Initial import

1 files changed, 1780 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
new file mode 100644
index 000000000..a3190e793
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -0,0 +1,1780 @@
+/*
+ * Copyright © 2008,2010 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ * Authors:
+ *    Eric Anholt <eric@anholt.net>
+ *    Chris Wilson <chris@chris-wilson.co.uk>
+ *
+ */
+
+#include <drm/drmP.h>
+#include <drm/i915_drm.h>
+#include "i915_drv.h"
+#include "i915_trace.h"
+#include "intel_drv.h"
+#include <linux/dma_remapping.h>
+
+#define  __EXEC_OBJECT_HAS_PIN (1<<31)
+#define  __EXEC_OBJECT_HAS_FENCE (1<<30)
+#define  __EXEC_OBJECT_NEEDS_MAP (1<<29)
+#define  __EXEC_OBJECT_NEEDS_BIAS (1<<28)
+#define  __EXEC_OBJECT_PURGEABLE (1<<27)
+
+#define BATCH_OFFSET_BIAS (256*1024)
+
+struct eb_vmas {
+	struct list_head vmas;
+	int and;
+	union {
+		struct i915_vma *lut[0];
+		struct hlist_head buckets[0];
+	};
+};
+
+static struct eb_vmas *
+eb_create(struct drm_i915_gem_execbuffer2 *args)
+{
+	struct eb_vmas *eb = NULL;
+
+	if (args->flags & I915_EXEC_HANDLE_LUT) {
+		unsigned size = args->buffer_count;
+		size *= sizeof(struct i915_vma *);
+		size += sizeof(struct eb_vmas);
+		eb = kmalloc(size, GFP_TEMPORARY | __GFP_NOWARN | __GFP_NORETRY);
+	}
+
+	if (eb == NULL) {
+		unsigned size = args->buffer_count;
+		unsigned count = PAGE_SIZE / sizeof(struct hlist_head) / 2;
+		BUILD_BUG_ON_NOT_POWER_OF_2(PAGE_SIZE / sizeof(struct hlist_head));
+		while (count > 2*size)
+			count >>= 1;
+		eb = kzalloc(count*sizeof(struct hlist_head) +
+			     sizeof(struct eb_vmas),
+			     GFP_TEMPORARY);
+		if (eb == NULL)
+			return eb;
+
+		eb->and = count - 1;
+	} else
+		eb->and = -args->buffer_count;
+
+	INIT_LIST_HEAD(&eb->vmas);
+	return eb;
+}
+
+static void
+eb_reset(struct eb_vmas *eb)
+{
+	if (eb->and >= 0)
+		memset(eb->buckets, 0, (eb->and+1)*sizeof(struct hlist_head));
+}
+
+static int
+eb_lookup_vmas(struct eb_vmas *eb,
+	       struct drm_i915_gem_exec_object2 *exec,
+	       const struct drm_i915_gem_execbuffer2 *args,
+	       struct i915_address_space *vm,
+	       struct drm_file *file)
+{
+	struct drm_i915_gem_object *obj;
+	struct list_head objects;
+	int i, ret;
+
+	INIT_LIST_HEAD(&objects);
+	spin_lock(&file->table_lock);
+	/* Grab a reference to the object and release the lock so we can lookup
+	 * or create the VMA without using GFP_ATOMIC */
+	for (i = 0; i < args->buffer_count; i++) {
+		obj = to_intel_bo(idr_find(&file->object_idr, exec[i].handle));
+		if (obj == NULL) {
+			spin_unlock(&file->table_lock);
+			DRM_DEBUG("Invalid object handle %d at index %d\n",
+				   exec[i].handle, i);
+			ret = -ENOENT;
+			goto err;
+		}
+
+		if (!list_empty(&obj->obj_exec_link)) {
+			spin_unlock(&file->table_lock);
+			DRM_DEBUG("Object %p [handle %d, index %d] appears more than once in object list\n",
+				   obj, exec[i].handle, i);
+			ret = -EINVAL;
+			goto err;
+		}
+
+		drm_gem_object_reference(&obj->base);
+		list_add_tail(&obj->obj_exec_link, &objects);
+	}
+	spin_unlock(&file->table_lock);
+
+	i = 0;
+	while (!list_empty(&objects)) {
+		struct i915_vma *vma;
+
+		obj = list_first_entry(&objects,
+				       struct drm_i915_gem_object,
+				       obj_exec_link);
+
+		/*
+		 * NOTE: We can leak any vmas created here when something fails
+		 * later on. But that's no issue since vma_unbind can deal with
+		 * vmas which are not actually bound. And since only
+		 * lookup_or_create exists as an interface to get at the vma
+		 * from the (obj, vm) we don't run the risk of creating
+		 * duplicated vmas for the same vm.
+		 */
+		vma = i915_gem_obj_lookup_or_create_vma(obj, vm);
+		if (IS_ERR(vma)) {
+			DRM_DEBUG("Failed to lookup VMA\n");
+			ret = PTR_ERR(vma);
+			goto err;
+		}
+
+		/* Transfer ownership from the objects list to the vmas list. */
+		list_add_tail(&vma->exec_list, &eb->vmas);
+		list_del_init(&obj->obj_exec_link);
+
+		vma->exec_entry = &exec[i];
+		if (eb->and < 0) {
+			eb->lut[i] = vma;
+		} else {
+			uint32_t handle = args->flags & I915_EXEC_HANDLE_LUT ? i : exec[i].handle;
+			vma->exec_handle = handle;
+			hlist_add_head(&vma->exec_node,
+				       &eb->buckets[handle & eb->and]);
+		}
+		++i;
+	}
+
+	return 0;
+
+
+err:
+	while (!list_empty(&objects)) {
+		obj = list_first_entry(&objects,
+				       struct drm_i915_gem_object,
+				       obj_exec_link);
+		list_del_init(&obj->obj_exec_link);
+		drm_gem_object_unreference(&obj->base);
+	}
+	/*
+	 * Objects already transfered to the vmas list will be unreferenced by
+	 * eb_destroy.
+	 */
+
+	return ret;
+}
+
+static struct i915_vma *eb_get_vma(struct eb_vmas *eb, unsigned long handle)
+{
+	if (eb->and < 0) {
+		if (handle >= -eb->and)
+			return NULL;
+		return eb->lut[handle];
+	} else {
+		struct hlist_head *head;
+		struct hlist_node *node;
+
+		head = &eb->buckets[handle & eb->and];
+		hlist_for_each(node, head) {
+			struct i915_vma *vma;
+
+			vma = hlist_entry(node, struct i915_vma, exec_node);
+			if (vma->exec_handle == handle)
+				return vma;
+		}
+		return NULL;
+	}
+}
+
+static void
+i915_gem_execbuffer_unreserve_vma(struct i915_vma *vma)
+{
+	struct drm_i915_gem_exec_object2 *entry;
+	struct drm_i915_gem_object *obj = vma->obj;
+
+	if (!drm_mm_node_allocated(&vma->node))
+		return;
+
+	entry = vma->exec_entry;
+
+	if (entry->flags & __EXEC_OBJECT_HAS_FENCE)
+		i915_gem_object_unpin_fence(obj);
+
+	if (entry->flags & __EXEC_OBJECT_HAS_PIN)
+		vma->pin_count--;
+
+	if (entry->flags & __EXEC_OBJECT_PURGEABLE)
+		obj->madv = I915_MADV_DONTNEED;
+
+	entry->flags &= ~(__EXEC_OBJECT_HAS_FENCE |
+			  __EXEC_OBJECT_HAS_PIN |
+			  __EXEC_OBJECT_PURGEABLE);
+}
+
+static void eb_destroy(struct eb_vmas *eb)
+{
+	while (!list_empty(&eb->vmas)) {
+		struct i915_vma *vma;
+
+		vma = list_first_entry(&eb->vmas,
+				       struct i915_vma,
+				       exec_list);
+		list_del_init(&vma->exec_list);
+		i915_gem_execbuffer_unreserve_vma(vma);
+		drm_gem_object_unreference(&vma->obj->base);
+	}
+	kfree(eb);
+}
+
+static inline int use_cpu_reloc(struct drm_i915_gem_object *obj)
+{
+	return (HAS_LLC(obj->base.dev) ||
+		obj->base.write_domain == I915_GEM_DOMAIN_CPU ||
+		obj->cache_level != I915_CACHE_NONE);
+}
+
+static int
+relocate_entry_cpu(struct drm_i915_gem_object *obj,
+		   struct drm_i915_gem_relocation_entry *reloc,
+		   uint64_t target_offset)
+{
+	struct drm_device *dev = obj->base.dev;
+	uint32_t page_offset = offset_in_page(reloc->offset);
+	uint64_t delta = reloc->delta + target_offset;
+	char *vaddr;
+	int ret;
+
+	ret = i915_gem_object_set_to_cpu_domain(obj, true);
+	if (ret)
+		return ret;
+
+	vaddr = kmap_atomic(i915_gem_object_get_page(obj,
+				reloc->offset >> PAGE_SHIFT));
+	*(uint32_t *)(vaddr + page_offset) = lower_32_bits(delta);
+
+	if (INTEL_INFO(dev)->gen >= 8) {
+		page_offset = offset_in_page(page_offset + sizeof(uint32_t));
+
+		if (page_offset == 0) {
+			kunmap_atomic(vaddr);
+			vaddr = kmap_atomic(i915_gem_object_get_page(obj,
+			    (reloc->offset + sizeof(uint32_t)) >> PAGE_SHIFT));
+		}
+
+		*(uint32_t *)(vaddr + page_offset) = upper_32_bits(delta);
+	}
+
+	kunmap_atomic(vaddr);
+
+	return 0;
+}
+
+static int
+relocate_entry_gtt(struct drm_i915_gem_object *obj,
+		   struct drm_i915_gem_relocation_entry *reloc,
+		   uint64_t target_offset)
+{
+	struct drm_device *dev = obj->base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	uint64_t delta = reloc->delta + target_offset;
+	uint64_t offset;
+	void __iomem *reloc_page;
+	int ret;
+
+	ret = i915_gem_object_set_to_gtt_domain(obj, true);
+	if (ret)
+		return ret;
+
+	ret = i915_gem_object_put_fence(obj);
+	if (ret)
+		return ret;
+
+	/* Map the page containing the relocation we're going to perform.  */
+	offset = i915_gem_obj_ggtt_offset(obj);
+	offset += reloc->offset;
+	reloc_page = io_mapping_map_atomic_wc(dev_priv->gtt.mappable,
+					      offset & PAGE_MASK);
+	iowrite32(lower_32_bits(delta), reloc_page + offset_in_page(offset));
+
+	if (INTEL_INFO(dev)->gen >= 8) {
+		offset += sizeof(uint32_t);
+
+		if (offset_in_page(offset) == 0) {
+			io_mapping_unmap_atomic(reloc_page);
+			reloc_page =
+				io_mapping_map_atomic_wc(dev_priv->gtt.mappable,
+							 offset);
+		}
+
+		iowrite32(upper_32_bits(delta),
+			  reloc_page + offset_in_page(offset));
+	}
+
+	io_mapping_unmap_atomic(reloc_page);
+
+	return 0;
+}
+
+static void
+clflush_write32(void *addr, uint32_t value)
+{
+	/* This is not a fast path, so KISS. */
+	drm_clflush_virt_range(addr, sizeof(uint32_t));
+	*(uint32_t *)addr = value;
+	drm_clflush_virt_range(addr, sizeof(uint32_t));
+}
+
+static int
+relocate_entry_clflush(struct drm_i915_gem_object *obj,
+		       struct drm_i915_gem_relocation_entry *reloc,
+		       uint64_t target_offset)
+{
+	struct drm_device *dev = obj->base.dev;
+	uint32_t page_offset = offset_in_page(reloc->offset);
+	uint64_t delta = (int)reloc->delta + target_offset;
+	char *vaddr;
+	int ret;
+
+	ret = i915_gem_object_set_to_gtt_domain(obj, true);
+	if (ret)
+		return ret;
+
+	vaddr = kmap_atomic(i915_gem_object_get_page(obj,
+				reloc->offset >> PAGE_SHIFT));
+	clflush_write32(vaddr + page_offset, lower_32_bits(delta));
+
+	if (INTEL_INFO(dev)->gen >= 8) {
+		page_offset = offset_in_page(page_offset + sizeof(uint32_t));
+
+		if (page_offset == 0) {
+			kunmap_atomic(vaddr);
+			vaddr = kmap_atomic(i915_gem_object_get_page(obj,
+			    (reloc->offset + sizeof(uint32_t)) >> PAGE_SHIFT));
+		}
+
+		clflush_write32(vaddr + page_offset, upper_32_bits(delta));
+	}
+
+	kunmap_atomic(vaddr);
+
+	return 0;
+}
+
+static int
+i915_gem_execbuffer_relocate_entry(struct drm_i915_gem_object *obj,
+				   struct eb_vmas *eb,
+				   struct drm_i915_gem_relocation_entry *reloc)
+{
+	struct drm_device *dev = obj->base.dev;
+	struct drm_gem_object *target_obj;
+	struct drm_i915_gem_object *target_i915_obj;
+	struct i915_vma *target_vma;
+	uint64_t target_offset;
+	int ret;
+
+	/* we've already hold a reference to all valid objects */
+	target_vma = eb_get_vma(eb, reloc->target_handle);
+	if (unlikely(target_vma == NULL))
+		return -ENOENT;
+	target_i915_obj = target_vma->obj;
+	target_obj = &target_vma->obj->base;
+
+	target_offset = target_vma->node.start;
+
+	/* Sandybridge PPGTT errata: We need a global gtt mapping for MI and
+	 * pipe_control writes because the gpu doesn't properly redirect them
+	 * through the ppgtt for non_secure batchbuffers. */
+	if (unlikely(IS_GEN6(dev) &&
+	    reloc->write_domain == I915_GEM_DOMAIN_INSTRUCTION &&
+	    !(target_vma->bound & GLOBAL_BIND))) {
+		ret = i915_vma_bind(target_vma, target_i915_obj->cache_level,
+				    GLOBAL_BIND);
+		if (WARN_ONCE(ret, "Unexpected failure to bind target VMA!"))
+			return ret;
+	}
+
+	/* Validate that the target is in a valid r/w GPU domain */
+	if (unlikely(reloc->write_domain & (reloc->write_domain - 1))) {
+		DRM_DEBUG("reloc with multiple write domains: "
+			  "obj %p target %d offset %d "
+			  "read %08x write %08x",
+			  obj, reloc->target_handle,
+			  (int) reloc->offset,
+			  reloc->read_domains,
+			  reloc->write_domain);
+		return -EINVAL;
+	}
+	if (unlikely((reloc->write_domain | reloc->read_domains)
+		     & ~I915_GEM_GPU_DOMAINS)) {
+		DRM_DEBUG("reloc with read/write non-GPU domains: "
+			  "obj %p target %d offset %d "
+			  "read %08x write %08x",
+			  obj, reloc->target_handle,
+			  (int) reloc->offset,
+			  reloc->read_domains,
+			  reloc->write_domain);
+		return -EINVAL;
+	}
+
+	target_obj->pending_read_domains |= reloc->read_domains;
+	target_obj->pending_write_domain |= reloc->write_domain;
+
+	/* If the relocation already has the right value in it, no
+	 * more work needs to be done.
+	 */
+	if (target_offset == reloc->presumed_offset)
+		return 0;
+
+	/* Check that the relocation address is valid... */
+	if (unlikely(reloc->offset >
+		obj->base.size - (INTEL_INFO(dev)->gen >= 8 ? 8 : 4))) {
+		DRM_DEBUG("Relocation beyond object bounds: "
+			  "obj %p target %d offset %d size %d.\n",
+			  obj, reloc->target_handle,
+			  (int) reloc->offset,
+			  (int) obj->base.size);
+		return -EINVAL;
+	}
+	if (unlikely(reloc->offset & 3)) {
+		DRM_DEBUG("Relocation not 4-byte aligned: "
+			  "obj %p target %d offset %d.\n",
+			  obj, reloc->target_handle,
+			  (int) reloc->offset);
+		return -EINVAL;
+	}
+
+	/* We can't wait for rendering with pagefaults disabled */
+	if (obj->active && in_atomic())
+		return -EFAULT;
+
+	if (use_cpu_reloc(obj))
+		ret = relocate_entry_cpu(obj, reloc, target_offset);
+	else if (obj->map_and_fenceable)
+		ret = relocate_entry_gtt(obj, reloc, target_offset);
+	else if (cpu_has_clflush)
+		ret = relocate_entry_clflush(obj, reloc, target_offset);
+	else {
+		WARN_ONCE(1, "Impossible case in relocation handling\n");
+		ret = -ENODEV;
+	}
+
+	if (ret)
+		return ret;
+
+	/* and update the user's relocation entry */
+	reloc->presumed_offset = target_offset;
+
+	return 0;
+}
+
+static int
+i915_gem_execbuffer_relocate_vma(struct i915_vma *vma,
+				 struct eb_vmas *eb)
+{
+#define N_RELOC(x) ((x) / sizeof(struct drm_i915_gem_relocation_entry))
+	struct drm_i915_gem_relocation_entry stack_reloc[N_RELOC(512)];
+	struct drm_i915_gem_relocation_entry __user *user_relocs;
+	struct drm_i915_gem_exec_object2 *entry = vma->exec_entry;
+	int remain, ret;
+
+	user_relocs = to_user_ptr(entry->relocs_ptr);
+
+	remain = entry->relocation_count;
+	while (remain) {
+		struct drm_i915_gem_relocation_entry *r = stack_reloc;
+		int count = remain;
+		if (count > ARRAY_SIZE(stack_reloc))
+			count = ARRAY_SIZE(stack_reloc);
+		remain -= count;
+
+		if (__copy_from_user_inatomic(r, user_relocs, count*sizeof(r[0])))
+			return -EFAULT;
+
+		do {
+			u64 offset = r->presumed_offset;
+
+			ret = i915_gem_execbuffer_relocate_entry(vma->obj, eb, r);
+			if (ret)
+				return ret;
+
+			if (r->presumed_offset != offset &&
+			    __copy_to_user_inatomic(&user_relocs->presumed_offset,
+						    &r->presumed_offset,
+						    sizeof(r->presumed_offset))) {
+				return -EFAULT;
+			}
+
+			user_relocs++;
+			r++;
+		} while (--count);
+	}
+
+	return 0;
+#undef N_RELOC
+}
+
+static int
+i915_gem_execbuffer_relocate_vma_slow(struct i915_vma *vma,
+				      struct eb_vmas *eb,
+				      struct drm_i915_gem_relocation_entry *relocs)
+{
+	const struct drm_i915_gem_exec_object2 *entry = vma->exec_entry;
+	int i, ret;
+
+	for (i = 0; i < entry->relocation_count; i++) {
+		ret = i915_gem_execbuffer_relocate_entry(vma->obj, eb, &relocs[i]);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int
+i915_gem_execbuffer_relocate(struct eb_vmas *eb)
+{
+	struct i915_vma *vma;
+	int ret = 0;
+
+	/* This is the fast path and we cannot handle a pagefault whilst
+	 * holding the struct mutex lest the user pass in the relocations
+	 * contained within a mmaped bo. For in such a case we, the page
+	 * fault handler would call i915_gem_fault() and we would try to
+	 * acquire the struct mutex again. Obviously this is bad and so
+	 * lockdep complains vehemently.
+	 */
+	pagefault_disable();
+	list_for_each_entry(vma, &eb->vmas, exec_list) {
+		ret = i915_gem_execbuffer_relocate_vma(vma, eb);
+		if (ret)
+			break;
+	}
+	pagefault_enable();
+
+	return ret;
+}
+
+static bool only_mappable_for_reloc(unsigned int flags)
+{
+	return (flags & (EXEC_OBJECT_NEEDS_FENCE | __EXEC_OBJECT_NEEDS_MAP)) ==
+		__EXEC_OBJECT_NEEDS_MAP;
+}
+
+static int
+i915_gem_execbuffer_reserve_vma(struct i915_vma *vma,
+				struct intel_engine_cs *ring,
+				bool *need_reloc)
+{
+	struct drm_i915_gem_object *obj = vma->obj;
+	struct drm_i915_gem_exec_object2 *entry = vma->exec_entry;
+	uint64_t flags;
+	int ret;
+
+	flags = 0;
+	if (!drm_mm_node_allocated(&vma->node)) {
+		if (entry->flags & __EXEC_OBJECT_NEEDS_MAP)
+			flags |= PIN_GLOBAL | PIN_MAPPABLE;
+		if (entry->flags & EXEC_OBJECT_NEEDS_GTT)
+			flags |= PIN_GLOBAL;
+		if (entry->flags & __EXEC_OBJECT_NEEDS_BIAS)
+			flags |= BATCH_OFFSET_BIAS | PIN_OFFSET_BIAS;
+	}
+
+	ret = i915_gem_object_pin(obj, vma->vm, entry->alignment, flags);
+	if ((ret == -ENOSPC  || ret == -E2BIG) &&
+	    only_mappable_for_reloc(entry->flags))
+		ret = i915_gem_object_pin(obj, vma->vm,
+					  entry->alignment,
+					  flags & ~(PIN_GLOBAL | PIN_MAPPABLE));
+	if (ret)
+		return ret;
+
+	entry->flags |= __EXEC_OBJECT_HAS_PIN;
+
+	if (entry->flags & EXEC_OBJECT_NEEDS_FENCE) {
+		ret = i915_gem_object_get_fence(obj);
+		if (ret)
+			return ret;
+
+		if (i915_gem_object_pin_fence(obj))
+			entry->flags |= __EXEC_OBJECT_HAS_FENCE;
+	}
+
+	if (entry->offset != vma->node.start) {
+		entry->offset = vma->node.start;
+		*need_reloc = true;
+	}
+
+	if (entry->flags & EXEC_OBJECT_WRITE) {
+		obj->base.pending_read_domains = I915_GEM_DOMAIN_RENDER;
+		obj->base.pending_write_domain = I915_GEM_DOMAIN_RENDER;
+	}
+
+	return 0;
+}
+
+static bool
+need_reloc_mappable(struct i915_vma *vma)
+{
+	struct drm_i915_gem_exec_object2 *entry = vma->exec_entry;
+
+	if (entry->relocation_count == 0)
+		return false;
+
+	if (!i915_is_ggtt(vma->vm))
+		return false;
+
+	/* See also use_cpu_reloc() */
+	if (HAS_LLC(vma->obj->base.dev))
+		return false;
+
+	if (vma->obj->base.write_domain == I915_GEM_DOMAIN_CPU)
+		return false;
+
+	return true;
+}
+
+static bool
+eb_vma_misplaced(struct i915_vma *vma)
+{
+	struct drm_i915_gem_exec_object2 *entry = vma->exec_entry;
+	struct drm_i915_gem_object *obj = vma->obj;
+
+	WARN_ON(entry->flags & __EXEC_OBJECT_NEEDS_MAP &&
+	       !i915_is_ggtt(vma->vm));
+
+	if (entry->alignment &&
+	    vma->node.start & (entry->alignment - 1))
+		return true;
+
+	if (entry->flags & __EXEC_OBJECT_NEEDS_BIAS &&
+	    vma->node.start < BATCH_OFFSET_BIAS)
+		return true;
+
+	/* avoid costly ping-pong once a batch bo ended up non-mappable */
+	if (entry->flags & __EXEC_OBJECT_NEEDS_MAP && !obj->map_and_fenceable)
+		return !only_mappable_for_reloc(entry->flags);
+
+	return false;
+}
+
+static int
+i915_gem_execbuffer_reserve(struct intel_engine_cs *ring,
+			    struct list_head *vmas,
+			    bool *need_relocs)
+{
+	struct drm_i915_gem_object *obj;
+	struct i915_vma *vma;
+	struct i915_address_space *vm;
+	struct list_head ordered_vmas;
+	bool has_fenced_gpu_access = INTEL_INFO(ring->dev)->gen < 4;
+	int retry;
+
+	i915_gem_retire_requests_ring(ring);
+
+	vm = list_first_entry(vmas, struct i915_vma, exec_list)->vm;
+
+	INIT_LIST_HEAD(&ordered_vmas);
+	while (!list_empty(vmas)) {
+		struct drm_i915_gem_exec_object2 *entry;
+		bool need_fence, need_mappable;
+
+		vma = list_first_entry(vmas, struct i915_vma, exec_list);
+		obj = vma->obj;
+		entry = vma->exec_entry;
+
+		if (!has_fenced_gpu_access)
+			entry->flags &= ~EXEC_OBJECT_NEEDS_FENCE;
+		need_fence =
+			entry->flags & EXEC_OBJECT_NEEDS_FENCE &&
+			obj->tiling_mode != I915_TILING_NONE;
+		need_mappable = need_fence || need_reloc_mappable(vma);
+
+		if (need_mappable) {
+			entry->flags |= __EXEC_OBJECT_NEEDS_MAP;
+			list_move(&vma->exec_list, &ordered_vmas);
+		} else
+			list_move_tail(&vma->exec_list, &ordered_vmas);
+
+		obj->base.pending_read_domains = I915_GEM_GPU_DOMAINS & ~I915_GEM_DOMAIN_COMMAND;
+		obj->base.pending_write_domain = 0;
+	}
+	list_splice(&ordered_vmas, vmas);
+
+	/* Attempt to pin all of the buffers into the GTT.
+	 * This is done in 3 phases:
+	 *
+	 * 1a. Unbind all objects that do not match the GTT constraints for
+	 *     the execbuffer (fenceable, mappable, alignment etc).
+	 * 1b. Increment pin count for already bound objects.
+	 * 2.  Bind new objects.
+	 * 3.  Decrement pin count.
+	 *
+	 * This avoid unnecessary unbinding of later objects in order to make
+	 * room for the earlier objects *unless* we need to defragment.
+	 */
+	retry = 0;
+	do {
+		int ret = 0;
+
+		/* Unbind any ill-fitting objects or pin. */
+		list_for_each_entry(vma, vmas, exec_list) {
+			if (!drm_mm_node_allocated(&vma->node))
+				continue;
+
+			if (eb_vma_misplaced(vma))
+				ret = i915_vma_unbind(vma);
+			else
+				ret = i915_gem_execbuffer_reserve_vma(vma, ring, need_relocs);
+			if (ret)
+				goto err;
+		}
+
+		/* Bind fresh objects */
+		list_for_each_entry(vma, vmas, exec_list) {
+			if (drm_mm_node_allocated(&vma->node))
+				continue;
+
+			ret = i915_gem_execbuffer_reserve_vma(vma, ring, need_relocs);
+			if (ret)
+				goto err;
+		}
+
+err:
+		if (ret != -ENOSPC || retry++)
+			return ret;
+
+		/* Decrement pin count for bound objects */
+		list_for_each_entry(vma, vmas, exec_list)
+			i915_gem_execbuffer_unreserve_vma(vma);
+
+		ret = i915_gem_evict_vm(vm, true);
+		if (ret)
+			return ret;
+	} while (1);
+}
+
+static int
+i915_gem_execbuffer_relocate_slow(struct drm_device *dev,
+				  struct drm_i915_gem_execbuffer2 *args,
+				  struct drm_file *file,
+				  struct intel_engine_cs *ring,
+				  struct eb_vmas *eb,
+				  struct drm_i915_gem_exec_object2 *exec)
+{
+	struct drm_i915_gem_relocation_entry *reloc;
+	struct i915_address_space *vm;
+	struct i915_vma *vma;
+	bool need_relocs;
+	int *reloc_offset;
+	int i, total, ret;
+	unsigned count = args->buffer_count;
+
+	vm = list_first_entry(&eb->vmas, struct i915_vma, exec_list)->vm;
+
+	/* We may process another execbuffer during the unlock... */
+	while (!list_empty(&eb->vmas)) {
+		vma = list_first_entry(&eb->vmas, struct i915_vma, exec_list);
+		list_del_init(&vma->exec_list);
+		i915_gem_execbuffer_unreserve_vma(vma);
+		drm_gem_object_unreference(&vma->obj->base);
+	}
+
+	mutex_unlock(&dev->struct_mutex);
+
+	total = 0;
+	for (i = 0; i < count; i++)
+		total += exec[i].relocation_count;
+
+	reloc_offset = drm_malloc_ab(count, sizeof(*reloc_offset));
+	reloc = drm_malloc_ab(total, sizeof(*reloc));
+	if (reloc == NULL || reloc_offset == NULL) {
+		drm_free_large(reloc);
+		drm_free_large(reloc_offset);
+		mutex_lock(&dev->struct_mutex);
+		return -ENOMEM;
+	}
+
+	total = 0;
+	for (i = 0; i < count; i++) {
+		struct drm_i915_gem_relocation_entry __user *user_relocs;
+		u64 invalid_offset = (u64)-1;
+		int j;
+
+		user_relocs = to_user_ptr(exec[i].relocs_ptr);
+
+		if (copy_from_user(reloc+total, user_relocs,
+				   exec[i].relocation_count * sizeof(*reloc))) {
+			ret = -EFAULT;
+			mutex_lock(&dev->struct_mutex);
+			goto err;
+		}
+
+		/* As we do not update the known relocation offsets after
+		 * relocating (due to the complexities in lock handling),
+		 * we need to mark them as invalid now so that we force the
+		 * relocation processing next time. Just in case the target
+		 * object is evicted and then rebound into its old
+		 * presumed_offset before the next execbuffer - if that
+		 * happened we would make the mistake of assuming that the
+		 * relocations were valid.
+		 */
+		for (j = 0; j < exec[i].relocation_count; j++) {
+			if (__copy_to_user(&user_relocs[j].presumed_offset,
+					   &invalid_offset,
+					   sizeof(invalid_offset))) {
+				ret = -EFAULT;
+				mutex_lock(&dev->struct_mutex);
+				goto err;
+			}
+		}
+
+		reloc_offset[i] = total;
+		total += exec[i].relocation_count;
+	}
+
+	ret = i915_mutex_lock_interruptible(dev);
+	if (ret) {
+		mutex_lock(&dev->struct_mutex);
+		goto err;
+	}
+
+	/* reacquire the objects */
+	eb_reset(eb);
+	ret = eb_lookup_vmas(eb, exec, args, vm, file);
+	if (ret)
+		goto err;
+
+	need_relocs = (args->flags & I915_EXEC_NO_RELOC) == 0;
+	ret = i915_gem_execbuffer_reserve(ring, &eb->vmas, &need_relocs);
+	if (ret)
+		goto err;
+
+	list_for_each_entry(vma, &eb->vmas, exec_list) {
+		int offset = vma->exec_entry - exec;
+		ret = i915_gem_execbuffer_relocate_vma_slow(vma, eb,
+							    reloc + reloc_offset[offset]);
+		if (ret)
+			goto err;
+	}
+
+	/* Leave the user relocations as are, this is the painfully slow path,
+	 * and we want to avoid the complication of dropping the lock whilst
+	 * having buffers reserved in the aperture and so causing spurious
+	 * ENOSPC for random operations.
+	 */
+
+err:
+	drm_free_large(reloc);
+	drm_free_large(reloc_offset);
+	return ret;
+}
+
+static int
+i915_gem_execbuffer_move_to_gpu(struct intel_engine_cs *ring,
+				struct list_head *vmas)
+{
+	struct i915_vma *vma;
+	uint32_t flush_domains = 0;
+	bool flush_chipset = false;
+	int ret;
+
+	list_for_each_entry(vma, vmas, exec_list) {
+		struct drm_i915_gem_object *obj = vma->obj;
+		ret = i915_gem_object_sync(obj, ring);
+		if (ret)
+			return ret;
+
+		if (obj->base.write_domain & I915_GEM_DOMAIN_CPU)
+			flush_chipset |= i915_gem_clflush_object(obj, false);
+
+		flush_domains |= obj->base.write_domain;
+	}
+
+	if (flush_chipset)
+		i915_gem_chipset_flush(ring->dev);
+
+	if (flush_domains & I915_GEM_DOMAIN_GTT)
+		wmb();
+
+	/* Unconditionally invalidate gpu caches and ensure that we do flush
+	 * any residual writes from the previous batch.
+	 */
+	return intel_ring_invalidate_all_caches(ring);
+}
+
+static bool
+i915_gem_check_execbuffer(struct drm_i915_gem_execbuffer2 *exec)
+{
+	if (exec->flags & __I915_EXEC_UNKNOWN_FLAGS)
+		return false;
+
+	return ((exec->batch_start_offset | exec->batch_len) & 0x7) == 0;
+}
+
+static int
+validate_exec_list(struct drm_device *dev,
+		   struct drm_i915_gem_exec_object2 *exec,
+		   int count)
+{
+	unsigned relocs_total = 0;
+	unsigned relocs_max = UINT_MAX / sizeof(struct drm_i915_gem_relocation_entry);
+	unsigned invalid_flags;
+	int i;
+
+	invalid_flags = __EXEC_OBJECT_UNKNOWN_FLAGS;
+	if (USES_FULL_PPGTT(dev))
+		invalid_flags |= EXEC_OBJECT_NEEDS_GTT;
+
+	for (i = 0; i < count; i++) {
+		char __user *ptr = to_user_ptr(exec[i].relocs_ptr);
+		int length; /* limited by fault_in_pages_readable() */
+
+		if (exec[i].flags & invalid_flags)
+			return -EINVAL;
+
+		/* First check for malicious input causing overflow in
+		 * the worst case where we need to allocate the entire
+		 * relocation tree as a single array.
+		 */
+		if (exec[i].relocation_count > relocs_max - relocs_total)
+			return -EINVAL;
+		relocs_total += exec[i].relocation_count;
+
+		length = exec[i].relocation_count *
+			sizeof(struct drm_i915_gem_relocation_entry);
+		/*
+		 * We must check that the entire relocation array is safe
+		 * to read, but since we may need to update the presumed
+		 * offsets during execution, check for full write access.
+		 */
+		if (!access_ok(VERIFY_WRITE, ptr, length))
+			return -EFAULT;
+
+		if (likely(!i915.prefault_disable)) {
+			if (fault_in_multipages_readable(ptr, length))
+				return -EFAULT;
+		}
+	}
+
+	return 0;
+}
+
+static struct intel_context *
+i915_gem_validate_context(struct drm_device *dev, struct drm_file *file,
+			  struct intel_engine_cs *ring, const u32 ctx_id)
+{
+	struct intel_context *ctx = NULL;
+	struct i915_ctx_hang_stats *hs;
+
+	if (ring->id != RCS && ctx_id != DEFAULT_CONTEXT_HANDLE)
+		return ERR_PTR(-EINVAL);
+
+	ctx = i915_gem_context_get(file->driver_priv, ctx_id);
+	if (IS_ERR(ctx))
+		return ctx;
+
+	hs = &ctx->hang_stats;
+	if (hs->banned) {
+		DRM_DEBUG("Context %u tried to submit while banned\n", ctx_id);
+		return ERR_PTR(-EIO);
+	}
+
+	if (i915.enable_execlists && !ctx->engine[ring->id].state) {
+		int ret = intel_lr_context_deferred_create(ctx, ring);
+		if (ret) {
+			DRM_DEBUG("Could not create LRC %u: %d\n", ctx_id, ret);
+			return ERR_PTR(ret);
+		}
+	}
+
+	return ctx;
+}
+
+void
+i915_gem_execbuffer_move_to_active(struct list_head *vmas,
+				   struct intel_engine_cs *ring)
+{
+	struct drm_i915_gem_request *req = intel_ring_get_request(ring);
+	struct i915_vma *vma;
+
+	list_for_each_entry(vma, vmas, exec_list) {
+		struct drm_i915_gem_exec_object2 *entry = vma->exec_entry;
+		struct drm_i915_gem_object *obj = vma->obj;
+		u32 old_read = obj->base.read_domains;
+		u32 old_write = obj->base.write_domain;
+
+		obj->base.write_domain = obj->base.pending_write_domain;
+		if (obj->base.write_domain == 0)
+			obj->base.pending_read_domains |= obj->base.read_domains;
+		obj->base.read_domains = obj->base.pending_read_domains;
+
+		i915_vma_move_to_active(vma, ring);
+		if (obj->base.write_domain) {
+			obj->dirty = 1;
+			i915_gem_request_assign(&obj->last_write_req, req);
+
+			intel_fb_obj_invalidate(obj, ring, ORIGIN_CS);
+
+			/* update for the implicit flush after a batch */
+			obj->base.write_domain &= ~I915_GEM_GPU_DOMAINS;
+		}
+		if (entry->flags & EXEC_OBJECT_NEEDS_FENCE) {
+			i915_gem_request_assign(&obj->last_fenced_req, req);
+			if (entry->flags & __EXEC_OBJECT_HAS_FENCE) {
+				struct drm_i915_private *dev_priv = to_i915(ring->dev);
+				list_move_tail(&dev_priv->fence_regs[obj->fence_reg].lru_list,
+					       &dev_priv->mm.fence_list);
+			}
+		}
+
+		trace_i915_gem_object_change_domain(obj, old_read, old_write);
+	}
+}
+
+void
+i915_gem_execbuffer_retire_commands(struct drm_device *dev,
+				    struct drm_file *file,
+				    struct intel_engine_cs *ring,
+				    struct drm_i915_gem_object *obj)
+{
+	/* Unconditionally force add_request to emit a full flush. */
+	ring->gpu_caches_dirty = true;
+
+	/* Add a breadcrumb for the completion of the batch buffer */
+	(void)__i915_add_request(ring, file, obj);
+}
+
+static int
+i915_reset_gen7_sol_offsets(struct drm_device *dev,
+			    struct intel_engine_cs *ring)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	int ret, i;
+
+	if (!IS_GEN7(dev) || ring != &dev_priv->ring[RCS]) {
+		DRM_DEBUG("sol reset is gen7/rcs only\n");
+		return -EINVAL;
+	}
+
+	ret = intel_ring_begin(ring, 4 * 3);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < 4; i++) {
+		intel_ring_emit(ring, MI_LOAD_REGISTER_IMM(1));
+		intel_ring_emit(ring, GEN7_SO_WRITE_OFFSET(i));
+		intel_ring_emit(ring, 0);
+	}
+
+	intel_ring_advance(ring);
+
+	return 0;
+}
+
+static int
+i915_emit_box(struct intel_engine_cs *ring,
+	      struct drm_clip_rect *box,
+	      int DR1, int DR4)
+{
+	int ret;
+
+	if (box->y2 <= box->y1 || box->x2 <= box->x1 ||
+	    box->y2 <= 0 || box->x2 <= 0) {
+		DRM_ERROR("Bad box %d,%d..%d,%d\n",
+			  box->x1, box->y1, box->x2, box->y2);
+		return -EINVAL;
+	}
+
+	if (INTEL_INFO(ring->dev)->gen >= 4) {
+		ret = intel_ring_begin(ring, 4);
+		if (ret)
+			return ret;
+
+		intel_ring_emit(ring, GFX_OP_DRAWRECT_INFO_I965);
+		intel_ring_emit(ring, (box->x1 & 0xffff) | box->y1 << 16);
+		intel_ring_emit(ring, ((box->x2 - 1) & 0xffff) | (box->y2 - 1) << 16);
+		intel_ring_emit(ring, DR4);
+	} else {
+		ret = intel_ring_begin(ring, 6);
+		if (ret)
+			return ret;
+
+		intel_ring_emit(ring, GFX_OP_DRAWRECT_INFO);
+		intel_ring_emit(ring, DR1);
+		intel_ring_emit(ring, (box->x1 & 0xffff) | box->y1 << 16);
+		intel_ring_emit(ring, ((box->x2 - 1) & 0xffff) | (box->y2 - 1) << 16);
+		intel_ring_emit(ring, DR4);
+		intel_ring_emit(ring, 0);
+	}
+	intel_ring_advance(ring);
+
+	return 0;
+}
+
+static struct drm_i915_gem_object*
+i915_gem_execbuffer_parse(struct intel_engine_cs *ring,
+			  struct drm_i915_gem_exec_object2 *shadow_exec_entry,
+			  struct eb_vmas *eb,
+			  struct drm_i915_gem_object *batch_obj,
+			  u32 batch_start_offset,
+			  u32 batch_len,
+			  bool is_master)
+{
+	struct drm_i915_private *dev_priv = to_i915(batch_obj->base.dev);
+	struct drm_i915_gem_object *shadow_batch_obj;
+	struct i915_vma *vma;
+	int ret;
+
+	shadow_batch_obj = i915_gem_batch_pool_get(&dev_priv->mm.batch_pool,
+						   PAGE_ALIGN(batch_len));
+	if (IS_ERR(shadow_batch_obj))
+		return shadow_batch_obj;
+
+	ret = i915_parse_cmds(ring,
+			      batch_obj,
+			      shadow_batch_obj,
+			      batch_start_offset,
+			      batch_len,
+			      is_master);
+	if (ret)
+		goto err;
+
+	ret = i915_gem_obj_ggtt_pin(shadow_batch_obj, 0, 0);
+	if (ret)
+		goto err;
+
+	memset(shadow_exec_entry, 0, sizeof(*shadow_exec_entry));
+
+	vma = i915_gem_obj_to_ggtt(shadow_batch_obj);
+	vma->exec_entry = shadow_exec_entry;
+	vma->exec_entry->flags = __EXEC_OBJECT_PURGEABLE | __EXEC_OBJECT_HAS_PIN;
+	drm_gem_object_reference(&shadow_batch_obj->base);
+	list_add_tail(&vma->exec_list, &eb->vmas);
+
+	shadow_batch_obj->base.pending_read_domains = I915_GEM_DOMAIN_COMMAND;
+
+	return shadow_batch_obj;
+
+err:
+	if (ret == -EACCES) /* unhandled chained batch */
+		return batch_obj;
+	else
+		return ERR_PTR(ret);
+}
+
+int
+i915_gem_ringbuffer_submission(struct drm_device *dev, struct drm_file *file,
+			       struct intel_engine_cs *ring,
+			       struct intel_context *ctx,
+			       struct drm_i915_gem_execbuffer2 *args,
+			       struct list_head *vmas,
+			       struct drm_i915_gem_object *batch_obj,
+			       u64 exec_start, u32 dispatch_flags)
+{
+	struct drm_clip_rect *cliprects = NULL;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	u64 exec_len;
+	int instp_mode;
+	u32 instp_mask;
+	int i, ret = 0;
+
+	if (args->num_cliprects != 0) {
+		if (ring != &dev_priv->ring[RCS]) {
+			DRM_DEBUG("clip rectangles are only valid with the render ring\n");
+			return -EINVAL;
+		}
+
+		if (INTEL_INFO(dev)->gen >= 5) {
+			DRM_DEBUG("clip rectangles are only valid on pre-gen5\n");
+			return -EINVAL;
+		}
+
+		if (args->num_cliprects > UINT_MAX / sizeof(*cliprects)) {
+			DRM_DEBUG("execbuf with %u cliprects\n",
+				  args->num_cliprects);
+			return -EINVAL;
+		}
+
+		cliprects = kcalloc(args->num_cliprects,
+				    sizeof(*cliprects),
+				    GFP_KERNEL);
+		if (cliprects == NULL) {
+			ret = -ENOMEM;
+			goto error;
+		}
+
+		if (copy_from_user(cliprects,
+				   to_user_ptr(args->cliprects_ptr),
+				   sizeof(*cliprects)*args->num_cliprects)) {
+			ret = -EFAULT;
+			goto error;
+		}
+	} else {
+		if (args->DR4 == 0xffffffff) {
+			DRM_DEBUG("UXA submitting garbage DR4, fixing up\n");
+			args->DR4 = 0;
+		}
+
+		if (args->DR1 || args->DR4 || args->cliprects_ptr) {
+			DRM_DEBUG("0 cliprects but dirt in cliprects fields\n");
+			return -EINVAL;
+		}
+	}
+
+	ret = i915_gem_execbuffer_move_to_gpu(ring, vmas);
+	if (ret)
+		goto error;
+
+	ret = i915_switch_context(ring, ctx);
+	if (ret)
+		goto error;
+
+	if (ctx->ppgtt)
+		WARN(ctx->ppgtt->pd_dirty_rings & (1<<ring->id),
+			"%s didn't clear reload\n", ring->name);
+	else if (dev_priv->mm.aliasing_ppgtt)
+		WARN(dev_priv->mm.aliasing_ppgtt->pd_dirty_rings &
+			(1<<ring->id), "%s didn't clear reload\n", ring->name);
+
+	instp_mode = args->flags & I915_EXEC_CONSTANTS_MASK;
+	instp_mask = I915_EXEC_CONSTANTS_MASK;
+	switch (instp_mode) {
+	case I915_EXEC_CONSTANTS_REL_GENERAL:
+	case I915_EXEC_CONSTANTS_ABSOLUTE:
+	case I915_EXEC_CONSTANTS_REL_SURFACE:
+		if (instp_mode != 0 && ring != &dev_priv->ring[RCS]) {
+			DRM_DEBUG("non-0 rel constants mode on non-RCS\n");
+			ret = -EINVAL;
+			goto error;
+		}
+
+		if (instp_mode != dev_priv->relative_constants_mode) {
+			if (INTEL_INFO(dev)->gen < 4) {
+				DRM_DEBUG("no rel constants on pre-gen4\n");
+				ret = -EINVAL;
+				goto error;
+			}
+
+			if (INTEL_INFO(dev)->gen > 5 &&
+			    instp_mode == I915_EXEC_CONSTANTS_REL_SURFACE) {
+				DRM_DEBUG("rel surface constants mode invalid on gen5+\n");
+				ret = -EINVAL;
+				goto error;
+			}
+
+			/* The HW changed the meaning on this bit on gen6 */
+			if (INTEL_INFO(dev)->gen >= 6)
+				instp_mask &= ~I915_EXEC_CONSTANTS_REL_SURFACE;
+		}
+		break;
+	default:
+		DRM_DEBUG("execbuf with unknown constants: %d\n", instp_mode);
+		ret = -EINVAL;
+		goto error;
+	}
+
+	if (ring == &dev_priv->ring[RCS] &&
+			instp_mode != dev_priv->relative_constants_mode) {
+		ret = intel_ring_begin(ring, 4);
+		if (ret)
+			goto error;
+
+		intel_ring_emit(ring, MI_NOOP);
+		intel_ring_emit(ring, MI_LOAD_REGISTER_IMM(1));
+		intel_ring_emit(ring, INSTPM);
+		intel_ring_emit(ring, instp_mask << 16 | instp_mode);
+		intel_ring_advance(ring);
+
+		dev_priv->relative_constants_mode = instp_mode;
+	}
+
+	if (args->flags & I915_EXEC_GEN7_SOL_RESET) {
+		ret = i915_reset_gen7_sol_offsets(dev, ring);
+		if (ret)
+			goto error;
+	}
+
+	exec_len = args->batch_len;
+	if (cliprects) {
+		for (i = 0; i < args->num_cliprects; i++) {
+			ret = i915_emit_box(ring, &cliprects[i],
+					    args->DR1, args->DR4);
+			if (ret)
+				goto error;
+
+			ret = ring->dispatch_execbuffer(ring,
+							exec_start, exec_len,
+							dispatch_flags);
+			if (ret)
+				goto error;
+		}
+	} else {
+		ret = ring->dispatch_execbuffer(ring,
+						exec_start, exec_len,
+						dispatch_flags);
+		if (ret)
+			return ret;
+	}
+
+	trace_i915_gem_ring_dispatch(intel_ring_get_request(ring), dispatch_flags);
+
+	i915_gem_execbuffer_move_to_active(vmas, ring);
+	i915_gem_execbuffer_retire_commands(dev, file, ring, batch_obj);
+
+error:
+	kfree(cliprects);
+	return ret;
+}
+
+/**
+ * Find one BSD ring to dispatch the corresponding BSD command.
+ * The Ring ID is returned.
+ */
+static int gen8_dispatch_bsd_ring(struct drm_device *dev,
+				  struct drm_file *file)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct drm_i915_file_private *file_priv = file->driver_priv;
+
+	/* Check whether the file_priv is using one ring */
+	if (file_priv->bsd_ring)
+		return file_priv->bsd_ring->id;
+	else {
+		/* If no, use the ping-pong mechanism to select one ring */
+		int ring_id;
+
+		mutex_lock(&dev->struct_mutex);
+		if (dev_priv->mm.bsd_ring_dispatch_index == 0) {
+			ring_id = VCS;
+			dev_priv->mm.bsd_ring_dispatch_index = 1;
+		} else {
+			ring_id = VCS2;
+			dev_priv->mm.bsd_ring_dispatch_index = 0;
+		}
+		file_priv->bsd_ring = &dev_priv->ring[ring_id];
+		mutex_unlock(&dev->struct_mutex);
+		return ring_id;
+	}
+}
+
+static struct drm_i915_gem_object *
+eb_get_batch(struct eb_vmas *eb)
+{
+	struct i915_vma *vma = list_entry(eb->vmas.prev, typeof(*vma), exec_list);
+
+	/*
+	 * SNA is doing fancy tricks with compressing batch buffers, which leads
+	 * to negative relocation deltas. Usually that works out ok since the
+	 * relocate address is still positive, except when the batch is placed
+	 * very low in the GTT. Ensure this doesn't happen.
+	 *
+	 * Note that actual hangs have only been observed on gen7, but for
+	 * paranoia do it everywhere.
+	 */
+	vma->exec_entry->flags |= __EXEC_OBJECT_NEEDS_BIAS;
+
+	return vma->obj;
+}
+
+static int
+i915_gem_do_execbuffer(struct drm_device *dev, void *data,
+		       struct drm_file *file,
+		       struct drm_i915_gem_execbuffer2 *args,
+		       struct drm_i915_gem_exec_object2 *exec)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct eb_vmas *eb;
+	struct drm_i915_gem_object *batch_obj;
+	struct drm_i915_gem_exec_object2 shadow_exec_entry;
+	struct intel_engine_cs *ring;
+	struct intel_context *ctx;
+	struct i915_address_space *vm;
+	const u32 ctx_id = i915_execbuffer2_get_context_id(*args);
+	u64 exec_start = args->batch_start_offset;
+	u32 dispatch_flags;
+	int ret;
+	bool need_relocs;
+
+	if (!i915_gem_check_execbuffer(args))
+		return -EINVAL;
+
+	ret = validate_exec_list(dev, exec, args->buffer_count);
+	if (ret)
+		return ret;
+
+	dispatch_flags = 0;
+	if (args->flags & I915_EXEC_SECURE) {
+		if (!file->is_master || !capable(CAP_SYS_ADMIN))
+		    return -EPERM;
+
+		dispatch_flags |= I915_DISPATCH_SECURE;
+	}
+	if (args->flags & I915_EXEC_IS_PINNED)
+		dispatch_flags |= I915_DISPATCH_PINNED;
+
+	if ((args->flags & I915_EXEC_RING_MASK) > LAST_USER_RING) {
+		DRM_DEBUG("execbuf with unknown ring: %d\n",
+			  (int)(args->flags & I915_EXEC_RING_MASK));
+		return -EINVAL;
+	}
+
+	if (((args->flags & I915_EXEC_RING_MASK) != I915_EXEC_BSD) &&
+	    ((args->flags & I915_EXEC_BSD_MASK) != 0)) {
+		DRM_DEBUG("execbuf with non bsd ring but with invalid "
+			"bsd dispatch flags: %d\n", (int)(args->flags));
+		return -EINVAL;
+	} 
+
+	if ((args->flags & I915_EXEC_RING_MASK) == I915_EXEC_DEFAULT)
+		ring = &dev_priv->ring[RCS];
+	else if ((args->flags & I915_EXEC_RING_MASK) == I915_EXEC_BSD) {
+		if (HAS_BSD2(dev)) {
+			int ring_id;
+
+			switch (args->flags & I915_EXEC_BSD_MASK) {
+			case I915_EXEC_BSD_DEFAULT:
+				ring_id = gen8_dispatch_bsd_ring(dev, file);
+				ring = &dev_priv->ring[ring_id];
+				break;
+			case I915_EXEC_BSD_RING1:
+				ring = &dev_priv->ring[VCS];
+				break;
+			case I915_EXEC_BSD_RING2:
+				ring = &dev_priv->ring[VCS2];
+				break;
+			default:
+				DRM_DEBUG("execbuf with unknown bsd ring: %d\n",
+					  (int)(args->flags & I915_EXEC_BSD_MASK));
+				return -EINVAL;
+			}
+		} else
+			ring = &dev_priv->ring[VCS];
+	} else
+		ring = &dev_priv->ring[(args->flags & I915_EXEC_RING_MASK) - 1];
+
+	if (!intel_ring_initialized(ring)) {
+		DRM_DEBUG("execbuf with invalid ring: %d\n",
+			  (int)(args->flags & I915_EXEC_RING_MASK));
+		return -EINVAL;
+	}
+
+	if (args->buffer_count < 1) {
+		DRM_DEBUG("execbuf with %d buffers\n", args->buffer_count);
+		return -EINVAL;
+	}
+
+	intel_runtime_pm_get(dev_priv);
+
+	ret = i915_mutex_lock_interruptible(dev);
+	if (ret)
+		goto pre_mutex_err;
+
+	ctx = i915_gem_validate_context(dev, file, ring, ctx_id);
+	if (IS_ERR(ctx)) {
+		mutex_unlock(&dev->struct_mutex);
+		ret = PTR_ERR(ctx);
+		goto pre_mutex_err;
+	}
+
+	i915_gem_context_reference(ctx);
+
+	if (ctx->ppgtt)
+		vm = &ctx->ppgtt->base;
+	else
+		vm = &dev_priv->gtt.base;
+
+	eb = eb_create(args);
+	if (eb == NULL) {
+		i915_gem_context_unreference(ctx);
+		mutex_unlock(&dev->struct_mutex);
+		ret = -ENOMEM;
+		goto pre_mutex_err;
+	}
+
+	/* Look up object handles */
+	ret = eb_lookup_vmas(eb, exec, args, vm, file);
+	if (ret)
+		goto err;
+
+	/* take note of the batch buffer before we might reorder the lists */
+	batch_obj = eb_get_batch(eb);
+
+	/* Move the objects en-masse into the GTT, evicting if necessary. */
+	need_relocs = (args->flags & I915_EXEC_NO_RELOC) == 0;
+	ret = i915_gem_execbuffer_reserve(ring, &eb->vmas, &need_relocs);
+	if (ret)
+		goto err;
+
+	/* The objects are in their final locations, apply the relocations. */
+	if (need_relocs)
+		ret = i915_gem_execbuffer_relocate(eb);
+	if (ret) {
+		if (ret == -EFAULT) {
+			ret = i915_gem_execbuffer_relocate_slow(dev, args, file, ring,
+								eb, exec);
+			BUG_ON(!mutex_is_locked(&dev->struct_mutex));
+		}
+		if (ret)
+			goto err;
+	}
+
+	/* Set the pending read domains for the batch buffer to COMMAND */
+	if (batch_obj->base.pending_write_domain) {
+		DRM_DEBUG("Attempting to use self-modifying batch buffer\n");
+		ret = -EINVAL;
+		goto err;
+	}
+
+	if (i915_needs_cmd_parser(ring) && args->batch_len) {
+		batch_obj = i915_gem_execbuffer_parse(ring,
+						      &shadow_exec_entry,
+						      eb,
+						      batch_obj,
+						      args->batch_start_offset,
+						      args->batch_len,
+						      file->is_master);
+		if (IS_ERR(batch_obj)) {
+			ret = PTR_ERR(batch_obj);
+			goto err;
+		}
+
+		/*
+		 * Set the DISPATCH_SECURE bit to remove the NON_SECURE
+		 * bit from MI_BATCH_BUFFER_START commands issued in the
+		 * dispatch_execbuffer implementations. We specifically
+		 * don't want that set when the command parser is
+		 * enabled.
+		 *
+		 * FIXME: with aliasing ppgtt, buffers that should only
+		 * be in ggtt still end up in the aliasing ppgtt. remove
+		 * this check when that is fixed.
+		 */
+		if (USES_FULL_PPGTT(dev))
+			dispatch_flags |= I915_DISPATCH_SECURE;
+
+		exec_start = 0;
+	}
+
+	batch_obj->base.pending_read_domains |= I915_GEM_DOMAIN_COMMAND;
+
+	/* snb/ivb/vlv conflate the "batch in ppgtt" bit with the "non-secure
+	 * batch" bit. Hence we need to pin secure batches into the global gtt.
+	 * hsw should have this fixed, but bdw mucks it up again. */
+	if (dispatch_flags & I915_DISPATCH_SECURE) {
+		/*
+		 * So on first glance it looks freaky that we pin the batch here
+		 * outside of the reservation loop. But:
+		 * - The batch is already pinned into the relevant ppgtt, so we
+		 *   already have the backing storage fully allocated.
+		 * - No other BO uses the global gtt (well contexts, but meh),
+		 *   so we don't really have issues with multiple objects not
+		 *   fitting due to fragmentation.
+		 * So this is actually safe.
+		 */
+		ret = i915_gem_obj_ggtt_pin(batch_obj, 0, 0);
+		if (ret)
+			goto err;
+
+		exec_start += i915_gem_obj_ggtt_offset(batch_obj);
+	} else
+		exec_start += i915_gem_obj_offset(batch_obj, vm);
+
+	ret = dev_priv->gt.do_execbuf(dev, file, ring, ctx, args,
+				      &eb->vmas, batch_obj, exec_start,
+				      dispatch_flags);
+
+	/*
+	 * FIXME: We crucially rely upon the active tracking for the (ppgtt)
+	 * batch vma for correctness. For less ugly and less fragility this
+	 * needs to be adjusted to also track the ggtt batch vma properly as
+	 * active.
+	 */
+	if (dispatch_flags & I915_DISPATCH_SECURE)
+		i915_gem_object_ggtt_unpin(batch_obj);
+err:
+	/* the request owns the ref now */
+	i915_gem_context_unreference(ctx);
+	eb_destroy(eb);
+
+	mutex_unlock(&dev->struct_mutex);
+
+pre_mutex_err:
+	/* intel_gpu_busy should also get a ref, so it will free when the device
+	 * is really idle. */
+	intel_runtime_pm_put(dev_priv);
+	return ret;
+}
+
+/*
+ * Legacy execbuffer just creates an exec2 list from the original exec object
+ * list array and passes it to the real function.
+ */
+int
+i915_gem_execbuffer(struct drm_device *dev, void *data,
+		    struct drm_file *file)
+{
+	struct drm_i915_gem_execbuffer *args = data;
+	struct drm_i915_gem_execbuffer2 exec2;
+	struct drm_i915_gem_exec_object *exec_list = NULL;
+	struct drm_i915_gem_exec_object2 *exec2_list = NULL;
+	int ret, i;
+
+	if (args->buffer_count < 1) {
+		DRM_DEBUG("execbuf with %d buffers\n", args->buffer_count);
+		return -EINVAL;
+	}
+
+	/* Copy in the exec list from userland */
+	exec_list = drm_malloc_ab(sizeof(*exec_list), args->buffer_count);
+	exec2_list = drm_malloc_ab(sizeof(*exec2_list), args->buffer_count);
+	if (exec_list == NULL || exec2_list == NULL) {
+		DRM_DEBUG("Failed to allocate exec list for %d buffers\n",
+			  args->buffer_count);
+		drm_free_large(exec_list);
+		drm_free_large(exec2_list);
+		return -ENOMEM;
+	}
+	ret = copy_from_user(exec_list,
+			     to_user_ptr(args->buffers_ptr),
+			     sizeof(*exec_list) * args->buffer_count);
+	if (ret != 0) {
+		DRM_DEBUG("copy %d exec entries failed %d\n",
+			  args->buffer_count, ret);
+		drm_free_large(exec_list);
+		drm_free_large(exec2_list);
+		return -EFAULT;
+	}
+
+	for (i = 0; i < args->buffer_count; i++) {
+		exec2_list[i].handle = exec_list[i].handle;
+		exec2_list[i].relocation_count = exec_list[i].relocation_count;
+		exec2_list[i].relocs_ptr = exec_list[i].relocs_ptr;
+		exec2_list[i].alignment = exec_list[i].alignment;
+		exec2_list[i].offset = exec_list[i].offset;
+		if (INTEL_INFO(dev)->gen < 4)
+			exec2_list[i].flags = EXEC_OBJECT_NEEDS_FENCE;
+		else
+			exec2_list[i].flags = 0;
+	}
+
+	exec2.buffers_ptr = args->buffers_ptr;
+	exec2.buffer_count = args->buffer_count;
+	exec2.batch_start_offset = args->batch_start_offset;
+	exec2.batch_len = args->batch_len;
+	exec2.DR1 = args->DR1;
+	exec2.DR4 = args->DR4;
+	exec2.num_cliprects = args->num_cliprects;
+	exec2.cliprects_ptr = args->cliprects_ptr;
+	exec2.flags = I915_EXEC_RENDER;
+	i915_execbuffer2_set_context_id(exec2, 0);
+
+	ret = i915_gem_do_execbuffer(dev, data, file, &exec2, exec2_list);
+	if (!ret) {
+		struct drm_i915_gem_exec_object __user *user_exec_list =
+			to_user_ptr(args->buffers_ptr);
+
+		/* Copy the new buffer offsets back to the user's exec list. */
+		for (i = 0; i < args->buffer_count; i++) {
+			ret = __copy_to_user(&user_exec_list[i].offset,
+					     &exec2_list[i].offset,
+					     sizeof(user_exec_list[i].offset));
+			if (ret) {
+				ret = -EFAULT;
+				DRM_DEBUG("failed to copy %d exec entries "
+					  "back to user (%d)\n",
+					  args->buffer_count, ret);
+				break;
+			}
+		}
+	}
+
+	drm_free_large(exec_list);
+	drm_free_large(exec2_list);
+	return ret;
+}
+
+int
+i915_gem_execbuffer2(struct drm_device *dev, void *data,
+		     struct drm_file *file)
+{
+	struct drm_i915_gem_execbuffer2 *args = data;
+	struct drm_i915_gem_exec_object2 *exec2_list = NULL;
+	int ret;
+
+	if (args->buffer_count < 1 ||
+	    args->buffer_count > UINT_MAX / sizeof(*exec2_list)) {
+		DRM_DEBUG("execbuf2 with %d buffers\n", args->buffer_count);
+		return -EINVAL;
+	}
+
+	if (args->rsvd2 != 0) {
+		DRM_DEBUG("dirty rvsd2 field\n");
+		return -EINVAL;
+	}
+
+	exec2_list = kmalloc(sizeof(*exec2_list)*args->buffer_count,
+			     GFP_TEMPORARY | __GFP_NOWARN | __GFP_NORETRY);
+	if (exec2_list == NULL)
+		exec2_list = drm_malloc_ab(sizeof(*exec2_list),
+					   args->buffer_count);
+	if (exec2_list == NULL) {
+		DRM_DEBUG("Failed to allocate exec list for %d buffers\n",
+			  args->buffer_count);
+		return -ENOMEM;
+	}
+	ret = copy_from_user(exec2_list,
+			     to_user_ptr(args->buffers_ptr),
+			     sizeof(*exec2_list) * args->buffer_count);
+	if (ret != 0) {
+		DRM_DEBUG("copy %d exec entries failed %d\n",
+			  args->buffer_count, ret);
+		drm_free_large(exec2_list);
+		return -EFAULT;
+	}
+
+	ret = i915_gem_do_execbuffer(dev, data, file, args, exec2_list);
+	if (!ret) {
+		/* Copy the new buffer offsets back to the user's exec list. */
+		struct drm_i915_gem_exec_object2 __user *user_exec_list =
+				   to_user_ptr(args->buffers_ptr);
+		int i;
+
+		for (i = 0; i < args->buffer_count; i++) {
+			ret = __copy_to_user(&user_exec_list[i].offset,
+					     &exec2_list[i].offset,
+					     sizeof(user_exec_list[i].offset));
+			if (ret) {
+				ret = -EFAULT;
+				DRM_DEBUG("failed to copy %d exec entries "
+					  "back to user\n",
+					  args->buffer_count);
+				break;
+			}
+		}
+	}
+
+	drm_free_large(exec2_list);
+	return ret;
+}