xref: /openbmc/u-boot/arch/arm/cpu/armv8/spin_table.c (revision 12308b12)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2016 Socionext Inc.
4  *   Author: Masahiro Yamada <yamada.masahiro@socionext.com>
5  */
6 
7 #include <common.h>
8 #include <linux/libfdt.h>
9 #include <asm/spin_table.h>
10 
11 int spin_table_update_dt(void *fdt)
12 {
13 	int cpus_offset, offset;
14 	const char *prop;
15 	int ret;
16 	unsigned long rsv_addr = (unsigned long)&spin_table_reserve_begin;
17 	unsigned long rsv_size = &spin_table_reserve_end -
18 						&spin_table_reserve_begin;
19 
20 	cpus_offset = fdt_path_offset(fdt, "/cpus");
21 	if (cpus_offset < 0)
22 		return -ENODEV;
23 
24 	for (offset = fdt_first_subnode(fdt, cpus_offset);
25 	     offset >= 0;
26 	     offset = fdt_next_subnode(fdt, offset)) {
27 		prop = fdt_getprop(fdt, offset, "device_type", NULL);
28 		if (!prop || strcmp(prop, "cpu"))
29 			continue;
30 
31 		/*
32 		 * In the first loop, we check if every CPU node specifies
33 		 * spin-table.  Otherwise, just return successfully to not
34 		 * disturb other methods, like psci.
35 		 */
36 		prop = fdt_getprop(fdt, offset, "enable-method", NULL);
37 		if (!prop || strcmp(prop, "spin-table"))
38 			return 0;
39 	}
40 
41 	for (offset = fdt_first_subnode(fdt, cpus_offset);
42 	     offset >= 0;
43 	     offset = fdt_next_subnode(fdt, offset)) {
44 		prop = fdt_getprop(fdt, offset, "device_type", NULL);
45 		if (!prop || strcmp(prop, "cpu"))
46 			continue;
47 
48 		ret = fdt_setprop_u64(fdt, offset, "cpu-release-addr",
49 				(unsigned long)&spin_table_cpu_release_addr);
50 		if (ret)
51 			return -ENOSPC;
52 	}
53 
54 	ret = fdt_add_mem_rsv(fdt, rsv_addr, rsv_size);
55 	if (ret)
56 		return -ENOSPC;
57 
58 	printf("   Reserved memory region for spin-table: addr=%lx size=%lx\n",
59 	       rsv_addr, rsv_size);
60 
61 	return 0;
62 }
63