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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
Geert Uytterhoeven107b5d52011-06-12 20:48:33 +0200575static int __init atari_scsi_detect(struct scsi_host_template *host)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576{
577 static int called = 0;
578 struct Scsi_Host *instance;
579
580 if (!MACH_IS_ATARI ||
581 (!ATARIHW_PRESENT(ST_SCSI) && !ATARIHW_PRESENT(TT_SCSI)) ||
582 called)
Roman Zippelc28bda22007-05-01 22:32:36 +0200583 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584
585 host->proc_name = "Atari";
586
587 atari_scsi_reg_read = IS_A_TT() ? atari_scsi_tt_reg_read :
588 atari_scsi_falcon_reg_read;
589 atari_scsi_reg_write = IS_A_TT() ? atari_scsi_tt_reg_write :
590 atari_scsi_falcon_reg_write;
591
592 /* setup variables */
593 host->can_queue =
594 (setup_can_queue > 0) ? setup_can_queue :
595 IS_A_TT() ? ATARI_TT_CAN_QUEUE : ATARI_FALCON_CAN_QUEUE;
596 host->cmd_per_lun =
597 (setup_cmd_per_lun > 0) ? setup_cmd_per_lun :
598 IS_A_TT() ? ATARI_TT_CMD_PER_LUN : ATARI_FALCON_CMD_PER_LUN;
599 /* Force sg_tablesize to 0 on a Falcon! */
600 host->sg_tablesize =
601 !IS_A_TT() ? ATARI_FALCON_SG_TABLESIZE :
602 (setup_sg_tablesize >= 0) ? setup_sg_tablesize : ATARI_TT_SG_TABLESIZE;
603
604 if (setup_hostid >= 0)
605 host->this_id = setup_hostid;
606 else {
607 /* use 7 as default */
608 host->this_id = 7;
609 /* Test if a host id is set in the NVRam */
610 if (ATARIHW_PRESENT(TT_CLK) && nvram_check_checksum()) {
611 unsigned char b = nvram_read_byte( 14 );
612 /* Arbitration enabled? (for TOS) If yes, use configured host ID */
613 if (b & 0x80)
614 host->this_id = b & 7;
615 }
616 }
617
618#ifdef SUPPORT_TAGS
619 if (setup_use_tagged_queuing < 0)
620 setup_use_tagged_queuing = DEFAULT_USE_TAGGED_QUEUING;
621#endif
622#ifdef REAL_DMA
623 /* If running on a Falcon and if there's TT-Ram (i.e., more than one
624 * memory block, since there's always ST-Ram in a Falcon), then allocate a
625 * STRAM_BUFFER_SIZE byte dribble buffer for transfers from/to alternative
626 * Ram.
627 */
628 if (MACH_IS_ATARI && ATARIHW_PRESENT(ST_SCSI) &&
629 !ATARIHW_PRESENT(EXTD_DMA) && m68k_num_memory > 1) {
630 atari_dma_buffer = atari_stram_alloc(STRAM_BUFFER_SIZE, "SCSI");
631 if (!atari_dma_buffer) {
Roman Zippelc28bda22007-05-01 22:32:36 +0200632 printk(KERN_ERR "atari_scsi_detect: can't allocate ST-RAM "
633 "double buffer\n");
634 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700635 }
Roman Zippelc28bda22007-05-01 22:32:36 +0200636 atari_dma_phys_buffer = virt_to_phys(atari_dma_buffer);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637 atari_dma_orig_addr = 0;
638 }
639#endif
Roman Zippelc28bda22007-05-01 22:32:36 +0200640 instance = scsi_register(host, sizeof(struct NCR5380_hostdata));
641 if (instance == NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700642 atari_stram_free(atari_dma_buffer);
643 atari_dma_buffer = 0;
644 return 0;
645 }
646 atari_scsi_host = instance;
Roman Zippelc28bda22007-05-01 22:32:36 +0200647 /*
648 * Set irq to 0, to avoid that the mid-level code disables our interrupt
649 * during queue_command calls. This is completely unnecessary, and even
650 * worse causes bad problems on the Falcon, where the int is shared with
651 * IDE and floppy!
652 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700653 instance->irq = 0;
654
655#ifdef CONFIG_ATARI_SCSI_RESET_BOOT
656 atari_scsi_reset_boot();
657#endif
Roman Zippelc28bda22007-05-01 22:32:36 +0200658 NCR5380_init(instance, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659
660 if (IS_A_TT()) {
661
662 /* This int is actually "pseudo-slow", i.e. it acts like a slow
663 * interrupt after having cleared the pending flag for the DMA
664 * interrupt. */
665 if (request_irq(IRQ_TT_MFP_SCSI, scsi_tt_intr, IRQ_TYPE_SLOW,
Jeff Garzik1e641662007-11-11 19:52:05 -0500666 "SCSI NCR5380", instance)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667 printk(KERN_ERR "atari_scsi_detect: cannot allocate irq %d, aborting",IRQ_TT_MFP_SCSI);
668 scsi_unregister(atari_scsi_host);
669 atari_stram_free(atari_dma_buffer);
670 atari_dma_buffer = 0;
671 return 0;
672 }
673 tt_mfp.active_edge |= 0x80; /* SCSI int on L->H */
674#ifdef REAL_DMA
675 tt_scsi_dma.dma_ctrl = 0;
676 atari_dma_residual = 0;
Adrian Bunk29c8a242008-10-13 21:58:59 +0200677
678 if (MACH_IS_MEDUSA) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700679 /* While the read overruns (described by Drew Eckhardt in
680 * NCR5380.c) never happened on TTs, they do in fact on the Medusa
681 * (This was the cause why SCSI didn't work right for so long
682 * there.) Since handling the overruns slows down a bit, I turned
683 * the #ifdef's into a runtime condition.
684 *
685 * In principle it should be sufficient to do max. 1 byte with
686 * PIO, but there is another problem on the Medusa with the DMA
687 * rest data register. So 'atari_read_overruns' is currently set
688 * to 4 to avoid having transfers that aren't a multiple of 4. If
689 * the rest data bug is fixed, this can be lowered to 1.
690 */
691 atari_read_overruns = 4;
Roman Zippelc28bda22007-05-01 22:32:36 +0200692 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693#endif /*REAL_DMA*/
Roman Zippelc28bda22007-05-01 22:32:36 +0200694 } else { /* ! IS_A_TT */
695
Linus Torvalds1da177e2005-04-16 15:20:36 -0700696 /* Nothing to do for the interrupt: the ST-DMA is initialized
697 * already by atari_init_INTS()
698 */
699
700#ifdef REAL_DMA
701 atari_dma_residual = 0;
702 atari_dma_active = 0;
703 atari_dma_stram_mask = (ATARIHW_PRESENT(EXTD_DMA) ? 0x00000000
704 : 0xff000000);
705#endif
706 }
707
708 printk(KERN_INFO "scsi%d: options CAN_QUEUE=%d CMD_PER_LUN=%d SCAT-GAT=%d "
709#ifdef SUPPORT_TAGS
710 "TAGGED-QUEUING=%s "
711#endif
712 "HOSTID=%d",
713 instance->host_no, instance->hostt->can_queue,
714 instance->hostt->cmd_per_lun,
715 instance->hostt->sg_tablesize,
716#ifdef SUPPORT_TAGS
717 setup_use_tagged_queuing ? "yes" : "no",
718#endif
719 instance->hostt->this_id );
Roman Zippelc28bda22007-05-01 22:32:36 +0200720 NCR5380_print_options(instance);
721 printk("\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700722
723 called = 1;
Roman Zippelc28bda22007-05-01 22:32:36 +0200724 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700725}
726
Geert Uytterhoeven107b5d52011-06-12 20:48:33 +0200727static int atari_scsi_release(struct Scsi_Host *sh)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728{
729 if (IS_A_TT())
Jeff Garzik1e641662007-11-11 19:52:05 -0500730 free_irq(IRQ_TT_MFP_SCSI, sh);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731 if (atari_dma_buffer)
Roman Zippelc28bda22007-05-01 22:32:36 +0200732 atari_stram_free(atari_dma_buffer);
Geert Uytterhoeven6323e4f2011-06-13 20:39:15 +0200733 NCR5380_exit(sh);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700734 return 1;
735}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736
Geert Uytterhoeven7b54e432012-03-18 11:54:40 +0100737#ifndef MODULE
738static int __init atari_scsi_setup(char *str)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700739{
740 /* Format of atascsi parameter is:
741 * atascsi=<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
742 * Defaults depend on TT or Falcon, hostid determined at run time.
743 * Negative values mean don't change.
744 */
Geert Uytterhoeven7b54e432012-03-18 11:54:40 +0100745 int ints[6];
746
747 get_options(str, ARRAY_SIZE(ints), ints);
Roman Zippelc28bda22007-05-01 22:32:36 +0200748
Linus Torvalds1da177e2005-04-16 15:20:36 -0700749 if (ints[0] < 1) {
Roman Zippelc28bda22007-05-01 22:32:36 +0200750 printk("atari_scsi_setup: no arguments!\n");
Geert Uytterhoeven7b54e432012-03-18 11:54:40 +0100751 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700752 }
753
754 if (ints[0] >= 1) {
755 if (ints[1] > 0)
756 /* no limits on this, just > 0 */
757 setup_can_queue = ints[1];
758 }
759 if (ints[0] >= 2) {
760 if (ints[2] > 0)
761 setup_cmd_per_lun = ints[2];
762 }
763 if (ints[0] >= 3) {
764 if (ints[3] >= 0) {
765 setup_sg_tablesize = ints[3];
766 /* Must be <= SG_ALL (255) */
767 if (setup_sg_tablesize > SG_ALL)
768 setup_sg_tablesize = SG_ALL;
769 }
770 }
771 if (ints[0] >= 4) {
772 /* Must be between 0 and 7 */
773 if (ints[4] >= 0 && ints[4] <= 7)
774 setup_hostid = ints[4];
775 else if (ints[4] > 7)
Roman Zippelc28bda22007-05-01 22:32:36 +0200776 printk("atari_scsi_setup: invalid host ID %d !\n", ints[4]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777 }
778#ifdef SUPPORT_TAGS
779 if (ints[0] >= 5) {
780 if (ints[5] >= 0)
781 setup_use_tagged_queuing = !!ints[5];
782 }
783#endif
Geert Uytterhoeven7b54e432012-03-18 11:54:40 +0100784
785 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786}
787
Geert Uytterhoeven7b54e432012-03-18 11:54:40 +0100788__setup("atascsi=", atari_scsi_setup);
789#endif /* !MODULE */
790
Geert Uytterhoeven107b5d52011-06-12 20:48:33 +0200791static int atari_scsi_bus_reset(Scsi_Cmnd *cmd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700792{
Roman Zippelc28bda22007-05-01 22:32:36 +0200793 int rv;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700794 struct NCR5380_hostdata *hostdata =
795 (struct NCR5380_hostdata *)cmd->device->host->hostdata;
796
797 /* For doing the reset, SCSI interrupts must be disabled first,
798 * since the 5380 raises its IRQ line while _RST is active and we
799 * can't disable interrupts completely, since we need the timer.
800 */
801 /* And abort a maybe active DMA transfer */
802 if (IS_A_TT()) {
Roman Zippelc28bda22007-05-01 22:32:36 +0200803 atari_turnoff_irq(IRQ_TT_MFP_SCSI);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700804#ifdef REAL_DMA
805 tt_scsi_dma.dma_ctrl = 0;
806#endif /* REAL_DMA */
Roman Zippelc28bda22007-05-01 22:32:36 +0200807 } else {
808 atari_turnoff_irq(IRQ_MFP_FSCSI);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700809#ifdef REAL_DMA
810 st_dma.dma_mode_status = 0x90;
811 atari_dma_active = 0;
812 atari_dma_orig_addr = NULL;
813#endif /* REAL_DMA */
814 }
815
816 rv = NCR5380_bus_reset(cmd);
817
818 /* Re-enable ints */
819 if (IS_A_TT()) {
Roman Zippelc28bda22007-05-01 22:32:36 +0200820 atari_turnon_irq(IRQ_TT_MFP_SCSI);
821 } else {
822 atari_turnon_irq(IRQ_MFP_FSCSI);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700823 }
824 if ((rv & SCSI_RESET_ACTION) == SCSI_RESET_SUCCESS)
825 falcon_release_lock_if_possible(hostdata);
826
Roman Zippelc28bda22007-05-01 22:32:36 +0200827 return rv;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700828}
829
Roman Zippelc28bda22007-05-01 22:32:36 +0200830
Linus Torvalds1da177e2005-04-16 15:20:36 -0700831#ifdef CONFIG_ATARI_SCSI_RESET_BOOT
832static void __init atari_scsi_reset_boot(void)
833{
834 unsigned long end;
Roman Zippelc28bda22007-05-01 22:32:36 +0200835
Linus Torvalds1da177e2005-04-16 15:20:36 -0700836 /*
837 * Do a SCSI reset to clean up the bus during initialization. No messing
838 * with the queues, interrupts, or locks necessary here.
839 */
840
Roman Zippelc28bda22007-05-01 22:32:36 +0200841 printk("Atari SCSI: resetting the SCSI bus...");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700842
843 /* get in phase */
Roman Zippelc28bda22007-05-01 22:32:36 +0200844 NCR5380_write(TARGET_COMMAND_REG,
845 PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG)));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700846
847 /* assert RST */
Roman Zippelc28bda22007-05-01 22:32:36 +0200848 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700849 /* The min. reset hold time is 25us, so 40us should be enough */
Roman Zippelc28bda22007-05-01 22:32:36 +0200850 udelay(50);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700851 /* reset RST and interrupt */
Roman Zippelc28bda22007-05-01 22:32:36 +0200852 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
853 NCR5380_read(RESET_PARITY_INTERRUPT_REG);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700854
855 end = jiffies + AFTER_RESET_DELAY;
856 while (time_before(jiffies, end))
857 barrier();
858
Roman Zippelc28bda22007-05-01 22:32:36 +0200859 printk(" done\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700860}
861#endif
862
863
Geert Uytterhoeven107b5d52011-06-12 20:48:33 +0200864static const char *atari_scsi_info(struct Scsi_Host *host)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700865{
866 /* atari_scsi_detect() is verbose enough... */
867 static const char string[] = "Atari native SCSI";
868 return string;
869}
870
871
872#if defined(REAL_DMA)
873
Geert Uytterhoeven107b5d52011-06-12 20:48:33 +0200874static unsigned long atari_scsi_dma_setup(struct Scsi_Host *instance,
875 void *data, unsigned long count,
876 int dir)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700877{
Roman Zippelc28bda22007-05-01 22:32:36 +0200878 unsigned long addr = virt_to_phys(data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700879
880 DMA_PRINTK("scsi%d: setting up dma, data = %p, phys = %lx, count = %ld, "
881 "dir = %d\n", instance->host_no, data, addr, count, dir);
882
883 if (!IS_A_TT() && !STRAM_ADDR(addr)) {
884 /* If we have a non-DMAable address on a Falcon, use the dribble
885 * buffer; 'orig_addr' != 0 in the read case tells the interrupt
886 * handler to copy data from the dribble buffer to the originally
887 * wanted address.
888 */
889 if (dir)
Roman Zippelc28bda22007-05-01 22:32:36 +0200890 memcpy(atari_dma_buffer, data, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700891 else
892 atari_dma_orig_addr = data;
893 addr = atari_dma_phys_buffer;
894 }
Roman Zippelc28bda22007-05-01 22:32:36 +0200895
Linus Torvalds1da177e2005-04-16 15:20:36 -0700896 atari_dma_startaddr = addr; /* Needed for calculating residual later. */
Roman Zippelc28bda22007-05-01 22:32:36 +0200897
Linus Torvalds1da177e2005-04-16 15:20:36 -0700898 /* Cache cleanup stuff: On writes, push any dirty cache out before sending
899 * it to the peripheral. (Must be done before DMA setup, since at least
900 * the ST-DMA begins to fill internal buffers right after setup. For
901 * reads, invalidate any cache, may be altered after DMA without CPU
902 * knowledge.
Roman Zippelc28bda22007-05-01 22:32:36 +0200903 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700904 * ++roman: For the Medusa, there's no need at all for that cache stuff,
905 * because the hardware does bus snooping (fine!).
906 */
Roman Zippelc28bda22007-05-01 22:32:36 +0200907 dma_cache_maintenance(addr, count, dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700908
909 if (count == 0)
910 printk(KERN_NOTICE "SCSI warning: DMA programmed for 0 bytes !\n");
911
912 if (IS_A_TT()) {
913 tt_scsi_dma.dma_ctrl = dir;
Roman Zippelc28bda22007-05-01 22:32:36 +0200914 SCSI_DMA_WRITE_P(dma_addr, addr);
915 SCSI_DMA_WRITE_P(dma_cnt, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700916 tt_scsi_dma.dma_ctrl = dir | 2;
Roman Zippelc28bda22007-05-01 22:32:36 +0200917 } else { /* ! IS_A_TT */
918
Linus Torvalds1da177e2005-04-16 15:20:36 -0700919 /* set address */
Roman Zippelc28bda22007-05-01 22:32:36 +0200920 SCSI_DMA_SETADR(addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700921
922 /* toggle direction bit to clear FIFO and set DMA direction */
923 dir <<= 8;
924 st_dma.dma_mode_status = 0x90 | dir;
925 st_dma.dma_mode_status = 0x90 | (dir ^ 0x100);
926 st_dma.dma_mode_status = 0x90 | dir;
927 udelay(40);
928 /* On writes, round up the transfer length to the next multiple of 512
929 * (see also comment at atari_dma_xfer_len()). */
930 st_dma.fdc_acces_seccount = (count + (dir ? 511 : 0)) >> 9;
931 udelay(40);
932 st_dma.dma_mode_status = 0x10 | dir;
933 udelay(40);
934 /* need not restore value of dir, only boolean value is tested */
935 atari_dma_active = 1;
936 }
937
Roman Zippelc28bda22007-05-01 22:32:36 +0200938 return count;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700939}
940
941
Roman Zippelc28bda22007-05-01 22:32:36 +0200942static long atari_scsi_dma_residual(struct Scsi_Host *instance)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700943{
Roman Zippelc28bda22007-05-01 22:32:36 +0200944 return atari_dma_residual;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700945}
946
947
948#define CMD_SURELY_BLOCK_MODE 0
949#define CMD_SURELY_BYTE_MODE 1
950#define CMD_MODE_UNKNOWN 2
951
Roman Zippelc28bda22007-05-01 22:32:36 +0200952static int falcon_classify_cmd(Scsi_Cmnd *cmd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700953{
954 unsigned char opcode = cmd->cmnd[0];
Roman Zippelc28bda22007-05-01 22:32:36 +0200955
Linus Torvalds1da177e2005-04-16 15:20:36 -0700956 if (opcode == READ_DEFECT_DATA || opcode == READ_LONG ||
Roman Zippelc28bda22007-05-01 22:32:36 +0200957 opcode == READ_BUFFER)
958 return CMD_SURELY_BYTE_MODE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700959 else if (opcode == READ_6 || opcode == READ_10 ||
960 opcode == 0xa8 /* READ_12 */ || opcode == READ_REVERSE ||
961 opcode == RECOVER_BUFFERED_DATA) {
962 /* In case of a sequential-access target (tape), special care is
963 * needed here: The transfer is block-mode only if the 'fixed' bit is
964 * set! */
965 if (cmd->device->type == TYPE_TAPE && !(cmd->cmnd[1] & 1))
Roman Zippelc28bda22007-05-01 22:32:36 +0200966 return CMD_SURELY_BYTE_MODE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700967 else
Roman Zippelc28bda22007-05-01 22:32:36 +0200968 return CMD_SURELY_BLOCK_MODE;
969 } else
970 return CMD_MODE_UNKNOWN;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700971}
972
973
974/* This function calculates the number of bytes that can be transferred via
975 * DMA. On the TT, this is arbitrary, but on the Falcon we have to use the
976 * ST-DMA chip. There are only multiples of 512 bytes possible and max.
977 * 255*512 bytes :-( This means also, that defining READ_OVERRUNS is not
978 * possible on the Falcon, since that would require to program the DMA for
979 * n*512 - atari_read_overrun bytes. But it seems that the Falcon doesn't have
980 * the overrun problem, so this question is academic :-)
981 */
982
Roman Zippelc28bda22007-05-01 22:32:36 +0200983static unsigned long atari_dma_xfer_len(unsigned long wanted_len,
984 Scsi_Cmnd *cmd, int write_flag)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700985{
986 unsigned long possible_len, limit;
Adrian Bunk29c8a242008-10-13 21:58:59 +0200987
Linus Torvalds1da177e2005-04-16 15:20:36 -0700988 if (IS_A_TT())
989 /* TT SCSI DMA can transfer arbitrary #bytes */
Roman Zippelc28bda22007-05-01 22:32:36 +0200990 return wanted_len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700991
992 /* ST DMA chip is stupid -- only multiples of 512 bytes! (and max.
993 * 255*512 bytes, but this should be enough)
994 *
995 * ++roman: Aaargl! Another Falcon-SCSI problem... There are some commands
996 * that return a number of bytes which cannot be known beforehand. In this
997 * case, the given transfer length is an "allocation length". Now it
998 * can happen that this allocation length is a multiple of 512 bytes and
999 * the DMA is used. But if not n*512 bytes really arrive, some input data
1000 * will be lost in the ST-DMA's FIFO :-( Thus, we have to distinguish
1001 * between commands that do block transfers and those that do byte
1002 * transfers. But this isn't easy... there are lots of vendor specific
1003 * commands, and the user can issue any command via the
1004 * SCSI_IOCTL_SEND_COMMAND.
1005 *
1006 * The solution: We classify SCSI commands in 1) surely block-mode cmd.s,
1007 * 2) surely byte-mode cmd.s and 3) cmd.s with unknown mode. In case 1)
1008 * and 3), the thing to do is obvious: allow any number of blocks via DMA
1009 * or none. In case 2), we apply some heuristic: Byte mode is assumed if
1010 * the transfer (allocation) length is < 1024, hoping that no cmd. not
1011 * explicitly known as byte mode have such big allocation lengths...
1012 * BTW, all the discussion above applies only to reads. DMA writes are
1013 * unproblematic anyways, since the targets aborts the transfer after
1014 * receiving a sufficient number of bytes.
1015 *
1016 * Another point: If the transfer is from/to an non-ST-RAM address, we
1017 * use the dribble buffer and thus can do only STRAM_BUFFER_SIZE bytes.
1018 */
1019
1020 if (write_flag) {
1021 /* Write operation can always use the DMA, but the transfer size must
1022 * be rounded up to the next multiple of 512 (atari_dma_setup() does
1023 * this).
1024 */
1025 possible_len = wanted_len;
Roman Zippelc28bda22007-05-01 22:32:36 +02001026 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001027 /* Read operations: if the wanted transfer length is not a multiple of
1028 * 512, we cannot use DMA, since the ST-DMA cannot split transfers
1029 * (no interrupt on DMA finished!)
1030 */
1031 if (wanted_len & 0x1ff)
1032 possible_len = 0;
1033 else {
1034 /* Now classify the command (see above) and decide whether it is
1035 * allowed to do DMA at all */
Roman Zippelc28bda22007-05-01 22:32:36 +02001036 switch (falcon_classify_cmd(cmd)) {
1037 case CMD_SURELY_BLOCK_MODE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001038 possible_len = wanted_len;
1039 break;
Roman Zippelc28bda22007-05-01 22:32:36 +02001040 case CMD_SURELY_BYTE_MODE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001041 possible_len = 0; /* DMA prohibited */
1042 break;
Roman Zippelc28bda22007-05-01 22:32:36 +02001043 case CMD_MODE_UNKNOWN:
1044 default:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001045 /* For unknown commands assume block transfers if the transfer
1046 * size/allocation length is >= 1024 */
1047 possible_len = (wanted_len < 1024) ? 0 : wanted_len;
1048 break;
1049 }
1050 }
1051 }
Roman Zippelc28bda22007-05-01 22:32:36 +02001052
Linus Torvalds1da177e2005-04-16 15:20:36 -07001053 /* Last step: apply the hard limit on DMA transfers */
Roman Zippelc28bda22007-05-01 22:32:36 +02001054 limit = (atari_dma_buffer && !STRAM_ADDR(virt_to_phys(cmd->SCp.ptr))) ?
Linus Torvalds1da177e2005-04-16 15:20:36 -07001055 STRAM_BUFFER_SIZE : 255*512;
1056 if (possible_len > limit)
1057 possible_len = limit;
1058
1059 if (possible_len != wanted_len)
1060 DMA_PRINTK("Sorry, must cut DMA transfer size to %ld bytes "
1061 "instead of %ld\n", possible_len, wanted_len);
1062
Roman Zippelc28bda22007-05-01 22:32:36 +02001063 return possible_len;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001064}
1065
1066
1067#endif /* REAL_DMA */
1068
1069
1070/* NCR5380 register access functions
1071 *
1072 * There are separate functions for TT and Falcon, because the access
1073 * methods are quite different. The calling macros NCR5380_read and
1074 * NCR5380_write call these functions via function pointers.
1075 */
1076
Roman Zippelc28bda22007-05-01 22:32:36 +02001077static unsigned char atari_scsi_tt_reg_read(unsigned char reg)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001078{
Roman Zippelc28bda22007-05-01 22:32:36 +02001079 return tt_scsi_regp[reg * 2];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001080}
1081
Roman Zippelc28bda22007-05-01 22:32:36 +02001082static void atari_scsi_tt_reg_write(unsigned char reg, unsigned char value)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001083{
1084 tt_scsi_regp[reg * 2] = value;
1085}
1086
Roman Zippelc28bda22007-05-01 22:32:36 +02001087static unsigned char atari_scsi_falcon_reg_read(unsigned char reg)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001088{
1089 dma_wd.dma_mode_status= (u_short)(0x88 + reg);
Roman Zippelc28bda22007-05-01 22:32:36 +02001090 return (u_char)dma_wd.fdc_acces_seccount;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001091}
1092
Roman Zippelc28bda22007-05-01 22:32:36 +02001093static void atari_scsi_falcon_reg_write(unsigned char reg, unsigned char value)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001094{
1095 dma_wd.dma_mode_status = (u_short)(0x88 + reg);
1096 dma_wd.fdc_acces_seccount = (u_short)value;
1097}
1098
1099
1100#include "atari_NCR5380.c"
1101
Christoph Hellwigd0be4a7d2005-10-31 18:31:40 +01001102static struct scsi_host_template driver_template = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001103 .proc_info = atari_scsi_proc_info,
1104 .name = "Atari native SCSI",
1105 .detect = atari_scsi_detect,
1106 .release = atari_scsi_release,
1107 .info = atari_scsi_info,
1108 .queuecommand = atari_scsi_queue_command,
1109 .eh_abort_handler = atari_scsi_abort,
1110 .eh_bus_reset_handler = atari_scsi_bus_reset,
1111 .can_queue = 0, /* initialized at run-time */
1112 .this_id = 0, /* initialized at run-time */
1113 .sg_tablesize = 0, /* initialized at run-time */
1114 .cmd_per_lun = 0, /* initialized at run-time */
1115 .use_clustering = DISABLE_CLUSTERING
1116};
1117
1118
1119#include "scsi_module.c"
1120
1121MODULE_LICENSE("GPL");