1 /*
2  * Copyright (c) 2008-2009 Cisco Systems, Inc.  All rights reserved.
3  * Copyright (c) 2007-2008 Intel Corporation.  All rights reserved.
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms and conditions of the GNU General Public License,
7  * version 2, as published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12  * more details.
13  *
14  * You should have received a copy of the GNU General Public License along with
15  * this program; if not, write to the Free Software Foundation, Inc.,
16  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
17  *
18  * Maintained at www.Open-FCoE.org
19  */
20 
21 #ifndef _LIBFCOE_H
22 #define _LIBFCOE_H
23 
24 #include <linux/etherdevice.h>
25 #include <linux/if_ether.h>
26 #include <linux/netdevice.h>
27 #include <linux/skbuff.h>
28 #include <linux/workqueue.h>
29 #include <linux/random.h>
30 #include <scsi/fc/fc_fcoe.h>
31 #include <scsi/libfc.h>
32 
33 #define FCOE_MAX_CMD_LEN	16	/* Supported CDB length */
34 
35 /*
36  * Max MTU for FCoE: 14 (FCoE header) + 24 (FC header) + 2112 (max FC payload)
37  * + 4 (FC CRC) + 4 (FCoE trailer) =  2158 bytes
38  */
39 #define FCOE_MTU	2158
40 
41 /*
42  * FIP tunable parameters.
43  */
44 #define FCOE_CTLR_START_DELAY	2000	/* mS after first adv. to choose FCF */
45 #define FCOE_CTRL_SOL_TOV	2000	/* min. solicitation interval (mS) */
46 #define FCOE_CTLR_FCF_LIMIT	20	/* max. number of FCF entries */
47 #define FCOE_CTLR_VN2VN_LOGIN_LIMIT 3	/* max. VN2VN rport login retries */
48 
49 /**
50  * enum fip_state - internal state of FCoE controller.
51  * @FIP_ST_DISABLED: 	controller has been disabled or not yet enabled.
52  * @FIP_ST_LINK_WAIT:	the physical link is down or unusable.
53  * @FIP_ST_AUTO:	determining whether to use FIP or non-FIP mode.
54  * @FIP_ST_NON_FIP:	non-FIP mode selected.
55  * @FIP_ST_ENABLED:	FIP mode selected.
56  * @FIP_ST_VNMP_START:	VN2VN multipath mode start, wait
57  * @FIP_ST_VNMP_PROBE1:	VN2VN sent first probe, listening
58  * @FIP_ST_VNMP_PROBE2:	VN2VN sent second probe, listening
59  * @FIP_ST_VNMP_CLAIM:	VN2VN sent claim, waiting for responses
60  * @FIP_ST_VNMP_UP:	VN2VN multipath mode operation
61  */
62 enum fip_state {
63 	FIP_ST_DISABLED,
64 	FIP_ST_LINK_WAIT,
65 	FIP_ST_AUTO,
66 	FIP_ST_NON_FIP,
67 	FIP_ST_ENABLED,
68 	FIP_ST_VNMP_START,
69 	FIP_ST_VNMP_PROBE1,
70 	FIP_ST_VNMP_PROBE2,
71 	FIP_ST_VNMP_CLAIM,
72 	FIP_ST_VNMP_UP,
73 };
74 
75 /*
76  * Modes:
77  * The mode is the state that is to be entered after link up.
78  * It must not change after fcoe_ctlr_init() sets it.
79  */
80 #define FIP_MODE_AUTO		FIP_ST_AUTO
81 #define FIP_MODE_NON_FIP	FIP_ST_NON_FIP
82 #define FIP_MODE_FABRIC		FIP_ST_ENABLED
83 #define FIP_MODE_VN2VN		FIP_ST_VNMP_START
84 
85 /**
86  * struct fcoe_ctlr - FCoE Controller and FIP state
87  * @state:	   internal FIP state for network link and FIP or non-FIP mode.
88  * @mode:	   LLD-selected mode.
89  * @lp:		   &fc_lport: libfc local port.
90  * @sel_fcf:	   currently selected FCF, or NULL.
91  * @fcfs:	   list of discovered FCFs.
92  * @fcf_count:	   number of discovered FCF entries.
93  * @sol_time:	   time when a multicast solicitation was last sent.
94  * @sel_time:	   time after which to select an FCF.
95  * @port_ka_time:  time of next port keep-alive.
96  * @ctlr_ka_time:  time of next controller keep-alive.
97  * @timer:	   timer struct used for all delayed events.
98  * @timer_work:	   &work_struct for doing keep-alives and resets.
99  * @recv_work:	   &work_struct for receiving FIP frames.
100  * @fip_recv_list: list of received FIP frames.
101  * @flogi_req:	   clone of FLOGI request sent
102  * @rnd_state:	   state for pseudo-random number generator.
103  * @port_id:	   proposed or selected local-port ID.
104  * @user_mfs:	   configured maximum FC frame size, including FC header.
105  * @flogi_oxid:    exchange ID of most recent fabric login.
106  * @flogi_req_send: send of FLOGI requested
107  * @flogi_count:   number of FLOGI attempts in AUTO mode.
108  * @map_dest:	   use the FC_MAP mode for destination MAC addresses.
109  * @spma:	   supports SPMA server-provided MACs mode
110  * @probe_tries:   number of FC_IDs probed
111  * @dest_addr:	   MAC address of the selected FC forwarder.
112  * @ctl_src_addr:  the native MAC address of our local port.
113  * @send:	   LLD-supplied function to handle sending FIP Ethernet frames
114  * @update_mac:    LLD-supplied function to handle changes to MAC addresses.
115  * @get_src_addr:  LLD-supplied function to supply a source MAC address.
116  * @ctlr_mutex:	   lock protecting this structure.
117  * @ctlr_lock:     spinlock covering flogi_req
118  *
119  * This structure is used by all FCoE drivers.  It contains information
120  * needed by all FCoE low-level drivers (LLDs) as well as internal state
121  * for FIP, and fields shared with the LLDS.
122  */
123 struct fcoe_ctlr {
124 	enum fip_state state;
125 	enum fip_state mode;
126 	struct fc_lport *lp;
127 	struct fcoe_fcf *sel_fcf;
128 	struct list_head fcfs;
129 	u16 fcf_count;
130 	unsigned long sol_time;
131 	unsigned long sel_time;
132 	unsigned long port_ka_time;
133 	unsigned long ctlr_ka_time;
134 	struct timer_list timer;
135 	struct work_struct timer_work;
136 	struct work_struct recv_work;
137 	struct sk_buff_head fip_recv_list;
138 	struct sk_buff *flogi_req;
139 
140 	struct rnd_state rnd_state;
141 	u32 port_id;
142 
143 	u16 user_mfs;
144 	u16 flogi_oxid;
145 	u8 flogi_req_send;
146 	u8 flogi_count;
147 	u8 map_dest;
148 	u8 spma;
149 	u8 probe_tries;
150 	u8 dest_addr[ETH_ALEN];
151 	u8 ctl_src_addr[ETH_ALEN];
152 
153 	void (*send)(struct fcoe_ctlr *, struct sk_buff *);
154 	void (*update_mac)(struct fc_lport *, u8 *addr);
155 	u8 * (*get_src_addr)(struct fc_lport *);
156 	struct mutex ctlr_mutex;
157 	spinlock_t ctlr_lock;
158 };
159 
160 /**
161  * struct fcoe_fcf - Fibre-Channel Forwarder
162  * @list:	 list linkage
163  * @time:	 system time (jiffies) when an advertisement was last received
164  * @switch_name: WWN of switch from advertisement
165  * @fabric_name: WWN of fabric from advertisement
166  * @fc_map:	 FC_MAP value from advertisement
167  * @fcf_mac:	 Ethernet address of the FCF
168  * @vfid:	 virtual fabric ID
169  * @pri:	 selection priority, smaller values are better
170  * @flogi_sent:	 current FLOGI sent to this FCF
171  * @flags:	 flags received from advertisement
172  * @fka_period:	 keep-alive period, in jiffies
173  *
174  * A Fibre-Channel Forwarder (FCF) is the entity on the Ethernet that
175  * passes FCoE frames on to an FC fabric.  This structure represents
176  * one FCF from which advertisements have been received.
177  *
178  * When looking up an FCF, @switch_name, @fabric_name, @fc_map, @vfid, and
179  * @fcf_mac together form the lookup key.
180  */
181 struct fcoe_fcf {
182 	struct list_head list;
183 	unsigned long time;
184 
185 	u64 switch_name;
186 	u64 fabric_name;
187 	u32 fc_map;
188 	u16 vfid;
189 	u8 fcf_mac[ETH_ALEN];
190 
191 	u8 pri;
192 	u8 flogi_sent;
193 	u16 flags;
194 	u32 fka_period;
195 	u8 fd_flags:1;
196 };
197 
198 /**
199  * struct fcoe_rport - VN2VN remote port
200  * @time:	time of create or last beacon packet received from node
201  * @fcoe_len:	max FCoE frame size, not including VLAN or Ethernet headers
202  * @flags:	flags from probe or claim
203  * @login_count: number of unsuccessful rport logins to this port
204  * @enode_mac:	E_Node control MAC address
205  * @vn_mac:	VN_Node assigned MAC address for data
206  */
207 struct fcoe_rport {
208 	unsigned long time;
209 	u16 fcoe_len;
210 	u16 flags;
211 	u8 login_count;
212 	u8 enode_mac[ETH_ALEN];
213 	u8 vn_mac[ETH_ALEN];
214 };
215 
216 /* FIP API functions */
217 void fcoe_ctlr_init(struct fcoe_ctlr *, enum fip_state);
218 void fcoe_ctlr_destroy(struct fcoe_ctlr *);
219 void fcoe_ctlr_link_up(struct fcoe_ctlr *);
220 int fcoe_ctlr_link_down(struct fcoe_ctlr *);
221 int fcoe_ctlr_els_send(struct fcoe_ctlr *, struct fc_lport *, struct sk_buff *);
222 void fcoe_ctlr_recv(struct fcoe_ctlr *, struct sk_buff *);
223 int fcoe_ctlr_recv_flogi(struct fcoe_ctlr *, struct fc_lport *,
224 			 struct fc_frame *);
225 
226 /* libfcoe funcs */
227 u64 fcoe_wwn_from_mac(unsigned char mac[], unsigned int, unsigned int);
228 int fcoe_libfc_config(struct fc_lport *, struct fcoe_ctlr *,
229 		      const struct libfc_function_template *, int init_fcp);
230 u32 fcoe_fc_crc(struct fc_frame *fp);
231 int fcoe_start_io(struct sk_buff *skb);
232 
233 /**
234  * is_fip_mode() - returns true if FIP mode selected.
235  * @fip:	FCoE controller.
236  */
is_fip_mode(struct fcoe_ctlr * fip)237 static inline bool is_fip_mode(struct fcoe_ctlr *fip)
238 {
239 	return fip->state == FIP_ST_ENABLED;
240 }
241 
242 /* helper for FCoE SW HBA drivers, can include subven and subdev if needed. The
243  * modpost would use pci_device_id table to auto-generate formatted module alias
244  * into the corresponding .mod.c file, but there may or may not be a pci device
245  * id table for FCoE drivers so we use the following helper for build the fcoe
246  * driver module alias.
247  */
248 #define MODULE_ALIAS_FCOE_PCI(ven, dev) \
249 	MODULE_ALIAS("fcoe-pci:"	\
250 		"v" __stringify(ven)	\
251 		"d" __stringify(dev) "sv*sd*bc*sc*i*")
252 
253 /* the name of the default FCoE transport driver fcoe.ko */
254 #define FCOE_TRANSPORT_DEFAULT	"fcoe"
255 
256 /* struct fcoe_transport - The FCoE transport interface
257  * @name:	a vendor specific name for their FCoE transport driver
258  * @attached:	whether this transport is already attached
259  * @list:	list linkage to all attached transports
260  * @match:	handler to allow the transport driver to match up a given netdev
261  * @create:	handler to sysfs entry of create for FCoE instances
262  * @destroy:	handler to sysfs entry of destroy for FCoE instances
263  * @enable:	handler to sysfs entry of enable for FCoE instances
264  * @disable:	handler to sysfs entry of disable for FCoE instances
265  */
266 struct fcoe_transport {
267 	char name[IFNAMSIZ];
268 	bool attached;
269 	struct list_head list;
270 	bool (*match) (struct net_device *device);
271 	int (*create) (struct net_device *device, enum fip_state fip_mode);
272 	int (*destroy) (struct net_device *device);
273 	int (*enable) (struct net_device *device);
274 	int (*disable) (struct net_device *device);
275 };
276 
277 /**
278  * struct fcoe_percpu_s - The context for FCoE receive thread(s)
279  * @thread:	    The thread context
280  * @fcoe_rx_list:   The queue of pending packets to process
281  * @page:	    The memory page for calculating frame trailer CRCs
282  * @crc_eof_offset: The offset into the CRC page pointing to available
283  *		    memory for a new trailer
284  */
285 struct fcoe_percpu_s {
286 	struct task_struct *thread;
287 	struct sk_buff_head fcoe_rx_list;
288 	struct page *crc_eof_page;
289 	int crc_eof_offset;
290 };
291 
292 /**
293  * struct fcoe_port - The FCoE private structure
294  * @priv:		       The associated fcoe interface. The structure is
295  *			       defined by the low level driver
296  * @lport:		       The associated local port
297  * @fcoe_pending_queue:	       The pending Rx queue of skbs
298  * @fcoe_pending_queue_active: Indicates if the pending queue is active
299  * @max_queue_depth:	       Max queue depth of pending queue
300  * @min_queue_depth:	       Min queue depth of pending queue
301  * @timer:		       The queue timer
302  * @destroy_work:	       Handle for work context
303  *			       (to prevent RTNL deadlocks)
304  * @data_srt_addr:	       Source address for data
305  *
306  * An instance of this structure is to be allocated along with the
307  * Scsi_Host and libfc fc_lport structures.
308  */
309 struct fcoe_port {
310 	void		      *priv;
311 	struct fc_lport	      *lport;
312 	struct sk_buff_head   fcoe_pending_queue;
313 	u8		      fcoe_pending_queue_active;
314 	u32		      max_queue_depth;
315 	u32		      min_queue_depth;
316 	struct timer_list     timer;
317 	struct work_struct    destroy_work;
318 	u8		      data_src_addr[ETH_ALEN];
319 };
320 void fcoe_clean_pending_queue(struct fc_lport *);
321 void fcoe_check_wait_queue(struct fc_lport *lport, struct sk_buff *skb);
322 void fcoe_queue_timer(ulong lport);
323 int fcoe_get_paged_crc_eof(struct sk_buff *skb, int tlen,
324 			   struct fcoe_percpu_s *fps);
325 
326 /**
327  * struct netdev_list
328  * A mapping from netdevice to fcoe_transport
329  */
330 struct fcoe_netdev_mapping {
331 	struct list_head list;
332 	struct net_device *netdev;
333 	struct fcoe_transport *ft;
334 };
335 
336 /* fcoe transports registration and deregistration */
337 int fcoe_transport_attach(struct fcoe_transport *ft);
338 int fcoe_transport_detach(struct fcoe_transport *ft);
339 
340 #endif /* _LIBFCOE_H */
341