1 // SPDX-License-Identifier: GPL-2.0-only
3  * This file provides the ACPI based P-state support. This
6  * (arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c)
28 MODULE_DESCRIPTION("ACPI Processor P-States Driver");
59 		return -ENODEV;  in processor_set_pstate()
86 /* To be used only after data->acpi_data is initialized */
96 	for (i = 0; i < data->acpi_data.state_count; i++) {  in extract_clock()
97 		if (value == data->acpi_data.states[i].status)  in extract_clock()
98 			return data->acpi_data.states[i].core_frequency;  in extract_clock()
100 	return data->acpi_data.states[i-1].core_frequency;  in extract_clock()
109 	unsigned int		cpu = req->cpu;  in processor_get_freq()
116 		return -EAGAIN;  in processor_get_freq()
133 	unsigned int		cpu = req->cpu;  in processor_set_freq()
135 	int			ret, state = req->state;  in processor_set_freq()
140 		return -EAGAIN;  in processor_set_freq()
142 	if (state == data->acpi_data.state) {  in processor_set_freq()
143 		if (unlikely(data->resume)) {  in processor_set_freq()
144 			pr_debug("Called after resume, resetting to P%d\n", state);  in processor_set_freq()
145 			data->resume = 0;  in processor_set_freq()
147 			pr_debug("Already at target state (P%d)\n", state);  in processor_set_freq()
152 	pr_debug("Transitioning from P%d to P%d\n",  in processor_set_freq()
153 		data->acpi_data.state, state);  in processor_set_freq()
159 	value = (u32) data->acpi_data.states[state].control;  in processor_set_freq()
166 		return -ENODEV;  in processor_set_freq()
169 	data->acpi_data.state = state;  in processor_set_freq()
195 	req.cpu = policy->cpu;  in acpi_cpufreq_target()
206 	unsigned int		cpu = policy->cpu;  in acpi_cpufreq_cpu_init()
215 		return (-ENOMEM);  in acpi_cpufreq_cpu_init()
219 	result = acpi_processor_register_performance(&data->acpi_data, cpu);  in acpi_cpufreq_cpu_init()
225 	if (data->acpi_data.state_count <= 1) {  in acpi_cpufreq_cpu_init()
226 		pr_debug("No P-States\n");  in acpi_cpufreq_cpu_init()
227 		result = -ENODEV;  in acpi_cpufreq_cpu_init()
231 	if ((data->acpi_data.control_register.space_id !=  in acpi_cpufreq_cpu_init()
233 	    (data->acpi_data.status_register.space_id !=  in acpi_cpufreq_cpu_init()
236 			(u32) (data->acpi_data.control_register.space_id),  in acpi_cpufreq_cpu_init()
237 			(u32) (data->acpi_data.status_register.space_id));  in acpi_cpufreq_cpu_init()
238 		result = -ENODEV;  in acpi_cpufreq_cpu_init()
243 	freq_table = kcalloc(data->acpi_data.state_count + 1,  in acpi_cpufreq_cpu_init()
247 		result = -ENOMEM;  in acpi_cpufreq_cpu_init()
252 	policy->cpuinfo.transition_latency = 0;  in acpi_cpufreq_cpu_init()
253 	for (i=0; i<data->acpi_data.state_count; i++) {  in acpi_cpufreq_cpu_init()
254 		if ((data->acpi_data.states[i].transition_latency * 1000) >  in acpi_cpufreq_cpu_init()
255 		    policy->cpuinfo.transition_latency) {  in acpi_cpufreq_cpu_init()
256 			policy->cpuinfo.transition_latency =  in acpi_cpufreq_cpu_init()
257 			    data->acpi_data.states[i].transition_latency * 1000;  in acpi_cpufreq_cpu_init()
262 	for (i = 0; i <= data->acpi_data.state_count; i++)  in acpi_cpufreq_cpu_init()
264 		if (i < data->acpi_data.state_count) {  in acpi_cpufreq_cpu_init()
266 			      data->acpi_data.states[i].core_frequency * 1000;  in acpi_cpufreq_cpu_init()
272 	policy->freq_table = freq_table;  in acpi_cpufreq_cpu_init()
277 	pr_info("CPU%u - ACPI performance management activated\n", cpu);  in acpi_cpufreq_cpu_init()
279 	for (i = 0; i < data->acpi_data.state_count; i++)  in acpi_cpufreq_cpu_init()
281 			(i == data->acpi_data.state?'*':' '), i,  in acpi_cpufreq_cpu_init()
282 			(u32) data->acpi_data.states[i].core_frequency,  in acpi_cpufreq_cpu_init()
283 			(u32) data->acpi_data.states[i].power,  in acpi_cpufreq_cpu_init()
284 			(u32) data->acpi_data.states[i].transition_latency,  in acpi_cpufreq_cpu_init()
285 			(u32) data->acpi_data.states[i].bus_master_latency,  in acpi_cpufreq_cpu_init()
286 			(u32) data->acpi_data.states[i].status,  in acpi_cpufreq_cpu_init()
287 			(u32) data->acpi_data.states[i].control);  in acpi_cpufreq_cpu_init()
289 	/* the first call to ->target() should result in us actually  in acpi_cpufreq_cpu_init()
291 	data->resume = 1;  in acpi_cpufreq_cpu_init()
309 	struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];  in acpi_cpufreq_cpu_exit()
314 		acpi_io_data[policy->cpu] = NULL;  in acpi_cpufreq_cpu_exit()
315 		acpi_processor_unregister_performance(policy->cpu);  in acpi_cpufreq_cpu_exit()
316 		kfree(policy->freq_table);  in acpi_cpufreq_cpu_exit()
330 	.name		= "acpi-cpufreq",