[PATCH 04/54] drm/i915: Check domains for userptr on release

[Chris Wilson]

When we return pages to the system, we release control over them and
should defensively return them to the CPU write domain so that we catch
any external writes on reacquiring them (e.g. to transparently
swapout/swapin). While we did this defensive clflushing for ordinary
shmem pages, it was forgotten for userptr. Fortunately, userptr objects
are normally cache coherent and so oblivious to the forgotten domain
tracking.

References: a679f58d0510 ("drm/i915: Flush pages on acquisition")
References: 754a25442705 ("drm/i915: Skip object locking around a no-op set-domain ioctl")
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Matthew Auld <matthew.william.auld at gmail.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin at linux.intel.com>
---
 drivers/gpu/drm/i915/i915_gem.c         | 3 +--
 drivers/gpu/drm/i915/i915_gem_object.h  | 4 ++++
 drivers/gpu/drm/i915/i915_gem_userptr.c | 4 +---
 3 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index e506e43cfade..c3b4ec52e1b7 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -308,7 +308,7 @@ static void __start_cpu_write(struct drm_i915_gem_object *obj)
 		obj->cache_dirty = true;
 }
 
-static void
+void
 __i915_gem_object_release_shmem(struct drm_i915_gem_object *obj,
 				struct sg_table *pages,
 				bool needs_clflush)
@@ -2202,7 +2202,6 @@ i915_gem_object_put_pages_gtt(struct drm_i915_gem_object *obj,
 	struct page *page;
 
 	__i915_gem_object_release_shmem(obj, pages, true);
-
 	i915_gem_gtt_finish_pages(obj, pages);
 
 	if (i915_gem_object_needs_bit17_swizzle(obj))
diff --git a/drivers/gpu/drm/i915/i915_gem_object.h b/drivers/gpu/drm/i915/i915_gem_object.h
index 1a24dc97e4fd..ca93a40c0c87 100644
--- a/drivers/gpu/drm/i915/i915_gem_object.h
+++ b/drivers/gpu/drm/i915/i915_gem_object.h
@@ -502,4 +502,8 @@ void i915_gem_object_set_cache_coherency(struct drm_i915_gem_object *obj,
 					 unsigned int cache_level);
 void i915_gem_object_flush_if_display(struct drm_i915_gem_object *obj);
 
+void __i915_gem_object_release_shmem(struct drm_i915_gem_object *obj,
+				     struct sg_table *pages,
+				     bool needs_clflush);
+
 #endif
diff --git a/drivers/gpu/drm/i915/i915_gem_userptr.c b/drivers/gpu/drm/i915/i915_gem_userptr.c
index ad0087127144..215bf3fef10c 100644
--- a/drivers/gpu/drm/i915/i915_gem_userptr.c
+++ b/drivers/gpu/drm/i915/i915_gem_userptr.c
@@ -673,9 +673,7 @@ i915_gem_userptr_put_pages(struct drm_i915_gem_object *obj,
 	if (!pages)
 		return;
 
-	if (obj->mm.madv != I915_MADV_WILLNEED)
-		obj->mm.dirty = false;
-
+	__i915_gem_object_release_shmem(obj, pages, true);
 	i915_gem_gtt_finish_pages(obj, pages);
 
 	for_each_sgt_page(page, sgt_iter, pages) {
-- 
2.20.1