cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

topology.c (2252B)

      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
     21static 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 */
     28void 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 */
     84void __init init_cpu_topology(void)
     85{
     86	reset_cpu_topology();
     87}