[RFC PATCH v3 05/17] drm/i915: Support for VM private BOs

[Andi Shyti]

From: Niranjana Vishwanathapura <niranjana.vishwanathapura at intel.com>

Each VM creates a root_obj and shares it with all of its private objects
to use it as dma_resv object. This has a performance advantage as it
requires a single dma_resv object update for all private BOs vs list of
dma_resv objects update for shared BOs, in the execbuf path.

Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura at intel.com>
Signed-off-by: Ramalingam C <ramalingam.c at intel.com>
Signed-off-by: Andi Shyti <andi.shyti at linux.intel.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_object_types.h   | 3 +++
 drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c | 9 +++++++++
 drivers/gpu/drm/i915/gt/intel_gtt.c                | 4 ++++
 drivers/gpu/drm/i915/gt/intel_gtt.h                | 2 ++
 drivers/gpu/drm/i915/i915_vma.c                    | 1 +
 drivers/gpu/drm/i915/i915_vma_types.h              | 2 ++
 6 files changed, 21 insertions(+)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
index 9f6b14ec189a2..46308dcf39e99 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
@@ -241,6 +241,9 @@ struct drm_i915_gem_object {
 
 	const struct drm_i915_gem_object_ops *ops;
 
+	/* For VM private BO, points to root_obj in VM. NULL otherwise */
+	struct drm_i915_gem_object *priv_root;
+
 	struct {
 		/**
 		 * @vma.lock: protect the list/tree of vmas
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c b/drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c
index dadd1d4b1761b..9ff929f187cfd 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c
@@ -93,6 +93,7 @@ void i915_gem_vm_bind_remove(struct i915_vma *vma, bool release_obj)
 
 	if (!list_empty(&vma->vm_bind_link)) {
 		list_del_init(&vma->vm_bind_link);
+		list_del_init(&vma->non_priv_vm_bind_link);
 		i915_vm_bind_it_remove(vma, &vma->vm->va);
 
 		/* Release object */
@@ -219,6 +220,11 @@ static int i915_gem_vm_bind_obj(struct i915_address_space *vm,
 		goto put_obj;
 	}
 
+	if (obj->priv_root && obj->priv_root != vm->root_obj) {
+		ret = -EINVAL;
+		goto put_obj;
+	}
+
 	ret = mutex_lock_interruptible(&vm->vm_bind_lock);
 	if (ret)
 		goto put_obj;
@@ -244,6 +250,9 @@ static int i915_gem_vm_bind_obj(struct i915_address_space *vm,
 
 		list_add_tail(&vma->vm_bind_link, &vm->vm_bound_list);
 		i915_vm_bind_it_insert(vma, &vm->va);
+		if (!obj->priv_root)
+			list_add_tail(&vma->non_priv_vm_bind_link,
+				      &vm->non_priv_vm_bind_list);
 
 out_ww:
 		if (ret == -EDEADLK) {
diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.c b/drivers/gpu/drm/i915/gt/intel_gtt.c
index cb188377b7bd9..c4f75826213ae 100644
--- a/drivers/gpu/drm/i915/gt/intel_gtt.c
+++ b/drivers/gpu/drm/i915/gt/intel_gtt.c
@@ -177,6 +177,7 @@ int i915_vm_lock_objects(struct i915_address_space *vm,
 void i915_address_space_fini(struct i915_address_space *vm)
 {
 	drm_mm_takedown(&vm->mm);
+	i915_gem_object_put(vm->root_obj);
 	GEM_BUG_ON(!RB_EMPTY_ROOT(&vm->va.rb_root));
 	mutex_destroy(&vm->vm_bind_lock);
 }
@@ -292,6 +293,9 @@ void i915_address_space_init(struct i915_address_space *vm, int subclass)
 	INIT_LIST_HEAD(&vm->vm_bind_list);
 	INIT_LIST_HEAD(&vm->vm_bound_list);
 	mutex_init(&vm->vm_bind_lock);
+	INIT_LIST_HEAD(&vm->non_priv_vm_bind_list);
+	vm->root_obj = i915_gem_object_create_internal(vm->i915, PAGE_SIZE);
+	GEM_BUG_ON(IS_ERR(vm->root_obj));
 }
 
 void *__px_vaddr(struct drm_i915_gem_object *p)
diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.h b/drivers/gpu/drm/i915/gt/intel_gtt.h
index 06a259475816b..9a2665e4ec2e5 100644
--- a/drivers/gpu/drm/i915/gt/intel_gtt.h
+++ b/drivers/gpu/drm/i915/gt/intel_gtt.h
@@ -267,6 +267,8 @@ struct i915_address_space {
 	struct list_head vm_bound_list;
 	/* @va: tree of persistent vmas */
 	struct rb_root_cached va;
+	struct list_head non_priv_vm_bind_list;
+	struct drm_i915_gem_object *root_obj;
 
 	/* Global GTT */
 	bool is_ggtt:1;
diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
index 092ae4309d8a1..239346e0c07f2 100644
--- a/drivers/gpu/drm/i915/i915_vma.c
+++ b/drivers/gpu/drm/i915/i915_vma.c
@@ -236,6 +236,7 @@ vma_create(struct drm_i915_gem_object *obj,
 	mutex_unlock(&vm->mutex);
 
 	INIT_LIST_HEAD(&vma->vm_bind_link);
+	INIT_LIST_HEAD(&vma->non_priv_vm_bind_link);
 	return vma;
 
 err_unlock:
diff --git a/drivers/gpu/drm/i915/i915_vma_types.h b/drivers/gpu/drm/i915/i915_vma_types.h
index f746fecae85ed..de5534d518cdd 100644
--- a/drivers/gpu/drm/i915/i915_vma_types.h
+++ b/drivers/gpu/drm/i915/i915_vma_types.h
@@ -291,6 +291,8 @@ struct i915_vma {
 
 	/** @vm_bind_link: node for the vm_bind related lists of vm */
 	struct list_head vm_bind_link;
+	/* @non_priv_vm_bind_link: Link in non-private persistent VMA list */
+	struct list_head non_priv_vm_bind_link;
 
 	/** Interval tree structures for persistent vma */
 
-- 
2.34.1