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_ggtt_view_type and struct i915_ggtt_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_ggtt_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_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. 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_ggtt_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.ggtt_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_ggtt_view does not need to be persistent (left around after 94 * calling the core API functions). 95 * 96 */ 97 98 struct intel_remapped_plane_info { 99 /* in gtt pages */ 100 unsigned int width, height, stride, offset; 101 } __packed; 102 103 struct intel_remapped_info { 104 struct intel_remapped_plane_info plane[2]; 105 unsigned int unused_mbz; 106 } __packed; 107 108 struct intel_rotation_info { 109 struct intel_remapped_plane_info plane[2]; 110 } __packed; 111 112 struct intel_partial_info { 113 u64 offset; 114 unsigned int size; 115 } __packed; 116 117 enum i915_ggtt_view_type { 118 I915_GGTT_VIEW_NORMAL = 0, 119 I915_GGTT_VIEW_ROTATED = sizeof(struct intel_rotation_info), 120 I915_GGTT_VIEW_PARTIAL = sizeof(struct intel_partial_info), 121 I915_GGTT_VIEW_REMAPPED = sizeof(struct intel_remapped_info), 122 }; 123 124 static inline void assert_i915_gem_gtt_types(void) 125 { 126 BUILD_BUG_ON(sizeof(struct intel_rotation_info) != 8*sizeof(unsigned int)); 127 BUILD_BUG_ON(sizeof(struct intel_partial_info) != sizeof(u64) + sizeof(unsigned int)); 128 BUILD_BUG_ON(sizeof(struct intel_remapped_info) != 9*sizeof(unsigned int)); 129 130 /* Check that rotation/remapped shares offsets for simplicity */ 131 BUILD_BUG_ON(offsetof(struct intel_remapped_info, plane[0]) != 132 offsetof(struct intel_rotation_info, plane[0])); 133 BUILD_BUG_ON(offsetofend(struct intel_remapped_info, plane[1]) != 134 offsetofend(struct intel_rotation_info, plane[1])); 135 136 /* As we encode the size of each branch inside the union into its type, 137 * we have to be careful that each branch has a unique size. 138 */ 139 switch ((enum i915_ggtt_view_type)0) { 140 case I915_GGTT_VIEW_NORMAL: 141 case I915_GGTT_VIEW_PARTIAL: 142 case I915_GGTT_VIEW_ROTATED: 143 case I915_GGTT_VIEW_REMAPPED: 144 /* gcc complains if these are identical cases */ 145 break; 146 } 147 } 148 149 struct i915_ggtt_view { 150 enum i915_ggtt_view_type type; 151 union { 152 /* Members need to contain no holes/padding */ 153 struct intel_partial_info partial; 154 struct intel_rotation_info rotated; 155 struct intel_remapped_info remapped; 156 }; 157 }; 158 159 /** 160 * DOC: Virtual Memory Address 161 * 162 * A VMA represents a GEM BO that is bound into an address space. Therefore, a 163 * VMA's presence cannot be guaranteed before binding, or after unbinding the 164 * object into/from the address space. 165 * 166 * To make things as simple as possible (ie. no refcounting), a VMA's lifetime 167 * will always be <= an objects lifetime. So object refcounting should cover us. 168 */ 169 struct i915_vma { 170 struct drm_mm_node node; 171 172 struct i915_address_space *vm; 173 const struct i915_vma_ops *ops; 174 175 struct drm_i915_gem_object *obj; 176 struct dma_resv *resv; /** Alias of obj->resv */ 177 178 struct sg_table *pages; 179 void __iomem *iomap; 180 void *private; /* owned by creator */ 181 182 struct i915_fence_reg *fence; 183 184 u64 size; 185 u64 display_alignment; 186 struct i915_page_sizes page_sizes; 187 188 /* mmap-offset associated with fencing for this vma */ 189 struct i915_mmap_offset *mmo; 190 191 u32 fence_size; 192 u32 fence_alignment; 193 194 /** 195 * Count of the number of times this vma has been opened by different 196 * handles (but same file) for execbuf, i.e. the number of aliases 197 * that exist in the ctx->handle_vmas LUT for this vma. 198 */ 199 struct kref ref; 200 atomic_t open_count; 201 atomic_t flags; 202 /** 203 * How many users have pinned this object in GTT space. 204 * 205 * This is a tightly bound, fairly small number of users, so we 206 * stuff inside the flags field so that we can both check for overflow 207 * and detect a no-op i915_vma_pin() in a single check, while also 208 * pinning the vma. 209 * 210 * The worst case display setup would have the same vma pinned for 211 * use on each plane on each crtc, while also building the next atomic 212 * state and holding a pin for the length of the cleanup queue. In the 213 * future, the flip queue may be increased from 1. 214 * Estimated worst case: 3 [qlen] * 4 [max crtcs] * 7 [max planes] = 84 215 * 216 * For GEM, the number of concurrent users for pwrite/pread is 217 * unbounded. For execbuffer, it is currently one but will in future 218 * be extended to allow multiple clients to pin vma concurrently. 219 * 220 * We also use suballocated pages, with each suballocation claiming 221 * its own pin on the shared vma. At present, this is limited to 222 * exclusive cachelines of a single page, so a maximum of 64 possible 223 * users. 224 */ 225 #define I915_VMA_PIN_MASK 0x3ff 226 #define I915_VMA_OVERFLOW 0x200 227 228 /** Flags and address space this VMA is bound to */ 229 #define I915_VMA_GLOBAL_BIND_BIT 10 230 #define I915_VMA_LOCAL_BIND_BIT 11 231 232 #define I915_VMA_GLOBAL_BIND ((int)BIT(I915_VMA_GLOBAL_BIND_BIT)) 233 #define I915_VMA_LOCAL_BIND ((int)BIT(I915_VMA_LOCAL_BIND_BIT)) 234 235 #define I915_VMA_BIND_MASK (I915_VMA_GLOBAL_BIND | I915_VMA_LOCAL_BIND) 236 237 #define I915_VMA_ALLOC_BIT 12 238 #define I915_VMA_ALLOC ((int)BIT(I915_VMA_ALLOC_BIT)) 239 240 #define I915_VMA_ERROR_BIT 13 241 #define I915_VMA_ERROR ((int)BIT(I915_VMA_ERROR_BIT)) 242 243 #define I915_VMA_GGTT_BIT 14 244 #define I915_VMA_CAN_FENCE_BIT 15 245 #define I915_VMA_USERFAULT_BIT 16 246 #define I915_VMA_GGTT_WRITE_BIT 17 247 248 #define I915_VMA_GGTT ((int)BIT(I915_VMA_GGTT_BIT)) 249 #define I915_VMA_CAN_FENCE ((int)BIT(I915_VMA_CAN_FENCE_BIT)) 250 #define I915_VMA_USERFAULT ((int)BIT(I915_VMA_USERFAULT_BIT)) 251 #define I915_VMA_GGTT_WRITE ((int)BIT(I915_VMA_GGTT_WRITE_BIT)) 252 253 struct i915_active active; 254 255 #define I915_VMA_PAGES_BIAS 24 256 #define I915_VMA_PAGES_ACTIVE (BIT(24) | 1) 257 atomic_t pages_count; /* number of active binds to the pages */ 258 struct mutex pages_mutex; /* protect acquire/release of backing pages */ 259 260 /** 261 * Support different GGTT views into the same object. 262 * This means there can be multiple VMA mappings per object and per VM. 263 * i915_ggtt_view_type is used to distinguish between those entries. 264 * The default one of zero (I915_GGTT_VIEW_NORMAL) is default and also 265 * assumed in GEM functions which take no ggtt view parameter. 266 */ 267 struct i915_ggtt_view ggtt_view; 268 269 /** This object's place on the active/inactive lists */ 270 struct list_head vm_link; 271 272 struct list_head obj_link; /* Link in the object's VMA list */ 273 struct rb_node obj_node; 274 struct hlist_node obj_hash; 275 276 /** This vma's place in the eviction list */ 277 struct list_head evict_link; 278 279 struct list_head closed_link; 280 }; 281 282 #endif 283 284