xref: /linux/arch/riscv/kernel/pi/archrandom_early.c (revision 945302df3de156fc367d3b537cec76d4aea0b0d1)
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 }
31