drm/xe: Clarify 'gt' retrieval for primary tile

There are a bunch of places in the driver where we need to perform
non-GT MMIO against the platform's primary tile (display code, top-level
interrupt enable/disable, driver initialization, etc.).  Rename
'to_gt()' to 'xe_primary_mmio_gt()' to clarify that we're trying to get
a primary MMIO handle for these top-level operations.

In the future we need to move away from xe_gt as the target for MMIO
operations (most of which are completely unrelated to GT).

v2:
 - s/xe_primary_mmio_gt/xe_root_mmio_gt/ for more consistency with how
   we refer to tile 0.  (Lucas)
v3:
 - Tweak comment on xe_root_mmio_gt().  (Lucas)

Acked-by: Nirmoy Das <nirmoy.das@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://lore.kernel.org/r/20230601215244.678611-16-matthew.d.roper@intel.com
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

1 files changed, 11 insertions, 2 deletions

diff --git a/drivers/gpu/drm/xe/xe_device.h b/drivers/gpu/drm/xe/xe_device.h
index 3516ac1dcbc4..e88f685f3f21 100644
--- a/drivers/gpu/drm/xe/xe_device.h
+++ b/drivers/gpu/drm/xe/xe_device.h
@@ -66,9 +66,18 @@ static inline struct xe_gt *xe_device_get_gt(struct xe_device *xe, u8 gt_id)
 }
 
 /*
- * FIXME: Placeholder until multi-gt lands. Once that lands, kill this function.
+ * Provide a GT structure suitable for performing non-GT MMIO operations against
+ * the primary tile.  Primarily intended for early tile initialization, display
+ * handling, top-most interrupt enable/disable, etc.  Since anything using the
+ * MMIO handle returned by this function doesn't need GSI offset translation,
+ * we'll return the primary GT from the root tile.
+ *
+ * FIXME: Fix the driver design so that 'gt' isn't the target of all MMIO
+ * operations.
+ *
+ * Returns the primary gt of the root tile.
  */
-static inline struct xe_gt *to_gt(struct xe_device *xe)
+static inline struct xe_gt *xe_root_mmio_gt(struct xe_device *xe)
 {
 	return &xe_device_get_root_tile(xe)->primary_gt;
 }