2 * arch/ia64/kernel/cpufreq/acpi-cpufreq.c
3 * This file provides the ACPI based P-state support. This
4 * module works with generic cpufreq infrastructure. Most of
5 * the code is based on i386 version
6 * (arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c)
8 * Copyright (C) 2005 Intel Corp
9 * Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
12 #include <linux/kernel.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>
19 #include <asm/uaccess.h>
22 #include <linux/acpi.h>
23 #include <acpi/processor.h>
25 #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "acpi-cpufreq", msg)
27 MODULE_AUTHOR("Venkatesh Pallipadi");
28 MODULE_DESCRIPTION("ACPI Processor P-States Driver");
29 MODULE_LICENSE("GPL");
32 struct cpufreq_acpi_io {
33 struct acpi_processor_performance acpi_data;
34 struct cpufreq_frequency_table *freq_table;
38 static struct cpufreq_acpi_io *acpi_io_data[NR_CPUS];
40 static struct cpufreq_driver acpi_cpufreq_driver;
44 processor_set_pstate (
49 dprintk("processor_set_pstate\n");
51 retval = ia64_pal_set_pstate((u64)value);
54 dprintk("Failed to set freq to 0x%x, with error 0x%x\n",
63 processor_get_pstate (
69 dprintk("processor_get_pstate\n");
71 retval = ia64_pal_get_pstate(&pstate_index,
72 PAL_GET_PSTATE_TYPE_INSTANT);
73 *value = (u32) pstate_index;
76 dprintk("Failed to get current freq with "
77 "error 0x%x, idx 0x%x\n", retval, *value);
83 /* To be used only after data->acpi_data is initialized */
86 struct cpufreq_acpi_io *data,
92 dprintk("extract_clock\n");
94 for (i = 0; i < data->acpi_data.state_count; i++) {
95 if (value == data->acpi_data.states[i].status)
96 return data->acpi_data.states[i].core_frequency;
98 return data->acpi_data.states[i-1].core_frequency;
104 struct cpufreq_acpi_io *data,
109 cpumask_t saved_mask;
110 unsigned long clock_freq;
112 dprintk("processor_get_freq\n");
114 saved_mask = current->cpus_allowed;
115 set_cpus_allowed(current, cpumask_of_cpu(cpu));
116 if (smp_processor_id() != cpu) {
121 /* processor_get_pstate gets the instantaneous frequency */
122 ret = processor_get_pstate(&value);
125 set_cpus_allowed(current, saved_mask);
126 printk(KERN_WARNING "get performance failed with error %d\n",
131 clock_freq = extract_clock(data, value, cpu);
132 ret = (clock_freq*1000);
135 set_cpus_allowed(current, saved_mask);
142 struct cpufreq_acpi_io *data,
148 struct cpufreq_freqs cpufreq_freqs;
149 cpumask_t saved_mask;
152 dprintk("processor_set_freq\n");
154 saved_mask = current->cpus_allowed;
155 set_cpus_allowed(current, cpumask_of_cpu(cpu));
156 if (smp_processor_id() != cpu) {
161 if (state == data->acpi_data.state) {
162 if (unlikely(data->resume)) {
163 dprintk("Called after resume, resetting to P%d\n", state);
166 dprintk("Already at target state (P%d)\n", state);
172 dprintk("Transitioning from P%d to P%d\n",
173 data->acpi_data.state, state);
175 /* cpufreq frequency struct */
176 cpufreq_freqs.cpu = cpu;
177 cpufreq_freqs.old = data->freq_table[data->acpi_data.state].frequency;
178 cpufreq_freqs.new = data->freq_table[state].frequency;
181 cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_PRECHANGE);
184 * First we write the target state's 'control' value to the
188 value = (u32) data->acpi_data.states[state].control;
190 dprintk("Transitioning to state: 0x%08x\n", value);
192 ret = processor_set_pstate(value);
194 unsigned int tmp = cpufreq_freqs.new;
195 cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE);
196 cpufreq_freqs.new = cpufreq_freqs.old;
197 cpufreq_freqs.old = tmp;
198 cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_PRECHANGE);
199 cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE);
200 printk(KERN_WARNING "Transition failed with error %d\n", ret);
205 cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE);
207 data->acpi_data.state = state;
212 set_cpus_allowed(current, saved_mask);
221 struct cpufreq_acpi_io *data = acpi_io_data[cpu];
223 dprintk("acpi_cpufreq_get\n");
225 return processor_get_freq(data, cpu);
230 acpi_cpufreq_target (
231 struct cpufreq_policy *policy,
232 unsigned int target_freq,
233 unsigned int relation)
235 struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
236 unsigned int next_state = 0;
237 unsigned int result = 0;
239 dprintk("acpi_cpufreq_setpolicy\n");
241 result = cpufreq_frequency_table_target(policy,
242 data->freq_table, target_freq, relation, &next_state);
246 result = processor_set_freq(data, policy->cpu, next_state);
253 acpi_cpufreq_verify (
254 struct cpufreq_policy *policy)
256 unsigned int result = 0;
257 struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
259 dprintk("acpi_cpufreq_verify\n");
261 result = cpufreq_frequency_table_verify(policy,
269 acpi_cpufreq_cpu_init (
270 struct cpufreq_policy *policy)
273 unsigned int cpu = policy->cpu;
274 struct cpufreq_acpi_io *data;
275 unsigned int result = 0;
277 dprintk("acpi_cpufreq_cpu_init\n");
279 data = kmalloc(sizeof(struct cpufreq_acpi_io), GFP_KERNEL);
283 memset(data, 0, sizeof(struct cpufreq_acpi_io));
285 acpi_io_data[cpu] = data;
287 result = acpi_processor_register_performance(&data->acpi_data, cpu);
292 /* capability check */
293 if (data->acpi_data.state_count <= 1) {
294 dprintk("No P-States\n");
299 if ((data->acpi_data.control_register.space_id !=
300 ACPI_ADR_SPACE_FIXED_HARDWARE) ||
301 (data->acpi_data.status_register.space_id !=
302 ACPI_ADR_SPACE_FIXED_HARDWARE)) {
303 dprintk("Unsupported address space [%d, %d]\n",
304 (u32) (data->acpi_data.control_register.space_id),
305 (u32) (data->acpi_data.status_register.space_id));
310 /* alloc freq_table */
311 data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) *
312 (data->acpi_data.state_count + 1),
314 if (!data->freq_table) {
319 /* detect transition latency */
320 policy->cpuinfo.transition_latency = 0;
321 for (i=0; i<data->acpi_data.state_count; i++) {
322 if ((data->acpi_data.states[i].transition_latency * 1000) >
323 policy->cpuinfo.transition_latency) {
324 policy->cpuinfo.transition_latency =
325 data->acpi_data.states[i].transition_latency * 1000;
328 policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
330 policy->cur = processor_get_freq(data, policy->cpu);
333 for (i = 0; i <= data->acpi_data.state_count; i++)
335 data->freq_table[i].index = i;
336 if (i < data->acpi_data.state_count) {
337 data->freq_table[i].frequency =
338 data->acpi_data.states[i].core_frequency * 1000;
340 data->freq_table[i].frequency = CPUFREQ_TABLE_END;
344 result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
349 /* notify BIOS that we exist */
350 acpi_processor_notify_smm(THIS_MODULE);
352 printk(KERN_INFO "acpi-cpufreq: CPU%u - ACPI performance management "
353 "activated.\n", cpu);
355 for (i = 0; i < data->acpi_data.state_count; i++)
356 dprintk(" %cP%d: %d MHz, %d mW, %d uS, %d uS, 0x%x 0x%x\n",
357 (i == data->acpi_data.state?'*':' '), i,
358 (u32) data->acpi_data.states[i].core_frequency,
359 (u32) data->acpi_data.states[i].power,
360 (u32) data->acpi_data.states[i].transition_latency,
361 (u32) data->acpi_data.states[i].bus_master_latency,
362 (u32) data->acpi_data.states[i].status,
363 (u32) data->acpi_data.states[i].control);
365 cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
367 /* the first call to ->target() should result in us actually
368 * writing something to the appropriate registers. */
374 kfree(data->freq_table);
376 acpi_processor_unregister_performance(&data->acpi_data, cpu);
379 acpi_io_data[cpu] = NULL;
386 acpi_cpufreq_cpu_exit (
387 struct cpufreq_policy *policy)
389 struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
391 dprintk("acpi_cpufreq_cpu_exit\n");
394 cpufreq_frequency_table_put_attr(policy->cpu);
395 acpi_io_data[policy->cpu] = NULL;
396 acpi_processor_unregister_performance(&data->acpi_data,
405 static struct freq_attr* acpi_cpufreq_attr[] = {
406 &cpufreq_freq_attr_scaling_available_freqs,
411 static struct cpufreq_driver acpi_cpufreq_driver = {
412 .verify = acpi_cpufreq_verify,
413 .target = acpi_cpufreq_target,
414 .get = acpi_cpufreq_get,
415 .init = acpi_cpufreq_cpu_init,
416 .exit = acpi_cpufreq_cpu_exit,
417 .name = "acpi-cpufreq",
418 .owner = THIS_MODULE,
419 .attr = acpi_cpufreq_attr,
424 acpi_cpufreq_init (void)
426 dprintk("acpi_cpufreq_init\n");
428 return cpufreq_register_driver(&acpi_cpufreq_driver);
433 acpi_cpufreq_exit (void)
435 dprintk("acpi_cpufreq_exit\n");
437 cpufreq_unregister_driver(&acpi_cpufreq_driver);
442 late_initcall(acpi_cpufreq_init);
443 module_exit(acpi_cpufreq_exit);