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                 goto no_refresh;
 150
 151         for (i = 0; i < nr_pages; i++) {
 152                 dma_update_cpu_trans(zdev, page_addr, dma_addr, flags);
 153                 page_addr += PAGE_SIZE;
 154                 dma_addr += PAGE_SIZE;
 155         }
 156
 157         /*
 158          * rpcit is not required to establish new translations when previously
 159          * invalid translation-table entries are validated, however it is
 160          * required when altering previously valid entries.
 161          */
 162         if (!zdev->tlb_refresh &&
 163             ((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID))
 164                 /*
 165                  * TODO: also need to check that the old entry is indeed INVALID
 166                  * and not only for one page but for the whole range...
 167                  * -> now we WARN_ON in that case but with lazy unmap that
 168                  * needs to be redone!
 169                  */
 170                 goto no_refresh;
 171
 172         rc = zpci_refresh_trans((u64) zdev->fh << 32, start_dma_addr,
 173                                 nr_pages * PAGE_SIZE);
 174
 175 no_refresh:
 176         spin_unlock_irqrestore(&zdev->dma_table_lock, irq_flags);
 177         return rc;
 178 }
 179
 180 static void dma_free_seg_table(unsigned long entry)
 181 {
 182         unsigned long *sto = get_rt_sto(entry);
 183         int sx;
 184
 185         for (sx = 0; sx < ZPCI_TABLE_ENTRIES; sx++)
 186                 if (reg_entry_isvalid(sto[sx]))
 187                         dma_free_page_table(get_st_pto(sto[sx]));
 188
 189         dma_free_cpu_table(sto);
 190 }
 191
 192 static void dma_cleanup_tables(struct zpci_dev *zdev)
 193 {
 194         unsigned long *table;
 195         int rtx;
 196
 197         if (!zdev || !zdev->dma_table)
 198                 return;
 199
 200         table = zdev->dma_table;
 201         for (rtx = 0; rtx < ZPCI_TABLE_ENTRIES; rtx++)
 202                 if (reg_entry_isvalid(table[rtx]))
 203                         dma_free_seg_table(table[rtx]);
 204
 205         dma_free_cpu_table(table);
 206         zdev->dma_table = NULL;
 207 }
 208
 209 static unsigned long __dma_alloc_iommu(struct zpci_dev *zdev,
 210                                        unsigned long start, int size)
 211 {
 212         unsigned long boundary_size;
 213
 214         boundary_size = ALIGN(dma_get_seg_boundary(&zdev->pdev->dev) + 1,
 215                               PAGE_SIZE) >> PAGE_SHIFT;
 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                 goto out_free;
 285
 286         if (direction == DMA_NONE || direction == DMA_TO_DEVICE)
 287                 flags |= ZPCI_TABLE_PROTECTED;
 288
 289         if (!dma_update_trans(zdev, pa, dma_addr, size, flags)) {
 290                 atomic64_add(nr_pages, &zdev->fmb->mapped_pages);
 291                 return dma_addr + (offset & ~PAGE_MASK);
 292         }
 293
 294 out_free:
 295         dma_free_iommu(zdev, iommu_page_index, nr_pages);
 296 out_err:
 297         zpci_err("map error:\n");
 298         zpci_err_hex(&pa, sizeof(pa));
 299         return DMA_ERROR_CODE;
 300 }
 301
 302 static void s390_dma_unmap_pages(struct device *dev, dma_addr_t dma_addr,
 303                                  size_t size, enum dma_data_direction direction,
 304                                  struct dma_attrs *attrs)
 305 {
 306         struct zpci_dev *zdev = get_zdev(to_pci_dev(dev));
 307         unsigned long iommu_page_index;
 308         int npages;
 309
 310         npages = iommu_num_pages(dma_addr, size, PAGE_SIZE);
 311         dma_addr = dma_addr & PAGE_MASK;
 312         if (dma_update_trans(zdev, 0, dma_addr, npages * PAGE_SIZE,
 313                              ZPCI_TABLE_PROTECTED | ZPCI_PTE_INVALID)) {
 314                 zpci_err("unmap error:\n");
 315                 zpci_err_hex(&dma_addr, sizeof(dma_addr));
 316         }
 317
 318         atomic64_add(npages, &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         pa = page_to_phys(page);
 338         memset((void *) pa, 0, size);
 339
 340         map = s390_dma_map_pages(dev, page, pa % PAGE_SIZE,
 341                                  size, DMA_BIDIRECTIONAL, NULL);
 342         if (dma_mapping_error(dev, map)) {
 343                 free_pages(pa, get_order(size));
 344                 return NULL;
 345         }
 346
 347         atomic64_add(size / PAGE_SIZE, &zdev->fmb->allocated_pages);
 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         struct zpci_dev *zdev = get_zdev(to_pci_dev(dev));
 358
 359         size = PAGE_ALIGN(size);
 360         atomic64_sub(size / PAGE_SIZE, &zdev->fmb->allocated_pages);
 361         s390_dma_unmap_pages(dev, dma_handle, size, DMA_BIDIRECTIONAL, NULL);
 362         free_pages((unsigned long) pa, get_order(size));
 363 }
 364
 365 static int s390_dma_map_sg(struct device *dev, struct scatterlist *sg,
 366                            int nr_elements, enum dma_data_direction dir,
 367                            struct dma_attrs *attrs)
 368 {
 369         int mapped_elements = 0;
 370         struct scatterlist *s;
 371         int i;
 372
 373         for_each_sg(sg, s, nr_elements, i) {
 374                 struct page *page = sg_page(s);
 375                 s->dma_address = s390_dma_map_pages(dev, page, s->offset,
 376                                                     s->length, dir, NULL);
 377                 if (!dma_mapping_error(dev, s->dma_address)) {
 378                         s->dma_length = s->length;
 379                         mapped_elements++;
 380                 } else
 381                         goto unmap;
 382         }
 383 out:
 384         return mapped_elements;
 385
 386 unmap:
 387         for_each_sg(sg, s, mapped_elements, i) {
 388                 if (s->dma_address)
 389                         s390_dma_unmap_pages(dev, s->dma_address, s->dma_length,
 390                                              dir, NULL);
 391                 s->dma_address = 0;
 392                 s->dma_length = 0;
 393         }
 394         mapped_elements = 0;
 395         goto out;
 396 }
 397
 398 static void s390_dma_unmap_sg(struct device *dev, struct scatterlist *sg,
 399                               int nr_elements, enum dma_data_direction dir,
 400                               struct dma_attrs *attrs)
 401 {
 402         struct scatterlist *s;
 403         int i;
 404
 405         for_each_sg(sg, s, nr_elements, i) {
 406                 s390_dma_unmap_pages(dev, s->dma_address, s->dma_length, dir, NULL);
 407                 s->dma_address = 0;
 408                 s->dma_length = 0;
 409         }
 410 }
 411
 412 int zpci_dma_init_device(struct zpci_dev *zdev)
 413 {
 414         int rc;
 415
 416         spin_lock_init(&zdev->iommu_bitmap_lock);
 417         spin_lock_init(&zdev->dma_table_lock);
 418
 419         zdev->dma_table = dma_alloc_cpu_table();
 420         if (!zdev->dma_table) {
 421                 rc = -ENOMEM;
 422                 goto out_clean;
 423         }
 424
 425         zdev->iommu_size = (unsigned long) high_memory - PAGE_OFFSET;
 426         zdev->iommu_pages = zdev->iommu_size >> PAGE_SHIFT;
 427         zdev->iommu_bitmap = vzalloc(zdev->iommu_pages / 8);
 428         if (!zdev->iommu_bitmap) {
 429                 rc = -ENOMEM;
 430                 goto out_reg;
 431         }
 432
 433         rc = zpci_register_ioat(zdev,
 434                                 0,
 435                                 zdev->start_dma + PAGE_OFFSET,
 436                                 zdev->start_dma + zdev->iommu_size - 1,
 437                                 (u64) zdev->dma_table);
 438         if (rc)
 439                 goto out_reg;
 440         return 0;
 441
 442 out_reg:
 443         dma_free_cpu_table(zdev->dma_table);
 444 out_clean:
 445         return rc;
 446 }
 447
 448 void zpci_dma_exit_device(struct zpci_dev *zdev)
 449 {
 450         zpci_unregister_ioat(zdev, 0);
 451         dma_cleanup_tables(zdev);
 452         vfree(zdev->iommu_bitmap);
 453         zdev->iommu_bitmap = NULL;
 454         zdev->next_bit = 0;
 455 }
 456
 457 static int __init dma_alloc_cpu_table_caches(void)
 458 {
 459         dma_region_table_cache = kmem_cache_create("PCI_DMA_region_tables",
 460                                         ZPCI_TABLE_SIZE, ZPCI_TABLE_ALIGN,
 461                                         0, NULL);
 462         if (!dma_region_table_cache)
 463                 return -ENOMEM;
 464
 465         dma_page_table_cache = kmem_cache_create("PCI_DMA_page_tables",
 466                                         ZPCI_PT_SIZE, ZPCI_PT_ALIGN,
 467                                         0, NULL);
 468         if (!dma_page_table_cache) {
 469                 kmem_cache_destroy(dma_region_table_cache);
 470                 return -ENOMEM;
 471         }
 472         return 0;
 473 }
 474
 475 int __init zpci_dma_init(void)
 476 {
 477         return dma_alloc_cpu_table_caches();
 478 }
 479
 480 void zpci_dma_exit(void)
 481 {
 482         kmem_cache_destroy(dma_page_table_cache);
 483         kmem_cache_destroy(dma_region_table_cache);
 484 }
 485
 486 #define PREALLOC_DMA_DEBUG_ENTRIES      (1 << 16)
 487
 488 static int __init dma_debug_do_init(void)
 489 {
 490         dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
 491         return 0;
 492 }
 493 fs_initcall(dma_debug_do_init);
 494
 495 struct dma_map_ops s390_dma_ops = {
 496         .alloc          = s390_dma_alloc,
 497         .free           = s390_dma_free,
 498         .map_sg         = s390_dma_map_sg,
 499         .unmap_sg       = s390_dma_unmap_sg,
 500         .map_page       = s390_dma_map_pages,
 501         .unmap_page     = s390_dma_unmap_pages,
 502         /* if we support direct DMA this must be conditional */
 503         .is_phys        = 0,
 504         /* dma_supported is unconditionally true without a callback */
 505 };
 506 EXPORT_SYMBOL_GPL(s390_dma_ops);