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185 lines
3.9 KiB
185 lines
3.9 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* SMP initialisation and IPI support |
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* Based on arch/arm64/kernel/smp.c |
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* |
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* Copyright (C) 2012 ARM Ltd. |
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* Copyright (C) 2015 Regents of the University of California |
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* Copyright (C) 2017 SiFive |
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*/ |
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#include <linux/arch_topology.h> |
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#include <linux/module.h> |
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#include <linux/init.h> |
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#include <linux/kernel.h> |
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#include <linux/mm.h> |
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#include <linux/sched.h> |
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#include <linux/kernel_stat.h> |
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#include <linux/notifier.h> |
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#include <linux/cpu.h> |
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#include <linux/percpu.h> |
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#include <linux/delay.h> |
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#include <linux/err.h> |
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#include <linux/irq.h> |
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#include <linux/of.h> |
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#include <linux/sched/task_stack.h> |
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#include <linux/sched/mm.h> |
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#include <asm/cpu_ops.h> |
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#include <asm/irq.h> |
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#include <asm/mmu_context.h> |
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#include <asm/numa.h> |
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#include <asm/tlbflush.h> |
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#include <asm/sections.h> |
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#include <asm/sbi.h> |
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#include <asm/smp.h> |
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#include <asm/alternative.h> |
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#include "head.h" |
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static DECLARE_COMPLETION(cpu_running); |
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void __init smp_prepare_boot_cpu(void) |
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{ |
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init_cpu_topology(); |
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#ifdef CONFIG_RISCV_ERRATA_ALTERNATIVE |
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apply_boot_alternatives(); |
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#endif |
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} |
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void __init smp_prepare_cpus(unsigned int max_cpus) |
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{ |
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int cpuid; |
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int ret; |
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unsigned int curr_cpuid; |
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curr_cpuid = smp_processor_id(); |
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numa_store_cpu_info(curr_cpuid); |
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numa_add_cpu(curr_cpuid); |
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/* This covers non-smp usecase mandated by "nosmp" option */ |
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if (max_cpus == 0) |
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return; |
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for_each_possible_cpu(cpuid) { |
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if (cpuid == curr_cpuid) |
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continue; |
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if (cpu_ops[cpuid]->cpu_prepare) { |
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ret = cpu_ops[cpuid]->cpu_prepare(cpuid); |
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if (ret) |
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continue; |
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} |
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set_cpu_present(cpuid, true); |
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numa_store_cpu_info(cpuid); |
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} |
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} |
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void __init setup_smp(void) |
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{ |
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struct device_node *dn; |
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int hart; |
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bool found_boot_cpu = false; |
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int cpuid = 1; |
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cpu_set_ops(0); |
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for_each_of_cpu_node(dn) { |
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hart = riscv_of_processor_hartid(dn); |
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if (hart < 0) |
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continue; |
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if (hart == cpuid_to_hartid_map(0)) { |
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BUG_ON(found_boot_cpu); |
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found_boot_cpu = 1; |
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early_map_cpu_to_node(0, of_node_to_nid(dn)); |
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continue; |
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} |
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if (cpuid >= NR_CPUS) { |
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pr_warn("Invalid cpuid [%d] for hartid [%d]\n", |
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cpuid, hart); |
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break; |
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} |
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cpuid_to_hartid_map(cpuid) = hart; |
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early_map_cpu_to_node(cpuid, of_node_to_nid(dn)); |
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cpuid++; |
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} |
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BUG_ON(!found_boot_cpu); |
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if (cpuid > nr_cpu_ids) |
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pr_warn("Total number of cpus [%d] is greater than nr_cpus option value [%d]\n", |
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cpuid, nr_cpu_ids); |
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for (cpuid = 1; cpuid < nr_cpu_ids; cpuid++) { |
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if (cpuid_to_hartid_map(cpuid) != INVALID_HARTID) { |
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cpu_set_ops(cpuid); |
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set_cpu_possible(cpuid, true); |
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} |
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} |
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} |
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static int start_secondary_cpu(int cpu, struct task_struct *tidle) |
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{ |
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if (cpu_ops[cpu]->cpu_start) |
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return cpu_ops[cpu]->cpu_start(cpu, tidle); |
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return -EOPNOTSUPP; |
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} |
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int __cpu_up(unsigned int cpu, struct task_struct *tidle) |
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{ |
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int ret = 0; |
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tidle->thread_info.cpu = cpu; |
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ret = start_secondary_cpu(cpu, tidle); |
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if (!ret) { |
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wait_for_completion_timeout(&cpu_running, |
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msecs_to_jiffies(1000)); |
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if (!cpu_online(cpu)) { |
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pr_crit("CPU%u: failed to come online\n", cpu); |
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ret = -EIO; |
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} |
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} else { |
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pr_crit("CPU%u: failed to start\n", cpu); |
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} |
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return ret; |
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} |
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void __init smp_cpus_done(unsigned int max_cpus) |
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{ |
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} |
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/* |
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* C entry point for a secondary processor. |
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*/ |
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asmlinkage __visible void smp_callin(void) |
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{ |
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struct mm_struct *mm = &init_mm; |
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unsigned int curr_cpuid = smp_processor_id(); |
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riscv_clear_ipi(); |
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/* All kernel threads share the same mm context. */ |
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mmgrab(mm); |
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current->active_mm = mm; |
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notify_cpu_starting(curr_cpuid); |
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numa_add_cpu(curr_cpuid); |
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update_siblings_masks(curr_cpuid); |
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set_cpu_online(curr_cpuid, 1); |
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/* |
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* Remote TLB flushes are ignored while the CPU is offline, so emit |
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* a local TLB flush right now just in case. |
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*/ |
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local_flush_tlb_all(); |
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complete(&cpu_running); |
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/* |
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* Disable preemption before enabling interrupts, so we don't try to |
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* schedule a CPU that hasn't actually started yet. |
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*/ |
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local_irq_enable(); |
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cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); |
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}
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