linux/drivers/acpi/processor_perflib.c

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/*
* processor_perflib.c - ACPI Processor P-States Library ($Revision: 71 $)
*
* Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
* Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
* Copyright (C) 2004 Dominik Brodowski <linux@brodo.de>
* Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
* - Added processor hotplug support
*
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* 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/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/cpufreq.h>
#ifdef CONFIG_X86_ACPI_CPUFREQ_PROC_INTF
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <asm/uaccess.h>
#endif
#include <acpi/acpi_bus.h>
#include <acpi/processor.h>
#define ACPI_PROCESSOR_COMPONENT 0x01000000
#define ACPI_PROCESSOR_CLASS "processor"
#define ACPI_PROCESSOR_DRIVER_NAME "ACPI Processor Driver"
#define ACPI_PROCESSOR_FILE_PERFORMANCE "performance"
#define _COMPONENT ACPI_PROCESSOR_COMPONENT
ACPI_MODULE_NAME("acpi_processor")
static DECLARE_MUTEX(performance_sem);
/*
* _PPC support is implemented as a CPUfreq policy notifier:
* This means each time a CPUfreq driver registered also with
* the ACPI core is asked to change the speed policy, the maximum
* value is adjusted so that it is within the platform limit.
*
* Also, when a new platform limit value is detected, the CPUfreq
* policy is adjusted accordingly.
*/
#define PPC_REGISTERED 1
#define PPC_IN_USE 2
static int acpi_processor_ppc_status = 0;
static int acpi_processor_ppc_notifier(struct notifier_block *nb,
unsigned long event, void *data)
{
struct cpufreq_policy *policy = data;
struct acpi_processor *pr;
unsigned int ppc = 0;
down(&performance_sem);
if (event != CPUFREQ_INCOMPATIBLE)
goto out;
pr = processors[policy->cpu];
if (!pr || !pr->performance)
goto out;
ppc = (unsigned int)pr->performance_platform_limit;
if (!ppc)
goto out;
if (ppc > pr->performance->state_count)
goto out;
cpufreq_verify_within_limits(policy, 0,
pr->performance->states[ppc].
core_frequency * 1000);
out:
up(&performance_sem);
return 0;
}
static struct notifier_block acpi_ppc_notifier_block = {
.notifier_call = acpi_processor_ppc_notifier,
};
static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
{
acpi_status status = 0;
unsigned long ppc = 0;
ACPI_FUNCTION_TRACE("acpi_processor_get_platform_limit");
if (!pr)
return_VALUE(-EINVAL);
/*
* _PPC indicates the maximum state currently supported by the platform
* (e.g. 0 = states 0..n; 1 = states 1..n; etc.
*/
status = acpi_evaluate_integer(pr->handle, "_PPC", NULL, &ppc);
if (status != AE_NOT_FOUND)
acpi_processor_ppc_status |= PPC_IN_USE;
if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PPC\n"));
return_VALUE(-ENODEV);
}
pr->performance_platform_limit = (int)ppc;
return_VALUE(0);
}
int acpi_processor_ppc_has_changed(struct acpi_processor *pr)
{
int ret = acpi_processor_get_platform_limit(pr);
if (ret < 0)
return (ret);
else
return cpufreq_update_policy(pr->id);
}
void acpi_processor_ppc_init(void)
{
if (!cpufreq_register_notifier
(&acpi_ppc_notifier_block, CPUFREQ_POLICY_NOTIFIER))
acpi_processor_ppc_status |= PPC_REGISTERED;
else
printk(KERN_DEBUG
"Warning: Processor Platform Limit not supported.\n");
}
void acpi_processor_ppc_exit(void)
{
if (acpi_processor_ppc_status & PPC_REGISTERED)
cpufreq_unregister_notifier(&acpi_ppc_notifier_block,
CPUFREQ_POLICY_NOTIFIER);
acpi_processor_ppc_status &= ~PPC_REGISTERED;
}
static int acpi_processor_get_performance_control(struct acpi_processor *pr)
{
int result = 0;
acpi_status status = 0;
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
union acpi_object *pct = NULL;
union acpi_object obj = { 0 };
ACPI_FUNCTION_TRACE("acpi_processor_get_performance_control");
status = acpi_evaluate_object(pr->handle, "_PCT", NULL, &buffer);
if (ACPI_FAILURE(status)) {
ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PCT\n"));
return_VALUE(-ENODEV);
}
pct = (union acpi_object *)buffer.pointer;
if (!pct || (pct->type != ACPI_TYPE_PACKAGE)
|| (pct->package.count != 2)) {
ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _PCT data\n"));
result = -EFAULT;
goto end;
}
/*
* control_register
*/
obj = pct->package.elements[0];
if ((obj.type != ACPI_TYPE_BUFFER)
|| (obj.buffer.length < sizeof(struct acpi_pct_register))
|| (obj.buffer.pointer == NULL)) {
ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
"Invalid _PCT data (control_register)\n"));
result = -EFAULT;
goto end;
}
memcpy(&pr->performance->control_register, obj.buffer.pointer,
sizeof(struct acpi_pct_register));
/*
* status_register
*/
obj = pct->package.elements[1];
if ((obj.type != ACPI_TYPE_BUFFER)
|| (obj.buffer.length < sizeof(struct acpi_pct_register))
|| (obj.buffer.pointer == NULL)) {
ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
"Invalid _PCT data (status_register)\n"));
result = -EFAULT;
goto end;
}
memcpy(&pr->performance->status_register, obj.buffer.pointer,
sizeof(struct acpi_pct_register));
end:
acpi_os_free(buffer.pointer);
return_VALUE(result);
}
static int acpi_processor_get_performance_states(struct acpi_processor *pr)
{
int result = 0;
acpi_status status = AE_OK;
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
struct acpi_buffer format = { sizeof("NNNNNN"), "NNNNNN" };
struct acpi_buffer state = { 0, NULL };
union acpi_object *pss = NULL;
int i;
ACPI_FUNCTION_TRACE("acpi_processor_get_performance_states");
status = acpi_evaluate_object(pr->handle, "_PSS", NULL, &buffer);
if (ACPI_FAILURE(status)) {
ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PSS\n"));
return_VALUE(-ENODEV);
}
pss = (union acpi_object *)buffer.pointer;
if (!pss || (pss->type != ACPI_TYPE_PACKAGE)) {
ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _PSS data\n"));
result = -EFAULT;
goto end;
}
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d performance states\n",
pss->package.count));
pr->performance->state_count = pss->package.count;
pr->performance->states =
kmalloc(sizeof(struct acpi_processor_px) * pss->package.count,
GFP_KERNEL);
if (!pr->performance->states) {
result = -ENOMEM;
goto end;
}
for (i = 0; i < pr->performance->state_count; i++) {
struct acpi_processor_px *px = &(pr->performance->states[i]);
state.length = sizeof(struct acpi_processor_px);
state.pointer = px;
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Extracting state %d\n", i));
status = acpi_extract_package(&(pss->package.elements[i]),
&format, &state);
if (ACPI_FAILURE(status)) {
ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
"Invalid _PSS data\n"));
result = -EFAULT;
kfree(pr->performance->states);
goto end;
}
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"State [%d]: core_frequency[%d] power[%d] transition_latency[%d] bus_master_latency[%d] control[0x%x] status[0x%x]\n",
i,
(u32) px->core_frequency,
(u32) px->power,
(u32) px->transition_latency,
(u32) px->bus_master_latency,
(u32) px->control, (u32) px->status));
if (!px->core_frequency) {
ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
"Invalid _PSS data: freq is zero\n"));
result = -EFAULT;
kfree(pr->performance->states);
goto end;
}
}
end:
acpi_os_free(buffer.pointer);
return_VALUE(result);
}
static int acpi_processor_get_performance_info(struct acpi_processor *pr)
{
int result = 0;
acpi_status status = AE_OK;
acpi_handle handle = NULL;
ACPI_FUNCTION_TRACE("acpi_processor_get_performance_info");
if (!pr || !pr->performance || !pr->handle)
return_VALUE(-EINVAL);
acpi_processor_set_pdc(pr, pr->performance->pdc);
status = acpi_get_handle(pr->handle, "_PCT", &handle);
if (ACPI_FAILURE(status)) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"ACPI-based processor performance control unavailable\n"));
return_VALUE(-ENODEV);
}
result = acpi_processor_get_performance_control(pr);
if (result)
return_VALUE(result);
result = acpi_processor_get_performance_states(pr);
if (result)
return_VALUE(result);
result = acpi_processor_get_platform_limit(pr);
if (result)
return_VALUE(result);
return_VALUE(0);
}
int acpi_processor_notify_smm(struct module *calling_module)
{
acpi_status status;
static int is_done = 0;
ACPI_FUNCTION_TRACE("acpi_processor_notify_smm");
if (!(acpi_processor_ppc_status & PPC_REGISTERED))
return_VALUE(-EBUSY);
if (!try_module_get(calling_module))
return_VALUE(-EINVAL);
/* is_done is set to negative if an error occured,
* and to postitive if _no_ error occured, but SMM
* was already notified. This avoids double notification
* which might lead to unexpected results...
*/
if (is_done > 0) {
module_put(calling_module);
return_VALUE(0);
} else if (is_done < 0) {
module_put(calling_module);
return_VALUE(is_done);
}
is_done = -EIO;
/* Can't write pstate_cnt to smi_cmd if either value is zero */
if ((!acpi_fadt.smi_cmd) || (!acpi_fadt.pstate_cnt)) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No SMI port or pstate_cnt\n"));
module_put(calling_module);
return_VALUE(0);
}
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Writing pstate_cnt [0x%x] to smi_cmd [0x%x]\n",
acpi_fadt.pstate_cnt, acpi_fadt.smi_cmd));
/* FADT v1 doesn't support pstate_cnt, many BIOS vendors use
* it anyway, so we need to support it... */
if (acpi_fadt_is_v1) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Using v1.0 FADT reserved value for pstate_cnt\n"));
}
status = acpi_os_write_port(acpi_fadt.smi_cmd,
(u32) acpi_fadt.pstate_cnt, 8);
if (ACPI_FAILURE(status)) {
ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
"Failed to write pstate_cnt [0x%x] to "
"smi_cmd [0x%x]\n", acpi_fadt.pstate_cnt,
acpi_fadt.smi_cmd));
module_put(calling_module);
return_VALUE(status);
}
/* Success. If there's no _PPC, we need to fear nothing, so
* we can allow the cpufreq driver to be rmmod'ed. */
is_done = 1;
if (!(acpi_processor_ppc_status & PPC_IN_USE))
module_put(calling_module);
return_VALUE(0);
}
EXPORT_SYMBOL(acpi_processor_notify_smm);
#ifdef CONFIG_X86_ACPI_CPUFREQ_PROC_INTF
/* /proc/acpi/processor/../performance interface (DEPRECATED) */
static int acpi_processor_perf_open_fs(struct inode *inode, struct file *file);
static struct file_operations acpi_processor_perf_fops = {
.open = acpi_processor_perf_open_fs,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static int acpi_processor_perf_seq_show(struct seq_file *seq, void *offset)
{
struct acpi_processor *pr = (struct acpi_processor *)seq->private;
int i;
ACPI_FUNCTION_TRACE("acpi_processor_perf_seq_show");
if (!pr)
goto end;
if (!pr->performance) {
seq_puts(seq, "<not supported>\n");
goto end;
}
seq_printf(seq, "state count: %d\n"
"active state: P%d\n",
pr->performance->state_count, pr->performance->state);
seq_puts(seq, "states:\n");
for (i = 0; i < pr->performance->state_count; i++)
seq_printf(seq,
" %cP%d: %d MHz, %d mW, %d uS\n",
(i == pr->performance->state ? '*' : ' '), i,
(u32) pr->performance->states[i].core_frequency,
(u32) pr->performance->states[i].power,
(u32) pr->performance->states[i].transition_latency);
end:
return_VALUE(0);
}
static int acpi_processor_perf_open_fs(struct inode *inode, struct file *file)
{
return single_open(file, acpi_processor_perf_seq_show,
PDE(inode)->data);
}
static ssize_t
acpi_processor_write_performance(struct file *file,
const char __user * buffer,
size_t count, loff_t * data)
{
int result = 0;
struct seq_file *m = (struct seq_file *)file->private_data;
struct acpi_processor *pr = (struct acpi_processor *)m->private;
struct acpi_processor_performance *perf;
char state_string[12] = { '\0' };
unsigned int new_state = 0;
struct cpufreq_policy policy;
ACPI_FUNCTION_TRACE("acpi_processor_write_performance");
if (!pr || (count > sizeof(state_string) - 1))
return_VALUE(-EINVAL);
perf = pr->performance;
if (!perf)
return_VALUE(-EINVAL);
if (copy_from_user(state_string, buffer, count))
return_VALUE(-EFAULT);
state_string[count] = '\0';
new_state = simple_strtoul(state_string, NULL, 0);
if (new_state >= perf->state_count)
return_VALUE(-EINVAL);
cpufreq_get_policy(&policy, pr->id);
policy.cpu = pr->id;
policy.min = perf->states[new_state].core_frequency * 1000;
policy.max = perf->states[new_state].core_frequency * 1000;
result = cpufreq_set_policy(&policy);
if (result)
return_VALUE(result);
return_VALUE(count);
}
static void acpi_cpufreq_add_file(struct acpi_processor *pr)
{
struct proc_dir_entry *entry = NULL;
struct acpi_device *device = NULL;
ACPI_FUNCTION_TRACE("acpi_cpufreq_addfile");
if (acpi_bus_get_device(pr->handle, &device))
return_VOID;
/* add file 'performance' [R/W] */
entry = create_proc_entry(ACPI_PROCESSOR_FILE_PERFORMANCE,
S_IFREG | S_IRUGO | S_IWUSR,
acpi_device_dir(device));
if (!entry)
ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
"Unable to create '%s' fs entry\n",
ACPI_PROCESSOR_FILE_PERFORMANCE));
else {
entry->proc_fops = &acpi_processor_perf_fops;
entry->proc_fops->write = acpi_processor_write_performance;
entry->data = acpi_driver_data(device);
entry->owner = THIS_MODULE;
}
return_VOID;
}
static void acpi_cpufreq_remove_file(struct acpi_processor *pr)
{
struct acpi_device *device = NULL;
ACPI_FUNCTION_TRACE("acpi_cpufreq_addfile");
if (acpi_bus_get_device(pr->handle, &device))
return_VOID;
/* remove file 'performance' */
remove_proc_entry(ACPI_PROCESSOR_FILE_PERFORMANCE,
acpi_device_dir(device));
return_VOID;
}
#else
static void acpi_cpufreq_add_file(struct acpi_processor *pr)
{
return;
}
static void acpi_cpufreq_remove_file(struct acpi_processor *pr)
{
return;
}
#endif /* CONFIG_X86_ACPI_CPUFREQ_PROC_INTF */
int
acpi_processor_register_performance(struct acpi_processor_performance
*performance, unsigned int cpu)
{
struct acpi_processor *pr;
ACPI_FUNCTION_TRACE("acpi_processor_register_performance");
if (!(acpi_processor_ppc_status & PPC_REGISTERED))
return_VALUE(-EINVAL);
down(&performance_sem);
pr = processors[cpu];
if (!pr) {
up(&performance_sem);
return_VALUE(-ENODEV);
}
if (pr->performance) {
up(&performance_sem);
return_VALUE(-EBUSY);
}
pr->performance = performance;
if (acpi_processor_get_performance_info(pr)) {
pr->performance = NULL;
up(&performance_sem);
return_VALUE(-EIO);
}
acpi_cpufreq_add_file(pr);
up(&performance_sem);
return_VALUE(0);
}
EXPORT_SYMBOL(acpi_processor_register_performance);
void
acpi_processor_unregister_performance(struct acpi_processor_performance
*performance, unsigned int cpu)
{
struct acpi_processor *pr;
ACPI_FUNCTION_TRACE("acpi_processor_unregister_performance");
down(&performance_sem);
pr = processors[cpu];
if (!pr) {
up(&performance_sem);
return_VOID;
}
kfree(pr->performance->states);
pr->performance = NULL;
acpi_cpufreq_remove_file(pr);
up(&performance_sem);
return_VOID;
}
EXPORT_SYMBOL(acpi_processor_unregister_performance);