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path: root/drivers/gpu/drm/i915/display/intel_frontbuffer.c
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Diffstat (limited to 'drivers/gpu/drm/i915/display/intel_frontbuffer.c')
-rw-r--r--drivers/gpu/drm/i915/display/intel_frontbuffer.c199
1 files changed, 199 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/display/intel_frontbuffer.c b/drivers/gpu/drm/i915/display/intel_frontbuffer.c
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index 000000000000..44273c10cea5
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+++ b/drivers/gpu/drm/i915/display/intel_frontbuffer.c
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+/*
+ * 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 GEM tracks frontbuffers using a bitmask for all possible
+ * frontbuffer slots through i915_gem_track_fb(). The function 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_drv.h"
+#include "intel_fbc.h"
+#include "intel_frontbuffer.h"
+#include "intel_psr.h"
+
+void __intel_fb_obj_invalidate(struct drm_i915_gem_object *obj,
+ enum fb_op_origin origin,
+ unsigned int frontbuffer_bits)
+{
+ struct drm_i915_private *dev_priv = to_i915(obj->base.dev);
+
+ if (origin == ORIGIN_CS) {
+ spin_lock(&dev_priv->fb_tracking.lock);
+ dev_priv->fb_tracking.busy_bits |= frontbuffer_bits;
+ dev_priv->fb_tracking.flip_bits &= ~frontbuffer_bits;
+ spin_unlock(&dev_priv->fb_tracking.lock);
+ }
+
+ might_sleep();
+ intel_psr_invalidate(dev_priv, frontbuffer_bits, origin);
+ intel_edp_drrs_invalidate(dev_priv, frontbuffer_bits);
+ intel_fbc_invalidate(dev_priv, frontbuffer_bits, origin);
+}
+
+/**
+ * intel_frontbuffer_flush - flush frontbuffer
+ * @dev_priv: 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 intel_frontbuffer_flush(struct drm_i915_private *dev_priv,
+ unsigned frontbuffer_bits,
+ enum fb_op_origin origin)
+{
+ /* Delay flushing when rings are still busy.*/
+ spin_lock(&dev_priv->fb_tracking.lock);
+ frontbuffer_bits &= ~dev_priv->fb_tracking.busy_bits;
+ spin_unlock(&dev_priv->fb_tracking.lock);
+
+ if (!frontbuffer_bits)
+ return;
+
+ might_sleep();
+ intel_edp_drrs_flush(dev_priv, frontbuffer_bits);
+ intel_psr_flush(dev_priv, frontbuffer_bits, origin);
+ intel_fbc_flush(dev_priv, frontbuffer_bits, origin);
+}
+
+void __intel_fb_obj_flush(struct drm_i915_gem_object *obj,
+ enum fb_op_origin origin,
+ unsigned int frontbuffer_bits)
+{
+ struct drm_i915_private *dev_priv = to_i915(obj->base.dev);
+
+ if (origin == ORIGIN_CS) {
+ spin_lock(&dev_priv->fb_tracking.lock);
+ /* Filter out new bits since rendering started. */
+ frontbuffer_bits &= dev_priv->fb_tracking.busy_bits;
+ dev_priv->fb_tracking.busy_bits &= ~frontbuffer_bits;
+ spin_unlock(&dev_priv->fb_tracking.lock);
+ }
+
+ if (frontbuffer_bits)
+ intel_frontbuffer_flush(dev_priv, frontbuffer_bits, origin);
+}
+
+/**
+ * intel_frontbuffer_flip_prepare - prepare asynchronous frontbuffer flip
+ * @dev_priv: 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 *dev_priv,
+ unsigned frontbuffer_bits)
+{
+ spin_lock(&dev_priv->fb_tracking.lock);
+ dev_priv->fb_tracking.flip_bits |= frontbuffer_bits;
+ /* Remove stale busy bits due to the old buffer. */
+ dev_priv->fb_tracking.busy_bits &= ~frontbuffer_bits;
+ spin_unlock(&dev_priv->fb_tracking.lock);
+}
+
+/**
+ * intel_frontbuffer_flip_complete - complete asynchronous frontbuffer flip
+ * @dev_priv: 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 *dev_priv,
+ unsigned frontbuffer_bits)
+{
+ spin_lock(&dev_priv->fb_tracking.lock);
+ /* Mask any cancelled flips. */
+ frontbuffer_bits &= dev_priv->fb_tracking.flip_bits;
+ dev_priv->fb_tracking.flip_bits &= ~frontbuffer_bits;
+ spin_unlock(&dev_priv->fb_tracking.lock);
+
+ if (frontbuffer_bits)
+ intel_frontbuffer_flush(dev_priv,
+ frontbuffer_bits, ORIGIN_FLIP);
+}
+
+/**
+ * intel_frontbuffer_flip - synchronous frontbuffer flip
+ * @dev_priv: 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 *dev_priv,
+ unsigned frontbuffer_bits)
+{
+ spin_lock(&dev_priv->fb_tracking.lock);
+ /* Remove stale busy bits due to the old buffer. */
+ dev_priv->fb_tracking.busy_bits &= ~frontbuffer_bits;
+ spin_unlock(&dev_priv->fb_tracking.lock);
+
+ intel_frontbuffer_flush(dev_priv, frontbuffer_bits, ORIGIN_FLIP);
+}