[Intel-gfx] [PATCH v4 02/10] drm/i915/dsb: DSB context creation.

[Animesh Manna]

This patch adds a function, which will internally get the gem buffer
for DSB engine. The GEM buffer is from global GTT, and is mapped into
CPU domain, contains the data + opcode to be feed to DSB engine.

v1: Initial version.

v2:
- removed some unwanted code. (Chris)
- Used i915_gem_object_create_internal instead of _shmem. (Chris)
- cmd_buf_tail removed and can be derived through vma object. (Chris)

v3: vma realeased if i915_gem_object_pin_map() failed. (Shashank)

Cc: Imre Deak <imre.deak at intel.com>
Cc: Michel Thierry <michel.thierry 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/Makefile                 |  1 +
 .../drm/i915/display/intel_display_types.h    |  3 +
 drivers/gpu/drm/i915/display/intel_dsb.c      | 83 +++++++++++++++++++
 drivers/gpu/drm/i915/display/intel_dsb.h      | 31 +++++++
 drivers/gpu/drm/i915/i915_drv.h               |  1 +
 5 files changed, 119 insertions(+)
 create mode 100644 drivers/gpu/drm/i915/display/intel_dsb.c
 create mode 100644 drivers/gpu/drm/i915/display/intel_dsb.h

diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
index 658b930d34a8..6313e7b4bd78 100644
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -172,6 +172,7 @@ i915-y += \
 	display/intel_display_power.o \
 	display/intel_dpio_phy.o \
 	display/intel_dpll_mgr.o \
+	display/intel_dsb.o \
 	display/intel_fbc.o \
 	display/intel_fifo_underrun.o \
 	display/intel_frontbuffer.o \
diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index 61277a87dbe7..da36867189cb 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -1033,6 +1033,9 @@ struct intel_crtc {
 
 	/* scalers available on this crtc */
 	int num_scalers;
+
+	/* per pipe DSB related info */
+	struct intel_dsb dsb[MAX_DSB_PER_PIPE];
 };
 
 struct intel_plane {
diff --git a/drivers/gpu/drm/i915/display/intel_dsb.c b/drivers/gpu/drm/i915/display/intel_dsb.c
new file mode 100644
index 000000000000..007ef13481d5
--- /dev/null
+++ b/drivers/gpu/drm/i915/display/intel_dsb.c
@@ -0,0 +1,83 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2019 Intel Corporation
+ *
+ */
+
+#include "i915_drv.h"
+#include "intel_display_types.h"
+
+#define DSB_BUF_SIZE    (2 * PAGE_SIZE)
+
+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 drm_i915_gem_object *obj;
+	struct i915_vma *vma;
+	struct intel_dsb *dsb;
+	intel_wakeref_t wakeref;
+	int i;
+
+	for (i = 0; i < MAX_DSB_PER_PIPE; i++)
+		if (!crtc->dsb[i].cmd_buf)
+			break;
+
+	if (WARN_ON(i == MAX_DSB_PER_PIPE))
+		return NULL;
+
+	dsb = &crtc->dsb[i];
+	dsb->id = i;
+	dsb->crtc = crtc;
+	if (!HAS_DSB(i915))
+		return dsb;
+
+	wakeref = intel_runtime_pm_get(&i915->runtime_pm);
+
+	obj = i915_gem_object_create_internal(i915, DSB_BUF_SIZE);
+	if (IS_ERR(obj))
+		goto err;
+
+	mutex_lock(&i915->drm.struct_mutex);
+	vma = i915_gem_object_ggtt_pin(obj, NULL, 0, 0, PIN_MAPPABLE);
+	mutex_unlock(&i915->drm.struct_mutex);
+	if (IS_ERR(vma)) {
+		DRM_ERROR("Vma creation failed.\n");
+		i915_gem_object_put(obj);
+		goto err;
+	}
+
+	dsb->cmd_buf = i915_gem_object_pin_map(vma->obj, I915_MAP_WC);
+	if (IS_ERR(dsb->cmd_buf)) {
+		DRM_ERROR("Command buffer creation failed.\n");
+		i915_vma_unpin_and_release(&vma, 0);
+		dsb->cmd_buf = NULL;
+		goto err;
+	}
+	dsb->vma = vma;
+
+err:
+	intel_runtime_pm_put(&i915->runtime_pm, wakeref);
+	return dsb;
+}
+
+void intel_dsb_put(struct intel_dsb *dsb)
+{
+	struct intel_crtc *crtc;
+	struct drm_i915_private *i915;
+
+	if (!dsb)
+		return;
+
+	crtc = dsb->crtc;
+	i915 = to_i915(crtc->base.dev);
+
+	if (dsb->cmd_buf) {
+		mutex_lock(&i915->drm.struct_mutex);
+		i915_gem_object_unpin_map(dsb->vma->obj);
+		i915_vma_unpin_and_release(&dsb->vma, 0);
+		dsb->cmd_buf = NULL;
+		mutex_unlock(&i915->drm.struct_mutex);
+	}
+}
diff --git a/drivers/gpu/drm/i915/display/intel_dsb.h b/drivers/gpu/drm/i915/display/intel_dsb.h
new file mode 100644
index 000000000000..4a4091cadc1e
--- /dev/null
+++ b/drivers/gpu/drm/i915/display/intel_dsb.h
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright © 2019 Intel Corporation
+ */
+
+#ifndef _INTEL_DSB_H
+#define _INTEL_DSB_H
+
+struct intel_crtc;
+struct i915_vma;
+
+enum dsb_id {
+	INVALID_DSB = -1,
+	DSB1,
+	DSB2,
+	DSB3,
+	MAX_DSB_PER_PIPE
+};
+
+struct intel_dsb {
+	struct intel_crtc *crtc;
+	enum dsb_id id;
+	u32 *cmd_buf;
+	struct i915_vma *vma;
+};
+
+struct intel_dsb *
+intel_dsb_get(struct intel_crtc *crtc);
+void intel_dsb_put(struct intel_dsb *dsb);
+
+#endif
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 804bfe7aec2b..7aa11e3dd413 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -67,6 +67,7 @@
 #include "display/intel_display.h"
 #include "display/intel_display_power.h"
 #include "display/intel_dpll_mgr.h"
+#include "display/intel_dsb.h"
 #include "display/intel_frontbuffer.h"
 #include "display/intel_gmbus.h"
 #include "display/intel_opregion.h"
-- 
2.22.0