1/*
2 * Copyright © 2008-2012 Intel Corporation
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 * IN THE SOFTWARE.
22 *
23 * Authors:
24 *    Eric Anholt <eric@anholt.net>
25 *    Chris Wilson <chris@chris-wilson.co.uk>
26 *
27 */
28
29#include <drm/drmP.h>
30#include <drm/i915_drm.h>
31#include "i915_drv.h"
32
33/*
34 * The BIOS typically reserves some of the system's memory for the exclusive
35 * use of the integrated graphics. This memory is no longer available for
36 * use by the OS and so the user finds that his system has less memory
37 * available than he put in. We refer to this memory as stolen.
38 *
39 * The BIOS will allocate its framebuffer from the stolen memory. Our
40 * goal is try to reuse that object for our own fbcon which must always
41 * be available for panics. Anything else we can reuse the stolen memory
42 * for is a boon.
43 */
44
45static unsigned long i915_stolen_to_physical(struct drm_device *dev)
46{
47	struct drm_i915_private *dev_priv = dev->dev_private;
48	struct resource *r;
49	u32 base;
50
51	/* Almost universally we can find the Graphics Base of Stolen Memory
52	 * at offset 0x5c in the igfx configuration space. On a few (desktop)
53	 * machines this is also mirrored in the bridge device at different
54	 * locations, or in the MCHBAR. On gen2, the layout is again slightly
55	 * different with the Graphics Segment immediately following Top of
56	 * Memory (or Top of Usable DRAM). Note it appears that TOUD is only
57	 * reported by 865g, so we just use the top of memory as determined
58	 * by the e820 probe.
59	 *
60	 * XXX However gen2 requires an unavailable symbol.
61	 */
62	base = 0;
63	if (INTEL_INFO(dev)->gen >= 3) {
64		/* Read Graphics Base of Stolen Memory directly */
65		pci_read_config_dword(dev->pdev, 0x5c, &base);
66		base &= ~((1<<20) - 1);
67	} else { /* GEN2 */
68#if 0
69		/* Stolen is immediately above Top of Memory */
70		base = max_low_pfn_mapped << PAGE_SHIFT;
71#endif
72	}
73
74	if (base == 0)
75		return 0;
76
77	/* make sure we don't clobber the GTT if it's within stolen memory */
78	if (INTEL_INFO(dev)->gen <= 4 && !IS_G33(dev) && !IS_G4X(dev)) {
79		struct {
80			u32 start, end;
81		} stolen[2] = {
82			{ .start = base, .end = base + dev_priv->gtt.stolen_size, },
83			{ .start = base, .end = base + dev_priv->gtt.stolen_size, },
84		};
85		u64 gtt_start, gtt_end;
86
87		gtt_start = I915_READ(PGTBL_CTL);
88		if (IS_GEN4(dev))
89			gtt_start = (gtt_start & PGTBL_ADDRESS_LO_MASK) |
90				(gtt_start & PGTBL_ADDRESS_HI_MASK) << 28;
91		else
92			gtt_start &= PGTBL_ADDRESS_LO_MASK;
93		gtt_end = gtt_start + gtt_total_entries(dev_priv->gtt) * 4;
94
95		if (gtt_start >= stolen[0].start && gtt_start < stolen[0].end)
96			stolen[0].end = gtt_start;
97		if (gtt_end > stolen[1].start && gtt_end <= stolen[1].end)
98			stolen[1].start = gtt_end;
99
100		/* pick the larger of the two chunks */
101		if (stolen[0].end - stolen[0].start >
102		    stolen[1].end - stolen[1].start) {
103			base = stolen[0].start;
104			dev_priv->gtt.stolen_size = stolen[0].end - stolen[0].start;
105		} else {
106			base = stolen[1].start;
107			dev_priv->gtt.stolen_size = stolen[1].end - stolen[1].start;
108		}
109
110		if (stolen[0].start != stolen[1].start ||
111		    stolen[0].end != stolen[1].end) {
112			DRM_DEBUG_KMS("GTT within stolen memory at 0x%llx-0x%llx\n",
113				      (unsigned long long) gtt_start,
114				      (unsigned long long) gtt_end - 1);
115			DRM_DEBUG_KMS("Stolen memory adjusted to 0x%x-0x%x\n",
116				      base, base + (u32) dev_priv->gtt.stolen_size - 1);
117		}
118	}
119
120
121	/* Verify that nothing else uses this physical address. Stolen
122	 * memory should be reserved by the BIOS and hidden from the
123	 * kernel. So if the region is already marked as busy, something
124	 * is seriously wrong.
125	 */
126	r = devm_request_mem_region(dev->dev, base, dev_priv->gtt.stolen_size,
127				    "Graphics Stolen Memory");
128	if (r == NULL) {
129		/*
130		 * One more attempt but this time requesting region from
131		 * base + 1, as we have seen that this resolves the region
132		 * conflict with the PCI Bus.
133		 * This is a BIOS w/a: Some BIOS wrap stolen in the root
134		 * PCI bus, but have an off-by-one error. Hence retry the
135		 * reservation starting from 1 instead of 0.
136		 */
137		r = devm_request_mem_region(dev->dev, base + 1,
138					    dev_priv->gtt.stolen_size - 1,
139					    "Graphics Stolen Memory");
140		if (r == NULL) {
141			DRM_ERROR("conflict detected with stolen region: [0x%08x - 0x%08x]\n",
142				  base, base + (uint32_t)dev_priv->gtt.stolen_size);
143			base = 0;
144		}
145	}
146
147	return base;
148}
149
150static int find_compression_threshold(struct drm_device *dev,
151				      struct drm_mm_node *node,
152				      int size,
153				      int fb_cpp)
154{
155	struct drm_i915_private *dev_priv = dev->dev_private;
156	int compression_threshold = 1;
157	int ret;
158
159	/* HACK: This code depends on what we will do in *_enable_fbc. If that
160	 * code changes, this code needs to change as well.
161	 *
162	 * The enable_fbc code will attempt to use one of our 2 compression
163	 * thresholds, therefore, in that case, we only have 1 resort.
164	 */
165
166	/* Try to over-allocate to reduce reallocations and fragmentation. */
167	ret = drm_mm_insert_node(&dev_priv->mm.stolen, node,
168				 size <<= 1, 4096, DRM_MM_SEARCH_DEFAULT);
169	if (ret == 0)
170		return compression_threshold;
171
172again:
173	/* HW's ability to limit the CFB is 1:4 */
174	if (compression_threshold > 4 ||
175	    (fb_cpp == 2 && compression_threshold == 2))
176		return 0;
177
178	ret = drm_mm_insert_node(&dev_priv->mm.stolen, node,
179				 size >>= 1, 4096,
180				 DRM_MM_SEARCH_DEFAULT);
181	if (ret && INTEL_INFO(dev)->gen <= 4) {
182		return 0;
183	} else if (ret) {
184		compression_threshold <<= 1;
185		goto again;
186	} else {
187		return compression_threshold;
188	}
189}
190
191static int i915_setup_compression(struct drm_device *dev, int size, int fb_cpp)
192{
193	struct drm_i915_private *dev_priv = dev->dev_private;
194	struct drm_mm_node *uninitialized_var(compressed_llb);
195	int ret;
196
197	ret = find_compression_threshold(dev, &dev_priv->fbc.compressed_fb,
198					 size, fb_cpp);
199	if (!ret)
200		goto err_llb;
201	else if (ret > 1) {
202		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");
203
204	}
205
206	dev_priv->fbc.threshold = ret;
207
208	if (HAS_PCH_SPLIT(dev))
209		I915_WRITE(ILK_DPFC_CB_BASE, dev_priv->fbc.compressed_fb.start);
210	else if (IS_GM45(dev)) {
211		I915_WRITE(DPFC_CB_BASE, dev_priv->fbc.compressed_fb.start);
212	} else {
213		compressed_llb = kzalloc(sizeof(*compressed_llb), GFP_KERNEL);
214		if (!compressed_llb)
215			goto err_fb;
216
217		ret = drm_mm_insert_node(&dev_priv->mm.stolen, compressed_llb,
218					 4096, 4096, DRM_MM_SEARCH_DEFAULT);
219		if (ret)
220			goto err_fb;
221
222		dev_priv->fbc.compressed_llb = compressed_llb;
223
224		I915_WRITE(FBC_CFB_BASE,
225			   dev_priv->mm.stolen_base + dev_priv->fbc.compressed_fb.start);
226		I915_WRITE(FBC_LL_BASE,
227			   dev_priv->mm.stolen_base + compressed_llb->start);
228	}
229
230	dev_priv->fbc.size = size / dev_priv->fbc.threshold;
231
232	DRM_DEBUG_KMS("reserved %d bytes of contiguous stolen space for FBC\n",
233		      size);
234
235	return 0;
236
237err_fb:
238	kfree(compressed_llb);
239	drm_mm_remove_node(&dev_priv->fbc.compressed_fb);
240err_llb:
241	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);
242	return -ENOSPC;
243}
244
245int i915_gem_stolen_setup_compression(struct drm_device *dev, int size, int fb_cpp)
246{
247	struct drm_i915_private *dev_priv = dev->dev_private;
248
249	if (!drm_mm_initialized(&dev_priv->mm.stolen))
250		return -ENODEV;
251
252	if (size < dev_priv->fbc.size)
253		return 0;
254
255	/* Release any current block */
256	i915_gem_stolen_cleanup_compression(dev);
257
258	return i915_setup_compression(dev, size, fb_cpp);
259}
260
261void i915_gem_stolen_cleanup_compression(struct drm_device *dev)
262{
263	struct drm_i915_private *dev_priv = dev->dev_private;
264
265	if (dev_priv->fbc.size == 0)
266		return;
267
268	drm_mm_remove_node(&dev_priv->fbc.compressed_fb);
269
270	if (dev_priv->fbc.compressed_llb) {
271		drm_mm_remove_node(dev_priv->fbc.compressed_llb);
272		kfree(dev_priv->fbc.compressed_llb);
273	}
274
275	dev_priv->fbc.size = 0;
276}
277
278void i915_gem_cleanup_stolen(struct drm_device *dev)
279{
280	struct drm_i915_private *dev_priv = dev->dev_private;
281
282	if (!drm_mm_initialized(&dev_priv->mm.stolen))
283		return;
284
285	i915_gem_stolen_cleanup_compression(dev);
286	drm_mm_takedown(&dev_priv->mm.stolen);
287}
288
289int i915_gem_init_stolen(struct drm_device *dev)
290{
291	struct drm_i915_private *dev_priv = dev->dev_private;
292	u32 tmp;
293	int bios_reserved = 0;
294
295#ifdef CONFIG_INTEL_IOMMU
296	if (intel_iommu_gfx_mapped && INTEL_INFO(dev)->gen < 8) {
297		DRM_INFO("DMAR active, disabling use of stolen memory\n");
298		return 0;
299	}
300#endif
301
302	if (dev_priv->gtt.stolen_size == 0)
303		return 0;
304
305	dev_priv->mm.stolen_base = i915_stolen_to_physical(dev);
306	if (dev_priv->mm.stolen_base == 0)
307		return 0;
308
309	DRM_DEBUG_KMS("found %zd bytes of stolen memory at %08lx\n",
310		      dev_priv->gtt.stolen_size, dev_priv->mm.stolen_base);
311
312	if (INTEL_INFO(dev)->gen >= 8) {
313		tmp = I915_READ(GEN7_BIOS_RESERVED);
314		tmp >>= GEN8_BIOS_RESERVED_SHIFT;
315		tmp &= GEN8_BIOS_RESERVED_MASK;
316		bios_reserved = (1024*1024) << tmp;
317	} else if (IS_GEN7(dev)) {
318		tmp = I915_READ(GEN7_BIOS_RESERVED);
319		bios_reserved = tmp & GEN7_BIOS_RESERVED_256K ?
320			256*1024 : 1024*1024;
321	}
322
323	if (WARN_ON(bios_reserved > dev_priv->gtt.stolen_size))
324		return 0;
325
326	/* Basic memrange allocator for stolen space */
327	drm_mm_init(&dev_priv->mm.stolen, 0, dev_priv->gtt.stolen_size -
328		    bios_reserved);
329
330	return 0;
331}
332
333static struct sg_table *
334i915_pages_create_for_stolen(struct drm_device *dev,
335			     u32 offset, u32 size)
336{
337	struct drm_i915_private *dev_priv = dev->dev_private;
338	struct sg_table *st;
339	struct scatterlist *sg;
340
341	DRM_DEBUG_DRIVER("offset=0x%x, size=%d\n", offset, size);
342	BUG_ON(offset > dev_priv->gtt.stolen_size - size);
343
344	/* We hide that we have no struct page backing our stolen object
345	 * by wrapping the contiguous physical allocation with a fake
346	 * dma mapping in a single scatterlist.
347	 */
348
349	st = kmalloc(sizeof(*st), GFP_KERNEL);
350	if (st == NULL)
351		return NULL;
352
353	if (sg_alloc_table(st, 1, GFP_KERNEL)) {
354		kfree(st);
355		return NULL;
356	}
357
358	sg = st->sgl;
359	sg->offset = 0;
360	sg->length = size;
361
362	sg_dma_address(sg) = (dma_addr_t)dev_priv->mm.stolen_base + offset;
363	sg_dma_len(sg) = size;
364
365	return st;
366}
367
368static int i915_gem_object_get_pages_stolen(struct drm_i915_gem_object *obj)
369{
370	BUG();
371	return -EINVAL;
372}
373
374static void i915_gem_object_put_pages_stolen(struct drm_i915_gem_object *obj)
375{
376	/* Should only be called during free */
377	sg_free_table(obj->pages);
378	kfree(obj->pages);
379}
380
381
382static void
383i915_gem_object_release_stolen(struct drm_i915_gem_object *obj)
384{
385	if (obj->stolen) {
386		drm_mm_remove_node(obj->stolen);
387		kfree(obj->stolen);
388		obj->stolen = NULL;
389	}
390}
391static const struct drm_i915_gem_object_ops i915_gem_object_stolen_ops = {
392	.get_pages = i915_gem_object_get_pages_stolen,
393	.put_pages = i915_gem_object_put_pages_stolen,
394	.release = i915_gem_object_release_stolen,
395};
396
397static struct drm_i915_gem_object *
398_i915_gem_object_create_stolen(struct drm_device *dev,
399			       struct drm_mm_node *stolen)
400{
401	struct drm_i915_gem_object *obj;
402
403	obj = i915_gem_object_alloc(dev);
404	if (obj == NULL)
405		return NULL;
406
407	drm_gem_private_object_init(dev, &obj->base, stolen->size);
408	i915_gem_object_init(obj, &i915_gem_object_stolen_ops);
409
410	obj->pages = i915_pages_create_for_stolen(dev,
411						  stolen->start, stolen->size);
412	if (obj->pages == NULL)
413		goto cleanup;
414
415	obj->has_dma_mapping = true;
416	i915_gem_object_pin_pages(obj);
417	obj->stolen = stolen;
418
419	obj->base.read_domains = I915_GEM_DOMAIN_CPU | I915_GEM_DOMAIN_GTT;
420	obj->cache_level = HAS_LLC(dev) ? I915_CACHE_LLC : I915_CACHE_NONE;
421
422	return obj;
423
424cleanup:
425	i915_gem_object_free(obj);
426	return NULL;
427}
428
429struct drm_i915_gem_object *
430i915_gem_object_create_stolen(struct drm_device *dev, u32 size)
431{
432	struct drm_i915_private *dev_priv = dev->dev_private;
433	struct drm_i915_gem_object *obj;
434	struct drm_mm_node *stolen;
435	int ret;
436
437	if (!drm_mm_initialized(&dev_priv->mm.stolen))
438		return NULL;
439
440	DRM_DEBUG_KMS("creating stolen object: size=%x\n", size);
441	if (size == 0)
442		return NULL;
443
444	stolen = kzalloc(sizeof(*stolen), GFP_KERNEL);
445	if (!stolen)
446		return NULL;
447
448	ret = drm_mm_insert_node(&dev_priv->mm.stolen, stolen, size,
449				 4096, DRM_MM_SEARCH_DEFAULT);
450	if (ret) {
451		kfree(stolen);
452		return NULL;
453	}
454
455	obj = _i915_gem_object_create_stolen(dev, stolen);
456	if (obj)
457		return obj;
458
459	drm_mm_remove_node(stolen);
460	kfree(stolen);
461	return NULL;
462}
463
464struct drm_i915_gem_object *
465i915_gem_object_create_stolen_for_preallocated(struct drm_device *dev,
466					       u32 stolen_offset,
467					       u32 gtt_offset,
468					       u32 size)
469{
470	struct drm_i915_private *dev_priv = dev->dev_private;
471	struct i915_address_space *ggtt = &dev_priv->gtt.base;
472	struct drm_i915_gem_object *obj;
473	struct drm_mm_node *stolen;
474	struct i915_vma *vma;
475	int ret;
476
477	if (!drm_mm_initialized(&dev_priv->mm.stolen))
478		return NULL;
479
480	DRM_DEBUG_KMS("creating preallocated stolen object: stolen_offset=%x, gtt_offset=%x, size=%x\n",
481			stolen_offset, gtt_offset, size);
482
483	/* KISS and expect everything to be page-aligned */
484	BUG_ON(stolen_offset & 4095);
485	BUG_ON(size & 4095);
486
487	if (WARN_ON(size == 0))
488		return NULL;
489
490	stolen = kzalloc(sizeof(*stolen), GFP_KERNEL);
491	if (!stolen)
492		return NULL;
493
494	stolen->start = stolen_offset;
495	stolen->size = size;
496	ret = drm_mm_reserve_node(&dev_priv->mm.stolen, stolen);
497	if (ret) {
498		DRM_DEBUG_KMS("failed to allocate stolen space\n");
499		kfree(stolen);
500		return NULL;
501	}
502
503	obj = _i915_gem_object_create_stolen(dev, stolen);
504	if (obj == NULL) {
505		DRM_DEBUG_KMS("failed to allocate stolen object\n");
506		drm_mm_remove_node(stolen);
507		kfree(stolen);
508		return NULL;
509	}
510
511	/* Some objects just need physical mem from stolen space */
512	if (gtt_offset == I915_GTT_OFFSET_NONE)
513		return obj;
514
515	vma = i915_gem_obj_lookup_or_create_vma(obj, ggtt);
516	if (IS_ERR(vma)) {
517		ret = PTR_ERR(vma);
518		goto err_out;
519	}
520
521	/* To simplify the initialisation sequence between KMS and GTT,
522	 * we allow construction of the stolen object prior to
523	 * setting up the GTT space. The actual reservation will occur
524	 * later.
525	 */
526	vma->node.start = gtt_offset;
527	vma->node.size = size;
528	if (drm_mm_initialized(&ggtt->mm)) {
529		ret = drm_mm_reserve_node(&ggtt->mm, &vma->node);
530		if (ret) {
531			DRM_DEBUG_KMS("failed to allocate stolen GTT space\n");
532			goto err_vma;
533		}
534	}
535
536	obj->has_global_gtt_mapping = 1;
537
538	list_add_tail(&obj->global_list, &dev_priv->mm.bound_list);
539	list_add_tail(&vma->mm_list, &ggtt->inactive_list);
540	i915_gem_object_pin_pages(obj);
541
542	return obj;
543
544err_vma:
545	i915_gem_vma_destroy(vma);
546err_out:
547	drm_mm_remove_node(stolen);
548	kfree(stolen);
549	drm_gem_object_unreference(&obj->base);
550	return NULL;
551}
552