i915_gem_stolen.c revision 277487 
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 277487 2015-01-21 16:10:37Z kib $");
31
32#include <dev/drm2/drmP.h>
33#include <dev/drm2/drm.h>
34#include <dev/drm2/i915/i915_drm.h>
35#include <dev/drm2/i915/i915_drv.h>
36
37/*
38 * The BIOS typically reserves some of the system's memory for the exclusive
39 * use of the integrated graphics. This memory is no longer available for
40 * use by the OS and so the user finds that his system has less memory
41 * available than he put in. We refer to this memory as stolen.
42 *
43 * The BIOS will allocate its framebuffer from the stolen memory. Our
44 * goal is try to reuse that object for our own fbcon which must always
45 * be available for panics. Anything else we can reuse the stolen memory
46 * for is a boon.
47 */
48
49#define PTE_ADDRESS_MASK		0xfffff000
50#define PTE_ADDRESS_MASK_HIGH		0x000000f0 /* i915+ */
51#define PTE_MAPPING_TYPE_UNCACHED	(0 << 1)
52#define PTE_MAPPING_TYPE_DCACHE		(1 << 1) /* i830 only */
53#define PTE_MAPPING_TYPE_CACHED		(3 << 1)
54#define PTE_MAPPING_TYPE_MASK		(3 << 1)
55#define PTE_VALID			(1 << 0)
56
57/**
58 * i915_stolen_to_phys - take an offset into stolen memory and turn it into
59 *                       a physical one
60 * @dev: drm device
61 * @offset: address to translate
62 *
63 * Some chip functions require allocations from stolen space and need the
64 * physical address of the memory in question.
65 */
66static unsigned long i915_stolen_to_phys(struct drm_device *dev, u32 offset)
67{
68	struct drm_i915_private *dev_priv = dev->dev_private;
69	device_t pdev = dev_priv->bridge_dev;
70	u32 base;
71
72#if 0
73	/* On the machines I have tested the Graphics Base of Stolen Memory
74	 * is unreliable, so compute the base by subtracting the stolen memory
75	 * from the Top of Low Usable DRAM which is where the BIOS places
76	 * the graphics stolen memory.
77	 */
78	if (INTEL_INFO(dev)->gen > 3 || IS_G33(dev)) {
79		/* top 32bits are reserved = 0 */
80		pci_read_config_dword(pdev, 0xA4, &base);
81	} else {
82		/* XXX presume 8xx is the same as i915 */
83		pci_bus_read_config_dword(pdev->bus, 2, 0x5C, &base);
84	}
85#else
86	if (INTEL_INFO(dev)->gen > 3 || IS_G33(dev)) {
87		u16 val;
88		val = pci_read_config(pdev, 0xb0, 2);
89		base = val >> 4 << 20;
90	} else {
91		u8 val;
92		val = pci_read_config(pdev, 0x9c, 1);
93		base = val >> 3 << 27;
94	}
95	base -= dev_priv->mm.gtt.stolen_size;
96#endif
97
98	return base + offset;
99}
100
101static void i915_warn_stolen(struct drm_device *dev)
102{
103	DRM_INFO("not enough stolen space for compressed buffer, disabling\n");
104	DRM_INFO("hint: you may be able to increase stolen memory size in the BIOS to avoid this\n");
105}
106
107static void i915_setup_compression(struct drm_device *dev, int size)
108{
109	struct drm_i915_private *dev_priv = dev->dev_private;
110	struct drm_mm_node *compressed_fb, *compressed_llb;
111	unsigned long cfb_base;
112	unsigned long ll_base = 0;
113
114	/* Just in case the BIOS is doing something questionable. */
115	intel_disable_fbc(dev);
116
117	compressed_fb = drm_mm_search_free(&dev_priv->mm.stolen, size, 4096, 0);
118	if (compressed_fb)
119		compressed_fb = drm_mm_get_block(compressed_fb, size, 4096);
120	if (!compressed_fb)
121		goto err;
122
123	cfb_base = i915_stolen_to_phys(dev, compressed_fb->start);
124	if (!cfb_base)
125		goto err_fb;
126
127	if (!(IS_GM45(dev) || HAS_PCH_SPLIT(dev))) {
128		compressed_llb = drm_mm_search_free(&dev_priv->mm.stolen,
129						    4096, 4096, 0);
130		if (compressed_llb)
131			compressed_llb = drm_mm_get_block(compressed_llb,
132							  4096, 4096);
133		if (!compressed_llb)
134			goto err_fb;
135
136		ll_base = i915_stolen_to_phys(dev, compressed_llb->start);
137		if (!ll_base)
138			goto err_llb;
139	}
140
141	dev_priv->cfb_size = size;
142
143	dev_priv->compressed_fb = compressed_fb;
144	if (HAS_PCH_SPLIT(dev))
145		I915_WRITE(ILK_DPFC_CB_BASE, compressed_fb->start);
146	else if (IS_GM45(dev)) {
147		I915_WRITE(DPFC_CB_BASE, compressed_fb->start);
148	} else {
149		I915_WRITE(FBC_CFB_BASE, cfb_base);
150		I915_WRITE(FBC_LL_BASE, ll_base);
151		dev_priv->compressed_llb = compressed_llb;
152	}
153
154	DRM_DEBUG_KMS("FBC base 0x%08lx, ll base 0x%08lx, size %dM\n",
155		      cfb_base, ll_base, size >> 20);
156	return;
157
158err_llb:
159	drm_mm_put_block(compressed_llb);
160err_fb:
161	drm_mm_put_block(compressed_fb);
162err:
163	dev_priv->no_fbc_reason = FBC_STOLEN_TOO_SMALL;
164	i915_warn_stolen(dev);
165}
166
167static void i915_cleanup_compression(struct drm_device *dev)
168{
169	struct drm_i915_private *dev_priv = dev->dev_private;
170
171	drm_mm_put_block(dev_priv->compressed_fb);
172	if (dev_priv->compressed_llb)
173		drm_mm_put_block(dev_priv->compressed_llb);
174}
175
176void i915_gem_cleanup_stolen(struct drm_device *dev)
177{
178	if (I915_HAS_FBC(dev) && i915_powersave)
179		i915_cleanup_compression(dev);
180}
181
182int i915_gem_init_stolen(struct drm_device *dev)
183{
184	struct drm_i915_private *dev_priv = dev->dev_private;
185	unsigned long prealloc_size = dev_priv->mm.gtt.stolen_size;
186
187	/* Basic memrange allocator for stolen space */
188	drm_mm_init(&dev_priv->mm.stolen, 0, prealloc_size);
189
190	/* Try to set up FBC with a reasonable compressed buffer size */
191	if (I915_HAS_FBC(dev) && i915_powersave) {
192		int cfb_size;
193
194		/* Leave 1M for line length buffer & misc. */
195
196		/* Try to get a 32M buffer... */
197		if (prealloc_size > (36*1024*1024))
198			cfb_size = 32*1024*1024;
199		else /* fall back to 7/8 of the stolen space */
200			cfb_size = prealloc_size * 7 / 8;
201		i915_setup_compression(dev, cfb_size);
202	}
203
204	return 0;
205}
206