/* * processor_idle - idle state submodule to the ACPI processor driver * * Copyright (C) 2001, 2002 Andy Grover * Copyright (C) 2001, 2002 Paul Diefenbaugh * Copyright (C) 2004, 2005 Dominik Brodowski * Copyright (C) 2004 Anil S Keshavamurthy * - Added processor hotplug support * Copyright (C) 2005 Venkatesh Pallipadi * - Added support for C3 on SMP * * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * * 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 #include #include #include #include #include #include #include #include /* need_resched() */ #include #include #include #include /* * Include the apic definitions for x86 to have the APIC timer related defines * available also for UP (on SMP it gets magically included via linux/smp.h). * asm/acpi.h is not an option, as it would require more include magic. Also * creating an empty asm-ia64/apic.h would just trade pest vs. cholera. */ #ifdef CONFIG_X86 #include #endif #include #include #include #include #include #define PREFIX "ACPI: " #define ACPI_PROCESSOR_CLASS "processor" #define _COMPONENT ACPI_PROCESSOR_COMPONENT ACPI_MODULE_NAME("processor_idle"); #define PM_TIMER_TICK_NS (1000000000ULL/PM_TIMER_FREQUENCY) #define C2_OVERHEAD 1 /* 1us */ #define C3_OVERHEAD 1 /* 1us */ #define PM_TIMER_TICKS_TO_US(p) (((p) * 1000)/(PM_TIMER_FREQUENCY/1000)) static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER; module_param(max_cstate, uint, 0000); static unsigned int nocst __read_mostly; module_param(nocst, uint, 0000); static int bm_check_disable __read_mostly; module_param(bm_check_disable, uint, 0000); static unsigned int latency_factor __read_mostly = 2; module_param(latency_factor, uint, 0644); static int disabled_by_idle_boot_param(void) { return boot_option_idle_override == IDLE_POLL || boot_option_idle_override == IDLE_FORCE_MWAIT || boot_option_idle_override == IDLE_HALT; } /* * 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 set_max_cstate(const struct dmi_system_id *id) { if (max_cstate > ACPI_PROCESSOR_MAX_POWER) return 0; printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate." " Override with \"processor.max_cstate=%d\"\n", id->ident, (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1); max_cstate = (long)id->driver_data; return 0; } /* Actually this shouldn't be __cpuinitdata, would be better to fix the callers to only run once -AK */ static struct dmi_system_id __cpuinitdata processor_power_dmi_table[] = { { set_max_cstate, "Clevo 5600D", { DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"), DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")}, (void *)2}, { set_max_cstate, "Pavilion zv5000", { DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"), DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")}, (void *)1}, { set_max_cstate, "Asus L8400B", { DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."), DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")}, (void *)1}, {}, }; /* * Callers should disable interrupts before the call and enable * interrupts after return. */ static void acpi_safe_halt(void) { current_thread_info()->status &= ~TS_POLLING; /* * TS_POLLING-cleared state must be visible before we * test NEED_RESCHED: */ smp_mb(); if (!need_resched()) { safe_halt(); local_irq_disable(); } current_thread_info()->status |= TS_POLLING; } #ifdef ARCH_APICTIMER_STOPS_ON_C3 /* * Some BIOS implementations switch to C3 in the published C2 state. * This seems to be a common problem on AMD boxen, but other vendors * are affected too. We pick the most conservative approach: we assume * that the local APIC stops in both C2 and C3. */ static void lapic_timer_check_state(int state, struct acpi_processor *pr, struct acpi_processor_cx *cx) { struct acpi_processor_power *pwr = &pr->power; u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2; if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT)) return; if (amd_e400_c1e_detected) type = ACPI_STATE_C1; /* * Check, if one of the previous states already marked the lapic * unstable */ if (pwr->timer_broadcast_on_state < state) return; if (cx->type >= type) pr->power.timer_broadcast_on_state = state; } static void __lapic_timer_propagate_broadcast(void *arg) { struct acpi_processor *pr = (struct acpi_processor *) arg; unsigned long reason; reason = pr->power.timer_broadcast_on_state < INT_MAX ? CLOCK_EVT_NOTIFY_BROADCAST_ON : CLOCK_EVT_NOTIFY_BROADCAST_OFF; clockevents_notify(reason, &pr->id); } static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast, (void *)pr, 1); } /* Power(C) State timer broadcast control */ static void lapic_timer_state_broadcast(struct acpi_processor *pr, struct acpi_processor_cx *cx, int broadcast) { int state = cx - pr->power.states; if (state >= pr->power.timer_broadcast_on_state) { unsigned long reason; reason = broadcast ? CLOCK_EVT_NOTIFY_BROADCAST_ENTER : CLOCK_EVT_NOTIFY_BROADCAST_EXIT; clockevents_notify(reason, &pr->id); } } #else static void lapic_timer_check_state(int state, struct acpi_processor *pr, struct acpi_processor_cx *cstate) { } static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { } static void lapic_timer_state_broadcast(struct acpi_processor *pr, struct acpi_processor_cx *cx, int broadcast) { } #endif static u32 saved_bm_rld; static void acpi_idle_bm_rld_save(void) { acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &saved_bm_rld); } static void acpi_idle_bm_rld_restore(void) { u32 resumed_bm_rld; acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &resumed_bm_rld); if (resumed_bm_rld != saved_bm_rld) acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, saved_bm_rld); } int acpi_processor_suspend(struct acpi_device * device, pm_message_t state) { acpi_idle_bm_rld_save(); return 0; } int acpi_processor_resume(struct acpi_device * device) { acpi_idle_bm_rld_restore(); return 0; } #if defined(CONFIG_X86) static void tsc_check_state(int state) { switch (boot_cpu_data.x86_vendor) { case X86_VENDOR_AMD: case X86_VENDOR_INTEL: /* * AMD Fam10h TSC will tick in all * C/P/S0/S1 states when this bit is set. */ if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC)) return; /*FALL THROUGH*/ default: /* TSC could halt in idle, so notify users */ if (state > ACPI_STATE_C1) mark_tsc_unstable("TSC halts in idle"); } } #else static void tsc_check_state(int state) { return; } #endif static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr) { if (!pr) return -EINVAL; if (!pr->pblk) return -ENODEV; /* if info is obtained from pblk/fadt, type equals state */ pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2; pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3; #ifndef CONFIG_HOTPLUG_CPU /* * Check for P_LVL2_UP flag before entering C2 and above on * an SMP system. */ if ((num_online_cpus() > 1) && !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED)) return -ENODEV; #endif /* 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_gbl_FADT.C2latency; pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.C3latency; /* * FADT specified C2 latency must be less than or equal to * 100 microseconds. */ if (acpi_gbl_FADT.C2latency > ACPI_PROCESSOR_MAX_C2_LATENCY) { ACPI_DEBUG_PRINT((ACPI_DB_INFO, "C2 latency too large [%d]\n", acpi_gbl_FADT.C2latency)); /* invalidate C2 */ pr->power.states[ACPI_STATE_C2].address = 0; } /* * FADT supplied C3 latency must be less than or equal to * 1000 microseconds. */ if (acpi_gbl_FADT.C3latency > ACPI_PROCESSOR_MAX_C3_LATENCY) { ACPI_DEBUG_PRINT((ACPI_DB_INFO, "C3 latency too large [%d]\n", acpi_gbl_FADT.C3latency)); /* invalidate C3 */ pr->power.states[ACPI_STATE_C3].address = 0; } 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 0; } static int acpi_processor_get_power_info_default(struct acpi_processor *pr) { if (!pr->power.states[ACPI_STATE_C1].valid) { /* set the first C-State to C1 */ /* all processors need to support C1 */ pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1; pr->power.states[ACPI_STATE_C1].valid = 1; pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT; } /* the C0 state only exists as a filler in our array */ pr->power.states[ACPI_STATE_C0].valid = 1; return 0; } static int acpi_processor_get_power_info_cst(struct acpi_processor *pr) { acpi_status status = 0; u64 count; int current_count; int i; struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; union acpi_object *cst; if (nocst) return -ENODEV; current_count = 0; 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 -ENODEV; } cst = buffer.pointer; /* There must be at least 2 elements */ if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) { printk(KERN_ERR PREFIX "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) { printk(KERN_ERR PREFIX "count given by _CST is not valid\n"); status = -EFAULT; goto end; } /* 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 = &(cst->package.elements[i]); if (element->type != ACPI_TYPE_PACKAGE) continue; if (element->package.count != 4) continue; obj = &(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; /* There should be an easy way to extract an integer... */ obj = &(element->package.elements[1]); if (obj->type != ACPI_TYPE_INTEGER) continue; cx.type = obj->integer.value; /* * Some buggy BIOSes won't list C1 in _CST - * Let acpi_processor_get_power_info_default() handle them later */ if (i == 1 && cx.type != ACPI_STATE_C1) current_count++; cx.address = reg->address; cx.index = current_count + 1; cx.entry_method = ACPI_CSTATE_SYSTEMIO; if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) { if (acpi_processor_ffh_cstate_probe (pr->id, &cx, reg) == 0) { cx.entry_method = ACPI_CSTATE_FFH; } else if (cx.type == ACPI_STATE_C1) { /* * C1 is a special case where FIXED_HARDWARE * can be handled in non-MWAIT way as well. * In that case, save this _CST entry info. * Otherwise, ignore this info and continue. */ cx.entry_method = ACPI_CSTATE_HALT; snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT"); } else { continue; } if (cx.type == ACPI_STATE_C1 && (boot_option_idle_override == IDLE_NOMWAIT)) { /* * In most cases the C1 space_id obtained from * _CST object is FIXED_HARDWARE access mode. * But when the option of idle=halt is added, * the entry_method type should be changed from * CSTATE_FFH to CSTATE_HALT. * When the option of idle=nomwait is added, * the C1 entry_method type should be * CSTATE_HALT. */ cx.entry_method = ACPI_CSTATE_HALT; snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT"); } } else { snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x", cx.address); } if (cx.type == ACPI_STATE_C1) { cx.valid = 1; } obj = &(element->package.elements[2]); if (obj->type != ACPI_TYPE_INTEGER) continue; cx.latency = obj->integer.value; obj = &(element->package.elements[3]); if (obj->type != ACPI_TYPE_INTEGER) continue; cx.power = obj->integer.value; current_count++; memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx)); /* * We support total ACPI_PROCESSOR_MAX_POWER - 1 * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1) */ if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) { 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"); break; } } ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n", current_count)); /* Validate number of power states discovered */ if (current_count < 2) status = -EFAULT; end: kfree(buffer.pointer); return status; } static void acpi_processor_power_verify_c3(struct acpi_processor *pr, struct acpi_processor_cx *cx) { static int bm_check_flag = -1; static int bm_control_flag = -1; if (!cx->address) return; /* * 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; } /* All the logic here assumes flags.bm_check is same across all CPUs */ if (bm_check_flag == -1) { /* Determine whether bm_check is needed based on CPU */ acpi_processor_power_init_bm_check(&(pr->flags), pr->id); bm_check_flag = pr->flags.bm_check; bm_control_flag = pr->flags.bm_control; } else { pr->flags.bm_check = bm_check_flag; pr->flags.bm_control = bm_control_flag; } if (pr->flags.bm_check) { if (!pr->flags.bm_control) { if (pr->flags.has_cst != 1) { /* bus mastering control is necessary */ ACPI_DEBUG_PRINT((ACPI_DB_INFO, "C3 support requires BM control\n")); return; } else { /* Here we enter C3 without bus mastering */ ACPI_DEBUG_PRINT((ACPI_DB_INFO, "C3 support without BM control\n")); } } } else { /* * WBINVD should be set in fadt, for C3 state to be * supported on when bm_check is not required. */ if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) { ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Cache invalidation should work properly" " for C3 to be enabled on SMP systems\n")); return; } } /* * 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; /* * On older chipsets, BM_RLD needs to be set * in order for Bus Master activity to wake the * system from C3. Newer chipsets handle DMA * during C3 automatically and BM_RLD is a NOP. * In either case, the proper way to * handle BM_RLD is to set it and leave it set. */ acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1); return; } static int acpi_processor_power_verify(struct acpi_processor *pr) { unsigned int i; unsigned int working = 0; pr->power.timer_broadcast_on_state = INT_MAX; for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; 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: if (!cx->address) break; cx->valid = 1; break; case ACPI_STATE_C3: acpi_processor_power_verify_c3(pr, cx); break; } if (!cx->valid) continue; lapic_timer_check_state(i, pr, cx); tsc_check_state(cx->type); working++; } lapic_timer_propagate_broadcast(pr); return (working); } static int acpi_processor_get_power_info(struct acpi_processor *pr) { unsigned int i; int result; /* NOTE: the idle thread may not be running while calling * this function */ /* Zero initialize all the C-states info. */ memset(pr->power.states, 0, sizeof(pr->power.states)); result = acpi_processor_get_power_info_cst(pr); if (result == -ENODEV) result = acpi_processor_get_power_info_fadt(pr); if (result) return result; acpi_processor_get_power_info_default(pr); pr->power.count = acpi_processor_power_verify(pr); /* * 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].type >= ACPI_STATE_C2) pr->flags.power = 1; } } return 0; } /** * acpi_idle_bm_check - checks if bus master activity was detected */ static int acpi_idle_bm_check(void) { u32 bm_status = 0; if (bm_check_disable) return 0; acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status); if (bm_status) acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1); /* * 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)) bm_status = 1; } return bm_status; } /** * acpi_idle_do_entry - a helper function that does C2 and C3 type entry * @cx: cstate data * * Caller disables interrupt before call and enables interrupt after return. */ static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx) { /* Don't trace irqs off for idle */ stop_critical_timings(); if (cx->entry_method == ACPI_CSTATE_FFH) { /* Call into architectural FFH based C-state */ acpi_processor_ffh_cstate_enter(cx); } else if (cx->entry_method == ACPI_CSTATE_HALT) { acpi_safe_halt(); } else { /* IO port based C-state */ inb(cx->address); /* Dummy wait op - must do something useless after P_LVL2 read because chipsets cannot guarantee that STPCLK# signal gets asserted in time to freeze execution properly. */ inl(acpi_gbl_FADT.xpm_timer_block.address); } start_critical_timings(); } /** * acpi_idle_enter_c1 - enters an ACPI C1 state-type * @dev: the target CPU * @drv: cpuidle driver containing cpuidle state info * @index: index of target state * * This is equivalent to the HALT instruction. */ static int acpi_idle_enter_c1(struct cpuidle_device *dev, struct cpuidle_driver *drv, int index) { ktime_t kt1, kt2; s64 idle_time; struct acpi_processor *pr; struct cpuidle_state_usage *state_usage = &dev->states_usage[index]; struct acpi_processor_cx *cx = cpuidle_get_statedata(state_usage); pr = __this_cpu_read(processors); dev->last_residency = 0; if (unlikely(!pr)) return -EINVAL; local_irq_disable(); lapic_timer_state_broadcast(pr, cx, 1); kt1 = ktime_get_real(); acpi_idle_do_entry(cx); kt2 = ktime_get_real(); idle_time = ktime_to_us(ktime_sub(kt2, kt1)); /* Update device last_residency*/ dev->last_residency = (int)idle_time; local_irq_enable(); lapic_timer_state_broadcast(pr, cx, 0); return index; } /** * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining) * @dev: the target CPU * @index: the index of suggested state */ static int acpi_idle_play_dead(struct cpuidle_device *dev, int index) { struct cpuidle_state_usage *state_usage = &dev->states_usage[index]; struct acpi_processor_cx *cx = cpuidle_get_statedata(state_usage); ACPI_FLUSH_CPU_CACHE(); while (1) { if (cx->entry_method == ACPI_CSTATE_HALT) safe_halt(); else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) { inb(cx->address); /* See comment in acpi_idle_do_entry() */ inl(acpi_gbl_FADT.xpm_timer_block.address); } else return -ENODEV; } /* Never reached */ return 0; } /** * acpi_idle_enter_simple - enters an ACPI state without BM handling * @dev: the target CPU * @drv: cpuidle driver with cpuidle state information * @index: the index of suggested state */ static int acpi_idle_enter_simple(struct cpuidle_device *dev, struct cpuidle_driver *drv, int index) { struct acpi_processor *pr; struct cpuidle_state_usage *state_usage = &dev->states_usage[index]; struct acpi_processor_cx *cx = cpuidle_get_statedata(state_usage); ktime_t kt1, kt2; s64 idle_time_ns; s64 idle_time; pr = __this_cpu_read(processors); dev->last_residency = 0; if (unlikely(!pr)) return -EINVAL; local_irq_disable(); if (cx->entry_method != ACPI_CSTATE_FFH) { current_thread_info()->status &= ~TS_POLLING; /* * TS_POLLING-cleared state must be visible before we test * NEED_RESCHED: */ smp_mb(); if (unlikely(need_resched())) { current_thread_info()->status |= TS_POLLING; local_irq_enable(); return -EINVAL; } } /* * Must be done before busmaster disable as we might need to * access HPET ! */ lapic_timer_state_broadcast(pr, cx, 1); if (cx->type == ACPI_STATE_C3) ACPI_FLUSH_CPU_CACHE(); kt1 = ktime_get_real(); /* Tell the scheduler that we are going deep-idle: */ sched_clock_idle_sleep_event(); acpi_idle_do_entry(cx); kt2 = ktime_get_real(); idle_time_ns = ktime_to_ns(ktime_sub(kt2, kt1)); idle_time = idle_time_ns; do_div(idle_time, NSEC_PER_USEC); /* Update device last_residency*/ dev->last_residency = (int)idle_time; /* Tell the scheduler how much we idled: */ sched_clock_idle_wakeup_event(idle_time_ns); local_irq_enable(); if (cx->entry_method != ACPI_CSTATE_FFH) current_thread_info()->status |= TS_POLLING; lapic_timer_state_broadcast(pr, cx, 0); cx->time += idle_time; return index; } static int c3_cpu_count; static DEFINE_RAW_SPINLOCK(c3_lock); /** * acpi_idle_enter_bm - enters C3 with proper BM handling * @dev: the target CPU * @drv: cpuidle driver containing state data * @index: the index of suggested state * * If BM is detected, the deepest non-C3 idle state is entered instead. */ static int acpi_idle_enter_bm(struct cpuidle_device *dev, struct cpuidle_driver *drv, int index) { struct acpi_processor *pr; struct cpuidle_state_usage *state_usage = &dev->states_usage[index]; struct acpi_processor_cx *cx = cpuidle_get_statedata(state_usage); ktime_t kt1, kt2; s64 idle_time_ns; s64 idle_time; pr = __this_cpu_read(processors); dev->last_residency = 0; if (unlikely(!pr)) return -EINVAL; if (!cx->bm_sts_skip && acpi_idle_bm_check()) { if (drv->safe_state_index >= 0) { return drv->states[drv->safe_state_index].enter(dev, drv, drv->safe_state_index); } else { local_irq_disable(); acpi_safe_halt(); local_irq_enable(); return -EBUSY; } } local_irq_disable(); if (cx->entry_method != ACPI_CSTATE_FFH) { current_thread_info()->status &= ~TS_POLLING; /* * TS_POLLING-cleared state must be visible before we test * NEED_RESCHED: */ smp_mb(); if (unlikely(need_resched())) { current_thread_info()->status |= TS_POLLING; local_irq_enable(); return -EINVAL; } } acpi_unlazy_tlb(smp_processor_id()); /* Tell the scheduler that we are going deep-idle: */ sched_clock_idle_sleep_event(); /* * Must be done before busmaster disable as we might need to * access HPET ! */ lapic_timer_state_broadcast(pr, cx, 1); kt1 = ktime_get_real(); /* * disable bus master * bm_check implies we need ARB_DIS * !bm_check implies we need cache flush * bm_control implies whether we can do ARB_DIS * * That leaves a case where bm_check is set and bm_control is * not set. In that case we cannot do much, we enter C3 * without doing anything. */ if (pr->flags.bm_check && pr->flags.bm_control) { raw_spin_lock(&c3_lock); c3_cpu_count++; /* Disable bus master arbitration when all CPUs are in C3 */ if (c3_cpu_count == num_online_cpus()) acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1); raw_spin_unlock(&c3_lock); } else if (!pr->flags.bm_check) { ACPI_FLUSH_CPU_CACHE(); } acpi_idle_do_entry(cx); /* Re-enable bus master arbitration */ if (pr->flags.bm_check && pr->flags.bm_control) { raw_spin_lock(&c3_lock); acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0); c3_cpu_count--; raw_spin_unlock(&c3_lock); } kt2 = ktime_get_real(); idle_time_ns = ktime_to_ns(ktime_sub(kt2, kt1)); idle_time = idle_time_ns; do_div(idle_time, NSEC_PER_USEC); /* Update device last_residency*/ dev->last_residency = (int)idle_time; /* Tell the scheduler how much we idled: */ sched_clock_idle_wakeup_event(idle_time_ns); local_irq_enable(); if (cx->entry_method != ACPI_CSTATE_FFH) current_thread_info()->status |= TS_POLLING; lapic_timer_state_broadcast(pr, cx, 0); cx->time += idle_time; return index; } struct cpuidle_driver acpi_idle_driver = { .name = "acpi_idle", .owner = THIS_MODULE, }; /** * acpi_processor_setup_cpuidle_cx - prepares and configures CPUIDLE * device i.e. per-cpu data * * @pr: the ACPI processor */ static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr) { int i, count = CPUIDLE_DRIVER_STATE_START; struct acpi_processor_cx *cx; struct cpuidle_state_usage *state_usage; struct cpuidle_device *dev = &pr->power.dev; if (!pr->flags.power_setup_done) return -EINVAL; if (pr->flags.power == 0) { return -EINVAL; } dev->cpu = pr->id; if (max_cstate == 0) max_cstate = 1; for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { cx = &pr->power.states[i]; state_usage = &dev->states_usage[count]; if (!cx->valid) continue; #ifdef CONFIG_HOTPLUG_CPU if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) && !pr->flags.has_cst && !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED)) continue; #endif cpuidle_set_statedata(state_usage, cx); count++; if (count == CPUIDLE_STATE_MAX) break; } dev->state_count = count; if (!count) return -EINVAL; return 0; } /** * acpi_processor_setup_cpuidle states- prepares and configures cpuidle * global state data i.e. idle routines * * @pr: the ACPI processor */ static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr) { int i, count = CPUIDLE_DRIVER_STATE_START; struct acpi_processor_cx *cx; struct cpuidle_state *state; struct cpuidle_driver *drv = &acpi_idle_driver; if (!pr->flags.power_setup_done) return -EINVAL; if (pr->flags.power == 0) return -EINVAL; drv->safe_state_index = -1; for (i = 0; i < CPUIDLE_STATE_MAX; i++) { drv->states[i].name[0] = '\0'; drv->states[i].desc[0] = '\0'; } if (max_cstate == 0) max_cstate = 1; for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { cx = &pr->power.states[i]; if (!cx->valid) continue; #ifdef CONFIG_HOTPLUG_CPU if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) && !pr->flags.has_cst && !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED)) continue; #endif state = &drv->states[count]; snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i); strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN); state->exit_latency = cx->latency; state->target_residency = cx->latency * latency_factor; state->flags = 0; switch (cx->type) { case ACPI_STATE_C1: if (cx->entry_method == ACPI_CSTATE_FFH) state->flags |= CPUIDLE_FLAG_TIME_VALID; state->enter = acpi_idle_enter_c1; state->enter_dead = acpi_idle_play_dead; drv->safe_state_index = count; break; case ACPI_STATE_C2: state->flags |= CPUIDLE_FLAG_TIME_VALID; state->enter = acpi_idle_enter_simple; state->enter_dead = acpi_idle_play_dead; drv->safe_state_index = count; break; case ACPI_STATE_C3: state->flags |= CPUIDLE_FLAG_TIME_VALID; state->enter = pr->flags.bm_check ? acpi_idle_enter_bm : acpi_idle_enter_simple; break; } count++; if (count == CPUIDLE_STATE_MAX) break; } drv->state_count = count; if (!count) return -EINVAL; return 0; } int acpi_processor_hotplug(struct acpi_processor *pr) { int ret = 0; if (disabled_by_idle_boot_param()) return 0; if (!pr) return -EINVAL; if (nocst) { return -ENODEV; } if (!pr->flags.power_setup_done) return -ENODEV; cpuidle_pause_and_lock(); cpuidle_disable_device(&pr->power.dev); acpi_processor_get_power_info(pr); if (pr->flags.power) { acpi_processor_setup_cpuidle_cx(pr); ret = cpuidle_enable_device(&pr->power.dev); } cpuidle_resume_and_unlock(); return ret; } int acpi_processor_cst_has_changed(struct acpi_processor *pr) { int cpu; struct acpi_processor *_pr; if (disabled_by_idle_boot_param()) return 0; if (!pr) return -EINVAL; if (nocst) return -ENODEV; if (!pr->flags.power_setup_done) return -ENODEV; /* * FIXME: Design the ACPI notification to make it once per * system instead of once per-cpu. This condition is a hack * to make the code that updates C-States be called once. */ if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) { cpuidle_pause_and_lock(); /* Protect against cpu-hotplug */ get_online_cpus(); /* Disable all cpuidle devices */ for_each_online_cpu(cpu) { _pr = per_cpu(processors, cpu); if (!_pr || !_pr->flags.power_setup_done) continue; cpuidle_disable_device(&_pr->power.dev); } /* Populate Updated C-state information */ acpi_processor_setup_cpuidle_states(pr); /* Enable all cpuidle devices */ for_each_online_cpu(cpu) { _pr = per_cpu(processors, cpu); if (!_pr || !_pr->flags.power_setup_done) continue; acpi_processor_get_power_info(_pr); if (_pr->flags.power) { acpi_processor_setup_cpuidle_cx(_pr); cpuidle_enable_device(&_pr->power.dev); } } put_online_cpus(); cpuidle_resume_and_unlock(); } return 0; } static int acpi_processor_registered; int __cpuinit acpi_processor_power_init(struct acpi_processor *pr, struct acpi_device *device) { acpi_status status = 0; int retval; static int first_run; if (disabled_by_idle_boot_param()) return 0; if (!first_run) { dmi_check_system(processor_power_dmi_table); max_cstate = acpi_processor_cstate_check(max_cstate); if (max_cstate < ACPI_C_STATES_MAX) printk(KERN_NOTICE "ACPI: processor limited to max C-state %d\n", max_cstate); first_run++; } if (!pr) return -EINVAL; if (acpi_gbl_FADT.cst_control && !nocst) { status = acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8); if (ACPI_FAILURE(status)) { ACPI_EXCEPTION((AE_INFO, status, "Notifying BIOS of _CST ability failed")); } } acpi_processor_get_power_info(pr); pr->flags.power_setup_done = 1; /* * 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) { /* Register acpi_idle_driver if not already registered */ if (!acpi_processor_registered) { acpi_processor_setup_cpuidle_states(pr); retval = cpuidle_register_driver(&acpi_idle_driver); if (retval) return retval; printk(KERN_DEBUG "ACPI: %s registered with cpuidle\n", acpi_idle_driver.name); } /* Register per-cpu cpuidle_device. Cpuidle driver * must already be registered before registering device */ acpi_processor_setup_cpuidle_cx(pr); retval = cpuidle_register_device(&pr->power.dev); if (retval) { if (acpi_processor_registered == 0) cpuidle_unregister_driver(&acpi_idle_driver); return retval; } acpi_processor_registered++; } return 0; } int acpi_processor_power_exit(struct acpi_processor *pr, struct acpi_device *device) { if (disabled_by_idle_boot_param()) return 0; if (pr->flags.power) { cpuidle_unregister_device(&pr->power.dev); acpi_processor_registered--; if (acpi_processor_registered == 0) cpuidle_unregister_driver(&acpi_idle_driver); } pr->flags.power_setup_done = 0; return 0; }