diff options
Diffstat (limited to 'drivers/gpu/drm/i915/intel_frontbuffer.c')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_frontbuffer.c | 279 |
1 files changed, 279 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/intel_frontbuffer.c b/drivers/gpu/drm/i915/intel_frontbuffer.c new file mode 100644 index 000000000000..79f6d72179c5 --- /dev/null +++ b/drivers/gpu/drm/i915/intel_frontbuffer.c @@ -0,0 +1,279 @@ +/* + * 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); +} |