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 "gt/intel_engine.h"
29 
30 #include "i915_drv.h"
31 
32 /**
33  * DOC: batch buffer command parser
34  *
35  * Motivation:
36  * Certain OpenGL features (e.g. transform feedback, performance monitoring)
37  * require userspace code to submit batches containing commands such as
38  * MI_LOAD_REGISTER_IMM to access various registers. Unfortunately, some
39  * generations of the hardware will noop these commands in "unsecure" batches
40  * (which includes all userspace batches submitted via i915) even though the
41  * commands may be safe and represent the intended programming model of the
42  * device.
43  *
44  * The software command parser is similar in operation to the command parsing
45  * done in hardware for unsecure batches. However, the software parser allows
46  * some operations that would be noop'd by hardware, if the parser determines
47  * the operation is safe, and submits the batch as "secure" to prevent hardware
48  * parsing.
49  *
50  * Threats:
51  * At a high level, the hardware (and software) checks attempt to prevent
52  * granting userspace undue privileges. There are three categories of privilege.
53  *
54  * First, commands which are explicitly defined as privileged or which should
55  * only be used by the kernel driver. The parser generally rejects such
56  * commands, though it may allow some from the drm master process.
57  *
58  * Second, commands which access registers. To support correct/enhanced
59  * userspace functionality, particularly certain OpenGL extensions, the parser
60  * provides a whitelist of registers which userspace may safely access (for both
61  * normal and drm master processes).
62  *
63  * Third, commands which access privileged memory (i.e. GGTT, HWS page, etc).
64  * The parser always rejects such commands.
65  *
66  * The majority of the problematic commands fall in the MI_* range, with only a
67  * few specific commands on each engine (e.g. PIPE_CONTROL and MI_FLUSH_DW).
68  *
69  * Implementation:
70  * Each engine maintains tables of commands and registers which the parser
71  * uses in scanning batch buffers submitted to that engine.
72  *
73  * Since the set of commands that the parser must check for is significantly
74  * smaller than the number of commands supported, the parser tables contain only
75  * those commands required by the parser. This generally works because command
76  * opcode ranges have standard command length encodings. So for commands that
77  * the parser does not need to check, it can easily skip them. This is
78  * implemented via a per-engine length decoding vfunc.
79  *
80  * Unfortunately, there are a number of commands that do not follow the standard
81  * length encoding for their opcode range, primarily amongst the MI_* commands.
82  * To handle this, the parser provides a way to define explicit "skip" entries
83  * in the per-engine command tables.
84  *
85  * Other command table entries map fairly directly to high level categories
86  * mentioned above: rejected, master-only, register whitelist. The parser
87  * implements a number of checks, including the privileged memory checks, via a
88  * general bitmasking mechanism.
89  */
90 
91 /*
92  * A command that requires special handling by the command parser.
93  */
94 struct drm_i915_cmd_descriptor {
95 	/*
96 	 * Flags describing how the command parser processes the command.
97 	 *
98 	 * CMD_DESC_FIXED: The command has a fixed length if this is set,
99 	 *                 a length mask if not set
100 	 * CMD_DESC_SKIP: The command is allowed but does not follow the
101 	 *                standard length encoding for the opcode range in
102 	 *                which it falls
103 	 * CMD_DESC_REJECT: The command is never allowed
104 	 * CMD_DESC_REGISTER: The command should be checked against the
105 	 *                    register whitelist for the appropriate ring
106 	 * CMD_DESC_MASTER: The command is allowed if the submitting process
107 	 *                  is the DRM master
108 	 */
109 	u32 flags;
110 #define CMD_DESC_FIXED    (1<<0)
111 #define CMD_DESC_SKIP     (1<<1)
112 #define CMD_DESC_REJECT   (1<<2)
113 #define CMD_DESC_REGISTER (1<<3)
114 #define CMD_DESC_BITMASK  (1<<4)
115 #define CMD_DESC_MASTER   (1<<5)
116 
117 	/*
118 	 * The command's unique identification bits and the bitmask to get them.
119 	 * This isn't strictly the opcode field as defined in the spec and may
120 	 * also include type, subtype, and/or subop fields.
121 	 */
122 	struct {
123 		u32 value;
124 		u32 mask;
125 	} cmd;
126 
127 	/*
128 	 * The command's length. The command is either fixed length (i.e. does
129 	 * not include a length field) or has a length field mask. The flag
130 	 * CMD_DESC_FIXED indicates a fixed length. Otherwise, the command has
131 	 * a length mask. All command entries in a command table must include
132 	 * length information.
133 	 */
134 	union {
135 		u32 fixed;
136 		u32 mask;
137 	} length;
138 
139 	/*
140 	 * Describes where to find a register address in the command to check
141 	 * against the ring's register whitelist. Only valid if flags has the
142 	 * CMD_DESC_REGISTER bit set.
143 	 *
144 	 * A non-zero step value implies that the command may access multiple
145 	 * registers in sequence (e.g. LRI), in that case step gives the
146 	 * distance in dwords between individual offset fields.
147 	 */
148 	struct {
149 		u32 offset;
150 		u32 mask;
151 		u32 step;
152 	} reg;
153 
154 #define MAX_CMD_DESC_BITMASKS 3
155 	/*
156 	 * Describes command checks where a particular dword is masked and
157 	 * compared against an expected value. If the command does not match
158 	 * the expected value, the parser rejects it. Only valid if flags has
159 	 * the CMD_DESC_BITMASK bit set. Only entries where mask is non-zero
160 	 * are valid.
161 	 *
162 	 * If the check specifies a non-zero condition_mask then the parser
163 	 * only performs the check when the bits specified by condition_mask
164 	 * are non-zero.
165 	 */
166 	struct {
167 		u32 offset;
168 		u32 mask;
169 		u32 expected;
170 		u32 condition_offset;
171 		u32 condition_mask;
172 	} bits[MAX_CMD_DESC_BITMASKS];
173 };
174 
175 /*
176  * A table of commands requiring special handling by the command parser.
177  *
178  * Each engine has an array of tables. Each table consists of an array of
179  * command descriptors, which must be sorted with command opcodes in
180  * ascending order.
181  */
182 struct drm_i915_cmd_table {
183 	const struct drm_i915_cmd_descriptor *table;
184 	int count;
185 };
186 
187 #define STD_MI_OPCODE_SHIFT  (32 - 9)
188 #define STD_3D_OPCODE_SHIFT  (32 - 16)
189 #define STD_2D_OPCODE_SHIFT  (32 - 10)
190 #define STD_MFX_OPCODE_SHIFT (32 - 16)
191 #define MIN_OPCODE_SHIFT 16
192 
193 #define CMD(op, opm, f, lm, fl, ...)				\
194 	{							\
195 		.flags = (fl) | ((f) ? CMD_DESC_FIXED : 0),	\
196 		.cmd = { (op), ~0u << (opm) },			\
197 		.length = { (lm) },				\
198 		__VA_ARGS__					\
199 	}
200 
201 /* Convenience macros to compress the tables */
202 #define SMI STD_MI_OPCODE_SHIFT
203 #define S3D STD_3D_OPCODE_SHIFT
204 #define S2D STD_2D_OPCODE_SHIFT
205 #define SMFX STD_MFX_OPCODE_SHIFT
206 #define F true
207 #define S CMD_DESC_SKIP
208 #define R CMD_DESC_REJECT
209 #define W CMD_DESC_REGISTER
210 #define B CMD_DESC_BITMASK
211 #define M CMD_DESC_MASTER
212 
213 /*            Command                          Mask   Fixed Len   Action
214 	      ---------------------------------------------------------- */
215 static const struct drm_i915_cmd_descriptor common_cmds[] = {
216 	CMD(  MI_NOOP,                          SMI,    F,  1,      S  ),
217 	CMD(  MI_USER_INTERRUPT,                SMI,    F,  1,      R  ),
218 	CMD(  MI_WAIT_FOR_EVENT,                SMI,    F,  1,      M  ),
219 	CMD(  MI_ARB_CHECK,                     SMI,    F,  1,      S  ),
220 	CMD(  MI_REPORT_HEAD,                   SMI,    F,  1,      S  ),
221 	CMD(  MI_SUSPEND_FLUSH,                 SMI,    F,  1,      S  ),
222 	CMD(  MI_SEMAPHORE_MBOX,                SMI,   !F,  0xFF,   R  ),
223 	CMD(  MI_STORE_DWORD_INDEX,             SMI,   !F,  0xFF,   R  ),
224 	CMD(  MI_LOAD_REGISTER_IMM(1),          SMI,   !F,  0xFF,   W,
225 	      .reg = { .offset = 1, .mask = 0x007FFFFC, .step = 2 }    ),
226 	CMD(  MI_STORE_REGISTER_MEM,            SMI,    F,  3,     W | B,
227 	      .reg = { .offset = 1, .mask = 0x007FFFFC },
228 	      .bits = {{
229 			.offset = 0,
230 			.mask = MI_GLOBAL_GTT,
231 			.expected = 0,
232 	      }},						       ),
233 	CMD(  MI_LOAD_REGISTER_MEM,             SMI,    F,  3,     W | B,
234 	      .reg = { .offset = 1, .mask = 0x007FFFFC },
235 	      .bits = {{
236 			.offset = 0,
237 			.mask = MI_GLOBAL_GTT,
238 			.expected = 0,
239 	      }},						       ),
240 	/*
241 	 * MI_BATCH_BUFFER_START requires some special handling. It's not
242 	 * really a 'skip' action but it doesn't seem like it's worth adding
243 	 * a new action. See i915_parse_cmds().
244 	 */
245 	CMD(  MI_BATCH_BUFFER_START,            SMI,   !F,  0xFF,   S  ),
246 };
247 
248 static const struct drm_i915_cmd_descriptor render_cmds[] = {
249 	CMD(  MI_FLUSH,                         SMI,    F,  1,      S  ),
250 	CMD(  MI_ARB_ON_OFF,                    SMI,    F,  1,      R  ),
251 	CMD(  MI_PREDICATE,                     SMI,    F,  1,      S  ),
252 	CMD(  MI_TOPOLOGY_FILTER,               SMI,    F,  1,      S  ),
253 	CMD(  MI_SET_APPID,                     SMI,    F,  1,      S  ),
254 	CMD(  MI_DISPLAY_FLIP,                  SMI,   !F,  0xFF,   R  ),
255 	CMD(  MI_SET_CONTEXT,                   SMI,   !F,  0xFF,   R  ),
256 	CMD(  MI_URB_CLEAR,                     SMI,   !F,  0xFF,   S  ),
257 	CMD(  MI_STORE_DWORD_IMM,               SMI,   !F,  0x3F,   B,
258 	      .bits = {{
259 			.offset = 0,
260 			.mask = MI_GLOBAL_GTT,
261 			.expected = 0,
262 	      }},						       ),
263 	CMD(  MI_UPDATE_GTT,                    SMI,   !F,  0xFF,   R  ),
264 	CMD(  MI_CLFLUSH,                       SMI,   !F,  0x3FF,  B,
265 	      .bits = {{
266 			.offset = 0,
267 			.mask = MI_GLOBAL_GTT,
268 			.expected = 0,
269 	      }},						       ),
270 	CMD(  MI_REPORT_PERF_COUNT,             SMI,   !F,  0x3F,   B,
271 	      .bits = {{
272 			.offset = 1,
273 			.mask = MI_REPORT_PERF_COUNT_GGTT,
274 			.expected = 0,
275 	      }},						       ),
276 	CMD(  MI_CONDITIONAL_BATCH_BUFFER_END,  SMI,   !F,  0xFF,   B,
277 	      .bits = {{
278 			.offset = 0,
279 			.mask = MI_GLOBAL_GTT,
280 			.expected = 0,
281 	      }},						       ),
282 	CMD(  GFX_OP_3DSTATE_VF_STATISTICS,     S3D,    F,  1,      S  ),
283 	CMD(  PIPELINE_SELECT,                  S3D,    F,  1,      S  ),
284 	CMD(  MEDIA_VFE_STATE,			S3D,   !F,  0xFFFF, B,
285 	      .bits = {{
286 			.offset = 2,
287 			.mask = MEDIA_VFE_STATE_MMIO_ACCESS_MASK,
288 			.expected = 0,
289 	      }},						       ),
290 	CMD(  GPGPU_OBJECT,                     S3D,   !F,  0xFF,   S  ),
291 	CMD(  GPGPU_WALKER,                     S3D,   !F,  0xFF,   S  ),
292 	CMD(  GFX_OP_3DSTATE_SO_DECL_LIST,      S3D,   !F,  0x1FF,  S  ),
293 	CMD(  GFX_OP_PIPE_CONTROL(5),           S3D,   !F,  0xFF,   B,
294 	      .bits = {{
295 			.offset = 1,
296 			.mask = (PIPE_CONTROL_MMIO_WRITE | PIPE_CONTROL_NOTIFY),
297 			.expected = 0,
298 	      },
299 	      {
300 			.offset = 1,
301 		        .mask = (PIPE_CONTROL_GLOBAL_GTT_IVB |
302 				 PIPE_CONTROL_STORE_DATA_INDEX),
303 			.expected = 0,
304 			.condition_offset = 1,
305 			.condition_mask = PIPE_CONTROL_POST_SYNC_OP_MASK,
306 	      }},						       ),
307 };
308 
309 static const struct drm_i915_cmd_descriptor hsw_render_cmds[] = {
310 	CMD(  MI_SET_PREDICATE,                 SMI,    F,  1,      S  ),
311 	CMD(  MI_RS_CONTROL,                    SMI,    F,  1,      S  ),
312 	CMD(  MI_URB_ATOMIC_ALLOC,              SMI,    F,  1,      S  ),
313 	CMD(  MI_SET_APPID,                     SMI,    F,  1,      S  ),
314 	CMD(  MI_RS_CONTEXT,                    SMI,    F,  1,      S  ),
315 	CMD(  MI_LOAD_SCAN_LINES_INCL,          SMI,   !F,  0x3F,   M  ),
316 	CMD(  MI_LOAD_SCAN_LINES_EXCL,          SMI,   !F,  0x3F,   R  ),
317 	CMD(  MI_LOAD_REGISTER_REG,             SMI,   !F,  0xFF,   W,
318 	      .reg = { .offset = 1, .mask = 0x007FFFFC, .step = 1 }    ),
319 	CMD(  MI_RS_STORE_DATA_IMM,             SMI,   !F,  0xFF,   S  ),
320 	CMD(  MI_LOAD_URB_MEM,                  SMI,   !F,  0xFF,   S  ),
321 	CMD(  MI_STORE_URB_MEM,                 SMI,   !F,  0xFF,   S  ),
322 	CMD(  GFX_OP_3DSTATE_DX9_CONSTANTF_VS,  S3D,   !F,  0x7FF,  S  ),
323 	CMD(  GFX_OP_3DSTATE_DX9_CONSTANTF_PS,  S3D,   !F,  0x7FF,  S  ),
324 
325 	CMD(  GFX_OP_3DSTATE_BINDING_TABLE_EDIT_VS,  S3D,   !F,  0x1FF,  S  ),
326 	CMD(  GFX_OP_3DSTATE_BINDING_TABLE_EDIT_GS,  S3D,   !F,  0x1FF,  S  ),
327 	CMD(  GFX_OP_3DSTATE_BINDING_TABLE_EDIT_HS,  S3D,   !F,  0x1FF,  S  ),
328 	CMD(  GFX_OP_3DSTATE_BINDING_TABLE_EDIT_DS,  S3D,   !F,  0x1FF,  S  ),
329 	CMD(  GFX_OP_3DSTATE_BINDING_TABLE_EDIT_PS,  S3D,   !F,  0x1FF,  S  ),
330 };
331 
332 static const struct drm_i915_cmd_descriptor video_cmds[] = {
333 	CMD(  MI_ARB_ON_OFF,                    SMI,    F,  1,      R  ),
334 	CMD(  MI_SET_APPID,                     SMI,    F,  1,      S  ),
335 	CMD(  MI_STORE_DWORD_IMM,               SMI,   !F,  0xFF,   B,
336 	      .bits = {{
337 			.offset = 0,
338 			.mask = MI_GLOBAL_GTT,
339 			.expected = 0,
340 	      }},						       ),
341 	CMD(  MI_UPDATE_GTT,                    SMI,   !F,  0x3F,   R  ),
342 	CMD(  MI_FLUSH_DW,                      SMI,   !F,  0x3F,   B,
343 	      .bits = {{
344 			.offset = 0,
345 			.mask = MI_FLUSH_DW_NOTIFY,
346 			.expected = 0,
347 	      },
348 	      {
349 			.offset = 1,
350 			.mask = MI_FLUSH_DW_USE_GTT,
351 			.expected = 0,
352 			.condition_offset = 0,
353 			.condition_mask = MI_FLUSH_DW_OP_MASK,
354 	      },
355 	      {
356 			.offset = 0,
357 			.mask = MI_FLUSH_DW_STORE_INDEX,
358 			.expected = 0,
359 			.condition_offset = 0,
360 			.condition_mask = MI_FLUSH_DW_OP_MASK,
361 	      }},						       ),
362 	CMD(  MI_CONDITIONAL_BATCH_BUFFER_END,  SMI,   !F,  0xFF,   B,
363 	      .bits = {{
364 			.offset = 0,
365 			.mask = MI_GLOBAL_GTT,
366 			.expected = 0,
367 	      }},						       ),
368 	/*
369 	 * MFX_WAIT doesn't fit the way we handle length for most commands.
370 	 * It has a length field but it uses a non-standard length bias.
371 	 * It is always 1 dword though, so just treat it as fixed length.
372 	 */
373 	CMD(  MFX_WAIT,                         SMFX,   F,  1,      S  ),
374 };
375 
376 static const struct drm_i915_cmd_descriptor vecs_cmds[] = {
377 	CMD(  MI_ARB_ON_OFF,                    SMI,    F,  1,      R  ),
378 	CMD(  MI_SET_APPID,                     SMI,    F,  1,      S  ),
379 	CMD(  MI_STORE_DWORD_IMM,               SMI,   !F,  0xFF,   B,
380 	      .bits = {{
381 			.offset = 0,
382 			.mask = MI_GLOBAL_GTT,
383 			.expected = 0,
384 	      }},						       ),
385 	CMD(  MI_UPDATE_GTT,                    SMI,   !F,  0x3F,   R  ),
386 	CMD(  MI_FLUSH_DW,                      SMI,   !F,  0x3F,   B,
387 	      .bits = {{
388 			.offset = 0,
389 			.mask = MI_FLUSH_DW_NOTIFY,
390 			.expected = 0,
391 	      },
392 	      {
393 			.offset = 1,
394 			.mask = MI_FLUSH_DW_USE_GTT,
395 			.expected = 0,
396 			.condition_offset = 0,
397 			.condition_mask = MI_FLUSH_DW_OP_MASK,
398 	      },
399 	      {
400 			.offset = 0,
401 			.mask = MI_FLUSH_DW_STORE_INDEX,
402 			.expected = 0,
403 			.condition_offset = 0,
404 			.condition_mask = MI_FLUSH_DW_OP_MASK,
405 	      }},						       ),
406 	CMD(  MI_CONDITIONAL_BATCH_BUFFER_END,  SMI,   !F,  0xFF,   B,
407 	      .bits = {{
408 			.offset = 0,
409 			.mask = MI_GLOBAL_GTT,
410 			.expected = 0,
411 	      }},						       ),
412 };
413 
414 static const struct drm_i915_cmd_descriptor blt_cmds[] = {
415 	CMD(  MI_DISPLAY_FLIP,                  SMI,   !F,  0xFF,   R  ),
416 	CMD(  MI_STORE_DWORD_IMM,               SMI,   !F,  0x3FF,  B,
417 	      .bits = {{
418 			.offset = 0,
419 			.mask = MI_GLOBAL_GTT,
420 			.expected = 0,
421 	      }},						       ),
422 	CMD(  MI_UPDATE_GTT,                    SMI,   !F,  0x3F,   R  ),
423 	CMD(  MI_FLUSH_DW,                      SMI,   !F,  0x3F,   B,
424 	      .bits = {{
425 			.offset = 0,
426 			.mask = MI_FLUSH_DW_NOTIFY,
427 			.expected = 0,
428 	      },
429 	      {
430 			.offset = 1,
431 			.mask = MI_FLUSH_DW_USE_GTT,
432 			.expected = 0,
433 			.condition_offset = 0,
434 			.condition_mask = MI_FLUSH_DW_OP_MASK,
435 	      },
436 	      {
437 			.offset = 0,
438 			.mask = MI_FLUSH_DW_STORE_INDEX,
439 			.expected = 0,
440 			.condition_offset = 0,
441 			.condition_mask = MI_FLUSH_DW_OP_MASK,
442 	      }},						       ),
443 	CMD(  COLOR_BLT,                        S2D,   !F,  0x3F,   S  ),
444 	CMD(  SRC_COPY_BLT,                     S2D,   !F,  0x3F,   S  ),
445 };
446 
447 static const struct drm_i915_cmd_descriptor hsw_blt_cmds[] = {
448 	CMD(  MI_LOAD_SCAN_LINES_INCL,          SMI,   !F,  0x3F,   M  ),
449 	CMD(  MI_LOAD_SCAN_LINES_EXCL,          SMI,   !F,  0x3F,   R  ),
450 };
451 
452 static const struct drm_i915_cmd_descriptor noop_desc =
453 	CMD(MI_NOOP, SMI, F, 1, S);
454 
455 #undef CMD
456 #undef SMI
457 #undef S3D
458 #undef S2D
459 #undef SMFX
460 #undef F
461 #undef S
462 #undef R
463 #undef W
464 #undef B
465 #undef M
466 
467 static const struct drm_i915_cmd_table gen7_render_cmds[] = {
468 	{ common_cmds, ARRAY_SIZE(common_cmds) },
469 	{ render_cmds, ARRAY_SIZE(render_cmds) },
470 };
471 
472 static const struct drm_i915_cmd_table hsw_render_ring_cmds[] = {
473 	{ common_cmds, ARRAY_SIZE(common_cmds) },
474 	{ render_cmds, ARRAY_SIZE(render_cmds) },
475 	{ hsw_render_cmds, ARRAY_SIZE(hsw_render_cmds) },
476 };
477 
478 static const struct drm_i915_cmd_table gen7_video_cmds[] = {
479 	{ common_cmds, ARRAY_SIZE(common_cmds) },
480 	{ video_cmds, ARRAY_SIZE(video_cmds) },
481 };
482 
483 static const struct drm_i915_cmd_table hsw_vebox_cmds[] = {
484 	{ common_cmds, ARRAY_SIZE(common_cmds) },
485 	{ vecs_cmds, ARRAY_SIZE(vecs_cmds) },
486 };
487 
488 static const struct drm_i915_cmd_table gen7_blt_cmds[] = {
489 	{ common_cmds, ARRAY_SIZE(common_cmds) },
490 	{ blt_cmds, ARRAY_SIZE(blt_cmds) },
491 };
492 
493 static const struct drm_i915_cmd_table hsw_blt_ring_cmds[] = {
494 	{ common_cmds, ARRAY_SIZE(common_cmds) },
495 	{ blt_cmds, ARRAY_SIZE(blt_cmds) },
496 	{ hsw_blt_cmds, ARRAY_SIZE(hsw_blt_cmds) },
497 };
498 
499 /*
500  * Register whitelists, sorted by increasing register offset.
501  */
502 
503 /*
504  * An individual whitelist entry granting access to register addr.  If
505  * mask is non-zero the argument of immediate register writes will be
506  * AND-ed with mask, and the command will be rejected if the result
507  * doesn't match value.
508  *
509  * Registers with non-zero mask are only allowed to be written using
510  * LRI.
511  */
512 struct drm_i915_reg_descriptor {
513 	i915_reg_t addr;
514 	u32 mask;
515 	u32 value;
516 };
517 
518 /* Convenience macro for adding 32-bit registers. */
519 #define REG32(_reg, ...) \
520 	{ .addr = (_reg), __VA_ARGS__ }
521 
522 /*
523  * Convenience macro for adding 64-bit registers.
524  *
525  * Some registers that userspace accesses are 64 bits. The register
526  * access commands only allow 32-bit accesses. Hence, we have to include
527  * entries for both halves of the 64-bit registers.
528  */
529 #define REG64(_reg) \
530 	{ .addr = _reg }, \
531 	{ .addr = _reg ## _UDW }
532 
533 #define REG64_IDX(_reg, idx) \
534 	{ .addr = _reg(idx) }, \
535 	{ .addr = _reg ## _UDW(idx) }
536 
537 static const struct drm_i915_reg_descriptor gen7_render_regs[] = {
538 	REG64(GPGPU_THREADS_DISPATCHED),
539 	REG64(HS_INVOCATION_COUNT),
540 	REG64(DS_INVOCATION_COUNT),
541 	REG64(IA_VERTICES_COUNT),
542 	REG64(IA_PRIMITIVES_COUNT),
543 	REG64(VS_INVOCATION_COUNT),
544 	REG64(GS_INVOCATION_COUNT),
545 	REG64(GS_PRIMITIVES_COUNT),
546 	REG64(CL_INVOCATION_COUNT),
547 	REG64(CL_PRIMITIVES_COUNT),
548 	REG64(PS_INVOCATION_COUNT),
549 	REG64(PS_DEPTH_COUNT),
550 	REG64_IDX(RING_TIMESTAMP, RENDER_RING_BASE),
551 	REG64(MI_PREDICATE_SRC0),
552 	REG64(MI_PREDICATE_SRC1),
553 	REG32(GEN7_3DPRIM_END_OFFSET),
554 	REG32(GEN7_3DPRIM_START_VERTEX),
555 	REG32(GEN7_3DPRIM_VERTEX_COUNT),
556 	REG32(GEN7_3DPRIM_INSTANCE_COUNT),
557 	REG32(GEN7_3DPRIM_START_INSTANCE),
558 	REG32(GEN7_3DPRIM_BASE_VERTEX),
559 	REG32(GEN7_GPGPU_DISPATCHDIMX),
560 	REG32(GEN7_GPGPU_DISPATCHDIMY),
561 	REG32(GEN7_GPGPU_DISPATCHDIMZ),
562 	REG64_IDX(RING_TIMESTAMP, BSD_RING_BASE),
563 	REG64_IDX(GEN7_SO_NUM_PRIMS_WRITTEN, 0),
564 	REG64_IDX(GEN7_SO_NUM_PRIMS_WRITTEN, 1),
565 	REG64_IDX(GEN7_SO_NUM_PRIMS_WRITTEN, 2),
566 	REG64_IDX(GEN7_SO_NUM_PRIMS_WRITTEN, 3),
567 	REG64_IDX(GEN7_SO_PRIM_STORAGE_NEEDED, 0),
568 	REG64_IDX(GEN7_SO_PRIM_STORAGE_NEEDED, 1),
569 	REG64_IDX(GEN7_SO_PRIM_STORAGE_NEEDED, 2),
570 	REG64_IDX(GEN7_SO_PRIM_STORAGE_NEEDED, 3),
571 	REG32(GEN7_SO_WRITE_OFFSET(0)),
572 	REG32(GEN7_SO_WRITE_OFFSET(1)),
573 	REG32(GEN7_SO_WRITE_OFFSET(2)),
574 	REG32(GEN7_SO_WRITE_OFFSET(3)),
575 	REG32(GEN7_L3SQCREG1),
576 	REG32(GEN7_L3CNTLREG2),
577 	REG32(GEN7_L3CNTLREG3),
578 	REG64_IDX(RING_TIMESTAMP, BLT_RING_BASE),
579 };
580 
581 static const struct drm_i915_reg_descriptor hsw_render_regs[] = {
582 	REG64_IDX(HSW_CS_GPR, 0),
583 	REG64_IDX(HSW_CS_GPR, 1),
584 	REG64_IDX(HSW_CS_GPR, 2),
585 	REG64_IDX(HSW_CS_GPR, 3),
586 	REG64_IDX(HSW_CS_GPR, 4),
587 	REG64_IDX(HSW_CS_GPR, 5),
588 	REG64_IDX(HSW_CS_GPR, 6),
589 	REG64_IDX(HSW_CS_GPR, 7),
590 	REG64_IDX(HSW_CS_GPR, 8),
591 	REG64_IDX(HSW_CS_GPR, 9),
592 	REG64_IDX(HSW_CS_GPR, 10),
593 	REG64_IDX(HSW_CS_GPR, 11),
594 	REG64_IDX(HSW_CS_GPR, 12),
595 	REG64_IDX(HSW_CS_GPR, 13),
596 	REG64_IDX(HSW_CS_GPR, 14),
597 	REG64_IDX(HSW_CS_GPR, 15),
598 	REG32(HSW_SCRATCH1,
599 	      .mask = ~HSW_SCRATCH1_L3_DATA_ATOMICS_DISABLE,
600 	      .value = 0),
601 	REG32(HSW_ROW_CHICKEN3,
602 	      .mask = ~(HSW_ROW_CHICKEN3_L3_GLOBAL_ATOMICS_DISABLE << 16 |
603                         HSW_ROW_CHICKEN3_L3_GLOBAL_ATOMICS_DISABLE),
604 	      .value = 0),
605 };
606 
607 static const struct drm_i915_reg_descriptor gen7_blt_regs[] = {
608 	REG64_IDX(RING_TIMESTAMP, RENDER_RING_BASE),
609 	REG64_IDX(RING_TIMESTAMP, BSD_RING_BASE),
610 	REG32(BCS_SWCTRL),
611 	REG64_IDX(RING_TIMESTAMP, BLT_RING_BASE),
612 };
613 
614 static const struct drm_i915_reg_descriptor ivb_master_regs[] = {
615 	REG32(FORCEWAKE_MT),
616 	REG32(DERRMR),
617 	REG32(GEN7_PIPE_DE_LOAD_SL(PIPE_A)),
618 	REG32(GEN7_PIPE_DE_LOAD_SL(PIPE_B)),
619 	REG32(GEN7_PIPE_DE_LOAD_SL(PIPE_C)),
620 };
621 
622 static const struct drm_i915_reg_descriptor hsw_master_regs[] = {
623 	REG32(FORCEWAKE_MT),
624 	REG32(DERRMR),
625 };
626 
627 #undef REG64
628 #undef REG32
629 
630 struct drm_i915_reg_table {
631 	const struct drm_i915_reg_descriptor *regs;
632 	int num_regs;
633 	bool master;
634 };
635 
636 static const struct drm_i915_reg_table ivb_render_reg_tables[] = {
637 	{ gen7_render_regs, ARRAY_SIZE(gen7_render_regs), false },
638 	{ ivb_master_regs, ARRAY_SIZE(ivb_master_regs), true },
639 };
640 
641 static const struct drm_i915_reg_table ivb_blt_reg_tables[] = {
642 	{ gen7_blt_regs, ARRAY_SIZE(gen7_blt_regs), false },
643 	{ ivb_master_regs, ARRAY_SIZE(ivb_master_regs), true },
644 };
645 
646 static const struct drm_i915_reg_table hsw_render_reg_tables[] = {
647 	{ gen7_render_regs, ARRAY_SIZE(gen7_render_regs), false },
648 	{ hsw_render_regs, ARRAY_SIZE(hsw_render_regs), false },
649 	{ hsw_master_regs, ARRAY_SIZE(hsw_master_regs), true },
650 };
651 
652 static const struct drm_i915_reg_table hsw_blt_reg_tables[] = {
653 	{ gen7_blt_regs, ARRAY_SIZE(gen7_blt_regs), false },
654 	{ hsw_master_regs, ARRAY_SIZE(hsw_master_regs), true },
655 };
656 
657 static u32 gen7_render_get_cmd_length_mask(u32 cmd_header)
658 {
659 	u32 client = cmd_header >> INSTR_CLIENT_SHIFT;
660 	u32 subclient =
661 		(cmd_header & INSTR_SUBCLIENT_MASK) >> INSTR_SUBCLIENT_SHIFT;
662 
663 	if (client == INSTR_MI_CLIENT)
664 		return 0x3F;
665 	else if (client == INSTR_RC_CLIENT) {
666 		if (subclient == INSTR_MEDIA_SUBCLIENT)
667 			return 0xFFFF;
668 		else
669 			return 0xFF;
670 	}
671 
672 	DRM_DEBUG_DRIVER("CMD: Abnormal rcs cmd length! 0x%08X\n", cmd_header);
673 	return 0;
674 }
675 
676 static u32 gen7_bsd_get_cmd_length_mask(u32 cmd_header)
677 {
678 	u32 client = cmd_header >> INSTR_CLIENT_SHIFT;
679 	u32 subclient =
680 		(cmd_header & INSTR_SUBCLIENT_MASK) >> INSTR_SUBCLIENT_SHIFT;
681 	u32 op = (cmd_header & INSTR_26_TO_24_MASK) >> INSTR_26_TO_24_SHIFT;
682 
683 	if (client == INSTR_MI_CLIENT)
684 		return 0x3F;
685 	else if (client == INSTR_RC_CLIENT) {
686 		if (subclient == INSTR_MEDIA_SUBCLIENT) {
687 			if (op == 6)
688 				return 0xFFFF;
689 			else
690 				return 0xFFF;
691 		} else
692 			return 0xFF;
693 	}
694 
695 	DRM_DEBUG_DRIVER("CMD: Abnormal bsd cmd length! 0x%08X\n", cmd_header);
696 	return 0;
697 }
698 
699 static u32 gen7_blt_get_cmd_length_mask(u32 cmd_header)
700 {
701 	u32 client = cmd_header >> INSTR_CLIENT_SHIFT;
702 
703 	if (client == INSTR_MI_CLIENT)
704 		return 0x3F;
705 	else if (client == INSTR_BC_CLIENT)
706 		return 0xFF;
707 
708 	DRM_DEBUG_DRIVER("CMD: Abnormal blt cmd length! 0x%08X\n", cmd_header);
709 	return 0;
710 }
711 
712 static bool validate_cmds_sorted(const struct intel_engine_cs *engine,
713 				 const struct drm_i915_cmd_table *cmd_tables,
714 				 int cmd_table_count)
715 {
716 	int i;
717 	bool ret = true;
718 
719 	if (!cmd_tables || cmd_table_count == 0)
720 		return true;
721 
722 	for (i = 0; i < cmd_table_count; i++) {
723 		const struct drm_i915_cmd_table *table = &cmd_tables[i];
724 		u32 previous = 0;
725 		int j;
726 
727 		for (j = 0; j < table->count; j++) {
728 			const struct drm_i915_cmd_descriptor *desc =
729 				&table->table[j];
730 			u32 curr = desc->cmd.value & desc->cmd.mask;
731 
732 			if (curr < previous) {
733 				DRM_ERROR("CMD: %s [%d] command table not sorted: "
734 					  "table=%d entry=%d cmd=0x%08X prev=0x%08X\n",
735 					  engine->name, engine->id,
736 					  i, j, curr, previous);
737 				ret = false;
738 			}
739 
740 			previous = curr;
741 		}
742 	}
743 
744 	return ret;
745 }
746 
747 static bool check_sorted(const struct intel_engine_cs *engine,
748 			 const struct drm_i915_reg_descriptor *reg_table,
749 			 int reg_count)
750 {
751 	int i;
752 	u32 previous = 0;
753 	bool ret = true;
754 
755 	for (i = 0; i < reg_count; i++) {
756 		u32 curr = i915_mmio_reg_offset(reg_table[i].addr);
757 
758 		if (curr < previous) {
759 			DRM_ERROR("CMD: %s [%d] register table not sorted: "
760 				  "entry=%d reg=0x%08X prev=0x%08X\n",
761 				  engine->name, engine->id,
762 				  i, curr, previous);
763 			ret = false;
764 		}
765 
766 		previous = curr;
767 	}
768 
769 	return ret;
770 }
771 
772 static bool validate_regs_sorted(struct intel_engine_cs *engine)
773 {
774 	int i;
775 	const struct drm_i915_reg_table *table;
776 
777 	for (i = 0; i < engine->reg_table_count; i++) {
778 		table = &engine->reg_tables[i];
779 		if (!check_sorted(engine, table->regs, table->num_regs))
780 			return false;
781 	}
782 
783 	return true;
784 }
785 
786 struct cmd_node {
787 	const struct drm_i915_cmd_descriptor *desc;
788 	struct hlist_node node;
789 };
790 
791 /*
792  * Different command ranges have different numbers of bits for the opcode. For
793  * example, MI commands use bits 31:23 while 3D commands use bits 31:16. The
794  * problem is that, for example, MI commands use bits 22:16 for other fields
795  * such as GGTT vs PPGTT bits. If we include those bits in the mask then when
796  * we mask a command from a batch it could hash to the wrong bucket due to
797  * non-opcode bits being set. But if we don't include those bits, some 3D
798  * commands may hash to the same bucket due to not including opcode bits that
799  * make the command unique. For now, we will risk hashing to the same bucket.
800  */
801 static inline u32 cmd_header_key(u32 x)
802 {
803 	switch (x >> INSTR_CLIENT_SHIFT) {
804 	default:
805 	case INSTR_MI_CLIENT:
806 		return x >> STD_MI_OPCODE_SHIFT;
807 	case INSTR_RC_CLIENT:
808 		return x >> STD_3D_OPCODE_SHIFT;
809 	case INSTR_BC_CLIENT:
810 		return x >> STD_2D_OPCODE_SHIFT;
811 	}
812 }
813 
814 static int init_hash_table(struct intel_engine_cs *engine,
815 			   const struct drm_i915_cmd_table *cmd_tables,
816 			   int cmd_table_count)
817 {
818 	int i, j;
819 
820 	hash_init(engine->cmd_hash);
821 
822 	for (i = 0; i < cmd_table_count; i++) {
823 		const struct drm_i915_cmd_table *table = &cmd_tables[i];
824 
825 		for (j = 0; j < table->count; j++) {
826 			const struct drm_i915_cmd_descriptor *desc =
827 				&table->table[j];
828 			struct cmd_node *desc_node =
829 				kmalloc(sizeof(*desc_node), GFP_KERNEL);
830 
831 			if (!desc_node)
832 				return -ENOMEM;
833 
834 			desc_node->desc = desc;
835 			hash_add(engine->cmd_hash, &desc_node->node,
836 				 cmd_header_key(desc->cmd.value));
837 		}
838 	}
839 
840 	return 0;
841 }
842 
843 static void fini_hash_table(struct intel_engine_cs *engine)
844 {
845 	struct hlist_node *tmp;
846 	struct cmd_node *desc_node;
847 	int i;
848 
849 	hash_for_each_safe(engine->cmd_hash, i, tmp, desc_node, node) {
850 		hash_del(&desc_node->node);
851 		kfree(desc_node);
852 	}
853 }
854 
855 /**
856  * intel_engine_init_cmd_parser() - set cmd parser related fields for an engine
857  * @engine: the engine to initialize
858  *
859  * Optionally initializes fields related to batch buffer command parsing in the
860  * struct intel_engine_cs based on whether the platform requires software
861  * command parsing.
862  */
863 void intel_engine_init_cmd_parser(struct intel_engine_cs *engine)
864 {
865 	const struct drm_i915_cmd_table *cmd_tables;
866 	int cmd_table_count;
867 	int ret;
868 
869 	if (!IS_GEN(engine->i915, 7))
870 		return;
871 
872 	switch (engine->class) {
873 	case RENDER_CLASS:
874 		if (IS_HASWELL(engine->i915)) {
875 			cmd_tables = hsw_render_ring_cmds;
876 			cmd_table_count =
877 				ARRAY_SIZE(hsw_render_ring_cmds);
878 		} else {
879 			cmd_tables = gen7_render_cmds;
880 			cmd_table_count = ARRAY_SIZE(gen7_render_cmds);
881 		}
882 
883 		if (IS_HASWELL(engine->i915)) {
884 			engine->reg_tables = hsw_render_reg_tables;
885 			engine->reg_table_count = ARRAY_SIZE(hsw_render_reg_tables);
886 		} else {
887 			engine->reg_tables = ivb_render_reg_tables;
888 			engine->reg_table_count = ARRAY_SIZE(ivb_render_reg_tables);
889 		}
890 
891 		engine->get_cmd_length_mask = gen7_render_get_cmd_length_mask;
892 		break;
893 	case VIDEO_DECODE_CLASS:
894 		cmd_tables = gen7_video_cmds;
895 		cmd_table_count = ARRAY_SIZE(gen7_video_cmds);
896 		engine->get_cmd_length_mask = gen7_bsd_get_cmd_length_mask;
897 		break;
898 	case COPY_ENGINE_CLASS:
899 		if (IS_HASWELL(engine->i915)) {
900 			cmd_tables = hsw_blt_ring_cmds;
901 			cmd_table_count = ARRAY_SIZE(hsw_blt_ring_cmds);
902 		} else {
903 			cmd_tables = gen7_blt_cmds;
904 			cmd_table_count = ARRAY_SIZE(gen7_blt_cmds);
905 		}
906 
907 		if (IS_HASWELL(engine->i915)) {
908 			engine->reg_tables = hsw_blt_reg_tables;
909 			engine->reg_table_count = ARRAY_SIZE(hsw_blt_reg_tables);
910 		} else {
911 			engine->reg_tables = ivb_blt_reg_tables;
912 			engine->reg_table_count = ARRAY_SIZE(ivb_blt_reg_tables);
913 		}
914 
915 		engine->get_cmd_length_mask = gen7_blt_get_cmd_length_mask;
916 		break;
917 	case VIDEO_ENHANCEMENT_CLASS:
918 		cmd_tables = hsw_vebox_cmds;
919 		cmd_table_count = ARRAY_SIZE(hsw_vebox_cmds);
920 		/* VECS can use the same length_mask function as VCS */
921 		engine->get_cmd_length_mask = gen7_bsd_get_cmd_length_mask;
922 		break;
923 	default:
924 		MISSING_CASE(engine->class);
925 		return;
926 	}
927 
928 	if (!validate_cmds_sorted(engine, cmd_tables, cmd_table_count)) {
929 		DRM_ERROR("%s: command descriptions are not sorted\n",
930 			  engine->name);
931 		return;
932 	}
933 	if (!validate_regs_sorted(engine)) {
934 		DRM_ERROR("%s: registers are not sorted\n", engine->name);
935 		return;
936 	}
937 
938 	ret = init_hash_table(engine, cmd_tables, cmd_table_count);
939 	if (ret) {
940 		DRM_ERROR("%s: initialised failed!\n", engine->name);
941 		fini_hash_table(engine);
942 		return;
943 	}
944 
945 	engine->flags |= I915_ENGINE_NEEDS_CMD_PARSER;
946 }
947 
948 /**
949  * intel_engine_cleanup_cmd_parser() - clean up cmd parser related fields
950  * @engine: the engine to clean up
951  *
952  * Releases any resources related to command parsing that may have been
953  * initialized for the specified engine.
954  */
955 void intel_engine_cleanup_cmd_parser(struct intel_engine_cs *engine)
956 {
957 	if (!intel_engine_needs_cmd_parser(engine))
958 		return;
959 
960 	fini_hash_table(engine);
961 }
962 
963 static const struct drm_i915_cmd_descriptor*
964 find_cmd_in_table(struct intel_engine_cs *engine,
965 		  u32 cmd_header)
966 {
967 	struct cmd_node *desc_node;
968 
969 	hash_for_each_possible(engine->cmd_hash, desc_node, node,
970 			       cmd_header_key(cmd_header)) {
971 		const struct drm_i915_cmd_descriptor *desc = desc_node->desc;
972 		if (((cmd_header ^ desc->cmd.value) & desc->cmd.mask) == 0)
973 			return desc;
974 	}
975 
976 	return NULL;
977 }
978 
979 /*
980  * Returns a pointer to a descriptor for the command specified by cmd_header.
981  *
982  * The caller must supply space for a default descriptor via the default_desc
983  * parameter. If no descriptor for the specified command exists in the engine's
984  * command parser tables, this function fills in default_desc based on the
985  * engine's default length encoding and returns default_desc.
986  */
987 static const struct drm_i915_cmd_descriptor*
988 find_cmd(struct intel_engine_cs *engine,
989 	 u32 cmd_header,
990 	 const struct drm_i915_cmd_descriptor *desc,
991 	 struct drm_i915_cmd_descriptor *default_desc)
992 {
993 	u32 mask;
994 
995 	if (((cmd_header ^ desc->cmd.value) & desc->cmd.mask) == 0)
996 		return desc;
997 
998 	desc = find_cmd_in_table(engine, cmd_header);
999 	if (desc)
1000 		return desc;
1001 
1002 	mask = engine->get_cmd_length_mask(cmd_header);
1003 	if (!mask)
1004 		return NULL;
1005 
1006 	default_desc->cmd.value = cmd_header;
1007 	default_desc->cmd.mask = ~0u << MIN_OPCODE_SHIFT;
1008 	default_desc->length.mask = mask;
1009 	default_desc->flags = CMD_DESC_SKIP;
1010 	return default_desc;
1011 }
1012 
1013 static const struct drm_i915_reg_descriptor *
1014 __find_reg(const struct drm_i915_reg_descriptor *table, int count, u32 addr)
1015 {
1016 	int start = 0, end = count;
1017 	while (start < end) {
1018 		int mid = start + (end - start) / 2;
1019 		int ret = addr - i915_mmio_reg_offset(table[mid].addr);
1020 		if (ret < 0)
1021 			end = mid;
1022 		else if (ret > 0)
1023 			start = mid + 1;
1024 		else
1025 			return &table[mid];
1026 	}
1027 	return NULL;
1028 }
1029 
1030 static const struct drm_i915_reg_descriptor *
1031 find_reg(const struct intel_engine_cs *engine, bool is_master, u32 addr)
1032 {
1033 	const struct drm_i915_reg_table *table = engine->reg_tables;
1034 	int count = engine->reg_table_count;
1035 
1036 	for (; count > 0; ++table, --count) {
1037 		if (!table->master || is_master) {
1038 			const struct drm_i915_reg_descriptor *reg;
1039 
1040 			reg = __find_reg(table->regs, table->num_regs, addr);
1041 			if (reg != NULL)
1042 				return reg;
1043 		}
1044 	}
1045 
1046 	return NULL;
1047 }
1048 
1049 /* Returns a vmap'd pointer to dst_obj, which the caller must unmap */
1050 static u32 *copy_batch(struct drm_i915_gem_object *dst_obj,
1051 		       struct drm_i915_gem_object *src_obj,
1052 		       u32 batch_start_offset,
1053 		       u32 batch_len,
1054 		       bool *needs_clflush_after)
1055 {
1056 	unsigned int src_needs_clflush;
1057 	unsigned int dst_needs_clflush;
1058 	void *dst, *src;
1059 	int ret;
1060 
1061 	ret = i915_gem_object_prepare_write(dst_obj, &dst_needs_clflush);
1062 	if (ret)
1063 		return ERR_PTR(ret);
1064 
1065 	dst = i915_gem_object_pin_map(dst_obj, I915_MAP_FORCE_WB);
1066 	i915_gem_object_finish_access(dst_obj);
1067 	if (IS_ERR(dst))
1068 		return dst;
1069 
1070 	ret = i915_gem_object_prepare_read(src_obj, &src_needs_clflush);
1071 	if (ret) {
1072 		i915_gem_object_unpin_map(dst_obj);
1073 		return ERR_PTR(ret);
1074 	}
1075 
1076 	src = ERR_PTR(-ENODEV);
1077 	if (src_needs_clflush &&
1078 	    i915_can_memcpy_from_wc(NULL, batch_start_offset, 0)) {
1079 		src = i915_gem_object_pin_map(src_obj, I915_MAP_WC);
1080 		if (!IS_ERR(src)) {
1081 			i915_memcpy_from_wc(dst,
1082 					    src + batch_start_offset,
1083 					    ALIGN(batch_len, 16));
1084 			i915_gem_object_unpin_map(src_obj);
1085 		}
1086 	}
1087 	if (IS_ERR(src)) {
1088 		void *ptr;
1089 		int offset, n;
1090 
1091 		offset = offset_in_page(batch_start_offset);
1092 
1093 		/* We can avoid clflushing partial cachelines before the write
1094 		 * if we only every write full cache-lines. Since we know that
1095 		 * both the source and destination are in multiples of
1096 		 * PAGE_SIZE, we can simply round up to the next cacheline.
1097 		 * We don't care about copying too much here as we only
1098 		 * validate up to the end of the batch.
1099 		 */
1100 		if (dst_needs_clflush & CLFLUSH_BEFORE)
1101 			batch_len = roundup(batch_len,
1102 					    boot_cpu_data.x86_clflush_size);
1103 
1104 		ptr = dst;
1105 		for (n = batch_start_offset >> PAGE_SHIFT; batch_len; n++) {
1106 			int len = min_t(int, batch_len, PAGE_SIZE - offset);
1107 
1108 			src = kmap_atomic(i915_gem_object_get_page(src_obj, n));
1109 			if (src_needs_clflush)
1110 				drm_clflush_virt_range(src + offset, len);
1111 			memcpy(ptr, src + offset, len);
1112 			kunmap_atomic(src);
1113 
1114 			ptr += len;
1115 			batch_len -= len;
1116 			offset = 0;
1117 		}
1118 	}
1119 
1120 	i915_gem_object_finish_access(src_obj);
1121 
1122 	/* dst_obj is returned with vmap pinned */
1123 	*needs_clflush_after = dst_needs_clflush & CLFLUSH_AFTER;
1124 
1125 	return dst;
1126 }
1127 
1128 static bool check_cmd(const struct intel_engine_cs *engine,
1129 		      const struct drm_i915_cmd_descriptor *desc,
1130 		      const u32 *cmd, u32 length,
1131 		      const bool is_master)
1132 {
1133 	if (desc->flags & CMD_DESC_SKIP)
1134 		return true;
1135 
1136 	if (desc->flags & CMD_DESC_REJECT) {
1137 		DRM_DEBUG_DRIVER("CMD: Rejected command: 0x%08X\n", *cmd);
1138 		return false;
1139 	}
1140 
1141 	if ((desc->flags & CMD_DESC_MASTER) && !is_master) {
1142 		DRM_DEBUG_DRIVER("CMD: Rejected master-only command: 0x%08X\n",
1143 				 *cmd);
1144 		return false;
1145 	}
1146 
1147 	if (desc->flags & CMD_DESC_REGISTER) {
1148 		/*
1149 		 * Get the distance between individual register offset
1150 		 * fields if the command can perform more than one
1151 		 * access at a time.
1152 		 */
1153 		const u32 step = desc->reg.step ? desc->reg.step : length;
1154 		u32 offset;
1155 
1156 		for (offset = desc->reg.offset; offset < length;
1157 		     offset += step) {
1158 			const u32 reg_addr = cmd[offset] & desc->reg.mask;
1159 			const struct drm_i915_reg_descriptor *reg =
1160 				find_reg(engine, is_master, reg_addr);
1161 
1162 			if (!reg) {
1163 				DRM_DEBUG_DRIVER("CMD: Rejected register 0x%08X in command: 0x%08X (%s)\n",
1164 						 reg_addr, *cmd, engine->name);
1165 				return false;
1166 			}
1167 
1168 			/*
1169 			 * Check the value written to the register against the
1170 			 * allowed mask/value pair given in the whitelist entry.
1171 			 */
1172 			if (reg->mask) {
1173 				if (desc->cmd.value == MI_LOAD_REGISTER_MEM) {
1174 					DRM_DEBUG_DRIVER("CMD: Rejected LRM to masked register 0x%08X\n",
1175 							 reg_addr);
1176 					return false;
1177 				}
1178 
1179 				if (desc->cmd.value == MI_LOAD_REGISTER_REG) {
1180 					DRM_DEBUG_DRIVER("CMD: Rejected LRR to masked register 0x%08X\n",
1181 							 reg_addr);
1182 					return false;
1183 				}
1184 
1185 				if (desc->cmd.value == MI_LOAD_REGISTER_IMM(1) &&
1186 				    (offset + 2 > length ||
1187 				     (cmd[offset + 1] & reg->mask) != reg->value)) {
1188 					DRM_DEBUG_DRIVER("CMD: Rejected LRI to masked register 0x%08X\n",
1189 							 reg_addr);
1190 					return false;
1191 				}
1192 			}
1193 		}
1194 	}
1195 
1196 	if (desc->flags & CMD_DESC_BITMASK) {
1197 		int i;
1198 
1199 		for (i = 0; i < MAX_CMD_DESC_BITMASKS; i++) {
1200 			u32 dword;
1201 
1202 			if (desc->bits[i].mask == 0)
1203 				break;
1204 
1205 			if (desc->bits[i].condition_mask != 0) {
1206 				u32 offset =
1207 					desc->bits[i].condition_offset;
1208 				u32 condition = cmd[offset] &
1209 					desc->bits[i].condition_mask;
1210 
1211 				if (condition == 0)
1212 					continue;
1213 			}
1214 
1215 			if (desc->bits[i].offset >= length) {
1216 				DRM_DEBUG_DRIVER("CMD: Rejected command 0x%08X, too short to check bitmask (%s)\n",
1217 						 *cmd, engine->name);
1218 				return false;
1219 			}
1220 
1221 			dword = cmd[desc->bits[i].offset] &
1222 				desc->bits[i].mask;
1223 
1224 			if (dword != desc->bits[i].expected) {
1225 				DRM_DEBUG_DRIVER("CMD: Rejected command 0x%08X for bitmask 0x%08X (exp=0x%08X act=0x%08X) (%s)\n",
1226 						 *cmd,
1227 						 desc->bits[i].mask,
1228 						 desc->bits[i].expected,
1229 						 dword, engine->name);
1230 				return false;
1231 			}
1232 		}
1233 	}
1234 
1235 	return true;
1236 }
1237 
1238 #define LENGTH_BIAS 2
1239 
1240 /**
1241  * i915_parse_cmds() - parse a submitted batch buffer for privilege violations
1242  * @engine: the engine on which the batch is to execute
1243  * @batch_obj: the batch buffer in question
1244  * @shadow_batch_obj: copy of the batch buffer in question
1245  * @batch_start_offset: byte offset in the batch at which execution starts
1246  * @batch_len: length of the commands in batch_obj
1247  * @is_master: is the submitting process the drm master?
1248  *
1249  * Parses the specified batch buffer looking for privilege violations as
1250  * described in the overview.
1251  *
1252  * Return: non-zero if the parser finds violations or otherwise fails; -EACCES
1253  * if the batch appears legal but should use hardware parsing
1254  */
1255 int intel_engine_cmd_parser(struct intel_engine_cs *engine,
1256 			    struct drm_i915_gem_object *batch_obj,
1257 			    struct drm_i915_gem_object *shadow_batch_obj,
1258 			    u32 batch_start_offset,
1259 			    u32 batch_len,
1260 			    bool is_master)
1261 {
1262 	u32 *cmd, *batch_end;
1263 	struct drm_i915_cmd_descriptor default_desc = noop_desc;
1264 	const struct drm_i915_cmd_descriptor *desc = &default_desc;
1265 	bool needs_clflush_after = false;
1266 	int ret = 0;
1267 
1268 	cmd = copy_batch(shadow_batch_obj, batch_obj,
1269 			 batch_start_offset, batch_len,
1270 			 &needs_clflush_after);
1271 	if (IS_ERR(cmd)) {
1272 		DRM_DEBUG_DRIVER("CMD: Failed to copy batch\n");
1273 		return PTR_ERR(cmd);
1274 	}
1275 
1276 	/*
1277 	 * We use the batch length as size because the shadow object is as
1278 	 * large or larger and copy_batch() will write MI_NOPs to the extra
1279 	 * space. Parsing should be faster in some cases this way.
1280 	 */
1281 	batch_end = cmd + (batch_len / sizeof(*batch_end));
1282 	do {
1283 		u32 length;
1284 
1285 		if (*cmd == MI_BATCH_BUFFER_END) {
1286 			if (needs_clflush_after) {
1287 				void *ptr = page_mask_bits(shadow_batch_obj->mm.mapping);
1288 				drm_clflush_virt_range(ptr,
1289 						       (void *)(cmd + 1) - ptr);
1290 			}
1291 			break;
1292 		}
1293 
1294 		desc = find_cmd(engine, *cmd, desc, &default_desc);
1295 		if (!desc) {
1296 			DRM_DEBUG_DRIVER("CMD: Unrecognized command: 0x%08X\n",
1297 					 *cmd);
1298 			ret = -EINVAL;
1299 			break;
1300 		}
1301 
1302 		/*
1303 		 * If the batch buffer contains a chained batch, return an
1304 		 * error that tells the caller to abort and dispatch the
1305 		 * workload as a non-secure batch.
1306 		 */
1307 		if (desc->cmd.value == MI_BATCH_BUFFER_START) {
1308 			ret = -EACCES;
1309 			break;
1310 		}
1311 
1312 		if (desc->flags & CMD_DESC_FIXED)
1313 			length = desc->length.fixed;
1314 		else
1315 			length = ((*cmd & desc->length.mask) + LENGTH_BIAS);
1316 
1317 		if ((batch_end - cmd) < length) {
1318 			DRM_DEBUG_DRIVER("CMD: Command length exceeds batch length: 0x%08X length=%u batchlen=%td\n",
1319 					 *cmd,
1320 					 length,
1321 					 batch_end - cmd);
1322 			ret = -EINVAL;
1323 			break;
1324 		}
1325 
1326 		if (!check_cmd(engine, desc, cmd, length, is_master)) {
1327 			ret = -EACCES;
1328 			break;
1329 		}
1330 
1331 		cmd += length;
1332 		if  (cmd >= batch_end) {
1333 			DRM_DEBUG_DRIVER("CMD: Got to the end of the buffer w/o a BBE cmd!\n");
1334 			ret = -EINVAL;
1335 			break;
1336 		}
1337 	} while (1);
1338 
1339 	i915_gem_object_unpin_map(shadow_batch_obj);
1340 	return ret;
1341 }
1342 
1343 /**
1344  * i915_cmd_parser_get_version() - get the cmd parser version number
1345  * @dev_priv: i915 device private
1346  *
1347  * The cmd parser maintains a simple increasing integer version number suitable
1348  * for passing to userspace clients to determine what operations are permitted.
1349  *
1350  * Return: the current version number of the cmd parser
1351  */
1352 int i915_cmd_parser_get_version(struct drm_i915_private *dev_priv)
1353 {
1354 	struct intel_engine_cs *engine;
1355 	enum intel_engine_id id;
1356 	bool active = false;
1357 
1358 	/* If the command parser is not enabled, report 0 - unsupported */
1359 	for_each_engine(engine, dev_priv, id) {
1360 		if (intel_engine_needs_cmd_parser(engine)) {
1361 			active = true;
1362 			break;
1363 		}
1364 	}
1365 	if (!active)
1366 		return 0;
1367 
1368 	/*
1369 	 * Command parser version history
1370 	 *
1371 	 * 1. Initial version. Checks batches and reports violations, but leaves
1372 	 *    hardware parsing enabled (so does not allow new use cases).
1373 	 * 2. Allow access to the MI_PREDICATE_SRC0 and
1374 	 *    MI_PREDICATE_SRC1 registers.
1375 	 * 3. Allow access to the GPGPU_THREADS_DISPATCHED register.
1376 	 * 4. L3 atomic chicken bits of HSW_SCRATCH1 and HSW_ROW_CHICKEN3.
1377 	 * 5. GPGPU dispatch compute indirect registers.
1378 	 * 6. TIMESTAMP register and Haswell CS GPR registers
1379 	 * 7. Allow MI_LOAD_REGISTER_REG between whitelisted registers.
1380 	 * 8. Don't report cmd_check() failures as EINVAL errors to userspace;
1381 	 *    rely on the HW to NOOP disallowed commands as it would without
1382 	 *    the parser enabled.
1383 	 * 9. Don't whitelist or handle oacontrol specially, as ownership
1384 	 *    for oacontrol state is moving to i915-perf.
1385 	 */
1386 	return 9;
1387 }
1388