linux/drivers/infiniband/hw/usnic/usnic_uiom.c
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   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
  55static 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
  66static 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                        unpin_user_pages_dirty_lock(&page, 1, dirty);
  79                        usnic_dbg("pa: %pa\n", &pa);
  80                }
  81                kfree(chunk);
  82        }
  83}
  84
  85static 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        mmap_read_lock(mm);
 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 = pin_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
 183out:
 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        mmap_read_unlock(mm);
 191        free_page((unsigned long) page_list);
 192        return ret;
 193}
 194
 195static 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
 214static 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
 244static 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) {
 263iter_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
 329err_out:
 330        usnic_uiom_unmap_sorted_intervals(intervals, pd);
 331        return err;
 332}
 333
 334struct 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
 410out_unmap_intervals:
 411        usnic_uiom_unmap_sorted_intervals(&sorted_diff_intervals, pd);
 412out_put_intervals:
 413        usnic_uiom_put_interval_set(&sorted_diff_intervals);
 414out_put_pages:
 415        usnic_uiom_put_pages(&uiomr->chunk_list, 0);
 416        spin_unlock(&pd->lock);
 417        mmdrop(uiomr->owning_mm);
 418out_free_uiomr:
 419        kfree(uiomr);
 420        return ERR_PTR(err);
 421}
 422
 423static void __usnic_uiom_release_tail(struct usnic_uiom_reg *uiomr)
 424{
 425        mmdrop(uiomr->owning_mm);
 426        kfree(uiomr);
 427}
 428
 429static 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
 434void 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
 442struct 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
 466void usnic_uiom_dealloc_pd(struct usnic_uiom_pd *pd)
 467{
 468        iommu_domain_free(pd->domain);
 469        kfree(pd);
 470}
 471
 472int 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
 500out_detach_device:
 501        iommu_detach_device(pd->domain, dev);
 502out_free_dev:
 503        kfree(uiom_dev);
 504        return err;
 505}
 506
 507void 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
 534struct 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        }
 550out:
 551        spin_unlock(&pd->lock);
 552        return devs;
 553}
 554
 555void usnic_uiom_free_dev_list(struct device **devs)
 556{
 557        kfree(devs);
 558}
 559
 560int 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}
 569