
 	if (!tle->nl)
-		return (union topology_entry *)((struct topology_cpu *)tle + 1);
+		return (union topology_entry *)((struct topology_core *)tle + 1);
 	return (union topology_entry *)((struct topology_container *)tle + 1);
 }
 
-static void __tl_to_masks_generic(struct sysinfo_15_1_x *info)
+static void tl_to_masks(struct sysinfo_15_1_x *info)
 {
 	struct mask_info *socket = &socket_info;
 	struct mask_info *book = &book_info;
+	struct mask_info *drawer = &drawer_info;
 	union topology_entry *tle, *end;
 
+	clear_masks();
 	tle = info->tle;
 	end = (union topology_entry *)((unsigned long)info + info->length);
 	while (tle < end) {
 		switch (tle->nl) {
+		case 3:
+			drawer = drawer->next;
+			drawer->id = tle->container.id;
+			break;
 		case 2:
 			book = book->next;
 			book->id = tle->container.id;
@@ -131,32 +205,7 @@ static void __tl_to_masks_generic(struct sysinfo_15_1_x *info)
 			socket->id = tle->container.id;
 			break;
 		case 0:
-			add_cpus_to_mask(&tle->cpu, book, socket, 0);
-			break;
-		default:
-			clear_masks();
-			return;
-		}
-		tle = next_tle(tle);
-	}
-}
-
-static void __tl_to_masks_z10(struct sysinfo_15_1_x *info)
-{
-	struct mask_info *socket = &socket_info;
-	struct mask_info *book = &book_info;
-	union topology_entry *tle, *end;
-
-	tle = info->tle;
-	end = (union topology_entry *)((unsigned long)info + info->length);
-	while (tle < end) {
-		switch (tle->nl) {
-		case 1:
-			book = book->next;
-			book->id = tle->container.id;
-			break;
-		case 0:
-			socket = add_cpus_to_mask(&tle->cpu, book, socket, 1);
+			add_cpus_to_mask(&tle->cpu, drawer, book, socket);
 			break;
 		default:
 			clear_masks();
@@ -166,52 +215,32 @@ static void __tl_to_masks_z10(struct sysinfo_15_1_x *info)
 	}
 }
 
-static void tl_to_masks(struct sysinfo_15_1_x *info)
-{
-	struct cpuid cpu_id;
-
-	spin_lock_irq(&topology_lock);
-	get_cpu_id(&cpu_id);
-	clear_masks();
-	switch (cpu_id.machine) {
-	case 0x2097:
-	case 0x2098:
-		__tl_to_masks_z10(info);
-		break;
-	default:
-		__tl_to_masks_generic(info);
-	}
-	spin_unlock_irq(&topology_lock);
-}
-
 static void topology_update_polarization_simple(void)
 {
 	int cpu;
 
-	mutex_lock(&smp_cpu_state_mutex);
 	for_each_possible_cpu(cpu)
 		smp_cpu_set_polarization(cpu, POLARIZATION_HRZ);
-	mutex_unlock(&smp_cpu_state_mutex);
 }
 
 static int ptf(unsigned long fc)
 {
-	int rc;
+	int cc;
 
 	asm volatile(
-		"	.insn	rre,0xb9a20000,%1,%1\n"
-		"	ipm	%0\n"
-		"	srl	%0,28\n"
-		: "=d" (rc)
-		: "d" (fc)  : "cc");
-	return rc;
+		"	.insn	rre,0xb9a20000,%[fc],%[fc]\n"
+		CC_IPM(cc)
+		: CC_OUT(cc, cc)
+		: [fc] "d" (fc)
+		: CC_CLOBBER);
+	return CC_TRANSFORM(cc);
 }
 
 int topology_set_cpu_management(int fc)
 {
 	int cpu, rc;
 
-	if (!MACHINE_HAS_TOPOLOGY)
+	if (!cpu_has_topology())
 		return -EOPNOTSUPP;
 	if (fc)
 		rc = ptf(PTF_VERTICAL);
@@ -224,51 +253,91 @@ int topology_set_cpu_management(int fc)
 	return rc;
 }
 
-static void update_cpu_masks(void)
+void update_cpu_masks(void)
 {
-	unsigned long flags;
-	int cpu;
+	struct cpu_topology_s390 *topo, *topo_package, *topo_sibling;
+	int cpu, sibling, pkg_first, smt_first, id;
 
-	spin_lock_irqsave(&topology_lock, flags);
 	for_each_possible_cpu(cpu) {
-		cpu_topology[cpu].core_mask = cpu_group_map(&socket_info, cpu);
-		cpu_topology[cpu].book_mask = cpu_group_map(&book_info, cpu);
-		if (!MACHINE_HAS_TOPOLOGY) {
-			cpu_topology[cpu].core_id = cpu;
-			cpu_topology[cpu].socket_id = cpu;
-			cpu_topology[cpu].book_id = cpu;
+		topo = &cpu_topology[cpu];
+		cpu_thread_map(&topo->thread_mask, cpu);
+		cpu_group_map(&topo->core_mask, &socket_info, cpu);
+		cpu_group_map(&topo->book_mask, &book_info, cpu);
+		cpu_group_map(&topo->drawer_mask, &drawer_info, cpu);
+		topo->booted_cores = 0;
+		if (topology_mode != TOPOLOGY_MODE_HW) {
+			id = topology_mode == TOPOLOGY_MODE_PACKAGE ? 0 : cpu;
+			topo->thread_id = cpu;
+			topo->core_id = cpu;
+			topo->socket_id = id;
+			topo->book_id = id;
+			topo->drawer_id = id;
+		}
+	}
+	hd_reset_state();
+	for_each_online_cpu(cpu) {
+		topo = &cpu_topology[cpu];
+		pkg_first = cpumask_first(&topo->core_mask);
+		topo_package = &cpu_topology[pkg_first];
+		if (cpu == pkg_first) {
+			for_each_cpu(sibling, &topo->core_mask) {
+				topo_sibling = &cpu_topology[sibling];
+				smt_first = cpumask_first(&topo_sibling->thread_mask);
+				if (sibling == smt_first) {
+					topo_package->booted_cores++;
+					hd_add_core(sibling);
+				}
+			}
+		} else {
+			topo->booted_cores = topo_package->booted_cores;
 		}
 	}
-	spin_unlock_irqrestore(&topology_lock, flags);
 }
 
 void store_topology(struct sysinfo_15_1_x *info)
 {
-	if (topology_max_mnest >= 3)
-		stsi(info, 15, 1, 3);
+	stsi(info, 15, 1, topology_mnest_limit());
+}
+
+static void __arch_update_dedicated_flag(void *arg)
+{
+	if (topology_cpu_dedicated(smp_processor_id()))
+		set_cpu_flag(CIF_DEDICATED_CPU);
 	else
-		stsi(info, 15, 1, 2);
+		clear_cpu_flag(CIF_DEDICATED_CPU);
 }
 
-int arch_update_cpu_topology(void)
+static int __arch_update_cpu_topology(void)
 {
 	struct sysinfo_15_1_x *info = tl_info;
-	struct device *dev;
-	int cpu;
+	int rc, hd_status;
 
-	if (!MACHINE_HAS_TOPOLOGY) {
-		update_cpu_masks();
-		topology_update_polarization_simple();
-		return 0;
+	hd_status = 0;
+	rc = 0;
+	mutex_lock(&smp_cpu_state_mutex);
+	if (cpu_has_topology()) {
+		rc = 1;
+		store_topology(info);
+		tl_to_masks(info);
 	}
-	store_topology(info);
-	tl_to_masks(info);
 	update_cpu_masks();
-	for_each_online_cpu(cpu) {
-		dev = get_cpu_device(cpu);
-		kobject_uevent(&dev->kobj, KOBJ_CHANGE);
-	}
-	return 1;
+	if (!cpu_has_topology())
+		topology_update_polarization_simple();
+	if (cpu_management == 1)
+		hd_status = hd_enable_hiperdispatch();
+	mutex_unlock(&smp_cpu_state_mutex);
+	if (hd_status == 0)
+		hd_disable_hiperdispatch();
+	return rc;
+}
+
+int arch_update_cpu_topology(void)
+{
+	int rc;
+
+	rc = __arch_update_cpu_topology();
+	on_each_cpu(__arch_update_dedicated_flag, NULL, 0);
+	return rc;
 }
 
 static void topology_work_fn(struct work_struct *work)
@@ -281,29 +350,33 @@ void topology_schedule_update(void)
 	schedule_work(&topology_work);
 }
 
-static void topology_timer_fn(unsigned long ignored)
+static void topology_flush_work(void)
+{
+	flush_work(&topology_work);
+}
+
+static void topology_timer_fn(struct timer_list *unused)
 {
 	if (ptf(PTF_CHECK))
 		topology_schedule_update();
 	set_topology_timer();
 }
 
-static struct timer_list topology_timer =
-	TIMER_DEFERRED_INITIALIZER(topology_timer_fn, 0, 0);
+static struct timer_list topology_timer;
 
 static atomic_t topology_poll = ATOMIC_INIT(0);
 
 static void set_topology_timer(void)
 {
 	if (atomic_add_unless(&topology_poll, -1, 0))
-		mod_timer(&topology_timer, jiffies + HZ / 10);
+		mod_timer(&topology_timer, jiffies + msecs_to_jiffies(100));
 	else
-		mod_timer(&topology_timer, jiffies + HZ * 60);
+		mod_timer(&topology_timer, jiffies + secs_to_jiffies(60));
 }
 
 void topology_expect_change(void)
 {
-	if (!MACHINE_HAS_TOPOLOGY)
+	if (!cpu_has_topology())
 		return;
 	/* This is racy, but it doesn't matter since it is just a heuristic.
 	 * Worst case is that we poll in a higher frequency for a bit longer.
@@ -314,50 +387,25 @@ void topology_expect_change(void)
 	set_topology_timer();
 }
 
-static int __init early_parse_topology(char *p)
+static int set_polarization(int polarization)
 {
-	if (strncmp(p, "off", 3))
-		return 0;
-	topology_enabled = 0;
-	return 0;
-}
-early_param("topology", early_parse_topology);
-
-static void __init alloc_masks(struct sysinfo_15_1_x *info,
-			       struct mask_info *mask, int offset)
-{
-	int i, nr_masks;
+	int rc = 0;
 
-	nr_masks = info->mag[TOPOLOGY_NR_MAG - offset];
-	for (i = 0; i < info->mnest - offset; i++)
-		nr_masks *= info->mag[TOPOLOGY_NR_MAG - offset - 1 - i];
-	nr_masks = max(nr_masks, 1);
-	for (i = 0; i < nr_masks; i++) {
-		mask->next = alloc_bootmem(sizeof(struct mask_info));
-		mask = mask->next;
-	}
-}
-
-void __init s390_init_cpu_topology(void)
-{
-	struct sysinfo_15_1_x *info;
-	int i;
-
-	if (!MACHINE_HAS_TOPOLOGY)
-		return;
-	tl_info = alloc_bootmem_pages(PAGE_SIZE);
-	info = tl_info;
-	store_topology(info);
-	pr_info("The CPU configuration topology of the machine is:");
-	for (i = 0; i < TOPOLOGY_NR_MAG; i++)
-		printk(KERN_CONT " %d", info->mag[i]);
-	printk(KERN_CONT " / %d\n", info->mnest);
-	alloc_masks(info, &socket_info, 1);
-	alloc_masks(info, &book_info, 2);
+	cpus_read_lock();
+	mutex_lock(&smp_cpu_state_mutex);
+	if (cpu_management == polarization)
+		goto out;
+	rc = topology_set_cpu_management(polarization);
+	if (rc)
+		goto out;
+	cpu_management = polarization;
+	topology_expect_change();
+out:
+	mutex_unlock(&smp_cpu_state_mutex);
+	cpus_read_unlock();
+	return rc;
 }
 
-static int cpu_management;
-
 static ssize_t dispatching_show(struct device *dev,
 				struct device_attribute *attr,
 				char *buf)
@@ -365,7 +413,7 @@ static ssize_t dispatching_show(struct device *dev,
 	ssize_t count;
 
 	mutex_lock(&smp_cpu_state_mutex);
-	count = sprintf(buf, "%d\n", cpu_management);
+	count = sysfs_emit(buf, "%d\n", cpu_management);
 	mutex_unlock(&smp_cpu_state_mutex);
 	return count;
 }
@@ -382,23 +430,10 @@ static ssize_t dispatching_store(struct device *dev,
 		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)
-		goto out;
-	cpu_management = val;
-	topology_expect_change();
-out:
-	mutex_unlock(&smp_cpu_state_mutex);
-	put_online_cpus();
+	rc = set_polarization(val);
 	return rc ? rc : count;
 }
-static DEVICE_ATTR(dispatching, 0644, dispatching_show,
-			 dispatching_store);
+static DEVICE_ATTR_RW(dispatching);
 
 static ssize_t cpu_polarization_show(struct device *dev,
 				     struct device_attribute *attr, char *buf)
@@ -409,19 +444,19 @@ static ssize_t cpu_polarization_show(struct device *dev,
 	mutex_lock(&smp_cpu_state_mutex);
 	switch (smp_cpu_get_polarization(cpu)) {
 	case POLARIZATION_HRZ:
-		count = sprintf(buf, "horizontal\n");
+		count = sysfs_emit(buf, "horizontal\n");
 		break;
 	case POLARIZATION_VL:
-		count = sprintf(buf, "vertical:low\n");
+		count = sysfs_emit(buf, "vertical:low\n");
 		break;
 	case POLARIZATION_VM:
-		count = sprintf(buf, "vertical:medium\n");
+		count = sysfs_emit(buf, "vertical:medium\n");
 		break;
 	case POLARIZATION_VH:
-		count = sprintf(buf, "vertical:high\n");
+		count = sysfs_emit(buf, "vertical:high\n");
 		break;
 	default:
-		count = sprintf(buf, "unknown\n");
+		count = sysfs_emit(buf, "unknown\n");
 		break;
 	}
 	mutex_unlock(&smp_cpu_state_mutex);
@@ -438,20 +473,226 @@ static struct attribute_group topology_cpu_attr_group = {
 	.attrs = topology_cpu_attrs,
 };
 
+static ssize_t cpu_dedicated_show(struct device *dev,
+				  struct device_attribute *attr, char *buf)
+{
+	int cpu = dev->id;
+	ssize_t count;
+
+	mutex_lock(&smp_cpu_state_mutex);
+	count = sysfs_emit(buf, "%d\n", topology_cpu_dedicated(cpu));
+	mutex_unlock(&smp_cpu_state_mutex);
+	return count;
+}
+static DEVICE_ATTR(dedicated, 0444, cpu_dedicated_show, NULL);
+
+static struct attribute *topology_extra_cpu_attrs[] = {
+	&dev_attr_dedicated.attr,
+	NULL,
+};
+
+static struct attribute_group topology_extra_cpu_attr_group = {
+	.attrs = topology_extra_cpu_attrs,
+};
+
 int topology_cpu_init(struct cpu *cpu)
 {
-	return sysfs_create_group(&cpu->dev.kobj, &topology_cpu_attr_group);
+	int rc;
+
+	rc = sysfs_create_group(&cpu->dev.kobj, &topology_cpu_attr_group);
+	if (rc || !cpu_has_topology())
+		return rc;
+	rc = sysfs_create_group(&cpu->dev.kobj, &topology_extra_cpu_attr_group);
+	if (rc)
+		sysfs_remove_group(&cpu->dev.kobj, &topology_cpu_attr_group);
+	return rc;
+}
+
+const struct cpumask *cpu_coregroup_mask(int cpu)
+{
+	return &cpu_topology[cpu].core_mask;
+}
+
+static const struct cpumask *tl_book_mask(struct sched_domain_topology_level *tl, int cpu)
+{
+	return &cpu_topology[cpu].book_mask;
+}
+
+static const struct cpumask *tl_drawer_mask(struct sched_domain_topology_level *tl, int cpu)
+{
+	return &cpu_topology[cpu].drawer_mask;
+}
+
+static struct sched_domain_topology_level s390_topology[] = {
+	SDTL_INIT(tl_smt_mask, cpu_smt_flags, SMT),
+	SDTL_INIT(tl_mc_mask, cpu_core_flags, MC),
+	SDTL_INIT(tl_book_mask, NULL, BOOK),
+	SDTL_INIT(tl_drawer_mask, NULL, DRAWER),
+	SDTL_INIT(tl_pkg_mask, NULL, PKG),
+	{ NULL, },
+};
+
+static void __init alloc_masks(struct sysinfo_15_1_x *info,
+			       struct mask_info *mask, int offset)
+{
+	int i, nr_masks;
+
+	nr_masks = info->mag[TOPOLOGY_NR_MAG - offset];
+	for (i = 0; i < info->mnest - offset; i++)
+		nr_masks *= info->mag[TOPOLOGY_NR_MAG - offset - 1 - i];
+	nr_masks = max(nr_masks, 1);
+	for (i = 0; i < nr_masks; i++) {
+		mask->next = memblock_alloc_or_panic(sizeof(*mask->next), 8);
+		mask = mask->next;
+	}
+}
+
+static int __init detect_polarization(union topology_entry *tle)
+{
+	struct topology_core *tl_core;
+
+	while (tle->nl)
+		tle = next_tle(tle);
+	tl_core = (struct topology_core *)tle;
+	return tl_core->pp != POLARIZATION_HRZ;
+}
+
+void __init topology_init_early(void)
+{
+	struct sysinfo_15_1_x *info;
+
+	set_sched_topology(s390_topology);
+	if (topology_mode == TOPOLOGY_MODE_UNINITIALIZED) {
+		if (cpu_has_topology())
+			topology_mode = TOPOLOGY_MODE_HW;
+		else
+			topology_mode = TOPOLOGY_MODE_SINGLE;
+	}
+	if (!cpu_has_topology())
+		goto out;
+	tl_info = memblock_alloc_or_panic(PAGE_SIZE, PAGE_SIZE);
+	info = tl_info;
+	store_topology(info);
+	cpu_management = detect_polarization(info->tle);
+	pr_info("The CPU configuration topology of the machine is: %d %d %d %d %d %d / %d\n",
+		info->mag[0], info->mag[1], info->mag[2], info->mag[3],
+		info->mag[4], info->mag[5], info->mnest);
+	alloc_masks(info, &socket_info, 1);
+	alloc_masks(info, &book_info, 2);
+	alloc_masks(info, &drawer_info, 3);
+out:
+	cpumask_set_cpu(0, &cpu_setup_mask);
+	__arch_update_cpu_topology();
+	__arch_update_dedicated_flag(NULL);
+}
+
+static inline int topology_get_mode(int enabled)
+{
+	if (!enabled)
+		return TOPOLOGY_MODE_SINGLE;
+	return cpu_has_topology() ? TOPOLOGY_MODE_HW : TOPOLOGY_MODE_PACKAGE;
 }
 
+static inline int topology_is_enabled(void)
+{
+	return topology_mode != TOPOLOGY_MODE_SINGLE;
+}
+
+static int __init topology_setup(char *str)
+{
+	bool enabled;
+	int rc;
+
+	rc = kstrtobool(str, &enabled);
+	if (rc)
+		return rc;
+	topology_mode = topology_get_mode(enabled);
+	return 0;
+}
+early_param("topology", topology_setup);
+
+static int topology_ctl_handler(const struct ctl_table *ctl, int write,
+				void *buffer, size_t *lenp, loff_t *ppos)
+{
+	int enabled = topology_is_enabled();
+	int new_mode;
+	int rc;
+	struct ctl_table ctl_entry = {
+		.procname	= ctl->procname,
+		.data		= &enabled,
+		.maxlen		= sizeof(int),
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= SYSCTL_ONE,
+	};
+
+	rc = proc_douintvec_minmax(&ctl_entry, write, buffer, lenp, ppos);
+	if (rc < 0 || !write)
+		return rc;
+
+	mutex_lock(&smp_cpu_state_mutex);
+	new_mode = topology_get_mode(enabled);
+	if (topology_mode != new_mode) {
+		topology_mode = new_mode;
+		topology_schedule_update();
+	}
+	mutex_unlock(&smp_cpu_state_mutex);
+	topology_flush_work();
+
+	return rc;
+}
+
+static int polarization_ctl_handler(const struct ctl_table *ctl, int write,
+				    void *buffer, size_t *lenp, loff_t *ppos)
+{
+	int polarization;
+	int rc;
+	struct ctl_table ctl_entry = {
+		.procname	= ctl->procname,
+		.data		= &polarization,
+		.maxlen		= sizeof(int),
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= SYSCTL_ONE,
+	};
+
+	polarization = cpu_management;
+	rc = proc_douintvec_minmax(&ctl_entry, write, buffer, lenp, ppos);
+	if (rc < 0 || !write)
+		return rc;
+	return set_polarization(polarization);
+}
+
+static const struct ctl_table topology_ctl_table[] = {
+	{
+		.procname	= "topology",
+		.mode		= 0644,
+		.proc_handler	= topology_ctl_handler,
+	},
+	{
+		.procname	= "polarization",
+		.mode		= 0644,
+		.proc_handler	= polarization_ctl_handler,
+	},
+};
+
 static int __init topology_init(void)
 {
-	if (!MACHINE_HAS_TOPOLOGY) {
+	struct device *dev_root;
+	int rc = 0;
+
+	timer_setup(&topology_timer, topology_timer_fn, TIMER_DEFERRABLE);
+	if (cpu_has_topology())
+		set_topology_timer();
+	else
 		topology_update_polarization_simple();
-		goto out;
+	if (IS_ENABLED(CONFIG_SCHED_TOPOLOGY_VERTICAL))
+		set_polarization(1);
+	register_sysctl("s390", topology_ctl_table);
+
+	dev_root = bus_get_dev_root(&cpu_subsys);
+	if (dev_root) {
+		rc = device_create_file(dev_root, &dev_attr_dispatching);
+		put_device(dev_root);
 	}
-	set_topology_timer();
-out:
-	update_cpu_masks();
-	return device_create_file(cpu_subsys.dev_root, &dev_attr_dispatching);
+	return rc;
 }
 device_initcall(topology_init);