diff options
Diffstat (limited to 'drivers/idle/intel_idle.c')
| -rw-r--r-- | drivers/idle/intel_idle.c | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index 433d858b7be1..8ccb483204fa 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -48,9 +48,11 @@ #include <trace/events/power.h> #include <linux/sched.h> #include <linux/sched/smt.h> +#include <linux/mutex.h> #include <linux/notifier.h> #include <linux/cpu.h> #include <linux/moduleparam.h> +#include <linux/sysfs.h> #include <asm/cpuid/api.h> #include <asm/cpu_device_id.h> #include <asm/intel-family.h> @@ -93,9 +95,15 @@ struct idle_cpu { */ unsigned long auto_demotion_disable_flags; bool disable_promotion_to_c1e; + bool c1_demotion_supported; bool use_acpi; }; +static bool c1_demotion_supported; +static DEFINE_MUTEX(c1_demotion_mutex); + +static struct device *sysfs_root __initdata; + static const struct idle_cpu *icpu __initdata; static struct cpuidle_state *cpuidle_state_table __initdata; @@ -1550,18 +1558,21 @@ static const struct idle_cpu idle_cpu_gmt __initconst = { static const struct idle_cpu idle_cpu_spr __initconst = { .state_table = spr_cstates, .disable_promotion_to_c1e = true, + .c1_demotion_supported = true, .use_acpi = true, }; static const struct idle_cpu idle_cpu_gnr __initconst = { .state_table = gnr_cstates, .disable_promotion_to_c1e = true, + .c1_demotion_supported = true, .use_acpi = true, }; static const struct idle_cpu idle_cpu_gnrd __initconst = { .state_table = gnrd_cstates, .disable_promotion_to_c1e = true, + .c1_demotion_supported = true, .use_acpi = true, }; @@ -1600,12 +1611,14 @@ static const struct idle_cpu idle_cpu_snr __initconst = { static const struct idle_cpu idle_cpu_grr __initconst = { .state_table = grr_cstates, .disable_promotion_to_c1e = true, + .c1_demotion_supported = true, .use_acpi = true, }; static const struct idle_cpu idle_cpu_srf __initconst = { .state_table = srf_cstates, .disable_promotion_to_c1e = true, + .c1_demotion_supported = true, .use_acpi = true, }; @@ -2325,6 +2338,88 @@ static void __init intel_idle_cpuidle_devices_uninit(void) cpuidle_unregister_device(per_cpu_ptr(intel_idle_cpuidle_devices, i)); } +static void intel_c1_demotion_toggle(void *enable) +{ + unsigned long long msr_val; + + rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr_val); + /* + * Enable/disable C1 undemotion along with C1 demotion, as this is the + * most sensible configuration in general. + */ + if (enable) + msr_val |= NHM_C1_AUTO_DEMOTE | SNB_C1_AUTO_UNDEMOTE; + else + msr_val &= ~(NHM_C1_AUTO_DEMOTE | SNB_C1_AUTO_UNDEMOTE); + wrmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr_val); +} + +static ssize_t intel_c1_demotion_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + bool enable; + int err; + + err = kstrtobool(buf, &enable); + if (err) + return err; + + mutex_lock(&c1_demotion_mutex); + /* Enable/disable C1 demotion on all CPUs */ + on_each_cpu(intel_c1_demotion_toggle, (void *)enable, 1); + mutex_unlock(&c1_demotion_mutex); + + return count; +} + +static ssize_t intel_c1_demotion_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + unsigned long long msr_val; + + /* + * Read the MSR value for a CPU and assume it is the same for all CPUs. Any other + * configuration would be a BIOS bug. + */ + rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr_val); + return sysfs_emit(buf, "%d\n", !!(msr_val & NHM_C1_AUTO_DEMOTE)); +} +static DEVICE_ATTR_RW(intel_c1_demotion); + +static int __init intel_idle_sysfs_init(void) +{ + int err; + + if (!c1_demotion_supported) + return 0; + + sysfs_root = bus_get_dev_root(&cpu_subsys); + if (!sysfs_root) + return 0; + + err = sysfs_add_file_to_group(&sysfs_root->kobj, + &dev_attr_intel_c1_demotion.attr, + "cpuidle"); + if (err) { + put_device(sysfs_root); + return err; + } + + return 0; +} + +static void __init intel_idle_sysfs_uninit(void) +{ + if (!sysfs_root) + return; + + sysfs_remove_file_from_group(&sysfs_root->kobj, + &dev_attr_intel_c1_demotion.attr, + "cpuidle"); + put_device(sysfs_root); +} + static int __init intel_idle_init(void) { const struct x86_cpu_id *id; @@ -2375,6 +2470,8 @@ static int __init intel_idle_init(void) auto_demotion_disable_flags = icpu->auto_demotion_disable_flags; if (icpu->disable_promotion_to_c1e) c1e_promotion = C1E_PROMOTION_DISABLE; + if (icpu->c1_demotion_supported) + c1_demotion_supported = true; if (icpu->use_acpi || force_use_acpi) intel_idle_acpi_cst_extract(); } else if (!intel_idle_acpi_cst_extract()) { @@ -2388,6 +2485,10 @@ static int __init intel_idle_init(void) if (!intel_idle_cpuidle_devices) return -ENOMEM; + retval = intel_idle_sysfs_init(); + if (retval) + pr_warn("failed to initialized sysfs"); + intel_idle_cpuidle_driver_init(&intel_idle_driver); retval = cpuidle_register_driver(&intel_idle_driver); @@ -2412,6 +2513,7 @@ hp_setup_fail: intel_idle_cpuidle_devices_uninit(); cpuidle_unregister_driver(&intel_idle_driver); init_driver_fail: + intel_idle_sysfs_uninit(); free_percpu(intel_idle_cpuidle_devices); return retval; |