xref: /linux/drivers/gpu/drm/i915/i915_vma_types.h (revision 79790b6818e96c58fe2bffee1b418c16e64e7b80)
1 /* SPDX-License-Identifier: MIT */
2 /*
3  * Copyright © 2016 Intel Corporation
4  *
5  * Permission is hereby granted, free of charge, to any person obtaining a
6  * copy of this software and associated documentation files (the "Software"),
7  * to deal in the Software without restriction, including without limitation
8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9  * and/or sell copies of the Software, and to permit persons to whom the
10  * Software is furnished to do so, subject to the following conditions:
11  *
12  * The above copyright notice and this permission notice (including the next
13  * paragraph) shall be included in all copies or substantial portions of the
14  * Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
21  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
22  * IN THE SOFTWARE.
23  *
24  */
25 
26 #ifndef __I915_VMA_TYPES_H__
27 #define __I915_VMA_TYPES_H__
28 
29 #include <linux/rbtree.h>
30 
31 #include <drm/drm_mm.h>
32 
33 #include "gem/i915_gem_object_types.h"
34 
35 /**
36  * DOC: Global GTT views
37  *
38  * Background and previous state
39  *
40  * Historically objects could exists (be bound) in global GTT space only as
41  * singular instances with a view representing all of the object's backing pages
42  * in a linear fashion. This view will be called a normal view.
43  *
44  * To support multiple views of the same object, where the number of mapped
45  * pages is not equal to the backing store, or where the layout of the pages
46  * is not linear, concept of a GGTT view was added.
47  *
48  * One example of an alternative view is a stereo display driven by a single
49  * image. In this case we would have a framebuffer looking like this
50  * (2x2 pages):
51  *
52  *    12
53  *    34
54  *
55  * Above would represent a normal GGTT view as normally mapped for GPU or CPU
56  * rendering. In contrast, fed to the display engine would be an alternative
57  * view which could look something like this:
58  *
59  *   1212
60  *   3434
61  *
62  * In this example both the size and layout of pages in the alternative view is
63  * different from the normal view.
64  *
65  * Implementation and usage
66  *
67  * GGTT views are implemented using VMAs and are distinguished via enum
68  * i915_gtt_view_type and struct i915_gtt_view.
69  *
70  * A new flavour of core GEM functions which work with GGTT bound objects were
71  * added with the _ggtt_ infix, and sometimes with _view postfix to avoid
72  * renaming  in large amounts of code. They take the struct i915_gtt_view
73  * parameter encapsulating all metadata required to implement a view.
74  *
75  * As a helper for callers which are only interested in the normal view,
76  * globally const i915_gtt_view_normal singleton instance exists. All old core
77  * GEM API functions, the ones not taking the view parameter, are operating on,
78  * or with the normal GGTT view.
79  *
80  * Code wanting to add or use a new GGTT view needs to:
81  *
82  * 1. Add a new enum with a suitable name.
83  * 2. Extend the metadata in the i915_gtt_view structure if required.
84  * 3. Add support to i915_get_vma_pages().
85  *
86  * New views are required to build a scatter-gather table from within the
87  * i915_get_vma_pages function. This table is stored in the vma.gtt_view and
88  * exists for the lifetime of an VMA.
89  *
90  * Core API is designed to have copy semantics which means that passed in
91  * struct i915_gtt_view does not need to be persistent (left around after
92  * calling the core API functions).
93  *
94  */
95 
96 struct i915_vma_resource;
97 
98 struct intel_remapped_plane_info {
99 	/* in gtt pages */
100 	u32 offset:31;
101 	u32 linear:1;
102 	union {
103 		/* in gtt pages for !linear */
104 		struct {
105 			u16 width;
106 			u16 height;
107 			u16 src_stride;
108 			u16 dst_stride;
109 		};
110 
111 		/* in gtt pages for linear */
112 		u32 size;
113 	};
114 } __packed;
115 
116 struct intel_remapped_info {
117 	struct intel_remapped_plane_info plane[4];
118 	/* in gtt pages */
119 	u32 plane_alignment;
120 } __packed;
121 
122 struct intel_rotation_info {
123 	struct intel_remapped_plane_info plane[2];
124 } __packed;
125 
126 struct intel_partial_info {
127 	u64 offset;
128 	unsigned int size;
129 } __packed;
130 
131 enum i915_gtt_view_type {
132 	I915_GTT_VIEW_NORMAL = 0,
133 	I915_GTT_VIEW_ROTATED = sizeof(struct intel_rotation_info),
134 	I915_GTT_VIEW_PARTIAL = sizeof(struct intel_partial_info),
135 	I915_GTT_VIEW_REMAPPED = sizeof(struct intel_remapped_info),
136 };
137 
assert_i915_gem_gtt_types(void)138 static inline void assert_i915_gem_gtt_types(void)
139 {
140 	BUILD_BUG_ON(sizeof(struct intel_rotation_info) != 2 * sizeof(u32) + 8 * sizeof(u16));
141 	BUILD_BUG_ON(sizeof(struct intel_partial_info) != sizeof(u64) + sizeof(unsigned int));
142 	BUILD_BUG_ON(sizeof(struct intel_remapped_info) != 5 * sizeof(u32) + 16 * sizeof(u16));
143 
144 	/* Check that rotation/remapped shares offsets for simplicity */
145 	BUILD_BUG_ON(offsetof(struct intel_remapped_info, plane[0]) !=
146 		     offsetof(struct intel_rotation_info, plane[0]));
147 	BUILD_BUG_ON(offsetofend(struct intel_remapped_info, plane[1]) !=
148 		     offsetofend(struct intel_rotation_info, plane[1]));
149 
150 	/* As we encode the size of each branch inside the union into its type,
151 	 * we have to be careful that each branch has a unique size.
152 	 */
153 	switch ((enum i915_gtt_view_type)0) {
154 	case I915_GTT_VIEW_NORMAL:
155 	case I915_GTT_VIEW_PARTIAL:
156 	case I915_GTT_VIEW_ROTATED:
157 	case I915_GTT_VIEW_REMAPPED:
158 		/* gcc complains if these are identical cases */
159 		break;
160 	}
161 }
162 
163 struct i915_gtt_view {
164 	enum i915_gtt_view_type type;
165 	union {
166 		/* Members need to contain no holes/padding */
167 		struct intel_partial_info partial;
168 		struct intel_rotation_info rotated;
169 		struct intel_remapped_info remapped;
170 	};
171 };
172 
173 /**
174  * DOC: Virtual Memory Address
175  *
176  * A VMA represents a GEM BO that is bound into an address space. Therefore, a
177  * VMA's presence cannot be guaranteed before binding, or after unbinding the
178  * object into/from the address space.
179  *
180  * To make things as simple as possible (ie. no refcounting), a VMA's lifetime
181  * will always be <= an objects lifetime. So object refcounting should cover us.
182  */
183 struct i915_vma {
184 	struct drm_mm_node node;
185 
186 	struct i915_address_space *vm;
187 	const struct i915_vma_ops *ops;
188 
189 	struct drm_i915_gem_object *obj;
190 
191 	struct sg_table *pages;
192 	void __iomem *iomap;
193 	void *private; /* owned by creator */
194 
195 	struct i915_fence_reg *fence;
196 
197 	u64 size;
198 	struct i915_page_sizes page_sizes;
199 
200 	/* mmap-offset associated with fencing for this vma */
201 	struct i915_mmap_offset	*mmo;
202 
203 	u32 guard; /* padding allocated around vma->pages within the node */
204 	u32 fence_size;
205 	u32 fence_alignment;
206 	u32 display_alignment;
207 
208 	/**
209 	 * Count of the number of times this vma has been opened by different
210 	 * handles (but same file) for execbuf, i.e. the number of aliases
211 	 * that exist in the ctx->handle_vmas LUT for this vma.
212 	 */
213 	atomic_t open_count;
214 	atomic_t flags;
215 	/**
216 	 * How many users have pinned this object in GTT space.
217 	 *
218 	 * This is a tightly bound, fairly small number of users, so we
219 	 * stuff inside the flags field so that we can both check for overflow
220 	 * and detect a no-op i915_vma_pin() in a single check, while also
221 	 * pinning the vma.
222 	 *
223 	 * The worst case display setup would have the same vma pinned for
224 	 * use on each plane on each crtc, while also building the next atomic
225 	 * state and holding a pin for the length of the cleanup queue. In the
226 	 * future, the flip queue may be increased from 1.
227 	 * Estimated worst case: 3 [qlen] * 4 [max crtcs] * 7 [max planes] = 84
228 	 *
229 	 * For GEM, the number of concurrent users for pwrite/pread is
230 	 * unbounded. For execbuffer, it is currently one but will in future
231 	 * be extended to allow multiple clients to pin vma concurrently.
232 	 *
233 	 * We also use suballocated pages, with each suballocation claiming
234 	 * its own pin on the shared vma. At present, this is limited to
235 	 * exclusive cachelines of a single page, so a maximum of 64 possible
236 	 * users.
237 	 */
238 #define I915_VMA_PIN_MASK 0x3ff
239 #define I915_VMA_OVERFLOW 0x200
240 
241 	/** Flags and address space this VMA is bound to */
242 #define I915_VMA_GLOBAL_BIND_BIT 10
243 #define I915_VMA_LOCAL_BIND_BIT  11
244 
245 #define I915_VMA_GLOBAL_BIND	((int)BIT(I915_VMA_GLOBAL_BIND_BIT))
246 #define I915_VMA_LOCAL_BIND	((int)BIT(I915_VMA_LOCAL_BIND_BIT))
247 
248 #define I915_VMA_BIND_MASK (I915_VMA_GLOBAL_BIND | I915_VMA_LOCAL_BIND)
249 
250 #define I915_VMA_ERROR_BIT	12
251 #define I915_VMA_ERROR		((int)BIT(I915_VMA_ERROR_BIT))
252 
253 #define I915_VMA_GGTT_BIT	13
254 #define I915_VMA_CAN_FENCE_BIT	14
255 #define I915_VMA_USERFAULT_BIT	15
256 #define I915_VMA_GGTT_WRITE_BIT	16
257 
258 #define I915_VMA_GGTT		((int)BIT(I915_VMA_GGTT_BIT))
259 #define I915_VMA_CAN_FENCE	((int)BIT(I915_VMA_CAN_FENCE_BIT))
260 #define I915_VMA_USERFAULT	((int)BIT(I915_VMA_USERFAULT_BIT))
261 #define I915_VMA_GGTT_WRITE	((int)BIT(I915_VMA_GGTT_WRITE_BIT))
262 
263 #define I915_VMA_SCANOUT_BIT	17
264 #define I915_VMA_SCANOUT	((int)BIT(I915_VMA_SCANOUT_BIT))
265 
266 	struct i915_active active;
267 
268 #define I915_VMA_PAGES_BIAS 24
269 #define I915_VMA_PAGES_ACTIVE (BIT(24) | 1)
270 	atomic_t pages_count; /* number of active binds to the pages */
271 
272 	/**
273 	 * Whether we hold a reference on the vm dma_resv lock to temporarily
274 	 * block vm freeing until the vma is destroyed.
275 	 * Protected by the vm mutex.
276 	 */
277 	bool vm_ddestroy;
278 
279 	/**
280 	 * Support different GGTT views into the same object.
281 	 * This means there can be multiple VMA mappings per object and per VM.
282 	 * i915_gtt_view_type is used to distinguish between those entries.
283 	 * The default one of zero (I915_GTT_VIEW_NORMAL) is default and also
284 	 * assumed in GEM functions which take no ggtt view parameter.
285 	 */
286 	struct i915_gtt_view gtt_view;
287 
288 	/** This object's place on the active/inactive lists */
289 	struct list_head vm_link;
290 
291 	struct list_head obj_link; /* Link in the object's VMA list */
292 	struct rb_node obj_node;
293 
294 	/** This vma's place in the eviction list */
295 	struct list_head evict_link;
296 
297 	struct list_head closed_link;
298 
299 	/** The async vma resource. Protected by the vm_mutex */
300 	struct i915_vma_resource *resource;
301 };
302 
303 #endif
304