drm/i915: Implement command buffer parsing logic

The command parser scans batch buffers submitted via execbuffer ioctls before
the driver submits them to hardware. At a high level, it looks for several
things:

1) Commands which are explicitly defined as privileged or which should only be
   used by the kernel driver. The parser generally rejects such commands, with
   the provision that it may allow some from the drm master process.
2) Commands which access registers. To support correct/enhanced userspace
   functionality, particularly certain OpenGL extensions, the parser provides a
   whitelist of registers which userspace may safely access (for both normal and
   drm master processes).
3) Commands which access privileged memory (i.e. GGTT, HWS page, etc). The
   parser always rejects such commands.

See the overview comment in the source for more details.

This patch only implements the logic. Subsequent patches will build the tables
that drive the parser.

v2: Don't set the secure bit if the parser succeeds
Fail harder during init
Makefile cleanup
Kerneldoc cleanup
Clarify module param description
Convert ints to bools in a few places
Move client/subclient defs to i915_reg.h
Remove the bits_count field

OTC-Tracker: AXIA-4631
Change-Id: I50b98c71c6655893291c78a2d1b8954577b37a30
Signed-off-by: Brad Volkin <bradley.d.volkin@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
[danvet: Appease checkpatch.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 12 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index b719385c4511..146609ab42bb 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -175,6 +175,18 @@
 #define VGA_CR_DATA_CGA 0x3d5
 
 /*
+ * Instruction field definitions used by the command parser
+ */
+#define INSTR_CLIENT_SHIFT      29
+#define INSTR_CLIENT_MASK       0xE0000000
+#define   INSTR_MI_CLIENT       0x0
+#define   INSTR_BC_CLIENT       0x2
+#define   INSTR_RC_CLIENT       0x3
+#define INSTR_SUBCLIENT_SHIFT   27
+#define INSTR_SUBCLIENT_MASK    0x18000000
+#define   INSTR_MEDIA_SUBCLIENT 0x2
+
+/*
  * Memory interface instructions used by the kernel
  */
 #define MI_INSTR(opcode, flags) (((opcode) << 23) | (flags))