libfcoe, fcoe, bnx2fc: Add new fcoe control interface

This patch does a few things.

1) Makes /sys/bus/fcoe/ctlr_{create,destroy} interfaces.
   These interfaces take an <ifname> and will either
   create an FCoE Controller or destroy an FCoE
   Controller depending on which file is written to.

   The new FCoE Controller will start in a DISABLED
   state and will not do discovery or login until it
   is ENABLED. This pause will allow us to configure
   the FCoE Controller before enabling it.

2) Makes the 'mode' attribute of a fcoe_ctlr_device
   writale. This allows the user to configure the mode
   in which the FCoE Controller will start in when it
   is ENABLED.

   Possible modes are 'Fabric', or 'VN2VN'.

   The default mode for a fcoe_ctlr{,_device} is 'Fabric'.
   Drivers must implement the set_fcoe_ctlr_mode routine
   to support this feature.

   libfcoe offers an exported routine to set a FCoE
   Controller's mode. The mode can only be changed
   when the FCoE Controller is DISABLED.

   This patch also removes the get_fcoe_ctlr_mode pointer
   in the fcoe_sysfs function template, the code in
   fcoe_ctlr.c to get the mode and the assignment of
   the fcoe_sysfs function pointer to the fcoe_ctlr.c
   implementation (in fcoe and bnx2fc). fcoe_sysfs can
   return that value for the mode without consulting the
   LLD.

3) Make a 'enabled' attribute of a fcoe_ctlr_device. On a
   read, fcoe_sysfs will return the attribute's value. On
   a write, fcoe_sysfs will call the LLD (if there is a
   callback) to notifiy that the enalbed state has changed.

This patch maintains the old FCoE control interfaces as
module parameters, but it adds comments pointing out that
the old interfaces are deprecated.

Signed-off-by: Robert Love <robert.w.love@intel.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>

Documentation/ABI/testing/sysfs-bus-fcoe

@@ -1,14 +1,53 @@
+What:		/sys/bus/fcoe/
+Date:		August 2012
+KernelVersion:	TBD
+Contact:	Robert Love <robert.w.love@intel.com>, devel@open-fcoe.org
+Description:	The FCoE bus. Attributes in this directory are control interfaces.
+Attributes:
+
+	ctlr_create: 'FCoE Controller' instance creation interface. Writing an
+		     <ifname> to this file will allocate and populate sysfs with a
+		     fcoe_ctlr_device (ctlr_X). The user can then configure any
+		     per-port settings and finally write to the fcoe_ctlr_device's
+		     'start' attribute to begin the kernel's discovery and login
+		     process.
+
+	ctlr_destroy: 'FCoE Controller' instance removal interface. Writing a
+		       fcoe_ctlr_device's sysfs name to this file will log the
+		       fcoe_ctlr_device out of the fabric or otherwise connected
+		       FCoE devices. It will also free all kernel memory allocated
+		       for this fcoe_ctlr_device and any structures associated
+		       with it, this includes the scsi_host.
+
 What:		/sys/bus/fcoe/devices/ctlr_X
 Date:		March 2012
 KernelVersion:	TBD
 Contact:	Robert Love <robert.w.love@intel.com>, devel@open-fcoe.org
-Description:	'FCoE Controller' instances on the fcoe bus
+Description:	'FCoE Controller' instances on the fcoe bus.
+		The FCoE Controller now has a three stage creation process.
+		1) Write interface name to ctlr_create 2) Configure the FCoE
+		Controller (ctlr_X) 3) Enable the FCoE Controller to begin
+		discovery and login. The FCoE Controller is destroyed by
+		writing it's name, i.e. ctlr_X to the ctlr_delete file.
+
 Attributes:
 
 	fcf_dev_loss_tmo: Device loss timeout peroid (see below). Changing
 			  this value will change the dev_loss_tmo for all
 			  FCFs discovered by this controller.
 
+	mode:		  Display or change the FCoE Controller's mode. Possible
+			  modes are 'Fabric' and 'VN2VN'. If a FCoE Controller
+			  is started in 'Fabric' mode then FIP FCF discovery is
+			  initiated and ultimately a fabric login is attempted.
+			  If a FCoE Controller is started in 'VN2VN' mode then
+			  FIP VN2VN discovery and login is performed. A FCoE
+			  Controller only supports one mode at a time.
+
+	enabled:	  Whether an FCoE controller is enabled or disabled.
+			  0 if disabled, 1 if enabled. Writing either 0 or 1
+			  to this file will enable or disable the FCoE controller.
+
 	lesb/link_fail:   Link Error Status Block (LESB) link failure count.
 
 	lesb/vlink_fail:  Link Error Status Block (LESB) virtual link

drivers/scsi/bnx2fc/bnx2fc_fcoe.c

@@ -2555,7 +2555,6 @@ module_init(bnx2fc_mod_init);
 module_exit(bnx2fc_mod_exit);
 
 static struct fcoe_sysfs_function_template bnx2fc_fcoe_sysfs_templ = {
-	.get_fcoe_ctlr_mode = fcoe_ctlr_get_fip_mode,
 	.get_fcoe_ctlr_link_fail = bnx2fc_ctlr_get_lesb,
 	.get_fcoe_ctlr_vlink_fail = bnx2fc_ctlr_get_lesb,
 	.get_fcoe_ctlr_miss_fka = bnx2fc_ctlr_get_lesb,

drivers/scsi/fcoe/fcoe.c

@@ -155,7 +155,6 @@ static void fcoe_ctlr_get_lesb(struct fcoe_ctlr_device *);
 static void fcoe_fcf_get_vlan_id(struct fcoe_fcf_device *);
 
 static struct fcoe_sysfs_function_template fcoe_sysfs_templ = {
-	.get_fcoe_ctlr_mode = fcoe_ctlr_get_fip_mode,
 	.get_fcoe_ctlr_link_fail = fcoe_ctlr_get_lesb,
 	.get_fcoe_ctlr_vlink_fail = fcoe_ctlr_get_lesb,
 	.get_fcoe_ctlr_miss_fka = fcoe_ctlr_get_lesb,

drivers/scsi/fcoe/fcoe_sysfs.c

@@ -21,8 +21,10 @@
 #include <linux/types.h>
 #include <linux/kernel.h>
 #include <linux/etherdevice.h>
+#include <linux/ctype.h>
 
 #include <scsi/fcoe_sysfs.h>
+#include <scsi/libfcoe.h>
 
 /*
  * OK to include local libfcoe.h for debug_logging, but cannot include
@@ -78,6 +80,8 @@ MODULE_PARM_DESC(fcf_dev_loss_tmo,
 	((x)->lesb.lesb_err_block)
 #define fcoe_ctlr_fcs_error(x)			\
 	((x)->lesb.lesb_fcs_error)
+#define fcoe_ctlr_enabled(x)			\
+	((x)->enabled)
 #define fcoe_fcf_state(x)			\
 	((x)->state)
 #define fcoe_fcf_fabric_name(x)			\
@@ -228,7 +232,18 @@ static char *fip_conn_type_names[] = {
 	[ FIP_CONN_TYPE_VN2VN ]   = "VN2VN",
 };
 fcoe_enum_name_search(ctlr_mode, fip_conn_type, fip_conn_type_names)
-#define FCOE_CTLR_MODE_MAX_NAMELEN 50
+
+static enum fip_conn_type fcoe_parse_mode(const char *buf)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(fip_conn_type_names); i++) {
+		if (strcasecmp(buf, fip_conn_type_names[i]) == 0)
+			return i;
+	}
+
+	return FIP_CONN_TYPE_UNKNOWN;
+}
 
 static char *fcf_state_names[] = {
 	[ FCOE_FCF_STATE_UNKNOWN ]      = "Unknown",
@@ -259,17 +274,116 @@ static ssize_t show_ctlr_mode(struct device *dev,
 	struct fcoe_ctlr_device *ctlr = dev_to_ctlr(dev);
 	const char *name;
 
-	if (ctlr->f->get_fcoe_ctlr_mode)
-		ctlr->f->get_fcoe_ctlr_mode(ctlr);
-
 	name = get_fcoe_ctlr_mode_name(ctlr->mode);
 	if (!name)
 		return -EINVAL;
-	return snprintf(buf, FCOE_CTLR_MODE_MAX_NAMELEN,
+	return snprintf(buf, FCOE_MAX_MODENAME_LEN,
 			"%s\n", name);
 }
-static FCOE_DEVICE_ATTR(ctlr, mode, S_IRUGO,
-			show_ctlr_mode, NULL);
+
+static ssize_t store_ctlr_mode(struct device *dev,
+			       struct device_attribute *attr,
+			       const char *buf, size_t count)
+{
+	struct fcoe_ctlr_device *ctlr = dev_to_ctlr(dev);
+	char mode[FCOE_MAX_MODENAME_LEN + 1];
+
+	if (count > FCOE_MAX_MODENAME_LEN)
+		return -EINVAL;
+
+	strncpy(mode, buf, count);
+
+	if (mode[count - 1] == '\n')
+		mode[count - 1] = '\0';
+	else
+		mode[count] = '\0';
+
+	switch (ctlr->enabled) {
+	case FCOE_CTLR_ENABLED:
+		LIBFCOE_SYSFS_DBG(ctlr, "Cannot change mode when enabled.");
+		return -EBUSY;
+	case FCOE_CTLR_DISABLED:
+		if (!ctlr->f->set_fcoe_ctlr_mode) {
+			LIBFCOE_SYSFS_DBG(ctlr,
+					  "Mode change not supported by LLD.");
+			return -ENOTSUPP;
+		}
+
+		ctlr->mode = fcoe_parse_mode(mode);
+		if (ctlr->mode == FIP_CONN_TYPE_UNKNOWN) {
+			LIBFCOE_SYSFS_DBG(ctlr,
+					  "Unknown mode %s provided.", buf);
+			return -EINVAL;
+		}
+
+		ctlr->f->set_fcoe_ctlr_mode(ctlr);
+		LIBFCOE_SYSFS_DBG(ctlr, "Mode changed to %s.", buf);
+
+		return count;
+	case FCOE_CTLR_UNUSED:
+	default:
+		LIBFCOE_SYSFS_DBG(ctlr, "Mode change not supported.");
+		return -ENOTSUPP;
+	};
+}
+
+static FCOE_DEVICE_ATTR(ctlr, mode, S_IRUGO | S_IWUSR,
+			show_ctlr_mode, store_ctlr_mode);
+
+static ssize_t store_ctlr_enabled(struct device *dev,
+				  struct device_attribute *attr,
+				  const char *buf, size_t count)
+{
+	struct fcoe_ctlr_device *ctlr = dev_to_ctlr(dev);
+	int rc;
+
+	switch (ctlr->enabled) {
+	case FCOE_CTLR_ENABLED:
+		if (*buf == '1')
+			return count;
+		ctlr->enabled = FCOE_CTLR_DISABLED;
+		break;
+	case FCOE_CTLR_DISABLED:
+		if (*buf == '0')
+			return count;
+		ctlr->enabled = FCOE_CTLR_ENABLED;
+		break;
+	case FCOE_CTLR_UNUSED:
+		return -ENOTSUPP;
+	};
+
+	rc = ctlr->f->set_fcoe_ctlr_enabled(ctlr);
+	if (rc)
+		return rc;
+
+	return count;
+}
+
+static char *ctlr_enabled_state_names[] = {
+	[ FCOE_CTLR_ENABLED ]  = "1",
+	[ FCOE_CTLR_DISABLED ] = "0",
+};
+fcoe_enum_name_search(ctlr_enabled_state, ctlr_enabled_state,
+		      ctlr_enabled_state_names)
+#define FCOE_CTLR_ENABLED_MAX_NAMELEN 50
+
+static ssize_t show_ctlr_enabled_state(struct device *dev,
+				       struct device_attribute *attr,
+				       char *buf)
+{
+	struct fcoe_ctlr_device *ctlr = dev_to_ctlr(dev);
+	const char *name;
+
+	name = get_fcoe_ctlr_enabled_state_name(ctlr->enabled);
+	if (!name)
+		return -EINVAL;
+	return snprintf(buf, FCOE_CTLR_ENABLED_MAX_NAMELEN,
+			"%s\n", name);
+}
+
+static FCOE_DEVICE_ATTR(ctlr, enabled, S_IRUGO | S_IWUSR,
+			show_ctlr_enabled_state,
+			store_ctlr_enabled);
 
 static ssize_t
 store_private_fcoe_ctlr_fcf_dev_loss_tmo(struct device *dev,
@@ -354,6 +468,7 @@ static struct attribute_group fcoe_ctlr_lesb_attr_group = {
 
 static struct attribute *fcoe_ctlr_attrs[] = {
 	&device_attr_fcoe_ctlr_fcf_dev_loss_tmo.attr,
+	&device_attr_fcoe_ctlr_enabled.attr,
 	&device_attr_fcoe_ctlr_mode.attr,
 	NULL,
 };
@@ -438,9 +553,16 @@ struct device_type fcoe_fcf_device_type = {
 	.release = fcoe_fcf_device_release,
 };
 
+struct bus_attribute fcoe_bus_attr_group[] = {
+	__ATTR(ctlr_create, S_IWUSR, NULL, fcoe_ctlr_create_store),
+	__ATTR(ctlr_destroy, S_IWUSR, NULL, fcoe_ctlr_destroy_store),
+	__ATTR_NULL
+};
+
 struct bus_type fcoe_bus_type = {
 	.name = "fcoe",
 	.match = &fcoe_bus_match,
+	.bus_attrs = fcoe_bus_attr_group,
 };
 
 /**
@@ -561,6 +683,7 @@ struct fcoe_ctlr_device *fcoe_ctlr_device_add(struct device *parent,
 
 	ctlr->id = atomic_inc_return(&ctlr_num) - 1;
 	ctlr->f = f;
+	ctlr->mode = FIP_CONN_TYPE_FABRIC;
 	INIT_LIST_HEAD(&ctlr->fcfs);
 	mutex_init(&ctlr->lock);
 	ctlr->dev.parent = parent;

drivers/scsi/fcoe/fcoe_transport.c

@@ -627,6 +627,110 @@ static int libfcoe_device_notification(struct notifier_block *notifier,
 	return NOTIFY_OK;
 }
 
+ssize_t fcoe_ctlr_create_store(struct bus_type *bus,
+			       const char *buf, size_t count)
+{
+	struct net_device *netdev = NULL;
+	struct fcoe_transport *ft = NULL;
+	struct fcoe_ctlr_device *ctlr_dev = NULL;
+	int rc = 0;
+	int err;
+
+	mutex_lock(&ft_mutex);
+
+	netdev = fcoe_if_to_netdev(buf);
+	if (!netdev) {
+		LIBFCOE_TRANSPORT_DBG("Invalid device %s.\n", buf);
+		rc = -ENODEV;
+		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);
+		rc = -ENODEV;
+		goto out_putdev;
+	}
+
+	/* pass to transport create */
+	err = ft->alloc ? ft->alloc(netdev) : -ENODEV;
+	if (err) {
+		fcoe_del_netdev_mapping(netdev);
+		rc = -ENOMEM;
+		goto out_putdev;
+	}
+
+	err = fcoe_add_netdev_mapping(netdev, ft);
+	if (err) {
+		LIBFCOE_TRANSPORT_DBG("failed to add new netdev mapping "
+				      "for FCoE transport %s for %s.\n",
+				      ft->name, netdev->name);
+		rc = -ENODEV;
+		goto out_putdev;
+	}
+
+	LIBFCOE_TRANSPORT_DBG("transport %s %s to create fcoe on %s.\n",
+			      ft->name, (ctlr_dev) ? "succeeded" : "failed",
+			      netdev->name);
+
+out_putdev:
+	dev_put(netdev);
+out_nodev:
+	mutex_unlock(&ft_mutex);
+	if (rc)
+		return rc;
+	return count;
+}
+
+ssize_t fcoe_ctlr_destroy_store(struct bus_type *bus,
+				const char *buf, size_t count)
+{
+	int rc = -ENODEV;
+	struct net_device *netdev = NULL;
+	struct fcoe_transport *ft = NULL;
+
+	mutex_lock(&ft_mutex);
+
+	netdev = fcoe_if_to_netdev(buf);
+	if (!netdev) {
+		LIBFCOE_TRANSPORT_DBG("invalid device %s.\n", buf);
+		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(netdev);
+	if (rc)
+		goto out_putdev;
+
+	fcoe_del_netdev_mapping(netdev);
+	LIBFCOE_TRANSPORT_DBG("transport %s %s to destroy fcoe on %s.\n",
+			      ft->name, (rc) ? "failed" : "succeeded",
+			      netdev->name);
+	rc = count; /* required for successful return */
+out_putdev:
+	dev_put(netdev);
+out_nodev:
+	mutex_unlock(&ft_mutex);
+	return rc;
+}
+EXPORT_SYMBOL(fcoe_ctlr_destroy_store);
 
 /**
  * fcoe_transport_create() - Create a fcoe interface