/*
* Copyright (c) 2008 Jiri Svoboda
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/** @addtogroup genericipc
* @{
*/
/** @file
*/
#include <synch/synch.h>
#include <synch/spinlock.h>
#include <synch/mutex.h>
#include <ipc/ipc.h>
#include <ipc/ipcrsc.h>
#include <arch.h>
#include <errno.h>
#include <debug.h>
#include <udebug/udebug_ipc.h>
#include <ipc/kbox.h>
void ipc_kbox_cleanup(void)
{
ipl_t ipl;
bool have_kb_thread;
/* Only hold kb_cleanup_lock while setting kb_finished - this is enough */
mutex_lock(&TASK->kb_cleanup_lock);
TASK->kb_finished = true;
mutex_unlock(&TASK->kb_cleanup_lock);
have_kb_thread = (TASK->kb_thread != NULL);
/* From now on nobody will try to connect phones or attach kbox threads */
/*
* Disconnect all phones connected to our kbox. Passing true for
* notify_box causes a HANGUP message to be inserted for each
* disconnected phone. This ensures the kbox thread is going to
* wake up and terminate.
*/
ipc_answerbox_slam_phones(&TASK->kernel_box, have_kb_thread);
/*
* If the task was being debugged, clean up debugging session.
* This is necessarry as slamming the phones won't force
* kbox thread to clean it up since sender != debugger.
*/
ipl = interrupts_disable();
spinlock_lock(&TASK->lock);
udebug_task_cleanup(TASK);
spinlock_unlock(&TASK->lock);
interrupts_restore(ipl);
if (have_kb_thread) {
LOG("join kb_thread..\n");
thread_join(TASK->kb_thread);
thread_detach(TASK->kb_thread);
LOG("join done\n");
TASK->kb_thread = NULL;
}
/* Answer all messages in 'calls' and 'dispatched_calls' queues */
spinlock_lock(&TASK->kernel_box.lock);
ipc_cleanup_call_list(&TASK->kernel_box.dispatched_calls);
ipc_cleanup_call_list(&TASK->kernel_box.calls);
spinlock_unlock(&TASK->kernel_box.lock);
}
/** Handle hangup message in kbox.
*
* @param call The IPC_M_PHONE_HUNGUP call structure.
* @param last Output, the function stores @c true here if
* this was the last phone, @c false otherwise.
**/
static void kbox_proc_phone_hungup(call_t *call, bool *last)
{
ipl_t ipl;
LOG("kbox_proc_phone_hungup()\n");
/* Was it our debugger, who hung up? */
if (call->sender == TASK->udebug.debugger) {
/* Terminate debugging session (if any) */
LOG("kbox: terminate debug session\n");
ipl = interrupts_disable();
spinlock_lock(&TASK->lock);
udebug_task_cleanup(TASK);
spinlock_unlock(&TASK->lock);
interrupts_restore(ipl);
} else {
LOG("kbox: was not debugger\n");
}
LOG("kbox: continue with hangup message\n");
IPC_SET_RETVAL(call->data, 0);
ipc_answer(&TASK->kernel_box, call);
ipl = interrupts_disable();
spinlock_lock(&TASK->lock);
spinlock_lock(&TASK->answerbox.lock);
if (list_empty(&TASK->answerbox.connected_phones)) {
/*
* Last phone has been disconnected. Detach this thread so it
* gets freed and signal to the caller.
*/
/* Only detach kbox thread unless already terminating. */
mutex_lock(&TASK->kb_cleanup_lock);
if (&TASK->kb_finished == false) {
/* Detach kbox thread so it gets freed from memory. */
thread_detach(TASK->kb_thread);
TASK->kb_thread = NULL;
}
mutex_unlock(&TASK->kb_cleanup_lock);
LOG("phone list is empty\n");
*last = true;
} else {
*last = false;
}
spinlock_unlock(&TASK->answerbox.lock);
spinlock_unlock(&TASK->lock);
interrupts_restore(ipl);
}
/** Implementing function for the kbox thread.
*
* This function listens for debug requests. It terminates
* when all phones are disconnected from the kbox.
*
* @param arg Ignored.
*/
static void kbox_thread_proc(void *arg)
{
call_t *call;
bool done;
(void)arg;
LOG("kbox_thread_proc()\n");
done = false;
while (!done) {
call = ipc_wait_for_call(&TASK->kernel_box, SYNCH_NO_TIMEOUT,
SYNCH_FLAGS_NONE);
if (call == NULL)
continue; /* Try again. */
switch (IPC_GET_METHOD(call->data)) {
case IPC_M_DEBUG_ALL:
/* Handle debug call. */
udebug_call_receive(call);
break;
case IPC_M_PHONE_HUNGUP:
/*
* Process the hangup call. If this was the last
* phone, done will be set to true and the
* while loop will terminate.
*/
kbox_proc_phone_hungup(call, &done);
break;
default:
/* Ignore */
break;
}
}
LOG("kbox: finished\n");
}
/**
* Connect phone to a task kernel-box specified by id.
*
* Note that this is not completely atomic. For optimisation reasons,
* The task might start cleaning up kbox after the phone has been connected
* and before a kbox thread has been created. This must be taken into account
* in the cleanup code.
*
* @return Phone id on success, or negative error code.
*/
int ipc_connect_kbox(task_id_t taskid)
{
int newphid;
task_t *ta;
thread_t *kb_thread;
ipl_t ipl;
ipl = interrupts_disable();
spinlock_lock(&tasks_lock);
ta = task_find_by_id(taskid);
if (ta == NULL) {
spinlock_unlock(&tasks_lock);
interrupts_restore(ipl);
return ENOENT;
}
atomic_inc(&ta->refcount);
spinlock_unlock(&tasks_lock);
interrupts_restore(ipl);
mutex_lock(&ta->kb_cleanup_lock);
if (atomic_predec(&ta->refcount) == 0) {
mutex_unlock(&ta->kb_cleanup_lock);
task_destroy(ta);
return ENOENT;
}
if (ta->kb_finished != false) {
mutex_unlock(&ta->kb_cleanup_lock);
return EINVAL;
}
newphid = phone_alloc();
if (newphid < 0) {
mutex_unlock(&ta->kb_cleanup_lock);
return ELIMIT;
}
/* Connect the newly allocated phone to the kbox */
ipc_phone_connect(&TASK->phones[newphid], &ta->kernel_box);
if (ta->kb_thread != NULL) {
mutex_unlock(&ta->kb_cleanup_lock);
return newphid;
}
/* Create a kbox thread */
kb_thread = thread_create(kbox_thread_proc, NULL, ta, 0, "kbox", false);
if (!kb_thread) {
mutex_unlock(&ta->kb_cleanup_lock);
return ENOMEM;
}
ta->kb_thread = kb_thread;
thread_ready(kb_thread);
mutex_unlock(&ta->kb_cleanup_lock);
return newphid;
}
/** @}
*/