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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/i386/kernel/cpu/cpufreq/speedstep-smi.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 'arch/i386/kernel/cpu/cpufreq/speedstep-smi.c')
-rw-r--r--arch/i386/kernel/cpu/cpufreq/speedstep-smi.c424
1 files changed, 424 insertions, 0 deletions
diff --git a/arch/i386/kernel/cpu/cpufreq/speedstep-smi.c b/arch/i386/kernel/cpu/cpufreq/speedstep-smi.c
new file mode 100644
index 000000000000..79440b3f087e
--- /dev/null
+++ b/arch/i386/kernel/cpu/cpufreq/speedstep-smi.c
@@ -0,0 +1,424 @@
1/*
2 * Intel SpeedStep SMI driver.
3 *
4 * (C) 2003 Hiroshi Miura <miura@da-cha.org>
5 *
6 * Licensed under the terms of the GNU GPL License version 2.
7 *
8 */
9
10
11/*********************************************************************
12 * SPEEDSTEP - DEFINITIONS *
13 *********************************************************************/
14
15#include <linux/kernel.h>
16#include <linux/module.h>
17#include <linux/moduleparam.h>
18#include <linux/init.h>
19#include <linux/cpufreq.h>
20#include <linux/pci.h>
21#include <linux/slab.h>
22#include <linux/delay.h>
23#include <asm/ist.h>
24
25#include "speedstep-lib.h"
26
27/* speedstep system management interface port/command.
28 *
29 * These parameters are got from IST-SMI BIOS call.
30 * If user gives it, these are used.
31 *
32 */
33static int smi_port = 0;
34static int smi_cmd = 0;
35static unsigned int smi_sig = 0;
36
37/* info about the processor */
38static unsigned int speedstep_processor = 0;
39
40/*
41 * There are only two frequency states for each processor. Values
42 * are in kHz for the time being.
43 */
44static struct cpufreq_frequency_table speedstep_freqs[] = {
45 {SPEEDSTEP_HIGH, 0},
46 {SPEEDSTEP_LOW, 0},
47 {0, CPUFREQ_TABLE_END},
48};
49
50#define GET_SPEEDSTEP_OWNER 0
51#define GET_SPEEDSTEP_STATE 1
52#define SET_SPEEDSTEP_STATE 2
53#define GET_SPEEDSTEP_FREQS 4
54
55/* how often shall the SMI call be tried if it failed, e.g. because
56 * of DMA activity going on? */
57#define SMI_TRIES 5
58
59#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "speedstep-smi", msg)
60
61/**
62 * speedstep_smi_ownership
63 */
64static int speedstep_smi_ownership (void)
65{
66 u32 command, result, magic;
67 u32 function = GET_SPEEDSTEP_OWNER;
68 unsigned char magic_data[] = "Copyright (c) 1999 Intel Corporation";
69
70 command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff);
71 magic = virt_to_phys(magic_data);
72
73 dprintk("trying to obtain ownership with command %x at port %x\n", command, smi_port);
74
75 __asm__ __volatile__(
76 "out %%al, (%%dx)\n"
77 : "=D" (result)
78 : "a" (command), "b" (function), "c" (0), "d" (smi_port), "D" (0), "S" (magic)
79 );
80
81 dprintk("result is %x\n", result);
82
83 return result;
84}
85
86/**
87 * speedstep_smi_get_freqs - get SpeedStep preferred & current freq.
88 * @low: the low frequency value is placed here
89 * @high: the high frequency value is placed here
90 *
91 * Only available on later SpeedStep-enabled systems, returns false results or
92 * even hangs [cf. bugme.osdl.org # 1422] on earlier systems. Empirical testing
93 * shows that the latter occurs if !(ist_info.event & 0xFFFF).
94 */
95static int speedstep_smi_get_freqs (unsigned int *low, unsigned int *high)
96{
97 u32 command, result = 0, edi, high_mhz, low_mhz;
98 u32 state=0;
99 u32 function = GET_SPEEDSTEP_FREQS;
100
101 if (!(ist_info.event & 0xFFFF)) {
102 dprintk("bug #1422 -- can't read freqs from BIOS\n", result);
103 return -ENODEV;
104 }
105
106 command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff);
107
108 dprintk("trying to determine frequencies with command %x at port %x\n", command, smi_port);
109
110 __asm__ __volatile__("movl $0, %%edi\n"
111 "out %%al, (%%dx)\n"
112 : "=a" (result), "=b" (high_mhz), "=c" (low_mhz), "=d" (state), "=D" (edi)
113 : "a" (command), "b" (function), "c" (state), "d" (smi_port), "S" (0)
114 );
115
116 dprintk("result %x, low_freq %u, high_freq %u\n", result, low_mhz, high_mhz);
117
118 /* abort if results are obviously incorrect... */
119 if ((high_mhz + low_mhz) < 600)
120 return -EINVAL;
121
122 *high = high_mhz * 1000;
123 *low = low_mhz * 1000;
124
125 return result;
126}
127
128/**
129 * speedstep_get_state - set the SpeedStep state
130 * @state: processor frequency state (SPEEDSTEP_LOW or SPEEDSTEP_HIGH)
131 *
132 */
133static int speedstep_get_state (void)
134{
135 u32 function=GET_SPEEDSTEP_STATE;
136 u32 result, state, edi, command;
137
138 command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff);
139
140 dprintk("trying to determine current setting with command %x at port %x\n", command, smi_port);
141
142 __asm__ __volatile__("movl $0, %%edi\n"
143 "out %%al, (%%dx)\n"
144 : "=a" (result), "=b" (state), "=D" (edi)
145 : "a" (command), "b" (function), "c" (0), "d" (smi_port), "S" (0)
146 );
147
148 dprintk("state is %x, result is %x\n", state, result);
149
150 return (state & 1);
151}
152
153
154/**
155 * speedstep_set_state - set the SpeedStep state
156 * @state: new processor frequency state (SPEEDSTEP_LOW or SPEEDSTEP_HIGH)
157 *
158 */
159static void speedstep_set_state (unsigned int state)
160{
161 unsigned int result = 0, command, new_state;
162 unsigned long flags;
163 unsigned int function=SET_SPEEDSTEP_STATE;
164 unsigned int retry = 0;
165
166 if (state > 0x1)
167 return;
168
169 /* Disable IRQs */
170 local_irq_save(flags);
171
172 command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff);
173
174 dprintk("trying to set frequency to state %u with command %x at port %x\n", state, command, smi_port);
175
176 do {
177 if (retry) {
178 dprintk("retry %u, previous result %u, waiting...\n", retry, result);
179 mdelay(retry * 50);
180 }
181 retry++;
182 __asm__ __volatile__(
183 "movl $0, %%edi\n"
184 "out %%al, (%%dx)\n"
185 : "=b" (new_state), "=D" (result)
186 : "a" (command), "b" (function), "c" (state), "d" (smi_port), "S" (0)
187 );
188 } while ((new_state != state) && (retry <= SMI_TRIES));
189
190 /* enable IRQs */
191 local_irq_restore(flags);
192
193 if (new_state == state) {
194 dprintk("change to %u MHz succeeded after %u tries with result %u\n", (speedstep_freqs[new_state].frequency / 1000), retry, result);
195 } else {
196 printk(KERN_ERR "cpufreq: change failed with new_state %u and result %u\n", new_state, result);
197 }
198
199 return;
200}
201
202
203/**
204 * speedstep_target - set a new CPUFreq policy
205 * @policy: new policy
206 * @target_freq: new freq
207 * @relation:
208 *
209 * Sets a new CPUFreq policy/freq.
210 */
211static int speedstep_target (struct cpufreq_policy *policy,
212 unsigned int target_freq, unsigned int relation)
213{
214 unsigned int newstate = 0;
215 struct cpufreq_freqs freqs;
216
217 if (cpufreq_frequency_table_target(policy, &speedstep_freqs[0], target_freq, relation, &newstate))
218 return -EINVAL;
219
220 freqs.old = speedstep_freqs[speedstep_get_state()].frequency;
221 freqs.new = speedstep_freqs[newstate].frequency;
222 freqs.cpu = 0; /* speedstep.c is UP only driver */
223
224 if (freqs.old == freqs.new)
225 return 0;
226
227 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
228 speedstep_set_state(newstate);
229 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
230
231 return 0;
232}
233
234
235/**
236 * speedstep_verify - verifies a new CPUFreq policy
237 * @policy: new policy
238 *
239 * Limit must be within speedstep_low_freq and speedstep_high_freq, with
240 * at least one border included.
241 */
242static int speedstep_verify (struct cpufreq_policy *policy)
243{
244 return cpufreq_frequency_table_verify(policy, &speedstep_freqs[0]);
245}
246
247
248static int speedstep_cpu_init(struct cpufreq_policy *policy)
249{
250 int result;
251 unsigned int speed,state;
252
253 /* capability check */
254 if (policy->cpu != 0)
255 return -ENODEV;
256
257 result = speedstep_smi_ownership();
258 if (result) {
259 dprintk("fails in aquiring ownership of a SMI interface.\n");
260 return -EINVAL;
261 }
262
263 /* detect low and high frequency */
264 result = speedstep_smi_get_freqs(&speedstep_freqs[SPEEDSTEP_LOW].frequency,
265 &speedstep_freqs[SPEEDSTEP_HIGH].frequency);
266 if (result) {
267 /* fall back to speedstep_lib.c dection mechanism: try both states out */
268 dprintk("could not detect low and high frequencies by SMI call.\n");
269 result = speedstep_get_freqs(speedstep_processor,
270 &speedstep_freqs[SPEEDSTEP_LOW].frequency,
271 &speedstep_freqs[SPEEDSTEP_HIGH].frequency,
272 &speedstep_set_state);
273
274 if (result) {
275 dprintk("could not detect two different speeds -- aborting.\n");
276 return result;
277 } else
278 dprintk("workaround worked.\n");
279 }
280
281 /* get current speed setting */
282 state = speedstep_get_state();
283 speed = speedstep_freqs[state].frequency;
284
285 dprintk("currently at %s speed setting - %i MHz\n",
286 (speed == speedstep_freqs[SPEEDSTEP_LOW].frequency) ? "low" : "high",
287 (speed / 1000));
288
289 /* cpuinfo and default policy values */
290 policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
291 policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
292 policy->cur = speed;
293
294 result = cpufreq_frequency_table_cpuinfo(policy, speedstep_freqs);
295 if (result)
296 return (result);
297
298 cpufreq_frequency_table_get_attr(speedstep_freqs, policy->cpu);
299
300 return 0;
301}
302
303static int speedstep_cpu_exit(struct cpufreq_policy *policy)
304{
305 cpufreq_frequency_table_put_attr(policy->cpu);
306 return 0;
307}
308
309static unsigned int speedstep_get(unsigned int cpu)
310{
311 if (cpu)
312 return -ENODEV;
313 return speedstep_get_processor_frequency(speedstep_processor);
314}
315
316
317static int speedstep_resume(struct cpufreq_policy *policy)
318{
319 int result = speedstep_smi_ownership();
320
321 if (result)
322 dprintk("fails in re-aquiring ownership of a SMI interface.\n");
323
324 return result;
325}
326
327static struct freq_attr* speedstep_attr[] = {
328 &cpufreq_freq_attr_scaling_available_freqs,
329 NULL,
330};
331
332static struct cpufreq_driver speedstep_driver = {
333 .name = "speedstep-smi",
334 .verify = speedstep_verify,
335 .target = speedstep_target,
336 .init = speedstep_cpu_init,
337 .exit = speedstep_cpu_exit,
338 .get = speedstep_get,
339 .resume = speedstep_resume,
340 .owner = THIS_MODULE,
341 .attr = speedstep_attr,
342};
343
344/**
345 * speedstep_init - initializes the SpeedStep CPUFreq driver
346 *
347 * Initializes the SpeedStep support. Returns -ENODEV on unsupported
348 * BIOS, -EINVAL on problems during initiatization, and zero on
349 * success.
350 */
351static int __init speedstep_init(void)
352{
353 speedstep_processor = speedstep_detect_processor();
354
355 switch (speedstep_processor) {
356 case SPEEDSTEP_PROCESSOR_PIII_T:
357 case SPEEDSTEP_PROCESSOR_PIII_C:
358 case SPEEDSTEP_PROCESSOR_PIII_C_EARLY:
359 break;
360 default:
361 speedstep_processor = 0;
362 }
363
364 if (!speedstep_processor) {
365 dprintk ("No supported Intel CPU detected.\n");
366 return -ENODEV;
367 }
368
369 dprintk("signature:0x%.8lx, command:0x%.8lx, event:0x%.8lx, perf_level:0x%.8lx.\n",
370 ist_info.signature, ist_info.command, ist_info.event, ist_info.perf_level);
371
372
373 /* Error if no IST-SMI BIOS or no PARM
374 sig= 'ISGE' aka 'Intel Speedstep Gate E' */
375 if ((ist_info.signature != 0x47534943) && (
376 (smi_port == 0) || (smi_cmd == 0)))
377 return -ENODEV;
378
379 if (smi_sig == 1)
380 smi_sig = 0x47534943;
381 else
382 smi_sig = ist_info.signature;
383
384 /* setup smi_port from MODLULE_PARM or BIOS */
385 if ((smi_port > 0xff) || (smi_port < 0)) {
386 return -EINVAL;
387 } else if (smi_port == 0) {
388 smi_port = ist_info.command & 0xff;
389 }
390
391 if ((smi_cmd > 0xff) || (smi_cmd < 0)) {
392 return -EINVAL;
393 } else if (smi_cmd == 0) {
394 smi_cmd = (ist_info.command >> 16) & 0xff;
395 }
396
397 return cpufreq_register_driver(&speedstep_driver);
398}
399
400
401/**
402 * speedstep_exit - unregisters SpeedStep support
403 *
404 * Unregisters SpeedStep support.
405 */
406static void __exit speedstep_exit(void)
407{
408 cpufreq_unregister_driver(&speedstep_driver);
409}
410
411module_param(smi_port, int, 0444);
412module_param(smi_cmd, int, 0444);
413module_param(smi_sig, uint, 0444);
414
415MODULE_PARM_DESC(smi_port, "Override the BIOS-given IST port with this value -- Intel's default setting is 0xb2");
416MODULE_PARM_DESC(smi_cmd, "Override the BIOS-given IST command with this value -- Intel's default setting is 0x82");
417MODULE_PARM_DESC(smi_sig, "Set to 1 to fake the IST signature when using the SMI interface.");
418
419MODULE_AUTHOR ("Hiroshi Miura");
420MODULE_DESCRIPTION ("Speedstep driver for IST applet SMI interface.");
421MODULE_LICENSE ("GPL");
422
423module_init(speedstep_init);
424module_exit(speedstep_exit);