From 611cdf3695a307fdca3ff3779a1e6cca935e2d31 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Fri, 16 Jun 2017 15:05:18 +0100 Subject: drm/i915: Disable EXEC_OBJECT_ASYNC when doing relocations If we write a relocation into the buffer, we require our own implicit synchronisation added after the start of the execbuf, outside of the user's control. As we may end up clflushing, or doing the patch itself on the GPU, asynchronously we need to look at the implicit serialisation on obj->resv and hence need to disable EXEC_OBJECT_ASYNC for this object. If the user does trigger a stall for relocations, we make sure the stall is complete enough so that the batch is not submitted before we complete those relocations. Fixes: 77ae9957897d ("drm/i915: Enable userspace to opt-out of implicit fencing") Signed-off-by: Chris Wilson Cc: Joonas Lahtinen Cc: Jason Ekstrand Reviewed-by: Joonas Lahtinen (cherry picked from commit 071750e550af46b5d3a84ad56c2a108c3e136284) [danvet: Resolve conflicts, resolution reviewed by Tvrtko on irc.] Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_gem_execbuffer.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c index a3e59c8ef27b..9ad13eeed904 100644 --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c @@ -546,11 +546,12 @@ repeat: } static int -i915_gem_execbuffer_relocate_entry(struct drm_i915_gem_object *obj, +i915_gem_execbuffer_relocate_entry(struct i915_vma *vma, struct eb_vmas *eb, struct drm_i915_gem_relocation_entry *reloc, struct reloc_cache *cache) { + struct drm_i915_gem_object *obj = vma->obj; struct drm_i915_private *dev_priv = to_i915(obj->base.dev); struct drm_gem_object *target_obj; struct drm_i915_gem_object *target_i915_obj; @@ -628,6 +629,16 @@ i915_gem_execbuffer_relocate_entry(struct drm_i915_gem_object *obj, return -EINVAL; } + /* + * If we write into the object, we need to force the synchronisation + * barrier, either with an asynchronous clflush or if we executed the + * patching using the GPU (though that should be serialised by the + * timeline). To be completely sure, and since we are required to + * do relocations we are already stalling, disable the user's opt + * of our synchronisation. + */ + vma->exec_entry->flags &= ~EXEC_OBJECT_ASYNC; + ret = relocate_entry(obj, reloc, cache, target_offset); if (ret) return ret; @@ -678,7 +689,7 @@ i915_gem_execbuffer_relocate_vma(struct i915_vma *vma, do { u64 offset = r->presumed_offset; - ret = i915_gem_execbuffer_relocate_entry(vma->obj, eb, r, &cache); + ret = i915_gem_execbuffer_relocate_entry(vma, eb, r, &cache); if (ret) goto out; @@ -726,7 +737,7 @@ i915_gem_execbuffer_relocate_vma_slow(struct i915_vma *vma, reloc_cache_init(&cache, eb->i915); for (i = 0; i < entry->relocation_count; i++) { - ret = i915_gem_execbuffer_relocate_entry(vma->obj, eb, &relocs[i], &cache); + ret = i915_gem_execbuffer_relocate_entry(vma, eb, &relocs[i], &cache); if (ret) break; } -- cgit v1.2.3-59-g8ed1b