diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/acpi/processor_throttling.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'drivers/acpi/processor_throttling.c')
-rw-r--r-- | drivers/acpi/processor_throttling.c | 351 |
1 files changed, 351 insertions, 0 deletions
diff --git a/drivers/acpi/processor_throttling.c b/drivers/acpi/processor_throttling.c new file mode 100644 index 000000000000..be9f569d39d3 --- /dev/null +++ b/drivers/acpi/processor_throttling.c | |||
@@ -0,0 +1,351 @@ | |||
1 | /* | ||
2 | * processor_throttling.c - Throttling submodule of the ACPI processor driver | ||
3 | * | ||
4 | * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com> | ||
5 | * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com> | ||
6 | * Copyright (C) 2004 Dominik Brodowski <linux@brodo.de> | ||
7 | * Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> | ||
8 | * - Added processor hotplug support | ||
9 | * | ||
10 | * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | ||
11 | * | ||
12 | * This program is free software; you can redistribute it and/or modify | ||
13 | * it under the terms of the GNU General Public License as published by | ||
14 | * the Free Software Foundation; either version 2 of the License, or (at | ||
15 | * your option) any later version. | ||
16 | * | ||
17 | * This program is distributed in the hope that it will be useful, but | ||
18 | * WITHOUT ANY WARRANTY; without even the implied warranty of | ||
19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | ||
20 | * General Public License for more details. | ||
21 | * | ||
22 | * You should have received a copy of the GNU General Public License along | ||
23 | * with this program; if not, write to the Free Software Foundation, Inc., | ||
24 | * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. | ||
25 | * | ||
26 | * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | ||
27 | */ | ||
28 | |||
29 | #include <linux/kernel.h> | ||
30 | #include <linux/module.h> | ||
31 | #include <linux/init.h> | ||
32 | #include <linux/cpufreq.h> | ||
33 | #include <linux/proc_fs.h> | ||
34 | #include <linux/seq_file.h> | ||
35 | |||
36 | #include <asm/io.h> | ||
37 | #include <asm/uaccess.h> | ||
38 | |||
39 | #include <acpi/acpi_bus.h> | ||
40 | #include <acpi/processor.h> | ||
41 | |||
42 | #define ACPI_PROCESSOR_COMPONENT 0x01000000 | ||
43 | #define ACPI_PROCESSOR_CLASS "processor" | ||
44 | #define ACPI_PROCESSOR_DRIVER_NAME "ACPI Processor Driver" | ||
45 | #define _COMPONENT ACPI_PROCESSOR_COMPONENT | ||
46 | ACPI_MODULE_NAME ("acpi_processor") | ||
47 | |||
48 | |||
49 | /* -------------------------------------------------------------------------- | ||
50 | Throttling Control | ||
51 | -------------------------------------------------------------------------- */ | ||
52 | |||
53 | static int | ||
54 | acpi_processor_get_throttling ( | ||
55 | struct acpi_processor *pr) | ||
56 | { | ||
57 | int state = 0; | ||
58 | u32 value = 0; | ||
59 | u32 duty_mask = 0; | ||
60 | u32 duty_value = 0; | ||
61 | |||
62 | ACPI_FUNCTION_TRACE("acpi_processor_get_throttling"); | ||
63 | |||
64 | if (!pr) | ||
65 | return_VALUE(-EINVAL); | ||
66 | |||
67 | if (!pr->flags.throttling) | ||
68 | return_VALUE(-ENODEV); | ||
69 | |||
70 | pr->throttling.state = 0; | ||
71 | |||
72 | duty_mask = pr->throttling.state_count - 1; | ||
73 | |||
74 | duty_mask <<= pr->throttling.duty_offset; | ||
75 | |||
76 | local_irq_disable(); | ||
77 | |||
78 | value = inl(pr->throttling.address); | ||
79 | |||
80 | /* | ||
81 | * Compute the current throttling state when throttling is enabled | ||
82 | * (bit 4 is on). | ||
83 | */ | ||
84 | if (value & 0x10) { | ||
85 | duty_value = value & duty_mask; | ||
86 | duty_value >>= pr->throttling.duty_offset; | ||
87 | |||
88 | if (duty_value) | ||
89 | state = pr->throttling.state_count-duty_value; | ||
90 | } | ||
91 | |||
92 | pr->throttling.state = state; | ||
93 | |||
94 | local_irq_enable(); | ||
95 | |||
96 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, | ||
97 | "Throttling state is T%d (%d%% throttling applied)\n", | ||
98 | state, pr->throttling.states[state].performance)); | ||
99 | |||
100 | return_VALUE(0); | ||
101 | } | ||
102 | |||
103 | |||
104 | int acpi_processor_set_throttling ( | ||
105 | struct acpi_processor *pr, | ||
106 | int state) | ||
107 | { | ||
108 | u32 value = 0; | ||
109 | u32 duty_mask = 0; | ||
110 | u32 duty_value = 0; | ||
111 | |||
112 | ACPI_FUNCTION_TRACE("acpi_processor_set_throttling"); | ||
113 | |||
114 | if (!pr) | ||
115 | return_VALUE(-EINVAL); | ||
116 | |||
117 | if ((state < 0) || (state > (pr->throttling.state_count - 1))) | ||
118 | return_VALUE(-EINVAL); | ||
119 | |||
120 | if (!pr->flags.throttling) | ||
121 | return_VALUE(-ENODEV); | ||
122 | |||
123 | if (state == pr->throttling.state) | ||
124 | return_VALUE(0); | ||
125 | |||
126 | /* | ||
127 | * Calculate the duty_value and duty_mask. | ||
128 | */ | ||
129 | if (state) { | ||
130 | duty_value = pr->throttling.state_count - state; | ||
131 | |||
132 | duty_value <<= pr->throttling.duty_offset; | ||
133 | |||
134 | /* Used to clear all duty_value bits */ | ||
135 | duty_mask = pr->throttling.state_count - 1; | ||
136 | |||
137 | duty_mask <<= acpi_fadt.duty_offset; | ||
138 | duty_mask = ~duty_mask; | ||
139 | } | ||
140 | |||
141 | local_irq_disable(); | ||
142 | |||
143 | /* | ||
144 | * Disable throttling by writing a 0 to bit 4. Note that we must | ||
145 | * turn it off before you can change the duty_value. | ||
146 | */ | ||
147 | value = inl(pr->throttling.address); | ||
148 | if (value & 0x10) { | ||
149 | value &= 0xFFFFFFEF; | ||
150 | outl(value, pr->throttling.address); | ||
151 | } | ||
152 | |||
153 | /* | ||
154 | * Write the new duty_value and then enable throttling. Note | ||
155 | * that a state value of 0 leaves throttling disabled. | ||
156 | */ | ||
157 | if (state) { | ||
158 | value &= duty_mask; | ||
159 | value |= duty_value; | ||
160 | outl(value, pr->throttling.address); | ||
161 | |||
162 | value |= 0x00000010; | ||
163 | outl(value, pr->throttling.address); | ||
164 | } | ||
165 | |||
166 | pr->throttling.state = state; | ||
167 | |||
168 | local_irq_enable(); | ||
169 | |||
170 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, | ||
171 | "Throttling state set to T%d (%d%%)\n", state, | ||
172 | (pr->throttling.states[state].performance?pr->throttling.states[state].performance/10:0))); | ||
173 | |||
174 | return_VALUE(0); | ||
175 | } | ||
176 | |||
177 | |||
178 | int | ||
179 | acpi_processor_get_throttling_info ( | ||
180 | struct acpi_processor *pr) | ||
181 | { | ||
182 | int result = 0; | ||
183 | int step = 0; | ||
184 | int i = 0; | ||
185 | |||
186 | ACPI_FUNCTION_TRACE("acpi_processor_get_throttling_info"); | ||
187 | |||
188 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, | ||
189 | "pblk_address[0x%08x] duty_offset[%d] duty_width[%d]\n", | ||
190 | pr->throttling.address, | ||
191 | pr->throttling.duty_offset, | ||
192 | pr->throttling.duty_width)); | ||
193 | |||
194 | if (!pr) | ||
195 | return_VALUE(-EINVAL); | ||
196 | |||
197 | /* TBD: Support ACPI 2.0 objects */ | ||
198 | |||
199 | if (!pr->throttling.address) { | ||
200 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling register\n")); | ||
201 | return_VALUE(0); | ||
202 | } | ||
203 | else if (!pr->throttling.duty_width) { | ||
204 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling states\n")); | ||
205 | return_VALUE(0); | ||
206 | } | ||
207 | /* TBD: Support duty_cycle values that span bit 4. */ | ||
208 | else if ((pr->throttling.duty_offset | ||
209 | + pr->throttling.duty_width) > 4) { | ||
210 | ACPI_DEBUG_PRINT((ACPI_DB_WARN, "duty_cycle spans bit 4\n")); | ||
211 | return_VALUE(0); | ||
212 | } | ||
213 | |||
214 | /* | ||
215 | * PIIX4 Errata: We don't support throttling on the original PIIX4. | ||
216 | * This shouldn't be an issue as few (if any) mobile systems ever | ||
217 | * used this part. | ||
218 | */ | ||
219 | if (errata.piix4.throttle) { | ||
220 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, | ||
221 | "Throttling not supported on PIIX4 A- or B-step\n")); | ||
222 | return_VALUE(0); | ||
223 | } | ||
224 | |||
225 | pr->throttling.state_count = 1 << acpi_fadt.duty_width; | ||
226 | |||
227 | /* | ||
228 | * Compute state values. Note that throttling displays a linear power/ | ||
229 | * performance relationship (at 50% performance the CPU will consume | ||
230 | * 50% power). Values are in 1/10th of a percent to preserve accuracy. | ||
231 | */ | ||
232 | |||
233 | step = (1000 / pr->throttling.state_count); | ||
234 | |||
235 | for (i=0; i<pr->throttling.state_count; i++) { | ||
236 | pr->throttling.states[i].performance = step * i; | ||
237 | pr->throttling.states[i].power = step * i; | ||
238 | } | ||
239 | |||
240 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n", | ||
241 | pr->throttling.state_count)); | ||
242 | |||
243 | pr->flags.throttling = 1; | ||
244 | |||
245 | /* | ||
246 | * Disable throttling (if enabled). We'll let subsequent policy (e.g. | ||
247 | * thermal) decide to lower performance if it so chooses, but for now | ||
248 | * we'll crank up the speed. | ||
249 | */ | ||
250 | |||
251 | result = acpi_processor_get_throttling(pr); | ||
252 | if (result) | ||
253 | goto end; | ||
254 | |||
255 | if (pr->throttling.state) { | ||
256 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Disabling throttling (was T%d)\n", | ||
257 | pr->throttling.state)); | ||
258 | result = acpi_processor_set_throttling(pr, 0); | ||
259 | if (result) | ||
260 | goto end; | ||
261 | } | ||
262 | |||
263 | end: | ||
264 | if (result) | ||
265 | pr->flags.throttling = 0; | ||
266 | |||
267 | return_VALUE(result); | ||
268 | } | ||
269 | |||
270 | |||
271 | /* proc interface */ | ||
272 | |||
273 | static int acpi_processor_throttling_seq_show(struct seq_file *seq, void *offset) | ||
274 | { | ||
275 | struct acpi_processor *pr = (struct acpi_processor *)seq->private; | ||
276 | int i = 0; | ||
277 | int result = 0; | ||
278 | |||
279 | ACPI_FUNCTION_TRACE("acpi_processor_throttling_seq_show"); | ||
280 | |||
281 | if (!pr) | ||
282 | goto end; | ||
283 | |||
284 | if (!(pr->throttling.state_count > 0)) { | ||
285 | seq_puts(seq, "<not supported>\n"); | ||
286 | goto end; | ||
287 | } | ||
288 | |||
289 | result = acpi_processor_get_throttling(pr); | ||
290 | |||
291 | if (result) { | ||
292 | seq_puts(seq, "Could not determine current throttling state.\n"); | ||
293 | goto end; | ||
294 | } | ||
295 | |||
296 | seq_printf(seq, "state count: %d\n" | ||
297 | "active state: T%d\n", | ||
298 | pr->throttling.state_count, | ||
299 | pr->throttling.state); | ||
300 | |||
301 | seq_puts(seq, "states:\n"); | ||
302 | for (i = 0; i < pr->throttling.state_count; i++) | ||
303 | seq_printf(seq, " %cT%d: %02d%%\n", | ||
304 | (i == pr->throttling.state?'*':' '), i, | ||
305 | (pr->throttling.states[i].performance?pr->throttling.states[i].performance/10:0)); | ||
306 | |||
307 | end: | ||
308 | return_VALUE(0); | ||
309 | } | ||
310 | |||
311 | static int acpi_processor_throttling_open_fs(struct inode *inode, struct file *file) | ||
312 | { | ||
313 | return single_open(file, acpi_processor_throttling_seq_show, | ||
314 | PDE(inode)->data); | ||
315 | } | ||
316 | |||
317 | ssize_t acpi_processor_write_throttling ( | ||
318 | struct file *file, | ||
319 | const char __user *buffer, | ||
320 | size_t count, | ||
321 | loff_t *data) | ||
322 | { | ||
323 | int result = 0; | ||
324 | struct seq_file *m = (struct seq_file *)file->private_data; | ||
325 | struct acpi_processor *pr = (struct acpi_processor *)m->private; | ||
326 | char state_string[12] = {'\0'}; | ||
327 | |||
328 | ACPI_FUNCTION_TRACE("acpi_processor_write_throttling"); | ||
329 | |||
330 | if (!pr || (count > sizeof(state_string) - 1)) | ||
331 | return_VALUE(-EINVAL); | ||
332 | |||
333 | if (copy_from_user(state_string, buffer, count)) | ||
334 | return_VALUE(-EFAULT); | ||
335 | |||
336 | state_string[count] = '\0'; | ||
337 | |||
338 | result = acpi_processor_set_throttling(pr, | ||
339 | simple_strtoul(state_string, NULL, 0)); | ||
340 | if (result) | ||
341 | return_VALUE(result); | ||
342 | |||
343 | return_VALUE(count); | ||
344 | } | ||
345 | |||
346 | struct file_operations acpi_processor_throttling_fops = { | ||
347 | .open = acpi_processor_throttling_open_fs, | ||
348 | .read = seq_read, | ||
349 | .llseek = seq_lseek, | ||
350 | .release = single_release, | ||
351 | }; | ||