| /* |
| * This file provides the ACPI based P-state support. This |
| * module works with generic cpufreq infrastructure. Most of |
| * the code is based on i386 version |
| * (arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c) |
| * |
| * Copyright (C) 2005 Intel Corp |
| * Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/slab.h> |
| #include <linux/module.h> |
| #include <linux/init.h> |
| #include <linux/cpufreq.h> |
| #include <linux/proc_fs.h> |
| #include <linux/seq_file.h> |
| #include <asm/io.h> |
| #include <asm/uaccess.h> |
| #include <asm/pal.h> |
| |
| #include <linux/acpi.h> |
| #include <acpi/processor.h> |
| |
| MODULE_AUTHOR("Venkatesh Pallipadi"); |
| MODULE_DESCRIPTION("ACPI Processor P-States Driver"); |
| MODULE_LICENSE("GPL"); |
| |
| |
| struct cpufreq_acpi_io { |
| struct acpi_processor_performance acpi_data; |
| struct cpufreq_frequency_table *freq_table; |
| unsigned int resume; |
| }; |
| |
| static struct cpufreq_acpi_io *acpi_io_data[NR_CPUS]; |
| |
| static struct cpufreq_driver acpi_cpufreq_driver; |
| |
| |
| static int |
| processor_set_pstate ( |
| u32 value) |
| { |
| s64 retval; |
| |
| pr_debug("processor_set_pstate\n"); |
| |
| retval = ia64_pal_set_pstate((u64)value); |
| |
| if (retval) { |
| pr_debug("Failed to set freq to 0x%x, with error 0x%lx\n", |
| value, retval); |
| return -ENODEV; |
| } |
| return (int)retval; |
| } |
| |
| |
| static int |
| processor_get_pstate ( |
| u32 *value) |
| { |
| u64 pstate_index = 0; |
| s64 retval; |
| |
| pr_debug("processor_get_pstate\n"); |
| |
| retval = ia64_pal_get_pstate(&pstate_index, |
| PAL_GET_PSTATE_TYPE_INSTANT); |
| *value = (u32) pstate_index; |
| |
| if (retval) |
| pr_debug("Failed to get current freq with " |
| "error 0x%lx, idx 0x%x\n", retval, *value); |
| |
| return (int)retval; |
| } |
| |
| |
| /* To be used only after data->acpi_data is initialized */ |
| static unsigned |
| extract_clock ( |
| struct cpufreq_acpi_io *data, |
| unsigned value, |
| unsigned int cpu) |
| { |
| unsigned long i; |
| |
| pr_debug("extract_clock\n"); |
| |
| for (i = 0; i < data->acpi_data.state_count; i++) { |
| if (value == data->acpi_data.states[i].status) |
| return data->acpi_data.states[i].core_frequency; |
| } |
| return data->acpi_data.states[i-1].core_frequency; |
| } |
| |
| |
| static unsigned int |
| processor_get_freq ( |
| struct cpufreq_acpi_io *data, |
| unsigned int cpu) |
| { |
| int ret = 0; |
| u32 value = 0; |
| cpumask_t saved_mask; |
| unsigned long clock_freq; |
| |
| pr_debug("processor_get_freq\n"); |
| |
| saved_mask = current->cpus_allowed; |
| set_cpus_allowed_ptr(current, cpumask_of(cpu)); |
| if (smp_processor_id() != cpu) |
| goto migrate_end; |
| |
| /* processor_get_pstate gets the instantaneous frequency */ |
| ret = processor_get_pstate(&value); |
| |
| if (ret) { |
| set_cpus_allowed_ptr(current, &saved_mask); |
| printk(KERN_WARNING "get performance failed with error %d\n", |
| ret); |
| ret = 0; |
| goto migrate_end; |
| } |
| clock_freq = extract_clock(data, value, cpu); |
| ret = (clock_freq*1000); |
| |
| migrate_end: |
| set_cpus_allowed_ptr(current, &saved_mask); |
| return ret; |
| } |
| |
| |
| static int |
| processor_set_freq ( |
| struct cpufreq_acpi_io *data, |
| unsigned int cpu, |
| int state) |
| { |
| int ret = 0; |
| u32 value = 0; |
| struct cpufreq_freqs cpufreq_freqs; |
| cpumask_t saved_mask; |
| int retval; |
| |
| pr_debug("processor_set_freq\n"); |
| |
| saved_mask = current->cpus_allowed; |
| set_cpus_allowed_ptr(current, cpumask_of(cpu)); |
| if (smp_processor_id() != cpu) { |
| retval = -EAGAIN; |
| goto migrate_end; |
| } |
| |
| if (state == data->acpi_data.state) { |
| if (unlikely(data->resume)) { |
| pr_debug("Called after resume, resetting to P%d\n", state); |
| data->resume = 0; |
| } else { |
| pr_debug("Already at target state (P%d)\n", state); |
| retval = 0; |
| goto migrate_end; |
| } |
| } |
| |
| pr_debug("Transitioning from P%d to P%d\n", |
| data->acpi_data.state, state); |
| |
| /* cpufreq frequency struct */ |
| cpufreq_freqs.cpu = cpu; |
| cpufreq_freqs.old = data->freq_table[data->acpi_data.state].frequency; |
| cpufreq_freqs.new = data->freq_table[state].frequency; |
| |
| /* notify cpufreq */ |
| cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_PRECHANGE); |
| |
| /* |
| * First we write the target state's 'control' value to the |
| * control_register. |
| */ |
| |
| value = (u32) data->acpi_data.states[state].control; |
| |
| pr_debug("Transitioning to state: 0x%08x\n", value); |
| |
| ret = processor_set_pstate(value); |
| if (ret) { |
| unsigned int tmp = cpufreq_freqs.new; |
| cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE); |
| cpufreq_freqs.new = cpufreq_freqs.old; |
| cpufreq_freqs.old = tmp; |
| cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_PRECHANGE); |
| cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE); |
| printk(KERN_WARNING "Transition failed with error %d\n", ret); |
| retval = -ENODEV; |
| goto migrate_end; |
| } |
| |
| cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE); |
| |
| data->acpi_data.state = state; |
| |
| retval = 0; |
| |
| migrate_end: |
| set_cpus_allowed_ptr(current, &saved_mask); |
| return (retval); |
| } |
| |
| |
| static unsigned int |
| acpi_cpufreq_get ( |
| unsigned int cpu) |
| { |
| struct cpufreq_acpi_io *data = acpi_io_data[cpu]; |
| |
| pr_debug("acpi_cpufreq_get\n"); |
| |
| return processor_get_freq(data, cpu); |
| } |
| |
| |
| static int |
| acpi_cpufreq_target ( |
| struct cpufreq_policy *policy, |
| unsigned int target_freq, |
| unsigned int relation) |
| { |
| struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu]; |
| unsigned int next_state = 0; |
| unsigned int result = 0; |
| |
| pr_debug("acpi_cpufreq_setpolicy\n"); |
| |
| result = cpufreq_frequency_table_target(policy, |
| data->freq_table, target_freq, relation, &next_state); |
| if (result) |
| return (result); |
| |
| result = processor_set_freq(data, policy->cpu, next_state); |
| |
| return (result); |
| } |
| |
| |
| static int |
| acpi_cpufreq_verify ( |
| struct cpufreq_policy *policy) |
| { |
| unsigned int result = 0; |
| struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu]; |
| |
| pr_debug("acpi_cpufreq_verify\n"); |
| |
| result = cpufreq_frequency_table_verify(policy, |
| data->freq_table); |
| |
| return (result); |
| } |
| |
| |
| static int |
| acpi_cpufreq_cpu_init ( |
| struct cpufreq_policy *policy) |
| { |
| unsigned int i; |
| unsigned int cpu = policy->cpu; |
| struct cpufreq_acpi_io *data; |
| unsigned int result = 0; |
| |
| pr_debug("acpi_cpufreq_cpu_init\n"); |
| |
| data = kzalloc(sizeof(struct cpufreq_acpi_io), GFP_KERNEL); |
| if (!data) |
| return (-ENOMEM); |
| |
| acpi_io_data[cpu] = data; |
| |
| result = acpi_processor_register_performance(&data->acpi_data, cpu); |
| |
| if (result) |
| goto err_free; |
| |
| /* capability check */ |
| if (data->acpi_data.state_count <= 1) { |
| pr_debug("No P-States\n"); |
| result = -ENODEV; |
| goto err_unreg; |
| } |
| |
| if ((data->acpi_data.control_register.space_id != |
| ACPI_ADR_SPACE_FIXED_HARDWARE) || |
| (data->acpi_data.status_register.space_id != |
| ACPI_ADR_SPACE_FIXED_HARDWARE)) { |
| pr_debug("Unsupported address space [%d, %d]\n", |
| (u32) (data->acpi_data.control_register.space_id), |
| (u32) (data->acpi_data.status_register.space_id)); |
| result = -ENODEV; |
| goto err_unreg; |
| } |
| |
| /* alloc freq_table */ |
| data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) * |
| (data->acpi_data.state_count + 1), |
| GFP_KERNEL); |
| if (!data->freq_table) { |
| result = -ENOMEM; |
| goto err_unreg; |
| } |
| |
| /* detect transition latency */ |
| policy->cpuinfo.transition_latency = 0; |
| for (i=0; i<data->acpi_data.state_count; i++) { |
| if ((data->acpi_data.states[i].transition_latency * 1000) > |
| policy->cpuinfo.transition_latency) { |
| policy->cpuinfo.transition_latency = |
| data->acpi_data.states[i].transition_latency * 1000; |
| } |
| } |
| policy->cur = processor_get_freq(data, policy->cpu); |
| |
| /* table init */ |
| for (i = 0; i <= data->acpi_data.state_count; i++) |
| { |
| data->freq_table[i].index = i; |
| if (i < data->acpi_data.state_count) { |
| data->freq_table[i].frequency = |
| data->acpi_data.states[i].core_frequency * 1000; |
| } else { |
| data->freq_table[i].frequency = CPUFREQ_TABLE_END; |
| } |
| } |
| |
| result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table); |
| if (result) { |
| goto err_freqfree; |
| } |
| |
| /* notify BIOS that we exist */ |
| acpi_processor_notify_smm(THIS_MODULE); |
| |
| printk(KERN_INFO "acpi-cpufreq: CPU%u - ACPI performance management " |
| "activated.\n", cpu); |
| |
| for (i = 0; i < data->acpi_data.state_count; i++) |
| pr_debug(" %cP%d: %d MHz, %d mW, %d uS, %d uS, 0x%x 0x%x\n", |
| (i == data->acpi_data.state?'*':' '), i, |
| (u32) data->acpi_data.states[i].core_frequency, |
| (u32) data->acpi_data.states[i].power, |
| (u32) data->acpi_data.states[i].transition_latency, |
| (u32) data->acpi_data.states[i].bus_master_latency, |
| (u32) data->acpi_data.states[i].status, |
| (u32) data->acpi_data.states[i].control); |
| |
| cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu); |
| |
| /* the first call to ->target() should result in us actually |
| * writing something to the appropriate registers. */ |
| data->resume = 1; |
| |
| return (result); |
| |
| err_freqfree: |
| kfree(data->freq_table); |
| err_unreg: |
| acpi_processor_unregister_performance(&data->acpi_data, cpu); |
| err_free: |
| kfree(data); |
| acpi_io_data[cpu] = NULL; |
| |
| return (result); |
| } |
| |
| |
| static int |
| acpi_cpufreq_cpu_exit ( |
| struct cpufreq_policy *policy) |
| { |
| struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu]; |
| |
| pr_debug("acpi_cpufreq_cpu_exit\n"); |
| |
| if (data) { |
| cpufreq_frequency_table_put_attr(policy->cpu); |
| acpi_io_data[policy->cpu] = NULL; |
| acpi_processor_unregister_performance(&data->acpi_data, |
| policy->cpu); |
| kfree(data); |
| } |
| |
| return (0); |
| } |
| |
| |
| static struct freq_attr* acpi_cpufreq_attr[] = { |
| &cpufreq_freq_attr_scaling_available_freqs, |
| NULL, |
| }; |
| |
| |
| static struct cpufreq_driver acpi_cpufreq_driver = { |
| .verify = acpi_cpufreq_verify, |
| .target = acpi_cpufreq_target, |
| .get = acpi_cpufreq_get, |
| .init = acpi_cpufreq_cpu_init, |
| .exit = acpi_cpufreq_cpu_exit, |
| .name = "acpi-cpufreq", |
| .owner = THIS_MODULE, |
| .attr = acpi_cpufreq_attr, |
| }; |
| |
| |
| static int __init |
| acpi_cpufreq_init (void) |
| { |
| pr_debug("acpi_cpufreq_init\n"); |
| |
| return cpufreq_register_driver(&acpi_cpufreq_driver); |
| } |
| |
| |
| static void __exit |
| acpi_cpufreq_exit (void) |
| { |
| pr_debug("acpi_cpufreq_exit\n"); |
| |
| cpufreq_unregister_driver(&acpi_cpufreq_driver); |
| return; |
| } |
| |
| |
| late_initcall(acpi_cpufreq_init); |
| module_exit(acpi_cpufreq_exit); |
| |