GNU Linux-libre 4.4.289-gnu1
[releases.git] / drivers / cpufreq / ia64-acpi-cpufreq.c
1 /*
2  * This file provides the ACPI based P-state support. This
3  * module works with generic cpufreq infrastructure. Most of
4  * the code is based on i386 version
5  * (arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c)
6  *
7  * Copyright (C) 2005 Intel Corp
8  *      Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
9  */
10
11 #include <linux/kernel.h>
12 #include <linux/slab.h>
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/cpufreq.h>
16 #include <linux/proc_fs.h>
17 #include <linux/seq_file.h>
18 #include <asm/io.h>
19 #include <asm/uaccess.h>
20 #include <asm/pal.h>
21
22 #include <linux/acpi.h>
23 #include <acpi/processor.h>
24
25 MODULE_AUTHOR("Venkatesh Pallipadi");
26 MODULE_DESCRIPTION("ACPI Processor P-States Driver");
27 MODULE_LICENSE("GPL");
28
29
30 struct cpufreq_acpi_io {
31         struct acpi_processor_performance       acpi_data;
32         unsigned int                            resume;
33 };
34
35 static struct cpufreq_acpi_io   *acpi_io_data[NR_CPUS];
36
37 static struct cpufreq_driver acpi_cpufreq_driver;
38
39
40 static int
41 processor_set_pstate (
42         u32     value)
43 {
44         s64 retval;
45
46         pr_debug("processor_set_pstate\n");
47
48         retval = ia64_pal_set_pstate((u64)value);
49
50         if (retval) {
51                 pr_debug("Failed to set freq to 0x%x, with error 0x%lx\n",
52                         value, retval);
53                 return -ENODEV;
54         }
55         return (int)retval;
56 }
57
58
59 static int
60 processor_get_pstate (
61         u32     *value)
62 {
63         u64     pstate_index = 0;
64         s64     retval;
65
66         pr_debug("processor_get_pstate\n");
67
68         retval = ia64_pal_get_pstate(&pstate_index,
69                                      PAL_GET_PSTATE_TYPE_INSTANT);
70         *value = (u32) pstate_index;
71
72         if (retval)
73                 pr_debug("Failed to get current freq with "
74                         "error 0x%lx, idx 0x%x\n", retval, *value);
75
76         return (int)retval;
77 }
78
79
80 /* To be used only after data->acpi_data is initialized */
81 static unsigned
82 extract_clock (
83         struct cpufreq_acpi_io *data,
84         unsigned value,
85         unsigned int cpu)
86 {
87         unsigned long i;
88
89         pr_debug("extract_clock\n");
90
91         for (i = 0; i < data->acpi_data.state_count; i++) {
92                 if (value == data->acpi_data.states[i].status)
93                         return data->acpi_data.states[i].core_frequency;
94         }
95         return data->acpi_data.states[i-1].core_frequency;
96 }
97
98
99 static unsigned int
100 processor_get_freq (
101         struct cpufreq_acpi_io  *data,
102         unsigned int            cpu)
103 {
104         int                     ret = 0;
105         u32                     value = 0;
106         cpumask_t               saved_mask;
107         unsigned long           clock_freq;
108
109         pr_debug("processor_get_freq\n");
110
111         saved_mask = current->cpus_allowed;
112         set_cpus_allowed_ptr(current, cpumask_of(cpu));
113         if (smp_processor_id() != cpu)
114                 goto migrate_end;
115
116         /* processor_get_pstate gets the instantaneous frequency */
117         ret = processor_get_pstate(&value);
118
119         if (ret) {
120                 set_cpus_allowed_ptr(current, &saved_mask);
121                 printk(KERN_WARNING "get performance failed with error %d\n",
122                        ret);
123                 ret = 0;
124                 goto migrate_end;
125         }
126         clock_freq = extract_clock(data, value, cpu);
127         ret = (clock_freq*1000);
128
129 migrate_end:
130         set_cpus_allowed_ptr(current, &saved_mask);
131         return ret;
132 }
133
134
135 static int
136 processor_set_freq (
137         struct cpufreq_acpi_io  *data,
138         struct cpufreq_policy   *policy,
139         int                     state)
140 {
141         int                     ret = 0;
142         u32                     value = 0;
143         cpumask_t               saved_mask;
144         int                     retval;
145
146         pr_debug("processor_set_freq\n");
147
148         saved_mask = current->cpus_allowed;
149         set_cpus_allowed_ptr(current, cpumask_of(policy->cpu));
150         if (smp_processor_id() != policy->cpu) {
151                 retval = -EAGAIN;
152                 goto migrate_end;
153         }
154
155         if (state == data->acpi_data.state) {
156                 if (unlikely(data->resume)) {
157                         pr_debug("Called after resume, resetting to P%d\n", state);
158                         data->resume = 0;
159                 } else {
160                         pr_debug("Already at target state (P%d)\n", state);
161                         retval = 0;
162                         goto migrate_end;
163                 }
164         }
165
166         pr_debug("Transitioning from P%d to P%d\n",
167                 data->acpi_data.state, state);
168
169         /*
170          * First we write the target state's 'control' value to the
171          * control_register.
172          */
173
174         value = (u32) data->acpi_data.states[state].control;
175
176         pr_debug("Transitioning to state: 0x%08x\n", value);
177
178         ret = processor_set_pstate(value);
179         if (ret) {
180                 printk(KERN_WARNING "Transition failed with error %d\n", ret);
181                 retval = -ENODEV;
182                 goto migrate_end;
183         }
184
185         data->acpi_data.state = state;
186
187         retval = 0;
188
189 migrate_end:
190         set_cpus_allowed_ptr(current, &saved_mask);
191         return (retval);
192 }
193
194
195 static unsigned int
196 acpi_cpufreq_get (
197         unsigned int            cpu)
198 {
199         struct cpufreq_acpi_io *data = acpi_io_data[cpu];
200
201         pr_debug("acpi_cpufreq_get\n");
202
203         return processor_get_freq(data, cpu);
204 }
205
206
207 static int
208 acpi_cpufreq_target (
209         struct cpufreq_policy   *policy,
210         unsigned int index)
211 {
212         return processor_set_freq(acpi_io_data[policy->cpu], policy, index);
213 }
214
215 static int
216 acpi_cpufreq_cpu_init (
217         struct cpufreq_policy   *policy)
218 {
219         unsigned int            i;
220         unsigned int            cpu = policy->cpu;
221         struct cpufreq_acpi_io  *data;
222         unsigned int            result = 0;
223         struct cpufreq_frequency_table *freq_table;
224
225         pr_debug("acpi_cpufreq_cpu_init\n");
226
227         data = kzalloc(sizeof(*data), GFP_KERNEL);
228         if (!data)
229                 return (-ENOMEM);
230
231         acpi_io_data[cpu] = data;
232
233         result = acpi_processor_register_performance(&data->acpi_data, cpu);
234
235         if (result)
236                 goto err_free;
237
238         /* capability check */
239         if (data->acpi_data.state_count <= 1) {
240                 pr_debug("No P-States\n");
241                 result = -ENODEV;
242                 goto err_unreg;
243         }
244
245         if ((data->acpi_data.control_register.space_id !=
246                                         ACPI_ADR_SPACE_FIXED_HARDWARE) ||
247             (data->acpi_data.status_register.space_id !=
248                                         ACPI_ADR_SPACE_FIXED_HARDWARE)) {
249                 pr_debug("Unsupported address space [%d, %d]\n",
250                         (u32) (data->acpi_data.control_register.space_id),
251                         (u32) (data->acpi_data.status_register.space_id));
252                 result = -ENODEV;
253                 goto err_unreg;
254         }
255
256         /* alloc freq_table */
257         freq_table = kzalloc(sizeof(*freq_table) *
258                                    (data->acpi_data.state_count + 1),
259                                    GFP_KERNEL);
260         if (!freq_table) {
261                 result = -ENOMEM;
262                 goto err_unreg;
263         }
264
265         /* detect transition latency */
266         policy->cpuinfo.transition_latency = 0;
267         for (i=0; i<data->acpi_data.state_count; i++) {
268                 if ((data->acpi_data.states[i].transition_latency * 1000) >
269                     policy->cpuinfo.transition_latency) {
270                         policy->cpuinfo.transition_latency =
271                             data->acpi_data.states[i].transition_latency * 1000;
272                 }
273         }
274
275         /* table init */
276         for (i = 0; i <= data->acpi_data.state_count; i++)
277         {
278                 if (i < data->acpi_data.state_count) {
279                         freq_table[i].frequency =
280                               data->acpi_data.states[i].core_frequency * 1000;
281                 } else {
282                         freq_table[i].frequency = CPUFREQ_TABLE_END;
283                 }
284         }
285
286         result = cpufreq_table_validate_and_show(policy, freq_table);
287         if (result) {
288                 goto err_freqfree;
289         }
290
291         /* notify BIOS that we exist */
292         acpi_processor_notify_smm(THIS_MODULE);
293
294         printk(KERN_INFO "acpi-cpufreq: CPU%u - ACPI performance management "
295                "activated.\n", cpu);
296
297         for (i = 0; i < data->acpi_data.state_count; i++)
298                 pr_debug("     %cP%d: %d MHz, %d mW, %d uS, %d uS, 0x%x 0x%x\n",
299                         (i == data->acpi_data.state?'*':' '), i,
300                         (u32) data->acpi_data.states[i].core_frequency,
301                         (u32) data->acpi_data.states[i].power,
302                         (u32) data->acpi_data.states[i].transition_latency,
303                         (u32) data->acpi_data.states[i].bus_master_latency,
304                         (u32) data->acpi_data.states[i].status,
305                         (u32) data->acpi_data.states[i].control);
306
307         /* the first call to ->target() should result in us actually
308          * writing something to the appropriate registers. */
309         data->resume = 1;
310
311         return (result);
312
313  err_freqfree:
314         kfree(freq_table);
315  err_unreg:
316         acpi_processor_unregister_performance(cpu);
317  err_free:
318         kfree(data);
319         acpi_io_data[cpu] = NULL;
320
321         return (result);
322 }
323
324
325 static int
326 acpi_cpufreq_cpu_exit (
327         struct cpufreq_policy   *policy)
328 {
329         struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
330
331         pr_debug("acpi_cpufreq_cpu_exit\n");
332
333         if (data) {
334                 acpi_io_data[policy->cpu] = NULL;
335                 acpi_processor_unregister_performance(policy->cpu);
336                 kfree(policy->freq_table);
337                 kfree(data);
338         }
339
340         return (0);
341 }
342
343
344 static struct cpufreq_driver acpi_cpufreq_driver = {
345         .verify         = cpufreq_generic_frequency_table_verify,
346         .target_index   = acpi_cpufreq_target,
347         .get            = acpi_cpufreq_get,
348         .init           = acpi_cpufreq_cpu_init,
349         .exit           = acpi_cpufreq_cpu_exit,
350         .name           = "acpi-cpufreq",
351         .attr           = cpufreq_generic_attr,
352 };
353
354
355 static int __init
356 acpi_cpufreq_init (void)
357 {
358         pr_debug("acpi_cpufreq_init\n");
359
360         return cpufreq_register_driver(&acpi_cpufreq_driver);
361 }
362
363
364 static void __exit
365 acpi_cpufreq_exit (void)
366 {
367         pr_debug("acpi_cpufreq_exit\n");
368
369         cpufreq_unregister_driver(&acpi_cpufreq_driver);
370         return;
371 }
372
373
374 late_initcall(acpi_cpufreq_init);
375 module_exit(acpi_cpufreq_exit);
376