Merge tag 'drm-intel-fixes-2017-06-20' of...

Merge tag 'drm-intel-fixes-2017-06-20' of git://anongit.freedesktop.org/git/drm-intel into drm-fixes

drm/i915 fixes for v4.12-rc7

* tag 'drm-intel-fixes-2017-06-20' of git://anongit.freedesktop.org/git/drm-intel:
  drm/i915: Don't enable backlight at setup time.
  drm/i915: Plumb the correct acquire ctx into intel_crtc_disable_noatomic()
  drm/i915: Fix deadlock witha the pipe A quirk during resume
  drm/i915: Remove __GFP_NORETRY from our buffer allocator
  drm/i915: Encourage our shrinker more when our shmemfs allocations fails
  drm/i915: Differentiate between sw write location into ring and last hw read

drivers/gpu/drm/i915/i915_gem.c

@@ -2285,8 +2285,8 @@ i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj)
 	struct page *page;
 	unsigned long last_pfn = 0;	/* suppress gcc warning */
 	unsigned int max_segment;
+	gfp_t noreclaim;
 	int ret;
-	gfp_t gfp;
 
 	/* Assert that the object is not currently in any GPU domain. As it
 	 * wasn't in the GTT, there shouldn't be any way it could have been in
@@ -2315,22 +2315,31 @@ i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj)
 	 * Fail silently without starting the shrinker
 	 */
 	mapping = obj->base.filp->f_mapping;
-	gfp = mapping_gfp_constraint(mapping, ~(__GFP_IO | __GFP_RECLAIM));
-	gfp |= __GFP_NORETRY | __GFP_NOWARN;
+	noreclaim = mapping_gfp_constraint(mapping,
+					   ~(__GFP_IO | __GFP_RECLAIM));
+	noreclaim |= __GFP_NORETRY | __GFP_NOWARN;
+
 	sg = st->sgl;
 	st->nents = 0;
 	for (i = 0; i < page_count; i++) {
-		page = shmem_read_mapping_page_gfp(mapping, i, gfp);
-		if (unlikely(IS_ERR(page))) {
-			i915_gem_shrink(dev_priv,
-					page_count,
-					I915_SHRINK_BOUND |
-					I915_SHRINK_UNBOUND |
-					I915_SHRINK_PURGEABLE);
+		const unsigned int shrink[] = {
+			I915_SHRINK_BOUND | I915_SHRINK_UNBOUND | I915_SHRINK_PURGEABLE,
+			0,
+		}, *s = shrink;
+		gfp_t gfp = noreclaim;
+
+		do {
 			page = shmem_read_mapping_page_gfp(mapping, i, gfp);
-		}
-		if (unlikely(IS_ERR(page))) {
-			gfp_t reclaim;
+			if (likely(!IS_ERR(page)))
+				break;
+
+			if (!*s) {
+				ret = PTR_ERR(page);
+				goto err_sg;
+			}
+
+			i915_gem_shrink(dev_priv, 2 * page_count, *s++);
+			cond_resched();
 
 			/* We've tried hard to allocate the memory by reaping
 			 * our own buffer, now let the real VM do its job and
@@ -2340,15 +2349,26 @@ i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj)
 			 * defer the oom here by reporting the ENOMEM back
 			 * to userspace.
 			 */
-			reclaim = mapping_gfp_mask(mapping);
-			reclaim |= __GFP_NORETRY; /* reclaim, but no oom */
-
-			page = shmem_read_mapping_page_gfp(mapping, i, reclaim);
-			if (IS_ERR(page)) {
-				ret = PTR_ERR(page);
-				goto err_sg;
+			if (!*s) {
+				/* reclaim and warn, but no oom */
+				gfp = mapping_gfp_mask(mapping);
+
+				/* Our bo are always dirty and so we require
+				 * kswapd to reclaim our pages (direct reclaim
+				 * does not effectively begin pageout of our
+				 * buffers on its own). However, direct reclaim
+				 * only waits for kswapd when under allocation
+				 * congestion. So as a result __GFP_RECLAIM is
+				 * unreliable and fails to actually reclaim our
+				 * dirty pages -- unless you try over and over
+				 * again with !__GFP_NORETRY. However, we still
+				 * want to fail this allocation rather than
+				 * trigger the out-of-memory killer and for
+				 * this we want the future __GFP_MAYFAIL.
+				 */
 			}
-		}
+		} while (1);
+
 		if (!i ||
 		    sg->length >= max_segment ||
 		    page_to_pfn(page) != last_pfn + 1) {
@@ -4222,6 +4242,7 @@ i915_gem_object_create(struct drm_i915_private *dev_priv, u64 size)
 
 	mapping = obj->base.filp->f_mapping;
 	mapping_set_gfp_mask(mapping, mask);
+	GEM_BUG_ON(!(mapping_gfp_mask(mapping) & __GFP_RECLAIM));
 
 	i915_gem_object_init(obj, &i915_gem_object_ops);
 

drivers/gpu/drm/i915/i915_gem_request.c

@@ -623,7 +623,7 @@ i915_gem_request_alloc(struct intel_engine_cs *engine,
 	 * GPU processing the request, we never over-estimate the
 	 * position of the head.
 	 */
-	req->head = req->ring->tail;
+	req->head = req->ring->emit;
 
 	/* Check that we didn't interrupt ourselves with a new request */
 	GEM_BUG_ON(req->timeline->seqno != req->fence.seqno);

drivers/gpu/drm/i915/i915_guc_submission.c

@@ -480,9 +480,7 @@ static void guc_wq_item_append(struct i915_guc_client *client,
 	GEM_BUG_ON(freespace < wqi_size);
 
 	/* The GuC firmware wants the tail index in QWords, not bytes */
-	tail = rq->tail;
-	assert_ring_tail_valid(rq->ring, rq->tail);
-	tail >>= 3;
+	tail = intel_ring_set_tail(rq->ring, rq->tail) >> 3;
 	GEM_BUG_ON(tail > WQ_RING_TAIL_MAX);
 
 	/* For now workqueue item is 4 DWs; workqueue buffer is 2 pages. So we

drivers/gpu/drm/i915/intel_display.c

@@ -120,7 +120,8 @@ static void intel_crtc_init_scalers(struct intel_crtc *crtc,
 static void skylake_pfit_enable(struct intel_crtc *crtc);
 static void ironlake_pfit_disable(struct intel_crtc *crtc, bool force);
 static void ironlake_pfit_enable(struct intel_crtc *crtc);
-static void intel_modeset_setup_hw_state(struct drm_device *dev);
+static void intel_modeset_setup_hw_state(struct drm_device *dev,
+					 struct drm_modeset_acquire_ctx *ctx);
 static void intel_pre_disable_primary_noatomic(struct drm_crtc *crtc);
 
 struct intel_limit {
@@ -3449,7 +3450,7 @@ __intel_display_resume(struct drm_device *dev,
 	struct drm_crtc *crtc;
 	int i, ret;
 
-	intel_modeset_setup_hw_state(dev);
+	intel_modeset_setup_hw_state(dev, ctx);
 	i915_redisable_vga(to_i915(dev));
 
 	if (!state)
@@ -5825,7 +5826,8 @@ static void i9xx_crtc_disable(struct intel_crtc_state *old_crtc_state,
 		intel_update_watermarks(intel_crtc);
 }
 
-static void intel_crtc_disable_noatomic(struct drm_crtc *crtc)
+static void intel_crtc_disable_noatomic(struct drm_crtc *crtc,
+					struct drm_modeset_acquire_ctx *ctx)
 {
 	struct intel_encoder *encoder;
 	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
@@ -5855,7 +5857,7 @@ static void intel_crtc_disable_noatomic(struct drm_crtc *crtc)
 		return;
 	}
 
-	state->acquire_ctx = crtc->dev->mode_config.acquire_ctx;
+	state->acquire_ctx = ctx;
 
 	/* Everything's already locked, -EDEADLK can't happen. */
 	crtc_state = intel_atomic_get_crtc_state(state, intel_crtc);
@@ -15030,7 +15032,7 @@ int intel_modeset_init(struct drm_device *dev)
 	intel_setup_outputs(dev_priv);
 
 	drm_modeset_lock_all(dev);
-	intel_modeset_setup_hw_state(dev);
+	intel_modeset_setup_hw_state(dev, dev->mode_config.acquire_ctx);
 	drm_modeset_unlock_all(dev);
 
 	for_each_intel_crtc(dev, crtc) {
@@ -15067,13 +15069,13 @@ int intel_modeset_init(struct drm_device *dev)
 	return 0;
 }
 
-static void intel_enable_pipe_a(struct drm_device *dev)
+static void intel_enable_pipe_a(struct drm_device *dev,
+				struct drm_modeset_acquire_ctx *ctx)
 {
 	struct intel_connector *connector;
 	struct drm_connector_list_iter conn_iter;
 	struct drm_connector *crt = NULL;
 	struct intel_load_detect_pipe load_detect_temp;
-	struct drm_modeset_acquire_ctx *ctx = dev->mode_config.acquire_ctx;
 	int ret;
 
 	/* We can't just switch on the pipe A, we need to set things up with a
@@ -15145,7 +15147,8 @@ static bool has_pch_trancoder(struct drm_i915_private *dev_priv,
 		(HAS_PCH_LPT_H(dev_priv) && pch_transcoder == TRANSCODER_A);
 }
 
-static void intel_sanitize_crtc(struct intel_crtc *crtc)
+static void intel_sanitize_crtc(struct intel_crtc *crtc,
+				struct drm_modeset_acquire_ctx *ctx)
 {
 	struct drm_device *dev = crtc->base.dev;
 	struct drm_i915_private *dev_priv = to_i915(dev);
@@ -15191,7 +15194,7 @@ static void intel_sanitize_crtc(struct intel_crtc *crtc)
 		plane = crtc->plane;
 		crtc->base.primary->state->visible = true;
 		crtc->plane = !plane;
-		intel_crtc_disable_noatomic(&crtc->base);
+		intel_crtc_disable_noatomic(&crtc->base, ctx);
 		crtc->plane = plane;
 	}
 
@@ -15201,13 +15204,13 @@ static void intel_sanitize_crtc(struct intel_crtc *crtc)
 		 * resume. Force-enable the pipe to fix this, the update_dpms
 		 * call below we restore the pipe to the right state, but leave
 		 * the required bits on. */
-		intel_enable_pipe_a(dev);
+		intel_enable_pipe_a(dev, ctx);
 	}
 
 	/* Adjust the state of the output pipe according to whether we
 	 * have active connectors/encoders. */
 	if (crtc->active && !intel_crtc_has_encoders(crtc))
-		intel_crtc_disable_noatomic(&crtc->base);
+		intel_crtc_disable_noatomic(&crtc->base, ctx);
 
 	if (crtc->active || HAS_GMCH_DISPLAY(dev_priv)) {
 		/*
@@ -15505,7 +15508,8 @@ get_encoder_power_domains(struct drm_i915_private *dev_priv)
  * and sanitizes it to the current state
  */
 static void
-intel_modeset_setup_hw_state(struct drm_device *dev)
+intel_modeset_setup_hw_state(struct drm_device *dev,
+			     struct drm_modeset_acquire_ctx *ctx)
 {
 	struct drm_i915_private *dev_priv = to_i915(dev);
 	enum pipe pipe;
@@ -15525,7 +15529,7 @@ intel_modeset_setup_hw_state(struct drm_device *dev)
 	for_each_pipe(dev_priv, pipe) {
 		crtc = intel_get_crtc_for_pipe(dev_priv, pipe);
 
-		intel_sanitize_crtc(crtc);
+		intel_sanitize_crtc(crtc, ctx);
 		intel_dump_pipe_config(crtc, crtc->config,
 				       "[setup_hw_state]");
 	}

drivers/gpu/drm/i915/intel_dp_aux_backlight.c

@@ -119,8 +119,6 @@ static int intel_dp_aux_setup_backlight(struct intel_connector *connector,
 	struct intel_dp *intel_dp = enc_to_intel_dp(&connector->encoder->base);
 	struct intel_panel *panel = &connector->panel;
 
-	intel_dp_aux_enable_backlight(connector);
-
 	if (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_BYTE_COUNT)
 		panel->backlight.max = 0xFFFF;
 	else

drivers/gpu/drm/i915/intel_lrc.c

@@ -326,8 +326,7 @@ static u64 execlists_update_context(struct drm_i915_gem_request *rq)
 		rq->ctx->ppgtt ?: rq->i915->mm.aliasing_ppgtt;
 	u32 *reg_state = ce->lrc_reg_state;
 
-	assert_ring_tail_valid(rq->ring, rq->tail);
-	reg_state[CTX_RING_TAIL+1] = rq->tail;
+	reg_state[CTX_RING_TAIL+1] = intel_ring_set_tail(rq->ring, rq->tail);
 
 	/* True 32b PPGTT with dynamic page allocation: update PDP
 	 * registers and point the unallocated PDPs to scratch page.
@@ -2036,8 +2035,7 @@ void intel_lr_context_resume(struct drm_i915_private *dev_priv)
 			ce->state->obj->mm.dirty = true;
 			i915_gem_object_unpin_map(ce->state->obj);
 
-			ce->ring->head = ce->ring->tail = 0;
-			intel_ring_update_space(ce->ring);
+			intel_ring_reset(ce->ring, 0);
 		}
 	}
 }

drivers/gpu/drm/i915/intel_ringbuffer.c

@@ -49,7 +49,7 @@ static int __intel_ring_space(int head, int tail, int size)
 
 void intel_ring_update_space(struct intel_ring *ring)
 {
-	ring->space = __intel_ring_space(ring->head, ring->tail, ring->size);
+	ring->space = __intel_ring_space(ring->head, ring->emit, ring->size);
 }
 
 static int
@@ -774,8 +774,8 @@ static void i9xx_submit_request(struct drm_i915_gem_request *request)
 
 	i915_gem_request_submit(request);
 
-	assert_ring_tail_valid(request->ring, request->tail);
-	I915_WRITE_TAIL(request->engine, request->tail);
+	I915_WRITE_TAIL(request->engine,
+			intel_ring_set_tail(request->ring, request->tail));
 }
 
 static void i9xx_emit_breadcrumb(struct drm_i915_gem_request *req, u32 *cs)
@@ -1316,11 +1316,23 @@ int intel_ring_pin(struct intel_ring *ring, unsigned int offset_bias)
 	return PTR_ERR(addr);
 }
 
+void intel_ring_reset(struct intel_ring *ring, u32 tail)
+{
+	GEM_BUG_ON(!list_empty(&ring->request_list));
+	ring->tail = tail;
+	ring->head = tail;
+	ring->emit = tail;
+	intel_ring_update_space(ring);
+}
+
 void intel_ring_unpin(struct intel_ring *ring)
 {
 	GEM_BUG_ON(!ring->vma);
 	GEM_BUG_ON(!ring->vaddr);
 
+	/* Discard any unused bytes beyond that submitted to hw. */
+	intel_ring_reset(ring, ring->tail);
+
 	if (i915_vma_is_map_and_fenceable(ring->vma))
 		i915_vma_unpin_iomap(ring->vma);
 	else
@@ -1562,8 +1574,9 @@ void intel_legacy_submission_resume(struct drm_i915_private *dev_priv)
 	struct intel_engine_cs *engine;
 	enum intel_engine_id id;
 
+	/* Restart from the beginning of the rings for convenience */
 	for_each_engine(engine, dev_priv, id)
-		engine->buffer->head = engine->buffer->tail;
+		intel_ring_reset(engine->buffer, 0);
 }
 
 static int ring_request_alloc(struct drm_i915_gem_request *request)
@@ -1616,7 +1629,7 @@ static int wait_for_space(struct drm_i915_gem_request *req, int bytes)
 		unsigned space;
 
 		/* Would completion of this request free enough space? */
-		space = __intel_ring_space(target->postfix, ring->tail,
+		space = __intel_ring_space(target->postfix, ring->emit,
 					   ring->size);
 		if (space >= bytes)
 			break;
@@ -1641,8 +1654,8 @@ static int wait_for_space(struct drm_i915_gem_request *req, int bytes)
 u32 *intel_ring_begin(struct drm_i915_gem_request *req, int num_dwords)
 {
 	struct intel_ring *ring = req->ring;
-	int remain_actual = ring->size - ring->tail;
-	int remain_usable = ring->effective_size - ring->tail;
+	int remain_actual = ring->size - ring->emit;
+	int remain_usable = ring->effective_size - ring->emit;
 	int bytes = num_dwords * sizeof(u32);
 	int total_bytes, wait_bytes;
 	bool need_wrap = false;
@@ -1678,17 +1691,17 @@ u32 *intel_ring_begin(struct drm_i915_gem_request *req, int num_dwords)
 
 	if (unlikely(need_wrap)) {
 		GEM_BUG_ON(remain_actual > ring->space);
-		GEM_BUG_ON(ring->tail + remain_actual > ring->size);
+		GEM_BUG_ON(ring->emit + remain_actual > ring->size);
 
 		/* Fill the tail with MI_NOOP */
-		memset(ring->vaddr + ring->tail, 0, remain_actual);
-		ring->tail = 0;
+		memset(ring->vaddr + ring->emit, 0, remain_actual);
+		ring->emit = 0;
 		ring->space -= remain_actual;
 	}
 
-	GEM_BUG_ON(ring->tail > ring->size - bytes);
-	cs = ring->vaddr + ring->tail;
-	ring->tail += bytes;
+	GEM_BUG_ON(ring->emit > ring->size - bytes);
+	cs = ring->vaddr + ring->emit;
+	ring->emit += bytes;
 	ring->space -= bytes;
 	GEM_BUG_ON(ring->space < 0);
 
@@ -1699,7 +1712,7 @@ u32 *intel_ring_begin(struct drm_i915_gem_request *req, int num_dwords)
 int intel_ring_cacheline_align(struct drm_i915_gem_request *req)
 {
 	int num_dwords =
-		(req->ring->tail & (CACHELINE_BYTES - 1)) / sizeof(uint32_t);
+		(req->ring->emit & (CACHELINE_BYTES - 1)) / sizeof(uint32_t);
 	u32 *cs;
 
 	if (num_dwords == 0)

drivers/gpu/drm/i915/intel_ringbuffer.h

@@ -145,6 +145,7 @@ struct intel_ring {
 
 	u32 head;
 	u32 tail;
+	u32 emit;
 
 	int space;
 	int size;
@@ -488,6 +489,8 @@ intel_write_status_page(struct intel_engine_cs *engine, int reg, u32 value)
 struct intel_ring *
 intel_engine_create_ring(struct intel_engine_cs *engine, int size);
 int intel_ring_pin(struct intel_ring *ring, unsigned int offset_bias);
+void intel_ring_reset(struct intel_ring *ring, u32 tail);
+void intel_ring_update_space(struct intel_ring *ring);
 void intel_ring_unpin(struct intel_ring *ring);
 void intel_ring_free(struct intel_ring *ring);
 
@@ -511,7 +514,7 @@ intel_ring_advance(struct drm_i915_gem_request *req, u32 *cs)
 	 * reserved for the command packet (i.e. the value passed to
 	 * intel_ring_begin()).
 	 */
-	GEM_BUG_ON((req->ring->vaddr + req->ring->tail) != cs);
+	GEM_BUG_ON((req->ring->vaddr + req->ring->emit) != cs);
 }
 
 static inline u32
@@ -540,7 +543,19 @@ assert_ring_tail_valid(const struct intel_ring *ring, unsigned int tail)
 	GEM_BUG_ON(tail >= ring->size);
 }
 
-void intel_ring_update_space(struct intel_ring *ring);
+static inline unsigned int
+intel_ring_set_tail(struct intel_ring *ring, unsigned int tail)
+{
+	/* Whilst writes to the tail are strictly order, there is no
+	 * serialisation between readers and the writers. The tail may be
+	 * read by i915_gem_request_retire() just as it is being updated
+	 * by execlists, as although the breadcrumb is complete, the context
+	 * switch hasn't been seen.
+	 */
+	assert_ring_tail_valid(ring, tail);
+	ring->tail = tail;
+	return tail;
+}
 
 void intel_engine_init_global_seqno(struct intel_engine_cs *engine, u32 seqno);