/* * 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 #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 ACPI_PROCESSOR_CLASS "processor" #define _COMPONENT ACPI_PROCESSOR_COMPONENT ACPI_MODULE_NAME("processor_idle"); #define ACPI_PROCESSOR_FILE_POWER "power" #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 unsigned int latency_factor __read_mostly = 2; module_param(latency_factor, uint, 0644); static s64 us_to_pm_timer_ticks(s64 t) { return div64_u64(t * PM_TIMER_FREQUENCY, 1000000); } /* * 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}, {}, }; /* * 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 acpi_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; /* * 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 acpi_propagate_timer_broadcast(struct acpi_processor *pr) { 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); } /* Power(C) State timer broadcast control */ static void acpi_state_timer_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 acpi_timer_check_state(int state, struct acpi_processor *pr, struct acpi_processor_cx *cstate) { } static void acpi_propagate_timer_broadcast(struct acpi_processor *pr) { } static void acpi_state_timer_broadcast(struct acpi_processor *pr, struct acpi_processor_cx *cx, int broadcast) { } #endif /* * Suspend / resume control */ static int acpi_idle_suspend; int acpi_processor_suspend(struct acpi_device * device, pm_message_t state) { acpi_idle_suspend = 1; return 0; } int acpi_processor_resume(struct acpi_device * device) { acpi_idle_suspend = 0; return 0; } #if defined (CONFIG_GENERIC_TIME) && 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; 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; acpi_integer 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 && (idle_halt || 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_c2(struct acpi_processor_cx *cx) { if (!cx->address) return; /* * 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; } /* * Otherwise we've met all of our C2 requirements. * Normalize the C2 latency to expidite policy */ cx->valid = 1; cx->latency_ticks = cx->latency; return; } static void acpi_processor_power_verify_c3(struct acpi_processor *pr, struct acpi_processor_cx *cx) { static int bm_check_flag; if (!cx->address) return; /* * 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; } /* * 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) { /* 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; } else { pr->flags.bm_check = bm_check_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; cx->latency_ticks = cx->latency; /* * 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: acpi_processor_power_verify_c2(cx); if (cx->valid) acpi_timer_check_state(i, pr, cx); break; case ACPI_STATE_C3: acpi_processor_power_verify_c3(pr, cx); if (cx->valid) acpi_timer_check_state(i, pr, cx); break; } if (cx->valid) tsc_check_state(cx->type); if (cx->valid) working++; } acpi_propagate_timer_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; } static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset) { struct acpi_processor *pr = seq->private; unsigned int i; if (!pr) goto end; seq_printf(seq, "active state: C%zd\n" "max_cstate: C%d\n" "maximum allowed latency: %d usec\n", pr->power.state ? pr->power.state - pr->power.states : 0, max_cstate, pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY)); 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, "\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] duration[%020llu]\n", pr->power.states[i].latency, pr->power.states[i].usage, (unsigned long long)pr->power.states[i].time); } end: return 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 const struct file_operations acpi_processor_power_fops = { .owner = THIS_MODULE, .open = acpi_processor_power_open_fs, .read = seq_read, .llseek = seq_lseek, .release = single_release, }; /** * acpi_idle_bm_check - checks if bus master activity was detected */ static int acpi_idle_bm_check(void) { u32 bm_status = 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 { int unused; /* 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. */ unused = 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 * @state: the state data * * This is equivalent to the HALT instruction. */ static int acpi_idle_enter_c1(struct cpuidle_device *dev, struct cpuidle_state *state) { ktime_t kt1, kt2; s64 idle_time; struct acpi_processor *pr; struct acpi_processor_cx *cx = cpuidle_get_statedata(state); pr = __get_cpu_var(processors); if (unlikely(!pr)) return 0; local_irq_disable(); /* Do not access any ACPI IO ports in suspend path */ if (acpi_idle_suspend) { acpi_safe_halt(); local_irq_enable(); return 0; } kt1 = ktime_get_real(); acpi_idle_do_entry(cx); kt2 = ktime_get_real(); idle_time = ktime_to_us(ktime_sub(kt2, kt1)); local_irq_enable(); cx->usage++; return idle_time; } /** * acpi_idle_enter_simple - enters an ACPI state without BM handling * @dev: the target CPU * @state: the state data */ static int acpi_idle_enter_simple(struct cpuidle_device *dev, struct cpuidle_state *state) { struct acpi_processor *pr; struct acpi_processor_cx *cx = cpuidle_get_statedata(state); ktime_t kt1, kt2; s64 idle_time; s64 sleep_ticks = 0; pr = __get_cpu_var(processors); if (unlikely(!pr)) return 0; if (acpi_idle_suspend) return(acpi_idle_enter_c1(dev, state)); local_irq_disable(); 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 0; } /* * Must be done before busmaster disable as we might need to * access HPET ! */ acpi_state_timer_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 = ktime_to_us(ktime_sub(kt2, kt1)); sleep_ticks = us_to_pm_timer_ticks(idle_time); /* Tell the scheduler how much we idled: */ sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS); local_irq_enable(); current_thread_info()->status |= TS_POLLING; cx->usage++; acpi_state_timer_broadcast(pr, cx, 0); cx->time += sleep_ticks; return idle_time; } static int c3_cpu_count; static DEFINE_SPINLOCK(c3_lock); /** * acpi_idle_enter_bm - enters C3 with proper BM handling * @dev: the target CPU * @state: the state data * * 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_state *state) { struct acpi_processor *pr; struct acpi_processor_cx *cx = cpuidle_get_statedata(state); ktime_t kt1, kt2; s64 idle_time; s64 sleep_ticks = 0; pr = __get_cpu_var(processors); if (unlikely(!pr)) return 0; if (acpi_idle_suspend) return(acpi_idle_enter_c1(dev, state)); if (acpi_idle_bm_check()) { if (dev->safe_state) { dev->last_state = dev->safe_state; return dev->safe_state->enter(dev, dev->safe_state); } else { local_irq_disable(); acpi_safe_halt(); local_irq_enable(); return 0; } } local_irq_disable(); 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 0; } 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 ! */ acpi_state_timer_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) { 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); 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) { spin_lock(&c3_lock); acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0); c3_cpu_count--; spin_unlock(&c3_lock); } kt2 = ktime_get_real(); idle_time = ktime_to_us(ktime_sub(kt2, kt1)); sleep_ticks = us_to_pm_timer_ticks(idle_time); /* Tell the scheduler how much we idled: */ sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS); local_irq_enable(); current_thread_info()->status |= TS_POLLING; cx->usage++; acpi_state_timer_broadcast(pr, cx, 0); cx->time += sleep_ticks; return idle_time; } struct cpuidle_driver acpi_idle_driver = { .name = "acpi_idle", .owner = THIS_MODULE, }; /** * acpi_processor_setup_cpuidle - prepares and configures CPUIDLE * @pr: the ACPI processor */ static int acpi_processor_setup_cpuidle(struct acpi_processor *pr) { int i, count = CPUIDLE_DRIVER_STATE_START; struct acpi_processor_cx *cx; struct cpuidle_state *state; 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; for (i = 0; i < CPUIDLE_STATE_MAX; i++) { dev->states[i].name[0] = '\0'; dev->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]; state = &dev->states[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, cx); 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->power_usage = cx->power; state->flags = 0; switch (cx->type) { case ACPI_STATE_C1: state->flags |= CPUIDLE_FLAG_SHALLOW; if (cx->entry_method == ACPI_CSTATE_FFH) state->flags |= CPUIDLE_FLAG_TIME_VALID; state->enter = acpi_idle_enter_c1; dev->safe_state = state; break; case ACPI_STATE_C2: state->flags |= CPUIDLE_FLAG_BALANCED; state->flags |= CPUIDLE_FLAG_TIME_VALID; state->enter = acpi_idle_enter_simple; dev->safe_state = state; break; case ACPI_STATE_C3: state->flags |= CPUIDLE_FLAG_DEEP; state->flags |= CPUIDLE_FLAG_TIME_VALID; state->flags |= CPUIDLE_FLAG_CHECK_BM; state->enter = pr->flags.bm_check ? acpi_idle_enter_bm : acpi_idle_enter_simple; break; } count++; if (count == CPUIDLE_STATE_MAX) break; } dev->state_count = count; if (!count) return -EINVAL; return 0; } int acpi_processor_cst_has_changed(struct acpi_processor *pr) { int ret = 0; if (boot_option_idle_override) 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(pr); ret = cpuidle_enable_device(&pr->power.dev); } cpuidle_resume_and_unlock(); return ret; } int __cpuinit acpi_processor_power_init(struct acpi_processor *pr, struct acpi_device *device) { acpi_status status = 0; static int first_run; struct proc_dir_entry *entry = NULL; unsigned int i; if (boot_option_idle_override) return 0; if (!first_run) { if (idle_halt) { /* * When the boot option of "idle=halt" is added, halt * is used for CPU IDLE. * In such case C2/C3 is meaningless. So the max_cstate * is set to one. */ max_cstate = 1; } 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) { acpi_processor_setup_cpuidle(pr); if (cpuidle_register_device(&pr->power.dev)) return -EIO; 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"); } /* 'power' [R] */ entry = proc_create_data(ACPI_PROCESSOR_FILE_POWER, S_IRUGO, acpi_device_dir(device), &acpi_processor_power_fops, acpi_driver_data(device)); if (!entry) return -EIO; return 0; } int acpi_processor_power_exit(struct acpi_processor *pr, struct acpi_device *device) { if (boot_option_idle_override) return 0; cpuidle_unregister_device(&pr->power.dev); pr->flags.power_setup_done = 0; if (acpi_device_dir(device)) remove_proc_entry(ACPI_PROCESSOR_FILE_POWER, acpi_device_dir(device)); return 0; }