drm/i915: Use the async worker to avoid reclaim tainting the ggtt->mutex

On Braswell and Broxton (also known as Valleyview and Apollolake), we
need to serialise updates of the GGTT using the big stop_machine()
hammer. This has the side effect of appearing to lockdep as a possible
reclaim (since it uses the cpuhp mutex and that is tainted by per-cpu
allocations). However, we want to use vm->mutex (including ggtt->mutex)
from within the shrinker and so must avoid such possible taints. For this
purpose, we introduced the asynchronous vma binding and we can apply it
to the PIN_GLOBAL so long as take care to add the necessary waits for
the worker afterwards.

Closes: https://gitlab.freedesktop.org/drm/intel/issues/211
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200130181710.2030251-3-chris@chris-wilson.co.uk

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/gpu/drm/i915/gt/intel_timeline.c b/drivers/gpu/drm/i915/gt/intel_timeline.c
index 87716529cd2f..465f87b65901 100644
--- a/drivers/gpu/drm/i915/gt/intel_timeline.c
+++ b/drivers/gpu/drm/i915/gt/intel_timeline.c
@@ -308,7 +308,7 @@ int intel_timeline_pin(struct intel_timeline *tl)
 	if (atomic_add_unless(&tl->pin_count, 1, 0))
 		return 0;
 
-	err = i915_vma_pin(tl->hwsp_ggtt, 0, 0, PIN_GLOBAL | PIN_HIGH);
+	err = i915_ggtt_pin(tl->hwsp_ggtt, 0, PIN_HIGH);
 	if (err)
 		return err;
 
@@ -431,7 +431,7 @@ __intel_timeline_get_seqno(struct intel_timeline *tl,
 		goto err_rollback;
 	}
 
-	err = i915_vma_pin(vma, 0, 0, PIN_GLOBAL | PIN_HIGH);
+	err = i915_ggtt_pin(vma, 0, PIN_HIGH);
 	if (err) {
 		__idle_hwsp_free(vma->private, cacheline);
 		goto err_rollback;