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24 | 24 |
|
25 | 25 | static void (*sh_idle)(void); |
26 | 26 |
|
27 | | -static int hlt_counter; |
28 | | - |
29 | | -static int __init nohlt_setup(char *__unused) |
30 | | -{ |
31 | | - hlt_counter = 1; |
32 | | - return 1; |
33 | | -} |
34 | | -__setup("nohlt", nohlt_setup); |
35 | | - |
36 | | -static int __init hlt_setup(char *__unused) |
37 | | -{ |
38 | | - hlt_counter = 0; |
39 | | - return 1; |
40 | | -} |
41 | | -__setup("hlt", hlt_setup); |
42 | | - |
43 | | -static inline int hlt_works(void) |
44 | | -{ |
45 | | - return !hlt_counter; |
46 | | -} |
47 | | - |
48 | | -/* |
49 | | - * On SMP it's slightly faster (but much more power-consuming!) |
50 | | - * to poll the ->work.need_resched flag instead of waiting for the |
51 | | - * cross-CPU IPI to arrive. Use this option with caution. |
52 | | - */ |
53 | | -static void poll_idle(void) |
| 27 | +void default_idle(void) |
54 | 28 | { |
| 29 | + set_bl_bit(); |
55 | 30 | local_irq_enable(); |
56 | | - while (!need_resched()) |
57 | | - cpu_relax(); |
| 31 | + /* Isn't this racy ? */ |
| 32 | + cpu_sleep(); |
| 33 | + clear_bl_bit(); |
58 | 34 | } |
59 | 35 |
|
60 | | -void default_idle(void) |
| 36 | +void arch_cpu_idle_dead(void) |
61 | 37 | { |
62 | | - if (hlt_works()) { |
63 | | - clear_thread_flag(TIF_POLLING_NRFLAG); |
64 | | - smp_mb__after_clear_bit(); |
65 | | - |
66 | | - set_bl_bit(); |
67 | | - if (!need_resched()) { |
68 | | - local_irq_enable(); |
69 | | - cpu_sleep(); |
70 | | - } else |
71 | | - local_irq_enable(); |
72 | | - |
73 | | - set_thread_flag(TIF_POLLING_NRFLAG); |
74 | | - clear_bl_bit(); |
75 | | - } else |
76 | | - poll_idle(); |
| 38 | + play_dead(); |
77 | 39 | } |
78 | 40 |
|
79 | | -/* |
80 | | - * The idle thread. There's no useful work to be done, so just try to conserve |
81 | | - * power and have a low exit latency (ie sit in a loop waiting for somebody to |
82 | | - * say that they'd like to reschedule) |
83 | | - */ |
84 | | -void cpu_idle(void) |
| 41 | +void arch_cpu_idle(void) |
85 | 42 | { |
86 | | - unsigned int cpu = smp_processor_id(); |
87 | | - |
88 | | - set_thread_flag(TIF_POLLING_NRFLAG); |
89 | | - |
90 | | - /* endless idle loop with no priority at all */ |
91 | | - while (1) { |
92 | | - tick_nohz_idle_enter(); |
93 | | - rcu_idle_enter(); |
94 | | - |
95 | | - while (!need_resched()) { |
96 | | - check_pgt_cache(); |
97 | | - rmb(); |
98 | | - |
99 | | - if (cpu_is_offline(cpu)) |
100 | | - play_dead(); |
101 | | - |
102 | | - local_irq_disable(); |
103 | | - /* Don't trace irqs off for idle */ |
104 | | - stop_critical_timings(); |
105 | | - if (cpuidle_idle_call()) |
106 | | - sh_idle(); |
107 | | - /* |
108 | | - * Sanity check to ensure that sh_idle() returns |
109 | | - * with IRQs enabled |
110 | | - */ |
111 | | - WARN_ON(irqs_disabled()); |
112 | | - start_critical_timings(); |
113 | | - } |
114 | | - |
115 | | - rcu_idle_exit(); |
116 | | - tick_nohz_idle_exit(); |
117 | | - schedule_preempt_disabled(); |
118 | | - } |
| 43 | + if (cpuidle_idle_call()) |
| 44 | + sh_idle(); |
119 | 45 | } |
120 | 46 |
|
121 | 47 | void __init select_idle_routine(void) |
122 | 48 | { |
123 | 49 | /* |
124 | 50 | * If a platform has set its own idle routine, leave it alone. |
125 | 51 | */ |
126 | | - if (sh_idle) |
127 | | - return; |
128 | | - |
129 | | - if (hlt_works()) |
| 52 | + if (!sh_idle) |
130 | 53 | sh_idle = default_idle; |
131 | | - else |
132 | | - sh_idle = poll_idle; |
133 | 54 | } |
134 | 55 |
|
135 | 56 | void stop_this_cpu(void *unused) |
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