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, 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(to_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         /* This rounds up number of pages based on size and offset */
 272         nr_pages = iommu_num_pages(pa, size, PAGE_SIZE);
 273         iommu_page_index = dma_alloc_iommu(zdev, nr_pages);
 274         if (iommu_page_index == -1)
 275                 goto out_err;
 276
 277         /* Use rounded up size */
 278         size = nr_pages * PAGE_SIZE;
 279
 280         dma_addr = zdev->start_dma + iommu_page_index * PAGE_SIZE;
 281         if (dma_addr + size > zdev->end_dma)
 282                 goto out_free;
 283
 284         if (direction == DMA_NONE || direction == DMA_TO_DEVICE)
 285                 flags |= ZPCI_TABLE_PROTECTED;
 286
 287         if (!dma_update_trans(zdev, pa, dma_addr, size, flags)) {
 288                 atomic64_add(nr_pages, (atomic64_t *) &zdev->fmb->mapped_pages);
 289                 return dma_addr + (offset & ~PAGE_MASK);
 290         }
 291
 292 out_free:
 293         dma_free_iommu(zdev, iommu_page_index, nr_pages);
 294 out_err:
 295         zpci_err("map error:\n");
 296         zpci_err_hex(&pa, sizeof(pa));
 297         return DMA_ERROR_CODE;
 298 }
 299
 300 static void s390_dma_unmap_pages(struct device *dev, dma_addr_t dma_addr,
 301                                  size_t size, enum dma_data_direction direction,
 302                                  struct dma_attrs *attrs)
 303 {
 304         struct zpci_dev *zdev = get_zdev(to_pci_dev(dev));
 305         unsigned long iommu_page_index;
 306         int npages;
 307
 308         npages = iommu_num_pages(dma_addr, size, PAGE_SIZE);
 309         dma_addr = dma_addr & PAGE_MASK;
 310         if (dma_update_trans(zdev, 0, dma_addr, npages * PAGE_SIZE,
 311                              ZPCI_TABLE_PROTECTED | ZPCI_PTE_INVALID)) {
 312                 zpci_err("unmap error:\n");
 313                 zpci_err_hex(&dma_addr, sizeof(dma_addr));
 314         }
 315
 316         atomic64_add(npages, (atomic64_t *) &zdev->fmb->unmapped_pages);
 317         iommu_page_index = (dma_addr - zdev->start_dma) >> PAGE_SHIFT;
 318         dma_free_iommu(zdev, iommu_page_index, npages);
 319 }
 320
 321 static void *s390_dma_alloc(struct device *dev, size_t size,
 322                             dma_addr_t *dma_handle, gfp_t flag,
 323                             struct dma_attrs *attrs)
 324 {
 325         struct zpci_dev *zdev = get_zdev(to_pci_dev(dev));
 326         struct page *page;
 327         unsigned long pa;
 328         dma_addr_t map;
 329
 330         size = PAGE_ALIGN(size);
 331         page = alloc_pages(flag, get_order(size));
 332         if (!page)
 333                 return NULL;
 334
 335         atomic64_add(size / PAGE_SIZE, (atomic64_t *) &zdev->fmb->allocated_pages);
 336         pa = page_to_phys(page);
 337         memset((void *) pa, 0, size);
 338
 339         map = s390_dma_map_pages(dev, page, pa % PAGE_SIZE,
 340                                  size, DMA_BIDIRECTIONAL, NULL);
 341         if (dma_mapping_error(dev, map)) {
 342                 free_pages(pa, get_order(size));
 343                 return NULL;
 344         }
 345
 346         if (dma_handle)
 347                 *dma_handle = map;
 348         return (void *) pa;
 349 }
 350
 351 static void s390_dma_free(struct device *dev, size_t size,
 352                           void *pa, dma_addr_t dma_handle,
 353                           struct dma_attrs *attrs)
 354 {
 355         s390_dma_unmap_pages(dev, dma_handle, PAGE_ALIGN(size),
 356                              DMA_BIDIRECTIONAL, NULL);
 357         free_pages((unsigned long) pa, get_order(size));
 358 }
 359
 360 static int s390_dma_map_sg(struct device *dev, struct scatterlist *sg,
 361                            int nr_elements, enum dma_data_direction dir,
 362                            struct dma_attrs *attrs)
 363 {
 364         int mapped_elements = 0;
 365         struct scatterlist *s;
 366         int i;
 367
 368         for_each_sg(sg, s, nr_elements, i) {
 369                 struct page *page = sg_page(s);
 370                 s->dma_address = s390_dma_map_pages(dev, page, s->offset,
 371                                                     s->length, dir, NULL);
 372                 if (!dma_mapping_error(dev, s->dma_address)) {
 373                         s->dma_length = s->length;
 374                         mapped_elements++;
 375                 } else
 376                         goto unmap;
 377         }
 378 out:
 379         return mapped_elements;
 380
 381 unmap:
 382         for_each_sg(sg, s, mapped_elements, i) {
 383                 if (s->dma_address)
 384                         s390_dma_unmap_pages(dev, s->dma_address, s->dma_length,
 385                                              dir, NULL);
 386                 s->dma_address = 0;
 387                 s->dma_length = 0;
 388         }
 389         mapped_elements = 0;
 390         goto out;
 391 }
 392
 393 static void s390_dma_unmap_sg(struct device *dev, struct scatterlist *sg,
 394                               int nr_elements, enum dma_data_direction dir,
 395                               struct dma_attrs *attrs)
 396 {
 397         struct scatterlist *s;
 398         int i;
 399
 400         for_each_sg(sg, s, nr_elements, i) {
 401                 s390_dma_unmap_pages(dev, s->dma_address, s->dma_length, dir, NULL);
 402                 s->dma_address = 0;
 403                 s->dma_length = 0;
 404         }
 405 }
 406
 407 int zpci_dma_init_device(struct zpci_dev *zdev)
 408 {
 409         int rc;
 410
 411         spin_lock_init(&zdev->iommu_bitmap_lock);
 412         spin_lock_init(&zdev->dma_table_lock);
 413
 414         zdev->dma_table = dma_alloc_cpu_table();
 415         if (!zdev->dma_table) {
 416                 rc = -ENOMEM;
 417                 goto out_clean;
 418         }
 419
 420         zdev->iommu_size = (unsigned long) high_memory - PAGE_OFFSET;
 421         zdev->iommu_pages = zdev->iommu_size >> PAGE_SHIFT;
 422         zdev->iommu_bitmap = vzalloc(zdev->iommu_pages / 8);
 423         if (!zdev->iommu_bitmap) {
 424                 rc = -ENOMEM;
 425                 goto out_reg;
 426         }
 427
 428         rc = zpci_register_ioat(zdev,
 429                                 0,
 430                                 zdev->start_dma + PAGE_OFFSET,
 431                                 zdev->start_dma + zdev->iommu_size - 1,
 432                                 (u64) zdev->dma_table);
 433         if (rc)
 434                 goto out_reg;
 435         return 0;
 436
 437 out_reg:
 438         dma_free_cpu_table(zdev->dma_table);
 439 out_clean:
 440         return rc;
 441 }
 442
 443 void zpci_dma_exit_device(struct zpci_dev *zdev)
 444 {
 445         zpci_unregister_ioat(zdev, 0);
 446         dma_cleanup_tables(zdev);
 447         vfree(zdev->iommu_bitmap);
 448         zdev->iommu_bitmap = NULL;
 449         zdev->next_bit = 0;
 450 }
 451
 452 static int __init dma_alloc_cpu_table_caches(void)
 453 {
 454         dma_region_table_cache = kmem_cache_create("PCI_DMA_region_tables",
 455                                         ZPCI_TABLE_SIZE, ZPCI_TABLE_ALIGN,
 456                                         0, NULL);
 457         if (!dma_region_table_cache)
 458                 return -ENOMEM;
 459
 460         dma_page_table_cache = kmem_cache_create("PCI_DMA_page_tables",
 461                                         ZPCI_PT_SIZE, ZPCI_PT_ALIGN,
 462                                         0, NULL);
 463         if (!dma_page_table_cache) {
 464                 kmem_cache_destroy(dma_region_table_cache);
 465                 return -ENOMEM;
 466         }
 467         return 0;
 468 }
 469
 470 int __init zpci_dma_init(void)
 471 {
 472         return dma_alloc_cpu_table_caches();
 473 }
 474
 475 void zpci_dma_exit(void)
 476 {
 477         kmem_cache_destroy(dma_page_table_cache);
 478         kmem_cache_destroy(dma_region_table_cache);
 479 }
 480
 481 #define PREALLOC_DMA_DEBUG_ENTRIES      (1 << 16)
 482
 483 static int __init dma_debug_do_init(void)
 484 {
 485         dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
 486         return 0;
 487 }
 488 fs_initcall(dma_debug_do_init);
 489
 490 struct dma_map_ops s390_dma_ops = {
 491         .alloc          = s390_dma_alloc,
 492         .free           = s390_dma_free,
 493         .map_sg         = s390_dma_map_sg,
 494         .unmap_sg       = s390_dma_unmap_sg,
 495         .map_page       = s390_dma_map_pages,
 496         .unmap_page     = s390_dma_unmap_pages,
 497         /* if we support direct DMA this must be conditional */
 498         .is_phys        = 0,
 499         /* dma_supported is unconditionally true without a callback */
 500 };
 501 EXPORT_SYMBOL_GPL(s390_dma_ops);