mirror of https://github.com/torvalds/linux.git
149 lines
2.7 KiB
C
149 lines
2.7 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2025 Ant Group
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* Author: Tiwei Bie <tiwei.btw@antgroup.com>
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*/
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#include <errno.h>
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#include <pthread.h>
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#include <signal.h>
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#include <kern_util.h>
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#include <um_malloc.h>
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#include <init.h>
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#include <os.h>
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#include <smp.h>
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#include "internal.h"
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struct cpu_thread_data {
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int cpu;
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sigset_t sigset;
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};
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static __thread int __curr_cpu;
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int uml_curr_cpu(void)
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{
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return __curr_cpu;
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}
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static pthread_t cpu_threads[CONFIG_NR_CPUS];
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static void *cpu_thread(void *arg)
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{
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struct cpu_thread_data *data = arg;
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__curr_cpu = data->cpu;
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uml_start_secondary(data);
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return NULL;
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}
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int os_start_cpu_thread(int cpu)
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{
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struct cpu_thread_data *data;
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sigset_t sigset, oset;
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int err;
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data = uml_kmalloc(sizeof(*data), UM_GFP_ATOMIC);
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if (!data)
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return -ENOMEM;
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sigfillset(&sigset);
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if (sigprocmask(SIG_SETMASK, &sigset, &oset) < 0) {
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err = errno;
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goto err;
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}
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data->cpu = cpu;
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data->sigset = oset;
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err = pthread_create(&cpu_threads[cpu], NULL, cpu_thread, data);
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if (sigprocmask(SIG_SETMASK, &oset, NULL) < 0)
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panic("Failed to restore the signal mask, errno = %d", errno);
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if (err != 0)
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goto err;
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return 0;
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err:
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kfree(data);
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return -err;
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}
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void os_start_secondary(void *arg, jmp_buf *switch_buf)
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{
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struct cpu_thread_data *data = arg;
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sigaddset(&data->sigset, IPI_SIGNAL);
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sigaddset(&data->sigset, SIGIO);
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if (sigprocmask(SIG_SETMASK, &data->sigset, NULL) < 0)
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panic("Failed to restore the signal mask, errno = %d", errno);
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kfree(data);
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longjmp(*switch_buf, 1);
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/* unreachable */
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printk(UM_KERN_ERR "impossible long jump!");
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fatal_sigsegv();
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}
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int os_send_ipi(int cpu, int vector)
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{
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union sigval value = { .sival_int = vector };
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return pthread_sigqueue(cpu_threads[cpu], IPI_SIGNAL, value);
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}
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static void __local_ipi_set(int enable)
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{
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sigset_t sigset;
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sigemptyset(&sigset);
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sigaddset(&sigset, IPI_SIGNAL);
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if (sigprocmask(enable ? SIG_UNBLOCK : SIG_BLOCK, &sigset, NULL) < 0)
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panic("%s: sigprocmask failed, errno = %d", __func__, errno);
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}
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void os_local_ipi_enable(void)
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{
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__local_ipi_set(1);
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}
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void os_local_ipi_disable(void)
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{
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__local_ipi_set(0);
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}
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static void ipi_sig_handler(int sig, siginfo_t *si, void *uc)
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{
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int save_errno = errno;
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signals_enabled = 0;
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um_trace_signals_off();
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uml_ipi_handler(si->si_value.sival_int);
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um_trace_signals_on();
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signals_enabled = 1;
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errno = save_errno;
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}
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void __init os_init_smp(void)
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{
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struct sigaction action = {
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.sa_sigaction = ipi_sig_handler,
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.sa_flags = SA_SIGINFO | SA_ONSTACK | SA_RESTART,
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};
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sigfillset(&action.sa_mask);
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if (sigaction(IPI_SIGNAL, &action, NULL) < 0)
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panic("%s: sigaction failed, errno = %d", __func__, errno);
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cpu_threads[0] = pthread_self();
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}
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