[Intel-gfx] [PATCH] drm/i915: Add an optional selection from i915 of CONFIG_MMU_NOTIFIER

[Chris Wilson]

userptr requires mmu-notifier for full unprivileged support. Most
systems have mmu-notifier support already enabled as a requirement for
virtualisation support, but we should make the option for i915 to take
advantage of mmu-notifiers explicit (and enable by default so that
regular userspace can take advantage of passing client memory to the
GPU.)

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/Kconfig | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/gpu/drm/i915/Kconfig b/drivers/gpu/drm/i915/Kconfig
index eb87e2538861..1e33195e4a12 100644
--- a/drivers/gpu/drm/i915/Kconfig
+++ b/drivers/gpu/drm/i915/Kconfig
@@ -62,3 +62,14 @@ config DRM_I915_PRELIMINARY_HW_SUPPORT
 	  option changes the default for that module option.
 
 	  If in doubt, say "N".
+
+config DRM_I915_USERPTR
+	bool "Always enable userptr support"
+	depends on DRM_I915
+	select MMU_NOTIFIER
+	default y
+	help
+	  This option selects CONFIG_MMU_NOTIFIER if it isn't already
+	  selected to enabled full userptr support.
+
+	  If in doubt, say "Y".
-- 
2.1.4