/*
* 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(®istration->mutex) == 0)
return xpRetry;
if (!XPC_CHANNEL_REGISTERED(ch->number)) {
mutex_unlock(®istration->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(®istration->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(®istration->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(®istration->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);
}
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