drivers/gpu/drm/i915/intel_guc_ct.c

   1 /*
   2  * Copyright © 2016-2017 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 "i915_drv.h"
  25 #include "intel_guc_ct.h"
  26
  27 enum { CTB_SEND = 0, CTB_RECV = 1 };
  28
  29 enum { CTB_OWNER_HOST = 0 };
  30
  31 void intel_guc_ct_init_early(struct intel_guc_ct *ct)
  32 {
  33         /* we're using static channel owners */
  34         ct->host_channel.owner = CTB_OWNER_HOST;
  35 }
  36
  37 static inline const char *guc_ct_buffer_type_to_str(u32 type)
  38 {
  39         switch (type) {
  40         case INTEL_GUC_CT_BUFFER_TYPE_SEND:
  41                 return "SEND";
  42         case INTEL_GUC_CT_BUFFER_TYPE_RECV:
  43                 return "RECV";
  44         default:
  45                 return "<invalid>";
  46         }
  47 }
  48
  49 static void guc_ct_buffer_desc_init(struct guc_ct_buffer_desc *desc,
  50                                     u32 cmds_addr, u32 size, u32 owner)
  51 {
  52         DRM_DEBUG_DRIVER("CT: desc %p init addr=%#x size=%u owner=%u\n",
  53                          desc, cmds_addr, size, owner);
  54         memset(desc, 0, sizeof(*desc));
  55         desc->addr = cmds_addr;
  56         desc->size = size;
  57         desc->owner = owner;
  58 }
  59
  60 static void guc_ct_buffer_desc_reset(struct guc_ct_buffer_desc *desc)
  61 {
  62         DRM_DEBUG_DRIVER("CT: desc %p reset head=%u tail=%u\n",
  63                          desc, desc->head, desc->tail);
  64         desc->head = 0;
  65         desc->tail = 0;
  66         desc->is_in_error = 0;
  67 }
  68
  69 static int guc_action_register_ct_buffer(struct intel_guc *guc,
  70                                          u32 desc_addr,
  71                                          u32 type)
  72 {
  73         u32 action[] = {
  74                 INTEL_GUC_ACTION_REGISTER_COMMAND_TRANSPORT_BUFFER,
  75                 desc_addr,
  76                 sizeof(struct guc_ct_buffer_desc),
  77                 type
  78         };
  79         int err;
  80
  81         /* Can't use generic send(), CT registration must go over MMIO */
  82         err = intel_guc_send_mmio(guc, action, ARRAY_SIZE(action));
  83         if (err)
  84                 DRM_ERROR("CT: register %s buffer failed; err=%d\n",
  85                           guc_ct_buffer_type_to_str(type), err);
  86         return err;
  87 }
  88
  89 static int guc_action_deregister_ct_buffer(struct intel_guc *guc,
  90                                            u32 owner,
  91                                            u32 type)
  92 {
  93         u32 action[] = {
  94                 INTEL_GUC_ACTION_DEREGISTER_COMMAND_TRANSPORT_BUFFER,
  95                 owner,
  96                 type
  97         };
  98         int err;
  99
 100         /* Can't use generic send(), CT deregistration must go over MMIO */
 101         err = intel_guc_send_mmio(guc, action, ARRAY_SIZE(action));
 102         if (err)
 103                 DRM_ERROR("CT: deregister %s buffer failed; owner=%d err=%d\n",
 104                           guc_ct_buffer_type_to_str(type), owner, err);
 105         return err;
 106 }
 107
 108 static bool ctch_is_open(struct intel_guc_ct_channel *ctch)
 109 {
 110         return ctch->vma != NULL;
 111 }
 112
 113 static int ctch_init(struct intel_guc *guc,
 114                      struct intel_guc_ct_channel *ctch)
 115 {
 116         struct i915_vma *vma;
 117         void *blob;
 118         int err;
 119         int i;
 120
 121         GEM_BUG_ON(ctch->vma);
 122
 123         /* We allocate 1 page to hold both descriptors and both buffers.
 124          *       ___________.....................
 125          *      |desc (SEND)|                   :
 126          *      |___________|                   PAGE/4
 127          *      :___________....................:
 128          *      |desc (RECV)|                   :
 129          *      |___________|                   PAGE/4
 130          *      :_______________________________:
 131          *      |cmds (SEND)                    |
 132          *      |                               PAGE/4
 133          *      |_______________________________|
 134          *      |cmds (RECV)                    |
 135          *      |                               PAGE/4
 136          *      |_______________________________|
 137          *
 138          * Each message can use a maximum of 32 dwords and we don't expect to
 139          * have more than 1 in flight at any time, so we have enough space.
 140          * Some logic further ahead will rely on the fact that there is only 1
 141          * page and that it is always mapped, so if the size is changed the
 142          * other code will need updating as well.
 143          */
 144
 145         /* allocate vma */
 146         vma = intel_guc_allocate_vma(guc, PAGE_SIZE);
 147         if (IS_ERR(vma)) {
 148                 err = PTR_ERR(vma);
 149                 goto err_out;
 150         }
 151         ctch->vma = vma;
 152
 153         /* map first page */
 154         blob = i915_gem_object_pin_map(vma->obj, I915_MAP_WB);
 155         if (IS_ERR(blob)) {
 156                 err = PTR_ERR(blob);
 157                 goto err_vma;
 158         }
 159         DRM_DEBUG_DRIVER("CT: vma base=%#x\n", guc_ggtt_offset(ctch->vma));
 160
 161         /* store pointers to desc and cmds */
 162         for (i = 0; i < ARRAY_SIZE(ctch->ctbs); i++) {
 163                 GEM_BUG_ON((i != CTB_SEND) && (i != CTB_RECV));
 164                 ctch->ctbs[i].desc = blob + PAGE_SIZE/4 * i;
 165                 ctch->ctbs[i].cmds = blob + PAGE_SIZE/4 * i + PAGE_SIZE/2;
 166         }
 167
 168         return 0;
 169
 170 err_vma:
 171         i915_vma_unpin_and_release(&ctch->vma);
 172 err_out:
 173         DRM_DEBUG_DRIVER("CT: channel %d initialization failed; err=%d\n",
 174                          ctch->owner, err);
 175         return err;
 176 }
 177
 178 static void ctch_fini(struct intel_guc *guc,
 179                       struct intel_guc_ct_channel *ctch)
 180 {
 181         GEM_BUG_ON(!ctch->vma);
 182
 183         i915_gem_object_unpin_map(ctch->vma->obj);
 184         i915_vma_unpin_and_release(&ctch->vma);
 185 }
 186
 187 static int ctch_open(struct intel_guc *guc,
 188                      struct intel_guc_ct_channel *ctch)
 189 {
 190         u32 base;
 191         int err;
 192         int i;
 193
 194         DRM_DEBUG_DRIVER("CT: channel %d reopen=%s\n",
 195                          ctch->owner, yesno(ctch_is_open(ctch)));
 196
 197         if (!ctch->vma) {
 198                 err = ctch_init(guc, ctch);
 199                 if (unlikely(err))
 200                         goto err_out;
 201                 GEM_BUG_ON(!ctch->vma);
 202         }
 203
 204         /* vma should be already allocated and map'ed */
 205         base = guc_ggtt_offset(ctch->vma);
 206
 207         /* (re)initialize descriptors
 208          * cmds buffers are in the second half of the blob page
 209          */
 210         for (i = 0; i < ARRAY_SIZE(ctch->ctbs); i++) {
 211                 GEM_BUG_ON((i != CTB_SEND) && (i != CTB_RECV));
 212                 guc_ct_buffer_desc_init(ctch->ctbs[i].desc,
 213                                         base + PAGE_SIZE/4 * i + PAGE_SIZE/2,
 214                                         PAGE_SIZE/4,
 215                                         ctch->owner);
 216         }
 217
 218         /* register buffers, starting wirh RECV buffer
 219          * descriptors are in first half of the blob
 220          */
 221         err = guc_action_register_ct_buffer(guc,
 222                                             base + PAGE_SIZE/4 * CTB_RECV,
 223                                             INTEL_GUC_CT_BUFFER_TYPE_RECV);
 224         if (unlikely(err))
 225                 goto err_fini;
 226
 227         err = guc_action_register_ct_buffer(guc,
 228                                             base + PAGE_SIZE/4 * CTB_SEND,
 229                                             INTEL_GUC_CT_BUFFER_TYPE_SEND);
 230         if (unlikely(err))
 231                 goto err_deregister;
 232
 233         return 0;
 234
 235 err_deregister:
 236         guc_action_deregister_ct_buffer(guc,
 237                                         ctch->owner,
 238                                         INTEL_GUC_CT_BUFFER_TYPE_RECV);
 239 err_fini:
 240         ctch_fini(guc, ctch);
 241 err_out:
 242         DRM_ERROR("CT: can't open channel %d; err=%d\n", ctch->owner, err);
 243         return err;
 244 }
 245
 246 static void ctch_close(struct intel_guc *guc,
 247                        struct intel_guc_ct_channel *ctch)
 248 {
 249         GEM_BUG_ON(!ctch_is_open(ctch));
 250
 251         guc_action_deregister_ct_buffer(guc,
 252                                         ctch->owner,
 253                                         INTEL_GUC_CT_BUFFER_TYPE_SEND);
 254         guc_action_deregister_ct_buffer(guc,
 255                                         ctch->owner,
 256                                         INTEL_GUC_CT_BUFFER_TYPE_RECV);
 257         ctch_fini(guc, ctch);
 258 }
 259
 260 static u32 ctch_get_next_fence(struct intel_guc_ct_channel *ctch)
 261 {
 262         /* For now it's trivial */
 263         return ++ctch->next_fence;
 264 }
 265
 266 static int ctb_write(struct intel_guc_ct_buffer *ctb,
 267                      const u32 *action,
 268                      u32 len /* in dwords */,
 269                      u32 fence)
 270 {
 271         struct guc_ct_buffer_desc *desc = ctb->desc;
 272         u32 head = desc->head / 4;      /* in dwords */
 273         u32 tail = desc->tail / 4;      /* in dwords */
 274         u32 size = desc->size / 4;      /* in dwords */
 275         u32 used;                       /* in dwords */
 276         u32 header;
 277         u32 *cmds = ctb->cmds;
 278         unsigned int i;
 279
 280         GEM_BUG_ON(desc->size % 4);
 281         GEM_BUG_ON(desc->head % 4);
 282         GEM_BUG_ON(desc->tail % 4);
 283         GEM_BUG_ON(tail >= size);
 284
 285         /*
 286          * tail == head condition indicates empty. GuC FW does not support
 287          * using up the entire buffer to get tail == head meaning full.
 288          */
 289         if (tail < head)
 290                 used = (size - head) + tail;
 291         else
 292                 used = tail - head;
 293
 294         /* make sure there is a space including extra dw for the fence */
 295         if (unlikely(used + len + 1 >= size))
 296                 return -ENOSPC;
 297
 298         /* Write the message. The format is the following:
 299          * DW0: header (including action code)
 300          * DW1: fence
 301          * DW2+: action data
 302          */
 303         header = (len << GUC_CT_MSG_LEN_SHIFT) |
 304                  (GUC_CT_MSG_WRITE_FENCE_TO_DESC) |
 305                  (action[0] << GUC_CT_MSG_ACTION_SHIFT);
 306
 307         cmds[tail] = header;
 308         tail = (tail + 1) % size;
 309
 310         cmds[tail] = fence;
 311         tail = (tail + 1) % size;
 312
 313         for (i = 1; i < len; i++) {
 314                 cmds[tail] = action[i];
 315                 tail = (tail + 1) % size;
 316         }
 317
 318         /* now update desc tail (back in bytes) */
 319         desc->tail = tail * 4;
 320         GEM_BUG_ON(desc->tail > desc->size);
 321
 322         return 0;
 323 }
 324
 325 /* Wait for the response from the GuC.
 326  * @fence:      response fence
 327  * @status:     placeholder for status
 328  * return:      0 response received (status is valid)
 329  *              -ETIMEDOUT no response within hardcoded timeout
 330  *              -EPROTO no response, ct buffer was in error
 331  */
 332 static int wait_for_response(struct guc_ct_buffer_desc *desc,
 333                              u32 fence,
 334                              u32 *status)
 335 {
 336         int err;
 337
 338         /*
 339          * Fast commands should complete in less than 10us, so sample quickly
 340          * up to that length of time, then switch to a slower sleep-wait loop.
 341          * No GuC command should ever take longer than 10ms.
 342          */
 343 #define done (READ_ONCE(desc->fence) == fence)
 344         err = wait_for_us(done, 10);
 345         if (err)
 346                 err = wait_for(done, 10);
 347 #undef done
 348
 349         if (unlikely(err)) {
 350                 DRM_ERROR("CT: fence %u failed; reported fence=%u\n",
 351                           fence, desc->fence);
 352
 353                 if (WARN_ON(desc->is_in_error)) {
 354                         /* Something went wrong with the messaging, try to reset
 355                          * the buffer and hope for the best
 356                          */
 357                         guc_ct_buffer_desc_reset(desc);
 358                         err = -EPROTO;
 359                 }
 360         }
 361
 362         *status = desc->status;
 363         return err;
 364 }
 365
 366 static int ctch_send(struct intel_guc *guc,
 367                      struct intel_guc_ct_channel *ctch,
 368                      const u32 *action,
 369                      u32 len,
 370                      u32 *status)
 371 {
 372         struct intel_guc_ct_buffer *ctb = &ctch->ctbs[CTB_SEND];
 373         struct guc_ct_buffer_desc *desc = ctb->desc;
 374         u32 fence;
 375         int err;
 376
 377         GEM_BUG_ON(!ctch_is_open(ctch));
 378         GEM_BUG_ON(!len);
 379         GEM_BUG_ON(len & ~GUC_CT_MSG_LEN_MASK);
 380
 381         fence = ctch_get_next_fence(ctch);
 382         err = ctb_write(ctb, action, len, fence);
 383         if (unlikely(err))
 384                 return err;
 385
 386         intel_guc_notify(guc);
 387
 388         err = wait_for_response(desc, fence, status);
 389         if (unlikely(err))
 390                 return err;
 391         if (*status != INTEL_GUC_STATUS_SUCCESS)
 392                 return -EIO;
 393         return 0;
 394 }
 395
 396 /*
 397  * Command Transport (CT) buffer based GuC send function.
 398  */
 399 static int intel_guc_send_ct(struct intel_guc *guc, const u32 *action, u32 len)
 400 {
 401         struct intel_guc_ct_channel *ctch = &guc->ct.host_channel;
 402         u32 status = ~0; /* undefined */
 403         int err;
 404
 405         mutex_lock(&guc->send_mutex);
 406
 407         err = ctch_send(guc, ctch, action, len, &status);
 408         if (unlikely(err)) {
 409                 DRM_ERROR("CT: send action %#X failed; err=%d status=%#X\n",
 410                           action[0], err, status);
 411         }
 412
 413         mutex_unlock(&guc->send_mutex);
 414         return err;
 415 }
 416
 417 /**
 418  * Enable buffer based command transport
 419  * Shall only be called for platforms with HAS_GUC_CT.
 420  * @guc:        the guc
 421  * return:      0 on success
 422  *              non-zero on failure
 423  */
 424 int intel_guc_enable_ct(struct intel_guc *guc)
 425 {
 426         struct drm_i915_private *dev_priv = guc_to_i915(guc);
 427         struct intel_guc_ct_channel *ctch = &guc->ct.host_channel;
 428         int err;
 429
 430         GEM_BUG_ON(!HAS_GUC_CT(dev_priv));
 431
 432         err = ctch_open(guc, ctch);
 433         if (unlikely(err))
 434                 return err;
 435
 436         /* Switch into cmd transport buffer based send() */
 437         guc->send = intel_guc_send_ct;
 438         DRM_INFO("CT: %s\n", enableddisabled(true));
 439         return 0;
 440 }
 441
 442 /**
 443  * Disable buffer based command transport.
 444  * Shall only be called for platforms with HAS_GUC_CT.
 445  * @guc: the guc
 446  */
 447 void intel_guc_disable_ct(struct intel_guc *guc)
 448 {
 449         struct drm_i915_private *dev_priv = guc_to_i915(guc);
 450         struct intel_guc_ct_channel *ctch = &guc->ct.host_channel;
 451
 452         GEM_BUG_ON(!HAS_GUC_CT(dev_priv));
 453
 454         if (!ctch_is_open(ctch))
 455                 return;
 456
 457         ctch_close(guc, ctch);
 458
 459         /* Disable send */
 460         guc->send = intel_guc_send_nop;
 461         DRM_INFO("CT: %s\n", enableddisabled(false));
 462 }