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
);
139 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
);
143 int i915_gem_stolen_setup_compression(struct drm_device
*dev
, int size
)
145 struct drm_i915_private
*dev_priv
= dev
->dev_private
;
147 if (dev_priv
->mm
.stolen_base
== 0)
150 if (size
< dev_priv
->cfb_size
)
153 /* Release any current block */
154 i915_gem_stolen_cleanup_compression(dev
);
156 return i915_setup_compression(dev
, size
);
159 void i915_gem_stolen_cleanup_compression(struct drm_device
*dev
)
161 struct drm_i915_private
*dev_priv
= dev
->dev_private
;
163 if (dev_priv
->cfb_size
== 0)
166 if (dev_priv
->compressed_fb
)
167 drm_mm_put_block(dev_priv
->compressed_fb
);
169 if (dev_priv
->compressed_llb
)
170 drm_mm_put_block(dev_priv
->compressed_llb
);
172 dev_priv
->cfb_size
= 0;
175 void i915_gem_cleanup_stolen(struct drm_device
*dev
)
177 struct drm_i915_private
*dev_priv
= dev
->dev_private
;
179 i915_gem_stolen_cleanup_compression(dev
);
180 drm_mm_takedown(&dev_priv
->mm
.stolen
);
183 int i915_gem_init_stolen(struct drm_device
*dev
)
185 struct drm_i915_private
*dev_priv
= dev
->dev_private
;
187 dev_priv
->mm
.stolen_base
= i915_stolen_to_physical(dev
);
188 if (dev_priv
->mm
.stolen_base
== 0)
191 DRM_DEBUG_KMS("found %zd bytes of stolen memory at %08lx\n",
192 dev_priv
->gtt
.stolen_size
, dev_priv
->mm
.stolen_base
);
194 /* Basic memrange allocator for stolen space */
195 drm_mm_init(&dev_priv
->mm
.stolen
, 0, dev_priv
->gtt
.stolen_size
);
200 static struct sg_table
*
201 i915_pages_create_for_stolen(struct drm_device
*dev
,
202 u32 offset
, u32 size
)
204 struct drm_i915_private
*dev_priv
= dev
->dev_private
;
206 struct scatterlist
*sg
;
208 DRM_DEBUG_DRIVER("offset=0x%x, size=%d\n", offset
, size
);
209 BUG_ON(offset
> dev_priv
->gtt
.stolen_size
- size
);
211 /* We hide that we have no struct page backing our stolen object
212 * by wrapping the contiguous physical allocation with a fake
213 * dma mapping in a single scatterlist.
216 st
= kmalloc(sizeof(*st
), GFP_KERNEL
);
220 if (sg_alloc_table(st
, 1, GFP_KERNEL
)) {
229 sg_dma_address(sg
) = (dma_addr_t
)dev_priv
->mm
.stolen_base
+ offset
;
230 sg_dma_len(sg
) = size
;
235 static int i915_gem_object_get_pages_stolen(struct drm_i915_gem_object
*obj
)
241 static void i915_gem_object_put_pages_stolen(struct drm_i915_gem_object
*obj
)
243 /* Should only be called during free */
244 sg_free_table(obj
->pages
);
248 static const struct drm_i915_gem_object_ops i915_gem_object_stolen_ops
= {
249 .get_pages
= i915_gem_object_get_pages_stolen
,
250 .put_pages
= i915_gem_object_put_pages_stolen
,
253 static struct drm_i915_gem_object
*
254 _i915_gem_object_create_stolen(struct drm_device
*dev
,
255 struct drm_mm_node
*stolen
)
257 struct drm_i915_gem_object
*obj
;
259 obj
= i915_gem_object_alloc(dev
);
263 if (drm_gem_private_object_init(dev
, &obj
->base
, stolen
->size
))
266 i915_gem_object_init(obj
, &i915_gem_object_stolen_ops
);
268 obj
->pages
= i915_pages_create_for_stolen(dev
,
269 stolen
->start
, stolen
->size
);
270 if (obj
->pages
== NULL
)
273 obj
->has_dma_mapping
= true;
274 obj
->pages_pin_count
= 1;
275 obj
->stolen
= stolen
;
277 obj
->base
.write_domain
= I915_GEM_DOMAIN_GTT
;
278 obj
->base
.read_domains
= I915_GEM_DOMAIN_GTT
;
279 obj
->cache_level
= I915_CACHE_NONE
;
284 i915_gem_object_free(obj
);
288 struct drm_i915_gem_object
*
289 i915_gem_object_create_stolen(struct drm_device
*dev
, u32 size
)
291 struct drm_i915_private
*dev_priv
= dev
->dev_private
;
292 struct drm_i915_gem_object
*obj
;
293 struct drm_mm_node
*stolen
;
295 if (dev_priv
->mm
.stolen_base
== 0)
298 DRM_DEBUG_KMS("creating stolen object: size=%x\n", size
);
302 stolen
= drm_mm_search_free(&dev_priv
->mm
.stolen
, size
, 4096, 0);
304 stolen
= drm_mm_get_block(stolen
, size
, 4096);
308 obj
= _i915_gem_object_create_stolen(dev
, stolen
);
312 drm_mm_put_block(stolen
);
316 struct drm_i915_gem_object
*
317 i915_gem_object_create_stolen_for_preallocated(struct drm_device
*dev
,
322 struct drm_i915_private
*dev_priv
= dev
->dev_private
;
323 struct drm_i915_gem_object
*obj
;
324 struct drm_mm_node
*stolen
;
326 if (dev_priv
->mm
.stolen_base
== 0)
329 DRM_DEBUG_KMS("creating preallocated stolen object: stolen_offset=%x, gtt_offset=%x, size=%x\n",
330 stolen_offset
, gtt_offset
, size
);
332 /* KISS and expect everything to be page-aligned */
333 BUG_ON(stolen_offset
& 4095);
334 BUG_ON(gtt_offset
& 4095);
337 if (WARN_ON(size
== 0))
340 stolen
= drm_mm_create_block(&dev_priv
->mm
.stolen
,
343 if (stolen
== NULL
) {
344 DRM_DEBUG_KMS("failed to allocate stolen space\n");
348 obj
= _i915_gem_object_create_stolen(dev
, stolen
);
350 DRM_DEBUG_KMS("failed to allocate stolen object\n");
351 drm_mm_put_block(stolen
);
355 /* To simplify the initialisation sequence between KMS and GTT,
356 * we allow construction of the stolen object prior to
357 * setting up the GTT space. The actual reservation will occur
360 if (drm_mm_initialized(&dev_priv
->mm
.gtt_space
)) {
361 obj
->gtt_space
= drm_mm_create_block(&dev_priv
->mm
.gtt_space
,
364 if (obj
->gtt_space
== NULL
) {
365 DRM_DEBUG_KMS("failed to allocate stolen GTT space\n");
366 drm_gem_object_unreference(&obj
->base
);
370 obj
->gtt_space
= I915_GTT_RESERVED
;
372 obj
->gtt_offset
= gtt_offset
;
373 obj
->has_global_gtt_mapping
= 1;
375 list_add_tail(&obj
->gtt_list
, &dev_priv
->mm
.bound_list
);
376 list_add_tail(&obj
->mm_list
, &dev_priv
->mm
.inactive_list
);
382 i915_gem_object_release_stolen(struct drm_i915_gem_object
*obj
)
385 drm_mm_put_block(obj
->stolen
);