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/dma-attrs.h>
  40 #include <linux/iommu.h>
  41 #include <linux/workqueue.h>
  42 #include <linux/list.h>
  43 #include <linux/pci.h>
  44
  45 #include "usnic_log.h"
  46 #include "usnic_uiom.h"
  47 #include "usnic_uiom_interval_tree.h"
  48
  49 static struct workqueue_struct *usnic_uiom_wq;
  50
  51 #define USNIC_UIOM_PAGE_CHUNK                                           \
  52         ((PAGE_SIZE - offsetof(struct usnic_uiom_chunk, page_list))     /\
  53         ((void *) &((struct usnic_uiom_chunk *) 0)->page_list[1] -      \
  54         (void *) &((struct usnic_uiom_chunk *) 0)->page_list[0]))
  55
  56 static void usnic_uiom_reg_account(struct work_struct *work)
  57 {
  58         struct usnic_uiom_reg *umem = container_of(work,
  59                                                 struct usnic_uiom_reg, work);
  60
  61         down_write(&umem->mm->mmap_sem);
  62         umem->mm->locked_vm -= umem->diff;
  63         up_write(&umem->mm->mmap_sem);
  64         mmput(umem->mm);
  65         kfree(umem);
  66 }
  67
  68 static int usnic_uiom_dma_fault(struct iommu_domain *domain,
  69                                 struct device *dev,
  70                                 unsigned long iova, int flags,
  71                                 void *token)
  72 {
  73         usnic_err("Device %s iommu fault domain 0x%pK va 0x%lx flags 0x%x\n",
  74                 dev_name(dev),
  75                 domain, iova, flags);
  76         return -ENOSYS;
  77 }
  78
  79 static void usnic_uiom_put_pages(struct list_head *chunk_list, int dirty)
  80 {
  81         struct usnic_uiom_chunk *chunk, *tmp;
  82         struct page *page;
  83         struct scatterlist *sg;
  84         int i;
  85         dma_addr_t pa;
  86
  87         list_for_each_entry_safe(chunk, tmp, chunk_list, list) {
  88                 for_each_sg(chunk->page_list, sg, chunk->nents, i) {
  89                         page = sg_page(sg);
  90                         pa = sg_phys(sg);
  91                         if (dirty)
  92                                 set_page_dirty_lock(page);
  93                         put_page(page);
  94                         usnic_dbg("pa: %pa\n", &pa);
  95                 }
  96                 kfree(chunk);
  97         }
  98 }
  99
 100 static int usnic_uiom_get_pages(unsigned long addr, size_t size, int writable,
 101                                 int dmasync, struct list_head *chunk_list)
 102 {
 103         struct page **page_list;
 104         struct scatterlist *sg;
 105         struct usnic_uiom_chunk *chunk;
 106         unsigned long locked;
 107         unsigned long lock_limit;
 108         unsigned long cur_base;
 109         unsigned long npages;
 110         int ret;
 111         int off;
 112         int i;
 113         int flags;
 114         dma_addr_t pa;
 115         DEFINE_DMA_ATTRS(attrs);
 116
 117         if (dmasync)
 118                 dma_set_attr(DMA_ATTR_WRITE_BARRIER, &attrs);
 119
 120         if (!can_do_mlock())
 121                 return -EPERM;
 122
 123         INIT_LIST_HEAD(chunk_list);
 124
 125         page_list = (struct page **) __get_free_page(GFP_KERNEL);
 126         if (!page_list)
 127                 return -ENOMEM;
 128
 129         npages = PAGE_ALIGN(size + (addr & ~PAGE_MASK)) >> PAGE_SHIFT;
 130
 131         down_write(&current->mm->mmap_sem);
 132
 133         locked = npages + current->mm->locked_vm;
 134         lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
 135
 136         if ((locked > lock_limit) && !capable(CAP_IPC_LOCK)) {
 137                 ret = -ENOMEM;
 138                 goto out;
 139         }
 140
 141         flags = IOMMU_READ | IOMMU_CACHE;
 142         flags |= (writable) ? IOMMU_WRITE : 0;
 143         cur_base = addr & PAGE_MASK;
 144         ret = 0;
 145
 146         while (npages) {
 147                 ret = get_user_pages(current, current->mm, cur_base,
 148                                         min_t(unsigned long, npages,
 149                                         PAGE_SIZE / sizeof(struct page *)),
 150                                         1, !writable, page_list, NULL);
 151
 152                 if (ret < 0)
 153                         goto out;
 154
 155                 npages -= ret;
 156                 off = 0;
 157
 158                 while (ret) {
 159                         chunk = kmalloc(sizeof(*chunk) +
 160                                         sizeof(struct scatterlist) *
 161                                         min_t(int, ret, USNIC_UIOM_PAGE_CHUNK),
 162                                         GFP_KERNEL);
 163                         if (!chunk) {
 164                                 ret = -ENOMEM;
 165                                 goto out;
 166                         }
 167
 168                         chunk->nents = min_t(int, ret, USNIC_UIOM_PAGE_CHUNK);
 169                         sg_init_table(chunk->page_list, chunk->nents);
 170                         for_each_sg(chunk->page_list, sg, chunk->nents, i) {
 171                                 sg_set_page(sg, page_list[i + off],
 172                                                 PAGE_SIZE, 0);
 173                                 pa = sg_phys(sg);
 174                                 usnic_dbg("va: 0x%lx pa: %pa\n",
 175                                                 cur_base + i*PAGE_SIZE, &pa);
 176                         }
 177                         cur_base += chunk->nents * PAGE_SIZE;
 178                         ret -= chunk->nents;
 179                         off += chunk->nents;
 180                         list_add_tail(&chunk->list, chunk_list);
 181                 }
 182
 183                 ret = 0;
 184         }
 185
 186 out:
 187         if (ret < 0)
 188                 usnic_uiom_put_pages(chunk_list, 0);
 189         else
 190                 current->mm->locked_vm = locked;
 191
 192         up_write(&current->mm->mmap_sem);
 193         free_page((unsigned long) page_list);
 194         return ret;
 195 }
 196
 197 static void usnic_uiom_unmap_sorted_intervals(struct list_head *intervals,
 198                                                 struct usnic_uiom_pd *pd)
 199 {
 200         struct usnic_uiom_interval_node *interval, *tmp;
 201         long unsigned va, size;
 202
 203         list_for_each_entry_safe(interval, tmp, intervals, link) {
 204                 va = interval->start << PAGE_SHIFT;
 205                 size = ((interval->last - interval->start) + 1) << PAGE_SHIFT;
 206                 while (size > 0) {
 207                         /* Workaround for RH 970401 */
 208                         usnic_dbg("va 0x%lx size 0x%lx", va, PAGE_SIZE);
 209                         iommu_unmap(pd->domain, va, PAGE_SIZE);
 210                         va += PAGE_SIZE;
 211                         size -= PAGE_SIZE;
 212                 }
 213         }
 214 }
 215
 216 static void __usnic_uiom_reg_release(struct usnic_uiom_pd *pd,
 217                                         struct usnic_uiom_reg *uiomr,
 218                                         int dirty)
 219 {
 220         int npages;
 221         unsigned long vpn_start, vpn_last;
 222         struct usnic_uiom_interval_node *interval, *tmp;
 223         int writable = 0;
 224         LIST_HEAD(rm_intervals);
 225
 226         npages = PAGE_ALIGN(uiomr->length + uiomr->offset) >> PAGE_SHIFT;
 227         vpn_start = (uiomr->va & PAGE_MASK) >> PAGE_SHIFT;
 228         vpn_last = vpn_start + npages - 1;
 229
 230         spin_lock(&pd->lock);
 231         usnic_uiom_remove_interval(&pd->rb_root, vpn_start,
 232                                         vpn_last, &rm_intervals);
 233         usnic_uiom_unmap_sorted_intervals(&rm_intervals, pd);
 234
 235         list_for_each_entry_safe(interval, tmp, &rm_intervals, link) {
 236                 if (interval->flags & IOMMU_WRITE)
 237                         writable = 1;
 238                 list_del(&interval->link);
 239                 kfree(interval);
 240         }
 241
 242         usnic_uiom_put_pages(&uiomr->chunk_list, dirty & writable);
 243         spin_unlock(&pd->lock);
 244 }
 245
 246 static int usnic_uiom_map_sorted_intervals(struct list_head *intervals,
 247                                                 struct usnic_uiom_reg *uiomr)
 248 {
 249         int i, err;
 250         size_t size;
 251         struct usnic_uiom_chunk *chunk;
 252         struct usnic_uiom_interval_node *interval_node;
 253         dma_addr_t pa;
 254         dma_addr_t pa_start = 0;
 255         dma_addr_t pa_end = 0;
 256         long int va_start = -EINVAL;
 257         struct usnic_uiom_pd *pd = uiomr->pd;
 258         long int va = uiomr->va & PAGE_MASK;
 259         int flags = IOMMU_READ | IOMMU_CACHE;
 260
 261         flags |= (uiomr->writable) ? IOMMU_WRITE : 0;
 262         chunk = list_first_entry(&uiomr->chunk_list, struct usnic_uiom_chunk,
 263                                                                         list);
 264         list_for_each_entry(interval_node, intervals, link) {
 265 iter_chunk:
 266                 for (i = 0; i < chunk->nents; i++, va += PAGE_SIZE) {
 267                         pa = sg_phys(&chunk->page_list[i]);
 268                         if ((va >> PAGE_SHIFT) < interval_node->start)
 269                                 continue;
 270
 271                         if ((va >> PAGE_SHIFT) == interval_node->start) {
 272                                 /* First page of the interval */
 273                                 va_start = va;
 274                                 pa_start = pa;
 275                                 pa_end = pa;
 276                         }
 277
 278                         WARN_ON(va_start == -EINVAL);
 279
 280                         if ((pa_end + PAGE_SIZE != pa) &&
 281                                         (pa != pa_start)) {
 282                                 /* PAs are not contiguous */
 283                                 size = pa_end - pa_start + PAGE_SIZE;
 284                                 usnic_dbg("va 0x%lx pa %pa size 0x%zx flags 0x%x",
 285                                         va_start, &pa_start, size, flags);
 286                                 err = iommu_map(pd->domain, va_start, pa_start,
 287                                                         size, flags);
 288                                 if (err) {
 289                                         usnic_err("Failed to map va 0x%lx pa %pa size 0x%zx with err %d\n",
 290                                                 va_start, &pa_start, size, err);
 291                                         goto err_out;
 292                                 }
 293                                 va_start = va;
 294                                 pa_start = pa;
 295                                 pa_end = pa;
 296                         }
 297
 298                         if ((va >> PAGE_SHIFT) == interval_node->last) {
 299                                 /* Last page of the interval */
 300                                 size = pa - pa_start + PAGE_SIZE;
 301                                 usnic_dbg("va 0x%lx pa %pa size 0x%zx flags 0x%x\n",
 302                                         va_start, &pa_start, size, flags);
 303                                 err = iommu_map(pd->domain, va_start, pa_start,
 304                                                 size, flags);
 305                                 if (err) {
 306                                         usnic_err("Failed to map va 0x%lx pa %pa size 0x%zx with err %d\n",
 307                                                 va_start, &pa_start, size, err);
 308                                         goto err_out;
 309                                 }
 310                                 break;
 311                         }
 312
 313                         if (pa != pa_start)
 314                                 pa_end += PAGE_SIZE;
 315                 }
 316
 317                 if (i == chunk->nents) {
 318                         /*
 319                          * Hit last entry of the chunk,
 320                          * hence advance to next chunk
 321                          */
 322                         chunk = list_first_entry(&chunk->list,
 323                                                         struct usnic_uiom_chunk,
 324                                                         list);
 325                         goto iter_chunk;
 326                 }
 327         }
 328
 329         return 0;
 330
 331 err_out:
 332         usnic_uiom_unmap_sorted_intervals(intervals, pd);
 333         return err;
 334 }
 335
 336 struct usnic_uiom_reg *usnic_uiom_reg_get(struct usnic_uiom_pd *pd,
 337                                                 unsigned long addr, size_t size,
 338                                                 int writable, int dmasync)
 339 {
 340         struct usnic_uiom_reg *uiomr;
 341         unsigned long va_base, vpn_start, vpn_last;
 342         unsigned long npages;
 343         int offset, err;
 344         LIST_HEAD(sorted_diff_intervals);
 345
 346         /*
 347          * Intel IOMMU map throws an error if a translation entry is
 348          * changed from read to write.  This module may not unmap
 349          * and then remap the entry after fixing the permission
 350          * b/c this open up a small windows where hw DMA may page fault
 351          * Hence, make all entries to be writable.
 352          */
 353         writable = 1;
 354
 355         va_base = addr & PAGE_MASK;
 356         offset = addr & ~PAGE_MASK;
 357         npages = PAGE_ALIGN(size + offset) >> PAGE_SHIFT;
 358         vpn_start = (addr & PAGE_MASK) >> PAGE_SHIFT;
 359         vpn_last = vpn_start + npages - 1;
 360
 361         uiomr = kmalloc(sizeof(*uiomr), GFP_KERNEL);
 362         if (!uiomr)
 363                 return ERR_PTR(-ENOMEM);
 364
 365         uiomr->va = va_base;
 366         uiomr->offset = offset;
 367         uiomr->length = size;
 368         uiomr->writable = writable;
 369         uiomr->pd = pd;
 370
 371         err = usnic_uiom_get_pages(addr, size, writable, dmasync,
 372                                         &uiomr->chunk_list);
 373         if (err) {
 374                 usnic_err("Failed get_pages vpn [0x%lx,0x%lx] err %d\n",
 375                                 vpn_start, vpn_last, err);
 376                 goto out_free_uiomr;
 377         }
 378
 379         spin_lock(&pd->lock);
 380         err = usnic_uiom_get_intervals_diff(vpn_start, vpn_last,
 381                                                 (writable) ? IOMMU_WRITE : 0,
 382                                                 IOMMU_WRITE,
 383                                                 &pd->rb_root,
 384                                                 &sorted_diff_intervals);
 385         if (err) {
 386                 usnic_err("Failed disjoint interval vpn [0x%lx,0x%lx] err %d\n",
 387                                                 vpn_start, vpn_last, err);
 388                 goto out_put_pages;
 389         }
 390
 391         err = usnic_uiom_map_sorted_intervals(&sorted_diff_intervals, uiomr);
 392         if (err) {
 393                 usnic_err("Failed map interval vpn [0x%lx,0x%lx] err %d\n",
 394                                                 vpn_start, vpn_last, err);
 395                 goto out_put_intervals;
 396
 397         }
 398
 399         err = usnic_uiom_insert_interval(&pd->rb_root, vpn_start, vpn_last,
 400                                         (writable) ? IOMMU_WRITE : 0);
 401         if (err) {
 402                 usnic_err("Failed insert interval vpn [0x%lx,0x%lx] err %d\n",
 403                                                 vpn_start, vpn_last, err);
 404                 goto out_unmap_intervals;
 405         }
 406
 407         usnic_uiom_put_interval_set(&sorted_diff_intervals);
 408         spin_unlock(&pd->lock);
 409
 410         return uiomr;
 411
 412 out_unmap_intervals:
 413         usnic_uiom_unmap_sorted_intervals(&sorted_diff_intervals, pd);
 414 out_put_intervals:
 415         usnic_uiom_put_interval_set(&sorted_diff_intervals);
 416 out_put_pages:
 417         usnic_uiom_put_pages(&uiomr->chunk_list, 0);
 418         spin_unlock(&pd->lock);
 419 out_free_uiomr:
 420         kfree(uiomr);
 421         return ERR_PTR(err);
 422 }
 423
 424 void usnic_uiom_reg_release(struct usnic_uiom_reg *uiomr, int closing)
 425 {
 426         struct mm_struct *mm;
 427         unsigned long diff;
 428
 429         __usnic_uiom_reg_release(uiomr->pd, uiomr, 1);
 430
 431         mm = get_task_mm(current);
 432         if (!mm) {
 433                 kfree(uiomr);
 434                 return;
 435         }
 436
 437         diff = PAGE_ALIGN(uiomr->length + uiomr->offset) >> PAGE_SHIFT;
 438
 439         /*
 440          * We may be called with the mm's mmap_sem already held.  This
 441          * can happen when a userspace munmap() is the call that drops
 442          * the last reference to our file and calls our release
 443          * method.  If there are memory regions to destroy, we'll end
 444          * up here and not be able to take the mmap_sem.  In that case
 445          * we defer the vm_locked accounting to the system workqueue.
 446          */
 447         if (closing) {
 448                 if (!down_write_trylock(&mm->mmap_sem)) {
 449                         INIT_WORK(&uiomr->work, usnic_uiom_reg_account);
 450                         uiomr->mm = mm;
 451                         uiomr->diff = diff;
 452
 453                         queue_work(usnic_uiom_wq, &uiomr->work);
 454                         return;
 455                 }
 456         } else
 457                 down_write(&mm->mmap_sem);
 458
 459         current->mm->locked_vm -= diff;
 460         up_write(&mm->mmap_sem);
 461         mmput(mm);
 462         kfree(uiomr);
 463 }
 464
 465 struct usnic_uiom_pd *usnic_uiom_alloc_pd(void)
 466 {
 467         struct usnic_uiom_pd *pd;
 468         void *domain;
 469
 470         pd = kzalloc(sizeof(*pd), GFP_KERNEL);
 471         if (!pd)
 472                 return ERR_PTR(-ENOMEM);
 473
 474         pd->domain = domain = iommu_domain_alloc(&pci_bus_type);
 475         if (!domain) {
 476                 usnic_err("Failed to allocate IOMMU domain");
 477                 kfree(pd);
 478                 return ERR_PTR(-ENOMEM);
 479         }
 480
 481         iommu_set_fault_handler(pd->domain, usnic_uiom_dma_fault, NULL);
 482
 483         spin_lock_init(&pd->lock);
 484         INIT_LIST_HEAD(&pd->devs);
 485
 486         return pd;
 487 }
 488
 489 void usnic_uiom_dealloc_pd(struct usnic_uiom_pd *pd)
 490 {
 491         iommu_domain_free(pd->domain);
 492         kfree(pd);
 493 }
 494
 495 int usnic_uiom_attach_dev_to_pd(struct usnic_uiom_pd *pd, struct device *dev)
 496 {
 497         struct usnic_uiom_dev *uiom_dev;
 498         int err;
 499
 500         uiom_dev = kzalloc(sizeof(*uiom_dev), GFP_ATOMIC);
 501         if (!uiom_dev)
 502                 return -ENOMEM;
 503         uiom_dev->dev = dev;
 504
 505         err = iommu_attach_device(pd->domain, dev);
 506         if (err)
 507                 goto out_free_dev;
 508
 509         if (!iommu_capable(dev->bus, IOMMU_CAP_CACHE_COHERENCY)) {
 510                 usnic_err("IOMMU of %s does not support cache coherency\n",
 511                                 dev_name(dev));
 512                 err = -EINVAL;
 513                 goto out_detach_device;
 514         }
 515
 516         spin_lock(&pd->lock);
 517         list_add_tail(&uiom_dev->link, &pd->devs);
 518         pd->dev_cnt++;
 519         spin_unlock(&pd->lock);
 520
 521         return 0;
 522
 523 out_detach_device:
 524         iommu_detach_device(pd->domain, dev);
 525 out_free_dev:
 526         kfree(uiom_dev);
 527         return err;
 528 }
 529
 530 void usnic_uiom_detach_dev_from_pd(struct usnic_uiom_pd *pd, struct device *dev)
 531 {
 532         struct usnic_uiom_dev *uiom_dev;
 533         int found = 0;
 534
 535         spin_lock(&pd->lock);
 536         list_for_each_entry(uiom_dev, &pd->devs, link) {
 537                 if (uiom_dev->dev == dev) {
 538                         found = 1;
 539                         break;
 540                 }
 541         }
 542
 543         if (!found) {
 544                 usnic_err("Unable to free dev %s - not found\n",
 545                                 dev_name(dev));
 546                 spin_unlock(&pd->lock);
 547                 return;
 548         }
 549
 550         list_del(&uiom_dev->link);
 551         pd->dev_cnt--;
 552         spin_unlock(&pd->lock);
 553
 554         return iommu_detach_device(pd->domain, dev);
 555 }
 556
 557 struct device **usnic_uiom_get_dev_list(struct usnic_uiom_pd *pd)
 558 {
 559         struct usnic_uiom_dev *uiom_dev;
 560         struct device **devs;
 561         int i = 0;
 562
 563         spin_lock(&pd->lock);
 564         devs = kcalloc(pd->dev_cnt + 1, sizeof(*devs), GFP_ATOMIC);
 565         if (!devs) {
 566                 devs = ERR_PTR(-ENOMEM);
 567                 goto out;
 568         }
 569
 570         list_for_each_entry(uiom_dev, &pd->devs, link) {
 571                 devs[i++] = uiom_dev->dev;
 572         }
 573 out:
 574         spin_unlock(&pd->lock);
 575         return devs;
 576 }
 577
 578 void usnic_uiom_free_dev_list(struct device **devs)
 579 {
 580         kfree(devs);
 581 }
 582
 583 int usnic_uiom_init(char *drv_name)
 584 {
 585         if (!iommu_present(&pci_bus_type)) {
 586                 usnic_err("IOMMU required but not present or enabled.  USNIC QPs will not function w/o enabling IOMMU\n");
 587                 return -EPERM;
 588         }
 589
 590         usnic_uiom_wq = create_workqueue(drv_name);
 591         if (!usnic_uiom_wq) {
 592                 usnic_err("Unable to alloc wq for drv %s\n", drv_name);
 593                 return -ENOMEM;
 594         }
 595
 596         return 0;
 597 }
 598
 599 void usnic_uiom_fini(void)
 600 {
 601         flush_workqueue(usnic_uiom_wq);
 602         destroy_workqueue(usnic_uiom_wq);
 603 }