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/pci.h>
  14 #include <asm/pci_dma.h>
  15
  16 static struct kmem_cache *dma_region_table_cache;
  17 static struct kmem_cache *dma_page_table_cache;
  18
  19 static unsigned long *dma_alloc_cpu_table(void)
  20 {
  21         unsigned long *table, *entry;
  22
  23         table = kmem_cache_alloc(dma_region_table_cache, GFP_ATOMIC);
  24         if (!table)
  25                 return NULL;
  26
  27         for (entry = table; entry < table + ZPCI_TABLE_ENTRIES; entry++)
  28                 *entry = ZPCI_TABLE_INVALID | ZPCI_TABLE_PROTECTED;
  29         return table;
  30 }
  31
  32 static void dma_free_cpu_table(void *table)
  33 {
  34         kmem_cache_free(dma_region_table_cache, table);
  35 }
  36
  37 static unsigned long *dma_alloc_page_table(void)
  38 {
  39         unsigned long *table, *entry;
  40
  41         table = kmem_cache_alloc(dma_page_table_cache, GFP_ATOMIC);
  42         if (!table)
  43                 return NULL;
  44
  45         for (entry = table; entry < table + ZPCI_PT_ENTRIES; entry++)
  46                 *entry = ZPCI_PTE_INVALID | ZPCI_TABLE_PROTECTED;
  47         return table;
  48 }
  49
  50 static void dma_free_page_table(void *table)
  51 {
  52         kmem_cache_free(dma_page_table_cache, table);
  53 }
  54
  55 static unsigned long *dma_get_seg_table_origin(unsigned long *entry)
  56 {
  57         unsigned long *sto;
  58
  59         if (reg_entry_isvalid(*entry))
  60                 sto = get_rt_sto(*entry);
  61         else {
  62                 sto = dma_alloc_cpu_table();
  63                 if (!sto)
  64                         return NULL;
  65
  66                 set_rt_sto(entry, sto);
  67                 validate_rt_entry(entry);
  68                 entry_clr_protected(entry);
  69         }
  70         return sto;
  71 }
  72
  73 static unsigned long *dma_get_page_table_origin(unsigned long *entry)
  74 {
  75         unsigned long *pto;
  76
  77         if (reg_entry_isvalid(*entry))
  78                 pto = get_st_pto(*entry);
  79         else {
  80                 pto = dma_alloc_page_table();
  81                 if (!pto)
  82                         return NULL;
  83                 set_st_pto(entry, pto);
  84                 validate_st_entry(entry);
  85                 entry_clr_protected(entry);
  86         }
  87         return pto;
  88 }
  89
  90 static unsigned long *dma_walk_cpu_trans(unsigned long *rto, dma_addr_t dma_addr)
  91 {
  92         unsigned long *sto, *pto;
  93         unsigned int rtx, sx, px;
  94
  95         rtx = calc_rtx(dma_addr);
  96         sto = dma_get_seg_table_origin(&rto[rtx]);
  97         if (!sto)
  98                 return NULL;
  99
 100         sx = calc_sx(dma_addr);
 101         pto = dma_get_page_table_origin(&sto[sx]);
 102         if (!pto)
 103                 return NULL;
 104
 105         px = calc_px(dma_addr);
 106         return &pto[px];
 107 }
 108
 109 static void dma_update_cpu_trans(struct zpci_dev *zdev, void *page_addr,
 110                                  dma_addr_t dma_addr, int flags)
 111 {
 112         unsigned long *entry;
 113
 114         entry = dma_walk_cpu_trans(zdev->dma_table, dma_addr);
 115         if (!entry) {
 116                 WARN_ON_ONCE(1);
 117                 return;
 118         }
 119
 120         if (flags & ZPCI_PTE_INVALID) {
 121                 invalidate_pt_entry(entry);
 122                 return;
 123         } else {
 124                 set_pt_pfaa(entry, page_addr);
 125                 validate_pt_entry(entry);
 126         }
 127
 128         if (flags & ZPCI_TABLE_PROTECTED)
 129                 entry_set_protected(entry);
 130         else
 131                 entry_clr_protected(entry);
 132 }
 133
 134 static int dma_update_trans(struct zpci_dev *zdev, unsigned long pa,
 135                             dma_addr_t dma_addr, size_t size, int flags)
 136 {
 137         unsigned int nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
 138         u8 *page_addr = (u8 *) (pa & PAGE_MASK);
 139         dma_addr_t start_dma_addr = dma_addr;
 140         unsigned long irq_flags;
 141         int i, rc = 0;
 142
 143         if (!nr_pages)
 144                 return -EINVAL;
 145
 146         spin_lock_irqsave(&zdev->dma_table_lock, irq_flags);
 147         if (!zdev->dma_table) {
 148                 dev_err(&zdev->pdev->dev, "Missing DMA table\n");
 149                 goto no_refresh;
 150         }
 151
 152         for (i = 0; i < nr_pages; i++) {
 153                 dma_update_cpu_trans(zdev, page_addr, dma_addr, flags);
 154                 page_addr += PAGE_SIZE;
 155                 dma_addr += PAGE_SIZE;
 156         }
 157
 158         /*
 159          * rpcit is not required to establish new translations when previously
 160          * invalid translation-table entries are validated, however it is
 161          * required when altering previously valid entries.
 162          */
 163         if (!zdev->tlb_refresh &&
 164             ((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID))
 165                 /*
 166                  * TODO: also need to check that the old entry is indeed INVALID
 167                  * and not only for one page but for the whole range...
 168                  * -> now we WARN_ON in that case but with lazy unmap that
 169                  * needs to be redone!
 170                  */
 171                 goto no_refresh;
 172
 173         rc = s390pci_refresh_trans((u64) zdev->fh << 32, start_dma_addr,
 174                                    nr_pages * PAGE_SIZE);
 175
 176 no_refresh:
 177         spin_unlock_irqrestore(&zdev->dma_table_lock, irq_flags);
 178         return rc;
 179 }
 180
 181 static void dma_free_seg_table(unsigned long entry)
 182 {
 183         unsigned long *sto = get_rt_sto(entry);
 184         int sx;
 185
 186         for (sx = 0; sx < ZPCI_TABLE_ENTRIES; sx++)
 187                 if (reg_entry_isvalid(sto[sx]))
 188                         dma_free_page_table(get_st_pto(sto[sx]));
 189
 190         dma_free_cpu_table(sto);
 191 }
 192
 193 static void dma_cleanup_tables(struct zpci_dev *zdev)
 194 {
 195         unsigned long *table;
 196         int rtx;
 197
 198         if (!zdev || !zdev->dma_table)
 199                 return;
 200
 201         table = zdev->dma_table;
 202         for (rtx = 0; rtx < ZPCI_TABLE_ENTRIES; rtx++)
 203                 if (reg_entry_isvalid(table[rtx]))
 204                         dma_free_seg_table(table[rtx]);
 205
 206         dma_free_cpu_table(table);
 207         zdev->dma_table = NULL;
 208 }
 209
 210 static unsigned long __dma_alloc_iommu(struct zpci_dev *zdev, unsigned long start,
 211                                    int size)
 212 {
 213         unsigned long boundary_size = 0x1000000;
 214
 215         return iommu_area_alloc(zdev->iommu_bitmap, zdev->iommu_pages,
 216                                 start, size, 0, boundary_size, 0);
 217 }
 218
 219 static unsigned long dma_alloc_iommu(struct zpci_dev *zdev, int size)
 220 {
 221         unsigned long offset, flags;
 222
 223         spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags);
 224         offset = __dma_alloc_iommu(zdev, zdev->next_bit, size);
 225         if (offset == -1)
 226                 offset = __dma_alloc_iommu(zdev, 0, size);
 227
 228         if (offset != -1) {
 229                 zdev->next_bit = offset + size;
 230                 if (zdev->next_bit >= zdev->iommu_pages)
 231                         zdev->next_bit = 0;
 232         }
 233         spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
 234         return offset;
 235 }
 236
 237 static void dma_free_iommu(struct zpci_dev *zdev, unsigned long offset, int size)
 238 {
 239         unsigned long flags;
 240
 241         spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags);
 242         if (!zdev->iommu_bitmap)
 243                 goto out;
 244         bitmap_clear(zdev->iommu_bitmap, offset, size);
 245         if (offset >= zdev->next_bit)
 246                 zdev->next_bit = offset + size;
 247 out:
 248         spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
 249 }
 250
 251 int dma_set_mask(struct device *dev, u64 mask)
 252 {
 253         if (!dev->dma_mask || !dma_supported(dev, mask))
 254                 return -EIO;
 255
 256         *dev->dma_mask = mask;
 257         return 0;
 258 }
 259 EXPORT_SYMBOL_GPL(dma_set_mask);
 260
 261 static dma_addr_t s390_dma_map_pages(struct device *dev, struct page *page,
 262                                      unsigned long offset, size_t size,
 263                                      enum dma_data_direction direction,
 264                                      struct dma_attrs *attrs)
 265 {
 266         struct zpci_dev *zdev = get_zdev(container_of(dev, struct pci_dev, dev));
 267         unsigned long nr_pages, iommu_page_index;
 268         unsigned long pa = page_to_phys(page) + offset;
 269         int flags = ZPCI_PTE_VALID;
 270         dma_addr_t dma_addr;
 271
 272         /* This rounds up number of pages based on size and offset */
 273         nr_pages = iommu_num_pages(pa, size, PAGE_SIZE);
 274         iommu_page_index = dma_alloc_iommu(zdev, nr_pages);
 275         if (iommu_page_index == -1)
 276                 goto out_err;
 277
 278         /* Use rounded up size */
 279         size = nr_pages * PAGE_SIZE;
 280
 281         dma_addr = zdev->start_dma + iommu_page_index * PAGE_SIZE;
 282         if (dma_addr + size > zdev->end_dma) {
 283                 dev_err(dev, "(dma_addr: 0x%16.16LX + size: 0x%16.16lx) > end_dma: 0x%16.16Lx\n",
 284                          dma_addr, size, zdev->end_dma);
 285                 goto out_free;
 286         }
 287
 288         if (direction == DMA_NONE || direction == DMA_TO_DEVICE)
 289                 flags |= ZPCI_TABLE_PROTECTED;
 290
 291         if (!dma_update_trans(zdev, pa, dma_addr, size, flags)) {
 292                 atomic64_add(nr_pages, (atomic64_t *) &zdev->fmb->mapped_pages);
 293                 return dma_addr + (offset & ~PAGE_MASK);
 294         }
 295
 296 out_free:
 297         dma_free_iommu(zdev, iommu_page_index, nr_pages);
 298 out_err:
 299         dev_err(dev, "Failed to map addr: %lx\n", pa);
 300         return DMA_ERROR_CODE;
 301 }
 302
 303 static void s390_dma_unmap_pages(struct device *dev, dma_addr_t dma_addr,
 304                                  size_t size, enum dma_data_direction direction,
 305                                  struct dma_attrs *attrs)
 306 {
 307         struct zpci_dev *zdev = get_zdev(container_of(dev, struct pci_dev, dev));
 308         unsigned long iommu_page_index;
 309         int npages;
 310
 311         npages = iommu_num_pages(dma_addr, size, PAGE_SIZE);
 312         dma_addr = dma_addr & PAGE_MASK;
 313         if (dma_update_trans(zdev, 0, dma_addr, npages * PAGE_SIZE,
 314                              ZPCI_TABLE_PROTECTED | ZPCI_PTE_INVALID))
 315                 dev_err(dev, "Failed to unmap addr: %Lx\n", dma_addr);
 316
 317         atomic64_add(npages, (atomic64_t *) &zdev->fmb->unmapped_pages);
 318         iommu_page_index = (dma_addr - zdev->start_dma) >> PAGE_SHIFT;
 319         dma_free_iommu(zdev, iommu_page_index, npages);
 320 }
 321
 322 static void *s390_dma_alloc(struct device *dev, size_t size,
 323                             dma_addr_t *dma_handle, gfp_t flag,
 324                             struct dma_attrs *attrs)
 325 {
 326         struct zpci_dev *zdev = get_zdev(container_of(dev, struct pci_dev, dev));
 327         struct page *page;
 328         unsigned long pa;
 329         dma_addr_t map;
 330
 331         size = PAGE_ALIGN(size);
 332         page = alloc_pages(flag, get_order(size));
 333         if (!page)
 334                 return NULL;
 335
 336         atomic64_add(size / PAGE_SIZE, (atomic64_t *) &zdev->fmb->allocated_pages);
 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         if (dma_handle)
 348                 *dma_handle = map;
 349         return (void *) pa;
 350 }
 351
 352 static void s390_dma_free(struct device *dev, size_t size,
 353                           void *pa, dma_addr_t dma_handle,
 354                           struct dma_attrs *attrs)
 355 {
 356         s390_dma_unmap_pages(dev, dma_handle, PAGE_ALIGN(size),
 357                              DMA_BIDIRECTIONAL, NULL);
 358         free_pages((unsigned long) pa, get_order(size));
 359 }
 360
 361 static int s390_dma_map_sg(struct device *dev, struct scatterlist *sg,
 362                            int nr_elements, enum dma_data_direction dir,
 363                            struct dma_attrs *attrs)
 364 {
 365         int mapped_elements = 0;
 366         struct scatterlist *s;
 367         int i;
 368
 369         for_each_sg(sg, s, nr_elements, i) {
 370                 struct page *page = sg_page(s);
 371                 s->dma_address = s390_dma_map_pages(dev, page, s->offset,
 372                                                     s->length, dir, NULL);
 373                 if (!dma_mapping_error(dev, s->dma_address)) {
 374                         s->dma_length = s->length;
 375                         mapped_elements++;
 376                 } else
 377                         goto unmap;
 378         }
 379 out:
 380         return mapped_elements;
 381
 382 unmap:
 383         for_each_sg(sg, s, mapped_elements, i) {
 384                 if (s->dma_address)
 385                         s390_dma_unmap_pages(dev, s->dma_address, s->dma_length,
 386                                              dir, NULL);
 387                 s->dma_address = 0;
 388                 s->dma_length = 0;
 389         }
 390         mapped_elements = 0;
 391         goto out;
 392 }
 393
 394 static void s390_dma_unmap_sg(struct device *dev, struct scatterlist *sg,
 395                               int nr_elements, enum dma_data_direction dir,
 396                               struct dma_attrs *attrs)
 397 {
 398         struct scatterlist *s;
 399         int i;
 400
 401         for_each_sg(sg, s, nr_elements, i) {
 402                 s390_dma_unmap_pages(dev, s->dma_address, s->dma_length, dir, NULL);
 403                 s->dma_address = 0;
 404                 s->dma_length = 0;
 405         }
 406 }
 407
 408 int zpci_dma_init_device(struct zpci_dev *zdev)
 409 {
 410         unsigned int bitmap_order;
 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         bitmap_order = get_order(zdev->iommu_pages / 8);
 425         pr_info("iommu_size: 0x%lx  iommu_pages: 0x%lx  bitmap_order: %i\n",
 426                  zdev->iommu_size, zdev->iommu_pages, bitmap_order);
 427
 428         zdev->iommu_bitmap = (void *) __get_free_pages(GFP_KERNEL | __GFP_ZERO,
 429                                                        bitmap_order);
 430         if (!zdev->iommu_bitmap) {
 431                 rc = -ENOMEM;
 432                 goto out_reg;
 433         }
 434
 435         rc = zpci_register_ioat(zdev,
 436                                 0,
 437                                 zdev->start_dma + PAGE_OFFSET,
 438                                 zdev->start_dma + zdev->iommu_size - 1,
 439                                 (u64) zdev->dma_table);
 440         if (rc)
 441                 goto out_reg;
 442         return 0;
 443
 444 out_reg:
 445         dma_free_cpu_table(zdev->dma_table);
 446 out_clean:
 447         return rc;
 448 }
 449
 450 void zpci_dma_exit_device(struct zpci_dev *zdev)
 451 {
 452         zpci_unregister_ioat(zdev, 0);
 453         dma_cleanup_tables(zdev);
 454         free_pages((unsigned long) zdev->iommu_bitmap,
 455                    get_order(zdev->iommu_pages / 8));
 456         zdev->iommu_bitmap = NULL;
 457         zdev->next_bit = 0;
 458 }
 459
 460 static int __init dma_alloc_cpu_table_caches(void)
 461 {
 462         dma_region_table_cache = kmem_cache_create("PCI_DMA_region_tables",
 463                                         ZPCI_TABLE_SIZE, ZPCI_TABLE_ALIGN,
 464                                         0, NULL);
 465         if (!dma_region_table_cache)
 466                 return -ENOMEM;
 467
 468         dma_page_table_cache = kmem_cache_create("PCI_DMA_page_tables",
 469                                         ZPCI_PT_SIZE, ZPCI_PT_ALIGN,
 470                                         0, NULL);
 471         if (!dma_page_table_cache) {
 472                 kmem_cache_destroy(dma_region_table_cache);
 473                 return -ENOMEM;
 474         }
 475         return 0;
 476 }
 477
 478 int __init zpci_dma_init(void)
 479 {
 480         return dma_alloc_cpu_table_caches();
 481 }
 482
 483 void zpci_dma_exit(void)
 484 {
 485         kmem_cache_destroy(dma_page_table_cache);
 486         kmem_cache_destroy(dma_region_table_cache);
 487 }
 488
 489 #define PREALLOC_DMA_DEBUG_ENTRIES      (1 << 16)
 490
 491 static int __init dma_debug_do_init(void)
 492 {
 493         dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
 494         return 0;
 495 }
 496 fs_initcall(dma_debug_do_init);
 497
 498 struct dma_map_ops s390_dma_ops = {
 499         .alloc          = s390_dma_alloc,
 500         .free           = s390_dma_free,
 501         .map_sg         = s390_dma_map_sg,
 502         .unmap_sg       = s390_dma_unmap_sg,
 503         .map_page       = s390_dma_map_pages,
 504         .unmap_page     = s390_dma_unmap_pages,
 505         /* if we support direct DMA this must be conditional */
 506         .is_phys        = 0,
 507         /* dma_supported is unconditionally true without a callback */
 508 };
 509 EXPORT_SYMBOL_GPL(s390_dma_ops);