1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2014 Marvell Technology Group Ltd.
4 *
5 * Antoine Ténart <antoine.tenart@free-electrons.com>
6 */
7
8 #include <linux/io.h>
9 #include <linux/delay.h>
10 #include <linux/of.h>
11 #include <linux/of_address.h>
12
13 #include <asm/cacheflush.h>
14 #include <asm/cp15.h>
15 #include <asm/page.h>
16 #include <asm/smp_plat.h>
17 #include <asm/smp_scu.h>
18
19 /*
20 * There are two reset registers, one with self-clearing (SC)
21 * reset and one with non-self-clearing reset (NON_SC).
22 */
23 #define CPU_RESET_SC 0x00
24 #define CPU_RESET_NON_SC 0x20
25
26 #define RESET_VECT 0x00
27 #define SW_RESET_ADDR 0x94
28
29 extern u32 boot_inst;
30
31 static void __iomem *cpu_ctrl;
32
33 static inline void berlin_perform_reset_cpu(unsigned int cpu)
34 {
35 u32 val;
36
37 val = readl(cpu_ctrl + CPU_RESET_NON_SC);
38 val &= ~BIT(cpu_logical_map(cpu));
39 writel(val, cpu_ctrl + CPU_RESET_NON_SC);
40 val |= BIT(cpu_logical_map(cpu));
41 writel(val, cpu_ctrl + CPU_RESET_NON_SC);
42 }
43
44 static int berlin_boot_secondary(unsigned int cpu, struct task_struct *idle)
45 {
46 if (!cpu_ctrl)
47 return -EFAULT;
48
49 /*
50 * Reset the CPU, making it to execute the instruction in the reset
51 * exception vector.
52 */
53 berlin_perform_reset_cpu(cpu);
54
55 return 0;
56 }
57
58 static void __init berlin_smp_prepare_cpus(unsigned int max_cpus)
59 {
60 struct device_node *np;
61 void __iomem *scu_base;
62 void __iomem *vectors_base;
63
64 np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu");
65 scu_base = of_iomap(np, 0);
66 of_node_put(np);
67 if (!scu_base)
68 return;
69
70 np = of_find_compatible_node(NULL, NULL, "marvell,berlin-cpu-ctrl");
71 cpu_ctrl = of_iomap(np, 0);
72 of_node_put(np);
73 if (!cpu_ctrl)
74 goto unmap_scu;
75
76 vectors_base = ioremap(VECTORS_BASE, SZ_32K);
77 if (!vectors_base)
78 goto unmap_scu;
79
80 scu_enable(scu_base);
81
82 /*
83 * Write the first instruction the CPU will execute after being reset
84 * in the reset exception vector.
85 */
86 writel(boot_inst, vectors_base + RESET_VECT);
87
88 /*
89 * Write the secondary startup address into the SW reset address
90 * vector. This is used by boot_inst.
91 */
92 writel(__pa_symbol(secondary_startup), vectors_base + SW_RESET_ADDR);
93
94 iounmap(vectors_base);
95 unmap_scu:
96 iounmap(scu_base);
97 }
98
99 #ifdef CONFIG_HOTPLUG_CPU
100 static void berlin_cpu_die(unsigned int cpu)
101 {
102 v7_exit_coherency_flush(louis);
103 while (1)
104 cpu_do_idle();
105 }
106
107 static int berlin_cpu_kill(unsigned int cpu)
108 {
109 u32 val;
110
111 val = readl(cpu_ctrl + CPU_RESET_NON_SC);
112 val &= ~BIT(cpu_logical_map(cpu));
113 writel(val, cpu_ctrl + CPU_RESET_NON_SC);
114
115 return 1;
116 }
117 #endif
118
119 static const struct smp_operations berlin_smp_ops __initconst = {
120 .smp_prepare_cpus = berlin_smp_prepare_cpus,
121 .smp_boot_secondary = berlin_boot_secondary,
122 #ifdef CONFIG_HOTPLUG_CPU
123 .cpu_die = berlin_cpu_die,
124 .cpu_kill = berlin_cpu_kill,
125 #endif
126 };
127 CPU_METHOD_OF_DECLARE(berlin_smp, "marvell,berlin-smp", &berlin_smp_ops);
128
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