drm/i915: Rework clflush to work correctly without obj->mm.lock.

Pin in the caller, not in the work itself. This should also
work better for dma-fence annotations.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210323155059.628690-22-maarten.lankhorst@linux.intel.com

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_clflush.c b/drivers/gpu/drm/i915/gem/i915_gem_clflush.c
index bc02237169064d615c38d3bbe43f0804d75b59bb..daf9284ef1f5408e4536a927e57fa85a79ec28a9 100644 (file)
--- a/drivers/gpu/drm/i915/gem/i915_gem_clflush.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_clflush.c
@@ -27,15 +27,8 @@ static void __do_clflush(struct drm_i915_gem_object *obj)
 static int clflush_work(struct dma_fence_work *base)
 {
        struct clflush *clflush = container_of(base, typeof(*clflush), base);
-       struct drm_i915_gem_object *obj = clflush->obj;
-       int err;
 
-       err = i915_gem_object_pin_pages(obj);
-       if (err)
-               return err;
-
-       __do_clflush(obj);
-       i915_gem_object_unpin_pages(obj);
+       __do_clflush(clflush->obj);
 
        return 0;
 }
@@ -44,6 +37,7 @@ static void clflush_release(struct dma_fence_work *base)
 {
        struct clflush *clflush = container_of(base, typeof(*clflush), base);
 
+       i915_gem_object_unpin_pages(clflush->obj);
        i915_gem_object_put(clflush->obj);
 }
 
@@ -63,6 +57,11 @@ static struct clflush *clflush_work_create(struct drm_i915_gem_object *obj)
        if (!clflush)
                return NULL;
 
+       if (__i915_gem_object_get_pages(obj) < 0) {
+               kfree(clflush);
+               return NULL;
+       }
+
        dma_fence_work_init(&clflush->base, &clflush_ops);
        clflush->obj = i915_gem_object_get(obj); /* obj <-> clflush cycle */