1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2002 ARM Ltd.
4 * Copyright (C) 2008 STMicroelctronics.
5 * Copyright (C) 2009 ST-Ericsson.
6 * Author: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
7 *
8 * This file is based on arm realview platform
9 */
10#include <linux/init.h>
11#include <linux/errno.h>
12#include <linux/delay.h>
13#include <linux/device.h>
14#include <linux/smp.h>
15#include <linux/io.h>
16#include <linux/of.h>
17#include <linux/of_address.h>
18
19#include <asm/cacheflush.h>
20#include <asm/smp_plat.h>
21#include <asm/smp_scu.h>
22
23/* Magic triggers in backup RAM */
24#define UX500_CPU1_JUMPADDR_OFFSET 0x1FF4
25#define UX500_CPU1_WAKEMAGIC_OFFSET 0x1FF0
26
27static void __iomem *backupram;
28
29static void __init ux500_smp_prepare_cpus(unsigned int max_cpus)
30{
31 struct device_node *np;
32 static void __iomem *scu_base;
33 unsigned int ncores;
34 int i;
35
36 np = of_find_compatible_node(NULL, NULL, compat: "ste,dbx500-backupram");
37 if (!np) {
38 pr_err("No backupram base address\n");
39 return;
40 }
41 backupram = of_iomap(node: np, index: 0);
42 of_node_put(node: np);
43 if (!backupram) {
44 pr_err("No backupram remap\n");
45 return;
46 }
47
48 np = of_find_compatible_node(NULL, NULL, compat: "arm,cortex-a9-scu");
49 if (!np) {
50 pr_err("No SCU base address\n");
51 return;
52 }
53 scu_base = of_iomap(node: np, index: 0);
54 of_node_put(node: np);
55 if (!scu_base) {
56 pr_err("No SCU remap\n");
57 return;
58 }
59
60 scu_enable(scu_base);
61 ncores = scu_get_core_count(scu_base);
62 for (i = 0; i < ncores; i++)
63 set_cpu_possible(cpu: i, possible: true);
64 iounmap(addr: scu_base);
65}
66
67static int ux500_boot_secondary(unsigned int cpu, struct task_struct *idle)
68{
69 /*
70 * write the address of secondary startup into the backup ram register
71 * at offset 0x1FF4, then write the magic number 0xA1FEED01 to the
72 * backup ram register at offset 0x1FF0, which is what boot rom code
73 * is waiting for. This will wake up the secondary core from WFE.
74 */
75 writel(__pa_symbol(secondary_startup),
76 backupram + UX500_CPU1_JUMPADDR_OFFSET);
77 writel(val: 0xA1FEED01,
78 addr: backupram + UX500_CPU1_WAKEMAGIC_OFFSET);
79
80 /* make sure write buffer is drained */
81 mb();
82 arch_send_wakeup_ipi_mask(cpumask_of(cpu));
83 return 0;
84}
85
86#ifdef CONFIG_HOTPLUG_CPU
87static void ux500_cpu_die(unsigned int cpu)
88{
89 wfi();
90}
91#endif
92
93static const struct smp_operations ux500_smp_ops __initconst = {
94 .smp_prepare_cpus = ux500_smp_prepare_cpus,
95 .smp_boot_secondary = ux500_boot_secondary,
96#ifdef CONFIG_HOTPLUG_CPU
97 .cpu_die = ux500_cpu_die,
98#endif
99};
100CPU_METHOD_OF_DECLARE(ux500_smp, "ste,dbx500-smp", &ux500_smp_ops);
101

source code of linux/arch/arm/mach-ux500/platsmp.c