Commit | Line | Data |
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707827f3 DD |
1 | /* |
2 | * processor_idle - idle state cpuidle driver. | |
3 | * Adapted from drivers/idle/intel_idle.c and | |
4 | * drivers/acpi/processor_idle.c | |
5 | * | |
6 | */ | |
7 | ||
8 | #include <linux/kernel.h> | |
9 | #include <linux/module.h> | |
10 | #include <linux/init.h> | |
11 | #include <linux/moduleparam.h> | |
12 | #include <linux/cpuidle.h> | |
13 | #include <linux/cpu.h> | |
16aaaff6 | 14 | #include <linux/notifier.h> |
707827f3 DD |
15 | |
16 | #include <asm/paca.h> | |
17 | #include <asm/reg.h> | |
707827f3 DD |
18 | #include <asm/machdep.h> |
19 | #include <asm/firmware.h> | |
ae3a197e | 20 | #include <asm/runlatch.h> |
707827f3 DD |
21 | |
22 | #include "plpar_wrappers.h" | |
707827f3 DD |
23 | |
24 | struct cpuidle_driver pseries_idle_driver = { | |
1ca80944 DL |
25 | .name = "pseries_idle", |
26 | .owner = THIS_MODULE, | |
707827f3 DD |
27 | }; |
28 | ||
29 | #define MAX_IDLE_STATE_COUNT 2 | |
30 | ||
31 | static int max_idle_state = MAX_IDLE_STATE_COUNT - 1; | |
32 | static struct cpuidle_device __percpu *pseries_cpuidle_devices; | |
33 | static struct cpuidle_state *cpuidle_state_table; | |
34 | ||
1ca80944 | 35 | static inline void idle_loop_prolog(unsigned long *in_purr) |
707827f3 | 36 | { |
707827f3 DD |
37 | *in_purr = mfspr(SPRN_PURR); |
38 | /* | |
39 | * Indicate to the HV that we are idle. Now would be | |
40 | * a good time to find other work to dispatch. | |
41 | */ | |
42 | get_lppaca()->idle = 1; | |
43 | } | |
44 | ||
1ca80944 | 45 | static inline void idle_loop_epilog(unsigned long in_purr) |
707827f3 | 46 | { |
7ffcf8ec AB |
47 | u64 wait_cycles; |
48 | ||
49 | wait_cycles = be64_to_cpu(get_lppaca()->wait_state_cycles); | |
50 | wait_cycles += mfspr(SPRN_PURR) - in_purr; | |
51 | get_lppaca()->wait_state_cycles = cpu_to_be64(wait_cycles); | |
707827f3 | 52 | get_lppaca()->idle = 0; |
707827f3 DD |
53 | } |
54 | ||
55 | static int snooze_loop(struct cpuidle_device *dev, | |
56 | struct cpuidle_driver *drv, | |
57 | int index) | |
58 | { | |
59 | unsigned long in_purr; | |
83dac594 | 60 | int cpu = dev->cpu; |
707827f3 | 61 | |
1ca80944 | 62 | idle_loop_prolog(&in_purr); |
83dac594 DD |
63 | local_irq_enable(); |
64 | set_thread_flag(TIF_POLLING_NRFLAG); | |
707827f3 | 65 | |
83dac594 DD |
66 | while ((!need_resched()) && cpu_online(cpu)) { |
67 | ppc64_runlatch_off(); | |
68 | HMT_low(); | |
69 | HMT_very_low(); | |
707827f3 DD |
70 | } |
71 | ||
707827f3 | 72 | HMT_medium(); |
83dac594 DD |
73 | clear_thread_flag(TIF_POLLING_NRFLAG); |
74 | smp_mb(); | |
75 | ||
1ca80944 DL |
76 | idle_loop_epilog(in_purr); |
77 | ||
707827f3 DD |
78 | return index; |
79 | } | |
80 | ||
7230c564 BH |
81 | static void check_and_cede_processor(void) |
82 | { | |
83 | /* | |
be2cf20a BH |
84 | * Ensure our interrupt state is properly tracked, |
85 | * also checks if no interrupt has occurred while we | |
86 | * were soft-disabled | |
7230c564 | 87 | */ |
be2cf20a | 88 | if (prep_irq_for_idle()) { |
7230c564 | 89 | cede_processor(); |
be2cf20a BH |
90 | #ifdef CONFIG_TRACE_IRQFLAGS |
91 | /* Ensure that H_CEDE returns with IRQs on */ | |
92 | if (WARN_ON(!(mfmsr() & MSR_EE))) | |
93 | __hard_irq_enable(); | |
94 | #endif | |
95 | } | |
7230c564 BH |
96 | } |
97 | ||
707827f3 DD |
98 | static int dedicated_cede_loop(struct cpuidle_device *dev, |
99 | struct cpuidle_driver *drv, | |
100 | int index) | |
101 | { | |
102 | unsigned long in_purr; | |
707827f3 | 103 | |
1ca80944 | 104 | idle_loop_prolog(&in_purr); |
707827f3 DD |
105 | get_lppaca()->donate_dedicated_cpu = 1; |
106 | ||
107 | ppc64_runlatch_off(); | |
108 | HMT_medium(); | |
7230c564 | 109 | check_and_cede_processor(); |
707827f3 DD |
110 | |
111 | get_lppaca()->donate_dedicated_cpu = 0; | |
1ca80944 DL |
112 | |
113 | idle_loop_epilog(in_purr); | |
114 | ||
707827f3 DD |
115 | return index; |
116 | } | |
117 | ||
118 | static int shared_cede_loop(struct cpuidle_device *dev, | |
119 | struct cpuidle_driver *drv, | |
120 | int index) | |
121 | { | |
122 | unsigned long in_purr; | |
707827f3 | 123 | |
1ca80944 | 124 | idle_loop_prolog(&in_purr); |
707827f3 DD |
125 | |
126 | /* | |
127 | * Yield the processor to the hypervisor. We return if | |
128 | * an external interrupt occurs (which are driven prior | |
129 | * to returning here) or if a prod occurs from another | |
130 | * processor. When returning here, external interrupts | |
131 | * are enabled. | |
132 | */ | |
7230c564 | 133 | check_and_cede_processor(); |
707827f3 | 134 | |
1ca80944 DL |
135 | idle_loop_epilog(in_purr); |
136 | ||
707827f3 DD |
137 | return index; |
138 | } | |
139 | ||
140 | /* | |
141 | * States for dedicated partition case. | |
142 | */ | |
143 | static struct cpuidle_state dedicated_states[MAX_IDLE_STATE_COUNT] = { | |
144 | { /* Snooze */ | |
145 | .name = "snooze", | |
146 | .desc = "snooze", | |
147 | .flags = CPUIDLE_FLAG_TIME_VALID, | |
148 | .exit_latency = 0, | |
149 | .target_residency = 0, | |
150 | .enter = &snooze_loop }, | |
151 | { /* CEDE */ | |
152 | .name = "CEDE", | |
153 | .desc = "CEDE", | |
154 | .flags = CPUIDLE_FLAG_TIME_VALID, | |
83dac594 DD |
155 | .exit_latency = 10, |
156 | .target_residency = 100, | |
707827f3 DD |
157 | .enter = &dedicated_cede_loop }, |
158 | }; | |
159 | ||
160 | /* | |
161 | * States for shared partition case. | |
162 | */ | |
163 | static struct cpuidle_state shared_states[MAX_IDLE_STATE_COUNT] = { | |
164 | { /* Shared Cede */ | |
165 | .name = "Shared Cede", | |
166 | .desc = "Shared Cede", | |
167 | .flags = CPUIDLE_FLAG_TIME_VALID, | |
168 | .exit_latency = 0, | |
169 | .target_residency = 0, | |
170 | .enter = &shared_cede_loop }, | |
171 | }; | |
172 | ||
8ea959a1 DD |
173 | void update_smt_snooze_delay(int cpu, int residency) |
174 | { | |
175 | struct cpuidle_driver *drv = cpuidle_get_driver(); | |
176 | struct cpuidle_device *dev = per_cpu(cpuidle_devices, cpu); | |
177 | ||
178 | if (cpuidle_state_table != dedicated_states) | |
179 | return; | |
180 | ||
181 | if (residency < 0) { | |
182 | /* Disable the Nap state on that cpu */ | |
183 | if (dev) | |
184 | dev->states_usage[1].disable = 1; | |
185 | } else | |
186 | if (drv) | |
83dac594 | 187 | drv->states[1].target_residency = residency; |
8ea959a1 DD |
188 | } |
189 | ||
16aaaff6 DD |
190 | static int pseries_cpuidle_add_cpu_notifier(struct notifier_block *n, |
191 | unsigned long action, void *hcpu) | |
707827f3 | 192 | { |
16aaaff6 | 193 | int hotcpu = (unsigned long)hcpu; |
707827f3 | 194 | struct cpuidle_device *dev = |
16aaaff6 DD |
195 | per_cpu_ptr(pseries_cpuidle_devices, hotcpu); |
196 | ||
852d8cb1 DD |
197 | if (dev && cpuidle_get_driver()) { |
198 | switch (action) { | |
199 | case CPU_ONLINE: | |
200 | case CPU_ONLINE_FROZEN: | |
201 | cpuidle_pause_and_lock(); | |
16aaaff6 | 202 | cpuidle_enable_device(dev); |
852d8cb1 DD |
203 | cpuidle_resume_and_unlock(); |
204 | break; | |
205 | ||
206 | case CPU_DEAD: | |
207 | case CPU_DEAD_FROZEN: | |
208 | cpuidle_pause_and_lock(); | |
209 | cpuidle_disable_device(dev); | |
210 | cpuidle_resume_and_unlock(); | |
211 | break; | |
212 | ||
213 | default: | |
214 | return NOTIFY_DONE; | |
16aaaff6 | 215 | } |
707827f3 | 216 | } |
16aaaff6 | 217 | return NOTIFY_OK; |
707827f3 DD |
218 | } |
219 | ||
16aaaff6 DD |
220 | static struct notifier_block setup_hotplug_notifier = { |
221 | .notifier_call = pseries_cpuidle_add_cpu_notifier, | |
222 | }; | |
223 | ||
707827f3 DD |
224 | /* |
225 | * pseries_cpuidle_driver_init() | |
226 | */ | |
227 | static int pseries_cpuidle_driver_init(void) | |
228 | { | |
229 | int idle_state; | |
230 | struct cpuidle_driver *drv = &pseries_idle_driver; | |
231 | ||
232 | drv->state_count = 0; | |
233 | ||
234 | for (idle_state = 0; idle_state < MAX_IDLE_STATE_COUNT; ++idle_state) { | |
235 | ||
236 | if (idle_state > max_idle_state) | |
237 | break; | |
238 | ||
239 | /* is the state not enabled? */ | |
240 | if (cpuidle_state_table[idle_state].enter == NULL) | |
241 | continue; | |
242 | ||
243 | drv->states[drv->state_count] = /* structure copy */ | |
244 | cpuidle_state_table[idle_state]; | |
245 | ||
707827f3 DD |
246 | drv->state_count += 1; |
247 | } | |
248 | ||
249 | return 0; | |
250 | } | |
251 | ||
252 | /* pseries_idle_devices_uninit(void) | |
253 | * unregister cpuidle devices and de-allocate memory | |
254 | */ | |
255 | static void pseries_idle_devices_uninit(void) | |
256 | { | |
257 | int i; | |
258 | struct cpuidle_device *dev; | |
259 | ||
260 | for_each_possible_cpu(i) { | |
261 | dev = per_cpu_ptr(pseries_cpuidle_devices, i); | |
262 | cpuidle_unregister_device(dev); | |
263 | } | |
264 | ||
265 | free_percpu(pseries_cpuidle_devices); | |
266 | return; | |
267 | } | |
268 | ||
269 | /* pseries_idle_devices_init() | |
270 | * allocate, initialize and register cpuidle device | |
271 | */ | |
272 | static int pseries_idle_devices_init(void) | |
273 | { | |
274 | int i; | |
275 | struct cpuidle_driver *drv = &pseries_idle_driver; | |
276 | struct cpuidle_device *dev; | |
277 | ||
278 | pseries_cpuidle_devices = alloc_percpu(struct cpuidle_device); | |
279 | if (pseries_cpuidle_devices == NULL) | |
280 | return -ENOMEM; | |
281 | ||
282 | for_each_possible_cpu(i) { | |
283 | dev = per_cpu_ptr(pseries_cpuidle_devices, i); | |
284 | dev->state_count = drv->state_count; | |
285 | dev->cpu = i; | |
286 | if (cpuidle_register_device(dev)) { | |
287 | printk(KERN_DEBUG \ | |
288 | "cpuidle_register_device %d failed!\n", i); | |
289 | return -EIO; | |
290 | } | |
291 | } | |
292 | ||
293 | return 0; | |
294 | } | |
295 | ||
296 | /* | |
297 | * pseries_idle_probe() | |
298 | * Choose state table for shared versus dedicated partition | |
299 | */ | |
300 | static int pseries_idle_probe(void) | |
301 | { | |
302 | ||
303 | if (!firmware_has_feature(FW_FEATURE_SPLPAR)) | |
304 | return -ENODEV; | |
305 | ||
e8bb3e00 DD |
306 | if (cpuidle_disable != IDLE_NO_OVERRIDE) |
307 | return -ENODEV; | |
308 | ||
707827f3 DD |
309 | if (max_idle_state == 0) { |
310 | printk(KERN_DEBUG "pseries processor idle disabled.\n"); | |
311 | return -EPERM; | |
312 | } | |
313 | ||
f13c13a0 | 314 | if (lppaca_shared_proc(get_lppaca())) |
707827f3 DD |
315 | cpuidle_state_table = shared_states; |
316 | else | |
317 | cpuidle_state_table = dedicated_states; | |
318 | ||
319 | return 0; | |
320 | } | |
321 | ||
322 | static int __init pseries_processor_idle_init(void) | |
323 | { | |
324 | int retval; | |
325 | ||
326 | retval = pseries_idle_probe(); | |
327 | if (retval) | |
328 | return retval; | |
329 | ||
330 | pseries_cpuidle_driver_init(); | |
331 | retval = cpuidle_register_driver(&pseries_idle_driver); | |
332 | if (retval) { | |
333 | printk(KERN_DEBUG "Registration of pseries driver failed.\n"); | |
334 | return retval; | |
335 | } | |
336 | ||
337 | retval = pseries_idle_devices_init(); | |
338 | if (retval) { | |
339 | pseries_idle_devices_uninit(); | |
340 | cpuidle_unregister_driver(&pseries_idle_driver); | |
341 | return retval; | |
342 | } | |
343 | ||
16aaaff6 | 344 | register_cpu_notifier(&setup_hotplug_notifier); |
707827f3 DD |
345 | printk(KERN_DEBUG "pseries_idle_driver registered\n"); |
346 | ||
347 | return 0; | |
348 | } | |
349 | ||
350 | static void __exit pseries_processor_idle_exit(void) | |
351 | { | |
352 | ||
852d8cb1 | 353 | unregister_cpu_notifier(&setup_hotplug_notifier); |
707827f3 DD |
354 | pseries_idle_devices_uninit(); |
355 | cpuidle_unregister_driver(&pseries_idle_driver); | |
356 | ||
357 | return; | |
358 | } | |
359 | ||
360 | module_init(pseries_processor_idle_init); | |
361 | module_exit(pseries_processor_idle_exit); | |
362 | ||
363 | MODULE_AUTHOR("Deepthi Dharwar <deepthi@linux.vnet.ibm.com>"); | |
364 | MODULE_DESCRIPTION("Cpuidle driver for POWER"); | |
365 | MODULE_LICENSE("GPL"); |