1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2002 ARM Ltd. 4 * All Rights Reserved 5 */ 6 #include <linux/init.h> 7 #include <linux/errno.h> 8 #include <linux/smp.h> 9 #include <linux/io.h> 10 #include <linux/of_address.h> 11 #include <linux/vexpress.h> 12 13 #include <asm/mcpm.h> 14 #include <asm/smp_scu.h> 15 #include <asm/mach/map.h> 16 17 #include "platsmp.h" 18 #include "vexpress.h" 19 20 bool __init vexpress_smp_init_ops(void) 21 { 22 #ifdef CONFIG_MCPM 23 int cpu; 24 struct device_node *cpu_node, *cci_node; 25 26 /* 27 * The best way to detect a multi-cluster configuration 28 * is to detect if the kernel can take over CCI ports 29 * control. Loop over possible CPUs and check if CCI 30 * port control is available. 31 * Override the default vexpress_smp_ops if so. 32 */ 33 for_each_possible_cpu(cpu) { 34 bool available; 35 36 cpu_node = of_get_cpu_node(cpu, NULL); 37 if (WARN(!cpu_node, "Missing cpu device node!")) 38 return false; 39 40 cci_node = of_parse_phandle(cpu_node, "cci-control-port", 0); 41 available = cci_node && of_device_is_available(cci_node); 42 of_node_put(cci_node); 43 of_node_put(cpu_node); 44 45 if (!available) 46 return false; 47 } 48 49 mcpm_smp_set_ops(); 50 return true; 51 #else 52 return false; 53 #endif 54 } 55 56 static const struct of_device_id vexpress_smp_dt_scu_match[] __initconst = { 57 { .compatible = "arm,cortex-a5-scu", }, 58 { .compatible = "arm,cortex-a9-scu", }, 59 {} 60 }; 61 62 static void __init vexpress_smp_dt_prepare_cpus(unsigned int max_cpus) 63 { 64 struct device_node *scu = of_find_matching_node(NULL, 65 vexpress_smp_dt_scu_match); 66 67 if (scu) 68 scu_enable(of_iomap(scu, 0)); 69 70 /* 71 * Write the address of secondary startup into the 72 * system-wide flags register. The boot monitor waits 73 * until it receives a soft interrupt, and then the 74 * secondary CPU branches to this address. 75 */ 76 vexpress_flags_set(__pa_symbol(versatile_secondary_startup)); 77 } 78 79 #ifdef CONFIG_HOTPLUG_CPU 80 static void vexpress_cpu_die(unsigned int cpu) 81 { 82 versatile_immitation_cpu_die(cpu, 0x40); 83 } 84 #endif 85 86 const struct smp_operations vexpress_smp_dt_ops __initconst = { 87 .smp_prepare_cpus = vexpress_smp_dt_prepare_cpus, 88 .smp_secondary_init = versatile_secondary_init, 89 .smp_boot_secondary = versatile_boot_secondary, 90 #ifdef CONFIG_HOTPLUG_CPU 91 .cpu_die = vexpress_cpu_die, 92 #endif 93 }; 94