1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * memconsole.c |
4 | * |
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 | |
16 | static 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 | |
29 | static struct bin_attribute memconsole_bin_attr = { |
30 | .attr = {.name = "log" , .mode = 0444}, |
31 | .read = memconsole_read, |
32 | }; |
33 | |
34 | void memconsole_setup(ssize_t (*read_func)(char *, loff_t, size_t)) |
35 | { |
36 | memconsole_bin_attr.private = read_func; |
37 | } |
38 | EXPORT_SYMBOL(memconsole_setup); |
39 | |
40 | int memconsole_sysfs_init(void) |
41 | { |
42 | return sysfs_create_bin_file(kobj: firmware_kobj, attr: &memconsole_bin_attr); |
43 | } |
44 | EXPORT_SYMBOL(memconsole_sysfs_init); |
45 | |
46 | void memconsole_exit(void) |
47 | { |
48 | sysfs_remove_bin_file(kobj: firmware_kobj, attr: &memconsole_bin_attr); |
49 | } |
50 | EXPORT_SYMBOL(memconsole_exit); |
51 | |
52 | MODULE_AUTHOR("Google, Inc." ); |
53 | MODULE_LICENSE("GPL" ); |
54 | |