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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Generic Macintosh NCR5380 driver
4 *
5 * Copyright 1998, Michael Schmitz <[email protected]>
6 *
7 * Copyright 2019 Finn Thain
8 *
9 * derived in part from:
10 */
11/*
12 * Generic Generic NCR5380 driver
13 *
14 * Copyright 1995, Russell King
15 */
16
17#include <linux/delay.h>
18#include <linux/types.h>
19#include <linux/module.h>
20#include <linux/ioport.h>
21#include <linux/init.h>
22#include <linux/blkdev.h>
23#include <linux/interrupt.h>
24#include <linux/platform_device.h>
25
26#include <asm/hwtest.h>
27#include <asm/io.h>
28#include <asm/macintosh.h>
29#include <asm/macints.h>
30#include <asm/setup.h>
31
32#include <scsi/scsi_host.h>
33
34/* Definitions for the core NCR5380 driver. */
35
36#define NCR5380_implementation_fields int pdma_residual
37
38#define NCR5380_read(reg) in_8(hostdata->io + ((reg) << 4))
39#define NCR5380_write(reg, value) out_8(hostdata->io + ((reg) << 4), value)
40
41#define NCR5380_dma_xfer_len macscsi_dma_xfer_len
42#define NCR5380_dma_recv_setup macscsi_pread
43#define NCR5380_dma_send_setup macscsi_pwrite
44#define NCR5380_dma_residual macscsi_dma_residual
45
46#define NCR5380_intr macscsi_intr
47#define NCR5380_queue_command macscsi_queue_command
48#define NCR5380_abort macscsi_abort
49#define NCR5380_host_reset macscsi_host_reset
50#define NCR5380_info macscsi_info
51
52#include "NCR5380.h"
53
54static int setup_can_queue = -1;
55module_param(setup_can_queue, int, 0);
56static int setup_cmd_per_lun = -1;
57module_param(setup_cmd_per_lun, int, 0);
58static int setup_sg_tablesize = -1;
59module_param(setup_sg_tablesize, int, 0);
60static int setup_use_pdma = 512;
61module_param(setup_use_pdma, int, 0);
62static int setup_hostid = -1;
63module_param(setup_hostid, int, 0);
64static int setup_toshiba_delay = -1;
65module_param(setup_toshiba_delay, int, 0);
66
67#ifndef MODULE
68static int __init mac_scsi_setup(char *str)
69{
70 int ints[8];
71
72 (void)get_options(str, ARRAY_SIZE(ints), ints);
73
74 if (ints[0] < 1) {
75 pr_err("Usage: mac5380=<can_queue>[,<cmd_per_lun>[,<sg_tablesize>[,<hostid>[,<use_tags>[,<use_pdma>[,<toshiba_delay>]]]]]]\n");
76 return 0;
77 }
78 if (ints[0] >= 1)
79 setup_can_queue = ints[1];
80 if (ints[0] >= 2)
81 setup_cmd_per_lun = ints[2];
82 if (ints[0] >= 3)
83 setup_sg_tablesize = ints[3];
84 if (ints[0] >= 4)
85 setup_hostid = ints[4];
86 /* ints[5] (use_tagged_queuing) is ignored */
87 if (ints[0] >= 6)
88 setup_use_pdma = ints[6];
89 if (ints[0] >= 7)
90 setup_toshiba_delay = ints[7];
91 return 1;
92}
93
94__setup("mac5380=", mac_scsi_setup);
95#endif /* !MODULE */
96
97/*
98 * According to "Inside Macintosh: Devices", Mac OS requires disk drivers to
99 * specify the number of bytes between the delays expected from a SCSI target.
100 * This allows the operating system to "prevent bus errors when a target fails
101 * to deliver the next byte within the processor bus error timeout period."
102 * Linux SCSI drivers lack knowledge of the timing behaviour of SCSI targets
103 * so bus errors are unavoidable.
104 *
105 * If a MOVE.B instruction faults during a receive operation, we assume the
106 * target sent nothing and try again. That assumption probably depends on
107 * target firmware but it seems to hold up okay. If a fault happens during a
108 * send operation, the target may or may not have seen /ACK and got the byte.
109 * It's uncertain so the whole SCSI command gets retried.
110 *
111 * The NOP is needed for synchronization because the fault address in the
112 * exception stack frame may or may not be the instruction that actually
113 * caused the bus error. Post-increment addressing can't be used.
114 */
115
116#define MOVE_BYTE(operands) \
117 asm volatile ( \
118 "1: moveb " operands " \n" \
119 "11: nop \n" \
120 " addq #1,%0 \n" \
121 " subq #1,%1 \n" \
122 "40: \n" \
123 " \n" \
124 ".section .fixup,\"ax\" \n" \
125 ".even \n" \
126 "90: movel #1, %2 \n" \
127 " jra 40b \n" \
128 ".previous \n" \
129 " \n" \
130 ".section __ex_table,\"a\" \n" \
131 ".align 4 \n" \
132 ".long 1b,90b \n" \
133 ".long 11b,90b \n" \
134 ".previous \n" \
135 : "+a" (addr), "+r" (n), "+r" (result) : "a" (io))
136
137/*
138 * If a MOVE.W (or MOVE.L) instruction faults, it cannot be retried because
139 * the residual byte count would be uncertain. In that situation the MOVE_WORD
140 * macro clears n in the fixup section to abort the transfer.
141 */
142
143#define MOVE_WORD(operands) \
144 asm volatile ( \
145 "1: movew " operands " \n" \
146 "11: nop \n" \
147 " subq #2,%1 \n" \
148 "40: \n" \
149 " \n" \
150 ".section .fixup,\"ax\" \n" \
151 ".even \n" \
152 "90: movel #0, %1 \n" \
153 " movel #2, %2 \n" \
154 " jra 40b \n" \
155 ".previous \n" \
156 " \n" \
157 ".section __ex_table,\"a\" \n" \
158 ".align 4 \n" \
159 ".long 1b,90b \n" \
160 ".long 11b,90b \n" \
161 ".previous \n" \
162 : "+a" (addr), "+r" (n), "+r" (result) : "a" (io))
163
164#define MOVE_16_WORDS(operands) \
165 asm volatile ( \
166 "1: movew " operands " \n" \
167 "2: movew " operands " \n" \
168 "3: movew " operands " \n" \
169 "4: movew " operands " \n" \
170 "5: movew " operands " \n" \
171 "6: movew " operands " \n" \
172 "7: movew " operands " \n" \
173 "8: movew " operands " \n" \
174 "9: movew " operands " \n" \
175 "10: movew " operands " \n" \
176 "11: movew " operands " \n" \
177 "12: movew " operands " \n" \
178 "13: movew " operands " \n" \
179 "14: movew " operands " \n" \
180 "15: movew " operands " \n" \
181 "16: movew " operands " \n" \
182 "17: nop \n" \
183 " subl #32,%1 \n" \
184 "40: \n" \
185 " \n" \
186 ".section .fixup,\"ax\" \n" \
187 ".even \n" \
188 "90: movel #0, %1 \n" \
189 " movel #2, %2 \n" \
190 " jra 40b \n" \
191 ".previous \n" \
192 " \n" \
193 ".section __ex_table,\"a\" \n" \
194 ".align 4 \n" \
195 ".long 1b,90b \n" \
196 ".long 2b,90b \n" \
197 ".long 3b,90b \n" \
198 ".long 4b,90b \n" \
199 ".long 5b,90b \n" \
200 ".long 6b,90b \n" \
201 ".long 7b,90b \n" \
202 ".long 8b,90b \n" \
203 ".long 9b,90b \n" \
204 ".long 10b,90b \n" \
205 ".long 11b,90b \n" \
206 ".long 12b,90b \n" \
207 ".long 13b,90b \n" \
208 ".long 14b,90b \n" \
209 ".long 15b,90b \n" \
210 ".long 16b,90b \n" \
211 ".long 17b,90b \n" \
212 ".previous \n" \
213 : "+a" (addr), "+r" (n), "+r" (result) : "a" (io))
214
215static inline int mac_pdma_recv(void __iomem *io, unsigned char *start, int n)
216{
217 unsigned char *addr = start;
218 int result = 0;
219
220 if (n >= 1) {
221 MOVE_BYTE("%3@,%0@");
222 if (result)
223 goto out;
224 }
225 if (n >= 1 && ((unsigned long)addr & 1)) {
226 MOVE_BYTE("%3@,%0@");
227 if (result)
228 goto out;
229 }
230 while (n >= 32)
231 MOVE_16_WORDS("%3@,%0@+");
232 while (n >= 2)
233 MOVE_WORD("%3@,%0@+");
234 if (result)
235 return start - addr; /* Negated to indicate uncertain length */
236 if (n == 1)
237 MOVE_BYTE("%3@,%0@");
238out:
239 return addr - start;
240}
241
242static inline int mac_pdma_send(unsigned char *start, void __iomem *io, int n)
243{
244 unsigned char *addr = start;
245 int result = 0;
246
247 if (n >= 1) {
248 MOVE_BYTE("%0@,%3@");
249 if (result)
250 return -1;
251 }
252 if (n >= 1 && ((unsigned long)addr & 1)) {
253 MOVE_BYTE("%0@,%3@");
254 if (result)
255 return -2;
256 }
257 while (n >= 32)
258 MOVE_16_WORDS("%0@+,%3@");
259 while (n >= 2)
260 MOVE_WORD("%0@+,%3@");
261 if (result)
262 return start - addr - 1; /* Negated to indicate uncertain length */
263 if (n == 1)
264 MOVE_BYTE("%0@,%3@");
265 return addr - start;
266}
267
268/* The "SCSI DMA" chip on the IIfx implements this register. */
269#define CTRL_REG 0x8
270#define CTRL_INTERRUPTS_ENABLE BIT(1)
271#define CTRL_HANDSHAKE_MODE BIT(3)
272
273static inline void write_ctrl_reg(struct NCR5380_hostdata *hostdata, u32 value)
274{
275 out_be32(hostdata->io + (CTRL_REG << 4), value);
276}
277
278static inline int macscsi_wait_for_drq(struct NCR5380_hostdata *hostdata)
279{
280 unsigned int n = 1; /* effectively multiplies NCR5380_REG_POLL_TIME */
281 unsigned char basr;
282
283again:
284 basr = NCR5380_read(BUS_AND_STATUS_REG);
285
286 if (!(basr & BASR_PHASE_MATCH))
287 return 1;
288
289 if (basr & BASR_IRQ)
290 return -1;
291
292 if (basr & BASR_DRQ)
293 return 0;
294
295 if (n-- == 0) {
296 NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host);
297 dsprintk(NDEBUG_PSEUDO_DMA, hostdata->host,
298 "%s: DRQ timeout\n", __func__);
299 return -1;
300 }
301
302 NCR5380_poll_politely2(hostdata,
303 BUS_AND_STATUS_REG, BASR_DRQ, BASR_DRQ,
304 BUS_AND_STATUS_REG, BASR_PHASE_MATCH, 0, 0);
305 goto again;
306}
307
308static inline int macscsi_pread(struct NCR5380_hostdata *hostdata,
309 unsigned char *dst, int len)
310{
311 u8 __iomem *s = hostdata->pdma_io + (INPUT_DATA_REG << 4);
312 unsigned char *d = dst;
313
314 hostdata->pdma_residual = len;
315
316 while (macscsi_wait_for_drq(hostdata) == 0) {
317 int bytes, chunk_bytes;
318
319 if (macintosh_config->ident == MAC_MODEL_IIFX)
320 write_ctrl_reg(hostdata, CTRL_HANDSHAKE_MODE |
321 CTRL_INTERRUPTS_ENABLE);
322
323 chunk_bytes = min(hostdata->pdma_residual, 512);
324 bytes = mac_pdma_recv(s, d, chunk_bytes);
325
326 if (macintosh_config->ident == MAC_MODEL_IIFX)
327 write_ctrl_reg(hostdata, CTRL_INTERRUPTS_ENABLE);
328
329 if (bytes > 0) {
330 d += bytes;
331 hostdata->pdma_residual -= bytes;
332 }
333
334 if (hostdata->pdma_residual == 0)
335 break;
336
337 if (bytes > 0)
338 continue;
339
340 NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host);
341 dsprintk(NDEBUG_PSEUDO_DMA, hostdata->host,
342 "%s: bus error [%d/%d] (%d/%d)\n",
343 __func__, d - dst, len, bytes, chunk_bytes);
344
345 if (bytes == 0)
346 continue;
347
348 if (macscsi_wait_for_drq(hostdata) <= 0)
349 set_host_byte(hostdata->connected, DID_ERROR);
350 break;
351 }
352
353 return 0;
354}
355
356static inline int macscsi_pwrite(struct NCR5380_hostdata *hostdata,
357 unsigned char *src, int len)
358{
359 unsigned char *s = src;
360 u8 __iomem *d = hostdata->pdma_io + (OUTPUT_DATA_REG << 4);
361
362 hostdata->pdma_residual = len;
363
364 while (macscsi_wait_for_drq(hostdata) == 0) {
365 int bytes, chunk_bytes;
366
367 if (macintosh_config->ident == MAC_MODEL_IIFX)
368 write_ctrl_reg(hostdata, CTRL_HANDSHAKE_MODE |
369 CTRL_INTERRUPTS_ENABLE);
370
371 chunk_bytes = min(hostdata->pdma_residual, 512);
372 bytes = mac_pdma_send(s, d, chunk_bytes);
373
374 if (macintosh_config->ident == MAC_MODEL_IIFX)
375 write_ctrl_reg(hostdata, CTRL_INTERRUPTS_ENABLE);
376
377 if (bytes > 0) {
378 s += bytes;
379 hostdata->pdma_residual -= bytes;
380 }
381
382 if (hostdata->pdma_residual == 0)
383 break;
384
385 if (bytes > 0)
386 continue;
387
388 NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host);
389 dsprintk(NDEBUG_PSEUDO_DMA, hostdata->host,
390 "%s: bus error [%d/%d] (%d/%d)\n",
391 __func__, s - src, len, bytes, chunk_bytes);
392
393 if (bytes == 0)
394 continue;
395
396 if (macscsi_wait_for_drq(hostdata) <= 0)
397 set_host_byte(hostdata->connected, DID_ERROR);
398 break;
399 }
400
401 return 0;
402}
403
404static int macscsi_dma_xfer_len(struct NCR5380_hostdata *hostdata,
405 struct scsi_cmnd *cmd)
406{
407 int resid = NCR5380_to_ncmd(cmd)->this_residual;
408
409 if (hostdata->flags & FLAG_NO_PSEUDO_DMA || resid < setup_use_pdma)
410 return 0;
411
412 return resid;
413}
414
415static int macscsi_dma_residual(struct NCR5380_hostdata *hostdata)
416{
417 return hostdata->pdma_residual;
418}
419
420#include "NCR5380.c"
421
422#define DRV_MODULE_NAME "mac_scsi"
423#define PFX DRV_MODULE_NAME ": "
424
425static struct scsi_host_template mac_scsi_template = {
426 .module = THIS_MODULE,
427 .proc_name = DRV_MODULE_NAME,
428 .name = "Macintosh NCR5380 SCSI",
429 .info = macscsi_info,
430 .queuecommand = macscsi_queue_command,
431 .eh_abort_handler = macscsi_abort,
432 .eh_host_reset_handler = macscsi_host_reset,
433 .can_queue = 16,
434 .this_id = 7,
435 .sg_tablesize = SG_ALL,
436 .cmd_per_lun = 2,
437 .dma_boundary = PAGE_SIZE - 1,
438 .cmd_size = sizeof(struct NCR5380_cmd),
439 .max_sectors = 128,
440};
441
442static int __init mac_scsi_probe(struct platform_device *pdev)
443{
444 struct Scsi_Host *instance;
445 struct NCR5380_hostdata *hostdata;
446 int error;
447 int host_flags = 0;
448 struct resource *irq, *pio_mem, *pdma_mem = NULL;
449
450 pio_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
451 if (!pio_mem)
452 return -ENODEV;
453
454 pdma_mem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
455
456 irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
457
458 if (!hwreg_present((unsigned char *)pio_mem->start +
459 (STATUS_REG << 4))) {
460 pr_info(PFX "no device detected at %pap\n", &pio_mem->start);
461 return -ENODEV;
462 }
463
464 if (setup_can_queue > 0)
465 mac_scsi_template.can_queue = setup_can_queue;
466 if (setup_cmd_per_lun > 0)
467 mac_scsi_template.cmd_per_lun = setup_cmd_per_lun;
468 if (setup_sg_tablesize > 0)
469 mac_scsi_template.sg_tablesize = setup_sg_tablesize;
470 if (setup_hostid >= 0)
471 mac_scsi_template.this_id = setup_hostid & 7;
472
473 if (macintosh_config->ident == MAC_MODEL_IIFX)
474 mac_scsi_template.sg_tablesize = 1;
475
476 instance = scsi_host_alloc(&mac_scsi_template,
477 sizeof(struct NCR5380_hostdata));
478 if (!instance)
479 return -ENOMEM;
480
481 if (irq)
482 instance->irq = irq->start;
483 else
484 instance->irq = NO_IRQ;
485
486 hostdata = shost_priv(instance);
487 hostdata->base = pio_mem->start;
488 hostdata->io = (u8 __iomem *)pio_mem->start;
489
490 if (pdma_mem && setup_use_pdma)
491 hostdata->pdma_io = (u8 __iomem *)pdma_mem->start;
492 else
493 host_flags |= FLAG_NO_PSEUDO_DMA;
494
495 host_flags |= setup_toshiba_delay > 0 ? FLAG_TOSHIBA_DELAY : 0;
496
497 if (instance->sg_tablesize > 1)
498 host_flags |= FLAG_DMA_FIXUP;
499
500 error = NCR5380_init(instance, host_flags | FLAG_LATE_DMA_SETUP);
501 if (error)
502 goto fail_init;
503
504 if (instance->irq != NO_IRQ) {
505 error = request_irq(instance->irq, macscsi_intr, IRQF_SHARED,
506 "NCR5380", instance);
507 if (error)
508 goto fail_irq;
509 }
510
511 NCR5380_maybe_reset_bus(instance);
512
513 error = scsi_add_host(instance, NULL);
514 if (error)
515 goto fail_host;
516
517 platform_set_drvdata(pdev, instance);
518
519 scsi_scan_host(instance);
520 return 0;
521
522fail_host:
523 if (instance->irq != NO_IRQ)
524 free_irq(instance->irq, instance);
525fail_irq:
526 NCR5380_exit(instance);
527fail_init:
528 scsi_host_put(instance);
529 return error;
530}
531
532static void __exit mac_scsi_remove(struct platform_device *pdev)
533{
534 struct Scsi_Host *instance = platform_get_drvdata(pdev);
535
536 scsi_remove_host(instance);
537 if (instance->irq != NO_IRQ)
538 free_irq(instance->irq, instance);
539 NCR5380_exit(instance);
540 scsi_host_put(instance);
541}
542
543/*
544 * mac_scsi_remove() lives in .exit.text. For drivers registered via
545 * module_platform_driver_probe() this is ok because they cannot get unbound at
546 * runtime. So mark the driver struct with __refdata to prevent modpost
547 * triggering a section mismatch warning.
548 */
549static struct platform_driver mac_scsi_driver __refdata = {
550 .remove = __exit_p(mac_scsi_remove),
551 .driver = {
552 .name = DRV_MODULE_NAME,
553 },
554};
555
556module_platform_driver_probe(mac_scsi_driver, mac_scsi_probe);
557
558MODULE_ALIAS("platform:" DRV_MODULE_NAME);
559MODULE_DESCRIPTION("Macintosh NCR5380 SCSI driver");
560MODULE_LICENSE("GPL");