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   1/*
   2 * Copyright © 2014 Intel Corporation
   3 *
   4 * Permission is hereby granted, free of charge, to any person obtaining a
   5 * copy of this software and associated documentation files (the "Software"),
   6 * to deal in the Software without restriction, including without limitation
   7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8 * and/or sell copies of the Software, and to permit persons to whom the
   9 * Software is furnished to do so, subject to the following conditions:
  10 *
  11 * The above copyright notice and this permission notice (including the next
  12 * paragraph) shall be included in all copies or substantial portions of the
  13 * Software.
  14 *
  15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  21 * IN THE SOFTWARE.
  22 *
  23 * Authors:
  24 *    Ben Widawsky <ben@bwidawsk.net>
  25 *    Michel Thierry <michel.thierry@intel.com>
  26 *    Thomas Daniel <thomas.daniel@intel.com>
  27 *    Oscar Mateo <oscar.mateo@intel.com>
  28 *
  29 */
  30
  31/**
  32 * DOC: Logical Rings, Logical Ring Contexts and Execlists
  33 *
  34 * Motivation:
  35 * GEN8 brings an expansion of the HW contexts: "Logical Ring Contexts".
  36 * These expanded contexts enable a number of new abilities, especially
  37 * "Execlists" (also implemented in this file).
  38 *
  39 * One of the main differences with the legacy HW contexts is that logical
  40 * ring contexts incorporate many more things to the context's state, like
  41 * PDPs or ringbuffer control registers:
  42 *
  43 * The reason why PDPs are included in the context is straightforward: as
  44 * PPGTTs (per-process GTTs) are actually per-context, having the PDPs
  45 * contained there mean you don't need to do a ppgtt->switch_mm yourself,
  46 * instead, the GPU will do it for you on the context switch.
  47 *
  48 * But, what about the ringbuffer control registers (head, tail, etc..)?
  49 * shouldn't we just need a set of those per engine command streamer? This is
  50 * where the name "Logical Rings" starts to make sense: by virtualizing the
  51 * rings, the engine cs shifts to a new "ring buffer" with every context
  52 * switch. When you want to submit a workload to the GPU you: A) choose your
  53 * context, B) find its appropriate virtualized ring, C) write commands to it
  54 * and then, finally, D) tell the GPU to switch to that context.
  55 *
  56 * Instead of the legacy MI_SET_CONTEXT, the way you tell the GPU to switch
  57 * to a contexts is via a context execution list, ergo "Execlists".
  58 *
  59 * LRC implementation:
  60 * Regarding the creation of contexts, we have:
  61 *
  62 * - One global default context.
  63 * - One local default context for each opened fd.
  64 * - One local extra context for each context create ioctl call.
  65 *
  66 * Now that ringbuffers belong per-context (and not per-engine, like before)
  67 * and that contexts are uniquely tied to a given engine (and not reusable,
  68 * like before) we need:
  69 *
  70 * - One ringbuffer per-engine inside each context.
  71 * - One backing object per-engine inside each context.
  72 *
  73 * The global default context starts its life with these new objects fully
  74 * allocated and populated. The local default context for each opened fd is
  75 * more complex, because we don't know at creation time which engine is going
  76 * to use them. To handle this, we have implemented a deferred creation of LR
  77 * contexts:
  78 *
  79 * The local context starts its life as a hollow or blank holder, that only
  80 * gets populated for a given engine once we receive an execbuffer. If later
  81 * on we receive another execbuffer ioctl for the same context but a different
  82 * engine, we allocate/populate a new ringbuffer and context backing object and
  83 * so on.
  84 *
  85 * Finally, regarding local contexts created using the ioctl call: as they are
  86 * only allowed with the render ring, we can allocate & populate them right
  87 * away (no need to defer anything, at least for now).
  88 *
  89 * Execlists implementation:
  90 * Execlists are the new method by which, on gen8+ hardware, workloads are
  91 * submitted for execution (as opposed to the legacy, ringbuffer-based, method).
  92 * This method works as follows:
  93 *
  94 * When a request is committed, its commands (the BB start and any leading or
  95 * trailing commands, like the seqno breadcrumbs) are placed in the ringbuffer
  96 * for the appropriate context. The tail pointer in the hardware context is not
  97 * updated at this time, but instead, kept by the driver in the ringbuffer
  98 * structure. A structure representing this request is added to a request queue
  99 * for the appropriate engine: this structure contains a copy of the context's
 100 * tail after the request was written to the ring buffer and a pointer to the
 101 * context itself.
 102 *
 103 * If the engine's request queue was empty before the request was added, the
 104 * queue is processed immediately. Otherwise the queue will be processed during
 105 * a context switch interrupt. In any case, elements on the queue will get sent
 106 * (in pairs) to the GPU's ExecLists Submit Port (ELSP, for short) with a
 107 * globally unique 20-bits submission ID.
 108 *
 109 * When execution of a request completes, the GPU updates the context status
 110 * buffer with a context complete event and generates a context switch interrupt.
 111 * During the interrupt handling, the driver examines the events in the buffer:
 112 * for each context complete event, if the announced ID matches that on the head
 113 * of the request queue, then that request is retired and removed from the queue.
 114 *
 115 * After processing, if any requests were retired and the queue is not empty
 116 * then a new execution list can be submitted. The two requests at the front of
 117 * the queue are next to be submitted but since a context may not occur twice in
 118 * an execution list, if subsequent requests have the same ID as the first then
 119 * the two requests must be combined. This is done simply by discarding requests
 120 * at the head of the queue until either only one requests is left (in which case
 121 * we use a NULL second context) or the first two requests have unique IDs.
 122 *
 123 * By always executing the first two requests in the queue the driver ensures
 124 * that the GPU is kept as busy as possible. In the case where a single context
 125 * completes but a second context is still executing, the request for this second
 126 * context will be at the head of the queue when we remove the first one. This
 127 * request will then be resubmitted along with a new request for a different context,
 128 * which will cause the hardware to continue executing the second request and queue
 129 * the new request (the GPU detects the condition of a context getting preempted
 130 * with the same context and optimizes the context switch flow by not doing
 131 * preemption, but just sampling the new tail pointer).
 132 *
 133 */
 134
 135#include <drm/drmP.h>
 136#include <drm/i915_drm.h>
 137#include "i915_drv.h"
 138#include "intel_mocs.h"
 139
 140#define GEN9_LR_CONTEXT_RENDER_SIZE (22 * PAGE_SIZE)
 141#define GEN8_LR_CONTEXT_RENDER_SIZE (20 * PAGE_SIZE)
 142#define GEN8_LR_CONTEXT_OTHER_SIZE (2 * PAGE_SIZE)
 143
 144#define RING_EXECLIST_QFULL		(1 << 0x2)
 145#define RING_EXECLIST1_VALID		(1 << 0x3)
 146#define RING_EXECLIST0_VALID		(1 << 0x4)
 147#define RING_EXECLIST_ACTIVE_STATUS	(3 << 0xE)
 148#define RING_EXECLIST1_ACTIVE		(1 << 0x11)
 149#define RING_EXECLIST0_ACTIVE		(1 << 0x12)
 150
 151#define GEN8_CTX_STATUS_IDLE_ACTIVE	(1 << 0)
 152#define GEN8_CTX_STATUS_PREEMPTED	(1 << 1)
 153#define GEN8_CTX_STATUS_ELEMENT_SWITCH	(1 << 2)
 154#define GEN8_CTX_STATUS_ACTIVE_IDLE	(1 << 3)
 155#define GEN8_CTX_STATUS_COMPLETE	(1 << 4)
 156#define GEN8_CTX_STATUS_LITE_RESTORE	(1 << 15)
 157
 158#define CTX_LRI_HEADER_0		0x01
 159#define CTX_CONTEXT_CONTROL		0x02
 160#define CTX_RING_HEAD			0x04
 161#define CTX_RING_TAIL			0x06
 162#define CTX_RING_BUFFER_START		0x08
 163#define CTX_RING_BUFFER_CONTROL		0x0a
 164#define CTX_BB_HEAD_U			0x0c
 165#define CTX_BB_HEAD_L			0x0e
 166#define CTX_BB_STATE			0x10
 167#define CTX_SECOND_BB_HEAD_U		0x12
 168#define CTX_SECOND_BB_HEAD_L		0x14
 169#define CTX_SECOND_BB_STATE		0x16
 170#define CTX_BB_PER_CTX_PTR		0x18
 171#define CTX_RCS_INDIRECT_CTX		0x1a
 172#define CTX_RCS_INDIRECT_CTX_OFFSET	0x1c
 173#define CTX_LRI_HEADER_1		0x21
 174#define CTX_CTX_TIMESTAMP		0x22
 175#define CTX_PDP3_UDW			0x24
 176#define CTX_PDP3_LDW			0x26
 177#define CTX_PDP2_UDW			0x28
 178#define CTX_PDP2_LDW			0x2a
 179#define CTX_PDP1_UDW			0x2c
 180#define CTX_PDP1_LDW			0x2e
 181#define CTX_PDP0_UDW			0x30
 182#define CTX_PDP0_LDW			0x32
 183#define CTX_LRI_HEADER_2		0x41
 184#define CTX_R_PWR_CLK_STATE		0x42
 185#define CTX_GPGPU_CSR_BASE_ADDRESS	0x44
 186
 187#define GEN8_CTX_VALID (1<<0)
 188#define GEN8_CTX_FORCE_PD_RESTORE (1<<1)
 189#define GEN8_CTX_FORCE_RESTORE (1<<2)
 190#define GEN8_CTX_L3LLC_COHERENT (1<<5)
 191#define GEN8_CTX_PRIVILEGE (1<<8)
 192
 193#define ASSIGN_CTX_REG(reg_state, pos, reg, val) do { \
 194	(reg_state)[(pos)+0] = i915_mmio_reg_offset(reg); \
 195	(reg_state)[(pos)+1] = (val); \
 196} while (0)
 197
 198#define ASSIGN_CTX_PDP(ppgtt, reg_state, n) do {		\
 199	const u64 _addr = i915_page_dir_dma_addr((ppgtt), (n));	\
 200	reg_state[CTX_PDP ## n ## _UDW+1] = upper_32_bits(_addr); \
 201	reg_state[CTX_PDP ## n ## _LDW+1] = lower_32_bits(_addr); \
 202} while (0)
 203
 204#define ASSIGN_CTX_PML4(ppgtt, reg_state) do { \
 205	reg_state[CTX_PDP0_UDW + 1] = upper_32_bits(px_dma(&ppgtt->pml4)); \
 206	reg_state[CTX_PDP0_LDW + 1] = lower_32_bits(px_dma(&ppgtt->pml4)); \
 207} while (0)
 208
 209enum {
 210	ADVANCED_CONTEXT = 0,
 211	LEGACY_32B_CONTEXT,
 212	ADVANCED_AD_CONTEXT,
 213	LEGACY_64B_CONTEXT
 214};
 215#define GEN8_CTX_ADDRESSING_MODE_SHIFT 3
 216#define GEN8_CTX_ADDRESSING_MODE(dev)  (USES_FULL_48BIT_PPGTT(dev) ?\
 217		LEGACY_64B_CONTEXT :\
 218		LEGACY_32B_CONTEXT)
 219enum {
 220	FAULT_AND_HANG = 0,
 221	FAULT_AND_HALT, /* Debug only */
 222	FAULT_AND_STREAM,
 223	FAULT_AND_CONTINUE /* Unsupported */
 224};
 225#define GEN8_CTX_ID_SHIFT 32
 226#define GEN8_CTX_RCS_INDIRECT_CTX_OFFSET_DEFAULT	0x17
 227#define GEN9_CTX_RCS_INDIRECT_CTX_OFFSET_DEFAULT	0x26
 228
 229static int intel_lr_context_pin(struct intel_context *ctx,
 230				struct intel_engine_cs *engine);
 231static void lrc_setup_hardware_status_page(struct intel_engine_cs *ring,
 232		struct drm_i915_gem_object *default_ctx_obj);
 233
 234
 235/**
 236 * intel_sanitize_enable_execlists() - sanitize i915.enable_execlists
 237 * @dev: DRM device.
 238 * @enable_execlists: value of i915.enable_execlists module parameter.
 239 *
 240 * Only certain platforms support Execlists (the prerequisites being
 241 * support for Logical Ring Contexts and Aliasing PPGTT or better).
 242 *
 243 * Return: 1 if Execlists is supported and has to be enabled.
 244 */
 245int intel_sanitize_enable_execlists(struct drm_device *dev, int enable_execlists)
 246{
 247	WARN_ON(i915.enable_ppgtt == -1);
 248
 249	/* On platforms with execlist available, vGPU will only
 250	 * support execlist mode, no ring buffer mode.
 251	 */
 252	if (HAS_LOGICAL_RING_CONTEXTS(dev) && intel_vgpu_active(dev))
 253		return 1;
 254
 255	if (INTEL_INFO(dev)->gen >= 9)
 256		return 1;
 257
 258	if (enable_execlists == 0)
 259		return 0;
 260
 261	if (HAS_LOGICAL_RING_CONTEXTS(dev) && USES_PPGTT(dev) &&
 262	    i915.use_mmio_flip >= 0)
 263		return 1;
 264
 265	return 0;
 266}
 267
 268static void
 269logical_ring_init_platform_invariants(struct intel_engine_cs *ring)
 270{
 271	struct drm_device *dev = ring->dev;
 272
 273	ring->disable_lite_restore_wa = (IS_SKL_REVID(dev, 0, SKL_REVID_B0) ||
 274					IS_BXT_REVID(dev, 0, BXT_REVID_A1)) &&
 275					(ring->id == VCS || ring->id == VCS2);
 276
 277	ring->ctx_desc_template = GEN8_CTX_VALID;
 278	ring->ctx_desc_template |= GEN8_CTX_ADDRESSING_MODE(dev) <<
 279				   GEN8_CTX_ADDRESSING_MODE_SHIFT;
 280	if (IS_GEN8(dev))
 281		ring->ctx_desc_template |= GEN8_CTX_L3LLC_COHERENT;
 282	ring->ctx_desc_template |= GEN8_CTX_PRIVILEGE;
 283
 284	/* TODO: WaDisableLiteRestore when we start using semaphore
 285	 * signalling between Command Streamers */
 286	/* ring->ctx_desc_template |= GEN8_CTX_FORCE_RESTORE; */
 287
 288	/* WaEnableForceRestoreInCtxtDescForVCS:skl */
 289	/* WaEnableForceRestoreInCtxtDescForVCS:bxt */
 290	if (ring->disable_lite_restore_wa)
 291		ring->ctx_desc_template |= GEN8_CTX_FORCE_RESTORE;
 292}
 293
 294/**
 295 * intel_lr_context_descriptor_update() - calculate & cache the descriptor
 296 * 					  descriptor for a pinned context
 297 *
 298 * @ctx: Context to work on
 299 * @ring: Engine the descriptor will be used with
 300 *
 301 * The context descriptor encodes various attributes of a context,
 302 * including its GTT address and some flags. Because it's fairly
 303 * expensive to calculate, we'll just do it once and cache the result,
 304 * which remains valid until the context is unpinned.
 305 *
 306 * This is what a descriptor looks like, from LSB to MSB:
 307 *    bits 0-11:    flags, GEN8_CTX_* (cached in ctx_desc_template)
 308 *    bits 12-31:    LRCA, GTT address of (the HWSP of) this context
 309 *    bits 32-51:    ctx ID, a globally unique tag (the LRCA again!)
 310 *    bits 52-63:    reserved, may encode the engine ID (for GuC)
 311 */
 312static void
 313intel_lr_context_descriptor_update(struct intel_context *ctx,
 314				   struct intel_engine_cs *ring)
 315{
 316	uint64_t lrca, desc;
 317
 318	lrca = ctx->engine[ring->id].lrc_vma->node.start +
 319	       LRC_PPHWSP_PN * PAGE_SIZE;
 320
 321	desc = ring->ctx_desc_template;			   /* bits  0-11 */
 322	desc |= lrca;					   /* bits 12-31 */
 323	desc |= (lrca >> PAGE_SHIFT) << GEN8_CTX_ID_SHIFT; /* bits 32-51 */
 324
 325	ctx->engine[ring->id].lrc_desc = desc;
 326}
 327
 328uint64_t intel_lr_context_descriptor(struct intel_context *ctx,
 329				     struct intel_engine_cs *ring)
 330{
 331	return ctx->engine[ring->id].lrc_desc;
 332}
 333
 334/**
 335 * intel_execlists_ctx_id() - get the Execlists Context ID
 336 * @ctx: Context to get the ID for
 337 * @ring: Engine to get the ID for
 338 *
 339 * Do not confuse with ctx->id! Unfortunately we have a name overload
 340 * here: the old context ID we pass to userspace as a handler so that
 341 * they can refer to a context, and the new context ID we pass to the
 342 * ELSP so that the GPU can inform us of the context status via
 343 * interrupts.
 344 *
 345 * The context ID is a portion of the context descriptor, so we can
 346 * just extract the required part from the cached descriptor.
 347 *
 348 * Return: 20-bits globally unique context ID.
 349 */
 350u32 intel_execlists_ctx_id(struct intel_context *ctx,
 351			   struct intel_engine_cs *ring)
 352{
 353	return intel_lr_context_descriptor(ctx, ring) >> GEN8_CTX_ID_SHIFT;
 354}
 355
 356static void execlists_elsp_write(struct drm_i915_gem_request *rq0,
 357				 struct drm_i915_gem_request *rq1)
 358{
 359
 360	struct intel_engine_cs *ring = rq0->ring;
 361	struct drm_device *dev = ring->dev;
 362	struct drm_i915_private *dev_priv = dev->dev_private;
 363	uint64_t desc[2];
 364
 365	if (rq1) {
 366		desc[1] = intel_lr_context_descriptor(rq1->ctx, rq1->ring);
 367		rq1->elsp_submitted++;
 368	} else {
 369		desc[1] = 0;
 370	}
 371
 372	desc[0] = intel_lr_context_descriptor(rq0->ctx, rq0->ring);
 373	rq0->elsp_submitted++;
 374
 375	/* You must always write both descriptors in the order below. */
 376	spin_lock(&dev_priv->uncore.lock);
 377	intel_uncore_forcewake_get__locked(dev_priv, FORCEWAKE_ALL);
 378	I915_WRITE_FW(RING_ELSP(ring), upper_32_bits(desc[1]));
 379	I915_WRITE_FW(RING_ELSP(ring), lower_32_bits(desc[1]));
 380
 381	I915_WRITE_FW(RING_ELSP(ring), upper_32_bits(desc[0]));
 382	/* The context is automatically loaded after the following */
 383	I915_WRITE_FW(RING_ELSP(ring), lower_32_bits(desc[0]));
 384
 385	/* ELSP is a wo register, use another nearby reg for posting */
 386	POSTING_READ_FW(RING_EXECLIST_STATUS_LO(ring));
 387	intel_uncore_forcewake_put__locked(dev_priv, FORCEWAKE_ALL);
 388	spin_unlock(&dev_priv->uncore.lock);
 389}
 390
 391static int execlists_update_context(struct drm_i915_gem_request *rq)
 392{
 393	struct intel_engine_cs *ring = rq->ring;
 394	struct i915_hw_ppgtt *ppgtt = rq->ctx->ppgtt;
 395	uint32_t *reg_state = rq->ctx->engine[ring->id].lrc_reg_state;
 396
 397	reg_state[CTX_RING_TAIL+1] = rq->tail;
 398
 399	if (ppgtt && !USES_FULL_48BIT_PPGTT(ppgtt->base.dev)) {
 400		/* True 32b PPGTT with dynamic page allocation: update PDP
 401		 * registers and point the unallocated PDPs to scratch page.
 402		 * PML4 is allocated during ppgtt init, so this is not needed
 403		 * in 48-bit mode.
 404		 */
 405		ASSIGN_CTX_PDP(ppgtt, reg_state, 3);
 406		ASSIGN_CTX_PDP(ppgtt, reg_state, 2);
 407		ASSIGN_CTX_PDP(ppgtt, reg_state, 1);
 408		ASSIGN_CTX_PDP(ppgtt, reg_state, 0);
 409	}
 410
 411	return 0;
 412}
 413
 414static void execlists_submit_requests(struct drm_i915_gem_request *rq0,
 415				      struct drm_i915_gem_request *rq1)
 416{
 417	execlists_update_context(rq0);
 418
 419	if (rq1)
 420		execlists_update_context(rq1);
 421
 422	execlists_elsp_write(rq0, rq1);
 423}
 424
 425static void execlists_context_unqueue(struct intel_engine_cs *ring)
 426{
 427	struct drm_i915_gem_request *req0 = NULL, *req1 = NULL;
 428	struct drm_i915_gem_request *cursor = NULL, *tmp = NULL;
 429
 430	assert_spin_locked(&ring->execlist_lock);
 431
 432	/*
 433	 * If irqs are not active generate a warning as batches that finish
 434	 * without the irqs may get lost and a GPU Hang may occur.
 435	 */
 436	WARN_ON(!intel_irqs_enabled(ring->dev->dev_private));
 437
 438	if (list_empty(&ring->execlist_queue))
 439		return;
 440
 441	/* Try to read in pairs */
 442	list_for_each_entry_safe(cursor, tmp, &ring->execlist_queue,
 443				 execlist_link) {
 444		if (!req0) {
 445			req0 = cursor;
 446		} else if (req0->ctx == cursor->ctx) {
 447			/* Same ctx: ignore first request, as second request
 448			 * will update tail past first request's workload */
 449			cursor->elsp_submitted = req0->elsp_submitted;
 450			list_move_tail(&req0->execlist_link,
 451				       &ring->execlist_retired_req_list);
 452			req0 = cursor;
 453		} else {
 454			req1 = cursor;
 455			break;
 456		}
 457	}
 458
 459	if (IS_GEN8(ring->dev) || IS_GEN9(ring->dev)) {
 460		/*
 461		 * WaIdleLiteRestore: make sure we never cause a lite
 462		 * restore with HEAD==TAIL
 463		 */
 464		if (req0->elsp_submitted) {
 465			/*
 466			 * Apply the wa NOOPS to prevent ring:HEAD == req:TAIL
 467			 * as we resubmit the request. See gen8_emit_request()
 468			 * for where we prepare the padding after the end of the
 469			 * request.
 470			 */
 471			struct intel_ringbuffer *ringbuf;
 472
 473			ringbuf = req0->ctx->engine[ring->id].ringbuf;
 474			req0->tail += 8;
 475			req0->tail &= ringbuf->size - 1;
 476		}
 477	}
 478
 479	WARN_ON(req1 && req1->elsp_submitted);
 480
 481	execlists_submit_requests(req0, req1);
 482}
 483
 484static bool execlists_check_remove_request(struct intel_engine_cs *ring,
 485					   u32 request_id)
 486{
 487	struct drm_i915_gem_request *head_req;
 488
 489	assert_spin_locked(&ring->execlist_lock);
 490
 491	head_req = list_first_entry_or_null(&ring->execlist_queue,
 492					    struct drm_i915_gem_request,
 493					    execlist_link);
 494
 495	if (head_req != NULL) {
 496		if (intel_execlists_ctx_id(head_req->ctx, ring) == request_id) {
 497			WARN(head_req->elsp_submitted == 0,
 498			     "Never submitted head request\n");
 499
 500			if (--head_req->elsp_submitted <= 0) {
 501				list_move_tail(&head_req->execlist_link,
 502					       &ring->execlist_retired_req_list);
 503				return true;
 504			}
 505		}
 506	}
 507
 508	return false;
 509}
 510
 511static void get_context_status(struct intel_engine_cs *ring,
 512			       u8 read_pointer,
 513			       u32 *status, u32 *context_id)
 514{
 515	struct drm_i915_private *dev_priv = ring->dev->dev_private;
 516
 517	if (WARN_ON(read_pointer >= GEN8_CSB_ENTRIES))
 518		return;
 519
 520	*status = I915_READ(RING_CONTEXT_STATUS_BUF_LO(ring, read_pointer));
 521	*context_id = I915_READ(RING_CONTEXT_STATUS_BUF_HI(ring, read_pointer));
 522}
 523
 524/**
 525 * intel_lrc_irq_handler() - handle Context Switch interrupts
 526 * @ring: Engine Command Streamer to handle.
 527 *
 528 * Check the unread Context Status Buffers and manage the submission of new
 529 * contexts to the ELSP accordingly.
 530 */
 531void intel_lrc_irq_handler(struct intel_engine_cs *ring)
 532{
 533	struct drm_i915_private *dev_priv = ring->dev->dev_private;
 534	u32 status_pointer;
 535	u8 read_pointer;
 536	u8 write_pointer;
 537	u32 status = 0;
 538	u32 status_id;
 539	u32 submit_contexts = 0;
 540
 541	status_pointer = I915_READ(RING_CONTEXT_STATUS_PTR(ring));
 542
 543	read_pointer = ring->next_context_status_buffer;
 544	write_pointer = GEN8_CSB_WRITE_PTR(status_pointer);
 545	if (read_pointer > write_pointer)
 546		write_pointer += GEN8_CSB_ENTRIES;
 547
 548	spin_lock(&ring->execlist_lock);
 549
 550	while (read_pointer < write_pointer) {
 551
 552		get_context_status(ring, ++read_pointer % GEN8_CSB_ENTRIES,
 553				   &status, &status_id);
 554
 555		if (status & GEN8_CTX_STATUS_IDLE_ACTIVE)
 556			continue;
 557
 558		if (status & GEN8_CTX_STATUS_PREEMPTED) {
 559			if (status & GEN8_CTX_STATUS_LITE_RESTORE) {
 560				if (execlists_check_remove_request(ring, status_id))
 561					WARN(1, "Lite Restored request removed from queue\n");
 562			} else
 563				WARN(1, "Preemption without Lite Restore\n");
 564		}
 565
 566		if ((status & GEN8_CTX_STATUS_ACTIVE_IDLE) ||
 567		    (status & GEN8_CTX_STATUS_ELEMENT_SWITCH)) {
 568			if (execlists_check_remove_request(ring, status_id))
 569				submit_contexts++;
 570		}
 571	}
 572
 573	if (ring->disable_lite_restore_wa) {
 574		/* Prevent a ctx to preempt itself */
 575		if ((status & GEN8_CTX_STATUS_ACTIVE_IDLE) &&
 576		    (submit_contexts != 0))
 577			execlists_context_unqueue(ring);
 578	} else if (submit_contexts != 0) {
 579		execlists_context_unqueue(ring);
 580	}
 581
 582	spin_unlock(&ring->execlist_lock);
 583
 584	if (unlikely(submit_contexts > 2))
 585		DRM_ERROR("More than two context complete events?\n");
 586
 587	ring->next_context_status_buffer = write_pointer % GEN8_CSB_ENTRIES;
 588
 589	/* Update the read pointer to the old write pointer. Manual ringbuffer
 590	 * management ftw </sarcasm> */
 591	I915_WRITE(RING_CONTEXT_STATUS_PTR(ring),
 592		   _MASKED_FIELD(GEN8_CSB_READ_PTR_MASK,
 593				 ring->next_context_status_buffer << 8));
 594}
 595
 596static int execlists_context_queue(struct drm_i915_gem_request *request)
 597{
 598	struct intel_engine_cs *ring = request->ring;
 599	struct drm_i915_gem_request *cursor;
 600	int num_elements = 0;
 601
 602	if (request->ctx != request->i915->kernel_context)
 603		intel_lr_context_pin(request->ctx, ring);
 604
 605	i915_gem_request_reference(request);
 606
 607	spin_lock_irq(&ring->execlist_lock);
 608
 609	list_for_each_entry(cursor, &ring->execlist_queue, execlist_link)
 610		if (++num_elements > 2)
 611			break;
 612
 613	if (num_elements > 2) {
 614		struct drm_i915_gem_request *tail_req;
 615
 616		tail_req = list_last_entry(&ring->execlist_queue,
 617					   struct drm_i915_gem_request,
 618					   execlist_link);
 619
 620		if (request->ctx == tail_req->ctx) {
 621			WARN(tail_req->elsp_submitted != 0,
 622				"More than 2 already-submitted reqs queued\n");
 623			list_move_tail(&tail_req->execlist_link,
 624				       &ring->execlist_retired_req_list);
 625		}
 626	}
 627
 628	list_add_tail(&request->execlist_link, &ring->execlist_queue);
 629	if (num_elements == 0)
 630		execlists_context_unqueue(ring);
 631
 632	spin_unlock_irq(&ring->execlist_lock);
 633
 634	return 0;
 635}
 636
 637static int logical_ring_invalidate_all_caches(struct drm_i915_gem_request *req)
 638{
 639	struct intel_engine_cs *ring = req->ring;
 640	uint32_t flush_domains;
 641	int ret;
 642
 643	flush_domains = 0;
 644	if (ring->gpu_caches_dirty)
 645		flush_domains = I915_GEM_GPU_DOMAINS;
 646
 647	ret = ring->emit_flush(req, I915_GEM_GPU_DOMAINS, flush_domains);
 648	if (ret)
 649		return ret;
 650
 651	ring->gpu_caches_dirty = false;
 652	return 0;
 653}
 654
 655static int execlists_move_to_gpu(struct drm_i915_gem_request *req,
 656				 struct list_head *vmas)
 657{
 658	const unsigned other_rings = ~intel_ring_flag(req->ring);
 659	struct i915_vma *vma;
 660	uint32_t flush_domains = 0;
 661	bool flush_chipset = false;
 662	int ret;
 663
 664	list_for_each_entry(vma, vmas, exec_list) {
 665		struct drm_i915_gem_object *obj = vma->obj;
 666
 667		if (obj->active & other_rings) {
 668			ret = i915_gem_object_sync(obj, req->ring, &req);
 669			if (ret)
 670				return ret;
 671		}
 672
 673		if (obj->base.write_domain & I915_GEM_DOMAIN_CPU)
 674			flush_chipset |= i915_gem_clflush_object(obj, false);
 675
 676		flush_domains |= obj->base.write_domain;
 677	}
 678
 679	if (flush_domains & I915_GEM_DOMAIN_GTT)
 680		wmb();
 681
 682	/* Unconditionally invalidate gpu caches and ensure that we do flush
 683	 * any residual writes from the previous batch.
 684	 */
 685	return logical_ring_invalidate_all_caches(req);
 686}
 687
 688int intel_logical_ring_alloc_request_extras(struct drm_i915_gem_request *request)
 689{
 690	int ret = 0;
 691
 692	request->ringbuf = request->ctx->engine[request->ring->id].ringbuf;
 693
 694	if (i915.enable_guc_submission) {
 695		/*
 696		 * Check that the GuC has space for the request before
 697		 * going any further, as the i915_add_request() call
 698		 * later on mustn't fail ...
 699		 */
 700		struct intel_guc *guc = &request->i915->guc;
 701
 702		ret = i915_guc_wq_check_space(guc->execbuf_client);
 703		if (ret)
 704			return ret;
 705	}
 706
 707	if (request->ctx != request->i915->kernel_context)
 708		ret = intel_lr_context_pin(request->ctx, request->ring);
 709
 710	return ret;
 711}
 712
 713static int logical_ring_wait_for_space(struct drm_i915_gem_request *req,
 714				       int bytes)
 715{
 716	struct intel_ringbuffer *ringbuf = req->ringbuf;
 717	struct intel_engine_cs *ring = req->ring;
 718	struct drm_i915_gem_request *target;
 719	unsigned space;
 720	int ret;
 721
 722	if (intel_ring_space(ringbuf) >= bytes)
 723		return 0;
 724
 725	/* The whole point of reserving space is to not wait! */
 726	WARN_ON(ringbuf->reserved_in_use);
 727
 728	list_for_each_entry(target, &ring->request_list, list) {
 729		/*
 730		 * The request queue is per-engine, so can contain requests
 731		 * from multiple ringbuffers. Here, we must ignore any that
 732		 * aren't from the ringbuffer we're considering.
 733		 */
 734		if (target->ringbuf != ringbuf)
 735			continue;
 736
 737		/* Would completion of this request free enough space? */
 738		space = __intel_ring_space(target->postfix, ringbuf->tail,
 739					   ringbuf->size);
 740		if (space >= bytes)
 741			break;
 742	}
 743
 744	if (WARN_ON(&target->list == &ring->request_list))
 745		return -ENOSPC;
 746
 747	ret = i915_wait_request(target);
 748	if (ret)
 749		return ret;
 750
 751	ringbuf->space = space;
 752	return 0;
 753}
 754
 755/*
 756 * intel_logical_ring_advance_and_submit() - advance the tail and submit the workload
 757 * @request: Request to advance the logical ringbuffer of.
 758 *
 759 * The tail is updated in our logical ringbuffer struct, not in the actual context. What
 760 * really happens during submission is that the context and current tail will be placed
 761 * on a queue waiting for the ELSP to be ready to accept a new context submission. At that
 762 * point, the tail *inside* the context is updated and the ELSP written to.
 763 */
 764static int
 765intel_logical_ring_advance_and_submit(struct drm_i915_gem_request *request)
 766{
 767	struct intel_ringbuffer *ringbuf = request->ringbuf;
 768	struct drm_i915_private *dev_priv = request->i915;
 769	struct intel_engine_cs *engine = request->ring;
 770
 771	intel_logical_ring_advance(ringbuf);
 772	request->tail = ringbuf->tail;
 773
 774	/*
 775	 * Here we add two extra NOOPs as padding to avoid
 776	 * lite restore of a context with HEAD==TAIL.
 777	 *
 778	 * Caller must reserve WA_TAIL_DWORDS for us!
 779	 */
 780	intel_logical_ring_emit(ringbuf, MI_NOOP);
 781	intel_logical_ring_emit(ringbuf, MI_NOOP);
 782	intel_logical_ring_advance(ringbuf);
 783
 784	if (intel_ring_stopped(engine))
 785		return 0;
 786
 787	if (engine->last_context != request->ctx) {
 788		if (engine->last_context)
 789			intel_lr_context_unpin(engine->last_context, engine);
 790		if (request->ctx != request->i915->kernel_context) {
 791			intel_lr_context_pin(request->ctx, engine);
 792			engine->last_context = request->ctx;
 793		} else {
 794			engine->last_context = NULL;
 795		}
 796	}
 797
 798	if (dev_priv->guc.execbuf_client)
 799		i915_guc_submit(dev_priv->guc.execbuf_client, request);
 800	else
 801		execlists_context_queue(request);
 802
 803	return 0;
 804}
 805
 806static void __wrap_ring_buffer(struct intel_ringbuffer *ringbuf)
 807{
 808	uint32_t __iomem *virt;
 809	int rem = ringbuf->size - ringbuf->tail;
 810
 811	virt = ringbuf->virtual_start + ringbuf->tail;
 812	rem /= 4;
 813	while (rem--)
 814		iowrite32(MI_NOOP, virt++);
 815
 816	ringbuf->tail = 0;
 817	intel_ring_update_space(ringbuf);
 818}
 819
 820static int logical_ring_prepare(struct drm_i915_gem_request *req, int bytes)
 821{
 822	struct intel_ringbuffer *ringbuf = req->ringbuf;
 823	int remain_usable = ringbuf->effective_size - ringbuf->tail;
 824	int remain_actual = ringbuf->size - ringbuf->tail;
 825	int ret, total_bytes, wait_bytes = 0;
 826	bool need_wrap = false;
 827
 828	if (ringbuf->reserved_in_use)
 829		total_bytes = bytes;
 830	else
 831		total_bytes = bytes + ringbuf->reserved_size;
 832
 833	if (unlikely(bytes > remain_usable)) {
 834		/*
 835		 * Not enough space for the basic request. So need to flush
 836		 * out the remainder and then wait for base + reserved.
 837		 */
 838		wait_bytes = remain_actual + total_bytes;
 839		need_wrap = true;
 840	} else {
 841		if (unlikely(total_bytes > remain_usable)) {
 842			/*
 843			 * The base request will fit but the reserved space
 844			 * falls off the end. So don't need an immediate wrap
 845			 * and only need to effectively wait for the reserved
 846			 * size space from the start of ringbuffer.
 847			 */
 848			wait_bytes = remain_actual + ringbuf->reserved_size;
 849		} else if (total_bytes > ringbuf->space) {
 850			/* No wrapping required, just waiting. */
 851			wait_bytes = total_bytes;
 852		}
 853	}
 854
 855	if (wait_bytes) {
 856		ret = logical_ring_wait_for_space(req, wait_bytes);
 857		if (unlikely(ret))
 858			return ret;
 859
 860		if (need_wrap)
 861			__wrap_ring_buffer(ringbuf);
 862	}
 863
 864	return 0;
 865}
 866
 867/**
 868 * intel_logical_ring_begin() - prepare the logical ringbuffer to accept some commands
 869 *
 870 * @req: The request to start some new work for
 871 * @num_dwords: number of DWORDs that we plan to write to the ringbuffer.
 872 *
 873 * The ringbuffer might not be ready to accept the commands right away (maybe it needs to
 874 * be wrapped, or wait a bit for the tail to be updated). This function takes care of that
 875 * and also preallocates a request (every workload submission is still mediated through
 876 * requests, same as it did with legacy ringbuffer submission).
 877 *
 878 * Return: non-zero if the ringbuffer is not ready to be written to.
 879 */
 880int intel_logical_ring_begin(struct drm_i915_gem_request *req, int num_dwords)
 881{
 882	struct drm_i915_private *dev_priv;
 883	int ret;
 884
 885	WARN_ON(req == NULL);
 886	dev_priv = req->ring->dev->dev_private;
 887
 888	ret = i915_gem_check_wedge(&dev_priv->gpu_error,
 889				   dev_priv->mm.interruptible);
 890	if (ret)
 891		return ret;
 892
 893	ret = logical_ring_prepare(req, num_dwords * sizeof(uint32_t));
 894	if (ret)
 895		return ret;
 896
 897	req->ringbuf->space -= num_dwords * sizeof(uint32_t);
 898	return 0;
 899}
 900
 901int intel_logical_ring_reserve_space(struct drm_i915_gem_request *request)
 902{
 903	/*
 904	 * The first call merely notes the reserve request and is common for
 905	 * all back ends. The subsequent localised _begin() call actually
 906	 * ensures that the reservation is available. Without the begin, if
 907	 * the request creator immediately submitted the request without
 908	 * adding any commands to it then there might not actually be
 909	 * sufficient room for the submission commands.
 910	 */
 911	intel_ring_reserved_space_reserve(request->ringbuf, MIN_SPACE_FOR_ADD_REQUEST);
 912
 913	return intel_logical_ring_begin(request, 0);
 914}
 915
 916/**
 917 * execlists_submission() - submit a batchbuffer for execution, Execlists style
 918 * @dev: DRM device.
 919 * @file: DRM file.
 920 * @ring: Engine Command Streamer to submit to.
 921 * @ctx: Context to employ for this submission.
 922 * @args: execbuffer call arguments.
 923 * @vmas: list of vmas.
 924 * @batch_obj: the batchbuffer to submit.
 925 * @exec_start: batchbuffer start virtual address pointer.
 926 * @dispatch_flags: translated execbuffer call flags.
 927 *
 928 * This is the evil twin version of i915_gem_ringbuffer_submission. It abstracts
 929 * away the submission details of the execbuffer ioctl call.
 930 *
 931 * Return: non-zero if the submission fails.
 932 */
 933int intel_execlists_submission(struct i915_execbuffer_params *params,
 934			       struct drm_i915_gem_execbuffer2 *args,
 935			       struct list_head *vmas)
 936{
 937	struct drm_device       *dev = params->dev;
 938	struct intel_engine_cs  *ring = params->ring;
 939	struct drm_i915_private *dev_priv = dev->dev_private;
 940	struct intel_ringbuffer *ringbuf = params->ctx->engine[ring->id].ringbuf;
 941	u64 exec_start;
 942	int instp_mode;
 943	u32 instp_mask;
 944	int ret;
 945
 946	instp_mode = args->flags & I915_EXEC_CONSTANTS_MASK;
 947	instp_mask = I915_EXEC_CONSTANTS_MASK;
 948	switch (instp_mode) {
 949	case I915_EXEC_CONSTANTS_REL_GENERAL:
 950	case I915_EXEC_CONSTANTS_ABSOLUTE:
 951	case I915_EXEC_CONSTANTS_REL_SURFACE:
 952		if (instp_mode != 0 && ring != &dev_priv->ring[RCS]) {
 953			DRM_DEBUG("non-0 rel constants mode on non-RCS\n");
 954			return -EINVAL;
 955		}
 956
 957		if (instp_mode != dev_priv->relative_constants_mode) {
 958			if (instp_mode == I915_EXEC_CONSTANTS_REL_SURFACE) {
 959				DRM_DEBUG("rel surface constants mode invalid on gen5+\n");
 960				return -EINVAL;
 961			}
 962
 963			/* The HW changed the meaning on this bit on gen6 */
 964			instp_mask &= ~I915_EXEC_CONSTANTS_REL_SURFACE;
 965		}
 966		break;
 967	default:
 968		DRM_DEBUG("execbuf with unknown constants: %d\n", instp_mode);
 969		return -EINVAL;
 970	}
 971
 972	if (args->flags & I915_EXEC_GEN7_SOL_RESET) {
 973		DRM_DEBUG("sol reset is gen7 only\n");
 974		return -EINVAL;
 975	}
 976
 977	ret = execlists_move_to_gpu(params->request, vmas);
 978	if (ret)
 979		return ret;
 980
 981	if (ring == &dev_priv->ring[RCS] &&
 982	    instp_mode != dev_priv->relative_constants_mode) {
 983		ret = intel_logical_ring_begin(params->request, 4);
 984		if (ret)
 985			return ret;
 986
 987		intel_logical_ring_emit(ringbuf, MI_NOOP);
 988		intel_logical_ring_emit(ringbuf, MI_LOAD_REGISTER_IMM(1));
 989		intel_logical_ring_emit_reg(ringbuf, INSTPM);
 990		intel_logical_ring_emit(ringbuf, instp_mask << 16 | instp_mode);
 991		intel_logical_ring_advance(ringbuf);
 992
 993		dev_priv->relative_constants_mode = instp_mode;
 994	}
 995
 996	exec_start = params->batch_obj_vm_offset +
 997		     args->batch_start_offset;
 998
 999	ret = ring->emit_bb_start(params->request, exec_start, params->dispatch_flags);
1000	if (ret)
1001		return ret;
1002
1003	trace_i915_gem_ring_dispatch(params->request, params->dispatch_flags);
1004
1005	i915_gem_execbuffer_move_to_active(vmas, params->request);
1006	i915_gem_execbuffer_retire_commands(params);
1007
1008	return 0;
1009}
1010
1011void intel_execlists_retire_requests(struct intel_engine_cs *ring)
1012{
1013	struct drm_i915_gem_request *req, *tmp;
1014	struct list_head retired_list;
1015
1016	WARN_ON(!mutex_is_locked(&ring->dev->struct_mutex));
1017	if (list_empty(&ring->execlist_retired_req_list))
1018		return;
1019
1020	INIT_LIST_HEAD(&retired_list);
1021	spin_lock_irq(&ring->execlist_lock);
1022	list_replace_init(&ring->execlist_retired_req_list, &retired_list);
1023	spin_unlock_irq(&ring->execlist_lock);
1024
1025	list_for_each_entry_safe(req, tmp, &retired_list, execlist_link) {
1026		struct intel_context *ctx = req->ctx;
1027		struct drm_i915_gem_object *ctx_obj =
1028				ctx->engine[ring->id].state;
1029
1030		if (ctx_obj && (ctx != req->i915->kernel_context))
1031			intel_lr_context_unpin(ctx, ring);
1032
1033		list_del(&req->execlist_link);
1034		i915_gem_request_unreference(req);
1035	}
1036}
1037
1038void intel_logical_ring_stop(struct intel_engine_cs *ring)
1039{
1040	struct drm_i915_private *dev_priv = ring->dev->dev_private;
1041	int ret;
1042
1043	if (!intel_ring_initialized(ring))
1044		return;
1045
1046	ret = intel_ring_idle(ring);
1047	if (ret && !i915_reset_in_progress(&to_i915(ring->dev)->gpu_error))
1048		DRM_ERROR("failed to quiesce %s whilst cleaning up: %d\n",
1049			  ring->name, ret);
1050
1051	/* TODO: Is this correct with Execlists enabled? */
1052	I915_WRITE_MODE(ring, _MASKED_BIT_ENABLE(STOP_RING));
1053	if (wait_for_atomic((I915_READ_MODE(ring) & MODE_IDLE) != 0, 1000)) {
1054		DRM_ERROR("%s :timed out trying to stop ring\n", ring->name);
1055		return;
1056	}
1057	I915_WRITE_MODE(ring, _MASKED_BIT_DISABLE(STOP_RING));
1058}
1059
1060int logical_ring_flush_all_caches(struct drm_i915_gem_request *req)
1061{
1062	struct intel_engine_cs *ring = req->ring;
1063	int ret;
1064
1065	if (!ring->gpu_caches_dirty)
1066		return 0;
1067
1068	ret = ring->emit_flush(req, 0, I915_GEM_GPU_DOMAINS);
1069	if (ret)
1070		return ret;
1071
1072	ring->gpu_caches_dirty = false;
1073	return 0;
1074}
1075
1076static int intel_lr_context_do_pin(struct intel_context *ctx,
1077				   struct intel_engine_cs *ring)
1078{
1079	struct drm_device *dev = ring->dev;
1080	struct drm_i915_private *dev_priv = dev->dev_private;
1081	struct drm_i915_gem_object *ctx_obj = ctx->engine[ring->id].state;
1082	struct intel_ringbuffer *ringbuf = ctx->engine[ring->id].ringbuf;
1083	struct page *lrc_state_page;
1084	uint32_t *lrc_reg_state;
1085	int ret;
1086
1087	WARN_ON(!mutex_is_locked(&ring->dev->struct_mutex));
1088
1089	ret = i915_gem_obj_ggtt_pin(ctx_obj, GEN8_LR_CONTEXT_ALIGN,
1090			PIN_OFFSET_BIAS | GUC_WOPCM_TOP);
1091	if (ret)
1092		return ret;
1093
1094	lrc_state_page = i915_gem_object_get_dirty_page(ctx_obj, LRC_STATE_PN);
1095	if (WARN_ON(!lrc_state_page)) {
1096		ret = -ENODEV;
1097		goto unpin_ctx_obj;
1098	}
1099
1100	ret = intel_pin_and_map_ringbuffer_obj(ring->dev, ringbuf);
1101	if (ret)
1102		goto unpin_ctx_obj;
1103
1104	ctx->engine[ring->id].lrc_vma = i915_gem_obj_to_ggtt(ctx_obj);
1105	intel_lr_context_descriptor_update(ctx, ring);
1106	lrc_reg_state = kmap(lrc_state_page);
1107	lrc_reg_state[CTX_RING_BUFFER_START+1] = ringbuf->vma->node.start;
1108	ctx->engine[ring->id].lrc_reg_state = lrc_reg_state;
1109	ctx_obj->dirty = true;
1110
1111	/* Invalidate GuC TLB. */
1112	if (i915.enable_guc_submission)
1113		I915_WRITE(GEN8_GTCR, GEN8_GTCR_INVALIDATE);
1114
1115	return ret;
1116
1117unpin_ctx_obj:
1118	i915_gem_object_ggtt_unpin(ctx_obj);
1119
1120	return ret;
1121}
1122
1123static int intel_lr_context_pin(struct intel_context *ctx,
1124				struct intel_engine_cs *engine)
1125{
1126	int ret = 0;
1127
1128	if (ctx->engine[engine->id].pin_count++ == 0) {
1129		ret = intel_lr_context_do_pin(ctx, engine);
1130		if (ret)
1131			goto reset_pin_count;
1132
1133		i915_gem_context_reference(ctx);
1134	}
1135	return ret;
1136
1137reset_pin_count:
1138	ctx->engine[engine->id].pin_count = 0;
1139	return ret;
1140}
1141
1142void intel_lr_context_unpin(struct intel_context *ctx,
1143			    struct intel_engine_cs *engine)
1144{
1145	struct drm_i915_gem_object *ctx_obj = ctx->engine[engine->id].state;
1146
1147	WARN_ON(!mutex_is_locked(&ctx->i915->dev->struct_mutex));
1148	if (--ctx->engine[engine->id].pin_count == 0) {
1149		kunmap(kmap_to_page(ctx->engine[engine->id].lrc_reg_state));
1150		intel_unpin_ringbuffer_obj(ctx->engine[engine->id].ringbuf);
1151		i915_gem_object_ggtt_unpin(ctx_obj);
1152		ctx->engine[engine->id].lrc_vma = NULL;
1153		ctx->engine[engine->id].lrc_desc = 0;
1154		ctx->engine[engine->id].lrc_reg_state = NULL;
1155
1156		i915_gem_context_unreference(ctx);
1157	}
1158}
1159
1160static int intel_logical_ring_workarounds_emit(struct drm_i915_gem_request *req)
1161{
1162	int ret, i;
1163	struct intel_engine_cs *ring = req->ring;
1164	struct intel_ringbuffer *ringbuf = req->ringbuf;
1165	struct drm_device *dev = ring->dev;
1166	struct drm_i915_private *dev_priv = dev->dev_private;
1167	struct i915_workarounds *w = &dev_priv->workarounds;
1168
1169	if (w->count == 0)
1170		return 0;
1171
1172	ring->gpu_caches_dirty = true;
1173	ret = logical_ring_flush_all_caches(req);
1174	if (ret)
1175		return ret;
1176
1177	ret = intel_logical_ring_begin(req, w->count * 2 + 2);
1178	if (ret)
1179		return ret;
1180
1181	intel_logical_ring_emit(ringbuf, MI_LOAD_REGISTER_IMM(w->count));
1182	for (i = 0; i < w->count; i++) {
1183		intel_logical_ring_emit_reg(ringbuf, w->reg[i].addr);
1184		intel_logical_ring_emit(ringbuf, w->reg[i].value);
1185	}
1186	intel_logical_ring_emit(ringbuf, MI_NOOP);
1187
1188	intel_logical_ring_advance(ringbuf);
1189
1190	ring->gpu_caches_dirty = true;
1191	ret = logical_ring_flush_all_caches(req);
1192	if (ret)
1193		return ret;
1194
1195	return 0;
1196}
1197
1198#define wa_ctx_emit(batch, index, cmd)					\
1199	do {								\
1200		int __index = (index)++;				\
1201		if (WARN_ON(__index >= (PAGE_SIZE / sizeof(uint32_t)))) { \
1202			return -ENOSPC;					\
1203		}							\
1204		batch[__index] = (cmd);					\
1205	} while (0)
1206
1207#define wa_ctx_emit_reg(batch, index, reg) \
1208	wa_ctx_emit((batch), (index), i915_mmio_reg_offset(reg))
1209
1210/*
1211 * In this WA we need to set GEN8_L3SQCREG4[21:21] and reset it after
1212 * PIPE_CONTROL instruction. This is required for the flush to happen correctly
1213 * but there is a slight complication as this is applied in WA batch where the
1214 * values are only initialized once so we cannot take register value at the
1215 * beginning and reuse it further; hence we save its value to memory, upload a
1216 * constant value with bit21 set and then we restore it back with the saved value.
1217 * To simplify the WA, a constant value is formed by using the default value
1218 * of this register. This shouldn't be a problem because we are only modifying
1219 * it for a short period and this batch in non-premptible. We can ofcourse
1220 * use additional instructions that read the actual value of the register
1221 * at that time and set our bit of interest but it makes the WA complicated.
1222 *
1223 * This WA is also required for Gen9 so extracting as a function avoids
1224 * code duplication.
1225 */
1226static inline int gen8_emit_flush_coherentl3_wa(struct intel_engine_cs *ring,
1227						uint32_t *const batch,
1228						uint32_t index)
1229{
1230	uint32_t l3sqc4_flush = (0x40400000 | GEN8_LQSC_FLUSH_COHERENT_LINES);
1231
1232	/*
1233	 * WaDisableLSQCROPERFforOCL:skl
1234	 * This WA is implemented in skl_init_clock_gating() but since
1235	 * this batch updates GEN8_L3SQCREG4 with default value we need to
1236	 * set this bit here to retain the WA during flush.
1237	 */
1238	if (IS_SKL_REVID(ring->dev, 0, SKL_REVID_E0))
1239		l3sqc4_flush |= GEN8_LQSC_RO_PERF_DIS;
1240
1241	wa_ctx_emit(batch, index, (MI_STORE_REGISTER_MEM_GEN8 |
1242				   MI_SRM_LRM_GLOBAL_GTT));
1243	wa_ctx_emit_reg(batch, index, GEN8_L3SQCREG4);
1244	wa_ctx_emit(batch, index, ring->scratch.gtt_offset + 256);
1245	wa_ctx_emit(batch, index, 0);
1246
1247	wa_ctx_emit(batch, index, MI_LOAD_REGISTER_IMM(1));
1248	wa_ctx_emit_reg(batch, index, GEN8_L3SQCREG4);
1249	wa_ctx_emit(batch, index, l3sqc4_flush);
1250
1251	wa_ctx_emit(batch, index, GFX_OP_PIPE_CONTROL(6));
1252	wa_ctx_emit(batch, index, (PIPE_CONTROL_CS_STALL |
1253				   PIPE_CONTROL_DC_FLUSH_ENABLE));
1254	wa_ctx_emit(batch, index, 0);
1255	wa_ctx_emit(batch, index, 0);
1256	wa_ctx_emit(batch, index, 0);
1257	wa_ctx_emit(batch, index, 0);
1258
1259	wa_ctx_emit(batch, index, (MI_LOAD_REGISTER_MEM_GEN8 |
1260				   MI_SRM_LRM_GLOBAL_GTT));
1261	wa_ctx_emit_reg(batch, index, GEN8_L3SQCREG4);
1262	wa_ctx_emit(batch, index, ring->scratch.gtt_offset + 256);
1263	wa_ctx_emit(batch, index, 0);
1264
1265	return index;
1266}
1267
1268static inline uint32_t wa_ctx_start(struct i915_wa_ctx_bb *wa_ctx,
1269				    uint32_t offset,
1270				    uint32_t start_alignment)
1271{
1272	return wa_ctx->offset = ALIGN(offset, start_alignment);
1273}
1274
1275static inline int wa_ctx_end(struct i915_wa_ctx_bb *wa_ctx,
1276			     uint32_t offset,
1277			     uint32_t size_alignment)
1278{
1279	wa_ctx->size = offset - wa_ctx->offset;
1280
1281	WARN(wa_ctx->size % size_alignment,
1282	     "wa_ctx_bb failed sanity checks: size %d is not aligned to %d\n",
1283	     wa_ctx->size, size_alignment);
1284	return 0;
1285}
1286
1287/**
1288 * gen8_init_indirectctx_bb() - initialize indirect ctx batch with WA
1289 *
1290 * @ring: only applicable for RCS
1291 * @wa_ctx: structure representing wa_ctx
1292 *  offset: specifies start of the batch, should be cache-aligned. This is updated
1293 *    with the offset value received as input.
1294 *  size: size of the batch in DWORDS but HW expects in terms of cachelines
1295 * @batch: page in which WA are loaded
1296 * @offset: This field specifies the start of the batch, it should be
1297 *  cache-aligned otherwise it is adjusted accordingly.
1298 *  Typically we only have one indirect_ctx and per_ctx batch buffer which are
1299 *  initialized at the beginning and shared across all contexts but this field
1300 *  helps us to have multiple batches at different offsets and select them based
1301 *  on a criteria. At the moment this batch always start at the beginning of the page
1302 *  and at this point we don't have multiple wa_ctx batch buffers.
1303 *
1304 *  The number of WA applied are not known at the beginning; we use this field
1305 *  to return the no of DWORDS written.
1306 *
1307 *  It is to be noted that this batch does not contain MI_BATCH_BUFFER_END
1308 *  so it adds NOOPs as padding to make it cacheline aligned.
1309 *  MI_BATCH_BUFFER_END will be added to perctx batch and both of them together
1310 *  makes a complete batch buffer.
1311 *
1312 * Return: non-zero if we exceed the PAGE_SIZE limit.
1313 */
1314
1315static int gen8_init_indirectctx_bb(struct intel_engine_cs *ring,
1316				    struct i915_wa_ctx_bb *wa_ctx,
1317				    uint32_t *const batch,
1318				    uint32_t *offset)
1319{
1320	uint32_t scratch_addr;
1321	uint32_t index = wa_ctx_start(wa_ctx, *offset, CACHELINE_DWORDS);
1322
1323	/* WaDisableCtxRestoreArbitration:bdw,chv */
1324	wa_ctx_emit(batch, index, MI_ARB_ON_OFF | MI_ARB_DISABLE);
1325
1326	/* WaFlushCoherentL3CacheLinesAtContextSwitch:bdw */
1327	if (IS_BROADWELL(ring->dev)) {
1328		int rc = gen8_emit_flush_coherentl3_wa(ring, batch, index);
1329		if (rc < 0)
1330			return rc;
1331		index = rc;
1332	}
1333
1334	/* WaClearSlmSpaceAtContextSwitch:bdw,chv */
1335	/* Actual scratch location is at 128 bytes offset */
1336	scratch_addr = ring->scratch.gtt_offset + 2*CACHELINE_BYTES;
1337
1338	wa_ctx_emit(batch, index, GFX_OP_PIPE_CONTROL(6));
1339	wa_ctx_emit(batch, index, (PIPE_CONTROL_FLUSH_L3 |
1340				   PIPE_CONTROL_GLOBAL_GTT_IVB |
1341				   PIPE_CONTROL_CS_STALL |
1342				   PIPE_CONTROL_QW_WRITE));
1343	wa_ctx_emit(batch, index, scratch_addr);
1344	wa_ctx_emit(batch, index, 0);
1345	wa_ctx_emit(batch, index, 0);
1346	wa_ctx_emit(batch, index, 0);
1347
1348	/* Pad to end of cacheline */
1349	while (index % CACHELINE_DWORDS)
1350		wa_ctx_emit(batch, index, MI_NOOP);
1351
1352	/*
1353	 * MI_BATCH_BUFFER_END is not required in Indirect ctx BB because
1354	 * execution depends on the length specified in terms of cache lines
1355	 * in the register CTX_RCS_INDIRECT_CTX
1356	 */
1357
1358	return wa_ctx_end(wa_ctx, *offset = index, CACHELINE_DWORDS);
1359}
1360
1361/**
1362 * gen8_init_perctx_bb() - initialize per ctx batch with WA
1363 *
1364 * @ring: only applicable for RCS
1365 * @wa_ctx: structure representing wa_ctx
1366 *  offset: specifies start of the batch, should be cache-aligned.
1367 *  size: size of the batch in DWORDS but HW expects in terms of cachelines
1368 * @batch: page in which WA are loaded
1369 * @offset: This field specifies the start of this batch.
1370 *   This batch is started immediately after indirect_ctx batch. Since we ensure
1371 *   that indirect_ctx ends on a cacheline this batch is aligned automatically.
1372 *
1373 *   The number of DWORDS written are returned using this field.
1374 *
1375 *  This batch is terminated with MI_BATCH_BUFFER_END and so we need not add padding
1376 *  to align it with cacheline as padding after MI_BATCH_BUFFER_END is redundant.
1377 */
1378static int gen8_init_perctx_bb(struct intel_engine_cs *ring,
1379			       struct i915_wa_ctx_bb *wa_ctx,
1380			       uint32_t *const batch,
1381			       uint32_t *offset)
1382{
1383	uint32_t index = wa_ctx_start(wa_ctx, *offset, CACHELINE_DWORDS);
1384
1385	/* WaDisableCtxRestoreArbitration:bdw,chv */
1386	wa_ctx_emit(batch, index, MI_ARB_ON_OFF | MI_ARB_ENABLE);
1387
1388	wa_ctx_emit(batch, index, MI_BATCH_BUFFER_END);
1389
1390	return wa_ctx_end(wa_ctx, *offset = index, 1);
1391}
1392
1393static int gen9_init_indirectctx_bb(struct intel_engine_cs *ring,
1394				    struct i915_wa_ctx_bb *wa_ctx,
1395				    uint32_t *const batch,
1396				    uint32_t *offset)
1397{
1398	int ret;
1399	struct drm_device *dev = ring->dev;
1400	uint32_t index = wa_ctx_start(wa_ctx, *offset, CACHELINE_DWORDS);
1401
1402	/* WaDisableCtxRestoreArbitration:skl,bxt */
1403	if (IS_SKL_REVID(dev, 0, SKL_REVID_D0) ||
1404	    IS_BXT_REVID(dev, 0, BXT_REVID_A1))
1405		wa_ctx_emit(batch, index, MI_ARB_ON_OFF | MI_ARB_DISABLE);
1406
1407	/* WaFlushCoherentL3CacheLinesAtContextSwitch:skl,bxt */
1408	ret = gen8_emit_flush_coherentl3_wa(ring, batch, index);
1409	if (ret < 0)
1410		return ret;
1411	index = ret;
1412
1413	/* Pad to end of cacheline */
1414	while (index % CACHELINE_DWORDS)
1415		wa_ctx_emit(batch, index, MI_NOOP);
1416
1417	return wa_ctx_end(wa_ctx, *offset = index, CACHELINE_DWORDS);
1418}
1419
1420static int gen9_init_perctx_bb(struct intel_engine_cs *ring,
1421			       struct i915_wa_ctx_bb *wa_ctx,
1422			       uint32_t *const batch,
1423			       uint32_t *offset)
1424{
1425	struct drm_device *dev = ring->dev;
1426	uint32_t index = wa_ctx_start(wa_ctx, *offset, CACHELINE_DWORDS);
1427
1428	/* WaSetDisablePixMaskCammingAndRhwoInCommonSliceChicken:skl,bxt */
1429	if (IS_SKL_REVID(dev, 0, SKL_REVID_B0) ||
1430	    IS_BXT_REVID(dev, 0, BXT_REVID_A1)) {
1431		wa_ctx_emit(batch, index, MI_LOAD_REGISTER_IMM(1));
1432		wa_ctx_emit_reg(batch, index, GEN9_SLICE_COMMON_ECO_CHICKEN0);
1433		wa_ctx_emit(batch, index,
1434			    _MASKED_BIT_ENABLE(DISABLE_PIXEL_MASK_CAMMING));
1435		wa_ctx_emit(batch, index, MI_NOOP);
1436	}
1437
1438	/* WaDisableCtxRestoreArbitration:skl,bxt */
1439	if (IS_SKL_REVID(dev, 0, SKL_REVID_D0) ||
1440	    IS_BXT_REVID(dev, 0, BXT_REVID_A1))
1441		wa_ctx_emit(batch, index, MI_ARB_ON_OFF | MI_ARB_ENABLE);
1442
1443	wa_ctx_emit(batch, index, MI_BATCH_BUFFER_END);
1444
1445	return wa_ctx_end(wa_ctx, *offset = index, 1);
1446}
1447
1448static int lrc_setup_wa_ctx_obj(struct intel_engine_cs *ring, u32 size)
1449{
1450	int ret;
1451
1452	ring->wa_ctx.obj = i915_gem_alloc_object(ring->dev, PAGE_ALIGN(size));
1453	if (!ring->wa_ctx.obj) {
1454		DRM_DEBUG_DRIVER("alloc LRC WA ctx backing obj failed.\n");
1455		return -ENOMEM;
1456	}
1457
1458	ret = i915_gem_obj_ggtt_pin(ring->wa_ctx.obj, PAGE_SIZE, 0);
1459	if (ret) {
1460		DRM_DEBUG_DRIVER("pin LRC WA ctx backing obj failed: %d\n",
1461				 ret);
1462		drm_gem_object_unreference(&ring->wa_ctx.obj->base);
1463		return ret;
1464	}
1465
1466	return 0;
1467}
1468
1469static void lrc_destroy_wa_ctx_obj(struct intel_engine_cs *ring)
1470{
1471	if (ring->wa_ctx.obj) {
1472		i915_gem_object_ggtt_unpin(ring->wa_ctx.obj);
1473		drm_gem_object_unreference(&ring->wa_ctx.obj->base);
1474		ring->wa_ctx.obj = NULL;
1475	}
1476}
1477
1478static int intel_init_workaround_bb(struct intel_engine_cs *ring)
1479{
1480	int ret;
1481	uint32_t *batch;
1482	uint32_t offset;
1483	struct page *page;
1484	struct i915_ctx_workarounds *wa_ctx = &ring->wa_ctx;
1485
1486	WARN_ON(ring->id != RCS);
1487
1488	/* update this when WA for higher Gen are added */
1489	if (INTEL_INFO(ring->dev)->gen > 9) {
1490		DRM_ERROR("WA batch buffer is not initialized for Gen%d\n",
1491			  INTEL_INFO(ring->dev)->gen);
1492		return 0;
1493	}
1494
1495	/* some WA perform writes to scratch page, ensure it is valid */
1496	if (ring->scratch.obj == NULL) {
1497		DRM_ERROR("scratch page not allocated for %s\n", ring->name);
1498		return -EINVAL;
1499	}
1500
1501	ret = lrc_setup_wa_ctx_obj(ring, PAGE_SIZE);
1502	if (ret) {
1503		DRM_DEBUG_DRIVER("Failed to setup context WA page: %d\n", ret);
1504		return ret;
1505	}
1506
1507	page = i915_gem_object_get_dirty_page(wa_ctx->obj, 0);
1508	batch = kmap_atomic(page);
1509	offset = 0;
1510
1511	if (INTEL_INFO(ring->dev)->gen == 8) {
1512		ret = gen8_init_indirectctx_bb(ring,
1513					       &wa_ctx->indirect_ctx,
1514					       batch,
1515					       &offset);
1516		if (ret)
1517			goto out;
1518
1519		ret = gen8_init_perctx_bb(ring,
1520					  &wa_ctx->per_ctx,
1521					  batch,
1522					  &offset);
1523		if (ret)
1524			goto out;
1525	} else if (INTEL_INFO(ring->dev)->gen == 9) {
1526		ret = gen9_init_indirectctx_bb(ring,
1527					       &wa_ctx->indirect_ctx,
1528					       batch,
1529					       &offset);
1530		if (ret)
1531			goto out;
1532
1533		ret = gen9_init_perctx_bb(ring,
1534					  &wa_ctx->per_ctx,
1535					  batch,
1536					  &offset);
1537		if (ret)
1538			goto out;
1539	}
1540
1541out:
1542	kunmap_atomic(batch);
1543	if (ret)
1544		lrc_destroy_wa_ctx_obj(ring);
1545
1546	return ret;
1547}
1548
1549static int gen8_init_common_ring(struct intel_engine_cs *ring)
1550{
1551	struct drm_device *dev = ring->dev;
1552	struct drm_i915_private *dev_priv = dev->dev_private;
1553	u8 next_context_status_buffer_hw;
1554
1555	lrc_setup_hardware_status_page(ring,
1556				dev_priv->kernel_context->engine[ring->id].state);
1557
1558	I915_WRITE_IMR(ring, ~(ring->irq_enable_mask | ring->irq_keep_mask));
1559	I915_WRITE(RING_HWSTAM(ring->mmio_base), 0xffffffff);
1560
1561	I915_WRITE(RING_MODE_GEN7(ring),
1562		   _MASKED_BIT_DISABLE(GFX_REPLAY_MODE) |
1563		   _MASKED_BIT_ENABLE(GFX_RUN_LIST_ENABLE));
1564	POSTING_READ(RING_MODE_GEN7(ring));
1565
1566	/*
1567	 * Instead of resetting the Context Status Buffer (CSB) read pointer to
1568	 * zero, we need to read the write pointer from hardware and use its
1569	 * value because "this register is power context save restored".
1570	 * Effectively, these states have been observed:
1571	 *
1572	 *      | Suspend-to-idle (freeze) | Suspend-to-RAM (mem) |
1573	 * BDW  | CSB regs not reset       | CSB regs reset       |
1574	 * CHT  | CSB regs not reset       | CSB regs not reset   |
1575	 * SKL  |         ?                |         ?            |
1576	 * BXT  |         ?                |         ?            |
1577	 */
1578	next_context_status_buffer_hw =
1579		GEN8_CSB_WRITE_PTR(I915_READ(RING_CONTEXT_STATUS_PTR(ring)));
1580
1581	/*
1582	 * When the CSB registers are reset (also after power-up / gpu reset),
1583	 * CSB write pointer is set to all 1's, which is not valid, use '5' in
1584	 * this special case, so the first element read is CSB[0].
1585	 */
1586	if (next_context_status_buffer_hw == GEN8_CSB_PTR_MASK)
1587		next_context_status_buffer_hw = (GEN8_CSB_ENTRIES - 1);
1588
1589	ring->next_context_status_buffer = next_context_status_buffer_hw;
1590	DRM_DEBUG_DRIVER("Execlists enabled for %s\n", ring->name);
1591
1592	memset(&ring->hangcheck, 0, sizeof(ring->hangcheck));
1593
1594	return 0;
1595}
1596
1597static int gen8_init_render_ring(struct intel_engine_cs *ring)
1598{
1599	struct drm_device *dev = ring->dev;
1600	struct drm_i915_private *dev_priv = dev->dev_private;
1601	int ret;
1602
1603	ret = gen8_init_common_ring(ring);
1604	if (ret)
1605		return ret;
1606
1607	/* We need to disable the AsyncFlip performance optimisations in order
1608	 * to use MI_WAIT_FOR_EVENT within the CS. It should already be
1609	 * programmed to '1' on all products.
1610	 *
1611	 * WaDisableAsyncFlipPerfMode:snb,ivb,hsw,vlv,bdw,chv
1612	 */
1613	I915_WRITE(MI_MODE, _MASKED_BIT_ENABLE(ASYNC_FLIP_PERF_DISABLE));
1614
1615	I915_WRITE(INSTPM, _MASKED_BIT_ENABLE(INSTPM_FORCE_ORDERING));
1616
1617	return init_workarounds_ring(ring);
1618}
1619
1620static int gen9_init_render_ring(struct intel_engine_cs *ring)
1621{
1622	int ret;
1623
1624	ret = gen8_init_common_ring(ring);
1625	if (ret)
1626		return ret;
1627
1628	return init_workarounds_ring(ring);
1629}
1630
1631static int intel_logical_ring_emit_pdps(struct drm_i915_gem_request *req)
1632{
1633	struct i915_hw_ppgtt *ppgtt = req->ctx->ppgtt;
1634	struct intel_engine_cs *ring = req->ring;
1635	struct intel_ringbuffer *ringbuf = req->ringbuf;
1636	const int num_lri_cmds = GEN8_LEGACY_PDPES * 2;
1637	int i, ret;
1638
1639	ret = intel_logical_ring_begin(req, num_lri_cmds * 2 + 2);
1640	if (ret)
1641		return ret;
1642
1643	intel_logical_ring_emit(ringbuf, MI_LOAD_REGISTER_IMM(num_lri_cmds));
1644	for (i = GEN8_LEGACY_PDPES - 1; i >= 0; i--) {
1645		const dma_addr_t pd_daddr = i915_page_dir_dma_addr(ppgtt, i);
1646
1647		intel_logical_ring_emit_reg(ringbuf, GEN8_RING_PDP_UDW(ring, i));
1648		intel_logical_ring_emit(ringbuf, upper_32_bits(pd_daddr));
1649		intel_logical_ring_emit_reg(ringbuf, GEN8_RING_PDP_LDW(ring, i));
1650		intel_logical_ring_emit(ringbuf, lower_32_bits(pd_daddr));
1651	}
1652
1653	intel_logical_ring_emit(ringbuf, MI_NOOP);
1654	intel_logical_ring_advance(ringbuf);
1655
1656	return 0;
1657}
1658
1659static int gen8_emit_bb_start(struct drm_i915_gem_request *req,
1660			      u64 offset, unsigned dispatch_flags)
1661{
1662	struct intel_ringbuffer *ringbuf = req->ringbuf;
1663	bool ppgtt = !(dispatch_flags & I915_DISPATCH_SECURE);
1664	int ret;
1665
1666	/* Don't rely in hw updating PDPs, specially in lite-restore.
1667	 * Ideally, we should set Force PD Restore in ctx descriptor,
1668	 * but we can't. Force Restore would be a second option, but
1669	 * it is unsafe in case of lite-restore (because the ctx is
1670	 * not idle). PML4 is allocated during ppgtt init so this is
1671	 * not needed in 48-bit.*/
1672	if (req->ctx->ppgtt &&
1673	    (intel_ring_flag(req->ring) & req->ctx->ppgtt->pd_dirty_rings)) {
1674		if (!USES_FULL_48BIT_PPGTT(req->i915) &&
1675		    !intel_vgpu_active(req->i915->dev)) {
1676			ret = intel_logical_ring_emit_pdps(req);
1677			if (ret)
1678				return ret;
1679		}
1680
1681		req->ctx->ppgtt->pd_dirty_rings &= ~intel_ring_flag(req->ring);
1682	}
1683
1684	ret = intel_logical_ring_begin(req, 4);
1685	if (ret)
1686		return ret;
1687
1688	/* FIXME(BDW): Address space and security selectors. */
1689	intel_logical_ring_emit(ringbuf, MI_BATCH_BUFFER_START_GEN8 |
1690				(ppgtt<<8) |
1691				(dispatch_flags & I915_DISPATCH_RS ?
1692				 MI_BATCH_RESOURCE_STREAMER : 0));
1693	intel_logical_ring_emit(ringbuf, lower_32_bits(offset));
1694	intel_logical_ring_emit(ringbuf, upper_32_bits(offset));
1695	intel_logical_ring_emit(ringbuf, MI_NOOP);
1696	intel_logical_ring_advance(ringbuf);
1697
1698	return 0;
1699}
1700
1701static bool gen8_logical_ring_get_irq(struct intel_engine_cs *ring)
1702{
1703	struct drm_device *dev = ring->dev;
1704	struct drm_i915_private *dev_priv = dev->dev_private;
1705	unsigned long flags;
1706
1707	if (WARN_ON(!intel_irqs_enabled(dev_priv)))
1708		return false;
1709
1710	spin_lock_irqsave(&dev_priv->irq_lock, flags);
1711	if (ring->irq_refcount++ == 0) {
1712		I915_WRITE_IMR(ring, ~(ring->irq_enable_mask | ring->irq_keep_mask));
1713		POSTING_READ(RING_IMR(ring->mmio_base));
1714	}
1715	spin_unlock_irqrestore(&dev_priv->irq_lock, flags);
1716
1717	return true;
1718}
1719
1720static void gen8_logical_ring_put_irq(struct intel_engine_cs *ring)
1721{
1722	struct drm_device *dev = ring->dev;
1723	struct drm_i915_private *dev_priv = dev->dev_private;
1724	unsigned long flags;
1725
1726	spin_lock_irqsave(&dev_priv->irq_lock, flags);
1727	if (--ring->irq_refcount == 0) {
1728		I915_WRITE_IMR(ring, ~ring->irq_keep_mask);
1729		POSTING_READ(RING_IMR(ring->mmio_base));
1730	}
1731	spin_unlock_irqrestore(&dev_priv->irq_lock, flags);
1732}
1733
1734static int gen8_emit_flush(struct drm_i915_gem_request *request,
1735			   u32 invalidate_domains,
1736			   u32 unused)
1737{
1738	struct intel_ringbuffer *ringbuf = request->ringbuf;
1739	struct intel_engine_cs *ring = ringbuf->ring;
1740	struct drm_device *dev = ring->dev;
1741	struct drm_i915_private *dev_priv = dev->dev_private;
1742	uint32_t cmd;
1743	int ret;
1744
1745	ret = intel_logical_ring_begin(request, 4);
1746	if (ret)
1747		return ret;
1748
1749	cmd = MI_FLUSH_DW + 1;
1750
1751	/* We always require a command barrier so that subsequent
1752	 * commands, such as breadcrumb interrupts, are strictly ordered
1753	 * wrt the contents of the write cache being flushed to memory
1754	 * (and thus being coherent from the CPU).
1755	 */
1756	cmd |= MI_FLUSH_DW_STORE_INDEX | MI_FLUSH_DW_OP_STOREDW;
1757
1758	if (invalidate_domains & I915_GEM_GPU_DOMAINS) {
1759		cmd |= MI_INVALIDATE_TLB;
1760		if (ring == &dev_priv->ring[VCS])
1761			cmd |= MI_INVALIDATE_BSD;
1762	}
1763
1764	intel_logical_ring_emit(ringbuf, cmd);
1765	intel_logical_ring_emit(ringbuf,
1766				I915_GEM_HWS_SCRATCH_ADDR |
1767				MI_FLUSH_DW_USE_GTT);
1768	intel_logical_ring_emit(ringbuf, 0); /* upper addr */
1769	intel_logical_ring_emit(ringbuf, 0); /* value */
1770	intel_logical_ring_advance(ringbuf);
1771
1772	return 0;
1773}
1774
1775static int gen8_emit_flush_render(struct drm_i915_gem_request *request,
1776				  u32 invalidate_domains,
1777				  u32 flush_domains)
1778{
1779	struct intel_ringbuffer *ringbuf = request->ringbuf;
1780	struct intel_engine_cs *ring = ringbuf->ring;
1781	u32 scratch_addr = ring->scratch.gtt_offset + 2 * CACHELINE_BYTES;
1782	bool vf_flush_wa = false;
1783	u32 flags = 0;
1784	int ret;
1785
1786	flags |= PIPE_CONTROL_CS_STALL;
1787
1788	if (flush_domains) {
1789		flags |= PIPE_CONTROL_RENDER_TARGET_CACHE_FLUSH;
1790		flags |= PIPE_CONTROL_DEPTH_CACHE_FLUSH;
1791		flags |= PIPE_CONTROL_DC_FLUSH_ENABLE;
1792		flags |= PIPE_CONTROL_FLUSH_ENABLE;
1793	}
1794
1795	if (invalidate_domains) {
1796		flags |= PIPE_CONTROL_TLB_INVALIDATE;
1797		flags |= PIPE_CONTROL_INSTRUCTION_CACHE_INVALIDATE;
1798		flags |= PIPE_CONTROL_TEXTURE_CACHE_INVALIDATE;
1799		flags |= PIPE_CONTROL_VF_CACHE_INVALIDATE;
1800		flags |= PIPE_CONTROL_CONST_CACHE_INVALIDATE;
1801		flags |= PIPE_CONTROL_STATE_CACHE_INVALIDATE;
1802		flags |= PIPE_CONTROL_QW_WRITE;
1803		flags |= PIPE_CONTROL_GLOBAL_GTT_IVB;
1804
1805		/*
1806		 * On GEN9: before VF_CACHE_INVALIDATE we need to emit a NULL
1807		 * pipe control.
1808		 */
1809		if (IS_GEN9(ring->dev))
1810			vf_flush_wa = true;
1811	}
1812
1813	ret = intel_logical_ring_begin(request, vf_flush_wa ? 12 : 6);
1814	if (ret)
1815		return ret;
1816
1817	if (vf_flush_wa) {
1818		intel_logical_ring_emit(ringbuf, GFX_OP_PIPE_CONTROL(6));
1819		intel_logical_ring_emit(ringbuf, 0);
1820		intel_logical_ring_emit(ringbuf, 0);
1821		intel_logical_ring_emit(ringbuf, 0);
1822		intel_logical_ring_emit(ringbuf, 0);
1823		intel_logical_ring_emit(ringbuf, 0);
1824	}
1825
1826	intel_logical_ring_emit(ringbuf, GFX_OP_PIPE_CONTROL(6));
1827	intel_logical_ring_emit(ringbuf, flags);
1828	intel_logical_ring_emit(ringbuf, scratch_addr);
1829	intel_logical_ring_emit(ringbuf, 0);
1830	intel_logical_ring_emit(ringbuf, 0);
1831	intel_logical_ring_emit(ringbuf, 0);
1832	intel_logical_ring_advance(ringbuf);
1833
1834	return 0;
1835}
1836
1837static u32 gen8_get_seqno(struct intel_engine_cs *ring, bool lazy_coherency)
1838{
1839	return intel_read_status_page(ring, I915_GEM_HWS_INDEX);
1840}
1841
1842static void gen8_set_seqno(struct intel_engine_cs *ring, u32 seqno)
1843{
1844	intel_write_status_page(ring, I915_GEM_HWS_INDEX, seqno);
1845}
1846
1847static u32 bxt_a_get_seqno(struct intel_engine_cs *ring, bool lazy_coherency)
1848{
1849
1850	/*
1851	 * On BXT A steppings there is a HW coherency issue whereby the
1852	 * MI_STORE_DATA_IMM storing the completed request's seqno
1853	 * occasionally doesn't invalidate the CPU cache. Work around this by
1854	 * clflushing the corresponding cacheline whenever the caller wants
1855	 * the coherency to be guaranteed. Note that this cacheline is known
1856	 * to be clean at this point, since we only write it in
1857	 * bxt_a_set_seqno(), where we also do a clflush after the write. So
1858	 * this clflush in practice becomes an invalidate operation.
1859	 */
1860
1861	if (!lazy_coherency)
1862		intel_flush_status_page(ring, I915_GEM_HWS_INDEX);
1863
1864	return intel_read_status_page(ring, I915_GEM_HWS_INDEX);
1865}
1866
1867static void bxt_a_set_seqno(struct intel_engine_cs *ring, u32 seqno)
1868{
1869	intel_write_status_page(ring, I915_GEM_HWS_INDEX, seqno);
1870
1871	/* See bxt_a_get_seqno() explaining the reason for the clflush. */
1872	intel_flush_status_page(ring, I915_GEM_HWS_INDEX);
1873}
1874
1875/*
1876 * Reserve space for 2 NOOPs at the end of each request to be
1877 * used as a workaround for not being allowed to do lite
1878 * restore with HEAD==TAIL (WaIdleLiteRestore).
1879 */
1880#define WA_TAIL_DWORDS 2
1881
1882static inline u32 hws_seqno_address(struct intel_engine_cs *engine)
1883{
1884	return engine->status_page.gfx_addr + I915_GEM_HWS_INDEX_ADDR;
1885}
1886
1887static int gen8_emit_request(struct drm_i915_gem_request *request)
1888{
1889	struct intel_ringbuffer *ringbuf = request->ringbuf;
1890	int ret;
1891
1892	ret = intel_logical_ring_begin(request, 6 + WA_TAIL_DWORDS);
1893	if (ret)
1894		return ret;
1895
1896	/* w/a: bit 5 needs to be zero for MI_FLUSH_DW address. */
1897	BUILD_BUG_ON(I915_GEM_HWS_INDEX_ADDR & (1 << 5));
1898
1899	intel_logical_ring_emit(ringbuf,
1900				(MI_FLUSH_DW + 1) | MI_FLUSH_DW_OP_STOREDW);
1901	intel_logical_ring_emit(ringbuf,
1902				hws_seqno_address(request->ring) |
1903				MI_FLUSH_DW_USE_GTT);
1904	intel_logical_ring_emit(ringbuf, 0);
1905	intel_logical_ring_emit(ringbuf, i915_gem_request_get_seqno(request));
1906	intel_logical_ring_emit(ringbuf, MI_USER_INTERRUPT);
1907	intel_logical_ring_emit(ringbuf, MI_NOOP);
1908	return intel_logical_ring_advance_and_submit(request);
1909}
1910
1911static int gen8_emit_request_render(struct drm_i915_gem_request *request)
1912{
1913	struct intel_ringbuffer *ringbuf = request->ringbuf;
1914	int ret;
1915
1916	ret = intel_logical_ring_begin(request, 8 + WA_TAIL_DWORDS);
1917	if (ret)
1918		return ret;
1919
1920	/* We're using qword write, seqno should be aligned to 8 bytes. */
1921	BUILD_BUG_ON(I915_GEM_HWS_INDEX & 1);
1922
1923	/* w/a for post sync ops following a GPGPU operation we
1924	 * need a prior CS_STALL, which is emitted by the flush
1925	 * following the batch.
1926	 */
1927	intel_logical_ring_emit(ringbuf, GFX_OP_PIPE_CONTROL(6));
1928	intel_logical_ring_emit(ringbuf,
1929				(PIPE_CONTROL_GLOBAL_GTT_IVB |
1930				 PIPE_CONTROL_CS_STALL |
1931				 PIPE_CONTROL_QW_WRITE));
1932	intel_logical_ring_emit(ringbuf, hws_seqno_address(request->ring));
1933	intel_logical_ring_emit(ringbuf, 0);
1934	intel_logical_ring_emit(ringbuf, i915_gem_request_get_seqno(request));
1935	/* We're thrashing one dword of HWS. */
1936	intel_logical_ring_emit(ringbuf, 0);
1937	intel_logical_ring_emit(ringbuf, MI_USER_INTERRUPT);
1938	intel_logical_ring_emit(ringbuf, MI_NOOP);
1939	return intel_logical_ring_advance_and_submit(request);
1940}
1941
1942static int intel_lr_context_render_state_init(struct drm_i915_gem_request *req)
1943{
1944	struct render_state so;
1945	int ret;
1946
1947	ret = i915_gem_render_state_prepare(req->ring, &so);
1948	if (ret)
1949		return ret;
1950
1951	if (so.rodata == NULL)
1952		return 0;
1953
1954	ret = req->ring->emit_bb_start(req, so.ggtt_offset,
1955				       I915_DISPATCH_SECURE);
1956	if (ret)
1957		goto out;
1958
1959	ret = req->ring->emit_bb_start(req,
1960				       (so.ggtt_offset + so.aux_batch_offset),
1961				       I915_DISPATCH_SECURE);
1962	if (ret)
1963		goto out;
1964
1965	i915_vma_move_to_active(i915_gem_obj_to_ggtt(so.obj), req);
1966
1967out:
1968	i915_gem_render_state_fini(&so);
1969	return ret;
1970}
1971
1972static int gen8_init_rcs_context(struct drm_i915_gem_request *req)
1973{
1974	int ret;
1975
1976	ret = intel_logical_ring_workarounds_emit(req);
1977	if (ret)
1978		return ret;
1979
1980	ret = intel_rcs_context_init_mocs(req);
1981	/*
1982	 * Failing to program the MOCS is non-fatal.The system will not
1983	 * run at peak performance. So generate an error and carry on.
1984	 */
1985	if (ret)
1986		DRM_ERROR("MOCS failed to program: expect performance issues.\n");
1987
1988	return intel_lr_context_render_state_init(req);
1989}
1990
1991/**
1992 * intel_logical_ring_cleanup() - deallocate the Engine Command Streamer
1993 *
1994 * @ring: Engine Command Streamer.
1995 *
1996 */
1997void intel_logical_ring_cleanup(struct intel_engine_cs *ring)
1998{
1999	struct drm_i915_private *dev_priv;
2000
2001	if (!intel_ring_initialized(ring))
2002		return;
2003
2004	dev_priv = ring->dev->dev_private;
2005
2006	if (ring->buffer) {
2007		intel_logical_ring_stop(ring);
2008		WARN_ON((I915_READ_MODE(ring) & MODE_IDLE) == 0);
2009	}
2010
2011	if (ring->cleanup)
2012		ring->cleanup(ring);
2013
2014	i915_cmd_parser_fini_ring(ring);
2015	i915_gem_batch_pool_fini(&ring->batch_pool);
2016
2017	if (ring->status_page.obj) {
2018		kunmap(sg_page(ring->status_page.obj->pages->sgl));
2019		ring->status_page.obj = NULL;
2020	}
2021
2022	ring->disable_lite_restore_wa = false;
2023	ring->ctx_desc_template = 0;
2024
2025	lrc_destroy_wa_ctx_obj(ring);
2026	ring->dev = NULL;
2027}
2028
2029static void
2030logical_ring_default_vfuncs(struct drm_device *dev,
2031			    struct intel_engine_cs *ring)
2032{
2033	/* Default vfuncs which can be overriden by each engine. */
2034	ring->init_hw = gen8_init_common_ring;
2035	ring->emit_request = gen8_emit_request;
2036	ring->emit_flush = gen8_emit_flush;
2037	ring->irq_get = gen8_logical_ring_get_irq;
2038	ring->irq_put = gen8_logical_ring_put_irq;
2039	ring->emit_bb_start = gen8_emit_bb_start;
2040	if (IS_BXT_REVID(dev, 0, BXT_REVID_A1)) {
2041		ring->get_seqno = bxt_a_get_seqno;
2042		ring->set_seqno = bxt_a_set_seqno;
2043	} else {
2044		ring->get_seqno = gen8_get_seqno;
2045		ring->set_seqno = gen8_set_seqno;
2046	}
2047}
2048
2049static inline void
2050logical_ring_default_irqs(struct intel_engine_cs *ring, unsigned shift)
2051{
2052	ring->irq_enable_mask = GT_RENDER_USER_INTERRUPT << shift;
2053	ring->irq_keep_mask = GT_CONTEXT_SWITCH_INTERRUPT << shift;
2054}
2055
2056static int
2057logical_ring_init(struct drm_device *dev, struct intel_engine_cs *ring)
2058{
2059	struct intel_context *dctx = to_i915(dev)->kernel_context;
2060	int ret;
2061
2062	/* Intentionally left blank. */
2063	ring->buffer = NULL;
2064
2065	ring->dev = dev;
2066	INIT_LIST_HEAD(&ring->active_list);
2067	INIT_LIST_HEAD(&ring->request_list);
2068	i915_gem_batch_pool_init(dev, &ring->batch_pool);
2069	init_waitqueue_head(&ring->irq_queue);
2070
2071	INIT_LIST_HEAD(&ring->buffers);
2072	INIT_LIST_HEAD(&ring->execlist_queue);
2073	INIT_LIST_HEAD(&ring->execlist_retired_req_list);
2074	spin_lock_init(&ring->execlist_lock);
2075
2076	logical_ring_init_platform_invariants(ring);
2077
2078	ret = i915_cmd_parser_init_ring(ring);
2079	if (ret)
2080		goto error;
2081
2082	ret = intel_lr_context_deferred_alloc(dctx, ring);
2083	if (ret)
2084		goto error;
2085
2086	/* As this is the default context, always pin it */
2087	ret = intel_lr_context_do_pin(dctx, ring);
2088	if (ret) {
2089		DRM_ERROR(
2090			"Failed to pin and map ringbuffer %s: %d\n",
2091			ring->name, ret);
2092		goto error;
2093	}
2094
2095	return 0;
2096
2097error:
2098	intel_logical_ring_cleanup(ring);
2099	return ret;
2100}
2101
2102static int logical_render_ring_init(struct drm_device *dev)
2103{
2104	struct drm_i915_private *dev_priv = dev->dev_private;
2105	struct intel_engine_cs *ring = &dev_priv->ring[RCS];
2106	int ret;
2107
2108	ring->name = "render ring";
2109	ring->id = RCS;
2110	ring->exec_id = I915_EXEC_RENDER;
2111	ring->guc_id = GUC_RENDER_ENGINE;
2112	ring->mmio_base = RENDER_RING_BASE;
2113
2114	logical_ring_default_irqs(ring, GEN8_RCS_IRQ_SHIFT);
2115	if (HAS_L3_DPF(dev))
2116		ring->irq_keep_mask |= GT_RENDER_L3_PARITY_ERROR_INTERRUPT;
2117
2118	logical_ring_default_vfuncs(dev, ring);
2119
2120	/* Override some for render ring. */
2121	if (INTEL_INFO(dev)->gen >= 9)
2122		ring->init_hw = gen9_init_render_ring;
2123	else
2124		ring->init_hw = gen8_init_render_ring;
2125	ring->init_context = gen8_init_rcs_context;
2126	ring->cleanup = intel_fini_pipe_control;
2127	ring->emit_flush = gen8_emit_flush_render;
2128	ring->emit_request = gen8_emit_request_render;
2129
2130	ring->dev = dev;
2131
2132	ret = intel_init_pipe_control(ring);
2133	if (ret)
2134		return ret;
2135
2136	ret = intel_init_workaround_bb(ring);
2137	if (ret) {
2138		/*
2139		 * We continue even if we fail to initialize WA batch
2140		 * because we only expect rare glitches but nothing
2141		 * critical to prevent us from using GPU
2142		 */
2143		DRM_ERROR("WA batch buffer initialization failed: %d\n",
2144			  ret);
2145	}
2146
2147	ret = logical_ring_init(dev, ring);
2148	if (ret) {
2149		lrc_destroy_wa_ctx_obj(ring);
2150	}
2151
2152	return ret;
2153}
2154
2155static int logical_bsd_ring_init(struct drm_device *dev)
2156{
2157	struct drm_i915_private *dev_priv = dev->dev_private;
2158	struct intel_engine_cs *ring = &dev_priv->ring[VCS];
2159
2160	ring->name = "bsd ring";
2161	ring->id = VCS;
2162	ring->exec_id = I915_EXEC_BSD;
2163	ring->guc_id = GUC_VIDEO_ENGINE;
2164	ring->mmio_base = GEN6_BSD_RING_BASE;
2165
2166	logical_ring_default_irqs(ring, GEN8_VCS1_IRQ_SHIFT);
2167	logical_ring_default_vfuncs(dev, ring);
2168
2169	return logical_ring_init(dev, ring);
2170}
2171
2172static int logical_bsd2_ring_init(struct drm_device *dev)
2173{
2174	struct drm_i915_private *dev_priv = dev->dev_private;
2175	struct intel_engine_cs *ring = &dev_priv->ring[VCS2];
2176
2177	ring->name = "bsd2 ring";
2178	ring->id = VCS2;
2179	ring->exec_id = I915_EXEC_BSD;
2180	ring->guc_id = GUC_VIDEO_ENGINE2;
2181	ring->mmio_base = GEN8_BSD2_RING_BASE;
2182
2183	logical_ring_default_irqs(ring, GEN8_VCS2_IRQ_SHIFT);
2184	logical_ring_default_vfuncs(dev, ring);
2185
2186	return logical_ring_init(dev, ring);
2187}
2188
2189static int logical_blt_ring_init(struct drm_device *dev)
2190{
2191	struct drm_i915_private *dev_priv = dev->dev_private;
2192	struct intel_engine_cs *ring = &dev_priv->ring[BCS];
2193
2194	ring->name = "blitter ring";
2195	ring->id = BCS;
2196	ring->exec_id = I915_EXEC_BLT;
2197	ring->guc_id = GUC_BLITTER_ENGINE;
2198	ring->mmio_base = BLT_RING_BASE;
2199
2200	logical_ring_default_irqs(ring, GEN8_BCS_IRQ_SHIFT);
2201	logical_ring_default_vfuncs(dev, ring);
2202
2203	return logical_ring_init(dev, ring);
2204}
2205
2206static int logical_vebox_ring_init(struct drm_device *dev)
2207{
2208	struct drm_i915_private *dev_priv = dev->dev_private;
2209	struct intel_engine_cs *ring = &dev_priv->ring[VECS];
2210
2211	ring->name = "video enhancement ring";
2212	ring->id = VECS;
2213	ring->exec_id = I915_EXEC_VEBOX;
2214	ring->guc_id = GUC_VIDEOENHANCE_ENGINE;
2215	ring->mmio_base = VEBOX_RING_BASE;
2216
2217	logical_ring_default_irqs(ring, GEN8_VECS_IRQ_SHIFT);
2218	logical_ring_default_vfuncs(dev, ring);
2219
2220	return logical_ring_init(dev, ring);
2221}
2222
2223/**
2224 * intel_logical_rings_init() - allocate, populate and init the Engine Command Streamers
2225 * @dev: DRM device.
2226 *
2227 * This function inits the engines for an Execlists submission style (the equivalent in the
2228 * legacy ringbuffer submission world would be i915_gem_init_rings). It does it only for
2229 * those engines that are present in the hardware.
2230 *
2231 * Return: non-zero if the initialization failed.
2232 */
2233int intel_logical_rings_init(struct drm_device *dev)
2234{
2235	struct drm_i915_private *dev_priv = dev->dev_private;
2236	int ret;
2237
2238	ret = logical_render_ring_init(dev);
2239	if (ret)
2240		return ret;
2241
2242	if (HAS_BSD(dev)) {
2243		ret = logical_bsd_ring_init(dev);
2244		if (ret)
2245			goto cleanup_render_ring;
2246	}
2247
2248	if (HAS_BLT(dev)) {
2249		ret = logical_blt_ring_init(dev);
2250		if (ret)
2251			goto cleanup_bsd_ring;
2252	}
2253
2254	if (HAS_VEBOX(dev)) {
2255		ret = logical_vebox_ring_init(dev);
2256		if (ret)
2257			goto cleanup_blt_ring;
2258	}
2259
2260	if (HAS_BSD2(dev)) {
2261		ret = logical_bsd2_ring_init(dev);
2262		if (ret)
2263			goto cleanup_vebox_ring;
2264	}
2265
2266	return 0;
2267
2268cleanup_vebox_ring:
2269	intel_logical_ring_cleanup(&dev_priv->ring[VECS]);
2270cleanup_blt_ring:
2271	intel_logical_ring_cleanup(&dev_priv->ring[BCS]);
2272cleanup_bsd_ring:
2273	intel_logical_ring_cleanup(&dev_priv->ring[VCS]);
2274cleanup_render_ring:
2275	intel_logical_ring_cleanup(&dev_priv->ring[RCS]);
2276
2277	return ret;
2278}
2279
2280static u32
2281make_rpcs(struct drm_device *dev)
2282{
2283	u32 rpcs = 0;
2284
2285	/*
2286	 * No explicit RPCS request is needed to ensure full
2287	 * slice/subslice/EU enablement prior to Gen9.
2288	*/
2289	if (INTEL_INFO(dev)->gen < 9)
2290		return 0;
2291
2292	/*
2293	 * Starting in Gen9, render power gating can leave
2294	 * slice/subslice/EU in a partially enabled state. We
2295	 * must make an explicit request through RPCS for full
2296	 * enablement.
2297	*/
2298	if (INTEL_INFO(dev)->has_slice_pg) {
2299		rpcs |= GEN8_RPCS_S_CNT_ENABLE;
2300		rpcs |= INTEL_INFO(dev)->slice_total <<
2301			GEN8_RPCS_S_CNT_SHIFT;
2302		rpcs |= GEN8_RPCS_ENABLE;
2303	}
2304
2305	if (INTEL_INFO(dev)->has_subslice_pg) {
2306		rpcs |= GEN8_RPCS_SS_CNT_ENABLE;
2307		rpcs |= INTEL_INFO(dev)->subslice_per_slice <<
2308			GEN8_RPCS_SS_CNT_SHIFT;
2309		rpcs |= GEN8_RPCS_ENABLE;
2310	}
2311
2312	if (INTEL_INFO(dev)->has_eu_pg) {
2313		rpcs |= INTEL_INFO(dev)->eu_per_subslice <<
2314			GEN8_RPCS_EU_MIN_SHIFT;
2315		rpcs |= INTEL_INFO(dev)->eu_per_subslice <<
2316			GEN8_RPCS_EU_MAX_SHIFT;
2317		rpcs |= GEN8_RPCS_ENABLE;
2318	}
2319
2320	return rpcs;
2321}
2322
2323static u32 intel_lr_indirect_ctx_offset(struct intel_engine_cs *ring)
2324{
2325	u32 indirect_ctx_offset;
2326
2327	switch (INTEL_INFO(ring->dev)->gen) {
2328	default:
2329		MISSING_CASE(INTEL_INFO(ring->dev)->gen);
2330		/* fall through */
2331	case 9:
2332		indirect_ctx_offset =
2333			GEN9_CTX_RCS_INDIRECT_CTX_OFFSET_DEFAULT;
2334		break;
2335	case 8:
2336		indirect_ctx_offset =
2337			GEN8_CTX_RCS_INDIRECT_CTX_OFFSET_DEFAULT;
2338		break;
2339	}
2340
2341	return indirect_ctx_offset;
2342}
2343
2344static int
2345populate_lr_context(struct intel_context *ctx, struct drm_i915_gem_object *ctx_obj,
2346		    struct intel_engine_cs *ring, struct intel_ringbuffer *ringbuf)
2347{
2348	struct drm_device *dev = ring->dev;
2349	struct drm_i915_private *dev_priv = dev->dev_private;
2350	struct i915_hw_ppgtt *ppgtt = ctx->ppgtt;
2351	struct page *page;
2352	uint32_t *reg_state;
2353	int ret;
2354
2355	if (!ppgtt)
2356		ppgtt = dev_priv->mm.aliasing_ppgtt;
2357
2358	ret = i915_gem_object_set_to_cpu_domain(ctx_obj, true);
2359	if (ret) {
2360		DRM_DEBUG_DRIVER("Could not set to CPU domain\n");
2361		return ret;
2362	}
2363
2364	ret = i915_gem_object_get_pages(ctx_obj);
2365	if (ret) {
2366		DRM_DEBUG_DRIVER("Could not get object pages\n");
2367		return ret;
2368	}
2369
2370	i915_gem_object_pin_pages(ctx_obj);
2371
2372	/* The second page of the context object contains some fields which must
2373	 * be set up prior to the first execution. */
2374	page = i915_gem_object_get_dirty_page(ctx_obj, LRC_STATE_PN);
2375	reg_state = kmap_atomic(page);
2376
2377	/* A context is actually a big batch buffer with several MI_LOAD_REGISTER_IMM
2378	 * commands followed by (reg, value) pairs. The values we are setting here are
2379	 * only for the first context restore: on a subsequent save, the GPU will
2380	 * recreate this batchbuffer with new values (including all the missing
2381	 * MI_LOAD_REGISTER_IMM commands that we are not initializing here). */
2382	reg_state[CTX_LRI_HEADER_0] =
2383		MI_LOAD_REGISTER_IMM(ring->id == RCS ? 14 : 11) | MI_LRI_FORCE_POSTED;
2384	ASSIGN_CTX_REG(reg_state, CTX_CONTEXT_CONTROL, RING_CONTEXT_CONTROL(ring),
2385		       _MASKED_BIT_ENABLE(CTX_CTRL_INHIBIT_SYN_CTX_SWITCH |
2386					  CTX_CTRL_ENGINE_CTX_RESTORE_INHIBIT |
2387					  (HAS_RESOURCE_STREAMER(dev) ?
2388					    CTX_CTRL_RS_CTX_ENABLE : 0)));
2389	ASSIGN_CTX_REG(reg_state, CTX_RING_HEAD, RING_HEAD(ring->mmio_base), 0);
2390	ASSIGN_CTX_REG(reg_state, CTX_RING_TAIL, RING_TAIL(ring->mmio_base), 0);
2391	/* Ring buffer start address is not known until the buffer is pinned.
2392	 * It is written to the context image in execlists_update_context()
2393	 */
2394	ASSIGN_CTX_REG(reg_state, CTX_RING_BUFFER_START, RING_START(ring->mmio_base), 0);
2395	ASSIGN_CTX_REG(reg_state, CTX_RING_BUFFER_CONTROL, RING_CTL(ring->mmio_base),
2396		       ((ringbuf->size - PAGE_SIZE) & RING_NR_PAGES) | RING_VALID);
2397	ASSIGN_CTX_REG(reg_state, CTX_BB_HEAD_U, RING_BBADDR_UDW(ring->mmio_base), 0);
2398	ASSIGN_CTX_REG(reg_state, CTX_BB_HEAD_L, RING_BBADDR(ring->mmio_base), 0);
2399	ASSIGN_CTX_REG(reg_state, CTX_BB_STATE, RING_BBSTATE(ring->mmio_base),
2400		       RING_BB_PPGTT);
2401	ASSIGN_CTX_REG(reg_state, CTX_SECOND_BB_HEAD_U, RING_SBBADDR_UDW(ring->mmio_base), 0);
2402	ASSIGN_CTX_REG(reg_state, CTX_SECOND_BB_HEAD_L, RING_SBBADDR(ring->mmio_base), 0);
2403	ASSIGN_CTX_REG(reg_state, CTX_SECOND_BB_STATE, RING_SBBSTATE(ring->mmio_base), 0);
2404	if (ring->id == RCS) {
2405		ASSIGN_CTX_REG(reg_state, CTX_BB_PER_CTX_PTR, RING_BB_PER_CTX_PTR(ring->mmio_base), 0);
2406		ASSIGN_CTX_REG(reg_state, CTX_RCS_INDIRECT_CTX, RING_INDIRECT_CTX(ring->mmio_base), 0);
2407		ASSIGN_CTX_REG(reg_state, CTX_RCS_INDIRECT_CTX_OFFSET, RING_INDIRECT_CTX_OFFSET(ring->mmio_base), 0);
2408		if (ring->wa_ctx.obj) {
2409			struct i915_ctx_workarounds *wa_ctx = &ring->wa_ctx;
2410			uint32_t ggtt_offset = i915_gem_obj_ggtt_offset(wa_ctx->obj);
2411
2412			reg_state[CTX_RCS_INDIRECT_CTX+1] =
2413				(ggtt_offset + wa_ctx->indirect_ctx.offset * sizeof(uint32_t)) |
2414				(wa_ctx->indirect_ctx.size / CACHELINE_DWORDS);
2415
2416			reg_state[CTX_RCS_INDIRECT_CTX_OFFSET+1] =
2417				intel_lr_indirect_ctx_offset(ring) << 6;
2418
2419			reg_state[CTX_BB_PER_CTX_PTR+1] =
2420				(ggtt_offset + wa_ctx->per_ctx.offset * sizeof(uint32_t)) |
2421				0x01;
2422		}
2423	}
2424	reg_state[CTX_LRI_HEADER_1] = MI_LOAD_REGISTER_IMM(9) | MI_LRI_FORCE_POSTED;
2425	ASSIGN_CTX_REG(reg_state, CTX_CTX_TIMESTAMP, RING_CTX_TIMESTAMP(ring->mmio_base), 0);
2426	/* PDP values well be assigned later if needed */
2427	ASSIGN_CTX_REG(reg_state, CTX_PDP3_UDW, GEN8_RING_PDP_UDW(ring, 3), 0);
2428	ASSIGN_CTX_REG(reg_state, CTX_PDP3_LDW, GEN8_RING_PDP_LDW(ring, 3), 0);
2429	ASSIGN_CTX_REG(reg_state, CTX_PDP2_UDW, GEN8_RING_PDP_UDW(ring, 2), 0);
2430	ASSIGN_CTX_REG(reg_state, CTX_PDP2_LDW, GEN8_RING_PDP_LDW(ring, 2), 0);
2431	ASSIGN_CTX_REG(reg_state, CTX_PDP1_UDW, GEN8_RING_PDP_UDW(ring, 1), 0);
2432	ASSIGN_CTX_REG(reg_state, CTX_PDP1_LDW, GEN8_RING_PDP_LDW(ring, 1), 0);
2433	ASSIGN_CTX_REG(reg_state, CTX_PDP0_UDW, GEN8_RING_PDP_UDW(ring, 0), 0);
2434	ASSIGN_CTX_REG(reg_state, CTX_PDP0_LDW, GEN8_RING_PDP_LDW(ring, 0), 0);
2435
2436	if (USES_FULL_48BIT_PPGTT(ppgtt->base.dev)) {
2437		/* 64b PPGTT (48bit canonical)
2438		 * PDP0_DESCRIPTOR contains the base address to PML4 and
2439		 * other PDP Descriptors are ignored.
2440		 */
2441		ASSIGN_CTX_PML4(ppgtt, reg_state);
2442	} else {
2443		/* 32b PPGTT
2444		 * PDP*_DESCRIPTOR contains the base address of space supported.
2445		 * With dynamic page allocation, PDPs may not be allocated at
2446		 * this point. Point the unallocated PDPs to the scratch page
2447		 */
2448		ASSIGN_CTX_PDP(ppgtt, reg_state, 3);
2449		ASSIGN_CTX_PDP(ppgtt, reg_state, 2);
2450		ASSIGN_CTX_PDP(ppgtt, reg_state, 1);
2451		ASSIGN_CTX_PDP(ppgtt, reg_state, 0);
2452	}
2453
2454	if (ring->id == RCS) {
2455		reg_state[CTX_LRI_HEADER_2] = MI_LOAD_REGISTER_IMM(1);
2456		ASSIGN_CTX_REG(reg_state, CTX_R_PWR_CLK_STATE, GEN8_R_PWR_CLK_STATE,
2457			       make_rpcs(dev));
2458	}
2459
2460	kunmap_atomic(reg_state);
2461	i915_gem_object_unpin_pages(ctx_obj);
2462
2463	return 0;
2464}
2465
2466/**
2467 * intel_lr_context_free() - free the LRC specific bits of a context
2468 * @ctx: the LR context to free.
2469 *
2470 * The real context freeing is done in i915_gem_context_free: this only
2471 * takes care of the bits that are LRC related: the per-engine backing
2472 * objects and the logical ringbuffer.
2473 */
2474void intel_lr_context_free(struct intel_context *ctx)
2475{
2476	int i;
2477
2478	for (i = I915_NUM_RINGS; --i >= 0; ) {
2479		struct intel_ringbuffer *ringbuf = ctx->engine[i].ringbuf;
2480		struct drm_i915_gem_object *ctx_obj = ctx->engine[i].state;
2481
2482		if (!ctx_obj)
2483			continue;
2484
2485		if (ctx == ctx->i915->kernel_context) {
2486			intel_unpin_ringbuffer_obj(ringbuf);
2487			i915_gem_object_ggtt_unpin(ctx_obj);
2488		}
2489
2490		WARN_ON(ctx->engine[i].pin_count);
2491		intel_ringbuffer_free(ringbuf);
2492		drm_gem_object_unreference(&ctx_obj->base);
2493	}
2494}
2495
2496/**
2497 * intel_lr_context_size() - return the size of the context for an engine
2498 * @ring: which engine to find the context size for
2499 *
2500 * Each engine may require a different amount of space for a context image,
2501 * so when allocating (or copying) an image, this function can be used to
2502 * find the right size for the specific engine.
2503 *
2504 * Return: size (in bytes) of an engine-specific context image
2505 *
2506 * Note: this size includes the HWSP, which is part of the context image
2507 * in LRC mode, but does not include the "shared data page" used with
2508 * GuC submission. The caller should account for this if using the GuC.
2509 */
2510uint32_t intel_lr_context_size(struct intel_engine_cs *ring)
2511{
2512	int ret = 0;
2513
2514	WARN_ON(INTEL_INFO(ring->dev)->gen < 8);
2515
2516	switch (ring->id) {
2517	case RCS:
2518		if (INTEL_INFO(ring->dev)->gen >= 9)
2519			ret = GEN9_LR_CONTEXT_RENDER_SIZE;
2520		else
2521			ret = GEN8_LR_CONTEXT_RENDER_SIZE;
2522		break;
2523	case VCS:
2524	case BCS:
2525	case VECS:
2526	case VCS2:
2527		ret = GEN8_LR_CONTEXT_OTHER_SIZE;
2528		break;
2529	}
2530
2531	return ret;
2532}
2533
2534static void lrc_setup_hardware_status_page(struct intel_engine_cs *ring,
2535		struct drm_i915_gem_object *default_ctx_obj)
2536{
2537	struct drm_i915_private *dev_priv = ring->dev->dev_private;
2538	struct page *page;
2539
2540	/* The HWSP is part of the default context object in LRC mode. */
2541	ring->status_page.gfx_addr = i915_gem_obj_ggtt_offset(default_ctx_obj)
2542			+ LRC_PPHWSP_PN * PAGE_SIZE;
2543	page = i915_gem_object_get_page(default_ctx_obj, LRC_PPHWSP_PN);
2544	ring->status_page.page_addr = kmap(page);
2545	ring->status_page.obj = default_ctx_obj;
2546
2547	I915_WRITE(RING_HWS_PGA(ring->mmio_base),
2548			(u32)ring->status_page.gfx_addr);
2549	POSTING_READ(RING_HWS_PGA(ring->mmio_base));
2550}
2551
2552/**
2553 * intel_lr_context_deferred_alloc() - create the LRC specific bits of a context
2554 * @ctx: LR context to create.
2555 * @ring: engine to be used with the context.
2556 *
2557 * This function can be called more than once, with different engines, if we plan
2558 * to use the context with them. The context backing objects and the ringbuffers
2559 * (specially the ringbuffer backing objects) suck a lot of memory up, and that's why
2560 * the creation is a deferred call: it's better to make sure first that we need to use
2561 * a given ring with the context.
2562 *
2563 * Return: non-zero on error.
2564 */
2565
2566int intel_lr_context_deferred_alloc(struct intel_context *ctx,
2567				    struct intel_engine_cs *ring)
2568{
2569	struct drm_device *dev = ring->dev;
2570	struct drm_i915_gem_object *ctx_obj;
2571	uint32_t context_size;
2572	struct intel_ringbuffer *ringbuf;
2573	int ret;
2574
2575	WARN_ON(ctx->legacy_hw_ctx.rcs_state != NULL);
2576	WARN_ON(ctx->engine[ring->id].state);
2577
2578	context_size = round_up(intel_lr_context_size(ring), 4096);
2579
2580	/* One extra page as the sharing data between driver and GuC */
2581	context_size += PAGE_SIZE * LRC_PPHWSP_PN;
2582
2583	ctx_obj = i915_gem_alloc_object(dev, context_size);
2584	if (!ctx_obj) {
2585		DRM_DEBUG_DRIVER("Alloc LRC backing obj failed.\n");
2586		return -ENOMEM;
2587	}
2588
2589	ringbuf = intel_engine_create_ringbuffer(ring, 4 * PAGE_SIZE);
2590	if (IS_ERR(ringbuf)) {
2591		ret = PTR_ERR(ringbuf);
2592		goto error_deref_obj;
2593	}
2594
2595	ret = populate_lr_context(ctx, ctx_obj, ring, ringbuf);
2596	if (ret) {
2597		DRM_DEBUG_DRIVER("Failed to populate LRC: %d\n", ret);
2598		goto error_ringbuf;
2599	}
2600
2601	ctx->engine[ring->id].ringbuf = ringbuf;
2602	ctx->engine[ring->id].state = ctx_obj;
2603
2604	if (ctx != ctx->i915->kernel_context && ring->init_context) {
2605		struct drm_i915_gem_request *req;
2606
2607		req = i915_gem_request_alloc(ring, ctx);
2608		if (IS_ERR(req)) {
2609			ret = PTR_ERR(req);
2610			DRM_ERROR("ring create req: %d\n", ret);
2611			goto error_ringbuf;
2612		}
2613
2614		ret = ring->init_context(req);
2615		if (ret) {
2616			DRM_ERROR("ring init context: %d\n",
2617				ret);
2618			i915_gem_request_cancel(req);
2619			goto error_ringbuf;
2620		}
2621		i915_add_request_no_flush(req);
2622	}
2623	return 0;
2624
2625error_ringbuf:
2626	intel_ringbuffer_free(ringbuf);
2627error_deref_obj:
2628	drm_gem_object_unreference(&ctx_obj->base);
2629	ctx->engine[ring->id].ringbuf = NULL;
2630	ctx->engine[ring->id].state = NULL;
2631	return ret;
2632}
2633
2634void intel_lr_context_reset(struct drm_device *dev,
2635			struct intel_context *ctx)
2636{
2637	struct drm_i915_private *dev_priv = dev->dev_private;
2638	struct intel_engine_cs *ring;
2639	int i;
2640
2641	for_each_ring(ring, dev_priv, i) {
2642		struct drm_i915_gem_object *ctx_obj =
2643				ctx->engine[ring->id].state;
2644		struct intel_ringbuffer *ringbuf =
2645				ctx->engine[ring->id].ringbuf;
2646		uint32_t *reg_state;
2647		struct page *page;
2648
2649		if (!ctx_obj)
2650			continue;
2651
2652		if (i915_gem_object_get_pages(ctx_obj)) {
2653			WARN(1, "Failed get_pages for context obj\n");
2654			continue;
2655		}
2656		page = i915_gem_object_get_dirty_page(ctx_obj, LRC_STATE_PN);
2657		reg_state = kmap_atomic(page);
2658
2659		reg_state[CTX_RING_HEAD+1] = 0;
2660		reg_state[CTX_RING_TAIL+1] = 0;
2661
2662		kunmap_atomic(reg_state);
2663
2664		ringbuf->head = 0;
2665		ringbuf->tail = 0;
2666	}
2667}