Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0-only
/*
 * DMA-BUF sysfs statistics.
 *
 * Copyright (C) 2021 Google LLC.
 */
 
#include <linux/dma-buf.h>
#include <linux/dma-resv.h>
#include <linux/kobject.h>
#include <linux/printk.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
 
#include "dma-buf-sysfs-stats.h"
 
#define to_dma_buf_entry_from_kobj(x) container_of(x, struct dma_buf_sysfs_entry, kobj)
 
struct dma_buf_stats_attribute {
<------>struct attribute attr;
<------>ssize_t (*show)(struct dma_buf *dmabuf,
<------><------><------>struct dma_buf_stats_attribute *attr, char *buf);
};
#define to_dma_buf_stats_attr(x) container_of(x, struct dma_buf_stats_attribute, attr)
 
static ssize_t dma_buf_stats_attribute_show(struct kobject *kobj,
<------><------><------><------><------>    struct attribute *attr,
<------><------><------><------><------>    char *buf)
{
<------>struct dma_buf_stats_attribute *attribute;
<------>struct dma_buf_sysfs_entry *sysfs_entry;
<------>struct dma_buf *dmabuf;
 
<------>attribute = to_dma_buf_stats_attr(attr);
<------>sysfs_entry = to_dma_buf_entry_from_kobj(kobj);
<------>dmabuf = sysfs_entry->dmabuf;
 
<------>if (!dmabuf || !attribute->show)
<------><------>return -EIO;
 
<------>return attribute->show(dmabuf, attribute, buf);
}
 
static const struct sysfs_ops dma_buf_stats_sysfs_ops = {
<------>.show = dma_buf_stats_attribute_show,
};
 
static ssize_t exporter_name_show(struct dma_buf *dmabuf,
<------><------><------><------>  struct dma_buf_stats_attribute *attr,
<------><------><------><------>  char *buf)
{
<------>return sysfs_emit(buf, "%s\n", dmabuf->exp_name);
}
 
static ssize_t size_show(struct dma_buf *dmabuf,
<------><------><------> struct dma_buf_stats_attribute *attr,
<------><------><------> char *buf)
{
<------>return sysfs_emit(buf, "%zu\n", dmabuf->size);
}
 
static struct dma_buf_stats_attribute exporter_name_attribute =
<------>__ATTR_RO(exporter_name);
static struct dma_buf_stats_attribute size_attribute = __ATTR_RO(size);
 
static struct attribute *dma_buf_stats_default_attrs[] = {
<------>&exporter_name_attribute.attr,
<------>&size_attribute.attr,
<------>NULL,
};
ATTRIBUTE_GROUPS(dma_buf_stats_default);
 
static void dma_buf_sysfs_release(struct kobject *kobj)
{
<------>struct dma_buf_sysfs_entry *sysfs_entry;
 
<------>sysfs_entry = to_dma_buf_entry_from_kobj(kobj);
<------>kfree(sysfs_entry);
}
 
static struct kobj_type dma_buf_ktype = {
<------>.sysfs_ops = &dma_buf_stats_sysfs_ops,
<------>.release = dma_buf_sysfs_release,
<------>.default_groups = dma_buf_stats_default_groups,
};
 
void dma_buf_stats_teardown(struct dma_buf *dmabuf)
{
<------>struct dma_buf_sysfs_entry *sysfs_entry;
 
<------>sysfs_entry = dmabuf->sysfs_entry;
<------>if (!sysfs_entry)
<------><------>return;
 
<------>kobject_del(&sysfs_entry->kobj);
<------>kobject_put(&sysfs_entry->kobj);
}
 
/*
 * Statistics files do not need to send uevents.
 */
static int dmabuf_sysfs_uevent_filter(struct kset *kset, struct kobject *kobj)
{
<------>return 0;
}
 
static const struct kset_uevent_ops dmabuf_sysfs_no_uevent_ops = {
<------>.filter = dmabuf_sysfs_uevent_filter,
};
 
static struct kset *dma_buf_stats_kset;
static struct kset *dma_buf_per_buffer_stats_kset;
int dma_buf_init_sysfs_statistics(void)
{
<------>dma_buf_stats_kset = kset_create_and_add("dmabuf",
<------><------><------><------><------><------> &dmabuf_sysfs_no_uevent_ops,
<------><------><------><------><------><------> kernel_kobj);
<------>if (!dma_buf_stats_kset)
<------><------>return -ENOMEM;
 
<------>dma_buf_per_buffer_stats_kset = kset_create_and_add("buffers",
<------><------><------><------><------><------><------>    &dmabuf_sysfs_no_uevent_ops,
<------><------><------><------><------><------><------>    &dma_buf_stats_kset->kobj);
<------>if (!dma_buf_per_buffer_stats_kset) {
<------><------>kset_unregister(dma_buf_stats_kset);
<------><------>return -ENOMEM;
<------>}
 
<------>return 0;
}
 
void dma_buf_uninit_sysfs_statistics(void)
{
<------>kset_unregister(dma_buf_per_buffer_stats_kset);
<------>kset_unregister(dma_buf_stats_kset);
}
 
int dma_buf_stats_setup(struct dma_buf *dmabuf)
{
<------>struct dma_buf_sysfs_entry *sysfs_entry;
<------>int ret;
 
<------>if (!dmabuf || !dmabuf->file)
<------><------>return -EINVAL;
 
<------>if (!dmabuf->exp_name) {
<------><------>pr_err("exporter name must not be empty if stats needed\n");
<------><------>return -EINVAL;
<------>}
 
<------>sysfs_entry = kzalloc(sizeof(struct dma_buf_sysfs_entry), GFP_KERNEL);
<------>if (!sysfs_entry)
<------><------>return -ENOMEM;
 
<------>sysfs_entry->kobj.kset = dma_buf_per_buffer_stats_kset;
<------>sysfs_entry->dmabuf = dmabuf;
 
<------>dmabuf->sysfs_entry = sysfs_entry;
 
<------>/* create the directory for buffer stats */
<------>ret = kobject_init_and_add(&sysfs_entry->kobj, &dma_buf_ktype, NULL,
<------><------><------><------>   "%lu", file_inode(dmabuf->file)->i_ino);
<------>if (ret)
<------><------>goto err_sysfs_dmabuf;
 
<------>return 0;
 
err_sysfs_dmabuf:
<------>kobject_put(&sysfs_entry->kobj);
<------>dmabuf->sysfs_entry = NULL;
<------>return ret;
}