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         rc = rpcit_instr((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, unsigned long start,
 210                                    int size)
 211 {
 212         unsigned long boundary_size = 0x1000000;
 213
 214         return iommu_area_alloc(zdev->iommu_bitmap, zdev->iommu_pages,
 215                                 start, size, 0, boundary_size, 0);
 216 }
 217
 218 static unsigned long dma_alloc_iommu(struct zpci_dev *zdev, int size)
 219 {
 220         unsigned long offset, flags;
 221
 222         spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags);
 223         offset = __dma_alloc_iommu(zdev, zdev->next_bit, size);
 224         if (offset == -1)
 225                 offset = __dma_alloc_iommu(zdev, 0, size);
 226
 227         if (offset != -1) {
 228                 zdev->next_bit = offset + size;
 229                 if (zdev->next_bit >= zdev->iommu_pages)
 230                         zdev->next_bit = 0;
 231         }
 232         spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
 233         return offset;
 234 }
 235
 236 static void dma_free_iommu(struct zpci_dev *zdev, unsigned long offset, int size)
 237 {
 238         unsigned long flags;
 239
 240         spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags);
 241         if (!zdev->iommu_bitmap)
 242                 goto out;
 243         bitmap_clear(zdev->iommu_bitmap, offset, size);
 244         if (offset >= zdev->next_bit)
 245                 zdev->next_bit = offset + size;
 246 out:
 247         spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
 248 }
 249
 250 int dma_set_mask(struct device *dev, u64 mask)
 251 {
 252         if (!dev->dma_mask || !dma_supported(dev, mask))
 253                 return -EIO;
 254
 255         *dev->dma_mask = mask;
 256         return 0;
 257 }
 258 EXPORT_SYMBOL_GPL(dma_set_mask);
 259
 260 static dma_addr_t s390_dma_map_pages(struct device *dev, struct page *page,
 261                                      unsigned long offset, size_t size,
 262                                      enum dma_data_direction direction,
 263                                      struct dma_attrs *attrs)
 264 {
 265         struct zpci_dev *zdev = get_zdev(container_of(dev, struct pci_dev, dev));
 266         unsigned long nr_pages, iommu_page_index;
 267         unsigned long pa = page_to_phys(page) + offset;
 268         int flags = ZPCI_PTE_VALID;
 269         dma_addr_t dma_addr;
 270
 271         WARN_ON_ONCE(offset > PAGE_SIZE);
 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;
 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(container_of(dev, struct 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(container_of(dev, struct 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         unsigned int bitmap_order;
 412         int rc;
 413
 414         spin_lock_init(&zdev->iommu_bitmap_lock);
 415         spin_lock_init(&zdev->dma_table_lock);
 416
 417         zdev->dma_table = dma_alloc_cpu_table();
 418         if (!zdev->dma_table) {
 419                 rc = -ENOMEM;
 420                 goto out_clean;
 421         }
 422
 423         zdev->iommu_size = (unsigned long) high_memory - PAGE_OFFSET;
 424         zdev->iommu_pages = zdev->iommu_size >> PAGE_SHIFT;
 425         bitmap_order = get_order(zdev->iommu_pages / 8);
 426         pr_info("iommu_size: 0x%lx  iommu_pages: 0x%lx  bitmap_order: %i\n",
 427                  zdev->iommu_size, zdev->iommu_pages, bitmap_order);
 428
 429         zdev->iommu_bitmap = (void *) __get_free_pages(GFP_KERNEL | __GFP_ZERO,
 430                                                        bitmap_order);
 431         if (!zdev->iommu_bitmap) {
 432                 rc = -ENOMEM;
 433                 goto out_reg;
 434         }
 435
 436         rc = zpci_register_ioat(zdev,
 437                                 0,
 438                                 zdev->start_dma + PAGE_OFFSET,
 439                                 zdev->start_dma + zdev->iommu_size - 1,
 440                                 (u64) zdev->dma_table);
 441         if (rc)
 442                 goto out_reg;
 443         return 0;
 444
 445 out_reg:
 446         dma_free_cpu_table(zdev->dma_table);
 447 out_clean:
 448         return rc;
 449 }
 450
 451 void zpci_dma_exit_device(struct zpci_dev *zdev)
 452 {
 453         zpci_unregister_ioat(zdev, 0);
 454         dma_cleanup_tables(zdev);
 455         free_pages((unsigned long) zdev->iommu_bitmap,
 456                    get_order(zdev->iommu_pages / 8));
 457         zdev->iommu_bitmap = NULL;
 458         zdev->next_bit = 0;
 459 }
 460
 461 static int __init dma_alloc_cpu_table_caches(void)
 462 {
 463         dma_region_table_cache = kmem_cache_create("PCI_DMA_region_tables",
 464                                         ZPCI_TABLE_SIZE, ZPCI_TABLE_ALIGN,
 465                                         0, NULL);
 466         if (!dma_region_table_cache)
 467                 return -ENOMEM;
 468
 469         dma_page_table_cache = kmem_cache_create("PCI_DMA_page_tables",
 470                                         ZPCI_PT_SIZE, ZPCI_PT_ALIGN,
 471                                         0, NULL);
 472         if (!dma_page_table_cache) {
 473                 kmem_cache_destroy(dma_region_table_cache);
 474                 return -ENOMEM;
 475         }
 476         return 0;
 477 }
 478
 479 int __init zpci_dma_init(void)
 480 {
 481         return dma_alloc_cpu_table_caches();
 482 }
 483
 484 void zpci_dma_exit(void)
 485 {
 486         kmem_cache_destroy(dma_page_table_cache);
 487         kmem_cache_destroy(dma_region_table_cache);
 488 }
 489
 490 #define PREALLOC_DMA_DEBUG_ENTRIES      (1 << 16)
 491
 492 static int __init dma_debug_do_init(void)
 493 {
 494         dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
 495         return 0;
 496 }
 497 fs_initcall(dma_debug_do_init);
 498
 499 struct dma_map_ops s390_dma_ops = {
 500         .alloc          = s390_dma_alloc,
 501         .free           = s390_dma_free,
 502         .map_sg         = s390_dma_map_sg,
 503         .unmap_sg       = s390_dma_unmap_sg,
 504         .map_page       = s390_dma_map_pages,
 505         .unmap_page     = s390_dma_unmap_pages,
 506         /* if we support direct DMA this must be conditional */
 507         .is_phys        = 0,
 508         /* dma_supported is unconditionally true without a callback */
 509 };
 510 EXPORT_SYMBOL_GPL(s390_dma_ops);