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)
7 * Copyright (C) 2005 Intel Corp
8 * Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
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>
19 #include <asm/uaccess.h>
22 #include <linux/acpi.h>
23 #include <acpi/processor.h>
25 MODULE_AUTHOR("Venkatesh Pallipadi");
26 MODULE_DESCRIPTION("ACPI Processor P-States Driver");
27 MODULE_LICENSE("GPL");
30 struct cpufreq_acpi_io {
31 struct acpi_processor_performance acpi_data;
32 struct cpufreq_frequency_table *freq_table;
36 static struct cpufreq_acpi_io *acpi_io_data[NR_CPUS];
38 static struct cpufreq_driver acpi_cpufreq_driver;
42 processor_set_pstate (
47 pr_debug("processor_set_pstate\n");
49 retval = ia64_pal_set_pstate((u64)value);
52 pr_debug("Failed to set freq to 0x%x, with error 0x%lx\n",
61 processor_get_pstate (
67 pr_debug("processor_get_pstate\n");
69 retval = ia64_pal_get_pstate(&pstate_index,
70 PAL_GET_PSTATE_TYPE_INSTANT);
71 *value = (u32) pstate_index;
74 pr_debug("Failed to get current freq with "
75 "error 0x%lx, idx 0x%x\n", retval, *value);
81 /* To be used only after data->acpi_data is initialized */
84 struct cpufreq_acpi_io *data,
90 pr_debug("extract_clock\n");
92 for (i = 0; i < data->acpi_data.state_count; i++) {
93 if (value == data->acpi_data.states[i].status)
94 return data->acpi_data.states[i].core_frequency;
96 return data->acpi_data.states[i-1].core_frequency;
102 struct cpufreq_acpi_io *data,
107 cpumask_t saved_mask;
108 unsigned long clock_freq;
110 pr_debug("processor_get_freq\n");
112 saved_mask = current->cpus_allowed;
113 set_cpus_allowed_ptr(current, cpumask_of(cpu));
114 if (smp_processor_id() != cpu)
117 /* processor_get_pstate gets the instantaneous frequency */
118 ret = processor_get_pstate(&value);
121 set_cpus_allowed_ptr(current, &saved_mask);
122 printk(KERN_WARNING "get performance failed with error %d\n",
127 clock_freq = extract_clock(data, value, cpu);
128 ret = (clock_freq*1000);
131 set_cpus_allowed_ptr(current, &saved_mask);
138 struct cpufreq_acpi_io *data,
139 struct cpufreq_policy *policy,
144 struct cpufreq_freqs cpufreq_freqs;
145 cpumask_t saved_mask;
148 pr_debug("processor_set_freq\n");
150 saved_mask = current->cpus_allowed;
151 set_cpus_allowed_ptr(current, cpumask_of(policy->cpu));
152 if (smp_processor_id() != policy->cpu) {
157 if (state == data->acpi_data.state) {
158 if (unlikely(data->resume)) {
159 pr_debug("Called after resume, resetting to P%d\n", state);
162 pr_debug("Already at target state (P%d)\n", state);
168 pr_debug("Transitioning from P%d to P%d\n",
169 data->acpi_data.state, state);
171 /* cpufreq frequency struct */
172 cpufreq_freqs.old = data->freq_table[data->acpi_data.state].frequency;
173 cpufreq_freqs.new = data->freq_table[state].frequency;
176 cpufreq_notify_transition(policy, &cpufreq_freqs, CPUFREQ_PRECHANGE);
179 * First we write the target state's 'control' value to the
183 value = (u32) data->acpi_data.states[state].control;
185 pr_debug("Transitioning to state: 0x%08x\n", value);
187 ret = processor_set_pstate(value);
189 unsigned int tmp = cpufreq_freqs.new;
190 cpufreq_notify_transition(policy, &cpufreq_freqs,
192 cpufreq_freqs.new = cpufreq_freqs.old;
193 cpufreq_freqs.old = tmp;
194 cpufreq_notify_transition(policy, &cpufreq_freqs,
196 cpufreq_notify_transition(policy, &cpufreq_freqs,
198 printk(KERN_WARNING "Transition failed with error %d\n", ret);
203 cpufreq_notify_transition(policy, &cpufreq_freqs, CPUFREQ_POSTCHANGE);
205 data->acpi_data.state = state;
210 set_cpus_allowed_ptr(current, &saved_mask);
219 struct cpufreq_acpi_io *data = acpi_io_data[cpu];
221 pr_debug("acpi_cpufreq_get\n");
223 return processor_get_freq(data, cpu);
228 acpi_cpufreq_target (
229 struct cpufreq_policy *policy,
230 unsigned int target_freq,
231 unsigned int relation)
233 struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
234 unsigned int next_state = 0;
235 unsigned int result = 0;
237 pr_debug("acpi_cpufreq_setpolicy\n");
239 result = cpufreq_frequency_table_target(policy,
240 data->freq_table, target_freq, relation, &next_state);
244 result = processor_set_freq(data, policy, next_state);
251 acpi_cpufreq_cpu_init (
252 struct cpufreq_policy *policy)
255 unsigned int cpu = policy->cpu;
256 struct cpufreq_acpi_io *data;
257 unsigned int result = 0;
259 pr_debug("acpi_cpufreq_cpu_init\n");
261 data = kzalloc(sizeof(*data), GFP_KERNEL);
265 acpi_io_data[cpu] = data;
267 result = acpi_processor_register_performance(&data->acpi_data, cpu);
272 /* capability check */
273 if (data->acpi_data.state_count <= 1) {
274 pr_debug("No P-States\n");
279 if ((data->acpi_data.control_register.space_id !=
280 ACPI_ADR_SPACE_FIXED_HARDWARE) ||
281 (data->acpi_data.status_register.space_id !=
282 ACPI_ADR_SPACE_FIXED_HARDWARE)) {
283 pr_debug("Unsupported address space [%d, %d]\n",
284 (u32) (data->acpi_data.control_register.space_id),
285 (u32) (data->acpi_data.status_register.space_id));
290 /* alloc freq_table */
291 data->freq_table = kmalloc(sizeof(*data->freq_table) *
292 (data->acpi_data.state_count + 1),
294 if (!data->freq_table) {
299 /* detect transition latency */
300 policy->cpuinfo.transition_latency = 0;
301 for (i=0; i<data->acpi_data.state_count; i++) {
302 if ((data->acpi_data.states[i].transition_latency * 1000) >
303 policy->cpuinfo.transition_latency) {
304 policy->cpuinfo.transition_latency =
305 data->acpi_data.states[i].transition_latency * 1000;
310 for (i = 0; i <= data->acpi_data.state_count; i++)
312 data->freq_table[i].driver_data = i;
313 if (i < data->acpi_data.state_count) {
314 data->freq_table[i].frequency =
315 data->acpi_data.states[i].core_frequency * 1000;
317 data->freq_table[i].frequency = CPUFREQ_TABLE_END;
321 result = cpufreq_table_validate_and_show(policy, data->freq_table);
326 /* notify BIOS that we exist */
327 acpi_processor_notify_smm(THIS_MODULE);
329 printk(KERN_INFO "acpi-cpufreq: CPU%u - ACPI performance management "
330 "activated.\n", cpu);
332 for (i = 0; i < data->acpi_data.state_count; i++)
333 pr_debug(" %cP%d: %d MHz, %d mW, %d uS, %d uS, 0x%x 0x%x\n",
334 (i == data->acpi_data.state?'*':' '), i,
335 (u32) data->acpi_data.states[i].core_frequency,
336 (u32) data->acpi_data.states[i].power,
337 (u32) data->acpi_data.states[i].transition_latency,
338 (u32) data->acpi_data.states[i].bus_master_latency,
339 (u32) data->acpi_data.states[i].status,
340 (u32) data->acpi_data.states[i].control);
342 /* the first call to ->target() should result in us actually
343 * writing something to the appropriate registers. */
349 kfree(data->freq_table);
351 acpi_processor_unregister_performance(&data->acpi_data, cpu);
354 acpi_io_data[cpu] = NULL;
361 acpi_cpufreq_cpu_exit (
362 struct cpufreq_policy *policy)
364 struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
366 pr_debug("acpi_cpufreq_cpu_exit\n");
369 cpufreq_frequency_table_put_attr(policy->cpu);
370 acpi_io_data[policy->cpu] = NULL;
371 acpi_processor_unregister_performance(&data->acpi_data,
380 static struct cpufreq_driver acpi_cpufreq_driver = {
381 .verify = cpufreq_generic_frequency_table_verify,
382 .target = acpi_cpufreq_target,
383 .get = acpi_cpufreq_get,
384 .init = acpi_cpufreq_cpu_init,
385 .exit = acpi_cpufreq_cpu_exit,
386 .name = "acpi-cpufreq",
387 .attr = cpufreq_generic_attr,
392 acpi_cpufreq_init (void)
394 pr_debug("acpi_cpufreq_init\n");
396 return cpufreq_register_driver(&acpi_cpufreq_driver);
401 acpi_cpufreq_exit (void)
403 pr_debug("acpi_cpufreq_exit\n");
405 cpufreq_unregister_driver(&acpi_cpufreq_driver);
410 late_initcall(acpi_cpufreq_init);
411 module_exit(acpi_cpufreq_exit);