init gnumach copy

1 files changed, 672 insertions, 0 deletions

diff --git a/kern/machine.c b/kern/machine.c
new file mode 100644
index 0000000..f757d14
--- /dev/null
+++ b/kern/machine.c
@@ -0,0 +1,672 @@
+/*
+ * Mach Operating System
+ * Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University.
+ * Copyright (c) 1993,1994 The University of Utah and
+ * the Computer Systems Laboratory (CSL).
+ * 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, THE UNIVERSITY OF UTAH AND CSL ALLOW FREE USE OF
+ * THIS SOFTWARE IN ITS "AS IS" CONDITION, AND DISCLAIM 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 <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 <kern/counters.h>
+#include <kern/debug.h>
+#include <kern/ipc_host.h>
+#include <kern/host.h>
+#include <kern/machine.h>
+#include <kern/mach_host.server.h>
+#include <kern/lock.h>
+#include <kern/processor.h>
+#include <kern/queue.h>
+#include <kern/sched.h>
+#include <kern/task.h>
+#include <kern/thread.h>
+#include <kern/printf.h>
+#include <machine/machspl.h>	/* for splsched */
+#include <machine/model_dep.h>
+#include <machine/pcb.h>
+#include <sys/reboot.h>
+
+
+
+/*
+ *	Exported variables:
+ */
+
+struct machine_info	machine_info;
+struct machine_slot	machine_slot[NCPUS];
+
+queue_head_t	action_queue;	/* assign/shutdown queue */
+def_simple_lock_data(,action_lock);
+
+/*
+ *	cpu_up:
+ *
+ *	Flag specified cpu as up and running.  Called when a processor comes
+ *	online.
+ */
+void cpu_up(int cpu)
+{
+	struct machine_slot	*ms;
+	processor_t		processor;
+	spl_t 			s;
+
+	processor = cpu_to_processor(cpu);
+	pset_lock(&default_pset);
+#if	MACH_HOST
+	pset_lock(slave_pset);
+#endif
+	s = splsched();
+	processor_lock(processor);
+#if	NCPUS > 1
+	init_ast_check(processor);
+#endif	/* NCPUS > 1 */
+	ms = &machine_slot[cpu];
+	ms->running = TRUE;
+	machine_info.avail_cpus++;
+#if	MACH_HOST
+	if (cpu != 0)
+		pset_add_processor(slave_pset, processor);
+	else
+#endif
+		pset_add_processor(&default_pset, processor);
+	processor->state = PROCESSOR_RUNNING;
+	processor_unlock(processor);
+	splx(s);
+#if	MACH_HOST
+	pset_unlock(slave_pset);
+#endif
+	pset_unlock(&default_pset);
+}
+
+kern_return_t
+host_reboot(const host_t host, int options)
+{
+	if (host == HOST_NULL)
+		return (KERN_INVALID_HOST);
+
+	if (options & RB_DEBUGGER) {
+		Debugger("Debugger");
+	} else {
+#ifdef parisc
+/* XXX this could be made common */
+		halt_all_cpus(options);
+#else
+		halt_all_cpus(!(options & RB_HALT));
+#endif
+	}
+	return (KERN_SUCCESS);
+}
+
+#if	NCPUS > 1
+
+/*
+ *	cpu_down:
+ *
+ *	Flag specified cpu as down.  Called when a processor is about to
+ *	go offline.
+ */
+static void cpu_down(int cpu)
+{
+	struct machine_slot	*ms;
+	processor_t		processor;
+	spl_t			s;
+
+	s = splsched();
+	processor = cpu_to_processor(cpu);
+	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);
+}
+
+/*
+ *	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.
+ */
+static void
+processor_request_action(
+	processor_t	processor,
+	processor_set_t	new_pset)
+{
+    processor_set_t 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->idle_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)
+	cpu_pause();
+
+    /*
+     *	Now lock the action queue and do the dirty work.
+     */
+    simple_lock(&action_lock);
+
+    switch (processor->state) {
+	case PROCESSOR_IDLE:
+	    /*
+	     *	Remove from idle queue.
+	     */
+	    queue_remove(&pset->idle_queue, processor, 	processor_t,
+		processor_queue);
+	    pset->idle_count--;
+
+	    /* fall through ... */
+	case PROCESSOR_RUNNING:
+	    /*
+	     *	Put it on the action queue.
+	     */
+	    queue_enter(&action_queue, processor, processor_t,
+		processor_queue);
+
+	    /* fall through ... */
+	case PROCESSOR_ASSIGN:
+	    /*
+	     * And ask the action_thread to do the work.
+	     */
+
+	    if (new_pset == PROCESSOR_SET_NULL) {
+		processor->state = PROCESSOR_SHUTDOWN;
+	    }
+	    else {
+		assert(processor->state != PROCESSOR_ASSIGN);
+		processor->state = PROCESSOR_ASSIGN;
+	        processor->processor_set_next = new_pset;
+	    }
+	    break;
+
+	default:
+	    printf("state: %d\n", processor->state);
+	    panic("processor_request_action: bad state");
+    }
+    simple_unlock(&action_lock);
+    simple_unlock(&pset->idle_lock);
+
+    thread_wakeup((event_t)&action_queue);
+}
+
+#if	MACH_HOST
+/*
+ *	processor_assign() changes the processor set that a processor is
+ *	assigned to.  Any previous assignment in progress is overridden.
+ *	Synchronizes with assignment completion if wait is TRUE.
+ */
+kern_return_t
+processor_assign(
+	processor_t	processor,
+	processor_set_t	new_pset,
+	boolean_t	wait)
+{
+    spl_t		s;
+
+    /*
+     *	Check for null arguments.
+     *  XXX Can't assign master processor.
+     */
+    if (processor == PROCESSOR_NULL || new_pset == PROCESSOR_SET_NULL ||
+	processor == master_processor) {
+	    return(KERN_INVALID_ARGUMENT);
+    }
+
+    /*
+     *	Get pset reference to donate to processor_request_action.
+     */
+    pset_reference(new_pset);
+
+    /*
+     * Check processor status.
+     * If shutdown or being shutdown, can`t reassign.
+     * If being assigned, wait for assignment to finish.
+     */
+Retry:
+    s = splsched();
+    processor_lock(processor);
+    if(processor->state == PROCESSOR_OFF_LINE ||
+	processor->state == PROCESSOR_SHUTDOWN) {
+	    /*
+	     *	Already shutdown or being shutdown -- Can't reassign.
+	     */
+	    processor_unlock(processor);
+	    (void) splx(s);
+	    pset_deallocate(new_pset);
+	    return(KERN_FAILURE);
+    }
+
+    if (processor->state == PROCESSOR_ASSIGN) {
+	assert_wait((event_t) processor, TRUE);
+	processor_unlock(processor);
+	splx(s);
+	thread_block(thread_no_continuation);
+	goto Retry;
+    }
+	 
+    /*
+     *	Avoid work if processor is already in this processor set.
+     */
+    if (processor->processor_set == new_pset)  {
+	processor_unlock(processor);
+	(void) splx(s);
+	/* clean up dangling ref */
+	pset_deallocate(new_pset);
+	return(KERN_SUCCESS);
+    }
+
+    /*
+     * OK to start processor assignment.
+     */
+    processor_request_action(processor, new_pset);
+
+    /*
+     *	Synchronization with completion.
+     */
+    if (wait) {
+	while (processor->state == PROCESSOR_ASSIGN ||
+	    processor->state == PROCESSOR_SHUTDOWN) {
+		assert_wait((event_t)processor, TRUE);
+		processor_unlock(processor);
+		splx(s);
+		thread_block(thread_no_continuation);
+		s = splsched();
+		processor_lock(processor);
+	}
+    }
+    processor_unlock(processor);
+    splx(s);
+    
+    return(KERN_SUCCESS);
+}
+
+#else	/* MACH_HOST */
+
+kern_return_t
+processor_assign(
+	processor_t	processor,
+	processor_set_t	new_pset,
+	boolean_t	wait)
+{
+	return KERN_FAILURE;
+}
+
+#endif	/* MACH_HOST */
+
+/*
+ *	processor_shutdown() queues a processor up for shutdown.
+ *	Any assignment in progress is overriden.  It does not synchronize
+ *	with the shutdown (can be called from interrupt level).
+ */
+kern_return_t
+processor_shutdown(processor_t processor)
+{
+    spl_t		s;
+
+    if (processor == PROCESSOR_NULL)
+	return KERN_INVALID_ARGUMENT;
+
+    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);
+    processor_unlock(processor);
+    splx(s);
+
+    return(KERN_SUCCESS);
+}
+
+/*
+ *	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.
+ */
+static void processor_doaction(processor_t processor)
+{
+	thread_t			this_thread;
+	spl_t				s;
+	processor_set_t			pset;
+#if	MACH_HOST
+	processor_set_t			new_pset;
+	thread_t			thread;
+	thread_t			prev_thread = THREAD_NULL;
+	boolean_t			have_pset_ref = FALSE;
+#endif	/* MACH_HOST */
+
+	/*
+	 *	Get onto the processor to shutdown
+	 */
+	this_thread = current_thread();
+	thread_bind(this_thread, processor);
+	thread_block(thread_no_continuation);
+
+	pset = processor->processor_set;
+#if	MACH_HOST
+	/*
+	 *	If this is the last processor in the processor_set,
+	 *	stop all the threads first.
+	 */
+	pset_lock(pset);
+	if (pset->processor_count == 1) {
+		/*
+		 *	First suspend all of them.
+		 */
+		queue_iterate(&pset->threads, thread, thread_t, pset_threads) {
+			thread_hold(thread);
+		}
+		pset->empty = TRUE;
+		/*
+		 *	Now actually stop them.  Need a pset reference.
+		 */
+		pset->ref_count++;
+		have_pset_ref = TRUE;
+
+Restart_thread:
+		prev_thread = THREAD_NULL;
+		queue_iterate(&pset->threads, thread, thread_t, pset_threads) {
+			thread_reference(thread);
+			pset_unlock(pset);
+			if (prev_thread != THREAD_NULL)
+				thread_deallocate(prev_thread);
+
+			/*
+			 *	Only wait for threads still in the pset.
+			 */
+			thread_freeze(thread);
+			if (thread->processor_set != pset) {
+				/*
+				 *	It got away - start over.
+				 */
+				thread_unfreeze(thread);
+				thread_deallocate(thread);
+				pset_lock(pset);
+				goto Restart_thread;
+			}
+
+			(void) thread_dowait(thread, TRUE);
+			prev_thread = thread;
+			pset_lock(pset);
+			thread_unfreeze(prev_thread);
+		}
+	}
+	pset_unlock(pset);
+
+	/*
+	 *	At this point, it is ok to remove the processor from the pset.
+	 *	We can use processor->processor_set_next without locking the
+	 *	processor, since it cannot change while processor->state is
+	 *	PROCESSOR_ASSIGN or PROCESSOR_SHUTDOWN.
+	 */
+
+	new_pset = processor->processor_set_next;
+
+Restart_pset:
+	if (new_pset) {
+	    /*
+	     *	Reassigning processor.
+	     */
+
+	    if ((integer_t) pset < (integer_t) new_pset) {
+		pset_lock(pset);
+		pset_lock(new_pset);
+	    }
+	    else {
+		pset_lock(new_pset);
+		pset_lock(pset);
+	    }
+	    if (!(new_pset->active)) {
+		pset_unlock(new_pset);
+		pset_unlock(pset);
+		pset_deallocate(new_pset);
+		new_pset = &default_pset;
+		pset_reference(new_pset);
+		goto Restart_pset;
+	    }
+
+	    /*
+	     *  Handle remove last / assign first race.
+	     *	Only happens if there is more than one action thread.
+	     */
+	    while (new_pset->empty && new_pset->processor_count > 0) {
+		pset_unlock(new_pset);
+		pset_unlock(pset);
+		while (*(volatile boolean_t *)&new_pset->empty &&
+		       *(volatile int *)&new_pset->processor_count > 0)
+			/* spin */;
+		goto Restart_pset;
+	    }
+
+	    /*
+	     *	Lock the processor.  new_pset should not have changed.
+	     */
+	    s = splsched();
+	    processor_lock(processor);
+	    assert(processor->processor_set_next == new_pset);
+
+	    /*
+	     *	Shutdown may have been requested while this assignment
+	     *	was in progress.
+	     */
+	    if (processor->state == PROCESSOR_SHUTDOWN) {
+		processor->processor_set_next = PROCESSOR_SET_NULL;
+		pset_unlock(new_pset);
+		goto shutdown;	/* releases pset reference */
+	    }
+
+	    /*
+	     *	Do assignment, then wakeup anyone waiting for it.
+	     */
+	    pset_remove_processor(pset, processor);
+	    pset_unlock(pset);
+
+	    pset_add_processor(new_pset, processor);
+	    if (new_pset->empty) {
+		/*
+		 *	Set all the threads loose.
+		 *
+		 *	NOTE: this appears to violate the locking
+		 *	order, since the processor lock should
+		 *	be taken AFTER a thread lock.  However,
+		 *	thread_setrun (called by thread_release)
+		 *	only takes the processor lock if the
+		 *	processor is idle.  The processor is
+		 *	not idle here.
+		 */
+		queue_iterate(&new_pset->threads, thread, thread_t,
+			      pset_threads) {
+		    thread_release(thread);
+		}
+		new_pset->empty = FALSE;
+	    }
+	    processor->processor_set_next = PROCESSOR_SET_NULL;
+	    processor->state = PROCESSOR_RUNNING;
+	    thread_wakeup((event_t)processor);
+	    processor_unlock(processor);
+	    splx(s);
+	    pset_unlock(new_pset);
+
+	    /*
+	     *	Clean up dangling references, and release our binding.
+	     */
+	    pset_deallocate(new_pset);
+	    if (have_pset_ref)
+		pset_deallocate(pset);
+	    if (prev_thread != THREAD_NULL)
+		thread_deallocate(prev_thread);
+	    thread_bind(this_thread, PROCESSOR_NULL);
+
+	    thread_block(thread_no_continuation);
+	    return;
+	}
+
+#endif	/* MACH_HOST */
+	
+	/*
+	 *	Do shutdown, make sure we live when processor dies.
+	 */
+	if (processor->state != PROCESSOR_SHUTDOWN) {
+		printf("state: %d\n", processor->state);
+	    	panic("action_thread -- bad processor state");
+	}
+
+	s = splsched();
+	processor_lock(processor);
+
+#if	MACH_HOST
+    shutdown:
+#endif	/* MACH_HOST */
+	pset_remove_processor(pset, processor);
+	processor_unlock(processor);
+	pset_unlock(pset);
+	splx(s);
+
+	/*
+	 *	Clean up dangling references, and release our binding.
+	 */
+#if	MACH_HOST
+	if (new_pset != PROCESSOR_SET_NULL)
+		pset_deallocate(new_pset);
+	if (have_pset_ref)
+		pset_deallocate(pset);
+	if (prev_thread != THREAD_NULL)
+		thread_deallocate(prev_thread);
+#endif	/* MACH_HOST */
+
+	thread_bind(this_thread, PROCESSOR_NULL);
+	switch_to_shutdown_context(this_thread,
+				   processor_doshutdown,
+				   processor);
+
+}
+
+/*
+ *	action_thread() shuts down processors or changes their assignment.
+ */
+void __attribute__((noreturn)) action_thread_continue(void)
+{
+	processor_t	processor;
+	spl_t		s;
+
+	while (TRUE) {
+		s = splsched();
+		simple_lock(&action_lock);
+		while ( !queue_empty(&action_queue)) {
+			processor = (processor_t) queue_first(&action_queue);
+			queue_remove(&action_queue, processor, processor_t,
+				     processor_queue);
+			simple_unlock(&action_lock);
+			(void) splx(s);
+
+			processor_doaction(processor);
+
+			s = splsched();
+			simple_lock(&action_lock);
+		}
+
+		assert_wait((event_t) &action_queue, FALSE);
+		simple_unlock(&action_lock);
+		(void) splx(s);
+		counter(c_action_thread_block++);
+		thread_block(action_thread_continue);
+	}
+}
+
+void __attribute__((noreturn)) action_thread(void)
+{
+	action_thread_continue();
+	/*NOTREACHED*/
+}
+
+/*
+ *	Actually do the processor shutdown.  This is called at splsched,
+ *	running on the processor's shutdown stack.
+ */
+
+void processor_doshutdown(processor_t processor)
+{
+	int		cpu = processor->slot_num;
+
+	timer_switch(&kernel_timer[cpu]);
+
+	/*
+	 *	Ok, now exit this cpu.
+	 */
+	PMAP_DEACTIVATE_KERNEL(cpu);
+#ifndef MIGRATING_THREADS
+	percpu_array[cpu].active_thread = THREAD_NULL;
+#endif
+	cpu_down(cpu);
+	thread_wakeup((event_t)processor);
+	halt_cpu();
+	/*
+	 *	The action thread returns to life after the call to
+	 *	switch_to_shutdown_context above, on some other cpu.
+	 */
+
+	/*NOTREACHED*/
+}
+#else	/* NCPUS > 1 */
+
+kern_return_t
+processor_assign(
+	processor_t	processor,
+	processor_set_t	new_pset,
+	boolean_t	wait)
+{
+	return(KERN_FAILURE);
+}
+
+#endif /* NCPUS > 1 */