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