1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Fake VME bridge support.
4  *
5  * This drive provides a fake VME bridge chip, this enables debugging of the
6  * VME framework in the absence of a VME system.
7  *
8  * This driver has to do a number of things in software that would be driven
9  * by hardware if it was available, it will also result in extra overhead at
10  * times when compared with driving actual hardware.
11  *
12  * Author: Martyn Welch <martyn@welches.me.uk>
13  * Copyright (c) 2014 Martyn Welch
14  *
15  * Based on vme_tsi148.c:
16  *
17  * Author: Martyn Welch <martyn.welch@ge.com>
18  * Copyright 2008 GE Intelligent Platforms Embedded Systems, Inc.
19  *
20  * Based on work by Tom Armistead and Ajit Prem
21  * Copyright 2004 Motorola Inc.
22  */
23 
24 #include <linux/device.h>
25 #include <linux/errno.h>
26 #include <linux/interrupt.h>
27 #include <linux/module.h>
28 #include <linux/moduleparam.h>
29 #include <linux/slab.h>
30 #include <linux/spinlock.h>
31 #include <linux/types.h>
32 
33 #include "vme.h"
34 #include "vme_bridge.h"
35 
36 /*
37  *  Define the number of each that the fake driver supports.
38  */
39 #define FAKE_MAX_MASTER		8	/* Max Master Windows */
40 #define FAKE_MAX_SLAVE		8	/* Max Slave Windows */
41 
42 /* Structures to hold information normally held in device registers */
43 struct fake_slave_window {
44 	int enabled;
45 	unsigned long long vme_base;
46 	unsigned long long size;
47 	void *buf_base;
48 	u32 aspace;
49 	u32 cycle;
50 };
51 
52 struct fake_master_window {
53 	int enabled;
54 	unsigned long long vme_base;
55 	unsigned long long size;
56 	u32 aspace;
57 	u32 cycle;
58 	u32 dwidth;
59 };
60 
61 /* Structure used to hold driver specific information */
62 struct fake_driver {
63 	struct vme_bridge *parent;
64 	struct fake_slave_window slaves[FAKE_MAX_SLAVE];
65 	struct fake_master_window masters[FAKE_MAX_MASTER];
66 	u32 lm_enabled;
67 	unsigned long long lm_base;
68 	u32 lm_aspace;
69 	u32 lm_cycle;
70 	void (*lm_callback[4])(void *);
71 	void *lm_data[4];
72 	struct tasklet_struct int_tasklet;
73 	int int_level;
74 	int int_statid;
75 	void *crcsr_kernel;
76 	dma_addr_t crcsr_bus;
77 	/* Only one VME interrupt can be generated at a time, provide locking */
78 	struct mutex vme_int;
79 };
80 
81 /* Module parameter */
82 static int geoid;
83 
84 static const char driver_name[] = "vme_fake";
85 
86 static struct vme_bridge *exit_pointer;
87 
88 static struct device *vme_root;
89 
90 /*
91  * Calling VME bus interrupt callback if provided.
92  */
93 static void fake_VIRQ_tasklet(unsigned long data)
94 {
95 	struct vme_bridge *fake_bridge;
96 	struct fake_driver *bridge;
97 
98 	fake_bridge = (struct vme_bridge *) data;
99 	bridge = fake_bridge->driver_priv;
100 
101 	vme_irq_handler(fake_bridge, bridge->int_level, bridge->int_statid);
102 }
103 
104 /*
105  * Configure VME interrupt
106  */
107 static void fake_irq_set(struct vme_bridge *fake_bridge, int level,
108 		int state, int sync)
109 {
110 	/* Nothing to do */
111 }
112 
113 static void *fake_pci_to_ptr(dma_addr_t addr)
114 {
115 	return (void *)(uintptr_t)addr;
116 }
117 
118 static dma_addr_t fake_ptr_to_pci(void *addr)
119 {
120 	return (dma_addr_t)(uintptr_t)addr;
121 }
122 
123 /*
124  * Generate a VME bus interrupt at the requested level & vector. Wait for
125  * interrupt to be acked.
126  */
127 static int fake_irq_generate(struct vme_bridge *fake_bridge, int level,
128 		int statid)
129 {
130 	struct fake_driver *bridge;
131 
132 	bridge = fake_bridge->driver_priv;
133 
134 	mutex_lock(&bridge->vme_int);
135 
136 	bridge->int_level = level;
137 
138 	bridge->int_statid = statid;
139 
140 	/*
141 	 * Schedule tasklet to run VME handler to emulate normal VME interrupt
142 	 * handler behaviour.
143 	 */
144 	tasklet_schedule(&bridge->int_tasklet);
145 
146 	mutex_unlock(&bridge->vme_int);
147 
148 	return 0;
149 }
150 
151 /*
152  * Initialize a slave window with the requested attributes.
153  */
154 static int fake_slave_set(struct vme_slave_resource *image, int enabled,
155 		unsigned long long vme_base, unsigned long long size,
156 		dma_addr_t buf_base, u32 aspace, u32 cycle)
157 {
158 	unsigned int i, granularity = 0;
159 	unsigned long long vme_bound;
160 	struct vme_bridge *fake_bridge;
161 	struct fake_driver *bridge;
162 
163 	fake_bridge = image->parent;
164 	bridge = fake_bridge->driver_priv;
165 
166 	i = image->number;
167 
168 	switch (aspace) {
169 	case VME_A16:
170 		granularity = 0x10;
171 		break;
172 	case VME_A24:
173 		granularity = 0x1000;
174 		break;
175 	case VME_A32:
176 		granularity = 0x10000;
177 		break;
178 	case VME_A64:
179 		granularity = 0x10000;
180 		break;
181 	case VME_CRCSR:
182 	case VME_USER1:
183 	case VME_USER2:
184 	case VME_USER3:
185 	case VME_USER4:
186 	default:
187 		pr_err("Invalid address space\n");
188 		return -EINVAL;
189 	}
190 
191 	/*
192 	 * Bound address is a valid address for the window, adjust
193 	 * accordingly
194 	 */
195 	vme_bound = vme_base + size - granularity;
196 
197 	if (vme_base & (granularity - 1)) {
198 		pr_err("Invalid VME base alignment\n");
199 		return -EINVAL;
200 	}
201 	if (vme_bound & (granularity - 1)) {
202 		pr_err("Invalid VME bound alignment\n");
203 		return -EINVAL;
204 	}
205 
206 	mutex_lock(&image->mtx);
207 
208 	bridge->slaves[i].enabled = enabled;
209 	bridge->slaves[i].vme_base = vme_base;
210 	bridge->slaves[i].size = size;
211 	bridge->slaves[i].buf_base = fake_pci_to_ptr(buf_base);
212 	bridge->slaves[i].aspace = aspace;
213 	bridge->slaves[i].cycle = cycle;
214 
215 	mutex_unlock(&image->mtx);
216 
217 	return 0;
218 }
219 
220 /*
221  * Get slave window configuration.
222  */
223 static int fake_slave_get(struct vme_slave_resource *image, int *enabled,
224 		unsigned long long *vme_base, unsigned long long *size,
225 		dma_addr_t *buf_base, u32 *aspace, u32 *cycle)
226 {
227 	unsigned int i;
228 	struct fake_driver *bridge;
229 
230 	bridge = image->parent->driver_priv;
231 
232 	i = image->number;
233 
234 	mutex_lock(&image->mtx);
235 
236 	*enabled = bridge->slaves[i].enabled;
237 	*vme_base = bridge->slaves[i].vme_base;
238 	*size = bridge->slaves[i].size;
239 	*buf_base = fake_ptr_to_pci(bridge->slaves[i].buf_base);
240 	*aspace = bridge->slaves[i].aspace;
241 	*cycle = bridge->slaves[i].cycle;
242 
243 	mutex_unlock(&image->mtx);
244 
245 	return 0;
246 }
247 
248 /*
249  * Set the attributes of an outbound window.
250  */
251 static int fake_master_set(struct vme_master_resource *image, int enabled,
252 		unsigned long long vme_base, unsigned long long size,
253 		u32 aspace, u32 cycle, u32 dwidth)
254 {
255 	int retval = 0;
256 	unsigned int i;
257 	struct vme_bridge *fake_bridge;
258 	struct fake_driver *bridge;
259 
260 	fake_bridge = image->parent;
261 
262 	bridge = fake_bridge->driver_priv;
263 
264 	/* Verify input data */
265 	if (vme_base & 0xFFFF) {
266 		pr_err("Invalid VME Window alignment\n");
267 		retval = -EINVAL;
268 		goto err_window;
269 	}
270 
271 	if (size & 0xFFFF) {
272 		pr_err("Invalid size alignment\n");
273 		retval = -EINVAL;
274 		goto err_window;
275 	}
276 
277 	if ((size == 0) && (enabled != 0)) {
278 		pr_err("Size must be non-zero for enabled windows\n");
279 		retval = -EINVAL;
280 		goto err_window;
281 	}
282 
283 	/* Setup data width */
284 	switch (dwidth) {
285 	case VME_D8:
286 	case VME_D16:
287 	case VME_D32:
288 		break;
289 	default:
290 		pr_err("Invalid data width\n");
291 		retval = -EINVAL;
292 		goto err_dwidth;
293 	}
294 
295 	/* Setup address space */
296 	switch (aspace) {
297 	case VME_A16:
298 	case VME_A24:
299 	case VME_A32:
300 	case VME_A64:
301 	case VME_CRCSR:
302 	case VME_USER1:
303 	case VME_USER2:
304 	case VME_USER3:
305 	case VME_USER4:
306 		break;
307 	default:
308 		pr_err("Invalid address space\n");
309 		retval = -EINVAL;
310 		goto err_aspace;
311 	}
312 
313 	spin_lock(&image->lock);
314 
315 	i = image->number;
316 
317 	bridge->masters[i].enabled = enabled;
318 	bridge->masters[i].vme_base = vme_base;
319 	bridge->masters[i].size = size;
320 	bridge->masters[i].aspace = aspace;
321 	bridge->masters[i].cycle = cycle;
322 	bridge->masters[i].dwidth = dwidth;
323 
324 	spin_unlock(&image->lock);
325 
326 	return 0;
327 
328 err_aspace:
329 err_dwidth:
330 err_window:
331 	return retval;
332 
333 }
334 
335 /*
336  * Set the attributes of an outbound window.
337  */
338 static int __fake_master_get(struct vme_master_resource *image, int *enabled,
339 		unsigned long long *vme_base, unsigned long long *size,
340 		u32 *aspace, u32 *cycle, u32 *dwidth)
341 {
342 	unsigned int i;
343 	struct fake_driver *bridge;
344 
345 	bridge = image->parent->driver_priv;
346 
347 	i = image->number;
348 
349 	*enabled = bridge->masters[i].enabled;
350 	*vme_base = bridge->masters[i].vme_base;
351 	*size = bridge->masters[i].size;
352 	*aspace = bridge->masters[i].aspace;
353 	*cycle = bridge->masters[i].cycle;
354 	*dwidth = bridge->masters[i].dwidth;
355 
356 	return 0;
357 }
358 
359 
360 static int fake_master_get(struct vme_master_resource *image, int *enabled,
361 		unsigned long long *vme_base, unsigned long long *size,
362 		u32 *aspace, u32 *cycle, u32 *dwidth)
363 {
364 	int retval;
365 
366 	spin_lock(&image->lock);
367 
368 	retval = __fake_master_get(image, enabled, vme_base, size, aspace,
369 			cycle, dwidth);
370 
371 	spin_unlock(&image->lock);
372 
373 	return retval;
374 }
375 
376 
377 static void fake_lm_check(struct fake_driver *bridge, unsigned long long addr,
378 			  u32 aspace, u32 cycle)
379 {
380 	struct vme_bridge *fake_bridge;
381 	unsigned long long lm_base;
382 	u32 lm_aspace, lm_cycle;
383 	int i;
384 	struct vme_lm_resource *lm;
385 	struct list_head *pos = NULL, *n;
386 
387 	/* Get vme_bridge */
388 	fake_bridge = bridge->parent;
389 
390 	/* Loop through each location monitor resource */
391 	list_for_each_safe(pos, n, &fake_bridge->lm_resources) {
392 		lm = list_entry(pos, struct vme_lm_resource, list);
393 
394 		/* If disabled, we're done */
395 		if (bridge->lm_enabled == 0)
396 			return;
397 
398 		lm_base = bridge->lm_base;
399 		lm_aspace = bridge->lm_aspace;
400 		lm_cycle = bridge->lm_cycle;
401 
402 		/* First make sure that the cycle and address space match */
403 		if ((lm_aspace == aspace) && (lm_cycle == cycle)) {
404 			for (i = 0; i < lm->monitors; i++) {
405 				/* Each location monitor covers 8 bytes */
406 				if (((lm_base + (8 * i)) <= addr) &&
407 				    ((lm_base + (8 * i) + 8) > addr)) {
408 					if (bridge->lm_callback[i])
409 						bridge->lm_callback[i](
410 							bridge->lm_data[i]);
411 				}
412 			}
413 		}
414 	}
415 }
416 
417 static noinline_for_stack u8 fake_vmeread8(struct fake_driver *bridge,
418 					   unsigned long long addr,
419 					   u32 aspace, u32 cycle)
420 {
421 	u8 retval = 0xff;
422 	int i;
423 	unsigned long long start, end, offset;
424 	u8 *loc;
425 
426 	for (i = 0; i < FAKE_MAX_SLAVE; i++) {
427 		start = bridge->slaves[i].vme_base;
428 		end = bridge->slaves[i].vme_base + bridge->slaves[i].size;
429 
430 		if (aspace != bridge->slaves[i].aspace)
431 			continue;
432 
433 		if (cycle != bridge->slaves[i].cycle)
434 			continue;
435 
436 		if ((addr >= start) && (addr < end)) {
437 			offset = addr - bridge->slaves[i].vme_base;
438 			loc = (u8 *)(bridge->slaves[i].buf_base + offset);
439 			retval = *loc;
440 
441 			break;
442 		}
443 	}
444 
445 	fake_lm_check(bridge, addr, aspace, cycle);
446 
447 	return retval;
448 }
449 
450 static noinline_for_stack u16 fake_vmeread16(struct fake_driver *bridge,
451 					     unsigned long long addr,
452 					     u32 aspace, u32 cycle)
453 {
454 	u16 retval = 0xffff;
455 	int i;
456 	unsigned long long start, end, offset;
457 	u16 *loc;
458 
459 	for (i = 0; i < FAKE_MAX_SLAVE; i++) {
460 		if (aspace != bridge->slaves[i].aspace)
461 			continue;
462 
463 		if (cycle != bridge->slaves[i].cycle)
464 			continue;
465 
466 		start = bridge->slaves[i].vme_base;
467 		end = bridge->slaves[i].vme_base + bridge->slaves[i].size;
468 
469 		if ((addr >= start) && ((addr + 1) < end)) {
470 			offset = addr - bridge->slaves[i].vme_base;
471 			loc = (u16 *)(bridge->slaves[i].buf_base + offset);
472 			retval = *loc;
473 
474 			break;
475 		}
476 	}
477 
478 	fake_lm_check(bridge, addr, aspace, cycle);
479 
480 	return retval;
481 }
482 
483 static noinline_for_stack u32 fake_vmeread32(struct fake_driver *bridge,
484 					     unsigned long long addr,
485 					     u32 aspace, u32 cycle)
486 {
487 	u32 retval = 0xffffffff;
488 	int i;
489 	unsigned long long start, end, offset;
490 	u32 *loc;
491 
492 	for (i = 0; i < FAKE_MAX_SLAVE; i++) {
493 		if (aspace != bridge->slaves[i].aspace)
494 			continue;
495 
496 		if (cycle != bridge->slaves[i].cycle)
497 			continue;
498 
499 		start = bridge->slaves[i].vme_base;
500 		end = bridge->slaves[i].vme_base + bridge->slaves[i].size;
501 
502 		if ((addr >= start) && ((addr + 3) < end)) {
503 			offset = addr - bridge->slaves[i].vme_base;
504 			loc = (u32 *)(bridge->slaves[i].buf_base + offset);
505 			retval = *loc;
506 
507 			break;
508 		}
509 	}
510 
511 	fake_lm_check(bridge, addr, aspace, cycle);
512 
513 	return retval;
514 }
515 
516 static ssize_t fake_master_read(struct vme_master_resource *image, void *buf,
517 		size_t count, loff_t offset)
518 {
519 	int retval;
520 	u32 aspace, cycle, dwidth;
521 	struct vme_bridge *fake_bridge;
522 	struct fake_driver *priv;
523 	int i;
524 	unsigned long long addr;
525 	unsigned int done = 0;
526 	unsigned int count32;
527 
528 	fake_bridge = image->parent;
529 
530 	priv = fake_bridge->driver_priv;
531 
532 	i = image->number;
533 
534 	addr = (unsigned long long)priv->masters[i].vme_base + offset;
535 	aspace = priv->masters[i].aspace;
536 	cycle = priv->masters[i].cycle;
537 	dwidth = priv->masters[i].dwidth;
538 
539 	spin_lock(&image->lock);
540 
541 	/* The following code handles VME address alignment. We cannot use
542 	 * memcpy_xxx here because it may cut data transfers in to 8-bit
543 	 * cycles when D16 or D32 cycles are required on the VME bus.
544 	 * On the other hand, the bridge itself assures that the maximum data
545 	 * cycle configured for the transfer is used and splits it
546 	 * automatically for non-aligned addresses, so we don't want the
547 	 * overhead of needlessly forcing small transfers for the entire cycle.
548 	 */
549 	if (addr & 0x1) {
550 		*(u8 *)buf = fake_vmeread8(priv, addr, aspace, cycle);
551 		done += 1;
552 		if (done == count)
553 			goto out;
554 	}
555 	if ((dwidth == VME_D16) || (dwidth == VME_D32)) {
556 		if ((addr + done) & 0x2) {
557 			if ((count - done) < 2) {
558 				*(u8 *)(buf + done) = fake_vmeread8(priv,
559 						addr + done, aspace, cycle);
560 				done += 1;
561 				goto out;
562 			} else {
563 				*(u16 *)(buf + done) = fake_vmeread16(priv,
564 						addr + done, aspace, cycle);
565 				done += 2;
566 			}
567 		}
568 	}
569 
570 	if (dwidth == VME_D32) {
571 		count32 = (count - done) & ~0x3;
572 		while (done < count32) {
573 			*(u32 *)(buf + done) = fake_vmeread32(priv, addr + done,
574 					aspace, cycle);
575 			done += 4;
576 		}
577 	} else if (dwidth == VME_D16) {
578 		count32 = (count - done) & ~0x3;
579 		while (done < count32) {
580 			*(u16 *)(buf + done) = fake_vmeread16(priv, addr + done,
581 					aspace, cycle);
582 			done += 2;
583 		}
584 	} else if (dwidth == VME_D8) {
585 		count32 = (count - done);
586 		while (done < count32) {
587 			*(u8 *)(buf + done) = fake_vmeread8(priv, addr + done,
588 					aspace, cycle);
589 			done += 1;
590 		}
591 
592 	}
593 
594 	if ((dwidth == VME_D16) || (dwidth == VME_D32)) {
595 		if ((count - done) & 0x2) {
596 			*(u16 *)(buf + done) = fake_vmeread16(priv, addr + done,
597 					aspace, cycle);
598 			done += 2;
599 		}
600 	}
601 	if ((count - done) & 0x1) {
602 		*(u8 *)(buf + done) = fake_vmeread8(priv, addr + done, aspace,
603 				cycle);
604 		done += 1;
605 	}
606 
607 out:
608 	retval = count;
609 
610 	spin_unlock(&image->lock);
611 
612 	return retval;
613 }
614 
615 static noinline_for_stack void fake_vmewrite8(struct fake_driver *bridge,
616 					      u8 *buf, unsigned long long addr,
617 					      u32 aspace, u32 cycle)
618 {
619 	int i;
620 	unsigned long long start, end, offset;
621 	u8 *loc;
622 
623 	for (i = 0; i < FAKE_MAX_SLAVE; i++) {
624 		if (aspace != bridge->slaves[i].aspace)
625 			continue;
626 
627 		if (cycle != bridge->slaves[i].cycle)
628 			continue;
629 
630 		start = bridge->slaves[i].vme_base;
631 		end = bridge->slaves[i].vme_base + bridge->slaves[i].size;
632 
633 		if ((addr >= start) && (addr < end)) {
634 			offset = addr - bridge->slaves[i].vme_base;
635 			loc = (u8 *)((void *)bridge->slaves[i].buf_base + offset);
636 			*loc = *buf;
637 
638 			break;
639 		}
640 	}
641 
642 	fake_lm_check(bridge, addr, aspace, cycle);
643 
644 }
645 
646 static noinline_for_stack void fake_vmewrite16(struct fake_driver *bridge,
647 					       u16 *buf, unsigned long long addr,
648 					       u32 aspace, u32 cycle)
649 {
650 	int i;
651 	unsigned long long start, end, offset;
652 	u16 *loc;
653 
654 	for (i = 0; i < FAKE_MAX_SLAVE; i++) {
655 		if (aspace != bridge->slaves[i].aspace)
656 			continue;
657 
658 		if (cycle != bridge->slaves[i].cycle)
659 			continue;
660 
661 		start = bridge->slaves[i].vme_base;
662 		end = bridge->slaves[i].vme_base + bridge->slaves[i].size;
663 
664 		if ((addr >= start) && ((addr + 1) < end)) {
665 			offset = addr - bridge->slaves[i].vme_base;
666 			loc = (u16 *)((void *)bridge->slaves[i].buf_base + offset);
667 			*loc = *buf;
668 
669 			break;
670 		}
671 	}
672 
673 	fake_lm_check(bridge, addr, aspace, cycle);
674 
675 }
676 
677 static noinline_for_stack void fake_vmewrite32(struct fake_driver *bridge,
678 					       u32 *buf, unsigned long long addr,
679 					       u32 aspace, u32 cycle)
680 {
681 	int i;
682 	unsigned long long start, end, offset;
683 	u32 *loc;
684 
685 	for (i = 0; i < FAKE_MAX_SLAVE; i++) {
686 		if (aspace != bridge->slaves[i].aspace)
687 			continue;
688 
689 		if (cycle != bridge->slaves[i].cycle)
690 			continue;
691 
692 		start = bridge->slaves[i].vme_base;
693 		end = bridge->slaves[i].vme_base + bridge->slaves[i].size;
694 
695 		if ((addr >= start) && ((addr + 3) < end)) {
696 			offset = addr - bridge->slaves[i].vme_base;
697 			loc = (u32 *)((void *)bridge->slaves[i].buf_base + offset);
698 			*loc = *buf;
699 
700 			break;
701 		}
702 	}
703 
704 	fake_lm_check(bridge, addr, aspace, cycle);
705 
706 }
707 
708 static ssize_t fake_master_write(struct vme_master_resource *image, void *buf,
709 		size_t count, loff_t offset)
710 {
711 	int retval = 0;
712 	u32 aspace, cycle, dwidth;
713 	unsigned long long addr;
714 	int i;
715 	unsigned int done = 0;
716 	unsigned int count32;
717 
718 	struct vme_bridge *fake_bridge;
719 	struct fake_driver *bridge;
720 
721 	fake_bridge = image->parent;
722 
723 	bridge = fake_bridge->driver_priv;
724 
725 	i = image->number;
726 
727 	addr = bridge->masters[i].vme_base + offset;
728 	aspace = bridge->masters[i].aspace;
729 	cycle = bridge->masters[i].cycle;
730 	dwidth = bridge->masters[i].dwidth;
731 
732 	spin_lock(&image->lock);
733 
734 	/* Here we apply for the same strategy we do in master_read
735 	 * function in order to assure the correct cycles.
736 	 */
737 	if (addr & 0x1) {
738 		fake_vmewrite8(bridge, (u8 *)buf, addr, aspace, cycle);
739 		done += 1;
740 		if (done == count)
741 			goto out;
742 	}
743 
744 	if ((dwidth == VME_D16) || (dwidth == VME_D32)) {
745 		if ((addr + done) & 0x2) {
746 			if ((count - done) < 2) {
747 				fake_vmewrite8(bridge, (u8 *)(buf + done),
748 						addr + done, aspace, cycle);
749 				done += 1;
750 				goto out;
751 			} else {
752 				fake_vmewrite16(bridge, (u16 *)(buf + done),
753 						addr + done, aspace, cycle);
754 				done += 2;
755 			}
756 		}
757 	}
758 
759 	if (dwidth == VME_D32) {
760 		count32 = (count - done) & ~0x3;
761 		while (done < count32) {
762 			fake_vmewrite32(bridge, (u32 *)(buf + done),
763 					addr + done, aspace, cycle);
764 			done += 4;
765 		}
766 	} else if (dwidth == VME_D16) {
767 		count32 = (count - done) & ~0x3;
768 		while (done < count32) {
769 			fake_vmewrite16(bridge, (u16 *)(buf + done),
770 					addr + done, aspace, cycle);
771 			done += 2;
772 		}
773 	} else if (dwidth == VME_D8) {
774 		count32 = (count - done);
775 		while (done < count32) {
776 			fake_vmewrite8(bridge, (u8 *)(buf + done), addr + done,
777 					aspace, cycle);
778 			done += 1;
779 		}
780 
781 	}
782 
783 	if ((dwidth == VME_D16) || (dwidth == VME_D32)) {
784 		if ((count - done) & 0x2) {
785 			fake_vmewrite16(bridge, (u16 *)(buf + done),
786 					addr + done, aspace, cycle);
787 			done += 2;
788 		}
789 	}
790 
791 	if ((count - done) & 0x1) {
792 		fake_vmewrite8(bridge, (u8 *)(buf + done), addr + done, aspace,
793 				cycle);
794 		done += 1;
795 	}
796 
797 out:
798 	retval = count;
799 
800 	spin_unlock(&image->lock);
801 
802 	return retval;
803 }
804 
805 /*
806  * Perform an RMW cycle on the VME bus.
807  *
808  * Requires a previously configured master window, returns final value.
809  */
810 static unsigned int fake_master_rmw(struct vme_master_resource *image,
811 		unsigned int mask, unsigned int compare, unsigned int swap,
812 		loff_t offset)
813 {
814 	u32 tmp, base;
815 	u32 aspace, cycle;
816 	int i;
817 	struct fake_driver *bridge;
818 
819 	bridge = image->parent->driver_priv;
820 
821 	/* Find the PCI address that maps to the desired VME address */
822 	i = image->number;
823 
824 	base = bridge->masters[i].vme_base;
825 	aspace = bridge->masters[i].aspace;
826 	cycle = bridge->masters[i].cycle;
827 
828 	/* Lock image */
829 	spin_lock(&image->lock);
830 
831 	/* Read existing value */
832 	tmp = fake_vmeread32(bridge, base + offset, aspace, cycle);
833 
834 	/* Perform check */
835 	if ((tmp && mask) == (compare && mask)) {
836 		tmp = tmp | (mask | swap);
837 		tmp = tmp & (~mask | swap);
838 
839 		/* Write back */
840 		fake_vmewrite32(bridge, &tmp, base + offset, aspace, cycle);
841 	}
842 
843 	/* Unlock image */
844 	spin_unlock(&image->lock);
845 
846 	return tmp;
847 }
848 
849 /*
850  * All 4 location monitors reside at the same base - this is therefore a
851  * system wide configuration.
852  *
853  * This does not enable the LM monitor - that should be done when the first
854  * callback is attached and disabled when the last callback is removed.
855  */
856 static int fake_lm_set(struct vme_lm_resource *lm, unsigned long long lm_base,
857 		u32 aspace, u32 cycle)
858 {
859 	int i;
860 	struct vme_bridge *fake_bridge;
861 	struct fake_driver *bridge;
862 
863 	fake_bridge = lm->parent;
864 
865 	bridge = fake_bridge->driver_priv;
866 
867 	mutex_lock(&lm->mtx);
868 
869 	/* If we already have a callback attached, we can't move it! */
870 	for (i = 0; i < lm->monitors; i++) {
871 		if (bridge->lm_callback[i]) {
872 			mutex_unlock(&lm->mtx);
873 			pr_err("Location monitor callback attached, can't reset\n");
874 			return -EBUSY;
875 		}
876 	}
877 
878 	switch (aspace) {
879 	case VME_A16:
880 	case VME_A24:
881 	case VME_A32:
882 	case VME_A64:
883 		break;
884 	default:
885 		mutex_unlock(&lm->mtx);
886 		pr_err("Invalid address space\n");
887 		return -EINVAL;
888 	}
889 
890 	bridge->lm_base = lm_base;
891 	bridge->lm_aspace = aspace;
892 	bridge->lm_cycle = cycle;
893 
894 	mutex_unlock(&lm->mtx);
895 
896 	return 0;
897 }
898 
899 /* Get configuration of the callback monitor and return whether it is enabled
900  * or disabled.
901  */
902 static int fake_lm_get(struct vme_lm_resource *lm,
903 		unsigned long long *lm_base, u32 *aspace, u32 *cycle)
904 {
905 	struct fake_driver *bridge;
906 
907 	bridge = lm->parent->driver_priv;
908 
909 	mutex_lock(&lm->mtx);
910 
911 	*lm_base = bridge->lm_base;
912 	*aspace = bridge->lm_aspace;
913 	*cycle = bridge->lm_cycle;
914 
915 	mutex_unlock(&lm->mtx);
916 
917 	return bridge->lm_enabled;
918 }
919 
920 /*
921  * Attach a callback to a specific location monitor.
922  *
923  * Callback will be passed the monitor triggered.
924  */
925 static int fake_lm_attach(struct vme_lm_resource *lm, int monitor,
926 		void (*callback)(void *), void *data)
927 {
928 	struct vme_bridge *fake_bridge;
929 	struct fake_driver *bridge;
930 
931 	fake_bridge = lm->parent;
932 
933 	bridge = fake_bridge->driver_priv;
934 
935 	mutex_lock(&lm->mtx);
936 
937 	/* Ensure that the location monitor is configured - need PGM or DATA */
938 	if (bridge->lm_cycle == 0) {
939 		mutex_unlock(&lm->mtx);
940 		pr_err("Location monitor not properly configured\n");
941 		return -EINVAL;
942 	}
943 
944 	/* Check that a callback isn't already attached */
945 	if (bridge->lm_callback[monitor]) {
946 		mutex_unlock(&lm->mtx);
947 		pr_err("Existing callback attached\n");
948 		return -EBUSY;
949 	}
950 
951 	/* Attach callback */
952 	bridge->lm_callback[monitor] = callback;
953 	bridge->lm_data[monitor] = data;
954 
955 	/* Ensure that global Location Monitor Enable set */
956 	bridge->lm_enabled = 1;
957 
958 	mutex_unlock(&lm->mtx);
959 
960 	return 0;
961 }
962 
963 /*
964  * Detach a callback function forn a specific location monitor.
965  */
966 static int fake_lm_detach(struct vme_lm_resource *lm, int monitor)
967 {
968 	u32 tmp;
969 	int i;
970 	struct fake_driver *bridge;
971 
972 	bridge = lm->parent->driver_priv;
973 
974 	mutex_lock(&lm->mtx);
975 
976 	/* Detach callback */
977 	bridge->lm_callback[monitor] = NULL;
978 	bridge->lm_data[monitor] = NULL;
979 
980 	/* If all location monitors disabled, disable global Location Monitor */
981 	tmp = 0;
982 	for (i = 0; i < lm->monitors; i++) {
983 		if (bridge->lm_callback[i])
984 			tmp = 1;
985 	}
986 
987 	if (tmp == 0)
988 		bridge->lm_enabled = 0;
989 
990 	mutex_unlock(&lm->mtx);
991 
992 	return 0;
993 }
994 
995 /*
996  * Determine Geographical Addressing
997  */
998 static int fake_slot_get(struct vme_bridge *fake_bridge)
999 {
1000 	return geoid;
1001 }
1002 
1003 static void *fake_alloc_consistent(struct device *parent, size_t size,
1004 		dma_addr_t *dma)
1005 {
1006 	void *alloc = kmalloc(size, GFP_KERNEL);
1007 
1008 	if (alloc)
1009 		*dma = fake_ptr_to_pci(alloc);
1010 
1011 	return alloc;
1012 }
1013 
1014 static void fake_free_consistent(struct device *parent, size_t size,
1015 		void *vaddr, dma_addr_t dma)
1016 {
1017 	kfree(vaddr);
1018 /*
1019 	dma_free_coherent(parent, size, vaddr, dma);
1020 */
1021 }
1022 
1023 /*
1024  * Configure CR/CSR space
1025  *
1026  * Access to the CR/CSR can be configured at power-up. The location of the
1027  * CR/CSR registers in the CR/CSR address space is determined by the boards
1028  * Geographic address.
1029  *
1030  * Each board has a 512kB window, with the highest 4kB being used for the
1031  * boards registers, this means there is a fix length 508kB window which must
1032  * be mapped onto PCI memory.
1033  */
1034 static int fake_crcsr_init(struct vme_bridge *fake_bridge)
1035 {
1036 	u32 vstat;
1037 	struct fake_driver *bridge;
1038 
1039 	bridge = fake_bridge->driver_priv;
1040 
1041 	/* Allocate mem for CR/CSR image */
1042 	bridge->crcsr_kernel = kzalloc(VME_CRCSR_BUF_SIZE, GFP_KERNEL);
1043 	bridge->crcsr_bus = fake_ptr_to_pci(bridge->crcsr_kernel);
1044 	if (!bridge->crcsr_kernel)
1045 		return -ENOMEM;
1046 
1047 	vstat = fake_slot_get(fake_bridge);
1048 
1049 	pr_info("CR/CSR Offset: %d\n", vstat);
1050 
1051 	return 0;
1052 }
1053 
1054 static void fake_crcsr_exit(struct vme_bridge *fake_bridge)
1055 {
1056 	struct fake_driver *bridge;
1057 
1058 	bridge = fake_bridge->driver_priv;
1059 
1060 	kfree(bridge->crcsr_kernel);
1061 }
1062 
1063 
1064 static int __init fake_init(void)
1065 {
1066 	int retval, i;
1067 	struct list_head *pos = NULL, *n;
1068 	struct vme_bridge *fake_bridge;
1069 	struct fake_driver *fake_device;
1070 	struct vme_master_resource *master_image;
1071 	struct vme_slave_resource *slave_image;
1072 	struct vme_lm_resource *lm;
1073 
1074 	/* We need a fake parent device */
1075 	vme_root = __root_device_register("vme", THIS_MODULE);
1076 
1077 	/* If we want to support more than one bridge at some point, we need to
1078 	 * dynamically allocate this so we get one per device.
1079 	 */
1080 	fake_bridge = kzalloc(sizeof(*fake_bridge), GFP_KERNEL);
1081 	if (!fake_bridge) {
1082 		retval = -ENOMEM;
1083 		goto err_struct;
1084 	}
1085 
1086 	fake_device = kzalloc(sizeof(*fake_device), GFP_KERNEL);
1087 	if (!fake_device) {
1088 		retval = -ENOMEM;
1089 		goto err_driver;
1090 	}
1091 
1092 	fake_bridge->driver_priv = fake_device;
1093 
1094 	fake_bridge->parent = vme_root;
1095 
1096 	fake_device->parent = fake_bridge;
1097 
1098 	/* Initialize wait queues & mutual exclusion flags */
1099 	mutex_init(&fake_device->vme_int);
1100 	mutex_init(&fake_bridge->irq_mtx);
1101 	tasklet_init(&fake_device->int_tasklet, fake_VIRQ_tasklet,
1102 			(unsigned long) fake_bridge);
1103 
1104 	strcpy(fake_bridge->name, driver_name);
1105 
1106 	/* Add master windows to list */
1107 	INIT_LIST_HEAD(&fake_bridge->master_resources);
1108 	for (i = 0; i < FAKE_MAX_MASTER; i++) {
1109 		master_image = kmalloc(sizeof(*master_image), GFP_KERNEL);
1110 		if (!master_image) {
1111 			retval = -ENOMEM;
1112 			goto err_master;
1113 		}
1114 		master_image->parent = fake_bridge;
1115 		spin_lock_init(&master_image->lock);
1116 		master_image->locked = 0;
1117 		master_image->number = i;
1118 		master_image->address_attr = VME_A16 | VME_A24 | VME_A32 |
1119 			VME_A64;
1120 		master_image->cycle_attr = VME_SCT | VME_BLT | VME_MBLT |
1121 			VME_2eVME | VME_2eSST | VME_2eSSTB | VME_2eSST160 |
1122 			VME_2eSST267 | VME_2eSST320 | VME_SUPER | VME_USER |
1123 			VME_PROG | VME_DATA;
1124 		master_image->width_attr = VME_D16 | VME_D32;
1125 		memset(&master_image->bus_resource, 0,
1126 				sizeof(struct resource));
1127 		master_image->kern_base  = NULL;
1128 		list_add_tail(&master_image->list,
1129 				&fake_bridge->master_resources);
1130 	}
1131 
1132 	/* Add slave windows to list */
1133 	INIT_LIST_HEAD(&fake_bridge->slave_resources);
1134 	for (i = 0; i < FAKE_MAX_SLAVE; i++) {
1135 		slave_image = kmalloc(sizeof(*slave_image), GFP_KERNEL);
1136 		if (!slave_image) {
1137 			retval = -ENOMEM;
1138 			goto err_slave;
1139 		}
1140 		slave_image->parent = fake_bridge;
1141 		mutex_init(&slave_image->mtx);
1142 		slave_image->locked = 0;
1143 		slave_image->number = i;
1144 		slave_image->address_attr = VME_A16 | VME_A24 | VME_A32 |
1145 			VME_A64 | VME_CRCSR | VME_USER1 | VME_USER2 |
1146 			VME_USER3 | VME_USER4;
1147 		slave_image->cycle_attr = VME_SCT | VME_BLT | VME_MBLT |
1148 			VME_2eVME | VME_2eSST | VME_2eSSTB | VME_2eSST160 |
1149 			VME_2eSST267 | VME_2eSST320 | VME_SUPER | VME_USER |
1150 			VME_PROG | VME_DATA;
1151 		list_add_tail(&slave_image->list,
1152 				&fake_bridge->slave_resources);
1153 	}
1154 
1155 	/* Add location monitor to list */
1156 	INIT_LIST_HEAD(&fake_bridge->lm_resources);
1157 	lm = kmalloc(sizeof(*lm), GFP_KERNEL);
1158 	if (!lm) {
1159 		retval = -ENOMEM;
1160 		goto err_lm;
1161 	}
1162 	lm->parent = fake_bridge;
1163 	mutex_init(&lm->mtx);
1164 	lm->locked = 0;
1165 	lm->number = 1;
1166 	lm->monitors = 4;
1167 	list_add_tail(&lm->list, &fake_bridge->lm_resources);
1168 
1169 	fake_bridge->slave_get = fake_slave_get;
1170 	fake_bridge->slave_set = fake_slave_set;
1171 	fake_bridge->master_get = fake_master_get;
1172 	fake_bridge->master_set = fake_master_set;
1173 	fake_bridge->master_read = fake_master_read;
1174 	fake_bridge->master_write = fake_master_write;
1175 	fake_bridge->master_rmw = fake_master_rmw;
1176 	fake_bridge->irq_set = fake_irq_set;
1177 	fake_bridge->irq_generate = fake_irq_generate;
1178 	fake_bridge->lm_set = fake_lm_set;
1179 	fake_bridge->lm_get = fake_lm_get;
1180 	fake_bridge->lm_attach = fake_lm_attach;
1181 	fake_bridge->lm_detach = fake_lm_detach;
1182 	fake_bridge->slot_get = fake_slot_get;
1183 	fake_bridge->alloc_consistent = fake_alloc_consistent;
1184 	fake_bridge->free_consistent = fake_free_consistent;
1185 
1186 	pr_info("Board is%s the VME system controller\n",
1187 			(geoid == 1) ? "" : " not");
1188 
1189 	pr_info("VME geographical address is set to %d\n", geoid);
1190 
1191 	retval = fake_crcsr_init(fake_bridge);
1192 	if (retval) {
1193 		pr_err("CR/CSR configuration failed.\n");
1194 		goto err_crcsr;
1195 	}
1196 
1197 	retval = vme_register_bridge(fake_bridge);
1198 	if (retval != 0) {
1199 		pr_err("Chip Registration failed.\n");
1200 		goto err_reg;
1201 	}
1202 
1203 	exit_pointer = fake_bridge;
1204 
1205 	return 0;
1206 
1207 err_reg:
1208 	fake_crcsr_exit(fake_bridge);
1209 err_crcsr:
1210 err_lm:
1211 	/* resources are stored in link list */
1212 	list_for_each_safe(pos, n, &fake_bridge->lm_resources) {
1213 		lm = list_entry(pos, struct vme_lm_resource, list);
1214 		list_del(pos);
1215 		kfree(lm);
1216 	}
1217 err_slave:
1218 	/* resources are stored in link list */
1219 	list_for_each_safe(pos, n, &fake_bridge->slave_resources) {
1220 		slave_image = list_entry(pos, struct vme_slave_resource, list);
1221 		list_del(pos);
1222 		kfree(slave_image);
1223 	}
1224 err_master:
1225 	/* resources are stored in link list */
1226 	list_for_each_safe(pos, n, &fake_bridge->master_resources) {
1227 		master_image = list_entry(pos, struct vme_master_resource,
1228 				list);
1229 		list_del(pos);
1230 		kfree(master_image);
1231 	}
1232 
1233 	kfree(fake_device);
1234 err_driver:
1235 	kfree(fake_bridge);
1236 err_struct:
1237 	return retval;
1238 
1239 }
1240 
1241 
1242 static void __exit fake_exit(void)
1243 {
1244 	struct list_head *pos = NULL;
1245 	struct list_head *tmplist;
1246 	struct vme_master_resource *master_image;
1247 	struct vme_slave_resource *slave_image;
1248 	int i;
1249 	struct vme_bridge *fake_bridge;
1250 	struct fake_driver *bridge;
1251 
1252 	fake_bridge = exit_pointer;
1253 
1254 	bridge = fake_bridge->driver_priv;
1255 
1256 	pr_debug("Driver is being unloaded.\n");
1257 
1258 	/*
1259 	 *  Shutdown all inbound and outbound windows.
1260 	 */
1261 	for (i = 0; i < FAKE_MAX_MASTER; i++)
1262 		bridge->masters[i].enabled = 0;
1263 
1264 	for (i = 0; i < FAKE_MAX_SLAVE; i++)
1265 		bridge->slaves[i].enabled = 0;
1266 
1267 	/*
1268 	 *  Shutdown Location monitor.
1269 	 */
1270 	bridge->lm_enabled = 0;
1271 
1272 	vme_unregister_bridge(fake_bridge);
1273 
1274 	fake_crcsr_exit(fake_bridge);
1275 	/* resources are stored in link list */
1276 	list_for_each_safe(pos, tmplist, &fake_bridge->slave_resources) {
1277 		slave_image = list_entry(pos, struct vme_slave_resource, list);
1278 		list_del(pos);
1279 		kfree(slave_image);
1280 	}
1281 
1282 	/* resources are stored in link list */
1283 	list_for_each_safe(pos, tmplist, &fake_bridge->master_resources) {
1284 		master_image = list_entry(pos, struct vme_master_resource,
1285 				list);
1286 		list_del(pos);
1287 		kfree(master_image);
1288 	}
1289 
1290 	kfree(fake_bridge->driver_priv);
1291 
1292 	kfree(fake_bridge);
1293 
1294 	root_device_unregister(vme_root);
1295 }
1296 
1297 
1298 MODULE_PARM_DESC(geoid, "Set geographical addressing");
1299 module_param(geoid, int, 0);
1300 
1301 MODULE_DESCRIPTION("Fake VME bridge driver");
1302 MODULE_LICENSE("GPL");
1303 
1304 module_init(fake_init);
1305 module_exit(fake_exit);
1306