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Diffstat (limited to 'arch/s390/kernel/topology.c')
-rw-r--r--arch/s390/kernel/topology.c148
1 files changed, 135 insertions, 13 deletions
diff --git a/arch/s390/kernel/topology.c b/arch/s390/kernel/topology.c
index bb47c92476f0..ed0bdd220e1a 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++)
@@ -184,10 +209,8 @@ 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 +246,7 @@ 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 +254,13 @@ 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);
}
@@ -254,6 +278,7 @@ 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 +288,7 @@ 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;
}
@@ -289,6 +315,11 @@ void topology_schedule_update(void)
schedule_work(&topology_work);
}
+static void topology_flush_work(void)
+{
+ flush_work(&topology_work);
+}
+
static void topology_timer_fn(unsigned long ignored)
{
if (ptf(PTF_CHECK))
@@ -459,6 +490,12 @@ 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);
@@ -474,12 +511,97 @@ out:
__arch_update_cpu_topology();
}
+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)
{
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);