drivers/infiniband/hw/usnic/usnic_uiom.c

   1 /*
   2  * Copyright (c) 2005 Topspin Communications.  All rights reserved.
   3  * Copyright (c) 2005 Mellanox Technologies. All rights reserved.
   4  * Copyright (c) 2013 Cisco Systems.  All rights reserved.
   5  *
   6  * This software is available to you under a choice of one of two
   7  * licenses.  You may choose to be licensed under the terms of the GNU
   8  * General Public License (GPL) Version 2, available from the file
   9  * COPYING in the main directory of this source tree, or the
  10  * BSD license below:
  11  *
  12  *     Redistribution and use in source and binary forms, with or
  13  *     without modification, are permitted provided that the following
  14  *     conditions are met:
  15  *
  16  *      - Redistributions of source code must retain the above
  17  *        copyright notice, this list of conditions and the following
  18  *        disclaimer.
  19  *
  20  *      - Redistributions in binary form must reproduce the above
  21  *        copyright notice, this list of conditions and the following
  22  *        disclaimer in the documentation and/or other materials
  23  *        provided with the distribution.
  24  *
  25  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  26  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  27  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  28  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  29  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  30  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  31  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  32  * SOFTWARE.
  33  */
  34
  35 #include <linux/mm.h>
  36 #include <linux/dma-mapping.h>
  37 #include <linux/sched.h>
  38 #include <linux/hugetlb.h>
  39 #include <linux/iommu.h>
  40 #include <linux/workqueue.h>
  41 #include <linux/list.h>
  42 #include <linux/pci.h>
  43
  44 #include "usnic_log.h"
  45 #include "usnic_uiom.h"
  46 #include "usnic_uiom_interval_tree.h"
  47
  48 static struct workqueue_struct *usnic_uiom_wq;
  49
  50 #define USNIC_UIOM_PAGE_CHUNK                                           \
  51         ((PAGE_SIZE - offsetof(struct usnic_uiom_chunk, page_list))     /\
  52         ((void *) &((struct usnic_uiom_chunk *) 0)->page_list[1] -      \
  53         (void *) &((struct usnic_uiom_chunk *) 0)->page_list[0]))
  54
  55 static void usnic_uiom_reg_account(struct work_struct *work)
  56 {
  57         struct usnic_uiom_reg *umem = container_of(work,
  58                                                 struct usnic_uiom_reg, work);
  59
  60         down_write(&umem->mm->mmap_sem);
  61         umem->mm->locked_vm -= umem->diff;
  62         up_write(&umem->mm->mmap_sem);
  63         mmput(umem->mm);
  64         kfree(umem);
  65 }
  66
  67 static int usnic_uiom_dma_fault(struct iommu_domain *domain,
  68                                 struct device *dev,
  69                                 unsigned long iova, int flags,
  70                                 void *token)
  71 {
  72         usnic_err("Device %s iommu fault domain 0x%pK va 0x%lx flags 0x%x\n",
  73                 dev_name(dev),
  74                 domain, iova, flags);
  75         return -ENOSYS;
  76 }
  77
  78 static void usnic_uiom_put_pages(struct list_head *chunk_list, int dirty)
  79 {
  80         struct usnic_uiom_chunk *chunk, *tmp;
  81         struct page *page;
  82         struct scatterlist *sg;
  83         int i;
  84         dma_addr_t pa;
  85
  86         list_for_each_entry_safe(chunk, tmp, chunk_list, list) {
  87                 for_each_sg(chunk->page_list, sg, chunk->nents, i) {
  88                         page = sg_page(sg);
  89                         pa = sg_phys(sg);
  90                         if (dirty)
  91                                 set_page_dirty_lock(page);
  92                         put_page(page);
  93                         usnic_dbg("pa: %pa\n", &pa);
  94                 }
  95                 kfree(chunk);
  96         }
  97 }
  98
  99 static int usnic_uiom_get_pages(unsigned long addr, size_t size, int writable,
 100                                 int dmasync, struct list_head *chunk_list)
 101 {
 102         struct page **page_list;
 103         struct scatterlist *sg;
 104         struct usnic_uiom_chunk *chunk;
 105         unsigned long locked;
 106         unsigned long lock_limit;
 107         unsigned long cur_base;
 108         unsigned long npages;
 109         int ret;
 110         int off;
 111         int i;
 112         int flags;
 113         dma_addr_t pa;
 114
 115         if (!can_do_mlock())
 116                 return -EPERM;
 117
 118         INIT_LIST_HEAD(chunk_list);
 119
 120         page_list = (struct page **) __get_free_page(GFP_KERNEL);
 121         if (!page_list)
 122                 return -ENOMEM;
 123
 124         npages = PAGE_ALIGN(size + (addr & ~PAGE_MASK)) >> PAGE_SHIFT;
 125
 126         down_write(&current->mm->mmap_sem);
 127
 128         locked = npages + current->mm->locked_vm;
 129         lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
 130
 131         if ((locked > lock_limit) && !capable(CAP_IPC_LOCK)) {
 132                 ret = -ENOMEM;
 133                 goto out;
 134         }
 135
 136         flags = IOMMU_READ | IOMMU_CACHE;
 137         flags |= (writable) ? IOMMU_WRITE : 0;
 138         cur_base = addr & PAGE_MASK;
 139         ret = 0;
 140
 141         while (npages) {
 142                 ret = get_user_pages(cur_base,
 143                                         min_t(unsigned long, npages,
 144                                         PAGE_SIZE / sizeof(struct page *)),
 145                                         1, !writable, page_list, NULL);
 146
 147                 if (ret < 0)
 148                         goto out;
 149
 150                 npages -= ret;
 151                 off = 0;
 152
 153                 while (ret) {
 154                         chunk = kmalloc(sizeof(*chunk) +
 155                                         sizeof(struct scatterlist) *
 156                                         min_t(int, ret, USNIC_UIOM_PAGE_CHUNK),
 157                                         GFP_KERNEL);
 158                         if (!chunk) {
 159                                 ret = -ENOMEM;
 160                                 goto out;
 161                         }
 162
 163                         chunk->nents = min_t(int, ret, USNIC_UIOM_PAGE_CHUNK);
 164                         sg_init_table(chunk->page_list, chunk->nents);
 165                         for_each_sg(chunk->page_list, sg, chunk->nents, i) {
 166                                 sg_set_page(sg, page_list[i + off],
 167                                                 PAGE_SIZE, 0);
 168                                 pa = sg_phys(sg);
 169                                 usnic_dbg("va: 0x%lx pa: %pa\n",
 170                                                 cur_base + i*PAGE_SIZE, &pa);
 171                         }
 172                         cur_base += chunk->nents * PAGE_SIZE;
 173                         ret -= chunk->nents;
 174                         off += chunk->nents;
 175                         list_add_tail(&chunk->list, chunk_list);
 176                 }
 177
 178                 ret = 0;
 179         }
 180
 181 out:
 182         if (ret < 0)
 183                 usnic_uiom_put_pages(chunk_list, 0);
 184         else
 185                 current->mm->locked_vm = locked;
 186
 187         up_write(&current->mm->mmap_sem);
 188         free_page((unsigned long) page_list);
 189         return ret;
 190 }
 191
 192 static void usnic_uiom_unmap_sorted_intervals(struct list_head *intervals,
 193                                                 struct usnic_uiom_pd *pd)
 194 {
 195         struct usnic_uiom_interval_node *interval, *tmp;
 196         long unsigned va, size;
 197
 198         list_for_each_entry_safe(interval, tmp, intervals, link) {
 199                 va = interval->start << PAGE_SHIFT;
 200                 size = ((interval->last - interval->start) + 1) << PAGE_SHIFT;
 201                 while (size > 0) {
 202                         /* Workaround for RH 970401 */
 203                         usnic_dbg("va 0x%lx size 0x%lx", va, PAGE_SIZE);
 204                         iommu_unmap(pd->domain, va, PAGE_SIZE);
 205                         va += PAGE_SIZE;
 206                         size -= PAGE_SIZE;
 207                 }
 208         }
 209 }
 210
 211 static void __usnic_uiom_reg_release(struct usnic_uiom_pd *pd,
 212                                         struct usnic_uiom_reg *uiomr,
 213                                         int dirty)
 214 {
 215         int npages;
 216         unsigned long vpn_start, vpn_last;
 217         struct usnic_uiom_interval_node *interval, *tmp;
 218         int writable = 0;
 219         LIST_HEAD(rm_intervals);
 220
 221         npages = PAGE_ALIGN(uiomr->length + uiomr->offset) >> PAGE_SHIFT;
 222         vpn_start = (uiomr->va & PAGE_MASK) >> PAGE_SHIFT;
 223         vpn_last = vpn_start + npages - 1;
 224
 225         spin_lock(&pd->lock);
 226         usnic_uiom_remove_interval(&pd->rb_root, vpn_start,
 227                                         vpn_last, &rm_intervals);
 228         usnic_uiom_unmap_sorted_intervals(&rm_intervals, pd);
 229
 230         list_for_each_entry_safe(interval, tmp, &rm_intervals, link) {
 231                 if (interval->flags & IOMMU_WRITE)
 232                         writable = 1;
 233                 list_del(&interval->link);
 234                 kfree(interval);
 235         }
 236
 237         usnic_uiom_put_pages(&uiomr->chunk_list, dirty & writable);
 238         spin_unlock(&pd->lock);
 239 }
 240
 241 static int usnic_uiom_map_sorted_intervals(struct list_head *intervals,
 242                                                 struct usnic_uiom_reg *uiomr)
 243 {
 244         int i, err;
 245         size_t size;
 246         struct usnic_uiom_chunk *chunk;
 247         struct usnic_uiom_interval_node *interval_node;
 248         dma_addr_t pa;
 249         dma_addr_t pa_start = 0;
 250         dma_addr_t pa_end = 0;
 251         long int va_start = -EINVAL;
 252         struct usnic_uiom_pd *pd = uiomr->pd;
 253         long int va = uiomr->va & PAGE_MASK;
 254         int flags = IOMMU_READ | IOMMU_CACHE;
 255
 256         flags |= (uiomr->writable) ? IOMMU_WRITE : 0;
 257         chunk = list_first_entry(&uiomr->chunk_list, struct usnic_uiom_chunk,
 258                                                                         list);
 259         list_for_each_entry(interval_node, intervals, link) {
 260 iter_chunk:
 261                 for (i = 0; i < chunk->nents; i++, va += PAGE_SIZE) {
 262                         pa = sg_phys(&chunk->page_list[i]);
 263                         if ((va >> PAGE_SHIFT) < interval_node->start)
 264                                 continue;
 265
 266                         if ((va >> PAGE_SHIFT) == interval_node->start) {
 267                                 /* First page of the interval */
 268                                 va_start = va;
 269                                 pa_start = pa;
 270                                 pa_end = pa;
 271                         }
 272
 273                         WARN_ON(va_start == -EINVAL);
 274
 275                         if ((pa_end + PAGE_SIZE != pa) &&
 276                                         (pa != pa_start)) {
 277                                 /* PAs are not contiguous */
 278                                 size = pa_end - pa_start + PAGE_SIZE;
 279                                 usnic_dbg("va 0x%lx pa %pa size 0x%zx flags 0x%x",
 280                                         va_start, &pa_start, size, flags);
 281                                 err = iommu_map(pd->domain, va_start, pa_start,
 282                                                         size, flags);
 283                                 if (err) {
 284                                         usnic_err("Failed to map va 0x%lx pa %pa size 0x%zx with err %d\n",
 285                                                 va_start, &pa_start, size, err);
 286                                         goto err_out;
 287                                 }
 288                                 va_start = va;
 289                                 pa_start = pa;
 290                                 pa_end = pa;
 291                         }
 292
 293                         if ((va >> PAGE_SHIFT) == interval_node->last) {
 294                                 /* Last page of the interval */
 295                                 size = pa - pa_start + PAGE_SIZE;
 296                                 usnic_dbg("va 0x%lx pa %pa size 0x%zx flags 0x%x\n",
 297                                         va_start, &pa_start, size, flags);
 298                                 err = iommu_map(pd->domain, va_start, pa_start,
 299                                                 size, flags);
 300                                 if (err) {
 301                                         usnic_err("Failed to map va 0x%lx pa %pa size 0x%zx with err %d\n",
 302                                                 va_start, &pa_start, size, err);
 303                                         goto err_out;
 304                                 }
 305                                 break;
 306                         }
 307
 308                         if (pa != pa_start)
 309                                 pa_end += PAGE_SIZE;
 310                 }
 311
 312                 if (i == chunk->nents) {
 313                         /*
 314                          * Hit last entry of the chunk,
 315                          * hence advance to next chunk
 316                          */
 317                         chunk = list_first_entry(&chunk->list,
 318                                                         struct usnic_uiom_chunk,
 319                                                         list);
 320                         goto iter_chunk;
 321                 }
 322         }
 323
 324         return 0;
 325
 326 err_out:
 327         usnic_uiom_unmap_sorted_intervals(intervals, pd);
 328         return err;
 329 }
 330
 331 struct usnic_uiom_reg *usnic_uiom_reg_get(struct usnic_uiom_pd *pd,
 332                                                 unsigned long addr, size_t size,
 333                                                 int writable, int dmasync)
 334 {
 335         struct usnic_uiom_reg *uiomr;
 336         unsigned long va_base, vpn_start, vpn_last;
 337         unsigned long npages;
 338         int offset, err;
 339         LIST_HEAD(sorted_diff_intervals);
 340
 341         /*
 342          * Intel IOMMU map throws an error if a translation entry is
 343          * changed from read to write.  This module may not unmap
 344          * and then remap the entry after fixing the permission
 345          * b/c this open up a small windows where hw DMA may page fault
 346          * Hence, make all entries to be writable.
 347          */
 348         writable = 1;
 349
 350         va_base = addr & PAGE_MASK;
 351         offset = addr & ~PAGE_MASK;
 352         npages = PAGE_ALIGN(size + offset) >> PAGE_SHIFT;
 353         vpn_start = (addr & PAGE_MASK) >> PAGE_SHIFT;
 354         vpn_last = vpn_start + npages - 1;
 355
 356         uiomr = kmalloc(sizeof(*uiomr), GFP_KERNEL);
 357         if (!uiomr)
 358                 return ERR_PTR(-ENOMEM);
 359
 360         uiomr->va = va_base;
 361         uiomr->offset = offset;
 362         uiomr->length = size;
 363         uiomr->writable = writable;
 364         uiomr->pd = pd;
 365
 366         err = usnic_uiom_get_pages(addr, size, writable, dmasync,
 367                                         &uiomr->chunk_list);
 368         if (err) {
 369                 usnic_err("Failed get_pages vpn [0x%lx,0x%lx] err %d\n",
 370                                 vpn_start, vpn_last, err);
 371                 goto out_free_uiomr;
 372         }
 373
 374         spin_lock(&pd->lock);
 375         err = usnic_uiom_get_intervals_diff(vpn_start, vpn_last,
 376                                                 (writable) ? IOMMU_WRITE : 0,
 377                                                 IOMMU_WRITE,
 378                                                 &pd->rb_root,
 379                                                 &sorted_diff_intervals);
 380         if (err) {
 381                 usnic_err("Failed disjoint interval vpn [0x%lx,0x%lx] err %d\n",
 382                                                 vpn_start, vpn_last, err);
 383                 goto out_put_pages;
 384         }
 385
 386         err = usnic_uiom_map_sorted_intervals(&sorted_diff_intervals, uiomr);
 387         if (err) {
 388                 usnic_err("Failed map interval vpn [0x%lx,0x%lx] err %d\n",
 389                                                 vpn_start, vpn_last, err);
 390                 goto out_put_intervals;
 391
 392         }
 393
 394         err = usnic_uiom_insert_interval(&pd->rb_root, vpn_start, vpn_last,
 395                                         (writable) ? IOMMU_WRITE : 0);
 396         if (err) {
 397                 usnic_err("Failed insert interval vpn [0x%lx,0x%lx] err %d\n",
 398                                                 vpn_start, vpn_last, err);
 399                 goto out_unmap_intervals;
 400         }
 401
 402         usnic_uiom_put_interval_set(&sorted_diff_intervals);
 403         spin_unlock(&pd->lock);
 404
 405         return uiomr;
 406
 407 out_unmap_intervals:
 408         usnic_uiom_unmap_sorted_intervals(&sorted_diff_intervals, pd);
 409 out_put_intervals:
 410         usnic_uiom_put_interval_set(&sorted_diff_intervals);
 411 out_put_pages:
 412         usnic_uiom_put_pages(&uiomr->chunk_list, 0);
 413         spin_unlock(&pd->lock);
 414 out_free_uiomr:
 415         kfree(uiomr);
 416         return ERR_PTR(err);
 417 }
 418
 419 void usnic_uiom_reg_release(struct usnic_uiom_reg *uiomr, int closing)
 420 {
 421         struct mm_struct *mm;
 422         unsigned long diff;
 423
 424         __usnic_uiom_reg_release(uiomr->pd, uiomr, 1);
 425
 426         mm = get_task_mm(current);
 427         if (!mm) {
 428                 kfree(uiomr);
 429                 return;
 430         }
 431
 432         diff = PAGE_ALIGN(uiomr->length + uiomr->offset) >> PAGE_SHIFT;
 433
 434         /*
 435          * We may be called with the mm's mmap_sem already held.  This
 436          * can happen when a userspace munmap() is the call that drops
 437          * the last reference to our file and calls our release
 438          * method.  If there are memory regions to destroy, we'll end
 439          * up here and not be able to take the mmap_sem.  In that case
 440          * we defer the vm_locked accounting to the system workqueue.
 441          */
 442         if (closing) {
 443                 if (!down_write_trylock(&mm->mmap_sem)) {
 444                         INIT_WORK(&uiomr->work, usnic_uiom_reg_account);
 445                         uiomr->mm = mm;
 446                         uiomr->diff = diff;
 447
 448                         queue_work(usnic_uiom_wq, &uiomr->work);
 449                         return;
 450                 }
 451         } else
 452                 down_write(&mm->mmap_sem);
 453
 454         current->mm->locked_vm -= diff;
 455         up_write(&mm->mmap_sem);
 456         mmput(mm);
 457         kfree(uiomr);
 458 }
 459
 460 struct usnic_uiom_pd *usnic_uiom_alloc_pd(void)
 461 {
 462         struct usnic_uiom_pd *pd;
 463         void *domain;
 464
 465         pd = kzalloc(sizeof(*pd), GFP_KERNEL);
 466         if (!pd)
 467                 return ERR_PTR(-ENOMEM);
 468
 469         pd->domain = domain = iommu_domain_alloc(&pci_bus_type);
 470         if (!domain) {
 471                 usnic_err("Failed to allocate IOMMU domain");
 472                 kfree(pd);
 473                 return ERR_PTR(-ENOMEM);
 474         }
 475
 476         iommu_set_fault_handler(pd->domain, usnic_uiom_dma_fault, NULL);
 477
 478         spin_lock_init(&pd->lock);
 479         INIT_LIST_HEAD(&pd->devs);
 480
 481         return pd;
 482 }
 483
 484 void usnic_uiom_dealloc_pd(struct usnic_uiom_pd *pd)
 485 {
 486         iommu_domain_free(pd->domain);
 487         kfree(pd);
 488 }
 489
 490 int usnic_uiom_attach_dev_to_pd(struct usnic_uiom_pd *pd, struct device *dev)
 491 {
 492         struct usnic_uiom_dev *uiom_dev;
 493         int err;
 494
 495         uiom_dev = kzalloc(sizeof(*uiom_dev), GFP_ATOMIC);
 496         if (!uiom_dev)
 497                 return -ENOMEM;
 498         uiom_dev->dev = dev;
 499
 500         err = iommu_attach_device(pd->domain, dev);
 501         if (err)
 502                 goto out_free_dev;
 503
 504         if (!iommu_capable(dev->bus, IOMMU_CAP_CACHE_COHERENCY)) {
 505                 usnic_err("IOMMU of %s does not support cache coherency\n",
 506                                 dev_name(dev));
 507                 err = -EINVAL;
 508                 goto out_detach_device;
 509         }
 510
 511         spin_lock(&pd->lock);
 512         list_add_tail(&uiom_dev->link, &pd->devs);
 513         pd->dev_cnt++;
 514         spin_unlock(&pd->lock);
 515
 516         return 0;
 517
 518 out_detach_device:
 519         iommu_detach_device(pd->domain, dev);
 520 out_free_dev:
 521         kfree(uiom_dev);
 522         return err;
 523 }
 524
 525 void usnic_uiom_detach_dev_from_pd(struct usnic_uiom_pd *pd, struct device *dev)
 526 {
 527         struct usnic_uiom_dev *uiom_dev;
 528         int found = 0;
 529
 530         spin_lock(&pd->lock);
 531         list_for_each_entry(uiom_dev, &pd->devs, link) {
 532                 if (uiom_dev->dev == dev) {
 533                         found = 1;
 534                         break;
 535                 }
 536         }
 537
 538         if (!found) {
 539                 usnic_err("Unable to free dev %s - not found\n",
 540                                 dev_name(dev));
 541                 spin_unlock(&pd->lock);
 542                 return;
 543         }
 544
 545         list_del(&uiom_dev->link);
 546         pd->dev_cnt--;
 547         spin_unlock(&pd->lock);
 548
 549         return iommu_detach_device(pd->domain, dev);
 550 }
 551
 552 struct device **usnic_uiom_get_dev_list(struct usnic_uiom_pd *pd)
 553 {
 554         struct usnic_uiom_dev *uiom_dev;
 555         struct device **devs;
 556         int i = 0;
 557
 558         spin_lock(&pd->lock);
 559         devs = kcalloc(pd->dev_cnt + 1, sizeof(*devs), GFP_ATOMIC);
 560         if (!devs) {
 561                 devs = ERR_PTR(-ENOMEM);
 562                 goto out;
 563         }
 564
 565         list_for_each_entry(uiom_dev, &pd->devs, link) {
 566                 devs[i++] = uiom_dev->dev;
 567         }
 568 out:
 569         spin_unlock(&pd->lock);
 570         return devs;
 571 }
 572
 573 void usnic_uiom_free_dev_list(struct device **devs)
 574 {
 575         kfree(devs);
 576 }
 577
 578 int usnic_uiom_init(char *drv_name)
 579 {
 580         if (!iommu_present(&pci_bus_type)) {
 581                 usnic_err("IOMMU required but not present or enabled.  USNIC QPs will not function w/o enabling IOMMU\n");
 582                 return -EPERM;
 583         }
 584
 585         usnic_uiom_wq = create_workqueue(drv_name);
 586         if (!usnic_uiom_wq) {
 587                 usnic_err("Unable to alloc wq for drv %s\n", drv_name);
 588                 return -ENOMEM;
 589         }
 590
 591         return 0;
 592 }
 593
 594 void usnic_uiom_fini(void)
 595 {
 596         flush_workqueue(usnic_uiom_wq);
 597         destroy_workqueue(usnic_uiom_wq);
 598 }