Training courses

Kernel and Embedded Linux

Bootlin training courses

Embedded Linux, kernel,
Yocto Project, Buildroot, real-time,
graphics, boot time, debugging...

Bootlin logo

Elixir Cross Referencer

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Generic Macintosh NCR5380 driver
 *
 * Copyright 1998, Michael Schmitz <mschmitz@lbl.gov>
 *
 * Copyright 2019 Finn Thain
 *
 * derived in part from:
 */
/*
 * Generic Generic NCR5380 driver
 *
 * Copyright 1995, Russell King
 */

#include <linux/delay.h>
#include <linux/types.h>
#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>

#include <asm/hwtest.h>
#include <asm/io.h>
#include <asm/macintosh.h>
#include <asm/macints.h>
#include <asm/setup.h>

#include <scsi/scsi_host.h>

/* Definitions for the core NCR5380 driver. */

#define NCR5380_implementation_fields   int pdma_residual

#define NCR5380_read(reg)           in_8(hostdata->io + ((reg) << 4))
#define NCR5380_write(reg, value)   out_8(hostdata->io + ((reg) << 4), value)

#define NCR5380_dma_xfer_len            macscsi_dma_xfer_len
#define NCR5380_dma_recv_setup          macscsi_pread
#define NCR5380_dma_send_setup          macscsi_pwrite
#define NCR5380_dma_residual            macscsi_dma_residual

#define NCR5380_intr                    macscsi_intr
#define NCR5380_queue_command           macscsi_queue_command
#define NCR5380_abort                   macscsi_abort
#define NCR5380_host_reset              macscsi_host_reset
#define NCR5380_info                    macscsi_info

#include "NCR5380.h"

static int setup_can_queue = -1;
module_param(setup_can_queue, int, 0);
static int setup_cmd_per_lun = -1;
module_param(setup_cmd_per_lun, int, 0);
static int setup_sg_tablesize = -1;
module_param(setup_sg_tablesize, int, 0);
static int setup_use_pdma = 512;
module_param(setup_use_pdma, int, 0);
static int setup_hostid = -1;
module_param(setup_hostid, int, 0);
static int setup_toshiba_delay = -1;
module_param(setup_toshiba_delay, int, 0);

#ifndef MODULE
static int __init mac_scsi_setup(char *str)
{
	int ints[8];

	(void)get_options(str, ARRAY_SIZE(ints), ints);

	if (ints[0] < 1) {
		pr_err("Usage: mac5380=<can_queue>[,<cmd_per_lun>[,<sg_tablesize>[,<hostid>[,<use_tags>[,<use_pdma>[,<toshiba_delay>]]]]]]\n");
		return 0;
	}
	if (ints[0] >= 1)
		setup_can_queue = ints[1];
	if (ints[0] >= 2)
		setup_cmd_per_lun = ints[2];
	if (ints[0] >= 3)
		setup_sg_tablesize = ints[3];
	if (ints[0] >= 4)
		setup_hostid = ints[4];
	/* ints[5] (use_tagged_queuing) is ignored */
	if (ints[0] >= 6)
		setup_use_pdma = ints[6];
	if (ints[0] >= 7)
		setup_toshiba_delay = ints[7];
	return 1;
}

__setup("mac5380=", mac_scsi_setup);
#endif /* !MODULE */

/*
 * According to "Inside Macintosh: Devices", Mac OS requires disk drivers to
 * specify the number of bytes between the delays expected from a SCSI target.
 * This allows the operating system to "prevent bus errors when a target fails
 * to deliver the next byte within the processor bus error timeout period."
 * Linux SCSI drivers lack knowledge of the timing behaviour of SCSI targets
 * so bus errors are unavoidable.
 *
 * If a MOVE.B instruction faults, we assume that zero bytes were transferred
 * and simply retry. That assumption probably depends on target behaviour but
 * seems to hold up okay. The NOP provides synchronization: without it the
 * fault can sometimes occur after the program counter has moved past the
 * offending instruction. Post-increment addressing can't be used.
 */

#define MOVE_BYTE(operands) \
	asm volatile ( \
		"1:     moveb " operands "     \n" \
		"11:    nop                    \n" \
		"       addq #1,%0             \n" \
		"       subq #1,%1             \n" \
		"40:                           \n" \
		"                              \n" \
		".section .fixup,\"ax\"        \n" \
		".even                         \n" \
		"90:    movel #1, %2           \n" \
		"       jra 40b                \n" \
		".previous                     \n" \
		"                              \n" \
		".section __ex_table,\"a\"     \n" \
		".align  4                     \n" \
		".long   1b,90b                \n" \
		".long  11b,90b                \n" \
		".previous                     \n" \
		: "+a" (addr), "+r" (n), "+r" (result) : "a" (io))

/*
 * If a MOVE.W (or MOVE.L) instruction faults, it cannot be retried because
 * the residual byte count would be uncertain. In that situation the MOVE_WORD
 * macro clears n in the fixup section to abort the transfer.
 */

#define MOVE_WORD(operands) \
	asm volatile ( \
		"1:     movew " operands "     \n" \
		"11:    nop                    \n" \
		"       subq #2,%1             \n" \
		"40:                           \n" \
		"                              \n" \
		".section .fixup,\"ax\"        \n" \
		".even                         \n" \
		"90:    movel #0, %1           \n" \
		"       movel #2, %2           \n" \
		"       jra 40b                \n" \
		".previous                     \n" \
		"                              \n" \
		".section __ex_table,\"a\"     \n" \
		".align  4                     \n" \
		".long   1b,90b                \n" \
		".long  11b,90b                \n" \
		".previous                     \n" \
		: "+a" (addr), "+r" (n), "+r" (result) : "a" (io))

#define MOVE_16_WORDS(operands) \
	asm volatile ( \
		"1:     movew " operands "     \n" \
		"2:     movew " operands "     \n" \
		"3:     movew " operands "     \n" \
		"4:     movew " operands "     \n" \
		"5:     movew " operands "     \n" \
		"6:     movew " operands "     \n" \
		"7:     movew " operands "     \n" \
		"8:     movew " operands "     \n" \
		"9:     movew " operands "     \n" \
		"10:    movew " operands "     \n" \
		"11:    movew " operands "     \n" \
		"12:    movew " operands "     \n" \
		"13:    movew " operands "     \n" \
		"14:    movew " operands "     \n" \
		"15:    movew " operands "     \n" \
		"16:    movew " operands "     \n" \
		"17:    nop                    \n" \
		"       subl  #32,%1           \n" \
		"40:                           \n" \
		"                              \n" \
		".section .fixup,\"ax\"        \n" \
		".even                         \n" \
		"90:    movel #0, %1           \n" \
		"       movel #2, %2           \n" \
		"       jra 40b                \n" \
		".previous                     \n" \
		"                              \n" \
		".section __ex_table,\"a\"     \n" \
		".align  4                     \n" \
		".long   1b,90b                \n" \
		".long   2b,90b                \n" \
		".long   3b,90b                \n" \
		".long   4b,90b                \n" \
		".long   5b,90b                \n" \
		".long   6b,90b                \n" \
		".long   7b,90b                \n" \
		".long   8b,90b                \n" \
		".long   9b,90b                \n" \
		".long  10b,90b                \n" \
		".long  11b,90b                \n" \
		".long  12b,90b                \n" \
		".long  13b,90b                \n" \
		".long  14b,90b                \n" \
		".long  15b,90b                \n" \
		".long  16b,90b                \n" \
		".long  17b,90b                \n" \
		".previous                     \n" \
		: "+a" (addr), "+r" (n), "+r" (result) : "a" (io))

#define MAC_PDMA_DELAY		32

static inline int mac_pdma_recv(void __iomem *io, unsigned char *start, int n)
{
	unsigned char *addr = start;
	int result = 0;

	if (n >= 1) {
		MOVE_BYTE("%3@,%0@");
		if (result)
			goto out;
	}
	if (n >= 1 && ((unsigned long)addr & 1)) {
		MOVE_BYTE("%3@,%0@");
		if (result)
			goto out;
	}
	while (n >= 32)
		MOVE_16_WORDS("%3@,%0@+");
	while (n >= 2)
		MOVE_WORD("%3@,%0@+");
	if (result)
		return start - addr; /* Negated to indicate uncertain length */
	if (n == 1)
		MOVE_BYTE("%3@,%0@");
out:
	return addr - start;
}

static inline int mac_pdma_send(unsigned char *start, void __iomem *io, int n)
{
	unsigned char *addr = start;
	int result = 0;

	if (n >= 1) {
		MOVE_BYTE("%0@,%3@");
		if (result)
			goto out;
	}
	if (n >= 1 && ((unsigned long)addr & 1)) {
		MOVE_BYTE("%0@,%3@");
		if (result)
			goto out;
	}
	while (n >= 32)
		MOVE_16_WORDS("%0@+,%3@");
	while (n >= 2)
		MOVE_WORD("%0@+,%3@");
	if (result)
		return start - addr; /* Negated to indicate uncertain length */
	if (n == 1)
		MOVE_BYTE("%0@,%3@");
out:
	return addr - start;
}

/* The "SCSI DMA" chip on the IIfx implements this register. */
#define CTRL_REG                0x8
#define CTRL_INTERRUPTS_ENABLE  BIT(1)
#define CTRL_HANDSHAKE_MODE     BIT(3)

static inline void write_ctrl_reg(struct NCR5380_hostdata *hostdata, u32 value)
{
	out_be32(hostdata->io + (CTRL_REG << 4), value);
}

static inline int macscsi_pread(struct NCR5380_hostdata *hostdata,
                                unsigned char *dst, int len)
{
	u8 __iomem *s = hostdata->pdma_io + (INPUT_DATA_REG << 4);
	unsigned char *d = dst;
	int result = 0;

	hostdata->pdma_residual = len;

	while (!NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG,
	                              BASR_DRQ | BASR_PHASE_MATCH,
	                              BASR_DRQ | BASR_PHASE_MATCH, HZ / 64)) {
		int bytes;

		if (macintosh_config->ident == MAC_MODEL_IIFX)
			write_ctrl_reg(hostdata, CTRL_HANDSHAKE_MODE |
			                         CTRL_INTERRUPTS_ENABLE);

		bytes = mac_pdma_recv(s, d, min(hostdata->pdma_residual, 512));

		if (bytes > 0) {
			d += bytes;
			hostdata->pdma_residual -= bytes;
		}

		if (hostdata->pdma_residual == 0)
			goto out;

		if (NCR5380_poll_politely2(hostdata, STATUS_REG, SR_REQ, SR_REQ,
		                           BUS_AND_STATUS_REG, BASR_ACK,
		                           BASR_ACK, HZ / 64) < 0)
			scmd_printk(KERN_DEBUG, hostdata->connected,
			            "%s: !REQ and !ACK\n", __func__);
		if (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_PHASE_MATCH))
			goto out;

		if (bytes == 0)
			udelay(MAC_PDMA_DELAY);

		if (bytes >= 0)
			continue;

		dsprintk(NDEBUG_PSEUDO_DMA, hostdata->host,
		         "%s: bus error (%d/%d)\n", __func__, d - dst, len);
		NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host);
		result = -1;
		goto out;
	}

	scmd_printk(KERN_ERR, hostdata->connected,
	            "%s: phase mismatch or !DRQ\n", __func__);
	NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host);
	result = -1;
out:
	if (macintosh_config->ident == MAC_MODEL_IIFX)
		write_ctrl_reg(hostdata, CTRL_INTERRUPTS_ENABLE);
	return result;
}

static inline int macscsi_pwrite(struct NCR5380_hostdata *hostdata,
                                 unsigned char *src, int len)
{
	unsigned char *s = src;
	u8 __iomem *d = hostdata->pdma_io + (OUTPUT_DATA_REG << 4);
	int result = 0;

	hostdata->pdma_residual = len;

	while (!NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG,
	                              BASR_DRQ | BASR_PHASE_MATCH,
	                              BASR_DRQ | BASR_PHASE_MATCH, HZ / 64)) {
		int bytes;

		if (macintosh_config->ident == MAC_MODEL_IIFX)
			write_ctrl_reg(hostdata, CTRL_HANDSHAKE_MODE |
			                         CTRL_INTERRUPTS_ENABLE);

		bytes = mac_pdma_send(s, d, min(hostdata->pdma_residual, 512));

		if (bytes > 0) {
			s += bytes;
			hostdata->pdma_residual -= bytes;
		}

		if (hostdata->pdma_residual == 0) {
			if (NCR5380_poll_politely(hostdata, TARGET_COMMAND_REG,
			                          TCR_LAST_BYTE_SENT,
			                          TCR_LAST_BYTE_SENT,
			                          HZ / 64) < 0) {
				scmd_printk(KERN_ERR, hostdata->connected,
				            "%s: Last Byte Sent timeout\n", __func__);
				result = -1;
			}
			goto out;
		}

		if (NCR5380_poll_politely2(hostdata, STATUS_REG, SR_REQ, SR_REQ,
		                           BUS_AND_STATUS_REG, BASR_ACK,
		                           BASR_ACK, HZ / 64) < 0)
			scmd_printk(KERN_DEBUG, hostdata->connected,
			            "%s: !REQ and !ACK\n", __func__);
		if (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_PHASE_MATCH))
			goto out;

		if (bytes == 0)
			udelay(MAC_PDMA_DELAY);

		if (bytes >= 0)
			continue;

		dsprintk(NDEBUG_PSEUDO_DMA, hostdata->host,
		         "%s: bus error (%d/%d)\n", __func__, s - src, len);
		NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host);
		result = -1;
		goto out;
	}

	scmd_printk(KERN_ERR, hostdata->connected,
	            "%s: phase mismatch or !DRQ\n", __func__);
	NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host);
	result = -1;
out:
	if (macintosh_config->ident == MAC_MODEL_IIFX)
		write_ctrl_reg(hostdata, CTRL_INTERRUPTS_ENABLE);
	return result;
}

static int macscsi_dma_xfer_len(struct NCR5380_hostdata *hostdata,
                                struct scsi_cmnd *cmd)
{
	if (hostdata->flags & FLAG_NO_PSEUDO_DMA ||
	    cmd->SCp.this_residual < setup_use_pdma)
		return 0;

	return cmd->SCp.this_residual;
}

static int macscsi_dma_residual(struct NCR5380_hostdata *hostdata)
{
	return hostdata->pdma_residual;
}

#include "NCR5380.c"

#define DRV_MODULE_NAME         "mac_scsi"
#define PFX                     DRV_MODULE_NAME ": "

static struct scsi_host_template mac_scsi_template = {
	.module			= THIS_MODULE,
	.proc_name		= DRV_MODULE_NAME,
	.name			= "Macintosh NCR5380 SCSI",
	.info			= macscsi_info,
	.queuecommand		= macscsi_queue_command,
	.eh_abort_handler	= macscsi_abort,
	.eh_host_reset_handler	= macscsi_host_reset,
	.can_queue		= 16,
	.this_id		= 7,
	.sg_tablesize		= 1,
	.cmd_per_lun		= 2,
	.dma_boundary		= PAGE_SIZE - 1,
	.cmd_size		= NCR5380_CMD_SIZE,
	.max_sectors		= 128,
};

static int __init mac_scsi_probe(struct platform_device *pdev)
{
	struct Scsi_Host *instance;
	struct NCR5380_hostdata *hostdata;
	int error;
	int host_flags = 0;
	struct resource *irq, *pio_mem, *pdma_mem = NULL;

	pio_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!pio_mem)
		return -ENODEV;

	pdma_mem = platform_get_resource(pdev, IORESOURCE_MEM, 1);

	irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);

	if (!hwreg_present((unsigned char *)pio_mem->start +
	                   (STATUS_REG << 4))) {
		pr_info(PFX "no device detected at %pap\n", &pio_mem->start);
		return -ENODEV;
	}

	if (setup_can_queue > 0)
		mac_scsi_template.can_queue = setup_can_queue;
	if (setup_cmd_per_lun > 0)
		mac_scsi_template.cmd_per_lun = setup_cmd_per_lun;
	if (setup_sg_tablesize >= 0)
		mac_scsi_template.sg_tablesize = setup_sg_tablesize;
	if (setup_hostid >= 0)
		mac_scsi_template.this_id = setup_hostid & 7;

	instance = scsi_host_alloc(&mac_scsi_template,
	                           sizeof(struct NCR5380_hostdata));
	if (!instance)
		return -ENOMEM;

	if (irq)
		instance->irq = irq->start;
	else
		instance->irq = NO_IRQ;

	hostdata = shost_priv(instance);
	hostdata->base = pio_mem->start;
	hostdata->io = (u8 __iomem *)pio_mem->start;

	if (pdma_mem && setup_use_pdma)
		hostdata->pdma_io = (u8 __iomem *)pdma_mem->start;
	else
		host_flags |= FLAG_NO_PSEUDO_DMA;

	host_flags |= setup_toshiba_delay > 0 ? FLAG_TOSHIBA_DELAY : 0;

	error = NCR5380_init(instance, host_flags | FLAG_LATE_DMA_SETUP);
	if (error)
		goto fail_init;

	if (instance->irq != NO_IRQ) {
		error = request_irq(instance->irq, macscsi_intr, IRQF_SHARED,
		                    "NCR5380", instance);
		if (error)
			goto fail_irq;
	}

	NCR5380_maybe_reset_bus(instance);

	error = scsi_add_host(instance, NULL);
	if (error)
		goto fail_host;

	platform_set_drvdata(pdev, instance);

	scsi_scan_host(instance);
	return 0;

fail_host:
	if (instance->irq != NO_IRQ)
		free_irq(instance->irq, instance);
fail_irq:
	NCR5380_exit(instance);
fail_init:
	scsi_host_put(instance);
	return error;
}

static int __exit mac_scsi_remove(struct platform_device *pdev)
{
	struct Scsi_Host *instance = platform_get_drvdata(pdev);

	scsi_remove_host(instance);
	if (instance->irq != NO_IRQ)
		free_irq(instance->irq, instance);
	NCR5380_exit(instance);
	scsi_host_put(instance);
	return 0;
}

static struct platform_driver mac_scsi_driver = {
	.remove = __exit_p(mac_scsi_remove),
	.driver = {
		.name	= DRV_MODULE_NAME,
	},
};

module_platform_driver_probe(mac_scsi_driver, mac_scsi_probe);

MODULE_ALIAS("platform:" DRV_MODULE_NAME);
MODULE_LICENSE("GPL");