xref: /openbmc/u-boot/arch/arm/cpu/armv8/spin_table.c (revision be059e88)
1 /*
2  * Copyright (C) 2016 Socionext Inc.
3  *   Author: Masahiro Yamada <yamada.masahiro@socionext.com>
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  */
7 
8 #include <common.h>
9 #include <libfdt.h>
10 #include <asm/spin_table.h>
11 
12 int spin_table_update_dt(void *fdt)
13 {
14 	int cpus_offset, offset;
15 	const char *prop;
16 	int ret;
17 	unsigned long rsv_addr = (unsigned long)&spin_table_reserve_begin;
18 	unsigned long rsv_size = &spin_table_reserve_end -
19 						&spin_table_reserve_begin;
20 
21 	cpus_offset = fdt_path_offset(fdt, "/cpus");
22 	if (cpus_offset < 0)
23 		return -ENODEV;
24 
25 	for (offset = fdt_first_subnode(fdt, cpus_offset);
26 	     offset >= 0;
27 	     offset = fdt_next_subnode(fdt, offset)) {
28 		prop = fdt_getprop(fdt, offset, "device_type", NULL);
29 		if (!prop || strcmp(prop, "cpu"))
30 			continue;
31 
32 		/*
33 		 * In the first loop, we check if every CPU node specifies
34 		 * spin-table.  Otherwise, just return successfully to not
35 		 * disturb other methods, like psci.
36 		 */
37 		prop = fdt_getprop(fdt, offset, "enable-method", NULL);
38 		if (!prop || strcmp(prop, "spin-table"))
39 			return 0;
40 	}
41 
42 	for (offset = fdt_first_subnode(fdt, cpus_offset);
43 	     offset >= 0;
44 	     offset = fdt_next_subnode(fdt, offset)) {
45 		prop = fdt_getprop(fdt, offset, "device_type", NULL);
46 		if (!prop || strcmp(prop, "cpu"))
47 			continue;
48 
49 		ret = fdt_setprop_u64(fdt, offset, "cpu-release-addr",
50 				(unsigned long)&spin_table_cpu_release_addr);
51 		if (ret)
52 			return -ENOSPC;
53 	}
54 
55 	ret = fdt_add_mem_rsv(fdt, rsv_addr, rsv_size);
56 	if (ret)
57 		return -ENOSPC;
58 
59 	printf("   Reserved memory region for spin-table: addr=%lx size=%lx\n",
60 	       rsv_addr, rsv_size);
61 
62 	return 0;
63 }
64