From 25ad93fd9f0513df41f70327cca19d51369f1674 Mon Sep 17 00:00:00 2001 From: Paulo Zanoni Date: Thu, 2 Jul 2015 19:25:10 -0300 Subject: [PATCH] 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 (v4) Signed-off-by: Paulo Zanoni Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_debugfs.c | 4 ++ drivers/gpu/drm/i915/i915_drv.h | 3 + drivers/gpu/drm/i915/intel_display.c | 6 +- drivers/gpu/drm/i915/intel_drv.h | 1 + drivers/gpu/drm/i915/intel_fbc.c | 101 +++++++++++++++++++++++---- 5 files changed, 96 insertions(+), 19 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c index 6a8de04c6a2b..cc74a92dd346 100644 --- a/drivers/gpu/drm/i915/i915_debugfs.c +++ b/drivers/gpu/drm/i915/i915_debugfs.c @@ -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; } diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index eb10c1624006..093d6421dddf 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -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; diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 136b53371878..93d3bdf242a9 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -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); } diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h index 82abbfae4e23..63d7d32e6123 100644 --- a/drivers/gpu/drm/i915/intel_drv.h +++ b/drivers/gpu/drm/i915/intel_drv.h @@ -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); diff --git a/drivers/gpu/drm/i915/intel_fbc.c b/drivers/gpu/drm/i915/intel_fbc.c index 55711b452fbf..a076c7a25062 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) @@ -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; -- 2.20.1