Commit 25ad93fd authored by Paulo Zanoni's avatar Paulo Zanoni Committed by Daniel Vetter
Browse files

drm/i915: add the FBC mutex 



Make sure we're not going to have weird races in really weird cases
where a lot of different CRTCs are doing rendering and modesets at the
same time.

With this change and the stolen_lock from the previous patch, we can
start removing the struct_mutex locking we have around FBC in the next
patches.

v2:
 - Rebase (6 months later)
 - Also lock debugfs and stolen.
v3:
 - Don't lock a single value read (Chris).
 - Replace lockdep assertions with WARNs (Daniel).
 - Improve commit message.
 - Don't forget intel_pre_plane_update() locking.
v4:
 - Don't remove struct_mutex at intel_pre_plane_update() (Chris).
 - Add comment regarding locking dependencies (Chris).
 - Rebase after the stolen code rework.
 - Rebase again after drm-intel-nightly changes.
v5:
 - Rebase after the new stolen_lock patch.

Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v4)
Signed-off-by: default avatarPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
parent 92e97d2f

drivers/gpu/drm/i915/i915_debugfs.c

+4 −0
Original line number Diff line number Diff line
@@ -1633,6 +1633,7 @@ static int i915_fbc_status(struct seq_file *m, void *unused) 
	}



	intel_runtime_pm_get(dev_priv);

	mutex_lock(&dev_priv->fbc.lock);



	if (intel_fbc_enabled(dev))

		seq_puts(m, "FBC enabled\n");
@@ -1645,6 +1646,7 @@ static int i915_fbc_status(struct seq_file *m, void *unused) 
			   yesno(I915_READ(FBC_STATUS2) &

				 FBC_COMPRESSION_MASK));



	mutex_unlock(&dev_priv->fbc.lock);

	intel_runtime_pm_put(dev_priv);



	return 0;
@@ -1675,6 +1677,7 @@ static int i915_fbc_fc_set(void *data, u64 val) 
		return -ENODEV;



	drm_modeset_lock_all(dev);

	mutex_lock(&dev_priv->fbc.lock);



	reg = I915_READ(ILK_DPFC_CONTROL);

	dev_priv->fbc.false_color = val;
@@ -1683,6 +1686,7 @@ static int i915_fbc_fc_set(void *data, u64 val) 
		   (reg | FBC_CTL_FALSE_COLOR) :

		   (reg & ~FBC_CTL_FALSE_COLOR));



	mutex_unlock(&dev_priv->fbc.lock);

	drm_modeset_unlock_all(dev);

	return 0;

}

drivers/gpu/drm/i915/i915_drv.h

+3 −0
Original line number Diff line number Diff line
@@ -899,6 +899,9 @@ enum fb_op_origin { 
};



struct i915_fbc {

	/* This is always the inner lock when overlapping with struct_mutex and

	 * it's the outer lock when overlapping with stolen_lock. */

	struct mutex lock;

	unsigned long uncompressed_size;

	unsigned threshold;

	unsigned int fb_id;

drivers/gpu/drm/i915/intel_display.c

+2 −4
Original line number Diff line number Diff line
@@ -4783,11 +4783,9 @@ static void intel_pre_plane_update(struct intel_crtc *crtc) 
	if (atomic->wait_for_flips)

		intel_crtc_wait_for_pending_flips(&crtc->base);



	if (atomic->disable_fbc &&

	    dev_priv->fbc.crtc == crtc) {

	if (atomic->disable_fbc) {

		mutex_lock(&dev->struct_mutex);

		if (dev_priv->fbc.crtc == crtc)

			intel_fbc_disable(dev);

		intel_fbc_disable_crtc(crtc);

		mutex_unlock(&dev->struct_mutex);

	}

drivers/gpu/drm/i915/intel_drv.h

+1 −0
Original line number Diff line number Diff line
@@ -1252,6 +1252,7 @@ bool intel_fbc_enabled(struct drm_device *dev); 
void intel_fbc_update(struct drm_device *dev);

void intel_fbc_init(struct drm_i915_private *dev_priv);

void intel_fbc_disable(struct drm_device *dev);

void intel_fbc_disable_crtc(struct intel_crtc *crtc);

void intel_fbc_invalidate(struct drm_i915_private *dev_priv,

			  unsigned int frontbuffer_bits,

			  enum fb_op_origin origin);

drivers/gpu/drm/i915/intel_fbc.c

+86 −15
Original line number Diff line number Diff line
@@ -336,6 +336,7 @@ static void intel_fbc_work_fn(struct work_struct *__work) 
	struct drm_i915_private *dev_priv = dev->dev_private;



	mutex_lock(&dev->struct_mutex);

	mutex_lock(&dev_priv->fbc.lock);

	if (work == dev_priv->fbc.fbc_work) {

		/* Double check that we haven't switched fb without cancelling

		 * the prior work.
@@ -350,6 +351,7 @@ static void intel_fbc_work_fn(struct work_struct *__work) 


		dev_priv->fbc.fbc_work = NULL;

	}

	mutex_unlock(&dev_priv->fbc.lock);

	mutex_unlock(&dev->struct_mutex);



	kfree(work);
@@ -357,6 +359,8 @@ static void intel_fbc_work_fn(struct work_struct *__work) 


static void intel_fbc_cancel_work(struct drm_i915_private *dev_priv)

{

	WARN_ON(!mutex_is_locked(&dev_priv->fbc.lock));



	if (dev_priv->fbc.fbc_work == NULL)

		return;
@@ -384,6 +388,8 @@ static void intel_fbc_enable(struct drm_crtc *crtc) 
	struct drm_device *dev = crtc->dev;

	struct drm_i915_private *dev_priv = dev->dev_private;



	WARN_ON(!mutex_is_locked(&dev_priv->fbc.lock));



	if (!dev_priv->display.enable_fbc)

		return;
@@ -418,6 +424,21 @@ static void intel_fbc_enable(struct drm_crtc *crtc) 
	schedule_delayed_work(&work->work, msecs_to_jiffies(50));

}



static void __intel_fbc_disable(struct drm_device *dev)

{

	struct drm_i915_private *dev_priv = dev->dev_private;



	WARN_ON(!mutex_is_locked(&dev_priv->fbc.lock));



	intel_fbc_cancel_work(dev_priv);



	if (!dev_priv->display.disable_fbc)

		return;



	dev_priv->display.disable_fbc(dev);

	dev_priv->fbc.crtc = NULL;

}



/**

 * intel_fbc_disable - disable FBC

 * @dev: the drm_device
@@ -428,13 +449,26 @@ void intel_fbc_disable(struct drm_device *dev) 
{

	struct drm_i915_private *dev_priv = dev->dev_private;



	intel_fbc_cancel_work(dev_priv);

	mutex_lock(&dev_priv->fbc.lock);

	__intel_fbc_disable(dev);

	mutex_unlock(&dev_priv->fbc.lock);

}



	if (!dev_priv->display.disable_fbc)

		return;

/*

 * intel_fbc_disable_crtc - disable FBC if it's associated with crtc

 * @crtc: the CRTC

 *

 * This function disables FBC if it's associated with the provided CRTC.

 */

void intel_fbc_disable_crtc(struct intel_crtc *crtc)

{

	struct drm_device *dev = crtc->base.dev;

	struct drm_i915_private *dev_priv = dev->dev_private;



	dev_priv->display.disable_fbc(dev);

	dev_priv->fbc.crtc = NULL;

	mutex_lock(&dev_priv->fbc.lock);

	if (dev_priv->fbc.crtc == crtc)

		__intel_fbc_disable(dev);

	mutex_unlock(&dev_priv->fbc.lock);

}



const char *intel_no_fbc_reason_str(enum no_fbc_reason reason)
@@ -607,7 +641,7 @@ err_llb: 
	return -ENOSPC;

}



void intel_fbc_cleanup_cfb(struct drm_device *dev)

static void __intel_fbc_cleanup_cfb(struct drm_device *dev)

{

	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -625,6 +659,15 @@ void intel_fbc_cleanup_cfb(struct drm_device *dev) 
	dev_priv->fbc.uncompressed_size = 0;

}



void intel_fbc_cleanup_cfb(struct drm_device *dev)

{

	struct drm_i915_private *dev_priv = dev->dev_private;



	mutex_lock(&dev_priv->fbc.lock);

	__intel_fbc_cleanup_cfb(dev);

	mutex_unlock(&dev_priv->fbc.lock);

}



static int intel_fbc_setup_cfb(struct drm_device *dev, int size, int fb_cpp)

{

	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -633,13 +676,13 @@ static int intel_fbc_setup_cfb(struct drm_device *dev, int size, int fb_cpp) 
		return 0;



	/* Release any current block */

	intel_fbc_cleanup_cfb(dev);

	__intel_fbc_cleanup_cfb(dev);



	return intel_fbc_alloc_cfb(dev, size, fb_cpp);

}



/**

 * intel_fbc_update - enable/disable FBC as needed

 * __intel_fbc_update - enable/disable FBC as needed, unlocked

 * @dev: the drm_device

 *

 * Set up the framebuffer compression hardware at mode set time.  We
@@ -657,7 +700,7 @@ static int intel_fbc_setup_cfb(struct drm_device *dev, int size, int fb_cpp) 
 *

 * We need to enable/disable FBC on a global basis.

 */

void intel_fbc_update(struct drm_device *dev)

static void __intel_fbc_update(struct drm_device *dev)

{

	struct drm_i915_private *dev_priv = dev->dev_private;

	struct drm_crtc *crtc = NULL;
@@ -670,6 +713,8 @@ void intel_fbc_update(struct drm_device *dev) 
	if (!HAS_FBC(dev))

		return;



	WARN_ON(!mutex_is_locked(&dev_priv->fbc.lock));



	/* disable framebuffer compression in vGPU */

	if (intel_vgpu_active(dev))

		i915.enable_fbc = 0;
@@ -788,7 +833,7 @@ void intel_fbc_update(struct drm_device *dev) 
		 * some point. And we wait before enabling FBC anyway.

		 */

		DRM_DEBUG_KMS("disabling active FBC for update\n");

		intel_fbc_disable(dev);

		__intel_fbc_disable(dev);

	}



	intel_fbc_enable(crtc);
@@ -799,9 +844,24 @@ out_disable: 
	/* Multiple disables should be harmless */

	if (intel_fbc_enabled(dev)) {

		DRM_DEBUG_KMS("unsupported config, disabling FBC\n");

		intel_fbc_disable(dev);

		__intel_fbc_disable(dev);

	}

	__intel_fbc_cleanup_cfb(dev);

}

	intel_fbc_cleanup_cfb(dev);



/*

 * intel_fbc_update - enable/disable FBC as needed

 * @dev: the drm_device

 *

 * This function reevaluates the overall state and enables or disables FBC.

 */

void intel_fbc_update(struct drm_device *dev)

{

	struct drm_i915_private *dev_priv = dev->dev_private;



	mutex_lock(&dev_priv->fbc.lock);

	__intel_fbc_update(dev);

	mutex_unlock(&dev_priv->fbc.lock);

}



void intel_fbc_invalidate(struct drm_i915_private *dev_priv,
@@ -814,6 +874,8 @@ void intel_fbc_invalidate(struct drm_i915_private *dev_priv, 
	if (origin == ORIGIN_GTT)

		return;



	mutex_lock(&dev_priv->fbc.lock);



	if (dev_priv->fbc.enabled)

		fbc_bits = INTEL_FRONTBUFFER_PRIMARY(dev_priv->fbc.crtc->pipe);

	else if (dev_priv->fbc.fbc_work)
@@ -825,7 +887,9 @@ void intel_fbc_invalidate(struct drm_i915_private *dev_priv, 
	dev_priv->fbc.busy_bits |= (fbc_bits & frontbuffer_bits);



	if (dev_priv->fbc.busy_bits)

		intel_fbc_disable(dev);

		__intel_fbc_disable(dev);



	mutex_unlock(&dev_priv->fbc.lock);

}



void intel_fbc_flush(struct drm_i915_private *dev_priv,
@@ -833,13 +897,18 @@ void intel_fbc_flush(struct drm_i915_private *dev_priv, 
{

	struct drm_device *dev = dev_priv->dev;



	mutex_lock(&dev_priv->fbc.lock);



	if (!dev_priv->fbc.busy_bits)

		return;

		goto out;



	dev_priv->fbc.busy_bits &= ~frontbuffer_bits;



	if (!dev_priv->fbc.busy_bits)

		intel_fbc_update(dev);

		__intel_fbc_update(dev);



out:

	mutex_unlock(&dev_priv->fbc.lock);

}



/**
@@ -852,6 +921,8 @@ void intel_fbc_init(struct drm_i915_private *dev_priv) 
{

	enum pipe pipe;



	mutex_init(&dev_priv->fbc.lock);



	if (!HAS_FBC(dev_priv)) {

		dev_priv->fbc.enabled = false;

		dev_priv->fbc.no_fbc_reason = FBC_UNSUPPORTED;

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