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	/* Verify that nothing else uses this physical address. Stolen
 78	 * memory should be reserved by the BIOS and hidden from the
 79	 * kernel. So if the region is already marked as busy, something
 80	 * is seriously wrong.
 81	 */
 82	r = devm_request_mem_region(dev->dev, base, dev_priv->gtt.stolen_size,
 83				    "Graphics Stolen Memory");
 84	if (r == NULL) {
 85		/*
 86		 * One more attempt but this time requesting region from
 87		 * base + 1, as we have seen that this resolves the region
 88		 * conflict with the PCI Bus.
 89		 * This is a BIOS w/a: Some BIOS wrap stolen in the root
 90		 * PCI bus, but have an off-by-one error. Hence retry the
 91		 * reservation starting from 1 instead of 0.
 92		 */
 93		r = devm_request_mem_region(dev->dev, base + 1,
 94					    dev_priv->gtt.stolen_size - 1,
 95					    "Graphics Stolen Memory");
 96		if (r == NULL) {
 97			DRM_ERROR("conflict detected with stolen region: [0x%08x - 0x%08x]\n",
 98				  base, base + (uint32_t)dev_priv->gtt.stolen_size);
 99			base = 0;
100		}
101	}
102
103	return base;
104}
105
106static int i915_setup_compression(struct drm_device *dev, int size)
107{
108	struct drm_i915_private *dev_priv = dev->dev_private;
109	struct drm_mm_node *compressed_fb, *uninitialized_var(compressed_llb);
110	int ret;
111
112	compressed_fb = kzalloc(sizeof(*compressed_fb), GFP_KERNEL);
113	if (!compressed_fb)
114		goto err_llb;
115
116	/* Try to over-allocate to reduce reallocations and fragmentation */
117	ret = drm_mm_insert_node(&dev_priv->mm.stolen, compressed_fb,
118				 size <<= 1, 4096, DRM_MM_SEARCH_DEFAULT);
119	if (ret)
120		ret = drm_mm_insert_node(&dev_priv->mm.stolen, compressed_fb,
121					 size >>= 1, 4096,
122					 DRM_MM_SEARCH_DEFAULT);
123	if (ret)
124		goto err_llb;
125
126	if (HAS_PCH_SPLIT(dev))
127		I915_WRITE(ILK_DPFC_CB_BASE, compressed_fb->start);
128	else if (IS_GM45(dev)) {
129		I915_WRITE(DPFC_CB_BASE, compressed_fb->start);
130	} else {
131		compressed_llb = kzalloc(sizeof(*compressed_llb), GFP_KERNEL);
132		if (!compressed_llb)
133			goto err_fb;
134
135		ret = drm_mm_insert_node(&dev_priv->mm.stolen, compressed_llb,
136					 4096, 4096, DRM_MM_SEARCH_DEFAULT);
137		if (ret)
138			goto err_fb;
139
140		dev_priv->fbc.compressed_llb = compressed_llb;
141
142		I915_WRITE(FBC_CFB_BASE,
143			   dev_priv->mm.stolen_base + compressed_fb->start);
144		I915_WRITE(FBC_LL_BASE,
145			   dev_priv->mm.stolen_base + compressed_llb->start);
146	}
147
148	dev_priv->fbc.compressed_fb = compressed_fb;
149	dev_priv->fbc.size = size;
150
151	DRM_DEBUG_KMS("reserved %d bytes of contiguous stolen space for FBC\n",
152		      size);
153
154	return 0;
155
156err_fb:
157	kfree(compressed_llb);
158	drm_mm_remove_node(compressed_fb);
159err_llb:
160	kfree(compressed_fb);
161	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);
162	return -ENOSPC;
163}
164
165int i915_gem_stolen_setup_compression(struct drm_device *dev, int size)
166{
167	struct drm_i915_private *dev_priv = dev->dev_private;
168
169	if (!drm_mm_initialized(&dev_priv->mm.stolen))
170		return -ENODEV;
171
172	if (size < dev_priv->fbc.size)
173		return 0;
174
175	/* Release any current block */
176	i915_gem_stolen_cleanup_compression(dev);
177
178	return i915_setup_compression(dev, size);
179}
180
181void i915_gem_stolen_cleanup_compression(struct drm_device *dev)
182{
183	struct drm_i915_private *dev_priv = dev->dev_private;
184
185	if (dev_priv->fbc.size == 0)
186		return;
187
188	if (dev_priv->fbc.compressed_fb) {
189		drm_mm_remove_node(dev_priv->fbc.compressed_fb);
190		kfree(dev_priv->fbc.compressed_fb);
191	}
192
193	if (dev_priv->fbc.compressed_llb) {
194		drm_mm_remove_node(dev_priv->fbc.compressed_llb);
195		kfree(dev_priv->fbc.compressed_llb);
196	}
197
198	dev_priv->fbc.size = 0;
199}
200
201void i915_gem_cleanup_stolen(struct drm_device *dev)
202{
203	struct drm_i915_private *dev_priv = dev->dev_private;
204
205	if (!drm_mm_initialized(&dev_priv->mm.stolen))
206		return;
207
208	i915_gem_stolen_cleanup_compression(dev);
209	drm_mm_takedown(&dev_priv->mm.stolen);
210}
211
212int i915_gem_init_stolen(struct drm_device *dev)
213{
214	struct drm_i915_private *dev_priv = dev->dev_private;
215	int bios_reserved = 0;
216
217#ifdef CONFIG_INTEL_IOMMU
218	if (intel_iommu_gfx_mapped && INTEL_INFO(dev)->gen < 8) {
219		DRM_INFO("DMAR active, disabling use of stolen memory\n");
220		return 0;
221	}
222#endif
223
224	if (dev_priv->gtt.stolen_size == 0)
225		return 0;
226
227	dev_priv->mm.stolen_base = i915_stolen_to_physical(dev);
228	if (dev_priv->mm.stolen_base == 0)
229		return 0;
230
231	DRM_DEBUG_KMS("found %zd bytes of stolen memory at %08lx\n",
232		      dev_priv->gtt.stolen_size, dev_priv->mm.stolen_base);
233
234	if (IS_VALLEYVIEW(dev))
235		bios_reserved = 1024*1024; /* top 1M on VLV/BYT */
236
237	if (WARN_ON(bios_reserved > dev_priv->gtt.stolen_size))
238		return 0;
239
240	/* Basic memrange allocator for stolen space */
241	drm_mm_init(&dev_priv->mm.stolen, 0, dev_priv->gtt.stolen_size -
242		    bios_reserved);
243
244	return 0;
245}
246
247static struct sg_table *
248i915_pages_create_for_stolen(struct drm_device *dev,
249			     u32 offset, u32 size)
250{
251	struct drm_i915_private *dev_priv = dev->dev_private;
252	struct sg_table *st;
253	struct scatterlist *sg;
254
255	DRM_DEBUG_DRIVER("offset=0x%x, size=%d\n", offset, size);
256	BUG_ON(offset > dev_priv->gtt.stolen_size - size);
257
258	/* We hide that we have no struct page backing our stolen object
259	 * by wrapping the contiguous physical allocation with a fake
260	 * dma mapping in a single scatterlist.
261	 */
262
263	st = kmalloc(sizeof(*st), GFP_KERNEL);
264	if (st == NULL)
265		return NULL;
266
267	if (sg_alloc_table(st, 1, GFP_KERNEL)) {
268		kfree(st);
269		return NULL;
270	}
271
272	sg = st->sgl;
273	sg->offset = 0;
274	sg->length = size;
275
276	sg_dma_address(sg) = (dma_addr_t)dev_priv->mm.stolen_base + offset;
277	sg_dma_len(sg) = size;
278
279	return st;
280}
281
282static int i915_gem_object_get_pages_stolen(struct drm_i915_gem_object *obj)
283{
284	BUG();
285	return -EINVAL;
286}
287
288static void i915_gem_object_put_pages_stolen(struct drm_i915_gem_object *obj)
289{
290	/* Should only be called during free */
291	sg_free_table(obj->pages);
292	kfree(obj->pages);
293}
294
295static const struct drm_i915_gem_object_ops i915_gem_object_stolen_ops = {
296	.get_pages = i915_gem_object_get_pages_stolen,
297	.put_pages = i915_gem_object_put_pages_stolen,
298};
299
300static struct drm_i915_gem_object *
301_i915_gem_object_create_stolen(struct drm_device *dev,
302			       struct drm_mm_node *stolen)
303{
304	struct drm_i915_gem_object *obj;
305
306	obj = i915_gem_object_alloc(dev);
307	if (obj == NULL)
308		return NULL;
309
310	drm_gem_private_object_init(dev, &obj->base, stolen->size);
311	i915_gem_object_init(obj, &i915_gem_object_stolen_ops);
312
313	obj->pages = i915_pages_create_for_stolen(dev,
314						  stolen->start, stolen->size);
315	if (obj->pages == NULL)
316		goto cleanup;
317
318	obj->has_dma_mapping = true;
319	i915_gem_object_pin_pages(obj);
320	obj->stolen = stolen;
321
322	obj->base.read_domains = I915_GEM_DOMAIN_CPU | I915_GEM_DOMAIN_GTT;
323	obj->cache_level = HAS_LLC(dev) ? I915_CACHE_LLC : I915_CACHE_NONE;
324
325	return obj;
326
327cleanup:
328	i915_gem_object_free(obj);
329	return NULL;
330}
331
332struct drm_i915_gem_object *
333i915_gem_object_create_stolen(struct drm_device *dev, u32 size)
334{
335	struct drm_i915_private *dev_priv = dev->dev_private;
336	struct drm_i915_gem_object *obj;
337	struct drm_mm_node *stolen;
338	int ret;
339
340	if (!drm_mm_initialized(&dev_priv->mm.stolen))
341		return NULL;
342
343	DRM_DEBUG_KMS("creating stolen object: size=%x\n", size);
344	if (size == 0)
345		return NULL;
346
347	stolen = kzalloc(sizeof(*stolen), GFP_KERNEL);
348	if (!stolen)
349		return NULL;
350
351	ret = drm_mm_insert_node(&dev_priv->mm.stolen, stolen, size,
352				 4096, DRM_MM_SEARCH_DEFAULT);
353	if (ret) {
354		kfree(stolen);
355		return NULL;
356	}
357
358	obj = _i915_gem_object_create_stolen(dev, stolen);
359	if (obj)
360		return obj;
361
362	drm_mm_remove_node(stolen);
363	kfree(stolen);
364	return NULL;
365}
366
367struct drm_i915_gem_object *
368i915_gem_object_create_stolen_for_preallocated(struct drm_device *dev,
369					       u32 stolen_offset,
370					       u32 gtt_offset,
371					       u32 size)
372{
373	struct drm_i915_private *dev_priv = dev->dev_private;
374	struct i915_address_space *ggtt = &dev_priv->gtt.base;
375	struct drm_i915_gem_object *obj;
376	struct drm_mm_node *stolen;
377	struct i915_vma *vma;
378	int ret;
379
380	if (!drm_mm_initialized(&dev_priv->mm.stolen))
381		return NULL;
382
383	DRM_DEBUG_KMS("creating preallocated stolen object: stolen_offset=%x, gtt_offset=%x, size=%x\n",
384			stolen_offset, gtt_offset, size);
385
386	/* KISS and expect everything to be page-aligned */
387	BUG_ON(stolen_offset & 4095);
388	BUG_ON(size & 4095);
389
390	if (WARN_ON(size == 0))
391		return NULL;
392
393	stolen = kzalloc(sizeof(*stolen), GFP_KERNEL);
394	if (!stolen)
395		return NULL;
396
397	stolen->start = stolen_offset;
398	stolen->size = size;
399	ret = drm_mm_reserve_node(&dev_priv->mm.stolen, stolen);
400	if (ret) {
401		DRM_DEBUG_KMS("failed to allocate stolen space\n");
402		kfree(stolen);
403		return NULL;
404	}
405
406	obj = _i915_gem_object_create_stolen(dev, stolen);
407	if (obj == NULL) {
408		DRM_DEBUG_KMS("failed to allocate stolen object\n");
409		drm_mm_remove_node(stolen);
410		kfree(stolen);
411		return NULL;
412	}
413
414	/* Some objects just need physical mem from stolen space */
415	if (gtt_offset == I915_GTT_OFFSET_NONE)
416		return obj;
417
418	vma = i915_gem_obj_lookup_or_create_vma(obj, ggtt);
419	if (IS_ERR(vma)) {
420		ret = PTR_ERR(vma);
421		goto err_out;
422	}
423
424	/* To simplify the initialisation sequence between KMS and GTT,
425	 * we allow construction of the stolen object prior to
426	 * setting up the GTT space. The actual reservation will occur
427	 * later.
428	 */
429	vma->node.start = gtt_offset;
430	vma->node.size = size;
431	if (drm_mm_initialized(&ggtt->mm)) {
432		ret = drm_mm_reserve_node(&ggtt->mm, &vma->node);
433		if (ret) {
434			DRM_DEBUG_KMS("failed to allocate stolen GTT space\n");
435			goto err_vma;
436		}
437	}
438
439	obj->has_global_gtt_mapping = 1;
440
441	list_add_tail(&obj->global_list, &dev_priv->mm.bound_list);
442	list_add_tail(&vma->mm_list, &ggtt->inactive_list);
443	i915_gem_object_pin_pages(obj);
444
445	return obj;
446
447err_vma:
448	i915_gem_vma_destroy(vma);
449err_out:
450	drm_mm_remove_node(stolen);
451	kfree(stolen);
452	drm_gem_object_unreference(&obj->base);
453	return NULL;
454}
455
456void
457i915_gem_object_release_stolen(struct drm_i915_gem_object *obj)
458{
459	if (obj->stolen) {
460		drm_mm_remove_node(obj->stolen);
461		kfree(obj->stolen);
462		obj->stolen = NULL;
463	}
464}