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: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_fbc.c b/drivers/gpu/drm/i915/intel_fbc.c
index 55711b4..a076c7a 100644
--- a/drivers/gpu/drm/i915/intel_fbc.c
+++ b/drivers/gpu/drm/i915/intel_fbc.c
@@ -336,6 +336,7 @@
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 @@
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_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 @@
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 @@
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 @@
{
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 @@
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 @@
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 @@
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 @@
*
* 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 @@
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 @@
* 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 @@
/* 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 @@
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 @@
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 @@
{
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 @@
{
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;