drm/i915: Add a new "remapped" gtt_view

To overcome display engine stride limits we'll want to remap the
pages in the GTT. To that end we need a new gtt_view type which
is just like the "rotated" type except not rotated.

v2: Use intel_remapped_plane_info base type
    s/unused/unused_mbz/ (Chris)
    Separate BUILD_BUG_ON()s (Chris)
    Use I915_GTT_PAGE_SIZE (Chris)
v3: Use i915_gem_object_get_dma_address() (Chris)
    Trim the sg (Tvrtko)
v4: Actually trim this time. Limit the max length
    to one row of pages to keep things simple

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190509122159.24376-2-ville.syrjala@linux.intel.com
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

1 files changed, 21 insertions, 4 deletions

diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.h b/drivers/gpu/drm/i915/i915_gem_gtt.h
index 2fafa04c45ec..98fc71053f7c 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.h
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.h
@@ -163,11 +163,18 @@ typedef u64 gen8_ppgtt_pml4e_t;
 
 struct sg_table;
 
+struct intel_remapped_plane_info {
+	/* in gtt pages */
+	unsigned int width, height, stride, offset;
+} __packed;
+
+struct intel_remapped_info {
+	struct intel_remapped_plane_info plane[2];
+	unsigned int unused_mbz;
+} __packed;
+
 struct intel_rotation_info {
-	struct intel_rotation_plane_info {
-		/* tiles */
-		unsigned int width, height, stride, offset;
-	} plane[2];
+	struct intel_remapped_plane_info plane[2];
 } __packed;
 
 struct intel_partial_info {
@@ -179,12 +186,20 @@ enum i915_ggtt_view_type {
 	I915_GGTT_VIEW_NORMAL = 0,
 	I915_GGTT_VIEW_ROTATED = sizeof(struct intel_rotation_info),
 	I915_GGTT_VIEW_PARTIAL = sizeof(struct intel_partial_info),
+	I915_GGTT_VIEW_REMAPPED = sizeof(struct intel_remapped_info),
 };
 
 static inline void assert_i915_gem_gtt_types(void)
 {
 	BUILD_BUG_ON(sizeof(struct intel_rotation_info) != 8*sizeof(unsigned int));
 	BUILD_BUG_ON(sizeof(struct intel_partial_info) != sizeof(u64) + sizeof(unsigned int));
+	BUILD_BUG_ON(sizeof(struct intel_remapped_info) != 9*sizeof(unsigned int));
+
+	/* Check that rotation/remapped shares offsets for simplicity */
+	BUILD_BUG_ON(offsetof(struct intel_remapped_info, plane[0]) !=
+		     offsetof(struct intel_rotation_info, plane[0]));
+	BUILD_BUG_ON(offsetofend(struct intel_remapped_info, plane[1]) !=
+		     offsetofend(struct intel_rotation_info, plane[1]));
 
 	/* As we encode the size of each branch inside the union into its type,
 	 * we have to be careful that each branch has a unique size.
@@ -193,6 +208,7 @@ static inline void assert_i915_gem_gtt_types(void)
 	case I915_GGTT_VIEW_NORMAL:
 	case I915_GGTT_VIEW_PARTIAL:
 	case I915_GGTT_VIEW_ROTATED:
+	case I915_GGTT_VIEW_REMAPPED:
 		/* gcc complains if these are identical cases */
 		break;
 	}
@@ -204,6 +220,7 @@ struct i915_ggtt_view {
 		/* Members need to contain no holes/padding */
 		struct intel_partial_info partial;
 		struct intel_rotation_info rotated;
+		struct intel_remapped_info remapped;
 	};
 };