i915_gem_stolen.c revision 296548 
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 <sys/cdefs.h>
30__FBSDID("$FreeBSD: head/sys/dev/drm2/i915/i915_gem_stolen.c 296548 2016-03-08 20:33:02Z dumbbell $");
31
32#include <dev/drm2/drmP.h>
33#include <dev/drm2/i915/i915_drm.h>
34#include <dev/drm2/i915/i915_drv.h>
35
36/*
37 * The BIOS typically reserves some of the system's memory for the exclusive
38 * use of the integrated graphics. This memory is no longer available for
39 * use by the OS and so the user finds that his system has less memory
40 * available than he put in. We refer to this memory as stolen.
41 *
42 * The BIOS will allocate its framebuffer from the stolen memory. Our
43 * goal is try to reuse that object for our own fbcon which must always
44 * be available for panics. Anything else we can reuse the stolen memory
45 * for is a boon.
46 */
47
48static unsigned long i915_stolen_to_physical(struct drm_device *dev)
49{
50	u32 base;
51
52	/* On the machines I have tested the Graphics Base of Stolen Memory
53	 * is unreliable, so on those compute the base by subtracting the
54	 * stolen memory from the Top of Low Usable DRAM which is where the
55	 * BIOS places the graphics stolen memory.
56	 *
57	 * On gen2, the layout is slightly different with the Graphics Segment
58	 * immediately following Top of Memory (or Top of Usable DRAM). Note
59	 * it appears that TOUD is only reported by 865g, so we just use the
60	 * top of memory as determined by the e820 probe.
61	 *
62	 * XXX gen2 requires an unavailable symbol and 945gm fails with
63	 * its value of TOLUD.
64	 */
65	base = 0;
66	if (INTEL_INFO(dev)->gen >= 6) {
67		/* Read Base Data of Stolen Memory Register (BDSM) directly.
68		 * Note that there is also a MCHBAR miror at 0x1080c0 or
69		 * we could use device 2:0x5c instead.
70		*/
71		pci_read_config_dword(dev->dev, 0xB0, &base);
72		base &= ~4095; /* lower bits used for locking register */
73	} else if (INTEL_INFO(dev)->gen > 3 || IS_G33(dev)) {
74		/* Read Graphics Base of Stolen Memory directly */
75		pci_read_config_dword(dev->dev, 0xA4, &base);
76#if 0
77	} else if (IS_GEN3(dev)) {
78		u8 val;
79		/* Stolen is immediately below Top of Low Usable DRAM */
80		pci_read_config_byte(pdev, 0x9c, &val);
81		base = val >> 3 << 27;
82		base -= dev_priv->mm.gtt->stolen_size;
83	} else {
84		/* Stolen is immediately above Top of Memory */
85		base = max_low_pfn_mapped << PAGE_SHIFT;
86#endif
87	}
88
89	return base;
90}
91
92static void i915_warn_stolen(struct drm_device *dev)
93{
94	DRM_INFO("not enough stolen space for compressed buffer, disabling\n");
95	DRM_INFO("hint: you may be able to increase stolen memory size in the BIOS to avoid this\n");
96}
97
98static void i915_setup_compression(struct drm_device *dev, int size)
99{
100	struct drm_i915_private *dev_priv = dev->dev_private;
101	struct drm_mm_node *compressed_fb, *uninitialized_var(compressed_llb);
102	unsigned long cfb_base;
103	unsigned long ll_base = 0;
104
105	/* Just in case the BIOS is doing something questionable. */
106	intel_disable_fbc(dev);
107
108	compressed_fb = drm_mm_search_free(&dev_priv->mm.stolen, size, 4096, 0);
109	if (compressed_fb)
110		compressed_fb = drm_mm_get_block(compressed_fb, size, 4096);
111	if (!compressed_fb)
112		goto err;
113
114	cfb_base = dev_priv->mm.stolen_base + compressed_fb->start;
115	if (!cfb_base)
116		goto err_fb;
117
118	if (!(IS_GM45(dev) || HAS_PCH_SPLIT(dev))) {
119		compressed_llb = drm_mm_search_free(&dev_priv->mm.stolen,
120						    4096, 4096, 0);
121		if (compressed_llb)
122			compressed_llb = drm_mm_get_block(compressed_llb,
123							  4096, 4096);
124		if (!compressed_llb)
125			goto err_fb;
126
127		ll_base = dev_priv->mm.stolen_base + compressed_llb->start;
128		if (!ll_base)
129			goto err_llb;
130	}
131
132	dev_priv->cfb_size = size;
133
134	dev_priv->compressed_fb = compressed_fb;
135	if (HAS_PCH_SPLIT(dev))
136		I915_WRITE(ILK_DPFC_CB_BASE, compressed_fb->start);
137	else if (IS_GM45(dev)) {
138		I915_WRITE(DPFC_CB_BASE, compressed_fb->start);
139	} else {
140		I915_WRITE(FBC_CFB_BASE, cfb_base);
141		I915_WRITE(FBC_LL_BASE, ll_base);
142		dev_priv->compressed_llb = compressed_llb;
143	}
144
145	DRM_DEBUG_KMS("FBC base 0x%08lx, ll base 0x%08lx, size %dM\n",
146		      (long)cfb_base, (long)ll_base, size >> 20);
147	return;
148
149err_llb:
150	drm_mm_put_block(compressed_llb);
151err_fb:
152	drm_mm_put_block(compressed_fb);
153err:
154	dev_priv->no_fbc_reason = FBC_STOLEN_TOO_SMALL;
155	i915_warn_stolen(dev);
156}
157
158static void i915_cleanup_compression(struct drm_device *dev)
159{
160	struct drm_i915_private *dev_priv = dev->dev_private;
161
162	drm_mm_put_block(dev_priv->compressed_fb);
163	if (dev_priv->compressed_llb)
164		drm_mm_put_block(dev_priv->compressed_llb);
165}
166
167void i915_gem_cleanup_stolen(struct drm_device *dev)
168{
169	if (I915_HAS_FBC(dev) && i915_powersave)
170		i915_cleanup_compression(dev);
171}
172
173int i915_gem_init_stolen(struct drm_device *dev)
174{
175	struct drm_i915_private *dev_priv = dev->dev_private;
176	unsigned long prealloc_size = dev_priv->mm.gtt->stolen_size;
177
178	dev_priv->mm.stolen_base = i915_stolen_to_physical(dev);
179	if (dev_priv->mm.stolen_base == 0)
180		return 0;
181
182	DRM_DEBUG_KMS("found %d bytes of stolen memory at %08lx\n",
183		      dev_priv->mm.gtt->stolen_size, dev_priv->mm.stolen_base);
184
185	/* Basic memrange allocator for stolen space */
186	drm_mm_init(&dev_priv->mm.stolen, 0, prealloc_size);
187
188	/* Try to set up FBC with a reasonable compressed buffer size */
189	if (I915_HAS_FBC(dev) && i915_powersave) {
190		int cfb_size;
191
192		/* Leave 1M for line length buffer & misc. */
193
194		/* Try to get a 32M buffer... */
195		if (prealloc_size > (36*1024*1024))
196			cfb_size = 32*1024*1024;
197		else /* fall back to 7/8 of the stolen space */
198			cfb_size = prealloc_size * 7 / 8;
199		i915_setup_compression(dev, cfb_size);
200	}
201
202	return 0;
203}
204