sgi-xp: isolate xpc_vars structure to sn2 only

Isolate the xpc_vars structure of XPC's reserved page to sn2 only.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 313 deletions

diff --git a/drivers/misc/sgi-xp/xpc_channel.c b/drivers/misc/sgi-xp/xpc_channel.c
index 8081e8155dff..26c5e12c1220 100644
--- a/drivers/misc/sgi-xp/xpc_channel.c
+++ b/drivers/misc/sgi-xp/xpc_channel.c
@@ -1165,7 +1165,7 @@ xpc_disconnect_callout(struct xpc_channel *ch, enum xp_retval reason)
  * Wait for a message entry to become available for the specified channel,
  * but don't wait any longer than 1 jiffy.
  */
-static enum xp_retval
+enum xp_retval
 xpc_allocate_msg_wait(struct xpc_channel *ch)
 {
         enum xp_retval ret;
@@ -1193,96 +1193,6 @@ xpc_allocate_msg_wait(struct xpc_channel *ch)
 
 /*
  * Allocate an entry for a message from the message queue associated with the
- * specified channel.
- */
-static enum xp_retval
-xpc_allocate_msg(struct xpc_channel *ch, u32 flags,
-                 struct xpc_msg **address_of_msg)
-{
-        struct xpc_msg *msg;
-        enum xp_retval ret;
-        s64 put;
-
-        /* this reference will be dropped in xpc_send_msg() */
-        xpc_msgqueue_ref(ch);
-
-        if (ch->flags & XPC_C_DISCONNECTING) {
-                xpc_msgqueue_deref(ch);
-                return ch->reason;
-        }
-        if (!(ch->flags & XPC_C_CONNECTED)) {
-                xpc_msgqueue_deref(ch);
-                return xpNotConnected;
-        }
-
-        /*
-         * Get the next available message entry from the local message queue.
-         * If none are available, we'll make sure that we grab the latest
-         * GP values.
-         */
-        ret = xpTimeout;
-
-        while (1) {
-
-                put = ch->w_local_GP.put;
-                rmb();  /* guarantee that .put loads before .get */
-                if (put - ch->w_remote_GP.get < ch->local_nentries) {
-
-                        /* There are available message entries. We need to try
-                         * to secure one for ourselves. We'll do this by trying
-                         * to increment w_local_GP.put as long as someone else
-                         * doesn't beat us to it. If they do, we'll have to
-                         * try again.
-                         */
-                        if (cmpxchg(&ch->w_local_GP.put, put, put + 1) == put) {
-                                /* we got the entry referenced by put */
-                                break;
-                        }
-                        continue;       /* try again */
-                }
-
-                /*
-                 * There aren't any available msg entries at this time.
-                 *
-                 * In waiting for a message entry to become available,
-                 * we set a timeout in case the other side is not
-                 * sending completion IPIs. This lets us fake an IPI
-                 * that will cause the IPI handler to fetch the latest
-                 * GP values as if an IPI was sent by the other side.
-                 */
-                if (ret == xpTimeout)
-                        xpc_IPI_send_local_msgrequest(ch);
-
-                if (flags & XPC_NOWAIT) {
-                        xpc_msgqueue_deref(ch);
-                        return xpNoWait;
-                }
-
-                ret = xpc_allocate_msg_wait(ch);
-                if (ret != xpInterrupted && ret != xpTimeout) {
-                        xpc_msgqueue_deref(ch);
-                        return ret;
-                }
-        }
-
-        /* get the message's address and initialize it */
-        msg = (struct xpc_msg *)((u64)ch->local_msgqueue +
-                                 (put % ch->local_nentries) * ch->msg_size);
-
-        DBUG_ON(msg->flags != 0);
-        msg->number = put;
-
-        dev_dbg(xpc_chan, "w_local_GP.put changed to %ld; msg=0x%p, "
-                "msg_number=%ld, partid=%d, channel=%d\n", put + 1,
-                (void *)msg, msg->number, ch->partid, ch->number);
-
-        *address_of_msg = msg;
-
-        return xpSuccess;
-}
-
-/*
- * Allocate an entry for a message from the message queue associated with the
  * specified channel. NOTE that this routine can sleep waiting for a message
  * entry to become available. To not sleep, pass in the XPC_NOWAIT flag.
  *
@@ -1318,144 +1228,6 @@ xpc_initiate_allocate(short partid, int ch_number, u32 flags, void **payload)
 }
 
 /*
- * Now we actually send the messages that are ready to be sent by advancing
- * the local message queue's Put value and then send an IPI to the recipient
- * partition.
- */
-static void
-xpc_send_msgs(struct xpc_channel *ch, s64 initial_put)
-{
-        struct xpc_msg *msg;
-        s64 put = initial_put + 1;
-        int send_IPI = 0;
-
-        while (1) {
-
-                while (1) {
-                        if (put == ch->w_local_GP.put)
-                                break;
-
-                        msg = (struct xpc_msg *)((u64)ch->local_msgqueue +
-                                                 (put % ch->local_nentries) *
-                                                 ch->msg_size);
-
-                        if (!(msg->flags & XPC_M_READY))
-                                break;
-
-                        put++;
-                }
-
-                if (put == initial_put) {
-                        /* nothing's changed */
-                        break;
-                }
-
-                if (cmpxchg_rel(&ch->local_GP->put, initial_put, put) !=
-                    initial_put) {
-                        /* someone else beat us to it */
-                        DBUG_ON(ch->local_GP->put < initial_put);
-                        break;
-                }
-
-                /* we just set the new value of local_GP->put */
-
-                dev_dbg(xpc_chan, "local_GP->put changed to %ld, partid=%d, "
-                        "channel=%d\n", put, ch->partid, ch->number);
-
-                send_IPI = 1;
-
-                /*
-                 * We need to ensure that the message referenced by
-                 * local_GP->put is not XPC_M_READY or that local_GP->put
-                 * equals w_local_GP.put, so we'll go have a look.
-                 */
-                initial_put = put;
-        }
-
-        if (send_IPI)
-                xpc_IPI_send_msgrequest(ch);
-}
-
-/*
- * Common code that does the actual sending of the message by advancing the
- * local message queue's Put value and sends an IPI to the partition the
- * message is being sent to.
- */
-static enum xp_retval
-xpc_send_msg(struct xpc_channel *ch, struct xpc_msg *msg, u8 notify_type,
-             xpc_notify_func func, void *key)
-{
-        enum xp_retval ret = xpSuccess;
-        struct xpc_notify *notify = notify;
-        s64 put, msg_number = msg->number;
-
-        DBUG_ON(notify_type == XPC_N_CALL && func == NULL);
-        DBUG_ON((((u64)msg - (u64)ch->local_msgqueue) / ch->msg_size) !=
-                msg_number % ch->local_nentries);
-        DBUG_ON(msg->flags & XPC_M_READY);
-
-        if (ch->flags & XPC_C_DISCONNECTING) {
-                /* drop the reference grabbed in xpc_allocate_msg() */
-                xpc_msgqueue_deref(ch);
-                return ch->reason;
-        }
-
-        if (notify_type != 0) {
-                /*
-                 * Tell the remote side to send an ACK interrupt when the
-                 * message has been delivered.
-                 */
-                msg->flags |= XPC_M_INTERRUPT;
-
-                atomic_inc(&ch->n_to_notify);
-
-                notify = &ch->notify_queue[msg_number % ch->local_nentries];
-                notify->func = func;
-                notify->key = key;
-                notify->type = notify_type;
-
-                /* >>> is a mb() needed here? */
-
-                if (ch->flags & XPC_C_DISCONNECTING) {
-                        /*
-                         * An error occurred between our last error check and
-                         * this one. We will try to clear the type field from
-                         * the notify entry. If we succeed then
-                         * xpc_disconnect_channel() didn't already process
-                         * the notify entry.
-                         */
-                        if (cmpxchg(&notify->type, notify_type, 0) ==
-                            notify_type) {
-                                atomic_dec(&ch->n_to_notify);
-                                ret = ch->reason;
-                        }
-
-                        /* drop the reference grabbed in xpc_allocate_msg() */
-                        xpc_msgqueue_deref(ch);
-                        return ret;
-                }
-        }
-
-        msg->flags |= XPC_M_READY;
-
-        /*
-         * The preceding store of msg->flags must occur before the following
-         * load of ch->local_GP->put.
-         */
-        mb();
-
-        /* see if the message is next in line to be sent, if so send it */
-
-        put = ch->local_GP->put;
-        if (put == msg_number)
-                xpc_send_msgs(ch, put);
-
-        /* drop the reference grabbed in xpc_allocate_msg() */
-        xpc_msgqueue_deref(ch);
-        return ret;
-}
-
-/*
  * Send a message previously allocated using xpc_initiate_allocate() on the
  * specified channel connected to the specified partition.
  *
@@ -1586,66 +1358,6 @@ xpc_deliver_msg(struct xpc_channel *ch)
 }
 
 /*
- * Now we actually acknowledge the messages that have been delivered and ack'd
- * by advancing the cached remote message queue's Get value and if requested
- * send an IPI to the message sender's partition.
- */
-static void
-xpc_acknowledge_msgs(struct xpc_channel *ch, s64 initial_get, u8 msg_flags)
-{
-        struct xpc_msg *msg;
-        s64 get = initial_get + 1;
-        int send_IPI = 0;
-
-        while (1) {
-
-                while (1) {
-                        if (get == ch->w_local_GP.get)
-                                break;
-
-                        msg = (struct xpc_msg *)((u64)ch->remote_msgqueue +
-                                                 (get % ch->remote_nentries) *
-                                                 ch->msg_size);
-
-                        if (!(msg->flags & XPC_M_DONE))
-                                break;
-
-                        msg_flags |= msg->flags;
-                        get++;
-                }
-
-                if (get == initial_get) {
-                        /* nothing's changed */
-                        break;
-                }
-
-                if (cmpxchg_rel(&ch->local_GP->get, initial_get, get) !=
-                    initial_get) {
-                        /* someone else beat us to it */
-                        DBUG_ON(ch->local_GP->get <= initial_get);
-                        break;
-                }
-
-                /* we just set the new value of local_GP->get */
-
-                dev_dbg(xpc_chan, "local_GP->get changed to %ld, partid=%d, "
-                        "channel=%d\n", get, ch->partid, ch->number);
-
-                send_IPI = (msg_flags & XPC_M_INTERRUPT);
-
-                /*
-                 * We need to ensure that the message referenced by
-                 * local_GP->get is not XPC_M_DONE or that local_GP->get
-                 * equals w_local_GP.get, so we'll go have a look.
-                 */
-                initial_get = get;
-        }
-
-        if (send_IPI)
-                xpc_IPI_send_msgrequest(ch);
-}
-
-/*
  * Acknowledge receipt of a delivered message.
  *
  * If a message has XPC_M_INTERRUPT set, send an interrupt to the partition
@@ -1668,35 +1380,12 @@ xpc_initiate_received(short partid, int ch_number, void *payload)
         struct xpc_partition *part = &xpc_partitions[partid];
         struct xpc_channel *ch;
         struct xpc_msg *msg = XPC_MSG_ADDRESS(payload);
-        s64 get, msg_number = msg->number;
 
         DBUG_ON(partid < 0 || partid >= xp_max_npartitions);
         DBUG_ON(ch_number < 0 || ch_number >= part->nchannels);
 
         ch = &part->channels[ch_number];
-
-        dev_dbg(xpc_chan, "msg=0x%p, msg_number=%ld, partid=%d, channel=%d\n",
-                (void *)msg, msg_number, ch->partid, ch->number);
-
-        DBUG_ON((((u64)msg - (u64)ch->remote_msgqueue) / ch->msg_size) !=
-                msg_number % ch->remote_nentries);
-        DBUG_ON(msg->flags & XPC_M_DONE);
-
-        msg->flags |= XPC_M_DONE;
-
-        /*
-         * The preceding store of msg->flags must occur before the following
-         * load of ch->local_GP->get.
-         */
-        mb();
-
-        /*
-         * See if this message is next in line to be acknowledged as having
-         * been delivered.
-         */
-        get = ch->local_GP->get;
-        if (get == msg_number)
-                xpc_acknowledge_msgs(ch, get, msg->flags);
+        xpc_received_msg(ch, msg);
 
         /* the call to xpc_msgqueue_ref() was done by xpc_deliver_msg()  */
         xpc_msgqueue_deref(ch);