Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1568 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_cmd_parser.c b/drivers/gpu/drm/i915/i915_cmd_parser.c
new file mode 100644
index 000000000..f6b81f325
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_cmd_parser.c
@@ -0,0 +1,1568 @@
+/*
+ * Copyright © 2013 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ * Authors:
+ *    Brad Volkin <bradley.d.volkin@intel.com>
+ *
+ */
+
+#include "i915_drv.h"
+#include "intel_ringbuffer.h"
+
+/**
+ * DOC: batch buffer command parser
+ *
+ * Motivation:
+ * Certain OpenGL features (e.g. transform feedback, performance monitoring)
+ * require userspace code to submit batches containing commands such as
+ * MI_LOAD_REGISTER_IMM to access various registers. Unfortunately, some
+ * generations of the hardware will noop these commands in "unsecure" batches
+ * (which includes all userspace batches submitted via i915) even though the
+ * commands may be safe and represent the intended programming model of the
+ * device.
+ *
+ * The software command parser is similar in operation to the command parsing
+ * done in hardware for unsecure batches. However, the software parser allows
+ * some operations that would be noop'd by hardware, if the parser determines
+ * the operation is safe, and submits the batch as "secure" to prevent hardware
+ * parsing.
+ *
+ * Threats:
+ * At a high level, the hardware (and software) checks attempt to prevent
+ * granting userspace undue privileges. There are three categories of privilege.
+ *
+ * First, commands which are explicitly defined as privileged or which should
+ * only be used by the kernel driver. The parser rejects such commands
+ *
+ * Second, 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
+ *
+ * Third, commands which access privileged memory (i.e. GGTT, HWS page, etc).
+ * The parser always rejects such commands.
+ *
+ * The majority of the problematic commands fall in the MI_* range, with only a
+ * few specific commands on each engine (e.g. PIPE_CONTROL and MI_FLUSH_DW).
+ *
+ * Implementation:
+ * Each engine maintains tables of commands and registers which the parser
+ * uses in scanning batch buffers submitted to that engine.
+ *
+ * Since the set of commands that the parser must check for is significantly
+ * smaller than the number of commands supported, the parser tables contain only
+ * those commands required by the parser. This generally works because command
+ * opcode ranges have standard command length encodings. So for commands that
+ * the parser does not need to check, it can easily skip them. This is
+ * implemented via a per-engine length decoding vfunc.
+ *
+ * Unfortunately, there are a number of commands that do not follow the standard
+ * length encoding for their opcode range, primarily amongst the MI_* commands.
+ * To handle this, the parser provides a way to define explicit "skip" entries
+ * in the per-engine command tables.
+ *
+ * Other command table entries map fairly directly to high level categories
+ * mentioned above: rejected, register whitelist. The parser implements a number
+ * of checks, including the privileged memory checks, via a general bitmasking
+ * mechanism.
+ */
+
+/*
+ * A command that requires special handling by the command parser.
+ */
+struct drm_i915_cmd_descriptor {
+	/*
+	 * Flags describing how the command parser processes the command.
+	 *
+	 * CMD_DESC_FIXED: The command has a fixed length if this is set,
+	 *                 a length mask if not set
+	 * CMD_DESC_SKIP: The command is allowed but does not follow the
+	 *                standard length encoding for the opcode range in
+	 *                which it falls
+	 * CMD_DESC_REJECT: The command is never allowed
+	 * CMD_DESC_REGISTER: The command should be checked against the
+	 *                    register whitelist for the appropriate ring
+	 */
+	u32 flags;
+#define CMD_DESC_FIXED    (1<<0)
+#define CMD_DESC_SKIP     (1<<1)
+#define CMD_DESC_REJECT   (1<<2)
+#define CMD_DESC_REGISTER (1<<3)
+#define CMD_DESC_BITMASK  (1<<4)
+
+	/*
+	 * The command's unique identification bits and the bitmask to get them.
+	 * This isn't strictly the opcode field as defined in the spec and may
+	 * also include type, subtype, and/or subop fields.
+	 */
+	struct {
+		u32 value;
+		u32 mask;
+	} cmd;
+
+	/*
+	 * The command's length. The command is either fixed length (i.e. does
+	 * not include a length field) or has a length field mask. The flag
+	 * CMD_DESC_FIXED indicates a fixed length. Otherwise, the command has
+	 * a length mask. All command entries in a command table must include
+	 * length information.
+	 */
+	union {
+		u32 fixed;
+		u32 mask;
+	} length;
+
+	/*
+	 * Describes where to find a register address in the command to check
+	 * against the ring's register whitelist. Only valid if flags has the
+	 * CMD_DESC_REGISTER bit set.
+	 *
+	 * A non-zero step value implies that the command may access multiple
+	 * registers in sequence (e.g. LRI), in that case step gives the
+	 * distance in dwords between individual offset fields.
+	 */
+	struct {
+		u32 offset;
+		u32 mask;
+		u32 step;
+	} reg;
+
+#define MAX_CMD_DESC_BITMASKS 3
+	/*
+	 * Describes command checks where a particular dword is masked and
+	 * compared against an expected value. If the command does not match
+	 * the expected value, the parser rejects it. Only valid if flags has
+	 * the CMD_DESC_BITMASK bit set. Only entries where mask is non-zero
+	 * are valid.
+	 *
+	 * If the check specifies a non-zero condition_mask then the parser
+	 * only performs the check when the bits specified by condition_mask
+	 * are non-zero.
+	 */
+	struct {
+		u32 offset;
+		u32 mask;
+		u32 expected;
+		u32 condition_offset;
+		u32 condition_mask;
+	} bits[MAX_CMD_DESC_BITMASKS];
+};
+
+/*
+ * A table of commands requiring special handling by the command parser.
+ *
+ * Each engine has an array of tables. Each table consists of an array of
+ * command descriptors, which must be sorted with command opcodes in
+ * ascending order.
+ */
+struct drm_i915_cmd_table {
+	const struct drm_i915_cmd_descriptor *table;
+	int count;
+};
+
+#define STD_MI_OPCODE_SHIFT  (32 - 9)
+#define STD_3D_OPCODE_SHIFT  (32 - 16)
+#define STD_2D_OPCODE_SHIFT  (32 - 10)
+#define STD_MFX_OPCODE_SHIFT (32 - 16)
+#define MIN_OPCODE_SHIFT 16
+
+#define CMD(op, opm, f, lm, fl, ...)				\
+	{							\
+		.flags = (fl) | ((f) ? CMD_DESC_FIXED : 0),	\
+		.cmd = { (op & ~0u << (opm)), ~0u << (opm) },	\
+		.length = { (lm) },				\
+		__VA_ARGS__					\
+	}
+
+/* Convenience macros to compress the tables */
+#define SMI STD_MI_OPCODE_SHIFT
+#define S3D STD_3D_OPCODE_SHIFT
+#define S2D STD_2D_OPCODE_SHIFT
+#define SMFX STD_MFX_OPCODE_SHIFT
+#define F true
+#define S CMD_DESC_SKIP
+#define R CMD_DESC_REJECT
+#define W CMD_DESC_REGISTER
+#define B CMD_DESC_BITMASK
+
+/*            Command                          Mask   Fixed Len   Action
+	      ---------------------------------------------------------- */
+static const struct drm_i915_cmd_descriptor gen7_common_cmds[] = {
+	CMD(  MI_NOOP,                          SMI,    F,  1,      S  ),
+	CMD(  MI_USER_INTERRUPT,                SMI,    F,  1,      R  ),
+	CMD(  MI_WAIT_FOR_EVENT,                SMI,    F,  1,      R  ),
+	CMD(  MI_ARB_CHECK,                     SMI,    F,  1,      S  ),
+	CMD(  MI_REPORT_HEAD,                   SMI,    F,  1,      S  ),
+	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,   W,
+	      .reg = { .offset = 1, .mask = 0x007FFFFC, .step = 2 }    ),
+	CMD(  MI_STORE_REGISTER_MEM,            SMI,    F,  3,     W | B,
+	      .reg = { .offset = 1, .mask = 0x007FFFFC },
+	      .bits = {{
+			.offset = 0,
+			.mask = MI_GLOBAL_GTT,
+			.expected = 0,
+	      }},						       ),
+	CMD(  MI_LOAD_REGISTER_MEM,             SMI,    F,  3,     W | B,
+	      .reg = { .offset = 1, .mask = 0x007FFFFC },
+	      .bits = {{
+			.offset = 0,
+			.mask = MI_GLOBAL_GTT,
+			.expected = 0,
+	      }},						       ),
+	/*
+	 * MI_BATCH_BUFFER_START requires some special handling. It's not
+	 * really a 'skip' action but it doesn't seem like it's worth adding
+	 * a new action. See i915_parse_cmds().
+	 */
+	CMD(  MI_BATCH_BUFFER_START,            SMI,   !F,  0xFF,   S  ),
+};
+
+static const struct drm_i915_cmd_descriptor gen7_render_cmds[] = {
+	CMD(  MI_FLUSH,                         SMI,    F,  1,      S  ),
+	CMD(  MI_ARB_ON_OFF,                    SMI,    F,  1,      R  ),
+	CMD(  MI_PREDICATE,                     SMI,    F,  1,      S  ),
+	CMD(  MI_TOPOLOGY_FILTER,               SMI,    F,  1,      S  ),
+	CMD(  MI_SET_APPID,                     SMI,    F,  1,      S  ),
+	CMD(  MI_DISPLAY_FLIP,                  SMI,   !F,  0xFF,   R  ),
+	CMD(  MI_SET_CONTEXT,                   SMI,   !F,  0xFF,   R  ),
+	CMD(  MI_URB_CLEAR,                     SMI,   !F,  0xFF,   S  ),
+	CMD(  MI_STORE_DWORD_IMM,               SMI,   !F,  0x3F,   B,
+	      .bits = {{
+			.offset = 0,
+			.mask = MI_GLOBAL_GTT,
+			.expected = 0,
+	      }},						       ),
+	CMD(  MI_UPDATE_GTT,                    SMI,   !F,  0xFF,   R  ),
+	CMD(  MI_CLFLUSH,                       SMI,   !F,  0x3FF,  B,
+	      .bits = {{
+			.offset = 0,
+			.mask = MI_GLOBAL_GTT,
+			.expected = 0,
+	      }},						       ),
+	CMD(  MI_REPORT_PERF_COUNT,             SMI,   !F,  0x3F,   B,
+	      .bits = {{
+			.offset = 1,
+			.mask = MI_REPORT_PERF_COUNT_GGTT,
+			.expected = 0,
+	      }},						       ),
+	CMD(  MI_CONDITIONAL_BATCH_BUFFER_END,  SMI,   !F,  0xFF,   B,
+	      .bits = {{
+			.offset = 0,
+			.mask = MI_GLOBAL_GTT,
+			.expected = 0,
+	      }},						       ),
+	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 | PIPE_CONTROL_NOTIFY),
+			.expected = 0,
+	      },
+	      {
+			.offset = 1,
+		        .mask = (PIPE_CONTROL_GLOBAL_GTT_IVB |
+				 PIPE_CONTROL_STORE_DATA_INDEX),
+			.expected = 0,
+			.condition_offset = 1,
+			.condition_mask = PIPE_CONTROL_POST_SYNC_OP_MASK,
+	      }},						       ),
+};
+
+static const struct drm_i915_cmd_descriptor hsw_render_cmds[] = {
+	CMD(  MI_SET_PREDICATE,                 SMI,    F,  1,      S  ),
+	CMD(  MI_RS_CONTROL,                    SMI,    F,  1,      S  ),
+	CMD(  MI_URB_ATOMIC_ALLOC,              SMI,    F,  1,      S  ),
+	CMD(  MI_SET_APPID,                     SMI,    F,  1,      S  ),
+	CMD(  MI_RS_CONTEXT,                    SMI,    F,  1,      S  ),
+	CMD(  MI_LOAD_SCAN_LINES_INCL,          SMI,   !F,  0x3F,   R  ),
+	CMD(  MI_LOAD_SCAN_LINES_EXCL,          SMI,   !F,  0x3F,   R  ),
+	CMD(  MI_LOAD_REGISTER_REG,             SMI,   !F,  0xFF,   W,
+	      .reg = { .offset = 1, .mask = 0x007FFFFC, .step = 1 }    ),
+	CMD(  MI_RS_STORE_DATA_IMM,             SMI,   !F,  0xFF,   S  ),
+	CMD(  MI_LOAD_URB_MEM,                  SMI,   !F,  0xFF,   S  ),
+	CMD(  MI_STORE_URB_MEM,                 SMI,   !F,  0xFF,   S  ),
+	CMD(  GFX_OP_3DSTATE_DX9_CONSTANTF_VS,  S3D,   !F,  0x7FF,  S  ),
+	CMD(  GFX_OP_3DSTATE_DX9_CONSTANTF_PS,  S3D,   !F,  0x7FF,  S  ),
+
+	CMD(  GFX_OP_3DSTATE_BINDING_TABLE_EDIT_VS,  S3D,   !F,  0x1FF,  S  ),
+	CMD(  GFX_OP_3DSTATE_BINDING_TABLE_EDIT_GS,  S3D,   !F,  0x1FF,  S  ),
+	CMD(  GFX_OP_3DSTATE_BINDING_TABLE_EDIT_HS,  S3D,   !F,  0x1FF,  S  ),
+	CMD(  GFX_OP_3DSTATE_BINDING_TABLE_EDIT_DS,  S3D,   !F,  0x1FF,  S  ),
+	CMD(  GFX_OP_3DSTATE_BINDING_TABLE_EDIT_PS,  S3D,   !F,  0x1FF,  S  ),
+};
+
+static const struct drm_i915_cmd_descriptor gen7_video_cmds[] = {
+	CMD(  MI_ARB_ON_OFF,                    SMI,    F,  1,      R  ),
+	CMD(  MI_SET_APPID,                     SMI,    F,  1,      S  ),
+	CMD(  MI_STORE_DWORD_IMM,               SMI,   !F,  0xFF,   B,
+	      .bits = {{
+			.offset = 0,
+			.mask = MI_GLOBAL_GTT,
+			.expected = 0,
+	      }},						       ),
+	CMD(  MI_UPDATE_GTT,                    SMI,   !F,  0x3F,   R  ),
+	CMD(  MI_FLUSH_DW,                      SMI,   !F,  0x3F,   B,
+	      .bits = {{
+			.offset = 0,
+			.mask = MI_FLUSH_DW_NOTIFY,
+			.expected = 0,
+	      },
+	      {
+			.offset = 1,
+			.mask = MI_FLUSH_DW_USE_GTT,
+			.expected = 0,
+			.condition_offset = 0,
+			.condition_mask = MI_FLUSH_DW_OP_MASK,
+	      },
+	      {
+			.offset = 0,
+			.mask = MI_FLUSH_DW_STORE_INDEX,
+			.expected = 0,
+			.condition_offset = 0,
+			.condition_mask = MI_FLUSH_DW_OP_MASK,
+	      }},						       ),
+	CMD(  MI_CONDITIONAL_BATCH_BUFFER_END,  SMI,   !F,  0xFF,   B,
+	      .bits = {{
+			.offset = 0,
+			.mask = MI_GLOBAL_GTT,
+			.expected = 0,
+	      }},						       ),
+	/*
+	 * MFX_WAIT doesn't fit the way we handle length for most commands.
+	 * It has a length field but it uses a non-standard length bias.
+	 * It is always 1 dword though, so just treat it as fixed length.
+	 */
+	CMD(  MFX_WAIT,                         SMFX,   F,  1,      S  ),
+};
+
+static const struct drm_i915_cmd_descriptor gen7_vecs_cmds[] = {
+	CMD(  MI_ARB_ON_OFF,                    SMI,    F,  1,      R  ),
+	CMD(  MI_SET_APPID,                     SMI,    F,  1,      S  ),
+	CMD(  MI_STORE_DWORD_IMM,               SMI,   !F,  0xFF,   B,
+	      .bits = {{
+			.offset = 0,
+			.mask = MI_GLOBAL_GTT,
+			.expected = 0,
+	      }},						       ),
+	CMD(  MI_UPDATE_GTT,                    SMI,   !F,  0x3F,   R  ),
+	CMD(  MI_FLUSH_DW,                      SMI,   !F,  0x3F,   B,
+	      .bits = {{
+			.offset = 0,
+			.mask = MI_FLUSH_DW_NOTIFY,
+			.expected = 0,
+	      },
+	      {
+			.offset = 1,
+			.mask = MI_FLUSH_DW_USE_GTT,
+			.expected = 0,
+			.condition_offset = 0,
+			.condition_mask = MI_FLUSH_DW_OP_MASK,
+	      },
+	      {
+			.offset = 0,
+			.mask = MI_FLUSH_DW_STORE_INDEX,
+			.expected = 0,
+			.condition_offset = 0,
+			.condition_mask = MI_FLUSH_DW_OP_MASK,
+	      }},						       ),
+	CMD(  MI_CONDITIONAL_BATCH_BUFFER_END,  SMI,   !F,  0xFF,   B,
+	      .bits = {{
+			.offset = 0,
+			.mask = MI_GLOBAL_GTT,
+			.expected = 0,
+	      }},						       ),
+};
+
+static const struct drm_i915_cmd_descriptor gen7_blt_cmds[] = {
+	CMD(  MI_DISPLAY_FLIP,                  SMI,   !F,  0xFF,   R  ),
+	CMD(  MI_STORE_DWORD_IMM,               SMI,   !F,  0x3FF,  B,
+	      .bits = {{
+			.offset = 0,
+			.mask = MI_GLOBAL_GTT,
+			.expected = 0,
+	      }},						       ),
+	CMD(  MI_UPDATE_GTT,                    SMI,   !F,  0x3F,   R  ),
+	CMD(  MI_FLUSH_DW,                      SMI,   !F,  0x3F,   B,
+	      .bits = {{
+			.offset = 0,
+			.mask = MI_FLUSH_DW_NOTIFY,
+			.expected = 0,
+	      },
+	      {
+			.offset = 1,
+			.mask = MI_FLUSH_DW_USE_GTT,
+			.expected = 0,
+			.condition_offset = 0,
+			.condition_mask = MI_FLUSH_DW_OP_MASK,
+	      },
+	      {
+			.offset = 0,
+			.mask = MI_FLUSH_DW_STORE_INDEX,
+			.expected = 0,
+			.condition_offset = 0,
+			.condition_mask = MI_FLUSH_DW_OP_MASK,
+	      }},						       ),
+	CMD(  COLOR_BLT,                        S2D,   !F,  0x3F,   S  ),
+	CMD(  SRC_COPY_BLT,                     S2D,   !F,  0x3F,   S  ),
+};
+
+static const struct drm_i915_cmd_descriptor hsw_blt_cmds[] = {
+	CMD(  MI_LOAD_SCAN_LINES_INCL,          SMI,   !F,  0x3F,   R  ),
+	CMD(  MI_LOAD_SCAN_LINES_EXCL,          SMI,   !F,  0x3F,   R  ),
+};
+
+/*
+ * For Gen9 we can still rely on the h/w to enforce cmd security, and only
+ * need to re-enforce the register access checks. We therefore only need to
+ * teach the cmdparser how to find the end of each command, and identify
+ * register accesses. The table doesn't need to reject any commands, and so
+ * the only commands listed here are:
+ *   1) Those that touch registers
+ *   2) Those that do not have the default 8-bit length
+ *
+ * Note that the default MI length mask chosen for this table is 0xFF, not
+ * the 0x3F used on older devices. This is because the vast majority of MI
+ * cmds on Gen9 use a standard 8-bit Length field.
+ * All the Gen9 blitter instructions are standard 0xFF length mask, and
+ * none allow access to non-general registers, so in fact no BLT cmds are
+ * included in the table at all.
+ *
+ */
+static const struct drm_i915_cmd_descriptor gen9_blt_cmds[] = {
+	CMD(  MI_NOOP,                          SMI,    F,  1,      S  ),
+	CMD(  MI_USER_INTERRUPT,                SMI,    F,  1,      S  ),
+	CMD(  MI_WAIT_FOR_EVENT,                SMI,    F,  1,      S  ),
+	CMD(  MI_FLUSH,                         SMI,    F,  1,      S  ),
+	CMD(  MI_ARB_CHECK,                     SMI,    F,  1,      S  ),
+	CMD(  MI_REPORT_HEAD,                   SMI,    F,  1,      S  ),
+	CMD(  MI_ARB_ON_OFF,                    SMI,    F,  1,      S  ),
+	CMD(  MI_SUSPEND_FLUSH,                 SMI,    F,  1,      S  ),
+	CMD(  MI_LOAD_SCAN_LINES_INCL,          SMI,   !F,  0x3F,   S  ),
+	CMD(  MI_LOAD_SCAN_LINES_EXCL,          SMI,   !F,  0x3F,   S  ),
+	CMD(  MI_STORE_DWORD_IMM,               SMI,   !F,  0x3FF,  S  ),
+	CMD(  MI_LOAD_REGISTER_IMM(1),          SMI,   !F,  0xFF,   W,
+	      .reg = { .offset = 1, .mask = 0x007FFFFC, .step = 2 }    ),
+	CMD(  MI_UPDATE_GTT,                    SMI,   !F,  0x3FF,  S  ),
+	CMD(  MI_STORE_REGISTER_MEM_GEN8,       SMI,    F,  4,      W,
+	      .reg = { .offset = 1, .mask = 0x007FFFFC }               ),
+	CMD(  MI_FLUSH_DW,                      SMI,   !F,  0x3F,   S  ),
+	CMD(  MI_LOAD_REGISTER_MEM_GEN8,        SMI,    F,  4,      W,
+	      .reg = { .offset = 1, .mask = 0x007FFFFC }               ),
+	CMD(  MI_LOAD_REGISTER_REG,             SMI,    !F,  0xFF,  W,
+	      .reg = { .offset = 1, .mask = 0x007FFFFC, .step = 1 }    ),
+
+	/*
+	 * We allow BB_START but apply further checks. We just sanitize the
+	 * basic fields here.
+	 */
+#define MI_BB_START_OPERAND_MASK   GENMASK(SMI-1, 0)
+#define MI_BB_START_OPERAND_EXPECT (MI_BATCH_PPGTT_HSW | 1)
+	CMD(  MI_BATCH_BUFFER_START_GEN8,       SMI,    !F,  0xFF,  B,
+	      .bits = {{
+			.offset = 0,
+			.mask = MI_BB_START_OPERAND_MASK,
+			.expected = MI_BB_START_OPERAND_EXPECT,
+	      }},						       ),
+};
+
+static const struct drm_i915_cmd_descriptor noop_desc =
+	CMD(MI_NOOP, SMI, F, 1, S);
+
+#undef CMD
+#undef SMI
+#undef S3D
+#undef S2D
+#undef SMFX
+#undef F
+#undef S
+#undef R
+#undef W
+#undef B
+
+static const struct drm_i915_cmd_table gen7_render_cmd_table[] = {
+	{ gen7_common_cmds, ARRAY_SIZE(gen7_common_cmds) },
+	{ gen7_render_cmds, ARRAY_SIZE(gen7_render_cmds) },
+};
+
+static const struct drm_i915_cmd_table hsw_render_ring_cmd_table[] = {
+	{ gen7_common_cmds, ARRAY_SIZE(gen7_common_cmds) },
+	{ gen7_render_cmds, ARRAY_SIZE(gen7_render_cmds) },
+	{ hsw_render_cmds, ARRAY_SIZE(hsw_render_cmds) },
+};
+
+static const struct drm_i915_cmd_table gen7_video_cmd_table[] = {
+	{ gen7_common_cmds, ARRAY_SIZE(gen7_common_cmds) },
+	{ gen7_video_cmds, ARRAY_SIZE(gen7_video_cmds) },
+};
+
+static const struct drm_i915_cmd_table hsw_vebox_cmd_table[] = {
+	{ gen7_common_cmds, ARRAY_SIZE(gen7_common_cmds) },
+	{ gen7_vecs_cmds, ARRAY_SIZE(gen7_vecs_cmds) },
+};
+
+static const struct drm_i915_cmd_table gen7_blt_cmd_table[] = {
+	{ gen7_common_cmds, ARRAY_SIZE(gen7_common_cmds) },
+	{ gen7_blt_cmds, ARRAY_SIZE(gen7_blt_cmds) },
+};
+
+static const struct drm_i915_cmd_table hsw_blt_ring_cmd_table[] = {
+	{ gen7_common_cmds, ARRAY_SIZE(gen7_common_cmds) },
+	{ gen7_blt_cmds, ARRAY_SIZE(gen7_blt_cmds) },
+	{ hsw_blt_cmds, ARRAY_SIZE(hsw_blt_cmds) },
+};
+
+static const struct drm_i915_cmd_table gen9_blt_cmd_table[] = {
+	{ gen9_blt_cmds, ARRAY_SIZE(gen9_blt_cmds) },
+};
+
+
+/*
+ * Register whitelists, sorted by increasing register offset.
+ */
+
+/*
+ * An individual whitelist entry granting access to register addr.  If
+ * mask is non-zero the argument of immediate register writes will be
+ * AND-ed with mask, and the command will be rejected if the result
+ * doesn't match value.
+ *
+ * Registers with non-zero mask are only allowed to be written using
+ * LRI.
+ */
+struct drm_i915_reg_descriptor {
+	i915_reg_t addr;
+	u32 mask;
+	u32 value;
+};
+
+/* Convenience macro for adding 32-bit registers. */
+#define REG32(_reg, ...) \
+	{ .addr = (_reg), __VA_ARGS__ }
+
+#define REG32_IDX(_reg, idx) \
+	{ .addr = _reg(idx) }
+
+/*
+ * Convenience macro for adding 64-bit registers.
+ *
+ * Some registers that userspace accesses are 64 bits. The register
+ * access commands only allow 32-bit accesses. Hence, we have to include
+ * entries for both halves of the 64-bit registers.
+ */
+#define REG64(_reg) \
+	{ .addr = _reg }, \
+	{ .addr = _reg ## _UDW }
+
+#define REG64_IDX(_reg, idx) \
+	{ .addr = _reg(idx) }, \
+	{ .addr = _reg ## _UDW(idx) }
+
+static const struct drm_i915_reg_descriptor gen7_render_regs[] = {
+	REG64(GPGPU_THREADS_DISPATCHED),
+	REG64(HS_INVOCATION_COUNT),
+	REG64(DS_INVOCATION_COUNT),
+	REG64(IA_VERTICES_COUNT),
+	REG64(IA_PRIMITIVES_COUNT),
+	REG64(VS_INVOCATION_COUNT),
+	REG64(GS_INVOCATION_COUNT),
+	REG64(GS_PRIMITIVES_COUNT),
+	REG64(CL_INVOCATION_COUNT),
+	REG64(CL_PRIMITIVES_COUNT),
+	REG64(PS_INVOCATION_COUNT),
+	REG64(PS_DEPTH_COUNT),
+	REG64_IDX(RING_TIMESTAMP, RENDER_RING_BASE),
+	REG64(MI_PREDICATE_SRC0),
+	REG64(MI_PREDICATE_SRC1),
+	REG32(GEN7_3DPRIM_END_OFFSET),
+	REG32(GEN7_3DPRIM_START_VERTEX),
+	REG32(GEN7_3DPRIM_VERTEX_COUNT),
+	REG32(GEN7_3DPRIM_INSTANCE_COUNT),
+	REG32(GEN7_3DPRIM_START_INSTANCE),
+	REG32(GEN7_3DPRIM_BASE_VERTEX),
+	REG32(GEN7_GPGPU_DISPATCHDIMX),
+	REG32(GEN7_GPGPU_DISPATCHDIMY),
+	REG32(GEN7_GPGPU_DISPATCHDIMZ),
+	REG64_IDX(RING_TIMESTAMP, BSD_RING_BASE),
+	REG64_IDX(GEN7_SO_NUM_PRIMS_WRITTEN, 0),
+	REG64_IDX(GEN7_SO_NUM_PRIMS_WRITTEN, 1),
+	REG64_IDX(GEN7_SO_NUM_PRIMS_WRITTEN, 2),
+	REG64_IDX(GEN7_SO_NUM_PRIMS_WRITTEN, 3),
+	REG64_IDX(GEN7_SO_PRIM_STORAGE_NEEDED, 0),
+	REG64_IDX(GEN7_SO_PRIM_STORAGE_NEEDED, 1),
+	REG64_IDX(GEN7_SO_PRIM_STORAGE_NEEDED, 2),
+	REG64_IDX(GEN7_SO_PRIM_STORAGE_NEEDED, 3),
+	REG32(GEN7_SO_WRITE_OFFSET(0)),
+	REG32(GEN7_SO_WRITE_OFFSET(1)),
+	REG32(GEN7_SO_WRITE_OFFSET(2)),
+	REG32(GEN7_SO_WRITE_OFFSET(3)),
+	REG32(GEN7_L3SQCREG1),
+	REG32(GEN7_L3CNTLREG2),
+	REG32(GEN7_L3CNTLREG3),
+	REG64_IDX(RING_TIMESTAMP, BLT_RING_BASE),
+};
+
+static const struct drm_i915_reg_descriptor hsw_render_regs[] = {
+	REG64_IDX(HSW_CS_GPR, 0),
+	REG64_IDX(HSW_CS_GPR, 1),
+	REG64_IDX(HSW_CS_GPR, 2),
+	REG64_IDX(HSW_CS_GPR, 3),
+	REG64_IDX(HSW_CS_GPR, 4),
+	REG64_IDX(HSW_CS_GPR, 5),
+	REG64_IDX(HSW_CS_GPR, 6),
+	REG64_IDX(HSW_CS_GPR, 7),
+	REG64_IDX(HSW_CS_GPR, 8),
+	REG64_IDX(HSW_CS_GPR, 9),
+	REG64_IDX(HSW_CS_GPR, 10),
+	REG64_IDX(HSW_CS_GPR, 11),
+	REG64_IDX(HSW_CS_GPR, 12),
+	REG64_IDX(HSW_CS_GPR, 13),
+	REG64_IDX(HSW_CS_GPR, 14),
+	REG64_IDX(HSW_CS_GPR, 15),
+	REG32(HSW_SCRATCH1,
+	      .mask = ~HSW_SCRATCH1_L3_DATA_ATOMICS_DISABLE,
+	      .value = 0),
+	REG32(HSW_ROW_CHICKEN3,
+	      .mask = ~(HSW_ROW_CHICKEN3_L3_GLOBAL_ATOMICS_DISABLE << 16 |
+                        HSW_ROW_CHICKEN3_L3_GLOBAL_ATOMICS_DISABLE),
+	      .value = 0),
+};
+
+static const struct drm_i915_reg_descriptor gen7_blt_regs[] = {
+	REG64_IDX(RING_TIMESTAMP, RENDER_RING_BASE),
+	REG64_IDX(RING_TIMESTAMP, BSD_RING_BASE),
+	REG32(BCS_SWCTRL),
+	REG64_IDX(RING_TIMESTAMP, BLT_RING_BASE),
+};
+
+static const struct drm_i915_reg_descriptor gen9_blt_regs[] = {
+	REG64_IDX(RING_TIMESTAMP, RENDER_RING_BASE),
+	REG64_IDX(RING_TIMESTAMP, BSD_RING_BASE),
+	REG32(BCS_SWCTRL),
+	REG64_IDX(RING_TIMESTAMP, BLT_RING_BASE),
+	REG32_IDX(RING_CTX_TIMESTAMP, BLT_RING_BASE),
+	REG64_IDX(BCS_GPR, 0),
+	REG64_IDX(BCS_GPR, 1),
+	REG64_IDX(BCS_GPR, 2),
+	REG64_IDX(BCS_GPR, 3),
+	REG64_IDX(BCS_GPR, 4),
+	REG64_IDX(BCS_GPR, 5),
+	REG64_IDX(BCS_GPR, 6),
+	REG64_IDX(BCS_GPR, 7),
+	REG64_IDX(BCS_GPR, 8),
+	REG64_IDX(BCS_GPR, 9),
+	REG64_IDX(BCS_GPR, 10),
+	REG64_IDX(BCS_GPR, 11),
+	REG64_IDX(BCS_GPR, 12),
+	REG64_IDX(BCS_GPR, 13),
+	REG64_IDX(BCS_GPR, 14),
+	REG64_IDX(BCS_GPR, 15),
+};
+
+#undef REG64
+#undef REG32
+
+struct drm_i915_reg_table {
+	const struct drm_i915_reg_descriptor *regs;
+	int num_regs;
+};
+
+static const struct drm_i915_reg_table ivb_render_reg_tables[] = {
+	{ gen7_render_regs, ARRAY_SIZE(gen7_render_regs) },
+};
+
+static const struct drm_i915_reg_table ivb_blt_reg_tables[] = {
+	{ gen7_blt_regs, ARRAY_SIZE(gen7_blt_regs) },
+};
+
+static const struct drm_i915_reg_table hsw_render_reg_tables[] = {
+	{ gen7_render_regs, ARRAY_SIZE(gen7_render_regs) },
+	{ hsw_render_regs, ARRAY_SIZE(hsw_render_regs) },
+};
+
+static const struct drm_i915_reg_table hsw_blt_reg_tables[] = {
+	{ gen7_blt_regs, ARRAY_SIZE(gen7_blt_regs) },
+};
+
+static const struct drm_i915_reg_table gen9_blt_reg_tables[] = {
+	{ gen9_blt_regs, ARRAY_SIZE(gen9_blt_regs) },
+};
+
+static u32 gen7_render_get_cmd_length_mask(u32 cmd_header)
+{
+	u32 client = cmd_header >> INSTR_CLIENT_SHIFT;
+	u32 subclient =
+		(cmd_header & INSTR_SUBCLIENT_MASK) >> INSTR_SUBCLIENT_SHIFT;
+
+	if (client == INSTR_MI_CLIENT)
+		return 0x3F;
+	else if (client == INSTR_RC_CLIENT) {
+		if (subclient == INSTR_MEDIA_SUBCLIENT)
+			return 0xFFFF;
+		else
+			return 0xFF;
+	}
+
+	DRM_DEBUG_DRIVER("CMD: Abnormal rcs cmd length! 0x%08X\n", cmd_header);
+	return 0;
+}
+
+static u32 gen7_bsd_get_cmd_length_mask(u32 cmd_header)
+{
+	u32 client = cmd_header >> INSTR_CLIENT_SHIFT;
+	u32 subclient =
+		(cmd_header & INSTR_SUBCLIENT_MASK) >> INSTR_SUBCLIENT_SHIFT;
+	u32 op = (cmd_header & INSTR_26_TO_24_MASK) >> INSTR_26_TO_24_SHIFT;
+
+	if (client == INSTR_MI_CLIENT)
+		return 0x3F;
+	else if (client == INSTR_RC_CLIENT) {
+		if (subclient == INSTR_MEDIA_SUBCLIENT) {
+			if (op == 6)
+				return 0xFFFF;
+			else
+				return 0xFFF;
+		} else
+			return 0xFF;
+	}
+
+	DRM_DEBUG_DRIVER("CMD: Abnormal bsd cmd length! 0x%08X\n", cmd_header);
+	return 0;
+}
+
+static u32 gen7_blt_get_cmd_length_mask(u32 cmd_header)
+{
+	u32 client = cmd_header >> INSTR_CLIENT_SHIFT;
+
+	if (client == INSTR_MI_CLIENT)
+		return 0x3F;
+	else if (client == INSTR_BC_CLIENT)
+		return 0xFF;
+
+	DRM_DEBUG_DRIVER("CMD: Abnormal blt cmd length! 0x%08X\n", cmd_header);
+	return 0;
+}
+
+static u32 gen9_blt_get_cmd_length_mask(u32 cmd_header)
+{
+	u32 client = cmd_header >> INSTR_CLIENT_SHIFT;
+
+	if (client == INSTR_MI_CLIENT || client == INSTR_BC_CLIENT)
+		return 0xFF;
+
+	DRM_DEBUG_DRIVER("CMD: Abnormal blt cmd length! 0x%08X\n", cmd_header);
+	return 0;
+}
+
+static bool validate_cmds_sorted(const struct intel_engine_cs *engine,
+				 const struct drm_i915_cmd_table *cmd_tables,
+				 int cmd_table_count)
+{
+	int i;
+	bool ret = true;
+
+	if (!cmd_tables || cmd_table_count == 0)
+		return true;
+
+	for (i = 0; i < cmd_table_count; i++) {
+		const struct drm_i915_cmd_table *table = &cmd_tables[i];
+		u32 previous = 0;
+		int j;
+
+		for (j = 0; j < table->count; j++) {
+			const struct drm_i915_cmd_descriptor *desc =
+				&table->table[j];
+			u32 curr = desc->cmd.value & desc->cmd.mask;
+
+			if (curr < previous) {
+				DRM_ERROR("CMD: %s [%d] command table not sorted: "
+					  "table=%d entry=%d cmd=0x%08X prev=0x%08X\n",
+					  engine->name, engine->id,
+					  i, j, curr, previous);
+				ret = false;
+			}
+
+			previous = curr;
+		}
+	}
+
+	return ret;
+}
+
+static bool check_sorted(const struct intel_engine_cs *engine,
+			 const struct drm_i915_reg_descriptor *reg_table,
+			 int reg_count)
+{
+	int i;
+	u32 previous = 0;
+	bool ret = true;
+
+	for (i = 0; i < reg_count; i++) {
+		u32 curr = i915_mmio_reg_offset(reg_table[i].addr);
+
+		if (curr < previous) {
+			DRM_ERROR("CMD: %s [%d] register table not sorted: "
+				  "entry=%d reg=0x%08X prev=0x%08X\n",
+				  engine->name, engine->id,
+				  i, curr, previous);
+			ret = false;
+		}
+
+		previous = curr;
+	}
+
+	return ret;
+}
+
+static bool validate_regs_sorted(struct intel_engine_cs *engine)
+{
+	int i;
+	const struct drm_i915_reg_table *table;
+
+	for (i = 0; i < engine->reg_table_count; i++) {
+		table = &engine->reg_tables[i];
+		if (!check_sorted(engine, table->regs, table->num_regs))
+			return false;
+	}
+
+	return true;
+}
+
+struct cmd_node {
+	const struct drm_i915_cmd_descriptor *desc;
+	struct hlist_node node;
+};
+
+/*
+ * Different command ranges have different numbers of bits for the opcode. For
+ * example, MI commands use bits 31:23 while 3D commands use bits 31:16. The
+ * problem is that, for example, MI commands use bits 22:16 for other fields
+ * such as GGTT vs PPGTT bits. If we include those bits in the mask then when
+ * we mask a command from a batch it could hash to the wrong bucket due to
+ * non-opcode bits being set. But if we don't include those bits, some 3D
+ * commands may hash to the same bucket due to not including opcode bits that
+ * make the command unique. For now, we will risk hashing to the same bucket.
+ */
+static inline u32 cmd_header_key(u32 x)
+{
+	switch (x >> INSTR_CLIENT_SHIFT) {
+	default:
+	case INSTR_MI_CLIENT:
+		return x >> STD_MI_OPCODE_SHIFT;
+	case INSTR_RC_CLIENT:
+		return x >> STD_3D_OPCODE_SHIFT;
+	case INSTR_BC_CLIENT:
+		return x >> STD_2D_OPCODE_SHIFT;
+	}
+}
+
+static int init_hash_table(struct intel_engine_cs *engine,
+			   const struct drm_i915_cmd_table *cmd_tables,
+			   int cmd_table_count)
+{
+	int i, j;
+
+	hash_init(engine->cmd_hash);
+
+	for (i = 0; i < cmd_table_count; i++) {
+		const struct drm_i915_cmd_table *table = &cmd_tables[i];
+
+		for (j = 0; j < table->count; j++) {
+			const struct drm_i915_cmd_descriptor *desc =
+				&table->table[j];
+			struct cmd_node *desc_node =
+				kmalloc(sizeof(*desc_node), GFP_KERNEL);
+
+			if (!desc_node)
+				return -ENOMEM;
+
+			desc_node->desc = desc;
+			hash_add(engine->cmd_hash, &desc_node->node,
+				 cmd_header_key(desc->cmd.value));
+		}
+	}
+
+	return 0;
+}
+
+static void fini_hash_table(struct intel_engine_cs *engine)
+{
+	struct hlist_node *tmp;
+	struct cmd_node *desc_node;
+	int i;
+
+	hash_for_each_safe(engine->cmd_hash, i, tmp, desc_node, node) {
+		hash_del(&desc_node->node);
+		kfree(desc_node);
+	}
+}
+
+/**
+ * intel_engine_init_cmd_parser() - set cmd parser related fields for an engine
+ * @engine: the engine to initialize
+ *
+ * Optionally initializes fields related to batch buffer command parsing in the
+ * struct intel_engine_cs based on whether the platform requires software
+ * command parsing.
+ */
+void intel_engine_init_cmd_parser(struct intel_engine_cs *engine)
+{
+	const struct drm_i915_cmd_table *cmd_tables;
+	int cmd_table_count;
+	int ret;
+
+	if (!IS_GEN7(engine->i915) && !(IS_GEN9(engine->i915) &&
+					engine->id == BCS))
+		return;
+
+	switch (engine->id) {
+	case RCS:
+		if (IS_HASWELL(engine->i915)) {
+			cmd_tables = hsw_render_ring_cmd_table;
+			cmd_table_count =
+				ARRAY_SIZE(hsw_render_ring_cmd_table);
+		} else {
+			cmd_tables = gen7_render_cmd_table;
+			cmd_table_count = ARRAY_SIZE(gen7_render_cmd_table);
+		}
+
+		if (IS_HASWELL(engine->i915)) {
+			engine->reg_tables = hsw_render_reg_tables;
+			engine->reg_table_count = ARRAY_SIZE(hsw_render_reg_tables);
+		} else {
+			engine->reg_tables = ivb_render_reg_tables;
+			engine->reg_table_count = ARRAY_SIZE(ivb_render_reg_tables);
+		}
+		engine->get_cmd_length_mask = gen7_render_get_cmd_length_mask;
+		break;
+	case VCS:
+		cmd_tables = gen7_video_cmd_table;
+		cmd_table_count = ARRAY_SIZE(gen7_video_cmd_table);
+		engine->get_cmd_length_mask = gen7_bsd_get_cmd_length_mask;
+		break;
+	case BCS:
+		engine->get_cmd_length_mask = gen7_blt_get_cmd_length_mask;
+		if (IS_GEN9(engine->i915)) {
+			cmd_tables = gen9_blt_cmd_table;
+			cmd_table_count = ARRAY_SIZE(gen9_blt_cmd_table);
+			engine->get_cmd_length_mask =
+				gen9_blt_get_cmd_length_mask;
+
+			/* BCS Engine unsafe without parser */
+			engine->flags |= I915_ENGINE_REQUIRES_CMD_PARSER;
+		} else if (IS_HASWELL(engine->i915)) {
+			cmd_tables = hsw_blt_ring_cmd_table;
+			cmd_table_count = ARRAY_SIZE(hsw_blt_ring_cmd_table);
+		} else {
+			cmd_tables = gen7_blt_cmd_table;
+			cmd_table_count = ARRAY_SIZE(gen7_blt_cmd_table);
+		}
+
+		if (IS_GEN9(engine->i915)) {
+			engine->reg_tables = gen9_blt_reg_tables;
+			engine->reg_table_count =
+				ARRAY_SIZE(gen9_blt_reg_tables);
+		} else if (IS_HASWELL(engine->i915)) {
+			engine->reg_tables = hsw_blt_reg_tables;
+			engine->reg_table_count = ARRAY_SIZE(hsw_blt_reg_tables);
+		} else {
+			engine->reg_tables = ivb_blt_reg_tables;
+			engine->reg_table_count = ARRAY_SIZE(ivb_blt_reg_tables);
+		}
+		break;
+	case VECS:
+		cmd_tables = hsw_vebox_cmd_table;
+		cmd_table_count = ARRAY_SIZE(hsw_vebox_cmd_table);
+		/* VECS can use the same length_mask function as VCS */
+		engine->get_cmd_length_mask = gen7_bsd_get_cmd_length_mask;
+		break;
+	default:
+		MISSING_CASE(engine->id);
+		return;
+	}
+
+	if (!validate_cmds_sorted(engine, cmd_tables, cmd_table_count)) {
+		DRM_ERROR("%s: command descriptions are not sorted\n",
+			  engine->name);
+		return;
+	}
+	if (!validate_regs_sorted(engine)) {
+		DRM_ERROR("%s: registers are not sorted\n", engine->name);
+		return;
+	}
+
+	ret = init_hash_table(engine, cmd_tables, cmd_table_count);
+	if (ret) {
+		DRM_ERROR("%s: initialised failed!\n", engine->name);
+		fini_hash_table(engine);
+		return;
+	}
+
+	engine->flags |= I915_ENGINE_USING_CMD_PARSER;
+}
+
+/**
+ * intel_engine_cleanup_cmd_parser() - clean up cmd parser related fields
+ * @engine: the engine to clean up
+ *
+ * Releases any resources related to command parsing that may have been
+ * initialized for the specified engine.
+ */
+void intel_engine_cleanup_cmd_parser(struct intel_engine_cs *engine)
+{
+	if (!intel_engine_using_cmd_parser(engine))
+		return;
+
+	fini_hash_table(engine);
+}
+
+static const struct drm_i915_cmd_descriptor*
+find_cmd_in_table(struct intel_engine_cs *engine,
+		  u32 cmd_header)
+{
+	struct cmd_node *desc_node;
+
+	hash_for_each_possible(engine->cmd_hash, desc_node, node,
+			       cmd_header_key(cmd_header)) {
+		const struct drm_i915_cmd_descriptor *desc = desc_node->desc;
+		if (((cmd_header ^ desc->cmd.value) & desc->cmd.mask) == 0)
+			return desc;
+	}
+
+	return NULL;
+}
+
+/*
+ * Returns a pointer to a descriptor for the command specified by cmd_header.
+ *
+ * The caller must supply space for a default descriptor via the default_desc
+ * parameter. If no descriptor for the specified command exists in the engine's
+ * command parser tables, this function fills in default_desc based on the
+ * engine's default length encoding and returns default_desc.
+ */
+static const struct drm_i915_cmd_descriptor*
+find_cmd(struct intel_engine_cs *engine,
+	 u32 cmd_header,
+	 const struct drm_i915_cmd_descriptor *desc,
+	 struct drm_i915_cmd_descriptor *default_desc)
+{
+	u32 mask;
+
+	if (((cmd_header ^ desc->cmd.value) & desc->cmd.mask) == 0)
+		return desc;
+
+	desc = find_cmd_in_table(engine, cmd_header);
+	if (desc)
+		return desc;
+
+	mask = engine->get_cmd_length_mask(cmd_header);
+	if (!mask)
+		return NULL;
+
+	default_desc->cmd.value = cmd_header;
+	default_desc->cmd.mask = ~0u << MIN_OPCODE_SHIFT;
+	default_desc->length.mask = mask;
+	default_desc->flags = CMD_DESC_SKIP;
+	return default_desc;
+}
+
+static const struct drm_i915_reg_descriptor *
+__find_reg(const struct drm_i915_reg_descriptor *table, int count, u32 addr)
+{
+	int start = 0, end = count;
+	while (start < end) {
+		int mid = start + (end - start) / 2;
+		int ret = addr - i915_mmio_reg_offset(table[mid].addr);
+		if (ret < 0)
+			end = mid;
+		else if (ret > 0)
+			start = mid + 1;
+		else
+			return &table[mid];
+	}
+	return NULL;
+}
+
+static const struct drm_i915_reg_descriptor *
+find_reg(const struct intel_engine_cs *engine, u32 addr)
+{
+	const struct drm_i915_reg_table *table = engine->reg_tables;
+	const struct drm_i915_reg_descriptor *reg = NULL;
+	int count = engine->reg_table_count;
+
+	for (; !reg && (count > 0); ++table, --count)
+		reg = __find_reg(table->regs, table->num_regs, addr);
+
+	return reg;
+}
+
+/* Returns a vmap'd pointer to dst_obj, which the caller must unmap */
+static u32 *copy_batch(struct drm_i915_gem_object *dst_obj,
+		       struct drm_i915_gem_object *src_obj,
+		       u32 batch_start_offset,
+		       u32 batch_len,
+		       bool *needs_clflush_after)
+{
+	unsigned int src_needs_clflush;
+	unsigned int dst_needs_clflush;
+	void *dst, *src;
+	int ret;
+
+	ret = i915_gem_obj_prepare_shmem_read(src_obj, &src_needs_clflush);
+	if (ret)
+		return ERR_PTR(ret);
+
+	ret = i915_gem_obj_prepare_shmem_write(dst_obj, &dst_needs_clflush);
+	if (ret) {
+		dst = ERR_PTR(ret);
+		goto unpin_src;
+	}
+
+	dst = i915_gem_object_pin_map(dst_obj, I915_MAP_FORCE_WB);
+	if (IS_ERR(dst))
+		goto unpin_dst;
+
+	src = ERR_PTR(-ENODEV);
+	if (src_needs_clflush &&
+	    i915_can_memcpy_from_wc(NULL, batch_start_offset, 0)) {
+		src = i915_gem_object_pin_map(src_obj, I915_MAP_WC);
+		if (!IS_ERR(src)) {
+			i915_memcpy_from_wc(dst,
+					    src + batch_start_offset,
+					    ALIGN(batch_len, 16));
+			i915_gem_object_unpin_map(src_obj);
+		}
+	}
+	if (IS_ERR(src)) {
+		void *ptr;
+		int offset, n;
+
+		offset = offset_in_page(batch_start_offset);
+
+		/* We can avoid clflushing partial cachelines before the write
+		 * if we only every write full cache-lines. Since we know that
+		 * both the source and destination are in multiples of
+		 * PAGE_SIZE, we can simply round up to the next cacheline.
+		 * We don't care about copying too much here as we only
+		 * validate up to the end of the batch.
+		 */
+		if (dst_needs_clflush & CLFLUSH_BEFORE)
+			batch_len = roundup(batch_len,
+					    boot_cpu_data.x86_clflush_size);
+
+		ptr = dst;
+		for (n = batch_start_offset >> PAGE_SHIFT; batch_len; n++) {
+			int len = min_t(int, batch_len, PAGE_SIZE - offset);
+
+			src = kmap_atomic(i915_gem_object_get_page(src_obj, n));
+			if (src_needs_clflush)
+				drm_clflush_virt_range(src + offset, len);
+			memcpy(ptr, src + offset, len);
+			kunmap_atomic(src);
+
+			ptr += len;
+			batch_len -= len;
+			offset = 0;
+		}
+	}
+
+	/* dst_obj is returned with vmap pinned */
+	*needs_clflush_after = dst_needs_clflush & CLFLUSH_AFTER;
+
+unpin_dst:
+	i915_gem_obj_finish_shmem_access(dst_obj);
+unpin_src:
+	i915_gem_obj_finish_shmem_access(src_obj);
+	return dst;
+}
+
+static bool check_cmd(const struct intel_engine_cs *engine,
+		      const struct drm_i915_cmd_descriptor *desc,
+		      const u32 *cmd, u32 length)
+{
+	if (desc->flags & CMD_DESC_SKIP)
+		return true;
+
+	if (desc->flags & CMD_DESC_REJECT) {
+		DRM_DEBUG_DRIVER("CMD: Rejected command: 0x%08X\n", *cmd);
+		return false;
+	}
+
+	if (desc->flags & CMD_DESC_REGISTER) {
+		/*
+		 * Get the distance between individual register offset
+		 * fields if the command can perform more than one
+		 * access at a time.
+		 */
+		const u32 step = desc->reg.step ? desc->reg.step : length;
+		u32 offset;
+
+		for (offset = desc->reg.offset; offset < length;
+		     offset += step) {
+			const u32 reg_addr = cmd[offset] & desc->reg.mask;
+			const struct drm_i915_reg_descriptor *reg =
+				find_reg(engine, reg_addr);
+
+			if (!reg) {
+				DRM_DEBUG_DRIVER("CMD: Rejected register 0x%08X in command: 0x%08X (%s)\n",
+						 reg_addr, *cmd, engine->name);
+				return false;
+			}
+
+			/*
+			 * Check the value written to the register against the
+			 * allowed mask/value pair given in the whitelist entry.
+			 */
+			if (reg->mask) {
+				if (desc->cmd.value == MI_LOAD_REGISTER_MEM) {
+					DRM_DEBUG_DRIVER("CMD: Rejected LRM to masked register 0x%08X\n",
+							 reg_addr);
+					return false;
+				}
+
+				if (desc->cmd.value == MI_LOAD_REGISTER_REG) {
+					DRM_DEBUG_DRIVER("CMD: Rejected LRR to masked register 0x%08X\n",
+							 reg_addr);
+					return false;
+				}
+
+				if (desc->cmd.value == MI_LOAD_REGISTER_IMM(1) &&
+				    (offset + 2 > length ||
+				     (cmd[offset + 1] & reg->mask) != reg->value)) {
+					DRM_DEBUG_DRIVER("CMD: Rejected LRI to masked register 0x%08X\n",
+							 reg_addr);
+					return false;
+				}
+			}
+		}
+	}
+
+	if (desc->flags & CMD_DESC_BITMASK) {
+		int i;
+
+		for (i = 0; i < MAX_CMD_DESC_BITMASKS; i++) {
+			u32 dword;
+
+			if (desc->bits[i].mask == 0)
+				break;
+
+			if (desc->bits[i].condition_mask != 0) {
+				u32 offset =
+					desc->bits[i].condition_offset;
+				u32 condition = cmd[offset] &
+					desc->bits[i].condition_mask;
+
+				if (condition == 0)
+					continue;
+			}
+
+			if (desc->bits[i].offset >= length) {
+				DRM_DEBUG_DRIVER("CMD: Rejected command 0x%08X, too short to check bitmask (%s)\n",
+						 *cmd, engine->name);
+				return false;
+			}
+
+			dword = cmd[desc->bits[i].offset] &
+				desc->bits[i].mask;
+
+			if (dword != desc->bits[i].expected) {
+				DRM_DEBUG_DRIVER("CMD: Rejected command 0x%08X for bitmask 0x%08X (exp=0x%08X act=0x%08X) (%s)\n",
+						 *cmd,
+						 desc->bits[i].mask,
+						 desc->bits[i].expected,
+						 dword, engine->name);
+				return false;
+			}
+		}
+	}
+
+	return true;
+}
+
+static int check_bbstart(const struct i915_gem_context *ctx,
+			 u32 *cmd, u32 offset, u32 length,
+			 u32 batch_len,
+			 u64 batch_start,
+			 u64 shadow_batch_start)
+{
+	u64 jump_offset, jump_target;
+	u32 target_cmd_offset, target_cmd_index;
+
+	/* For igt compatibility on older platforms */
+	if (CMDPARSER_USES_GGTT(ctx->i915)) {
+		DRM_DEBUG("CMD: Rejecting BB_START for ggtt based submission\n");
+		return -EACCES;
+	}
+
+	if (length != 3) {
+		DRM_DEBUG("CMD: Recursive BB_START with bad length(%u)\n",
+			  length);
+		return -EINVAL;
+	}
+
+	jump_target = *(u64*)(cmd+1);
+	jump_offset = jump_target - batch_start;
+
+	/*
+	 * Any underflow of jump_target is guaranteed to be outside the range
+	 * of a u32, so >= test catches both too large and too small
+	 */
+	if (jump_offset >= batch_len) {
+		DRM_DEBUG("CMD: BB_START to 0x%llx jumps out of BB\n",
+			  jump_target);
+		return -EINVAL;
+	}
+
+	/*
+	 * This cannot overflow a u32 because we already checked jump_offset
+	 * is within the BB, and the batch_len is a u32
+	 */
+	target_cmd_offset = lower_32_bits(jump_offset);
+	target_cmd_index = target_cmd_offset / sizeof(u32);
+
+	*(u64*)(cmd + 1) = shadow_batch_start + target_cmd_offset;
+
+	if (target_cmd_index == offset)
+		return 0;
+
+	if (ctx->jump_whitelist_cmds <= target_cmd_index) {
+		DRM_DEBUG("CMD: Rejecting BB_START - truncated whitelist array\n");
+		return -EINVAL;
+	} else if (!test_bit(target_cmd_index, ctx->jump_whitelist)) {
+		DRM_DEBUG("CMD: BB_START to 0x%llx not a previously executed cmd\n",
+			  jump_target);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static void init_whitelist(struct i915_gem_context *ctx, u32 batch_len)
+{
+	const u32 batch_cmds = DIV_ROUND_UP(batch_len, sizeof(u32));
+	const u32 exact_size = BITS_TO_LONGS(batch_cmds);
+	u32 next_size = BITS_TO_LONGS(roundup_pow_of_two(batch_cmds));
+	unsigned long *next_whitelist;
+
+	if (CMDPARSER_USES_GGTT(ctx->i915))
+		return;
+
+	if (batch_cmds <= ctx->jump_whitelist_cmds) {
+		bitmap_zero(ctx->jump_whitelist, batch_cmds);
+		return;
+	}
+
+again:
+	next_whitelist = kcalloc(next_size, sizeof(long), GFP_KERNEL);
+	if (next_whitelist) {
+		kfree(ctx->jump_whitelist);
+		ctx->jump_whitelist = next_whitelist;
+		ctx->jump_whitelist_cmds =
+			next_size * BITS_PER_BYTE * sizeof(long);
+		return;
+	}
+
+	if (next_size > exact_size) {
+		next_size = exact_size;
+		goto again;
+	}
+
+	DRM_DEBUG("CMD: Failed to extend whitelist. BB_START may be disallowed\n");
+	bitmap_zero(ctx->jump_whitelist, ctx->jump_whitelist_cmds);
+
+	return;
+}
+
+#define LENGTH_BIAS 2
+
+/**
+ * i915_parse_cmds() - parse a submitted batch buffer for privilege violations
+ * @ctx: the context in which the batch is to execute
+ * @engine: the engine on which the batch is to execute
+ * @batch_obj: the batch buffer in question
+ * @batch_start: Canonical base address of batch
+ * @batch_start_offset: byte offset in the batch at which execution starts
+ * @batch_len: length of the commands in batch_obj
+ * @shadow_batch_obj: copy of the batch buffer in question
+ * @shadow_batch_start: Canonical base address of shadow_batch_obj
+ *
+ * Parses the specified batch buffer looking for privilege violations as
+ * described in the overview.
+ *
+ * Return: non-zero if the parser finds violations or otherwise fails; -EACCES
+ * if the batch appears legal but should use hardware parsing
+ */
+
+int intel_engine_cmd_parser(struct i915_gem_context *ctx,
+			    struct intel_engine_cs *engine,
+			    struct drm_i915_gem_object *batch_obj,
+			    u64 batch_start,
+			    u32 batch_start_offset,
+			    u32 batch_len,
+			    struct drm_i915_gem_object *shadow_batch_obj,
+			    u64 shadow_batch_start)
+{
+	u32 *cmd, *batch_end, offset = 0;
+	struct drm_i915_cmd_descriptor default_desc = noop_desc;
+	const struct drm_i915_cmd_descriptor *desc = &default_desc;
+	bool needs_clflush_after = false;
+	int ret = 0;
+
+	cmd = copy_batch(shadow_batch_obj, batch_obj,
+			 batch_start_offset, batch_len,
+			 &needs_clflush_after);
+	if (IS_ERR(cmd)) {
+		DRM_DEBUG_DRIVER("CMD: Failed to copy batch\n");
+		return PTR_ERR(cmd);
+	}
+
+	init_whitelist(ctx, batch_len);
+
+	/*
+	 * We use the batch length as size because the shadow object is as
+	 * large or larger and copy_batch() will write MI_NOPs to the extra
+	 * space. Parsing should be faster in some cases this way.
+	 */
+	batch_end = cmd + (batch_len / sizeof(*batch_end));
+	do {
+		u32 length;
+
+		if (*cmd == MI_BATCH_BUFFER_END)
+			break;
+
+		desc = find_cmd(engine, *cmd, desc, &default_desc);
+		if (!desc) {
+			DRM_DEBUG_DRIVER("CMD: Unrecognized command: 0x%08X\n",
+					 *cmd);
+			ret = -EINVAL;
+			goto err;
+		}
+
+		if (desc->flags & CMD_DESC_FIXED)
+			length = desc->length.fixed;
+		else
+			length = ((*cmd & desc->length.mask) + LENGTH_BIAS);
+
+		if ((batch_end - cmd) < length) {
+			DRM_DEBUG_DRIVER("CMD: Command length exceeds batch length: 0x%08X length=%u batchlen=%td\n",
+					 *cmd,
+					 length,
+					 batch_end - cmd);
+			ret = -EINVAL;
+			goto err;
+		}
+
+		if (!check_cmd(engine, desc, cmd, length)) {
+			ret = -EACCES;
+			goto err;
+		}
+
+		if (desc->cmd.value == MI_BATCH_BUFFER_START) {
+			ret = check_bbstart(ctx, cmd, offset, length,
+					    batch_len, batch_start,
+					    shadow_batch_start);
+
+			if (ret)
+				goto err;
+			break;
+		}
+
+		if (ctx->jump_whitelist_cmds > offset)
+			set_bit(offset, ctx->jump_whitelist);
+
+		cmd += length;
+		offset += length;
+		if  (cmd >= batch_end) {
+			DRM_DEBUG_DRIVER("CMD: Got to the end of the buffer w/o a BBE cmd!\n");
+			ret = -EINVAL;
+			goto err;
+		}
+	} while (1);
+
+	if (needs_clflush_after) {
+		void *ptr = page_mask_bits(shadow_batch_obj->mm.mapping);
+
+		drm_clflush_virt_range(ptr, (void *)(cmd + 1) - ptr);
+	}
+
+err:
+	i915_gem_object_unpin_map(shadow_batch_obj);
+	return ret;
+}
+
+/**
+ * i915_cmd_parser_get_version() - get the cmd parser version number
+ * @dev_priv: i915 device private
+ *
+ * The cmd parser maintains a simple increasing integer version number suitable
+ * for passing to userspace clients to determine what operations are permitted.
+ *
+ * Return: the current version number of the cmd parser
+ */
+int i915_cmd_parser_get_version(struct drm_i915_private *dev_priv)
+{
+	struct intel_engine_cs *engine;
+	enum intel_engine_id id;
+	bool active = false;
+
+	/* If the command parser is not enabled, report 0 - unsupported */
+	for_each_engine(engine, dev_priv, id) {
+		if (intel_engine_using_cmd_parser(engine)) {
+			active = true;
+			break;
+		}
+	}
+	if (!active)
+		return 0;
+
+	/*
+	 * Command parser version history
+	 *
+	 * 1. Initial version. Checks batches and reports violations, but leaves
+	 *    hardware parsing enabled (so does not allow new use cases).
+	 * 2. Allow access to the MI_PREDICATE_SRC0 and
+	 *    MI_PREDICATE_SRC1 registers.
+	 * 3. Allow access to the GPGPU_THREADS_DISPATCHED register.
+	 * 4. L3 atomic chicken bits of HSW_SCRATCH1 and HSW_ROW_CHICKEN3.
+	 * 5. GPGPU dispatch compute indirect registers.
+	 * 6. TIMESTAMP register and Haswell CS GPR registers
+	 * 7. Allow MI_LOAD_REGISTER_REG between whitelisted registers.
+	 * 8. Don't report cmd_check() failures as EINVAL errors to userspace;
+	 *    rely on the HW to NOOP disallowed commands as it would without
+	 *    the parser enabled.
+	 * 9. Don't whitelist or handle oacontrol specially, as ownership
+	 *    for oacontrol state is moving to i915-perf.
+	 * 10. Support for Gen9 BCS Parsing
+	 */
+	return 10;
+}