drivers/scsi/libfc/fc_npiv.c

   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
  26 /**
  27  * fc_vport_create() - Create a new NPIV vport instance
  28  * @vport: fc_vport structure from scsi_transport_fc
  29  * @privsize: driver private data size to allocate along with the Scsi_Host
  30  */
  31
  32 struct fc_lport *libfc_vport_create(struct fc_vport *vport, int privsize)
  33 {
  34         struct Scsi_Host *shost = vport_to_shost(vport);
  35         struct fc_lport *n_port = shost_priv(shost);
  36         struct fc_lport *vn_port;
  37
  38         vn_port = libfc_host_alloc(shost->hostt, privsize);
  39         if (!vn_port)
  40                 return vn_port;
  41
  42         vn_port->vport = vport;
  43         vport->dd_data = vn_port;
  44
  45         mutex_lock(&n_port->lp_mutex);
  46         list_add_tail(&vn_port->list, &n_port->vports);
  47         mutex_unlock(&n_port->lp_mutex);
  48
  49         return vn_port;
  50 }
  51 EXPORT_SYMBOL(libfc_vport_create);
  52
  53 /**
  54  * fc_vport_id_lookup() - find NPIV lport that matches a given fabric ID
  55  * @n_port: Top level N_Port which may have multiple NPIV VN_Ports
  56  * @port_id: Fabric ID to find a match for
  57  *
  58  * Returns: matching lport pointer or NULL if there is no match
  59  */
  60 struct fc_lport *fc_vport_id_lookup(struct fc_lport *n_port, u32 port_id)
  61 {
  62         struct fc_lport *lport = NULL;
  63         struct fc_lport *vn_port;
  64
  65         if (n_port->port_id == port_id)
  66                 return n_port;
  67
  68         if (port_id == FC_FID_FLOGI)
  69                 return n_port;          /* for point-to-point */
  70
  71         mutex_lock(&n_port->lp_mutex);
  72         list_for_each_entry(vn_port, &n_port->vports, list) {
  73                 if (vn_port->port_id == port_id) {
  74                         lport = vn_port;
  75                         break;
  76                 }
  77         }
  78         mutex_unlock(&n_port->lp_mutex);
  79
  80         return lport;
  81 }
  82 EXPORT_SYMBOL(fc_vport_id_lookup);
  83
  84 /*
  85  * When setting the link state of vports during an lport state change, it's
  86  * necessary to hold the lp_mutex of both the N_Port and the VN_Port.
  87  * This tells the lockdep engine to treat the nested locking of the VN_Port
  88  * as a different lock class.
  89  */
  90 enum libfc_lport_mutex_class {
  91         LPORT_MUTEX_NORMAL = 0,
  92         LPORT_MUTEX_VN_PORT = 1,
  93 };
  94
  95 /**
  96  * __fc_vport_setlink() - update link and status on a VN_Port
  97  * @n_port: parent N_Port
  98  * @vn_port: VN_Port to update
  99  *
 100  * Locking: must be called with both the N_Port and VN_Port lp_mutex held
 101  */
 102 static void __fc_vport_setlink(struct fc_lport *n_port,
 103                                struct fc_lport *vn_port)
 104 {
 105         struct fc_vport *vport = vn_port->vport;
 106
 107         if (vn_port->state == LPORT_ST_DISABLED)
 108                 return;
 109
 110         if (n_port->state == LPORT_ST_READY) {
 111                 if (n_port->npiv_enabled) {
 112                         fc_vport_set_state(vport, FC_VPORT_INITIALIZING);
 113                         __fc_linkup(vn_port);
 114                 } else {
 115                         fc_vport_set_state(vport, FC_VPORT_NO_FABRIC_SUPP);
 116                         __fc_linkdown(vn_port);
 117                 }
 118         } else {
 119                 fc_vport_set_state(vport, FC_VPORT_LINKDOWN);
 120                 __fc_linkdown(vn_port);
 121         }
 122 }
 123
 124 /**
 125  * fc_vport_setlink() - update link and status on a VN_Port
 126  * @vn_port: virtual port to update
 127  */
 128 void fc_vport_setlink(struct fc_lport *vn_port)
 129 {
 130         struct fc_vport *vport = vn_port->vport;
 131         struct Scsi_Host *shost = vport_to_shost(vport);
 132         struct fc_lport *n_port = shost_priv(shost);
 133
 134         mutex_lock(&n_port->lp_mutex);
 135         mutex_lock_nested(&vn_port->lp_mutex, LPORT_MUTEX_VN_PORT);
 136         __fc_vport_setlink(n_port, vn_port);
 137         mutex_unlock(&vn_port->lp_mutex);
 138         mutex_unlock(&n_port->lp_mutex);
 139 }
 140 EXPORT_SYMBOL(fc_vport_setlink);
 141
 142 /**
 143  * fc_vports_linkchange() - change the link state of all vports
 144  * @n_port: Parent N_Port that has changed state
 145  *
 146  * Locking: called with the n_port lp_mutex held
 147  */
 148 void fc_vports_linkchange(struct fc_lport *n_port)
 149 {
 150         struct fc_lport *vn_port;
 151
 152         list_for_each_entry(vn_port, &n_port->vports, list) {
 153                 mutex_lock_nested(&vn_port->lp_mutex, LPORT_MUTEX_VN_PORT);
 154                 __fc_vport_setlink(n_port, vn_port);
 155                 mutex_unlock(&vn_port->lp_mutex);
 156         }
 157 }
 158