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   1/*
   2 * SPDX-License-Identifier: MIT
   3 *
   4 * Copyright © 2008,2010 Intel Corporation
   5 */
   6
   7#include <linux/intel-iommu.h>
   8#include <linux/dma-resv.h>
   9#include <linux/sync_file.h>
  10#include <linux/uaccess.h>
  11
  12#include <drm/drm_syncobj.h>
  13#include <drm/i915_drm.h>
  14
  15#include "display/intel_frontbuffer.h"
  16
  17#include "gem/i915_gem_ioctls.h"
  18#include "gt/intel_context.h"
  19#include "gt/intel_engine_pool.h"
  20#include "gt/intel_gt.h"
  21#include "gt/intel_gt_pm.h"
  22
  23#include "i915_drv.h"
  24#include "i915_gem_clflush.h"
  25#include "i915_gem_context.h"
  26#include "i915_gem_ioctls.h"
  27#include "i915_trace.h"
  28
  29enum {
  30	FORCE_CPU_RELOC = 1,
  31	FORCE_GTT_RELOC,
  32	FORCE_GPU_RELOC,
  33#define DBG_FORCE_RELOC 0 /* choose one of the above! */
  34};
  35
  36#define __EXEC_OBJECT_HAS_REF		BIT(31)
  37#define __EXEC_OBJECT_HAS_PIN		BIT(30)
  38#define __EXEC_OBJECT_HAS_FENCE		BIT(29)
  39#define __EXEC_OBJECT_NEEDS_MAP		BIT(28)
  40#define __EXEC_OBJECT_NEEDS_BIAS	BIT(27)
  41#define __EXEC_OBJECT_INTERNAL_FLAGS	(~0u << 27) /* all of the above */
  42#define __EXEC_OBJECT_RESERVED (__EXEC_OBJECT_HAS_PIN | __EXEC_OBJECT_HAS_FENCE)
  43
  44#define __EXEC_HAS_RELOC	BIT(31)
  45#define __EXEC_VALIDATED	BIT(30)
  46#define __EXEC_INTERNAL_FLAGS	(~0u << 30)
  47#define UPDATE			PIN_OFFSET_FIXED
  48
  49#define BATCH_OFFSET_BIAS (256*1024)
  50
  51#define __I915_EXEC_ILLEGAL_FLAGS \
  52	(__I915_EXEC_UNKNOWN_FLAGS | \
  53	 I915_EXEC_CONSTANTS_MASK  | \
  54	 I915_EXEC_RESOURCE_STREAMER)
  55
  56/* Catch emission of unexpected errors for CI! */
  57#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM)
  58#undef EINVAL
  59#define EINVAL ({ \
  60	DRM_DEBUG_DRIVER("EINVAL at %s:%d\n", __func__, __LINE__); \
  61	22; \
  62})
  63#endif
  64
  65/**
  66 * DOC: User command execution
  67 *
  68 * Userspace submits commands to be executed on the GPU as an instruction
  69 * stream within a GEM object we call a batchbuffer. This instructions may
  70 * refer to other GEM objects containing auxiliary state such as kernels,
  71 * samplers, render targets and even secondary batchbuffers. Userspace does
  72 * not know where in the GPU memory these objects reside and so before the
  73 * batchbuffer is passed to the GPU for execution, those addresses in the
  74 * batchbuffer and auxiliary objects are updated. This is known as relocation,
  75 * or patching. To try and avoid having to relocate each object on the next
  76 * execution, userspace is told the location of those objects in this pass,
  77 * but this remains just a hint as the kernel may choose a new location for
  78 * any object in the future.
  79 *
  80 * At the level of talking to the hardware, submitting a batchbuffer for the
  81 * GPU to execute is to add content to a buffer from which the HW
  82 * command streamer is reading.
  83 *
  84 * 1. Add a command to load the HW context. For Logical Ring Contexts, i.e.
  85 *    Execlists, this command is not placed on the same buffer as the
  86 *    remaining items.
  87 *
  88 * 2. Add a command to invalidate caches to the buffer.
  89 *
  90 * 3. Add a batchbuffer start command to the buffer; the start command is
  91 *    essentially a token together with the GPU address of the batchbuffer
  92 *    to be executed.
  93 *
  94 * 4. Add a pipeline flush to the buffer.
  95 *
  96 * 5. Add a memory write command to the buffer to record when the GPU
  97 *    is done executing the batchbuffer. The memory write writes the
  98 *    global sequence number of the request, ``i915_request::global_seqno``;
  99 *    the i915 driver uses the current value in the register to determine
 100 *    if the GPU has completed the batchbuffer.
 101 *
 102 * 6. Add a user interrupt command to the buffer. This command instructs
 103 *    the GPU to issue an interrupt when the command, pipeline flush and
 104 *    memory write are completed.
 105 *
 106 * 7. Inform the hardware of the additional commands added to the buffer
 107 *    (by updating the tail pointer).
 108 *
 109 * Processing an execbuf ioctl is conceptually split up into a few phases.
 110 *
 111 * 1. Validation - Ensure all the pointers, handles and flags are valid.
 112 * 2. Reservation - Assign GPU address space for every object
 113 * 3. Relocation - Update any addresses to point to the final locations
 114 * 4. Serialisation - Order the request with respect to its dependencies
 115 * 5. Construction - Construct a request to execute the batchbuffer
 116 * 6. Submission (at some point in the future execution)
 117 *
 118 * Reserving resources for the execbuf is the most complicated phase. We
 119 * neither want to have to migrate the object in the address space, nor do
 120 * we want to have to update any relocations pointing to this object. Ideally,
 121 * we want to leave the object where it is and for all the existing relocations
 122 * to match. If the object is given a new address, or if userspace thinks the
 123 * object is elsewhere, we have to parse all the relocation entries and update
 124 * the addresses. Userspace can set the I915_EXEC_NORELOC flag to hint that
 125 * all the target addresses in all of its objects match the value in the
 126 * relocation entries and that they all match the presumed offsets given by the
 127 * list of execbuffer objects. Using this knowledge, we know that if we haven't
 128 * moved any buffers, all the relocation entries are valid and we can skip
 129 * the update. (If userspace is wrong, the likely outcome is an impromptu GPU
 130 * hang.) The requirement for using I915_EXEC_NO_RELOC are:
 131 *
 132 *      The addresses written in the objects must match the corresponding
 133 *      reloc.presumed_offset which in turn must match the corresponding
 134 *      execobject.offset.
 135 *
 136 *      Any render targets written to in the batch must be flagged with
 137 *      EXEC_OBJECT_WRITE.
 138 *
 139 *      To avoid stalling, execobject.offset should match the current
 140 *      address of that object within the active context.
 141 *
 142 * The reservation is done is multiple phases. First we try and keep any
 143 * object already bound in its current location - so as long as meets the
 144 * constraints imposed by the new execbuffer. Any object left unbound after the
 145 * first pass is then fitted into any available idle space. If an object does
 146 * not fit, all objects are removed from the reservation and the process rerun
 147 * after sorting the objects into a priority order (more difficult to fit
 148 * objects are tried first). Failing that, the entire VM is cleared and we try
 149 * to fit the execbuf once last time before concluding that it simply will not
 150 * fit.
 151 *
 152 * A small complication to all of this is that we allow userspace not only to
 153 * specify an alignment and a size for the object in the address space, but
 154 * we also allow userspace to specify the exact offset. This objects are
 155 * simpler to place (the location is known a priori) all we have to do is make
 156 * sure the space is available.
 157 *
 158 * Once all the objects are in place, patching up the buried pointers to point
 159 * to the final locations is a fairly simple job of walking over the relocation
 160 * entry arrays, looking up the right address and rewriting the value into
 161 * the object. Simple! ... The relocation entries are stored in user memory
 162 * and so to access them we have to copy them into a local buffer. That copy
 163 * has to avoid taking any pagefaults as they may lead back to a GEM object
 164 * requiring the struct_mutex (i.e. recursive deadlock). So once again we split
 165 * the relocation into multiple passes. First we try to do everything within an
 166 * atomic context (avoid the pagefaults) which requires that we never wait. If
 167 * we detect that we may wait, or if we need to fault, then we have to fallback
 168 * to a slower path. The slowpath has to drop the mutex. (Can you hear alarm
 169 * bells yet?) Dropping the mutex means that we lose all the state we have
 170 * built up so far for the execbuf and we must reset any global data. However,
 171 * we do leave the objects pinned in their final locations - which is a
 172 * potential issue for concurrent execbufs. Once we have left the mutex, we can
 173 * allocate and copy all the relocation entries into a large array at our
 174 * leisure, reacquire the mutex, reclaim all the objects and other state and
 175 * then proceed to update any incorrect addresses with the objects.
 176 *
 177 * As we process the relocation entries, we maintain a record of whether the
 178 * object is being written to. Using NORELOC, we expect userspace to provide
 179 * this information instead. We also check whether we can skip the relocation
 180 * by comparing the expected value inside the relocation entry with the target's
 181 * final address. If they differ, we have to map the current object and rewrite
 182 * the 4 or 8 byte pointer within.
 183 *
 184 * Serialising an execbuf is quite simple according to the rules of the GEM
 185 * ABI. Execution within each context is ordered by the order of submission.
 186 * Writes to any GEM object are in order of submission and are exclusive. Reads
 187 * from a GEM object are unordered with respect to other reads, but ordered by
 188 * writes. A write submitted after a read cannot occur before the read, and
 189 * similarly any read submitted after a write cannot occur before the write.
 190 * Writes are ordered between engines such that only one write occurs at any
 191 * time (completing any reads beforehand) - using semaphores where available
 192 * and CPU serialisation otherwise. Other GEM access obey the same rules, any
 193 * write (either via mmaps using set-domain, or via pwrite) must flush all GPU
 194 * reads before starting, and any read (either using set-domain or pread) must
 195 * flush all GPU writes before starting. (Note we only employ a barrier before,
 196 * we currently rely on userspace not concurrently starting a new execution
 197 * whilst reading or writing to an object. This may be an advantage or not
 198 * depending on how much you trust userspace not to shoot themselves in the
 199 * foot.) Serialisation may just result in the request being inserted into
 200 * a DAG awaiting its turn, but most simple is to wait on the CPU until
 201 * all dependencies are resolved.
 202 *
 203 * After all of that, is just a matter of closing the request and handing it to
 204 * the hardware (well, leaving it in a queue to be executed). However, we also
 205 * offer the ability for batchbuffers to be run with elevated privileges so
 206 * that they access otherwise hidden registers. (Used to adjust L3 cache etc.)
 207 * Before any batch is given extra privileges we first must check that it
 208 * contains no nefarious instructions, we check that each instruction is from
 209 * our whitelist and all registers are also from an allowed list. We first
 210 * copy the user's batchbuffer to a shadow (so that the user doesn't have
 211 * access to it, either by the CPU or GPU as we scan it) and then parse each
 212 * instruction. If everything is ok, we set a flag telling the hardware to run
 213 * the batchbuffer in trusted mode, otherwise the ioctl is rejected.
 214 */
 215
 216struct i915_execbuffer {
 217	struct drm_i915_private *i915; /** i915 backpointer */
 218	struct drm_file *file; /** per-file lookup tables and limits */
 219	struct drm_i915_gem_execbuffer2 *args; /** ioctl parameters */
 220	struct drm_i915_gem_exec_object2 *exec; /** ioctl execobj[] */
 221	struct i915_vma **vma;
 222	unsigned int *flags;
 223
 224	struct intel_engine_cs *engine; /** engine to queue the request to */
 225	struct intel_context *context; /* logical state for the request */
 226	struct i915_gem_context *gem_context; /** caller's context */
 227
 228	struct i915_request *request; /** our request to build */
 229	struct i915_vma *batch; /** identity of the batch obj/vma */
 230
 231	/** actual size of execobj[] as we may extend it for the cmdparser */
 232	unsigned int buffer_count;
 233
 234	/** list of vma not yet bound during reservation phase */
 235	struct list_head unbound;
 236
 237	/** list of vma that have execobj.relocation_count */
 238	struct list_head relocs;
 239
 240	/**
 241	 * Track the most recently used object for relocations, as we
 242	 * frequently have to perform multiple relocations within the same
 243	 * obj/page
 244	 */
 245	struct reloc_cache {
 246		struct drm_mm_node node; /** temporary GTT binding */
 247		unsigned long vaddr; /** Current kmap address */
 248		unsigned long page; /** Currently mapped page index */
 249		unsigned int gen; /** Cached value of INTEL_GEN */
 250		bool use_64bit_reloc : 1;
 251		bool has_llc : 1;
 252		bool has_fence : 1;
 253		bool needs_unfenced : 1;
 254
 255		struct i915_request *rq;
 256		u32 *rq_cmd;
 257		unsigned int rq_size;
 258	} reloc_cache;
 259
 260	u64 invalid_flags; /** Set of execobj.flags that are invalid */
 261	u32 context_flags; /** Set of execobj.flags to insert from the ctx */
 262
 263	u32 batch_start_offset; /** Location within object of batch */
 264	u32 batch_len; /** Length of batch within object */
 265	u32 batch_flags; /** Flags composed for emit_bb_start() */
 266
 267	/**
 268	 * Indicate either the size of the hastable used to resolve
 269	 * relocation handles, or if negative that we are using a direct
 270	 * index into the execobj[].
 271	 */
 272	int lut_size;
 273	struct hlist_head *buckets; /** ht for relocation handles */
 274};
 275
 276#define exec_entry(EB, VMA) (&(EB)->exec[(VMA)->exec_flags - (EB)->flags])
 277
 278/*
 279 * Used to convert any address to canonical form.
 280 * Starting from gen8, some commands (e.g. STATE_BASE_ADDRESS,
 281 * MI_LOAD_REGISTER_MEM and others, see Broadwell PRM Vol2a) require the
 282 * addresses to be in a canonical form:
 283 * "GraphicsAddress[63:48] are ignored by the HW and assumed to be in correct
 284 * canonical form [63:48] == [47]."
 285 */
 286#define GEN8_HIGH_ADDRESS_BIT 47
 287static inline u64 gen8_canonical_addr(u64 address)
 288{
 289	return sign_extend64(address, GEN8_HIGH_ADDRESS_BIT);
 290}
 291
 292static inline u64 gen8_noncanonical_addr(u64 address)
 293{
 294	return address & GENMASK_ULL(GEN8_HIGH_ADDRESS_BIT, 0);
 295}
 296
 297static inline bool eb_use_cmdparser(const struct i915_execbuffer *eb)
 298{
 299	return intel_engine_requires_cmd_parser(eb->engine) ||
 300		(intel_engine_using_cmd_parser(eb->engine) &&
 301		 eb->args->batch_len);
 302}
 303
 304static int eb_create(struct i915_execbuffer *eb)
 305{
 306	if (!(eb->args->flags & I915_EXEC_HANDLE_LUT)) {
 307		unsigned int size = 1 + ilog2(eb->buffer_count);
 308
 309		/*
 310		 * Without a 1:1 association between relocation handles and
 311		 * the execobject[] index, we instead create a hashtable.
 312		 * We size it dynamically based on available memory, starting
 313		 * first with 1:1 assocative hash and scaling back until
 314		 * the allocation succeeds.
 315		 *
 316		 * Later on we use a positive lut_size to indicate we are
 317		 * using this hashtable, and a negative value to indicate a
 318		 * direct lookup.
 319		 */
 320		do {
 321			gfp_t flags;
 322
 323			/* While we can still reduce the allocation size, don't
 324			 * raise a warning and allow the allocation to fail.
 325			 * On the last pass though, we want to try as hard
 326			 * as possible to perform the allocation and warn
 327			 * if it fails.
 328			 */
 329			flags = GFP_KERNEL;
 330			if (size > 1)
 331				flags |= __GFP_NORETRY | __GFP_NOWARN;
 332
 333			eb->buckets = kzalloc(sizeof(struct hlist_head) << size,
 334					      flags);
 335			if (eb->buckets)
 336				break;
 337		} while (--size);
 338
 339		if (unlikely(!size))
 340			return -ENOMEM;
 341
 342		eb->lut_size = size;
 343	} else {
 344		eb->lut_size = -eb->buffer_count;
 345	}
 346
 347	return 0;
 348}
 349
 350static bool
 351eb_vma_misplaced(const struct drm_i915_gem_exec_object2 *entry,
 352		 const struct i915_vma *vma,
 353		 unsigned int flags)
 354{
 355	if (vma->node.size < entry->pad_to_size)
 356		return true;
 357
 358	if (entry->alignment && !IS_ALIGNED(vma->node.start, entry->alignment))
 359		return true;
 360
 361	if (flags & EXEC_OBJECT_PINNED &&
 362	    vma->node.start != entry->offset)
 363		return true;
 364
 365	if (flags & __EXEC_OBJECT_NEEDS_BIAS &&
 366	    vma->node.start < BATCH_OFFSET_BIAS)
 367		return true;
 368
 369	if (!(flags & EXEC_OBJECT_SUPPORTS_48B_ADDRESS) &&
 370	    (vma->node.start + vma->node.size - 1) >> 32)
 371		return true;
 372
 373	if (flags & __EXEC_OBJECT_NEEDS_MAP &&
 374	    !i915_vma_is_map_and_fenceable(vma))
 375		return true;
 376
 377	return false;
 378}
 379
 380static inline bool
 381eb_pin_vma(struct i915_execbuffer *eb,
 382	   const struct drm_i915_gem_exec_object2 *entry,
 383	   struct i915_vma *vma)
 384{
 385	unsigned int exec_flags = *vma->exec_flags;
 386	u64 pin_flags;
 387
 388	if (vma->node.size)
 389		pin_flags = vma->node.start;
 390	else
 391		pin_flags = entry->offset & PIN_OFFSET_MASK;
 392
 393	pin_flags |= PIN_USER | PIN_NOEVICT | PIN_OFFSET_FIXED;
 394	if (unlikely(exec_flags & EXEC_OBJECT_NEEDS_GTT))
 395		pin_flags |= PIN_GLOBAL;
 396
 397	if (unlikely(i915_vma_pin(vma, 0, 0, pin_flags)))
 398		return false;
 399
 400	if (unlikely(exec_flags & EXEC_OBJECT_NEEDS_FENCE)) {
 401		if (unlikely(i915_vma_pin_fence(vma))) {
 402			i915_vma_unpin(vma);
 403			return false;
 404		}
 405
 406		if (vma->fence)
 407			exec_flags |= __EXEC_OBJECT_HAS_FENCE;
 408	}
 409
 410	*vma->exec_flags = exec_flags | __EXEC_OBJECT_HAS_PIN;
 411	return !eb_vma_misplaced(entry, vma, exec_flags);
 412}
 413
 414static inline void __eb_unreserve_vma(struct i915_vma *vma, unsigned int flags)
 415{
 416	GEM_BUG_ON(!(flags & __EXEC_OBJECT_HAS_PIN));
 417
 418	if (unlikely(flags & __EXEC_OBJECT_HAS_FENCE))
 419		__i915_vma_unpin_fence(vma);
 420
 421	__i915_vma_unpin(vma);
 422}
 423
 424static inline void
 425eb_unreserve_vma(struct i915_vma *vma, unsigned int *flags)
 426{
 427	if (!(*flags & __EXEC_OBJECT_HAS_PIN))
 428		return;
 429
 430	__eb_unreserve_vma(vma, *flags);
 431	*flags &= ~__EXEC_OBJECT_RESERVED;
 432}
 433
 434static int
 435eb_validate_vma(struct i915_execbuffer *eb,
 436		struct drm_i915_gem_exec_object2 *entry,
 437		struct i915_vma *vma)
 438{
 439	if (unlikely(entry->flags & eb->invalid_flags))
 440		return -EINVAL;
 441
 442	if (unlikely(entry->alignment && !is_power_of_2(entry->alignment)))
 443		return -EINVAL;
 444
 445	/*
 446	 * Offset can be used as input (EXEC_OBJECT_PINNED), reject
 447	 * any non-page-aligned or non-canonical addresses.
 448	 */
 449	if (unlikely(entry->flags & EXEC_OBJECT_PINNED &&
 450		     entry->offset != gen8_canonical_addr(entry->offset & I915_GTT_PAGE_MASK)))
 451		return -EINVAL;
 452
 453	/* pad_to_size was once a reserved field, so sanitize it */
 454	if (entry->flags & EXEC_OBJECT_PAD_TO_SIZE) {
 455		if (unlikely(offset_in_page(entry->pad_to_size)))
 456			return -EINVAL;
 457	} else {
 458		entry->pad_to_size = 0;
 459	}
 460
 461	if (unlikely(vma->exec_flags)) {
 462		DRM_DEBUG("Object [handle %d, index %d] appears more than once in object list\n",
 463			  entry->handle, (int)(entry - eb->exec));
 464		return -EINVAL;
 465	}
 466
 467	/*
 468	 * From drm_mm perspective address space is continuous,
 469	 * so from this point we're always using non-canonical
 470	 * form internally.
 471	 */
 472	entry->offset = gen8_noncanonical_addr(entry->offset);
 473
 474	if (!eb->reloc_cache.has_fence) {
 475		entry->flags &= ~EXEC_OBJECT_NEEDS_FENCE;
 476	} else {
 477		if ((entry->flags & EXEC_OBJECT_NEEDS_FENCE ||
 478		     eb->reloc_cache.needs_unfenced) &&
 479		    i915_gem_object_is_tiled(vma->obj))
 480			entry->flags |= EXEC_OBJECT_NEEDS_GTT | __EXEC_OBJECT_NEEDS_MAP;
 481	}
 482
 483	if (!(entry->flags & EXEC_OBJECT_PINNED))
 484		entry->flags |= eb->context_flags;
 485
 486	return 0;
 487}
 488
 489static int
 490eb_add_vma(struct i915_execbuffer *eb,
 491	   unsigned int i, unsigned batch_idx,
 492	   struct i915_vma *vma)
 493{
 494	struct drm_i915_gem_exec_object2 *entry = &eb->exec[i];
 495	int err;
 496
 497	GEM_BUG_ON(i915_vma_is_closed(vma));
 498
 499	if (!(eb->args->flags & __EXEC_VALIDATED)) {
 500		err = eb_validate_vma(eb, entry, vma);
 501		if (unlikely(err))
 502			return err;
 503	}
 504
 505	if (eb->lut_size > 0) {
 506		vma->exec_handle = entry->handle;
 507		hlist_add_head(&vma->exec_node,
 508			       &eb->buckets[hash_32(entry->handle,
 509						    eb->lut_size)]);
 510	}
 511
 512	if (entry->relocation_count)
 513		list_add_tail(&vma->reloc_link, &eb->relocs);
 514
 515	/*
 516	 * Stash a pointer from the vma to execobj, so we can query its flags,
 517	 * size, alignment etc as provided by the user. Also we stash a pointer
 518	 * to the vma inside the execobj so that we can use a direct lookup
 519	 * to find the right target VMA when doing relocations.
 520	 */
 521	eb->vma[i] = vma;
 522	eb->flags[i] = entry->flags;
 523	vma->exec_flags = &eb->flags[i];
 524
 525	/*
 526	 * SNA is doing fancy tricks with compressing batch buffers, which leads
 527	 * to negative relocation deltas. Usually that works out ok since the
 528	 * relocate address is still positive, except when the batch is placed
 529	 * very low in the GTT. Ensure this doesn't happen.
 530	 *
 531	 * Note that actual hangs have only been observed on gen7, but for
 532	 * paranoia do it everywhere.
 533	 */
 534	if (i == batch_idx) {
 535		if (entry->relocation_count &&
 536		    !(eb->flags[i] & EXEC_OBJECT_PINNED))
 537			eb->flags[i] |= __EXEC_OBJECT_NEEDS_BIAS;
 538		if (eb->reloc_cache.has_fence)
 539			eb->flags[i] |= EXEC_OBJECT_NEEDS_FENCE;
 540
 541		eb->batch = vma;
 542	}
 543
 544	err = 0;
 545	if (eb_pin_vma(eb, entry, vma)) {
 546		if (entry->offset != vma->node.start) {
 547			entry->offset = vma->node.start | UPDATE;
 548			eb->args->flags |= __EXEC_HAS_RELOC;
 549		}
 550	} else {
 551		eb_unreserve_vma(vma, vma->exec_flags);
 552
 553		list_add_tail(&vma->exec_link, &eb->unbound);
 554		if (drm_mm_node_allocated(&vma->node))
 555			err = i915_vma_unbind(vma);
 556		if (unlikely(err))
 557			vma->exec_flags = NULL;
 558	}
 559	return err;
 560}
 561
 562static inline int use_cpu_reloc(const struct reloc_cache *cache,
 563				const struct drm_i915_gem_object *obj)
 564{
 565	if (!i915_gem_object_has_struct_page(obj))
 566		return false;
 567
 568	if (DBG_FORCE_RELOC == FORCE_CPU_RELOC)
 569		return true;
 570
 571	if (DBG_FORCE_RELOC == FORCE_GTT_RELOC)
 572		return false;
 573
 574	return (cache->has_llc ||
 575		obj->cache_dirty ||
 576		obj->cache_level != I915_CACHE_NONE);
 577}
 578
 579static int eb_reserve_vma(const struct i915_execbuffer *eb,
 580			  struct i915_vma *vma)
 581{
 582	struct drm_i915_gem_exec_object2 *entry = exec_entry(eb, vma);
 583	unsigned int exec_flags = *vma->exec_flags;
 584	u64 pin_flags;
 585	int err;
 586
 587	pin_flags = PIN_USER | PIN_NONBLOCK;
 588	if (exec_flags & EXEC_OBJECT_NEEDS_GTT)
 589		pin_flags |= PIN_GLOBAL;
 590
 591	/*
 592	 * Wa32bitGeneralStateOffset & Wa32bitInstructionBaseOffset,
 593	 * limit address to the first 4GBs for unflagged objects.
 594	 */
 595	if (!(exec_flags & EXEC_OBJECT_SUPPORTS_48B_ADDRESS))
 596		pin_flags |= PIN_ZONE_4G;
 597
 598	if (exec_flags & __EXEC_OBJECT_NEEDS_MAP)
 599		pin_flags |= PIN_MAPPABLE;
 600
 601	if (exec_flags & EXEC_OBJECT_PINNED) {
 602		pin_flags |= entry->offset | PIN_OFFSET_FIXED;
 603		pin_flags &= ~PIN_NONBLOCK; /* force overlapping checks */
 604	} else if (exec_flags & __EXEC_OBJECT_NEEDS_BIAS) {
 605		pin_flags |= BATCH_OFFSET_BIAS | PIN_OFFSET_BIAS;
 606	}
 607
 608	err = i915_vma_pin(vma,
 609			   entry->pad_to_size, entry->alignment,
 610			   pin_flags);
 611	if (err)
 612		return err;
 613
 614	if (entry->offset != vma->node.start) {
 615		entry->offset = vma->node.start | UPDATE;
 616		eb->args->flags |= __EXEC_HAS_RELOC;
 617	}
 618
 619	if (unlikely(exec_flags & EXEC_OBJECT_NEEDS_FENCE)) {
 620		err = i915_vma_pin_fence(vma);
 621		if (unlikely(err)) {
 622			i915_vma_unpin(vma);
 623			return err;
 624		}
 625
 626		if (vma->fence)
 627			exec_flags |= __EXEC_OBJECT_HAS_FENCE;
 628	}
 629
 630	*vma->exec_flags = exec_flags | __EXEC_OBJECT_HAS_PIN;
 631	GEM_BUG_ON(eb_vma_misplaced(entry, vma, exec_flags));
 632
 633	return 0;
 634}
 635
 636static int eb_reserve(struct i915_execbuffer *eb)
 637{
 638	const unsigned int count = eb->buffer_count;
 639	struct list_head last;
 640	struct i915_vma *vma;
 641	unsigned int i, pass;
 642	int err;
 643
 644	/*
 645	 * Attempt to pin all of the buffers into the GTT.
 646	 * This is done in 3 phases:
 647	 *
 648	 * 1a. Unbind all objects that do not match the GTT constraints for
 649	 *     the execbuffer (fenceable, mappable, alignment etc).
 650	 * 1b. Increment pin count for already bound objects.
 651	 * 2.  Bind new objects.
 652	 * 3.  Decrement pin count.
 653	 *
 654	 * This avoid unnecessary unbinding of later objects in order to make
 655	 * room for the earlier objects *unless* we need to defragment.
 656	 */
 657
 658	pass = 0;
 659	err = 0;
 660	do {
 661		list_for_each_entry(vma, &eb->unbound, exec_link) {
 662			err = eb_reserve_vma(eb, vma);
 663			if (err)
 664				break;
 665		}
 666		if (err != -ENOSPC)
 667			return err;
 668
 669		/* Resort *all* the objects into priority order */
 670		INIT_LIST_HEAD(&eb->unbound);
 671		INIT_LIST_HEAD(&last);
 672		for (i = 0; i < count; i++) {
 673			unsigned int flags = eb->flags[i];
 674			struct i915_vma *vma = eb->vma[i];
 675
 676			if (flags & EXEC_OBJECT_PINNED &&
 677			    flags & __EXEC_OBJECT_HAS_PIN)
 678				continue;
 679
 680			eb_unreserve_vma(vma, &eb->flags[i]);
 681
 682			if (flags & EXEC_OBJECT_PINNED)
 683				/* Pinned must have their slot */
 684				list_add(&vma->exec_link, &eb->unbound);
 685			else if (flags & __EXEC_OBJECT_NEEDS_MAP)
 686				/* Map require the lowest 256MiB (aperture) */
 687				list_add_tail(&vma->exec_link, &eb->unbound);
 688			else if (!(flags & EXEC_OBJECT_SUPPORTS_48B_ADDRESS))
 689				/* Prioritise 4GiB region for restricted bo */
 690				list_add(&vma->exec_link, &last);
 691			else
 692				list_add_tail(&vma->exec_link, &last);
 693		}
 694		list_splice_tail(&last, &eb->unbound);
 695
 696		switch (pass++) {
 697		case 0:
 698			break;
 699
 700		case 1:
 701			/* Too fragmented, unbind everything and retry */
 702			err = i915_gem_evict_vm(eb->context->vm);
 703			if (err)
 704				return err;
 705			break;
 706
 707		default:
 708			return -ENOSPC;
 709		}
 710	} while (1);
 711}
 712
 713static unsigned int eb_batch_index(const struct i915_execbuffer *eb)
 714{
 715	if (eb->args->flags & I915_EXEC_BATCH_FIRST)
 716		return 0;
 717	else
 718		return eb->buffer_count - 1;
 719}
 720
 721static int eb_select_context(struct i915_execbuffer *eb)
 722{
 723	struct i915_gem_context *ctx;
 724
 725	ctx = i915_gem_context_lookup(eb->file->driver_priv, eb->args->rsvd1);
 726	if (unlikely(!ctx))
 727		return -ENOENT;
 728
 729	eb->gem_context = ctx;
 730	if (ctx->vm)
 731		eb->invalid_flags |= EXEC_OBJECT_NEEDS_GTT;
 732
 733	eb->context_flags = 0;
 734	if (test_bit(UCONTEXT_NO_ZEROMAP, &ctx->user_flags))
 735		eb->context_flags |= __EXEC_OBJECT_NEEDS_BIAS;
 736
 737	return 0;
 738}
 739
 740static int eb_lookup_vmas(struct i915_execbuffer *eb)
 741{
 742	struct radix_tree_root *handles_vma = &eb->gem_context->handles_vma;
 743	struct drm_i915_gem_object *obj;
 744	unsigned int i, batch;
 745	int err;
 746
 747	if (unlikely(i915_gem_context_is_banned(eb->gem_context)))
 748		return -EIO;
 749
 750	INIT_LIST_HEAD(&eb->relocs);
 751	INIT_LIST_HEAD(&eb->unbound);
 752
 753	batch = eb_batch_index(eb);
 754
 755	mutex_lock(&eb->gem_context->mutex);
 756	if (unlikely(i915_gem_context_is_closed(eb->gem_context))) {
 757		err = -ENOENT;
 758		goto err_ctx;
 759	}
 760
 761	for (i = 0; i < eb->buffer_count; i++) {
 762		u32 handle = eb->exec[i].handle;
 763		struct i915_lut_handle *lut;
 764		struct i915_vma *vma;
 765
 766		vma = radix_tree_lookup(handles_vma, handle);
 767		if (likely(vma))
 768			goto add_vma;
 769
 770		obj = i915_gem_object_lookup(eb->file, handle);
 771		if (unlikely(!obj)) {
 772			err = -ENOENT;
 773			goto err_vma;
 774		}
 775
 776		vma = i915_vma_instance(obj, eb->context->vm, NULL);
 777		if (IS_ERR(vma)) {
 778			err = PTR_ERR(vma);
 779			goto err_obj;
 780		}
 781
 782		lut = i915_lut_handle_alloc();
 783		if (unlikely(!lut)) {
 784			err = -ENOMEM;
 785			goto err_obj;
 786		}
 787
 788		err = radix_tree_insert(handles_vma, handle, vma);
 789		if (unlikely(err)) {
 790			i915_lut_handle_free(lut);
 791			goto err_obj;
 792		}
 793
 794		/* transfer ref to lut */
 795		if (!atomic_fetch_inc(&vma->open_count))
 796			i915_vma_reopen(vma);
 797		lut->handle = handle;
 798		lut->ctx = eb->gem_context;
 799
 800		i915_gem_object_lock(obj);
 801		list_add(&lut->obj_link, &obj->lut_list);
 802		i915_gem_object_unlock(obj);
 803
 804add_vma:
 805		err = eb_add_vma(eb, i, batch, vma);
 806		if (unlikely(err))
 807			goto err_vma;
 808
 809		GEM_BUG_ON(vma != eb->vma[i]);
 810		GEM_BUG_ON(vma->exec_flags != &eb->flags[i]);
 811		GEM_BUG_ON(drm_mm_node_allocated(&vma->node) &&
 812			   eb_vma_misplaced(&eb->exec[i], vma, eb->flags[i]));
 813	}
 814
 815	mutex_unlock(&eb->gem_context->mutex);
 816
 817	eb->args->flags |= __EXEC_VALIDATED;
 818	return eb_reserve(eb);
 819
 820err_obj:
 821	i915_gem_object_put(obj);
 822err_vma:
 823	eb->vma[i] = NULL;
 824err_ctx:
 825	mutex_unlock(&eb->gem_context->mutex);
 826	return err;
 827}
 828
 829static struct i915_vma *
 830eb_get_vma(const struct i915_execbuffer *eb, unsigned long handle)
 831{
 832	if (eb->lut_size < 0) {
 833		if (handle >= -eb->lut_size)
 834			return NULL;
 835		return eb->vma[handle];
 836	} else {
 837		struct hlist_head *head;
 838		struct i915_vma *vma;
 839
 840		head = &eb->buckets[hash_32(handle, eb->lut_size)];
 841		hlist_for_each_entry(vma, head, exec_node) {
 842			if (vma->exec_handle == handle)
 843				return vma;
 844		}
 845		return NULL;
 846	}
 847}
 848
 849static void eb_release_vmas(const struct i915_execbuffer *eb)
 850{
 851	const unsigned int count = eb->buffer_count;
 852	unsigned int i;
 853
 854	for (i = 0; i < count; i++) {
 855		struct i915_vma *vma = eb->vma[i];
 856		unsigned int flags = eb->flags[i];
 857
 858		if (!vma)
 859			break;
 860
 861		GEM_BUG_ON(vma->exec_flags != &eb->flags[i]);
 862		vma->exec_flags = NULL;
 863		eb->vma[i] = NULL;
 864
 865		if (flags & __EXEC_OBJECT_HAS_PIN)
 866			__eb_unreserve_vma(vma, flags);
 867
 868		if (flags & __EXEC_OBJECT_HAS_REF)
 869			i915_vma_put(vma);
 870	}
 871}
 872
 873static void eb_reset_vmas(const struct i915_execbuffer *eb)
 874{
 875	eb_release_vmas(eb);
 876	if (eb->lut_size > 0)
 877		memset(eb->buckets, 0,
 878		       sizeof(struct hlist_head) << eb->lut_size);
 879}
 880
 881static void eb_destroy(const struct i915_execbuffer *eb)
 882{
 883	GEM_BUG_ON(eb->reloc_cache.rq);
 884
 885	if (eb->lut_size > 0)
 886		kfree(eb->buckets);
 887}
 888
 889static inline u64
 890relocation_target(const struct drm_i915_gem_relocation_entry *reloc,
 891		  const struct i915_vma *target)
 892{
 893	return gen8_canonical_addr((int)reloc->delta + target->node.start);
 894}
 895
 896static void reloc_cache_init(struct reloc_cache *cache,
 897			     struct drm_i915_private *i915)
 898{
 899	cache->page = -1;
 900	cache->vaddr = 0;
 901	/* Must be a variable in the struct to allow GCC to unroll. */
 902	cache->gen = INTEL_GEN(i915);
 903	cache->has_llc = HAS_LLC(i915);
 904	cache->use_64bit_reloc = HAS_64BIT_RELOC(i915);
 905	cache->has_fence = cache->gen < 4;
 906	cache->needs_unfenced = INTEL_INFO(i915)->unfenced_needs_alignment;
 907	cache->node.allocated = false;
 908	cache->rq = NULL;
 909	cache->rq_size = 0;
 910}
 911
 912static inline void *unmask_page(unsigned long p)
 913{
 914	return (void *)(uintptr_t)(p & PAGE_MASK);
 915}
 916
 917static inline unsigned int unmask_flags(unsigned long p)
 918{
 919	return p & ~PAGE_MASK;
 920}
 921
 922#define KMAP 0x4 /* after CLFLUSH_FLAGS */
 923
 924static inline struct i915_ggtt *cache_to_ggtt(struct reloc_cache *cache)
 925{
 926	struct drm_i915_private *i915 =
 927		container_of(cache, struct i915_execbuffer, reloc_cache)->i915;
 928	return &i915->ggtt;
 929}
 930
 931static void reloc_gpu_flush(struct reloc_cache *cache)
 932{
 933	GEM_BUG_ON(cache->rq_size >= cache->rq->batch->obj->base.size / sizeof(u32));
 934	cache->rq_cmd[cache->rq_size] = MI_BATCH_BUFFER_END;
 935
 936	__i915_gem_object_flush_map(cache->rq->batch->obj, 0, cache->rq_size);
 937	i915_gem_object_unpin_map(cache->rq->batch->obj);
 938
 939	intel_gt_chipset_flush(cache->rq->engine->gt);
 940
 941	i915_request_add(cache->rq);
 942	cache->rq = NULL;
 943}
 944
 945static void reloc_cache_reset(struct reloc_cache *cache)
 946{
 947	void *vaddr;
 948
 949	if (cache->rq)
 950		reloc_gpu_flush(cache);
 951
 952	if (!cache->vaddr)
 953		return;
 954
 955	vaddr = unmask_page(cache->vaddr);
 956	if (cache->vaddr & KMAP) {
 957		if (cache->vaddr & CLFLUSH_AFTER)
 958			mb();
 959
 960		kunmap_atomic(vaddr);
 961		i915_gem_object_finish_access((struct drm_i915_gem_object *)cache->node.mm);
 962	} else {
 963		struct i915_ggtt *ggtt = cache_to_ggtt(cache);
 964
 965		intel_gt_flush_ggtt_writes(ggtt->vm.gt);
 966		io_mapping_unmap_atomic((void __iomem *)vaddr);
 967
 968		if (cache->node.allocated) {
 969			ggtt->vm.clear_range(&ggtt->vm,
 970					     cache->node.start,
 971					     cache->node.size);
 972			drm_mm_remove_node(&cache->node);
 973		} else {
 974			i915_vma_unpin((struct i915_vma *)cache->node.mm);
 975		}
 976	}
 977
 978	cache->vaddr = 0;
 979	cache->page = -1;
 980}
 981
 982static void *reloc_kmap(struct drm_i915_gem_object *obj,
 983			struct reloc_cache *cache,
 984			unsigned long page)
 985{
 986	void *vaddr;
 987
 988	if (cache->vaddr) {
 989		kunmap_atomic(unmask_page(cache->vaddr));
 990	} else {
 991		unsigned int flushes;
 992		int err;
 993
 994		err = i915_gem_object_prepare_write(obj, &flushes);
 995		if (err)
 996			return ERR_PTR(err);
 997
 998		BUILD_BUG_ON(KMAP & CLFLUSH_FLAGS);
 999		BUILD_BUG_ON((KMAP | CLFLUSH_FLAGS) & PAGE_MASK);
1000
1001		cache->vaddr = flushes | KMAP;
1002		cache->node.mm = (void *)obj;
1003		if (flushes)
1004			mb();
1005	}
1006
1007	vaddr = kmap_atomic(i915_gem_object_get_dirty_page(obj, page));
1008	cache->vaddr = unmask_flags(cache->vaddr) | (unsigned long)vaddr;
1009	cache->page = page;
1010
1011	return vaddr;
1012}
1013
1014static void *reloc_iomap(struct drm_i915_gem_object *obj,
1015			 struct reloc_cache *cache,
1016			 unsigned long page)
1017{
1018	struct i915_ggtt *ggtt = cache_to_ggtt(cache);
1019	unsigned long offset;
1020	void *vaddr;
1021
1022	if (cache->vaddr) {
1023		intel_gt_flush_ggtt_writes(ggtt->vm.gt);
1024		io_mapping_unmap_atomic((void __force __iomem *) unmask_page(cache->vaddr));
1025	} else {
1026		struct i915_vma *vma;
1027		int err;
1028
1029		if (i915_gem_object_is_tiled(obj))
1030			return ERR_PTR(-EINVAL);
1031
1032		if (use_cpu_reloc(cache, obj))
1033			return NULL;
1034
1035		i915_gem_object_lock(obj);
1036		err = i915_gem_object_set_to_gtt_domain(obj, true);
1037		i915_gem_object_unlock(obj);
1038		if (err)
1039			return ERR_PTR(err);
1040
1041		vma = i915_gem_object_ggtt_pin(obj, NULL, 0, 0,
1042					       PIN_MAPPABLE |
1043					       PIN_NONBLOCK /* NOWARN */ |
1044					       PIN_NOEVICT);
1045		if (IS_ERR(vma)) {
1046			memset(&cache->node, 0, sizeof(cache->node));
1047			err = drm_mm_insert_node_in_range
1048				(&ggtt->vm.mm, &cache->node,
1049				 PAGE_SIZE, 0, I915_COLOR_UNEVICTABLE,
1050				 0, ggtt->mappable_end,
1051				 DRM_MM_INSERT_LOW);
1052			if (err) /* no inactive aperture space, use cpu reloc */
1053				return NULL;
1054		} else {
1055			cache->node.start = vma->node.start;
1056			cache->node.mm = (void *)vma;
1057		}
1058	}
1059
1060	offset = cache->node.start;
1061	if (cache->node.allocated) {
1062		ggtt->vm.insert_page(&ggtt->vm,
1063				     i915_gem_object_get_dma_address(obj, page),
1064				     offset, I915_CACHE_NONE, 0);
1065	} else {
1066		offset += page << PAGE_SHIFT;
1067	}
1068
1069	vaddr = (void __force *)io_mapping_map_atomic_wc(&ggtt->iomap,
1070							 offset);
1071	cache->page = page;
1072	cache->vaddr = (unsigned long)vaddr;
1073
1074	return vaddr;
1075}
1076
1077static void *reloc_vaddr(struct drm_i915_gem_object *obj,
1078			 struct reloc_cache *cache,
1079			 unsigned long page)
1080{
1081	void *vaddr;
1082
1083	if (cache->page == page) {
1084		vaddr = unmask_page(cache->vaddr);
1085	} else {
1086		vaddr = NULL;
1087		if ((cache->vaddr & KMAP) == 0)
1088			vaddr = reloc_iomap(obj, cache, page);
1089		if (!vaddr)
1090			vaddr = reloc_kmap(obj, cache, page);
1091	}
1092
1093	return vaddr;
1094}
1095
1096static void clflush_write32(u32 *addr, u32 value, unsigned int flushes)
1097{
1098	if (unlikely(flushes & (CLFLUSH_BEFORE | CLFLUSH_AFTER))) {
1099		if (flushes & CLFLUSH_BEFORE) {
1100			clflushopt(addr);
1101			mb();
1102		}
1103
1104		*addr = value;
1105
1106		/*
1107		 * Writes to the same cacheline are serialised by the CPU
1108		 * (including clflush). On the write path, we only require
1109		 * that it hits memory in an orderly fashion and place
1110		 * mb barriers at the start and end of the relocation phase
1111		 * to ensure ordering of clflush wrt to the system.
1112		 */
1113		if (flushes & CLFLUSH_AFTER)
1114			clflushopt(addr);
1115	} else
1116		*addr = value;
1117}
1118
1119static int reloc_move_to_gpu(struct i915_request *rq, struct i915_vma *vma)
1120{
1121	struct drm_i915_gem_object *obj = vma->obj;
1122	int err;
1123
1124	i915_vma_lock(vma);
1125
1126	if (obj->cache_dirty & ~obj->cache_coherent)
1127		i915_gem_clflush_object(obj, 0);
1128	obj->write_domain = 0;
1129
1130	err = i915_request_await_object(rq, vma->obj, true);
1131	if (err == 0)
1132		err = i915_vma_move_to_active(vma, rq, EXEC_OBJECT_WRITE);
1133
1134	i915_vma_unlock(vma);
1135
1136	return err;
1137}
1138
1139static int __reloc_gpu_alloc(struct i915_execbuffer *eb,
1140			     struct i915_vma *vma,
1141			     unsigned int len)
1142{
1143	struct reloc_cache *cache = &eb->reloc_cache;
1144	struct intel_engine_pool_node *pool;
1145	struct i915_request *rq;
1146	struct i915_vma *batch;
1147	u32 *cmd;
1148	int err;
1149
1150	pool = intel_engine_pool_get(&eb->engine->pool, PAGE_SIZE);
1151	if (IS_ERR(pool))
1152		return PTR_ERR(pool);
1153
1154	cmd = i915_gem_object_pin_map(pool->obj,
1155				      cache->has_llc ?
1156				      I915_MAP_FORCE_WB :
1157				      I915_MAP_FORCE_WC);
1158	if (IS_ERR(cmd)) {
1159		err = PTR_ERR(cmd);
1160		goto out_pool;
1161	}
1162
1163	batch = i915_vma_instance(pool->obj, vma->vm, NULL);
1164	if (IS_ERR(batch)) {
1165		err = PTR_ERR(batch);
1166		goto err_unmap;
1167	}
1168
1169	err = i915_vma_pin(batch, 0, 0, PIN_USER | PIN_NONBLOCK);
1170	if (err)
1171		goto err_unmap;
1172
1173	rq = i915_request_create(eb->context);
1174	if (IS_ERR(rq)) {
1175		err = PTR_ERR(rq);
1176		goto err_unpin;
1177	}
1178
1179	err = intel_engine_pool_mark_active(pool, rq);
1180	if (err)
1181		goto err_request;
1182
1183	err = reloc_move_to_gpu(rq, vma);
1184	if (err)
1185		goto err_request;
1186
1187	err = eb->engine->emit_bb_start(rq,
1188					batch->node.start, PAGE_SIZE,
1189					cache->gen > 5 ? 0 : I915_DISPATCH_SECURE);
1190	if (err)
1191		goto skip_request;
1192
1193	i915_vma_lock(batch);
1194	err = i915_request_await_object(rq, batch->obj, false);
1195	if (err == 0)
1196		err = i915_vma_move_to_active(batch, rq, 0);
1197	i915_vma_unlock(batch);
1198	if (err)
1199		goto skip_request;
1200
1201	rq->batch = batch;
1202	i915_vma_unpin(batch);
1203
1204	cache->rq = rq;
1205	cache->rq_cmd = cmd;
1206	cache->rq_size = 0;
1207
1208	/* Return with batch mapping (cmd) still pinned */
1209	goto out_pool;
1210
1211skip_request:
1212	i915_request_skip(rq, err);
1213err_request:
1214	i915_request_add(rq);
1215err_unpin:
1216	i915_vma_unpin(batch);
1217err_unmap:
1218	i915_gem_object_unpin_map(pool->obj);
1219out_pool:
1220	intel_engine_pool_put(pool);
1221	return err;
1222}
1223
1224static u32 *reloc_gpu(struct i915_execbuffer *eb,
1225		      struct i915_vma *vma,
1226		      unsigned int len)
1227{
1228	struct reloc_cache *cache = &eb->reloc_cache;
1229	u32 *cmd;
1230
1231	if (cache->rq_size > PAGE_SIZE/sizeof(u32) - (len + 1))
1232		reloc_gpu_flush(cache);
1233
1234	if (unlikely(!cache->rq)) {
1235		int err;
1236
1237		/* If we need to copy for the cmdparser, we will stall anyway */
1238		if (eb_use_cmdparser(eb))
1239			return ERR_PTR(-EWOULDBLOCK);
1240
1241		if (!intel_engine_can_store_dword(eb->engine))
1242			return ERR_PTR(-ENODEV);
1243
1244		err = __reloc_gpu_alloc(eb, vma, len);
1245		if (unlikely(err))
1246			return ERR_PTR(err);
1247	}
1248
1249	cmd = cache->rq_cmd + cache->rq_size;
1250	cache->rq_size += len;
1251
1252	return cmd;
1253}
1254
1255static u64
1256relocate_entry(struct i915_vma *vma,
1257	       const struct drm_i915_gem_relocation_entry *reloc,
1258	       struct i915_execbuffer *eb,
1259	       const struct i915_vma *target)
1260{
1261	u64 offset = reloc->offset;
1262	u64 target_offset = relocation_target(reloc, target);
1263	bool wide = eb->reloc_cache.use_64bit_reloc;
1264	void *vaddr;
1265
1266	if (!eb->reloc_cache.vaddr &&
1267	    (DBG_FORCE_RELOC == FORCE_GPU_RELOC ||
1268	     !dma_resv_test_signaled_rcu(vma->resv, true))) {
1269		const unsigned int gen = eb->reloc_cache.gen;
1270		unsigned int len;
1271		u32 *batch;
1272		u64 addr;
1273
1274		if (wide)
1275			len = offset & 7 ? 8 : 5;
1276		else if (gen >= 4)
1277			len = 4;
1278		else
1279			len = 3;
1280
1281		batch = reloc_gpu(eb, vma, len);
1282		if (IS_ERR(batch))
1283			goto repeat;
1284
1285		addr = gen8_canonical_addr(vma->node.start + offset);
1286		if (wide) {
1287			if (offset & 7) {
1288				*batch++ = MI_STORE_DWORD_IMM_GEN4;
1289				*batch++ = lower_32_bits(addr);
1290				*batch++ = upper_32_bits(addr);
1291				*batch++ = lower_32_bits(target_offset);
1292
1293				addr = gen8_canonical_addr(addr + 4);
1294
1295				*batch++ = MI_STORE_DWORD_IMM_GEN4;
1296				*batch++ = lower_32_bits(addr);
1297				*batch++ = upper_32_bits(addr);
1298				*batch++ = upper_32_bits(target_offset);
1299			} else {
1300				*batch++ = (MI_STORE_DWORD_IMM_GEN4 | (1 << 21)) + 1;
1301				*batch++ = lower_32_bits(addr);
1302				*batch++ = upper_32_bits(addr);
1303				*batch++ = lower_32_bits(target_offset);
1304				*batch++ = upper_32_bits(target_offset);
1305			}
1306		} else if (gen >= 6) {
1307			*batch++ = MI_STORE_DWORD_IMM_GEN4;
1308			*batch++ = 0;
1309			*batch++ = addr;
1310			*batch++ = target_offset;
1311		} else if (gen >= 4) {
1312			*batch++ = MI_STORE_DWORD_IMM_GEN4 | MI_USE_GGTT;
1313			*batch++ = 0;
1314			*batch++ = addr;
1315			*batch++ = target_offset;
1316		} else {
1317			*batch++ = MI_STORE_DWORD_IMM | MI_MEM_VIRTUAL;
1318			*batch++ = addr;
1319			*batch++ = target_offset;
1320		}
1321
1322		goto out;
1323	}
1324
1325repeat:
1326	vaddr = reloc_vaddr(vma->obj, &eb->reloc_cache, offset >> PAGE_SHIFT);
1327	if (IS_ERR(vaddr))
1328		return PTR_ERR(vaddr);
1329
1330	clflush_write32(vaddr + offset_in_page(offset),
1331			lower_32_bits(target_offset),
1332			eb->reloc_cache.vaddr);
1333
1334	if (wide) {
1335		offset += sizeof(u32);
1336		target_offset >>= 32;
1337		wide = false;
1338		goto repeat;
1339	}
1340
1341out:
1342	return target->node.start | UPDATE;
1343}
1344
1345static u64
1346eb_relocate_entry(struct i915_execbuffer *eb,
1347		  struct i915_vma *vma,
1348		  const struct drm_i915_gem_relocation_entry *reloc)
1349{
1350	struct i915_vma *target;
1351	int err;
1352
1353	/* we've already hold a reference to all valid objects */
1354	target = eb_get_vma(eb, reloc->target_handle);
1355	if (unlikely(!target))
1356		return -ENOENT;
1357
1358	/* Validate that the target is in a valid r/w GPU domain */
1359	if (unlikely(reloc->write_domain & (reloc->write_domain - 1))) {
1360		DRM_DEBUG("reloc with multiple write domains: "
1361			  "target %d offset %d "
1362			  "read %08x write %08x",
1363			  reloc->target_handle,
1364			  (int) reloc->offset,
1365			  reloc->read_domains,
1366			  reloc->write_domain);
1367		return -EINVAL;
1368	}
1369	if (unlikely((reloc->write_domain | reloc->read_domains)
1370		     & ~I915_GEM_GPU_DOMAINS)) {
1371		DRM_DEBUG("reloc with read/write non-GPU domains: "
1372			  "target %d offset %d "
1373			  "read %08x write %08x",
1374			  reloc->target_handle,
1375			  (int) reloc->offset,
1376			  reloc->read_domains,
1377			  reloc->write_domain);
1378		return -EINVAL;
1379	}
1380
1381	if (reloc->write_domain) {
1382		*target->exec_flags |= EXEC_OBJECT_WRITE;
1383
1384		/*
1385		 * Sandybridge PPGTT errata: We need a global gtt mapping
1386		 * for MI and pipe_control writes because the gpu doesn't
1387		 * properly redirect them through the ppgtt for non_secure
1388		 * batchbuffers.
1389		 */
1390		if (reloc->write_domain == I915_GEM_DOMAIN_INSTRUCTION &&
1391		    IS_GEN(eb->i915, 6)) {
1392			err = i915_vma_bind(target, target->obj->cache_level,
1393					    PIN_GLOBAL);
1394			if (WARN_ONCE(err,
1395				      "Unexpected failure to bind target VMA!"))
1396				return err;
1397		}
1398	}
1399
1400	/*
1401	 * If the relocation already has the right value in it, no
1402	 * more work needs to be done.
1403	 */
1404	if (!DBG_FORCE_RELOC &&
1405	    gen8_canonical_addr(target->node.start) == reloc->presumed_offset)
1406		return 0;
1407
1408	/* Check that the relocation address is valid... */
1409	if (unlikely(reloc->offset >
1410		     vma->size - (eb->reloc_cache.use_64bit_reloc ? 8 : 4))) {
1411		DRM_DEBUG("Relocation beyond object bounds: "
1412			  "target %d offset %d size %d.\n",
1413			  reloc->target_handle,
1414			  (int)reloc->offset,
1415			  (int)vma->size);
1416		return -EINVAL;
1417	}
1418	if (unlikely(reloc->offset & 3)) {
1419		DRM_DEBUG("Relocation not 4-byte aligned: "
1420			  "target %d offset %d.\n",
1421			  reloc->target_handle,
1422			  (int)reloc->offset);
1423		return -EINVAL;
1424	}
1425
1426	/*
1427	 * If we write into the object, we need to force the synchronisation
1428	 * barrier, either with an asynchronous clflush or if we executed the
1429	 * patching using the GPU (though that should be serialised by the
1430	 * timeline). To be completely sure, and since we are required to
1431	 * do relocations we are already stalling, disable the user's opt
1432	 * out of our synchronisation.
1433	 */
1434	*vma->exec_flags &= ~EXEC_OBJECT_ASYNC;
1435
1436	/* and update the user's relocation entry */
1437	return relocate_entry(vma, reloc, eb, target);
1438}
1439
1440static int eb_relocate_vma(struct i915_execbuffer *eb, struct i915_vma *vma)
1441{
1442#define N_RELOC(x) ((x) / sizeof(struct drm_i915_gem_relocation_entry))
1443	struct drm_i915_gem_relocation_entry stack[N_RELOC(512)];
1444	struct drm_i915_gem_relocation_entry __user *urelocs;
1445	const struct drm_i915_gem_exec_object2 *entry = exec_entry(eb, vma);
1446	unsigned int remain;
1447
1448	urelocs = u64_to_user_ptr(entry->relocs_ptr);
1449	remain = entry->relocation_count;
1450	if (unlikely(remain > N_RELOC(ULONG_MAX)))
1451		return -EINVAL;
1452
1453	/*
1454	 * We must check that the entire relocation array is safe
1455	 * to read. However, if the array is not writable the user loses
1456	 * the updated relocation values.
1457	 */
1458	if (unlikely(!access_ok(urelocs, remain*sizeof(*urelocs))))
1459		return -EFAULT;
1460
1461	do {
1462		struct drm_i915_gem_relocation_entry *r = stack;
1463		unsigned int count =
1464			min_t(unsigned int, remain, ARRAY_SIZE(stack));
1465		unsigned int copied;
1466
1467		/*
1468		 * This is the fast path and we cannot handle a pagefault
1469		 * whilst holding the struct mutex lest the user pass in the
1470		 * relocations contained within a mmaped bo. For in such a case
1471		 * we, the page fault handler would call i915_gem_fault() and
1472		 * we would try to acquire the struct mutex again. Obviously
1473		 * this is bad and so lockdep complains vehemently.
1474		 */
1475		pagefault_disable();
1476		copied = __copy_from_user_inatomic(r, urelocs, count * sizeof(r[0]));
1477		pagefault_enable();
1478		if (unlikely(copied)) {
1479			remain = -EFAULT;
1480			goto out;
1481		}
1482
1483		remain -= count;
1484		do {
1485			u64 offset = eb_relocate_entry(eb, vma, r);
1486
1487			if (likely(offset == 0)) {
1488			} else if ((s64)offset < 0) {
1489				remain = (int)offset;
1490				goto out;
1491			} else {
1492				/*
1493				 * Note that reporting an error now
1494				 * leaves everything in an inconsistent
1495				 * state as we have *already* changed
1496				 * the relocation value inside the
1497				 * object. As we have not changed the
1498				 * reloc.presumed_offset or will not
1499				 * change the execobject.offset, on the
1500				 * call we may not rewrite the value
1501				 * inside the object, leaving it
1502				 * dangling and causing a GPU hang. Unless
1503				 * userspace dynamically rebuilds the
1504				 * relocations on each execbuf rather than
1505				 * presume a static tree.
1506				 *
1507				 * We did previously check if the relocations
1508				 * were writable (access_ok), an error now
1509				 * would be a strange race with mprotect,
1510				 * having already demonstrated that we
1511				 * can read from this userspace address.
1512				 */
1513				offset = gen8_canonical_addr(offset & ~UPDATE);
1514				if (unlikely(__put_user(offset, &urelocs[r-stack].presumed_offset))) {
1515					remain = -EFAULT;
1516					goto out;
1517				}
1518			}
1519		} while (r++, --count);
1520		urelocs += ARRAY_SIZE(stack);
1521	} while (remain);
1522out:
1523	reloc_cache_reset(&eb->reloc_cache);
1524	return remain;
1525}
1526
1527static int
1528eb_relocate_vma_slow(struct i915_execbuffer *eb, struct i915_vma *vma)
1529{
1530	const struct drm_i915_gem_exec_object2 *entry = exec_entry(eb, vma);
1531	struct drm_i915_gem_relocation_entry *relocs =
1532		u64_to_ptr(typeof(*relocs), entry->relocs_ptr);
1533	unsigned int i;
1534	int err;
1535
1536	for (i = 0; i < entry->relocation_count; i++) {
1537		u64 offset = eb_relocate_entry(eb, vma, &relocs[i]);
1538
1539		if ((s64)offset < 0) {
1540			err = (int)offset;
1541			goto err;
1542		}
1543	}
1544	err = 0;
1545err:
1546	reloc_cache_reset(&eb->reloc_cache);
1547	return err;
1548}
1549
1550static int check_relocations(const struct drm_i915_gem_exec_object2 *entry)
1551{
1552	const char __user *addr, *end;
1553	unsigned long size;
1554	char __maybe_unused c;
1555
1556	size = entry->relocation_count;
1557	if (size == 0)
1558		return 0;
1559
1560	if (size > N_RELOC(ULONG_MAX))
1561		return -EINVAL;
1562
1563	addr = u64_to_user_ptr(entry->relocs_ptr);
1564	size *= sizeof(struct drm_i915_gem_relocation_entry);
1565	if (!access_ok(addr, size))
1566		return -EFAULT;
1567
1568	end = addr + size;
1569	for (; addr < end; addr += PAGE_SIZE) {
1570		int err = __get_user(c, addr);
1571		if (err)
1572			return err;
1573	}
1574	return __get_user(c, end - 1);
1575}
1576
1577static int eb_copy_relocations(const struct i915_execbuffer *eb)
1578{
1579	struct drm_i915_gem_relocation_entry *relocs;
1580	const unsigned int count = eb->buffer_count;
1581	unsigned int i;
1582	int err;
1583
1584	for (i = 0; i < count; i++) {
1585		const unsigned int nreloc = eb->exec[i].relocation_count;
1586		struct drm_i915_gem_relocation_entry __user *urelocs;
1587		unsigned long size;
1588		unsigned long copied;
1589
1590		if (nreloc == 0)
1591			continue;
1592
1593		err = check_relocations(&eb->exec[i]);
1594		if (err)
1595			goto err;
1596
1597		urelocs = u64_to_user_ptr(eb->exec[i].relocs_ptr);
1598		size = nreloc * sizeof(*relocs);
1599
1600		relocs = kvmalloc_array(size, 1, GFP_KERNEL);
1601		if (!relocs) {
1602			err = -ENOMEM;
1603			goto err;
1604		}
1605
1606		/* copy_from_user is limited to < 4GiB */
1607		copied = 0;
1608		do {
1609			unsigned int len =
1610				min_t(u64, BIT_ULL(31), size - copied);
1611
1612			if (__copy_from_user((char *)relocs + copied,
1613					     (char __user *)urelocs + copied,
1614					     len))
1615				goto end;
1616
1617			copied += len;
1618		} while (copied < size);
1619
1620		/*
1621		 * As we do not update the known relocation offsets after
1622		 * relocating (due to the complexities in lock handling),
1623		 * we need to mark them as invalid now so that we force the
1624		 * relocation processing next time. Just in case the target
1625		 * object is evicted and then rebound into its old
1626		 * presumed_offset before the next execbuffer - if that
1627		 * happened we would make the mistake of assuming that the
1628		 * relocations were valid.
1629		 */
1630		if (!user_access_begin(urelocs, size))
1631			goto end;
1632
1633		for (copied = 0; copied < nreloc; copied++)
1634			unsafe_put_user(-1,
1635					&urelocs[copied].presumed_offset,
1636					end_user);
1637		user_access_end();
1638
1639		eb->exec[i].relocs_ptr = (uintptr_t)relocs;
1640	}
1641
1642	return 0;
1643
1644end_user:
1645	user_access_end();
1646end:
1647	kvfree(relocs);
1648	err = -EFAULT;
1649err:
1650	while (i--) {
1651		relocs = u64_to_ptr(typeof(*relocs), eb->exec[i].relocs_ptr);
1652		if (eb->exec[i].relocation_count)
1653			kvfree(relocs);
1654	}
1655	return err;
1656}
1657
1658static int eb_prefault_relocations(const struct i915_execbuffer *eb)
1659{
1660	const unsigned int count = eb->buffer_count;
1661	unsigned int i;
1662
1663	if (unlikely(i915_modparams.prefault_disable))
1664		return 0;
1665
1666	for (i = 0; i < count; i++) {
1667		int err;
1668
1669		err = check_relocations(&eb->exec[i]);
1670		if (err)
1671			return err;
1672	}
1673
1674	return 0;
1675}
1676
1677static noinline int eb_relocate_slow(struct i915_execbuffer *eb)
1678{
1679	struct drm_device *dev = &eb->i915->drm;
1680	bool have_copy = false;
1681	struct i915_vma *vma;
1682	int err = 0;
1683
1684repeat:
1685	if (signal_pending(current)) {
1686		err = -ERESTARTSYS;
1687		goto out;
1688	}
1689
1690	/* We may process another execbuffer during the unlock... */
1691	eb_reset_vmas(eb);
1692	mutex_unlock(&dev->struct_mutex);
1693
1694	/*
1695	 * We take 3 passes through the slowpatch.
1696	 *
1697	 * 1 - we try to just prefault all the user relocation entries and
1698	 * then attempt to reuse the atomic pagefault disabled fast path again.
1699	 *
1700	 * 2 - we copy the user entries to a local buffer here outside of the
1701	 * local and allow ourselves to wait upon any rendering before
1702	 * relocations
1703	 *
1704	 * 3 - we already have a local copy of the relocation entries, but
1705	 * were interrupted (EAGAIN) whilst waiting for the objects, try again.
1706	 */
1707	if (!err) {
1708		err = eb_prefault_relocations(eb);
1709	} else if (!have_copy) {
1710		err = eb_copy_relocations(eb);
1711		have_copy = err == 0;
1712	} else {
1713		cond_resched();
1714		err = 0;
1715	}
1716	if (err) {
1717		mutex_lock(&dev->struct_mutex);
1718		goto out;
1719	}
1720
1721	/* A frequent cause for EAGAIN are currently unavailable client pages */
1722	flush_workqueue(eb->i915->mm.userptr_wq);
1723
1724	err = i915_mutex_lock_interruptible(dev);
1725	if (err) {
1726		mutex_lock(&dev->struct_mutex);
1727		goto out;
1728	}
1729
1730	/* reacquire the objects */
1731	err = eb_lookup_vmas(eb);
1732	if (err)
1733		goto err;
1734
1735	GEM_BUG_ON(!eb->batch);
1736
1737	list_for_each_entry(vma, &eb->relocs, reloc_link) {
1738		if (!have_copy) {
1739			pagefault_disable();
1740			err = eb_relocate_vma(eb, vma);
1741			pagefault_enable();
1742			if (err)
1743				goto repeat;
1744		} else {
1745			err = eb_relocate_vma_slow(eb, vma);
1746			if (err)
1747				goto err;
1748		}
1749	}
1750
1751	/*
1752	 * Leave the user relocations as are, this is the painfully slow path,
1753	 * and we want to avoid the complication of dropping the lock whilst
1754	 * having buffers reserved in the aperture and so causing spurious
1755	 * ENOSPC for random operations.
1756	 */
1757
1758err:
1759	if (err == -EAGAIN)
1760		goto repeat;
1761
1762out:
1763	if (have_copy) {
1764		const unsigned int count = eb->buffer_count;
1765		unsigned int i;
1766
1767		for (i = 0; i < count; i++) {
1768			const struct drm_i915_gem_exec_object2 *entry =
1769				&eb->exec[i];
1770			struct drm_i915_gem_relocation_entry *relocs;
1771
1772			if (!entry->relocation_count)
1773				continue;
1774
1775			relocs = u64_to_ptr(typeof(*relocs), entry->relocs_ptr);
1776			kvfree(relocs);
1777		}
1778	}
1779
1780	return err;
1781}
1782
1783static int eb_relocate(struct i915_execbuffer *eb)
1784{
1785	if (eb_lookup_vmas(eb))
1786		goto slow;
1787
1788	/* The objects are in their final locations, apply the relocations. */
1789	if (eb->args->flags & __EXEC_HAS_RELOC) {
1790		struct i915_vma *vma;
1791
1792		list_for_each_entry(vma, &eb->relocs, reloc_link) {
1793			if (eb_relocate_vma(eb, vma))
1794				goto slow;
1795		}
1796	}
1797
1798	return 0;
1799
1800slow:
1801	return eb_relocate_slow(eb);
1802}
1803
1804static int eb_move_to_gpu(struct i915_execbuffer *eb)
1805{
1806	const unsigned int count = eb->buffer_count;
1807	struct ww_acquire_ctx acquire;
1808	unsigned int i;
1809	int err = 0;
1810
1811	ww_acquire_init(&acquire, &reservation_ww_class);
1812
1813	for (i = 0; i < count; i++) {
1814		struct i915_vma *vma = eb->vma[i];
1815
1816		err = ww_mutex_lock_interruptible(&vma->resv->lock, &acquire);
1817		if (!err)
1818			continue;
1819
1820		GEM_BUG_ON(err == -EALREADY); /* No duplicate vma */
1821
1822		if (err == -EDEADLK) {
1823			GEM_BUG_ON(i == 0);
1824			do {
1825				int j = i - 1;
1826
1827				ww_mutex_unlock(&eb->vma[j]->resv->lock);
1828
1829				swap(eb->flags[i], eb->flags[j]);
1830				swap(eb->vma[i],  eb->vma[j]);
1831				eb->vma[i]->exec_flags = &eb->flags[i];
1832			} while (--i);
1833			GEM_BUG_ON(vma != eb->vma[0]);
1834			vma->exec_flags = &eb->flags[0];
1835
1836			err = ww_mutex_lock_slow_interruptible(&vma->resv->lock,
1837							       &acquire);
1838		}
1839		if (err)
1840			break;
1841	}
1842	ww_acquire_done(&acquire);
1843
1844	while (i--) {
1845		unsigned int flags = eb->flags[i];
1846		struct i915_vma *vma = eb->vma[i];
1847		struct drm_i915_gem_object *obj = vma->obj;
1848
1849		assert_vma_held(vma);
1850
1851		if (flags & EXEC_OBJECT_CAPTURE) {
1852			struct i915_capture_list *capture;
1853
1854			capture = kmalloc(sizeof(*capture), GFP_KERNEL);
1855			if (capture) {
1856				capture->next = eb->request->capture_list;
1857				capture->vma = vma;
1858				eb->request->capture_list = capture;
1859			}
1860		}
1861
1862		/*
1863		 * If the GPU is not _reading_ through the CPU cache, we need
1864		 * to make sure that any writes (both previous GPU writes from
1865		 * before a change in snooping levels and normal CPU writes)
1866		 * caught in that cache are flushed to main memory.
1867		 *
1868		 * We want to say
1869		 *   obj->cache_dirty &&
1870		 *   !(obj->cache_coherent & I915_BO_CACHE_COHERENT_FOR_READ)
1871		 * but gcc's optimiser doesn't handle that as well and emits
1872		 * two jumps instead of one. Maybe one day...
1873		 */
1874		if (unlikely(obj->cache_dirty & ~obj->cache_coherent)) {
1875			if (i915_gem_clflush_object(obj, 0))
1876				flags &= ~EXEC_OBJECT_ASYNC;
1877		}
1878
1879		if (err == 0 && !(flags & EXEC_OBJECT_ASYNC)) {
1880			err = i915_request_await_object
1881				(eb->request, obj, flags & EXEC_OBJECT_WRITE);
1882		}
1883
1884		if (err == 0)
1885			err = i915_vma_move_to_active(vma, eb->request, flags);
1886
1887		i915_vma_unlock(vma);
1888
1889		__eb_unreserve_vma(vma, flags);
1890		vma->exec_flags = NULL;
1891
1892		if (unlikely(flags & __EXEC_OBJECT_HAS_REF))
1893			i915_vma_put(vma);
1894	}
1895	ww_acquire_fini(&acquire);
1896
1897	if (unlikely(err))
1898		goto err_skip;
1899
1900	eb->exec = NULL;
1901
1902	/* Unconditionally flush any chipset caches (for streaming writes). */
1903	intel_gt_chipset_flush(eb->engine->gt);
1904	return 0;
1905
1906err_skip:
1907	i915_request_skip(eb->request, err);
1908	return err;
1909}
1910
1911static bool i915_gem_check_execbuffer(struct drm_i915_gem_execbuffer2 *exec)
1912{
1913	if (exec->flags & __I915_EXEC_ILLEGAL_FLAGS)
1914		return false;
1915
1916	/* Kernel clipping was a DRI1 misfeature */
1917	if (!(exec->flags & I915_EXEC_FENCE_ARRAY)) {
1918		if (exec->num_cliprects || exec->cliprects_ptr)
1919			return false;
1920	}
1921
1922	if (exec->DR4 == 0xffffffff) {
1923		DRM_DEBUG("UXA submitting garbage DR4, fixing up\n");
1924		exec->DR4 = 0;
1925	}
1926	if (exec->DR1 || exec->DR4)
1927		return false;
1928
1929	if ((exec->batch_start_offset | exec->batch_len) & 0x7)
1930		return false;
1931
1932	return true;
1933}
1934
1935static int i915_reset_gen7_sol_offsets(struct i915_request *rq)
1936{
1937	u32 *cs;
1938	int i;
1939
1940	if (!IS_GEN(rq->i915, 7) || rq->engine->id != RCS0) {
1941		DRM_DEBUG("sol reset is gen7/rcs only\n");
1942		return -EINVAL;
1943	}
1944
1945	cs = intel_ring_begin(rq, 4 * 2 + 2);
1946	if (IS_ERR(cs))
1947		return PTR_ERR(cs);
1948
1949	*cs++ = MI_LOAD_REGISTER_IMM(4);
1950	for (i = 0; i < 4; i++) {
1951		*cs++ = i915_mmio_reg_offset(GEN7_SO_WRITE_OFFSET(i));
1952		*cs++ = 0;
1953	}
1954	*cs++ = MI_NOOP;
1955	intel_ring_advance(rq, cs);
1956
1957	return 0;
1958}
1959
1960static struct i915_vma *
1961shadow_batch_pin(struct i915_execbuffer *eb, struct drm_i915_gem_object *obj)
1962{
1963	struct drm_i915_private *dev_priv = eb->i915;
1964	struct i915_vma * const vma = *eb->vma;
1965	struct i915_address_space *vm;
1966	u64 flags;
1967
1968	/*
1969	 * PPGTT backed shadow buffers must be mapped RO, to prevent
1970	 * post-scan tampering
1971	 */
1972	if (CMDPARSER_USES_GGTT(dev_priv)) {
1973		flags = PIN_GLOBAL;
1974		vm = &dev_priv->ggtt.vm;
1975	} else if (vma->vm->has_read_only) {
1976		flags = PIN_USER;
1977		vm = vma->vm;
1978		i915_gem_object_set_readonly(obj);
1979	} else {
1980		DRM_DEBUG("Cannot prevent post-scan tampering without RO capable vm\n");
1981		return ERR_PTR(-EINVAL);
1982	}
1983
1984	return i915_gem_object_pin(obj, vm, NULL, 0, 0, flags);
1985}
1986
1987static struct i915_vma *eb_parse(struct i915_execbuffer *eb)
1988{
1989	struct intel_engine_pool_node *pool;
1990	struct i915_vma *vma;
1991	u64 batch_start;
1992	u64 shadow_batch_start;
1993	int err;
1994
1995	pool = intel_engine_pool_get(&eb->engine->pool, eb->batch_len);
1996	if (IS_ERR(pool))
1997		return ERR_CAST(pool);
1998
1999	vma = shadow_batch_pin(eb, pool->obj);
2000	if (IS_ERR(vma))
2001		goto err;
2002
2003	batch_start = gen8_canonical_addr(eb->batch->node.start) +
2004		      eb->batch_start_offset;
2005
2006	shadow_batch_start = gen8_canonical_addr(vma->node.start);
2007
2008	err = intel_engine_cmd_parser(eb->gem_context,
2009				      eb->engine,
2010				      eb->batch->obj,
2011				      batch_start,
2012				      eb->batch_start_offset,
2013				      eb->batch_len,
2014				      pool->obj,
2015				      shadow_batch_start);
2016
2017	if (err) {
2018		i915_vma_unpin(vma);
2019
2020		/*
2021		 * Unsafe GGTT-backed buffers can still be submitted safely
2022		 * as non-secure.
2023		 * For PPGTT backing however, we have no choice but to forcibly
2024		 * reject unsafe buffers
2025		 */
2026		if (CMDPARSER_USES_GGTT(eb->i915) && (err == -EACCES))
2027			/* Execute original buffer non-secure */
2028			vma = NULL;
2029		else
2030			vma = ERR_PTR(err);
2031		goto err;
2032	}
2033
2034	eb->vma[eb->buffer_count] = i915_vma_get(vma);
2035	eb->flags[eb->buffer_count] =
2036		__EXEC_OBJECT_HAS_PIN | __EXEC_OBJECT_HAS_REF;
2037	vma->exec_flags = &eb->flags[eb->buffer_count];
2038	eb->buffer_count++;
2039
2040	eb->batch_start_offset = 0;
2041	eb->batch = vma;
2042
2043	if (CMDPARSER_USES_GGTT(eb->i915))
2044		eb->batch_flags |= I915_DISPATCH_SECURE;
2045
2046	/* eb->batch_len unchanged */
2047
2048	vma->private = pool;
2049	return vma;
2050
2051err:
2052	intel_engine_pool_put(pool);
2053	return vma;
2054}
2055
2056static void
2057add_to_client(struct i915_request *rq, struct drm_file *file)
2058{
2059	struct drm_i915_file_private *file_priv = file->driver_priv;
2060
2061	rq->file_priv = file_priv;
2062
2063	spin_lock(&file_priv->mm.lock);
2064	list_add_tail(&rq->client_link, &file_priv->mm.request_list);
2065	spin_unlock(&file_priv->mm.lock);
2066}
2067
2068static int eb_submit(struct i915_execbuffer *eb)
2069{
2070	int err;
2071
2072	err = eb_move_to_gpu(eb);
2073	if (err)
2074		return err;
2075
2076	if (eb->args->flags & I915_EXEC_GEN7_SOL_RESET) {
2077		err = i915_reset_gen7_sol_offsets(eb->request);
2078		if (err)
2079			return err;
2080	}
2081
2082	/*
2083	 * After we completed waiting for other engines (using HW semaphores)
2084	 * then we can signal that this request/batch is ready to run. This
2085	 * allows us to determine if the batch is still waiting on the GPU
2086	 * or actually running by checking the breadcrumb.
2087	 */
2088	if (eb->engine->emit_init_breadcrumb) {
2089		err = eb->engine->emit_init_breadcrumb(eb->request);
2090		if (err)
2091			return err;
2092	}
2093
2094	err = eb->engine->emit_bb_start(eb->request,
2095					eb->batch->node.start +
2096					eb->batch_start_offset,
2097					eb->batch_len,
2098					eb->batch_flags);
2099	if (err)
2100		return err;
2101
2102	return 0;
2103}
2104
2105static int num_vcs_engines(const struct drm_i915_private *i915)
2106{
2107	return hweight64(INTEL_INFO(i915)->engine_mask &
2108			 GENMASK_ULL(VCS0 + I915_MAX_VCS - 1, VCS0));
2109}
2110
2111/*
2112 * Find one BSD ring to dispatch the corresponding BSD command.
2113 * The engine index is returned.
2114 */
2115static unsigned int
2116gen8_dispatch_bsd_engine(struct drm_i915_private *dev_priv,
2117			 struct drm_file *file)
2118{
2119	struct drm_i915_file_private *file_priv = file->driver_priv;
2120
2121	/* Check whether the file_priv has already selected one ring. */
2122	if ((int)file_priv->bsd_engine < 0)
2123		file_priv->bsd_engine =
2124			get_random_int() % num_vcs_engines(dev_priv);
2125
2126	return file_priv->bsd_engine;
2127}
2128
2129static const enum intel_engine_id user_ring_map[] = {
2130	[I915_EXEC_DEFAULT]	= RCS0,
2131	[I915_EXEC_RENDER]	= RCS0,
2132	[I915_EXEC_BLT]		= BCS0,
2133	[I915_EXEC_BSD]		= VCS0,
2134	[I915_EXEC_VEBOX]	= VECS0
2135};
2136
2137static struct i915_request *eb_throttle(struct intel_context *ce)
2138{
2139	struct intel_ring *ring = ce->ring;
2140	struct intel_timeline *tl = ce->timeline;
2141	struct i915_request *rq;
2142
2143	/*
2144	 * Completely unscientific finger-in-the-air estimates for suitable
2145	 * maximum user request size (to avoid blocking) and then backoff.
2146	 */
2147	if (intel_ring_update_space(ring) >= PAGE_SIZE)
2148		return NULL;
2149
2150	/*
2151	 * Find a request that after waiting upon, there will be at least half
2152	 * the ring available. The hysteresis allows us to compete for the
2153	 * shared ring and should mean that we sleep less often prior to
2154	 * claiming our resources, but not so long that the ring completely
2155	 * drains before we can submit our next request.
2156	 */
2157	list_for_each_entry(rq, &tl->requests, link) {
2158		if (rq->ring != ring)
2159			continue;
2160
2161		if (__intel_ring_space(rq->postfix,
2162				       ring->emit, ring->size) > ring->size / 2)
2163			break;
2164	}
2165	if (&rq->link == &tl->requests)
2166		return NULL; /* weird, we will check again later for real */
2167
2168	return i915_request_get(rq);
2169}
2170
2171static int
2172__eb_pin_context(struct i915_execbuffer *eb, struct intel_context *ce)
2173{
2174	int err;
2175
2176	if (likely(atomic_inc_not_zero(&ce->pin_count)))
2177		return 0;
2178
2179	err = mutex_lock_interruptible(&eb->i915->drm.struct_mutex);
2180	if (err)
2181		return err;
2182
2183	err = __intel_context_do_pin(ce);
2184	mutex_unlock(&eb->i915->drm.struct_mutex);
2185
2186	return err;
2187}
2188
2189static void
2190__eb_unpin_context(struct i915_execbuffer *eb, struct intel_context *ce)
2191{
2192	if (likely(atomic_add_unless(&ce->pin_count, -1, 1)))
2193		return;
2194
2195	mutex_lock(&eb->i915->drm.struct_mutex);
2196	intel_context_unpin(ce);
2197	mutex_unlock(&eb->i915->drm.struct_mutex);
2198}
2199
2200static int __eb_pin_engine(struct i915_execbuffer *eb, struct intel_context *ce)
2201{
2202	struct intel_timeline *tl;
2203	struct i915_request *rq;
2204	int err;
2205
2206	/*
2207	 * ABI: Before userspace accesses the GPU (e.g. execbuffer), report
2208	 * EIO if the GPU is already wedged.
2209	 */
2210	err = intel_gt_terminally_wedged(ce->engine->gt);
2211	if (err)
2212		return err;
2213
2214	/*
2215	 * Pinning the contexts may generate requests in order to acquire
2216	 * GGTT space, so do this first before we reserve a seqno for
2217	 * ourselves.
2218	 */
2219	err = __eb_pin_context(eb, ce);
2220	if (err)
2221		return err;
2222
2223	/*
2224	 * Take a local wakeref for preparing to dispatch the execbuf as
2225	 * we expect to access the hardware fairly frequently in the
2226	 * process, and require the engine to be kept awake between accesses.
2227	 * Upon dispatch, we acquire another prolonged wakeref that we hold
2228	 * until the timeline is idle, which in turn releases the wakeref
2229	 * taken on the engine, and the parent device.
2230	 */
2231	tl = intel_context_timeline_lock(ce);
2232	if (IS_ERR(tl)) {
2233		err = PTR_ERR(tl);
2234		goto err_unpin;
2235	}
2236
2237	intel_context_enter(ce);
2238	rq = eb_throttle(ce);
2239
2240	intel_context_timeline_unlock(tl);
2241
2242	if (rq) {
2243		if (i915_request_wait(rq,
2244				      I915_WAIT_INTERRUPTIBLE,
2245				      MAX_SCHEDULE_TIMEOUT) < 0) {
2246			i915_request_put(rq);
2247			err = -EINTR;
2248			goto err_exit;
2249		}
2250
2251		i915_request_put(rq);
2252	}
2253
2254	eb->engine = ce->engine;
2255	eb->context = ce;
2256	return 0;
2257
2258err_exit:
2259	mutex_lock(&tl->mutex);
2260	intel_context_exit(ce);
2261	intel_context_timeline_unlock(tl);
2262err_unpin:
2263	__eb_unpin_context(eb, ce);
2264	return err;
2265}
2266
2267static void eb_unpin_engine(struct i915_execbuffer *eb)
2268{
2269	struct intel_context *ce = eb->context;
2270	struct intel_timeline *tl = ce->timeline;
2271
2272	mutex_lock(&tl->mutex);
2273	intel_context_exit(ce);
2274	mutex_unlock(&tl->mutex);
2275
2276	__eb_unpin_context(eb, ce);
2277}
2278
2279static unsigned int
2280eb_select_legacy_ring(struct i915_execbuffer *eb,
2281		      struct drm_file *file,
2282		      struct drm_i915_gem_execbuffer2 *args)
2283{
2284	struct drm_i915_private *i915 = eb->i915;
2285	unsigned int user_ring_id = args->flags & I915_EXEC_RING_MASK;
2286
2287	if (user_ring_id != I915_EXEC_BSD &&
2288	    (args->flags & I915_EXEC_BSD_MASK)) {
2289		DRM_DEBUG("execbuf with non bsd ring but with invalid "
2290			  "bsd dispatch flags: %d\n", (int)(args->flags));
2291		return -1;
2292	}
2293
2294	if (user_ring_id == I915_EXEC_BSD && num_vcs_engines(i915) > 1) {
2295		unsigned int bsd_idx = args->flags & I915_EXEC_BSD_MASK;
2296
2297		if (bsd_idx == I915_EXEC_BSD_DEFAULT) {
2298			bsd_idx = gen8_dispatch_bsd_engine(i915, file);
2299		} else if (bsd_idx >= I915_EXEC_BSD_RING1 &&
2300			   bsd_idx <= I915_EXEC_BSD_RING2) {
2301			bsd_idx >>= I915_EXEC_BSD_SHIFT;
2302			bsd_idx--;
2303		} else {
2304			DRM_DEBUG("execbuf with unknown bsd ring: %u\n",
2305				  bsd_idx);
2306			return -1;
2307		}
2308
2309		return _VCS(bsd_idx);
2310	}
2311
2312	if (user_ring_id >= ARRAY_SIZE(user_ring_map)) {
2313		DRM_DEBUG("execbuf with unknown ring: %u\n", user_ring_id);
2314		return -1;
2315	}
2316
2317	return user_ring_map[user_ring_id];
2318}
2319
2320static int
2321eb_pin_engine(struct i915_execbuffer *eb,
2322	      struct drm_file *file,
2323	      struct drm_i915_gem_execbuffer2 *args)
2324{
2325	struct intel_context *ce;
2326	unsigned int idx;
2327	int err;
2328
2329	if (i915_gem_context_user_engines(eb->gem_context))
2330		idx = args->flags & I915_EXEC_RING_MASK;
2331	else
2332		idx = eb_select_legacy_ring(eb, file, args);
2333
2334	ce = i915_gem_context_get_engine(eb->gem_context, idx);
2335	if (IS_ERR(ce))
2336		return PTR_ERR(ce);
2337
2338	err = __eb_pin_engine(eb, ce);
2339	intel_context_put(ce);
2340
2341	return err;
2342}
2343
2344static void
2345__free_fence_array(struct drm_syncobj **fences, unsigned int n)
2346{
2347	while (n--)
2348		drm_syncobj_put(ptr_mask_bits(fences[n], 2));
2349	kvfree(fences);
2350}
2351
2352static struct drm_syncobj **
2353get_fence_array(struct drm_i915_gem_execbuffer2 *args,
2354		struct drm_file *file)
2355{
2356	const unsigned long nfences = args->num_cliprects;
2357	struct drm_i915_gem_exec_fence __user *user;
2358	struct drm_syncobj **fences;
2359	unsigned long n;
2360	int err;
2361
2362	if (!(args->flags & I915_EXEC_FENCE_ARRAY))
2363		return NULL;
2364
2365	/* Check multiplication overflow for access_ok() and kvmalloc_array() */
2366	BUILD_BUG_ON(sizeof(size_t) > sizeof(unsigned long));
2367	if (nfences > min_t(unsigned long,
2368			    ULONG_MAX / sizeof(*user),
2369			    SIZE_MAX / sizeof(*fences)))
2370		return ERR_PTR(-EINVAL);
2371
2372	user = u64_to_user_ptr(args->cliprects_ptr);
2373	if (!access_ok(user, nfences * sizeof(*user)))
2374		return ERR_PTR(-EFAULT);
2375
2376	fences = kvmalloc_array(nfences, sizeof(*fences),
2377				__GFP_NOWARN | GFP_KERNEL);
2378	if (!fences)
2379		return ERR_PTR(-ENOMEM);
2380
2381	for (n = 0; n < nfences; n++) {
2382		struct drm_i915_gem_exec_fence fence;
2383		struct drm_syncobj *syncobj;
2384
2385		if (__copy_from_user(&fence, user++, sizeof(fence))) {
2386			err = -EFAULT;
2387			goto err;
2388		}
2389
2390		if (fence.flags & __I915_EXEC_FENCE_UNKNOWN_FLAGS) {
2391			err = -EINVAL;
2392			goto err;
2393		}
2394
2395		syncobj = drm_syncobj_find(file, fence.handle);
2396		if (!syncobj) {
2397			DRM_DEBUG("Invalid syncobj handle provided\n");
2398			err = -ENOENT;
2399			goto err;
2400		}
2401
2402		BUILD_BUG_ON(~(ARCH_KMALLOC_MINALIGN - 1) &
2403			     ~__I915_EXEC_FENCE_UNKNOWN_FLAGS);
2404
2405		fences[n] = ptr_pack_bits(syncobj, fence.flags, 2);
2406	}
2407
2408	return fences;
2409
2410err:
2411	__free_fence_array(fences, n);
2412	return ERR_PTR(err);
2413}
2414
2415static void
2416put_fence_array(struct drm_i915_gem_execbuffer2 *args,
2417		struct drm_syncobj **fences)
2418{
2419	if (fences)
2420		__free_fence_array(fences, args->num_cliprects);
2421}
2422
2423static int
2424await_fence_array(struct i915_execbuffer *eb,
2425		  struct drm_syncobj **fences)
2426{
2427	const unsigned int nfences = eb->args->num_cliprects;
2428	unsigned int n;
2429	int err;
2430
2431	for (n = 0; n < nfences; n++) {
2432		struct drm_syncobj *syncobj;
2433		struct dma_fence *fence;
2434		unsigned int flags;
2435
2436		syncobj = ptr_unpack_bits(fences[n], &flags, 2);
2437		if (!(flags & I915_EXEC_FENCE_WAIT))
2438			continue;
2439
2440		fence = drm_syncobj_fence_get(syncobj);
2441		if (!fence)
2442			return -EINVAL;
2443
2444		err = i915_request_await_dma_fence(eb->request, fence);
2445		dma_fence_put(fence);
2446		if (err < 0)
2447			return err;
2448	}
2449
2450	return 0;
2451}
2452
2453static void
2454signal_fence_array(struct i915_execbuffer *eb,
2455		   struct drm_syncobj **fences)
2456{
2457	const unsigned int nfences = eb->args->num_cliprects;
2458	struct dma_fence * const fence = &eb->request->fence;
2459	unsigned int n;
2460
2461	for (n = 0; n < nfences; n++) {
2462		struct drm_syncobj *syncobj;
2463		unsigned int flags;
2464
2465		syncobj = ptr_unpack_bits(fences[n], &flags, 2);
2466		if (!(flags & I915_EXEC_FENCE_SIGNAL))
2467			continue;
2468
2469		drm_syncobj_replace_fence(syncobj, fence);
2470	}
2471}
2472
2473static int
2474i915_gem_do_execbuffer(struct drm_device *dev,
2475		       struct drm_file *file,
2476		       struct drm_i915_gem_execbuffer2 *args,
2477		       struct drm_i915_gem_exec_object2 *exec,
2478		       struct drm_syncobj **fences)
2479{
2480	struct drm_i915_private *i915 = to_i915(dev);
2481	struct i915_execbuffer eb;
2482	struct dma_fence *in_fence = NULL;
2483	struct dma_fence *exec_fence = NULL;
2484	struct sync_file *out_fence = NULL;
2485	int out_fence_fd = -1;
2486	int err;
2487
2488	BUILD_BUG_ON(__EXEC_INTERNAL_FLAGS & ~__I915_EXEC_ILLEGAL_FLAGS);
2489	BUILD_BUG_ON(__EXEC_OBJECT_INTERNAL_FLAGS &
2490		     ~__EXEC_OBJECT_UNKNOWN_FLAGS);
2491
2492	eb.i915 = i915;
2493	eb.file = file;
2494	eb.args = args;
2495	if (DBG_FORCE_RELOC || !(args->flags & I915_EXEC_NO_RELOC))
2496		args->flags |= __EXEC_HAS_RELOC;
2497
2498	eb.exec = exec;
2499	eb.vma = (struct i915_vma **)(exec + args->buffer_count + 1);
2500	eb.vma[0] = NULL;
2501	eb.flags = (unsigned int *)(eb.vma + args->buffer_count + 1);
2502
2503	eb.invalid_flags = __EXEC_OBJECT_UNKNOWN_FLAGS;
2504	reloc_cache_init(&eb.reloc_cache, eb.i915);
2505
2506	eb.buffer_count = args->buffer_count;
2507	eb.batch_start_offset = args->batch_start_offset;
2508	eb.batch_len = args->batch_len;
2509
2510	eb.batch_flags = 0;
2511	if (args->flags & I915_EXEC_SECURE) {
2512		if (INTEL_GEN(i915) >= 11)
2513			return -ENODEV;
2514
2515		/* Return -EPERM to trigger fallback code on old binaries. */
2516		if (!HAS_SECURE_BATCHES(i915))
2517			return -EPERM;
2518
2519		if (!drm_is_current_master(file) || !capable(CAP_SYS_ADMIN))
2520			return -EPERM;
2521
2522		eb.batch_flags |= I915_DISPATCH_SECURE;
2523	}
2524	if (args->flags & I915_EXEC_IS_PINNED)
2525		eb.batch_flags |= I915_DISPATCH_PINNED;
2526
2527	if (args->flags & I915_EXEC_FENCE_IN) {
2528		in_fence = sync_file_get_fence(lower_32_bits(args->rsvd2));
2529		if (!in_fence)
2530			return -EINVAL;
2531	}
2532
2533	if (args->flags & I915_EXEC_FENCE_SUBMIT) {
2534		if (in_fence) {
2535			err = -EINVAL;
2536			goto err_in_fence;
2537		}
2538
2539		exec_fence = sync_file_get_fence(lower_32_bits(args->rsvd2));
2540		if (!exec_fence) {
2541			err = -EINVAL;
2542			goto err_in_fence;
2543		}
2544	}
2545
2546	if (args->flags & I915_EXEC_FENCE_OUT) {
2547		out_fence_fd = get_unused_fd_flags(O_CLOEXEC);
2548		if (out_fence_fd < 0) {
2549			err = out_fence_fd;
2550			goto err_exec_fence;
2551		}
2552	}
2553
2554	err = eb_create(&eb);
2555	if (err)
2556		goto err_out_fence;
2557
2558	GEM_BUG_ON(!eb.lut_size);
2559
2560	err = eb_select_context(&eb);
2561	if (unlikely(err))
2562		goto err_destroy;
2563
2564	err = eb_pin_engine(&eb, file, args);
2565	if (unlikely(err))
2566		goto err_context;
2567
2568	err = i915_mutex_lock_interruptible(dev);
2569	if (err)
2570		goto err_engine;
2571
2572	err = eb_relocate(&eb);
2573	if (err) {
2574		/*
2575		 * If the user expects the execobject.offset and
2576		 * reloc.presumed_offset to be an exact match,
2577		 * as for using NO_RELOC, then we cannot update
2578		 * the execobject.offset until we have completed
2579		 * relocation.
2580		 */
2581		args->flags &= ~__EXEC_HAS_RELOC;
2582		goto err_vma;
2583	}
2584
2585	if (unlikely(*eb.batch->exec_flags & EXEC_OBJECT_WRITE)) {
2586		DRM_DEBUG("Attempting to use self-modifying batch buffer\n");
2587		err = -EINVAL;
2588		goto err_vma;
2589	}
2590	if (eb.batch_start_offset > eb.batch->size ||
2591	    eb.batch_len > eb.batch->size - eb.batch_start_offset) {
2592		DRM_DEBUG("Attempting to use out-of-bounds batch\n");
2593		err = -EINVAL;
2594		goto err_vma;
2595	}
2596
2597	if (eb.batch_len == 0)
2598		eb.batch_len = eb.batch->size - eb.batch_start_offset;
2599
2600	if (eb_use_cmdparser(&eb)) {
2601		struct i915_vma *vma;
2602
2603		vma = eb_parse(&eb);
2604		if (IS_ERR(vma)) {
2605			err = PTR_ERR(vma);
2606			goto err_vma;
2607		}
2608	}
2609
2610	/*
2611	 * snb/ivb/vlv conflate the "batch in ppgtt" bit with the "non-secure
2612	 * batch" bit. Hence we need to pin secure batches into the global gtt.
2613	 * hsw should have this fixed, but bdw mucks it up again. */
2614	if (eb.batch_flags & I915_DISPATCH_SECURE) {
2615		struct i915_vma *vma;
2616
2617		/*
2618		 * So on first glance it looks freaky that we pin the batch here
2619		 * outside of the reservation loop. But:
2620		 * - The batch is already pinned into the relevant ppgtt, so we
2621		 *   already have the backing storage fully allocated.
2622		 * - No other BO uses the global gtt (well contexts, but meh),
2623		 *   so we don't really have issues with multiple objects not
2624		 *   fitting due to fragmentation.
2625		 * So this is actually safe.
2626		 */
2627		vma = i915_gem_object_ggtt_pin(eb.batch->obj, NULL, 0, 0, 0);
2628		if (IS_ERR(vma)) {
2629			err = PTR_ERR(vma);
2630			goto err_vma;
2631		}
2632
2633		eb.batch = vma;
2634	}
2635
2636	/* All GPU relocation batches must be submitted prior to the user rq */
2637	GEM_BUG_ON(eb.reloc_cache.rq);
2638
2639	/* Allocate a request for this batch buffer nice and early. */
2640	eb.request = i915_request_create(eb.context);
2641	if (IS_ERR(eb.request)) {
2642		err = PTR_ERR(eb.request);
2643		goto err_batch_unpin;
2644	}
2645
2646	if (in_fence) {
2647		err = i915_request_await_dma_fence(eb.request, in_fence);
2648		if (err < 0)
2649			goto err_request;
2650	}
2651
2652	if (exec_fence) {
2653		err = i915_request_await_execution(eb.request, exec_fence,
2654						   eb.engine->bond_execute);
2655		if (err < 0)
2656			goto err_request;
2657	}
2658
2659	if (fences) {
2660		err = await_fence_array(&eb, fences);
2661		if (err)
2662			goto err_request;
2663	}
2664
2665	if (out_fence_fd != -1) {
2666		out_fence = sync_file_create(&eb.request->fence);
2667		if (!out_fence) {
2668			err = -ENOMEM;
2669			goto err_request;
2670		}
2671	}
2672
2673	/*
2674	 * Whilst this request exists, batch_obj will be on the
2675	 * active_list, and so will hold the active reference. Only when this
2676	 * request is retired will the the batch_obj be moved onto the
2677	 * inactive_list and lose its active reference. Hence we do not need
2678	 * to explicitly hold another reference here.
2679	 */
2680	eb.request->batch = eb.batch;
2681	if (eb.batch->private)
2682		intel_engine_pool_mark_active(eb.batch->private, eb.request);
2683
2684	trace_i915_request_queue(eb.request, eb.batch_flags);
2685	err = eb_submit(&eb);
2686err_request:
2687	add_to_client(eb.request, file);
2688	i915_request_add(eb.request);
2689
2690	if (fences)
2691		signal_fence_array(&eb, fences);
2692
2693	if (out_fence) {
2694		if (err == 0) {
2695			fd_install(out_fence_fd, out_fence->file);
2696			args->rsvd2 &= GENMASK_ULL(31, 0); /* keep in-fence */
2697			args->rsvd2 |= (u64)out_fence_fd << 32;
2698			out_fence_fd = -1;
2699		} else {
2700			fput(out_fence->file);
2701		}
2702	}
2703
2704err_batch_unpin:
2705	if (eb.batch_flags & I915_DISPATCH_SECURE)
2706		i915_vma_unpin(eb.batch);
2707	if (eb.batch->private)
2708		intel_engine_pool_put(eb.batch->private);
2709err_vma:
2710	if (eb.exec)
2711		eb_release_vmas(&eb);
2712	mutex_unlock(&dev->struct_mutex);
2713err_engine:
2714	eb_unpin_engine(&eb);
2715err_context:
2716	i915_gem_context_put(eb.gem_context);
2717err_destroy:
2718	eb_destroy(&eb);
2719err_out_fence:
2720	if (out_fence_fd != -1)
2721		put_unused_fd(out_fence_fd);
2722err_exec_fence:
2723	dma_fence_put(exec_fence);
2724err_in_fence:
2725	dma_fence_put(in_fence);
2726	return err;
2727}
2728
2729static size_t eb_element_size(void)
2730{
2731	return (sizeof(struct drm_i915_gem_exec_object2) +
2732		sizeof(struct i915_vma *) +
2733		sizeof(unsigned int));
2734}
2735
2736static bool check_buffer_count(size_t count)
2737{
2738	const size_t sz = eb_element_size();
2739
2740	/*
2741	 * When using LUT_HANDLE, we impose a limit of INT_MAX for the lookup
2742	 * array size (see eb_create()). Otherwise, we can accept an array as
2743	 * large as can be addressed (though use large arrays at your peril)!
2744	 */
2745
2746	return !(count < 1 || count > INT_MAX || count > SIZE_MAX / sz - 1);
2747}
2748
2749/*
2750 * Legacy execbuffer just creates an exec2 list from the original exec object
2751 * list array and passes it to the real function.
2752 */
2753int
2754i915_gem_execbuffer_ioctl(struct drm_device *dev, void *data,
2755			  struct drm_file *file)
2756{
2757	struct drm_i915_gem_execbuffer *args = data;
2758	struct drm_i915_gem_execbuffer2 exec2;
2759	struct drm_i915_gem_exec_object *exec_list = NULL;
2760	struct drm_i915_gem_exec_object2 *exec2_list = NULL;
2761	const size_t count = args->buffer_count;
2762	unsigned int i;
2763	int err;
2764
2765	if (!check_buffer_count(count)) {
2766		DRM_DEBUG("execbuf2 with %zd buffers\n", count);
2767		return -EINVAL;
2768	}
2769
2770	exec2.buffers_ptr = args->buffers_ptr;
2771	exec2.buffer_count = args->buffer_count;
2772	exec2.batch_start_offset = args->batch_start_offset;
2773	exec2.batch_len = args->batch_len;
2774	exec2.DR1 = args->DR1;
2775	exec2.DR4 = args->DR4;
2776	exec2.num_cliprects = args->num_cliprects;
2777	exec2.cliprects_ptr = args->cliprects_ptr;
2778	exec2.flags = I915_EXEC_RENDER;
2779	i915_execbuffer2_set_context_id(exec2, 0);
2780
2781	if (!i915_gem_check_execbuffer(&exec2))
2782		return -EINVAL;
2783
2784	/* Copy in the exec list from userland */
2785	exec_list = kvmalloc_array(count, sizeof(*exec_list),
2786				   __GFP_NOWARN | GFP_KERNEL);
2787	exec2_list = kvmalloc_array(count + 1, eb_element_size(),
2788				    __GFP_NOWARN | GFP_KERNEL);
2789	if (exec_list == NULL || exec2_list == NULL) {
2790		DRM_DEBUG("Failed to allocate exec list for %d buffers\n",
2791			  args->buffer_count);
2792		kvfree(exec_list);
2793		kvfree(exec2_list);
2794		return -ENOMEM;
2795	}
2796	err = copy_from_user(exec_list,
2797			     u64_to_user_ptr(args->buffers_ptr),
2798			     sizeof(*exec_list) * count);
2799	if (err) {
2800		DRM_DEBUG("copy %d exec entries failed %d\n",
2801			  args->buffer_count, err);
2802		kvfree(exec_list);
2803		kvfree(exec2_list);
2804		return -EFAULT;
2805	}
2806
2807	for (i = 0; i < args->buffer_count; i++) {
2808		exec2_list[i].handle = exec_list[i].handle;
2809		exec2_list[i].relocation_count = exec_list[i].relocation_count;
2810		exec2_list[i].relocs_ptr = exec_list[i].relocs_ptr;
2811		exec2_list[i].alignment = exec_list[i].alignment;
2812		exec2_list[i].offset = exec_list[i].offset;
2813		if (INTEL_GEN(to_i915(dev)) < 4)
2814			exec2_list[i].flags = EXEC_OBJECT_NEEDS_FENCE;
2815		else
2816			exec2_list[i].flags = 0;
2817	}
2818
2819	err = i915_gem_do_execbuffer(dev, file, &exec2, exec2_list, NULL);
2820	if (exec2.flags & __EXEC_HAS_RELOC) {
2821		struct drm_i915_gem_exec_object __user *user_exec_list =
2822			u64_to_user_ptr(args->buffers_ptr);
2823
2824		/* Copy the new buffer offsets back to the user's exec list. */
2825		for (i = 0; i < args->buffer_count; i++) {
2826			if (!(exec2_list[i].offset & UPDATE))
2827				continue;
2828
2829			exec2_list[i].offset =
2830				gen8_canonical_addr(exec2_list[i].offset & PIN_OFFSET_MASK);
2831			exec2_list[i].offset &= PIN_OFFSET_MASK;
2832			if (__copy_to_user(&user_exec_list[i].offset,
2833					   &exec2_list[i].offset,
2834					   sizeof(user_exec_list[i].offset)))
2835				break;
2836		}
2837	}
2838
2839	kvfree(exec_list);
2840	kvfree(exec2_list);
2841	return err;
2842}
2843
2844int
2845i915_gem_execbuffer2_ioctl(struct drm_device *dev, void *data,
2846			   struct drm_file *file)
2847{
2848	struct drm_i915_gem_execbuffer2 *args = data;
2849	struct drm_i915_gem_exec_object2 *exec2_list;
2850	struct drm_syncobj **fences = NULL;
2851	const size_t count = args->buffer_count;
2852	int err;
2853
2854	if (!check_buffer_count(count)) {
2855		DRM_DEBUG("execbuf2 with %zd buffers\n", count);
2856		return -EINVAL;
2857	}
2858
2859	if (!i915_gem_check_execbuffer(args))
2860		return -EINVAL;
2861
2862	/* Allocate an extra slot for use by the command parser */
2863	exec2_list = kvmalloc_array(count + 1, eb_element_size(),
2864				    __GFP_NOWARN | GFP_KERNEL);
2865	if (exec2_list == NULL) {
2866		DRM_DEBUG("Failed to allocate exec list for %zd buffers\n",
2867			  count);
2868		return -ENOMEM;
2869	}
2870	if (copy_from_user(exec2_list,
2871			   u64_to_user_ptr(args->buffers_ptr),
2872			   sizeof(*exec2_list) * count)) {
2873		DRM_DEBUG("copy %zd exec entries failed\n", count);
2874		kvfree(exec2_list);
2875		return -EFAULT;
2876	}
2877
2878	if (args->flags & I915_EXEC_FENCE_ARRAY) {
2879		fences = get_fence_array(args, file);
2880		if (IS_ERR(fences)) {
2881			kvfree(exec2_list);
2882			return PTR_ERR(fences);
2883		}
2884	}
2885
2886	err = i915_gem_do_execbuffer(dev, file, args, exec2_list, fences);
2887
2888	/*
2889	 * Now that we have begun execution of the batchbuffer, we ignore
2890	 * any new error after this point. Also given that we have already
2891	 * updated the associated relocations, we try to write out the current
2892	 * object locations irrespective of any error.
2893	 */
2894	if (args->flags & __EXEC_HAS_RELOC) {
2895		struct drm_i915_gem_exec_object2 __user *user_exec_list =
2896			u64_to_user_ptr(args->buffers_ptr);
2897		unsigned int i;
2898
2899		/* Copy the new buffer offsets back to the user's exec list. */
2900		/*
2901		 * Note: count * sizeof(*user_exec_list) does not overflow,
2902		 * because we checked 'count' in check_buffer_count().
2903		 *
2904		 * And this range already got effectively checked earlier
2905		 * when we did the "copy_from_user()" above.
2906		 */
2907		if (!user_access_begin(user_exec_list, count * sizeof(*user_exec_list)))
2908			goto end;
2909
2910		for (i = 0; i < args->buffer_count; i++) {
2911			if (!(exec2_list[i].offset & UPDATE))
2912				continue;
2913
2914			exec2_list[i].offset =
2915				gen8_canonical_addr(exec2_list[i].offset & PIN_OFFSET_MASK);
2916			unsafe_put_user(exec2_list[i].offset,
2917					&user_exec_list[i].offset,
2918					end_user);
2919		}
2920end_user:
2921		user_access_end();
2922end:;
2923	}
2924
2925	args->flags &= ~__I915_EXEC_UNKNOWN_FLAGS;
2926	put_fence_array(args, fences);
2927	kvfree(exec2_list);
2928	return err;
2929}