[Intel-gfx] [PATCH v2 10/15] drm/i915/dsb: function to trigger workload execution of DSB.

[Animesh Manna]

Batch buffer will be created through dsb-reg-write function which can have
single/multiple request based on usecase and once the buffer is ready
commit function will trigger the execution of the batch buffer. All
the registers will be updated simultaneously.

Cc: Imre Deak <imre.deak at intel.com>
Cc: Jani Nikula <jani.nikula at intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
Signed-off-by: Animesh Manna <animesh.manna at intel.com>
---
 drivers/gpu/drm/i915/display/intel_dsb.c | 43 ++++++++++++++++++++++++
 drivers/gpu/drm/i915/display/intel_dsb.h |  1 +
 2 files changed, 44 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_dsb.c b/drivers/gpu/drm/i915/display/intel_dsb.c
index f97d0c06a049..7e0a9b37f702 100644
--- a/drivers/gpu/drm/i915/display/intel_dsb.c
+++ b/drivers/gpu/drm/i915/display/intel_dsb.c
@@ -191,3 +191,46 @@ void intel_dsb_reg_write(struct intel_dsb *dsb, i915_reg_t reg, u32 val)
 				DSB_OPCODE_SHIFT) | DSB_BYTE_EN |
 				i915_mmio_reg_offset(reg);
 }
+
+void intel_dsb_commit(struct intel_dsb *dsb)
+{
+	struct intel_crtc *crtc = dsb->crtc;
+	struct drm_device *dev = crtc->base.dev;
+	struct drm_i915_private *dev_priv = to_i915(dev);
+	enum pipe pipe = crtc->pipe;
+	u32 cmd_buf_tail, cmd_buf_size;
+
+	if (!dsb->free_pos)
+		return;
+
+	if (!intel_dsb_enable_engine(dsb))
+		goto reset;
+
+	if (is_dsb_busy(dsb)) {
+		DRM_DEBUG_KMS("HEAD_PTR write failed - dsb engine is busy.\n");
+		goto reset;
+	}
+	I915_WRITE(DSB_HEAD_PTR(pipe, dsb->id), dsb->cmd_buf_head);
+
+	cmd_buf_size = dsb->free_pos * 4;
+	cmd_buf_tail = round_up((dsb->cmd_buf_head + cmd_buf_size),
+				CACHELINE_BYTES);
+
+	if (is_dsb_busy(dsb)) {
+		DRM_DEBUG_KMS("TAIL_PTR write failed - dsb engine is busy.\n");
+		goto reset;
+	}
+	DRM_DEBUG_KMS("DSB execution started - buf-size %u, head 0x%x,"
+		      "tail 0x%x\n", cmd_buf_size, dsb->cmd_buf_head,
+		      cmd_buf_tail);
+	I915_WRITE(DSB_TAIL_PTR(pipe, dsb->id), cmd_buf_tail);
+	if (wait_for(!is_dsb_busy(dsb), 1)) {
+		DRM_ERROR("Timed out waiting for DSB workload completion.\n");
+		goto reset;
+	}
+
+reset:
+	memset(dsb->cmd_buf, 0, DSB_BUF_SIZE);
+	dsb->free_pos = 0;
+	intel_dsb_disable_engine(dsb);
+}
diff --git a/drivers/gpu/drm/i915/display/intel_dsb.h b/drivers/gpu/drm/i915/display/intel_dsb.h
index 1fa893cc8c2e..7330add3c96f 100644
--- a/drivers/gpu/drm/i915/display/intel_dsb.h
+++ b/drivers/gpu/drm/i915/display/intel_dsb.h
@@ -42,5 +42,6 @@ struct intel_dsb {
 struct intel_dsb *
 intel_dsb_get(struct intel_crtc *crtc);
 void intel_dsb_reg_write(struct intel_dsb *dsb, i915_reg_t reg, u32 val);
+void intel_dsb_commit(struct intel_dsb *dsb);
 
 #endif
-- 
2.22.0