// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright(c) 2009 Intel Corporation. All rights reserved.
 *
 * Maintained at www.Open-FCoE.org
 */

/*
 * NPIV VN_Port helper functions for libfc
 */

#include <scsi/libfc.h>
#include <linux/export.h>

/**
 * libfc_vport_create() - Create a new NPIV vport instance
 * @vport: fc_vport structure from scsi_transport_fc
 * @privsize: driver private data size to allocate along with the Scsi_Host
 */

struct fc_lport *libfc_vport_create(struct fc_vport *vport, int privsize)
{
        struct Scsi_Host *shost = vport_to_shost(vport);
        struct fc_lport *n_port = shost_priv(shost);
        struct fc_lport *vn_port;

        vn_port = libfc_host_alloc(shost->hostt, privsize);
        if (!vn_port)
                return vn_port;

        vn_port->vport = vport;
        vport->dd_data = vn_port;

        mutex_lock(&n_port->lp_mutex);
        list_add_tail(&vn_port->list, &n_port->vports);
        mutex_unlock(&n_port->lp_mutex);

        return vn_port;
}
EXPORT_SYMBOL(libfc_vport_create);

/**
 * fc_vport_id_lookup() - find NPIV lport that matches a given fabric ID
 * @n_port: Top level N_Port which may have multiple NPIV VN_Ports
 * @port_id: Fabric ID to find a match for
 *
 * Returns: matching lport pointer or NULL if there is no match
 */
struct fc_lport *fc_vport_id_lookup(struct fc_lport *n_port, u32 port_id)
{
        struct fc_lport *lport = NULL;
        struct fc_lport *vn_port;

        if (n_port->port_id == port_id)
                return n_port;

        if (port_id == FC_FID_FLOGI)
                return n_port;          /* for point-to-point */

        mutex_lock(&n_port->lp_mutex);
        list_for_each_entry(vn_port, &n_port->vports, list) {
                if (vn_port->port_id == port_id) {
                        lport = vn_port;
                        break;
                }
        }
        mutex_unlock(&n_port->lp_mutex);

        return lport;
}
EXPORT_SYMBOL(fc_vport_id_lookup);

/*
 * When setting the link state of vports during an lport state change, it's
 * necessary to hold the lp_mutex of both the N_Port and the VN_Port.
 * This tells the lockdep engine to treat the nested locking of the VN_Port
 * as a different lock class.
 */
enum libfc_lport_mutex_class {
        LPORT_MUTEX_NORMAL = 0,
        LPORT_MUTEX_VN_PORT = 1,
};

/**
 * __fc_vport_setlink() - update link and status on a VN_Port
 * @n_port: parent N_Port
 * @vn_port: VN_Port to update
 *
 * Locking: must be called with both the N_Port and VN_Port lp_mutex held
 */
static void __fc_vport_setlink(struct fc_lport *n_port,
                               struct fc_lport *vn_port)
{
        struct fc_vport *vport = vn_port->vport;

        if (vn_port->state == LPORT_ST_DISABLED)
                return;

        if (n_port->state == LPORT_ST_READY) {
                if (n_port->npiv_enabled) {
                        fc_vport_set_state(vport, FC_VPORT_INITIALIZING);
                        __fc_linkup(vn_port);
                } else {
                        fc_vport_set_state(vport, FC_VPORT_NO_FABRIC_SUPP);
                        __fc_linkdown(vn_port);
                }
        } else {
                fc_vport_set_state(vport, FC_VPORT_LINKDOWN);
                __fc_linkdown(vn_port);
        }
}

/**
 * fc_vport_setlink() - update link and status on a VN_Port
 * @vn_port: virtual port to update
 */
void fc_vport_setlink(struct fc_lport *vn_port)
{
        struct fc_vport *vport = vn_port->vport;
        struct Scsi_Host *shost = vport_to_shost(vport);
        struct fc_lport *n_port = shost_priv(shost);

        mutex_lock(&n_port->lp_mutex);
        mutex_lock_nested(&vn_port->lp_mutex, LPORT_MUTEX_VN_PORT);
        __fc_vport_setlink(n_port, vn_port);
        mutex_unlock(&vn_port->lp_mutex);
        mutex_unlock(&n_port->lp_mutex);
}
EXPORT_SYMBOL(fc_vport_setlink);

/**
 * fc_vports_linkchange() - change the link state of all vports
 * @n_port: Parent N_Port that has changed state
 *
 * Locking: called with the n_port lp_mutex held
 */
void fc_vports_linkchange(struct fc_lport *n_port)
{
        struct fc_lport *vn_port;

        list_for_each_entry(vn_port, &n_port->vports, list) {
                mutex_lock_nested(&vn_port->lp_mutex, LPORT_MUTEX_VN_PORT);
                __fc_vport_setlink(n_port, vn_port);
                mutex_unlock(&vn_port->lp_mutex);
        }
}