drm/i915/dsb: Introduce intel_dsb_align_tail()

Move the DSB tail cacheline alignment to a helper. No need to pollute
the caller with mundane details like this.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221216003810.13338-10-ville.syrjala@linux.intel.com
Reviewed-by: Animesh Manna <animesh.manna@intel.com>

diff --git a/drivers/gpu/drm/i915/display/intel_dsb.c b/drivers/gpu/drm/i915/display/intel_dsb.c
index fa4b808..636c577 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_dsb.c
+++ b/drivers/gpu/drm/i915/display/intel_dsb.c
@@ -187,6 +187,22 @@ void intel_dsb_reg_write(struct intel_dsb *dsb,
        }
 }
 
+static u32 intel_dsb_align_tail(struct intel_dsb *dsb)
+{
+       u32 aligned_tail, tail;
+
+       tail = dsb->free_pos * 4;
+       aligned_tail = ALIGN(tail, CACHELINE_BYTES);
+
+       if (aligned_tail > tail)
+               memset(&dsb->cmd_buf[dsb->free_pos], 0,
+                      aligned_tail - tail);
+
+       dsb->free_pos = aligned_tail / 4;
+
+       return aligned_tail;
+}
+
 /**
  * intel_dsb_commit() - Trigger workload execution of DSB.
  * @dsb: DSB context
@@ -200,14 +216,10 @@ void intel_dsb_commit(struct intel_dsb *dsb)
        enum pipe pipe = crtc->pipe;
        u32 tail;
 
-       if (!(dsb && dsb->free_pos))
+       tail = intel_dsb_align_tail(dsb);
+       if (tail == 0)
                return;
 
-       tail = ALIGN(dsb->free_pos * 4, CACHELINE_BYTES);
-       if (tail > dsb->free_pos * 4)
-               memset(&dsb->cmd_buf[dsb->free_pos], 0,
-                      (tail - dsb->free_pos * 4));
-
        if (is_dsb_busy(dev_priv, pipe, dsb->id)) {
                drm_err(&dev_priv->drm, "DSB engine is busy.\n");
                goto reset;