mirror_ubuntu-kernels/drivers/interconnect/debugfs-client.c

169 lines
3.6 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2023, Qualcomm Innovation Center, Inc. All rights reserved.
*/
#include <linux/debugfs.h>
#include <linux/interconnect.h>
#include <linux/platform_device.h>
#include "internal.h"
/*
* This can be dangerous, therefore don't provide any real compile time
* configuration option for this feature.
* People who want to use this will need to modify the source code directly.
*/
#undef INTERCONNECT_ALLOW_WRITE_DEBUGFS
#if defined(INTERCONNECT_ALLOW_WRITE_DEBUGFS) && defined(CONFIG_DEBUG_FS)
static LIST_HEAD(debugfs_paths);
static DEFINE_MUTEX(debugfs_lock);
static struct platform_device *pdev;
static struct icc_path *cur_path;
static char *src_node;
static char *dst_node;
static u32 avg_bw;
static u32 peak_bw;
static u32 tag;
struct debugfs_path {
const char *src;
const char *dst;
struct icc_path *path;
struct list_head list;
};
static struct icc_path *get_path(const char *src, const char *dst)
{
struct debugfs_path *path;
list_for_each_entry(path, &debugfs_paths, list) {
if (!strcmp(path->src, src) && !strcmp(path->dst, dst))
return path->path;
}
return NULL;
}
static int icc_get_set(void *data, u64 val)
{
struct debugfs_path *debugfs_path;
char *src, *dst;
int ret = 0;
mutex_lock(&debugfs_lock);
rcu_read_lock();
src = rcu_dereference(src_node);
dst = rcu_dereference(dst_node);
/*
* If we've already looked up a path, then use the existing one instead
* of calling icc_get() again. This allows for updating previous BW
* votes when "get" is written to multiple times for multiple paths.
*/
cur_path = get_path(src, dst);
if (cur_path) {
rcu_read_unlock();
goto out;
}
src = kstrdup(src, GFP_ATOMIC);
dst = kstrdup(dst, GFP_ATOMIC);
rcu_read_unlock();
if (!src || !dst) {
ret = -ENOMEM;
goto err_free;
}
cur_path = icc_get(&pdev->dev, src, dst);
if (IS_ERR(cur_path)) {
ret = PTR_ERR(cur_path);
goto err_free;
}
debugfs_path = kzalloc(sizeof(*debugfs_path), GFP_KERNEL);
if (!debugfs_path) {
ret = -ENOMEM;
goto err_put;
}
debugfs_path->path = cur_path;
debugfs_path->src = src;
debugfs_path->dst = dst;
list_add_tail(&debugfs_path->list, &debugfs_paths);
goto out;
err_put:
icc_put(cur_path);
err_free:
kfree(src);
kfree(dst);
out:
mutex_unlock(&debugfs_lock);
return ret;
}
DEFINE_DEBUGFS_ATTRIBUTE(icc_get_fops, NULL, icc_get_set, "%llu\n");
static int icc_commit_set(void *data, u64 val)
{
int ret;
mutex_lock(&debugfs_lock);
if (IS_ERR_OR_NULL(cur_path)) {
ret = PTR_ERR(cur_path);
goto out;
}
icc_set_tag(cur_path, tag);
ret = icc_set_bw(cur_path, avg_bw, peak_bw);
out:
mutex_unlock(&debugfs_lock);
return ret;
}
DEFINE_DEBUGFS_ATTRIBUTE(icc_commit_fops, NULL, icc_commit_set, "%llu\n");
int icc_debugfs_client_init(struct dentry *icc_dir)
{
struct dentry *client_dir;
int ret;
pdev = platform_device_alloc("icc-debugfs-client", PLATFORM_DEVID_NONE);
ret = platform_device_add(pdev);
if (ret) {
pr_err("%s: failed to add platform device: %d\n", __func__, ret);
platform_device_put(pdev);
return ret;
}
client_dir = debugfs_create_dir("test_client", icc_dir);
debugfs_create_str("src_node", 0600, client_dir, &src_node);
debugfs_create_str("dst_node", 0600, client_dir, &dst_node);
debugfs_create_file("get", 0200, client_dir, NULL, &icc_get_fops);
debugfs_create_u32("avg_bw", 0600, client_dir, &avg_bw);
debugfs_create_u32("peak_bw", 0600, client_dir, &peak_bw);
debugfs_create_u32("tag", 0600, client_dir, &tag);
debugfs_create_file("commit", 0200, client_dir, NULL, &icc_commit_fops);
return 0;
}
#else
int icc_debugfs_client_init(struct dentry *icc_dir)
{
return 0;
}
#endif