| /* |
| * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) |
| * Licensed under the GPL |
| */ |
| |
| #include "linux/percpu.h" |
| #include "asm/pgalloc.h" |
| #include "asm/tlb.h" |
| |
| #ifdef CONFIG_SMP |
| |
| #include "linux/sched.h" |
| #include "linux/module.h" |
| #include "linux/threads.h" |
| #include "linux/interrupt.h" |
| #include "linux/err.h" |
| #include "linux/hardirq.h" |
| #include "asm/smp.h" |
| #include "asm/processor.h" |
| #include "asm/spinlock.h" |
| #include "kern.h" |
| #include "irq_user.h" |
| #include "os.h" |
| |
| /* Per CPU bogomips and other parameters |
| * The only piece used here is the ipi pipe, which is set before SMP is |
| * started and never changed. |
| */ |
| struct cpuinfo_um cpu_data[NR_CPUS]; |
| |
| /* A statistic, can be a little off */ |
| int num_reschedules_sent = 0; |
| |
| /* Not changed after boot */ |
| struct task_struct *idle_threads[NR_CPUS]; |
| |
| void smp_send_reschedule(int cpu) |
| { |
| os_write_file(cpu_data[cpu].ipi_pipe[1], "R", 1); |
| num_reschedules_sent++; |
| } |
| |
| void smp_send_stop(void) |
| { |
| int i; |
| |
| printk(KERN_INFO "Stopping all CPUs..."); |
| for (i = 0; i < num_online_cpus(); i++) { |
| if (i == current_thread->cpu) |
| continue; |
| os_write_file(cpu_data[i].ipi_pipe[1], "S", 1); |
| } |
| printk(KERN_CONT "done\n"); |
| } |
| |
| static cpumask_t smp_commenced_mask = CPU_MASK_NONE; |
| static cpumask_t cpu_callin_map = CPU_MASK_NONE; |
| |
| static int idle_proc(void *cpup) |
| { |
| int cpu = (int) cpup, err; |
| |
| err = os_pipe(cpu_data[cpu].ipi_pipe, 1, 1); |
| if (err < 0) |
| panic("CPU#%d failed to create IPI pipe, err = %d", cpu, -err); |
| |
| os_set_fd_async(cpu_data[cpu].ipi_pipe[0]); |
| |
| wmb(); |
| if (cpu_test_and_set(cpu, cpu_callin_map)) { |
| printk(KERN_ERR "huh, CPU#%d already present??\n", cpu); |
| BUG(); |
| } |
| |
| while (!cpu_isset(cpu, smp_commenced_mask)) |
| cpu_relax(); |
| |
| notify_cpu_starting(cpu); |
| set_cpu_online(cpu, true); |
| default_idle(); |
| return 0; |
| } |
| |
| static struct task_struct *idle_thread(int cpu) |
| { |
| struct task_struct *new_task; |
| |
| current->thread.request.u.thread.proc = idle_proc; |
| current->thread.request.u.thread.arg = (void *) cpu; |
| new_task = fork_idle(cpu); |
| if (IS_ERR(new_task)) |
| panic("copy_process failed in idle_thread, error = %ld", |
| PTR_ERR(new_task)); |
| |
| cpu_tasks[cpu] = ((struct cpu_task) |
| { .pid = new_task->thread.mode.tt.extern_pid, |
| .task = new_task } ); |
| idle_threads[cpu] = new_task; |
| panic("skas mode doesn't support SMP"); |
| return new_task; |
| } |
| |
| void smp_prepare_cpus(unsigned int maxcpus) |
| { |
| struct task_struct *idle; |
| unsigned long waittime; |
| int err, cpu, me = smp_processor_id(); |
| int i; |
| |
| for (i = 0; i < ncpus; ++i) |
| set_cpu_possible(i, true); |
| |
| set_cpu_online(me, true); |
| cpu_set(me, cpu_callin_map); |
| |
| err = os_pipe(cpu_data[me].ipi_pipe, 1, 1); |
| if (err < 0) |
| panic("CPU#0 failed to create IPI pipe, errno = %d", -err); |
| |
| os_set_fd_async(cpu_data[me].ipi_pipe[0]); |
| |
| for (cpu = 1; cpu < ncpus; cpu++) { |
| printk(KERN_INFO "Booting processor %d...\n", cpu); |
| |
| idle = idle_thread(cpu); |
| |
| init_idle(idle, cpu); |
| |
| waittime = 200000000; |
| while (waittime-- && !cpu_isset(cpu, cpu_callin_map)) |
| cpu_relax(); |
| |
| printk(KERN_INFO "%s\n", |
| cpu_isset(cpu, cpu_calling_map) ? "done" : "failed"); |
| } |
| } |
| |
| void smp_prepare_boot_cpu(void) |
| { |
| set_cpu_online(smp_processor_id(), true); |
| } |
| |
| int __cpu_up(unsigned int cpu) |
| { |
| cpu_set(cpu, smp_commenced_mask); |
| while (!cpu_online(cpu)) |
| mb(); |
| return 0; |
| } |
| |
| int setup_profiling_timer(unsigned int multiplier) |
| { |
| printk(KERN_INFO "setup_profiling_timer\n"); |
| return 0; |
| } |
| |
| void smp_call_function_slave(int cpu); |
| |
| void IPI_handler(int cpu) |
| { |
| unsigned char c; |
| int fd; |
| |
| fd = cpu_data[cpu].ipi_pipe[0]; |
| while (os_read_file(fd, &c, 1) == 1) { |
| switch (c) { |
| case 'C': |
| smp_call_function_slave(cpu); |
| break; |
| |
| case 'R': |
| scheduler_ipi(); |
| break; |
| |
| case 'S': |
| printk(KERN_INFO "CPU#%d stopping\n", cpu); |
| while (1) |
| pause(); |
| break; |
| |
| default: |
| printk(KERN_ERR "CPU#%d received unknown IPI [%c]!\n", |
| cpu, c); |
| break; |
| } |
| } |
| } |
| |
| int hard_smp_processor_id(void) |
| { |
| return pid_to_processor_id(os_getpid()); |
| } |
| |
| static DEFINE_SPINLOCK(call_lock); |
| static atomic_t scf_started; |
| static atomic_t scf_finished; |
| static void (*func)(void *info); |
| static void *info; |
| |
| void smp_call_function_slave(int cpu) |
| { |
| atomic_inc(&scf_started); |
| (*func)(info); |
| atomic_inc(&scf_finished); |
| } |
| |
| int smp_call_function(void (*_func)(void *info), void *_info, int wait) |
| { |
| int cpus = num_online_cpus() - 1; |
| int i; |
| |
| if (!cpus) |
| return 0; |
| |
| /* Can deadlock when called with interrupts disabled */ |
| WARN_ON(irqs_disabled()); |
| |
| spin_lock_bh(&call_lock); |
| atomic_set(&scf_started, 0); |
| atomic_set(&scf_finished, 0); |
| func = _func; |
| info = _info; |
| |
| for_each_online_cpu(i) |
| os_write_file(cpu_data[i].ipi_pipe[1], "C", 1); |
| |
| while (atomic_read(&scf_started) != cpus) |
| barrier(); |
| |
| if (wait) |
| while (atomic_read(&scf_finished) != cpus) |
| barrier(); |
| |
| spin_unlock_bh(&call_lock); |
| return 0; |
| } |
| |
| #endif |