xref: /openbmc/linux/drivers/scsi/mac_scsi.c (revision 1df8231f)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Generic Macintosh NCR5380 driver
4  *
5  * Copyright 1998, Michael Schmitz <mschmitz@lbl.gov>
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 
54 static int setup_can_queue = -1;
55 module_param(setup_can_queue, int, 0);
56 static int setup_cmd_per_lun = -1;
57 module_param(setup_cmd_per_lun, int, 0);
58 static int setup_sg_tablesize = -1;
59 module_param(setup_sg_tablesize, int, 0);
60 static int setup_use_pdma = 512;
61 module_param(setup_use_pdma, int, 0);
62 static int setup_hostid = -1;
63 module_param(setup_hostid, int, 0);
64 static int setup_toshiba_delay = -1;
65 module_param(setup_toshiba_delay, int, 0);
66 
67 #ifndef MODULE
68 static 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 
215 static 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@");
238 out:
239 	return addr - start;
240 }
241 
242 static 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 
273 static inline void write_ctrl_reg(struct NCR5380_hostdata *hostdata, u32 value)
274 {
275 	out_be32(hostdata->io + (CTRL_REG << 4), value);
276 }
277 
278 static 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 
283 again:
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 
308 static 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 
356 static 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 
404 static 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 
415 static 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 
425 static 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		= 1,
436 	.cmd_per_lun		= 2,
437 	.dma_boundary		= PAGE_SIZE - 1,
438 	.cmd_size		= sizeof(struct NCR5380_cmd),
439 	.max_sectors		= 128,
440 };
441 
442 static 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 	instance = scsi_host_alloc(&mac_scsi_template,
474 	                           sizeof(struct NCR5380_hostdata));
475 	if (!instance)
476 		return -ENOMEM;
477 
478 	if (irq)
479 		instance->irq = irq->start;
480 	else
481 		instance->irq = NO_IRQ;
482 
483 	hostdata = shost_priv(instance);
484 	hostdata->base = pio_mem->start;
485 	hostdata->io = (u8 __iomem *)pio_mem->start;
486 
487 	if (pdma_mem && setup_use_pdma)
488 		hostdata->pdma_io = (u8 __iomem *)pdma_mem->start;
489 	else
490 		host_flags |= FLAG_NO_PSEUDO_DMA;
491 
492 	host_flags |= setup_toshiba_delay > 0 ? FLAG_TOSHIBA_DELAY : 0;
493 
494 	error = NCR5380_init(instance, host_flags | FLAG_LATE_DMA_SETUP);
495 	if (error)
496 		goto fail_init;
497 
498 	if (instance->irq != NO_IRQ) {
499 		error = request_irq(instance->irq, macscsi_intr, IRQF_SHARED,
500 		                    "NCR5380", instance);
501 		if (error)
502 			goto fail_irq;
503 	}
504 
505 	NCR5380_maybe_reset_bus(instance);
506 
507 	error = scsi_add_host(instance, NULL);
508 	if (error)
509 		goto fail_host;
510 
511 	platform_set_drvdata(pdev, instance);
512 
513 	scsi_scan_host(instance);
514 	return 0;
515 
516 fail_host:
517 	if (instance->irq != NO_IRQ)
518 		free_irq(instance->irq, instance);
519 fail_irq:
520 	NCR5380_exit(instance);
521 fail_init:
522 	scsi_host_put(instance);
523 	return error;
524 }
525 
526 static int __exit mac_scsi_remove(struct platform_device *pdev)
527 {
528 	struct Scsi_Host *instance = platform_get_drvdata(pdev);
529 
530 	scsi_remove_host(instance);
531 	if (instance->irq != NO_IRQ)
532 		free_irq(instance->irq, instance);
533 	NCR5380_exit(instance);
534 	scsi_host_put(instance);
535 	return 0;
536 }
537 
538 static struct platform_driver mac_scsi_driver = {
539 	.remove = __exit_p(mac_scsi_remove),
540 	.driver = {
541 		.name	= DRV_MODULE_NAME,
542 	},
543 };
544 
545 module_platform_driver_probe(mac_scsi_driver, mac_scsi_probe);
546 
547 MODULE_ALIAS("platform:" DRV_MODULE_NAME);
548 MODULE_LICENSE("GPL");
549