xnu-344.49.tar.gz

[apple/xnu.git] / osfmk / kern / machine.c

/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*
 * @OSF_COPYRIGHT@
 */
/* 
 * Mach Operating System
 * Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University
 * All Rights Reserved.
 * 
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 * 
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 * 
 * Carnegie Mellon requests users of this software to return to
 * 
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 * 
 * any improvements or extensions that they make and grant Carnegie Mellon
 * the rights to redistribute these changes.
 */
/*
 */
/*
 *      File:   kern/machine.c
 *      Author: Avadis Tevanian, Jr.
 *      Date:   1987
 *
 *      Support for machine independent machine abstraction.
 */

#include <cpus.h>

#include <string.h>
#include <mach/boolean.h>
#include <mach/kern_return.h>
#include <mach/mach_types.h>
#include <mach/machine.h>
#include <mach/host_info.h>
#include <mach/host_reboot.h>
#include <kern/counters.h>
#include <kern/cpu_data.h>
#include <kern/ipc_host.h>
#include <kern/host.h>
#include <kern/lock.h>
#include <kern/machine.h>
#include <kern/processor.h>
#include <kern/queue.h>
#include <kern/sched.h>
#include <kern/task.h>
#include <kern/thread.h>
#include <kern/thread_swap.h>
#include <kern/misc_protos.h>

#include <kern/mk_sp.h>

/*
 *      Exported variables:
 */

struct machine_info     machine_info;
struct machine_slot     machine_slot[NCPUS];

static queue_head_t                     processor_action_queue;
static boolean_t                        processor_action_active;
static thread_call_t            processor_action_call;
static thread_call_data_t       processor_action_call_data;
decl_simple_lock_data(static,processor_action_lock)

thread_t                machine_wake_thread;

/* Forwards */
processor_set_t processor_request_action(
                                        processor_t                     processor,
                                        processor_set_t         new_pset);

void                    processor_doaction(
                                        processor_t                     processor);

void                    processor_doshutdown(
                                        processor_t                     processor);

/*
 *      cpu_up:
 *
 * Flag specified cpu as up and running.  Called when a processor comes
 * online.
 */
void
cpu_up(
        int             cpu)
{
        processor_t                             processor = cpu_to_processor(cpu);
        processor_set_t                 pset = &default_pset;
        struct machine_slot             *ms;
        spl_t                                   s;
        
        /*
         * Just twiddle our thumbs; we've got nothing better to do
         * yet, anyway.
         */
        while (!simple_lock_try(&pset->processors_lock))
                continue;

        s = splsched();
        processor_lock(processor);
        init_ast_check(processor);
        ms = &machine_slot[cpu];
        ms->running = TRUE;
        machine_info.avail_cpus++;
        pset_add_processor(pset, processor);
        simple_lock(&pset->sched_lock);
        enqueue_tail(&pset->active_queue, (queue_entry_t)processor);
        processor->state = PROCESSOR_RUNNING;
        simple_unlock(&pset->sched_lock);
        processor_unlock(processor);
        splx(s);

        simple_unlock(&pset->processors_lock);
}

/*
 *      cpu_down:
 *
 *      Flag specified cpu as down.  Called when a processor is about to
 *      go offline.
 */
void
cpu_down(
        int             cpu)
{
        processor_t                             processor;
        struct machine_slot             *ms;
        spl_t                                   s;

        processor = cpu_to_processor(cpu);

        s = splsched();
        processor_lock(processor);
        ms = &machine_slot[cpu];
        ms->running = FALSE;
        machine_info.avail_cpus--;
        /*
         *      processor has already been removed from pset.
         */
        processor->processor_set_next = PROCESSOR_SET_NULL;
        processor->state = PROCESSOR_OFF_LINE;
        processor_unlock(processor);
        splx(s);
}

kern_return_t
host_reboot(
        host_priv_t                     host_priv,
        int                             options)
{
        if (host_priv == HOST_PRIV_NULL)
                return (KERN_INVALID_HOST);

        assert(host_priv == &realhost);

        if (options & HOST_REBOOT_DEBUGGER) {
                Debugger("Debugger");
        }
        else
                halt_all_cpus(!(options & HOST_REBOOT_HALT));

        return (KERN_SUCCESS);
}

/*
 * processor_request_action: 
 *
 * Common internals of processor_assign and processor_shutdown.  
 * If new_pset is null, this is a shutdown, else it's an assign 
 * and caller must donate a reference.  
 * For assign operations, it returns an old pset that must be deallocated 
 * if it's not NULL.  
 * For shutdown operations, it always returns PROCESSOR_SET_NULL.
 */
processor_set_t
processor_request_action(
        processor_t                     processor,
        processor_set_t         new_pset)
{
        processor_set_t         pset, old_pset;

        /*
         * Processor must be in a processor set.  Must lock its idle lock to
         * get at processor state.
         */
        pset = processor->processor_set;
        simple_lock(&pset->sched_lock);

        /*
         * If the processor is dispatching, let it finish - it will set its
         * state to running very soon.
         */
        while (*(volatile int *)&processor->state == PROCESSOR_DISPATCHING) {
                simple_unlock(&pset->sched_lock);

                simple_lock(&pset->sched_lock);
        }

        assert( processor->state == PROCESSOR_IDLE              ||
                        processor->state == PROCESSOR_RUNNING   ||
                        processor->state == PROCESSOR_ASSIGN    );

        /*
         * Now lock the action queue and do the dirty work.
         */
        simple_lock(&processor_action_lock);

        if (processor->state == PROCESSOR_IDLE) {
                remqueue(&pset->idle_queue, (queue_entry_t)processor);
                pset->idle_count--;
        }
        else
        if (processor->state == PROCESSOR_RUNNING)
                remqueue(&pset->active_queue, (queue_entry_t)processor);

        if (processor->state != PROCESSOR_ASSIGN)
                enqueue_tail(&processor_action_queue, (queue_entry_t)processor);

        /*
         * And ask the action_thread to do the work.
         */
        if (new_pset != PROCESSOR_SET_NULL) {
                processor->state = PROCESSOR_ASSIGN;
                old_pset = processor->processor_set_next;
                processor->processor_set_next = new_pset;
        }
        else {
                processor->state = PROCESSOR_SHUTDOWN;
                old_pset = PROCESSOR_SET_NULL;
        }

        simple_unlock(&pset->sched_lock);

        if (processor_action_active) {
                simple_unlock(&processor_action_lock);

                return (old_pset);
        }

        processor_action_active = TRUE;
        simple_unlock(&processor_action_lock);

        processor_unlock(processor);

        thread_call_enter(processor_action_call);
        processor_lock(processor);

        return (old_pset);
}

kern_return_t
processor_assign(
        processor_t                     processor,
        processor_set_t         new_pset,
        boolean_t                       wait)
{
#ifdef  lint
        processor++; new_pset++; wait++;
#endif  /* lint */
        return (KERN_FAILURE);
}

/*
 *      processor_shutdown() queues a processor up for shutdown.
 *      Any assignment in progress is overriden.
 */
kern_return_t
processor_shutdown(
        processor_t             processor)
{
        spl_t s;

        s = splsched();
        processor_lock(processor);
        if (    processor->state == PROCESSOR_OFF_LINE  ||
                        processor->state == PROCESSOR_SHUTDOWN  ) {
                /*
                 * Already shutdown or being shutdown -- nothing to do.
                 */
                processor_unlock(processor);
                splx(s);

                return (KERN_SUCCESS);
        }

        processor_request_action(processor, PROCESSOR_SET_NULL);

        assert_wait((event_t)processor, THREAD_UNINT);

    processor_unlock(processor);
        splx(s);

        thread_block(THREAD_CONTINUE_NULL);

        return (KERN_SUCCESS);
}

/*
 *      processor_action() shuts down processors or changes their assignment.
 */
static void
_processor_action(
        thread_call_param_t             p0,
        thread_call_param_t             p1)
{
        register processor_t    processor;
        spl_t s;

        s = splsched();
        simple_lock(&processor_action_lock);

        while (!queue_empty(&processor_action_queue)) {
                processor = (processor_t)dequeue_head(&processor_action_queue);
                simple_unlock(&processor_action_lock);
                splx(s);

                processor_doaction(processor);

                s = splsched();
                simple_lock(&processor_action_lock);
        }

        processor_action_active = FALSE;
        simple_unlock(&processor_action_lock);
        splx(s);
}

void
processor_action(void)
{
        queue_init(&processor_action_queue);
        simple_lock_init(&processor_action_lock, ETAP_THREAD_ACTION); 
        processor_action_active = FALSE;

        thread_call_setup(&processor_action_call_data, _processor_action, NULL);
        processor_action_call = &processor_action_call_data;
}

/*
 *      processor_doaction actually does the shutdown.  The trick here
 *      is to schedule ourselves onto a cpu and then save our
 *      context back into the runqs before taking out the cpu.
 */
void
processor_doaction(
        processor_t                                     processor)
{
        thread_t                        self = current_thread();
        processor_set_t         pset;
        thread_t                        old_thread;
        spl_t                           s;

        /*
         *      Get onto the processor to shutdown
         */
        thread_bind(self, processor);
        thread_block(THREAD_CONTINUE_NULL);

        pset = processor->processor_set;
        simple_lock(&pset->processors_lock);

        if (pset->processor_count == 1) {
                thread_t                thread;
                extern void             start_cpu_thread(void);

                simple_unlock(&pset->processors_lock);

                /*
                 * Create the thread, and point it at the routine.
                 */
                thread = kernel_thread_with_priority(
                                                                        kernel_task, MAXPRI_KERNEL,
                                                                                start_cpu_thread, TRUE, FALSE);

                disable_preemption();

                s = splsched();
                thread_lock(thread);
                machine_wake_thread = thread;
                thread_go_locked(thread, THREAD_AWAKENED);
                (void)rem_runq(thread);
                thread_unlock(thread);
                splx(s);

                simple_lock(&pset->processors_lock);
                enable_preemption();
        }

        s = splsched();
        processor_lock(processor);

        /*
         *      Do shutdown, make sure we live when processor dies.
         */
        if (processor->state != PROCESSOR_SHUTDOWN) {
                panic("action_thread -- bad processor state");
        }

        pset_remove_processor(pset, processor);
        processor_unlock(processor);
        simple_unlock(&pset->processors_lock);

        /*
         *      Clean up.
         */
        thread_bind(self, PROCESSOR_NULL);
        self->continuation = 0;
        old_thread = switch_to_shutdown_context(self,
                                                                        processor_doshutdown, processor);
        if (processor != current_processor())
                timer_call_shutdown(processor);
        thread_dispatch(old_thread);
        thread_wakeup((event_t)processor);
        splx(s);
}

/*
 *      Actually do the processor shutdown.  This is called at splsched,
 *      running on the processor's shutdown stack.
 */

void
processor_doshutdown(
        processor_t             processor)
{
        register int    cpu = processor->slot_num;

        timer_call_cancel(&processor->quantum_timer);
        thread_dispatch(current_thread());
        timer_switch(&kernel_timer[cpu]);

        /*
         *      OK, now exit this cpu.
         */
        PMAP_DEACTIVATE_KERNEL(cpu);
        thread_machine_set_current(processor->idle_thread);
        cpu_down(cpu);
        cpu_sleep();
        panic("zombie processor");
        /*NOTREACHED*/
}

kern_return_t
host_get_boot_info(
        host_priv_t         host_priv,
        kernel_boot_info_t  boot_info)
{
        char *src = "";
        extern char *machine_boot_info(
                                kernel_boot_info_t      boot_info,
                                vm_size_t                       buf_len);

        if (host_priv == HOST_PRIV_NULL)
                return (KERN_INVALID_HOST);

        assert(host_priv == &realhost);

        /*
         * Copy first operator string terminated by '\0' followed by
         *      standardized strings generated from boot string.
         */
        src = machine_boot_info(boot_info, KERNEL_BOOT_INFO_MAX);
        if (src != boot_info)
                (void) strncpy(boot_info, src, KERNEL_BOOT_INFO_MAX);

        return (KERN_SUCCESS);
}