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;
48 struct pci_dev *pdev = dev_priv->bridge_dev;
51 /* On the machines I have tested the Graphics Base of Stolen Memory
52 * is unreliable, so on those compute the base by subtracting the
53 * stolen memory from the Top of Low Usable DRAM which is where the
54 * BIOS places the graphics stolen memory.
56 * On gen2, the layout is slightly different with the Graphics Segment
57 * immediately following Top of Memory (or Top of Usable DRAM). Note
58 * it appears that TOUD is only reported by 865g, so we just use the
59 * top of memory as determined by the e820 probe.
61 * XXX gen2 requires an unavailable symbol and 945gm fails with
65 if (INTEL_INFO(dev)->gen >= 6) {
66 /* Read Base Data of Stolen Memory Register (BDSM) directly.
67 * Note that there is also a MCHBAR miror at 0x1080c0 or
68 * we could use device 2:0x5c instead.
70 pci_read_config_dword(pdev, 0xB0, &base);
71 base &= ~4095; /* lower bits used for locking register */
72 } else if (INTEL_INFO(dev)->gen > 3 || IS_G33(dev)) {
73 /* Read Graphics Base of Stolen Memory directly */
74 pci_read_config_dword(pdev, 0xA4, &base);
76 } else if (IS_GEN3(dev)) {
78 /* Stolen is immediately below Top of Low Usable DRAM */
79 pci_read_config_byte(pdev, 0x9c, &val);
80 base = val >> 3 << 27;
81 base -= dev_priv->mm.gtt->stolen_size;
83 /* Stolen is immediately above Top of Memory */
84 base = max_low_pfn_mapped << PAGE_SHIFT;
91 static int i915_setup_compression(struct drm_device *dev, int size)
93 struct drm_i915_private *dev_priv = dev->dev_private;
94 struct drm_mm_node *compressed_fb, *uninitialized_var(compressed_llb);
96 /* Try to over-allocate to reduce reallocations and fragmentation */
97 compressed_fb = drm_mm_search_free(&dev_priv->mm.stolen,
100 compressed_fb = drm_mm_search_free(&dev_priv->mm.stolen,
101 size >>= 1, 4096, 0);
103 compressed_fb = drm_mm_get_block(compressed_fb, size, 4096);
107 if (HAS_PCH_SPLIT(dev))
108 I915_WRITE(ILK_DPFC_CB_BASE, compressed_fb->start);
109 else if (IS_GM45(dev)) {
110 I915_WRITE(DPFC_CB_BASE, compressed_fb->start);
112 compressed_llb = drm_mm_search_free(&dev_priv->mm.stolen,
115 compressed_llb = drm_mm_get_block(compressed_llb,
120 dev_priv->compressed_llb = compressed_llb;
122 I915_WRITE(FBC_CFB_BASE,
123 dev_priv->mm.stolen_base + compressed_fb->start);
124 I915_WRITE(FBC_LL_BASE,
125 dev_priv->mm.stolen_base + compressed_llb->start);
128 dev_priv->compressed_fb = compressed_fb;
129 dev_priv->cfb_size = size;
131 DRM_DEBUG_KMS("reserved %d bytes of contiguous stolen space for FBC\n",
137 drm_mm_put_block(compressed_fb);
142 int i915_gem_stolen_setup_compression(struct drm_device *dev, int size)
144 struct drm_i915_private *dev_priv = dev->dev_private;
146 if (dev_priv->mm.stolen_base == 0)
149 if (size < dev_priv->cfb_size)
152 /* Release any current block */
153 i915_gem_stolen_cleanup_compression(dev);
155 return i915_setup_compression(dev, size);
158 void i915_gem_stolen_cleanup_compression(struct drm_device *dev)
160 struct drm_i915_private *dev_priv = dev->dev_private;
162 if (dev_priv->cfb_size == 0)
165 if (dev_priv->compressed_fb)
166 drm_mm_put_block(dev_priv->compressed_fb);
168 if (dev_priv->compressed_llb)
169 drm_mm_put_block(dev_priv->compressed_llb);
171 dev_priv->cfb_size = 0;
174 void i915_gem_cleanup_stolen(struct drm_device *dev)
176 struct drm_i915_private *dev_priv = dev->dev_private;
178 i915_gem_stolen_cleanup_compression(dev);
179 drm_mm_takedown(&dev_priv->mm.stolen);
182 int i915_gem_init_stolen(struct drm_device *dev)
184 struct drm_i915_private *dev_priv = dev->dev_private;
186 dev_priv->mm.stolen_base = i915_stolen_to_physical(dev);
187 if (dev_priv->mm.stolen_base == 0)
190 DRM_DEBUG_KMS("found %zd bytes of stolen memory at %08lx\n",
191 dev_priv->gtt.stolen_size, dev_priv->mm.stolen_base);
193 /* Basic memrange allocator for stolen space */
194 drm_mm_init(&dev_priv->mm.stolen, 0, dev_priv->gtt.stolen_size);
199 static struct sg_table *
200 i915_pages_create_for_stolen(struct drm_device *dev,
201 u32 offset, u32 size)
203 struct drm_i915_private *dev_priv = dev->dev_private;
205 struct scatterlist *sg;
207 DRM_DEBUG_DRIVER("offset=0x%x, size=%d\n", offset, size);
208 BUG_ON(offset > dev_priv->gtt.stolen_size - size);
210 /* We hide that we have no struct page backing our stolen object
211 * by wrapping the contiguous physical allocation with a fake
212 * dma mapping in a single scatterlist.
215 st = kmalloc(sizeof(*st), GFP_KERNEL);
219 if (sg_alloc_table(st, 1, GFP_KERNEL)) {
228 sg_dma_address(sg) = (dma_addr_t)dev_priv->mm.stolen_base + offset;
229 sg_dma_len(sg) = size;
234 static int i915_gem_object_get_pages_stolen(struct drm_i915_gem_object *obj)
240 static void i915_gem_object_put_pages_stolen(struct drm_i915_gem_object *obj)
242 /* Should only be called during free */
243 sg_free_table(obj->pages);
247 static const struct drm_i915_gem_object_ops i915_gem_object_stolen_ops = {
248 .get_pages = i915_gem_object_get_pages_stolen,
249 .put_pages = i915_gem_object_put_pages_stolen,
252 static struct drm_i915_gem_object *
253 _i915_gem_object_create_stolen(struct drm_device *dev,
254 struct drm_mm_node *stolen)
256 struct drm_i915_gem_object *obj;
258 obj = i915_gem_object_alloc(dev);
262 if (drm_gem_private_object_init(dev, &obj->base, stolen->size))
265 i915_gem_object_init(obj, &i915_gem_object_stolen_ops);
267 obj->pages = i915_pages_create_for_stolen(dev,
268 stolen->start, stolen->size);
269 if (obj->pages == NULL)
272 obj->has_dma_mapping = true;
273 obj->pages_pin_count = 1;
274 obj->stolen = stolen;
276 obj->base.write_domain = I915_GEM_DOMAIN_GTT;
277 obj->base.read_domains = I915_GEM_DOMAIN_GTT;
278 obj->cache_level = I915_CACHE_NONE;
283 i915_gem_object_free(obj);
287 struct drm_i915_gem_object *
288 i915_gem_object_create_stolen(struct drm_device *dev, u32 size)
290 struct drm_i915_private *dev_priv = dev->dev_private;
291 struct drm_i915_gem_object *obj;
292 struct drm_mm_node *stolen;
294 if (dev_priv->mm.stolen_base == 0)
297 DRM_DEBUG_KMS("creating stolen object: size=%x\n", size);
301 stolen = drm_mm_search_free(&dev_priv->mm.stolen, size, 4096, 0);
303 stolen = drm_mm_get_block(stolen, size, 4096);
307 obj = _i915_gem_object_create_stolen(dev, stolen);
311 drm_mm_put_block(stolen);
315 struct drm_i915_gem_object *
316 i915_gem_object_create_stolen_for_preallocated(struct drm_device *dev,
321 struct drm_i915_private *dev_priv = dev->dev_private;
322 struct drm_i915_gem_object *obj;
323 struct drm_mm_node *stolen;
325 if (dev_priv->mm.stolen_base == 0)
328 DRM_DEBUG_KMS("creating preallocated stolen object: stolen_offset=%x, gtt_offset=%x, size=%x\n",
329 stolen_offset, gtt_offset, size);
331 /* KISS and expect everything to be page-aligned */
332 BUG_ON(stolen_offset & 4095);
333 BUG_ON(gtt_offset & 4095);
336 if (WARN_ON(size == 0))
339 stolen = drm_mm_create_block(&dev_priv->mm.stolen,
342 if (stolen == NULL) {
343 DRM_DEBUG_KMS("failed to allocate stolen space\n");
347 obj = _i915_gem_object_create_stolen(dev, stolen);
349 DRM_DEBUG_KMS("failed to allocate stolen object\n");
350 drm_mm_put_block(stolen);
354 /* To simplify the initialisation sequence between KMS and GTT,
355 * we allow construction of the stolen object prior to
356 * setting up the GTT space. The actual reservation will occur
359 if (drm_mm_initialized(&dev_priv->mm.gtt_space)) {
360 obj->gtt_space = drm_mm_create_block(&dev_priv->mm.gtt_space,
363 if (obj->gtt_space == NULL) {
364 DRM_DEBUG_KMS("failed to allocate stolen GTT space\n");
365 drm_gem_object_unreference(&obj->base);
369 obj->gtt_space = I915_GTT_RESERVED;
371 obj->gtt_offset = gtt_offset;
372 obj->has_global_gtt_mapping = 1;
374 list_add_tail(&obj->gtt_list, &dev_priv->mm.bound_list);
375 list_add_tail(&obj->mm_list, &dev_priv->mm.inactive_list);
381 i915_gem_object_release_stolen(struct drm_i915_gem_object *obj)
384 drm_mm_put_block(obj->stolen);