arch/sparc/kernel/iommu.c

   1 /* iommu.c: Generic sparc64 IOMMU support.
   2  *
   3  * Copyright (C) 1999, 2007, 2008 David S. Miller (davem@davemloft.net)
   4  * Copyright (C) 1999, 2000 Jakub Jelinek (jakub@redhat.com)
   5  */
   6
   7 #include <linux/kernel.h>
   8 #include <linux/module.h>
   9 #include <linux/slab.h>
  10 #include <linux/delay.h>
  11 #include <linux/device.h>
  12 #include <linux/dma-mapping.h>
  13 #include <linux/errno.h>
  14 #include <linux/iommu-helper.h>
  15 #include <linux/bitmap.h>
  16
  17 #ifdef CONFIG_PCI
  18 #include <linux/pci.h>
  19 #endif
  20
  21 #include <asm/iommu.h>
  22
  23 #include "iommu_common.h"
  24
  25 #define STC_CTXMATCH_ADDR(STC, CTX)     \
  26         ((STC)->strbuf_ctxmatch_base + ((CTX) << 3))
  27 #define STC_FLUSHFLAG_INIT(STC) \
  28         (*((STC)->strbuf_flushflag) = 0UL)
  29 #define STC_FLUSHFLAG_SET(STC) \
  30         (*((STC)->strbuf_flushflag) != 0UL)
  31
  32 #define iommu_read(__reg) \
  33 ({      u64 __ret; \
  34         __asm__ __volatile__("ldxa [%1] %2, %0" \
  35                              : "=r" (__ret) \
  36                              : "r" (__reg), "i" (ASI_PHYS_BYPASS_EC_E) \
  37                              : "memory"); \
  38         __ret; \
  39 })
  40 #define iommu_write(__reg, __val) \
  41         __asm__ __volatile__("stxa %0, [%1] %2" \
  42                              : /* no outputs */ \
  43                              : "r" (__val), "r" (__reg), \
  44                                "i" (ASI_PHYS_BYPASS_EC_E))
  45
  46 /* Must be invoked under the IOMMU lock. */
  47 static void iommu_flushall(struct iommu *iommu)
  48 {
  49         if (iommu->iommu_flushinv) {
  50                 iommu_write(iommu->iommu_flushinv, ~(u64)0);
  51         } else {
  52                 unsigned long tag;
  53                 int entry;
  54
  55                 tag = iommu->iommu_tags;
  56                 for (entry = 0; entry < 16; entry++) {
  57                         iommu_write(tag, 0);
  58                         tag += 8;
  59                 }
  60
  61                 /* Ensure completion of previous PIO writes. */
  62                 (void) iommu_read(iommu->write_complete_reg);
  63         }
  64 }
  65
  66 #define IOPTE_CONSISTENT(CTX) \
  67         (IOPTE_VALID | IOPTE_CACHE | \
  68          (((CTX) << 47) & IOPTE_CONTEXT))
  69
  70 #define IOPTE_STREAMING(CTX) \
  71         (IOPTE_CONSISTENT(CTX) | IOPTE_STBUF)
  72
  73 /* Existing mappings are never marked invalid, instead they
  74  * are pointed to a dummy page.
  75  */
  76 #define IOPTE_IS_DUMMY(iommu, iopte)    \
  77         ((iopte_val(*iopte) & IOPTE_PAGE) == (iommu)->dummy_page_pa)
  78
  79 static inline void iopte_make_dummy(struct iommu *iommu, iopte_t *iopte)
  80 {
  81         unsigned long val = iopte_val(*iopte);
  82
  83         val &= ~IOPTE_PAGE;
  84         val |= iommu->dummy_page_pa;
  85
  86         iopte_val(*iopte) = val;
  87 }
  88
  89 /* Based almost entirely upon the ppc64 iommu allocator.  If you use the 'handle'
  90  * facility it must all be done in one pass while under the iommu lock.
  91  *
  92  * On sun4u platforms, we only flush the IOMMU once every time we've passed
  93  * over the entire page table doing allocations.  Therefore we only ever advance
  94  * the hint and cannot backtrack it.
  95  */
  96 unsigned long iommu_range_alloc(struct device *dev,
  97                                 struct iommu *iommu,
  98                                 unsigned long npages,
  99                                 unsigned long *handle)
 100 {
 101         unsigned long n, end, start, limit, boundary_size;
 102         struct iommu_arena *arena = &iommu->arena;
 103         int pass = 0;
 104
 105         /* This allocator was derived from x86_64's bit string search */
 106
 107         /* Sanity check */
 108         if (unlikely(npages == 0)) {
 109                 if (printk_ratelimit())
 110                         WARN_ON(1);
 111                 return DMA_ERROR_CODE;
 112         }
 113
 114         if (handle && *handle)
 115                 start = *handle;
 116         else
 117                 start = arena->hint;
 118
 119         limit = arena->limit;
 120
 121         /* The case below can happen if we have a small segment appended
 122          * to a large, or when the previous alloc was at the very end of
 123          * the available space. If so, go back to the beginning and flush.
 124          */
 125         if (start >= limit) {
 126                 start = 0;
 127                 if (iommu->flush_all)
 128                         iommu->flush_all(iommu);
 129         }
 130
 131  again:
 132
 133         if (dev)
 134                 boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1,
 135                                       1 << IO_PAGE_SHIFT);
 136         else
 137                 boundary_size = ALIGN(1UL << 32, 1 << IO_PAGE_SHIFT);
 138
 139         n = iommu_area_alloc(arena->map, limit, start, npages,
 140                              iommu->page_table_map_base >> IO_PAGE_SHIFT,
 141                              boundary_size >> IO_PAGE_SHIFT, 0);
 142         if (n == -1) {
 143                 if (likely(pass < 1)) {
 144                         /* First failure, rescan from the beginning.  */
 145                         start = 0;
 146                         if (iommu->flush_all)
 147                                 iommu->flush_all(iommu);
 148                         pass++;
 149                         goto again;
 150                 } else {
 151                         /* Second failure, give up */
 152                         return DMA_ERROR_CODE;
 153                 }
 154         }
 155
 156         end = n + npages;
 157
 158         arena->hint = end;
 159
 160         /* Update handle for SG allocations */
 161         if (handle)
 162                 *handle = end;
 163
 164         return n;
 165 }
 166
 167 void iommu_range_free(struct iommu *iommu, dma_addr_t dma_addr, unsigned long npages)
 168 {
 169         struct iommu_arena *arena = &iommu->arena;
 170         unsigned long entry;
 171
 172         entry = (dma_addr - iommu->page_table_map_base) >> IO_PAGE_SHIFT;
 173
 174         bitmap_clear(arena->map, entry, npages);
 175 }
 176
 177 int iommu_table_init(struct iommu *iommu, int tsbsize,
 178                      u32 dma_offset, u32 dma_addr_mask,
 179                      int numa_node)
 180 {
 181         unsigned long i, order, sz, num_tsb_entries;
 182         struct page *page;
 183
 184         num_tsb_entries = tsbsize / sizeof(iopte_t);
 185
 186         /* Setup initial software IOMMU state. */
 187         spin_lock_init(&iommu->lock);
 188         iommu->ctx_lowest_free = 1;
 189         iommu->page_table_map_base = dma_offset;
 190         iommu->dma_addr_mask = dma_addr_mask;
 191
 192         /* Allocate and initialize the free area map.  */
 193         sz = num_tsb_entries / 8;
 194         sz = (sz + 7UL) & ~7UL;
 195         iommu->arena.map = kmalloc_node(sz, GFP_KERNEL, numa_node);
 196         if (!iommu->arena.map) {
 197                 printk(KERN_ERR "IOMMU: Error, kmalloc(arena.map) failed.\n");
 198                 return -ENOMEM;
 199         }
 200         memset(iommu->arena.map, 0, sz);
 201         iommu->arena.limit = num_tsb_entries;
 202
 203         if (tlb_type != hypervisor)
 204                 iommu->flush_all = iommu_flushall;
 205
 206         /* Allocate and initialize the dummy page which we
 207          * set inactive IO PTEs to point to.
 208          */
 209         page = alloc_pages_node(numa_node, GFP_KERNEL, 0);
 210         if (!page) {
 211                 printk(KERN_ERR "IOMMU: Error, gfp(dummy_page) failed.\n");
 212                 goto out_free_map;
 213         }
 214         iommu->dummy_page = (unsigned long) page_address(page);
 215         memset((void *)iommu->dummy_page, 0, PAGE_SIZE);
 216         iommu->dummy_page_pa = (unsigned long) __pa(iommu->dummy_page);
 217
 218         /* Now allocate and setup the IOMMU page table itself.  */
 219         order = get_order(tsbsize);
 220         page = alloc_pages_node(numa_node, GFP_KERNEL, order);
 221         if (!page) {
 222                 printk(KERN_ERR "IOMMU: Error, gfp(tsb) failed.\n");
 223                 goto out_free_dummy_page;
 224         }
 225         iommu->page_table = (iopte_t *)page_address(page);
 226
 227         for (i = 0; i < num_tsb_entries; i++)
 228                 iopte_make_dummy(iommu, &iommu->page_table[i]);
 229
 230         return 0;
 231
 232 out_free_dummy_page:
 233         free_page(iommu->dummy_page);
 234         iommu->dummy_page = 0UL;
 235
 236 out_free_map:
 237         kfree(iommu->arena.map);
 238         iommu->arena.map = NULL;
 239
 240         return -ENOMEM;
 241 }
 242
 243 static inline iopte_t *alloc_npages(struct device *dev, struct iommu *iommu,
 244                                     unsigned long npages)
 245 {
 246         unsigned long entry;
 247
 248         entry = iommu_range_alloc(dev, iommu, npages, NULL);
 249         if (unlikely(entry == DMA_ERROR_CODE))
 250                 return NULL;
 251
 252         return iommu->page_table + entry;
 253 }
 254
 255 static int iommu_alloc_ctx(struct iommu *iommu)
 256 {
 257         int lowest = iommu->ctx_lowest_free;
 258         int n = find_next_zero_bit(iommu->ctx_bitmap, IOMMU_NUM_CTXS, lowest);
 259
 260         if (unlikely(n == IOMMU_NUM_CTXS)) {
 261                 n = find_next_zero_bit(iommu->ctx_bitmap, lowest, 1);
 262                 if (unlikely(n == lowest)) {
 263                         printk(KERN_WARNING "IOMMU: Ran out of contexts.\n");
 264                         n = 0;
 265                 }
 266         }
 267         if (n)
 268                 __set_bit(n, iommu->ctx_bitmap);
 269
 270         return n;
 271 }
 272
 273 static inline void iommu_free_ctx(struct iommu *iommu, int ctx)
 274 {
 275         if (likely(ctx)) {
 276                 __clear_bit(ctx, iommu->ctx_bitmap);
 277                 if (ctx < iommu->ctx_lowest_free)
 278                         iommu->ctx_lowest_free = ctx;
 279         }
 280 }
 281
 282 static void *dma_4u_alloc_coherent(struct device *dev, size_t size,
 283                                    dma_addr_t *dma_addrp, gfp_t gfp)
 284 {
 285         unsigned long flags, order, first_page;
 286         struct iommu *iommu;
 287         struct page *page;
 288         int npages, nid;
 289         iopte_t *iopte;
 290         void *ret;
 291
 292         size = IO_PAGE_ALIGN(size);
 293         order = get_order(size);
 294         if (order >= 10)
 295                 return NULL;
 296
 297         nid = dev->archdata.numa_node;
 298         page = alloc_pages_node(nid, gfp, order);
 299         if (unlikely(!page))
 300                 return NULL;
 301
 302         first_page = (unsigned long) page_address(page);
 303         memset((char *)first_page, 0, PAGE_SIZE << order);
 304
 305         iommu = dev->archdata.iommu;
 306
 307         spin_lock_irqsave(&iommu->lock, flags);
 308         iopte = alloc_npages(dev, iommu, size >> IO_PAGE_SHIFT);
 309         spin_unlock_irqrestore(&iommu->lock, flags);
 310
 311         if (unlikely(iopte == NULL)) {
 312                 free_pages(first_page, order);
 313                 return NULL;
 314         }
 315
 316         *dma_addrp = (iommu->page_table_map_base +
 317                       ((iopte - iommu->page_table) << IO_PAGE_SHIFT));
 318         ret = (void *) first_page;
 319         npages = size >> IO_PAGE_SHIFT;
 320         first_page = __pa(first_page);
 321         while (npages--) {
 322                 iopte_val(*iopte) = (IOPTE_CONSISTENT(0UL) |
 323                                      IOPTE_WRITE |
 324                                      (first_page & IOPTE_PAGE));
 325                 iopte++;
 326                 first_page += IO_PAGE_SIZE;
 327         }
 328
 329         return ret;
 330 }
 331
 332 static void dma_4u_free_coherent(struct device *dev, size_t size,
 333                                  void *cpu, dma_addr_t dvma)
 334 {
 335         struct iommu *iommu;
 336         unsigned long flags, order, npages;
 337
 338         npages = IO_PAGE_ALIGN(size) >> IO_PAGE_SHIFT;
 339         iommu = dev->archdata.iommu;
 340
 341         spin_lock_irqsave(&iommu->lock, flags);
 342
 343         iommu_range_free(iommu, dvma, npages);
 344
 345         spin_unlock_irqrestore(&iommu->lock, flags);
 346
 347         order = get_order(size);
 348         if (order < 10)
 349                 free_pages((unsigned long)cpu, order);
 350 }
 351
 352 static dma_addr_t dma_4u_map_page(struct device *dev, struct page *page,
 353                                   unsigned long offset, size_t sz,
 354                                   enum dma_data_direction direction,
 355                                   struct dma_attrs *attrs)
 356 {
 357         struct iommu *iommu;
 358         struct strbuf *strbuf;
 359         iopte_t *base;
 360         unsigned long flags, npages, oaddr;
 361         unsigned long i, base_paddr, ctx;
 362         u32 bus_addr, ret;
 363         unsigned long iopte_protection;
 364
 365         iommu = dev->archdata.iommu;
 366         strbuf = dev->archdata.stc;
 367
 368         if (unlikely(direction == DMA_NONE))
 369                 goto bad_no_ctx;
 370
 371         oaddr = (unsigned long)(page_address(page) + offset);
 372         npages = IO_PAGE_ALIGN(oaddr + sz) - (oaddr & IO_PAGE_MASK);
 373         npages >>= IO_PAGE_SHIFT;
 374
 375         spin_lock_irqsave(&iommu->lock, flags);
 376         base = alloc_npages(dev, iommu, npages);
 377         ctx = 0;
 378         if (iommu->iommu_ctxflush)
 379                 ctx = iommu_alloc_ctx(iommu);
 380         spin_unlock_irqrestore(&iommu->lock, flags);
 381
 382         if (unlikely(!base))
 383                 goto bad;
 384
 385         bus_addr = (iommu->page_table_map_base +
 386                     ((base - iommu->page_table) << IO_PAGE_SHIFT));
 387         ret = bus_addr | (oaddr & ~IO_PAGE_MASK);
 388         base_paddr = __pa(oaddr & IO_PAGE_MASK);
 389         if (strbuf->strbuf_enabled)
 390                 iopte_protection = IOPTE_STREAMING(ctx);
 391         else
 392                 iopte_protection = IOPTE_CONSISTENT(ctx);
 393         if (direction != DMA_TO_DEVICE)
 394                 iopte_protection |= IOPTE_WRITE;
 395
 396         for (i = 0; i < npages; i++, base++, base_paddr += IO_PAGE_SIZE)
 397                 iopte_val(*base) = iopte_protection | base_paddr;
 398
 399         return ret;
 400
 401 bad:
 402         iommu_free_ctx(iommu, ctx);
 403 bad_no_ctx:
 404         if (printk_ratelimit())
 405                 WARN_ON(1);
 406         return DMA_ERROR_CODE;
 407 }
 408
 409 static void strbuf_flush(struct strbuf *strbuf, struct iommu *iommu,
 410                          u32 vaddr, unsigned long ctx, unsigned long npages,
 411                          enum dma_data_direction direction)
 412 {
 413         int limit;
 414
 415         if (strbuf->strbuf_ctxflush &&
 416             iommu->iommu_ctxflush) {
 417                 unsigned long matchreg, flushreg;
 418                 u64 val;
 419
 420                 flushreg = strbuf->strbuf_ctxflush;
 421                 matchreg = STC_CTXMATCH_ADDR(strbuf, ctx);
 422
 423                 iommu_write(flushreg, ctx);
 424                 val = iommu_read(matchreg);
 425                 val &= 0xffff;
 426                 if (!val)
 427                         goto do_flush_sync;
 428
 429                 while (val) {
 430                         if (val & 0x1)
 431                                 iommu_write(flushreg, ctx);
 432                         val >>= 1;
 433                 }
 434                 val = iommu_read(matchreg);
 435                 if (unlikely(val)) {
 436                         printk(KERN_WARNING "strbuf_flush: ctx flush "
 437                                "timeout matchreg[%llx] ctx[%lx]\n",
 438                                val, ctx);
 439                         goto do_page_flush;
 440                 }
 441         } else {
 442                 unsigned long i;
 443
 444         do_page_flush:
 445                 for (i = 0; i < npages; i++, vaddr += IO_PAGE_SIZE)
 446                         iommu_write(strbuf->strbuf_pflush, vaddr);
 447         }
 448
 449 do_flush_sync:
 450         /* If the device could not have possibly put dirty data into
 451          * the streaming cache, no flush-flag synchronization needs
 452          * to be performed.
 453          */
 454         if (direction == DMA_TO_DEVICE)
 455                 return;
 456
 457         STC_FLUSHFLAG_INIT(strbuf);
 458         iommu_write(strbuf->strbuf_fsync, strbuf->strbuf_flushflag_pa);
 459         (void) iommu_read(iommu->write_complete_reg);
 460
 461         limit = 100000;
 462         while (!STC_FLUSHFLAG_SET(strbuf)) {
 463                 limit--;
 464                 if (!limit)
 465                         break;
 466                 udelay(1);
 467                 rmb();
 468         }
 469         if (!limit)
 470                 printk(KERN_WARNING "strbuf_flush: flushflag timeout "
 471                        "vaddr[%08x] ctx[%lx] npages[%ld]\n",
 472                        vaddr, ctx, npages);
 473 }
 474
 475 static void dma_4u_unmap_page(struct device *dev, dma_addr_t bus_addr,
 476                               size_t sz, enum dma_data_direction direction,
 477                               struct dma_attrs *attrs)
 478 {
 479         struct iommu *iommu;
 480         struct strbuf *strbuf;
 481         iopte_t *base;
 482         unsigned long flags, npages, ctx, i;
 483
 484         if (unlikely(direction == DMA_NONE)) {
 485                 if (printk_ratelimit())
 486                         WARN_ON(1);
 487                 return;
 488         }
 489
 490         iommu = dev->archdata.iommu;
 491         strbuf = dev->archdata.stc;
 492
 493         npages = IO_PAGE_ALIGN(bus_addr + sz) - (bus_addr & IO_PAGE_MASK);
 494         npages >>= IO_PAGE_SHIFT;
 495         base = iommu->page_table +
 496                 ((bus_addr - iommu->page_table_map_base) >> IO_PAGE_SHIFT);
 497         bus_addr &= IO_PAGE_MASK;
 498
 499         spin_lock_irqsave(&iommu->lock, flags);
 500
 501         /* Record the context, if any. */
 502         ctx = 0;
 503         if (iommu->iommu_ctxflush)
 504                 ctx = (iopte_val(*base) & IOPTE_CONTEXT) >> 47UL;
 505
 506         /* Step 1: Kick data out of streaming buffers if necessary. */
 507         if (strbuf->strbuf_enabled)
 508                 strbuf_flush(strbuf, iommu, bus_addr, ctx,
 509                              npages, direction);
 510
 511         /* Step 2: Clear out TSB entries. */
 512         for (i = 0; i < npages; i++)
 513                 iopte_make_dummy(iommu, base + i);
 514
 515         iommu_range_free(iommu, bus_addr, npages);
 516
 517         iommu_free_ctx(iommu, ctx);
 518
 519         spin_unlock_irqrestore(&iommu->lock, flags);
 520 }
 521
 522 static int dma_4u_map_sg(struct device *dev, struct scatterlist *sglist,
 523                          int nelems, enum dma_data_direction direction,
 524                          struct dma_attrs *attrs)
 525 {
 526         struct scatterlist *s, *outs, *segstart;
 527         unsigned long flags, handle, prot, ctx;
 528         dma_addr_t dma_next = 0, dma_addr;
 529         unsigned int max_seg_size;
 530         unsigned long seg_boundary_size;
 531         int outcount, incount, i;
 532         struct strbuf *strbuf;
 533         struct iommu *iommu;
 534         unsigned long base_shift;
 535
 536         BUG_ON(direction == DMA_NONE);
 537
 538         iommu = dev->archdata.iommu;
 539         strbuf = dev->archdata.stc;
 540         if (nelems == 0 || !iommu)
 541                 return 0;
 542
 543         spin_lock_irqsave(&iommu->lock, flags);
 544
 545         ctx = 0;
 546         if (iommu->iommu_ctxflush)
 547                 ctx = iommu_alloc_ctx(iommu);
 548
 549         if (strbuf->strbuf_enabled)
 550                 prot = IOPTE_STREAMING(ctx);
 551         else
 552                 prot = IOPTE_CONSISTENT(ctx);
 553         if (direction != DMA_TO_DEVICE)
 554                 prot |= IOPTE_WRITE;
 555
 556         outs = s = segstart = &sglist[0];
 557         outcount = 1;
 558         incount = nelems;
 559         handle = 0;
 560
 561         /* Init first segment length for backout at failure */
 562         outs->dma_length = 0;
 563
 564         max_seg_size = dma_get_max_seg_size(dev);
 565         seg_boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1,
 566                                   IO_PAGE_SIZE) >> IO_PAGE_SHIFT;
 567         base_shift = iommu->page_table_map_base >> IO_PAGE_SHIFT;
 568         for_each_sg(sglist, s, nelems, i) {
 569                 unsigned long paddr, npages, entry, out_entry = 0, slen;
 570                 iopte_t *base;
 571
 572                 slen = s->length;
 573                 /* Sanity check */
 574                 if (slen == 0) {
 575                         dma_next = 0;
 576                         continue;
 577                 }
 578                 /* Allocate iommu entries for that segment */
 579                 paddr = (unsigned long) SG_ENT_PHYS_ADDRESS(s);
 580                 npages = iommu_num_pages(paddr, slen, IO_PAGE_SIZE);
 581                 entry = iommu_range_alloc(dev, iommu, npages, &handle);
 582
 583                 /* Handle failure */
 584                 if (unlikely(entry == DMA_ERROR_CODE)) {
 585                         if (printk_ratelimit())
 586                                 printk(KERN_INFO "iommu_alloc failed, iommu %p paddr %lx"
 587                                        " npages %lx\n", iommu, paddr, npages);
 588                         goto iommu_map_failed;
 589                 }
 590
 591                 base = iommu->page_table + entry;
 592
 593                 /* Convert entry to a dma_addr_t */
 594                 dma_addr = iommu->page_table_map_base +
 595                         (entry << IO_PAGE_SHIFT);
 596                 dma_addr |= (s->offset & ~IO_PAGE_MASK);
 597
 598                 /* Insert into HW table */
 599                 paddr &= IO_PAGE_MASK;
 600                 while (npages--) {
 601                         iopte_val(*base) = prot | paddr;
 602                         base++;
 603                         paddr += IO_PAGE_SIZE;
 604                 }
 605
 606                 /* If we are in an open segment, try merging */
 607                 if (segstart != s) {
 608                         /* We cannot merge if:
 609                          * - allocated dma_addr isn't contiguous to previous allocation
 610                          */
 611                         if ((dma_addr != dma_next) ||
 612                             (outs->dma_length + s->length > max_seg_size) ||
 613                             (is_span_boundary(out_entry, base_shift,
 614                                               seg_boundary_size, outs, s))) {
 615                                 /* Can't merge: create a new segment */
 616                                 segstart = s;
 617                                 outcount++;
 618                                 outs = sg_next(outs);
 619                         } else {
 620                                 outs->dma_length += s->length;
 621                         }
 622                 }
 623
 624                 if (segstart == s) {
 625                         /* This is a new segment, fill entries */
 626                         outs->dma_address = dma_addr;
 627                         outs->dma_length = slen;
 628                         out_entry = entry;
 629                 }
 630
 631                 /* Calculate next page pointer for contiguous check */
 632                 dma_next = dma_addr + slen;
 633         }
 634
 635         spin_unlock_irqrestore(&iommu->lock, flags);
 636
 637         if (outcount < incount) {
 638                 outs = sg_next(outs);
 639                 outs->dma_address = DMA_ERROR_CODE;
 640                 outs->dma_length = 0;
 641         }
 642
 643         return outcount;
 644
 645 iommu_map_failed:
 646         for_each_sg(sglist, s, nelems, i) {
 647                 if (s->dma_length != 0) {
 648                         unsigned long vaddr, npages, entry, j;
 649                         iopte_t *base;
 650
 651                         vaddr = s->dma_address & IO_PAGE_MASK;
 652                         npages = iommu_num_pages(s->dma_address, s->dma_length,
 653                                                  IO_PAGE_SIZE);
 654                         iommu_range_free(iommu, vaddr, npages);
 655
 656                         entry = (vaddr - iommu->page_table_map_base)
 657                                 >> IO_PAGE_SHIFT;
 658                         base = iommu->page_table + entry;
 659
 660                         for (j = 0; j < npages; j++)
 661                                 iopte_make_dummy(iommu, base + j);
 662
 663                         s->dma_address = DMA_ERROR_CODE;
 664                         s->dma_length = 0;
 665                 }
 666                 if (s == outs)
 667                         break;
 668         }
 669         spin_unlock_irqrestore(&iommu->lock, flags);
 670
 671         return 0;
 672 }
 673
 674 /* If contexts are being used, they are the same in all of the mappings
 675  * we make for a particular SG.
 676  */
 677 static unsigned long fetch_sg_ctx(struct iommu *iommu, struct scatterlist *sg)
 678 {
 679         unsigned long ctx = 0;
 680
 681         if (iommu->iommu_ctxflush) {
 682                 iopte_t *base;
 683                 u32 bus_addr;
 684
 685                 bus_addr = sg->dma_address & IO_PAGE_MASK;
 686                 base = iommu->page_table +
 687                         ((bus_addr - iommu->page_table_map_base) >> IO_PAGE_SHIFT);
 688
 689                 ctx = (iopte_val(*base) & IOPTE_CONTEXT) >> 47UL;
 690         }
 691         return ctx;
 692 }
 693
 694 static void dma_4u_unmap_sg(struct device *dev, struct scatterlist *sglist,
 695                             int nelems, enum dma_data_direction direction,
 696                             struct dma_attrs *attrs)
 697 {
 698         unsigned long flags, ctx;
 699         struct scatterlist *sg;
 700         struct strbuf *strbuf;
 701         struct iommu *iommu;
 702
 703         BUG_ON(direction == DMA_NONE);
 704
 705         iommu = dev->archdata.iommu;
 706         strbuf = dev->archdata.stc;
 707
 708         ctx = fetch_sg_ctx(iommu, sglist);
 709
 710         spin_lock_irqsave(&iommu->lock, flags);
 711
 712         sg = sglist;
 713         while (nelems--) {
 714                 dma_addr_t dma_handle = sg->dma_address;
 715                 unsigned int len = sg->dma_length;
 716                 unsigned long npages, entry;
 717                 iopte_t *base;
 718                 int i;
 719
 720                 if (!len)
 721                         break;
 722                 npages = iommu_num_pages(dma_handle, len, IO_PAGE_SIZE);
 723                 iommu_range_free(iommu, dma_handle, npages);
 724
 725                 entry = ((dma_handle - iommu->page_table_map_base)
 726                          >> IO_PAGE_SHIFT);
 727                 base = iommu->page_table + entry;
 728
 729                 dma_handle &= IO_PAGE_MASK;
 730                 if (strbuf->strbuf_enabled)
 731                         strbuf_flush(strbuf, iommu, dma_handle, ctx,
 732                                      npages, direction);
 733
 734                 for (i = 0; i < npages; i++)
 735                         iopte_make_dummy(iommu, base + i);
 736
 737                 sg = sg_next(sg);
 738         }
 739
 740         iommu_free_ctx(iommu, ctx);
 741
 742         spin_unlock_irqrestore(&iommu->lock, flags);
 743 }
 744
 745 static void dma_4u_sync_single_for_cpu(struct device *dev,
 746                                        dma_addr_t bus_addr, size_t sz,
 747                                        enum dma_data_direction direction)
 748 {
 749         struct iommu *iommu;
 750         struct strbuf *strbuf;
 751         unsigned long flags, ctx, npages;
 752
 753         iommu = dev->archdata.iommu;
 754         strbuf = dev->archdata.stc;
 755
 756         if (!strbuf->strbuf_enabled)
 757                 return;
 758
 759         spin_lock_irqsave(&iommu->lock, flags);
 760
 761         npages = IO_PAGE_ALIGN(bus_addr + sz) - (bus_addr & IO_PAGE_MASK);
 762         npages >>= IO_PAGE_SHIFT;
 763         bus_addr &= IO_PAGE_MASK;
 764
 765         /* Step 1: Record the context, if any. */
 766         ctx = 0;
 767         if (iommu->iommu_ctxflush &&
 768             strbuf->strbuf_ctxflush) {
 769                 iopte_t *iopte;
 770
 771                 iopte = iommu->page_table +
 772                         ((bus_addr - iommu->page_table_map_base)>>IO_PAGE_SHIFT);
 773                 ctx = (iopte_val(*iopte) & IOPTE_CONTEXT) >> 47UL;
 774         }
 775
 776         /* Step 2: Kick data out of streaming buffers. */
 777         strbuf_flush(strbuf, iommu, bus_addr, ctx, npages, direction);
 778
 779         spin_unlock_irqrestore(&iommu->lock, flags);
 780 }
 781
 782 static void dma_4u_sync_sg_for_cpu(struct device *dev,
 783                                    struct scatterlist *sglist, int nelems,
 784                                    enum dma_data_direction direction)
 785 {
 786         struct iommu *iommu;
 787         struct strbuf *strbuf;
 788         unsigned long flags, ctx, npages, i;
 789         struct scatterlist *sg, *sgprv;
 790         u32 bus_addr;
 791
 792         iommu = dev->archdata.iommu;
 793         strbuf = dev->archdata.stc;
 794
 795         if (!strbuf->strbuf_enabled)
 796                 return;
 797
 798         spin_lock_irqsave(&iommu->lock, flags);
 799
 800         /* Step 1: Record the context, if any. */
 801         ctx = 0;
 802         if (iommu->iommu_ctxflush &&
 803             strbuf->strbuf_ctxflush) {
 804                 iopte_t *iopte;
 805
 806                 iopte = iommu->page_table +
 807                         ((sglist[0].dma_address - iommu->page_table_map_base) >> IO_PAGE_SHIFT);
 808                 ctx = (iopte_val(*iopte) & IOPTE_CONTEXT) >> 47UL;
 809         }
 810
 811         /* Step 2: Kick data out of streaming buffers. */
 812         bus_addr = sglist[0].dma_address & IO_PAGE_MASK;
 813         sgprv = NULL;
 814         for_each_sg(sglist, sg, nelems, i) {
 815                 if (sg->dma_length == 0)
 816                         break;
 817                 sgprv = sg;
 818         }
 819
 820         npages = (IO_PAGE_ALIGN(sgprv->dma_address + sgprv->dma_length)
 821                   - bus_addr) >> IO_PAGE_SHIFT;
 822         strbuf_flush(strbuf, iommu, bus_addr, ctx, npages, direction);
 823
 824         spin_unlock_irqrestore(&iommu->lock, flags);
 825 }
 826
 827 static struct dma_map_ops sun4u_dma_ops = {
 828         .alloc_coherent         = dma_4u_alloc_coherent,
 829         .free_coherent          = dma_4u_free_coherent,
 830         .map_page               = dma_4u_map_page,
 831         .unmap_page             = dma_4u_unmap_page,
 832         .map_sg                 = dma_4u_map_sg,
 833         .unmap_sg               = dma_4u_unmap_sg,
 834         .sync_single_for_cpu    = dma_4u_sync_single_for_cpu,
 835         .sync_sg_for_cpu        = dma_4u_sync_sg_for_cpu,
 836 };
 837
 838 struct dma_map_ops *dma_ops = &sun4u_dma_ops;
 839 EXPORT_SYMBOL(dma_ops);
 840
 841 extern int pci64_dma_supported(struct pci_dev *pdev, u64 device_mask);
 842
 843 int dma_supported(struct device *dev, u64 device_mask)
 844 {
 845         struct iommu *iommu = dev->archdata.iommu;
 846         u64 dma_addr_mask = iommu->dma_addr_mask;
 847
 848         if (device_mask >= (1UL << 32UL))
 849                 return 0;
 850
 851         if ((device_mask & dma_addr_mask) == dma_addr_mask)
 852                 return 1;
 853
 854 #ifdef CONFIG_PCI
 855         if (dev->bus == &pci_bus_type)
 856                 return pci64_dma_supported(to_pci_dev(dev), device_mask);
 857 #endif
 858
 859         return 0;
 860 }
 861 EXPORT_SYMBOL(dma_supported);