Contributors: 25
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Shaohua Li |
1849 |
88.26% |
1 |
3.23% |
| Chen Gong |
45 |
2.15% |
2 |
6.45% |
| Venkatesh Pallipadi |
32 |
1.53% |
1 |
3.23% |
| Len Brown |
23 |
1.10% |
3 |
9.68% |
| Rusty Russell |
23 |
1.10% |
1 |
3.23% |
| Manuel Schölling |
17 |
0.81% |
1 |
3.23% |
| Tony Camuso |
15 |
0.72% |
1 |
3.23% |
| Jiang Liu |
14 |
0.67% |
1 |
3.23% |
| Juergen Gross |
13 |
0.62% |
1 |
3.23% |
| Thomas Gleixner |
10 |
0.48% |
4 |
12.90% |
| Lenny Szubowicz |
10 |
0.48% |
1 |
3.23% |
| Stuart Hayes |
9 |
0.43% |
1 |
3.23% |
| Andrew Morton |
6 |
0.29% |
1 |
3.23% |
| Josh |
4 |
0.19% |
1 |
3.23% |
| Sudeep Holla |
4 |
0.19% |
1 |
3.23% |
| H. Peter Anvin |
3 |
0.14% |
1 |
3.23% |
| Tejun Heo |
3 |
0.14% |
1 |
3.23% |
| Pu Wen |
3 |
0.14% |
1 |
3.23% |
| Tony W Wang-oc |
3 |
0.14% |
1 |
3.23% |
| Ingo Molnar |
3 |
0.14% |
1 |
3.23% |
| Chumbalkar Nagananda |
2 |
0.10% |
1 |
3.23% |
| Lv Zheng |
1 |
0.05% |
1 |
3.23% |
| Peter Zijlstra |
1 |
0.05% |
1 |
3.23% |
| Bartosz Golaszewski |
1 |
0.05% |
1 |
3.23% |
| Dan Carpenter |
1 |
0.05% |
1 |
3.23% |
| Total |
2095 |
|
31 |
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* acpi_pad.c ACPI Processor Aggregator Driver
*
* Copyright (c) 2009, Intel Corporation.
*/
#include <linux/kernel.h>
#include <linux/cpumask.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/kthread.h>
#include <uapi/linux/sched/types.h>
#include <linux/freezer.h>
#include <linux/cpu.h>
#include <linux/tick.h>
#include <linux/slab.h>
#include <linux/acpi.h>
#include <asm/mwait.h>
#include <xen/xen.h>
#define ACPI_PROCESSOR_AGGREGATOR_CLASS "acpi_pad"
#define ACPI_PROCESSOR_AGGREGATOR_DEVICE_NAME "Processor Aggregator"
#define ACPI_PROCESSOR_AGGREGATOR_NOTIFY 0x80
static DEFINE_MUTEX(isolated_cpus_lock);
static DEFINE_MUTEX(round_robin_lock);
static unsigned long power_saving_mwait_eax;
static unsigned char tsc_detected_unstable;
static unsigned char tsc_marked_unstable;
static void power_saving_mwait_init(void)
{
unsigned int eax, ebx, ecx, edx;
unsigned int highest_cstate = 0;
unsigned int highest_subcstate = 0;
int i;
if (!boot_cpu_has(X86_FEATURE_MWAIT))
return;
if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF)
return;
cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &edx);
if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) ||
!(ecx & CPUID5_ECX_INTERRUPT_BREAK))
return;
edx >>= MWAIT_SUBSTATE_SIZE;
for (i = 0; i < 7 && edx; i++, edx >>= MWAIT_SUBSTATE_SIZE) {
if (edx & MWAIT_SUBSTATE_MASK) {
highest_cstate = i;
highest_subcstate = edx & MWAIT_SUBSTATE_MASK;
}
}
power_saving_mwait_eax = (highest_cstate << MWAIT_SUBSTATE_SIZE) |
(highest_subcstate - 1);
#if defined(CONFIG_X86)
switch (boot_cpu_data.x86_vendor) {
case X86_VENDOR_HYGON:
case X86_VENDOR_AMD:
case X86_VENDOR_INTEL:
case X86_VENDOR_ZHAOXIN:
/*
* AMD Fam10h TSC will tick in all
* C/P/S0/S1 states when this bit is set.
*/
if (!boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
tsc_detected_unstable = 1;
break;
default:
/* TSC could halt in idle */
tsc_detected_unstable = 1;
}
#endif
}
static unsigned long cpu_weight[NR_CPUS];
static int tsk_in_cpu[NR_CPUS] = {[0 ... NR_CPUS-1] = -1};
static DECLARE_BITMAP(pad_busy_cpus_bits, NR_CPUS);
static void round_robin_cpu(unsigned int tsk_index)
{
struct cpumask *pad_busy_cpus = to_cpumask(pad_busy_cpus_bits);
cpumask_var_t tmp;
int cpu;
unsigned long min_weight = -1;
unsigned long uninitialized_var(preferred_cpu);
if (!alloc_cpumask_var(&tmp, GFP_KERNEL))
return;
mutex_lock(&round_robin_lock);
cpumask_clear(tmp);
for_each_cpu(cpu, pad_busy_cpus)
cpumask_or(tmp, tmp, topology_sibling_cpumask(cpu));
cpumask_andnot(tmp, cpu_online_mask, tmp);
/* avoid HT sibilings if possible */
if (cpumask_empty(tmp))
cpumask_andnot(tmp, cpu_online_mask, pad_busy_cpus);
if (cpumask_empty(tmp)) {
mutex_unlock(&round_robin_lock);
free_cpumask_var(tmp);
return;
}
for_each_cpu(cpu, tmp) {
if (cpu_weight[cpu] < min_weight) {
min_weight = cpu_weight[cpu];
preferred_cpu = cpu;
}
}
if (tsk_in_cpu[tsk_index] != -1)
cpumask_clear_cpu(tsk_in_cpu[tsk_index], pad_busy_cpus);
tsk_in_cpu[tsk_index] = preferred_cpu;
cpumask_set_cpu(preferred_cpu, pad_busy_cpus);
cpu_weight[preferred_cpu]++;
mutex_unlock(&round_robin_lock);
set_cpus_allowed_ptr(current, cpumask_of(preferred_cpu));
free_cpumask_var(tmp);
}
static void exit_round_robin(unsigned int tsk_index)
{
struct cpumask *pad_busy_cpus = to_cpumask(pad_busy_cpus_bits);
cpumask_clear_cpu(tsk_in_cpu[tsk_index], pad_busy_cpus);
tsk_in_cpu[tsk_index] = -1;
}
static unsigned int idle_pct = 5; /* percentage */
static unsigned int round_robin_time = 1; /* second */
static int power_saving_thread(void *data)
{
struct sched_param param = {.sched_priority = 1};
int do_sleep;
unsigned int tsk_index = (unsigned long)data;
u64 last_jiffies = 0;
sched_setscheduler(current, SCHED_RR, ¶m);
while (!kthread_should_stop()) {
unsigned long expire_time;
/* round robin to cpus */
expire_time = last_jiffies + round_robin_time * HZ;
if (time_before(expire_time, jiffies)) {
last_jiffies = jiffies;
round_robin_cpu(tsk_index);
}
do_sleep = 0;
expire_time = jiffies + HZ * (100 - idle_pct) / 100;
while (!need_resched()) {
if (tsc_detected_unstable && !tsc_marked_unstable) {
/* TSC could halt in idle, so notify users */
mark_tsc_unstable("TSC halts in idle");
tsc_marked_unstable = 1;
}
local_irq_disable();
tick_broadcast_enable();
tick_broadcast_enter();
stop_critical_timings();
mwait_idle_with_hints(power_saving_mwait_eax, 1);
start_critical_timings();
tick_broadcast_exit();
local_irq_enable();
if (time_before(expire_time, jiffies)) {
do_sleep = 1;
break;
}
}
/*
* current sched_rt has threshold for rt task running time.
* When a rt task uses 95% CPU time, the rt thread will be
* scheduled out for 5% CPU time to not starve other tasks. But
* the mechanism only works when all CPUs have RT task running,
* as if one CPU hasn't RT task, RT task from other CPUs will
* borrow CPU time from this CPU and cause RT task use > 95%
* CPU time. To make 'avoid starvation' work, takes a nap here.
*/
if (unlikely(do_sleep))
schedule_timeout_killable(HZ * idle_pct / 100);
/* If an external event has set the need_resched flag, then
* we need to deal with it, or this loop will continue to
* spin without calling __mwait().
*/
if (unlikely(need_resched()))
schedule();
}
exit_round_robin(tsk_index);
return 0;
}
static struct task_struct *ps_tsks[NR_CPUS];
static unsigned int ps_tsk_num;
static int create_power_saving_task(void)
{
int rc;
ps_tsks[ps_tsk_num] = kthread_run(power_saving_thread,
(void *)(unsigned long)ps_tsk_num,
"acpi_pad/%d", ps_tsk_num);
if (IS_ERR(ps_tsks[ps_tsk_num])) {
rc = PTR_ERR(ps_tsks[ps_tsk_num]);
ps_tsks[ps_tsk_num] = NULL;
} else {
rc = 0;
ps_tsk_num++;
}
return rc;
}
static void destroy_power_saving_task(void)
{
if (ps_tsk_num > 0) {
ps_tsk_num--;
kthread_stop(ps_tsks[ps_tsk_num]);
ps_tsks[ps_tsk_num] = NULL;
}
}
static void set_power_saving_task_num(unsigned int num)
{
if (num > ps_tsk_num) {
while (ps_tsk_num < num) {
if (create_power_saving_task())
return;
}
} else if (num < ps_tsk_num) {
while (ps_tsk_num > num)
destroy_power_saving_task();
}
}
static void acpi_pad_idle_cpus(unsigned int num_cpus)
{
get_online_cpus();
num_cpus = min_t(unsigned int, num_cpus, num_online_cpus());
set_power_saving_task_num(num_cpus);
put_online_cpus();
}
static uint32_t acpi_pad_idle_cpus_num(void)
{
return ps_tsk_num;
}
static ssize_t acpi_pad_rrtime_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t count)
{
unsigned long num;
if (kstrtoul(buf, 0, &num))
return -EINVAL;
if (num < 1 || num >= 100)
return -EINVAL;
mutex_lock(&isolated_cpus_lock);
round_robin_time = num;
mutex_unlock(&isolated_cpus_lock);
return count;
}
static ssize_t acpi_pad_rrtime_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
return scnprintf(buf, PAGE_SIZE, "%d\n", round_robin_time);
}
static DEVICE_ATTR(rrtime, S_IRUGO|S_IWUSR,
acpi_pad_rrtime_show,
acpi_pad_rrtime_store);
static ssize_t acpi_pad_idlepct_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t count)
{
unsigned long num;
if (kstrtoul(buf, 0, &num))
return -EINVAL;
if (num < 1 || num >= 100)
return -EINVAL;
mutex_lock(&isolated_cpus_lock);
idle_pct = num;
mutex_unlock(&isolated_cpus_lock);
return count;
}
static ssize_t acpi_pad_idlepct_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
return scnprintf(buf, PAGE_SIZE, "%d\n", idle_pct);
}
static DEVICE_ATTR(idlepct, S_IRUGO|S_IWUSR,
acpi_pad_idlepct_show,
acpi_pad_idlepct_store);
static ssize_t acpi_pad_idlecpus_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t count)
{
unsigned long num;
if (kstrtoul(buf, 0, &num))
return -EINVAL;
mutex_lock(&isolated_cpus_lock);
acpi_pad_idle_cpus(num);
mutex_unlock(&isolated_cpus_lock);
return count;
}
static ssize_t acpi_pad_idlecpus_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
return cpumap_print_to_pagebuf(false, buf,
to_cpumask(pad_busy_cpus_bits));
}
static DEVICE_ATTR(idlecpus, S_IRUGO|S_IWUSR,
acpi_pad_idlecpus_show,
acpi_pad_idlecpus_store);
static int acpi_pad_add_sysfs(struct acpi_device *device)
{
int result;
result = device_create_file(&device->dev, &dev_attr_idlecpus);
if (result)
return -ENODEV;
result = device_create_file(&device->dev, &dev_attr_idlepct);
if (result) {
device_remove_file(&device->dev, &dev_attr_idlecpus);
return -ENODEV;
}
result = device_create_file(&device->dev, &dev_attr_rrtime);
if (result) {
device_remove_file(&device->dev, &dev_attr_idlecpus);
device_remove_file(&device->dev, &dev_attr_idlepct);
return -ENODEV;
}
return 0;
}
static void acpi_pad_remove_sysfs(struct acpi_device *device)
{
device_remove_file(&device->dev, &dev_attr_idlecpus);
device_remove_file(&device->dev, &dev_attr_idlepct);
device_remove_file(&device->dev, &dev_attr_rrtime);
}
/*
* Query firmware how many CPUs should be idle
* return -1 on failure
*/
static int acpi_pad_pur(acpi_handle handle)
{
struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
union acpi_object *package;
int num = -1;
if (ACPI_FAILURE(acpi_evaluate_object(handle, "_PUR", NULL, &buffer)))
return num;
if (!buffer.length || !buffer.pointer)
return num;
package = buffer.pointer;
if (package->type == ACPI_TYPE_PACKAGE &&
package->package.count == 2 &&
package->package.elements[0].integer.value == 1) /* rev 1 */
num = package->package.elements[1].integer.value;
kfree(buffer.pointer);
return num;
}
static void acpi_pad_handle_notify(acpi_handle handle)
{
int num_cpus;
uint32_t idle_cpus;
struct acpi_buffer param = {
.length = 4,
.pointer = (void *)&idle_cpus,
};
mutex_lock(&isolated_cpus_lock);
num_cpus = acpi_pad_pur(handle);
if (num_cpus < 0) {
mutex_unlock(&isolated_cpus_lock);
return;
}
acpi_pad_idle_cpus(num_cpus);
idle_cpus = acpi_pad_idle_cpus_num();
acpi_evaluate_ost(handle, ACPI_PROCESSOR_AGGREGATOR_NOTIFY, 0, ¶m);
mutex_unlock(&isolated_cpus_lock);
}
static void acpi_pad_notify(acpi_handle handle, u32 event,
void *data)
{
struct acpi_device *device = data;
switch (event) {
case ACPI_PROCESSOR_AGGREGATOR_NOTIFY:
acpi_pad_handle_notify(handle);
acpi_bus_generate_netlink_event(device->pnp.device_class,
dev_name(&device->dev), event, 0);
break;
default:
pr_warn("Unsupported event [0x%x]\n", event);
break;
}
}
static int acpi_pad_add(struct acpi_device *device)
{
acpi_status status;
strcpy(acpi_device_name(device), ACPI_PROCESSOR_AGGREGATOR_DEVICE_NAME);
strcpy(acpi_device_class(device), ACPI_PROCESSOR_AGGREGATOR_CLASS);
if (acpi_pad_add_sysfs(device))
return -ENODEV;
status = acpi_install_notify_handler(device->handle,
ACPI_DEVICE_NOTIFY, acpi_pad_notify, device);
if (ACPI_FAILURE(status)) {
acpi_pad_remove_sysfs(device);
return -ENODEV;
}
return 0;
}
static int acpi_pad_remove(struct acpi_device *device)
{
mutex_lock(&isolated_cpus_lock);
acpi_pad_idle_cpus(0);
mutex_unlock(&isolated_cpus_lock);
acpi_remove_notify_handler(device->handle,
ACPI_DEVICE_NOTIFY, acpi_pad_notify);
acpi_pad_remove_sysfs(device);
return 0;
}
static const struct acpi_device_id pad_device_ids[] = {
{"ACPI000C", 0},
{"", 0},
};
MODULE_DEVICE_TABLE(acpi, pad_device_ids);
static struct acpi_driver acpi_pad_driver = {
.name = "processor_aggregator",
.class = ACPI_PROCESSOR_AGGREGATOR_CLASS,
.ids = pad_device_ids,
.ops = {
.add = acpi_pad_add,
.remove = acpi_pad_remove,
},
};
static int __init acpi_pad_init(void)
{
/* Xen ACPI PAD is used when running as Xen Dom0. */
if (xen_initial_domain())
return -ENODEV;
power_saving_mwait_init();
if (power_saving_mwait_eax == 0)
return -EINVAL;
return acpi_bus_register_driver(&acpi_pad_driver);
}
static void __exit acpi_pad_exit(void)
{
acpi_bus_unregister_driver(&acpi_pad_driver);
}
module_init(acpi_pad_init);
module_exit(acpi_pad_exit);
MODULE_AUTHOR("Shaohua Li<shaohua.li@intel.com>");
MODULE_DESCRIPTION("ACPI Processor Aggregator Driver");
MODULE_LICENSE("GPL");