sgi-xp: setup the notify GRU message queue

Setup the notify GRU message queue that is used for sending user messages
on UV systems.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Cc: Jack Steiner <steiner@sgi.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

8 files changed, 1032 insertions, 384 deletions

diff --git a/drivers/misc/sgi-xp/xp.h b/drivers/misc/sgi-xp/xp.h
index 9ac5758f4d0..859a5281c61 100644
--- a/drivers/misc/sgi-xp/xp.h
+++ b/drivers/misc/sgi-xp/xp.h
@@ -87,39 +87,18 @@
 #endif
 
 /*
- * The format of an XPC message is as follows:
- *
- *      +-------+--------------------------------+
- *      | flags |////////////////////////////////|
- *      +-------+--------------------------------+
- *      |             message #                  |
- *      +----------------------------------------+
- *      |     payload (user-defined message)     |
- *      |                                        |
- *         		:
- *      |                                        |
- *      +----------------------------------------+
- *
- * The size of the payload is defined by the user via xpc_connect(). A user-
- * defined message resides in the payload area.
- *
- * The size of a message entry (within a message queue) must be a cacheline
- * sized multiple in order to facilitate the BTE transfer of messages from one
- * message queue to another. A macro, XPC_MSG_SIZE(), is provided for the user
+ * Define macro, XPC_MSG_SIZE(), is provided for the user
  * that wants to fit as many msg entries as possible in a given memory size
  * (e.g. a memory page).
  */
-struct xpc_msg {
-	u8 flags;		/* FOR XPC INTERNAL USE ONLY */
-	u8 reserved[7];		/* FOR XPC INTERNAL USE ONLY */
-	s64 number;		/* FOR XPC INTERNAL USE ONLY */
-
-	u64 payload;		/* user defined portion of message */
-};
+#define XPC_MSG_MAX_SIZE	128
+#define XPC_MSG_HDR_MAX_SIZE	16
+#define XPC_MSG_PAYLOAD_MAX_SIZE (XPC_MSG_MAX_SIZE - XPC_MSG_HDR_MAX_SIZE)
 
-#define XPC_MSG_PAYLOAD_OFFSET	(u64) (&((struct xpc_msg *)0)->payload)
 #define XPC_MSG_SIZE(_payload_size) \
-		L1_CACHE_ALIGN(XPC_MSG_PAYLOAD_OFFSET + (_payload_size))
+				ALIGN(XPC_MSG_HDR_MAX_SIZE + (_payload_size), \
+				      is_uv() ? 64 : 128)
+
 
 /*
  * Define the return values and values passed to user's callout functions.
@@ -210,7 +189,10 @@ enum xp_retval {
 	xpGruCopyError,		/* 58: gru_copy_gru() returned error */
 	xpGruSendMqError,	/* 59: gru send message queue related error */
 
-	xpUnknownReason		/* 60: unknown reason - must be last in enum */
+	xpBadChannelNumber,	/* 60: invalid channel number */
+	xpBadMsgType,		/* 60: invalid message type */
+
+	xpUnknownReason		/* 61: unknown reason - must be last in enum */
 };
 
 /*
@@ -261,6 +243,9 @@ typedef void (*xpc_channel_func) (enum xp_retval reason, short partid,
  * calling xpc_received().
  *
  * All other reason codes indicate failure.
+ *
+ * NOTE: The user defined function must be callable by an interrupt handler
+ *       and thus cannot block.
  */
 typedef void (*xpc_notify_func) (enum xp_retval reason, short partid,
 				 int ch_number, void *key);
@@ -284,7 +269,7 @@ struct xpc_registration {
 	xpc_channel_func func;	/* function to call */
 	void *key;		/* pointer to user's key */
 	u16 nentries;		/* #of msg entries in local msg queue */
-	u16 msg_size;		/* message queue's message size */
+	u16 entry_size;		/* message queue's message entry size */
 	u32 assigned_limit;	/* limit on #of assigned kthreads */
 	u32 idle_limit;		/* limit on #of idle kthreads */
 } ____cacheline_aligned;
diff --git a/drivers/misc/sgi-xp/xp_main.c b/drivers/misc/sgi-xp/xp_main.c
index f86ad3af26b..66a1d19e08a 100644
--- a/drivers/misc/sgi-xp/xp_main.c
+++ b/drivers/misc/sgi-xp/xp_main.c
@@ -154,6 +154,9 @@ xpc_connect(int ch_number, xpc_channel_func func, void *key, u16 payload_size,
 	DBUG_ON(func == NULL);
 	DBUG_ON(assigned_limit == 0 || idle_limit > assigned_limit);
 
+	if (XPC_MSG_SIZE(payload_size) > XPC_MSG_MAX_SIZE)
+		return xpPayloadTooBig;
+
 	registration = &xpc_registrations[ch_number];
 
 	if (mutex_lock_interruptible(&registration->mutex) != 0)
@@ -166,7 +169,7 @@ xpc_connect(int ch_number, xpc_channel_func func, void *key, u16 payload_size,
 	}
 
 	/* register the channel for connection */
-	registration->msg_size = XPC_MSG_SIZE(payload_size);
+	registration->entry_size = XPC_MSG_SIZE(payload_size);
 	registration->nentries = nentries;
 	registration->assigned_limit = assigned_limit;
 	registration->idle_limit = idle_limit;
@@ -220,7 +223,7 @@ xpc_disconnect(int ch_number)
 	registration->func = NULL;
 	registration->key = NULL;
 	registration->nentries = 0;
-	registration->msg_size = 0;
+	registration->entry_size = 0;
 	registration->assigned_limit = 0;
 	registration->idle_limit = 0;
 
diff --git a/drivers/misc/sgi-xp/xpc.h b/drivers/misc/sgi-xp/xpc.h
index 4c26181deff..619208d6186 100644
--- a/drivers/misc/sgi-xp/xpc.h
+++ b/drivers/misc/sgi-xp/xpc.h
@@ -181,8 +181,8 @@ struct xpc_vars_part_sn2 {
 				  xpc_nasid_mask_nlongs))
 
 /*
- * The activate_mq is used to send/receive messages that affect XPC's heartbeat,
- * partition active state, and channel state. This is UV only.
+ * The activate_mq is used to send/receive GRU messages that affect XPC's
+ * heartbeat, partition active state, and channel state. This is UV only.
  */
 struct xpc_activate_mq_msghdr_uv {
 	short partid;		/* sender's partid */
@@ -209,45 +209,45 @@ struct xpc_activate_mq_msghdr_uv {
 #define XPC_ACTIVATE_MQ_MSG_MARK_DISENGAGED_UV		11
 
 struct xpc_activate_mq_msg_uv {
-	struct xpc_activate_mq_msghdr_uv header;
+	struct xpc_activate_mq_msghdr_uv hdr;
 };
 
 struct xpc_activate_mq_msg_heartbeat_req_uv {
-	struct xpc_activate_mq_msghdr_uv header;
+	struct xpc_activate_mq_msghdr_uv hdr;
 	u64 heartbeat;
 };
 
 struct xpc_activate_mq_msg_activate_req_uv {
-	struct xpc_activate_mq_msghdr_uv header;
+	struct xpc_activate_mq_msghdr_uv hdr;
 	unsigned long rp_gpa;
 	unsigned long activate_mq_gpa;
 };
 
 struct xpc_activate_mq_msg_deactivate_req_uv {
-	struct xpc_activate_mq_msghdr_uv header;
+	struct xpc_activate_mq_msghdr_uv hdr;
 	enum xp_retval reason;
 };
 
 struct xpc_activate_mq_msg_chctl_closerequest_uv {
-	struct xpc_activate_mq_msghdr_uv header;
+	struct xpc_activate_mq_msghdr_uv hdr;
 	short ch_number;
 	enum xp_retval reason;
 };
 
 struct xpc_activate_mq_msg_chctl_closereply_uv {
-	struct xpc_activate_mq_msghdr_uv header;
+	struct xpc_activate_mq_msghdr_uv hdr;
 	short ch_number;
 };
 
 struct xpc_activate_mq_msg_chctl_openrequest_uv {
-	struct xpc_activate_mq_msghdr_uv header;
+	struct xpc_activate_mq_msghdr_uv hdr;
 	short ch_number;
-	short msg_size;		/* size of notify_mq's messages */
+	short entry_size;	/* size of notify_mq's GRU messages */
 	short local_nentries;	/* ??? Is this needed? What is? */
 };
 
 struct xpc_activate_mq_msg_chctl_openreply_uv {
-	struct xpc_activate_mq_msghdr_uv header;
+	struct xpc_activate_mq_msghdr_uv hdr;
 	short ch_number;
 	short remote_nentries;	/* ??? Is this needed? What is? */
 	short local_nentries;	/* ??? Is this needed? What is? */
@@ -284,7 +284,7 @@ struct xpc_gp_sn2 {
  */
 struct xpc_openclose_args {
 	u16 reason;		/* reason why channel is closing */
-	u16 msg_size;		/* sizeof each message entry */
+	u16 entry_size;		/* sizeof each message entry */
 	u16 remote_nentries;	/* #of message entries in remote msg queue */
 	u16 local_nentries;	/* #of message entries in local msg queue */
 	unsigned long local_msgqueue_pa; /* phys addr of local message queue */
@@ -294,22 +294,79 @@ struct xpc_openclose_args {
 	      L1_CACHE_ALIGN(sizeof(struct xpc_openclose_args) * \
 	      XPC_MAX_NCHANNELS)
 
-/* struct xpc_msg flags */
 
-#define	XPC_M_DONE		0x01	/* msg has been received/consumed */
-#define	XPC_M_READY		0x02	/* msg is ready to be sent */
-#define	XPC_M_INTERRUPT		0x04	/* send interrupt when msg consumed */
+/*
+ * Structures to define a fifo singly-linked list.
+ */
+
+struct xpc_fifo_entry_uv {
+	struct xpc_fifo_entry_uv *next;
+};
+
+struct xpc_fifo_head_uv {
+	struct xpc_fifo_entry_uv *first;
+	struct xpc_fifo_entry_uv *last;
+	spinlock_t lock;
+	int n_entries;
+};
+
+/*
+ * Define a sn2 styled message.
+ *
+ * A user-defined message resides in the payload area. The max size of the
+ * payload is defined by the user via xpc_connect().
+ *
+ * The size of a message entry (within a message queue) must be a 128-byte
+ * cacheline sized multiple in order to facilitate the BTE transfer of messages
+ * from one message queue to another.
+ */
+struct xpc_msg_sn2 {
+	u8 flags;		/* FOR XPC INTERNAL USE ONLY */
+	u8 reserved[7];		/* FOR XPC INTERNAL USE ONLY */
+	s64 number;		/* FOR XPC INTERNAL USE ONLY */
+
+	u64 payload;		/* user defined portion of message */
+};
+
+/* struct xpc_msg_sn2 flags */
+
+#define	XPC_M_SN2_DONE		0x01	/* msg has been received/consumed */
+#define	XPC_M_SN2_READY		0x02	/* msg is ready to be sent */
+#define	XPC_M_SN2_INTERRUPT	0x04	/* send interrupt when msg consumed */
+
+/*
+ * The format of a uv XPC notify_mq GRU message is as follows:
+ *
+ * A user-defined message resides in the payload area. The max size of the
+ * payload is defined by the user via xpc_connect().
+ *
+ * The size of a message (payload and header) sent via the GRU must be either 1
+ * or 2 GRU_CACHE_LINE_BYTES in length.
+ */
 
-#define XPC_MSG_ADDRESS(_payload) \
-		((struct xpc_msg *)((u8 *)(_payload) - XPC_MSG_PAYLOAD_OFFSET))
+struct xpc_notify_mq_msghdr_uv {
+	union {
+		unsigned int gru_msg_hdr;	/* FOR GRU INTERNAL USE ONLY */
+		struct xpc_fifo_entry_uv next;	/* FOR XPC INTERNAL USE ONLY */
+	} u;
+	short partid;		/* FOR XPC INTERNAL USE ONLY */
+	u8 ch_number;		/* FOR XPC INTERNAL USE ONLY */
+	u8 size;		/* FOR XPC INTERNAL USE ONLY */
+	unsigned int msg_slot_number;	/* FOR XPC INTERNAL USE ONLY */
+};
+
+struct xpc_notify_mq_msg_uv {
+	struct xpc_notify_mq_msghdr_uv hdr;
+	unsigned long payload;
+};
 
 /*
- * Defines notify entry.
+ * Define sn2's notify entry.
  *
  * This is used to notify a message's sender that their message was received
  * and consumed by the intended recipient.
  */
-struct xpc_notify {
+struct xpc_notify_sn2 {
 	u8 type;		/* type of notification */
 
 	/* the following two fields are only used if type == XPC_N_CALL */
@@ -317,9 +374,20 @@ struct xpc_notify {
 	void *key;		/* pointer to user's key */
 };
 
-/* struct xpc_notify type of notification */
+/* struct xpc_notify_sn2 type of notification */
 
-#define	XPC_N_CALL		0x01	/* notify function provided by user */
+#define	XPC_N_CALL	0x01	/* notify function provided by user */
+
+/*
+ * Define uv's version of the notify entry. It additionally is used to allocate
+ * a msg slot on the remote partition into which is copied a sent message.
+ */
+struct xpc_send_msg_slot_uv {
+	struct xpc_fifo_entry_uv next;
+	unsigned int msg_slot_number;
+	xpc_notify_func func;	/* user's notify function */
+	void *key;		/* pointer to user's key */
+};
 
 /*
  * Define the structure that manages all the stuff required by a channel. In
@@ -409,14 +477,14 @@ struct xpc_channel_sn2 {
 					     /* opening or closing of channel */
 
 	void *local_msgqueue_base;	/* base address of kmalloc'd space */
-	struct xpc_msg *local_msgqueue;	/* local message queue */
+	struct xpc_msg_sn2 *local_msgqueue;	/* local message queue */
 	void *remote_msgqueue_base;	/* base address of kmalloc'd space */
-	struct xpc_msg *remote_msgqueue; /* cached copy of remote partition's */
-					 /* local message queue */
+	struct xpc_msg_sn2 *remote_msgqueue; /* cached copy of remote */
+					   /* partition's local message queue */
 	unsigned long remote_msgqueue_pa; /* phys addr of remote partition's */
 					  /* local message queue */
 
-	struct xpc_notify *notify_queue;    /* notify queue for messages sent */
+	struct xpc_notify_sn2 *notify_queue;/* notify queue for messages sent */
 
 	/* various flavors of local and remote Get/Put values */
 
@@ -432,6 +500,12 @@ struct xpc_channel_sn2 {
 struct xpc_channel_uv {
 	unsigned long remote_notify_mq_gpa;	/* gru phys address of remote */
 						/* partition's notify mq */
+
+	struct xpc_send_msg_slot_uv *send_msg_slots;
+	struct xpc_notify_mq_msg_uv *recv_msg_slots;
+
+	struct xpc_fifo_head_uv msg_slot_free_list;
+	struct xpc_fifo_head_uv recv_msg_list;	/* deliverable payloads */
 };
 
 struct xpc_channel {
@@ -444,7 +518,7 @@ struct xpc_channel {
 
 	u16 number;		/* channel # */
 
-	u16 msg_size;		/* sizeof each msg entry */
+	u16 entry_size;		/* sizeof each msg entry */
 	u16 local_nentries;	/* #of msg entries in local msg queue */
 	u16 remote_nentries;	/* #of msg entries in remote msg queue */
 
@@ -733,8 +807,8 @@ extern enum xp_retval (*xpc_setup_msg_structures) (struct xpc_channel *);
 extern void (*xpc_teardown_msg_structures) (struct xpc_channel *);
 extern void (*xpc_notify_senders_of_disconnect) (struct xpc_channel *);
 extern void (*xpc_process_msg_chctl_flags) (struct xpc_partition *, int);
-extern int (*xpc_n_of_deliverable_msgs) (struct xpc_channel *);
-extern struct xpc_msg *(*xpc_get_deliverable_msg) (struct xpc_channel *);
+extern int (*xpc_n_of_deliverable_payloads) (struct xpc_channel *);
+extern void *(*xpc_get_deliverable_payload) (struct xpc_channel *);
 extern void (*xpc_request_partition_activation) (struct xpc_rsvd_page *,
 						 unsigned long, int);
 extern void (*xpc_request_partition_reactivation) (struct xpc_partition *);
@@ -762,9 +836,9 @@ extern void (*xpc_send_chctl_openreply) (struct xpc_channel *, unsigned long *);
 extern void (*xpc_save_remote_msgqueue_pa) (struct xpc_channel *,
 					    unsigned long);
 
-extern enum xp_retval (*xpc_send_msg) (struct xpc_channel *, u32, void *, u16,
-				       u8, xpc_notify_func, void *);
-extern void (*xpc_received_msg) (struct xpc_channel *, struct xpc_msg *);
+extern enum xp_retval (*xpc_send_payload) (struct xpc_channel *, u32, void *,
+					   u16, u8, xpc_notify_func, void *);
+extern void (*xpc_received_payload) (struct xpc_channel *, void *);
 
 /* found in xpc_sn2.c */
 extern int xpc_init_sn2(void);
@@ -805,7 +879,7 @@ extern enum xp_retval xpc_initiate_send_notify(short, int, u32, void *, u16,
 extern void xpc_initiate_received(short, int, void *);
 extern void xpc_process_sent_chctl_flags(struct xpc_partition *);
 extern void xpc_connected_callout(struct xpc_channel *);
-extern void xpc_deliver_msg(struct xpc_channel *);
+extern void xpc_deliver_payload(struct xpc_channel *);
 extern void xpc_disconnect_channel(const int, struct xpc_channel *,
 				   enum xp_retval, unsigned long *);
 extern void xpc_disconnect_callout(struct xpc_channel *, enum xp_retval);
diff --git a/drivers/misc/sgi-xp/xpc_channel.c b/drivers/misc/sgi-xp/xpc_channel.c
index 73df9fb5ee6..9cd2ebe2a3b 100644
--- a/drivers/misc/sgi-xp/xpc_channel.c
+++ b/drivers/misc/sgi-xp/xpc_channel.c
@@ -139,7 +139,7 @@ xpc_process_disconnect(struct xpc_channel *ch, unsigned long *irq_flags)
 
 	ch->func = NULL;
 	ch->key = NULL;
-	ch->msg_size = 0;
+	ch->entry_size = 0;
 	ch->local_nentries = 0;
 	ch->remote_nentries = 0;
 	ch->kthreads_assigned_limit = 0;
@@ -315,9 +315,9 @@ again:
 
 	if (chctl_flags & XPC_CHCTL_OPENREQUEST) {
 
-		dev_dbg(xpc_chan, "XPC_CHCTL_OPENREQUEST (msg_size=%d, "
+		dev_dbg(xpc_chan, "XPC_CHCTL_OPENREQUEST (entry_size=%d, "
 			"local_nentries=%d) received from partid=%d, "
-			"channel=%d\n", args->msg_size, args->local_nentries,
+			"channel=%d\n", args->entry_size, args->local_nentries,
 			ch->partid, ch->number);
 
 		if (part->act_state == XPC_P_AS_DEACTIVATING ||
@@ -338,10 +338,10 @@ again:
 
 		/*
 		 * The meaningful OPENREQUEST connection state fields are:
-		 *      msg_size = size of channel's messages in bytes
+		 *      entry_size = size of channel's messages in bytes
 		 *      local_nentries = remote partition's local_nentries
 		 */
-		if (args->msg_size == 0 || args->local_nentries == 0) {
+		if (args->entry_size == 0 || args->local_nentries == 0) {
 			/* assume OPENREQUEST was delayed by mistake */
 			spin_unlock_irqrestore(&ch->lock, irq_flags);
 			return;
@@ -351,14 +351,14 @@ again:
 		ch->remote_nentries = args->local_nentries;
 
 		if (ch->flags & XPC_C_OPENREQUEST) {
-			if (args->msg_size != ch->msg_size) {
+			if (args->entry_size != ch->entry_size) {
 				XPC_DISCONNECT_CHANNEL(ch, xpUnequalMsgSizes,
 						       &irq_flags);
 				spin_unlock_irqrestore(&ch->lock, irq_flags);
 				return;
 			}
 		} else {
-			ch->msg_size = args->msg_size;
+			ch->entry_size = args->entry_size;
 
 			XPC_SET_REASON(ch, 0, 0);
 			ch->flags &= ~XPC_C_DISCONNECTED;
@@ -473,7 +473,7 @@ xpc_connect_channel(struct xpc_channel *ch)
 	ch->local_nentries = registration->nentries;
 
 	if (ch->flags & XPC_C_ROPENREQUEST) {
-		if (registration->msg_size != ch->msg_size) {
+		if (registration->entry_size != ch->entry_size) {
 			/* the local and remote sides aren't the same */
 
 			/*
@@ -492,7 +492,7 @@ xpc_connect_channel(struct xpc_channel *ch)
 			return xpUnequalMsgSizes;
 		}
 	} else {
-		ch->msg_size = registration->msg_size;
+		ch->entry_size = registration->entry_size;
 
 		XPC_SET_REASON(ch, 0, 0);
 		ch->flags &= ~XPC_C_DISCONNECTED;
@@ -859,8 +859,8 @@ xpc_initiate_send(short partid, int ch_number, u32 flags, void *payload,
 	DBUG_ON(payload == NULL);
 
 	if (xpc_part_ref(part)) {
-		ret = xpc_send_msg(&part->channels[ch_number], flags, payload,
-				   payload_size, 0, NULL, NULL);
+		ret = xpc_send_payload(&part->channels[ch_number], flags,
+				       payload, payload_size, 0, NULL, NULL);
 		xpc_part_deref(part);
 	}
 
@@ -911,23 +911,24 @@ xpc_initiate_send_notify(short partid, int ch_number, u32 flags, void *payload,
 	DBUG_ON(func == NULL);
 
 	if (xpc_part_ref(part)) {
-		ret = xpc_send_msg(&part->channels[ch_number], flags, payload,
-				   payload_size, XPC_N_CALL, func, key);
+		ret = xpc_send_payload(&part->channels[ch_number], flags,
+				       payload, payload_size, XPC_N_CALL, func,
+				       key);
 		xpc_part_deref(part);
 	}
 	return ret;
 }
 
 /*
- * Deliver a message to its intended recipient.
+ * Deliver a message's payload to its intended recipient.
  */
 void
-xpc_deliver_msg(struct xpc_channel *ch)
+xpc_deliver_payload(struct xpc_channel *ch)
 {
-	struct xpc_msg *msg;
+	void *payload;
 
-	msg = xpc_get_deliverable_msg(ch);
-	if (msg != NULL) {
+	payload = xpc_get_deliverable_payload(ch);
+	if (payload != NULL) {
 
 		/*
 		 * This ref is taken to protect the payload itself from being
@@ -939,18 +940,16 @@ xpc_deliver_msg(struct xpc_channel *ch)
 		atomic_inc(&ch->kthreads_active);
 
 		if (ch->func != NULL) {
-			dev_dbg(xpc_chan, "ch->func() called, msg=0x%p, "
-				"msg_number=%ld, partid=%d, channel=%d\n",
-				msg, (signed long)msg->number, ch->partid,
+			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,
-				 &msg->payload, ch->key);
+			ch->func(xpMsgReceived, ch->partid, ch->number, payload,
+				 ch->key);
 
-			dev_dbg(xpc_chan, "ch->func() returned, msg=0x%p, "
-				"msg_number=%ld, partid=%d, channel=%d\n",
-				msg, (signed long)msg->number, ch->partid,
+			dev_dbg(xpc_chan, "ch->func() returned, payload=0x%p "
+				"partid=%d channel=%d\n", payload, ch->partid,
 				ch->number);
 		}
 
@@ -959,14 +958,11 @@ xpc_deliver_msg(struct xpc_channel *ch)
 }
 
 /*
- * Acknowledge receipt of a delivered message.
- *
- * If a message has XPC_M_INTERRUPT set, send an interrupt to the partition
- * that sent the message.
+ * 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_msg().
+ * fact that we called xpc_msgqueue_ref() in xpc_deliver_payload().
  *
  * Arguments:
  *
@@ -980,14 +976,13 @@ 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);
 
 	DBUG_ON(partid < 0 || partid >= xp_max_npartitions);
 	DBUG_ON(ch_number < 0 || ch_number >= part->nchannels);
 
 	ch = &part->channels[ch_number];
-	xpc_received_msg(ch, msg);
+	xpc_received_payload(ch, payload);
 
-	/* the call to xpc_msgqueue_ref() was done by xpc_deliver_msg()  */
+	/* the call to xpc_msgqueue_ref() was done by xpc_deliver_payload()  */
 	xpc_msgqueue_deref(ch);
 }
diff --git a/drivers/misc/sgi-xp/xpc_main.c b/drivers/misc/sgi-xp/xpc_main.c
index 13ec4792899..46325fc8481 100644
--- a/drivers/misc/sgi-xp/xpc_main.c
+++ b/drivers/misc/sgi-xp/xpc_main.c
@@ -188,8 +188,8 @@ u64 (*xpc_get_chctl_all_flags) (struct xpc_partition *part);
 enum xp_retval (*xpc_setup_msg_structures) (struct xpc_channel *ch);
 void (*xpc_teardown_msg_structures) (struct xpc_channel *ch);
 void (*xpc_process_msg_chctl_flags) (struct xpc_partition *part, int ch_number);
-int (*xpc_n_of_deliverable_msgs) (struct xpc_channel *ch);
-struct xpc_msg *(*xpc_get_deliverable_msg) (struct xpc_channel *ch);
+int (*xpc_n_of_deliverable_payloads) (struct xpc_channel *ch);
+void *(*xpc_get_deliverable_payload) (struct xpc_channel *ch);
 
 void (*xpc_request_partition_activation) (struct xpc_rsvd_page *remote_rp,
 					  unsigned long remote_rp_pa,
@@ -220,10 +220,11 @@ void (*xpc_send_chctl_openreply) (struct xpc_channel *ch,
 void (*xpc_save_remote_msgqueue_pa) (struct xpc_channel *ch,
 				     unsigned long msgqueue_pa);
 
-enum xp_retval (*xpc_send_msg) (struct xpc_channel *ch, u32 flags,
-				void *payload, u16 payload_size, u8 notify_type,
-				xpc_notify_func func, void *key);
-void (*xpc_received_msg) (struct xpc_channel *ch, struct xpc_msg *msg);
+enum xp_retval (*xpc_send_payload) (struct xpc_channel *ch, u32 flags,
+				    void *payload, u16 payload_size,
+				    u8 notify_type, xpc_notify_func func,
+				    void *key);
+void (*xpc_received_payload) (struct xpc_channel *ch, void *payload);
 
 /*
  * Timer function to enforce the timelimit on the partition disengage.
@@ -714,9 +715,9 @@ xpc_kthread_waitmsgs(struct xpc_partition *part, struct xpc_channel *ch)
 	do {
 		/* deliver messages to their intended recipients */
 
-		while (xpc_n_of_deliverable_msgs(ch) > 0 &&
+		while (xpc_n_of_deliverable_payloads(ch) > 0 &&
 		       !(ch->flags & XPC_C_DISCONNECTING)) {
-			xpc_deliver_msg(ch);
+			xpc_deliver_payload(ch);
 		}
 
 		if (atomic_inc_return(&ch->kthreads_idle) >
@@ -730,7 +731,7 @@ xpc_kthread_waitmsgs(struct xpc_partition *part, struct xpc_channel *ch)
 			"wait_event_interruptible_exclusive()\n");
 
 		(void)wait_event_interruptible_exclusive(ch->idle_wq,
-				(xpc_n_of_deliverable_msgs(ch) > 0 ||
+				(xpc_n_of_deliverable_payloads(ch) > 0 ||
 				 (ch->flags & XPC_C_DISCONNECTING)));
 
 		atomic_dec(&ch->kthreads_idle);
@@ -775,7 +776,7 @@ xpc_kthread_start(void *args)
 			 * additional kthreads to help deliver them. We only
 			 * need one less than total #of messages to deliver.
 			 */
-			n_needed = xpc_n_of_deliverable_msgs(ch) - 1;
+			n_needed = xpc_n_of_deliverable_payloads(ch) - 1;
 			if (n_needed > 0 && !(ch->flags & XPC_C_DISCONNECTING))
 				xpc_activate_kthreads(ch, n_needed);
 
diff --git a/drivers/misc/sgi-xp/xpc_sn2.c b/drivers/misc/sgi-xp/xpc_sn2.c
index 8b4b0653d9e..b4882ccf634 100644
--- a/drivers/misc/sgi-xp/xpc_sn2.c
+++ b/drivers/misc/sgi-xp/xpc_sn2.c
@@ -408,7 +408,7 @@ xpc_send_chctl_openrequest_sn2(struct xpc_channel *ch, unsigned long *irq_flags)
 {
 	struct xpc_openclose_args *args = ch->sn.sn2.local_openclose_args;
 
-	args->msg_size = ch->msg_size;
+	args->entry_size = ch->entry_size;
 	args->local_nentries = ch->local_nentries;
 	XPC_SEND_NOTIFY_IRQ_SN2(ch, XPC_CHCTL_OPENREQUEST, irq_flags);
 }
@@ -1531,14 +1531,14 @@ xpc_allocate_local_msgqueue_sn2(struct xpc_channel *ch)
 
 	for (nentries = ch->local_nentries; nentries > 0; nentries--) {
 
-		nbytes = nentries * ch->msg_size;
+		nbytes = nentries * ch->entry_size;
 		ch_sn2->local_msgqueue =
 		    xpc_kzalloc_cacheline_aligned(nbytes, GFP_KERNEL,
 						  &ch_sn2->local_msgqueue_base);
 		if (ch_sn2->local_msgqueue == NULL)
 			continue;
 
-		nbytes = nentries * sizeof(struct xpc_notify);
+		nbytes = nentries * sizeof(struct xpc_notify_sn2);
 		ch_sn2->notify_queue = kzalloc(nbytes, GFP_KERNEL);
 		if (ch_sn2->notify_queue == NULL) {
 			kfree(ch_sn2->local_msgqueue_base);
@@ -1578,7 +1578,7 @@ xpc_allocate_remote_msgqueue_sn2(struct xpc_channel *ch)
 
 	for (nentries = ch->remote_nentries; nentries > 0; nentries--) {
 
-		nbytes = nentries * ch->msg_size;
+		nbytes = nentries * ch->entry_size;
 		ch_sn2->remote_msgqueue =
 		    xpc_kzalloc_cacheline_aligned(nbytes, GFP_KERNEL, &ch_sn2->
 						  remote_msgqueue_base);
@@ -1632,9 +1632,6 @@ xpc_setup_msg_structures_sn2(struct xpc_channel *ch)
 /*
  * Free up message queues and other stuff that were allocated for the specified
  * channel.
- *
- * Note: ch->reason and ch->reason_line are left set for debugging purposes,
- * they're cleared when XPC_C_DISCONNECTED is cleared.
  */
 static void
 xpc_teardown_msg_structures_sn2(struct xpc_channel *ch)
@@ -1674,7 +1671,7 @@ xpc_teardown_msg_structures_sn2(struct xpc_channel *ch)
 static void
 xpc_notify_senders_sn2(struct xpc_channel *ch, enum xp_retval reason, s64 put)
 {
-	struct xpc_notify *notify;
+	struct xpc_notify_sn2 *notify;
 	u8 notify_type;
 	s64 get = ch->sn.sn2.w_remote_GP.get - 1;
 
@@ -1699,17 +1696,16 @@ xpc_notify_senders_sn2(struct xpc_channel *ch, enum xp_retval reason, s64 put)
 		atomic_dec(&ch->n_to_notify);
 
 		if (notify->func != NULL) {
-			dev_dbg(xpc_chan, "notify->func() called, notify=0x%p, "
-				"msg_number=%ld, partid=%d, channel=%d\n",
+			dev_dbg(xpc_chan, "notify->func() called, notify=0x%p "
+				"msg_number=%ld partid=%d channel=%d\n",
 				(void *)notify, get, ch->partid, ch->number);
 
 			notify->func(reason, ch->partid, ch->number,
 				     notify->key);
 
-			dev_dbg(xpc_chan, "notify->func() returned, "
-				"notify=0x%p, msg_number=%ld, partid=%d, "
-				"channel=%d\n", (void *)notify, get,
-				ch->partid, ch->number);
+			dev_dbg(xpc_chan, "notify->func() returned, notify=0x%p"
+				" msg_number=%ld partid=%d channel=%d\n",
+				(void *)notify, get, ch->partid, ch->number);
 		}
 	}
 }
@@ -1727,14 +1723,14 @@ static inline void
 xpc_clear_local_msgqueue_flags_sn2(struct xpc_channel *ch)
 {
 	struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
-	struct xpc_msg *msg;
+	struct xpc_msg_sn2 *msg;
 	s64 get;
 
 	get = ch_sn2->w_remote_GP.get;
 	do {
-		msg = (struct xpc_msg *)((u64)ch_sn2->local_msgqueue +
-					 (get % ch->local_nentries) *
-					 ch->msg_size);
+		msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->local_msgqueue +
+					     (get % ch->local_nentries) *
+					     ch->entry_size);
 		msg->flags = 0;
 	} while (++get < ch_sn2->remote_GP.get);
 }
@@ -1746,24 +1742,30 @@ static inline void
 xpc_clear_remote_msgqueue_flags_sn2(struct xpc_channel *ch)
 {
 	struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
-	struct xpc_msg *msg;
+	struct xpc_msg_sn2 *msg;
 	s64 put;
 
 	put = ch_sn2->w_remote_GP.put;
 	do {
-		msg = (struct xpc_msg *)((u64)ch_sn2->remote_msgqueue +
-					 (put % ch->remote_nentries) *
-					 ch->msg_size);
+		msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->remote_msgqueue +
+					     (put % ch->remote_nentries) *
+					     ch->entry_size);
 		msg->flags = 0;
 	} while (++put < ch_sn2->remote_GP.put);
 }
 
+static int
+xpc_n_of_deliverable_payloads_sn2(struct xpc_channel *ch)
+{
+	return ch->sn.sn2.w_remote_GP.put - ch->sn.sn2.w_local_GP.get;
+}
+
 static void
 xpc_process_msg_chctl_flags_sn2(struct xpc_partition *part, int ch_number)
 {
 	struct xpc_channel *ch = &part->channels[ch_number];
 	struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
-	int nmsgs_sent;
+	int npayloads_sent;
 
 	ch_sn2->remote_GP = part->sn.sn2.remote_GPs[ch_number];
 
@@ -1835,7 +1837,7 @@ xpc_process_msg_chctl_flags_sn2(struct xpc_partition *part, int ch_number)
 	if (ch_sn2->w_remote_GP.put != ch_sn2->remote_GP.put) {
 		/*
 		 * Clear msg->flags in previously received messages, so that
-		 * they're ready for xpc_get_deliverable_msg().
+		 * they're ready for xpc_get_deliverable_payload_sn2().
 		 */
 		xpc_clear_remote_msgqueue_flags_sn2(ch);
 
@@ -1845,27 +1847,27 @@ xpc_process_msg_chctl_flags_sn2(struct xpc_partition *part, int ch_number)
 			"channel=%d\n", ch_sn2->w_remote_GP.put, ch->partid,
 			ch->number);
 
-		nmsgs_sent = ch_sn2->w_remote_GP.put - ch_sn2->w_local_GP.get;
-		if (nmsgs_sent > 0) {
+		npayloads_sent = xpc_n_of_deliverable_payloads_sn2(ch);
+		if (npayloads_sent > 0) {
 			dev_dbg(xpc_chan, "msgs waiting to be copied and "
 				"delivered=%d, partid=%d, channel=%d\n",
-				nmsgs_sent, ch->partid, ch->number);
+				npayloads_sent, ch->partid, ch->number);
 
 			if (ch->flags & XPC_C_CONNECTEDCALLOUT_MADE)
-				xpc_activate_kthreads(ch, nmsgs_sent);
+				xpc_activate_kthreads(ch, npayloads_sent);
 		}
 	}
 
 	xpc_msgqueue_deref(ch);
 }
 
-static struct xpc_msg *
+static struct xpc_msg_sn2 *
 xpc_pull_remote_msg_sn2(struct xpc_channel *ch, s64 get)
 {
 	struct xpc_partition *part = &xpc_partitions[ch->partid];
 	struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
 	unsigned long remote_msg_pa;
-	struct xpc_msg *msg;
+	struct xpc_msg_sn2 *msg;
 	u32 msg_index;
 	u32 nmsgs;
 	u64 msg_offset;
@@ -1889,13 +1891,13 @@ xpc_pull_remote_msg_sn2(struct xpc_channel *ch, s64 get)
 			nmsgs = ch->remote_nentries - msg_index;
 		}
 
-		msg_offset = msg_index * ch->msg_size;
-		msg = (struct xpc_msg *)((u64)ch_sn2->remote_msgqueue +
+		msg_offset = msg_index * ch->entry_size;
+		msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->remote_msgqueue +
 		    msg_offset);
 		remote_msg_pa = ch_sn2->remote_msgqueue_pa + msg_offset;
 
 		ret = xpc_pull_remote_cachelines_sn2(part, msg, remote_msg_pa,
-						     nmsgs * ch->msg_size);
+						     nmsgs * ch->entry_size);
 		if (ret != xpSuccess) {
 
 			dev_dbg(xpc_chan, "failed to pull %d msgs starting with"
@@ -1915,26 +1917,21 @@ xpc_pull_remote_msg_sn2(struct xpc_channel *ch, s64 get)
 	mutex_unlock(&ch_sn2->msg_to_pull_mutex);
 
 	/* return the message we were looking for */
-	msg_offset = (get % ch->remote_nentries) * ch->msg_size;
-	msg = (struct xpc_msg *)((u64)ch_sn2->remote_msgqueue + msg_offset);
+	msg_offset = (get % ch->remote_nentries) * ch->entry_size;
+	msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->remote_msgqueue + msg_offset);
 
 	return msg;
 }
 
-static int
-xpc_n_of_deliverable_msgs_sn2(struct xpc_channel *ch)
-{
-	return ch->sn.sn2.w_remote_GP.put - ch->sn.sn2.w_local_GP.get;
-}
-
 /*
- * Get a message to be delivered.
+ * Get the next deliverable message's payload.
  */
-static struct xpc_msg *
-xpc_get_deliverable_msg_sn2(struct xpc_channel *ch)
+static void *
+xpc_get_deliverable_payload_sn2(struct xpc_channel *ch)
 {
 	struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
-	struct xpc_msg *msg = NULL;
+	struct xpc_msg_sn2 *msg;
+	void *payload = NULL;
 	s64 get;
 
 	do {
@@ -1965,15 +1962,16 @@ xpc_get_deliverable_msg_sn2(struct xpc_channel *ch)
 			msg = xpc_pull_remote_msg_sn2(ch, get);
 
 			DBUG_ON(msg != NULL && msg->number != get);
-			DBUG_ON(msg != NULL && (msg->flags & XPC_M_DONE));
-			DBUG_ON(msg != NULL && !(msg->flags & XPC_M_READY));
+			DBUG_ON(msg != NULL && (msg->flags & XPC_M_SN2_DONE));
+			DBUG_ON(msg != NULL && !(msg->flags & XPC_M_SN2_READY));
 
+			payload = &msg->payload;
 			break;
 		}
 
 	} while (1);
 
-	return msg;
+	return payload;
 }
 
 /*
@@ -1985,7 +1983,7 @@ static void
 xpc_send_msgs_sn2(struct xpc_channel *ch, s64 initial_put)
 {
 	struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
-	struct xpc_msg *msg;
+	struct xpc_msg_sn2 *msg;
 	s64 put = initial_put + 1;
 	int send_msgrequest = 0;
 
@@ -1995,11 +1993,12 @@ xpc_send_msgs_sn2(struct xpc_channel *ch, s64 initial_put)
 			if (put == ch_sn2->w_local_GP.put)
 				break;
 
-			msg = (struct xpc_msg *)((u64)ch_sn2->local_msgqueue +
-						 (put % ch->local_nentries) *
-						 ch->msg_size);
+			msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->
+						     local_msgqueue + (put %
+						     ch->local_nentries) *
+						     ch->entry_size);
 
-			if (!(msg->flags & XPC_M_READY))
+			if (!(msg->flags & XPC_M_SN2_READY))
 				break;
 
 			put++;
@@ -2026,7 +2025,7 @@ xpc_send_msgs_sn2(struct xpc_channel *ch, s64 initial_put)
 
 		/*
 		 * We need to ensure that the message referenced by
-		 * local_GP->put is not XPC_M_READY or that local_GP->put
+		 * local_GP->put is not XPC_M_SN2_READY or that local_GP->put
 		 * equals w_local_GP.put, so we'll go have a look.
 		 */
 		initial_put = put;
@@ -2042,10 +2041,10 @@ xpc_send_msgs_sn2(struct xpc_channel *ch, s64 initial_put)
  */
 static enum xp_retval
 xpc_allocate_msg_sn2(struct xpc_channel *ch, u32 flags,
-		     struct xpc_msg **address_of_msg)
+		     struct xpc_msg_sn2 **address_of_msg)
 {
 	struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
-	struct xpc_msg *msg;
+	struct xpc_msg_sn2 *msg;
 	enum xp_retval ret;
 	s64 put;
 
@@ -2097,8 +2096,9 @@ xpc_allocate_msg_sn2(struct xpc_channel *ch, u32 flags,
 	}
 
 	/* get the message's address and initialize it */
-	msg = (struct xpc_msg *)((u64)ch_sn2->local_msgqueue +
-				 (put % ch->local_nentries) * ch->msg_size);
+	msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->local_msgqueue +
+				     (put % ch->local_nentries) *
+				     ch->entry_size);
 
 	DBUG_ON(msg->flags != 0);
 	msg->number = put;
@@ -2117,20 +2117,20 @@ xpc_allocate_msg_sn2(struct xpc_channel *ch, u32 flags,
  * partition the message is being sent to.
  */
 static enum xp_retval
-xpc_send_msg_sn2(struct xpc_channel *ch, u32 flags, void *payload,
-		 u16 payload_size, u8 notify_type, xpc_notify_func func,
-		 void *key)
+xpc_send_payload_sn2(struct xpc_channel *ch, u32 flags, void *payload,
+		     u16 payload_size, u8 notify_type, xpc_notify_func func,
+		     void *key)
 {
 	enum xp_retval ret = xpSuccess;
 	struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
-	struct