xref: /openbmc/linux/arch/arm/mach-aspeed/platsmp.c (revision 0c6dfa75)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 // Copyright (C) ASPEED Technology Inc.
3 // Copyright IBM Corp.
4 
5 #include <linux/of_address.h>
6 #include <linux/io.h>
7 #include <linux/of.h>
8 #include <linux/smp.h>
9 
10 #define BOOT_ADDR	0x00
11 #define BOOT_SIG	0x04
12 
13 static struct device_node *secboot_node;
14 
15 static int aspeed_g6_boot_secondary(unsigned int cpu, struct task_struct *idle)
16 {
17 	void __iomem *base;
18 
19 	base = of_iomap(secboot_node, 0);
20 	if (!base) {
21 		pr_err("could not map the secondary boot base!");
22 		return -ENODEV;
23 	}
24 
25 	writel_relaxed(0, base + BOOT_ADDR);
26 	writel_relaxed(__pa_symbol(secondary_startup_arm), base + BOOT_ADDR);
27 	writel_relaxed((0xABBAAB00 | (cpu & 0xff)), base + BOOT_SIG);
28 
29 	dsb_sev();
30 
31 	iounmap(base);
32 
33 	return 0;
34 }
35 
36 static void __init aspeed_g6_smp_prepare_cpus(unsigned int max_cpus)
37 {
38 	void __iomem *base;
39 
40 	secboot_node = of_find_compatible_node(NULL, NULL, "aspeed,ast2600-smpmem");
41 	if (!secboot_node) {
42 		pr_err("secboot device node found!!\n");
43 		return;
44 	}
45 
46 	base = of_iomap(secboot_node, 0);
47 	if (!base) {
48 		pr_err("could not map the secondary boot base!");
49 		return;
50 	}
51 	__raw_writel(0xBADABABA, base + BOOT_SIG);
52 
53 	iounmap(base);
54 }
55 
56 static const struct smp_operations aspeed_smp_ops __initconst = {
57 	.smp_prepare_cpus	= aspeed_g6_smp_prepare_cpus,
58 	.smp_boot_secondary	= aspeed_g6_boot_secondary,
59 };
60 
61 CPU_METHOD_OF_DECLARE(aspeed_smp, "aspeed,ast2600-smp", &aspeed_smp_ops);
62