diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 0b236ea0996c..719a933c5756 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -1133,6 +1133,52 @@ i915_gem_object_wait_rendering(struct drm_i915_gem_object *obj, return 0; } +/* A nonblocking variant of the above wait. This is a highly dangerous routine + * as the object state may change during this call. + */ +static __must_check int +i915_gem_object_wait_rendering__nonblocking(struct drm_i915_gem_object *obj, + bool readonly) +{ + struct drm_device *dev = obj->base.dev; + struct drm_i915_private *dev_priv = dev->dev_private; + struct intel_ring_buffer *ring = obj->ring; + u32 seqno; + int ret; + + BUG_ON(!mutex_is_locked(&dev->struct_mutex)); + BUG_ON(!dev_priv->mm.interruptible); + + seqno = readonly ? obj->last_write_seqno : obj->last_read_seqno; + if (seqno == 0) + return 0; + + ret = i915_gem_check_wedge(dev_priv, true); + if (ret) + return ret; + + ret = i915_gem_check_olr(ring, seqno); + if (ret) + return ret; + + mutex_unlock(&dev->struct_mutex); + ret = __wait_seqno(ring, seqno, true, NULL); + mutex_lock(&dev->struct_mutex); + + i915_gem_retire_requests_ring(ring); + + /* Manually manage the write flush as we may have not yet + * retired the buffer. + */ + if (obj->last_write_seqno && + i915_seqno_passed(seqno, obj->last_write_seqno)) { + obj->last_write_seqno = 0; + obj->base.write_domain &= ~I915_GEM_GPU_DOMAINS; + } + + return ret; +} + /** * Called when user space prepares to use an object with the CPU, either * through the mmap ioctl's mapping or a GTT mapping. @@ -1170,6 +1216,14 @@ i915_gem_set_domain_ioctl(struct drm_device *dev, void *data, goto unlock; } + /* Try to flush the object off the GPU without holding the lock. + * We will repeat the flush holding the lock in the normal manner + * to catch cases where we are gazumped. + */ + ret = i915_gem_object_wait_rendering__nonblocking(obj, !write_domain); + if (ret) + goto unref; + if (read_domains & I915_GEM_DOMAIN_GTT) { ret = i915_gem_object_set_to_gtt_domain(obj, write_domain != 0); @@ -1183,6 +1237,7 @@ i915_gem_set_domain_ioctl(struct drm_device *dev, void *data, ret = i915_gem_object_set_to_cpu_domain(obj, write_domain != 0); } +unref: drm_gem_object_unreference(&obj->base); unlock: mutex_unlock(&dev->struct_mutex);