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| author | Chris Wilson <chris@chris-wilson.co.uk> | 2019-12-18 10:40:43 +0000 |
|---|---|---|
| committer | Jani Nikula <jani.nikula@intel.com> | 2019-12-23 14:27:23 +0200 |
| commit | e85ade1f50aae464ce196672faa7a099fd1721ed (patch) | |
| tree | 880f24f7d11c68ec4437b80307ae19cef2870ea7 /drivers/gpu/drm/i915/display/intel_frontbuffer.h | |
| parent | d39da686c2f3b8518b6933951d53891aa83227d6 (diff) | |
| download | linux-e85ade1f50aae464ce196672faa7a099fd1721ed.tar.gz linux-e85ade1f50aae464ce196672faa7a099fd1721ed.tar.bz2 linux-e85ade1f50aae464ce196672faa7a099fd1721ed.zip | |
drm/i915: Hold reference to intel_frontbuffer as we track activity
Since obj->frontbuffer is no longer protected by the struct_mutex, as we
are processing the execbuf, it may be removed. Mark the
intel_frontbuffer as rcu protected, and so acquire a reference to
the struct as we track activity upon it.
Closes: https://gitlab.freedesktop.org/drm/intel/issues/827
Fixes: 8e7cb1799b4f ("drm/i915: Extract intel_frontbuffer active tracking")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: <stable@vger.kernel.org> # v5.4+
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191218104043.3539458-1-chris@chris-wilson.co.uk
(cherry picked from commit da42104f589d979bbe402703fd836cec60befae1)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Diffstat (limited to 'drivers/gpu/drm/i915/display/intel_frontbuffer.h')
| -rw-r--r-- | drivers/gpu/drm/i915/display/intel_frontbuffer.h | 34 |
1 files changed, 31 insertions, 3 deletions
diff --git a/drivers/gpu/drm/i915/display/intel_frontbuffer.h b/drivers/gpu/drm/i915/display/intel_frontbuffer.h index adc64d61a4a5..6d41f5394425 100644 --- a/drivers/gpu/drm/i915/display/intel_frontbuffer.h +++ b/drivers/gpu/drm/i915/display/intel_frontbuffer.h @@ -27,10 +27,10 @@ #include <linux/atomic.h> #include <linux/kref.h> +#include "gem/i915_gem_object_types.h" #include "i915_active.h" struct drm_i915_private; -struct drm_i915_gem_object; enum fb_op_origin { ORIGIN_GTT, @@ -45,6 +45,7 @@ struct intel_frontbuffer { atomic_t bits; struct i915_active write; struct drm_i915_gem_object *obj; + struct rcu_head rcu; }; void intel_frontbuffer_flip_prepare(struct drm_i915_private *i915, @@ -54,6 +55,35 @@ void intel_frontbuffer_flip_complete(struct drm_i915_private *i915, void intel_frontbuffer_flip(struct drm_i915_private *i915, unsigned frontbuffer_bits); +void intel_frontbuffer_put(struct intel_frontbuffer *front); + +static inline struct intel_frontbuffer * +__intel_frontbuffer_get(const struct drm_i915_gem_object *obj) +{ + struct intel_frontbuffer *front; + + if (likely(!rcu_access_pointer(obj->frontbuffer))) + return NULL; + + rcu_read_lock(); + do { + front = rcu_dereference(obj->frontbuffer); + if (!front) + break; + + if (unlikely(!kref_get_unless_zero(&front->ref))) + continue; + + if (likely(front == rcu_access_pointer(obj->frontbuffer))) + break; + + intel_frontbuffer_put(front); + } while (1); + rcu_read_unlock(); + + return front; +} + struct intel_frontbuffer * intel_frontbuffer_get(struct drm_i915_gem_object *obj); @@ -119,6 +149,4 @@ void intel_frontbuffer_track(struct intel_frontbuffer *old, struct intel_frontbuffer *new, unsigned int frontbuffer_bits); -void intel_frontbuffer_put(struct intel_frontbuffer *front); - #endif /* __INTEL_FRONTBUFFER_H__ */ |