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