1 /*
2  * INET         An implementation of the TCP/IP protocol suite for the LINUX
3  *              operating system.  NET  is implemented using the  BSD Socket
4  *              interface as the means of communication with the user level.
5  *
6  *              Definitions used by the ARCnet driver.
7  *
8  * Authors:     Avery Pennarun and David Woodhouse
9  *
10  *              This program is free software; you can redistribute it and/or
11  *              modify it under the terms of the GNU General Public License
12  *              as published by the Free Software Foundation; either version
13  *              2 of the License, or (at your option) any later version.
14  *
15  */
16 #ifndef _LINUX_ARCDEVICE_H
17 #define _LINUX_ARCDEVICE_H
18 
19 #include <asm/timex.h>
20 #include <linux/if_arcnet.h>
21 
22 #ifdef __KERNEL__
23 #include  <linux/irqreturn.h>
24 
25 /*
26  * RECON_THRESHOLD is the maximum number of RECON messages to receive
27  * within one minute before printing a "cabling problem" warning. The
28  * default value should be fine.
29  *
30  * After that, a "cabling restored" message will be printed on the next IRQ
31  * if no RECON messages have been received for 10 seconds.
32  *
33  * Do not define RECON_THRESHOLD at all if you want to disable this feature.
34  */
35 #define RECON_THRESHOLD 30
36 
37 
38 /*
39  * Define this to the minimum "timeout" value.  If a transmit takes longer
40  * than TX_TIMEOUT jiffies, Linux will abort the TX and retry.  On a large
41  * network, or one with heavy network traffic, this timeout may need to be
42  * increased.  The larger it is, though, the longer it will be between
43  * necessary transmits - don't set this too high.
44  */
45 #define TX_TIMEOUT (HZ * 200 / 1000)
46 
47 
48 /* Display warnings about the driver being an ALPHA version. */
49 #undef ALPHA_WARNING
50 
51 
52 /*
53  * Debugging bitflags: each option can be enabled individually.
54  *
55  * Note: only debug flags included in the ARCNET_DEBUG_MAX define will
56  *   actually be available.  GCC will (at least, GCC 2.7.0 will) notice
57  *   lines using a BUGLVL not in ARCNET_DEBUG_MAX and automatically optimize
58  *   them out.
59  */
60 #define D_NORMAL	1	/* important operational info             */
61 #define D_EXTRA		2	/* useful, but non-vital information      */
62 #define	D_INIT		4	/* show init/probe messages               */
63 #define D_INIT_REASONS	8	/* show reasons for discarding probes     */
64 #define D_RECON		32	/* print a message whenever token is lost */
65 #define D_PROTO		64	/* debug auto-protocol support            */
66 /* debug levels below give LOTS of output during normal operation! */
67 #define D_DURING	128	/* trace operations (including irq's)     */
68 #define D_TX	        256	/* show tx packets                        */
69 #define D_RX		512	/* show rx packets                        */
70 #define D_SKB		1024	/* show skb's                             */
71 #define D_SKB_SIZE	2048	/* show skb sizes			  */
72 #define D_TIMING	4096	/* show time needed to copy buffers to card */
73 #define D_DEBUG         8192    /* Very detailed debug line for line */
74 
75 #ifndef ARCNET_DEBUG_MAX
76 #define ARCNET_DEBUG_MAX (127)	/* change to ~0 if you want detailed debugging */
77 #endif
78 
79 #ifndef ARCNET_DEBUG
80 #define ARCNET_DEBUG (D_NORMAL|D_EXTRA)
81 #endif
82 extern int arcnet_debug;
83 
84 /* macros to simplify debug checking */
85 #define BUGLVL(x) if ((ARCNET_DEBUG_MAX)&arcnet_debug&(x))
86 #define BUGMSG2(x,msg,args...) do { BUGLVL(x) printk(msg, ## args); } while (0)
87 #define BUGMSG(x,msg,args...) \
88 	BUGMSG2(x, "%s%6s: " msg, \
89             x==D_NORMAL	? KERN_WARNING \
90             		: x < D_DURING ? KERN_INFO : KERN_DEBUG, \
91 	    dev->name , ## args)
92 
93 /* see how long a function call takes to run, expressed in CPU cycles */
94 #define TIME(name, bytes, call) BUGLVL(D_TIMING) { \
95 	    unsigned long _x, _y; \
96 	    _x = get_cycles(); \
97 	    call; \
98 	    _y = get_cycles(); \
99 	    BUGMSG(D_TIMING, \
100 	       "%s: %d bytes in %lu cycles == " \
101 	       "%lu Kbytes/100Mcycle\n",\
102 		   name, bytes, _y - _x, \
103 		   100000000 / 1024 * bytes / (_y - _x + 1));\
104 	} \
105 	else { \
106 		    call;\
107 	}
108 
109 
110 /*
111  * Time needed to reset the card - in ms (milliseconds).  This works on my
112  * SMC PC100.  I can't find a reference that tells me just how long I
113  * should wait.
114  */
115 #define RESETtime (300)
116 
117 /*
118  * These are the max/min lengths of packet payload, not including the
119  * arc_hardware header, but definitely including the soft header.
120  *
121  * Note: packet sizes 254, 255, 256 are impossible because of the way
122  * ARCnet registers work  That's why RFC1201 defines "exception" packets.
123  * In non-RFC1201 protocols, we have to just tack some extra bytes on the
124  * end.
125  */
126 #define MTU	253		/* normal packet max size */
127 #define MinTU	257		/* extended packet min size */
128 #define XMTU	508		/* extended packet max size */
129 
130 /* status/interrupt mask bit fields */
131 #define TXFREEflag	0x01	/* transmitter available */
132 #define TXACKflag       0x02	/* transmitted msg. ackd */
133 #define RECONflag       0x04	/* network reconfigured */
134 #define TESTflag        0x08	/* test flag */
135 #define EXCNAKflag      0x08    /* excesive nak flag */
136 #define RESETflag       0x10	/* power-on-reset */
137 #define RES1flag        0x20	/* reserved - usually set by jumper */
138 #define RES2flag        0x40	/* reserved - usually set by jumper */
139 #define NORXflag        0x80	/* receiver inhibited */
140 
141 /* Flags used for IO-mapped memory operations */
142 #define AUTOINCflag     0x40	/* Increase location with each access */
143 #define IOMAPflag       0x02	/* (for 90xx) Use IO mapped memory, not mmap */
144 #define ENABLE16flag    0x80	/* (for 90xx) Enable 16-bit mode */
145 
146 /* in the command register, the following bits have these meanings:
147  *                0-2     command
148  *                3-4     page number (for enable rcv/xmt command)
149  *                 7      receive broadcasts
150  */
151 #define NOTXcmd         0x01	/* disable transmitter */
152 #define NORXcmd         0x02	/* disable receiver */
153 #define TXcmd           0x03	/* enable transmitter */
154 #define RXcmd           0x04	/* enable receiver */
155 #define CONFIGcmd       0x05	/* define configuration */
156 #define CFLAGScmd       0x06	/* clear flags */
157 #define TESTcmd         0x07	/* load test flags */
158 
159 /* flags for "clear flags" command */
160 #define RESETclear      0x08	/* power-on-reset */
161 #define CONFIGclear     0x10	/* system reconfigured */
162 
163 #define EXCNAKclear     0x0E    /* Clear and acknowledge the excive nak bit */
164 
165 /* flags for "load test flags" command */
166 #define TESTload        0x08	/* test flag (diagnostic) */
167 
168 /* byte deposited into first address of buffers on reset */
169 #define TESTvalue       0321	/* that's octal for 0xD1 :) */
170 
171 /* for "enable receiver" command */
172 #define RXbcasts        0x80	/* receive broadcasts */
173 
174 /* flags for "define configuration" command */
175 #define NORMALconf      0x00	/* 1-249 byte packets */
176 #define EXTconf         0x08	/* 250-504 byte packets */
177 
178 /* card feature flags, set during auto-detection.
179  * (currently only used by com20020pci)
180  */
181 #define ARC_IS_5MBIT    1   /* card default speed is 5MBit */
182 #define ARC_CAN_10MBIT  2   /* card uses COM20022, supporting 10MBit,
183 				 but default is 2.5MBit. */
184 
185 
186 /* information needed to define an encapsulation driver */
187 struct ArcProto {
188 	char suffix;		/* a for RFC1201, e for ether-encap, etc. */
189 	int mtu;		/* largest possible packet */
190 	int is_ip;              /* This is a ip plugin - not a raw thing */
191 
192 	void (*rx) (struct net_device * dev, int bufnum,
193 		    struct archdr * pkthdr, int length);
194 	int (*build_header) (struct sk_buff * skb, struct net_device *dev,
195 			     unsigned short ethproto, uint8_t daddr);
196 
197 	/* these functions return '1' if the skb can now be freed */
198 	int (*prepare_tx) (struct net_device * dev, struct archdr * pkt, int length,
199 			   int bufnum);
200 	int (*continue_tx) (struct net_device * dev, int bufnum);
201 	int (*ack_tx) (struct net_device * dev, int acked);
202 };
203 
204 extern struct ArcProto *arc_proto_map[256], *arc_proto_default,
205 	*arc_bcast_proto, *arc_raw_proto;
206 
207 
208 /*
209  * "Incoming" is information needed for each address that could be sending
210  * to us.  Mostly for partially-received split packets.
211  */
212 struct Incoming {
213 	struct sk_buff *skb;	/* packet data buffer             */
214 	__be16 sequence;	/* sequence number of assembly    */
215 	uint8_t lastpacket,	/* number of last packet (from 1) */
216 		numpackets;	/* number of packets in split     */
217 };
218 
219 
220 /* only needed for RFC1201 */
221 struct Outgoing {
222 	struct ArcProto *proto;	/* protocol driver that owns this:
223 				 *   if NULL, no packet is pending.
224 				 */
225 	struct sk_buff *skb;	/* buffer from upper levels */
226 	struct archdr *pkt;	/* a pointer into the skb */
227 	uint16_t length,	/* bytes total */
228 		dataleft,	/* bytes left */
229 		segnum,		/* segment being sent */
230 		numsegs;	/* number of segments */
231 };
232 
233 
234 struct arcnet_local {
235 	uint8_t config,		/* current value of CONFIG register */
236 		timeout,	/* Extended timeout for COM20020 */
237 		backplane,	/* Backplane flag for COM20020 */
238 		clockp,		/* COM20020 clock divider */
239 		clockm,		/* COM20020 clock multiplier flag */
240 		setup,		/* Contents of setup1 register */
241 		setup2,		/* Contents of setup2 register */
242 		intmask;	/* current value of INTMASK register */
243 	uint8_t default_proto[256];	/* default encap to use for each host */
244 	int	cur_tx,		/* buffer used by current transmit, or -1 */
245 		next_tx,	/* buffer where a packet is ready to send */
246 		cur_rx;		/* current receive buffer */
247 	int	lastload_dest,	/* can last loaded packet be acked? */
248 		lasttrans_dest;	/* can last TX'd packet be acked? */
249 	int	timed_out;	/* need to process TX timeout and drop packet */
250 	unsigned long last_timeout;	/* time of last reported timeout */
251 	char *card_name;	/* card ident string */
252 	int card_flags;		/* special card features */
253 
254 
255 	/* On preemtive and SMB a lock is needed */
256 	spinlock_t lock;
257 
258 	/*
259 	 * Buffer management: an ARCnet card has 4 x 512-byte buffers, each of
260 	 * which can be used for either sending or receiving.  The new dynamic
261 	 * buffer management routines use a simple circular queue of available
262 	 * buffers, and take them as they're needed.  This way, we simplify
263 	 * situations in which we (for example) want to pre-load a transmit
264 	 * buffer, or start receiving while we copy a received packet to
265 	 * memory.
266 	 *
267 	 * The rules: only the interrupt handler is allowed to _add_ buffers to
268 	 * the queue; thus, this doesn't require a lock.  Both the interrupt
269 	 * handler and the transmit function will want to _remove_ buffers, so
270 	 * we need to handle the situation where they try to do it at the same
271 	 * time.
272 	 *
273 	 * If next_buf == first_free_buf, the queue is empty.  Since there are
274 	 * only four possible buffers, the queue should never be full.
275 	 */
276 	atomic_t buf_lock;
277 	int buf_queue[5];
278 	int next_buf, first_free_buf;
279 
280 	/* network "reconfiguration" handling */
281 	unsigned long first_recon; /* time of "first" RECON message to count */
282 	unsigned long last_recon;  /* time of most recent RECON */
283 	int num_recons;		/* number of RECONs between first and last. */
284 	int network_down;	/* do we think the network is down? */
285 
286 	int excnak_pending;    /* We just got an excesive nak interrupt */
287 
288 	struct {
289 		uint16_t sequence;	/* sequence number (incs with each packet) */
290 		__be16 aborted_seq;
291 
292 		struct Incoming incoming[256];	/* one from each address */
293 	} rfc1201;
294 
295 	/* really only used by rfc1201, but we'll pretend it's not */
296 	struct Outgoing outgoing;	/* packet currently being sent */
297 
298 	/* hardware-specific functions */
299 	struct {
300 		struct module *owner;
301 		void (*command) (struct net_device * dev, int cmd);
302 		int (*status) (struct net_device * dev);
303 		void (*intmask) (struct net_device * dev, int mask);
304 		int (*reset) (struct net_device * dev, int really_reset);
305 		void (*open) (struct net_device * dev);
306 		void (*close) (struct net_device * dev);
307 
308 		void (*copy_to_card) (struct net_device * dev, int bufnum, int offset,
309 				      void *buf, int count);
310 		void (*copy_from_card) (struct net_device * dev, int bufnum, int offset,
311 					void *buf, int count);
312 	} hw;
313 
314 	void __iomem *mem_start;	/* pointer to ioremap'ed MMIO */
315 };
316 
317 
318 #define ARCRESET(x)  (lp->hw.reset(dev, (x)))
319 #define ACOMMAND(x)  (lp->hw.command(dev, (x)))
320 #define ASTATUS()    (lp->hw.status(dev))
321 #define AINTMASK(x)  (lp->hw.intmask(dev, (x)))
322 
323 
324 
325 #if ARCNET_DEBUG_MAX & D_SKB
326 void arcnet_dump_skb(struct net_device *dev, struct sk_buff *skb, char *desc);
327 #else
328 #define arcnet_dump_skb(dev,skb,desc) ;
329 #endif
330 
331 void arcnet_unregister_proto(struct ArcProto *proto);
332 irqreturn_t arcnet_interrupt(int irq, void *dev_id);
333 struct net_device *alloc_arcdev(const char *name);
334 
335 int arcnet_open(struct net_device *dev);
336 int arcnet_close(struct net_device *dev);
337 netdev_tx_t arcnet_send_packet(struct sk_buff *skb,
338 				     struct net_device *dev);
339 void arcnet_timeout(struct net_device *dev);
340 
341 #endif				/* __KERNEL__ */
342 #endif				/* _LINUX_ARCDEVICE_H */
343