1 files changed, 269 insertions, 0 deletions

diff --git a/arch/um/kernel/smp.c b/arch/um/kernel/smp.c
new file mode 100644
index 000000000000..72113b0a96e7
--- /dev/null
+++ b/arch/um/kernel/smp.c
@@ -0,0 +1,269 @@
+/* 
+ * Copyright (C) 2000 - 2003 Jeff Dike (jdike@addtoit.com)
+ * Licensed under the GPL
+ */
+
+#include "linux/config.h"
+#include "linux/percpu.h"
+#include "asm/pgalloc.h"
+#include "asm/tlb.h"
+
+/* For some reason, mmu_gathers are referenced when CONFIG_SMP is off. */
+DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
+
+#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 "user_util.h"
+#include "kern_util.h"
+#include "kern.h"
+#include "irq_user.h"
+#include "os.h"
+
+/* CPU online map, set by smp_boot_cpus */
+cpumask_t cpu_online_map = CPU_MASK_NONE;
+cpumask_t cpu_possible_map = CPU_MASK_NONE;
+
+EXPORT_SYMBOL(cpu_online_map);
+EXPORT_SYMBOL(cpu_possible_map);
+
+/* 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("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);
+
+        activate_ipi(cpu_data[cpu].ipi_pipe[0], 
+                     current->thread.mode.tt.extern_pid);
+ 
+        wmb();
+        if (cpu_test_and_set(cpu, cpu_callin_map)) {
+                printk("huh, CPU#%d already present??\n", cpu);
+                BUG();
+        }
+
+        while (!cpu_isset(cpu, smp_commenced_mask))
+                cpu_relax();
+
+        cpu_set(cpu, cpu_online_map);
+        default_idle();
+        return(0);
+}
+
+static struct task_struct *idle_thread(int cpu)
+{
+        struct task_struct *new_task;
+        unsigned char c;
+
+        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;
+        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);
+}
+
+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)
+                cpu_set(i, cpu_possible_map);
+
+        cpu_clear(me, cpu_online_map);
+        cpu_set(me, cpu_online_map);
+        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);
+
+        activate_ipi(cpu_data[me].ipi_pipe[0],
+                     current->thread.mode.tt.extern_pid);
+
+        for(cpu = 1; cpu < ncpus; cpu++){
+                printk("Booting processor %d...\n", cpu);
+                
+                idle = idle_thread(cpu);
+
+                init_idle(idle, cpu);
+                unhash_process(idle);
+
+                waittime = 200000000;
+                while (waittime-- && !cpu_isset(cpu, cpu_callin_map))
+                        cpu_relax();
+
+                if (cpu_isset(cpu, cpu_callin_map))
+                        printk("done\n");
+                else printk("failed\n");
+        }
+}
+
+void smp_prepare_boot_cpu(void)
+{
+        cpu_set(smp_processor_id(), cpu_online_map);
+}
+
+int __cpu_up(unsigned int cpu)
+{
+        cpu_set(cpu, smp_commenced_mask);
+        while (!cpu_isset(cpu, cpu_online_map))
+                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':
+                        set_tsk_need_resched(current);
+                        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 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 nonatomic, 
+                      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
+
+/*
+ * 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:
+ */