arch/riscv/kernel/pi/cmdline_early.c

   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
  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
  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
  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
  58 static bool match_nokaslr(char *cmdline)
  59 {
  60         return strstr(cmdline, "nokaslr");
  61 }
  62
  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 }