/*
* 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 <[email protected]>
*/
/**
* 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 "gem/i915_gem_object_frontbuffer.h"
#include "i915_active.h"
#include "i915_drv.h"
#include "intel_display_trace.h"
#include "intel_display_types.h"
#include "intel_dp.h"
#include "intel_drrs.h"
#include "intel_fbc.h"
#include "intel_frontbuffer.h"
#include "intel_psr.h"
#include "intel_tdf.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)
{
struct intel_display *display = &i915->display;
/* Delay flushing when rings are still busy.*/
spin_lock(&i915->display.fb_tracking.lock);
frontbuffer_bits &= ~i915->display.fb_tracking.busy_bits;
spin_unlock(&i915->display.fb_tracking.lock);
if (!frontbuffer_bits)
return;
trace_intel_frontbuffer_flush(i915, frontbuffer_bits, origin);
might_sleep();
intel_td_flush(i915);
intel_drrs_flush(i915, frontbuffer_bits);
intel_psr_flush(display, 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->display.fb_tracking.lock);
i915->display.fb_tracking.flip_bits |= frontbuffer_bits;
/* Remove stale busy bits due to the old buffer. */
i915->display.fb_tracking.busy_bits &= ~frontbuffer_bits;
spin_unlock(&i915->display.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->display.fb_tracking.lock);
/* Mask any cancelled flips. */
frontbuffer_bits &= i915->display.fb_tracking.flip_bits;
i915->display.fb_tracking.flip_bits &= ~frontbuffer_bits;
spin_unlock(&i915->display.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->display.fb_tracking.lock);
/* Remove stale busy bits due to the old buffer. */
i915->display.fb_tracking.busy_bits &= ~frontbuffer_bits;
spin_unlock(&i915->display.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 = intel_bo_to_i915(front->obj);
struct intel_display *display = &i915->display;
if (origin == ORIGIN_CS) {
spin_lock(&i915->display.fb_tracking.lock);
i915->display.fb_tracking.busy_bits |= frontbuffer_bits;
i915->display.fb_tracking.flip_bits &= ~frontbuffer_bits;
spin_unlock(&i915->display.fb_tracking.lock);
}
trace_intel_frontbuffer_invalidate(i915, frontbuffer_bits, origin);
might_sleep();
intel_psr_invalidate(display, frontbuffer_bits, origin);
intel_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 = intel_bo_to_i915(front->obj);
if (origin == ORIGIN_CS) {
spin_lock(&i915->display.fb_tracking.lock);
/* Filter out new bits since rendering started. */
frontbuffer_bits &= i915->display.fb_tracking.busy_bits;
i915->display.fb_tracking.busy_bits &= ~frontbuffer_bits;
spin_unlock(&i915->display.fb_tracking.lock);
}
if (frontbuffer_bits)
frontbuffer_flush(i915, frontbuffer_bits, origin);
}
static void intel_frontbuffer_flush_work(struct work_struct *work)
{
struct intel_frontbuffer *front =
container_of(work, struct intel_frontbuffer, flush_work);
i915_gem_object_flush_if_display(front->obj);
intel_frontbuffer_flush(front, ORIGIN_DIRTYFB);
intel_frontbuffer_put(front);
}
/**
* intel_frontbuffer_queue_flush - queue flushing frontbuffer object
* @front: GEM object to flush
*
* This function is targeted for our dirty callback for queueing flush when
* dma fence is signales
*/
void intel_frontbuffer_queue_flush(struct intel_frontbuffer *front)
{
if (!front)
return;
kref_get(&front->ref);
if (!schedule_work(&front->flush_work))
intel_frontbuffer_put(front);
}
static int frontbuffer_active(struct i915_active *ref)
{
struct intel_frontbuffer *front =
container_of(ref, typeof(*front), write);
kref_get(&front->ref);
return 0;
}
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(&intel_bo_to_i915(front->obj)->display.fb_tracking.lock)
{
struct intel_frontbuffer *ret, *front =
container_of(ref, typeof(*front), ref);
struct drm_i915_gem_object *obj = front->obj;
drm_WARN_ON(&intel_bo_to_i915(obj)->drm, atomic_read(&front->bits));
i915_ggtt_clear_scanout(obj);
ret = i915_gem_object_set_frontbuffer(obj, NULL);
drm_WARN_ON(&intel_bo_to_i915(obj)->drm, ret);
spin_unlock(&intel_bo_to_i915(obj)->display.fb_tracking.lock);
i915_active_fini(&front->write);
kfree_rcu(front, rcu);
}
struct intel_frontbuffer *
intel_frontbuffer_get(struct drm_i915_gem_object *obj)
{
struct drm_i915_private *i915 = intel_bo_to_i915(obj);
struct intel_frontbuffer *front, *cur;
front = i915_gem_object_get_frontbuffer(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,
frontbuffer_retire,
I915_ACTIVE_RETIRE_SLEEPS);
INIT_WORK(&front->flush_work, intel_frontbuffer_flush_work);
spin_lock(&i915->display.fb_tracking.lock);
cur = i915_gem_object_set_frontbuffer(obj, front);
spin_unlock(&i915->display.fb_tracking.lock);
if (cur != front)
kfree(front);
return cur;
}
void intel_frontbuffer_put(struct intel_frontbuffer *front)
{
kref_put_lock(&front->ref,
frontbuffer_release,
&intel_bo_to_i915(front->obj)->display.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));
BUILD_BUG_ON(INTEL_FRONTBUFFER_BITS_PER_PIPE * I915_MAX_PIPES > 32);
BUILD_BUG_ON(I915_MAX_PLANES > INTEL_FRONTBUFFER_BITS_PER_PIPE);
if (old) {
drm_WARN_ON(&intel_bo_to_i915(old->obj)->drm,
!(atomic_read(&old->bits) & frontbuffer_bits));
atomic_andnot(frontbuffer_bits, &old->bits);
}
if (new) {
drm_WARN_ON(&intel_bo_to_i915(new->obj)->drm,
atomic_read(&new->bits) & frontbuffer_bits);
atomic_or(frontbuffer_bits, &new->bits);
}
}
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