drivers/thunderbolt/nhi.c

   1 /*
   2  * Thunderbolt driver - NHI driver
   3  *
   4  * The NHI (native host interface) is the pci device that allows us to send and
   5  * receive frames from the thunderbolt bus.
   6  *
   7  * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
   8  * Copyright (C) 2018, Intel Corporation
   9  */
  10
  11 #include <linux/pm_runtime.h>
  12 #include <linux/slab.h>
  13 #include <linux/errno.h>
  14 #include <linux/pci.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/module.h>
  17 #include <linux/delay.h>
  18
  19 #include "nhi.h"
  20 #include "nhi_regs.h"
  21 #include "tb.h"
  22
  23 #define RING_TYPE(ring) ((ring)->is_tx ? "TX ring" : "RX ring")
  24
  25 /*
  26  * Used to enable end-to-end workaround for missing RX packets. Do not
  27  * use this ring for anything else.
  28  */
  29 #define RING_E2E_UNUSED_HOPID   2
  30 /* HopIDs 0-7 are reserved by the Thunderbolt protocol */
  31 #define RING_FIRST_USABLE_HOPID 8
  32
  33 /*
  34  * Minimal number of vectors when we use MSI-X. Two for control channel
  35  * Rx/Tx and the rest four are for cross domain DMA paths.
  36  */
  37 #define MSIX_MIN_VECS           6
  38 #define MSIX_MAX_VECS           16
  39
  40 #define NHI_MAILBOX_TIMEOUT     500 /* ms */
  41
  42 static int ring_interrupt_index(struct tb_ring *ring)
  43 {
  44         int bit = ring->hop;
  45         if (!ring->is_tx)
  46                 bit += ring->nhi->hop_count;
  47         return bit;
  48 }
  49
  50 /**
  51  * ring_interrupt_active() - activate/deactivate interrupts for a single ring
  52  *
  53  * ring->nhi->lock must be held.
  54  */
  55 static void ring_interrupt_active(struct tb_ring *ring, bool active)
  56 {
  57         int reg = REG_RING_INTERRUPT_BASE +
  58                   ring_interrupt_index(ring) / 32 * 4;
  59         int bit = ring_interrupt_index(ring) & 31;
  60         int mask = 1 << bit;
  61         u32 old, new;
  62
  63         if (ring->irq > 0) {
  64                 u32 step, shift, ivr, misc;
  65                 void __iomem *ivr_base;
  66                 int index;
  67
  68                 if (ring->is_tx)
  69                         index = ring->hop;
  70                 else
  71                         index = ring->hop + ring->nhi->hop_count;
  72
  73                 /*
  74                  * Ask the hardware to clear interrupt status bits automatically
  75                  * since we already know which interrupt was triggered.
  76                  */
  77                 misc = ioread32(ring->nhi->iobase + REG_DMA_MISC);
  78                 if (!(misc & REG_DMA_MISC_INT_AUTO_CLEAR)) {
  79                         misc |= REG_DMA_MISC_INT_AUTO_CLEAR;
  80                         iowrite32(misc, ring->nhi->iobase + REG_DMA_MISC);
  81                 }
  82
  83                 ivr_base = ring->nhi->iobase + REG_INT_VEC_ALLOC_BASE;
  84                 step = index / REG_INT_VEC_ALLOC_REGS * REG_INT_VEC_ALLOC_BITS;
  85                 shift = index % REG_INT_VEC_ALLOC_REGS * REG_INT_VEC_ALLOC_BITS;
  86                 ivr = ioread32(ivr_base + step);
  87                 ivr &= ~(REG_INT_VEC_ALLOC_MASK << shift);
  88                 if (active)
  89                         ivr |= ring->vector << shift;
  90                 iowrite32(ivr, ivr_base + step);
  91         }
  92
  93         old = ioread32(ring->nhi->iobase + reg);
  94         if (active)
  95                 new = old | mask;
  96         else
  97                 new = old & ~mask;
  98
  99         dev_dbg(&ring->nhi->pdev->dev,
 100                 "%s interrupt at register %#x bit %d (%#x -> %#x)\n",
 101                 active ? "enabling" : "disabling", reg, bit, old, new);
 102
 103         if (new == old)
 104                 dev_WARN(&ring->nhi->pdev->dev,
 105                                          "interrupt for %s %d is already %s\n",
 106                                          RING_TYPE(ring), ring->hop,
 107                                          active ? "enabled" : "disabled");
 108         iowrite32(new, ring->nhi->iobase + reg);
 109 }
 110
 111 /**
 112  * nhi_disable_interrupts() - disable interrupts for all rings
 113  *
 114  * Use only during init and shutdown.
 115  */
 116 static void nhi_disable_interrupts(struct tb_nhi *nhi)
 117 {
 118         int i = 0;
 119         /* disable interrupts */
 120         for (i = 0; i < RING_INTERRUPT_REG_COUNT(nhi); i++)
 121                 iowrite32(0, nhi->iobase + REG_RING_INTERRUPT_BASE + 4 * i);
 122
 123         /* clear interrupt status bits */
 124         for (i = 0; i < RING_NOTIFY_REG_COUNT(nhi); i++)
 125                 ioread32(nhi->iobase + REG_RING_NOTIFY_BASE + 4 * i);
 126 }
 127
 128 /* ring helper methods */
 129
 130 static void __iomem *ring_desc_base(struct tb_ring *ring)
 131 {
 132         void __iomem *io = ring->nhi->iobase;
 133         io += ring->is_tx ? REG_TX_RING_BASE : REG_RX_RING_BASE;
 134         io += ring->hop * 16;
 135         return io;
 136 }
 137
 138 static void __iomem *ring_options_base(struct tb_ring *ring)
 139 {
 140         void __iomem *io = ring->nhi->iobase;
 141         io += ring->is_tx ? REG_TX_OPTIONS_BASE : REG_RX_OPTIONS_BASE;
 142         io += ring->hop * 32;
 143         return io;
 144 }
 145
 146 static void ring_iowrite16desc(struct tb_ring *ring, u32 value, u32 offset)
 147 {
 148         iowrite16(value, ring_desc_base(ring) + offset);
 149 }
 150
 151 static void ring_iowrite32desc(struct tb_ring *ring, u32 value, u32 offset)
 152 {
 153         iowrite32(value, ring_desc_base(ring) + offset);
 154 }
 155
 156 static void ring_iowrite64desc(struct tb_ring *ring, u64 value, u32 offset)
 157 {
 158         iowrite32(value, ring_desc_base(ring) + offset);
 159         iowrite32(value >> 32, ring_desc_base(ring) + offset + 4);
 160 }
 161
 162 static void ring_iowrite32options(struct tb_ring *ring, u32 value, u32 offset)
 163 {
 164         iowrite32(value, ring_options_base(ring) + offset);
 165 }
 166
 167 static bool ring_full(struct tb_ring *ring)
 168 {
 169         return ((ring->head + 1) % ring->size) == ring->tail;
 170 }
 171
 172 static bool ring_empty(struct tb_ring *ring)
 173 {
 174         return ring->head == ring->tail;
 175 }
 176
 177 /**
 178  * ring_write_descriptors() - post frames from ring->queue to the controller
 179  *
 180  * ring->lock is held.
 181  */
 182 static void ring_write_descriptors(struct tb_ring *ring)
 183 {
 184         struct ring_frame *frame, *n;
 185         struct ring_desc *descriptor;
 186         list_for_each_entry_safe(frame, n, &ring->queue, list) {
 187                 if (ring_full(ring))
 188                         break;
 189                 list_move_tail(&frame->list, &ring->in_flight);
 190                 descriptor = &ring->descriptors[ring->head];
 191                 descriptor->phys = frame->buffer_phy;
 192                 descriptor->time = 0;
 193                 descriptor->flags = RING_DESC_POSTED | RING_DESC_INTERRUPT;
 194                 if (ring->is_tx) {
 195                         descriptor->length = frame->size;
 196                         descriptor->eof = frame->eof;
 197                         descriptor->sof = frame->sof;
 198                 }
 199                 ring->head = (ring->head + 1) % ring->size;
 200                 ring_iowrite16desc(ring, ring->head, ring->is_tx ? 10 : 8);
 201         }
 202 }
 203
 204 /**
 205  * ring_work() - progress completed frames
 206  *
 207  * If the ring is shutting down then all frames are marked as canceled and
 208  * their callbacks are invoked.
 209  *
 210  * Otherwise we collect all completed frame from the ring buffer, write new
 211  * frame to the ring buffer and invoke the callbacks for the completed frames.
 212  */
 213 static void ring_work(struct work_struct *work)
 214 {
 215         struct tb_ring *ring = container_of(work, typeof(*ring), work);
 216         struct ring_frame *frame;
 217         bool canceled = false;
 218         unsigned long flags;
 219         LIST_HEAD(done);
 220
 221         spin_lock_irqsave(&ring->lock, flags);
 222
 223         if (!ring->running) {
 224                 /*  Move all frames to done and mark them as canceled. */
 225                 list_splice_tail_init(&ring->in_flight, &done);
 226                 list_splice_tail_init(&ring->queue, &done);
 227                 canceled = true;
 228                 goto invoke_callback;
 229         }
 230
 231         while (!ring_empty(ring)) {
 232                 if (!(ring->descriptors[ring->tail].flags
 233                                 & RING_DESC_COMPLETED))
 234                         break;
 235                 frame = list_first_entry(&ring->in_flight, typeof(*frame),
 236                                          list);
 237                 list_move_tail(&frame->list, &done);
 238                 if (!ring->is_tx) {
 239                         frame->size = ring->descriptors[ring->tail].length;
 240                         frame->eof = ring->descriptors[ring->tail].eof;
 241                         frame->sof = ring->descriptors[ring->tail].sof;
 242                         frame->flags = ring->descriptors[ring->tail].flags;
 243                 }
 244                 ring->tail = (ring->tail + 1) % ring->size;
 245         }
 246         ring_write_descriptors(ring);
 247
 248 invoke_callback:
 249         /* allow callbacks to schedule new work */
 250         spin_unlock_irqrestore(&ring->lock, flags);
 251         while (!list_empty(&done)) {
 252                 frame = list_first_entry(&done, typeof(*frame), list);
 253                 /*
 254                  * The callback may reenqueue or delete frame.
 255                  * Do not hold on to it.
 256                  */
 257                 list_del_init(&frame->list);
 258                 if (frame->callback)
 259                         frame->callback(ring, frame, canceled);
 260         }
 261 }
 262
 263 int __tb_ring_enqueue(struct tb_ring *ring, struct ring_frame *frame)
 264 {
 265         unsigned long flags;
 266         int ret = 0;
 267
 268         spin_lock_irqsave(&ring->lock, flags);
 269         if (ring->running) {
 270                 list_add_tail(&frame->list, &ring->queue);
 271                 ring_write_descriptors(ring);
 272         } else {
 273                 ret = -ESHUTDOWN;
 274         }
 275         spin_unlock_irqrestore(&ring->lock, flags);
 276         return ret;
 277 }
 278 EXPORT_SYMBOL_GPL(__tb_ring_enqueue);
 279
 280 /**
 281  * tb_ring_poll() - Poll one completed frame from the ring
 282  * @ring: Ring to poll
 283  *
 284  * This function can be called when @start_poll callback of the @ring
 285  * has been called. It will read one completed frame from the ring and
 286  * return it to the caller. Returns %NULL if there is no more completed
 287  * frames.
 288  */
 289 struct ring_frame *tb_ring_poll(struct tb_ring *ring)
 290 {
 291         struct ring_frame *frame = NULL;
 292         unsigned long flags;
 293
 294         spin_lock_irqsave(&ring->lock, flags);
 295         if (!ring->running)
 296                 goto unlock;
 297         if (ring_empty(ring))
 298                 goto unlock;
 299
 300         if (ring->descriptors[ring->tail].flags & RING_DESC_COMPLETED) {
 301                 frame = list_first_entry(&ring->in_flight, typeof(*frame),
 302                                          list);
 303                 list_del_init(&frame->list);
 304
 305                 if (!ring->is_tx) {
 306                         frame->size = ring->descriptors[ring->tail].length;
 307                         frame->eof = ring->descriptors[ring->tail].eof;
 308                         frame->sof = ring->descriptors[ring->tail].sof;
 309                         frame->flags = ring->descriptors[ring->tail].flags;
 310                 }
 311
 312                 ring->tail = (ring->tail + 1) % ring->size;
 313         }
 314
 315 unlock:
 316         spin_unlock_irqrestore(&ring->lock, flags);
 317         return frame;
 318 }
 319 EXPORT_SYMBOL_GPL(tb_ring_poll);
 320
 321 static void __ring_interrupt_mask(struct tb_ring *ring, bool mask)
 322 {
 323         int idx = ring_interrupt_index(ring);
 324         int reg = REG_RING_INTERRUPT_BASE + idx / 32 * 4;
 325         int bit = idx % 32;
 326         u32 val;
 327
 328         val = ioread32(ring->nhi->iobase + reg);
 329         if (mask)
 330                 val &= ~BIT(bit);
 331         else
 332                 val |= BIT(bit);
 333         iowrite32(val, ring->nhi->iobase + reg);
 334 }
 335
 336 /* Both @nhi->lock and @ring->lock should be held */
 337 static void __ring_interrupt(struct tb_ring *ring)
 338 {
 339         if (!ring->running)
 340                 return;
 341
 342         if (ring->start_poll) {
 343                 __ring_interrupt_mask(ring, true);
 344                 ring->start_poll(ring->poll_data);
 345         } else {
 346                 schedule_work(&ring->work);
 347         }
 348 }
 349
 350 /**
 351  * tb_ring_poll_complete() - Re-start interrupt for the ring
 352  * @ring: Ring to re-start the interrupt
 353  *
 354  * This will re-start (unmask) the ring interrupt once the user is done
 355  * with polling.
 356  */
 357 void tb_ring_poll_complete(struct tb_ring *ring)
 358 {
 359         unsigned long flags;
 360
 361         spin_lock_irqsave(&ring->nhi->lock, flags);
 362         spin_lock(&ring->lock);
 363         if (ring->start_poll)
 364                 __ring_interrupt_mask(ring, false);
 365         spin_unlock(&ring->lock);
 366         spin_unlock_irqrestore(&ring->nhi->lock, flags);
 367 }
 368 EXPORT_SYMBOL_GPL(tb_ring_poll_complete);
 369
 370 static irqreturn_t ring_msix(int irq, void *data)
 371 {
 372         struct tb_ring *ring = data;
 373
 374         spin_lock(&ring->nhi->lock);
 375         spin_lock(&ring->lock);
 376         __ring_interrupt(ring);
 377         spin_unlock(&ring->lock);
 378         spin_unlock(&ring->nhi->lock);
 379
 380         return IRQ_HANDLED;
 381 }
 382
 383 static int ring_request_msix(struct tb_ring *ring, bool no_suspend)
 384 {
 385         struct tb_nhi *nhi = ring->nhi;
 386         unsigned long irqflags;
 387         int ret;
 388
 389         if (!nhi->pdev->msix_enabled)
 390                 return 0;
 391
 392         ret = ida_simple_get(&nhi->msix_ida, 0, MSIX_MAX_VECS, GFP_KERNEL);
 393         if (ret < 0)
 394                 return ret;
 395
 396         ring->vector = ret;
 397
 398         ring->irq = pci_irq_vector(ring->nhi->pdev, ring->vector);
 399         if (ring->irq < 0)
 400                 return ring->irq;
 401
 402         irqflags = no_suspend ? IRQF_NO_SUSPEND : 0;
 403         return request_irq(ring->irq, ring_msix, irqflags, "thunderbolt", ring);
 404 }
 405
 406 static void ring_release_msix(struct tb_ring *ring)
 407 {
 408         if (ring->irq <= 0)
 409                 return;
 410
 411         free_irq(ring->irq, ring);
 412         ida_simple_remove(&ring->nhi->msix_ida, ring->vector);
 413         ring->vector = 0;
 414         ring->irq = 0;
 415 }
 416
 417 static int nhi_alloc_hop(struct tb_nhi *nhi, struct tb_ring *ring)
 418 {
 419         int ret = 0;
 420
 421         spin_lock_irq(&nhi->lock);
 422
 423         if (ring->hop < 0) {
 424                 unsigned int i;
 425
 426                 /*
 427                  * Automatically allocate HopID from the non-reserved
 428                  * range 8 .. hop_count - 1.
 429                  */
 430                 for (i = RING_FIRST_USABLE_HOPID; i < nhi->hop_count; i++) {
 431                         if (ring->is_tx) {
 432                                 if (!nhi->tx_rings[i]) {
 433                                         ring->hop = i;
 434                                         break;
 435                                 }
 436                         } else {
 437                                 if (!nhi->rx_rings[i]) {
 438                                         ring->hop = i;
 439                                         break;
 440                                 }
 441                         }
 442                 }
 443         }
 444
 445         if (ring->hop < 0 || ring->hop >= nhi->hop_count) {
 446                 dev_warn(&nhi->pdev->dev, "invalid hop: %d\n", ring->hop);
 447                 ret = -EINVAL;
 448                 goto err_unlock;
 449         }
 450         if (ring->is_tx && nhi->tx_rings[ring->hop]) {
 451                 dev_warn(&nhi->pdev->dev, "TX hop %d already allocated\n",
 452                          ring->hop);
 453                 ret = -EBUSY;
 454                 goto err_unlock;
 455         } else if (!ring->is_tx && nhi->rx_rings[ring->hop]) {
 456                 dev_warn(&nhi->pdev->dev, "RX hop %d already allocated\n",
 457                          ring->hop);
 458                 ret = -EBUSY;
 459                 goto err_unlock;
 460         }
 461
 462         if (ring->is_tx)
 463                 nhi->tx_rings[ring->hop] = ring;
 464         else
 465                 nhi->rx_rings[ring->hop] = ring;
 466
 467 err_unlock:
 468         spin_unlock_irq(&nhi->lock);
 469
 470         return ret;
 471 }
 472
 473 static struct tb_ring *tb_ring_alloc(struct tb_nhi *nhi, u32 hop, int size,
 474                                      bool transmit, unsigned int flags,
 475                                      u16 sof_mask, u16 eof_mask,
 476                                      void (*start_poll)(void *),
 477                                      void *poll_data)
 478 {
 479         struct tb_ring *ring = NULL;
 480
 481         dev_dbg(&nhi->pdev->dev, "allocating %s ring %d of size %d\n",
 482                 transmit ? "TX" : "RX", hop, size);
 483
 484         /* Tx Ring 2 is reserved for E2E workaround */
 485         if (transmit && hop == RING_E2E_UNUSED_HOPID)
 486                 return NULL;
 487
 488         ring = kzalloc(sizeof(*ring), GFP_KERNEL);
 489         if (!ring)
 490                 return NULL;
 491
 492         spin_lock_init(&ring->lock);
 493         INIT_LIST_HEAD(&ring->queue);
 494         INIT_LIST_HEAD(&ring->in_flight);
 495         INIT_WORK(&ring->work, ring_work);
 496
 497         ring->nhi = nhi;
 498         ring->hop = hop;
 499         ring->is_tx = transmit;
 500         ring->size = size;
 501         ring->flags = flags;
 502         ring->sof_mask = sof_mask;
 503         ring->eof_mask = eof_mask;
 504         ring->head = 0;
 505         ring->tail = 0;
 506         ring->running = false;
 507         ring->start_poll = start_poll;
 508         ring->poll_data = poll_data;
 509
 510         ring->descriptors = dma_alloc_coherent(&ring->nhi->pdev->dev,
 511                         size * sizeof(*ring->descriptors),
 512                         &ring->descriptors_dma, GFP_KERNEL | __GFP_ZERO);
 513         if (!ring->descriptors)
 514                 goto err_free_ring;
 515
 516         if (ring_request_msix(ring, flags & RING_FLAG_NO_SUSPEND))
 517                 goto err_free_descs;
 518
 519         if (nhi_alloc_hop(nhi, ring))
 520                 goto err_release_msix;
 521
 522         return ring;
 523
 524 err_release_msix:
 525         ring_release_msix(ring);
 526 err_free_descs:
 527         dma_free_coherent(&ring->nhi->pdev->dev,
 528                           ring->size * sizeof(*ring->descriptors),
 529                           ring->descriptors, ring->descriptors_dma);
 530 err_free_ring:
 531         kfree(ring);
 532
 533         return NULL;
 534 }
 535
 536 /**
 537  * tb_ring_alloc_tx() - Allocate DMA ring for transmit
 538  * @nhi: Pointer to the NHI the ring is to be allocated
 539  * @hop: HopID (ring) to allocate
 540  * @size: Number of entries in the ring
 541  * @flags: Flags for the ring
 542  */
 543 struct tb_ring *tb_ring_alloc_tx(struct tb_nhi *nhi, int hop, int size,
 544                                  unsigned int flags)
 545 {
 546         return tb_ring_alloc(nhi, hop, size, true, flags, 0, 0, NULL, NULL);
 547 }
 548 EXPORT_SYMBOL_GPL(tb_ring_alloc_tx);
 549
 550 /**
 551  * tb_ring_alloc_rx() - Allocate DMA ring for receive
 552  * @nhi: Pointer to the NHI the ring is to be allocated
 553  * @hop: HopID (ring) to allocate. Pass %-1 for automatic allocation.
 554  * @size: Number of entries in the ring
 555  * @flags: Flags for the ring
 556  * @sof_mask: Mask of PDF values that start a frame
 557  * @eof_mask: Mask of PDF values that end a frame
 558  * @start_poll: If not %NULL the ring will call this function when an
 559  *              interrupt is triggered and masked, instead of callback
 560  *              in each Rx frame.
 561  * @poll_data: Optional data passed to @start_poll
 562  */
 563 struct tb_ring *tb_ring_alloc_rx(struct tb_nhi *nhi, int hop, int size,
 564                                  unsigned int flags, u16 sof_mask, u16 eof_mask,
 565                                  void (*start_poll)(void *), void *poll_data)
 566 {
 567         return tb_ring_alloc(nhi, hop, size, false, flags, sof_mask, eof_mask,
 568                              start_poll, poll_data);
 569 }
 570 EXPORT_SYMBOL_GPL(tb_ring_alloc_rx);
 571
 572 /**
 573  * tb_ring_start() - enable a ring
 574  *
 575  * Must not be invoked in parallel with tb_ring_stop().
 576  */
 577 void tb_ring_start(struct tb_ring *ring)
 578 {
 579         u16 frame_size;
 580         u32 flags;
 581
 582         spin_lock_irq(&ring->nhi->lock);
 583         spin_lock(&ring->lock);
 584         if (ring->nhi->going_away)
 585                 goto err;
 586         if (ring->running) {
 587                 dev_WARN(&ring->nhi->pdev->dev, "ring already started\n");
 588                 goto err;
 589         }
 590         dev_dbg(&ring->nhi->pdev->dev, "starting %s %d\n",
 591                 RING_TYPE(ring), ring->hop);
 592
 593         if (ring->flags & RING_FLAG_FRAME) {
 594                 /* Means 4096 */
 595                 frame_size = 0;
 596                 flags = RING_FLAG_ENABLE;
 597         } else {
 598                 frame_size = TB_FRAME_SIZE;
 599                 flags = RING_FLAG_ENABLE | RING_FLAG_RAW;
 600         }
 601
 602         if (ring->flags & RING_FLAG_E2E && !ring->is_tx) {
 603                 u32 hop;
 604
 605                 /*
 606                  * In order not to lose Rx packets we enable end-to-end
 607                  * workaround which transfers Rx credits to an unused Tx
 608                  * HopID.
 609                  */
 610                 hop = RING_E2E_UNUSED_HOPID << REG_RX_OPTIONS_E2E_HOP_SHIFT;
 611                 hop &= REG_RX_OPTIONS_E2E_HOP_MASK;
 612                 flags |= hop | RING_FLAG_E2E_FLOW_CONTROL;
 613         }
 614
 615         ring_iowrite64desc(ring, ring->descriptors_dma, 0);
 616         if (ring->is_tx) {
 617                 ring_iowrite32desc(ring, ring->size, 12);
 618                 ring_iowrite32options(ring, 0, 4); /* time releated ? */
 619                 ring_iowrite32options(ring, flags, 0);
 620         } else {
 621                 u32 sof_eof_mask = ring->sof_mask << 16 | ring->eof_mask;
 622
 623                 ring_iowrite32desc(ring, (frame_size << 16) | ring->size, 12);
 624                 ring_iowrite32options(ring, sof_eof_mask, 4);
 625                 ring_iowrite32options(ring, flags, 0);
 626         }
 627         ring_interrupt_active(ring, true);
 628         ring->running = true;
 629 err:
 630         spin_unlock(&ring->lock);
 631         spin_unlock_irq(&ring->nhi->lock);
 632 }
 633 EXPORT_SYMBOL_GPL(tb_ring_start);
 634
 635 /**
 636  * tb_ring_stop() - shutdown a ring
 637  *
 638  * Must not be invoked from a callback.
 639  *
 640  * This method will disable the ring. Further calls to
 641  * tb_ring_tx/tb_ring_rx will return -ESHUTDOWN until ring_stop has been
 642  * called.
 643  *
 644  * All enqueued frames will be canceled and their callbacks will be executed
 645  * with frame->canceled set to true (on the callback thread). This method
 646  * returns only after all callback invocations have finished.
 647  */
 648 void tb_ring_stop(struct tb_ring *ring)
 649 {
 650         spin_lock_irq(&ring->nhi->lock);
 651         spin_lock(&ring->lock);
 652         dev_dbg(&ring->nhi->pdev->dev, "stopping %s %d\n",
 653                 RING_TYPE(ring), ring->hop);
 654         if (ring->nhi->going_away)
 655                 goto err;
 656         if (!ring->running) {
 657                 dev_WARN(&ring->nhi->pdev->dev, "%s %d already stopped\n",
 658                          RING_TYPE(ring), ring->hop);
 659                 goto err;
 660         }
 661         ring_interrupt_active(ring, false);
 662
 663         ring_iowrite32options(ring, 0, 0);
 664         ring_iowrite64desc(ring, 0, 0);
 665         ring_iowrite16desc(ring, 0, ring->is_tx ? 10 : 8);
 666         ring_iowrite32desc(ring, 0, 12);
 667         ring->head = 0;
 668         ring->tail = 0;
 669         ring->running = false;
 670
 671 err:
 672         spin_unlock(&ring->lock);
 673         spin_unlock_irq(&ring->nhi->lock);
 674
 675         /*
 676          * schedule ring->work to invoke callbacks on all remaining frames.
 677          */
 678         schedule_work(&ring->work);
 679         flush_work(&ring->work);
 680 }
 681 EXPORT_SYMBOL_GPL(tb_ring_stop);
 682
 683 /*
 684  * tb_ring_free() - free ring
 685  *
 686  * When this method returns all invocations of ring->callback will have
 687  * finished.
 688  *
 689  * Ring must be stopped.
 690  *
 691  * Must NOT be called from ring_frame->callback!
 692  */
 693 void tb_ring_free(struct tb_ring *ring)
 694 {
 695         spin_lock_irq(&ring->nhi->lock);
 696         /*
 697          * Dissociate the ring from the NHI. This also ensures that
 698          * nhi_interrupt_work cannot reschedule ring->work.
 699          */
 700         if (ring->is_tx)
 701                 ring->nhi->tx_rings[ring->hop] = NULL;
 702         else
 703                 ring->nhi->rx_rings[ring->hop] = NULL;
 704
 705         if (ring->running) {
 706                 dev_WARN(&ring->nhi->pdev->dev, "%s %d still running\n",
 707                          RING_TYPE(ring), ring->hop);
 708         }
 709         spin_unlock_irq(&ring->nhi->lock);
 710
 711         ring_release_msix(ring);
 712
 713         dma_free_coherent(&ring->nhi->pdev->dev,
 714                           ring->size * sizeof(*ring->descriptors),
 715                           ring->descriptors, ring->descriptors_dma);
 716
 717         ring->descriptors = NULL;
 718         ring->descriptors_dma = 0;
 719
 720
 721         dev_dbg(&ring->nhi->pdev->dev, "freeing %s %d\n", RING_TYPE(ring),
 722                 ring->hop);
 723
 724         /**
 725          * ring->work can no longer be scheduled (it is scheduled only
 726          * by nhi_interrupt_work, ring_stop and ring_msix). Wait for it
 727          * to finish before freeing the ring.
 728          */
 729         flush_work(&ring->work);
 730         kfree(ring);
 731 }
 732 EXPORT_SYMBOL_GPL(tb_ring_free);
 733
 734 /**
 735  * nhi_mailbox_cmd() - Send a command through NHI mailbox
 736  * @nhi: Pointer to the NHI structure
 737  * @cmd: Command to send
 738  * @data: Data to be send with the command
 739  *
 740  * Sends mailbox command to the firmware running on NHI. Returns %0 in
 741  * case of success and negative errno in case of failure.
 742  */
 743 int nhi_mailbox_cmd(struct tb_nhi *nhi, enum nhi_mailbox_cmd cmd, u32 data)
 744 {
 745         ktime_t timeout;
 746         u32 val;
 747
 748         iowrite32(data, nhi->iobase + REG_INMAIL_DATA);
 749
 750         val = ioread32(nhi->iobase + REG_INMAIL_CMD);
 751         val &= ~(REG_INMAIL_CMD_MASK | REG_INMAIL_ERROR);
 752         val |= REG_INMAIL_OP_REQUEST | cmd;
 753         iowrite32(val, nhi->iobase + REG_INMAIL_CMD);
 754
 755         timeout = ktime_add_ms(ktime_get(), NHI_MAILBOX_TIMEOUT);
 756         do {
 757                 val = ioread32(nhi->iobase + REG_INMAIL_CMD);
 758                 if (!(val & REG_INMAIL_OP_REQUEST))
 759                         break;
 760                 usleep_range(10, 20);
 761         } while (ktime_before(ktime_get(), timeout));
 762
 763         if (val & REG_INMAIL_OP_REQUEST)
 764                 return -ETIMEDOUT;
 765         if (val & REG_INMAIL_ERROR)
 766                 return -EIO;
 767
 768         return 0;
 769 }
 770
 771 /**
 772  * nhi_mailbox_mode() - Return current firmware operation mode
 773  * @nhi: Pointer to the NHI structure
 774  *
 775  * The function reads current firmware operation mode using NHI mailbox
 776  * registers and returns it to the caller.
 777  */
 778 enum nhi_fw_mode nhi_mailbox_mode(struct tb_nhi *nhi)
 779 {
 780         u32 val;
 781
 782         val = ioread32(nhi->iobase + REG_OUTMAIL_CMD);
 783         val &= REG_OUTMAIL_CMD_OPMODE_MASK;
 784         val >>= REG_OUTMAIL_CMD_OPMODE_SHIFT;
 785
 786         return (enum nhi_fw_mode)val;
 787 }
 788
 789 static void nhi_interrupt_work(struct work_struct *work)
 790 {
 791         struct tb_nhi *nhi = container_of(work, typeof(*nhi), interrupt_work);
 792         int value = 0; /* Suppress uninitialized usage warning. */
 793         int bit;
 794         int hop = -1;
 795         int type = 0; /* current interrupt type 0: TX, 1: RX, 2: RX overflow */
 796         struct tb_ring *ring;
 797
 798         spin_lock_irq(&nhi->lock);
 799
 800         /*
 801          * Starting at REG_RING_NOTIFY_BASE there are three status bitfields
 802          * (TX, RX, RX overflow). We iterate over the bits and read a new
 803          * dwords as required. The registers are cleared on read.
 804          */
 805         for (bit = 0; bit < 3 * nhi->hop_count; bit++) {
 806                 if (bit % 32 == 0)
 807                         value = ioread32(nhi->iobase
 808                                          + REG_RING_NOTIFY_BASE
 809                                          + 4 * (bit / 32));
 810                 if (++hop == nhi->hop_count) {
 811                         hop = 0;
 812                         type++;
 813                 }
 814                 if ((value & (1 << (bit % 32))) == 0)
 815                         continue;
 816                 if (type == 2) {
 817                         dev_warn(&nhi->pdev->dev,
 818                                  "RX overflow for ring %d\n",
 819                                  hop);
 820                         continue;
 821                 }
 822                 if (type == 0)
 823                         ring = nhi->tx_rings[hop];
 824                 else
 825                         ring = nhi->rx_rings[hop];
 826                 if (ring == NULL) {
 827                         dev_warn(&nhi->pdev->dev,
 828                                  "got interrupt for inactive %s ring %d\n",
 829                                  type ? "RX" : "TX",
 830                                  hop);
 831                         continue;
 832                 }
 833
 834                 spin_lock(&ring->lock);
 835                 __ring_interrupt(ring);
 836                 spin_unlock(&ring->lock);
 837         }
 838         spin_unlock_irq(&nhi->lock);
 839 }
 840
 841 static irqreturn_t nhi_msi(int irq, void *data)
 842 {
 843         struct tb_nhi *nhi = data;
 844         schedule_work(&nhi->interrupt_work);
 845         return IRQ_HANDLED;
 846 }
 847
 848 static int nhi_suspend_noirq(struct device *dev)
 849 {
 850         struct pci_dev *pdev = to_pci_dev(dev);
 851         struct tb *tb = pci_get_drvdata(pdev);
 852
 853         return tb_domain_suspend_noirq(tb);
 854 }
 855
 856 static void nhi_enable_int_throttling(struct tb_nhi *nhi)
 857 {
 858         /* Throttling is specified in 256ns increments */
 859         u32 throttle = DIV_ROUND_UP(128 * NSEC_PER_USEC, 256);
 860         unsigned int i;
 861
 862         /*
 863          * Configure interrupt throttling for all vectors even if we
 864          * only use few.
 865          */
 866         for (i = 0; i < MSIX_MAX_VECS; i++) {
 867                 u32 reg = REG_INT_THROTTLING_RATE + i * 4;
 868                 iowrite32(throttle, nhi->iobase + reg);
 869         }
 870 }
 871
 872 static int nhi_resume_noirq(struct device *dev)
 873 {
 874         struct pci_dev *pdev = to_pci_dev(dev);
 875         struct tb *tb = pci_get_drvdata(pdev);
 876
 877         /*
 878          * Check that the device is still there. It may be that the user
 879          * unplugged last device which causes the host controller to go
 880          * away on PCs.
 881          */
 882         if (!pci_device_is_present(pdev))
 883                 tb->nhi->going_away = true;
 884         else
 885                 nhi_enable_int_throttling(tb->nhi);
 886
 887         return tb_domain_resume_noirq(tb);
 888 }
 889
 890 static int nhi_suspend(struct device *dev)
 891 {
 892         struct pci_dev *pdev = to_pci_dev(dev);
 893         struct tb *tb = pci_get_drvdata(pdev);
 894
 895         return tb_domain_suspend(tb);
 896 }
 897
 898 static void nhi_complete(struct device *dev)
 899 {
 900         struct pci_dev *pdev = to_pci_dev(dev);
 901         struct tb *tb = pci_get_drvdata(pdev);
 902
 903         /*
 904          * If we were runtime suspended when system suspend started,
 905          * schedule runtime resume now. It should bring the domain back
 906          * to functional state.
 907          */
 908         if (pm_runtime_suspended(&pdev->dev))
 909                 pm_runtime_resume(&pdev->dev);
 910         else
 911                 tb_domain_complete(tb);
 912 }
 913
 914 static int nhi_runtime_suspend(struct device *dev)
 915 {
 916         struct pci_dev *pdev = to_pci_dev(dev);
 917         struct tb *tb = pci_get_drvdata(pdev);
 918
 919         return tb_domain_runtime_suspend(tb);
 920 }
 921
 922 static int nhi_runtime_resume(struct device *dev)
 923 {
 924         struct pci_dev *pdev = to_pci_dev(dev);
 925         struct tb *tb = pci_get_drvdata(pdev);
 926
 927         nhi_enable_int_throttling(tb->nhi);
 928         return tb_domain_runtime_resume(tb);
 929 }
 930
 931 static void nhi_shutdown(struct tb_nhi *nhi)
 932 {
 933         int i;
 934
 935         dev_dbg(&nhi->pdev->dev, "shutdown\n");
 936
 937         for (i = 0; i < nhi->hop_count; i++) {
 938                 if (nhi->tx_rings[i])
 939                         dev_WARN(&nhi->pdev->dev,
 940                                  "TX ring %d is still active\n", i);
 941                 if (nhi->rx_rings[i])
 942                         dev_WARN(&nhi->pdev->dev,
 943                                  "RX ring %d is still active\n", i);
 944         }
 945         nhi_disable_interrupts(nhi);
 946         /*
 947          * We have to release the irq before calling flush_work. Otherwise an
 948          * already executing IRQ handler could call schedule_work again.
 949          */
 950         if (!nhi->pdev->msix_enabled) {
 951                 devm_free_irq(&nhi->pdev->dev, nhi->pdev->irq, nhi);
 952                 flush_work(&nhi->interrupt_work);
 953         }
 954         ida_destroy(&nhi->msix_ida);
 955 }
 956
 957 static int nhi_init_msi(struct tb_nhi *nhi)
 958 {
 959         struct pci_dev *pdev = nhi->pdev;
 960         int res, irq, nvec;
 961
 962         /* In case someone left them on. */
 963         nhi_disable_interrupts(nhi);
 964
 965         nhi_enable_int_throttling(nhi);
 966
 967         ida_init(&nhi->msix_ida);
 968
 969         /*
 970          * The NHI has 16 MSI-X vectors or a single MSI. We first try to
 971          * get all MSI-X vectors and if we succeed, each ring will have
 972          * one MSI-X. If for some reason that does not work out, we
 973          * fallback to a single MSI.
 974          */
 975         nvec = pci_alloc_irq_vectors(pdev, MSIX_MIN_VECS, MSIX_MAX_VECS,
 976                                      PCI_IRQ_MSIX);
 977         if (nvec < 0) {
 978                 nvec = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSI);
 979                 if (nvec < 0)
 980                         return nvec;
 981
 982                 INIT_WORK(&nhi->interrupt_work, nhi_interrupt_work);
 983
 984                 irq = pci_irq_vector(nhi->pdev, 0);
 985                 if (irq < 0)
 986                         return irq;
 987
 988                 res = devm_request_irq(&pdev->dev, irq, nhi_msi,
 989                                        IRQF_NO_SUSPEND, "thunderbolt", nhi);
 990                 if (res) {
 991                         dev_err(&pdev->dev, "request_irq failed, aborting\n");
 992                         return res;
 993                 }
 994         }
 995
 996         return 0;
 997 }
 998
 999 static int nhi_probe(struct pci_dev *pdev, const struct pci_device_id *id)
1000 {
1001         struct tb_nhi *nhi;
1002         struct tb *tb;
1003         int res;
1004
1005         res = pcim_enable_device(pdev);
1006         if (res) {
1007                 dev_err(&pdev->dev, "cannot enable PCI device, aborting\n");
1008                 return res;
1009         }
1010
1011         res = pcim_iomap_regions(pdev, 1 << 0, "thunderbolt");
1012         if (res) {
1013                 dev_err(&pdev->dev, "cannot obtain PCI resources, aborting\n");
1014                 return res;
1015         }
1016
1017         nhi = devm_kzalloc(&pdev->dev, sizeof(*nhi), GFP_KERNEL);
1018         if (!nhi)
1019                 return -ENOMEM;
1020
1021         nhi->pdev = pdev;
1022         /* cannot fail - table is allocated bin pcim_iomap_regions */
1023         nhi->iobase = pcim_iomap_table(pdev)[0];
1024         nhi->hop_count = ioread32(nhi->iobase + REG_HOP_COUNT) & 0x3ff;
1025         if (nhi->hop_count != 12 && nhi->hop_count != 32)
1026                 dev_warn(&pdev->dev, "unexpected hop count: %d\n",
1027                          nhi->hop_count);
1028
1029         nhi->tx_rings = devm_kcalloc(&pdev->dev, nhi->hop_count,
1030                                      sizeof(*nhi->tx_rings), GFP_KERNEL);
1031         nhi->rx_rings = devm_kcalloc(&pdev->dev, nhi->hop_count,
1032                                      sizeof(*nhi->rx_rings), GFP_KERNEL);
1033         if (!nhi->tx_rings || !nhi->rx_rings)
1034                 return -ENOMEM;
1035
1036         res = nhi_init_msi(nhi);
1037         if (res) {
1038                 dev_err(&pdev->dev, "cannot enable MSI, aborting\n");
1039                 return res;
1040         }
1041
1042         spin_lock_init(&nhi->lock);
1043
1044         res = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
1045         if (res)
1046                 res = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
1047         if (res) {
1048                 dev_err(&pdev->dev, "failed to set DMA mask\n");
1049                 return res;
1050         }
1051
1052         pci_set_master(pdev);
1053
1054         tb = icm_probe(nhi);
1055         if (!tb)
1056                 tb = tb_probe(nhi);
1057         if (!tb) {
1058                 dev_err(&nhi->pdev->dev,
1059                         "failed to determine connection manager, aborting\n");
1060                 return -ENODEV;
1061         }
1062
1063         dev_dbg(&nhi->pdev->dev, "NHI initialized, starting thunderbolt\n");
1064
1065         res = tb_domain_add(tb);
1066         if (res) {
1067                 /*
1068                  * At this point the RX/TX rings might already have been
1069                  * activated. Do a proper shutdown.
1070                  */
1071                 tb_domain_put(tb);
1072                 nhi_shutdown(nhi);
1073                 return res;
1074         }
1075         pci_set_drvdata(pdev, tb);
1076
1077         pm_runtime_allow(&pdev->dev);
1078         pm_runtime_set_autosuspend_delay(&pdev->dev, TB_AUTOSUSPEND_DELAY);
1079         pm_runtime_use_autosuspend(&pdev->dev);
1080         pm_runtime_put_autosuspend(&pdev->dev);
1081
1082         return 0;
1083 }
1084
1085 static void nhi_remove(struct pci_dev *pdev)
1086 {
1087         struct tb *tb = pci_get_drvdata(pdev);
1088         struct tb_nhi *nhi = tb->nhi;
1089
1090         pm_runtime_get_sync(&pdev->dev);
1091         pm_runtime_dont_use_autosuspend(&pdev->dev);
1092         pm_runtime_forbid(&pdev->dev);
1093
1094         tb_domain_remove(tb);
1095         nhi_shutdown(nhi);
1096 }
1097
1098 /*
1099  * The tunneled pci bridges are siblings of us. Use resume_noirq to reenable
1100  * the tunnels asap. A corresponding pci quirk blocks the downstream bridges
1101  * resume_noirq until we are done.
1102  */
1103 static const struct dev_pm_ops nhi_pm_ops = {
1104         .suspend_noirq = nhi_suspend_noirq,
1105         .resume_noirq = nhi_resume_noirq,
1106         .freeze_noirq = nhi_suspend_noirq, /*
1107                                             * we just disable hotplug, the
1108                                             * pci-tunnels stay alive.
1109                                             */
1110         .thaw_noirq = nhi_resume_noirq,
1111         .restore_noirq = nhi_resume_noirq,
1112         .suspend = nhi_suspend,
1113         .freeze = nhi_suspend,
1114         .poweroff = nhi_suspend,
1115         .complete = nhi_complete,
1116         .runtime_suspend = nhi_runtime_suspend,
1117         .runtime_resume = nhi_runtime_resume,
1118 };
1119
1120 static struct pci_device_id nhi_ids[] = {
1121         /*
1122          * We have to specify class, the TB bridges use the same device and
1123          * vendor (sub)id on gen 1 and gen 2 controllers.
1124          */
1125         {
1126                 .class = PCI_CLASS_SYSTEM_OTHER << 8, .class_mask = ~0,
1127                 .vendor = PCI_VENDOR_ID_INTEL,
1128                 .device = PCI_DEVICE_ID_INTEL_LIGHT_RIDGE,
1129                 .subvendor = 0x2222, .subdevice = 0x1111,
1130         },
1131         {
1132                 .class = PCI_CLASS_SYSTEM_OTHER << 8, .class_mask = ~0,
1133                 .vendor = PCI_VENDOR_ID_INTEL,
1134                 .device = PCI_DEVICE_ID_INTEL_CACTUS_RIDGE_4C,
1135                 .subvendor = 0x2222, .subdevice = 0x1111,
1136         },
1137         {
1138                 .class = PCI_CLASS_SYSTEM_OTHER << 8, .class_mask = ~0,
1139                 .vendor = PCI_VENDOR_ID_INTEL,
1140                 .device = PCI_DEVICE_ID_INTEL_FALCON_RIDGE_2C_NHI,
1141                 .subvendor = PCI_ANY_ID, .subdevice = PCI_ANY_ID,
1142         },
1143         {
1144                 .class = PCI_CLASS_SYSTEM_OTHER << 8, .class_mask = ~0,
1145                 .vendor = PCI_VENDOR_ID_INTEL,
1146                 .device = PCI_DEVICE_ID_INTEL_FALCON_RIDGE_4C_NHI,
1147                 .subvendor = PCI_ANY_ID, .subdevice = PCI_ANY_ID,
1148         },
1149
1150         /* Thunderbolt 3 */
1151         { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_2C_NHI) },
1152         { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_4C_NHI) },
1153         { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_USBONLY_NHI) },
1154         { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_LP_NHI) },
1155         { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_LP_USBONLY_NHI) },
1156         { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_C_2C_NHI) },
1157         { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_C_4C_NHI) },
1158         { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_C_USBONLY_NHI) },
1159         { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_TITAN_RIDGE_2C_NHI) },
1160         { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_TITAN_RIDGE_4C_NHI) },
1161
1162         { 0,}
1163 };
1164
1165 MODULE_DEVICE_TABLE(pci, nhi_ids);
1166 MODULE_LICENSE("GPL");
1167
1168 static struct pci_driver nhi_driver = {
1169         .name = "thunderbolt",
1170         .id_table = nhi_ids,
1171         .probe = nhi_probe,
1172         .remove = nhi_remove,
1173         .driver.pm = &nhi_pm_ops,
1174 };
1175
1176 static int __init nhi_init(void)
1177 {
1178         int ret;
1179
1180         ret = tb_domain_init();
1181         if (ret)
1182                 return ret;
1183         ret = pci_register_driver(&nhi_driver);
1184         if (ret)
1185                 tb_domain_exit();
1186         return ret;
1187 }
1188
1189 static void __exit nhi_unload(void)
1190 {
1191         pci_unregister_driver(&nhi_driver);
1192         tb_domain_exit();
1193 }
1194
1195 rootfs_initcall(nhi_init);
1196 module_exit(nhi_unload);