arch/s390/pci/pci_dma.c

   1 /*
   2  * Copyright IBM Corp. 2012
   3  *
   4  * Author(s):
   5  *   Jan Glauber <jang@linux.vnet.ibm.com>
   6  */
   7
   8 #include <linux/kernel.h>
   9 #include <linux/slab.h>
  10 #include <linux/export.h>
  11 #include <linux/iommu-helper.h>
  12 #include <linux/dma-mapping.h>
  13 #include <linux/vmalloc.h>
  14 #include <linux/pci.h>
  15 #include <asm/pci_dma.h>
  16
  17 static struct kmem_cache *dma_region_table_cache;
  18 static struct kmem_cache *dma_page_table_cache;
  19
  20 static unsigned long *dma_alloc_cpu_table(void)
  21 {
  22         unsigned long *table, *entry;
  23
  24         table = kmem_cache_alloc(dma_region_table_cache, GFP_ATOMIC);
  25         if (!table)
  26                 return NULL;
  27
  28         for (entry = table; entry < table + ZPCI_TABLE_ENTRIES; entry++)
  29                 *entry = ZPCI_TABLE_INVALID | ZPCI_TABLE_PROTECTED;
  30         return table;
  31 }
  32
  33 static void dma_free_cpu_table(void *table)
  34 {
  35         kmem_cache_free(dma_region_table_cache, table);
  36 }
  37
  38 static unsigned long *dma_alloc_page_table(void)
  39 {
  40         unsigned long *table, *entry;
  41
  42         table = kmem_cache_alloc(dma_page_table_cache, GFP_ATOMIC);
  43         if (!table)
  44                 return NULL;
  45
  46         for (entry = table; entry < table + ZPCI_PT_ENTRIES; entry++)
  47                 *entry = ZPCI_PTE_INVALID | ZPCI_TABLE_PROTECTED;
  48         return table;
  49 }
  50
  51 static void dma_free_page_table(void *table)
  52 {
  53         kmem_cache_free(dma_page_table_cache, table);
  54 }
  55
  56 static unsigned long *dma_get_seg_table_origin(unsigned long *entry)
  57 {
  58         unsigned long *sto;
  59
  60         if (reg_entry_isvalid(*entry))
  61                 sto = get_rt_sto(*entry);
  62         else {
  63                 sto = dma_alloc_cpu_table();
  64                 if (!sto)
  65                         return NULL;
  66
  67                 set_rt_sto(entry, sto);
  68                 validate_rt_entry(entry);
  69                 entry_clr_protected(entry);
  70         }
  71         return sto;
  72 }
  73
  74 static unsigned long *dma_get_page_table_origin(unsigned long *entry)
  75 {
  76         unsigned long *pto;
  77
  78         if (reg_entry_isvalid(*entry))
  79                 pto = get_st_pto(*entry);
  80         else {
  81                 pto = dma_alloc_page_table();
  82                 if (!pto)
  83                         return NULL;
  84                 set_st_pto(entry, pto);
  85                 validate_st_entry(entry);
  86                 entry_clr_protected(entry);
  87         }
  88         return pto;
  89 }
  90
  91 static unsigned long *dma_walk_cpu_trans(unsigned long *rto, dma_addr_t dma_addr)
  92 {
  93         unsigned long *sto, *pto;
  94         unsigned int rtx, sx, px;
  95
  96         rtx = calc_rtx(dma_addr);
  97         sto = dma_get_seg_table_origin(&rto[rtx]);
  98         if (!sto)
  99                 return NULL;
 100
 101         sx = calc_sx(dma_addr);
 102         pto = dma_get_page_table_origin(&sto[sx]);
 103         if (!pto)
 104                 return NULL;
 105
 106         px = calc_px(dma_addr);
 107         return &pto[px];
 108 }
 109
 110 static void dma_update_cpu_trans(struct zpci_dev *zdev, void *page_addr,
 111                                  dma_addr_t dma_addr, int flags)
 112 {
 113         unsigned long *entry;
 114
 115         entry = dma_walk_cpu_trans(zdev->dma_table, dma_addr);
 116         if (!entry) {
 117                 WARN_ON_ONCE(1);
 118                 return;
 119         }
 120
 121         if (flags & ZPCI_PTE_INVALID) {
 122                 invalidate_pt_entry(entry);
 123                 return;
 124         } else {
 125                 set_pt_pfaa(entry, page_addr);
 126                 validate_pt_entry(entry);
 127         }
 128
 129         if (flags & ZPCI_TABLE_PROTECTED)
 130                 entry_set_protected(entry);
 131         else
 132                 entry_clr_protected(entry);
 133 }
 134
 135 static int dma_update_trans(struct zpci_dev *zdev, unsigned long pa,
 136                             dma_addr_t dma_addr, size_t size, int flags)
 137 {
 138         unsigned int nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
 139         u8 *page_addr = (u8 *) (pa & PAGE_MASK);
 140         dma_addr_t start_dma_addr = dma_addr;
 141         unsigned long irq_flags;
 142         int i, rc = 0;
 143
 144         if (!nr_pages)
 145                 return -EINVAL;
 146
 147         spin_lock_irqsave(&zdev->dma_table_lock, irq_flags);
 148         if (!zdev->dma_table) {
 149                 dev_err(&zdev->pdev->dev, "Missing DMA table\n");
 150                 goto no_refresh;
 151         }
 152
 153         for (i = 0; i < nr_pages; i++) {
 154                 dma_update_cpu_trans(zdev, page_addr, dma_addr, flags);
 155                 page_addr += PAGE_SIZE;
 156                 dma_addr += PAGE_SIZE;
 157         }
 158
 159         /*
 160          * rpcit is not required to establish new translations when previously
 161          * invalid translation-table entries are validated, however it is
 162          * required when altering previously valid entries.
 163          */
 164         if (!zdev->tlb_refresh &&
 165             ((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID))
 166                 /*
 167                  * TODO: also need to check that the old entry is indeed INVALID
 168                  * and not only for one page but for the whole range...
 169                  * -> now we WARN_ON in that case but with lazy unmap that
 170                  * needs to be redone!
 171                  */
 172                 goto no_refresh;
 173
 174         rc = zpci_refresh_trans((u64) zdev->fh << 32, start_dma_addr,
 175                                 nr_pages * PAGE_SIZE);
 176
 177 no_refresh:
 178         spin_unlock_irqrestore(&zdev->dma_table_lock, irq_flags);
 179         return rc;
 180 }
 181
 182 static void dma_free_seg_table(unsigned long entry)
 183 {
 184         unsigned long *sto = get_rt_sto(entry);
 185         int sx;
 186
 187         for (sx = 0; sx < ZPCI_TABLE_ENTRIES; sx++)
 188                 if (reg_entry_isvalid(sto[sx]))
 189                         dma_free_page_table(get_st_pto(sto[sx]));
 190
 191         dma_free_cpu_table(sto);
 192 }
 193
 194 static void dma_cleanup_tables(struct zpci_dev *zdev)
 195 {
 196         unsigned long *table;
 197         int rtx;
 198
 199         if (!zdev || !zdev->dma_table)
 200                 return;
 201
 202         table = zdev->dma_table;
 203         for (rtx = 0; rtx < ZPCI_TABLE_ENTRIES; rtx++)
 204                 if (reg_entry_isvalid(table[rtx]))
 205                         dma_free_seg_table(table[rtx]);
 206
 207         dma_free_cpu_table(table);
 208         zdev->dma_table = NULL;
 209 }
 210
 211 static unsigned long __dma_alloc_iommu(struct zpci_dev *zdev, unsigned long start,
 212                                    int size)
 213 {
 214         unsigned long boundary_size = 0x1000000;
 215
 216         return iommu_area_alloc(zdev->iommu_bitmap, zdev->iommu_pages,
 217                                 start, size, 0, boundary_size, 0);
 218 }
 219
 220 static unsigned long dma_alloc_iommu(struct zpci_dev *zdev, int size)
 221 {
 222         unsigned long offset, flags;
 223
 224         spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags);
 225         offset = __dma_alloc_iommu(zdev, zdev->next_bit, size);
 226         if (offset == -1)
 227                 offset = __dma_alloc_iommu(zdev, 0, size);
 228
 229         if (offset != -1) {
 230                 zdev->next_bit = offset + size;
 231                 if (zdev->next_bit >= zdev->iommu_pages)
 232                         zdev->next_bit = 0;
 233         }
 234         spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
 235         return offset;
 236 }
 237
 238 static void dma_free_iommu(struct zpci_dev *zdev, unsigned long offset, int size)
 239 {
 240         unsigned long flags;
 241
 242         spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags);
 243         if (!zdev->iommu_bitmap)
 244                 goto out;
 245         bitmap_clear(zdev->iommu_bitmap, offset, size);
 246         if (offset >= zdev->next_bit)
 247                 zdev->next_bit = offset + size;
 248 out:
 249         spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
 250 }
 251
 252 int dma_set_mask(struct device *dev, u64 mask)
 253 {
 254         if (!dev->dma_mask || !dma_supported(dev, mask))
 255                 return -EIO;
 256
 257         *dev->dma_mask = mask;
 258         return 0;
 259 }
 260 EXPORT_SYMBOL_GPL(dma_set_mask);
 261
 262 static dma_addr_t s390_dma_map_pages(struct device *dev, struct page *page,
 263                                      unsigned long offset, size_t size,
 264                                      enum dma_data_direction direction,
 265                                      struct dma_attrs *attrs)
 266 {
 267         struct zpci_dev *zdev = get_zdev(to_pci_dev(dev));
 268         unsigned long nr_pages, iommu_page_index;
 269         unsigned long pa = page_to_phys(page) + offset;
 270         int flags = ZPCI_PTE_VALID;
 271         dma_addr_t dma_addr;
 272
 273         /* This rounds up number of pages based on size and offset */
 274         nr_pages = iommu_num_pages(pa, size, PAGE_SIZE);
 275         iommu_page_index = dma_alloc_iommu(zdev, nr_pages);
 276         if (iommu_page_index == -1)
 277                 goto out_err;
 278
 279         /* Use rounded up size */
 280         size = nr_pages * PAGE_SIZE;
 281
 282         dma_addr = zdev->start_dma + iommu_page_index * PAGE_SIZE;
 283         if (dma_addr + size > zdev->end_dma) {
 284                 dev_err(dev, "(dma_addr: 0x%16.16LX + size: 0x%16.16lx) > end_dma: 0x%16.16Lx\n",
 285                          dma_addr, size, zdev->end_dma);
 286                 goto out_free;
 287         }
 288
 289         if (direction == DMA_NONE || direction == DMA_TO_DEVICE)
 290                 flags |= ZPCI_TABLE_PROTECTED;
 291
 292         if (!dma_update_trans(zdev, pa, dma_addr, size, flags)) {
 293                 atomic64_add(nr_pages, (atomic64_t *) &zdev->fmb->mapped_pages);
 294                 return dma_addr + (offset & ~PAGE_MASK);
 295         }
 296
 297 out_free:
 298         dma_free_iommu(zdev, iommu_page_index, nr_pages);
 299 out_err:
 300         dev_err(dev, "Failed to map addr: %lx\n", pa);
 301         return DMA_ERROR_CODE;
 302 }
 303
 304 static void s390_dma_unmap_pages(struct device *dev, dma_addr_t dma_addr,
 305                                  size_t size, enum dma_data_direction direction,
 306                                  struct dma_attrs *attrs)
 307 {
 308         struct zpci_dev *zdev = get_zdev(to_pci_dev(dev));
 309         unsigned long iommu_page_index;
 310         int npages;
 311
 312         npages = iommu_num_pages(dma_addr, size, PAGE_SIZE);
 313         dma_addr = dma_addr & PAGE_MASK;
 314         if (dma_update_trans(zdev, 0, dma_addr, npages * PAGE_SIZE,
 315                              ZPCI_TABLE_PROTECTED | ZPCI_PTE_INVALID))
 316                 dev_err(dev, "Failed to unmap addr: %Lx\n", dma_addr);
 317
 318         atomic64_add(npages, (atomic64_t *) &zdev->fmb->unmapped_pages);
 319         iommu_page_index = (dma_addr - zdev->start_dma) >> PAGE_SHIFT;
 320         dma_free_iommu(zdev, iommu_page_index, npages);
 321 }
 322
 323 static void *s390_dma_alloc(struct device *dev, size_t size,
 324                             dma_addr_t *dma_handle, gfp_t flag,
 325                             struct dma_attrs *attrs)
 326 {
 327         struct zpci_dev *zdev = get_zdev(to_pci_dev(dev));
 328         struct page *page;
 329         unsigned long pa;
 330         dma_addr_t map;
 331
 332         size = PAGE_ALIGN(size);
 333         page = alloc_pages(flag, get_order(size));
 334         if (!page)
 335                 return NULL;
 336
 337         atomic64_add(size / PAGE_SIZE, (atomic64_t *) &zdev->fmb->allocated_pages);
 338         pa = page_to_phys(page);
 339         memset((void *) pa, 0, size);
 340
 341         map = s390_dma_map_pages(dev, page, pa % PAGE_SIZE,
 342                                  size, DMA_BIDIRECTIONAL, NULL);
 343         if (dma_mapping_error(dev, map)) {
 344                 free_pages(pa, get_order(size));
 345                 return NULL;
 346         }
 347
 348         if (dma_handle)
 349                 *dma_handle = map;
 350         return (void *) pa;
 351 }
 352
 353 static void s390_dma_free(struct device *dev, size_t size,
 354                           void *pa, dma_addr_t dma_handle,
 355                           struct dma_attrs *attrs)
 356 {
 357         s390_dma_unmap_pages(dev, dma_handle, PAGE_ALIGN(size),
 358                              DMA_BIDIRECTIONAL, NULL);
 359         free_pages((unsigned long) pa, get_order(size));
 360 }
 361
 362 static int s390_dma_map_sg(struct device *dev, struct scatterlist *sg,
 363                            int nr_elements, enum dma_data_direction dir,
 364                            struct dma_attrs *attrs)
 365 {
 366         int mapped_elements = 0;
 367         struct scatterlist *s;
 368         int i;
 369
 370         for_each_sg(sg, s, nr_elements, i) {
 371                 struct page *page = sg_page(s);
 372                 s->dma_address = s390_dma_map_pages(dev, page, s->offset,
 373                                                     s->length, dir, NULL);
 374                 if (!dma_mapping_error(dev, s->dma_address)) {
 375                         s->dma_length = s->length;
 376                         mapped_elements++;
 377                 } else
 378                         goto unmap;
 379         }
 380 out:
 381         return mapped_elements;
 382
 383 unmap:
 384         for_each_sg(sg, s, mapped_elements, i) {
 385                 if (s->dma_address)
 386                         s390_dma_unmap_pages(dev, s->dma_address, s->dma_length,
 387                                              dir, NULL);
 388                 s->dma_address = 0;
 389                 s->dma_length = 0;
 390         }
 391         mapped_elements = 0;
 392         goto out;
 393 }
 394
 395 static void s390_dma_unmap_sg(struct device *dev, struct scatterlist *sg,
 396                               int nr_elements, enum dma_data_direction dir,
 397                               struct dma_attrs *attrs)
 398 {
 399         struct scatterlist *s;
 400         int i;
 401
 402         for_each_sg(sg, s, nr_elements, i) {
 403                 s390_dma_unmap_pages(dev, s->dma_address, s->dma_length, dir, NULL);
 404                 s->dma_address = 0;
 405                 s->dma_length = 0;
 406         }
 407 }
 408
 409 int zpci_dma_init_device(struct zpci_dev *zdev)
 410 {
 411         int rc;
 412
 413         spin_lock_init(&zdev->iommu_bitmap_lock);
 414         spin_lock_init(&zdev->dma_table_lock);
 415
 416         zdev->dma_table = dma_alloc_cpu_table();
 417         if (!zdev->dma_table) {
 418                 rc = -ENOMEM;
 419                 goto out_clean;
 420         }
 421
 422         zdev->iommu_size = (unsigned long) high_memory - PAGE_OFFSET;
 423         zdev->iommu_pages = zdev->iommu_size >> PAGE_SHIFT;
 424         zdev->iommu_bitmap = vzalloc(zdev->iommu_pages / 8);
 425         if (!zdev->iommu_bitmap) {
 426                 rc = -ENOMEM;
 427                 goto out_reg;
 428         }
 429
 430         rc = zpci_register_ioat(zdev,
 431                                 0,
 432                                 zdev->start_dma + PAGE_OFFSET,
 433                                 zdev->start_dma + zdev->iommu_size - 1,
 434                                 (u64) zdev->dma_table);
 435         if (rc)
 436                 goto out_reg;
 437         return 0;
 438
 439 out_reg:
 440         dma_free_cpu_table(zdev->dma_table);
 441 out_clean:
 442         return rc;
 443 }
 444
 445 void zpci_dma_exit_device(struct zpci_dev *zdev)
 446 {
 447         zpci_unregister_ioat(zdev, 0);
 448         dma_cleanup_tables(zdev);
 449         vfree(zdev->iommu_bitmap);
 450         zdev->iommu_bitmap = NULL;
 451         zdev->next_bit = 0;
 452 }
 453
 454 static int __init dma_alloc_cpu_table_caches(void)
 455 {
 456         dma_region_table_cache = kmem_cache_create("PCI_DMA_region_tables",
 457                                         ZPCI_TABLE_SIZE, ZPCI_TABLE_ALIGN,
 458                                         0, NULL);
 459         if (!dma_region_table_cache)
 460                 return -ENOMEM;
 461
 462         dma_page_table_cache = kmem_cache_create("PCI_DMA_page_tables",
 463                                         ZPCI_PT_SIZE, ZPCI_PT_ALIGN,
 464                                         0, NULL);
 465         if (!dma_page_table_cache) {
 466                 kmem_cache_destroy(dma_region_table_cache);
 467                 return -ENOMEM;
 468         }
 469         return 0;
 470 }
 471
 472 int __init zpci_dma_init(void)
 473 {
 474         return dma_alloc_cpu_table_caches();
 475 }
 476
 477 void zpci_dma_exit(void)
 478 {
 479         kmem_cache_destroy(dma_page_table_cache);
 480         kmem_cache_destroy(dma_region_table_cache);
 481 }
 482
 483 #define PREALLOC_DMA_DEBUG_ENTRIES      (1 << 16)
 484
 485 static int __init dma_debug_do_init(void)
 486 {
 487         dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
 488         return 0;
 489 }
 490 fs_initcall(dma_debug_do_init);
 491
 492 struct dma_map_ops s390_dma_ops = {
 493         .alloc          = s390_dma_alloc,
 494         .free           = s390_dma_free,
 495         .map_sg         = s390_dma_map_sg,
 496         .unmap_sg       = s390_dma_unmap_sg,
 497         .map_page       = s390_dma_map_pages,
 498         .unmap_page     = s390_dma_unmap_pages,
 499         /* if we support direct DMA this must be conditional */
 500         .is_phys        = 0,
 501         /* dma_supported is unconditionally true without a callback */
 502 };
 503 EXPORT_SYMBOL_GPL(s390_dma_ops);