| /* |
| * acpi-cpufreq.c - ACPI Processor P-States Driver ($Revision: 1.3 $) |
| * |
| * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com> |
| * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com> |
| * Copyright (C) 2002 - 2004 Dominik Brodowski <linux@brodo.de> |
| * |
| * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or (at |
| * your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, but |
| * WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License along |
| * with this program; if not, write to the Free Software Foundation, Inc., |
| * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. |
| * |
| * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| */ |
| |
| #include <linux/config.h> |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/init.h> |
| #include <linux/cpufreq.h> |
| #include <linux/proc_fs.h> |
| #include <linux/seq_file.h> |
| #include <linux/compiler.h> |
| #include <linux/sched.h> /* current */ |
| #include <asm/io.h> |
| #include <asm/delay.h> |
| #include <asm/uaccess.h> |
| |
| #include <linux/acpi.h> |
| #include <acpi/processor.h> |
| |
| #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "acpi-cpufreq", msg) |
| |
| MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski"); |
| 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 acpi_processor_performance *acpi_perf_data[NR_CPUS]; |
| |
| static struct cpufreq_driver acpi_cpufreq_driver; |
| |
| static unsigned int acpi_pstate_strict; |
| |
| static int |
| acpi_processor_write_port( |
| u16 port, |
| u8 bit_width, |
| u32 value) |
| { |
| if (bit_width <= 8) { |
| outb(value, port); |
| } else if (bit_width <= 16) { |
| outw(value, port); |
| } else if (bit_width <= 32) { |
| outl(value, port); |
| } else { |
| return -ENODEV; |
| } |
| return 0; |
| } |
| |
| static int |
| acpi_processor_read_port( |
| u16 port, |
| u8 bit_width, |
| u32 *ret) |
| { |
| *ret = 0; |
| if (bit_width <= 8) { |
| *ret = inb(port); |
| } else if (bit_width <= 16) { |
| *ret = inw(port); |
| } else if (bit_width <= 32) { |
| *ret = inl(port); |
| } else { |
| return -ENODEV; |
| } |
| return 0; |
| } |
| |
| static int |
| acpi_processor_set_performance ( |
| struct cpufreq_acpi_io *data, |
| unsigned int cpu, |
| int state) |
| { |
| u16 port = 0; |
| u8 bit_width = 0; |
| int i = 0; |
| int ret = 0; |
| u32 value = 0; |
| int retval; |
| struct acpi_processor_performance *perf; |
| |
| dprintk("acpi_processor_set_performance\n"); |
| |
| retval = 0; |
| perf = data->acpi_data; |
| if (state == perf->state) { |
| if (unlikely(data->resume)) { |
| dprintk("Called after resume, resetting to P%d\n", state); |
| data->resume = 0; |
| } else { |
| dprintk("Already at target state (P%d)\n", state); |
| return (retval); |
| } |
| } |
| |
| dprintk("Transitioning from P%d to P%d\n", perf->state, state); |
| |
| /* |
| * First we write the target state's 'control' value to the |
| * control_register. |
| */ |
| |
| port = perf->control_register.address; |
| bit_width = perf->control_register.bit_width; |
| value = (u32) perf->states[state].control; |
| |
| dprintk("Writing 0x%08x to port 0x%04x\n", value, port); |
| |
| ret = acpi_processor_write_port(port, bit_width, value); |
| if (ret) { |
| dprintk("Invalid port width 0x%04x\n", bit_width); |
| return (ret); |
| } |
| |
| /* |
| * Assume the write went through when acpi_pstate_strict is not used. |
| * As read status_register is an expensive operation and there |
| * are no specific error cases where an IO port write will fail. |
| */ |
| if (acpi_pstate_strict) { |
| /* Then we read the 'status_register' and compare the value |
| * with the target state's 'status' to make sure the |
| * transition was successful. |
| * Note that we'll poll for up to 1ms (100 cycles of 10us) |
| * before giving up. |
| */ |
| |
| port = perf->status_register.address; |
| bit_width = perf->status_register.bit_width; |
| |
| dprintk("Looking for 0x%08x from port 0x%04x\n", |
| (u32) perf->states[state].status, port); |
| |
| for (i = 0; i < 100; i++) { |
| ret = acpi_processor_read_port(port, bit_width, &value); |
| if (ret) { |
| dprintk("Invalid port width 0x%04x\n", bit_width); |
| return (ret); |
| } |
| if (value == (u32) perf->states[state].status) |
| break; |
| udelay(10); |
| } |
| } else { |
| value = (u32) perf->states[state].status; |
| } |
| |
| if (unlikely(value != (u32) perf->states[state].status)) { |
| printk(KERN_WARNING "acpi-cpufreq: Transition failed\n"); |
| retval = -ENODEV; |
| return (retval); |
| } |
| |
| dprintk("Transition successful after %d microseconds\n", i * 10); |
| |
| perf->state = state; |
| return (retval); |
| } |
| |
| |
| 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]; |
| struct acpi_processor_performance *perf; |
| struct cpufreq_freqs freqs; |
| cpumask_t online_policy_cpus; |
| cpumask_t saved_mask; |
| cpumask_t set_mask; |
| cpumask_t covered_cpus; |
| unsigned int cur_state = 0; |
| unsigned int next_state = 0; |
| unsigned int result = 0; |
| unsigned int j; |
| unsigned int tmp; |
| |
| dprintk("acpi_cpufreq_setpolicy\n"); |
| |
| result = cpufreq_frequency_table_target(policy, |
| data->freq_table, |
| target_freq, |
| relation, |
| &next_state); |
| if (unlikely(result)) |
| return (result); |
| |
| perf = data->acpi_data; |
| cur_state = perf->state; |
| freqs.old = data->freq_table[cur_state].frequency; |
| freqs.new = data->freq_table[next_state].frequency; |
| |
| #ifdef CONFIG_HOTPLUG_CPU |
| /* cpufreq holds the hotplug lock, so we are safe from here on */ |
| cpus_and(online_policy_cpus, cpu_online_map, policy->cpus); |
| #else |
| online_policy_cpus = policy->cpus; |
| #endif |
| |
| for_each_cpu_mask(j, online_policy_cpus) { |
| freqs.cpu = j; |
| cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); |
| } |
| |
| /* |
| * We need to call driver->target() on all or any CPU in |
| * policy->cpus, depending on policy->shared_type. |
| */ |
| saved_mask = current->cpus_allowed; |
| cpus_clear(covered_cpus); |
| for_each_cpu_mask(j, online_policy_cpus) { |
| /* |
| * Support for SMP systems. |
| * Make sure we are running on CPU that wants to change freq |
| */ |
| cpus_clear(set_mask); |
| if (policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) |
| cpus_or(set_mask, set_mask, online_policy_cpus); |
| else |
| cpu_set(j, set_mask); |
| |
| set_cpus_allowed(current, set_mask); |
| if (unlikely(!cpu_isset(smp_processor_id(), set_mask))) { |
| dprintk("couldn't limit to CPUs in this domain\n"); |
| result = -EAGAIN; |
| break; |
| } |
| |
| result = acpi_processor_set_performance (data, j, next_state); |
| if (result) { |
| result = -EAGAIN; |
| break; |
| } |
| |
| if (policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) |
| break; |
| |
| cpu_set(j, covered_cpus); |
| } |
| |
| for_each_cpu_mask(j, online_policy_cpus) { |
| freqs.cpu = j; |
| cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); |
| } |
| |
| if (unlikely(result)) { |
| /* |
| * We have failed halfway through the frequency change. |
| * We have sent callbacks to online_policy_cpus and |
| * acpi_processor_set_performance() has been called on |
| * coverd_cpus. Best effort undo.. |
| */ |
| |
| if (!cpus_empty(covered_cpus)) { |
| for_each_cpu_mask(j, covered_cpus) { |
| policy->cpu = j; |
| acpi_processor_set_performance (data, |
| j, |
| cur_state); |
| } |
| } |
| |
| tmp = freqs.new; |
| freqs.new = freqs.old; |
| freqs.old = tmp; |
| for_each_cpu_mask(j, online_policy_cpus) { |
| freqs.cpu = j; |
| cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); |
| cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); |
| } |
| } |
| |
| set_cpus_allowed(current, saved_mask); |
| 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]; |
| |
| dprintk("acpi_cpufreq_verify\n"); |
| |
| result = cpufreq_frequency_table_verify(policy, |
| data->freq_table); |
| |
| return (result); |
| } |
| |
| |
| static unsigned long |
| acpi_cpufreq_guess_freq ( |
| struct cpufreq_acpi_io *data, |
| unsigned int cpu) |
| { |
| struct acpi_processor_performance *perf = data->acpi_data; |
| |
| if (cpu_khz) { |
| /* search the closest match to cpu_khz */ |
| unsigned int i; |
| unsigned long freq; |
| unsigned long freqn = perf->states[0].core_frequency * 1000; |
| |
| for (i = 0; i < (perf->state_count - 1); i++) { |
| freq = freqn; |
| freqn = perf->states[i+1].core_frequency * 1000; |
| if ((2 * cpu_khz) > (freqn + freq)) { |
| perf->state = i; |
| return (freq); |
| } |
| } |
| perf->state = perf->state_count - 1; |
| return (freqn); |
| } else { |
| /* assume CPU is at P0... */ |
| perf->state = 0; |
| return perf->states[0].core_frequency * 1000; |
| } |
| } |
| |
| |
| /* |
| * acpi_cpufreq_early_init - initialize ACPI P-States library |
| * |
| * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c) |
| * in order to determine correct frequency and voltage pairings. We can |
| * do _PDC and _PSD and find out the processor dependency for the |
| * actual init that will happen later... |
| */ |
| static int acpi_cpufreq_early_init_acpi(void) |
| { |
| struct acpi_processor_performance *data; |
| unsigned int i, j; |
| |
| dprintk("acpi_cpufreq_early_init\n"); |
| |
| for_each_possible_cpu(i) { |
| data = kzalloc(sizeof(struct acpi_processor_performance), |
| GFP_KERNEL); |
| if (!data) { |
| for_each_possible_cpu(j) { |
| kfree(acpi_perf_data[j]); |
| acpi_perf_data[j] = NULL; |
| } |
| return (-ENOMEM); |
| } |
| acpi_perf_data[i] = data; |
| } |
| |
| /* Do initialization in ACPI core */ |
| acpi_processor_preregister_performance(acpi_perf_data); |
| return 0; |
| } |
| |
| 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; |
| struct cpuinfo_x86 *c = &cpu_data[policy->cpu]; |
| struct acpi_processor_performance *perf; |
| |
| dprintk("acpi_cpufreq_cpu_init\n"); |
| |
| if (!acpi_perf_data[cpu]) |
| return (-ENODEV); |
| |
| data = kzalloc(sizeof(struct cpufreq_acpi_io), GFP_KERNEL); |
| if (!data) |
| return (-ENOMEM); |
| |
| data->acpi_data = acpi_perf_data[cpu]; |
| acpi_io_data[cpu] = data; |
| |
| result = acpi_processor_register_performance(data->acpi_data, cpu); |
| |
| if (result) |
| goto err_free; |
| |
| perf = data->acpi_data; |
| policy->shared_type = perf->shared_type; |
| /* |
| * Will let policy->cpus know about dependency only when software |
| * coordination is required. |
| */ |
| if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL || |
| policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) |
| policy->cpus = perf->shared_cpu_map; |
| |
| if (cpu_has(c, X86_FEATURE_CONSTANT_TSC)) { |
| acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS; |
| } |
| |
| /* capability check */ |
| if (perf->state_count <= 1) { |
| dprintk("No P-States\n"); |
| result = -ENODEV; |
| goto err_unreg; |
| } |
| |
| if ((perf->control_register.space_id != ACPI_ADR_SPACE_SYSTEM_IO) || |
| (perf->status_register.space_id != ACPI_ADR_SPACE_SYSTEM_IO)) { |
| dprintk("Unsupported address space [%d, %d]\n", |
| (u32) (perf->control_register.space_id), |
| (u32) (perf->status_register.space_id)); |
| result = -ENODEV; |
| goto err_unreg; |
| } |
| |
| /* alloc freq_table */ |
| data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) * (perf->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<perf->state_count; i++) { |
| if ((perf->states[i].transition_latency * 1000) > policy->cpuinfo.transition_latency) |
| policy->cpuinfo.transition_latency = perf->states[i].transition_latency * 1000; |
| } |
| policy->governor = CPUFREQ_DEFAULT_GOVERNOR; |
| |
| /* The current speed is unknown and not detectable by ACPI... */ |
| policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu); |
| |
| /* table init */ |
| for (i=0; i<=perf->state_count; i++) |
| { |
| data->freq_table[i].index = i; |
| if (i<perf->state_count) |
| data->freq_table[i].frequency = perf->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 < perf->state_count; i++) |
| dprintk(" %cP%d: %d MHz, %d mW, %d uS\n", |
| (i == perf->state?'*':' '), i, |
| (u32) perf->states[i].core_frequency, |
| (u32) perf->states[i].power, |
| (u32) perf->states[i].transition_latency); |
| |
| 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(perf, 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]; |
| |
| |
| dprintk("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 int |
| acpi_cpufreq_resume ( |
| struct cpufreq_policy *policy) |
| { |
| struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu]; |
| |
| |
| dprintk("acpi_cpufreq_resume\n"); |
| |
| data->resume = 1; |
| |
| 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, |
| .init = acpi_cpufreq_cpu_init, |
| .exit = acpi_cpufreq_cpu_exit, |
| .resume = acpi_cpufreq_resume, |
| .name = "acpi-cpufreq", |
| .owner = THIS_MODULE, |
| .attr = acpi_cpufreq_attr, |
| .flags = CPUFREQ_STICKY, |
| }; |
| |
| |
| static int __init |
| acpi_cpufreq_init (void) |
| { |
| int result = 0; |
| |
| dprintk("acpi_cpufreq_init\n"); |
| |
| result = acpi_cpufreq_early_init_acpi(); |
| |
| if (!result) |
| result = cpufreq_register_driver(&acpi_cpufreq_driver); |
| |
| return (result); |
| } |
| |
| |
| static void __exit |
| acpi_cpufreq_exit (void) |
| { |
| unsigned int i; |
| dprintk("acpi_cpufreq_exit\n"); |
| |
| cpufreq_unregister_driver(&acpi_cpufreq_driver); |
| |
| for_each_possible_cpu(i) { |
| kfree(acpi_perf_data[i]); |
| acpi_perf_data[i] = NULL; |
| } |
| return; |
| } |
| |
| module_param(acpi_pstate_strict, uint, 0644); |
| MODULE_PARM_DESC(acpi_pstate_strict, "value 0 or non-zero. non-zero -> strict ACPI checks are performed during frequency changes."); |
| |
| late_initcall(acpi_cpufreq_init); |
| module_exit(acpi_cpufreq_exit); |
| |
| MODULE_ALIAS("acpi"); |