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 (IS_VALLEYVIEW(dev)) {
66 pci_read_config_dword(dev->pdev, 0x5c, &base);
67 base &= ~((1<<20) - 1);
68 } else if (INTEL_INFO(dev)->gen >= 6) {
69 /* Read Base Data of Stolen Memory Register (BDSM) directly.
70 * Note that there is also a MCHBAR miror at 0x1080c0 or
71 * we could use device 2:0x5c instead.
73 pci_read_config_dword(pdev, 0xB0, &base);
74 base &= ~4095; /* lower bits used for locking register */
75 } else if (INTEL_INFO(dev)->gen > 3 || IS_G33(dev)) {
76 /* Read Graphics Base of Stolen Memory directly */
77 pci_read_config_dword(pdev, 0xA4, &base);
79 } else if (IS_GEN3(dev)) {
81 /* Stolen is immediately below Top of Low Usable DRAM */
82 pci_read_config_byte(pdev, 0x9c, &val);
83 base = val >> 3 << 27;
84 base -= dev_priv->mm.gtt->stolen_size;
86 /* Stolen is immediately above Top of Memory */
87 base = max_low_pfn_mapped << PAGE_SHIFT;
94 static int i915_setup_compression(struct drm_device *dev, int size)
96 struct drm_i915_private *dev_priv = dev->dev_private;
97 struct drm_mm_node *compressed_fb, *uninitialized_var(compressed_llb);
99 /* Try to over-allocate to reduce reallocations and fragmentation */
100 compressed_fb = drm_mm_search_free(&dev_priv->mm.stolen,
101 size <<= 1, 4096, 0);
103 compressed_fb = drm_mm_search_free(&dev_priv->mm.stolen,
104 size >>= 1, 4096, 0);
106 compressed_fb = drm_mm_get_block(compressed_fb, size, 4096);
110 if (HAS_PCH_SPLIT(dev))
111 I915_WRITE(ILK_DPFC_CB_BASE, compressed_fb->start);
112 else if (IS_GM45(dev)) {
113 I915_WRITE(DPFC_CB_BASE, compressed_fb->start);
115 compressed_llb = drm_mm_search_free(&dev_priv->mm.stolen,
118 compressed_llb = drm_mm_get_block(compressed_llb,
123 dev_priv->compressed_llb = compressed_llb;
125 I915_WRITE(FBC_CFB_BASE,
126 dev_priv->mm.stolen_base + compressed_fb->start);
127 I915_WRITE(FBC_LL_BASE,
128 dev_priv->mm.stolen_base + compressed_llb->start);
131 dev_priv->compressed_fb = compressed_fb;
132 dev_priv->cfb_size = size;
134 DRM_DEBUG_KMS("reserved %d bytes of contiguous stolen space for FBC\n",
140 drm_mm_put_block(compressed_fb);
142 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);
146 int i915_gem_stolen_setup_compression(struct drm_device *dev, int size)
148 struct drm_i915_private *dev_priv = dev->dev_private;
150 if (dev_priv->mm.stolen_base == 0)
153 if (size < dev_priv->cfb_size)
156 /* Release any current block */
157 i915_gem_stolen_cleanup_compression(dev);
159 return i915_setup_compression(dev, size);
162 void i915_gem_stolen_cleanup_compression(struct drm_device *dev)
164 struct drm_i915_private *dev_priv = dev->dev_private;
166 if (dev_priv->cfb_size == 0)
169 if (dev_priv->compressed_fb)
170 drm_mm_put_block(dev_priv->compressed_fb);
172 if (dev_priv->compressed_llb)
173 drm_mm_put_block(dev_priv->compressed_llb);
175 dev_priv->cfb_size = 0;
178 void i915_gem_cleanup_stolen(struct drm_device *dev)
180 struct drm_i915_private *dev_priv = dev->dev_private;
182 i915_gem_stolen_cleanup_compression(dev);
183 drm_mm_takedown(&dev_priv->mm.stolen);
186 int i915_gem_init_stolen(struct drm_device *dev)
188 struct drm_i915_private *dev_priv = dev->dev_private;
189 int bios_reserved = 0;
191 dev_priv->mm.stolen_base = i915_stolen_to_physical(dev);
192 if (dev_priv->mm.stolen_base == 0)
195 DRM_DEBUG_KMS("found %zd bytes of stolen memory at %08lx\n",
196 dev_priv->gtt.stolen_size, dev_priv->mm.stolen_base);
198 if (IS_VALLEYVIEW(dev))
199 bios_reserved = 1024*1024; /* top 1M on VLV/BYT */
201 /* Basic memrange allocator for stolen space */
202 drm_mm_init(&dev_priv->mm.stolen, 0, dev_priv->gtt.stolen_size -
208 static struct sg_table *
209 i915_pages_create_for_stolen(struct drm_device *dev,
210 u32 offset, u32 size)
212 struct drm_i915_private *dev_priv = dev->dev_private;
214 struct scatterlist *sg;
216 DRM_DEBUG_DRIVER("offset=0x%x, size=%d\n", offset, size);
217 BUG_ON(offset > dev_priv->gtt.stolen_size - size);
219 /* We hide that we have no struct page backing our stolen object
220 * by wrapping the contiguous physical allocation with a fake
221 * dma mapping in a single scatterlist.
224 st = kmalloc(sizeof(*st), GFP_KERNEL);
228 if (sg_alloc_table(st, 1, GFP_KERNEL)) {
237 sg_dma_address(sg) = (dma_addr_t)dev_priv->mm.stolen_base + offset;
238 sg_dma_len(sg) = size;
243 static int i915_gem_object_get_pages_stolen(struct drm_i915_gem_object *obj)
249 static void i915_gem_object_put_pages_stolen(struct drm_i915_gem_object *obj)
251 /* Should only be called during free */
252 sg_free_table(obj->pages);
256 static const struct drm_i915_gem_object_ops i915_gem_object_stolen_ops = {
257 .get_pages = i915_gem_object_get_pages_stolen,
258 .put_pages = i915_gem_object_put_pages_stolen,
261 static struct drm_i915_gem_object *
262 _i915_gem_object_create_stolen(struct drm_device *dev,
263 struct drm_mm_node *stolen)
265 struct drm_i915_gem_object *obj;
267 obj = i915_gem_object_alloc(dev);
271 if (drm_gem_private_object_init(dev, &obj->base, stolen->size))
274 i915_gem_object_init(obj, &i915_gem_object_stolen_ops);
276 obj->pages = i915_pages_create_for_stolen(dev,
277 stolen->start, stolen->size);
278 if (obj->pages == NULL)
281 obj->has_dma_mapping = true;
282 i915_gem_object_pin_pages(obj);
283 obj->stolen = stolen;
285 obj->base.write_domain = I915_GEM_DOMAIN_GTT;
286 obj->base.read_domains = I915_GEM_DOMAIN_GTT;
287 obj->cache_level = I915_CACHE_NONE;
292 i915_gem_object_free(obj);
296 struct drm_i915_gem_object *
297 i915_gem_object_create_stolen(struct drm_device *dev, u32 size)
299 struct drm_i915_private *dev_priv = dev->dev_private;
300 struct drm_i915_gem_object *obj;
301 struct drm_mm_node *stolen;
303 if (dev_priv->mm.stolen_base == 0)
306 DRM_DEBUG_KMS("creating stolen object: size=%x\n", size);
310 stolen = drm_mm_search_free(&dev_priv->mm.stolen, size, 4096, 0);
312 stolen = drm_mm_get_block(stolen, size, 4096);
316 obj = _i915_gem_object_create_stolen(dev, stolen);
320 drm_mm_put_block(stolen);
324 struct drm_i915_gem_object *
325 i915_gem_object_create_stolen_for_preallocated(struct drm_device *dev,
330 struct drm_i915_private *dev_priv = dev->dev_private;
331 struct drm_i915_gem_object *obj;
332 struct drm_mm_node *stolen;
334 if (dev_priv->mm.stolen_base == 0)
337 DRM_DEBUG_KMS("creating preallocated stolen object: stolen_offset=%x, gtt_offset=%x, size=%x\n",
338 stolen_offset, gtt_offset, size);
340 /* KISS and expect everything to be page-aligned */
341 BUG_ON(stolen_offset & 4095);
344 if (WARN_ON(size == 0))
347 stolen = drm_mm_create_block(&dev_priv->mm.stolen,
350 if (stolen == NULL) {
351 DRM_DEBUG_KMS("failed to allocate stolen space\n");
355 obj = _i915_gem_object_create_stolen(dev, stolen);
357 DRM_DEBUG_KMS("failed to allocate stolen object\n");
358 drm_mm_put_block(stolen);
362 /* Some objects just need physical mem from stolen space */
363 if (gtt_offset == -1)
366 /* To simplify the initialisation sequence between KMS and GTT,
367 * we allow construction of the stolen object prior to
368 * setting up the GTT space. The actual reservation will occur
371 if (drm_mm_initialized(&dev_priv->mm.gtt_space)) {
372 obj->gtt_space = drm_mm_create_block(&dev_priv->mm.gtt_space,
375 if (obj->gtt_space == NULL) {
376 DRM_DEBUG_KMS("failed to allocate stolen GTT space\n");
377 drm_gem_object_unreference(&obj->base);
381 obj->gtt_space = I915_GTT_RESERVED;
383 obj->gtt_offset = gtt_offset;
384 obj->has_global_gtt_mapping = 1;
386 list_add_tail(&obj->gtt_list, &dev_priv->mm.bound_list);
387 list_add_tail(&obj->mm_list, &dev_priv->mm.inactive_list);
393 i915_gem_object_release_stolen(struct drm_i915_gem_object *obj)
396 drm_mm_put_block(obj->stolen);