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#include <linux/export.h>
  26
  27/**
  28 * fc_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
  33struct 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}
  52EXPORT_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 */
  61struct 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}
  83EXPORT_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 */
  91enum 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 */
 103static 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 */
 129void 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}
 141EXPORT_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 */
 149void 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