release/src-rt-6.x.4708/linux/linux-2.6.36/arch/parisc/kernel/pci-dma.c

   1 /*
   2 ** PARISC 1.1 Dynamic DMA mapping support.
   3 ** This implementation is for PA-RISC platforms that do not support
   4 ** I/O TLBs (aka DMA address translation hardware).
   5 ** See Documentation/PCI/PCI-DMA-mapping.txt for interface definitions.
   6 **
   7 **      (c) Copyright 1999,2000 Hewlett-Packard Company
   8 **      (c) Copyright 2000 Grant Grundler
   9 **      (c) Copyright 2000 Philipp Rumpf <prumpf@tux.org>
  10 **      (c) Copyright 2000 John Marvin
  11 **
  12 ** "leveraged" from 2.3.47: arch/ia64/kernel/pci-dma.c.
  13 ** (I assume it's from David Mosberger-Tang but there was no Copyright)
  14 **
  15 ** AFAIK, all PA7100LC and PA7300LC platforms can use this code.
  16 **
  17 ** - ggg
  18 */
  19
  20 #include <linux/init.h>
  21 #include <linux/gfp.h>
  22 #include <linux/mm.h>
  23 #include <linux/pci.h>
  24 #include <linux/proc_fs.h>
  25 #include <linux/seq_file.h>
  26 #include <linux/string.h>
  27 #include <linux/types.h>
  28 #include <linux/scatterlist.h>
  29
  30 #include <asm/cacheflush.h>
  31 #include <asm/dma.h>    /* for DMA_CHUNK_SIZE */
  32 #include <asm/io.h>
  33 #include <asm/page.h>   /* get_order */
  34 #include <asm/pgalloc.h>
  35 #include <asm/uaccess.h>
  36 #include <asm/tlbflush.h>       /* for purge_tlb_*() macros */
  37
  38 static struct proc_dir_entry * proc_gsc_root __read_mostly = NULL;
  39 static unsigned long pcxl_used_bytes __read_mostly = 0;
  40 static unsigned long pcxl_used_pages __read_mostly = 0;
  41
  42 extern unsigned long pcxl_dma_start; /* Start of pcxl dma mapping area */
  43 static spinlock_t   pcxl_res_lock;
  44 static char    *pcxl_res_map;
  45 static int     pcxl_res_hint;
  46 static int     pcxl_res_size;
  47
  48 #ifdef DEBUG_PCXL_RESOURCE
  49 #define DBG_RES(x...)   printk(x)
  50 #else
  51 #define DBG_RES(x...)
  52 #endif
  53
  54
  55 /*
  56 ** Dump a hex representation of the resource map.
  57 */
  58
  59 #ifdef DUMP_RESMAP
  60 static
  61 void dump_resmap(void)
  62 {
  63         u_long *res_ptr = (unsigned long *)pcxl_res_map;
  64         u_long i = 0;
  65
  66         printk("res_map: ");
  67         for(; i < (pcxl_res_size / sizeof(unsigned long)); ++i, ++res_ptr)
  68                 printk("%08lx ", *res_ptr);
  69
  70         printk("\n");
  71 }
  72 #else
  73 static inline void dump_resmap(void) {;}
  74 #endif
  75
  76 static int pa11_dma_supported( struct device *dev, u64 mask)
  77 {
  78         return 1;
  79 }
  80
  81 static inline int map_pte_uncached(pte_t * pte,
  82                 unsigned long vaddr,
  83                 unsigned long size, unsigned long *paddr_ptr)
  84 {
  85         unsigned long end;
  86         unsigned long orig_vaddr = vaddr;
  87
  88         vaddr &= ~PMD_MASK;
  89         end = vaddr + size;
  90         if (end > PMD_SIZE)
  91                 end = PMD_SIZE;
  92         do {
  93                 unsigned long flags;
  94
  95                 if (!pte_none(*pte))
  96                         printk(KERN_ERR "map_pte_uncached: page already exists\n");
  97                 set_pte(pte, __mk_pte(*paddr_ptr, PAGE_KERNEL_UNC));
  98                 purge_tlb_start(flags);
  99                 pdtlb_kernel(orig_vaddr);
 100                 purge_tlb_end(flags);
 101                 vaddr += PAGE_SIZE;
 102                 orig_vaddr += PAGE_SIZE;
 103                 (*paddr_ptr) += PAGE_SIZE;
 104                 pte++;
 105         } while (vaddr < end);
 106         return 0;
 107 }
 108
 109 static inline int map_pmd_uncached(pmd_t * pmd, unsigned long vaddr,
 110                 unsigned long size, unsigned long *paddr_ptr)
 111 {
 112         unsigned long end;
 113         unsigned long orig_vaddr = vaddr;
 114
 115         vaddr &= ~PGDIR_MASK;
 116         end = vaddr + size;
 117         if (end > PGDIR_SIZE)
 118                 end = PGDIR_SIZE;
 119         do {
 120                 pte_t * pte = pte_alloc_kernel(pmd, vaddr);
 121                 if (!pte)
 122                         return -ENOMEM;
 123                 if (map_pte_uncached(pte, orig_vaddr, end - vaddr, paddr_ptr))
 124                         return -ENOMEM;
 125                 vaddr = (vaddr + PMD_SIZE) & PMD_MASK;
 126                 orig_vaddr += PMD_SIZE;
 127                 pmd++;
 128         } while (vaddr < end);
 129         return 0;
 130 }
 131
 132 static inline int map_uncached_pages(unsigned long vaddr, unsigned long size,
 133                 unsigned long paddr)
 134 {
 135         pgd_t * dir;
 136         unsigned long end = vaddr + size;
 137
 138         dir = pgd_offset_k(vaddr);
 139         do {
 140                 pmd_t *pmd;
 141
 142                 pmd = pmd_alloc(NULL, dir, vaddr);
 143                 if (!pmd)
 144                         return -ENOMEM;
 145                 if (map_pmd_uncached(pmd, vaddr, end - vaddr, &paddr))
 146                         return -ENOMEM;
 147                 vaddr = vaddr + PGDIR_SIZE;
 148                 dir++;
 149         } while (vaddr && (vaddr < end));
 150         return 0;
 151 }
 152
 153 static inline void unmap_uncached_pte(pmd_t * pmd, unsigned long vaddr,
 154                 unsigned long size)
 155 {
 156         pte_t * pte;
 157         unsigned long end;
 158         unsigned long orig_vaddr = vaddr;
 159
 160         if (pmd_none(*pmd))
 161                 return;
 162         if (pmd_bad(*pmd)) {
 163                 pmd_ERROR(*pmd);
 164                 pmd_clear(pmd);
 165                 return;
 166         }
 167         pte = pte_offset_map(pmd, vaddr);
 168         vaddr &= ~PMD_MASK;
 169         end = vaddr + size;
 170         if (end > PMD_SIZE)
 171                 end = PMD_SIZE;
 172         do {
 173                 unsigned long flags;
 174                 pte_t page = *pte;
 175
 176                 pte_clear(&init_mm, vaddr, pte);
 177                 purge_tlb_start(flags);
 178                 pdtlb_kernel(orig_vaddr);
 179                 purge_tlb_end(flags);
 180                 vaddr += PAGE_SIZE;
 181                 orig_vaddr += PAGE_SIZE;
 182                 pte++;
 183                 if (pte_none(page) || pte_present(page))
 184                         continue;
 185                 printk(KERN_CRIT "Whee.. Swapped out page in kernel page table\n");
 186         } while (vaddr < end);
 187 }
 188
 189 static inline void unmap_uncached_pmd(pgd_t * dir, unsigned long vaddr,
 190                 unsigned long size)
 191 {
 192         pmd_t * pmd;
 193         unsigned long end;
 194         unsigned long orig_vaddr = vaddr;
 195
 196         if (pgd_none(*dir))
 197                 return;
 198         if (pgd_bad(*dir)) {
 199                 pgd_ERROR(*dir);
 200                 pgd_clear(dir);
 201                 return;
 202         }
 203         pmd = pmd_offset(dir, vaddr);
 204         vaddr &= ~PGDIR_MASK;
 205         end = vaddr + size;
 206         if (end > PGDIR_SIZE)
 207                 end = PGDIR_SIZE;
 208         do {
 209                 unmap_uncached_pte(pmd, orig_vaddr, end - vaddr);
 210                 vaddr = (vaddr + PMD_SIZE) & PMD_MASK;
 211                 orig_vaddr += PMD_SIZE;
 212                 pmd++;
 213         } while (vaddr < end);
 214 }
 215
 216 static void unmap_uncached_pages(unsigned long vaddr, unsigned long size)
 217 {
 218         pgd_t * dir;
 219         unsigned long end = vaddr + size;
 220
 221         dir = pgd_offset_k(vaddr);
 222         do {
 223                 unmap_uncached_pmd(dir, vaddr, end - vaddr);
 224                 vaddr = vaddr + PGDIR_SIZE;
 225                 dir++;
 226         } while (vaddr && (vaddr < end));
 227 }
 228
 229 #define PCXL_SEARCH_LOOP(idx, mask, size)  \
 230        for(; res_ptr < res_end; ++res_ptr) \
 231        { \
 232                if(0 == ((*res_ptr) & mask)) { \
 233                        *res_ptr |= mask; \
 234                        idx = (int)((u_long)res_ptr - (u_long)pcxl_res_map); \
 235                        pcxl_res_hint = idx + (size >> 3); \
 236                        goto resource_found; \
 237                } \
 238        }
 239
 240 #define PCXL_FIND_FREE_MAPPING(idx, mask, size)  { \
 241        u##size *res_ptr = (u##size *)&(pcxl_res_map[pcxl_res_hint & ~((size >> 3) - 1)]); \
 242        u##size *res_end = (u##size *)&pcxl_res_map[pcxl_res_size]; \
 243        PCXL_SEARCH_LOOP(idx, mask, size); \
 244        res_ptr = (u##size *)&pcxl_res_map[0]; \
 245        PCXL_SEARCH_LOOP(idx, mask, size); \
 246 }
 247
 248 unsigned long
 249 pcxl_alloc_range(size_t size)
 250 {
 251         int res_idx;
 252         u_long mask, flags;
 253         unsigned int pages_needed = size >> PAGE_SHIFT;
 254
 255         mask = (u_long) -1L;
 256         mask >>= BITS_PER_LONG - pages_needed;
 257
 258         DBG_RES("pcxl_alloc_range() size: %d pages_needed %d pages_mask 0x%08lx\n",
 259                 size, pages_needed, mask);
 260
 261         spin_lock_irqsave(&pcxl_res_lock, flags);
 262
 263         if(pages_needed <= 8) {
 264                 PCXL_FIND_FREE_MAPPING(res_idx, mask, 8);
 265         } else if(pages_needed <= 16) {
 266                 PCXL_FIND_FREE_MAPPING(res_idx, mask, 16);
 267         } else if(pages_needed <= 32) {
 268                 PCXL_FIND_FREE_MAPPING(res_idx, mask, 32);
 269         } else {
 270                 panic("%s: pcxl_alloc_range() Too many pages to map.\n",
 271                       __FILE__);
 272         }
 273
 274         dump_resmap();
 275         panic("%s: pcxl_alloc_range() out of dma mapping resources\n",
 276               __FILE__);
 277
 278 resource_found:
 279
 280         DBG_RES("pcxl_alloc_range() res_idx %d mask 0x%08lx res_hint: %d\n",
 281                 res_idx, mask, pcxl_res_hint);
 282
 283         pcxl_used_pages += pages_needed;
 284         pcxl_used_bytes += ((pages_needed >> 3) ? (pages_needed >> 3) : 1);
 285
 286         spin_unlock_irqrestore(&pcxl_res_lock, flags);
 287
 288         dump_resmap();
 289
 290         /*
 291         ** return the corresponding vaddr in the pcxl dma map
 292         */
 293         return (pcxl_dma_start + (res_idx << (PAGE_SHIFT + 3)));
 294 }
 295
 296 #define PCXL_FREE_MAPPINGS(idx, m, size) \
 297                 u##size *res_ptr = (u##size *)&(pcxl_res_map[(idx) + (((size >> 3) - 1) & (~((size >> 3) - 1)))]); \
 298                 /* BUG_ON((*res_ptr & m) != m); */ \
 299                 *res_ptr &= ~m;
 300
 301 /*
 302 ** clear bits in the pcxl resource map
 303 */
 304 static void
 305 pcxl_free_range(unsigned long vaddr, size_t size)
 306 {
 307         u_long mask, flags;
 308         unsigned int res_idx = (vaddr - pcxl_dma_start) >> (PAGE_SHIFT + 3);
 309         unsigned int pages_mapped = size >> PAGE_SHIFT;
 310
 311         mask = (u_long) -1L;
 312         mask >>= BITS_PER_LONG - pages_mapped;
 313
 314         DBG_RES("pcxl_free_range() res_idx: %d size: %d pages_mapped %d mask 0x%08lx\n",
 315                 res_idx, size, pages_mapped, mask);
 316
 317         spin_lock_irqsave(&pcxl_res_lock, flags);
 318
 319         if(pages_mapped <= 8) {
 320                 PCXL_FREE_MAPPINGS(res_idx, mask, 8);
 321         } else if(pages_mapped <= 16) {
 322                 PCXL_FREE_MAPPINGS(res_idx, mask, 16);
 323         } else if(pages_mapped <= 32) {
 324                 PCXL_FREE_MAPPINGS(res_idx, mask, 32);
 325         } else {
 326                 panic("%s: pcxl_free_range() Too many pages to unmap.\n",
 327                       __FILE__);
 328         }
 329
 330         pcxl_used_pages -= (pages_mapped ? pages_mapped : 1);
 331         pcxl_used_bytes -= ((pages_mapped >> 3) ? (pages_mapped >> 3) : 1);
 332
 333         spin_unlock_irqrestore(&pcxl_res_lock, flags);
 334
 335         dump_resmap();
 336 }
 337
 338 static int proc_pcxl_dma_show(struct seq_file *m, void *v)
 339 {
 340         unsigned long total_pages = pcxl_res_size << 3;   /* 8 bits per byte */
 341
 342         seq_printf(m, "\nDMA Mapping Area size    : %d bytes (%ld pages)\n",
 343                 PCXL_DMA_MAP_SIZE, total_pages);
 344
 345         seq_printf(m, "Resource bitmap : %d bytes\n", pcxl_res_size);
 346
 347         seq_puts(m,  "            total:    free:    used:   % used:\n");
 348         seq_printf(m, "blocks  %8d %8ld %8ld %8ld%%\n", pcxl_res_size,
 349                 pcxl_res_size - pcxl_used_bytes, pcxl_used_bytes,
 350                 (pcxl_used_bytes * 100) / pcxl_res_size);
 351
 352         seq_printf(m, "pages   %8ld %8ld %8ld %8ld%%\n", total_pages,
 353                 total_pages - pcxl_used_pages, pcxl_used_pages,
 354                 (pcxl_used_pages * 100 / total_pages));
 355
 356         seq_putc(m, '\n');
 357         return 0;
 358 }
 359
 360 static int proc_pcxl_dma_open(struct inode *inode, struct file *file)
 361 {
 362         return single_open(file, proc_pcxl_dma_show, NULL);
 363 }
 364
 365 static const struct file_operations proc_pcxl_dma_ops = {
 366         .owner          = THIS_MODULE,
 367         .open           = proc_pcxl_dma_open,
 368         .read           = seq_read,
 369         .llseek         = seq_lseek,
 370         .release        = single_release,
 371 };
 372
 373 static int __init
 374 pcxl_dma_init(void)
 375 {
 376         if (pcxl_dma_start == 0)
 377                 return 0;
 378
 379         spin_lock_init(&pcxl_res_lock);
 380         pcxl_res_size = PCXL_DMA_MAP_SIZE >> (PAGE_SHIFT + 3);
 381         pcxl_res_hint = 0;
 382         pcxl_res_map = (char *)__get_free_pages(GFP_KERNEL,
 383                                             get_order(pcxl_res_size));
 384         memset(pcxl_res_map, 0, pcxl_res_size);
 385         proc_gsc_root = proc_mkdir("gsc", NULL);
 386         if (!proc_gsc_root)
 387                 printk(KERN_WARNING
 388                         "pcxl_dma_init: Unable to create gsc /proc dir entry\n");
 389         else {
 390                 struct proc_dir_entry* ent;
 391                 ent = proc_create("pcxl_dma", 0, proc_gsc_root,
 392                                   &proc_pcxl_dma_ops);
 393                 if (!ent)
 394                         printk(KERN_WARNING
 395                                 "pci-dma.c: Unable to create pcxl_dma /proc entry.\n");
 396         }
 397         return 0;
 398 }
 399
 400 __initcall(pcxl_dma_init);
 401
 402 static void * pa11_dma_alloc_consistent (struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t flag)
 403 {
 404         unsigned long vaddr;
 405         unsigned long paddr;
 406         int order;
 407
 408         order = get_order(size);
 409         size = 1 << (order + PAGE_SHIFT);
 410         vaddr = pcxl_alloc_range(size);
 411         paddr = __get_free_pages(flag, order);
 412         flush_kernel_dcache_range(paddr, size);
 413         paddr = __pa(paddr);
 414         map_uncached_pages(vaddr, size, paddr);
 415         *dma_handle = (dma_addr_t) paddr;
 416
 417         return (void *)vaddr;
 418 }
 419
 420 static void pa11_dma_free_consistent (struct device *dev, size_t size, void *vaddr, dma_addr_t dma_handle)
 421 {
 422         int order;
 423
 424         order = get_order(size);
 425         size = 1 << (order + PAGE_SHIFT);
 426         unmap_uncached_pages((unsigned long)vaddr, size);
 427         pcxl_free_range((unsigned long)vaddr, size);
 428         free_pages((unsigned long)__va(dma_handle), order);
 429 }
 430
 431 static dma_addr_t pa11_dma_map_single(struct device *dev, void *addr, size_t size, enum dma_data_direction direction)
 432 {
 433         BUG_ON(direction == DMA_NONE);
 434
 435         flush_kernel_dcache_range((unsigned long) addr, size);
 436         return virt_to_phys(addr);
 437 }
 438
 439 static void pa11_dma_unmap_single(struct device *dev, dma_addr_t dma_handle, size_t size, enum dma_data_direction direction)
 440 {
 441         BUG_ON(direction == DMA_NONE);
 442
 443         if (direction == DMA_TO_DEVICE)
 444             return;
 445
 446         /*
 447          * For PCI_DMA_FROMDEVICE this flush is not necessary for the
 448          * simple map/unmap case. However, it IS necessary if if
 449          * pci_dma_sync_single_* has been called and the buffer reused.
 450          */
 451
 452         flush_kernel_dcache_range((unsigned long) phys_to_virt(dma_handle), size);
 453         return;
 454 }
 455
 456 static int pa11_dma_map_sg(struct device *dev, struct scatterlist *sglist, int nents, enum dma_data_direction direction)
 457 {
 458         int i;
 459
 460         BUG_ON(direction == DMA_NONE);
 461
 462         for (i = 0; i < nents; i++, sglist++ ) {
 463                 unsigned long vaddr = sg_virt_addr(sglist);
 464                 sg_dma_address(sglist) = (dma_addr_t) virt_to_phys(vaddr);
 465                 sg_dma_len(sglist) = sglist->length;
 466                 flush_kernel_dcache_range(vaddr, sglist->length);
 467         }
 468         return nents;
 469 }
 470
 471 static void pa11_dma_unmap_sg(struct device *dev, struct scatterlist *sglist, int nents, enum dma_data_direction direction)
 472 {
 473         int i;
 474
 475         BUG_ON(direction == DMA_NONE);
 476
 477         if (direction == DMA_TO_DEVICE)
 478             return;
 479
 480         /* once we do combining we'll need to use phys_to_virt(sg_dma_address(sglist)) */
 481
 482         for (i = 0; i < nents; i++, sglist++ )
 483                 flush_kernel_dcache_range(sg_virt_addr(sglist), sglist->length);
 484         return;
 485 }
 486
 487 static void pa11_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle, unsigned long offset, size_t size, enum dma_data_direction direction)
 488 {
 489         BUG_ON(direction == DMA_NONE);
 490
 491         flush_kernel_dcache_range((unsigned long) phys_to_virt(dma_handle) + offset, size);
 492 }
 493
 494 static void pa11_dma_sync_single_for_device(struct device *dev, dma_addr_t dma_handle, unsigned long offset, size_t size, enum dma_data_direction direction)
 495 {
 496         BUG_ON(direction == DMA_NONE);
 497
 498         flush_kernel_dcache_range((unsigned long) phys_to_virt(dma_handle) + offset, size);
 499 }
 500
 501 static void pa11_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sglist, int nents, enum dma_data_direction direction)
 502 {
 503         int i;
 504
 505         /* once we do combining we'll need to use phys_to_virt(sg_dma_address(sglist)) */
 506
 507         for (i = 0; i < nents; i++, sglist++ )
 508                 flush_kernel_dcache_range(sg_virt_addr(sglist), sglist->length);
 509 }
 510
 511 static void pa11_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sglist, int nents, enum dma_data_direction direction)
 512 {
 513         int i;
 514
 515         /* once we do combining we'll need to use phys_to_virt(sg_dma_address(sglist)) */
 516
 517         for (i = 0; i < nents; i++, sglist++ )
 518                 flush_kernel_dcache_range(sg_virt_addr(sglist), sglist->length);
 519 }
 520
 521 struct hppa_dma_ops pcxl_dma_ops = {
 522         .dma_supported =        pa11_dma_supported,
 523         .alloc_consistent =     pa11_dma_alloc_consistent,
 524         .alloc_noncoherent =    pa11_dma_alloc_consistent,
 525         .free_consistent =      pa11_dma_free_consistent,
 526         .map_single =           pa11_dma_map_single,
 527         .unmap_single =         pa11_dma_unmap_single,
 528         .map_sg =               pa11_dma_map_sg,
 529         .unmap_sg =             pa11_dma_unmap_sg,
 530         .dma_sync_single_for_cpu = pa11_dma_sync_single_for_cpu,
 531         .dma_sync_single_for_device = pa11_dma_sync_single_for_device,
 532         .dma_sync_sg_for_cpu = pa11_dma_sync_sg_for_cpu,
 533         .dma_sync_sg_for_device = pa11_dma_sync_sg_for_device,
 534 };
 535
 536 static void *fail_alloc_consistent(struct device *dev, size_t size,
 537                                    dma_addr_t *dma_handle, gfp_t flag)
 538 {
 539         return NULL;
 540 }
 541
 542 static void *pa11_dma_alloc_noncoherent(struct device *dev, size_t size,
 543                                           dma_addr_t *dma_handle, gfp_t flag)
 544 {
 545         void *addr;
 546
 547         addr = (void *)__get_free_pages(flag, get_order(size));
 548         if (addr)
 549                 *dma_handle = (dma_addr_t)virt_to_phys(addr);
 550
 551         return addr;
 552 }
 553
 554 static void pa11_dma_free_noncoherent(struct device *dev, size_t size,
 555                                         void *vaddr, dma_addr_t iova)
 556 {
 557         free_pages((unsigned long)vaddr, get_order(size));
 558         return;
 559 }
 560
 561 struct hppa_dma_ops pcx_dma_ops = {
 562         .dma_supported =        pa11_dma_supported,
 563         .alloc_consistent =     fail_alloc_consistent,
 564         .alloc_noncoherent =    pa11_dma_alloc_noncoherent,
 565         .free_consistent =      pa11_dma_free_noncoherent,
 566         .map_single =           pa11_dma_map_single,
 567         .unmap_single =         pa11_dma_unmap_single,
 568         .map_sg =               pa11_dma_map_sg,
 569         .unmap_sg =             pa11_dma_unmap_sg,
 570         .dma_sync_single_for_cpu =      pa11_dma_sync_single_for_cpu,
 571         .dma_sync_single_for_device =   pa11_dma_sync_single_for_device,
 572         .dma_sync_sg_for_cpu =          pa11_dma_sync_sg_for_cpu,
 573         .dma_sync_sg_for_device =       pa11_dma_sync_sg_for_device,
 574 };