[Intel-gfx] [PATCH 20/61] drm/i915: Rework clflush to work correctly without obj->mm.lock.

Maarten Lankhorst
2020-10-02T13:00:13Z

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>
---
drivers/gpu/drm/i915/gem/i915_gem_clflush.c | 15 +++++++--------
1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_clflush.c b/drivers/gpu/drm/i915/gem/i915_gem_clflush.c
index bc0223716906..daf9284ef1f5 100644
--- 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 */