drm/i915: Only enforce fence limits inside the GTT.

So long as we adhere to the fence registers rules for alignment and no
overlaps (including with unfenced accesses to linear memory) and account
for the tiled access in our size allocation, we do not have to allocate
the full fenced region for the object. This allows us to fight the bloat
tiling imposed on pre-i965 chipsets and frees up RAM for real use. [Inside
the GTT we still suffer the additional alignment constraints, so it doesn't
magic allow us to render larger scenes without stalls -- we need the
expanded GTT and fence pipelining to overcome those...]
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

drivers/gpu/drm/i915/i915_debugfs.c

@@ -130,7 +130,8 @@ describe_obj(struct seq_file *m, struct drm_i915_gem_object *obj)
 	if (obj->fence_reg != I915_FENCE_REG_NONE)
 		seq_printf(m, " (fence: %d)", obj->fence_reg);
 	if (obj->gtt_space != NULL)
-		seq_printf(m, " (gtt_offset: %08x)", obj->gtt_offset);
+		seq_printf(m, " (gtt offset: %08x, size: %08x)",
+			   obj->gtt_offset, (unsigned int)obj->gtt_space->size);
 	if (obj->pin_mappable || obj->fault_mappable)
 		seq_printf(m, " (mappable)");
 	if (obj->ring != NULL)

drivers/gpu/drm/i915/i915_dma.c

@@ -770,6 +770,9 @@ static int i915_getparam(struct drm_device *dev, void *data,
 	case I915_PARAM_HAS_BLT:
 		value = HAS_BLT(dev);
 		break;
+	case I915_PARAM_HAS_RELAXED_FENCING:
+		value = 1;
+		break;
 	default:
 		DRM_DEBUG_DRIVER("Unknown parameter %d\n",
 				 param->param);

drivers/gpu/drm/i915/i915_drv.h

@@ -746,6 +746,8 @@ struct drm_i915_gem_object {
 	 * Advice: are the backing pages purgeable?
 	 */
 	unsigned int madv : 2;
+	unsigned int fenceable : 1;
+	unsigned int mappable : 1;
 
 	/**
 	 * Current tiling mode for the object.
@@ -1005,7 +1007,7 @@ struct drm_gem_object * i915_gem_alloc_object(struct drm_device *dev,
 					      size_t size);
 void i915_gem_free_object(struct drm_gem_object *obj);
 int i915_gem_object_pin(struct drm_gem_object *obj, uint32_t alignment,
-			bool mappable);
+			bool mappable, bool need_fence);
 void i915_gem_object_unpin(struct drm_gem_object *obj);
 int i915_gem_object_unbind(struct drm_gem_object *obj);
 void i915_gem_release_mmap(struct drm_gem_object *obj);
@@ -1068,10 +1070,6 @@ int i915_gem_evict_inactive(struct drm_device *dev);
 void i915_gem_detect_bit_6_swizzle(struct drm_device *dev);
 void i915_gem_object_do_bit_17_swizzle(struct drm_gem_object *obj);
 void i915_gem_object_save_bit_17_swizzle(struct drm_gem_object *obj);
-bool i915_tiling_ok(struct drm_device *dev, int stride, int size,
-		    int tiling_mode);
-bool i915_gem_object_fence_offset_ok(struct drm_gem_object *obj,
-				     int tiling_mode);
 
 /* i915_gem_debug.c */
 void i915_gem_dump_object(struct drm_gem_object *obj, int len,

drivers/gpu/drm/i915/i915_gem.c

@@ -36,7 +36,8 @@
 #include <linux/pci.h>
 #include <linux/intel-gtt.h>
 
-static uint32_t i915_gem_get_gtt_alignment(struct drm_gem_object *obj);
+static uint32_t i915_gem_get_gtt_alignment(struct drm_i915_gem_object *obj_priv);
+static uint32_t i915_gem_get_gtt_size(struct drm_i915_gem_object *obj_priv);
 
 static int i915_gem_object_flush_gpu_write_domain(struct drm_gem_object *obj,
 						  bool pipelined);
@@ -51,7 +52,9 @@ static void i915_gem_object_set_to_full_cpu_read_domain(struct drm_gem_object *o
 static int i915_gem_object_wait_rendering(struct drm_gem_object *obj,
 					  bool interruptible);
 static int i915_gem_object_bind_to_gtt(struct drm_gem_object *obj,
-				       unsigned alignment, bool mappable);
+				       unsigned alignment,
+				       bool mappable,
+				       bool need_fence);
 static void i915_gem_clear_fence_reg(struct drm_gem_object *obj);
 static int i915_gem_phys_pwrite(struct drm_device *dev, struct drm_gem_object *obj,
 				struct drm_i915_gem_pwrite *args,
@@ -79,30 +82,26 @@ static void i915_gem_info_remove_obj(struct drm_i915_private *dev_priv,
 }
 
 static void i915_gem_info_add_gtt(struct drm_i915_private *dev_priv,
-				  struct drm_gem_object *obj)
+				  struct drm_i915_gem_object *obj)
 {
-	struct drm_i915_gem_object *obj_priv = to_intel_bo(obj);
 	dev_priv->mm.gtt_count++;
-	dev_priv->mm.gtt_memory += obj->size;
-	if (obj_priv->gtt_offset < dev_priv->mm.gtt_mappable_end) {
+	dev_priv->mm.gtt_memory += obj->gtt_space->size;
+	if (obj->gtt_offset < dev_priv->mm.gtt_mappable_end) {
 		dev_priv->mm.mappable_gtt_used +=
-			min_t(size_t, obj->size,
-			      dev_priv->mm.gtt_mappable_end
-					- obj_priv->gtt_offset);
+			min_t(size_t, obj->gtt_space->size,
+			      dev_priv->mm.gtt_mappable_end - obj->gtt_offset);
 	}
 }
 
 static void i915_gem_info_remove_gtt(struct drm_i915_private *dev_priv,
-				     struct drm_gem_object *obj)
+				     struct drm_i915_gem_object *obj)
 {
-	struct drm_i915_gem_object *obj_priv = to_intel_bo(obj);
 	dev_priv->mm.gtt_count--;
-	dev_priv->mm.gtt_memory -= obj->size;
-	if (obj_priv->gtt_offset < dev_priv->mm.gtt_mappable_end) {
+	dev_priv->mm.gtt_memory -= obj->gtt_space->size;
+	if (obj->gtt_offset < dev_priv->mm.gtt_mappable_end) {
 		dev_priv->mm.mappable_gtt_used -=
-			min_t(size_t, obj->size,
-			      dev_priv->mm.gtt_mappable_end
-					- obj_priv->gtt_offset);
+			min_t(size_t, obj->gtt_space->size,
+			      dev_priv->mm.gtt_mappable_end - obj->gtt_offset);
 	}
 }
 
@@ -113,47 +112,43 @@ static void i915_gem_info_remove_gtt(struct drm_i915_private *dev_priv,
  */
 static void
 i915_gem_info_update_mappable(struct drm_i915_private *dev_priv,
-			      struct drm_gem_object *obj,
+			      struct drm_i915_gem_object *obj,
 			      bool mappable)
 {
-	struct drm_i915_gem_object *obj_priv = to_intel_bo(obj);
-
 	if (mappable) {
-		if (obj_priv->pin_mappable && obj_priv->fault_mappable)
+		if (obj->pin_mappable && obj->fault_mappable)
 			/* Combined state was already mappable. */
 			return;
 		dev_priv->mm.gtt_mappable_count++;
-		dev_priv->mm.gtt_mappable_memory += obj->size;
+		dev_priv->mm.gtt_mappable_memory += obj->gtt_space->size;
 	} else {
-		if (obj_priv->pin_mappable || obj_priv->fault_mappable)
+		if (obj->pin_mappable || obj->fault_mappable)
 			/* Combined state still mappable. */
 			return;
 		dev_priv->mm.gtt_mappable_count--;
-		dev_priv->mm.gtt_mappable_memory -= obj->size;
+		dev_priv->mm.gtt_mappable_memory -= obj->gtt_space->size;
 	}
 }
 
 static void i915_gem_info_add_pin(struct drm_i915_private *dev_priv,
-				  struct drm_gem_object *obj,
+				  struct drm_i915_gem_object *obj,
 				  bool mappable)
 {
-	struct drm_i915_gem_object *obj_priv = to_intel_bo(obj);
 	dev_priv->mm.pin_count++;
-	dev_priv->mm.pin_memory += obj->size;
+	dev_priv->mm.pin_memory += obj->gtt_space->size;
 	if (mappable) {
-		obj_priv->pin_mappable = true;
+		obj->pin_mappable = true;
 		i915_gem_info_update_mappable(dev_priv, obj, true);
 	}
 }
 
 static void i915_gem_info_remove_pin(struct drm_i915_private *dev_priv,
-				     struct drm_gem_object *obj)
+				     struct drm_i915_gem_object *obj)
 {
-	struct drm_i915_gem_object *obj_priv = to_intel_bo(obj);
 	dev_priv->mm.pin_count--;
-	dev_priv->mm.pin_memory -= obj->size;
-	if (obj_priv->pin_mappable) {
-		obj_priv->pin_mappable = false;
+	dev_priv->mm.pin_memory -= obj->gtt_space->size;
+	if (obj->pin_mappable) {
+		obj->pin_mappable = false;
 		i915_gem_info_update_mappable(dev_priv, obj, false);
 	}
 }
@@ -309,16 +304,6 @@ i915_gem_create_ioctl(struct drm_device *dev, void *data,
 	return 0;
 }
 
-static bool
-i915_gem_object_cpu_accessible(struct drm_i915_gem_object *obj)
-{
-	struct drm_device *dev = obj->base.dev;
-	drm_i915_private_t *dev_priv = dev->dev_private;
-
-	return obj->gtt_space == NULL ||
-		obj->gtt_offset + obj->base.size <= dev_priv->mm.gtt_mappable_end;
-}
-
 static int i915_gem_object_needs_bit17_swizzle(struct drm_gem_object *obj)
 {
 	drm_i915_private_t *dev_priv = obj->dev->dev_private;
@@ -1083,7 +1068,7 @@ i915_gem_pwrite_ioctl(struct drm_device *dev, void *data,
 	else if (obj_priv->tiling_mode == I915_TILING_NONE &&
 		 obj_priv->gtt_space &&
 		 obj->write_domain != I915_GEM_DOMAIN_CPU) {
-		ret = i915_gem_object_pin(obj, 0, true);
+		ret = i915_gem_object_pin(obj, 0, true, false);
 		if (ret)
 			goto out;
 
@@ -1307,11 +1292,19 @@ int i915_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 	/* Now bind it into the GTT if needed */
 	mutex_lock(&dev->struct_mutex);
 	BUG_ON(obj_priv->pin_count && !obj_priv->pin_mappable);
-	if (!i915_gem_object_cpu_accessible(obj_priv))
-		i915_gem_object_unbind(obj);
+
+	if (obj_priv->gtt_space) {
+		if (!obj_priv->mappable ||
+		    (obj_priv->tiling_mode && !obj_priv->fenceable)) {
+			ret = i915_gem_object_unbind(obj);
+			if (ret)
+				goto unlock;
+		}
+	}
 
 	if (!obj_priv->gtt_space) {
-		ret = i915_gem_object_bind_to_gtt(obj, 0, true);
+		ret = i915_gem_object_bind_to_gtt(obj, 0,
+						  true, obj_priv->tiling_mode);
 		if (ret)
 			goto unlock;
 	}
@@ -1322,7 +1315,7 @@ int i915_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 
 	if (!obj_priv->fault_mappable) {
 		obj_priv->fault_mappable = true;
-		i915_gem_info_update_mappable(dev_priv, obj, true);
+		i915_gem_info_update_mappable(dev_priv, obj_priv, true);
 	}
 
 	/* Need a new fence register? */
@@ -1448,7 +1441,7 @@ i915_gem_release_mmap(struct drm_gem_object *obj)
 
 	if (obj_priv->fault_mappable) {
 		obj_priv->fault_mappable = false;
-		i915_gem_info_update_mappable(dev_priv, obj, false);
+		i915_gem_info_update_mappable(dev_priv, obj_priv, false);
 	}
 }
 
@@ -1473,32 +1466,51 @@ i915_gem_free_mmap_offset(struct drm_gem_object *obj)
  * potential fence register mapping if needed.
  */
 static uint32_t
-i915_gem_get_gtt_alignment(struct drm_gem_object *obj)
+i915_gem_get_gtt_alignment(struct drm_i915_gem_object *obj_priv)
 {
-	struct drm_device *dev = obj->dev;
-	struct drm_i915_gem_object *obj_priv = to_intel_bo(obj);
-	int start, i;
+	struct drm_device *dev = obj_priv->base.dev;
 
 	/*
 	 * Minimum alignment is 4k (GTT page size), but might be greater
 	 * if a fence register is needed for the object.
 	 */
-	if (INTEL_INFO(dev)->gen >= 4 || obj_priv->tiling_mode == I915_TILING_NONE)
+	if (INTEL_INFO(dev)->gen >= 4 ||
+	    obj_priv->tiling_mode == I915_TILING_NONE)
 		return 4096;
 
+	/*
+	 * Previous chips need to be aligned to the size of the smallest
+	 * fence register that can contain the object.
+	 */
+	return i915_gem_get_gtt_size(obj_priv);
+}
+
+static uint32_t
+i915_gem_get_gtt_size(struct drm_i915_gem_object *obj_priv)
+{
+	struct drm_device *dev = obj_priv->base.dev;
+	uint32_t size;
+
+	/*
+	 * Minimum alignment is 4k (GTT page size), but might be greater
+	 * if a fence register is needed for the object.
+	 */
+	if (INTEL_INFO(dev)->gen >= 4)
+		return obj_priv->base.size;
+
 	/*
 	 * Previous chips need to be aligned to the size of the smallest
 	 * fence register that can contain the object.
 	 */
 	if (INTEL_INFO(dev)->gen == 3)
-		start = 1024*1024;
+		size = 1024*1024;
 	else
-		start = 512*1024;
+		size = 512*1024;
 
-	for (i = start; i < obj->size; i <<= 1)
-		;
+	while (size < obj_priv->base.size)
+		size <<= 1;
 
-	return i;
+	return size;
 }
 
 /**
@@ -2253,8 +2265,10 @@ i915_gem_object_unbind(struct drm_gem_object *obj)
 
 	i915_gem_object_put_pages_gtt(obj);
 
-	i915_gem_info_remove_gtt(dev_priv, obj);
+	i915_gem_info_remove_gtt(dev_priv, obj_priv);
 	list_del_init(&obj_priv->mm_list);
+	obj_priv->fenceable = true;
+	obj_priv->mappable = true;
 
 	drm_mm_put_block(obj_priv->gtt_space);
 	obj_priv->gtt_space = NULL;
@@ -2311,16 +2325,16 @@ i915_gpu_idle(struct drm_device *dev)
 	return 0;
 }
 
-static void sandybridge_write_fence_reg(struct drm_i915_fence_reg *reg)
+static void sandybridge_write_fence_reg(struct drm_gem_object *obj)
 {
-	struct drm_gem_object *obj = reg->obj;
 	struct drm_device *dev = obj->dev;
 	drm_i915_private_t *dev_priv = dev->dev_private;
 	struct drm_i915_gem_object *obj_priv = to_intel_bo(obj);
+	u32 size = i915_gem_get_gtt_size(obj_priv);
 	int regnum = obj_priv->fence_reg;
 	uint64_t val;
 
-	val = (uint64_t)((obj_priv->gtt_offset + obj->size - 4096) &
+	val = (uint64_t)((obj_priv->gtt_offset + size - 4096) &
 		    0xfffff000) << 32;
 	val |= obj_priv->gtt_offset & 0xfffff000;
 	val |= (uint64_t)((obj_priv->stride / 128) - 1) <<
@@ -2333,16 +2347,16 @@ static void sandybridge_write_fence_reg(struct drm_i915_fence_reg *reg)
 	I915_WRITE64(FENCE_REG_SANDYBRIDGE_0 + (regnum * 8), val);
 }
 
-static void i965_write_fence_reg(struct drm_i915_fence_reg *reg)
+static void i965_write_fence_reg(struct drm_gem_object *obj)
 {
-	struct drm_gem_object *obj = reg->obj;
 	struct drm_device *dev = obj->dev;
 	drm_i915_private_t *dev_priv = dev->dev_private;
 	struct drm_i915_gem_object *obj_priv = to_intel_bo(obj);
+	u32 size = i915_gem_get_gtt_size(obj_priv);
 	int regnum = obj_priv->fence_reg;
 	uint64_t val;
 
-	val = (uint64_t)((obj_priv->gtt_offset + obj->size - 4096) &
+	val = (uint64_t)((obj_priv->gtt_offset + size - 4096) &
 		    0xfffff000) << 32;
 	val |= obj_priv->gtt_offset & 0xfffff000;
 	val |= ((obj_priv->stride / 128) - 1) << I965_FENCE_PITCH_SHIFT;
@@ -2353,21 +2367,20 @@ static void i965_write_fence_reg(struct drm_i915_fence_reg *reg)
 	I915_WRITE64(FENCE_REG_965_0 + (regnum * 8), val);
 }
 
-static void i915_write_fence_reg(struct drm_i915_fence_reg *reg)
+static void i915_write_fence_reg(struct drm_gem_object *obj)
 {
-	struct drm_gem_object *obj = reg->obj;
 	struct drm_device *dev = obj->dev;
 	drm_i915_private_t *dev_priv = dev->dev_private;
 	struct drm_i915_gem_object *obj_priv = to_intel_bo(obj);
-	int regnum = obj_priv->fence_reg;
+	u32 size = i915_gem_get_gtt_size(obj_priv);
+	uint32_t fence_reg, val, pitch_val;
 	int tile_width;
-	uint32_t fence_reg, val;
-	uint32_t pitch_val;
 
 	if ((obj_priv->gtt_offset & ~I915_FENCE_START_MASK) ||
-	    (obj_priv->gtt_offset & (obj->size - 1))) {
-		WARN(1, "%s: object 0x%08x not 1M or size (0x%zx) aligned\n",
-		     __func__, obj_priv->gtt_offset, obj->size);
+	    (obj_priv->gtt_offset & (size - 1))) {
+		WARN(1, "%s: object 0x%08x [fenceable? %d] not 1M or size (0x%08x) aligned [gtt_space offset=%lx, size=%lx]\n",
+		     __func__, obj_priv->gtt_offset, obj_priv->fenceable, size,
+		     obj_priv->gtt_space->start, obj_priv->gtt_space->size);
 		return;
 	}
 
@@ -2390,23 +2403,24 @@ static void i915_write_fence_reg(struct drm_i915_fence_reg *reg)
 	val = obj_priv->gtt_offset;
 	if (obj_priv->tiling_mode == I915_TILING_Y)
 		val |= 1 << I830_FENCE_TILING_Y_SHIFT;
-	val |= I915_FENCE_SIZE_BITS(obj->size);
+	val |= I915_FENCE_SIZE_BITS(size);
 	val |= pitch_val << I830_FENCE_PITCH_SHIFT;
 	val |= I830_FENCE_REG_VALID;
 
-	if (regnum < 8)
-		fence_reg = FENCE_REG_830_0 + (regnum * 4);
+	fence_reg = obj_priv->fence_reg;
+	if (fence_reg < 8)
+		fence_reg = FENCE_REG_830_0 + fence_reg * 4;
 	else
-		fence_reg = FENCE_REG_945_8 + ((regnum - 8) * 4);
+		fence_reg = FENCE_REG_945_8 + (fence_reg - 8) * 4;
 	I915_WRITE(fence_reg, val);
 }
 
-static void i830_write_fence_reg(struct drm_i915_fence_reg *reg)
+static void i830_write_fence_reg(struct drm_gem_object *obj)
 {
-	struct drm_gem_object *obj = reg->obj;
 	struct drm_device *dev = obj->dev;
 	drm_i915_private_t *dev_priv = dev->dev_private;
 	struct drm_i915_gem_object *obj_priv = to_intel_bo(obj);
+	u32 size = i915_gem_get_gtt_size(obj_priv);
 	int regnum = obj_priv->fence_reg;
 	uint32_t val;
 	uint32_t pitch_val;
@@ -2426,7 +2440,7 @@ static void i830_write_fence_reg(struct drm_i915_fence_reg *reg)
 	val = obj_priv->gtt_offset;
 	if (obj_priv->tiling_mode == I915_TILING_Y)
 		val |= 1 << I830_FENCE_TILING_Y_SHIFT;
-	fence_size_bits = I830_FENCE_SIZE_BITS(obj->size);
+	fence_size_bits = I830_FENCE_SIZE_BITS(size);
 	WARN_ON(fence_size_bits & ~0x00000f00);
 	val |= fence_size_bits;
 	val |= pitch_val << I830_FENCE_PITCH_SHIFT;
@@ -2438,10 +2452,9 @@ static void i830_write_fence_reg(struct drm_i915_fence_reg *reg)
 static int i915_find_fence_reg(struct drm_device *dev,
 			       bool interruptible)
 {
-	struct drm_i915_fence_reg *reg = NULL;
-	struct drm_i915_gem_object *obj_priv = NULL;
 	struct drm_i915_private *dev_priv = dev->dev_private;
-	struct drm_gem_object *obj = NULL;
+	struct drm_i915_fence_reg *reg;
+	struct drm_i915_gem_object *obj_priv = NULL;
 	int i, avail, ret;
 
 	/* First try to find a free reg */
@@ -2460,33 +2473,31 @@ static int i915_find_fence_reg(struct drm_device *dev,
 		return -ENOSPC;
 
 	/* None available, try to steal one or wait for a user to finish */
-	i = I915_FENCE_REG_NONE;
+	avail = I915_FENCE_REG_NONE;
 	list_for_each_entry(reg, &dev_priv->mm.fence_list,
 			    lru_list) {
-		obj = reg->obj;
-		obj_priv = to_intel_bo(obj);
-
+		obj_priv = to_intel_bo(reg->obj);
 		if (obj_priv->pin_count)
 			continue;
 
 		/* found one! */
-		i = obj_priv->fence_reg;
+		avail = obj_priv->fence_reg;
 		break;
 	}
 
-	BUG_ON(i == I915_FENCE_REG_NONE);
+	BUG_ON(avail == I915_FENCE_REG_NONE);
 
 	/* We only have a reference on obj from the active list. put_fence_reg
 	 * might drop that one, causing a use-after-free in it. So hold a
 	 * private reference to obj like the other callers of put_fence_reg
 	 * (set_tiling ioctl) do. */
-	drm_gem_object_reference(obj);
-	ret = i915_gem_object_put_fence_reg(obj, interruptible);
-	drm_gem_object_unreference(obj);
+	drm_gem_object_reference(&obj_priv->base);
+	ret = i915_gem_object_put_fence_reg(&obj_priv->base, interruptible);
+	drm_gem_object_unreference(&obj_priv->base);
 	if (ret != 0)
 		return ret;
 
-	return i;
+	return avail;
 }
 
 /**
@@ -2551,21 +2562,22 @@ i915_gem_object_get_fence_reg(struct drm_gem_object *obj,
 
 	switch (INTEL_INFO(dev)->gen) {
 	case 6:
-		sandybridge_write_fence_reg(reg);
+		sandybridge_write_fence_reg(obj);
 		break;
 	case 5:
 	case 4:
-		i965_write_fence_reg(reg);
+		i965_write_fence_reg(obj);
 		break;
 	case 3:
-		i915_write_fence_reg(reg);
+		i915_write_fence_reg(obj);
 		break;
 	case 2:
-		i830_write_fence_reg(reg);
+		i830_write_fence_reg(obj);
 		break;
 	}
 
-	trace_i915_gem_object_get_fence(obj, obj_priv->fence_reg,
+	trace_i915_gem_object_get_fence(obj,
+					obj_priv->fence_reg,
 					obj_priv->tiling_mode);
 
 	return 0;
@@ -2671,13 +2683,15 @@ i915_gem_object_put_fence_reg(struct drm_gem_object *obj,
 static int
 i915_gem_object_bind_to_gtt(struct drm_gem_object *obj,
 			    unsigned alignment,
-			    bool mappable)
+			    bool mappable,
+			    bool need_fence)
 {
 	struct drm_device *dev = obj->dev;
 	drm_i915_private_t *dev_priv = dev->dev_private;
 	struct drm_i915_gem_object *obj_priv = to_intel_bo(obj);
 	struct drm_mm_node *free_space;
 	gfp_t gfpmask = __GFP_NORETRY | __GFP_NOWARN;
+	u32 size, fence_size, fence_alignment;
 	int ret;
 
 	if (obj_priv->madv != I915_MADV_WILLNEED) {
@@ -2685,13 +2699,18 @@ i915_gem_object_bind_to_gtt(struct drm_gem_object *obj,
 		return -EINVAL;
 	}
 
+	fence_size = i915_gem_get_gtt_size(obj_priv);
+	fence_alignment = i915_gem_get_gtt_alignment(obj_priv);
+
 	if (alignment == 0)
-		alignment = i915_gem_get_gtt_alignment(obj);
-	if (alignment & (i915_gem_get_gtt_alignment(obj) - 1)) {
+		alignment = need_fence ? fence_alignment : 4096;
+	if (need_fence && alignment & (fence_alignment - 1)) {
 		DRM_ERROR("Invalid object alignment requested %u\n", alignment);
 		return -EINVAL;
 	}
 
+	size = need_fence ? fence_size : obj->size;
+
 	/* If the object is bigger than the entire aperture, reject it early
 	 * before evicting everything in a vain attempt to find space.
 	 */
@@ -2705,32 +2724,29 @@ i915_gem_object_bind_to_gtt(struct drm_gem_object *obj,
 	if (mappable)
 		free_space =
 			drm_mm_search_free_in_range(&dev_priv->mm.gtt_space,
-						    obj->size, alignment, 0,
+						    size, alignment, 0,
 						    dev_priv->mm.gtt_mappable_end,
 						    0);
 	else
 		free_space = drm_mm_search_free(&dev_priv->mm.gtt_space,
-						obj->size, alignment, 0);
+						size, alignment, 0);
 
 	if (free_space != NULL) {
 		if (mappable)
 			obj_priv->gtt_space =
 				drm_mm_get_block_range_generic(free_space,
-							       obj->size,
-							       alignment, 0,
+							       size, alignment, 0,
 							       dev_priv->mm.gtt_mappable_end,
 							       0);
 		else
 			obj_priv->gtt_space =
-				drm_mm_get_block(free_space, obj->size,
-						 alignment);
+				drm_mm_get_block(free_space, size, alignment);
 	}
 	if (obj_priv->gtt_space == NULL) {
 		/* If the gtt is empty and we're still having trouble
 		 * fitting our object in, we're out of memory.
 		 */
-		ret = i915_gem_evict_something(dev, obj->size, alignment,
-					       mappable);
+		ret = i915_gem_evict_something(dev, size, alignment, mappable);
 		if (ret)
 			return ret;
 
@@ -2744,7 +2760,7 @@ i915_gem_object_bind_to_gtt(struct drm_gem_object *obj,
 
 		if (ret == -ENOMEM) {
 			/* first try to clear up some space from the GTT */
-			ret = i915_gem_evict_something(dev, obj->size,
+			ret = i915_gem_evict_something(dev, size,
 						       alignment, mappable);
 			if (ret) {
 				/* now try to shrink everyone else */
@@ -2775,8 +2791,8 @@ i915_gem_object_bind_to_gtt(struct drm_gem_object *obj,
 		drm_mm_put_block(obj_priv->gtt_space);
 		obj_priv->gtt_space = NULL;
 
-		ret = i915_gem_evict_something(dev, obj->size, alignment,
-					       mappable);
+		ret = i915_gem_evict_something(dev, size,
+					       alignment, mappable);
 		if (ret)
 			return ret;
 
@@ -2787,7 +2803,7 @@ i915_gem_object_bind_to_gtt(struct drm_gem_object *obj,
 
 	/* keep track of bounds object by adding it to the inactive list */
 	list_add_tail(&obj_priv->mm_list, &dev_priv->mm.inactive_list);
-	i915_gem_info_add_gtt(dev_priv, obj);
+	i915_gem_info_add_gtt(dev_priv, obj_priv);
 
 	/* 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
@@ -2798,6 +2814,13 @@ i915_gem_object_bind_to_gtt(struct drm_gem_object *obj,
 
 	trace_i915_gem_object_bind(obj, obj_priv->gtt_offset, mappable);
 
+	obj_priv->fenceable =
+		obj_priv->gtt_space->size == fence_size &&
+		(obj_priv->gtt_space->start & (fence_alignment -1)) == 0;
+
+	obj_priv->mappable =
+		obj_priv->gtt_offset + obj->size <= dev_priv->mm.gtt_mappable_end;
+
 	return 0;
 }
 
@@ -3516,9 +3539,8 @@ i915_gem_execbuffer_pin(struct drm_device *dev,
 				entry->relocation_count ? true : need_fence;
 
 			/* Check fence reg constraints and rebind if necessary */
-			if (need_fence &&
-			    !i915_gem_object_fence_offset_ok(&obj->base,
-							     obj->tiling_mode)) {
+			if ((need_fence && !obj->fenceable) ||
+			    (need_mappable && !obj->mappable)) {
 				ret = i915_gem_object_unbind(&obj->base);
 				if (ret)
 					break;
@@ -3526,7 +3548,8 @@ i915_gem_execbuffer_pin(struct drm_device *dev,
 
 			ret = i915_gem_object_pin(&obj->base,
 						  entry->alignment,
-						  need_mappable);
+						  need_mappable,
+						  need_fence);
 			if (ret)
 				break;
 
@@ -4097,7 +4120,7 @@ i915_gem_execbuffer2(struct drm_device *dev, void *data,
 
 int
 i915_gem_object_pin(struct drm_gem_object *obj, uint32_t alignment,
-		    bool mappable)
+		    bool mappable, bool need_fence)
 {
 	struct drm_device *dev = obj->dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -4108,14 +4131,15 @@ i915_gem_object_pin(struct drm_gem_object *obj, uint32_t alignment,
 	WARN_ON(i915_verify_lists(dev));
 
 	if (obj_priv->gtt_space != NULL) {
-		if (alignment == 0)
-			alignment = i915_gem_get_gtt_alignment(obj);
-		if (obj_priv->gtt_offset & (alignment - 1) ||
-		    (mappable && !i915_gem_object_cpu_accessible(obj_priv))) {
+		if ((alignment && obj_priv->gtt_offset & (alignment - 1)) ||
+		    (need_fence && !obj_priv->fenceable) ||
+		    (mappable && !obj_priv->mappable)) {
 			WARN(obj_priv->pin_count,
 			     "bo is already pinned with incorrect alignment:"
-			     " offset=%x, req.alignment=%x\n",
-			     obj_priv->gtt_offset, alignment);
+			     " offset=%x, req.alignment=%x, need_fence=%d, fenceable=%d, mappable=%d, cpu_accessible=%d\n",
+			     obj_priv->gtt_offset, alignment,
+			     need_fence, obj_priv->fenceable,
+			     mappable, obj_priv->mappable);
 			ret = i915_gem_object_unbind(obj);
 			if (ret)
 				return ret;
@@ -4123,13 +4147,14 @@ i915_gem_object_pin(struct drm_gem_object *obj, uint32_t alignment,
 	}
 
 	if (obj_priv->gtt_space == NULL) {
-		ret = i915_gem_object_bind_to_gtt(obj, alignment, mappable);
+		ret = i915_gem_object_bind_to_gtt(obj, alignment,
+						  mappable, need_fence);
 		if (ret)
 			return ret;
 	}
 
 	if (obj_priv->pin_count++ == 0) {
-		i915_gem_info_add_pin(dev_priv, obj, mappable);
+		i915_gem_info_add_pin(dev_priv, obj_priv, mappable);
 		if (!obj_priv->active)
 			list_move_tail(&obj_priv->mm_list,
 				       &dev_priv->mm.pinned_list);
@@ -4155,7 +4180,7 @@ i915_gem_object_unpin(struct drm_gem_object *obj)
 		if (!obj_priv->active)
 			list_move_tail(&obj_priv->mm_list,
 				       &dev_priv->mm.inactive_list);
-		i915_gem_info_remove_pin(dev_priv, obj);
+		i915_gem_info_remove_pin(dev_priv, obj_priv);
 	}
 	WARN_ON(i915_verify_lists(dev));
 }
@@ -4196,7 +4221,8 @@ i915_gem_pin_ioctl(struct drm_device *dev, void *data,
 	obj_priv->user_pin_count++;
 	obj_priv->pin_filp = file_priv;
 	if (obj_priv->user_pin_count == 1) {
-		ret = i915_gem_object_pin(obj, args->alignment, true);
+		ret = i915_gem_object_pin(obj, args->alignment,
+					  true, obj_priv->tiling_mode);
 		if (ret)
 			goto out;
 	}
@@ -4389,6 +4415,8 @@ struct drm_gem_object * i915_gem_alloc_object(struct drm_device *dev,
 	INIT_LIST_HEAD(&obj->ring_list);
 	INIT_LIST_HEAD(&obj->gpu_write_list);
 	obj->madv = I915_MADV_WILLNEED;
+	obj->fenceable = true;
+	obj->mappable = true;
 
 	return &obj->base;
 }
@@ -4508,7 +4536,7 @@ i915_gem_init_pipe_control(struct drm_device *dev)
 	obj_priv = to_intel_bo(obj);
 	obj_priv->agp_type = AGP_USER_CACHED_MEMORY;
 
-	ret = i915_gem_object_pin(obj, 4096, true);
+	ret = i915_gem_object_pin(obj, 4096, true, false);
 	if (ret)
 		goto err_unref;
 

drivers/gpu/drm/i915/i915_gem_tiling.c

@@ -181,7 +181,7 @@ i915_gem_detect_bit_6_swizzle(struct drm_device *dev)
 }
 
 /* Check pitch constriants for all chips & tiling formats */
-bool
+static bool
 i915_tiling_ok(struct drm_device *dev, int stride, int size, int tiling_mode)
 {
 	int tile_width;
@@ -232,25 +232,35 @@ i915_tiling_ok(struct drm_device *dev, int stride, int size, int tiling_mode)
 	return true;
 }
 
-bool
-i915_gem_object_fence_offset_ok(struct drm_gem_object *obj, int tiling_mode)
+/* Is the current GTT allocation valid for the change in tiling? */
+static bool
+i915_gem_object_fence_ok(struct drm_gem_object *obj, int tiling_mode)
 {
-	struct drm_device *dev = obj->dev;
 	struct drm_i915_gem_object *obj_priv = to_intel_bo(obj);
-
-	if (obj_priv->gtt_space == NULL)
-		return true;
+	u32 size;
 
 	if (tiling_mode == I915_TILING_NONE)
 		return true;
 
-	if (INTEL_INFO(dev)->gen >= 4)
+	if (INTEL_INFO(obj->dev)->gen >= 4)
 		return true;
 
-	if (obj_priv->gtt_offset & (obj->size - 1))
+	/*
+	 * Previous chips need to be aligned to the size of the smallest
+	 * fence register that can contain the object.
+	 */
+	if (INTEL_INFO(obj->dev)->gen == 3)
+		size = 1024*1024;
+	else
+		size = 512*1024;
+
+	while (size < obj_priv->base.size)
+		size <<= 1;
+
+	if (obj_priv->gtt_offset & (size - 1))
 		return false;
 
-	if (IS_GEN3(dev)) {
+	if (INTEL_INFO(obj->dev)->gen == 3) {
 		if (obj_priv->gtt_offset & ~I915_FENCE_START_MASK)
 			return false;
 	} else {
@@ -331,7 +341,7 @@ i915_gem_set_tiling(struct drm_device *dev, void *data,
 		 * tiling mode. Otherwise we can just leave it alone, but
 		 * need to ensure that any fence register is cleared.
 		 */
-		if (!i915_gem_object_fence_offset_ok(obj, args->tiling_mode))
+		if (!i915_gem_object_fence_ok(obj, args->tiling_mode))
 			ret = i915_gem_object_unbind(obj);
 		else if (obj_priv->fence_reg != I915_FENCE_REG_NONE)
 			ret = i915_gem_object_put_fence_reg(obj, true);

drivers/gpu/drm/i915/intel_display.c

@@ -1461,7 +1461,8 @@ intel_pin_and_fence_fb_obj(struct drm_device *dev,
 		BUG();
 	}
 
-	ret = i915_gem_object_pin(obj, alignment, true);
+	ret = i915_gem_object_pin(obj, alignment,
+				  !pipelined, obj_priv->tiling_mode);
 	if (ret)
 		return ret;
 
@@ -4353,7 +4354,7 @@ static int intel_crtc_cursor_set(struct drm_crtc *crtc,
 	/* we only need to pin inside GTT if cursor is non-phy */
 	mutex_lock(&dev->struct_mutex);
 	if (!dev_priv->info->cursor_needs_physical) {
-		ret = i915_gem_object_pin(bo, PAGE_SIZE, true);
+		ret = i915_gem_object_pin(bo, PAGE_SIZE, true, false);
 		if (ret) {
 			DRM_ERROR("failed to pin cursor bo\n");
 			goto fail_locked;
@@ -5517,7 +5518,7 @@ intel_alloc_context_page(struct drm_device *dev)
 	}
 
 	mutex_lock(&dev->struct_mutex);
-	ret = i915_gem_object_pin(ctx, 4096, true);
+	ret = i915_gem_object_pin(ctx, 4096, false, false);
 	if (ret) {
 		DRM_ERROR("failed to pin power context: %d\n", ret);
 		goto err_unref;

drivers/gpu/drm/i915/intel_overlay.c

@@ -781,7 +781,7 @@ static int intel_overlay_do_put_image(struct intel_overlay *overlay,
 	if (ret != 0)
 		return ret;
 
-	ret = i915_gem_object_pin(new_bo, PAGE_SIZE, true);
+	ret = i915_gem_object_pin(new_bo, PAGE_SIZE, false, false);
 	if (ret != 0)
 		return ret;
 
@@ -1423,7 +1423,7 @@ void intel_setup_overlay(struct drm_device *dev)
                 }
 		overlay->flip_addr = overlay->reg_bo->phys_obj->handle->busaddr;
 	} else {
-		ret = i915_gem_object_pin(reg_bo, PAGE_SIZE, true);
+		ret = i915_gem_object_pin(reg_bo, PAGE_SIZE, true, false);
 		if (ret) {
                         DRM_ERROR("failed to pin overlay register bo\n");
                         goto out_free_bo;

drivers/gpu/drm/i915/intel_ringbuffer.c

@@ -547,7 +547,7 @@ static int init_status_page(struct intel_ring_buffer *ring)
 	obj_priv = to_intel_bo(obj);
 	obj_priv->agp_type = AGP_USER_CACHED_MEMORY;
 
-	ret = i915_gem_object_pin(obj, 4096, true);
+	ret = i915_gem_object_pin(obj, 4096, true, false);
 	if (ret != 0) {
 		goto err_unref;
 	}
@@ -603,7 +603,7 @@ int intel_init_ring_buffer(struct drm_device *dev,
 
 	ring->gem_object = obj;
 
-	ret = i915_gem_object_pin(obj, PAGE_SIZE, true);
+	ret = i915_gem_object_pin(obj, PAGE_SIZE, true, false);
 	if (ret)
 		goto err_unref;
 

include/drm/i915_drm.h

@@ -287,6 +287,7 @@ typedef struct drm_i915_irq_wait {
 #define I915_PARAM_HAS_EXECBUF2          9
 #define I915_PARAM_HAS_BSD		 10
 #define I915_PARAM_HAS_BLT		 11
+#define I915_PARAM_HAS_RELAXED_FENCING	 12
 
 typedef struct drm_i915_getparam {
 	int param;