xref: /linux/drivers/gpu/drm/i915/i915_cmd_parser.c (revision 815e260a18a3af4dab59025ee99a7156c0e8b5e0)
1 /*
2  * Copyright © 2013 Intel Corporation
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice (including the next
12  * paragraph) shall be included in all copies or substantial portions of the
13  * Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21  * IN THE SOFTWARE.
22  *
23  * Authors:
24  *    Brad Volkin <bradley.d.volkin@intel.com>
25  *
26  */
27 
28 #include <linux/highmem.h>
29 
30 #include <drm/drm_cache.h>
31 #include <drm/drm_print.h>
32 
33 #include "gt/intel_engine.h"
34 #include "gt/intel_engine_regs.h"
35 #include "gt/intel_gpu_commands.h"
36 #include "gt/intel_gt_regs.h"
37 
38 #include "i915_cmd_parser.h"
39 #include "i915_drv.h"
40 #include "i915_memcpy.h"
41 #include "i915_reg.h"
42 
43 /**
44  * DOC: batch buffer command parser
45  *
46  * Motivation:
47  * Certain OpenGL features (e.g. transform feedback, performance monitoring)
48  * require userspace code to submit batches containing commands such as
49  * MI_LOAD_REGISTER_IMM to access various registers. Unfortunately, some
50  * generations of the hardware will noop these commands in "unsecure" batches
51  * (which includes all userspace batches submitted via i915) even though the
52  * commands may be safe and represent the intended programming model of the
53  * device.
54  *
55  * The software command parser is similar in operation to the command parsing
56  * done in hardware for unsecure batches. However, the software parser allows
57  * some operations that would be noop'd by hardware, if the parser determines
58  * the operation is safe, and submits the batch as "secure" to prevent hardware
59  * parsing.
60  *
61  * Threats:
62  * At a high level, the hardware (and software) checks attempt to prevent
63  * granting userspace undue privileges. There are three categories of privilege.
64  *
65  * First, commands which are explicitly defined as privileged or which should
66  * only be used by the kernel driver. The parser rejects such commands
67  *
68  * Second, commands which access registers. To support correct/enhanced
69  * userspace functionality, particularly certain OpenGL extensions, the parser
70  * provides a whitelist of registers which userspace may safely access
71  *
72  * Third, commands which access privileged memory (i.e. GGTT, HWS page, etc).
73  * The parser always rejects such commands.
74  *
75  * The majority of the problematic commands fall in the MI_* range, with only a
76  * few specific commands on each engine (e.g. PIPE_CONTROL and MI_FLUSH_DW).
77  *
78  * Implementation:
79  * Each engine maintains tables of commands and registers which the parser
80  * uses in scanning batch buffers submitted to that engine.
81  *
82  * Since the set of commands that the parser must check for is significantly
83  * smaller than the number of commands supported, the parser tables contain only
84  * those commands required by the parser. This generally works because command
85  * opcode ranges have standard command length encodings. So for commands that
86  * the parser does not need to check, it can easily skip them. This is
87  * implemented via a per-engine length decoding vfunc.
88  *
89  * Unfortunately, there are a number of commands that do not follow the standard
90  * length encoding for their opcode range, primarily amongst the MI_* commands.
91  * To handle this, the parser provides a way to define explicit "skip" entries
92  * in the per-engine command tables.
93  *
94  * Other command table entries map fairly directly to high level categories
95  * mentioned above: rejected, register whitelist. The parser implements a number
96  * of checks, including the privileged memory checks, via a general bitmasking
97  * mechanism.
98  */
99 
100 /*
101  * A command that requires special handling by the command parser.
102  */
103 struct drm_i915_cmd_descriptor {
104 	/*
105 	 * Flags describing how the command parser processes the command.
106 	 *
107 	 * CMD_DESC_FIXED: The command has a fixed length if this is set,
108 	 *                 a length mask if not set
109 	 * CMD_DESC_SKIP: The command is allowed but does not follow the
110 	 *                standard length encoding for the opcode range in
111 	 *                which it falls
112 	 * CMD_DESC_REJECT: The command is never allowed
113 	 * CMD_DESC_REGISTER: The command should be checked against the
114 	 *                    register whitelist for the appropriate ring
115 	 */
116 	u32 flags;
117 #define CMD_DESC_FIXED    (1<<0)
118 #define CMD_DESC_SKIP     (1<<1)
119 #define CMD_DESC_REJECT   (1<<2)
120 #define CMD_DESC_REGISTER (1<<3)
121 #define CMD_DESC_BITMASK  (1<<4)
122 
123 	/*
124 	 * The command's unique identification bits and the bitmask to get them.
125 	 * This isn't strictly the opcode field as defined in the spec and may
126 	 * also include type, subtype, and/or subop fields.
127 	 */
128 	struct {
129 		u32 value;
130 		u32 mask;
131 	} cmd;
132 
133 	/*
134 	 * The command's length. The command is either fixed length (i.e. does
135 	 * not include a length field) or has a length field mask. The flag
136 	 * CMD_DESC_FIXED indicates a fixed length. Otherwise, the command has
137 	 * a length mask. All command entries in a command table must include
138 	 * length information.
139 	 */
140 	union {
141 		u32 fixed;
142 		u32 mask;
143 	} length;
144 
145 	/*
146 	 * Describes where to find a register address in the command to check
147 	 * against the ring's register whitelist. Only valid if flags has the
148 	 * CMD_DESC_REGISTER bit set.
149 	 *
150 	 * A non-zero step value implies that the command may access multiple
151 	 * registers in sequence (e.g. LRI), in that case step gives the
152 	 * distance in dwords between individual offset fields.
153 	 */
154 	struct {
155 		u32 offset;
156 		u32 mask;
157 		u32 step;
158 	} reg;
159 
160 #define MAX_CMD_DESC_BITMASKS 3
161 	/*
162 	 * Describes command checks where a particular dword is masked and
163 	 * compared against an expected value. If the command does not match
164 	 * the expected value, the parser rejects it. Only valid if flags has
165 	 * the CMD_DESC_BITMASK bit set. Only entries where mask is non-zero
166 	 * are valid.
167 	 *
168 	 * If the check specifies a non-zero condition_mask then the parser
169 	 * only performs the check when the bits specified by condition_mask
170 	 * are non-zero.
171 	 */
172 	struct {
173 		u32 offset;
174 		u32 mask;
175 		u32 expected;
176 		u32 condition_offset;
177 		u32 condition_mask;
178 	} bits[MAX_CMD_DESC_BITMASKS];
179 };
180 
181 /*
182  * A table of commands requiring special handling by the command parser.
183  *
184  * Each engine has an array of tables. Each table consists of an array of
185  * command descriptors, which must be sorted with command opcodes in
186  * ascending order.
187  */
188 struct drm_i915_cmd_table {
189 	const struct drm_i915_cmd_descriptor *table;
190 	int count;
191 };
192 
193 #define STD_MI_OPCODE_SHIFT  (32 - 9)
194 #define STD_3D_OPCODE_SHIFT  (32 - 16)
195 #define STD_2D_OPCODE_SHIFT  (32 - 10)
196 #define STD_MFX_OPCODE_SHIFT (32 - 16)
197 #define MIN_OPCODE_SHIFT 16
198 
199 #define CMD(op, opm, f, lm, fl, ...)				\
200 	{							\
201 		.flags = (fl) | ((f) ? CMD_DESC_FIXED : 0),	\
202 		.cmd = { (op & ~0u << (opm)), ~0u << (opm) },	\
203 		.length = { (lm) },				\
204 		__VA_ARGS__					\
205 	}
206 
207 /* Convenience macros to compress the tables */
208 #define SMI STD_MI_OPCODE_SHIFT
209 #define S3D STD_3D_OPCODE_SHIFT
210 #define S2D STD_2D_OPCODE_SHIFT
211 #define SMFX STD_MFX_OPCODE_SHIFT
212 #define F true
213 #define S CMD_DESC_SKIP
214 #define R CMD_DESC_REJECT
215 #define W CMD_DESC_REGISTER
216 #define B CMD_DESC_BITMASK
217 
218 /*            Command                          Mask   Fixed Len   Action
219 	      ---------------------------------------------------------- */
220 static const struct drm_i915_cmd_descriptor gen7_common_cmds[] = {
221 	CMD(  MI_NOOP,                          SMI,    F,  1,      S  ),
222 	CMD(  MI_USER_INTERRUPT,                SMI,    F,  1,      R  ),
223 	CMD(  MI_WAIT_FOR_EVENT,                SMI,    F,  1,      R  ),
224 	CMD(  MI_ARB_CHECK,                     SMI,    F,  1,      S  ),
225 	CMD(  MI_REPORT_HEAD,                   SMI,    F,  1,      S  ),
226 	CMD(  MI_SUSPEND_FLUSH,                 SMI,    F,  1,      S  ),
227 	CMD(  MI_SEMAPHORE_MBOX,                SMI,   !F,  0xFF,   R  ),
228 	CMD(  MI_STORE_DWORD_INDEX,             SMI,   !F,  0xFF,   R  ),
229 	CMD(  MI_LOAD_REGISTER_IMM(1),          SMI,   !F,  0xFF,   W,
230 	      .reg = { .offset = 1, .mask = 0x007FFFFC, .step = 2 }    ),
231 	CMD(  MI_STORE_REGISTER_MEM,            SMI,    F,  3,     W | B,
232 	      .reg = { .offset = 1, .mask = 0x007FFFFC },
233 	      .bits = {{
234 			.offset = 0,
235 			.mask = MI_GLOBAL_GTT,
236 			.expected = 0,
237 	      }},						       ),
238 	CMD(  MI_LOAD_REGISTER_MEM,             SMI,    F,  3,     W | B,
239 	      .reg = { .offset = 1, .mask = 0x007FFFFC },
240 	      .bits = {{
241 			.offset = 0,
242 			.mask = MI_GLOBAL_GTT,
243 			.expected = 0,
244 	      }},						       ),
245 	/*
246 	 * MI_BATCH_BUFFER_START requires some special handling. It's not
247 	 * really a 'skip' action but it doesn't seem like it's worth adding
248 	 * a new action. See intel_engine_cmd_parser().
249 	 */
250 	CMD(  MI_BATCH_BUFFER_START,            SMI,   !F,  0xFF,   S  ),
251 };
252 
253 static const struct drm_i915_cmd_descriptor gen7_render_cmds[] = {
254 	CMD(  MI_FLUSH,                         SMI,    F,  1,      S  ),
255 	CMD(  MI_ARB_ON_OFF,                    SMI,    F,  1,      R  ),
256 	CMD(  MI_PREDICATE,                     SMI,    F,  1,      S  ),
257 	CMD(  MI_TOPOLOGY_FILTER,               SMI,    F,  1,      S  ),
258 	CMD(  MI_SET_APPID,                     SMI,    F,  1,      S  ),
259 	CMD(  MI_DISPLAY_FLIP,                  SMI,   !F,  0xFF,   R  ),
260 	CMD(  MI_SET_CONTEXT,                   SMI,   !F,  0xFF,   R  ),
261 	CMD(  MI_URB_CLEAR,                     SMI,   !F,  0xFF,   S  ),
262 	CMD(  MI_STORE_DWORD_IMM,               SMI,   !F,  0x3F,   B,
263 	      .bits = {{
264 			.offset = 0,
265 			.mask = MI_GLOBAL_GTT,
266 			.expected = 0,
267 	      }},						       ),
268 	CMD(  MI_UPDATE_GTT,                    SMI,   !F,  0xFF,   R  ),
269 	CMD(  MI_CLFLUSH,                       SMI,   !F,  0x3FF,  B,
270 	      .bits = {{
271 			.offset = 0,
272 			.mask = MI_GLOBAL_GTT,
273 			.expected = 0,
274 	      }},						       ),
275 	CMD(  MI_REPORT_PERF_COUNT,             SMI,   !F,  0x3F,   B,
276 	      .bits = {{
277 			.offset = 1,
278 			.mask = MI_REPORT_PERF_COUNT_GGTT,
279 			.expected = 0,
280 	      }},						       ),
281 	CMD(  MI_CONDITIONAL_BATCH_BUFFER_END,  SMI,   !F,  0xFF,   B,
282 	      .bits = {{
283 			.offset = 0,
284 			.mask = MI_GLOBAL_GTT,
285 			.expected = 0,
286 	      }},						       ),
287 	CMD(  GFX_OP_3DSTATE_VF_STATISTICS,     S3D,    F,  1,      S  ),
288 	CMD(  PIPELINE_SELECT,                  S3D,    F,  1,      S  ),
289 	CMD(  MEDIA_VFE_STATE,			S3D,   !F,  0xFFFF, B,
290 	      .bits = {{
291 			.offset = 2,
292 			.mask = MEDIA_VFE_STATE_MMIO_ACCESS_MASK,
293 			.expected = 0,
294 	      }},						       ),
295 	CMD(  GPGPU_OBJECT,                     S3D,   !F,  0xFF,   S  ),
296 	CMD(  GPGPU_WALKER,                     S3D,   !F,  0xFF,   S  ),
297 	CMD(  GFX_OP_3DSTATE_SO_DECL_LIST,      S3D,   !F,  0x1FF,  S  ),
298 	CMD(  GFX_OP_PIPE_CONTROL(5),           S3D,   !F,  0xFF,   B,
299 	      .bits = {{
300 			.offset = 1,
301 			.mask = (PIPE_CONTROL_MMIO_WRITE | PIPE_CONTROL_NOTIFY),
302 			.expected = 0,
303 	      },
304 	      {
305 			.offset = 1,
306 		        .mask = (PIPE_CONTROL_GLOBAL_GTT_IVB |
307 				 PIPE_CONTROL_STORE_DATA_INDEX),
308 			.expected = 0,
309 			.condition_offset = 1,
310 			.condition_mask = PIPE_CONTROL_POST_SYNC_OP_MASK,
311 	      }},						       ),
312 };
313 
314 static const struct drm_i915_cmd_descriptor hsw_render_cmds[] = {
315 	CMD(  MI_SET_PREDICATE,                 SMI,    F,  1,      S  ),
316 	CMD(  MI_RS_CONTROL,                    SMI,    F,  1,      S  ),
317 	CMD(  MI_URB_ATOMIC_ALLOC,              SMI,    F,  1,      S  ),
318 	CMD(  MI_SET_APPID,                     SMI,    F,  1,      S  ),
319 	CMD(  MI_RS_CONTEXT,                    SMI,    F,  1,      S  ),
320 	CMD(  MI_LOAD_SCAN_LINES_INCL,          SMI,   !F,  0x3F,   R  ),
321 	CMD(  MI_LOAD_SCAN_LINES_EXCL,          SMI,   !F,  0x3F,   R  ),
322 	CMD(  MI_LOAD_REGISTER_REG,             SMI,   !F,  0xFF,   W,
323 	      .reg = { .offset = 1, .mask = 0x007FFFFC, .step = 1 }    ),
324 	CMD(  MI_RS_STORE_DATA_IMM,             SMI,   !F,  0xFF,   S  ),
325 	CMD(  MI_LOAD_URB_MEM,                  SMI,   !F,  0xFF,   S  ),
326 	CMD(  MI_STORE_URB_MEM,                 SMI,   !F,  0xFF,   S  ),
327 	CMD(  GFX_OP_3DSTATE_DX9_CONSTANTF_VS,  S3D,   !F,  0x7FF,  S  ),
328 	CMD(  GFX_OP_3DSTATE_DX9_CONSTANTF_PS,  S3D,   !F,  0x7FF,  S  ),
329 
330 	CMD(  GFX_OP_3DSTATE_BINDING_TABLE_EDIT_VS,  S3D,   !F,  0x1FF,  S  ),
331 	CMD(  GFX_OP_3DSTATE_BINDING_TABLE_EDIT_GS,  S3D,   !F,  0x1FF,  S  ),
332 	CMD(  GFX_OP_3DSTATE_BINDING_TABLE_EDIT_HS,  S3D,   !F,  0x1FF,  S  ),
333 	CMD(  GFX_OP_3DSTATE_BINDING_TABLE_EDIT_DS,  S3D,   !F,  0x1FF,  S  ),
334 	CMD(  GFX_OP_3DSTATE_BINDING_TABLE_EDIT_PS,  S3D,   !F,  0x1FF,  S  ),
335 };
336 
337 static const struct drm_i915_cmd_descriptor gen7_video_cmds[] = {
338 	CMD(  MI_ARB_ON_OFF,                    SMI,    F,  1,      R  ),
339 	CMD(  MI_SET_APPID,                     SMI,    F,  1,      S  ),
340 	CMD(  MI_STORE_DWORD_IMM,               SMI,   !F,  0xFF,   B,
341 	      .bits = {{
342 			.offset = 0,
343 			.mask = MI_GLOBAL_GTT,
344 			.expected = 0,
345 	      }},						       ),
346 	CMD(  MI_UPDATE_GTT,                    SMI,   !F,  0x3F,   R  ),
347 	CMD(  MI_FLUSH_DW,                      SMI,   !F,  0x3F,   B,
348 	      .bits = {{
349 			.offset = 0,
350 			.mask = MI_FLUSH_DW_NOTIFY,
351 			.expected = 0,
352 	      },
353 	      {
354 			.offset = 1,
355 			.mask = MI_FLUSH_DW_USE_GTT,
356 			.expected = 0,
357 			.condition_offset = 0,
358 			.condition_mask = MI_FLUSH_DW_OP_MASK,
359 	      },
360 	      {
361 			.offset = 0,
362 			.mask = MI_FLUSH_DW_STORE_INDEX,
363 			.expected = 0,
364 			.condition_offset = 0,
365 			.condition_mask = MI_FLUSH_DW_OP_MASK,
366 	      }},						       ),
367 	CMD(  MI_CONDITIONAL_BATCH_BUFFER_END,  SMI,   !F,  0xFF,   B,
368 	      .bits = {{
369 			.offset = 0,
370 			.mask = MI_GLOBAL_GTT,
371 			.expected = 0,
372 	      }},						       ),
373 	/*
374 	 * MFX_WAIT doesn't fit the way we handle length for most commands.
375 	 * It has a length field but it uses a non-standard length bias.
376 	 * It is always 1 dword though, so just treat it as fixed length.
377 	 */
378 	CMD(  MFX_WAIT,                         SMFX,   F,  1,      S  ),
379 };
380 
381 static const struct drm_i915_cmd_descriptor gen7_vecs_cmds[] = {
382 	CMD(  MI_ARB_ON_OFF,                    SMI,    F,  1,      R  ),
383 	CMD(  MI_SET_APPID,                     SMI,    F,  1,      S  ),
384 	CMD(  MI_STORE_DWORD_IMM,               SMI,   !F,  0xFF,   B,
385 	      .bits = {{
386 			.offset = 0,
387 			.mask = MI_GLOBAL_GTT,
388 			.expected = 0,
389 	      }},						       ),
390 	CMD(  MI_UPDATE_GTT,                    SMI,   !F,  0x3F,   R  ),
391 	CMD(  MI_FLUSH_DW,                      SMI,   !F,  0x3F,   B,
392 	      .bits = {{
393 			.offset = 0,
394 			.mask = MI_FLUSH_DW_NOTIFY,
395 			.expected = 0,
396 	      },
397 	      {
398 			.offset = 1,
399 			.mask = MI_FLUSH_DW_USE_GTT,
400 			.expected = 0,
401 			.condition_offset = 0,
402 			.condition_mask = MI_FLUSH_DW_OP_MASK,
403 	      },
404 	      {
405 			.offset = 0,
406 			.mask = MI_FLUSH_DW_STORE_INDEX,
407 			.expected = 0,
408 			.condition_offset = 0,
409 			.condition_mask = MI_FLUSH_DW_OP_MASK,
410 	      }},						       ),
411 	CMD(  MI_CONDITIONAL_BATCH_BUFFER_END,  SMI,   !F,  0xFF,   B,
412 	      .bits = {{
413 			.offset = 0,
414 			.mask = MI_GLOBAL_GTT,
415 			.expected = 0,
416 	      }},						       ),
417 };
418 
419 static const struct drm_i915_cmd_descriptor gen7_blt_cmds[] = {
420 	CMD(  MI_DISPLAY_FLIP,                  SMI,   !F,  0xFF,   R  ),
421 	CMD(  MI_STORE_DWORD_IMM,               SMI,   !F,  0x3FF,  B,
422 	      .bits = {{
423 			.offset = 0,
424 			.mask = MI_GLOBAL_GTT,
425 			.expected = 0,
426 	      }},						       ),
427 	CMD(  MI_UPDATE_GTT,                    SMI,   !F,  0x3F,   R  ),
428 	CMD(  MI_FLUSH_DW,                      SMI,   !F,  0x3F,   B,
429 	      .bits = {{
430 			.offset = 0,
431 			.mask = MI_FLUSH_DW_NOTIFY,
432 			.expected = 0,
433 	      },
434 	      {
435 			.offset = 1,
436 			.mask = MI_FLUSH_DW_USE_GTT,
437 			.expected = 0,
438 			.condition_offset = 0,
439 			.condition_mask = MI_FLUSH_DW_OP_MASK,
440 	      },
441 	      {
442 			.offset = 0,
443 			.mask = MI_FLUSH_DW_STORE_INDEX,
444 			.expected = 0,
445 			.condition_offset = 0,
446 			.condition_mask = MI_FLUSH_DW_OP_MASK,
447 	      }},						       ),
448 	CMD(  COLOR_BLT,                        S2D,   !F,  0x3F,   S  ),
449 	CMD(  SRC_COPY_BLT,                     S2D,   !F,  0x3F,   S  ),
450 };
451 
452 static const struct drm_i915_cmd_descriptor hsw_blt_cmds[] = {
453 	CMD(  MI_LOAD_SCAN_LINES_INCL,          SMI,   !F,  0x3F,   R  ),
454 	CMD(  MI_LOAD_SCAN_LINES_EXCL,          SMI,   !F,  0x3F,   R  ),
455 };
456 
457 /*
458  * For Gen9 we can still rely on the h/w to enforce cmd security, and only
459  * need to re-enforce the register access checks. We therefore only need to
460  * teach the cmdparser how to find the end of each command, and identify
461  * register accesses. The table doesn't need to reject any commands, and so
462  * the only commands listed here are:
463  *   1) Those that touch registers
464  *   2) Those that do not have the default 8-bit length
465  *
466  * Note that the default MI length mask chosen for this table is 0xFF, not
467  * the 0x3F used on older devices. This is because the vast majority of MI
468  * cmds on Gen9 use a standard 8-bit Length field.
469  * All the Gen9 blitter instructions are standard 0xFF length mask, and
470  * none allow access to non-general registers, so in fact no BLT cmds are
471  * included in the table at all.
472  *
473  */
474 static const struct drm_i915_cmd_descriptor gen9_blt_cmds[] = {
475 	CMD(  MI_NOOP,                          SMI,    F,  1,      S  ),
476 	CMD(  MI_USER_INTERRUPT,                SMI,    F,  1,      S  ),
477 	CMD(  MI_WAIT_FOR_EVENT,                SMI,    F,  1,      S  ),
478 	CMD(  MI_FLUSH,                         SMI,    F,  1,      S  ),
479 	CMD(  MI_ARB_CHECK,                     SMI,    F,  1,      S  ),
480 	CMD(  MI_REPORT_HEAD,                   SMI,    F,  1,      S  ),
481 	CMD(  MI_ARB_ON_OFF,                    SMI,    F,  1,      S  ),
482 	CMD(  MI_SUSPEND_FLUSH,                 SMI,    F,  1,      S  ),
483 	CMD(  MI_LOAD_SCAN_LINES_INCL,          SMI,   !F,  0x3F,   S  ),
484 	CMD(  MI_LOAD_SCAN_LINES_EXCL,          SMI,   !F,  0x3F,   S  ),
485 	CMD(  MI_STORE_DWORD_IMM,               SMI,   !F,  0x3FF,  S  ),
486 	CMD(  MI_LOAD_REGISTER_IMM(1),          SMI,   !F,  0xFF,   W,
487 	      .reg = { .offset = 1, .mask = 0x007FFFFC, .step = 2 }    ),
488 	CMD(  MI_UPDATE_GTT,                    SMI,   !F,  0x3FF,  S  ),
489 	CMD(  MI_STORE_REGISTER_MEM_GEN8,       SMI,    F,  4,      W,
490 	      .reg = { .offset = 1, .mask = 0x007FFFFC }               ),
491 	CMD(  MI_FLUSH_DW,                      SMI,   !F,  0x3F,   S  ),
492 	CMD(  MI_LOAD_REGISTER_MEM_GEN8,        SMI,    F,  4,      W,
493 	      .reg = { .offset = 1, .mask = 0x007FFFFC }               ),
494 	CMD(  MI_LOAD_REGISTER_REG,             SMI,    !F,  0xFF,  W,
495 	      .reg = { .offset = 1, .mask = 0x007FFFFC, .step = 1 }    ),
496 
497 	/*
498 	 * We allow BB_START but apply further checks. We just sanitize the
499 	 * basic fields here.
500 	 */
501 #define MI_BB_START_OPERAND_MASK   GENMASK(SMI-1, 0)
502 #define MI_BB_START_OPERAND_EXPECT (MI_BATCH_PPGTT_HSW | 1)
503 	CMD(  MI_BATCH_BUFFER_START_GEN8,       SMI,    !F,  0xFF,  B,
504 	      .bits = {{
505 			.offset = 0,
506 			.mask = MI_BB_START_OPERAND_MASK,
507 			.expected = MI_BB_START_OPERAND_EXPECT,
508 	      }},						       ),
509 };
510 
511 static const struct drm_i915_cmd_descriptor noop_desc =
512 	CMD(MI_NOOP, SMI, F, 1, S);
513 
514 #undef CMD
515 #undef SMI
516 #undef S3D
517 #undef S2D
518 #undef SMFX
519 #undef F
520 #undef S
521 #undef R
522 #undef W
523 #undef B
524 
525 static const struct drm_i915_cmd_table gen7_render_cmd_table[] = {
526 	{ gen7_common_cmds, ARRAY_SIZE(gen7_common_cmds) },
527 	{ gen7_render_cmds, ARRAY_SIZE(gen7_render_cmds) },
528 };
529 
530 static const struct drm_i915_cmd_table hsw_render_ring_cmd_table[] = {
531 	{ gen7_common_cmds, ARRAY_SIZE(gen7_common_cmds) },
532 	{ gen7_render_cmds, ARRAY_SIZE(gen7_render_cmds) },
533 	{ hsw_render_cmds, ARRAY_SIZE(hsw_render_cmds) },
534 };
535 
536 static const struct drm_i915_cmd_table gen7_video_cmd_table[] = {
537 	{ gen7_common_cmds, ARRAY_SIZE(gen7_common_cmds) },
538 	{ gen7_video_cmds, ARRAY_SIZE(gen7_video_cmds) },
539 };
540 
541 static const struct drm_i915_cmd_table hsw_vebox_cmd_table[] = {
542 	{ gen7_common_cmds, ARRAY_SIZE(gen7_common_cmds) },
543 	{ gen7_vecs_cmds, ARRAY_SIZE(gen7_vecs_cmds) },
544 };
545 
546 static const struct drm_i915_cmd_table gen7_blt_cmd_table[] = {
547 	{ gen7_common_cmds, ARRAY_SIZE(gen7_common_cmds) },
548 	{ gen7_blt_cmds, ARRAY_SIZE(gen7_blt_cmds) },
549 };
550 
551 static const struct drm_i915_cmd_table hsw_blt_ring_cmd_table[] = {
552 	{ gen7_common_cmds, ARRAY_SIZE(gen7_common_cmds) },
553 	{ gen7_blt_cmds, ARRAY_SIZE(gen7_blt_cmds) },
554 	{ hsw_blt_cmds, ARRAY_SIZE(hsw_blt_cmds) },
555 };
556 
557 static const struct drm_i915_cmd_table gen9_blt_cmd_table[] = {
558 	{ gen9_blt_cmds, ARRAY_SIZE(gen9_blt_cmds) },
559 };
560 
561 
562 /*
563  * Register whitelists, sorted by increasing register offset.
564  */
565 
566 /*
567  * An individual whitelist entry granting access to register addr.  If
568  * mask is non-zero the argument of immediate register writes will be
569  * AND-ed with mask, and the command will be rejected if the result
570  * doesn't match value.
571  *
572  * Registers with non-zero mask are only allowed to be written using
573  * LRI.
574  */
575 struct drm_i915_reg_descriptor {
576 	i915_reg_t addr;
577 	u32 mask;
578 	u32 value;
579 };
580 
581 /* Convenience macro for adding 32-bit registers. */
582 #define REG32(_reg, ...) \
583 	{ .addr = (_reg), __VA_ARGS__ }
584 
585 #define REG32_IDX(_reg, idx) \
586 	{ .addr = _reg(idx) }
587 
588 /*
589  * Convenience macro for adding 64-bit registers.
590  *
591  * Some registers that userspace accesses are 64 bits. The register
592  * access commands only allow 32-bit accesses. Hence, we have to include
593  * entries for both halves of the 64-bit registers.
594  */
595 #define REG64(_reg) \
596 	{ .addr = _reg }, \
597 	{ .addr = _reg ## _UDW }
598 
599 #define REG64_IDX(_reg, idx) \
600 	{ .addr = _reg(idx) }, \
601 	{ .addr = _reg ## _UDW(idx) }
602 
603 #define REG64_BASE_IDX(_reg, base, idx) \
604 	{ .addr = _reg(base, idx) }, \
605 	{ .addr = _reg ## _UDW(base, idx) }
606 
607 static const struct drm_i915_reg_descriptor gen7_render_regs[] = {
608 	REG64(GPGPU_THREADS_DISPATCHED),
609 	REG64(HS_INVOCATION_COUNT),
610 	REG64(DS_INVOCATION_COUNT),
611 	REG64(IA_VERTICES_COUNT),
612 	REG64(IA_PRIMITIVES_COUNT),
613 	REG64(VS_INVOCATION_COUNT),
614 	REG64(GS_INVOCATION_COUNT),
615 	REG64(GS_PRIMITIVES_COUNT),
616 	REG64(CL_INVOCATION_COUNT),
617 	REG64(CL_PRIMITIVES_COUNT),
618 	REG64(PS_INVOCATION_COUNT),
619 	REG64(PS_DEPTH_COUNT),
620 	REG64_IDX(RING_TIMESTAMP, RENDER_RING_BASE),
621 	REG64_IDX(MI_PREDICATE_SRC0, RENDER_RING_BASE),
622 	REG64_IDX(MI_PREDICATE_SRC1, RENDER_RING_BASE),
623 	REG32(GEN7_3DPRIM_END_OFFSET),
624 	REG32(GEN7_3DPRIM_START_VERTEX),
625 	REG32(GEN7_3DPRIM_VERTEX_COUNT),
626 	REG32(GEN7_3DPRIM_INSTANCE_COUNT),
627 	REG32(GEN7_3DPRIM_START_INSTANCE),
628 	REG32(GEN7_3DPRIM_BASE_VERTEX),
629 	REG32(GEN7_GPGPU_DISPATCHDIMX),
630 	REG32(GEN7_GPGPU_DISPATCHDIMY),
631 	REG32(GEN7_GPGPU_DISPATCHDIMZ),
632 	REG64_IDX(RING_TIMESTAMP, BSD_RING_BASE),
633 	REG64_IDX(GEN7_SO_NUM_PRIMS_WRITTEN, 0),
634 	REG64_IDX(GEN7_SO_NUM_PRIMS_WRITTEN, 1),
635 	REG64_IDX(GEN7_SO_NUM_PRIMS_WRITTEN, 2),
636 	REG64_IDX(GEN7_SO_NUM_PRIMS_WRITTEN, 3),
637 	REG64_IDX(GEN7_SO_PRIM_STORAGE_NEEDED, 0),
638 	REG64_IDX(GEN7_SO_PRIM_STORAGE_NEEDED, 1),
639 	REG64_IDX(GEN7_SO_PRIM_STORAGE_NEEDED, 2),
640 	REG64_IDX(GEN7_SO_PRIM_STORAGE_NEEDED, 3),
641 	REG32(GEN7_SO_WRITE_OFFSET(0)),
642 	REG32(GEN7_SO_WRITE_OFFSET(1)),
643 	REG32(GEN7_SO_WRITE_OFFSET(2)),
644 	REG32(GEN7_SO_WRITE_OFFSET(3)),
645 	REG32(GEN7_L3SQCREG1),
646 	REG32(GEN7_L3CNTLREG2),
647 	REG32(GEN7_L3CNTLREG3),
648 	REG64_IDX(RING_TIMESTAMP, BLT_RING_BASE),
649 };
650 
651 static const struct drm_i915_reg_descriptor hsw_render_regs[] = {
652 	REG64_BASE_IDX(GEN8_RING_CS_GPR, RENDER_RING_BASE, 0),
653 	REG64_BASE_IDX(GEN8_RING_CS_GPR, RENDER_RING_BASE, 1),
654 	REG64_BASE_IDX(GEN8_RING_CS_GPR, RENDER_RING_BASE, 2),
655 	REG64_BASE_IDX(GEN8_RING_CS_GPR, RENDER_RING_BASE, 3),
656 	REG64_BASE_IDX(GEN8_RING_CS_GPR, RENDER_RING_BASE, 4),
657 	REG64_BASE_IDX(GEN8_RING_CS_GPR, RENDER_RING_BASE, 5),
658 	REG64_BASE_IDX(GEN8_RING_CS_GPR, RENDER_RING_BASE, 6),
659 	REG64_BASE_IDX(GEN8_RING_CS_GPR, RENDER_RING_BASE, 7),
660 	REG64_BASE_IDX(GEN8_RING_CS_GPR, RENDER_RING_BASE, 8),
661 	REG64_BASE_IDX(GEN8_RING_CS_GPR, RENDER_RING_BASE, 9),
662 	REG64_BASE_IDX(GEN8_RING_CS_GPR, RENDER_RING_BASE, 10),
663 	REG64_BASE_IDX(GEN8_RING_CS_GPR, RENDER_RING_BASE, 11),
664 	REG64_BASE_IDX(GEN8_RING_CS_GPR, RENDER_RING_BASE, 12),
665 	REG64_BASE_IDX(GEN8_RING_CS_GPR, RENDER_RING_BASE, 13),
666 	REG64_BASE_IDX(GEN8_RING_CS_GPR, RENDER_RING_BASE, 14),
667 	REG64_BASE_IDX(GEN8_RING_CS_GPR, RENDER_RING_BASE, 15),
668 	REG32(HSW_SCRATCH1,
669 	      .mask = ~HSW_SCRATCH1_L3_DATA_ATOMICS_DISABLE,
670 	      .value = 0),
671 	REG32(HSW_ROW_CHICKEN3,
672 	      .mask = ~(HSW_ROW_CHICKEN3_L3_GLOBAL_ATOMICS_DISABLE << 16 |
673                         HSW_ROW_CHICKEN3_L3_GLOBAL_ATOMICS_DISABLE),
674 	      .value = 0),
675 };
676 
677 static const struct drm_i915_reg_descriptor gen7_blt_regs[] = {
678 	REG64_IDX(RING_TIMESTAMP, RENDER_RING_BASE),
679 	REG64_IDX(RING_TIMESTAMP, BSD_RING_BASE),
680 	REG32(BCS_SWCTRL),
681 	REG64_IDX(RING_TIMESTAMP, BLT_RING_BASE),
682 };
683 
684 static const struct drm_i915_reg_descriptor gen9_blt_regs[] = {
685 	REG64_IDX(RING_TIMESTAMP, RENDER_RING_BASE),
686 	REG64_IDX(RING_TIMESTAMP, BSD_RING_BASE),
687 	REG32(BCS_SWCTRL),
688 	REG64_IDX(RING_TIMESTAMP, BLT_RING_BASE),
689 	REG32_IDX(RING_CTX_TIMESTAMP, BLT_RING_BASE),
690 	REG64_BASE_IDX(GEN8_RING_CS_GPR, BLT_RING_BASE, 0),
691 	REG64_BASE_IDX(GEN8_RING_CS_GPR, BLT_RING_BASE, 1),
692 	REG64_BASE_IDX(GEN8_RING_CS_GPR, BLT_RING_BASE, 2),
693 	REG64_BASE_IDX(GEN8_RING_CS_GPR, BLT_RING_BASE, 3),
694 	REG64_BASE_IDX(GEN8_RING_CS_GPR, BLT_RING_BASE, 4),
695 	REG64_BASE_IDX(GEN8_RING_CS_GPR, BLT_RING_BASE, 5),
696 	REG64_BASE_IDX(GEN8_RING_CS_GPR, BLT_RING_BASE, 6),
697 	REG64_BASE_IDX(GEN8_RING_CS_GPR, BLT_RING_BASE, 7),
698 	REG64_BASE_IDX(GEN8_RING_CS_GPR, BLT_RING_BASE, 8),
699 	REG64_BASE_IDX(GEN8_RING_CS_GPR, BLT_RING_BASE, 9),
700 	REG64_BASE_IDX(GEN8_RING_CS_GPR, BLT_RING_BASE, 10),
701 	REG64_BASE_IDX(GEN8_RING_CS_GPR, BLT_RING_BASE, 11),
702 	REG64_BASE_IDX(GEN8_RING_CS_GPR, BLT_RING_BASE, 12),
703 	REG64_BASE_IDX(GEN8_RING_CS_GPR, BLT_RING_BASE, 13),
704 	REG64_BASE_IDX(GEN8_RING_CS_GPR, BLT_RING_BASE, 14),
705 	REG64_BASE_IDX(GEN8_RING_CS_GPR, BLT_RING_BASE, 15),
706 };
707 
708 #undef REG64
709 #undef REG32
710 
711 struct drm_i915_reg_table {
712 	const struct drm_i915_reg_descriptor *regs;
713 	int num_regs;
714 };
715 
716 static const struct drm_i915_reg_table ivb_render_reg_tables[] = {
717 	{ gen7_render_regs, ARRAY_SIZE(gen7_render_regs) },
718 };
719 
720 static const struct drm_i915_reg_table ivb_blt_reg_tables[] = {
721 	{ gen7_blt_regs, ARRAY_SIZE(gen7_blt_regs) },
722 };
723 
724 static const struct drm_i915_reg_table hsw_render_reg_tables[] = {
725 	{ gen7_render_regs, ARRAY_SIZE(gen7_render_regs) },
726 	{ hsw_render_regs, ARRAY_SIZE(hsw_render_regs) },
727 };
728 
729 static const struct drm_i915_reg_table hsw_blt_reg_tables[] = {
730 	{ gen7_blt_regs, ARRAY_SIZE(gen7_blt_regs) },
731 };
732 
733 static const struct drm_i915_reg_table gen9_blt_reg_tables[] = {
734 	{ gen9_blt_regs, ARRAY_SIZE(gen9_blt_regs) },
735 };
736 
737 static u32 gen7_render_get_cmd_length_mask(u32 cmd_header)
738 {
739 	u32 client = cmd_header >> INSTR_CLIENT_SHIFT;
740 	u32 subclient =
741 		(cmd_header & INSTR_SUBCLIENT_MASK) >> INSTR_SUBCLIENT_SHIFT;
742 
743 	if (client == INSTR_MI_CLIENT)
744 		return 0x3F;
745 	else if (client == INSTR_RC_CLIENT) {
746 		if (subclient == INSTR_MEDIA_SUBCLIENT)
747 			return 0xFFFF;
748 		else
749 			return 0xFF;
750 	}
751 
752 	DRM_DEBUG("CMD: Abnormal rcs cmd length! 0x%08X\n", cmd_header);
753 	return 0;
754 }
755 
756 static u32 gen7_bsd_get_cmd_length_mask(u32 cmd_header)
757 {
758 	u32 client = cmd_header >> INSTR_CLIENT_SHIFT;
759 	u32 subclient =
760 		(cmd_header & INSTR_SUBCLIENT_MASK) >> INSTR_SUBCLIENT_SHIFT;
761 	u32 op = (cmd_header & INSTR_26_TO_24_MASK) >> INSTR_26_TO_24_SHIFT;
762 
763 	if (client == INSTR_MI_CLIENT)
764 		return 0x3F;
765 	else if (client == INSTR_RC_CLIENT) {
766 		if (subclient == INSTR_MEDIA_SUBCLIENT) {
767 			if (op == 6)
768 				return 0xFFFF;
769 			else
770 				return 0xFFF;
771 		} else
772 			return 0xFF;
773 	}
774 
775 	DRM_DEBUG("CMD: Abnormal bsd cmd length! 0x%08X\n", cmd_header);
776 	return 0;
777 }
778 
779 static u32 gen7_blt_get_cmd_length_mask(u32 cmd_header)
780 {
781 	u32 client = cmd_header >> INSTR_CLIENT_SHIFT;
782 
783 	if (client == INSTR_MI_CLIENT)
784 		return 0x3F;
785 	else if (client == INSTR_BC_CLIENT)
786 		return 0xFF;
787 
788 	DRM_DEBUG("CMD: Abnormal blt cmd length! 0x%08X\n", cmd_header);
789 	return 0;
790 }
791 
792 static u32 gen9_blt_get_cmd_length_mask(u32 cmd_header)
793 {
794 	u32 client = cmd_header >> INSTR_CLIENT_SHIFT;
795 
796 	if (client == INSTR_MI_CLIENT || client == INSTR_BC_CLIENT)
797 		return 0xFF;
798 
799 	DRM_DEBUG("CMD: Abnormal blt cmd length! 0x%08X\n", cmd_header);
800 	return 0;
801 }
802 
803 static bool validate_cmds_sorted(const struct intel_engine_cs *engine,
804 				 const struct drm_i915_cmd_table *cmd_tables,
805 				 int cmd_table_count)
806 {
807 	int i;
808 	bool ret = true;
809 
810 	if (!cmd_tables || cmd_table_count == 0)
811 		return true;
812 
813 	for (i = 0; i < cmd_table_count; i++) {
814 		const struct drm_i915_cmd_table *table = &cmd_tables[i];
815 		u32 previous = 0;
816 		int j;
817 
818 		for (j = 0; j < table->count; j++) {
819 			const struct drm_i915_cmd_descriptor *desc =
820 				&table->table[j];
821 			u32 curr = desc->cmd.value & desc->cmd.mask;
822 
823 			if (curr < previous) {
824 				drm_err(&engine->i915->drm,
825 					"CMD: %s [%d] command table not sorted: "
826 					"table=%d entry=%d cmd=0x%08X prev=0x%08X\n",
827 					engine->name, engine->id,
828 					i, j, curr, previous);
829 				ret = false;
830 			}
831 
832 			previous = curr;
833 		}
834 	}
835 
836 	return ret;
837 }
838 
839 static bool check_sorted(const struct intel_engine_cs *engine,
840 			 const struct drm_i915_reg_descriptor *reg_table,
841 			 int reg_count)
842 {
843 	int i;
844 	u32 previous = 0;
845 	bool ret = true;
846 
847 	for (i = 0; i < reg_count; i++) {
848 		u32 curr = i915_mmio_reg_offset(reg_table[i].addr);
849 
850 		if (curr < previous) {
851 			drm_err(&engine->i915->drm,
852 				"CMD: %s [%d] register table not sorted: "
853 				"entry=%d reg=0x%08X prev=0x%08X\n",
854 				engine->name, engine->id,
855 				i, curr, previous);
856 			ret = false;
857 		}
858 
859 		previous = curr;
860 	}
861 
862 	return ret;
863 }
864 
865 static bool validate_regs_sorted(struct intel_engine_cs *engine)
866 {
867 	int i;
868 	const struct drm_i915_reg_table *table;
869 
870 	for (i = 0; i < engine->reg_table_count; i++) {
871 		table = &engine->reg_tables[i];
872 		if (!check_sorted(engine, table->regs, table->num_regs))
873 			return false;
874 	}
875 
876 	return true;
877 }
878 
879 struct cmd_node {
880 	const struct drm_i915_cmd_descriptor *desc;
881 	struct hlist_node node;
882 };
883 
884 /*
885  * Different command ranges have different numbers of bits for the opcode. For
886  * example, MI commands use bits 31:23 while 3D commands use bits 31:16. The
887  * problem is that, for example, MI commands use bits 22:16 for other fields
888  * such as GGTT vs PPGTT bits. If we include those bits in the mask then when
889  * we mask a command from a batch it could hash to the wrong bucket due to
890  * non-opcode bits being set. But if we don't include those bits, some 3D
891  * commands may hash to the same bucket due to not including opcode bits that
892  * make the command unique. For now, we will risk hashing to the same bucket.
893  */
894 static inline u32 cmd_header_key(u32 x)
895 {
896 	switch (x >> INSTR_CLIENT_SHIFT) {
897 	default:
898 	case INSTR_MI_CLIENT:
899 		return x >> STD_MI_OPCODE_SHIFT;
900 	case INSTR_RC_CLIENT:
901 		return x >> STD_3D_OPCODE_SHIFT;
902 	case INSTR_BC_CLIENT:
903 		return x >> STD_2D_OPCODE_SHIFT;
904 	}
905 }
906 
907 static int init_hash_table(struct intel_engine_cs *engine,
908 			   const struct drm_i915_cmd_table *cmd_tables,
909 			   int cmd_table_count)
910 {
911 	int i, j;
912 
913 	hash_init(engine->cmd_hash);
914 
915 	for (i = 0; i < cmd_table_count; i++) {
916 		const struct drm_i915_cmd_table *table = &cmd_tables[i];
917 
918 		for (j = 0; j < table->count; j++) {
919 			const struct drm_i915_cmd_descriptor *desc =
920 				&table->table[j];
921 			struct cmd_node *desc_node =
922 				kmalloc(sizeof(*desc_node), GFP_KERNEL);
923 
924 			if (!desc_node)
925 				return -ENOMEM;
926 
927 			desc_node->desc = desc;
928 			hash_add(engine->cmd_hash, &desc_node->node,
929 				 cmd_header_key(desc->cmd.value));
930 		}
931 	}
932 
933 	return 0;
934 }
935 
936 static void fini_hash_table(struct intel_engine_cs *engine)
937 {
938 	struct hlist_node *tmp;
939 	struct cmd_node *desc_node;
940 	int i;
941 
942 	hash_for_each_safe(engine->cmd_hash, i, tmp, desc_node, node) {
943 		hash_del(&desc_node->node);
944 		kfree(desc_node);
945 	}
946 }
947 
948 /**
949  * intel_engine_init_cmd_parser() - set cmd parser related fields for an engine
950  * @engine: the engine to initialize
951  *
952  * Optionally initializes fields related to batch buffer command parsing in the
953  * struct intel_engine_cs based on whether the platform requires software
954  * command parsing.
955  */
956 int intel_engine_init_cmd_parser(struct intel_engine_cs *engine)
957 {
958 	const struct drm_i915_cmd_table *cmd_tables;
959 	int cmd_table_count;
960 	int ret;
961 
962 	if (GRAPHICS_VER(engine->i915) != 7 && !(GRAPHICS_VER(engine->i915) == 9 &&
963 						 engine->class == COPY_ENGINE_CLASS))
964 		return 0;
965 
966 	switch (engine->class) {
967 	case RENDER_CLASS:
968 		if (IS_HASWELL(engine->i915)) {
969 			cmd_tables = hsw_render_ring_cmd_table;
970 			cmd_table_count =
971 				ARRAY_SIZE(hsw_render_ring_cmd_table);
972 		} else {
973 			cmd_tables = gen7_render_cmd_table;
974 			cmd_table_count = ARRAY_SIZE(gen7_render_cmd_table);
975 		}
976 
977 		if (IS_HASWELL(engine->i915)) {
978 			engine->reg_tables = hsw_render_reg_tables;
979 			engine->reg_table_count = ARRAY_SIZE(hsw_render_reg_tables);
980 		} else {
981 			engine->reg_tables = ivb_render_reg_tables;
982 			engine->reg_table_count = ARRAY_SIZE(ivb_render_reg_tables);
983 		}
984 		engine->get_cmd_length_mask = gen7_render_get_cmd_length_mask;
985 		break;
986 	case VIDEO_DECODE_CLASS:
987 		cmd_tables = gen7_video_cmd_table;
988 		cmd_table_count = ARRAY_SIZE(gen7_video_cmd_table);
989 		engine->get_cmd_length_mask = gen7_bsd_get_cmd_length_mask;
990 		break;
991 	case COPY_ENGINE_CLASS:
992 		engine->get_cmd_length_mask = gen7_blt_get_cmd_length_mask;
993 		if (GRAPHICS_VER(engine->i915) == 9) {
994 			cmd_tables = gen9_blt_cmd_table;
995 			cmd_table_count = ARRAY_SIZE(gen9_blt_cmd_table);
996 			engine->get_cmd_length_mask =
997 				gen9_blt_get_cmd_length_mask;
998 
999 			/* BCS Engine unsafe without parser */
1000 			engine->flags |= I915_ENGINE_REQUIRES_CMD_PARSER;
1001 		} else if (IS_HASWELL(engine->i915)) {
1002 			cmd_tables = hsw_blt_ring_cmd_table;
1003 			cmd_table_count = ARRAY_SIZE(hsw_blt_ring_cmd_table);
1004 		} else {
1005 			cmd_tables = gen7_blt_cmd_table;
1006 			cmd_table_count = ARRAY_SIZE(gen7_blt_cmd_table);
1007 		}
1008 
1009 		if (GRAPHICS_VER(engine->i915) == 9) {
1010 			engine->reg_tables = gen9_blt_reg_tables;
1011 			engine->reg_table_count =
1012 				ARRAY_SIZE(gen9_blt_reg_tables);
1013 		} else if (IS_HASWELL(engine->i915)) {
1014 			engine->reg_tables = hsw_blt_reg_tables;
1015 			engine->reg_table_count = ARRAY_SIZE(hsw_blt_reg_tables);
1016 		} else {
1017 			engine->reg_tables = ivb_blt_reg_tables;
1018 			engine->reg_table_count = ARRAY_SIZE(ivb_blt_reg_tables);
1019 		}
1020 		break;
1021 	case VIDEO_ENHANCEMENT_CLASS:
1022 		cmd_tables = hsw_vebox_cmd_table;
1023 		cmd_table_count = ARRAY_SIZE(hsw_vebox_cmd_table);
1024 		/* VECS can use the same length_mask function as VCS */
1025 		engine->get_cmd_length_mask = gen7_bsd_get_cmd_length_mask;
1026 		break;
1027 	default:
1028 		MISSING_CASE(engine->class);
1029 		goto out;
1030 	}
1031 
1032 	if (!validate_cmds_sorted(engine, cmd_tables, cmd_table_count)) {
1033 		drm_err(&engine->i915->drm,
1034 			"%s: command descriptions are not sorted\n",
1035 			engine->name);
1036 		goto out;
1037 	}
1038 	if (!validate_regs_sorted(engine)) {
1039 		drm_err(&engine->i915->drm,
1040 			"%s: registers are not sorted\n", engine->name);
1041 		goto out;
1042 	}
1043 
1044 	ret = init_hash_table(engine, cmd_tables, cmd_table_count);
1045 	if (ret) {
1046 		drm_err(&engine->i915->drm,
1047 			"%s: initialised failed!\n", engine->name);
1048 		fini_hash_table(engine);
1049 		goto out;
1050 	}
1051 
1052 	engine->flags |= I915_ENGINE_USING_CMD_PARSER;
1053 
1054 out:
1055 	if (intel_engine_requires_cmd_parser(engine) &&
1056 	    !intel_engine_using_cmd_parser(engine))
1057 		return -EINVAL;
1058 
1059 	return 0;
1060 }
1061 
1062 /**
1063  * intel_engine_cleanup_cmd_parser() - clean up cmd parser related fields
1064  * @engine: the engine to clean up
1065  *
1066  * Releases any resources related to command parsing that may have been
1067  * initialized for the specified engine.
1068  */
1069 void intel_engine_cleanup_cmd_parser(struct intel_engine_cs *engine)
1070 {
1071 	if (!intel_engine_using_cmd_parser(engine))
1072 		return;
1073 
1074 	fini_hash_table(engine);
1075 }
1076 
1077 static const struct drm_i915_cmd_descriptor*
1078 find_cmd_in_table(struct intel_engine_cs *engine,
1079 		  u32 cmd_header)
1080 {
1081 	struct cmd_node *desc_node;
1082 
1083 	hash_for_each_possible(engine->cmd_hash, desc_node, node,
1084 			       cmd_header_key(cmd_header)) {
1085 		const struct drm_i915_cmd_descriptor *desc = desc_node->desc;
1086 		if (((cmd_header ^ desc->cmd.value) & desc->cmd.mask) == 0)
1087 			return desc;
1088 	}
1089 
1090 	return NULL;
1091 }
1092 
1093 /*
1094  * Returns a pointer to a descriptor for the command specified by cmd_header.
1095  *
1096  * The caller must supply space for a default descriptor via the default_desc
1097  * parameter. If no descriptor for the specified command exists in the engine's
1098  * command parser tables, this function fills in default_desc based on the
1099  * engine's default length encoding and returns default_desc.
1100  */
1101 static const struct drm_i915_cmd_descriptor*
1102 find_cmd(struct intel_engine_cs *engine,
1103 	 u32 cmd_header,
1104 	 const struct drm_i915_cmd_descriptor *desc,
1105 	 struct drm_i915_cmd_descriptor *default_desc)
1106 {
1107 	u32 mask;
1108 
1109 	if (((cmd_header ^ desc->cmd.value) & desc->cmd.mask) == 0)
1110 		return desc;
1111 
1112 	desc = find_cmd_in_table(engine, cmd_header);
1113 	if (desc)
1114 		return desc;
1115 
1116 	mask = engine->get_cmd_length_mask(cmd_header);
1117 	if (!mask)
1118 		return NULL;
1119 
1120 	default_desc->cmd.value = cmd_header;
1121 	default_desc->cmd.mask = ~0u << MIN_OPCODE_SHIFT;
1122 	default_desc->length.mask = mask;
1123 	default_desc->flags = CMD_DESC_SKIP;
1124 	return default_desc;
1125 }
1126 
1127 static const struct drm_i915_reg_descriptor *
1128 __find_reg(const struct drm_i915_reg_descriptor *table, int count, u32 addr)
1129 {
1130 	int start = 0, end = count;
1131 	while (start < end) {
1132 		int mid = start + (end - start) / 2;
1133 		int ret = addr - i915_mmio_reg_offset(table[mid].addr);
1134 		if (ret < 0)
1135 			end = mid;
1136 		else if (ret > 0)
1137 			start = mid + 1;
1138 		else
1139 			return &table[mid];
1140 	}
1141 	return NULL;
1142 }
1143 
1144 static const struct drm_i915_reg_descriptor *
1145 find_reg(const struct intel_engine_cs *engine, u32 addr)
1146 {
1147 	const struct drm_i915_reg_table *table = engine->reg_tables;
1148 	const struct drm_i915_reg_descriptor *reg = NULL;
1149 	int count = engine->reg_table_count;
1150 
1151 	for (; !reg && (count > 0); ++table, --count)
1152 		reg = __find_reg(table->regs, table->num_regs, addr);
1153 
1154 	return reg;
1155 }
1156 
1157 /* Returns a vmap'd pointer to dst_obj, which the caller must unmap */
1158 static u32 *copy_batch(struct drm_i915_gem_object *dst_obj,
1159 		       struct drm_i915_gem_object *src_obj,
1160 		       unsigned long offset, unsigned long length,
1161 		       bool *needs_clflush_after)
1162 {
1163 	unsigned int src_needs_clflush;
1164 	unsigned int dst_needs_clflush;
1165 	void *dst, *src;
1166 	int ret;
1167 
1168 	ret = i915_gem_object_prepare_write(dst_obj, &dst_needs_clflush);
1169 	if (ret)
1170 		return ERR_PTR(ret);
1171 
1172 	dst = i915_gem_object_pin_map(dst_obj, I915_MAP_WB);
1173 	i915_gem_object_finish_access(dst_obj);
1174 	if (IS_ERR(dst))
1175 		return dst;
1176 
1177 	ret = i915_gem_object_prepare_read(src_obj, &src_needs_clflush);
1178 	if (ret) {
1179 		i915_gem_object_unpin_map(dst_obj);
1180 		return ERR_PTR(ret);
1181 	}
1182 
1183 	src = ERR_PTR(-ENODEV);
1184 	if (src_needs_clflush && i915_has_memcpy_from_wc()) {
1185 		src = i915_gem_object_pin_map(src_obj, I915_MAP_WC);
1186 		if (!IS_ERR(src)) {
1187 			i915_unaligned_memcpy_from_wc(dst,
1188 						      src + offset,
1189 						      length);
1190 			i915_gem_object_unpin_map(src_obj);
1191 		}
1192 	}
1193 	if (IS_ERR(src)) {
1194 		unsigned long x, n, remain;
1195 		void *ptr;
1196 
1197 		/*
1198 		 * We can avoid clflushing partial cachelines before the write
1199 		 * if we only every write full cache-lines. Since we know that
1200 		 * both the source and destination are in multiples of
1201 		 * PAGE_SIZE, we can simply round up to the next cacheline.
1202 		 * We don't care about copying too much here as we only
1203 		 * validate up to the end of the batch.
1204 		 */
1205 		remain = length;
1206 		if (dst_needs_clflush & CLFLUSH_BEFORE)
1207 			remain = round_up(remain,
1208 					  boot_cpu_data.x86_clflush_size);
1209 
1210 		ptr = dst;
1211 		x = offset_in_page(offset);
1212 		for (n = offset >> PAGE_SHIFT; remain; n++) {
1213 			int len = min(remain, PAGE_SIZE - x);
1214 
1215 			src = kmap_local_page(i915_gem_object_get_page(src_obj, n));
1216 			if (src_needs_clflush)
1217 				drm_clflush_virt_range(src + x, len);
1218 			memcpy(ptr, src + x, len);
1219 			kunmap_local(src);
1220 
1221 			ptr += len;
1222 			remain -= len;
1223 			x = 0;
1224 		}
1225 	}
1226 
1227 	i915_gem_object_finish_access(src_obj);
1228 
1229 	memset32(dst + length, 0, (dst_obj->base.size - length) / sizeof(u32));
1230 
1231 	/* dst_obj is returned with vmap pinned */
1232 	*needs_clflush_after = dst_needs_clflush & CLFLUSH_AFTER;
1233 
1234 	return dst;
1235 }
1236 
1237 static inline bool cmd_desc_is(const struct drm_i915_cmd_descriptor * const desc,
1238 			       const u32 cmd)
1239 {
1240 	return desc->cmd.value == (cmd & desc->cmd.mask);
1241 }
1242 
1243 static bool check_cmd(const struct intel_engine_cs *engine,
1244 		      const struct drm_i915_cmd_descriptor *desc,
1245 		      const u32 *cmd, u32 length)
1246 {
1247 	if (desc->flags & CMD_DESC_SKIP)
1248 		return true;
1249 
1250 	if (desc->flags & CMD_DESC_REJECT) {
1251 		DRM_DEBUG("CMD: Rejected command: 0x%08X\n", *cmd);
1252 		return false;
1253 	}
1254 
1255 	if (desc->flags & CMD_DESC_REGISTER) {
1256 		/*
1257 		 * Get the distance between individual register offset
1258 		 * fields if the command can perform more than one
1259 		 * access at a time.
1260 		 */
1261 		const u32 step = desc->reg.step ? desc->reg.step : length;
1262 		u32 offset;
1263 
1264 		for (offset = desc->reg.offset; offset < length;
1265 		     offset += step) {
1266 			const u32 reg_addr = cmd[offset] & desc->reg.mask;
1267 			const struct drm_i915_reg_descriptor *reg =
1268 				find_reg(engine, reg_addr);
1269 
1270 			if (!reg) {
1271 				DRM_DEBUG("CMD: Rejected register 0x%08X in command: 0x%08X (%s)\n",
1272 					  reg_addr, *cmd, engine->name);
1273 				return false;
1274 			}
1275 
1276 			/*
1277 			 * Check the value written to the register against the
1278 			 * allowed mask/value pair given in the whitelist entry.
1279 			 */
1280 			if (reg->mask) {
1281 				if (cmd_desc_is(desc, MI_LOAD_REGISTER_MEM)) {
1282 					DRM_DEBUG("CMD: Rejected LRM to masked register 0x%08X\n",
1283 						  reg_addr);
1284 					return false;
1285 				}
1286 
1287 				if (cmd_desc_is(desc, MI_LOAD_REGISTER_REG)) {
1288 					DRM_DEBUG("CMD: Rejected LRR to masked register 0x%08X\n",
1289 						  reg_addr);
1290 					return false;
1291 				}
1292 
1293 				if (cmd_desc_is(desc, MI_LOAD_REGISTER_IMM(1)) &&
1294 				    (offset + 2 > length ||
1295 				     (cmd[offset + 1] & reg->mask) != reg->value)) {
1296 					DRM_DEBUG("CMD: Rejected LRI to masked register 0x%08X\n",
1297 						  reg_addr);
1298 					return false;
1299 				}
1300 			}
1301 		}
1302 	}
1303 
1304 	if (desc->flags & CMD_DESC_BITMASK) {
1305 		int i;
1306 
1307 		for (i = 0; i < MAX_CMD_DESC_BITMASKS; i++) {
1308 			u32 dword;
1309 
1310 			if (desc->bits[i].mask == 0)
1311 				break;
1312 
1313 			if (desc->bits[i].condition_mask != 0) {
1314 				u32 offset =
1315 					desc->bits[i].condition_offset;
1316 				u32 condition = cmd[offset] &
1317 					desc->bits[i].condition_mask;
1318 
1319 				if (condition == 0)
1320 					continue;
1321 			}
1322 
1323 			if (desc->bits[i].offset >= length) {
1324 				DRM_DEBUG("CMD: Rejected command 0x%08X, too short to check bitmask (%s)\n",
1325 					  *cmd, engine->name);
1326 				return false;
1327 			}
1328 
1329 			dword = cmd[desc->bits[i].offset] &
1330 				desc->bits[i].mask;
1331 
1332 			if (dword != desc->bits[i].expected) {
1333 				DRM_DEBUG("CMD: Rejected command 0x%08X for bitmask 0x%08X (exp=0x%08X act=0x%08X) (%s)\n",
1334 					  *cmd,
1335 					  desc->bits[i].mask,
1336 					  desc->bits[i].expected,
1337 					  dword, engine->name);
1338 				return false;
1339 			}
1340 		}
1341 	}
1342 
1343 	return true;
1344 }
1345 
1346 static int check_bbstart(u32 *cmd, u32 offset, u32 length,
1347 			 u32 batch_length,
1348 			 u64 batch_addr,
1349 			 u64 shadow_addr,
1350 			 const unsigned long *jump_whitelist)
1351 {
1352 	u64 jump_offset, jump_target;
1353 	u32 target_cmd_offset, target_cmd_index;
1354 
1355 	/* For igt compatibility on older platforms */
1356 	if (!jump_whitelist) {
1357 		DRM_DEBUG("CMD: Rejecting BB_START for ggtt based submission\n");
1358 		return -EACCES;
1359 	}
1360 
1361 	if (length != 3) {
1362 		DRM_DEBUG("CMD: Recursive BB_START with bad length(%u)\n",
1363 			  length);
1364 		return -EINVAL;
1365 	}
1366 
1367 	jump_target = *(u64 *)(cmd + 1);
1368 	jump_offset = jump_target - batch_addr;
1369 
1370 	/*
1371 	 * Any underflow of jump_target is guaranteed to be outside the range
1372 	 * of a u32, so >= test catches both too large and too small
1373 	 */
1374 	if (jump_offset >= batch_length) {
1375 		DRM_DEBUG("CMD: BB_START to 0x%llx jumps out of BB\n",
1376 			  jump_target);
1377 		return -EINVAL;
1378 	}
1379 
1380 	/*
1381 	 * This cannot overflow a u32 because we already checked jump_offset
1382 	 * is within the BB, and the batch_length is a u32
1383 	 */
1384 	target_cmd_offset = lower_32_bits(jump_offset);
1385 	target_cmd_index = target_cmd_offset / sizeof(u32);
1386 
1387 	*(u64 *)(cmd + 1) = shadow_addr + target_cmd_offset;
1388 
1389 	if (target_cmd_index == offset)
1390 		return 0;
1391 
1392 	if (IS_ERR(jump_whitelist))
1393 		return PTR_ERR(jump_whitelist);
1394 
1395 	if (!test_bit(target_cmd_index, jump_whitelist)) {
1396 		DRM_DEBUG("CMD: BB_START to 0x%llx not a previously executed cmd\n",
1397 			  jump_target);
1398 		return -EINVAL;
1399 	}
1400 
1401 	return 0;
1402 }
1403 
1404 static unsigned long *alloc_whitelist(u32 batch_length)
1405 {
1406 	unsigned long *jmp;
1407 
1408 	/*
1409 	 * We expect batch_length to be less than 256KiB for known users,
1410 	 * i.e. we need at most an 8KiB bitmap allocation which should be
1411 	 * reasonably cheap due to kmalloc caches.
1412 	 */
1413 
1414 	/* Prefer to report transient allocation failure rather than hit oom */
1415 	jmp = bitmap_zalloc(DIV_ROUND_UP(batch_length, sizeof(u32)),
1416 			    GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_NOWARN);
1417 	if (!jmp)
1418 		return ERR_PTR(-ENOMEM);
1419 
1420 	return jmp;
1421 }
1422 
1423 #define LENGTH_BIAS 2
1424 
1425 /**
1426  * intel_engine_cmd_parser() - parse a batch buffer for privilege violations
1427  * @engine: the engine on which the batch is to execute
1428  * @batch: the batch buffer in question
1429  * @batch_offset: byte offset in the batch at which execution starts
1430  * @batch_length: length of the commands in batch_obj
1431  * @shadow: validated copy of the batch buffer in question
1432  * @trampoline: true if we need to trampoline into privileged execution
1433  *
1434  * Parses the specified batch buffer looking for privilege violations as
1435  * described in the overview.
1436  *
1437  * Return: non-zero if the parser finds violations or otherwise fails; -EACCES
1438  * if the batch appears legal but should use hardware parsing
1439  */
1440 
1441 int intel_engine_cmd_parser(struct intel_engine_cs *engine,
1442 			    struct i915_vma *batch,
1443 			    unsigned long batch_offset,
1444 			    unsigned long batch_length,
1445 			    struct i915_vma *shadow,
1446 			    bool trampoline)
1447 {
1448 	u32 *cmd, *batch_end, offset = 0;
1449 	struct drm_i915_cmd_descriptor default_desc = noop_desc;
1450 	const struct drm_i915_cmd_descriptor *desc = &default_desc;
1451 	bool needs_clflush_after = false;
1452 	unsigned long *jump_whitelist;
1453 	u64 batch_addr, shadow_addr;
1454 	int ret = 0;
1455 
1456 	GEM_BUG_ON(!IS_ALIGNED(batch_offset, sizeof(*cmd)));
1457 	GEM_BUG_ON(!IS_ALIGNED(batch_length, sizeof(*cmd)));
1458 	GEM_BUG_ON(range_overflows_t(u64, batch_offset, batch_length,
1459 				     batch->size));
1460 	GEM_BUG_ON(!batch_length);
1461 
1462 	cmd = copy_batch(shadow->obj, batch->obj,
1463 			 batch_offset, batch_length,
1464 			 &needs_clflush_after);
1465 	if (IS_ERR(cmd)) {
1466 		DRM_DEBUG("CMD: Failed to copy batch\n");
1467 		return PTR_ERR(cmd);
1468 	}
1469 
1470 	jump_whitelist = NULL;
1471 	if (!trampoline)
1472 		/* Defer failure until attempted use */
1473 		jump_whitelist = alloc_whitelist(batch_length);
1474 
1475 	shadow_addr = gen8_canonical_addr(i915_vma_offset(shadow));
1476 	batch_addr = gen8_canonical_addr(i915_vma_offset(batch) + batch_offset);
1477 
1478 	/*
1479 	 * We use the batch length as size because the shadow object is as
1480 	 * large or larger and copy_batch() will write MI_NOPs to the extra
1481 	 * space. Parsing should be faster in some cases this way.
1482 	 */
1483 	batch_end = cmd + batch_length / sizeof(*batch_end);
1484 	do {
1485 		u32 length;
1486 
1487 		if (*cmd == MI_BATCH_BUFFER_END)
1488 			break;
1489 
1490 		desc = find_cmd(engine, *cmd, desc, &default_desc);
1491 		if (!desc) {
1492 			DRM_DEBUG("CMD: Unrecognized command: 0x%08X\n", *cmd);
1493 			ret = -EINVAL;
1494 			break;
1495 		}
1496 
1497 		if (desc->flags & CMD_DESC_FIXED)
1498 			length = desc->length.fixed;
1499 		else
1500 			length = (*cmd & desc->length.mask) + LENGTH_BIAS;
1501 
1502 		if ((batch_end - cmd) < length) {
1503 			DRM_DEBUG("CMD: Command length exceeds batch length: 0x%08X length=%u batchlen=%td\n",
1504 				  *cmd,
1505 				  length,
1506 				  batch_end - cmd);
1507 			ret = -EINVAL;
1508 			break;
1509 		}
1510 
1511 		if (!check_cmd(engine, desc, cmd, length)) {
1512 			ret = -EACCES;
1513 			break;
1514 		}
1515 
1516 		if (cmd_desc_is(desc, MI_BATCH_BUFFER_START)) {
1517 			ret = check_bbstart(cmd, offset, length, batch_length,
1518 					    batch_addr, shadow_addr,
1519 					    jump_whitelist);
1520 			break;
1521 		}
1522 
1523 		if (!IS_ERR_OR_NULL(jump_whitelist))
1524 			__set_bit(offset, jump_whitelist);
1525 
1526 		cmd += length;
1527 		offset += length;
1528 		if  (cmd >= batch_end) {
1529 			DRM_DEBUG("CMD: Got to the end of the buffer w/o a BBE cmd!\n");
1530 			ret = -EINVAL;
1531 			break;
1532 		}
1533 	} while (1);
1534 
1535 	if (trampoline) {
1536 		/*
1537 		 * With the trampoline, the shadow is executed twice.
1538 		 *
1539 		 *   1 - starting at offset 0, in privileged mode
1540 		 *   2 - starting at offset batch_len, as non-privileged
1541 		 *
1542 		 * Only if the batch is valid and safe to execute, do we
1543 		 * allow the first privileged execution to proceed. If not,
1544 		 * we terminate the first batch and use the second batchbuffer
1545 		 * entry to chain to the original unsafe non-privileged batch,
1546 		 * leaving it to the HW to validate.
1547 		 */
1548 		*batch_end = MI_BATCH_BUFFER_END;
1549 
1550 		if (ret) {
1551 			/* Batch unsafe to execute with privileges, cancel! */
1552 			cmd = page_mask_bits(shadow->obj->mm.mapping);
1553 			*cmd = MI_BATCH_BUFFER_END;
1554 
1555 			/* If batch is unsafe but valid, jump to the original */
1556 			if (ret == -EACCES) {
1557 				unsigned int flags;
1558 
1559 				flags = MI_BATCH_NON_SECURE_I965;
1560 				if (IS_HASWELL(engine->i915))
1561 					flags = MI_BATCH_NON_SECURE_HSW;
1562 
1563 				GEM_BUG_ON(!IS_GRAPHICS_VER(engine->i915, 6, 7));
1564 				__gen6_emit_bb_start(batch_end,
1565 						     batch_addr,
1566 						     flags);
1567 
1568 				ret = 0; /* allow execution */
1569 			}
1570 		}
1571 	}
1572 
1573 	i915_gem_object_flush_map(shadow->obj);
1574 
1575 	if (!IS_ERR_OR_NULL(jump_whitelist))
1576 		kfree(jump_whitelist);
1577 	i915_gem_object_unpin_map(shadow->obj);
1578 	return ret;
1579 }
1580 
1581 /**
1582  * i915_cmd_parser_get_version() - get the cmd parser version number
1583  * @dev_priv: i915 device private
1584  *
1585  * The cmd parser maintains a simple increasing integer version number suitable
1586  * for passing to userspace clients to determine what operations are permitted.
1587  *
1588  * Return: the current version number of the cmd parser
1589  */
1590 int i915_cmd_parser_get_version(struct drm_i915_private *dev_priv)
1591 {
1592 	struct intel_engine_cs *engine;
1593 	bool active = false;
1594 
1595 	/* If the command parser is not enabled, report 0 - unsupported */
1596 	for_each_uabi_engine(engine, dev_priv) {
1597 		if (intel_engine_using_cmd_parser(engine)) {
1598 			active = true;
1599 			break;
1600 		}
1601 	}
1602 	if (!active)
1603 		return 0;
1604 
1605 	/*
1606 	 * Command parser version history
1607 	 *
1608 	 * 1. Initial version. Checks batches and reports violations, but leaves
1609 	 *    hardware parsing enabled (so does not allow new use cases).
1610 	 * 2. Allow access to the MI_PREDICATE_SRC0 and
1611 	 *    MI_PREDICATE_SRC1 registers.
1612 	 * 3. Allow access to the GPGPU_THREADS_DISPATCHED register.
1613 	 * 4. L3 atomic chicken bits of HSW_SCRATCH1 and HSW_ROW_CHICKEN3.
1614 	 * 5. GPGPU dispatch compute indirect registers.
1615 	 * 6. TIMESTAMP register and Haswell CS GPR registers
1616 	 * 7. Allow MI_LOAD_REGISTER_REG between whitelisted registers.
1617 	 * 8. Don't report cmd_check() failures as EINVAL errors to userspace;
1618 	 *    rely on the HW to NOOP disallowed commands as it would without
1619 	 *    the parser enabled.
1620 	 * 9. Don't whitelist or handle oacontrol specially, as ownership
1621 	 *    for oacontrol state is moving to i915-perf.
1622 	 * 10. Support for Gen9 BCS Parsing
1623 	 */
1624 	return 10;
1625 }
1626