Orange Pi5 kernel

/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (c) 2004-2009 Silicon Graphics, Inc.  All Rights Reserved.
 */
 
/*
 * Cross Partition Communication (XPC) channel support.
 *
 *	This is the part of XPC that manages the channels and
 *	sends/receives messages across them to/from other partitions.
 *
 */
 
#include <linux/device.h>
#include "xpc.h"
 
/*
 * Process a connect message from a remote partition.
 *
 * Note: xpc_process_connect() is expecting to be called with the
 * spin_lock_irqsave held and will leave it locked upon return.
 */
static void
xpc_process_connect(struct xpc_channel *ch, unsigned long *irq_flags)
{
<------>enum xp_retval ret;
 
<------>lockdep_assert_held(&ch->lock);
 
<------>if (!(ch->flags & XPC_C_OPENREQUEST) ||
<------>    !(ch->flags & XPC_C_ROPENREQUEST)) {
<------><------>/* nothing more to do for now */
<------><------>return;
<------>}
<------>DBUG_ON(!(ch->flags & XPC_C_CONNECTING));
 
<------>if (!(ch->flags & XPC_C_SETUP)) {
<------><------>spin_unlock_irqrestore(&ch->lock, *irq_flags);
<------><------>ret = xpc_arch_ops.setup_msg_structures(ch);
<------><------>spin_lock_irqsave(&ch->lock, *irq_flags);
 
<------><------>if (ret != xpSuccess)
<------><------><------>XPC_DISCONNECT_CHANNEL(ch, ret, irq_flags);
<------><------>else
<------><------><------>ch->flags |= XPC_C_SETUP;
 
<------><------>if (ch->flags & XPC_C_DISCONNECTING)
<------><------><------>return;
<------>}
 
<------>if (!(ch->flags & XPC_C_OPENREPLY)) {
<------><------>ch->flags |= XPC_C_OPENREPLY;
<------><------>xpc_arch_ops.send_chctl_openreply(ch, irq_flags);
<------>}
 
<------>if (!(ch->flags & XPC_C_ROPENREPLY))
<------><------>return;
 
<------>if (!(ch->flags & XPC_C_OPENCOMPLETE)) {
<------><------>ch->flags |= (XPC_C_OPENCOMPLETE | XPC_C_CONNECTED);
<------><------>xpc_arch_ops.send_chctl_opencomplete(ch, irq_flags);
<------>}
 
<------>if (!(ch->flags & XPC_C_ROPENCOMPLETE))
<------><------>return;
 
<------>dev_info(xpc_chan, "channel %d to partition %d connected\n",
<------><------> ch->number, ch->partid);
 
<------>ch->flags = (XPC_C_CONNECTED | XPC_C_SETUP);	/* clear all else */
}
 
/*
 * spin_lock_irqsave() is expected to be held on entry.
 */
static void
xpc_process_disconnect(struct xpc_channel *ch, unsigned long *irq_flags)
{
<------>struct xpc_partition *part = &xpc_partitions[ch->partid];
<------>u32 channel_was_connected = (ch->flags & XPC_C_WASCONNECTED);
 
<------>lockdep_assert_held(&ch->lock);
 
<------>if (!(ch->flags & XPC_C_DISCONNECTING))
<------><------>return;
 
<------>DBUG_ON(!(ch->flags & XPC_C_CLOSEREQUEST));
 
<------>/* make sure all activity has settled down first */
 
<------>if (atomic_read(&ch->kthreads_assigned) > 0 ||
<------>    atomic_read(&ch->references) > 0) {
<------><------>return;
<------>}
<------>DBUG_ON((ch->flags & XPC_C_CONNECTEDCALLOUT_MADE) &&
<------><------>!(ch->flags & XPC_C_DISCONNECTINGCALLOUT_MADE));
 
<------>if (part->act_state == XPC_P_AS_DEACTIVATING) {
<------><------>/* can't proceed until the other side disengages from us */
<------><------>if (xpc_arch_ops.partition_engaged(ch->partid))
<------><------><------>return;
 
<------>} else {
 
<------><------>/* as long as the other side is up do the full protocol */
 
<------><------>if (!(ch->flags & XPC_C_RCLOSEREQUEST))
<------><------><------>return;
 
<------><------>if (!(ch->flags & XPC_C_CLOSEREPLY)) {
<------><------><------>ch->flags |= XPC_C_CLOSEREPLY;
<------><------><------>xpc_arch_ops.send_chctl_closereply(ch, irq_flags);
<------><------>}
 
<------><------>if (!(ch->flags & XPC_C_RCLOSEREPLY))
<------><------><------>return;
<------>}
 
<------>/* wake those waiting for notify completion */
<------>if (atomic_read(&ch->n_to_notify) > 0) {
<------><------>/* we do callout while holding ch->lock, callout can't block */
<------><------>xpc_arch_ops.notify_senders_of_disconnect(ch);
<------>}
 
<------>/* both sides are disconnected now */
 
<------>if (ch->flags & XPC_C_DISCONNECTINGCALLOUT_MADE) {
<------><------>spin_unlock_irqrestore(&ch->lock, *irq_flags);
<------><------>xpc_disconnect_callout(ch, xpDisconnected);
<------><------>spin_lock_irqsave(&ch->lock, *irq_flags);
<------>}
 
<------>DBUG_ON(atomic_read(&ch->n_to_notify) != 0);
 
<------>/* it's now safe to free the channel's message queues */
<------>xpc_arch_ops.teardown_msg_structures(ch);
 
<------>ch->func = NULL;
<------>ch->key = NULL;
<------>ch->entry_size = 0;
<------>ch->local_nentries = 0;
<------>ch->remote_nentries = 0;
<------>ch->kthreads_assigned_limit = 0;
<------>ch->kthreads_idle_limit = 0;
 
<------>/*
<------> * Mark the channel disconnected and clear all other flags, including
<------> * XPC_C_SETUP (because of call to
<------> * xpc_arch_ops.teardown_msg_structures()) but not including
<------> * XPC_C_WDISCONNECT (if it was set).
<------> */
<------>ch->flags = (XPC_C_DISCONNECTED | (ch->flags & XPC_C_WDISCONNECT));
 
<------>atomic_dec(&part->nchannels_active);
 
<------>if (channel_was_connected) {
<------><------>dev_info(xpc_chan, "channel %d to partition %d disconnected, "
<------><------><------> "reason=%d\n", ch->number, ch->partid, ch->reason);
<------>}
 
<------>if (ch->flags & XPC_C_WDISCONNECT) {
<------><------>/* we won't lose the CPU since we're holding ch->lock */
<------><------>complete(&ch->wdisconnect_wait);
<------>} else if (ch->delayed_chctl_flags) {
<------><------>if (part->act_state != XPC_P_AS_DEACTIVATING) {
<------><------><------>/* time to take action on any delayed chctl flags */
<------><------><------>spin_lock(&part->chctl_lock);
<------><------><------>part->chctl.flags[ch->number] |=
<------><------><------>    ch->delayed_chctl_flags;
<------><------><------>spin_unlock(&part->chctl_lock);
<------><------>}
<------><------>ch->delayed_chctl_flags = 0;
<------>}
}
 
/*
 * Process a change in the channel's remote connection state.
 */
static void
xpc_process_openclose_chctl_flags(struct xpc_partition *part, int ch_number,
<------><------><------><------>  u8 chctl_flags)
{
<------>unsigned long irq_flags;
<------>struct xpc_openclose_args *args =
<------>    &part->remote_openclose_args[ch_number];
<------>struct xpc_channel *ch = &part->channels[ch_number];
<------>enum xp_retval reason;
<------>enum xp_retval ret;
<------>int create_kthread = 0;
 
<------>spin_lock_irqsave(&ch->lock, irq_flags);
 
again:
 
<------>if ((ch->flags & XPC_C_DISCONNECTED) &&
<------>    (ch->flags & XPC_C_WDISCONNECT)) {
<------><------>/*
<------><------> * Delay processing chctl flags until thread waiting disconnect
<------><------> * has had a chance to see that the channel is disconnected.
<------><------> */
<------><------>ch->delayed_chctl_flags |= chctl_flags;
<------><------>goto out;
<------>}
 
<------>if (chctl_flags & XPC_CHCTL_CLOSEREQUEST) {
 
<------><------>dev_dbg(xpc_chan, "XPC_CHCTL_CLOSEREQUEST (reason=%d) received "
<------><------><------>"from partid=%d, channel=%d\n", args->reason,
<------><------><------>ch->partid, ch->number);
 
<------><------>/*
<------><------> * If RCLOSEREQUEST is set, we're probably waiting for
<------><------> * RCLOSEREPLY. We should find it and a ROPENREQUEST packed
<------><------> * with this RCLOSEREQUEST in the chctl_flags.
<------><------> */
 
<------><------>if (ch->flags & XPC_C_RCLOSEREQUEST) {
<------><------><------>DBUG_ON(!(ch->flags & XPC_C_DISCONNECTING));
<------><------><------>DBUG_ON(!(ch->flags & XPC_C_CLOSEREQUEST));
<------><------><------>DBUG_ON(!(ch->flags & XPC_C_CLOSEREPLY));
<------><------><------>DBUG_ON(ch->flags & XPC_C_RCLOSEREPLY);
 
<------><------><------>DBUG_ON(!(chctl_flags & XPC_CHCTL_CLOSEREPLY));
<------><------><------>chctl_flags &= ~XPC_CHCTL_CLOSEREPLY;
<------><------><------>ch->flags |= XPC_C_RCLOSEREPLY;
 
<------><------><------>/* both sides have finished disconnecting */
<------><------><------>xpc_process_disconnect(ch, &irq_flags);
<------><------><------>DBUG_ON(!(ch->flags & XPC_C_DISCONNECTED));
<------><------><------>goto again;
<------><------>}
 
<------><------>if (ch->flags & XPC_C_DISCONNECTED) {
<------><------><------>if (!(chctl_flags & XPC_CHCTL_OPENREQUEST)) {
<------><------><------><------>if (part->chctl.flags[ch_number] &
<------><------><------><------>    XPC_CHCTL_OPENREQUEST) {
 
<------><------><------><------><------>DBUG_ON(ch->delayed_chctl_flags != 0);
<------><------><------><------><------>spin_lock(&part->chctl_lock);
<------><------><------><------><------>part->chctl.flags[ch_number] |=
<------><------><------><------><------>    XPC_CHCTL_CLOSEREQUEST;
<------><------><------><------><------>spin_unlock(&part->chctl_lock);
<------><------><------><------>}
<------><------><------><------>goto out;
<------><------><------>}
 
<------><------><------>XPC_SET_REASON(ch, 0, 0);
<------><------><------>ch->flags &= ~XPC_C_DISCONNECTED;
 
<------><------><------>atomic_inc(&part->nchannels_active);
<------><------><------>ch->flags |= (XPC_C_CONNECTING | XPC_C_ROPENREQUEST);
<------><------>}
 
<------><------>chctl_flags &= ~(XPC_CHCTL_OPENREQUEST | XPC_CHCTL_OPENREPLY |
<------><------>    XPC_CHCTL_OPENCOMPLETE);
 
<------><------>/*
<------><------> * The meaningful CLOSEREQUEST connection state fields are:
<------><------> *      reason = reason connection is to be closed
<------><------> */
 
<------><------>ch->flags |= XPC_C_RCLOSEREQUEST;
 
<------><------>if (!(ch->flags & XPC_C_DISCONNECTING)) {
<------><------><------>reason = args->reason;
<------><------><------>if (reason <= xpSuccess || reason > xpUnknownReason)
<------><------><------><------>reason = xpUnknownReason;
<------><------><------>else if (reason == xpUnregistering)
<------><------><------><------>reason = xpOtherUnregistering;
 
<------><------><------>XPC_DISCONNECT_CHANNEL(ch, reason, &irq_flags);
 
<------><------><------>DBUG_ON(chctl_flags & XPC_CHCTL_CLOSEREPLY);
<------><------><------>goto out;
<------><------>}
 
<------><------>xpc_process_disconnect(ch, &irq_flags);
<------>}
 
<------>if (chctl_flags & XPC_CHCTL_CLOSEREPLY) {
 
<------><------>dev_dbg(xpc_chan, "XPC_CHCTL_CLOSEREPLY received from partid="
<------><------><------>"%d, channel=%d\n", ch->partid, ch->number);
 
<------><------>if (ch->flags & XPC_C_DISCONNECTED) {
<------><------><------>DBUG_ON(part->act_state != XPC_P_AS_DEACTIVATING);
<------><------><------>goto out;
<------><------>}
 
<------><------>DBUG_ON(!(ch->flags & XPC_C_CLOSEREQUEST));
 
<------><------>if (!(ch->flags & XPC_C_RCLOSEREQUEST)) {
<------><------><------>if (part->chctl.flags[ch_number] &
<------><------><------>    XPC_CHCTL_CLOSEREQUEST) {
 
<------><------><------><------>DBUG_ON(ch->delayed_chctl_flags != 0);
<------><------><------><------>spin_lock(&part->chctl_lock);
<------><------><------><------>part->chctl.flags[ch_number] |=
<------><------><------><------>    XPC_CHCTL_CLOSEREPLY;
<------><------><------><------>spin_unlock(&part->chctl_lock);
<------><------><------>}
<------><------><------>goto out;
<------><------>}
 
<------><------>ch->flags |= XPC_C_RCLOSEREPLY;
 
<------><------>if (ch->flags & XPC_C_CLOSEREPLY) {
<------><------><------>/* both sides have finished disconnecting */
<------><------><------>xpc_process_disconnect(ch, &irq_flags);
<------><------>}
<------>}
 
<------>if (chctl_flags & XPC_CHCTL_OPENREQUEST) {
 
<------><------>dev_dbg(xpc_chan, "XPC_CHCTL_OPENREQUEST (entry_size=%d, "
<------><------><------>"local_nentries=%d) received from partid=%d, "
<------><------><------>"channel=%d\n", args->entry_size, args->local_nentries,
<------><------><------>ch->partid, ch->number);
 
<------><------>if (part->act_state == XPC_P_AS_DEACTIVATING ||
<------><------>    (ch->flags & XPC_C_ROPENREQUEST)) {
<------><------><------>goto out;
<------><------>}
 
<------><------>if (ch->flags & (XPC_C_DISCONNECTING | XPC_C_WDISCONNECT)) {
<------><------><------>ch->delayed_chctl_flags |= XPC_CHCTL_OPENREQUEST;
<------><------><------>goto out;
<------><------>}
<------><------>DBUG_ON(!(ch->flags & (XPC_C_DISCONNECTED |
<------><------><------><------>       XPC_C_OPENREQUEST)));
<------><------>DBUG_ON(ch->flags & (XPC_C_ROPENREQUEST | XPC_C_ROPENREPLY |
<------><------><------><------>     XPC_C_OPENREPLY | XPC_C_CONNECTED));
 
<------><------>/*
<------><------> * The meaningful OPENREQUEST connection state fields are:
<------><------> *      entry_size = size of channel's messages in bytes
<------><------> *      local_nentries = remote partition's local_nentries
<------><------> */
<------><------>if (args->entry_size == 0 || args->local_nentries == 0) {
<------><------><------>/* assume OPENREQUEST was delayed by mistake */
<------><------><------>goto out;
<------><------>}
 
<------><------>ch->flags |= (XPC_C_ROPENREQUEST | XPC_C_CONNECTING);
<------><------>ch->remote_nentries = args->local_nentries;
 
<------><------>if (ch->flags & XPC_C_OPENREQUEST) {
<------><------><------>if (args->entry_size != ch->entry_size) {
<------><------><------><------>XPC_DISCONNECT_CHANNEL(ch, xpUnequalMsgSizes,
<------><------><------><------><------><------>       &irq_flags);
<------><------><------><------>goto out;
<------><------><------>}
<------><------>} else {
<------><------><------>ch->entry_size = args->entry_size;
 
<------><------><------>XPC_SET_REASON(ch, 0, 0);
<------><------><------>ch->flags &= ~XPC_C_DISCONNECTED;
 
<------><------><------>atomic_inc(&part->nchannels_active);
<------><------>}
 
<------><------>xpc_process_connect(ch, &irq_flags);
<------>}
 
<------>if (chctl_flags & XPC_CHCTL_OPENREPLY) {
 
<------><------>dev_dbg(xpc_chan, "XPC_CHCTL_OPENREPLY (local_msgqueue_pa="
<------><------><------>"0x%lx, local_nentries=%d, remote_nentries=%d) "
<------><------><------>"received from partid=%d, channel=%d\n",
<------><------><------>args->local_msgqueue_pa, args->local_nentries,
<------><------><------>args->remote_nentries, ch->partid, ch->number);
 
<------><------>if (ch->flags & (XPC_C_DISCONNECTING | XPC_C_DISCONNECTED))
<------><------><------>goto out;
 
<------><------>if (!(ch->flags & XPC_C_OPENREQUEST)) {
<------><------><------>XPC_DISCONNECT_CHANNEL(ch, xpOpenCloseError,
<------><------><------><------><------>       &irq_flags);
<------><------><------>goto out;
<------><------>}
 
<------><------>DBUG_ON(!(ch->flags & XPC_C_ROPENREQUEST));
<------><------>DBUG_ON(ch->flags & XPC_C_CONNECTED);
 
<------><------>/*
<------><------> * The meaningful OPENREPLY connection state fields are:
<------><------> *      local_msgqueue_pa = physical address of remote
<------><------> *                          partition's local_msgqueue
<------><------> *      local_nentries = remote partition's local_nentries
<------><------> *      remote_nentries = remote partition's remote_nentries
<------><------> */
<------><------>DBUG_ON(args->local_msgqueue_pa == 0);
<------><------>DBUG_ON(args->local_nentries == 0);
<------><------>DBUG_ON(args->remote_nentries == 0);
 
<------><------>ret = xpc_arch_ops.save_remote_msgqueue_pa(ch,
<------><------><------><------><------><------>      args->local_msgqueue_pa);
<------><------>if (ret != xpSuccess) {
<------><------><------>XPC_DISCONNECT_CHANNEL(ch, ret, &irq_flags);
<------><------><------>goto out;
<------><------>}
<------><------>ch->flags |= XPC_C_ROPENREPLY;
 
<------><------>if (args->local_nentries < ch->remote_nentries) {
<------><------><------>dev_dbg(xpc_chan, "XPC_CHCTL_OPENREPLY: new "
<------><------><------><------>"remote_nentries=%d, old remote_nentries=%d, "
<------><------><------><------>"partid=%d, channel=%d\n",
<------><------><------><------>args->local_nentries, ch->remote_nentries,
<------><------><------><------>ch->partid, ch->number);
 
<------><------><------>ch->remote_nentries = args->local_nentries;
<------><------>}
<------><------>if (args->remote_nentries < ch->local_nentries) {
<------><------><------>dev_dbg(xpc_chan, "XPC_CHCTL_OPENREPLY: new "
<------><------><------><------>"local_nentries=%d, old local_nentries=%d, "
<------><------><------><------>"partid=%d, channel=%d\n",
<------><------><------><------>args->remote_nentries, ch->local_nentries,
<------><------><------><------>ch->partid, ch->number);
 
<------><------><------>ch->local_nentries = args->remote_nentries;
<------><------>}
 
<------><------>xpc_process_connect(ch, &irq_flags);
<------>}
 
<------>if (chctl_flags & XPC_CHCTL_OPENCOMPLETE) {
 
<------><------>dev_dbg(xpc_chan, "XPC_CHCTL_OPENCOMPLETE received from "
<------><------><------>"partid=%d, channel=%d\n", ch->partid, ch->number);
 
<------><------>if (ch->flags & (XPC_C_DISCONNECTING | XPC_C_DISCONNECTED))
<------><------><------>goto out;
 
<------><------>if (!(ch->flags & XPC_C_OPENREQUEST) ||
<------><------>    !(ch->flags & XPC_C_OPENREPLY)) {
<------><------><------>XPC_DISCONNECT_CHANNEL(ch, xpOpenCloseError,
<------><------><------><------><------>       &irq_flags);
<------><------><------>goto out;
<------><------>}
 
<------><------>DBUG_ON(!(ch->flags & XPC_C_ROPENREQUEST));
<------><------>DBUG_ON(!(ch->flags & XPC_C_ROPENREPLY));
<------><------>DBUG_ON(!(ch->flags & XPC_C_CONNECTED));
 
<------><------>ch->flags |= XPC_C_ROPENCOMPLETE;
 
<------><------>xpc_process_connect(ch, &irq_flags);
<------><------>create_kthread = 1;
<------>}
 
out:
<------>spin_unlock_irqrestore(&ch->lock, irq_flags);
 
<------>if (create_kthread)
<------><------>xpc_create_kthreads(ch, 1, 0);
}
 
/*
 * Attempt to establish a channel connection to a remote partition.
 */
static enum xp_retval
xpc_connect_channel(struct xpc_channel *ch)
{
<------>unsigned long irq_flags;
<------>struct xpc_registration *registration = &xpc_registrations[ch->number];
 
<------>if (mutex_trylock(&registration->mutex) == 0)
<------><------>return xpRetry;
 
<------>if (!XPC_CHANNEL_REGISTERED(ch->number)) {
<------><------>mutex_unlock(&registration->mutex);
<------><------>return xpUnregistered;
<------>}
 
<------>spin_lock_irqsave(&ch->lock, irq_flags);
 
<------>DBUG_ON(ch->flags & XPC_C_CONNECTED);
<------>DBUG_ON(ch->flags & XPC_C_OPENREQUEST);
 
<------>if (ch->flags & XPC_C_DISCONNECTING) {
<------><------>spin_unlock_irqrestore(&ch->lock, irq_flags);
<------><------>mutex_unlock(&registration->mutex);
<------><------>return ch->reason;
<------>}
 
<------>/* add info from the channel connect registration to the channel */
 
<------>ch->kthreads_assigned_limit = registration->assigned_limit;
<------>ch->kthreads_idle_limit = registration->idle_limit;
<------>DBUG_ON(atomic_read(&ch->kthreads_assigned) != 0);
<------>DBUG_ON(atomic_read(&ch->kthreads_idle) != 0);
<------>DBUG_ON(atomic_read(&ch->kthreads_active) != 0);
 
<------>ch->func = registration->func;
<------>DBUG_ON(registration->func == NULL);
<------>ch->key = registration->key;
 
<------>ch->local_nentries = registration->nentries;
 
<------>if (ch->flags & XPC_C_ROPENREQUEST) {
<------><------>if (registration->entry_size != ch->entry_size) {
<------><------><------>/* the local and remote sides aren't the same */
 
<------><------><------>/*
<------><------><------> * Because XPC_DISCONNECT_CHANNEL() can block we're
<------><------><------> * forced to up the registration sema before we unlock
<------><------><------> * the channel lock. But that's okay here because we're
<------><------><------> * done with the part that required the registration
<------><------><------> * sema. XPC_DISCONNECT_CHANNEL() requires that the
<------><------><------> * channel lock be locked and will unlock and relock
<------><------><------> * the channel lock as needed.
<------><------><------> */
<------><------><------>mutex_unlock(&registration->mutex);
<------><------><------>XPC_DISCONNECT_CHANNEL(ch, xpUnequalMsgSizes,
<------><------><------><------><------>       &irq_flags);
<------><------><------>spin_unlock_irqrestore(&ch->lock, irq_flags);
<------><------><------>return xpUnequalMsgSizes;
<------><------>}
<------>} else {
<------><------>ch->entry_size = registration->entry_size;
 
<------><------>XPC_SET_REASON(ch, 0, 0);
<------><------>ch->flags &= ~XPC_C_DISCONNECTED;
 
<------><------>atomic_inc(&xpc_partitions[ch->partid].nchannels_active);
<------>}
 
<------>mutex_unlock(&registration->mutex);
 
<------>/* initiate the connection */
 
<------>ch->flags |= (XPC_C_OPENREQUEST | XPC_C_CONNECTING);
<------>xpc_arch_ops.send_chctl_openrequest(ch, &irq_flags);
 
<------>xpc_process_connect(ch, &irq_flags);
 
<------>spin_unlock_irqrestore(&ch->lock, irq_flags);
 
<------>return xpSuccess;
}
 
void
xpc_process_sent_chctl_flags(struct xpc_partition *part)
{
<------>unsigned long irq_flags;
<------>union xpc_channel_ctl_flags chctl;
<------>struct xpc_channel *ch;
<------>int ch_number;
<------>u32 ch_flags;
 
<------>chctl.all_flags = xpc_arch_ops.get_chctl_all_flags(part);
 
<------>/*
<------> * Initiate channel connections for registered channels.
<------> *
<------> * For each connected channel that has pending messages activate idle
<------> * kthreads and/or create new kthreads as needed.
<------> */
 
<------>for (ch_number = 0; ch_number < part->nchannels; ch_number++) {
<------><------>ch = &part->channels[ch_number];
 
<------><------>/*
<------><------> * Process any open or close related chctl flags, and then deal
<------><------> * with connecting or disconnecting the channel as required.
<------><------> */
 
<------><------>if (chctl.flags[ch_number] & XPC_OPENCLOSE_CHCTL_FLAGS) {
<------><------><------>xpc_process_openclose_chctl_flags(part, ch_number,
<------><------><------><------><------><------><------>chctl.flags[ch_number]);
<------><------>}
 
<------><------>ch_flags = ch->flags;	/* need an atomic snapshot of flags */
 
<------><------>if (ch_flags & XPC_C_DISCONNECTING) {
<------><------><------>spin_lock_irqsave(&ch->lock, irq_flags);
<------><------><------>xpc_process_disconnect(ch, &irq_flags);
<------><------><------>spin_unlock_irqrestore(&ch->lock, irq_flags);
<------><------><------>continue;
<------><------>}
 
<------><------>if (part->act_state == XPC_P_AS_DEACTIVATING)
<------><------><------>continue;
 
<------><------>if (!(ch_flags & XPC_C_CONNECTED)) {
<------><------><------>if (!(ch_flags & XPC_C_OPENREQUEST)) {
<------><------><------><------>DBUG_ON(ch_flags & XPC_C_SETUP);
<------><------><------><------>(void)xpc_connect_channel(ch);
<------><------><------>}
<------><------><------>continue;
<------><------>}
 
<------><------>/*
<------><------> * Process any message related chctl flags, this may involve
<------><------> * the activation of kthreads to deliver any pending messages
<------><------> * sent from the other partition.
<------><------> */
 
<------><------>if (chctl.flags[ch_number] & XPC_MSG_CHCTL_FLAGS)
<------><------><------>xpc_arch_ops.process_msg_chctl_flags(part, ch_number);
<------>}
}
 
/*
 * XPC's heartbeat code calls this function to inform XPC that a partition is
 * going down.  XPC responds by tearing down the XPartition Communication
 * infrastructure used for the just downed partition.
 *
 * XPC's heartbeat code will never call this function and xpc_partition_up()
 * at the same time. Nor will it ever make multiple calls to either function
 * at the same time.
 */
void
xpc_partition_going_down(struct xpc_partition *part, enum xp_retval reason)
{
<------>unsigned long irq_flags;
<------>int ch_number;
<------>struct xpc_channel *ch;
 
<------>dev_dbg(xpc_chan, "deactivating partition %d, reason=%d\n",
<------><------>XPC_PARTID(part), reason);
 
<------>if (!xpc_part_ref(part)) {
<------><------>/* infrastructure for this partition isn't currently set up */
<------><------>return;
<------>}
 
<------>/* disconnect channels associated with the partition going down */
 
<------>for (ch_number = 0; ch_number < part->nchannels; ch_number++) {
<------><------>ch = &part->channels[ch_number];
 
<------><------>xpc_msgqueue_ref(ch);
<------><------>spin_lock_irqsave(&ch->lock, irq_flags);
 
<------><------>XPC_DISCONNECT_CHANNEL(ch, reason, &irq_flags);
 
<------><------>spin_unlock_irqrestore(&ch->lock, irq_flags);
<------><------>xpc_msgqueue_deref(ch);
<------>}
 
<------>xpc_wakeup_channel_mgr(part);
 
<------>xpc_part_deref(part);
}
 
/*
 * Called by XP at the time of channel connection registration to cause
 * XPC to establish connections to all currently active partitions.
 */
void
xpc_initiate_connect(int ch_number)
{
<------>short partid;
<------>struct xpc_partition *part;
 
<------>DBUG_ON(ch_number < 0 || ch_number >= XPC_MAX_NCHANNELS);
 
<------>for (partid = 0; partid < xp_max_npartitions; partid++) {
<------><------>part = &xpc_partitions[partid];
 
<------><------>if (xpc_part_ref(part)) {
<------><------><------>/*
<------><------><------> * Initiate the establishment of a connection on the
<------><------><------> * newly registered channel to the remote partition.
<------><------><------> */
<------><------><------>xpc_wakeup_channel_mgr(part);
<------><------><------>xpc_part_deref(part);
<------><------>}
<------>}
}
 
void
xpc_connected_callout(struct xpc_channel *ch)
{
<------>/* let the registerer know that a connection has been established */
 
<------>if (ch->func != NULL) {
<------><------>dev_dbg(xpc_chan, "ch->func() called, reason=xpConnected, "
<------><------><------>"partid=%d, channel=%d\n", ch->partid, ch->number);
 
<------><------>ch->func(xpConnected, ch->partid, ch->number,
<------><------><------> (void *)(u64)ch->local_nentries, ch->key);
 
<------><------>dev_dbg(xpc_chan, "ch->func() returned, reason=xpConnected, "
<------><------><------>"partid=%d, channel=%d\n", ch->partid, ch->number);
<------>}
}
 
/*
 * Called by XP at the time of channel connection unregistration to cause
 * XPC to teardown all current connections for the specified channel.
 *
 * Before returning xpc_initiate_disconnect() will wait until all connections
 * on the specified channel have been closed/torndown. So the caller can be
 * assured that they will not be receiving any more callouts from XPC to the
 * function they registered via xpc_connect().
 *
 * Arguments:
 *
 *	ch_number - channel # to unregister.
 */
void
xpc_initiate_disconnect(int ch_number)
{
<------>unsigned long irq_flags;
<------>short partid;
<------>struct xpc_partition *part;
<------>struct xpc_channel *ch;
 
<------>DBUG_ON(ch_number < 0 || ch_number >= XPC_MAX_NCHANNELS);
 
<------>/* initiate the channel disconnect for every active partition */
<------>for (partid = 0; partid < xp_max_npartitions; partid++) {
<------><------>part = &xpc_partitions[partid];
 
<------><------>if (xpc_part_ref(part)) {
<------><------><------>ch = &part->channels[ch_number];
<------><------><------>xpc_msgqueue_ref(ch);
 
<------><------><------>spin_lock_irqsave(&ch->lock, irq_flags);
 
<------><------><------>if (!(ch->flags & XPC_C_DISCONNECTED)) {
<------><------><------><------>ch->flags |= XPC_C_WDISCONNECT;
 
<------><------><------><------>XPC_DISCONNECT_CHANNEL(ch, xpUnregistering,
<------><------><------><------><------><------>       &irq_flags);
<------><------><------>}
 
<------><------><------>spin_unlock_irqrestore(&ch->lock, irq_flags);
 
<------><------><------>xpc_msgqueue_deref(ch);
<------><------><------>xpc_part_deref(part);
<------><------>}
<------>}
 
<------>xpc_disconnect_wait(ch_number);
}
 
/*
 * To disconnect a channel, and reflect it back to all who may be waiting.
 *
 * An OPEN is not allowed until XPC_C_DISCONNECTING is cleared by
 * xpc_process_disconnect(), and if set, XPC_C_WDISCONNECT is cleared by
 * xpc_disconnect_wait().
 *
 * THE CHANNEL IS TO BE LOCKED BY THE CALLER AND WILL REMAIN LOCKED UPON RETURN.
 */
void
xpc_disconnect_channel(const int line, struct xpc_channel *ch,
<------><------>       enum xp_retval reason, unsigned long *irq_flags)
{
<------>u32 channel_was_connected = (ch->flags & XPC_C_CONNECTED);
 
<------>lockdep_assert_held(&ch->lock);
 
<------>if (ch->flags & (XPC_C_DISCONNECTING | XPC_C_DISCONNECTED))
<------><------>return;
 
<------>DBUG_ON(!(ch->flags & (XPC_C_CONNECTING | XPC_C_CONNECTED)));
 
<------>dev_dbg(xpc_chan, "reason=%d, line=%d, partid=%d, channel=%d\n",
<------><------>reason, line, ch->partid, ch->number);
 
<------>XPC_SET_REASON(ch, reason, line);
 
<------>ch->flags |= (XPC_C_CLOSEREQUEST | XPC_C_DISCONNECTING);
<------>/* some of these may not have been set */
<------>ch->flags &= ~(XPC_C_OPENREQUEST | XPC_C_OPENREPLY |
<------><------>       XPC_C_ROPENREQUEST | XPC_C_ROPENREPLY |
<------><------>       XPC_C_CONNECTING | XPC_C_CONNECTED);
 
<------>xpc_arch_ops.send_chctl_closerequest(ch, irq_flags);
 
<------>if (channel_was_connected)
<------><------>ch->flags |= XPC_C_WASCONNECTED;
 
<------>spin_unlock_irqrestore(&ch->lock, *irq_flags);
 
<------>/* wake all idle kthreads so they can exit */
<------>if (atomic_read(&ch->kthreads_idle) > 0) {
<------><------>wake_up_all(&ch->idle_wq);
 
<------>} else if ((ch->flags & XPC_C_CONNECTEDCALLOUT_MADE) &&
<------><------>   !(ch->flags & XPC_C_DISCONNECTINGCALLOUT)) {
<------><------>/* start a kthread that will do the xpDisconnecting callout */
<------><------>xpc_create_kthreads(ch, 1, 1);
<------>}
 
<------>/* wake those waiting to allocate an entry from the local msg queue */
<------>if (atomic_read(&ch->n_on_msg_allocate_wq) > 0)
<------><------>wake_up(&ch->msg_allocate_wq);
 
<------>spin_lock_irqsave(&ch->lock, *irq_flags);
}
 
void
xpc_disconnect_callout(struct xpc_channel *ch, enum xp_retval reason)
{
<------>/*
<------> * Let the channel's registerer know that the channel is being
<------> * disconnected. We don't want to do this if the registerer was never
<------> * informed of a connection being made.
<------> */
 
<------>if (ch->func != NULL) {
<------><------>dev_dbg(xpc_chan, "ch->func() called, reason=%d, partid=%d, "
<------><------><------>"channel=%d\n", reason, ch->partid, ch->number);
 
<------><------>ch->func(reason, ch->partid, ch->number, NULL, ch->key);
 
<------><------>dev_dbg(xpc_chan, "ch->func() returned, reason=%d, partid=%d, "
<------><------><------>"channel=%d\n", reason, ch->partid, ch->number);
<------>}
}
 
/*
 * Wait for a message entry to become available for the specified channel,
 * but don't wait any longer than 1 jiffy.
 */
enum xp_retval
xpc_allocate_msg_wait(struct xpc_channel *ch)
{
<------>enum xp_retval ret;
<------>DEFINE_WAIT(wait);
 
<------>if (ch->flags & XPC_C_DISCONNECTING) {
<------><------>DBUG_ON(ch->reason == xpInterrupted);
<------><------>return ch->reason;
<------>}
 
<------>atomic_inc(&ch->n_on_msg_allocate_wq);
<------>prepare_to_wait(&ch->msg_allocate_wq, &wait, TASK_INTERRUPTIBLE);
<------>ret = schedule_timeout(1);
<------>finish_wait(&ch->msg_allocate_wq, &wait);
<------>atomic_dec(&ch->n_on_msg_allocate_wq);
 
<------>if (ch->flags & XPC_C_DISCONNECTING) {
<------><------>ret = ch->reason;
<------><------>DBUG_ON(ch->reason == xpInterrupted);
<------>} else if (ret == 0) {
<------><------>ret = xpTimeout;
<------>} else {
<------><------>ret = xpInterrupted;
<------>}
 
<------>return ret;
}
 
/*
 * Send a message that contains the user's payload on the specified channel
 * connected to the specified partition.
 *
 * NOTE that this routine can sleep waiting for a message entry to become
 * available. To not sleep, pass in the XPC_NOWAIT flag.
 *
 * Once sent, this routine will not wait for the message to be received, nor
 * will notification be given when it does happen.
 *
 * Arguments:
 *
 *	partid - ID of partition to which the channel is connected.
 *	ch_number - channel # to send message on.
 *	flags - see xp.h for valid flags.
 *	payload - pointer to the payload which is to be sent.
 *	payload_size - size of the payload in bytes.
 */
enum xp_retval
xpc_initiate_send(short partid, int ch_number, u32 flags, void *payload,
<------><------>  u16 payload_size)
{
<------>struct xpc_partition *part = &xpc_partitions[partid];
<------>enum xp_retval ret = xpUnknownReason;
 
<------>dev_dbg(xpc_chan, "payload=0x%p, partid=%d, channel=%d\n", payload,
<------><------>partid, ch_number);
 
<------>DBUG_ON(partid < 0 || partid >= xp_max_npartitions);
<------>DBUG_ON(ch_number < 0 || ch_number >= part->nchannels);
<------>DBUG_ON(payload == NULL);
 
<------>if (xpc_part_ref(part)) {
<------><------>ret = xpc_arch_ops.send_payload(&part->channels[ch_number],
<------><------><------><------>  flags, payload, payload_size, 0, NULL, NULL);
<------><------>xpc_part_deref(part);
<------>}
 
<------>return ret;
}
 
/*
 * Send a message that contains the user's payload on the specified channel
 * connected to the specified partition.
 *
 * NOTE that this routine can sleep waiting for a message entry to become
 * available. To not sleep, pass in the XPC_NOWAIT flag.
 *
 * This routine will not wait for the message to be sent or received.
 *
 * Once the remote end of the channel has received the message, the function
 * passed as an argument to xpc_initiate_send_notify() will be called. This
 * allows the sender to free up or re-use any buffers referenced by the
 * message, but does NOT mean the message has been processed at the remote
 * end by a receiver.
 *
 * If this routine returns an error, the caller's function will NOT be called.
 *
 * Arguments:
 *
 *	partid - ID of partition to which the channel is connected.
 *	ch_number - channel # to send message on.
 *	flags - see xp.h for valid flags.
 *	payload - pointer to the payload which is to be sent.
 *	payload_size - size of the payload in bytes.
 *	func - function to call with asynchronous notification of message
 *		  receipt. THIS FUNCTION MUST BE NON-BLOCKING.
 *	key - user-defined key to be passed to the function when it's called.
 */
enum xp_retval
xpc_initiate_send_notify(short partid, int ch_number, u32 flags, void *payload,
<------><------><------> u16 payload_size, xpc_notify_func func, void *key)
{
<------>struct xpc_partition *part = &xpc_partitions[partid];
<------>enum xp_retval ret = xpUnknownReason;
 
<------>dev_dbg(xpc_chan, "payload=0x%p, partid=%d, channel=%d\n", payload,
<------><------>partid, ch_number);
 
<------>DBUG_ON(partid < 0 || partid >= xp_max_npartitions);
<------>DBUG_ON(ch_number < 0 || ch_number >= part->nchannels);
<------>DBUG_ON(payload == NULL);
<------>DBUG_ON(func == NULL);
 
<------>if (xpc_part_ref(part)) {
<------><------>ret = xpc_arch_ops.send_payload(&part->channels[ch_number],
<------><------><------>  flags, payload, payload_size, XPC_N_CALL, func, key);
<------><------>xpc_part_deref(part);
<------>}
<------>return ret;
}
 
/*
 * Deliver a message's payload to its intended recipient.
 */
void
xpc_deliver_payload(struct xpc_channel *ch)
{
<------>void *payload;
 
<------>payload = xpc_arch_ops.get_deliverable_payload(ch);
<------>if (payload != NULL) {
 
<------><------>/*
<------><------> * This ref is taken to protect the payload itself from being
<------><------> * freed before the user is finished with it, which the user
<------><------> * indicates by calling xpc_initiate_received().
<------><------> */
<------><------>xpc_msgqueue_ref(ch);
 
<------><------>atomic_inc(&ch->kthreads_active);
 
<------><------>if (ch->func != NULL) {
<------><------><------>dev_dbg(xpc_chan, "ch->func() called, payload=0x%p "
<------><------><------><------>"partid=%d channel=%d\n", payload, ch->partid,
<------><------><------><------>ch->number);
 
<------><------><------>/* deliver the message to its intended recipient */
<------><------><------>ch->func(xpMsgReceived, ch->partid, ch->number, payload,
<------><------><------><------> ch->key);
 
<------><------><------>dev_dbg(xpc_chan, "ch->func() returned, payload=0x%p "
<------><------><------><------>"partid=%d channel=%d\n", payload, ch->partid,
<------><------><------><------>ch->number);
<------><------>}
 
<------><------>atomic_dec(&ch->kthreads_active);
<------>}
}
 
/*
 * Acknowledge receipt of a delivered message's payload.
 *
 * This function, although called by users, does not call xpc_part_ref() to
 * ensure that the partition infrastructure is in place. It relies on the
 * fact that we called xpc_msgqueue_ref() in xpc_deliver_payload().
 *
 * Arguments:
 *
 *	partid - ID of partition to which the channel is connected.
 *	ch_number - channel # message received on.
 *	payload - pointer to the payload area allocated via
 *			xpc_initiate_send() or xpc_initiate_send_notify().
 */
void
xpc_initiate_received(short partid, int ch_number, void *payload)
{
<------>struct xpc_partition *part = &xpc_partitions[partid];
<------>struct xpc_channel *ch;
 
<------>DBUG_ON(partid < 0 || partid >= xp_max_npartitions);
<------>DBUG_ON(ch_number < 0 || ch_number >= part->nchannels);
 
<------>ch = &part->channels[ch_number];
<------>xpc_arch_ops.received_payload(ch, payload);
 
<------>/* the call to xpc_msgqueue_ref() was done by xpc_deliver_payload()  */
<------>xpc_msgqueue_deref(ch);
}