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 static 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 */ 16 u64 set_satp_mode_from_cmdline(uintptr_t dtb_pa); 17 bool set_nokaslr_from_cmdline(uintptr_t dtb_pa); 18 19 static 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 47 static 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 57 u64 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 64 static bool match_nokaslr(char *cmdline) 65 { 66 return strstr(cmdline, "nokaslr"); 67 } 68 69 bool 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