drivers/misc/mic/scif/scif

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This source file includes following definitions.
scif_rma_ep_init
scif_rma_ep_can_uninit
scif_create_pinned_pages
scif_destroy_pinned_pages
scif_create_window
scif_destroy_incomplete_window
scif_unmap_window
__scif_acquire_mm
__scif_release_mm
__scif_dec_pinned_vm_lock
__scif_check_inc_pinned_vm
scif_destroy_window
scif_create_remote_lookup
scif_destroy_remote_lookup
scif_create_remote_window
scif_destroy_remote_window
scif_iommu_map
scif_map_window
scif_send_scif_unregister
scif_unregister_window
scif_send_alloc_request
scif_prep_remote_window
scif_send_scif_register
scif_get_window_offset
scif_free_window_offset
scif_alloc_req
scif_alloc_gnt_rej
scif_free_virt
scif_fixup_aper_base
scif_recv_reg
scif_recv_unreg
scif_recv_reg_ack
scif_recv_reg_nack
scif_recv_unreg_ack
scif_recv_unreg_nack
__scif_pin_pages
scif_pin_pages
scif_unpin_pages
scif_insert_local_window
scif_register_pinned_pages
scif_register
scif_unregister
   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Intel MIC Platform Software Stack (MPSS)
   4  *
   5  * Copyright(c) 2015 Intel Corporation.
   6  *
   7  * Intel SCIF driver.
   8  */
   9 #include <linux/intel-iommu.h>
  10 #include <linux/pagemap.h>
  11 #include <linux/sched/mm.h>
  12 #include <linux/sched/signal.h>
  13 
  14 #include "scif_main.h"
  15 #include "scif_map.h"
  16 
  17 /* Used to skip ulimit checks for registrations with SCIF_MAP_KERNEL flag */
  18 #define SCIF_MAP_ULIMIT 0x40
  19 
  20 bool scif_ulimit_check = 1;
  21 
  22 /**
  23  * scif_rma_ep_init:
  24  * @ep: end point
  25  *
  26  * Initialize RMA per EP data structures.
  27  */
  28 void scif_rma_ep_init(struct scif_endpt *ep)
  29 {
  30         struct scif_endpt_rma_info *rma = &ep->rma_info;
  31 
  32         mutex_init(&rma->rma_lock);
  33         init_iova_domain(&rma->iovad, PAGE_SIZE, SCIF_IOVA_START_PFN);
  34         spin_lock_init(&rma->tc_lock);
  35         mutex_init(&rma->mmn_lock);
  36         INIT_LIST_HEAD(&rma->reg_list);
  37         INIT_LIST_HEAD(&rma->remote_reg_list);
  38         atomic_set(&rma->tw_refcount, 0);
  39         atomic_set(&rma->tcw_refcount, 0);
  40         atomic_set(&rma->tcw_total_pages, 0);
  41         atomic_set(&rma->fence_refcount, 0);
  42 
  43         rma->async_list_del = 0;
  44         rma->dma_chan = NULL;
  45         INIT_LIST_HEAD(&rma->mmn_list);
  46         INIT_LIST_HEAD(&rma->vma_list);
  47         init_waitqueue_head(&rma->markwq);
  48 }
  49 
  50 /**
  51  * scif_rma_ep_can_uninit:
  52  * @ep: end point
  53  *
  54  * Returns 1 if an endpoint can be uninitialized and 0 otherwise.
  55  */
  56 int scif_rma_ep_can_uninit(struct scif_endpt *ep)
  57 {
  58         int ret = 0;
  59 
  60         mutex_lock(&ep->rma_info.rma_lock);
  61         /* Destroy RMA Info only if both lists are empty */
  62         if (list_empty(&ep->rma_info.reg_list) &&
  63             list_empty(&ep->rma_info.remote_reg_list) &&
  64             list_empty(&ep->rma_info.mmn_list) &&
  65             !atomic_read(&ep->rma_info.tw_refcount) &&
  66             !atomic_read(&ep->rma_info.tcw_refcount) &&
  67             !atomic_read(&ep->rma_info.fence_refcount))
  68                 ret = 1;
  69         mutex_unlock(&ep->rma_info.rma_lock);
  70         return ret;
  71 }
  72 
  73 /**
  74  * scif_create_pinned_pages:
  75  * @nr_pages: number of pages in window
  76  * @prot: read/write protection
  77  *
  78  * Allocate and prepare a set of pinned pages.
  79  */
  80 static struct scif_pinned_pages *
  81 scif_create_pinned_pages(int nr_pages, int prot)
  82 {
  83         struct scif_pinned_pages *pin;
  84 
  85         might_sleep();
  86         pin = scif_zalloc(sizeof(*pin));
  87         if (!pin)
  88                 goto error;
  89 
  90         pin->pages = scif_zalloc(nr_pages * sizeof(*pin->pages));
  91         if (!pin->pages)
  92                 goto error_free_pinned_pages;
  93 
  94         pin->prot = prot;
  95         pin->magic = SCIFEP_MAGIC;
  96         return pin;
  97 
  98 error_free_pinned_pages:
  99         scif_free(pin, sizeof(*pin));
 100 error:
 101         return NULL;
 102 }
 103 
 104 /**
 105  * scif_destroy_pinned_pages:
 106  * @pin: A set of pinned pages.
 107  *
 108  * Deallocate resources for pinned pages.
 109  */
 110 static int scif_destroy_pinned_pages(struct scif_pinned_pages *pin)
 111 {
 112         int j;
 113         int writeable = pin->prot & SCIF_PROT_WRITE;
 114         int kernel = SCIF_MAP_KERNEL & pin->map_flags;
 115 
 116         for (j = 0; j < pin->nr_pages; j++) {
 117                 if (pin->pages[j] && !kernel) {
 118                         if (writeable)
 119                                 SetPageDirty(pin->pages[j]);
 120                         put_page(pin->pages[j]);
 121                 }
 122         }
 123 
 124         scif_free(pin->pages,
 125                   pin->nr_pages * sizeof(*pin->pages));
 126         scif_free(pin, sizeof(*pin));
 127         return 0;
 128 }
 129 
 130 /*
 131  * scif_create_window:
 132  * @ep: end point
 133  * @nr_pages: number of pages
 134  * @offset: registration offset
 135  * @temp: true if a temporary window is being created
 136  *
 137  * Allocate and prepare a self registration window.
 138  */
 139 struct scif_window *scif_create_window(struct scif_endpt *ep, int nr_pages,
 140                                        s64 offset, bool temp)
 141 {
 142         struct scif_window *window;
 143 
 144         might_sleep();
 145         window = scif_zalloc(sizeof(*window));
 146         if (!window)
 147                 goto error;
 148 
 149         window->dma_addr = scif_zalloc(nr_pages * sizeof(*window->dma_addr));
 150         if (!window->dma_addr)
 151                 goto error_free_window;
 152 
 153         window->num_pages = scif_zalloc(nr_pages * sizeof(*window->num_pages));
 154         if (!window->num_pages)
 155                 goto error_free_window;
 156 
 157         window->offset = offset;
 158         window->ep = (u64)ep;
 159         window->magic = SCIFEP_MAGIC;
 160         window->reg_state = OP_IDLE;
 161         init_waitqueue_head(&window->regwq);
 162         window->unreg_state = OP_IDLE;
 163         init_waitqueue_head(&window->unregwq);
 164         INIT_LIST_HEAD(&window->list);
 165         window->type = SCIF_WINDOW_SELF;
 166         window->temp = temp;
 167         return window;
 168 
 169 error_free_window:
 170         scif_free(window->dma_addr,
 171                   nr_pages * sizeof(*window->dma_addr));
 172         scif_free(window, sizeof(*window));
 173 error:
 174         return NULL;
 175 }
 176 
 177 /**
 178  * scif_destroy_incomplete_window:
 179  * @ep: end point
 180  * @window: registration window
 181  *
 182  * Deallocate resources for self window.
 183  */
 184 static void scif_destroy_incomplete_window(struct scif_endpt *ep,
 185                                            struct scif_window *window)
 186 {
 187         int err;
 188         int nr_pages = window->nr_pages;
 189         struct scif_allocmsg *alloc = &window->alloc_handle;
 190         struct scifmsg msg;
 191 
 192 retry:
 193         /* Wait for a SCIF_ALLOC_GNT/REJ message */
 194         err = wait_event_timeout(alloc->allocwq,
 195                                  alloc->state != OP_IN_PROGRESS,
 196                                  SCIF_NODE_ALIVE_TIMEOUT);
 197         if (!err && scifdev_alive(ep))
 198                 goto retry;
 199 
 200         mutex_lock(&ep->rma_info.rma_lock);
 201         if (alloc->state == OP_COMPLETED) {
 202                 msg.uop = SCIF_FREE_VIRT;
 203                 msg.src = ep->port;
 204                 msg.payload[0] = ep->remote_ep;
 205                 msg.payload[1] = window->alloc_handle.vaddr;
 206                 msg.payload[2] = (u64)window;
 207                 msg.payload[3] = SCIF_REGISTER;
 208                 _scif_nodeqp_send(ep->remote_dev, &msg);
 209         }
 210         mutex_unlock(&ep->rma_info.rma_lock);
 211 
 212         scif_free_window_offset(ep, window, window->offset);
 213         scif_free(window->dma_addr, nr_pages * sizeof(*window->dma_addr));
 214         scif_free(window->num_pages, nr_pages * sizeof(*window->num_pages));
 215         scif_free(window, sizeof(*window));
 216 }
 217 
 218 /**
 219  * scif_unmap_window:
 220  * @remote_dev: SCIF remote device
 221  * @window: registration window
 222  *
 223  * Delete any DMA mappings created for a registered self window
 224  */
 225 void scif_unmap_window(struct scif_dev *remote_dev, struct scif_window *window)
 226 {
 227         int j;
 228 
 229         if (scif_is_iommu_enabled() && !scifdev_self(remote_dev)) {
 230                 if (window->st) {
 231                         dma_unmap_sg(&remote_dev->sdev->dev,
 232                                      window->st->sgl, window->st->nents,
 233                                      DMA_BIDIRECTIONAL);
 234                         sg_free_table(window->st);
 235                         kfree(window->st);
 236                         window->st = NULL;
 237                 }
 238         } else {
 239                 for (j = 0; j < window->nr_contig_chunks; j++) {
 240                         if (window->dma_addr[j]) {
 241                                 scif_unmap_single(window->dma_addr[j],
 242                                                   remote_dev,
 243                                                   window->num_pages[j] <<
 244                                                   PAGE_SHIFT);
 245                                 window->dma_addr[j] = 0x0;
 246                         }
 247                 }
 248         }
 249 }
 250 
 251 static inline struct mm_struct *__scif_acquire_mm(void)
 252 {
 253         if (scif_ulimit_check)
 254                 return get_task_mm(current);
 255         return NULL;
 256 }
 257 
 258 static inline void __scif_release_mm(struct mm_struct *mm)
 259 {
 260         if (mm)
 261                 mmput(mm);
 262 }
 263 
 264 static inline int
 265 __scif_dec_pinned_vm_lock(struct mm_struct *mm,
 266                           int nr_pages)
 267 {
 268         if (!mm || !nr_pages || !scif_ulimit_check)
 269                 return 0;
 270 
 271         atomic64_sub(nr_pages, &mm->pinned_vm);
 272         return 0;
 273 }
 274 
 275 static inline int __scif_check_inc_pinned_vm(struct mm_struct *mm,
 276                                              int nr_pages)
 277 {
 278         unsigned long locked, lock_limit;
 279 
 280         if (!mm || !nr_pages || !scif_ulimit_check)
 281                 return 0;
 282 
 283         lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
 284         locked = atomic64_add_return(nr_pages, &mm->pinned_vm);
 285 
 286         if ((locked > lock_limit) && !capable(CAP_IPC_LOCK)) {
 287                 atomic64_sub(nr_pages, &mm->pinned_vm);
 288                 dev_err(scif_info.mdev.this_device,
 289                         "locked(%lu) > lock_limit(%lu)\n",
 290                         locked, lock_limit);
 291                 return -ENOMEM;
 292         }
 293         return 0;
 294 }
 295 
 296 /**
 297  * scif_destroy_window:
 298  * @ep: end point
 299  * @window: registration window
 300  *
 301  * Deallocate resources for self window.
 302  */
 303 int scif_destroy_window(struct scif_endpt *ep, struct scif_window *window)
 304 {
 305         int j;
 306         struct scif_pinned_pages *pinned_pages = window->pinned_pages;
 307         int nr_pages = window->nr_pages;
 308 
 309         might_sleep();
 310         if (!window->temp && window->mm) {
 311                 __scif_dec_pinned_vm_lock(window->mm, window->nr_pages);
 312                 __scif_release_mm(window->mm);
 313                 window->mm = NULL;
 314         }
 315 
 316         scif_free_window_offset(ep, window, window->offset);
 317         scif_unmap_window(ep->remote_dev, window);
 318         /*
 319          * Decrement references for this set of pinned pages from
 320          * this window.
 321          */
 322         j = atomic_sub_return(1, &pinned_pages->ref_count);
 323         if (j < 0)
 324                 dev_err(scif_info.mdev.this_device,
 325                         "%s %d incorrect ref count %d\n",
 326                         __func__, __LINE__, j);
 327         /*
 328          * If the ref count for pinned_pages is zero then someone
 329          * has already called scif_unpin_pages() for it and we should
 330          * destroy the page cache.
 331          */
 332         if (!j)
 333                 scif_destroy_pinned_pages(window->pinned_pages);
 334         scif_free(window->dma_addr, nr_pages * sizeof(*window->dma_addr));
 335         scif_free(window->num_pages, nr_pages * sizeof(*window->num_pages));
 336         window->magic = 0;
 337         scif_free(window, sizeof(*window));
 338         return 0;
 339 }
 340 
 341 /**
 342  * scif_create_remote_lookup:
 343  * @remote_dev: SCIF remote device
 344  * @window: remote window
 345  *
 346  * Allocate and prepare lookup entries for the remote
 347  * end to copy over the physical addresses.
 348  * Returns 0 on success and appropriate errno on failure.
 349  */
 350 static int scif_create_remote_lookup(struct scif_dev *remote_dev,
 351                                      struct scif_window *window)
 352 {
 353         int i, j, err = 0;
 354         int nr_pages = window->nr_pages;
 355         bool vmalloc_dma_phys, vmalloc_num_pages;
 356 
 357         might_sleep();
 358         /* Map window */
 359         err = scif_map_single(&window->mapped_offset,
 360                               window, remote_dev, sizeof(*window));
 361         if (err)
 362                 goto error_window;
 363 
 364         /* Compute the number of lookup entries. 21 == 2MB Shift */
 365         window->nr_lookup = ALIGN(nr_pages * PAGE_SIZE,
 366                                         ((2) * 1024 * 1024)) >> 21;
 367 
 368         window->dma_addr_lookup.lookup =
 369                 scif_alloc_coherent(&window->dma_addr_lookup.offset,
 370                                     remote_dev, window->nr_lookup *
 371                                     sizeof(*window->dma_addr_lookup.lookup),
 372                                     GFP_KERNEL | __GFP_ZERO);
 373         if (!window->dma_addr_lookup.lookup) {
 374                 err = -ENOMEM;
 375                 goto error_window;
 376         }
 377 
 378         window->num_pages_lookup.lookup =
 379                 scif_alloc_coherent(&window->num_pages_lookup.offset,
 380                                     remote_dev, window->nr_lookup *
 381                                     sizeof(*window->num_pages_lookup.lookup),
 382                                     GFP_KERNEL | __GFP_ZERO);
 383         if (!window->num_pages_lookup.lookup) {
 384                 err = -ENOMEM;
 385                 goto error_window;
 386         }
 387 
 388         vmalloc_dma_phys = is_vmalloc_addr(&window->dma_addr[0]);
 389         vmalloc_num_pages = is_vmalloc_addr(&window->num_pages[0]);
 390 
 391         /* Now map each of the pages containing physical addresses */
 392         for (i = 0, j = 0; i < nr_pages; i += SCIF_NR_ADDR_IN_PAGE, j++) {
 393                 err = scif_map_page(&window->dma_addr_lookup.lookup[j],
 394                                     vmalloc_dma_phys ?
 395                                     vmalloc_to_page(&window->dma_addr[i]) :
 396                                     virt_to_page(&window->dma_addr[i]),
 397                                     remote_dev);
 398                 if (err)
 399                         goto error_window;
 400                 err = scif_map_page(&window->num_pages_lookup.lookup[j],
 401                                     vmalloc_num_pages ?
 402                                     vmalloc_to_page(&window->num_pages[i]) :
 403                                     virt_to_page(&window->num_pages[i]),
 404                                     remote_dev);
 405                 if (err)
 406                         goto error_window;
 407         }
 408         return 0;
 409 error_window:
 410         return err;
 411 }
 412 
 413 /**
 414  * scif_destroy_remote_lookup:
 415  * @remote_dev: SCIF remote device
 416  * @window: remote window
 417  *
 418  * Destroy lookup entries used for the remote
 419  * end to copy over the physical addresses.
 420  */
 421 static void scif_destroy_remote_lookup(struct scif_dev *remote_dev,
 422                                        struct scif_window *window)
 423 {
 424         int i, j;
 425 
 426         if (window->nr_lookup) {
 427                 struct scif_rma_lookup *lup = &window->dma_addr_lookup;
 428                 struct scif_rma_lookup *npup = &window->num_pages_lookup;
 429 
 430                 for (i = 0, j = 0; i < window->nr_pages;
 431                         i += SCIF_NR_ADDR_IN_PAGE, j++) {
 432                         if (lup->lookup && lup->lookup[j])
 433                                 scif_unmap_single(lup->lookup[j],
 434                                                   remote_dev,
 435                                                   PAGE_SIZE);
 436                         if (npup->lookup && npup->lookup[j])
 437                                 scif_unmap_single(npup->lookup[j],
 438                                                   remote_dev,
 439                                                   PAGE_SIZE);
 440                 }
 441                 if (lup->lookup)
 442                         scif_free_coherent(lup->lookup, lup->offset,
 443                                            remote_dev, window->nr_lookup *
 444                                            sizeof(*lup->lookup));
 445                 if (npup->lookup)
 446                         scif_free_coherent(npup->lookup, npup->offset,
 447                                            remote_dev, window->nr_lookup *
 448                                            sizeof(*npup->lookup));
 449                 if (window->mapped_offset)
 450                         scif_unmap_single(window->mapped_offset,
 451                                           remote_dev, sizeof(*window));
 452                 window->nr_lookup = 0;
 453         }
 454 }
 455 
 456 /**
 457  * scif_create_remote_window:
 458  * @ep: end point
 459  * @nr_pages: number of pages in window
 460  *
 461  * Allocate and prepare a remote registration window.
 462  */
 463 static struct scif_window *
 464 scif_create_remote_window(struct scif_dev *scifdev, int nr_pages)
 465 {
 466         struct scif_window *window;
 467 
 468         might_sleep();
 469         window = scif_zalloc(sizeof(*window));
 470         if (!window)
 471                 goto error_ret;
 472 
 473         window->magic = SCIFEP_MAGIC;
 474         window->nr_pages = nr_pages;
 475 
 476         window->dma_addr = scif_zalloc(nr_pages * sizeof(*window->dma_addr));
 477         if (!window->dma_addr)
 478                 goto error_window;
 479 
 480         window->num_pages = scif_zalloc(nr_pages *
 481                                         sizeof(*window->num_pages));
 482         if (!window->num_pages)
 483                 goto error_window;
 484 
 485         if (scif_create_remote_lookup(scifdev, window))
 486                 goto error_window;
 487 
 488         window->type = SCIF_WINDOW_PEER;
 489         window->unreg_state = OP_IDLE;
 490         INIT_LIST_HEAD(&window->list);
 491         return window;
 492 error_window:
 493         scif_destroy_remote_window(window);
 494 error_ret:
 495         return NULL;
 496 }
 497 
 498 /**
 499  * scif_destroy_remote_window:
 500  * @ep: end point
 501  * @window: remote registration window
 502  *
 503  * Deallocate resources for remote window.
 504  */
 505 void
 506 scif_destroy_remote_window(struct scif_window *window)
 507 {
 508         scif_free(window->dma_addr, window->nr_pages *
 509                   sizeof(*window->dma_addr));
 510         scif_free(window->num_pages, window->nr_pages *
 511                   sizeof(*window->num_pages));
 512         window->magic = 0;
 513         scif_free(window, sizeof(*window));
 514 }
 515 
 516 /**
 517  * scif_iommu_map: create DMA mappings if the IOMMU is enabled
 518  * @remote_dev: SCIF remote device
 519  * @window: remote registration window
 520  *
 521  * Map the physical pages using dma_map_sg(..) and then detect the number
 522  * of contiguous DMA mappings allocated
 523  */
 524 static int scif_iommu_map(struct scif_dev *remote_dev,
 525                           struct scif_window *window)
 526 {
 527         struct scatterlist *sg;
 528         int i, err;
 529         scif_pinned_pages_t pin = window->pinned_pages;
 530 
 531         window->st = kzalloc(sizeof(*window->st), GFP_KERNEL);
 532         if (!window->st)
 533                 return -ENOMEM;
 534 
 535         err = sg_alloc_table(window->st, window->nr_pages, GFP_KERNEL);
 536         if (err)
 537                 return err;
 538 
 539         for_each_sg(window->st->sgl, sg, window->st->nents, i)
 540                 sg_set_page(sg, pin->pages[i], PAGE_SIZE, 0x0);
 541 
 542         err = dma_map_sg(&remote_dev->sdev->dev, window->st->sgl,
 543                          window->st->nents, DMA_BIDIRECTIONAL);
 544         if (!err)
 545                 return -ENOMEM;
 546         /* Detect contiguous ranges of DMA mappings */
 547         sg = window->st->sgl;
 548         for (i = 0; sg; i++) {
 549                 dma_addr_t last_da;
 550 
 551                 window->dma_addr[i] = sg_dma_address(sg);
 552                 window->num_pages[i] = sg_dma_len(sg) >> PAGE_SHIFT;
 553                 last_da = sg_dma_address(sg) + sg_dma_len(sg);
 554                 while ((sg = sg_next(sg)) && sg_dma_address(sg) == last_da) {
 555                         window->num_pages[i] +=
 556                                 (sg_dma_len(sg) >> PAGE_SHIFT);
 557                         last_da = window->dma_addr[i] +
 558                                 sg_dma_len(sg);
 559                 }
 560                 window->nr_contig_chunks++;
 561         }
 562         return 0;
 563 }
 564 
 565 /**
 566  * scif_map_window:
 567  * @remote_dev: SCIF remote device
 568  * @window: self registration window
 569  *
 570  * Map pages of a window into the aperture/PCI.
 571  * Also determine addresses required for DMA.
 572  */
 573 int
 574 scif_map_window(struct scif_dev *remote_dev, struct scif_window *window)
 575 {
 576         int i, j, k, err = 0, nr_contig_pages;
 577         scif_pinned_pages_t pin;
 578         phys_addr_t phys_prev, phys_curr;
 579 
 580         might_sleep();
 581 
 582         pin = window->pinned_pages;
 583 
 584         if (intel_iommu_enabled && !scifdev_self(remote_dev))
 585                 return scif_iommu_map(remote_dev, window);
 586 
 587         for (i = 0, j = 0; i < window->nr_pages; i += nr_contig_pages, j++) {
 588                 phys_prev = page_to_phys(pin->pages[i]);
 589                 nr_contig_pages = 1;
 590 
 591                 /* Detect physically contiguous chunks */
 592                 for (k = i + 1; k < window->nr_pages; k++) {
 593                         phys_curr = page_to_phys(pin->pages[k]);
 594                         if (phys_curr != (phys_prev + PAGE_SIZE))
 595                                 break;
 596                         phys_prev = phys_curr;
 597                         nr_contig_pages++;
 598                 }
 599                 window->num_pages[j] = nr_contig_pages;
 600                 window->nr_contig_chunks++;
 601                 if (scif_is_mgmt_node()) {
 602                         /*
 603                          * Management node has to deal with SMPT on X100 and
 604                          * hence the DMA mapping is required
 605                          */
 606                         err = scif_map_single(&window->dma_addr[j],
 607                                               phys_to_virt(page_to_phys(
 608                                                            pin->pages[i])),
 609                                               remote_dev,
 610                                               nr_contig_pages << PAGE_SHIFT);
 611                         if (err)
 612                                 return err;
 613                 } else {
 614                         window->dma_addr[j] = page_to_phys(pin->pages[i]);
 615                 }
 616         }
 617         return err;
 618 }
 619 
 620 /**
 621  * scif_send_scif_unregister:
 622  * @ep: end point
 623  * @window: self registration window
 624  *
 625  * Send a SCIF_UNREGISTER message.
 626  */
 627 static int scif_send_scif_unregister(struct scif_endpt *ep,
 628                                      struct scif_window *window)
 629 {
 630         struct scifmsg msg;
 631 
 632         msg.uop = SCIF_UNREGISTER;
 633         msg.src = ep->port;
 634         msg.payload[0] = window->alloc_handle.vaddr;
 635         msg.payload[1] = (u64)window;
 636         return scif_nodeqp_send(ep->remote_dev, &msg);
 637 }
 638 
 639 /**
 640  * scif_unregister_window:
 641  * @window: self registration window
 642  *
 643  * Send an unregistration request and wait for a response.
 644  */
 645 int scif_unregister_window(struct scif_window *window)
 646 {
 647         int err = 0;
 648         struct scif_endpt *ep = (struct scif_endpt *)window->ep;
 649         bool send_msg = false;
 650 
 651         might_sleep();
 652         switch (window->unreg_state) {
 653         case OP_IDLE:
 654         {
 655                 window->unreg_state = OP_IN_PROGRESS;
 656                 send_msg = true;
 657         }
 658                 /* fall through */
 659         case OP_IN_PROGRESS:
 660         {
 661                 scif_get_window(window, 1);
 662                 mutex_unlock(&ep->rma_info.rma_lock);
 663                 if (send_msg) {
 664                         err = scif_send_scif_unregister(ep, window);
 665                         if (err) {
 666                                 window->unreg_state = OP_COMPLETED;
 667                                 goto done;
 668                         }
 669                 } else {
 670                         /* Return ENXIO since unregistration is in progress */
 671                         mutex_lock(&ep->rma_info.rma_lock);
 672                         return -ENXIO;
 673                 }
 674 retry:
 675                 /* Wait for a SCIF_UNREGISTER_(N)ACK message */
 676                 err = wait_event_timeout(window->unregwq,
 677                                          window->unreg_state != OP_IN_PROGRESS,
 678                                          SCIF_NODE_ALIVE_TIMEOUT);
 679                 if (!err && scifdev_alive(ep))
 680                         goto retry;
 681                 if (!err) {
 682                         err = -ENODEV;
 683                         window->unreg_state = OP_COMPLETED;
 684                         dev_err(scif_info.mdev.this_device,
 685                                 "%s %d err %d\n", __func__, __LINE__, err);
 686                 }
 687                 if (err > 0)
 688                         err = 0;
 689 done:
 690                 mutex_lock(&ep->rma_info.rma_lock);
 691                 scif_put_window(window, 1);
 692                 break;
 693         }
 694         case OP_FAILED:
 695         {
 696                 if (!scifdev_alive(ep)) {
 697                         err = -ENODEV;
 698                         window->unreg_state = OP_COMPLETED;
 699                 }
 700                 break;
 701         }
 702         case OP_COMPLETED:
 703                 break;
 704         default:
 705                 err = -ENODEV;
 706         }
 707 
 708         if (window->unreg_state == OP_COMPLETED && window->ref_count)
 709                 scif_put_window(window, window->nr_pages);
 710 
 711         if (!window->ref_count) {
 712                 atomic_inc(&ep->rma_info.tw_refcount);
 713                 list_del_init(&window->list);
 714                 scif_free_window_offset(ep, window, window->offset);
 715                 mutex_unlock(&ep->rma_info.rma_lock);
 716                 if ((!!(window->pinned_pages->map_flags & SCIF_MAP_KERNEL)) &&
 717                     scifdev_alive(ep)) {
 718                         scif_drain_dma_intr(ep->remote_dev->sdev,
 719                                             ep->rma_info.dma_chan);
 720                 } else {
 721                         if (!__scif_dec_pinned_vm_lock(window->mm,
 722                                                        window->nr_pages)) {
 723                                 __scif_release_mm(window->mm);
 724                                 window->mm = NULL;
 725                         }
 726                 }
 727                 scif_queue_for_cleanup(window, &scif_info.rma);
 728                 mutex_lock(&ep->rma_info.rma_lock);
 729         }
 730         return err;
 731 }
 732 
 733 /**
 734  * scif_send_alloc_request:
 735  * @ep: end point
 736  * @window: self registration window
 737  *
 738  * Send a remote window allocation request
 739  */
 740 static int scif_send_alloc_request(struct scif_endpt *ep,
 741                                    struct scif_window *window)
 742 {
 743         struct scifmsg msg;
 744         struct scif_allocmsg *alloc = &window->alloc_handle;
 745 
 746         /* Set up the Alloc Handle */
 747         alloc->state = OP_IN_PROGRESS;
 748         init_waitqueue_head(&alloc->allocwq);
 749 
 750         /* Send out an allocation request */
 751         msg.uop = SCIF_ALLOC_REQ;
 752         msg.payload[1] = window->nr_pages;
 753         msg.payload[2] = (u64)&window->alloc_handle;
 754         return _scif_nodeqp_send(ep->remote_dev, &msg);
 755 }
 756 
 757 /**
 758  * scif_prep_remote_window:
 759  * @ep: end point
 760  * @window: self registration window
 761  *
 762  * Send a remote window allocation request, wait for an allocation response,
 763  * and prepares the remote window by copying over the page lists
 764  */
 765 static int scif_prep_remote_window(struct scif_endpt *ep,
 766                                    struct scif_window *window)
 767 {
 768         struct scifmsg msg;
 769         struct scif_window *remote_window;
 770         struct scif_allocmsg *alloc = &window->alloc_handle;
 771         dma_addr_t *dma_phys_lookup, *tmp, *num_pages_lookup, *tmp1;
 772         int i = 0, j = 0;
 773         int nr_contig_chunks, loop_nr_contig_chunks;
 774         int remaining_nr_contig_chunks, nr_lookup;
 775         int err, map_err;
 776 
 777         map_err = scif_map_window(ep->remote_dev, window);
 778         if (map_err)
 779                 dev_err(&ep->remote_dev->sdev->dev,
 780                         "%s %d map_err %d\n", __func__, __LINE__, map_err);
 781         remaining_nr_contig_chunks = window->nr_contig_chunks;
 782         nr_contig_chunks = window->nr_contig_chunks;
 783 retry:
 784         /* Wait for a SCIF_ALLOC_GNT/REJ message */
 785         err = wait_event_timeout(alloc->allocwq,
 786                                  alloc->state != OP_IN_PROGRESS,
 787                                  SCIF_NODE_ALIVE_TIMEOUT);
 788         mutex_lock(&ep->rma_info.rma_lock);
 789         /* Synchronize with the thread waking up allocwq */
 790         mutex_unlock(&ep->rma_info.rma_lock);
 791         if (!err && scifdev_alive(ep))
 792                 goto retry;
 793 
 794         if (!err)
 795                 err = -ENODEV;
 796 
 797         if (err > 0)
 798                 err = 0;
 799         else
 800                 return err;
 801 
 802         /* Bail out. The remote end rejected this request */
 803         if (alloc->state == OP_FAILED)
 804                 return -ENOMEM;
 805 
 806         if (map_err) {
 807                 dev_err(&ep->remote_dev->sdev->dev,
 808                         "%s %d err %d\n", __func__, __LINE__, map_err);
 809                 msg.uop = SCIF_FREE_VIRT;
 810                 msg.src = ep->port;
 811                 msg.payload[0] = ep->remote_ep;
 812                 msg.payload[1] = window->alloc_handle.vaddr;
 813                 msg.payload[2] = (u64)window;
 814                 msg.payload[3] = SCIF_REGISTER;
 815                 spin_lock(&ep->lock);
 816                 if (ep->state == SCIFEP_CONNECTED)
 817                         err = _scif_nodeqp_send(ep->remote_dev, &msg);
 818                 else
 819                         err = -ENOTCONN;
 820                 spin_unlock(&ep->lock);
 821                 return err;
 822         }
 823 
 824         remote_window = scif_ioremap(alloc->phys_addr, sizeof(*window),
 825                                      ep->remote_dev);
 826 
 827         /* Compute the number of lookup entries. 21 == 2MB Shift */
 828         nr_lookup = ALIGN(nr_contig_chunks, SCIF_NR_ADDR_IN_PAGE)
 829                           >> ilog2(SCIF_NR_ADDR_IN_PAGE);
 830 
 831         dma_phys_lookup =
 832                 scif_ioremap(remote_window->dma_addr_lookup.offset,
 833                              nr_lookup *
 834                              sizeof(*remote_window->dma_addr_lookup.lookup),
 835                              ep->remote_dev);
 836         num_pages_lookup =
 837                 scif_ioremap(remote_window->num_pages_lookup.offset,
 838                              nr_lookup *
 839                              sizeof(*remote_window->num_pages_lookup.lookup),
 840                              ep->remote_dev);
 841 
 842         while (remaining_nr_contig_chunks) {
 843                 loop_nr_contig_chunks = min_t(int, remaining_nr_contig_chunks,
 844                                               (int)SCIF_NR_ADDR_IN_PAGE);
 845                 /* #1/2 - Copy  physical addresses over to the remote side */
 846 
 847                 /* #2/2 - Copy DMA addresses (addresses that are fed into the
 848                  * DMA engine) We transfer bus addresses which are then
 849                  * converted into a MIC physical address on the remote
 850                  * side if it is a MIC, if the remote node is a mgmt node we
 851                  * transfer the MIC physical address
 852                  */
 853                 tmp = scif_ioremap(dma_phys_lookup[j],
 854                                    loop_nr_contig_chunks *
 855                                    sizeof(*window->dma_addr),
 856                                    ep->remote_dev);
 857                 tmp1 = scif_ioremap(num_pages_lookup[j],
 858                                     loop_nr_contig_chunks *
 859                                     sizeof(*window->num_pages),
 860                                     ep->remote_dev);
 861                 if (scif_is_mgmt_node()) {
 862                         memcpy_toio((void __force __iomem *)tmp,
 863                                     &window->dma_addr[i], loop_nr_contig_chunks
 864                                     * sizeof(*window->dma_addr));
 865                         memcpy_toio((void __force __iomem *)tmp1,
 866                                     &window->num_pages[i], loop_nr_contig_chunks
 867                                     * sizeof(*window->num_pages));
 868                 } else {
 869                         if (scifdev_is_p2p(ep->remote_dev)) {
 870                                 /*
 871                                  * add remote node's base address for this node
 872                                  * to convert it into a MIC address
 873                                  */
 874                                 int m;
 875                                 dma_addr_t dma_addr;
 876 
 877                                 for (m = 0; m < loop_nr_contig_chunks; m++) {
 878                                         dma_addr = window->dma_addr[i + m] +
 879                                                 ep->remote_dev->base_addr;
 880                                         writeq(dma_addr,
 881                                                (void __force __iomem *)&tmp[m]);
 882                                 }
 883                                 memcpy_toio((void __force __iomem *)tmp1,
 884                                             &window->num_pages[i],
 885                                             loop_nr_contig_chunks
 886                                             * sizeof(*window->num_pages));
 887                         } else {
 888                                 /* Mgmt node or loopback - transfer DMA
 889                                  * addresses as is, this is the same as a
 890                                  * MIC physical address (we use the dma_addr
 891                                  * and not the phys_addr array since the
 892                                  * phys_addr is only setup if there is a mmap()
 893                                  * request from the mgmt node)
 894                                  */
 895                                 memcpy_toio((void __force __iomem *)tmp,
 896                                             &window->dma_addr[i],
 897                                             loop_nr_contig_chunks *
 898                                             sizeof(*window->dma_addr));
 899                                 memcpy_toio((void __force __iomem *)tmp1,
 900                                             &window->num_pages[i],
 901                                             loop_nr_contig_chunks *
 902                                             sizeof(*window->num_pages));
 903                         }
 904                 }
 905                 remaining_nr_contig_chunks -= loop_nr_contig_chunks;
 906                 i += loop_nr_contig_chunks;
 907                 j++;
 908                 scif_iounmap(tmp, loop_nr_contig_chunks *
 909                              sizeof(*window->dma_addr), ep->remote_dev);
 910                 scif_iounmap(tmp1, loop_nr_contig_chunks *
 911                              sizeof(*window->num_pages), ep->remote_dev);
 912         }
 913 
 914         /* Prepare the remote window for the peer */
 915         remote_window->peer_window = (u64)window;
 916         remote_window->offset = window->offset;
 917         remote_window->prot = window->prot;
 918         remote_window->nr_contig_chunks = nr_contig_chunks;
 919         remote_window->ep = ep->remote_ep;
 920         scif_iounmap(num_pages_lookup,
 921                      nr_lookup *
 922                      sizeof(*remote_window->num_pages_lookup.lookup),
 923                      ep->remote_dev);
 924         scif_iounmap(dma_phys_lookup,
 925                      nr_lookup *
 926                      sizeof(*remote_window->dma_addr_lookup.lookup),
 927                      ep->remote_dev);
 928         scif_iounmap(remote_window, sizeof(*remote_window), ep->remote_dev);
 929         window->peer_window = alloc->vaddr;
 930         return err;
 931 }
 932 
 933 /**
 934  * scif_send_scif_register:
 935  * @ep: end point
 936  * @window: self registration window
 937  *
 938  * Send a SCIF_REGISTER message if EP is connected and wait for a
 939  * SCIF_REGISTER_(N)ACK message else send a SCIF_FREE_VIRT
 940  * message so that the peer can free its remote window allocated earlier.
 941  */
 942 static int scif_send_scif_register(struct scif_endpt *ep,
 943                                    struct scif_window *window)
 944 {
 945         int err = 0;
 946         struct scifmsg msg;
 947 
 948         msg.src = ep->port;
 949         msg.payload[0] = ep->remote_ep;
 950         msg.payload[1] = window->alloc_handle.vaddr;
 951         msg.payload[2] = (u64)window;
 952         spin_lock(&ep->lock);
 953         if (ep->state == SCIFEP_CONNECTED) {
 954                 msg.uop = SCIF_REGISTER;
 955                 window->reg_state = OP_IN_PROGRESS;
 956                 err = _scif_nodeqp_send(ep->remote_dev, &msg);
 957                 spin_unlock(&ep->lock);
 958                 if (!err) {
 959 retry:
 960                         /* Wait for a SCIF_REGISTER_(N)ACK message */
 961                         err = wait_event_timeout(window->regwq,
 962                                                  window->reg_state !=
 963                                                  OP_IN_PROGRESS,
 964                                                  SCIF_NODE_ALIVE_TIMEOUT);
 965                         if (!err && scifdev_alive(ep))
 966                                 goto retry;
 967                         err = !err ? -ENODEV : 0;
 968                         if (window->reg_state == OP_FAILED)
 969                                 err = -ENOTCONN;
 970                 }
 971         } else {
 972                 msg.uop = SCIF_FREE_VIRT;
 973                 msg.payload[3] = SCIF_REGISTER;
 974                 err = _scif_nodeqp_send(ep->remote_dev, &msg);
 975                 spin_unlock(&ep->lock);
 976                 if (!err)
 977                         err = -ENOTCONN;
 978         }
 979         return err;
 980 }
 981 
 982 /**
 983  * scif_get_window_offset:
 984  * @ep: end point descriptor
 985  * @flags: flags
 986  * @offset: offset hint
 987  * @num_pages: number of pages
 988  * @out_offset: computed offset returned by reference.
 989  *
 990  * Compute/Claim a new offset for this EP.
 991  */
 992 int scif_get_window_offset(struct scif_endpt *ep, int flags, s64 offset,
 993                            int num_pages, s64 *out_offset)
 994 {
 995         s64 page_index;
 996         struct iova *iova_ptr;
 997         int err = 0;
 998 
 999         if (flags & SCIF_MAP_FIXED) {
1000                 page_index = SCIF_IOVA_PFN(offset);
1001                 iova_ptr = reserve_iova(&ep->rma_info.iovad, page_index,
1002                                         page_index + num_pages - 1);
1003                 if (!iova_ptr)
1004                         err = -EADDRINUSE;
1005         } else {
1006                 iova_ptr = alloc_iova(&ep->rma_info.iovad, num_pages,
1007                                       SCIF_DMA_63BIT_PFN - 1, 0);
1008                 if (!iova_ptr)
1009                         err = -ENOMEM;
1010         }
1011         if (!err)
1012                 *out_offset = (iova_ptr->pfn_lo) << PAGE_SHIFT;
1013         return err;
1014 }
1015 
1016 /**
1017  * scif_free_window_offset:
1018  * @ep: end point descriptor
1019  * @window: registration window
1020  * @offset: Offset to be freed
1021  *
1022  * Free offset for this EP. The callee is supposed to grab
1023  * the RMA mutex before calling this API.
1024  */
1025 void scif_free_window_offset(struct scif_endpt *ep,
1026                              struct scif_window *window, s64 offset)
1027 {
1028         if ((window && !window->offset_freed) || !window) {
1029                 free_iova(&ep->rma_info.iovad, offset >> PAGE_SHIFT);
1030                 if (window)
1031                         window->offset_freed = true;
1032         }
1033 }
1034 
1035 /**
1036  * scif_alloc_req: Respond to SCIF_ALLOC_REQ interrupt message
1037  * @msg:        Interrupt message
1038  *
1039  * Remote side is requesting a memory allocation.
1040  */
1041 void scif_alloc_req(struct scif_dev *scifdev, struct scifmsg *msg)
1042 {
1043         int err;
1044         struct scif_window *window = NULL;
1045         int nr_pages = msg->payload[1];
1046 
1047         window = scif_create_remote_window(scifdev, nr_pages);
1048         if (!window) {
1049                 err = -ENOMEM;
1050                 goto error;
1051         }
1052 
1053         /* The peer's allocation request is granted */
1054         msg->uop = SCIF_ALLOC_GNT;
1055         msg->payload[0] = (u64)window;
1056         msg->payload[1] = window->mapped_offset;
1057         err = scif_nodeqp_send(scifdev, msg);
1058         if (err)
1059                 scif_destroy_remote_window(window);
1060         return;
1061 error:
1062         /* The peer's allocation request is rejected */
1063         dev_err(&scifdev->sdev->dev,
1064                 "%s %d error %d alloc_ptr %p nr_pages 0x%x\n",
1065                 __func__, __LINE__, err, window, nr_pages);
1066         msg->uop = SCIF_ALLOC_REJ;
1067         scif_nodeqp_send(scifdev, msg);
1068 }
1069 
1070 /**
1071  * scif_alloc_gnt_rej: Respond to SCIF_ALLOC_GNT/REJ interrupt message
1072  * @msg:        Interrupt message
1073  *
1074  * Remote side responded to a memory allocation.
1075  */
1076 void scif_alloc_gnt_rej(struct scif_dev *scifdev, struct scifmsg *msg)
1077 {
1078         struct scif_allocmsg *handle = (struct scif_allocmsg *)msg->payload[2];
1079         struct scif_window *window = container_of(handle, struct scif_window,
1080                                                   alloc_handle);
1081         struct scif_endpt *ep = (struct scif_endpt *)window->ep;
1082 
1083         mutex_lock(&ep->rma_info.rma_lock);
1084         handle->vaddr = msg->payload[0];
1085         handle->phys_addr = msg->payload[1];
1086         if (msg->uop == SCIF_ALLOC_GNT)
1087                 handle->state = OP_COMPLETED;
1088         else
1089                 handle->state = OP_FAILED;
1090         wake_up(&handle->allocwq);
1091         mutex_unlock(&ep->rma_info.rma_lock);
1092 }
1093 
1094 /**
1095  * scif_free_virt: Respond to SCIF_FREE_VIRT interrupt message
1096  * @msg:        Interrupt message
1097  *
1098  * Free up memory kmalloc'd earlier.
1099  */
1100 void scif_free_virt(struct scif_dev *scifdev, struct scifmsg *msg)
1101 {
1102         struct scif_window *window = (struct scif_window *)msg->payload[1];
1103 
1104         scif_destroy_remote_window(window);
1105 }
1106 
1107 static void
1108 scif_fixup_aper_base(struct scif_dev *dev, struct scif_window *window)
1109 {
1110         int j;
1111         struct scif_hw_dev *sdev = dev->sdev;
1112         phys_addr_t apt_base = 0;
1113 
1114         /*
1115          * Add the aperture base if the DMA address is not card relative
1116          * since the DMA addresses need to be an offset into the bar
1117          */
1118         if (!scifdev_self(dev) && window->type == SCIF_WINDOW_PEER &&
1119             sdev->aper && !sdev->card_rel_da)
1120                 apt_base = sdev->aper->pa;
1121         else
1122                 return;
1123 
1124         for (j = 0; j < window->nr_contig_chunks; j++) {
1125                 if (window->num_pages[j])
1126                         window->dma_addr[j] += apt_base;
1127                 else
1128                         break;
1129         }
1130 }
1131 
1132 /**
1133  * scif_recv_reg: Respond to SCIF_REGISTER interrupt message
1134  * @msg:        Interrupt message
1135  *
1136  * Update remote window list with a new registered window.
1137  */
1138 void scif_recv_reg(struct scif_dev *scifdev, struct scifmsg *msg)
1139 {
1140         struct scif_endpt *ep = (struct scif_endpt *)msg->payload[0];
1141         struct scif_window *window =
1142                 (struct scif_window *)msg->payload[1];
1143 
1144         mutex_lock(&ep->rma_info.rma_lock);
1145         spin_lock(&ep->lock);
1146         if (ep->state == SCIFEP_CONNECTED) {
1147                 msg->uop = SCIF_REGISTER_ACK;
1148                 scif_nodeqp_send(ep->remote_dev, msg);
1149                 scif_fixup_aper_base(ep->remote_dev, window);
1150                 /* No further failures expected. Insert new window */
1151                 scif_insert_window(window, &ep->rma_info.remote_reg_list);
1152         } else {
1153                 msg->uop = SCIF_REGISTER_NACK;
1154                 scif_nodeqp_send(ep->remote_dev, msg);
1155         }
1156         spin_unlock(&ep->lock);
1157         mutex_unlock(&ep->rma_info.rma_lock);
1158         /* free up any lookup resources now that page lists are transferred */
1159         scif_destroy_remote_lookup(ep->remote_dev, window);
1160         /*
1161          * We could not insert the window but we need to
1162          * destroy the window.
1163          */
1164         if (msg->uop == SCIF_REGISTER_NACK)
1165                 scif_destroy_remote_window(window);
1166 }
1167 
1168 /**
1169  * scif_recv_unreg: Respond to SCIF_UNREGISTER interrupt message
1170  * @msg:        Interrupt message
1171  *
1172  * Remove window from remote registration list;
1173  */
1174 void scif_recv_unreg(struct scif_dev *scifdev, struct scifmsg *msg)
1175 {
1176         struct scif_rma_req req;
1177         struct scif_window *window = NULL;
1178         struct scif_window *recv_window =
1179                 (struct scif_window *)msg->payload[0];
1180         struct scif_endpt *ep;
1181         int del_window = 0;
1182 
1183         ep = (struct scif_endpt *)recv_window->ep;
1184         req.out_window = &window;
1185         req.offset = recv_window->offset;
1186         req.prot = 0;
1187         req.nr_bytes = recv_window->nr_pages << PAGE_SHIFT;
1188         req.type = SCIF_WINDOW_FULL;
1189         req.head = &ep->rma_info.remote_reg_list;
1190         msg->payload[0] = ep->remote_ep;
1191 
1192         mutex_lock(&ep->rma_info.rma_lock);
1193         /* Does a valid window exist? */
1194         if (scif_query_window(&req)) {
1195                 dev_err(&scifdev->sdev->dev,
1196                         "%s %d -ENXIO\n", __func__, __LINE__);
1197                 msg->uop = SCIF_UNREGISTER_ACK;
1198                 goto error;
1199         }
1200         if (window) {
1201                 if (window->ref_count)
1202                         scif_put_window(window, window->nr_pages);
1203                 else
1204                         dev_err(&scifdev->sdev->dev,
1205                                 "%s %d ref count should be +ve\n",
1206                                 __func__, __LINE__);
1207                 window->unreg_state = OP_COMPLETED;
1208                 if (!window->ref_count) {
1209                         msg->uop = SCIF_UNREGISTER_ACK;
1210                         atomic_inc(&ep->rma_info.tw_refcount);
1211                         ep->rma_info.async_list_del = 1;
1212                         list_del_init(&window->list);
1213                         del_window = 1;
1214                 } else {
1215                         /* NACK! There are valid references to this window */
1216                         msg->uop = SCIF_UNREGISTER_NACK;
1217                 }
1218         } else {
1219                 /* The window did not make its way to the list at all. ACK */
1220                 msg->uop = SCIF_UNREGISTER_ACK;
1221                 scif_destroy_remote_window(recv_window);
1222         }
1223 error:
1224         mutex_unlock(&ep->rma_info.rma_lock);
1225         if (del_window)
1226                 scif_drain_dma_intr(ep->remote_dev->sdev,
1227                                     ep->rma_info.dma_chan);
1228         scif_nodeqp_send(ep->remote_dev, msg);
1229         if (del_window)
1230                 scif_queue_for_cleanup(window, &scif_info.rma);
1231 }
1232 
1233 /**
1234  * scif_recv_reg_ack: Respond to SCIF_REGISTER_ACK interrupt message
1235  * @msg:        Interrupt message
1236  *
1237  * Wake up the window waiting to complete registration.
1238  */
1239 void scif_recv_reg_ack(struct scif_dev *scifdev, struct scifmsg *msg)
1240 {
1241         struct scif_window *window =
1242                 (struct scif_window *)msg->payload[2];
1243         struct scif_endpt *ep = (struct scif_endpt *)window->ep;
1244 
1245         mutex_lock(&ep->rma_info.rma_lock);
1246         window->reg_state = OP_COMPLETED;
1247         wake_up(&window->regwq);
1248         mutex_unlock(&ep->rma_info.rma_lock);
1249 }
1250 
1251 /**
1252  * scif_recv_reg_nack: Respond to SCIF_REGISTER_NACK interrupt message
1253  * @msg:        Interrupt message
1254  *
1255  * Wake up the window waiting to inform it that registration
1256  * cannot be completed.
1257  */
1258 void scif_recv_reg_nack(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_FAILED;
1266         wake_up(&window->regwq);
1267         mutex_unlock(&ep->rma_info.rma_lock);
1268 }
1269 
1270 /**
1271  * scif_recv_unreg_ack: Respond to SCIF_UNREGISTER_ACK interrupt message
1272  * @msg:        Interrupt message
1273  *
1274  * Wake up the window waiting to complete unregistration.
1275  */
1276 void scif_recv_unreg_ack(struct scif_dev *scifdev, struct scifmsg *msg)
1277 {
1278         struct scif_window *window =
1279                 (struct scif_window *)msg->payload[1];
1280         struct scif_endpt *ep = (struct scif_endpt *)window->ep;
1281 
1282         mutex_lock(&ep->rma_info.rma_lock);
1283         window->unreg_state = OP_COMPLETED;
1284         wake_up(&window->unregwq);
1285         mutex_unlock(&ep->rma_info.rma_lock);
1286 }
1287 
1288 /**
1289  * scif_recv_unreg_nack: Respond to SCIF_UNREGISTER_NACK interrupt message
1290  * @msg:        Interrupt message
1291  *
1292  * Wake up the window waiting to inform it that unregistration
1293  * cannot be completed immediately.
1294  */
1295 void scif_recv_unreg_nack(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_FAILED;
1303         wake_up(&window->unregwq);
1304         mutex_unlock(&ep->rma_info.rma_lock);
1305 }
1306 
1307 int __scif_pin_pages(void *addr, size_t len, int *out_prot,
1308                      int map_flags, scif_pinned_pages_t *pages)
1309 {
1310         struct scif_pinned_pages *pinned_pages;
1311         int nr_pages, err = 0, i;
1312         bool vmalloc_addr = false;
1313         bool try_upgrade = false;
1314         int prot = *out_prot;
1315         int ulimit = 0;
1316         struct mm_struct *mm = NULL;
1317 
1318         /* Unsupported flags */
1319         if (map_flags & ~(SCIF_MAP_KERNEL | SCIF_MAP_ULIMIT))
1320                 return -EINVAL;
1321         ulimit = !!(map_flags & SCIF_MAP_ULIMIT);
1322 
1323         /* Unsupported protection requested */
1324         if (prot & ~(SCIF_PROT_READ | SCIF_PROT_WRITE))
1325                 return -EINVAL;
1326 
1327         /* addr/len must be page aligned. len should be non zero */
1328         if (!len ||
1329             (ALIGN((u64)addr, PAGE_SIZE) != (u64)addr) ||
1330             (ALIGN((u64)len, PAGE_SIZE) != (u64)len))
1331                 return -EINVAL;
1332 
1333         might_sleep();
1334 
1335         nr_pages = len >> PAGE_SHIFT;
1336 
1337         /* Allocate a set of pinned pages */
1338         pinned_pages = scif_create_pinned_pages(nr_pages, prot);
1339         if (!pinned_pages)
1340                 return -ENOMEM;
1341 
1342         if (map_flags & SCIF_MAP_KERNEL) {
1343                 if (is_vmalloc_addr(addr))
1344                         vmalloc_addr = true;
1345 
1346                 for (i = 0; i < nr_pages; i++) {
1347                         if (vmalloc_addr)
1348                                 pinned_pages->pages[i] =
1349                                         vmalloc_to_page(addr + (i * PAGE_SIZE));
1350                         else
1351                                 pinned_pages->pages[i] =
1352                                         virt_to_page(addr + (i * PAGE_SIZE));
1353                 }
1354                 pinned_pages->nr_pages = nr_pages;
1355                 pinned_pages->map_flags = SCIF_MAP_KERNEL;
1356         } else {
1357                 /*
1358                  * SCIF supports registration caching. If a registration has
1359                  * been requested with read only permissions, then we try
1360                  * to pin the pages with RW permissions so that a subsequent
1361                  * transfer with RW permission can hit the cache instead of
1362                  * invalidating it. If the upgrade fails with RW then we
1363                  * revert back to R permission and retry
1364                  */
1365                 if (prot == SCIF_PROT_READ)
1366                         try_upgrade = true;
1367                 prot |= SCIF_PROT_WRITE;
1368 retry:
1369                 mm = current->mm;
1370                 if (ulimit) {
1371                         err = __scif_check_inc_pinned_vm(mm, nr_pages);
1372                         if (err) {
1373                                 pinned_pages->nr_pages = 0;
1374                                 goto error_unmap;
1375                         }
1376                 }
1377 
1378                 pinned_pages->nr_pages = get_user_pages_fast(
1379                                 (u64)addr,
1380                                 nr_pages,
1381                                 (prot & SCIF_PROT_WRITE) ? FOLL_WRITE : 0,
1382                                 pinned_pages->pages);
1383                 if (nr_pages != pinned_pages->nr_pages) {
1384                         if (try_upgrade) {
1385                                 if (ulimit)
1386                                         __scif_dec_pinned_vm_lock(mm, nr_pages);
1387                                 /* Roll back any pinned pages */
1388                                 for (i = 0; i < pinned_pages->nr_pages; i++) {
1389                                         if (pinned_pages->pages[i])
1390                                                 put_page(
1391                                                 pinned_pages->pages[i]);
1392                                 }
1393                                 prot &= ~SCIF_PROT_WRITE;
1394                                 try_upgrade = false;
1395                                 goto retry;
1396                         }
1397                 }
1398                 pinned_pages->map_flags = 0;
1399         }
1400 
1401         if (pinned_pages->nr_pages < nr_pages) {
1402                 err = -EFAULT;
1403                 pinned_pages->nr_pages = nr_pages;
1404                 goto dec_pinned;
1405         }
1406 
1407         *out_prot = prot;
1408         atomic_set(&pinned_pages->ref_count, 1);
1409         *pages = pinned_pages;
1410         return err;
1411 dec_pinned:
1412         if (ulimit)
1413                 __scif_dec_pinned_vm_lock(mm, nr_pages);
1414         /* Something went wrong! Rollback */
1415 error_unmap:
1416         pinned_pages->nr_pages = nr_pages;
1417         scif_destroy_pinned_pages(pinned_pages);
1418         *pages = NULL;
1419         dev_dbg(scif_info.mdev.this_device,
1420                 "%s %d err %d len 0x%lx\n", __func__, __LINE__, err, len);
1421         return err;
1422 }
1423 
1424 int scif_pin_pages(void *addr, size_t len, int prot,
1425                    int map_flags, scif_pinned_pages_t *pages)
1426 {
1427         return __scif_pin_pages(addr, len, &prot, map_flags, pages);
1428 }
1429 EXPORT_SYMBOL_GPL(scif_pin_pages);
1430 
1431 int scif_unpin_pages(scif_pinned_pages_t pinned_pages)
1432 {
1433         int err = 0, ret;
1434 
1435         if (!pinned_pages || SCIFEP_MAGIC != pinned_pages->magic)
1436                 return -EINVAL;
1437 
1438         ret = atomic_sub_return(1, &pinned_pages->ref_count);
1439         if (ret < 0) {
1440                 dev_err(scif_info.mdev.this_device,
1441                         "%s %d scif_unpin_pages called without pinning? rc %d\n",
1442                         __func__, __LINE__, ret);
1443                 return -EINVAL;
1444         }
1445         /*
1446          * Destroy the window if the ref count for this set of pinned
1447          * pages has dropped to zero. If it is positive then there is
1448          * a valid registered window which is backed by these pages and
1449          * it will be destroyed once all such windows are unregistered.
1450          */
1451         if (!ret)
1452                 err = scif_destroy_pinned_pages(pinned_pages);
1453 
1454         return err;
1455 }
1456 EXPORT_SYMBOL_GPL(scif_unpin_pages);
1457 
1458 static inline void
1459 scif_insert_local_window(struct scif_window *window, struct scif_endpt *ep)
1460 {
1461         mutex_lock(&ep->rma_info.rma_lock);
1462         scif_insert_window(window, &ep->rma_info.reg_list);
1463         mutex_unlock(&ep->rma_info.rma_lock);
1464 }
1465 
1466 off_t scif_register_pinned_pages(scif_epd_t epd,
1467                                  scif_pinned_pages_t pinned_pages,
1468                                  off_t offset, int map_flags)
1469 {
1470         struct scif_endpt *ep = (struct scif_endpt *)epd;
1471         s64 computed_offset;
1472         struct scif_window *window;
1473         int err;
1474         size_t len;
1475         struct device *spdev;
1476 
1477         /* Unsupported flags */
1478         if (map_flags & ~SCIF_MAP_FIXED)
1479                 return -EINVAL;
1480 
1481         len = pinned_pages->nr_pages << PAGE_SHIFT;
1482 
1483         /*
1484          * Offset is not page aligned/negative or offset+len
1485          * wraps around with SCIF_MAP_FIXED.
1486          */
1487         if ((map_flags & SCIF_MAP_FIXED) &&
1488             ((ALIGN(offset, PAGE_SIZE) != offset) ||
1489             (offset < 0) ||
1490             (len > LONG_MAX - offset)))
1491                 return -EINVAL;
1492 
1493         might_sleep();
1494 
1495         err = scif_verify_epd(ep);
1496         if (err)
1497                 return err;
1498         /*
1499          * It is an error to pass pinned_pages to scif_register_pinned_pages()
1500          * after calling scif_unpin_pages().
1501          */
1502         if (!atomic_add_unless(&pinned_pages->ref_count, 1, 0))
1503                 return -EINVAL;
1504 
1505         /* Compute the offset for this registration */
1506         err = scif_get_window_offset(ep, map_flags, offset,
1507                                      len, &computed_offset);
1508         if (err) {
1509                 atomic_sub(1, &pinned_pages->ref_count);
1510                 return err;
1511         }
1512 
1513         /* Allocate and prepare self registration window */
1514         window = scif_create_window(ep, pinned_pages->nr_pages,
1515                                     computed_offset, false);
1516         if (!window) {
1517                 atomic_sub(1, &pinned_pages->ref_count);
1518                 scif_free_window_offset(ep, NULL, computed_offset);
1519                 return -ENOMEM;
1520         }
1521 
1522         window->pinned_pages = pinned_pages;
1523         window->nr_pages = pinned_pages->nr_pages;
1524         window->prot = pinned_pages->prot;
1525 
1526         spdev = scif_get_peer_dev(ep->remote_dev);
1527         if (IS_ERR(spdev)) {
1528                 err = PTR_ERR(spdev);
1529                 scif_destroy_window(ep, window);
1530                 return err;
1531         }
1532         err = scif_send_alloc_request(ep, window);
1533         if (err) {
1534                 dev_err(&ep->remote_dev->sdev->dev,
1535                         "%s %d err %d\n", __func__, __LINE__, err);
1536                 goto error_unmap;
1537         }
1538 
1539         /* Prepare the remote registration window */
1540         err = scif_prep_remote_window(ep, window);
1541         if (err) {
1542                 dev_err(&ep->remote_dev->sdev->dev,
1543                         "%s %d err %d\n", __func__, __LINE__, err);
1544                 goto error_unmap;
1545         }
1546 
1547         /* Tell the peer about the new window */
1548         err = scif_send_scif_register(ep, window);
1549         if (err) {
1550                 dev_err(&ep->remote_dev->sdev->dev,
1551                         "%s %d err %d\n", __func__, __LINE__, err);
1552                 goto error_unmap;
1553         }
1554 
1555         scif_put_peer_dev(spdev);
1556         /* No further failures expected. Insert new window */
1557         scif_insert_local_window(window, ep);
1558         return computed_offset;
1559 error_unmap:
1560         scif_destroy_window(ep, window);
1561         scif_put_peer_dev(spdev);
1562         dev_err(&ep->remote_dev->sdev->dev,
1563                 "%s %d err %d\n", __func__, __LINE__, err);
1564         return err;
1565 }
1566 EXPORT_SYMBOL_GPL(scif_register_pinned_pages);
1567 
1568 off_t scif_register(scif_epd_t epd, void *addr, size_t len, off_t offset,
1569                     int prot, int map_flags)
1570 {
1571         scif_pinned_pages_t pinned_pages;
1572         off_t err;
1573         struct scif_endpt *ep = (struct scif_endpt *)epd;
1574         s64 computed_offset;
1575         struct scif_window *window;
1576         struct mm_struct *mm = NULL;
1577         struct device *spdev;
1578 
1579         dev_dbg(scif_info.mdev.this_device,
1580                 "SCIFAPI register: ep %p addr %p len 0x%lx offset 0x%lx prot 0x%x map_flags 0x%x\n",
1581                 epd, addr, len, offset, prot, map_flags);
1582         /* Unsupported flags */
1583         if (map_flags & ~(SCIF_MAP_FIXED | SCIF_MAP_KERNEL))
1584                 return -EINVAL;
1585 
1586         /*
1587          * Offset is not page aligned/negative or offset+len
1588          * wraps around with SCIF_MAP_FIXED.
1589          */
1590         if ((map_flags & SCIF_MAP_FIXED) &&
1591             ((ALIGN(offset, PAGE_SIZE) != offset) ||
1592             (offset < 0) ||
1593             (len > LONG_MAX - offset)))
1594                 return -EINVAL;
1595 
1596         /* Unsupported protection requested */
1597         if (prot & ~(SCIF_PROT_READ | SCIF_PROT_WRITE))
1598                 return -EINVAL;
1599 
1600         /* addr/len must be page aligned. len should be non zero */
1601         if (!len || (ALIGN((u64)addr, PAGE_SIZE) != (u64)addr) ||
1602             (ALIGN(len, PAGE_SIZE) != len))
1603                 return -EINVAL;
1604 
1605         might_sleep();
1606 
1607         err = scif_verify_epd(ep);
1608         if (err)
1609                 return err;
1610 
1611         /* Compute the offset for this registration */
1612         err = scif_get_window_offset(ep, map_flags, offset,
1613                                      len >> PAGE_SHIFT, &computed_offset);
1614         if (err)
1615                 return err;
1616 
1617         spdev = scif_get_peer_dev(ep->remote_dev);
1618         if (IS_ERR(spdev)) {
1619                 err = PTR_ERR(spdev);
1620                 scif_free_window_offset(ep, NULL, computed_offset);
1621                 return err;
1622         }
1623         /* Allocate and prepare self registration window */
1624         window = scif_create_window(ep, len >> PAGE_SHIFT,
1625                                     computed_offset, false);
1626         if (!window) {
1627                 scif_free_window_offset(ep, NULL, computed_offset);
1628                 scif_put_peer_dev(spdev);
1629                 return -ENOMEM;
1630         }
1631 
1632         window->nr_pages = len >> PAGE_SHIFT;
1633 
1634         err = scif_send_alloc_request(ep, window);
1635         if (err) {
1636                 scif_destroy_incomplete_window(ep, window);
1637                 scif_put_peer_dev(spdev);
1638                 return err;
1639         }
1640 
1641         if (!(map_flags & SCIF_MAP_KERNEL)) {
1642                 mm = __scif_acquire_mm();
1643                 map_flags |= SCIF_MAP_ULIMIT;
1644         }
1645         /* Pin down the pages */
1646         err = __scif_pin_pages(addr, len, &prot,
1647                                map_flags & (SCIF_MAP_KERNEL | SCIF_MAP_ULIMIT),
1648                                &pinned_pages);
1649         if (err) {
1650                 scif_destroy_incomplete_window(ep, window);
1651                 __scif_release_mm(mm);
1652                 goto error;
1653         }
1654 
1655         window->pinned_pages = pinned_pages;
1656         window->prot = pinned_pages->prot;
1657         window->mm = mm;
1658 
1659         /* Prepare the remote registration window */
1660         err = scif_prep_remote_window(ep, window);
1661         if (err) {
1662                 dev_err(&ep->remote_dev->sdev->dev,
1663                         "%s %d err %ld\n", __func__, __LINE__, err);
1664                 goto error_unmap;
1665         }
1666 
1667         /* Tell the peer about the new window */
1668         err = scif_send_scif_register(ep, window);
1669         if (err) {
1670                 dev_err(&ep->remote_dev->sdev->dev,
1671                         "%s %d err %ld\n", __func__, __LINE__, err);
1672                 goto error_unmap;
1673         }
1674 
1675         scif_put_peer_dev(spdev);
1676         /* No further failures expected. Insert new window */
1677         scif_insert_local_window(window, ep);
1678         dev_dbg(&ep->remote_dev->sdev->dev,
1679                 "SCIFAPI register: ep %p addr %p len 0x%lx computed_offset 0x%llx\n",
1680                 epd, addr, len, computed_offset);
1681         return computed_offset;
1682 error_unmap:
1683         scif_destroy_window(ep, window);
1684 error:
1685         scif_put_peer_dev(spdev);
1686         dev_err(&ep->remote_dev->sdev->dev,
1687                 "%s %d err %ld\n", __func__, __LINE__, err);
1688         return err;
1689 }
1690 EXPORT_SYMBOL_GPL(scif_register);
1691 
1692 int
1693 scif_unregister(scif_epd_t epd, off_t offset, size_t len)
1694 {
1695         struct scif_endpt *ep = (struct scif_endpt *)epd;
1696         struct scif_window *window = NULL;
1697         struct scif_rma_req req;
1698         int nr_pages, err;
1699         struct device *spdev;
1700 
1701         dev_dbg(scif_info.mdev.this_device,
1702                 "SCIFAPI unregister: ep %p offset 0x%lx len 0x%lx\n",
1703                 ep, offset, len);
1704         /* len must be page aligned. len should be non zero */
1705         if (!len ||
1706             (ALIGN((u64)len, PAGE_SIZE) != (u64)len))
1707                 return -EINVAL;
1708 
1709         /* Offset is not page aligned or offset+len wraps around */
1710         if ((ALIGN(offset, PAGE_SIZE) != offset) ||
1711             (offset < 0) ||
1712             (len > LONG_MAX - offset))
1713                 return -EINVAL;
1714 
1715         err = scif_verify_epd(ep);
1716         if (err)
1717                 return err;
1718 
1719         might_sleep();
1720         nr_pages = len >> PAGE_SHIFT;
1721 
1722         req.out_window = &window;
1723         req.offset = offset;
1724         req.prot = 0;
1725         req.nr_bytes = len;
1726         req.type = SCIF_WINDOW_FULL;
1727         req.head = &ep->rma_info.reg_list;
1728 
1729         spdev = scif_get_peer_dev(ep->remote_dev);
1730         if (IS_ERR(spdev)) {
1731                 err = PTR_ERR(spdev);
1732                 return err;
1733         }
1734         mutex_lock(&ep->rma_info.rma_lock);
1735         /* Does a valid window exist? */
1736         err = scif_query_window(&req);
1737         if (err) {
1738                 dev_err(&ep->remote_dev->sdev->dev,
1739                         "%s %d err %d\n", __func__, __LINE__, err);
1740                 goto error;
1741         }
1742         /* Unregister all the windows in this range */
1743         err = scif_rma_list_unregister(window, offset, nr_pages);
1744         if (err)
1745                 dev_err(&ep->remote_dev->sdev->dev,
1746                         "%s %d err %d\n", __func__, __LINE__, err);
1747 error:
1748         mutex_unlock(&ep->rma_info.rma_lock);
1749         scif_put_peer_dev(spdev);
1750         return err;
1751 }
1752 EXPORT_SYMBOL_GPL(scif_unregister);
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/misc/mic/scif/scif_rma.c

DEFINITIONS
