1 /* 2 * arch/parisc/kernel/topology.c 3 * 4 * Copyright (C) 2017 Helge Deller <deller@gmx.de> 5 * 6 * based on arch/arm/kernel/topology.c 7 * 8 * This file is subject to the terms and conditions of the GNU General Public 9 * License. See the file "COPYING" in the main directory of this archive 10 * for more details. 11 */ 12 13 #include <linux/percpu.h> 14 #include <linux/sched.h> 15 #include <linux/sched/topology.h> 16 #include <linux/cpu.h> 17 18 #include <asm/topology.h> 19 #include <asm/sections.h> 20 21 static DEFINE_PER_CPU(struct cpu, cpu_devices); 22 23 /* 24 * store_cpu_topology is called at boot when only one cpu is running 25 * and with the mutex cpu_hotplug.lock locked, when several cpus have booted, 26 * which prevents simultaneous write access to cpu_topology array 27 */ 28 void store_cpu_topology(unsigned int cpuid) 29 { 30 struct cpu_topology *cpuid_topo = &cpu_topology[cpuid]; 31 struct cpuinfo_parisc *p; 32 int max_socket = -1; 33 unsigned long cpu; 34 35 /* If the cpu topology has been already set, just return */ 36 if (cpuid_topo->core_id != -1) 37 return; 38 39 #ifdef CONFIG_HOTPLUG_CPU 40 per_cpu(cpu_devices, cpuid).hotpluggable = 1; 41 #endif 42 if (register_cpu(&per_cpu(cpu_devices, cpuid), cpuid)) 43 pr_warn("Failed to register CPU%d device", cpuid); 44 45 /* create cpu topology mapping */ 46 cpuid_topo->thread_id = -1; 47 cpuid_topo->core_id = 0; 48 49 p = &per_cpu(cpu_data, cpuid); 50 for_each_online_cpu(cpu) { 51 const struct cpuinfo_parisc *cpuinfo = &per_cpu(cpu_data, cpu); 52 53 if (cpu == cpuid) /* ignore current cpu */ 54 continue; 55 56 if (cpuinfo->cpu_loc == p->cpu_loc) { 57 cpuid_topo->core_id = cpu_topology[cpu].core_id; 58 if (p->cpu_loc) { 59 cpuid_topo->core_id++; 60 cpuid_topo->package_id = cpu_topology[cpu].package_id; 61 continue; 62 } 63 } 64 65 if (cpuid_topo->package_id == -1) 66 max_socket = max(max_socket, cpu_topology[cpu].package_id); 67 } 68 69 if (cpuid_topo->package_id == -1) 70 cpuid_topo->package_id = max_socket + 1; 71 72 update_siblings_masks(cpuid); 73 74 pr_info("CPU%u: cpu core %d of socket %d\n", 75 cpuid, 76 cpu_topology[cpuid].core_id, 77 cpu_topology[cpuid].package_id); 78 } 79 80 /* 81 * init_cpu_topology is called at boot when only one cpu is running 82 * which prevent simultaneous write access to cpu_topology array 83 */ 84 void __init init_cpu_topology(void) 85 { 86 reset_cpu_topology(); 87 } 88