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                 goto err_out;
  41         if (fc_exch_mgr_list_clone(n_port, vn_port))
  42                 goto err_put;
  43
  44         vn_port->vport = vport;
  45         vport->dd_data = vn_port;
  46
  47         mutex_lock(&n_port->lp_mutex);
  48         list_add_tail(&vn_port->list, &n_port->vports);
  49         mutex_unlock(&n_port->lp_mutex);
  50
  51         return vn_port;
  52
  53 err_put:
  54         scsi_host_put(vn_port->host);
  55 err_out:
  56         return NULL;
  57 }
  58 EXPORT_SYMBOL(libfc_vport_create);
  59
  60 /**
  61  * fc_vport_id_lookup() - find NPIV lport that matches a given fabric ID
  62  * @n_port: Top level N_Port which may have multiple NPIV VN_Ports
  63  * @port_id: Fabric ID to find a match for
  64  *
  65  * Returns: matching lport pointer or NULL if there is no match
  66  */
  67 struct fc_lport *fc_vport_id_lookup(struct fc_lport *n_port, u32 port_id)
  68 {
  69         struct fc_lport *lport = NULL;
  70         struct fc_lport *vn_port;
  71
  72         if (fc_host_port_id(n_port->host) == port_id)
  73                 return n_port;
  74
  75         mutex_lock(&n_port->lp_mutex);
  76         list_for_each_entry(vn_port, &n_port->vports, list) {
  77                 if (fc_host_port_id(vn_port->host) == port_id) {
  78                         lport = vn_port;
  79                         break;
  80                 }
  81         }
  82         mutex_unlock(&n_port->lp_mutex);
  83
  84         return lport;
  85 }
  86
  87 /*
  88  * When setting the link state of vports during an lport state change, it's
  89  * necessary to hold the lp_mutex of both the N_Port and the VN_Port.
  90  * This tells the lockdep engine to treat the nested locking of the VN_Port
  91  * as a different lock class.
  92  */
  93 enum libfc_lport_mutex_class {
  94         LPORT_MUTEX_NORMAL = 0,
  95         LPORT_MUTEX_VN_PORT = 1,
  96 };
  97
  98 /**
  99  * __fc_vport_setlink() - update link and status on a VN_Port
 100  * @n_port: parent N_Port
 101  * @vn_port: VN_Port to update
 102  *
 103  * Locking: must be called with both the N_Port and VN_Port lp_mutex held
 104  */
 105 static void __fc_vport_setlink(struct fc_lport *n_port,
 106                                struct fc_lport *vn_port)
 107 {
 108         struct fc_vport *vport = vn_port->vport;
 109
 110         if (vn_port->state == LPORT_ST_DISABLED)
 111                 return;
 112
 113         if (n_port->state == LPORT_ST_READY) {
 114                 if (n_port->npiv_enabled) {
 115                         fc_vport_set_state(vport, FC_VPORT_INITIALIZING);
 116                         __fc_linkup(vn_port);
 117                 } else {
 118                         fc_vport_set_state(vport, FC_VPORT_NO_FABRIC_SUPP);
 119                         __fc_linkdown(vn_port);
 120                 }
 121         } else {
 122                 fc_vport_set_state(vport, FC_VPORT_LINKDOWN);
 123                 __fc_linkdown(vn_port);
 124         }
 125 }
 126
 127 /**
 128  * fc_vport_setlink() - update link and status on a VN_Port
 129  * @vn_port: virtual port to update
 130  */
 131 void fc_vport_setlink(struct fc_lport *vn_port)
 132 {
 133         struct fc_vport *vport = vn_port->vport;
 134         struct Scsi_Host *shost = vport_to_shost(vport);
 135         struct fc_lport *n_port = shost_priv(shost);
 136
 137         mutex_lock(&n_port->lp_mutex);
 138         mutex_lock_nested(&vn_port->lp_mutex, LPORT_MUTEX_VN_PORT);
 139         __fc_vport_setlink(n_port, vn_port);
 140         mutex_unlock(&vn_port->lp_mutex);
 141         mutex_unlock(&n_port->lp_mutex);
 142 }
 143 EXPORT_SYMBOL(fc_vport_setlink);
 144
 145 /**
 146  * fc_vports_linkchange() - change the link state of all vports
 147  * @n_port: Parent N_Port that has changed state
 148  *
 149  * Locking: called with the n_port lp_mutex held
 150  */
 151 void fc_vports_linkchange(struct fc_lport *n_port)
 152 {
 153         struct fc_lport *vn_port;
 154
 155         list_for_each_entry(vn_port, &n_port->vports, list) {
 156                 mutex_lock_nested(&vn_port->lp_mutex, LPORT_MUTEX_VN_PORT);
 157                 __fc_vport_setlink(n_port, vn_port);
 158                 mutex_unlock(&vn_port->lp_mutex);
 159         }
 160 }
 161