aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/gpu/drm/i915/i915_gem_stolen.c
blob: 9c6f93ec886b7023b0ce8fa2753bacaaf041aaff (plain) (blame)
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
/*
 * Copyright © 2008-2012 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 *
 * Authors:
 *    Eric Anholt <eric@anholt.net>
 *    Chris Wilson <chris@chris-wilson.co.uk>
 *
 */

#include <drm/drmP.h>
#include <drm/i915_drm.h>
#include "i915_drv.h"

/*
 * The BIOS typically reserves some of the system's memory for the exclusive
 * use of the integrated graphics. This memory is no longer available for
 * use by the OS and so the user finds that his system has less memory
 * available than he put in. We refer to this memory as stolen.
 *
 * The BIOS will allocate its framebuffer from the stolen memory. Our
 * goal is try to reuse that object for our own fbcon which must always
 * be available for panics. Anything else we can reuse the stolen memory
 * for is a boon.
 */

static unsigned long i915_stolen_to_physical(struct drm_device *dev)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	struct resource *r;
	u32 base;

	/* Almost universally we can find the Graphics Base of Stolen Memory
	 * at offset 0x5c in the igfx configuration space. On a few (desktop)
	 * machines this is also mirrored in the bridge device at different
	 * locations, or in the MCHBAR. On gen2, the layout is again slightly
	 * different with the Graphics Segment immediately following Top of
	 * Memory (or Top of Usable DRAM). Note it appears that TOUD is only
	 * reported by 865g, so we just use the top of memory as determined
	 * by the e820 probe.
	 *
	 * XXX However gen2 requires an unavailable symbol.
	 */
	base = 0;
	if (INTEL_INFO(dev)->gen >= 3) {
		/* Read Graphics Base of Stolen Memory directly */
		pci_read_config_dword(dev->pdev, 0x5c, &base);
		base &= ~((1<<20) - 1);
	} else { /* GEN2 */
#if 0
		/* Stolen is immediately above Top of Memory */
		base = max_low_pfn_mapped << PAGE_SHIFT;
#endif
	}

	if (base == 0)
		return 0;

	/* make sure we don't clobber the GTT if it's within stolen memory */
	if (INTEL_INFO(dev)->gen <= 4 && !IS_G33(dev) && !IS_G4X(dev)) {
		struct {
			u32 start, end;
		} stolen[2] = {
			{ .start = base, .end = base + dev_priv->gtt.stolen_size, },
			{ .start = base, .end = base + dev_priv->gtt.stolen_size, },
		};
		u64 gtt_start, gtt_end;

		gtt_start = I915_READ(PGTBL_CTL);
		if (IS_GEN4(dev))
			gtt_start = (gtt_start & PGTBL_ADDRESS_LO_MASK) |
				(gtt_start & PGTBL_ADDRESS_HI_MASK) << 28;
		else
			gtt_start &= PGTBL_ADDRESS_LO_MASK;
		gtt_end = gtt_start + gtt_total_entries(dev_priv->gtt) * 4;

		if (gtt_start >= stolen[0].start && gtt_start < stolen[0].end)
			stolen[0].end = gtt_start;
		if (gtt_end > stolen[1].start && gtt_end <= stolen[1].end)
			stolen[1].start = gtt_end;

		/* pick the larger of the two chunks */
		if (stolen[0].end - stolen[0].start >
		    stolen[1].end - stolen[1].start) {
			base = stolen[0].start;
			dev_priv->gtt.stolen_size = stolen[0].end - stolen[0].start;
		} else {
			base = stolen[1].start;
			dev_priv->gtt.stolen_size = stolen[1].end - stolen[1].start;
		}

		if (stolen[0].start != stolen[1].start ||
		    stolen[0].end != stolen[1].end) {
			DRM_DEBUG_KMS("GTT within stolen memory at 0x%llx-0x%llx\n",
				      (unsigned long long) gtt_start,
				      (unsigned long long) gtt_end - 1);
			DRM_DEBUG_KMS("Stolen memory adjusted to 0x%x-0x%x\n",
				      base, base + (u32) dev_priv->gtt.stolen_size - 1);
		}
	}


	/* Verify that nothing else uses this physical address. Stolen
	 * memory should be reserved by the BIOS and hidden from the
	 * kernel. So if the region is already marked as busy, something
	 * is seriously wrong.
	 */
	r = devm_request_mem_region(dev->dev, base, dev_priv->gtt.stolen_size,
				    "Graphics Stolen Memory");
	if (r == NULL) {
		/*
		 * One more attempt but this time requesting region from
		 * base + 1, as we have seen that this resolves the region
		 * conflict with the PCI Bus.
		 * This is a BIOS w/a: Some BIOS wrap stolen in the root
		 * PCI bus, but have an off-by-one error. Hence retry the
		 * reservation starting from 1 instead of 0.
		 */
		r = devm_request_mem_region(dev->dev, base + 1,
					    dev_priv->gtt.stolen_size - 1,
					    "Graphics Stolen Memory");
		/*
		 * GEN3 firmware likes to smash pci bridges into the stolen
		 * range. Apparently this works.
		 */
		if (r == NULL && !IS_GEN3(dev)) {
			DRM_ERROR("conflict detected with stolen region: [0x%08x - 0x%08x]\n",
				  base, base + (uint32_t)dev_priv->gtt.stolen_size);
			base = 0;
		}
	}

	return base;
}

static int find_compression_threshold(struct drm_device *dev,
				      struct drm_mm_node *node,
				      int size,
				      int fb_cpp)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	int compression_threshold = 1;
	int ret;

	/* HACK: This code depends on what we will do in *_enable_fbc. If that
	 * code changes, this code needs to change as well.
	 *
	 * The enable_fbc code will attempt to use one of our 2 compression
	 * thresholds, therefore, in that case, we only have 1 resort.
	 */

	/* Try to over-allocate to reduce reallocations and fragmentation. */
	ret = drm_mm_insert_node(&dev_priv->mm.stolen, node,
				 size <<= 1, 4096, DRM_MM_SEARCH_DEFAULT);
	if (ret == 0)
		return compression_threshold;

again:
	/* HW's ability to limit the CFB is 1:4 */
	if (compression_threshold > 4 ||
	    (fb_cpp == 2 && compression_threshold == 2))
		return 0;

	ret = drm_mm_insert_node(&dev_priv->mm.stolen, node,
				 size >>= 1, 4096,
				 DRM_MM_SEARCH_DEFAULT);
	if (ret && INTEL_INFO(dev)->gen <= 4) {
		return 0;
	} else if (ret) {
		compression_threshold <<= 1;
		goto again;
	} else {
		return compression_threshold;
	}
}

static int i915_setup_compression(struct drm_device *dev, int size, int fb_cpp)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	struct drm_mm_node *uninitialized_var(compressed_llb);
	int ret;

	ret = find_compression_threshold(dev, &dev_priv->fbc.compressed_fb,
					 size, fb_cpp);
	if (!ret)
		goto err_llb;
	else if (ret > 1) {
		DRM_INFO("Reducing the compressed framebuffer size. This may lead to less power savings than a non-reduced-size. Try to increase stolen memory size if available in BIOS.\n");

	}

	dev_priv->fbc.threshold = ret;

	if (HAS_PCH_SPLIT(dev))
		I915_WRITE(ILK_DPFC_CB_BASE, dev_priv->fbc.compressed_fb.start);
	else if (IS_GM45(dev)) {
		I915_WRITE(DPFC_CB_BASE, dev_priv->fbc.compressed_fb.start);
	} else {
		compressed_llb = kzalloc(sizeof(*compressed_llb), GFP_KERNEL);
		if (!compressed_llb)
			goto err_fb;

		ret = drm_mm_insert_node(&dev_priv->mm.stolen, compressed_llb,
					 4096, 4096, DRM_MM_SEARCH_DEFAULT);
		if (ret)
			goto err_fb;

		dev_priv->fbc.compressed_llb = compressed_llb;

		I915_WRITE(FBC_CFB_BASE,
			   dev_priv->mm.stolen_base + dev_priv->fbc.compressed_fb.start);
		I915_WRITE(FBC_LL_BASE,
			   dev_priv->mm.stolen_base + compressed_llb->start);
	}

	dev_priv->fbc.size = size / dev_priv->fbc.threshold;

	DRM_DEBUG_KMS("reserved %d bytes of contiguous stolen space for FBC\n",
		      size);

	return 0;

err_fb:
	kfree(compressed_llb);
	drm_mm_remove_node(&dev_priv->fbc.compressed_fb);
err_llb:
	pr_info_once("drm: not enough stolen space for compressed buffer (need %d more bytes), disabling. Hint: you may be able to increase stolen memory size in the BIOS to avoid this.\n", size);
	return -ENOSPC;
}

int i915_gem_stolen_setup_compression(struct drm_device *dev, int size, int fb_cpp)
{
	struct drm_i915_private *dev_priv = dev->dev_private;

	if (!drm_mm_initialized(&dev_priv->mm.stolen))
		return -ENODEV;

	if (size < dev_priv->fbc.size)
		return 0;

	/* Release any current block */
	i915_gem_stolen_cleanup_compression(dev);

	return i915_setup_compression(dev, size, fb_cpp);
}

void i915_gem_stolen_cleanup_compression(struct drm_device *dev)
{
	struct drm_i915_private *dev_priv = dev->dev_private;

	if (dev_priv->fbc.size == 0)
		return;

	drm_mm_remove_node(&dev_priv->fbc.compressed_fb);

	if (dev_priv->fbc.compressed_llb) {
		drm_mm_remove_node(dev_priv->fbc.compressed_llb);
		kfree(dev_priv->fbc.compressed_llb);
	}

	dev_priv->fbc.size = 0;
}

void i915_gem_cleanup_stolen(struct drm_device *dev)
{
	struct drm_i915_private *dev_priv = dev->dev_private;

	if (!drm_mm_initialized(&dev_priv->mm.stolen))
		return;

	i915_gem_stolen_cleanup_compression(dev);
	drm_mm_takedown(&dev_priv->mm.stolen);
}

int i915_gem_init_stolen(struct drm_device *dev)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	u32 tmp;
	int bios_reserved = 0;

#ifdef CONFIG_INTEL_IOMMU
	if (intel_iommu_gfx_mapped && INTEL_INFO(dev)->gen < 8) {
		DRM_INFO("DMAR active, disabling use of stolen memory\n");
		return 0;
	}
#endif

	if (dev_priv->gtt.stolen_size == 0)
		return 0;

	dev_priv->mm.stolen_base = i915_stolen_to_physical(dev);
	if (dev_priv->mm.stolen_base == 0)
		return 0;

	DRM_DEBUG_KMS("found %zd bytes of stolen memory at %08lx\n",
		      dev_priv->gtt.stolen_size, dev_priv->mm.stolen_base);

	if (INTEL_INFO(dev)->gen >= 8) {
		tmp = I915_READ(GEN7_BIOS_RESERVED);
		tmp >>= GEN8_BIOS_RESERVED_SHIFT;
		tmp &= GEN8_BIOS_RESERVED_MASK;
		bios_reserved = (1024*1024) << tmp;
	} else if (IS_GEN7(dev)) {
		tmp = I915_READ(GEN7_BIOS_RESERVED);
		bios_reserved = tmp & GEN7_BIOS_RESERVED_256K ?
			256*1024 : 1024*1024;
	}

	if (WARN_ON(bios_reserved > dev_priv->gtt.stolen_size))
		return 0;

	/* Basic memrange allocator for stolen space */
	drm_mm_init(&dev_priv->mm.stolen, 0, dev_priv->gtt.stolen_size -
		    bios_reserved);

	return 0;
}

static struct sg_table *
i915_pages_create_for_stolen(struct drm_device *dev,
			     u32 offset, u32 size)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	struct sg_table *st;
	struct scatterlist *sg;

	DRM_DEBUG_DRIVER("offset=0x%x, size=%d\n", offset, size);
	BUG_ON(offset > dev_priv->gtt.stolen_size - size);

	/* We hide that we have no struct page backing our stolen object
	 * by wrapping the contiguous physical allocation with a fake
	 * dma mapping in a single scatterlist.
	 */

	st = kmalloc(sizeof(*st), GFP_KERNEL);
	if (st == NULL)
		return NULL;

	if (sg_alloc_table(st, 1, GFP_KERNEL)) {
		kfree(st);
		return NULL;
	}

	sg = st->sgl;
	sg->offset = 0;
	sg->length = size;

	sg_dma_address(sg) = (dma_addr_t)dev_priv->mm.stolen_base + offset;
	sg_dma_len(sg) = size;

	return st;
}

static int i915_gem_object_get_pages_stolen(struct drm_i915_gem_object *obj)
{
	BUG();
	return -EINVAL;
}

static void i915_gem_object_put_pages_stolen(struct drm_i915_gem_object *obj)
{
	/* Should only be called during free */
	sg_free_table(obj->pages);
	kfree(obj->pages);
}


static void
i915_gem_object_release_stolen(struct drm_i915_gem_object *obj)
{
	if (obj->stolen) {
		drm_mm_remove_node(obj->stolen);
		kfree(obj->stolen);
		obj->stolen = NULL;
	}
}
static const struct drm_i915_gem_object_ops i915_gem_object_stolen_ops = {
	.get_pages = i915_gem_object_get_pages_stolen,
	.put_pages = i915_gem_object_put_pages_stolen,
	.release = i915_gem_object_release_stolen,
};

static struct drm_i915_gem_object *
_i915_gem_object_create_stolen(struct drm_device *dev,
			       struct drm_mm_node *stolen)
{
	struct drm_i915_gem_object *obj;

	obj = i915_gem_object_alloc(dev);
	if (obj == NULL)
		return NULL;

	drm_gem_private_object_init(dev, &obj->base, stolen->size);
	i915_gem_object_init(obj, &i915_gem_object_stolen_ops);

	obj->pages = i915_pages_create_for_stolen(dev,
						  stolen->start, stolen->size);
	if (obj->pages == NULL)
		goto cleanup;

	obj->has_dma_mapping = true;
	i915_gem_object_pin_pages(obj);
	obj->stolen = stolen;

	obj->base.read_domains = I915_GEM_DOMAIN_CPU | I915_GEM_DOMAIN_GTT;
	obj->cache_level = HAS_LLC(dev) ? I915_CACHE_LLC : I915_CACHE_NONE;

	return obj;

cleanup:
	i915_gem_object_free(obj);
	return NULL;
}

struct drm_i915_gem_object *
i915_gem_object_create_stolen(struct drm_device *dev, u32 size)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	struct drm_i915_gem_object *obj;
	struct drm_mm_node *stolen;
	int ret;

	if (!drm_mm_initialized(&dev_priv->mm.stolen))
		return NULL;

	DRM_DEBUG_KMS("creating stolen object: size=%x\n", size);
	if (size == 0)
		return NULL;

	stolen = kzalloc(sizeof(*stolen), GFP_KERNEL);
	if (!stolen)
		return NULL;

	ret = drm_mm_insert_node(&dev_priv->mm.stolen, stolen, size,
				 4096, DRM_MM_SEARCH_DEFAULT);
	if (ret) {
		kfree(stolen);
		return NULL;
	}

	obj = _i915_gem_object_create_stolen(dev, stolen);
	if (obj)
		return obj;

	drm_mm_remove_node(stolen);
	kfree(stolen);
	return NULL;
}

struct drm_i915_gem_object *
i915_gem_object_create_stolen_for_preallocated(struct drm_device *dev,
					       u32 stolen_offset,
					       u32 gtt_offset,
					       u32 size)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	struct i915_address_space *ggtt = &dev_priv->gtt.base;
	struct drm_i915_gem_object *obj;
	struct drm_mm_node *stolen;
	struct i915_vma *vma;
	int ret;

	if (!drm_mm_initialized(&dev_priv->mm.stolen))
		return NULL;

	DRM_DEBUG_KMS("creating preallocated stolen object: stolen_offset=%x, gtt_offset=%x, size=%x\n",
			stolen_offset, gtt_offset, size);

	/* KISS and expect everything to be page-aligned */
	if (WARN_ON(size == 0) || WARN_ON(size & 4095) ||
	    WARN_ON(stolen_offset & 4095))
		return NULL;

	stolen = kzalloc(sizeof(*stolen), GFP_KERNEL);
	if (!stolen)
		return NULL;

	stolen->start = stolen_offset;
	stolen->size = size;
	ret = drm_mm_reserve_node(&dev_priv->mm.stolen, stolen);
	if (ret) {
		DRM_DEBUG_KMS("failed to allocate stolen space\n");
		kfree(stolen);
		return NULL;
	}

	obj = _i915_gem_object_create_stolen(dev, stolen);
	if (obj == NULL) {
		DRM_DEBUG_KMS("failed to allocate stolen object\n");
		drm_mm_remove_node(stolen);
		kfree(stolen);
		return NULL;
	}

	/* Some objects just need physical mem from stolen space */
	if (gtt_offset == I915_GTT_OFFSET_NONE)
		return obj;

	vma = i915_gem_obj_lookup_or_create_vma(obj, ggtt);
	if (IS_ERR(vma)) {
		ret = PTR_ERR(vma);
		goto err_out;
	}

	/* To simplify the initialisation sequence between KMS and GTT,
	 * we allow construction of the stolen object prior to
	 * setting up the GTT space. The actual reservation will occur
	 * later.
	 */
	vma->node.start = gtt_offset;
	vma->node.size = size;
	if (drm_mm_initialized(&ggtt->mm)) {
		ret = drm_mm_reserve_node(&ggtt->mm, &vma->node);
		if (ret) {
			DRM_DEBUG_KMS("failed to allocate stolen GTT space\n");
			goto err_vma;
		}
	}

	vma->bound |= GLOBAL_BIND;

	list_add_tail(&obj->global_list, &dev_priv->mm.bound_list);
	list_add_tail(&vma->mm_list, &ggtt->inactive_list);
	i915_gem_object_pin_pages(obj);

	return obj;

err_vma:
	i915_gem_vma_destroy(vma);
err_out:
	drm_mm_remove_node(stolen);
	kfree(stolen);
	drm_gem_object_unreference(&obj->base);
	return NULL;
}