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