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, &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, &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 pa = page_to_phys(page); 336 memset((void *) pa, 0, size); 337 338 map = s390_dma_map_pages(dev, page, pa % PAGE_SIZE, 339 size, DMA_BIDIRECTIONAL, NULL); 340 if (dma_mapping_error(dev, map)) { 341 free_pages(pa, get_order(size)); 342 return NULL; 343 } 344 345 atomic64_add(size / PAGE_SIZE, &zdev->fmb->allocated_pages); 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 struct zpci_dev *zdev = get_zdev(to_pci_dev(dev)); 356 357 size = PAGE_ALIGN(size); 358 atomic64_sub(size / PAGE_SIZE, &zdev->fmb->allocated_pages); 359 s390_dma_unmap_pages(dev, dma_handle, size, DMA_BIDIRECTIONAL, NULL); 360 free_pages((unsigned long) pa, get_order(size)); 361 } 362 363 static int s390_dma_map_sg(struct device *dev, struct scatterlist *sg, 364 int nr_elements, enum dma_data_direction dir, 365 struct dma_attrs *attrs) 366 { 367 int mapped_elements = 0; 368 struct scatterlist *s; 369 int i; 370 371 for_each_sg(sg, s, nr_elements, i) { 372 struct page *page = sg_page(s); 373 s->dma_address = s390_dma_map_pages(dev, page, s->offset, 374 s->length, dir, NULL); 375 if (!dma_mapping_error(dev, s->dma_address)) { 376 s->dma_length = s->length; 377 mapped_elements++; 378 } else 379 goto unmap; 380 } 381 out: 382 return mapped_elements; 383 384 unmap: 385 for_each_sg(sg, s, mapped_elements, i) { 386 if (s->dma_address) 387 s390_dma_unmap_pages(dev, s->dma_address, s->dma_length, 388 dir, NULL); 389 s->dma_address = 0; 390 s->dma_length = 0; 391 } 392 mapped_elements = 0; 393 goto out; 394 } 395 396 static void s390_dma_unmap_sg(struct device *dev, struct scatterlist *sg, 397 int nr_elements, enum dma_data_direction dir, 398 struct dma_attrs *attrs) 399 { 400 struct scatterlist *s; 401 int i; 402 403 for_each_sg(sg, s, nr_elements, i) { 404 s390_dma_unmap_pages(dev, s->dma_address, s->dma_length, dir, NULL); 405 s->dma_address = 0; 406 s->dma_length = 0; 407 } 408 } 409 410 int zpci_dma_init_device(struct zpci_dev *zdev) 411 { 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 zdev->iommu_bitmap = vzalloc(zdev->iommu_pages / 8); 426 if (!zdev->iommu_bitmap) { 427 rc = -ENOMEM; 428 goto out_reg; 429 } 430 431 rc = zpci_register_ioat(zdev, 432 0, 433 zdev->start_dma + PAGE_OFFSET, 434 zdev->start_dma + zdev->iommu_size - 1, 435 (u64) zdev->dma_table); 436 if (rc) 437 goto out_reg; 438 return 0; 439 440 out_reg: 441 dma_free_cpu_table(zdev->dma_table); 442 out_clean: 443 return rc; 444 } 445 446 void zpci_dma_exit_device(struct zpci_dev *zdev) 447 { 448 zpci_unregister_ioat(zdev, 0); 449 dma_cleanup_tables(zdev); 450 vfree(zdev->iommu_bitmap); 451 zdev->iommu_bitmap = NULL; 452 zdev->next_bit = 0; 453 } 454 455 static int __init dma_alloc_cpu_table_caches(void) 456 { 457 dma_region_table_cache = kmem_cache_create("PCI_DMA_region_tables", 458 ZPCI_TABLE_SIZE, ZPCI_TABLE_ALIGN, 459 0, NULL); 460 if (!dma_region_table_cache) 461 return -ENOMEM; 462 463 dma_page_table_cache = kmem_cache_create("PCI_DMA_page_tables", 464 ZPCI_PT_SIZE, ZPCI_PT_ALIGN, 465 0, NULL); 466 if (!dma_page_table_cache) { 467 kmem_cache_destroy(dma_region_table_cache); 468 return -ENOMEM; 469 } 470 return 0; 471 } 472 473 int __init zpci_dma_init(void) 474 { 475 return dma_alloc_cpu_table_caches(); 476 } 477 478 void zpci_dma_exit(void) 479 { 480 kmem_cache_destroy(dma_page_table_cache); 481 kmem_cache_destroy(dma_region_table_cache); 482 } 483 484 #define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16) 485 486 static int __init dma_debug_do_init(void) 487 { 488 dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES); 489 return 0; 490 } 491 fs_initcall(dma_debug_do_init); 492 493 struct dma_map_ops s390_dma_ops = { 494 .alloc = s390_dma_alloc, 495 .free = s390_dma_free, 496 .map_sg = s390_dma_map_sg, 497 .unmap_sg = s390_dma_unmap_sg, 498 .map_page = s390_dma_map_pages, 499 .unmap_page = s390_dma_unmap_pages, 500 /* if we support direct DMA this must be conditional */ 501 .is_phys = 0, 502 /* dma_supported is unconditionally true without a callback */ 503 }; 504 EXPORT_SYMBOL_GPL(s390_dma_ops); 505