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