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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * memconsole.c4 *5 * Architecture-independent parts of the memory based BIOS console.6 *7 * Copyright 2017 Google Inc.8 */9 10#include <linux/sysfs.h>11#include <linux/kobject.h>12#include <linux/module.h>13 14#include "memconsole.h"15 16static ssize_t memconsole_read(struct file *filp, struct kobject *kobp,17 struct bin_attribute *bin_attr, char *buf,18 loff_t pos, size_t count)19{20 ssize_t (*memconsole_read_func)(char *, loff_t, size_t);21 22 memconsole_read_func = bin_attr->private;23 if (WARN_ON_ONCE(!memconsole_read_func))24 return -EIO;25 26 return memconsole_read_func(buf, pos, count);27}28 29static struct bin_attribute memconsole_bin_attr = {30 .attr = {.name = "log", .mode = 0444},31 .read = memconsole_read,32};33 34void memconsole_setup(ssize_t (*read_func)(char *, loff_t, size_t))35{36 memconsole_bin_attr.private = read_func;37}38EXPORT_SYMBOL(memconsole_setup);39 40int memconsole_sysfs_init(void)41{42 return sysfs_create_bin_file(firmware_kobj, &memconsole_bin_attr);43}44EXPORT_SYMBOL(memconsole_sysfs_init);45 46void memconsole_exit(void)47{48 sysfs_remove_bin_file(firmware_kobj, &memconsole_bin_attr);49}50EXPORT_SYMBOL(memconsole_exit);51 52MODULE_AUTHOR("Google, Inc.");53MODULE_DESCRIPTION("Architecture-independent parts of the memory based BIOS console");54MODULE_LICENSE("GPL");55