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

Andi Shyti
2022-08-27T19:46:04Z

From: Niranjana Vishwanathapura <niranjana.vishwanathapura@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@intel.com>
Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
Signed-off-by: Andi Shyti <andi.shyti@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