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 sz = IOMMU_NUM_CTXS - lowest;
 259         int n = find_next_zero_bit(iommu->ctx_bitmap, sz, lowest);
 260
 261         if (unlikely(n == sz)) {
 262                 n = find_next_zero_bit(iommu->ctx_bitmap, lowest, 1);
 263                 if (unlikely(n == lowest)) {
 264                         printk(KERN_WARNING "IOMMU: Ran out of contexts.\n");
 265                         n = 0;
 266                 }
 267         }
 268         if (n)
 269                 __set_bit(n, iommu->ctx_bitmap);
 270
 271         return n;
 272 }
 273
 274 static inline void iommu_free_ctx(struct iommu *iommu, int ctx)
 275 {
 276         if (likely(ctx)) {
 277                 __clear_bit(ctx, iommu->ctx_bitmap);
 278                 if (ctx < iommu->ctx_lowest_free)
 279                         iommu->ctx_lowest_free = ctx;
 280         }
 281 }
 282
 283 static void *dma_4u_alloc_coherent(struct device *dev, size_t size,
 284                                    dma_addr_t *dma_addrp, gfp_t gfp)
 285 {
 286         unsigned long flags, order, first_page;
 287         struct iommu *iommu;
 288         struct page *page;
 289         int npages, nid;
 290         iopte_t *iopte;
 291         void *ret;
 292
 293         size = IO_PAGE_ALIGN(size);
 294         order = get_order(size);
 295         if (order >= 10)
 296                 return NULL;
 297
 298         nid = dev->archdata.numa_node;
 299         page = alloc_pages_node(nid, gfp, order);
 300         if (unlikely(!page))
 301                 return NULL;
 302
 303         first_page = (unsigned long) page_address(page);
 304         memset((char *)first_page, 0, PAGE_SIZE << order);
 305
 306         iommu = dev->archdata.iommu;
 307
 308         spin_lock_irqsave(&iommu->lock, flags);
 309         iopte = alloc_npages(dev, iommu, size >> IO_PAGE_SHIFT);
 310         spin_unlock_irqrestore(&iommu->lock, flags);
 311
 312         if (unlikely(iopte == NULL)) {
 313                 free_pages(first_page, order);
 314                 return NULL;
 315         }
 316
 317         *dma_addrp = (iommu->page_table_map_base +
 318                       ((iopte - iommu->page_table) << IO_PAGE_SHIFT));
 319         ret = (void *) first_page;
 320         npages = size >> IO_PAGE_SHIFT;
 321         first_page = __pa(first_page);
 322         while (npages--) {
 323                 iopte_val(*iopte) = (IOPTE_CONSISTENT(0UL) |
 324                                      IOPTE_WRITE |
 325                                      (first_page & IOPTE_PAGE));
 326                 iopte++;
 327                 first_page += IO_PAGE_SIZE;
 328         }
 329
 330         return ret;
 331 }
 332
 333 static void dma_4u_free_coherent(struct device *dev, size_t size,
 334                                  void *cpu, dma_addr_t dvma)
 335 {
 336         struct iommu *iommu;
 337         iopte_t *iopte;
 338         unsigned long flags, order, npages;
 339
 340         npages = IO_PAGE_ALIGN(size) >> IO_PAGE_SHIFT;
 341         iommu = dev->archdata.iommu;
 342         iopte = iommu->page_table +
 343                 ((dvma - iommu->page_table_map_base) >> IO_PAGE_SHIFT);
 344
 345         spin_lock_irqsave(&iommu->lock, flags);
 346
 347         iommu_range_free(iommu, dvma, npages);
 348
 349         spin_unlock_irqrestore(&iommu->lock, flags);
 350
 351         order = get_order(size);
 352         if (order < 10)
 353                 free_pages((unsigned long)cpu, order);
 354 }
 355
 356 static dma_addr_t dma_4u_map_page(struct device *dev, struct page *page,
 357                                   unsigned long offset, size_t sz,
 358                                   enum dma_data_direction direction,
 359                                   struct dma_attrs *attrs)
 360 {
 361         struct iommu *iommu;
 362         struct strbuf *strbuf;
 363         iopte_t *base;
 364         unsigned long flags, npages, oaddr;
 365         unsigned long i, base_paddr, ctx;
 366         u32 bus_addr, ret;
 367         unsigned long iopte_protection;
 368
 369         iommu = dev->archdata.iommu;
 370         strbuf = dev->archdata.stc;
 371
 372         if (unlikely(direction == DMA_NONE))
 373                 goto bad_no_ctx;
 374
 375         oaddr = (unsigned long)(page_address(page) + offset);
 376         npages = IO_PAGE_ALIGN(oaddr + sz) - (oaddr & IO_PAGE_MASK);
 377         npages >>= IO_PAGE_SHIFT;
 378
 379         spin_lock_irqsave(&iommu->lock, flags);
 380         base = alloc_npages(dev, iommu, npages);
 381         ctx = 0;
 382         if (iommu->iommu_ctxflush)
 383                 ctx = iommu_alloc_ctx(iommu);
 384         spin_unlock_irqrestore(&iommu->lock, flags);
 385
 386         if (unlikely(!base))
 387                 goto bad;
 388
 389         bus_addr = (iommu->page_table_map_base +
 390                     ((base - iommu->page_table) << IO_PAGE_SHIFT));
 391         ret = bus_addr | (oaddr & ~IO_PAGE_MASK);
 392         base_paddr = __pa(oaddr & IO_PAGE_MASK);
 393         if (strbuf->strbuf_enabled)
 394                 iopte_protection = IOPTE_STREAMING(ctx);
 395         else
 396                 iopte_protection = IOPTE_CONSISTENT(ctx);
 397         if (direction != DMA_TO_DEVICE)
 398                 iopte_protection |= IOPTE_WRITE;
 399
 400         for (i = 0; i < npages; i++, base++, base_paddr += IO_PAGE_SIZE)
 401                 iopte_val(*base) = iopte_protection | base_paddr;
 402
 403         return ret;
 404
 405 bad:
 406         iommu_free_ctx(iommu, ctx);
 407 bad_no_ctx:
 408         if (printk_ratelimit())
 409                 WARN_ON(1);
 410         return DMA_ERROR_CODE;
 411 }
 412
 413 static void strbuf_flush(struct strbuf *strbuf, struct iommu *iommu,
 414                          u32 vaddr, unsigned long ctx, unsigned long npages,
 415                          enum dma_data_direction direction)
 416 {
 417         int limit;
 418
 419         if (strbuf->strbuf_ctxflush &&
 420             iommu->iommu_ctxflush) {
 421                 unsigned long matchreg, flushreg;
 422                 u64 val;
 423
 424                 flushreg = strbuf->strbuf_ctxflush;
 425                 matchreg = STC_CTXMATCH_ADDR(strbuf, ctx);
 426
 427                 iommu_write(flushreg, ctx);
 428                 val = iommu_read(matchreg);
 429                 val &= 0xffff;
 430                 if (!val)
 431                         goto do_flush_sync;
 432
 433                 while (val) {
 434                         if (val & 0x1)
 435                                 iommu_write(flushreg, ctx);
 436                         val >>= 1;
 437                 }
 438                 val = iommu_read(matchreg);
 439                 if (unlikely(val)) {
 440                         printk(KERN_WARNING "strbuf_flush: ctx flush "
 441                                "timeout matchreg[%llx] ctx[%lx]\n",
 442                                val, ctx);
 443                         goto do_page_flush;
 444                 }
 445         } else {
 446                 unsigned long i;
 447
 448         do_page_flush:
 449                 for (i = 0; i < npages; i++, vaddr += IO_PAGE_SIZE)
 450                         iommu_write(strbuf->strbuf_pflush, vaddr);
 451         }
 452
 453 do_flush_sync:
 454         /* If the device could not have possibly put dirty data into
 455          * the streaming cache, no flush-flag synchronization needs
 456          * to be performed.
 457          */
 458         if (direction == DMA_TO_DEVICE)
 459                 return;
 460
 461         STC_FLUSHFLAG_INIT(strbuf);
 462         iommu_write(strbuf->strbuf_fsync, strbuf->strbuf_flushflag_pa);
 463         (void) iommu_read(iommu->write_complete_reg);
 464
 465         limit = 100000;
 466         while (!STC_FLUSHFLAG_SET(strbuf)) {
 467                 limit--;
 468                 if (!limit)
 469                         break;
 470                 udelay(1);
 471                 rmb();
 472         }
 473         if (!limit)
 474                 printk(KERN_WARNING "strbuf_flush: flushflag timeout "
 475                        "vaddr[%08x] ctx[%lx] npages[%ld]\n",
 476                        vaddr, ctx, npages);
 477 }
 478
 479 static void dma_4u_unmap_page(struct device *dev, dma_addr_t bus_addr,
 480                               size_t sz, enum dma_data_direction direction,
 481                               struct dma_attrs *attrs)
 482 {
 483         struct iommu *iommu;
 484         struct strbuf *strbuf;
 485         iopte_t *base;
 486         unsigned long flags, npages, ctx, i;
 487
 488         if (unlikely(direction == DMA_NONE)) {
 489                 if (printk_ratelimit())
 490                         WARN_ON(1);
 491                 return;
 492         }
 493
 494         iommu = dev->archdata.iommu;
 495         strbuf = dev->archdata.stc;
 496
 497         npages = IO_PAGE_ALIGN(bus_addr + sz) - (bus_addr & IO_PAGE_MASK);
 498         npages >>= IO_PAGE_SHIFT;
 499         base = iommu->page_table +
 500                 ((bus_addr - iommu->page_table_map_base) >> IO_PAGE_SHIFT);
 501         bus_addr &= IO_PAGE_MASK;
 502
 503         spin_lock_irqsave(&iommu->lock, flags);
 504
 505         /* Record the context, if any. */
 506         ctx = 0;
 507         if (iommu->iommu_ctxflush)
 508                 ctx = (iopte_val(*base) & IOPTE_CONTEXT) >> 47UL;
 509
 510         /* Step 1: Kick data out of streaming buffers if necessary. */
 511         if (strbuf->strbuf_enabled)
 512                 strbuf_flush(strbuf, iommu, bus_addr, ctx,
 513                              npages, direction);
 514
 515         /* Step 2: Clear out TSB entries. */
 516         for (i = 0; i < npages; i++)
 517                 iopte_make_dummy(iommu, base + i);
 518
 519         iommu_range_free(iommu, bus_addr, npages);
 520
 521         iommu_free_ctx(iommu, ctx);
 522
 523         spin_unlock_irqrestore(&iommu->lock, flags);
 524 }
 525
 526 static int dma_4u_map_sg(struct device *dev, struct scatterlist *sglist,
 527                          int nelems, enum dma_data_direction direction,
 528                          struct dma_attrs *attrs)
 529 {
 530         struct scatterlist *s, *outs, *segstart;
 531         unsigned long flags, handle, prot, ctx;
 532         dma_addr_t dma_next = 0, dma_addr;
 533         unsigned int max_seg_size;
 534         unsigned long seg_boundary_size;
 535         int outcount, incount, i;
 536         struct strbuf *strbuf;
 537         struct iommu *iommu;
 538         unsigned long base_shift;
 539
 540         BUG_ON(direction == DMA_NONE);
 541
 542         iommu = dev->archdata.iommu;
 543         strbuf = dev->archdata.stc;
 544         if (nelems == 0 || !iommu)
 545                 return 0;
 546
 547         spin_lock_irqsave(&iommu->lock, flags);
 548
 549         ctx = 0;
 550         if (iommu->iommu_ctxflush)
 551                 ctx = iommu_alloc_ctx(iommu);
 552
 553         if (strbuf->strbuf_enabled)
 554                 prot = IOPTE_STREAMING(ctx);
 555         else
 556                 prot = IOPTE_CONSISTENT(ctx);
 557         if (direction != DMA_TO_DEVICE)
 558                 prot |= IOPTE_WRITE;
 559
 560         outs = s = segstart = &sglist[0];
 561         outcount = 1;
 562         incount = nelems;
 563         handle = 0;
 564
 565         /* Init first segment length for backout at failure */
 566         outs->dma_length = 0;
 567
 568         max_seg_size = dma_get_max_seg_size(dev);
 569         seg_boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1,
 570                                   IO_PAGE_SIZE) >> IO_PAGE_SHIFT;
 571         base_shift = iommu->page_table_map_base >> IO_PAGE_SHIFT;
 572         for_each_sg(sglist, s, nelems, i) {
 573                 unsigned long paddr, npages, entry, out_entry = 0, slen;
 574                 iopte_t *base;
 575
 576                 slen = s->length;
 577                 /* Sanity check */
 578                 if (slen == 0) {
 579                         dma_next = 0;
 580                         continue;
 581                 }
 582                 /* Allocate iommu entries for that segment */
 583                 paddr = (unsigned long) SG_ENT_PHYS_ADDRESS(s);
 584                 npages = iommu_num_pages(paddr, slen, IO_PAGE_SIZE);
 585                 entry = iommu_range_alloc(dev, iommu, npages, &handle);
 586
 587                 /* Handle failure */
 588                 if (unlikely(entry == DMA_ERROR_CODE)) {
 589                         if (printk_ratelimit())
 590                                 printk(KERN_INFO "iommu_alloc failed, iommu %p paddr %lx"
 591                                        " npages %lx\n", iommu, paddr, npages);
 592                         goto iommu_map_failed;
 593                 }
 594
 595                 base = iommu->page_table + entry;
 596
 597                 /* Convert entry to a dma_addr_t */
 598                 dma_addr = iommu->page_table_map_base +
 599                         (entry << IO_PAGE_SHIFT);
 600                 dma_addr |= (s->offset & ~IO_PAGE_MASK);
 601
 602                 /* Insert into HW table */
 603                 paddr &= IO_PAGE_MASK;
 604                 while (npages--) {
 605                         iopte_val(*base) = prot | paddr;
 606                         base++;
 607                         paddr += IO_PAGE_SIZE;
 608                 }
 609
 610                 /* If we are in an open segment, try merging */
 611                 if (segstart != s) {
 612                         /* We cannot merge if:
 613                          * - allocated dma_addr isn't contiguous to previous allocation
 614                          */
 615                         if ((dma_addr != dma_next) ||
 616                             (outs->dma_length + s->length > max_seg_size) ||
 617                             (is_span_boundary(out_entry, base_shift,
 618                                               seg_boundary_size, outs, s))) {
 619                                 /* Can't merge: create a new segment */
 620                                 segstart = s;
 621                                 outcount++;
 622                                 outs = sg_next(outs);
 623                         } else {
 624                                 outs->dma_length += s->length;
 625                         }
 626                 }
 627
 628                 if (segstart == s) {
 629                         /* This is a new segment, fill entries */
 630                         outs->dma_address = dma_addr;
 631                         outs->dma_length = slen;
 632                         out_entry = entry;
 633                 }
 634
 635                 /* Calculate next page pointer for contiguous check */
 636                 dma_next = dma_addr + slen;
 637         }
 638
 639         spin_unlock_irqrestore(&iommu->lock, flags);
 640
 641         if (outcount < incount) {
 642                 outs = sg_next(outs);
 643                 outs->dma_address = DMA_ERROR_CODE;
 644                 outs->dma_length = 0;
 645         }
 646
 647         return outcount;
 648
 649 iommu_map_failed:
 650         for_each_sg(sglist, s, nelems, i) {
 651                 if (s->dma_length != 0) {
 652                         unsigned long vaddr, npages, entry, j;
 653                         iopte_t *base;
 654
 655                         vaddr = s->dma_address & IO_PAGE_MASK;
 656                         npages = iommu_num_pages(s->dma_address, s->dma_length,
 657                                                  IO_PAGE_SIZE);
 658                         iommu_range_free(iommu, vaddr, npages);
 659
 660                         entry = (vaddr - iommu->page_table_map_base)
 661                                 >> IO_PAGE_SHIFT;
 662                         base = iommu->page_table + entry;
 663
 664                         for (j = 0; j < npages; j++)
 665                                 iopte_make_dummy(iommu, base + j);
 666
 667                         s->dma_address = DMA_ERROR_CODE;
 668                         s->dma_length = 0;
 669                 }
 670                 if (s == outs)
 671                         break;
 672         }
 673         spin_unlock_irqrestore(&iommu->lock, flags);
 674
 675         return 0;
 676 }
 677
 678 /* If contexts are being used, they are the same in all of the mappings
 679  * we make for a particular SG.
 680  */
 681 static unsigned long fetch_sg_ctx(struct iommu *iommu, struct scatterlist *sg)
 682 {
 683         unsigned long ctx = 0;
 684
 685         if (iommu->iommu_ctxflush) {
 686                 iopte_t *base;
 687                 u32 bus_addr;
 688
 689                 bus_addr = sg->dma_address & IO_PAGE_MASK;
 690                 base = iommu->page_table +
 691                         ((bus_addr - iommu->page_table_map_base) >> IO_PAGE_SHIFT);
 692
 693                 ctx = (iopte_val(*base) & IOPTE_CONTEXT) >> 47UL;
 694         }
 695         return ctx;
 696 }
 697
 698 static void dma_4u_unmap_sg(struct device *dev, struct scatterlist *sglist,
 699                             int nelems, enum dma_data_direction direction,
 700                             struct dma_attrs *attrs)
 701 {
 702         unsigned long flags, ctx;
 703         struct scatterlist *sg;
 704         struct strbuf *strbuf;
 705         struct iommu *iommu;
 706
 707         BUG_ON(direction == DMA_NONE);
 708
 709         iommu = dev->archdata.iommu;
 710         strbuf = dev->archdata.stc;
 711
 712         ctx = fetch_sg_ctx(iommu, sglist);
 713
 714         spin_lock_irqsave(&iommu->lock, flags);
 715
 716         sg = sglist;
 717         while (nelems--) {
 718                 dma_addr_t dma_handle = sg->dma_address;
 719                 unsigned int len = sg->dma_length;
 720                 unsigned long npages, entry;
 721                 iopte_t *base;
 722                 int i;
 723
 724                 if (!len)
 725                         break;
 726                 npages = iommu_num_pages(dma_handle, len, IO_PAGE_SIZE);
 727                 iommu_range_free(iommu, dma_handle, npages);
 728
 729                 entry = ((dma_handle - iommu->page_table_map_base)
 730                          >> IO_PAGE_SHIFT);
 731                 base = iommu->page_table + entry;
 732
 733                 dma_handle &= IO_PAGE_MASK;
 734                 if (strbuf->strbuf_enabled)
 735                         strbuf_flush(strbuf, iommu, dma_handle, ctx,
 736                                      npages, direction);
 737
 738                 for (i = 0; i < npages; i++)
 739                         iopte_make_dummy(iommu, base + i);
 740
 741                 sg = sg_next(sg);
 742         }
 743
 744         iommu_free_ctx(iommu, ctx);
 745
 746         spin_unlock_irqrestore(&iommu->lock, flags);
 747 }
 748
 749 static void dma_4u_sync_single_for_cpu(struct device *dev,
 750                                        dma_addr_t bus_addr, size_t sz,
 751                                        enum dma_data_direction direction)
 752 {
 753         struct iommu *iommu;
 754         struct strbuf *strbuf;
 755         unsigned long flags, ctx, npages;
 756
 757         iommu = dev->archdata.iommu;
 758         strbuf = dev->archdata.stc;
 759
 760         if (!strbuf->strbuf_enabled)
 761                 return;
 762
 763         spin_lock_irqsave(&iommu->lock, flags);
 764
 765         npages = IO_PAGE_ALIGN(bus_addr + sz) - (bus_addr & IO_PAGE_MASK);
 766         npages >>= IO_PAGE_SHIFT;
 767         bus_addr &= IO_PAGE_MASK;
 768
 769         /* Step 1: Record the context, if any. */
 770         ctx = 0;
 771         if (iommu->iommu_ctxflush &&
 772             strbuf->strbuf_ctxflush) {
 773                 iopte_t *iopte;
 774
 775                 iopte = iommu->page_table +
 776                         ((bus_addr - iommu->page_table_map_base)>>IO_PAGE_SHIFT);
 777                 ctx = (iopte_val(*iopte) & IOPTE_CONTEXT) >> 47UL;
 778         }
 779
 780         /* Step 2: Kick data out of streaming buffers. */
 781         strbuf_flush(strbuf, iommu, bus_addr, ctx, npages, direction);
 782
 783         spin_unlock_irqrestore(&iommu->lock, flags);
 784 }
 785
 786 static void dma_4u_sync_sg_for_cpu(struct device *dev,
 787                                    struct scatterlist *sglist, int nelems,
 788                                    enum dma_data_direction direction)
 789 {
 790         struct iommu *iommu;
 791         struct strbuf *strbuf;
 792         unsigned long flags, ctx, npages, i;
 793         struct scatterlist *sg, *sgprv;
 794         u32 bus_addr;
 795
 796         iommu = dev->archdata.iommu;
 797         strbuf = dev->archdata.stc;
 798
 799         if (!strbuf->strbuf_enabled)
 800                 return;
 801
 802         spin_lock_irqsave(&iommu->lock, flags);
 803
 804         /* Step 1: Record the context, if any. */
 805         ctx = 0;
 806         if (iommu->iommu_ctxflush &&
 807             strbuf->strbuf_ctxflush) {
 808                 iopte_t *iopte;
 809
 810                 iopte = iommu->page_table +
 811                         ((sglist[0].dma_address - iommu->page_table_map_base) >> IO_PAGE_SHIFT);
 812                 ctx = (iopte_val(*iopte) & IOPTE_CONTEXT) >> 47UL;
 813         }
 814
 815         /* Step 2: Kick data out of streaming buffers. */
 816         bus_addr = sglist[0].dma_address & IO_PAGE_MASK;
 817         sgprv = NULL;
 818         for_each_sg(sglist, sg, nelems, i) {
 819                 if (sg->dma_length == 0)
 820                         break;
 821                 sgprv = sg;
 822         }
 823
 824         npages = (IO_PAGE_ALIGN(sgprv->dma_address + sgprv->dma_length)
 825                   - bus_addr) >> IO_PAGE_SHIFT;
 826         strbuf_flush(strbuf, iommu, bus_addr, ctx, npages, direction);
 827
 828         spin_unlock_irqrestore(&iommu->lock, flags);
 829 }
 830
 831 static struct dma_map_ops sun4u_dma_ops = {
 832         .alloc_coherent         = dma_4u_alloc_coherent,
 833         .free_coherent          = dma_4u_free_coherent,
 834         .map_page               = dma_4u_map_page,
 835         .unmap_page             = dma_4u_unmap_page,
 836         .map_sg                 = dma_4u_map_sg,
 837         .unmap_sg               = dma_4u_unmap_sg,
 838         .sync_single_for_cpu    = dma_4u_sync_single_for_cpu,
 839         .sync_sg_for_cpu        = dma_4u_sync_sg_for_cpu,
 840 };
 841
 842 struct dma_map_ops *dma_ops = &sun4u_dma_ops;
 843 EXPORT_SYMBOL(dma_ops);
 844
 845 extern int pci64_dma_supported(struct pci_dev *pdev, u64 device_mask);
 846
 847 int dma_supported(struct device *dev, u64 device_mask)
 848 {
 849         struct iommu *iommu = dev->archdata.iommu;
 850         u64 dma_addr_mask = iommu->dma_addr_mask;
 851
 852         if (device_mask >= (1UL << 32UL))
 853                 return 0;
 854
 855         if ((device_mask & dma_addr_mask) == dma_addr_mask)
 856                 return 1;
 857
 858 #ifdef CONFIG_PCI
 859         if (dev->bus == &pci_bus_type)
 860                 return pci64_dma_supported(to_pci_dev(dev), device_mask);
 861 #endif
 862
 863         return 0;
 864 }
 865 EXPORT_SYMBOL(dma_supported);