diff options
Diffstat (limited to 'drivers/acpi/processor_idle.c')
| -rw-r--r-- | drivers/acpi/processor_idle.c | 1017 |
1 files changed, 1017 insertions, 0 deletions
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c new file mode 100644 index 000000000000..05a17812d521 --- /dev/null +++ b/drivers/acpi/processor_idle.c @@ -0,0 +1,1017 @@ +/* + * processor_idle - idle state submodule to the ACPI processor driver + * + * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com> + * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com> + * Copyright (C) 2004 Dominik Brodowski <linux@brodo.de> + * Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> + * - Added processor hotplug support + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or (at + * your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/cpufreq.h> +#include <linux/proc_fs.h> +#include <linux/seq_file.h> +#include <linux/acpi.h> +#include <linux/dmi.h> +#include <linux/moduleparam.h> + +#include <asm/io.h> +#include <asm/uaccess.h> + +#include <acpi/acpi_bus.h> +#include <acpi/processor.h> + +#define ACPI_PROCESSOR_COMPONENT 0x01000000 +#define ACPI_PROCESSOR_CLASS "processor" +#define ACPI_PROCESSOR_DRIVER_NAME "ACPI Processor Driver" +#define _COMPONENT ACPI_PROCESSOR_COMPONENT +ACPI_MODULE_NAME ("acpi_processor") + +#define ACPI_PROCESSOR_FILE_POWER "power" + +#define US_TO_PM_TIMER_TICKS(t) ((t * (PM_TIMER_FREQUENCY/1000)) / 1000) +#define C2_OVERHEAD 4 /* 1us (3.579 ticks per us) */ +#define C3_OVERHEAD 4 /* 1us (3.579 ticks per us) */ + +static void (*pm_idle_save)(void); +module_param(max_cstate, uint, 0644); + +static unsigned int nocst = 0; +module_param(nocst, uint, 0000); + +/* + * bm_history -- bit-mask with a bit per jiffy of bus-master activity + * 1000 HZ: 0xFFFFFFFF: 32 jiffies = 32ms + * 800 HZ: 0xFFFFFFFF: 32 jiffies = 40ms + * 100 HZ: 0x0000000F: 4 jiffies = 40ms + * reduce history for more aggressive entry into C3 + */ +static unsigned int bm_history = (HZ >= 800 ? 0xFFFFFFFF : ((1U << (HZ / 25)) - 1)); +module_param(bm_history, uint, 0644); +/* -------------------------------------------------------------------------- + Power Management + -------------------------------------------------------------------------- */ + +/* + * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3. + * For now disable this. Probably a bug somewhere else. + * + * To skip this limit, boot/load with a large max_cstate limit. + */ +static int no_c2c3(struct dmi_system_id *id) +{ + if (max_cstate > ACPI_PROCESSOR_MAX_POWER) + return 0; + + printk(KERN_NOTICE PREFIX "%s detected - C2,C3 disabled." + " Override with \"processor.max_cstate=%d\"\n", id->ident, + ACPI_PROCESSOR_MAX_POWER + 1); + + max_cstate = 1; + + return 0; +} + + + + +static struct dmi_system_id __initdata processor_power_dmi_table[] = { + { no_c2c3, "IBM ThinkPad R40e", { + DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), + DMI_MATCH(DMI_BIOS_VERSION,"1SET60WW") }}, + { no_c2c3, "Medion 41700", { + DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"), + DMI_MATCH(DMI_BIOS_VERSION,"R01-A1J") }}, + {}, +}; + + +static inline u32 +ticks_elapsed ( + u32 t1, + u32 t2) +{ + if (t2 >= t1) + return (t2 - t1); + else if (!acpi_fadt.tmr_val_ext) + return (((0x00FFFFFF - t1) + t2) & 0x00FFFFFF); + else + return ((0xFFFFFFFF - t1) + t2); +} + + +static void +acpi_processor_power_activate ( + struct acpi_processor *pr, + struct acpi_processor_cx *new) +{ + struct acpi_processor_cx *old; + + if (!pr || !new) + return; + + old = pr->power.state; + + if (old) + old->promotion.count = 0; + new->demotion.count = 0; + + /* Cleanup from old state. */ + if (old) { + switch (old->type) { + case ACPI_STATE_C3: + /* Disable bus master reload */ + if (new->type != ACPI_STATE_C3) + acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0, ACPI_MTX_DO_NOT_LOCK); + break; + } + } + + /* Prepare to use new state. */ + switch (new->type) { + case ACPI_STATE_C3: + /* Enable bus master reload */ + if (old->type != ACPI_STATE_C3) + acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 1, ACPI_MTX_DO_NOT_LOCK); + break; + } + + pr->power.state = new; + + return; +} + + +static void acpi_processor_idle (void) +{ + struct acpi_processor *pr = NULL; + struct acpi_processor_cx *cx = NULL; + struct acpi_processor_cx *next_state = NULL; + int sleep_ticks = 0; + u32 t1, t2 = 0; + + pr = processors[_smp_processor_id()]; + if (!pr) + return; + + /* + * Interrupts must be disabled during bus mastering calculations and + * for C2/C3 transitions. + */ + local_irq_disable(); + + /* + * Check whether we truly need to go idle, or should + * reschedule: + */ + if (unlikely(need_resched())) { + local_irq_enable(); + return; + } + + cx = pr->power.state; + if (!cx) + goto easy_out; + + /* + * Check BM Activity + * ----------------- + * Check for bus mastering activity (if required), record, and check + * for demotion. + */ + if (pr->flags.bm_check) { + u32 bm_status = 0; + unsigned long diff = jiffies - pr->power.bm_check_timestamp; + + if (diff > 32) + diff = 32; + + while (diff) { + /* if we didn't get called, assume there was busmaster activity */ + diff--; + if (diff) + pr->power.bm_activity |= 0x1; + pr->power.bm_activity <<= 1; + } + + acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS, + &bm_status, ACPI_MTX_DO_NOT_LOCK); + if (bm_status) { + pr->power.bm_activity++; + acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS, + 1, ACPI_MTX_DO_NOT_LOCK); + } + /* + * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect + * the true state of bus mastering activity; forcing us to + * manually check the BMIDEA bit of each IDE channel. + */ + else if (errata.piix4.bmisx) { + if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01) + || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01)) + pr->power.bm_activity++; + } + + pr->power.bm_check_timestamp = jiffies; + + /* + * Apply bus mastering demotion policy. Automatically demote + * to avoid a faulty transition. Note that the processor + * won't enter a low-power state during this call (to this + * funciton) but should upon the next. + * + * TBD: A better policy might be to fallback to the demotion + * state (use it for this quantum only) istead of + * demoting -- and rely on duration as our sole demotion + * qualification. This may, however, introduce DMA + * issues (e.g. floppy DMA transfer overrun/underrun). + */ + if (pr->power.bm_activity & cx->demotion.threshold.bm) { + local_irq_enable(); + next_state = cx->demotion.state; + goto end; + } + } + + cx->usage++; + + /* + * Sleep: + * ------ + * Invoke the current Cx state to put the processor to sleep. + */ + switch (cx->type) { + + case ACPI_STATE_C1: + /* + * Invoke C1. + * Use the appropriate idle routine, the one that would + * be used without acpi C-states. + */ + if (pm_idle_save) + pm_idle_save(); + else + safe_halt(); + /* + * TBD: Can't get time duration while in C1, as resumes + * go to an ISR rather than here. Need to instrument + * base interrupt handler. + */ + sleep_ticks = 0xFFFFFFFF; + break; + + case ACPI_STATE_C2: + /* Get start time (ticks) */ + t1 = inl(acpi_fadt.xpm_tmr_blk.address); + /* Invoke C2 */ + inb(cx->address); + /* Dummy op - must do something useless after P_LVL2 read */ + t2 = inl(acpi_fadt.xpm_tmr_blk.address); + /* Get end time (ticks) */ + t2 = inl(acpi_fadt.xpm_tmr_blk.address); + /* Re-enable interrupts */ + local_irq_enable(); + /* Compute time (ticks) that we were actually asleep */ + sleep_ticks = ticks_elapsed(t1, t2) - cx->latency_ticks - C2_OVERHEAD; + break; + + case ACPI_STATE_C3: + /* Disable bus master arbitration */ + acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1, ACPI_MTX_DO_NOT_LOCK); + /* Get start time (ticks) */ + t1 = inl(acpi_fadt.xpm_tmr_blk.address); + /* Invoke C3 */ + inb(cx->address); + /* Dummy op - must do something useless after P_LVL3 read */ + t2 = inl(acpi_fadt.xpm_tmr_blk.address); + /* Get end time (ticks) */ + t2 = inl(acpi_fadt.xpm_tmr_blk.address); + /* Enable bus master arbitration */ + acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0, ACPI_MTX_DO_NOT_LOCK); + /* Re-enable interrupts */ + local_irq_enable(); + /* Compute time (ticks) that we were actually asleep */ + sleep_ticks = ticks_elapsed(t1, t2) - cx->latency_ticks - C3_OVERHEAD; + break; + + default: + local_irq_enable(); + return; + } + + next_state = pr->power.state; + + /* + * Promotion? + * ---------- + * Track the number of longs (time asleep is greater than threshold) + * and promote when the count threshold is reached. Note that bus + * mastering activity may prevent promotions. + * Do not promote above max_cstate. + */ + if (cx->promotion.state && + ((cx->promotion.state - pr->power.states) <= max_cstate)) { + if (sleep_ticks > cx->promotion.threshold.ticks) { + cx->promotion.count++; + cx->demotion.count = 0; + if (cx->promotion.count >= cx->promotion.threshold.count) { + if (pr->flags.bm_check) { + if (!(pr->power.bm_activity & cx->promotion.threshold.bm)) { + next_state = cx->promotion.state; + goto end; + } + } + else { + next_state = cx->promotion.state; + goto end; + } + } + } + } + + /* + * Demotion? + * --------- + * Track the number of shorts (time asleep is less than time threshold) + * and demote when the usage threshold is reached. + */ + if (cx->demotion.state) { + if (sleep_ticks < cx->demotion.threshold.ticks) { + cx->demotion.count++; + cx->promotion.count = 0; + if (cx->demotion.count >= cx->demotion.threshold.count) { + next_state = cx->demotion.state; + goto end; + } + } + } + +end: + /* + * Demote if current state exceeds max_cstate + */ + if ((pr->power.state - pr->power.states) > max_cstate) { + if (cx->demotion.state) + next_state = cx->demotion.state; + } + + /* + * New Cx State? + * ------------- + * If we're going to start using a new Cx state we must clean up + * from the previous and prepare to use the new. + */ + if (next_state != pr->power.state) + acpi_processor_power_activate(pr, next_state); + + return; + + easy_out: + /* do C1 instead of busy loop */ + if (pm_idle_save) + pm_idle_save(); + else + safe_halt(); + return; +} + + +static int +acpi_processor_set_power_policy ( + struct acpi_processor *pr) +{ + unsigned int i; + unsigned int state_is_set = 0; + struct acpi_processor_cx *lower = NULL; + struct acpi_processor_cx *higher = NULL; + struct acpi_processor_cx *cx; + + ACPI_FUNCTION_TRACE("acpi_processor_set_power_policy"); + + if (!pr) + return_VALUE(-EINVAL); + + /* + * This function sets the default Cx state policy (OS idle handler). + * Our scheme is to promote quickly to C2 but more conservatively + * to C3. We're favoring C2 for its characteristics of low latency + * (quick response), good power savings, and ability to allow bus + * mastering activity. Note that the Cx state policy is completely + * customizable and can be altered dynamically. + */ + + /* startup state */ + for (i=1; i < ACPI_PROCESSOR_MAX_POWER; i++) { + cx = &pr->power.states[i]; + if (!cx->valid) + continue; + + if (!state_is_set) + pr->power.state = cx; + state_is_set++; + break; + } + + if (!state_is_set) + return_VALUE(-ENODEV); + + /* demotion */ + for (i=1; i < ACPI_PROCESSOR_MAX_POWER; i++) { + cx = &pr->power.states[i]; + if (!cx->valid) + continue; + + if (lower) { + cx->demotion.state = lower; + cx->demotion.threshold.ticks = cx->latency_ticks; + cx->demotion.threshold.count = 1; + if (cx->type == ACPI_STATE_C3) + cx->demotion.threshold.bm = bm_history; + } + + lower = cx; + } + + /* promotion */ + for (i = (ACPI_PROCESSOR_MAX_POWER - 1); i > 0; i--) { + cx = &pr->power.states[i]; + if (!cx->valid) + continue; + + if (higher) { + cx->promotion.state = higher; + cx->promotion.threshold.ticks = cx->latency_ticks; + if (cx->type >= ACPI_STATE_C2) + cx->promotion.threshold.count = 4; + else + cx->promotion.threshold.count = 10; + if (higher->type == ACPI_STATE_C3) + cx->promotion.threshold.bm = bm_history; + } + + higher = cx; + } + + return_VALUE(0); +} + + +static int acpi_processor_get_power_info_fadt (struct acpi_processor *pr) +{ + int i; + + ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_fadt"); + + if (!pr) + return_VALUE(-EINVAL); + + if (!pr->pblk) + return_VALUE(-ENODEV); + + for (i = 0; i < ACPI_PROCESSOR_MAX_POWER; i++) + memset(pr->power.states, 0, sizeof(struct acpi_processor_cx)); + + /* if info is obtained from pblk/fadt, type equals state */ + pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1; + pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2; + pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3; + + /* the C0 state only exists as a filler in our array, + * and all processors need to support C1 */ + pr->power.states[ACPI_STATE_C0].valid = 1; + pr->power.states[ACPI_STATE_C1].valid = 1; + + /* determine C2 and C3 address from pblk */ + pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4; + pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5; + + /* determine latencies from FADT */ + pr->power.states[ACPI_STATE_C2].latency = acpi_fadt.plvl2_lat; + pr->power.states[ACPI_STATE_C3].latency = acpi_fadt.plvl3_lat; + + ACPI_DEBUG_PRINT((ACPI_DB_INFO, + "lvl2[0x%08x] lvl3[0x%08x]\n", + pr->power.states[ACPI_STATE_C2].address, + pr->power.states[ACPI_STATE_C3].address)); + + return_VALUE(0); +} + + +static int acpi_processor_get_power_info_cst (struct acpi_processor *pr) +{ + acpi_status status = 0; + acpi_integer count; + int i; + struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL}; + union acpi_object *cst; + + ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_cst"); + + if (errata.smp) + return_VALUE(-ENODEV); + + if (nocst) + return_VALUE(-ENODEV); + + pr->power.count = 0; + for (i = 0; i < ACPI_PROCESSOR_MAX_POWER; i++) + memset(pr->power.states, 0, sizeof(struct acpi_processor_cx)); + + status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer); + if (ACPI_FAILURE(status)) { + ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n")); + return_VALUE(-ENODEV); + } + + cst = (union acpi_object *) buffer.pointer; + + /* There must be at least 2 elements */ + if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) { + ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "not enough elements in _CST\n")); + status = -EFAULT; + goto end; + } + + count = cst->package.elements[0].integer.value; + + /* Validate number of power states. */ + if (count < 1 || count != cst->package.count - 1) { + ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "count given by _CST is not valid\n")); + status = -EFAULT; + goto end; + } + + /* We support up to ACPI_PROCESSOR_MAX_POWER. */ + if (count > ACPI_PROCESSOR_MAX_POWER) { + printk(KERN_WARNING "Limiting number of power states to max (%d)\n", ACPI_PROCESSOR_MAX_POWER); + printk(KERN_WARNING "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n"); + count = ACPI_PROCESSOR_MAX_POWER; + } + + /* Tell driver that at least _CST is supported. */ + pr->flags.has_cst = 1; + + for (i = 1; i <= count; i++) { + union acpi_object *element; + union acpi_object *obj; + struct acpi_power_register *reg; + struct acpi_processor_cx cx; + + memset(&cx, 0, sizeof(cx)); + + element = (union acpi_object *) &(cst->package.elements[i]); + if (element->type != ACPI_TYPE_PACKAGE) + continue; + + if (element->package.count != 4) + continue; + + obj = (union acpi_object *) &(element->package.elements[0]); + + if (obj->type != ACPI_TYPE_BUFFER) + continue; + + reg = (struct acpi_power_register *) obj->buffer.pointer; + + if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO && + (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)) + continue; + + cx.address = (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) ? + 0 : reg->address; + + /* There should be an easy way to extract an integer... */ + obj = (union acpi_object *) &(element->package.elements[1]); + if (obj->type != ACPI_TYPE_INTEGER) + continue; + + cx.type = obj->integer.value; + + if ((cx.type != ACPI_STATE_C1) && + (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO)) + continue; + + if ((cx.type < ACPI_STATE_C1) || + (cx.type > ACPI_STATE_C3)) + continue; + + obj = (union acpi_object *) &(element->package.elements[2]); + if (obj->type != ACPI_TYPE_INTEGER) + continue; + + cx.latency = obj->integer.value; + + obj = (union acpi_object *) &(element->package.elements[3]); + if (obj->type != ACPI_TYPE_INTEGER) + continue; + + cx.power = obj->integer.value; + + (pr->power.count)++; + memcpy(&(pr->power.states[pr->power.count]), &cx, sizeof(cx)); + } + + ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n", pr->power.count)); + + /* Validate number of power states discovered */ + if (pr->power.count < 2) + status = -ENODEV; + +end: + acpi_os_free(buffer.pointer); + + return_VALUE(status); +} + + +static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx) +{ + ACPI_FUNCTION_TRACE("acpi_processor_get_power_verify_c2"); + + if (!cx->address) + return_VOID; + + /* + * C2 latency must be less than or equal to 100 + * microseconds. + */ + else if (cx->latency > ACPI_PROCESSOR_MAX_C2_LATENCY) { + ACPI_DEBUG_PRINT((ACPI_DB_INFO, + "latency too large [%d]\n", + cx->latency)); + return_VOID; + } + + /* We're (currently) only supporting C2 on UP */ + else if (errata.smp) { + ACPI_DEBUG_PRINT((ACPI_DB_INFO, + "C2 not supported in SMP mode\n")); + return_VOID; + } + + /* + * Otherwise we've met all of our C2 requirements. + * Normalize the C2 latency to expidite policy + */ + cx->valid = 1; + cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency); + + return_VOID; +} + + +static void acpi_processor_power_verify_c3( + struct acpi_processor *pr, + struct acpi_processor_cx *cx) +{ + ACPI_FUNCTION_TRACE("acpi_processor_get_power_verify_c3"); + + if (!cx->address) + return_VOID; + + /* + * C3 latency must be less than or equal to 1000 + * microseconds. + */ + else if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY) { + ACPI_DEBUG_PRINT((ACPI_DB_INFO, + "latency too large [%d]\n", + cx->latency)); + return_VOID; + } + + /* bus mastering control is necessary */ + else if (!pr->flags.bm_control) { + ACPI_DEBUG_PRINT((ACPI_DB_INFO, + "C3 support requires bus mastering control\n")); + return_VOID; + } + + /* We're (currently) only supporting C2 on UP */ + else if (errata.smp) { + ACPI_DEBUG_PRINT((ACPI_DB_INFO, + "C3 not supported in SMP mode\n")); + return_VOID; + } + + /* + * PIIX4 Erratum #18: We don't support C3 when Type-F (fast) + * DMA transfers are used by any ISA device to avoid livelock. + * Note that we could disable Type-F DMA (as recommended by + * the erratum), but this is known to disrupt certain ISA + * devices thus we take the conservative approach. + */ + else if (errata.piix4.fdma) { + ACPI_DEBUG_PRINT((ACPI_DB_INFO, + "C3 not supported on PIIX4 with Type-F DMA\n")); + return_VOID; + } + + /* + * Otherwise we've met all of our C3 requirements. + * Normalize the C3 latency to expidite policy. Enable + * checking of bus mastering status (bm_check) so we can + * use this in our C3 policy + */ + cx->valid = 1; + cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency); + pr->flags.bm_check = 1; + + return_VOID; +} + + +static int acpi_processor_power_verify(struct acpi_processor *pr) +{ + unsigned int i; + unsigned int working = 0; + + for (i=1; i < ACPI_PROCESSOR_MAX_POWER; i++) { + struct acpi_processor_cx *cx = &pr->power.states[i]; + + switch (cx->type) { + case ACPI_STATE_C1: + cx->valid = 1; + break; + + case ACPI_STATE_C2: + acpi_processor_power_verify_c2(cx); + break; + + case ACPI_STATE_C3: + acpi_processor_power_verify_c3(pr, cx); + break; + } + + if (cx->valid) + working++; + } + + return (working); +} + +static int acpi_processor_get_power_info ( + struct acpi_processor *pr) +{ + unsigned int i; + int result; + + ACPI_FUNCTION_TRACE("acpi_processor_get_power_info"); + + /* NOTE: the idle thread may not be running while calling + * this function */ + + result = acpi_processor_get_power_info_cst(pr); + if ((result) || (acpi_processor_power_verify(pr) < 2)) { + result = acpi_processor_get_power_info_fadt(pr); + if (result) + return_VALUE(result); + + if (acpi_processor_power_verify(pr) < 2) + return_VALUE(-ENODEV); + } + + /* + * Set Default Policy + * ------------------ + * Now that we know which states are supported, set the default + * policy. Note that this policy can be changed dynamically + * (e.g. encourage deeper sleeps to conserve battery life when + * not on AC). + */ + result = acpi_processor_set_power_policy(pr); + if (result) + return_VALUE(result); + + /* + * if one state of type C2 or C3 is available, mark this + * CPU as being "idle manageable" + */ + for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) { + if (pr->power.states[i].valid) + pr->power.count = i; + if ((pr->power.states[i].valid) && + (pr->power.states[i].type >= ACPI_STATE_C2)) + pr->flags.power = 1; + } + + return_VALUE(0); +} + +int acpi_processor_cst_has_changed (struct acpi_processor *pr) +{ + int result = 0; + + ACPI_FUNCTION_TRACE("acpi_processor_cst_has_changed"); + + if (!pr) + return_VALUE(-EINVAL); + + if (errata.smp || nocst) { + return_VALUE(-ENODEV); + } + + if (!pr->flags.power_setup_done) + return_VALUE(-ENODEV); + + /* Fall back to the default idle loop */ + pm_idle = pm_idle_save; + synchronize_kernel(); + + pr->flags.power = 0; + result = acpi_processor_get_power_info(pr); + if ((pr->flags.power == 1) && (pr->flags.power_setup_done)) + pm_idle = acpi_processor_idle; + + return_VALUE(result); +} + +/* proc interface */ + +static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset) +{ + struct acpi_processor *pr = (struct acpi_processor *)seq->private; + unsigned int i; + + ACPI_FUNCTION_TRACE("acpi_processor_power_seq_show"); + + if (!pr) + goto end; + + seq_printf(seq, "active state: C%zd\n" + "max_cstate: C%d\n" + "bus master activity: %08x\n", + pr->power.state ? pr->power.state - pr->power.states : 0, + max_cstate, + (unsigned)pr->power.bm_activity); + + seq_puts(seq, "states:\n"); + + for (i = 1; i <= pr->power.count; i++) { + seq_printf(seq, " %cC%d: ", + (&pr->power.states[i] == pr->power.state?'*':' '), i); + + if (!pr->power.states[i].valid) { + seq_puts(seq, "<not supported>\n"); + continue; + } + + switch (pr->power.states[i].type) { + case ACPI_STATE_C1: + seq_printf(seq, "type[C1] "); + break; + case ACPI_STATE_C2: + seq_printf(seq, "type[C2] "); + break; + case ACPI_STATE_C3: + seq_printf(seq, "type[C3] "); + break; + default: + seq_printf(seq, "type[--] "); + break; + } + + if (pr->power.states[i].promotion.state) + seq_printf(seq, "promotion[C%zd] ", + (pr->power.states[i].promotion.state - + pr->power.states)); + else + seq_puts(seq, "promotion[--] "); + + if (pr->power.states[i].demotion.state) + seq_printf(seq, "demotion[C%zd] ", + (pr->power.states[i].demotion.state - + pr->power.states)); + else + seq_puts(seq, "demotion[--] "); + + seq_printf(seq, "latency[%03d] usage[%08d]\n", + pr->power.states[i].latency, + pr->power.states[i].usage); + } + +end: + return_VALUE(0); +} + +static int acpi_processor_power_open_fs(struct inode *inode, struct file *file) +{ + return single_open(file, acpi_processor_power_seq_show, + PDE(inode)->data); +} + +static struct file_operations acpi_processor_power_fops = { + .open = acpi_processor_power_open_fs, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + + +int acpi_processor_power_init(struct acpi_processor *pr, struct acpi_device *device) +{ + acpi_status status = 0; + static int first_run = 0; + struct proc_dir_entry *entry = NULL; + unsigned int i; + + ACPI_FUNCTION_TRACE("acpi_processor_power_init"); + + if (!first_run) { + dmi_check_system(processor_power_dmi_table); + if (max_cstate < ACPI_C_STATES_MAX) + printk(KERN_NOTICE "ACPI: processor limited to max C-state %d\n", max_cstate); + first_run++; + } + + if (!errata.smp && (pr->id == 0) && acpi_fadt.cst_cnt && !nocst) { + status = acpi_os_write_port(acpi_fadt.smi_cmd, acpi_fadt.cst_cnt, 8); + if (ACPI_FAILURE(status)) { + ACPI_DEBUG_PRINT((ACPI_DB_ERROR, + "Notifying BIOS of _CST ability failed\n")); + } + } + + acpi_processor_get_power_info(pr); + + /* + * Install the idle handler if processor power management is supported. + * Note that we use previously set idle handler will be used on + * platforms that only support C1. + */ + if ((pr->flags.power) && (!boot_option_idle_override)) { + printk(KERN_INFO PREFIX "CPU%d (power states:", pr->id); + for (i = 1; i <= pr->power.count; i++) + if (pr->power.states[i].valid) + printk(" C%d[C%d]", i, pr->power.states[i].type); + printk(")\n"); + + if (pr->id == 0) { + pm_idle_save = pm_idle; + pm_idle = acpi_processor_idle; + } + } + + /* 'power' [R] */ + entry = create_proc_entry(ACPI_PROCESSOR_FILE_POWER, + S_IRUGO, acpi_device_dir(device)); + if (!entry) + ACPI_DEBUG_PRINT((ACPI_DB_ERROR, + "Unable to create '%s' fs entry\n", + ACPI_PROCESSOR_FILE_POWER)); + else { + entry->proc_fops = &acpi_processor_power_fops; + entry->data = acpi_driver_data(device); + entry->owner = THIS_MODULE; + } + + pr->flags.power_setup_done = 1; + + return_VALUE(0); +} + +int acpi_processor_power_exit(struct acpi_processor *pr, struct acpi_device *device) +{ + ACPI_FUNCTION_TRACE("acpi_processor_power_exit"); + + pr->flags.power_setup_done = 0; + + if (acpi_device_dir(device)) + remove_proc_entry(ACPI_PROCESSOR_FILE_POWER,acpi_device_dir(device)); + + /* Unregister the idle handler when processor #0 is removed. */ + if (pr->id == 0) { + pm_idle = pm_idle_save; + + /* + * We are about to unload the current idle thread pm callback + * (pm_idle), Wait for all processors to update cached/local + * copies of pm_idle before proceeding. + */ + cpu_idle_wait(); + } + + return_VALUE(0); +} |
