From 7b5745506603f10acedc2be9f913a7776a3c94fd Mon Sep 17 00:00:00 2001 From: =?utf8?q?Jouni=20H=C3=B6gander?= Date: Thu, 27 Jul 2023 09:41:40 +0300 Subject: [PATCH] drm/i915: Add getter/setter for i915_gem_object->frontbuffer MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Add getter/setter for i915_gem_object->frontbuffer and use it instead of directly touching i915_gem_object->frontbuffer frontbuffer pointer. v3: - Fix intel_frontbuffer_get return value - s/front_ret/cur/ v2: Move getter/setter into i915_gem_object.h Signed-off-by: Jouni Högander Reviewed-by: Nirmoy Das Link: https://patchwork.freedesktop.org/patch/msgid/20230727064142.751976-3-jouni.hogander@intel.com --- drivers/gpu/drm/i915/display/intel_frontbuffer.c | 20 +++---- drivers/gpu/drm/i915/display/intel_frontbuffer.h | 27 ---------- drivers/gpu/drm/i915/gem/i915_gem_object.c | 4 +- drivers/gpu/drm/i915/gem/i915_gem_object.h | 67 ++++++++++++++++++++++++ drivers/gpu/drm/i915/i915_vma.c | 2 +- 5 files changed, 77 insertions(+), 43 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_frontbuffer.c b/drivers/gpu/drm/i915/display/intel_frontbuffer.c index 3ce0436..56f4537 100644 --- a/drivers/gpu/drm/i915/display/intel_frontbuffer.c +++ b/drivers/gpu/drm/i915/display/intel_frontbuffer.c @@ -237,7 +237,7 @@ static void frontbuffer_release(struct kref *ref) } spin_unlock(&obj->vma.lock); - RCU_INIT_POINTER(obj->frontbuffer, NULL); + i915_gem_object_set_frontbuffer(obj, NULL); spin_unlock(&intel_bo_to_i915(obj)->display.fb_tracking.lock); i915_active_fini(&front->write); @@ -250,9 +250,9 @@ struct intel_frontbuffer * intel_frontbuffer_get(struct drm_i915_gem_object *obj) { struct drm_i915_private *i915 = intel_bo_to_i915(obj); - struct intel_frontbuffer *front; + struct intel_frontbuffer *front, *cur; - front = __intel_frontbuffer_get(obj); + front = i915_gem_object_get_frontbuffer(obj); if (front) return front; @@ -269,17 +269,11 @@ intel_frontbuffer_get(struct drm_i915_gem_object *obj) I915_ACTIVE_RETIRE_SLEEPS); spin_lock(&i915->display.fb_tracking.lock); - if (rcu_access_pointer(obj->frontbuffer)) { - kfree(front); - front = rcu_dereference_protected(obj->frontbuffer, true); - kref_get(&front->ref); - } else { - i915_gem_object_get(obj); - rcu_assign_pointer(obj->frontbuffer, front); - } + cur = i915_gem_object_set_frontbuffer(obj, front); spin_unlock(&i915->display.fb_tracking.lock); - - return front; + if (cur != front) + kfree(front); + return cur; } void intel_frontbuffer_put(struct intel_frontbuffer *front) diff --git a/drivers/gpu/drm/i915/display/intel_frontbuffer.h b/drivers/gpu/drm/i915/display/intel_frontbuffer.h index 3c474ed..eeccc84 100644 --- a/drivers/gpu/drm/i915/display/intel_frontbuffer.h +++ b/drivers/gpu/drm/i915/display/intel_frontbuffer.h @@ -75,33 +75,6 @@ void intel_frontbuffer_flip(struct drm_i915_private *i915, 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); diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.c b/drivers/gpu/drm/i915/gem/i915_gem_object.c index 97ac6fb..1484680 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_object.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_object.c @@ -469,7 +469,7 @@ void __i915_gem_object_flush_frontbuffer(struct drm_i915_gem_object *obj, { struct intel_frontbuffer *front; - front = __intel_frontbuffer_get(obj); + front = i915_gem_object_get_frontbuffer(obj); if (front) { intel_frontbuffer_flush(front, origin); intel_frontbuffer_put(front); @@ -481,7 +481,7 @@ void __i915_gem_object_invalidate_frontbuffer(struct drm_i915_gem_object *obj, { struct intel_frontbuffer *front; - front = __intel_frontbuffer_get(obj); + front = i915_gem_object_get_frontbuffer(obj); if (front) { intel_frontbuffer_invalidate(front, origin); intel_frontbuffer_put(front); diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.h b/drivers/gpu/drm/i915/gem/i915_gem_object.h index 884a172..112c130 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_object.h +++ b/drivers/gpu/drm/i915/gem/i915_gem_object.h @@ -891,4 +891,71 @@ static inline int i915_gem_object_userptr_validate(struct drm_i915_gem_object *o #endif +/** + * i915_gem_object_get_frontbuffer - Get the object's frontbuffer + * @obj: The object whose frontbuffer to get. + * + * Get pointer to object's frontbuffer if such exists. Please note that RCU + * mechanism is used to handle e.g. ongoing removal of frontbuffer pointer. + * + * Return: pointer to object's frontbuffer is such exists or NULL + */ +static inline struct intel_frontbuffer * +i915_gem_object_get_frontbuffer(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; +} + +/** + * i915_gem_object_set_frontbuffer - Set the object's frontbuffer + * @obj: The object whose frontbuffer to set. + * @front: The frontbuffer to set + * + * Set object's frontbuffer pointer. If frontbuffer is already set for the + * object keep it and return it's pointer to the caller. Please note that RCU + * mechanism is used to handle e.g. ongoing removal of frontbuffer pointer. This + * function is protected by i915->display.fb_tracking.lock + * + * Return: pointer to frontbuffer which was set. + */ +static inline struct intel_frontbuffer * +i915_gem_object_set_frontbuffer(struct drm_i915_gem_object *obj, + struct intel_frontbuffer *front) +{ + struct intel_frontbuffer *cur = front; + + if (!front) { + RCU_INIT_POINTER(obj->frontbuffer, NULL); + } else if (rcu_access_pointer(obj->frontbuffer)) { + cur = rcu_dereference_protected(obj->frontbuffer, true); + kref_get(&cur->ref); + } else { + drm_gem_object_get(intel_bo_to_drm_bo(obj)); + rcu_assign_pointer(obj->frontbuffer, front); + } + + return cur; +} + #endif diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c index af2e49f..e90b9c8 100644 --- a/drivers/gpu/drm/i915/i915_vma.c +++ b/drivers/gpu/drm/i915/i915_vma.c @@ -1908,7 +1908,7 @@ int _i915_vma_move_to_active(struct i915_vma *vma, if (flags & EXEC_OBJECT_WRITE) { struct intel_frontbuffer *front; - front = __intel_frontbuffer_get(obj); + front = i915_gem_object_get_frontbuffer(obj); if (unlikely(front)) { if (intel_frontbuffer_invalidate(front, ORIGIN_CS)) i915_active_add_request(&front->write, rq); -- 2.7.4