[Intel-gfx] [PATCH v5] drm/i915/dsb: Pre allocate and late cleanup of cmd buffer

Animesh Manna animesh.manna at intel.com
Wed May 6 13:11:12 UTC 2020


Pre-allocate command buffer in atomic_commit using intel_dsb_prepare
function which also includes pinning and map in cpu domain.

No change is dsb write/commit functions.

Now dsb get/put function is refactored and currently used only for
reference counting. Below dsb api added to do respective job
mentioned below.

intel_dsb_prepare - Allocate, pin and map the buffer.
intel_dsb_cleanup - Unpin and release the gem object.

RFC: Initial patch for design review.
v2: included _init() part in _prepare(). [Daniel, Ville]
v3: dsb_cleanup called after cleanup_planes. [Daniel]
v4: dsb structure is moved to intel_crtc_state from intel_crtc. [Maarten]
v5: dsb get/put/ref-count mechanism removed. [Maarten]

Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Cc: Jani Nikula <jani.nikula at intel.com>
Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
Acked-by: Daniel Vetter <daniel.vetter at ffwll.ch>
Signed-off-by: Animesh Manna <animesh.manna at intel.com>
---
 drivers/gpu/drm/i915/display/intel_color.c    |  27 ++-
 drivers/gpu/drm/i915/display/intel_display.c  |  60 ++++-
 .../drm/i915/display/intel_display_types.h    |   6 +-
 drivers/gpu/drm/i915/display/intel_dsb.c      | 207 +++++++++---------
 drivers/gpu/drm/i915/display/intel_dsb.h      |   8 +-
 5 files changed, 178 insertions(+), 130 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_color.c b/drivers/gpu/drm/i915/display/intel_color.c
index 98ece9cd7cdd..dba820136106 100644
--- a/drivers/gpu/drm/i915/display/intel_color.c
+++ b/drivers/gpu/drm/i915/display/intel_color.c
@@ -717,7 +717,8 @@ static void bdw_load_lut_10(struct intel_crtc *crtc,
 static void ivb_load_lut_ext_max(struct intel_crtc *crtc)
 {
 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
-	struct intel_dsb *dsb = intel_dsb_get(crtc);
+	struct intel_crtc_state *crtc_state = to_intel_crtc_state(crtc->base.state);
+	struct intel_dsb *dsb = (struct intel_dsb *)&crtc_state->dsb;
 	enum pipe pipe = crtc->pipe;
 
 	/* Program the max register to clamp values > 1.0. */
@@ -738,8 +739,6 @@ static void ivb_load_lut_ext_max(struct intel_crtc *crtc)
 		intel_dsb_reg_write(dsb, PREC_PAL_EXT2_GC_MAX(pipe, 2),
 				    1 << 16);
 	}
-
-	intel_dsb_put(dsb);
 }
 
 static void ivb_load_luts(const struct intel_crtc_state *crtc_state)
@@ -900,14 +899,13 @@ icl_load_gcmax(const struct intel_crtc_state *crtc_state,
 	       const struct drm_color_lut *color)
 {
 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
-	struct intel_dsb *dsb = intel_dsb_get(crtc);
+	struct intel_dsb *dsb = (struct intel_dsb *)&crtc_state->dsb;
 	enum pipe pipe = crtc->pipe;
 
 	/* FIXME LUT entries are 16 bit only, so we can prog 0xFFFF max */
 	intel_dsb_reg_write(dsb, PREC_PAL_GC_MAX(pipe, 0), color->red);
 	intel_dsb_reg_write(dsb, PREC_PAL_GC_MAX(pipe, 1), color->green);
 	intel_dsb_reg_write(dsb, PREC_PAL_GC_MAX(pipe, 2), color->blue);
-	intel_dsb_put(dsb);
 }
 
 static void
@@ -916,7 +914,7 @@ icl_program_gamma_superfine_segment(const struct intel_crtc_state *crtc_state)
 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
 	const struct drm_property_blob *blob = crtc_state->hw.gamma_lut;
 	const struct drm_color_lut *lut = blob->data;
-	struct intel_dsb *dsb = intel_dsb_get(crtc);
+	struct intel_dsb *dsb = (struct intel_dsb *)&crtc_state->dsb;
 	enum pipe pipe = crtc->pipe;
 	int i;
 
@@ -938,8 +936,6 @@ icl_program_gamma_superfine_segment(const struct intel_crtc_state *crtc_state)
 		intel_dsb_indexed_reg_write(dsb, PREC_PAL_MULTI_SEG_DATA(pipe),
 					    ilk_lut_12p4_udw(entry));
 	}
-
-	intel_dsb_put(dsb);
 }
 
 static void
@@ -949,7 +945,7 @@ icl_program_gamma_multi_segment(const struct intel_crtc_state *crtc_state)
 	const struct drm_property_blob *blob = crtc_state->hw.gamma_lut;
 	const struct drm_color_lut *lut = blob->data;
 	const struct drm_color_lut *entry;
-	struct intel_dsb *dsb = intel_dsb_get(crtc);
+	struct intel_dsb *dsb = (struct intel_dsb *)&crtc_state->dsb;
 	enum pipe pipe = crtc->pipe;
 	int i;
 
@@ -996,14 +992,22 @@ icl_program_gamma_multi_segment(const struct intel_crtc_state *crtc_state)
 	entry = &lut[256 * 8 * 128];
 	icl_load_gcmax(crtc_state, entry);
 	ivb_load_lut_ext_max(crtc);
-	intel_dsb_put(dsb);
 }
 
 static void icl_load_luts(const struct intel_crtc_state *crtc_state)
 {
 	const struct drm_property_blob *gamma_lut = crtc_state->hw.gamma_lut;
 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
-	struct intel_dsb *dsb = intel_dsb_get(crtc);
+	struct intel_dsb *dsb = (struct intel_dsb *)&crtc_state->dsb;
+
+	/*
+	 * TODO: Currently dsb buffer filling is done in load_lut() which
+	 * can be done much earlier, like initial stage of atomic_commit().
+	 * As currently replacing the mmio-write with dsb-write so the same
+	 * load_lut() api is used for dsb buffer creation which may not
+	 * fit in initial stage. Need to create a separate interface and
+	 * a different path in color framework while dealing with dsb.
+	 */
 
 	if (crtc_state->hw.degamma_lut)
 		glk_load_degamma_lut(crtc_state);
@@ -1022,7 +1026,6 @@ static void icl_load_luts(const struct intel_crtc_state *crtc_state)
 	}
 
 	intel_dsb_commit(dsb);
-	intel_dsb_put(dsb);
 }
 
 static u32 chv_cgm_degamma_ldw(const struct drm_color_lut *color)
diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index fd6d63b03489..07670893c1ae 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -14873,8 +14873,28 @@ static int intel_atomic_check(struct drm_device *dev,
 
 static int intel_atomic_prepare_commit(struct intel_atomic_state *state)
 {
-	return drm_atomic_helper_prepare_planes(state->base.dev,
-						&state->base);
+	struct intel_crtc_state *crtc_state;
+	struct intel_crtc *crtc;
+	int i, ret;
+
+	ret = drm_atomic_helper_prepare_planes(state->base.dev, &state->base);
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * In case of DSB buffer creation failure register programming will be
+	 * done by mmio and erroneous path will be handled by dsp-write api.
+	 */
+	for_each_new_intel_crtc_in_state(state, crtc, crtc_state, i) {
+		bool mode_changed = needs_modeset(crtc_state);
+
+		if (mode_changed || crtc_state->update_pipe ||
+		    crtc_state->uapi.color_mgmt_changed) {
+			intel_dsb_prepare(crtc_state);
+		}
+	}
+
+	return 0;
 }
 
 u32 intel_crtc_get_vblank_counter(struct intel_crtc *crtc)
@@ -15327,15 +15347,39 @@ static void intel_atomic_commit_fence_wait(struct intel_atomic_state *intel_stat
 		    &wait_reset);
 }
 
+static void intel_cleanup_dsbs(struct intel_atomic_state *state)
+{
+	struct intel_crtc_state *crtc_state, *old_crtc_state, *new_crtc_state;
+	struct intel_crtc *crtc;
+	int i;
+
+	for_each_oldnew_intel_crtc_in_state(state, crtc, old_crtc_state, new_crtc_state, i) {
+		bool mode_changed;
+
+		if (old_crtc_state == crtc->config)
+			crtc_state = new_crtc_state;
+		else
+			crtc_state = old_crtc_state;
+
+		mode_changed = needs_modeset(crtc_state);
+		if (mode_changed || crtc_state->update_pipe ||
+		    crtc_state->uapi.color_mgmt_changed) {
+			intel_dsb_cleanup(crtc_state);
+		}
+	}
+}
+
 static void intel_atomic_cleanup_work(struct work_struct *work)
 {
-	struct drm_atomic_state *state =
-		container_of(work, struct drm_atomic_state, commit_work);
-	struct drm_i915_private *i915 = to_i915(state->dev);
+	struct intel_atomic_state *state =
+		container_of(work, struct intel_atomic_state, base.commit_work);
+	struct drm_i915_private *i915 = to_i915(state->base.dev);
 
-	drm_atomic_helper_cleanup_planes(&i915->drm, state);
-	drm_atomic_helper_commit_cleanup_done(state);
-	drm_atomic_state_put(state);
+	if (HAS_DSB(i915))
+		intel_cleanup_dsbs(state);
+	drm_atomic_helper_cleanup_planes(&i915->drm, &state->base);
+	drm_atomic_helper_commit_cleanup_done(&state->base);
+	drm_atomic_state_put(&state->base);
 
 	intel_atomic_helper_free_state(i915);
 }
diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index 9488449e4b94..805ca774e146 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -1078,6 +1078,9 @@ struct intel_crtc_state {
 
 	/* Only valid on TGL+ */
 	enum transcoder mst_master_transcoder;
+
+	/* For DSB related info */
+	struct intel_dsb dsb;
 };
 
 enum intel_pipe_crc_source {
@@ -1147,9 +1150,6 @@ struct intel_crtc {
 	/* scalers available on this crtc */
 	int num_scalers;
 
-	/* per pipe DSB related info */
-	struct intel_dsb dsb;
-
 #ifdef CONFIG_DEBUG_FS
 	struct intel_pipe_crc pipe_crc;
 #endif
diff --git a/drivers/gpu/drm/i915/display/intel_dsb.c b/drivers/gpu/drm/i915/display/intel_dsb.c
index 29fec6a92d17..247fd564d394 100644
--- a/drivers/gpu/drm/i915/display/intel_dsb.c
+++ b/drivers/gpu/drm/i915/display/intel_dsb.c
@@ -34,18 +34,22 @@
 #define DSB_BYTE_EN_SHIFT		20
 #define DSB_REG_VALUE_MASK		0xfffff
 
-static bool is_dsb_busy(struct intel_dsb *dsb)
+static inline bool is_dsb_busy(struct intel_dsb *dsb)
 {
-	struct intel_crtc *crtc = container_of(dsb, typeof(*crtc), dsb);
+	struct intel_crtc_state *crtc_state =
+		container_of(dsb, typeof(*crtc_state), dsb);
+	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
 	enum pipe pipe = crtc->pipe;
 
 	return DSB_STATUS & intel_de_read(dev_priv, DSB_CTRL(pipe, dsb->id));
 }
 
-static bool intel_dsb_enable_engine(struct intel_dsb *dsb)
+static inline bool intel_dsb_enable_engine(struct intel_dsb *dsb)
 {
-	struct intel_crtc *crtc = container_of(dsb, typeof(*crtc), dsb);
+	struct intel_crtc_state *crtc_state =
+		container_of(dsb, typeof(*crtc_state), dsb);
+	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
 	enum pipe pipe = crtc->pipe;
 	u32 dsb_ctrl;
@@ -63,9 +67,11 @@ static bool intel_dsb_enable_engine(struct intel_dsb *dsb)
 	return true;
 }
 
-static bool intel_dsb_disable_engine(struct intel_dsb *dsb)
+static inline bool intel_dsb_disable_engine(struct intel_dsb *dsb)
 {
-	struct intel_crtc *crtc = container_of(dsb, typeof(*crtc), dsb);
+	struct intel_crtc_state *crtc_state =
+		container_of(dsb, typeof(*crtc_state), dsb);
+	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
 	enum pipe pipe = crtc->pipe;
 	u32 dsb_ctrl;
@@ -83,99 +89,6 @@ static bool intel_dsb_disable_engine(struct intel_dsb *dsb)
 	return true;
 }
 
-/**
- * intel_dsb_get() - Allocate DSB context and return a DSB instance.
- * @crtc: intel_crtc structure to get pipe info.
- *
- * This function provides handle of a DSB instance, for the further DSB
- * operations.
- *
- * Returns: address of Intel_dsb instance requested for.
- * Failure: Returns the same DSB instance, but without a command buffer.
- */
-
-struct intel_dsb *
-intel_dsb_get(struct intel_crtc *crtc)
-{
-	struct drm_device *dev = crtc->base.dev;
-	struct drm_i915_private *i915 = to_i915(dev);
-	struct intel_dsb *dsb = &crtc->dsb;
-	struct drm_i915_gem_object *obj;
-	struct i915_vma *vma;
-	u32 *buf;
-	intel_wakeref_t wakeref;
-
-	if (!HAS_DSB(i915))
-		return dsb;
-
-	if (dsb->refcount++ != 0)
-		return dsb;
-
-	wakeref = intel_runtime_pm_get(&i915->runtime_pm);
-
-	obj = i915_gem_object_create_internal(i915, DSB_BUF_SIZE);
-	if (IS_ERR(obj)) {
-		drm_err(&i915->drm, "Gem object creation failed\n");
-		goto out;
-	}
-
-	vma = i915_gem_object_ggtt_pin(obj, NULL, 0, 0, 0);
-	if (IS_ERR(vma)) {
-		drm_err(&i915->drm, "Vma creation failed\n");
-		i915_gem_object_put(obj);
-		goto out;
-	}
-
-	buf = i915_gem_object_pin_map(vma->obj, I915_MAP_WC);
-	if (IS_ERR(buf)) {
-		drm_err(&i915->drm, "Command buffer creation failed\n");
-		goto out;
-	}
-
-	dsb->id = DSB1;
-	dsb->vma = vma;
-	dsb->cmd_buf = buf;
-
-out:
-	/*
-	 * On error dsb->cmd_buf will continue to be NULL, making the writes
-	 * pass-through. Leave the dangling ref to be removed later by the
-	 * corresponding intel_dsb_put(): the important error message will
-	 * already be logged above.
-	 */
-
-	intel_runtime_pm_put(&i915->runtime_pm, wakeref);
-
-	return dsb;
-}
-
-/**
- * intel_dsb_put() - To destroy DSB context.
- * @dsb: intel_dsb structure.
- *
- * This function destroys the DSB context allocated by a dsb_get(), by
- * unpinning and releasing the VMA object associated with it.
- */
-
-void intel_dsb_put(struct intel_dsb *dsb)
-{
-	struct intel_crtc *crtc = container_of(dsb, typeof(*crtc), dsb);
-	struct drm_i915_private *i915 = to_i915(crtc->base.dev);
-
-	if (!HAS_DSB(i915))
-		return;
-
-	if (drm_WARN_ON(&i915->drm, dsb->refcount == 0))
-		return;
-
-	if (--dsb->refcount == 0) {
-		i915_vma_unpin_and_release(&dsb->vma, I915_VMA_RELEASE_MAP);
-		dsb->cmd_buf = NULL;
-		dsb->free_pos = 0;
-		dsb->ins_start_offset = 0;
-	}
-}
-
 /**
  * intel_dsb_indexed_reg_write() -Write to the DSB context for auto
  * increment register.
@@ -192,7 +105,9 @@ void intel_dsb_put(struct intel_dsb *dsb)
 void intel_dsb_indexed_reg_write(struct intel_dsb *dsb, i915_reg_t reg,
 				 u32 val)
 {
-	struct intel_crtc *crtc = container_of(dsb, typeof(*crtc), dsb);
+	struct intel_crtc_state *crtc_state =
+		container_of(dsb, typeof(*crtc_state), dsb);
+	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
 	u32 *buf = dsb->cmd_buf;
 	u32 reg_val;
@@ -267,7 +182,9 @@ void intel_dsb_indexed_reg_write(struct intel_dsb *dsb, i915_reg_t reg,
  */
 void intel_dsb_reg_write(struct intel_dsb *dsb, i915_reg_t reg, u32 val)
 {
-	struct intel_crtc *crtc = container_of(dsb, typeof(*crtc), dsb);
+	struct intel_crtc_state *crtc_state =
+		container_of(dsb, typeof(*crtc_state), dsb);
+	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
 	u32 *buf = dsb->cmd_buf;
 
@@ -297,7 +214,9 @@ void intel_dsb_reg_write(struct intel_dsb *dsb, i915_reg_t reg, u32 val)
  */
 void intel_dsb_commit(struct intel_dsb *dsb)
 {
-	struct intel_crtc *crtc = container_of(dsb, typeof(*crtc), dsb);
+	struct intel_crtc_state *crtc_state =
+		container_of(dsb, typeof(*crtc_state), dsb);
+	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
 	struct drm_device *dev = crtc->base.dev;
 	struct drm_i915_private *dev_priv = to_i915(dev);
 	enum pipe pipe = crtc->pipe;
@@ -343,3 +262,87 @@ void intel_dsb_commit(struct intel_dsb *dsb)
 	dsb->ins_start_offset = 0;
 	intel_dsb_disable_engine(dsb);
 }
+
+/**
+ * intel_dsb_prepare() - Allocate, pin and map the DSB command buffer.
+ * @crtc_state: intel_crtc_state structure to prepare associated dsb instance.
+ *
+ * This function prepare the command buffer which is used to store dsb
+ * instructions with data.
+ */
+
+void intel_dsb_prepare(struct intel_crtc_state *crtc_state)
+{
+	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
+	struct drm_i915_private *i915 = to_i915(crtc->base.dev);
+	struct intel_dsb *dsb = &crtc_state->dsb;
+	struct drm_i915_gem_object *obj;
+	struct i915_vma *vma;
+	u32 *buf;
+	intel_wakeref_t wakeref;
+
+	if (!HAS_DSB(i915) || dsb->cmd_buf)
+		return;
+
+	wakeref = intel_runtime_pm_get(&i915->runtime_pm);
+
+	obj = i915_gem_object_create_internal(i915, DSB_BUF_SIZE);
+	if (IS_ERR(obj)) {
+		drm_err(&i915->drm, "Gem object creation failed\n");
+		goto out;
+	}
+
+	vma = i915_gem_object_ggtt_pin(obj, NULL, 0, 0, 0);
+	if (IS_ERR(vma)) {
+		drm_err(&i915->drm, "Vma creation failed\n");
+		i915_gem_object_put(obj);
+		goto out;
+	}
+
+	buf = i915_gem_object_pin_map(vma->obj, I915_MAP_WC);
+	if (IS_ERR(buf)) {
+		drm_err(&i915->drm, "Command buffer creation failed\n");
+		goto out;
+	}
+
+	dsb->id = DSB1;
+	dsb->vma = vma;
+	dsb->cmd_buf = buf;
+
+out:
+	/*
+	 * On error dsb->cmd_buf will continue to be NULL, making the writes
+	 * pass-through. Leave the dangling ref to be removed later by the
+	 * corresponding intel_dsb_put(): the important error message will
+	 * already be logged above.
+	 */
+
+	intel_runtime_pm_put(&i915->runtime_pm, wakeref);
+}
+
+/**
+ * intel_dsb_cleanup() - To cleanup DSB context.
+ * @crtc_state: intel_crtc_state structure to cleanup associated dsb instance.
+ *
+ * This function cleanup the DSB context by unpinning and releasing
+ * the VMA object associated with it.
+ */
+
+void intel_dsb_cleanup(struct intel_crtc_state *crtc_state)
+{
+	struct intel_dsb *dsb = &crtc_state->dsb;
+	struct i915_vma *p_vma;
+
+	if (dsb->vma) {
+		p_vma = fetch_and_zero(&dsb->vma);
+		if (p_vma) {
+			i915_vma_unpin(p_vma);
+			i915_gem_object_unpin_map(p_vma->obj);
+			i915_gem_object_put(p_vma->obj);
+		}
+		dsb->vma = NULL;
+		dsb->cmd_buf = NULL;
+		dsb->free_pos = 0;
+		dsb->ins_start_offset = 0;
+	}
+}
diff --git a/drivers/gpu/drm/i915/display/intel_dsb.h b/drivers/gpu/drm/i915/display/intel_dsb.h
index 395ef9ce558e..3a20a4388b9a 100644
--- a/drivers/gpu/drm/i915/display/intel_dsb.h
+++ b/drivers/gpu/drm/i915/display/intel_dsb.h
@@ -10,7 +10,7 @@
 
 #include "i915_reg.h"
 
-struct intel_crtc;
+struct intel_crtc_state;
 struct i915_vma;
 
 enum dsb_id {
@@ -22,7 +22,6 @@ enum dsb_id {
 };
 
 struct intel_dsb {
-	long refcount;
 	enum dsb_id id;
 	u32 *cmd_buf;
 	struct i915_vma *vma;
@@ -41,9 +40,8 @@ struct intel_dsb {
 	u32 ins_start_offset;
 };
 
-struct intel_dsb *
-intel_dsb_get(struct intel_crtc *crtc);
-void intel_dsb_put(struct intel_dsb *dsb);
+void intel_dsb_prepare(struct intel_crtc_state *crtc_state);
+void intel_dsb_cleanup(struct intel_crtc_state *crtc_state);
 void intel_dsb_reg_write(struct intel_dsb *dsb, i915_reg_t reg, u32 val);
 void intel_dsb_indexed_reg_write(struct intel_dsb *dsb, i915_reg_t reg,
 				 u32 val);
-- 
2.26.0



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