Pull xpc-disengage into release branch

arch/ia64/sn/kernel/xpc_partition.c

@@ -47,13 +47,16 @@ static u64 xpc_sh2_IPI_access3;
 u64 xpc_prot_vec[MAX_NUMNODES];
 
 
-/* this partition's reserved page */
+/* this partition's reserved page pointers */
 struct xpc_rsvd_page *xpc_rsvd_page;
-
-/* this partition's XPC variables (within the reserved page) */
+static u64 *xpc_part_nasids;
+static u64 *xpc_mach_nasids;
 struct xpc_vars *xpc_vars;
 struct xpc_vars_part *xpc_vars_part;
 
+static int xp_nasid_mask_bytes;	/* actual size in bytes of nasid mask */
+static int xp_nasid_mask_words;	/* actual size in words of nasid mask */
+
 
 /*
  * For performance reasons, each entry of xpc_partitions[] is cacheline
@@ -65,20 +68,16 @@ struct xpc_partition xpc_partitions[XP_MAX_PARTITIONS + 1];
 
 
 /*
- * Generic buffer used to store a local copy of the remote partitions
- * reserved page or XPC variables.
+ * Generic buffer used to store a local copy of portions of a remote
+ * partition's reserved page (either its header and part_nasids mask,
+ * or its vars).
  *
  * xpc_discovery runs only once and is a seperate thread that is
  * very likely going to be processing in parallel with receiving
  * interrupts.
  */
-char ____cacheline_aligned
-		xpc_remote_copy_buffer[XPC_RSVD_PAGE_ALIGNED_SIZE];
-
-
-/* systune related variables */
-int xpc_hb_interval = XPC_HB_DEFAULT_INTERVAL;
-int xpc_hb_check_interval = XPC_HB_CHECK_DEFAULT_TIMEOUT;
+char ____cacheline_aligned xpc_remote_copy_buffer[XPC_RP_HEADER_SIZE +
+							XP_NASID_MASK_BYTES];
 
 
 /*
@@ -86,13 +85,16 @@ int xpc_hb_check_interval = XPC_HB_CHECK_DEFAULT_TIMEOUT;
  * for that nasid. This function returns 0 on any error.
  */
 static u64
-xpc_get_rsvd_page_pa(int nasid, u64 buf, u64 buf_size)
+xpc_get_rsvd_page_pa(int nasid)
 {
 	bte_result_t bte_res;
 	s64 status;
 	u64 cookie = 0;
 	u64 rp_pa = nasid;	/* seed with nasid */
 	u64 len = 0;
+	u64 buf = buf;
+	u64 buf_len = 0;
+	void *buf_base = NULL;
 
 
 	while (1) {
@@ -108,13 +110,22 @@ xpc_get_rsvd_page_pa(int nasid, u64 buf, u64 buf_size)
 			break;
 		}
 
-		if (len > buf_size) {
-			dev_err(xpc_part, "len (=0x%016lx) > buf_size\n", len);
-			status = SALRET_ERROR;
-			break;
+		if (L1_CACHE_ALIGN(len) > buf_len) {
+			if (buf_base != NULL) {
+				kfree(buf_base);
+			}
+			buf_len = L1_CACHE_ALIGN(len);
+			buf = (u64) xpc_kmalloc_cacheline_aligned(buf_len,
+							GFP_KERNEL, &buf_base);
+			if (buf_base == NULL) {
+				dev_err(xpc_part, "unable to kmalloc "
+					"len=0x%016lx\n", buf_len);
+				status = SALRET_ERROR;
+				break;
+			}
 		}
 
-		bte_res = xp_bte_copy(rp_pa, ia64_tpa(buf), buf_size,
+		bte_res = xp_bte_copy(rp_pa, ia64_tpa(buf), buf_len,
 					(BTE_NOTIFY | BTE_WACQUIRE), NULL);
 		if (bte_res != BTE_SUCCESS) {
 			dev_dbg(xpc_part, "xp_bte_copy failed %i\n", bte_res);
@@ -123,6 +134,10 @@ xpc_get_rsvd_page_pa(int nasid, u64 buf, u64 buf_size)
 		}
 	}
 
+	if (buf_base != NULL) {
+		kfree(buf_base);
+	}
+
 	if (status != SALRET_OK) {
 		rp_pa = 0;
 	}
@@ -141,15 +156,15 @@ xpc_rsvd_page_init(void)
 {
 	struct xpc_rsvd_page *rp;
 	AMO_t *amos_page;
-	u64 rp_pa, next_cl, nasid_array = 0;
+	u64 rp_pa, nasid_array = 0;
 	int i, ret;
 
 
 	/* get the local reserved page's address */
 
-	rp_pa = xpc_get_rsvd_page_pa(cnodeid_to_nasid(0),
-					(u64) xpc_remote_copy_buffer,
-						XPC_RSVD_PAGE_ALIGNED_SIZE);
+	preempt_disable();
+	rp_pa = xpc_get_rsvd_page_pa(cpuid_to_nasid(smp_processor_id()));
+	preempt_enable();
 	if (rp_pa == 0) {
 		dev_err(xpc_part, "SAL failed to locate the reserved page\n");
 		return NULL;
@@ -164,12 +179,19 @@ xpc_rsvd_page_init(void)
 
 	rp->version = XPC_RP_VERSION;
 
-	/*
-	 * Place the XPC variables on the cache line following the
-	 * reserved page structure.
-	 */
-	next_cl = (u64) rp + XPC_RSVD_PAGE_ALIGNED_SIZE;
-	xpc_vars = (struct xpc_vars *) next_cl;
+	/* establish the actual sizes of the nasid masks */
+	if (rp->SAL_version == 1) {
+		/* SAL_version 1 didn't set the nasids_size field */
+		rp->nasids_size = 128;
+	}
+	xp_nasid_mask_bytes = rp->nasids_size;
+	xp_nasid_mask_words = xp_nasid_mask_bytes / 8;
+
+	/* setup the pointers to the various items in the reserved page */
+	xpc_part_nasids = XPC_RP_PART_NASIDS(rp);
+	xpc_mach_nasids = XPC_RP_MACH_NASIDS(rp);
+	xpc_vars = XPC_RP_VARS(rp);
+	xpc_vars_part = XPC_RP_VARS_PART(rp);
 
 	/*
 	 * Before clearing xpc_vars, see if a page of AMOs had been previously
@@ -221,33 +243,32 @@ xpc_rsvd_page_init(void)
 		amos_page = (AMO_t *) TO_AMO((u64) amos_page);
 	}
 
+	/* clear xpc_vars */
 	memset(xpc_vars, 0, sizeof(struct xpc_vars));
 
-	/*
-	 * Place the XPC per partition specific variables on the cache line
-	 * following the XPC variables structure.
-	 */
-	next_cl += XPC_VARS_ALIGNED_SIZE;
-	memset((u64 *) next_cl, 0, sizeof(struct xpc_vars_part) *
-							XP_MAX_PARTITIONS);
-	xpc_vars_part = (struct xpc_vars_part *) next_cl;
-	xpc_vars->vars_part_pa = __pa(next_cl);
-
 	xpc_vars->version = XPC_V_VERSION;
 	xpc_vars->act_nasid = cpuid_to_nasid(0);
 	xpc_vars->act_phys_cpuid = cpu_physical_id(0);
+	xpc_vars->vars_part_pa = __pa(xpc_vars_part);
+	xpc_vars->amos_page_pa = ia64_tpa((u64) amos_page);
 	xpc_vars->amos_page = amos_page;  /* save for next load of XPC */
 
 
-	/*
-	 * Initialize the activation related AMO variables.
-	 */
-	xpc_vars->act_amos = xpc_IPI_init(XP_MAX_PARTITIONS);
-	for (i = 1; i < XP_NASID_MASK_WORDS; i++) {
-		xpc_IPI_init(i + XP_MAX_PARTITIONS);
+	/* clear xpc_vars_part */
+	memset((u64 *) xpc_vars_part, 0, sizeof(struct xpc_vars_part) *
+							XP_MAX_PARTITIONS);
+
+	/* initialize the activate IRQ related AMO variables */
+	for (i = 0; i < xp_nasid_mask_words; i++) {
+		(void) xpc_IPI_init(XPC_ACTIVATE_IRQ_AMOS + i);
 	}
-	/* export AMO page's physical address to other partitions */
-	xpc_vars->amos_page_pa = ia64_tpa((u64) xpc_vars->amos_page);
+
+	/* initialize the engaged remote partitions related AMO variables */
+	(void) xpc_IPI_init(XPC_ENGAGED_PARTITIONS_AMO);
+	(void) xpc_IPI_init(XPC_DISENGAGE_REQUEST_AMO);
+
+	/* timestamp of when reserved page was setup by XPC */
+	rp->stamp = CURRENT_TIME;
 
 	/*
 	 * This signifies to the remote partition that our reserved
@@ -387,6 +408,11 @@ xpc_check_remote_hb(void)
 	remote_vars = (struct xpc_vars *) xpc_remote_copy_buffer;
 
 	for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
+
+		if (xpc_exiting) {
+			break;
+		}
+
 		if (partid == sn_partition_id) {
 			continue;
 		}
@@ -401,7 +427,7 @@ xpc_check_remote_hb(void)
 		/* pull the remote_hb cache line */
 		bres = xp_bte_copy(part->remote_vars_pa,
 					ia64_tpa((u64) remote_vars),
-					XPC_VARS_ALIGNED_SIZE,
+					XPC_RP_VARS_SIZE,
 					(BTE_NOTIFY | BTE_WACQUIRE), NULL);
 		if (bres != BTE_SUCCESS) {
 			XPC_DEACTIVATE_PARTITION(part,
@@ -417,7 +443,7 @@ xpc_check_remote_hb(void)
 
 		if (((remote_vars->heartbeat == part->last_heartbeat) &&
 			(remote_vars->kdb_status == 0)) ||
-			     !XPC_HB_ALLOWED(sn_partition_id, remote_vars)) {
+			     !xpc_hb_allowed(sn_partition_id, remote_vars)) {
 
 			XPC_DEACTIVATE_PARTITION(part, xpcNoHeartbeat);
 			continue;
@@ -429,31 +455,31 @@ xpc_check_remote_hb(void)
 
 
 /*
- * Get a copy of the remote partition's rsvd page.
+ * Get a copy of a portion of the remote partition's rsvd page.
  *
  * remote_rp points to a buffer that is cacheline aligned for BTE copies and
- * assumed to be of size XPC_RSVD_PAGE_ALIGNED_SIZE.
+ * is large enough to contain a copy of their reserved page header and
+ * part_nasids mask.
  */
 static enum xpc_retval
 xpc_get_remote_rp(int nasid, u64 *discovered_nasids,
-		struct xpc_rsvd_page *remote_rp, u64 *remote_rsvd_page_pa)
+		struct xpc_rsvd_page *remote_rp, u64 *remote_rp_pa)
 {
 	int bres, i;
 
 
 	/* get the reserved page's physical address */
 
-	*remote_rsvd_page_pa = xpc_get_rsvd_page_pa(nasid, (u64) remote_rp,
-						XPC_RSVD_PAGE_ALIGNED_SIZE);
-	if (*remote_rsvd_page_pa == 0) {
+	*remote_rp_pa = xpc_get_rsvd_page_pa(nasid);
+	if (*remote_rp_pa == 0) {
 		return xpcNoRsvdPageAddr;
 	}
 
 
-	/* pull over the reserved page structure */
+	/* pull over the reserved page header and part_nasids mask */
 
-	bres = xp_bte_copy(*remote_rsvd_page_pa, ia64_tpa((u64) remote_rp),
-				XPC_RSVD_PAGE_ALIGNED_SIZE,
+	bres = xp_bte_copy(*remote_rp_pa, ia64_tpa((u64) remote_rp),
+				XPC_RP_HEADER_SIZE + xp_nasid_mask_bytes,
 				(BTE_NOTIFY | BTE_WACQUIRE), NULL);
 	if (bres != BTE_SUCCESS) {
 		return xpc_map_bte_errors(bres);
@@ -461,8 +487,11 @@ xpc_get_remote_rp(int nasid, u64 *discovered_nasids,
 
 
 	if (discovered_nasids != NULL) {
-		for (i = 0; i < XP_NASID_MASK_WORDS; i++) {
-			discovered_nasids[i] |= remote_rp->part_nasids[i];
+		u64 *remote_part_nasids = XPC_RP_PART_NASIDS(remote_rp);
+
+
+		for (i = 0; i < xp_nasid_mask_words; i++) {
+			discovered_nasids[i] |= remote_part_nasids[i];
 		}
 	}
 
@@ -489,10 +518,10 @@ xpc_get_remote_rp(int nasid, u64 *discovered_nasids,
 
 
 /*
- * Get a copy of the remote partition's XPC variables.
+ * Get a copy of the remote partition's XPC variables from the reserved page.
  *
  * remote_vars points to a buffer that is cacheline aligned for BTE copies and
- * assumed to be of size XPC_VARS_ALIGNED_SIZE.
+ * assumed to be of size XPC_RP_VARS_SIZE.
  */
 static enum xpc_retval
 xpc_get_remote_vars(u64 remote_vars_pa, struct xpc_vars *remote_vars)
@@ -508,7 +537,7 @@ xpc_get_remote_vars(u64 remote_vars_pa, struct xpc_vars *remote_vars)
 	/* pull over the cross partition variables */
 
 	bres = xp_bte_copy(remote_vars_pa, ia64_tpa((u64) remote_vars),
-				XPC_VARS_ALIGNED_SIZE,
+				XPC_RP_VARS_SIZE,
 				(BTE_NOTIFY | BTE_WACQUIRE), NULL);
 	if (bres != BTE_SUCCESS) {
 		return xpc_map_bte_errors(bres);
@@ -524,7 +553,56 @@ xpc_get_remote_vars(u64 remote_vars_pa, struct xpc_vars *remote_vars)
 
 
 /*
- * Prior code has determine the nasid which generated an IPI.  Inspect
+ * Update the remote partition's info.
+ */
+static void
+xpc_update_partition_info(struct xpc_partition *part, u8 remote_rp_version,
+		struct timespec *remote_rp_stamp, u64 remote_rp_pa,
+		u64 remote_vars_pa, struct xpc_vars *remote_vars)
+{
+	part->remote_rp_version = remote_rp_version;
+	dev_dbg(xpc_part, "  remote_rp_version = 0x%016lx\n",
+		part->remote_rp_version);
+
+	part->remote_rp_stamp = *remote_rp_stamp;
+	dev_dbg(xpc_part, "  remote_rp_stamp (tv_sec = 0x%lx tv_nsec = 0x%lx\n",
+		part->remote_rp_stamp.tv_sec, part->remote_rp_stamp.tv_nsec);
+
+	part->remote_rp_pa = remote_rp_pa;
+	dev_dbg(xpc_part, "  remote_rp_pa = 0x%016lx\n", part->remote_rp_pa);
+
+	part->remote_vars_pa = remote_vars_pa;
+	dev_dbg(xpc_part, "  remote_vars_pa = 0x%016lx\n",
+		part->remote_vars_pa);
+
+	part->last_heartbeat = remote_vars->heartbeat;
+	dev_dbg(xpc_part, "  last_heartbeat = 0x%016lx\n",
+		part->last_heartbeat);
+
+	part->remote_vars_part_pa = remote_vars->vars_part_pa;
+	dev_dbg(xpc_part, "  remote_vars_part_pa = 0x%016lx\n",
+		part->remote_vars_part_pa);
+
+	part->remote_act_nasid = remote_vars->act_nasid;
+	dev_dbg(xpc_part, "  remote_act_nasid = 0x%x\n",
+		part->remote_act_nasid);
+
+	part->remote_act_phys_cpuid = remote_vars->act_phys_cpuid;
+	dev_dbg(xpc_part, "  remote_act_phys_cpuid = 0x%x\n",
+		part->remote_act_phys_cpuid);
+
+	part->remote_amos_page_pa = remote_vars->amos_page_pa;
+	dev_dbg(xpc_part, "  remote_amos_page_pa = 0x%lx\n",
+		part->remote_amos_page_pa);
+
+	part->remote_vars_version = remote_vars->version;
+	dev_dbg(xpc_part, "  remote_vars_version = 0x%x\n",
+		part->remote_vars_version);
+}
+
+
+/*
+ * Prior code has determined the nasid which generated an IPI.  Inspect
  * that nasid to determine if its partition needs to be activated or
  * deactivated.
  *
@@ -542,8 +620,12 @@ xpc_identify_act_IRQ_req(int nasid)
 {
 	struct xpc_rsvd_page *remote_rp;
 	struct xpc_vars *remote_vars;
-	u64 remote_rsvd_page_pa;
+	u64 remote_rp_pa;
 	u64 remote_vars_pa;
+	int remote_rp_version;
+	int reactivate = 0;
+	int stamp_diff;
+	struct timespec remote_rp_stamp = { 0, 0 };
 	partid_t partid;
 	struct xpc_partition *part;
 	enum xpc_retval ret;
@@ -553,7 +635,7 @@ xpc_identify_act_IRQ_req(int nasid)
 
 	remote_rp = (struct xpc_rsvd_page *) xpc_remote_copy_buffer;
 
-	ret = xpc_get_remote_rp(nasid, NULL, remote_rp, &remote_rsvd_page_pa);
+	ret = xpc_get_remote_rp(nasid, NULL, remote_rp, &remote_rp_pa);
 	if (ret != xpcSuccess) {
 		dev_warn(xpc_part, "unable to get reserved page from nasid %d, "
 			"which sent interrupt, reason=%d\n", nasid, ret);
@@ -561,6 +643,10 @@ xpc_identify_act_IRQ_req(int nasid)
 	}
 
 	remote_vars_pa = remote_rp->vars_pa;
+	remote_rp_version = remote_rp->version;
+	if (XPC_SUPPORTS_RP_STAMP(remote_rp_version)) {
+		remote_rp_stamp = remote_rp->stamp;
+	}
 	partid = remote_rp->partid;
 	part = &xpc_partitions[partid];
 
@@ -586,44 +672,117 @@ xpc_identify_act_IRQ_req(int nasid)
 		"%ld:0x%lx\n", (int) nasid, (int) partid, part->act_IRQ_rcvd,
 		remote_vars->heartbeat, remote_vars->heartbeating_to_mask);
 
+	if (xpc_partition_disengaged(part) &&
+					part->act_state == XPC_P_INACTIVE) {
 
-	if (part->act_state == XPC_P_INACTIVE) {
+		xpc_update_partition_info(part, remote_rp_version,
+					&remote_rp_stamp, remote_rp_pa,
+					remote_vars_pa, remote_vars);
 
-		part->remote_rp_pa = remote_rsvd_page_pa;
-		dev_dbg(xpc_part, "  remote_rp_pa = 0x%016lx\n",
-			part->remote_rp_pa);
-
-		part->remote_vars_pa = remote_vars_pa;
-		dev_dbg(xpc_part, "  remote_vars_pa = 0x%016lx\n",
-			part->remote_vars_pa);
-
-		part->last_heartbeat = remote_vars->heartbeat;
-		dev_dbg(xpc_part, "  last_heartbeat = 0x%016lx\n",
-			part->last_heartbeat);
-
-		part->remote_vars_part_pa = remote_vars->vars_part_pa;
-		dev_dbg(xpc_part, "  remote_vars_part_pa = 0x%016lx\n",
-			part->remote_vars_part_pa);
-
-		part->remote_act_nasid = remote_vars->act_nasid;
-		dev_dbg(xpc_part, "  remote_act_nasid = 0x%x\n",
-			part->remote_act_nasid);
-
-		part->remote_act_phys_cpuid = remote_vars->act_phys_cpuid;
-		dev_dbg(xpc_part, "  remote_act_phys_cpuid = 0x%x\n",
-			part->remote_act_phys_cpuid);
-
-		part->remote_amos_page_pa = remote_vars->amos_page_pa;
-		dev_dbg(xpc_part, "  remote_amos_page_pa = 0x%lx\n",
-			part->remote_amos_page_pa);
+		if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version)) {
+			if (xpc_partition_disengage_requested(1UL << partid)) {
+				/*
+				 * Other side is waiting on us to disengage,
+				 * even though we already have.
+				 */
+				return;
+			}
+		} else {
+			/* other side doesn't support disengage requests */
+			xpc_clear_partition_disengage_request(1UL << partid);
+		}
 
 		xpc_activate_partition(part);
+		return;
+	}
 
-	} else if (part->remote_amos_page_pa != remote_vars->amos_page_pa ||
-			!XPC_HB_ALLOWED(sn_partition_id, remote_vars)) {
+	DBUG_ON(part->remote_rp_version == 0);
+	DBUG_ON(part->remote_vars_version == 0);
 
+	if (!XPC_SUPPORTS_RP_STAMP(part->remote_rp_version)) {
+		DBUG_ON(XPC_SUPPORTS_DISENGAGE_REQUEST(part->
+							remote_vars_version));
+
+		if (!XPC_SUPPORTS_RP_STAMP(remote_rp_version)) {
+			DBUG_ON(XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->
+								version));
+			/* see if the other side rebooted */
+			if (part->remote_amos_page_pa ==
+				remote_vars->amos_page_pa &&
+					xpc_hb_allowed(sn_partition_id,
+								remote_vars)) {
+				/* doesn't look that way, so ignore the IPI */
+				return;
+			}
+		}
+
+		/*
+		 * Other side rebooted and previous XPC didn't support the
+		 * disengage request, so we don't need to do anything special.
+		 */
+
+		xpc_update_partition_info(part, remote_rp_version,
+						&remote_rp_stamp, remote_rp_pa,
+						remote_vars_pa, remote_vars);
 		part->reactivate_nasid = nasid;
 		XPC_DEACTIVATE_PARTITION(part, xpcReactivating);
+		return;
+	}
+
+	DBUG_ON(!XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version));
+
+	if (!XPC_SUPPORTS_RP_STAMP(remote_rp_version)) {
+		DBUG_ON(!XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->version));
+
+		/*
+		 * Other side rebooted and previous XPC did support the
+		 * disengage request, but the new one doesn't.
+		 */
+
+		xpc_clear_partition_engaged(1UL << partid);
+		xpc_clear_partition_disengage_request(1UL << partid);
+
+		xpc_update_partition_info(part, remote_rp_version,
+						&remote_rp_stamp, remote_rp_pa,
+						remote_vars_pa, remote_vars);
+		reactivate = 1;
+
+	} else {
+		DBUG_ON(!XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->version));
+
+		stamp_diff = xpc_compare_stamps(&part->remote_rp_stamp,
+							&remote_rp_stamp);
+		if (stamp_diff != 0) {
+			DBUG_ON(stamp_diff >= 0);
+
+			/*
+			 * Other side rebooted and the previous XPC did support
+			 * the disengage request, as does the new one.
+			 */
+
+			DBUG_ON(xpc_partition_engaged(1UL << partid));
+			DBUG_ON(xpc_partition_disengage_requested(1UL <<
+								partid));
+
+			xpc_update_partition_info(part, remote_rp_version,
+						&remote_rp_stamp, remote_rp_pa,
+						remote_vars_pa, remote_vars);
+			reactivate = 1;
+		}
+	}
+
+	if (!xpc_partition_disengaged(part)) {
+		/* still waiting on other side to disengage from us */
+		return;
+	}
+
+	if (reactivate) {
+		part->reactivate_nasid = nasid;
+		XPC_DEACTIVATE_PARTITION(part, xpcReactivating);
+
+	} else if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version) &&
+			xpc_partition_disengage_requested(1UL << partid)) {
+		XPC_DEACTIVATE_PARTITION(part, xpcOtherGoingDown);
 	}
 }
 
@@ -643,14 +802,17 @@ xpc_identify_act_IRQ_sender(void)
 	u64 nasid;			/* remote nasid */
 	int n_IRQs_detected = 0;
 	AMO_t *act_amos;
-	struct xpc_rsvd_page *rp = (struct xpc_rsvd_page *) xpc_rsvd_page;
 
 
-	act_amos = xpc_vars->act_amos;
+	act_amos = xpc_vars->amos_page + XPC_ACTIVATE_IRQ_AMOS;
 
 
 	/* scan through act AMO variable looking for non-zero entries */
-	for (word = 0; word < XP_NASID_MASK_WORDS; word++) {
+	for (word = 0; word < xp_nasid_mask_words; word++) {
+
+		if (xpc_exiting) {
+			break;
+		}
 
 		nasid_mask = xpc_IPI_receive(&act_amos[word]);
 		if (nasid_mask == 0) {
@@ -668,7 +830,7 @@ xpc_identify_act_IRQ_sender(void)
 		 * remote nasid in our reserved pages machine mask.
 		 * This is used in the event of module reload.
 		 */
-		rp->mach_nasids[word] |= nasid_mask;
+		xpc_mach_nasids[word] |= nasid_mask;
 
 
 		/* locate the nasid(s) which sent interrupts */
@@ -687,6 +849,55 @@ xpc_identify_act_IRQ_sender(void)
 }
 
 
+/*
+ * See if the other side has responded to a partition disengage request
+ * from us.
+ */
+int
+xpc_partition_disengaged(struct xpc_partition *part)
+{
+	partid_t partid = XPC_PARTID(part);
+	int disengaged;
+
+
+	disengaged = (xpc_partition_engaged(1UL << partid) == 0);
+	if (part->disengage_request_timeout) {
+		if (!disengaged) {
+			if (jiffies < part->disengage_request_timeout) {
+				/* timelimit hasn't been reached yet */
+				return 0;
+			}
+
+			/*
+			 * Other side hasn't responded to our disengage
+			 * request in a timely fashion, so assume it's dead.
+			 */
+
+			xpc_clear_partition_engaged(1UL << partid);
+			disengaged = 1;
+		}
+		part->disengage_request_timeout = 0;
+
+		/* cancel the timer function, provided it's not us */
+		if (!in_interrupt()) {
+			del_singleshot_timer_sync(&part->
+						      disengage_request_timer);
+		}
+
+		DBUG_ON(part->act_state != XPC_P_DEACTIVATING &&
+					part->act_state != XPC_P_INACTIVE);
+		if (part->act_state != XPC_P_INACTIVE) {
+			xpc_wakeup_channel_mgr(part);
+		}
+
+		if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version)) {
+			xpc_cancel_partition_disengage_request(part);
+		}
+	}
+	return disengaged;
+}
+
+
 /*
  * Mark specified partition as active.
  */
@@ -721,7 +932,6 @@ xpc_deactivate_partition(const int line, struct xpc_partition *part,
 				enum xpc_retval reason)
 {
 	unsigned long irq_flags;
-	partid_t partid = XPC_PARTID(part);
 
 
 	spin_lock_irqsave(&part->act_lock, irq_flags);
@@ -749,17 +959,27 @@ xpc_deactivate_partition(const int line, struct xpc_partition *part,
 
 	spin_unlock_irqrestore(&part->act_lock, irq_flags);
 
-	XPC_DISALLOW_HB(partid, xpc_vars);
+	if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version)) {
+		xpc_request_partition_disengage(part);
+		xpc_IPI_send_disengage(part);
 
-	dev_dbg(xpc_part, "bringing partition %d down, reason = %d\n", partid,
-		reason);
+		/* set a timelimit on the disengage request */
+		part->disengage_request_timeout = jiffies +
+					(xpc_disengage_request_timelimit * HZ);
+		part->disengage_request_timer.expires =
+					part->disengage_request_timeout;
+		add_timer(&part->disengage_request_timer);
+	}
 
-	xpc_partition_down(part, reason);
+	dev_dbg(xpc_part, "bringing partition %d down, reason = %d\n",
+		XPC_PARTID(part), reason);
+
+	xpc_partition_going_down(part, reason);
 }
 
 
 /*
- * Mark specified partition as active.
+ * Mark specified partition as inactive.
  */
 void
 xpc_mark_partition_inactive(struct xpc_partition *part)
@@ -792,9 +1012,10 @@ xpc_discovery(void)
 	void *remote_rp_base;
 	struct xpc_rsvd_page *remote_rp;
 	struct xpc_vars *remote_vars;
-	u64 remote_rsvd_page_pa;
+	u64 remote_rp_pa;
 	u64 remote_vars_pa;
 	int region;
+	int region_size;
 	int max_regions;
 	int nasid;
 	struct xpc_rsvd_page *rp;
@@ -804,7 +1025,8 @@ xpc_discovery(void)
 	enum xpc_retval ret;
 
 
-	remote_rp = xpc_kmalloc_cacheline_aligned(XPC_RSVD_PAGE_ALIGNED_SIZE,
+	remote_rp = xpc_kmalloc_cacheline_aligned(XPC_RP_HEADER_SIZE +
+						xp_nasid_mask_bytes,
 						GFP_KERNEL, &remote_rp_base);
 	if (remote_rp == NULL) {
 		return;
@@ -812,13 +1034,13 @@ xpc_discovery(void)
 	remote_vars = (struct xpc_vars *) remote_rp;
 
 
-	discovered_nasids = kmalloc(sizeof(u64) * XP_NASID_MASK_WORDS,
+	discovered_nasids = kmalloc(sizeof(u64) * xp_nasid_mask_words,
 							GFP_KERNEL);
 	if (discovered_nasids == NULL) {
 		kfree(remote_rp_base);
 		return;
 	}
-	memset(discovered_nasids, 0, sizeof(u64) * XP_NASID_MASK_WORDS);
+	memset(discovered_nasids, 0, sizeof(u64) * xp_nasid_mask_words);
 
 	rp = (struct xpc_rsvd_page *) xpc_rsvd_page;
 
@@ -827,11 +1049,19 @@ xpc_discovery(void)
 	 * nodes that can comprise an access protection grouping. The access
 	 * protection is in regards to memory, IOI and IPI.
 	 */
-//>>> move the next two #defines into either include/asm-ia64/sn/arch.h or
-//>>> include/asm-ia64/sn/addrs.h
-#define SH1_MAX_REGIONS		64
-#define SH2_MAX_REGIONS		256
-	max_regions = is_shub2() ? SH2_MAX_REGIONS : SH1_MAX_REGIONS;
+	max_regions = 64;
+	region_size = sn_region_size;
+
+	switch (region_size) {
+	case 128:
+		max_regions *= 2;
+	case 64:
+		max_regions *= 2;
+	case 32:
+		max_regions *= 2;
+		region_size = 16;
+		DBUG_ON(!is_shub2());
+	}
 
 	for (region = 0; region < max_regions; region++) {
 
@@ -841,8 +1071,8 @@ xpc_discovery(void)
 
 		dev_dbg(xpc_part, "searching region %d\n", region);
 
-		for (nasid = (region * sn_region_size * 2);
-		     nasid < ((region + 1) * sn_region_size * 2);
+		for (nasid = (region * region_size * 2);
+		     nasid < ((region + 1) * region_size * 2);
 		     nasid += 2) {
 
 			if ((volatile int) xpc_exiting) {
@@ -852,14 +1082,14 @@ xpc_discovery(void)
 			dev_dbg(xpc_part, "checking nasid %d\n", nasid);
 
 
-			if (XPC_NASID_IN_ARRAY(nasid, rp->part_nasids)) {
+			if (XPC_NASID_IN_ARRAY(nasid, xpc_part_nasids)) {
 				dev_dbg(xpc_part, "PROM indicates Nasid %d is "
 					"part of the local partition; skipping "
 					"region\n", nasid);
 				break;
 			}
 
-			if (!(XPC_NASID_IN_ARRAY(nasid, rp->mach_nasids))) {
+			if (!(XPC_NASID_IN_ARRAY(nasid, xpc_mach_nasids))) {
 				dev_dbg(xpc_part, "PROM indicates Nasid %d was "
 					"not on Numa-Link network at reset\n",
 					nasid);
@@ -877,7 +1107,7 @@ xpc_discovery(void)
 			/* pull over the reserved page structure */
 
 			ret = xpc_get_remote_rp(nasid, discovered_nasids,
-					      remote_rp, &remote_rsvd_page_pa);
+					      remote_rp, &remote_rp_pa);
 			if (ret != xpcSuccess) {
 				dev_dbg(xpc_part, "unable to get reserved page "
 					"from nasid %d, reason=%d\n", nasid,
@@ -948,6 +1178,13 @@ xpc_discovery(void)
 				remote_vars->act_nasid,
 				remote_vars->act_phys_cpuid);
 
+			if (XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->
+								version)) {
+				part->remote_amos_page_pa =
+						remote_vars->amos_page_pa;
+				xpc_mark_partition_disengaged(part);
+				xpc_cancel_partition_disengage_request(part);
+			}
 			xpc_IPI_send_activate(remote_vars);
 		}
 	}
@@ -974,12 +1211,12 @@ xpc_initiate_partid_to_nasids(partid_t partid, void *nasid_mask)
 		return xpcPartitionDown;
 	}
 
-	part_nasid_pa = part->remote_rp_pa +
-		(u64) &((struct xpc_rsvd_page *) 0)->part_nasids;
+	memset(nasid_mask, 0, XP_NASID_MASK_BYTES);
+
+	part_nasid_pa = (u64) XPC_RP_PART_NASIDS(part->remote_rp_pa);
 
 	bte_res = xp_bte_copy(part_nasid_pa, ia64_tpa((u64) nasid_mask),
-				L1_CACHE_ALIGN(XP_NASID_MASK_BYTES),
-				(BTE_NOTIFY | BTE_WACQUIRE), NULL);
+			xp_nasid_mask_bytes, (BTE_NOTIFY | BTE_WACQUIRE), NULL);
 
 	return xpc_map_bte_errors(bte_res);
 }