linux-core/drm_compat.c

   1 /**************************************************************************
   2  *
   3  * This kernel module is free software; you can redistribute it and/or
   4  * modify it under the terms of the GNU General Public License as
   5  * published by the Free Software Foundation; either version 2 of the
   6  * License, or (at your option) any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program; if not, write to the Free Software
  15  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  16  *
  17  **************************************************************************/
  18 /*
  19  * This code provides access to unexported mm kernel features. It is necessary
  20  * to use the new DRM memory manager code with kernels that don't support it
  21  * directly.
  22  *
  23  * Authors: Thomas Hellstrom <thomas-at-tungstengraphics-dot-com>
  24  *          Linux kernel mm subsystem authors.
  25  *          (Most code taken from there).
  26  */
  27
  28 #include "drmP.h"
  29
  30 #if defined(CONFIG_X86) && (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,15))
  31
  32 /*
  33  * These have bad performance in the AGP module for the indicated kernel versions.
  34  */
  35
  36 int drm_map_page_into_agp(struct page *page)
  37 {
  38         int i;
  39         i = change_page_attr(page, 1, PAGE_KERNEL_NOCACHE);
  40         /* Caller's responsibility to call global_flush_tlb() for
  41          * performance reasons */
  42         return i;
  43 }
  44
  45 int drm_unmap_page_from_agp(struct page *page)
  46 {
  47         int i;
  48         i = change_page_attr(page, 1, PAGE_KERNEL);
  49         /* Caller's responsibility to call global_flush_tlb() for
  50          * performance reasons */
  51         return i;
  52 }
  53 #endif
  54
  55
  56 #if  (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19))
  57
  58 /*
  59  * The protection map was exported in 2.6.19
  60  */
  61
  62 pgprot_t vm_get_page_prot(unsigned long vm_flags)
  63 {
  64 #ifdef MODULE
  65         static pgprot_t drm_protection_map[16] = {
  66                 __P000, __P001, __P010, __P011, __P100, __P101, __P110, __P111,
  67                 __S000, __S001, __S010, __S011, __S100, __S101, __S110, __S111
  68         };
  69
  70         return drm_protection_map[vm_flags & 0x0F];
  71 #else
  72         extern pgprot_t protection_map[];
  73         return protection_map[vm_flags & 0x0F];
  74 #endif
  75 };
  76 #endif
  77
  78
  79 #if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,15))
  80
  81 /*
  82  * vm code for kernels below 2.6.15 in which version a major vm write
  83  * occured. This implement a simple straightforward
  84  * version similar to what's going to be
  85  * in kernel 2.6.19+
  86  * Kernels below 2.6.15 use nopage whereas 2.6.19 and upwards use
  87  * nopfn.
  88  */
  89
  90 static struct {
  91         spinlock_t lock;
  92         struct page *dummy_page;
  93         atomic_t present;
  94 } drm_np_retry =
  95 {SPIN_LOCK_UNLOCKED, NOPAGE_OOM, ATOMIC_INIT(0)};
  96
  97
  98 static struct page *drm_bo_vm_fault(struct vm_area_struct *vma,
  99                                     struct fault_data *data);
 100
 101
 102 struct page * get_nopage_retry(void)
 103 {
 104         if (atomic_read(&drm_np_retry.present) == 0) {
 105                 struct page *page = alloc_page(GFP_KERNEL);
 106                 if (!page)
 107                         return NOPAGE_OOM;
 108                 spin_lock(&drm_np_retry.lock);
 109                 drm_np_retry.dummy_page = page;
 110                 atomic_set(&drm_np_retry.present,1);
 111                 spin_unlock(&drm_np_retry.lock);
 112         }
 113         get_page(drm_np_retry.dummy_page);
 114         return drm_np_retry.dummy_page;
 115 }
 116
 117 void free_nopage_retry(void)
 118 {
 119         if (atomic_read(&drm_np_retry.present) == 1) {
 120                 spin_lock(&drm_np_retry.lock);
 121                 __free_page(drm_np_retry.dummy_page);
 122                 drm_np_retry.dummy_page = NULL;
 123                 atomic_set(&drm_np_retry.present, 0);
 124                 spin_unlock(&drm_np_retry.lock);
 125         }
 126 }
 127
 128 struct page *drm_bo_vm_nopage(struct vm_area_struct *vma,
 129                                unsigned long address,
 130                                int *type)
 131 {
 132         struct fault_data data;
 133
 134         if (type)
 135                 *type = VM_FAULT_MINOR;
 136
 137         data.address = address;
 138         data.vma = vma;
 139         drm_bo_vm_fault(vma, &data);
 140         switch (data.type) {
 141         case VM_FAULT_OOM:
 142                 return NOPAGE_OOM;
 143         case VM_FAULT_SIGBUS:
 144                 return NOPAGE_SIGBUS;
 145         default:
 146                 break;
 147         }
 148
 149         return NOPAGE_REFAULT;
 150 }
 151
 152 #endif
 153
 154 #if !defined(DRM_FULL_MM_COMPAT) && \
 155   ((LINUX_VERSION_CODE < KERNEL_VERSION(2,6,15)) || \
 156    (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,19)))
 157
 158 static int drm_pte_is_clear(struct vm_area_struct *vma,
 159                             unsigned long addr)
 160 {
 161         struct mm_struct *mm = vma->vm_mm;
 162         int ret = 1;
 163         pte_t *pte;
 164         pmd_t *pmd;
 165         pud_t *pud;
 166         pgd_t *pgd;
 167
 168         spin_lock(&mm->page_table_lock);
 169         pgd = pgd_offset(mm, addr);
 170         if (pgd_none(*pgd))
 171                 goto unlock;
 172         pud = pud_offset(pgd, addr);
 173         if (pud_none(*pud))
 174                 goto unlock;
 175         pmd = pmd_offset(pud, addr);
 176         if (pmd_none(*pmd))
 177                 goto unlock;
 178         pte = pte_offset_map(pmd, addr);
 179         if (!pte)
 180                 goto unlock;
 181         ret = pte_none(*pte);
 182         pte_unmap(pte);
 183  unlock:
 184         spin_unlock(&mm->page_table_lock);
 185         return ret;
 186 }
 187
 188 static int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
 189                   unsigned long pfn)
 190 {
 191         int ret;
 192         if (!drm_pte_is_clear(vma, addr))
 193                 return -EBUSY;
 194
 195         ret = io_remap_pfn_range(vma, addr, pfn, PAGE_SIZE, vma->vm_page_prot);
 196         return ret;
 197 }
 198
 199
 200 static struct page *drm_bo_vm_fault(struct vm_area_struct *vma,
 201                                     struct fault_data *data)
 202 {
 203         unsigned long address = data->address;
 204         struct drm_buffer_object *bo = (struct drm_buffer_object *) vma->vm_private_data;
 205         unsigned long page_offset;
 206         struct page *page = NULL;
 207         struct drm_ttm *ttm;
 208         struct drm_device *dev;
 209         unsigned long pfn;
 210         int err;
 211         unsigned long bus_base;
 212         unsigned long bus_offset;
 213         unsigned long bus_size;
 214
 215
 216         mutex_lock(&bo->mutex);
 217
 218         err = drm_bo_wait(bo, 0, 1, 0);
 219         if (err) {
 220                 data->type = (err == -EAGAIN) ?
 221                         VM_FAULT_MINOR : VM_FAULT_SIGBUS;
 222                 goto out_unlock;
 223         }
 224
 225
 226         /*
 227          * If buffer happens to be in a non-mappable location,
 228          * move it to a mappable.
 229          */
 230
 231         if (!(bo->mem.flags & DRM_BO_FLAG_MAPPABLE)) {
 232                 unsigned long _end = jiffies + 3*DRM_HZ;
 233                 uint32_t new_mask = bo->mem.mask |
 234                         DRM_BO_FLAG_MAPPABLE |
 235                         DRM_BO_FLAG_FORCE_MAPPABLE;
 236
 237                 do {
 238                         err = drm_bo_move_buffer(bo, new_mask, 0, 0);
 239                 } while((err == -EAGAIN) && !time_after_eq(jiffies, _end));
 240
 241                 if (err) {
 242                         DRM_ERROR("Timeout moving buffer to mappable location.\n");
 243                         data->type = VM_FAULT_SIGBUS;
 244                         goto out_unlock;
 245                 }
 246         }
 247
 248         if (address > vma->vm_end) {
 249                 data->type = VM_FAULT_SIGBUS;
 250                 goto out_unlock;
 251         }
 252
 253         dev = bo->dev;
 254         err = drm_bo_pci_offset(dev, &bo->mem, &bus_base, &bus_offset,
 255                                 &bus_size);
 256
 257         if (err) {
 258                 data->type = VM_FAULT_SIGBUS;
 259                 goto out_unlock;
 260         }
 261
 262         page_offset = (address - vma->vm_start) >> PAGE_SHIFT;
 263
 264         if (bus_size) {
 265                 struct drm_mem_type_manager *man = &dev->bm.man[bo->mem.mem_type];
 266
 267                 pfn = ((bus_base + bus_offset) >> PAGE_SHIFT) + page_offset;
 268                 vma->vm_page_prot = drm_io_prot(man->drm_bus_maptype, vma);
 269         } else {
 270                 ttm = bo->ttm;
 271
 272                 drm_ttm_fixup_caching(ttm);
 273                 page = drm_ttm_get_page(ttm, page_offset);
 274                 if (!page) {
 275                         data->type = VM_FAULT_OOM;
 276                         goto out_unlock;
 277                 }
 278                 pfn = page_to_pfn(page);
 279                 vma->vm_page_prot = (bo->mem.flags & DRM_BO_FLAG_CACHED) ?
 280                         vm_get_page_prot(vma->vm_flags) :
 281                         drm_io_prot(_DRM_TTM, vma);
 282         }
 283
 284         err = vm_insert_pfn(vma, address, pfn);
 285
 286         if (!err || err == -EBUSY)
 287                 data->type = VM_FAULT_MINOR;
 288         else
 289                 data->type = VM_FAULT_OOM;
 290 out_unlock:
 291         mutex_unlock(&bo->mutex);
 292         return NULL;
 293 }
 294
 295 #endif
 296
 297 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,19)) && \
 298   !defined(DRM_FULL_MM_COMPAT)
 299
 300 /**
 301  */
 302
 303 unsigned long drm_bo_vm_nopfn(struct vm_area_struct * vma,
 304                            unsigned long address)
 305 {
 306         struct fault_data data;
 307         data.address = address;
 308
 309         (void) drm_bo_vm_fault(vma, &data);
 310         if (data.type == VM_FAULT_OOM)
 311                 return NOPFN_OOM;
 312         else if (data.type == VM_FAULT_SIGBUS)
 313                 return NOPFN_SIGBUS;
 314
 315         /*
 316          * pfn already set.
 317          */
 318
 319         return 0;
 320 }
 321 #endif
 322
 323
 324 #ifdef DRM_ODD_MM_COMPAT
 325
 326 /*
 327  * VM compatibility code for 2.6.15-2.6.18. This code implements a complicated
 328  * workaround for a single BUG statement in do_no_page in these versions. The
 329  * tricky thing is that we need to take the mmap_sem in exclusive mode for _all_
 330  * vmas mapping the ttm, before dev->struct_mutex is taken. The way we do this is to
 331  * check first take the dev->struct_mutex, and then trylock all mmap_sems. If this
 332  * fails for a single mmap_sem, we have to release all sems and the dev->struct_mutex,
 333  * release the cpu and retry. We also need to keep track of all vmas mapping the ttm.
 334  * phew.
 335  */
 336
 337 typedef struct p_mm_entry {
 338         struct list_head head;
 339         struct mm_struct *mm;
 340         atomic_t refcount;
 341         int locked;
 342 } p_mm_entry_t;
 343
 344 typedef struct vma_entry {
 345         struct list_head head;
 346         struct vm_area_struct *vma;
 347 } vma_entry_t;
 348
 349
 350 struct page *drm_bo_vm_nopage(struct vm_area_struct *vma,
 351                                unsigned long address,
 352                                int *type)
 353 {
 354         struct drm_buffer_object *bo = (struct drm_buffer_object *) vma->vm_private_data;
 355         unsigned long page_offset;
 356         struct page *page;
 357         struct drm_ttm *ttm;
 358         struct drm_device *dev;
 359
 360         mutex_lock(&bo->mutex);
 361
 362         if (type)
 363                 *type = VM_FAULT_MINOR;
 364
 365         if (address > vma->vm_end) {
 366                 page = NOPAGE_SIGBUS;
 367                 goto out_unlock;
 368         }
 369
 370         dev = bo->dev;
 371
 372         if (drm_mem_reg_is_pci(dev, &bo->mem)) {
 373                 DRM_ERROR("Invalid compat nopage.\n");
 374                 page = NOPAGE_SIGBUS;
 375                 goto out_unlock;
 376         }
 377
 378         ttm = bo->ttm;
 379         drm_ttm_fixup_caching(ttm);
 380         page_offset = (address - vma->vm_start) >> PAGE_SHIFT;
 381         page = drm_ttm_get_page(ttm, page_offset);
 382         if (!page) {
 383                 page = NOPAGE_OOM;
 384                 goto out_unlock;
 385         }
 386
 387         get_page(page);
 388 out_unlock:
 389         mutex_unlock(&bo->mutex);
 390         return page;
 391 }
 392
 393
 394
 395
 396 int drm_bo_map_bound(struct vm_area_struct *vma)
 397 {
 398         struct drm_buffer_object *bo = (struct drm_buffer_object *)vma->vm_private_data;
 399         int ret = 0;
 400         unsigned long bus_base;
 401         unsigned long bus_offset;
 402         unsigned long bus_size;
 403
 404         ret = drm_bo_pci_offset(bo->dev, &bo->mem, &bus_base,
 405                                 &bus_offset, &bus_size);
 406         BUG_ON(ret);
 407
 408         if (bus_size) {
 409                 struct drm_mem_type_manager *man = &bo->dev->bm.man[bo->mem.mem_type];
 410                 unsigned long pfn = (bus_base + bus_offset) >> PAGE_SHIFT;
 411                 pgprot_t pgprot = drm_io_prot(man->drm_bus_maptype, vma);
 412                 ret = io_remap_pfn_range(vma, vma->vm_start, pfn,
 413                                          vma->vm_end - vma->vm_start,
 414                                          pgprot);
 415         }
 416
 417         return ret;
 418 }
 419
 420
 421 int drm_bo_add_vma(struct drm_buffer_object * bo, struct vm_area_struct *vma)
 422 {
 423         p_mm_entry_t *entry, *n_entry;
 424         vma_entry_t *v_entry;
 425         struct mm_struct *mm = vma->vm_mm;
 426
 427         v_entry = drm_ctl_alloc(sizeof(*v_entry), DRM_MEM_BUFOBJ);
 428         if (!v_entry) {
 429                 DRM_ERROR("Allocation of vma pointer entry failed\n");
 430                 return -ENOMEM;
 431         }
 432         v_entry->vma = vma;
 433
 434         list_add_tail(&v_entry->head, &bo->vma_list);
 435
 436         list_for_each_entry(entry, &bo->p_mm_list, head) {
 437                 if (mm == entry->mm) {
 438                         atomic_inc(&entry->refcount);
 439                         return 0;
 440                 } else if ((unsigned long)mm < (unsigned long)entry->mm) ;
 441         }
 442
 443         n_entry = drm_ctl_alloc(sizeof(*n_entry), DRM_MEM_BUFOBJ);
 444         if (!n_entry) {
 445                 DRM_ERROR("Allocation of process mm pointer entry failed\n");
 446                 return -ENOMEM;
 447         }
 448         INIT_LIST_HEAD(&n_entry->head);
 449         n_entry->mm = mm;
 450         n_entry->locked = 0;
 451         atomic_set(&n_entry->refcount, 0);
 452         list_add_tail(&n_entry->head, &entry->head);
 453
 454         return 0;
 455 }
 456
 457 void drm_bo_delete_vma(struct drm_buffer_object * bo, struct vm_area_struct *vma)
 458 {
 459         p_mm_entry_t *entry, *n;
 460         vma_entry_t *v_entry, *v_n;
 461         int found = 0;
 462         struct mm_struct *mm = vma->vm_mm;
 463
 464         list_for_each_entry_safe(v_entry, v_n, &bo->vma_list, head) {
 465                 if (v_entry->vma == vma) {
 466                         found = 1;
 467                         list_del(&v_entry->head);
 468                         drm_ctl_free(v_entry, sizeof(*v_entry), DRM_MEM_BUFOBJ);
 469                         break;
 470                 }
 471         }
 472         BUG_ON(!found);
 473
 474         list_for_each_entry_safe(entry, n, &bo->p_mm_list, head) {
 475                 if (mm == entry->mm) {
 476                         if (atomic_add_negative(-1, &entry->refcount)) {
 477                                 list_del(&entry->head);
 478                                 BUG_ON(entry->locked);
 479                                 drm_ctl_free(entry, sizeof(*entry), DRM_MEM_BUFOBJ);
 480                         }
 481                         return;
 482                 }
 483         }
 484         BUG_ON(1);
 485 }
 486
 487
 488
 489 int drm_bo_lock_kmm(struct drm_buffer_object * bo)
 490 {
 491         p_mm_entry_t *entry;
 492         int lock_ok = 1;
 493
 494         list_for_each_entry(entry, &bo->p_mm_list, head) {
 495                 BUG_ON(entry->locked);
 496                 if (!down_write_trylock(&entry->mm->mmap_sem)) {
 497                         lock_ok = 0;
 498                         break;
 499                 }
 500                 entry->locked = 1;
 501         }
 502
 503         if (lock_ok)
 504                 return 0;
 505
 506         list_for_each_entry(entry, &bo->p_mm_list, head) {
 507                 if (!entry->locked)
 508                         break;
 509                 up_write(&entry->mm->mmap_sem);
 510                 entry->locked = 0;
 511         }
 512
 513         /*
 514          * Possible deadlock. Try again. Our callers should handle this
 515          * and restart.
 516          */
 517
 518         return -EAGAIN;
 519 }
 520
 521 void drm_bo_unlock_kmm(struct drm_buffer_object * bo)
 522 {
 523         p_mm_entry_t *entry;
 524
 525         list_for_each_entry(entry, &bo->p_mm_list, head) {
 526                 BUG_ON(!entry->locked);
 527                 up_write(&entry->mm->mmap_sem);
 528                 entry->locked = 0;
 529         }
 530 }
 531
 532 int drm_bo_remap_bound(struct drm_buffer_object *bo)
 533 {
 534         vma_entry_t *v_entry;
 535         int ret = 0;
 536
 537         if (drm_mem_reg_is_pci(bo->dev, &bo->mem)) {
 538                 list_for_each_entry(v_entry, &bo->vma_list, head) {
 539                         ret = drm_bo_map_bound(v_entry->vma);
 540                         if (ret)
 541                                 break;
 542                 }
 543         }
 544
 545         return ret;
 546 }
 547
 548 void drm_bo_finish_unmap(struct drm_buffer_object *bo)
 549 {
 550         vma_entry_t *v_entry;
 551
 552         list_for_each_entry(v_entry, &bo->vma_list, head) {
 553                 v_entry->vma->vm_flags &= ~VM_PFNMAP;
 554         }
 555 }
 556
 557 #endif
 558
 559 #ifdef DRM_IDR_COMPAT_FN
 560 /* only called when idp->lock is held */
 561 static void __free_layer(struct idr *idp, struct idr_layer *p)
 562 {
 563         p->ary[0] = idp->id_free;
 564         idp->id_free = p;
 565         idp->id_free_cnt++;
 566 }
 567
 568 static void free_layer(struct idr *idp, struct idr_layer *p)
 569 {
 570         unsigned long flags;
 571
 572         /*
 573          * Depends on the return element being zeroed.
 574          */
 575         spin_lock_irqsave(&idp->lock, flags);
 576         __free_layer(idp, p);
 577         spin_unlock_irqrestore(&idp->lock, flags);
 578 }
 579
 580 /**
 581  * idr_for_each - iterate through all stored pointers
 582  * @idp: idr handle
 583  * @fn: function to be called for each pointer
 584  * @data: data passed back to callback function
 585  *
 586  * Iterate over the pointers registered with the given idr.  The
 587  * callback function will be called for each pointer currently
 588  * registered, passing the id, the pointer and the data pointer passed
 589  * to this function.  It is not safe to modify the idr tree while in
 590  * the callback, so functions such as idr_get_new and idr_remove are
 591  * not allowed.
 592  *
 593  * We check the return of @fn each time. If it returns anything other
 594  * than 0, we break out and return that value.
 595  *
 596 * The caller must serialize idr_find() vs idr_get_new() and idr_remove().
 597  */
 598 int idr_for_each(struct idr *idp,
 599                  int (*fn)(int id, void *p, void *data), void *data)
 600 {
 601         int n, id, max, error = 0;
 602         struct idr_layer *p;
 603         struct idr_layer *pa[MAX_LEVEL];
 604         struct idr_layer **paa = &pa[0];
 605
 606         n = idp->layers * IDR_BITS;
 607         p = idp->top;
 608         max = 1 << n;
 609
 610         id = 0;
 611         while (id < max) {
 612                 while (n > 0 && p) {
 613                         n -= IDR_BITS;
 614                         *paa++ = p;
 615                         p = p->ary[(id >> n) & IDR_MASK];
 616                 }
 617
 618                 if (p) {
 619                         error = fn(id, (void *)p, data);
 620                         if (error)
 621                                 break;
 622                 }
 623
 624                 id += 1 << n;
 625                 while (n < fls(id)) {
 626                         n += IDR_BITS;
 627                         p = *--paa;
 628                 }
 629         }
 630
 631         return error;
 632 }
 633 EXPORT_SYMBOL(idr_for_each);
 634
 635 /**
 636  * idr_remove_all - remove all ids from the given idr tree
 637  * @idp: idr handle
 638  *
 639  * idr_destroy() only frees up unused, cached idp_layers, but this
 640  * function will remove all id mappings and leave all idp_layers
 641  * unused.
 642  *
 643  * A typical clean-up sequence for objects stored in an idr tree, will
 644  * use idr_for_each() to free all objects, if necessay, then
 645  * idr_remove_all() to remove all ids, and idr_destroy() to free
 646  * up the cached idr_layers.
 647  */
 648 void idr_remove_all(struct idr *idp)
 649 {
 650        int n, id, max, error = 0;
 651        struct idr_layer *p;
 652        struct idr_layer *pa[MAX_LEVEL];
 653        struct idr_layer **paa = &pa[0];
 654
 655        n = idp->layers * IDR_BITS;
 656        p = idp->top;
 657        max = 1 << n;
 658
 659        id = 0;
 660        while (id < max && !error) {
 661                while (n > IDR_BITS && p) {
 662                        n -= IDR_BITS;
 663                        *paa++ = p;
 664                        p = p->ary[(id >> n) & IDR_MASK];
 665                }
 666
 667                id += 1 << n;
 668                while (n < fls(id)) {
 669                        if (p) {
 670                                memset(p, 0, sizeof *p);
 671                                free_layer(idp, p);
 672                        }
 673                        n += IDR_BITS;
 674                        p = *--paa;
 675                }
 676        }
 677        idp->top = NULL;
 678        idp->layers = 0;
 679 }
 680 EXPORT_SYMBOL(idr_remove_all);
 681 #endif