root/drivers/infiniband/hw/usnic/usnic_uiom.c

DEFINITIONS

1. usnic_uiom_dma_fault
2. usnic_uiom_put_pages
3. usnic_uiom_get_pages
4. usnic_uiom_unmap_sorted_intervals
5. __usnic_uiom_reg_release
6. usnic_uiom_map_sorted_intervals
7. usnic_uiom_reg_get
8. __usnic_uiom_release_tail
9. usnic_uiom_num_pages
10. usnic_uiom_reg_release
11. usnic_uiom_alloc_pd
12. usnic_uiom_dealloc_pd
13. usnic_uiom_attach_dev_to_pd
14. usnic_uiom_detach_dev_from_pd
15. usnic_uiom_get_dev_list
16. usnic_uiom_free_dev_list
17. usnic_uiom_init

   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 #include <rdma/ib_verbs.h>
  45 
  46 #include "usnic_log.h"
  47 #include "usnic_uiom.h"
  48 #include "usnic_uiom_interval_tree.h"
  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 int usnic_uiom_dma_fault(struct iommu_domain *domain,
  56                                 struct device *dev,
  57                                 unsigned long iova, int flags,
  58                                 void *token)
  59 {
  60         usnic_err("Device %s iommu fault domain 0x%pK va 0x%lx flags 0x%x\n",
  61                 dev_name(dev),
  62                 domain, iova, flags);
  63         return -ENOSYS;
  64 }
  65 
  66 static void usnic_uiom_put_pages(struct list_head *chunk_list, int dirty)
  67 {
  68         struct usnic_uiom_chunk *chunk, *tmp;
  69         struct page *page;
  70         struct scatterlist *sg;
  71         int i;
  72         dma_addr_t pa;
  73 
  74         list_for_each_entry_safe(chunk, tmp, chunk_list, list) {
  75                 for_each_sg(chunk->page_list, sg, chunk->nents, i) {
  76                         page = sg_page(sg);
  77                         pa = sg_phys(sg);
  78                         put_user_pages_dirty_lock(&page, 1, dirty);
  79                         usnic_dbg("pa: %pa\n", &pa);
  80                 }
  81                 kfree(chunk);
  82         }
  83 }
  84 
  85 static int usnic_uiom_get_pages(unsigned long addr, size_t size, int writable,
  86                                 int dmasync, struct usnic_uiom_reg *uiomr)
  87 {
  88         struct list_head *chunk_list = &uiomr->chunk_list;
  89         struct page **page_list;
  90         struct scatterlist *sg;
  91         struct usnic_uiom_chunk *chunk;
  92         unsigned long locked;
  93         unsigned long lock_limit;
  94         unsigned long cur_base;
  95         unsigned long npages;
  96         int ret;
  97         int off;
  98         int i;
  99         int flags;
 100         dma_addr_t pa;
 101         unsigned int gup_flags;
 102         struct mm_struct *mm;
 103 
 104         /*
 105          * If the combination of the addr and size requested for this memory
 106          * region causes an integer overflow, return error.
 107          */
 108         if (((addr + size) < addr) || PAGE_ALIGN(addr + size) < (addr + size))
 109                 return -EINVAL;
 110 
 111         if (!size)
 112                 return -EINVAL;
 113 
 114         if (!can_do_mlock())
 115                 return -EPERM;
 116 
 117         INIT_LIST_HEAD(chunk_list);
 118 
 119         page_list = (struct page **) __get_free_page(GFP_KERNEL);
 120         if (!page_list)
 121                 return -ENOMEM;
 122 
 123         npages = PAGE_ALIGN(size + (addr & ~PAGE_MASK)) >> PAGE_SHIFT;
 124 
 125         uiomr->owning_mm = mm = current->mm;
 126         down_read(&mm->mmap_sem);
 127 
 128         locked = atomic64_add_return(npages, &current->mm->pinned_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         gup_flags = FOLL_WRITE;
 139         gup_flags |= (writable) ? 0 : FOLL_FORCE;
 140         cur_base = addr & PAGE_MASK;
 141         ret = 0;
 142 
 143         while (npages) {
 144                 ret = get_user_pages(cur_base,
 145                                      min_t(unsigned long, npages,
 146                                      PAGE_SIZE / sizeof(struct page *)),
 147                                      gup_flags | FOLL_LONGTERM,
 148                                      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(struct_size(chunk, page_list,
 158                                         min_t(int, ret, USNIC_UIOM_PAGE_CHUNK)),
 159                                         GFP_KERNEL);
 160                         if (!chunk) {
 161                                 ret = -ENOMEM;
 162                                 goto out;
 163                         }
 164 
 165                         chunk->nents = min_t(int, ret, USNIC_UIOM_PAGE_CHUNK);
 166                         sg_init_table(chunk->page_list, chunk->nents);
 167                         for_each_sg(chunk->page_list, sg, chunk->nents, i) {
 168                                 sg_set_page(sg, page_list[i + off],
 169                                                 PAGE_SIZE, 0);
 170                                 pa = sg_phys(sg);
 171                                 usnic_dbg("va: 0x%lx pa: %pa\n",
 172                                                 cur_base + i*PAGE_SIZE, &pa);
 173                         }
 174                         cur_base += chunk->nents * PAGE_SIZE;
 175                         ret -= chunk->nents;
 176                         off += chunk->nents;
 177                         list_add_tail(&chunk->list, chunk_list);
 178                 }
 179 
 180                 ret = 0;
 181         }
 182 
 183 out:
 184         if (ret < 0) {
 185                 usnic_uiom_put_pages(chunk_list, 0);
 186                 atomic64_sub(npages, &current->mm->pinned_vm);
 187         } else
 188                 mmgrab(uiomr->owning_mm);
 189 
 190         up_read(&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->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);
 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->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->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         mmdrop(uiomr->owning_mm);
 418 out_free_uiomr:
 419         kfree(uiomr);
 420         return ERR_PTR(err);
 421 }
 422 
 423 static void __usnic_uiom_release_tail(struct usnic_uiom_reg *uiomr)
 424 {
 425         mmdrop(uiomr->owning_mm);
 426         kfree(uiomr);
 427 }
 428 
 429 static inline size_t usnic_uiom_num_pages(struct usnic_uiom_reg *uiomr)
 430 {
 431         return PAGE_ALIGN(uiomr->length + uiomr->offset) >> PAGE_SHIFT;
 432 }
 433 
 434 void usnic_uiom_reg_release(struct usnic_uiom_reg *uiomr)
 435 {
 436         __usnic_uiom_reg_release(uiomr->pd, uiomr, 1);
 437 
 438         atomic64_sub(usnic_uiom_num_pages(uiomr), &uiomr->owning_mm->pinned_vm);
 439         __usnic_uiom_release_tail(uiomr);
 440 }
 441 
 442 struct usnic_uiom_pd *usnic_uiom_alloc_pd(void)
 443 {
 444         struct usnic_uiom_pd *pd;
 445         void *domain;
 446 
 447         pd = kzalloc(sizeof(*pd), GFP_KERNEL);
 448         if (!pd)
 449                 return ERR_PTR(-ENOMEM);
 450 
 451         pd->domain = domain = iommu_domain_alloc(&pci_bus_type);
 452         if (!domain) {
 453                 usnic_err("Failed to allocate IOMMU domain");
 454                 kfree(pd);
 455                 return ERR_PTR(-ENOMEM);
 456         }
 457 
 458         iommu_set_fault_handler(pd->domain, usnic_uiom_dma_fault, NULL);
 459 
 460         spin_lock_init(&pd->lock);
 461         INIT_LIST_HEAD(&pd->devs);
 462 
 463         return pd;
 464 }
 465 
 466 void usnic_uiom_dealloc_pd(struct usnic_uiom_pd *pd)
 467 {
 468         iommu_domain_free(pd->domain);
 469         kfree(pd);
 470 }
 471 
 472 int usnic_uiom_attach_dev_to_pd(struct usnic_uiom_pd *pd, struct device *dev)
 473 {
 474         struct usnic_uiom_dev *uiom_dev;
 475         int err;
 476 
 477         uiom_dev = kzalloc(sizeof(*uiom_dev), GFP_ATOMIC);
 478         if (!uiom_dev)
 479                 return -ENOMEM;
 480         uiom_dev->dev = dev;
 481 
 482         err = iommu_attach_device(pd->domain, dev);
 483         if (err)
 484                 goto out_free_dev;
 485 
 486         if (!iommu_capable(dev->bus, IOMMU_CAP_CACHE_COHERENCY)) {
 487                 usnic_err("IOMMU of %s does not support cache coherency\n",
 488                                 dev_name(dev));
 489                 err = -EINVAL;
 490                 goto out_detach_device;
 491         }
 492 
 493         spin_lock(&pd->lock);
 494         list_add_tail(&uiom_dev->link, &pd->devs);
 495         pd->dev_cnt++;
 496         spin_unlock(&pd->lock);
 497 
 498         return 0;
 499 
 500 out_detach_device:
 501         iommu_detach_device(pd->domain, dev);
 502 out_free_dev:
 503         kfree(uiom_dev);
 504         return err;
 505 }
 506 
 507 void usnic_uiom_detach_dev_from_pd(struct usnic_uiom_pd *pd, struct device *dev)
 508 {
 509         struct usnic_uiom_dev *uiom_dev;
 510         int found = 0;
 511 
 512         spin_lock(&pd->lock);
 513         list_for_each_entry(uiom_dev, &pd->devs, link) {
 514                 if (uiom_dev->dev == dev) {
 515                         found = 1;
 516                         break;
 517                 }
 518         }
 519 
 520         if (!found) {
 521                 usnic_err("Unable to free dev %s - not found\n",
 522                                 dev_name(dev));
 523                 spin_unlock(&pd->lock);
 524                 return;
 525         }
 526 
 527         list_del(&uiom_dev->link);
 528         pd->dev_cnt--;
 529         spin_unlock(&pd->lock);
 530 
 531         return iommu_detach_device(pd->domain, dev);
 532 }
 533 
 534 struct device **usnic_uiom_get_dev_list(struct usnic_uiom_pd *pd)
 535 {
 536         struct usnic_uiom_dev *uiom_dev;
 537         struct device **devs;
 538         int i = 0;
 539 
 540         spin_lock(&pd->lock);
 541         devs = kcalloc(pd->dev_cnt + 1, sizeof(*devs), GFP_ATOMIC);
 542         if (!devs) {
 543                 devs = ERR_PTR(-ENOMEM);
 544                 goto out;
 545         }
 546 
 547         list_for_each_entry(uiom_dev, &pd->devs, link) {
 548                 devs[i++] = uiom_dev->dev;
 549         }
 550 out:
 551         spin_unlock(&pd->lock);
 552         return devs;
 553 }
 554 
 555 void usnic_uiom_free_dev_list(struct device **devs)
 556 {
 557         kfree(devs);
 558 }
 559 
 560 int usnic_uiom_init(char *drv_name)
 561 {
 562         if (!iommu_present(&pci_bus_type)) {
 563                 usnic_err("IOMMU required but not present or enabled.  USNIC QPs will not function w/o enabling IOMMU\n");
 564                 return -EPERM;
 565         }
 566 
 567         return 0;
 568 }