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1da177e4 LT |
1 | /* |
2 | * atari_scsi.c -- Device dependent functions for the Atari generic SCSI port | |
3 | * | |
4 | * Copyright 1994 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de> | |
5 | * | |
6 | * Loosely based on the work of Robert De Vries' team and added: | |
7 | * - working real DMA | |
8 | * - Falcon support (untested yet!) ++bjoern fixed and now it works | |
9 | * - lots of extensions and bug fixes. | |
10 | * | |
11 | * This file is subject to the terms and conditions of the GNU General Public | |
12 | * License. See the file COPYING in the main directory of this archive | |
13 | * for more details. | |
14 | * | |
15 | */ | |
16 | ||
17 | ||
18 | /**************************************************************************/ | |
19 | /* */ | |
20 | /* Notes for Falcon SCSI: */ | |
21 | /* ---------------------- */ | |
22 | /* */ | |
23 | /* Since the Falcon SCSI uses the ST-DMA chip, that is shared among */ | |
24 | /* several device drivers, locking and unlocking the access to this */ | |
25 | /* chip is required. But locking is not possible from an interrupt, */ | |
26 | /* since it puts the process to sleep if the lock is not available. */ | |
27 | /* This prevents "late" locking of the DMA chip, i.e. locking it just */ | |
28 | /* before using it, since in case of disconnection-reconnection */ | |
29 | /* commands, the DMA is started from the reselection interrupt. */ | |
30 | /* */ | |
31 | /* Two possible schemes for ST-DMA-locking would be: */ | |
32 | /* 1) The lock is taken for each command separately and disconnecting */ | |
33 | /* is forbidden (i.e. can_queue = 1). */ | |
34 | /* 2) The DMA chip is locked when the first command comes in and */ | |
35 | /* released when the last command is finished and all queues are */ | |
36 | /* empty. */ | |
37 | /* The first alternative would result in bad performance, since the */ | |
38 | /* interleaving of commands would not be used. The second is unfair to */ | |
39 | /* other drivers using the ST-DMA, because the queues will seldom be */ | |
40 | /* totally empty if there is a lot of disk traffic. */ | |
41 | /* */ | |
42 | /* For this reasons I decided to employ a more elaborate scheme: */ | |
43 | /* - First, we give up the lock every time we can (for fairness), this */ | |
44 | /* means every time a command finishes and there are no other commands */ | |
45 | /* on the disconnected queue. */ | |
46 | /* - If there are others waiting to lock the DMA chip, we stop */ | |
47 | /* issuing commands, i.e. moving them onto the issue queue. */ | |
48 | /* Because of that, the disconnected queue will run empty in a */ | |
49 | /* while. Instead we go to sleep on a 'fairness_queue'. */ | |
50 | /* - If the lock is released, all processes waiting on the fairness */ | |
51 | /* queue will be woken. The first of them tries to re-lock the DMA, */ | |
52 | /* the others wait for the first to finish this task. After that, */ | |
53 | /* they can all run on and do their commands... */ | |
54 | /* This sounds complicated (and it is it :-(), but it seems to be a */ | |
55 | /* good compromise between fairness and performance: As long as no one */ | |
56 | /* else wants to work with the ST-DMA chip, SCSI can go along as */ | |
57 | /* usual. If now someone else comes, this behaviour is changed to a */ | |
58 | /* "fairness mode": just already initiated commands are finished and */ | |
59 | /* then the lock is released. The other one waiting will probably win */ | |
60 | /* the race for locking the DMA, since it was waiting for longer. And */ | |
61 | /* after it has finished, SCSI can go ahead again. Finally: I hope I */ | |
62 | /* have not produced any deadlock possibilities! */ | |
63 | /* */ | |
64 | /**************************************************************************/ | |
65 | ||
66 | ||
67 | ||
1da177e4 LT |
68 | #include <linux/module.h> |
69 | ||
70 | #define NDEBUG (0) | |
71 | ||
3130d905 RZ |
72 | #define NDEBUG_ABORT 0x00100000 |
73 | #define NDEBUG_TAGS 0x00200000 | |
74 | #define NDEBUG_MERGING 0x00400000 | |
1da177e4 LT |
75 | |
76 | #define AUTOSENSE | |
77 | /* For the Atari version, use only polled IO or REAL_DMA */ | |
78 | #define REAL_DMA | |
79 | /* Support tagged queuing? (on devices that are able to... :-) */ | |
80 | #define SUPPORT_TAGS | |
81 | #define MAX_TAGS 32 | |
82 | ||
83 | #include <linux/types.h> | |
84 | #include <linux/stddef.h> | |
85 | #include <linux/ctype.h> | |
86 | #include <linux/delay.h> | |
87 | #include <linux/mm.h> | |
88 | #include <linux/blkdev.h> | |
1da177e4 LT |
89 | #include <linux/interrupt.h> |
90 | #include <linux/init.h> | |
91 | #include <linux/nvram.h> | |
92 | #include <linux/bitops.h> | |
eff9cf8d | 93 | #include <linux/wait.h> |
1da177e4 LT |
94 | |
95 | #include <asm/setup.h> | |
96 | #include <asm/atarihw.h> | |
97 | #include <asm/atariints.h> | |
98 | #include <asm/page.h> | |
99 | #include <asm/pgtable.h> | |
100 | #include <asm/irq.h> | |
101 | #include <asm/traps.h> | |
102 | ||
103 | #include "scsi.h" | |
104 | #include <scsi/scsi_host.h> | |
105 | #include "atari_scsi.h" | |
106 | #include "NCR5380.h" | |
107 | #include <asm/atari_stdma.h> | |
108 | #include <asm/atari_stram.h> | |
109 | #include <asm/io.h> | |
110 | ||
111 | #include <linux/stat.h> | |
112 | ||
113 | #define IS_A_TT() ATARIHW_PRESENT(TT_SCSI) | |
114 | ||
115 | #define SCSI_DMA_WRITE_P(elt,val) \ | |
116 | do { \ | |
117 | unsigned long v = val; \ | |
118 | tt_scsi_dma.elt##_lo = v & 0xff; \ | |
119 | v >>= 8; \ | |
120 | tt_scsi_dma.elt##_lmd = v & 0xff; \ | |
121 | v >>= 8; \ | |
122 | tt_scsi_dma.elt##_hmd = v & 0xff; \ | |
123 | v >>= 8; \ | |
124 | tt_scsi_dma.elt##_hi = v & 0xff; \ | |
125 | } while(0) | |
126 | ||
127 | #define SCSI_DMA_READ_P(elt) \ | |
128 | (((((((unsigned long)tt_scsi_dma.elt##_hi << 8) | \ | |
129 | (unsigned long)tt_scsi_dma.elt##_hmd) << 8) | \ | |
130 | (unsigned long)tt_scsi_dma.elt##_lmd) << 8) | \ | |
131 | (unsigned long)tt_scsi_dma.elt##_lo) | |
132 | ||
133 | ||
134 | static inline void SCSI_DMA_SETADR(unsigned long adr) | |
135 | { | |
136 | st_dma.dma_lo = (unsigned char)adr; | |
137 | MFPDELAY(); | |
138 | adr >>= 8; | |
139 | st_dma.dma_md = (unsigned char)adr; | |
140 | MFPDELAY(); | |
141 | adr >>= 8; | |
142 | st_dma.dma_hi = (unsigned char)adr; | |
143 | MFPDELAY(); | |
144 | } | |
145 | ||
146 | static inline unsigned long SCSI_DMA_GETADR(void) | |
147 | { | |
148 | unsigned long adr; | |
149 | adr = st_dma.dma_lo; | |
150 | MFPDELAY(); | |
151 | adr |= (st_dma.dma_md & 0xff) << 8; | |
152 | MFPDELAY(); | |
153 | adr |= (st_dma.dma_hi & 0xff) << 16; | |
154 | MFPDELAY(); | |
155 | return adr; | |
156 | } | |
157 | ||
158 | static inline void ENABLE_IRQ(void) | |
159 | { | |
160 | if (IS_A_TT()) | |
161 | atari_enable_irq(IRQ_TT_MFP_SCSI); | |
162 | else | |
163 | atari_enable_irq(IRQ_MFP_FSCSI); | |
164 | } | |
165 | ||
166 | static inline void DISABLE_IRQ(void) | |
167 | { | |
168 | if (IS_A_TT()) | |
169 | atari_disable_irq(IRQ_TT_MFP_SCSI); | |
170 | else | |
171 | atari_disable_irq(IRQ_MFP_FSCSI); | |
172 | } | |
173 | ||
174 | ||
175 | #define HOSTDATA_DMALEN (((struct NCR5380_hostdata *) \ | |
176 | (atari_scsi_host->hostdata))->dma_len) | |
177 | ||
178 | /* Time (in jiffies) to wait after a reset; the SCSI standard calls for 250ms, | |
179 | * we usually do 0.5s to be on the safe side. But Toshiba CD-ROMs once more | |
180 | * need ten times the standard value... */ | |
181 | #ifndef CONFIG_ATARI_SCSI_TOSHIBA_DELAY | |
182 | #define AFTER_RESET_DELAY (HZ/2) | |
183 | #else | |
184 | #define AFTER_RESET_DELAY (5*HZ/2) | |
185 | #endif | |
186 | ||
187 | /***************************** Prototypes *****************************/ | |
188 | ||
189 | #ifdef REAL_DMA | |
c28bda25 RZ |
190 | static int scsi_dma_is_ignored_buserr(unsigned char dma_stat); |
191 | static void atari_scsi_fetch_restbytes(void); | |
192 | static long atari_scsi_dma_residual(struct Scsi_Host *instance); | |
193 | static int falcon_classify_cmd(Scsi_Cmnd *cmd); | |
194 | static unsigned long atari_dma_xfer_len(unsigned long wanted_len, | |
195 | Scsi_Cmnd *cmd, int write_flag); | |
1da177e4 | 196 | #endif |
c28bda25 RZ |
197 | static irqreturn_t scsi_tt_intr(int irq, void *dummy); |
198 | static irqreturn_t scsi_falcon_intr(int irq, void *dummy); | |
199 | static void falcon_release_lock_if_possible(struct NCR5380_hostdata *hostdata); | |
200 | static void falcon_get_lock(void); | |
1da177e4 | 201 | #ifdef CONFIG_ATARI_SCSI_RESET_BOOT |
c28bda25 | 202 | static void atari_scsi_reset_boot(void); |
1da177e4 | 203 | #endif |
c28bda25 RZ |
204 | static unsigned char atari_scsi_tt_reg_read(unsigned char reg); |
205 | static void atari_scsi_tt_reg_write(unsigned char reg, unsigned char value); | |
206 | static unsigned char atari_scsi_falcon_reg_read(unsigned char reg); | |
207 | static void atari_scsi_falcon_reg_write(unsigned char reg, unsigned char value); | |
1da177e4 LT |
208 | |
209 | /************************* End of Prototypes **************************/ | |
210 | ||
211 | ||
c28bda25 RZ |
212 | static struct Scsi_Host *atari_scsi_host; |
213 | static unsigned char (*atari_scsi_reg_read)(unsigned char reg); | |
214 | static void (*atari_scsi_reg_write)(unsigned char reg, unsigned char value); | |
1da177e4 LT |
215 | |
216 | #ifdef REAL_DMA | |
217 | static unsigned long atari_dma_residual, atari_dma_startaddr; | |
218 | static short atari_dma_active; | |
219 | /* pointer to the dribble buffer */ | |
c28bda25 | 220 | static char *atari_dma_buffer; |
1da177e4 LT |
221 | /* precalculated physical address of the dribble buffer */ |
222 | static unsigned long atari_dma_phys_buffer; | |
223 | /* != 0 tells the Falcon int handler to copy data from the dribble buffer */ | |
224 | static char *atari_dma_orig_addr; | |
225 | /* size of the dribble buffer; 4k seems enough, since the Falcon cannot use | |
226 | * scatter-gather anyway, so most transfers are 1024 byte only. In the rare | |
227 | * cases where requests to physical contiguous buffers have been merged, this | |
228 | * request is <= 4k (one page). So I don't think we have to split transfers | |
229 | * just due to this buffer size... | |
230 | */ | |
231 | #define STRAM_BUFFER_SIZE (4096) | |
232 | /* mask for address bits that can't be used with the ST-DMA */ | |
233 | static unsigned long atari_dma_stram_mask; | |
234 | #define STRAM_ADDR(a) (((a) & atari_dma_stram_mask) == 0) | |
235 | /* number of bytes to cut from a transfer to handle NCR overruns */ | |
c28bda25 | 236 | static int atari_read_overruns; |
1da177e4 LT |
237 | #endif |
238 | ||
239 | static int setup_can_queue = -1; | |
8d3b33f6 | 240 | module_param(setup_can_queue, int, 0); |
1da177e4 | 241 | static int setup_cmd_per_lun = -1; |
8d3b33f6 | 242 | module_param(setup_cmd_per_lun, int, 0); |
1da177e4 | 243 | static int setup_sg_tablesize = -1; |
8d3b33f6 | 244 | module_param(setup_sg_tablesize, int, 0); |
1da177e4 LT |
245 | #ifdef SUPPORT_TAGS |
246 | static int setup_use_tagged_queuing = -1; | |
8d3b33f6 | 247 | module_param(setup_use_tagged_queuing, int, 0); |
1da177e4 LT |
248 | #endif |
249 | static int setup_hostid = -1; | |
8d3b33f6 | 250 | module_param(setup_hostid, int, 0); |
1da177e4 LT |
251 | |
252 | ||
1da177e4 LT |
253 | #if defined(REAL_DMA) |
254 | ||
c28bda25 | 255 | static int scsi_dma_is_ignored_buserr(unsigned char dma_stat) |
1da177e4 LT |
256 | { |
257 | int i; | |
c28bda25 | 258 | unsigned long addr = SCSI_DMA_READ_P(dma_addr), end_addr; |
1da177e4 LT |
259 | |
260 | if (dma_stat & 0x01) { | |
261 | ||
262 | /* A bus error happens when DMA-ing from the last page of a | |
263 | * physical memory chunk (DMA prefetch!), but that doesn't hurt. | |
264 | * Check for this case: | |
265 | */ | |
c28bda25 RZ |
266 | |
267 | for (i = 0; i < m68k_num_memory; ++i) { | |
268 | end_addr = m68k_memory[i].addr + m68k_memory[i].size; | |
1da177e4 | 269 | if (end_addr <= addr && addr <= end_addr + 4) |
c28bda25 | 270 | return 1; |
1da177e4 LT |
271 | } |
272 | } | |
c28bda25 | 273 | return 0; |
1da177e4 LT |
274 | } |
275 | ||
276 | ||
277 | #if 0 | |
278 | /* Dead code... wasn't called anyway :-) and causes some trouble, because at | |
279 | * end-of-DMA, both SCSI ints are triggered simultaneously, so the NCR int has | |
280 | * to clear the DMA int pending bit before it allows other level 6 interrupts. | |
281 | */ | |
c28bda25 | 282 | static void scsi_dma_buserr(int irq, void *dummy) |
1da177e4 | 283 | { |
c28bda25 | 284 | unsigned char dma_stat = tt_scsi_dma.dma_ctrl; |
1da177e4 LT |
285 | |
286 | /* Don't do anything if a NCR interrupt is pending. Probably it's just | |
287 | * masked... */ | |
c28bda25 | 288 | if (atari_irq_pending(IRQ_TT_MFP_SCSI)) |
1da177e4 | 289 | return; |
c28bda25 | 290 | |
1da177e4 LT |
291 | printk("Bad SCSI DMA interrupt! dma_addr=0x%08lx dma_stat=%02x dma_cnt=%08lx\n", |
292 | SCSI_DMA_READ_P(dma_addr), dma_stat, SCSI_DMA_READ_P(dma_cnt)); | |
293 | if (dma_stat & 0x80) { | |
c28bda25 RZ |
294 | if (!scsi_dma_is_ignored_buserr(dma_stat)) |
295 | printk("SCSI DMA bus error -- bad DMA programming!\n"); | |
296 | } else { | |
1da177e4 LT |
297 | /* Under normal circumstances we never should get to this point, |
298 | * since both interrupts are triggered simultaneously and the 5380 | |
299 | * int has higher priority. When this irq is handled, that DMA | |
300 | * interrupt is cleared. So a warning message is printed here. | |
301 | */ | |
c28bda25 | 302 | printk("SCSI DMA intr ?? -- this shouldn't happen!\n"); |
1da177e4 LT |
303 | } |
304 | } | |
305 | #endif | |
306 | ||
307 | #endif | |
308 | ||
309 | ||
c28bda25 | 310 | static irqreturn_t scsi_tt_intr(int irq, void *dummy) |
1da177e4 LT |
311 | { |
312 | #ifdef REAL_DMA | |
313 | int dma_stat; | |
314 | ||
315 | dma_stat = tt_scsi_dma.dma_ctrl; | |
316 | ||
317 | INT_PRINTK("scsi%d: NCR5380 interrupt, DMA status = %02x\n", | |
318 | atari_scsi_host->host_no, dma_stat & 0xff); | |
319 | ||
320 | /* Look if it was the DMA that has interrupted: First possibility | |
321 | * is that a bus error occurred... | |
322 | */ | |
323 | if (dma_stat & 0x80) { | |
c28bda25 | 324 | if (!scsi_dma_is_ignored_buserr(dma_stat)) { |
1da177e4 LT |
325 | printk(KERN_ERR "SCSI DMA caused bus error near 0x%08lx\n", |
326 | SCSI_DMA_READ_P(dma_addr)); | |
327 | printk(KERN_CRIT "SCSI DMA bus error -- bad DMA programming!"); | |
328 | } | |
329 | } | |
330 | ||
331 | /* If the DMA is active but not finished, we have the case | |
332 | * that some other 5380 interrupt occurred within the DMA transfer. | |
333 | * This means we have residual bytes, if the desired end address | |
334 | * is not yet reached. Maybe we have to fetch some bytes from the | |
335 | * rest data register, too. The residual must be calculated from | |
336 | * the address pointer, not the counter register, because only the | |
337 | * addr reg counts bytes not yet written and pending in the rest | |
338 | * data reg! | |
339 | */ | |
340 | if ((dma_stat & 0x02) && !(dma_stat & 0x40)) { | |
c28bda25 | 341 | atari_dma_residual = HOSTDATA_DMALEN - (SCSI_DMA_READ_P(dma_addr) - atari_dma_startaddr); |
1da177e4 LT |
342 | |
343 | DMA_PRINTK("SCSI DMA: There are %ld residual bytes.\n", | |
344 | atari_dma_residual); | |
345 | ||
346 | if ((signed int)atari_dma_residual < 0) | |
347 | atari_dma_residual = 0; | |
348 | if ((dma_stat & 1) == 0) { | |
c28bda25 RZ |
349 | /* |
350 | * After read operations, we maybe have to | |
351 | * transport some rest bytes | |
352 | */ | |
1da177e4 | 353 | atari_scsi_fetch_restbytes(); |
c28bda25 RZ |
354 | } else { |
355 | /* | |
356 | * There seems to be a nasty bug in some SCSI-DMA/NCR | |
357 | * combinations: If a target disconnects while a write | |
358 | * operation is going on, the address register of the | |
359 | * DMA may be a few bytes farer than it actually read. | |
360 | * This is probably due to DMA prefetching and a delay | |
361 | * between DMA and NCR. Experiments showed that the | |
362 | * dma_addr is 9 bytes to high, but this could vary. | |
363 | * The problem is, that the residual is thus calculated | |
364 | * wrong and the next transfer will start behind where | |
365 | * it should. So we round up the residual to the next | |
366 | * multiple of a sector size, if it isn't already a | |
367 | * multiple and the originally expected transfer size | |
368 | * was. The latter condition is there to ensure that | |
369 | * the correction is taken only for "real" data | |
370 | * transfers and not for, e.g., the parameters of some | |
371 | * other command. These shouldn't disconnect anyway. | |
372 | */ | |
1da177e4 LT |
373 | if (atari_dma_residual & 0x1ff) { |
374 | DMA_PRINTK("SCSI DMA: DMA bug corrected, " | |
375 | "difference %ld bytes\n", | |
376 | 512 - (atari_dma_residual & 0x1ff)); | |
377 | atari_dma_residual = (atari_dma_residual + 511) & ~0x1ff; | |
378 | } | |
379 | } | |
380 | tt_scsi_dma.dma_ctrl = 0; | |
381 | } | |
382 | ||
383 | /* If the DMA is finished, fetch the rest bytes and turn it off */ | |
384 | if (dma_stat & 0x40) { | |
385 | atari_dma_residual = 0; | |
386 | if ((dma_stat & 1) == 0) | |
387 | atari_scsi_fetch_restbytes(); | |
388 | tt_scsi_dma.dma_ctrl = 0; | |
389 | } | |
390 | ||
391 | #endif /* REAL_DMA */ | |
c28bda25 | 392 | |
1e641664 | 393 | NCR5380_intr(irq, dummy); |
1da177e4 LT |
394 | |
395 | #if 0 | |
396 | /* To be sure the int is not masked */ | |
c28bda25 | 397 | atari_enable_irq(IRQ_TT_MFP_SCSI); |
1da177e4 LT |
398 | #endif |
399 | return IRQ_HANDLED; | |
400 | } | |
401 | ||
402 | ||
c28bda25 | 403 | static irqreturn_t scsi_falcon_intr(int irq, void *dummy) |
1da177e4 LT |
404 | { |
405 | #ifdef REAL_DMA | |
406 | int dma_stat; | |
407 | ||
408 | /* Turn off DMA and select sector counter register before | |
409 | * accessing the status register (Atari recommendation!) | |
410 | */ | |
411 | st_dma.dma_mode_status = 0x90; | |
412 | dma_stat = st_dma.dma_mode_status; | |
413 | ||
414 | /* Bit 0 indicates some error in the DMA process... don't know | |
415 | * what happened exactly (no further docu). | |
416 | */ | |
417 | if (!(dma_stat & 0x01)) { | |
418 | /* DMA error */ | |
419 | printk(KERN_CRIT "SCSI DMA error near 0x%08lx!\n", SCSI_DMA_GETADR()); | |
420 | } | |
421 | ||
422 | /* If the DMA was active, but now bit 1 is not clear, it is some | |
423 | * other 5380 interrupt that finishes the DMA transfer. We have to | |
424 | * calculate the number of residual bytes and give a warning if | |
425 | * bytes are stuck in the ST-DMA fifo (there's no way to reach them!) | |
426 | */ | |
427 | if (atari_dma_active && (dma_stat & 0x02)) { | |
c28bda25 | 428 | unsigned long transferred; |
1da177e4 LT |
429 | |
430 | transferred = SCSI_DMA_GETADR() - atari_dma_startaddr; | |
431 | /* The ST-DMA address is incremented in 2-byte steps, but the | |
432 | * data are written only in 16-byte chunks. If the number of | |
433 | * transferred bytes is not divisible by 16, the remainder is | |
434 | * lost somewhere in outer space. | |
435 | */ | |
436 | if (transferred & 15) | |
437 | printk(KERN_ERR "SCSI DMA error: %ld bytes lost in " | |
438 | "ST-DMA fifo\n", transferred & 15); | |
439 | ||
440 | atari_dma_residual = HOSTDATA_DMALEN - transferred; | |
441 | DMA_PRINTK("SCSI DMA: There are %ld residual bytes.\n", | |
442 | atari_dma_residual); | |
c28bda25 | 443 | } else |
1da177e4 LT |
444 | atari_dma_residual = 0; |
445 | atari_dma_active = 0; | |
446 | ||
447 | if (atari_dma_orig_addr) { | |
448 | /* If the dribble buffer was used on a read operation, copy the DMA-ed | |
449 | * data to the original destination address. | |
450 | */ | |
451 | memcpy(atari_dma_orig_addr, phys_to_virt(atari_dma_startaddr), | |
452 | HOSTDATA_DMALEN - atari_dma_residual); | |
453 | atari_dma_orig_addr = NULL; | |
454 | } | |
455 | ||
456 | #endif /* REAL_DMA */ | |
457 | ||
1e641664 | 458 | NCR5380_intr(irq, dummy); |
1da177e4 LT |
459 | return IRQ_HANDLED; |
460 | } | |
461 | ||
462 | ||
463 | #ifdef REAL_DMA | |
c28bda25 | 464 | static void atari_scsi_fetch_restbytes(void) |
1da177e4 LT |
465 | { |
466 | int nr; | |
467 | char *src, *dst; | |
468 | unsigned long phys_dst; | |
469 | ||
470 | /* fetch rest bytes in the DMA register */ | |
471 | phys_dst = SCSI_DMA_READ_P(dma_addr); | |
472 | nr = phys_dst & 3; | |
473 | if (nr) { | |
474 | /* there are 'nr' bytes left for the last long address | |
475 | before the DMA pointer */ | |
476 | phys_dst ^= nr; | |
477 | DMA_PRINTK("SCSI DMA: there are %d rest bytes for phys addr 0x%08lx", | |
478 | nr, phys_dst); | |
479 | /* The content of the DMA pointer is a physical address! */ | |
480 | dst = phys_to_virt(phys_dst); | |
481 | DMA_PRINTK(" = virt addr %p\n", dst); | |
482 | for (src = (char *)&tt_scsi_dma.dma_restdata; nr != 0; --nr) | |
483 | *dst++ = *src++; | |
484 | } | |
485 | } | |
486 | #endif /* REAL_DMA */ | |
487 | ||
488 | ||
489 | static int falcon_got_lock = 0; | |
490 | static DECLARE_WAIT_QUEUE_HEAD(falcon_fairness_wait); | |
491 | static int falcon_trying_lock = 0; | |
492 | static DECLARE_WAIT_QUEUE_HEAD(falcon_try_wait); | |
493 | static int falcon_dont_release = 0; | |
494 | ||
495 | /* This function releases the lock on the DMA chip if there is no | |
496 | * connected command and the disconnected queue is empty. On | |
497 | * releasing, instances of falcon_get_lock are awoken, that put | |
498 | * themselves to sleep for fairness. They can now try to get the lock | |
499 | * again (but others waiting longer more probably will win). | |
500 | */ | |
501 | ||
c28bda25 | 502 | static void falcon_release_lock_if_possible(struct NCR5380_hostdata *hostdata) |
1da177e4 LT |
503 | { |
504 | unsigned long flags; | |
c28bda25 RZ |
505 | |
506 | if (IS_A_TT()) | |
507 | return; | |
508 | ||
1da177e4 LT |
509 | local_irq_save(flags); |
510 | ||
c28bda25 RZ |
511 | if (falcon_got_lock && !hostdata->disconnected_queue && |
512 | !hostdata->issue_queue && !hostdata->connected) { | |
1da177e4 LT |
513 | |
514 | if (falcon_dont_release) { | |
515 | #if 0 | |
516 | printk("WARNING: Lock release not allowed. Ignored\n"); | |
517 | #endif | |
518 | local_irq_restore(flags); | |
519 | return; | |
520 | } | |
521 | falcon_got_lock = 0; | |
522 | stdma_release(); | |
c28bda25 | 523 | wake_up(&falcon_fairness_wait); |
1da177e4 LT |
524 | } |
525 | ||
526 | local_irq_restore(flags); | |
527 | } | |
528 | ||
529 | /* This function manages the locking of the ST-DMA. | |
530 | * If the DMA isn't locked already for SCSI, it tries to lock it by | |
531 | * calling stdma_lock(). But if the DMA is locked by the SCSI code and | |
532 | * there are other drivers waiting for the chip, we do not issue the | |
533 | * command immediately but wait on 'falcon_fairness_queue'. We will be | |
534 | * waked up when the DMA is unlocked by some SCSI interrupt. After that | |
535 | * we try to get the lock again. | |
536 | * But we must be prepared that more than one instance of | |
537 | * falcon_get_lock() is waiting on the fairness queue. They should not | |
538 | * try all at once to call stdma_lock(), one is enough! For that, the | |
539 | * first one sets 'falcon_trying_lock', others that see that variable | |
540 | * set wait on the queue 'falcon_try_wait'. | |
541 | * Complicated, complicated.... Sigh... | |
542 | */ | |
543 | ||
c28bda25 | 544 | static void falcon_get_lock(void) |
1da177e4 LT |
545 | { |
546 | unsigned long flags; | |
547 | ||
c28bda25 RZ |
548 | if (IS_A_TT()) |
549 | return; | |
1da177e4 LT |
550 | |
551 | local_irq_save(flags); | |
552 | ||
eff9cf8d AB |
553 | wait_event_cmd(falcon_fairness_wait, |
554 | in_interrupt() || !falcon_got_lock || !stdma_others_waiting(), | |
555 | local_irq_restore(flags), | |
556 | local_irq_save(flags)); | |
1da177e4 LT |
557 | |
558 | while (!falcon_got_lock) { | |
fb810d12 | 559 | if (in_irq()) |
c28bda25 | 560 | panic("Falcon SCSI hasn't ST-DMA lock in interrupt"); |
1da177e4 LT |
561 | if (!falcon_trying_lock) { |
562 | falcon_trying_lock = 1; | |
563 | stdma_lock(scsi_falcon_intr, NULL); | |
564 | falcon_got_lock = 1; | |
565 | falcon_trying_lock = 0; | |
c28bda25 RZ |
566 | wake_up(&falcon_try_wait); |
567 | } else { | |
eff9cf8d AB |
568 | wait_event_cmd(falcon_try_wait, |
569 | falcon_got_lock && !falcon_trying_lock, | |
570 | local_irq_restore(flags), | |
571 | local_irq_save(flags)); | |
1da177e4 | 572 | } |
c28bda25 | 573 | } |
1da177e4 LT |
574 | |
575 | local_irq_restore(flags); | |
576 | if (!falcon_got_lock) | |
577 | panic("Falcon SCSI: someone stole the lock :-(\n"); | |
578 | } | |
579 | ||
580 | ||
107b5d53 | 581 | static int __init atari_scsi_detect(struct scsi_host_template *host) |
1da177e4 LT |
582 | { |
583 | static int called = 0; | |
584 | struct Scsi_Host *instance; | |
585 | ||
586 | if (!MACH_IS_ATARI || | |
587 | (!ATARIHW_PRESENT(ST_SCSI) && !ATARIHW_PRESENT(TT_SCSI)) || | |
588 | called) | |
c28bda25 | 589 | return 0; |
1da177e4 LT |
590 | |
591 | host->proc_name = "Atari"; | |
592 | ||
593 | atari_scsi_reg_read = IS_A_TT() ? atari_scsi_tt_reg_read : | |
594 | atari_scsi_falcon_reg_read; | |
595 | atari_scsi_reg_write = IS_A_TT() ? atari_scsi_tt_reg_write : | |
596 | atari_scsi_falcon_reg_write; | |
597 | ||
598 | /* setup variables */ | |
599 | host->can_queue = | |
600 | (setup_can_queue > 0) ? setup_can_queue : | |
601 | IS_A_TT() ? ATARI_TT_CAN_QUEUE : ATARI_FALCON_CAN_QUEUE; | |
602 | host->cmd_per_lun = | |
603 | (setup_cmd_per_lun > 0) ? setup_cmd_per_lun : | |
604 | IS_A_TT() ? ATARI_TT_CMD_PER_LUN : ATARI_FALCON_CMD_PER_LUN; | |
605 | /* Force sg_tablesize to 0 on a Falcon! */ | |
606 | host->sg_tablesize = | |
607 | !IS_A_TT() ? ATARI_FALCON_SG_TABLESIZE : | |
608 | (setup_sg_tablesize >= 0) ? setup_sg_tablesize : ATARI_TT_SG_TABLESIZE; | |
609 | ||
610 | if (setup_hostid >= 0) | |
611 | host->this_id = setup_hostid; | |
612 | else { | |
613 | /* use 7 as default */ | |
614 | host->this_id = 7; | |
615 | /* Test if a host id is set in the NVRam */ | |
616 | if (ATARIHW_PRESENT(TT_CLK) && nvram_check_checksum()) { | |
617 | unsigned char b = nvram_read_byte( 14 ); | |
618 | /* Arbitration enabled? (for TOS) If yes, use configured host ID */ | |
619 | if (b & 0x80) | |
620 | host->this_id = b & 7; | |
621 | } | |
622 | } | |
623 | ||
624 | #ifdef SUPPORT_TAGS | |
625 | if (setup_use_tagged_queuing < 0) | |
626 | setup_use_tagged_queuing = DEFAULT_USE_TAGGED_QUEUING; | |
627 | #endif | |
628 | #ifdef REAL_DMA | |
629 | /* If running on a Falcon and if there's TT-Ram (i.e., more than one | |
630 | * memory block, since there's always ST-Ram in a Falcon), then allocate a | |
631 | * STRAM_BUFFER_SIZE byte dribble buffer for transfers from/to alternative | |
632 | * Ram. | |
633 | */ | |
634 | if (MACH_IS_ATARI && ATARIHW_PRESENT(ST_SCSI) && | |
635 | !ATARIHW_PRESENT(EXTD_DMA) && m68k_num_memory > 1) { | |
636 | atari_dma_buffer = atari_stram_alloc(STRAM_BUFFER_SIZE, "SCSI"); | |
637 | if (!atari_dma_buffer) { | |
c28bda25 RZ |
638 | printk(KERN_ERR "atari_scsi_detect: can't allocate ST-RAM " |
639 | "double buffer\n"); | |
640 | return 0; | |
1da177e4 | 641 | } |
c28bda25 | 642 | atari_dma_phys_buffer = virt_to_phys(atari_dma_buffer); |
1da177e4 LT |
643 | atari_dma_orig_addr = 0; |
644 | } | |
645 | #endif | |
c28bda25 RZ |
646 | instance = scsi_register(host, sizeof(struct NCR5380_hostdata)); |
647 | if (instance == NULL) { | |
1da177e4 LT |
648 | atari_stram_free(atari_dma_buffer); |
649 | atari_dma_buffer = 0; | |
650 | return 0; | |
651 | } | |
652 | atari_scsi_host = instance; | |
c28bda25 RZ |
653 | /* |
654 | * Set irq to 0, to avoid that the mid-level code disables our interrupt | |
655 | * during queue_command calls. This is completely unnecessary, and even | |
656 | * worse causes bad problems on the Falcon, where the int is shared with | |
657 | * IDE and floppy! | |
658 | */ | |
1da177e4 LT |
659 | instance->irq = 0; |
660 | ||
661 | #ifdef CONFIG_ATARI_SCSI_RESET_BOOT | |
662 | atari_scsi_reset_boot(); | |
663 | #endif | |
c28bda25 | 664 | NCR5380_init(instance, 0); |
1da177e4 LT |
665 | |
666 | if (IS_A_TT()) { | |
667 | ||
668 | /* This int is actually "pseudo-slow", i.e. it acts like a slow | |
669 | * interrupt after having cleared the pending flag for the DMA | |
670 | * interrupt. */ | |
671 | if (request_irq(IRQ_TT_MFP_SCSI, scsi_tt_intr, IRQ_TYPE_SLOW, | |
1e641664 | 672 | "SCSI NCR5380", instance)) { |
1da177e4 LT |
673 | printk(KERN_ERR "atari_scsi_detect: cannot allocate irq %d, aborting",IRQ_TT_MFP_SCSI); |
674 | scsi_unregister(atari_scsi_host); | |
675 | atari_stram_free(atari_dma_buffer); | |
676 | atari_dma_buffer = 0; | |
677 | return 0; | |
678 | } | |
679 | tt_mfp.active_edge |= 0x80; /* SCSI int on L->H */ | |
680 | #ifdef REAL_DMA | |
681 | tt_scsi_dma.dma_ctrl = 0; | |
682 | atari_dma_residual = 0; | |
29c8a246 AB |
683 | |
684 | if (MACH_IS_MEDUSA) { | |
1da177e4 LT |
685 | /* While the read overruns (described by Drew Eckhardt in |
686 | * NCR5380.c) never happened on TTs, they do in fact on the Medusa | |
687 | * (This was the cause why SCSI didn't work right for so long | |
688 | * there.) Since handling the overruns slows down a bit, I turned | |
689 | * the #ifdef's into a runtime condition. | |
690 | * | |
691 | * In principle it should be sufficient to do max. 1 byte with | |
692 | * PIO, but there is another problem on the Medusa with the DMA | |
693 | * rest data register. So 'atari_read_overruns' is currently set | |
694 | * to 4 to avoid having transfers that aren't a multiple of 4. If | |
695 | * the rest data bug is fixed, this can be lowered to 1. | |
696 | */ | |
697 | atari_read_overruns = 4; | |
c28bda25 | 698 | } |
1da177e4 | 699 | #endif /*REAL_DMA*/ |
c28bda25 RZ |
700 | } else { /* ! IS_A_TT */ |
701 | ||
1da177e4 LT |
702 | /* Nothing to do for the interrupt: the ST-DMA is initialized |
703 | * already by atari_init_INTS() | |
704 | */ | |
705 | ||
706 | #ifdef REAL_DMA | |
707 | atari_dma_residual = 0; | |
708 | atari_dma_active = 0; | |
709 | atari_dma_stram_mask = (ATARIHW_PRESENT(EXTD_DMA) ? 0x00000000 | |
710 | : 0xff000000); | |
711 | #endif | |
712 | } | |
713 | ||
714 | printk(KERN_INFO "scsi%d: options CAN_QUEUE=%d CMD_PER_LUN=%d SCAT-GAT=%d " | |
715 | #ifdef SUPPORT_TAGS | |
716 | "TAGGED-QUEUING=%s " | |
717 | #endif | |
718 | "HOSTID=%d", | |
719 | instance->host_no, instance->hostt->can_queue, | |
720 | instance->hostt->cmd_per_lun, | |
721 | instance->hostt->sg_tablesize, | |
722 | #ifdef SUPPORT_TAGS | |
723 | setup_use_tagged_queuing ? "yes" : "no", | |
724 | #endif | |
725 | instance->hostt->this_id ); | |
c28bda25 RZ |
726 | NCR5380_print_options(instance); |
727 | printk("\n"); | |
1da177e4 LT |
728 | |
729 | called = 1; | |
c28bda25 | 730 | return 1; |
1da177e4 LT |
731 | } |
732 | ||
107b5d53 | 733 | static int atari_scsi_release(struct Scsi_Host *sh) |
1da177e4 LT |
734 | { |
735 | if (IS_A_TT()) | |
1e641664 | 736 | free_irq(IRQ_TT_MFP_SCSI, sh); |
1da177e4 | 737 | if (atari_dma_buffer) |
c28bda25 | 738 | atari_stram_free(atari_dma_buffer); |
6323e4fe | 739 | NCR5380_exit(sh); |
1da177e4 LT |
740 | return 1; |
741 | } | |
1da177e4 | 742 | |
7b54e43a GU |
743 | #ifndef MODULE |
744 | static int __init atari_scsi_setup(char *str) | |
1da177e4 LT |
745 | { |
746 | /* Format of atascsi parameter is: | |
747 | * atascsi=<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags> | |
748 | * Defaults depend on TT or Falcon, hostid determined at run time. | |
749 | * Negative values mean don't change. | |
750 | */ | |
7b54e43a GU |
751 | int ints[6]; |
752 | ||
753 | get_options(str, ARRAY_SIZE(ints), ints); | |
c28bda25 | 754 | |
1da177e4 | 755 | if (ints[0] < 1) { |
c28bda25 | 756 | printk("atari_scsi_setup: no arguments!\n"); |
7b54e43a | 757 | return 0; |
1da177e4 LT |
758 | } |
759 | ||
760 | if (ints[0] >= 1) { | |
761 | if (ints[1] > 0) | |
762 | /* no limits on this, just > 0 */ | |
763 | setup_can_queue = ints[1]; | |
764 | } | |
765 | if (ints[0] >= 2) { | |
766 | if (ints[2] > 0) | |
767 | setup_cmd_per_lun = ints[2]; | |
768 | } | |
769 | if (ints[0] >= 3) { | |
770 | if (ints[3] >= 0) { | |
771 | setup_sg_tablesize = ints[3]; | |
772 | /* Must be <= SG_ALL (255) */ | |
773 | if (setup_sg_tablesize > SG_ALL) | |
774 | setup_sg_tablesize = SG_ALL; | |
775 | } | |
776 | } | |
777 | if (ints[0] >= 4) { | |
778 | /* Must be between 0 and 7 */ | |
779 | if (ints[4] >= 0 && ints[4] <= 7) | |
780 | setup_hostid = ints[4]; | |
781 | else if (ints[4] > 7) | |
c28bda25 | 782 | printk("atari_scsi_setup: invalid host ID %d !\n", ints[4]); |
1da177e4 LT |
783 | } |
784 | #ifdef SUPPORT_TAGS | |
785 | if (ints[0] >= 5) { | |
786 | if (ints[5] >= 0) | |
787 | setup_use_tagged_queuing = !!ints[5]; | |
788 | } | |
789 | #endif | |
7b54e43a GU |
790 | |
791 | return 1; | |
1da177e4 LT |
792 | } |
793 | ||
7b54e43a GU |
794 | __setup("atascsi=", atari_scsi_setup); |
795 | #endif /* !MODULE */ | |
796 | ||
107b5d53 | 797 | static int atari_scsi_bus_reset(Scsi_Cmnd *cmd) |
1da177e4 | 798 | { |
c28bda25 | 799 | int rv; |
1da177e4 LT |
800 | struct NCR5380_hostdata *hostdata = |
801 | (struct NCR5380_hostdata *)cmd->device->host->hostdata; | |
802 | ||
803 | /* For doing the reset, SCSI interrupts must be disabled first, | |
804 | * since the 5380 raises its IRQ line while _RST is active and we | |
805 | * can't disable interrupts completely, since we need the timer. | |
806 | */ | |
807 | /* And abort a maybe active DMA transfer */ | |
808 | if (IS_A_TT()) { | |
c28bda25 | 809 | atari_turnoff_irq(IRQ_TT_MFP_SCSI); |
1da177e4 LT |
810 | #ifdef REAL_DMA |
811 | tt_scsi_dma.dma_ctrl = 0; | |
812 | #endif /* REAL_DMA */ | |
c28bda25 RZ |
813 | } else { |
814 | atari_turnoff_irq(IRQ_MFP_FSCSI); | |
1da177e4 LT |
815 | #ifdef REAL_DMA |
816 | st_dma.dma_mode_status = 0x90; | |
817 | atari_dma_active = 0; | |
818 | atari_dma_orig_addr = NULL; | |
819 | #endif /* REAL_DMA */ | |
820 | } | |
821 | ||
822 | rv = NCR5380_bus_reset(cmd); | |
823 | ||
824 | /* Re-enable ints */ | |
825 | if (IS_A_TT()) { | |
c28bda25 RZ |
826 | atari_turnon_irq(IRQ_TT_MFP_SCSI); |
827 | } else { | |
828 | atari_turnon_irq(IRQ_MFP_FSCSI); | |
1da177e4 LT |
829 | } |
830 | if ((rv & SCSI_RESET_ACTION) == SCSI_RESET_SUCCESS) | |
831 | falcon_release_lock_if_possible(hostdata); | |
832 | ||
c28bda25 | 833 | return rv; |
1da177e4 LT |
834 | } |
835 | ||
c28bda25 | 836 | |
1da177e4 LT |
837 | #ifdef CONFIG_ATARI_SCSI_RESET_BOOT |
838 | static void __init atari_scsi_reset_boot(void) | |
839 | { | |
840 | unsigned long end; | |
c28bda25 | 841 | |
1da177e4 LT |
842 | /* |
843 | * Do a SCSI reset to clean up the bus during initialization. No messing | |
844 | * with the queues, interrupts, or locks necessary here. | |
845 | */ | |
846 | ||
c28bda25 | 847 | printk("Atari SCSI: resetting the SCSI bus..."); |
1da177e4 LT |
848 | |
849 | /* get in phase */ | |
c28bda25 RZ |
850 | NCR5380_write(TARGET_COMMAND_REG, |
851 | PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG))); | |
1da177e4 LT |
852 | |
853 | /* assert RST */ | |
c28bda25 | 854 | NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST); |
1da177e4 | 855 | /* The min. reset hold time is 25us, so 40us should be enough */ |
c28bda25 | 856 | udelay(50); |
1da177e4 | 857 | /* reset RST and interrupt */ |
c28bda25 RZ |
858 | NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); |
859 | NCR5380_read(RESET_PARITY_INTERRUPT_REG); | |
1da177e4 LT |
860 | |
861 | end = jiffies + AFTER_RESET_DELAY; | |
862 | while (time_before(jiffies, end)) | |
863 | barrier(); | |
864 | ||
c28bda25 | 865 | printk(" done\n"); |
1da177e4 LT |
866 | } |
867 | #endif | |
868 | ||
869 | ||
107b5d53 | 870 | static const char *atari_scsi_info(struct Scsi_Host *host) |
1da177e4 LT |
871 | { |
872 | /* atari_scsi_detect() is verbose enough... */ | |
873 | static const char string[] = "Atari native SCSI"; | |
874 | return string; | |
875 | } | |
876 | ||
877 | ||
878 | #if defined(REAL_DMA) | |
879 | ||
107b5d53 GU |
880 | static unsigned long atari_scsi_dma_setup(struct Scsi_Host *instance, |
881 | void *data, unsigned long count, | |
882 | int dir) | |
1da177e4 | 883 | { |
c28bda25 | 884 | unsigned long addr = virt_to_phys(data); |
1da177e4 LT |
885 | |
886 | DMA_PRINTK("scsi%d: setting up dma, data = %p, phys = %lx, count = %ld, " | |
887 | "dir = %d\n", instance->host_no, data, addr, count, dir); | |
888 | ||
889 | if (!IS_A_TT() && !STRAM_ADDR(addr)) { | |
890 | /* If we have a non-DMAable address on a Falcon, use the dribble | |
891 | * buffer; 'orig_addr' != 0 in the read case tells the interrupt | |
892 | * handler to copy data from the dribble buffer to the originally | |
893 | * wanted address. | |
894 | */ | |
895 | if (dir) | |
c28bda25 | 896 | memcpy(atari_dma_buffer, data, count); |
1da177e4 LT |
897 | else |
898 | atari_dma_orig_addr = data; | |
899 | addr = atari_dma_phys_buffer; | |
900 | } | |
c28bda25 | 901 | |
1da177e4 | 902 | atari_dma_startaddr = addr; /* Needed for calculating residual later. */ |
c28bda25 | 903 | |
1da177e4 LT |
904 | /* Cache cleanup stuff: On writes, push any dirty cache out before sending |
905 | * it to the peripheral. (Must be done before DMA setup, since at least | |
906 | * the ST-DMA begins to fill internal buffers right after setup. For | |
907 | * reads, invalidate any cache, may be altered after DMA without CPU | |
908 | * knowledge. | |
c28bda25 | 909 | * |
1da177e4 LT |
910 | * ++roman: For the Medusa, there's no need at all for that cache stuff, |
911 | * because the hardware does bus snooping (fine!). | |
912 | */ | |
c28bda25 | 913 | dma_cache_maintenance(addr, count, dir); |
1da177e4 LT |
914 | |
915 | if (count == 0) | |
916 | printk(KERN_NOTICE "SCSI warning: DMA programmed for 0 bytes !\n"); | |
917 | ||
918 | if (IS_A_TT()) { | |
919 | tt_scsi_dma.dma_ctrl = dir; | |
c28bda25 RZ |
920 | SCSI_DMA_WRITE_P(dma_addr, addr); |
921 | SCSI_DMA_WRITE_P(dma_cnt, count); | |
1da177e4 | 922 | tt_scsi_dma.dma_ctrl = dir | 2; |
c28bda25 RZ |
923 | } else { /* ! IS_A_TT */ |
924 | ||
1da177e4 | 925 | /* set address */ |
c28bda25 | 926 | SCSI_DMA_SETADR(addr); |
1da177e4 LT |
927 | |
928 | /* toggle direction bit to clear FIFO and set DMA direction */ | |
929 | dir <<= 8; | |
930 | st_dma.dma_mode_status = 0x90 | dir; | |
931 | st_dma.dma_mode_status = 0x90 | (dir ^ 0x100); | |
932 | st_dma.dma_mode_status = 0x90 | dir; | |
933 | udelay(40); | |
934 | /* On writes, round up the transfer length to the next multiple of 512 | |
935 | * (see also comment at atari_dma_xfer_len()). */ | |
936 | st_dma.fdc_acces_seccount = (count + (dir ? 511 : 0)) >> 9; | |
937 | udelay(40); | |
938 | st_dma.dma_mode_status = 0x10 | dir; | |
939 | udelay(40); | |
940 | /* need not restore value of dir, only boolean value is tested */ | |
941 | atari_dma_active = 1; | |
942 | } | |
943 | ||
c28bda25 | 944 | return count; |
1da177e4 LT |
945 | } |
946 | ||
947 | ||
c28bda25 | 948 | static long atari_scsi_dma_residual(struct Scsi_Host *instance) |
1da177e4 | 949 | { |
c28bda25 | 950 | return atari_dma_residual; |
1da177e4 LT |
951 | } |
952 | ||
953 | ||
954 | #define CMD_SURELY_BLOCK_MODE 0 | |
955 | #define CMD_SURELY_BYTE_MODE 1 | |
956 | #define CMD_MODE_UNKNOWN 2 | |
957 | ||
c28bda25 | 958 | static int falcon_classify_cmd(Scsi_Cmnd *cmd) |
1da177e4 LT |
959 | { |
960 | unsigned char opcode = cmd->cmnd[0]; | |
c28bda25 | 961 | |
1da177e4 | 962 | if (opcode == READ_DEFECT_DATA || opcode == READ_LONG || |
c28bda25 RZ |
963 | opcode == READ_BUFFER) |
964 | return CMD_SURELY_BYTE_MODE; | |
1da177e4 LT |
965 | else if (opcode == READ_6 || opcode == READ_10 || |
966 | opcode == 0xa8 /* READ_12 */ || opcode == READ_REVERSE || | |
967 | opcode == RECOVER_BUFFERED_DATA) { | |
968 | /* In case of a sequential-access target (tape), special care is | |
969 | * needed here: The transfer is block-mode only if the 'fixed' bit is | |
970 | * set! */ | |
971 | if (cmd->device->type == TYPE_TAPE && !(cmd->cmnd[1] & 1)) | |
c28bda25 | 972 | return CMD_SURELY_BYTE_MODE; |
1da177e4 | 973 | else |
c28bda25 RZ |
974 | return CMD_SURELY_BLOCK_MODE; |
975 | } else | |
976 | return CMD_MODE_UNKNOWN; | |
1da177e4 LT |
977 | } |
978 | ||
979 | ||
980 | /* This function calculates the number of bytes that can be transferred via | |
981 | * DMA. On the TT, this is arbitrary, but on the Falcon we have to use the | |
982 | * ST-DMA chip. There are only multiples of 512 bytes possible and max. | |
983 | * 255*512 bytes :-( This means also, that defining READ_OVERRUNS is not | |
984 | * possible on the Falcon, since that would require to program the DMA for | |
985 | * n*512 - atari_read_overrun bytes. But it seems that the Falcon doesn't have | |
986 | * the overrun problem, so this question is academic :-) | |
987 | */ | |
988 | ||
c28bda25 RZ |
989 | static unsigned long atari_dma_xfer_len(unsigned long wanted_len, |
990 | Scsi_Cmnd *cmd, int write_flag) | |
1da177e4 LT |
991 | { |
992 | unsigned long possible_len, limit; | |
29c8a246 | 993 | |
1da177e4 LT |
994 | if (IS_A_TT()) |
995 | /* TT SCSI DMA can transfer arbitrary #bytes */ | |
c28bda25 | 996 | return wanted_len; |
1da177e4 LT |
997 | |
998 | /* ST DMA chip is stupid -- only multiples of 512 bytes! (and max. | |
999 | * 255*512 bytes, but this should be enough) | |
1000 | * | |
1001 | * ++roman: Aaargl! Another Falcon-SCSI problem... There are some commands | |
1002 | * that return a number of bytes which cannot be known beforehand. In this | |
1003 | * case, the given transfer length is an "allocation length". Now it | |
1004 | * can happen that this allocation length is a multiple of 512 bytes and | |
1005 | * the DMA is used. But if not n*512 bytes really arrive, some input data | |
1006 | * will be lost in the ST-DMA's FIFO :-( Thus, we have to distinguish | |
1007 | * between commands that do block transfers and those that do byte | |
1008 | * transfers. But this isn't easy... there are lots of vendor specific | |
1009 | * commands, and the user can issue any command via the | |
1010 | * SCSI_IOCTL_SEND_COMMAND. | |
1011 | * | |
1012 | * The solution: We classify SCSI commands in 1) surely block-mode cmd.s, | |
1013 | * 2) surely byte-mode cmd.s and 3) cmd.s with unknown mode. In case 1) | |
1014 | * and 3), the thing to do is obvious: allow any number of blocks via DMA | |
1015 | * or none. In case 2), we apply some heuristic: Byte mode is assumed if | |
1016 | * the transfer (allocation) length is < 1024, hoping that no cmd. not | |
1017 | * explicitly known as byte mode have such big allocation lengths... | |
1018 | * BTW, all the discussion above applies only to reads. DMA writes are | |
1019 | * unproblematic anyways, since the targets aborts the transfer after | |
1020 | * receiving a sufficient number of bytes. | |
1021 | * | |
1022 | * Another point: If the transfer is from/to an non-ST-RAM address, we | |
1023 | * use the dribble buffer and thus can do only STRAM_BUFFER_SIZE bytes. | |
1024 | */ | |
1025 | ||
1026 | if (write_flag) { | |
1027 | /* Write operation can always use the DMA, but the transfer size must | |
1028 | * be rounded up to the next multiple of 512 (atari_dma_setup() does | |
1029 | * this). | |
1030 | */ | |
1031 | possible_len = wanted_len; | |
c28bda25 | 1032 | } else { |
1da177e4 LT |
1033 | /* Read operations: if the wanted transfer length is not a multiple of |
1034 | * 512, we cannot use DMA, since the ST-DMA cannot split transfers | |
1035 | * (no interrupt on DMA finished!) | |
1036 | */ | |
1037 | if (wanted_len & 0x1ff) | |
1038 | possible_len = 0; | |
1039 | else { | |
1040 | /* Now classify the command (see above) and decide whether it is | |
1041 | * allowed to do DMA at all */ | |
c28bda25 RZ |
1042 | switch (falcon_classify_cmd(cmd)) { |
1043 | case CMD_SURELY_BLOCK_MODE: | |
1da177e4 LT |
1044 | possible_len = wanted_len; |
1045 | break; | |
c28bda25 | 1046 | case CMD_SURELY_BYTE_MODE: |
1da177e4 LT |
1047 | possible_len = 0; /* DMA prohibited */ |
1048 | break; | |
c28bda25 RZ |
1049 | case CMD_MODE_UNKNOWN: |
1050 | default: | |
1da177e4 LT |
1051 | /* For unknown commands assume block transfers if the transfer |
1052 | * size/allocation length is >= 1024 */ | |
1053 | possible_len = (wanted_len < 1024) ? 0 : wanted_len; | |
1054 | break; | |
1055 | } | |
1056 | } | |
1057 | } | |
c28bda25 | 1058 | |
1da177e4 | 1059 | /* Last step: apply the hard limit on DMA transfers */ |
c28bda25 | 1060 | limit = (atari_dma_buffer && !STRAM_ADDR(virt_to_phys(cmd->SCp.ptr))) ? |
1da177e4 LT |
1061 | STRAM_BUFFER_SIZE : 255*512; |
1062 | if (possible_len > limit) | |
1063 | possible_len = limit; | |
1064 | ||
1065 | if (possible_len != wanted_len) | |
1066 | DMA_PRINTK("Sorry, must cut DMA transfer size to %ld bytes " | |
1067 | "instead of %ld\n", possible_len, wanted_len); | |
1068 | ||
c28bda25 | 1069 | return possible_len; |
1da177e4 LT |
1070 | } |
1071 | ||
1072 | ||
1073 | #endif /* REAL_DMA */ | |
1074 | ||
1075 | ||
1076 | /* NCR5380 register access functions | |
1077 | * | |
1078 | * There are separate functions for TT and Falcon, because the access | |
1079 | * methods are quite different. The calling macros NCR5380_read and | |
1080 | * NCR5380_write call these functions via function pointers. | |
1081 | */ | |
1082 | ||
c28bda25 | 1083 | static unsigned char atari_scsi_tt_reg_read(unsigned char reg) |
1da177e4 | 1084 | { |
c28bda25 | 1085 | return tt_scsi_regp[reg * 2]; |
1da177e4 LT |
1086 | } |
1087 | ||
c28bda25 | 1088 | static void atari_scsi_tt_reg_write(unsigned char reg, unsigned char value) |
1da177e4 LT |
1089 | { |
1090 | tt_scsi_regp[reg * 2] = value; | |
1091 | } | |
1092 | ||
c28bda25 | 1093 | static unsigned char atari_scsi_falcon_reg_read(unsigned char reg) |
1da177e4 LT |
1094 | { |
1095 | dma_wd.dma_mode_status= (u_short)(0x88 + reg); | |
c28bda25 | 1096 | return (u_char)dma_wd.fdc_acces_seccount; |
1da177e4 LT |
1097 | } |
1098 | ||
c28bda25 | 1099 | static void atari_scsi_falcon_reg_write(unsigned char reg, unsigned char value) |
1da177e4 LT |
1100 | { |
1101 | dma_wd.dma_mode_status = (u_short)(0x88 + reg); | |
1102 | dma_wd.fdc_acces_seccount = (u_short)value; | |
1103 | } | |
1104 | ||
1105 | ||
1106 | #include "atari_NCR5380.c" | |
1107 | ||
d0be4a7d | 1108 | static struct scsi_host_template driver_template = { |
d89537e1 | 1109 | .show_info = atari_scsi_show_info, |
1da177e4 LT |
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 | ||
1127 | MODULE_LICENSE("GPL"); |