Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 317 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/display/intel_frontbuffer.c b/drivers/gpu/drm/i915/display/intel_frontbuffer.c
new file mode 100644
index 000000000..d898b370d
--- /dev/null
+++ b/drivers/gpu/drm/i915/display/intel_frontbuffer.c
@@ -0,0 +1,317 @@
+/*
+ * Copyright © 2014 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Authors:
+ *	Daniel Vetter <daniel.vetter@ffwll.ch>
+ */
+
+/**
+ * DOC: frontbuffer tracking
+ *
+ * Many features require us to track changes to the currently active
+ * frontbuffer, especially rendering targeted at the frontbuffer.
+ *
+ * To be able to do so we track frontbuffers using a bitmask for all possible
+ * frontbuffer slots through intel_frontbuffer_track(). The functions in this
+ * file are then called when the contents of the frontbuffer are invalidated,
+ * when frontbuffer rendering has stopped again to flush out all the changes
+ * and when the frontbuffer is exchanged with a flip. Subsystems interested in
+ * frontbuffer changes (e.g. PSR, FBC, DRRS) should directly put their callbacks
+ * into the relevant places and filter for the frontbuffer slots that they are
+ * interested int.
+ *
+ * On a high level there are two types of powersaving features. The first one
+ * work like a special cache (FBC and PSR) and are interested when they should
+ * stop caching and when to restart caching. This is done by placing callbacks
+ * into the invalidate and the flush functions: At invalidate the caching must
+ * be stopped and at flush time it can be restarted. And maybe they need to know
+ * when the frontbuffer changes (e.g. when the hw doesn't initiate an invalidate
+ * and flush on its own) which can be achieved with placing callbacks into the
+ * flip functions.
+ *
+ * The other type of display power saving feature only cares about busyness
+ * (e.g. DRRS). In that case all three (invalidate, flush and flip) indicate
+ * busyness. There is no direct way to detect idleness. Instead an idle timer
+ * work delayed work should be started from the flush and flip functions and
+ * cancelled as soon as busyness is detected.
+ */
+
+#include "display/intel_dp.h"
+
+#include "i915_drv.h"
+#include "intel_display_types.h"
+#include "intel_fbc.h"
+#include "intel_frontbuffer.h"
+#include "intel_psr.h"
+
+/**
+ * frontbuffer_flush - flush frontbuffer
+ * @i915: i915 device
+ * @frontbuffer_bits: frontbuffer plane tracking bits
+ * @origin: which operation caused the flush
+ *
+ * This function gets called every time rendering on the given planes has
+ * completed and frontbuffer caching can be started again. Flushes will get
+ * delayed if they're blocked by some outstanding asynchronous rendering.
+ *
+ * Can be called without any locks held.
+ */
+static void frontbuffer_flush(struct drm_i915_private *i915,
+			      unsigned int frontbuffer_bits,
+			      enum fb_op_origin origin)
+{
+	/* Delay flushing when rings are still busy.*/
+	spin_lock(&i915->fb_tracking.lock);
+	frontbuffer_bits &= ~i915->fb_tracking.busy_bits;
+	spin_unlock(&i915->fb_tracking.lock);
+
+	if (!frontbuffer_bits)
+		return;
+
+	might_sleep();
+	intel_edp_drrs_flush(i915, frontbuffer_bits);
+	intel_psr_flush(i915, frontbuffer_bits, origin);
+	intel_fbc_flush(i915, frontbuffer_bits, origin);
+}
+
+/**
+ * intel_frontbuffer_flip_prepare - prepare asynchronous frontbuffer flip
+ * @i915: i915 device
+ * @frontbuffer_bits: frontbuffer plane tracking bits
+ *
+ * This function gets called after scheduling a flip on @obj. The actual
+ * frontbuffer flushing will be delayed until completion is signalled with
+ * intel_frontbuffer_flip_complete. If an invalidate happens in between this
+ * flush will be cancelled.
+ *
+ * Can be called without any locks held.
+ */
+void intel_frontbuffer_flip_prepare(struct drm_i915_private *i915,
+				    unsigned frontbuffer_bits)
+{
+	spin_lock(&i915->fb_tracking.lock);
+	i915->fb_tracking.flip_bits |= frontbuffer_bits;
+	/* Remove stale busy bits due to the old buffer. */
+	i915->fb_tracking.busy_bits &= ~frontbuffer_bits;
+	spin_unlock(&i915->fb_tracking.lock);
+}
+
+/**
+ * intel_frontbuffer_flip_complete - complete asynchronous frontbuffer flip
+ * @i915: i915 device
+ * @frontbuffer_bits: frontbuffer plane tracking bits
+ *
+ * This function gets called after the flip has been latched and will complete
+ * on the next vblank. It will execute the flush if it hasn't been cancelled yet.
+ *
+ * Can be called without any locks held.
+ */
+void intel_frontbuffer_flip_complete(struct drm_i915_private *i915,
+				     unsigned frontbuffer_bits)
+{
+	spin_lock(&i915->fb_tracking.lock);
+	/* Mask any cancelled flips. */
+	frontbuffer_bits &= i915->fb_tracking.flip_bits;
+	i915->fb_tracking.flip_bits &= ~frontbuffer_bits;
+	spin_unlock(&i915->fb_tracking.lock);
+
+	if (frontbuffer_bits)
+		frontbuffer_flush(i915, frontbuffer_bits, ORIGIN_FLIP);
+}
+
+/**
+ * intel_frontbuffer_flip - synchronous frontbuffer flip
+ * @i915: i915 device
+ * @frontbuffer_bits: frontbuffer plane tracking bits
+ *
+ * This function gets called after scheduling a flip on @obj. This is for
+ * synchronous plane updates which will happen on the next vblank and which will
+ * not get delayed by pending gpu rendering.
+ *
+ * Can be called without any locks held.
+ */
+void intel_frontbuffer_flip(struct drm_i915_private *i915,
+			    unsigned frontbuffer_bits)
+{
+	spin_lock(&i915->fb_tracking.lock);
+	/* Remove stale busy bits due to the old buffer. */
+	i915->fb_tracking.busy_bits &= ~frontbuffer_bits;
+	spin_unlock(&i915->fb_tracking.lock);
+
+	frontbuffer_flush(i915, frontbuffer_bits, ORIGIN_FLIP);
+}
+
+void __intel_fb_invalidate(struct intel_frontbuffer *front,
+			   enum fb_op_origin origin,
+			   unsigned int frontbuffer_bits)
+{
+	struct drm_i915_private *i915 = to_i915(front->obj->base.dev);
+
+	if (origin == ORIGIN_CS) {
+		spin_lock(&i915->fb_tracking.lock);
+		i915->fb_tracking.busy_bits |= frontbuffer_bits;
+		i915->fb_tracking.flip_bits &= ~frontbuffer_bits;
+		spin_unlock(&i915->fb_tracking.lock);
+	}
+
+	might_sleep();
+	intel_psr_invalidate(i915, frontbuffer_bits, origin);
+	intel_edp_drrs_invalidate(i915, frontbuffer_bits);
+	intel_fbc_invalidate(i915, frontbuffer_bits, origin);
+}
+
+void __intel_fb_flush(struct intel_frontbuffer *front,
+		      enum fb_op_origin origin,
+		      unsigned int frontbuffer_bits)
+{
+	struct drm_i915_private *i915 = to_i915(front->obj->base.dev);
+
+	if (origin == ORIGIN_CS) {
+		spin_lock(&i915->fb_tracking.lock);
+		/* Filter out new bits since rendering started. */
+		frontbuffer_bits &= i915->fb_tracking.busy_bits;
+		i915->fb_tracking.busy_bits &= ~frontbuffer_bits;
+		spin_unlock(&i915->fb_tracking.lock);
+	}
+
+	if (frontbuffer_bits)
+		frontbuffer_flush(i915, frontbuffer_bits, origin);
+}
+
+static int frontbuffer_active(struct i915_active *ref)
+{
+	struct intel_frontbuffer *front =
+		container_of(ref, typeof(*front), write);
+
+	kref_get(&front->ref);
+	return 0;
+}
+
+__i915_active_call
+static void frontbuffer_retire(struct i915_active *ref)
+{
+	struct intel_frontbuffer *front =
+		container_of(ref, typeof(*front), write);
+
+	intel_frontbuffer_flush(front, ORIGIN_CS);
+	intel_frontbuffer_put(front);
+}
+
+static void frontbuffer_release(struct kref *ref)
+	__releases(&to_i915(front->obj->base.dev)->fb_tracking.lock)
+{
+	struct intel_frontbuffer *front =
+		container_of(ref, typeof(*front), ref);
+	struct drm_i915_gem_object *obj = front->obj;
+	struct i915_vma *vma;
+
+	spin_lock(&obj->vma.lock);
+	for_each_ggtt_vma(vma, obj)
+		vma->display_alignment = I915_GTT_MIN_ALIGNMENT;
+	spin_unlock(&obj->vma.lock);
+
+	RCU_INIT_POINTER(obj->frontbuffer, NULL);
+	spin_unlock(&to_i915(obj->base.dev)->fb_tracking.lock);
+
+	i915_active_fini(&front->write);
+
+	i915_gem_object_put(obj);
+	kfree_rcu(front, rcu);
+}
+
+struct intel_frontbuffer *
+intel_frontbuffer_get(struct drm_i915_gem_object *obj)
+{
+	struct drm_i915_private *i915 = to_i915(obj->base.dev);
+	struct intel_frontbuffer *front;
+
+	front = __intel_frontbuffer_get(obj);
+	if (front)
+		return front;
+
+	front = kmalloc(sizeof(*front), GFP_KERNEL);
+	if (!front)
+		return NULL;
+
+	front->obj = obj;
+	kref_init(&front->ref);
+	atomic_set(&front->bits, 0);
+	i915_active_init(&front->write,
+			 frontbuffer_active,
+			 i915_active_may_sleep(frontbuffer_retire));
+
+	spin_lock(&i915->fb_tracking.lock);
+	if (rcu_access_pointer(obj->frontbuffer)) {
+		kfree(front);
+		front = rcu_dereference_protected(obj->frontbuffer, true);
+		kref_get(&front->ref);
+	} else {
+		i915_gem_object_get(obj);
+		rcu_assign_pointer(obj->frontbuffer, front);
+	}
+	spin_unlock(&i915->fb_tracking.lock);
+
+	return front;
+}
+
+void intel_frontbuffer_put(struct intel_frontbuffer *front)
+{
+	kref_put_lock(&front->ref,
+		      frontbuffer_release,
+		      &to_i915(front->obj->base.dev)->fb_tracking.lock);
+}
+
+/**
+ * intel_frontbuffer_track - update frontbuffer tracking
+ * @old: current buffer for the frontbuffer slots
+ * @new: new buffer for the frontbuffer slots
+ * @frontbuffer_bits: bitmask of frontbuffer slots
+ *
+ * This updates the frontbuffer tracking bits @frontbuffer_bits by clearing them
+ * from @old and setting them in @new. Both @old and @new can be NULL.
+ */
+void intel_frontbuffer_track(struct intel_frontbuffer *old,
+			     struct intel_frontbuffer *new,
+			     unsigned int frontbuffer_bits)
+{
+	/*
+	 * Control of individual bits within the mask are guarded by
+	 * the owning plane->mutex, i.e. we can never see concurrent
+	 * manipulation of individual bits. But since the bitfield as a whole
+	 * is updated using RMW, we need to use atomics in order to update
+	 * the bits.
+	 */
+	BUILD_BUG_ON(INTEL_FRONTBUFFER_BITS_PER_PIPE * I915_MAX_PIPES >
+		     BITS_PER_TYPE(atomic_t));
+
+	if (old) {
+		drm_WARN_ON(old->obj->base.dev,
+			    !(atomic_read(&old->bits) & frontbuffer_bits));
+		atomic_andnot(frontbuffer_bits, &old->bits);
+	}
+
+	if (new) {
+		drm_WARN_ON(new->obj->base.dev,
+			    atomic_read(&new->bits) & frontbuffer_bits);
+		atomic_or(frontbuffer_bits, &new->bits);
+	}
+}