linux-stable/drivers/dca/dca-sysfs.c
Ivan Orlov d7d3ae441e dca: make dca_class a static const structure
The driver core allows for struct class to be in read-only memory. Move
the dca_class structure to be declared at build time placing it into
read-only memory, instead of having to be dynamically allocated at boot
time.

Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Link: https://lore.kernel.org/r/20240412151726.189030-1-ivan.orlov0322@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-10 10:22:20 +02:00

95 lines
1.8 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright(c) 2007 - 2009 Intel Corporation. All rights reserved.
*/
#include <linux/kernel.h>
#include <linux/spinlock.h>
#include <linux/device.h>
#include <linux/idr.h>
#include <linux/kdev_t.h>
#include <linux/err.h>
#include <linux/dca.h>
#include <linux/gfp.h>
#include <linux/export.h>
static const struct class dca_class = {
.name = "dca",
};
static struct idr dca_idr;
static spinlock_t dca_idr_lock;
int dca_sysfs_add_req(struct dca_provider *dca, struct device *dev, int slot)
{
struct device *cd;
static int req_count;
cd = device_create(&dca_class, dca->cd, MKDEV(0, slot + 1), NULL,
"requester%d", req_count++);
return PTR_ERR_OR_ZERO(cd);
}
void dca_sysfs_remove_req(struct dca_provider *dca, int slot)
{
device_destroy(&dca_class, MKDEV(0, slot + 1));
}
int dca_sysfs_add_provider(struct dca_provider *dca, struct device *dev)
{
struct device *cd;
int ret;
idr_preload(GFP_KERNEL);
spin_lock(&dca_idr_lock);
ret = idr_alloc(&dca_idr, dca, 0, 0, GFP_NOWAIT);
if (ret >= 0)
dca->id = ret;
spin_unlock(&dca_idr_lock);
idr_preload_end();
if (ret < 0)
return ret;
cd = device_create(&dca_class, dev, MKDEV(0, 0), NULL, "dca%d", dca->id);
if (IS_ERR(cd)) {
spin_lock(&dca_idr_lock);
idr_remove(&dca_idr, dca->id);
spin_unlock(&dca_idr_lock);
return PTR_ERR(cd);
}
dca->cd = cd;
return 0;
}
void dca_sysfs_remove_provider(struct dca_provider *dca)
{
device_unregister(dca->cd);
dca->cd = NULL;
spin_lock(&dca_idr_lock);
idr_remove(&dca_idr, dca->id);
spin_unlock(&dca_idr_lock);
}
int __init dca_sysfs_init(void)
{
int err;
idr_init(&dca_idr);
spin_lock_init(&dca_idr_lock);
err = class_register(&dca_class);
if (err) {
idr_destroy(&dca_idr);
return err;
}
return 0;
}
void __exit dca_sysfs_exit(void)
{
class_unregister(&dca_class);
idr_destroy(&dca_idr);
}