mirror of
git://nv-tegra.nvidia.com/linux-nv-oot.git
synced 2025-12-22 09:11:26 +03:00
947f489dac
Adding debugfs support to force cpus into idle states. Building as module instead of driver. Generic to support any standard cpuidle implementation. Bug 3583597 Change-Id: I5dd9e8635b844f465bc4c9da7e1d45ee17dd669f Signed-off-by: Ishan Shah <ishah@nvidia.com> Reviewed-on: https://git-master.nvidia.com/r/c/linux-nv-oot/+/2814926 Reviewed-by: Laxman Dewangan <ldewangan@nvidia.com> GVS: Gerrit_Virtual_Submit <buildbot_gerritrpt@nvidia.com>
117 lines
2.6 KiB
C
117 lines
2.6 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* Copyright (c) 2023, NVIDIA CORPORATION & AFFILIATES. All Rights Reserved.
|
|
*
|
|
* Module to force cpuidle states through debugfs files.
|
|
*
|
|
*/
|
|
#include <linux/module.h>
|
|
#include <linux/irq.h>
|
|
#include <linux/irqdesc.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/debugfs.h>
|
|
#include <linux/cpu.h>
|
|
#include <linux/cpuidle.h>
|
|
|
|
#define US_TO_NS(x) (1000 * x)
|
|
|
|
static struct cpuidle_driver *drv;
|
|
|
|
static bool is_timer_irq(struct irq_desc *desc)
|
|
{
|
|
return desc && desc->action && (desc->action->flags & IRQF_TIMER);
|
|
}
|
|
|
|
static void suspend_all_device_irqs(void)
|
|
{
|
|
struct irq_data *data;
|
|
struct irq_desc *desc;
|
|
int irq;
|
|
|
|
for (irq = 0, data = irq_get_irq_data(irq); irq < nr_irqs;
|
|
irq++, data = irq_get_irq_data(irq)) {
|
|
if (!data)
|
|
continue;
|
|
desc = irq_data_to_desc(data);
|
|
if (!desc || is_timer_irq(desc))
|
|
continue;
|
|
irq_set_status_flags(irq, IRQ_DISABLE_UNLAZY);
|
|
disable_irq_nosync(irq);
|
|
}
|
|
}
|
|
|
|
static void resume_all_device_irqs(void)
|
|
{
|
|
struct irq_data *data;
|
|
struct irq_desc *desc;
|
|
int irq;
|
|
|
|
for (irq = 0, data = irq_get_irq_data(irq); irq < nr_irqs;
|
|
irq++, data = irq_get_irq_data(irq)) {
|
|
if (!data)
|
|
continue;
|
|
desc = irq_data_to_desc(data);
|
|
if (!desc || is_timer_irq(desc))
|
|
continue;
|
|
enable_irq(desc->irq_data.irq);
|
|
irq_clear_status_flags(irq, IRQ_DISABLE_UNLAZY);
|
|
}
|
|
}
|
|
|
|
static int forced_idle_write(void *data, u64 val)
|
|
{
|
|
struct cpuidle_state *idle_state = (struct cpuidle_state *) data;
|
|
int ret = 0;
|
|
u64 duration_ns = US_TO_NS(val);
|
|
|
|
suspend_all_device_irqs();
|
|
/* duration_ns, latency_ns */
|
|
play_idle_precise(duration_ns, (u64) (idle_state->exit_latency_ns));
|
|
resume_all_device_irqs();
|
|
|
|
return ret;
|
|
}
|
|
|
|
DEFINE_SIMPLE_ATTRIBUTE(idle_state_fops, NULL, forced_idle_write, "%llu\n");
|
|
|
|
static struct dentry *cpuidle_debugfs_node;
|
|
|
|
static int init_debugfs(void)
|
|
{
|
|
int i;
|
|
|
|
cpuidle_debugfs_node = debugfs_create_dir("cpuidle_debug", NULL);
|
|
if (!cpuidle_debugfs_node)
|
|
goto err_out;
|
|
|
|
for (i = 0; i < drv->state_count; i++) {
|
|
debugfs_create_file(drv->states[i].name, 0200,
|
|
cpuidle_debugfs_node, &(drv->states[i]), &idle_state_fops);
|
|
}
|
|
return 0;
|
|
|
|
err_out:
|
|
pr_err("%s: Couldn't create debugfs node for cpuidle\n", __func__);
|
|
debugfs_remove_recursive(cpuidle_debugfs_node);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
static int __init cpuidle_debugfs_probe(void)
|
|
{
|
|
drv = cpuidle_get_driver();
|
|
init_debugfs();
|
|
return 0;
|
|
}
|
|
|
|
static void __exit cpuidle_debugfs_remove(void)
|
|
{
|
|
debugfs_remove_recursive(cpuidle_debugfs_node);
|
|
}
|
|
|
|
module_init(cpuidle_debugfs_probe);
|
|
module_exit(cpuidle_debugfs_remove);
|
|
|
|
MODULE_AUTHOR("Ishan Shah <ishah@nvidia.com>");
|
|
MODULE_DESCRIPTION("cpuidle debugfs driver");
|
|
MODULE_LICENSE("GPL");
|