kernel/drivers/gpu/drm/i915/i915_cmd_parser.c

   1 /*
   2  * Copyright © 2013 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  21  * IN THE SOFTWARE.
  22  *
  23  * Authors:
  24  *    Brad Volkin <bradley.d.volkin@intel.com>
  25  *
  26  */
  27
  28 #include "i915_drv.h"
  29
  30 /**
  31  * DOC: batch buffer command parser
  32  *
  33  * Motivation:
  34  * Certain OpenGL features (e.g. transform feedback, performance monitoring)
  35  * require userspace code to submit batches containing commands such as
  36  * MI_LOAD_REGISTER_IMM to access various registers. Unfortunately, some
  37  * generations of the hardware will noop these commands in "unsecure" batches
  38  * (which includes all userspace batches submitted via i915) even though the
  39  * commands may be safe and represent the intended programming model of the
  40  * device.
  41  *
  42  * The software command parser is similar in operation to the command parsing
  43  * done in hardware for unsecure batches. However, the software parser allows
  44  * some operations that would be noop'd by hardware, if the parser determines
  45  * the operation is safe, and submits the batch as "secure" to prevent hardware
  46  * parsing.
  47  *
  48  * Threats:
  49  * At a high level, the hardware (and software) checks attempt to prevent
  50  * granting userspace undue privileges. There are three categories of privilege.
  51  *
  52  * First, commands which are explicitly defined as privileged or which should
  53  * only be used by the kernel driver. The parser generally rejects such
  54  * commands, though it may allow some from the drm master process.
  55  *
  56  * Second, commands which access registers. To support correct/enhanced
  57  * userspace functionality, particularly certain OpenGL extensions, the parser
  58  * provides a whitelist of registers which userspace may safely access (for both
  59  * normal and drm master processes).
  60  *
  61  * Third, commands which access privileged memory (i.e. GGTT, HWS page, etc).
  62  * The parser always rejects such commands.
  63  *
  64  * The majority of the problematic commands fall in the MI_* range, with only a
  65  * few specific commands on each ring (e.g. PIPE_CONTROL and MI_FLUSH_DW).
  66  *
  67  * Implementation:
  68  * Each ring maintains tables of commands and registers which the parser uses in
  69  * scanning batch buffers submitted to that ring.
  70  *
  71  * Since the set of commands that the parser must check for is significantly
  72  * smaller than the number of commands supported, the parser tables contain only
  73  * those commands required by the parser. This generally works because command
  74  * opcode ranges have standard command length encodings. So for commands that
  75  * the parser does not need to check, it can easily skip them. This is
  76  * implemented via a per-ring length decoding vfunc.
  77  *
  78  * Unfortunately, there are a number of commands that do not follow the standard
  79  * length encoding for their opcode range, primarily amongst the MI_* commands.
  80  * To handle this, the parser provides a way to define explicit "skip" entries
  81  * in the per-ring command tables.
  82  *
  83  * Other command table entries map fairly directly to high level categories
  84  * mentioned above: rejected, master-only, register whitelist. The parser
  85  * implements a number of checks, including the privileged memory checks, via a
  86  * general bitmasking mechanism.
  87  */
  88
  89 #define STD_MI_OPCODE_MASK  0xFF800000
  90 #define STD_3D_OPCODE_MASK  0xFFFF0000
  91 #define STD_2D_OPCODE_MASK  0xFFC00000
  92 #define STD_MFX_OPCODE_MASK 0xFFFF0000
  93
  94 #define CMD(op, opm, f, lm, fl, ...)                            \
  95         {                                                       \
  96                 .flags = (fl) | ((f) ? CMD_DESC_FIXED : 0),     \
  97                 .cmd = { (op), (opm) },                         \
  98                 .length = { (lm) },                             \
  99                 __VA_ARGS__                                     \
 100         }
 101
 102 /* Convenience macros to compress the tables */
 103 #define SMI STD_MI_OPCODE_MASK
 104 #define S3D STD_3D_OPCODE_MASK
 105 #define S2D STD_2D_OPCODE_MASK
 106 #define SMFX STD_MFX_OPCODE_MASK
 107 #define F true
 108 #define S CMD_DESC_SKIP
 109 #define R CMD_DESC_REJECT
 110 #define W CMD_DESC_REGISTER
 111 #define B CMD_DESC_BITMASK
 112 #define M CMD_DESC_MASTER
 113
 114 /*            Command                          Mask   Fixed Len   Action
 115               ---------------------------------------------------------- */
 116 static const struct drm_i915_cmd_descriptor common_cmds[] = {
 117         CMD(  MI_NOOP,                          SMI,    F,  1,      S  ),
 118         CMD(  MI_USER_INTERRUPT,                SMI,    F,  1,      R  ),
 119         CMD(  MI_WAIT_FOR_EVENT,                SMI,    F,  1,      M  ),
 120         CMD(  MI_ARB_CHECK,                     SMI,    F,  1,      S  ),
 121         CMD(  MI_REPORT_HEAD,                   SMI,    F,  1,      S  ),
 122         CMD(  MI_SUSPEND_FLUSH,                 SMI,    F,  1,      S  ),
 123         CMD(  MI_SEMAPHORE_MBOX,                SMI,   !F,  0xFF,   R  ),
 124         CMD(  MI_STORE_DWORD_INDEX,             SMI,   !F,  0xFF,   R  ),
 125         CMD(  MI_LOAD_REGISTER_IMM(1),          SMI,   !F,  0xFF,   W,
 126               .reg = { .offset = 1, .mask = 0x007FFFFC, .step = 2 }    ),
 127         CMD(  MI_STORE_REGISTER_MEM,            SMI,    F,  3,     W | B,
 128               .reg = { .offset = 1, .mask = 0x007FFFFC },
 129               .bits = {{
 130                         .offset = 0,
 131                         .mask = MI_GLOBAL_GTT,
 132                         .expected = 0,
 133               }},                                                      ),
 134         CMD(  MI_LOAD_REGISTER_MEM,             SMI,    F,  3,     W | B,
 135               .reg = { .offset = 1, .mask = 0x007FFFFC },
 136               .bits = {{
 137                         .offset = 0,
 138                         .mask = MI_GLOBAL_GTT,
 139                         .expected = 0,
 140               }},                                                      ),
 141         /*
 142          * MI_BATCH_BUFFER_START requires some special handling. It's not
 143          * really a 'skip' action but it doesn't seem like it's worth adding
 144          * a new action. See i915_parse_cmds().
 145          */
 146         CMD(  MI_BATCH_BUFFER_START,            SMI,   !F,  0xFF,   S  ),
 147 };
 148
 149 static const struct drm_i915_cmd_descriptor render_cmds[] = {
 150         CMD(  MI_FLUSH,                         SMI,    F,  1,      S  ),
 151         CMD(  MI_ARB_ON_OFF,                    SMI,    F,  1,      R  ),
 152         CMD(  MI_PREDICATE,                     SMI,    F,  1,      S  ),
 153         CMD(  MI_TOPOLOGY_FILTER,               SMI,    F,  1,      S  ),
 154         CMD(  MI_SET_APPID,                     SMI,    F,  1,      S  ),
 155         CMD(  MI_DISPLAY_FLIP,                  SMI,   !F,  0xFF,   R  ),
 156         CMD(  MI_SET_CONTEXT,                   SMI,   !F,  0xFF,   R  ),
 157         CMD(  MI_URB_CLEAR,                     SMI,   !F,  0xFF,   S  ),
 158         CMD(  MI_STORE_DWORD_IMM,               SMI,   !F,  0x3F,   B,
 159               .bits = {{
 160                         .offset = 0,
 161                         .mask = MI_GLOBAL_GTT,
 162                         .expected = 0,
 163               }},                                                      ),
 164         CMD(  MI_UPDATE_GTT,                    SMI,   !F,  0xFF,   R  ),
 165         CMD(  MI_CLFLUSH,                       SMI,   !F,  0x3FF,  B,
 166               .bits = {{
 167                         .offset = 0,
 168                         .mask = MI_GLOBAL_GTT,
 169                         .expected = 0,
 170               }},                                                      ),
 171         CMD(  MI_REPORT_PERF_COUNT,             SMI,   !F,  0x3F,   B,
 172               .bits = {{
 173                         .offset = 1,
 174                         .mask = MI_REPORT_PERF_COUNT_GGTT,
 175                         .expected = 0,
 176               }},                                                      ),
 177         CMD(  MI_CONDITIONAL_BATCH_BUFFER_END,  SMI,   !F,  0xFF,   B,
 178               .bits = {{
 179                         .offset = 0,
 180                         .mask = MI_GLOBAL_GTT,
 181                         .expected = 0,
 182               }},                                                      ),
 183         CMD(  GFX_OP_3DSTATE_VF_STATISTICS,     S3D,    F,  1,      S  ),
 184         CMD(  PIPELINE_SELECT,                  S3D,    F,  1,      S  ),
 185         CMD(  MEDIA_VFE_STATE,                  S3D,   !F,  0xFFFF, B,
 186               .bits = {{
 187                         .offset = 2,
 188                         .mask = MEDIA_VFE_STATE_MMIO_ACCESS_MASK,
 189                         .expected = 0,
 190               }},                                                      ),
 191         CMD(  GPGPU_OBJECT,                     S3D,   !F,  0xFF,   S  ),
 192         CMD(  GPGPU_WALKER,                     S3D,   !F,  0xFF,   S  ),
 193         CMD(  GFX_OP_3DSTATE_SO_DECL_LIST,      S3D,   !F,  0x1FF,  S  ),
 194         CMD(  GFX_OP_PIPE_CONTROL(5),           S3D,   !F,  0xFF,   B,
 195               .bits = {{
 196                         .offset = 1,
 197                         .mask = (PIPE_CONTROL_MMIO_WRITE | PIPE_CONTROL_NOTIFY),
 198                         .expected = 0,
 199               },
 200               {
 201                         .offset = 1,
 202                         .mask = (PIPE_CONTROL_GLOBAL_GTT_IVB |
 203                                  PIPE_CONTROL_STORE_DATA_INDEX),
 204                         .expected = 0,
 205                         .condition_offset = 1,
 206                         .condition_mask = PIPE_CONTROL_POST_SYNC_OP_MASK,
 207               }},                                                      ),
 208 };
 209
 210 static const struct drm_i915_cmd_descriptor hsw_render_cmds[] = {
 211         CMD(  MI_SET_PREDICATE,                 SMI,    F,  1,      S  ),
 212         CMD(  MI_RS_CONTROL,                    SMI,    F,  1,      S  ),
 213         CMD(  MI_URB_ATOMIC_ALLOC,              SMI,    F,  1,      S  ),
 214         CMD(  MI_SET_APPID,                     SMI,    F,  1,      S  ),
 215         CMD(  MI_RS_CONTEXT,                    SMI,    F,  1,      S  ),
 216         CMD(  MI_LOAD_SCAN_LINES_INCL,          SMI,   !F,  0x3F,   M  ),
 217         CMD(  MI_LOAD_SCAN_LINES_EXCL,          SMI,   !F,  0x3F,   R  ),
 218         CMD(  MI_LOAD_REGISTER_REG,             SMI,   !F,  0xFF,   R  ),
 219         CMD(  MI_RS_STORE_DATA_IMM,             SMI,   !F,  0xFF,   S  ),
 220         CMD(  MI_LOAD_URB_MEM,                  SMI,   !F,  0xFF,   S  ),
 221         CMD(  MI_STORE_URB_MEM,                 SMI,   !F,  0xFF,   S  ),
 222         CMD(  GFX_OP_3DSTATE_DX9_CONSTANTF_VS,  S3D,   !F,  0x7FF,  S  ),
 223         CMD(  GFX_OP_3DSTATE_DX9_CONSTANTF_PS,  S3D,   !F,  0x7FF,  S  ),
 224
 225         CMD(  GFX_OP_3DSTATE_BINDING_TABLE_EDIT_VS,  S3D,   !F,  0x1FF,  S  ),
 226         CMD(  GFX_OP_3DSTATE_BINDING_TABLE_EDIT_GS,  S3D,   !F,  0x1FF,  S  ),
 227         CMD(  GFX_OP_3DSTATE_BINDING_TABLE_EDIT_HS,  S3D,   !F,  0x1FF,  S  ),
 228         CMD(  GFX_OP_3DSTATE_BINDING_TABLE_EDIT_DS,  S3D,   !F,  0x1FF,  S  ),
 229         CMD(  GFX_OP_3DSTATE_BINDING_TABLE_EDIT_PS,  S3D,   !F,  0x1FF,  S  ),
 230 };
 231
 232 static const struct drm_i915_cmd_descriptor video_cmds[] = {
 233         CMD(  MI_ARB_ON_OFF,                    SMI,    F,  1,      R  ),
 234         CMD(  MI_SET_APPID,                     SMI,    F,  1,      S  ),
 235         CMD(  MI_STORE_DWORD_IMM,               SMI,   !F,  0xFF,   B,
 236               .bits = {{
 237                         .offset = 0,
 238                         .mask = MI_GLOBAL_GTT,
 239                         .expected = 0,
 240               }},                                                      ),
 241         CMD(  MI_UPDATE_GTT,                    SMI,   !F,  0x3F,   R  ),
 242         CMD(  MI_FLUSH_DW,                      SMI,   !F,  0x3F,   B,
 243               .bits = {{
 244                         .offset = 0,
 245                         .mask = MI_FLUSH_DW_NOTIFY,
 246                         .expected = 0,
 247               },
 248               {
 249                         .offset = 1,
 250                         .mask = MI_FLUSH_DW_USE_GTT,
 251                         .expected = 0,
 252                         .condition_offset = 0,
 253                         .condition_mask = MI_FLUSH_DW_OP_MASK,
 254               },
 255               {
 256                         .offset = 0,
 257                         .mask = MI_FLUSH_DW_STORE_INDEX,
 258                         .expected = 0,
 259                         .condition_offset = 0,
 260                         .condition_mask = MI_FLUSH_DW_OP_MASK,
 261               }},                                                      ),
 262         CMD(  MI_CONDITIONAL_BATCH_BUFFER_END,  SMI,   !F,  0xFF,   B,
 263               .bits = {{
 264                         .offset = 0,
 265                         .mask = MI_GLOBAL_GTT,
 266                         .expected = 0,
 267               }},                                                      ),
 268         /*
 269          * MFX_WAIT doesn't fit the way we handle length for most commands.
 270          * It has a length field but it uses a non-standard length bias.
 271          * It is always 1 dword though, so just treat it as fixed length.
 272          */
 273         CMD(  MFX_WAIT,                         SMFX,   F,  1,      S  ),
 274 };
 275
 276 static const struct drm_i915_cmd_descriptor vecs_cmds[] = {
 277         CMD(  MI_ARB_ON_OFF,                    SMI,    F,  1,      R  ),
 278         CMD(  MI_SET_APPID,                     SMI,    F,  1,      S  ),
 279         CMD(  MI_STORE_DWORD_IMM,               SMI,   !F,  0xFF,   B,
 280               .bits = {{
 281                         .offset = 0,
 282                         .mask = MI_GLOBAL_GTT,
 283                         .expected = 0,
 284               }},                                                      ),
 285         CMD(  MI_UPDATE_GTT,                    SMI,   !F,  0x3F,   R  ),
 286         CMD(  MI_FLUSH_DW,                      SMI,   !F,  0x3F,   B,
 287               .bits = {{
 288                         .offset = 0,
 289                         .mask = MI_FLUSH_DW_NOTIFY,
 290                         .expected = 0,
 291               },
 292               {
 293                         .offset = 1,
 294                         .mask = MI_FLUSH_DW_USE_GTT,
 295                         .expected = 0,
 296                         .condition_offset = 0,
 297                         .condition_mask = MI_FLUSH_DW_OP_MASK,
 298               },
 299               {
 300                         .offset = 0,
 301                         .mask = MI_FLUSH_DW_STORE_INDEX,
 302                         .expected = 0,
 303                         .condition_offset = 0,
 304                         .condition_mask = MI_FLUSH_DW_OP_MASK,
 305               }},                                                      ),
 306         CMD(  MI_CONDITIONAL_BATCH_BUFFER_END,  SMI,   !F,  0xFF,   B,
 307               .bits = {{
 308                         .offset = 0,
 309                         .mask = MI_GLOBAL_GTT,
 310                         .expected = 0,
 311               }},                                                      ),
 312 };
 313
 314 static const struct drm_i915_cmd_descriptor blt_cmds[] = {
 315         CMD(  MI_DISPLAY_FLIP,                  SMI,   !F,  0xFF,   R  ),
 316         CMD(  MI_STORE_DWORD_IMM,               SMI,   !F,  0x3FF,  B,
 317               .bits = {{
 318                         .offset = 0,
 319                         .mask = MI_GLOBAL_GTT,
 320                         .expected = 0,
 321               }},                                                      ),
 322         CMD(  MI_UPDATE_GTT,                    SMI,   !F,  0x3F,   R  ),
 323         CMD(  MI_FLUSH_DW,                      SMI,   !F,  0x3F,   B,
 324               .bits = {{
 325                         .offset = 0,
 326                         .mask = MI_FLUSH_DW_NOTIFY,
 327                         .expected = 0,
 328               },
 329               {
 330                         .offset = 1,
 331                         .mask = MI_FLUSH_DW_USE_GTT,
 332                         .expected = 0,
 333                         .condition_offset = 0,
 334                         .condition_mask = MI_FLUSH_DW_OP_MASK,
 335               },
 336               {
 337                         .offset = 0,
 338                         .mask = MI_FLUSH_DW_STORE_INDEX,
 339                         .expected = 0,
 340                         .condition_offset = 0,
 341                         .condition_mask = MI_FLUSH_DW_OP_MASK,
 342               }},                                                      ),
 343         CMD(  COLOR_BLT,                        S2D,   !F,  0x3F,   S  ),
 344         CMD(  SRC_COPY_BLT,                     S2D,   !F,  0x3F,   S  ),
 345 };
 346
 347 static const struct drm_i915_cmd_descriptor hsw_blt_cmds[] = {
 348         CMD(  MI_LOAD_SCAN_LINES_INCL,          SMI,   !F,  0x3F,   M  ),
 349         CMD(  MI_LOAD_SCAN_LINES_EXCL,          SMI,   !F,  0x3F,   R  ),
 350 };
 351
 352 #undef CMD
 353 #undef SMI
 354 #undef S3D
 355 #undef S2D
 356 #undef SMFX
 357 #undef F
 358 #undef S
 359 #undef R
 360 #undef W
 361 #undef B
 362 #undef M
 363
 364 static const struct drm_i915_cmd_table gen7_render_cmds[] = {
 365         { common_cmds, ARRAY_SIZE(common_cmds) },
 366         { render_cmds, ARRAY_SIZE(render_cmds) },
 367 };
 368
 369 static const struct drm_i915_cmd_table hsw_render_ring_cmds[] = {
 370         { common_cmds, ARRAY_SIZE(common_cmds) },
 371         { render_cmds, ARRAY_SIZE(render_cmds) },
 372         { hsw_render_cmds, ARRAY_SIZE(hsw_render_cmds) },
 373 };
 374
 375 static const struct drm_i915_cmd_table gen7_video_cmds[] = {
 376         { common_cmds, ARRAY_SIZE(common_cmds) },
 377         { video_cmds, ARRAY_SIZE(video_cmds) },
 378 };
 379
 380 static const struct drm_i915_cmd_table hsw_vebox_cmds[] = {
 381         { common_cmds, ARRAY_SIZE(common_cmds) },
 382         { vecs_cmds, ARRAY_SIZE(vecs_cmds) },
 383 };
 384
 385 static const struct drm_i915_cmd_table gen7_blt_cmds[] = {
 386         { common_cmds, ARRAY_SIZE(common_cmds) },
 387         { blt_cmds, ARRAY_SIZE(blt_cmds) },
 388 };
 389
 390 static const struct drm_i915_cmd_table hsw_blt_ring_cmds[] = {
 391         { common_cmds, ARRAY_SIZE(common_cmds) },
 392         { blt_cmds, ARRAY_SIZE(blt_cmds) },
 393         { hsw_blt_cmds, ARRAY_SIZE(hsw_blt_cmds) },
 394 };
 395
 396 /*
 397  * Register whitelists, sorted by increasing register offset.
 398  */
 399
 400 /*
 401  * An individual whitelist entry granting access to register addr.  If
 402  * mask is non-zero the argument of immediate register writes will be
 403  * AND-ed with mask, and the command will be rejected if the result
 404  * doesn't match value.
 405  *
 406  * Registers with non-zero mask are only allowed to be written using
 407  * LRI.
 408  */
 409 struct drm_i915_reg_descriptor {
 410         u32 addr;
 411         u32 mask;
 412         u32 value;
 413 };
 414
 415 /* Convenience macro for adding 32-bit registers. */
 416 #define REG32(address, ...)                             \
 417         { .addr = address, __VA_ARGS__ }
 418
 419 /*
 420  * Convenience macro for adding 64-bit registers.
 421  *
 422  * Some registers that userspace accesses are 64 bits. The register
 423  * access commands only allow 32-bit accesses. Hence, we have to include
 424  * entries for both halves of the 64-bit registers.
 425  */
 426 #define REG64(addr)                                     \
 427         REG32(addr), REG32(addr + sizeof(u32))
 428
 429 static const struct drm_i915_reg_descriptor gen7_render_regs[] = {
 430         REG64(GPGPU_THREADS_DISPATCHED),
 431         REG64(HS_INVOCATION_COUNT),
 432         REG64(DS_INVOCATION_COUNT),
 433         REG64(IA_VERTICES_COUNT),
 434         REG64(IA_PRIMITIVES_COUNT),
 435         REG64(VS_INVOCATION_COUNT),
 436         REG64(GS_INVOCATION_COUNT),
 437         REG64(GS_PRIMITIVES_COUNT),
 438         REG64(CL_INVOCATION_COUNT),
 439         REG64(CL_PRIMITIVES_COUNT),
 440         REG64(PS_INVOCATION_COUNT),
 441         REG64(PS_DEPTH_COUNT),
 442         REG32(OACONTROL), /* Only allowed for LRI and SRM. See below. */
 443         REG64(MI_PREDICATE_SRC0),
 444         REG64(MI_PREDICATE_SRC1),
 445         REG32(GEN7_3DPRIM_END_OFFSET),
 446         REG32(GEN7_3DPRIM_START_VERTEX),
 447         REG32(GEN7_3DPRIM_VERTEX_COUNT),
 448         REG32(GEN7_3DPRIM_INSTANCE_COUNT),
 449         REG32(GEN7_3DPRIM_START_INSTANCE),
 450         REG32(GEN7_3DPRIM_BASE_VERTEX),
 451         REG32(GEN7_GPGPU_DISPATCHDIMX),
 452         REG32(GEN7_GPGPU_DISPATCHDIMY),
 453         REG32(GEN7_GPGPU_DISPATCHDIMZ),
 454         REG64(GEN7_SO_NUM_PRIMS_WRITTEN(0)),
 455         REG64(GEN7_SO_NUM_PRIMS_WRITTEN(1)),
 456         REG64(GEN7_SO_NUM_PRIMS_WRITTEN(2)),
 457         REG64(GEN7_SO_NUM_PRIMS_WRITTEN(3)),
 458         REG64(GEN7_SO_PRIM_STORAGE_NEEDED(0)),
 459         REG64(GEN7_SO_PRIM_STORAGE_NEEDED(1)),
 460         REG64(GEN7_SO_PRIM_STORAGE_NEEDED(2)),
 461         REG64(GEN7_SO_PRIM_STORAGE_NEEDED(3)),
 462         REG32(GEN7_SO_WRITE_OFFSET(0)),
 463         REG32(GEN7_SO_WRITE_OFFSET(1)),
 464         REG32(GEN7_SO_WRITE_OFFSET(2)),
 465         REG32(GEN7_SO_WRITE_OFFSET(3)),
 466         REG32(GEN7_L3SQCREG1),
 467         REG32(GEN7_L3CNTLREG2),
 468         REG32(GEN7_L3CNTLREG3),
 469         REG32(HSW_SCRATCH1,
 470               .mask = ~HSW_SCRATCH1_L3_DATA_ATOMICS_DISABLE,
 471               .value = 0),
 472         REG32(HSW_ROW_CHICKEN3,
 473               .mask = ~(HSW_ROW_CHICKEN3_L3_GLOBAL_ATOMICS_DISABLE << 16 |
 474                         HSW_ROW_CHICKEN3_L3_GLOBAL_ATOMICS_DISABLE),
 475               .value = 0),
 476 };
 477
 478 static const struct drm_i915_reg_descriptor gen7_blt_regs[] = {
 479         REG32(BCS_SWCTRL),
 480 };
 481
 482 static const struct drm_i915_reg_descriptor ivb_master_regs[] = {
 483         REG32(FORCEWAKE_MT),
 484         REG32(DERRMR),
 485         REG32(GEN7_PIPE_DE_LOAD_SL(PIPE_A)),
 486         REG32(GEN7_PIPE_DE_LOAD_SL(PIPE_B)),
 487         REG32(GEN7_PIPE_DE_LOAD_SL(PIPE_C)),
 488 };
 489
 490 static const struct drm_i915_reg_descriptor hsw_master_regs[] = {
 491         REG32(FORCEWAKE_MT),
 492         REG32(DERRMR),
 493 };
 494
 495 #undef REG64
 496 #undef REG32
 497
 498 static u32 gen7_render_get_cmd_length_mask(u32 cmd_header)
 499 {
 500         u32 client = (cmd_header & INSTR_CLIENT_MASK) >> INSTR_CLIENT_SHIFT;
 501         u32 subclient =
 502                 (cmd_header & INSTR_SUBCLIENT_MASK) >> INSTR_SUBCLIENT_SHIFT;
 503
 504         if (client == INSTR_MI_CLIENT)
 505                 return 0x3F;
 506         else if (client == INSTR_RC_CLIENT) {
 507                 if (subclient == INSTR_MEDIA_SUBCLIENT)
 508                         return 0xFFFF;
 509                 else
 510                         return 0xFF;
 511         }
 512
 513         DRM_DEBUG_DRIVER("CMD: Abnormal rcs cmd length! 0x%08X\n", cmd_header);
 514         return 0;
 515 }
 516
 517 static u32 gen7_bsd_get_cmd_length_mask(u32 cmd_header)
 518 {
 519         u32 client = (cmd_header & INSTR_CLIENT_MASK) >> INSTR_CLIENT_SHIFT;
 520         u32 subclient =
 521                 (cmd_header & INSTR_SUBCLIENT_MASK) >> INSTR_SUBCLIENT_SHIFT;
 522         u32 op = (cmd_header & INSTR_26_TO_24_MASK) >> INSTR_26_TO_24_SHIFT;
 523
 524         if (client == INSTR_MI_CLIENT)
 525                 return 0x3F;
 526         else if (client == INSTR_RC_CLIENT) {
 527                 if (subclient == INSTR_MEDIA_SUBCLIENT) {
 528                         if (op == 6)
 529                                 return 0xFFFF;
 530                         else
 531                                 return 0xFFF;
 532                 } else
 533                         return 0xFF;
 534         }
 535
 536         DRM_DEBUG_DRIVER("CMD: Abnormal bsd cmd length! 0x%08X\n", cmd_header);
 537         return 0;
 538 }
 539
 540 static u32 gen7_blt_get_cmd_length_mask(u32 cmd_header)
 541 {
 542         u32 client = (cmd_header & INSTR_CLIENT_MASK) >> INSTR_CLIENT_SHIFT;
 543
 544         if (client == INSTR_MI_CLIENT)
 545                 return 0x3F;
 546         else if (client == INSTR_BC_CLIENT)
 547                 return 0xFF;
 548
 549         DRM_DEBUG_DRIVER("CMD: Abnormal blt cmd length! 0x%08X\n", cmd_header);
 550         return 0;
 551 }
 552
 553 static bool validate_cmds_sorted(struct intel_engine_cs *ring,
 554                                  const struct drm_i915_cmd_table *cmd_tables,
 555                                  int cmd_table_count)
 556 {
 557         int i;
 558         bool ret = true;
 559
 560         if (!cmd_tables || cmd_table_count == 0)
 561                 return true;
 562
 563         for (i = 0; i < cmd_table_count; i++) {
 564                 const struct drm_i915_cmd_table *table = &cmd_tables[i];
 565                 u32 previous = 0;
 566                 int j;
 567
 568                 for (j = 0; j < table->count; j++) {
 569                         const struct drm_i915_cmd_descriptor *desc =
 570                                 &table->table[j];
 571                         u32 curr = desc->cmd.value & desc->cmd.mask;
 572
 573                         if (curr < previous) {
 574                                 DRM_ERROR("CMD: table not sorted ring=%d table=%d entry=%d cmd=0x%08X prev=0x%08X\n",
 575                                           ring->id, i, j, curr, previous);
 576                                 ret = false;
 577                         }
 578
 579                         previous = curr;
 580                 }
 581         }
 582
 583         return ret;
 584 }
 585
 586 static bool check_sorted(int ring_id,
 587                          const struct drm_i915_reg_descriptor *reg_table,
 588                          int reg_count)
 589 {
 590         int i;
 591         u32 previous = 0;
 592         bool ret = true;
 593
 594         for (i = 0; i < reg_count; i++) {
 595                 u32 curr = reg_table[i].addr;
 596
 597                 if (curr < previous) {
 598                         DRM_ERROR("CMD: table not sorted ring=%d entry=%d reg=0x%08X prev=0x%08X\n",
 599                                   ring_id, i, curr, previous);
 600                         ret = false;
 601                 }
 602
 603                 previous = curr;
 604         }
 605
 606         return ret;
 607 }
 608
 609 static bool validate_regs_sorted(struct intel_engine_cs *ring)
 610 {
 611         return check_sorted(ring->id, ring->reg_table, ring->reg_count) &&
 612                 check_sorted(ring->id, ring->master_reg_table,
 613                              ring->master_reg_count);
 614 }
 615
 616 struct cmd_node {
 617         const struct drm_i915_cmd_descriptor *desc;
 618         struct hlist_node node;
 619 };
 620
 621 /*
 622  * Different command ranges have different numbers of bits for the opcode. For
 623  * example, MI commands use bits 31:23 while 3D commands use bits 31:16. The
 624  * problem is that, for example, MI commands use bits 22:16 for other fields
 625  * such as GGTT vs PPGTT bits. If we include those bits in the mask then when
 626  * we mask a command from a batch it could hash to the wrong bucket due to
 627  * non-opcode bits being set. But if we don't include those bits, some 3D
 628  * commands may hash to the same bucket due to not including opcode bits that
 629  * make the command unique. For now, we will risk hashing to the same bucket.
 630  *
 631  * If we attempt to generate a perfect hash, we should be able to look at bits
 632  * 31:29 of a command from a batch buffer and use the full mask for that
 633  * client. The existing INSTR_CLIENT_MASK/SHIFT defines can be used for this.
 634  */
 635 #define CMD_HASH_MASK STD_MI_OPCODE_MASK
 636
 637 static int init_hash_table(struct intel_engine_cs *ring,
 638                            const struct drm_i915_cmd_table *cmd_tables,
 639                            int cmd_table_count)
 640 {
 641         int i, j;
 642
 643         hash_init(ring->cmd_hash);
 644
 645         for (i = 0; i < cmd_table_count; i++) {
 646                 const struct drm_i915_cmd_table *table = &cmd_tables[i];
 647
 648                 for (j = 0; j < table->count; j++) {
 649                         const struct drm_i915_cmd_descriptor *desc =
 650                                 &table->table[j];
 651                         struct cmd_node *desc_node =
 652                                 kmalloc(sizeof(*desc_node), GFP_KERNEL);
 653
 654                         if (!desc_node)
 655                                 return -ENOMEM;
 656
 657                         desc_node->desc = desc;
 658                         hash_add(ring->cmd_hash, &desc_node->node,
 659                                  desc->cmd.value & CMD_HASH_MASK);
 660                 }
 661         }
 662
 663         return 0;
 664 }
 665
 666 static void fini_hash_table(struct intel_engine_cs *ring)
 667 {
 668         struct hlist_node *tmp;
 669         struct cmd_node *desc_node;
 670         int i;
 671
 672         hash_for_each_safe(ring->cmd_hash, i, tmp, desc_node, node) {
 673                 hash_del(&desc_node->node);
 674                 kfree(desc_node);
 675         }
 676 }
 677
 678 /**
 679  * i915_cmd_parser_init_ring() - set cmd parser related fields for a ringbuffer
 680  * @ring: the ringbuffer to initialize
 681  *
 682  * Optionally initializes fields related to batch buffer command parsing in the
 683  * struct intel_engine_cs based on whether the platform requires software
 684  * command parsing.
 685  *
 686  * Return: non-zero if initialization fails
 687  */
 688 int i915_cmd_parser_init_ring(struct intel_engine_cs *ring)
 689 {
 690         const struct drm_i915_cmd_table *cmd_tables;
 691         int cmd_table_count;
 692         int ret;
 693
 694         if (!IS_GEN7(ring->dev))
 695                 return 0;
 696
 697         switch (ring->id) {
 698         case RCS:
 699                 if (IS_HASWELL(ring->dev)) {
 700                         cmd_tables = hsw_render_ring_cmds;
 701                         cmd_table_count =
 702                                 ARRAY_SIZE(hsw_render_ring_cmds);
 703                 } else {
 704                         cmd_tables = gen7_render_cmds;
 705                         cmd_table_count = ARRAY_SIZE(gen7_render_cmds);
 706                 }
 707
 708                 ring->reg_table = gen7_render_regs;
 709                 ring->reg_count = ARRAY_SIZE(gen7_render_regs);
 710
 711                 if (IS_HASWELL(ring->dev)) {
 712                         ring->master_reg_table = hsw_master_regs;
 713                         ring->master_reg_count = ARRAY_SIZE(hsw_master_regs);
 714                 } else {
 715                         ring->master_reg_table = ivb_master_regs;
 716                         ring->master_reg_count = ARRAY_SIZE(ivb_master_regs);
 717                 }
 718
 719                 ring->get_cmd_length_mask = gen7_render_get_cmd_length_mask;
 720                 break;
 721         case VCS:
 722                 cmd_tables = gen7_video_cmds;
 723                 cmd_table_count = ARRAY_SIZE(gen7_video_cmds);
 724                 ring->get_cmd_length_mask = gen7_bsd_get_cmd_length_mask;
 725                 break;
 726         case BCS:
 727                 if (IS_HASWELL(ring->dev)) {
 728                         cmd_tables = hsw_blt_ring_cmds;
 729                         cmd_table_count = ARRAY_SIZE(hsw_blt_ring_cmds);
 730                 } else {
 731                         cmd_tables = gen7_blt_cmds;
 732                         cmd_table_count = ARRAY_SIZE(gen7_blt_cmds);
 733                 }
 734
 735                 ring->reg_table = gen7_blt_regs;
 736                 ring->reg_count = ARRAY_SIZE(gen7_blt_regs);
 737
 738                 if (IS_HASWELL(ring->dev)) {
 739                         ring->master_reg_table = hsw_master_regs;
 740                         ring->master_reg_count = ARRAY_SIZE(hsw_master_regs);
 741                 } else {
 742                         ring->master_reg_table = ivb_master_regs;
 743                         ring->master_reg_count = ARRAY_SIZE(ivb_master_regs);
 744                 }
 745
 746                 ring->get_cmd_length_mask = gen7_blt_get_cmd_length_mask;
 747                 break;
 748         case VECS:
 749                 cmd_tables = hsw_vebox_cmds;
 750                 cmd_table_count = ARRAY_SIZE(hsw_vebox_cmds);
 751                 /* VECS can use the same length_mask function as VCS */
 752                 ring->get_cmd_length_mask = gen7_bsd_get_cmd_length_mask;
 753                 break;
 754         default:
 755                 DRM_ERROR("CMD: cmd_parser_init with unknown ring: %d\n",
 756                           ring->id);
 757                 BUG();
 758         }
 759
 760         BUG_ON(!validate_cmds_sorted(ring, cmd_tables, cmd_table_count));
 761         BUG_ON(!validate_regs_sorted(ring));
 762
 763         WARN_ON(!hash_empty(ring->cmd_hash));
 764
 765         ret = init_hash_table(ring, cmd_tables, cmd_table_count);
 766         if (ret) {
 767                 DRM_ERROR("CMD: cmd_parser_init failed!\n");
 768                 fini_hash_table(ring);
 769                 return ret;
 770         }
 771
 772         ring->needs_cmd_parser = true;
 773
 774         return 0;
 775 }
 776
 777 /**
 778  * i915_cmd_parser_fini_ring() - clean up cmd parser related fields
 779  * @ring: the ringbuffer to clean up
 780  *
 781  * Releases any resources related to command parsing that may have been
 782  * initialized for the specified ring.
 783  */
 784 void i915_cmd_parser_fini_ring(struct intel_engine_cs *ring)
 785 {
 786         if (!ring->needs_cmd_parser)
 787                 return;
 788
 789         fini_hash_table(ring);
 790 }
 791
 792 static const struct drm_i915_cmd_descriptor*
 793 find_cmd_in_table(struct intel_engine_cs *ring,
 794                   u32 cmd_header)
 795 {
 796         struct cmd_node *desc_node;
 797
 798         hash_for_each_possible(ring->cmd_hash, desc_node, node,
 799                                cmd_header & CMD_HASH_MASK) {
 800                 const struct drm_i915_cmd_descriptor *desc = desc_node->desc;
 801                 u32 masked_cmd = desc->cmd.mask & cmd_header;
 802                 u32 masked_value = desc->cmd.value & desc->cmd.mask;
 803
 804                 if (masked_cmd == masked_value)
 805                         return desc;
 806         }
 807
 808         return NULL;
 809 }
 810
 811 /*
 812  * Returns a pointer to a descriptor for the command specified by cmd_header.
 813  *
 814  * The caller must supply space for a default descriptor via the default_desc
 815  * parameter. If no descriptor for the specified command exists in the ring's
 816  * command parser tables, this function fills in default_desc based on the
 817  * ring's default length encoding and returns default_desc.
 818  */
 819 static const struct drm_i915_cmd_descriptor*
 820 find_cmd(struct intel_engine_cs *ring,
 821          u32 cmd_header,
 822          struct drm_i915_cmd_descriptor *default_desc)
 823 {
 824         const struct drm_i915_cmd_descriptor *desc;
 825         u32 mask;
 826
 827         desc = find_cmd_in_table(ring, cmd_header);
 828         if (desc)
 829                 return desc;
 830
 831         mask = ring->get_cmd_length_mask(cmd_header);
 832         if (!mask)
 833                 return NULL;
 834
 835         BUG_ON(!default_desc);
 836         default_desc->flags = CMD_DESC_SKIP;
 837         default_desc->length.mask = mask;
 838
 839         return default_desc;
 840 }
 841
 842 static const struct drm_i915_reg_descriptor *
 843 find_reg(const struct drm_i915_reg_descriptor *table,
 844          int count, u32 addr)
 845 {
 846         if (table) {
 847                 int i;
 848
 849                 for (i = 0; i < count; i++) {
 850                         if (table[i].addr == addr)
 851                                 return &table[i];
 852                 }
 853         }
 854
 855         return NULL;
 856 }
 857
 858 static u32 *vmap_batch(struct drm_i915_gem_object *obj,
 859                        unsigned start, unsigned len)
 860 {
 861         int i;
 862         void *addr = NULL;
 863         struct sg_page_iter sg_iter;
 864         int first_page = start >> PAGE_SHIFT;
 865         int last_page = (len + start + 4095) >> PAGE_SHIFT;
 866         int npages = last_page - first_page;
 867         struct page **pages;
 868
 869         pages = drm_malloc_ab(npages, sizeof(*pages));
 870         if (pages == NULL) {
 871                 DRM_DEBUG_DRIVER("Failed to get space for pages\n");
 872                 goto finish;
 873         }
 874
 875         i = 0;
 876         for_each_sg_page(obj->pages->sgl, &sg_iter, obj->pages->nents, first_page) {
 877                 pages[i++] = sg_page_iter_page(&sg_iter);
 878                 if (i == npages)
 879                         break;
 880         }
 881
 882         addr = vmap(pages, i, 0, PAGE_KERNEL);
 883         if (addr == NULL) {
 884                 DRM_DEBUG_DRIVER("Failed to vmap pages\n");
 885                 goto finish;
 886         }
 887
 888 finish:
 889         if (pages)
 890                 drm_free_large(pages);
 891         return (u32*)addr;
 892 }
 893
 894 /* Returns a vmap'd pointer to dest_obj, which the caller must unmap */
 895 static u32 *copy_batch(struct drm_i915_gem_object *dest_obj,
 896                        struct drm_i915_gem_object *src_obj,
 897                        u32 batch_start_offset,
 898                        u32 batch_len)
 899 {
 900         int needs_clflush = 0;
 901         void *src_base, *src;
 902         void *dst = NULL;
 903         int ret;
 904
 905         if (batch_len > dest_obj->base.size ||
 906             batch_len + batch_start_offset > src_obj->base.size)
 907                 return ERR_PTR(-E2BIG);
 908
 909         if (WARN_ON(dest_obj->pages_pin_count == 0))
 910                 return ERR_PTR(-ENODEV);
 911
 912         ret = i915_gem_obj_prepare_shmem_read(src_obj, &needs_clflush);
 913         if (ret) {
 914                 DRM_DEBUG_DRIVER("CMD: failed to prepare shadow batch\n");
 915                 return ERR_PTR(ret);
 916         }
 917
 918         src_base = vmap_batch(src_obj, batch_start_offset, batch_len);
 919         if (!src_base) {
 920                 DRM_DEBUG_DRIVER("CMD: Failed to vmap batch\n");
 921                 ret = -ENOMEM;
 922                 goto unpin_src;
 923         }
 924
 925         ret = i915_gem_object_set_to_cpu_domain(dest_obj, true);
 926         if (ret) {
 927                 DRM_DEBUG_DRIVER("CMD: Failed to set shadow batch to CPU\n");
 928                 goto unmap_src;
 929         }
 930
 931         dst = vmap_batch(dest_obj, 0, batch_len);
 932         if (!dst) {
 933                 DRM_DEBUG_DRIVER("CMD: Failed to vmap shadow batch\n");
 934                 ret = -ENOMEM;
 935                 goto unmap_src;
 936         }
 937
 938         src = src_base + offset_in_page(batch_start_offset);
 939         if (needs_clflush)
 940                 drm_clflush_virt_range(src, batch_len);
 941
 942         memcpy(dst, src, batch_len);
 943
 944 unmap_src:
 945         vunmap(src_base);
 946 unpin_src:
 947         i915_gem_object_unpin_pages(src_obj);
 948
 949         return ret ? ERR_PTR(ret) : dst;
 950 }
 951
 952 /**
 953  * i915_needs_cmd_parser() - should a given ring use software command parsing?
 954  * @ring: the ring in question
 955  *
 956  * Only certain platforms require software batch buffer command parsing, and
 957  * only when enabled via module parameter.
 958  *
 959  * Return: true if the ring requires software command parsing
 960  */
 961 bool i915_needs_cmd_parser(struct intel_engine_cs *ring)
 962 {
 963         if (!ring->needs_cmd_parser)
 964                 return false;
 965
 966         if (!USES_PPGTT(ring->dev))
 967                 return false;
 968
 969         return (i915.enable_cmd_parser == 1);
 970 }
 971
 972 static bool check_cmd(const struct intel_engine_cs *ring,
 973                       const struct drm_i915_cmd_descriptor *desc,
 974                       const u32 *cmd, u32 length,
 975                       const bool is_master,
 976                       bool *oacontrol_set)
 977 {
 978         if (desc->flags & CMD_DESC_REJECT) {
 979                 DRM_DEBUG_DRIVER("CMD: Rejected command: 0x%08X\n", *cmd);
 980                 return false;
 981         }
 982
 983         if ((desc->flags & CMD_DESC_MASTER) && !is_master) {
 984                 DRM_DEBUG_DRIVER("CMD: Rejected master-only command: 0x%08X\n",
 985                                  *cmd);
 986                 return false;
 987         }
 988
 989         if (desc->flags & CMD_DESC_REGISTER) {
 990                 /*
 991                  * Get the distance between individual register offset
 992                  * fields if the command can perform more than one
 993                  * access at a time.
 994                  */
 995                 const u32 step = desc->reg.step ? desc->reg.step : length;
 996                 u32 offset;
 997
 998                 for (offset = desc->reg.offset; offset < length;
 999                      offset += step) {
1000                         const u32 reg_addr = cmd[offset] & desc->reg.mask;
1001                         const struct drm_i915_reg_descriptor *reg =
1002                                 find_reg(ring->reg_table, ring->reg_count,
1003                                          reg_addr);
1004
1005                         if (!reg && is_master)
1006                                 reg = find_reg(ring->master_reg_table,
1007                                                ring->master_reg_count,
1008                                                reg_addr);
1009
1010                         if (!reg) {
1011                                 DRM_DEBUG_DRIVER("CMD: Rejected register 0x%08X in command: 0x%08X (ring=%d)\n",
1012                                                  reg_addr, *cmd, ring->id);
1013                                 return false;
1014                         }
1015
1016                         /*
1017                          * OACONTROL requires some special handling for
1018                          * writes. We want to make sure that any batch which
1019                          * enables OA also disables it before the end of the
1020                          * batch. The goal is to prevent one process from
1021                          * snooping on the perf data from another process. To do
1022                          * that, we need to check the value that will be written
1023                          * to the register. Hence, limit OACONTROL writes to
1024                          * only MI_LOAD_REGISTER_IMM commands.
1025                          */
1026                         if (reg_addr == OACONTROL) {
1027                                 if (desc->cmd.value == MI_LOAD_REGISTER_MEM) {
1028                                         DRM_DEBUG_DRIVER("CMD: Rejected LRM to OACONTROL\n");
1029                                         return false;
1030                                 }
1031
1032                                 if (desc->cmd.value == MI_LOAD_REGISTER_IMM(1))
1033                                         *oacontrol_set = (cmd[offset + 1] != 0);
1034                         }
1035
1036                         /*
1037                          * Check the value written to the register against the
1038                          * allowed mask/value pair given in the whitelist entry.
1039                          */
1040                         if (reg->mask) {
1041                                 if (desc->cmd.value == MI_LOAD_REGISTER_MEM) {
1042                                         DRM_DEBUG_DRIVER("CMD: Rejected LRM to masked register 0x%08X\n",
1043                                                          reg_addr);
1044                                         return false;
1045                                 }
1046
1047                                 if (desc->cmd.value == MI_LOAD_REGISTER_IMM(1) &&
1048                                     (offset + 2 > length ||
1049                                      (cmd[offset + 1] & reg->mask) != reg->value)) {
1050                                         DRM_DEBUG_DRIVER("CMD: Rejected LRI to masked register 0x%08X\n",
1051                                                          reg_addr);
1052                                         return false;
1053                                 }
1054                         }
1055                 }
1056         }
1057
1058         if (desc->flags & CMD_DESC_BITMASK) {
1059                 int i;
1060
1061                 for (i = 0; i < MAX_CMD_DESC_BITMASKS; i++) {
1062                         u32 dword;
1063
1064                         if (desc->bits[i].mask == 0)
1065                                 break;
1066
1067                         if (desc->bits[i].condition_mask != 0) {
1068                                 u32 offset =
1069                                         desc->bits[i].condition_offset;
1070                                 u32 condition = cmd[offset] &
1071                                         desc->bits[i].condition_mask;
1072
1073                                 if (condition == 0)
1074                                         continue;
1075                         }
1076
1077                         dword = cmd[desc->bits[i].offset] &
1078                                 desc->bits[i].mask;
1079
1080                         if (dword != desc->bits[i].expected) {
1081                                 DRM_DEBUG_DRIVER("CMD: Rejected command 0x%08X for bitmask 0x%08X (exp=0x%08X act=0x%08X) (ring=%d)\n",
1082                                                  *cmd,
1083                                                  desc->bits[i].mask,
1084                                                  desc->bits[i].expected,
1085                                                  dword, ring->id);
1086                                 return false;
1087                         }
1088                 }
1089         }
1090
1091         return true;
1092 }
1093
1094 #define LENGTH_BIAS 2
1095
1096 /**
1097  * i915_parse_cmds() - parse a submitted batch buffer for privilege violations
1098  * @ring: the ring on which the batch is to execute
1099  * @batch_obj: the batch buffer in question
1100  * @shadow_batch_obj: copy of the batch buffer in question
1101  * @batch_start_offset: byte offset in the batch at which execution starts
1102  * @batch_len: length of the commands in batch_obj
1103  * @is_master: is the submitting process the drm master?
1104  *
1105  * Parses the specified batch buffer looking for privilege violations as
1106  * described in the overview.
1107  *
1108  * Return: non-zero if the parser finds violations or otherwise fails; -EACCES
1109  * if the batch appears legal but should use hardware parsing
1110  */
1111 int i915_parse_cmds(struct intel_engine_cs *ring,
1112                     struct drm_i915_gem_object *batch_obj,
1113                     struct drm_i915_gem_object *shadow_batch_obj,
1114                     u32 batch_start_offset,
1115                     u32 batch_len,
1116                     bool is_master)
1117 {
1118         u32 *cmd, *batch_base, *batch_end;
1119         struct drm_i915_cmd_descriptor default_desc = { 0 };
1120         bool oacontrol_set = false; /* OACONTROL tracking. See check_cmd() */
1121         int ret = 0;
1122
1123         batch_base = copy_batch(shadow_batch_obj, batch_obj,
1124                                 batch_start_offset, batch_len);
1125         if (IS_ERR(batch_base)) {
1126                 DRM_DEBUG_DRIVER("CMD: Failed to copy batch\n");
1127                 return PTR_ERR(batch_base);
1128         }
1129
1130         /*
1131          * We use the batch length as size because the shadow object is as
1132          * large or larger and copy_batch() will write MI_NOPs to the extra
1133          * space. Parsing should be faster in some cases this way.
1134          */
1135         batch_end = batch_base + (batch_len / sizeof(*batch_end));
1136
1137         cmd = batch_base;
1138         while (cmd < batch_end) {
1139                 const struct drm_i915_cmd_descriptor *desc;
1140                 u32 length;
1141
1142                 if (*cmd == MI_BATCH_BUFFER_END)
1143                         break;
1144
1145                 desc = find_cmd(ring, *cmd, &default_desc);
1146                 if (!desc) {
1147                         DRM_DEBUG_DRIVER("CMD: Unrecognized command: 0x%08X\n",
1148                                          *cmd);
1149                         ret = -EINVAL;
1150                         break;
1151                 }
1152
1153                 /*
1154                  * If the batch buffer contains a chained batch, return an
1155                  * error that tells the caller to abort and dispatch the
1156                  * workload as a non-secure batch.
1157                  */
1158                 if (desc->cmd.value == MI_BATCH_BUFFER_START) {
1159                         ret = -EACCES;
1160                         break;
1161                 }
1162
1163                 if (desc->flags & CMD_DESC_FIXED)
1164                         length = desc->length.fixed;
1165                 else
1166                         length = ((*cmd & desc->length.mask) + LENGTH_BIAS);
1167
1168                 if ((batch_end - cmd) < length) {
1169                         DRM_DEBUG_DRIVER("CMD: Command length exceeds batch length: 0x%08X length=%u batchlen=%td\n",
1170                                          *cmd,
1171                                          length,
1172                                          batch_end - cmd);
1173                         ret = -EINVAL;
1174                         break;
1175                 }
1176
1177                 if (!check_cmd(ring, desc, cmd, length, is_master,
1178                                &oacontrol_set)) {
1179                         ret = -EINVAL;
1180                         break;
1181                 }
1182
1183                 cmd += length;
1184         }
1185
1186         if (oacontrol_set) {
1187                 DRM_DEBUG_DRIVER("CMD: batch set OACONTROL but did not clear it\n");
1188                 ret = -EINVAL;
1189         }
1190
1191         if (cmd >= batch_end) {
1192                 DRM_DEBUG_DRIVER("CMD: Got to the end of the buffer w/o a BBE cmd!\n");
1193                 ret = -EINVAL;
1194         }
1195
1196         vunmap(batch_base);
1197
1198         return ret;
1199 }
1200
1201 /**
1202  * i915_cmd_parser_get_version() - get the cmd parser version number
1203  *
1204  * The cmd parser maintains a simple increasing integer version number suitable
1205  * for passing to userspace clients to determine what operations are permitted.
1206  *
1207  * Return: the current version number of the cmd parser
1208  */
1209 int i915_cmd_parser_get_version(void)
1210 {
1211         /*
1212          * Command parser version history
1213          *
1214          * 1. Initial version. Checks batches and reports violations, but leaves
1215          *    hardware parsing enabled (so does not allow new use cases).
1216          * 2. Allow access to the MI_PREDICATE_SRC0 and
1217          *    MI_PREDICATE_SRC1 registers.
1218          * 3. Allow access to the GPGPU_THREADS_DISPATCHED register.
1219          * 4. L3 atomic chicken bits of HSW_SCRATCH1 and HSW_ROW_CHICKEN3.
1220          * 5. GPGPU dispatch compute indirect registers.
1221          */
1222         return 5;
1223 }