1 /* SPDX-License-Identifier: MIT */
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26 #ifndef __I915_VMA_TYPES_H__
27 #define __I915_VMA_TYPES_H__
29 #include <linux/rbtree.h>
31 #include <drm/drm_mm.h>
33 #include "gem/i915_gem_object_types.h"
35 enum i915_cache_level;
38 * DOC: Global GTT views
40 * Background and previous state
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.
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.
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
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:
64 * In this example both the size and layout of pages in the alternative view is
65 * different from the normal view.
67 * Implementation and usage
69 * GGTT views are implemented using VMAs and are distinguished via enum
70 * i915_ggtt_view_type and struct i915_ggtt_view.
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_ggtt_view
75 * parameter encapsulating all metadata required to implement a view.
77 * As a helper for callers which are only interested in the normal view,
78 * globally const i915_ggtt_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.
82 * Code wanting to add or use a new GGTT view needs to:
84 * 1. Add a new enum with a suitable name.
85 * 2. Extend the metadata in the i915_ggtt_view structure if required.
86 * 3. Add support to i915_get_vma_pages().
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.ggtt_view and
90 * exists for the lifetime of an VMA.
92 * Core API is designed to have copy semantics which means that passed in
93 * struct i915_ggtt_view does not need to be persistent (left around after
94 * calling the core API functions).
98 struct intel_remapped_plane_info {
103 /* in gtt pages for !linear */
111 /* in gtt pages for linear */
116 struct intel_remapped_info {
117 struct intel_remapped_plane_info plane[4];
122 struct intel_rotation_info {
123 struct intel_remapped_plane_info plane[2];
126 struct intel_partial_info {
131 enum i915_ggtt_view_type {
132 I915_GGTT_VIEW_NORMAL = 0,
133 I915_GGTT_VIEW_ROTATED = sizeof(struct intel_rotation_info),
134 I915_GGTT_VIEW_PARTIAL = sizeof(struct intel_partial_info),
135 I915_GGTT_VIEW_REMAPPED = sizeof(struct intel_remapped_info),
138 static inline void assert_i915_gem_gtt_types(void)
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));
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]));
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.
153 switch ((enum i915_ggtt_view_type)0) {
154 case I915_GGTT_VIEW_NORMAL:
155 case I915_GGTT_VIEW_PARTIAL:
156 case I915_GGTT_VIEW_ROTATED:
157 case I915_GGTT_VIEW_REMAPPED:
158 /* gcc complains if these are identical cases */
163 struct i915_ggtt_view {
164 enum i915_ggtt_view_type type;
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;
174 * DOC: Virtual Memory Address
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.
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.
184 struct drm_mm_node node;
186 struct i915_address_space *vm;
187 const struct i915_vma_ops *ops;
189 struct drm_i915_gem_object *obj;
191 struct sg_table *pages;
193 void *private; /* owned by creator */
195 struct i915_fence_reg *fence;
198 u64 display_alignment;
199 struct i915_page_sizes page_sizes;
201 /* mmap-offset associated with fencing for this vma */
202 struct i915_mmap_offset *mmo;
208 * Count of the number of times this vma has been opened by different
209 * handles (but same file) for execbuf, i.e. the number of aliases
210 * that exist in the ctx->handle_vmas LUT for this vma.
216 * How many users have pinned this object in GTT space.
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
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
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.
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
238 #define I915_VMA_PIN_MASK 0x3ff
239 #define I915_VMA_OVERFLOW 0x200
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
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))
248 #define I915_VMA_BIND_MASK (I915_VMA_GLOBAL_BIND | I915_VMA_LOCAL_BIND)
250 #define I915_VMA_ALLOC_BIT 12
252 #define I915_VMA_ERROR_BIT 13
253 #define I915_VMA_ERROR ((int)BIT(I915_VMA_ERROR_BIT))
255 #define I915_VMA_GGTT_BIT 14
256 #define I915_VMA_CAN_FENCE_BIT 15
257 #define I915_VMA_USERFAULT_BIT 16
258 #define I915_VMA_GGTT_WRITE_BIT 17
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))
265 #define I915_VMA_SCANOUT_BIT 18
266 #define I915_VMA_SCANOUT ((int)BIT(I915_VMA_SCANOUT_BIT))
268 struct i915_active active;
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 */
275 * Support different GGTT views into the same object.
276 * This means there can be multiple VMA mappings per object and per VM.
277 * i915_ggtt_view_type is used to distinguish between those entries.
278 * The default one of zero (I915_GGTT_VIEW_NORMAL) is default and also
279 * assumed in GEM functions which take no ggtt view parameter.
281 struct i915_ggtt_view ggtt_view;
283 /** This object's place on the active/inactive lists */
284 struct list_head vm_link;
286 struct list_head obj_link; /* Link in the object's VMA list */
287 struct rb_node obj_node;
288 struct hlist_node obj_hash;
290 /** This vma's place in the eviction list */
291 struct list_head evict_link;
293 struct list_head closed_link;