[IA64-SGI] fixes for XPC disengage and open/close protocol

[deliverable/linux.git] / arch / ia64 / sn / kernel / xpc_channel.c

diff --git a/arch/ia64/sn/kernel/xpc_channel.c b/arch/ia64/sn/kernel/xpc_channel.c
index 195ac1b8e2620e06c06d9cc89f7e3c50a689c35f..abf4fc2a87bba20e98014172412be96f84c92f91 100644 (file)
--- a/arch/ia64/sn/kernel/xpc_channel.c
+++ b/arch/ia64/sn/kernel/xpc_channel.c
@@ -792,11 +792,20 @@ xpc_process_disconnect(struct xpc_channel *ch, unsigned long *irq_flags)
                        "reason=%d\n", ch->number, ch->partid, ch->reason);
        }
 
-       /* wake the thread that is waiting for this channel to disconnect */
        if (ch->flags & XPC_C_WDISCONNECT) {
                spin_unlock_irqrestore(&ch->lock, *irq_flags);
                up(&ch->wdisconnect_sema);
                spin_lock_irqsave(&ch->lock, *irq_flags);
+
+       } else if (ch->delayed_IPI_flags) {
+               if (part->act_state != XPC_P_DEACTIVATING) {
+                       /* time to take action on any delayed IPI flags */
+                       spin_lock(&part->IPI_lock);
+                       XPC_SET_IPI_FLAGS(part->local_IPI_amo, ch->number,
+                                                       ch->delayed_IPI_flags);
+                       spin_unlock(&part->IPI_lock);
+               }
+               ch->delayed_IPI_flags = 0;
        }
 }
 
@@ -818,6 +827,19 @@ xpc_process_openclose_IPI(struct xpc_partition *part, int ch_number,
 
        spin_lock_irqsave(&ch->lock, irq_flags);
 
+again:
+
+       if ((ch->flags & XPC_C_DISCONNECTED) &&
+                                       (ch->flags & XPC_C_WDISCONNECT)) {
+               /*
+                * Delay processing IPI flags until thread waiting disconnect
+                * has had a chance to see that the channel is disconnected.
+                */
+               ch->delayed_IPI_flags |= IPI_flags;
+               spin_unlock_irqrestore(&ch->lock, irq_flags);
+               return;
+       }
+
 
        if (IPI_flags & XPC_IPI_CLOSEREQUEST) {
 
@@ -843,14 +865,22 @@ xpc_process_openclose_IPI(struct xpc_partition *part, int ch_number,
 
                        /* 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) {
-                       // >>> explain this section
-
                        if (!(IPI_flags & XPC_IPI_OPENREQUEST)) {
-                               DBUG_ON(part->act_state !=
-                                                       XPC_P_DEACTIVATING);
+                               if ((XPC_GET_IPI_FLAGS(part->local_IPI_amo,
+                                        ch_number) & XPC_IPI_OPENREQUEST)) {
+
+                                       DBUG_ON(ch->delayed_IPI_flags != 0);
+                                       spin_lock(&part->IPI_lock);
+                                       XPC_SET_IPI_FLAGS(part->local_IPI_amo,
+                                                       ch_number,
+                                                       XPC_IPI_CLOSEREQUEST);
+                                       spin_unlock(&part->IPI_lock);
+                               }
                                spin_unlock_irqrestore(&ch->lock, irq_flags);
                                return;
                        }
@@ -880,9 +910,13 @@ xpc_process_openclose_IPI(struct xpc_partition *part, int ch_number,
                        }
 
                        XPC_DISCONNECT_CHANNEL(ch, reason, &irq_flags);
-               } else {
-                       xpc_process_disconnect(ch, &irq_flags);
+
+                       DBUG_ON(IPI_flags & XPC_IPI_CLOSEREPLY);
+                       spin_unlock_irqrestore(&ch->lock, irq_flags);
+                       return;
                }
+
+               xpc_process_disconnect(ch, &irq_flags);
        }
 
 
@@ -898,7 +932,20 @@ xpc_process_openclose_IPI(struct xpc_partition *part, int ch_number,
                }
 
                DBUG_ON(!(ch->flags & XPC_C_CLOSEREQUEST));
-               DBUG_ON(!(ch->flags & XPC_C_RCLOSEREQUEST));
+
+               if (!(ch->flags & XPC_C_RCLOSEREQUEST)) {
+                       if ((XPC_GET_IPI_FLAGS(part->local_IPI_amo, ch_number)
+                                               & XPC_IPI_CLOSEREQUEST)) {
+
+                               DBUG_ON(ch->delayed_IPI_flags != 0);
+                               spin_lock(&part->IPI_lock);
+                               XPC_SET_IPI_FLAGS(part->local_IPI_amo,
+                                               ch_number, XPC_IPI_CLOSEREPLY);
+                               spin_unlock(&part->IPI_lock);
+                       }
+                       spin_unlock_irqrestore(&ch->lock, irq_flags);
+                       return;
+               }
 
                ch->flags |= XPC_C_RCLOSEREPLY;
 
@@ -916,8 +963,14 @@ xpc_process_openclose_IPI(struct xpc_partition *part, int ch_number,
                        "channel=%d\n", args->msg_size, args->local_nentries,
                        ch->partid, ch->number);
 
-               if ((ch->flags & (XPC_C_DISCONNECTING | XPC_C_WDISCONNECT)) ||
-                                       part->act_state == XPC_P_DEACTIVATING) {
+               if (part->act_state == XPC_P_DEACTIVATING ||
+                                       (ch->flags & XPC_C_ROPENREQUEST)) {
+                       spin_unlock_irqrestore(&ch->lock, irq_flags);
+                       return;
+               }
+
+               if (ch->flags & (XPC_C_DISCONNECTING | XPC_C_WDISCONNECT)) {
+                       ch->delayed_IPI_flags |= XPC_IPI_OPENREQUEST;
                        spin_unlock_irqrestore(&ch->lock, irq_flags);
                        return;
                }
@@ -931,8 +984,11 @@ xpc_process_openclose_IPI(struct xpc_partition *part, int ch_number,
                 *      msg_size = size of channel's messages in bytes
                 *      local_nentries = remote partition's local_nentries
                 */
-               DBUG_ON(args->msg_size == 0);
-               DBUG_ON(args->local_nentries == 0);
+               if (args->msg_size == 0 || args->local_nentries == 0) {
+                       /* assume OPENREQUEST was delayed by mistake */
+                       spin_unlock_irqrestore(&ch->lock, irq_flags);
+                       return;
+               }
 
                ch->flags |= (XPC_C_ROPENREQUEST | XPC_C_CONNECTING);
                ch->remote_nentries = args->local_nentries;
@@ -970,7 +1026,13 @@ xpc_process_openclose_IPI(struct xpc_partition *part, int ch_number,
                        spin_unlock_irqrestore(&ch->lock, irq_flags);
                        return;
                }
-               DBUG_ON(!(ch->flags & XPC_C_OPENREQUEST));
+               if (!(ch->flags & XPC_C_OPENREQUEST)) {
+                       XPC_DISCONNECT_CHANNEL(ch, xpcOpenCloseError,
+                                                               &irq_flags);
+                       spin_unlock_irqrestore(&ch->lock, irq_flags);
+                       return;
+               }
+
                DBUG_ON(!(ch->flags & XPC_C_ROPENREQUEST));
                DBUG_ON(ch->flags & XPC_C_CONNECTED);
 
@@ -1024,8 +1086,8 @@ xpc_connect_channel(struct xpc_channel *ch)
        struct xpc_registration *registration = &xpc_registrations[ch->number];
 
 
-       if (down_interruptible(&registration->sema) != 0) {
-               return xpcInterrupted;
+       if (down_trylock(&registration->sema) != 0) {
+               return xpcRetry;
        }
 
        if (!XPC_CHANNEL_REGISTERED(ch->number)) {
@@ -1445,19 +1507,11 @@ xpc_initiate_connect(int ch_number)
                if (xpc_part_ref(part)) {
                        ch = &part->channels[ch_number];
 
-                       if (!(ch->flags & XPC_C_DISCONNECTING)) {
-                               DBUG_ON(ch->flags & XPC_C_OPENREQUEST);
-                               DBUG_ON(ch->flags & XPC_C_CONNECTED);
-                               DBUG_ON(ch->flags & XPC_C_SETUP);
-
-                               /*
-                                * Initiate the establishment of a connection
-                                * on the newly registered channel to the
-                                * remote partition.
-                                */
-                               xpc_wakeup_channel_mgr(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);
                }
        }
@@ -1467,9 +1521,6 @@ xpc_initiate_connect(int ch_number)
 void
 xpc_connected_callout(struct xpc_channel *ch)
 {
-       unsigned long irq_flags;
-
-
        /* let the registerer know that a connection has been established */
 
        if (ch->func != NULL) {
@@ -1482,10 +1533,6 @@ xpc_connected_callout(struct xpc_channel *ch)
                dev_dbg(xpc_chan, "ch->func() returned, reason=xpcConnected, "
                        "partid=%d, channel=%d\n", ch->partid, ch->number);
        }
-
-       spin_lock_irqsave(&ch->lock, irq_flags);
-       ch->flags |= XPC_C_CONNECTCALLOUT;
-       spin_unlock_irqrestore(&ch->lock, irq_flags);
 }