[Intel-gfx] [PATCH 08/13] drm/i915: Enable register whitelist checks

[bradley.d.volkin at intel.com]

From: Brad Volkin <bradley.d.volkin at intel.com>

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 at intel.com>
---
 drivers/gpu/drm/i915/i915_cmd_parser.c | 21 ++++++++++++++++++---
 drivers/gpu/drm/i915/i915_reg.h        |  3 +++
 2 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_cmd_parser.c b/drivers/gpu/drm/i915/i915_cmd_parser.c
index 353e5cf..4f14a24 100644
--- a/drivers/gpu/drm/i915/i915_cmd_parser.c
+++ b/drivers/gpu/drm/i915/i915_cmd_parser.c
@@ -122,9 +122,12 @@ static const struct drm_i915_cmd_descriptor common_cmds[] = {
 	CMD(  MI_SUSPEND_FLUSH,                 SMI,    F,  1,      S  ),
 	CMD(  MI_SEMAPHORE_MBOX,                SMI,   !F,  0xFF,   R  ),
 	CMD(  MI_STORE_DWORD_INDEX,             SMI,   !F,  0xFF,   R  ),
-	CMD(  MI_LOAD_REGISTER_IMM(1),          SMI,   !F,  0xFF,   R  ),
-	CMD(  MI_STORE_REGISTER_MEM(1),         SMI,   !F,  0xFF,   R  ),
-	CMD(  MI_LOAD_REGISTER_MEM,             SMI,   !F,  0xFF,   R  ),
+	CMD(  MI_LOAD_REGISTER_IMM(1),          SMI,   !F,  0xFF,   W,
+	      .reg = { .offset = 1, .mask = 0x007FFFFC }               ),
+	CMD(  MI_STORE_REGISTER_MEM(1),         SMI,   !F,  0xFF,   W,
+	      .reg = { .offset = 1, .mask = 0x007FFFFC }               ),
+	CMD(  MI_LOAD_REGISTER_MEM,             SMI,   !F,  0xFF,   W,
+	      .reg = { .offset = 1, .mask = 0x007FFFFC }               ),
 	CMD(  MI_BATCH_BUFFER_START,            SMI,   !F,  0xFF,   S  ),
 };
 
@@ -141,9 +144,21 @@ static const struct drm_i915_cmd_descriptor render_cmds[] = {
 	CMD(  MI_CONDITIONAL_BATCH_BUFFER_END,  SMI,   !F,  0xFF,   S  ),
 	CMD(  GFX_OP_3DSTATE_VF_STATISTICS,     S3D,    F,  1,      S  ),
 	CMD(  PIPELINE_SELECT,                  S3D,    F,  1,      S  ),
+	CMD(  MEDIA_VFE_STATE,			S3D,   !F,  0xFFFF, B,
+	      .bits = {{
+			.offset = 2,
+			.mask = MEDIA_VFE_STATE_MMIO_ACCESS_MASK,
+			.expected = 0,
+	      }},						       ),
 	CMD(  GPGPU_OBJECT,                     S3D,   !F,  0xFF,   S  ),
 	CMD(  GPGPU_WALKER,                     S3D,   !F,  0xFF,   S  ),
 	CMD(  GFX_OP_3DSTATE_SO_DECL_LIST,      S3D,   !F,  0x1FF,  S  ),
+	CMD(  GFX_OP_PIPE_CONTROL(5),           S3D,   !F,  0xFF,   B,
+	      .bits = {{
+			.offset = 1,
+			.mask = PIPE_CONTROL_MMIO_WRITE,
+			.expected = 0,
+	      }},						       ),
 };
 
 static const struct drm_i915_cmd_descriptor hsw_render_cmds[] = {
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 87523df..11cca96 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -330,6 +330,7 @@
 #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)
@@ -370,6 +371,8 @@
 
 #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 \
-- 
1.8.3.2