xref: /linux/drivers/gpu/drm/i915/gem/i915_gem_object_types.h (revision 3a39d672e7f48b8d6b91a09afa4b55352773b4b5)
1 /*
2  * SPDX-License-Identifier: MIT
3  *
4  * Copyright © 2016 Intel Corporation
5  */
6 
7 #ifndef __I915_GEM_OBJECT_TYPES_H__
8 #define __I915_GEM_OBJECT_TYPES_H__
9 
10 #include <linux/mmu_notifier.h>
11 
12 #include <drm/drm_gem.h>
13 #include <drm/ttm/ttm_bo.h>
14 #include <uapi/drm/i915_drm.h>
15 
16 #include "i915_active.h"
17 #include "i915_selftest.h"
18 #include "i915_vma_resource.h"
19 
20 #include "gt/intel_gt_defines.h"
21 
22 struct drm_i915_gem_object;
23 struct intel_fronbuffer;
24 struct intel_memory_region;
25 
26 /*
27  * struct i915_lut_handle tracks the fast lookups from handle to vma used
28  * for execbuf. Although we use a radixtree for that mapping, in order to
29  * remove them as the object or context is closed, we need a secondary list
30  * and a translation entry (i915_lut_handle).
31  */
32 struct i915_lut_handle {
33 	struct list_head obj_link;
34 	struct i915_gem_context *ctx;
35 	u32 handle;
36 };
37 
38 struct drm_i915_gem_object_ops {
39 	unsigned int flags;
40 #define I915_GEM_OBJECT_IS_SHRINKABLE			BIT(1)
41 /* Skip the shrinker management in set_pages/unset_pages */
42 #define I915_GEM_OBJECT_SELF_MANAGED_SHRINK_LIST	BIT(2)
43 #define I915_GEM_OBJECT_IS_PROXY			BIT(3)
44 #define I915_GEM_OBJECT_NO_MMAP				BIT(4)
45 
46 	/* Interface between the GEM object and its backing storage.
47 	 * get_pages() is called once prior to the use of the associated set
48 	 * of pages before to binding them into the GTT, and put_pages() is
49 	 * called after we no longer need them. As we expect there to be
50 	 * associated cost with migrating pages between the backing storage
51 	 * and making them available for the GPU (e.g. clflush), we may hold
52 	 * onto the pages after they are no longer referenced by the GPU
53 	 * in case they may be used again shortly (for example migrating the
54 	 * pages to a different memory domain within the GTT). put_pages()
55 	 * will therefore most likely be called when the object itself is
56 	 * being released or under memory pressure (where we attempt to
57 	 * reap pages for the shrinker).
58 	 */
59 	int (*get_pages)(struct drm_i915_gem_object *obj);
60 	void (*put_pages)(struct drm_i915_gem_object *obj,
61 			  struct sg_table *pages);
62 	int (*truncate)(struct drm_i915_gem_object *obj);
63 	/**
64 	 * shrink - Perform further backend specific actions to facilate
65 	 * shrinking.
66 	 * @obj: The gem object
67 	 * @flags: Extra flags to control shrinking behaviour in the backend
68 	 *
69 	 * Possible values for @flags:
70 	 *
71 	 * I915_GEM_OBJECT_SHRINK_WRITEBACK - Try to perform writeback of the
72 	 * backing pages, if supported.
73 	 *
74 	 * I915_GEM_OBJECT_SHRINK_NO_GPU_WAIT - Don't wait for the object to
75 	 * idle.  Active objects can be considered later. The TTM backend for
76 	 * example might have aync migrations going on, which don't use any
77 	 * i915_vma to track the active GTT binding, and hence having an unbound
78 	 * object might not be enough.
79 	 */
80 #define I915_GEM_OBJECT_SHRINK_WRITEBACK   BIT(0)
81 #define I915_GEM_OBJECT_SHRINK_NO_GPU_WAIT BIT(1)
82 	int (*shrink)(struct drm_i915_gem_object *obj, unsigned int flags);
83 
84 	int (*pread)(struct drm_i915_gem_object *obj,
85 		     const struct drm_i915_gem_pread *arg);
86 	int (*pwrite)(struct drm_i915_gem_object *obj,
87 		      const struct drm_i915_gem_pwrite *arg);
88 	u64 (*mmap_offset)(struct drm_i915_gem_object *obj);
89 	void (*unmap_virtual)(struct drm_i915_gem_object *obj);
90 
91 	int (*dmabuf_export)(struct drm_i915_gem_object *obj);
92 
93 	/**
94 	 * adjust_lru - notify that the madvise value was updated
95 	 * @obj: The gem object
96 	 *
97 	 * The madvise value may have been updated, or object was recently
98 	 * referenced so act accordingly (Perhaps changing an LRU list etc).
99 	 */
100 	void (*adjust_lru)(struct drm_i915_gem_object *obj);
101 
102 	/**
103 	 * delayed_free - Override the default delayed free implementation
104 	 */
105 	void (*delayed_free)(struct drm_i915_gem_object *obj);
106 
107 	/**
108 	 * migrate - Migrate object to a different region either for
109 	 * pinning or for as long as the object lock is held.
110 	 */
111 	int (*migrate)(struct drm_i915_gem_object *obj,
112 		       struct intel_memory_region *mr,
113 		       unsigned int flags);
114 
115 	void (*release)(struct drm_i915_gem_object *obj);
116 
117 	const struct vm_operations_struct *mmap_ops;
118 	const char *name; /* friendly name for debug, e.g. lockdep classes */
119 };
120 
121 /**
122  * enum i915_cache_level - The supported GTT caching values for system memory
123  * pages.
124  *
125  * These translate to some special GTT PTE bits when binding pages into some
126  * address space. It also determines whether an object, or rather its pages are
127  * coherent with the GPU, when also reading or writing through the CPU cache
128  * with those pages.
129  *
130  * Userspace can also control this through struct drm_i915_gem_caching.
131  */
132 enum i915_cache_level {
133 	/**
134 	 * @I915_CACHE_NONE:
135 	 *
136 	 * GPU access is not coherent with the CPU cache. If the cache is dirty
137 	 * and we need the underlying pages to be coherent with some later GPU
138 	 * access then we need to manually flush the pages.
139 	 *
140 	 * On shared LLC platforms reads and writes through the CPU cache are
141 	 * still coherent even with this setting. See also
142 	 * &drm_i915_gem_object.cache_coherent for more details. Due to this we
143 	 * should only ever use uncached for scanout surfaces, otherwise we end
144 	 * up over-flushing in some places.
145 	 *
146 	 * This is the default on non-LLC platforms.
147 	 */
148 	I915_CACHE_NONE = 0,
149 	/**
150 	 * @I915_CACHE_LLC:
151 	 *
152 	 * GPU access is coherent with the CPU cache. If the cache is dirty,
153 	 * then the GPU will ensure that access remains coherent, when both
154 	 * reading and writing through the CPU cache. GPU writes can dirty the
155 	 * CPU cache.
156 	 *
157 	 * Not used for scanout surfaces.
158 	 *
159 	 * Applies to both platforms with shared LLC(HAS_LLC), and snooping
160 	 * based platforms(HAS_SNOOP).
161 	 *
162 	 * This is the default on shared LLC platforms.  The only exception is
163 	 * scanout objects, where the display engine is not coherent with the
164 	 * CPU cache. For such objects I915_CACHE_NONE or I915_CACHE_WT is
165 	 * automatically applied by the kernel in pin_for_display, if userspace
166 	 * has not done so already.
167 	 */
168 	I915_CACHE_LLC,
169 	/**
170 	 * @I915_CACHE_L3_LLC:
171 	 *
172 	 * Explicitly enable the Gfx L3 cache, with coherent LLC.
173 	 *
174 	 * The Gfx L3 sits between the domain specific caches, e.g
175 	 * sampler/render caches, and the larger LLC. LLC is coherent with the
176 	 * GPU, but L3 is only visible to the GPU, so likely needs to be flushed
177 	 * when the workload completes.
178 	 *
179 	 * Not used for scanout surfaces.
180 	 *
181 	 * Only exposed on some gen7 + GGTT. More recent hardware has dropped
182 	 * this explicit setting, where it should now be enabled by default.
183 	 */
184 	I915_CACHE_L3_LLC,
185 	/**
186 	 * @I915_CACHE_WT:
187 	 *
188 	 * Write-through. Used for scanout surfaces.
189 	 *
190 	 * The GPU can utilise the caches, while still having the display engine
191 	 * be coherent with GPU writes, as a result we don't need to flush the
192 	 * CPU caches when moving out of the render domain. This is the default
193 	 * setting chosen by the kernel, if supported by the HW, otherwise we
194 	 * fallback to I915_CACHE_NONE. On the CPU side writes through the CPU
195 	 * cache still need to be flushed, to remain coherent with the display
196 	 * engine.
197 	 */
198 	I915_CACHE_WT,
199 	/**
200 	 * @I915_MAX_CACHE_LEVEL:
201 	 *
202 	 * Mark the last entry in the enum. Used for defining cachelevel_to_pat
203 	 * array for cache_level to pat translation table.
204 	 */
205 	I915_MAX_CACHE_LEVEL,
206 };
207 
208 enum i915_map_type {
209 	I915_MAP_WB = 0,
210 	I915_MAP_WC,
211 #define I915_MAP_OVERRIDE BIT(31)
212 	I915_MAP_FORCE_WB = I915_MAP_WB | I915_MAP_OVERRIDE,
213 	I915_MAP_FORCE_WC = I915_MAP_WC | I915_MAP_OVERRIDE,
214 };
215 
216 enum i915_mmap_type {
217 	I915_MMAP_TYPE_GTT = 0,
218 	I915_MMAP_TYPE_WC,
219 	I915_MMAP_TYPE_WB,
220 	I915_MMAP_TYPE_UC,
221 	I915_MMAP_TYPE_FIXED,
222 };
223 
224 struct i915_mmap_offset {
225 	struct drm_vma_offset_node vma_node;
226 	struct drm_i915_gem_object *obj;
227 	enum i915_mmap_type mmap_type;
228 
229 	struct rb_node offset;
230 };
231 
232 struct i915_gem_object_page_iter {
233 	struct scatterlist *sg_pos;
234 	unsigned int sg_idx; /* in pages, but 32bit eek! */
235 
236 	struct radix_tree_root radix;
237 	struct mutex lock; /* protects this cache */
238 };
239 
240 struct drm_i915_gem_object {
241 	/*
242 	 * We might have reason to revisit the below since it wastes
243 	 * a lot of space for non-ttm gem objects.
244 	 * In any case, always use the accessors for the ttm_buffer_object
245 	 * when accessing it.
246 	 */
247 	union {
248 		struct drm_gem_object base;
249 		struct ttm_buffer_object __do_not_access;
250 	};
251 
252 	const struct drm_i915_gem_object_ops *ops;
253 
254 	struct {
255 		/**
256 		 * @vma.lock: protect the list/tree of vmas
257 		 */
258 		spinlock_t lock;
259 
260 		/**
261 		 * @vma.list: List of VMAs backed by this object
262 		 *
263 		 * The VMA on this list are ordered by type, all GGTT vma are
264 		 * placed at the head and all ppGTT vma are placed at the tail.
265 		 * The different types of GGTT vma are unordered between
266 		 * themselves, use the @vma.tree (which has a defined order
267 		 * between all VMA) to quickly find an exact match.
268 		 */
269 		struct list_head list;
270 
271 		/**
272 		 * @vma.tree: Ordered tree of VMAs backed by this object
273 		 *
274 		 * All VMA created for this object are placed in the @vma.tree
275 		 * for fast retrieval via a binary search in
276 		 * i915_vma_instance(). They are also added to @vma.list for
277 		 * easy iteration.
278 		 */
279 		struct rb_root tree;
280 	} vma;
281 
282 	/**
283 	 * @lut_list: List of vma lookup entries in use for this object.
284 	 *
285 	 * If this object is closed, we need to remove all of its VMA from
286 	 * the fast lookup index in associated contexts; @lut_list provides
287 	 * this translation from object to context->handles_vma.
288 	 */
289 	struct list_head lut_list;
290 	spinlock_t lut_lock; /* guards lut_list */
291 
292 	/**
293 	 * @obj_link: Link into @i915_gem_ww_ctx.obj_list
294 	 *
295 	 * When we lock this object through i915_gem_object_lock() with a
296 	 * context, we add it to the list to ensure we can unlock everything
297 	 * when i915_gem_ww_ctx_backoff() or i915_gem_ww_ctx_fini() are called.
298 	 */
299 	struct list_head obj_link;
300 	/**
301 	 * @shared_resv_from: The object shares the resv from this vm.
302 	 */
303 	struct i915_address_space *shares_resv_from;
304 
305 #ifdef CONFIG_PROC_FS
306 	/**
307 	 * @client: @i915_drm_client which created the object
308 	 */
309 	struct i915_drm_client *client;
310 
311 	/**
312 	 * @client_link: Link into @i915_drm_client.objects_list
313 	 */
314 	struct list_head client_link;
315 #endif
316 
317 	union {
318 		struct rcu_head rcu;
319 		struct llist_node freed;
320 	};
321 
322 	/**
323 	 * Whether the object is currently in the GGTT or any other supported
324 	 * fake offset mmap backed by lmem.
325 	 */
326 	unsigned int userfault_count;
327 	struct list_head userfault_link;
328 
329 	struct {
330 		spinlock_t lock; /* Protects access to mmo offsets */
331 		struct rb_root offsets;
332 	} mmo;
333 
334 	I915_SELFTEST_DECLARE(struct list_head st_link);
335 
336 	unsigned long flags;
337 #define I915_BO_ALLOC_CONTIGUOUS  BIT(0)
338 #define I915_BO_ALLOC_VOLATILE    BIT(1)
339 #define I915_BO_ALLOC_CPU_CLEAR   BIT(2)
340 #define I915_BO_ALLOC_USER        BIT(3)
341 /* Object is allowed to lose its contents on suspend / resume, even if pinned */
342 #define I915_BO_ALLOC_PM_VOLATILE BIT(4)
343 /* Object needs to be restored early using memcpy during resume */
344 #define I915_BO_ALLOC_PM_EARLY    BIT(5)
345 /*
346  * Object is likely never accessed by the CPU. This will prioritise the BO to be
347  * allocated in the non-mappable portion of lmem. This is merely a hint, and if
348  * dealing with userspace objects the CPU fault handler is free to ignore this.
349  */
350 #define I915_BO_ALLOC_GPU_ONLY	  BIT(6)
351 #define I915_BO_ALLOC_CCS_AUX	  BIT(7)
352 /*
353  * Object is allowed to retain its initial data and will not be cleared on first
354  * access if used along with I915_BO_ALLOC_USER. This is mainly to keep
355  * preallocated framebuffer data intact while transitioning it to i915drmfb.
356  */
357 #define I915_BO_PREALLOC	  BIT(8)
358 #define I915_BO_ALLOC_FLAGS (I915_BO_ALLOC_CONTIGUOUS | \
359 			     I915_BO_ALLOC_VOLATILE | \
360 			     I915_BO_ALLOC_CPU_CLEAR | \
361 			     I915_BO_ALLOC_USER | \
362 			     I915_BO_ALLOC_PM_VOLATILE | \
363 			     I915_BO_ALLOC_PM_EARLY | \
364 			     I915_BO_ALLOC_GPU_ONLY | \
365 			     I915_BO_ALLOC_CCS_AUX | \
366 			     I915_BO_PREALLOC)
367 #define I915_BO_READONLY          BIT(9)
368 #define I915_TILING_QUIRK_BIT     10 /* unknown swizzling; do not release! */
369 #define I915_BO_PROTECTED         BIT(11)
370 	/**
371 	 * @mem_flags - Mutable placement-related flags
372 	 *
373 	 * These are flags that indicate specifics of the memory region
374 	 * the object is currently in. As such they are only stable
375 	 * either under the object lock or if the object is pinned.
376 	 */
377 	unsigned int mem_flags;
378 #define I915_BO_FLAG_STRUCT_PAGE BIT(0) /* Object backed by struct pages */
379 #define I915_BO_FLAG_IOMEM       BIT(1) /* Object backed by IO memory */
380 	/**
381 	 * @pat_index: The desired PAT index.
382 	 *
383 	 * See hardware specification for valid PAT indices for each platform.
384 	 * This field replaces the @cache_level that contains a value of enum
385 	 * i915_cache_level since PAT indices are being used by both userspace
386 	 * and kernel mode driver for caching policy control after GEN12.
387 	 * In the meantime platform specific tables are created to translate
388 	 * i915_cache_level into pat index, for more details check the macros
389 	 * defined i915/i915_pci.c, e.g. TGL_CACHELEVEL.
390 	 * For backward compatibility, this field contains values exactly match
391 	 * the entries of enum i915_cache_level for pre-GEN12 platforms (See
392 	 * LEGACY_CACHELEVEL), so that the PTE encode functions for these
393 	 * legacy platforms can stay the same.
394 	 */
395 	unsigned int pat_index:6;
396 	/**
397 	 * @pat_set_by_user: Indicate whether pat_index is set by user space
398 	 *
399 	 * This field is set to false by default, only set to true if the
400 	 * pat_index is set by user space. By design, user space is capable of
401 	 * managing caching behavior by setting pat_index, in which case this
402 	 * kernel mode driver should never touch the pat_index.
403 	 */
404 	unsigned int pat_set_by_user:1;
405 	/**
406 	 * @cache_coherent:
407 	 *
408 	 * Note: with the change above which replaced @cache_level with pat_index,
409 	 * the use of @cache_coherent is limited to the objects created by kernel
410 	 * or by userspace without pat index specified.
411 	 * Check for @pat_set_by_user to find out if an object has pat index set
412 	 * by userspace. The ioctl's to change cache settings have also been
413 	 * disabled for the objects with pat index set by userspace. Please don't
414 	 * assume @cache_coherent having the flags set as describe here. A helper
415 	 * function i915_gem_object_has_cache_level() provides one way to bypass
416 	 * the use of this field.
417 	 *
418 	 * Track whether the pages are coherent with the GPU if reading or
419 	 * writing through the CPU caches. The largely depends on the
420 	 * @cache_level setting.
421 	 *
422 	 * On platforms which don't have the shared LLC(HAS_SNOOP), like on Atom
423 	 * platforms, coherency must be explicitly requested with some special
424 	 * GTT caching bits(see enum i915_cache_level). When enabling coherency
425 	 * it does come at a performance and power cost on such platforms. On
426 	 * the flip side the kernel does not need to manually flush any buffers
427 	 * which need to be coherent with the GPU, if the object is not coherent
428 	 * i.e @cache_coherent is zero.
429 	 *
430 	 * On platforms that share the LLC with the CPU(HAS_LLC), all GT memory
431 	 * access will automatically snoop the CPU caches(even with CACHE_NONE).
432 	 * The one exception is when dealing with the display engine, like with
433 	 * scanout surfaces. To handle this the kernel will always flush the
434 	 * surface out of the CPU caches when preparing it for scanout.  Also
435 	 * note that since scanout surfaces are only ever read by the display
436 	 * engine we only need to care about flushing any writes through the CPU
437 	 * cache, reads on the other hand will always be coherent.
438 	 *
439 	 * Something strange here is why @cache_coherent is not a simple
440 	 * boolean, i.e coherent vs non-coherent. The reasoning for this is back
441 	 * to the display engine not being fully coherent. As a result scanout
442 	 * surfaces will either be marked as I915_CACHE_NONE or I915_CACHE_WT.
443 	 * In the case of seeing I915_CACHE_NONE the kernel makes the assumption
444 	 * that this is likely a scanout surface, and will set @cache_coherent
445 	 * as only I915_BO_CACHE_COHERENT_FOR_READ, on platforms with the shared
446 	 * LLC. The kernel uses this to always flush writes through the CPU
447 	 * cache as early as possible, where it can, in effect keeping
448 	 * @cache_dirty clean, so we can potentially avoid stalling when
449 	 * flushing the surface just before doing the scanout.  This does mean
450 	 * we might unnecessarily flush non-scanout objects in some places, but
451 	 * the default assumption is that all normal objects should be using
452 	 * I915_CACHE_LLC, at least on platforms with the shared LLC.
453 	 *
454 	 * Supported values:
455 	 *
456 	 * I915_BO_CACHE_COHERENT_FOR_READ:
457 	 *
458 	 * On shared LLC platforms, we use this for special scanout surfaces,
459 	 * where the display engine is not coherent with the CPU cache. As such
460 	 * we need to ensure we flush any writes before doing the scanout. As an
461 	 * optimisation we try to flush any writes as early as possible to avoid
462 	 * stalling later.
463 	 *
464 	 * Thus for scanout surfaces using I915_CACHE_NONE, on shared LLC
465 	 * platforms, we use:
466 	 *
467 	 *	cache_coherent = I915_BO_CACHE_COHERENT_FOR_READ
468 	 *
469 	 * While for normal objects that are fully coherent, including special
470 	 * scanout surfaces marked as I915_CACHE_WT, we use:
471 	 *
472 	 *	cache_coherent = I915_BO_CACHE_COHERENT_FOR_READ |
473 	 *			 I915_BO_CACHE_COHERENT_FOR_WRITE
474 	 *
475 	 * And then for objects that are not coherent at all we use:
476 	 *
477 	 *	cache_coherent = 0
478 	 *
479 	 * I915_BO_CACHE_COHERENT_FOR_WRITE:
480 	 *
481 	 * When writing through the CPU cache, the GPU is still coherent. Note
482 	 * that this also implies I915_BO_CACHE_COHERENT_FOR_READ.
483 	 */
484 #define I915_BO_CACHE_COHERENT_FOR_READ BIT(0)
485 #define I915_BO_CACHE_COHERENT_FOR_WRITE BIT(1)
486 	unsigned int cache_coherent:2;
487 
488 	/**
489 	 * @cache_dirty:
490 	 *
491 	 * Note: with the change above which replaced cache_level with pat_index,
492 	 * the use of @cache_dirty is limited to the objects created by kernel
493 	 * or by userspace without pat index specified.
494 	 * Check for @pat_set_by_user to find out if an object has pat index set
495 	 * by userspace. The ioctl's to change cache settings have also been
496 	 * disabled for the objects with pat_index set by userspace. Please don't
497 	 * assume @cache_dirty is set as describe here. Also see helper function
498 	 * i915_gem_object_has_cache_level() for possible ways to bypass the use
499 	 * of this field.
500 	 *
501 	 * Track if we are we dirty with writes through the CPU cache for this
502 	 * object. As a result reading directly from main memory might yield
503 	 * stale data.
504 	 *
505 	 * This also ties into whether the kernel is tracking the object as
506 	 * coherent with the GPU, as per @cache_coherent, as it determines if
507 	 * flushing might be needed at various points.
508 	 *
509 	 * Another part of @cache_dirty is managing flushing when first
510 	 * acquiring the pages for system memory, at this point the pages are
511 	 * considered foreign, so the default assumption is that the cache is
512 	 * dirty, for example the page zeroing done by the kernel might leave
513 	 * writes though the CPU cache, or swapping-in, while the actual data in
514 	 * main memory is potentially stale.  Note that this is a potential
515 	 * security issue when dealing with userspace objects and zeroing. Now,
516 	 * whether we actually need apply the big sledgehammer of flushing all
517 	 * the pages on acquire depends on if @cache_coherent is marked as
518 	 * I915_BO_CACHE_COHERENT_FOR_WRITE, i.e that the GPU will be coherent
519 	 * for both reads and writes though the CPU cache.
520 	 *
521 	 * Note that on shared LLC platforms we still apply the heavy flush for
522 	 * I915_CACHE_NONE objects, under the assumption that this is going to
523 	 * be used for scanout.
524 	 *
525 	 * Update: On some hardware there is now also the 'Bypass LLC' MOCS
526 	 * entry, which defeats our @cache_coherent tracking, since userspace
527 	 * can freely bypass the CPU cache when touching the pages with the GPU,
528 	 * where the kernel is completely unaware. On such platform we need
529 	 * apply the sledgehammer-on-acquire regardless of the @cache_coherent.
530 	 *
531 	 * Special care is taken on non-LLC platforms, to prevent potential
532 	 * information leak. The driver currently ensures:
533 	 *
534 	 *   1. All userspace objects, by default, have @cache_level set as
535 	 *   I915_CACHE_NONE. The only exception is userptr objects, where we
536 	 *   instead force I915_CACHE_LLC, but we also don't allow userspace to
537 	 *   ever change the @cache_level for such objects. Another special case
538 	 *   is dma-buf, which doesn't rely on @cache_dirty, but there we
539 	 *   always do a forced flush when acquiring the pages, if there is a
540 	 *   chance that the pages can be read directly from main memory with
541 	 *   the GPU.
542 	 *
543 	 *   2. All I915_CACHE_NONE objects have @cache_dirty initially true.
544 	 *
545 	 *   3. All swapped-out objects(i.e shmem) have @cache_dirty set to
546 	 *   true.
547 	 *
548 	 *   4. The @cache_dirty is never freely reset before the initial
549 	 *   flush, even if userspace adjusts the @cache_level through the
550 	 *   i915_gem_set_caching_ioctl.
551 	 *
552 	 *   5. All @cache_dirty objects(including swapped-in) are initially
553 	 *   flushed with a synchronous call to drm_clflush_sg in
554 	 *   __i915_gem_object_set_pages. The @cache_dirty can be freely reset
555 	 *   at this point. All further asynchronous clfushes are never security
556 	 *   critical, i.e userspace is free to race against itself.
557 	 */
558 	unsigned int cache_dirty:1;
559 
560 	/* @is_dpt: Object houses a display page table (DPT) */
561 	unsigned int is_dpt:1;
562 
563 	/**
564 	 * @read_domains: Read memory domains.
565 	 *
566 	 * These monitor which caches contain read/write data related to the
567 	 * object. When transitioning from one set of domains to another,
568 	 * the driver is called to ensure that caches are suitably flushed and
569 	 * invalidated.
570 	 */
571 	u16 read_domains;
572 
573 	/**
574 	 * @write_domain: Corresponding unique write memory domain.
575 	 */
576 	u16 write_domain;
577 
578 	struct intel_frontbuffer __rcu *frontbuffer;
579 
580 	/** Current tiling stride for the object, if it's tiled. */
581 	unsigned int tiling_and_stride;
582 #define FENCE_MINIMUM_STRIDE 128 /* See i915_tiling_ok() */
583 #define TILING_MASK (FENCE_MINIMUM_STRIDE - 1)
584 #define STRIDE_MASK (~TILING_MASK)
585 
586 	struct {
587 		/*
588 		 * Protects the pages and their use. Do not use directly, but
589 		 * instead go through the pin/unpin interfaces.
590 		 */
591 		atomic_t pages_pin_count;
592 
593 		/**
594 		 * @shrink_pin: Prevents the pages from being made visible to
595 		 * the shrinker, while the shrink_pin is non-zero. Most users
596 		 * should pretty much never have to care about this, outside of
597 		 * some special use cases.
598 		 *
599 		 * By default most objects will start out as visible to the
600 		 * shrinker(if I915_GEM_OBJECT_IS_SHRINKABLE) as soon as the
601 		 * backing pages are attached to the object, like in
602 		 * __i915_gem_object_set_pages(). They will then be removed the
603 		 * shrinker list once the pages are released.
604 		 *
605 		 * The @shrink_pin is incremented by calling
606 		 * i915_gem_object_make_unshrinkable(), which will also remove
607 		 * the object from the shrinker list, if the pin count was zero.
608 		 *
609 		 * Callers will then typically call
610 		 * i915_gem_object_make_shrinkable() or
611 		 * i915_gem_object_make_purgeable() to decrement the pin count,
612 		 * and make the pages visible again.
613 		 */
614 		atomic_t shrink_pin;
615 
616 		/**
617 		 * @ttm_shrinkable: True when the object is using shmem pages
618 		 * underneath. Protected by the object lock.
619 		 */
620 		bool ttm_shrinkable;
621 
622 		/**
623 		 * @unknown_state: Indicate that the object is effectively
624 		 * borked. This is write-once and set if we somehow encounter a
625 		 * fatal error when moving/clearing the pages, and we are not
626 		 * able to fallback to memcpy/memset, like on small-BAR systems.
627 		 * The GPU should also be wedged (or in the process) at this
628 		 * point.
629 		 *
630 		 * Only valid to read this after acquiring the dma-resv lock and
631 		 * waiting for all DMA_RESV_USAGE_KERNEL fences to be signalled,
632 		 * or if we otherwise know that the moving fence has signalled,
633 		 * and we are certain the pages underneath are valid for
634 		 * immediate access (under normal operation), like just prior to
635 		 * binding the object or when setting up the CPU fault handler.
636 		 * See i915_gem_object_has_unknown_state();
637 		 */
638 		bool unknown_state;
639 
640 		/**
641 		 * Priority list of potential placements for this object.
642 		 */
643 		struct intel_memory_region **placements;
644 		int n_placements;
645 
646 		/**
647 		 * Memory region for this object.
648 		 */
649 		struct intel_memory_region *region;
650 
651 		/**
652 		 * Memory manager resource allocated for this object. Only
653 		 * needed for the mock region.
654 		 */
655 		struct ttm_resource *res;
656 
657 		/**
658 		 * Element within memory_region->objects or region->purgeable
659 		 * if the object is marked as DONTNEED. Access is protected by
660 		 * region->obj_lock.
661 		 */
662 		struct list_head region_link;
663 
664 		struct i915_refct_sgt *rsgt;
665 		struct sg_table *pages;
666 		void *mapping;
667 
668 		struct i915_page_sizes page_sizes;
669 
670 		I915_SELFTEST_DECLARE(unsigned int page_mask);
671 
672 		struct i915_gem_object_page_iter get_page;
673 		struct i915_gem_object_page_iter get_dma_page;
674 
675 		/**
676 		 * Element within i915->mm.shrink_list or i915->mm.purge_list,
677 		 * locked by i915->mm.obj_lock.
678 		 */
679 		struct list_head link;
680 
681 		/**
682 		 * Advice: are the backing pages purgeable?
683 		 */
684 		unsigned int madv:2;
685 
686 		/**
687 		 * This is set if the object has been written to since the
688 		 * pages were last acquired.
689 		 */
690 		bool dirty:1;
691 
692 		u32 tlb[I915_MAX_GT];
693 	} mm;
694 
695 	struct {
696 		struct i915_refct_sgt *cached_io_rsgt;
697 		struct i915_gem_object_page_iter get_io_page;
698 		struct drm_i915_gem_object *backup;
699 		bool created:1;
700 	} ttm;
701 
702 	/*
703 	 * Record which PXP key instance this object was created against (if
704 	 * any), so we can use it to determine if the encryption is valid by
705 	 * comparing against the current key instance.
706 	 */
707 	u32 pxp_key_instance;
708 
709 	/** Record of address bit 17 of each page at last unbind. */
710 	unsigned long *bit_17;
711 
712 	union {
713 #ifdef CONFIG_MMU_NOTIFIER
714 		struct i915_gem_userptr {
715 			uintptr_t ptr;
716 			unsigned long notifier_seq;
717 
718 			struct mmu_interval_notifier notifier;
719 			struct page **pvec;
720 			int page_ref;
721 		} userptr;
722 #endif
723 
724 		struct drm_mm_node *stolen;
725 
726 		resource_size_t bo_offset;
727 
728 		unsigned long scratch;
729 		u64 encode;
730 
731 		void *gvt_info;
732 	};
733 };
734 
735 #define intel_bo_to_drm_bo(bo) (&(bo)->base)
736 #define intel_bo_to_i915(bo) to_i915(intel_bo_to_drm_bo(bo)->dev)
737 
738 static inline struct drm_i915_gem_object *
to_intel_bo(struct drm_gem_object * gem)739 to_intel_bo(struct drm_gem_object *gem)
740 {
741 	/* Assert that to_intel_bo(NULL) == NULL */
742 	BUILD_BUG_ON(offsetof(struct drm_i915_gem_object, base));
743 
744 	return container_of(gem, struct drm_i915_gem_object, base);
745 }
746 
747 #endif
748