126717172SLen Brown /* 226717172SLen Brown * intel_idle.c - native hardware idle loop for modern Intel processors 326717172SLen Brown * 426717172SLen Brown * Copyright (c) 2010, Intel Corporation. 526717172SLen Brown * Len Brown <len.brown@intel.com> 626717172SLen Brown * 726717172SLen Brown * This program is free software; you can redistribute it and/or modify it 826717172SLen Brown * under the terms and conditions of the GNU General Public License, 926717172SLen Brown * version 2, as published by the Free Software Foundation. 1026717172SLen Brown * 1126717172SLen Brown * This program is distributed in the hope it will be useful, but WITHOUT 1226717172SLen Brown * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 1326717172SLen Brown * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 1426717172SLen Brown * more details. 1526717172SLen Brown * 1626717172SLen Brown * You should have received a copy of the GNU General Public License along with 1726717172SLen Brown * this program; if not, write to the Free Software Foundation, Inc., 1826717172SLen Brown * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. 1926717172SLen Brown */ 2026717172SLen Brown 2126717172SLen Brown /* 2226717172SLen Brown * intel_idle is a cpuidle driver that loads on specific Intel processors 2326717172SLen Brown * in lieu of the legacy ACPI processor_idle driver. The intent is to 2426717172SLen Brown * make Linux more efficient on these processors, as intel_idle knows 2526717172SLen Brown * more than ACPI, as well as make Linux more immune to ACPI BIOS bugs. 2626717172SLen Brown */ 2726717172SLen Brown 2826717172SLen Brown /* 2926717172SLen Brown * Design Assumptions 3026717172SLen Brown * 3126717172SLen Brown * All CPUs have same idle states as boot CPU 3226717172SLen Brown * 3326717172SLen Brown * Chipset BM_STS (bus master status) bit is a NOP 3426717172SLen Brown * for preventing entry into deep C-stats 3526717172SLen Brown */ 3626717172SLen Brown 3726717172SLen Brown /* 3826717172SLen Brown * Known limitations 3926717172SLen Brown * 4026717172SLen Brown * The driver currently initializes for_each_online_cpu() upon modprobe. 4126717172SLen Brown * It it unaware of subsequent processors hot-added to the system. 4226717172SLen Brown * This means that if you boot with maxcpus=n and later online 4326717172SLen Brown * processors above n, those processors will use C1 only. 4426717172SLen Brown * 4526717172SLen Brown * ACPI has a .suspend hack to turn off deep c-statees during suspend 4626717172SLen Brown * to avoid complications with the lapic timer workaround. 4726717172SLen Brown * Have not seen issues with suspend, but may need same workaround here. 4826717172SLen Brown * 4926717172SLen Brown * There is currently no kernel-based automatic probing/loading mechanism 5026717172SLen Brown * if the driver is built as a module. 5126717172SLen Brown */ 5226717172SLen Brown 5326717172SLen Brown /* un-comment DEBUG to enable pr_debug() statements */ 5426717172SLen Brown #define DEBUG 5526717172SLen Brown 5626717172SLen Brown #include <linux/kernel.h> 5726717172SLen Brown #include <linux/cpuidle.h> 5826717172SLen Brown #include <linux/clockchips.h> 5926717172SLen Brown #include <linux/hrtimer.h> /* ktime_get_real() */ 6026717172SLen Brown #include <trace/events/power.h> 6126717172SLen Brown #include <linux/sched.h> 62bc83ccccSH. Peter Anvin #include <asm/mwait.h> 6326717172SLen Brown 6426717172SLen Brown #define INTEL_IDLE_VERSION "0.4" 6526717172SLen Brown #define PREFIX "intel_idle: " 6626717172SLen Brown 6726717172SLen Brown static struct cpuidle_driver intel_idle_driver = { 6826717172SLen Brown .name = "intel_idle", 6926717172SLen Brown .owner = THIS_MODULE, 7026717172SLen Brown }; 7126717172SLen Brown /* intel_idle.max_cstate=0 disables driver */ 7226717172SLen Brown static int max_cstate = MWAIT_MAX_NUM_CSTATES - 1; 7326717172SLen Brown 74c4236282SLen Brown static unsigned int mwait_substates; 7526717172SLen Brown 7626717172SLen Brown /* Reliable LAPIC Timer States, bit 1 for C1 etc. */ 77d13780d4SLen Brown static unsigned int lapic_timer_reliable_states = (1 << 1); /* Default to only C1 */ 7826717172SLen Brown 793265eba0SNamhyung Kim static struct cpuidle_device __percpu *intel_idle_cpuidle_devices; 8026717172SLen Brown static int intel_idle(struct cpuidle_device *dev, struct cpuidle_state *state); 8126717172SLen Brown 8226717172SLen Brown static struct cpuidle_state *cpuidle_state_table; 8326717172SLen Brown 8426717172SLen Brown /* 8526717172SLen Brown * States are indexed by the cstate number, 8626717172SLen Brown * which is also the index into the MWAIT hint array. 8726717172SLen Brown * Thus C0 is a dummy. 8826717172SLen Brown */ 8926717172SLen Brown static struct cpuidle_state nehalem_cstates[MWAIT_MAX_NUM_CSTATES] = { 9026717172SLen Brown { /* MWAIT C0 */ }, 9126717172SLen Brown { /* MWAIT C1 */ 9226717172SLen Brown .name = "NHM-C1", 9326717172SLen Brown .desc = "MWAIT 0x00", 9426717172SLen Brown .driver_data = (void *) 0x00, 9526717172SLen Brown .flags = CPUIDLE_FLAG_TIME_VALID, 9626717172SLen Brown .exit_latency = 3, 9726717172SLen Brown .target_residency = 6, 9826717172SLen Brown .enter = &intel_idle }, 9926717172SLen Brown { /* MWAIT C2 */ 10026717172SLen Brown .name = "NHM-C3", 10126717172SLen Brown .desc = "MWAIT 0x10", 10226717172SLen Brown .driver_data = (void *) 0x10, 1036110a1f4SSuresh Siddha .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED, 10426717172SLen Brown .exit_latency = 20, 10526717172SLen Brown .target_residency = 80, 10626717172SLen Brown .enter = &intel_idle }, 10726717172SLen Brown { /* MWAIT C3 */ 10826717172SLen Brown .name = "NHM-C6", 10926717172SLen Brown .desc = "MWAIT 0x20", 11026717172SLen Brown .driver_data = (void *) 0x20, 1116110a1f4SSuresh Siddha .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED, 11226717172SLen Brown .exit_latency = 200, 11326717172SLen Brown .target_residency = 800, 11426717172SLen Brown .enter = &intel_idle }, 11526717172SLen Brown }; 11626717172SLen Brown 117d13780d4SLen Brown static struct cpuidle_state snb_cstates[MWAIT_MAX_NUM_CSTATES] = { 118d13780d4SLen Brown { /* MWAIT C0 */ }, 119d13780d4SLen Brown { /* MWAIT C1 */ 120d13780d4SLen Brown .name = "SNB-C1", 121d13780d4SLen Brown .desc = "MWAIT 0x00", 122d13780d4SLen Brown .driver_data = (void *) 0x00, 123d13780d4SLen Brown .flags = CPUIDLE_FLAG_TIME_VALID, 124d13780d4SLen Brown .exit_latency = 1, 125d13780d4SLen Brown .target_residency = 4, 126d13780d4SLen Brown .enter = &intel_idle }, 127d13780d4SLen Brown { /* MWAIT C2 */ 128d13780d4SLen Brown .name = "SNB-C3", 129d13780d4SLen Brown .desc = "MWAIT 0x10", 130d13780d4SLen Brown .driver_data = (void *) 0x10, 13100527cc6SLen Brown .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED, 132d13780d4SLen Brown .exit_latency = 80, 133d13780d4SLen Brown .target_residency = 160, 134d13780d4SLen Brown .enter = &intel_idle }, 135d13780d4SLen Brown { /* MWAIT C3 */ 136d13780d4SLen Brown .name = "SNB-C6", 137d13780d4SLen Brown .desc = "MWAIT 0x20", 138d13780d4SLen Brown .driver_data = (void *) 0x20, 13900527cc6SLen Brown .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED, 140d13780d4SLen Brown .exit_latency = 104, 141d13780d4SLen Brown .target_residency = 208, 142d13780d4SLen Brown .enter = &intel_idle }, 143d13780d4SLen Brown { /* MWAIT C4 */ 144d13780d4SLen Brown .name = "SNB-C7", 145d13780d4SLen Brown .desc = "MWAIT 0x30", 146d13780d4SLen Brown .driver_data = (void *) 0x30, 14700527cc6SLen Brown .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED, 148d13780d4SLen Brown .exit_latency = 109, 149d13780d4SLen Brown .target_residency = 300, 150d13780d4SLen Brown .enter = &intel_idle }, 151d13780d4SLen Brown }; 152d13780d4SLen Brown 15326717172SLen Brown static struct cpuidle_state atom_cstates[MWAIT_MAX_NUM_CSTATES] = { 15426717172SLen Brown { /* MWAIT C0 */ }, 15526717172SLen Brown { /* MWAIT C1 */ 15626717172SLen Brown .name = "ATM-C1", 15726717172SLen Brown .desc = "MWAIT 0x00", 15826717172SLen Brown .driver_data = (void *) 0x00, 15926717172SLen Brown .flags = CPUIDLE_FLAG_TIME_VALID, 16026717172SLen Brown .exit_latency = 1, 16126717172SLen Brown .target_residency = 4, 16226717172SLen Brown .enter = &intel_idle }, 16326717172SLen Brown { /* MWAIT C2 */ 16426717172SLen Brown .name = "ATM-C2", 16526717172SLen Brown .desc = "MWAIT 0x10", 16626717172SLen Brown .driver_data = (void *) 0x10, 16726717172SLen Brown .flags = CPUIDLE_FLAG_TIME_VALID, 16826717172SLen Brown .exit_latency = 20, 16926717172SLen Brown .target_residency = 80, 17026717172SLen Brown .enter = &intel_idle }, 17126717172SLen Brown { /* MWAIT C3 */ }, 17226717172SLen Brown { /* MWAIT C4 */ 17326717172SLen Brown .name = "ATM-C4", 17426717172SLen Brown .desc = "MWAIT 0x30", 17526717172SLen Brown .driver_data = (void *) 0x30, 1766110a1f4SSuresh Siddha .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED, 17726717172SLen Brown .exit_latency = 100, 17826717172SLen Brown .target_residency = 400, 17926717172SLen Brown .enter = &intel_idle }, 18026717172SLen Brown { /* MWAIT C5 */ }, 18126717172SLen Brown { /* MWAIT C6 */ 18226717172SLen Brown .name = "ATM-C6", 1837fcca7d9SLen Brown .desc = "MWAIT 0x52", 1847fcca7d9SLen Brown .driver_data = (void *) 0x52, 1856110a1f4SSuresh Siddha .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED, 1867fcca7d9SLen Brown .exit_latency = 140, 1877fcca7d9SLen Brown .target_residency = 560, 1887fcca7d9SLen Brown .enter = &intel_idle }, 18926717172SLen Brown }; 19026717172SLen Brown 19126717172SLen Brown /** 19226717172SLen Brown * intel_idle 19326717172SLen Brown * @dev: cpuidle_device 19426717172SLen Brown * @state: cpuidle state 19526717172SLen Brown * 19626717172SLen Brown */ 19726717172SLen Brown static int intel_idle(struct cpuidle_device *dev, struct cpuidle_state *state) 19826717172SLen Brown { 19926717172SLen Brown unsigned long ecx = 1; /* break on interrupt flag */ 20026717172SLen Brown unsigned long eax = (unsigned long)cpuidle_get_statedata(state); 20126717172SLen Brown unsigned int cstate; 20226717172SLen Brown ktime_t kt_before, kt_after; 20326717172SLen Brown s64 usec_delta; 20426717172SLen Brown int cpu = smp_processor_id(); 20526717172SLen Brown 20626717172SLen Brown cstate = (((eax) >> MWAIT_SUBSTATE_SIZE) & MWAIT_CSTATE_MASK) + 1; 20726717172SLen Brown 20826717172SLen Brown local_irq_disable(); 20926717172SLen Brown 2106110a1f4SSuresh Siddha /* 211c8381cc3SLen Brown * leave_mm() to avoid costly and often unnecessary wakeups 212c8381cc3SLen Brown * for flushing the user TLB's associated with the active mm. 2136110a1f4SSuresh Siddha */ 214c8381cc3SLen Brown if (state->flags & CPUIDLE_FLAG_TLB_FLUSHED) 2156110a1f4SSuresh Siddha leave_mm(cpu); 2166110a1f4SSuresh Siddha 21726717172SLen Brown if (!(lapic_timer_reliable_states & (1 << (cstate)))) 21826717172SLen Brown clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &cpu); 21926717172SLen Brown 22026717172SLen Brown kt_before = ktime_get_real(); 22126717172SLen Brown 22226717172SLen Brown stop_critical_timings(); 22326717172SLen Brown #ifndef MODULE 2248d91530cSLinus Torvalds trace_power_start(POWER_CSTATE, (eax >> 4) + 1, cpu); 22526717172SLen Brown #endif 22626717172SLen Brown if (!need_resched()) { 22726717172SLen Brown 22826717172SLen Brown __monitor((void *)¤t_thread_info()->flags, 0, 0); 22926717172SLen Brown smp_mb(); 23026717172SLen Brown if (!need_resched()) 23126717172SLen Brown __mwait(eax, ecx); 23226717172SLen Brown } 23326717172SLen Brown 23426717172SLen Brown start_critical_timings(); 23526717172SLen Brown 23626717172SLen Brown kt_after = ktime_get_real(); 23726717172SLen Brown usec_delta = ktime_to_us(ktime_sub(kt_after, kt_before)); 23826717172SLen Brown 23926717172SLen Brown local_irq_enable(); 24026717172SLen Brown 24126717172SLen Brown if (!(lapic_timer_reliable_states & (1 << (cstate)))) 24226717172SLen Brown clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu); 24326717172SLen Brown 24426717172SLen Brown return usec_delta; 24526717172SLen Brown } 24626717172SLen Brown 24726717172SLen Brown /* 24826717172SLen Brown * intel_idle_probe() 24926717172SLen Brown */ 25026717172SLen Brown static int intel_idle_probe(void) 25126717172SLen Brown { 252c4236282SLen Brown unsigned int eax, ebx, ecx; 25326717172SLen Brown 25426717172SLen Brown if (max_cstate == 0) { 25526717172SLen Brown pr_debug(PREFIX "disabled\n"); 25626717172SLen Brown return -EPERM; 25726717172SLen Brown } 25826717172SLen Brown 25926717172SLen Brown if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL) 26026717172SLen Brown return -ENODEV; 26126717172SLen Brown 26226717172SLen Brown if (!boot_cpu_has(X86_FEATURE_MWAIT)) 26326717172SLen Brown return -ENODEV; 26426717172SLen Brown 26526717172SLen Brown if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF) 26626717172SLen Brown return -ENODEV; 26726717172SLen Brown 268c4236282SLen Brown cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &mwait_substates); 26926717172SLen Brown 27026717172SLen Brown if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) || 27126717172SLen Brown !(ecx & CPUID5_ECX_INTERRUPT_BREAK)) 27226717172SLen Brown return -ENODEV; 27326717172SLen Brown 274c4236282SLen Brown pr_debug(PREFIX "MWAIT substates: 0x%x\n", mwait_substates); 27526717172SLen Brown 27626717172SLen Brown 27726717172SLen Brown if (boot_cpu_data.x86 != 6) /* family 6 */ 27826717172SLen Brown return -ENODEV; 27926717172SLen Brown 28026717172SLen Brown switch (boot_cpu_data.x86_model) { 28126717172SLen Brown 28226717172SLen Brown case 0x1A: /* Core i7, Xeon 5500 series */ 28326717172SLen Brown case 0x1E: /* Core i7 and i5 Processor - Lynnfield Jasper Forest */ 28426717172SLen Brown case 0x1F: /* Core i7 and i5 Processor - Nehalem */ 28526717172SLen Brown case 0x2E: /* Nehalem-EX Xeon */ 286ec67a2baSLen Brown case 0x2F: /* Westmere-EX Xeon */ 28726717172SLen Brown case 0x25: /* Westmere */ 28826717172SLen Brown case 0x2C: /* Westmere */ 28926717172SLen Brown cpuidle_state_table = nehalem_cstates; 29026717172SLen Brown break; 29126717172SLen Brown 29226717172SLen Brown case 0x1C: /* 28 - Atom Processor */ 2934725fd3cSArjan van de Ven case 0x26: /* 38 - Lincroft Atom Processor */ 29426717172SLen Brown cpuidle_state_table = atom_cstates; 29526717172SLen Brown break; 296d13780d4SLen Brown 297d13780d4SLen Brown case 0x2A: /* SNB */ 298d13780d4SLen Brown case 0x2D: /* SNB Xeon */ 299d13780d4SLen Brown cpuidle_state_table = snb_cstates; 300d13780d4SLen Brown break; 30126717172SLen Brown 30226717172SLen Brown default: 30326717172SLen Brown pr_debug(PREFIX "does not run on family %d model %d\n", 30426717172SLen Brown boot_cpu_data.x86, boot_cpu_data.x86_model); 30526717172SLen Brown return -ENODEV; 30626717172SLen Brown } 30726717172SLen Brown 30856b9aea3SLen Brown if (boot_cpu_has(X86_FEATURE_ARAT)) /* Always Reliable APIC Timer */ 30956b9aea3SLen Brown lapic_timer_reliable_states = 0xFFFFFFFF; 31056b9aea3SLen Brown 31126717172SLen Brown pr_debug(PREFIX "v" INTEL_IDLE_VERSION 31226717172SLen Brown " model 0x%X\n", boot_cpu_data.x86_model); 31326717172SLen Brown 31426717172SLen Brown pr_debug(PREFIX "lapic_timer_reliable_states 0x%x\n", 31526717172SLen Brown lapic_timer_reliable_states); 31626717172SLen Brown return 0; 31726717172SLen Brown } 31826717172SLen Brown 31926717172SLen Brown /* 32026717172SLen Brown * intel_idle_cpuidle_devices_uninit() 32126717172SLen Brown * unregister, free cpuidle_devices 32226717172SLen Brown */ 32326717172SLen Brown static void intel_idle_cpuidle_devices_uninit(void) 32426717172SLen Brown { 32526717172SLen Brown int i; 32626717172SLen Brown struct cpuidle_device *dev; 32726717172SLen Brown 32826717172SLen Brown for_each_online_cpu(i) { 32926717172SLen Brown dev = per_cpu_ptr(intel_idle_cpuidle_devices, i); 33026717172SLen Brown cpuidle_unregister_device(dev); 33126717172SLen Brown } 33226717172SLen Brown 33326717172SLen Brown free_percpu(intel_idle_cpuidle_devices); 33426717172SLen Brown return; 33526717172SLen Brown } 33626717172SLen Brown /* 33726717172SLen Brown * intel_idle_cpuidle_devices_init() 33826717172SLen Brown * allocate, initialize, register cpuidle_devices 33926717172SLen Brown */ 34026717172SLen Brown static int intel_idle_cpuidle_devices_init(void) 34126717172SLen Brown { 34226717172SLen Brown int i, cstate; 34326717172SLen Brown struct cpuidle_device *dev; 34426717172SLen Brown 34526717172SLen Brown intel_idle_cpuidle_devices = alloc_percpu(struct cpuidle_device); 34626717172SLen Brown if (intel_idle_cpuidle_devices == NULL) 34726717172SLen Brown return -ENOMEM; 34826717172SLen Brown 34926717172SLen Brown for_each_online_cpu(i) { 35026717172SLen Brown dev = per_cpu_ptr(intel_idle_cpuidle_devices, i); 35126717172SLen Brown 35226717172SLen Brown dev->state_count = 1; 35326717172SLen Brown 35426717172SLen Brown for (cstate = 1; cstate < MWAIT_MAX_NUM_CSTATES; ++cstate) { 35526717172SLen Brown int num_substates; 35626717172SLen Brown 35726717172SLen Brown if (cstate > max_cstate) { 35826717172SLen Brown printk(PREFIX "max_cstate %d reached\n", 35926717172SLen Brown max_cstate); 36026717172SLen Brown break; 36126717172SLen Brown } 36226717172SLen Brown 36326717172SLen Brown /* does the state exist in CPUID.MWAIT? */ 364c4236282SLen Brown num_substates = (mwait_substates >> ((cstate) * 4)) 36526717172SLen Brown & MWAIT_SUBSTATE_MASK; 36626717172SLen Brown if (num_substates == 0) 36726717172SLen Brown continue; 36826717172SLen Brown /* is the state not enabled? */ 36926717172SLen Brown if (cpuidle_state_table[cstate].enter == NULL) { 37026717172SLen Brown /* does the driver not know about the state? */ 37126717172SLen Brown if (*cpuidle_state_table[cstate].name == '\0') 37226717172SLen Brown pr_debug(PREFIX "unaware of model 0x%x" 37326717172SLen Brown " MWAIT %d please" 37426717172SLen Brown " contact lenb@kernel.org", 37526717172SLen Brown boot_cpu_data.x86_model, cstate); 37626717172SLen Brown continue; 37726717172SLen Brown } 37826717172SLen Brown 37926717172SLen Brown if ((cstate > 2) && 38026717172SLen Brown !boot_cpu_has(X86_FEATURE_NONSTOP_TSC)) 38126717172SLen Brown mark_tsc_unstable("TSC halts in idle" 38226717172SLen Brown " states deeper than C2"); 38326717172SLen Brown 38426717172SLen Brown dev->states[dev->state_count] = /* structure copy */ 38526717172SLen Brown cpuidle_state_table[cstate]; 38626717172SLen Brown 38726717172SLen Brown dev->state_count += 1; 38826717172SLen Brown } 38926717172SLen Brown 39026717172SLen Brown dev->cpu = i; 39126717172SLen Brown if (cpuidle_register_device(dev)) { 39226717172SLen Brown pr_debug(PREFIX "cpuidle_register_device %d failed!\n", 39326717172SLen Brown i); 39426717172SLen Brown intel_idle_cpuidle_devices_uninit(); 39526717172SLen Brown return -EIO; 39626717172SLen Brown } 39726717172SLen Brown } 39826717172SLen Brown 39926717172SLen Brown return 0; 40026717172SLen Brown } 40126717172SLen Brown 40226717172SLen Brown 40326717172SLen Brown static int __init intel_idle_init(void) 40426717172SLen Brown { 40526717172SLen Brown int retval; 40626717172SLen Brown 40726717172SLen Brown retval = intel_idle_probe(); 40826717172SLen Brown if (retval) 40926717172SLen Brown return retval; 41026717172SLen Brown 41126717172SLen Brown retval = cpuidle_register_driver(&intel_idle_driver); 41226717172SLen Brown if (retval) { 41326717172SLen Brown printk(KERN_DEBUG PREFIX "intel_idle yielding to %s", 41426717172SLen Brown cpuidle_get_driver()->name); 41526717172SLen Brown return retval; 41626717172SLen Brown } 41726717172SLen Brown 41826717172SLen Brown retval = intel_idle_cpuidle_devices_init(); 41926717172SLen Brown if (retval) { 42026717172SLen Brown cpuidle_unregister_driver(&intel_idle_driver); 42126717172SLen Brown return retval; 42226717172SLen Brown } 42326717172SLen Brown 42426717172SLen Brown return 0; 42526717172SLen Brown } 42626717172SLen Brown 42726717172SLen Brown static void __exit intel_idle_exit(void) 42826717172SLen Brown { 42926717172SLen Brown intel_idle_cpuidle_devices_uninit(); 43026717172SLen Brown cpuidle_unregister_driver(&intel_idle_driver); 43126717172SLen Brown 43226717172SLen Brown return; 43326717172SLen Brown } 43426717172SLen Brown 43526717172SLen Brown module_init(intel_idle_init); 43626717172SLen Brown module_exit(intel_idle_exit); 43726717172SLen Brown 43826717172SLen Brown module_param(max_cstate, int, 0444); 43926717172SLen Brown 44026717172SLen Brown MODULE_AUTHOR("Len Brown <len.brown@intel.com>"); 44126717172SLen Brown MODULE_DESCRIPTION("Cpuidle driver for Intel Hardware v" INTEL_IDLE_VERSION); 44226717172SLen Brown MODULE_LICENSE("GPL"); 443