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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#include <linux/wait.h>
94
95#include <asm/setup.h>
96#include <asm/atarihw.h>
97#include <asm/atariints.h>
98#include <asm/page.h>
99#include <asm/pgtable.h>
100#include <asm/irq.h>
101#include <asm/traps.h>
102
103#include "scsi.h"
104#include <scsi/scsi_host.h>
105#include "atari_scsi.h"
106#include "NCR5380.h"
107#include <asm/atari_stdma.h>
108#include <asm/atari_stram.h>
109#include <asm/io.h>
110
111#include <linux/stat.h>
112
113#define IS_A_TT() ATARIHW_PRESENT(TT_SCSI)
114
115#define SCSI_DMA_WRITE_P(elt,val) \
116 do { \
117 unsigned long v = val; \
118 tt_scsi_dma.elt##_lo = v & 0xff; \
119 v >>= 8; \
120 tt_scsi_dma.elt##_lmd = v & 0xff; \
121 v >>= 8; \
122 tt_scsi_dma.elt##_hmd = v & 0xff; \
123 v >>= 8; \
124 tt_scsi_dma.elt##_hi = v & 0xff; \
125 } while(0)
126
127#define SCSI_DMA_READ_P(elt) \
128 (((((((unsigned long)tt_scsi_dma.elt##_hi << 8) | \
129 (unsigned long)tt_scsi_dma.elt##_hmd) << 8) | \
130 (unsigned long)tt_scsi_dma.elt##_lmd) << 8) | \
131 (unsigned long)tt_scsi_dma.elt##_lo)
132
133
134static inline void SCSI_DMA_SETADR(unsigned long adr)
135{
136 st_dma.dma_lo = (unsigned char)adr;
137 MFPDELAY();
138 adr >>= 8;
139 st_dma.dma_md = (unsigned char)adr;
140 MFPDELAY();
141 adr >>= 8;
142 st_dma.dma_hi = (unsigned char)adr;
143 MFPDELAY();
144}
145
146static inline unsigned long SCSI_DMA_GETADR(void)
147{
148 unsigned long adr;
149 adr = st_dma.dma_lo;
150 MFPDELAY();
151 adr |= (st_dma.dma_md & 0xff) << 8;
152 MFPDELAY();
153 adr |= (st_dma.dma_hi & 0xff) << 16;
154 MFPDELAY();
155 return adr;
156}
157
158static inline void ENABLE_IRQ(void)
159{
160 if (IS_A_TT())
161 atari_enable_irq(IRQ_TT_MFP_SCSI);
162 else
163 atari_enable_irq(IRQ_MFP_FSCSI);
164}
165
166static inline void DISABLE_IRQ(void)
167{
168 if (IS_A_TT())
169 atari_disable_irq(IRQ_TT_MFP_SCSI);
170 else
171 atari_disable_irq(IRQ_MFP_FSCSI);
172}
173
174
175#define HOSTDATA_DMALEN (((struct NCR5380_hostdata *) \
176 (atari_scsi_host->hostdata))->dma_len)
177
178/* Time (in jiffies) to wait after a reset; the SCSI standard calls for 250ms,
179 * we usually do 0.5s to be on the safe side. But Toshiba CD-ROMs once more
180 * need ten times the standard value... */
181#ifndef CONFIG_ATARI_SCSI_TOSHIBA_DELAY
182#define AFTER_RESET_DELAY (HZ/2)
183#else
184#define AFTER_RESET_DELAY (5*HZ/2)
185#endif
186
187/***************************** Prototypes *****************************/
188
189#ifdef REAL_DMA
190static int scsi_dma_is_ignored_buserr(unsigned char dma_stat);
191static void atari_scsi_fetch_restbytes(void);
192static long atari_scsi_dma_residual(struct Scsi_Host *instance);
193static int falcon_classify_cmd(Scsi_Cmnd *cmd);
194static unsigned long atari_dma_xfer_len(unsigned long wanted_len,
195 Scsi_Cmnd *cmd, int write_flag);
196#endif
197static irqreturn_t scsi_tt_intr(int irq, void *dummy);
198static irqreturn_t scsi_falcon_intr(int irq, void *dummy);
199static void falcon_release_lock_if_possible(struct NCR5380_hostdata *hostdata);
200static void falcon_get_lock(void);
201#ifdef CONFIG_ATARI_SCSI_RESET_BOOT
202static void atari_scsi_reset_boot(void);
203#endif
204static unsigned char atari_scsi_tt_reg_read(unsigned char reg);
205static void atari_scsi_tt_reg_write(unsigned char reg, unsigned char value);
206static unsigned char atari_scsi_falcon_reg_read(unsigned char reg);
207static void atari_scsi_falcon_reg_write(unsigned char reg, unsigned char value);
208
209/************************* End of Prototypes **************************/
210
211
212static struct Scsi_Host *atari_scsi_host;
213static unsigned char (*atari_scsi_reg_read)(unsigned char reg);
214static void (*atari_scsi_reg_write)(unsigned char reg, unsigned char value);
215
216#ifdef REAL_DMA
217static unsigned long atari_dma_residual, atari_dma_startaddr;
218static short atari_dma_active;
219/* pointer to the dribble buffer */
220static char *atari_dma_buffer;
221/* precalculated physical address of the dribble buffer */
222static unsigned long atari_dma_phys_buffer;
223/* != 0 tells the Falcon int handler to copy data from the dribble buffer */
224static char *atari_dma_orig_addr;
225/* size of the dribble buffer; 4k seems enough, since the Falcon cannot use
226 * scatter-gather anyway, so most transfers are 1024 byte only. In the rare
227 * cases where requests to physical contiguous buffers have been merged, this
228 * request is <= 4k (one page). So I don't think we have to split transfers
229 * just due to this buffer size...
230 */
231#define STRAM_BUFFER_SIZE (4096)
232/* mask for address bits that can't be used with the ST-DMA */
233static unsigned long atari_dma_stram_mask;
234#define STRAM_ADDR(a) (((a) & atari_dma_stram_mask) == 0)
235/* number of bytes to cut from a transfer to handle NCR overruns */
236static int atari_read_overruns;
237#endif
238
239static int setup_can_queue = -1;
240module_param(setup_can_queue, int, 0);
241static int setup_cmd_per_lun = -1;
242module_param(setup_cmd_per_lun, int, 0);
243static int setup_sg_tablesize = -1;
244module_param(setup_sg_tablesize, int, 0);
245#ifdef SUPPORT_TAGS
246static int setup_use_tagged_queuing = -1;
247module_param(setup_use_tagged_queuing, int, 0);
248#endif
249static int setup_hostid = -1;
250module_param(setup_hostid, int, 0);
251
252
253#if defined(REAL_DMA)
254
255static int scsi_dma_is_ignored_buserr(unsigned char dma_stat)
256{
257 int i;
258 unsigned long addr = SCSI_DMA_READ_P(dma_addr), end_addr;
259
260 if (dma_stat & 0x01) {
261
262 /* A bus error happens when DMA-ing from the last page of a
263 * physical memory chunk (DMA prefetch!), but that doesn't hurt.
264 * Check for this case:
265 */
266
267 for (i = 0; i < m68k_num_memory; ++i) {
268 end_addr = m68k_memory[i].addr + m68k_memory[i].size;
269 if (end_addr <= addr && addr <= end_addr + 4)
270 return 1;
271 }
272 }
273 return 0;
274}
275
276
277#if 0
278/* Dead code... wasn't called anyway :-) and causes some trouble, because at
279 * end-of-DMA, both SCSI ints are triggered simultaneously, so the NCR int has
280 * to clear the DMA int pending bit before it allows other level 6 interrupts.
281 */
282static void scsi_dma_buserr(int irq, void *dummy)
283{
284 unsigned char dma_stat = tt_scsi_dma.dma_ctrl;
285
286 /* Don't do anything if a NCR interrupt is pending. Probably it's just
287 * masked... */
288 if (atari_irq_pending(IRQ_TT_MFP_SCSI))
289 return;
290
291 printk("Bad SCSI DMA interrupt! dma_addr=0x%08lx dma_stat=%02x dma_cnt=%08lx\n",
292 SCSI_DMA_READ_P(dma_addr), dma_stat, SCSI_DMA_READ_P(dma_cnt));
293 if (dma_stat & 0x80) {
294 if (!scsi_dma_is_ignored_buserr(dma_stat))
295 printk("SCSI DMA bus error -- bad DMA programming!\n");
296 } else {
297 /* Under normal circumstances we never should get to this point,
298 * since both interrupts are triggered simultaneously and the 5380
299 * int has higher priority. When this irq is handled, that DMA
300 * interrupt is cleared. So a warning message is printed here.
301 */
302 printk("SCSI DMA intr ?? -- this shouldn't happen!\n");
303 }
304}
305#endif
306
307#endif
308
309
310static irqreturn_t scsi_tt_intr(int irq, void *dummy)
311{
312#ifdef REAL_DMA
313 int dma_stat;
314
315 dma_stat = tt_scsi_dma.dma_ctrl;
316
317 INT_PRINTK("scsi%d: NCR5380 interrupt, DMA status = %02x\n",
318 atari_scsi_host->host_no, dma_stat & 0xff);
319
320 /* Look if it was the DMA that has interrupted: First possibility
321 * is that a bus error occurred...
322 */
323 if (dma_stat & 0x80) {
324 if (!scsi_dma_is_ignored_buserr(dma_stat)) {
325 printk(KERN_ERR "SCSI DMA caused bus error near 0x%08lx\n",
326 SCSI_DMA_READ_P(dma_addr));
327 printk(KERN_CRIT "SCSI DMA bus error -- bad DMA programming!");
328 }
329 }
330
331 /* If the DMA is active but not finished, we have the case
332 * that some other 5380 interrupt occurred within the DMA transfer.
333 * This means we have residual bytes, if the desired end address
334 * is not yet reached. Maybe we have to fetch some bytes from the
335 * rest data register, too. The residual must be calculated from
336 * the address pointer, not the counter register, because only the
337 * addr reg counts bytes not yet written and pending in the rest
338 * data reg!
339 */
340 if ((dma_stat & 0x02) && !(dma_stat & 0x40)) {
341 atari_dma_residual = HOSTDATA_DMALEN - (SCSI_DMA_READ_P(dma_addr) - atari_dma_startaddr);
342
343 DMA_PRINTK("SCSI DMA: There are %ld residual bytes.\n",
344 atari_dma_residual);
345
346 if ((signed int)atari_dma_residual < 0)
347 atari_dma_residual = 0;
348 if ((dma_stat & 1) == 0) {
349 /*
350 * After read operations, we maybe have to
351 * transport some rest bytes
352 */
353 atari_scsi_fetch_restbytes();
354 } else {
355 /*
356 * There seems to be a nasty bug in some SCSI-DMA/NCR
357 * combinations: If a target disconnects while a write
358 * operation is going on, the address register of the
359 * DMA may be a few bytes farer than it actually read.
360 * This is probably due to DMA prefetching and a delay
361 * between DMA and NCR. Experiments showed that the
362 * dma_addr is 9 bytes to high, but this could vary.
363 * The problem is, that the residual is thus calculated
364 * wrong and the next transfer will start behind where
365 * it should. So we round up the residual to the next
366 * multiple of a sector size, if it isn't already a
367 * multiple and the originally expected transfer size
368 * was. The latter condition is there to ensure that
369 * the correction is taken only for "real" data
370 * transfers and not for, e.g., the parameters of some
371 * other command. These shouldn't disconnect anyway.
372 */
373 if (atari_dma_residual & 0x1ff) {
374 DMA_PRINTK("SCSI DMA: DMA bug corrected, "
375 "difference %ld bytes\n",
376 512 - (atari_dma_residual & 0x1ff));
377 atari_dma_residual = (atari_dma_residual + 511) & ~0x1ff;
378 }
379 }
380 tt_scsi_dma.dma_ctrl = 0;
381 }
382
383 /* If the DMA is finished, fetch the rest bytes and turn it off */
384 if (dma_stat & 0x40) {
385 atari_dma_residual = 0;
386 if ((dma_stat & 1) == 0)
387 atari_scsi_fetch_restbytes();
388 tt_scsi_dma.dma_ctrl = 0;
389 }
390
391#endif /* REAL_DMA */
392
393 NCR5380_intr(irq, dummy);
394
395#if 0
396 /* To be sure the int is not masked */
397 atari_enable_irq(IRQ_TT_MFP_SCSI);
398#endif
399 return IRQ_HANDLED;
400}
401
402
403static irqreturn_t scsi_falcon_intr(int irq, void *dummy)
404{
405#ifdef REAL_DMA
406 int dma_stat;
407
408 /* Turn off DMA and select sector counter register before
409 * accessing the status register (Atari recommendation!)
410 */
411 st_dma.dma_mode_status = 0x90;
412 dma_stat = st_dma.dma_mode_status;
413
414 /* Bit 0 indicates some error in the DMA process... don't know
415 * what happened exactly (no further docu).
416 */
417 if (!(dma_stat & 0x01)) {
418 /* DMA error */
419 printk(KERN_CRIT "SCSI DMA error near 0x%08lx!\n", SCSI_DMA_GETADR());
420 }
421
422 /* If the DMA was active, but now bit 1 is not clear, it is some
423 * other 5380 interrupt that finishes the DMA transfer. We have to
424 * calculate the number of residual bytes and give a warning if
425 * bytes are stuck in the ST-DMA fifo (there's no way to reach them!)
426 */
427 if (atari_dma_active && (dma_stat & 0x02)) {
428 unsigned long transferred;
429
430 transferred = SCSI_DMA_GETADR() - atari_dma_startaddr;
431 /* The ST-DMA address is incremented in 2-byte steps, but the
432 * data are written only in 16-byte chunks. If the number of
433 * transferred bytes is not divisible by 16, the remainder is
434 * lost somewhere in outer space.
435 */
436 if (transferred & 15)
437 printk(KERN_ERR "SCSI DMA error: %ld bytes lost in "
438 "ST-DMA fifo\n", transferred & 15);
439
440 atari_dma_residual = HOSTDATA_DMALEN - transferred;
441 DMA_PRINTK("SCSI DMA: There are %ld residual bytes.\n",
442 atari_dma_residual);
443 } else
444 atari_dma_residual = 0;
445 atari_dma_active = 0;
446
447 if (atari_dma_orig_addr) {
448 /* If the dribble buffer was used on a read operation, copy the DMA-ed
449 * data to the original destination address.
450 */
451 memcpy(atari_dma_orig_addr, phys_to_virt(atari_dma_startaddr),
452 HOSTDATA_DMALEN - atari_dma_residual);
453 atari_dma_orig_addr = NULL;
454 }
455
456#endif /* REAL_DMA */
457
458 NCR5380_intr(irq, dummy);
459 return IRQ_HANDLED;
460}
461
462
463#ifdef REAL_DMA
464static void atari_scsi_fetch_restbytes(void)
465{
466 int nr;
467 char *src, *dst;
468 unsigned long phys_dst;
469
470 /* fetch rest bytes in the DMA register */
471 phys_dst = SCSI_DMA_READ_P(dma_addr);
472 nr = phys_dst & 3;
473 if (nr) {
474 /* there are 'nr' bytes left for the last long address
475 before the DMA pointer */
476 phys_dst ^= nr;
477 DMA_PRINTK("SCSI DMA: there are %d rest bytes for phys addr 0x%08lx",
478 nr, phys_dst);
479 /* The content of the DMA pointer is a physical address! */
480 dst = phys_to_virt(phys_dst);
481 DMA_PRINTK(" = virt addr %p\n", dst);
482 for (src = (char *)&tt_scsi_dma.dma_restdata; nr != 0; --nr)
483 *dst++ = *src++;
484 }
485}
486#endif /* REAL_DMA */
487
488
489static int falcon_got_lock = 0;
490static DECLARE_WAIT_QUEUE_HEAD(falcon_fairness_wait);
491static int falcon_trying_lock = 0;
492static DECLARE_WAIT_QUEUE_HEAD(falcon_try_wait);
493static int falcon_dont_release = 0;
494
495/* This function releases the lock on the DMA chip if there is no
496 * connected command and the disconnected queue is empty. On
497 * releasing, instances of falcon_get_lock are awoken, that put
498 * themselves to sleep for fairness. They can now try to get the lock
499 * again (but others waiting longer more probably will win).
500 */
501
502static void falcon_release_lock_if_possible(struct NCR5380_hostdata *hostdata)
503{
504 unsigned long flags;
505
506 if (IS_A_TT())
507 return;
508
509 local_irq_save(flags);
510
511 if (falcon_got_lock && !hostdata->disconnected_queue &&
512 !hostdata->issue_queue && !hostdata->connected) {
513
514 if (falcon_dont_release) {
515#if 0
516 printk("WARNING: Lock release not allowed. Ignored\n");
517#endif
518 local_irq_restore(flags);
519 return;
520 }
521 falcon_got_lock = 0;
522 stdma_release();
523 wake_up(&falcon_fairness_wait);
524 }
525
526 local_irq_restore(flags);
527}
528
529/* This function manages the locking of the ST-DMA.
530 * If the DMA isn't locked already for SCSI, it tries to lock it by
531 * calling stdma_lock(). But if the DMA is locked by the SCSI code and
532 * there are other drivers waiting for the chip, we do not issue the
533 * command immediately but wait on 'falcon_fairness_queue'. We will be
534 * waked up when the DMA is unlocked by some SCSI interrupt. After that
535 * we try to get the lock again.
536 * But we must be prepared that more than one instance of
537 * falcon_get_lock() is waiting on the fairness queue. They should not
538 * try all at once to call stdma_lock(), one is enough! For that, the
539 * first one sets 'falcon_trying_lock', others that see that variable
540 * set wait on the queue 'falcon_try_wait'.
541 * Complicated, complicated.... Sigh...
542 */
543
544static void falcon_get_lock(void)
545{
546 unsigned long flags;
547
548 if (IS_A_TT())
549 return;
550
551 local_irq_save(flags);
552
553 wait_event_cmd(falcon_fairness_wait,
554 in_interrupt() || !falcon_got_lock || !stdma_others_waiting(),
555 local_irq_restore(flags),
556 local_irq_save(flags));
557
558 while (!falcon_got_lock) {
559 if (in_irq())
560 panic("Falcon SCSI hasn't ST-DMA lock in interrupt");
561 if (!falcon_trying_lock) {
562 falcon_trying_lock = 1;
563 stdma_lock(scsi_falcon_intr, NULL);
564 falcon_got_lock = 1;
565 falcon_trying_lock = 0;
566 wake_up(&falcon_try_wait);
567 } else {
568 wait_event_cmd(falcon_try_wait,
569 falcon_got_lock && !falcon_trying_lock,
570 local_irq_restore(flags),
571 local_irq_save(flags));
572 }
573 }
574
575 local_irq_restore(flags);
576 if (!falcon_got_lock)
577 panic("Falcon SCSI: someone stole the lock :-(\n");
578}
579
580
581static int __init atari_scsi_detect(struct scsi_host_template *host)
582{
583 static int called = 0;
584 struct Scsi_Host *instance;
585
586 if (!MACH_IS_ATARI ||
587 (!ATARIHW_PRESENT(ST_SCSI) && !ATARIHW_PRESENT(TT_SCSI)) ||
588 called)
589 return 0;
590
591 host->proc_name = "Atari";
592
593 atari_scsi_reg_read = IS_A_TT() ? atari_scsi_tt_reg_read :
594 atari_scsi_falcon_reg_read;
595 atari_scsi_reg_write = IS_A_TT() ? atari_scsi_tt_reg_write :
596 atari_scsi_falcon_reg_write;
597
598 /* setup variables */
599 host->can_queue =
600 (setup_can_queue > 0) ? setup_can_queue :
601 IS_A_TT() ? ATARI_TT_CAN_QUEUE : ATARI_FALCON_CAN_QUEUE;
602 host->cmd_per_lun =
603 (setup_cmd_per_lun > 0) ? setup_cmd_per_lun :
604 IS_A_TT() ? ATARI_TT_CMD_PER_LUN : ATARI_FALCON_CMD_PER_LUN;
605 /* Force sg_tablesize to 0 on a Falcon! */
606 host->sg_tablesize =
607 !IS_A_TT() ? ATARI_FALCON_SG_TABLESIZE :
608 (setup_sg_tablesize >= 0) ? setup_sg_tablesize : ATARI_TT_SG_TABLESIZE;
609
610 if (setup_hostid >= 0)
611 host->this_id = setup_hostid;
612 else {
613 /* use 7 as default */
614 host->this_id = 7;
615 /* Test if a host id is set in the NVRam */
616 if (ATARIHW_PRESENT(TT_CLK) && nvram_check_checksum()) {
617 unsigned char b = nvram_read_byte( 14 );
618 /* Arbitration enabled? (for TOS) If yes, use configured host ID */
619 if (b & 0x80)
620 host->this_id = b & 7;
621 }
622 }
623
624#ifdef SUPPORT_TAGS
625 if (setup_use_tagged_queuing < 0)
626 setup_use_tagged_queuing = DEFAULT_USE_TAGGED_QUEUING;
627#endif
628#ifdef REAL_DMA
629 /* If running on a Falcon and if there's TT-Ram (i.e., more than one
630 * memory block, since there's always ST-Ram in a Falcon), then allocate a
631 * STRAM_BUFFER_SIZE byte dribble buffer for transfers from/to alternative
632 * Ram.
633 */
634 if (MACH_IS_ATARI && ATARIHW_PRESENT(ST_SCSI) &&
635 !ATARIHW_PRESENT(EXTD_DMA) && m68k_num_memory > 1) {
636 atari_dma_buffer = atari_stram_alloc(STRAM_BUFFER_SIZE, "SCSI");
637 if (!atari_dma_buffer) {
638 printk(KERN_ERR "atari_scsi_detect: can't allocate ST-RAM "
639 "double buffer\n");
640 return 0;
641 }
642 atari_dma_phys_buffer = virt_to_phys(atari_dma_buffer);
643 atari_dma_orig_addr = 0;
644 }
645#endif
646 instance = scsi_register(host, sizeof(struct NCR5380_hostdata));
647 if (instance == NULL) {
648 atari_stram_free(atari_dma_buffer);
649 atari_dma_buffer = 0;
650 return 0;
651 }
652 atari_scsi_host = instance;
653 /*
654 * Set irq to 0, to avoid that the mid-level code disables our interrupt
655 * during queue_command calls. This is completely unnecessary, and even
656 * worse causes bad problems on the Falcon, where the int is shared with
657 * IDE and floppy!
658 */
659 instance->irq = 0;
660
661#ifdef CONFIG_ATARI_SCSI_RESET_BOOT
662 atari_scsi_reset_boot();
663#endif
664 NCR5380_init(instance, 0);
665
666 if (IS_A_TT()) {
667
668 /* This int is actually "pseudo-slow", i.e. it acts like a slow
669 * interrupt after having cleared the pending flag for the DMA
670 * interrupt. */
671 if (request_irq(IRQ_TT_MFP_SCSI, scsi_tt_intr, IRQ_TYPE_SLOW,
672 "SCSI NCR5380", instance)) {
673 printk(KERN_ERR "atari_scsi_detect: cannot allocate irq %d, aborting",IRQ_TT_MFP_SCSI);
674 scsi_unregister(atari_scsi_host);
675 atari_stram_free(atari_dma_buffer);
676 atari_dma_buffer = 0;
677 return 0;
678 }
679 tt_mfp.active_edge |= 0x80; /* SCSI int on L->H */
680#ifdef REAL_DMA
681 tt_scsi_dma.dma_ctrl = 0;
682 atari_dma_residual = 0;
683
684 if (MACH_IS_MEDUSA) {
685 /* While the read overruns (described by Drew Eckhardt in
686 * NCR5380.c) never happened on TTs, they do in fact on the Medusa
687 * (This was the cause why SCSI didn't work right for so long
688 * there.) Since handling the overruns slows down a bit, I turned
689 * the #ifdef's into a runtime condition.
690 *
691 * In principle it should be sufficient to do max. 1 byte with
692 * PIO, but there is another problem on the Medusa with the DMA
693 * rest data register. So 'atari_read_overruns' is currently set
694 * to 4 to avoid having transfers that aren't a multiple of 4. If
695 * the rest data bug is fixed, this can be lowered to 1.
696 */
697 atari_read_overruns = 4;
698 }
699#endif /*REAL_DMA*/
700 } else { /* ! IS_A_TT */
701
702 /* Nothing to do for the interrupt: the ST-DMA is initialized
703 * already by atari_init_INTS()
704 */
705
706#ifdef REAL_DMA
707 atari_dma_residual = 0;
708 atari_dma_active = 0;
709 atari_dma_stram_mask = (ATARIHW_PRESENT(EXTD_DMA) ? 0x00000000
710 : 0xff000000);
711#endif
712 }
713
714 printk(KERN_INFO "scsi%d: options CAN_QUEUE=%d CMD_PER_LUN=%d SCAT-GAT=%d "
715#ifdef SUPPORT_TAGS
716 "TAGGED-QUEUING=%s "
717#endif
718 "HOSTID=%d",
719 instance->host_no, instance->hostt->can_queue,
720 instance->hostt->cmd_per_lun,
721 instance->hostt->sg_tablesize,
722#ifdef SUPPORT_TAGS
723 setup_use_tagged_queuing ? "yes" : "no",
724#endif
725 instance->hostt->this_id );
726 NCR5380_print_options(instance);
727 printk("\n");
728
729 called = 1;
730 return 1;
731}
732
733static int atari_scsi_release(struct Scsi_Host *sh)
734{
735 if (IS_A_TT())
736 free_irq(IRQ_TT_MFP_SCSI, sh);
737 if (atari_dma_buffer)
738 atari_stram_free(atari_dma_buffer);
739 NCR5380_exit(sh);
740 return 1;
741}
742
743#ifndef MODULE
744static int __init atari_scsi_setup(char *str)
745{
746 /* Format of atascsi parameter is:
747 * atascsi=<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
748 * Defaults depend on TT or Falcon, hostid determined at run time.
749 * Negative values mean don't change.
750 */
751 int ints[6];
752
753 get_options(str, ARRAY_SIZE(ints), ints);
754
755 if (ints[0] < 1) {
756 printk("atari_scsi_setup: no arguments!\n");
757 return 0;
758 }
759
760 if (ints[0] >= 1) {
761 if (ints[1] > 0)
762 /* no limits on this, just > 0 */
763 setup_can_queue = ints[1];
764 }
765 if (ints[0] >= 2) {
766 if (ints[2] > 0)
767 setup_cmd_per_lun = ints[2];
768 }
769 if (ints[0] >= 3) {
770 if (ints[3] >= 0) {
771 setup_sg_tablesize = ints[3];
772 /* Must be <= SG_ALL (255) */
773 if (setup_sg_tablesize > SG_ALL)
774 setup_sg_tablesize = SG_ALL;
775 }
776 }
777 if (ints[0] >= 4) {
778 /* Must be between 0 and 7 */
779 if (ints[4] >= 0 && ints[4] <= 7)
780 setup_hostid = ints[4];
781 else if (ints[4] > 7)
782 printk("atari_scsi_setup: invalid host ID %d !\n", ints[4]);
783 }
784#ifdef SUPPORT_TAGS
785 if (ints[0] >= 5) {
786 if (ints[5] >= 0)
787 setup_use_tagged_queuing = !!ints[5];
788 }
789#endif
790
791 return 1;
792}
793
794__setup("atascsi=", atari_scsi_setup);
795#endif /* !MODULE */
796
797static int atari_scsi_bus_reset(Scsi_Cmnd *cmd)
798{
799 int rv;
800 struct NCR5380_hostdata *hostdata =
801 (struct NCR5380_hostdata *)cmd->device->host->hostdata;
802
803 /* For doing the reset, SCSI interrupts must be disabled first,
804 * since the 5380 raises its IRQ line while _RST is active and we
805 * can't disable interrupts completely, since we need the timer.
806 */
807 /* And abort a maybe active DMA transfer */
808 if (IS_A_TT()) {
809 atari_turnoff_irq(IRQ_TT_MFP_SCSI);
810#ifdef REAL_DMA
811 tt_scsi_dma.dma_ctrl = 0;
812#endif /* REAL_DMA */
813 } else {
814 atari_turnoff_irq(IRQ_MFP_FSCSI);
815#ifdef REAL_DMA
816 st_dma.dma_mode_status = 0x90;
817 atari_dma_active = 0;
818 atari_dma_orig_addr = NULL;
819#endif /* REAL_DMA */
820 }
821
822 rv = NCR5380_bus_reset(cmd);
823
824 /* Re-enable ints */
825 if (IS_A_TT()) {
826 atari_turnon_irq(IRQ_TT_MFP_SCSI);
827 } else {
828 atari_turnon_irq(IRQ_MFP_FSCSI);
829 }
830 if ((rv & SCSI_RESET_ACTION) == SCSI_RESET_SUCCESS)
831 falcon_release_lock_if_possible(hostdata);
832
833 return rv;
834}
835
836
837#ifdef CONFIG_ATARI_SCSI_RESET_BOOT
838static void __init atari_scsi_reset_boot(void)
839{
840 unsigned long end;
841
842 /*
843 * Do a SCSI reset to clean up the bus during initialization. No messing
844 * with the queues, interrupts, or locks necessary here.
845 */
846
847 printk("Atari SCSI: resetting the SCSI bus...");
848
849 /* get in phase */
850 NCR5380_write(TARGET_COMMAND_REG,
851 PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG)));
852
853 /* assert RST */
854 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
855 /* The min. reset hold time is 25us, so 40us should be enough */
856 udelay(50);
857 /* reset RST and interrupt */
858 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
859 NCR5380_read(RESET_PARITY_INTERRUPT_REG);
860
861 end = jiffies + AFTER_RESET_DELAY;
862 while (time_before(jiffies, end))
863 barrier();
864
865 printk(" done\n");
866}
867#endif
868
869
870static const char *atari_scsi_info(struct Scsi_Host *host)
871{
872 /* atari_scsi_detect() is verbose enough... */
873 static const char string[] = "Atari native SCSI";
874 return string;
875}
876
877
878#if defined(REAL_DMA)
879
880static unsigned long atari_scsi_dma_setup(struct Scsi_Host *instance,
881 void *data, unsigned long count,
882 int dir)
883{
884 unsigned long addr = virt_to_phys(data);
885
886 DMA_PRINTK("scsi%d: setting up dma, data = %p, phys = %lx, count = %ld, "
887 "dir = %d\n", instance->host_no, data, addr, count, dir);
888
889 if (!IS_A_TT() && !STRAM_ADDR(addr)) {
890 /* If we have a non-DMAable address on a Falcon, use the dribble
891 * buffer; 'orig_addr' != 0 in the read case tells the interrupt
892 * handler to copy data from the dribble buffer to the originally
893 * wanted address.
894 */
895 if (dir)
896 memcpy(atari_dma_buffer, data, count);
897 else
898 atari_dma_orig_addr = data;
899 addr = atari_dma_phys_buffer;
900 }
901
902 atari_dma_startaddr = addr; /* Needed for calculating residual later. */
903
904 /* Cache cleanup stuff: On writes, push any dirty cache out before sending
905 * it to the peripheral. (Must be done before DMA setup, since at least
906 * the ST-DMA begins to fill internal buffers right after setup. For
907 * reads, invalidate any cache, may be altered after DMA without CPU
908 * knowledge.
909 *
910 * ++roman: For the Medusa, there's no need at all for that cache stuff,
911 * because the hardware does bus snooping (fine!).
912 */
913 dma_cache_maintenance(addr, count, dir);
914
915 if (count == 0)
916 printk(KERN_NOTICE "SCSI warning: DMA programmed for 0 bytes !\n");
917
918 if (IS_A_TT()) {
919 tt_scsi_dma.dma_ctrl = dir;
920 SCSI_DMA_WRITE_P(dma_addr, addr);
921 SCSI_DMA_WRITE_P(dma_cnt, count);
922 tt_scsi_dma.dma_ctrl = dir | 2;
923 } else { /* ! IS_A_TT */
924
925 /* set address */
926 SCSI_DMA_SETADR(addr);
927
928 /* toggle direction bit to clear FIFO and set DMA direction */
929 dir <<= 8;
930 st_dma.dma_mode_status = 0x90 | dir;
931 st_dma.dma_mode_status = 0x90 | (dir ^ 0x100);
932 st_dma.dma_mode_status = 0x90 | dir;
933 udelay(40);
934 /* On writes, round up the transfer length to the next multiple of 512
935 * (see also comment at atari_dma_xfer_len()). */
936 st_dma.fdc_acces_seccount = (count + (dir ? 511 : 0)) >> 9;
937 udelay(40);
938 st_dma.dma_mode_status = 0x10 | dir;
939 udelay(40);
940 /* need not restore value of dir, only boolean value is tested */
941 atari_dma_active = 1;
942 }
943
944 return count;
945}
946
947
948static long atari_scsi_dma_residual(struct Scsi_Host *instance)
949{
950 return atari_dma_residual;
951}
952
953
954#define CMD_SURELY_BLOCK_MODE 0
955#define CMD_SURELY_BYTE_MODE 1
956#define CMD_MODE_UNKNOWN 2
957
958static int falcon_classify_cmd(Scsi_Cmnd *cmd)
959{
960 unsigned char opcode = cmd->cmnd[0];
961
962 if (opcode == READ_DEFECT_DATA || opcode == READ_LONG ||
963 opcode == READ_BUFFER)
964 return CMD_SURELY_BYTE_MODE;
965 else if (opcode == READ_6 || opcode == READ_10 ||
966 opcode == 0xa8 /* READ_12 */ || opcode == READ_REVERSE ||
967 opcode == RECOVER_BUFFERED_DATA) {
968 /* In case of a sequential-access target (tape), special care is
969 * needed here: The transfer is block-mode only if the 'fixed' bit is
970 * set! */
971 if (cmd->device->type == TYPE_TAPE && !(cmd->cmnd[1] & 1))
972 return CMD_SURELY_BYTE_MODE;
973 else
974 return CMD_SURELY_BLOCK_MODE;
975 } else
976 return CMD_MODE_UNKNOWN;
977}
978
979
980/* This function calculates the number of bytes that can be transferred via
981 * DMA. On the TT, this is arbitrary, but on the Falcon we have to use the
982 * ST-DMA chip. There are only multiples of 512 bytes possible and max.
983 * 255*512 bytes :-( This means also, that defining READ_OVERRUNS is not
984 * possible on the Falcon, since that would require to program the DMA for
985 * n*512 - atari_read_overrun bytes. But it seems that the Falcon doesn't have
986 * the overrun problem, so this question is academic :-)
987 */
988
989static unsigned long atari_dma_xfer_len(unsigned long wanted_len,
990 Scsi_Cmnd *cmd, int write_flag)
991{
992 unsigned long possible_len, limit;
993
994 if (IS_A_TT())
995 /* TT SCSI DMA can transfer arbitrary #bytes */
996 return wanted_len;
997
998 /* ST DMA chip is stupid -- only multiples of 512 bytes! (and max.
999 * 255*512 bytes, but this should be enough)
1000 *
1001 * ++roman: Aaargl! Another Falcon-SCSI problem... There are some commands
1002 * that return a number of bytes which cannot be known beforehand. In this
1003 * case, the given transfer length is an "allocation length". Now it
1004 * can happen that this allocation length is a multiple of 512 bytes and
1005 * the DMA is used. But if not n*512 bytes really arrive, some input data
1006 * will be lost in the ST-DMA's FIFO :-( Thus, we have to distinguish
1007 * between commands that do block transfers and those that do byte
1008 * transfers. But this isn't easy... there are lots of vendor specific
1009 * commands, and the user can issue any command via the
1010 * SCSI_IOCTL_SEND_COMMAND.
1011 *
1012 * The solution: We classify SCSI commands in 1) surely block-mode cmd.s,
1013 * 2) surely byte-mode cmd.s and 3) cmd.s with unknown mode. In case 1)
1014 * and 3), the thing to do is obvious: allow any number of blocks via DMA
1015 * or none. In case 2), we apply some heuristic: Byte mode is assumed if
1016 * the transfer (allocation) length is < 1024, hoping that no cmd. not
1017 * explicitly known as byte mode have such big allocation lengths...
1018 * BTW, all the discussion above applies only to reads. DMA writes are
1019 * unproblematic anyways, since the targets aborts the transfer after
1020 * receiving a sufficient number of bytes.
1021 *
1022 * Another point: If the transfer is from/to an non-ST-RAM address, we
1023 * use the dribble buffer and thus can do only STRAM_BUFFER_SIZE bytes.
1024 */
1025
1026 if (write_flag) {
1027 /* Write operation can always use the DMA, but the transfer size must
1028 * be rounded up to the next multiple of 512 (atari_dma_setup() does
1029 * this).
1030 */
1031 possible_len = wanted_len;
1032 } else {
1033 /* Read operations: if the wanted transfer length is not a multiple of
1034 * 512, we cannot use DMA, since the ST-DMA cannot split transfers
1035 * (no interrupt on DMA finished!)
1036 */
1037 if (wanted_len & 0x1ff)
1038 possible_len = 0;
1039 else {
1040 /* Now classify the command (see above) and decide whether it is
1041 * allowed to do DMA at all */
1042 switch (falcon_classify_cmd(cmd)) {
1043 case CMD_SURELY_BLOCK_MODE:
1044 possible_len = wanted_len;
1045 break;
1046 case CMD_SURELY_BYTE_MODE:
1047 possible_len = 0; /* DMA prohibited */
1048 break;
1049 case CMD_MODE_UNKNOWN:
1050 default:
1051 /* For unknown commands assume block transfers if the transfer
1052 * size/allocation length is >= 1024 */
1053 possible_len = (wanted_len < 1024) ? 0 : wanted_len;
1054 break;
1055 }
1056 }
1057 }
1058
1059 /* Last step: apply the hard limit on DMA transfers */
1060 limit = (atari_dma_buffer && !STRAM_ADDR(virt_to_phys(cmd->SCp.ptr))) ?
1061 STRAM_BUFFER_SIZE : 255*512;
1062 if (possible_len > limit)
1063 possible_len = limit;
1064
1065 if (possible_len != wanted_len)
1066 DMA_PRINTK("Sorry, must cut DMA transfer size to %ld bytes "
1067 "instead of %ld\n", possible_len, wanted_len);
1068
1069 return possible_len;
1070}
1071
1072
1073#endif /* REAL_DMA */
1074
1075
1076/* NCR5380 register access functions
1077 *
1078 * There are separate functions for TT and Falcon, because the access
1079 * methods are quite different. The calling macros NCR5380_read and
1080 * NCR5380_write call these functions via function pointers.
1081 */
1082
1083static unsigned char atari_scsi_tt_reg_read(unsigned char reg)
1084{
1085 return tt_scsi_regp[reg * 2];
1086}
1087
1088static void atari_scsi_tt_reg_write(unsigned char reg, unsigned char value)
1089{
1090 tt_scsi_regp[reg * 2] = value;
1091}
1092
1093static unsigned char atari_scsi_falcon_reg_read(unsigned char reg)
1094{
1095 dma_wd.dma_mode_status= (u_short)(0x88 + reg);
1096 return (u_char)dma_wd.fdc_acces_seccount;
1097}
1098
1099static void atari_scsi_falcon_reg_write(unsigned char reg, unsigned char value)
1100{
1101 dma_wd.dma_mode_status = (u_short)(0x88 + reg);
1102 dma_wd.fdc_acces_seccount = (u_short)value;
1103}
1104
1105
1106#include "atari_NCR5380.c"
1107
1108static struct scsi_host_template driver_template = {
1109 .show_info = atari_scsi_show_info,
1110 .name = "Atari native SCSI",
1111 .detect = atari_scsi_detect,
1112 .release = atari_scsi_release,
1113 .info = atari_scsi_info,
1114 .queuecommand = atari_scsi_queue_command,
1115 .eh_abort_handler = atari_scsi_abort,
1116 .eh_bus_reset_handler = atari_scsi_bus_reset,
1117 .can_queue = 0, /* initialized at run-time */
1118 .this_id = 0, /* initialized at run-time */
1119 .sg_tablesize = 0, /* initialized at run-time */
1120 .cmd_per_lun = 0, /* initialized at run-time */
1121 .use_clustering = DISABLE_CLUSTERING
1122};
1123
1124
1125#include "scsi_module.c"
1126
1127MODULE_LICENSE("GPL");
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
133static 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
145static 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
157static 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
165static 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
189static int scsi_dma_is_ignored_buserr(unsigned char dma_stat);
190static void atari_scsi_fetch_restbytes(void);
191static long atari_scsi_dma_residual(struct Scsi_Host *instance);
192static int falcon_classify_cmd(Scsi_Cmnd *cmd);
193static unsigned long atari_dma_xfer_len(unsigned long wanted_len,
194 Scsi_Cmnd *cmd, int write_flag);
195#endif
196static irqreturn_t scsi_tt_intr(int irq, void *dummy);
197static irqreturn_t scsi_falcon_intr(int irq, void *dummy);
198static void falcon_release_lock_if_possible(struct NCR5380_hostdata *hostdata);
199static void falcon_get_lock(void);
200#ifdef CONFIG_ATARI_SCSI_RESET_BOOT
201static void atari_scsi_reset_boot(void);
202#endif
203static unsigned char atari_scsi_tt_reg_read(unsigned char reg);
204static void atari_scsi_tt_reg_write(unsigned char reg, unsigned char value);
205static unsigned char atari_scsi_falcon_reg_read(unsigned char reg);
206static void atari_scsi_falcon_reg_write(unsigned char reg, unsigned char value);
207
208/************************* End of Prototypes **************************/
209
210
211static struct Scsi_Host *atari_scsi_host;
212static unsigned char (*atari_scsi_reg_read)(unsigned char reg);
213static void (*atari_scsi_reg_write)(unsigned char reg, unsigned char value);
214
215#ifdef REAL_DMA
216static unsigned long atari_dma_residual, atari_dma_startaddr;
217static short atari_dma_active;
218/* pointer to the dribble buffer */
219static char *atari_dma_buffer;
220/* precalculated physical address of the dribble buffer */
221static unsigned long atari_dma_phys_buffer;
222/* != 0 tells the Falcon int handler to copy data from the dribble buffer */
223static 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 */
232static 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 */
235static int atari_read_overruns;
236#endif
237
238static int setup_can_queue = -1;
239module_param(setup_can_queue, int, 0);
240static int setup_cmd_per_lun = -1;
241module_param(setup_cmd_per_lun, int, 0);
242static int setup_sg_tablesize = -1;
243module_param(setup_sg_tablesize, int, 0);
244#ifdef SUPPORT_TAGS
245static int setup_use_tagged_queuing = -1;
246module_param(setup_use_tagged_queuing, int, 0);
247#endif
248static int setup_hostid = -1;
249module_param(setup_hostid, int, 0);
250
251
252#if defined(REAL_DMA)
253
254static 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 */
281static 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
309static 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
402static 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
463static 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
488static int falcon_got_lock = 0;
489static DECLARE_WAIT_QUEUE_HEAD(falcon_fairness_wait);
490static int falcon_trying_lock = 0;
491static DECLARE_WAIT_QUEUE_HEAD(falcon_try_wait);
492static 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
501static 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
543static 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
575int __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
727int 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
737void __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
782int 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
823static 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
855const 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
865unsigned 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
932static 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
942static 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
973static 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
1067static unsigned char atari_scsi_tt_reg_read(unsigned char reg)
1068{
1069 return tt_scsi_regp[reg * 2];
1070}
1071
1072static void atari_scsi_tt_reg_write(unsigned char reg, unsigned char value)
1073{
1074 tt_scsi_regp[reg * 2] = value;
1075}
1076
1077static 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
1083static 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
1092static 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
1111MODULE_LICENSE("GPL");