blob: f5732d8f67fec793badb30948d369710e9260a55 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
Linus Torvalds1da177e2005-04-16 15:20:36 -070068#include <linux/module.h>
69
70#define NDEBUG (0)
71
Roman Zippel3130d902007-05-01 22:32:37 +020072#define NDEBUG_ABORT 0x00100000
73#define NDEBUG_TAGS 0x00200000
74#define NDEBUG_MERGING 0x00400000
Linus Torvalds1da177e2005-04-16 15:20:36 -070075
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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070089#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
Roman Zippelc28bda22007-05-01 22:32:36 +0200189static 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);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195#endif
Roman Zippelc28bda22007-05-01 22:32:36 +0200196static 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);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200#ifdef CONFIG_ATARI_SCSI_RESET_BOOT
Roman Zippelc28bda22007-05-01 22:32:36 +0200201static void atari_scsi_reset_boot(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202#endif
Roman Zippelc28bda22007-05-01 22:32:36 +0200203static 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);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207
208/************************* End of Prototypes **************************/
209
210
Roman Zippelc28bda22007-05-01 22:32:36 +0200211static 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);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214
215#ifdef REAL_DMA
216static unsigned long atari_dma_residual, atari_dma_startaddr;
217static short atari_dma_active;
218/* pointer to the dribble buffer */
Roman Zippelc28bda22007-05-01 22:32:36 +0200219static char *atari_dma_buffer;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220/* 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 */
Roman Zippelc28bda22007-05-01 22:32:36 +0200235static int atari_read_overruns;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236#endif
237
238static int setup_can_queue = -1;
Rusty Russell8d3b33f2006-03-25 03:07:05 -0800239module_param(setup_can_queue, int, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240static int setup_cmd_per_lun = -1;
Rusty Russell8d3b33f2006-03-25 03:07:05 -0800241module_param(setup_cmd_per_lun, int, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242static int setup_sg_tablesize = -1;
Rusty Russell8d3b33f2006-03-25 03:07:05 -0800243module_param(setup_sg_tablesize, int, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244#ifdef SUPPORT_TAGS
245static int setup_use_tagged_queuing = -1;
Rusty Russell8d3b33f2006-03-25 03:07:05 -0800246module_param(setup_use_tagged_queuing, int, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247#endif
248static int setup_hostid = -1;
Rusty Russell8d3b33f2006-03-25 03:07:05 -0800249module_param(setup_hostid, int, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250
251
252#if defined(CONFIG_TT_DMA_EMUL)
253#include "atari_dma_emul.c"
254#endif
255
256#if defined(REAL_DMA)
257
Roman Zippelc28bda22007-05-01 22:32:36 +0200258static int scsi_dma_is_ignored_buserr(unsigned char dma_stat)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259{
260 int i;
Roman Zippelc28bda22007-05-01 22:32:36 +0200261 unsigned long addr = SCSI_DMA_READ_P(dma_addr), end_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262
263 if (dma_stat & 0x01) {
264
265 /* A bus error happens when DMA-ing from the last page of a
266 * physical memory chunk (DMA prefetch!), but that doesn't hurt.
267 * Check for this case:
268 */
Roman Zippelc28bda22007-05-01 22:32:36 +0200269
270 for (i = 0; i < m68k_num_memory; ++i) {
271 end_addr = m68k_memory[i].addr + m68k_memory[i].size;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272 if (end_addr <= addr && addr <= end_addr + 4)
Roman Zippelc28bda22007-05-01 22:32:36 +0200273 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274 }
275 }
Roman Zippelc28bda22007-05-01 22:32:36 +0200276 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277}
278
279
280#if 0
281/* Dead code... wasn't called anyway :-) and causes some trouble, because at
282 * end-of-DMA, both SCSI ints are triggered simultaneously, so the NCR int has
283 * to clear the DMA int pending bit before it allows other level 6 interrupts.
284 */
Roman Zippelc28bda22007-05-01 22:32:36 +0200285static void scsi_dma_buserr(int irq, void *dummy)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286{
Roman Zippelc28bda22007-05-01 22:32:36 +0200287 unsigned char dma_stat = tt_scsi_dma.dma_ctrl;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288
289 /* Don't do anything if a NCR interrupt is pending. Probably it's just
290 * masked... */
Roman Zippelc28bda22007-05-01 22:32:36 +0200291 if (atari_irq_pending(IRQ_TT_MFP_SCSI))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292 return;
Roman Zippelc28bda22007-05-01 22:32:36 +0200293
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294 printk("Bad SCSI DMA interrupt! dma_addr=0x%08lx dma_stat=%02x dma_cnt=%08lx\n",
295 SCSI_DMA_READ_P(dma_addr), dma_stat, SCSI_DMA_READ_P(dma_cnt));
296 if (dma_stat & 0x80) {
Roman Zippelc28bda22007-05-01 22:32:36 +0200297 if (!scsi_dma_is_ignored_buserr(dma_stat))
298 printk("SCSI DMA bus error -- bad DMA programming!\n");
299 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300 /* Under normal circumstances we never should get to this point,
301 * since both interrupts are triggered simultaneously and the 5380
302 * int has higher priority. When this irq is handled, that DMA
303 * interrupt is cleared. So a warning message is printed here.
304 */
Roman Zippelc28bda22007-05-01 22:32:36 +0200305 printk("SCSI DMA intr ?? -- this shouldn't happen!\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306 }
307}
308#endif
309
310#endif
311
312
Roman Zippelc28bda22007-05-01 22:32:36 +0200313static irqreturn_t scsi_tt_intr(int irq, void *dummy)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700314{
315#ifdef REAL_DMA
316 int dma_stat;
317
318 dma_stat = tt_scsi_dma.dma_ctrl;
319
320 INT_PRINTK("scsi%d: NCR5380 interrupt, DMA status = %02x\n",
321 atari_scsi_host->host_no, dma_stat & 0xff);
322
323 /* Look if it was the DMA that has interrupted: First possibility
324 * is that a bus error occurred...
325 */
326 if (dma_stat & 0x80) {
Roman Zippelc28bda22007-05-01 22:32:36 +0200327 if (!scsi_dma_is_ignored_buserr(dma_stat)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328 printk(KERN_ERR "SCSI DMA caused bus error near 0x%08lx\n",
329 SCSI_DMA_READ_P(dma_addr));
330 printk(KERN_CRIT "SCSI DMA bus error -- bad DMA programming!");
331 }
332 }
333
334 /* If the DMA is active but not finished, we have the case
335 * that some other 5380 interrupt occurred within the DMA transfer.
336 * This means we have residual bytes, if the desired end address
337 * is not yet reached. Maybe we have to fetch some bytes from the
338 * rest data register, too. The residual must be calculated from
339 * the address pointer, not the counter register, because only the
340 * addr reg counts bytes not yet written and pending in the rest
341 * data reg!
342 */
343 if ((dma_stat & 0x02) && !(dma_stat & 0x40)) {
Roman Zippelc28bda22007-05-01 22:32:36 +0200344 atari_dma_residual = HOSTDATA_DMALEN - (SCSI_DMA_READ_P(dma_addr) - atari_dma_startaddr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345
346 DMA_PRINTK("SCSI DMA: There are %ld residual bytes.\n",
347 atari_dma_residual);
348
349 if ((signed int)atari_dma_residual < 0)
350 atari_dma_residual = 0;
351 if ((dma_stat & 1) == 0) {
Roman Zippelc28bda22007-05-01 22:32:36 +0200352 /*
353 * After read operations, we maybe have to
354 * transport some rest bytes
355 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356 atari_scsi_fetch_restbytes();
Roman Zippelc28bda22007-05-01 22:32:36 +0200357 } else {
358 /*
359 * There seems to be a nasty bug in some SCSI-DMA/NCR
360 * combinations: If a target disconnects while a write
361 * operation is going on, the address register of the
362 * DMA may be a few bytes farer than it actually read.
363 * This is probably due to DMA prefetching and a delay
364 * between DMA and NCR. Experiments showed that the
365 * dma_addr is 9 bytes to high, but this could vary.
366 * The problem is, that the residual is thus calculated
367 * wrong and the next transfer will start behind where
368 * it should. So we round up the residual to the next
369 * multiple of a sector size, if it isn't already a
370 * multiple and the originally expected transfer size
371 * was. The latter condition is there to ensure that
372 * the correction is taken only for "real" data
373 * transfers and not for, e.g., the parameters of some
374 * other command. These shouldn't disconnect anyway.
375 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376 if (atari_dma_residual & 0x1ff) {
377 DMA_PRINTK("SCSI DMA: DMA bug corrected, "
378 "difference %ld bytes\n",
379 512 - (atari_dma_residual & 0x1ff));
380 atari_dma_residual = (atari_dma_residual + 511) & ~0x1ff;
381 }
382 }
383 tt_scsi_dma.dma_ctrl = 0;
384 }
385
386 /* If the DMA is finished, fetch the rest bytes and turn it off */
387 if (dma_stat & 0x40) {
388 atari_dma_residual = 0;
389 if ((dma_stat & 1) == 0)
390 atari_scsi_fetch_restbytes();
391 tt_scsi_dma.dma_ctrl = 0;
392 }
393
394#endif /* REAL_DMA */
Roman Zippelc28bda22007-05-01 22:32:36 +0200395
Jeff Garzik1e641662007-11-11 19:52:05 -0500396 NCR5380_intr(irq, dummy);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700397
398#if 0
399 /* To be sure the int is not masked */
Roman Zippelc28bda22007-05-01 22:32:36 +0200400 atari_enable_irq(IRQ_TT_MFP_SCSI);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700401#endif
402 return IRQ_HANDLED;
403}
404
405
Roman Zippelc28bda22007-05-01 22:32:36 +0200406static irqreturn_t scsi_falcon_intr(int irq, void *dummy)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407{
408#ifdef REAL_DMA
409 int dma_stat;
410
411 /* Turn off DMA and select sector counter register before
412 * accessing the status register (Atari recommendation!)
413 */
414 st_dma.dma_mode_status = 0x90;
415 dma_stat = st_dma.dma_mode_status;
416
417 /* Bit 0 indicates some error in the DMA process... don't know
418 * what happened exactly (no further docu).
419 */
420 if (!(dma_stat & 0x01)) {
421 /* DMA error */
422 printk(KERN_CRIT "SCSI DMA error near 0x%08lx!\n", SCSI_DMA_GETADR());
423 }
424
425 /* If the DMA was active, but now bit 1 is not clear, it is some
426 * other 5380 interrupt that finishes the DMA transfer. We have to
427 * calculate the number of residual bytes and give a warning if
428 * bytes are stuck in the ST-DMA fifo (there's no way to reach them!)
429 */
430 if (atari_dma_active && (dma_stat & 0x02)) {
Roman Zippelc28bda22007-05-01 22:32:36 +0200431 unsigned long transferred;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432
433 transferred = SCSI_DMA_GETADR() - atari_dma_startaddr;
434 /* The ST-DMA address is incremented in 2-byte steps, but the
435 * data are written only in 16-byte chunks. If the number of
436 * transferred bytes is not divisible by 16, the remainder is
437 * lost somewhere in outer space.
438 */
439 if (transferred & 15)
440 printk(KERN_ERR "SCSI DMA error: %ld bytes lost in "
441 "ST-DMA fifo\n", transferred & 15);
442
443 atari_dma_residual = HOSTDATA_DMALEN - transferred;
444 DMA_PRINTK("SCSI DMA: There are %ld residual bytes.\n",
445 atari_dma_residual);
Roman Zippelc28bda22007-05-01 22:32:36 +0200446 } else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447 atari_dma_residual = 0;
448 atari_dma_active = 0;
449
450 if (atari_dma_orig_addr) {
451 /* If the dribble buffer was used on a read operation, copy the DMA-ed
452 * data to the original destination address.
453 */
454 memcpy(atari_dma_orig_addr, phys_to_virt(atari_dma_startaddr),
455 HOSTDATA_DMALEN - atari_dma_residual);
456 atari_dma_orig_addr = NULL;
457 }
458
459#endif /* REAL_DMA */
460
Jeff Garzik1e641662007-11-11 19:52:05 -0500461 NCR5380_intr(irq, dummy);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462 return IRQ_HANDLED;
463}
464
465
466#ifdef REAL_DMA
Roman Zippelc28bda22007-05-01 22:32:36 +0200467static void atari_scsi_fetch_restbytes(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468{
469 int nr;
470 char *src, *dst;
471 unsigned long phys_dst;
472
473 /* fetch rest bytes in the DMA register */
474 phys_dst = SCSI_DMA_READ_P(dma_addr);
475 nr = phys_dst & 3;
476 if (nr) {
477 /* there are 'nr' bytes left for the last long address
478 before the DMA pointer */
479 phys_dst ^= nr;
480 DMA_PRINTK("SCSI DMA: there are %d rest bytes for phys addr 0x%08lx",
481 nr, phys_dst);
482 /* The content of the DMA pointer is a physical address! */
483 dst = phys_to_virt(phys_dst);
484 DMA_PRINTK(" = virt addr %p\n", dst);
485 for (src = (char *)&tt_scsi_dma.dma_restdata; nr != 0; --nr)
486 *dst++ = *src++;
487 }
488}
489#endif /* REAL_DMA */
490
491
492static int falcon_got_lock = 0;
493static DECLARE_WAIT_QUEUE_HEAD(falcon_fairness_wait);
494static int falcon_trying_lock = 0;
495static DECLARE_WAIT_QUEUE_HEAD(falcon_try_wait);
496static int falcon_dont_release = 0;
497
498/* This function releases the lock on the DMA chip if there is no
499 * connected command and the disconnected queue is empty. On
500 * releasing, instances of falcon_get_lock are awoken, that put
501 * themselves to sleep for fairness. They can now try to get the lock
502 * again (but others waiting longer more probably will win).
503 */
504
Roman Zippelc28bda22007-05-01 22:32:36 +0200505static void falcon_release_lock_if_possible(struct NCR5380_hostdata *hostdata)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506{
507 unsigned long flags;
Roman Zippelc28bda22007-05-01 22:32:36 +0200508
509 if (IS_A_TT())
510 return;
511
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512 local_irq_save(flags);
513
Roman Zippelc28bda22007-05-01 22:32:36 +0200514 if (falcon_got_lock && !hostdata->disconnected_queue &&
515 !hostdata->issue_queue && !hostdata->connected) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516
517 if (falcon_dont_release) {
518#if 0
519 printk("WARNING: Lock release not allowed. Ignored\n");
520#endif
521 local_irq_restore(flags);
522 return;
523 }
524 falcon_got_lock = 0;
525 stdma_release();
Roman Zippelc28bda22007-05-01 22:32:36 +0200526 wake_up(&falcon_fairness_wait);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700527 }
528
529 local_irq_restore(flags);
530}
531
532/* This function manages the locking of the ST-DMA.
533 * If the DMA isn't locked already for SCSI, it tries to lock it by
534 * calling stdma_lock(). But if the DMA is locked by the SCSI code and
535 * there are other drivers waiting for the chip, we do not issue the
536 * command immediately but wait on 'falcon_fairness_queue'. We will be
537 * waked up when the DMA is unlocked by some SCSI interrupt. After that
538 * we try to get the lock again.
539 * But we must be prepared that more than one instance of
540 * falcon_get_lock() is waiting on the fairness queue. They should not
541 * try all at once to call stdma_lock(), one is enough! For that, the
542 * first one sets 'falcon_trying_lock', others that see that variable
543 * set wait on the queue 'falcon_try_wait'.
544 * Complicated, complicated.... Sigh...
545 */
546
Roman Zippelc28bda22007-05-01 22:32:36 +0200547static void falcon_get_lock(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548{
549 unsigned long flags;
550
Roman Zippelc28bda22007-05-01 22:32:36 +0200551 if (IS_A_TT())
552 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553
554 local_irq_save(flags);
555
Michael Schmitzfb810d12007-05-01 22:32:35 +0200556 while (!in_irq() && falcon_got_lock && stdma_others_waiting())
Roman Zippelc28bda22007-05-01 22:32:36 +0200557 sleep_on(&falcon_fairness_wait);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558
559 while (!falcon_got_lock) {
Michael Schmitzfb810d12007-05-01 22:32:35 +0200560 if (in_irq())
Roman Zippelc28bda22007-05-01 22:32:36 +0200561 panic("Falcon SCSI hasn't ST-DMA lock in interrupt");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700562 if (!falcon_trying_lock) {
563 falcon_trying_lock = 1;
564 stdma_lock(scsi_falcon_intr, NULL);
565 falcon_got_lock = 1;
566 falcon_trying_lock = 0;
Roman Zippelc28bda22007-05-01 22:32:36 +0200567 wake_up(&falcon_try_wait);
568 } else {
569 sleep_on(&falcon_try_wait);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700570 }
Roman Zippelc28bda22007-05-01 22:32:36 +0200571 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700572
573 local_irq_restore(flags);
574 if (!falcon_got_lock)
575 panic("Falcon SCSI: someone stole the lock :-(\n");
576}
577
578
579/* This is the wrapper function for NCR5380_queue_command(). It just
580 * tries to get the lock on the ST-DMA (see above) and then calls the
581 * original function.
582 */
583
584#if 0
Roman Zippelc28bda22007-05-01 22:32:36 +0200585int atari_queue_command(Scsi_Cmnd *cmd, void (*done)(Scsi_Cmnd *))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586{
587 /* falcon_get_lock();
588 * ++guenther: moved to NCR5380_queue_command() to prevent
589 * race condition, see there for an explanation.
590 */
Roman Zippelc28bda22007-05-01 22:32:36 +0200591 return NCR5380_queue_command(cmd, done);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700592}
593#endif
594
595
Roman Zippelc28bda22007-05-01 22:32:36 +0200596int atari_scsi_detect(struct scsi_host_template *host)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700597{
598 static int called = 0;
599 struct Scsi_Host *instance;
600
601 if (!MACH_IS_ATARI ||
602 (!ATARIHW_PRESENT(ST_SCSI) && !ATARIHW_PRESENT(TT_SCSI)) ||
603 called)
Roman Zippelc28bda22007-05-01 22:32:36 +0200604 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700605
606 host->proc_name = "Atari";
607
608 atari_scsi_reg_read = IS_A_TT() ? atari_scsi_tt_reg_read :
609 atari_scsi_falcon_reg_read;
610 atari_scsi_reg_write = IS_A_TT() ? atari_scsi_tt_reg_write :
611 atari_scsi_falcon_reg_write;
612
613 /* setup variables */
614 host->can_queue =
615 (setup_can_queue > 0) ? setup_can_queue :
616 IS_A_TT() ? ATARI_TT_CAN_QUEUE : ATARI_FALCON_CAN_QUEUE;
617 host->cmd_per_lun =
618 (setup_cmd_per_lun > 0) ? setup_cmd_per_lun :
619 IS_A_TT() ? ATARI_TT_CMD_PER_LUN : ATARI_FALCON_CMD_PER_LUN;
620 /* Force sg_tablesize to 0 on a Falcon! */
621 host->sg_tablesize =
622 !IS_A_TT() ? ATARI_FALCON_SG_TABLESIZE :
623 (setup_sg_tablesize >= 0) ? setup_sg_tablesize : ATARI_TT_SG_TABLESIZE;
624
625 if (setup_hostid >= 0)
626 host->this_id = setup_hostid;
627 else {
628 /* use 7 as default */
629 host->this_id = 7;
630 /* Test if a host id is set in the NVRam */
631 if (ATARIHW_PRESENT(TT_CLK) && nvram_check_checksum()) {
632 unsigned char b = nvram_read_byte( 14 );
633 /* Arbitration enabled? (for TOS) If yes, use configured host ID */
634 if (b & 0x80)
635 host->this_id = b & 7;
636 }
637 }
638
639#ifdef SUPPORT_TAGS
640 if (setup_use_tagged_queuing < 0)
641 setup_use_tagged_queuing = DEFAULT_USE_TAGGED_QUEUING;
642#endif
643#ifdef REAL_DMA
644 /* If running on a Falcon and if there's TT-Ram (i.e., more than one
645 * memory block, since there's always ST-Ram in a Falcon), then allocate a
646 * STRAM_BUFFER_SIZE byte dribble buffer for transfers from/to alternative
647 * Ram.
648 */
649 if (MACH_IS_ATARI && ATARIHW_PRESENT(ST_SCSI) &&
650 !ATARIHW_PRESENT(EXTD_DMA) && m68k_num_memory > 1) {
651 atari_dma_buffer = atari_stram_alloc(STRAM_BUFFER_SIZE, "SCSI");
652 if (!atari_dma_buffer) {
Roman Zippelc28bda22007-05-01 22:32:36 +0200653 printk(KERN_ERR "atari_scsi_detect: can't allocate ST-RAM "
654 "double buffer\n");
655 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700656 }
Roman Zippelc28bda22007-05-01 22:32:36 +0200657 atari_dma_phys_buffer = virt_to_phys(atari_dma_buffer);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700658 atari_dma_orig_addr = 0;
659 }
660#endif
Roman Zippelc28bda22007-05-01 22:32:36 +0200661 instance = scsi_register(host, sizeof(struct NCR5380_hostdata));
662 if (instance == NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663 atari_stram_free(atari_dma_buffer);
664 atari_dma_buffer = 0;
665 return 0;
666 }
667 atari_scsi_host = instance;
Roman Zippelc28bda22007-05-01 22:32:36 +0200668 /*
669 * Set irq to 0, to avoid that the mid-level code disables our interrupt
670 * during queue_command calls. This is completely unnecessary, and even
671 * worse causes bad problems on the Falcon, where the int is shared with
672 * IDE and floppy!
673 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700674 instance->irq = 0;
675
676#ifdef CONFIG_ATARI_SCSI_RESET_BOOT
677 atari_scsi_reset_boot();
678#endif
Roman Zippelc28bda22007-05-01 22:32:36 +0200679 NCR5380_init(instance, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680
681 if (IS_A_TT()) {
682
683 /* This int is actually "pseudo-slow", i.e. it acts like a slow
684 * interrupt after having cleared the pending flag for the DMA
685 * interrupt. */
686 if (request_irq(IRQ_TT_MFP_SCSI, scsi_tt_intr, IRQ_TYPE_SLOW,
Jeff Garzik1e641662007-11-11 19:52:05 -0500687 "SCSI NCR5380", instance)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700688 printk(KERN_ERR "atari_scsi_detect: cannot allocate irq %d, aborting",IRQ_TT_MFP_SCSI);
689 scsi_unregister(atari_scsi_host);
690 atari_stram_free(atari_dma_buffer);
691 atari_dma_buffer = 0;
692 return 0;
693 }
694 tt_mfp.active_edge |= 0x80; /* SCSI int on L->H */
695#ifdef REAL_DMA
696 tt_scsi_dma.dma_ctrl = 0;
697 atari_dma_residual = 0;
698#ifdef CONFIG_TT_DMA_EMUL
699 if (MACH_IS_HADES) {
700 if (request_irq(IRQ_AUTO_2, hades_dma_emulator,
701 IRQ_TYPE_PRIO, "Hades DMA emulator",
702 hades_dma_emulator)) {
703 printk(KERN_ERR "atari_scsi_detect: cannot allocate irq %d, aborting (MACH_IS_HADES)",IRQ_AUTO_2);
Jeff Garzik1e641662007-11-11 19:52:05 -0500704 free_irq(IRQ_TT_MFP_SCSI, instance);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700705 scsi_unregister(atari_scsi_host);
706 atari_stram_free(atari_dma_buffer);
707 atari_dma_buffer = 0;
708 return 0;
709 }
710 }
711#endif
712 if (MACH_IS_MEDUSA || MACH_IS_HADES) {
713 /* While the read overruns (described by Drew Eckhardt in
714 * NCR5380.c) never happened on TTs, they do in fact on the Medusa
715 * (This was the cause why SCSI didn't work right for so long
716 * there.) Since handling the overruns slows down a bit, I turned
717 * the #ifdef's into a runtime condition.
718 *
719 * In principle it should be sufficient to do max. 1 byte with
720 * PIO, but there is another problem on the Medusa with the DMA
721 * rest data register. So 'atari_read_overruns' is currently set
722 * to 4 to avoid having transfers that aren't a multiple of 4. If
723 * the rest data bug is fixed, this can be lowered to 1.
724 */
725 atari_read_overruns = 4;
Roman Zippelc28bda22007-05-01 22:32:36 +0200726 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700727#endif /*REAL_DMA*/
Roman Zippelc28bda22007-05-01 22:32:36 +0200728 } else { /* ! IS_A_TT */
729
Linus Torvalds1da177e2005-04-16 15:20:36 -0700730 /* Nothing to do for the interrupt: the ST-DMA is initialized
731 * already by atari_init_INTS()
732 */
733
734#ifdef REAL_DMA
735 atari_dma_residual = 0;
736 atari_dma_active = 0;
737 atari_dma_stram_mask = (ATARIHW_PRESENT(EXTD_DMA) ? 0x00000000
738 : 0xff000000);
739#endif
740 }
741
742 printk(KERN_INFO "scsi%d: options CAN_QUEUE=%d CMD_PER_LUN=%d SCAT-GAT=%d "
743#ifdef SUPPORT_TAGS
744 "TAGGED-QUEUING=%s "
745#endif
746 "HOSTID=%d",
747 instance->host_no, instance->hostt->can_queue,
748 instance->hostt->cmd_per_lun,
749 instance->hostt->sg_tablesize,
750#ifdef SUPPORT_TAGS
751 setup_use_tagged_queuing ? "yes" : "no",
752#endif
753 instance->hostt->this_id );
Roman Zippelc28bda22007-05-01 22:32:36 +0200754 NCR5380_print_options(instance);
755 printk("\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700756
757 called = 1;
Roman Zippelc28bda22007-05-01 22:32:36 +0200758 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700759}
760
Roman Zippelc28bda22007-05-01 22:32:36 +0200761int atari_scsi_release(struct Scsi_Host *sh)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700762{
763 if (IS_A_TT())
Jeff Garzik1e641662007-11-11 19:52:05 -0500764 free_irq(IRQ_TT_MFP_SCSI, sh);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765 if (atari_dma_buffer)
Roman Zippelc28bda22007-05-01 22:32:36 +0200766 atari_stram_free(atari_dma_buffer);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700767 return 1;
768}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700769
770void __init atari_scsi_setup(char *str, int *ints)
771{
772 /* Format of atascsi parameter is:
773 * atascsi=<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
774 * Defaults depend on TT or Falcon, hostid determined at run time.
775 * Negative values mean don't change.
776 */
Roman Zippelc28bda22007-05-01 22:32:36 +0200777
Linus Torvalds1da177e2005-04-16 15:20:36 -0700778 if (ints[0] < 1) {
Roman Zippelc28bda22007-05-01 22:32:36 +0200779 printk("atari_scsi_setup: no arguments!\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700780 return;
781 }
782
783 if (ints[0] >= 1) {
784 if (ints[1] > 0)
785 /* no limits on this, just > 0 */
786 setup_can_queue = ints[1];
787 }
788 if (ints[0] >= 2) {
789 if (ints[2] > 0)
790 setup_cmd_per_lun = ints[2];
791 }
792 if (ints[0] >= 3) {
793 if (ints[3] >= 0) {
794 setup_sg_tablesize = ints[3];
795 /* Must be <= SG_ALL (255) */
796 if (setup_sg_tablesize > SG_ALL)
797 setup_sg_tablesize = SG_ALL;
798 }
799 }
800 if (ints[0] >= 4) {
801 /* Must be between 0 and 7 */
802 if (ints[4] >= 0 && ints[4] <= 7)
803 setup_hostid = ints[4];
804 else if (ints[4] > 7)
Roman Zippelc28bda22007-05-01 22:32:36 +0200805 printk("atari_scsi_setup: invalid host ID %d !\n", ints[4]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700806 }
807#ifdef SUPPORT_TAGS
808 if (ints[0] >= 5) {
809 if (ints[5] >= 0)
810 setup_use_tagged_queuing = !!ints[5];
811 }
812#endif
813}
814
815int atari_scsi_bus_reset(Scsi_Cmnd *cmd)
816{
Roman Zippelc28bda22007-05-01 22:32:36 +0200817 int rv;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700818 struct NCR5380_hostdata *hostdata =
819 (struct NCR5380_hostdata *)cmd->device->host->hostdata;
820
821 /* For doing the reset, SCSI interrupts must be disabled first,
822 * since the 5380 raises its IRQ line while _RST is active and we
823 * can't disable interrupts completely, since we need the timer.
824 */
825 /* And abort a maybe active DMA transfer */
826 if (IS_A_TT()) {
Roman Zippelc28bda22007-05-01 22:32:36 +0200827 atari_turnoff_irq(IRQ_TT_MFP_SCSI);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700828#ifdef REAL_DMA
829 tt_scsi_dma.dma_ctrl = 0;
830#endif /* REAL_DMA */
Roman Zippelc28bda22007-05-01 22:32:36 +0200831 } else {
832 atari_turnoff_irq(IRQ_MFP_FSCSI);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700833#ifdef REAL_DMA
834 st_dma.dma_mode_status = 0x90;
835 atari_dma_active = 0;
836 atari_dma_orig_addr = NULL;
837#endif /* REAL_DMA */
838 }
839
840 rv = NCR5380_bus_reset(cmd);
841
842 /* Re-enable ints */
843 if (IS_A_TT()) {
Roman Zippelc28bda22007-05-01 22:32:36 +0200844 atari_turnon_irq(IRQ_TT_MFP_SCSI);
845 } else {
846 atari_turnon_irq(IRQ_MFP_FSCSI);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700847 }
848 if ((rv & SCSI_RESET_ACTION) == SCSI_RESET_SUCCESS)
849 falcon_release_lock_if_possible(hostdata);
850
Roman Zippelc28bda22007-05-01 22:32:36 +0200851 return rv;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700852}
853
Roman Zippelc28bda22007-05-01 22:32:36 +0200854
Linus Torvalds1da177e2005-04-16 15:20:36 -0700855#ifdef CONFIG_ATARI_SCSI_RESET_BOOT
856static void __init atari_scsi_reset_boot(void)
857{
858 unsigned long end;
Roman Zippelc28bda22007-05-01 22:32:36 +0200859
Linus Torvalds1da177e2005-04-16 15:20:36 -0700860 /*
861 * Do a SCSI reset to clean up the bus during initialization. No messing
862 * with the queues, interrupts, or locks necessary here.
863 */
864
Roman Zippelc28bda22007-05-01 22:32:36 +0200865 printk("Atari SCSI: resetting the SCSI bus...");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700866
867 /* get in phase */
Roman Zippelc28bda22007-05-01 22:32:36 +0200868 NCR5380_write(TARGET_COMMAND_REG,
869 PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG)));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700870
871 /* assert RST */
Roman Zippelc28bda22007-05-01 22:32:36 +0200872 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700873 /* The min. reset hold time is 25us, so 40us should be enough */
Roman Zippelc28bda22007-05-01 22:32:36 +0200874 udelay(50);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700875 /* reset RST and interrupt */
Roman Zippelc28bda22007-05-01 22:32:36 +0200876 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
877 NCR5380_read(RESET_PARITY_INTERRUPT_REG);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700878
879 end = jiffies + AFTER_RESET_DELAY;
880 while (time_before(jiffies, end))
881 barrier();
882
Roman Zippelc28bda22007-05-01 22:32:36 +0200883 printk(" done\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700884}
885#endif
886
887
Roman Zippelc28bda22007-05-01 22:32:36 +0200888const char *atari_scsi_info(struct Scsi_Host *host)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700889{
890 /* atari_scsi_detect() is verbose enough... */
891 static const char string[] = "Atari native SCSI";
892 return string;
893}
894
895
896#if defined(REAL_DMA)
897
Roman Zippelc28bda22007-05-01 22:32:36 +0200898unsigned long atari_scsi_dma_setup(struct Scsi_Host *instance, void *data,
899 unsigned long count, int dir)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700900{
Roman Zippelc28bda22007-05-01 22:32:36 +0200901 unsigned long addr = virt_to_phys(data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700902
903 DMA_PRINTK("scsi%d: setting up dma, data = %p, phys = %lx, count = %ld, "
904 "dir = %d\n", instance->host_no, data, addr, count, dir);
905
906 if (!IS_A_TT() && !STRAM_ADDR(addr)) {
907 /* If we have a non-DMAable address on a Falcon, use the dribble
908 * buffer; 'orig_addr' != 0 in the read case tells the interrupt
909 * handler to copy data from the dribble buffer to the originally
910 * wanted address.
911 */
912 if (dir)
Roman Zippelc28bda22007-05-01 22:32:36 +0200913 memcpy(atari_dma_buffer, data, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700914 else
915 atari_dma_orig_addr = data;
916 addr = atari_dma_phys_buffer;
917 }
Roman Zippelc28bda22007-05-01 22:32:36 +0200918
Linus Torvalds1da177e2005-04-16 15:20:36 -0700919 atari_dma_startaddr = addr; /* Needed for calculating residual later. */
Roman Zippelc28bda22007-05-01 22:32:36 +0200920
Linus Torvalds1da177e2005-04-16 15:20:36 -0700921 /* Cache cleanup stuff: On writes, push any dirty cache out before sending
922 * it to the peripheral. (Must be done before DMA setup, since at least
923 * the ST-DMA begins to fill internal buffers right after setup. For
924 * reads, invalidate any cache, may be altered after DMA without CPU
925 * knowledge.
Roman Zippelc28bda22007-05-01 22:32:36 +0200926 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700927 * ++roman: For the Medusa, there's no need at all for that cache stuff,
928 * because the hardware does bus snooping (fine!).
929 */
Roman Zippelc28bda22007-05-01 22:32:36 +0200930 dma_cache_maintenance(addr, count, dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700931
932 if (count == 0)
933 printk(KERN_NOTICE "SCSI warning: DMA programmed for 0 bytes !\n");
934
935 if (IS_A_TT()) {
936 tt_scsi_dma.dma_ctrl = dir;
Roman Zippelc28bda22007-05-01 22:32:36 +0200937 SCSI_DMA_WRITE_P(dma_addr, addr);
938 SCSI_DMA_WRITE_P(dma_cnt, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700939 tt_scsi_dma.dma_ctrl = dir | 2;
Roman Zippelc28bda22007-05-01 22:32:36 +0200940 } else { /* ! IS_A_TT */
941
Linus Torvalds1da177e2005-04-16 15:20:36 -0700942 /* set address */
Roman Zippelc28bda22007-05-01 22:32:36 +0200943 SCSI_DMA_SETADR(addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700944
945 /* toggle direction bit to clear FIFO and set DMA direction */
946 dir <<= 8;
947 st_dma.dma_mode_status = 0x90 | dir;
948 st_dma.dma_mode_status = 0x90 | (dir ^ 0x100);
949 st_dma.dma_mode_status = 0x90 | dir;
950 udelay(40);
951 /* On writes, round up the transfer length to the next multiple of 512
952 * (see also comment at atari_dma_xfer_len()). */
953 st_dma.fdc_acces_seccount = (count + (dir ? 511 : 0)) >> 9;
954 udelay(40);
955 st_dma.dma_mode_status = 0x10 | dir;
956 udelay(40);
957 /* need not restore value of dir, only boolean value is tested */
958 atari_dma_active = 1;
959 }
960
Roman Zippelc28bda22007-05-01 22:32:36 +0200961 return count;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700962}
963
964
Roman Zippelc28bda22007-05-01 22:32:36 +0200965static long atari_scsi_dma_residual(struct Scsi_Host *instance)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700966{
Roman Zippelc28bda22007-05-01 22:32:36 +0200967 return atari_dma_residual;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700968}
969
970
971#define CMD_SURELY_BLOCK_MODE 0
972#define CMD_SURELY_BYTE_MODE 1
973#define CMD_MODE_UNKNOWN 2
974
Roman Zippelc28bda22007-05-01 22:32:36 +0200975static int falcon_classify_cmd(Scsi_Cmnd *cmd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700976{
977 unsigned char opcode = cmd->cmnd[0];
Roman Zippelc28bda22007-05-01 22:32:36 +0200978
Linus Torvalds1da177e2005-04-16 15:20:36 -0700979 if (opcode == READ_DEFECT_DATA || opcode == READ_LONG ||
Roman Zippelc28bda22007-05-01 22:32:36 +0200980 opcode == READ_BUFFER)
981 return CMD_SURELY_BYTE_MODE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700982 else if (opcode == READ_6 || opcode == READ_10 ||
983 opcode == 0xa8 /* READ_12 */ || opcode == READ_REVERSE ||
984 opcode == RECOVER_BUFFERED_DATA) {
985 /* In case of a sequential-access target (tape), special care is
986 * needed here: The transfer is block-mode only if the 'fixed' bit is
987 * set! */
988 if (cmd->device->type == TYPE_TAPE && !(cmd->cmnd[1] & 1))
Roman Zippelc28bda22007-05-01 22:32:36 +0200989 return CMD_SURELY_BYTE_MODE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700990 else
Roman Zippelc28bda22007-05-01 22:32:36 +0200991 return CMD_SURELY_BLOCK_MODE;
992 } else
993 return CMD_MODE_UNKNOWN;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700994}
995
996
997/* This function calculates the number of bytes that can be transferred via
998 * DMA. On the TT, this is arbitrary, but on the Falcon we have to use the
999 * ST-DMA chip. There are only multiples of 512 bytes possible and max.
1000 * 255*512 bytes :-( This means also, that defining READ_OVERRUNS is not
1001 * possible on the Falcon, since that would require to program the DMA for
1002 * n*512 - atari_read_overrun bytes. But it seems that the Falcon doesn't have
1003 * the overrun problem, so this question is academic :-)
1004 */
1005
Roman Zippelc28bda22007-05-01 22:32:36 +02001006static unsigned long atari_dma_xfer_len(unsigned long wanted_len,
1007 Scsi_Cmnd *cmd, int write_flag)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001008{
1009 unsigned long possible_len, limit;
1010#ifndef CONFIG_TT_DMA_EMUL
1011 if (MACH_IS_HADES)
1012 /* Hades has no SCSI DMA at all :-( Always force use of PIO */
Roman Zippelc28bda22007-05-01 22:32:36 +02001013 return 0;
1014#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001015 if (IS_A_TT())
1016 /* TT SCSI DMA can transfer arbitrary #bytes */
Roman Zippelc28bda22007-05-01 22:32:36 +02001017 return wanted_len;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001018
1019 /* ST DMA chip is stupid -- only multiples of 512 bytes! (and max.
1020 * 255*512 bytes, but this should be enough)
1021 *
1022 * ++roman: Aaargl! Another Falcon-SCSI problem... There are some commands
1023 * that return a number of bytes which cannot be known beforehand. In this
1024 * case, the given transfer length is an "allocation length". Now it
1025 * can happen that this allocation length is a multiple of 512 bytes and
1026 * the DMA is used. But if not n*512 bytes really arrive, some input data
1027 * will be lost in the ST-DMA's FIFO :-( Thus, we have to distinguish
1028 * between commands that do block transfers and those that do byte
1029 * transfers. But this isn't easy... there are lots of vendor specific
1030 * commands, and the user can issue any command via the
1031 * SCSI_IOCTL_SEND_COMMAND.
1032 *
1033 * The solution: We classify SCSI commands in 1) surely block-mode cmd.s,
1034 * 2) surely byte-mode cmd.s and 3) cmd.s with unknown mode. In case 1)
1035 * and 3), the thing to do is obvious: allow any number of blocks via DMA
1036 * or none. In case 2), we apply some heuristic: Byte mode is assumed if
1037 * the transfer (allocation) length is < 1024, hoping that no cmd. not
1038 * explicitly known as byte mode have such big allocation lengths...
1039 * BTW, all the discussion above applies only to reads. DMA writes are
1040 * unproblematic anyways, since the targets aborts the transfer after
1041 * receiving a sufficient number of bytes.
1042 *
1043 * Another point: If the transfer is from/to an non-ST-RAM address, we
1044 * use the dribble buffer and thus can do only STRAM_BUFFER_SIZE bytes.
1045 */
1046
1047 if (write_flag) {
1048 /* Write operation can always use the DMA, but the transfer size must
1049 * be rounded up to the next multiple of 512 (atari_dma_setup() does
1050 * this).
1051 */
1052 possible_len = wanted_len;
Roman Zippelc28bda22007-05-01 22:32:36 +02001053 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001054 /* Read operations: if the wanted transfer length is not a multiple of
1055 * 512, we cannot use DMA, since the ST-DMA cannot split transfers
1056 * (no interrupt on DMA finished!)
1057 */
1058 if (wanted_len & 0x1ff)
1059 possible_len = 0;
1060 else {
1061 /* Now classify the command (see above) and decide whether it is
1062 * allowed to do DMA at all */
Roman Zippelc28bda22007-05-01 22:32:36 +02001063 switch (falcon_classify_cmd(cmd)) {
1064 case CMD_SURELY_BLOCK_MODE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001065 possible_len = wanted_len;
1066 break;
Roman Zippelc28bda22007-05-01 22:32:36 +02001067 case CMD_SURELY_BYTE_MODE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001068 possible_len = 0; /* DMA prohibited */
1069 break;
Roman Zippelc28bda22007-05-01 22:32:36 +02001070 case CMD_MODE_UNKNOWN:
1071 default:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001072 /* For unknown commands assume block transfers if the transfer
1073 * size/allocation length is >= 1024 */
1074 possible_len = (wanted_len < 1024) ? 0 : wanted_len;
1075 break;
1076 }
1077 }
1078 }
Roman Zippelc28bda22007-05-01 22:32:36 +02001079
Linus Torvalds1da177e2005-04-16 15:20:36 -07001080 /* Last step: apply the hard limit on DMA transfers */
Roman Zippelc28bda22007-05-01 22:32:36 +02001081 limit = (atari_dma_buffer && !STRAM_ADDR(virt_to_phys(cmd->SCp.ptr))) ?
Linus Torvalds1da177e2005-04-16 15:20:36 -07001082 STRAM_BUFFER_SIZE : 255*512;
1083 if (possible_len > limit)
1084 possible_len = limit;
1085
1086 if (possible_len != wanted_len)
1087 DMA_PRINTK("Sorry, must cut DMA transfer size to %ld bytes "
1088 "instead of %ld\n", possible_len, wanted_len);
1089
Roman Zippelc28bda22007-05-01 22:32:36 +02001090 return possible_len;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001091}
1092
1093
1094#endif /* REAL_DMA */
1095
1096
1097/* NCR5380 register access functions
1098 *
1099 * There are separate functions for TT and Falcon, because the access
1100 * methods are quite different. The calling macros NCR5380_read and
1101 * NCR5380_write call these functions via function pointers.
1102 */
1103
Roman Zippelc28bda22007-05-01 22:32:36 +02001104static unsigned char atari_scsi_tt_reg_read(unsigned char reg)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001105{
Roman Zippelc28bda22007-05-01 22:32:36 +02001106 return tt_scsi_regp[reg * 2];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001107}
1108
Roman Zippelc28bda22007-05-01 22:32:36 +02001109static void atari_scsi_tt_reg_write(unsigned char reg, unsigned char value)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001110{
1111 tt_scsi_regp[reg * 2] = value;
1112}
1113
Roman Zippelc28bda22007-05-01 22:32:36 +02001114static unsigned char atari_scsi_falcon_reg_read(unsigned char reg)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001115{
1116 dma_wd.dma_mode_status= (u_short)(0x88 + reg);
Roman Zippelc28bda22007-05-01 22:32:36 +02001117 return (u_char)dma_wd.fdc_acces_seccount;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001118}
1119
Roman Zippelc28bda22007-05-01 22:32:36 +02001120static void atari_scsi_falcon_reg_write(unsigned char reg, unsigned char value)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001121{
1122 dma_wd.dma_mode_status = (u_short)(0x88 + reg);
1123 dma_wd.fdc_acces_seccount = (u_short)value;
1124}
1125
1126
1127#include "atari_NCR5380.c"
1128
Christoph Hellwigd0be4a7d2005-10-31 18:31:40 +01001129static struct scsi_host_template driver_template = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001130 .proc_info = atari_scsi_proc_info,
1131 .name = "Atari native SCSI",
1132 .detect = atari_scsi_detect,
1133 .release = atari_scsi_release,
1134 .info = atari_scsi_info,
1135 .queuecommand = atari_scsi_queue_command,
1136 .eh_abort_handler = atari_scsi_abort,
1137 .eh_bus_reset_handler = atari_scsi_bus_reset,
1138 .can_queue = 0, /* initialized at run-time */
1139 .this_id = 0, /* initialized at run-time */
1140 .sg_tablesize = 0, /* initialized at run-time */
1141 .cmd_per_lun = 0, /* initialized at run-time */
1142 .use_clustering = DISABLE_CLUSTERING
1143};
1144
1145
1146#include "scsi_module.c"
1147
1148MODULE_LICENSE("GPL");