projects / linux-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 1da1180c PM |
1 | /* |
| 2 | * The idle loop for all SuperH platforms. | |
| 3 | * | |
| 2e046b94 | 4 | * Copyright (C) 2002 - 2009 Paul Mundt |
| 1da1180c PM |
5 | * |
| 6 | * This file is subject to the terms and conditions of the GNU General Public | |
| 7 | * License. See the file "COPYING" in the main directory of this archive | |
| 8 | * for more details. | |
| 9 | */ | |
| 10 | #include <linux/module.h> | |
| 11 | #include <linux/init.h> | |
| 12 | #include <linux/mm.h> | |
| 13 | #include <linux/pm.h> | |
| 14 | #include <linux/tick.h> | |
| 15 | #include <linux/preempt.h> | |
| 16 | #include <linux/thread_info.h> | |
| 17 | #include <linux/irqflags.h> | |
| 2e046b94 | 18 | #include <linux/smp.h> |
| 1da1180c PM |
19 | #include <asm/pgalloc.h> |
| 20 | #include <asm/system.h> | |
| 21 | #include <asm/atomic.h> | |
| 22 | ||
| 23 | static int hlt_counter; | |
| 24 | void (*pm_idle)(void); | |
| 25 | void (*pm_power_off)(void); | |
| 26 | EXPORT_SYMBOL(pm_power_off); | |
| 27 | ||
| 28 | static int __init nohlt_setup(char *__unused) | |
| 29 | { | |
| 30 | hlt_counter = 1; | |
| 31 | return 1; | |
| 32 | } | |
| 33 | __setup("nohlt", nohlt_setup); | |
| 34 | ||
| 35 | static int __init hlt_setup(char *__unused) | |
| 36 | { | |
| 37 | hlt_counter = 0; | |
| 38 | return 1; | |
| 39 | } | |
| 40 | __setup("hlt", hlt_setup); | |
| 41 | ||
| e869a90e | 42 | void default_idle(void) |
| 1da1180c PM |
43 | { |
| 44 | if (!hlt_counter) { | |
| 45 | clear_thread_flag(TIF_POLLING_NRFLAG); | |
| 46 | smp_mb__after_clear_bit(); | |
| 47 | set_bl_bit(); | |
| 48 | stop_critical_timings(); | |
| 49 | ||
| 50 | while (!need_resched()) | |
| 51 | cpu_sleep(); | |
| 52 | ||
| 53 | start_critical_timings(); | |
| 54 | clear_bl_bit(); | |
| 55 | set_thread_flag(TIF_POLLING_NRFLAG); | |
| 56 | } else | |
| 57 | while (!need_resched()) | |
| 58 | cpu_relax(); | |
| 59 | } | |
| 60 | ||
| 61 | void cpu_idle(void) | |
| 62 | { | |
| 63 | set_thread_flag(TIF_POLLING_NRFLAG); | |
| 64 | ||
| 65 | /* endless idle loop with no priority at all */ | |
| 66 | while (1) { | |
| 67 | void (*idle)(void) = pm_idle; | |
| 68 | ||
| 69 | if (!idle) | |
| 70 | idle = default_idle; | |
| 71 | ||
| 72 | tick_nohz_stop_sched_tick(1); | |
| 73 | while (!need_resched()) | |
| 74 | idle(); | |
| 75 | tick_nohz_restart_sched_tick(); | |
| 76 | ||
| 77 | preempt_enable_no_resched(); | |
| 78 | schedule(); | |
| 79 | preempt_disable(); | |
| 80 | check_pgt_cache(); | |
| 81 | } | |
| 82 | } | |
| 2e046b94 PM |
83 | |
| 84 | static void do_nothing(void *unused) | |
| 85 | { | |
| 86 | } | |
| 87 | ||
| 88 | /* | |
| 89 | * cpu_idle_wait - Used to ensure that all the CPUs discard old value of | |
| 90 | * pm_idle and update to new pm_idle value. Required while changing pm_idle | |
| 91 | * handler on SMP systems. | |
| 92 | * | |
| 93 | * Caller must have changed pm_idle to the new value before the call. Old | |
| 94 | * pm_idle value will not be used by any CPU after the return of this function. | |
| 95 | */ | |
| 96 | void cpu_idle_wait(void) | |
| 97 | { | |
| 98 | smp_mb(); | |
| 99 | /* kick all the CPUs so that they exit out of pm_idle */ | |
| 100 | smp_call_function(do_nothing, NULL, 1); | |
| 101 | } | |
| 102 | EXPORT_SYMBOL_GPL(cpu_idle_wait); |