kernel-fxtec-pro1x/drivers/scsi/fcoe/fcoe_sw.c
Vasu Dev bc0e17f691 [SCSI] libfc, fcoe: fixed locking issues with lport->lp_mutex around lport->link_status
The fcoe_xmit could call fc_pause in case the pending skb queue len is larger
than FCOE_MAX_QUEUE_DEPTH, the fc_pause was trying to grab lport->lp_muex to
change lport->link_status and that had these issues :-

1. The fcoe_xmit was getting called with bh disabled, thus causing
"BUG: scheduling while atomic" when grabbing lport->lp_muex with bh disabled.

2. fc_linkup and fc_linkdown function calls lport_enter function with
lport->lp_mutex held and these enter function in turn calls fcoe_xmit to send
lport related FC frame, e.g. fc_linkup => fc_lport_enter_flogi to send flogi
req. In this case grabbing the same lport->lp_mutex again in fc_puase from
fcoe_xmit would cause deadlock.

The lport->lp_mutex was used for setting FC_PAUSE in fcoe_xmit path but
FC_PAUSE bit was not used anywhere beside just setting and clear this
bit in lport->link_status, instead used a separate field qfull in fc_lport
to eliminate need for lport->lp_mutex to track pending queue full condition
and in turn avoid above described two locking issues.

Also added check for lp->qfull in fc_fcp_lport_queue_ready to trigger
SCSI_MLQUEUE_HOST_BUSY when lp->qfull is set to prevent more scsi-ml cmds
while lp->qfull is set.

This patch eliminated FC_LINK_UP and FC_PAUSE and instead used dedicated
fields in fc_lport for this, this simplified all related conditional
code.

Also removed fc_pause and fc_unpause functions and instead used newly added
lport->qfull directly in fcoe.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-03-06 15:37:49 -06:00

494 lines
12 KiB
C

/*
* Copyright(c) 2007 - 2008 Intel Corporation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
*
* Maintained at www.Open-FCoE.org
*/
#include <linux/module.h>
#include <linux/version.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/if_vlan.h>
#include <net/rtnetlink.h>
#include <scsi/fc/fc_els.h>
#include <scsi/fc/fc_encaps.h>
#include <scsi/fc/fc_fs.h>
#include <scsi/scsi_transport.h>
#include <scsi/scsi_transport_fc.h>
#include <scsi/libfc.h>
#include <scsi/libfcoe.h>
#include <scsi/fc_transport_fcoe.h>
#define FCOE_SW_VERSION "0.1"
#define FCOE_SW_NAME "fcoesw"
#define FCOE_SW_VENDOR "Open-FCoE.org"
#define FCOE_MAX_LUN 255
#define FCOE_MAX_FCP_TARGET 256
#define FCOE_MAX_OUTSTANDING_COMMANDS 1024
#define FCOE_MIN_XID 0x0001 /* the min xid supported by fcoe_sw */
#define FCOE_MAX_XID 0x07ef /* the max xid supported by fcoe_sw */
static struct scsi_transport_template *scsi_transport_fcoe_sw;
struct fc_function_template fcoe_sw_transport_function = {
.show_host_node_name = 1,
.show_host_port_name = 1,
.show_host_supported_classes = 1,
.show_host_supported_fc4s = 1,
.show_host_active_fc4s = 1,
.show_host_maxframe_size = 1,
.show_host_port_id = 1,
.show_host_supported_speeds = 1,
.get_host_speed = fc_get_host_speed,
.show_host_speed = 1,
.show_host_port_type = 1,
.get_host_port_state = fc_get_host_port_state,
.show_host_port_state = 1,
.show_host_symbolic_name = 1,
.dd_fcrport_size = sizeof(struct fc_rport_libfc_priv),
.show_rport_maxframe_size = 1,
.show_rport_supported_classes = 1,
.show_host_fabric_name = 1,
.show_starget_node_name = 1,
.show_starget_port_name = 1,
.show_starget_port_id = 1,
.set_rport_dev_loss_tmo = fc_set_rport_loss_tmo,
.show_rport_dev_loss_tmo = 1,
.get_fc_host_stats = fc_get_host_stats,
.issue_fc_host_lip = fcoe_reset,
.terminate_rport_io = fc_rport_terminate_io,
};
static struct scsi_host_template fcoe_sw_shost_template = {
.module = THIS_MODULE,
.name = "FCoE Driver",
.proc_name = FCOE_SW_NAME,
.queuecommand = fc_queuecommand,
.eh_abort_handler = fc_eh_abort,
.eh_device_reset_handler = fc_eh_device_reset,
.eh_host_reset_handler = fc_eh_host_reset,
.slave_alloc = fc_slave_alloc,
.change_queue_depth = fc_change_queue_depth,
.change_queue_type = fc_change_queue_type,
.this_id = -1,
.cmd_per_lun = 32,
.can_queue = FCOE_MAX_OUTSTANDING_COMMANDS,
.use_clustering = ENABLE_CLUSTERING,
.sg_tablesize = SG_ALL,
.max_sectors = 0xffff,
};
/*
* fcoe_sw_lport_config - sets up the fc_lport
* @lp: ptr to the fc_lport
* @shost: ptr to the parent scsi host
*
* Returns: 0 for success
*
*/
static int fcoe_sw_lport_config(struct fc_lport *lp)
{
int i = 0;
lp->link_up = 0;
lp->qfull = 0;
lp->max_retry_count = 3;
lp->e_d_tov = 2 * 1000; /* FC-FS default */
lp->r_a_tov = 2 * 2 * 1000;
lp->service_params = (FCP_SPPF_INIT_FCN | FCP_SPPF_RD_XRDY_DIS |
FCP_SPPF_RETRY | FCP_SPPF_CONF_COMPL);
/*
* allocate per cpu stats block
*/
for_each_online_cpu(i)
lp->dev_stats[i] = kzalloc(sizeof(struct fcoe_dev_stats),
GFP_KERNEL);
/* lport fc_lport related configuration */
fc_lport_config(lp);
return 0;
}
/*
* fcoe_sw_netdev_config - sets up fcoe_softc for lport and network
* related properties
* @lp : ptr to the fc_lport
* @netdev : ptr to the associated netdevice struct
*
* Must be called after fcoe_sw_lport_config() as it will use lport mutex
*
* Returns : 0 for success
*
*/
static int fcoe_sw_netdev_config(struct fc_lport *lp, struct net_device *netdev)
{
u32 mfs;
u64 wwnn, wwpn;
struct fcoe_softc *fc;
u8 flogi_maddr[ETH_ALEN];
/* Setup lport private data to point to fcoe softc */
fc = lport_priv(lp);
fc->lp = lp;
fc->real_dev = netdev;
fc->phys_dev = netdev;
/* Require support for get_pauseparam ethtool op. */
if (netdev->priv_flags & IFF_802_1Q_VLAN)
fc->phys_dev = vlan_dev_real_dev(netdev);
/* Do not support for bonding device */
if ((fc->real_dev->priv_flags & IFF_MASTER_ALB) ||
(fc->real_dev->priv_flags & IFF_SLAVE_INACTIVE) ||
(fc->real_dev->priv_flags & IFF_MASTER_8023AD)) {
return -EOPNOTSUPP;
}
/*
* Determine max frame size based on underlying device and optional
* user-configured limit. If the MFS is too low, fcoe_link_ok()
* will return 0, so do this first.
*/
mfs = fc->real_dev->mtu - (sizeof(struct fcoe_hdr) +
sizeof(struct fcoe_crc_eof));
if (fc_set_mfs(lp, mfs))
return -EINVAL;
if (!fcoe_link_ok(lp))
lp->link_up = 1;
/* offload features support */
if (fc->real_dev->features & NETIF_F_SG)
lp->sg_supp = 1;
skb_queue_head_init(&fc->fcoe_pending_queue);
/* setup Source Mac Address */
memcpy(fc->ctl_src_addr, fc->real_dev->dev_addr,
fc->real_dev->addr_len);
wwnn = fcoe_wwn_from_mac(fc->real_dev->dev_addr, 1, 0);
fc_set_wwnn(lp, wwnn);
/* XXX - 3rd arg needs to be vlan id */
wwpn = fcoe_wwn_from_mac(fc->real_dev->dev_addr, 2, 0);
fc_set_wwpn(lp, wwpn);
/*
* Add FCoE MAC address as second unicast MAC address
* or enter promiscuous mode if not capable of listening
* for multiple unicast MACs.
*/
rtnl_lock();
memcpy(flogi_maddr, (u8[6]) FC_FCOE_FLOGI_MAC, ETH_ALEN);
dev_unicast_add(fc->real_dev, flogi_maddr, ETH_ALEN);
rtnl_unlock();
/*
* setup the receive function from ethernet driver
* on the ethertype for the given device
*/
fc->fcoe_packet_type.func = fcoe_rcv;
fc->fcoe_packet_type.type = __constant_htons(ETH_P_FCOE);
fc->fcoe_packet_type.dev = fc->real_dev;
dev_add_pack(&fc->fcoe_packet_type);
return 0;
}
/*
* fcoe_sw_shost_config - sets up fc_lport->host
* @lp : ptr to the fc_lport
* @shost : ptr to the associated scsi host
* @dev : device associated to scsi host
*
* Must be called after fcoe_sw_lport_config) and fcoe_sw_netdev_config()
*
* Returns : 0 for success
*
*/
static int fcoe_sw_shost_config(struct fc_lport *lp, struct Scsi_Host *shost,
struct device *dev)
{
int rc = 0;
/* lport scsi host config */
lp->host = shost;
lp->host->max_lun = FCOE_MAX_LUN;
lp->host->max_id = FCOE_MAX_FCP_TARGET;
lp->host->max_channel = 0;
lp->host->transportt = scsi_transport_fcoe_sw;
/* add the new host to the SCSI-ml */
rc = scsi_add_host(lp->host, dev);
if (rc) {
FC_DBG("fcoe_sw_shost_config:error on scsi_add_host\n");
return rc;
}
sprintf(fc_host_symbolic_name(lp->host), "%s v%s over %s",
FCOE_SW_NAME, FCOE_SW_VERSION,
fcoe_netdev(lp)->name);
return 0;
}
/*
* fcoe_sw_em_config - allocates em for this lport
* @lp: the port that em is to allocated for
*
* Returns : 0 on success
*/
static inline int fcoe_sw_em_config(struct fc_lport *lp)
{
BUG_ON(lp->emp);
lp->emp = fc_exch_mgr_alloc(lp, FC_CLASS_3,
FCOE_MIN_XID, FCOE_MAX_XID);
if (!lp->emp)
return -ENOMEM;
return 0;
}
/*
* fcoe_sw_destroy - FCoE software HBA tear-down function
* @netdev: ptr to the associated net_device
*
* Returns: 0 if link is OK for use by FCoE.
*/
static int fcoe_sw_destroy(struct net_device *netdev)
{
int cpu;
struct fc_lport *lp = NULL;
struct fcoe_softc *fc;
u8 flogi_maddr[ETH_ALEN];
BUG_ON(!netdev);
printk(KERN_DEBUG "fcoe_sw_destroy:interface on %s\n",
netdev->name);
lp = fcoe_hostlist_lookup(netdev);
if (!lp)
return -ENODEV;
fc = fcoe_softc(lp);
/* Logout of the fabric */
fc_fabric_logoff(lp);
/* Remove the instance from fcoe's list */
fcoe_hostlist_remove(lp);
/* Don't listen for Ethernet packets anymore */
dev_remove_pack(&fc->fcoe_packet_type);
/* Cleanup the fc_lport */
fc_lport_destroy(lp);
fc_fcp_destroy(lp);
/* Detach from the scsi-ml */
fc_remove_host(lp->host);
scsi_remove_host(lp->host);
/* There are no more rports or I/O, free the EM */
if (lp->emp)
fc_exch_mgr_free(lp->emp);
/* Delete secondary MAC addresses */
rtnl_lock();
memcpy(flogi_maddr, (u8[6]) FC_FCOE_FLOGI_MAC, ETH_ALEN);
dev_unicast_delete(fc->real_dev, flogi_maddr, ETH_ALEN);
if (compare_ether_addr(fc->data_src_addr, (u8[6]) { 0 }))
dev_unicast_delete(fc->real_dev, fc->data_src_addr, ETH_ALEN);
rtnl_unlock();
/* Free the per-CPU revieve threads */
fcoe_percpu_clean(lp);
/* Free existing skbs */
fcoe_clean_pending_queue(lp);
/* Free memory used by statistical counters */
for_each_online_cpu(cpu)
kfree(lp->dev_stats[cpu]);
/* Release the net_device and Scsi_Host */
dev_put(fc->real_dev);
scsi_host_put(lp->host);
return 0;
}
static struct libfc_function_template fcoe_sw_libfc_fcn_templ = {
.frame_send = fcoe_xmit,
};
/*
* fcoe_sw_create - this function creates the fcoe interface
* @netdev: pointer the associated netdevice
*
* Creates fc_lport struct and scsi_host for lport, configures lport
* and starts fabric login.
*
* Returns : 0 on success
*/
static int fcoe_sw_create(struct net_device *netdev)
{
int rc;
struct fc_lport *lp = NULL;
struct fcoe_softc *fc;
struct Scsi_Host *shost;
BUG_ON(!netdev);
printk(KERN_DEBUG "fcoe_sw_create:interface on %s\n",
netdev->name);
lp = fcoe_hostlist_lookup(netdev);
if (lp)
return -EEXIST;
shost = fcoe_host_alloc(&fcoe_sw_shost_template,
sizeof(struct fcoe_softc));
if (!shost) {
FC_DBG("Could not allocate host structure\n");
return -ENOMEM;
}
lp = shost_priv(shost);
fc = lport_priv(lp);
/* configure fc_lport, e.g., em */
rc = fcoe_sw_lport_config(lp);
if (rc) {
FC_DBG("Could not configure lport\n");
goto out_host_put;
}
/* configure lport network properties */
rc = fcoe_sw_netdev_config(lp, netdev);
if (rc) {
FC_DBG("Could not configure netdev for lport\n");
goto out_host_put;
}
/* configure lport scsi host properties */
rc = fcoe_sw_shost_config(lp, shost, &netdev->dev);
if (rc) {
FC_DBG("Could not configure shost for lport\n");
goto out_host_put;
}
/* lport exch manager allocation */
rc = fcoe_sw_em_config(lp);
if (rc) {
FC_DBG("Could not configure em for lport\n");
goto out_host_put;
}
/* Initialize the library */
rc = fcoe_libfc_config(lp, &fcoe_sw_libfc_fcn_templ);
if (rc) {
FC_DBG("Could not configure libfc for lport!\n");
goto out_lp_destroy;
}
/* add to lports list */
fcoe_hostlist_add(lp);
lp->boot_time = jiffies;
fc_fabric_login(lp);
dev_hold(netdev);
return rc;
out_lp_destroy:
fc_exch_mgr_free(lp->emp); /* Free the EM */
out_host_put:
scsi_host_put(lp->host);
return rc;
}
/*
* fcoe_sw_match - the fcoe sw transport match function
*
* Returns : false always
*/
static bool fcoe_sw_match(struct net_device *netdev)
{
/* FIXME - for sw transport, always return false */
return false;
}
/* the sw hba fcoe transport */
struct fcoe_transport fcoe_sw_transport = {
.name = "fcoesw",
.create = fcoe_sw_create,
.destroy = fcoe_sw_destroy,
.match = fcoe_sw_match,
.vendor = 0x0,
.device = 0xffff,
};
/*
* fcoe_sw_init - registers fcoe_sw_transport
*
* Returns : 0 on success
*/
int __init fcoe_sw_init(void)
{
/* attach to scsi transport */
scsi_transport_fcoe_sw =
fc_attach_transport(&fcoe_sw_transport_function);
if (!scsi_transport_fcoe_sw) {
printk(KERN_ERR "fcoe_sw_init:fc_attach_transport() failed\n");
return -ENODEV;
}
/* register sw transport */
fcoe_transport_register(&fcoe_sw_transport);
return 0;
}
/*
* fcoe_sw_exit - unregisters fcoe_sw_transport
*
* Returns : 0 on success
*/
int __exit fcoe_sw_exit(void)
{
/* dettach the transport */
fc_release_transport(scsi_transport_fcoe_sw);
fcoe_transport_unregister(&fcoe_sw_transport);
return 0;
}