LXR linux/drivers/scsi/libfc/fc

   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
  32struct 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
  53err_put:
  54        scsi_host_put(vn_port->host);
  55err_out:
  56        return NULL;
  57}
  58EXPORT_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 */
  67struct 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 (n_port->port_id == port_id)
  73                return n_port;
  74
  75        if (port_id == FC_FID_FLOGI)
  76                return n_port;          /* for point-to-point */
  77
  78        mutex_lock(&n_port->lp_mutex);
  79        list_for_each_entry(vn_port, &n_port->vports, list) {
  80                if (vn_port->port_id == port_id) {
  81                        lport = vn_port;
  82                        break;
  83                }
  84        }
  85        mutex_unlock(&n_port->lp_mutex);
  86
  87        return lport;
  88}
  89
  90/*
  91 * When setting the link state of vports during an lport state change, it's
  92 * necessary to hold the lp_mutex of both the N_Port and the VN_Port.
  93 * This tells the lockdep engine to treat the nested locking of the VN_Port
  94 * as a different lock class.
  95 */
  96enum libfc_lport_mutex_class {
  97        LPORT_MUTEX_NORMAL = 0,
  98        LPORT_MUTEX_VN_PORT = 1,
  99};
 100
 101/**
 102 * __fc_vport_setlink() - update link and status on a VN_Port
 103 * @n_port: parent N_Port
 104 * @vn_port: VN_Port to update
 105 *
 106 * Locking: must be called with both the N_Port and VN_Port lp_mutex held
 107 */
 108static void __fc_vport_setlink(struct fc_lport *n_port,
 109                               struct fc_lport *vn_port)
 110{
 111        struct fc_vport *vport = vn_port->vport;
 112
 113        if (vn_port->state == LPORT_ST_DISABLED)
 114                return;
 115
 116        if (n_port->state == LPORT_ST_READY) {
 117                if (n_port->npiv_enabled) {
 118                        fc_vport_set_state(vport, FC_VPORT_INITIALIZING);
 119                        __fc_linkup(vn_port);
 120                } else {
 121                        fc_vport_set_state(vport, FC_VPORT_NO_FABRIC_SUPP);
 122                        __fc_linkdown(vn_port);
 123                }
 124        } else {
 125                fc_vport_set_state(vport, FC_VPORT_LINKDOWN);
 126                __fc_linkdown(vn_port);
 127        }
 128}
 129
 130/**
 131 * fc_vport_setlink() - update link and status on a VN_Port
 132 * @vn_port: virtual port to update
 133 */
 134void fc_vport_setlink(struct fc_lport *vn_port)
 135{
 136        struct fc_vport *vport = vn_port->vport;
 137        struct Scsi_Host *shost = vport_to_shost(vport);
 138        struct fc_lport *n_port = shost_priv(shost);
 139
 140        mutex_lock(&n_port->lp_mutex);
 141        mutex_lock_nested(&vn_port->lp_mutex, LPORT_MUTEX_VN_PORT);
 142        __fc_vport_setlink(n_port, vn_port);
 143        mutex_unlock(&vn_port->lp_mutex);
 144        mutex_unlock(&n_port->lp_mutex);
 145}
 146EXPORT_SYMBOL(fc_vport_setlink);
 147
 148/**
 149 * fc_vports_linkchange() - change the link state of all vports
 150 * @n_port: Parent N_Port that has changed state
 151 *
 152 * Locking: called with the n_port lp_mutex held
 153 */
 154void fc_vports_linkchange(struct fc_lport *n_port)
 155{
 156        struct fc_lport *vn_port;
 157
 158        list_for_each_entry(vn_port, &n_port->vports, list) {
 159                mutex_lock_nested(&vn_port->lp_mutex, LPORT_MUTEX_VN_PORT);
 160                __fc_vport_setlink(n_port, vn_port);
 161                mutex_unlock(&vn_port->lp_mutex);
 162        }
 163}
 164
 165