drm/i915: Enable register whitelist checks

MI_STORE_REGISTER_MEM, MI_LOAD_REGISTER_MEM, and MI_LOAD_REGISTER_IMM
commands allow userspace access to registers. Only certain registers
should be allowed for such access, so enable checking for those commands.
Each ring gets its own register whitelist.

MI_LOAD_REGISTER_REG on HSW also allows register access but is currently
unused by userspace components. Leave it rejected.

PIPE_CONTROL and MEDIA_VFE_STATE allow register access based on certain
bits being set. Reject those as well.

v2: trailing commas, rebased

OTC-Tracker: AXIA-4631
Change-Id: Ie614a2f0eb2e5917de809e5a17957175d24cc44f
Signed-off-by: Brad Volkin <bradley.d.volkin@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index d90171b..cfaeaf5 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -331,6 +331,7 @@
 #define   DISPLAY_PLANE_B           (1<<20)
 #define GFX_OP_PIPE_CONTROL(len)	((0x3<<29)|(0x3<<27)|(0x2<<24)|(len-2))
 #define   PIPE_CONTROL_GLOBAL_GTT_IVB			(1<<24) /* gen7+ */
+#define   PIPE_CONTROL_MMIO_WRITE			(1<<23)
 #define   PIPE_CONTROL_CS_STALL				(1<<20)
 #define   PIPE_CONTROL_TLB_INVALIDATE			(1<<18)
 #define   PIPE_CONTROL_QW_WRITE				(1<<14)
@@ -371,6 +372,8 @@
 
 #define PIPELINE_SELECT                ((0x3<<29)|(0x1<<27)|(0x1<<24)|(0x4<<16))
 #define GFX_OP_3DSTATE_VF_STATISTICS   ((0x3<<29)|(0x1<<27)|(0x0<<24)|(0xB<<16))
+#define MEDIA_VFE_STATE                ((0x3<<29)|(0x2<<27)|(0x0<<24)|(0x0<<16))
+#define  MEDIA_VFE_STATE_MMIO_ACCESS_MASK (0x18)
 #define GPGPU_OBJECT                   ((0x3<<29)|(0x2<<27)|(0x1<<24)|(0x4<<16))
 #define GPGPU_WALKER                   ((0x3<<29)|(0x2<<27)|(0x1<<24)|(0x5<<16))
 #define GFX_OP_3DSTATE_DX9_CONSTANTF_VS \