Commit | Line | Data |
---|---|---|
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> |
212bebb4 | 21 | #include <asm/plpar_wrappers.h> |
707827f3 DD |
22 | |
23 | struct cpuidle_driver pseries_idle_driver = { | |
1ca80944 DL |
24 | .name = "pseries_idle", |
25 | .owner = THIS_MODULE, | |
707827f3 DD |
26 | }; |
27 | ||
28 | #define MAX_IDLE_STATE_COUNT 2 | |
29 | ||
30 | static int max_idle_state = MAX_IDLE_STATE_COUNT - 1; | |
31 | static struct cpuidle_device __percpu *pseries_cpuidle_devices; | |
32 | static struct cpuidle_state *cpuidle_state_table; | |
33 | ||
1ca80944 | 34 | static inline void idle_loop_prolog(unsigned long *in_purr) |
707827f3 | 35 | { |
707827f3 DD |
36 | *in_purr = mfspr(SPRN_PURR); |
37 | /* | |
38 | * Indicate to the HV that we are idle. Now would be | |
39 | * a good time to find other work to dispatch. | |
40 | */ | |
41 | get_lppaca()->idle = 1; | |
42 | } | |
43 | ||
1ca80944 | 44 | static inline void idle_loop_epilog(unsigned long in_purr) |
707827f3 | 45 | { |
7ffcf8ec AB |
46 | u64 wait_cycles; |
47 | ||
48 | wait_cycles = be64_to_cpu(get_lppaca()->wait_state_cycles); | |
49 | wait_cycles += mfspr(SPRN_PURR) - in_purr; | |
50 | get_lppaca()->wait_state_cycles = cpu_to_be64(wait_cycles); | |
707827f3 | 51 | get_lppaca()->idle = 0; |
707827f3 DD |
52 | } |
53 | ||
54 | static int snooze_loop(struct cpuidle_device *dev, | |
55 | struct cpuidle_driver *drv, | |
56 | int index) | |
57 | { | |
58 | unsigned long in_purr; | |
83dac594 | 59 | int cpu = dev->cpu; |
707827f3 | 60 | |
1ca80944 | 61 | idle_loop_prolog(&in_purr); |
83dac594 DD |
62 | local_irq_enable(); |
63 | set_thread_flag(TIF_POLLING_NRFLAG); | |
707827f3 | 64 | |
83dac594 DD |
65 | while ((!need_resched()) && cpu_online(cpu)) { |
66 | ppc64_runlatch_off(); | |
67 | HMT_low(); | |
68 | HMT_very_low(); | |
707827f3 DD |
69 | } |
70 | ||
707827f3 | 71 | HMT_medium(); |
83dac594 DD |
72 | clear_thread_flag(TIF_POLLING_NRFLAG); |
73 | smp_mb(); | |
74 | ||
1ca80944 DL |
75 | idle_loop_epilog(in_purr); |
76 | ||
707827f3 DD |
77 | return index; |
78 | } | |
79 | ||
7230c564 BH |
80 | static void check_and_cede_processor(void) |
81 | { | |
82 | /* | |
be2cf20a BH |
83 | * Ensure our interrupt state is properly tracked, |
84 | * also checks if no interrupt has occurred while we | |
85 | * were soft-disabled | |
7230c564 | 86 | */ |
be2cf20a | 87 | if (prep_irq_for_idle()) { |
7230c564 | 88 | cede_processor(); |
be2cf20a BH |
89 | #ifdef CONFIG_TRACE_IRQFLAGS |
90 | /* Ensure that H_CEDE returns with IRQs on */ | |
91 | if (WARN_ON(!(mfmsr() & MSR_EE))) | |
92 | __hard_irq_enable(); | |
93 | #endif | |
94 | } | |
7230c564 BH |
95 | } |
96 | ||
707827f3 DD |
97 | static int dedicated_cede_loop(struct cpuidle_device *dev, |
98 | struct cpuidle_driver *drv, | |
99 | int index) | |
100 | { | |
101 | unsigned long in_purr; | |
707827f3 | 102 | |
1ca80944 | 103 | idle_loop_prolog(&in_purr); |
707827f3 DD |
104 | get_lppaca()->donate_dedicated_cpu = 1; |
105 | ||
106 | ppc64_runlatch_off(); | |
107 | HMT_medium(); | |
7230c564 | 108 | check_and_cede_processor(); |
707827f3 DD |
109 | |
110 | get_lppaca()->donate_dedicated_cpu = 0; | |
1ca80944 DL |
111 | |
112 | idle_loop_epilog(in_purr); | |
113 | ||
707827f3 DD |
114 | return index; |
115 | } | |
116 | ||
117 | static int shared_cede_loop(struct cpuidle_device *dev, | |
118 | struct cpuidle_driver *drv, | |
119 | int index) | |
120 | { | |
121 | unsigned long in_purr; | |
707827f3 | 122 | |
1ca80944 | 123 | idle_loop_prolog(&in_purr); |
707827f3 DD |
124 | |
125 | /* | |
126 | * Yield the processor to the hypervisor. We return if | |
127 | * an external interrupt occurs (which are driven prior | |
128 | * to returning here) or if a prod occurs from another | |
129 | * processor. When returning here, external interrupts | |
130 | * are enabled. | |
131 | */ | |
7230c564 | 132 | check_and_cede_processor(); |
707827f3 | 133 | |
1ca80944 DL |
134 | idle_loop_epilog(in_purr); |
135 | ||
707827f3 DD |
136 | return index; |
137 | } | |
138 | ||
139 | /* | |
140 | * States for dedicated partition case. | |
141 | */ | |
142 | static struct cpuidle_state dedicated_states[MAX_IDLE_STATE_COUNT] = { | |
143 | { /* Snooze */ | |
144 | .name = "snooze", | |
145 | .desc = "snooze", | |
146 | .flags = CPUIDLE_FLAG_TIME_VALID, | |
147 | .exit_latency = 0, | |
148 | .target_residency = 0, | |
149 | .enter = &snooze_loop }, | |
150 | { /* CEDE */ | |
151 | .name = "CEDE", | |
152 | .desc = "CEDE", | |
153 | .flags = CPUIDLE_FLAG_TIME_VALID, | |
83dac594 DD |
154 | .exit_latency = 10, |
155 | .target_residency = 100, | |
707827f3 DD |
156 | .enter = &dedicated_cede_loop }, |
157 | }; | |
158 | ||
159 | /* | |
160 | * States for shared partition case. | |
161 | */ | |
162 | static struct cpuidle_state shared_states[MAX_IDLE_STATE_COUNT] = { | |
163 | { /* Shared Cede */ | |
164 | .name = "Shared Cede", | |
165 | .desc = "Shared Cede", | |
166 | .flags = CPUIDLE_FLAG_TIME_VALID, | |
167 | .exit_latency = 0, | |
168 | .target_residency = 0, | |
169 | .enter = &shared_cede_loop }, | |
170 | }; | |
171 | ||
8ea959a1 DD |
172 | void update_smt_snooze_delay(int cpu, int residency) |
173 | { | |
174 | struct cpuidle_driver *drv = cpuidle_get_driver(); | |
175 | struct cpuidle_device *dev = per_cpu(cpuidle_devices, cpu); | |
176 | ||
177 | if (cpuidle_state_table != dedicated_states) | |
178 | return; | |
179 | ||
180 | if (residency < 0) { | |
181 | /* Disable the Nap state on that cpu */ | |
182 | if (dev) | |
183 | dev->states_usage[1].disable = 1; | |
184 | } else | |
185 | if (drv) | |
83dac594 | 186 | drv->states[1].target_residency = residency; |
8ea959a1 DD |
187 | } |
188 | ||
16aaaff6 DD |
189 | static int pseries_cpuidle_add_cpu_notifier(struct notifier_block *n, |
190 | unsigned long action, void *hcpu) | |
707827f3 | 191 | { |
16aaaff6 | 192 | int hotcpu = (unsigned long)hcpu; |
707827f3 | 193 | struct cpuidle_device *dev = |
16aaaff6 DD |
194 | per_cpu_ptr(pseries_cpuidle_devices, hotcpu); |
195 | ||
852d8cb1 DD |
196 | if (dev && cpuidle_get_driver()) { |
197 | switch (action) { | |
198 | case CPU_ONLINE: | |
199 | case CPU_ONLINE_FROZEN: | |
200 | cpuidle_pause_and_lock(); | |
16aaaff6 | 201 | cpuidle_enable_device(dev); |
852d8cb1 DD |
202 | cpuidle_resume_and_unlock(); |
203 | break; | |
204 | ||
205 | case CPU_DEAD: | |
206 | case CPU_DEAD_FROZEN: | |
207 | cpuidle_pause_and_lock(); | |
208 | cpuidle_disable_device(dev); | |
209 | cpuidle_resume_and_unlock(); | |
210 | break; | |
211 | ||
212 | default: | |
213 | return NOTIFY_DONE; | |
16aaaff6 | 214 | } |
707827f3 | 215 | } |
16aaaff6 | 216 | return NOTIFY_OK; |
707827f3 DD |
217 | } |
218 | ||
16aaaff6 DD |
219 | static struct notifier_block setup_hotplug_notifier = { |
220 | .notifier_call = pseries_cpuidle_add_cpu_notifier, | |
221 | }; | |
222 | ||
707827f3 DD |
223 | /* |
224 | * pseries_cpuidle_driver_init() | |
225 | */ | |
226 | static int pseries_cpuidle_driver_init(void) | |
227 | { | |
228 | int idle_state; | |
229 | struct cpuidle_driver *drv = &pseries_idle_driver; | |
230 | ||
231 | drv->state_count = 0; | |
232 | ||
233 | for (idle_state = 0; idle_state < MAX_IDLE_STATE_COUNT; ++idle_state) { | |
234 | ||
235 | if (idle_state > max_idle_state) | |
236 | break; | |
237 | ||
238 | /* is the state not enabled? */ | |
239 | if (cpuidle_state_table[idle_state].enter == NULL) | |
240 | continue; | |
241 | ||
242 | drv->states[drv->state_count] = /* structure copy */ | |
243 | cpuidle_state_table[idle_state]; | |
244 | ||
707827f3 DD |
245 | drv->state_count += 1; |
246 | } | |
247 | ||
248 | return 0; | |
249 | } | |
250 | ||
251 | /* pseries_idle_devices_uninit(void) | |
252 | * unregister cpuidle devices and de-allocate memory | |
253 | */ | |
254 | static void pseries_idle_devices_uninit(void) | |
255 | { | |
256 | int i; | |
257 | struct cpuidle_device *dev; | |
258 | ||
259 | for_each_possible_cpu(i) { | |
260 | dev = per_cpu_ptr(pseries_cpuidle_devices, i); | |
261 | cpuidle_unregister_device(dev); | |
262 | } | |
263 | ||
264 | free_percpu(pseries_cpuidle_devices); | |
265 | return; | |
266 | } | |
267 | ||
268 | /* pseries_idle_devices_init() | |
269 | * allocate, initialize and register cpuidle device | |
270 | */ | |
271 | static int pseries_idle_devices_init(void) | |
272 | { | |
273 | int i; | |
274 | struct cpuidle_driver *drv = &pseries_idle_driver; | |
275 | struct cpuidle_device *dev; | |
276 | ||
277 | pseries_cpuidle_devices = alloc_percpu(struct cpuidle_device); | |
278 | if (pseries_cpuidle_devices == NULL) | |
279 | return -ENOMEM; | |
280 | ||
281 | for_each_possible_cpu(i) { | |
282 | dev = per_cpu_ptr(pseries_cpuidle_devices, i); | |
283 | dev->state_count = drv->state_count; | |
284 | dev->cpu = i; | |
285 | if (cpuidle_register_device(dev)) { | |
286 | printk(KERN_DEBUG \ | |
287 | "cpuidle_register_device %d failed!\n", i); | |
288 | return -EIO; | |
289 | } | |
290 | } | |
291 | ||
292 | return 0; | |
293 | } | |
294 | ||
295 | /* | |
296 | * pseries_idle_probe() | |
297 | * Choose state table for shared versus dedicated partition | |
298 | */ | |
299 | static int pseries_idle_probe(void) | |
300 | { | |
301 | ||
302 | if (!firmware_has_feature(FW_FEATURE_SPLPAR)) | |
303 | return -ENODEV; | |
304 | ||
e8bb3e00 DD |
305 | if (cpuidle_disable != IDLE_NO_OVERRIDE) |
306 | return -ENODEV; | |
307 | ||
707827f3 DD |
308 | if (max_idle_state == 0) { |
309 | printk(KERN_DEBUG "pseries processor idle disabled.\n"); | |
310 | return -EPERM; | |
311 | } | |
312 | ||
f13c13a0 | 313 | if (lppaca_shared_proc(get_lppaca())) |
707827f3 DD |
314 | cpuidle_state_table = shared_states; |
315 | else | |
316 | cpuidle_state_table = dedicated_states; | |
317 | ||
318 | return 0; | |
319 | } | |
320 | ||
321 | static int __init pseries_processor_idle_init(void) | |
322 | { | |
323 | int retval; | |
324 | ||
325 | retval = pseries_idle_probe(); | |
326 | if (retval) | |
327 | return retval; | |
328 | ||
329 | pseries_cpuidle_driver_init(); | |
330 | retval = cpuidle_register_driver(&pseries_idle_driver); | |
331 | if (retval) { | |
332 | printk(KERN_DEBUG "Registration of pseries driver failed.\n"); | |
333 | return retval; | |
334 | } | |
335 | ||
336 | retval = pseries_idle_devices_init(); | |
337 | if (retval) { | |
338 | pseries_idle_devices_uninit(); | |
339 | cpuidle_unregister_driver(&pseries_idle_driver); | |
340 | return retval; | |
341 | } | |
342 | ||
16aaaff6 | 343 | register_cpu_notifier(&setup_hotplug_notifier); |
707827f3 DD |
344 | printk(KERN_DEBUG "pseries_idle_driver registered\n"); |
345 | ||
346 | return 0; | |
347 | } | |
348 | ||
349 | static void __exit pseries_processor_idle_exit(void) | |
350 | { | |
351 | ||
852d8cb1 | 352 | unregister_cpu_notifier(&setup_hotplug_notifier); |
707827f3 DD |
353 | pseries_idle_devices_uninit(); |
354 | cpuidle_unregister_driver(&pseries_idle_driver); | |
355 | ||
356 | return; | |
357 | } | |
358 | ||
359 | module_init(pseries_processor_idle_init); | |
360 | module_exit(pseries_processor_idle_exit); | |
361 | ||
362 | MODULE_AUTHOR("Deepthi Dharwar <deepthi@linux.vnet.ibm.com>"); | |
363 | MODULE_DESCRIPTION("Cpuidle driver for POWER"); | |
364 | MODULE_LICENSE("GPL"); |