- 根目录:
- drivers
- scsi
- fcoe
- fcoe_transport.c
/*
* Copyright(c) 2008 - 2011 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/types.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/netdevice.h>
#include <linux/errno.h>
#include <linux/crc32.h>
#include <scsi/libfcoe.h>
#include "libfcoe.h"
MODULE_AUTHOR("Open-FCoE.org");
MODULE_DESCRIPTION("FIP discovery protocol and FCoE transport for FCoE HBAs");
MODULE_LICENSE("GPL v2");
static int fcoe_transport_create(const char *, struct kernel_param *);
static int fcoe_transport_destroy(const char *, struct kernel_param *);
static int fcoe_transport_show(char *buffer, const struct kernel_param *kp);
static struct fcoe_transport *fcoe_transport_lookup(struct net_device *device);
static struct fcoe_transport *fcoe_netdev_map_lookup(struct net_device *device);
static int fcoe_transport_enable(const char *, struct kernel_param *);
static int fcoe_transport_disable(const char *, struct kernel_param *);
static int libfcoe_device_notification(struct notifier_block *notifier,
ulong event, void *ptr);
static LIST_HEAD(fcoe_transports);
static DEFINE_MUTEX(ft_mutex);
static LIST_HEAD(fcoe_netdevs);
static DEFINE_MUTEX(fn_mutex);
unsigned int libfcoe_debug_logging;
module_param_named(debug_logging, libfcoe_debug_logging, int, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(debug_logging, "a bit mask of logging levels");
module_param_call(show, NULL, fcoe_transport_show, NULL, S_IRUSR);
__MODULE_PARM_TYPE(show, "string");
MODULE_PARM_DESC(show, " Show attached FCoE transports");
module_param_call(create, fcoe_transport_create, NULL,
(void *)FIP_MODE_FABRIC, S_IWUSR);
__MODULE_PARM_TYPE(create, "string");
MODULE_PARM_DESC(create, " Creates fcoe instance on a ethernet interface");
module_param_call(create_vn2vn, fcoe_transport_create, NULL,
(void *)FIP_MODE_VN2VN, S_IWUSR);
__MODULE_PARM_TYPE(create_vn2vn, "string");
MODULE_PARM_DESC(create_vn2vn, " Creates a VN_node to VN_node FCoE instance "
"on an Ethernet interface");
module_param_call(destroy, fcoe_transport_destroy, NULL, NULL, S_IWUSR);
__MODULE_PARM_TYPE(destroy, "string");
MODULE_PARM_DESC(destroy, " Destroys fcoe instance on a ethernet interface");
module_param_call(enable, fcoe_transport_enable, NULL, NULL, S_IWUSR);
__MODULE_PARM_TYPE(enable, "string");
MODULE_PARM_DESC(enable, " Enables fcoe on a ethernet interface.");
module_param_call(disable, fcoe_transport_disable, NULL, NULL, S_IWUSR);
__MODULE_PARM_TYPE(disable, "string");
MODULE_PARM_DESC(disable, " Disables fcoe on a ethernet interface.");
/* notification function for packets from net device */
static struct notifier_block libfcoe_notifier = {
.notifier_call = libfcoe_device_notification,
};
/**
* fcoe_fc_crc() - Calculates the CRC for a given frame
* @fp: The frame to be checksumed
*
* This uses crc32() routine to calculate the CRC for a frame
*
* Return: The 32 bit CRC value
*/
u32 fcoe_fc_crc(struct fc_frame *fp)
{
struct sk_buff *skb = fp_skb(fp);
struct skb_frag_struct *frag;
unsigned char *data;
unsigned long off, len, clen;
u32 crc;
unsigned i;
crc = crc32(~0, skb->data, skb_headlen(skb));
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
frag = &skb_shinfo(skb)->frags[i];
off = frag->page_offset;
len = frag->size;
while (len > 0) {
clen = min(len, PAGE_SIZE - (off & ~PAGE_MASK));
data = kmap_atomic(frag->page + (off >> PAGE_SHIFT),
KM_SKB_DATA_SOFTIRQ);
crc = crc32(crc, data + (off & ~PAGE_MASK), clen);
kunmap_atomic(data, KM_SKB_DATA_SOFTIRQ);
off += clen;
len -= clen;
}
}
return crc;
}
EXPORT_SYMBOL_GPL(fcoe_fc_crc);
/**
* fcoe_start_io() - Start FCoE I/O
* @skb: The packet to be transmitted
*
* This routine is called from the net device to start transmitting
* FCoE packets.
*
* Returns: 0 for success
*/
int fcoe_start_io(struct sk_buff *skb)
{
struct sk_buff *nskb;
int rc;
nskb = skb_clone(skb, GFP_ATOMIC);
if (!nskb)
return -ENOMEM;
rc = dev_queue_xmit(nskb);
if (rc != 0)
return rc;
kfree_skb(skb);
return 0;
}
EXPORT_SYMBOL_GPL(fcoe_start_io);
/**
* fcoe_clean_pending_queue() - Dequeue a skb and free it
* @lport: The local port to dequeue a skb on
*/
void fcoe_clean_pending_queue(struct fc_lport *lport)
{
struct fcoe_port *port = lport_priv(lport);
struct sk_buff *skb;
spin_lock_bh(&port->fcoe_pending_queue.lock);
while ((skb = __skb_dequeue(&port->fcoe_pending_queue)) != NULL) {
spin_unlock_bh(&port->fcoe_pending_queue.lock);
kfree_skb(skb);
spin_lock_bh(&port->fcoe_pending_queue.lock);
}
spin_unlock_bh(&port->fcoe_pending_queue.lock);
}
EXPORT_SYMBOL_GPL(fcoe_clean_pending_queue);
/**
* fcoe_check_wait_queue() - Attempt to clear the transmit backlog
* @lport: The local port whose backlog is to be cleared
*
* This empties the wait_queue, dequeues the head of the wait_queue queue
* and calls fcoe_start_io() for each packet. If all skb have been
* transmitted it returns the qlen. If an error occurs it restores
* wait_queue (to try again later) and returns -1.
*
* The wait_queue is used when the skb transmit fails. The failed skb
* will go in the wait_queue which will be emptied by the timer function or
* by the next skb transmit.
*/
void fcoe_check_wait_queue(struct fc_lport *lport, struct sk_buff *skb)
{
struct fcoe_port *port = lport_priv(lport);
int rc;
spin_lock_bh(&port->fcoe_pending_queue.lock);
if (skb)
__skb_queue_tail(&port->fcoe_pending_queue, skb);
if (port->fcoe_pending_queue_active)
goto out;
port->fcoe_pending_queue_active = 1;
while (port->fcoe_pending_queue.qlen) {
/* keep qlen > 0 until fcoe_start_io succeeds */
port->fcoe_pending_queue.qlen++;
skb = __skb_dequeue(&port->fcoe_pending_queue);
spin_unlock_bh(&port->fcoe_pending_queue.lock);
rc = fcoe_start_io(skb);
spin_lock_bh(&port->fcoe_pending_queue.lock);
if (rc) {
__skb_queue_head(&port->fcoe_pending_queue, skb);
/* undo temporary increment above */
port->fcoe_pending_queue.qlen--;
break;
}
/* undo temporary increment above */
port->fcoe_pending_queue.qlen--;
}
if (port->fcoe_pending_queue.qlen < port->min_queue_depth)
lport->qfull = 0;
if (port->fcoe_pending_queue.qlen && !timer_pending(&port->timer))
mod_timer(&port->timer, jiffies + 2);
port->fcoe_pending_queue_active = 0;
out:
if (port->fcoe_pending_queue.qlen > port->max_queue_depth)
lport->qfull = 1;
spin_unlock_bh(&port->fcoe_pending_queue.lock);
}
EXPORT_SYMBOL_GPL(fcoe_check_wait_queue);
/**
* fcoe_queue_timer() - The fcoe queue timer
* @lport: The local port
*
* Calls fcoe_check_wait_queue on timeout
*/
void fcoe_queue_timer(ulong lport)
{
fcoe_check_wait_queue((struct fc_lport *)lport, NULL);
}
EXPORT_SYMBOL_GPL(fcoe_queue_timer);
/**
* fcoe_get_paged_crc_eof() - Allocate a page to be used for the trailer CRC
* @skb: The packet to be transmitted
* @tlen: The total length of the trailer
* @fps: The fcoe context
*
* This routine allocates a page for frame trailers. The page is re-used if
* there is enough room left on it for the current trailer. If there isn't
* enough buffer left a new page is allocated for the trailer. Reference to
* the page from this function as well as the skbs using the page fragments
* ensure that the page is freed at the appropriate time.
*
* Returns: 0 for success
*/
int fcoe_get_paged_crc_eof(struct sk_buff *skb, int tlen,
struct fcoe_percpu_s *fps)
{
struct page *page;
page = fps->crc_eof_page;
if (!page) {
page = alloc_page(GFP_ATOMIC);
if (!page)
return -ENOMEM;
fps->crc_eof_page = page;
fps->crc_eof_offset = 0;
}
get_page(page);
skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags, page,
fps->crc_eof_offset, tlen);
skb->len += tlen;
skb->data_len += tlen;
skb->truesize += tlen;
fps->crc_eof_offset += sizeof(struct fcoe_crc_eof);
if (fps->crc_eof_offset >= PAGE_SIZE) {
fps->crc_eof_page = NULL;
fps->crc_eof_offset = 0;
put_page(page);
}
return 0;
}
EXPORT_SYMBOL_GPL(fcoe_get_paged_crc_eof);
/**
* fcoe_transport_lookup - find an fcoe transport that matches a netdev
* @netdev: The netdev to look for from all attached transports
*
* Returns : ptr to the fcoe transport that supports this netdev or NULL
* if not found.
*
* The ft_mutex should be held when this is called
*/
static struct fcoe_transport *fcoe_transport_lookup(struct net_device *netdev)
{
struct fcoe_transport *ft = NULL;
list_for_each_entry(ft, &fcoe_transports, list)
if (ft->match && ft->match(netdev))
return ft;
return NULL;
}
/**
* fcoe_transport_attach - Attaches an FCoE transport
* @ft: The fcoe transport to be attached
*
* Returns : 0 for success
*/
int fcoe_transport_attach(struct fcoe_transport *ft)
{
int rc = 0;
mutex_lock(&ft_mutex);
if (ft->attached) {
LIBFCOE_TRANSPORT_DBG("transport %s already attached\n",
ft->name);
rc = -EEXIST;
goto out_attach;
}
/* Add default transport to the tail */
if (strcmp(ft->name, FCOE_TRANSPORT_DEFAULT))
list_add(&ft->list, &fcoe_transports);
else
list_add_tail(&ft->list, &fcoe_transports);
ft->attached = true;
LIBFCOE_TRANSPORT_DBG("attaching transport %s\n", ft->name);
out_attach:
mutex_unlock(&ft_mutex);
return rc;
}
EXPORT_SYMBOL(fcoe_transport_attach);
/**
* fcoe_transport_detach - Detaches an FCoE transport
* @ft: The fcoe transport to be attached
*
* Returns : 0 for success
*/
int fcoe_transport_detach(struct fcoe_transport *ft)
{
int rc = 0;
struct fcoe_netdev_mapping *nm = NULL, *tmp;
mutex_lock(&ft_mutex);
if (!ft->attached) {
LIBFCOE_TRANSPORT_DBG("transport %s already detached\n",
ft->name);
rc = -ENODEV;
goto out_attach;
}
/* remove netdev mapping for this transport as it is going away */
mutex_lock(&fn_mutex);
list_for_each_entry_safe(nm, tmp, &fcoe_netdevs, list) {
if (nm->ft == ft) {
LIBFCOE_TRANSPORT_DBG("transport %s going away, "
"remove its netdev mapping for %s\n",
ft->name, nm->netdev->name);
list_del(&nm->list);
kfree(nm);
}
}
mutex_unlock(&fn_mutex);
list_del(&ft->list);
ft->attached = false;
LIBFCOE_TRANSPORT_DBG("detaching transport %s\n", ft->name);
out_attach:
mutex_unlock(&ft_mutex);
return rc;
}
EXPORT_SYMBOL(fcoe_transport_detach);
static int fcoe_transport_show(char *buffer, const struct kernel_param *kp)
{
int i, j;
struct fcoe_transport *ft = NULL;
i = j = sprintf(buffer, "Attached FCoE transports:");
mutex_lock(&ft_mutex);
list_for_each_entry(ft, &fcoe_transports, list) {
if (i >= PAGE_SIZE - IFNAMSIZ)
break;
i += snprintf(&buffer[i], IFNAMSIZ, "%s ", ft->name);
}
mutex_unlock(&ft_mutex);
if (i == j)
i += snprintf(&buffer[i], IFNAMSIZ, "none");
return i;
}
static int __init fcoe_transport_init(void)
{
register_netdevice_notifier(&libfcoe_notifier);
return 0;
}
static int __exit fcoe_transport_exit(void)
{
struct fcoe_transport *ft;
unregister_netdevice_notifier(&libfcoe_notifier);
mutex_lock(&ft_mutex);
list_for_each_entry(ft, &fcoe_transports, list)
printk(KERN_ERR "FCoE transport %s is still attached!\n",
ft->name);
mutex_unlock(&ft_mutex);
return 0;
}
static int fcoe_add_netdev_mapping(struct net_device *netdev,
struct fcoe_transport *ft)
{
struct fcoe_netdev_mapping *nm;
nm = kmalloc(sizeof(*nm), GFP_KERNEL);
if (!nm) {
printk(KERN_ERR "Unable to allocate netdev_mapping");
return -ENOMEM;
}
nm->netdev = netdev;
nm->ft = ft;
mutex_lock(&fn_mutex);
list_add(&nm->list, &fcoe_netdevs);
mutex_unlock(&fn_mutex);
return 0;
}
static void fcoe_del_netdev_mapping(struct net_device *netdev)
{
struct fcoe_netdev_mapping *nm = NULL, *tmp;
mutex_lock(&fn_mutex);
list_for_each_entry_safe(nm, tmp, &fcoe_netdevs, list) {
if (nm->netdev == netdev) {
list_del(&nm->list);
kfree(nm);
mutex_unlock(&fn_mutex);
return;
}
}
mutex_unlock(&fn_mutex);
}
/**
* fcoe_netdev_map_lookup - find the fcoe transport that matches the netdev on which
* it was created
*
* Returns : ptr to the fcoe transport that supports this netdev or NULL
* if not found.
*
* The ft_mutex should be held when this is called
*/
static struct fcoe_transport *fcoe_netdev_map_lookup(struct net_device *netdev)
{
struct fcoe_transport *ft = NULL;
struct fcoe_netdev_mapping *nm;
mutex_lock(&fn_mutex);
list_for_each_entry(nm, &fcoe_netdevs, list) {
if (netdev == nm->netdev) {
ft = nm->ft;
mutex_unlock(&fn_mutex);
return ft;
}
}
mutex_unlock(&fn_mutex);
return NULL;
}
/**
* fcoe_if_to_netdev() - Parse a name buffer to get a net device
* @buffer: The name of the net device
*
* Returns: NULL or a ptr to net_device
*/
static struct net_device *fcoe_if_to_netdev(const char *buffer)
{
char *cp;
char ifname[IFNAMSIZ + 2];
if (buffer) {
strlcpy(ifname, buffer, IFNAMSIZ);
cp = ifname + strlen(ifname);
while (--cp >= ifname && *cp == '\n')
*cp = '\0';
return dev_get_by_name(&init_net, ifname);
}
return NULL;
}
/**
* libfcoe_device_notification() - Handler for net device events
* @notifier: The context of the notification
* @event: The type of event
* @ptr: The net device that the event was on
*
* This function is called by the Ethernet driver in case of link change event.
*
* Returns: 0 for success
*/
static int libfcoe_device_notification(struct notifier_block *notifier,
ulong event, void *ptr)
{
struct net_device *netdev = ptr;
switch (event) {
case NETDEV_UNREGISTER:
printk(KERN_ERR "libfcoe_device_notification: NETDEV_UNREGISTER %s\n",
netdev->name);
fcoe_del_netdev_mapping(netdev);
break;
}
return NOTIFY_OK;
}
/**
* fcoe_transport_create() - Create a fcoe interface
* @buffer: The name of the Ethernet interface to create on
* @kp: The associated kernel param
*
* Called from sysfs. This holds the ft_mutex while calling the
* registered fcoe transport's create function.
*
* Returns: 0 for success
*/
static int fcoe_transport_create(const char *buffer, struct kernel_param *kp)
{
int rc = -ENODEV;
struct net_device *netdev = NULL;
struct fcoe_transport *ft = NULL;
enum fip_state fip_mode = (enum fip_state)(long)kp->arg;
mutex_lock(&ft_mutex);
netdev = fcoe_if_to_netdev(buffer);
if (!netdev) {
LIBFCOE_TRANSPORT_DBG("Invalid device %s.\n", buffer);
goto out_nodev;
}
ft = fcoe_netdev_map_lookup(netdev);
if (ft) {
LIBFCOE_TRANSPORT_DBG("transport %s already has existing "
"FCoE instance on %s.\n",
ft->name, netdev->name);
rc = -EEXIST;
goto out_putdev;
}
ft = fcoe_transport_lookup(netdev);
if (!ft) {
LIBFCOE_TRANSPORT_DBG("no FCoE transport found for %s.\n",
netdev->name);
goto out_putdev;
}
rc = fcoe_add_netdev_mapping(netdev, ft);
if (rc) {
LIBFCOE_TRANSPORT_DBG("failed to add new netdev mapping "
"for FCoE transport %s for %s.\n",
ft->name, netdev->name);
goto out_putdev;
}
/* pass to transport create */
rc = ft->create ? ft->create(netdev, fip_mode) : -ENODEV;
if (rc)
fcoe_del_netdev_mapping(netdev);
LIBFCOE_TRANSPORT_DBG("transport %s %s to create fcoe on %s.\n",
ft->name, (rc) ? "failed" : "succeeded",
netdev->name);
out_putdev:
dev_put(netdev);
out_nodev:
mutex_unlock(&ft_mutex);
return rc;
}
/**
* fcoe_transport_destroy() - Destroy a FCoE interface
* @buffer: The name of the Ethernet interface to be destroyed
* @kp: The associated kernel parameter
*
* Called from sysfs. This holds the ft_mutex while calling the
* registered fcoe transport's destroy function.
*
* Returns: 0 for success
*/
static int fcoe_transport_destroy(const char *buffer, struct kernel_param *kp)
{
int rc = -ENODEV;
struct net_device *netdev = NULL;
struct fcoe_transport *ft = NULL;
mutex_lock(&ft_mutex);
netdev = fcoe_if_to_netdev(buffer);
if (!netdev) {
LIBFCOE_TRANSPORT_DBG("invalid device %s.\n", buffer);
goto out_nodev;
}
ft = fcoe_netdev_map_lookup(netdev);
if (!ft) {
LIBFCOE_TRANSPORT_DBG("no FCoE transport found for %s.\n",
netdev->name);
goto out_putdev;
}
/* pass to transport destroy */
rc = ft->destroy ? ft->destroy(netdev) : -ENODEV;
fcoe_del_netdev_mapping(netdev);
LIBFCOE_TRANSPORT_DBG("transport %s %s to destroy fcoe on %s.\n",
ft->name, (rc) ? "failed" : "succeeded",
netdev->name);
out_putdev:
dev_put(netdev);
out_nodev:
mutex_unlock(&ft_mutex);
return rc;
}
/**
* fcoe_transport_disable() - Disables a FCoE interface
* @buffer: The name of the Ethernet interface to be disabled
* @kp: The associated kernel parameter
*
* Called from sysfs.
*
* Returns: 0 for success
*/
static int fcoe_transport_disable(const char *buffer, struct kernel_param *kp)
{
int rc = -ENODEV;
struct net_device *netdev = NULL;
struct fcoe_transport *ft = NULL;
mutex_lock(&ft_mutex);
netdev = fcoe_if_to_netdev(buffer);
if (!netdev)
goto out_nodev;
ft = fcoe_netdev_map_lookup(netdev);
if (!ft)
goto out_putdev;
rc = ft->disable ? ft->disable(netdev) : -ENODEV;
out_putdev:
dev_put(netdev);
out_nodev:
mutex_unlock(&ft_mutex);
if (rc == -ERESTARTSYS)
return restart_syscall();
else
return rc;
}
/**
* fcoe_transport_enable() - Enables a FCoE interface
* @buffer: The name of the Ethernet interface to be enabled
* @kp: The associated kernel parameter
*
* Called from sysfs.
*
* Returns: 0 for success
*/
static int fcoe_transport_enable(const char *buffer, struct kernel_param *kp)
{
int rc = -ENODEV;
struct net_device *netdev = NULL;
struct fcoe_transport *ft = NULL;
mutex_lock(&ft_mutex);
netdev = fcoe_if_to_netdev(buffer);
if (!netdev)
goto out_nodev;
ft = fcoe_netdev_map_lookup(netdev);
if (!ft)
goto out_putdev;
rc = ft->enable ? ft->enable(netdev) : -ENODEV;
out_putdev:
dev_put(netdev);
out_nodev:
mutex_unlock(&ft_mutex);
return rc;
}
/**
* libfcoe_init() - Initialization routine for libfcoe.ko
*/
static int __init libfcoe_init(void)
{
fcoe_transport_init();
return 0;
}
module_init(libfcoe_init);
/**
* libfcoe_exit() - Tear down libfcoe.ko
*/
static void __exit libfcoe_exit(void)
{
fcoe_transport_exit();
}
module_exit(libfcoe_exit);