xref: /dragonfly/sys/dev/drm/i915/i915_cmd_parser.c (revision 3568afc1)
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, .step = 2 }    ),
127 	CMD(  MI_STORE_REGISTER_MEM,            SMI,    F,  3,     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,  3,     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_SET_APPID,                     SMI,    F,  1,      S  ),
155 	CMD(  MI_DISPLAY_FLIP,                  SMI,   !F,  0xFF,   R  ),
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 
400 /*
401  * An individual whitelist entry granting access to register addr.  If
402  * mask is non-zero the argument of immediate register writes will be
403  * AND-ed with mask, and the command will be rejected if the result
404  * doesn't match value.
405  *
406  * Registers with non-zero mask are only allowed to be written using
407  * LRI.
408  */
409 struct drm_i915_reg_descriptor {
410 	u32 addr;
411 	u32 mask;
412 	u32 value;
413 };
414 
415 /* Convenience macro for adding 32-bit registers. */
416 #define REG32(address, ...)                             \
417 	{ .addr = address, __VA_ARGS__ }
418 
419 /*
420  * Convenience macro for adding 64-bit registers.
421  *
422  * Some registers that userspace accesses are 64 bits. The register
423  * access commands only allow 32-bit accesses. Hence, we have to include
424  * entries for both halves of the 64-bit registers.
425  */
426 #define REG64(addr)                                     \
427 	REG32(addr), REG32(addr + sizeof(u32))
428 
429 static const struct drm_i915_reg_descriptor gen7_render_regs[] = {
430 	REG64(GPGPU_THREADS_DISPATCHED),
431 	REG64(HS_INVOCATION_COUNT),
432 	REG64(DS_INVOCATION_COUNT),
433 	REG64(IA_VERTICES_COUNT),
434 	REG64(IA_PRIMITIVES_COUNT),
435 	REG64(VS_INVOCATION_COUNT),
436 	REG64(GS_INVOCATION_COUNT),
437 	REG64(GS_PRIMITIVES_COUNT),
438 	REG64(CL_INVOCATION_COUNT),
439 	REG64(CL_PRIMITIVES_COUNT),
440 	REG64(PS_INVOCATION_COUNT),
441 	REG64(PS_DEPTH_COUNT),
442 	REG32(OACONTROL), /* Only allowed for LRI and SRM. See below. */
443 	REG64(MI_PREDICATE_SRC0),
444 	REG64(MI_PREDICATE_SRC1),
445 	REG32(GEN7_3DPRIM_END_OFFSET),
446 	REG32(GEN7_3DPRIM_START_VERTEX),
447 	REG32(GEN7_3DPRIM_VERTEX_COUNT),
448 	REG32(GEN7_3DPRIM_INSTANCE_COUNT),
449 	REG32(GEN7_3DPRIM_START_INSTANCE),
450 	REG32(GEN7_3DPRIM_BASE_VERTEX),
451 	REG32(GEN7_GPGPU_DISPATCHDIMX),
452 	REG32(GEN7_GPGPU_DISPATCHDIMY),
453 	REG32(GEN7_GPGPU_DISPATCHDIMZ),
454 	REG64(GEN7_SO_NUM_PRIMS_WRITTEN(0)),
455 	REG64(GEN7_SO_NUM_PRIMS_WRITTEN(1)),
456 	REG64(GEN7_SO_NUM_PRIMS_WRITTEN(2)),
457 	REG64(GEN7_SO_NUM_PRIMS_WRITTEN(3)),
458 	REG64(GEN7_SO_PRIM_STORAGE_NEEDED(0)),
459 	REG64(GEN7_SO_PRIM_STORAGE_NEEDED(1)),
460 	REG64(GEN7_SO_PRIM_STORAGE_NEEDED(2)),
461 	REG64(GEN7_SO_PRIM_STORAGE_NEEDED(3)),
462 	REG32(GEN7_SO_WRITE_OFFSET(0)),
463 	REG32(GEN7_SO_WRITE_OFFSET(1)),
464 	REG32(GEN7_SO_WRITE_OFFSET(2)),
465 	REG32(GEN7_SO_WRITE_OFFSET(3)),
466 	REG32(GEN7_L3SQCREG1),
467 	REG32(GEN7_L3CNTLREG2),
468 	REG32(GEN7_L3CNTLREG3),
469 	REG32(HSW_SCRATCH1,
470 	      .mask = ~HSW_SCRATCH1_L3_DATA_ATOMICS_DISABLE,
471 	      .value = 0),
472 	REG32(HSW_ROW_CHICKEN3,
473 	      .mask = ~(HSW_ROW_CHICKEN3_L3_GLOBAL_ATOMICS_DISABLE << 16 |
474                         HSW_ROW_CHICKEN3_L3_GLOBAL_ATOMICS_DISABLE),
475 	      .value = 0),
476 };
477 
478 static const struct drm_i915_reg_descriptor gen7_blt_regs[] = {
479 	REG32(BCS_SWCTRL),
480 };
481 
482 static const struct drm_i915_reg_descriptor ivb_master_regs[] = {
483 	REG32(FORCEWAKE_MT),
484 	REG32(DERRMR),
485 	REG32(GEN7_PIPE_DE_LOAD_SL(PIPE_A)),
486 	REG32(GEN7_PIPE_DE_LOAD_SL(PIPE_B)),
487 	REG32(GEN7_PIPE_DE_LOAD_SL(PIPE_C)),
488 };
489 
490 static const struct drm_i915_reg_descriptor hsw_master_regs[] = {
491 	REG32(FORCEWAKE_MT),
492 	REG32(DERRMR),
493 };
494 
495 #undef REG64
496 #undef REG32
497 
498 static u32 gen7_render_get_cmd_length_mask(u32 cmd_header)
499 {
500 	u32 client = (cmd_header & INSTR_CLIENT_MASK) >> INSTR_CLIENT_SHIFT;
501 	u32 subclient =
502 		(cmd_header & INSTR_SUBCLIENT_MASK) >> INSTR_SUBCLIENT_SHIFT;
503 
504 	if (client == INSTR_MI_CLIENT)
505 		return 0x3F;
506 	else if (client == INSTR_RC_CLIENT) {
507 		if (subclient == INSTR_MEDIA_SUBCLIENT)
508 			return 0xFFFF;
509 		else
510 			return 0xFF;
511 	}
512 
513 	DRM_DEBUG_DRIVER("CMD: Abnormal rcs cmd length! 0x%08X\n", cmd_header);
514 	return 0;
515 }
516 
517 static u32 gen7_bsd_get_cmd_length_mask(u32 cmd_header)
518 {
519 	u32 client = (cmd_header & INSTR_CLIENT_MASK) >> INSTR_CLIENT_SHIFT;
520 	u32 subclient =
521 		(cmd_header & INSTR_SUBCLIENT_MASK) >> INSTR_SUBCLIENT_SHIFT;
522 	u32 op = (cmd_header & INSTR_26_TO_24_MASK) >> INSTR_26_TO_24_SHIFT;
523 
524 	if (client == INSTR_MI_CLIENT)
525 		return 0x3F;
526 	else if (client == INSTR_RC_CLIENT) {
527 		if (subclient == INSTR_MEDIA_SUBCLIENT) {
528 			if (op == 6)
529 				return 0xFFFF;
530 			else
531 				return 0xFFF;
532 		} else
533 			return 0xFF;
534 	}
535 
536 	DRM_DEBUG_DRIVER("CMD: Abnormal bsd cmd length! 0x%08X\n", cmd_header);
537 	return 0;
538 }
539 
540 static u32 gen7_blt_get_cmd_length_mask(u32 cmd_header)
541 {
542 	u32 client = (cmd_header & INSTR_CLIENT_MASK) >> INSTR_CLIENT_SHIFT;
543 
544 	if (client == INSTR_MI_CLIENT)
545 		return 0x3F;
546 	else if (client == INSTR_BC_CLIENT)
547 		return 0xFF;
548 
549 	DRM_DEBUG_DRIVER("CMD: Abnormal blt cmd length! 0x%08X\n", cmd_header);
550 	return 0;
551 }
552 
553 static bool validate_cmds_sorted(struct intel_engine_cs *ring,
554 				 const struct drm_i915_cmd_table *cmd_tables,
555 				 int cmd_table_count)
556 {
557 	int i;
558 	bool ret = true;
559 
560 	if (!cmd_tables || cmd_table_count == 0)
561 		return true;
562 
563 	for (i = 0; i < cmd_table_count; i++) {
564 		const struct drm_i915_cmd_table *table = &cmd_tables[i];
565 		u32 previous = 0;
566 		int j;
567 
568 		for (j = 0; j < table->count; j++) {
569 			const struct drm_i915_cmd_descriptor *desc =
570 				&table->table[j];
571 			u32 curr = desc->cmd.value & desc->cmd.mask;
572 
573 			if (curr < previous) {
574 				DRM_ERROR("CMD: table not sorted ring=%d table=%d entry=%d cmd=0x%08X prev=0x%08X\n",
575 					  ring->id, i, j, curr, previous);
576 				ret = false;
577 			}
578 
579 			previous = curr;
580 		}
581 	}
582 
583 	return ret;
584 }
585 
586 static bool check_sorted(int ring_id,
587 			 const struct drm_i915_reg_descriptor *reg_table,
588 			 int reg_count)
589 {
590 	int i;
591 	u32 previous = 0;
592 	bool ret = true;
593 
594 	for (i = 0; i < reg_count; i++) {
595 		u32 curr = reg_table[i].addr;
596 
597 		if (curr < previous) {
598 			DRM_ERROR("CMD: table not sorted ring=%d entry=%d reg=0x%08X prev=0x%08X\n",
599 				  ring_id, i, curr, previous);
600 			ret = false;
601 		}
602 
603 		previous = curr;
604 	}
605 
606 	return ret;
607 }
608 
609 static bool validate_regs_sorted(struct intel_engine_cs *ring)
610 {
611 	return check_sorted(ring->id, ring->reg_table, ring->reg_count) &&
612 		check_sorted(ring->id, ring->master_reg_table,
613 			     ring->master_reg_count);
614 }
615 
616 struct cmd_node {
617 	const struct drm_i915_cmd_descriptor *desc;
618 	struct hlist_node node;
619 };
620 
621 /*
622  * Different command ranges have different numbers of bits for the opcode. For
623  * example, MI commands use bits 31:23 while 3D commands use bits 31:16. The
624  * problem is that, for example, MI commands use bits 22:16 for other fields
625  * such as GGTT vs PPGTT bits. If we include those bits in the mask then when
626  * we mask a command from a batch it could hash to the wrong bucket due to
627  * non-opcode bits being set. But if we don't include those bits, some 3D
628  * commands may hash to the same bucket due to not including opcode bits that
629  * make the command unique. For now, we will risk hashing to the same bucket.
630  *
631  * If we attempt to generate a perfect hash, we should be able to look at bits
632  * 31:29 of a command from a batch buffer and use the full mask for that
633  * client. The existing INSTR_CLIENT_MASK/SHIFT defines can be used for this.
634  */
635 #define CMD_HASH_MASK STD_MI_OPCODE_MASK
636 
637 static int init_hash_table(struct intel_engine_cs *ring,
638 			   const struct drm_i915_cmd_table *cmd_tables,
639 			   int cmd_table_count)
640 {
641 #if 0
642 	int i, j;
643 
644 	hash_init(ring->cmd_hash);
645 
646 	for (i = 0; i < cmd_table_count; i++) {
647 		const struct drm_i915_cmd_table *table = &cmd_tables[i];
648 
649 		for (j = 0; j < table->count; j++) {
650 			const struct drm_i915_cmd_descriptor *desc =
651 				&table->table[j];
652 			struct cmd_node *desc_node =
653 				kmalloc(sizeof(*desc_node), M_DRM, M_WAITOK);
654 
655 			if (!desc_node)
656 				return -ENOMEM;
657 
658 			desc_node->desc = desc;
659 			hash_add(ring->cmd_hash, &desc_node->node,
660 				 desc->cmd.value & CMD_HASH_MASK);
661 		}
662 	}
663 #endif
664 
665 	return 0;
666 }
667 
668 static void fini_hash_table(struct intel_engine_cs *ring)
669 {
670 #if 0
671 	struct hlist_node *tmp;
672 	struct cmd_node *desc_node;
673 	int i;
674 
675 	hash_for_each_safe(ring->cmd_hash, i, tmp, desc_node, node) {
676 		hash_del(&desc_node->node);
677 		kfree(desc_node);
678 	}
679 #endif
680 }
681 
682 /**
683  * i915_cmd_parser_init_ring() - set cmd parser related fields for a ringbuffer
684  * @ring: the ringbuffer to initialize
685  *
686  * Optionally initializes fields related to batch buffer command parsing in the
687  * struct intel_engine_cs based on whether the platform requires software
688  * command parsing.
689  *
690  * Return: non-zero if initialization fails
691  */
692 int i915_cmd_parser_init_ring(struct intel_engine_cs *ring)
693 {
694 	const struct drm_i915_cmd_table *cmd_tables;
695 	int cmd_table_count;
696 	int ret;
697 
698 	if (!IS_GEN7(ring->dev))
699 		return 0;
700 
701 	switch (ring->id) {
702 	case RCS:
703 		if (IS_HASWELL(ring->dev)) {
704 			cmd_tables = hsw_render_ring_cmds;
705 			cmd_table_count =
706 				ARRAY_SIZE(hsw_render_ring_cmds);
707 		} else {
708 			cmd_tables = gen7_render_cmds;
709 			cmd_table_count = ARRAY_SIZE(gen7_render_cmds);
710 		}
711 
712 		ring->reg_table = gen7_render_regs;
713 		ring->reg_count = ARRAY_SIZE(gen7_render_regs);
714 
715 		if (IS_HASWELL(ring->dev)) {
716 			ring->master_reg_table = hsw_master_regs;
717 			ring->master_reg_count = ARRAY_SIZE(hsw_master_regs);
718 		} else {
719 			ring->master_reg_table = ivb_master_regs;
720 			ring->master_reg_count = ARRAY_SIZE(ivb_master_regs);
721 		}
722 
723 		ring->get_cmd_length_mask = gen7_render_get_cmd_length_mask;
724 		break;
725 	case VCS:
726 		cmd_tables = gen7_video_cmds;
727 		cmd_table_count = ARRAY_SIZE(gen7_video_cmds);
728 		ring->get_cmd_length_mask = gen7_bsd_get_cmd_length_mask;
729 		break;
730 	case BCS:
731 		if (IS_HASWELL(ring->dev)) {
732 			cmd_tables = hsw_blt_ring_cmds;
733 			cmd_table_count = ARRAY_SIZE(hsw_blt_ring_cmds);
734 		} else {
735 			cmd_tables = gen7_blt_cmds;
736 			cmd_table_count = ARRAY_SIZE(gen7_blt_cmds);
737 		}
738 
739 		ring->reg_table = gen7_blt_regs;
740 		ring->reg_count = ARRAY_SIZE(gen7_blt_regs);
741 
742 		if (IS_HASWELL(ring->dev)) {
743 			ring->master_reg_table = hsw_master_regs;
744 			ring->master_reg_count = ARRAY_SIZE(hsw_master_regs);
745 		} else {
746 			ring->master_reg_table = ivb_master_regs;
747 			ring->master_reg_count = ARRAY_SIZE(ivb_master_regs);
748 		}
749 
750 		ring->get_cmd_length_mask = gen7_blt_get_cmd_length_mask;
751 		break;
752 	case VECS:
753 		cmd_tables = hsw_vebox_cmds;
754 		cmd_table_count = ARRAY_SIZE(hsw_vebox_cmds);
755 		/* VECS can use the same length_mask function as VCS */
756 		ring->get_cmd_length_mask = gen7_bsd_get_cmd_length_mask;
757 		break;
758 	default:
759 		DRM_ERROR("CMD: cmd_parser_init with unknown ring: %d\n",
760 			  ring->id);
761 		BUG();
762 	}
763 
764 	BUG_ON(!validate_cmds_sorted(ring, cmd_tables, cmd_table_count));
765 	BUG_ON(!validate_regs_sorted(ring));
766 
767 #if 0
768 	WARN_ON(!hash_empty(ring->cmd_hash));
769 #endif
770 
771 	ret = init_hash_table(ring, cmd_tables, cmd_table_count);
772 	if (ret) {
773 		DRM_ERROR("CMD: cmd_parser_init failed!\n");
774 		fini_hash_table(ring);
775 		return ret;
776 	}
777 
778 	ring->needs_cmd_parser = true;
779 
780 	return 0;
781 }
782 
783 /**
784  * i915_cmd_parser_fini_ring() - clean up cmd parser related fields
785  * @ring: the ringbuffer to clean up
786  *
787  * Releases any resources related to command parsing that may have been
788  * initialized for the specified ring.
789  */
790 void i915_cmd_parser_fini_ring(struct intel_engine_cs *ring)
791 {
792 	if (!ring->needs_cmd_parser)
793 		return;
794 
795 	fini_hash_table(ring);
796 }
797 
798 static const struct drm_i915_cmd_descriptor*
799 find_cmd_in_table(struct intel_engine_cs *ring,
800 		  u32 cmd_header)
801 {
802 #if 0
803 	struct cmd_node *desc_node;
804 
805 	hash_for_each_possible(ring->cmd_hash, desc_node, node,
806 			       cmd_header & CMD_HASH_MASK) {
807 		const struct drm_i915_cmd_descriptor *desc = desc_node->desc;
808 		u32 masked_cmd = desc->cmd.mask & cmd_header;
809 		u32 masked_value = desc->cmd.value & desc->cmd.mask;
810 
811 		if (masked_cmd == masked_value)
812 			return desc;
813 	}
814 #endif
815 
816 	return NULL;
817 }
818 
819 /*
820  * Returns a pointer to a descriptor for the command specified by cmd_header.
821  *
822  * The caller must supply space for a default descriptor via the default_desc
823  * parameter. If no descriptor for the specified command exists in the ring's
824  * command parser tables, this function fills in default_desc based on the
825  * ring's default length encoding and returns default_desc.
826  */
827 static const struct drm_i915_cmd_descriptor*
828 find_cmd(struct intel_engine_cs *ring,
829 	 u32 cmd_header,
830 	 struct drm_i915_cmd_descriptor *default_desc)
831 {
832 	const struct drm_i915_cmd_descriptor *desc;
833 	u32 mask;
834 
835 	desc = find_cmd_in_table(ring, cmd_header);
836 	if (desc)
837 		return desc;
838 
839 	mask = ring->get_cmd_length_mask(cmd_header);
840 	if (!mask)
841 		return NULL;
842 
843 	BUG_ON(!default_desc);
844 	default_desc->flags = CMD_DESC_SKIP;
845 	default_desc->length.mask = mask;
846 
847 	return default_desc;
848 }
849 
850 static const struct drm_i915_reg_descriptor *
851 find_reg(const struct drm_i915_reg_descriptor *table,
852 	 int count, u32 addr)
853 {
854 	if (table) {
855 		int i;
856 
857 		for (i = 0; i < count; i++) {
858 			if (table[i].addr == addr)
859 				return &table[i];
860 		}
861 	}
862 
863 	return NULL;
864 }
865 
866 static u32 *vmap_batch(struct drm_i915_gem_object *obj,
867 		       unsigned start, unsigned len)
868 {
869 	int i;
870 	void *addr = NULL;
871 	struct sg_page_iter sg_iter;
872 	int first_page = start >> PAGE_SHIFT;
873 	int last_page = (len + start + 4095) >> PAGE_SHIFT;
874 	int npages = last_page - first_page;
875 	struct vm_page **pages;
876 
877 	pages = drm_malloc_ab(npages, sizeof(*pages));
878 	if (pages == NULL) {
879 		DRM_DEBUG_DRIVER("Failed to get space for pages\n");
880 		goto finish;
881 	}
882 
883 	i = 0;
884 	for_each_sg_page(obj->pages->sgl, &sg_iter, obj->pages->nents, first_page) {
885 		pages[i++] = sg_page_iter_page(&sg_iter);
886 		if (i == npages)
887 			break;
888 	}
889 
890 #if 0
891 	addr = vmap(pages, i, 0, PAGE_KERNEL);
892 	if (addr == NULL) {
893 		DRM_DEBUG_DRIVER("Failed to vmap pages\n");
894 		goto finish;
895 	}
896 #endif
897 
898 finish:
899 	if (pages)
900 		drm_free_large(pages);
901 	return (u32*)addr;
902 }
903 
904 /* Returns a vmap'd pointer to dest_obj, which the caller must unmap */
905 static u32 *copy_batch(struct drm_i915_gem_object *dest_obj,
906 		       struct drm_i915_gem_object *src_obj,
907 		       u32 batch_start_offset,
908 		       u32 batch_len)
909 {
910 	int needs_clflush = 0;
911 	char *src_base, *src;
912 	void *dst = NULL;
913 	int ret;
914 
915 	if (batch_len > dest_obj->base.size ||
916 	    batch_len + batch_start_offset > src_obj->base.size)
917 		return ERR_PTR(-E2BIG);
918 
919 	if (WARN_ON(dest_obj->pages_pin_count == 0))
920 		return ERR_PTR(-ENODEV);
921 
922 	ret = i915_gem_obj_prepare_shmem_read(src_obj, &needs_clflush);
923 	if (ret) {
924 		DRM_DEBUG_DRIVER("CMD: failed to prepare shadow batch\n");
925 		return ERR_PTR(ret);
926 	}
927 
928 	src_base = (char *)vmap_batch(src_obj, batch_start_offset, batch_len);
929 	if (!src_base) {
930 		DRM_DEBUG_DRIVER("CMD: Failed to vmap batch\n");
931 		ret = -ENOMEM;
932 		goto unpin_src;
933 	}
934 
935 	ret = i915_gem_object_set_to_cpu_domain(dest_obj, true);
936 	if (ret) {
937 		DRM_DEBUG_DRIVER("CMD: Failed to set shadow batch to CPU\n");
938 		goto unmap_src;
939 	}
940 
941 	dst = vmap_batch(dest_obj, 0, batch_len);
942 	if (!dst) {
943 		DRM_DEBUG_DRIVER("CMD: Failed to vmap shadow batch\n");
944 		ret = -ENOMEM;
945 		goto unmap_src;
946 	}
947 
948 	src = src_base + offset_in_page(batch_start_offset);
949 	if (needs_clflush)
950 		drm_clflush_virt_range(src, batch_len);
951 
952 	memcpy(dst, src, batch_len);
953 
954 unmap_src:
955 	vunmap(src_base);
956 unpin_src:
957 	i915_gem_object_unpin_pages(src_obj);
958 
959 	return ret ? ERR_PTR(ret) : dst;
960 }
961 
962 /**
963  * i915_needs_cmd_parser() - should a given ring use software command parsing?
964  * @ring: the ring in question
965  *
966  * Only certain platforms require software batch buffer command parsing, and
967  * only when enabled via module parameter.
968  *
969  * Return: true if the ring requires software command parsing
970  */
971 bool i915_needs_cmd_parser(struct intel_engine_cs *ring)
972 {
973 	if (!ring->needs_cmd_parser)
974 		return false;
975 
976 	if (!USES_PPGTT(ring->dev))
977 		return false;
978 
979 	return (i915.enable_cmd_parser == 1);
980 }
981 
982 static bool check_cmd(const struct intel_engine_cs *ring,
983 		      const struct drm_i915_cmd_descriptor *desc,
984 		      const u32 *cmd, u32 length,
985 		      const bool is_master,
986 		      bool *oacontrol_set)
987 {
988 	if (desc->flags & CMD_DESC_REJECT) {
989 		DRM_DEBUG_DRIVER("CMD: Rejected command: 0x%08X\n", *cmd);
990 		return false;
991 	}
992 
993 	if ((desc->flags & CMD_DESC_MASTER) && !is_master) {
994 		DRM_DEBUG_DRIVER("CMD: Rejected master-only command: 0x%08X\n",
995 				 *cmd);
996 		return false;
997 	}
998 
999 	if (desc->flags & CMD_DESC_REGISTER) {
1000 		/*
1001 		 * Get the distance between individual register offset
1002 		 * fields if the command can perform more than one
1003 		 * access at a time.
1004 		 */
1005 		const u32 step = desc->reg.step ? desc->reg.step : length;
1006 		u32 offset;
1007 
1008 		for (offset = desc->reg.offset; offset < length;
1009 		     offset += step) {
1010 			const u32 reg_addr = cmd[offset] & desc->reg.mask;
1011 			const struct drm_i915_reg_descriptor *reg =
1012 				find_reg(ring->reg_table, ring->reg_count,
1013 					 reg_addr);
1014 
1015 			if (!reg && is_master)
1016 				reg = find_reg(ring->master_reg_table,
1017 					       ring->master_reg_count,
1018 					       reg_addr);
1019 
1020 			if (!reg) {
1021 				DRM_DEBUG_DRIVER("CMD: Rejected register 0x%08X in command: 0x%08X (ring=%d)\n",
1022 						 reg_addr, *cmd, ring->id);
1023 				return false;
1024 			}
1025 
1026 			/*
1027 			 * OACONTROL requires some special handling for
1028 			 * writes. We want to make sure that any batch which
1029 			 * enables OA also disables it before the end of the
1030 			 * batch. The goal is to prevent one process from
1031 			 * snooping on the perf data from another process. To do
1032 			 * that, we need to check the value that will be written
1033 			 * to the register. Hence, limit OACONTROL writes to
1034 			 * only MI_LOAD_REGISTER_IMM commands.
1035 			 */
1036 			if (reg_addr == OACONTROL) {
1037 				if (desc->cmd.value == MI_LOAD_REGISTER_MEM) {
1038 					DRM_DEBUG_DRIVER("CMD: Rejected LRM to OACONTROL\n");
1039 					return false;
1040 				}
1041 
1042 				if (desc->cmd.value == MI_LOAD_REGISTER_IMM(1))
1043 					*oacontrol_set = (cmd[offset + 1] != 0);
1044 			}
1045 
1046 			/*
1047 			 * Check the value written to the register against the
1048 			 * allowed mask/value pair given in the whitelist entry.
1049 			 */
1050 			if (reg->mask) {
1051 				if (desc->cmd.value == MI_LOAD_REGISTER_MEM) {
1052 					DRM_DEBUG_DRIVER("CMD: Rejected LRM to masked register 0x%08X\n",
1053 							 reg_addr);
1054 					return false;
1055 				}
1056 
1057 				if (desc->cmd.value == MI_LOAD_REGISTER_IMM(1) &&
1058 				    (offset + 2 > length ||
1059 				     (cmd[offset + 1] & reg->mask) != reg->value)) {
1060 					DRM_DEBUG_DRIVER("CMD: Rejected LRI to masked register 0x%08X\n",
1061 							 reg_addr);
1062 					return false;
1063 				}
1064 			}
1065 		}
1066 	}
1067 
1068 	if (desc->flags & CMD_DESC_BITMASK) {
1069 		int i;
1070 
1071 		for (i = 0; i < MAX_CMD_DESC_BITMASKS; i++) {
1072 			u32 dword;
1073 
1074 			if (desc->bits[i].mask == 0)
1075 				break;
1076 
1077 			if (desc->bits[i].condition_mask != 0) {
1078 				u32 offset =
1079 					desc->bits[i].condition_offset;
1080 				u32 condition = cmd[offset] &
1081 					desc->bits[i].condition_mask;
1082 
1083 				if (condition == 0)
1084 					continue;
1085 			}
1086 
1087 			dword = cmd[desc->bits[i].offset] &
1088 				desc->bits[i].mask;
1089 
1090 			if (dword != desc->bits[i].expected) {
1091 				DRM_DEBUG_DRIVER("CMD: Rejected command 0x%08X for bitmask 0x%08X (exp=0x%08X act=0x%08X) (ring=%d)\n",
1092 						 *cmd,
1093 						 desc->bits[i].mask,
1094 						 desc->bits[i].expected,
1095 						 dword, ring->id);
1096 				return false;
1097 			}
1098 		}
1099 	}
1100 
1101 	return true;
1102 }
1103 
1104 #define LENGTH_BIAS 2
1105 
1106 /**
1107  * i915_parse_cmds() - parse a submitted batch buffer for privilege violations
1108  * @ring: the ring on which the batch is to execute
1109  * @batch_obj: the batch buffer in question
1110  * @shadow_batch_obj: copy of the batch buffer in question
1111  * @batch_start_offset: byte offset in the batch at which execution starts
1112  * @batch_len: length of the commands in batch_obj
1113  * @is_master: is the submitting process the drm master?
1114  *
1115  * Parses the specified batch buffer looking for privilege violations as
1116  * described in the overview.
1117  *
1118  * Return: non-zero if the parser finds violations or otherwise fails; -EACCES
1119  * if the batch appears legal but should use hardware parsing
1120  */
1121 int i915_parse_cmds(struct intel_engine_cs *ring,
1122 		    struct drm_i915_gem_object *batch_obj,
1123 		    struct drm_i915_gem_object *shadow_batch_obj,
1124 		    u32 batch_start_offset,
1125 		    u32 batch_len,
1126 		    bool is_master)
1127 {
1128 	u32 *cmd, *batch_base, *batch_end;
1129 	struct drm_i915_cmd_descriptor default_desc = { 0 };
1130 	bool oacontrol_set = false; /* OACONTROL tracking. See check_cmd() */
1131 	int ret = 0;
1132 
1133 	batch_base = copy_batch(shadow_batch_obj, batch_obj,
1134 				batch_start_offset, batch_len);
1135 	if (IS_ERR(batch_base)) {
1136 		DRM_DEBUG_DRIVER("CMD: Failed to copy batch\n");
1137 		return PTR_ERR(batch_base);
1138 	}
1139 
1140 	/*
1141 	 * We use the batch length as size because the shadow object is as
1142 	 * large or larger and copy_batch() will write MI_NOPs to the extra
1143 	 * space. Parsing should be faster in some cases this way.
1144 	 */
1145 	batch_end = batch_base + (batch_len / sizeof(*batch_end));
1146 
1147 	cmd = batch_base;
1148 	while (cmd < batch_end) {
1149 		const struct drm_i915_cmd_descriptor *desc;
1150 		u32 length;
1151 
1152 		if (*cmd == MI_BATCH_BUFFER_END)
1153 			break;
1154 
1155 		desc = find_cmd(ring, *cmd, &default_desc);
1156 		if (!desc) {
1157 			DRM_DEBUG_DRIVER("CMD: Unrecognized command: 0x%08X\n",
1158 					 *cmd);
1159 			ret = -EINVAL;
1160 			break;
1161 		}
1162 
1163 		/*
1164 		 * If the batch buffer contains a chained batch, return an
1165 		 * error that tells the caller to abort and dispatch the
1166 		 * workload as a non-secure batch.
1167 		 */
1168 		if (desc->cmd.value == MI_BATCH_BUFFER_START) {
1169 			ret = -EACCES;
1170 			break;
1171 		}
1172 
1173 		if (desc->flags & CMD_DESC_FIXED)
1174 			length = desc->length.fixed;
1175 		else
1176 			length = ((*cmd & desc->length.mask) + LENGTH_BIAS);
1177 
1178 		if ((batch_end - cmd) < length) {
1179 			DRM_DEBUG_DRIVER("CMD: Command length exceeds batch length: 0x%08X length=%u batchlen=%td\n",
1180 					 *cmd,
1181 					 length,
1182 					 batch_end - cmd);
1183 			ret = -EINVAL;
1184 			break;
1185 		}
1186 
1187 		if (!check_cmd(ring, desc, cmd, length, is_master,
1188 			       &oacontrol_set)) {
1189 			ret = -EINVAL;
1190 			break;
1191 		}
1192 
1193 		cmd += length;
1194 	}
1195 
1196 	if (oacontrol_set) {
1197 		DRM_DEBUG_DRIVER("CMD: batch set OACONTROL but did not clear it\n");
1198 		ret = -EINVAL;
1199 	}
1200 
1201 	if (cmd >= batch_end) {
1202 		DRM_DEBUG_DRIVER("CMD: Got to the end of the buffer w/o a BBE cmd!\n");
1203 		ret = -EINVAL;
1204 	}
1205 
1206 	vunmap(batch_base);
1207 
1208 	return ret;
1209 }
1210 
1211 /**
1212  * i915_cmd_parser_get_version() - get the cmd parser version number
1213  *
1214  * The cmd parser maintains a simple increasing integer version number suitable
1215  * for passing to userspace clients to determine what operations are permitted.
1216  *
1217  * Return: the current version number of the cmd parser
1218  */
1219 int i915_cmd_parser_get_version(void)
1220 {
1221 	/*
1222 	 * Command parser version history
1223 	 *
1224 	 * 1. Initial version. Checks batches and reports violations, but leaves
1225 	 *    hardware parsing enabled (so does not allow new use cases).
1226 	 * 2. Allow access to the MI_PREDICATE_SRC0 and
1227 	 *    MI_PREDICATE_SRC1 registers.
1228 	 * 3. Allow access to the GPGPU_THREADS_DISPATCHED register.
1229 	 * 4. L3 atomic chicken bits of HSW_SCRATCH1 and HSW_ROW_CHICKEN3.
1230 	 * 5. GPGPU dispatch compute indirect registers.
1231 	 */
1232 	return 5;
1233 }
1234