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 #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