1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2015 Linus Walleij 4 */ 5 #include <linux/smp.h> 6 #include <linux/io.h> 7 #include <linux/of.h> 8 #include <linux/of_address.h> 9 #include <linux/regmap.h> 10 #include <linux/mfd/syscon.h> 11 12 #include <asm/cacheflush.h> 13 #include <asm/smp_plat.h> 14 #include <asm/smp_scu.h> 15 16 #include "platsmp.h" 17 18 #define REALVIEW_SYS_FLAGSSET_OFFSET 0x30 19 20 static const struct of_device_id realview_scu_match[] = { 21 /* 22 * The ARM11MP SCU compatible is only provided as fallback for 23 * old RealView EB Cortex-A9 device trees that were using this 24 * compatible by mistake. 25 */ 26 { .compatible = "arm,arm11mp-scu", }, 27 { .compatible = "arm,cortex-a9-scu", }, 28 { .compatible = "arm,cortex-a5-scu", }, 29 { } 30 }; 31 32 static const struct of_device_id realview_syscon_match[] = { 33 { .compatible = "arm,core-module-integrator", }, 34 { .compatible = "arm,realview-eb-syscon", }, 35 { .compatible = "arm,realview-pbx-syscon", }, 36 { }, 37 }; 38 39 static void __init realview_smp_prepare_cpus(unsigned int max_cpus) 40 { 41 struct device_node *np; 42 void __iomem *scu_base; 43 struct regmap *map; 44 unsigned int ncores; 45 int i; 46 47 np = of_find_matching_node(NULL, realview_scu_match); 48 if (!np) { 49 pr_err("PLATSMP: No SCU base address\n"); 50 return; 51 } 52 scu_base = of_iomap(np, 0); 53 of_node_put(np); 54 if (!scu_base) { 55 pr_err("PLATSMP: No SCU remap\n"); 56 return; 57 } 58 59 scu_enable(scu_base); 60 ncores = scu_get_core_count(scu_base); 61 pr_info("SCU: %d cores detected\n", ncores); 62 for (i = 0; i < ncores; i++) 63 set_cpu_possible(i, true); 64 iounmap(scu_base); 65 66 /* The syscon contains the magic SMP start address registers */ 67 np = of_find_matching_node(NULL, realview_syscon_match); 68 if (!np) { 69 pr_err("PLATSMP: No syscon match\n"); 70 return; 71 } 72 map = syscon_node_to_regmap(np); 73 if (IS_ERR(map)) { 74 pr_err("PLATSMP: No syscon regmap\n"); 75 return; 76 } 77 /* Put the boot address in this magic register */ 78 regmap_write(map, REALVIEW_SYS_FLAGSSET_OFFSET, 79 __pa_symbol(versatile_secondary_startup)); 80 } 81 82 #ifdef CONFIG_HOTPLUG_CPU 83 static void realview_cpu_die(unsigned int cpu) 84 { 85 return versatile_immitation_cpu_die(cpu, 0x20); 86 } 87 #endif 88 89 static const struct smp_operations realview_dt_smp_ops __initconst = { 90 .smp_prepare_cpus = realview_smp_prepare_cpus, 91 .smp_secondary_init = versatile_secondary_init, 92 .smp_boot_secondary = versatile_boot_secondary, 93 #ifdef CONFIG_HOTPLUG_CPU 94 .cpu_die = realview_cpu_die, 95 #endif 96 }; 97 CPU_METHOD_OF_DECLARE(realview_smp, "arm,realview-smp", &realview_dt_smp_ops); 98