drivers/usb/host/xhci-dbgcap.c

   1 /**
   2  * xhci-dbgcap.c - xHCI debug capability support
   3  *
   4  * Copyright (C) 2017 Intel Corporation
   5  *
   6  * Author: Lu Baolu <baolu.lu@linux.intel.com>
   7  */
   8 #include <linux/dma-mapping.h>
   9 #include <linux/slab.h>
  10 #include <linux/nls.h>
  11
  12 #include "xhci.h"
  13 #include "xhci-trace.h"
  14 #include "xhci-dbgcap.h"
  15
  16 static inline void *
  17 dbc_dma_alloc_coherent(struct xhci_hcd *xhci, size_t size,
  18                        dma_addr_t *dma_handle, gfp_t flags)
  19 {
  20         void            *vaddr;
  21
  22         vaddr = dma_alloc_coherent(xhci_to_hcd(xhci)->self.sysdev,
  23                                    size, dma_handle, flags);
  24         memset(vaddr, 0, size);
  25         return vaddr;
  26 }
  27
  28 static inline void
  29 dbc_dma_free_coherent(struct xhci_hcd *xhci, size_t size,
  30                       void *cpu_addr, dma_addr_t dma_handle)
  31 {
  32         if (cpu_addr)
  33                 dma_free_coherent(xhci_to_hcd(xhci)->self.sysdev,
  34                                   size, cpu_addr, dma_handle);
  35 }
  36
  37 static u32 xhci_dbc_populate_strings(struct dbc_str_descs *strings)
  38 {
  39         struct usb_string_descriptor    *s_desc;
  40         u32                             string_length;
  41
  42         /* Serial string: */
  43         s_desc = (struct usb_string_descriptor *)strings->serial;
  44         utf8s_to_utf16s(DBC_STRING_SERIAL, strlen(DBC_STRING_SERIAL),
  45                         UTF16_LITTLE_ENDIAN, (wchar_t *)s_desc->wData,
  46                         DBC_MAX_STRING_LENGTH);
  47
  48         s_desc->bLength         = (strlen(DBC_STRING_SERIAL) + 1) * 2;
  49         s_desc->bDescriptorType = USB_DT_STRING;
  50         string_length           = s_desc->bLength;
  51         string_length           <<= 8;
  52
  53         /* Product string: */
  54         s_desc = (struct usb_string_descriptor *)strings->product;
  55         utf8s_to_utf16s(DBC_STRING_PRODUCT, strlen(DBC_STRING_PRODUCT),
  56                         UTF16_LITTLE_ENDIAN, (wchar_t *)s_desc->wData,
  57                         DBC_MAX_STRING_LENGTH);
  58
  59         s_desc->bLength         = (strlen(DBC_STRING_PRODUCT) + 1) * 2;
  60         s_desc->bDescriptorType = USB_DT_STRING;
  61         string_length           += s_desc->bLength;
  62         string_length           <<= 8;
  63
  64         /* Manufacture string: */
  65         s_desc = (struct usb_string_descriptor *)strings->manufacturer;
  66         utf8s_to_utf16s(DBC_STRING_MANUFACTURER,
  67                         strlen(DBC_STRING_MANUFACTURER),
  68                         UTF16_LITTLE_ENDIAN, (wchar_t *)s_desc->wData,
  69                         DBC_MAX_STRING_LENGTH);
  70
  71         s_desc->bLength         = (strlen(DBC_STRING_MANUFACTURER) + 1) * 2;
  72         s_desc->bDescriptorType = USB_DT_STRING;
  73         string_length           += s_desc->bLength;
  74         string_length           <<= 8;
  75
  76         /* String0: */
  77         strings->string0[0]     = 4;
  78         strings->string0[1]     = USB_DT_STRING;
  79         strings->string0[2]     = 0x09;
  80         strings->string0[3]     = 0x04;
  81         string_length           += 4;
  82
  83         return string_length;
  84 }
  85
  86 static void xhci_dbc_init_contexts(struct xhci_hcd *xhci, u32 string_length)
  87 {
  88         struct xhci_dbc         *dbc;
  89         struct dbc_info_context *info;
  90         struct xhci_ep_ctx      *ep_ctx;
  91         u32                     dev_info;
  92         dma_addr_t              deq, dma;
  93         unsigned int            max_burst;
  94
  95         dbc = xhci->dbc;
  96         if (!dbc)
  97                 return;
  98
  99         /* Populate info Context: */
 100         info                    = (struct dbc_info_context *)dbc->ctx->bytes;
 101         dma                     = dbc->string_dma;
 102         info->string0           = cpu_to_le64(dma);
 103         info->manufacturer      = cpu_to_le64(dma + DBC_MAX_STRING_LENGTH);
 104         info->product           = cpu_to_le64(dma + DBC_MAX_STRING_LENGTH * 2);
 105         info->serial            = cpu_to_le64(dma + DBC_MAX_STRING_LENGTH * 3);
 106         info->length            = cpu_to_le32(string_length);
 107
 108         /* Populate bulk out endpoint context: */
 109         ep_ctx                  = dbc_bulkout_ctx(dbc);
 110         max_burst               = DBC_CTRL_MAXBURST(readl(&dbc->regs->control));
 111         deq                     = dbc_bulkout_enq(dbc);
 112         ep_ctx->ep_info         = 0;
 113         ep_ctx->ep_info2        = dbc_epctx_info2(BULK_OUT_EP, 1024, max_burst);
 114         ep_ctx->deq             = cpu_to_le64(deq | dbc->ring_out->cycle_state);
 115
 116         /* Populate bulk in endpoint context: */
 117         ep_ctx                  = dbc_bulkin_ctx(dbc);
 118         deq                     = dbc_bulkin_enq(dbc);
 119         ep_ctx->ep_info         = 0;
 120         ep_ctx->ep_info2        = dbc_epctx_info2(BULK_IN_EP, 1024, max_burst);
 121         ep_ctx->deq             = cpu_to_le64(deq | dbc->ring_in->cycle_state);
 122
 123         /* Set DbC context and info registers: */
 124         xhci_write_64(xhci, dbc->ctx->dma, &dbc->regs->dccp);
 125
 126         dev_info = cpu_to_le32((DBC_VENDOR_ID << 16) | DBC_PROTOCOL);
 127         writel(dev_info, &dbc->regs->devinfo1);
 128
 129         dev_info = cpu_to_le32((DBC_DEVICE_REV << 16) | DBC_PRODUCT_ID);
 130         writel(dev_info, &dbc->regs->devinfo2);
 131 }
 132
 133 static void xhci_dbc_giveback(struct dbc_request *req, int status)
 134         __releases(&dbc->lock)
 135         __acquires(&dbc->lock)
 136 {
 137         struct dbc_ep           *dep = req->dep;
 138         struct xhci_dbc         *dbc = dep->dbc;
 139         struct xhci_hcd         *xhci = dbc->xhci;
 140         struct device           *dev = xhci_to_hcd(dbc->xhci)->self.sysdev;
 141
 142         list_del_init(&req->list_pending);
 143         req->trb_dma = 0;
 144         req->trb = NULL;
 145
 146         if (req->status == -EINPROGRESS)
 147                 req->status = status;
 148
 149         trace_xhci_dbc_giveback_request(req);
 150
 151         dma_unmap_single(dev,
 152                          req->dma,
 153                          req->length,
 154                          dbc_ep_dma_direction(dep));
 155
 156         /* Give back the transfer request: */
 157         spin_unlock(&dbc->lock);
 158         req->complete(xhci, req);
 159         spin_lock(&dbc->lock);
 160 }
 161
 162 static void xhci_dbc_flush_single_request(struct dbc_request *req)
 163 {
 164         union xhci_trb  *trb = req->trb;
 165
 166         trb->generic.field[0]   = 0;
 167         trb->generic.field[1]   = 0;
 168         trb->generic.field[2]   = 0;
 169         trb->generic.field[3]   &= cpu_to_le32(TRB_CYCLE);
 170         trb->generic.field[3]   |= cpu_to_le32(TRB_TYPE(TRB_TR_NOOP));
 171
 172         xhci_dbc_giveback(req, -ESHUTDOWN);
 173 }
 174
 175 static void xhci_dbc_flush_endpoint_requests(struct dbc_ep *dep)
 176 {
 177         struct dbc_request      *req, *tmp;
 178
 179         list_for_each_entry_safe(req, tmp, &dep->list_pending, list_pending)
 180                 xhci_dbc_flush_single_request(req);
 181 }
 182
 183 static void xhci_dbc_flush_reqests(struct xhci_dbc *dbc)
 184 {
 185         xhci_dbc_flush_endpoint_requests(&dbc->eps[BULK_OUT]);
 186         xhci_dbc_flush_endpoint_requests(&dbc->eps[BULK_IN]);
 187 }
 188
 189 struct dbc_request *
 190 dbc_alloc_request(struct dbc_ep *dep, gfp_t gfp_flags)
 191 {
 192         struct dbc_request      *req;
 193
 194         req = kzalloc(sizeof(*req), gfp_flags);
 195         if (!req)
 196                 return NULL;
 197
 198         req->dep = dep;
 199         INIT_LIST_HEAD(&req->list_pending);
 200         INIT_LIST_HEAD(&req->list_pool);
 201         req->direction = dep->direction;
 202
 203         trace_xhci_dbc_alloc_request(req);
 204
 205         return req;
 206 }
 207
 208 void
 209 dbc_free_request(struct dbc_ep *dep, struct dbc_request *req)
 210 {
 211         trace_xhci_dbc_free_request(req);
 212
 213         kfree(req);
 214 }
 215
 216 static void
 217 xhci_dbc_queue_trb(struct xhci_ring *ring, u32 field1,
 218                    u32 field2, u32 field3, u32 field4)
 219 {
 220         union xhci_trb          *trb, *next;
 221
 222         trb = ring->enqueue;
 223         trb->generic.field[0]   = cpu_to_le32(field1);
 224         trb->generic.field[1]   = cpu_to_le32(field2);
 225         trb->generic.field[2]   = cpu_to_le32(field3);
 226         trb->generic.field[3]   = cpu_to_le32(field4);
 227
 228         trace_xhci_dbc_gadget_ep_queue(ring, &trb->generic);
 229
 230         ring->num_trbs_free--;
 231         next = ++(ring->enqueue);
 232         if (TRB_TYPE_LINK_LE32(next->link.control)) {
 233                 next->link.control ^= cpu_to_le32(TRB_CYCLE);
 234                 ring->enqueue = ring->enq_seg->trbs;
 235                 ring->cycle_state ^= 1;
 236         }
 237 }
 238
 239 static int xhci_dbc_queue_bulk_tx(struct dbc_ep *dep,
 240                                   struct dbc_request *req)
 241 {
 242         u64                     addr;
 243         union xhci_trb          *trb;
 244         unsigned int            num_trbs;
 245         struct xhci_dbc         *dbc = dep->dbc;
 246         struct xhci_ring        *ring = dep->ring;
 247         u32                     length, control, cycle;
 248
 249         num_trbs = count_trbs(req->dma, req->length);
 250         WARN_ON(num_trbs != 1);
 251         if (ring->num_trbs_free < num_trbs)
 252                 return -EBUSY;
 253
 254         addr    = req->dma;
 255         trb     = ring->enqueue;
 256         cycle   = ring->cycle_state;
 257         length  = TRB_LEN(req->length);
 258         control = TRB_TYPE(TRB_NORMAL) | TRB_IOC;
 259
 260         if (cycle)
 261                 control &= cpu_to_le32(~TRB_CYCLE);
 262         else
 263                 control |= cpu_to_le32(TRB_CYCLE);
 264
 265         req->trb = ring->enqueue;
 266         req->trb_dma = xhci_trb_virt_to_dma(ring->enq_seg, ring->enqueue);
 267         xhci_dbc_queue_trb(ring,
 268                            lower_32_bits(addr),
 269                            upper_32_bits(addr),
 270                            length, control);
 271
 272         /*
 273          * Add a barrier between writes of trb fields and flipping
 274          * the cycle bit:
 275          */
 276         wmb();
 277
 278         if (cycle)
 279                 trb->generic.field[3] |= cpu_to_le32(TRB_CYCLE);
 280         else
 281                 trb->generic.field[3] &= cpu_to_le32(~TRB_CYCLE);
 282
 283         writel(DBC_DOOR_BELL_TARGET(dep->direction), &dbc->regs->doorbell);
 284
 285         return 0;
 286 }
 287
 288 static int
 289 dbc_ep_do_queue(struct dbc_ep *dep, struct dbc_request *req)
 290 {
 291         int                     ret;
 292         struct device           *dev;
 293         struct xhci_dbc         *dbc = dep->dbc;
 294         struct xhci_hcd         *xhci = dbc->xhci;
 295
 296         dev = xhci_to_hcd(xhci)->self.sysdev;
 297
 298         if (!req->length || !req->buf)
 299                 return -EINVAL;
 300
 301         req->actual             = 0;
 302         req->status             = -EINPROGRESS;
 303
 304         req->dma = dma_map_single(dev,
 305                                   req->buf,
 306                                   req->length,
 307                                   dbc_ep_dma_direction(dep));
 308         if (dma_mapping_error(dev, req->dma)) {
 309                 xhci_err(xhci, "failed to map buffer\n");
 310                 return -EFAULT;
 311         }
 312
 313         ret = xhci_dbc_queue_bulk_tx(dep, req);
 314         if (ret) {
 315                 xhci_err(xhci, "failed to queue trbs\n");
 316                 dma_unmap_single(dev,
 317                                  req->dma,
 318                                  req->length,
 319                                  dbc_ep_dma_direction(dep));
 320                 return -EFAULT;
 321         }
 322
 323         list_add_tail(&req->list_pending, &dep->list_pending);
 324
 325         return 0;
 326 }
 327
 328 int dbc_ep_queue(struct dbc_ep *dep, struct dbc_request *req,
 329                  gfp_t gfp_flags)
 330 {
 331         struct xhci_dbc         *dbc = dep->dbc;
 332         int                     ret = -ESHUTDOWN;
 333
 334         spin_lock(&dbc->lock);
 335         if (dbc->state == DS_CONFIGURED)
 336                 ret = dbc_ep_do_queue(dep, req);
 337         spin_unlock(&dbc->lock);
 338
 339         mod_delayed_work(system_wq, &dbc->event_work, 0);
 340
 341         trace_xhci_dbc_queue_request(req);
 342
 343         return ret;
 344 }
 345
 346 static inline void xhci_dbc_do_eps_init(struct xhci_hcd *xhci, bool direction)
 347 {
 348         struct dbc_ep           *dep;
 349         struct xhci_dbc         *dbc = xhci->dbc;
 350
 351         dep                     = &dbc->eps[direction];
 352         dep->dbc                = dbc;
 353         dep->direction          = direction;
 354         dep->ring               = direction ? dbc->ring_in : dbc->ring_out;
 355
 356         INIT_LIST_HEAD(&dep->list_pending);
 357 }
 358
 359 static void xhci_dbc_eps_init(struct xhci_hcd *xhci)
 360 {
 361         xhci_dbc_do_eps_init(xhci, BULK_OUT);
 362         xhci_dbc_do_eps_init(xhci, BULK_IN);
 363 }
 364
 365 static void xhci_dbc_eps_exit(struct xhci_hcd *xhci)
 366 {
 367         struct xhci_dbc         *dbc = xhci->dbc;
 368
 369         memset(dbc->eps, 0, sizeof(struct dbc_ep) * ARRAY_SIZE(dbc->eps));
 370 }
 371
 372 static int xhci_dbc_mem_init(struct xhci_hcd *xhci, gfp_t flags)
 373 {
 374         int                     ret;
 375         dma_addr_t              deq;
 376         u32                     string_length;
 377         struct xhci_dbc         *dbc = xhci->dbc;
 378
 379         /* Allocate various rings for events and transfers: */
 380         dbc->ring_evt = xhci_ring_alloc(xhci, 1, 1, TYPE_EVENT, 0, flags);
 381         if (!dbc->ring_evt)
 382                 goto evt_fail;
 383
 384         dbc->ring_in = xhci_ring_alloc(xhci, 1, 1, TYPE_BULK, 0, flags);
 385         if (!dbc->ring_in)
 386                 goto in_fail;
 387
 388         dbc->ring_out = xhci_ring_alloc(xhci, 1, 1, TYPE_BULK, 0, flags);
 389         if (!dbc->ring_out)
 390                 goto out_fail;
 391
 392         /* Allocate and populate ERST: */
 393         ret = xhci_alloc_erst(xhci, dbc->ring_evt, &dbc->erst, flags);
 394         if (ret)
 395                 goto erst_fail;
 396
 397         /* Allocate context data structure: */
 398         dbc->ctx = xhci_alloc_container_ctx(xhci, XHCI_CTX_TYPE_DEVICE, flags);
 399         if (!dbc->ctx)
 400                 goto ctx_fail;
 401
 402         /* Allocate the string table: */
 403         dbc->string_size = sizeof(struct dbc_str_descs);
 404         dbc->string = dbc_dma_alloc_coherent(xhci,
 405                                              dbc->string_size,
 406                                              &dbc->string_dma,
 407                                              flags);
 408         if (!dbc->string)
 409                 goto string_fail;
 410
 411         /* Setup ERST register: */
 412         writel(dbc->erst.erst_size, &dbc->regs->ersts);
 413         xhci_write_64(xhci, dbc->erst.erst_dma_addr, &dbc->regs->erstba);
 414         deq = xhci_trb_virt_to_dma(dbc->ring_evt->deq_seg,
 415                                    dbc->ring_evt->dequeue);
 416         xhci_write_64(xhci, deq, &dbc->regs->erdp);
 417
 418         /* Setup strings and contexts: */
 419         string_length = xhci_dbc_populate_strings(dbc->string);
 420         xhci_dbc_init_contexts(xhci, string_length);
 421
 422         mmiowb();
 423
 424         xhci_dbc_eps_init(xhci);
 425         dbc->state = DS_INITIALIZED;
 426
 427         return 0;
 428
 429 string_fail:
 430         xhci_free_container_ctx(xhci, dbc->ctx);
 431         dbc->ctx = NULL;
 432 ctx_fail:
 433         xhci_free_erst(xhci, &dbc->erst);
 434 erst_fail:
 435         xhci_ring_free(xhci, dbc->ring_out);
 436         dbc->ring_out = NULL;
 437 out_fail:
 438         xhci_ring_free(xhci, dbc->ring_in);
 439         dbc->ring_in = NULL;
 440 in_fail:
 441         xhci_ring_free(xhci, dbc->ring_evt);
 442         dbc->ring_evt = NULL;
 443 evt_fail:
 444         return -ENOMEM;
 445 }
 446
 447 static void xhci_dbc_mem_cleanup(struct xhci_hcd *xhci)
 448 {
 449         struct xhci_dbc         *dbc = xhci->dbc;
 450
 451         if (!dbc)
 452                 return;
 453
 454         xhci_dbc_eps_exit(xhci);
 455
 456         if (dbc->string) {
 457                 dbc_dma_free_coherent(xhci,
 458                                       dbc->string_size,
 459                                       dbc->string, dbc->string_dma);
 460                 dbc->string = NULL;
 461         }
 462
 463         xhci_free_container_ctx(xhci, dbc->ctx);
 464         dbc->ctx = NULL;
 465
 466         xhci_free_erst(xhci, &dbc->erst);
 467         xhci_ring_free(xhci, dbc->ring_out);
 468         xhci_ring_free(xhci, dbc->ring_in);
 469         xhci_ring_free(xhci, dbc->ring_evt);
 470         dbc->ring_in = NULL;
 471         dbc->ring_out = NULL;
 472         dbc->ring_evt = NULL;
 473 }
 474
 475 static int xhci_do_dbc_start(struct xhci_hcd *xhci)
 476 {
 477         int                     ret;
 478         u32                     ctrl;
 479         struct xhci_dbc         *dbc = xhci->dbc;
 480
 481         if (dbc->state != DS_DISABLED)
 482                 return -EINVAL;
 483
 484         writel(0, &dbc->regs->control);
 485         ret = xhci_handshake(&dbc->regs->control,
 486                              DBC_CTRL_DBC_ENABLE,
 487                              0, 1000);
 488         if (ret)
 489                 return ret;
 490
 491         ret = xhci_dbc_mem_init(xhci, GFP_ATOMIC);
 492         if (ret)
 493                 return ret;
 494
 495         ctrl = readl(&dbc->regs->control);
 496         writel(ctrl | DBC_CTRL_DBC_ENABLE | DBC_CTRL_PORT_ENABLE,
 497                &dbc->regs->control);
 498         ret = xhci_handshake(&dbc->regs->control,
 499                              DBC_CTRL_DBC_ENABLE,
 500                              DBC_CTRL_DBC_ENABLE, 1000);
 501         if (ret)
 502                 return ret;
 503
 504         dbc->state = DS_ENABLED;
 505
 506         return 0;
 507 }
 508
 509 static void xhci_do_dbc_stop(struct xhci_hcd *xhci)
 510 {
 511         struct xhci_dbc         *dbc = xhci->dbc;
 512
 513         if (dbc->state == DS_DISABLED)
 514                 return;
 515
 516         writel(0, &dbc->regs->control);
 517         xhci_dbc_mem_cleanup(xhci);
 518         dbc->state = DS_DISABLED;
 519 }
 520
 521 static int xhci_dbc_start(struct xhci_hcd *xhci)
 522 {
 523         int                     ret;
 524         struct xhci_dbc         *dbc = xhci->dbc;
 525
 526         WARN_ON(!dbc);
 527
 528         pm_runtime_get_sync(xhci_to_hcd(xhci)->self.controller);
 529
 530         spin_lock(&dbc->lock);
 531         ret = xhci_do_dbc_start(xhci);
 532         spin_unlock(&dbc->lock);
 533
 534         if (ret) {
 535                 pm_runtime_put(xhci_to_hcd(xhci)->self.controller);
 536                 return ret;
 537         }
 538
 539         return mod_delayed_work(system_wq, &dbc->event_work, 1);
 540 }
 541
 542 static void xhci_dbc_stop(struct xhci_hcd *xhci)
 543 {
 544         struct xhci_dbc         *dbc = xhci->dbc;
 545         struct dbc_port         *port = &dbc->port;
 546
 547         WARN_ON(!dbc);
 548
 549         cancel_delayed_work_sync(&dbc->event_work);
 550
 551         if (port->registered)
 552                 xhci_dbc_tty_unregister_device(xhci);
 553
 554         spin_lock(&dbc->lock);
 555         xhci_do_dbc_stop(xhci);
 556         spin_unlock(&dbc->lock);
 557
 558         pm_runtime_put_sync(xhci_to_hcd(xhci)->self.controller);
 559 }
 560
 561 static void
 562 dbc_handle_port_status(struct xhci_hcd *xhci, union xhci_trb *event)
 563 {
 564         u32                     portsc;
 565         struct xhci_dbc         *dbc = xhci->dbc;
 566
 567         portsc = readl(&dbc->regs->portsc);
 568         if (portsc & DBC_PORTSC_CONN_CHANGE)
 569                 xhci_info(xhci, "DbC port connect change\n");
 570
 571         if (portsc & DBC_PORTSC_RESET_CHANGE)
 572                 xhci_info(xhci, "DbC port reset change\n");
 573
 574         if (portsc & DBC_PORTSC_LINK_CHANGE)
 575                 xhci_info(xhci, "DbC port link status change\n");
 576
 577         if (portsc & DBC_PORTSC_CONFIG_CHANGE)
 578                 xhci_info(xhci, "DbC config error change\n");
 579
 580         /* Port reset change bit will be cleared in other place: */
 581         writel(portsc & ~DBC_PORTSC_RESET_CHANGE, &dbc->regs->portsc);
 582 }
 583
 584 static void dbc_handle_xfer_event(struct xhci_hcd *xhci, union xhci_trb *event)
 585 {
 586         struct dbc_ep           *dep;
 587         struct xhci_ring        *ring;
 588         int                     ep_id;
 589         int                     status;
 590         u32                     comp_code;
 591         size_t                  remain_length;
 592         struct dbc_request      *req = NULL, *r;
 593
 594         comp_code       = GET_COMP_CODE(le32_to_cpu(event->generic.field[2]));
 595         remain_length   = EVENT_TRB_LEN(le32_to_cpu(event->generic.field[2]));
 596         ep_id           = TRB_TO_EP_ID(le32_to_cpu(event->generic.field[3]));
 597         dep             = (ep_id == EPID_OUT) ?
 598                                 get_out_ep(xhci) : get_in_ep(xhci);
 599         ring            = dep->ring;
 600
 601         switch (comp_code) {
 602         case COMP_SUCCESS:
 603                 remain_length = 0;
 604         /* FALLTHROUGH */
 605         case COMP_SHORT_PACKET:
 606                 status = 0;
 607                 break;
 608         case COMP_TRB_ERROR:
 609         case COMP_BABBLE_DETECTED_ERROR:
 610         case COMP_USB_TRANSACTION_ERROR:
 611         case COMP_STALL_ERROR:
 612                 xhci_warn(xhci, "tx error %d detected\n", comp_code);
 613                 status = -comp_code;
 614                 break;
 615         default:
 616                 xhci_err(xhci, "unknown tx error %d\n", comp_code);
 617                 status = -comp_code;
 618                 break;
 619         }
 620
 621         /* Match the pending request: */
 622         list_for_each_entry(r, &dep->list_pending, list_pending) {
 623                 if (r->trb_dma == event->trans_event.buffer) {
 624                         req = r;
 625                         break;
 626                 }
 627         }
 628
 629         if (!req) {
 630                 xhci_warn(xhci, "no matched request\n");
 631                 return;
 632         }
 633
 634         trace_xhci_dbc_handle_transfer(ring, &req->trb->generic);
 635
 636         ring->num_trbs_free++;
 637         req->actual = req->length - remain_length;
 638         xhci_dbc_giveback(req, status);
 639 }
 640
 641 static enum evtreturn xhci_dbc_do_handle_events(struct xhci_dbc *dbc)
 642 {
 643         dma_addr_t              deq;
 644         struct dbc_ep           *dep;
 645         union xhci_trb          *evt;
 646         u32                     ctrl, portsc;
 647         struct xhci_hcd         *xhci = dbc->xhci;
 648         bool                    update_erdp = false;
 649
 650         /* DbC state machine: */
 651         switch (dbc->state) {
 652         case DS_DISABLED:
 653         case DS_INITIALIZED:
 654
 655                 return EVT_ERR;
 656         case DS_ENABLED:
 657                 portsc = readl(&dbc->regs->portsc);
 658                 if (portsc & DBC_PORTSC_CONN_STATUS) {
 659                         dbc->state = DS_CONNECTED;
 660                         xhci_info(xhci, "DbC connected\n");
 661                 }
 662
 663                 return EVT_DONE;
 664         case DS_CONNECTED:
 665                 ctrl = readl(&dbc->regs->control);
 666                 if (ctrl & DBC_CTRL_DBC_RUN) {
 667                         dbc->state = DS_CONFIGURED;
 668                         xhci_info(xhci, "DbC configured\n");
 669                         portsc = readl(&dbc->regs->portsc);
 670                         writel(portsc, &dbc->regs->portsc);
 671                         return EVT_GSER;
 672                 }
 673
 674                 return EVT_DONE;
 675         case DS_CONFIGURED:
 676                 /* Handle cable unplug event: */
 677                 portsc = readl(&dbc->regs->portsc);
 678                 if (!(portsc & DBC_PORTSC_PORT_ENABLED) &&
 679                     !(portsc & DBC_PORTSC_CONN_STATUS)) {
 680                         xhci_info(xhci, "DbC cable unplugged\n");
 681                         dbc->state = DS_ENABLED;
 682                         xhci_dbc_flush_reqests(dbc);
 683
 684                         return EVT_DISC;
 685                 }
 686
 687                 /* Handle debug port reset event: */
 688                 if (portsc & DBC_PORTSC_RESET_CHANGE) {
 689                         xhci_info(xhci, "DbC port reset\n");
 690                         writel(portsc, &dbc->regs->portsc);
 691                         dbc->state = DS_ENABLED;
 692                         xhci_dbc_flush_reqests(dbc);
 693
 694                         return EVT_DISC;
 695                 }
 696
 697                 /* Handle endpoint stall event: */
 698                 ctrl = readl(&dbc->regs->control);
 699                 if ((ctrl & DBC_CTRL_HALT_IN_TR) ||
 700                     (ctrl & DBC_CTRL_HALT_OUT_TR)) {
 701                         xhci_info(xhci, "DbC Endpoint stall\n");
 702                         dbc->state = DS_STALLED;
 703
 704                         if (ctrl & DBC_CTRL_HALT_IN_TR) {
 705                                 dep = get_in_ep(xhci);
 706                                 xhci_dbc_flush_endpoint_requests(dep);
 707                         }
 708
 709                         if (ctrl & DBC_CTRL_HALT_OUT_TR) {
 710                                 dep = get_out_ep(xhci);
 711                                 xhci_dbc_flush_endpoint_requests(dep);
 712                         }
 713
 714                         return EVT_DONE;
 715                 }
 716
 717                 /* Clear DbC run change bit: */
 718                 if (ctrl & DBC_CTRL_DBC_RUN_CHANGE) {
 719                         writel(ctrl, &dbc->regs->control);
 720                         ctrl = readl(&dbc->regs->control);
 721                 }
 722
 723                 break;
 724         case DS_STALLED:
 725                 ctrl = readl(&dbc->regs->control);
 726                 if (!(ctrl & DBC_CTRL_HALT_IN_TR) &&
 727                     !(ctrl & DBC_CTRL_HALT_OUT_TR) &&
 728                     (ctrl & DBC_CTRL_DBC_RUN)) {
 729                         dbc->state = DS_CONFIGURED;
 730                         break;
 731                 }
 732
 733                 return EVT_DONE;
 734         default:
 735                 xhci_err(xhci, "Unknown DbC state %d\n", dbc->state);
 736                 break;
 737         }
 738
 739         /* Handle the events in the event ring: */
 740         evt = dbc->ring_evt->dequeue;
 741         while ((le32_to_cpu(evt->event_cmd.flags) & TRB_CYCLE) ==
 742                         dbc->ring_evt->cycle_state) {
 743                 /*
 744                  * Add a barrier between reading the cycle flag and any
 745                  * reads of the event's flags/data below:
 746                  */
 747                 rmb();
 748
 749                 trace_xhci_dbc_handle_event(dbc->ring_evt, &evt->generic);
 750
 751                 switch (le32_to_cpu(evt->event_cmd.flags) & TRB_TYPE_BITMASK) {
 752                 case TRB_TYPE(TRB_PORT_STATUS):
 753                         dbc_handle_port_status(xhci, evt);
 754                         break;
 755                 case TRB_TYPE(TRB_TRANSFER):
 756                         dbc_handle_xfer_event(xhci, evt);
 757                         break;
 758                 default:
 759                         break;
 760                 }
 761
 762                 inc_deq(xhci, dbc->ring_evt);
 763                 evt = dbc->ring_evt->dequeue;
 764                 update_erdp = true;
 765         }
 766
 767         /* Update event ring dequeue pointer: */
 768         if (update_erdp) {
 769                 deq = xhci_trb_virt_to_dma(dbc->ring_evt->deq_seg,
 770                                            dbc->ring_evt->dequeue);
 771                 xhci_write_64(xhci, deq, &dbc->regs->erdp);
 772         }
 773
 774         return EVT_DONE;
 775 }
 776
 777 static void xhci_dbc_handle_events(struct work_struct *work)
 778 {
 779         int                     ret;
 780         enum evtreturn          evtr;
 781         struct xhci_dbc         *dbc;
 782         struct xhci_hcd         *xhci;
 783
 784         dbc = container_of(to_delayed_work(work), struct xhci_dbc, event_work);
 785         xhci = dbc->xhci;
 786
 787         spin_lock(&dbc->lock);
 788         evtr = xhci_dbc_do_handle_events(dbc);
 789         spin_unlock(&dbc->lock);
 790
 791         switch (evtr) {
 792         case EVT_GSER:
 793                 ret = xhci_dbc_tty_register_device(xhci);
 794                 if (ret) {
 795                         xhci_err(xhci, "failed to alloc tty device\n");
 796                         break;
 797                 }
 798
 799                 xhci_info(xhci, "DbC now attached to /dev/ttyDBC0\n");
 800                 break;
 801         case EVT_DISC:
 802                 xhci_dbc_tty_unregister_device(xhci);
 803                 break;
 804         case EVT_DONE:
 805                 break;
 806         default:
 807                 xhci_info(xhci, "stop handling dbc events\n");
 808                 return;
 809         }
 810
 811         mod_delayed_work(system_wq, &dbc->event_work, 1);
 812 }
 813
 814 static void xhci_do_dbc_exit(struct xhci_hcd *xhci)
 815 {
 816         unsigned long           flags;
 817
 818         spin_lock_irqsave(&xhci->lock, flags);
 819         kfree(xhci->dbc);
 820         xhci->dbc = NULL;
 821         spin_unlock_irqrestore(&xhci->lock, flags);
 822 }
 823
 824 static int xhci_do_dbc_init(struct xhci_hcd *xhci)
 825 {
 826         u32                     reg;
 827         struct xhci_dbc         *dbc;
 828         unsigned long           flags;
 829         void __iomem            *base;
 830         int                     dbc_cap_offs;
 831
 832         base = &xhci->cap_regs->hc_capbase;
 833         dbc_cap_offs = xhci_find_next_ext_cap(base, 0, XHCI_EXT_CAPS_DEBUG);
 834         if (!dbc_cap_offs)
 835                 return -ENODEV;
 836
 837         dbc = kzalloc(sizeof(*dbc), GFP_KERNEL);
 838         if (!dbc)
 839                 return -ENOMEM;
 840
 841         dbc->regs = base + dbc_cap_offs;
 842
 843         /* We will avoid using DbC in xhci driver if it's in use. */
 844         reg = readl(&dbc->regs->control);
 845         if (reg & DBC_CTRL_DBC_ENABLE) {
 846                 kfree(dbc);
 847                 return -EBUSY;
 848         }
 849
 850         spin_lock_irqsave(&xhci->lock, flags);
 851         if (xhci->dbc) {
 852                 spin_unlock_irqrestore(&xhci->lock, flags);
 853                 kfree(dbc);
 854                 return -EBUSY;
 855         }
 856         xhci->dbc = dbc;
 857         spin_unlock_irqrestore(&xhci->lock, flags);
 858
 859         dbc->xhci = xhci;
 860         INIT_DELAYED_WORK(&dbc->event_work, xhci_dbc_handle_events);
 861         spin_lock_init(&dbc->lock);
 862
 863         return 0;
 864 }
 865
 866 static ssize_t dbc_show(struct device *dev,
 867                         struct device_attribute *attr,
 868                         char *buf)
 869 {
 870         const char              *p;
 871         struct xhci_dbc         *dbc;
 872         struct xhci_hcd         *xhci;
 873
 874         xhci = hcd_to_xhci(dev_get_drvdata(dev));
 875         dbc = xhci->dbc;
 876
 877         switch (dbc->state) {
 878         case DS_DISABLED:
 879                 p = "disabled";
 880                 break;
 881         case DS_INITIALIZED:
 882                 p = "initialized";
 883                 break;
 884         case DS_ENABLED:
 885                 p = "enabled";
 886                 break;
 887         case DS_CONNECTED:
 888                 p = "connected";
 889                 break;
 890         case DS_CONFIGURED:
 891                 p = "configured";
 892                 break;
 893         case DS_STALLED:
 894                 p = "stalled";
 895                 break;
 896         default:
 897                 p = "unknown";
 898         }
 899
 900         return sprintf(buf, "%s\n", p);
 901 }
 902
 903 static ssize_t dbc_store(struct device *dev,
 904                          struct device_attribute *attr,
 905                          const char *buf, size_t count)
 906 {
 907         struct xhci_dbc         *dbc;
 908         struct xhci_hcd         *xhci;
 909
 910         xhci = hcd_to_xhci(dev_get_drvdata(dev));
 911         dbc = xhci->dbc;
 912
 913         if (!strncmp(buf, "enable", 6))
 914                 xhci_dbc_start(xhci);
 915         else if (!strncmp(buf, "disable", 7))
 916                 xhci_dbc_stop(xhci);
 917         else
 918                 return -EINVAL;
 919
 920         return count;
 921 }
 922
 923 static DEVICE_ATTR_RW(dbc);
 924
 925 int xhci_dbc_init(struct xhci_hcd *xhci)
 926 {
 927         int                     ret;
 928         struct device           *dev = xhci_to_hcd(xhci)->self.controller;
 929
 930         ret = xhci_do_dbc_init(xhci);
 931         if (ret)
 932                 goto init_err3;
 933
 934         ret = xhci_dbc_tty_register_driver(xhci);
 935         if (ret)
 936                 goto init_err2;
 937
 938         ret = device_create_file(dev, &dev_attr_dbc);
 939         if (ret)
 940                 goto init_err1;
 941
 942         return 0;
 943
 944 init_err1:
 945         xhci_dbc_tty_unregister_driver();
 946 init_err2:
 947         xhci_do_dbc_exit(xhci);
 948 init_err3:
 949         return ret;
 950 }
 951
 952 void xhci_dbc_exit(struct xhci_hcd *xhci)
 953 {
 954         struct device           *dev = xhci_to_hcd(xhci)->self.controller;
 955
 956         if (!xhci->dbc)
 957                 return;
 958
 959         device_remove_file(dev, &dev_attr_dbc);
 960         xhci_dbc_tty_unregister_driver();
 961         xhci_dbc_stop(xhci);
 962         xhci_do_dbc_exit(xhci);
 963 }
 964
 965 #ifdef CONFIG_PM
 966 int xhci_dbc_suspend(struct xhci_hcd *xhci)
 967 {
 968         struct xhci_dbc         *dbc = xhci->dbc;
 969
 970         if (!dbc)
 971                 return 0;
 972
 973         if (dbc->state == DS_CONFIGURED)
 974                 dbc->resume_required = 1;
 975
 976         xhci_dbc_stop(xhci);
 977
 978         return 0;
 979 }
 980
 981 int xhci_dbc_resume(struct xhci_hcd *xhci)
 982 {
 983         int                     ret = 0;
 984         struct xhci_dbc         *dbc = xhci->dbc;
 985
 986         if (!dbc)
 987                 return 0;
 988
 989         if (dbc->resume_required) {
 990                 dbc->resume_required = 0;
 991                 xhci_dbc_start(xhci);
 992         }
 993
 994         return ret;
 995 }
 996 #endif /* CONFIG_PM */