From: Paulo Zanoni <paulo.r.zanoni@xxxxxxxxx>
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, we can start removing the struct_mutex locking we
have around FBC in the next patches. The only struct_mutex requirement
will be around intel_fbc_update(), since it's the place that does the
CFB stolen memory allocations.
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.
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@xxxxxxxxx>
---
drivers/gpu/drm/i915/i915_debugfs.c | 4 ++
drivers/gpu/drm/i915/i915_drv.h | 1 +
drivers/gpu/drm/i915/i915_gem_stolen.c | 7 +++
drivers/gpu/drm/i915/intel_display.c | 10 +---
drivers/gpu/drm/i915/intel_drv.h | 1 +
drivers/gpu/drm/i915/intel_fbc.c | 86 +++++++++++++++++++++++++++++-----
6 files changed, 89 insertions(+), 20 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 31d8768..5248ed9 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -1619,6 +1619,7 @@ 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");
@@ -1631,6 +1632,7 @@ 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;
@@ -1661,6 +1663,7 @@ 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;
@@ -1669,6 +1672,7 @@ 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;
}
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index ea9caf2..1e17722 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -892,6 +892,7 @@ enum fb_op_origin {
};
struct i915_fbc {
+ struct mutex lock;
unsigned long uncompressed_size;
unsigned threshold;
unsigned int fb_id;
diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c
index 348ed5a..793bcba 100644
--- a/drivers/gpu/drm/i915/i915_gem_stolen.c
+++ b/drivers/gpu/drm/i915/i915_gem_stolen.c
@@ -250,6 +250,8 @@ int i915_gem_stolen_setup_compression(struct drm_device *dev, int size, int fb_c
{
struct drm_i915_private *dev_priv = dev->dev_private;
+ WARN_ON(!mutex_is_locked(&dev_priv->fbc.lock));
+
if (!drm_mm_initialized(&dev_priv->mm.stolen))
return -ENODEV;
@@ -266,6 +268,8 @@ void i915_gem_stolen_cleanup_compression(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = dev->dev_private;
+ WARN_ON(!mutex_is_locked(&dev_priv->fbc.lock));
+
if (dev_priv->fbc.uncompressed_size == 0)
return;
@@ -286,7 +290,10 @@ void i915_gem_cleanup_stolen(struct drm_device *dev)
if (!drm_mm_initialized(&dev_priv->mm.stolen))
return;
+ mutex_lock(&dev_priv->fbc.lock);
i915_gem_stolen_cleanup_compression(dev);
+ mutex_unlock(&dev_priv->fbc.lock);
+
drm_mm_takedown(&dev_priv->mm.stolen);
}
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index eb665d7..eab5aa1 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -4741,7 +4741,6 @@ static void intel_post_plane_update(struct intel_crtc *crtc)
static void intel_pre_plane_update(struct intel_crtc *crtc)
{
struct drm_device *dev = crtc->base.dev;
- struct drm_i915_private *dev_priv = dev->dev_private;
struct intel_crtc_atomic_commit *atomic = &crtc->atomic;
struct drm_plane *p;
@@ -4758,13 +4757,8 @@ 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) {
- mutex_lock(&dev->struct_mutex);
- if (dev_priv->fbc.crtc == crtc)
- intel_fbc_disable(dev);
- mutex_unlock(&dev->struct_mutex);
- }
+ if (atomic->disable_fbc)
+ intel_fbc_disable_crtc(crtc);
if (crtc->atomic.disable_ips)
hsw_disable_ips(crtc);
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 33cff9d..00eea90 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1236,6 +1236,7 @@ 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);
diff --git a/drivers/gpu/drm/i915/intel_fbc.c b/drivers/gpu/drm/i915/intel_fbc.c
index 9e55b9b..543b7a2 100644
--- a/drivers/gpu/drm/i915/intel_fbc.c
+++ b/drivers/gpu/drm/i915/intel_fbc.c
@@ -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)
@@ -516,7 +550,7 @@ static struct drm_crtc *intel_fbc_find_crtc(struct drm_i915_private *dev_priv)
}
/**
- * 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
@@ -534,7 +568,7 @@ static struct drm_crtc *intel_fbc_find_crtc(struct drm_i915_private *dev_priv)
*
* 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;
@@ -544,6 +578,8 @@ void intel_fbc_update(struct drm_device *dev)
const struct drm_display_mode *adjusted_mode;
unsigned int max_width, max_height;
+ WARN_ON(!mutex_is_locked(&dev_priv->fbc.lock));
+
if (!HAS_FBC(dev))
return;
@@ -665,7 +701,7 @@ 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);
@@ -676,11 +712,26 @@ 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);
}
i915_gem_stolen_cleanup_compression(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,
unsigned int frontbuffer_bits,
enum fb_op_origin origin)
@@ -691,6 +742,8 @@ 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)
@@ -702,7 +755,9 @@ 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,
@@ -710,13 +765,18 @@ 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);
}
/**
@@ -729,6 +789,8 @@ 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;
--
2.1.4
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