drm/i915: Pull VM lists under the VM mutex.
A starting point to counter the pervasive struct_mutex. For the goal of
avoiding (or at least blocking under them!) global locks during user
request submission, a simple but important step is being able to manage
each clients GTT separately. For which, we want to replace using the
struct_mutex as the guard for all things GTT/VM and switch instead to a
specific mutex inside i915_address_space.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190128102356.15037-2-chris@chris-wilson.co.uk
diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
index 7de28ba..dcbd0d3 100644
--- a/drivers/gpu/drm/i915/i915_vma.c
+++ b/drivers/gpu/drm/i915/i915_vma.c
@@ -213,7 +213,10 @@ vma_create(struct drm_i915_gem_object *obj,
}
rb_link_node(&vma->obj_node, rb, p);
rb_insert_color(&vma->obj_node, &obj->vma_tree);
+
+ mutex_lock(&vm->mutex);
list_add(&vma->vm_link, &vm->unbound_list);
+ mutex_unlock(&vm->mutex);
return vma;
@@ -656,7 +659,9 @@ i915_vma_insert(struct i915_vma *vma, u64 size, u64 alignment, u64 flags)
GEM_BUG_ON(!drm_mm_node_allocated(&vma->node));
GEM_BUG_ON(!i915_gem_valid_gtt_space(vma, cache_level));
+ mutex_lock(&vma->vm->mutex);
list_move_tail(&vma->vm_link, &vma->vm->bound_list);
+ mutex_unlock(&vma->vm->mutex);
if (vma->obj) {
struct drm_i915_gem_object *obj = vma->obj;
@@ -689,8 +694,10 @@ i915_vma_remove(struct i915_vma *vma)
vma->ops->clear_pages(vma);
+ mutex_lock(&vma->vm->mutex);
drm_mm_remove_node(&vma->node);
list_move_tail(&vma->vm_link, &vma->vm->unbound_list);
+ mutex_unlock(&vma->vm->mutex);
/*
* Since the unbound list is global, only move to that list if
@@ -802,7 +809,11 @@ static void __i915_vma_destroy(struct i915_vma *vma)
GEM_BUG_ON(i915_gem_active_isset(&vma->last_fence));
list_del(&vma->obj_link);
+
+ mutex_lock(&vma->vm->mutex);
list_del(&vma->vm_link);
+ mutex_unlock(&vma->vm->mutex);
+
if (vma->obj)
rb_erase(&vma->obj_node, &vma->obj->vma_tree);