arch/riscv/kernel/pi/archrandom_early.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2
   3 #include <asm/csr.h>
   4 #include <linux/processor.h>
   5
   6 #include "pi.h"
   7
   8 /*
   9  * To avoid rewriting code include asm/archrandom.h and create macros
  10  * for the functions that won't be included.
  11  */
  12 #undef riscv_has_extension_unlikely
  13 #define riscv_has_extension_likely(...) false
  14 #undef pr_err_once
  15 #define pr_err_once(...)
  16
  17 #include <asm/archrandom.h>
  18
  19 u64 get_kaslr_seed_zkr(const uintptr_t dtb_pa)
  20 {
  21         unsigned long seed = 0;
  22
  23         if (!fdt_early_match_extension_isa((const void *)dtb_pa, "zkr"))
  24                 return 0;
  25
  26         if (!csr_seed_long(&seed))
  27                 return 0;
  28
  29         return seed;
  30 }