blob: 21fe07f9df87be3ebd5222d8ce15eaea2e04d5d4 [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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252#if defined(REAL_DMA)
253
Roman Zippelc28bda22007-05-01 22:32:36 +0200254static int scsi_dma_is_ignored_buserr(unsigned char dma_stat)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255{
256 int i;
Roman Zippelc28bda22007-05-01 22:32:36 +0200257 unsigned long addr = SCSI_DMA_READ_P(dma_addr), end_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258
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 */
Roman Zippelc28bda22007-05-01 22:32:36 +0200265
266 for (i = 0; i < m68k_num_memory; ++i) {
267 end_addr = m68k_memory[i].addr + m68k_memory[i].size;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268 if (end_addr <= addr && addr <= end_addr + 4)
Roman Zippelc28bda22007-05-01 22:32:36 +0200269 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270 }
271 }
Roman Zippelc28bda22007-05-01 22:32:36 +0200272 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273}
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 */
Roman Zippelc28bda22007-05-01 22:32:36 +0200281static void scsi_dma_buserr(int irq, void *dummy)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282{
Roman Zippelc28bda22007-05-01 22:32:36 +0200283 unsigned char dma_stat = tt_scsi_dma.dma_ctrl;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284
285 /* Don't do anything if a NCR interrupt is pending. Probably it's just
286 * masked... */
Roman Zippelc28bda22007-05-01 22:32:36 +0200287 if (atari_irq_pending(IRQ_TT_MFP_SCSI))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288 return;
Roman Zippelc28bda22007-05-01 22:32:36 +0200289
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290 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) {
Roman Zippelc28bda22007-05-01 22:32:36 +0200293 if (!scsi_dma_is_ignored_buserr(dma_stat))
294 printk("SCSI DMA bus error -- bad DMA programming!\n");
295 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296 /* 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 */
Roman Zippelc28bda22007-05-01 22:32:36 +0200301 printk("SCSI DMA intr ?? -- this shouldn't happen!\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302 }
303}
304#endif
305
306#endif
307
308
Roman Zippelc28bda22007-05-01 22:32:36 +0200309static irqreturn_t scsi_tt_intr(int irq, void *dummy)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310{
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) {
Roman Zippelc28bda22007-05-01 22:32:36 +0200323 if (!scsi_dma_is_ignored_buserr(dma_stat)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324 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)) {
Roman Zippelc28bda22007-05-01 22:32:36 +0200340 atari_dma_residual = HOSTDATA_DMALEN - (SCSI_DMA_READ_P(dma_addr) - atari_dma_startaddr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341
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) {
Roman Zippelc28bda22007-05-01 22:32:36 +0200348 /*
349 * After read operations, we maybe have to
350 * transport some rest bytes
351 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352 atari_scsi_fetch_restbytes();
Roman Zippelc28bda22007-05-01 22:32:36 +0200353 } 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 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372 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 */
Roman Zippelc28bda22007-05-01 22:32:36 +0200391
Jeff Garzik1e641662007-11-11 19:52:05 -0500392 NCR5380_intr(irq, dummy);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393
394#if 0
395 /* To be sure the int is not masked */
Roman Zippelc28bda22007-05-01 22:32:36 +0200396 atari_enable_irq(IRQ_TT_MFP_SCSI);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700397#endif
398 return IRQ_HANDLED;
399}
400
401
Roman Zippelc28bda22007-05-01 22:32:36 +0200402static irqreturn_t scsi_falcon_intr(int irq, void *dummy)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403{
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)) {
Roman Zippelc28bda22007-05-01 22:32:36 +0200427 unsigned long transferred;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428
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);
Roman Zippelc28bda22007-05-01 22:32:36 +0200442 } else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443 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
Jeff Garzik1e641662007-11-11 19:52:05 -0500457 NCR5380_intr(irq, dummy);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700458 return IRQ_HANDLED;
459}
460
461
462#ifdef REAL_DMA
Roman Zippelc28bda22007-05-01 22:32:36 +0200463static void atari_scsi_fetch_restbytes(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464{
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
Roman Zippelc28bda22007-05-01 22:32:36 +0200501static void falcon_release_lock_if_possible(struct NCR5380_hostdata *hostdata)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700502{
503 unsigned long flags;
Roman Zippelc28bda22007-05-01 22:32:36 +0200504
505 if (IS_A_TT())
506 return;
507
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508 local_irq_save(flags);
509
Roman Zippelc28bda22007-05-01 22:32:36 +0200510 if (falcon_got_lock && !hostdata->disconnected_queue &&
511 !hostdata->issue_queue && !hostdata->connected) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512
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();
Roman Zippelc28bda22007-05-01 22:32:36 +0200522 wake_up(&falcon_fairness_wait);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523 }
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
Roman Zippelc28bda22007-05-01 22:32:36 +0200543static void falcon_get_lock(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544{
545 unsigned long flags;
546
Roman Zippelc28bda22007-05-01 22:32:36 +0200547 if (IS_A_TT())
548 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549
550 local_irq_save(flags);
551
Michael Schmitzfb810d12007-05-01 22:32:35 +0200552 while (!in_irq() && falcon_got_lock && stdma_others_waiting())
Roman Zippelc28bda22007-05-01 22:32:36 +0200553 sleep_on(&falcon_fairness_wait);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554
555 while (!falcon_got_lock) {
Michael Schmitzfb810d12007-05-01 22:32:35 +0200556 if (in_irq())
Roman Zippelc28bda22007-05-01 22:32:36 +0200557 panic("Falcon SCSI hasn't ST-DMA lock in interrupt");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558 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;
Roman Zippelc28bda22007-05-01 22:32:36 +0200563 wake_up(&falcon_try_wait);
564 } else {
565 sleep_on(&falcon_try_wait);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700566 }
Roman Zippelc28bda22007-05-01 22:32:36 +0200567 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568
569 local_irq_restore(flags);
570 if (!falcon_got_lock)
571 panic("Falcon SCSI: someone stole the lock :-(\n");
572}
573
574
575/* This is the wrapper function for NCR5380_queue_command(). It just
576 * tries to get the lock on the ST-DMA (see above) and then calls the
577 * original function.
578 */
579
580#if 0
Roman Zippelc28bda22007-05-01 22:32:36 +0200581int atari_queue_command(Scsi_Cmnd *cmd, void (*done)(Scsi_Cmnd *))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582{
583 /* falcon_get_lock();
584 * ++guenther: moved to NCR5380_queue_command() to prevent
585 * race condition, see there for an explanation.
586 */
Roman Zippelc28bda22007-05-01 22:32:36 +0200587 return NCR5380_queue_command(cmd, done);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588}
589#endif
590
591
Roman Zippelc28bda22007-05-01 22:32:36 +0200592int atari_scsi_detect(struct scsi_host_template *host)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700593{
594 static int called = 0;
595 struct Scsi_Host *instance;
596
597 if (!MACH_IS_ATARI ||
598 (!ATARIHW_PRESENT(ST_SCSI) && !ATARIHW_PRESENT(TT_SCSI)) ||
599 called)
Roman Zippelc28bda22007-05-01 22:32:36 +0200600 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700601
602 host->proc_name = "Atari";
603
604 atari_scsi_reg_read = IS_A_TT() ? atari_scsi_tt_reg_read :
605 atari_scsi_falcon_reg_read;
606 atari_scsi_reg_write = IS_A_TT() ? atari_scsi_tt_reg_write :
607 atari_scsi_falcon_reg_write;
608
609 /* setup variables */
610 host->can_queue =
611 (setup_can_queue > 0) ? setup_can_queue :
612 IS_A_TT() ? ATARI_TT_CAN_QUEUE : ATARI_FALCON_CAN_QUEUE;
613 host->cmd_per_lun =
614 (setup_cmd_per_lun > 0) ? setup_cmd_per_lun :
615 IS_A_TT() ? ATARI_TT_CMD_PER_LUN : ATARI_FALCON_CMD_PER_LUN;
616 /* Force sg_tablesize to 0 on a Falcon! */
617 host->sg_tablesize =
618 !IS_A_TT() ? ATARI_FALCON_SG_TABLESIZE :
619 (setup_sg_tablesize >= 0) ? setup_sg_tablesize : ATARI_TT_SG_TABLESIZE;
620
621 if (setup_hostid >= 0)
622 host->this_id = setup_hostid;
623 else {
624 /* use 7 as default */
625 host->this_id = 7;
626 /* Test if a host id is set in the NVRam */
627 if (ATARIHW_PRESENT(TT_CLK) && nvram_check_checksum()) {
628 unsigned char b = nvram_read_byte( 14 );
629 /* Arbitration enabled? (for TOS) If yes, use configured host ID */
630 if (b & 0x80)
631 host->this_id = b & 7;
632 }
633 }
634
635#ifdef SUPPORT_TAGS
636 if (setup_use_tagged_queuing < 0)
637 setup_use_tagged_queuing = DEFAULT_USE_TAGGED_QUEUING;
638#endif
639#ifdef REAL_DMA
640 /* If running on a Falcon and if there's TT-Ram (i.e., more than one
641 * memory block, since there's always ST-Ram in a Falcon), then allocate a
642 * STRAM_BUFFER_SIZE byte dribble buffer for transfers from/to alternative
643 * Ram.
644 */
645 if (MACH_IS_ATARI && ATARIHW_PRESENT(ST_SCSI) &&
646 !ATARIHW_PRESENT(EXTD_DMA) && m68k_num_memory > 1) {
647 atari_dma_buffer = atari_stram_alloc(STRAM_BUFFER_SIZE, "SCSI");
648 if (!atari_dma_buffer) {
Roman Zippelc28bda22007-05-01 22:32:36 +0200649 printk(KERN_ERR "atari_scsi_detect: can't allocate ST-RAM "
650 "double buffer\n");
651 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700652 }
Roman Zippelc28bda22007-05-01 22:32:36 +0200653 atari_dma_phys_buffer = virt_to_phys(atari_dma_buffer);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654 atari_dma_orig_addr = 0;
655 }
656#endif
Roman Zippelc28bda22007-05-01 22:32:36 +0200657 instance = scsi_register(host, sizeof(struct NCR5380_hostdata));
658 if (instance == NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659 atari_stram_free(atari_dma_buffer);
660 atari_dma_buffer = 0;
661 return 0;
662 }
663 atari_scsi_host = instance;
Roman Zippelc28bda22007-05-01 22:32:36 +0200664 /*
665 * Set irq to 0, to avoid that the mid-level code disables our interrupt
666 * during queue_command calls. This is completely unnecessary, and even
667 * worse causes bad problems on the Falcon, where the int is shared with
668 * IDE and floppy!
669 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670 instance->irq = 0;
671
672#ifdef CONFIG_ATARI_SCSI_RESET_BOOT
673 atari_scsi_reset_boot();
674#endif
Roman Zippelc28bda22007-05-01 22:32:36 +0200675 NCR5380_init(instance, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676
677 if (IS_A_TT()) {
678
679 /* This int is actually "pseudo-slow", i.e. it acts like a slow
680 * interrupt after having cleared the pending flag for the DMA
681 * interrupt. */
682 if (request_irq(IRQ_TT_MFP_SCSI, scsi_tt_intr, IRQ_TYPE_SLOW,
Jeff Garzik1e641662007-11-11 19:52:05 -0500683 "SCSI NCR5380", instance)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684 printk(KERN_ERR "atari_scsi_detect: cannot allocate irq %d, aborting",IRQ_TT_MFP_SCSI);
685 scsi_unregister(atari_scsi_host);
686 atari_stram_free(atari_dma_buffer);
687 atari_dma_buffer = 0;
688 return 0;
689 }
690 tt_mfp.active_edge |= 0x80; /* SCSI int on L->H */
691#ifdef REAL_DMA
692 tt_scsi_dma.dma_ctrl = 0;
693 atari_dma_residual = 0;
Adrian Bunk29c8a242008-10-13 21:58:59 +0200694
695 if (MACH_IS_MEDUSA) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700696 /* While the read overruns (described by Drew Eckhardt in
697 * NCR5380.c) never happened on TTs, they do in fact on the Medusa
698 * (This was the cause why SCSI didn't work right for so long
699 * there.) Since handling the overruns slows down a bit, I turned
700 * the #ifdef's into a runtime condition.
701 *
702 * In principle it should be sufficient to do max. 1 byte with
703 * PIO, but there is another problem on the Medusa with the DMA
704 * rest data register. So 'atari_read_overruns' is currently set
705 * to 4 to avoid having transfers that aren't a multiple of 4. If
706 * the rest data bug is fixed, this can be lowered to 1.
707 */
708 atari_read_overruns = 4;
Roman Zippelc28bda22007-05-01 22:32:36 +0200709 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700710#endif /*REAL_DMA*/
Roman Zippelc28bda22007-05-01 22:32:36 +0200711 } else { /* ! IS_A_TT */
712
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713 /* Nothing to do for the interrupt: the ST-DMA is initialized
714 * already by atari_init_INTS()
715 */
716
717#ifdef REAL_DMA
718 atari_dma_residual = 0;
719 atari_dma_active = 0;
720 atari_dma_stram_mask = (ATARIHW_PRESENT(EXTD_DMA) ? 0x00000000
721 : 0xff000000);
722#endif
723 }
724
725 printk(KERN_INFO "scsi%d: options CAN_QUEUE=%d CMD_PER_LUN=%d SCAT-GAT=%d "
726#ifdef SUPPORT_TAGS
727 "TAGGED-QUEUING=%s "
728#endif
729 "HOSTID=%d",
730 instance->host_no, instance->hostt->can_queue,
731 instance->hostt->cmd_per_lun,
732 instance->hostt->sg_tablesize,
733#ifdef SUPPORT_TAGS
734 setup_use_tagged_queuing ? "yes" : "no",
735#endif
736 instance->hostt->this_id );
Roman Zippelc28bda22007-05-01 22:32:36 +0200737 NCR5380_print_options(instance);
738 printk("\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700739
740 called = 1;
Roman Zippelc28bda22007-05-01 22:32:36 +0200741 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700742}
743
Roman Zippelc28bda22007-05-01 22:32:36 +0200744int atari_scsi_release(struct Scsi_Host *sh)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700745{
746 if (IS_A_TT())
Jeff Garzik1e641662007-11-11 19:52:05 -0500747 free_irq(IRQ_TT_MFP_SCSI, sh);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700748 if (atari_dma_buffer)
Roman Zippelc28bda22007-05-01 22:32:36 +0200749 atari_stram_free(atari_dma_buffer);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700750 return 1;
751}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700752
753void __init atari_scsi_setup(char *str, int *ints)
754{
755 /* Format of atascsi parameter is:
756 * atascsi=<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
757 * Defaults depend on TT or Falcon, hostid determined at run time.
758 * Negative values mean don't change.
759 */
Roman Zippelc28bda22007-05-01 22:32:36 +0200760
Linus Torvalds1da177e2005-04-16 15:20:36 -0700761 if (ints[0] < 1) {
Roman Zippelc28bda22007-05-01 22:32:36 +0200762 printk("atari_scsi_setup: no arguments!\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763 return;
764 }
765
766 if (ints[0] >= 1) {
767 if (ints[1] > 0)
768 /* no limits on this, just > 0 */
769 setup_can_queue = ints[1];
770 }
771 if (ints[0] >= 2) {
772 if (ints[2] > 0)
773 setup_cmd_per_lun = ints[2];
774 }
775 if (ints[0] >= 3) {
776 if (ints[3] >= 0) {
777 setup_sg_tablesize = ints[3];
778 /* Must be <= SG_ALL (255) */
779 if (setup_sg_tablesize > SG_ALL)
780 setup_sg_tablesize = SG_ALL;
781 }
782 }
783 if (ints[0] >= 4) {
784 /* Must be between 0 and 7 */
785 if (ints[4] >= 0 && ints[4] <= 7)
786 setup_hostid = ints[4];
787 else if (ints[4] > 7)
Roman Zippelc28bda22007-05-01 22:32:36 +0200788 printk("atari_scsi_setup: invalid host ID %d !\n", ints[4]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700789 }
790#ifdef SUPPORT_TAGS
791 if (ints[0] >= 5) {
792 if (ints[5] >= 0)
793 setup_use_tagged_queuing = !!ints[5];
794 }
795#endif
796}
797
798int atari_scsi_bus_reset(Scsi_Cmnd *cmd)
799{
Roman Zippelc28bda22007-05-01 22:32:36 +0200800 int rv;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700801 struct NCR5380_hostdata *hostdata =
802 (struct NCR5380_hostdata *)cmd->device->host->hostdata;
803
804 /* For doing the reset, SCSI interrupts must be disabled first,
805 * since the 5380 raises its IRQ line while _RST is active and we
806 * can't disable interrupts completely, since we need the timer.
807 */
808 /* And abort a maybe active DMA transfer */
809 if (IS_A_TT()) {
Roman Zippelc28bda22007-05-01 22:32:36 +0200810 atari_turnoff_irq(IRQ_TT_MFP_SCSI);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700811#ifdef REAL_DMA
812 tt_scsi_dma.dma_ctrl = 0;
813#endif /* REAL_DMA */
Roman Zippelc28bda22007-05-01 22:32:36 +0200814 } else {
815 atari_turnoff_irq(IRQ_MFP_FSCSI);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700816#ifdef REAL_DMA
817 st_dma.dma_mode_status = 0x90;
818 atari_dma_active = 0;
819 atari_dma_orig_addr = NULL;
820#endif /* REAL_DMA */
821 }
822
823 rv = NCR5380_bus_reset(cmd);
824
825 /* Re-enable ints */
826 if (IS_A_TT()) {
Roman Zippelc28bda22007-05-01 22:32:36 +0200827 atari_turnon_irq(IRQ_TT_MFP_SCSI);
828 } else {
829 atari_turnon_irq(IRQ_MFP_FSCSI);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700830 }
831 if ((rv & SCSI_RESET_ACTION) == SCSI_RESET_SUCCESS)
832 falcon_release_lock_if_possible(hostdata);
833
Roman Zippelc28bda22007-05-01 22:32:36 +0200834 return rv;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700835}
836
Roman Zippelc28bda22007-05-01 22:32:36 +0200837
Linus Torvalds1da177e2005-04-16 15:20:36 -0700838#ifdef CONFIG_ATARI_SCSI_RESET_BOOT
839static void __init atari_scsi_reset_boot(void)
840{
841 unsigned long end;
Roman Zippelc28bda22007-05-01 22:32:36 +0200842
Linus Torvalds1da177e2005-04-16 15:20:36 -0700843 /*
844 * Do a SCSI reset to clean up the bus during initialization. No messing
845 * with the queues, interrupts, or locks necessary here.
846 */
847
Roman Zippelc28bda22007-05-01 22:32:36 +0200848 printk("Atari SCSI: resetting the SCSI bus...");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700849
850 /* get in phase */
Roman Zippelc28bda22007-05-01 22:32:36 +0200851 NCR5380_write(TARGET_COMMAND_REG,
852 PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG)));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700853
854 /* assert RST */
Roman Zippelc28bda22007-05-01 22:32:36 +0200855 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700856 /* The min. reset hold time is 25us, so 40us should be enough */
Roman Zippelc28bda22007-05-01 22:32:36 +0200857 udelay(50);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700858 /* reset RST and interrupt */
Roman Zippelc28bda22007-05-01 22:32:36 +0200859 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
860 NCR5380_read(RESET_PARITY_INTERRUPT_REG);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700861
862 end = jiffies + AFTER_RESET_DELAY;
863 while (time_before(jiffies, end))
864 barrier();
865
Roman Zippelc28bda22007-05-01 22:32:36 +0200866 printk(" done\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700867}
868#endif
869
870
Roman Zippelc28bda22007-05-01 22:32:36 +0200871const char *atari_scsi_info(struct Scsi_Host *host)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700872{
873 /* atari_scsi_detect() is verbose enough... */
874 static const char string[] = "Atari native SCSI";
875 return string;
876}
877
878
879#if defined(REAL_DMA)
880
Roman Zippelc28bda22007-05-01 22:32:36 +0200881unsigned long atari_scsi_dma_setup(struct Scsi_Host *instance, void *data,
882 unsigned long count, int dir)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883{
Roman Zippelc28bda22007-05-01 22:32:36 +0200884 unsigned long addr = virt_to_phys(data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700885
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)
Roman Zippelc28bda22007-05-01 22:32:36 +0200896 memcpy(atari_dma_buffer, data, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700897 else
898 atari_dma_orig_addr = data;
899 addr = atari_dma_phys_buffer;
900 }
Roman Zippelc28bda22007-05-01 22:32:36 +0200901
Linus Torvalds1da177e2005-04-16 15:20:36 -0700902 atari_dma_startaddr = addr; /* Needed for calculating residual later. */
Roman Zippelc28bda22007-05-01 22:32:36 +0200903
Linus Torvalds1da177e2005-04-16 15:20:36 -0700904 /* 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.
Roman Zippelc28bda22007-05-01 22:32:36 +0200909 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700910 * ++roman: For the Medusa, there's no need at all for that cache stuff,
911 * because the hardware does bus snooping (fine!).
912 */
Roman Zippelc28bda22007-05-01 22:32:36 +0200913 dma_cache_maintenance(addr, count, dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700914
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;
Roman Zippelc28bda22007-05-01 22:32:36 +0200920 SCSI_DMA_WRITE_P(dma_addr, addr);
921 SCSI_DMA_WRITE_P(dma_cnt, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700922 tt_scsi_dma.dma_ctrl = dir | 2;
Roman Zippelc28bda22007-05-01 22:32:36 +0200923 } else { /* ! IS_A_TT */
924
Linus Torvalds1da177e2005-04-16 15:20:36 -0700925 /* set address */
Roman Zippelc28bda22007-05-01 22:32:36 +0200926 SCSI_DMA_SETADR(addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700927
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
Roman Zippelc28bda22007-05-01 22:32:36 +0200944 return count;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700945}
946
947
Roman Zippelc28bda22007-05-01 22:32:36 +0200948static long atari_scsi_dma_residual(struct Scsi_Host *instance)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700949{
Roman Zippelc28bda22007-05-01 22:32:36 +0200950 return atari_dma_residual;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700951}
952
953
954#define CMD_SURELY_BLOCK_MODE 0
955#define CMD_SURELY_BYTE_MODE 1
956#define CMD_MODE_UNKNOWN 2
957
Roman Zippelc28bda22007-05-01 22:32:36 +0200958static int falcon_classify_cmd(Scsi_Cmnd *cmd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700959{
960 unsigned char opcode = cmd->cmnd[0];
Roman Zippelc28bda22007-05-01 22:32:36 +0200961
Linus Torvalds1da177e2005-04-16 15:20:36 -0700962 if (opcode == READ_DEFECT_DATA || opcode == READ_LONG ||
Roman Zippelc28bda22007-05-01 22:32:36 +0200963 opcode == READ_BUFFER)
964 return CMD_SURELY_BYTE_MODE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700965 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))
Roman Zippelc28bda22007-05-01 22:32:36 +0200972 return CMD_SURELY_BYTE_MODE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700973 else
Roman Zippelc28bda22007-05-01 22:32:36 +0200974 return CMD_SURELY_BLOCK_MODE;
975 } else
976 return CMD_MODE_UNKNOWN;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700977}
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
Roman Zippelc28bda22007-05-01 22:32:36 +0200989static unsigned long atari_dma_xfer_len(unsigned long wanted_len,
990 Scsi_Cmnd *cmd, int write_flag)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700991{
992 unsigned long possible_len, limit;
Adrian Bunk29c8a242008-10-13 21:58:59 +0200993
Linus Torvalds1da177e2005-04-16 15:20:36 -0700994 if (IS_A_TT())
995 /* TT SCSI DMA can transfer arbitrary #bytes */
Roman Zippelc28bda22007-05-01 22:32:36 +0200996 return wanted_len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700997
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;
Roman Zippelc28bda22007-05-01 22:32:36 +02001032 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001033 /* 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 */
Roman Zippelc28bda22007-05-01 22:32:36 +02001042 switch (falcon_classify_cmd(cmd)) {
1043 case CMD_SURELY_BLOCK_MODE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001044 possible_len = wanted_len;
1045 break;
Roman Zippelc28bda22007-05-01 22:32:36 +02001046 case CMD_SURELY_BYTE_MODE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001047 possible_len = 0; /* DMA prohibited */
1048 break;
Roman Zippelc28bda22007-05-01 22:32:36 +02001049 case CMD_MODE_UNKNOWN:
1050 default:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001051 /* 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 }
Roman Zippelc28bda22007-05-01 22:32:36 +02001058
Linus Torvalds1da177e2005-04-16 15:20:36 -07001059 /* Last step: apply the hard limit on DMA transfers */
Roman Zippelc28bda22007-05-01 22:32:36 +02001060 limit = (atari_dma_buffer && !STRAM_ADDR(virt_to_phys(cmd->SCp.ptr))) ?
Linus Torvalds1da177e2005-04-16 15:20:36 -07001061 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
Roman Zippelc28bda22007-05-01 22:32:36 +02001069 return possible_len;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001070}
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
Roman Zippelc28bda22007-05-01 22:32:36 +02001083static unsigned char atari_scsi_tt_reg_read(unsigned char reg)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001084{
Roman Zippelc28bda22007-05-01 22:32:36 +02001085 return tt_scsi_regp[reg * 2];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001086}
1087
Roman Zippelc28bda22007-05-01 22:32:36 +02001088static void atari_scsi_tt_reg_write(unsigned char reg, unsigned char value)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001089{
1090 tt_scsi_regp[reg * 2] = value;
1091}
1092
Roman Zippelc28bda22007-05-01 22:32:36 +02001093static unsigned char atari_scsi_falcon_reg_read(unsigned char reg)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001094{
1095 dma_wd.dma_mode_status= (u_short)(0x88 + reg);
Roman Zippelc28bda22007-05-01 22:32:36 +02001096 return (u_char)dma_wd.fdc_acces_seccount;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001097}
1098
Roman Zippelc28bda22007-05-01 22:32:36 +02001099static void atari_scsi_falcon_reg_write(unsigned char reg, unsigned char value)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001100{
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
Christoph Hellwigd0be4a7d2005-10-31 18:31:40 +01001108static struct scsi_host_template driver_template = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001109 .proc_info = atari_scsi_proc_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");