1 files changed, 180 insertions, 17 deletions

diff --git a/arch/s390/kernel/topology.c b/arch/s390/kernel/topology.c
index bb47c92476f0..f9b393d4a078 100644
--- a/arch/s390/kernel/topology.c
+++ b/arch/s390/kernel/topology.c
@@ -8,6 +8,8 @@
 
 #include <linux/workqueue.h>
 #include <linux/bootmem.h>
+#include <linux/uaccess.h>
+#include <linux/sysctl.h>
 #include <linux/cpuset.h>
 #include <linux/device.h>
 #include <linux/export.h>
@@ -29,12 +31,20 @@
 #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;
@@ -59,11 +69,26 @@ static cpumask_t cpu_group_map(struct mask_info *info, unsigned int cpu)
 	cpumask_t mask;
 
 	cpumask_copy(&mask, cpumask_of(cpu));
-	if (!MACHINE_HAS_TOPOLOGY)
-		return mask;
-	for (; info; info = info->next) {
-		if (cpumask_test_cpu(cpu, &info->mask))
-			return info->mask;
+	switch (topology_mode) {
+	case TOPOLOGY_MODE_HW:
+		while (info) {
+			if (cpumask_test_cpu(cpu, &info->mask)) {
+				mask = info->mask;
+				break;
+			}
+			info = info->next;
+		}
+		if (cpumask_empty(&mask))
+			cpumask_copy(&mask, cpumask_of(cpu));
+		break;
+	case TOPOLOGY_MODE_PACKAGE:
+		cpumask_copy(&mask, cpu_present_mask);
+		break;
+	default:
+		/* fallthrough */
+	case TOPOLOGY_MODE_SINGLE:
+		cpumask_copy(&mask, cpumask_of(cpu));
+		break;
 	}
 	return mask;
 }
@@ -74,7 +99,7 @@ static cpumask_t cpu_thread_map(unsigned int cpu)
 	int i;
 
 	cpumask_copy(&mask, cpumask_of(cpu));
-	if (!MACHINE_HAS_TOPOLOGY)
+	if (topology_mode != TOPOLOGY_MODE_HW)
 		return mask;
 	cpu -= cpu % (smp_cpu_mtid + 1);
 	for (i = 0; i <= smp_cpu_mtid; i++)
@@ -108,6 +133,7 @@ static void add_cpus_to_mask(struct topology_core *tl_core,
 			topo->socket_id = socket->id;
 			topo->core_id = rcore;
 			topo->thread_id = lcpu + i;
+			topo->dedicated = tl_core->d;
 			cpumask_set_cpu(lcpu + i, &drawer->mask);
 			cpumask_set_cpu(lcpu + i, &book->mask);
 			cpumask_set_cpu(lcpu + i, &socket->mask);
@@ -184,10 +210,8 @@ 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)
@@ -223,7 +247,7 @@ int topology_set_cpu_management(int fc)
 static void update_cpu_masks(void)
 {
 	struct cpu_topology_s390 *topo;
-	int cpu;
+	int cpu, id;
 
 	for_each_possible_cpu(cpu) {
 		topo = &cpu_topology[cpu];
@@ -231,12 +255,13 @@ static void update_cpu_masks(void)
 		topo->core_mask = cpu_group_map(&socket_info, cpu);
 		topo->book_mask = cpu_group_map(&book_info, cpu);
 		topo->drawer_mask = cpu_group_map(&drawer_info, cpu);
-		if (!MACHINE_HAS_TOPOLOGY) {
+		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 = cpu;
-			topo->book_id = cpu;
-			topo->drawer_id = cpu;
+			topo->socket_id = id;
+			topo->book_id = id;
+			topo->drawer_id = id;
 			if (cpu_present(cpu))
 				cpumask_set_cpu(cpu, &cpus_with_topology);
 		}
@@ -249,11 +274,20 @@ void store_topology(struct sysinfo_15_1_x *info)
 	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
+		clear_cpu_flag(CIF_DEDICATED_CPU);
+}
+
 static int __arch_update_cpu_topology(void)
 {
 	struct sysinfo_15_1_x *info = tl_info;
 	int rc = 0;
 
+	mutex_lock(&smp_cpu_state_mutex);
 	cpumask_clear(&cpus_with_topology);
 	if (MACHINE_HAS_TOPOLOGY) {
 		rc = 1;
@@ -263,6 +297,7 @@ static int __arch_update_cpu_topology(void)
 	update_cpu_masks();
 	if (!MACHINE_HAS_TOPOLOGY)
 		topology_update_polarization_simple();
+	mutex_unlock(&smp_cpu_state_mutex);
 	return rc;
 }
 
@@ -272,6 +307,7 @@ int arch_update_cpu_topology(void)
 	int cpu, rc;
 
 	rc = __arch_update_cpu_topology();
+	on_each_cpu(__arch_update_dedicated_flag, NULL, 0);
 	for_each_online_cpu(cpu) {
 		dev = get_cpu_device(cpu);
 		kobject_uevent(&dev->kobj, KOBJ_CHANGE);
@@ -289,15 +325,19 @@ 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);
 
@@ -404,9 +444,39 @@ 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 = sprintf(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 || !MACHINE_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;
 }
 
 static const struct cpumask *cpu_thread_mask(int cpu)
@@ -459,6 +529,12 @@ void __init topology_init_early(void)
 	struct sysinfo_15_1_x *info;
 
 	set_sched_topology(s390_topology);
+	if (topology_mode == TOPOLOGY_MODE_UNINITIALIZED) {
+		if (MACHINE_HAS_TOPOLOGY)
+			topology_mode = TOPOLOGY_MODE_HW;
+		else
+			topology_mode = TOPOLOGY_MODE_SINGLE;
+	}
 	if (!MACHINE_HAS_TOPOLOGY)
 		goto out;
 	tl_info = memblock_virt_alloc(PAGE_SIZE, PAGE_SIZE);
@@ -472,14 +548,101 @@ void __init topology_init_early(void)
 	alloc_masks(info, &drawer_info, 3);
 out:
 	__arch_update_cpu_topology();
+	__arch_update_dedicated_flag(NULL);
+}
+
+static inline int topology_get_mode(int enabled)
+{
+	if (!enabled)
+		return TOPOLOGY_MODE_SINGLE;
+	return MACHINE_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(struct ctl_table *ctl, int write,
+				void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+	unsigned int len;
+	int new_mode;
+	char buf[2];
+
+	if (!*lenp || *ppos) {
+		*lenp = 0;
+		return 0;
+	}
+	if (!write) {
+		strncpy(buf, topology_is_enabled() ? "1\n" : "0\n",
+			ARRAY_SIZE(buf));
+		len = strnlen(buf, ARRAY_SIZE(buf));
+		if (len > *lenp)
+			len = *lenp;
+		if (copy_to_user(buffer, buf, len))
+			return -EFAULT;
+		goto out;
+	}
+	len = *lenp;
+	if (copy_from_user(buf, buffer, len > sizeof(buf) ? sizeof(buf) : len))
+		return -EFAULT;
+	if (buf[0] != '0' && buf[0] != '1')
+		return -EINVAL;
+	mutex_lock(&smp_cpu_state_mutex);
+	new_mode = topology_get_mode(buf[0] == '1');
+	if (topology_mode != new_mode) {
+		topology_mode = new_mode;
+		topology_schedule_update();
+	}
+	mutex_unlock(&smp_cpu_state_mutex);
+	topology_flush_work();
+out:
+	*lenp = len;
+	*ppos += len;
+	return 0;
+}
+
+static struct ctl_table topology_ctl_table[] = {
+	{
+		.procname	= "topology",
+		.mode		= 0644,
+		.proc_handler	= topology_ctl_handler,
+	},
+	{ },
+};
+
+static struct ctl_table topology_dir_table[] = {
+	{
+		.procname	= "s390",
+		.maxlen		= 0,
+		.mode		= 0555,
+		.child		= topology_ctl_table,
+	},
+	{ },
+};
 
 static int __init topology_init(void)
 {
+	timer_setup(&topology_timer, topology_timer_fn, TIMER_DEFERRABLE);
 	if (MACHINE_HAS_TOPOLOGY)
 		set_topology_timer();
 	else
 		topology_update_polarization_simple();
+	register_sysctl_table(topology_dir_table);
 	return device_create_file(cpu_subsys.dev_root, &dev_attr_dispatching);
 }
 device_initcall(topology_init);