diff options
Diffstat (limited to 'drivers/scsi/fcoe/fcoe_transport.c')
| -rw-r--r-- | drivers/scsi/fcoe/fcoe_transport.c | 770 |
1 files changed, 770 insertions, 0 deletions
diff --git a/drivers/scsi/fcoe/fcoe_transport.c b/drivers/scsi/fcoe/fcoe_transport.c new file mode 100644 index 00000000000..258684101bf --- /dev/null +++ b/drivers/scsi/fcoe/fcoe_transport.c @@ -0,0 +1,770 @@ +/* + * 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_attach - 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; + + mutex_lock(&ft_mutex); + if (!ft->attached) { + LIBFCOE_TRANSPORT_DBG("transport %s already detached\n", + ft->name); + rc = -ENODEV; + goto out_attach; + } + + 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) { + i += snprintf(&buffer[i], IFNAMSIZ, "%s ", ft->name); + if (i >= PAGE_SIZE) + break; + } + 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; + + if (!mutex_trylock(&ft_mutex)) + return restart_syscall(); + +#ifdef CONFIG_LIBFCOE_MODULE + /* + * Make sure the module has been initialized, and is not about to be + * removed. Module parameter sysfs files are writable before the + * module_init function is called and after module_exit. + */ + if (THIS_MODULE->state != MODULE_STATE_LIVE) + goto out_nodev; +#endif + + 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); + if (rc == -ERESTARTSYS) + return restart_syscall(); + else + 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; + + if (!mutex_trylock(&ft_mutex)) + return restart_syscall(); + +#ifdef CONFIG_LIBFCOE_MODULE + /* + * Make sure the module has been initialized, and is not about to be + * removed. Module parameter sysfs files are writable before the + * module_init function is called and after module_exit. + */ + if (THIS_MODULE->state != MODULE_STATE_LIVE) + goto out_nodev; +#endif + + 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); + + if (rc == -ERESTARTSYS) + return restart_syscall(); + else + 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; + + if (!mutex_trylock(&ft_mutex)) + return restart_syscall(); + +#ifdef CONFIG_LIBFCOE_MODULE + /* + * Make sure the module has been initialized, and is not about to be + * removed. Module parameter sysfs files are writable before the + * module_init function is called and after module_exit. + */ + if (THIS_MODULE->state != MODULE_STATE_LIVE) + goto out_nodev; +#endif + + 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; + + if (!mutex_trylock(&ft_mutex)) + return restart_syscall(); + +#ifdef CONFIG_LIBFCOE_MODULE + /* + * Make sure the module has been initialized, and is not about to be + * removed. Module parameter sysfs files are writable before the + * module_init function is called and after module_exit. + */ + if (THIS_MODULE->state != MODULE_STATE_LIVE) + goto out_nodev; +#endif + + 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); + if (rc == -ERESTARTSYS) + return restart_syscall(); + else + 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); |