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 "i915_drv.h"
29 
30 /**
31  * DOC: batch buffer command parser
32  *
33  * Motivation:
34  * Certain OpenGL features (e.g. transform feedback, performance monitoring)
35  * require userspace code to submit batches containing commands such as
36  * MI_LOAD_REGISTER_IMM to access various registers. Unfortunately, some
37  * generations of the hardware will noop these commands in "unsecure" batches
38  * (which includes all userspace batches submitted via i915) even though the
39  * commands may be safe and represent the intended programming model of the
40  * device.
41  *
42  * The software command parser is similar in operation to the command parsing
43  * done in hardware for unsecure batches. However, the software parser allows
44  * some operations that would be noop'd by hardware, if the parser determines
45  * the operation is safe, and submits the batch as "secure" to prevent hardware
46  * parsing.
47  *
48  * Threats:
49  * At a high level, the hardware (and software) checks attempt to prevent
50  * granting userspace undue privileges. There are three categories of privilege.
51  *
52  * First, commands which are explicitly defined as privileged or which should
53  * only be used by the kernel driver. The parser generally rejects such
54  * commands, though it may allow some from the drm master process.
55  *
56  * Second, commands which access registers. To support correct/enhanced
57  * userspace functionality, particularly certain OpenGL extensions, the parser
58  * provides a whitelist of registers which userspace may safely access (for both
59  * normal and drm master processes).
60  *
61  * Third, commands which access privileged memory (i.e. GGTT, HWS page, etc).
62  * The parser always rejects such commands.
63  *
64  * The majority of the problematic commands fall in the MI_* range, with only a
65  * few specific commands on each ring (e.g. PIPE_CONTROL and MI_FLUSH_DW).
66  *
67  * Implementation:
68  * Each ring maintains tables of commands and registers which the parser uses in
69  * scanning batch buffers submitted to that ring.
70  *
71  * Since the set of commands that the parser must check for is significantly
72  * smaller than the number of commands supported, the parser tables contain only
73  * those commands required by the parser. This generally works because command
74  * opcode ranges have standard command length encodings. So for commands that
75  * the parser does not need to check, it can easily skip them. This is
76  * implemented via a per-ring length decoding vfunc.
77  *
78  * Unfortunately, there are a number of commands that do not follow the standard
79  * length encoding for their opcode range, primarily amongst the MI_* commands.
80  * To handle this, the parser provides a way to define explicit "skip" entries
81  * in the per-ring command tables.
82  *
83  * Other command table entries map fairly directly to high level categories
84  * mentioned above: rejected, master-only, register whitelist. The parser
85  * implements a number of checks, including the privileged memory checks, via a
86  * general bitmasking mechanism.
87  */
88 
89 #define STD_MI_OPCODE_MASK  0xFF800000
90 #define STD_3D_OPCODE_MASK  0xFFFF0000
91 #define STD_2D_OPCODE_MASK  0xFFC00000
92 #define STD_MFX_OPCODE_MASK 0xFFFF0000
93 
94 #define CMD(op, opm, f, lm, fl, ...)				\
95 	{							\
96 		.flags = (fl) | ((f) ? CMD_DESC_FIXED : 0),	\
97 		.cmd = { (op), (opm) }, 			\
98 		.length = { (lm) },				\
99 		__VA_ARGS__					\
100 	}
101 
102 /* Convenience macros to compress the tables */
103 #define SMI STD_MI_OPCODE_MASK
104 #define S3D STD_3D_OPCODE_MASK
105 #define S2D STD_2D_OPCODE_MASK
106 #define SMFX STD_MFX_OPCODE_MASK
107 #define F true
108 #define S CMD_DESC_SKIP
109 #define R CMD_DESC_REJECT
110 #define W CMD_DESC_REGISTER
111 #define B CMD_DESC_BITMASK
112 #define M CMD_DESC_MASTER
113 
114 /*            Command                          Mask   Fixed Len   Action
115 	      ---------------------------------------------------------- */
116 static const struct drm_i915_cmd_descriptor common_cmds[] = {
117 	CMD(  MI_NOOP,                          SMI,    F,  1,      S  ),
118 	CMD(  MI_USER_INTERRUPT,                SMI,    F,  1,      R  ),
119 	CMD(  MI_WAIT_FOR_EVENT,                SMI,    F,  1,      M  ),
120 	CMD(  MI_ARB_CHECK,                     SMI,    F,  1,      S  ),
121 	CMD(  MI_REPORT_HEAD,                   SMI,    F,  1,      S  ),
122 	CMD(  MI_SUSPEND_FLUSH,                 SMI,    F,  1,      S  ),
123 	CMD(  MI_SEMAPHORE_MBOX,                SMI,   !F,  0xFF,   R  ),
124 	CMD(  MI_STORE_DWORD_INDEX,             SMI,   !F,  0xFF,   R  ),
125 	CMD(  MI_LOAD_REGISTER_IMM(1),          SMI,   !F,  0xFF,   W,
126 	      .reg = { .offset = 1, .mask = 0x007FFFFC }               ),
127 	CMD(  MI_STORE_REGISTER_MEM(1),         SMI,   !F,  0xFF,   W | B,
128 	      .reg = { .offset = 1, .mask = 0x007FFFFC },
129 	      .bits = {{
130 			.offset = 0,
131 			.mask = MI_GLOBAL_GTT,
132 			.expected = 0,
133 	      }},						       ),
134 	CMD(  MI_LOAD_REGISTER_MEM,             SMI,   !F,  0xFF,   W | B,
135 	      .reg = { .offset = 1, .mask = 0x007FFFFC },
136 	      .bits = {{
137 			.offset = 0,
138 			.mask = MI_GLOBAL_GTT,
139 			.expected = 0,
140 	      }},						       ),
141 	/*
142 	 * MI_BATCH_BUFFER_START requires some special handling. It's not
143 	 * really a 'skip' action but it doesn't seem like it's worth adding
144 	 * a new action. See i915_parse_cmds().
145 	 */
146 	CMD(  MI_BATCH_BUFFER_START,            SMI,   !F,  0xFF,   S  ),
147 };
148 
149 static const struct drm_i915_cmd_descriptor render_cmds[] = {
150 	CMD(  MI_FLUSH,                         SMI,    F,  1,      S  ),
151 	CMD(  MI_ARB_ON_OFF,                    SMI,    F,  1,      R  ),
152 	CMD(  MI_PREDICATE,                     SMI,    F,  1,      S  ),
153 	CMD(  MI_TOPOLOGY_FILTER,               SMI,    F,  1,      S  ),
154 	CMD(  MI_DISPLAY_FLIP,                  SMI,   !F,  0xFF,   R  ),
155 	CMD(  MI_SET_APPID,                     SMI,    F,  1,      S  ),
156 	CMD(  MI_SET_CONTEXT,                   SMI,   !F,  0xFF,   R  ),
157 	CMD(  MI_URB_CLEAR,                     SMI,   !F,  0xFF,   S  ),
158 	CMD(  MI_STORE_DWORD_IMM,               SMI,   !F,  0x3F,   B,
159 	      .bits = {{
160 			.offset = 0,
161 			.mask = MI_GLOBAL_GTT,
162 			.expected = 0,
163 	      }},						       ),
164 	CMD(  MI_UPDATE_GTT,                    SMI,   !F,  0xFF,   R  ),
165 	CMD(  MI_CLFLUSH,                       SMI,   !F,  0x3FF,  B,
166 	      .bits = {{
167 			.offset = 0,
168 			.mask = MI_GLOBAL_GTT,
169 			.expected = 0,
170 	      }},						       ),
171 	CMD(  MI_REPORT_PERF_COUNT,             SMI,   !F,  0x3F,   B,
172 	      .bits = {{
173 			.offset = 1,
174 			.mask = MI_REPORT_PERF_COUNT_GGTT,
175 			.expected = 0,
176 	      }},						       ),
177 	CMD(  MI_CONDITIONAL_BATCH_BUFFER_END,  SMI,   !F,  0xFF,   B,
178 	      .bits = {{
179 			.offset = 0,
180 			.mask = MI_GLOBAL_GTT,
181 			.expected = 0,
182 	      }},						       ),
183 	CMD(  GFX_OP_3DSTATE_VF_STATISTICS,     S3D,    F,  1,      S  ),
184 	CMD(  PIPELINE_SELECT,                  S3D,    F,  1,      S  ),
185 	CMD(  MEDIA_VFE_STATE,			S3D,   !F,  0xFFFF, B,
186 	      .bits = {{
187 			.offset = 2,
188 			.mask = MEDIA_VFE_STATE_MMIO_ACCESS_MASK,
189 			.expected = 0,
190 	      }},						       ),
191 	CMD(  GPGPU_OBJECT,                     S3D,   !F,  0xFF,   S  ),
192 	CMD(  GPGPU_WALKER,                     S3D,   !F,  0xFF,   S  ),
193 	CMD(  GFX_OP_3DSTATE_SO_DECL_LIST,      S3D,   !F,  0x1FF,  S  ),
194 	CMD(  GFX_OP_PIPE_CONTROL(5),           S3D,   !F,  0xFF,   B,
195 	      .bits = {{
196 			.offset = 1,
197 			.mask = (PIPE_CONTROL_MMIO_WRITE | PIPE_CONTROL_NOTIFY),
198 			.expected = 0,
199 	      },
200 	      {
201 			.offset = 1,
202 		        .mask = (PIPE_CONTROL_GLOBAL_GTT_IVB |
203 				 PIPE_CONTROL_STORE_DATA_INDEX),
204 			.expected = 0,
205 			.condition_offset = 1,
206 			.condition_mask = PIPE_CONTROL_POST_SYNC_OP_MASK,
207 	      }},						       ),
208 };
209 
210 static const struct drm_i915_cmd_descriptor hsw_render_cmds[] = {
211 	CMD(  MI_SET_PREDICATE,                 SMI,    F,  1,      S  ),
212 	CMD(  MI_RS_CONTROL,                    SMI,    F,  1,      S  ),
213 	CMD(  MI_URB_ATOMIC_ALLOC,              SMI,    F,  1,      S  ),
214 	CMD(  MI_SET_APPID,                     SMI,    F,  1,      S  ),
215 	CMD(  MI_RS_CONTEXT,                    SMI,    F,  1,      S  ),
216 	CMD(  MI_LOAD_SCAN_LINES_INCL,          SMI,   !F,  0x3F,   M  ),
217 	CMD(  MI_LOAD_SCAN_LINES_EXCL,          SMI,   !F,  0x3F,   R  ),
218 	CMD(  MI_LOAD_REGISTER_REG,             SMI,   !F,  0xFF,   R  ),
219 	CMD(  MI_RS_STORE_DATA_IMM,             SMI,   !F,  0xFF,   S  ),
220 	CMD(  MI_LOAD_URB_MEM,                  SMI,   !F,  0xFF,   S  ),
221 	CMD(  MI_STORE_URB_MEM,                 SMI,   !F,  0xFF,   S  ),
222 	CMD(  GFX_OP_3DSTATE_DX9_CONSTANTF_VS,  S3D,   !F,  0x7FF,  S  ),
223 	CMD(  GFX_OP_3DSTATE_DX9_CONSTANTF_PS,  S3D,   !F,  0x7FF,  S  ),
224 
225 	CMD(  GFX_OP_3DSTATE_BINDING_TABLE_EDIT_VS,  S3D,   !F,  0x1FF,  S  ),
226 	CMD(  GFX_OP_3DSTATE_BINDING_TABLE_EDIT_GS,  S3D,   !F,  0x1FF,  S  ),
227 	CMD(  GFX_OP_3DSTATE_BINDING_TABLE_EDIT_HS,  S3D,   !F,  0x1FF,  S  ),
228 	CMD(  GFX_OP_3DSTATE_BINDING_TABLE_EDIT_DS,  S3D,   !F,  0x1FF,  S  ),
229 	CMD(  GFX_OP_3DSTATE_BINDING_TABLE_EDIT_PS,  S3D,   !F,  0x1FF,  S  ),
230 };
231 
232 static const struct drm_i915_cmd_descriptor video_cmds[] = {
233 	CMD(  MI_ARB_ON_OFF,                    SMI,    F,  1,      R  ),
234 	CMD(  MI_SET_APPID,                     SMI,    F,  1,      S  ),
235 	CMD(  MI_STORE_DWORD_IMM,               SMI,   !F,  0xFF,   B,
236 	      .bits = {{
237 			.offset = 0,
238 			.mask = MI_GLOBAL_GTT,
239 			.expected = 0,
240 	      }},						       ),
241 	CMD(  MI_UPDATE_GTT,                    SMI,   !F,  0x3F,   R  ),
242 	CMD(  MI_FLUSH_DW,                      SMI,   !F,  0x3F,   B,
243 	      .bits = {{
244 			.offset = 0,
245 			.mask = MI_FLUSH_DW_NOTIFY,
246 			.expected = 0,
247 	      },
248 	      {
249 			.offset = 1,
250 			.mask = MI_FLUSH_DW_USE_GTT,
251 			.expected = 0,
252 			.condition_offset = 0,
253 			.condition_mask = MI_FLUSH_DW_OP_MASK,
254 	      },
255 	      {
256 			.offset = 0,
257 			.mask = MI_FLUSH_DW_STORE_INDEX,
258 			.expected = 0,
259 			.condition_offset = 0,
260 			.condition_mask = MI_FLUSH_DW_OP_MASK,
261 	      }},						       ),
262 	CMD(  MI_CONDITIONAL_BATCH_BUFFER_END,  SMI,   !F,  0xFF,   B,
263 	      .bits = {{
264 			.offset = 0,
265 			.mask = MI_GLOBAL_GTT,
266 			.expected = 0,
267 	      }},						       ),
268 	/*
269 	 * MFX_WAIT doesn't fit the way we handle length for most commands.
270 	 * It has a length field but it uses a non-standard length bias.
271 	 * It is always 1 dword though, so just treat it as fixed length.
272 	 */
273 	CMD(  MFX_WAIT,                         SMFX,   F,  1,      S  ),
274 };
275 
276 static const struct drm_i915_cmd_descriptor vecs_cmds[] = {
277 	CMD(  MI_ARB_ON_OFF,                    SMI,    F,  1,      R  ),
278 	CMD(  MI_SET_APPID,                     SMI,    F,  1,      S  ),
279 	CMD(  MI_STORE_DWORD_IMM,               SMI,   !F,  0xFF,   B,
280 	      .bits = {{
281 			.offset = 0,
282 			.mask = MI_GLOBAL_GTT,
283 			.expected = 0,
284 	      }},						       ),
285 	CMD(  MI_UPDATE_GTT,                    SMI,   !F,  0x3F,   R  ),
286 	CMD(  MI_FLUSH_DW,                      SMI,   !F,  0x3F,   B,
287 	      .bits = {{
288 			.offset = 0,
289 			.mask = MI_FLUSH_DW_NOTIFY,
290 			.expected = 0,
291 	      },
292 	      {
293 			.offset = 1,
294 			.mask = MI_FLUSH_DW_USE_GTT,
295 			.expected = 0,
296 			.condition_offset = 0,
297 			.condition_mask = MI_FLUSH_DW_OP_MASK,
298 	      },
299 	      {
300 			.offset = 0,
301 			.mask = MI_FLUSH_DW_STORE_INDEX,
302 			.expected = 0,
303 			.condition_offset = 0,
304 			.condition_mask = MI_FLUSH_DW_OP_MASK,
305 	      }},						       ),
306 	CMD(  MI_CONDITIONAL_BATCH_BUFFER_END,  SMI,   !F,  0xFF,   B,
307 	      .bits = {{
308 			.offset = 0,
309 			.mask = MI_GLOBAL_GTT,
310 			.expected = 0,
311 	      }},						       ),
312 };
313 
314 static const struct drm_i915_cmd_descriptor blt_cmds[] = {
315 	CMD(  MI_DISPLAY_FLIP,                  SMI,   !F,  0xFF,   R  ),
316 	CMD(  MI_STORE_DWORD_IMM,               SMI,   !F,  0x3FF,  B,
317 	      .bits = {{
318 			.offset = 0,
319 			.mask = MI_GLOBAL_GTT,
320 			.expected = 0,
321 	      }},						       ),
322 	CMD(  MI_UPDATE_GTT,                    SMI,   !F,  0x3F,   R  ),
323 	CMD(  MI_FLUSH_DW,                      SMI,   !F,  0x3F,   B,
324 	      .bits = {{
325 			.offset = 0,
326 			.mask = MI_FLUSH_DW_NOTIFY,
327 			.expected = 0,
328 	      },
329 	      {
330 			.offset = 1,
331 			.mask = MI_FLUSH_DW_USE_GTT,
332 			.expected = 0,
333 			.condition_offset = 0,
334 			.condition_mask = MI_FLUSH_DW_OP_MASK,
335 	      },
336 	      {
337 			.offset = 0,
338 			.mask = MI_FLUSH_DW_STORE_INDEX,
339 			.expected = 0,
340 			.condition_offset = 0,
341 			.condition_mask = MI_FLUSH_DW_OP_MASK,
342 	      }},						       ),
343 	CMD(  COLOR_BLT,                        S2D,   !F,  0x3F,   S  ),
344 	CMD(  SRC_COPY_BLT,                     S2D,   !F,  0x3F,   S  ),
345 };
346 
347 static const struct drm_i915_cmd_descriptor hsw_blt_cmds[] = {
348 	CMD(  MI_LOAD_SCAN_LINES_INCL,          SMI,   !F,  0x3F,   M  ),
349 	CMD(  MI_LOAD_SCAN_LINES_EXCL,          SMI,   !F,  0x3F,   R  ),
350 };
351 
352 #undef CMD
353 #undef SMI
354 #undef S3D
355 #undef S2D
356 #undef SMFX
357 #undef F
358 #undef S
359 #undef R
360 #undef W
361 #undef B
362 #undef M
363 
364 static const struct drm_i915_cmd_table gen7_render_cmds[] = {
365 	{ common_cmds, ARRAY_SIZE(common_cmds) },
366 	{ render_cmds, ARRAY_SIZE(render_cmds) },
367 };
368 
369 static const struct drm_i915_cmd_table hsw_render_ring_cmds[] = {
370 	{ common_cmds, ARRAY_SIZE(common_cmds) },
371 	{ render_cmds, ARRAY_SIZE(render_cmds) },
372 	{ hsw_render_cmds, ARRAY_SIZE(hsw_render_cmds) },
373 };
374 
375 static const struct drm_i915_cmd_table gen7_video_cmds[] = {
376 	{ common_cmds, ARRAY_SIZE(common_cmds) },
377 	{ video_cmds, ARRAY_SIZE(video_cmds) },
378 };
379 
380 static const struct drm_i915_cmd_table hsw_vebox_cmds[] = {
381 	{ common_cmds, ARRAY_SIZE(common_cmds) },
382 	{ vecs_cmds, ARRAY_SIZE(vecs_cmds) },
383 };
384 
385 static const struct drm_i915_cmd_table gen7_blt_cmds[] = {
386 	{ common_cmds, ARRAY_SIZE(common_cmds) },
387 	{ blt_cmds, ARRAY_SIZE(blt_cmds) },
388 };
389 
390 static const struct drm_i915_cmd_table hsw_blt_ring_cmds[] = {
391 	{ common_cmds, ARRAY_SIZE(common_cmds) },
392 	{ blt_cmds, ARRAY_SIZE(blt_cmds) },
393 	{ hsw_blt_cmds, ARRAY_SIZE(hsw_blt_cmds) },
394 };
395 
396 /*
397  * Register whitelists, sorted by increasing register offset.
398  *
399  * Some registers that userspace accesses are 64 bits. The register
400  * access commands only allow 32-bit accesses. Hence, we have to include
401  * entries for both halves of the 64-bit registers.
402  */
403 
404 /* Convenience macro for adding 64-bit registers */
405 #define REG64(addr) (addr), (addr + sizeof(u32))
406 
407 static const u32 gen7_render_regs[] = {
408 	REG64(GPGPU_THREADS_DISPATCHED),
409 	REG64(HS_INVOCATION_COUNT),
410 	REG64(DS_INVOCATION_COUNT),
411 	REG64(IA_VERTICES_COUNT),
412 	REG64(IA_PRIMITIVES_COUNT),
413 	REG64(VS_INVOCATION_COUNT),
414 	REG64(GS_INVOCATION_COUNT),
415 	REG64(GS_PRIMITIVES_COUNT),
416 	REG64(CL_INVOCATION_COUNT),
417 	REG64(CL_PRIMITIVES_COUNT),
418 	REG64(PS_INVOCATION_COUNT),
419 	REG64(PS_DEPTH_COUNT),
420 	OACONTROL, /* Only allowed for LRI and SRM. See below. */
421 	REG64(MI_PREDICATE_SRC0),
422 	REG64(MI_PREDICATE_SRC1),
423 	GEN7_3DPRIM_END_OFFSET,
424 	GEN7_3DPRIM_START_VERTEX,
425 	GEN7_3DPRIM_VERTEX_COUNT,
426 	GEN7_3DPRIM_INSTANCE_COUNT,
427 	GEN7_3DPRIM_START_INSTANCE,
428 	GEN7_3DPRIM_BASE_VERTEX,
429 	REG64(GEN7_SO_NUM_PRIMS_WRITTEN(0)),
430 	REG64(GEN7_SO_NUM_PRIMS_WRITTEN(1)),
431 	REG64(GEN7_SO_NUM_PRIMS_WRITTEN(2)),
432 	REG64(GEN7_SO_NUM_PRIMS_WRITTEN(3)),
433 	REG64(GEN7_SO_PRIM_STORAGE_NEEDED(0)),
434 	REG64(GEN7_SO_PRIM_STORAGE_NEEDED(1)),
435 	REG64(GEN7_SO_PRIM_STORAGE_NEEDED(2)),
436 	REG64(GEN7_SO_PRIM_STORAGE_NEEDED(3)),
437 	GEN7_SO_WRITE_OFFSET(0),
438 	GEN7_SO_WRITE_OFFSET(1),
439 	GEN7_SO_WRITE_OFFSET(2),
440 	GEN7_SO_WRITE_OFFSET(3),
441 	GEN7_L3SQCREG1,
442 	GEN7_L3CNTLREG2,
443 	GEN7_L3CNTLREG3,
444 };
445 
446 static const u32 gen7_blt_regs[] = {
447 	BCS_SWCTRL,
448 };
449 
450 static const u32 ivb_master_regs[] = {
451 	FORCEWAKE_MT,
452 	DERRMR,
453 	GEN7_PIPE_DE_LOAD_SL(PIPE_A),
454 	GEN7_PIPE_DE_LOAD_SL(PIPE_B),
455 	GEN7_PIPE_DE_LOAD_SL(PIPE_C),
456 };
457 
458 static const u32 hsw_master_regs[] = {
459 	FORCEWAKE_MT,
460 	DERRMR,
461 };
462 
463 #undef REG64
464 
465 static u32 gen7_render_get_cmd_length_mask(u32 cmd_header)
466 {
467 	u32 client = (cmd_header & INSTR_CLIENT_MASK) >> INSTR_CLIENT_SHIFT;
468 	u32 subclient =
469 		(cmd_header & INSTR_SUBCLIENT_MASK) >> INSTR_SUBCLIENT_SHIFT;
470 
471 	if (client == INSTR_MI_CLIENT)
472 		return 0x3F;
473 	else if (client == INSTR_RC_CLIENT) {
474 		if (subclient == INSTR_MEDIA_SUBCLIENT)
475 			return 0xFFFF;
476 		else
477 			return 0xFF;
478 	}
479 
480 	DRM_DEBUG_DRIVER("CMD: Abnormal rcs cmd length! 0x%08X\n", cmd_header);
481 	return 0;
482 }
483 
484 static u32 gen7_bsd_get_cmd_length_mask(u32 cmd_header)
485 {
486 	u32 client = (cmd_header & INSTR_CLIENT_MASK) >> INSTR_CLIENT_SHIFT;
487 	u32 subclient =
488 		(cmd_header & INSTR_SUBCLIENT_MASK) >> INSTR_SUBCLIENT_SHIFT;
489 	u32 op = (cmd_header & INSTR_26_TO_24_MASK) >> INSTR_26_TO_24_SHIFT;
490 
491 	if (client == INSTR_MI_CLIENT)
492 		return 0x3F;
493 	else if (client == INSTR_RC_CLIENT) {
494 		if (subclient == INSTR_MEDIA_SUBCLIENT) {
495 			if (op == 6)
496 				return 0xFFFF;
497 			else
498 				return 0xFFF;
499 		} else
500 			return 0xFF;
501 	}
502 
503 	DRM_DEBUG_DRIVER("CMD: Abnormal bsd cmd length! 0x%08X\n", cmd_header);
504 	return 0;
505 }
506 
507 static u32 gen7_blt_get_cmd_length_mask(u32 cmd_header)
508 {
509 	u32 client = (cmd_header & INSTR_CLIENT_MASK) >> INSTR_CLIENT_SHIFT;
510 
511 	if (client == INSTR_MI_CLIENT)
512 		return 0x3F;
513 	else if (client == INSTR_BC_CLIENT)
514 		return 0xFF;
515 
516 	DRM_DEBUG_DRIVER("CMD: Abnormal blt cmd length! 0x%08X\n", cmd_header);
517 	return 0;
518 }
519 
520 static bool validate_cmds_sorted(struct intel_engine_cs *ring,
521 				 const struct drm_i915_cmd_table *cmd_tables,
522 				 int cmd_table_count)
523 {
524 	int i;
525 	bool ret = true;
526 
527 	if (!cmd_tables || cmd_table_count == 0)
528 		return true;
529 
530 	for (i = 0; i < cmd_table_count; i++) {
531 		const struct drm_i915_cmd_table *table = &cmd_tables[i];
532 		u32 previous = 0;
533 		int j;
534 
535 		for (j = 0; j < table->count; j++) {
536 			const struct drm_i915_cmd_descriptor *desc =
537 				&table->table[i];
538 			u32 curr = desc->cmd.value & desc->cmd.mask;
539 
540 			if (curr < previous) {
541 				DRM_ERROR("CMD: table not sorted ring=%d table=%d entry=%d cmd=0x%08X prev=0x%08X\n",
542 					  ring->id, i, j, curr, previous);
543 				ret = false;
544 			}
545 
546 			previous = curr;
547 		}
548 	}
549 
550 	return ret;
551 }
552 
553 static bool check_sorted(int ring_id, const u32 *reg_table, int reg_count)
554 {
555 	int i;
556 	u32 previous = 0;
557 	bool ret = true;
558 
559 	for (i = 0; i < reg_count; i++) {
560 		u32 curr = reg_table[i];
561 
562 		if (curr < previous) {
563 			DRM_ERROR("CMD: table not sorted ring=%d entry=%d reg=0x%08X prev=0x%08X\n",
564 				  ring_id, i, curr, previous);
565 			ret = false;
566 		}
567 
568 		previous = curr;
569 	}
570 
571 	return ret;
572 }
573 
574 static bool validate_regs_sorted(struct intel_engine_cs *ring)
575 {
576 	return check_sorted(ring->id, ring->reg_table, ring->reg_count) &&
577 		check_sorted(ring->id, ring->master_reg_table,
578 			     ring->master_reg_count);
579 }
580 
581 struct cmd_node {
582 	const struct drm_i915_cmd_descriptor *desc;
583 	struct hlist_node node;
584 };
585 
586 /*
587  * Different command ranges have different numbers of bits for the opcode. For
588  * example, MI commands use bits 31:23 while 3D commands use bits 31:16. The
589  * problem is that, for example, MI commands use bits 22:16 for other fields
590  * such as GGTT vs PPGTT bits. If we include those bits in the mask then when
591  * we mask a command from a batch it could hash to the wrong bucket due to
592  * non-opcode bits being set. But if we don't include those bits, some 3D
593  * commands may hash to the same bucket due to not including opcode bits that
594  * make the command unique. For now, we will risk hashing to the same bucket.
595  *
596  * If we attempt to generate a perfect hash, we should be able to look at bits
597  * 31:29 of a command from a batch buffer and use the full mask for that
598  * client. The existing INSTR_CLIENT_MASK/SHIFT defines can be used for this.
599  */
600 #define CMD_HASH_MASK STD_MI_OPCODE_MASK
601 
602 static int init_hash_table(struct intel_engine_cs *ring,
603 			   const struct drm_i915_cmd_table *cmd_tables,
604 			   int cmd_table_count)
605 {
606 	int i, j;
607 
608 	hash_init(ring->cmd_hash);
609 
610 	for (i = 0; i < cmd_table_count; i++) {
611 		const struct drm_i915_cmd_table *table = &cmd_tables[i];
612 
613 		for (j = 0; j < table->count; j++) {
614 			const struct drm_i915_cmd_descriptor *desc =
615 				&table->table[j];
616 			struct cmd_node *desc_node =
617 				kmalloc(sizeof(*desc_node), GFP_KERNEL);
618 
619 			if (!desc_node)
620 				return -ENOMEM;
621 
622 			desc_node->desc = desc;
623 			hash_add(ring->cmd_hash, &desc_node->node,
624 				 desc->cmd.value & CMD_HASH_MASK);
625 		}
626 	}
627 
628 	return 0;
629 }
630 
631 static void fini_hash_table(struct intel_engine_cs *ring)
632 {
633 	struct hlist_node *tmp;
634 	struct cmd_node *desc_node;
635 	int i;
636 
637 	hash_for_each_safe(ring->cmd_hash, i, tmp, desc_node, node) {
638 		hash_del(&desc_node->node);
639 		kfree(desc_node);
640 	}
641 }
642 
643 /**
644  * i915_cmd_parser_init_ring() - set cmd parser related fields for a ringbuffer
645  * @ring: the ringbuffer to initialize
646  *
647  * Optionally initializes fields related to batch buffer command parsing in the
648  * struct intel_engine_cs based on whether the platform requires software
649  * command parsing.
650  *
651  * Return: non-zero if initialization fails
652  */
653 int i915_cmd_parser_init_ring(struct intel_engine_cs *ring)
654 {
655 	const struct drm_i915_cmd_table *cmd_tables;
656 	int cmd_table_count;
657 	int ret;
658 
659 	if (!IS_GEN7(ring->dev))
660 		return 0;
661 
662 	switch (ring->id) {
663 	case RCS:
664 		if (IS_HASWELL(ring->dev)) {
665 			cmd_tables = hsw_render_ring_cmds;
666 			cmd_table_count =
667 				ARRAY_SIZE(hsw_render_ring_cmds);
668 		} else {
669 			cmd_tables = gen7_render_cmds;
670 			cmd_table_count = ARRAY_SIZE(gen7_render_cmds);
671 		}
672 
673 		ring->reg_table = gen7_render_regs;
674 		ring->reg_count = ARRAY_SIZE(gen7_render_regs);
675 
676 		if (IS_HASWELL(ring->dev)) {
677 			ring->master_reg_table = hsw_master_regs;
678 			ring->master_reg_count = ARRAY_SIZE(hsw_master_regs);
679 		} else {
680 			ring->master_reg_table = ivb_master_regs;
681 			ring->master_reg_count = ARRAY_SIZE(ivb_master_regs);
682 		}
683 
684 		ring->get_cmd_length_mask = gen7_render_get_cmd_length_mask;
685 		break;
686 	case VCS:
687 		cmd_tables = gen7_video_cmds;
688 		cmd_table_count = ARRAY_SIZE(gen7_video_cmds);
689 		ring->get_cmd_length_mask = gen7_bsd_get_cmd_length_mask;
690 		break;
691 	case BCS:
692 		if (IS_HASWELL(ring->dev)) {
693 			cmd_tables = hsw_blt_ring_cmds;
694 			cmd_table_count = ARRAY_SIZE(hsw_blt_ring_cmds);
695 		} else {
696 			cmd_tables = gen7_blt_cmds;
697 			cmd_table_count = ARRAY_SIZE(gen7_blt_cmds);
698 		}
699 
700 		ring->reg_table = gen7_blt_regs;
701 		ring->reg_count = ARRAY_SIZE(gen7_blt_regs);
702 
703 		if (IS_HASWELL(ring->dev)) {
704 			ring->master_reg_table = hsw_master_regs;
705 			ring->master_reg_count = ARRAY_SIZE(hsw_master_regs);
706 		} else {
707 			ring->master_reg_table = ivb_master_regs;
708 			ring->master_reg_count = ARRAY_SIZE(ivb_master_regs);
709 		}
710 
711 		ring->get_cmd_length_mask = gen7_blt_get_cmd_length_mask;
712 		break;
713 	case VECS:
714 		cmd_tables = hsw_vebox_cmds;
715 		cmd_table_count = ARRAY_SIZE(hsw_vebox_cmds);
716 		/* VECS can use the same length_mask function as VCS */
717 		ring->get_cmd_length_mask = gen7_bsd_get_cmd_length_mask;
718 		break;
719 	default:
720 		DRM_ERROR("CMD: cmd_parser_init with unknown ring: %d\n",
721 			  ring->id);
722 		BUG();
723 	}
724 
725 	BUG_ON(!validate_cmds_sorted(ring, cmd_tables, cmd_table_count));
726 	BUG_ON(!validate_regs_sorted(ring));
727 
728 	WARN_ON(!hash_empty(ring->cmd_hash));
729 
730 	ret = init_hash_table(ring, cmd_tables, cmd_table_count);
731 	if (ret) {
732 		DRM_ERROR("CMD: cmd_parser_init failed!\n");
733 		fini_hash_table(ring);
734 		return ret;
735 	}
736 
737 	ring->needs_cmd_parser = true;
738 
739 	return 0;
740 }
741 
742 /**
743  * i915_cmd_parser_fini_ring() - clean up cmd parser related fields
744  * @ring: the ringbuffer to clean up
745  *
746  * Releases any resources related to command parsing that may have been
747  * initialized for the specified ring.
748  */
749 void i915_cmd_parser_fini_ring(struct intel_engine_cs *ring)
750 {
751 	if (!ring->needs_cmd_parser)
752 		return;
753 
754 	fini_hash_table(ring);
755 }
756 
757 static const struct drm_i915_cmd_descriptor*
758 find_cmd_in_table(struct intel_engine_cs *ring,
759 		  u32 cmd_header)
760 {
761 	struct cmd_node *desc_node;
762 
763 	hash_for_each_possible(ring->cmd_hash, desc_node, node,
764 			       cmd_header & CMD_HASH_MASK) {
765 		const struct drm_i915_cmd_descriptor *desc = desc_node->desc;
766 		u32 masked_cmd = desc->cmd.mask & cmd_header;
767 		u32 masked_value = desc->cmd.value & desc->cmd.mask;
768 
769 		if (masked_cmd == masked_value)
770 			return desc;
771 	}
772 
773 	return NULL;
774 }
775 
776 /*
777  * Returns a pointer to a descriptor for the command specified by cmd_header.
778  *
779  * The caller must supply space for a default descriptor via the default_desc
780  * parameter. If no descriptor for the specified command exists in the ring's
781  * command parser tables, this function fills in default_desc based on the
782  * ring's default length encoding and returns default_desc.
783  */
784 static const struct drm_i915_cmd_descriptor*
785 find_cmd(struct intel_engine_cs *ring,
786 	 u32 cmd_header,
787 	 struct drm_i915_cmd_descriptor *default_desc)
788 {
789 	const struct drm_i915_cmd_descriptor *desc;
790 	u32 mask;
791 
792 	desc = find_cmd_in_table(ring, cmd_header);
793 	if (desc)
794 		return desc;
795 
796 	mask = ring->get_cmd_length_mask(cmd_header);
797 	if (!mask)
798 		return NULL;
799 
800 	BUG_ON(!default_desc);
801 	default_desc->flags = CMD_DESC_SKIP;
802 	default_desc->length.mask = mask;
803 
804 	return default_desc;
805 }
806 
807 static bool valid_reg(const u32 *table, int count, u32 addr)
808 {
809 	if (table && count != 0) {
810 		int i;
811 
812 		for (i = 0; i < count; i++) {
813 			if (table[i] == addr)
814 				return true;
815 		}
816 	}
817 
818 	return false;
819 }
820 
821 static u32 *vmap_batch(struct drm_i915_gem_object *obj)
822 {
823 	int i;
824 	void *addr = NULL;
825 	struct sg_page_iter sg_iter;
826 	struct page **pages;
827 
828 	pages = drm_malloc_ab(obj->base.size >> PAGE_SHIFT, sizeof(*pages));
829 	if (pages == NULL) {
830 		DRM_DEBUG_DRIVER("Failed to get space for pages\n");
831 		goto finish;
832 	}
833 
834 	i = 0;
835 	for_each_sg_page(obj->pages->sgl, &sg_iter, obj->pages->nents, 0) {
836 		pages[i] = sg_page_iter_page(&sg_iter);
837 		i++;
838 	}
839 
840 	addr = vmap(pages, i, 0, PAGE_KERNEL);
841 	if (addr == NULL) {
842 		DRM_DEBUG_DRIVER("Failed to vmap pages\n");
843 		goto finish;
844 	}
845 
846 finish:
847 	if (pages)
848 		drm_free_large(pages);
849 	return (u32*)addr;
850 }
851 
852 /* Returns a vmap'd pointer to dest_obj, which the caller must unmap */
853 static u32 *copy_batch(struct drm_i915_gem_object *dest_obj,
854 		       struct drm_i915_gem_object *src_obj,
855 		       u32 batch_start_offset,
856 		       u32 batch_len)
857 {
858 	int ret = 0;
859 	int needs_clflush = 0;
860 	u32 *src_base, *dest_base = NULL;
861 	u32 *src_addr, *dest_addr;
862 	u32 offset = batch_start_offset / sizeof(*dest_addr);
863 	u32 end = batch_start_offset + batch_len;
864 
865 	if (end > dest_obj->base.size || end > src_obj->base.size)
866 		return ERR_PTR(-E2BIG);
867 
868 	ret = i915_gem_obj_prepare_shmem_read(src_obj, &needs_clflush);
869 	if (ret) {
870 		DRM_DEBUG_DRIVER("CMD: failed to prep read\n");
871 		return ERR_PTR(ret);
872 	}
873 
874 	src_base = vmap_batch(src_obj);
875 	if (!src_base) {
876 		DRM_DEBUG_DRIVER("CMD: Failed to vmap batch\n");
877 		ret = -ENOMEM;
878 		goto unpin_src;
879 	}
880 
881 	src_addr = src_base + offset;
882 
883 	if (needs_clflush)
884 		drm_clflush_virt_range((char *)src_addr, batch_len);
885 
886 	ret = i915_gem_object_set_to_cpu_domain(dest_obj, true);
887 	if (ret) {
888 		DRM_DEBUG_DRIVER("CMD: Failed to set batch CPU domain\n");
889 		goto unmap_src;
890 	}
891 
892 	dest_base = vmap_batch(dest_obj);
893 	if (!dest_base) {
894 		DRM_DEBUG_DRIVER("CMD: Failed to vmap shadow batch\n");
895 		ret = -ENOMEM;
896 		goto unmap_src;
897 	}
898 
899 	dest_addr = dest_base + offset;
900 
901 	if (batch_start_offset != 0)
902 		memset((u8 *)dest_base, 0, batch_start_offset);
903 
904 	memcpy(dest_addr, src_addr, batch_len);
905 	memset((u8 *)dest_addr + batch_len, 0, dest_obj->base.size - end);
906 
907 unmap_src:
908 	vunmap(src_base);
909 unpin_src:
910 	i915_gem_object_unpin_pages(src_obj);
911 
912 	return ret ? ERR_PTR(ret) : dest_base;
913 }
914 
915 /**
916  * i915_needs_cmd_parser() - should a given ring use software command parsing?
917  * @ring: the ring in question
918  *
919  * Only certain platforms require software batch buffer command parsing, and
920  * only when enabled via module parameter.
921  *
922  * Return: true if the ring requires software command parsing
923  */
924 bool i915_needs_cmd_parser(struct intel_engine_cs *ring)
925 {
926 	if (!ring->needs_cmd_parser)
927 		return false;
928 
929 	if (!USES_PPGTT(ring->dev))
930 		return false;
931 
932 	return (i915.enable_cmd_parser == 1);
933 }
934 
935 static bool check_cmd(const struct intel_engine_cs *ring,
936 		      const struct drm_i915_cmd_descriptor *desc,
937 		      const u32 *cmd,
938 		      const bool is_master,
939 		      bool *oacontrol_set)
940 {
941 	if (desc->flags & CMD_DESC_REJECT) {
942 		DRM_DEBUG_DRIVER("CMD: Rejected command: 0x%08X\n", *cmd);
943 		return false;
944 	}
945 
946 	if ((desc->flags & CMD_DESC_MASTER) && !is_master) {
947 		DRM_DEBUG_DRIVER("CMD: Rejected master-only command: 0x%08X\n",
948 				 *cmd);
949 		return false;
950 	}
951 
952 	if (desc->flags & CMD_DESC_REGISTER) {
953 		u32 reg_addr = cmd[desc->reg.offset] & desc->reg.mask;
954 
955 		/*
956 		 * OACONTROL requires some special handling for writes. We
957 		 * want to make sure that any batch which enables OA also
958 		 * disables it before the end of the batch. The goal is to
959 		 * prevent one process from snooping on the perf data from
960 		 * another process. To do that, we need to check the value
961 		 * that will be written to the register. Hence, limit
962 		 * OACONTROL writes to only MI_LOAD_REGISTER_IMM commands.
963 		 */
964 		if (reg_addr == OACONTROL) {
965 			if (desc->cmd.value == MI_LOAD_REGISTER_MEM) {
966 				DRM_DEBUG_DRIVER("CMD: Rejected LRM to OACONTROL\n");
967 				return false;
968 			}
969 
970 			if (desc->cmd.value == MI_LOAD_REGISTER_IMM(1))
971 				*oacontrol_set = (cmd[2] != 0);
972 		}
973 
974 		if (!valid_reg(ring->reg_table,
975 			       ring->reg_count, reg_addr)) {
976 			if (!is_master ||
977 			    !valid_reg(ring->master_reg_table,
978 				       ring->master_reg_count,
979 				       reg_addr)) {
980 				DRM_DEBUG_DRIVER("CMD: Rejected register 0x%08X in command: 0x%08X (ring=%d)\n",
981 						 reg_addr,
982 						 *cmd,
983 						 ring->id);
984 				return false;
985 			}
986 		}
987 	}
988 
989 	if (desc->flags & CMD_DESC_BITMASK) {
990 		int i;
991 
992 		for (i = 0; i < MAX_CMD_DESC_BITMASKS; i++) {
993 			u32 dword;
994 
995 			if (desc->bits[i].mask == 0)
996 				break;
997 
998 			if (desc->bits[i].condition_mask != 0) {
999 				u32 offset =
1000 					desc->bits[i].condition_offset;
1001 				u32 condition = cmd[offset] &
1002 					desc->bits[i].condition_mask;
1003 
1004 				if (condition == 0)
1005 					continue;
1006 			}
1007 
1008 			dword = cmd[desc->bits[i].offset] &
1009 				desc->bits[i].mask;
1010 
1011 			if (dword != desc->bits[i].expected) {
1012 				DRM_DEBUG_DRIVER("CMD: Rejected command 0x%08X for bitmask 0x%08X (exp=0x%08X act=0x%08X) (ring=%d)\n",
1013 						 *cmd,
1014 						 desc->bits[i].mask,
1015 						 desc->bits[i].expected,
1016 						 dword, ring->id);
1017 				return false;
1018 			}
1019 		}
1020 	}
1021 
1022 	return true;
1023 }
1024 
1025 #define LENGTH_BIAS 2
1026 
1027 /**
1028  * i915_parse_cmds() - parse a submitted batch buffer for privilege violations
1029  * @ring: the ring on which the batch is to execute
1030  * @batch_obj: the batch buffer in question
1031  * @shadow_batch_obj: copy of the batch buffer in question
1032  * @batch_start_offset: byte offset in the batch at which execution starts
1033  * @batch_len: length of the commands in batch_obj
1034  * @is_master: is the submitting process the drm master?
1035  *
1036  * Parses the specified batch buffer looking for privilege violations as
1037  * described in the overview.
1038  *
1039  * Return: non-zero if the parser finds violations or otherwise fails; -EACCES
1040  * if the batch appears legal but should use hardware parsing
1041  */
1042 int i915_parse_cmds(struct intel_engine_cs *ring,
1043 		    struct drm_i915_gem_object *batch_obj,
1044 		    struct drm_i915_gem_object *shadow_batch_obj,
1045 		    u32 batch_start_offset,
1046 		    u32 batch_len,
1047 		    bool is_master)
1048 {
1049 	int ret = 0;
1050 	u32 *cmd, *batch_base, *batch_end;
1051 	struct drm_i915_cmd_descriptor default_desc = { 0 };
1052 	bool oacontrol_set = false; /* OACONTROL tracking. See check_cmd() */
1053 
1054 	ret = i915_gem_obj_ggtt_pin(shadow_batch_obj, 4096, 0);
1055 	if (ret) {
1056 		DRM_DEBUG_DRIVER("CMD: Failed to pin shadow batch\n");
1057 		return -1;
1058 	}
1059 
1060 	batch_base = copy_batch(shadow_batch_obj, batch_obj,
1061 				batch_start_offset, batch_len);
1062 	if (IS_ERR(batch_base)) {
1063 		DRM_DEBUG_DRIVER("CMD: Failed to copy batch\n");
1064 		i915_gem_object_ggtt_unpin(shadow_batch_obj);
1065 		return PTR_ERR(batch_base);
1066 	}
1067 
1068 	cmd = batch_base + (batch_start_offset / sizeof(*cmd));
1069 
1070 	/*
1071 	 * We use the batch length as size because the shadow object is as
1072 	 * large or larger and copy_batch() will write MI_NOPs to the extra
1073 	 * space. Parsing should be faster in some cases this way.
1074 	 */
1075 	batch_end = cmd + (batch_len / sizeof(*batch_end));
1076 
1077 	while (cmd < batch_end) {
1078 		const struct drm_i915_cmd_descriptor *desc;
1079 		u32 length;
1080 
1081 		if (*cmd == MI_BATCH_BUFFER_END)
1082 			break;
1083 
1084 		desc = find_cmd(ring, *cmd, &default_desc);
1085 		if (!desc) {
1086 			DRM_DEBUG_DRIVER("CMD: Unrecognized command: 0x%08X\n",
1087 					 *cmd);
1088 			ret = -EINVAL;
1089 			break;
1090 		}
1091 
1092 		/*
1093 		 * If the batch buffer contains a chained batch, return an
1094 		 * error that tells the caller to abort and dispatch the
1095 		 * workload as a non-secure batch.
1096 		 */
1097 		if (desc->cmd.value == MI_BATCH_BUFFER_START) {
1098 			ret = -EACCES;
1099 			break;
1100 		}
1101 
1102 		if (desc->flags & CMD_DESC_FIXED)
1103 			length = desc->length.fixed;
1104 		else
1105 			length = ((*cmd & desc->length.mask) + LENGTH_BIAS);
1106 
1107 		if ((batch_end - cmd) < length) {
1108 			DRM_DEBUG_DRIVER("CMD: Command length exceeds batch length: 0x%08X length=%u batchlen=%td\n",
1109 					 *cmd,
1110 					 length,
1111 					 batch_end - cmd);
1112 			ret = -EINVAL;
1113 			break;
1114 		}
1115 
1116 		if (!check_cmd(ring, desc, cmd, is_master, &oacontrol_set)) {
1117 			ret = -EINVAL;
1118 			break;
1119 		}
1120 
1121 		cmd += length;
1122 	}
1123 
1124 	if (oacontrol_set) {
1125 		DRM_DEBUG_DRIVER("CMD: batch set OACONTROL but did not clear it\n");
1126 		ret = -EINVAL;
1127 	}
1128 
1129 	if (cmd >= batch_end) {
1130 		DRM_DEBUG_DRIVER("CMD: Got to the end of the buffer w/o a BBE cmd!\n");
1131 		ret = -EINVAL;
1132 	}
1133 
1134 	vunmap(batch_base);
1135 	i915_gem_object_ggtt_unpin(shadow_batch_obj);
1136 
1137 	return ret;
1138 }
1139 
1140 /**
1141  * i915_cmd_parser_get_version() - get the cmd parser version number
1142  *
1143  * The cmd parser maintains a simple increasing integer version number suitable
1144  * for passing to userspace clients to determine what operations are permitted.
1145  *
1146  * Return: the current version number of the cmd parser
1147  */
1148 int i915_cmd_parser_get_version(void)
1149 {
1150 	/*
1151 	 * Command parser version history
1152 	 *
1153 	 * 1. Initial version. Checks batches and reports violations, but leaves
1154 	 *    hardware parsing enabled (so does not allow new use cases).
1155 	 * 2. Allow access to the MI_PREDICATE_SRC0 and
1156 	 *    MI_PREDICATE_SRC1 registers.
1157 	 * 3. Allow access to the GPGPU_THREADS_DISPATCHED register.
1158 	 */
1159 	return 3;
1160 }
1161