arch/parisc/kernel/pci-dma.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3 ** PARISC 1.1 Dynamic DMA mapping support.
   4 ** This implementation is for PA-RISC platforms that do not support
   5 ** I/O TLBs (aka DMA address translation hardware).
   6 ** See Documentation/DMA-API-HOWTO.txt for interface definitions.
   7 **
   8 **      (c) Copyright 1999,2000 Hewlett-Packard Company
   9 **      (c) Copyright 2000 Grant Grundler
  10 **      (c) Copyright 2000 Philipp Rumpf <prumpf@tux.org>
  11 **      (c) Copyright 2000 John Marvin
  12 **
  13 ** "leveraged" from 2.3.47: arch/ia64/kernel/pci-dma.c.
  14 ** (I assume it's from David Mosberger-Tang but there was no Copyright)
  15 **
  16 ** AFAIK, all PA7100LC and PA7300LC platforms can use this code.
  17 **
  18 ** - ggg
  19 */
  20
  21 #include <linux/init.h>
  22 #include <linux/gfp.h>
  23 #include <linux/mm.h>
  24 #include <linux/pci.h>
  25 #include <linux/proc_fs.h>
  26 #include <linux/seq_file.h>
  27 #include <linux/string.h>
  28 #include <linux/types.h>
  29 #include <linux/scatterlist.h>
  30 #include <linux/export.h>
  31
  32 #include <asm/cacheflush.h>
  33 #include <asm/dma.h>    /* for DMA_CHUNK_SIZE */
  34 #include <asm/io.h>
  35 #include <asm/page.h>   /* get_order */
  36 #include <asm/pgalloc.h>
  37 #include <linux/uaccess.h>
  38 #include <asm/tlbflush.h>       /* for purge_tlb_*() macros */
  39
  40 static struct proc_dir_entry * proc_gsc_root __read_mostly = NULL;
  41 static unsigned long pcxl_used_bytes __read_mostly = 0;
  42 static unsigned long pcxl_used_pages __read_mostly = 0;
  43
  44 extern unsigned long pcxl_dma_start; /* Start of pcxl dma mapping area */
  45 static DEFINE_SPINLOCK(pcxl_res_lock);
  46 static char    *pcxl_res_map;
  47 static int     pcxl_res_hint;
  48 static int     pcxl_res_size;
  49
  50 #ifdef DEBUG_PCXL_RESOURCE
  51 #define DBG_RES(x...)   printk(x)
  52 #else
  53 #define DBG_RES(x...)
  54 #endif
  55
  56
  57 /*
  58 ** Dump a hex representation of the resource map.
  59 */
  60
  61 #ifdef DUMP_RESMAP
  62 static
  63 void dump_resmap(void)
  64 {
  65         u_long *res_ptr = (unsigned long *)pcxl_res_map;
  66         u_long i = 0;
  67
  68         printk("res_map: ");
  69         for(; i < (pcxl_res_size / sizeof(unsigned long)); ++i, ++res_ptr)
  70                 printk("%08lx ", *res_ptr);
  71
  72         printk("\n");
  73 }
  74 #else
  75 static inline void dump_resmap(void) {;}
  76 #endif
  77
  78 static int pa11_dma_supported( struct device *dev, u64 mask)
  79 {
  80         return 1;
  81 }
  82
  83 static inline int map_pte_uncached(pte_t * pte,
  84                 unsigned long vaddr,
  85                 unsigned long size, unsigned long *paddr_ptr)
  86 {
  87         unsigned long end;
  88         unsigned long orig_vaddr = vaddr;
  89
  90         vaddr &= ~PMD_MASK;
  91         end = vaddr + size;
  92         if (end > PMD_SIZE)
  93                 end = PMD_SIZE;
  94         do {
  95                 unsigned long flags;
  96
  97                 if (!pte_none(*pte))
  98                         printk(KERN_ERR "map_pte_uncached: page already exists\n");
  99                 purge_tlb_start(flags);
 100                 set_pte(pte, __mk_pte(*paddr_ptr, PAGE_KERNEL_UNC));
 101                 pdtlb_kernel(orig_vaddr);
 102                 purge_tlb_end(flags);
 103                 vaddr += PAGE_SIZE;
 104                 orig_vaddr += PAGE_SIZE;
 105                 (*paddr_ptr) += PAGE_SIZE;
 106                 pte++;
 107         } while (vaddr < end);
 108         return 0;
 109 }
 110
 111 static inline int map_pmd_uncached(pmd_t * pmd, unsigned long vaddr,
 112                 unsigned long size, unsigned long *paddr_ptr)
 113 {
 114         unsigned long end;
 115         unsigned long orig_vaddr = vaddr;
 116
 117         vaddr &= ~PGDIR_MASK;
 118         end = vaddr + size;
 119         if (end > PGDIR_SIZE)
 120                 end = PGDIR_SIZE;
 121         do {
 122                 pte_t * pte = pte_alloc_kernel(pmd, vaddr);
 123                 if (!pte)
 124                         return -ENOMEM;
 125                 if (map_pte_uncached(pte, orig_vaddr, end - vaddr, paddr_ptr))
 126                         return -ENOMEM;
 127                 vaddr = (vaddr + PMD_SIZE) & PMD_MASK;
 128                 orig_vaddr += PMD_SIZE;
 129                 pmd++;
 130         } while (vaddr < end);
 131         return 0;
 132 }
 133
 134 static inline int map_uncached_pages(unsigned long vaddr, unsigned long size,
 135                 unsigned long paddr)
 136 {
 137         pgd_t * dir;
 138         unsigned long end = vaddr + size;
 139
 140         dir = pgd_offset_k(vaddr);
 141         do {
 142                 pmd_t *pmd;
 143
 144                 pmd = pmd_alloc(NULL, dir, vaddr);
 145                 if (!pmd)
 146                         return -ENOMEM;
 147                 if (map_pmd_uncached(pmd, vaddr, end - vaddr, &paddr))
 148                         return -ENOMEM;
 149                 vaddr = vaddr + PGDIR_SIZE;
 150                 dir++;
 151         } while (vaddr && (vaddr < end));
 152         return 0;
 153 }
 154
 155 static inline void unmap_uncached_pte(pmd_t * pmd, unsigned long vaddr,
 156                 unsigned long size)
 157 {
 158         pte_t * pte;
 159         unsigned long end;
 160         unsigned long orig_vaddr = vaddr;
 161
 162         if (pmd_none(*pmd))
 163                 return;
 164         if (pmd_bad(*pmd)) {
 165                 pmd_ERROR(*pmd);
 166                 pmd_clear(pmd);
 167                 return;
 168         }
 169         pte = pte_offset_map(pmd, vaddr);
 170         vaddr &= ~PMD_MASK;
 171         end = vaddr + size;
 172         if (end > PMD_SIZE)
 173                 end = PMD_SIZE;
 174         do {
 175                 unsigned long flags;
 176                 pte_t page = *pte;
 177
 178                 pte_clear(&init_mm, vaddr, pte);
 179                 purge_tlb_start(flags);
 180                 pdtlb_kernel(orig_vaddr);
 181                 purge_tlb_end(flags);
 182                 vaddr += PAGE_SIZE;
 183                 orig_vaddr += PAGE_SIZE;
 184                 pte++;
 185                 if (pte_none(page) || pte_present(page))
 186                         continue;
 187                 printk(KERN_CRIT "Whee.. Swapped out page in kernel page table\n");
 188         } while (vaddr < end);
 189 }
 190
 191 static inline void unmap_uncached_pmd(pgd_t * dir, unsigned long vaddr,
 192                 unsigned long size)
 193 {
 194         pmd_t * pmd;
 195         unsigned long end;
 196         unsigned long orig_vaddr = vaddr;
 197
 198         if (pgd_none(*dir))
 199                 return;
 200         if (pgd_bad(*dir)) {
 201                 pgd_ERROR(*dir);
 202                 pgd_clear(dir);
 203                 return;
 204         }
 205         pmd = pmd_offset(dir, vaddr);
 206         vaddr &= ~PGDIR_MASK;
 207         end = vaddr + size;
 208         if (end > PGDIR_SIZE)
 209                 end = PGDIR_SIZE;
 210         do {
 211                 unmap_uncached_pte(pmd, orig_vaddr, end - vaddr);
 212                 vaddr = (vaddr + PMD_SIZE) & PMD_MASK;
 213                 orig_vaddr += PMD_SIZE;
 214                 pmd++;
 215         } while (vaddr < end);
 216 }
 217
 218 static void unmap_uncached_pages(unsigned long vaddr, unsigned long size)
 219 {
 220         pgd_t * dir;
 221         unsigned long end = vaddr + size;
 222
 223         dir = pgd_offset_k(vaddr);
 224         do {
 225                 unmap_uncached_pmd(dir, vaddr, end - vaddr);
 226                 vaddr = vaddr + PGDIR_SIZE;
 227                 dir++;
 228         } while (vaddr && (vaddr < end));
 229 }
 230
 231 #define PCXL_SEARCH_LOOP(idx, mask, size)  \
 232        for(; res_ptr < res_end; ++res_ptr) \
 233        { \
 234                if(0 == ((*res_ptr) & mask)) { \
 235                        *res_ptr |= mask; \
 236                        idx = (int)((u_long)res_ptr - (u_long)pcxl_res_map); \
 237                        pcxl_res_hint = idx + (size >> 3); \
 238                        goto resource_found; \
 239                } \
 240        }
 241
 242 #define PCXL_FIND_FREE_MAPPING(idx, mask, size)  { \
 243        u##size *res_ptr = (u##size *)&(pcxl_res_map[pcxl_res_hint & ~((size >> 3) - 1)]); \
 244        u##size *res_end = (u##size *)&pcxl_res_map[pcxl_res_size]; \
 245        PCXL_SEARCH_LOOP(idx, mask, size); \
 246        res_ptr = (u##size *)&pcxl_res_map[0]; \
 247        PCXL_SEARCH_LOOP(idx, mask, size); \
 248 }
 249
 250 unsigned long
 251 pcxl_alloc_range(size_t size)
 252 {
 253         int res_idx;
 254         u_long mask, flags;
 255         unsigned int pages_needed = size >> PAGE_SHIFT;
 256
 257         mask = (u_long) -1L;
 258         mask >>= BITS_PER_LONG - pages_needed;
 259
 260         DBG_RES("pcxl_alloc_range() size: %d pages_needed %d pages_mask 0x%08lx\n",
 261                 size, pages_needed, mask);
 262
 263         spin_lock_irqsave(&pcxl_res_lock, flags);
 264
 265         if(pages_needed <= 8) {
 266                 PCXL_FIND_FREE_MAPPING(res_idx, mask, 8);
 267         } else if(pages_needed <= 16) {
 268                 PCXL_FIND_FREE_MAPPING(res_idx, mask, 16);
 269         } else if(pages_needed <= 32) {
 270                 PCXL_FIND_FREE_MAPPING(res_idx, mask, 32);
 271         } else {
 272                 panic("%s: pcxl_alloc_range() Too many pages to map.\n",
 273                       __FILE__);
 274         }
 275
 276         dump_resmap();
 277         panic("%s: pcxl_alloc_range() out of dma mapping resources\n",
 278               __FILE__);
 279
 280 resource_found:
 281
 282         DBG_RES("pcxl_alloc_range() res_idx %d mask 0x%08lx res_hint: %d\n",
 283                 res_idx, mask, pcxl_res_hint);
 284
 285         pcxl_used_pages += pages_needed;
 286         pcxl_used_bytes += ((pages_needed >> 3) ? (pages_needed >> 3) : 1);
 287
 288         spin_unlock_irqrestore(&pcxl_res_lock, flags);
 289
 290         dump_resmap();
 291
 292         /*
 293         ** return the corresponding vaddr in the pcxl dma map
 294         */
 295         return (pcxl_dma_start + (res_idx << (PAGE_SHIFT + 3)));
 296 }
 297
 298 #define PCXL_FREE_MAPPINGS(idx, m, size) \
 299                 u##size *res_ptr = (u##size *)&(pcxl_res_map[(idx) + (((size >> 3) - 1) & (~((size >> 3) - 1)))]); \
 300                 /* BUG_ON((*res_ptr & m) != m); */ \
 301                 *res_ptr &= ~m;
 302
 303 /*
 304 ** clear bits in the pcxl resource map
 305 */
 306 static void
 307 pcxl_free_range(unsigned long vaddr, size_t size)
 308 {
 309         u_long mask, flags;
 310         unsigned int res_idx = (vaddr - pcxl_dma_start) >> (PAGE_SHIFT + 3);
 311         unsigned int pages_mapped = size >> PAGE_SHIFT;
 312
 313         mask = (u_long) -1L;
 314         mask >>= BITS_PER_LONG - pages_mapped;
 315
 316         DBG_RES("pcxl_free_range() res_idx: %d size: %d pages_mapped %d mask 0x%08lx\n",
 317                 res_idx, size, pages_mapped, mask);
 318
 319         spin_lock_irqsave(&pcxl_res_lock, flags);
 320
 321         if(pages_mapped <= 8) {
 322                 PCXL_FREE_MAPPINGS(res_idx, mask, 8);
 323         } else if(pages_mapped <= 16) {
 324                 PCXL_FREE_MAPPINGS(res_idx, mask, 16);
 325         } else if(pages_mapped <= 32) {
 326                 PCXL_FREE_MAPPINGS(res_idx, mask, 32);
 327         } else {
 328                 panic("%s: pcxl_free_range() Too many pages to unmap.\n",
 329                       __FILE__);
 330         }
 331
 332         pcxl_used_pages -= (pages_mapped ? pages_mapped : 1);
 333         pcxl_used_bytes -= ((pages_mapped >> 3) ? (pages_mapped >> 3) : 1);
 334
 335         spin_unlock_irqrestore(&pcxl_res_lock, flags);
 336
 337         dump_resmap();
 338 }
 339
 340 static int proc_pcxl_dma_show(struct seq_file *m, void *v)
 341 {
 342 #if 0
 343         u_long i = 0;
 344         unsigned long *res_ptr = (u_long *)pcxl_res_map;
 345 #endif
 346         unsigned long total_pages = pcxl_res_size << 3;   /* 8 bits per byte */
 347
 348         seq_printf(m, "\nDMA Mapping Area size    : %d bytes (%ld pages)\n",
 349                 PCXL_DMA_MAP_SIZE, total_pages);
 350
 351         seq_printf(m, "Resource bitmap : %d bytes\n", pcxl_res_size);
 352
 353         seq_puts(m,  "            total:    free:    used:   % used:\n");
 354         seq_printf(m, "blocks  %8d %8ld %8ld %8ld%%\n", pcxl_res_size,
 355                 pcxl_res_size - pcxl_used_bytes, pcxl_used_bytes,
 356                 (pcxl_used_bytes * 100) / pcxl_res_size);
 357
 358         seq_printf(m, "pages   %8ld %8ld %8ld %8ld%%\n", total_pages,
 359                 total_pages - pcxl_used_pages, pcxl_used_pages,
 360                 (pcxl_used_pages * 100 / total_pages));
 361
 362 #if 0
 363         seq_puts(m, "\nResource bitmap:");
 364
 365         for(; i < (pcxl_res_size / sizeof(u_long)); ++i, ++res_ptr) {
 366                 if ((i & 7) == 0)
 367                     seq_puts(m,"\n   ");
 368                 seq_printf(m, "%s %08lx", buf, *res_ptr);
 369         }
 370 #endif
 371         seq_putc(m, '\n');
 372         return 0;
 373 }
 374
 375 static int proc_pcxl_dma_open(struct inode *inode, struct file *file)
 376 {
 377         return single_open(file, proc_pcxl_dma_show, NULL);
 378 }
 379
 380 static const struct file_operations proc_pcxl_dma_ops = {
 381         .owner          = THIS_MODULE,
 382         .open           = proc_pcxl_dma_open,
 383         .read           = seq_read,
 384         .llseek         = seq_lseek,
 385         .release        = single_release,
 386 };
 387
 388 static int __init
 389 pcxl_dma_init(void)
 390 {
 391         if (pcxl_dma_start == 0)
 392                 return 0;
 393
 394         pcxl_res_size = PCXL_DMA_MAP_SIZE >> (PAGE_SHIFT + 3);
 395         pcxl_res_hint = 0;
 396         pcxl_res_map = (char *)__get_free_pages(GFP_KERNEL,
 397                                             get_order(pcxl_res_size));
 398         memset(pcxl_res_map, 0, pcxl_res_size);
 399         proc_gsc_root = proc_mkdir("gsc", NULL);
 400         if (!proc_gsc_root)
 401                 printk(KERN_WARNING
 402                         "pcxl_dma_init: Unable to create gsc /proc dir entry\n");
 403         else {
 404                 struct proc_dir_entry* ent;
 405                 ent = proc_create("pcxl_dma", 0, proc_gsc_root,
 406                                   &proc_pcxl_dma_ops);
 407                 if (!ent)
 408                         printk(KERN_WARNING
 409                                 "pci-dma.c: Unable to create pcxl_dma /proc entry.\n");
 410         }
 411         return 0;
 412 }
 413
 414 __initcall(pcxl_dma_init);
 415
 416 static void *pa11_dma_alloc(struct device *dev, size_t size,
 417                 dma_addr_t *dma_handle, gfp_t flag, unsigned long attrs)
 418 {
 419         unsigned long vaddr;
 420         unsigned long paddr;
 421         int order;
 422
 423         order = get_order(size);
 424         size = 1 << (order + PAGE_SHIFT);
 425         vaddr = pcxl_alloc_range(size);
 426         paddr = __get_free_pages(flag, order);
 427         flush_kernel_dcache_range(paddr, size);
 428         paddr = __pa(paddr);
 429         map_uncached_pages(vaddr, size, paddr);
 430         *dma_handle = (dma_addr_t) paddr;
 431
 432 #if 0
 433 /* This probably isn't needed to support EISA cards.
 434 ** ISA cards will certainly only support 24-bit DMA addressing.
 435 ** Not clear if we can, want, or need to support ISA.
 436 */
 437         if (!dev || *dev->coherent_dma_mask < 0xffffffff)
 438                 gfp |= GFP_DMA;
 439 #endif
 440         return (void *)vaddr;
 441 }
 442
 443 static void pa11_dma_free(struct device *dev, size_t size, void *vaddr,
 444                 dma_addr_t dma_handle, unsigned long attrs)
 445 {
 446         int order;
 447
 448         order = get_order(size);
 449         size = 1 << (order + PAGE_SHIFT);
 450         unmap_uncached_pages((unsigned long)vaddr, size);
 451         pcxl_free_range((unsigned long)vaddr, size);
 452         free_pages((unsigned long)__va(dma_handle), order);
 453 }
 454
 455 static dma_addr_t pa11_dma_map_page(struct device *dev, struct page *page,
 456                 unsigned long offset, size_t size,
 457                 enum dma_data_direction direction, unsigned long attrs)
 458 {
 459         void *addr = page_address(page) + offset;
 460         BUG_ON(direction == DMA_NONE);
 461
 462         if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
 463                 flush_kernel_dcache_range((unsigned long) addr, size);
 464
 465         return virt_to_phys(addr);
 466 }
 467
 468 static void pa11_dma_unmap_page(struct device *dev, dma_addr_t dma_handle,
 469                 size_t size, enum dma_data_direction direction,
 470                 unsigned long attrs)
 471 {
 472         BUG_ON(direction == DMA_NONE);
 473
 474         if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
 475                 return;
 476
 477         if (direction == DMA_TO_DEVICE)
 478                 return;
 479
 480         /*
 481          * For PCI_DMA_FROMDEVICE this flush is not necessary for the
 482          * simple map/unmap case. However, it IS necessary if if
 483          * pci_dma_sync_single_* has been called and the buffer reused.
 484          */
 485
 486         flush_kernel_dcache_range((unsigned long) phys_to_virt(dma_handle), size);
 487 }
 488
 489 static int pa11_dma_map_sg(struct device *dev, struct scatterlist *sglist,
 490                 int nents, enum dma_data_direction direction,
 491                 unsigned long attrs)
 492 {
 493         int i;
 494         struct scatterlist *sg;
 495
 496         BUG_ON(direction == DMA_NONE);
 497
 498         for_each_sg(sglist, sg, nents, i) {
 499                 unsigned long vaddr = (unsigned long)sg_virt(sg);
 500
 501                 sg_dma_address(sg) = (dma_addr_t) virt_to_phys(vaddr);
 502                 sg_dma_len(sg) = sg->length;
 503
 504                 if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
 505                         continue;
 506
 507                 flush_kernel_dcache_range(vaddr, sg->length);
 508         }
 509         return nents;
 510 }
 511
 512 static void pa11_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
 513                 int nents, enum dma_data_direction direction,
 514                 unsigned long attrs)
 515 {
 516         int i;
 517         struct scatterlist *sg;
 518
 519         BUG_ON(direction == DMA_NONE);
 520
 521         if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
 522                 return;
 523
 524         if (direction == DMA_TO_DEVICE)
 525                 return;
 526
 527         /* once we do combining we'll need to use phys_to_virt(sg_dma_address(sglist)) */
 528
 529         for_each_sg(sglist, sg, nents, i)
 530                 flush_kernel_vmap_range(sg_virt(sg), sg->length);
 531 }
 532
 533 static void pa11_dma_sync_single_for_cpu(struct device *dev,
 534                 dma_addr_t dma_handle, size_t size,
 535                 enum dma_data_direction direction)
 536 {
 537         BUG_ON(direction == DMA_NONE);
 538
 539         flush_kernel_dcache_range((unsigned long) phys_to_virt(dma_handle),
 540                         size);
 541 }
 542
 543 static void pa11_dma_sync_single_for_device(struct device *dev,
 544                 dma_addr_t dma_handle, size_t size,
 545                 enum dma_data_direction direction)
 546 {
 547         BUG_ON(direction == DMA_NONE);
 548
 549         flush_kernel_dcache_range((unsigned long) phys_to_virt(dma_handle),
 550                         size);
 551 }
 552
 553 static void pa11_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sglist, int nents, enum dma_data_direction direction)
 554 {
 555         int i;
 556         struct scatterlist *sg;
 557
 558         /* once we do combining we'll need to use phys_to_virt(sg_dma_address(sglist)) */
 559
 560         for_each_sg(sglist, sg, nents, i)
 561                 flush_kernel_vmap_range(sg_virt(sg), sg->length);
 562 }
 563
 564 static void pa11_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sglist, int nents, enum dma_data_direction direction)
 565 {
 566         int i;
 567         struct scatterlist *sg;
 568
 569         /* once we do combining we'll need to use phys_to_virt(sg_dma_address(sglist)) */
 570
 571         for_each_sg(sglist, sg, nents, i)
 572                 flush_kernel_vmap_range(sg_virt(sg), sg->length);
 573 }
 574
 575 const struct dma_map_ops pcxl_dma_ops = {
 576         .dma_supported =        pa11_dma_supported,
 577         .alloc =                pa11_dma_alloc,
 578         .free =                 pa11_dma_free,
 579         .map_page =             pa11_dma_map_page,
 580         .unmap_page =           pa11_dma_unmap_page,
 581         .map_sg =               pa11_dma_map_sg,
 582         .unmap_sg =             pa11_dma_unmap_sg,
 583         .sync_single_for_cpu =  pa11_dma_sync_single_for_cpu,
 584         .sync_single_for_device = pa11_dma_sync_single_for_device,
 585         .sync_sg_for_cpu =      pa11_dma_sync_sg_for_cpu,
 586         .sync_sg_for_device =   pa11_dma_sync_sg_for_device,
 587 };
 588
 589 static void *pcx_dma_alloc(struct device *dev, size_t size,
 590                 dma_addr_t *dma_handle, gfp_t flag, unsigned long attrs)
 591 {
 592         void *addr;
 593
 594         if ((attrs & DMA_ATTR_NON_CONSISTENT) == 0)
 595                 return NULL;
 596
 597         addr = (void *)__get_free_pages(flag, get_order(size));
 598         if (addr)
 599                 *dma_handle = (dma_addr_t)virt_to_phys(addr);
 600
 601         return addr;
 602 }
 603
 604 static void pcx_dma_free(struct device *dev, size_t size, void *vaddr,
 605                 dma_addr_t iova, unsigned long attrs)
 606 {
 607         free_pages((unsigned long)vaddr, get_order(size));
 608         return;
 609 }
 610
 611 const struct dma_map_ops pcx_dma_ops = {
 612         .dma_supported =        pa11_dma_supported,
 613         .alloc =                pcx_dma_alloc,
 614         .free =                 pcx_dma_free,
 615         .map_page =             pa11_dma_map_page,
 616         .unmap_page =           pa11_dma_unmap_page,
 617         .map_sg =               pa11_dma_map_sg,
 618         .unmap_sg =             pa11_dma_unmap_sg,
 619         .sync_single_for_cpu =  pa11_dma_sync_single_for_cpu,
 620         .sync_single_for_device = pa11_dma_sync_single_for_device,
 621         .sync_sg_for_cpu =      pa11_dma_sync_sg_for_cpu,
 622         .sync_sg_for_device =   pa11_dma_sync_sg_for_device,
 623 };