1// SPDX-License-Identifier: GPL-2.0-only
2#include <linux/types.h>
3#include <linux/init.h>
4#include <linux/libfdt.h>
5#include <linux/string.h>
6#include <asm/pgtable.h>
7#include <asm/setup.h>
8
9static char early_cmdline[COMMAND_LINE_SIZE];
10
11/*
12 * Declare the functions that are exported (but prefixed) here so that LLVM
13 * does not complain it lacks the 'static' keyword (which, if added, makes
14 * LLVM complain because the function is actually unused in this file).
15 */
16u64 set_satp_mode_from_cmdline(uintptr_t dtb_pa);
17bool set_nokaslr_from_cmdline(uintptr_t dtb_pa);
18
19static char *get_early_cmdline(uintptr_t dtb_pa)
20{
21	const char *fdt_cmdline = NULL;
22	unsigned int fdt_cmdline_size = 0;
23	int chosen_node;
24
25	if (!IS_ENABLED(CONFIG_CMDLINE_FORCE)) {
26		chosen_node = fdt_path_offset((void *)dtb_pa, "/chosen");
27		if (chosen_node >= 0) {
28			fdt_cmdline = fdt_getprop((void *)dtb_pa, chosen_node,
29						  "bootargs", NULL);
30			if (fdt_cmdline) {
31				fdt_cmdline_size = strlen(fdt_cmdline);
32				strscpy(early_cmdline, fdt_cmdline,
33					COMMAND_LINE_SIZE);
34			}
35		}
36	}
37
38	if (IS_ENABLED(CONFIG_CMDLINE_EXTEND) ||
39	    IS_ENABLED(CONFIG_CMDLINE_FORCE) ||
40	    fdt_cmdline_size == 0 /* CONFIG_CMDLINE_FALLBACK */) {
41		strlcat(early_cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
42	}
43
44	return early_cmdline;
45}
46
47static u64 match_noXlvl(char *cmdline)
48{
49	if (strstr(cmdline, "no4lvl"))
50		return SATP_MODE_48;
51	else if (strstr(cmdline, "no5lvl"))
52		return SATP_MODE_57;
53
54	return 0;
55}
56
57u64 set_satp_mode_from_cmdline(uintptr_t dtb_pa)
58{
59	char *cmdline = get_early_cmdline(dtb_pa);
60
61	return match_noXlvl(cmdline);
62}
63
64static bool match_nokaslr(char *cmdline)
65{
66	return strstr(cmdline, "nokaslr");
67}
68
69bool set_nokaslr_from_cmdline(uintptr_t dtb_pa)
70{
71	char *cmdline = get_early_cmdline(dtb_pa);
72
73	return match_nokaslr(cmdline);
74}
75