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 #include "i915_memcpy.h"
32 
33 /**
34  * DOC: batch buffer command parser
35  *
36  * Motivation:
37  * Certain OpenGL features (e.g. transform feedback, performance monitoring)
38  * require userspace code to submit batches containing commands such as
39  * MI_LOAD_REGISTER_IMM to access various registers. Unfortunately, some
40  * generations of the hardware will noop these commands in "unsecure" batches
41  * (which includes all userspace batches submitted via i915) even though the
42  * commands may be safe and represent the intended programming model of the
43  * device.
44  *
45  * The software command parser is similar in operation to the command parsing
46  * done in hardware for unsecure batches. However, the software parser allows
47  * some operations that would be noop'd by hardware, if the parser determines
48  * the operation is safe, and submits the batch as "secure" to prevent hardware
49  * parsing.
50  *
51  * Threats:
52  * At a high level, the hardware (and software) checks attempt to prevent
53  * granting userspace undue privileges. There are three categories of privilege.
54  *
55  * First, commands which are explicitly defined as privileged or which should
56  * only be used by the kernel driver. The parser generally rejects such
57  * commands, though it may allow some from the drm master process.
58  *
59  * Second, commands which access registers. To support correct/enhanced
60  * userspace functionality, particularly certain OpenGL extensions, the parser
61  * provides a whitelist of registers which userspace may safely access (for both
62  * normal and drm master processes).
63  *
64  * Third, commands which access privileged memory (i.e. GGTT, HWS page, etc).
65  * The parser always rejects such commands.
66  *
67  * The majority of the problematic commands fall in the MI_* range, with only a
68  * few specific commands on each engine (e.g. PIPE_CONTROL and MI_FLUSH_DW).
69  *
70  * Implementation:
71  * Each engine maintains tables of commands and registers which the parser
72  * uses in scanning batch buffers submitted to that engine.
73  *
74  * Since the set of commands that the parser must check for is significantly
75  * smaller than the number of commands supported, the parser tables contain only
76  * those commands required by the parser. This generally works because command
77  * opcode ranges have standard command length encodings. So for commands that
78  * the parser does not need to check, it can easily skip them. This is
79  * implemented via a per-engine length decoding vfunc.
80  *
81  * Unfortunately, there are a number of commands that do not follow the standard
82  * length encoding for their opcode range, primarily amongst the MI_* commands.
83  * To handle this, the parser provides a way to define explicit "skip" entries
84  * in the per-engine command tables.
85  *
86  * Other command table entries map fairly directly to high level categories
87  * mentioned above: rejected, master-only, register whitelist. The parser
88  * implements a number of checks, including the privileged memory checks, via a
89  * general bitmasking mechanism.
90  */
91 
92 /*
93  * A command that requires special handling by the command parser.
94  */
95 struct drm_i915_cmd_descriptor {
96 	/*
97 	 * Flags describing how the command parser processes the command.
98 	 *
99 	 * CMD_DESC_FIXED: The command has a fixed length if this is set,
100 	 *                 a length mask if not set
101 	 * CMD_DESC_SKIP: The command is allowed but does not follow the
102 	 *                standard length encoding for the opcode range in
103 	 *                which it falls
104 	 * CMD_DESC_REJECT: The command is never allowed
105 	 * CMD_DESC_REGISTER: The command should be checked against the
106 	 *                    register whitelist for the appropriate ring
107 	 * CMD_DESC_MASTER: The command is allowed if the submitting process
108 	 *                  is the DRM master
109 	 */
110 	u32 flags;
111 #define CMD_DESC_FIXED    (1<<0)
112 #define CMD_DESC_SKIP     (1<<1)
113 #define CMD_DESC_REJECT   (1<<2)
114 #define CMD_DESC_REGISTER (1<<3)
115 #define CMD_DESC_BITMASK  (1<<4)
116 #define CMD_DESC_MASTER   (1<<5)
117 
118 	/*
119 	 * The command's unique identification bits and the bitmask to get them.
120 	 * This isn't strictly the opcode field as defined in the spec and may
121 	 * also include type, subtype, and/or subop fields.
122 	 */
123 	struct {
124 		u32 value;
125 		u32 mask;
126 	} cmd;
127 
128 	/*
129 	 * The command's length. The command is either fixed length (i.e. does
130 	 * not include a length field) or has a length field mask. The flag
131 	 * CMD_DESC_FIXED indicates a fixed length. Otherwise, the command has
132 	 * a length mask. All command entries in a command table must include
133 	 * length information.
134 	 */
135 	union {
136 		u32 fixed;
137 		u32 mask;
138 	} length;
139 
140 	/*
141 	 * Describes where to find a register address in the command to check
142 	 * against the ring's register whitelist. Only valid if flags has the
143 	 * CMD_DESC_REGISTER bit set.
144 	 *
145 	 * A non-zero step value implies that the command may access multiple
146 	 * registers in sequence (e.g. LRI), in that case step gives the
147 	 * distance in dwords between individual offset fields.
148 	 */
149 	struct {
150 		u32 offset;
151 		u32 mask;
152 		u32 step;
153 	} reg;
154 
155 #define MAX_CMD_DESC_BITMASKS 3
156 	/*
157 	 * Describes command checks where a particular dword is masked and
158 	 * compared against an expected value. If the command does not match
159 	 * the expected value, the parser rejects it. Only valid if flags has
160 	 * the CMD_DESC_BITMASK bit set. Only entries where mask is non-zero
161 	 * are valid.
162 	 *
163 	 * If the check specifies a non-zero condition_mask then the parser
164 	 * only performs the check when the bits specified by condition_mask
165 	 * are non-zero.
166 	 */
167 	struct {
168 		u32 offset;
169 		u32 mask;
170 		u32 expected;
171 		u32 condition_offset;
172 		u32 condition_mask;
173 	} bits[MAX_CMD_DESC_BITMASKS];
174 };
175 
176 /*
177  * A table of commands requiring special handling by the command parser.
178  *
179  * Each engine has an array of tables. Each table consists of an array of
180  * command descriptors, which must be sorted with command opcodes in
181  * ascending order.
182  */
183 struct drm_i915_cmd_table {
184 	const struct drm_i915_cmd_descriptor *table;
185 	int count;
186 };
187 
188 #define STD_MI_OPCODE_SHIFT  (32 - 9)
189 #define STD_3D_OPCODE_SHIFT  (32 - 16)
190 #define STD_2D_OPCODE_SHIFT  (32 - 10)
191 #define STD_MFX_OPCODE_SHIFT (32 - 16)
192 #define MIN_OPCODE_SHIFT 16
193 
194 #define CMD(op, opm, f, lm, fl, ...)				\
195 	{							\
196 		.flags = (fl) | ((f) ? CMD_DESC_FIXED : 0),	\
197 		.cmd = { (op), ~0u << (opm) },			\
198 		.length = { (lm) },				\
199 		__VA_ARGS__					\
200 	}
201 
202 /* Convenience macros to compress the tables */
203 #define SMI STD_MI_OPCODE_SHIFT
204 #define S3D STD_3D_OPCODE_SHIFT
205 #define S2D STD_2D_OPCODE_SHIFT
206 #define SMFX STD_MFX_OPCODE_SHIFT
207 #define F true
208 #define S CMD_DESC_SKIP
209 #define R CMD_DESC_REJECT
210 #define W CMD_DESC_REGISTER
211 #define B CMD_DESC_BITMASK
212 #define M CMD_DESC_MASTER
213 
214 /*            Command                          Mask   Fixed Len   Action
215 	      ---------------------------------------------------------- */
216 static const struct drm_i915_cmd_descriptor common_cmds[] = {
217 	CMD(  MI_NOOP,                          SMI,    F,  1,      S  ),
218 	CMD(  MI_USER_INTERRUPT,                SMI,    F,  1,      R  ),
219 	CMD(  MI_WAIT_FOR_EVENT,                SMI,    F,  1,      M  ),
220 	CMD(  MI_ARB_CHECK,                     SMI,    F,  1,      S  ),
221 	CMD(  MI_REPORT_HEAD,                   SMI,    F,  1,      S  ),
222 	CMD(  MI_SUSPEND_FLUSH,                 SMI,    F,  1,      S  ),
223 	CMD(  MI_SEMAPHORE_MBOX,                SMI,   !F,  0xFF,   R  ),
224 	CMD(  MI_STORE_DWORD_INDEX,             SMI,   !F,  0xFF,   R  ),
225 	CMD(  MI_LOAD_REGISTER_IMM(1),          SMI,   !F,  0xFF,   W,
226 	      .reg = { .offset = 1, .mask = 0x007FFFFC, .step = 2 }    ),
227 	CMD(  MI_STORE_REGISTER_MEM,            SMI,    F,  3,     W | B,
228 	      .reg = { .offset = 1, .mask = 0x007FFFFC },
229 	      .bits = {{
230 			.offset = 0,
231 			.mask = MI_GLOBAL_GTT,
232 			.expected = 0,
233 	      }},						       ),
234 	CMD(  MI_LOAD_REGISTER_MEM,             SMI,    F,  3,     W | B,
235 	      .reg = { .offset = 1, .mask = 0x007FFFFC },
236 	      .bits = {{
237 			.offset = 0,
238 			.mask = MI_GLOBAL_GTT,
239 			.expected = 0,
240 	      }},						       ),
241 	/*
242 	 * MI_BATCH_BUFFER_START requires some special handling. It's not
243 	 * really a 'skip' action but it doesn't seem like it's worth adding
244 	 * a new action. See i915_parse_cmds().
245 	 */
246 	CMD(  MI_BATCH_BUFFER_START,            SMI,   !F,  0xFF,   S  ),
247 };
248 
249 static const struct drm_i915_cmd_descriptor render_cmds[] = {
250 	CMD(  MI_FLUSH,                         SMI,    F,  1,      S  ),
251 	CMD(  MI_ARB_ON_OFF,                    SMI,    F,  1,      R  ),
252 	CMD(  MI_PREDICATE,                     SMI,    F,  1,      S  ),
253 	CMD(  MI_TOPOLOGY_FILTER,               SMI,    F,  1,      S  ),
254 	CMD(  MI_SET_APPID,                     SMI,    F,  1,      S  ),
255 	CMD(  MI_DISPLAY_FLIP,                  SMI,   !F,  0xFF,   R  ),
256 	CMD(  MI_SET_CONTEXT,                   SMI,   !F,  0xFF,   R  ),
257 	CMD(  MI_URB_CLEAR,                     SMI,   !F,  0xFF,   S  ),
258 	CMD(  MI_STORE_DWORD_IMM,               SMI,   !F,  0x3F,   B,
259 	      .bits = {{
260 			.offset = 0,
261 			.mask = MI_GLOBAL_GTT,
262 			.expected = 0,
263 	      }},						       ),
264 	CMD(  MI_UPDATE_GTT,                    SMI,   !F,  0xFF,   R  ),
265 	CMD(  MI_CLFLUSH,                       SMI,   !F,  0x3FF,  B,
266 	      .bits = {{
267 			.offset = 0,
268 			.mask = MI_GLOBAL_GTT,
269 			.expected = 0,
270 	      }},						       ),
271 	CMD(  MI_REPORT_PERF_COUNT,             SMI,   !F,  0x3F,   B,
272 	      .bits = {{
273 			.offset = 1,
274 			.mask = MI_REPORT_PERF_COUNT_GGTT,
275 			.expected = 0,
276 	      }},						       ),
277 	CMD(  MI_CONDITIONAL_BATCH_BUFFER_END,  SMI,   !F,  0xFF,   B,
278 	      .bits = {{
279 			.offset = 0,
280 			.mask = MI_GLOBAL_GTT,
281 			.expected = 0,
282 	      }},						       ),
283 	CMD(  GFX_OP_3DSTATE_VF_STATISTICS,     S3D,    F,  1,      S  ),
284 	CMD(  PIPELINE_SELECT,                  S3D,    F,  1,      S  ),
285 	CMD(  MEDIA_VFE_STATE,			S3D,   !F,  0xFFFF, B,
286 	      .bits = {{
287 			.offset = 2,
288 			.mask = MEDIA_VFE_STATE_MMIO_ACCESS_MASK,
289 			.expected = 0,
290 	      }},						       ),
291 	CMD(  GPGPU_OBJECT,                     S3D,   !F,  0xFF,   S  ),
292 	CMD(  GPGPU_WALKER,                     S3D,   !F,  0xFF,   S  ),
293 	CMD(  GFX_OP_3DSTATE_SO_DECL_LIST,      S3D,   !F,  0x1FF,  S  ),
294 	CMD(  GFX_OP_PIPE_CONTROL(5),           S3D,   !F,  0xFF,   B,
295 	      .bits = {{
296 			.offset = 1,
297 			.mask = (PIPE_CONTROL_MMIO_WRITE | PIPE_CONTROL_NOTIFY),
298 			.expected = 0,
299 	      },
300 	      {
301 			.offset = 1,
302 		        .mask = (PIPE_CONTROL_GLOBAL_GTT_IVB |
303 				 PIPE_CONTROL_STORE_DATA_INDEX),
304 			.expected = 0,
305 			.condition_offset = 1,
306 			.condition_mask = PIPE_CONTROL_POST_SYNC_OP_MASK,
307 	      }},						       ),
308 };
309 
310 static const struct drm_i915_cmd_descriptor hsw_render_cmds[] = {
311 	CMD(  MI_SET_PREDICATE,                 SMI,    F,  1,      S  ),
312 	CMD(  MI_RS_CONTROL,                    SMI,    F,  1,      S  ),
313 	CMD(  MI_URB_ATOMIC_ALLOC,              SMI,    F,  1,      S  ),
314 	CMD(  MI_SET_APPID,                     SMI,    F,  1,      S  ),
315 	CMD(  MI_RS_CONTEXT,                    SMI,    F,  1,      S  ),
316 	CMD(  MI_LOAD_SCAN_LINES_INCL,          SMI,   !F,  0x3F,   M  ),
317 	CMD(  MI_LOAD_SCAN_LINES_EXCL,          SMI,   !F,  0x3F,   R  ),
318 	CMD(  MI_LOAD_REGISTER_REG,             SMI,   !F,  0xFF,   W,
319 	      .reg = { .offset = 1, .mask = 0x007FFFFC, .step = 1 }    ),
320 	CMD(  MI_RS_STORE_DATA_IMM,             SMI,   !F,  0xFF,   S  ),
321 	CMD(  MI_LOAD_URB_MEM,                  SMI,   !F,  0xFF,   S  ),
322 	CMD(  MI_STORE_URB_MEM,                 SMI,   !F,  0xFF,   S  ),
323 	CMD(  GFX_OP_3DSTATE_DX9_CONSTANTF_VS,  S3D,   !F,  0x7FF,  S  ),
324 	CMD(  GFX_OP_3DSTATE_DX9_CONSTANTF_PS,  S3D,   !F,  0x7FF,  S  ),
325 
326 	CMD(  GFX_OP_3DSTATE_BINDING_TABLE_EDIT_VS,  S3D,   !F,  0x1FF,  S  ),
327 	CMD(  GFX_OP_3DSTATE_BINDING_TABLE_EDIT_GS,  S3D,   !F,  0x1FF,  S  ),
328 	CMD(  GFX_OP_3DSTATE_BINDING_TABLE_EDIT_HS,  S3D,   !F,  0x1FF,  S  ),
329 	CMD(  GFX_OP_3DSTATE_BINDING_TABLE_EDIT_DS,  S3D,   !F,  0x1FF,  S  ),
330 	CMD(  GFX_OP_3DSTATE_BINDING_TABLE_EDIT_PS,  S3D,   !F,  0x1FF,  S  ),
331 };
332 
333 static const struct drm_i915_cmd_descriptor video_cmds[] = {
334 	CMD(  MI_ARB_ON_OFF,                    SMI,    F,  1,      R  ),
335 	CMD(  MI_SET_APPID,                     SMI,    F,  1,      S  ),
336 	CMD(  MI_STORE_DWORD_IMM,               SMI,   !F,  0xFF,   B,
337 	      .bits = {{
338 			.offset = 0,
339 			.mask = MI_GLOBAL_GTT,
340 			.expected = 0,
341 	      }},						       ),
342 	CMD(  MI_UPDATE_GTT,                    SMI,   !F,  0x3F,   R  ),
343 	CMD(  MI_FLUSH_DW,                      SMI,   !F,  0x3F,   B,
344 	      .bits = {{
345 			.offset = 0,
346 			.mask = MI_FLUSH_DW_NOTIFY,
347 			.expected = 0,
348 	      },
349 	      {
350 			.offset = 1,
351 			.mask = MI_FLUSH_DW_USE_GTT,
352 			.expected = 0,
353 			.condition_offset = 0,
354 			.condition_mask = MI_FLUSH_DW_OP_MASK,
355 	      },
356 	      {
357 			.offset = 0,
358 			.mask = MI_FLUSH_DW_STORE_INDEX,
359 			.expected = 0,
360 			.condition_offset = 0,
361 			.condition_mask = MI_FLUSH_DW_OP_MASK,
362 	      }},						       ),
363 	CMD(  MI_CONDITIONAL_BATCH_BUFFER_END,  SMI,   !F,  0xFF,   B,
364 	      .bits = {{
365 			.offset = 0,
366 			.mask = MI_GLOBAL_GTT,
367 			.expected = 0,
368 	      }},						       ),
369 	/*
370 	 * MFX_WAIT doesn't fit the way we handle length for most commands.
371 	 * It has a length field but it uses a non-standard length bias.
372 	 * It is always 1 dword though, so just treat it as fixed length.
373 	 */
374 	CMD(  MFX_WAIT,                         SMFX,   F,  1,      S  ),
375 };
376 
377 static const struct drm_i915_cmd_descriptor vecs_cmds[] = {
378 	CMD(  MI_ARB_ON_OFF,                    SMI,    F,  1,      R  ),
379 	CMD(  MI_SET_APPID,                     SMI,    F,  1,      S  ),
380 	CMD(  MI_STORE_DWORD_IMM,               SMI,   !F,  0xFF,   B,
381 	      .bits = {{
382 			.offset = 0,
383 			.mask = MI_GLOBAL_GTT,
384 			.expected = 0,
385 	      }},						       ),
386 	CMD(  MI_UPDATE_GTT,                    SMI,   !F,  0x3F,   R  ),
387 	CMD(  MI_FLUSH_DW,                      SMI,   !F,  0x3F,   B,
388 	      .bits = {{
389 			.offset = 0,
390 			.mask = MI_FLUSH_DW_NOTIFY,
391 			.expected = 0,
392 	      },
393 	      {
394 			.offset = 1,
395 			.mask = MI_FLUSH_DW_USE_GTT,
396 			.expected = 0,
397 			.condition_offset = 0,
398 			.condition_mask = MI_FLUSH_DW_OP_MASK,
399 	      },
400 	      {
401 			.offset = 0,
402 			.mask = MI_FLUSH_DW_STORE_INDEX,
403 			.expected = 0,
404 			.condition_offset = 0,
405 			.condition_mask = MI_FLUSH_DW_OP_MASK,
406 	      }},						       ),
407 	CMD(  MI_CONDITIONAL_BATCH_BUFFER_END,  SMI,   !F,  0xFF,   B,
408 	      .bits = {{
409 			.offset = 0,
410 			.mask = MI_GLOBAL_GTT,
411 			.expected = 0,
412 	      }},						       ),
413 };
414 
415 static const struct drm_i915_cmd_descriptor blt_cmds[] = {
416 	CMD(  MI_DISPLAY_FLIP,                  SMI,   !F,  0xFF,   R  ),
417 	CMD(  MI_STORE_DWORD_IMM,               SMI,   !F,  0x3FF,  B,
418 	      .bits = {{
419 			.offset = 0,
420 			.mask = MI_GLOBAL_GTT,
421 			.expected = 0,
422 	      }},						       ),
423 	CMD(  MI_UPDATE_GTT,                    SMI,   !F,  0x3F,   R  ),
424 	CMD(  MI_FLUSH_DW,                      SMI,   !F,  0x3F,   B,
425 	      .bits = {{
426 			.offset = 0,
427 			.mask = MI_FLUSH_DW_NOTIFY,
428 			.expected = 0,
429 	      },
430 	      {
431 			.offset = 1,
432 			.mask = MI_FLUSH_DW_USE_GTT,
433 			.expected = 0,
434 			.condition_offset = 0,
435 			.condition_mask = MI_FLUSH_DW_OP_MASK,
436 	      },
437 	      {
438 			.offset = 0,
439 			.mask = MI_FLUSH_DW_STORE_INDEX,
440 			.expected = 0,
441 			.condition_offset = 0,
442 			.condition_mask = MI_FLUSH_DW_OP_MASK,
443 	      }},						       ),
444 	CMD(  COLOR_BLT,                        S2D,   !F,  0x3F,   S  ),
445 	CMD(  SRC_COPY_BLT,                     S2D,   !F,  0x3F,   S  ),
446 };
447 
448 static const struct drm_i915_cmd_descriptor hsw_blt_cmds[] = {
449 	CMD(  MI_LOAD_SCAN_LINES_INCL,          SMI,   !F,  0x3F,   M  ),
450 	CMD(  MI_LOAD_SCAN_LINES_EXCL,          SMI,   !F,  0x3F,   R  ),
451 };
452 
453 static const struct drm_i915_cmd_descriptor noop_desc =
454 	CMD(MI_NOOP, SMI, F, 1, S);
455 
456 #undef CMD
457 #undef SMI
458 #undef S3D
459 #undef S2D
460 #undef SMFX
461 #undef F
462 #undef S
463 #undef R
464 #undef W
465 #undef B
466 #undef M
467 
468 static const struct drm_i915_cmd_table gen7_render_cmds[] = {
469 	{ common_cmds, ARRAY_SIZE(common_cmds) },
470 	{ render_cmds, ARRAY_SIZE(render_cmds) },
471 };
472 
473 static const struct drm_i915_cmd_table hsw_render_ring_cmds[] = {
474 	{ common_cmds, ARRAY_SIZE(common_cmds) },
475 	{ render_cmds, ARRAY_SIZE(render_cmds) },
476 	{ hsw_render_cmds, ARRAY_SIZE(hsw_render_cmds) },
477 };
478 
479 static const struct drm_i915_cmd_table gen7_video_cmds[] = {
480 	{ common_cmds, ARRAY_SIZE(common_cmds) },
481 	{ video_cmds, ARRAY_SIZE(video_cmds) },
482 };
483 
484 static const struct drm_i915_cmd_table hsw_vebox_cmds[] = {
485 	{ common_cmds, ARRAY_SIZE(common_cmds) },
486 	{ vecs_cmds, ARRAY_SIZE(vecs_cmds) },
487 };
488 
489 static const struct drm_i915_cmd_table gen7_blt_cmds[] = {
490 	{ common_cmds, ARRAY_SIZE(common_cmds) },
491 	{ blt_cmds, ARRAY_SIZE(blt_cmds) },
492 };
493 
494 static const struct drm_i915_cmd_table hsw_blt_ring_cmds[] = {
495 	{ common_cmds, ARRAY_SIZE(common_cmds) },
496 	{ blt_cmds, ARRAY_SIZE(blt_cmds) },
497 	{ hsw_blt_cmds, ARRAY_SIZE(hsw_blt_cmds) },
498 };
499 
500 /*
501  * Register whitelists, sorted by increasing register offset.
502  */
503 
504 /*
505  * An individual whitelist entry granting access to register addr.  If
506  * mask is non-zero the argument of immediate register writes will be
507  * AND-ed with mask, and the command will be rejected if the result
508  * doesn't match value.
509  *
510  * Registers with non-zero mask are only allowed to be written using
511  * LRI.
512  */
513 struct drm_i915_reg_descriptor {
514 	i915_reg_t addr;
515 	u32 mask;
516 	u32 value;
517 };
518 
519 /* Convenience macro for adding 32-bit registers. */
520 #define REG32(_reg, ...) \
521 	{ .addr = (_reg), __VA_ARGS__ }
522 
523 /*
524  * Convenience macro for adding 64-bit registers.
525  *
526  * Some registers that userspace accesses are 64 bits. The register
527  * access commands only allow 32-bit accesses. Hence, we have to include
528  * entries for both halves of the 64-bit registers.
529  */
530 #define REG64(_reg) \
531 	{ .addr = _reg }, \
532 	{ .addr = _reg ## _UDW }
533 
534 #define REG64_IDX(_reg, idx) \
535 	{ .addr = _reg(idx) }, \
536 	{ .addr = _reg ## _UDW(idx) }
537 
538 static const struct drm_i915_reg_descriptor gen7_render_regs[] = {
539 	REG64(GPGPU_THREADS_DISPATCHED),
540 	REG64(HS_INVOCATION_COUNT),
541 	REG64(DS_INVOCATION_COUNT),
542 	REG64(IA_VERTICES_COUNT),
543 	REG64(IA_PRIMITIVES_COUNT),
544 	REG64(VS_INVOCATION_COUNT),
545 	REG64(GS_INVOCATION_COUNT),
546 	REG64(GS_PRIMITIVES_COUNT),
547 	REG64(CL_INVOCATION_COUNT),
548 	REG64(CL_PRIMITIVES_COUNT),
549 	REG64(PS_INVOCATION_COUNT),
550 	REG64(PS_DEPTH_COUNT),
551 	REG64_IDX(RING_TIMESTAMP, RENDER_RING_BASE),
552 	REG64(MI_PREDICATE_SRC0),
553 	REG64(MI_PREDICATE_SRC1),
554 	REG32(GEN7_3DPRIM_END_OFFSET),
555 	REG32(GEN7_3DPRIM_START_VERTEX),
556 	REG32(GEN7_3DPRIM_VERTEX_COUNT),
557 	REG32(GEN7_3DPRIM_INSTANCE_COUNT),
558 	REG32(GEN7_3DPRIM_START_INSTANCE),
559 	REG32(GEN7_3DPRIM_BASE_VERTEX),
560 	REG32(GEN7_GPGPU_DISPATCHDIMX),
561 	REG32(GEN7_GPGPU_DISPATCHDIMY),
562 	REG32(GEN7_GPGPU_DISPATCHDIMZ),
563 	REG64_IDX(RING_TIMESTAMP, BSD_RING_BASE),
564 	REG64_IDX(GEN7_SO_NUM_PRIMS_WRITTEN, 0),
565 	REG64_IDX(GEN7_SO_NUM_PRIMS_WRITTEN, 1),
566 	REG64_IDX(GEN7_SO_NUM_PRIMS_WRITTEN, 2),
567 	REG64_IDX(GEN7_SO_NUM_PRIMS_WRITTEN, 3),
568 	REG64_IDX(GEN7_SO_PRIM_STORAGE_NEEDED, 0),
569 	REG64_IDX(GEN7_SO_PRIM_STORAGE_NEEDED, 1),
570 	REG64_IDX(GEN7_SO_PRIM_STORAGE_NEEDED, 2),
571 	REG64_IDX(GEN7_SO_PRIM_STORAGE_NEEDED, 3),
572 	REG32(GEN7_SO_WRITE_OFFSET(0)),
573 	REG32(GEN7_SO_WRITE_OFFSET(1)),
574 	REG32(GEN7_SO_WRITE_OFFSET(2)),
575 	REG32(GEN7_SO_WRITE_OFFSET(3)),
576 	REG32(GEN7_L3SQCREG1),
577 	REG32(GEN7_L3CNTLREG2),
578 	REG32(GEN7_L3CNTLREG3),
579 	REG64_IDX(RING_TIMESTAMP, BLT_RING_BASE),
580 };
581 
582 static const struct drm_i915_reg_descriptor hsw_render_regs[] = {
583 	REG64_IDX(HSW_CS_GPR, 0),
584 	REG64_IDX(HSW_CS_GPR, 1),
585 	REG64_IDX(HSW_CS_GPR, 2),
586 	REG64_IDX(HSW_CS_GPR, 3),
587 	REG64_IDX(HSW_CS_GPR, 4),
588 	REG64_IDX(HSW_CS_GPR, 5),
589 	REG64_IDX(HSW_CS_GPR, 6),
590 	REG64_IDX(HSW_CS_GPR, 7),
591 	REG64_IDX(HSW_CS_GPR, 8),
592 	REG64_IDX(HSW_CS_GPR, 9),
593 	REG64_IDX(HSW_CS_GPR, 10),
594 	REG64_IDX(HSW_CS_GPR, 11),
595 	REG64_IDX(HSW_CS_GPR, 12),
596 	REG64_IDX(HSW_CS_GPR, 13),
597 	REG64_IDX(HSW_CS_GPR, 14),
598 	REG64_IDX(HSW_CS_GPR, 15),
599 	REG32(HSW_SCRATCH1,
600 	      .mask = ~HSW_SCRATCH1_L3_DATA_ATOMICS_DISABLE,
601 	      .value = 0),
602 	REG32(HSW_ROW_CHICKEN3,
603 	      .mask = ~(HSW_ROW_CHICKEN3_L3_GLOBAL_ATOMICS_DISABLE << 16 |
604                         HSW_ROW_CHICKEN3_L3_GLOBAL_ATOMICS_DISABLE),
605 	      .value = 0),
606 };
607 
608 static const struct drm_i915_reg_descriptor gen7_blt_regs[] = {
609 	REG64_IDX(RING_TIMESTAMP, RENDER_RING_BASE),
610 	REG64_IDX(RING_TIMESTAMP, BSD_RING_BASE),
611 	REG32(BCS_SWCTRL),
612 	REG64_IDX(RING_TIMESTAMP, BLT_RING_BASE),
613 };
614 
615 static const struct drm_i915_reg_descriptor ivb_master_regs[] = {
616 	REG32(FORCEWAKE_MT),
617 	REG32(DERRMR),
618 	REG32(GEN7_PIPE_DE_LOAD_SL(PIPE_A)),
619 	REG32(GEN7_PIPE_DE_LOAD_SL(PIPE_B)),
620 	REG32(GEN7_PIPE_DE_LOAD_SL(PIPE_C)),
621 };
622 
623 static const struct drm_i915_reg_descriptor hsw_master_regs[] = {
624 	REG32(FORCEWAKE_MT),
625 	REG32(DERRMR),
626 };
627 
628 #undef REG64
629 #undef REG32
630 
631 struct drm_i915_reg_table {
632 	const struct drm_i915_reg_descriptor *regs;
633 	int num_regs;
634 	bool master;
635 };
636 
637 static const struct drm_i915_reg_table ivb_render_reg_tables[] = {
638 	{ gen7_render_regs, ARRAY_SIZE(gen7_render_regs), false },
639 	{ ivb_master_regs, ARRAY_SIZE(ivb_master_regs), true },
640 };
641 
642 static const struct drm_i915_reg_table ivb_blt_reg_tables[] = {
643 	{ gen7_blt_regs, ARRAY_SIZE(gen7_blt_regs), false },
644 	{ ivb_master_regs, ARRAY_SIZE(ivb_master_regs), true },
645 };
646 
647 static const struct drm_i915_reg_table hsw_render_reg_tables[] = {
648 	{ gen7_render_regs, ARRAY_SIZE(gen7_render_regs), false },
649 	{ hsw_render_regs, ARRAY_SIZE(hsw_render_regs), false },
650 	{ hsw_master_regs, ARRAY_SIZE(hsw_master_regs), true },
651 };
652 
653 static const struct drm_i915_reg_table hsw_blt_reg_tables[] = {
654 	{ gen7_blt_regs, ARRAY_SIZE(gen7_blt_regs), false },
655 	{ hsw_master_regs, ARRAY_SIZE(hsw_master_regs), true },
656 };
657 
658 static u32 gen7_render_get_cmd_length_mask(u32 cmd_header)
659 {
660 	u32 client = cmd_header >> INSTR_CLIENT_SHIFT;
661 	u32 subclient =
662 		(cmd_header & INSTR_SUBCLIENT_MASK) >> INSTR_SUBCLIENT_SHIFT;
663 
664 	if (client == INSTR_MI_CLIENT)
665 		return 0x3F;
666 	else if (client == INSTR_RC_CLIENT) {
667 		if (subclient == INSTR_MEDIA_SUBCLIENT)
668 			return 0xFFFF;
669 		else
670 			return 0xFF;
671 	}
672 
673 	DRM_DEBUG_DRIVER("CMD: Abnormal rcs cmd length! 0x%08X\n", cmd_header);
674 	return 0;
675 }
676 
677 static u32 gen7_bsd_get_cmd_length_mask(u32 cmd_header)
678 {
679 	u32 client = cmd_header >> INSTR_CLIENT_SHIFT;
680 	u32 subclient =
681 		(cmd_header & INSTR_SUBCLIENT_MASK) >> INSTR_SUBCLIENT_SHIFT;
682 	u32 op = (cmd_header & INSTR_26_TO_24_MASK) >> INSTR_26_TO_24_SHIFT;
683 
684 	if (client == INSTR_MI_CLIENT)
685 		return 0x3F;
686 	else if (client == INSTR_RC_CLIENT) {
687 		if (subclient == INSTR_MEDIA_SUBCLIENT) {
688 			if (op == 6)
689 				return 0xFFFF;
690 			else
691 				return 0xFFF;
692 		} else
693 			return 0xFF;
694 	}
695 
696 	DRM_DEBUG_DRIVER("CMD: Abnormal bsd cmd length! 0x%08X\n", cmd_header);
697 	return 0;
698 }
699 
700 static u32 gen7_blt_get_cmd_length_mask(u32 cmd_header)
701 {
702 	u32 client = cmd_header >> INSTR_CLIENT_SHIFT;
703 
704 	if (client == INSTR_MI_CLIENT)
705 		return 0x3F;
706 	else if (client == INSTR_BC_CLIENT)
707 		return 0xFF;
708 
709 	DRM_DEBUG_DRIVER("CMD: Abnormal blt cmd length! 0x%08X\n", cmd_header);
710 	return 0;
711 }
712 
713 static bool validate_cmds_sorted(const struct intel_engine_cs *engine,
714 				 const struct drm_i915_cmd_table *cmd_tables,
715 				 int cmd_table_count)
716 {
717 	int i;
718 	bool ret = true;
719 
720 	if (!cmd_tables || cmd_table_count == 0)
721 		return true;
722 
723 	for (i = 0; i < cmd_table_count; i++) {
724 		const struct drm_i915_cmd_table *table = &cmd_tables[i];
725 		u32 previous = 0;
726 		int j;
727 
728 		for (j = 0; j < table->count; j++) {
729 			const struct drm_i915_cmd_descriptor *desc =
730 				&table->table[j];
731 			u32 curr = desc->cmd.value & desc->cmd.mask;
732 
733 			if (curr < previous) {
734 				DRM_ERROR("CMD: %s [%d] command table not sorted: "
735 					  "table=%d entry=%d cmd=0x%08X prev=0x%08X\n",
736 					  engine->name, engine->id,
737 					  i, j, curr, previous);
738 				ret = false;
739 			}
740 
741 			previous = curr;
742 		}
743 	}
744 
745 	return ret;
746 }
747 
748 static bool check_sorted(const struct intel_engine_cs *engine,
749 			 const struct drm_i915_reg_descriptor *reg_table,
750 			 int reg_count)
751 {
752 	int i;
753 	u32 previous = 0;
754 	bool ret = true;
755 
756 	for (i = 0; i < reg_count; i++) {
757 		u32 curr = i915_mmio_reg_offset(reg_table[i].addr);
758 
759 		if (curr < previous) {
760 			DRM_ERROR("CMD: %s [%d] register table not sorted: "
761 				  "entry=%d reg=0x%08X prev=0x%08X\n",
762 				  engine->name, engine->id,
763 				  i, curr, previous);
764 			ret = false;
765 		}
766 
767 		previous = curr;
768 	}
769 
770 	return ret;
771 }
772 
773 static bool validate_regs_sorted(struct intel_engine_cs *engine)
774 {
775 	int i;
776 	const struct drm_i915_reg_table *table;
777 
778 	for (i = 0; i < engine->reg_table_count; i++) {
779 		table = &engine->reg_tables[i];
780 		if (!check_sorted(engine, table->regs, table->num_regs))
781 			return false;
782 	}
783 
784 	return true;
785 }
786 
787 struct cmd_node {
788 	const struct drm_i915_cmd_descriptor *desc;
789 	struct hlist_node node;
790 };
791 
792 /*
793  * Different command ranges have different numbers of bits for the opcode. For
794  * example, MI commands use bits 31:23 while 3D commands use bits 31:16. The
795  * problem is that, for example, MI commands use bits 22:16 for other fields
796  * such as GGTT vs PPGTT bits. If we include those bits in the mask then when
797  * we mask a command from a batch it could hash to the wrong bucket due to
798  * non-opcode bits being set. But if we don't include those bits, some 3D
799  * commands may hash to the same bucket due to not including opcode bits that
800  * make the command unique. For now, we will risk hashing to the same bucket.
801  */
802 static inline u32 cmd_header_key(u32 x)
803 {
804 	switch (x >> INSTR_CLIENT_SHIFT) {
805 	default:
806 	case INSTR_MI_CLIENT:
807 		return x >> STD_MI_OPCODE_SHIFT;
808 	case INSTR_RC_CLIENT:
809 		return x >> STD_3D_OPCODE_SHIFT;
810 	case INSTR_BC_CLIENT:
811 		return x >> STD_2D_OPCODE_SHIFT;
812 	}
813 }
814 
815 static int init_hash_table(struct intel_engine_cs *engine,
816 			   const struct drm_i915_cmd_table *cmd_tables,
817 			   int cmd_table_count)
818 {
819 	int i, j;
820 
821 	hash_init(engine->cmd_hash);
822 
823 	for (i = 0; i < cmd_table_count; i++) {
824 		const struct drm_i915_cmd_table *table = &cmd_tables[i];
825 
826 		for (j = 0; j < table->count; j++) {
827 			const struct drm_i915_cmd_descriptor *desc =
828 				&table->table[j];
829 			struct cmd_node *desc_node =
830 				kmalloc(sizeof(*desc_node), GFP_KERNEL);
831 
832 			if (!desc_node)
833 				return -ENOMEM;
834 
835 			desc_node->desc = desc;
836 			hash_add(engine->cmd_hash, &desc_node->node,
837 				 cmd_header_key(desc->cmd.value));
838 		}
839 	}
840 
841 	return 0;
842 }
843 
844 static void fini_hash_table(struct intel_engine_cs *engine)
845 {
846 	struct hlist_node *tmp;
847 	struct cmd_node *desc_node;
848 	int i;
849 
850 	hash_for_each_safe(engine->cmd_hash, i, tmp, desc_node, node) {
851 		hash_del(&desc_node->node);
852 		kfree(desc_node);
853 	}
854 }
855 
856 /**
857  * intel_engine_init_cmd_parser() - set cmd parser related fields for an engine
858  * @engine: the engine to initialize
859  *
860  * Optionally initializes fields related to batch buffer command parsing in the
861  * struct intel_engine_cs based on whether the platform requires software
862  * command parsing.
863  */
864 void intel_engine_init_cmd_parser(struct intel_engine_cs *engine)
865 {
866 	const struct drm_i915_cmd_table *cmd_tables;
867 	int cmd_table_count;
868 	int ret;
869 
870 	if (!IS_GEN(engine->i915, 7))
871 		return;
872 
873 	switch (engine->class) {
874 	case RENDER_CLASS:
875 		if (IS_HASWELL(engine->i915)) {
876 			cmd_tables = hsw_render_ring_cmds;
877 			cmd_table_count =
878 				ARRAY_SIZE(hsw_render_ring_cmds);
879 		} else {
880 			cmd_tables = gen7_render_cmds;
881 			cmd_table_count = ARRAY_SIZE(gen7_render_cmds);
882 		}
883 
884 		if (IS_HASWELL(engine->i915)) {
885 			engine->reg_tables = hsw_render_reg_tables;
886 			engine->reg_table_count = ARRAY_SIZE(hsw_render_reg_tables);
887 		} else {
888 			engine->reg_tables = ivb_render_reg_tables;
889 			engine->reg_table_count = ARRAY_SIZE(ivb_render_reg_tables);
890 		}
891 
892 		engine->get_cmd_length_mask = gen7_render_get_cmd_length_mask;
893 		break;
894 	case VIDEO_DECODE_CLASS:
895 		cmd_tables = gen7_video_cmds;
896 		cmd_table_count = ARRAY_SIZE(gen7_video_cmds);
897 		engine->get_cmd_length_mask = gen7_bsd_get_cmd_length_mask;
898 		break;
899 	case COPY_ENGINE_CLASS:
900 		if (IS_HASWELL(engine->i915)) {
901 			cmd_tables = hsw_blt_ring_cmds;
902 			cmd_table_count = ARRAY_SIZE(hsw_blt_ring_cmds);
903 		} else {
904 			cmd_tables = gen7_blt_cmds;
905 			cmd_table_count = ARRAY_SIZE(gen7_blt_cmds);
906 		}
907 
908 		if (IS_HASWELL(engine->i915)) {
909 			engine->reg_tables = hsw_blt_reg_tables;
910 			engine->reg_table_count = ARRAY_SIZE(hsw_blt_reg_tables);
911 		} else {
912 			engine->reg_tables = ivb_blt_reg_tables;
913 			engine->reg_table_count = ARRAY_SIZE(ivb_blt_reg_tables);
914 		}
915 
916 		engine->get_cmd_length_mask = gen7_blt_get_cmd_length_mask;
917 		break;
918 	case VIDEO_ENHANCEMENT_CLASS:
919 		cmd_tables = hsw_vebox_cmds;
920 		cmd_table_count = ARRAY_SIZE(hsw_vebox_cmds);
921 		/* VECS can use the same length_mask function as VCS */
922 		engine->get_cmd_length_mask = gen7_bsd_get_cmd_length_mask;
923 		break;
924 	default:
925 		MISSING_CASE(engine->class);
926 		return;
927 	}
928 
929 	if (!validate_cmds_sorted(engine, cmd_tables, cmd_table_count)) {
930 		DRM_ERROR("%s: command descriptions are not sorted\n",
931 			  engine->name);
932 		return;
933 	}
934 	if (!validate_regs_sorted(engine)) {
935 		DRM_ERROR("%s: registers are not sorted\n", engine->name);
936 		return;
937 	}
938 
939 	ret = init_hash_table(engine, cmd_tables, cmd_table_count);
940 	if (ret) {
941 		DRM_ERROR("%s: initialised failed!\n", engine->name);
942 		fini_hash_table(engine);
943 		return;
944 	}
945 
946 	engine->flags |= I915_ENGINE_NEEDS_CMD_PARSER;
947 }
948 
949 /**
950  * intel_engine_cleanup_cmd_parser() - clean up cmd parser related fields
951  * @engine: the engine to clean up
952  *
953  * Releases any resources related to command parsing that may have been
954  * initialized for the specified engine.
955  */
956 void intel_engine_cleanup_cmd_parser(struct intel_engine_cs *engine)
957 {
958 	if (!intel_engine_needs_cmd_parser(engine))
959 		return;
960 
961 	fini_hash_table(engine);
962 }
963 
964 static const struct drm_i915_cmd_descriptor*
965 find_cmd_in_table(struct intel_engine_cs *engine,
966 		  u32 cmd_header)
967 {
968 	struct cmd_node *desc_node;
969 
970 	hash_for_each_possible(engine->cmd_hash, desc_node, node,
971 			       cmd_header_key(cmd_header)) {
972 		const struct drm_i915_cmd_descriptor *desc = desc_node->desc;
973 		if (((cmd_header ^ desc->cmd.value) & desc->cmd.mask) == 0)
974 			return desc;
975 	}
976 
977 	return NULL;
978 }
979 
980 /*
981  * Returns a pointer to a descriptor for the command specified by cmd_header.
982  *
983  * The caller must supply space for a default descriptor via the default_desc
984  * parameter. If no descriptor for the specified command exists in the engine's
985  * command parser tables, this function fills in default_desc based on the
986  * engine's default length encoding and returns default_desc.
987  */
988 static const struct drm_i915_cmd_descriptor*
989 find_cmd(struct intel_engine_cs *engine,
990 	 u32 cmd_header,
991 	 const struct drm_i915_cmd_descriptor *desc,
992 	 struct drm_i915_cmd_descriptor *default_desc)
993 {
994 	u32 mask;
995 
996 	if (((cmd_header ^ desc->cmd.value) & desc->cmd.mask) == 0)
997 		return desc;
998 
999 	desc = find_cmd_in_table(engine, cmd_header);
1000 	if (desc)
1001 		return desc;
1002 
1003 	mask = engine->get_cmd_length_mask(cmd_header);
1004 	if (!mask)
1005 		return NULL;
1006 
1007 	default_desc->cmd.value = cmd_header;
1008 	default_desc->cmd.mask = ~0u << MIN_OPCODE_SHIFT;
1009 	default_desc->length.mask = mask;
1010 	default_desc->flags = CMD_DESC_SKIP;
1011 	return default_desc;
1012 }
1013 
1014 static const struct drm_i915_reg_descriptor *
1015 __find_reg(const struct drm_i915_reg_descriptor *table, int count, u32 addr)
1016 {
1017 	int start = 0, end = count;
1018 	while (start < end) {
1019 		int mid = start + (end - start) / 2;
1020 		int ret = addr - i915_mmio_reg_offset(table[mid].addr);
1021 		if (ret < 0)
1022 			end = mid;
1023 		else if (ret > 0)
1024 			start = mid + 1;
1025 		else
1026 			return &table[mid];
1027 	}
1028 	return NULL;
1029 }
1030 
1031 static const struct drm_i915_reg_descriptor *
1032 find_reg(const struct intel_engine_cs *engine, bool is_master, u32 addr)
1033 {
1034 	const struct drm_i915_reg_table *table = engine->reg_tables;
1035 	int count = engine->reg_table_count;
1036 
1037 	for (; count > 0; ++table, --count) {
1038 		if (!table->master || is_master) {
1039 			const struct drm_i915_reg_descriptor *reg;
1040 
1041 			reg = __find_reg(table->regs, table->num_regs, addr);
1042 			if (reg != NULL)
1043 				return reg;
1044 		}
1045 	}
1046 
1047 	return NULL;
1048 }
1049 
1050 /* Returns a vmap'd pointer to dst_obj, which the caller must unmap */
1051 static u32 *copy_batch(struct drm_i915_gem_object *dst_obj,
1052 		       struct drm_i915_gem_object *src_obj,
1053 		       u32 batch_start_offset,
1054 		       u32 batch_len,
1055 		       bool *needs_clflush_after)
1056 {
1057 	unsigned int src_needs_clflush;
1058 	unsigned int dst_needs_clflush;
1059 	void *dst, *src;
1060 	int ret;
1061 
1062 	ret = i915_gem_object_prepare_write(dst_obj, &dst_needs_clflush);
1063 	if (ret)
1064 		return ERR_PTR(ret);
1065 
1066 	dst = i915_gem_object_pin_map(dst_obj, I915_MAP_FORCE_WB);
1067 	i915_gem_object_finish_access(dst_obj);
1068 	if (IS_ERR(dst))
1069 		return dst;
1070 
1071 	ret = i915_gem_object_prepare_read(src_obj, &src_needs_clflush);
1072 	if (ret) {
1073 		i915_gem_object_unpin_map(dst_obj);
1074 		return ERR_PTR(ret);
1075 	}
1076 
1077 	src = ERR_PTR(-ENODEV);
1078 	if (src_needs_clflush &&
1079 	    i915_can_memcpy_from_wc(NULL, batch_start_offset, 0)) {
1080 		src = i915_gem_object_pin_map(src_obj, I915_MAP_WC);
1081 		if (!IS_ERR(src)) {
1082 			i915_memcpy_from_wc(dst,
1083 					    src + batch_start_offset,
1084 					    ALIGN(batch_len, 16));
1085 			i915_gem_object_unpin_map(src_obj);
1086 		}
1087 	}
1088 	if (IS_ERR(src)) {
1089 		void *ptr;
1090 		int offset, n;
1091 
1092 		offset = offset_in_page(batch_start_offset);
1093 
1094 		/* We can avoid clflushing partial cachelines before the write
1095 		 * if we only every write full cache-lines. Since we know that
1096 		 * both the source and destination are in multiples of
1097 		 * PAGE_SIZE, we can simply round up to the next cacheline.
1098 		 * We don't care about copying too much here as we only
1099 		 * validate up to the end of the batch.
1100 		 */
1101 		if (dst_needs_clflush & CLFLUSH_BEFORE)
1102 			batch_len = roundup(batch_len,
1103 					    boot_cpu_data.x86_clflush_size);
1104 
1105 		ptr = dst;
1106 		for (n = batch_start_offset >> PAGE_SHIFT; batch_len; n++) {
1107 			int len = min_t(int, batch_len, PAGE_SIZE - offset);
1108 
1109 			src = kmap_atomic(i915_gem_object_get_page(src_obj, n));
1110 			if (src_needs_clflush)
1111 				drm_clflush_virt_range(src + offset, len);
1112 			memcpy(ptr, src + offset, len);
1113 			kunmap_atomic(src);
1114 
1115 			ptr += len;
1116 			batch_len -= len;
1117 			offset = 0;
1118 		}
1119 	}
1120 
1121 	i915_gem_object_finish_access(src_obj);
1122 
1123 	/* dst_obj is returned with vmap pinned */
1124 	*needs_clflush_after = dst_needs_clflush & CLFLUSH_AFTER;
1125 
1126 	return dst;
1127 }
1128 
1129 static bool check_cmd(const struct intel_engine_cs *engine,
1130 		      const struct drm_i915_cmd_descriptor *desc,
1131 		      const u32 *cmd, u32 length,
1132 		      const bool is_master)
1133 {
1134 	if (desc->flags & CMD_DESC_SKIP)
1135 		return true;
1136 
1137 	if (desc->flags & CMD_DESC_REJECT) {
1138 		DRM_DEBUG_DRIVER("CMD: Rejected command: 0x%08X\n", *cmd);
1139 		return false;
1140 	}
1141 
1142 	if ((desc->flags & CMD_DESC_MASTER) && !is_master) {
1143 		DRM_DEBUG_DRIVER("CMD: Rejected master-only command: 0x%08X\n",
1144 				 *cmd);
1145 		return false;
1146 	}
1147 
1148 	if (desc->flags & CMD_DESC_REGISTER) {
1149 		/*
1150 		 * Get the distance between individual register offset
1151 		 * fields if the command can perform more than one
1152 		 * access at a time.
1153 		 */
1154 		const u32 step = desc->reg.step ? desc->reg.step : length;
1155 		u32 offset;
1156 
1157 		for (offset = desc->reg.offset; offset < length;
1158 		     offset += step) {
1159 			const u32 reg_addr = cmd[offset] & desc->reg.mask;
1160 			const struct drm_i915_reg_descriptor *reg =
1161 				find_reg(engine, is_master, reg_addr);
1162 
1163 			if (!reg) {
1164 				DRM_DEBUG_DRIVER("CMD: Rejected register 0x%08X in command: 0x%08X (%s)\n",
1165 						 reg_addr, *cmd, engine->name);
1166 				return false;
1167 			}
1168 
1169 			/*
1170 			 * Check the value written to the register against the
1171 			 * allowed mask/value pair given in the whitelist entry.
1172 			 */
1173 			if (reg->mask) {
1174 				if (desc->cmd.value == MI_LOAD_REGISTER_MEM) {
1175 					DRM_DEBUG_DRIVER("CMD: Rejected LRM to masked register 0x%08X\n",
1176 							 reg_addr);
1177 					return false;
1178 				}
1179 
1180 				if (desc->cmd.value == MI_LOAD_REGISTER_REG) {
1181 					DRM_DEBUG_DRIVER("CMD: Rejected LRR to masked register 0x%08X\n",
1182 							 reg_addr);
1183 					return false;
1184 				}
1185 
1186 				if (desc->cmd.value == MI_LOAD_REGISTER_IMM(1) &&
1187 				    (offset + 2 > length ||
1188 				     (cmd[offset + 1] & reg->mask) != reg->value)) {
1189 					DRM_DEBUG_DRIVER("CMD: Rejected LRI to masked register 0x%08X\n",
1190 							 reg_addr);
1191 					return false;
1192 				}
1193 			}
1194 		}
1195 	}
1196 
1197 	if (desc->flags & CMD_DESC_BITMASK) {
1198 		int i;
1199 
1200 		for (i = 0; i < MAX_CMD_DESC_BITMASKS; i++) {
1201 			u32 dword;
1202 
1203 			if (desc->bits[i].mask == 0)
1204 				break;
1205 
1206 			if (desc->bits[i].condition_mask != 0) {
1207 				u32 offset =
1208 					desc->bits[i].condition_offset;
1209 				u32 condition = cmd[offset] &
1210 					desc->bits[i].condition_mask;
1211 
1212 				if (condition == 0)
1213 					continue;
1214 			}
1215 
1216 			if (desc->bits[i].offset >= length) {
1217 				DRM_DEBUG_DRIVER("CMD: Rejected command 0x%08X, too short to check bitmask (%s)\n",
1218 						 *cmd, engine->name);
1219 				return false;
1220 			}
1221 
1222 			dword = cmd[desc->bits[i].offset] &
1223 				desc->bits[i].mask;
1224 
1225 			if (dword != desc->bits[i].expected) {
1226 				DRM_DEBUG_DRIVER("CMD: Rejected command 0x%08X for bitmask 0x%08X (exp=0x%08X act=0x%08X) (%s)\n",
1227 						 *cmd,
1228 						 desc->bits[i].mask,
1229 						 desc->bits[i].expected,
1230 						 dword, engine->name);
1231 				return false;
1232 			}
1233 		}
1234 	}
1235 
1236 	return true;
1237 }
1238 
1239 #define LENGTH_BIAS 2
1240 
1241 /**
1242  * i915_parse_cmds() - parse a submitted batch buffer for privilege violations
1243  * @engine: the engine on which the batch is to execute
1244  * @batch_obj: the batch buffer in question
1245  * @shadow_batch_obj: copy of the batch buffer in question
1246  * @batch_start_offset: byte offset in the batch at which execution starts
1247  * @batch_len: length of the commands in batch_obj
1248  * @is_master: is the submitting process the drm master?
1249  *
1250  * Parses the specified batch buffer looking for privilege violations as
1251  * described in the overview.
1252  *
1253  * Return: non-zero if the parser finds violations or otherwise fails; -EACCES
1254  * if the batch appears legal but should use hardware parsing
1255  */
1256 int intel_engine_cmd_parser(struct intel_engine_cs *engine,
1257 			    struct drm_i915_gem_object *batch_obj,
1258 			    struct drm_i915_gem_object *shadow_batch_obj,
1259 			    u32 batch_start_offset,
1260 			    u32 batch_len,
1261 			    bool is_master)
1262 {
1263 	u32 *cmd, *batch_end;
1264 	struct drm_i915_cmd_descriptor default_desc = noop_desc;
1265 	const struct drm_i915_cmd_descriptor *desc = &default_desc;
1266 	bool needs_clflush_after = false;
1267 	int ret = 0;
1268 
1269 	cmd = copy_batch(shadow_batch_obj, batch_obj,
1270 			 batch_start_offset, batch_len,
1271 			 &needs_clflush_after);
1272 	if (IS_ERR(cmd)) {
1273 		DRM_DEBUG_DRIVER("CMD: Failed to copy batch\n");
1274 		return PTR_ERR(cmd);
1275 	}
1276 
1277 	/*
1278 	 * We use the batch length as size because the shadow object is as
1279 	 * large or larger and copy_batch() will write MI_NOPs to the extra
1280 	 * space. Parsing should be faster in some cases this way.
1281 	 */
1282 	batch_end = cmd + (batch_len / sizeof(*batch_end));
1283 	do {
1284 		u32 length;
1285 
1286 		if (*cmd == MI_BATCH_BUFFER_END) {
1287 			if (needs_clflush_after) {
1288 				void *ptr = page_mask_bits(shadow_batch_obj->mm.mapping);
1289 				drm_clflush_virt_range(ptr,
1290 						       (void *)(cmd + 1) - ptr);
1291 			}
1292 			break;
1293 		}
1294 
1295 		desc = find_cmd(engine, *cmd, desc, &default_desc);
1296 		if (!desc) {
1297 			DRM_DEBUG_DRIVER("CMD: Unrecognized command: 0x%08X\n",
1298 					 *cmd);
1299 			ret = -EINVAL;
1300 			break;
1301 		}
1302 
1303 		/*
1304 		 * If the batch buffer contains a chained batch, return an
1305 		 * error that tells the caller to abort and dispatch the
1306 		 * workload as a non-secure batch.
1307 		 */
1308 		if (desc->cmd.value == MI_BATCH_BUFFER_START) {
1309 			ret = -EACCES;
1310 			break;
1311 		}
1312 
1313 		if (desc->flags & CMD_DESC_FIXED)
1314 			length = desc->length.fixed;
1315 		else
1316 			length = ((*cmd & desc->length.mask) + LENGTH_BIAS);
1317 
1318 		if ((batch_end - cmd) < length) {
1319 			DRM_DEBUG_DRIVER("CMD: Command length exceeds batch length: 0x%08X length=%u batchlen=%td\n",
1320 					 *cmd,
1321 					 length,
1322 					 batch_end - cmd);
1323 			ret = -EINVAL;
1324 			break;
1325 		}
1326 
1327 		if (!check_cmd(engine, desc, cmd, length, is_master)) {
1328 			ret = -EACCES;
1329 			break;
1330 		}
1331 
1332 		cmd += length;
1333 		if  (cmd >= batch_end) {
1334 			DRM_DEBUG_DRIVER("CMD: Got to the end of the buffer w/o a BBE cmd!\n");
1335 			ret = -EINVAL;
1336 			break;
1337 		}
1338 	} while (1);
1339 
1340 	i915_gem_object_unpin_map(shadow_batch_obj);
1341 	return ret;
1342 }
1343 
1344 /**
1345  * i915_cmd_parser_get_version() - get the cmd parser version number
1346  * @dev_priv: i915 device private
1347  *
1348  * The cmd parser maintains a simple increasing integer version number suitable
1349  * for passing to userspace clients to determine what operations are permitted.
1350  *
1351  * Return: the current version number of the cmd parser
1352  */
1353 int i915_cmd_parser_get_version(struct drm_i915_private *dev_priv)
1354 {
1355 	struct intel_engine_cs *engine;
1356 	bool active = false;
1357 
1358 	/* If the command parser is not enabled, report 0 - unsupported */
1359 	for_each_uabi_engine(engine, dev_priv) {
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