Commit | Line | Data |
---|---|---|
4f86d3a8 LB |
1 | /* |
2 | * driver.c - driver support | |
3 | * | |
4 | * (C) 2006-2007 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> | |
5 | * Shaohua Li <shaohua.li@intel.com> | |
6 | * Adam Belay <abelay@novell.com> | |
7 | * | |
8 | * This code is licenced under the GPL. | |
9 | */ | |
10 | ||
11 | #include <linux/mutex.h> | |
12 | #include <linux/module.h> | |
13 | #include <linux/cpuidle.h> | |
14 | ||
15 | #include "cpuidle.h" | |
16 | ||
4f86d3a8 LB |
17 | DEFINE_SPINLOCK(cpuidle_driver_lock); |
18 | ||
bf4d1b5d DL |
19 | static void __cpuidle_set_cpu_driver(struct cpuidle_driver *drv, int cpu); |
20 | static struct cpuidle_driver * __cpuidle_get_cpu_driver(int cpu); | |
21 | ||
13dd52f1 DL |
22 | static void __cpuidle_driver_init(struct cpuidle_driver *drv) |
23 | { | |
24 | drv->refcnt = 0; | |
13dd52f1 DL |
25 | } |
26 | ||
bf4d1b5d | 27 | static int __cpuidle_register_driver(struct cpuidle_driver *drv, int cpu) |
4f86d3a8 | 28 | { |
fc850f39 | 29 | if (!drv || !drv->state_count) |
4f86d3a8 LB |
30 | return -EINVAL; |
31 | ||
62027aea LB |
32 | if (cpuidle_disabled()) |
33 | return -ENODEV; | |
34 | ||
bf4d1b5d | 35 | if (__cpuidle_get_cpu_driver(cpu)) |
4f86d3a8 | 36 | return -EBUSY; |
ed953472 | 37 | |
13dd52f1 | 38 | __cpuidle_driver_init(drv); |
ed953472 | 39 | |
bf4d1b5d | 40 | __cpuidle_set_cpu_driver(drv, cpu); |
42f67f2a | 41 | |
13dd52f1 DL |
42 | return 0; |
43 | } | |
44 | ||
bf4d1b5d | 45 | static void __cpuidle_unregister_driver(struct cpuidle_driver *drv, int cpu) |
13dd52f1 | 46 | { |
bf4d1b5d | 47 | if (drv != __cpuidle_get_cpu_driver(cpu)) |
13dd52f1 DL |
48 | return; |
49 | ||
50 | if (!WARN_ON(drv->refcnt > 0)) | |
bf4d1b5d DL |
51 | __cpuidle_set_cpu_driver(NULL, cpu); |
52 | } | |
53 | ||
54 | #ifdef CONFIG_CPU_IDLE_MULTIPLE_DRIVERS | |
55 | ||
56 | static DEFINE_PER_CPU(struct cpuidle_driver *, cpuidle_drivers); | |
57 | ||
58 | static void __cpuidle_set_cpu_driver(struct cpuidle_driver *drv, int cpu) | |
59 | { | |
60 | per_cpu(cpuidle_drivers, cpu) = drv; | |
61 | } | |
62 | ||
63 | static struct cpuidle_driver *__cpuidle_get_cpu_driver(int cpu) | |
64 | { | |
65 | return per_cpu(cpuidle_drivers, cpu); | |
66 | } | |
67 | ||
68 | static void __cpuidle_unregister_all_cpu_driver(struct cpuidle_driver *drv) | |
69 | { | |
70 | int cpu; | |
71 | for_each_present_cpu(cpu) | |
72 | __cpuidle_unregister_driver(drv, cpu); | |
73 | } | |
74 | ||
75 | static int __cpuidle_register_all_cpu_driver(struct cpuidle_driver *drv) | |
76 | { | |
77 | int ret = 0; | |
78 | int i, cpu; | |
79 | ||
80 | for_each_present_cpu(cpu) { | |
81 | ret = __cpuidle_register_driver(drv, cpu); | |
82 | if (ret) | |
83 | break; | |
84 | } | |
85 | ||
86 | if (ret) | |
87 | for_each_present_cpu(i) { | |
88 | if (i == cpu) | |
89 | break; | |
90 | __cpuidle_unregister_driver(drv, i); | |
91 | } | |
92 | ||
93 | ||
94 | return ret; | |
95 | } | |
96 | ||
97 | int cpuidle_register_cpu_driver(struct cpuidle_driver *drv, int cpu) | |
98 | { | |
99 | int ret; | |
100 | ||
101 | spin_lock(&cpuidle_driver_lock); | |
102 | ret = __cpuidle_register_driver(drv, cpu); | |
103 | spin_unlock(&cpuidle_driver_lock); | |
104 | ||
105 | return ret; | |
106 | } | |
107 | ||
108 | void cpuidle_unregister_cpu_driver(struct cpuidle_driver *drv, int cpu) | |
109 | { | |
110 | spin_lock(&cpuidle_driver_lock); | |
111 | __cpuidle_unregister_driver(drv, cpu); | |
112 | spin_unlock(&cpuidle_driver_lock); | |
13dd52f1 | 113 | } |
ed953472 | 114 | |
13dd52f1 DL |
115 | /** |
116 | * cpuidle_register_driver - registers a driver | |
117 | * @drv: the driver | |
118 | */ | |
119 | int cpuidle_register_driver(struct cpuidle_driver *drv) | |
120 | { | |
121 | int ret; | |
122 | ||
123 | spin_lock(&cpuidle_driver_lock); | |
bf4d1b5d | 124 | ret = __cpuidle_register_all_cpu_driver(drv); |
4f86d3a8 LB |
125 | spin_unlock(&cpuidle_driver_lock); |
126 | ||
13dd52f1 | 127 | return ret; |
4f86d3a8 | 128 | } |
4f86d3a8 LB |
129 | EXPORT_SYMBOL_GPL(cpuidle_register_driver); |
130 | ||
752138df | 131 | /** |
bf4d1b5d DL |
132 | * cpuidle_unregister_driver - unregisters a driver |
133 | * @drv: the driver | |
752138df | 134 | */ |
bf4d1b5d DL |
135 | void cpuidle_unregister_driver(struct cpuidle_driver *drv) |
136 | { | |
137 | spin_lock(&cpuidle_driver_lock); | |
138 | __cpuidle_unregister_all_cpu_driver(drv); | |
139 | spin_unlock(&cpuidle_driver_lock); | |
140 | } | |
141 | EXPORT_SYMBOL_GPL(cpuidle_unregister_driver); | |
142 | ||
143 | #else | |
144 | ||
145 | static struct cpuidle_driver *cpuidle_curr_driver; | |
146 | ||
147 | static inline void __cpuidle_set_cpu_driver(struct cpuidle_driver *drv, int cpu) | |
148 | { | |
149 | cpuidle_curr_driver = drv; | |
150 | } | |
151 | ||
152 | static inline struct cpuidle_driver *__cpuidle_get_cpu_driver(int cpu) | |
752138df LB |
153 | { |
154 | return cpuidle_curr_driver; | |
155 | } | |
bf4d1b5d DL |
156 | |
157 | /** | |
158 | * cpuidle_register_driver - registers a driver | |
159 | * @drv: the driver | |
160 | */ | |
161 | int cpuidle_register_driver(struct cpuidle_driver *drv) | |
162 | { | |
163 | int ret, cpu; | |
164 | ||
165 | cpu = get_cpu(); | |
166 | spin_lock(&cpuidle_driver_lock); | |
167 | ret = __cpuidle_register_driver(drv, cpu); | |
168 | spin_unlock(&cpuidle_driver_lock); | |
169 | put_cpu(); | |
170 | ||
171 | return ret; | |
172 | } | |
173 | EXPORT_SYMBOL_GPL(cpuidle_register_driver); | |
752138df | 174 | |
4f86d3a8 LB |
175 | /** |
176 | * cpuidle_unregister_driver - unregisters a driver | |
177 | * @drv: the driver | |
178 | */ | |
179 | void cpuidle_unregister_driver(struct cpuidle_driver *drv) | |
180 | { | |
bf4d1b5d DL |
181 | int cpu; |
182 | ||
183 | cpu = get_cpu(); | |
4f86d3a8 | 184 | spin_lock(&cpuidle_driver_lock); |
bf4d1b5d | 185 | __cpuidle_unregister_driver(drv, cpu); |
4f86d3a8 | 186 | spin_unlock(&cpuidle_driver_lock); |
bf4d1b5d | 187 | put_cpu(); |
4f86d3a8 | 188 | } |
4f86d3a8 | 189 | EXPORT_SYMBOL_GPL(cpuidle_unregister_driver); |
bf4d1b5d DL |
190 | #endif |
191 | ||
192 | /** | |
193 | * cpuidle_get_driver - return the current driver | |
194 | */ | |
195 | struct cpuidle_driver *cpuidle_get_driver(void) | |
196 | { | |
197 | struct cpuidle_driver *drv; | |
198 | int cpu; | |
199 | ||
200 | cpu = get_cpu(); | |
201 | drv = __cpuidle_get_cpu_driver(cpu); | |
202 | put_cpu(); | |
203 | ||
204 | return drv; | |
205 | } | |
206 | EXPORT_SYMBOL_GPL(cpuidle_get_driver); | |
207 | ||
208 | /** | |
209 | * cpuidle_get_cpu_driver - return the driver tied with a cpu | |
210 | */ | |
211 | struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev) | |
212 | { | |
bf4d1b5d DL |
213 | if (!dev) |
214 | return NULL; | |
215 | ||
ac34d7c8 | 216 | return __cpuidle_get_cpu_driver(dev->cpu); |
bf4d1b5d DL |
217 | } |
218 | EXPORT_SYMBOL_GPL(cpuidle_get_cpu_driver); | |
6e797a07 RW |
219 | |
220 | struct cpuidle_driver *cpuidle_driver_ref(void) | |
221 | { | |
222 | struct cpuidle_driver *drv; | |
223 | ||
224 | spin_lock(&cpuidle_driver_lock); | |
225 | ||
13dd52f1 | 226 | drv = cpuidle_get_driver(); |
42f67f2a | 227 | drv->refcnt++; |
6e797a07 RW |
228 | |
229 | spin_unlock(&cpuidle_driver_lock); | |
230 | return drv; | |
231 | } | |
232 | ||
233 | void cpuidle_driver_unref(void) | |
234 | { | |
13dd52f1 | 235 | struct cpuidle_driver *drv = cpuidle_get_driver(); |
42f67f2a | 236 | |
6e797a07 RW |
237 | spin_lock(&cpuidle_driver_lock); |
238 | ||
42f67f2a DL |
239 | if (drv && !WARN_ON(drv->refcnt <= 0)) |
240 | drv->refcnt--; | |
6e797a07 RW |
241 | |
242 | spin_unlock(&cpuidle_driver_lock); | |
243 | } |