diff options
| -rw-r--r-- | Documentation/ABI/testing/sysfs-devices-system-cpu | 10 | ||||
| -rw-r--r-- | include/linux/cpu.h | 3 | ||||
| -rw-r--r-- | kernel/cpu.c | 64 |
3 files changed, 47 insertions, 30 deletions
diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu index 9605dbd4b5b5..5eea46fefcb2 100644 --- a/Documentation/ABI/testing/sysfs-devices-system-cpu +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -511,10 +511,12 @@ Description: Control Symetric Multi Threading (SMT) control: Read/write interface to control SMT. Possible values: - "on" SMT is enabled - "off" SMT is disabled - "forceoff" SMT is force disabled. Cannot be changed. - "notsupported" SMT is not supported by the CPU + "on" SMT is enabled + "off" SMT is disabled + "forceoff" SMT is force disabled. Cannot be changed. + "notsupported" SMT is not supported by the CPU + "notimplemented" SMT runtime toggling is not + implemented for the architecture If control status is "forceoff" or "notsupported" writes are rejected. diff --git a/include/linux/cpu.h b/include/linux/cpu.h index 5041357d0297..ae99dde02320 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -175,6 +175,7 @@ enum cpuhp_smt_control { CPU_SMT_DISABLED, CPU_SMT_FORCE_DISABLED, CPU_SMT_NOT_SUPPORTED, + CPU_SMT_NOT_IMPLEMENTED, }; #if defined(CONFIG_SMP) && defined(CONFIG_HOTPLUG_SMT) @@ -182,7 +183,7 @@ extern enum cpuhp_smt_control cpu_smt_control; extern void cpu_smt_disable(bool force); extern void cpu_smt_check_topology(void); #else -# define cpu_smt_control (CPU_SMT_ENABLED) +# define cpu_smt_control (CPU_SMT_NOT_IMPLEMENTED) static inline void cpu_smt_disable(bool force) { } static inline void cpu_smt_check_topology(void) { } #endif diff --git a/kernel/cpu.c b/kernel/cpu.c index 6754f3ecfd94..b8bf3f93e39b 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -2033,19 +2033,6 @@ static const struct attribute_group cpuhp_cpu_root_attr_group = { #ifdef CONFIG_HOTPLUG_SMT -static const char *smt_states[] = { - [CPU_SMT_ENABLED] = "on", - [CPU_SMT_DISABLED] = "off", - [CPU_SMT_FORCE_DISABLED] = "forceoff", - [CPU_SMT_NOT_SUPPORTED] = "notsupported", -}; - -static ssize_t -show_smt_control(struct device *dev, struct device_attribute *attr, char *buf) -{ - return snprintf(buf, PAGE_SIZE - 2, "%s\n", smt_states[cpu_smt_control]); -} - static void cpuhp_offline_cpu_device(unsigned int cpu) { struct device *dev = get_cpu_device(cpu); @@ -2116,9 +2103,10 @@ static int cpuhp_smt_enable(void) return ret; } + static ssize_t -store_smt_control(struct device *dev, struct device_attribute *attr, - const char *buf, size_t count) +__store_smt_control(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) { int ctrlval, ret; @@ -2156,14 +2144,44 @@ store_smt_control(struct device *dev, struct device_attribute *attr, 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", + [CPU_SMT_FORCE_DISABLED] = "forceoff", + [CPU_SMT_NOT_SUPPORTED] = "notsupported", + [CPU_SMT_NOT_IMPLEMENTED] = "notimplemented", +}; + +static ssize_t +show_smt_control(struct device *dev, struct device_attribute *attr, char *buf) +{ + const char *state = smt_states[cpu_smt_control]; + + return snprintf(buf, PAGE_SIZE - 2, "%s\n", state); +} + +static ssize_t +store_smt_control(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + return __store_smt_control(dev, attr, buf, count); +} static DEVICE_ATTR(control, 0644, show_smt_control, store_smt_control); static ssize_t show_smt_active(struct device *dev, struct device_attribute *attr, char *buf) { - bool active = topology_max_smt_threads() > 1; - - return snprintf(buf, PAGE_SIZE - 2, "%d\n", active); + return snprintf(buf, PAGE_SIZE - 2, "%d\n", sched_smt_active()); } static DEVICE_ATTR(active, 0444, show_smt_active, NULL); @@ -2179,21 +2197,17 @@ static const struct attribute_group cpuhp_smt_attr_group = { NULL }; -static int __init cpu_smt_state_init(void) +static int __init cpu_smt_sysfs_init(void) { return sysfs_create_group(&cpu_subsys.dev_root->kobj, &cpuhp_smt_attr_group); } -#else -static inline int cpu_smt_state_init(void) { return 0; } -#endif - static int __init cpuhp_sysfs_init(void) { int cpu, ret; - ret = cpu_smt_state_init(); + ret = cpu_smt_sysfs_init(); if (ret) return ret; @@ -2214,7 +2228,7 @@ static int __init cpuhp_sysfs_init(void) return 0; } device_initcall(cpuhp_sysfs_init); -#endif +#endif /* CONFIG_SYSFS && CONFIG_HOTPLUG_CPU */ /* * cpu_bit_bitmap[] is a special, "compressed" data structure that |