2 * Copyright © 2008-2012 Intel Corporation
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:
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
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
24 * Eric Anholt <eric@anholt.net>
25 * Chris Wilson <chris@chris-wilson.co.uk>
30 #include <drm/i915_drm.h>
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.
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
45 static unsigned long i915_stolen_to_physical(struct drm_device *dev)
47 struct drm_i915_private *dev_priv = dev->dev_private;
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
60 * XXX However gen2 requires an unavailable symbol.
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);
69 /* Stolen is immediately above Top of Memory */
70 base = max_low_pfn_mapped << PAGE_SHIFT;
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)) {
82 { .start = base, .end = base + dev_priv->gtt.stolen_size, },
83 { .start = base, .end = base + dev_priv->gtt.stolen_size, },
85 u64 gtt_start, gtt_end;
87 gtt_start = I915_READ(PGTBL_CTL);
89 gtt_start = (gtt_start & PGTBL_ADDRESS_LO_MASK) |
90 (gtt_start & PGTBL_ADDRESS_HI_MASK) << 28;
92 gtt_start &= PGTBL_ADDRESS_LO_MASK;
93 gtt_end = gtt_start + gtt_total_entries(dev_priv->gtt) * 4;
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;
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;
106 base = stolen[1].start;
107 dev_priv->gtt.stolen_size = stolen[1].end - stolen[1].start;
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);
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.
126 r = devm_request_mem_region(dev->dev, base, dev_priv->gtt.stolen_size,
127 "Graphics Stolen Memory");
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.
137 r = devm_request_mem_region(dev->dev, base + 1,
138 dev_priv->gtt.stolen_size - 1,
139 "Graphics Stolen Memory");
141 DRM_ERROR("conflict detected with stolen region: [0x%08x - 0x%08x]\n",
142 base, base + (uint32_t)dev_priv->gtt.stolen_size);
150 static int find_compression_threshold(struct drm_device *dev,
151 struct drm_mm_node *node,
155 struct drm_i915_private *dev_priv = dev->dev_private;
156 int compression_threshold = 1;
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.
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.
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);
170 return compression_threshold;
173 /* HW's ability to limit the CFB is 1:4 */
174 if (compression_threshold > 4 ||
175 (fb_cpp == 2 && compression_threshold == 2))
178 ret = drm_mm_insert_node(&dev_priv->mm.stolen, node,
180 DRM_MM_SEARCH_DEFAULT);
181 if (ret && INTEL_INFO(dev)->gen <= 4) {
184 compression_threshold <<= 1;
187 return compression_threshold;
191 static int i915_setup_compression(struct drm_device *dev, int size, int fb_cpp)
193 struct drm_i915_private *dev_priv = dev->dev_private;
194 struct drm_mm_node *uninitialized_var(compressed_llb);
197 ret = find_compression_threshold(dev, &dev_priv->fbc.compressed_fb,
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");
206 dev_priv->fbc.threshold = ret;
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);
213 compressed_llb = kzalloc(sizeof(*compressed_llb), GFP_KERNEL);
217 ret = drm_mm_insert_node(&dev_priv->mm.stolen, compressed_llb,
218 4096, 4096, DRM_MM_SEARCH_DEFAULT);
222 dev_priv->fbc.compressed_llb = compressed_llb;
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);
230 dev_priv->fbc.size = size / dev_priv->fbc.threshold;
232 DRM_DEBUG_KMS("reserved %d bytes of contiguous stolen space for FBC\n",
238 kfree(compressed_llb);
239 drm_mm_remove_node(&dev_priv->fbc.compressed_fb);
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);
245 int i915_gem_stolen_setup_compression(struct drm_device *dev, int size, int fb_cpp)
247 struct drm_i915_private *dev_priv = dev->dev_private;
249 if (!drm_mm_initialized(&dev_priv->mm.stolen))
252 if (size < dev_priv->fbc.size)
255 /* Release any current block */
256 i915_gem_stolen_cleanup_compression(dev);
258 return i915_setup_compression(dev, size, fb_cpp);
261 void i915_gem_stolen_cleanup_compression(struct drm_device *dev)
263 struct drm_i915_private *dev_priv = dev->dev_private;
265 if (dev_priv->fbc.size == 0)
268 drm_mm_remove_node(&dev_priv->fbc.compressed_fb);
270 if (dev_priv->fbc.compressed_llb) {
271 drm_mm_remove_node(dev_priv->fbc.compressed_llb);
272 kfree(dev_priv->fbc.compressed_llb);
275 dev_priv->fbc.size = 0;
278 void i915_gem_cleanup_stolen(struct drm_device *dev)
280 struct drm_i915_private *dev_priv = dev->dev_private;
282 if (!drm_mm_initialized(&dev_priv->mm.stolen))
285 i915_gem_stolen_cleanup_compression(dev);
286 drm_mm_takedown(&dev_priv->mm.stolen);
289 int i915_gem_init_stolen(struct drm_device *dev)
291 struct drm_i915_private *dev_priv = dev->dev_private;
292 int bios_reserved = 0;
294 #ifdef CONFIG_INTEL_IOMMU
295 if (intel_iommu_gfx_mapped && INTEL_INFO(dev)->gen < 8) {
296 DRM_INFO("DMAR active, disabling use of stolen memory\n");
301 if (dev_priv->gtt.stolen_size == 0)
304 dev_priv->mm.stolen_base = i915_stolen_to_physical(dev);
305 if (dev_priv->mm.stolen_base == 0)
308 DRM_DEBUG_KMS("found %zd bytes of stolen memory at %08lx\n",
309 dev_priv->gtt.stolen_size, dev_priv->mm.stolen_base);
311 if (IS_VALLEYVIEW(dev))
312 bios_reserved = 1024*1024; /* top 1M on VLV/BYT */
314 if (WARN_ON(bios_reserved > dev_priv->gtt.stolen_size))
317 /* Basic memrange allocator for stolen space */
318 drm_mm_init(&dev_priv->mm.stolen, 0, dev_priv->gtt.stolen_size -
324 static struct sg_table *
325 i915_pages_create_for_stolen(struct drm_device *dev,
326 u32 offset, u32 size)
328 struct drm_i915_private *dev_priv = dev->dev_private;
330 struct scatterlist *sg;
332 DRM_DEBUG_DRIVER("offset=0x%x, size=%d\n", offset, size);
333 BUG_ON(offset > dev_priv->gtt.stolen_size - size);
335 /* We hide that we have no struct page backing our stolen object
336 * by wrapping the contiguous physical allocation with a fake
337 * dma mapping in a single scatterlist.
340 st = kmalloc(sizeof(*st), GFP_KERNEL);
344 if (sg_alloc_table(st, 1, GFP_KERNEL)) {
353 sg_dma_address(sg) = (dma_addr_t)dev_priv->mm.stolen_base + offset;
354 sg_dma_len(sg) = size;
359 static int i915_gem_object_get_pages_stolen(struct drm_i915_gem_object *obj)
365 static void i915_gem_object_put_pages_stolen(struct drm_i915_gem_object *obj)
367 /* Should only be called during free */
368 sg_free_table(obj->pages);
374 i915_gem_object_release_stolen(struct drm_i915_gem_object *obj)
377 drm_mm_remove_node(obj->stolen);
382 static const struct drm_i915_gem_object_ops i915_gem_object_stolen_ops = {
383 .get_pages = i915_gem_object_get_pages_stolen,
384 .put_pages = i915_gem_object_put_pages_stolen,
385 .release = i915_gem_object_release_stolen,
388 static struct drm_i915_gem_object *
389 _i915_gem_object_create_stolen(struct drm_device *dev,
390 struct drm_mm_node *stolen)
392 struct drm_i915_gem_object *obj;
394 obj = i915_gem_object_alloc(dev);
398 drm_gem_private_object_init(dev, &obj->base, stolen->size);
399 i915_gem_object_init(obj, &i915_gem_object_stolen_ops);
401 obj->pages = i915_pages_create_for_stolen(dev,
402 stolen->start, stolen->size);
403 if (obj->pages == NULL)
406 obj->has_dma_mapping = true;
407 i915_gem_object_pin_pages(obj);
408 obj->stolen = stolen;
410 obj->base.read_domains = I915_GEM_DOMAIN_CPU | I915_GEM_DOMAIN_GTT;
411 obj->cache_level = HAS_LLC(dev) ? I915_CACHE_LLC : I915_CACHE_NONE;
416 i915_gem_object_free(obj);
420 struct drm_i915_gem_object *
421 i915_gem_object_create_stolen(struct drm_device *dev, u32 size)
423 struct drm_i915_private *dev_priv = dev->dev_private;
424 struct drm_i915_gem_object *obj;
425 struct drm_mm_node *stolen;
428 if (!drm_mm_initialized(&dev_priv->mm.stolen))
431 DRM_DEBUG_KMS("creating stolen object: size=%x\n", size);
435 stolen = kzalloc(sizeof(*stolen), GFP_KERNEL);
439 ret = drm_mm_insert_node(&dev_priv->mm.stolen, stolen, size,
440 4096, DRM_MM_SEARCH_DEFAULT);
446 obj = _i915_gem_object_create_stolen(dev, stolen);
450 drm_mm_remove_node(stolen);
455 struct drm_i915_gem_object *
456 i915_gem_object_create_stolen_for_preallocated(struct drm_device *dev,
461 struct drm_i915_private *dev_priv = dev->dev_private;
462 struct i915_address_space *ggtt = &dev_priv->gtt.base;
463 struct drm_i915_gem_object *obj;
464 struct drm_mm_node *stolen;
465 struct i915_vma *vma;
468 if (!drm_mm_initialized(&dev_priv->mm.stolen))
471 DRM_DEBUG_KMS("creating preallocated stolen object: stolen_offset=%x, gtt_offset=%x, size=%x\n",
472 stolen_offset, gtt_offset, size);
474 /* KISS and expect everything to be page-aligned */
475 BUG_ON(stolen_offset & 4095);
478 if (WARN_ON(size == 0))
481 stolen = kzalloc(sizeof(*stolen), GFP_KERNEL);
485 stolen->start = stolen_offset;
487 ret = drm_mm_reserve_node(&dev_priv->mm.stolen, stolen);
489 DRM_DEBUG_KMS("failed to allocate stolen space\n");
494 obj = _i915_gem_object_create_stolen(dev, stolen);
496 DRM_DEBUG_KMS("failed to allocate stolen object\n");
497 drm_mm_remove_node(stolen);
502 /* Some objects just need physical mem from stolen space */
503 if (gtt_offset == I915_GTT_OFFSET_NONE)
506 vma = i915_gem_obj_lookup_or_create_vma(obj, ggtt);
512 /* To simplify the initialisation sequence between KMS and GTT,
513 * we allow construction of the stolen object prior to
514 * setting up the GTT space. The actual reservation will occur
517 vma->node.start = gtt_offset;
518 vma->node.size = size;
519 if (drm_mm_initialized(&ggtt->mm)) {
520 ret = drm_mm_reserve_node(&ggtt->mm, &vma->node);
522 DRM_DEBUG_KMS("failed to allocate stolen GTT space\n");
527 obj->has_global_gtt_mapping = 1;
529 list_add_tail(&obj->global_list, &dev_priv->mm.bound_list);
530 list_add_tail(&vma->mm_list, &ggtt->inactive_list);
531 i915_gem_object_pin_pages(obj);
536 i915_gem_vma_destroy(vma);
538 drm_mm_remove_node(stolen);
540 drm_gem_object_unreference(&obj->base);