drivers/infiniband/hw/efa/efa_com.c

   1 // SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause
   2 /*
   3  * Copyright 2018-2019 Amazon.com, Inc. or its affiliates. All rights reserved.
   4  */
   5
   6 #include "efa_com.h"
   7 #include "efa_regs_defs.h"
   8
   9 #define ADMIN_CMD_TIMEOUT_US 30000000 /* usecs */
  10
  11 #define EFA_REG_READ_TIMEOUT_US 50000 /* usecs */
  12 #define EFA_MMIO_READ_INVALID 0xffffffff
  13
  14 #define EFA_POLL_INTERVAL_MS 100 /* msecs */
  15
  16 #define EFA_ASYNC_QUEUE_DEPTH 16
  17 #define EFA_ADMIN_QUEUE_DEPTH 32
  18
  19 #define MIN_EFA_VER\
  20         ((EFA_ADMIN_API_VERSION_MAJOR << EFA_REGS_VERSION_MAJOR_VERSION_SHIFT) | \
  21          (EFA_ADMIN_API_VERSION_MINOR & EFA_REGS_VERSION_MINOR_VERSION_MASK))
  22
  23 #define EFA_CTRL_MAJOR          0
  24 #define EFA_CTRL_MINOR          0
  25 #define EFA_CTRL_SUB_MINOR      1
  26
  27 #define MIN_EFA_CTRL_VER \
  28         (((EFA_CTRL_MAJOR) << \
  29         (EFA_REGS_CONTROLLER_VERSION_MAJOR_VERSION_SHIFT)) | \
  30         ((EFA_CTRL_MINOR) << \
  31         (EFA_REGS_CONTROLLER_VERSION_MINOR_VERSION_SHIFT)) | \
  32         (EFA_CTRL_SUB_MINOR))
  33
  34 #define EFA_DMA_ADDR_TO_UINT32_LOW(x)   ((u32)((u64)(x)))
  35 #define EFA_DMA_ADDR_TO_UINT32_HIGH(x)  ((u32)(((u64)(x)) >> 32))
  36
  37 #define EFA_REGS_ADMIN_INTR_MASK 1
  38
  39 enum efa_cmd_status {
  40         EFA_CMD_SUBMITTED,
  41         EFA_CMD_COMPLETED,
  42 };
  43
  44 struct efa_comp_ctx {
  45         struct completion wait_event;
  46         struct efa_admin_acq_entry *user_cqe;
  47         u32 comp_size;
  48         enum efa_cmd_status status;
  49         /* status from the device */
  50         u8 comp_status;
  51         u8 cmd_opcode;
  52         u8 occupied;
  53 };
  54
  55 static const char *efa_com_cmd_str(u8 cmd)
  56 {
  57 #define EFA_CMD_STR_CASE(_cmd) case EFA_ADMIN_##_cmd: return #_cmd
  58
  59         switch (cmd) {
  60         EFA_CMD_STR_CASE(CREATE_QP);
  61         EFA_CMD_STR_CASE(MODIFY_QP);
  62         EFA_CMD_STR_CASE(QUERY_QP);
  63         EFA_CMD_STR_CASE(DESTROY_QP);
  64         EFA_CMD_STR_CASE(CREATE_AH);
  65         EFA_CMD_STR_CASE(DESTROY_AH);
  66         EFA_CMD_STR_CASE(REG_MR);
  67         EFA_CMD_STR_CASE(DEREG_MR);
  68         EFA_CMD_STR_CASE(CREATE_CQ);
  69         EFA_CMD_STR_CASE(DESTROY_CQ);
  70         EFA_CMD_STR_CASE(GET_FEATURE);
  71         EFA_CMD_STR_CASE(SET_FEATURE);
  72         EFA_CMD_STR_CASE(GET_STATS);
  73         EFA_CMD_STR_CASE(ALLOC_PD);
  74         EFA_CMD_STR_CASE(DEALLOC_PD);
  75         EFA_CMD_STR_CASE(ALLOC_UAR);
  76         EFA_CMD_STR_CASE(DEALLOC_UAR);
  77         default: return "unknown command opcode";
  78         }
  79 #undef EFA_CMD_STR_CASE
  80 }
  81
  82 static u32 efa_com_reg_read32(struct efa_com_dev *edev, u16 offset)
  83 {
  84         struct efa_com_mmio_read *mmio_read = &edev->mmio_read;
  85         struct efa_admin_mmio_req_read_less_resp *read_resp;
  86         unsigned long exp_time;
  87         u32 mmio_read_reg;
  88         u32 err;
  89
  90         read_resp = mmio_read->read_resp;
  91
  92         spin_lock(&mmio_read->lock);
  93         mmio_read->seq_num++;
  94
  95         /* trash DMA req_id to identify when hardware is done */
  96         read_resp->req_id = mmio_read->seq_num + 0x9aL;
  97         mmio_read_reg = (offset << EFA_REGS_MMIO_REG_READ_REG_OFF_SHIFT) &
  98                         EFA_REGS_MMIO_REG_READ_REG_OFF_MASK;
  99         mmio_read_reg |= mmio_read->seq_num &
 100                          EFA_REGS_MMIO_REG_READ_REQ_ID_MASK;
 101
 102         writel(mmio_read_reg, edev->reg_bar + EFA_REGS_MMIO_REG_READ_OFF);
 103
 104         exp_time = jiffies + usecs_to_jiffies(mmio_read->mmio_read_timeout);
 105         do {
 106                 if (READ_ONCE(read_resp->req_id) == mmio_read->seq_num)
 107                         break;
 108                 udelay(1);
 109         } while (time_is_after_jiffies(exp_time));
 110
 111         if (read_resp->req_id != mmio_read->seq_num) {
 112                 ibdev_err_ratelimited(
 113                         edev->efa_dev,
 114                         "Reading register timed out. expected: req id[%u] offset[%#x] actual: req id[%u] offset[%#x]\n",
 115                         mmio_read->seq_num, offset, read_resp->req_id,
 116                         read_resp->reg_off);
 117                 err = EFA_MMIO_READ_INVALID;
 118                 goto out;
 119         }
 120
 121         if (read_resp->reg_off != offset) {
 122                 ibdev_err_ratelimited(
 123                         edev->efa_dev,
 124                         "Reading register failed: wrong offset provided\n");
 125                 err = EFA_MMIO_READ_INVALID;
 126                 goto out;
 127         }
 128
 129         err = read_resp->reg_val;
 130 out:
 131         spin_unlock(&mmio_read->lock);
 132         return err;
 133 }
 134
 135 static int efa_com_admin_init_sq(struct efa_com_dev *edev)
 136 {
 137         struct efa_com_admin_queue *aq = &edev->aq;
 138         struct efa_com_admin_sq *sq = &aq->sq;
 139         u16 size = aq->depth * sizeof(*sq->entries);
 140         u32 addr_high;
 141         u32 addr_low;
 142         u32 aq_caps;
 143
 144         sq->entries =
 145                 dma_alloc_coherent(aq->dmadev, size, &sq->dma_addr, GFP_KERNEL);
 146         if (!sq->entries)
 147                 return -ENOMEM;
 148
 149         spin_lock_init(&sq->lock);
 150
 151         sq->cc = 0;
 152         sq->pc = 0;
 153         sq->phase = 1;
 154
 155         sq->db_addr = (u32 __iomem *)(edev->reg_bar + EFA_REGS_AQ_PROD_DB_OFF);
 156
 157         addr_high = EFA_DMA_ADDR_TO_UINT32_HIGH(sq->dma_addr);
 158         addr_low = EFA_DMA_ADDR_TO_UINT32_LOW(sq->dma_addr);
 159
 160         writel(addr_low, edev->reg_bar + EFA_REGS_AQ_BASE_LO_OFF);
 161         writel(addr_high, edev->reg_bar + EFA_REGS_AQ_BASE_HI_OFF);
 162
 163         aq_caps = aq->depth & EFA_REGS_AQ_CAPS_AQ_DEPTH_MASK;
 164         aq_caps |= (sizeof(struct efa_admin_aq_entry) <<
 165                         EFA_REGS_AQ_CAPS_AQ_ENTRY_SIZE_SHIFT) &
 166                         EFA_REGS_AQ_CAPS_AQ_ENTRY_SIZE_MASK;
 167
 168         writel(aq_caps, edev->reg_bar + EFA_REGS_AQ_CAPS_OFF);
 169
 170         return 0;
 171 }
 172
 173 static int efa_com_admin_init_cq(struct efa_com_dev *edev)
 174 {
 175         struct efa_com_admin_queue *aq = &edev->aq;
 176         struct efa_com_admin_cq *cq = &aq->cq;
 177         u16 size = aq->depth * sizeof(*cq->entries);
 178         u32 addr_high;
 179         u32 addr_low;
 180         u32 acq_caps;
 181
 182         cq->entries =
 183                 dma_alloc_coherent(aq->dmadev, size, &cq->dma_addr, GFP_KERNEL);
 184         if (!cq->entries)
 185                 return -ENOMEM;
 186
 187         spin_lock_init(&cq->lock);
 188
 189         cq->cc = 0;
 190         cq->phase = 1;
 191
 192         addr_high = EFA_DMA_ADDR_TO_UINT32_HIGH(cq->dma_addr);
 193         addr_low = EFA_DMA_ADDR_TO_UINT32_LOW(cq->dma_addr);
 194
 195         writel(addr_low, edev->reg_bar + EFA_REGS_ACQ_BASE_LO_OFF);
 196         writel(addr_high, edev->reg_bar + EFA_REGS_ACQ_BASE_HI_OFF);
 197
 198         acq_caps = aq->depth & EFA_REGS_ACQ_CAPS_ACQ_DEPTH_MASK;
 199         acq_caps |= (sizeof(struct efa_admin_acq_entry) <<
 200                         EFA_REGS_ACQ_CAPS_ACQ_ENTRY_SIZE_SHIFT) &
 201                         EFA_REGS_ACQ_CAPS_ACQ_ENTRY_SIZE_MASK;
 202         acq_caps |= (aq->msix_vector_idx <<
 203                         EFA_REGS_ACQ_CAPS_ACQ_MSIX_VECTOR_SHIFT) &
 204                         EFA_REGS_ACQ_CAPS_ACQ_MSIX_VECTOR_MASK;
 205
 206         writel(acq_caps, edev->reg_bar + EFA_REGS_ACQ_CAPS_OFF);
 207
 208         return 0;
 209 }
 210
 211 static int efa_com_admin_init_aenq(struct efa_com_dev *edev,
 212                                    struct efa_aenq_handlers *aenq_handlers)
 213 {
 214         struct efa_com_aenq *aenq = &edev->aenq;
 215         u32 addr_low, addr_high, aenq_caps;
 216         u16 size;
 217
 218         if (!aenq_handlers) {
 219                 ibdev_err(edev->efa_dev, "aenq handlers pointer is NULL\n");
 220                 return -EINVAL;
 221         }
 222
 223         size = EFA_ASYNC_QUEUE_DEPTH * sizeof(*aenq->entries);
 224         aenq->entries = dma_alloc_coherent(edev->dmadev, size, &aenq->dma_addr,
 225                                            GFP_KERNEL);
 226         if (!aenq->entries)
 227                 return -ENOMEM;
 228
 229         aenq->aenq_handlers = aenq_handlers;
 230         aenq->depth = EFA_ASYNC_QUEUE_DEPTH;
 231         aenq->cc = 0;
 232         aenq->phase = 1;
 233
 234         addr_low = EFA_DMA_ADDR_TO_UINT32_LOW(aenq->dma_addr);
 235         addr_high = EFA_DMA_ADDR_TO_UINT32_HIGH(aenq->dma_addr);
 236
 237         writel(addr_low, edev->reg_bar + EFA_REGS_AENQ_BASE_LO_OFF);
 238         writel(addr_high, edev->reg_bar + EFA_REGS_AENQ_BASE_HI_OFF);
 239
 240         aenq_caps = aenq->depth & EFA_REGS_AENQ_CAPS_AENQ_DEPTH_MASK;
 241         aenq_caps |= (sizeof(struct efa_admin_aenq_entry) <<
 242                 EFA_REGS_AENQ_CAPS_AENQ_ENTRY_SIZE_SHIFT) &
 243                 EFA_REGS_AENQ_CAPS_AENQ_ENTRY_SIZE_MASK;
 244         aenq_caps |= (aenq->msix_vector_idx
 245                       << EFA_REGS_AENQ_CAPS_AENQ_MSIX_VECTOR_SHIFT) &
 246                      EFA_REGS_AENQ_CAPS_AENQ_MSIX_VECTOR_MASK;
 247         writel(aenq_caps, edev->reg_bar + EFA_REGS_AENQ_CAPS_OFF);
 248
 249         /*
 250          * Init cons_db to mark that all entries in the queue
 251          * are initially available
 252          */
 253         writel(edev->aenq.cc, edev->reg_bar + EFA_REGS_AENQ_CONS_DB_OFF);
 254
 255         return 0;
 256 }
 257
 258 /* ID to be used with efa_com_get_comp_ctx */
 259 static u16 efa_com_alloc_ctx_id(struct efa_com_admin_queue *aq)
 260 {
 261         u16 ctx_id;
 262
 263         spin_lock(&aq->comp_ctx_lock);
 264         ctx_id = aq->comp_ctx_pool[aq->comp_ctx_pool_next];
 265         aq->comp_ctx_pool_next++;
 266         spin_unlock(&aq->comp_ctx_lock);
 267
 268         return ctx_id;
 269 }
 270
 271 static void efa_com_dealloc_ctx_id(struct efa_com_admin_queue *aq,
 272                                    u16 ctx_id)
 273 {
 274         spin_lock(&aq->comp_ctx_lock);
 275         aq->comp_ctx_pool_next--;
 276         aq->comp_ctx_pool[aq->comp_ctx_pool_next] = ctx_id;
 277         spin_unlock(&aq->comp_ctx_lock);
 278 }
 279
 280 static inline void efa_com_put_comp_ctx(struct efa_com_admin_queue *aq,
 281                                         struct efa_comp_ctx *comp_ctx)
 282 {
 283         u16 cmd_id = comp_ctx->user_cqe->acq_common_descriptor.command &
 284                      EFA_ADMIN_ACQ_COMMON_DESC_COMMAND_ID_MASK;
 285         u16 ctx_id = cmd_id & (aq->depth - 1);
 286
 287         ibdev_dbg(aq->efa_dev, "Put completion command_id %#x\n", cmd_id);
 288         comp_ctx->occupied = 0;
 289         efa_com_dealloc_ctx_id(aq, ctx_id);
 290 }
 291
 292 static struct efa_comp_ctx *efa_com_get_comp_ctx(struct efa_com_admin_queue *aq,
 293                                                  u16 cmd_id, bool capture)
 294 {
 295         u16 ctx_id = cmd_id & (aq->depth - 1);
 296
 297         if (aq->comp_ctx[ctx_id].occupied && capture) {
 298                 ibdev_err_ratelimited(
 299                         aq->efa_dev,
 300                         "Completion context for command_id %#x is occupied\n",
 301                         cmd_id);
 302                 return NULL;
 303         }
 304
 305         if (capture) {
 306                 aq->comp_ctx[ctx_id].occupied = 1;
 307                 ibdev_dbg(aq->efa_dev,
 308                           "Take completion ctxt for command_id %#x\n", cmd_id);
 309         }
 310
 311         return &aq->comp_ctx[ctx_id];
 312 }
 313
 314 static struct efa_comp_ctx *__efa_com_submit_admin_cmd(struct efa_com_admin_queue *aq,
 315                                                        struct efa_admin_aq_entry *cmd,
 316                                                        size_t cmd_size_in_bytes,
 317                                                        struct efa_admin_acq_entry *comp,
 318                                                        size_t comp_size_in_bytes)
 319 {
 320         struct efa_admin_aq_entry *aqe;
 321         struct efa_comp_ctx *comp_ctx;
 322         u16 queue_size_mask;
 323         u16 cmd_id;
 324         u16 ctx_id;
 325         u16 pi;
 326
 327         queue_size_mask = aq->depth - 1;
 328         pi = aq->sq.pc & queue_size_mask;
 329
 330         ctx_id = efa_com_alloc_ctx_id(aq);
 331
 332         /* cmd_id LSBs are the ctx_id and MSBs are entropy bits from pc */
 333         cmd_id = ctx_id & queue_size_mask;
 334         cmd_id |= aq->sq.pc & ~queue_size_mask;
 335         cmd_id &= EFA_ADMIN_AQ_COMMON_DESC_COMMAND_ID_MASK;
 336
 337         cmd->aq_common_descriptor.command_id = cmd_id;
 338         cmd->aq_common_descriptor.flags |= aq->sq.phase &
 339                 EFA_ADMIN_AQ_COMMON_DESC_PHASE_MASK;
 340
 341         comp_ctx = efa_com_get_comp_ctx(aq, cmd_id, true);
 342         if (!comp_ctx) {
 343                 efa_com_dealloc_ctx_id(aq, ctx_id);
 344                 return ERR_PTR(-EINVAL);
 345         }
 346
 347         comp_ctx->status = EFA_CMD_SUBMITTED;
 348         comp_ctx->comp_size = comp_size_in_bytes;
 349         comp_ctx->user_cqe = comp;
 350         comp_ctx->cmd_opcode = cmd->aq_common_descriptor.opcode;
 351
 352         reinit_completion(&comp_ctx->wait_event);
 353
 354         aqe = &aq->sq.entries[pi];
 355         memset(aqe, 0, sizeof(*aqe));
 356         memcpy(aqe, cmd, cmd_size_in_bytes);
 357
 358         aq->sq.pc++;
 359         atomic64_inc(&aq->stats.submitted_cmd);
 360
 361         if ((aq->sq.pc & queue_size_mask) == 0)
 362                 aq->sq.phase = !aq->sq.phase;
 363
 364         /* barrier not needed in case of writel */
 365         writel(aq->sq.pc, aq->sq.db_addr);
 366
 367         return comp_ctx;
 368 }
 369
 370 static inline int efa_com_init_comp_ctxt(struct efa_com_admin_queue *aq)
 371 {
 372         size_t pool_size = aq->depth * sizeof(*aq->comp_ctx_pool);
 373         size_t size = aq->depth * sizeof(struct efa_comp_ctx);
 374         struct efa_comp_ctx *comp_ctx;
 375         u16 i;
 376
 377         aq->comp_ctx = devm_kzalloc(aq->dmadev, size, GFP_KERNEL);
 378         aq->comp_ctx_pool = devm_kzalloc(aq->dmadev, pool_size, GFP_KERNEL);
 379         if (!aq->comp_ctx || !aq->comp_ctx_pool) {
 380                 devm_kfree(aq->dmadev, aq->comp_ctx_pool);
 381                 devm_kfree(aq->dmadev, aq->comp_ctx);
 382                 return -ENOMEM;
 383         }
 384
 385         for (i = 0; i < aq->depth; i++) {
 386                 comp_ctx = efa_com_get_comp_ctx(aq, i, false);
 387                 if (comp_ctx)
 388                         init_completion(&comp_ctx->wait_event);
 389
 390                 aq->comp_ctx_pool[i] = i;
 391         }
 392
 393         spin_lock_init(&aq->comp_ctx_lock);
 394
 395         aq->comp_ctx_pool_next = 0;
 396
 397         return 0;
 398 }
 399
 400 static struct efa_comp_ctx *efa_com_submit_admin_cmd(struct efa_com_admin_queue *aq,
 401                                                      struct efa_admin_aq_entry *cmd,
 402                                                      size_t cmd_size_in_bytes,
 403                                                      struct efa_admin_acq_entry *comp,
 404                                                      size_t comp_size_in_bytes)
 405 {
 406         struct efa_comp_ctx *comp_ctx;
 407
 408         spin_lock(&aq->sq.lock);
 409         if (!test_bit(EFA_AQ_STATE_RUNNING_BIT, &aq->state)) {
 410                 ibdev_err_ratelimited(aq->efa_dev, "Admin queue is closed\n");
 411                 spin_unlock(&aq->sq.lock);
 412                 return ERR_PTR(-ENODEV);
 413         }
 414
 415         comp_ctx = __efa_com_submit_admin_cmd(aq, cmd, cmd_size_in_bytes, comp,
 416                                               comp_size_in_bytes);
 417         spin_unlock(&aq->sq.lock);
 418         if (IS_ERR(comp_ctx))
 419                 clear_bit(EFA_AQ_STATE_RUNNING_BIT, &aq->state);
 420
 421         return comp_ctx;
 422 }
 423
 424 static void efa_com_handle_single_admin_completion(struct efa_com_admin_queue *aq,
 425                                                    struct efa_admin_acq_entry *cqe)
 426 {
 427         struct efa_comp_ctx *comp_ctx;
 428         u16 cmd_id;
 429
 430         cmd_id = cqe->acq_common_descriptor.command &
 431                  EFA_ADMIN_ACQ_COMMON_DESC_COMMAND_ID_MASK;
 432
 433         comp_ctx = efa_com_get_comp_ctx(aq, cmd_id, false);
 434         if (!comp_ctx) {
 435                 ibdev_err(aq->efa_dev,
 436                           "comp_ctx is NULL. Changing the admin queue running state\n");
 437                 clear_bit(EFA_AQ_STATE_RUNNING_BIT, &aq->state);
 438                 return;
 439         }
 440
 441         comp_ctx->status = EFA_CMD_COMPLETED;
 442         comp_ctx->comp_status = cqe->acq_common_descriptor.status;
 443         if (comp_ctx->user_cqe)
 444                 memcpy(comp_ctx->user_cqe, cqe, comp_ctx->comp_size);
 445
 446         if (!test_bit(EFA_AQ_STATE_POLLING_BIT, &aq->state))
 447                 complete(&comp_ctx->wait_event);
 448 }
 449
 450 static void efa_com_handle_admin_completion(struct efa_com_admin_queue *aq)
 451 {
 452         struct efa_admin_acq_entry *cqe;
 453         u16 queue_size_mask;
 454         u16 comp_num = 0;
 455         u8 phase;
 456         u16 ci;
 457
 458         queue_size_mask = aq->depth - 1;
 459
 460         ci = aq->cq.cc & queue_size_mask;
 461         phase = aq->cq.phase;
 462
 463         cqe = &aq->cq.entries[ci];
 464
 465         /* Go over all the completions */
 466         while ((READ_ONCE(cqe->acq_common_descriptor.flags) &
 467                 EFA_ADMIN_ACQ_COMMON_DESC_PHASE_MASK) == phase) {
 468                 /*
 469                  * Do not read the rest of the completion entry before the
 470                  * phase bit was validated
 471                  */
 472                 dma_rmb();
 473                 efa_com_handle_single_admin_completion(aq, cqe);
 474
 475                 ci++;
 476                 comp_num++;
 477                 if (ci == aq->depth) {
 478                         ci = 0;
 479                         phase = !phase;
 480                 }
 481
 482                 cqe = &aq->cq.entries[ci];
 483         }
 484
 485         aq->cq.cc += comp_num;
 486         aq->cq.phase = phase;
 487         aq->sq.cc += comp_num;
 488         atomic64_add(comp_num, &aq->stats.completed_cmd);
 489 }
 490
 491 static int efa_com_comp_status_to_errno(u8 comp_status)
 492 {
 493         switch (comp_status) {
 494         case EFA_ADMIN_SUCCESS:
 495                 return 0;
 496         case EFA_ADMIN_RESOURCE_ALLOCATION_FAILURE:
 497                 return -ENOMEM;
 498         case EFA_ADMIN_UNSUPPORTED_OPCODE:
 499                 return -EOPNOTSUPP;
 500         case EFA_ADMIN_BAD_OPCODE:
 501         case EFA_ADMIN_MALFORMED_REQUEST:
 502         case EFA_ADMIN_ILLEGAL_PARAMETER:
 503         case EFA_ADMIN_UNKNOWN_ERROR:
 504                 return -EINVAL;
 505         default:
 506                 return -EINVAL;
 507         }
 508 }
 509
 510 static int efa_com_wait_and_process_admin_cq_polling(struct efa_comp_ctx *comp_ctx,
 511                                                      struct efa_com_admin_queue *aq)
 512 {
 513         unsigned long timeout;
 514         unsigned long flags;
 515         int err;
 516
 517         timeout = jiffies + usecs_to_jiffies(aq->completion_timeout);
 518
 519         while (1) {
 520                 spin_lock_irqsave(&aq->cq.lock, flags);
 521                 efa_com_handle_admin_completion(aq);
 522                 spin_unlock_irqrestore(&aq->cq.lock, flags);
 523
 524                 if (comp_ctx->status != EFA_CMD_SUBMITTED)
 525                         break;
 526
 527                 if (time_is_before_jiffies(timeout)) {
 528                         ibdev_err_ratelimited(
 529                                 aq->efa_dev,
 530                                 "Wait for completion (polling) timeout\n");
 531                         /* EFA didn't have any completion */
 532                         atomic64_inc(&aq->stats.no_completion);
 533
 534                         clear_bit(EFA_AQ_STATE_RUNNING_BIT, &aq->state);
 535                         err = -ETIME;
 536                         goto out;
 537                 }
 538
 539                 msleep(aq->poll_interval);
 540         }
 541
 542         err = efa_com_comp_status_to_errno(comp_ctx->comp_status);
 543 out:
 544         efa_com_put_comp_ctx(aq, comp_ctx);
 545         return err;
 546 }
 547
 548 static int efa_com_wait_and_process_admin_cq_interrupts(struct efa_comp_ctx *comp_ctx,
 549                                                         struct efa_com_admin_queue *aq)
 550 {
 551         unsigned long flags;
 552         int err;
 553
 554         wait_for_completion_timeout(&comp_ctx->wait_event,
 555                                     usecs_to_jiffies(aq->completion_timeout));
 556
 557         /*
 558          * In case the command wasn't completed find out the root cause.
 559          * There might be 2 kinds of errors
 560          * 1) No completion (timeout reached)
 561          * 2) There is completion but the device didn't get any msi-x interrupt.
 562          */
 563         if (comp_ctx->status == EFA_CMD_SUBMITTED) {
 564                 spin_lock_irqsave(&aq->cq.lock, flags);
 565                 efa_com_handle_admin_completion(aq);
 566                 spin_unlock_irqrestore(&aq->cq.lock, flags);
 567
 568                 atomic64_inc(&aq->stats.no_completion);
 569
 570                 if (comp_ctx->status == EFA_CMD_COMPLETED)
 571                         ibdev_err_ratelimited(
 572                                 aq->efa_dev,
 573                                 "The device sent a completion but the driver didn't receive any MSI-X interrupt for admin cmd %s(%d) status %d (ctx: 0x%p, sq producer: %d, sq consumer: %d, cq consumer: %d)\n",
 574                                 efa_com_cmd_str(comp_ctx->cmd_opcode),
 575                                 comp_ctx->cmd_opcode, comp_ctx->status,
 576                                 comp_ctx, aq->sq.pc, aq->sq.cc, aq->cq.cc);
 577                 else
 578                         ibdev_err_ratelimited(
 579                                 aq->efa_dev,
 580                                 "The device didn't send any completion for admin cmd %s(%d) status %d (ctx 0x%p, sq producer: %d, sq consumer: %d, cq consumer: %d)\n",
 581                                 efa_com_cmd_str(comp_ctx->cmd_opcode),
 582                                 comp_ctx->cmd_opcode, comp_ctx->status,
 583                                 comp_ctx, aq->sq.pc, aq->sq.cc, aq->cq.cc);
 584
 585                 clear_bit(EFA_AQ_STATE_RUNNING_BIT, &aq->state);
 586                 err = -ETIME;
 587                 goto out;
 588         }
 589
 590         err = efa_com_comp_status_to_errno(comp_ctx->comp_status);
 591 out:
 592         efa_com_put_comp_ctx(aq, comp_ctx);
 593         return err;
 594 }
 595
 596 /*
 597  * There are two types to wait for completion.
 598  * Polling mode - wait until the completion is available.
 599  * Async mode - wait on wait queue until the completion is ready
 600  * (or the timeout expired).
 601  * It is expected that the IRQ called efa_com_handle_admin_completion
 602  * to mark the completions.
 603  */
 604 static int efa_com_wait_and_process_admin_cq(struct efa_comp_ctx *comp_ctx,
 605                                              struct efa_com_admin_queue *aq)
 606 {
 607         if (test_bit(EFA_AQ_STATE_POLLING_BIT, &aq->state))
 608                 return efa_com_wait_and_process_admin_cq_polling(comp_ctx, aq);
 609
 610         return efa_com_wait_and_process_admin_cq_interrupts(comp_ctx, aq);
 611 }
 612
 613 /**
 614  * efa_com_cmd_exec - Execute admin command
 615  * @aq: admin queue.
 616  * @cmd: the admin command to execute.
 617  * @cmd_size: the command size.
 618  * @comp: command completion return entry.
 619  * @comp_size: command completion size.
 620  * Submit an admin command and then wait until the device will return a
 621  * completion.
 622  * The completion will be copied into comp.
 623  *
 624  * @return - 0 on success, negative value on failure.
 625  */
 626 int efa_com_cmd_exec(struct efa_com_admin_queue *aq,
 627                      struct efa_admin_aq_entry *cmd,
 628                      size_t cmd_size,
 629                      struct efa_admin_acq_entry *comp,
 630                      size_t comp_size)
 631 {
 632         struct efa_comp_ctx *comp_ctx;
 633         int err;
 634
 635         might_sleep();
 636
 637         /* In case of queue FULL */
 638         down(&aq->avail_cmds);
 639
 640         ibdev_dbg(aq->efa_dev, "%s (opcode %d)\n",
 641                   efa_com_cmd_str(cmd->aq_common_descriptor.opcode),
 642                   cmd->aq_common_descriptor.opcode);
 643         comp_ctx = efa_com_submit_admin_cmd(aq, cmd, cmd_size, comp, comp_size);
 644         if (IS_ERR(comp_ctx)) {
 645                 ibdev_err_ratelimited(
 646                         aq->efa_dev,
 647                         "Failed to submit command %s (opcode %u) err %ld\n",
 648                         efa_com_cmd_str(cmd->aq_common_descriptor.opcode),
 649                         cmd->aq_common_descriptor.opcode, PTR_ERR(comp_ctx));
 650
 651                 up(&aq->avail_cmds);
 652                 return PTR_ERR(comp_ctx);
 653         }
 654
 655         err = efa_com_wait_and_process_admin_cq(comp_ctx, aq);
 656         if (err)
 657                 ibdev_err_ratelimited(
 658                         aq->efa_dev,
 659                         "Failed to process command %s (opcode %u) comp_status %d err %d\n",
 660                         efa_com_cmd_str(cmd->aq_common_descriptor.opcode),
 661                         cmd->aq_common_descriptor.opcode, comp_ctx->comp_status,
 662                         err);
 663
 664         up(&aq->avail_cmds);
 665
 666         return err;
 667 }
 668
 669 /**
 670  * efa_com_admin_destroy - Destroy the admin and the async events queues.
 671  * @edev: EFA communication layer struct
 672  */
 673 void efa_com_admin_destroy(struct efa_com_dev *edev)
 674 {
 675         struct efa_com_admin_queue *aq = &edev->aq;
 676         struct efa_com_aenq *aenq = &edev->aenq;
 677         struct efa_com_admin_cq *cq = &aq->cq;
 678         struct efa_com_admin_sq *sq = &aq->sq;
 679         u16 size;
 680
 681         clear_bit(EFA_AQ_STATE_RUNNING_BIT, &aq->state);
 682
 683         devm_kfree(edev->dmadev, aq->comp_ctx_pool);
 684         devm_kfree(edev->dmadev, aq->comp_ctx);
 685
 686         size = aq->depth * sizeof(*sq->entries);
 687         dma_free_coherent(edev->dmadev, size, sq->entries, sq->dma_addr);
 688
 689         size = aq->depth * sizeof(*cq->entries);
 690         dma_free_coherent(edev->dmadev, size, cq->entries, cq->dma_addr);
 691
 692         size = aenq->depth * sizeof(*aenq->entries);
 693         dma_free_coherent(edev->dmadev, size, aenq->entries, aenq->dma_addr);
 694 }
 695
 696 /**
 697  * efa_com_set_admin_polling_mode - Set the admin completion queue polling mode
 698  * @edev: EFA communication layer struct
 699  * @polling: Enable/Disable polling mode
 700  *
 701  * Set the admin completion mode.
 702  */
 703 void efa_com_set_admin_polling_mode(struct efa_com_dev *edev, bool polling)
 704 {
 705         u32 mask_value = 0;
 706
 707         if (polling)
 708                 mask_value = EFA_REGS_ADMIN_INTR_MASK;
 709
 710         writel(mask_value, edev->reg_bar + EFA_REGS_INTR_MASK_OFF);
 711         if (polling)
 712                 set_bit(EFA_AQ_STATE_POLLING_BIT, &edev->aq.state);
 713         else
 714                 clear_bit(EFA_AQ_STATE_POLLING_BIT, &edev->aq.state);
 715 }
 716
 717 static void efa_com_stats_init(struct efa_com_dev *edev)
 718 {
 719         atomic64_t *s = (atomic64_t *)&edev->aq.stats;
 720         int i;
 721
 722         for (i = 0; i < sizeof(edev->aq.stats) / sizeof(*s); i++, s++)
 723                 atomic64_set(s, 0);
 724 }
 725
 726 /**
 727  * efa_com_admin_init - Init the admin and the async queues
 728  * @edev: EFA communication layer struct
 729  * @aenq_handlers: Those handlers to be called upon event.
 730  *
 731  * Initialize the admin submission and completion queues.
 732  * Initialize the asynchronous events notification queues.
 733  *
 734  * @return - 0 on success, negative value on failure.
 735  */
 736 int efa_com_admin_init(struct efa_com_dev *edev,
 737                        struct efa_aenq_handlers *aenq_handlers)
 738 {
 739         struct efa_com_admin_queue *aq = &edev->aq;
 740         u32 timeout;
 741         u32 dev_sts;
 742         u32 cap;
 743         int err;
 744
 745         dev_sts = efa_com_reg_read32(edev, EFA_REGS_DEV_STS_OFF);
 746         if (!(dev_sts & EFA_REGS_DEV_STS_READY_MASK)) {
 747                 ibdev_err(edev->efa_dev,
 748                           "Device isn't ready, abort com init %#x\n", dev_sts);
 749                 return -ENODEV;
 750         }
 751
 752         aq->depth = EFA_ADMIN_QUEUE_DEPTH;
 753
 754         aq->dmadev = edev->dmadev;
 755         aq->efa_dev = edev->efa_dev;
 756         set_bit(EFA_AQ_STATE_POLLING_BIT, &aq->state);
 757
 758         sema_init(&aq->avail_cmds, aq->depth);
 759
 760         efa_com_stats_init(edev);
 761
 762         err = efa_com_init_comp_ctxt(aq);
 763         if (err)
 764                 return err;
 765
 766         err = efa_com_admin_init_sq(edev);
 767         if (err)
 768                 goto err_destroy_comp_ctxt;
 769
 770         err = efa_com_admin_init_cq(edev);
 771         if (err)
 772                 goto err_destroy_sq;
 773
 774         efa_com_set_admin_polling_mode(edev, false);
 775
 776         err = efa_com_admin_init_aenq(edev, aenq_handlers);
 777         if (err)
 778                 goto err_destroy_cq;
 779
 780         cap = efa_com_reg_read32(edev, EFA_REGS_CAPS_OFF);
 781         timeout = (cap & EFA_REGS_CAPS_ADMIN_CMD_TO_MASK) >>
 782                   EFA_REGS_CAPS_ADMIN_CMD_TO_SHIFT;
 783         if (timeout)
 784                 /* the resolution of timeout reg is 100ms */
 785                 aq->completion_timeout = timeout * 100000;
 786         else
 787                 aq->completion_timeout = ADMIN_CMD_TIMEOUT_US;
 788
 789         aq->poll_interval = EFA_POLL_INTERVAL_MS;
 790
 791         set_bit(EFA_AQ_STATE_RUNNING_BIT, &aq->state);
 792
 793         return 0;
 794
 795 err_destroy_cq:
 796         dma_free_coherent(edev->dmadev, aq->depth * sizeof(*aq->cq.entries),
 797                           aq->cq.entries, aq->cq.dma_addr);
 798 err_destroy_sq:
 799         dma_free_coherent(edev->dmadev, aq->depth * sizeof(*aq->sq.entries),
 800                           aq->sq.entries, aq->sq.dma_addr);
 801 err_destroy_comp_ctxt:
 802         devm_kfree(edev->dmadev, aq->comp_ctx);
 803
 804         return err;
 805 }
 806
 807 /**
 808  * efa_com_admin_q_comp_intr_handler - admin queue interrupt handler
 809  * @edev: EFA communication layer struct
 810  *
 811  * This method goes over the admin completion queue and wakes up
 812  * all the pending threads that wait on the commands wait event.
 813  *
 814  * @note: Should be called after MSI-X interrupt.
 815  */
 816 void efa_com_admin_q_comp_intr_handler(struct efa_com_dev *edev)
 817 {
 818         unsigned long flags;
 819
 820         spin_lock_irqsave(&edev->aq.cq.lock, flags);
 821         efa_com_handle_admin_completion(&edev->aq);
 822         spin_unlock_irqrestore(&edev->aq.cq.lock, flags);
 823 }
 824
 825 /*
 826  * efa_handle_specific_aenq_event:
 827  * return the handler that is relevant to the specific event group
 828  */
 829 static efa_aenq_handler efa_com_get_specific_aenq_cb(struct efa_com_dev *edev,
 830                                                      u16 group)
 831 {
 832         struct efa_aenq_handlers *aenq_handlers = edev->aenq.aenq_handlers;
 833
 834         if (group < EFA_MAX_HANDLERS && aenq_handlers->handlers[group])
 835                 return aenq_handlers->handlers[group];
 836
 837         return aenq_handlers->unimplemented_handler;
 838 }
 839
 840 /**
 841  * efa_com_aenq_intr_handler - AENQ interrupt handler
 842  * @edev: EFA communication layer struct
 843  * @data: Data of interrupt handler.
 844  *
 845  * Go over the async event notification queue and call the proper aenq handler.
 846  */
 847 void efa_com_aenq_intr_handler(struct efa_com_dev *edev, void *data)
 848 {
 849         struct efa_admin_aenq_common_desc *aenq_common;
 850         struct efa_com_aenq *aenq = &edev->aenq;
 851         struct efa_admin_aenq_entry *aenq_e;
 852         efa_aenq_handler handler_cb;
 853         u32 processed = 0;
 854         u8 phase;
 855         u32 ci;
 856
 857         ci = aenq->cc & (aenq->depth - 1);
 858         phase = aenq->phase;
 859         aenq_e = &aenq->entries[ci]; /* Get first entry */
 860         aenq_common = &aenq_e->aenq_common_desc;
 861
 862         /* Go over all the events */
 863         while ((READ_ONCE(aenq_common->flags) &
 864                 EFA_ADMIN_AENQ_COMMON_DESC_PHASE_MASK) == phase) {
 865                 /*
 866                  * Do not read the rest of the completion entry before the
 867                  * phase bit was validated
 868                  */
 869                 dma_rmb();
 870
 871                 /* Handle specific event*/
 872                 handler_cb = efa_com_get_specific_aenq_cb(edev,
 873                                                           aenq_common->group);
 874                 handler_cb(data, aenq_e); /* call the actual event handler*/
 875
 876                 /* Get next event entry */
 877                 ci++;
 878                 processed++;
 879
 880                 if (ci == aenq->depth) {
 881                         ci = 0;
 882                         phase = !phase;
 883                 }
 884                 aenq_e = &aenq->entries[ci];
 885                 aenq_common = &aenq_e->aenq_common_desc;
 886         }
 887
 888         aenq->cc += processed;
 889         aenq->phase = phase;
 890
 891         /* Don't update aenq doorbell if there weren't any processed events */
 892         if (!processed)
 893                 return;
 894
 895         /* barrier not needed in case of writel */
 896         writel(aenq->cc, edev->reg_bar + EFA_REGS_AENQ_CONS_DB_OFF);
 897 }
 898
 899 static void efa_com_mmio_reg_read_resp_addr_init(struct efa_com_dev *edev)
 900 {
 901         struct efa_com_mmio_read *mmio_read = &edev->mmio_read;
 902         u32 addr_high;
 903         u32 addr_low;
 904
 905         /* dma_addr_bits is unknown at this point */
 906         addr_high = (mmio_read->read_resp_dma_addr >> 32) & GENMASK(31, 0);
 907         addr_low = mmio_read->read_resp_dma_addr & GENMASK(31, 0);
 908
 909         writel(addr_high, edev->reg_bar + EFA_REGS_MMIO_RESP_HI_OFF);
 910         writel(addr_low, edev->reg_bar + EFA_REGS_MMIO_RESP_LO_OFF);
 911 }
 912
 913 int efa_com_mmio_reg_read_init(struct efa_com_dev *edev)
 914 {
 915         struct efa_com_mmio_read *mmio_read = &edev->mmio_read;
 916
 917         spin_lock_init(&mmio_read->lock);
 918         mmio_read->read_resp =
 919                 dma_alloc_coherent(edev->dmadev, sizeof(*mmio_read->read_resp),
 920                                    &mmio_read->read_resp_dma_addr, GFP_KERNEL);
 921         if (!mmio_read->read_resp)
 922                 return -ENOMEM;
 923
 924         efa_com_mmio_reg_read_resp_addr_init(edev);
 925
 926         mmio_read->read_resp->req_id = 0;
 927         mmio_read->seq_num = 0;
 928         mmio_read->mmio_read_timeout = EFA_REG_READ_TIMEOUT_US;
 929
 930         return 0;
 931 }
 932
 933 void efa_com_mmio_reg_read_destroy(struct efa_com_dev *edev)
 934 {
 935         struct efa_com_mmio_read *mmio_read = &edev->mmio_read;
 936
 937         dma_free_coherent(edev->dmadev, sizeof(*mmio_read->read_resp),
 938                           mmio_read->read_resp, mmio_read->read_resp_dma_addr);
 939 }
 940
 941 int efa_com_validate_version(struct efa_com_dev *edev)
 942 {
 943         u32 ctrl_ver_masked;
 944         u32 ctrl_ver;
 945         u32 ver;
 946
 947         /*
 948          * Make sure the EFA version and the controller version are at least
 949          * as the driver expects
 950          */
 951         ver = efa_com_reg_read32(edev, EFA_REGS_VERSION_OFF);
 952         ctrl_ver = efa_com_reg_read32(edev,
 953                                       EFA_REGS_CONTROLLER_VERSION_OFF);
 954
 955         ibdev_dbg(edev->efa_dev, "efa device version: %d.%d\n",
 956                   (ver & EFA_REGS_VERSION_MAJOR_VERSION_MASK) >>
 957                           EFA_REGS_VERSION_MAJOR_VERSION_SHIFT,
 958                   ver & EFA_REGS_VERSION_MINOR_VERSION_MASK);
 959
 960         if (ver < MIN_EFA_VER) {
 961                 ibdev_err(edev->efa_dev,
 962                           "EFA version is lower than the minimal version the driver supports\n");
 963                 return -EOPNOTSUPP;
 964         }
 965
 966         ibdev_dbg(edev->efa_dev,
 967                   "efa controller version: %d.%d.%d implementation version %d\n",
 968                   (ctrl_ver & EFA_REGS_CONTROLLER_VERSION_MAJOR_VERSION_MASK) >>
 969                           EFA_REGS_CONTROLLER_VERSION_MAJOR_VERSION_SHIFT,
 970                   (ctrl_ver & EFA_REGS_CONTROLLER_VERSION_MINOR_VERSION_MASK) >>
 971                           EFA_REGS_CONTROLLER_VERSION_MINOR_VERSION_SHIFT,
 972                   (ctrl_ver & EFA_REGS_CONTROLLER_VERSION_SUBMINOR_VERSION_MASK),
 973                   (ctrl_ver & EFA_REGS_CONTROLLER_VERSION_IMPL_ID_MASK) >>
 974                           EFA_REGS_CONTROLLER_VERSION_IMPL_ID_SHIFT);
 975
 976         ctrl_ver_masked =
 977                 (ctrl_ver & EFA_REGS_CONTROLLER_VERSION_MAJOR_VERSION_MASK) |
 978                 (ctrl_ver & EFA_REGS_CONTROLLER_VERSION_MINOR_VERSION_MASK) |
 979                 (ctrl_ver & EFA_REGS_CONTROLLER_VERSION_SUBMINOR_VERSION_MASK);
 980
 981         /* Validate the ctrl version without the implementation ID */
 982         if (ctrl_ver_masked < MIN_EFA_CTRL_VER) {
 983                 ibdev_err(edev->efa_dev,
 984                           "EFA ctrl version is lower than the minimal ctrl version the driver supports\n");
 985                 return -EOPNOTSUPP;
 986         }
 987
 988         return 0;
 989 }
 990
 991 /**
 992  * efa_com_get_dma_width - Retrieve physical dma address width the device
 993  * supports.
 994  * @edev: EFA communication layer struct
 995  *
 996  * Retrieve the maximum physical address bits the device can handle.
 997  *
 998  * @return: > 0 on Success and negative value otherwise.
 999  */
1000 int efa_com_get_dma_width(struct efa_com_dev *edev)
1001 {
1002         u32 caps = efa_com_reg_read32(edev, EFA_REGS_CAPS_OFF);
1003         int width;
1004
1005         width = (caps & EFA_REGS_CAPS_DMA_ADDR_WIDTH_MASK) >>
1006                 EFA_REGS_CAPS_DMA_ADDR_WIDTH_SHIFT;
1007
1008         ibdev_dbg(edev->efa_dev, "DMA width: %d\n", width);
1009
1010         if (width < 32 || width > 64) {
1011                 ibdev_err(edev->efa_dev, "DMA width illegal value: %d\n", width);
1012                 return -EINVAL;
1013         }
1014
1015         edev->dma_addr_bits = width;
1016
1017         return width;
1018 }
1019
1020 static int wait_for_reset_state(struct efa_com_dev *edev, u32 timeout,
1021                                 u16 exp_state)
1022 {
1023         u32 val, i;
1024
1025         for (i = 0; i < timeout; i++) {
1026                 val = efa_com_reg_read32(edev, EFA_REGS_DEV_STS_OFF);
1027
1028                 if ((val & EFA_REGS_DEV_STS_RESET_IN_PROGRESS_MASK) ==
1029                     exp_state)
1030                         return 0;
1031
1032                 ibdev_dbg(edev->efa_dev, "Reset indication val %d\n", val);
1033                 msleep(EFA_POLL_INTERVAL_MS);
1034         }
1035
1036         return -ETIME;
1037 }
1038
1039 /**
1040  * efa_com_dev_reset - Perform device FLR to the device.
1041  * @edev: EFA communication layer struct
1042  * @reset_reason: Specify what is the trigger for the reset in case of an error.
1043  *
1044  * @return - 0 on success, negative value on failure.
1045  */
1046 int efa_com_dev_reset(struct efa_com_dev *edev,
1047                       enum efa_regs_reset_reason_types reset_reason)
1048 {
1049         u32 stat, timeout, cap, reset_val;
1050         int err;
1051
1052         stat = efa_com_reg_read32(edev, EFA_REGS_DEV_STS_OFF);
1053         cap = efa_com_reg_read32(edev, EFA_REGS_CAPS_OFF);
1054
1055         if (!(stat & EFA_REGS_DEV_STS_READY_MASK)) {
1056                 ibdev_err(edev->efa_dev,
1057                           "Device isn't ready, can't reset device\n");
1058                 return -EINVAL;
1059         }
1060
1061         timeout = (cap & EFA_REGS_CAPS_RESET_TIMEOUT_MASK) >>
1062                   EFA_REGS_CAPS_RESET_TIMEOUT_SHIFT;
1063         if (!timeout) {
1064                 ibdev_err(edev->efa_dev, "Invalid timeout value\n");
1065                 return -EINVAL;
1066         }
1067
1068         /* start reset */
1069         reset_val = EFA_REGS_DEV_CTL_DEV_RESET_MASK;
1070         reset_val |= (reset_reason << EFA_REGS_DEV_CTL_RESET_REASON_SHIFT) &
1071                      EFA_REGS_DEV_CTL_RESET_REASON_MASK;
1072         writel(reset_val, edev->reg_bar + EFA_REGS_DEV_CTL_OFF);
1073
1074         /* reset clears the mmio readless address, restore it */
1075         efa_com_mmio_reg_read_resp_addr_init(edev);
1076
1077         err = wait_for_reset_state(edev, timeout,
1078                                    EFA_REGS_DEV_STS_RESET_IN_PROGRESS_MASK);
1079         if (err) {
1080                 ibdev_err(edev->efa_dev, "Reset indication didn't turn on\n");
1081                 return err;
1082         }
1083
1084         /* reset done */
1085         writel(0, edev->reg_bar + EFA_REGS_DEV_CTL_OFF);
1086         err = wait_for_reset_state(edev, timeout, 0);
1087         if (err) {
1088                 ibdev_err(edev->efa_dev, "Reset indication didn't turn off\n");
1089                 return err;
1090         }
1091
1092         timeout = (cap & EFA_REGS_CAPS_ADMIN_CMD_TO_MASK) >>
1093                   EFA_REGS_CAPS_ADMIN_CMD_TO_SHIFT;
1094         if (timeout)
1095                 /* the resolution of timeout reg is 100ms */
1096                 edev->aq.completion_timeout = timeout * 100000;
1097         else
1098                 edev->aq.completion_timeout = ADMIN_CMD_TIMEOUT_US;
1099
1100         return 0;
1101 }