xref: /dragonfly/sys/dev/drm/i915/intel_ringbuffer.c (revision 5ca0a96d)
1 /*
2  * Copyright © 2008-2010 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  *    Eric Anholt <eric@anholt.net>
25  *    Zou Nan hai <nanhai.zou@intel.com>
26  *    Xiang Hai hao<haihao.xiang@intel.com>
27  *
28  */
29 
30 #include <linux/log2.h>
31 #include <drm/drmP.h>
32 #include "i915_drv.h"
33 #include <drm/i915_drm.h>
34 #include "i915_trace.h"
35 #include "intel_drv.h"
36 
37 /* Rough estimate of the typical request size, performing a flush,
38  * set-context and then emitting the batch.
39  */
40 #define LEGACY_REQUEST_SIZE 200
41 
42 static unsigned int __intel_ring_space(unsigned int head,
43 				       unsigned int tail,
44 				       unsigned int size)
45 {
46 	/*
47 	 * "If the Ring Buffer Head Pointer and the Tail Pointer are on the
48 	 * same cacheline, the Head Pointer must not be greater than the Tail
49 	 * Pointer."
50 	 */
51 	GEM_BUG_ON(!is_power_of_2(size));
52 	return (head - tail - CACHELINE_BYTES) & (size - 1);
53 }
54 
55 unsigned int intel_ring_update_space(struct intel_ring *ring)
56 {
57 	unsigned int space;
58 
59 	space = __intel_ring_space(ring->head, ring->emit, ring->size);
60 
61 	ring->space = space;
62 	return space;
63 }
64 
65 static int
66 gen2_render_ring_flush(struct drm_i915_gem_request *req, u32 mode)
67 {
68 	u32 cmd, *cs;
69 
70 	cmd = MI_FLUSH;
71 
72 	if (mode & EMIT_INVALIDATE)
73 		cmd |= MI_READ_FLUSH;
74 
75 	cs = intel_ring_begin(req, 2);
76 	if (IS_ERR(cs))
77 		return PTR_ERR(cs);
78 
79 	*cs++ = cmd;
80 	*cs++ = MI_NOOP;
81 	intel_ring_advance(req, cs);
82 
83 	return 0;
84 }
85 
86 static int
87 gen4_render_ring_flush(struct drm_i915_gem_request *req, u32 mode)
88 {
89 	u32 cmd, *cs;
90 
91 	/*
92 	 * read/write caches:
93 	 *
94 	 * I915_GEM_DOMAIN_RENDER is always invalidated, but is
95 	 * only flushed if MI_NO_WRITE_FLUSH is unset.  On 965, it is
96 	 * also flushed at 2d versus 3d pipeline switches.
97 	 *
98 	 * read-only caches:
99 	 *
100 	 * I915_GEM_DOMAIN_SAMPLER is flushed on pre-965 if
101 	 * MI_READ_FLUSH is set, and is always flushed on 965.
102 	 *
103 	 * I915_GEM_DOMAIN_COMMAND may not exist?
104 	 *
105 	 * I915_GEM_DOMAIN_INSTRUCTION, which exists on 965, is
106 	 * invalidated when MI_EXE_FLUSH is set.
107 	 *
108 	 * I915_GEM_DOMAIN_VERTEX, which exists on 965, is
109 	 * invalidated with every MI_FLUSH.
110 	 *
111 	 * TLBs:
112 	 *
113 	 * On 965, TLBs associated with I915_GEM_DOMAIN_COMMAND
114 	 * and I915_GEM_DOMAIN_CPU in are invalidated at PTE write and
115 	 * I915_GEM_DOMAIN_RENDER and I915_GEM_DOMAIN_SAMPLER
116 	 * are flushed at any MI_FLUSH.
117 	 */
118 
119 	cmd = MI_FLUSH;
120 	if (mode & EMIT_INVALIDATE) {
121 		cmd |= MI_EXE_FLUSH;
122 		if (IS_G4X(req->i915) || IS_GEN5(req->i915))
123 			cmd |= MI_INVALIDATE_ISP;
124 	}
125 
126 	cs = intel_ring_begin(req, 2);
127 	if (IS_ERR(cs))
128 		return PTR_ERR(cs);
129 
130 	*cs++ = cmd;
131 	*cs++ = MI_NOOP;
132 	intel_ring_advance(req, cs);
133 
134 	return 0;
135 }
136 
137 /**
138  * Emits a PIPE_CONTROL with a non-zero post-sync operation, for
139  * implementing two workarounds on gen6.  From section 1.4.7.1
140  * "PIPE_CONTROL" of the Sandy Bridge PRM volume 2 part 1:
141  *
142  * [DevSNB-C+{W/A}] Before any depth stall flush (including those
143  * produced by non-pipelined state commands), software needs to first
144  * send a PIPE_CONTROL with no bits set except Post-Sync Operation !=
145  * 0.
146  *
147  * [Dev-SNB{W/A}]: Before a PIPE_CONTROL with Write Cache Flush Enable
148  * =1, a PIPE_CONTROL with any non-zero post-sync-op is required.
149  *
150  * And the workaround for these two requires this workaround first:
151  *
152  * [Dev-SNB{W/A}]: Pipe-control with CS-stall bit set must be sent
153  * BEFORE the pipe-control with a post-sync op and no write-cache
154  * flushes.
155  *
156  * And this last workaround is tricky because of the requirements on
157  * that bit.  From section 1.4.7.2.3 "Stall" of the Sandy Bridge PRM
158  * volume 2 part 1:
159  *
160  *     "1 of the following must also be set:
161  *      - Render Target Cache Flush Enable ([12] of DW1)
162  *      - Depth Cache Flush Enable ([0] of DW1)
163  *      - Stall at Pixel Scoreboard ([1] of DW1)
164  *      - Depth Stall ([13] of DW1)
165  *      - Post-Sync Operation ([13] of DW1)
166  *      - Notify Enable ([8] of DW1)"
167  *
168  * The cache flushes require the workaround flush that triggered this
169  * one, so we can't use it.  Depth stall would trigger the same.
170  * Post-sync nonzero is what triggered this second workaround, so we
171  * can't use that one either.  Notify enable is IRQs, which aren't
172  * really our business.  That leaves only stall at scoreboard.
173  */
174 static int
175 intel_emit_post_sync_nonzero_flush(struct drm_i915_gem_request *req)
176 {
177 	u32 scratch_addr =
178 		i915_ggtt_offset(req->engine->scratch) + 2 * CACHELINE_BYTES;
179 	u32 *cs;
180 
181 	cs = intel_ring_begin(req, 6);
182 	if (IS_ERR(cs))
183 		return PTR_ERR(cs);
184 
185 	*cs++ = GFX_OP_PIPE_CONTROL(5);
186 	*cs++ = PIPE_CONTROL_CS_STALL | PIPE_CONTROL_STALL_AT_SCOREBOARD;
187 	*cs++ = scratch_addr | PIPE_CONTROL_GLOBAL_GTT;
188 	*cs++ = 0; /* low dword */
189 	*cs++ = 0; /* high dword */
190 	*cs++ = MI_NOOP;
191 	intel_ring_advance(req, cs);
192 
193 	cs = intel_ring_begin(req, 6);
194 	if (IS_ERR(cs))
195 		return PTR_ERR(cs);
196 
197 	*cs++ = GFX_OP_PIPE_CONTROL(5);
198 	*cs++ = PIPE_CONTROL_QW_WRITE;
199 	*cs++ = scratch_addr | PIPE_CONTROL_GLOBAL_GTT;
200 	*cs++ = 0;
201 	*cs++ = 0;
202 	*cs++ = MI_NOOP;
203 	intel_ring_advance(req, cs);
204 
205 	return 0;
206 }
207 
208 static int
209 gen6_render_ring_flush(struct drm_i915_gem_request *req, u32 mode)
210 {
211 	u32 scratch_addr =
212 		i915_ggtt_offset(req->engine->scratch) + 2 * CACHELINE_BYTES;
213 	u32 *cs, flags = 0;
214 	int ret;
215 
216 	/* Force SNB workarounds for PIPE_CONTROL flushes */
217 	ret = intel_emit_post_sync_nonzero_flush(req);
218 	if (ret)
219 		return ret;
220 
221 	/* Just flush everything.  Experiments have shown that reducing the
222 	 * number of bits based on the write domains has little performance
223 	 * impact.
224 	 */
225 	if (mode & EMIT_FLUSH) {
226 		flags |= PIPE_CONTROL_RENDER_TARGET_CACHE_FLUSH;
227 		flags |= PIPE_CONTROL_DEPTH_CACHE_FLUSH;
228 		/*
229 		 * Ensure that any following seqno writes only happen
230 		 * when the render cache is indeed flushed.
231 		 */
232 		flags |= PIPE_CONTROL_CS_STALL;
233 	}
234 	if (mode & EMIT_INVALIDATE) {
235 		flags |= PIPE_CONTROL_TLB_INVALIDATE;
236 		flags |= PIPE_CONTROL_INSTRUCTION_CACHE_INVALIDATE;
237 		flags |= PIPE_CONTROL_TEXTURE_CACHE_INVALIDATE;
238 		flags |= PIPE_CONTROL_VF_CACHE_INVALIDATE;
239 		flags |= PIPE_CONTROL_CONST_CACHE_INVALIDATE;
240 		flags |= PIPE_CONTROL_STATE_CACHE_INVALIDATE;
241 		/*
242 		 * TLB invalidate requires a post-sync write.
243 		 */
244 		flags |= PIPE_CONTROL_QW_WRITE | PIPE_CONTROL_CS_STALL;
245 	}
246 
247 	cs = intel_ring_begin(req, 4);
248 	if (IS_ERR(cs))
249 		return PTR_ERR(cs);
250 
251 	*cs++ = GFX_OP_PIPE_CONTROL(4);
252 	*cs++ = flags;
253 	*cs++ = scratch_addr | PIPE_CONTROL_GLOBAL_GTT;
254 	*cs++ = 0;
255 	intel_ring_advance(req, cs);
256 
257 	return 0;
258 }
259 
260 static int
261 gen7_render_ring_cs_stall_wa(struct drm_i915_gem_request *req)
262 {
263 	u32 *cs;
264 
265 	cs = intel_ring_begin(req, 4);
266 	if (IS_ERR(cs))
267 		return PTR_ERR(cs);
268 
269 	*cs++ = GFX_OP_PIPE_CONTROL(4);
270 	*cs++ = PIPE_CONTROL_CS_STALL | PIPE_CONTROL_STALL_AT_SCOREBOARD;
271 	*cs++ = 0;
272 	*cs++ = 0;
273 	intel_ring_advance(req, cs);
274 
275 	return 0;
276 }
277 
278 static int
279 gen7_render_ring_flush(struct drm_i915_gem_request *req, u32 mode)
280 {
281 	u32 scratch_addr =
282 		i915_ggtt_offset(req->engine->scratch) + 2 * CACHELINE_BYTES;
283 	u32 *cs, flags = 0;
284 
285 	/*
286 	 * Ensure that any following seqno writes only happen when the render
287 	 * cache is indeed flushed.
288 	 *
289 	 * Workaround: 4th PIPE_CONTROL command (except the ones with only
290 	 * read-cache invalidate bits set) must have the CS_STALL bit set. We
291 	 * don't try to be clever and just set it unconditionally.
292 	 */
293 	flags |= PIPE_CONTROL_CS_STALL;
294 
295 	/* Just flush everything.  Experiments have shown that reducing the
296 	 * number of bits based on the write domains has little performance
297 	 * impact.
298 	 */
299 	if (mode & EMIT_FLUSH) {
300 		flags |= PIPE_CONTROL_RENDER_TARGET_CACHE_FLUSH;
301 		flags |= PIPE_CONTROL_DEPTH_CACHE_FLUSH;
302 		flags |= PIPE_CONTROL_DC_FLUSH_ENABLE;
303 		flags |= PIPE_CONTROL_FLUSH_ENABLE;
304 	}
305 	if (mode & EMIT_INVALIDATE) {
306 		flags |= PIPE_CONTROL_TLB_INVALIDATE;
307 		flags |= PIPE_CONTROL_INSTRUCTION_CACHE_INVALIDATE;
308 		flags |= PIPE_CONTROL_TEXTURE_CACHE_INVALIDATE;
309 		flags |= PIPE_CONTROL_VF_CACHE_INVALIDATE;
310 		flags |= PIPE_CONTROL_CONST_CACHE_INVALIDATE;
311 		flags |= PIPE_CONTROL_STATE_CACHE_INVALIDATE;
312 		flags |= PIPE_CONTROL_MEDIA_STATE_CLEAR;
313 		/*
314 		 * TLB invalidate requires a post-sync write.
315 		 */
316 		flags |= PIPE_CONTROL_QW_WRITE;
317 		flags |= PIPE_CONTROL_GLOBAL_GTT_IVB;
318 
319 		flags |= PIPE_CONTROL_STALL_AT_SCOREBOARD;
320 
321 		/* Workaround: we must issue a pipe_control with CS-stall bit
322 		 * set before a pipe_control command that has the state cache
323 		 * invalidate bit set. */
324 		gen7_render_ring_cs_stall_wa(req);
325 	}
326 
327 	cs = intel_ring_begin(req, 4);
328 	if (IS_ERR(cs))
329 		return PTR_ERR(cs);
330 
331 	*cs++ = GFX_OP_PIPE_CONTROL(4);
332 	*cs++ = flags;
333 	*cs++ = scratch_addr;
334 	*cs++ = 0;
335 	intel_ring_advance(req, cs);
336 
337 	return 0;
338 }
339 
340 static int
341 gen8_render_ring_flush(struct drm_i915_gem_request *req, u32 mode)
342 {
343 	u32 flags;
344 	u32 *cs;
345 
346 	cs = intel_ring_begin(req, mode & EMIT_INVALIDATE ? 12 : 6);
347 	if (IS_ERR(cs))
348 		return PTR_ERR(cs);
349 
350 	flags = PIPE_CONTROL_CS_STALL;
351 
352 	if (mode & EMIT_FLUSH) {
353 		flags |= PIPE_CONTROL_RENDER_TARGET_CACHE_FLUSH;
354 		flags |= PIPE_CONTROL_DEPTH_CACHE_FLUSH;
355 		flags |= PIPE_CONTROL_DC_FLUSH_ENABLE;
356 		flags |= PIPE_CONTROL_FLUSH_ENABLE;
357 	}
358 	if (mode & EMIT_INVALIDATE) {
359 		flags |= PIPE_CONTROL_TLB_INVALIDATE;
360 		flags |= PIPE_CONTROL_INSTRUCTION_CACHE_INVALIDATE;
361 		flags |= PIPE_CONTROL_TEXTURE_CACHE_INVALIDATE;
362 		flags |= PIPE_CONTROL_VF_CACHE_INVALIDATE;
363 		flags |= PIPE_CONTROL_CONST_CACHE_INVALIDATE;
364 		flags |= PIPE_CONTROL_STATE_CACHE_INVALIDATE;
365 		flags |= PIPE_CONTROL_QW_WRITE;
366 		flags |= PIPE_CONTROL_GLOBAL_GTT_IVB;
367 
368 		/* WaCsStallBeforeStateCacheInvalidate:bdw,chv */
369 		cs = gen8_emit_pipe_control(cs,
370 					    PIPE_CONTROL_CS_STALL |
371 					    PIPE_CONTROL_STALL_AT_SCOREBOARD,
372 					    0);
373 	}
374 
375 	cs = gen8_emit_pipe_control(cs, flags,
376 				    i915_ggtt_offset(req->engine->scratch) +
377 				    2 * CACHELINE_BYTES);
378 
379 	intel_ring_advance(req, cs);
380 
381 	return 0;
382 }
383 
384 static void ring_setup_phys_status_page(struct intel_engine_cs *engine)
385 {
386 	struct drm_i915_private *dev_priv = engine->i915;
387 	u32 addr;
388 
389 	addr = dev_priv->status_page_dmah->busaddr;
390 	if (INTEL_GEN(dev_priv) >= 4)
391 		addr |= (dev_priv->status_page_dmah->busaddr >> 28) & 0xf0;
392 	I915_WRITE(HWS_PGA, addr);
393 }
394 
395 static void intel_ring_setup_status_page(struct intel_engine_cs *engine)
396 {
397 	struct drm_i915_private *dev_priv = engine->i915;
398 	i915_reg_t mmio;
399 
400 	/* The ring status page addresses are no longer next to the rest of
401 	 * the ring registers as of gen7.
402 	 */
403 	if (IS_GEN7(dev_priv)) {
404 		switch (engine->id) {
405 		/*
406 		 * No more rings exist on Gen7. Default case is only to shut up
407 		 * gcc switch check warning.
408 		 */
409 		default:
410 			GEM_BUG_ON(engine->id);
411 		case RCS:
412 			mmio = RENDER_HWS_PGA_GEN7;
413 			break;
414 		case BCS:
415 			mmio = BLT_HWS_PGA_GEN7;
416 			break;
417 		case VCS:
418 			mmio = BSD_HWS_PGA_GEN7;
419 			break;
420 		case VECS:
421 			mmio = VEBOX_HWS_PGA_GEN7;
422 			break;
423 		}
424 	} else if (IS_GEN6(dev_priv)) {
425 		mmio = RING_HWS_PGA_GEN6(engine->mmio_base);
426 	} else {
427 		/* XXX: gen8 returns to sanity */
428 		mmio = RING_HWS_PGA(engine->mmio_base);
429 	}
430 
431 	if (INTEL_GEN(dev_priv) >= 6)
432 		I915_WRITE(RING_HWSTAM(engine->mmio_base), 0xffffffff);
433 
434 	I915_WRITE(mmio, engine->status_page.ggtt_offset);
435 	POSTING_READ(mmio);
436 
437 	/*
438 	 * Flush the TLB for this page
439 	 *
440 	 * FIXME: These two bits have disappeared on gen8, so a question
441 	 * arises: do we still need this and if so how should we go about
442 	 * invalidating the TLB?
443 	 */
444 	if (IS_GEN(dev_priv, 6, 7)) {
445 		i915_reg_t reg = RING_INSTPM(engine->mmio_base);
446 
447 		/* ring should be idle before issuing a sync flush*/
448 		WARN_ON((I915_READ_MODE(engine) & MODE_IDLE) == 0);
449 
450 		I915_WRITE(reg,
451 			   _MASKED_BIT_ENABLE(INSTPM_TLB_INVALIDATE |
452 					      INSTPM_SYNC_FLUSH));
453 		if (intel_wait_for_register(dev_priv,
454 					    reg, INSTPM_SYNC_FLUSH, 0,
455 					    1000))
456 			DRM_ERROR("%s: wait for SyncFlush to complete for TLB invalidation timed out\n",
457 				  engine->name);
458 	}
459 }
460 
461 static bool stop_ring(struct intel_engine_cs *engine)
462 {
463 	struct drm_i915_private *dev_priv = engine->i915;
464 
465 	if (INTEL_GEN(dev_priv) > 2) {
466 		I915_WRITE_MODE(engine, _MASKED_BIT_ENABLE(STOP_RING));
467 		if (intel_wait_for_register(dev_priv,
468 					    RING_MI_MODE(engine->mmio_base),
469 					    MODE_IDLE,
470 					    MODE_IDLE,
471 					    1000)) {
472 			DRM_ERROR("%s : timed out trying to stop ring\n",
473 				  engine->name);
474 			/* Sometimes we observe that the idle flag is not
475 			 * set even though the ring is empty. So double
476 			 * check before giving up.
477 			 */
478 			if (I915_READ_HEAD(engine) != I915_READ_TAIL(engine))
479 				return false;
480 		}
481 	}
482 
483 	I915_WRITE_CTL(engine, 0);
484 	I915_WRITE_HEAD(engine, 0);
485 	I915_WRITE_TAIL(engine, 0);
486 
487 	return (I915_READ_HEAD(engine) & HEAD_ADDR) == 0;
488 }
489 
490 static int init_ring_common(struct intel_engine_cs *engine)
491 {
492 	struct drm_i915_private *dev_priv = engine->i915;
493 	struct intel_ring *ring = engine->buffer;
494 	int ret = 0;
495 
496 	intel_uncore_forcewake_get(dev_priv, FORCEWAKE_ALL);
497 
498 	if (!stop_ring(engine)) {
499 		/* G45 ring initialization often fails to reset head to zero */
500 		DRM_DEBUG_KMS("%s head not reset to zero "
501 			      "ctl %08x head %08x tail %08x start %08x\n",
502 			      engine->name,
503 			      I915_READ_CTL(engine),
504 			      I915_READ_HEAD(engine),
505 			      I915_READ_TAIL(engine),
506 			      I915_READ_START(engine));
507 
508 		if (!stop_ring(engine)) {
509 			DRM_ERROR("failed to set %s head to zero "
510 				  "ctl %08x head %08x tail %08x start %08x\n",
511 				  engine->name,
512 				  I915_READ_CTL(engine),
513 				  I915_READ_HEAD(engine),
514 				  I915_READ_TAIL(engine),
515 				  I915_READ_START(engine));
516 			ret = -EIO;
517 			goto out;
518 		}
519 	}
520 
521 	if (HWS_NEEDS_PHYSICAL(dev_priv))
522 		ring_setup_phys_status_page(engine);
523 	else
524 		intel_ring_setup_status_page(engine);
525 
526 	intel_engine_reset_breadcrumbs(engine);
527 
528 	/* Enforce ordering by reading HEAD register back */
529 	I915_READ_HEAD(engine);
530 
531 	/* Initialize the ring. This must happen _after_ we've cleared the ring
532 	 * registers with the above sequence (the readback of the HEAD registers
533 	 * also enforces ordering), otherwise the hw might lose the new ring
534 	 * register values. */
535 	I915_WRITE_START(engine, i915_ggtt_offset(ring->vma));
536 
537 	/* WaClearRingBufHeadRegAtInit:ctg,elk */
538 	if (I915_READ_HEAD(engine))
539 		DRM_DEBUG("%s initialization failed [head=%08x], fudging\n",
540 			  engine->name, I915_READ_HEAD(engine));
541 
542 	intel_ring_update_space(ring);
543 	I915_WRITE_HEAD(engine, ring->head);
544 	I915_WRITE_TAIL(engine, ring->tail);
545 	(void)I915_READ_TAIL(engine);
546 
547 	I915_WRITE_CTL(engine, RING_CTL_SIZE(ring->size) | RING_VALID);
548 
549 	/* If the head is still not zero, the ring is dead */
550 	if (intel_wait_for_register(dev_priv, RING_CTL(engine->mmio_base),
551 				    RING_VALID, RING_VALID,
552 				    50)) {
553 		DRM_ERROR("%s initialization failed "
554 			  "ctl %08x (valid? %d) head %08x [%08x] tail %08x [%08x] start %08x [expected %08x]\n",
555 			  engine->name,
556 			  I915_READ_CTL(engine),
557 			  I915_READ_CTL(engine) & RING_VALID,
558 			  I915_READ_HEAD(engine), ring->head,
559 			  I915_READ_TAIL(engine), ring->tail,
560 			  I915_READ_START(engine),
561 			  i915_ggtt_offset(ring->vma));
562 		ret = -EIO;
563 		goto out;
564 	}
565 
566 	intel_engine_init_hangcheck(engine);
567 
568 	if (INTEL_GEN(dev_priv) > 2)
569 		I915_WRITE_MODE(engine, _MASKED_BIT_DISABLE(STOP_RING));
570 
571 out:
572 	intel_uncore_forcewake_put(dev_priv, FORCEWAKE_ALL);
573 
574 	return ret;
575 }
576 
577 static void reset_ring_common(struct intel_engine_cs *engine,
578 			      struct drm_i915_gem_request *request)
579 {
580 	/*
581 	 * RC6 must be prevented until the reset is complete and the engine
582 	 * reinitialised. If it occurs in the middle of this sequence, the
583 	 * state written to/loaded from the power context is ill-defined (e.g.
584 	 * the PP_BASE_DIR may be lost).
585 	 */
586 	assert_forcewakes_active(engine->i915, FORCEWAKE_ALL);
587 
588 	/*
589 	 * Try to restore the logical GPU state to match the continuation
590 	 * of the request queue. If we skip the context/PD restore, then
591 	 * the next request may try to execute assuming that its context
592 	 * is valid and loaded on the GPU and so may try to access invalid
593 	 * memory, prompting repeated GPU hangs.
594 	 *
595 	 * If the request was guilty, we still restore the logical state
596 	 * in case the next request requires it (e.g. the aliasing ppgtt),
597 	 * but skip over the hung batch.
598 	 *
599 	 * If the request was innocent, we try to replay the request with
600 	 * the restored context.
601 	 */
602 	if (request) {
603 		struct drm_i915_private *dev_priv = request->i915;
604 		struct intel_context *ce = &request->ctx->engine[engine->id];
605 		struct i915_hw_ppgtt *ppgtt;
606 
607 		/* FIXME consider gen8 reset */
608 
609 		if (ce->state) {
610 			I915_WRITE(CCID,
611 				   i915_ggtt_offset(ce->state) |
612 				   BIT(8) /* must be set! */ |
613 				   CCID_EXTENDED_STATE_SAVE |
614 				   CCID_EXTENDED_STATE_RESTORE |
615 				   CCID_EN);
616 		}
617 
618 		ppgtt = request->ctx->ppgtt ?: engine->i915->mm.aliasing_ppgtt;
619 		if (ppgtt) {
620 			u32 pd_offset = ppgtt->pd.base.ggtt_offset << 10;
621 
622 			I915_WRITE(RING_PP_DIR_DCLV(engine), PP_DIR_DCLV_2G);
623 			I915_WRITE(RING_PP_DIR_BASE(engine), pd_offset);
624 
625 			/* Wait for the PD reload to complete */
626 			if (intel_wait_for_register(dev_priv,
627 						    RING_PP_DIR_BASE(engine),
628 						    BIT(0), 0,
629 						    10))
630 				DRM_ERROR("Wait for reload of ppgtt page-directory timed out\n");
631 
632 			ppgtt->pd_dirty_rings &= ~intel_engine_flag(engine);
633 		}
634 
635 		/* If the rq hung, jump to its breadcrumb and skip the batch */
636 		if (request->fence.error == -EIO)
637 			request->ring->head = request->postfix;
638 	} else {
639 		engine->legacy_active_context = NULL;
640 	}
641 }
642 
643 static int intel_rcs_ctx_init(struct drm_i915_gem_request *req)
644 {
645 	int ret;
646 
647 	ret = intel_ring_workarounds_emit(req);
648 	if (ret != 0)
649 		return ret;
650 
651 	ret = i915_gem_render_state_emit(req);
652 	if (ret)
653 		return ret;
654 
655 	return 0;
656 }
657 
658 static int init_render_ring(struct intel_engine_cs *engine)
659 {
660 	struct drm_i915_private *dev_priv = engine->i915;
661 	int ret = init_ring_common(engine);
662 	if (ret)
663 		return ret;
664 
665 	/* WaTimedSingleVertexDispatch:cl,bw,ctg,elk,ilk,snb */
666 	if (IS_GEN(dev_priv, 4, 6))
667 		I915_WRITE(MI_MODE, _MASKED_BIT_ENABLE(VS_TIMER_DISPATCH));
668 
669 	/* We need to disable the AsyncFlip performance optimisations in order
670 	 * to use MI_WAIT_FOR_EVENT within the CS. It should already be
671 	 * programmed to '1' on all products.
672 	 *
673 	 * WaDisableAsyncFlipPerfMode:snb,ivb,hsw,vlv
674 	 */
675 	if (IS_GEN(dev_priv, 6, 7))
676 		I915_WRITE(MI_MODE, _MASKED_BIT_ENABLE(ASYNC_FLIP_PERF_DISABLE));
677 
678 	/* Required for the hardware to program scanline values for waiting */
679 	/* WaEnableFlushTlbInvalidationMode:snb */
680 	if (IS_GEN6(dev_priv))
681 		I915_WRITE(GFX_MODE,
682 			   _MASKED_BIT_ENABLE(GFX_TLB_INVALIDATE_EXPLICIT));
683 
684 	/* WaBCSVCSTlbInvalidationMode:ivb,vlv,hsw */
685 	if (IS_GEN7(dev_priv))
686 		I915_WRITE(GFX_MODE_GEN7,
687 			   _MASKED_BIT_ENABLE(GFX_TLB_INVALIDATE_EXPLICIT) |
688 			   _MASKED_BIT_ENABLE(GFX_REPLAY_MODE));
689 
690 	if (IS_GEN6(dev_priv)) {
691 		/* From the Sandybridge PRM, volume 1 part 3, page 24:
692 		 * "If this bit is set, STCunit will have LRA as replacement
693 		 *  policy. [...] This bit must be reset.  LRA replacement
694 		 *  policy is not supported."
695 		 */
696 		I915_WRITE(CACHE_MODE_0,
697 			   _MASKED_BIT_DISABLE(CM0_STC_EVICT_DISABLE_LRA_SNB));
698 	}
699 
700 	if (IS_GEN(dev_priv, 6, 7))
701 		I915_WRITE(INSTPM, _MASKED_BIT_ENABLE(INSTPM_FORCE_ORDERING));
702 
703 	if (INTEL_INFO(dev_priv)->gen >= 6)
704 		I915_WRITE_IMR(engine, ~engine->irq_keep_mask);
705 
706 	return init_workarounds_ring(engine);
707 }
708 
709 static void render_ring_cleanup(struct intel_engine_cs *engine)
710 {
711 	struct drm_i915_private *dev_priv = engine->i915;
712 
713 	i915_vma_unpin_and_release(&dev_priv->semaphore);
714 }
715 
716 static u32 *gen8_rcs_signal(struct drm_i915_gem_request *req, u32 *cs)
717 {
718 	struct drm_i915_private *dev_priv = req->i915;
719 	struct intel_engine_cs *waiter;
720 	enum intel_engine_id id;
721 
722 	for_each_engine(waiter, dev_priv, id) {
723 		u64 gtt_offset = req->engine->semaphore.signal_ggtt[id];
724 		if (gtt_offset == MI_SEMAPHORE_SYNC_INVALID)
725 			continue;
726 
727 		*cs++ = GFX_OP_PIPE_CONTROL(6);
728 		*cs++ = PIPE_CONTROL_GLOBAL_GTT_IVB | PIPE_CONTROL_QW_WRITE |
729 			PIPE_CONTROL_CS_STALL;
730 		*cs++ = lower_32_bits(gtt_offset);
731 		*cs++ = upper_32_bits(gtt_offset);
732 		*cs++ = req->global_seqno;
733 		*cs++ = 0;
734 		*cs++ = MI_SEMAPHORE_SIGNAL |
735 			MI_SEMAPHORE_TARGET(waiter->hw_id);
736 		*cs++ = 0;
737 	}
738 
739 	return cs;
740 }
741 
742 static u32 *gen8_xcs_signal(struct drm_i915_gem_request *req, u32 *cs)
743 {
744 	struct drm_i915_private *dev_priv = req->i915;
745 	struct intel_engine_cs *waiter;
746 	enum intel_engine_id id;
747 
748 	for_each_engine(waiter, dev_priv, id) {
749 		u64 gtt_offset = req->engine->semaphore.signal_ggtt[id];
750 		if (gtt_offset == MI_SEMAPHORE_SYNC_INVALID)
751 			continue;
752 
753 		*cs++ = (MI_FLUSH_DW + 1) | MI_FLUSH_DW_OP_STOREDW;
754 		*cs++ = lower_32_bits(gtt_offset) | MI_FLUSH_DW_USE_GTT;
755 		*cs++ = upper_32_bits(gtt_offset);
756 		*cs++ = req->global_seqno;
757 		*cs++ = MI_SEMAPHORE_SIGNAL |
758 			MI_SEMAPHORE_TARGET(waiter->hw_id);
759 		*cs++ = 0;
760 	}
761 
762 	return cs;
763 }
764 
765 static u32 *gen6_signal(struct drm_i915_gem_request *req, u32 *cs)
766 {
767 	struct drm_i915_private *dev_priv = req->i915;
768 	struct intel_engine_cs *engine;
769 	enum intel_engine_id id;
770 	int num_rings = 0;
771 
772 	for_each_engine(engine, dev_priv, id) {
773 		i915_reg_t mbox_reg;
774 
775 		if (!(BIT(engine->hw_id) & GEN6_SEMAPHORES_MASK))
776 			continue;
777 
778 		mbox_reg = req->engine->semaphore.mbox.signal[engine->hw_id];
779 		if (i915_mmio_reg_valid(mbox_reg)) {
780 			*cs++ = MI_LOAD_REGISTER_IMM(1);
781 			*cs++ = i915_mmio_reg_offset(mbox_reg);
782 			*cs++ = req->global_seqno;
783 			num_rings++;
784 		}
785 	}
786 	if (num_rings & 1)
787 		*cs++ = MI_NOOP;
788 
789 	return cs;
790 }
791 
792 static void cancel_requests(struct intel_engine_cs *engine)
793 {
794 	struct drm_i915_gem_request *request;
795 	unsigned long flags;
796 
797 	spin_lock_irqsave(&engine->timeline->lock, flags);
798 
799 	/* Mark all submitted requests as skipped. */
800 	list_for_each_entry(request, &engine->timeline->requests, link) {
801 		GEM_BUG_ON(!request->global_seqno);
802 		if (!i915_gem_request_completed(request))
803 			dma_fence_set_error(&request->fence, -EIO);
804 	}
805 	/* Remaining _unready_ requests will be nop'ed when submitted */
806 
807 	spin_unlock_irqrestore(&engine->timeline->lock, flags);
808 }
809 
810 static void i9xx_submit_request(struct drm_i915_gem_request *request)
811 {
812 	struct drm_i915_private *dev_priv = request->i915;
813 
814 	i915_gem_request_submit(request);
815 
816 	I915_WRITE_TAIL(request->engine,
817 			intel_ring_set_tail(request->ring, request->tail));
818 }
819 
820 static void i9xx_emit_breadcrumb(struct drm_i915_gem_request *req, u32 *cs)
821 {
822 	*cs++ = MI_STORE_DWORD_INDEX;
823 	*cs++ = I915_GEM_HWS_INDEX << MI_STORE_DWORD_INDEX_SHIFT;
824 	*cs++ = req->global_seqno;
825 	*cs++ = MI_USER_INTERRUPT;
826 
827 	req->tail = intel_ring_offset(req, cs);
828 	assert_ring_tail_valid(req->ring, req->tail);
829 }
830 
831 static const int i9xx_emit_breadcrumb_sz = 4;
832 
833 /**
834  * gen6_sema_emit_breadcrumb - Update the semaphore mailbox registers
835  *
836  * @request - request to write to the ring
837  *
838  * Update the mailbox registers in the *other* rings with the current seqno.
839  * This acts like a signal in the canonical semaphore.
840  */
841 static void gen6_sema_emit_breadcrumb(struct drm_i915_gem_request *req, u32 *cs)
842 {
843 	return i9xx_emit_breadcrumb(req,
844 				    req->engine->semaphore.signal(req, cs));
845 }
846 
847 static void gen8_render_emit_breadcrumb(struct drm_i915_gem_request *req,
848 					u32 *cs)
849 {
850 	struct intel_engine_cs *engine = req->engine;
851 
852 	if (engine->semaphore.signal)
853 		cs = engine->semaphore.signal(req, cs);
854 
855 	*cs++ = GFX_OP_PIPE_CONTROL(6);
856 	*cs++ = PIPE_CONTROL_GLOBAL_GTT_IVB | PIPE_CONTROL_CS_STALL |
857 		PIPE_CONTROL_QW_WRITE;
858 	*cs++ = intel_hws_seqno_address(engine);
859 	*cs++ = 0;
860 	*cs++ = req->global_seqno;
861 	/* We're thrashing one dword of HWS. */
862 	*cs++ = 0;
863 	*cs++ = MI_USER_INTERRUPT;
864 	*cs++ = MI_NOOP;
865 
866 	req->tail = intel_ring_offset(req, cs);
867 	assert_ring_tail_valid(req->ring, req->tail);
868 }
869 
870 static const int gen8_render_emit_breadcrumb_sz = 8;
871 
872 /**
873  * intel_ring_sync - sync the waiter to the signaller on seqno
874  *
875  * @waiter - ring that is waiting
876  * @signaller - ring which has, or will signal
877  * @seqno - seqno which the waiter will block on
878  */
879 
880 static int
881 gen8_ring_sync_to(struct drm_i915_gem_request *req,
882 		  struct drm_i915_gem_request *signal)
883 {
884 	struct drm_i915_private *dev_priv = req->i915;
885 	u64 offset = GEN8_WAIT_OFFSET(req->engine, signal->engine->id);
886 	struct i915_hw_ppgtt *ppgtt;
887 	u32 *cs;
888 
889 	cs = intel_ring_begin(req, 4);
890 	if (IS_ERR(cs))
891 		return PTR_ERR(cs);
892 
893 	*cs++ = MI_SEMAPHORE_WAIT | MI_SEMAPHORE_GLOBAL_GTT |
894 		MI_SEMAPHORE_SAD_GTE_SDD;
895 	*cs++ = signal->global_seqno;
896 	*cs++ = lower_32_bits(offset);
897 	*cs++ = upper_32_bits(offset);
898 	intel_ring_advance(req, cs);
899 
900 	/* When the !RCS engines idle waiting upon a semaphore, they lose their
901 	 * pagetables and we must reload them before executing the batch.
902 	 * We do this on the i915_switch_context() following the wait and
903 	 * before the dispatch.
904 	 */
905 	ppgtt = req->ctx->ppgtt;
906 	if (ppgtt && req->engine->id != RCS)
907 		ppgtt->pd_dirty_rings |= intel_engine_flag(req->engine);
908 	return 0;
909 }
910 
911 static int
912 gen6_ring_sync_to(struct drm_i915_gem_request *req,
913 		  struct drm_i915_gem_request *signal)
914 {
915 	u32 dw1 = MI_SEMAPHORE_MBOX |
916 		  MI_SEMAPHORE_COMPARE |
917 		  MI_SEMAPHORE_REGISTER;
918 	u32 wait_mbox = signal->engine->semaphore.mbox.wait[req->engine->hw_id];
919 	u32 *cs;
920 
921 	WARN_ON(wait_mbox == MI_SEMAPHORE_SYNC_INVALID);
922 
923 	cs = intel_ring_begin(req, 4);
924 	if (IS_ERR(cs))
925 		return PTR_ERR(cs);
926 
927 	*cs++ = dw1 | wait_mbox;
928 	/* Throughout all of the GEM code, seqno passed implies our current
929 	 * seqno is >= the last seqno executed. However for hardware the
930 	 * comparison is strictly greater than.
931 	 */
932 	*cs++ = signal->global_seqno - 1;
933 	*cs++ = 0;
934 	*cs++ = MI_NOOP;
935 	intel_ring_advance(req, cs);
936 
937 	return 0;
938 }
939 
940 static void
941 gen5_seqno_barrier(struct intel_engine_cs *engine)
942 {
943 	/* MI_STORE are internally buffered by the GPU and not flushed
944 	 * either by MI_FLUSH or SyncFlush or any other combination of
945 	 * MI commands.
946 	 *
947 	 * "Only the submission of the store operation is guaranteed.
948 	 * The write result will be complete (coherent) some time later
949 	 * (this is practically a finite period but there is no guaranteed
950 	 * latency)."
951 	 *
952 	 * Empirically, we observe that we need a delay of at least 75us to
953 	 * be sure that the seqno write is visible by the CPU.
954 	 */
955 	usleep_range(125, 250);
956 }
957 
958 static void
959 gen6_seqno_barrier(struct intel_engine_cs *engine)
960 {
961 	struct drm_i915_private *dev_priv = engine->i915;
962 
963 	/* Workaround to force correct ordering between irq and seqno writes on
964 	 * ivb (and maybe also on snb) by reading from a CS register (like
965 	 * ACTHD) before reading the status page.
966 	 *
967 	 * Note that this effectively stalls the read by the time it takes to
968 	 * do a memory transaction, which more or less ensures that the write
969 	 * from the GPU has sufficient time to invalidate the CPU cacheline.
970 	 * Alternatively we could delay the interrupt from the CS ring to give
971 	 * the write time to land, but that would incur a delay after every
972 	 * batch i.e. much more frequent than a delay when waiting for the
973 	 * interrupt (with the same net latency).
974 	 *
975 	 * Also note that to prevent whole machine hangs on gen7, we have to
976 	 * take the spinlock to guard against concurrent cacheline access.
977 	 */
978 	spin_lock_irq(&dev_priv->uncore.lock);
979 	POSTING_READ_FW(RING_ACTHD(engine->mmio_base));
980 	spin_unlock_irq(&dev_priv->uncore.lock);
981 }
982 
983 static void
984 gen5_irq_enable(struct intel_engine_cs *engine)
985 {
986 	gen5_enable_gt_irq(engine->i915, engine->irq_enable_mask);
987 }
988 
989 static void
990 gen5_irq_disable(struct intel_engine_cs *engine)
991 {
992 	gen5_disable_gt_irq(engine->i915, engine->irq_enable_mask);
993 }
994 
995 static void
996 i9xx_irq_enable(struct intel_engine_cs *engine)
997 {
998 	struct drm_i915_private *dev_priv = engine->i915;
999 
1000 	dev_priv->irq_mask &= ~engine->irq_enable_mask;
1001 	I915_WRITE(IMR, dev_priv->irq_mask);
1002 	POSTING_READ_FW(RING_IMR(engine->mmio_base));
1003 }
1004 
1005 static void
1006 i9xx_irq_disable(struct intel_engine_cs *engine)
1007 {
1008 	struct drm_i915_private *dev_priv = engine->i915;
1009 
1010 	dev_priv->irq_mask |= engine->irq_enable_mask;
1011 	I915_WRITE(IMR, dev_priv->irq_mask);
1012 }
1013 
1014 static void
1015 i8xx_irq_enable(struct intel_engine_cs *engine)
1016 {
1017 	struct drm_i915_private *dev_priv = engine->i915;
1018 
1019 	dev_priv->irq_mask &= ~engine->irq_enable_mask;
1020 	I915_WRITE16(IMR, dev_priv->irq_mask);
1021 	POSTING_READ16(RING_IMR(engine->mmio_base));
1022 }
1023 
1024 static void
1025 i8xx_irq_disable(struct intel_engine_cs *engine)
1026 {
1027 	struct drm_i915_private *dev_priv = engine->i915;
1028 
1029 	dev_priv->irq_mask |= engine->irq_enable_mask;
1030 	I915_WRITE16(IMR, dev_priv->irq_mask);
1031 }
1032 
1033 static int
1034 bsd_ring_flush(struct drm_i915_gem_request *req, u32 mode)
1035 {
1036 	u32 *cs;
1037 
1038 	cs = intel_ring_begin(req, 2);
1039 	if (IS_ERR(cs))
1040 		return PTR_ERR(cs);
1041 
1042 	*cs++ = MI_FLUSH;
1043 	*cs++ = MI_NOOP;
1044 	intel_ring_advance(req, cs);
1045 	return 0;
1046 }
1047 
1048 static void
1049 gen6_irq_enable(struct intel_engine_cs *engine)
1050 {
1051 	struct drm_i915_private *dev_priv = engine->i915;
1052 
1053 	I915_WRITE_IMR(engine,
1054 		       ~(engine->irq_enable_mask |
1055 			 engine->irq_keep_mask));
1056 	gen5_enable_gt_irq(dev_priv, engine->irq_enable_mask);
1057 }
1058 
1059 static void
1060 gen6_irq_disable(struct intel_engine_cs *engine)
1061 {
1062 	struct drm_i915_private *dev_priv = engine->i915;
1063 
1064 	I915_WRITE_IMR(engine, ~engine->irq_keep_mask);
1065 	gen5_disable_gt_irq(dev_priv, engine->irq_enable_mask);
1066 }
1067 
1068 static void
1069 hsw_vebox_irq_enable(struct intel_engine_cs *engine)
1070 {
1071 	struct drm_i915_private *dev_priv = engine->i915;
1072 
1073 	I915_WRITE_IMR(engine, ~engine->irq_enable_mask);
1074 	gen6_unmask_pm_irq(dev_priv, engine->irq_enable_mask);
1075 }
1076 
1077 static void
1078 hsw_vebox_irq_disable(struct intel_engine_cs *engine)
1079 {
1080 	struct drm_i915_private *dev_priv = engine->i915;
1081 
1082 	I915_WRITE_IMR(engine, ~0);
1083 	gen6_mask_pm_irq(dev_priv, engine->irq_enable_mask);
1084 }
1085 
1086 static void
1087 gen8_irq_enable(struct intel_engine_cs *engine)
1088 {
1089 	struct drm_i915_private *dev_priv = engine->i915;
1090 
1091 	I915_WRITE_IMR(engine,
1092 		       ~(engine->irq_enable_mask |
1093 			 engine->irq_keep_mask));
1094 	POSTING_READ_FW(RING_IMR(engine->mmio_base));
1095 }
1096 
1097 static void
1098 gen8_irq_disable(struct intel_engine_cs *engine)
1099 {
1100 	struct drm_i915_private *dev_priv = engine->i915;
1101 
1102 	I915_WRITE_IMR(engine, ~engine->irq_keep_mask);
1103 }
1104 
1105 static int
1106 i965_emit_bb_start(struct drm_i915_gem_request *req,
1107 		   u64 offset, u32 length,
1108 		   unsigned int dispatch_flags)
1109 {
1110 	u32 *cs;
1111 
1112 	cs = intel_ring_begin(req, 2);
1113 	if (IS_ERR(cs))
1114 		return PTR_ERR(cs);
1115 
1116 	*cs++ = MI_BATCH_BUFFER_START | MI_BATCH_GTT | (dispatch_flags &
1117 		I915_DISPATCH_SECURE ? 0 : MI_BATCH_NON_SECURE_I965);
1118 	*cs++ = offset;
1119 	intel_ring_advance(req, cs);
1120 
1121 	return 0;
1122 }
1123 
1124 /* Just userspace ABI convention to limit the wa batch bo to a resonable size */
1125 #define I830_BATCH_LIMIT (256*1024)
1126 #define I830_TLB_ENTRIES (2)
1127 #define I830_WA_SIZE max(I830_TLB_ENTRIES*4096, I830_BATCH_LIMIT)
1128 static int
1129 i830_emit_bb_start(struct drm_i915_gem_request *req,
1130 		   u64 offset, u32 len,
1131 		   unsigned int dispatch_flags)
1132 {
1133 	u32 *cs, cs_offset = i915_ggtt_offset(req->engine->scratch);
1134 
1135 	cs = intel_ring_begin(req, 6);
1136 	if (IS_ERR(cs))
1137 		return PTR_ERR(cs);
1138 
1139 	/* Evict the invalid PTE TLBs */
1140 	*cs++ = COLOR_BLT_CMD | BLT_WRITE_RGBA;
1141 	*cs++ = BLT_DEPTH_32 | BLT_ROP_COLOR_COPY | 4096;
1142 	*cs++ = I830_TLB_ENTRIES << 16 | 4; /* load each page */
1143 	*cs++ = cs_offset;
1144 	*cs++ = 0xdeadbeef;
1145 	*cs++ = MI_NOOP;
1146 	intel_ring_advance(req, cs);
1147 
1148 	if ((dispatch_flags & I915_DISPATCH_PINNED) == 0) {
1149 		if (len > I830_BATCH_LIMIT)
1150 			return -ENOSPC;
1151 
1152 		cs = intel_ring_begin(req, 6 + 2);
1153 		if (IS_ERR(cs))
1154 			return PTR_ERR(cs);
1155 
1156 		/* Blit the batch (which has now all relocs applied) to the
1157 		 * stable batch scratch bo area (so that the CS never
1158 		 * stumbles over its tlb invalidation bug) ...
1159 		 */
1160 		*cs++ = SRC_COPY_BLT_CMD | BLT_WRITE_RGBA;
1161 		*cs++ = BLT_DEPTH_32 | BLT_ROP_SRC_COPY | 4096;
1162 		*cs++ = DIV_ROUND_UP(len, 4096) << 16 | 4096;
1163 		*cs++ = cs_offset;
1164 		*cs++ = 4096;
1165 		*cs++ = offset;
1166 
1167 		*cs++ = MI_FLUSH;
1168 		*cs++ = MI_NOOP;
1169 		intel_ring_advance(req, cs);
1170 
1171 		/* ... and execute it. */
1172 		offset = cs_offset;
1173 	}
1174 
1175 	cs = intel_ring_begin(req, 2);
1176 	if (IS_ERR(cs))
1177 		return PTR_ERR(cs);
1178 
1179 	*cs++ = MI_BATCH_BUFFER_START | MI_BATCH_GTT;
1180 	*cs++ = offset | (dispatch_flags & I915_DISPATCH_SECURE ? 0 :
1181 		MI_BATCH_NON_SECURE);
1182 	intel_ring_advance(req, cs);
1183 
1184 	return 0;
1185 }
1186 
1187 static int
1188 i915_emit_bb_start(struct drm_i915_gem_request *req,
1189 		   u64 offset, u32 len,
1190 		   unsigned int dispatch_flags)
1191 {
1192 	u32 *cs;
1193 
1194 	cs = intel_ring_begin(req, 2);
1195 	if (IS_ERR(cs))
1196 		return PTR_ERR(cs);
1197 
1198 	*cs++ = MI_BATCH_BUFFER_START | MI_BATCH_GTT;
1199 	*cs++ = offset | (dispatch_flags & I915_DISPATCH_SECURE ? 0 :
1200 		MI_BATCH_NON_SECURE);
1201 	intel_ring_advance(req, cs);
1202 
1203 	return 0;
1204 }
1205 
1206 
1207 
1208 int intel_ring_pin(struct intel_ring *ring,
1209 		   struct drm_i915_private *i915,
1210 		   unsigned int offset_bias)
1211 {
1212 	enum i915_map_type map = HAS_LLC(i915) ? I915_MAP_WB : I915_MAP_WC;
1213 	struct i915_vma *vma = ring->vma;
1214 	unsigned int flags;
1215 	void *addr;
1216 	int ret;
1217 
1218 	GEM_BUG_ON(ring->vaddr);
1219 
1220 
1221 	flags = PIN_GLOBAL;
1222 	if (offset_bias)
1223 		flags |= PIN_OFFSET_BIAS | offset_bias;
1224 	if (vma->obj->stolen)
1225 		flags |= PIN_MAPPABLE;
1226 
1227 	if (!(vma->flags & I915_VMA_GLOBAL_BIND)) {
1228 		if (flags & PIN_MAPPABLE || map == I915_MAP_WC)
1229 			ret = i915_gem_object_set_to_gtt_domain(vma->obj, true);
1230 		else
1231 			ret = i915_gem_object_set_to_cpu_domain(vma->obj, true);
1232 		if (unlikely(ret))
1233 			return ret;
1234 	}
1235 
1236 	ret = i915_vma_pin(vma, 0, PAGE_SIZE, flags);
1237 	if (unlikely(ret))
1238 		return ret;
1239 
1240 	if (i915_vma_is_map_and_fenceable(vma))
1241 		addr = (void __force *)i915_vma_pin_iomap(vma);
1242 	else
1243 		addr = i915_gem_object_pin_map(vma->obj, map);
1244 	if (IS_ERR(addr))
1245 		goto err;
1246 
1247 	vma->obj->pin_global++;
1248 
1249 	ring->vaddr = addr;
1250 	return 0;
1251 
1252 err:
1253 	i915_vma_unpin(vma);
1254 	return PTR_ERR(addr);
1255 }
1256 
1257 void intel_ring_reset(struct intel_ring *ring, u32 tail)
1258 {
1259 	GEM_BUG_ON(!list_empty(&ring->request_list));
1260 	ring->tail = tail;
1261 	ring->head = tail;
1262 	ring->emit = tail;
1263 	intel_ring_update_space(ring);
1264 }
1265 
1266 void intel_ring_unpin(struct intel_ring *ring)
1267 {
1268 	GEM_BUG_ON(!ring->vma);
1269 	GEM_BUG_ON(!ring->vaddr);
1270 
1271 	/* Discard any unused bytes beyond that submitted to hw. */
1272 	intel_ring_reset(ring, ring->tail);
1273 
1274 	if (i915_vma_is_map_and_fenceable(ring->vma))
1275 		i915_vma_unpin_iomap(ring->vma);
1276 	else
1277 		i915_gem_object_unpin_map(ring->vma->obj);
1278 	ring->vaddr = NULL;
1279 
1280 	ring->vma->obj->pin_global--;
1281 	i915_vma_unpin(ring->vma);
1282 }
1283 
1284 static struct i915_vma *
1285 intel_ring_create_vma(struct drm_i915_private *dev_priv, int size)
1286 {
1287 	struct drm_i915_gem_object *obj;
1288 	struct i915_vma *vma;
1289 
1290 	obj = i915_gem_object_create_stolen(dev_priv, size);
1291 	if (!obj)
1292 		obj = i915_gem_object_create_internal(dev_priv, size);
1293 	if (IS_ERR(obj))
1294 		return ERR_CAST(obj);
1295 
1296 	/* mark ring buffers as read-only from GPU side by default */
1297 	obj->gt_ro = 1;
1298 
1299 	vma = i915_vma_instance(obj, &dev_priv->ggtt.base, NULL);
1300 	if (IS_ERR(vma))
1301 		goto err;
1302 
1303 	return vma;
1304 
1305 err:
1306 	i915_gem_object_put(obj);
1307 	return vma;
1308 }
1309 
1310 struct intel_ring *
1311 intel_engine_create_ring(struct intel_engine_cs *engine, int size)
1312 {
1313 	struct intel_ring *ring;
1314 	struct i915_vma *vma;
1315 
1316 	GEM_BUG_ON(!is_power_of_2(size));
1317 	GEM_BUG_ON(RING_CTL_SIZE(size) & ~RING_NR_PAGES);
1318 
1319 	ring = kzalloc(sizeof(*ring), GFP_KERNEL);
1320 	if (!ring)
1321 		return ERR_PTR(-ENOMEM);
1322 
1323 	INIT_LIST_HEAD(&ring->request_list);
1324 
1325 	ring->size = size;
1326 	/* Workaround an erratum on the i830 which causes a hang if
1327 	 * the TAIL pointer points to within the last 2 cachelines
1328 	 * of the buffer.
1329 	 */
1330 	ring->effective_size = size;
1331 	if (IS_I830(engine->i915) || IS_I845G(engine->i915))
1332 		ring->effective_size -= 2 * CACHELINE_BYTES;
1333 
1334 	intel_ring_update_space(ring);
1335 
1336 	vma = intel_ring_create_vma(engine->i915, size);
1337 	if (IS_ERR(vma)) {
1338 		kfree(ring);
1339 		return ERR_CAST(vma);
1340 	}
1341 	ring->vma = vma;
1342 
1343 	return ring;
1344 }
1345 
1346 void
1347 intel_ring_free(struct intel_ring *ring)
1348 {
1349 	struct drm_i915_gem_object *obj = ring->vma->obj;
1350 
1351 	i915_vma_close(ring->vma);
1352 	__i915_gem_object_release_unless_active(obj);
1353 
1354 	kfree(ring);
1355 }
1356 
1357 static int context_pin(struct i915_gem_context *ctx)
1358 {
1359 	struct i915_vma *vma = ctx->engine[RCS].state;
1360 	int ret;
1361 
1362 	/* Clear this page out of any CPU caches for coherent swap-in/out.
1363 	 * We only want to do this on the first bind so that we do not stall
1364 	 * on an active context (which by nature is already on the GPU).
1365 	 */
1366 	if (!(vma->flags & I915_VMA_GLOBAL_BIND)) {
1367 		ret = i915_gem_object_set_to_gtt_domain(vma->obj, false);
1368 		if (ret)
1369 			return ret;
1370 	}
1371 
1372 	return i915_vma_pin(vma, 0, I915_GTT_MIN_ALIGNMENT,
1373 			    PIN_GLOBAL | PIN_HIGH);
1374 }
1375 
1376 static struct i915_vma *
1377 alloc_context_vma(struct intel_engine_cs *engine)
1378 {
1379 	struct drm_i915_private *i915 = engine->i915;
1380 	struct drm_i915_gem_object *obj;
1381 	struct i915_vma *vma;
1382 
1383 	obj = i915_gem_object_create(i915, engine->context_size);
1384 	if (IS_ERR(obj))
1385 		return ERR_CAST(obj);
1386 
1387 	/*
1388 	 * Try to make the context utilize L3 as well as LLC.
1389 	 *
1390 	 * On VLV we don't have L3 controls in the PTEs so we
1391 	 * shouldn't touch the cache level, especially as that
1392 	 * would make the object snooped which might have a
1393 	 * negative performance impact.
1394 	 *
1395 	 * Snooping is required on non-llc platforms in execlist
1396 	 * mode, but since all GGTT accesses use PAT entry 0 we
1397 	 * get snooping anyway regardless of cache_level.
1398 	 *
1399 	 * This is only applicable for Ivy Bridge devices since
1400 	 * later platforms don't have L3 control bits in the PTE.
1401 	 */
1402 	if (IS_IVYBRIDGE(i915)) {
1403 		/* Ignore any error, regard it as a simple optimisation */
1404 		i915_gem_object_set_cache_level(obj, I915_CACHE_L3_LLC);
1405 	}
1406 
1407 	vma = i915_vma_instance(obj, &i915->ggtt.base, NULL);
1408 	if (IS_ERR(vma))
1409 		i915_gem_object_put(obj);
1410 
1411 	return vma;
1412 }
1413 
1414 static struct intel_ring *
1415 intel_ring_context_pin(struct intel_engine_cs *engine,
1416 		       struct i915_gem_context *ctx)
1417 {
1418 	struct intel_context *ce = &ctx->engine[engine->id];
1419 	int ret;
1420 
1421 	lockdep_assert_held(&ctx->i915->drm.struct_mutex);
1422 
1423 	if (likely(ce->pin_count++))
1424 		goto out;
1425 	GEM_BUG_ON(!ce->pin_count); /* no overflow please! */
1426 
1427 	if (!ce->state && engine->context_size) {
1428 		struct i915_vma *vma;
1429 
1430 		vma = alloc_context_vma(engine);
1431 		if (IS_ERR(vma)) {
1432 			ret = PTR_ERR(vma);
1433 			goto err;
1434 		}
1435 
1436 		ce->state = vma;
1437 	}
1438 
1439 	if (ce->state) {
1440 		ret = context_pin(ctx);
1441 		if (ret)
1442 			goto err;
1443 
1444 		ce->state->obj->mm.dirty = true;
1445 		ce->state->obj->pin_global++;
1446 	}
1447 
1448 	/* The kernel context is only used as a placeholder for flushing the
1449 	 * active context. It is never used for submitting user rendering and
1450 	 * as such never requires the golden render context, and so we can skip
1451 	 * emitting it when we switch to the kernel context. This is required
1452 	 * as during eviction we cannot allocate and pin the renderstate in
1453 	 * order to initialise the context.
1454 	 */
1455 	if (i915_gem_context_is_kernel(ctx))
1456 		ce->initialised = true;
1457 
1458 	i915_gem_context_get(ctx);
1459 
1460 out:
1461 	/* One ringbuffer to rule them all */
1462 	return engine->buffer;
1463 
1464 err:
1465 	ce->pin_count = 0;
1466 	return ERR_PTR(ret);
1467 }
1468 
1469 static void intel_ring_context_unpin(struct intel_engine_cs *engine,
1470 				     struct i915_gem_context *ctx)
1471 {
1472 	struct intel_context *ce = &ctx->engine[engine->id];
1473 
1474 	lockdep_assert_held(&ctx->i915->drm.struct_mutex);
1475 	GEM_BUG_ON(ce->pin_count == 0);
1476 
1477 	if (--ce->pin_count)
1478 		return;
1479 
1480 	if (ce->state) {
1481 		ce->state->obj->pin_global--;
1482 		i915_vma_unpin(ce->state);
1483 	}
1484 
1485 	i915_gem_context_put(ctx);
1486 }
1487 
1488 static int intel_init_ring_buffer(struct intel_engine_cs *engine)
1489 {
1490 	struct intel_ring *ring;
1491 	int err;
1492 
1493 	intel_engine_setup_common(engine);
1494 
1495 	err = intel_engine_init_common(engine);
1496 	if (err)
1497 		goto err;
1498 
1499 	ring = intel_engine_create_ring(engine, 32 * PAGE_SIZE);
1500 	if (IS_ERR(ring)) {
1501 		err = PTR_ERR(ring);
1502 		goto err;
1503 	}
1504 
1505 	/* Ring wraparound at offset 0 sometimes hangs. No idea why. */
1506 	err = intel_ring_pin(ring, engine->i915, I915_GTT_PAGE_SIZE);
1507 	if (err)
1508 		goto err_ring;
1509 
1510 	GEM_BUG_ON(engine->buffer);
1511 	engine->buffer = ring;
1512 
1513 	return 0;
1514 
1515 err_ring:
1516 	intel_ring_free(ring);
1517 err:
1518 	intel_engine_cleanup_common(engine);
1519 	return err;
1520 }
1521 
1522 void intel_engine_cleanup(struct intel_engine_cs *engine)
1523 {
1524 	struct drm_i915_private *dev_priv = engine->i915;
1525 
1526 	WARN_ON(INTEL_GEN(dev_priv) > 2 &&
1527 		(I915_READ_MODE(engine) & MODE_IDLE) == 0);
1528 
1529 	intel_ring_unpin(engine->buffer);
1530 	intel_ring_free(engine->buffer);
1531 
1532 	if (engine->cleanup)
1533 		engine->cleanup(engine);
1534 
1535 	intel_engine_cleanup_common(engine);
1536 
1537 	dev_priv->engine[engine->id] = NULL;
1538 	kfree(engine);
1539 }
1540 
1541 void intel_legacy_submission_resume(struct drm_i915_private *dev_priv)
1542 {
1543 	struct intel_engine_cs *engine;
1544 	enum intel_engine_id id;
1545 
1546 	/* Restart from the beginning of the rings for convenience */
1547 	for_each_engine(engine, dev_priv, id)
1548 		intel_ring_reset(engine->buffer, 0);
1549 }
1550 
1551 static int ring_request_alloc(struct drm_i915_gem_request *request)
1552 {
1553 	u32 *cs;
1554 
1555 	GEM_BUG_ON(!request->ctx->engine[request->engine->id].pin_count);
1556 
1557 	/* Flush enough space to reduce the likelihood of waiting after
1558 	 * we start building the request - in which case we will just
1559 	 * have to repeat work.
1560 	 */
1561 	request->reserved_space += LEGACY_REQUEST_SIZE;
1562 
1563 	cs = intel_ring_begin(request, 0);
1564 	if (IS_ERR(cs))
1565 		return PTR_ERR(cs);
1566 
1567 	request->reserved_space -= LEGACY_REQUEST_SIZE;
1568 	return 0;
1569 }
1570 
1571 static noinline int wait_for_space(struct drm_i915_gem_request *req,
1572 				   unsigned int bytes)
1573 {
1574 	struct intel_ring *ring = req->ring;
1575 	struct drm_i915_gem_request *target;
1576 	long timeout;
1577 
1578 	lockdep_assert_held(&req->i915->drm.struct_mutex);
1579 
1580 	if (intel_ring_update_space(ring) >= bytes)
1581 		return 0;
1582 
1583 	/*
1584 	 * Space is reserved in the ringbuffer for finalising the request,
1585 	 * as that cannot be allowed to fail. During request finalisation,
1586 	 * reserved_space is set to 0 to stop the overallocation and the
1587 	 * assumption is that then we never need to wait (which has the
1588 	 * risk of failing with EINTR).
1589 	 *
1590 	 * See also i915_gem_request_alloc() and i915_add_request().
1591 	 */
1592 	GEM_BUG_ON(!req->reserved_space);
1593 
1594 	list_for_each_entry(target, &ring->request_list, ring_link) {
1595 		/* Would completion of this request free enough space? */
1596 		if (bytes <= __intel_ring_space(target->postfix,
1597 						ring->emit, ring->size))
1598 			break;
1599 	}
1600 
1601 	if (WARN_ON(&target->ring_link == &ring->request_list))
1602 		return -ENOSPC;
1603 
1604 	timeout = i915_wait_request(target,
1605 				    I915_WAIT_INTERRUPTIBLE | I915_WAIT_LOCKED,
1606 				    MAX_SCHEDULE_TIMEOUT);
1607 	if (timeout < 0)
1608 		return timeout;
1609 
1610 	i915_gem_request_retire_upto(target);
1611 
1612 	intel_ring_update_space(ring);
1613 	GEM_BUG_ON(ring->space < bytes);
1614 	return 0;
1615 }
1616 
1617 u32 *intel_ring_begin(struct drm_i915_gem_request *req,
1618 		      unsigned int num_dwords)
1619 {
1620 	struct intel_ring *ring = req->ring;
1621 	const unsigned int remain_usable = ring->effective_size - ring->emit;
1622 	const unsigned int bytes = num_dwords * sizeof(u32);
1623 	unsigned int need_wrap = 0;
1624 	unsigned int total_bytes;
1625 	u32 *cs;
1626 
1627 	/* Packets must be qword aligned. */
1628 	GEM_BUG_ON(num_dwords & 1);
1629 
1630 	total_bytes = bytes + req->reserved_space;
1631 	GEM_BUG_ON(total_bytes > ring->effective_size);
1632 
1633 	if (unlikely(total_bytes > remain_usable)) {
1634 		const int remain_actual = ring->size - ring->emit;
1635 
1636 		if (bytes > remain_usable) {
1637 			/*
1638 			 * Not enough space for the basic request. So need to
1639 			 * flush out the remainder and then wait for
1640 			 * base + reserved.
1641 			 */
1642 			total_bytes += remain_actual;
1643 			need_wrap = remain_actual | 1;
1644 		} else  {
1645 			/*
1646 			 * The base request will fit but the reserved space
1647 			 * falls off the end. So we don't need an immediate
1648 			 * wrap and only need to effectively wait for the
1649 			 * reserved size from the start of ringbuffer.
1650 			 */
1651 			total_bytes = req->reserved_space + remain_actual;
1652 		}
1653 	}
1654 
1655 	if (unlikely(total_bytes > ring->space)) {
1656 		int ret = wait_for_space(req, total_bytes);
1657 		if (unlikely(ret))
1658 			return ERR_PTR(ret);
1659 	}
1660 
1661 	if (unlikely(need_wrap)) {
1662 		need_wrap &= ~1;
1663 		GEM_BUG_ON(need_wrap > ring->space);
1664 		GEM_BUG_ON(ring->emit + need_wrap > ring->size);
1665 
1666 		/* Fill the tail with MI_NOOP */
1667 		memset(ring->vaddr + ring->emit, 0, need_wrap);
1668 		ring->emit = 0;
1669 		ring->space -= need_wrap;
1670 	}
1671 
1672 	GEM_BUG_ON(ring->emit > ring->size - bytes);
1673 	GEM_BUG_ON(ring->space < bytes);
1674 	cs = ring->vaddr + ring->emit;
1675 	GEM_DEBUG_EXEC(memset(cs, POISON_INUSE, bytes));
1676 	ring->emit += bytes;
1677 	ring->space -= bytes;
1678 
1679 	return cs;
1680 }
1681 
1682 /* Align the ring tail to a cacheline boundary */
1683 int intel_ring_cacheline_align(struct drm_i915_gem_request *req)
1684 {
1685 	int num_dwords =
1686 		(req->ring->emit & (CACHELINE_BYTES - 1)) / sizeof(uint32_t);
1687 	u32 *cs;
1688 
1689 	if (num_dwords == 0)
1690 		return 0;
1691 
1692 	num_dwords = CACHELINE_BYTES / sizeof(uint32_t) - num_dwords;
1693 	cs = intel_ring_begin(req, num_dwords);
1694 	if (IS_ERR(cs))
1695 		return PTR_ERR(cs);
1696 
1697 	while (num_dwords--)
1698 		*cs++ = MI_NOOP;
1699 
1700 	intel_ring_advance(req, cs);
1701 
1702 	return 0;
1703 }
1704 
1705 static void gen6_bsd_submit_request(struct drm_i915_gem_request *request)
1706 {
1707 	struct drm_i915_private *dev_priv = request->i915;
1708 
1709 	intel_uncore_forcewake_get(dev_priv, FORCEWAKE_ALL);
1710 
1711        /* Every tail move must follow the sequence below */
1712 
1713 	/* Disable notification that the ring is IDLE. The GT
1714 	 * will then assume that it is busy and bring it out of rc6.
1715 	 */
1716 	I915_WRITE_FW(GEN6_BSD_SLEEP_PSMI_CONTROL,
1717 		      _MASKED_BIT_ENABLE(GEN6_BSD_SLEEP_MSG_DISABLE));
1718 
1719 	/* Clear the context id. Here be magic! */
1720 	I915_WRITE64_FW(GEN6_BSD_RNCID, 0x0);
1721 
1722 	/* Wait for the ring not to be idle, i.e. for it to wake up. */
1723 	if (__intel_wait_for_register_fw(dev_priv,
1724 					 GEN6_BSD_SLEEP_PSMI_CONTROL,
1725 					 GEN6_BSD_SLEEP_INDICATOR,
1726 					 0,
1727 					 1000, 0, NULL))
1728 		DRM_ERROR("timed out waiting for the BSD ring to wake up\n");
1729 
1730 	/* Now that the ring is fully powered up, update the tail */
1731 	i9xx_submit_request(request);
1732 
1733 	/* Let the ring send IDLE messages to the GT again,
1734 	 * and so let it sleep to conserve power when idle.
1735 	 */
1736 	I915_WRITE_FW(GEN6_BSD_SLEEP_PSMI_CONTROL,
1737 		      _MASKED_BIT_DISABLE(GEN6_BSD_SLEEP_MSG_DISABLE));
1738 
1739 	intel_uncore_forcewake_put(dev_priv, FORCEWAKE_ALL);
1740 }
1741 
1742 static int gen6_bsd_ring_flush(struct drm_i915_gem_request *req, u32 mode)
1743 {
1744 	u32 cmd, *cs;
1745 
1746 	cs = intel_ring_begin(req, 4);
1747 	if (IS_ERR(cs))
1748 		return PTR_ERR(cs);
1749 
1750 	cmd = MI_FLUSH_DW;
1751 	if (INTEL_GEN(req->i915) >= 8)
1752 		cmd += 1;
1753 
1754 	/* We always require a command barrier so that subsequent
1755 	 * commands, such as breadcrumb interrupts, are strictly ordered
1756 	 * wrt the contents of the write cache being flushed to memory
1757 	 * (and thus being coherent from the CPU).
1758 	 */
1759 	cmd |= MI_FLUSH_DW_STORE_INDEX | MI_FLUSH_DW_OP_STOREDW;
1760 
1761 	/*
1762 	 * Bspec vol 1c.5 - video engine command streamer:
1763 	 * "If ENABLED, all TLBs will be invalidated once the flush
1764 	 * operation is complete. This bit is only valid when the
1765 	 * Post-Sync Operation field is a value of 1h or 3h."
1766 	 */
1767 	if (mode & EMIT_INVALIDATE)
1768 		cmd |= MI_INVALIDATE_TLB | MI_INVALIDATE_BSD;
1769 
1770 	*cs++ = cmd;
1771 	*cs++ = I915_GEM_HWS_SCRATCH_ADDR | MI_FLUSH_DW_USE_GTT;
1772 	if (INTEL_GEN(req->i915) >= 8) {
1773 		*cs++ = 0; /* upper addr */
1774 		*cs++ = 0; /* value */
1775 	} else  {
1776 		*cs++ = 0;
1777 		*cs++ = MI_NOOP;
1778 	}
1779 	intel_ring_advance(req, cs);
1780 	return 0;
1781 }
1782 
1783 static int
1784 gen8_emit_bb_start(struct drm_i915_gem_request *req,
1785 		   u64 offset, u32 len,
1786 		   unsigned int dispatch_flags)
1787 {
1788 	bool ppgtt = USES_PPGTT(req->i915) &&
1789 			!(dispatch_flags & I915_DISPATCH_SECURE);
1790 	u32 *cs;
1791 
1792 	cs = intel_ring_begin(req, 4);
1793 	if (IS_ERR(cs))
1794 		return PTR_ERR(cs);
1795 
1796 	/* FIXME(BDW): Address space and security selectors. */
1797 	*cs++ = MI_BATCH_BUFFER_START_GEN8 | (ppgtt << 8) | (dispatch_flags &
1798 		I915_DISPATCH_RS ? MI_BATCH_RESOURCE_STREAMER : 0);
1799 	*cs++ = lower_32_bits(offset);
1800 	*cs++ = upper_32_bits(offset);
1801 	*cs++ = MI_NOOP;
1802 	intel_ring_advance(req, cs);
1803 
1804 	return 0;
1805 }
1806 
1807 static int
1808 hsw_emit_bb_start(struct drm_i915_gem_request *req,
1809 		  u64 offset, u32 len,
1810 		  unsigned int dispatch_flags)
1811 {
1812 	u32 *cs;
1813 
1814 	cs = intel_ring_begin(req, 2);
1815 	if (IS_ERR(cs))
1816 		return PTR_ERR(cs);
1817 
1818 	*cs++ = MI_BATCH_BUFFER_START | (dispatch_flags & I915_DISPATCH_SECURE ?
1819 		0 : MI_BATCH_PPGTT_HSW | MI_BATCH_NON_SECURE_HSW) |
1820 		(dispatch_flags & I915_DISPATCH_RS ?
1821 		MI_BATCH_RESOURCE_STREAMER : 0);
1822 	/* bit0-7 is the length on GEN6+ */
1823 	*cs++ = offset;
1824 	intel_ring_advance(req, cs);
1825 
1826 	return 0;
1827 }
1828 
1829 static int
1830 gen6_emit_bb_start(struct drm_i915_gem_request *req,
1831 		   u64 offset, u32 len,
1832 		   unsigned int dispatch_flags)
1833 {
1834 	u32 *cs;
1835 
1836 	cs = intel_ring_begin(req, 2);
1837 	if (IS_ERR(cs))
1838 		return PTR_ERR(cs);
1839 
1840 	*cs++ = MI_BATCH_BUFFER_START | (dispatch_flags & I915_DISPATCH_SECURE ?
1841 		0 : MI_BATCH_NON_SECURE_I965);
1842 	/* bit0-7 is the length on GEN6+ */
1843 	*cs++ = offset;
1844 	intel_ring_advance(req, cs);
1845 
1846 	return 0;
1847 }
1848 
1849 /* Blitter support (SandyBridge+) */
1850 
1851 static int gen6_ring_flush(struct drm_i915_gem_request *req, u32 mode)
1852 {
1853 	u32 cmd, *cs;
1854 
1855 	cs = intel_ring_begin(req, 4);
1856 	if (IS_ERR(cs))
1857 		return PTR_ERR(cs);
1858 
1859 	cmd = MI_FLUSH_DW;
1860 	if (INTEL_GEN(req->i915) >= 8)
1861 		cmd += 1;
1862 
1863 	/* We always require a command barrier so that subsequent
1864 	 * commands, such as breadcrumb interrupts, are strictly ordered
1865 	 * wrt the contents of the write cache being flushed to memory
1866 	 * (and thus being coherent from the CPU).
1867 	 */
1868 	cmd |= MI_FLUSH_DW_STORE_INDEX | MI_FLUSH_DW_OP_STOREDW;
1869 
1870 	/*
1871 	 * Bspec vol 1c.3 - blitter engine command streamer:
1872 	 * "If ENABLED, all TLBs will be invalidated once the flush
1873 	 * operation is complete. This bit is only valid when the
1874 	 * Post-Sync Operation field is a value of 1h or 3h."
1875 	 */
1876 	if (mode & EMIT_INVALIDATE)
1877 		cmd |= MI_INVALIDATE_TLB;
1878 	*cs++ = cmd;
1879 	*cs++ = I915_GEM_HWS_SCRATCH_ADDR | MI_FLUSH_DW_USE_GTT;
1880 	if (INTEL_GEN(req->i915) >= 8) {
1881 		*cs++ = 0; /* upper addr */
1882 		*cs++ = 0; /* value */
1883 	} else  {
1884 		*cs++ = 0;
1885 		*cs++ = MI_NOOP;
1886 	}
1887 	intel_ring_advance(req, cs);
1888 
1889 	return 0;
1890 }
1891 
1892 static void intel_ring_init_semaphores(struct drm_i915_private *dev_priv,
1893 				       struct intel_engine_cs *engine)
1894 {
1895 	struct drm_i915_gem_object *obj;
1896 	int ret, i;
1897 
1898 	if (!i915_modparams.semaphores)
1899 		return;
1900 
1901 	if (INTEL_GEN(dev_priv) >= 8 && !dev_priv->semaphore) {
1902 		struct i915_vma *vma;
1903 
1904 		obj = i915_gem_object_create(dev_priv, PAGE_SIZE);
1905 		if (IS_ERR(obj))
1906 			goto err;
1907 
1908 		vma = i915_vma_instance(obj, &dev_priv->ggtt.base, NULL);
1909 		if (IS_ERR(vma))
1910 			goto err_obj;
1911 
1912 		ret = i915_gem_object_set_to_gtt_domain(obj, false);
1913 		if (ret)
1914 			goto err_obj;
1915 
1916 		ret = i915_vma_pin(vma, 0, 0, PIN_GLOBAL | PIN_HIGH);
1917 		if (ret)
1918 			goto err_obj;
1919 
1920 		dev_priv->semaphore = vma;
1921 	}
1922 
1923 	if (INTEL_GEN(dev_priv) >= 8) {
1924 		u32 offset = i915_ggtt_offset(dev_priv->semaphore);
1925 
1926 		engine->semaphore.sync_to = gen8_ring_sync_to;
1927 		engine->semaphore.signal = gen8_xcs_signal;
1928 
1929 		for (i = 0; i < I915_NUM_ENGINES; i++) {
1930 			u32 ring_offset;
1931 
1932 			if (i != engine->id)
1933 				ring_offset = offset + GEN8_SEMAPHORE_OFFSET(engine->id, i);
1934 			else
1935 				ring_offset = MI_SEMAPHORE_SYNC_INVALID;
1936 
1937 			engine->semaphore.signal_ggtt[i] = ring_offset;
1938 		}
1939 	} else if (INTEL_GEN(dev_priv) >= 6) {
1940 		engine->semaphore.sync_to = gen6_ring_sync_to;
1941 		engine->semaphore.signal = gen6_signal;
1942 
1943 		/*
1944 		 * The current semaphore is only applied on pre-gen8
1945 		 * platform.  And there is no VCS2 ring on the pre-gen8
1946 		 * platform. So the semaphore between RCS and VCS2 is
1947 		 * initialized as INVALID.  Gen8 will initialize the
1948 		 * sema between VCS2 and RCS later.
1949 		 */
1950 		for (i = 0; i < GEN6_NUM_SEMAPHORES; i++) {
1951 			static const struct {
1952 				u32 wait_mbox;
1953 				i915_reg_t mbox_reg;
1954 			} sem_data[GEN6_NUM_SEMAPHORES][GEN6_NUM_SEMAPHORES] = {
1955 				[RCS_HW] = {
1956 					[VCS_HW] =  { .wait_mbox = MI_SEMAPHORE_SYNC_RV,  .mbox_reg = GEN6_VRSYNC },
1957 					[BCS_HW] =  { .wait_mbox = MI_SEMAPHORE_SYNC_RB,  .mbox_reg = GEN6_BRSYNC },
1958 					[VECS_HW] = { .wait_mbox = MI_SEMAPHORE_SYNC_RVE, .mbox_reg = GEN6_VERSYNC },
1959 				},
1960 				[VCS_HW] = {
1961 					[RCS_HW] =  { .wait_mbox = MI_SEMAPHORE_SYNC_VR,  .mbox_reg = GEN6_RVSYNC },
1962 					[BCS_HW] =  { .wait_mbox = MI_SEMAPHORE_SYNC_VB,  .mbox_reg = GEN6_BVSYNC },
1963 					[VECS_HW] = { .wait_mbox = MI_SEMAPHORE_SYNC_VVE, .mbox_reg = GEN6_VEVSYNC },
1964 				},
1965 				[BCS_HW] = {
1966 					[RCS_HW] =  { .wait_mbox = MI_SEMAPHORE_SYNC_BR,  .mbox_reg = GEN6_RBSYNC },
1967 					[VCS_HW] =  { .wait_mbox = MI_SEMAPHORE_SYNC_BV,  .mbox_reg = GEN6_VBSYNC },
1968 					[VECS_HW] = { .wait_mbox = MI_SEMAPHORE_SYNC_BVE, .mbox_reg = GEN6_VEBSYNC },
1969 				},
1970 				[VECS_HW] = {
1971 					[RCS_HW] =  { .wait_mbox = MI_SEMAPHORE_SYNC_VER, .mbox_reg = GEN6_RVESYNC },
1972 					[VCS_HW] =  { .wait_mbox = MI_SEMAPHORE_SYNC_VEV, .mbox_reg = GEN6_VVESYNC },
1973 					[BCS_HW] =  { .wait_mbox = MI_SEMAPHORE_SYNC_VEB, .mbox_reg = GEN6_BVESYNC },
1974 				},
1975 			};
1976 			u32 wait_mbox;
1977 			i915_reg_t mbox_reg;
1978 
1979 			if (i == engine->hw_id) {
1980 				wait_mbox = MI_SEMAPHORE_SYNC_INVALID;
1981 				mbox_reg = GEN6_NOSYNC;
1982 			} else {
1983 				wait_mbox = sem_data[engine->hw_id][i].wait_mbox;
1984 				mbox_reg = sem_data[engine->hw_id][i].mbox_reg;
1985 			}
1986 
1987 			engine->semaphore.mbox.wait[i] = wait_mbox;
1988 			engine->semaphore.mbox.signal[i] = mbox_reg;
1989 		}
1990 	}
1991 
1992 	return;
1993 
1994 err_obj:
1995 	i915_gem_object_put(obj);
1996 err:
1997 	DRM_DEBUG_DRIVER("Failed to allocate space for semaphores, disabling\n");
1998 	i915_modparams.semaphores = 0;
1999 }
2000 
2001 static void intel_ring_init_irq(struct drm_i915_private *dev_priv,
2002 				struct intel_engine_cs *engine)
2003 {
2004 	engine->irq_enable_mask = GT_RENDER_USER_INTERRUPT << engine->irq_shift;
2005 
2006 	if (INTEL_GEN(dev_priv) >= 8) {
2007 		engine->irq_enable = gen8_irq_enable;
2008 		engine->irq_disable = gen8_irq_disable;
2009 		engine->irq_seqno_barrier = gen6_seqno_barrier;
2010 	} else if (INTEL_GEN(dev_priv) >= 6) {
2011 		engine->irq_enable = gen6_irq_enable;
2012 		engine->irq_disable = gen6_irq_disable;
2013 		engine->irq_seqno_barrier = gen6_seqno_barrier;
2014 	} else if (INTEL_GEN(dev_priv) >= 5) {
2015 		engine->irq_enable = gen5_irq_enable;
2016 		engine->irq_disable = gen5_irq_disable;
2017 		engine->irq_seqno_barrier = gen5_seqno_barrier;
2018 	} else if (INTEL_GEN(dev_priv) >= 3) {
2019 		engine->irq_enable = i9xx_irq_enable;
2020 		engine->irq_disable = i9xx_irq_disable;
2021 	} else {
2022 		engine->irq_enable = i8xx_irq_enable;
2023 		engine->irq_disable = i8xx_irq_disable;
2024 	}
2025 }
2026 
2027 static void i9xx_set_default_submission(struct intel_engine_cs *engine)
2028 {
2029 	engine->submit_request = i9xx_submit_request;
2030 	engine->cancel_requests = cancel_requests;
2031 }
2032 
2033 static void gen6_bsd_set_default_submission(struct intel_engine_cs *engine)
2034 {
2035 	engine->submit_request = gen6_bsd_submit_request;
2036 	engine->cancel_requests = cancel_requests;
2037 }
2038 
2039 static void intel_ring_default_vfuncs(struct drm_i915_private *dev_priv,
2040 				      struct intel_engine_cs *engine)
2041 {
2042 	intel_ring_init_irq(dev_priv, engine);
2043 	intel_ring_init_semaphores(dev_priv, engine);
2044 
2045 	engine->init_hw = init_ring_common;
2046 	engine->reset_hw = reset_ring_common;
2047 
2048 	engine->context_pin = intel_ring_context_pin;
2049 	engine->context_unpin = intel_ring_context_unpin;
2050 
2051 	engine->request_alloc = ring_request_alloc;
2052 
2053 	engine->emit_breadcrumb = i9xx_emit_breadcrumb;
2054 	engine->emit_breadcrumb_sz = i9xx_emit_breadcrumb_sz;
2055 	if (i915_modparams.semaphores) {
2056 		int num_rings;
2057 
2058 		engine->emit_breadcrumb = gen6_sema_emit_breadcrumb;
2059 
2060 		num_rings = INTEL_INFO(dev_priv)->num_rings - 1;
2061 		if (INTEL_GEN(dev_priv) >= 8) {
2062 			engine->emit_breadcrumb_sz += num_rings * 6;
2063 		} else {
2064 			engine->emit_breadcrumb_sz += num_rings * 3;
2065 			if (num_rings & 1)
2066 				engine->emit_breadcrumb_sz++;
2067 		}
2068 	}
2069 
2070 	engine->set_default_submission = i9xx_set_default_submission;
2071 
2072 	if (INTEL_GEN(dev_priv) >= 8)
2073 		engine->emit_bb_start = gen8_emit_bb_start;
2074 	else if (INTEL_GEN(dev_priv) >= 6)
2075 		engine->emit_bb_start = gen6_emit_bb_start;
2076 	else if (INTEL_GEN(dev_priv) >= 4)
2077 		engine->emit_bb_start = i965_emit_bb_start;
2078 	else if (IS_I830(dev_priv) || IS_I845G(dev_priv))
2079 		engine->emit_bb_start = i830_emit_bb_start;
2080 	else
2081 		engine->emit_bb_start = i915_emit_bb_start;
2082 }
2083 
2084 int intel_init_render_ring_buffer(struct intel_engine_cs *engine)
2085 {
2086 	struct drm_i915_private *dev_priv = engine->i915;
2087 	int ret;
2088 
2089 	intel_ring_default_vfuncs(dev_priv, engine);
2090 
2091 	if (HAS_L3_DPF(dev_priv))
2092 		engine->irq_keep_mask = GT_RENDER_L3_PARITY_ERROR_INTERRUPT;
2093 
2094 	if (INTEL_GEN(dev_priv) >= 8) {
2095 		engine->init_context = intel_rcs_ctx_init;
2096 		engine->emit_breadcrumb = gen8_render_emit_breadcrumb;
2097 		engine->emit_breadcrumb_sz = gen8_render_emit_breadcrumb_sz;
2098 		engine->emit_flush = gen8_render_ring_flush;
2099 		if (i915_modparams.semaphores) {
2100 			int num_rings;
2101 
2102 			engine->semaphore.signal = gen8_rcs_signal;
2103 
2104 			num_rings = INTEL_INFO(dev_priv)->num_rings - 1;
2105 			engine->emit_breadcrumb_sz += num_rings * 8;
2106 		}
2107 	} else if (INTEL_GEN(dev_priv) >= 6) {
2108 		engine->init_context = intel_rcs_ctx_init;
2109 		engine->emit_flush = gen7_render_ring_flush;
2110 		if (IS_GEN6(dev_priv))
2111 			engine->emit_flush = gen6_render_ring_flush;
2112 	} else if (IS_GEN5(dev_priv)) {
2113 		engine->emit_flush = gen4_render_ring_flush;
2114 	} else {
2115 		if (INTEL_GEN(dev_priv) < 4)
2116 			engine->emit_flush = gen2_render_ring_flush;
2117 		else
2118 			engine->emit_flush = gen4_render_ring_flush;
2119 		engine->irq_enable_mask = I915_USER_INTERRUPT;
2120 	}
2121 
2122 	if (IS_HASWELL(dev_priv))
2123 		engine->emit_bb_start = hsw_emit_bb_start;
2124 
2125 	engine->init_hw = init_render_ring;
2126 	engine->cleanup = render_ring_cleanup;
2127 
2128 	ret = intel_init_ring_buffer(engine);
2129 	if (ret)
2130 		return ret;
2131 
2132 	if (INTEL_GEN(dev_priv) >= 6) {
2133 		ret = intel_engine_create_scratch(engine, PAGE_SIZE);
2134 		if (ret)
2135 			return ret;
2136 	} else if (HAS_BROKEN_CS_TLB(dev_priv)) {
2137 		ret = intel_engine_create_scratch(engine, I830_WA_SIZE);
2138 		if (ret)
2139 			return ret;
2140 	}
2141 
2142 	return 0;
2143 }
2144 
2145 int intel_init_bsd_ring_buffer(struct intel_engine_cs *engine)
2146 {
2147 	struct drm_i915_private *dev_priv = engine->i915;
2148 
2149 	intel_ring_default_vfuncs(dev_priv, engine);
2150 
2151 	if (INTEL_GEN(dev_priv) >= 6) {
2152 		/* gen6 bsd needs a special wa for tail updates */
2153 		if (IS_GEN6(dev_priv))
2154 			engine->set_default_submission = gen6_bsd_set_default_submission;
2155 		engine->emit_flush = gen6_bsd_ring_flush;
2156 		if (INTEL_GEN(dev_priv) < 8)
2157 			engine->irq_enable_mask = GT_BSD_USER_INTERRUPT;
2158 	} else {
2159 		engine->mmio_base = BSD_RING_BASE;
2160 		engine->emit_flush = bsd_ring_flush;
2161 		if (IS_GEN5(dev_priv))
2162 			engine->irq_enable_mask = ILK_BSD_USER_INTERRUPT;
2163 		else
2164 			engine->irq_enable_mask = I915_BSD_USER_INTERRUPT;
2165 	}
2166 
2167 	return intel_init_ring_buffer(engine);
2168 }
2169 
2170 int intel_init_blt_ring_buffer(struct intel_engine_cs *engine)
2171 {
2172 	struct drm_i915_private *dev_priv = engine->i915;
2173 
2174 	intel_ring_default_vfuncs(dev_priv, engine);
2175 
2176 	engine->emit_flush = gen6_ring_flush;
2177 	if (INTEL_GEN(dev_priv) < 8)
2178 		engine->irq_enable_mask = GT_BLT_USER_INTERRUPT;
2179 
2180 	return intel_init_ring_buffer(engine);
2181 }
2182 
2183 int intel_init_vebox_ring_buffer(struct intel_engine_cs *engine)
2184 {
2185 	struct drm_i915_private *dev_priv = engine->i915;
2186 
2187 	intel_ring_default_vfuncs(dev_priv, engine);
2188 
2189 	engine->emit_flush = gen6_ring_flush;
2190 
2191 	if (INTEL_GEN(dev_priv) < 8) {
2192 		engine->irq_enable_mask = PM_VEBOX_USER_INTERRUPT;
2193 		engine->irq_enable = hsw_vebox_irq_enable;
2194 		engine->irq_disable = hsw_vebox_irq_disable;
2195 	}
2196 
2197 	return intel_init_ring_buffer(engine);
2198 }
2199