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); 510