11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * processor_idle - idle state submodule to the ACPI processor driver 31da177e4SLinus Torvalds * 41da177e4SLinus Torvalds * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com> 51da177e4SLinus Torvalds * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com> 6c5ab81caSDominik Brodowski * Copyright (C) 2004, 2005 Dominik Brodowski <linux@brodo.de> 71da177e4SLinus Torvalds * Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> 81da177e4SLinus Torvalds * - Added processor hotplug support 902df8b93SVenkatesh Pallipadi * Copyright (C) 2005 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> 1002df8b93SVenkatesh Pallipadi * - Added support for C3 on SMP 111da177e4SLinus Torvalds * 121da177e4SLinus Torvalds * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 131da177e4SLinus Torvalds * 141da177e4SLinus Torvalds * This program is free software; you can redistribute it and/or modify 151da177e4SLinus Torvalds * it under the terms of the GNU General Public License as published by 161da177e4SLinus Torvalds * the Free Software Foundation; either version 2 of the License, or (at 171da177e4SLinus Torvalds * your option) any later version. 181da177e4SLinus Torvalds * 191da177e4SLinus Torvalds * This program is distributed in the hope that it will be useful, but 201da177e4SLinus Torvalds * WITHOUT ANY WARRANTY; without even the implied warranty of 211da177e4SLinus Torvalds * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 221da177e4SLinus Torvalds * General Public License for more details. 231da177e4SLinus Torvalds * 241da177e4SLinus Torvalds * You should have received a copy of the GNU General Public License along 251da177e4SLinus Torvalds * with this program; if not, write to the Free Software Foundation, Inc., 261da177e4SLinus Torvalds * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. 271da177e4SLinus Torvalds * 281da177e4SLinus Torvalds * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 291da177e4SLinus Torvalds */ 301da177e4SLinus Torvalds 311da177e4SLinus Torvalds #include <linux/kernel.h> 321da177e4SLinus Torvalds #include <linux/module.h> 331da177e4SLinus Torvalds #include <linux/init.h> 341da177e4SLinus Torvalds #include <linux/cpufreq.h> 351da177e4SLinus Torvalds #include <linux/proc_fs.h> 361da177e4SLinus Torvalds #include <linux/seq_file.h> 371da177e4SLinus Torvalds #include <linux/acpi.h> 381da177e4SLinus Torvalds #include <linux/dmi.h> 391da177e4SLinus Torvalds #include <linux/moduleparam.h> 404e57b681STim Schmielau #include <linux/sched.h> /* need_resched() */ 415c87579eSArjan van de Ven #include <linux/latency.h> 421da177e4SLinus Torvalds 431da177e4SLinus Torvalds #include <asm/io.h> 441da177e4SLinus Torvalds #include <asm/uaccess.h> 451da177e4SLinus Torvalds 461da177e4SLinus Torvalds #include <acpi/acpi_bus.h> 471da177e4SLinus Torvalds #include <acpi/processor.h> 481da177e4SLinus Torvalds 491da177e4SLinus Torvalds #define ACPI_PROCESSOR_COMPONENT 0x01000000 501da177e4SLinus Torvalds #define ACPI_PROCESSOR_CLASS "processor" 511da177e4SLinus Torvalds #define ACPI_PROCESSOR_DRIVER_NAME "ACPI Processor Driver" 521da177e4SLinus Torvalds #define _COMPONENT ACPI_PROCESSOR_COMPONENT 531da177e4SLinus Torvalds ACPI_MODULE_NAME("acpi_processor") 541da177e4SLinus Torvalds #define ACPI_PROCESSOR_FILE_POWER "power" 551da177e4SLinus Torvalds #define US_TO_PM_TIMER_TICKS(t) ((t * (PM_TIMER_FREQUENCY/1000)) / 1000) 561da177e4SLinus Torvalds #define C2_OVERHEAD 4 /* 1us (3.579 ticks per us) */ 571da177e4SLinus Torvalds #define C3_OVERHEAD 4 /* 1us (3.579 ticks per us) */ 58b6835052SAndreas Mohr static void (*pm_idle_save) (void) __read_mostly; 591da177e4SLinus Torvalds module_param(max_cstate, uint, 0644); 601da177e4SLinus Torvalds 61b6835052SAndreas Mohr static unsigned int nocst __read_mostly; 621da177e4SLinus Torvalds module_param(nocst, uint, 0000); 631da177e4SLinus Torvalds 641da177e4SLinus Torvalds /* 651da177e4SLinus Torvalds * bm_history -- bit-mask with a bit per jiffy of bus-master activity 661da177e4SLinus Torvalds * 1000 HZ: 0xFFFFFFFF: 32 jiffies = 32ms 671da177e4SLinus Torvalds * 800 HZ: 0xFFFFFFFF: 32 jiffies = 40ms 681da177e4SLinus Torvalds * 100 HZ: 0x0000000F: 4 jiffies = 40ms 691da177e4SLinus Torvalds * reduce history for more aggressive entry into C3 701da177e4SLinus Torvalds */ 71b6835052SAndreas Mohr static unsigned int bm_history __read_mostly = 724be44fcdSLen Brown (HZ >= 800 ? 0xFFFFFFFF : ((1U << (HZ / 25)) - 1)); 731da177e4SLinus Torvalds module_param(bm_history, uint, 0644); 741da177e4SLinus Torvalds /* -------------------------------------------------------------------------- 751da177e4SLinus Torvalds Power Management 761da177e4SLinus Torvalds -------------------------------------------------------------------------- */ 771da177e4SLinus Torvalds 781da177e4SLinus Torvalds /* 791da177e4SLinus Torvalds * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3. 801da177e4SLinus Torvalds * For now disable this. Probably a bug somewhere else. 811da177e4SLinus Torvalds * 821da177e4SLinus Torvalds * To skip this limit, boot/load with a large max_cstate limit. 831da177e4SLinus Torvalds */ 84335f16beSDavid Shaohua Li static int set_max_cstate(struct dmi_system_id *id) 851da177e4SLinus Torvalds { 861da177e4SLinus Torvalds if (max_cstate > ACPI_PROCESSOR_MAX_POWER) 871da177e4SLinus Torvalds return 0; 881da177e4SLinus Torvalds 893d35600aSLen Brown printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate." 901da177e4SLinus Torvalds " Override with \"processor.max_cstate=%d\"\n", id->ident, 913d35600aSLen Brown (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1); 921da177e4SLinus Torvalds 933d35600aSLen Brown max_cstate = (long)id->driver_data; 941da177e4SLinus Torvalds 951da177e4SLinus Torvalds return 0; 961da177e4SLinus Torvalds } 971da177e4SLinus Torvalds 987ded5689SAshok Raj /* Actually this shouldn't be __cpuinitdata, would be better to fix the 997ded5689SAshok Raj callers to only run once -AK */ 1007ded5689SAshok Raj static struct dmi_system_id __cpuinitdata processor_power_dmi_table[] = { 101335f16beSDavid Shaohua Li { set_max_cstate, "IBM ThinkPad R40e", { 102876c184bSThomas Rosner DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 103f831335dSBartlomiej Swiercz DMI_MATCH(DMI_BIOS_VERSION,"1SET70WW")}, (void *)1}, 104f831335dSBartlomiej Swiercz { set_max_cstate, "IBM ThinkPad R40e", { 105f831335dSBartlomiej Swiercz DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 106876c184bSThomas Rosner DMI_MATCH(DMI_BIOS_VERSION,"1SET60WW")}, (void *)1}, 107876c184bSThomas Rosner { set_max_cstate, "IBM ThinkPad R40e", { 108876c184bSThomas Rosner DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 109876c184bSThomas Rosner DMI_MATCH(DMI_BIOS_VERSION,"1SET43WW") }, (void*)1}, 110876c184bSThomas Rosner { set_max_cstate, "IBM ThinkPad R40e", { 111876c184bSThomas Rosner DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 112876c184bSThomas Rosner DMI_MATCH(DMI_BIOS_VERSION,"1SET45WW") }, (void*)1}, 113876c184bSThomas Rosner { set_max_cstate, "IBM ThinkPad R40e", { 114876c184bSThomas Rosner DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 115876c184bSThomas Rosner DMI_MATCH(DMI_BIOS_VERSION,"1SET47WW") }, (void*)1}, 116876c184bSThomas Rosner { set_max_cstate, "IBM ThinkPad R40e", { 117876c184bSThomas Rosner DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 118876c184bSThomas Rosner DMI_MATCH(DMI_BIOS_VERSION,"1SET50WW") }, (void*)1}, 119876c184bSThomas Rosner { set_max_cstate, "IBM ThinkPad R40e", { 120876c184bSThomas Rosner DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 121876c184bSThomas Rosner DMI_MATCH(DMI_BIOS_VERSION,"1SET52WW") }, (void*)1}, 122876c184bSThomas Rosner { set_max_cstate, "IBM ThinkPad R40e", { 123876c184bSThomas Rosner DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 124876c184bSThomas Rosner DMI_MATCH(DMI_BIOS_VERSION,"1SET55WW") }, (void*)1}, 125876c184bSThomas Rosner { set_max_cstate, "IBM ThinkPad R40e", { 126876c184bSThomas Rosner DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 127876c184bSThomas Rosner DMI_MATCH(DMI_BIOS_VERSION,"1SET56WW") }, (void*)1}, 128876c184bSThomas Rosner { set_max_cstate, "IBM ThinkPad R40e", { 129876c184bSThomas Rosner DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 130876c184bSThomas Rosner DMI_MATCH(DMI_BIOS_VERSION,"1SET59WW") }, (void*)1}, 131876c184bSThomas Rosner { set_max_cstate, "IBM ThinkPad R40e", { 132876c184bSThomas Rosner DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 133876c184bSThomas Rosner DMI_MATCH(DMI_BIOS_VERSION,"1SET60WW") }, (void*)1}, 134876c184bSThomas Rosner { set_max_cstate, "IBM ThinkPad R40e", { 135876c184bSThomas Rosner DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 136876c184bSThomas Rosner DMI_MATCH(DMI_BIOS_VERSION,"1SET61WW") }, (void*)1}, 137876c184bSThomas Rosner { set_max_cstate, "IBM ThinkPad R40e", { 138876c184bSThomas Rosner DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 139876c184bSThomas Rosner DMI_MATCH(DMI_BIOS_VERSION,"1SET62WW") }, (void*)1}, 140876c184bSThomas Rosner { set_max_cstate, "IBM ThinkPad R40e", { 141876c184bSThomas Rosner DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 142876c184bSThomas Rosner DMI_MATCH(DMI_BIOS_VERSION,"1SET64WW") }, (void*)1}, 143876c184bSThomas Rosner { set_max_cstate, "IBM ThinkPad R40e", { 144876c184bSThomas Rosner DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 145876c184bSThomas Rosner DMI_MATCH(DMI_BIOS_VERSION,"1SET65WW") }, (void*)1}, 146876c184bSThomas Rosner { set_max_cstate, "IBM ThinkPad R40e", { 147876c184bSThomas Rosner DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 148876c184bSThomas Rosner DMI_MATCH(DMI_BIOS_VERSION,"1SET68WW") }, (void*)1}, 149335f16beSDavid Shaohua Li { set_max_cstate, "Medion 41700", { 150876c184bSThomas Rosner DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"), 151876c184bSThomas Rosner DMI_MATCH(DMI_BIOS_VERSION,"R01-A1J")}, (void *)1}, 152335f16beSDavid Shaohua Li { set_max_cstate, "Clevo 5600D", { 153876c184bSThomas Rosner DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"), 154876c184bSThomas Rosner DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")}, 155335f16beSDavid Shaohua Li (void *)2}, 1561da177e4SLinus Torvalds {}, 1571da177e4SLinus Torvalds }; 1581da177e4SLinus Torvalds 1594be44fcdSLen Brown static inline u32 ticks_elapsed(u32 t1, u32 t2) 1601da177e4SLinus Torvalds { 1611da177e4SLinus Torvalds if (t2 >= t1) 1621da177e4SLinus Torvalds return (t2 - t1); 1631da177e4SLinus Torvalds else if (!acpi_fadt.tmr_val_ext) 1641da177e4SLinus Torvalds return (((0x00FFFFFF - t1) + t2) & 0x00FFFFFF); 1651da177e4SLinus Torvalds else 1661da177e4SLinus Torvalds return ((0xFFFFFFFF - t1) + t2); 1671da177e4SLinus Torvalds } 1681da177e4SLinus Torvalds 1691da177e4SLinus Torvalds static void 1704be44fcdSLen Brown acpi_processor_power_activate(struct acpi_processor *pr, 1711da177e4SLinus Torvalds struct acpi_processor_cx *new) 1721da177e4SLinus Torvalds { 1731da177e4SLinus Torvalds struct acpi_processor_cx *old; 1741da177e4SLinus Torvalds 1751da177e4SLinus Torvalds if (!pr || !new) 1761da177e4SLinus Torvalds return; 1771da177e4SLinus Torvalds 1781da177e4SLinus Torvalds old = pr->power.state; 1791da177e4SLinus Torvalds 1801da177e4SLinus Torvalds if (old) 1811da177e4SLinus Torvalds old->promotion.count = 0; 1821da177e4SLinus Torvalds new->demotion.count = 0; 1831da177e4SLinus Torvalds 1841da177e4SLinus Torvalds /* Cleanup from old state. */ 1851da177e4SLinus Torvalds if (old) { 1861da177e4SLinus Torvalds switch (old->type) { 1871da177e4SLinus Torvalds case ACPI_STATE_C3: 1881da177e4SLinus Torvalds /* Disable bus master reload */ 18902df8b93SVenkatesh Pallipadi if (new->type != ACPI_STATE_C3 && pr->flags.bm_check) 1904be44fcdSLen Brown acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0, 1914be44fcdSLen Brown ACPI_MTX_DO_NOT_LOCK); 1921da177e4SLinus Torvalds break; 1931da177e4SLinus Torvalds } 1941da177e4SLinus Torvalds } 1951da177e4SLinus Torvalds 1961da177e4SLinus Torvalds /* Prepare to use new state. */ 1971da177e4SLinus Torvalds switch (new->type) { 1981da177e4SLinus Torvalds case ACPI_STATE_C3: 1991da177e4SLinus Torvalds /* Enable bus master reload */ 20002df8b93SVenkatesh Pallipadi if (old->type != ACPI_STATE_C3 && pr->flags.bm_check) 2014be44fcdSLen Brown acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 1, 2024be44fcdSLen Brown ACPI_MTX_DO_NOT_LOCK); 2031da177e4SLinus Torvalds break; 2041da177e4SLinus Torvalds } 2051da177e4SLinus Torvalds 2061da177e4SLinus Torvalds pr->power.state = new; 2071da177e4SLinus Torvalds 2081da177e4SLinus Torvalds return; 2091da177e4SLinus Torvalds } 2101da177e4SLinus Torvalds 21164c7c8f8SNick Piggin static void acpi_safe_halt(void) 21264c7c8f8SNick Piggin { 213495ab9c0SAndi Kleen current_thread_info()->status &= ~TS_POLLING; 21464c7c8f8SNick Piggin smp_mb__after_clear_bit(); 21564c7c8f8SNick Piggin if (!need_resched()) 21664c7c8f8SNick Piggin safe_halt(); 217495ab9c0SAndi Kleen current_thread_info()->status |= TS_POLLING; 21864c7c8f8SNick Piggin } 21964c7c8f8SNick Piggin 22002df8b93SVenkatesh Pallipadi static atomic_t c3_cpu_count; 22102df8b93SVenkatesh Pallipadi 2221da177e4SLinus Torvalds static void acpi_processor_idle(void) 2231da177e4SLinus Torvalds { 2241da177e4SLinus Torvalds struct acpi_processor *pr = NULL; 2251da177e4SLinus Torvalds struct acpi_processor_cx *cx = NULL; 2261da177e4SLinus Torvalds struct acpi_processor_cx *next_state = NULL; 2271da177e4SLinus Torvalds int sleep_ticks = 0; 2281da177e4SLinus Torvalds u32 t1, t2 = 0; 2291da177e4SLinus Torvalds 23064c7c8f8SNick Piggin pr = processors[smp_processor_id()]; 2311da177e4SLinus Torvalds if (!pr) 2321da177e4SLinus Torvalds return; 2331da177e4SLinus Torvalds 2341da177e4SLinus Torvalds /* 2351da177e4SLinus Torvalds * Interrupts must be disabled during bus mastering calculations and 2361da177e4SLinus Torvalds * for C2/C3 transitions. 2371da177e4SLinus Torvalds */ 2381da177e4SLinus Torvalds local_irq_disable(); 2391da177e4SLinus Torvalds 2401da177e4SLinus Torvalds /* 2411da177e4SLinus Torvalds * Check whether we truly need to go idle, or should 2421da177e4SLinus Torvalds * reschedule: 2431da177e4SLinus Torvalds */ 2441da177e4SLinus Torvalds if (unlikely(need_resched())) { 2451da177e4SLinus Torvalds local_irq_enable(); 2461da177e4SLinus Torvalds return; 2471da177e4SLinus Torvalds } 2481da177e4SLinus Torvalds 2491da177e4SLinus Torvalds cx = pr->power.state; 25064c7c8f8SNick Piggin if (!cx) { 25164c7c8f8SNick Piggin if (pm_idle_save) 25264c7c8f8SNick Piggin pm_idle_save(); 25364c7c8f8SNick Piggin else 25464c7c8f8SNick Piggin acpi_safe_halt(); 25564c7c8f8SNick Piggin return; 25664c7c8f8SNick Piggin } 2571da177e4SLinus Torvalds 2581da177e4SLinus Torvalds /* 2591da177e4SLinus Torvalds * Check BM Activity 2601da177e4SLinus Torvalds * ----------------- 2611da177e4SLinus Torvalds * Check for bus mastering activity (if required), record, and check 2621da177e4SLinus Torvalds * for demotion. 2631da177e4SLinus Torvalds */ 2641da177e4SLinus Torvalds if (pr->flags.bm_check) { 2651da177e4SLinus Torvalds u32 bm_status = 0; 2661da177e4SLinus Torvalds unsigned long diff = jiffies - pr->power.bm_check_timestamp; 2671da177e4SLinus Torvalds 268c5ab81caSDominik Brodowski if (diff > 31) 269c5ab81caSDominik Brodowski diff = 31; 2701da177e4SLinus Torvalds 271c5ab81caSDominik Brodowski pr->power.bm_activity <<= diff; 2721da177e4SLinus Torvalds 2731da177e4SLinus Torvalds acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS, 2741da177e4SLinus Torvalds &bm_status, ACPI_MTX_DO_NOT_LOCK); 2751da177e4SLinus Torvalds if (bm_status) { 276c5ab81caSDominik Brodowski pr->power.bm_activity |= 0x1; 2771da177e4SLinus Torvalds acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS, 2781da177e4SLinus Torvalds 1, ACPI_MTX_DO_NOT_LOCK); 2791da177e4SLinus Torvalds } 2801da177e4SLinus Torvalds /* 2811da177e4SLinus Torvalds * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect 2821da177e4SLinus Torvalds * the true state of bus mastering activity; forcing us to 2831da177e4SLinus Torvalds * manually check the BMIDEA bit of each IDE channel. 2841da177e4SLinus Torvalds */ 2851da177e4SLinus Torvalds else if (errata.piix4.bmisx) { 2861da177e4SLinus Torvalds if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01) 2871da177e4SLinus Torvalds || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01)) 288c5ab81caSDominik Brodowski pr->power.bm_activity |= 0x1; 2891da177e4SLinus Torvalds } 2901da177e4SLinus Torvalds 2911da177e4SLinus Torvalds pr->power.bm_check_timestamp = jiffies; 2921da177e4SLinus Torvalds 2931da177e4SLinus Torvalds /* 294c4a001b1SDominik Brodowski * If bus mastering is or was active this jiffy, demote 2951da177e4SLinus Torvalds * to avoid a faulty transition. Note that the processor 2961da177e4SLinus Torvalds * won't enter a low-power state during this call (to this 297c4a001b1SDominik Brodowski * function) but should upon the next. 2981da177e4SLinus Torvalds * 2991da177e4SLinus Torvalds * TBD: A better policy might be to fallback to the demotion 3001da177e4SLinus Torvalds * state (use it for this quantum only) istead of 3011da177e4SLinus Torvalds * demoting -- and rely on duration as our sole demotion 3021da177e4SLinus Torvalds * qualification. This may, however, introduce DMA 3031da177e4SLinus Torvalds * issues (e.g. floppy DMA transfer overrun/underrun). 3041da177e4SLinus Torvalds */ 305c4a001b1SDominik Brodowski if ((pr->power.bm_activity & 0x1) && 306c4a001b1SDominik Brodowski cx->demotion.threshold.bm) { 3071da177e4SLinus Torvalds local_irq_enable(); 3081da177e4SLinus Torvalds next_state = cx->demotion.state; 3091da177e4SLinus Torvalds goto end; 3101da177e4SLinus Torvalds } 3111da177e4SLinus Torvalds } 3121da177e4SLinus Torvalds 3134c033552SVenkatesh Pallipadi #ifdef CONFIG_HOTPLUG_CPU 3144c033552SVenkatesh Pallipadi /* 3154c033552SVenkatesh Pallipadi * Check for P_LVL2_UP flag before entering C2 and above on 3164c033552SVenkatesh Pallipadi * an SMP system. We do it here instead of doing it at _CST/P_LVL 3174c033552SVenkatesh Pallipadi * detection phase, to work cleanly with logical CPU hotplug. 3184c033552SVenkatesh Pallipadi */ 3194c033552SVenkatesh Pallipadi if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) && 3201e483969SDavid Shaohua Li !pr->flags.has_cst && !acpi_fadt.plvl2_up) 3211e483969SDavid Shaohua Li cx = &pr->power.states[ACPI_STATE_C1]; 3224c033552SVenkatesh Pallipadi #endif 3231e483969SDavid Shaohua Li 3241da177e4SLinus Torvalds /* 3251da177e4SLinus Torvalds * Sleep: 3261da177e4SLinus Torvalds * ------ 3271da177e4SLinus Torvalds * Invoke the current Cx state to put the processor to sleep. 3281da177e4SLinus Torvalds */ 3292a298a35SNick Piggin if (cx->type == ACPI_STATE_C2 || cx->type == ACPI_STATE_C3) { 330495ab9c0SAndi Kleen current_thread_info()->status &= ~TS_POLLING; 3312a298a35SNick Piggin smp_mb__after_clear_bit(); 3322a298a35SNick Piggin if (need_resched()) { 333495ab9c0SAndi Kleen current_thread_info()->status |= TS_POLLING; 334af2eb17bSLinus Torvalds local_irq_enable(); 3352a298a35SNick Piggin return; 3362a298a35SNick Piggin } 3372a298a35SNick Piggin } 3382a298a35SNick Piggin 3391da177e4SLinus Torvalds switch (cx->type) { 3401da177e4SLinus Torvalds 3411da177e4SLinus Torvalds case ACPI_STATE_C1: 3421da177e4SLinus Torvalds /* 3431da177e4SLinus Torvalds * Invoke C1. 3441da177e4SLinus Torvalds * Use the appropriate idle routine, the one that would 3451da177e4SLinus Torvalds * be used without acpi C-states. 3461da177e4SLinus Torvalds */ 3471da177e4SLinus Torvalds if (pm_idle_save) 3481da177e4SLinus Torvalds pm_idle_save(); 3491da177e4SLinus Torvalds else 35064c7c8f8SNick Piggin acpi_safe_halt(); 35164c7c8f8SNick Piggin 3521da177e4SLinus Torvalds /* 3531da177e4SLinus Torvalds * TBD: Can't get time duration while in C1, as resumes 3541da177e4SLinus Torvalds * go to an ISR rather than here. Need to instrument 3551da177e4SLinus Torvalds * base interrupt handler. 3561da177e4SLinus Torvalds */ 3571da177e4SLinus Torvalds sleep_ticks = 0xFFFFFFFF; 3581da177e4SLinus Torvalds break; 3591da177e4SLinus Torvalds 3601da177e4SLinus Torvalds case ACPI_STATE_C2: 3611da177e4SLinus Torvalds /* Get start time (ticks) */ 3621da177e4SLinus Torvalds t1 = inl(acpi_fadt.xpm_tmr_blk.address); 3631da177e4SLinus Torvalds /* Invoke C2 */ 3641da177e4SLinus Torvalds inb(cx->address); 365b488f021SAndreas Mohr /* Dummy wait op - must do something useless after P_LVL2 read 366b488f021SAndreas Mohr because chipsets cannot guarantee that STPCLK# signal 367b488f021SAndreas Mohr gets asserted in time to freeze execution properly. */ 3681da177e4SLinus Torvalds t2 = inl(acpi_fadt.xpm_tmr_blk.address); 3691da177e4SLinus Torvalds /* Get end time (ticks) */ 3701da177e4SLinus Torvalds t2 = inl(acpi_fadt.xpm_tmr_blk.address); 371539eb11eSjohn stultz 372539eb11eSjohn stultz #ifdef CONFIG_GENERIC_TIME 373539eb11eSjohn stultz /* TSC halts in C2, so notify users */ 374539eb11eSjohn stultz mark_tsc_unstable(); 375539eb11eSjohn stultz #endif 3761da177e4SLinus Torvalds /* Re-enable interrupts */ 3771da177e4SLinus Torvalds local_irq_enable(); 378495ab9c0SAndi Kleen current_thread_info()->status |= TS_POLLING; 3791da177e4SLinus Torvalds /* Compute time (ticks) that we were actually asleep */ 3804be44fcdSLen Brown sleep_ticks = 3814be44fcdSLen Brown ticks_elapsed(t1, t2) - cx->latency_ticks - C2_OVERHEAD; 3821da177e4SLinus Torvalds break; 3831da177e4SLinus Torvalds 3841da177e4SLinus Torvalds case ACPI_STATE_C3: 38502df8b93SVenkatesh Pallipadi 38602df8b93SVenkatesh Pallipadi if (pr->flags.bm_check) { 38702df8b93SVenkatesh Pallipadi if (atomic_inc_return(&c3_cpu_count) == 38802df8b93SVenkatesh Pallipadi num_online_cpus()) { 38902df8b93SVenkatesh Pallipadi /* 39002df8b93SVenkatesh Pallipadi * All CPUs are trying to go to C3 39102df8b93SVenkatesh Pallipadi * Disable bus master arbitration 39202df8b93SVenkatesh Pallipadi */ 39302df8b93SVenkatesh Pallipadi acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1, 39402df8b93SVenkatesh Pallipadi ACPI_MTX_DO_NOT_LOCK); 39502df8b93SVenkatesh Pallipadi } 39602df8b93SVenkatesh Pallipadi } else { 39702df8b93SVenkatesh Pallipadi /* SMP with no shared cache... Invalidate cache */ 39802df8b93SVenkatesh Pallipadi ACPI_FLUSH_CPU_CACHE(); 39902df8b93SVenkatesh Pallipadi } 40002df8b93SVenkatesh Pallipadi 4011da177e4SLinus Torvalds /* Get start time (ticks) */ 4021da177e4SLinus Torvalds t1 = inl(acpi_fadt.xpm_tmr_blk.address); 4031da177e4SLinus Torvalds /* Invoke C3 */ 4041da177e4SLinus Torvalds inb(cx->address); 405b488f021SAndreas Mohr /* Dummy wait op (see above) */ 4061da177e4SLinus Torvalds t2 = inl(acpi_fadt.xpm_tmr_blk.address); 4071da177e4SLinus Torvalds /* Get end time (ticks) */ 4081da177e4SLinus Torvalds t2 = inl(acpi_fadt.xpm_tmr_blk.address); 40902df8b93SVenkatesh Pallipadi if (pr->flags.bm_check) { 4101da177e4SLinus Torvalds /* Enable bus master arbitration */ 41102df8b93SVenkatesh Pallipadi atomic_dec(&c3_cpu_count); 4124be44fcdSLen Brown acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0, 4134be44fcdSLen Brown ACPI_MTX_DO_NOT_LOCK); 41402df8b93SVenkatesh Pallipadi } 41502df8b93SVenkatesh Pallipadi 416539eb11eSjohn stultz #ifdef CONFIG_GENERIC_TIME 417539eb11eSjohn stultz /* TSC halts in C3, so notify users */ 418539eb11eSjohn stultz mark_tsc_unstable(); 419539eb11eSjohn stultz #endif 4201da177e4SLinus Torvalds /* Re-enable interrupts */ 4211da177e4SLinus Torvalds local_irq_enable(); 422495ab9c0SAndi Kleen current_thread_info()->status |= TS_POLLING; 4231da177e4SLinus Torvalds /* Compute time (ticks) that we were actually asleep */ 4244be44fcdSLen Brown sleep_ticks = 4254be44fcdSLen Brown ticks_elapsed(t1, t2) - cx->latency_ticks - C3_OVERHEAD; 4261da177e4SLinus Torvalds break; 4271da177e4SLinus Torvalds 4281da177e4SLinus Torvalds default: 4291da177e4SLinus Torvalds local_irq_enable(); 4301da177e4SLinus Torvalds return; 4311da177e4SLinus Torvalds } 432a3c6598fSDominik Brodowski cx->usage++; 433a3c6598fSDominik Brodowski if ((cx->type != ACPI_STATE_C1) && (sleep_ticks > 0)) 434a3c6598fSDominik Brodowski cx->time += sleep_ticks; 4351da177e4SLinus Torvalds 4361da177e4SLinus Torvalds next_state = pr->power.state; 4371da177e4SLinus Torvalds 4381e483969SDavid Shaohua Li #ifdef CONFIG_HOTPLUG_CPU 4391e483969SDavid Shaohua Li /* Don't do promotion/demotion */ 4401e483969SDavid Shaohua Li if ((cx->type == ACPI_STATE_C1) && (num_online_cpus() > 1) && 4411e483969SDavid Shaohua Li !pr->flags.has_cst && !acpi_fadt.plvl2_up) { 4421e483969SDavid Shaohua Li next_state = cx; 4431e483969SDavid Shaohua Li goto end; 4441e483969SDavid Shaohua Li } 4451e483969SDavid Shaohua Li #endif 4461e483969SDavid Shaohua Li 4471da177e4SLinus Torvalds /* 4481da177e4SLinus Torvalds * Promotion? 4491da177e4SLinus Torvalds * ---------- 4501da177e4SLinus Torvalds * Track the number of longs (time asleep is greater than threshold) 4511da177e4SLinus Torvalds * and promote when the count threshold is reached. Note that bus 4521da177e4SLinus Torvalds * mastering activity may prevent promotions. 4531da177e4SLinus Torvalds * Do not promote above max_cstate. 4541da177e4SLinus Torvalds */ 4551da177e4SLinus Torvalds if (cx->promotion.state && 4561da177e4SLinus Torvalds ((cx->promotion.state - pr->power.states) <= max_cstate)) { 4575c87579eSArjan van de Ven if (sleep_ticks > cx->promotion.threshold.ticks && 4585c87579eSArjan van de Ven cx->promotion.state->latency <= system_latency_constraint()) { 4591da177e4SLinus Torvalds cx->promotion.count++; 4601da177e4SLinus Torvalds cx->demotion.count = 0; 4614be44fcdSLen Brown if (cx->promotion.count >= 4624be44fcdSLen Brown cx->promotion.threshold.count) { 4631da177e4SLinus Torvalds if (pr->flags.bm_check) { 4644be44fcdSLen Brown if (! 4654be44fcdSLen Brown (pr->power.bm_activity & cx-> 4664be44fcdSLen Brown promotion.threshold.bm)) { 4674be44fcdSLen Brown next_state = 4684be44fcdSLen Brown cx->promotion.state; 4691da177e4SLinus Torvalds goto end; 4701da177e4SLinus Torvalds } 4714be44fcdSLen Brown } else { 4721da177e4SLinus Torvalds next_state = cx->promotion.state; 4731da177e4SLinus Torvalds goto end; 4741da177e4SLinus Torvalds } 4751da177e4SLinus Torvalds } 4761da177e4SLinus Torvalds } 4771da177e4SLinus Torvalds } 4781da177e4SLinus Torvalds 4791da177e4SLinus Torvalds /* 4801da177e4SLinus Torvalds * Demotion? 4811da177e4SLinus Torvalds * --------- 4821da177e4SLinus Torvalds * Track the number of shorts (time asleep is less than time threshold) 4831da177e4SLinus Torvalds * and demote when the usage threshold is reached. 4841da177e4SLinus Torvalds */ 4851da177e4SLinus Torvalds if (cx->demotion.state) { 4861da177e4SLinus Torvalds if (sleep_ticks < cx->demotion.threshold.ticks) { 4871da177e4SLinus Torvalds cx->demotion.count++; 4881da177e4SLinus Torvalds cx->promotion.count = 0; 4891da177e4SLinus Torvalds if (cx->demotion.count >= cx->demotion.threshold.count) { 4901da177e4SLinus Torvalds next_state = cx->demotion.state; 4911da177e4SLinus Torvalds goto end; 4921da177e4SLinus Torvalds } 4931da177e4SLinus Torvalds } 4941da177e4SLinus Torvalds } 4951da177e4SLinus Torvalds 4961da177e4SLinus Torvalds end: 4971da177e4SLinus Torvalds /* 4981da177e4SLinus Torvalds * Demote if current state exceeds max_cstate 4995c87579eSArjan van de Ven * or if the latency of the current state is unacceptable 5001da177e4SLinus Torvalds */ 5015c87579eSArjan van de Ven if ((pr->power.state - pr->power.states) > max_cstate || 5025c87579eSArjan van de Ven pr->power.state->latency > system_latency_constraint()) { 5031da177e4SLinus Torvalds if (cx->demotion.state) 5041da177e4SLinus Torvalds next_state = cx->demotion.state; 5051da177e4SLinus Torvalds } 5061da177e4SLinus Torvalds 5071da177e4SLinus Torvalds /* 5081da177e4SLinus Torvalds * New Cx State? 5091da177e4SLinus Torvalds * ------------- 5101da177e4SLinus Torvalds * If we're going to start using a new Cx state we must clean up 5111da177e4SLinus Torvalds * from the previous and prepare to use the new. 5121da177e4SLinus Torvalds */ 5131da177e4SLinus Torvalds if (next_state != pr->power.state) 5141da177e4SLinus Torvalds acpi_processor_power_activate(pr, next_state); 5151da177e4SLinus Torvalds } 5161da177e4SLinus Torvalds 5174be44fcdSLen Brown static int acpi_processor_set_power_policy(struct acpi_processor *pr) 5181da177e4SLinus Torvalds { 5191da177e4SLinus Torvalds unsigned int i; 5201da177e4SLinus Torvalds unsigned int state_is_set = 0; 5211da177e4SLinus Torvalds struct acpi_processor_cx *lower = NULL; 5221da177e4SLinus Torvalds struct acpi_processor_cx *higher = NULL; 5231da177e4SLinus Torvalds struct acpi_processor_cx *cx; 5241da177e4SLinus Torvalds 5251da177e4SLinus Torvalds 5261da177e4SLinus Torvalds if (!pr) 527d550d98dSPatrick Mochel return -EINVAL; 5281da177e4SLinus Torvalds 5291da177e4SLinus Torvalds /* 5301da177e4SLinus Torvalds * This function sets the default Cx state policy (OS idle handler). 5311da177e4SLinus Torvalds * Our scheme is to promote quickly to C2 but more conservatively 5321da177e4SLinus Torvalds * to C3. We're favoring C2 for its characteristics of low latency 5331da177e4SLinus Torvalds * (quick response), good power savings, and ability to allow bus 5341da177e4SLinus Torvalds * mastering activity. Note that the Cx state policy is completely 5351da177e4SLinus Torvalds * customizable and can be altered dynamically. 5361da177e4SLinus Torvalds */ 5371da177e4SLinus Torvalds 5381da177e4SLinus Torvalds /* startup state */ 5391da177e4SLinus Torvalds for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) { 5401da177e4SLinus Torvalds cx = &pr->power.states[i]; 5411da177e4SLinus Torvalds if (!cx->valid) 5421da177e4SLinus Torvalds continue; 5431da177e4SLinus Torvalds 5441da177e4SLinus Torvalds if (!state_is_set) 5451da177e4SLinus Torvalds pr->power.state = cx; 5461da177e4SLinus Torvalds state_is_set++; 5471da177e4SLinus Torvalds break; 5481da177e4SLinus Torvalds } 5491da177e4SLinus Torvalds 5501da177e4SLinus Torvalds if (!state_is_set) 551d550d98dSPatrick Mochel return -ENODEV; 5521da177e4SLinus Torvalds 5531da177e4SLinus Torvalds /* demotion */ 5541da177e4SLinus Torvalds for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) { 5551da177e4SLinus Torvalds cx = &pr->power.states[i]; 5561da177e4SLinus Torvalds if (!cx->valid) 5571da177e4SLinus Torvalds continue; 5581da177e4SLinus Torvalds 5591da177e4SLinus Torvalds if (lower) { 5601da177e4SLinus Torvalds cx->demotion.state = lower; 5611da177e4SLinus Torvalds cx->demotion.threshold.ticks = cx->latency_ticks; 5621da177e4SLinus Torvalds cx->demotion.threshold.count = 1; 5631da177e4SLinus Torvalds if (cx->type == ACPI_STATE_C3) 5641da177e4SLinus Torvalds cx->demotion.threshold.bm = bm_history; 5651da177e4SLinus Torvalds } 5661da177e4SLinus Torvalds 5671da177e4SLinus Torvalds lower = cx; 5681da177e4SLinus Torvalds } 5691da177e4SLinus Torvalds 5701da177e4SLinus Torvalds /* promotion */ 5711da177e4SLinus Torvalds for (i = (ACPI_PROCESSOR_MAX_POWER - 1); i > 0; i--) { 5721da177e4SLinus Torvalds cx = &pr->power.states[i]; 5731da177e4SLinus Torvalds if (!cx->valid) 5741da177e4SLinus Torvalds continue; 5751da177e4SLinus Torvalds 5761da177e4SLinus Torvalds if (higher) { 5771da177e4SLinus Torvalds cx->promotion.state = higher; 5781da177e4SLinus Torvalds cx->promotion.threshold.ticks = cx->latency_ticks; 5791da177e4SLinus Torvalds if (cx->type >= ACPI_STATE_C2) 5801da177e4SLinus Torvalds cx->promotion.threshold.count = 4; 5811da177e4SLinus Torvalds else 5821da177e4SLinus Torvalds cx->promotion.threshold.count = 10; 5831da177e4SLinus Torvalds if (higher->type == ACPI_STATE_C3) 5841da177e4SLinus Torvalds cx->promotion.threshold.bm = bm_history; 5851da177e4SLinus Torvalds } 5861da177e4SLinus Torvalds 5871da177e4SLinus Torvalds higher = cx; 5881da177e4SLinus Torvalds } 5891da177e4SLinus Torvalds 590d550d98dSPatrick Mochel return 0; 5911da177e4SLinus Torvalds } 5921da177e4SLinus Torvalds 5931da177e4SLinus Torvalds static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr) 5941da177e4SLinus Torvalds { 5951da177e4SLinus Torvalds 5961da177e4SLinus Torvalds if (!pr) 597d550d98dSPatrick Mochel return -EINVAL; 5981da177e4SLinus Torvalds 5991da177e4SLinus Torvalds if (!pr->pblk) 600d550d98dSPatrick Mochel return -ENODEV; 6011da177e4SLinus Torvalds 6021da177e4SLinus Torvalds /* if info is obtained from pblk/fadt, type equals state */ 6031da177e4SLinus Torvalds pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2; 6041da177e4SLinus Torvalds pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3; 6051da177e4SLinus Torvalds 6064c033552SVenkatesh Pallipadi #ifndef CONFIG_HOTPLUG_CPU 6074c033552SVenkatesh Pallipadi /* 6084c033552SVenkatesh Pallipadi * Check for P_LVL2_UP flag before entering C2 and above on 6094c033552SVenkatesh Pallipadi * an SMP system. 6104c033552SVenkatesh Pallipadi */ 6111e483969SDavid Shaohua Li if ((num_online_cpus() > 1) && !acpi_fadt.plvl2_up) 612d550d98dSPatrick Mochel return -ENODEV; 6134c033552SVenkatesh Pallipadi #endif 6144c033552SVenkatesh Pallipadi 6151da177e4SLinus Torvalds /* determine C2 and C3 address from pblk */ 6161da177e4SLinus Torvalds pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4; 6171da177e4SLinus Torvalds pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5; 6181da177e4SLinus Torvalds 6191da177e4SLinus Torvalds /* determine latencies from FADT */ 6201da177e4SLinus Torvalds pr->power.states[ACPI_STATE_C2].latency = acpi_fadt.plvl2_lat; 6211da177e4SLinus Torvalds pr->power.states[ACPI_STATE_C3].latency = acpi_fadt.plvl3_lat; 6221da177e4SLinus Torvalds 6231da177e4SLinus Torvalds ACPI_DEBUG_PRINT((ACPI_DB_INFO, 6241da177e4SLinus Torvalds "lvl2[0x%08x] lvl3[0x%08x]\n", 6251da177e4SLinus Torvalds pr->power.states[ACPI_STATE_C2].address, 6261da177e4SLinus Torvalds pr->power.states[ACPI_STATE_C3].address)); 6271da177e4SLinus Torvalds 628d550d98dSPatrick Mochel return 0; 6291da177e4SLinus Torvalds } 6301da177e4SLinus Torvalds 631acf05f4bSVenkatesh Pallipadi static int acpi_processor_get_power_info_default_c1(struct acpi_processor *pr) 632acf05f4bSVenkatesh Pallipadi { 633acf05f4bSVenkatesh Pallipadi 634cf824788SJanosch Machowinski /* Zero initialize all the C-states info. */ 6352203d6edSLinus Torvalds memset(pr->power.states, 0, sizeof(pr->power.states)); 636acf05f4bSVenkatesh Pallipadi 637cf824788SJanosch Machowinski /* set the first C-State to C1 */ 638acf05f4bSVenkatesh Pallipadi pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1; 639acf05f4bSVenkatesh Pallipadi 640acf05f4bSVenkatesh Pallipadi /* the C0 state only exists as a filler in our array, 641acf05f4bSVenkatesh Pallipadi * and all processors need to support C1 */ 642acf05f4bSVenkatesh Pallipadi pr->power.states[ACPI_STATE_C0].valid = 1; 643acf05f4bSVenkatesh Pallipadi pr->power.states[ACPI_STATE_C1].valid = 1; 644acf05f4bSVenkatesh Pallipadi 645d550d98dSPatrick Mochel return 0; 646acf05f4bSVenkatesh Pallipadi } 647acf05f4bSVenkatesh Pallipadi 6481da177e4SLinus Torvalds static int acpi_processor_get_power_info_cst(struct acpi_processor *pr) 6491da177e4SLinus Torvalds { 6501da177e4SLinus Torvalds acpi_status status = 0; 6511da177e4SLinus Torvalds acpi_integer count; 652cf824788SJanosch Machowinski int current_count; 6531da177e4SLinus Torvalds int i; 6541da177e4SLinus Torvalds struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 6551da177e4SLinus Torvalds union acpi_object *cst; 6561da177e4SLinus Torvalds 6571da177e4SLinus Torvalds 6581da177e4SLinus Torvalds if (nocst) 659d550d98dSPatrick Mochel return -ENODEV; 6601da177e4SLinus Torvalds 661cf824788SJanosch Machowinski current_count = 1; 662cf824788SJanosch Machowinski 663cf824788SJanosch Machowinski /* Zero initialize C2 onwards and prepare for fresh CST lookup */ 664cf824788SJanosch Machowinski for (i = 2; i < ACPI_PROCESSOR_MAX_POWER; i++) 6650b6b2f08SVenkatesh Pallipadi memset(&(pr->power.states[i]), 0, 6660b6b2f08SVenkatesh Pallipadi sizeof(struct acpi_processor_cx)); 6671da177e4SLinus Torvalds 6681da177e4SLinus Torvalds status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer); 6691da177e4SLinus Torvalds if (ACPI_FAILURE(status)) { 6701da177e4SLinus Torvalds ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n")); 671d550d98dSPatrick Mochel return -ENODEV; 6721da177e4SLinus Torvalds } 6731da177e4SLinus Torvalds 6741da177e4SLinus Torvalds cst = (union acpi_object *)buffer.pointer; 6751da177e4SLinus Torvalds 6761da177e4SLinus Torvalds /* There must be at least 2 elements */ 6771da177e4SLinus Torvalds if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) { 6786468463aSLen Brown printk(KERN_ERR PREFIX "not enough elements in _CST\n"); 6791da177e4SLinus Torvalds status = -EFAULT; 6801da177e4SLinus Torvalds goto end; 6811da177e4SLinus Torvalds } 6821da177e4SLinus Torvalds 6831da177e4SLinus Torvalds count = cst->package.elements[0].integer.value; 6841da177e4SLinus Torvalds 6851da177e4SLinus Torvalds /* Validate number of power states. */ 6861da177e4SLinus Torvalds if (count < 1 || count != cst->package.count - 1) { 6876468463aSLen Brown printk(KERN_ERR PREFIX "count given by _CST is not valid\n"); 6881da177e4SLinus Torvalds status = -EFAULT; 6891da177e4SLinus Torvalds goto end; 6901da177e4SLinus Torvalds } 6911da177e4SLinus Torvalds 6921da177e4SLinus Torvalds /* Tell driver that at least _CST is supported. */ 6931da177e4SLinus Torvalds pr->flags.has_cst = 1; 6941da177e4SLinus Torvalds 6951da177e4SLinus Torvalds for (i = 1; i <= count; i++) { 6961da177e4SLinus Torvalds union acpi_object *element; 6971da177e4SLinus Torvalds union acpi_object *obj; 6981da177e4SLinus Torvalds struct acpi_power_register *reg; 6991da177e4SLinus Torvalds struct acpi_processor_cx cx; 7001da177e4SLinus Torvalds 7011da177e4SLinus Torvalds memset(&cx, 0, sizeof(cx)); 7021da177e4SLinus Torvalds 7031da177e4SLinus Torvalds element = (union acpi_object *)&(cst->package.elements[i]); 7041da177e4SLinus Torvalds if (element->type != ACPI_TYPE_PACKAGE) 7051da177e4SLinus Torvalds continue; 7061da177e4SLinus Torvalds 7071da177e4SLinus Torvalds if (element->package.count != 4) 7081da177e4SLinus Torvalds continue; 7091da177e4SLinus Torvalds 7101da177e4SLinus Torvalds obj = (union acpi_object *)&(element->package.elements[0]); 7111da177e4SLinus Torvalds 7121da177e4SLinus Torvalds if (obj->type != ACPI_TYPE_BUFFER) 7131da177e4SLinus Torvalds continue; 7141da177e4SLinus Torvalds 7151da177e4SLinus Torvalds reg = (struct acpi_power_register *)obj->buffer.pointer; 7161da177e4SLinus Torvalds 7171da177e4SLinus Torvalds if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO && 7181da177e4SLinus Torvalds (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)) 7191da177e4SLinus Torvalds continue; 7201da177e4SLinus Torvalds 7211da177e4SLinus Torvalds cx.address = (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) ? 7221da177e4SLinus Torvalds 0 : reg->address; 7231da177e4SLinus Torvalds 7241da177e4SLinus Torvalds /* There should be an easy way to extract an integer... */ 7251da177e4SLinus Torvalds obj = (union acpi_object *)&(element->package.elements[1]); 7261da177e4SLinus Torvalds if (obj->type != ACPI_TYPE_INTEGER) 7271da177e4SLinus Torvalds continue; 7281da177e4SLinus Torvalds 7291da177e4SLinus Torvalds cx.type = obj->integer.value; 7301da177e4SLinus Torvalds 7311da177e4SLinus Torvalds if ((cx.type != ACPI_STATE_C1) && 7321da177e4SLinus Torvalds (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO)) 7331da177e4SLinus Torvalds continue; 7341da177e4SLinus Torvalds 735cf824788SJanosch Machowinski if ((cx.type < ACPI_STATE_C2) || (cx.type > ACPI_STATE_C3)) 7361da177e4SLinus Torvalds continue; 7371da177e4SLinus Torvalds 7381da177e4SLinus Torvalds obj = (union acpi_object *)&(element->package.elements[2]); 7391da177e4SLinus Torvalds if (obj->type != ACPI_TYPE_INTEGER) 7401da177e4SLinus Torvalds continue; 7411da177e4SLinus Torvalds 7421da177e4SLinus Torvalds cx.latency = obj->integer.value; 7431da177e4SLinus Torvalds 7441da177e4SLinus Torvalds obj = (union acpi_object *)&(element->package.elements[3]); 7451da177e4SLinus Torvalds if (obj->type != ACPI_TYPE_INTEGER) 7461da177e4SLinus Torvalds continue; 7471da177e4SLinus Torvalds 7481da177e4SLinus Torvalds cx.power = obj->integer.value; 7491da177e4SLinus Torvalds 750cf824788SJanosch Machowinski current_count++; 751cf824788SJanosch Machowinski memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx)); 752cf824788SJanosch Machowinski 753cf824788SJanosch Machowinski /* 754cf824788SJanosch Machowinski * We support total ACPI_PROCESSOR_MAX_POWER - 1 755cf824788SJanosch Machowinski * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1) 756cf824788SJanosch Machowinski */ 757cf824788SJanosch Machowinski if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) { 758cf824788SJanosch Machowinski printk(KERN_WARNING 759cf824788SJanosch Machowinski "Limiting number of power states to max (%d)\n", 760cf824788SJanosch Machowinski ACPI_PROCESSOR_MAX_POWER); 761cf824788SJanosch Machowinski printk(KERN_WARNING 762cf824788SJanosch Machowinski "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n"); 763cf824788SJanosch Machowinski break; 764cf824788SJanosch Machowinski } 7651da177e4SLinus Torvalds } 7661da177e4SLinus Torvalds 7674be44fcdSLen Brown ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n", 768cf824788SJanosch Machowinski current_count)); 7691da177e4SLinus Torvalds 7701da177e4SLinus Torvalds /* Validate number of power states discovered */ 771cf824788SJanosch Machowinski if (current_count < 2) 7726d93c648SVenkatesh Pallipadi status = -EFAULT; 7731da177e4SLinus Torvalds 7741da177e4SLinus Torvalds end: 77502438d87SLen Brown kfree(buffer.pointer); 7761da177e4SLinus Torvalds 777d550d98dSPatrick Mochel return status; 7781da177e4SLinus Torvalds } 7791da177e4SLinus Torvalds 7801da177e4SLinus Torvalds static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx) 7811da177e4SLinus Torvalds { 7821da177e4SLinus Torvalds 7831da177e4SLinus Torvalds if (!cx->address) 784d550d98dSPatrick Mochel return; 7851da177e4SLinus Torvalds 7861da177e4SLinus Torvalds /* 7871da177e4SLinus Torvalds * C2 latency must be less than or equal to 100 7881da177e4SLinus Torvalds * microseconds. 7891da177e4SLinus Torvalds */ 7901da177e4SLinus Torvalds else if (cx->latency > ACPI_PROCESSOR_MAX_C2_LATENCY) { 7911da177e4SLinus Torvalds ACPI_DEBUG_PRINT((ACPI_DB_INFO, 7924be44fcdSLen Brown "latency too large [%d]\n", cx->latency)); 793d550d98dSPatrick Mochel return; 7941da177e4SLinus Torvalds } 7951da177e4SLinus Torvalds 7961da177e4SLinus Torvalds /* 7971da177e4SLinus Torvalds * Otherwise we've met all of our C2 requirements. 7981da177e4SLinus Torvalds * Normalize the C2 latency to expidite policy 7991da177e4SLinus Torvalds */ 8001da177e4SLinus Torvalds cx->valid = 1; 8011da177e4SLinus Torvalds cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency); 8021da177e4SLinus Torvalds 803d550d98dSPatrick Mochel return; 8041da177e4SLinus Torvalds } 8051da177e4SLinus Torvalds 8064be44fcdSLen Brown static void acpi_processor_power_verify_c3(struct acpi_processor *pr, 8071da177e4SLinus Torvalds struct acpi_processor_cx *cx) 8081da177e4SLinus Torvalds { 80902df8b93SVenkatesh Pallipadi static int bm_check_flag; 81002df8b93SVenkatesh Pallipadi 8111da177e4SLinus Torvalds 8121da177e4SLinus Torvalds if (!cx->address) 813d550d98dSPatrick Mochel return; 8141da177e4SLinus Torvalds 8151da177e4SLinus Torvalds /* 8161da177e4SLinus Torvalds * C3 latency must be less than or equal to 1000 8171da177e4SLinus Torvalds * microseconds. 8181da177e4SLinus Torvalds */ 8191da177e4SLinus Torvalds else if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY) { 8201da177e4SLinus Torvalds ACPI_DEBUG_PRINT((ACPI_DB_INFO, 8214be44fcdSLen Brown "latency too large [%d]\n", cx->latency)); 822d550d98dSPatrick Mochel return; 8231da177e4SLinus Torvalds } 8241da177e4SLinus Torvalds 8251da177e4SLinus Torvalds /* 8261da177e4SLinus Torvalds * PIIX4 Erratum #18: We don't support C3 when Type-F (fast) 8271da177e4SLinus Torvalds * DMA transfers are used by any ISA device to avoid livelock. 8281da177e4SLinus Torvalds * Note that we could disable Type-F DMA (as recommended by 8291da177e4SLinus Torvalds * the erratum), but this is known to disrupt certain ISA 8301da177e4SLinus Torvalds * devices thus we take the conservative approach. 8311da177e4SLinus Torvalds */ 8321da177e4SLinus Torvalds else if (errata.piix4.fdma) { 8331da177e4SLinus Torvalds ACPI_DEBUG_PRINT((ACPI_DB_INFO, 8341da177e4SLinus Torvalds "C3 not supported on PIIX4 with Type-F DMA\n")); 835d550d98dSPatrick Mochel return; 8361da177e4SLinus Torvalds } 8371da177e4SLinus Torvalds 83802df8b93SVenkatesh Pallipadi /* All the logic here assumes flags.bm_check is same across all CPUs */ 83902df8b93SVenkatesh Pallipadi if (!bm_check_flag) { 84002df8b93SVenkatesh Pallipadi /* Determine whether bm_check is needed based on CPU */ 84102df8b93SVenkatesh Pallipadi acpi_processor_power_init_bm_check(&(pr->flags), pr->id); 84202df8b93SVenkatesh Pallipadi bm_check_flag = pr->flags.bm_check; 84302df8b93SVenkatesh Pallipadi } else { 84402df8b93SVenkatesh Pallipadi pr->flags.bm_check = bm_check_flag; 84502df8b93SVenkatesh Pallipadi } 84602df8b93SVenkatesh Pallipadi 84702df8b93SVenkatesh Pallipadi if (pr->flags.bm_check) { 84802df8b93SVenkatesh Pallipadi /* bus mastering control is necessary */ 84902df8b93SVenkatesh Pallipadi if (!pr->flags.bm_control) { 85002df8b93SVenkatesh Pallipadi ACPI_DEBUG_PRINT((ACPI_DB_INFO, 85102df8b93SVenkatesh Pallipadi "C3 support requires bus mastering control\n")); 852d550d98dSPatrick Mochel return; 85302df8b93SVenkatesh Pallipadi } 85402df8b93SVenkatesh Pallipadi } else { 85502df8b93SVenkatesh Pallipadi /* 85602df8b93SVenkatesh Pallipadi * WBINVD should be set in fadt, for C3 state to be 85702df8b93SVenkatesh Pallipadi * supported on when bm_check is not required. 85802df8b93SVenkatesh Pallipadi */ 85902df8b93SVenkatesh Pallipadi if (acpi_fadt.wb_invd != 1) { 86002df8b93SVenkatesh Pallipadi ACPI_DEBUG_PRINT((ACPI_DB_INFO, 86102df8b93SVenkatesh Pallipadi "Cache invalidation should work properly" 86202df8b93SVenkatesh Pallipadi " for C3 to be enabled on SMP systems\n")); 863d550d98dSPatrick Mochel return; 86402df8b93SVenkatesh Pallipadi } 86502df8b93SVenkatesh Pallipadi acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 86602df8b93SVenkatesh Pallipadi 0, ACPI_MTX_DO_NOT_LOCK); 86702df8b93SVenkatesh Pallipadi } 86802df8b93SVenkatesh Pallipadi 8691da177e4SLinus Torvalds /* 8701da177e4SLinus Torvalds * Otherwise we've met all of our C3 requirements. 8711da177e4SLinus Torvalds * Normalize the C3 latency to expidite policy. Enable 8721da177e4SLinus Torvalds * checking of bus mastering status (bm_check) so we can 8731da177e4SLinus Torvalds * use this in our C3 policy 8741da177e4SLinus Torvalds */ 8751da177e4SLinus Torvalds cx->valid = 1; 8761da177e4SLinus Torvalds cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency); 8771da177e4SLinus Torvalds 878d550d98dSPatrick Mochel return; 8791da177e4SLinus Torvalds } 8801da177e4SLinus Torvalds 8811da177e4SLinus Torvalds static int acpi_processor_power_verify(struct acpi_processor *pr) 8821da177e4SLinus Torvalds { 8831da177e4SLinus Torvalds unsigned int i; 8841da177e4SLinus Torvalds unsigned int working = 0; 8856eb0a0fdSVenkatesh Pallipadi 886bd663347SAndi Kleen #ifdef ARCH_APICTIMER_STOPS_ON_C3 8870b5c59a1SAndi Kleen int timer_broadcast = 0; 8880b5c59a1SAndi Kleen cpumask_t mask = cpumask_of_cpu(pr->id); 8896eb0a0fdSVenkatesh Pallipadi on_each_cpu(switch_ipi_to_APIC_timer, &mask, 1, 1); 8906eb0a0fdSVenkatesh Pallipadi #endif 8916eb0a0fdSVenkatesh Pallipadi 8921da177e4SLinus Torvalds for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) { 8931da177e4SLinus Torvalds struct acpi_processor_cx *cx = &pr->power.states[i]; 8941da177e4SLinus Torvalds 8951da177e4SLinus Torvalds switch (cx->type) { 8961da177e4SLinus Torvalds case ACPI_STATE_C1: 8971da177e4SLinus Torvalds cx->valid = 1; 8981da177e4SLinus Torvalds break; 8991da177e4SLinus Torvalds 9001da177e4SLinus Torvalds case ACPI_STATE_C2: 9011da177e4SLinus Torvalds acpi_processor_power_verify_c2(cx); 902bd663347SAndi Kleen #ifdef ARCH_APICTIMER_STOPS_ON_C3 903bd663347SAndi Kleen /* Some AMD systems fake C3 as C2, but still 904bd663347SAndi Kleen have timer troubles */ 905bd663347SAndi Kleen if (cx->valid && 906bd663347SAndi Kleen boot_cpu_data.x86_vendor == X86_VENDOR_AMD) 907bd663347SAndi Kleen timer_broadcast++; 908bd663347SAndi Kleen #endif 9091da177e4SLinus Torvalds break; 9101da177e4SLinus Torvalds 9111da177e4SLinus Torvalds case ACPI_STATE_C3: 9121da177e4SLinus Torvalds acpi_processor_power_verify_c3(pr, cx); 9136eb0a0fdSVenkatesh Pallipadi #ifdef ARCH_APICTIMER_STOPS_ON_C3 914bd663347SAndi Kleen if (cx->valid) 915bd663347SAndi Kleen timer_broadcast++; 9166eb0a0fdSVenkatesh Pallipadi #endif 9171da177e4SLinus Torvalds break; 9181da177e4SLinus Torvalds } 9191da177e4SLinus Torvalds 9201da177e4SLinus Torvalds if (cx->valid) 9211da177e4SLinus Torvalds working++; 9221da177e4SLinus Torvalds } 9231da177e4SLinus Torvalds 9240b5c59a1SAndi Kleen #ifdef ARCH_APICTIMER_STOPS_ON_C3 925bd663347SAndi Kleen if (timer_broadcast) 926bd663347SAndi Kleen on_each_cpu(switch_APIC_timer_to_ipi, &mask, 1, 1); 9270b5c59a1SAndi Kleen #endif 928bd663347SAndi Kleen 9291da177e4SLinus Torvalds return (working); 9301da177e4SLinus Torvalds } 9311da177e4SLinus Torvalds 9324be44fcdSLen Brown static int acpi_processor_get_power_info(struct acpi_processor *pr) 9331da177e4SLinus Torvalds { 9341da177e4SLinus Torvalds unsigned int i; 9351da177e4SLinus Torvalds int result; 9361da177e4SLinus Torvalds 9371da177e4SLinus Torvalds 9381da177e4SLinus Torvalds /* NOTE: the idle thread may not be running while calling 9391da177e4SLinus Torvalds * this function */ 9401da177e4SLinus Torvalds 941cf824788SJanosch Machowinski /* Adding C1 state */ 942cf824788SJanosch Machowinski acpi_processor_get_power_info_default_c1(pr); 9431da177e4SLinus Torvalds result = acpi_processor_get_power_info_cst(pr); 9446d93c648SVenkatesh Pallipadi if (result == -ENODEV) 945cf824788SJanosch Machowinski acpi_processor_get_power_info_fadt(pr); 9466d93c648SVenkatesh Pallipadi 947cf824788SJanosch Machowinski pr->power.count = acpi_processor_power_verify(pr); 9481da177e4SLinus Torvalds 9491da177e4SLinus Torvalds /* 9501da177e4SLinus Torvalds * Set Default Policy 9511da177e4SLinus Torvalds * ------------------ 9521da177e4SLinus Torvalds * Now that we know which states are supported, set the default 9531da177e4SLinus Torvalds * policy. Note that this policy can be changed dynamically 9541da177e4SLinus Torvalds * (e.g. encourage deeper sleeps to conserve battery life when 9551da177e4SLinus Torvalds * not on AC). 9561da177e4SLinus Torvalds */ 9571da177e4SLinus Torvalds result = acpi_processor_set_power_policy(pr); 9581da177e4SLinus Torvalds if (result) 959d550d98dSPatrick Mochel return result; 9601da177e4SLinus Torvalds 9611da177e4SLinus Torvalds /* 9621da177e4SLinus Torvalds * if one state of type C2 or C3 is available, mark this 9631da177e4SLinus Torvalds * CPU as being "idle manageable" 9641da177e4SLinus Torvalds */ 9651da177e4SLinus Torvalds for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) { 966acf05f4bSVenkatesh Pallipadi if (pr->power.states[i].valid) { 9671da177e4SLinus Torvalds pr->power.count = i; 9682203d6edSLinus Torvalds if (pr->power.states[i].type >= ACPI_STATE_C2) 9691da177e4SLinus Torvalds pr->flags.power = 1; 9701da177e4SLinus Torvalds } 971acf05f4bSVenkatesh Pallipadi } 9721da177e4SLinus Torvalds 973d550d98dSPatrick Mochel return 0; 9741da177e4SLinus Torvalds } 9751da177e4SLinus Torvalds 9761da177e4SLinus Torvalds int acpi_processor_cst_has_changed(struct acpi_processor *pr) 9771da177e4SLinus Torvalds { 9781da177e4SLinus Torvalds int result = 0; 9791da177e4SLinus Torvalds 9801da177e4SLinus Torvalds 9811da177e4SLinus Torvalds if (!pr) 982d550d98dSPatrick Mochel return -EINVAL; 9831da177e4SLinus Torvalds 98402df8b93SVenkatesh Pallipadi if (nocst) { 985d550d98dSPatrick Mochel return -ENODEV; 9861da177e4SLinus Torvalds } 9871da177e4SLinus Torvalds 9881da177e4SLinus Torvalds if (!pr->flags.power_setup_done) 989d550d98dSPatrick Mochel return -ENODEV; 9901da177e4SLinus Torvalds 9911da177e4SLinus Torvalds /* Fall back to the default idle loop */ 9921da177e4SLinus Torvalds pm_idle = pm_idle_save; 993fbd568a3SPaul E. McKenney synchronize_sched(); /* Relies on interrupts forcing exit from idle. */ 9941da177e4SLinus Torvalds 9951da177e4SLinus Torvalds pr->flags.power = 0; 9961da177e4SLinus Torvalds result = acpi_processor_get_power_info(pr); 9971da177e4SLinus Torvalds if ((pr->flags.power == 1) && (pr->flags.power_setup_done)) 9981da177e4SLinus Torvalds pm_idle = acpi_processor_idle; 9991da177e4SLinus Torvalds 1000d550d98dSPatrick Mochel return result; 10011da177e4SLinus Torvalds } 10021da177e4SLinus Torvalds 10031da177e4SLinus Torvalds /* proc interface */ 10041da177e4SLinus Torvalds 10051da177e4SLinus Torvalds static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset) 10061da177e4SLinus Torvalds { 10071da177e4SLinus Torvalds struct acpi_processor *pr = (struct acpi_processor *)seq->private; 10081da177e4SLinus Torvalds unsigned int i; 10091da177e4SLinus Torvalds 10101da177e4SLinus Torvalds 10111da177e4SLinus Torvalds if (!pr) 10121da177e4SLinus Torvalds goto end; 10131da177e4SLinus Torvalds 10141da177e4SLinus Torvalds seq_printf(seq, "active state: C%zd\n" 10151da177e4SLinus Torvalds "max_cstate: C%d\n" 10165c87579eSArjan van de Ven "bus master activity: %08x\n" 10175c87579eSArjan van de Ven "maximum allowed latency: %d usec\n", 10181da177e4SLinus Torvalds pr->power.state ? pr->power.state - pr->power.states : 0, 10195c87579eSArjan van de Ven max_cstate, (unsigned)pr->power.bm_activity, 10205c87579eSArjan van de Ven system_latency_constraint()); 10211da177e4SLinus Torvalds 10221da177e4SLinus Torvalds seq_puts(seq, "states:\n"); 10231da177e4SLinus Torvalds 10241da177e4SLinus Torvalds for (i = 1; i <= pr->power.count; i++) { 10251da177e4SLinus Torvalds seq_printf(seq, " %cC%d: ", 10264be44fcdSLen Brown (&pr->power.states[i] == 10274be44fcdSLen Brown pr->power.state ? '*' : ' '), i); 10281da177e4SLinus Torvalds 10291da177e4SLinus Torvalds if (!pr->power.states[i].valid) { 10301da177e4SLinus Torvalds seq_puts(seq, "<not supported>\n"); 10311da177e4SLinus Torvalds continue; 10321da177e4SLinus Torvalds } 10331da177e4SLinus Torvalds 10341da177e4SLinus Torvalds switch (pr->power.states[i].type) { 10351da177e4SLinus Torvalds case ACPI_STATE_C1: 10361da177e4SLinus Torvalds seq_printf(seq, "type[C1] "); 10371da177e4SLinus Torvalds break; 10381da177e4SLinus Torvalds case ACPI_STATE_C2: 10391da177e4SLinus Torvalds seq_printf(seq, "type[C2] "); 10401da177e4SLinus Torvalds break; 10411da177e4SLinus Torvalds case ACPI_STATE_C3: 10421da177e4SLinus Torvalds seq_printf(seq, "type[C3] "); 10431da177e4SLinus Torvalds break; 10441da177e4SLinus Torvalds default: 10451da177e4SLinus Torvalds seq_printf(seq, "type[--] "); 10461da177e4SLinus Torvalds break; 10471da177e4SLinus Torvalds } 10481da177e4SLinus Torvalds 10491da177e4SLinus Torvalds if (pr->power.states[i].promotion.state) 10501da177e4SLinus Torvalds seq_printf(seq, "promotion[C%zd] ", 10511da177e4SLinus Torvalds (pr->power.states[i].promotion.state - 10521da177e4SLinus Torvalds pr->power.states)); 10531da177e4SLinus Torvalds else 10541da177e4SLinus Torvalds seq_puts(seq, "promotion[--] "); 10551da177e4SLinus Torvalds 10561da177e4SLinus Torvalds if (pr->power.states[i].demotion.state) 10571da177e4SLinus Torvalds seq_printf(seq, "demotion[C%zd] ", 10581da177e4SLinus Torvalds (pr->power.states[i].demotion.state - 10591da177e4SLinus Torvalds pr->power.states)); 10601da177e4SLinus Torvalds else 10611da177e4SLinus Torvalds seq_puts(seq, "demotion[--] "); 10621da177e4SLinus Torvalds 1063a3c6598fSDominik Brodowski seq_printf(seq, "latency[%03d] usage[%08d] duration[%020llu]\n", 10641da177e4SLinus Torvalds pr->power.states[i].latency, 1065a3c6598fSDominik Brodowski pr->power.states[i].usage, 1066a3c6598fSDominik Brodowski pr->power.states[i].time); 10671da177e4SLinus Torvalds } 10681da177e4SLinus Torvalds 10691da177e4SLinus Torvalds end: 1070d550d98dSPatrick Mochel return 0; 10711da177e4SLinus Torvalds } 10721da177e4SLinus Torvalds 10731da177e4SLinus Torvalds static int acpi_processor_power_open_fs(struct inode *inode, struct file *file) 10741da177e4SLinus Torvalds { 10751da177e4SLinus Torvalds return single_open(file, acpi_processor_power_seq_show, 10761da177e4SLinus Torvalds PDE(inode)->data); 10771da177e4SLinus Torvalds } 10781da177e4SLinus Torvalds 1079d7508032SArjan van de Ven static const struct file_operations acpi_processor_power_fops = { 10801da177e4SLinus Torvalds .open = acpi_processor_power_open_fs, 10811da177e4SLinus Torvalds .read = seq_read, 10821da177e4SLinus Torvalds .llseek = seq_lseek, 10831da177e4SLinus Torvalds .release = single_release, 10841da177e4SLinus Torvalds }; 10851da177e4SLinus Torvalds 10865c87579eSArjan van de Ven static void smp_callback(void *v) 10875c87579eSArjan van de Ven { 10885c87579eSArjan van de Ven /* we already woke the CPU up, nothing more to do */ 10895c87579eSArjan van de Ven } 10905c87579eSArjan van de Ven 10915c87579eSArjan van de Ven /* 10925c87579eSArjan van de Ven * This function gets called when a part of the kernel has a new latency 10935c87579eSArjan van de Ven * requirement. This means we need to get all processors out of their C-state, 10945c87579eSArjan van de Ven * and then recalculate a new suitable C-state. Just do a cross-cpu IPI; that 10955c87579eSArjan van de Ven * wakes them all right up. 10965c87579eSArjan van de Ven */ 10975c87579eSArjan van de Ven static int acpi_processor_latency_notify(struct notifier_block *b, 10985c87579eSArjan van de Ven unsigned long l, void *v) 10995c87579eSArjan van de Ven { 11005c87579eSArjan van de Ven smp_call_function(smp_callback, NULL, 0, 1); 11015c87579eSArjan van de Ven return NOTIFY_OK; 11025c87579eSArjan van de Ven } 11035c87579eSArjan van de Ven 11045c87579eSArjan van de Ven static struct notifier_block acpi_processor_latency_notifier = { 11055c87579eSArjan van de Ven .notifier_call = acpi_processor_latency_notify, 11065c87579eSArjan van de Ven }; 11075c87579eSArjan van de Ven 1108*7af8b660SPierre Ossman int __cpuinit acpi_processor_power_init(struct acpi_processor *pr, 11094be44fcdSLen Brown struct acpi_device *device) 11101da177e4SLinus Torvalds { 11111da177e4SLinus Torvalds acpi_status status = 0; 1112b6835052SAndreas Mohr static int first_run; 11131da177e4SLinus Torvalds struct proc_dir_entry *entry = NULL; 11141da177e4SLinus Torvalds unsigned int i; 11151da177e4SLinus Torvalds 11161da177e4SLinus Torvalds 11171da177e4SLinus Torvalds if (!first_run) { 11181da177e4SLinus Torvalds dmi_check_system(processor_power_dmi_table); 11191da177e4SLinus Torvalds if (max_cstate < ACPI_C_STATES_MAX) 11204be44fcdSLen Brown printk(KERN_NOTICE 11214be44fcdSLen Brown "ACPI: processor limited to max C-state %d\n", 11224be44fcdSLen Brown max_cstate); 11231da177e4SLinus Torvalds first_run++; 11245c87579eSArjan van de Ven register_latency_notifier(&acpi_processor_latency_notifier); 11251da177e4SLinus Torvalds } 11261da177e4SLinus Torvalds 112702df8b93SVenkatesh Pallipadi if (!pr) 1128d550d98dSPatrick Mochel return -EINVAL; 112902df8b93SVenkatesh Pallipadi 113002df8b93SVenkatesh Pallipadi if (acpi_fadt.cst_cnt && !nocst) { 11314be44fcdSLen Brown status = 11324be44fcdSLen Brown acpi_os_write_port(acpi_fadt.smi_cmd, acpi_fadt.cst_cnt, 8); 11331da177e4SLinus Torvalds if (ACPI_FAILURE(status)) { 1134a6fc6720SThomas Renninger ACPI_EXCEPTION((AE_INFO, status, 1135a6fc6720SThomas Renninger "Notifying BIOS of _CST ability failed")); 11361da177e4SLinus Torvalds } 11371da177e4SLinus Torvalds } 11381da177e4SLinus Torvalds 11391da177e4SLinus Torvalds acpi_processor_get_power_info(pr); 11401da177e4SLinus Torvalds 11411da177e4SLinus Torvalds /* 11421da177e4SLinus Torvalds * Install the idle handler if processor power management is supported. 11431da177e4SLinus Torvalds * Note that we use previously set idle handler will be used on 11441da177e4SLinus Torvalds * platforms that only support C1. 11451da177e4SLinus Torvalds */ 11461da177e4SLinus Torvalds if ((pr->flags.power) && (!boot_option_idle_override)) { 11471da177e4SLinus Torvalds printk(KERN_INFO PREFIX "CPU%d (power states:", pr->id); 11481da177e4SLinus Torvalds for (i = 1; i <= pr->power.count; i++) 11491da177e4SLinus Torvalds if (pr->power.states[i].valid) 11504be44fcdSLen Brown printk(" C%d[C%d]", i, 11514be44fcdSLen Brown pr->power.states[i].type); 11521da177e4SLinus Torvalds printk(")\n"); 11531da177e4SLinus Torvalds 11541da177e4SLinus Torvalds if (pr->id == 0) { 11551da177e4SLinus Torvalds pm_idle_save = pm_idle; 11561da177e4SLinus Torvalds pm_idle = acpi_processor_idle; 11571da177e4SLinus Torvalds } 11581da177e4SLinus Torvalds } 11591da177e4SLinus Torvalds 11601da177e4SLinus Torvalds /* 'power' [R] */ 11611da177e4SLinus Torvalds entry = create_proc_entry(ACPI_PROCESSOR_FILE_POWER, 11621da177e4SLinus Torvalds S_IRUGO, acpi_device_dir(device)); 11631da177e4SLinus Torvalds if (!entry) 1164a6fc6720SThomas Renninger return -EIO; 11651da177e4SLinus Torvalds else { 11661da177e4SLinus Torvalds entry->proc_fops = &acpi_processor_power_fops; 11671da177e4SLinus Torvalds entry->data = acpi_driver_data(device); 11681da177e4SLinus Torvalds entry->owner = THIS_MODULE; 11691da177e4SLinus Torvalds } 11701da177e4SLinus Torvalds 11711da177e4SLinus Torvalds pr->flags.power_setup_done = 1; 11721da177e4SLinus Torvalds 1173d550d98dSPatrick Mochel return 0; 11741da177e4SLinus Torvalds } 11751da177e4SLinus Torvalds 11764be44fcdSLen Brown int acpi_processor_power_exit(struct acpi_processor *pr, 11774be44fcdSLen Brown struct acpi_device *device) 11781da177e4SLinus Torvalds { 11791da177e4SLinus Torvalds 11801da177e4SLinus Torvalds pr->flags.power_setup_done = 0; 11811da177e4SLinus Torvalds 11821da177e4SLinus Torvalds if (acpi_device_dir(device)) 11834be44fcdSLen Brown remove_proc_entry(ACPI_PROCESSOR_FILE_POWER, 11844be44fcdSLen Brown acpi_device_dir(device)); 11851da177e4SLinus Torvalds 11861da177e4SLinus Torvalds /* Unregister the idle handler when processor #0 is removed. */ 11871da177e4SLinus Torvalds if (pr->id == 0) { 11881da177e4SLinus Torvalds pm_idle = pm_idle_save; 11891da177e4SLinus Torvalds 11901da177e4SLinus Torvalds /* 11911da177e4SLinus Torvalds * We are about to unload the current idle thread pm callback 11921da177e4SLinus Torvalds * (pm_idle), Wait for all processors to update cached/local 11931da177e4SLinus Torvalds * copies of pm_idle before proceeding. 11941da177e4SLinus Torvalds */ 11951da177e4SLinus Torvalds cpu_idle_wait(); 11965c87579eSArjan van de Ven unregister_latency_notifier(&acpi_processor_latency_notifier); 11971da177e4SLinus Torvalds } 11981da177e4SLinus Torvalds 1199d550d98dSPatrick Mochel return 0; 12001da177e4SLinus Torvalds } 1201