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1011 lines
28 KiB
1011 lines
28 KiB
/* |
|
* 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. |
|
* |
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* 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. |
|
* |
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* 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); |
|
|
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if (ret != xpSuccess) |
|
XPC_DISCONNECT_CHANNEL(ch, ret, irq_flags); |
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else |
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ch->flags |= XPC_C_SETUP; |
|
|
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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); |
|
} |
|
|
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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); |
|
|
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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); |
|
}
|
|
|