aboutsummaryrefslogtreecommitdiff
path: root/arch/powerpc/platforms/ps3/mm.c
blob: 42354de3f557e41e16202580181ab6dc160c79a8 (plain)
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
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
/*
 *  PS3 address space management.
 *
 *  Copyright (C) 2006 Sony Computer Entertainment Inc.
 *  Copyright 2006 Sony Corp.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; version 2 of the License.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/memory_hotplug.h>

#include <asm/firmware.h>
#include <asm/lmb.h>
#include <asm/udbg.h>
#include <asm/lv1call.h>

#include "platform.h"

#if defined(DEBUG)
#define DBG(fmt...) udbg_printf(fmt)
#else
#define DBG(fmt...) do{if(0)printk(fmt);}while(0)
#endif

enum {
#if defined(CONFIG_PS3_USE_LPAR_ADDR)
	USE_LPAR_ADDR = 1,
#else
	USE_LPAR_ADDR = 0,
#endif
#if defined(CONFIG_PS3_DYNAMIC_DMA)
	USE_DYNAMIC_DMA = 1,
#else
	USE_DYNAMIC_DMA = 0,
#endif
};

enum {
	PAGE_SHIFT_4K = 12U,
	PAGE_SHIFT_64K = 16U,
	PAGE_SHIFT_16M = 24U,
};

static unsigned long make_page_sizes(unsigned long a, unsigned long b)
{
	return (a << 56) | (b << 48);
}

enum {
	ALLOCATE_MEMORY_TRY_ALT_UNIT = 0X04,
	ALLOCATE_MEMORY_ADDR_ZERO = 0X08,
};

/* valid htab sizes are {18,19,20} = 256K, 512K, 1M */

enum {
	HTAB_SIZE_MAX = 20U, /* HV limit of 1MB */
	HTAB_SIZE_MIN = 18U, /* CPU limit of 256KB */
};

/*============================================================================*/
/* virtual address space routines                                             */
/*============================================================================*/

/**
 * struct mem_region - memory region structure
 * @base: base address
 * @size: size in bytes
 * @offset: difference between base and rm.size
 */

struct mem_region {
	unsigned long base;
	unsigned long size;
	unsigned long offset;
};

/**
 * struct map - address space state variables holder
 * @total: total memory available as reported by HV
 * @vas_id - HV virtual address space id
 * @htab_size: htab size in bytes
 *
 * The HV virtual address space (vas) allows for hotplug memory regions.
 * Memory regions can be created and destroyed in the vas at runtime.
 * @rm: real mode (bootmem) region
 * @r1: hotplug memory region(s)
 *
 * ps3 addresses
 * virt_addr: a cpu 'translated' effective address
 * phys_addr: an address in what Linux thinks is the physical address space
 * lpar_addr: an address in the HV virtual address space
 * bus_addr: an io controller 'translated' address on a device bus
 */

struct map {
	unsigned long total;
	unsigned long vas_id;
	unsigned long htab_size;
	struct mem_region rm;
	struct mem_region r1;
};

#define debug_dump_map(x) _debug_dump_map(x, __func__, __LINE__)
static void _debug_dump_map(const struct map* m, const char* func, int line)
{
	DBG("%s:%d: map.total     = %lxh\n", func, line, m->total);
	DBG("%s:%d: map.rm.size   = %lxh\n", func, line, m->rm.size);
	DBG("%s:%d: map.vas_id    = %lu\n", func, line, m->vas_id);
	DBG("%s:%d: map.htab_size = %lxh\n", func, line, m->htab_size);
	DBG("%s:%d: map.r1.base   = %lxh\n", func, line, m->r1.base);
	DBG("%s:%d: map.r1.offset = %lxh\n", func, line, m->r1.offset);
	DBG("%s:%d: map.r1.size   = %lxh\n", func, line, m->r1.size);
}

static struct map map;

/**
 * ps3_mm_phys_to_lpar - translate a linux physical address to lpar address
 * @phys_addr: linux physical address
 */

unsigned long ps3_mm_phys_to_lpar(unsigned long phys_addr)
{
	BUG_ON(is_kernel_addr(phys_addr));
	if (USE_LPAR_ADDR)
		return phys_addr;
	else
		return (phys_addr < map.rm.size || phys_addr >= map.total)
			? phys_addr : phys_addr + map.r1.offset;
}

EXPORT_SYMBOL(ps3_mm_phys_to_lpar);

/**
 * ps3_mm_vas_create - create the virtual address space
 */

void __init ps3_mm_vas_create(unsigned long* htab_size)
{
	int result;
	unsigned long start_address;
	unsigned long size;
	unsigned long access_right;
	unsigned long max_page_size;
	unsigned long flags;

	result = lv1_query_logical_partition_address_region_info(0,
		&start_address, &size, &access_right, &max_page_size,
		&flags);

	if (result) {
		DBG("%s:%d: lv1_query_logical_partition_address_region_info "
			"failed: %s\n", __func__, __LINE__,
			ps3_result(result));
		goto fail;
	}

	if (max_page_size < PAGE_SHIFT_16M) {
		DBG("%s:%d: bad max_page_size %lxh\n", __func__, __LINE__,
			max_page_size);
		goto fail;
	}

	BUILD_BUG_ON(CONFIG_PS3_HTAB_SIZE > HTAB_SIZE_MAX);
	BUILD_BUG_ON(CONFIG_PS3_HTAB_SIZE < HTAB_SIZE_MIN);

	result = lv1_construct_virtual_address_space(CONFIG_PS3_HTAB_SIZE,
			2, make_page_sizes(PAGE_SHIFT_16M, PAGE_SHIFT_64K),
			&map.vas_id, &map.htab_size);

	if (result) {
		DBG("%s:%d: lv1_construct_virtual_address_space failed: %s\n",
			__func__, __LINE__, ps3_result(result));
		goto fail;
	}

	result = lv1_select_virtual_address_space(map.vas_id);

	if (result) {
		DBG("%s:%d: lv1_select_virtual_address_space failed: %s\n",
			__func__, __LINE__, ps3_result(result));
		goto fail;
	}

	*htab_size = map.htab_size;

	debug_dump_map(&map);

	return;

fail:
	panic("ps3_mm_vas_create failed");
}

/**
 * ps3_mm_vas_destroy -
 */

void ps3_mm_vas_destroy(void)
{
	if (map.vas_id) {
		lv1_select_virtual_address_space(0);
		lv1_destruct_virtual_address_space(map.vas_id);
		map.vas_id = 0;
	}
}

/*============================================================================*/
/* memory hotplug routines                                                    */
/*============================================================================*/

/**
 * ps3_mm_region_create - create a memory region in the vas
 * @r: pointer to a struct mem_region to accept initialized values
 * @size: requested region size
 *
 * This implementation creates the region with the vas large page size.
 * @size is rounded down to a multiple of the vas large page size.
 */

int ps3_mm_region_create(struct mem_region *r, unsigned long size)
{
	int result;
	unsigned long muid;

	r->size = _ALIGN_DOWN(size, 1 << PAGE_SHIFT_16M);

	DBG("%s:%d requested  %lxh\n", __func__, __LINE__, size);
	DBG("%s:%d actual     %lxh\n", __func__, __LINE__, r->size);
	DBG("%s:%d difference %lxh (%luMB)\n", __func__, __LINE__,
		(unsigned long)(size - r->size),
		(size - r->size) / 1024 / 1024);

	if (r->size == 0) {
		DBG("%s:%d: size == 0\n", __func__, __LINE__);
		result = -1;
		goto zero_region;
	}

	result = lv1_allocate_memory(r->size, PAGE_SHIFT_16M, 0,
		ALLOCATE_MEMORY_TRY_ALT_UNIT, &r->base, &muid);

	if (result || r->base < map.rm.size) {
		DBG("%s:%d: lv1_allocate_memory failed: %s\n",
			__func__, __LINE__, ps3_result(result));
		goto zero_region;
	}

	r->offset = r->base - map.rm.size;
	return result;

zero_region:
	r->size = r->base = r->offset = 0;
	return result;
}

/**
 * ps3_mm_region_destroy - destroy a memory region
 * @r: pointer to struct mem_region
 */

void ps3_mm_region_destroy(struct mem_region *r)
{
	if (r->base) {
		lv1_release_memory(r->base);
		r->size = r->base = r->offset = 0;
		map.total = map.rm.size;
	}
}

/**
 * ps3_mm_add_memory - hot add memory
 */

static int __init ps3_mm_add_memory(void)
{
	int result;
	unsigned long start_addr;
	unsigned long start_pfn;
	unsigned long nr_pages;

	if (!firmware_has_feature(FW_FEATURE_PS3_LV1))
		return 0;

	BUG_ON(!mem_init_done);

	start_addr = USE_LPAR_ADDR ? map.r1.base : map.rm.size;
	start_pfn = start_addr >> PAGE_SHIFT;
	nr_pages = (map.r1.size + PAGE_SIZE - 1) >> PAGE_SHIFT;

	DBG("%s:%d: start_addr %lxh, start_pfn %lxh, nr_pages %lxh\n",
		__func__, __LINE__, start_addr, start_pfn, nr_pages);

	result = add_memory(0, start_addr, map.r1.size);

	if (result) {
		DBG("%s:%d: add_memory failed: (%d)\n",
			__func__, __LINE__, result);
		return result;
	}

	result = online_pages(start_pfn, nr_pages);

	if (result)
		DBG("%s:%d: online_pages failed: (%d)\n",
			__func__, __LINE__, result);

	return result;
}

core_initcall(ps3_mm_add_memory);

/*============================================================================*/
/* dma routines                                                               */
/*============================================================================*/

/**
 * dma_lpar_to_bus - Translate an lpar address to ioc mapped bus address.
 * @r: pointer to dma region structure
 * @lpar_addr: HV lpar address
 */

static unsigned long dma_lpar_to_bus(struct ps3_dma_region *r,
	unsigned long lpar_addr)
{
	BUG_ON(lpar_addr >= map.r1.base + map.r1.size);
	return r->bus_addr + (lpar_addr <= map.rm.size ? lpar_addr
		: lpar_addr - map.r1.offset);
}

#define dma_dump_region(_a) _dma_dump_region(_a, __func__, __LINE__)
static void _dma_dump_region(const struct ps3_dma_region *r, const char* func,
	int line)
{
	DBG("%s:%d: dev        %u:%u\n", func, line, r->did.bus_id,
		r->did.dev_id);
	DBG("%s:%d: page_size  %u\n", func, line, r->page_size);
	DBG("%s:%d: bus_addr   %lxh\n", func, line, r->bus_addr);
	DBG("%s:%d: len        %lxh\n", func, line, r->len);
}

/**
 * dma_chunk - A chunk of dma pages mapped by the io controller.
 * @region - The dma region that owns this chunk.
 * @lpar_addr: Starting lpar address of the area to map.
 * @bus_addr: Starting ioc bus address of the area to map.
 * @len: Length in bytes of the area to map.
 * @link: A struct list_head used with struct ps3_dma_region.chunk_list, the
 * list of all chuncks owned by the region.
 *
 * This implementation uses a very simple dma page manager
 * based on the dma_chunk structure.  This scheme assumes
 * that all drivers use very well behaved dma ops.
 */

struct dma_chunk {
	struct ps3_dma_region *region;
	unsigned long lpar_addr;
	unsigned long bus_addr;
	unsigned long len;
	struct list_head link;
	unsigned int usage_count;
};

#define dma_dump_chunk(_a) _dma_dump_chunk(_a, __func__, __LINE__)
static void _dma_dump_chunk (const struct dma_chunk* c, const char* func,
	int line)
{
	DBG("%s:%d: r.dev        %u:%u\n", func, line,
		c->region->did.bus_id, c->region->did.dev_id);
	DBG("%s:%d: r.bus_addr   %lxh\n", func, line, c->region->bus_addr);
	DBG("%s:%d: r.page_size  %u\n", func, line, c->region->page_size);
	DBG("%s:%d: r.len        %lxh\n", func, line, c->region->len);
	DBG("%s:%d: c.lpar_addr  %lxh\n", func, line, c->lpar_addr);
	DBG("%s:%d: c.bus_addr   %lxh\n", func, line, c->bus_addr);
	DBG("%s:%d: c.len        %lxh\n", func, line, c->len);
}

static struct dma_chunk * dma_find_chunk(struct ps3_dma_region *r,
	unsigned long bus_addr, unsigned long len)
{
	struct dma_chunk *c;
	unsigned long aligned_bus = _ALIGN_DOWN(bus_addr, 1 << r->page_size);
	unsigned long aligned_len = _ALIGN_UP(len, 1 << r->page_size);

	list_for_each_entry(c, &r->chunk_list.head, link) {
		/* intersection */
		if (aligned_bus >= c->bus_addr
			&& aligned_bus < c->bus_addr + c->len
			&& aligned_bus + aligned_len <= c->bus_addr + c->len) {
			return c;
		}
		/* below */
		if (aligned_bus + aligned_len <= c->bus_addr) {
			continue;
		}
		/* above */
		if (aligned_bus >= c->bus_addr + c->len) {
			continue;
		}

		/* we don't handle the multi-chunk case for now */

		dma_dump_chunk(c);
		BUG();
	}
	return NULL;
}

static int dma_free_chunk(struct dma_chunk *c)
{
	int result = 0;

	if (c->bus_addr) {
		result = lv1_unmap_device_dma_region(c->region->did.bus_id,
			c->region->did.dev_id, c->bus_addr, c->len);
		BUG_ON(result);
	}

	kfree(c);
	return result;
}

/**
 * dma_map_pages - Maps dma pages into the io controller bus address space.
 * @r: Pointer to a struct ps3_dma_region.
 * @phys_addr: Starting physical address of the area to map.
 * @len: Length in bytes of the area to map.
 * c_out: A pointer to receive an allocated struct dma_chunk for this area.
 *
 * This is the lowest level dma mapping routine, and is the one that will
 * make the HV call to add the pages into the io controller address space.
 */

static int dma_map_pages(struct ps3_dma_region *r, unsigned long phys_addr,
	unsigned long len, struct dma_chunk **c_out)
{
	int result;
	struct dma_chunk *c;

	c = kzalloc(sizeof(struct dma_chunk), GFP_ATOMIC);

	if (!c) {
		result = -ENOMEM;
		goto fail_alloc;
	}

	c->region = r;
	c->lpar_addr = ps3_mm_phys_to_lpar(phys_addr);
	c->bus_addr = dma_lpar_to_bus(r, c->lpar_addr);
	c->len = len;

	result = lv1_map_device_dma_region(c->region->did.bus_id,
		c->region->did.dev_id, c->lpar_addr, c->bus_addr, c->len,
		0xf800000000000000UL);

	if (result) {
		DBG("%s:%d: lv1_map_device_dma_region failed: %s\n",
			__func__, __LINE__, ps3_result(result));
		goto fail_map;
	}

	list_add(&c->link, &r->chunk_list.head);

	*c_out = c;
	return 0;

fail_map:
	kfree(c);
fail_alloc:
	*c_out = NULL;
	DBG(" <- %s:%d\n", __func__, __LINE__);
	return result;
}

/**
 * dma_region_create - Create a device dma region.
 * @r: Pointer to a struct ps3_dma_region.
 *
 * This is the lowest level dma region create routine, and is the one that
 * will make the HV call to create the region.
 */

static int dma_region_create(struct ps3_dma_region* r)
{
	int result;

	r->len = _ALIGN_UP(map.total, 1 << r->page_size);
	INIT_LIST_HEAD(&r->chunk_list.head);
	spin_lock_init(&r->chunk_list.lock);

	result = lv1_allocate_device_dma_region(r->did.bus_id, r->did.dev_id,
		r->len, r->page_size, r->region_type, &r->bus_addr);

	dma_dump_region(r);

	if (result) {
		DBG("%s:%d: lv1_allocate_device_dma_region failed: %s\n",
			__func__, __LINE__, ps3_result(result));
		r->len = r->bus_addr = 0;
	}

	return result;
}

/**
 * dma_region_free - Free a device dma region.
 * @r: Pointer to a struct ps3_dma_region.
 *
 * This is the lowest level dma region free routine, and is the one that
 * will make the HV call to free the region.
 */

static int dma_region_free(struct ps3_dma_region* r)
{
	int result;
	struct dma_chunk *c;
	struct dma_chunk *tmp;

	list_for_each_entry_safe(c, tmp, &r->chunk_list.head, link) {
		list_del(&c->link);
		dma_free_chunk(c);
	}

	result = lv1_free_device_dma_region(r->did.bus_id, r->did.dev_id,
		r->bus_addr);

	if (result)
		DBG("%s:%d: lv1_free_device_dma_region failed: %s\n",
			__func__, __LINE__, ps3_result(result));

	r->len = r->bus_addr = 0;

	return result;
}

/**
 * dma_map_area - Map an area of memory into a device dma region.
 * @r: Pointer to a struct ps3_dma_region.
 * @virt_addr: Starting virtual address of the area to map.
 * @len: Length in bytes of the area to map.
 * @bus_addr: A pointer to return the starting ioc bus address of the area to
 * map.
 *
 * This is the common dma mapping routine.
 */

static int dma_map_area(struct ps3_dma_region *r, unsigned long virt_addr,
	unsigned long len, unsigned long *bus_addr)
{
	int result;
	unsigned long flags;
	struct dma_chunk *c;
	unsigned long phys_addr = is_kernel_addr(virt_addr) ? __pa(virt_addr)
		: virt_addr;

	*bus_addr = dma_lpar_to_bus(r, ps3_mm_phys_to_lpar(phys_addr));

	if (!USE_DYNAMIC_DMA) {
		unsigned long lpar_addr = ps3_mm_phys_to_lpar(phys_addr);
		DBG(" -> %s:%d\n", __func__, __LINE__);
		DBG("%s:%d virt_addr %lxh\n", __func__, __LINE__,
			virt_addr);
		DBG("%s:%d phys_addr %lxh\n", __func__, __LINE__,
			phys_addr);
		DBG("%s:%d lpar_addr %lxh\n", __func__, __LINE__,
			lpar_addr);
		DBG("%s:%d len       %lxh\n", __func__, __LINE__, len);
		DBG("%s:%d bus_addr  %lxh (%lxh)\n", __func__, __LINE__,
		*bus_addr, len);
	}

	spin_lock_irqsave(&r->chunk_list.lock, flags);
	c = dma_find_chunk(r, *bus_addr, len);

	if (c) {
		c->usage_count++;
		spin_unlock_irqrestore(&r->chunk_list.lock, flags);
		return 0;
	}

	result = dma_map_pages(r, _ALIGN_DOWN(phys_addr, 1 << r->page_size),
		_ALIGN_UP(len, 1 << r->page_size), &c);

	if (result) {
		*bus_addr = 0;
		DBG("%s:%d: dma_map_pages failed (%d)\n",
			__func__, __LINE__, result);
		spin_unlock_irqrestore(&r->chunk_list.lock, flags);
		return result;
	}

	c->usage_count = 1;

	spin_unlock_irqrestore(&r->chunk_list.lock, flags);
	return result;
}

/**
 * dma_unmap_area - Unmap an area of memory from a device dma region.
 * @r: Pointer to a struct ps3_dma_region.
 * @bus_addr: The starting ioc bus address of the area to unmap.
 * @len: Length in bytes of the area to unmap.
 *
 * This is the common dma unmap routine.
 */

int dma_unmap_area(struct ps3_dma_region *r, unsigned long bus_addr,
	unsigned long len)
{
	unsigned long flags;
	struct dma_chunk *c;

	spin_lock_irqsave(&r->chunk_list.lock, flags);
	c = dma_find_chunk(r, bus_addr, len);

	if (!c) {
		unsigned long aligned_bus = _ALIGN_DOWN(bus_addr,
			1 << r->page_size);
		unsigned long aligned_len = _ALIGN_UP(len, 1 << r->page_size);
		DBG("%s:%d: not found: bus_addr %lxh\n",
			__func__, __LINE__, bus_addr);
		DBG("%s:%d: not found: len %lxh\n",
			__func__, __LINE__, len);
		DBG("%s:%d: not found: aligned_bus %lxh\n",
			__func__, __LINE__, aligned_bus);
		DBG("%s:%d: not found: aligned_len %lxh\n",
			__func__, __LINE__, aligned_len);
		BUG();
	}

	c->usage_count--;

	if (!c->usage_count) {
		list_del(&c->link);
		dma_free_chunk(c);
	}

	spin_unlock_irqrestore(&r->chunk_list.lock, flags);
	return 0;
}

/**
 * dma_region_create_linear - Setup a linear dma maping for a device.
 * @r: Pointer to a struct ps3_dma_region.
 *
 * This routine creates an HV dma region for the device and maps all available
 * ram into the io controller bus address space.
 */

static int dma_region_create_linear(struct ps3_dma_region *r)
{
	int result;
	unsigned long tmp;

	/* force 16M dma pages for linear mapping */

	if (r->page_size != PS3_DMA_16M) {
		pr_info("%s:%d: forcing 16M pages for linear map\n",
			__func__, __LINE__);
		r->page_size = PS3_DMA_16M;
	}

	result = dma_region_create(r);
	BUG_ON(result);

	result = dma_map_area(r, map.rm.base, map.rm.size, &tmp);
	BUG_ON(result);

	if (USE_LPAR_ADDR)
		result = dma_map_area(r, map.r1.base, map.r1.size,
			&tmp);
	else
		result = dma_map_area(r, map.rm.size, map.r1.size,
			&tmp);

	BUG_ON(result);

	return result;
}

/**
 * dma_region_free_linear - Free a linear dma mapping for a device.
 * @r: Pointer to a struct ps3_dma_region.
 *
 * This routine will unmap all mapped areas and free the HV dma region.
 */

static int dma_region_free_linear(struct ps3_dma_region *r)
{
	int result;

	result = dma_unmap_area(r, dma_lpar_to_bus(r, 0), map.rm.size);
	BUG_ON(result);

	result = dma_unmap_area(r, dma_lpar_to_bus(r, map.r1.base),
		map.r1.size);
	BUG_ON(result);

	result = dma_region_free(r);
	BUG_ON(result);

	return result;
}

/**
 * dma_map_area_linear - Map an area of memory into a device dma region.
 * @r: Pointer to a struct ps3_dma_region.
 * @virt_addr: Starting virtual address of the area to map.
 * @len: Length in bytes of the area to map.
 * @bus_addr: A pointer to return the starting ioc bus address of the area to
 * map.
 *
 * This routine just returns the coresponding bus address.  Actual mapping
 * occurs in dma_region_create_linear().
 */

static int dma_map_area_linear(struct ps3_dma_region *r,
	unsigned long virt_addr, unsigned long len, unsigned long *bus_addr)
{
	unsigned long phys_addr = is_kernel_addr(virt_addr) ? __pa(virt_addr)
		: virt_addr;
	*bus_addr = dma_lpar_to_bus(r, ps3_mm_phys_to_lpar(phys_addr));
	return 0;
}

/**
 * dma_unmap_area_linear - Unmap an area of memory from a device dma region.
 * @r: Pointer to a struct ps3_dma_region.
 * @bus_addr: The starting ioc bus address of the area to unmap.
 * @len: Length in bytes of the area to unmap.
 *
 * This routine does nothing.  Unmapping occurs in dma_region_free_linear().
 */

static int dma_unmap_area_linear(struct ps3_dma_region *r,
	unsigned long bus_addr, unsigned long len)
{
	return 0;
}

int ps3_dma_region_create(struct ps3_dma_region *r)
{
	return (USE_DYNAMIC_DMA)
		? dma_region_create(r)
		: dma_region_create_linear(r);
}

int ps3_dma_region_free(struct ps3_dma_region *r)
{
	return (USE_DYNAMIC_DMA)
		? dma_region_free(r)
		: dma_region_free_linear(r);
}

int ps3_dma_map(struct ps3_dma_region *r, unsigned long virt_addr,
	unsigned long len, unsigned long *bus_addr)
{
	return (USE_DYNAMIC_DMA)
		? dma_map_area(r, virt_addr, len, bus_addr)
		: dma_map_area_linear(r, virt_addr, len, bus_addr);
}

int ps3_dma_unmap(struct ps3_dma_region *r, unsigned long bus_addr,
	unsigned long len)
{
	return (USE_DYNAMIC_DMA) ? dma_unmap_area(r, bus_addr, len)
		: dma_unmap_area_linear(r, bus_addr, len);
}

/*============================================================================*/
/* system startup routines                                                    */
/*============================================================================*/

/**
 * ps3_mm_init - initialize the address space state variables
 */

void __init ps3_mm_init(void)
{
	int result;

	DBG(" -> %s:%d\n", __func__, __LINE__);

	result = ps3_repository_read_mm_info(&map.rm.base, &map.rm.size,
		&map.total);

	if (result)
		panic("ps3_repository_read_mm_info() failed");

	map.rm.offset = map.rm.base;
	map.vas_id = map.htab_size = 0;

	/* this implementation assumes map.rm.base is zero */

	BUG_ON(map.rm.base);
	BUG_ON(!map.rm.size);

	lmb_add(map.rm.base, map.rm.size);
	lmb_analyze();

	/* arrange to do this in ps3_mm_add_memory */
	ps3_mm_region_create(&map.r1, map.total - map.rm.size);

	DBG(" <- %s:%d\n", __func__, __LINE__);
}

/**
 * ps3_mm_shutdown - final cleanup of address space
 */

void ps3_mm_shutdown(void)
{
	ps3_mm_region_destroy(&map.r1);
	map.total = map.rm.size;
}