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, 18 insertions, 15 deletions

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index 7d742f7e52b8..16618a548026 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -378,22 +378,25 @@ eb_vma_misplaced(const struct drm_i915_gem_exec_object2 *entry,
 		 const struct i915_vma *vma,
 		 unsigned int flags)
 {
-	if (vma->node.size < entry->pad_to_size)
+	const u64 start = i915_vma_offset(vma);
+	const u64 size = i915_vma_size(vma);
+
+	if (size < entry->pad_to_size)
 		return true;
 
-	if (entry->alignment && !IS_ALIGNED(vma->node.start, entry->alignment))
+	if (entry->alignment && !IS_ALIGNED(start, entry->alignment))
 		return true;
 
 	if (flags & EXEC_OBJECT_PINNED &&
-	    vma->node.start != entry->offset)
+	    start != entry->offset)
 		return true;
 
 	if (flags & __EXEC_OBJECT_NEEDS_BIAS &&
-	    vma->node.start < BATCH_OFFSET_BIAS)
+	    start < BATCH_OFFSET_BIAS)
 		return true;
 
 	if (!(flags & EXEC_OBJECT_SUPPORTS_48B_ADDRESS) &&
-	    (vma->node.start + vma->node.size + 4095) >> 32)
+	    (start + size + 4095) >> 32)
 		return true;
 
 	if (flags & __EXEC_OBJECT_NEEDS_MAP &&
@@ -439,7 +442,7 @@ eb_pin_vma(struct i915_execbuffer *eb,
 	int err;
 
 	if (vma->node.size)
-		pin_flags = vma->node.start;
+		pin_flags =  __i915_vma_offset(vma);
 	else
 		pin_flags = entry->offset & PIN_OFFSET_MASK;
 
@@ -662,8 +665,8 @@ static int eb_reserve_vma(struct i915_execbuffer *eb,
 	if (err)
 		return err;
 
-	if (entry->offset != vma->node.start) {
-		entry->offset = vma->node.start | UPDATE;
+	if (entry->offset != i915_vma_offset(vma)) {
+		entry->offset = i915_vma_offset(vma) | UPDATE;
 		eb->args->flags |= __EXEC_HAS_RELOC;
 	}
 
@@ -983,8 +986,8 @@ static int eb_validate_vmas(struct i915_execbuffer *eb)
 			return err;
 
 		if (!err) {
-			if (entry->offset != vma->node.start) {
-				entry->offset = vma->node.start | UPDATE;
+			if (entry->offset != i915_vma_offset(vma)) {
+				entry->offset = i915_vma_offset(vma) | UPDATE;
 				eb->args->flags |= __EXEC_HAS_RELOC;
 			}
 		} else {
@@ -1065,7 +1068,7 @@ static inline u64
 relocation_target(const struct drm_i915_gem_relocation_entry *reloc,
 		  const struct i915_vma *target)
 {
-	return gen8_canonical_addr((int)reloc->delta + target->node.start);
+	return gen8_canonical_addr((int)reloc->delta + i915_vma_offset(target));
 }
 
 static void reloc_cache_init(struct reloc_cache *cache,
@@ -1274,7 +1277,7 @@ static void *reloc_iomap(struct i915_vma *batch,
 			if (err) /* no inactive aperture space, use cpu reloc */
 				return NULL;
 		} else {
-			cache->node.start = vma->node.start;
+			cache->node.start = i915_ggtt_offset(vma);
 			cache->node.mm = (void *)vma;
 		}
 	}
@@ -1437,7 +1440,7 @@ eb_relocate_entry(struct i915_execbuffer *eb,
 	 * more work needs to be done.
 	 */
 	if (!DBG_FORCE_RELOC &&
-	    gen8_canonical_addr(target->vma->node.start) == reloc->presumed_offset)
+	    gen8_canonical_addr(i915_vma_offset(target->vma)) == reloc->presumed_offset)
 		return 0;
 
 	/* Check that the relocation address is valid... */
@@ -2367,7 +2370,7 @@ static int eb_request_submit(struct i915_execbuffer *eb,
 	}
 
 	err = rq->context->engine->emit_bb_start(rq,
-						 batch->node.start +
+						 i915_vma_offset(batch) +
 						 eb->batch_start_offset,
 						 batch_len,
 						 eb->batch_flags);
@@ -2378,7 +2381,7 @@ static int eb_request_submit(struct i915_execbuffer *eb,
 		GEM_BUG_ON(intel_context_is_parallel(rq->context));
 		GEM_BUG_ON(eb->batch_start_offset);
 		err = rq->context->engine->emit_bb_start(rq,
-							 eb->trampoline->node.start +
+							 i915_vma_offset(eb->trampoline) +
 							 batch_len, 0, 0);
 		if (err)
 			return err;