Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3)  * Copyright 2014  Google, Inc.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6) #include <linux/cdev.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7) #include <linux/device.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8) #include <linux/fs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9) #include <linux/uaccess.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include "internal.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) static DEFINE_MUTEX(pmsg_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) static ssize_t write_pmsg(struct file *file, const char __user *buf,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) 			  size_t count, loff_t *ppos)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) 	struct pstore_record record;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) 	int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) 	if (!count)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) 	pstore_record_init(&record, psinfo);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) 	record.type = PSTORE_TYPE_PMSG;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) 	record.size = count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) 	/* check outside lock, page in any data. write_user also checks */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) 	if (!access_ok(buf, count))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) 		return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) 	mutex_lock(&pmsg_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) 	ret = psinfo->write_user(&record, buf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) 	mutex_unlock(&pmsg_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) 	return ret ? ret : count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) static const struct file_operations pmsg_fops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) 	.owner		= THIS_MODULE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) 	.llseek		= noop_llseek,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) 	.write		= write_pmsg,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) static struct class *pmsg_class;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) static int pmsg_major;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) #define PMSG_NAME "pmsg"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) #undef pr_fmt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) #define pr_fmt(fmt) PMSG_NAME ": " fmt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) static char *pmsg_devnode(struct device *dev, umode_t *mode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) 	if (mode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) 		*mode = 0220;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) 	return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) void pstore_register_pmsg(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) 	struct device *pmsg_device;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) 	pmsg_major = register_chrdev(0, PMSG_NAME, &pmsg_fops);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) 	if (pmsg_major < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) 		pr_err("register_chrdev failed\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) 		goto err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) 	pmsg_class = class_create(THIS_MODULE, PMSG_NAME);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) 	if (IS_ERR(pmsg_class)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) 		pr_err("device class file already in use\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) 		goto err_class;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) 	pmsg_class->devnode = pmsg_devnode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) 	pmsg_device = device_create(pmsg_class, NULL, MKDEV(pmsg_major, 0),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) 					NULL, "%s%d", PMSG_NAME, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) 	if (IS_ERR(pmsg_device)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) 		pr_err("failed to create device\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) 		goto err_device;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) 	return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) err_device:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) 	class_destroy(pmsg_class);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) err_class:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) 	unregister_chrdev(pmsg_major, PMSG_NAME);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) err:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) 	return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) void pstore_unregister_pmsg(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) 	device_destroy(pmsg_class, MKDEV(pmsg_major, 0));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) 	class_destroy(pmsg_class);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) 	unregister_chrdev(pmsg_major, PMSG_NAME);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) }