xpc_partition.c

linux 内核源代码

 */
void
xpc_check_remote_hb(void)
{
	struct xpc_vars *remote_vars;
	struct xpc_partition *part;
	partid_t partid;
	bte_result_t bres;


	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;
		}

		part = &xpc_partitions[partid];

		if (part->act_state == XPC_P_INACTIVE ||
				part->act_state == XPC_P_DEACTIVATING) {
			continue;
		}

		/* pull the remote_hb cache line */
		bres = xp_bte_copy(part->remote_vars_pa,
					(u64) remote_vars,
					XPC_RP_VARS_SIZE,
					(BTE_NOTIFY | BTE_WACQUIRE), NULL);
		if (bres != BTE_SUCCESS) {
			XPC_DEACTIVATE_PARTITION(part,
						xpc_map_bte_errors(bres));
			continue;
		}

		dev_dbg(xpc_part, "partid = %d, heartbeat = %ld, last_heartbeat"
			" = %ld, heartbeat_offline = %ld, HB_mask = 0x%lx\n",
			partid, remote_vars->heartbeat, part->last_heartbeat,
			remote_vars->heartbeat_offline,
			remote_vars->heartbeating_to_mask);

		if (((remote_vars->heartbeat == part->last_heartbeat) &&
			(remote_vars->heartbeat_offline == 0)) ||
			     !xpc_hb_allowed(sn_partition_id, remote_vars)) {

			XPC_DEACTIVATE_PARTITION(part, xpcNoHeartbeat);
			continue;
		}

		part->last_heartbeat = remote_vars->heartbeat;
	}
}


/*
 * 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
 * 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_rp_pa)
{
	int bres, i;


	/* get the reserved page's physical address */

	*remote_rp_pa = xpc_get_rsvd_page_pa(nasid);
	if (*remote_rp_pa == 0) {
		return xpcNoRsvdPageAddr;
	}


	/* pull over the reserved page header and part_nasids mask */
	bres = xp_bte_copy(*remote_rp_pa, (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);
	}


	if (discovered_nasids != NULL) {
		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];
		}
	}


	/* check that the partid is for another partition */

	if (remote_rp->partid < 1 ||
				remote_rp->partid > (XP_MAX_PARTITIONS - 1)) {
		return xpcInvalidPartid;
	}

	if (remote_rp->partid == sn_partition_id) {
		return xpcLocalPartid;
	}


	if (XPC_VERSION_MAJOR(remote_rp->version) !=
					XPC_VERSION_MAJOR(XPC_RP_VERSION)) {
		return xpcBadVersion;
	}

	return xpcSuccess;
}


/*
 * 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_RP_VARS_SIZE.
 */
static enum xpc_retval
xpc_get_remote_vars(u64 remote_vars_pa, struct xpc_vars *remote_vars)
{
	int bres;


	if (remote_vars_pa == 0) {
		return xpcVarsNotSet;
	}

	/* pull over the cross partition variables */
	bres = xp_bte_copy(remote_vars_pa, (u64) remote_vars, XPC_RP_VARS_SIZE,
				(BTE_NOTIFY | BTE_WACQUIRE), NULL);
	if (bres != BTE_SUCCESS) {
		return xpc_map_bte_errors(bres);
	}

	if (XPC_VERSION_MAJOR(remote_vars->version) !=
					XPC_VERSION_MAJOR(XPC_V_VERSION)) {
		return xpcBadVersion;
	}

	return xpcSuccess;
}


/*
 * 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%016x\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.
 *
 * A partition is consider "awaiting activation" if our partition
 * flags indicate it is not active and it has a heartbeat.  A
 * partition is considered "awaiting deactivation" if our partition
 * flags indicate it is active but it has no heartbeat or it is not
 * sending its heartbeat to us.
 *
 * To determine the heartbeat, the remote nasid must have a properly
 * initialized reserved page.
 */
static void
xpc_identify_act_IRQ_req(int nasid)
{
	struct xpc_rsvd_page *remote_rp;
	struct xpc_vars *remote_vars;
	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;


	/* pull over the reserved page structure */

	remote_rp = (struct xpc_rsvd_page *) xpc_remote_copy_buffer;

	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);
		return;
	}

	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];


	/* pull over the cross partition variables */

	remote_vars = (struct xpc_vars *) xpc_remote_copy_buffer;

	ret = xpc_get_remote_vars(remote_vars_pa, remote_vars);
	if (ret != xpcSuccess) {

		dev_warn(xpc_part, "unable to get XPC variables from nasid %d, "
			"which sent interrupt, reason=%d\n", nasid, ret);

		XPC_DEACTIVATE_PARTITION(part, ret);
		return;
	}


	part->act_IRQ_rcvd++;

	dev_dbg(xpc_part, "partid for nasid %d is %d; IRQs = %d; HB = "
		"%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) {

		xpc_update_partition_info(part, remote_rp_version,
					&remote_rp_stamp, remote_rp_pa,
					remote_vars_pa, remote_vars);

		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;
	}

	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 (part->disengage_request_timeout > 0 &&
					!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);
	}
}


/*
 * Loop through the activation AMO variables and process any bits
 * which are set.  Each bit indicates a nasid sending a partition
 * activation or deactivation request.
 *
 * Return #of IRQs detected.
 */
int
xpc_identify_act_IRQ_sender(void)
{
	int word, bit;
	u64 nasid_mask;
	u64 nasid;			/* remote nasid */
	int n_IRQs_detected = 0;
	AMO_t *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++) {

		if (xpc_exiting) {
			break;