drivers/misc/mic/scif/scif_rma.c

   1 /*
   2  * Intel MIC Platform Software Stack (MPSS)
   3  *
   4  * Copyright(c) 2015 Intel Corporation.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License, version 2, as
   8  * published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  13  * General Public License for more details.
  14  *
  15  * Intel SCIF driver.
  16  *
  17  */
  18 #include <linux/dma_remapping.h>
  19 #include <linux/pagemap.h>
  20 #include <linux/sched/mm.h>
  21 #include <linux/sched/signal.h>
  22
  23 #include "scif_main.h"
  24 #include "scif_map.h"
  25
  26 /* Used to skip ulimit checks for registrations with SCIF_MAP_KERNEL flag */
  27 #define SCIF_MAP_ULIMIT 0x40
  28
  29 bool scif_ulimit_check = 1;
  30
  31 /**
  32  * scif_rma_ep_init:
  33  * @ep: end point
  34  *
  35  * Initialize RMA per EP data structures.
  36  */
  37 void scif_rma_ep_init(struct scif_endpt *ep)
  38 {
  39         struct scif_endpt_rma_info *rma = &ep->rma_info;
  40
  41         mutex_init(&rma->rma_lock);
  42         init_iova_domain(&rma->iovad, PAGE_SIZE, SCIF_IOVA_START_PFN,
  43                          SCIF_DMA_64BIT_PFN);
  44         spin_lock_init(&rma->tc_lock);
  45         mutex_init(&rma->mmn_lock);
  46         INIT_LIST_HEAD(&rma->reg_list);
  47         INIT_LIST_HEAD(&rma->remote_reg_list);
  48         atomic_set(&rma->tw_refcount, 0);
  49         atomic_set(&rma->tcw_refcount, 0);
  50         atomic_set(&rma->tcw_total_pages, 0);
  51         atomic_set(&rma->fence_refcount, 0);
  52
  53         rma->async_list_del = 0;
  54         rma->dma_chan = NULL;
  55         INIT_LIST_HEAD(&rma->mmn_list);
  56         INIT_LIST_HEAD(&rma->vma_list);
  57         init_waitqueue_head(&rma->markwq);
  58 }
  59
  60 /**
  61  * scif_rma_ep_can_uninit:
  62  * @ep: end point
  63  *
  64  * Returns 1 if an endpoint can be uninitialized and 0 otherwise.
  65  */
  66 int scif_rma_ep_can_uninit(struct scif_endpt *ep)
  67 {
  68         int ret = 0;
  69
  70         mutex_lock(&ep->rma_info.rma_lock);
  71         /* Destroy RMA Info only if both lists are empty */
  72         if (list_empty(&ep->rma_info.reg_list) &&
  73             list_empty(&ep->rma_info.remote_reg_list) &&
  74             list_empty(&ep->rma_info.mmn_list) &&
  75             !atomic_read(&ep->rma_info.tw_refcount) &&
  76             !atomic_read(&ep->rma_info.tcw_refcount) &&
  77             !atomic_read(&ep->rma_info.fence_refcount))
  78                 ret = 1;
  79         mutex_unlock(&ep->rma_info.rma_lock);
  80         return ret;
  81 }
  82
  83 /**
  84  * scif_create_pinned_pages:
  85  * @nr_pages: number of pages in window
  86  * @prot: read/write protection
  87  *
  88  * Allocate and prepare a set of pinned pages.
  89  */
  90 static struct scif_pinned_pages *
  91 scif_create_pinned_pages(int nr_pages, int prot)
  92 {
  93         struct scif_pinned_pages *pin;
  94
  95         might_sleep();
  96         pin = scif_zalloc(sizeof(*pin));
  97         if (!pin)
  98                 goto error;
  99
 100         pin->pages = scif_zalloc(nr_pages * sizeof(*pin->pages));
 101         if (!pin->pages)
 102                 goto error_free_pinned_pages;
 103
 104         pin->prot = prot;
 105         pin->magic = SCIFEP_MAGIC;
 106         return pin;
 107
 108 error_free_pinned_pages:
 109         scif_free(pin, sizeof(*pin));
 110 error:
 111         return NULL;
 112 }
 113
 114 /**
 115  * scif_destroy_pinned_pages:
 116  * @pin: A set of pinned pages.
 117  *
 118  * Deallocate resources for pinned pages.
 119  */
 120 static int scif_destroy_pinned_pages(struct scif_pinned_pages *pin)
 121 {
 122         int j;
 123         int writeable = pin->prot & SCIF_PROT_WRITE;
 124         int kernel = SCIF_MAP_KERNEL & pin->map_flags;
 125
 126         for (j = 0; j < pin->nr_pages; j++) {
 127                 if (pin->pages[j] && !kernel) {
 128                         if (writeable)
 129                                 SetPageDirty(pin->pages[j]);
 130                         put_page(pin->pages[j]);
 131                 }
 132         }
 133
 134         scif_free(pin->pages,
 135                   pin->nr_pages * sizeof(*pin->pages));
 136         scif_free(pin, sizeof(*pin));
 137         return 0;
 138 }
 139
 140 /*
 141  * scif_create_window:
 142  * @ep: end point
 143  * @nr_pages: number of pages
 144  * @offset: registration offset
 145  * @temp: true if a temporary window is being created
 146  *
 147  * Allocate and prepare a self registration window.
 148  */
 149 struct scif_window *scif_create_window(struct scif_endpt *ep, int nr_pages,
 150                                        s64 offset, bool temp)
 151 {
 152         struct scif_window *window;
 153
 154         might_sleep();
 155         window = scif_zalloc(sizeof(*window));
 156         if (!window)
 157                 goto error;
 158
 159         window->dma_addr = scif_zalloc(nr_pages * sizeof(*window->dma_addr));
 160         if (!window->dma_addr)
 161                 goto error_free_window;
 162
 163         window->num_pages = scif_zalloc(nr_pages * sizeof(*window->num_pages));
 164         if (!window->num_pages)
 165                 goto error_free_window;
 166
 167         window->offset = offset;
 168         window->ep = (u64)ep;
 169         window->magic = SCIFEP_MAGIC;
 170         window->reg_state = OP_IDLE;
 171         init_waitqueue_head(&window->regwq);
 172         window->unreg_state = OP_IDLE;
 173         init_waitqueue_head(&window->unregwq);
 174         INIT_LIST_HEAD(&window->list);
 175         window->type = SCIF_WINDOW_SELF;
 176         window->temp = temp;
 177         return window;
 178
 179 error_free_window:
 180         scif_free(window->dma_addr,
 181                   nr_pages * sizeof(*window->dma_addr));
 182         scif_free(window, sizeof(*window));
 183 error:
 184         return NULL;
 185 }
 186
 187 /**
 188  * scif_destroy_incomplete_window:
 189  * @ep: end point
 190  * @window: registration window
 191  *
 192  * Deallocate resources for self window.
 193  */
 194 static void scif_destroy_incomplete_window(struct scif_endpt *ep,
 195                                            struct scif_window *window)
 196 {
 197         int err;
 198         int nr_pages = window->nr_pages;
 199         struct scif_allocmsg *alloc = &window->alloc_handle;
 200         struct scifmsg msg;
 201
 202 retry:
 203         /* Wait for a SCIF_ALLOC_GNT/REJ message */
 204         err = wait_event_timeout(alloc->allocwq,
 205                                  alloc->state != OP_IN_PROGRESS,
 206                                  SCIF_NODE_ALIVE_TIMEOUT);
 207         if (!err && scifdev_alive(ep))
 208                 goto retry;
 209
 210         mutex_lock(&ep->rma_info.rma_lock);
 211         if (alloc->state == OP_COMPLETED) {
 212                 msg.uop = SCIF_FREE_VIRT;
 213                 msg.src = ep->port;
 214                 msg.payload[0] = ep->remote_ep;
 215                 msg.payload[1] = window->alloc_handle.vaddr;
 216                 msg.payload[2] = (u64)window;
 217                 msg.payload[3] = SCIF_REGISTER;
 218                 _scif_nodeqp_send(ep->remote_dev, &msg);
 219         }
 220         mutex_unlock(&ep->rma_info.rma_lock);
 221
 222         scif_free_window_offset(ep, window, window->offset);
 223         scif_free(window->dma_addr, nr_pages * sizeof(*window->dma_addr));
 224         scif_free(window->num_pages, nr_pages * sizeof(*window->num_pages));
 225         scif_free(window, sizeof(*window));
 226 }
 227
 228 /**
 229  * scif_unmap_window:
 230  * @remote_dev: SCIF remote device
 231  * @window: registration window
 232  *
 233  * Delete any DMA mappings created for a registered self window
 234  */
 235 void scif_unmap_window(struct scif_dev *remote_dev, struct scif_window *window)
 236 {
 237         int j;
 238
 239         if (scif_is_iommu_enabled() && !scifdev_self(remote_dev)) {
 240                 if (window->st) {
 241                         dma_unmap_sg(&remote_dev->sdev->dev,
 242                                      window->st->sgl, window->st->nents,
 243                                      DMA_BIDIRECTIONAL);
 244                         sg_free_table(window->st);
 245                         kfree(window->st);
 246                         window->st = NULL;
 247                 }
 248         } else {
 249                 for (j = 0; j < window->nr_contig_chunks; j++) {
 250                         if (window->dma_addr[j]) {
 251                                 scif_unmap_single(window->dma_addr[j],
 252                                                   remote_dev,
 253                                                   window->num_pages[j] <<
 254                                                   PAGE_SHIFT);
 255                                 window->dma_addr[j] = 0x0;
 256                         }
 257                 }
 258         }
 259 }
 260
 261 static inline struct mm_struct *__scif_acquire_mm(void)
 262 {
 263         if (scif_ulimit_check)
 264                 return get_task_mm(current);
 265         return NULL;
 266 }
 267
 268 static inline void __scif_release_mm(struct mm_struct *mm)
 269 {
 270         if (mm)
 271                 mmput(mm);
 272 }
 273
 274 static inline int
 275 __scif_dec_pinned_vm_lock(struct mm_struct *mm,
 276                           int nr_pages, bool try_lock)
 277 {
 278         if (!mm || !nr_pages || !scif_ulimit_check)
 279                 return 0;
 280         if (try_lock) {
 281                 if (!down_write_trylock(&mm->mmap_sem)) {
 282                         dev_err(scif_info.mdev.this_device,
 283                                 "%s %d err\n", __func__, __LINE__);
 284                         return -1;
 285                 }
 286         } else {
 287                 down_write(&mm->mmap_sem);
 288         }
 289         mm->pinned_vm -= nr_pages;
 290         up_write(&mm->mmap_sem);
 291         return 0;
 292 }
 293
 294 static inline int __scif_check_inc_pinned_vm(struct mm_struct *mm,
 295                                              int nr_pages)
 296 {
 297         unsigned long locked, lock_limit;
 298
 299         if (!mm || !nr_pages || !scif_ulimit_check)
 300                 return 0;
 301
 302         locked = nr_pages;
 303         locked += mm->pinned_vm;
 304         lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
 305         if ((locked > lock_limit) && !capable(CAP_IPC_LOCK)) {
 306                 dev_err(scif_info.mdev.this_device,
 307                         "locked(%lu) > lock_limit(%lu)\n",
 308                         locked, lock_limit);
 309                 return -ENOMEM;
 310         }
 311         mm->pinned_vm = locked;
 312         return 0;
 313 }
 314
 315 /**
 316  * scif_destroy_window:
 317  * @ep: end point
 318  * @window: registration window
 319  *
 320  * Deallocate resources for self window.
 321  */
 322 int scif_destroy_window(struct scif_endpt *ep, struct scif_window *window)
 323 {
 324         int j;
 325         struct scif_pinned_pages *pinned_pages = window->pinned_pages;
 326         int nr_pages = window->nr_pages;
 327
 328         might_sleep();
 329         if (!window->temp && window->mm) {
 330                 __scif_dec_pinned_vm_lock(window->mm, window->nr_pages, 0);
 331                 __scif_release_mm(window->mm);
 332                 window->mm = NULL;
 333         }
 334
 335         scif_free_window_offset(ep, window, window->offset);
 336         scif_unmap_window(ep->remote_dev, window);
 337         /*
 338          * Decrement references for this set of pinned pages from
 339          * this window.
 340          */
 341         j = atomic_sub_return(1, &pinned_pages->ref_count);
 342         if (j < 0)
 343                 dev_err(scif_info.mdev.this_device,
 344                         "%s %d incorrect ref count %d\n",
 345                         __func__, __LINE__, j);
 346         /*
 347          * If the ref count for pinned_pages is zero then someone
 348          * has already called scif_unpin_pages() for it and we should
 349          * destroy the page cache.
 350          */
 351         if (!j)
 352                 scif_destroy_pinned_pages(window->pinned_pages);
 353         scif_free(window->dma_addr, nr_pages * sizeof(*window->dma_addr));
 354         scif_free(window->num_pages, nr_pages * sizeof(*window->num_pages));
 355         window->magic = 0;
 356         scif_free(window, sizeof(*window));
 357         return 0;
 358 }
 359
 360 /**
 361  * scif_create_remote_lookup:
 362  * @remote_dev: SCIF remote device
 363  * @window: remote window
 364  *
 365  * Allocate and prepare lookup entries for the remote
 366  * end to copy over the physical addresses.
 367  * Returns 0 on success and appropriate errno on failure.
 368  */
 369 static int scif_create_remote_lookup(struct scif_dev *remote_dev,
 370                                      struct scif_window *window)
 371 {
 372         int i, j, err = 0;
 373         int nr_pages = window->nr_pages;
 374         bool vmalloc_dma_phys, vmalloc_num_pages;
 375
 376         might_sleep();
 377         /* Map window */
 378         err = scif_map_single(&window->mapped_offset,
 379                               window, remote_dev, sizeof(*window));
 380         if (err)
 381                 goto error_window;
 382
 383         /* Compute the number of lookup entries. 21 == 2MB Shift */
 384         window->nr_lookup = ALIGN(nr_pages * PAGE_SIZE,
 385                                         ((2) * 1024 * 1024)) >> 21;
 386
 387         window->dma_addr_lookup.lookup =
 388                 scif_alloc_coherent(&window->dma_addr_lookup.offset,
 389                                     remote_dev, window->nr_lookup *
 390                                     sizeof(*window->dma_addr_lookup.lookup),
 391                                     GFP_KERNEL | __GFP_ZERO);
 392         if (!window->dma_addr_lookup.lookup) {
 393                 err = -ENOMEM;
 394                 goto error_window;
 395         }
 396
 397         window->num_pages_lookup.lookup =
 398                 scif_alloc_coherent(&window->num_pages_lookup.offset,
 399                                     remote_dev, window->nr_lookup *
 400                                     sizeof(*window->num_pages_lookup.lookup),
 401                                     GFP_KERNEL | __GFP_ZERO);
 402         if (!window->num_pages_lookup.lookup) {
 403                 err = -ENOMEM;
 404                 goto error_window;
 405         }
 406
 407         vmalloc_dma_phys = is_vmalloc_addr(&window->dma_addr[0]);
 408         vmalloc_num_pages = is_vmalloc_addr(&window->num_pages[0]);
 409
 410         /* Now map each of the pages containing physical addresses */
 411         for (i = 0, j = 0; i < nr_pages; i += SCIF_NR_ADDR_IN_PAGE, j++) {
 412                 err = scif_map_page(&window->dma_addr_lookup.lookup[j],
 413                                     vmalloc_dma_phys ?
 414                                     vmalloc_to_page(&window->dma_addr[i]) :
 415                                     virt_to_page(&window->dma_addr[i]),
 416                                     remote_dev);
 417                 if (err)
 418                         goto error_window;
 419                 err = scif_map_page(&window->num_pages_lookup.lookup[j],
 420                                     vmalloc_num_pages ?
 421                                     vmalloc_to_page(&window->num_pages[i]) :
 422                                     virt_to_page(&window->num_pages[i]),
 423                                     remote_dev);
 424                 if (err)
 425                         goto error_window;
 426         }
 427         return 0;
 428 error_window:
 429         return err;
 430 }
 431
 432 /**
 433  * scif_destroy_remote_lookup:
 434  * @remote_dev: SCIF remote device
 435  * @window: remote window
 436  *
 437  * Destroy lookup entries used for the remote
 438  * end to copy over the physical addresses.
 439  */
 440 static void scif_destroy_remote_lookup(struct scif_dev *remote_dev,
 441                                        struct scif_window *window)
 442 {
 443         int i, j;
 444
 445         if (window->nr_lookup) {
 446                 struct scif_rma_lookup *lup = &window->dma_addr_lookup;
 447                 struct scif_rma_lookup *npup = &window->num_pages_lookup;
 448
 449                 for (i = 0, j = 0; i < window->nr_pages;
 450                         i += SCIF_NR_ADDR_IN_PAGE, j++) {
 451                         if (lup->lookup && lup->lookup[j])
 452                                 scif_unmap_single(lup->lookup[j],
 453                                                   remote_dev,
 454                                                   PAGE_SIZE);
 455                         if (npup->lookup && npup->lookup[j])
 456                                 scif_unmap_single(npup->lookup[j],
 457                                                   remote_dev,
 458                                                   PAGE_SIZE);
 459                 }
 460                 if (lup->lookup)
 461                         scif_free_coherent(lup->lookup, lup->offset,
 462                                            remote_dev, window->nr_lookup *
 463                                            sizeof(*lup->lookup));
 464                 if (npup->lookup)
 465                         scif_free_coherent(npup->lookup, npup->offset,
 466                                            remote_dev, window->nr_lookup *
 467                                            sizeof(*npup->lookup));
 468                 if (window->mapped_offset)
 469                         scif_unmap_single(window->mapped_offset,
 470                                           remote_dev, sizeof(*window));
 471                 window->nr_lookup = 0;
 472         }
 473 }
 474
 475 /**
 476  * scif_create_remote_window:
 477  * @ep: end point
 478  * @nr_pages: number of pages in window
 479  *
 480  * Allocate and prepare a remote registration window.
 481  */
 482 static struct scif_window *
 483 scif_create_remote_window(struct scif_dev *scifdev, int nr_pages)
 484 {
 485         struct scif_window *window;
 486
 487         might_sleep();
 488         window = scif_zalloc(sizeof(*window));
 489         if (!window)
 490                 goto error_ret;
 491
 492         window->magic = SCIFEP_MAGIC;
 493         window->nr_pages = nr_pages;
 494
 495         window->dma_addr = scif_zalloc(nr_pages * sizeof(*window->dma_addr));
 496         if (!window->dma_addr)
 497                 goto error_window;
 498
 499         window->num_pages = scif_zalloc(nr_pages *
 500                                         sizeof(*window->num_pages));
 501         if (!window->num_pages)
 502                 goto error_window;
 503
 504         if (scif_create_remote_lookup(scifdev, window))
 505                 goto error_window;
 506
 507         window->type = SCIF_WINDOW_PEER;
 508         window->unreg_state = OP_IDLE;
 509         INIT_LIST_HEAD(&window->list);
 510         return window;
 511 error_window:
 512         scif_destroy_remote_window(window);
 513 error_ret:
 514         return NULL;
 515 }
 516
 517 /**
 518  * scif_destroy_remote_window:
 519  * @ep: end point
 520  * @window: remote registration window
 521  *
 522  * Deallocate resources for remote window.
 523  */
 524 void
 525 scif_destroy_remote_window(struct scif_window *window)
 526 {
 527         scif_free(window->dma_addr, window->nr_pages *
 528                   sizeof(*window->dma_addr));
 529         scif_free(window->num_pages, window->nr_pages *
 530                   sizeof(*window->num_pages));
 531         window->magic = 0;
 532         scif_free(window, sizeof(*window));
 533 }
 534
 535 /**
 536  * scif_iommu_map: create DMA mappings if the IOMMU is enabled
 537  * @remote_dev: SCIF remote device
 538  * @window: remote registration window
 539  *
 540  * Map the physical pages using dma_map_sg(..) and then detect the number
 541  * of contiguous DMA mappings allocated
 542  */
 543 static int scif_iommu_map(struct scif_dev *remote_dev,
 544                           struct scif_window *window)
 545 {
 546         struct scatterlist *sg;
 547         int i, err;
 548         scif_pinned_pages_t pin = window->pinned_pages;
 549
 550         window->st = kzalloc(sizeof(*window->st), GFP_KERNEL);
 551         if (!window->st)
 552                 return -ENOMEM;
 553
 554         err = sg_alloc_table(window->st, window->nr_pages, GFP_KERNEL);
 555         if (err)
 556                 return err;
 557
 558         for_each_sg(window->st->sgl, sg, window->st->nents, i)
 559                 sg_set_page(sg, pin->pages[i], PAGE_SIZE, 0x0);
 560
 561         err = dma_map_sg(&remote_dev->sdev->dev, window->st->sgl,
 562                          window->st->nents, DMA_BIDIRECTIONAL);
 563         if (!err)
 564                 return -ENOMEM;
 565         /* Detect contiguous ranges of DMA mappings */
 566         sg = window->st->sgl;
 567         for (i = 0; sg; i++) {
 568                 dma_addr_t last_da;
 569
 570                 window->dma_addr[i] = sg_dma_address(sg);
 571                 window->num_pages[i] = sg_dma_len(sg) >> PAGE_SHIFT;
 572                 last_da = sg_dma_address(sg) + sg_dma_len(sg);
 573                 while ((sg = sg_next(sg)) && sg_dma_address(sg) == last_da) {
 574                         window->num_pages[i] +=
 575                                 (sg_dma_len(sg) >> PAGE_SHIFT);
 576                         last_da = window->dma_addr[i] +
 577                                 sg_dma_len(sg);
 578                 }
 579                 window->nr_contig_chunks++;
 580         }
 581         return 0;
 582 }
 583
 584 /**
 585  * scif_map_window:
 586  * @remote_dev: SCIF remote device
 587  * @window: self registration window
 588  *
 589  * Map pages of a window into the aperture/PCI.
 590  * Also determine addresses required for DMA.
 591  */
 592 int
 593 scif_map_window(struct scif_dev *remote_dev, struct scif_window *window)
 594 {
 595         int i, j, k, err = 0, nr_contig_pages;
 596         scif_pinned_pages_t pin;
 597         phys_addr_t phys_prev, phys_curr;
 598
 599         might_sleep();
 600
 601         pin = window->pinned_pages;
 602
 603         if (intel_iommu_enabled && !scifdev_self(remote_dev))
 604                 return scif_iommu_map(remote_dev, window);
 605
 606         for (i = 0, j = 0; i < window->nr_pages; i += nr_contig_pages, j++) {
 607                 phys_prev = page_to_phys(pin->pages[i]);
 608                 nr_contig_pages = 1;
 609
 610                 /* Detect physically contiguous chunks */
 611                 for (k = i + 1; k < window->nr_pages; k++) {
 612                         phys_curr = page_to_phys(pin->pages[k]);
 613                         if (phys_curr != (phys_prev + PAGE_SIZE))
 614                                 break;
 615                         phys_prev = phys_curr;
 616                         nr_contig_pages++;
 617                 }
 618                 window->num_pages[j] = nr_contig_pages;
 619                 window->nr_contig_chunks++;
 620                 if (scif_is_mgmt_node()) {
 621                         /*
 622                          * Management node has to deal with SMPT on X100 and
 623                          * hence the DMA mapping is required
 624                          */
 625                         err = scif_map_single(&window->dma_addr[j],
 626                                               phys_to_virt(page_to_phys(
 627                                                            pin->pages[i])),
 628                                               remote_dev,
 629                                               nr_contig_pages << PAGE_SHIFT);
 630                         if (err)
 631                                 return err;
 632                 } else {
 633                         window->dma_addr[j] = page_to_phys(pin->pages[i]);
 634                 }
 635         }
 636         return err;
 637 }
 638
 639 /**
 640  * scif_send_scif_unregister:
 641  * @ep: end point
 642  * @window: self registration window
 643  *
 644  * Send a SCIF_UNREGISTER message.
 645  */
 646 static int scif_send_scif_unregister(struct scif_endpt *ep,
 647                                      struct scif_window *window)
 648 {
 649         struct scifmsg msg;
 650
 651         msg.uop = SCIF_UNREGISTER;
 652         msg.src = ep->port;
 653         msg.payload[0] = window->alloc_handle.vaddr;
 654         msg.payload[1] = (u64)window;
 655         return scif_nodeqp_send(ep->remote_dev, &msg);
 656 }
 657
 658 /**
 659  * scif_unregister_window:
 660  * @window: self registration window
 661  *
 662  * Send an unregistration request and wait for a response.
 663  */
 664 int scif_unregister_window(struct scif_window *window)
 665 {
 666         int err = 0;
 667         struct scif_endpt *ep = (struct scif_endpt *)window->ep;
 668         bool send_msg = false;
 669
 670         might_sleep();
 671         switch (window->unreg_state) {
 672         case OP_IDLE:
 673         {
 674                 window->unreg_state = OP_IN_PROGRESS;
 675                 send_msg = true;
 676                 /* fall through */
 677         }
 678         case OP_IN_PROGRESS:
 679         {
 680                 scif_get_window(window, 1);
 681                 mutex_unlock(&ep->rma_info.rma_lock);
 682                 if (send_msg) {
 683                         err = scif_send_scif_unregister(ep, window);
 684                         if (err) {
 685                                 window->unreg_state = OP_COMPLETED;
 686                                 goto done;
 687                         }
 688                 } else {
 689                         /* Return ENXIO since unregistration is in progress */
 690                         mutex_lock(&ep->rma_info.rma_lock);
 691                         return -ENXIO;
 692                 }
 693 retry:
 694                 /* Wait for a SCIF_UNREGISTER_(N)ACK message */
 695                 err = wait_event_timeout(window->unregwq,
 696                                          window->unreg_state != OP_IN_PROGRESS,
 697                                          SCIF_NODE_ALIVE_TIMEOUT);
 698                 if (!err && scifdev_alive(ep))
 699                         goto retry;
 700                 if (!err) {
 701                         err = -ENODEV;
 702                         window->unreg_state = OP_COMPLETED;
 703                         dev_err(scif_info.mdev.this_device,
 704                                 "%s %d err %d\n", __func__, __LINE__, err);
 705                 }
 706                 if (err > 0)
 707                         err = 0;
 708 done:
 709                 mutex_lock(&ep->rma_info.rma_lock);
 710                 scif_put_window(window, 1);
 711                 break;
 712         }
 713         case OP_FAILED:
 714         {
 715                 if (!scifdev_alive(ep)) {
 716                         err = -ENODEV;
 717                         window->unreg_state = OP_COMPLETED;
 718                 }
 719                 break;
 720         }
 721         case OP_COMPLETED:
 722                 break;
 723         default:
 724                 err = -ENODEV;
 725         }
 726
 727         if (window->unreg_state == OP_COMPLETED && window->ref_count)
 728                 scif_put_window(window, window->nr_pages);
 729
 730         if (!window->ref_count) {
 731                 atomic_inc(&ep->rma_info.tw_refcount);
 732                 list_del_init(&window->list);
 733                 scif_free_window_offset(ep, window, window->offset);
 734                 mutex_unlock(&ep->rma_info.rma_lock);
 735                 if ((!!(window->pinned_pages->map_flags & SCIF_MAP_KERNEL)) &&
 736                     scifdev_alive(ep)) {
 737                         scif_drain_dma_intr(ep->remote_dev->sdev,
 738                                             ep->rma_info.dma_chan);
 739                 } else {
 740                         if (!__scif_dec_pinned_vm_lock(window->mm,
 741                                                        window->nr_pages, 1)) {
 742                                 __scif_release_mm(window->mm);
 743                                 window->mm = NULL;
 744                         }
 745                 }
 746                 scif_queue_for_cleanup(window, &scif_info.rma);
 747                 mutex_lock(&ep->rma_info.rma_lock);
 748         }
 749         return err;
 750 }
 751
 752 /**
 753  * scif_send_alloc_request:
 754  * @ep: end point
 755  * @window: self registration window
 756  *
 757  * Send a remote window allocation request
 758  */
 759 static int scif_send_alloc_request(struct scif_endpt *ep,
 760                                    struct scif_window *window)
 761 {
 762         struct scifmsg msg;
 763         struct scif_allocmsg *alloc = &window->alloc_handle;
 764
 765         /* Set up the Alloc Handle */
 766         alloc->state = OP_IN_PROGRESS;
 767         init_waitqueue_head(&alloc->allocwq);
 768
 769         /* Send out an allocation request */
 770         msg.uop = SCIF_ALLOC_REQ;
 771         msg.payload[1] = window->nr_pages;
 772         msg.payload[2] = (u64)&window->alloc_handle;
 773         return _scif_nodeqp_send(ep->remote_dev, &msg);
 774 }
 775
 776 /**
 777  * scif_prep_remote_window:
 778  * @ep: end point
 779  * @window: self registration window
 780  *
 781  * Send a remote window allocation request, wait for an allocation response,
 782  * and prepares the remote window by copying over the page lists
 783  */
 784 static int scif_prep_remote_window(struct scif_endpt *ep,
 785                                    struct scif_window *window)
 786 {
 787         struct scifmsg msg;
 788         struct scif_window *remote_window;
 789         struct scif_allocmsg *alloc = &window->alloc_handle;
 790         dma_addr_t *dma_phys_lookup, *tmp, *num_pages_lookup, *tmp1;
 791         int i = 0, j = 0;
 792         int nr_contig_chunks, loop_nr_contig_chunks;
 793         int remaining_nr_contig_chunks, nr_lookup;
 794         int err, map_err;
 795
 796         map_err = scif_map_window(ep->remote_dev, window);
 797         if (map_err)
 798                 dev_err(&ep->remote_dev->sdev->dev,
 799                         "%s %d map_err %d\n", __func__, __LINE__, map_err);
 800         remaining_nr_contig_chunks = window->nr_contig_chunks;
 801         nr_contig_chunks = window->nr_contig_chunks;
 802 retry:
 803         /* Wait for a SCIF_ALLOC_GNT/REJ message */
 804         err = wait_event_timeout(alloc->allocwq,
 805                                  alloc->state != OP_IN_PROGRESS,
 806                                  SCIF_NODE_ALIVE_TIMEOUT);
 807         mutex_lock(&ep->rma_info.rma_lock);
 808         /* Synchronize with the thread waking up allocwq */
 809         mutex_unlock(&ep->rma_info.rma_lock);
 810         if (!err && scifdev_alive(ep))
 811                 goto retry;
 812
 813         if (!err)
 814                 err = -ENODEV;
 815
 816         if (err > 0)
 817                 err = 0;
 818         else
 819                 return err;
 820
 821         /* Bail out. The remote end rejected this request */
 822         if (alloc->state == OP_FAILED)
 823                 return -ENOMEM;
 824
 825         if (map_err) {
 826                 dev_err(&ep->remote_dev->sdev->dev,
 827                         "%s %d err %d\n", __func__, __LINE__, map_err);
 828                 msg.uop = SCIF_FREE_VIRT;
 829                 msg.src = ep->port;
 830                 msg.payload[0] = ep->remote_ep;
 831                 msg.payload[1] = window->alloc_handle.vaddr;
 832                 msg.payload[2] = (u64)window;
 833                 msg.payload[3] = SCIF_REGISTER;
 834                 spin_lock(&ep->lock);
 835                 if (ep->state == SCIFEP_CONNECTED)
 836                         err = _scif_nodeqp_send(ep->remote_dev, &msg);
 837                 else
 838                         err = -ENOTCONN;
 839                 spin_unlock(&ep->lock);
 840                 return err;
 841         }
 842
 843         remote_window = scif_ioremap(alloc->phys_addr, sizeof(*window),
 844                                      ep->remote_dev);
 845
 846         /* Compute the number of lookup entries. 21 == 2MB Shift */
 847         nr_lookup = ALIGN(nr_contig_chunks, SCIF_NR_ADDR_IN_PAGE)
 848                           >> ilog2(SCIF_NR_ADDR_IN_PAGE);
 849
 850         dma_phys_lookup =
 851                 scif_ioremap(remote_window->dma_addr_lookup.offset,
 852                              nr_lookup *
 853                              sizeof(*remote_window->dma_addr_lookup.lookup),
 854                              ep->remote_dev);
 855         num_pages_lookup =
 856                 scif_ioremap(remote_window->num_pages_lookup.offset,
 857                              nr_lookup *
 858                              sizeof(*remote_window->num_pages_lookup.lookup),
 859                              ep->remote_dev);
 860
 861         while (remaining_nr_contig_chunks) {
 862                 loop_nr_contig_chunks = min_t(int, remaining_nr_contig_chunks,
 863                                               (int)SCIF_NR_ADDR_IN_PAGE);
 864                 /* #1/2 - Copy  physical addresses over to the remote side */
 865
 866                 /* #2/2 - Copy DMA addresses (addresses that are fed into the
 867                  * DMA engine) We transfer bus addresses which are then
 868                  * converted into a MIC physical address on the remote
 869                  * side if it is a MIC, if the remote node is a mgmt node we
 870                  * transfer the MIC physical address
 871                  */
 872                 tmp = scif_ioremap(dma_phys_lookup[j],
 873                                    loop_nr_contig_chunks *
 874                                    sizeof(*window->dma_addr),
 875                                    ep->remote_dev);
 876                 tmp1 = scif_ioremap(num_pages_lookup[j],
 877                                     loop_nr_contig_chunks *
 878                                     sizeof(*window->num_pages),
 879                                     ep->remote_dev);
 880                 if (scif_is_mgmt_node()) {
 881                         memcpy_toio((void __force __iomem *)tmp,
 882                                     &window->dma_addr[i], loop_nr_contig_chunks
 883                                     * sizeof(*window->dma_addr));
 884                         memcpy_toio((void __force __iomem *)tmp1,
 885                                     &window->num_pages[i], loop_nr_contig_chunks
 886                                     * sizeof(*window->num_pages));
 887                 } else {
 888                         if (scifdev_is_p2p(ep->remote_dev)) {
 889                                 /*
 890                                  * add remote node's base address for this node
 891                                  * to convert it into a MIC address
 892                                  */
 893                                 int m;
 894                                 dma_addr_t dma_addr;
 895
 896                                 for (m = 0; m < loop_nr_contig_chunks; m++) {
 897                                         dma_addr = window->dma_addr[i + m] +
 898                                                 ep->remote_dev->base_addr;
 899                                         writeq(dma_addr,
 900                                                (void __force __iomem *)&tmp[m]);
 901                                 }
 902                                 memcpy_toio((void __force __iomem *)tmp1,
 903                                             &window->num_pages[i],
 904                                             loop_nr_contig_chunks
 905                                             * sizeof(*window->num_pages));
 906                         } else {
 907                                 /* Mgmt node or loopback - transfer DMA
 908                                  * addresses as is, this is the same as a
 909                                  * MIC physical address (we use the dma_addr
 910                                  * and not the phys_addr array since the
 911                                  * phys_addr is only setup if there is a mmap()
 912                                  * request from the mgmt node)
 913                                  */
 914                                 memcpy_toio((void __force __iomem *)tmp,
 915                                             &window->dma_addr[i],
 916                                             loop_nr_contig_chunks *
 917                                             sizeof(*window->dma_addr));
 918                                 memcpy_toio((void __force __iomem *)tmp1,
 919                                             &window->num_pages[i],
 920                                             loop_nr_contig_chunks *
 921                                             sizeof(*window->num_pages));
 922                         }
 923                 }
 924                 remaining_nr_contig_chunks -= loop_nr_contig_chunks;
 925                 i += loop_nr_contig_chunks;
 926                 j++;
 927                 scif_iounmap(tmp, loop_nr_contig_chunks *
 928                              sizeof(*window->dma_addr), ep->remote_dev);
 929                 scif_iounmap(tmp1, loop_nr_contig_chunks *
 930                              sizeof(*window->num_pages), ep->remote_dev);
 931         }
 932
 933         /* Prepare the remote window for the peer */
 934         remote_window->peer_window = (u64)window;
 935         remote_window->offset = window->offset;
 936         remote_window->prot = window->prot;
 937         remote_window->nr_contig_chunks = nr_contig_chunks;
 938         remote_window->ep = ep->remote_ep;
 939         scif_iounmap(num_pages_lookup,
 940                      nr_lookup *
 941                      sizeof(*remote_window->num_pages_lookup.lookup),
 942                      ep->remote_dev);
 943         scif_iounmap(dma_phys_lookup,
 944                      nr_lookup *
 945                      sizeof(*remote_window->dma_addr_lookup.lookup),
 946                      ep->remote_dev);
 947         scif_iounmap(remote_window, sizeof(*remote_window), ep->remote_dev);
 948         window->peer_window = alloc->vaddr;
 949         return err;
 950 }
 951
 952 /**
 953  * scif_send_scif_register:
 954  * @ep: end point
 955  * @window: self registration window
 956  *
 957  * Send a SCIF_REGISTER message if EP is connected and wait for a
 958  * SCIF_REGISTER_(N)ACK message else send a SCIF_FREE_VIRT
 959  * message so that the peer can free its remote window allocated earlier.
 960  */
 961 static int scif_send_scif_register(struct scif_endpt *ep,
 962                                    struct scif_window *window)
 963 {
 964         int err = 0;
 965         struct scifmsg msg;
 966
 967         msg.src = ep->port;
 968         msg.payload[0] = ep->remote_ep;
 969         msg.payload[1] = window->alloc_handle.vaddr;
 970         msg.payload[2] = (u64)window;
 971         spin_lock(&ep->lock);
 972         if (ep->state == SCIFEP_CONNECTED) {
 973                 msg.uop = SCIF_REGISTER;
 974                 window->reg_state = OP_IN_PROGRESS;
 975                 err = _scif_nodeqp_send(ep->remote_dev, &msg);
 976                 spin_unlock(&ep->lock);
 977                 if (!err) {
 978 retry:
 979                         /* Wait for a SCIF_REGISTER_(N)ACK message */
 980                         err = wait_event_timeout(window->regwq,
 981                                                  window->reg_state !=
 982                                                  OP_IN_PROGRESS,
 983                                                  SCIF_NODE_ALIVE_TIMEOUT);
 984                         if (!err && scifdev_alive(ep))
 985                                 goto retry;
 986                         err = !err ? -ENODEV : 0;
 987                         if (window->reg_state == OP_FAILED)
 988                                 err = -ENOTCONN;
 989                 }
 990         } else {
 991                 msg.uop = SCIF_FREE_VIRT;
 992                 msg.payload[3] = SCIF_REGISTER;
 993                 err = _scif_nodeqp_send(ep->remote_dev, &msg);
 994                 spin_unlock(&ep->lock);
 995                 if (!err)
 996                         err = -ENOTCONN;
 997         }
 998         return err;
 999 }
1000
1001 /**
1002  * scif_get_window_offset:
1003  * @ep: end point descriptor
1004  * @flags: flags
1005  * @offset: offset hint
1006  * @num_pages: number of pages
1007  * @out_offset: computed offset returned by reference.
1008  *
1009  * Compute/Claim a new offset for this EP.
1010  */
1011 int scif_get_window_offset(struct scif_endpt *ep, int flags, s64 offset,
1012                            int num_pages, s64 *out_offset)
1013 {
1014         s64 page_index;
1015         struct iova *iova_ptr;
1016         int err = 0;
1017
1018         if (flags & SCIF_MAP_FIXED) {
1019                 page_index = SCIF_IOVA_PFN(offset);
1020                 iova_ptr = reserve_iova(&ep->rma_info.iovad, page_index,
1021                                         page_index + num_pages - 1);
1022                 if (!iova_ptr)
1023                         err = -EADDRINUSE;
1024         } else {
1025                 iova_ptr = alloc_iova(&ep->rma_info.iovad, num_pages,
1026                                       SCIF_DMA_63BIT_PFN - 1, 0);
1027                 if (!iova_ptr)
1028                         err = -ENOMEM;
1029         }
1030         if (!err)
1031                 *out_offset = (iova_ptr->pfn_lo) << PAGE_SHIFT;
1032         return err;
1033 }
1034
1035 /**
1036  * scif_free_window_offset:
1037  * @ep: end point descriptor
1038  * @window: registration window
1039  * @offset: Offset to be freed
1040  *
1041  * Free offset for this EP. The callee is supposed to grab
1042  * the RMA mutex before calling this API.
1043  */
1044 void scif_free_window_offset(struct scif_endpt *ep,
1045                              struct scif_window *window, s64 offset)
1046 {
1047         if ((window && !window->offset_freed) || !window) {
1048                 free_iova(&ep->rma_info.iovad, offset >> PAGE_SHIFT);
1049                 if (window)
1050                         window->offset_freed = true;
1051         }
1052 }
1053
1054 /**
1055  * scif_alloc_req: Respond to SCIF_ALLOC_REQ interrupt message
1056  * @msg:        Interrupt message
1057  *
1058  * Remote side is requesting a memory allocation.
1059  */
1060 void scif_alloc_req(struct scif_dev *scifdev, struct scifmsg *msg)
1061 {
1062         int err;
1063         struct scif_window *window = NULL;
1064         int nr_pages = msg->payload[1];
1065
1066         window = scif_create_remote_window(scifdev, nr_pages);
1067         if (!window) {
1068                 err = -ENOMEM;
1069                 goto error;
1070         }
1071
1072         /* The peer's allocation request is granted */
1073         msg->uop = SCIF_ALLOC_GNT;
1074         msg->payload[0] = (u64)window;
1075         msg->payload[1] = window->mapped_offset;
1076         err = scif_nodeqp_send(scifdev, msg);
1077         if (err)
1078                 scif_destroy_remote_window(window);
1079         return;
1080 error:
1081         /* The peer's allocation request is rejected */
1082         dev_err(&scifdev->sdev->dev,
1083                 "%s %d error %d alloc_ptr %p nr_pages 0x%x\n",
1084                 __func__, __LINE__, err, window, nr_pages);
1085         msg->uop = SCIF_ALLOC_REJ;
1086         scif_nodeqp_send(scifdev, msg);
1087 }
1088
1089 /**
1090  * scif_alloc_gnt_rej: Respond to SCIF_ALLOC_GNT/REJ interrupt message
1091  * @msg:        Interrupt message
1092  *
1093  * Remote side responded to a memory allocation.
1094  */
1095 void scif_alloc_gnt_rej(struct scif_dev *scifdev, struct scifmsg *msg)
1096 {
1097         struct scif_allocmsg *handle = (struct scif_allocmsg *)msg->payload[2];
1098         struct scif_window *window = container_of(handle, struct scif_window,
1099                                                   alloc_handle);
1100         struct scif_endpt *ep = (struct scif_endpt *)window->ep;
1101
1102         mutex_lock(&ep->rma_info.rma_lock);
1103         handle->vaddr = msg->payload[0];
1104         handle->phys_addr = msg->payload[1];
1105         if (msg->uop == SCIF_ALLOC_GNT)
1106                 handle->state = OP_COMPLETED;
1107         else
1108                 handle->state = OP_FAILED;
1109         wake_up(&handle->allocwq);
1110         mutex_unlock(&ep->rma_info.rma_lock);
1111 }
1112
1113 /**
1114  * scif_free_virt: Respond to SCIF_FREE_VIRT interrupt message
1115  * @msg:        Interrupt message
1116  *
1117  * Free up memory kmalloc'd earlier.
1118  */
1119 void scif_free_virt(struct scif_dev *scifdev, struct scifmsg *msg)
1120 {
1121         struct scif_window *window = (struct scif_window *)msg->payload[1];
1122
1123         scif_destroy_remote_window(window);
1124 }
1125
1126 static void
1127 scif_fixup_aper_base(struct scif_dev *dev, struct scif_window *window)
1128 {
1129         int j;
1130         struct scif_hw_dev *sdev = dev->sdev;
1131         phys_addr_t apt_base = 0;
1132
1133         /*
1134          * Add the aperture base if the DMA address is not card relative
1135          * since the DMA addresses need to be an offset into the bar
1136          */
1137         if (!scifdev_self(dev) && window->type == SCIF_WINDOW_PEER &&
1138             sdev->aper && !sdev->card_rel_da)
1139                 apt_base = sdev->aper->pa;
1140         else
1141                 return;
1142
1143         for (j = 0; j < window->nr_contig_chunks; j++) {
1144                 if (window->num_pages[j])
1145                         window->dma_addr[j] += apt_base;
1146                 else
1147                         break;
1148         }
1149 }
1150
1151 /**
1152  * scif_recv_reg: Respond to SCIF_REGISTER interrupt message
1153  * @msg:        Interrupt message
1154  *
1155  * Update remote window list with a new registered window.
1156  */
1157 void scif_recv_reg(struct scif_dev *scifdev, struct scifmsg *msg)
1158 {
1159         struct scif_endpt *ep = (struct scif_endpt *)msg->payload[0];
1160         struct scif_window *window =
1161                 (struct scif_window *)msg->payload[1];
1162
1163         mutex_lock(&ep->rma_info.rma_lock);
1164         spin_lock(&ep->lock);
1165         if (ep->state == SCIFEP_CONNECTED) {
1166                 msg->uop = SCIF_REGISTER_ACK;
1167                 scif_nodeqp_send(ep->remote_dev, msg);
1168                 scif_fixup_aper_base(ep->remote_dev, window);
1169                 /* No further failures expected. Insert new window */
1170                 scif_insert_window(window, &ep->rma_info.remote_reg_list);
1171         } else {
1172                 msg->uop = SCIF_REGISTER_NACK;
1173                 scif_nodeqp_send(ep->remote_dev, msg);
1174         }
1175         spin_unlock(&ep->lock);
1176         mutex_unlock(&ep->rma_info.rma_lock);
1177         /* free up any lookup resources now that page lists are transferred */
1178         scif_destroy_remote_lookup(ep->remote_dev, window);
1179         /*
1180          * We could not insert the window but we need to
1181          * destroy the window.
1182          */
1183         if (msg->uop == SCIF_REGISTER_NACK)
1184                 scif_destroy_remote_window(window);
1185 }
1186
1187 /**
1188  * scif_recv_unreg: Respond to SCIF_UNREGISTER interrupt message
1189  * @msg:        Interrupt message
1190  *
1191  * Remove window from remote registration list;
1192  */
1193 void scif_recv_unreg(struct scif_dev *scifdev, struct scifmsg *msg)
1194 {
1195         struct scif_rma_req req;
1196         struct scif_window *window = NULL;
1197         struct scif_window *recv_window =
1198                 (struct scif_window *)msg->payload[0];
1199         struct scif_endpt *ep;
1200         int del_window = 0;
1201
1202         ep = (struct scif_endpt *)recv_window->ep;
1203         req.out_window = &window;
1204         req.offset = recv_window->offset;
1205         req.prot = 0;
1206         req.nr_bytes = recv_window->nr_pages << PAGE_SHIFT;
1207         req.type = SCIF_WINDOW_FULL;
1208         req.head = &ep->rma_info.remote_reg_list;
1209         msg->payload[0] = ep->remote_ep;
1210
1211         mutex_lock(&ep->rma_info.rma_lock);
1212         /* Does a valid window exist? */
1213         if (scif_query_window(&req)) {
1214                 dev_err(&scifdev->sdev->dev,
1215                         "%s %d -ENXIO\n", __func__, __LINE__);
1216                 msg->uop = SCIF_UNREGISTER_ACK;
1217                 goto error;
1218         }
1219         if (window) {
1220                 if (window->ref_count)
1221                         scif_put_window(window, window->nr_pages);
1222                 else
1223                         dev_err(&scifdev->sdev->dev,
1224                                 "%s %d ref count should be +ve\n",
1225                                 __func__, __LINE__);
1226                 window->unreg_state = OP_COMPLETED;
1227                 if (!window->ref_count) {
1228                         msg->uop = SCIF_UNREGISTER_ACK;
1229                         atomic_inc(&ep->rma_info.tw_refcount);
1230                         ep->rma_info.async_list_del = 1;
1231                         list_del_init(&window->list);
1232                         del_window = 1;
1233                 } else {
1234                         /* NACK! There are valid references to this window */
1235                         msg->uop = SCIF_UNREGISTER_NACK;
1236                 }
1237         } else {
1238                 /* The window did not make its way to the list at all. ACK */
1239                 msg->uop = SCIF_UNREGISTER_ACK;
1240                 scif_destroy_remote_window(recv_window);
1241         }
1242 error:
1243         mutex_unlock(&ep->rma_info.rma_lock);
1244         if (del_window)
1245                 scif_drain_dma_intr(ep->remote_dev->sdev,
1246                                     ep->rma_info.dma_chan);
1247         scif_nodeqp_send(ep->remote_dev, msg);
1248         if (del_window)
1249                 scif_queue_for_cleanup(window, &scif_info.rma);
1250 }
1251
1252 /**
1253  * scif_recv_reg_ack: Respond to SCIF_REGISTER_ACK interrupt message
1254  * @msg:        Interrupt message
1255  *
1256  * Wake up the window waiting to complete registration.
1257  */
1258 void scif_recv_reg_ack(struct scif_dev *scifdev, struct scifmsg *msg)
1259 {
1260         struct scif_window *window =
1261                 (struct scif_window *)msg->payload[2];
1262         struct scif_endpt *ep = (struct scif_endpt *)window->ep;
1263
1264         mutex_lock(&ep->rma_info.rma_lock);
1265         window->reg_state = OP_COMPLETED;
1266         wake_up(&window->regwq);
1267         mutex_unlock(&ep->rma_info.rma_lock);
1268 }
1269
1270 /**
1271  * scif_recv_reg_nack: Respond to SCIF_REGISTER_NACK interrupt message
1272  * @msg:        Interrupt message
1273  *
1274  * Wake up the window waiting to inform it that registration
1275  * cannot be completed.
1276  */
1277 void scif_recv_reg_nack(struct scif_dev *scifdev, struct scifmsg *msg)
1278 {
1279         struct scif_window *window =
1280                 (struct scif_window *)msg->payload[2];
1281         struct scif_endpt *ep = (struct scif_endpt *)window->ep;
1282
1283         mutex_lock(&ep->rma_info.rma_lock);
1284         window->reg_state = OP_FAILED;
1285         wake_up(&window->regwq);
1286         mutex_unlock(&ep->rma_info.rma_lock);
1287 }
1288
1289 /**
1290  * scif_recv_unreg_ack: Respond to SCIF_UNREGISTER_ACK interrupt message
1291  * @msg:        Interrupt message
1292  *
1293  * Wake up the window waiting to complete unregistration.
1294  */
1295 void scif_recv_unreg_ack(struct scif_dev *scifdev, struct scifmsg *msg)
1296 {
1297         struct scif_window *window =
1298                 (struct scif_window *)msg->payload[1];
1299         struct scif_endpt *ep = (struct scif_endpt *)window->ep;
1300
1301         mutex_lock(&ep->rma_info.rma_lock);
1302         window->unreg_state = OP_COMPLETED;
1303         wake_up(&window->unregwq);
1304         mutex_unlock(&ep->rma_info.rma_lock);
1305 }
1306
1307 /**
1308  * scif_recv_unreg_nack: Respond to SCIF_UNREGISTER_NACK interrupt message
1309  * @msg:        Interrupt message
1310  *
1311  * Wake up the window waiting to inform it that unregistration
1312  * cannot be completed immediately.
1313  */
1314 void scif_recv_unreg_nack(struct scif_dev *scifdev, struct scifmsg *msg)
1315 {
1316         struct scif_window *window =
1317                 (struct scif_window *)msg->payload[1];
1318         struct scif_endpt *ep = (struct scif_endpt *)window->ep;
1319
1320         mutex_lock(&ep->rma_info.rma_lock);
1321         window->unreg_state = OP_FAILED;
1322         wake_up(&window->unregwq);
1323         mutex_unlock(&ep->rma_info.rma_lock);
1324 }
1325
1326 int __scif_pin_pages(void *addr, size_t len, int *out_prot,
1327                      int map_flags, scif_pinned_pages_t *pages)
1328 {
1329         struct scif_pinned_pages *pinned_pages;
1330         int nr_pages, err = 0, i;
1331         bool vmalloc_addr = false;
1332         bool try_upgrade = false;
1333         int prot = *out_prot;
1334         int ulimit = 0;
1335         struct mm_struct *mm = NULL;
1336
1337         /* Unsupported flags */
1338         if (map_flags & ~(SCIF_MAP_KERNEL | SCIF_MAP_ULIMIT))
1339                 return -EINVAL;
1340         ulimit = !!(map_flags & SCIF_MAP_ULIMIT);
1341
1342         /* Unsupported protection requested */
1343         if (prot & ~(SCIF_PROT_READ | SCIF_PROT_WRITE))
1344                 return -EINVAL;
1345
1346         /* addr/len must be page aligned. len should be non zero */
1347         if (!len ||
1348             (ALIGN((u64)addr, PAGE_SIZE) != (u64)addr) ||
1349             (ALIGN((u64)len, PAGE_SIZE) != (u64)len))
1350                 return -EINVAL;
1351
1352         might_sleep();
1353
1354         nr_pages = len >> PAGE_SHIFT;
1355
1356         /* Allocate a set of pinned pages */
1357         pinned_pages = scif_create_pinned_pages(nr_pages, prot);
1358         if (!pinned_pages)
1359                 return -ENOMEM;
1360
1361         if (map_flags & SCIF_MAP_KERNEL) {
1362                 if (is_vmalloc_addr(addr))
1363                         vmalloc_addr = true;
1364
1365                 for (i = 0; i < nr_pages; i++) {
1366                         if (vmalloc_addr)
1367                                 pinned_pages->pages[i] =
1368                                         vmalloc_to_page(addr + (i * PAGE_SIZE));
1369                         else
1370                                 pinned_pages->pages[i] =
1371                                         virt_to_page(addr + (i * PAGE_SIZE));
1372                 }
1373                 pinned_pages->nr_pages = nr_pages;
1374                 pinned_pages->map_flags = SCIF_MAP_KERNEL;
1375         } else {
1376                 /*
1377                  * SCIF supports registration caching. If a registration has
1378                  * been requested with read only permissions, then we try
1379                  * to pin the pages with RW permissions so that a subsequent
1380                  * transfer with RW permission can hit the cache instead of
1381                  * invalidating it. If the upgrade fails with RW then we
1382                  * revert back to R permission and retry
1383                  */
1384                 if (prot == SCIF_PROT_READ)
1385                         try_upgrade = true;
1386                 prot |= SCIF_PROT_WRITE;
1387 retry:
1388                 mm = current->mm;
1389                 down_write(&mm->mmap_sem);
1390                 if (ulimit) {
1391                         err = __scif_check_inc_pinned_vm(mm, nr_pages);
1392                         if (err) {
1393                                 up_write(&mm->mmap_sem);
1394                                 pinned_pages->nr_pages = 0;
1395                                 goto error_unmap;
1396                         }
1397                 }
1398
1399                 pinned_pages->nr_pages = get_user_pages(
1400                                 (u64)addr,
1401                                 nr_pages,
1402                                 (prot & SCIF_PROT_WRITE) ? FOLL_WRITE : 0,
1403                                 pinned_pages->pages,
1404                                 NULL);
1405                 up_write(&mm->mmap_sem);
1406                 if (nr_pages != pinned_pages->nr_pages) {
1407                         if (try_upgrade) {
1408                                 if (ulimit)
1409                                         __scif_dec_pinned_vm_lock(mm,
1410                                                                   nr_pages, 0);
1411                                 /* Roll back any pinned pages */
1412                                 for (i = 0; i < pinned_pages->nr_pages; i++) {
1413                                         if (pinned_pages->pages[i])
1414                                                 put_page(
1415                                                 pinned_pages->pages[i]);
1416                                 }
1417                                 prot &= ~SCIF_PROT_WRITE;
1418                                 try_upgrade = false;
1419                                 goto retry;
1420                         }
1421                 }
1422                 pinned_pages->map_flags = 0;
1423         }
1424
1425         if (pinned_pages->nr_pages < nr_pages) {
1426                 err = -EFAULT;
1427                 pinned_pages->nr_pages = nr_pages;
1428                 goto dec_pinned;
1429         }
1430
1431         *out_prot = prot;
1432         atomic_set(&pinned_pages->ref_count, 1);
1433         *pages = pinned_pages;
1434         return err;
1435 dec_pinned:
1436         if (ulimit)
1437                 __scif_dec_pinned_vm_lock(mm, nr_pages, 0);
1438         /* Something went wrong! Rollback */
1439 error_unmap:
1440         pinned_pages->nr_pages = nr_pages;
1441         scif_destroy_pinned_pages(pinned_pages);
1442         *pages = NULL;
1443         dev_dbg(scif_info.mdev.this_device,
1444                 "%s %d err %d len 0x%lx\n", __func__, __LINE__, err, len);
1445         return err;
1446 }
1447
1448 int scif_pin_pages(void *addr, size_t len, int prot,
1449                    int map_flags, scif_pinned_pages_t *pages)
1450 {
1451         return __scif_pin_pages(addr, len, &prot, map_flags, pages);
1452 }
1453 EXPORT_SYMBOL_GPL(scif_pin_pages);
1454
1455 int scif_unpin_pages(scif_pinned_pages_t pinned_pages)
1456 {
1457         int err = 0, ret;
1458
1459         if (!pinned_pages || SCIFEP_MAGIC != pinned_pages->magic)
1460                 return -EINVAL;
1461
1462         ret = atomic_sub_return(1, &pinned_pages->ref_count);
1463         if (ret < 0) {
1464                 dev_err(scif_info.mdev.this_device,
1465                         "%s %d scif_unpin_pages called without pinning? rc %d\n",
1466                         __func__, __LINE__, ret);
1467                 return -EINVAL;
1468         }
1469         /*
1470          * Destroy the window if the ref count for this set of pinned
1471          * pages has dropped to zero. If it is positive then there is
1472          * a valid registered window which is backed by these pages and
1473          * it will be destroyed once all such windows are unregistered.
1474          */
1475         if (!ret)
1476                 err = scif_destroy_pinned_pages(pinned_pages);
1477
1478         return err;
1479 }
1480 EXPORT_SYMBOL_GPL(scif_unpin_pages);
1481
1482 static inline void
1483 scif_insert_local_window(struct scif_window *window, struct scif_endpt *ep)
1484 {
1485         mutex_lock(&ep->rma_info.rma_lock);
1486         scif_insert_window(window, &ep->rma_info.reg_list);
1487         mutex_unlock(&ep->rma_info.rma_lock);
1488 }
1489
1490 off_t scif_register_pinned_pages(scif_epd_t epd,
1491                                  scif_pinned_pages_t pinned_pages,
1492                                  off_t offset, int map_flags)
1493 {
1494         struct scif_endpt *ep = (struct scif_endpt *)epd;
1495         s64 computed_offset;
1496         struct scif_window *window;
1497         int err;
1498         size_t len;
1499         struct device *spdev;
1500
1501         /* Unsupported flags */
1502         if (map_flags & ~SCIF_MAP_FIXED)
1503                 return -EINVAL;
1504
1505         len = pinned_pages->nr_pages << PAGE_SHIFT;
1506
1507         /*
1508          * Offset is not page aligned/negative or offset+len
1509          * wraps around with SCIF_MAP_FIXED.
1510          */
1511         if ((map_flags & SCIF_MAP_FIXED) &&
1512             ((ALIGN(offset, PAGE_SIZE) != offset) ||
1513             (offset < 0) ||
1514             (len > LONG_MAX - offset)))
1515                 return -EINVAL;
1516
1517         might_sleep();
1518
1519         err = scif_verify_epd(ep);
1520         if (err)
1521                 return err;
1522         /*
1523          * It is an error to pass pinned_pages to scif_register_pinned_pages()
1524          * after calling scif_unpin_pages().
1525          */
1526         if (!atomic_add_unless(&pinned_pages->ref_count, 1, 0))
1527                 return -EINVAL;
1528
1529         /* Compute the offset for this registration */
1530         err = scif_get_window_offset(ep, map_flags, offset,
1531                                      len, &computed_offset);
1532         if (err) {
1533                 atomic_sub(1, &pinned_pages->ref_count);
1534                 return err;
1535         }
1536
1537         /* Allocate and prepare self registration window */
1538         window = scif_create_window(ep, pinned_pages->nr_pages,
1539                                     computed_offset, false);
1540         if (!window) {
1541                 atomic_sub(1, &pinned_pages->ref_count);
1542                 scif_free_window_offset(ep, NULL, computed_offset);
1543                 return -ENOMEM;
1544         }
1545
1546         window->pinned_pages = pinned_pages;
1547         window->nr_pages = pinned_pages->nr_pages;
1548         window->prot = pinned_pages->prot;
1549
1550         spdev = scif_get_peer_dev(ep->remote_dev);
1551         if (IS_ERR(spdev)) {
1552                 err = PTR_ERR(spdev);
1553                 scif_destroy_window(ep, window);
1554                 return err;
1555         }
1556         err = scif_send_alloc_request(ep, window);
1557         if (err) {
1558                 dev_err(&ep->remote_dev->sdev->dev,
1559                         "%s %d err %d\n", __func__, __LINE__, err);
1560                 goto error_unmap;
1561         }
1562
1563         /* Prepare the remote registration window */
1564         err = scif_prep_remote_window(ep, window);
1565         if (err) {
1566                 dev_err(&ep->remote_dev->sdev->dev,
1567                         "%s %d err %d\n", __func__, __LINE__, err);
1568                 goto error_unmap;
1569         }
1570
1571         /* Tell the peer about the new window */
1572         err = scif_send_scif_register(ep, window);
1573         if (err) {
1574                 dev_err(&ep->remote_dev->sdev->dev,
1575                         "%s %d err %d\n", __func__, __LINE__, err);
1576                 goto error_unmap;
1577         }
1578
1579         scif_put_peer_dev(spdev);
1580         /* No further failures expected. Insert new window */
1581         scif_insert_local_window(window, ep);
1582         return computed_offset;
1583 error_unmap:
1584         scif_destroy_window(ep, window);
1585         scif_put_peer_dev(spdev);
1586         dev_err(&ep->remote_dev->sdev->dev,
1587                 "%s %d err %d\n", __func__, __LINE__, err);
1588         return err;
1589 }
1590 EXPORT_SYMBOL_GPL(scif_register_pinned_pages);
1591
1592 off_t scif_register(scif_epd_t epd, void *addr, size_t len, off_t offset,
1593                     int prot, int map_flags)
1594 {
1595         scif_pinned_pages_t pinned_pages;
1596         off_t err;
1597         struct scif_endpt *ep = (struct scif_endpt *)epd;
1598         s64 computed_offset;
1599         struct scif_window *window;
1600         struct mm_struct *mm = NULL;
1601         struct device *spdev;
1602
1603         dev_dbg(scif_info.mdev.this_device,
1604                 "SCIFAPI register: ep %p addr %p len 0x%lx offset 0x%lx prot 0x%x map_flags 0x%x\n",
1605                 epd, addr, len, offset, prot, map_flags);
1606         /* Unsupported flags */
1607         if (map_flags & ~(SCIF_MAP_FIXED | SCIF_MAP_KERNEL))
1608                 return -EINVAL;
1609
1610         /*
1611          * Offset is not page aligned/negative or offset+len
1612          * wraps around with SCIF_MAP_FIXED.
1613          */
1614         if ((map_flags & SCIF_MAP_FIXED) &&
1615             ((ALIGN(offset, PAGE_SIZE) != offset) ||
1616             (offset < 0) ||
1617             (len > LONG_MAX - offset)))
1618                 return -EINVAL;
1619
1620         /* Unsupported protection requested */
1621         if (prot & ~(SCIF_PROT_READ | SCIF_PROT_WRITE))
1622                 return -EINVAL;
1623
1624         /* addr/len must be page aligned. len should be non zero */
1625         if (!len || (ALIGN((u64)addr, PAGE_SIZE) != (u64)addr) ||
1626             (ALIGN(len, PAGE_SIZE) != len))
1627                 return -EINVAL;
1628
1629         might_sleep();
1630
1631         err = scif_verify_epd(ep);
1632         if (err)
1633                 return err;
1634
1635         /* Compute the offset for this registration */
1636         err = scif_get_window_offset(ep, map_flags, offset,
1637                                      len >> PAGE_SHIFT, &computed_offset);
1638         if (err)
1639                 return err;
1640
1641         spdev = scif_get_peer_dev(ep->remote_dev);
1642         if (IS_ERR(spdev)) {
1643                 err = PTR_ERR(spdev);
1644                 scif_free_window_offset(ep, NULL, computed_offset);
1645                 return err;
1646         }
1647         /* Allocate and prepare self registration window */
1648         window = scif_create_window(ep, len >> PAGE_SHIFT,
1649                                     computed_offset, false);
1650         if (!window) {
1651                 scif_free_window_offset(ep, NULL, computed_offset);
1652                 scif_put_peer_dev(spdev);
1653                 return -ENOMEM;
1654         }
1655
1656         window->nr_pages = len >> PAGE_SHIFT;
1657
1658         err = scif_send_alloc_request(ep, window);
1659         if (err) {
1660                 scif_destroy_incomplete_window(ep, window);
1661                 scif_put_peer_dev(spdev);
1662                 return err;
1663         }
1664
1665         if (!(map_flags & SCIF_MAP_KERNEL)) {
1666                 mm = __scif_acquire_mm();
1667                 map_flags |= SCIF_MAP_ULIMIT;
1668         }
1669         /* Pin down the pages */
1670         err = __scif_pin_pages(addr, len, &prot,
1671                                map_flags & (SCIF_MAP_KERNEL | SCIF_MAP_ULIMIT),
1672                                &pinned_pages);
1673         if (err) {
1674                 scif_destroy_incomplete_window(ep, window);
1675                 __scif_release_mm(mm);
1676                 goto error;
1677         }
1678
1679         window->pinned_pages = pinned_pages;
1680         window->prot = pinned_pages->prot;
1681         window->mm = mm;
1682
1683         /* Prepare the remote registration window */
1684         err = scif_prep_remote_window(ep, window);
1685         if (err) {
1686                 dev_err(&ep->remote_dev->sdev->dev,
1687                         "%s %d err %ld\n", __func__, __LINE__, err);
1688                 goto error_unmap;
1689         }
1690
1691         /* Tell the peer about the new window */
1692         err = scif_send_scif_register(ep, window);
1693         if (err) {
1694                 dev_err(&ep->remote_dev->sdev->dev,
1695                         "%s %d err %ld\n", __func__, __LINE__, err);
1696                 goto error_unmap;
1697         }
1698
1699         scif_put_peer_dev(spdev);
1700         /* No further failures expected. Insert new window */
1701         scif_insert_local_window(window, ep);
1702         dev_dbg(&ep->remote_dev->sdev->dev,
1703                 "SCIFAPI register: ep %p addr %p len 0x%lx computed_offset 0x%llx\n",
1704                 epd, addr, len, computed_offset);
1705         return computed_offset;
1706 error_unmap:
1707         scif_destroy_window(ep, window);
1708 error:
1709         scif_put_peer_dev(spdev);
1710         dev_err(&ep->remote_dev->sdev->dev,
1711                 "%s %d err %ld\n", __func__, __LINE__, err);
1712         return err;
1713 }
1714 EXPORT_SYMBOL_GPL(scif_register);
1715
1716 int
1717 scif_unregister(scif_epd_t epd, off_t offset, size_t len)
1718 {
1719         struct scif_endpt *ep = (struct scif_endpt *)epd;
1720         struct scif_window *window = NULL;
1721         struct scif_rma_req req;
1722         int nr_pages, err;
1723         struct device *spdev;
1724
1725         dev_dbg(scif_info.mdev.this_device,
1726                 "SCIFAPI unregister: ep %p offset 0x%lx len 0x%lx\n",
1727                 ep, offset, len);
1728         /* len must be page aligned. len should be non zero */
1729         if (!len ||
1730             (ALIGN((u64)len, PAGE_SIZE) != (u64)len))
1731                 return -EINVAL;
1732
1733         /* Offset is not page aligned or offset+len wraps around */
1734         if ((ALIGN(offset, PAGE_SIZE) != offset) ||
1735             (offset < 0) ||
1736             (len > LONG_MAX - offset))
1737                 return -EINVAL;
1738
1739         err = scif_verify_epd(ep);
1740         if (err)
1741                 return err;
1742
1743         might_sleep();
1744         nr_pages = len >> PAGE_SHIFT;
1745
1746         req.out_window = &window;
1747         req.offset = offset;
1748         req.prot = 0;
1749         req.nr_bytes = len;
1750         req.type = SCIF_WINDOW_FULL;
1751         req.head = &ep->rma_info.reg_list;
1752
1753         spdev = scif_get_peer_dev(ep->remote_dev);
1754         if (IS_ERR(spdev)) {
1755                 err = PTR_ERR(spdev);
1756                 return err;
1757         }
1758         mutex_lock(&ep->rma_info.rma_lock);
1759         /* Does a valid window exist? */
1760         err = scif_query_window(&req);
1761         if (err) {
1762                 dev_err(&ep->remote_dev->sdev->dev,
1763                         "%s %d err %d\n", __func__, __LINE__, err);
1764                 goto error;
1765         }
1766         /* Unregister all the windows in this range */
1767         err = scif_rma_list_unregister(window, offset, nr_pages);
1768         if (err)
1769                 dev_err(&ep->remote_dev->sdev->dev,
1770                         "%s %d err %d\n", __func__, __LINE__, err);
1771 error:
1772         mutex_unlock(&ep->rma_info.rma_lock);
1773         scif_put_peer_dev(spdev);
1774         return err;
1775 }
1776 EXPORT_SYMBOL_GPL(scif_unregister);