xref: /linux/drivers/scsi/libfc/fc_npiv.c (revision c0c914eca7f251c70facc37dfebeaf176601918d)
1 /*
2  * Copyright(c) 2009 Intel Corporation. All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms and conditions of the GNU General Public License,
6  * version 2, as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope it will be useful, but WITHOUT
9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
11  * more details.
12  *
13  * You should have received a copy of the GNU General Public License along with
14  * this program; if not, write to the Free Software Foundation, Inc.,
15  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
16  *
17  * Maintained at www.Open-FCoE.org
18  */
19 
20 /*
21  * NPIV VN_Port helper functions for libfc
22  */
23 
24 #include <scsi/libfc.h>
25 #include <linux/export.h>
26 
27 /**
28  * libfc_vport_create() - Create a new NPIV vport instance
29  * @vport: fc_vport structure from scsi_transport_fc
30  * @privsize: driver private data size to allocate along with the Scsi_Host
31  */
32 
33 struct fc_lport *libfc_vport_create(struct fc_vport *vport, int privsize)
34 {
35 	struct Scsi_Host *shost = vport_to_shost(vport);
36 	struct fc_lport *n_port = shost_priv(shost);
37 	struct fc_lport *vn_port;
38 
39 	vn_port = libfc_host_alloc(shost->hostt, privsize);
40 	if (!vn_port)
41 		return vn_port;
42 
43 	vn_port->vport = vport;
44 	vport->dd_data = vn_port;
45 
46 	mutex_lock(&n_port->lp_mutex);
47 	list_add_tail(&vn_port->list, &n_port->vports);
48 	mutex_unlock(&n_port->lp_mutex);
49 
50 	return vn_port;
51 }
52 EXPORT_SYMBOL(libfc_vport_create);
53 
54 /**
55  * fc_vport_id_lookup() - find NPIV lport that matches a given fabric ID
56  * @n_port: Top level N_Port which may have multiple NPIV VN_Ports
57  * @port_id: Fabric ID to find a match for
58  *
59  * Returns: matching lport pointer or NULL if there is no match
60  */
61 struct fc_lport *fc_vport_id_lookup(struct fc_lport *n_port, u32 port_id)
62 {
63 	struct fc_lport *lport = NULL;
64 	struct fc_lport *vn_port;
65 
66 	if (n_port->port_id == port_id)
67 		return n_port;
68 
69 	if (port_id == FC_FID_FLOGI)
70 		return n_port;		/* for point-to-point */
71 
72 	mutex_lock(&n_port->lp_mutex);
73 	list_for_each_entry(vn_port, &n_port->vports, list) {
74 		if (vn_port->port_id == port_id) {
75 			lport = vn_port;
76 			break;
77 		}
78 	}
79 	mutex_unlock(&n_port->lp_mutex);
80 
81 	return lport;
82 }
83 EXPORT_SYMBOL(fc_vport_id_lookup);
84 
85 /*
86  * When setting the link state of vports during an lport state change, it's
87  * necessary to hold the lp_mutex of both the N_Port and the VN_Port.
88  * This tells the lockdep engine to treat the nested locking of the VN_Port
89  * as a different lock class.
90  */
91 enum libfc_lport_mutex_class {
92 	LPORT_MUTEX_NORMAL = 0,
93 	LPORT_MUTEX_VN_PORT = 1,
94 };
95 
96 /**
97  * __fc_vport_setlink() - update link and status on a VN_Port
98  * @n_port: parent N_Port
99  * @vn_port: VN_Port to update
100  *
101  * Locking: must be called with both the N_Port and VN_Port lp_mutex held
102  */
103 static void __fc_vport_setlink(struct fc_lport *n_port,
104 			       struct fc_lport *vn_port)
105 {
106 	struct fc_vport *vport = vn_port->vport;
107 
108 	if (vn_port->state == LPORT_ST_DISABLED)
109 		return;
110 
111 	if (n_port->state == LPORT_ST_READY) {
112 		if (n_port->npiv_enabled) {
113 			fc_vport_set_state(vport, FC_VPORT_INITIALIZING);
114 			__fc_linkup(vn_port);
115 		} else {
116 			fc_vport_set_state(vport, FC_VPORT_NO_FABRIC_SUPP);
117 			__fc_linkdown(vn_port);
118 		}
119 	} else {
120 		fc_vport_set_state(vport, FC_VPORT_LINKDOWN);
121 		__fc_linkdown(vn_port);
122 	}
123 }
124 
125 /**
126  * fc_vport_setlink() - update link and status on a VN_Port
127  * @vn_port: virtual port to update
128  */
129 void fc_vport_setlink(struct fc_lport *vn_port)
130 {
131 	struct fc_vport *vport = vn_port->vport;
132 	struct Scsi_Host *shost = vport_to_shost(vport);
133 	struct fc_lport *n_port = shost_priv(shost);
134 
135 	mutex_lock(&n_port->lp_mutex);
136 	mutex_lock_nested(&vn_port->lp_mutex, LPORT_MUTEX_VN_PORT);
137 	__fc_vport_setlink(n_port, vn_port);
138 	mutex_unlock(&vn_port->lp_mutex);
139 	mutex_unlock(&n_port->lp_mutex);
140 }
141 EXPORT_SYMBOL(fc_vport_setlink);
142 
143 /**
144  * fc_vports_linkchange() - change the link state of all vports
145  * @n_port: Parent N_Port that has changed state
146  *
147  * Locking: called with the n_port lp_mutex held
148  */
149 void fc_vports_linkchange(struct fc_lport *n_port)
150 {
151 	struct fc_lport *vn_port;
152 
153 	list_for_each_entry(vn_port, &n_port->vports, list) {
154 		mutex_lock_nested(&vn_port->lp_mutex, LPORT_MUTEX_VN_PORT);
155 		__fc_vport_setlink(n_port, vn_port);
156 		mutex_unlock(&vn_port->lp_mutex);
157 	}
158 }
159 
160