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  
9  #include "pi.h"
10  
11  static char early_cmdline[COMMAND_LINE_SIZE];
12  
get_early_cmdline(uintptr_t dtb_pa)13  static char *get_early_cmdline(uintptr_t dtb_pa)
14  {
15  	const char *fdt_cmdline = NULL;
16  	unsigned int fdt_cmdline_size = 0;
17  	int chosen_node;
18  
19  	if (!IS_ENABLED(CONFIG_CMDLINE_FORCE)) {
20  		chosen_node = fdt_path_offset((void *)dtb_pa, "/chosen");
21  		if (chosen_node >= 0) {
22  			fdt_cmdline = fdt_getprop((void *)dtb_pa, chosen_node,
23  						  "bootargs", NULL);
24  			if (fdt_cmdline) {
25  				fdt_cmdline_size = strlen(fdt_cmdline);
26  				strscpy(early_cmdline, fdt_cmdline,
27  					COMMAND_LINE_SIZE);
28  			}
29  		}
30  	}
31  
32  	if (IS_ENABLED(CONFIG_CMDLINE_EXTEND) ||
33  	    IS_ENABLED(CONFIG_CMDLINE_FORCE) ||
34  	    fdt_cmdline_size == 0 /* CONFIG_CMDLINE_FALLBACK */) {
35  		strlcat(early_cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
36  	}
37  
38  	return early_cmdline;
39  }
40  
match_noXlvl(char * cmdline)41  static u64 match_noXlvl(char *cmdline)
42  {
43  	if (strstr(cmdline, "no4lvl"))
44  		return SATP_MODE_48;
45  	else if (strstr(cmdline, "no5lvl"))
46  		return SATP_MODE_57;
47  
48  	return 0;
49  }
50  
set_satp_mode_from_cmdline(uintptr_t dtb_pa)51  u64 set_satp_mode_from_cmdline(uintptr_t dtb_pa)
52  {
53  	char *cmdline = get_early_cmdline(dtb_pa);
54  
55  	return match_noXlvl(cmdline);
56  }
57  
match_nokaslr(char * cmdline)58  static bool match_nokaslr(char *cmdline)
59  {
60  	return strstr(cmdline, "nokaslr");
61  }
62  
set_nokaslr_from_cmdline(uintptr_t dtb_pa)63  bool set_nokaslr_from_cmdline(uintptr_t dtb_pa)
64  {
65  	char *cmdline = get_early_cmdline(dtb_pa);
66  
67  	return match_nokaslr(cmdline);
68  }
69