1 /*
2 * atari_scsi.c -- Device dependent functions for the Atari generic SCSI port
3 *
4 * Copyright 1994 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de>
5 *
6 * Loosely based on the work of Robert De Vries' team and added:
7 * - working real DMA
8 * - Falcon support (untested yet!) ++bjoern fixed and now it works
9 * - lots of extensions and bug fixes.
10 *
11 * This file is subject to the terms and conditions of the GNU General Public
12 * License. See the file COPYING in the main directory of this archive
13 * for more details.
14 *
15 */
16
17
18 /**************************************************************************/
19 /* */
20 /* Notes for Falcon SCSI: */
21 /* ---------------------- */
22 /* */
23 /* Since the Falcon SCSI uses the ST-DMA chip, that is shared among */
24 /* several device drivers, locking and unlocking the access to this */
25 /* chip is required. But locking is not possible from an interrupt, */
26 /* since it puts the process to sleep if the lock is not available. */
27 /* This prevents "late" locking of the DMA chip, i.e. locking it just */
28 /* before using it, since in case of disconnection-reconnection */
29 /* commands, the DMA is started from the reselection interrupt. */
30 /* */
31 /* Two possible schemes for ST-DMA-locking would be: */
32 /* 1) The lock is taken for each command separately and disconnecting */
33 /* is forbidden (i.e. can_queue = 1). */
34 /* 2) The DMA chip is locked when the first command comes in and */
35 /* released when the last command is finished and all queues are */
36 /* empty. */
37 /* The first alternative would result in bad performance, since the */
38 /* interleaving of commands would not be used. The second is unfair to */
39 /* other drivers using the ST-DMA, because the queues will seldom be */
40 /* totally empty if there is a lot of disk traffic. */
41 /* */
42 /* For this reasons I decided to employ a more elaborate scheme: */
43 /* - First, we give up the lock every time we can (for fairness), this */
44 /* means every time a command finishes and there are no other commands */
45 /* on the disconnected queue. */
46 /* - If there are others waiting to lock the DMA chip, we stop */
47 /* issuing commands, i.e. moving them onto the issue queue. */
48 /* Because of that, the disconnected queue will run empty in a */
49 /* while. Instead we go to sleep on a 'fairness_queue'. */
50 /* - If the lock is released, all processes waiting on the fairness */
51 /* queue will be woken. The first of them tries to re-lock the DMA, */
52 /* the others wait for the first to finish this task. After that, */
53 /* they can all run on and do their commands... */
54 /* This sounds complicated (and it is it :-(), but it seems to be a */
55 /* good compromise between fairness and performance: As long as no one */
56 /* else wants to work with the ST-DMA chip, SCSI can go along as */
57 /* usual. If now someone else comes, this behaviour is changed to a */
58 /* "fairness mode": just already initiated commands are finished and */
59 /* then the lock is released. The other one waiting will probably win */
60 /* the race for locking the DMA, since it was waiting for longer. And */
61 /* after it has finished, SCSI can go ahead again. Finally: I hope I */
62 /* have not produced any deadlock possibilities! */
63 /* */
64 /**************************************************************************/
65
66
67
68 #include <linux/module.h>
69
70 #define NDEBUG (0)
71
72 #define NDEBUG_ABORT 0x00100000
73 #define NDEBUG_TAGS 0x00200000
74 #define NDEBUG_MERGING 0x00400000
75
76 #define AUTOSENSE
77 /* For the Atari version, use only polled IO or REAL_DMA */
78 #define REAL_DMA
79 /* Support tagged queuing? (on devices that are able to... :-) */
80 #define SUPPORT_TAGS
81 #define MAX_TAGS 32
82
83 #include <linux/types.h>
84 #include <linux/stddef.h>
85 #include <linux/ctype.h>
86 #include <linux/delay.h>
87 #include <linux/mm.h>
88 #include <linux/blkdev.h>
89 #include <linux/interrupt.h>
90 #include <linux/init.h>
91 #include <linux/nvram.h>
92 #include <linux/bitops.h>
93
94 #include <asm/setup.h>
95 #include <asm/atarihw.h>
96 #include <asm/atariints.h>
97 #include <asm/page.h>
98 #include <asm/pgtable.h>
99 #include <asm/irq.h>
100 #include <asm/traps.h>
101
102 #include "scsi.h"
103 #include <scsi/scsi_host.h>
104 #include "atari_scsi.h"
105 #include "NCR5380.h"
106 #include <asm/atari_stdma.h>
107 #include <asm/atari_stram.h>
108 #include <asm/io.h>
109
110 #include <linux/stat.h>
111
112 #define IS_A_TT() ATARIHW_PRESENT(TT_SCSI)
113
114 #define SCSI_DMA_WRITE_P(elt,val) \
115 do { \
116 unsigned long v = val; \
117 tt_scsi_dma.elt##_lo = v & 0xff; \
118 v >>= 8; \
119 tt_scsi_dma.elt##_lmd = v & 0xff; \
120 v >>= 8; \
121 tt_scsi_dma.elt##_hmd = v & 0xff; \
122 v >>= 8; \
123 tt_scsi_dma.elt##_hi = v & 0xff; \
124 } while(0)
125
126 #define SCSI_DMA_READ_P(elt) \
127 (((((((unsigned long)tt_scsi_dma.elt##_hi << 8) | \
128 (unsigned long)tt_scsi_dma.elt##_hmd) << 8) | \
129 (unsigned long)tt_scsi_dma.elt##_lmd) << 8) | \
130 (unsigned long)tt_scsi_dma.elt##_lo)
131
132
SCSI_DMA_SETADR(unsigned long adr)133 static inline void SCSI_DMA_SETADR(unsigned long adr)
134 {
135 st_dma.dma_lo = (unsigned char)adr;
136 MFPDELAY();
137 adr >>= 8;
138 st_dma.dma_md = (unsigned char)adr;
139 MFPDELAY();
140 adr >>= 8;
141 st_dma.dma_hi = (unsigned char)adr;
142 MFPDELAY();
143 }
144
SCSI_DMA_GETADR(void)145 static inline unsigned long SCSI_DMA_GETADR(void)
146 {
147 unsigned long adr;
148 adr = st_dma.dma_lo;
149 MFPDELAY();
150 adr |= (st_dma.dma_md & 0xff) << 8;
151 MFPDELAY();
152 adr |= (st_dma.dma_hi & 0xff) << 16;
153 MFPDELAY();
154 return adr;
155 }
156
ENABLE_IRQ(void)157 static inline void ENABLE_IRQ(void)
158 {
159 if (IS_A_TT())
160 atari_enable_irq(IRQ_TT_MFP_SCSI);
161 else
162 atari_enable_irq(IRQ_MFP_FSCSI);
163 }
164
DISABLE_IRQ(void)165 static inline void DISABLE_IRQ(void)
166 {
167 if (IS_A_TT())
168 atari_disable_irq(IRQ_TT_MFP_SCSI);
169 else
170 atari_disable_irq(IRQ_MFP_FSCSI);
171 }
172
173
174 #define HOSTDATA_DMALEN (((struct NCR5380_hostdata *) \
175 (atari_scsi_host->hostdata))->dma_len)
176
177 /* Time (in jiffies) to wait after a reset; the SCSI standard calls for 250ms,
178 * we usually do 0.5s to be on the safe side. But Toshiba CD-ROMs once more
179 * need ten times the standard value... */
180 #ifndef CONFIG_ATARI_SCSI_TOSHIBA_DELAY
181 #define AFTER_RESET_DELAY (HZ/2)
182 #else
183 #define AFTER_RESET_DELAY (5*HZ/2)
184 #endif
185
186 /***************************** Prototypes *****************************/
187
188 #ifdef REAL_DMA
189 static int scsi_dma_is_ignored_buserr(unsigned char dma_stat);
190 static void atari_scsi_fetch_restbytes(void);
191 static long atari_scsi_dma_residual(struct Scsi_Host *instance);
192 static int falcon_classify_cmd(Scsi_Cmnd *cmd);
193 static unsigned long atari_dma_xfer_len(unsigned long wanted_len,
194 Scsi_Cmnd *cmd, int write_flag);
195 #endif
196 static irqreturn_t scsi_tt_intr(int irq, void *dummy);
197 static irqreturn_t scsi_falcon_intr(int irq, void *dummy);
198 static void falcon_release_lock_if_possible(struct NCR5380_hostdata *hostdata);
199 static void falcon_get_lock(void);
200 #ifdef CONFIG_ATARI_SCSI_RESET_BOOT
201 static void atari_scsi_reset_boot(void);
202 #endif
203 static unsigned char atari_scsi_tt_reg_read(unsigned char reg);
204 static void atari_scsi_tt_reg_write(unsigned char reg, unsigned char value);
205 static unsigned char atari_scsi_falcon_reg_read(unsigned char reg);
206 static void atari_scsi_falcon_reg_write(unsigned char reg, unsigned char value);
207
208 /************************* End of Prototypes **************************/
209
210
211 static struct Scsi_Host *atari_scsi_host;
212 static unsigned char (*atari_scsi_reg_read)(unsigned char reg);
213 static void (*atari_scsi_reg_write)(unsigned char reg, unsigned char value);
214
215 #ifdef REAL_DMA
216 static unsigned long atari_dma_residual, atari_dma_startaddr;
217 static short atari_dma_active;
218 /* pointer to the dribble buffer */
219 static char *atari_dma_buffer;
220 /* precalculated physical address of the dribble buffer */
221 static unsigned long atari_dma_phys_buffer;
222 /* != 0 tells the Falcon int handler to copy data from the dribble buffer */
223 static char *atari_dma_orig_addr;
224 /* size of the dribble buffer; 4k seems enough, since the Falcon cannot use
225 * scatter-gather anyway, so most transfers are 1024 byte only. In the rare
226 * cases where requests to physical contiguous buffers have been merged, this
227 * request is <= 4k (one page). So I don't think we have to split transfers
228 * just due to this buffer size...
229 */
230 #define STRAM_BUFFER_SIZE (4096)
231 /* mask for address bits that can't be used with the ST-DMA */
232 static unsigned long atari_dma_stram_mask;
233 #define STRAM_ADDR(a) (((a) & atari_dma_stram_mask) == 0)
234 /* number of bytes to cut from a transfer to handle NCR overruns */
235 static int atari_read_overruns;
236 #endif
237
238 static int setup_can_queue = -1;
239 module_param(setup_can_queue, int, 0);
240 static int setup_cmd_per_lun = -1;
241 module_param(setup_cmd_per_lun, int, 0);
242 static int setup_sg_tablesize = -1;
243 module_param(setup_sg_tablesize, int, 0);
244 #ifdef SUPPORT_TAGS
245 static int setup_use_tagged_queuing = -1;
246 module_param(setup_use_tagged_queuing, int, 0);
247 #endif
248 static int setup_hostid = -1;
249 module_param(setup_hostid, int, 0);
250
251
252 #if defined(REAL_DMA)
253
scsi_dma_is_ignored_buserr(unsigned char dma_stat)254 static int scsi_dma_is_ignored_buserr(unsigned char dma_stat)
255 {
256 int i;
257 unsigned long addr = SCSI_DMA_READ_P(dma_addr), end_addr;
258
259 if (dma_stat & 0x01) {
260
261 /* A bus error happens when DMA-ing from the last page of a
262 * physical memory chunk (DMA prefetch!), but that doesn't hurt.
263 * Check for this case:
264 */
265
266 for (i = 0; i < m68k_num_memory; ++i) {
267 end_addr = m68k_memory[i].addr + m68k_memory[i].size;
268 if (end_addr <= addr && addr <= end_addr + 4)
269 return 1;
270 }
271 }
272 return 0;
273 }
274
275
276 #if 0
277 /* Dead code... wasn't called anyway :-) and causes some trouble, because at
278 * end-of-DMA, both SCSI ints are triggered simultaneously, so the NCR int has
279 * to clear the DMA int pending bit before it allows other level 6 interrupts.
280 */
281 static void scsi_dma_buserr(int irq, void *dummy)
282 {
283 unsigned char dma_stat = tt_scsi_dma.dma_ctrl;
284
285 /* Don't do anything if a NCR interrupt is pending. Probably it's just
286 * masked... */
287 if (atari_irq_pending(IRQ_TT_MFP_SCSI))
288 return;
289
290 printk("Bad SCSI DMA interrupt! dma_addr=0x%08lx dma_stat=%02x dma_cnt=%08lx\n",
291 SCSI_DMA_READ_P(dma_addr), dma_stat, SCSI_DMA_READ_P(dma_cnt));
292 if (dma_stat & 0x80) {
293 if (!scsi_dma_is_ignored_buserr(dma_stat))
294 printk("SCSI DMA bus error -- bad DMA programming!\n");
295 } else {
296 /* Under normal circumstances we never should get to this point,
297 * since both interrupts are triggered simultaneously and the 5380
298 * int has higher priority. When this irq is handled, that DMA
299 * interrupt is cleared. So a warning message is printed here.
300 */
301 printk("SCSI DMA intr ?? -- this shouldn't happen!\n");
302 }
303 }
304 #endif
305
306 #endif
307
308
scsi_tt_intr(int irq,void * dummy)309 static irqreturn_t scsi_tt_intr(int irq, void *dummy)
310 {
311 #ifdef REAL_DMA
312 int dma_stat;
313
314 dma_stat = tt_scsi_dma.dma_ctrl;
315
316 INT_PRINTK("scsi%d: NCR5380 interrupt, DMA status = %02x\n",
317 atari_scsi_host->host_no, dma_stat & 0xff);
318
319 /* Look if it was the DMA that has interrupted: First possibility
320 * is that a bus error occurred...
321 */
322 if (dma_stat & 0x80) {
323 if (!scsi_dma_is_ignored_buserr(dma_stat)) {
324 printk(KERN_ERR "SCSI DMA caused bus error near 0x%08lx\n",
325 SCSI_DMA_READ_P(dma_addr));
326 printk(KERN_CRIT "SCSI DMA bus error -- bad DMA programming!");
327 }
328 }
329
330 /* If the DMA is active but not finished, we have the case
331 * that some other 5380 interrupt occurred within the DMA transfer.
332 * This means we have residual bytes, if the desired end address
333 * is not yet reached. Maybe we have to fetch some bytes from the
334 * rest data register, too. The residual must be calculated from
335 * the address pointer, not the counter register, because only the
336 * addr reg counts bytes not yet written and pending in the rest
337 * data reg!
338 */
339 if ((dma_stat & 0x02) && !(dma_stat & 0x40)) {
340 atari_dma_residual = HOSTDATA_DMALEN - (SCSI_DMA_READ_P(dma_addr) - atari_dma_startaddr);
341
342 DMA_PRINTK("SCSI DMA: There are %ld residual bytes.\n",
343 atari_dma_residual);
344
345 if ((signed int)atari_dma_residual < 0)
346 atari_dma_residual = 0;
347 if ((dma_stat & 1) == 0) {
348 /*
349 * After read operations, we maybe have to
350 * transport some rest bytes
351 */
352 atari_scsi_fetch_restbytes();
353 } else {
354 /*
355 * There seems to be a nasty bug in some SCSI-DMA/NCR
356 * combinations: If a target disconnects while a write
357 * operation is going on, the address register of the
358 * DMA may be a few bytes farer than it actually read.
359 * This is probably due to DMA prefetching and a delay
360 * between DMA and NCR. Experiments showed that the
361 * dma_addr is 9 bytes to high, but this could vary.
362 * The problem is, that the residual is thus calculated
363 * wrong and the next transfer will start behind where
364 * it should. So we round up the residual to the next
365 * multiple of a sector size, if it isn't already a
366 * multiple and the originally expected transfer size
367 * was. The latter condition is there to ensure that
368 * the correction is taken only for "real" data
369 * transfers and not for, e.g., the parameters of some
370 * other command. These shouldn't disconnect anyway.
371 */
372 if (atari_dma_residual & 0x1ff) {
373 DMA_PRINTK("SCSI DMA: DMA bug corrected, "
374 "difference %ld bytes\n",
375 512 - (atari_dma_residual & 0x1ff));
376 atari_dma_residual = (atari_dma_residual + 511) & ~0x1ff;
377 }
378 }
379 tt_scsi_dma.dma_ctrl = 0;
380 }
381
382 /* If the DMA is finished, fetch the rest bytes and turn it off */
383 if (dma_stat & 0x40) {
384 atari_dma_residual = 0;
385 if ((dma_stat & 1) == 0)
386 atari_scsi_fetch_restbytes();
387 tt_scsi_dma.dma_ctrl = 0;
388 }
389
390 #endif /* REAL_DMA */
391
392 NCR5380_intr(irq, dummy);
393
394 #if 0
395 /* To be sure the int is not masked */
396 atari_enable_irq(IRQ_TT_MFP_SCSI);
397 #endif
398 return IRQ_HANDLED;
399 }
400
401
scsi_falcon_intr(int irq,void * dummy)402 static irqreturn_t scsi_falcon_intr(int irq, void *dummy)
403 {
404 #ifdef REAL_DMA
405 int dma_stat;
406
407 /* Turn off DMA and select sector counter register before
408 * accessing the status register (Atari recommendation!)
409 */
410 st_dma.dma_mode_status = 0x90;
411 dma_stat = st_dma.dma_mode_status;
412
413 /* Bit 0 indicates some error in the DMA process... don't know
414 * what happened exactly (no further docu).
415 */
416 if (!(dma_stat & 0x01)) {
417 /* DMA error */
418 printk(KERN_CRIT "SCSI DMA error near 0x%08lx!\n", SCSI_DMA_GETADR());
419 }
420
421 /* If the DMA was active, but now bit 1 is not clear, it is some
422 * other 5380 interrupt that finishes the DMA transfer. We have to
423 * calculate the number of residual bytes and give a warning if
424 * bytes are stuck in the ST-DMA fifo (there's no way to reach them!)
425 */
426 if (atari_dma_active && (dma_stat & 0x02)) {
427 unsigned long transferred;
428
429 transferred = SCSI_DMA_GETADR() - atari_dma_startaddr;
430 /* The ST-DMA address is incremented in 2-byte steps, but the
431 * data are written only in 16-byte chunks. If the number of
432 * transferred bytes is not divisible by 16, the remainder is
433 * lost somewhere in outer space.
434 */
435 if (transferred & 15)
436 printk(KERN_ERR "SCSI DMA error: %ld bytes lost in "
437 "ST-DMA fifo\n", transferred & 15);
438
439 atari_dma_residual = HOSTDATA_DMALEN - transferred;
440 DMA_PRINTK("SCSI DMA: There are %ld residual bytes.\n",
441 atari_dma_residual);
442 } else
443 atari_dma_residual = 0;
444 atari_dma_active = 0;
445
446 if (atari_dma_orig_addr) {
447 /* If the dribble buffer was used on a read operation, copy the DMA-ed
448 * data to the original destination address.
449 */
450 memcpy(atari_dma_orig_addr, phys_to_virt(atari_dma_startaddr),
451 HOSTDATA_DMALEN - atari_dma_residual);
452 atari_dma_orig_addr = NULL;
453 }
454
455 #endif /* REAL_DMA */
456
457 NCR5380_intr(irq, dummy);
458 return IRQ_HANDLED;
459 }
460
461
462 #ifdef REAL_DMA
atari_scsi_fetch_restbytes(void)463 static void atari_scsi_fetch_restbytes(void)
464 {
465 int nr;
466 char *src, *dst;
467 unsigned long phys_dst;
468
469 /* fetch rest bytes in the DMA register */
470 phys_dst = SCSI_DMA_READ_P(dma_addr);
471 nr = phys_dst & 3;
472 if (nr) {
473 /* there are 'nr' bytes left for the last long address
474 before the DMA pointer */
475 phys_dst ^= nr;
476 DMA_PRINTK("SCSI DMA: there are %d rest bytes for phys addr 0x%08lx",
477 nr, phys_dst);
478 /* The content of the DMA pointer is a physical address! */
479 dst = phys_to_virt(phys_dst);
480 DMA_PRINTK(" = virt addr %p\n", dst);
481 for (src = (char *)&tt_scsi_dma.dma_restdata; nr != 0; --nr)
482 *dst++ = *src++;
483 }
484 }
485 #endif /* REAL_DMA */
486
487
488 static int falcon_got_lock = 0;
489 static DECLARE_WAIT_QUEUE_HEAD(falcon_fairness_wait);
490 static int falcon_trying_lock = 0;
491 static DECLARE_WAIT_QUEUE_HEAD(falcon_try_wait);
492 static int falcon_dont_release = 0;
493
494 /* This function releases the lock on the DMA chip if there is no
495 * connected command and the disconnected queue is empty. On
496 * releasing, instances of falcon_get_lock are awoken, that put
497 * themselves to sleep for fairness. They can now try to get the lock
498 * again (but others waiting longer more probably will win).
499 */
500
falcon_release_lock_if_possible(struct NCR5380_hostdata * hostdata)501 static void falcon_release_lock_if_possible(struct NCR5380_hostdata *hostdata)
502 {
503 unsigned long flags;
504
505 if (IS_A_TT())
506 return;
507
508 local_irq_save(flags);
509
510 if (falcon_got_lock && !hostdata->disconnected_queue &&
511 !hostdata->issue_queue && !hostdata->connected) {
512
513 if (falcon_dont_release) {
514 #if 0
515 printk("WARNING: Lock release not allowed. Ignored\n");
516 #endif
517 local_irq_restore(flags);
518 return;
519 }
520 falcon_got_lock = 0;
521 stdma_release();
522 wake_up(&falcon_fairness_wait);
523 }
524
525 local_irq_restore(flags);
526 }
527
528 /* This function manages the locking of the ST-DMA.
529 * If the DMA isn't locked already for SCSI, it tries to lock it by
530 * calling stdma_lock(). But if the DMA is locked by the SCSI code and
531 * there are other drivers waiting for the chip, we do not issue the
532 * command immediately but wait on 'falcon_fairness_queue'. We will be
533 * waked up when the DMA is unlocked by some SCSI interrupt. After that
534 * we try to get the lock again.
535 * But we must be prepared that more than one instance of
536 * falcon_get_lock() is waiting on the fairness queue. They should not
537 * try all at once to call stdma_lock(), one is enough! For that, the
538 * first one sets 'falcon_trying_lock', others that see that variable
539 * set wait on the queue 'falcon_try_wait'.
540 * Complicated, complicated.... Sigh...
541 */
542
falcon_get_lock(void)543 static void falcon_get_lock(void)
544 {
545 unsigned long flags;
546
547 if (IS_A_TT())
548 return;
549
550 local_irq_save(flags);
551
552 while (!in_irq() && falcon_got_lock && stdma_others_waiting())
553 sleep_on(&falcon_fairness_wait);
554
555 while (!falcon_got_lock) {
556 if (in_irq())
557 panic("Falcon SCSI hasn't ST-DMA lock in interrupt");
558 if (!falcon_trying_lock) {
559 falcon_trying_lock = 1;
560 stdma_lock(scsi_falcon_intr, NULL);
561 falcon_got_lock = 1;
562 falcon_trying_lock = 0;
563 wake_up(&falcon_try_wait);
564 } else {
565 sleep_on(&falcon_try_wait);
566 }
567 }
568
569 local_irq_restore(flags);
570 if (!falcon_got_lock)
571 panic("Falcon SCSI: someone stole the lock :-(\n");
572 }
573
574
atari_scsi_detect(struct scsi_host_template * host)575 int __init atari_scsi_detect(struct scsi_host_template *host)
576 {
577 static int called = 0;
578 struct Scsi_Host *instance;
579
580 if (!MACH_IS_ATARI ||
581 (!ATARIHW_PRESENT(ST_SCSI) && !ATARIHW_PRESENT(TT_SCSI)) ||
582 called)
583 return 0;
584
585 host->proc_name = "Atari";
586
587 atari_scsi_reg_read = IS_A_TT() ? atari_scsi_tt_reg_read :
588 atari_scsi_falcon_reg_read;
589 atari_scsi_reg_write = IS_A_TT() ? atari_scsi_tt_reg_write :
590 atari_scsi_falcon_reg_write;
591
592 /* setup variables */
593 host->can_queue =
594 (setup_can_queue > 0) ? setup_can_queue :
595 IS_A_TT() ? ATARI_TT_CAN_QUEUE : ATARI_FALCON_CAN_QUEUE;
596 host->cmd_per_lun =
597 (setup_cmd_per_lun > 0) ? setup_cmd_per_lun :
598 IS_A_TT() ? ATARI_TT_CMD_PER_LUN : ATARI_FALCON_CMD_PER_LUN;
599 /* Force sg_tablesize to 0 on a Falcon! */
600 host->sg_tablesize =
601 !IS_A_TT() ? ATARI_FALCON_SG_TABLESIZE :
602 (setup_sg_tablesize >= 0) ? setup_sg_tablesize : ATARI_TT_SG_TABLESIZE;
603
604 if (setup_hostid >= 0)
605 host->this_id = setup_hostid;
606 else {
607 /* use 7 as default */
608 host->this_id = 7;
609 /* Test if a host id is set in the NVRam */
610 if (ATARIHW_PRESENT(TT_CLK) && nvram_check_checksum()) {
611 unsigned char b = nvram_read_byte( 14 );
612 /* Arbitration enabled? (for TOS) If yes, use configured host ID */
613 if (b & 0x80)
614 host->this_id = b & 7;
615 }
616 }
617
618 #ifdef SUPPORT_TAGS
619 if (setup_use_tagged_queuing < 0)
620 setup_use_tagged_queuing = DEFAULT_USE_TAGGED_QUEUING;
621 #endif
622 #ifdef REAL_DMA
623 /* If running on a Falcon and if there's TT-Ram (i.e., more than one
624 * memory block, since there's always ST-Ram in a Falcon), then allocate a
625 * STRAM_BUFFER_SIZE byte dribble buffer for transfers from/to alternative
626 * Ram.
627 */
628 if (MACH_IS_ATARI && ATARIHW_PRESENT(ST_SCSI) &&
629 !ATARIHW_PRESENT(EXTD_DMA) && m68k_num_memory > 1) {
630 atari_dma_buffer = atari_stram_alloc(STRAM_BUFFER_SIZE, "SCSI");
631 if (!atari_dma_buffer) {
632 printk(KERN_ERR "atari_scsi_detect: can't allocate ST-RAM "
633 "double buffer\n");
634 return 0;
635 }
636 atari_dma_phys_buffer = virt_to_phys(atari_dma_buffer);
637 atari_dma_orig_addr = 0;
638 }
639 #endif
640 instance = scsi_register(host, sizeof(struct NCR5380_hostdata));
641 if (instance == NULL) {
642 atari_stram_free(atari_dma_buffer);
643 atari_dma_buffer = 0;
644 return 0;
645 }
646 atari_scsi_host = instance;
647 /*
648 * Set irq to 0, to avoid that the mid-level code disables our interrupt
649 * during queue_command calls. This is completely unnecessary, and even
650 * worse causes bad problems on the Falcon, where the int is shared with
651 * IDE and floppy!
652 */
653 instance->irq = 0;
654
655 #ifdef CONFIG_ATARI_SCSI_RESET_BOOT
656 atari_scsi_reset_boot();
657 #endif
658 NCR5380_init(instance, 0);
659
660 if (IS_A_TT()) {
661
662 /* This int is actually "pseudo-slow", i.e. it acts like a slow
663 * interrupt after having cleared the pending flag for the DMA
664 * interrupt. */
665 if (request_irq(IRQ_TT_MFP_SCSI, scsi_tt_intr, IRQ_TYPE_SLOW,
666 "SCSI NCR5380", instance)) {
667 printk(KERN_ERR "atari_scsi_detect: cannot allocate irq %d, aborting",IRQ_TT_MFP_SCSI);
668 scsi_unregister(atari_scsi_host);
669 atari_stram_free(atari_dma_buffer);
670 atari_dma_buffer = 0;
671 return 0;
672 }
673 tt_mfp.active_edge |= 0x80; /* SCSI int on L->H */
674 #ifdef REAL_DMA
675 tt_scsi_dma.dma_ctrl = 0;
676 atari_dma_residual = 0;
677
678 if (MACH_IS_MEDUSA) {
679 /* While the read overruns (described by Drew Eckhardt in
680 * NCR5380.c) never happened on TTs, they do in fact on the Medusa
681 * (This was the cause why SCSI didn't work right for so long
682 * there.) Since handling the overruns slows down a bit, I turned
683 * the #ifdef's into a runtime condition.
684 *
685 * In principle it should be sufficient to do max. 1 byte with
686 * PIO, but there is another problem on the Medusa with the DMA
687 * rest data register. So 'atari_read_overruns' is currently set
688 * to 4 to avoid having transfers that aren't a multiple of 4. If
689 * the rest data bug is fixed, this can be lowered to 1.
690 */
691 atari_read_overruns = 4;
692 }
693 #endif /*REAL_DMA*/
694 } else { /* ! IS_A_TT */
695
696 /* Nothing to do for the interrupt: the ST-DMA is initialized
697 * already by atari_init_INTS()
698 */
699
700 #ifdef REAL_DMA
701 atari_dma_residual = 0;
702 atari_dma_active = 0;
703 atari_dma_stram_mask = (ATARIHW_PRESENT(EXTD_DMA) ? 0x00000000
704 : 0xff000000);
705 #endif
706 }
707
708 printk(KERN_INFO "scsi%d: options CAN_QUEUE=%d CMD_PER_LUN=%d SCAT-GAT=%d "
709 #ifdef SUPPORT_TAGS
710 "TAGGED-QUEUING=%s "
711 #endif
712 "HOSTID=%d",
713 instance->host_no, instance->hostt->can_queue,
714 instance->hostt->cmd_per_lun,
715 instance->hostt->sg_tablesize,
716 #ifdef SUPPORT_TAGS
717 setup_use_tagged_queuing ? "yes" : "no",
718 #endif
719 instance->hostt->this_id );
720 NCR5380_print_options(instance);
721 printk("\n");
722
723 called = 1;
724 return 1;
725 }
726
atari_scsi_release(struct Scsi_Host * sh)727 int atari_scsi_release(struct Scsi_Host *sh)
728 {
729 if (IS_A_TT())
730 free_irq(IRQ_TT_MFP_SCSI, sh);
731 if (atari_dma_buffer)
732 atari_stram_free(atari_dma_buffer);
733 NCR5380_exit(sh);
734 return 1;
735 }
736
atari_scsi_setup(char * str,int * ints)737 void __init atari_scsi_setup(char *str, int *ints)
738 {
739 /* Format of atascsi parameter is:
740 * atascsi=<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
741 * Defaults depend on TT or Falcon, hostid determined at run time.
742 * Negative values mean don't change.
743 */
744
745 if (ints[0] < 1) {
746 printk("atari_scsi_setup: no arguments!\n");
747 return;
748 }
749
750 if (ints[0] >= 1) {
751 if (ints[1] > 0)
752 /* no limits on this, just > 0 */
753 setup_can_queue = ints[1];
754 }
755 if (ints[0] >= 2) {
756 if (ints[2] > 0)
757 setup_cmd_per_lun = ints[2];
758 }
759 if (ints[0] >= 3) {
760 if (ints[3] >= 0) {
761 setup_sg_tablesize = ints[3];
762 /* Must be <= SG_ALL (255) */
763 if (setup_sg_tablesize > SG_ALL)
764 setup_sg_tablesize = SG_ALL;
765 }
766 }
767 if (ints[0] >= 4) {
768 /* Must be between 0 and 7 */
769 if (ints[4] >= 0 && ints[4] <= 7)
770 setup_hostid = ints[4];
771 else if (ints[4] > 7)
772 printk("atari_scsi_setup: invalid host ID %d !\n", ints[4]);
773 }
774 #ifdef SUPPORT_TAGS
775 if (ints[0] >= 5) {
776 if (ints[5] >= 0)
777 setup_use_tagged_queuing = !!ints[5];
778 }
779 #endif
780 }
781
atari_scsi_bus_reset(Scsi_Cmnd * cmd)782 int atari_scsi_bus_reset(Scsi_Cmnd *cmd)
783 {
784 int rv;
785 struct NCR5380_hostdata *hostdata =
786 (struct NCR5380_hostdata *)cmd->device->host->hostdata;
787
788 /* For doing the reset, SCSI interrupts must be disabled first,
789 * since the 5380 raises its IRQ line while _RST is active and we
790 * can't disable interrupts completely, since we need the timer.
791 */
792 /* And abort a maybe active DMA transfer */
793 if (IS_A_TT()) {
794 atari_turnoff_irq(IRQ_TT_MFP_SCSI);
795 #ifdef REAL_DMA
796 tt_scsi_dma.dma_ctrl = 0;
797 #endif /* REAL_DMA */
798 } else {
799 atari_turnoff_irq(IRQ_MFP_FSCSI);
800 #ifdef REAL_DMA
801 st_dma.dma_mode_status = 0x90;
802 atari_dma_active = 0;
803 atari_dma_orig_addr = NULL;
804 #endif /* REAL_DMA */
805 }
806
807 rv = NCR5380_bus_reset(cmd);
808
809 /* Re-enable ints */
810 if (IS_A_TT()) {
811 atari_turnon_irq(IRQ_TT_MFP_SCSI);
812 } else {
813 atari_turnon_irq(IRQ_MFP_FSCSI);
814 }
815 if ((rv & SCSI_RESET_ACTION) == SCSI_RESET_SUCCESS)
816 falcon_release_lock_if_possible(hostdata);
817
818 return rv;
819 }
820
821
822 #ifdef CONFIG_ATARI_SCSI_RESET_BOOT
atari_scsi_reset_boot(void)823 static void __init atari_scsi_reset_boot(void)
824 {
825 unsigned long end;
826
827 /*
828 * Do a SCSI reset to clean up the bus during initialization. No messing
829 * with the queues, interrupts, or locks necessary here.
830 */
831
832 printk("Atari SCSI: resetting the SCSI bus...");
833
834 /* get in phase */
835 NCR5380_write(TARGET_COMMAND_REG,
836 PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG)));
837
838 /* assert RST */
839 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
840 /* The min. reset hold time is 25us, so 40us should be enough */
841 udelay(50);
842 /* reset RST and interrupt */
843 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
844 NCR5380_read(RESET_PARITY_INTERRUPT_REG);
845
846 end = jiffies + AFTER_RESET_DELAY;
847 while (time_before(jiffies, end))
848 barrier();
849
850 printk(" done\n");
851 }
852 #endif
853
854
atari_scsi_info(struct Scsi_Host * host)855 const char *atari_scsi_info(struct Scsi_Host *host)
856 {
857 /* atari_scsi_detect() is verbose enough... */
858 static const char string[] = "Atari native SCSI";
859 return string;
860 }
861
862
863 #if defined(REAL_DMA)
864
atari_scsi_dma_setup(struct Scsi_Host * instance,void * data,unsigned long count,int dir)865 unsigned long atari_scsi_dma_setup(struct Scsi_Host *instance, void *data,
866 unsigned long count, int dir)
867 {
868 unsigned long addr = virt_to_phys(data);
869
870 DMA_PRINTK("scsi%d: setting up dma, data = %p, phys = %lx, count = %ld, "
871 "dir = %d\n", instance->host_no, data, addr, count, dir);
872
873 if (!IS_A_TT() && !STRAM_ADDR(addr)) {
874 /* If we have a non-DMAable address on a Falcon, use the dribble
875 * buffer; 'orig_addr' != 0 in the read case tells the interrupt
876 * handler to copy data from the dribble buffer to the originally
877 * wanted address.
878 */
879 if (dir)
880 memcpy(atari_dma_buffer, data, count);
881 else
882 atari_dma_orig_addr = data;
883 addr = atari_dma_phys_buffer;
884 }
885
886 atari_dma_startaddr = addr; /* Needed for calculating residual later. */
887
888 /* Cache cleanup stuff: On writes, push any dirty cache out before sending
889 * it to the peripheral. (Must be done before DMA setup, since at least
890 * the ST-DMA begins to fill internal buffers right after setup. For
891 * reads, invalidate any cache, may be altered after DMA without CPU
892 * knowledge.
893 *
894 * ++roman: For the Medusa, there's no need at all for that cache stuff,
895 * because the hardware does bus snooping (fine!).
896 */
897 dma_cache_maintenance(addr, count, dir);
898
899 if (count == 0)
900 printk(KERN_NOTICE "SCSI warning: DMA programmed for 0 bytes !\n");
901
902 if (IS_A_TT()) {
903 tt_scsi_dma.dma_ctrl = dir;
904 SCSI_DMA_WRITE_P(dma_addr, addr);
905 SCSI_DMA_WRITE_P(dma_cnt, count);
906 tt_scsi_dma.dma_ctrl = dir | 2;
907 } else { /* ! IS_A_TT */
908
909 /* set address */
910 SCSI_DMA_SETADR(addr);
911
912 /* toggle direction bit to clear FIFO and set DMA direction */
913 dir <<= 8;
914 st_dma.dma_mode_status = 0x90 | dir;
915 st_dma.dma_mode_status = 0x90 | (dir ^ 0x100);
916 st_dma.dma_mode_status = 0x90 | dir;
917 udelay(40);
918 /* On writes, round up the transfer length to the next multiple of 512
919 * (see also comment at atari_dma_xfer_len()). */
920 st_dma.fdc_acces_seccount = (count + (dir ? 511 : 0)) >> 9;
921 udelay(40);
922 st_dma.dma_mode_status = 0x10 | dir;
923 udelay(40);
924 /* need not restore value of dir, only boolean value is tested */
925 atari_dma_active = 1;
926 }
927
928 return count;
929 }
930
931
atari_scsi_dma_residual(struct Scsi_Host * instance)932 static long atari_scsi_dma_residual(struct Scsi_Host *instance)
933 {
934 return atari_dma_residual;
935 }
936
937
938 #define CMD_SURELY_BLOCK_MODE 0
939 #define CMD_SURELY_BYTE_MODE 1
940 #define CMD_MODE_UNKNOWN 2
941
falcon_classify_cmd(Scsi_Cmnd * cmd)942 static int falcon_classify_cmd(Scsi_Cmnd *cmd)
943 {
944 unsigned char opcode = cmd->cmnd[0];
945
946 if (opcode == READ_DEFECT_DATA || opcode == READ_LONG ||
947 opcode == READ_BUFFER)
948 return CMD_SURELY_BYTE_MODE;
949 else if (opcode == READ_6 || opcode == READ_10 ||
950 opcode == 0xa8 /* READ_12 */ || opcode == READ_REVERSE ||
951 opcode == RECOVER_BUFFERED_DATA) {
952 /* In case of a sequential-access target (tape), special care is
953 * needed here: The transfer is block-mode only if the 'fixed' bit is
954 * set! */
955 if (cmd->device->type == TYPE_TAPE && !(cmd->cmnd[1] & 1))
956 return CMD_SURELY_BYTE_MODE;
957 else
958 return CMD_SURELY_BLOCK_MODE;
959 } else
960 return CMD_MODE_UNKNOWN;
961 }
962
963
964 /* This function calculates the number of bytes that can be transferred via
965 * DMA. On the TT, this is arbitrary, but on the Falcon we have to use the
966 * ST-DMA chip. There are only multiples of 512 bytes possible and max.
967 * 255*512 bytes :-( This means also, that defining READ_OVERRUNS is not
968 * possible on the Falcon, since that would require to program the DMA for
969 * n*512 - atari_read_overrun bytes. But it seems that the Falcon doesn't have
970 * the overrun problem, so this question is academic :-)
971 */
972
atari_dma_xfer_len(unsigned long wanted_len,Scsi_Cmnd * cmd,int write_flag)973 static unsigned long atari_dma_xfer_len(unsigned long wanted_len,
974 Scsi_Cmnd *cmd, int write_flag)
975 {
976 unsigned long possible_len, limit;
977
978 if (IS_A_TT())
979 /* TT SCSI DMA can transfer arbitrary #bytes */
980 return wanted_len;
981
982 /* ST DMA chip is stupid -- only multiples of 512 bytes! (and max.
983 * 255*512 bytes, but this should be enough)
984 *
985 * ++roman: Aaargl! Another Falcon-SCSI problem... There are some commands
986 * that return a number of bytes which cannot be known beforehand. In this
987 * case, the given transfer length is an "allocation length". Now it
988 * can happen that this allocation length is a multiple of 512 bytes and
989 * the DMA is used. But if not n*512 bytes really arrive, some input data
990 * will be lost in the ST-DMA's FIFO :-( Thus, we have to distinguish
991 * between commands that do block transfers and those that do byte
992 * transfers. But this isn't easy... there are lots of vendor specific
993 * commands, and the user can issue any command via the
994 * SCSI_IOCTL_SEND_COMMAND.
995 *
996 * The solution: We classify SCSI commands in 1) surely block-mode cmd.s,
997 * 2) surely byte-mode cmd.s and 3) cmd.s with unknown mode. In case 1)
998 * and 3), the thing to do is obvious: allow any number of blocks via DMA
999 * or none. In case 2), we apply some heuristic: Byte mode is assumed if
1000 * the transfer (allocation) length is < 1024, hoping that no cmd. not
1001 * explicitly known as byte mode have such big allocation lengths...
1002 * BTW, all the discussion above applies only to reads. DMA writes are
1003 * unproblematic anyways, since the targets aborts the transfer after
1004 * receiving a sufficient number of bytes.
1005 *
1006 * Another point: If the transfer is from/to an non-ST-RAM address, we
1007 * use the dribble buffer and thus can do only STRAM_BUFFER_SIZE bytes.
1008 */
1009
1010 if (write_flag) {
1011 /* Write operation can always use the DMA, but the transfer size must
1012 * be rounded up to the next multiple of 512 (atari_dma_setup() does
1013 * this).
1014 */
1015 possible_len = wanted_len;
1016 } else {
1017 /* Read operations: if the wanted transfer length is not a multiple of
1018 * 512, we cannot use DMA, since the ST-DMA cannot split transfers
1019 * (no interrupt on DMA finished!)
1020 */
1021 if (wanted_len & 0x1ff)
1022 possible_len = 0;
1023 else {
1024 /* Now classify the command (see above) and decide whether it is
1025 * allowed to do DMA at all */
1026 switch (falcon_classify_cmd(cmd)) {
1027 case CMD_SURELY_BLOCK_MODE:
1028 possible_len = wanted_len;
1029 break;
1030 case CMD_SURELY_BYTE_MODE:
1031 possible_len = 0; /* DMA prohibited */
1032 break;
1033 case CMD_MODE_UNKNOWN:
1034 default:
1035 /* For unknown commands assume block transfers if the transfer
1036 * size/allocation length is >= 1024 */
1037 possible_len = (wanted_len < 1024) ? 0 : wanted_len;
1038 break;
1039 }
1040 }
1041 }
1042
1043 /* Last step: apply the hard limit on DMA transfers */
1044 limit = (atari_dma_buffer && !STRAM_ADDR(virt_to_phys(cmd->SCp.ptr))) ?
1045 STRAM_BUFFER_SIZE : 255*512;
1046 if (possible_len > limit)
1047 possible_len = limit;
1048
1049 if (possible_len != wanted_len)
1050 DMA_PRINTK("Sorry, must cut DMA transfer size to %ld bytes "
1051 "instead of %ld\n", possible_len, wanted_len);
1052
1053 return possible_len;
1054 }
1055
1056
1057 #endif /* REAL_DMA */
1058
1059
1060 /* NCR5380 register access functions
1061 *
1062 * There are separate functions for TT and Falcon, because the access
1063 * methods are quite different. The calling macros NCR5380_read and
1064 * NCR5380_write call these functions via function pointers.
1065 */
1066
atari_scsi_tt_reg_read(unsigned char reg)1067 static unsigned char atari_scsi_tt_reg_read(unsigned char reg)
1068 {
1069 return tt_scsi_regp[reg * 2];
1070 }
1071
atari_scsi_tt_reg_write(unsigned char reg,unsigned char value)1072 static void atari_scsi_tt_reg_write(unsigned char reg, unsigned char value)
1073 {
1074 tt_scsi_regp[reg * 2] = value;
1075 }
1076
atari_scsi_falcon_reg_read(unsigned char reg)1077 static unsigned char atari_scsi_falcon_reg_read(unsigned char reg)
1078 {
1079 dma_wd.dma_mode_status= (u_short)(0x88 + reg);
1080 return (u_char)dma_wd.fdc_acces_seccount;
1081 }
1082
atari_scsi_falcon_reg_write(unsigned char reg,unsigned char value)1083 static void atari_scsi_falcon_reg_write(unsigned char reg, unsigned char value)
1084 {
1085 dma_wd.dma_mode_status = (u_short)(0x88 + reg);
1086 dma_wd.fdc_acces_seccount = (u_short)value;
1087 }
1088
1089
1090 #include "atari_NCR5380.c"
1091
1092 static struct scsi_host_template driver_template = {
1093 .proc_info = atari_scsi_proc_info,
1094 .name = "Atari native SCSI",
1095 .detect = atari_scsi_detect,
1096 .release = atari_scsi_release,
1097 .info = atari_scsi_info,
1098 .queuecommand = atari_scsi_queue_command,
1099 .eh_abort_handler = atari_scsi_abort,
1100 .eh_bus_reset_handler = atari_scsi_bus_reset,
1101 .can_queue = 0, /* initialized at run-time */
1102 .this_id = 0, /* initialized at run-time */
1103 .sg_tablesize = 0, /* initialized at run-time */
1104 .cmd_per_lun = 0, /* initialized at run-time */
1105 .use_clustering = DISABLE_CLUSTERING
1106 };
1107
1108
1109 #include "scsi_module.c"
1110
1111 MODULE_LICENSE("GPL");
1112