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 static int dualcores_found; 24 25 /* 26 * store_cpu_topology is called at boot when only one cpu is running 27 * and with the mutex cpu_hotplug.lock locked, when several cpus have booted, 28 * which prevents simultaneous write access to cpu_topology array 29 */ 30 void store_cpu_topology(unsigned int cpuid) 31 { 32 struct cpu_topology *cpuid_topo = &cpu_topology[cpuid]; 33 struct cpuinfo_parisc *p; 34 int max_socket = -1; 35 unsigned long cpu; 36 37 /* If the cpu topology has been already set, just return */ 38 if (cpuid_topo->core_id != -1) 39 return; 40 41 #ifdef CONFIG_HOTPLUG_CPU 42 per_cpu(cpu_devices, cpuid).hotpluggable = 1; 43 #endif 44 if (register_cpu(&per_cpu(cpu_devices, cpuid), cpuid)) 45 pr_warn("Failed to register CPU%d device", cpuid); 46 47 /* create cpu topology mapping */ 48 cpuid_topo->thread_id = -1; 49 cpuid_topo->core_id = 0; 50 51 p = &per_cpu(cpu_data, cpuid); 52 for_each_online_cpu(cpu) { 53 const struct cpuinfo_parisc *cpuinfo = &per_cpu(cpu_data, cpu); 54 55 if (cpu == cpuid) /* ignore current cpu */ 56 continue; 57 58 if (cpuinfo->cpu_loc == p->cpu_loc) { 59 cpuid_topo->core_id = cpu_topology[cpu].core_id; 60 if (p->cpu_loc) { 61 cpuid_topo->core_id++; 62 cpuid_topo->package_id = cpu_topology[cpu].package_id; 63 dualcores_found = 1; 64 continue; 65 } 66 } 67 68 if (cpuid_topo->package_id == -1) 69 max_socket = max(max_socket, cpu_topology[cpu].package_id); 70 } 71 72 if (cpuid_topo->package_id == -1) 73 cpuid_topo->package_id = max_socket + 1; 74 75 update_siblings_masks(cpuid); 76 77 pr_info("CPU%u: cpu core %d of socket %d\n", 78 cpuid, 79 cpu_topology[cpuid].core_id, 80 cpu_topology[cpuid].package_id); 81 } 82 83 static struct sched_domain_topology_level parisc_mc_topology[] = { 84 #ifdef CONFIG_SCHED_MC 85 { cpu_coregroup_mask, cpu_core_flags, SD_INIT_NAME(MC) }, 86 #endif 87 88 { cpu_cpu_mask, SD_INIT_NAME(DIE) }, 89 { NULL, }, 90 }; 91 92 /* 93 * init_cpu_topology is called at boot when only one cpu is running 94 * which prevent simultaneous write access to cpu_topology array 95 */ 96 void __init init_cpu_topology(void) 97 { 98 /* Set scheduler topology descriptor */ 99 if (dualcores_found) 100 set_sched_topology(parisc_mc_topology); 101 } 102