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 enum i915_cache_level;
36
37 /**
38 * DOC: Global GTT views
39 *
40 * Background and previous state
41 *
42 * Historically objects could exists (be bound) in global GTT space only as
43 * singular instances with a view representing all of the object's backing pages
44 * in a linear fashion. This view will be called a normal view.
45 *
46 * To support multiple views of the same object, where the number of mapped
47 * pages is not equal to the backing store, or where the layout of the pages
48 * is not linear, concept of a GGTT view was added.
49 *
50 * One example of an alternative view is a stereo display driven by a single
51 * image. In this case we would have a framebuffer looking like this
52 * (2x2 pages):
53 *
54 * 12
55 * 34
56 *
57 * Above would represent a normal GGTT view as normally mapped for GPU or CPU
58 * rendering. In contrast, fed to the display engine would be an alternative
59 * view which could look something like this:
60 *
61 * 1212
62 * 3434
63 *
64 * In this example both the size and layout of pages in the alternative view is
65 * different from the normal view.
66 *
67 * Implementation and usage
68 *
69 * GGTT views are implemented using VMAs and are distinguished via enum
70 * i915_gtt_view_type and struct i915_gtt_view.
71 *
72 * A new flavour of core GEM functions which work with GGTT bound objects were
73 * added with the _ggtt_ infix, and sometimes with _view postfix to avoid
74 * renaming in large amounts of code. They take the struct i915_gtt_view
75 * parameter encapsulating all metadata required to implement a view.
76 *
77 * As a helper for callers which are only interested in the normal view,
78 * globally const i915_gtt_view_normal singleton instance exists. All old core
79 * GEM API functions, the ones not taking the view parameter, are operating on,
80 * or with the normal GGTT view.
81 *
82 * Code wanting to add or use a new GGTT view needs to:
83 *
84 * 1. Add a new enum with a suitable name.
85 * 2. Extend the metadata in the i915_gtt_view structure if required.
86 * 3. Add support to i915_get_vma_pages().
87 *
88 * New views are required to build a scatter-gather table from within the
89 * i915_get_vma_pages function. This table is stored in the vma.gtt_view and
90 * exists for the lifetime of an VMA.
91 *
92 * Core API is designed to have copy semantics which means that passed in
93 * struct i915_gtt_view does not need to be persistent (left around after
94 * calling the core API functions).
95 *
96 */
97
98 struct i915_vma_resource;
99
100 struct intel_remapped_plane_info {
101 /* in gtt pages */
102 u32 offset:31;
103 u32 linear:1;
104 union {
105 /* in gtt pages for !linear */
106 struct {
107 u16 width;
108 u16 height;
109 u16 src_stride;
110 u16 dst_stride;
111 };
112
113 /* in gtt pages for linear */
114 u32 size;
115 };
116 } __packed;
117
118 struct intel_remapped_info {
119 struct intel_remapped_plane_info plane[4];
120 /* in gtt pages */
121 u32 plane_alignment;
122 } __packed;
123
124 struct intel_rotation_info {
125 struct intel_remapped_plane_info plane[2];
126 } __packed;
127
128 struct intel_partial_info {
129 u64 offset;
130 unsigned int size;
131 } __packed;
132
133 enum i915_gtt_view_type {
134 I915_GTT_VIEW_NORMAL = 0,
135 I915_GTT_VIEW_ROTATED = sizeof(struct intel_rotation_info),
136 I915_GTT_VIEW_PARTIAL = sizeof(struct intel_partial_info),
137 I915_GTT_VIEW_REMAPPED = sizeof(struct intel_remapped_info),
138 };
139
assert_i915_gem_gtt_types(void)140 static inline void assert_i915_gem_gtt_types(void)
141 {
142 BUILD_BUG_ON(sizeof(struct intel_rotation_info) != 2 * sizeof(u32) + 8 * sizeof(u16));
143 BUILD_BUG_ON(sizeof(struct intel_partial_info) != sizeof(u64) + sizeof(unsigned int));
144 BUILD_BUG_ON(sizeof(struct intel_remapped_info) != 5 * sizeof(u32) + 16 * sizeof(u16));
145
146 /* Check that rotation/remapped shares offsets for simplicity */
147 BUILD_BUG_ON(offsetof(struct intel_remapped_info, plane[0]) !=
148 offsetof(struct intel_rotation_info, plane[0]));
149 BUILD_BUG_ON(offsetofend(struct intel_remapped_info, plane[1]) !=
150 offsetofend(struct intel_rotation_info, plane[1]));
151
152 /* As we encode the size of each branch inside the union into its type,
153 * we have to be careful that each branch has a unique size.
154 */
155 switch ((enum i915_gtt_view_type)0) {
156 case I915_GTT_VIEW_NORMAL:
157 case I915_GTT_VIEW_PARTIAL:
158 case I915_GTT_VIEW_ROTATED:
159 case I915_GTT_VIEW_REMAPPED:
160 /* gcc complains if these are identical cases */
161 break;
162 }
163 }
164
165 struct i915_gtt_view {
166 enum i915_gtt_view_type type;
167 union {
168 /* Members need to contain no holes/padding */
169 struct intel_partial_info partial;
170 struct intel_rotation_info rotated;
171 struct intel_remapped_info remapped;
172 };
173 };
174
175 /**
176 * DOC: Virtual Memory Address
177 *
178 * A VMA represents a GEM BO that is bound into an address space. Therefore, a
179 * VMA's presence cannot be guaranteed before binding, or after unbinding the
180 * object into/from the address space.
181 *
182 * To make things as simple as possible (ie. no refcounting), a VMA's lifetime
183 * will always be <= an objects lifetime. So object refcounting should cover us.
184 */
185 struct i915_vma {
186 struct drm_mm_node node;
187
188 struct i915_address_space *vm;
189 const struct i915_vma_ops *ops;
190
191 struct drm_i915_gem_object *obj;
192
193 struct sg_table *pages;
194 void __iomem *iomap;
195 void *private; /* owned by creator */
196
197 struct i915_fence_reg *fence;
198
199 u64 size;
200 struct i915_page_sizes page_sizes;
201
202 /* mmap-offset associated with fencing for this vma */
203 struct i915_mmap_offset *mmo;
204
205 u32 guard; /* padding allocated around vma->pages within the node */
206 u32 fence_size;
207 u32 fence_alignment;
208 u32 display_alignment;
209
210 /**
211 * Count of the number of times this vma has been opened by different
212 * handles (but same file) for execbuf, i.e. the number of aliases
213 * that exist in the ctx->handle_vmas LUT for this vma.
214 */
215 atomic_t open_count;
216 atomic_t flags;
217 /**
218 * How many users have pinned this object in GTT space.
219 *
220 * This is a tightly bound, fairly small number of users, so we
221 * stuff inside the flags field so that we can both check for overflow
222 * and detect a no-op i915_vma_pin() in a single check, while also
223 * pinning the vma.
224 *
225 * The worst case display setup would have the same vma pinned for
226 * use on each plane on each crtc, while also building the next atomic
227 * state and holding a pin for the length of the cleanup queue. In the
228 * future, the flip queue may be increased from 1.
229 * Estimated worst case: 3 [qlen] * 4 [max crtcs] * 7 [max planes] = 84
230 *
231 * For GEM, the number of concurrent users for pwrite/pread is
232 * unbounded. For execbuffer, it is currently one but will in future
233 * be extended to allow multiple clients to pin vma concurrently.
234 *
235 * We also use suballocated pages, with each suballocation claiming
236 * its own pin on the shared vma. At present, this is limited to
237 * exclusive cachelines of a single page, so a maximum of 64 possible
238 * users.
239 */
240 #define I915_VMA_PIN_MASK 0x3ff
241 #define I915_VMA_OVERFLOW 0x200
242
243 /** Flags and address space this VMA is bound to */
244 #define I915_VMA_GLOBAL_BIND_BIT 10
245 #define I915_VMA_LOCAL_BIND_BIT 11
246
247 #define I915_VMA_GLOBAL_BIND ((int)BIT(I915_VMA_GLOBAL_BIND_BIT))
248 #define I915_VMA_LOCAL_BIND ((int)BIT(I915_VMA_LOCAL_BIND_BIT))
249
250 #define I915_VMA_BIND_MASK (I915_VMA_GLOBAL_BIND | I915_VMA_LOCAL_BIND)
251
252 #define I915_VMA_ERROR_BIT 12
253 #define I915_VMA_ERROR ((int)BIT(I915_VMA_ERROR_BIT))
254
255 #define I915_VMA_GGTT_BIT 13
256 #define I915_VMA_CAN_FENCE_BIT 14
257 #define I915_VMA_USERFAULT_BIT 15
258 #define I915_VMA_GGTT_WRITE_BIT 16
259
260 #define I915_VMA_GGTT ((int)BIT(I915_VMA_GGTT_BIT))
261 #define I915_VMA_CAN_FENCE ((int)BIT(I915_VMA_CAN_FENCE_BIT))
262 #define I915_VMA_USERFAULT ((int)BIT(I915_VMA_USERFAULT_BIT))
263 #define I915_VMA_GGTT_WRITE ((int)BIT(I915_VMA_GGTT_WRITE_BIT))
264
265 #define I915_VMA_SCANOUT_BIT 17
266 #define I915_VMA_SCANOUT ((int)BIT(I915_VMA_SCANOUT_BIT))
267
268 struct i915_active active;
269
270 #define I915_VMA_PAGES_BIAS 24
271 #define I915_VMA_PAGES_ACTIVE (BIT(24) | 1)
272 atomic_t pages_count; /* number of active binds to the pages */
273
274 /**
275 * Whether we hold a reference on the vm dma_resv lock to temporarily
276 * block vm freeing until the vma is destroyed.
277 * Protected by the vm mutex.
278 */
279 bool vm_ddestroy;
280
281 /**
282 * Support different GGTT views into the same object.
283 * This means there can be multiple VMA mappings per object and per VM.
284 * i915_gtt_view_type is used to distinguish between those entries.
285 * The default one of zero (I915_GTT_VIEW_NORMAL) is default and also
286 * assumed in GEM functions which take no ggtt view parameter.
287 */
288 struct i915_gtt_view gtt_view;
289
290 /** This object's place on the active/inactive lists */
291 struct list_head vm_link;
292
293 struct list_head obj_link; /* Link in the object's VMA list */
294 struct rb_node obj_node;
295 struct hlist_node obj_hash;
296
297 /** This vma's place in the eviction list */
298 struct list_head evict_link;
299
300 struct list_head closed_link;
301
302 /** The async vma resource. Protected by the vm_mutex */
303 struct i915_vma_resource *resource;
304 };
305
306 #endif
307