Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
This commit is contained in:
Linus Torvalds
269
arch/um/kernel/smp.c
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269
arch/um/kernel/smp.c
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/*
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* Copyright (C) 2000 - 2003 Jeff Dike (jdike@addtoit.com)
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* Licensed under the GPL
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*/
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#include "linux/config.h"
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#include "linux/percpu.h"
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#include "asm/pgalloc.h"
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#include "asm/tlb.h"
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/* For some reason, mmu_gathers are referenced when CONFIG_SMP is off. */
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DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
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#ifdef CONFIG_SMP
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#include "linux/sched.h"
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#include "linux/module.h"
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#include "linux/threads.h"
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#include "linux/interrupt.h"
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#include "linux/err.h"
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#include "linux/hardirq.h"
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#include "asm/smp.h"
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#include "asm/processor.h"
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#include "asm/spinlock.h"
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#include "user_util.h"
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#include "kern_util.h"
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#include "kern.h"
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#include "irq_user.h"
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#include "os.h"
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/* CPU online map, set by smp_boot_cpus */
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cpumask_t cpu_online_map = CPU_MASK_NONE;
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cpumask_t cpu_possible_map = CPU_MASK_NONE;
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EXPORT_SYMBOL(cpu_online_map);
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EXPORT_SYMBOL(cpu_possible_map);
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/* Per CPU bogomips and other parameters
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* The only piece used here is the ipi pipe, which is set before SMP is
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* started and never changed.
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*/
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struct cpuinfo_um cpu_data[NR_CPUS];
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/* A statistic, can be a little off */
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int num_reschedules_sent = 0;
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/* Not changed after boot */
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struct task_struct *idle_threads[NR_CPUS];
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void smp_send_reschedule(int cpu)
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{
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os_write_file(cpu_data[cpu].ipi_pipe[1], "R", 1);
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num_reschedules_sent++;
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}
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void smp_send_stop(void)
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{
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int i;
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printk(KERN_INFO "Stopping all CPUs...");
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for(i = 0; i < num_online_cpus(); i++){
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if(i == current_thread->cpu)
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continue;
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os_write_file(cpu_data[i].ipi_pipe[1], "S", 1);
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}
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printk("done\n");
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}
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static cpumask_t smp_commenced_mask = CPU_MASK_NONE;
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static cpumask_t cpu_callin_map = CPU_MASK_NONE;
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static int idle_proc(void *cpup)
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{
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int cpu = (int) cpup, err;
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err = os_pipe(cpu_data[cpu].ipi_pipe, 1, 1);
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if(err < 0)
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panic("CPU#%d failed to create IPI pipe, err = %d", cpu, -err);
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activate_ipi(cpu_data[cpu].ipi_pipe[0],
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current->thread.mode.tt.extern_pid);
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wmb();
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if (cpu_test_and_set(cpu, cpu_callin_map)) {
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printk("huh, CPU#%d already present??\n", cpu);
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BUG();
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}
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while (!cpu_isset(cpu, smp_commenced_mask))
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cpu_relax();
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cpu_set(cpu, cpu_online_map);
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default_idle();
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return(0);
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}
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static struct task_struct *idle_thread(int cpu)
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{
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struct task_struct *new_task;
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unsigned char c;
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current->thread.request.u.thread.proc = idle_proc;
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current->thread.request.u.thread.arg = (void *) cpu;
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new_task = fork_idle(cpu);
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if(IS_ERR(new_task))
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panic("copy_process failed in idle_thread, error = %ld",
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PTR_ERR(new_task));
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cpu_tasks[cpu] = ((struct cpu_task)
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{ .pid = new_task->thread.mode.tt.extern_pid,
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.task = new_task } );
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idle_threads[cpu] = new_task;
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CHOOSE_MODE(os_write_file(new_task->thread.mode.tt.switch_pipe[1], &c,
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sizeof(c)),
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({ panic("skas mode doesn't support SMP"); }));
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return(new_task);
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}
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void smp_prepare_cpus(unsigned int maxcpus)
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{
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struct task_struct *idle;
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unsigned long waittime;
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int err, cpu, me = smp_processor_id();
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int i;
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for (i = 0; i < ncpus; ++i)
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cpu_set(i, cpu_possible_map);
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cpu_clear(me, cpu_online_map);
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cpu_set(me, cpu_online_map);
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cpu_set(me, cpu_callin_map);
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err = os_pipe(cpu_data[me].ipi_pipe, 1, 1);
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if(err < 0)
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panic("CPU#0 failed to create IPI pipe, errno = %d", -err);
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activate_ipi(cpu_data[me].ipi_pipe[0],
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current->thread.mode.tt.extern_pid);
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for(cpu = 1; cpu < ncpus; cpu++){
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printk("Booting processor %d...\n", cpu);
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idle = idle_thread(cpu);
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init_idle(idle, cpu);
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unhash_process(idle);
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waittime = 200000000;
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while (waittime-- && !cpu_isset(cpu, cpu_callin_map))
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cpu_relax();
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if (cpu_isset(cpu, cpu_callin_map))
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printk("done\n");
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else printk("failed\n");
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}
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}
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void smp_prepare_boot_cpu(void)
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{
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cpu_set(smp_processor_id(), cpu_online_map);
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}
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int __cpu_up(unsigned int cpu)
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{
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cpu_set(cpu, smp_commenced_mask);
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while (!cpu_isset(cpu, cpu_online_map))
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mb();
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return(0);
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}
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int setup_profiling_timer(unsigned int multiplier)
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{
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printk(KERN_INFO "setup_profiling_timer\n");
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return(0);
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}
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void smp_call_function_slave(int cpu);
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void IPI_handler(int cpu)
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{
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unsigned char c;
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int fd;
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fd = cpu_data[cpu].ipi_pipe[0];
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while (os_read_file(fd, &c, 1) == 1) {
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switch (c) {
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case 'C':
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smp_call_function_slave(cpu);
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break;
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case 'R':
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set_tsk_need_resched(current);
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break;
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case 'S':
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printk("CPU#%d stopping\n", cpu);
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while(1)
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pause();
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break;
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default:
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printk("CPU#%d received unknown IPI [%c]!\n", cpu, c);
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break;
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}
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}
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}
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int hard_smp_processor_id(void)
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{
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return(pid_to_processor_id(os_getpid()));
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}
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static DEFINE_SPINLOCK(call_lock);
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static atomic_t scf_started;
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static atomic_t scf_finished;
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static void (*func)(void *info);
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static void *info;
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void smp_call_function_slave(int cpu)
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{
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atomic_inc(&scf_started);
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(*func)(info);
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atomic_inc(&scf_finished);
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}
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int smp_call_function(void (*_func)(void *info), void *_info, int nonatomic,
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int wait)
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{
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int cpus = num_online_cpus() - 1;
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int i;
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if (!cpus)
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return 0;
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/* Can deadlock when called with interrupts disabled */
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WARN_ON(irqs_disabled());
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spin_lock_bh(&call_lock);
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atomic_set(&scf_started, 0);
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atomic_set(&scf_finished, 0);
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func = _func;
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info = _info;
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for_each_online_cpu(i)
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os_write_file(cpu_data[i].ipi_pipe[1], "C", 1);
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while (atomic_read(&scf_started) != cpus)
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barrier();
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if (wait)
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while (atomic_read(&scf_finished) != cpus)
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barrier();
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spin_unlock_bh(&call_lock);
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return 0;
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}
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#endif
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/*
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* Overrides for Emacs so that we follow Linus's tabbing style.
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* Emacs will notice this stuff at the end of the file and automatically
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* adjust the settings for this buffer only. This must remain at the end
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* of the file.
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* ---------------------------------------------------------------------------
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* Local variables:
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* c-file-style: "linux"
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* End:
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*/
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