Commit-ID: a12486641cddbe825d0441140c7f43e30096bf70
Gitweb: https://git.kernel.org/tip/a12486641cddbe825d0441140c7f43e30096bf70
Author: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
AuthorDate: Wed, 3 Jul 2019 15:27:24 -0700
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Mon, 8 Jul 2019 14:52:27 +0200
cpu/hotplug: Fix CONFIG_SYSFS=n build errors
Following link errors happen when building a almost-allmodconfig but
CONFIG_SYSFS is not set/enabled:
ld: arch/x86/power/cpu.o: in function `hibernate_resume_nonboot_cpu_disable':
cpu.c:(.text+0x9f4): undefined reference to `cpuhp_smt_enable'
ld: arch/x86/power/hibernate.o: in function `arch_resume_nosmt':
hibernate.c:(.text+0x7f7): undefined reference to `cpuhp_smt_enable'
ld: hibernate.c:(.text+0x809): undefined reference to `cpuhp_smt_disable'
The missing functions should not be inside #if CONFIG_SYSFS/#endif. Moving
them around and adjusting the #ifdeffery makes also the non-SYSFS stub for
__store_smt_control() obsolete.
No functional change.
Fixes: 98f8cdce1db5 ("cpu/hotplug: Add sysfs state interface")
Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: https://lkml.kernel.org/r/9906a70d-7a4a-03a1-f555-07231570364d@xxxxxxxxxxxxx
---
kernel/cpu.c | 242 +++++++++++++++++++++++++++++------------------------------
1 file changed, 118 insertions(+), 124 deletions(-)
diff --git a/kernel/cpu.c b/kernel/cpu.c
index ef1c565edc5d..1eec77e7950e 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -376,7 +376,7 @@ static void lockdep_release_cpus_lock(void)
{
}
-#endif /* CONFIG_HOTPLUG_CPU */
+#endif /* CONFIG_HOTPLUG_CPU */
/*
* Architectures that need SMT-specific errata handling during SMT hotplug
@@ -1892,6 +1892,123 @@ void __cpuhp_remove_state(enum cpuhp_state state, bool invoke)
}
EXPORT_SYMBOL(__cpuhp_remove_state);
+#ifdef CONFIG_HOTPLUG_CPU
+
+static void cpuhp_offline_cpu_device(unsigned int cpu)
+{
+ struct device *dev = get_cpu_device(cpu);
+
+ dev->offline = true;
+ /* Tell user space about the state change */
+ kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
+}
+
+static void cpuhp_online_cpu_device(unsigned int cpu)
+{
+ struct device *dev = get_cpu_device(cpu);
+
+ dev->offline = false;
+ /* Tell user space about the state change */
+ kobject_uevent(&dev->kobj, KOBJ_ONLINE);
+}
+
+int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval)
+{
+ int cpu, ret = 0;
+
+ cpu_maps_update_begin();
+ for_each_online_cpu(cpu) {
+ if (topology_is_primary_thread(cpu))
+ continue;
+ ret = cpu_down_maps_locked(cpu, CPUHP_OFFLINE);
+ if (ret)
+ break;
+ /*
+ * As this needs to hold the cpu maps lock it's impossible
+ * to call device_offline() because that ends up calling
+ * cpu_down() which takes cpu maps lock. cpu maps lock
+ * needs to be held as this might race against in kernel
+ * abusers of the hotplug machinery (thermal management).
+ *
+ * So nothing would update device:offline state. That would
+ * leave the sysfs entry stale and prevent onlining after
+ * smt control has been changed to 'off' again. This is
+ * called under the sysfs hotplug lock, so it is properly
+ * serialized against the regular offline usage.
+ */
+ cpuhp_offline_cpu_device(cpu);
+ }
+ if (!ret)
+ cpu_smt_control = ctrlval;
+ cpu_maps_update_done();
+ return ret;
+}
+
+int cpuhp_smt_enable(void)
+{
+ int cpu, ret = 0;
+
+ cpu_maps_update_begin();
+ cpu_smt_control = CPU_SMT_ENABLED;
+ for_each_present_cpu(cpu) {
+ /* Skip online CPUs and CPUs on offline nodes */
+ if (cpu_online(cpu) || !node_online(cpu_to_node(cpu)))
+ continue;
+ ret = _cpu_up(cpu, 0, CPUHP_ONLINE);
+ if (ret)
+ break;
+ /* See comment in cpuhp_smt_disable() */
+ cpuhp_online_cpu_device(cpu);
+ }
+ cpu_maps_update_done();
+ return ret;
+}
+
+#if defined(CONFIG_HOTPLUG_SMT) && defined(CONFIG_SYSFS)
+static ssize_t
+__store_smt_control(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ int ctrlval, ret;
+
+ if (sysfs_streq(buf, "on"))
+ ctrlval = CPU_SMT_ENABLED;
+ else if (sysfs_streq(buf, "off"))
+ ctrlval = CPU_SMT_DISABLED;
+ else if (sysfs_streq(buf, "forceoff"))
+ ctrlval = CPU_SMT_FORCE_DISABLED;
+ else
+ return -EINVAL;
+
+ if (cpu_smt_control == CPU_SMT_FORCE_DISABLED)
+ return -EPERM;
+
+ if (cpu_smt_control == CPU_SMT_NOT_SUPPORTED)
+ return -ENODEV;
+
+ ret = lock_device_hotplug_sysfs();
+ if (ret)
+ return ret;
+
+ if (ctrlval != cpu_smt_control) {
+ switch (ctrlval) {
+ case CPU_SMT_ENABLED:
+ ret = cpuhp_smt_enable();
+ break;
+ case CPU_SMT_DISABLED:
+ case CPU_SMT_FORCE_DISABLED:
+ ret = cpuhp_smt_disable(ctrlval);
+ break;
+ }
+ }
+
+ unlock_device_hotplug();
+ return ret ? ret : count;
+}
+#endif /* CONFIG_HOTPLUG_SMT && CONFIG_SYSFS */
+
+#endif /* CONFIG_HOTPLUG_CPU */
+
#if defined(CONFIG_SYSFS) && defined(CONFIG_HOTPLUG_CPU)
static ssize_t show_cpuhp_state(struct device *dev,
struct device_attribute *attr, char *buf)
@@ -2044,129 +2161,6 @@ static const struct attribute_group cpuhp_cpu_root_attr_group = {
NULL
};
-#ifdef CONFIG_HOTPLUG_SMT
-
-static void cpuhp_offline_cpu_device(unsigned int cpu)
-{
- struct device *dev = get_cpu_device(cpu);
-
- dev->offline = true;
- /* Tell user space about the state change */
- kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
-}
-
-static void cpuhp_online_cpu_device(unsigned int cpu)
-{
- struct device *dev = get_cpu_device(cpu);
-
- dev->offline = false;
- /* Tell user space about the state change */
- kobject_uevent(&dev->kobj, KOBJ_ONLINE);
-}
-
-int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval)
-{
- int cpu, ret = 0;
-
- cpu_maps_update_begin();
- for_each_online_cpu(cpu) {
- if (topology_is_primary_thread(cpu))
- continue;
- ret = cpu_down_maps_locked(cpu, CPUHP_OFFLINE);
- if (ret)
- break;
- /*
- * As this needs to hold the cpu maps lock it's impossible
- * to call device_offline() because that ends up calling
- * cpu_down() which takes cpu maps lock. cpu maps lock
- * needs to be held as this might race against in kernel
- * abusers of the hotplug machinery (thermal management).
- *
- * So nothing would update device:offline state. That would
- * leave the sysfs entry stale and prevent onlining after
- * smt control has been changed to 'off' again. This is
- * called under the sysfs hotplug lock, so it is properly
- * serialized against the regular offline usage.
- */
- cpuhp_offline_cpu_device(cpu);
- }
- if (!ret)
- cpu_smt_control = ctrlval;
- cpu_maps_update_done();
- return ret;
-}
-
-int cpuhp_smt_enable(void)
-{
- int cpu, ret = 0;
-
- cpu_maps_update_begin();
- cpu_smt_control = CPU_SMT_ENABLED;
- for_each_present_cpu(cpu) {
- /* Skip online CPUs and CPUs on offline nodes */
- if (cpu_online(cpu) || !node_online(cpu_to_node(cpu)))
- continue;
- ret = _cpu_up(cpu, 0, CPUHP_ONLINE);
- if (ret)
- break;
- /* See comment in cpuhp_smt_disable() */
- cpuhp_online_cpu_device(cpu);
- }
- cpu_maps_update_done();
- return ret;
-}
-
-
-static ssize_t
-__store_smt_control(struct device *dev, struct device_attribute *attr,
- const char *buf, size_t count)
-{
- int ctrlval, ret;
-
- if (sysfs_streq(buf, "on"))
- ctrlval = CPU_SMT_ENABLED;
- else if (sysfs_streq(buf, "off"))
- ctrlval = CPU_SMT_DISABLED;
- else if (sysfs_streq(buf, "forceoff"))
- ctrlval = CPU_SMT_FORCE_DISABLED;
- else
- return -EINVAL;
-
- if (cpu_smt_control == CPU_SMT_FORCE_DISABLED)
- return -EPERM;
-
- if (cpu_smt_control == CPU_SMT_NOT_SUPPORTED)
- return -ENODEV;
-
- ret = lock_device_hotplug_sysfs();
- if (ret)
- return ret;
-
- if (ctrlval != cpu_smt_control) {
- switch (ctrlval) {
- case CPU_SMT_ENABLED:
- ret = cpuhp_smt_enable();
- break;
- case CPU_SMT_DISABLED:
- case CPU_SMT_FORCE_DISABLED:
- ret = cpuhp_smt_disable(ctrlval);
- break;
- }
- }
-
- unlock_device_hotplug();
- return ret ? ret : count;
-}
-
-#else /* !CONFIG_HOTPLUG_SMT */
-static ssize_t
-__store_smt_control(struct device *dev, struct device_attribute *attr,
- const char *buf, size_t count)
-{
- return -ENODEV;
-}
-#endif /* CONFIG_HOTPLUG_SMT */
-
static const char *smt_states[] = {
[CPU_SMT_ENABLED] = "on",
[CPU_SMT_DISABLED] = "off",
|