| /* |
| * Copyright (C) 2000 - 2003 Jeff Dike (jdike@addtoit.com) |
| * Licensed under the GPL |
| */ |
| |
| #include "linux/config.h" |
| |
| #ifdef CONFIG_SMP |
| |
| #include "linux/sched.h" |
| #include "linux/threads.h" |
| #include "linux/interrupt.h" |
| #include "asm/smp.h" |
| #include "asm/processor.h" |
| #include "asm/spinlock.h" |
| #include "asm/softirq.h" |
| #include "asm/hardirq.h" |
| #include "asm/tlb.h" |
| #include "user_util.h" |
| #include "kern_util.h" |
| #include "irq_user.h" |
| #include "kern.h" |
| #include "os.h" |
| |
| /* Total count of live CPUs, set by smp_boot_cpus */ |
| int smp_num_cpus = 1; |
| |
| /* The 'big kernel lock' */ |
| spinlock_cacheline_t kernel_flag_cacheline = {SPIN_LOCK_UNLOCKED}; |
| |
| /* 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]; |
| |
| /* CPU online map, set by smp_boot_cpus */ |
| unsigned long cpu_online_map; |
| |
| atomic_t global_bh_count; |
| |
| /* Set when the idlers are all forked */ |
| int smp_threads_ready = 0; |
| |
| /* Not used by UML */ |
| unsigned char global_irq_holder = 0; |
| unsigned volatile long global_irq_lock; |
| |
| /* A statistic, can be a little off */ |
| static int num_reschedules_sent = 0; |
| |
| mmu_gather_t mmu_gathers[NR_CPUS]; |
| |
| void smp_send_reschedule(int cpu) |
| { |
| os_write_file(cpu_data[cpu].ipi_pipe[1], "R", 1); |
| num_reschedules_sent++; |
| } |
| |
| static void show(char * str) |
| { |
| int cpu = smp_processor_id(); |
| |
| printk(KERN_INFO "\n%s, CPU %d:\n", str, cpu); |
| } |
| |
| #define MAXCOUNT 100000000 |
| |
| static inline void wait_on_bh(void) |
| { |
| int count = MAXCOUNT; |
| do { |
| if (!--count) { |
| show("wait_on_bh"); |
| count = ~0; |
| } |
| /* nothing .. wait for the other bh's to go away */ |
| } while (atomic_read(&global_bh_count) != 0); |
| } |
| |
| /* |
| * This is called when we want to synchronize with |
| * bottom half handlers. We need to wait until |
| * no other CPU is executing any bottom half handler. |
| * |
| * Don't wait if we're already running in an interrupt |
| * context or are inside a bh handler. |
| */ |
| void synchronize_bh(void) |
| { |
| if (atomic_read(&global_bh_count) && !in_interrupt()) |
| wait_on_bh(); |
| } |
| |
| void smp_send_stop(void) |
| { |
| int i; |
| |
| printk(KERN_INFO "Stopping all CPUs..."); |
| for(i = 0; i < ncpus; i++){ |
| if(i == current->processor) |
| continue; |
| os_write_file(cpu_data[i].ipi_pipe[1], "S", 1); |
| } |
| printk("done\n"); |
| } |
| |
| |
| static atomic_t smp_commenced = ATOMIC_INIT(0); |
| static volatile unsigned long smp_callin_map = 0; |
| |
| void smp_commence(void) |
| { |
| printk("All CPUs are go!\n"); |
| |
| wmb(); |
| atomic_set(&smp_commenced, 1); |
| } |
| |
| static int idle_proc(void *unused) |
| { |
| int cpu, err; |
| |
| set_current(current); |
| del_from_runqueue(current); |
| unhash_process(current); |
| |
| cpu = current->processor; |
| 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); |
| |
| activate_ipi(cpu_data[cpu].ipi_pipe[0], |
| current->thread.mode.tt.extern_pid); |
| |
| wmb(); |
| if (test_and_set_bit(current->processor, &smp_callin_map)) { |
| printk("huh, CPU#%d already present??\n", current->processor); |
| BUG(); |
| } |
| |
| while (!atomic_read(&smp_commenced)) |
| cpu_relax(); |
| |
| init_idle(); |
| cpu_idle(); |
| return(0); |
| } |
| |
| static int idle_thread(int (*fn)(void *), int cpu) |
| { |
| struct task_struct *new_task; |
| int pid; |
| unsigned char c; |
| |
| current->thread.request.u.thread.proc = fn; |
| current->thread.request.u.thread.arg = NULL; |
| pid = do_fork(CLONE_VM | CLONE_PID, 0, NULL, 0); |
| if(pid < 0) |
| panic("do_fork failed in idle_thread"); |
| new_task = get_task(pid, 1); |
| |
| cpu_tasks[cpu] = ((struct cpu_task) |
| { .pid = new_task->thread.mode.tt.extern_pid, |
| .task = new_task } ); |
| init_tasks[cpu] = new_task; |
| new_task->processor = cpu; |
| new_task->cpus_allowed = 1 << cpu; |
| new_task->cpus_runnable = new_task->cpus_allowed; |
| CHOOSE_MODE(os_write_file(new_task->thread.mode.tt.switch_pipe[1], &c, |
| sizeof(c)), |
| ({ panic("skas mode doesn't support SMP"); })); |
| return(new_task->thread.mode.tt.extern_pid); |
| } |
| |
| void smp_boot_cpus(void) |
| { |
| int err; |
| |
| set_bit(0, &cpu_online_map); |
| set_bit(0, &smp_callin_map); |
| |
| err = os_pipe(cpu_data[0].ipi_pipe, 1, 1); |
| if(err < 0) |
| panic("CPU#0 failed to create IPI pipe, err = %d", -err); |
| |
| activate_ipi(cpu_data[0].ipi_pipe[0], |
| current->thread.mode.tt.extern_pid); |
| |
| if(ncpus < 1){ |
| printk(KERN_INFO "ncpus set to 1\n"); |
| ncpus = 1; |
| } |
| else if(ncpus > NR_CPUS){ |
| printk(KERN_INFO |
| "ncpus can't be greater than NR_CPUS, set to %d\n", |
| NR_CPUS); |
| ncpus = NR_CPUS; |
| } |
| |
| if(ncpus > 1){ |
| int i, pid; |
| |
| printk(KERN_INFO "Starting up other processors:\n"); |
| for(i=1;i<ncpus;i++){ |
| int waittime; |
| |
| /* Do this early, for hard_smp_processor_id() */ |
| cpu_tasks[i].pid = -1; |
| set_bit(i, &cpu_online_map); |
| smp_num_cpus++; |
| |
| pid = idle_thread(idle_proc, i); |
| printk(KERN_INFO "\t#%d - idle thread pid = %d.. ", |
| i, pid); |
| |
| waittime = 200000000; |
| while (waittime-- && !test_bit(i, &smp_callin_map)) |
| cpu_relax(); |
| |
| if (test_bit(i, &smp_callin_map)) |
| printk("online\n"); |
| else { |
| printk("failed\n"); |
| clear_bit(i, &cpu_online_map); |
| } |
| } |
| } |
| } |
| |
| 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': |
| current->need_resched = 1; |
| break; |
| |
| case 'S': |
| printk("CPU#%d stopping\n", cpu); |
| while(1) |
| pause(); |
| break; |
| |
| default: |
| printk("CPU#%d received unknown IPI [%c]!\n", cpu, c); |
| break; |
| } |
| } |
| } |
| |
| int hard_smp_processor_id(void) |
| { |
| return(pid_to_processor_id(os_getpid())); |
| } |
| |
| static spinlock_t call_lock = SPIN_LOCK_UNLOCKED; |
| 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 nonatomic, |
| int wait) |
| { |
| int cpus = smp_num_cpus - 1; |
| int i; |
| |
| if (!cpus) |
| return 0; |
| |
| spin_lock_bh(&call_lock); |
| atomic_set(&scf_started, 0); |
| atomic_set(&scf_finished, 0); |
| func = _func; |
| info = _info; |
| |
| for (i=0;i<NR_CPUS;i++) |
| if (i != current->processor && test_bit(i, &cpu_online_map)) |
| 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 |
| |
| /* |
| * Overrides for Emacs so that we follow Linus's tabbing style. |
| * Emacs will notice this stuff at the end of the file and automatically |
| * adjust the settings for this buffer only. This must remain at the end |
| * of the file. |
| * --------------------------------------------------------------------------- |
| * Local variables: |
| * c-file-style: "linux" |
| * End: |
| */ |