drm/i915: Wrap all access to i915_vma.node.start|size

We already wrap i915_vma.node.start for use with the GGTT, as there we
can perform additional sanity checks that the node belongs to the GGTT
and fits within the 32b registers. In the next couple of patches, we
will introduce guard pages around the objects _inside_ the drm_mm_node
allocation. That is we will offset the vma->pages so that the first page
is at drm_mm_node.start + vma->guard (not 0 as is currently the case).
All users must then not use i915_vma.node.start directly, but compute
the guard offset, thus all users are converted to use a
i915_vma_offset() wrapper.

The notable exceptions are the selftests that are testing exact
behaviour of i915_vma_pin/i915_vma_insert.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Tejas Upadhyay <tejaskumarx.surendrakumar.upadhyay@intel.com>
Co-developed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221130235805.221010-3-andi.shyti@linux.intel.com

1 files changed, 13 insertions, 12 deletions

diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
index 726705b10637..fefee5fef38d 100644
--- a/drivers/gpu/drm/i915/i915_vma.c
+++ b/drivers/gpu/drm/i915/i915_vma.c
@@ -418,8 +418,8 @@ i915_vma_resource_init_from_vma(struct i915_vma_resource *vma_res,
 	i915_vma_resource_init(vma_res, vma->vm, vma->pages, &vma->page_sizes,
 			       obj->mm.rsgt, i915_gem_object_is_readonly(obj),
 			       i915_gem_object_is_lmem(obj), obj->mm.region,
-			       vma->ops, vma->private, vma->node.start,
-			       vma->node.size, vma->size);
+			       vma->ops, vma->private, __i915_vma_offset(vma),
+			       __i915_vma_size(vma), vma->size);
 }
 
 /**
@@ -447,7 +447,7 @@ int i915_vma_bind(struct i915_vma *vma,
 
 	lockdep_assert_held(&vma->vm->mutex);
 	GEM_BUG_ON(!drm_mm_node_allocated(&vma->node));
-	GEM_BUG_ON(vma->size > vma->node.size);
+	GEM_BUG_ON(vma->size > i915_vma_size(vma));
 
 	if (GEM_DEBUG_WARN_ON(range_overflows(vma->node.start,
 					      vma->node.size,
@@ -569,8 +569,8 @@ void __iomem *i915_vma_pin_iomap(struct i915_vma *vma)
 							  vma->obj->base.size);
 		} else if (i915_vma_is_map_and_fenceable(vma)) {
 			ptr = io_mapping_map_wc(&i915_vm_to_ggtt(vma->vm)->iomap,
-						vma->node.start,
-						vma->node.size);
+						i915_vma_offset(vma),
+						i915_vma_size(vma));
 		} else {
 			ptr = (void __iomem *)
 				i915_gem_object_pin_map(vma->obj, I915_MAP_WC);
@@ -659,22 +659,22 @@ bool i915_vma_misplaced(const struct i915_vma *vma,
 	if (test_bit(I915_VMA_ERROR_BIT, __i915_vma_flags(vma)))
 		return true;
 
-	if (vma->node.size < size)
+	if (i915_vma_size(vma) < size)
 		return true;
 
 	GEM_BUG_ON(alignment && !is_power_of_2(alignment));
-	if (alignment && !IS_ALIGNED(vma->node.start, alignment))
+	if (alignment && !IS_ALIGNED(i915_vma_offset(vma), alignment))
 		return true;
 
 	if (flags & PIN_MAPPABLE && !i915_vma_is_map_and_fenceable(vma))
 		return true;
 
 	if (flags & PIN_OFFSET_BIAS &&
-	    vma->node.start < (flags & PIN_OFFSET_MASK))
+	    i915_vma_offset(vma) < (flags & PIN_OFFSET_MASK))
 		return true;
 
 	if (flags & PIN_OFFSET_FIXED &&
-	    vma->node.start != (flags & PIN_OFFSET_MASK))
+	    i915_vma_offset(vma) != (flags & PIN_OFFSET_MASK))
 		return true;
 
 	return false;
@@ -687,10 +687,11 @@ void __i915_vma_set_map_and_fenceable(struct i915_vma *vma)
 	GEM_BUG_ON(!i915_vma_is_ggtt(vma));
 	GEM_BUG_ON(!vma->fence_size);
 
-	fenceable = (vma->node.size >= vma->fence_size &&
-		     IS_ALIGNED(vma->node.start, vma->fence_alignment));
+	fenceable = (i915_vma_size(vma) >= vma->fence_size &&
+		     IS_ALIGNED(i915_vma_offset(vma), vma->fence_alignment));
 
-	mappable = vma->node.start + vma->fence_size <= i915_vm_to_ggtt(vma->vm)->mappable_end;
+	mappable = i915_ggtt_offset(vma) + vma->fence_size <=
+		   i915_vm_to_ggtt(vma->vm)->mappable_end;
 
 	if (mappable && fenceable)
 		set_bit(I915_VMA_CAN_FENCE_BIT, __i915_vma_flags(vma));