xref: /openbmc/linux/drivers/scsi/mac_scsi.c (revision b737eecd)
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, we assume that zero bytes were transferred
106  * and simply retry. That assumption probably depends on target behaviour but
107  * seems to hold up okay. The NOP provides synchronization: without it the
108  * fault can sometimes occur after the program counter has moved past the
109  * offending instruction. Post-increment addressing can't be used.
110  */
111 
112 #define MOVE_BYTE(operands) \
113 	asm volatile ( \
114 		"1:     moveb " operands "     \n" \
115 		"11:    nop                    \n" \
116 		"       addq #1,%0             \n" \
117 		"       subq #1,%1             \n" \
118 		"40:                           \n" \
119 		"                              \n" \
120 		".section .fixup,\"ax\"        \n" \
121 		".even                         \n" \
122 		"90:    movel #1, %2           \n" \
123 		"       jra 40b                \n" \
124 		".previous                     \n" \
125 		"                              \n" \
126 		".section __ex_table,\"a\"     \n" \
127 		".align  4                     \n" \
128 		".long   1b,90b                \n" \
129 		".long  11b,90b                \n" \
130 		".previous                     \n" \
131 		: "+a" (addr), "+r" (n), "+r" (result) : "a" (io))
132 
133 /*
134  * If a MOVE.W (or MOVE.L) instruction faults, it cannot be retried because
135  * the residual byte count would be uncertain. In that situation the MOVE_WORD
136  * macro clears n in the fixup section to abort the transfer.
137  */
138 
139 #define MOVE_WORD(operands) \
140 	asm volatile ( \
141 		"1:     movew " operands "     \n" \
142 		"11:    nop                    \n" \
143 		"       subq #2,%1             \n" \
144 		"40:                           \n" \
145 		"                              \n" \
146 		".section .fixup,\"ax\"        \n" \
147 		".even                         \n" \
148 		"90:    movel #0, %1           \n" \
149 		"       movel #2, %2           \n" \
150 		"       jra 40b                \n" \
151 		".previous                     \n" \
152 		"                              \n" \
153 		".section __ex_table,\"a\"     \n" \
154 		".align  4                     \n" \
155 		".long   1b,90b                \n" \
156 		".long  11b,90b                \n" \
157 		".previous                     \n" \
158 		: "+a" (addr), "+r" (n), "+r" (result) : "a" (io))
159 
160 #define MOVE_16_WORDS(operands) \
161 	asm volatile ( \
162 		"1:     movew " operands "     \n" \
163 		"2:     movew " operands "     \n" \
164 		"3:     movew " operands "     \n" \
165 		"4:     movew " operands "     \n" \
166 		"5:     movew " operands "     \n" \
167 		"6:     movew " operands "     \n" \
168 		"7:     movew " operands "     \n" \
169 		"8:     movew " operands "     \n" \
170 		"9:     movew " operands "     \n" \
171 		"10:    movew " operands "     \n" \
172 		"11:    movew " operands "     \n" \
173 		"12:    movew " operands "     \n" \
174 		"13:    movew " operands "     \n" \
175 		"14:    movew " operands "     \n" \
176 		"15:    movew " operands "     \n" \
177 		"16:    movew " operands "     \n" \
178 		"17:    nop                    \n" \
179 		"       subl  #32,%1           \n" \
180 		"40:                           \n" \
181 		"                              \n" \
182 		".section .fixup,\"ax\"        \n" \
183 		".even                         \n" \
184 		"90:    movel #0, %1           \n" \
185 		"       movel #2, %2           \n" \
186 		"       jra 40b                \n" \
187 		".previous                     \n" \
188 		"                              \n" \
189 		".section __ex_table,\"a\"     \n" \
190 		".align  4                     \n" \
191 		".long   1b,90b                \n" \
192 		".long   2b,90b                \n" \
193 		".long   3b,90b                \n" \
194 		".long   4b,90b                \n" \
195 		".long   5b,90b                \n" \
196 		".long   6b,90b                \n" \
197 		".long   7b,90b                \n" \
198 		".long   8b,90b                \n" \
199 		".long   9b,90b                \n" \
200 		".long  10b,90b                \n" \
201 		".long  11b,90b                \n" \
202 		".long  12b,90b                \n" \
203 		".long  13b,90b                \n" \
204 		".long  14b,90b                \n" \
205 		".long  15b,90b                \n" \
206 		".long  16b,90b                \n" \
207 		".long  17b,90b                \n" \
208 		".previous                     \n" \
209 		: "+a" (addr), "+r" (n), "+r" (result) : "a" (io))
210 
211 #define MAC_PDMA_DELAY		32
212 
213 static inline int mac_pdma_recv(void __iomem *io, unsigned char *start, int n)
214 {
215 	unsigned char *addr = start;
216 	int result = 0;
217 
218 	if (n >= 1) {
219 		MOVE_BYTE("%3@,%0@");
220 		if (result)
221 			goto out;
222 	}
223 	if (n >= 1 && ((unsigned long)addr & 1)) {
224 		MOVE_BYTE("%3@,%0@");
225 		if (result)
226 			goto out;
227 	}
228 	while (n >= 32)
229 		MOVE_16_WORDS("%3@,%0@+");
230 	while (n >= 2)
231 		MOVE_WORD("%3@,%0@+");
232 	if (result)
233 		return start - addr; /* Negated to indicate uncertain length */
234 	if (n == 1)
235 		MOVE_BYTE("%3@,%0@");
236 out:
237 	return addr - start;
238 }
239 
240 static inline int mac_pdma_send(unsigned char *start, void __iomem *io, int n)
241 {
242 	unsigned char *addr = start;
243 	int result = 0;
244 
245 	if (n >= 1) {
246 		MOVE_BYTE("%0@,%3@");
247 		if (result)
248 			goto out;
249 	}
250 	if (n >= 1 && ((unsigned long)addr & 1)) {
251 		MOVE_BYTE("%0@,%3@");
252 		if (result)
253 			goto out;
254 	}
255 	while (n >= 32)
256 		MOVE_16_WORDS("%0@+,%3@");
257 	while (n >= 2)
258 		MOVE_WORD("%0@+,%3@");
259 	if (result)
260 		return start - addr; /* Negated to indicate uncertain length */
261 	if (n == 1)
262 		MOVE_BYTE("%0@,%3@");
263 out:
264 	return addr - start;
265 }
266 
267 /* The "SCSI DMA" chip on the IIfx implements this register. */
268 #define CTRL_REG                0x8
269 #define CTRL_INTERRUPTS_ENABLE  BIT(1)
270 #define CTRL_HANDSHAKE_MODE     BIT(3)
271 
272 static inline void write_ctrl_reg(struct NCR5380_hostdata *hostdata, u32 value)
273 {
274 	out_be32(hostdata->io + (CTRL_REG << 4), value);
275 }
276 
277 static inline int macscsi_pread(struct NCR5380_hostdata *hostdata,
278                                 unsigned char *dst, int len)
279 {
280 	u8 __iomem *s = hostdata->pdma_io + (INPUT_DATA_REG << 4);
281 	unsigned char *d = dst;
282 	int result = 0;
283 
284 	hostdata->pdma_residual = len;
285 
286 	while (!NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG,
287 	                              BASR_DRQ | BASR_PHASE_MATCH,
288 	                              BASR_DRQ | BASR_PHASE_MATCH, 0)) {
289 		int bytes;
290 
291 		if (macintosh_config->ident == MAC_MODEL_IIFX)
292 			write_ctrl_reg(hostdata, CTRL_HANDSHAKE_MODE |
293 			                         CTRL_INTERRUPTS_ENABLE);
294 
295 		bytes = mac_pdma_recv(s, d, min(hostdata->pdma_residual, 512));
296 
297 		if (bytes > 0) {
298 			d += bytes;
299 			hostdata->pdma_residual -= bytes;
300 		}
301 
302 		if (hostdata->pdma_residual == 0)
303 			goto out;
304 
305 		if (NCR5380_poll_politely2(hostdata, STATUS_REG, SR_REQ, SR_REQ,
306 		                           BUS_AND_STATUS_REG, BASR_ACK,
307 		                           BASR_ACK, 0) < 0)
308 			scmd_printk(KERN_DEBUG, hostdata->connected,
309 			            "%s: !REQ and !ACK\n", __func__);
310 		if (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_PHASE_MATCH))
311 			goto out;
312 
313 		if (bytes == 0)
314 			udelay(MAC_PDMA_DELAY);
315 
316 		if (bytes >= 0)
317 			continue;
318 
319 		dsprintk(NDEBUG_PSEUDO_DMA, hostdata->host,
320 		         "%s: bus error (%d/%d)\n", __func__, d - dst, len);
321 		NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host);
322 		result = -1;
323 		goto out;
324 	}
325 
326 	scmd_printk(KERN_ERR, hostdata->connected,
327 	            "%s: phase mismatch or !DRQ\n", __func__);
328 	NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host);
329 	result = -1;
330 out:
331 	if (macintosh_config->ident == MAC_MODEL_IIFX)
332 		write_ctrl_reg(hostdata, CTRL_INTERRUPTS_ENABLE);
333 	return result;
334 }
335 
336 static inline int macscsi_pwrite(struct NCR5380_hostdata *hostdata,
337                                  unsigned char *src, int len)
338 {
339 	unsigned char *s = src;
340 	u8 __iomem *d = hostdata->pdma_io + (OUTPUT_DATA_REG << 4);
341 	int result = 0;
342 
343 	hostdata->pdma_residual = len;
344 
345 	while (!NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG,
346 	                              BASR_DRQ | BASR_PHASE_MATCH,
347 	                              BASR_DRQ | BASR_PHASE_MATCH, 0)) {
348 		int bytes;
349 
350 		if (macintosh_config->ident == MAC_MODEL_IIFX)
351 			write_ctrl_reg(hostdata, CTRL_HANDSHAKE_MODE |
352 			                         CTRL_INTERRUPTS_ENABLE);
353 
354 		bytes = mac_pdma_send(s, d, min(hostdata->pdma_residual, 512));
355 
356 		if (bytes > 0) {
357 			s += bytes;
358 			hostdata->pdma_residual -= bytes;
359 		}
360 
361 		if (hostdata->pdma_residual == 0) {
362 			if (NCR5380_poll_politely(hostdata, TARGET_COMMAND_REG,
363 			                          TCR_LAST_BYTE_SENT,
364 			                          TCR_LAST_BYTE_SENT,
365 			                          0) < 0) {
366 				scmd_printk(KERN_ERR, hostdata->connected,
367 				            "%s: Last Byte Sent timeout\n", __func__);
368 				result = -1;
369 			}
370 			goto out;
371 		}
372 
373 		if (NCR5380_poll_politely2(hostdata, STATUS_REG, SR_REQ, SR_REQ,
374 		                           BUS_AND_STATUS_REG, BASR_ACK,
375 		                           BASR_ACK, 0) < 0)
376 			scmd_printk(KERN_DEBUG, hostdata->connected,
377 			            "%s: !REQ and !ACK\n", __func__);
378 		if (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_PHASE_MATCH))
379 			goto out;
380 
381 		if (bytes == 0)
382 			udelay(MAC_PDMA_DELAY);
383 
384 		if (bytes >= 0)
385 			continue;
386 
387 		dsprintk(NDEBUG_PSEUDO_DMA, hostdata->host,
388 		         "%s: bus error (%d/%d)\n", __func__, s - src, len);
389 		NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host);
390 		result = -1;
391 		goto out;
392 	}
393 
394 	scmd_printk(KERN_ERR, hostdata->connected,
395 	            "%s: phase mismatch or !DRQ\n", __func__);
396 	NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host);
397 	result = -1;
398 out:
399 	if (macintosh_config->ident == MAC_MODEL_IIFX)
400 		write_ctrl_reg(hostdata, CTRL_INTERRUPTS_ENABLE);
401 	return result;
402 }
403 
404 static int macscsi_dma_xfer_len(struct NCR5380_hostdata *hostdata,
405                                 struct scsi_cmnd *cmd)
406 {
407 	if (hostdata->flags & FLAG_NO_PSEUDO_DMA ||
408 	    cmd->SCp.this_residual < setup_use_pdma)
409 		return 0;
410 
411 	return cmd->SCp.this_residual;
412 }
413 
414 static int macscsi_dma_residual(struct NCR5380_hostdata *hostdata)
415 {
416 	return hostdata->pdma_residual;
417 }
418 
419 #include "NCR5380.c"
420 
421 #define DRV_MODULE_NAME         "mac_scsi"
422 #define PFX                     DRV_MODULE_NAME ": "
423 
424 static struct scsi_host_template mac_scsi_template = {
425 	.module			= THIS_MODULE,
426 	.proc_name		= DRV_MODULE_NAME,
427 	.name			= "Macintosh NCR5380 SCSI",
428 	.info			= macscsi_info,
429 	.queuecommand		= macscsi_queue_command,
430 	.eh_abort_handler	= macscsi_abort,
431 	.eh_host_reset_handler	= macscsi_host_reset,
432 	.can_queue		= 16,
433 	.this_id		= 7,
434 	.sg_tablesize		= 1,
435 	.cmd_per_lun		= 2,
436 	.dma_boundary		= PAGE_SIZE - 1,
437 	.cmd_size		= NCR5380_CMD_SIZE,
438 	.max_sectors		= 128,
439 };
440 
441 static int __init mac_scsi_probe(struct platform_device *pdev)
442 {
443 	struct Scsi_Host *instance;
444 	struct NCR5380_hostdata *hostdata;
445 	int error;
446 	int host_flags = 0;
447 	struct resource *irq, *pio_mem, *pdma_mem = NULL;
448 
449 	pio_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
450 	if (!pio_mem)
451 		return -ENODEV;
452 
453 	pdma_mem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
454 
455 	irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
456 
457 	if (!hwreg_present((unsigned char *)pio_mem->start +
458 	                   (STATUS_REG << 4))) {
459 		pr_info(PFX "no device detected at %pap\n", &pio_mem->start);
460 		return -ENODEV;
461 	}
462 
463 	if (setup_can_queue > 0)
464 		mac_scsi_template.can_queue = setup_can_queue;
465 	if (setup_cmd_per_lun > 0)
466 		mac_scsi_template.cmd_per_lun = setup_cmd_per_lun;
467 	if (setup_sg_tablesize > 0)
468 		mac_scsi_template.sg_tablesize = setup_sg_tablesize;
469 	if (setup_hostid >= 0)
470 		mac_scsi_template.this_id = setup_hostid & 7;
471 
472 	instance = scsi_host_alloc(&mac_scsi_template,
473 	                           sizeof(struct NCR5380_hostdata));
474 	if (!instance)
475 		return -ENOMEM;
476 
477 	if (irq)
478 		instance->irq = irq->start;
479 	else
480 		instance->irq = NO_IRQ;
481 
482 	hostdata = shost_priv(instance);
483 	hostdata->base = pio_mem->start;
484 	hostdata->io = (u8 __iomem *)pio_mem->start;
485 
486 	if (pdma_mem && setup_use_pdma)
487 		hostdata->pdma_io = (u8 __iomem *)pdma_mem->start;
488 	else
489 		host_flags |= FLAG_NO_PSEUDO_DMA;
490 
491 	host_flags |= setup_toshiba_delay > 0 ? FLAG_TOSHIBA_DELAY : 0;
492 
493 	error = NCR5380_init(instance, host_flags | FLAG_LATE_DMA_SETUP);
494 	if (error)
495 		goto fail_init;
496 
497 	if (instance->irq != NO_IRQ) {
498 		error = request_irq(instance->irq, macscsi_intr, IRQF_SHARED,
499 		                    "NCR5380", instance);
500 		if (error)
501 			goto fail_irq;
502 	}
503 
504 	NCR5380_maybe_reset_bus(instance);
505 
506 	error = scsi_add_host(instance, NULL);
507 	if (error)
508 		goto fail_host;
509 
510 	platform_set_drvdata(pdev, instance);
511 
512 	scsi_scan_host(instance);
513 	return 0;
514 
515 fail_host:
516 	if (instance->irq != NO_IRQ)
517 		free_irq(instance->irq, instance);
518 fail_irq:
519 	NCR5380_exit(instance);
520 fail_init:
521 	scsi_host_put(instance);
522 	return error;
523 }
524 
525 static int __exit mac_scsi_remove(struct platform_device *pdev)
526 {
527 	struct Scsi_Host *instance = platform_get_drvdata(pdev);
528 
529 	scsi_remove_host(instance);
530 	if (instance->irq != NO_IRQ)
531 		free_irq(instance->irq, instance);
532 	NCR5380_exit(instance);
533 	scsi_host_put(instance);
534 	return 0;
535 }
536 
537 static struct platform_driver mac_scsi_driver = {
538 	.remove = __exit_p(mac_scsi_remove),
539 	.driver = {
540 		.name	= DRV_MODULE_NAME,
541 	},
542 };
543 
544 module_platform_driver_probe(mac_scsi_driver, mac_scsi_probe);
545 
546 MODULE_ALIAS("platform:" DRV_MODULE_NAME);
547 MODULE_LICENSE("GPL");
548