[PATCH] kexec code cleanup
[linux-2.6] / drivers / char / ip2 / i2lib.c
1 /*******************************************************************************
2 *
3 *   (c) 1999 by Computone Corporation
4 *
5 ********************************************************************************
6 *
7 *
8 *   PACKAGE:     Linux tty Device Driver for IntelliPort family of multiport
9 *                serial I/O controllers.
10 *
11 *   DESCRIPTION: High-level interface code for the device driver. Uses the
12 *                Extremely Low Level Interface Support (i2ellis.c). Provides an
13 *                interface to the standard loadware, to support drivers or
14 *                application code. (This is included source code, not a separate
15 *                compilation module.)
16 *
17 *******************************************************************************/
18 //------------------------------------------------------------------------------
19 // Note on Strategy:
20 // Once the board has been initialized, it will interrupt us when:
21 // 1) It has something in the fifo for us to read (incoming data, flow control
22 // packets, or whatever).
23 // 2) It has stripped whatever we have sent last time in the FIFO (and
24 // consequently is ready for more).
25 //
26 // Note also that the buffer sizes declared in i2lib.h are VERY SMALL. This
27 // worsens performance considerably, but is done so that a great many channels
28 // might use only a little memory.
29 //------------------------------------------------------------------------------
30
31 //------------------------------------------------------------------------------
32 // Revision History:
33 //
34 // 0.00 -  4/16/91 --- First Draft
35 // 0.01 -  4/29/91 --- 1st beta release
36 // 0.02 -  6/14/91 --- Changes to allow small model compilation
37 // 0.03 -  6/17/91 MAG Break reporting protected from interrupts routines with
38 //                     in-line asm added for moving data to/from ring buffers,
39 //                     replacing a variety of methods used previously.
40 // 0.04 -  6/21/91 MAG Initial flow-control packets not queued until
41 //                     i2_enable_interrupts time. Former versions would enqueue
42 //                     them at i2_init_channel time, before we knew how many
43 //                     channels were supposed to exist!
44 // 0.05 - 10/12/91 MAG Major changes: works through the ellis.c routines now;
45 //                     supports new 16-bit protocol and expandable boards.
46 //      - 10/24/91 MAG Most changes in place and stable.
47 // 0.06 -  2/20/92 MAG Format of CMD_HOTACK corrected: the command takes no
48 //                     argument.
49 // 0.07 -- 3/11/92 MAG Support added to store special packet types at interrupt
50 //                     level (mostly responses to specific commands.)
51 // 0.08 -- 3/30/92 MAG Support added for STAT_MODEM packet
52 // 0.09 -- 6/24/93 MAG i2Link... needed to update number of boards BEFORE
53 //                     turning on the interrupt.
54 // 0.10 -- 6/25/93 MAG To avoid gruesome death from a bad board, we sanity check
55 //                     some incoming.
56 //
57 // 1.1  - 12/25/96 AKM Linux version.
58 //      - 10/09/98 DMC Revised Linux version.
59 //------------------------------------------------------------------------------
60
61 //************
62 //* Includes *
63 //************
64
65 #include <linux/sched.h>
66 #include "i2lib.h"
67
68
69 //***********************
70 //* Function Prototypes *
71 //***********************
72 static void i2QueueNeeds(i2eBordStrPtr, i2ChanStrPtr, int);
73 static i2ChanStrPtr i2DeQueueNeeds(i2eBordStrPtr, int );
74 static void i2StripFifo(i2eBordStrPtr);
75 static void i2StuffFifoBypass(i2eBordStrPtr);
76 static void i2StuffFifoFlow(i2eBordStrPtr);
77 static void i2StuffFifoInline(i2eBordStrPtr);
78 static int i2RetryFlushOutput(i2ChanStrPtr);
79
80 // Not a documented part of the library routines (careful...) but the Diagnostic
81 // i2diag.c finds them useful to help the throughput in certain limited
82 // single-threaded operations.
83 static void iiSendPendingMail(i2eBordStrPtr);
84 static void serviceOutgoingFifo(i2eBordStrPtr);
85
86 // Functions defined in ip2.c as part of interrupt handling
87 static void do_input(void *);
88 static void do_status(void *);
89
90 //***************
91 //* Debug  Data *
92 //***************
93 #ifdef DEBUG_FIFO
94
95 unsigned char DBGBuf[0x4000];
96 unsigned short I = 0;
97
98 static void
99 WriteDBGBuf(char *s, unsigned char *src, unsigned short n ) 
100 {
101         char *p = src;
102
103         // XXX: We need a spin lock here if we ever use this again
104
105         while (*s) {    // copy label
106                 DBGBuf[I] = *s++;
107                 I = I++ & 0x3fff;
108         }
109         while (n--) {   // copy data
110                 DBGBuf[I] = *p++;
111                 I = I++ & 0x3fff;
112         }
113 }
114
115 static void
116 fatality(i2eBordStrPtr pB )
117 {
118         int i;
119
120         for (i=0;i<sizeof(DBGBuf);i++) {
121                 if ((i%16) == 0)
122                         printk("\n%4x:",i);
123                 printk("%02x ",DBGBuf[i]);
124         }
125         printk("\n");
126         for (i=0;i<sizeof(DBGBuf);i++) {
127                 if ((i%16) == 0)
128                         printk("\n%4x:",i);
129                 if (DBGBuf[i] >= ' ' && DBGBuf[i] <= '~') {
130                         printk(" %c ",DBGBuf[i]);
131                 } else {
132                         printk(" . ");
133                 }
134         }
135         printk("\n");
136         printk("Last index %x\n",I);
137 }
138 #endif /* DEBUG_FIFO */
139
140 //********
141 //* Code *
142 //********
143
144 static inline int
145 i2Validate ( i2ChanStrPtr pCh )
146 {
147         //ip2trace(pCh->port_index, ITRC_VERIFY,ITRC_ENTER,2,pCh->validity,
148         //      (CHANNEL_MAGIC | CHANNEL_SUPPORT));
149         return ((pCh->validity & (CHANNEL_MAGIC_BITS | CHANNEL_SUPPORT)) 
150                           == (CHANNEL_MAGIC | CHANNEL_SUPPORT));
151 }
152
153 //******************************************************************************
154 // Function:   iiSendPendingMail(pB)
155 // Parameters: Pointer to a board structure
156 // Returns:    Nothing
157 //
158 // Description:
159 // If any outgoing mail bits are set and there is outgoing mailbox is empty,
160 // send the mail and clear the bits.
161 //******************************************************************************
162 static inline void
163 iiSendPendingMail(i2eBordStrPtr pB)
164 {
165         if (pB->i2eOutMailWaiting && (!pB->i2eWaitingForEmptyFifo) )
166         {
167                 if (iiTrySendMail(pB, pB->i2eOutMailWaiting))
168                 {
169                         /* If we were already waiting for fifo to empty,
170                          * or just sent MB_OUT_STUFFED, then we are
171                          * still waiting for it to empty, until we should
172                          * receive an MB_IN_STRIPPED from the board.
173                          */
174                         pB->i2eWaitingForEmptyFifo |=
175                                 (pB->i2eOutMailWaiting & MB_OUT_STUFFED);
176                         pB->i2eOutMailWaiting = 0;
177                         pB->SendPendingRetry = 0;
178                 } else {
179 /*              The only time we hit this area is when "iiTrySendMail" has
180                 failed.  That only occurs when the outbound mailbox is
181                 still busy with the last message.  We take a short breather
182                 to let the board catch up with itself and then try again.
183                 16 Retries is the limit - then we got a borked board.
184                         /\/\|=mhw=|\/\/                         */
185
186                         if( ++pB->SendPendingRetry < 16 ) {
187
188                                 init_timer( &(pB->SendPendingTimer) );
189                                 pB->SendPendingTimer.expires  = jiffies + 1;
190                                 pB->SendPendingTimer.function = (void*)(unsigned long)iiSendPendingMail;
191                                 pB->SendPendingTimer.data     = (unsigned long)pB;
192                                 add_timer( &(pB->SendPendingTimer) );
193                         } else {
194                                 printk( KERN_ERR "IP2: iiSendPendingMail unable to queue outbound mail\n" );
195                         }
196                 }
197         }
198 }
199
200 //******************************************************************************
201 // Function:   i2InitChannels(pB, nChannels, pCh)
202 // Parameters: Pointer to Ellis Board structure
203 //             Number of channels to initialize
204 //             Pointer to first element in an array of channel structures
205 // Returns:    Success or failure
206 //
207 // Description:
208 //
209 // This function patches pointers, back-pointers, and initializes all the
210 // elements in the channel structure array.
211 //
212 // This should be run after the board structure is initialized, through having
213 // loaded the standard loadware (otherwise it complains).
214 //
215 // In any case, it must be done before any serious work begins initializing the
216 // irq's or sending commands...
217 //
218 //******************************************************************************
219 static int
220 i2InitChannels ( i2eBordStrPtr pB, int nChannels, i2ChanStrPtr pCh)
221 {
222         int index, stuffIndex;
223         i2ChanStrPtr *ppCh;
224         
225         if (pB->i2eValid != I2E_MAGIC) {
226                 COMPLETE(pB, I2EE_BADMAGIC);
227         }
228         if (pB->i2eState != II_STATE_STDLOADED) {
229                 COMPLETE(pB, I2EE_BADSTATE);
230         }
231
232         LOCK_INIT(&pB->read_fifo_spinlock);
233         LOCK_INIT(&pB->write_fifo_spinlock);
234         LOCK_INIT(&pB->Dbuf_spinlock);
235         LOCK_INIT(&pB->Bbuf_spinlock);
236         LOCK_INIT(&pB->Fbuf_spinlock);
237         
238         // NO LOCK needed yet - this is init
239
240         pB->i2eChannelPtr = pCh;
241         pB->i2eChannelCnt = nChannels;
242
243         pB->i2Fbuf_strip = pB->i2Fbuf_stuff = 0;
244         pB->i2Dbuf_strip = pB->i2Dbuf_stuff = 0;
245         pB->i2Bbuf_strip = pB->i2Bbuf_stuff = 0;
246
247         pB->SendPendingRetry = 0;
248
249         memset ( pCh, 0, sizeof (i2ChanStr) * nChannels );
250
251         for (index = stuffIndex = 0, ppCh = (i2ChanStrPtr *)(pB->i2Fbuf);
252                   nChannels && index < ABS_MOST_PORTS;
253                   index++)
254         {
255                 if ( !(pB->i2eChannelMap[index >> 4] & (1 << (index & 0xf)) ) ) {
256                         continue;
257                 }
258                 LOCK_INIT(&pCh->Ibuf_spinlock);
259                 LOCK_INIT(&pCh->Obuf_spinlock);
260                 LOCK_INIT(&pCh->Cbuf_spinlock);
261                 LOCK_INIT(&pCh->Pbuf_spinlock);
262                 // NO LOCK needed yet - this is init
263                 // Set up validity flag according to support level
264                 if (pB->i2eGoodMap[index >> 4] & (1 << (index & 0xf)) ) {
265                         pCh->validity = CHANNEL_MAGIC | CHANNEL_SUPPORT;
266                 } else {
267                         pCh->validity = CHANNEL_MAGIC;
268                 }
269                 pCh->pMyBord = pB;      /* Back-pointer */
270
271                 // Prepare an outgoing flow-control packet to send as soon as the chance
272                 // occurs.
273                 if ( pCh->validity & CHANNEL_SUPPORT ) {
274                         pCh->infl.hd.i2sChannel = index;
275                         pCh->infl.hd.i2sCount = 5;
276                         pCh->infl.hd.i2sType = PTYPE_BYPASS;
277                         pCh->infl.fcmd = 37;
278                         pCh->infl.asof = 0;
279                         pCh->infl.room = IBUF_SIZE - 1;
280
281                         pCh->whenSendFlow = (IBUF_SIZE/5)*4; // when 80% full
282
283                 // The following is similar to calling i2QueueNeeds, except that this
284                 // is done in longhand, since we are setting up initial conditions on
285                 // many channels at once.
286                         pCh->channelNeeds = NEED_FLOW;  // Since starting from scratch
287                         pCh->sinceLastFlow = 0;         // No bytes received since last flow
288                                                                                         // control packet was queued
289                         stuffIndex++;
290                         *ppCh++ = pCh;      // List this channel as needing
291                                                                 // initial flow control packet sent
292                 }
293
294                 // Don't allow anything to be sent until the status packets come in from
295                 // the board.
296
297                 pCh->outfl.asof = 0;
298                 pCh->outfl.room = 0;
299
300                 // Initialize all the ring buffers
301
302                 pCh->Ibuf_stuff = pCh->Ibuf_strip = 0;
303                 pCh->Obuf_stuff = pCh->Obuf_strip = 0;
304                 pCh->Cbuf_stuff = pCh->Cbuf_strip = 0;
305
306                 memset( &pCh->icount, 0, sizeof (struct async_icount) );
307                 pCh->hotKeyIn       = HOT_CLEAR;
308                 pCh->channelOptions = 0;
309                 pCh->bookMarks      = 0;
310                 init_waitqueue_head(&pCh->pBookmarkWait);
311
312                 init_waitqueue_head(&pCh->open_wait);
313                 init_waitqueue_head(&pCh->close_wait);
314                 init_waitqueue_head(&pCh->delta_msr_wait);
315
316                 // Set base and divisor so default custom rate is 9600
317                 pCh->BaudBase    = 921600;      // MAX for ST654, changed after we get
318                 pCh->BaudDivisor = 96;          // the boxids (UART types) later
319
320                 pCh->dataSetIn   = 0;
321                 pCh->dataSetOut  = 0;
322
323                 pCh->wopen       = 0;
324                 pCh->throttled   = 0;
325
326                 pCh->speed       = CBR_9600;
327
328                 pCh->flags    = 0;
329
330                 pCh->ClosingDelay     = 5*HZ/10;
331                 pCh->ClosingWaitTime  = 30*HZ;
332
333                 // Initialize task queue objects
334                 INIT_WORK(&pCh->tqueue_input, do_input, pCh);
335                 INIT_WORK(&pCh->tqueue_status, do_status, pCh);
336
337 #ifdef IP2DEBUG_TRACE
338                 pCh->trace = ip2trace;
339 #endif
340
341                 ++pCh;
342         --nChannels;
343         }
344         // No need to check for wrap here; this is initialization.
345         pB->i2Fbuf_stuff = stuffIndex;
346         COMPLETE(pB, I2EE_GOOD);
347
348 }
349
350 //******************************************************************************
351 // Function:   i2DeQueueNeeds(pB, type)
352 // Parameters: Pointer to a board structure
353 //             type bit map: may include NEED_INLINE, NEED_BYPASS, or NEED_FLOW
354 // Returns:   
355 //             Pointer to a channel structure
356 //
357 // Description: Returns pointer struct of next channel that needs service of
358 //  the type specified. Otherwise returns a NULL reference.
359 //
360 //******************************************************************************
361 static i2ChanStrPtr 
362 i2DeQueueNeeds(i2eBordStrPtr pB, int type)
363 {
364         unsigned short queueIndex;
365         unsigned long flags;
366
367         i2ChanStrPtr pCh = NULL;
368
369         switch(type) {
370
371         case  NEED_INLINE:
372
373                 WRITE_LOCK_IRQSAVE(&pB->Dbuf_spinlock,flags);
374                 if ( pB->i2Dbuf_stuff != pB->i2Dbuf_strip)
375                 {
376                         queueIndex = pB->i2Dbuf_strip;
377                         pCh = pB->i2Dbuf[queueIndex];
378                         queueIndex++;
379                         if (queueIndex >= CH_QUEUE_SIZE) {
380                                 queueIndex = 0;
381                         }
382                         pB->i2Dbuf_strip = queueIndex;
383                         pCh->channelNeeds &= ~NEED_INLINE;
384                 }
385                 WRITE_UNLOCK_IRQRESTORE(&pB->Dbuf_spinlock,flags); 
386                 break;
387
388         case NEED_BYPASS:
389
390                 WRITE_LOCK_IRQSAVE(&pB->Bbuf_spinlock,flags);
391                 if (pB->i2Bbuf_stuff != pB->i2Bbuf_strip)
392                 {
393                         queueIndex = pB->i2Bbuf_strip;
394                         pCh = pB->i2Bbuf[queueIndex];
395                         queueIndex++;
396                         if (queueIndex >= CH_QUEUE_SIZE) {
397                                 queueIndex = 0;
398                         }
399                         pB->i2Bbuf_strip = queueIndex;
400                         pCh->channelNeeds &= ~NEED_BYPASS;
401                 }
402                 WRITE_UNLOCK_IRQRESTORE(&pB->Bbuf_spinlock,flags); 
403                 break;
404         
405         case NEED_FLOW:
406
407                 WRITE_LOCK_IRQSAVE(&pB->Fbuf_spinlock,flags);
408                 if (pB->i2Fbuf_stuff != pB->i2Fbuf_strip)
409                 {
410                         queueIndex = pB->i2Fbuf_strip;
411                         pCh = pB->i2Fbuf[queueIndex];
412                         queueIndex++;
413                         if (queueIndex >= CH_QUEUE_SIZE) {
414                                 queueIndex = 0;
415                         }
416                         pB->i2Fbuf_strip = queueIndex;
417                         pCh->channelNeeds &= ~NEED_FLOW;
418                 }
419                 WRITE_UNLOCK_IRQRESTORE(&pB->Fbuf_spinlock,flags); 
420                 break;
421         default:
422                 printk(KERN_ERR "i2DeQueueNeeds called with bad type:%x\n",type);
423                 break;
424         }
425         return pCh;
426 }
427
428 //******************************************************************************
429 // Function:   i2QueueNeeds(pB, pCh, type)
430 // Parameters: Pointer to a board structure
431 //             Pointer to a channel structure
432 //             type bit map: may include NEED_INLINE, NEED_BYPASS, or NEED_FLOW
433 // Returns:    Nothing
434 //
435 // Description:
436 // For each type of need selected, if the given channel is not already in the
437 // queue, adds it, and sets the flag indicating it is in the queue.
438 //******************************************************************************
439 static void
440 i2QueueNeeds(i2eBordStrPtr pB, i2ChanStrPtr pCh, int type)
441 {
442         unsigned short queueIndex;
443         unsigned long flags;
444
445         // We turn off all the interrupts during this brief process, since the
446         // interrupt-level code might want to put things on the queue as well.
447
448         switch (type) {
449
450         case NEED_INLINE:
451
452                 WRITE_LOCK_IRQSAVE(&pB->Dbuf_spinlock,flags);
453                 if ( !(pCh->channelNeeds & NEED_INLINE) )
454                 {
455                         pCh->channelNeeds |= NEED_INLINE;
456                         queueIndex = pB->i2Dbuf_stuff;
457                         pB->i2Dbuf[queueIndex++] = pCh;
458                         if (queueIndex >= CH_QUEUE_SIZE)
459                                 queueIndex = 0;
460                         pB->i2Dbuf_stuff = queueIndex;
461                 }
462                 WRITE_UNLOCK_IRQRESTORE(&pB->Dbuf_spinlock,flags); 
463                 break;
464
465         case NEED_BYPASS:
466
467                 WRITE_LOCK_IRQSAVE(&pB->Bbuf_spinlock,flags);
468                 if ((type & NEED_BYPASS) && !(pCh->channelNeeds & NEED_BYPASS))
469                 {
470                         pCh->channelNeeds |= NEED_BYPASS;
471                         queueIndex = pB->i2Bbuf_stuff;
472                         pB->i2Bbuf[queueIndex++] = pCh;
473                         if (queueIndex >= CH_QUEUE_SIZE)
474                                 queueIndex = 0;
475                         pB->i2Bbuf_stuff = queueIndex;
476                 } 
477                 WRITE_UNLOCK_IRQRESTORE(&pB->Bbuf_spinlock,flags); 
478                 break;
479
480         case NEED_FLOW:
481
482                 WRITE_LOCK_IRQSAVE(&pB->Fbuf_spinlock,flags);
483                 if ((type & NEED_FLOW) && !(pCh->channelNeeds & NEED_FLOW))
484                 {
485                         pCh->channelNeeds |= NEED_FLOW;
486                         queueIndex = pB->i2Fbuf_stuff;
487                         pB->i2Fbuf[queueIndex++] = pCh;
488                         if (queueIndex >= CH_QUEUE_SIZE)
489                                 queueIndex = 0;
490                         pB->i2Fbuf_stuff = queueIndex;
491                 }
492                 WRITE_UNLOCK_IRQRESTORE(&pB->Fbuf_spinlock,flags); 
493                 break;
494
495         case NEED_CREDIT:
496                 pCh->channelNeeds |= NEED_CREDIT;
497                 break;
498         default:
499                 printk(KERN_ERR "i2QueueNeeds called with bad type:%x\n",type);
500                 break;
501         }
502         return;
503 }
504
505 //******************************************************************************
506 // Function:   i2QueueCommands(type, pCh, timeout, nCommands, pCs,...)
507 // Parameters: type - PTYPE_BYPASS or PTYPE_INLINE
508 //             pointer to the channel structure
509 //             maximum period to wait
510 //             number of commands (n)
511 //             n commands
512 // Returns:    Number of commands sent, or -1 for error
513 //
514 // get board lock before calling
515 //
516 // Description:
517 // Queues up some commands to be sent to a channel. To send possibly several
518 // bypass or inline commands to the given channel. The timeout parameter
519 // indicates how many HUNDREDTHS OF SECONDS to wait until there is room:
520 // 0 = return immediately if no room, -ive  = wait forever, +ive = number of
521 // 1/100 seconds to wait. Return values:
522 // -1 Some kind of nasty error: bad channel structure or invalid arguments.
523 //  0 No room to send all the commands
524 // (+)   Number of commands sent
525 //******************************************************************************
526 static int
527 i2QueueCommands(int type, i2ChanStrPtr pCh, int timeout, int nCommands,
528                                          cmdSyntaxPtr pCs0,...)
529 {
530         int totalsize = 0;
531         int blocksize;
532         int lastended;
533         cmdSyntaxPtr *ppCs;
534         cmdSyntaxPtr pCs;
535         int count;
536         int flag;
537         i2eBordStrPtr pB;
538
539         unsigned short maxBlock;
540         unsigned short maxBuff;
541         short bufroom;
542         unsigned short stuffIndex;
543         unsigned char *pBuf;
544         unsigned char *pInsert;
545         unsigned char *pDest, *pSource;
546         unsigned short channel;
547         int cnt;
548         unsigned long flags = 0;
549         rwlock_t *lock_var_p = NULL;
550
551         // Make sure the channel exists, otherwise do nothing
552         if ( !i2Validate ( pCh ) ) {
553                 return -1;
554         }
555
556         ip2trace (CHANN, ITRC_QUEUE, ITRC_ENTER, 0 );
557
558         pB = pCh->pMyBord;
559
560         // Board must also exist, and THE INTERRUPT COMMAND ALREADY SENT
561         if (pB->i2eValid != I2E_MAGIC || pB->i2eUsingIrq == IRQ_UNDEFINED) {
562                 return -2;
563         }
564         // If the board has gone fatal, return bad, and also hit the trap routine if
565         // it exists.
566         if (pB->i2eFatal) {
567                 if ( pB->i2eFatalTrap ) {
568                         (*(pB)->i2eFatalTrap)(pB);
569                 }
570                 return -3;
571         }
572         // Set up some variables, Which buffers are we using?  How big are they?
573         switch(type)
574         {
575         case PTYPE_INLINE:
576                 flag = INL;
577                 maxBlock = MAX_OBUF_BLOCK;
578                 maxBuff = OBUF_SIZE;
579                 pBuf = pCh->Obuf;
580                 break;
581         case PTYPE_BYPASS:
582                 flag = BYP;
583                 maxBlock = MAX_CBUF_BLOCK;
584                 maxBuff = CBUF_SIZE;
585                 pBuf = pCh->Cbuf;
586                 break;
587         default:
588                 return -4;
589         }
590         // Determine the total size required for all the commands
591         totalsize = blocksize = sizeof(i2CmdHeader);
592         lastended = 0;
593         ppCs = &pCs0;
594         for ( count = nCommands; count; count--, ppCs++)
595         {
596                 pCs = *ppCs;
597                 cnt = pCs->length;
598                 // Will a new block be needed for this one? 
599                 // Two possible reasons: too
600                 // big or previous command has to be at the end of a packet.
601                 if ((blocksize + cnt > maxBlock) || lastended) {
602                         blocksize = sizeof(i2CmdHeader);
603                         totalsize += sizeof(i2CmdHeader);
604                 }
605                 totalsize += cnt;
606                 blocksize += cnt;
607
608                 // If this command had to end a block, then we will make sure to
609                 // account for it should there be any more blocks.
610                 lastended = pCs->flags & END;
611         }
612         for (;;) {
613                 // Make sure any pending flush commands go out before we add more data.
614                 if ( !( pCh->flush_flags && i2RetryFlushOutput( pCh ) ) ) {
615                         // How much room (this time through) ?
616                         switch(type) {
617                         case PTYPE_INLINE:
618                                 lock_var_p = &pCh->Obuf_spinlock;
619                                 WRITE_LOCK_IRQSAVE(lock_var_p,flags);
620                                 stuffIndex = pCh->Obuf_stuff;
621                                 bufroom = pCh->Obuf_strip - stuffIndex;
622                                 break;
623                         case PTYPE_BYPASS:
624                                 lock_var_p = &pCh->Cbuf_spinlock;
625                                 WRITE_LOCK_IRQSAVE(lock_var_p,flags);
626                                 stuffIndex = pCh->Cbuf_stuff;
627                                 bufroom = pCh->Cbuf_strip - stuffIndex;
628                                 break;
629                         default:
630                                 return -5;
631                         }
632                         if (--bufroom < 0) {
633                                 bufroom += maxBuff;
634                         }
635
636                         ip2trace (CHANN, ITRC_QUEUE, 2, 1, bufroom );
637
638                         // Check for overflow
639                         if (totalsize <= bufroom) {
640                                 // Normal Expected path - We still hold LOCK
641                                 break; /* from for()- Enough room: goto proceed */
642                         }
643                 }
644
645                 ip2trace (CHANN, ITRC_QUEUE, 3, 1, totalsize );
646
647                 // Prepare to wait for buffers to empty
648                 WRITE_UNLOCK_IRQRESTORE(lock_var_p,flags); 
649                 serviceOutgoingFifo(pB);        // Dump what we got
650
651                 if (timeout == 0) {
652                         return 0;   // Tired of waiting
653                 }
654                 if (timeout > 0)
655                         timeout--;   // So negative values == forever
656                 
657                 if (!in_interrupt()) {
658                         current->state = TASK_INTERRUPTIBLE;
659                         schedule_timeout(1);    // short nap 
660                 } else {
661                         // we cannot sched/sleep in interrrupt silly
662                         return 0;   
663                 }
664                 if (signal_pending(current)) {
665                         return 0;   // Wake up! Time to die!!!
666                 }
667
668                 ip2trace (CHANN, ITRC_QUEUE, 4, 0 );
669
670         }       // end of for(;;)
671
672         // At this point we have room and the lock - stick them in.
673         channel = pCh->infl.hd.i2sChannel;
674         pInsert = &pBuf[stuffIndex];     // Pointer to start of packet
675         pDest = CMD_OF(pInsert);         // Pointer to start of command
676
677         // When we start counting, the block is the size of the header
678         for (blocksize = sizeof(i2CmdHeader), count = nCommands,
679                         lastended = 0, ppCs = &pCs0;
680                 count;
681                 count--, ppCs++)
682         {
683                 pCs = *ppCs;         // Points to command protocol structure
684
685                 // If this is a bookmark request command, post the fact that a bookmark
686                 // request is pending. NOTE THIS TRICK ONLY WORKS BECAUSE CMD_BMARK_REQ
687                 // has no parameters!  The more general solution would be to reference
688                 // pCs->cmd[0].
689                 if (pCs == CMD_BMARK_REQ) {
690                         pCh->bookMarks++;
691
692                         ip2trace (CHANN, ITRC_DRAIN, 30, 1, pCh->bookMarks );
693
694                 }
695                 cnt = pCs->length;
696
697                 // If this command would put us over the maximum block size or 
698                 // if the last command had to be at the end of a block, we end
699                 // the existing block here and start a new one.
700                 if ((blocksize + cnt > maxBlock) || lastended) {
701
702                         ip2trace (CHANN, ITRC_QUEUE, 5, 0 );
703
704                         PTYPE_OF(pInsert) = type;
705                         CHANNEL_OF(pInsert) = channel;
706                         // count here does not include the header
707                         CMD_COUNT_OF(pInsert) = blocksize - sizeof(i2CmdHeader);
708                         stuffIndex += blocksize;
709                         if(stuffIndex >= maxBuff) {
710                                 stuffIndex = 0;
711                                 pInsert = pBuf;
712                         }
713                         pInsert = &pBuf[stuffIndex];  // Pointer to start of next pkt
714                         pDest = CMD_OF(pInsert);
715                         blocksize = sizeof(i2CmdHeader);
716                 }
717                 // Now we know there is room for this one in the current block
718
719                 blocksize += cnt;       // Total bytes in this command
720                 pSource = pCs->cmd;     // Copy the command into the buffer
721                 while (cnt--) {
722                         *pDest++ = *pSource++;
723                 }
724                 // If this command had to end a block, then we will make sure to account
725                 // for it should there be any more blocks.
726                 lastended = pCs->flags & END;
727         }       // end for
728         // Clean up the final block by writing header, etc
729
730         PTYPE_OF(pInsert) = type;
731         CHANNEL_OF(pInsert) = channel;
732         // count here does not include the header
733         CMD_COUNT_OF(pInsert) = blocksize - sizeof(i2CmdHeader);
734         stuffIndex += blocksize;
735         if(stuffIndex >= maxBuff) {
736                 stuffIndex = 0;
737                 pInsert = pBuf;
738         }
739         // Updates the index, and post the need for service. When adding these to
740         // the queue of channels, we turn off the interrupt while doing so,
741         // because at interrupt level we might want to push a channel back to the
742         // end of the queue.
743         switch(type)
744         {
745         case PTYPE_INLINE:
746                 pCh->Obuf_stuff = stuffIndex;  // Store buffer pointer
747                 WRITE_UNLOCK_IRQRESTORE(&pCh->Obuf_spinlock,flags); 
748
749                 pB->debugInlineQueued++;
750                 // Add the channel pointer to list of channels needing service (first
751                 // come...), if it's not already there.
752                 i2QueueNeeds(pB, pCh, NEED_INLINE);
753                 break;
754
755         case PTYPE_BYPASS:
756                 pCh->Cbuf_stuff = stuffIndex;  // Store buffer pointer
757                 WRITE_UNLOCK_IRQRESTORE(&pCh->Cbuf_spinlock,flags); 
758
759                 pB->debugBypassQueued++;
760                 // Add the channel pointer to list of channels needing service (first
761                 // come...), if it's not already there.
762                 i2QueueNeeds(pB, pCh, NEED_BYPASS);
763                 break;
764         }
765
766         ip2trace (CHANN, ITRC_QUEUE, ITRC_RETURN, 1, nCommands );
767
768         return nCommands; // Good status: number of commands sent
769 }
770
771 //******************************************************************************
772 // Function:   i2GetStatus(pCh,resetBits)
773 // Parameters: Pointer to a channel structure
774 //             Bit map of status bits to clear
775 // Returns:    Bit map of current status bits
776 //
777 // Description:
778 // Returns the state of data set signals, and whether a break has been received,
779 // (see i2lib.h for bit-mapped result). resetBits is a bit-map of any status
780 // bits to be cleared: I2_BRK, I2_PAR, I2_FRA, I2_OVR,... These are cleared
781 // AFTER the condition is passed. If pCh does not point to a valid channel,
782 // returns -1 (which would be impossible otherwise.
783 //******************************************************************************
784 static int
785 i2GetStatus(i2ChanStrPtr pCh, int resetBits)
786 {
787         unsigned short status;
788         i2eBordStrPtr pB;
789
790         ip2trace (CHANN, ITRC_STATUS, ITRC_ENTER, 2, pCh->dataSetIn, resetBits );
791
792         // Make sure the channel exists, otherwise do nothing */
793         if ( !i2Validate ( pCh ) )
794                 return -1;
795
796         pB = pCh->pMyBord;
797
798         status = pCh->dataSetIn;
799
800         // Clear any specified error bits: but note that only actual error bits can
801         // be cleared, regardless of the value passed.
802         if (resetBits)
803         {
804                 pCh->dataSetIn &= ~(resetBits & (I2_BRK | I2_PAR | I2_FRA | I2_OVR));
805                 pCh->dataSetIn &= ~(I2_DDCD | I2_DCTS | I2_DDSR | I2_DRI);
806         }
807
808         ip2trace (CHANN, ITRC_STATUS, ITRC_RETURN, 1, pCh->dataSetIn );
809
810         return status;
811 }
812
813 //******************************************************************************
814 // Function:   i2Input(pChpDest,count)
815 // Parameters: Pointer to a channel structure
816 //             Pointer to data buffer
817 //             Number of bytes to read
818 // Returns:    Number of bytes read, or -1 for error
819 //
820 // Description:
821 // Strips data from the input buffer and writes it to pDest. If there is a
822 // collosal blunder, (invalid structure pointers or the like), returns -1.
823 // Otherwise, returns the number of bytes read.
824 //******************************************************************************
825 static int
826 i2Input(i2ChanStrPtr pCh)
827 {
828         int amountToMove;
829         unsigned short stripIndex;
830         int count;
831         unsigned long flags = 0;
832
833         ip2trace (CHANN, ITRC_INPUT, ITRC_ENTER, 0);
834
835         // Ensure channel structure seems real
836         if ( !i2Validate( pCh ) ) {
837                 count = -1;
838                 goto i2Input_exit;
839         }
840         WRITE_LOCK_IRQSAVE(&pCh->Ibuf_spinlock,flags);
841
842         // initialize some accelerators and private copies
843         stripIndex = pCh->Ibuf_strip;
844
845         count = pCh->Ibuf_stuff - stripIndex;
846
847         // If buffer is empty or requested data count was 0, (trivial case) return
848         // without any further thought.
849         if ( count == 0 ) {
850                 WRITE_UNLOCK_IRQRESTORE(&pCh->Ibuf_spinlock,flags);
851                 goto i2Input_exit;
852         }
853         // Adjust for buffer wrap
854         if ( count < 0 ) {
855                 count += IBUF_SIZE;
856         }
857         // Don't give more than can be taken by the line discipline
858         amountToMove = pCh->pTTY->ldisc.receive_room( pCh->pTTY );
859         if (count > amountToMove) {
860                 count = amountToMove;
861         }
862         // How much could we copy without a wrap?
863         amountToMove = IBUF_SIZE - stripIndex;
864
865         if (amountToMove > count) {
866                 amountToMove = count;
867         }
868         // Move the first block
869         pCh->pTTY->ldisc.receive_buf( pCh->pTTY, 
870                  &(pCh->Ibuf[stripIndex]), NULL, amountToMove );
871         // If we needed to wrap, do the second data move
872         if (count > amountToMove) {
873                 pCh->pTTY->ldisc.receive_buf( pCh->pTTY, 
874                  pCh->Ibuf, NULL, count - amountToMove );
875         }
876         // Bump and wrap the stripIndex all at once by the amount of data read. This
877         // method is good regardless of whether the data was in one or two pieces.
878         stripIndex += count;
879         if (stripIndex >= IBUF_SIZE) {
880                 stripIndex -= IBUF_SIZE;
881         }
882         pCh->Ibuf_strip = stripIndex;
883
884         // Update our flow control information and possibly queue ourselves to send
885         // it, depending on how much data has been stripped since the last time a
886         // packet was sent.
887         pCh->infl.asof += count;
888
889         if ((pCh->sinceLastFlow += count) >= pCh->whenSendFlow) {
890                 pCh->sinceLastFlow -= pCh->whenSendFlow;
891                 WRITE_UNLOCK_IRQRESTORE(&pCh->Ibuf_spinlock,flags);
892                 i2QueueNeeds(pCh->pMyBord, pCh, NEED_FLOW);
893         } else {
894                 WRITE_UNLOCK_IRQRESTORE(&pCh->Ibuf_spinlock,flags);
895         }
896
897 i2Input_exit:
898
899         ip2trace (CHANN, ITRC_INPUT, ITRC_RETURN, 1, count);
900
901         return count;
902 }
903
904 //******************************************************************************
905 // Function:   i2InputFlush(pCh)
906 // Parameters: Pointer to a channel structure
907 // Returns:    Number of bytes stripped, or -1 for error
908 //
909 // Description:
910 // Strips any data from the input buffer. If there is a collosal blunder,
911 // (invalid structure pointers or the like), returns -1. Otherwise, returns the
912 // number of bytes stripped.
913 //******************************************************************************
914 static int
915 i2InputFlush(i2ChanStrPtr pCh)
916 {
917         int count;
918         unsigned long flags;
919
920         // Ensure channel structure seems real
921         if ( !i2Validate ( pCh ) )
922                 return -1;
923
924         ip2trace (CHANN, ITRC_INPUT, 10, 0);
925
926         WRITE_LOCK_IRQSAVE(&pCh->Ibuf_spinlock,flags);
927         count = pCh->Ibuf_stuff - pCh->Ibuf_strip;
928
929         // Adjust for buffer wrap
930         if (count < 0) {
931                 count += IBUF_SIZE;
932         }
933
934         // Expedient way to zero out the buffer
935         pCh->Ibuf_strip = pCh->Ibuf_stuff;
936
937
938         // Update our flow control information and possibly queue ourselves to send
939         // it, depending on how much data has been stripped since the last time a
940         // packet was sent.
941
942         pCh->infl.asof += count;
943
944         if ( (pCh->sinceLastFlow += count) >= pCh->whenSendFlow )
945         {
946                 pCh->sinceLastFlow -= pCh->whenSendFlow;
947                 WRITE_UNLOCK_IRQRESTORE(&pCh->Ibuf_spinlock,flags);
948                 i2QueueNeeds(pCh->pMyBord, pCh, NEED_FLOW);
949         } else {
950                 WRITE_UNLOCK_IRQRESTORE(&pCh->Ibuf_spinlock,flags);
951         }
952
953         ip2trace (CHANN, ITRC_INPUT, 19, 1, count);
954
955         return count;
956 }
957
958 //******************************************************************************
959 // Function:   i2InputAvailable(pCh)
960 // Parameters: Pointer to a channel structure
961 // Returns:    Number of bytes available, or -1 for error
962 //
963 // Description:
964 // If there is a collosal blunder, (invalid structure pointers or the like),
965 // returns -1. Otherwise, returns the number of bytes stripped. Otherwise,
966 // returns the number of bytes available in the buffer.
967 //******************************************************************************
968 #if 0
969 static int
970 i2InputAvailable(i2ChanStrPtr pCh)
971 {
972         int count;
973
974         // Ensure channel structure seems real
975         if ( !i2Validate ( pCh ) ) return -1;
976
977
978         // initialize some accelerators and private copies
979         READ_LOCK_IRQSAVE(&pCh->Ibuf_spinlock,flags);
980         count = pCh->Ibuf_stuff - pCh->Ibuf_strip;
981         READ_UNLOCK_IRQRESTORE(&pCh->Ibuf_spinlock,flags);
982
983         // Adjust for buffer wrap
984         if (count < 0)
985         {
986                 count += IBUF_SIZE;
987         }
988
989         return count;
990 }
991 #endif 
992
993 //******************************************************************************
994 // Function:   i2Output(pCh, pSource, count)
995 // Parameters: Pointer to channel structure
996 //             Pointer to source data
997 //             Number of bytes to send
998 // Returns:    Number of bytes sent, or -1 for error
999 //
1000 // Description:
1001 // Queues the data at pSource to be sent as data packets to the board. If there
1002 // is a collosal blunder, (invalid structure pointers or the like), returns -1.
1003 // Otherwise, returns the number of bytes written. What if there is not enough
1004 // room for all the data? If pCh->channelOptions & CO_NBLOCK_WRITE is set, then
1005 // we transfer as many characters as we can now, then return. If this bit is
1006 // clear (default), routine will spin along until all the data is buffered.
1007 // Should this occur, the 1-ms delay routine is called while waiting to avoid
1008 // applications that one cannot break out of.
1009 //******************************************************************************
1010 static int
1011 i2Output(i2ChanStrPtr pCh, const char *pSource, int count, int user )
1012 {
1013         i2eBordStrPtr pB;
1014         unsigned char *pInsert;
1015         int amountToMove;
1016         int countOriginal = count;
1017         unsigned short channel;
1018         unsigned short stuffIndex;
1019         unsigned long flags;
1020         int rc = 0;
1021
1022         int bailout = 10;
1023
1024         ip2trace (CHANN, ITRC_OUTPUT, ITRC_ENTER, 2, count, user );
1025
1026         // Ensure channel structure seems real
1027         if ( !i2Validate ( pCh ) ) 
1028                 return -1;
1029
1030         // initialize some accelerators and private copies
1031         pB = pCh->pMyBord;
1032         channel = pCh->infl.hd.i2sChannel;
1033
1034         // If the board has gone fatal, return bad, and also hit the trap routine if
1035         // it exists.
1036         if (pB->i2eFatal) {
1037                 if (pB->i2eFatalTrap) {
1038                         (*(pB)->i2eFatalTrap)(pB);
1039                 }
1040                 return -1;
1041         }
1042         // Proceed as though we would do everything
1043         while ( count > 0 ) {
1044
1045                 // How much room in output buffer is there?
1046                 READ_LOCK_IRQSAVE(&pCh->Obuf_spinlock,flags);
1047                 amountToMove = pCh->Obuf_strip - pCh->Obuf_stuff - 1;
1048                 READ_UNLOCK_IRQRESTORE(&pCh->Obuf_spinlock,flags);
1049                 if (amountToMove < 0) {
1050                         amountToMove += OBUF_SIZE;
1051                 }
1052                 // Subtract off the headers size and see how much room there is for real
1053                 // data. If this is negative, we will discover later.
1054                 amountToMove -= sizeof (i2DataHeader);
1055
1056                 // Don't move more (now) than can go in a single packet
1057                 if ( amountToMove > (int)(MAX_OBUF_BLOCK - sizeof(i2DataHeader)) ) {
1058                         amountToMove = MAX_OBUF_BLOCK - sizeof(i2DataHeader);
1059                 }
1060                 // Don't move more than the count we were given
1061                 if (amountToMove > count) {
1062                         amountToMove = count;
1063                 }
1064                 // Now we know how much we must move: NB because the ring buffers have
1065                 // an overflow area at the end, we needn't worry about wrapping in the
1066                 // middle of a packet.
1067
1068 // Small WINDOW here with no LOCK but I can't call Flush with LOCK
1069 // We would be flushing (or ending flush) anyway
1070
1071                 ip2trace (CHANN, ITRC_OUTPUT, 10, 1, amountToMove );
1072
1073                 if ( !(pCh->flush_flags && i2RetryFlushOutput(pCh) ) 
1074                                 && amountToMove > 0 )
1075                 {
1076                         WRITE_LOCK_IRQSAVE(&pCh->Obuf_spinlock,flags);
1077                         stuffIndex = pCh->Obuf_stuff;
1078       
1079                         // Had room to move some data: don't know whether the block size,
1080                         // buffer space, or what was the limiting factor...
1081                         pInsert = &(pCh->Obuf[stuffIndex]);
1082
1083                         // Set up the header
1084                         CHANNEL_OF(pInsert)     = channel;
1085                         PTYPE_OF(pInsert)       = PTYPE_DATA;
1086                         TAG_OF(pInsert)         = 0;
1087                         ID_OF(pInsert)          = ID_ORDINARY_DATA;
1088                         DATA_COUNT_OF(pInsert)  = amountToMove;
1089
1090                         // Move the data
1091                         if ( user ) {
1092                                 rc = copy_from_user((char*)(DATA_OF(pInsert)), pSource,
1093                                                 amountToMove );
1094                         } else {
1095                                 memcpy( (char*)(DATA_OF(pInsert)), pSource, amountToMove );
1096                         }
1097                         // Adjust pointers and indices
1098                         pSource                                 += amountToMove;
1099                         pCh->Obuf_char_count    += amountToMove;
1100                         stuffIndex                              += amountToMove + sizeof(i2DataHeader);
1101                         count                                   -= amountToMove;
1102
1103                         if (stuffIndex >= OBUF_SIZE) {
1104                                 stuffIndex = 0;
1105                         }
1106                         pCh->Obuf_stuff = stuffIndex;
1107
1108                         WRITE_UNLOCK_IRQRESTORE(&pCh->Obuf_spinlock,flags);
1109
1110                         ip2trace (CHANN, ITRC_OUTPUT, 13, 1, stuffIndex );
1111
1112                 } else {
1113
1114                         // Cannot move data
1115                         // becuz we need to stuff a flush 
1116                         // or amount to move is <= 0
1117
1118                         ip2trace(CHANN, ITRC_OUTPUT, 14, 3,
1119                                 amountToMove,  pB->i2eFifoRemains,
1120                                 pB->i2eWaitingForEmptyFifo );
1121
1122                         // Put this channel back on queue
1123                         // this ultimatly gets more data or wakes write output
1124                         i2QueueNeeds(pB, pCh, NEED_INLINE);
1125
1126                         if ( pB->i2eWaitingForEmptyFifo ) {
1127
1128                                 ip2trace (CHANN, ITRC_OUTPUT, 16, 0 );
1129
1130                                 // or schedule
1131                                 if (!in_interrupt()) {
1132
1133                                         ip2trace (CHANN, ITRC_OUTPUT, 61, 0 );
1134
1135                                         current->state = TASK_INTERRUPTIBLE;
1136                                         schedule_timeout(2);
1137                                         if (signal_pending(current)) {
1138                                                 break;
1139                                         }
1140                                         continue;
1141                                 } else {
1142
1143                                         ip2trace (CHANN, ITRC_OUTPUT, 62, 0 );
1144
1145                                         // let interrupt in = WAS restore_flags()
1146                                         // We hold no lock nor is irq off anymore???
1147                                         
1148                                         break;
1149                                 }
1150                                 break;   // from while(count)
1151                         }
1152                         else if ( pB->i2eFifoRemains < 32 && !pB->i2eTxMailEmpty ( pB ) )
1153                         {
1154                                 ip2trace (CHANN, ITRC_OUTPUT, 19, 2,
1155                                         pB->i2eFifoRemains,
1156                                         pB->i2eTxMailEmpty );
1157
1158                                 break;   // from while(count)
1159                         } else if ( pCh->channelNeeds & NEED_CREDIT ) {
1160
1161                                 ip2trace (CHANN, ITRC_OUTPUT, 22, 0 );
1162
1163                                 break;   // from while(count)
1164                         } else if ( --bailout) {
1165
1166                                 // Try to throw more things (maybe not us) in the fifo if we're
1167                                 // not already waiting for it.
1168         
1169                                 ip2trace (CHANN, ITRC_OUTPUT, 20, 0 );
1170
1171                                 serviceOutgoingFifo(pB);
1172                                 //break;  CONTINUE;
1173                         } else {
1174                                 ip2trace (CHANN, ITRC_OUTPUT, 21, 3,
1175                                         pB->i2eFifoRemains,
1176                                         pB->i2eOutMailWaiting,
1177                                         pB->i2eWaitingForEmptyFifo );
1178
1179                                 break;   // from while(count)
1180                         }
1181                 }
1182         } // End of while(count)
1183
1184         i2QueueNeeds(pB, pCh, NEED_INLINE);
1185
1186         // We drop through either when the count expires, or when there is some
1187         // count left, but there was a non-blocking write.
1188         if (countOriginal > count) {
1189
1190                 ip2trace (CHANN, ITRC_OUTPUT, 17, 2, countOriginal, count );
1191
1192                 serviceOutgoingFifo( pB );
1193         }
1194
1195         ip2trace (CHANN, ITRC_OUTPUT, ITRC_RETURN, 2, countOriginal, count );
1196
1197         return countOriginal - count;
1198 }
1199
1200 //******************************************************************************
1201 // Function:   i2FlushOutput(pCh)
1202 // Parameters: Pointer to a channel structure
1203 // Returns:    Nothing
1204 //
1205 // Description:
1206 // Sends bypass command to start flushing (waiting possibly forever until there
1207 // is room), then sends inline command to stop flushing output, (again waiting
1208 // possibly forever).
1209 //******************************************************************************
1210 static inline void
1211 i2FlushOutput(i2ChanStrPtr pCh)
1212 {
1213
1214         ip2trace (CHANN, ITRC_FLUSH, 1, 1, pCh->flush_flags );
1215
1216         if (pCh->flush_flags)
1217                 return;
1218
1219         if ( 1 != i2QueueCommands(PTYPE_BYPASS, pCh, 0, 1, CMD_STARTFL) ) {
1220                 pCh->flush_flags = STARTFL_FLAG;                // Failed - flag for later
1221
1222                 ip2trace (CHANN, ITRC_FLUSH, 2, 0 );
1223
1224         } else if ( 1 != i2QueueCommands(PTYPE_INLINE, pCh, 0, 1, CMD_STOPFL) ) {
1225                 pCh->flush_flags = STOPFL_FLAG;         // Failed - flag for later
1226
1227                 ip2trace (CHANN, ITRC_FLUSH, 3, 0 );
1228         }
1229 }
1230
1231 static int 
1232 i2RetryFlushOutput(i2ChanStrPtr pCh)
1233 {
1234         int old_flags = pCh->flush_flags;
1235
1236         ip2trace (CHANN, ITRC_FLUSH, 14, 1, old_flags );
1237
1238         pCh->flush_flags = 0;   // Clear flag so we can avoid recursion
1239                                                                         // and queue the commands
1240
1241         if ( old_flags & STARTFL_FLAG ) {
1242                 if ( 1 == i2QueueCommands(PTYPE_BYPASS, pCh, 0, 1, CMD_STARTFL) ) {
1243                         old_flags = STOPFL_FLAG;        //Success - send stop flush
1244                 } else {
1245                         old_flags = STARTFL_FLAG;       //Failure - Flag for retry later
1246                 }
1247
1248                 ip2trace (CHANN, ITRC_FLUSH, 15, 1, old_flags );
1249
1250         }
1251         if ( old_flags & STOPFL_FLAG ) {
1252                 if (1 == i2QueueCommands(PTYPE_INLINE, pCh, 0, 1, CMD_STOPFL)) {
1253                         old_flags = 0;  // Success - clear flags
1254                 }
1255
1256                 ip2trace (CHANN, ITRC_FLUSH, 16, 1, old_flags );
1257         }
1258         pCh->flush_flags = old_flags;
1259
1260         ip2trace (CHANN, ITRC_FLUSH, 17, 1, old_flags );
1261
1262         return old_flags;
1263 }
1264
1265 //******************************************************************************
1266 // Function:   i2DrainOutput(pCh,timeout)
1267 // Parameters: Pointer to a channel structure
1268 //             Maximum period to wait
1269 // Returns:    ?
1270 //
1271 // Description:
1272 // Uses the bookmark request command to ask the board to send a bookmark back as
1273 // soon as all the data is completely sent.
1274 //******************************************************************************
1275 static void
1276 i2DrainWakeup(i2ChanStrPtr pCh)
1277 {
1278         ip2trace (CHANN, ITRC_DRAIN, 10, 1, pCh->BookmarkTimer.expires );
1279
1280         pCh->BookmarkTimer.expires = 0;
1281         wake_up_interruptible( &pCh->pBookmarkWait );
1282 }
1283
1284 static void
1285 i2DrainOutput(i2ChanStrPtr pCh, int timeout)
1286 {
1287         wait_queue_t wait;
1288         i2eBordStrPtr pB;
1289
1290         ip2trace (CHANN, ITRC_DRAIN, ITRC_ENTER, 1, pCh->BookmarkTimer.expires);
1291
1292         pB = pCh->pMyBord;
1293         // If the board has gone fatal, return bad, 
1294         // and also hit the trap routine if it exists.
1295         if (pB->i2eFatal) {
1296                 if (pB->i2eFatalTrap) {
1297                         (*(pB)->i2eFatalTrap)(pB);
1298                 }
1299                 return;
1300         }
1301         if ((timeout > 0) && (pCh->BookmarkTimer.expires == 0 )) {
1302                 // One per customer (channel)
1303                 init_timer( &(pCh->BookmarkTimer) );
1304                 pCh->BookmarkTimer.expires  = jiffies + timeout;
1305                 pCh->BookmarkTimer.function = (void*)(unsigned long)i2DrainWakeup;
1306                 pCh->BookmarkTimer.data     = (unsigned long)pCh;
1307
1308                 ip2trace (CHANN, ITRC_DRAIN, 1, 1, pCh->BookmarkTimer.expires );
1309
1310                 add_timer( &(pCh->BookmarkTimer) );
1311         }
1312         
1313         i2QueueCommands( PTYPE_INLINE, pCh, -1, 1, CMD_BMARK_REQ );
1314
1315         init_waitqueue_entry(&wait, current);
1316         add_wait_queue(&(pCh->pBookmarkWait), &wait);
1317         set_current_state( TASK_INTERRUPTIBLE );
1318
1319         serviceOutgoingFifo( pB );
1320         
1321         schedule();     // Now we take our interruptible sleep on
1322
1323         // Clean up the queue
1324         set_current_state( TASK_RUNNING );
1325         remove_wait_queue(&(pCh->pBookmarkWait), &wait);
1326
1327         // if expires == 0 then timer poped, then do not need to del_timer
1328         if ((timeout > 0) && pCh->BookmarkTimer.expires && 
1329                              time_before(jiffies, pCh->BookmarkTimer.expires)) {
1330                 del_timer( &(pCh->BookmarkTimer) );
1331                 pCh->BookmarkTimer.expires = 0;
1332
1333                 ip2trace (CHANN, ITRC_DRAIN, 3, 1, pCh->BookmarkTimer.expires );
1334
1335         }
1336         ip2trace (CHANN, ITRC_DRAIN, ITRC_RETURN, 1, pCh->BookmarkTimer.expires );
1337         return;
1338 }
1339
1340 //******************************************************************************
1341 // Function:   i2OutputFree(pCh)
1342 // Parameters: Pointer to a channel structure
1343 // Returns:    Space in output buffer
1344 //
1345 // Description:
1346 // Returns -1 if very gross error. Otherwise returns the amount of bytes still
1347 // free in the output buffer.
1348 //******************************************************************************
1349 static int
1350 i2OutputFree(i2ChanStrPtr pCh)
1351 {
1352         int amountToMove;
1353         unsigned long flags;
1354
1355         // Ensure channel structure seems real
1356         if ( !i2Validate ( pCh ) ) {
1357                 return -1;
1358         }
1359         READ_LOCK_IRQSAVE(&pCh->Obuf_spinlock,flags);
1360         amountToMove = pCh->Obuf_strip - pCh->Obuf_stuff - 1;
1361         READ_UNLOCK_IRQRESTORE(&pCh->Obuf_spinlock,flags);
1362
1363         if (amountToMove < 0) {
1364                 amountToMove += OBUF_SIZE;
1365         }
1366         // If this is negative, we will discover later
1367         amountToMove -= sizeof(i2DataHeader);
1368
1369         return (amountToMove < 0) ? 0 : amountToMove;
1370 }
1371 static void
1372
1373 ip2_owake( PTTY tp)
1374 {
1375         i2ChanStrPtr  pCh;
1376
1377         if (tp == NULL) return;
1378
1379         pCh = tp->driver_data;
1380
1381         ip2trace (CHANN, ITRC_SICMD, 10, 2, tp->flags,
1382                         (1 << TTY_DO_WRITE_WAKEUP) );
1383
1384         wake_up_interruptible ( &tp->write_wait );
1385         if ( ( tp->flags & (1 << TTY_DO_WRITE_WAKEUP) ) 
1386           && tp->ldisc.write_wakeup )
1387         {
1388                 (tp->ldisc.write_wakeup) ( tp );
1389
1390                 ip2trace (CHANN, ITRC_SICMD, 11, 0 );
1391
1392         }
1393 }
1394
1395 static inline void
1396 set_baud_params(i2eBordStrPtr pB) 
1397 {
1398         int i,j;
1399         i2ChanStrPtr  *pCh;
1400
1401         pCh = (i2ChanStrPtr *) pB->i2eChannelPtr;
1402
1403         for (i = 0; i < ABS_MAX_BOXES; i++) {
1404                 if (pB->channelBtypes.bid_value[i]) {
1405                         if (BID_HAS_654(pB->channelBtypes.bid_value[i])) {
1406                                 for (j = 0; j < ABS_BIGGEST_BOX; j++) {
1407                                         if (pCh[i*16+j] == NULL)
1408                                                 break;
1409                                         (pCh[i*16+j])->BaudBase    = 921600;    // MAX for ST654
1410                                         (pCh[i*16+j])->BaudDivisor = 96;
1411                                 }
1412                         } else {        // has cirrus cd1400
1413                                 for (j = 0; j < ABS_BIGGEST_BOX; j++) {
1414                                         if (pCh[i*16+j] == NULL)
1415                                                 break;
1416                                         (pCh[i*16+j])->BaudBase    = 115200;    // MAX for CD1400
1417                                         (pCh[i*16+j])->BaudDivisor = 12;
1418                                 }
1419                         }
1420                 }
1421         }
1422 }
1423
1424 //******************************************************************************
1425 // Function:   i2StripFifo(pB)
1426 // Parameters: Pointer to a board structure
1427 // Returns:    ?
1428 //
1429 // Description:
1430 // Strips all the available data from the incoming FIFO, identifies the type of
1431 // packet, and either buffers the data or does what needs to be done.
1432 //
1433 // Note there is no overflow checking here: if the board sends more data than it
1434 // ought to, we will not detect it here, but blindly overflow...
1435 //******************************************************************************
1436
1437 // A buffer for reading in blocks for unknown channels
1438 static unsigned char junkBuffer[IBUF_SIZE];
1439
1440 // A buffer to read in a status packet. Because of the size of the count field
1441 // for these things, the maximum packet size must be less than MAX_CMD_PACK_SIZE
1442 static unsigned char cmdBuffer[MAX_CMD_PACK_SIZE + 4];
1443
1444 // This table changes the bit order from MSR order given by STAT_MODEM packet to
1445 // status bits used in our library.
1446 static char xlatDss[16] = {
1447 0      | 0     | 0      | 0      ,
1448 0      | 0     | 0      | I2_CTS ,
1449 0      | 0     | I2_DSR | 0      ,
1450 0      | 0     | I2_DSR | I2_CTS ,
1451 0      | I2_RI | 0      | 0      ,
1452 0      | I2_RI | 0      | I2_CTS ,
1453 0      | I2_RI | I2_DSR | 0      ,
1454 0      | I2_RI | I2_DSR | I2_CTS ,
1455 I2_DCD | 0     | 0      | 0      ,
1456 I2_DCD | 0     | 0      | I2_CTS ,
1457 I2_DCD | 0     | I2_DSR | 0      ,
1458 I2_DCD | 0     | I2_DSR | I2_CTS ,
1459 I2_DCD | I2_RI | 0      | 0      ,
1460 I2_DCD | I2_RI | 0      | I2_CTS ,
1461 I2_DCD | I2_RI | I2_DSR | 0      ,
1462 I2_DCD | I2_RI | I2_DSR | I2_CTS };
1463
1464 static inline void
1465 i2StripFifo(i2eBordStrPtr pB)
1466 {
1467         i2ChanStrPtr pCh;
1468         int channel;
1469         int count;
1470         unsigned short stuffIndex;
1471         int amountToRead;
1472         unsigned char *pc, *pcLimit;
1473         unsigned char uc;
1474         unsigned char dss_change;
1475         unsigned long bflags,cflags;
1476
1477 //      ip2trace (ITRC_NO_PORT, ITRC_SFIFO, ITRC_ENTER, 0 );
1478
1479         while (HAS_INPUT(pB)) {
1480 //              ip2trace (ITRC_NO_PORT, ITRC_SFIFO, 2, 0 );
1481
1482                 // Process packet from fifo a one atomic unit
1483                 WRITE_LOCK_IRQSAVE(&pB->read_fifo_spinlock,bflags);
1484    
1485                 // The first word (or two bytes) will have channel number and type of
1486                 // packet, possibly other information
1487                 pB->i2eLeadoffWord[0] = iiReadWord(pB);
1488
1489                 switch(PTYPE_OF(pB->i2eLeadoffWord))
1490                 {
1491                 case PTYPE_DATA:
1492                         pB->got_input = 1;
1493
1494 //                      ip2trace (ITRC_NO_PORT, ITRC_SFIFO, 3, 0 );
1495
1496                         channel = CHANNEL_OF(pB->i2eLeadoffWord); /* Store channel */
1497                         count = iiReadWord(pB);          /* Count is in the next word */
1498
1499 // NEW: Check the count for sanity! Should the hardware fail, our death
1500 // is more pleasant. While an oversize channel is acceptable (just more
1501 // than the driver supports), an over-length count clearly means we are
1502 // sick!
1503                         if ( ((unsigned int)count) > IBUF_SIZE ) {
1504                                 pB->i2eFatal = 2;
1505                                 WRITE_UNLOCK_IRQRESTORE(&pB->read_fifo_spinlock,bflags);
1506                                 return;     /* Bail out ASAP */
1507                         }
1508                         // Channel is illegally big ?
1509                         if ((channel >= pB->i2eChannelCnt) ||
1510                                 (NULL==(pCh = ((i2ChanStrPtr*)pB->i2eChannelPtr)[channel])))
1511                         {
1512                                 iiReadBuf(pB, junkBuffer, count);
1513                                 WRITE_UNLOCK_IRQRESTORE(&pB->read_fifo_spinlock,bflags);
1514                                 break;         /* From switch: ready for next packet */
1515                         }
1516
1517                         // Channel should be valid, then
1518
1519                         // If this is a hot-key, merely post its receipt for now. These are
1520                         // always supposed to be 1-byte packets, so we won't even check the
1521                         // count. Also we will post an acknowledgement to the board so that
1522                         // more data can be forthcoming. Note that we are not trying to use
1523                         // these sequences in this driver, merely to robustly ignore them.
1524                         if(ID_OF(pB->i2eLeadoffWord) == ID_HOT_KEY)
1525                         {
1526                                 pCh->hotKeyIn = iiReadWord(pB) & 0xff;
1527                                 WRITE_UNLOCK_IRQRESTORE(&pB->read_fifo_spinlock,bflags);
1528                                 i2QueueCommands(PTYPE_BYPASS, pCh, 0, 1, CMD_HOTACK);
1529                                 break;   /* From the switch: ready for next packet */
1530                         }
1531
1532                         // Normal data! We crudely assume there is room for the data in our
1533                         // buffer because the board wouldn't have exceeded his credit limit.
1534                         WRITE_LOCK_IRQSAVE(&pCh->Ibuf_spinlock,cflags);
1535                                                                                                         // We have 2 locks now
1536                         stuffIndex = pCh->Ibuf_stuff;
1537                         amountToRead = IBUF_SIZE - stuffIndex;
1538                         if (amountToRead > count)
1539                                 amountToRead = count;
1540
1541                         // stuffIndex would have been already adjusted so there would 
1542                         // always be room for at least one, and count is always at least
1543                         // one.
1544
1545                         iiReadBuf(pB, &(pCh->Ibuf[stuffIndex]), amountToRead);
1546                         pCh->icount.rx += amountToRead;
1547
1548                         // Update the stuffIndex by the amount of data moved. Note we could
1549                         // never ask for more data than would just fit. However, we might
1550                         // have read in one more byte than we wanted because the read
1551                         // rounds up to even bytes. If this byte is on the end of the
1552                         // packet, and is padding, we ignore it. If the byte is part of
1553                         // the actual data, we need to move it.
1554
1555                         stuffIndex += amountToRead;
1556
1557                         if (stuffIndex >= IBUF_SIZE) {
1558                                 if ((amountToRead & 1) && (count > amountToRead)) {
1559                                         pCh->Ibuf[0] = pCh->Ibuf[IBUF_SIZE];
1560                                         amountToRead++;
1561                                         stuffIndex = 1;
1562                                 } else {
1563                                         stuffIndex = 0;
1564                                 }
1565                         }
1566
1567                         // If there is anything left over, read it as well
1568                         if (count > amountToRead) {
1569                                 amountToRead = count - amountToRead;
1570                                 iiReadBuf(pB, &(pCh->Ibuf[stuffIndex]), amountToRead);
1571                                 pCh->icount.rx += amountToRead;
1572                                 stuffIndex += amountToRead;
1573                         }
1574
1575                         // Update stuff index
1576                         pCh->Ibuf_stuff = stuffIndex;
1577                         WRITE_UNLOCK_IRQRESTORE(&pCh->Ibuf_spinlock,cflags);
1578                         WRITE_UNLOCK_IRQRESTORE(&pB->read_fifo_spinlock,bflags);
1579
1580 #ifdef USE_IQ
1581                         schedule_work(&pCh->tqueue_input);
1582 #else
1583                         do_input(pCh);
1584 #endif
1585
1586                         // Note we do not need to maintain any flow-control credits at this
1587                         // time:  if we were to increment .asof and decrement .room, there
1588                         // would be no net effect. Instead, when we strip data, we will
1589                         // increment .asof and leave .room unchanged.
1590
1591                         break;   // From switch: ready for next packet
1592
1593                 case PTYPE_STATUS:
1594                         ip2trace (ITRC_NO_PORT, ITRC_SFIFO, 4, 0 );
1595       
1596                         count = CMD_COUNT_OF(pB->i2eLeadoffWord);
1597
1598                         iiReadBuf(pB, cmdBuffer, count);
1599                         // We can release early with buffer grab
1600                         WRITE_UNLOCK_IRQRESTORE(&pB->read_fifo_spinlock,bflags);
1601
1602                         pc = cmdBuffer;
1603                         pcLimit = &(cmdBuffer[count]);
1604
1605                         while (pc < pcLimit) {
1606                                 channel = *pc++;
1607
1608                                 ip2trace (channel, ITRC_SFIFO, 7, 2, channel, *pc );
1609
1610                                 /* check for valid channel */
1611                                 if (channel < pB->i2eChannelCnt
1612                                          && 
1613                                          (pCh = (((i2ChanStrPtr*)pB->i2eChannelPtr)[channel])) != NULL
1614                                         )
1615                                 {
1616                                         dss_change = 0;
1617
1618                                         switch (uc = *pc++)
1619                                         {
1620                                         /* Breaks and modem signals are easy: just update status */
1621                                         case STAT_CTS_UP:
1622                                                 if ( !(pCh->dataSetIn & I2_CTS) )
1623                                                 {
1624                                                         pCh->dataSetIn |= I2_DCTS;
1625                                                         pCh->icount.cts++;
1626                                                         dss_change = 1;
1627                                                 }
1628                                                 pCh->dataSetIn |= I2_CTS;
1629                                                 break;
1630
1631                                         case STAT_CTS_DN:
1632                                                 if ( pCh->dataSetIn & I2_CTS )
1633                                                 {
1634                                                         pCh->dataSetIn |= I2_DCTS;
1635                                                         pCh->icount.cts++;
1636                                                         dss_change = 1;
1637                                                 }
1638                                                 pCh->dataSetIn &= ~I2_CTS;
1639                                                 break;
1640
1641                                         case STAT_DCD_UP:
1642                                                 ip2trace (channel, ITRC_MODEM, 1, 1, pCh->dataSetIn );
1643
1644                                                 if ( !(pCh->dataSetIn & I2_DCD) )
1645                                                 {
1646                                                         ip2trace (CHANN, ITRC_MODEM, 2, 0 );
1647                                                         pCh->dataSetIn |= I2_DDCD;
1648                                                         pCh->icount.dcd++;
1649                                                         dss_change = 1;
1650                                                 }
1651                                                 pCh->dataSetIn |= I2_DCD;
1652
1653                                                 ip2trace (channel, ITRC_MODEM, 3, 1, pCh->dataSetIn );
1654                                                 break;
1655
1656                                         case STAT_DCD_DN:
1657                                                 ip2trace (channel, ITRC_MODEM, 4, 1, pCh->dataSetIn );
1658                                                 if ( pCh->dataSetIn & I2_DCD )
1659                                                 {
1660                                                         ip2trace (channel, ITRC_MODEM, 5, 0 );
1661                                                         pCh->dataSetIn |= I2_DDCD;
1662                                                         pCh->icount.dcd++;
1663                                                         dss_change = 1;
1664                                                 }
1665                                                 pCh->dataSetIn &= ~I2_DCD;
1666
1667                                                 ip2trace (channel, ITRC_MODEM, 6, 1, pCh->dataSetIn );
1668                                                 break;
1669
1670                                         case STAT_DSR_UP:
1671                                                 if ( !(pCh->dataSetIn & I2_DSR) )
1672                                                 {
1673                                                         pCh->dataSetIn |= I2_DDSR;
1674                                                         pCh->icount.dsr++;
1675                                                         dss_change = 1;
1676                                                 }
1677                                                 pCh->dataSetIn |= I2_DSR;
1678                                                 break;
1679
1680                                         case STAT_DSR_DN:
1681                                                 if ( pCh->dataSetIn & I2_DSR )
1682                                                 {
1683                                                         pCh->dataSetIn |= I2_DDSR;
1684                                                         pCh->icount.dsr++;
1685                                                         dss_change = 1;
1686                                                 }
1687                                                 pCh->dataSetIn &= ~I2_DSR;
1688                                                 break;
1689
1690                                         case STAT_RI_UP:
1691                                                 if ( !(pCh->dataSetIn & I2_RI) )
1692                                                 {
1693                                                         pCh->dataSetIn |= I2_DRI;
1694                                                         pCh->icount.rng++;
1695                                                         dss_change = 1;
1696                                                 }
1697                                                 pCh->dataSetIn |= I2_RI ;
1698                                                 break;
1699
1700                                         case STAT_RI_DN:
1701                                                 // to be compat with serial.c
1702                                                 //if ( pCh->dataSetIn & I2_RI )
1703                                                 //{
1704                                                 //      pCh->dataSetIn |= I2_DRI;
1705                                                 //      pCh->icount.rng++; 
1706                                                 //      dss_change = 1;
1707                                                 //}
1708                                                 pCh->dataSetIn &= ~I2_RI ;
1709                                                 break;
1710
1711                                         case STAT_BRK_DET:
1712                                                 pCh->dataSetIn |= I2_BRK;
1713                                                 pCh->icount.brk++;
1714                                                 dss_change = 1;
1715                                                 break;
1716
1717                                         // Bookmarks? one less request we're waiting for
1718                                         case STAT_BMARK:
1719                                                 pCh->bookMarks--;
1720                                                 if (pCh->bookMarks <= 0 ) {
1721                                                         pCh->bookMarks = 0;
1722                                                         wake_up_interruptible( &pCh->pBookmarkWait );
1723
1724                                                 ip2trace (channel, ITRC_DRAIN, 20, 1, pCh->BookmarkTimer.expires );
1725                                                 }
1726                                                 break;
1727
1728                                         // Flow control packets? Update the new credits, and if
1729                                         // someone was waiting for output, queue him up again.
1730                                         case STAT_FLOW:
1731                                                 pCh->outfl.room =
1732                                                         ((flowStatPtr)pc)->room -
1733                                                         (pCh->outfl.asof - ((flowStatPtr)pc)->asof);
1734
1735                                                 ip2trace (channel, ITRC_STFLW, 1, 1, pCh->outfl.room );
1736
1737                                                 if (pCh->channelNeeds & NEED_CREDIT)
1738                                                 {
1739                                                         ip2trace (channel, ITRC_STFLW, 2, 1, pCh->channelNeeds);
1740
1741                                                         pCh->channelNeeds &= ~NEED_CREDIT;
1742                                                         i2QueueNeeds(pB, pCh, NEED_INLINE);
1743                                                         if ( pCh->pTTY )
1744                                                                 ip2_owake(pCh->pTTY);
1745                                                 }
1746
1747                                                 ip2trace (channel, ITRC_STFLW, 3, 1, pCh->channelNeeds);
1748
1749                                                 pc += sizeof(flowStat);
1750                                                 break;
1751
1752                                         /* Special packets: */
1753                                         /* Just copy the information into the channel structure */
1754
1755                                         case STAT_STATUS:
1756
1757                                                 pCh->channelStatus = *((debugStatPtr)pc);
1758                                                 pc += sizeof(debugStat);
1759                                                 break;
1760
1761                                         case STAT_TXCNT:
1762
1763                                                 pCh->channelTcount = *((cntStatPtr)pc);
1764                                                 pc += sizeof(cntStat);
1765                                                 break;
1766
1767                                         case STAT_RXCNT:
1768
1769                                                 pCh->channelRcount = *((cntStatPtr)pc);
1770                                                 pc += sizeof(cntStat);
1771                                                 break;
1772
1773                                         case STAT_BOXIDS:
1774                                                 pB->channelBtypes = *((bidStatPtr)pc);
1775                                                 pc += sizeof(bidStat);
1776                                                 set_baud_params(pB);
1777                                                 break;
1778
1779                                         case STAT_HWFAIL:
1780                                                 i2QueueCommands (PTYPE_INLINE, pCh, 0, 1, CMD_HW_TEST);
1781                                                 pCh->channelFail = *((failStatPtr)pc);
1782                                                 pc += sizeof(failStat);
1783                                                 break;
1784
1785                                         /* No explicit match? then
1786                                          * Might be an error packet...
1787                                          */
1788                                         default:
1789                                                 switch (uc & STAT_MOD_ERROR)
1790                                                 {
1791                                                 case STAT_ERROR:
1792                                                         if (uc & STAT_E_PARITY) {
1793                                                                 pCh->dataSetIn |= I2_PAR;
1794                                                                 pCh->icount.parity++;
1795                                                         }
1796                                                         if (uc & STAT_E_FRAMING){
1797                                                                 pCh->dataSetIn |= I2_FRA;
1798                                                                 pCh->icount.frame++;
1799                                                         }
1800                                                         if (uc & STAT_E_OVERRUN){
1801                                                                 pCh->dataSetIn |= I2_OVR;
1802                                                                 pCh->icount.overrun++;
1803                                                         }
1804                                                         break;
1805
1806                                                 case STAT_MODEM:
1807                                                         // the answer to DSS_NOW request (not change)
1808                                                         pCh->dataSetIn = (pCh->dataSetIn
1809                                                                 & ~(I2_RI | I2_CTS | I2_DCD | I2_DSR) )
1810                                                                 | xlatDss[uc & 0xf];
1811                                                         wake_up_interruptible ( &pCh->dss_now_wait );
1812                                                 default:
1813                                                         break;
1814                                                 }
1815                                         }  /* End of switch on status type */
1816                                         if (dss_change) {
1817 #ifdef USE_IQ
1818                                                 schedule_work(&pCh->tqueue_status);
1819 #else
1820                                                 do_status(pCh);
1821 #endif
1822                                         }
1823                                 }
1824                                 else  /* Or else, channel is invalid */
1825                                 {
1826                                         // Even though the channel is invalid, we must test the
1827                                         // status to see how much additional data it has (to be
1828                                         // skipped)
1829                                         switch (*pc++)
1830                                         {
1831                                         case STAT_FLOW:
1832                                                 pc += 4;    /* Skip the data */
1833                                                 break;
1834
1835                                         default:
1836                                                 break;
1837                                         }
1838                                 }
1839                         }  // End of while (there is still some status packet left)
1840                         break;
1841
1842                 default: // Neither packet? should be impossible
1843                         ip2trace (ITRC_NO_PORT, ITRC_SFIFO, 5, 1,
1844                                 PTYPE_OF(pB->i2eLeadoffWord) );
1845
1846                         break;
1847                 }  // End of switch on type of packets
1848         }       //while(board HAS_INPUT)
1849
1850         ip2trace (ITRC_NO_PORT, ITRC_SFIFO, ITRC_RETURN, 0 );
1851
1852         // Send acknowledgement to the board even if there was no data!
1853         pB->i2eOutMailWaiting |= MB_IN_STRIPPED;
1854         return;
1855 }
1856
1857 //******************************************************************************
1858 // Function:   i2Write2Fifo(pB,address,count)
1859 // Parameters: Pointer to a board structure, source address, byte count
1860 // Returns:    bytes written
1861 //
1862 // Description:
1863 //  Writes count bytes to board io address(implied) from source
1864 //  Adjusts count, leaves reserve for next time around bypass cmds
1865 //******************************************************************************
1866 static int
1867 i2Write2Fifo(i2eBordStrPtr pB, unsigned char *source, int count,int reserve)
1868 {
1869         int rc = 0;
1870         unsigned long flags;
1871         WRITE_LOCK_IRQSAVE(&pB->write_fifo_spinlock,flags);
1872         if (!pB->i2eWaitingForEmptyFifo) {
1873                 if (pB->i2eFifoRemains > (count+reserve)) {
1874                         pB->i2eFifoRemains -= count;
1875                         iiWriteBuf(pB, source, count);
1876                         pB->i2eOutMailWaiting |= MB_OUT_STUFFED;
1877                         rc =  count;
1878                 }
1879         }
1880         WRITE_UNLOCK_IRQRESTORE(&pB->write_fifo_spinlock,flags);
1881         return rc;
1882 }
1883 //******************************************************************************
1884 // Function:   i2StuffFifoBypass(pB)
1885 // Parameters: Pointer to a board structure
1886 // Returns:    Nothing
1887 //
1888 // Description:
1889 // Stuffs as many bypass commands into the fifo as possible. This is simpler
1890 // than stuffing data or inline commands to fifo, since we do not have
1891 // flow-control to deal with.
1892 //******************************************************************************
1893 static inline void
1894 i2StuffFifoBypass(i2eBordStrPtr pB)
1895 {
1896         i2ChanStrPtr pCh;
1897         unsigned char *pRemove;
1898         unsigned short stripIndex;
1899         unsigned short packetSize;
1900         unsigned short paddedSize;
1901         unsigned short notClogged = 1;
1902         unsigned long flags;
1903
1904         int bailout = 1000;
1905
1906         // Continue processing so long as there are entries, or there is room in the
1907         // fifo. Each entry represents a channel with something to do.
1908         while ( --bailout && notClogged && 
1909                         (NULL != (pCh = i2DeQueueNeeds(pB,NEED_BYPASS))))
1910         {
1911                 WRITE_LOCK_IRQSAVE(&pCh->Cbuf_spinlock,flags);
1912                 stripIndex = pCh->Cbuf_strip;
1913
1914                 // as long as there are packets for this channel...
1915
1916                 while (stripIndex != pCh->Cbuf_stuff) {
1917                         pRemove = &(pCh->Cbuf[stripIndex]);
1918                         packetSize = CMD_COUNT_OF(pRemove) + sizeof(i2CmdHeader);
1919                         paddedSize = ROUNDUP(packetSize);
1920
1921                         if (paddedSize > 0) {
1922                                 if ( 0 == i2Write2Fifo(pB, pRemove, paddedSize,0)) {
1923                                         notClogged = 0; /* fifo full */
1924                                         i2QueueNeeds(pB, pCh, NEED_BYPASS);     // Put back on queue
1925                                         break;   // Break from the channel
1926                                 } 
1927                         }
1928 #ifdef DEBUG_FIFO
1929 WriteDBGBuf("BYPS", pRemove, paddedSize);
1930 #endif  /* DEBUG_FIFO */
1931                         pB->debugBypassCount++;
1932
1933                         pRemove += packetSize;
1934                         stripIndex += packetSize;
1935                         if (stripIndex >= CBUF_SIZE) {
1936                                 stripIndex = 0;
1937                                 pRemove = pCh->Cbuf;
1938                         }
1939                 }
1940                 // Done with this channel. Move to next, removing this one from 
1941                 // the queue of channels if we cleaned it out (i.e., didn't get clogged.
1942                 pCh->Cbuf_strip = stripIndex;
1943                 WRITE_UNLOCK_IRQRESTORE(&pCh->Cbuf_spinlock,flags);
1944         }  // Either clogged or finished all the work
1945
1946 #ifdef IP2DEBUG_TRACE
1947         if ( !bailout ) {
1948                 ip2trace (ITRC_NO_PORT, ITRC_ERROR, 1, 0 );
1949         }
1950 #endif
1951 }
1952
1953 //******************************************************************************
1954 // Function:   i2StuffFifoFlow(pB)
1955 // Parameters: Pointer to a board structure
1956 // Returns:    Nothing
1957 //
1958 // Description:
1959 // Stuffs as many flow control packets into the fifo as possible. This is easier
1960 // even than doing normal bypass commands, because there is always at most one
1961 // packet, already assembled, for each channel.
1962 //******************************************************************************
1963 static inline void
1964 i2StuffFifoFlow(i2eBordStrPtr pB)
1965 {
1966         i2ChanStrPtr pCh;
1967         unsigned short paddedSize               = ROUNDUP(sizeof(flowIn));
1968
1969         ip2trace (ITRC_NO_PORT, ITRC_SFLOW, ITRC_ENTER, 2,
1970                 pB->i2eFifoRemains, paddedSize );
1971
1972         // Continue processing so long as there are entries, or there is room in the
1973         // fifo. Each entry represents a channel with something to do.
1974         while ( (NULL != (pCh = i2DeQueueNeeds(pB,NEED_FLOW)))) {
1975                 pB->debugFlowCount++;
1976
1977                 // NO Chan LOCK needed ???
1978                 if ( 0 == i2Write2Fifo(pB,(unsigned char *)&(pCh->infl),paddedSize,0)) {
1979                         break;
1980                 }
1981 #ifdef DEBUG_FIFO
1982                 WriteDBGBuf("FLOW",(unsigned char *) &(pCh->infl), paddedSize);
1983 #endif /* DEBUG_FIFO */
1984
1985         }  // Either clogged or finished all the work
1986
1987         ip2trace (ITRC_NO_PORT, ITRC_SFLOW, ITRC_RETURN, 0 );
1988 }
1989
1990 //******************************************************************************
1991 // Function:   i2StuffFifoInline(pB)
1992 // Parameters: Pointer to a board structure
1993 // Returns:    Nothing
1994 //
1995 // Description:
1996 // Stuffs as much data and inline commands into the fifo as possible. This is
1997 // the most complex fifo-stuffing operation, since there if now the channel
1998 // flow-control issue to deal with.
1999 //******************************************************************************
2000 static inline void
2001 i2StuffFifoInline(i2eBordStrPtr pB)
2002 {
2003         i2ChanStrPtr pCh;
2004         unsigned char *pRemove;
2005         unsigned short stripIndex;
2006         unsigned short packetSize;
2007         unsigned short paddedSize;
2008         unsigned short notClogged = 1;
2009         unsigned short flowsize;
2010         unsigned long flags;
2011
2012         int bailout  = 1000;
2013         int bailout2;
2014
2015         ip2trace (ITRC_NO_PORT, ITRC_SICMD, ITRC_ENTER, 3, pB->i2eFifoRemains, 
2016                         pB->i2Dbuf_strip, pB->i2Dbuf_stuff );
2017
2018         // Continue processing so long as there are entries, or there is room in the
2019         // fifo. Each entry represents a channel with something to do.
2020         while ( --bailout && notClogged && 
2021                         (NULL != (pCh = i2DeQueueNeeds(pB,NEED_INLINE))) )
2022         {
2023                 WRITE_LOCK_IRQSAVE(&pCh->Obuf_spinlock,flags);
2024                 stripIndex = pCh->Obuf_strip;
2025
2026                 ip2trace (CHANN, ITRC_SICMD, 3, 2, stripIndex, pCh->Obuf_stuff );
2027
2028                 // as long as there are packets for this channel...
2029                 bailout2 = 1000;
2030                 while ( --bailout2 && stripIndex != pCh->Obuf_stuff) {
2031                         pRemove = &(pCh->Obuf[stripIndex]);
2032
2033                         // Must determine whether this be a data or command packet to
2034                         // calculate correctly the header size and the amount of
2035                         // flow-control credit this type of packet will use.
2036                         if (PTYPE_OF(pRemove) == PTYPE_DATA) {
2037                                 flowsize = DATA_COUNT_OF(pRemove);
2038                                 packetSize = flowsize + sizeof(i2DataHeader);
2039                         } else {
2040                                 flowsize = CMD_COUNT_OF(pRemove);
2041                                 packetSize = flowsize + sizeof(i2CmdHeader);
2042                         }
2043                         flowsize = CREDIT_USAGE(flowsize);
2044                         paddedSize = ROUNDUP(packetSize);
2045
2046                         ip2trace (CHANN, ITRC_SICMD, 4, 2, pB->i2eFifoRemains, paddedSize );
2047
2048                         // If we don't have enough credits from the board to send the data,
2049                         // flag the channel that we are waiting for flow control credit, and
2050                         // break out. This will clean up this channel and remove us from the
2051                         // queue of hot things to do.
2052
2053                                 ip2trace (CHANN, ITRC_SICMD, 5, 2, pCh->outfl.room, flowsize );
2054
2055                         if (pCh->outfl.room <= flowsize)        {
2056                                 // Do Not have the credits to send this packet.
2057                                 i2QueueNeeds(pB, pCh, NEED_CREDIT);
2058                                 notClogged = 0;
2059                                 break;   // So to do next channel
2060                         }
2061                         if ( (paddedSize > 0) 
2062                                 && ( 0 == i2Write2Fifo(pB, pRemove, paddedSize, 128))) {
2063                                 // Do Not have room in fifo to send this packet.
2064                                 notClogged = 0;
2065                                 i2QueueNeeds(pB, pCh, NEED_INLINE);     
2066                                 break;   // Break from the channel
2067                         }
2068 #ifdef DEBUG_FIFO
2069 WriteDBGBuf("DATA", pRemove, paddedSize);
2070 #endif /* DEBUG_FIFO */
2071                         pB->debugInlineCount++;
2072
2073                         pCh->icount.tx += flowsize;
2074                         // Update current credits
2075                         pCh->outfl.room -= flowsize;
2076                         pCh->outfl.asof += flowsize;
2077                         if (PTYPE_OF(pRemove) == PTYPE_DATA) {
2078                                 pCh->Obuf_char_count -= DATA_COUNT_OF(pRemove);
2079                         }
2080                         pRemove += packetSize;
2081                         stripIndex += packetSize;
2082
2083                         ip2trace (CHANN, ITRC_SICMD, 6, 2, stripIndex, pCh->Obuf_strip);
2084
2085                         if (stripIndex >= OBUF_SIZE) {
2086                                 stripIndex = 0;
2087                                 pRemove = pCh->Obuf;
2088
2089                                 ip2trace (CHANN, ITRC_SICMD, 7, 1, stripIndex );
2090
2091                         }
2092                 }       /* while */
2093                 if ( !bailout2 ) {
2094                         ip2trace (CHANN, ITRC_ERROR, 3, 0 );
2095                 }
2096                 // Done with this channel. Move to next, removing this one from the
2097                 // queue of channels if we cleaned it out (i.e., didn't get clogged.
2098                 pCh->Obuf_strip = stripIndex;
2099                 WRITE_UNLOCK_IRQRESTORE(&pCh->Obuf_spinlock,flags);
2100                 if ( notClogged )
2101                 {
2102
2103                         ip2trace (CHANN, ITRC_SICMD, 8, 0 );
2104
2105                         if ( pCh->pTTY ) {
2106                                 ip2_owake(pCh->pTTY);
2107                         }
2108                 }
2109         }  // Either clogged or finished all the work
2110
2111         if ( !bailout ) {
2112                 ip2trace (ITRC_NO_PORT, ITRC_ERROR, 4, 0 );
2113         }
2114
2115         ip2trace (ITRC_NO_PORT, ITRC_SICMD, ITRC_RETURN, 1,pB->i2Dbuf_strip);
2116 }
2117
2118 //******************************************************************************
2119 // Function:   serviceOutgoingFifo(pB)
2120 // Parameters: Pointer to a board structure
2121 // Returns:    Nothing
2122 //
2123 // Description:
2124 // Helper routine to put data in the outgoing fifo, if we aren't already waiting
2125 // for something to be there. If the fifo has only room for a very little data,
2126 // go head and hit the board with a mailbox hit immediately. Otherwise, it will
2127 // have to happen later in the interrupt processing. Since this routine may be
2128 // called both at interrupt and foreground time, we must turn off interrupts
2129 // during the entire process.
2130 //******************************************************************************
2131 static void
2132 serviceOutgoingFifo(i2eBordStrPtr pB)
2133 {
2134         // If we aren't currently waiting for the board to empty our fifo, service
2135         // everything that is pending, in priority order (especially, Bypass before
2136         // Inline).
2137         if ( ! pB->i2eWaitingForEmptyFifo )
2138         {
2139                 i2StuffFifoFlow(pB);
2140                 i2StuffFifoBypass(pB);
2141                 i2StuffFifoInline(pB);
2142
2143                 iiSendPendingMail(pB);
2144         } 
2145 }
2146
2147 //******************************************************************************
2148 // Function:   i2ServiceBoard(pB)
2149 // Parameters: Pointer to a board structure
2150 // Returns:    Nothing
2151 //
2152 // Description:
2153 // Normally this is called from interrupt level, but there is deliberately
2154 // nothing in here specific to being called from interrupt level. All the
2155 // hardware-specific, interrupt-specific things happen at the outer levels.
2156 //
2157 // For example, a timer interrupt could drive this routine for some sort of
2158 // polled operation. The only requirement is that the programmer deal with any
2159 // atomiticity/concurrency issues that result.
2160 //
2161 // This routine responds to the board's having sent mailbox information to the
2162 // host (which would normally cause an interrupt). This routine reads the
2163 // incoming mailbox. If there is no data in it, this board did not create the
2164 // interrupt and/or has nothing to be done to it. (Except, if we have been
2165 // waiting to write mailbox data to it, we may do so.
2166 //
2167 // Based on the value in the mailbox, we may take various actions.
2168 //
2169 // No checking here of pB validity: after all, it shouldn't have been called by
2170 // the handler unless pB were on the list.
2171 //******************************************************************************
2172 static inline int
2173 i2ServiceBoard ( i2eBordStrPtr pB )
2174 {
2175         unsigned inmail;
2176         unsigned long flags;
2177
2178
2179         /* This should be atomic because of the way we are called... */
2180         if (NO_MAIL_HERE == ( inmail = pB->i2eStartMail ) ) {
2181                 inmail = iiGetMail(pB);
2182         }
2183         pB->i2eStartMail = NO_MAIL_HERE;
2184
2185         ip2trace (ITRC_NO_PORT, ITRC_INTR, 2, 1, inmail );
2186
2187         if (inmail != NO_MAIL_HERE) {
2188                 // If the board has gone fatal, nothing to do but hit a bit that will
2189                 // alert foreground tasks to protest!
2190                 if ( inmail & MB_FATAL_ERROR ) {
2191                         pB->i2eFatal = 1;
2192                         goto exit_i2ServiceBoard;
2193                 }
2194
2195                 /* Assuming no fatal condition, we proceed to do work */
2196                 if ( inmail & MB_IN_STUFFED ) {
2197                         pB->i2eFifoInInts++;
2198                         i2StripFifo(pB);     /* There might be incoming packets */
2199                 }
2200
2201                 if (inmail & MB_OUT_STRIPPED) {
2202                         pB->i2eFifoOutInts++;
2203                         WRITE_LOCK_IRQSAVE(&pB->write_fifo_spinlock,flags);
2204                         pB->i2eFifoRemains = pB->i2eFifoSize;
2205                         pB->i2eWaitingForEmptyFifo = 0;
2206                         WRITE_UNLOCK_IRQRESTORE(&pB->write_fifo_spinlock,flags);
2207
2208                         ip2trace (ITRC_NO_PORT, ITRC_INTR, 30, 1, pB->i2eFifoRemains );
2209
2210                 }
2211                 serviceOutgoingFifo(pB);
2212         }
2213
2214         ip2trace (ITRC_NO_PORT, ITRC_INTR, 8, 0 );
2215
2216 exit_i2ServiceBoard:
2217
2218         return 0;
2219 }