/*
* 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.
*
* Note that there's also an older frontbuffer activity tracking scheme which
* just tracks general activity. This is done by the various mark_busy and
* mark_idle functions. For display power management features using these
* functions is deprecated and should be avoided.
*/
#include <drm/drmP.h>
#include "intel_drv.h"
#include "i915_drv.h"
static void intel_increase_pllclock(struct drm_device *dev,
enum pipe pipe)
{
struct drm_i915_private *dev_priv = dev->dev_private;
int dpll_reg = DPLL(pipe);
int dpll;
if (!HAS_GMCH_DISPLAY(dev))
return;
if (!dev_priv->lvds_downclock_avail)
return;
dpll = I915_READ(dpll_reg);
if (!HAS_PIPE_CXSR(dev) && (dpll & DISPLAY_RATE_SELECT_FPA1)) {
DRM_DEBUG_DRIVER("upclocking LVDS\n");
assert_panel_unlocked(dev_priv, pipe);
dpll &= ~DISPLAY_RATE_SELECT_FPA1;
I915_WRITE(dpll_reg, dpll);
intel_wait_for_vblank(dev, pipe);
dpll = I915_READ(dpll_reg);
if (dpll & DISPLAY_RATE_SELECT_FPA1)
DRM_DEBUG_DRIVER("failed to upclock LVDS!\n");
}
}
/**
* intel_mark_fb_busy - mark given planes as busy
* @dev: DRM device
* @frontbuffer_bits: bits for the affected planes
* @ring: optional ring for asynchronous commands
*
* This function gets called every time the screen contents change. It can be
* used to keep e.g. the update rate at the nominal refresh rate with DRRS.
*/
static void intel_mark_fb_busy(struct drm_device *dev,
unsigned frontbuffer_bits,
struct intel_engine_cs *ring)
{
struct drm_i915_private *dev_priv = dev->dev_private;
enum pipe pipe;
if (!i915.powersave)
return;
for_each_pipe(dev_priv, pipe) {
if (!(frontbuffer_bits & INTEL_FRONTBUFFER_ALL_MASK(pipe)))
continue;
intel_increase_pllclock(dev, pipe);
if (ring && intel_fbc_enabled(dev))
ring->fbc_dirty = true;
}
}
/**
* intel_fb_obj_invalidate - invalidate frontbuffer object
* @obj: GEM object to invalidate
* @ring: set for asynchronous rendering
*
* This function gets called every time rendering on the given object starts and
* frontbuffer caching (fbc, low refresh rate for DRRS, panel self refresh) must
* be invalidated. If @ring is non-NULL any subsequent invalidation will be delayed
* until the rendering completes or a flip on this frontbuffer plane is
* scheduled.
*/
void intel_fb_obj_invalidate(struct drm_i915_gem_object *obj,
struct intel_engine_cs *ring)
{
struct drm_device *dev = obj->base.dev;
struct drm_i915_private *dev_priv = dev->dev_private;
WARN_ON(!mutex_is_locked(&dev->struct_mutex));
if (!obj->frontbuffer_bits)
return;
if (ring) {
mutex_lock(&dev_priv->fb_tracking.lock);
dev_priv->fb_tracking.busy_bits
|= obj->frontbuffer_bits;
dev_priv->fb_tracking.flip_bits
&= ~obj->frontbuffer_bits;
mutex_unlock(&dev_priv->fb_tracking.lock);
}
intel_mark_fb_busy(dev, obj->frontbuffer_bits, ring);
intel_psr_invalidate(dev, obj->frontbuffer_bits);
}
/**
* intel_frontbuffer_flush - flush frontbuffer
* @dev: DRM device
* @frontbuffer_bits: frontbuffer plane tracking bits
*
* 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.
*/
void intel_frontbuffer_flush(struct drm_device *dev,
unsigned frontbuffer_bits)
{
struct drm_i915_private *dev_priv = dev->dev_private;
/* Delay flushing when rings are still busy.*/
mutex_lock(&dev_priv->fb_tracking.lock);
frontbuffer_bits &= ~dev_priv->fb_tracking.busy_bits;
mutex_unlock(&dev_priv->fb_tracking.lock);
intel_mark_fb_busy(dev, frontbuffer_bits, NULL);
intel_psr_flush(dev, frontbuffer_bits);
/*
* FIXME: Unconditional fbc flushing here is a rather gross hack and
* needs to be reworked into a proper frontbuffer tracking scheme like
* psr employs.
*/
if (dev_priv->fbc.need_sw_cache_clean) {
dev_priv->fbc.need_sw_cache_clean = false;
bdw_fbc_sw_flush(dev, FBC_REND_CACHE_CLEAN);
}
}
/**
* intel_fb_obj_flush - flush frontbuffer object
* @obj: GEM object to flush
* @retire: set when retiring asynchronous rendering
*
* This function gets called every time rendering on the given object has
* completed and frontbuffer caching can be started again. If @retire is true
* then any delayed flushes will be unblocked.
*/
void intel_fb_obj_flush(struct drm_i915_gem_object *obj,
bool retire)
{
struct drm_device *dev = obj->base.dev;
struct drm_i915_private *dev_priv = dev->dev_private;
unsigned frontbuffer_bits;
WARN_ON(!mutex_is_locked(&dev->struct_mutex));
if (!obj->frontbuffer_bits)
return;
frontbuffer_bits = obj->frontbuffer_bits;
if (retire) {
mutex_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;
mutex_unlock(&dev_priv->fb_tracking.lock);
}
intel_frontbuffer_flush(dev, frontbuffer_bits);
}
/**
* intel_frontbuffer_flip_prepare - prepare asynchronous frontbuffer flip
* @dev: DRM 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_device *dev,
unsigned frontbuffer_bits)
{
struct drm_i915_private *dev_priv = dev->dev_private;
mutex_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;
mutex_unlock(&dev_priv->fb_tracking.lock);
}
/**
* intel_frontbuffer_flip_complete - complete asynchronous frontbuffer flip
* @dev: DRM 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_device *dev,
unsigned frontbuffer_bits)
{
struct drm_i915_private *dev_priv = dev->dev_private;
mutex_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;
mutex_unlock(&dev_priv->fb_tracking.lock);
intel_frontbuffer_flush(dev, frontbuffer_bits);
}