src/mesa/drivers/dri/i965/brw_pipe_control.c

   1 /*
   2  * Copyright © 2010 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
  24 #include "brw_context.h"
  25 #include "intel_batchbuffer.h"
  26 #include "intel_fbo.h"
  27 #include "intel_reg.h"
  28
  29 /**
  30  * According to the latest documentation, any PIPE_CONTROL with the
  31  * "Command Streamer Stall" bit set must also have another bit set,
  32  * with five different options:
  33  *
  34  *  - Render Target Cache Flush
  35  *  - Depth Cache Flush
  36  *  - Stall at Pixel Scoreboard
  37  *  - Post-Sync Operation
  38  *  - Depth Stall
  39  *
  40  * I chose "Stall at Pixel Scoreboard" since we've used it effectively
  41  * in the past, but the choice is fairly arbitrary.
  42  */
  43 static void
  44 gen8_add_cs_stall_workaround_bits(uint32_t *flags)
  45 {
  46    uint32_t wa_bits = PIPE_CONTROL_RENDER_TARGET_FLUSH |
  47                       PIPE_CONTROL_DEPTH_CACHE_FLUSH |
  48                       PIPE_CONTROL_WRITE_IMMEDIATE |
  49                       PIPE_CONTROL_WRITE_DEPTH_COUNT |
  50                       PIPE_CONTROL_WRITE_TIMESTAMP |
  51                       PIPE_CONTROL_STALL_AT_SCOREBOARD |
  52                       PIPE_CONTROL_DEPTH_STALL;
  53
  54    /* If we're doing a CS stall, and don't already have one of the
  55     * workaround bits set, add "Stall at Pixel Scoreboard."
  56     */
  57    if ((*flags & PIPE_CONTROL_CS_STALL) != 0 && (*flags & wa_bits) == 0)
  58       *flags |= PIPE_CONTROL_STALL_AT_SCOREBOARD;
  59 }
  60
  61 /* Implement the WaCsStallAtEveryFourthPipecontrol workaround on IVB, BYT:
  62  *
  63  * "Every 4th PIPE_CONTROL command, not counting the PIPE_CONTROL with
  64  *  only read-cache-invalidate bit(s) set, must have a CS_STALL bit set."
  65  *
  66  * Note that the kernel does CS stalls between batches, so we only need
  67  * to count them within a batch.
  68  */
  69 static uint32_t
  70 gen7_cs_stall_every_four_pipe_controls(struct brw_context *brw, uint32_t flags)
  71 {
  72    if (brw->gen == 7 && !brw->is_haswell) {
  73       if (flags & PIPE_CONTROL_CS_STALL) {
  74          /* If we're doing a CS stall, reset the counter and carry on. */
  75          brw->pipe_controls_since_last_cs_stall = 0;
  76          return 0;
  77       }
  78
  79       /* If this is the fourth pipe control without a CS stall, do one now. */
  80       if (++brw->pipe_controls_since_last_cs_stall == 4) {
  81          brw->pipe_controls_since_last_cs_stall = 0;
  82          return PIPE_CONTROL_CS_STALL;
  83       }
  84    }
  85    return 0;
  86 }
  87
  88 /**
  89  * Emit a PIPE_CONTROL with various flushing flags.
  90  *
  91  * The caller is responsible for deciding what flags are appropriate for the
  92  * given generation.
  93  */
  94 void
  95 brw_emit_pipe_control_flush(struct brw_context *brw, uint32_t flags)
  96 {
  97    if (brw->gen >= 8) {
  98       gen8_add_cs_stall_workaround_bits(&flags);
  99
 100       BEGIN_BATCH(6);
 101       OUT_BATCH(_3DSTATE_PIPE_CONTROL | (6 - 2));
 102       OUT_BATCH(flags);
 103       OUT_BATCH(0);
 104       OUT_BATCH(0);
 105       OUT_BATCH(0);
 106       OUT_BATCH(0);
 107       ADVANCE_BATCH();
 108    } else if (brw->gen >= 6) {
 109       flags |= gen7_cs_stall_every_four_pipe_controls(brw, flags);
 110
 111       BEGIN_BATCH(5);
 112       OUT_BATCH(_3DSTATE_PIPE_CONTROL | (5 - 2));
 113       OUT_BATCH(flags);
 114       OUT_BATCH(0);
 115       OUT_BATCH(0);
 116       OUT_BATCH(0);
 117       ADVANCE_BATCH();
 118    } else {
 119       BEGIN_BATCH(4);
 120       OUT_BATCH(_3DSTATE_PIPE_CONTROL | flags | (4 - 2));
 121       OUT_BATCH(0);
 122       OUT_BATCH(0);
 123       OUT_BATCH(0);
 124       ADVANCE_BATCH();
 125    }
 126 }
 127
 128 /**
 129  * Emit a PIPE_CONTROL that writes to a buffer object.
 130  *
 131  * \p flags should contain one of the following items:
 132  *  - PIPE_CONTROL_WRITE_IMMEDIATE
 133  *  - PIPE_CONTROL_WRITE_TIMESTAMP
 134  *  - PIPE_CONTROL_WRITE_DEPTH_COUNT
 135  */
 136 void
 137 brw_emit_pipe_control_write(struct brw_context *brw, uint32_t flags,
 138                             drm_intel_bo *bo, uint32_t offset,
 139                             uint32_t imm_lower, uint32_t imm_upper)
 140 {
 141    if (brw->gen >= 8) {
 142       gen8_add_cs_stall_workaround_bits(&flags);
 143
 144       BEGIN_BATCH(6);
 145       OUT_BATCH(_3DSTATE_PIPE_CONTROL | (6 - 2));
 146       OUT_BATCH(flags);
 147       OUT_RELOC64(bo, I915_GEM_DOMAIN_INSTRUCTION, I915_GEM_DOMAIN_INSTRUCTION,
 148                   offset);
 149       OUT_BATCH(imm_lower);
 150       OUT_BATCH(imm_upper);
 151       ADVANCE_BATCH();
 152    } else if (brw->gen >= 6) {
 153       flags |= gen7_cs_stall_every_four_pipe_controls(brw, flags);
 154
 155       /* PPGTT/GGTT is selected by DW2 bit 2 on Sandybridge, but DW1 bit 24
 156        * on later platforms.  We always use PPGTT on Gen7+.
 157        */
 158       unsigned gen6_gtt = brw->gen == 6 ? PIPE_CONTROL_GLOBAL_GTT_WRITE : 0;
 159
 160       BEGIN_BATCH(5);
 161       OUT_BATCH(_3DSTATE_PIPE_CONTROL | (5 - 2));
 162       OUT_BATCH(flags);
 163       OUT_RELOC(bo, I915_GEM_DOMAIN_INSTRUCTION, I915_GEM_DOMAIN_INSTRUCTION,
 164                 gen6_gtt | offset);
 165       OUT_BATCH(imm_lower);
 166       OUT_BATCH(imm_upper);
 167       ADVANCE_BATCH();
 168    } else {
 169       BEGIN_BATCH(4);
 170       OUT_BATCH(_3DSTATE_PIPE_CONTROL | flags | (4 - 2));
 171       OUT_RELOC(bo, I915_GEM_DOMAIN_INSTRUCTION, I915_GEM_DOMAIN_INSTRUCTION,
 172                 PIPE_CONTROL_GLOBAL_GTT_WRITE | offset);
 173       OUT_BATCH(imm_lower);
 174       OUT_BATCH(imm_upper);
 175       ADVANCE_BATCH();
 176    }
 177 }
 178
 179 /**
 180  * Restriction [DevSNB, DevIVB]:
 181  *
 182  * Prior to changing Depth/Stencil Buffer state (i.e. any combination of
 183  * 3DSTATE_DEPTH_BUFFER, 3DSTATE_CLEAR_PARAMS, 3DSTATE_STENCIL_BUFFER,
 184  * 3DSTATE_HIER_DEPTH_BUFFER) SW must first issue a pipelined depth stall
 185  * (PIPE_CONTROL with Depth Stall bit set), followed by a pipelined depth
 186  * cache flush (PIPE_CONTROL with Depth Flush Bit set), followed by
 187  * another pipelined depth stall (PIPE_CONTROL with Depth Stall bit set),
 188  * unless SW can otherwise guarantee that the pipeline from WM onwards is
 189  * already flushed (e.g., via a preceding MI_FLUSH).
 190  */
 191 void
 192 brw_emit_depth_stall_flushes(struct brw_context *brw)
 193 {
 194    assert(brw->gen >= 6 && brw->gen <= 9);
 195
 196    /* Starting on BDW, these pipe controls are unnecessary.
 197     *
 198     *   WM HW will internally manage the draining pipe and flushing of the caches
 199     *   when this command is issued. The PIPE_CONTROL restrictions are removed.
 200     */
 201    if (brw->gen >= 8)
 202       return;
 203
 204    brw_emit_pipe_control_flush(brw, PIPE_CONTROL_DEPTH_STALL);
 205    brw_emit_pipe_control_flush(brw, PIPE_CONTROL_DEPTH_CACHE_FLUSH);
 206    brw_emit_pipe_control_flush(brw, PIPE_CONTROL_DEPTH_STALL);
 207 }
 208
 209 /**
 210  * From the Ivybridge PRM, Volume 2 Part 1, Section 3.2 (VS Stage Input):
 211  * "A PIPE_CONTROL with Post-Sync Operation set to 1h and a depth
 212  *  stall needs to be sent just prior to any 3DSTATE_VS, 3DSTATE_URB_VS,
 213  *  3DSTATE_CONSTANT_VS, 3DSTATE_BINDING_TABLE_POINTER_VS,
 214  *  3DSTATE_SAMPLER_STATE_POINTER_VS command.  Only one PIPE_CONTROL needs
 215  *  to be sent before any combination of VS associated 3DSTATE."
 216  */
 217 void
 218 gen7_emit_vs_workaround_flush(struct brw_context *brw)
 219 {
 220    assert(brw->gen == 7);
 221    brw_emit_pipe_control_write(brw,
 222                                PIPE_CONTROL_WRITE_IMMEDIATE
 223                                | PIPE_CONTROL_DEPTH_STALL,
 224                                brw->workaround_bo, 0,
 225                                0, 0);
 226 }
 227
 228
 229 /**
 230  * Emit a PIPE_CONTROL command for gen7 with the CS Stall bit set.
 231  */
 232 void
 233 gen7_emit_cs_stall_flush(struct brw_context *brw)
 234 {
 235    brw_emit_pipe_control_write(brw,
 236                                PIPE_CONTROL_CS_STALL
 237                                | PIPE_CONTROL_WRITE_IMMEDIATE,
 238                                brw->workaround_bo, 0,
 239                                0, 0);
 240 }
 241
 242
 243 /**
 244  * Emits a PIPE_CONTROL with a non-zero post-sync operation, for
 245  * implementing two workarounds on gen6.  From section 1.4.7.1
 246  * "PIPE_CONTROL" of the Sandy Bridge PRM volume 2 part 1:
 247  *
 248  * [DevSNB-C+{W/A}] Before any depth stall flush (including those
 249  * produced by non-pipelined state commands), software needs to first
 250  * send a PIPE_CONTROL with no bits set except Post-Sync Operation !=
 251  * 0.
 252  *
 253  * [Dev-SNB{W/A}]: Before a PIPE_CONTROL with Write Cache Flush Enable
 254  * =1, a PIPE_CONTROL with any non-zero post-sync-op is required.
 255  *
 256  * And the workaround for these two requires this workaround first:
 257  *
 258  * [Dev-SNB{W/A}]: Pipe-control with CS-stall bit set must be sent
 259  * BEFORE the pipe-control with a post-sync op and no write-cache
 260  * flushes.
 261  *
 262  * And this last workaround is tricky because of the requirements on
 263  * that bit.  From section 1.4.7.2.3 "Stall" of the Sandy Bridge PRM
 264  * volume 2 part 1:
 265  *
 266  *     "1 of the following must also be set:
 267  *      - Render Target Cache Flush Enable ([12] of DW1)
 268  *      - Depth Cache Flush Enable ([0] of DW1)
 269  *      - Stall at Pixel Scoreboard ([1] of DW1)
 270  *      - Depth Stall ([13] of DW1)
 271  *      - Post-Sync Operation ([13] of DW1)
 272  *      - Notify Enable ([8] of DW1)"
 273  *
 274  * The cache flushes require the workaround flush that triggered this
 275  * one, so we can't use it.  Depth stall would trigger the same.
 276  * Post-sync nonzero is what triggered this second workaround, so we
 277  * can't use that one either.  Notify enable is IRQs, which aren't
 278  * really our business.  That leaves only stall at scoreboard.
 279  */
 280 void
 281 brw_emit_post_sync_nonzero_flush(struct brw_context *brw)
 282 {
 283    brw_emit_pipe_control_flush(brw,
 284                                PIPE_CONTROL_CS_STALL |
 285                                PIPE_CONTROL_STALL_AT_SCOREBOARD);
 286
 287    brw_emit_pipe_control_write(brw, PIPE_CONTROL_WRITE_IMMEDIATE,
 288                                brw->workaround_bo, 0, 0, 0);
 289 }
 290
 291 /* Emit a pipelined flush to either flush render and texture cache for
 292  * reading from a FBO-drawn texture, or flush so that frontbuffer
 293  * render appears on the screen in DRI1.
 294  *
 295  * This is also used for the always_flush_cache driconf debug option.
 296  */
 297 void
 298 brw_emit_mi_flush(struct brw_context *brw)
 299 {
 300    if (brw->batch.ring == BLT_RING && brw->gen >= 6) {
 301       BEGIN_BATCH_BLT(4);
 302       OUT_BATCH(MI_FLUSH_DW);
 303       OUT_BATCH(0);
 304       OUT_BATCH(0);
 305       OUT_BATCH(0);
 306       ADVANCE_BATCH();
 307    } else {
 308       int flags = PIPE_CONTROL_NO_WRITE | PIPE_CONTROL_RENDER_TARGET_FLUSH;
 309       if (brw->gen >= 6) {
 310          if (brw->gen == 9) {
 311             /* Hardware workaround: SKL
 312              *
 313              * Emit Pipe Control with all bits set to zero before emitting
 314              * a Pipe Control with VF Cache Invalidate set.
 315              */
 316             brw_emit_pipe_control_flush(brw, 0);
 317          }
 318
 319          flags |= PIPE_CONTROL_INSTRUCTION_INVALIDATE |
 320                   PIPE_CONTROL_DEPTH_CACHE_FLUSH |
 321                   PIPE_CONTROL_VF_CACHE_INVALIDATE |
 322                   PIPE_CONTROL_TEXTURE_CACHE_INVALIDATE |
 323                   PIPE_CONTROL_CS_STALL;
 324
 325          if (brw->gen == 6) {
 326             /* Hardware workaround: SNB B-Spec says:
 327              *
 328              * [Dev-SNB{W/A}]: Before a PIPE_CONTROL with Write Cache
 329              * Flush Enable =1, a PIPE_CONTROL with any non-zero
 330              * post-sync-op is required.
 331              */
 332             brw_emit_post_sync_nonzero_flush(brw);
 333          }
 334       }
 335       brw_emit_pipe_control_flush(brw, flags);
 336    }
 337
 338    brw_render_cache_set_clear(brw);
 339 }
 340
 341 int
 342 brw_init_pipe_control(struct brw_context *brw,
 343                       const struct brw_device_info *devinfo)
 344 {
 345    if (devinfo->gen < 6)
 346       return 0;
 347
 348    /* We can't just use brw_state_batch to get a chunk of space for
 349     * the gen6 workaround because it involves actually writing to
 350     * the buffer, and the kernel doesn't let us write to the batch.
 351     */
 352    brw->workaround_bo = drm_intel_bo_alloc(brw->bufmgr,
 353                                            "pipe_control workaround",
 354                                            4096, 4096);
 355    if (brw->workaround_bo == NULL)
 356       return -ENOMEM;
 357
 358    brw->pipe_controls_since_last_cs_stall = 0;
 359
 360    return 0;
 361 }
 362
 363 void
 364 brw_fini_pipe_control(struct brw_context *brw)
 365 {
 366    drm_intel_bo_unreference(brw->workaround_bo);
 367 }