Commit b680c37a authored by Daniel Vetter's avatar Daniel Vetter

drm/i915: DocBook integration for frontbuffer tracking

I shouldn't ask everyone to do this and fail myself ...

This extracts all the frontbuffer tracking functions into
intel_frontbuffer.c, adds a DOC overview section and also adds the
missing kerneldoc for i915_gem_track_fb and also pulls it into the
same section for convenience.

v2: Don't forget about the header files.

v3: Oops, might check compilation next time around. To make my life
easier drop the increase_pllclock from set_base_atomic since really,
it doesn't matter if you see your Oops or kgdb with a tiny bit of lag.

v4: Try to better explain how to actually use this, requested by Paulo
on irc.

v5: Explain invalidate/flush a bit clearer.

v6: s/business/busyness/
Acked-by: default avatarPaulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Vandana Kannan <vandana.kannan@intel.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@intel.com>
parent 1893a71b
......@@ -3803,6 +3803,13 @@ int num_ioctls;</synopsis>
configuration change.
</para>
</sect2>
<sect2>
<title>Frontbuffer Tracking</title>
!Pdrivers/gpu/drm/i915/intel_frontbuffer.c frontbuffer tracking
!Idrivers/gpu/drm/i915/intel_frontbuffer.c
!Fdrivers/gpu/drm/i915/intel_drv.h intel_frontbuffer_flip
!Fdrivers/gpu/drm/i915/i915_gem.c i915_gem_track_fb
</sect2>
<sect2>
<title>Plane Configuration</title>
<para>
......
......@@ -43,6 +43,7 @@ i915-y += intel_renderstate_gen6.o \
# modesetting core code
i915-y += intel_bios.o \
intel_display.o \
intel_frontbuffer.o \
intel_modes.o \
intel_overlay.o \
intel_sideband.o \
......
......@@ -5077,6 +5077,15 @@ int i915_gem_open(struct drm_device *dev, struct drm_file *file)
return ret;
}
/**
* i915_gem_track_fb - update frontbuffer tracking
* old: current GEM buffer for the frontbuffer slots
* new: new GEM 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 i915_gem_track_fb(struct drm_i915_gem_object *old,
struct drm_i915_gem_object *new,
unsigned frontbuffer_bits)
......
......@@ -76,8 +76,6 @@ static const uint32_t intel_cursor_formats[] = {
#define DIV_ROUND_CLOSEST_ULL(ll, d) \
({ unsigned long long _tmp = (ll)+(d)/2; do_div(_tmp, d); _tmp; })
static void intel_increase_pllclock(struct drm_device *dev,
enum pipe pipe);
static void intel_crtc_update_cursor(struct drm_crtc *crtc, bool on);
static void i9xx_crtc_clock_get(struct intel_crtc *crtc,
......@@ -1138,8 +1136,8 @@ void assert_fdi_rx_pll(struct drm_i915_private *dev_priv,
state_string(state), state_string(cur_state));
}
static void assert_panel_unlocked(struct drm_i915_private *dev_priv,
enum pipe pipe)
void assert_panel_unlocked(struct drm_i915_private *dev_priv,
enum pipe pipe)
{
struct drm_device *dev = dev_priv->dev;
int pp_reg;
......@@ -2631,7 +2629,6 @@ intel_pipe_set_base_atomic(struct drm_crtc *crtc, struct drm_framebuffer *fb,
if (dev_priv->display.disable_fbc)
dev_priv->display.disable_fbc(dev);
intel_increase_pllclock(dev, to_intel_crtc(crtc)->pipe);
dev_priv->display.update_primary_plane(crtc, fb, x, y);
......@@ -8986,35 +8983,6 @@ struct drm_display_mode *intel_crtc_mode_get(struct drm_device *dev,
return mode;
}
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");
}
}
static void intel_decrease_pllclock(struct drm_crtc *crtc)
{
struct drm_device *dev = crtc->dev;
......@@ -9090,188 +9058,6 @@ void intel_mark_idle(struct drm_device *dev)
intel_runtime_pm_put(dev_priv);
}
/**
* 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_edp_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 oustanding 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_edp_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 (IS_BROADWELL(dev))
gen8_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 asnychronous 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;
mutex_unlock(&dev_priv->fb_tracking.lock);
}
/**
* intel_frontbuffer_flip_complete - complete asynchronous frontbuffer flush
* @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 fush if it hasn't been cancalled 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);
}
static void intel_crtc_destroy(struct drm_crtc *crtc)
{
struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
......
......@@ -801,11 +801,7 @@ void intel_ddi_clock_get(struct intel_encoder *encoder,
struct intel_crtc_config *pipe_config);
void intel_ddi_set_vc_payload_alloc(struct drm_crtc *crtc, bool state);
/* intel_display.c */
const char *intel_output_name(int output);
bool intel_has_pending_fb_unpin(struct drm_device *dev);
int intel_pch_rawclk(struct drm_device *dev);
void intel_mark_busy(struct drm_device *dev);
/* intel_frontbuffer.c */
void intel_fb_obj_invalidate(struct drm_i915_gem_object *obj,
struct intel_engine_cs *ring);
void intel_frontbuffer_flip_prepare(struct drm_device *dev,
......@@ -833,6 +829,13 @@ void intel_frontbuffer_flip(struct drm_device *dev,
}
void intel_fb_obj_flush(struct drm_i915_gem_object *obj, bool retire);
/* intel_display.c */
const char *intel_output_name(int output);
bool intel_has_pending_fb_unpin(struct drm_device *dev);
int intel_pch_rawclk(struct drm_device *dev);
void intel_mark_busy(struct drm_device *dev);
void intel_mark_idle(struct drm_device *dev);
void intel_crtc_restore_mode(struct drm_crtc *crtc);
void intel_crtc_control(struct drm_crtc *crtc, bool enable);
......@@ -891,6 +894,8 @@ struct intel_shared_dpll *intel_get_shared_dpll(struct intel_crtc *crtc);
void intel_put_shared_dpll(struct intel_crtc *crtc);
/* modesetting asserts */
void assert_panel_unlocked(struct drm_i915_private *dev_priv,
enum pipe pipe);
void assert_pll(struct drm_i915_private *dev_priv,
enum pipe pipe, bool state);
#define assert_pll_enabled(d, p) assert_pll(d, p, true)
......
/*
* 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 targetted 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 trackings 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_edp_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 oustanding 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_edp_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 (IS_BROADWELL(dev))
gen8_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 asnychronous 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;
mutex_unlock(&dev_priv->fb_tracking.lock);
}
/**
* intel_frontbuffer_flip_complete - complete asynchronous frontbuffer flush
* @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 fush if it hasn't been cancalled 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);
}
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