[PATCH 01/11] drm/i915/dsb: Extract intel_dsb_ins_align()

[Chaitanya Kumar Borah]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

Extract the code that alings the next instruction to the next
QW boundary into a small helper. I'll have some more uses for
this later.

Also explain why we don't have to zero out the extra DW.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/display/intel_dsb.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_dsb.c b/drivers/gpu/drm/i915/display/intel_dsb.c
index 0ddcdedf5453..c166e02b8af0 100644
--- a/drivers/gpu/drm/i915/display/intel_dsb.c
+++ b/drivers/gpu/drm/i915/display/intel_dsb.c
@@ -228,13 +228,25 @@ static bool is_dsb_busy(struct intel_display *display, enum pipe pipe,
 	return intel_de_read_fw(display, DSB_CTRL(pipe, dsb_id)) & DSB_STATUS_BUSY;
 }
 
+static void intel_dsb_ins_align(struct intel_dsb *dsb)
+{
+	/*
+	 * Every instruction should be 8 byte aligned.
+	 *
+	 * The only way to get unaligned free_pos is via
+	 * intel_dsb_reg_write_indexed() which already
+	 * makes sure the next dword is zeroed, so no need
+	 * to clear it here.
+	 */
+	dsb->free_pos = ALIGN(dsb->free_pos, 2);
+}
+
 static void intel_dsb_emit(struct intel_dsb *dsb, u32 ldw, u32 udw)
 {
 	if (!assert_dsb_has_room(dsb))
 		return;
 
-	/* Every instruction should be 8 byte aligned. */
-	dsb->free_pos = ALIGN(dsb->free_pos, 2);
+	intel_dsb_ins_align(dsb);
 
 	dsb->ins_start_offset = dsb->free_pos;
 	dsb->ins[0] = ldw;
-- 
2.25.1