1 files changed, 339 insertions, 408 deletions

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 8da1bde442dd..e2085820b586 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -28,9 +28,12 @@
  */
 
 #include <linux/log2.h>
+
 #include <drm/drmP.h>
-#include "i915_drv.h"
 #include <drm/i915_drm.h>
+
+#include "i915_drv.h"
+#include "i915_gem_render_state.h"
 #include "i915_trace.h"
 #include "intel_drv.h"
 
@@ -337,50 +340,6 @@ gen7_render_ring_flush(struct drm_i915_gem_request *req, u32 mode)
 	return 0;
 }
 
-static int
-gen8_render_ring_flush(struct drm_i915_gem_request *req, u32 mode)
-{
-	u32 flags;
-	u32 *cs;
-
-	cs = intel_ring_begin(req, mode & EMIT_INVALIDATE ? 12 : 6);
-	if (IS_ERR(cs))
-		return PTR_ERR(cs);
-
-	flags = PIPE_CONTROL_CS_STALL;
-
-	if (mode & EMIT_FLUSH) {
-		flags |= PIPE_CONTROL_RENDER_TARGET_CACHE_FLUSH;
-		flags |= PIPE_CONTROL_DEPTH_CACHE_FLUSH;
-		flags |= PIPE_CONTROL_DC_FLUSH_ENABLE;
-		flags |= PIPE_CONTROL_FLUSH_ENABLE;
-	}
-	if (mode & EMIT_INVALIDATE) {
-		flags |= PIPE_CONTROL_TLB_INVALIDATE;
-		flags |= PIPE_CONTROL_INSTRUCTION_CACHE_INVALIDATE;
-		flags |= PIPE_CONTROL_TEXTURE_CACHE_INVALIDATE;
-		flags |= PIPE_CONTROL_VF_CACHE_INVALIDATE;
-		flags |= PIPE_CONTROL_CONST_CACHE_INVALIDATE;
-		flags |= PIPE_CONTROL_STATE_CACHE_INVALIDATE;
-		flags |= PIPE_CONTROL_QW_WRITE;
-		flags |= PIPE_CONTROL_GLOBAL_GTT_IVB;
-
-		/* WaCsStallBeforeStateCacheInvalidate:bdw,chv */
-		cs = gen8_emit_pipe_control(cs,
-					    PIPE_CONTROL_CS_STALL |
-					    PIPE_CONTROL_STALL_AT_SCOREBOARD,
-					    0);
-	}
-
-	cs = gen8_emit_pipe_control(cs, flags,
-				    i915_ggtt_offset(req->engine->scratch) +
-				    2 * CACHELINE_BYTES);
-
-	intel_ring_advance(req, cs);
-
-	return 0;
-}
-
 static void ring_setup_phys_status_page(struct intel_engine_cs *engine)
 {
 	struct drm_i915_private *dev_priv = engine->i915;
@@ -424,7 +383,6 @@ static void intel_ring_setup_status_page(struct intel_engine_cs *engine)
 	} else if (IS_GEN6(dev_priv)) {
 		mmio = RING_HWS_PGA_GEN6(engine->mmio_base);
 	} else {
-		/* XXX: gen8 returns to sanity */
 		mmio = RING_HWS_PGA(engine->mmio_base);
 	}
 
@@ -434,13 +392,7 @@ static void intel_ring_setup_status_page(struct intel_engine_cs *engine)
 	I915_WRITE(mmio, engine->status_page.ggtt_offset);
 	POSTING_READ(mmio);
 
-	/*
-	 * Flush the TLB for this page
-	 *
-	 * FIXME: These two bits have disappeared on gen8, so a question
-	 * arises: do we still need this and if so how should we go about
-	 * invalidating the TLB?
-	 */
+	/* Flush the TLB for this page */
 	if (IS_GEN(dev_priv, 6, 7)) {
 		i915_reg_t reg = RING_INSTPM(engine->mmio_base);
 
@@ -480,10 +432,14 @@ static bool stop_ring(struct intel_engine_cs *engine)
 		}
 	}
 
-	I915_WRITE_CTL(engine, 0);
+	I915_WRITE_HEAD(engine, I915_READ_TAIL(engine));
+
 	I915_WRITE_HEAD(engine, 0);
 	I915_WRITE_TAIL(engine, 0);
 
+	/* The ring must be empty before it is disabled */
+	I915_WRITE_CTL(engine, 0);
+
 	return (I915_READ_HEAD(engine) & HEAD_ADDR) == 0;
 }
 
@@ -604,8 +560,6 @@ static void reset_ring_common(struct intel_engine_cs *engine,
 		struct intel_context *ce = &request->ctx->engine[engine->id];
 		struct i915_hw_ppgtt *ppgtt;
 
-		/* FIXME consider gen8 reset */
-
 		if (ce->state) {
 			I915_WRITE(CCID,
 				   i915_ggtt_offset(ce->state) |
@@ -637,6 +591,7 @@ static void reset_ring_common(struct intel_engine_cs *engine,
 			request->ring->head = request->postfix;
 	} else {
 		engine->legacy_active_context = NULL;
+		engine->legacy_active_ppgtt = NULL;
 	}
 }
 
@@ -706,62 +661,6 @@ static int init_render_ring(struct intel_engine_cs *engine)
 	return init_workarounds_ring(engine);
 }
 
-static void render_ring_cleanup(struct intel_engine_cs *engine)
-{
-	struct drm_i915_private *dev_priv = engine->i915;
-
-	i915_vma_unpin_and_release(&dev_priv->semaphore);
-}
-
-static u32 *gen8_rcs_signal(struct drm_i915_gem_request *req, u32 *cs)
-{
-	struct drm_i915_private *dev_priv = req->i915;
-	struct intel_engine_cs *waiter;
-	enum intel_engine_id id;
-
-	for_each_engine(waiter, dev_priv, id) {
-		u64 gtt_offset = req->engine->semaphore.signal_ggtt[id];
-		if (gtt_offset == MI_SEMAPHORE_SYNC_INVALID)
-			continue;
-
-		*cs++ = GFX_OP_PIPE_CONTROL(6);
-		*cs++ = PIPE_CONTROL_GLOBAL_GTT_IVB | PIPE_CONTROL_QW_WRITE |
-			PIPE_CONTROL_CS_STALL;
-		*cs++ = lower_32_bits(gtt_offset);
-		*cs++ = upper_32_bits(gtt_offset);
-		*cs++ = req->global_seqno;
-		*cs++ = 0;
-		*cs++ = MI_SEMAPHORE_SIGNAL |
-			MI_SEMAPHORE_TARGET(waiter->hw_id);
-		*cs++ = 0;
-	}
-
-	return cs;
-}
-
-static u32 *gen8_xcs_signal(struct drm_i915_gem_request *req, u32 *cs)
-{
-	struct drm_i915_private *dev_priv = req->i915;
-	struct intel_engine_cs *waiter;
-	enum intel_engine_id id;
-
-	for_each_engine(waiter, dev_priv, id) {
-		u64 gtt_offset = req->engine->semaphore.signal_ggtt[id];
-		if (gtt_offset == MI_SEMAPHORE_SYNC_INVALID)
-			continue;
-
-		*cs++ = (MI_FLUSH_DW + 1) | MI_FLUSH_DW_OP_STOREDW;
-		*cs++ = lower_32_bits(gtt_offset) | MI_FLUSH_DW_USE_GTT;
-		*cs++ = upper_32_bits(gtt_offset);
-		*cs++ = req->global_seqno;
-		*cs++ = MI_SEMAPHORE_SIGNAL |
-			MI_SEMAPHORE_TARGET(waiter->hw_id);
-		*cs++ = 0;
-	}
-
-	return cs;
-}
-
 static u32 *gen6_signal(struct drm_i915_gem_request *req, u32 *cs)
 {
 	struct drm_i915_private *dev_priv = req->i915;
@@ -844,70 +743,6 @@ static void gen6_sema_emit_breadcrumb(struct drm_i915_gem_request *req, u32 *cs)
 				    req->engine->semaphore.signal(req, cs));
 }
 
-static void gen8_render_emit_breadcrumb(struct drm_i915_gem_request *req,
-					u32 *cs)
-{
-	struct intel_engine_cs *engine = req->engine;
-
-	if (engine->semaphore.signal)
-		cs = engine->semaphore.signal(req, cs);
-
-	*cs++ = GFX_OP_PIPE_CONTROL(6);
-	*cs++ = PIPE_CONTROL_GLOBAL_GTT_IVB | PIPE_CONTROL_CS_STALL |
-		PIPE_CONTROL_QW_WRITE;
-	*cs++ = intel_hws_seqno_address(engine);
-	*cs++ = 0;
-	*cs++ = req->global_seqno;
-	/* We're thrashing one dword of HWS. */
-	*cs++ = 0;
-	*cs++ = MI_USER_INTERRUPT;
-	*cs++ = MI_NOOP;
-
-	req->tail = intel_ring_offset(req, cs);
-	assert_ring_tail_valid(req->ring, req->tail);
-}
-
-static const int gen8_render_emit_breadcrumb_sz = 8;
-
-/**
- * intel_ring_sync - sync the waiter to the signaller on seqno
- *
- * @waiter - ring that is waiting
- * @signaller - ring which has, or will signal
- * @seqno - seqno which the waiter will block on
- */
-
-static int
-gen8_ring_sync_to(struct drm_i915_gem_request *req,
-		  struct drm_i915_gem_request *signal)
-{
-	struct drm_i915_private *dev_priv = req->i915;
-	u64 offset = GEN8_WAIT_OFFSET(req->engine, signal->engine->id);
-	struct i915_hw_ppgtt *ppgtt;
-	u32 *cs;
-
-	cs = intel_ring_begin(req, 4);
-	if (IS_ERR(cs))
-		return PTR_ERR(cs);
-
-	*cs++ = MI_SEMAPHORE_WAIT | MI_SEMAPHORE_GLOBAL_GTT |
-		MI_SEMAPHORE_SAD_GTE_SDD;
-	*cs++ = signal->global_seqno;
-	*cs++ = lower_32_bits(offset);
-	*cs++ = upper_32_bits(offset);
-	intel_ring_advance(req, cs);
-
-	/* When the !RCS engines idle waiting upon a semaphore, they lose their
-	 * pagetables and we must reload them before executing the batch.
-	 * We do this on the i915_switch_context() following the wait and
-	 * before the dispatch.
-	 */
-	ppgtt = req->ctx->ppgtt;
-	if (ppgtt && req->engine->id != RCS)
-		ppgtt->pd_dirty_rings |= intel_engine_flag(req->engine);
-	return 0;
-}
-
 static int
 gen6_ring_sync_to(struct drm_i915_gem_request *req,
 		  struct drm_i915_gem_request *signal)
@@ -1083,25 +918,6 @@ hsw_vebox_irq_disable(struct intel_engine_cs *engine)
 	gen6_mask_pm_irq(dev_priv, engine->irq_enable_mask);
 }
 
-static void
-gen8_irq_enable(struct intel_engine_cs *engine)
-{
-	struct drm_i915_private *dev_priv = engine->i915;
-
-	I915_WRITE_IMR(engine,
-		       ~(engine->irq_enable_mask |
-			 engine->irq_keep_mask));
-	POSTING_READ_FW(RING_IMR(engine->mmio_base));
-}
-
-static void
-gen8_irq_disable(struct intel_engine_cs *engine)
-{
-	struct drm_i915_private *dev_priv = engine->i915;
-
-	I915_WRITE_IMR(engine, ~engine->irq_keep_mask);
-}
-
 static int
 i965_emit_bb_start(struct drm_i915_gem_request *req,
 		   u64 offset, u32 length,
@@ -1359,12 +1175,13 @@ static int context_pin(struct i915_gem_context *ctx)
 	struct i915_vma *vma = ctx->engine[RCS].state;
 	int ret;
 
-	/* Clear this page out of any CPU caches for coherent swap-in/out.
+	/*
+	 * Clear this page out of any CPU caches for coherent swap-in/out.
 	 * We only want to do this on the first bind so that we do not stall
 	 * on an active context (which by nature is already on the GPU).
 	 */
 	if (!(vma->flags & I915_VMA_GLOBAL_BIND)) {
-		ret = i915_gem_object_set_to_gtt_domain(vma->obj, false);
+		ret = i915_gem_object_set_to_gtt_domain(vma->obj, true);
 		if (ret)
 			return ret;
 	}
@@ -1379,11 +1196,34 @@ alloc_context_vma(struct intel_engine_cs *engine)
 	struct drm_i915_private *i915 = engine->i915;
 	struct drm_i915_gem_object *obj;
 	struct i915_vma *vma;
+	int err;
 
 	obj = i915_gem_object_create(i915, engine->context_size);
 	if (IS_ERR(obj))
 		return ERR_CAST(obj);
 
+	if (engine->default_state) {
+		void *defaults, *vaddr;
+
+		vaddr = i915_gem_object_pin_map(obj, I915_MAP_WB);
+		if (IS_ERR(vaddr)) {
+			err = PTR_ERR(vaddr);
+			goto err_obj;
+		}
+
+		defaults = i915_gem_object_pin_map(engine->default_state,
+						   I915_MAP_WB);
+		if (IS_ERR(defaults)) {
+			err = PTR_ERR(defaults);
+			goto err_map;
+		}
+
+		memcpy(vaddr, defaults, engine->context_size);
+
+		i915_gem_object_unpin_map(engine->default_state);
+		i915_gem_object_unpin_map(obj);
+	}
+
 	/*
 	 * Try to make the context utilize L3 as well as LLC.
 	 *
@@ -1405,10 +1245,18 @@ alloc_context_vma(struct intel_engine_cs *engine)
 	}
 
 	vma = i915_vma_instance(obj, &i915->ggtt.base, NULL);
-	if (IS_ERR(vma))
-		i915_gem_object_put(obj);
+	if (IS_ERR(vma)) {
+		err = PTR_ERR(vma);
+		goto err_obj;
+	}
 
 	return vma;
+
+err_map:
+	i915_gem_object_unpin_map(obj);
+err_obj:
+	i915_gem_object_put(obj);
+	return ERR_PTR(err);
 }
 
 static struct intel_ring *
@@ -1441,20 +1289,9 @@ intel_ring_context_pin(struct intel_engine_cs *engine,
 		if (ret)
 			goto err;
 
-		ce->state->obj->mm.dirty = true;
 		ce->state->obj->pin_global++;
 	}
 
-	/* The kernel context is only used as a placeholder for flushing the
-	 * active context. It is never used for submitting user rendering and
-	 * as such never requires the golden render context, and so we can skip
-	 * emitting it when we switch to the kernel context. This is required
-	 * as during eviction we cannot allocate and pin the renderstate in
-	 * order to initialise the context.
-	 */
-	if (i915_gem_context_is_kernel(ctx))
-		ce->initialised = true;
-
 	i915_gem_context_get(ctx);
 
 out:
@@ -1548,10 +1385,194 @@ void intel_legacy_submission_resume(struct drm_i915_private *dev_priv)
 		intel_ring_reset(engine->buffer, 0);
 }
 
-static int ring_request_alloc(struct drm_i915_gem_request *request)
+static inline int mi_set_context(struct drm_i915_gem_request *rq, u32 flags)
 {
+	struct drm_i915_private *i915 = rq->i915;
+	struct intel_engine_cs *engine = rq->engine;
+	enum intel_engine_id id;
+	const int num_rings =
+		/* Use an extended w/a on gen7 if signalling from other rings */
+		(HAS_LEGACY_SEMAPHORES(i915) && IS_GEN7(i915)) ?
+		INTEL_INFO(i915)->num_rings - 1 :
+		0;
+	int len;
 	u32 *cs;
 
+	flags |= MI_MM_SPACE_GTT;
+	if (IS_HASWELL(i915))
+		/* These flags are for resource streamer on HSW+ */
+		flags |= HSW_MI_RS_SAVE_STATE_EN | HSW_MI_RS_RESTORE_STATE_EN;
+	else
+		flags |= MI_SAVE_EXT_STATE_EN | MI_RESTORE_EXT_STATE_EN;
+
+	len = 4;
+	if (IS_GEN7(i915))
+		len += 2 + (num_rings ? 4*num_rings + 6 : 0);
+
+	cs = intel_ring_begin(rq, len);
+	if (IS_ERR(cs))
+		return PTR_ERR(cs);
+
+	/* WaProgramMiArbOnOffAroundMiSetContext:ivb,vlv,hsw,bdw,chv */
+	if (IS_GEN7(i915)) {
+		*cs++ = MI_ARB_ON_OFF | MI_ARB_DISABLE;
+		if (num_rings) {
+			struct intel_engine_cs *signaller;
+
+			*cs++ = MI_LOAD_REGISTER_IMM(num_rings);
+			for_each_engine(signaller, i915, id) {
+				if (signaller == engine)
+					continue;
+
+				*cs++ = i915_mmio_reg_offset(
+					   RING_PSMI_CTL(signaller->mmio_base));
+				*cs++ = _MASKED_BIT_ENABLE(
+						GEN6_PSMI_SLEEP_MSG_DISABLE);
+			}
+		}
+	}
+
+	*cs++ = MI_NOOP;
+	*cs++ = MI_SET_CONTEXT;
+	*cs++ = i915_ggtt_offset(rq->ctx->engine[RCS].state) | flags;
+	/*
+	 * w/a: MI_SET_CONTEXT must always be followed by MI_NOOP
+	 * WaMiSetContext_Hang:snb,ivb,vlv
+	 */
+	*cs++ = MI_NOOP;
+
+	if (IS_GEN7(i915)) {
+		if (num_rings) {
+			struct intel_engine_cs *signaller;
+			i915_reg_t last_reg = {}; /* keep gcc quiet */
+
+			*cs++ = MI_LOAD_REGISTER_IMM(num_rings);
+			for_each_engine(signaller, i915, id) {
+				if (signaller == engine)
+					continue;
+
+				last_reg = RING_PSMI_CTL(signaller->mmio_base);
+				*cs++ = i915_mmio_reg_offset(last_reg);
+				*cs++ = _MASKED_BIT_DISABLE(
+						GEN6_PSMI_SLEEP_MSG_DISABLE);
+			}
+
+			/* Insert a delay before the next switch! */
+			*cs++ = MI_STORE_REGISTER_MEM | MI_SRM_LRM_GLOBAL_GTT;
+			*cs++ = i915_mmio_reg_offset(last_reg);
+			*cs++ = i915_ggtt_offset(engine->scratch);
+			*cs++ = MI_NOOP;
+		}
+		*cs++ = MI_ARB_ON_OFF | MI_ARB_ENABLE;
+	}
+
+	intel_ring_advance(rq, cs);
+
+	return 0;
+}
+
+static int remap_l3(struct drm_i915_gem_request *rq, int slice)
+{
+	u32 *cs, *remap_info = rq->i915->l3_parity.remap_info[slice];
+	int i;
+
+	if (!remap_info)
+		return 0;
+
+	cs = intel_ring_begin(rq, GEN7_L3LOG_SIZE/4 * 2 + 2);
+	if (IS_ERR(cs))
+		return PTR_ERR(cs);
+
+	/*
+	 * Note: We do not worry about the concurrent register cacheline hang
+	 * here because no other code should access these registers other than
+	 * at initialization time.
+	 */
+	*cs++ = MI_LOAD_REGISTER_IMM(GEN7_L3LOG_SIZE/4);
+	for (i = 0; i < GEN7_L3LOG_SIZE/4; i++) {
+		*cs++ = i915_mmio_reg_offset(GEN7_L3LOG(slice, i));
+		*cs++ = remap_info[i];
+	}
+	*cs++ = MI_NOOP;
+	intel_ring_advance(rq, cs);
+
+	return 0;
+}
+
+static int switch_context(struct drm_i915_gem_request *rq)
+{
+	struct intel_engine_cs *engine = rq->engine;
+	struct i915_gem_context *to_ctx = rq->ctx;
+	struct i915_hw_ppgtt *to_mm =
+		to_ctx->ppgtt ?: rq->i915->mm.aliasing_ppgtt;
+	struct i915_gem_context *from_ctx = engine->legacy_active_context;
+	struct i915_hw_ppgtt *from_mm = engine->legacy_active_ppgtt;
+	u32 hw_flags = 0;
+	int ret, i;
+
+	lockdep_assert_held(&rq->i915->drm.struct_mutex);
+	GEM_BUG_ON(HAS_EXECLISTS(rq->i915));
+
+	if (to_mm != from_mm ||
+	    (to_mm && intel_engine_flag(engine) & to_mm->pd_dirty_rings)) {
+		trace_switch_mm(engine, to_ctx);
+		ret = to_mm->switch_mm(to_mm, rq);
+		if (ret)
+			goto err;
+
+		to_mm->pd_dirty_rings &= ~intel_engine_flag(engine);
+		engine->legacy_active_ppgtt = to_mm;
+		hw_flags = MI_FORCE_RESTORE;
+	}
+
+	if (to_ctx->engine[engine->id].state &&
+	    (to_ctx != from_ctx || hw_flags & MI_FORCE_RESTORE)) {
+		GEM_BUG_ON(engine->id != RCS);
+
+		/*
+		 * The kernel context(s) is treated as pure scratch and is not
+		 * expected to retain any state (as we sacrifice it during
+		 * suspend and on resume it may be corrupted). This is ok,
+		 * as nothing actually executes using the kernel context; it
+		 * is purely used for flushing user contexts.
+		 */
+		if (i915_gem_context_is_kernel(to_ctx))
+			hw_flags = MI_RESTORE_INHIBIT;
+
+		ret = mi_set_context(rq, hw_flags);
+		if (ret)
+			goto err_mm;
+
+		engine->legacy_active_context = to_ctx;
+	}
+
+	if (to_ctx->remap_slice) {
+		for (i = 0; i < MAX_L3_SLICES; i++) {
+			if (!(to_ctx->remap_slice & BIT(i)))
+				continue;
+
+			ret = remap_l3(rq, i);
+			if (ret)
+				goto err_ctx;
+		}
+
+		to_ctx->remap_slice = 0;
+	}
+
+	return 0;
+
+err_ctx:
+	engine->legacy_active_context = from_ctx;
+err_mm:
+	engine->legacy_active_ppgtt = from_mm;
+err:
+	return ret;
+}
+
+static int ring_request_alloc(struct drm_i915_gem_request *request)
+{
+	int ret;
+
 	GEM_BUG_ON(!request->ctx->engine[request->engine->id].pin_count);
 
 	/* Flush enough space to reduce the likelihood of waiting after
@@ -1560,37 +1581,28 @@ static int ring_request_alloc(struct drm_i915_gem_request *request)
 	 */
 	request->reserved_space += LEGACY_REQUEST_SIZE;
 
-	cs = intel_ring_begin(request, 0);
-	if (IS_ERR(cs))
-		return PTR_ERR(cs);
+	ret = intel_ring_wait_for_space(request->ring, request->reserved_space);
+	if (ret)
+		return ret;
+
+	ret = switch_context(request);
+	if (ret)
+		return ret;
 
 	request->reserved_space -= LEGACY_REQUEST_SIZE;
 	return 0;
 }
 
-static noinline int wait_for_space(struct drm_i915_gem_request *req,
-				   unsigned int bytes)
+static noinline int wait_for_space(struct intel_ring *ring, unsigned int bytes)
 {
-	struct intel_ring *ring = req->ring;
 	struct drm_i915_gem_request *target;
 	long timeout;
 
-	lockdep_assert_held(&req->i915->drm.struct_mutex);
+	lockdep_assert_held(&ring->vma->vm->i915->drm.struct_mutex);
 
 	if (intel_ring_update_space(ring) >= bytes)
 		return 0;
 
-	/*
-	 * Space is reserved in the ringbuffer for finalising the request,
-	 * as that cannot be allowed to fail. During request finalisation,
-	 * reserved_space is set to 0 to stop the overallocation and the
-	 * assumption is that then we never need to wait (which has the
-	 * risk of failing with EINTR).
-	 *
-	 * See also i915_gem_request_alloc() and i915_add_request().
-	 */
-	GEM_BUG_ON(!req->reserved_space);
-
 	list_for_each_entry(target, &ring->request_list, ring_link) {
 		/* Would completion of this request free enough space? */
 		if (bytes <= __intel_ring_space(target->postfix,
@@ -1614,6 +1626,22 @@ static noinline int wait_for_space(struct drm_i915_gem_request *req,
 	return 0;
 }
 
+int intel_ring_wait_for_space(struct intel_ring *ring, unsigned int bytes)
+{
+	GEM_BUG_ON(bytes > ring->effective_size);
+	if (unlikely(bytes > ring->effective_size - ring->emit))
+		bytes += ring->size - ring->emit;
+
+	if (unlikely(bytes > ring->space)) {
+		int ret = wait_for_space(ring, bytes);
+		if (unlikely(ret))
+			return ret;
+	}
+
+	GEM_BUG_ON(ring->space < bytes);
+	return 0;
+}
+
 u32 *intel_ring_begin(struct drm_i915_gem_request *req,
 		      unsigned int num_dwords)
 {
@@ -1653,7 +1681,20 @@ u32 *intel_ring_begin(struct drm_i915_gem_request *req,
 	}
 
 	if (unlikely(total_bytes > ring->space)) {
-		int ret = wait_for_space(req, total_bytes);
+		int ret;
+
+		/*
+		 * Space is reserved in the ringbuffer for finalising the
+		 * request, as that cannot be allowed to fail. During request
+		 * finalisation, reserved_space is set to 0 to stop the
+		 * overallocation and the assumption is that then we never need
+		 * to wait (which has the risk of failing with EINTR).
+		 *
+		 * See also i915_gem_request_alloc() and i915_add_request().
+		 */
+		GEM_BUG_ON(!req->reserved_space);
+
+		ret = wait_for_space(ring, total_bytes);
 		if (unlikely(ret))
 			return ERR_PTR(ret);
 	}
@@ -1748,8 +1789,6 @@ static int gen6_bsd_ring_flush(struct drm_i915_gem_request *req, u32 mode)
 		return PTR_ERR(cs);
 
 	cmd = MI_FLUSH_DW;
-	if (INTEL_GEN(req->i915) >= 8)
-		cmd += 1;
 
 	/* We always require a command barrier so that subsequent
 	 * commands, such as breadcrumb interrupts, are strictly ordered
@@ -1769,38 +1808,9 @@ static int gen6_bsd_ring_flush(struct drm_i915_gem_request *req, u32 mode)
 
 	*cs++ = cmd;
 	*cs++ = I915_GEM_HWS_SCRATCH_ADDR | MI_FLUSH_DW_USE_GTT;
-	if (INTEL_GEN(req->i915) >= 8) {
-		*cs++ = 0; /* upper addr */
-		*cs++ = 0; /* value */
-	} else  {
-		*cs++ = 0;
-		*cs++ = MI_NOOP;
-	}
-	intel_ring_advance(req, cs);
-	return 0;
-}
-
-static int
-gen8_emit_bb_start(struct drm_i915_gem_request *req,
-		   u64 offset, u32 len,
-		   unsigned int dispatch_flags)
-{
-	bool ppgtt = USES_PPGTT(req->i915) &&
-			!(dispatch_flags & I915_DISPATCH_SECURE);
-	u32 *cs;
-
-	cs = intel_ring_begin(req, 4);
-	if (IS_ERR(cs))
-		return PTR_ERR(cs);
-
-	/* FIXME(BDW): Address space and security selectors. */
-	*cs++ = MI_BATCH_BUFFER_START_GEN8 | (ppgtt << 8) | (dispatch_flags &
-		I915_DISPATCH_RS ? MI_BATCH_RESOURCE_STREAMER : 0);
-	*cs++ = lower_32_bits(offset);
-	*cs++ = upper_32_bits(offset);
+	*cs++ = 0;
 	*cs++ = MI_NOOP;
 	intel_ring_advance(req, cs);
-
 	return 0;
 }
 
@@ -1857,8 +1867,6 @@ static int gen6_ring_flush(struct drm_i915_gem_request *req, u32 mode)
 		return PTR_ERR(cs);
 
 	cmd = MI_FLUSH_DW;
-	if (INTEL_GEN(req->i915) >= 8)
-		cmd += 1;
 
 	/* We always require a command barrier so that subsequent
 	 * commands, such as breadcrumb interrupts, are strictly ordered
@@ -1877,13 +1885,8 @@ static int gen6_ring_flush(struct drm_i915_gem_request *req, u32 mode)
 		cmd |= MI_INVALIDATE_TLB;
 	*cs++ = cmd;
 	*cs++ = I915_GEM_HWS_SCRATCH_ADDR | MI_FLUSH_DW_USE_GTT;
-	if (INTEL_GEN(req->i915) >= 8) {
-		*cs++ = 0; /* upper addr */
-		*cs++ = 0; /* value */
-	} else  {
-		*cs++ = 0;
-		*cs++ = MI_NOOP;
-	}
+	*cs++ = 0;
+	*cs++ = MI_NOOP;
 	intel_ring_advance(req, cs);
 
 	return 0;
@@ -1892,110 +1895,61 @@ static int gen6_ring_flush(struct drm_i915_gem_request *req, u32 mode)
 static void intel_ring_init_semaphores(struct drm_i915_private *dev_priv,
 				       struct intel_engine_cs *engine)
 {
-	struct drm_i915_gem_object *obj;
-	int ret, i;
+	int i;
 
-	if (!i915_modparams.semaphores)
+	if (!HAS_LEGACY_SEMAPHORES(dev_priv))
 		return;
 
-	if (INTEL_GEN(dev_priv) >= 8 && !dev_priv->semaphore) {
-		struct i915_vma *vma;
-
-		obj = i915_gem_object_create(dev_priv, PAGE_SIZE);
-		if (IS_ERR(obj))
-			goto err;
-
-		vma = i915_vma_instance(obj, &dev_priv->ggtt.base, NULL);
-		if (IS_ERR(vma))
-			goto err_obj;
-
-		ret = i915_gem_object_set_to_gtt_domain(obj, false);
-		if (ret)
-			goto err_obj;
-
-		ret = i915_vma_pin(vma, 0, 0, PIN_GLOBAL | PIN_HIGH);
-		if (ret)
-			goto err_obj;
-
-		dev_priv->semaphore = vma;
-	}
-
-	if (INTEL_GEN(dev_priv) >= 8) {
-		u32 offset = i915_ggtt_offset(dev_priv->semaphore);
-
-		engine->semaphore.sync_to = gen8_ring_sync_to;
-		engine->semaphore.signal = gen8_xcs_signal;
-
-		for (i = 0; i < I915_NUM_ENGINES; i++) {
-			u32 ring_offset;
-
-			if (i != engine->id)
-				ring_offset = offset + GEN8_SEMAPHORE_OFFSET(engine->id, i);
-			else
-				ring_offset = MI_SEMAPHORE_SYNC_INVALID;
-
-			engine->semaphore.signal_ggtt[i] = ring_offset;
-		}
-	} else if (INTEL_GEN(dev_priv) >= 6) {
-		engine->semaphore.sync_to = gen6_ring_sync_to;
-		engine->semaphore.signal = gen6_signal;
+	GEM_BUG_ON(INTEL_GEN(dev_priv) < 6);
+	engine->semaphore.sync_to = gen6_ring_sync_to;
+	engine->semaphore.signal = gen6_signal;
 
-		/*
-		 * The current semaphore is only applied on pre-gen8
-		 * platform.  And there is no VCS2 ring on the pre-gen8
-		 * platform. So the semaphore between RCS and VCS2 is
-		 * initialized as INVALID.  Gen8 will initialize the
-		 * sema between VCS2 and RCS later.
-		 */
-		for (i = 0; i < GEN6_NUM_SEMAPHORES; i++) {
-			static const struct {
-				u32 wait_mbox;
-				i915_reg_t mbox_reg;
-			} sem_data[GEN6_NUM_SEMAPHORES][GEN6_NUM_SEMAPHORES] = {
-				[RCS_HW] = {
-					[VCS_HW] =  { .wait_mbox = MI_SEMAPHORE_SYNC_RV,  .mbox_reg = GEN6_VRSYNC },
-					[BCS_HW] =  { .wait_mbox = MI_SEMAPHORE_SYNC_RB,  .mbox_reg = GEN6_BRSYNC },
-					[VECS_HW] = { .wait_mbox = MI_SEMAPHORE_SYNC_RVE, .mbox_reg = GEN6_VERSYNC },
-				},
-				[VCS_HW] = {
-					[RCS_HW] =  { .wait_mbox = MI_SEMAPHORE_SYNC_VR,  .mbox_reg = GEN6_RVSYNC },
-					[BCS_HW] =  { .wait_mbox = MI_SEMAPHORE_SYNC_VB,  .mbox_reg = GEN6_BVSYNC },
-					[VECS_HW] = { .wait_mbox = MI_SEMAPHORE_SYNC_VVE, .mbox_reg = GEN6_VEVSYNC },
-				},
-				[BCS_HW] = {
-					[RCS_HW] =  { .wait_mbox = MI_SEMAPHORE_SYNC_BR,  .mbox_reg = GEN6_RBSYNC },
-					[VCS_HW] =  { .wait_mbox = MI_SEMAPHORE_SYNC_BV,  .mbox_reg = GEN6_VBSYNC },
-					[VECS_HW] = { .wait_mbox = MI_SEMAPHORE_SYNC_BVE, .mbox_reg = GEN6_VEBSYNC },
-				},
-				[VECS_HW] = {
-					[RCS_HW] =  { .wait_mbox = MI_SEMAPHORE_SYNC_VER, .mbox_reg = GEN6_RVESYNC },
-					[VCS_HW] =  { .wait_mbox = MI_SEMAPHORE_SYNC_VEV, .mbox_reg = GEN6_VVESYNC },
-					[BCS_HW] =  { .wait_mbox = MI_SEMAPHORE_SYNC_VEB, .mbox_reg = GEN6_BVESYNC },
-				},
-			};
+	/*
+	 * The current semaphore is only applied on pre-gen8
+	 * platform.  And there is no VCS2 ring on the pre-gen8
+	 * platform. So the semaphore between RCS and VCS2 is
+	 * initialized as INVALID.
+	 */
+	for (i = 0; i < GEN6_NUM_SEMAPHORES; i++) {
+		static const struct {
 			u32 wait_mbox;
 			i915_reg_t mbox_reg;
+		} sem_data[GEN6_NUM_SEMAPHORES][GEN6_NUM_SEMAPHORES] = {
+			[RCS_HW] = {
+				[VCS_HW] =  { .wait_mbox = MI_SEMAPHORE_SYNC_RV,  .mbox_reg = GEN6_VRSYNC },
+				[BCS_HW] =  { .wait_mbox = MI_SEMAPHORE_SYNC_RB,  .mbox_reg = GEN6_BRSYNC },
+				[VECS_HW] = { .wait_mbox = MI_SEMAPHORE_SYNC_RVE, .mbox_reg = GEN6_VERSYNC },
+			},
+			[VCS_HW] = {
+				[RCS_HW] =  { .wait_mbox = MI_SEMAPHORE_SYNC_VR,  .mbox_reg = GEN6_RVSYNC },
+				[BCS_HW] =  { .wait_mbox = MI_SEMAPHORE_SYNC_VB,  .mbox_reg = GEN6_BVSYNC },
+				[VECS_HW] = { .wait_mbox = MI_SEMAPHORE_SYNC_VVE, .mbox_reg = GEN6_VEVSYNC },
+			},
+			[BCS_HW] = {
+				[RCS_HW] =  { .wait_mbox = MI_SEMAPHORE_SYNC_BR,  .mbox_reg = GEN6_RBSYNC },
+				[VCS_HW] =  { .wait_mbox = MI_SEMAPHORE_SYNC_BV,  .mbox_reg = GEN6_VBSYNC },
+				[VECS_HW] = { .wait_mbox = MI_SEMAPHORE_SYNC_BVE, .mbox_reg = GEN6_VEBSYNC },
+			},
+			[VECS_HW] = {
+				[RCS_HW] =  { .wait_mbox = MI_SEMAPHORE_SYNC_VER, .mbox_reg = GEN6_RVESYNC },
+				[VCS_HW] =  { .wait_mbox = MI_SEMAPHORE_SYNC_VEV, .mbox_reg = GEN6_VVESYNC },
+				[BCS_HW] =  { .wait_mbox = MI_SEMAPHORE_SYNC_VEB, .mbox_reg = GEN6_BVESYNC },
+			},
+		};
+		u32 wait_mbox;
+		i915_reg_t mbox_reg;
 
-			if (i == engine->hw_id) {
-				wait_mbox = MI_SEMAPHORE_SYNC_INVALID;
-				mbox_reg = GEN6_NOSYNC;
-			} else {
-				wait_mbox = sem_data[engine->hw_id][i].wait_mbox;
-				mbox_reg = sem_data[engine->hw_id][i].mbox_reg;
-			}
-
-			engine->semaphore.mbox.wait[i] = wait_mbox;
-			engine->semaphore.mbox.signal[i] = mbox_reg;
+		if (i == engine->hw_id) {
+			wait_mbox = MI_SEMAPHORE_SYNC_INVALID;
+			mbox_reg = GEN6_NOSYNC;
+		} else {
+			wait_mbox = sem_data[engine->hw_id][i].wait_mbox;
+			mbox_reg = sem_data[engine->hw_id][i].mbox_reg;
 		}
-	}
-
-	return;
 
-err_obj:
-	i915_gem_object_put(obj);
-err:
-	DRM_DEBUG_DRIVER("Failed to allocate space for semaphores, disabling\n");
-	i915_modparams.semaphores = 0;
+		engine->semaphore.mbox.wait[i] = wait_mbox;
+		engine->semaphore.mbox.signal[i] = mbox_reg;
+	}
 }
 
 static void intel_ring_init_irq(struct drm_i915_private *dev_priv,
@@ -2003,11 +1957,7 @@ static void intel_ring_init_irq(struct drm_i915_private *dev_priv,
 {
 	engine->irq_enable_mask = GT_RENDER_USER_INTERRUPT << engine->irq_shift;
 
-	if (INTEL_GEN(dev_priv) >= 8) {
-		engine->irq_enable = gen8_irq_enable;
-		engine->irq_disable = gen8_irq_disable;
-		engine->irq_seqno_barrier = gen6_seqno_barrier;
-	} else if (INTEL_GEN(dev_priv) >= 6) {
+	if (INTEL_GEN(dev_priv) >= 6) {
 		engine->irq_enable = gen6_irq_enable;
 		engine->irq_disable = gen6_irq_disable;
 		engine->irq_seqno_barrier = gen6_seqno_barrier;
@@ -2028,17 +1978,23 @@ static void i9xx_set_default_submission(struct intel_engine_cs *engine)
 {
 	engine->submit_request = i9xx_submit_request;
 	engine->cancel_requests = cancel_requests;
+
+	engine->park = NULL;
+	engine->unpark = NULL;
 }
 
 static void gen6_bsd_set_default_submission(struct intel_engine_cs *engine)
 {
+	i9xx_set_default_submission(engine);
 	engine->submit_request = gen6_bsd_submit_request;
-	engine->cancel_requests = cancel_requests;
 }
 
 static void intel_ring_default_vfuncs(struct drm_i915_private *dev_priv,
 				      struct intel_engine_cs *engine)
 {
+	/* gen8+ are only supported with execlists */
+	GEM_BUG_ON(INTEL_GEN(dev_priv) >= 8);
+
 	intel_ring_init_irq(dev_priv, engine);
 	intel_ring_init_semaphores(dev_priv, engine);
 
@@ -2052,26 +2008,20 @@ static void intel_ring_default_vfuncs(struct drm_i915_private *dev_priv,
 
 	engine->emit_breadcrumb = i9xx_emit_breadcrumb;
 	engine->emit_breadcrumb_sz = i9xx_emit_breadcrumb_sz;
-	if (i915_modparams.semaphores) {
+	if (HAS_LEGACY_SEMAPHORES(dev_priv)) {
 		int num_rings;
 
 		engine->emit_breadcrumb = gen6_sema_emit_breadcrumb;
 
 		num_rings = INTEL_INFO(dev_priv)->num_rings - 1;
-		if (INTEL_GEN(dev_priv) >= 8) {
-			engine->emit_breadcrumb_sz += num_rings * 6;
-		} else {
-			engine->emit_breadcrumb_sz += num_rings * 3;
-			if (num_rings & 1)
-				engine->emit_breadcrumb_sz++;
-		}
+		engine->emit_breadcrumb_sz += num_rings * 3;
+		if (num_rings & 1)
+			engine->emit_breadcrumb_sz++;
 	}
 
 	engine->set_default_submission = i9xx_set_default_submission;
 
-	if (INTEL_GEN(dev_priv) >= 8)
-		engine->emit_bb_start = gen8_emit_bb_start;
-	else if (INTEL_GEN(dev_priv) >= 6)
+	if (INTEL_GEN(dev_priv) >= 6)
 		engine->emit_bb_start = gen6_emit_bb_start;
 	else if (INTEL_GEN(dev_priv) >= 4)
 		engine->emit_bb_start = i965_emit_bb_start;
@@ -2091,20 +2041,7 @@ int intel_init_render_ring_buffer(struct intel_engine_cs *engine)
 	if (HAS_L3_DPF(dev_priv))
 		engine->irq_keep_mask = GT_RENDER_L3_PARITY_ERROR_INTERRUPT;
 
-	if (INTEL_GEN(dev_priv) >= 8) {
-		engine->init_context = intel_rcs_ctx_init;
-		engine->emit_breadcrumb = gen8_render_emit_breadcrumb;
-		engine->emit_breadcrumb_sz = gen8_render_emit_breadcrumb_sz;
-		engine->emit_flush = gen8_render_ring_flush;
-		if (i915_modparams.semaphores) {
-			int num_rings;
-
-			engine->semaphore.signal = gen8_rcs_signal;
-
-			num_rings = INTEL_INFO(dev_priv)->num_rings - 1;
-			engine->emit_breadcrumb_sz += num_rings * 8;
-		}
-	} else if (INTEL_GEN(dev_priv) >= 6) {
+	if (INTEL_GEN(dev_priv) >= 6) {
 		engine->init_context = intel_rcs_ctx_init;
 		engine->emit_flush = gen7_render_ring_flush;
 		if (IS_GEN6(dev_priv))
@@ -2123,7 +2060,6 @@ int intel_init_render_ring_buffer(struct intel_engine_cs *engine)
 		engine->emit_bb_start = hsw_emit_bb_start;
 
 	engine->init_hw = init_render_ring;
-	engine->cleanup = render_ring_cleanup;
 
 	ret = intel_init_ring_buffer(engine);
 	if (ret)
@@ -2153,8 +2089,7 @@ int intel_init_bsd_ring_buffer(struct intel_engine_cs *engine)
 		if (IS_GEN6(dev_priv))
 			engine->set_default_submission = gen6_bsd_set_default_submission;
 		engine->emit_flush = gen6_bsd_ring_flush;
-		if (INTEL_GEN(dev_priv) < 8)
-			engine->irq_enable_mask = GT_BSD_USER_INTERRUPT;
+		engine->irq_enable_mask = GT_BSD_USER_INTERRUPT;
 	} else {
 		engine->mmio_base = BSD_RING_BASE;
 		engine->emit_flush = bsd_ring_flush;
@@ -2174,8 +2109,7 @@ int intel_init_blt_ring_buffer(struct intel_engine_cs *engine)
 	intel_ring_default_vfuncs(dev_priv, engine);
 
 	engine->emit_flush = gen6_ring_flush;
-	if (INTEL_GEN(dev_priv) < 8)
-		engine->irq_enable_mask = GT_BLT_USER_INTERRUPT;
+	engine->irq_enable_mask = GT_BLT_USER_INTERRUPT;
 
 	return intel_init_ring_buffer(engine);
 }
@@ -2187,12 +2121,9 @@ int intel_init_vebox_ring_buffer(struct intel_engine_cs *engine)
 	intel_ring_default_vfuncs(dev_priv, engine);
 
 	engine->emit_flush = gen6_ring_flush;
-
-	if (INTEL_GEN(dev_priv) < 8) {
-		engine->irq_enable_mask = PM_VEBOX_USER_INTERRUPT;
-		engine->irq_enable = hsw_vebox_irq_enable;
-		engine->irq_disable = hsw_vebox_irq_disable;
-	}
+	engine->irq_enable_mask = PM_VEBOX_USER_INTERRUPT;
+	engine->irq_enable = hsw_vebox_irq_enable;
+	engine->irq_disable = hsw_vebox_irq_disable;
 
 	return intel_init_ring_buffer(engine);
 }