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pci-dma.c
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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/DMA-API-HOWTO.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 <[email protected]>
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 #include <linux/export.h>
30 
31 #include <asm/cacheflush.h>
32 #include <asm/dma.h> /* for DMA_CHUNK_SIZE */
33 #include <asm/io.h>
34 #include <asm/page.h> /* get_order */
35 #include <asm/pgalloc.h>
36 #include <asm/uaccess.h>
37 #include <asm/tlbflush.h> /* for purge_tlb_*() macros */
38 
39 static struct proc_dir_entry * proc_gsc_root __read_mostly = NULL;
40 static unsigned long pcxl_used_bytes __read_mostly = 0;
41 static unsigned long pcxl_used_pages __read_mostly = 0;
42 
43 extern unsigned long pcxl_dma_start; /* Start of pcxl dma mapping area */
44 static spinlock_t pcxl_res_lock;
45 static char *pcxl_res_map;
46 static int pcxl_res_hint;
47 static int pcxl_res_size;
48 
49 #ifdef DEBUG_PCXL_RESOURCE
50 #define DBG_RES(x...) printk(x)
51 #else
52 #define DBG_RES(x...)
53 #endif
54 
55 
56 /*
57 ** Dump a hex representation of the resource map.
58 */
59 
60 #ifdef DUMP_RESMAP
61 static
62 void dump_resmap(void)
63 {
64  u_long *res_ptr = (unsigned long *)pcxl_res_map;
65  u_long i = 0;
66 
67  printk("res_map: ");
68  for(; i < (pcxl_res_size / sizeof(unsigned long)); ++i, ++res_ptr)
69  printk("%08lx ", *res_ptr);
70 
71  printk("\n");
72 }
73 #else
74 static inline void dump_resmap(void) {;}
75 #endif
76 
77 static int pa11_dma_supported( struct device *dev, u64 mask)
78 {
79  return 1;
80 }
81 
82 static inline int map_pte_uncached(pte_t * pte,
83  unsigned long vaddr,
84  unsigned long size, unsigned long *paddr_ptr)
85 {
86  unsigned long end;
87  unsigned long orig_vaddr = vaddr;
88 
89  vaddr &= ~PMD_MASK;
90  end = vaddr + size;
91  if (end > PMD_SIZE)
92  end = PMD_SIZE;
93  do {
94  unsigned long flags;
95 
96  if (!pte_none(*pte))
97  printk(KERN_ERR "map_pte_uncached: page already exists\n");
98  set_pte(pte, __mk_pte(*paddr_ptr, PAGE_KERNEL_UNC));
99  purge_tlb_start(flags);
100  pdtlb_kernel(orig_vaddr);
101  purge_tlb_end(flags);
102  vaddr += PAGE_SIZE;
103  orig_vaddr += PAGE_SIZE;
104  (*paddr_ptr) += PAGE_SIZE;
105  pte++;
106  } while (vaddr < end);
107  return 0;
108 }
109 
110 static inline int map_pmd_uncached(pmd_t * pmd, unsigned long vaddr,
111  unsigned long size, unsigned long *paddr_ptr)
112 {
113  unsigned long end;
114  unsigned long orig_vaddr = vaddr;
115 
116  vaddr &= ~PGDIR_MASK;
117  end = vaddr + size;
118  if (end > PGDIR_SIZE)
119  end = PGDIR_SIZE;
120  do {
121  pte_t * pte = pte_alloc_kernel(pmd, vaddr);
122  if (!pte)
123  return -ENOMEM;
124  if (map_pte_uncached(pte, orig_vaddr, end - vaddr, paddr_ptr))
125  return -ENOMEM;
126  vaddr = (vaddr + PMD_SIZE) & PMD_MASK;
127  orig_vaddr += PMD_SIZE;
128  pmd++;
129  } while (vaddr < end);
130  return 0;
131 }
132 
133 static inline int map_uncached_pages(unsigned long vaddr, unsigned long size,
134  unsigned long paddr)
135 {
136  pgd_t * dir;
137  unsigned long end = vaddr + size;
138 
139  dir = pgd_offset_k(vaddr);
140  do {
141  pmd_t *pmd;
142 
143  pmd = pmd_alloc(NULL, dir, vaddr);
144  if (!pmd)
145  return -ENOMEM;
146  if (map_pmd_uncached(pmd, vaddr, end - vaddr, &paddr))
147  return -ENOMEM;
148  vaddr = vaddr + PGDIR_SIZE;
149  dir++;
150  } while (vaddr && (vaddr < end));
151  return 0;
152 }
153 
154 static inline void unmap_uncached_pte(pmd_t * pmd, unsigned long vaddr,
155  unsigned long size)
156 {
157  pte_t * pte;
158  unsigned long end;
159  unsigned long orig_vaddr = vaddr;
160 
161  if (pmd_none(*pmd))
162  return;
163  if (pmd_bad(*pmd)) {
164  pmd_ERROR(*pmd);
165  pmd_clear(pmd);
166  return;
167  }
168  pte = pte_offset_map(pmd, vaddr);
169  vaddr &= ~PMD_MASK;
170  end = vaddr + size;
171  if (end > PMD_SIZE)
172  end = PMD_SIZE;
173  do {
174  unsigned long flags;
175  pte_t page = *pte;
176 
177  pte_clear(&init_mm, vaddr, pte);
178  purge_tlb_start(flags);
179  pdtlb_kernel(orig_vaddr);
180  purge_tlb_end(flags);
181  vaddr += PAGE_SIZE;
182  orig_vaddr += PAGE_SIZE;
183  pte++;
184  if (pte_none(page) || pte_present(page))
185  continue;
186  printk(KERN_CRIT "Whee.. Swapped out page in kernel page table\n");
187  } while (vaddr < end);
188 }
189 
190 static inline void unmap_uncached_pmd(pgd_t * dir, unsigned long vaddr,
191  unsigned long size)
192 {
193  pmd_t * pmd;
194  unsigned long end;
195  unsigned long orig_vaddr = vaddr;
196 
197  if (pgd_none(*dir))
198  return;
199  if (pgd_bad(*dir)) {
200  pgd_ERROR(*dir);
201  pgd_clear(dir);
202  return;
203  }
204  pmd = pmd_offset(dir, vaddr);
205  vaddr &= ~PGDIR_MASK;
206  end = vaddr + size;
207  if (end > PGDIR_SIZE)
208  end = PGDIR_SIZE;
209  do {
210  unmap_uncached_pte(pmd, orig_vaddr, end - vaddr);
211  vaddr = (vaddr + PMD_SIZE) & PMD_MASK;
212  orig_vaddr += PMD_SIZE;
213  pmd++;
214  } while (vaddr < end);
215 }
216 
217 static void unmap_uncached_pages(unsigned long vaddr, unsigned long size)
218 {
219  pgd_t * dir;
220  unsigned long end = vaddr + size;
221 
222  dir = pgd_offset_k(vaddr);
223  do {
224  unmap_uncached_pmd(dir, vaddr, end - vaddr);
225  vaddr = vaddr + PGDIR_SIZE;
226  dir++;
227  } while (vaddr && (vaddr < end));
228 }
229 
230 #define PCXL_SEARCH_LOOP(idx, mask, size) \
231  for(; res_ptr < res_end; ++res_ptr) \
232  { \
233  if(0 == ((*res_ptr) & mask)) { \
234  *res_ptr |= mask; \
235  idx = (int)((u_long)res_ptr - (u_long)pcxl_res_map); \
236  pcxl_res_hint = idx + (size >> 3); \
237  goto resource_found; \
238  } \
239  }
240 
241 #define PCXL_FIND_FREE_MAPPING(idx, mask, size) { \
242  u##size *res_ptr = (u##size *)&(pcxl_res_map[pcxl_res_hint & ~((size >> 3) - 1)]); \
243  u##size *res_end = (u##size *)&pcxl_res_map[pcxl_res_size]; \
244  PCXL_SEARCH_LOOP(idx, mask, size); \
245  res_ptr = (u##size *)&pcxl_res_map[0]; \
246  PCXL_SEARCH_LOOP(idx, mask, size); \
247 }
248 
249 unsigned long
250 pcxl_alloc_range(size_t size)
251 {
252  int res_idx;
253  u_long mask, flags;
254  unsigned int pages_needed = size >> PAGE_SHIFT;
255 
256  mask = (u_long) -1L;
257  mask >>= BITS_PER_LONG - pages_needed;
258 
259  DBG_RES("pcxl_alloc_range() size: %d pages_needed %d pages_mask 0x%08lx\n",
260  size, pages_needed, mask);
261 
262  spin_lock_irqsave(&pcxl_res_lock, flags);
263 
264  if(pages_needed <= 8) {
265  PCXL_FIND_FREE_MAPPING(res_idx, mask, 8);
266  } else if(pages_needed <= 16) {
267  PCXL_FIND_FREE_MAPPING(res_idx, mask, 16);
268  } else if(pages_needed <= 32) {
269  PCXL_FIND_FREE_MAPPING(res_idx, mask, 32);
270  } else {
271  panic("%s: pcxl_alloc_range() Too many pages to map.\n",
272  __FILE__);
273  }
274 
275  dump_resmap();
276  panic("%s: pcxl_alloc_range() out of dma mapping resources\n",
277  __FILE__);
278 
279 resource_found:
280 
281  DBG_RES("pcxl_alloc_range() res_idx %d mask 0x%08lx res_hint: %d\n",
282  res_idx, mask, pcxl_res_hint);
283 
284  pcxl_used_pages += pages_needed;
285  pcxl_used_bytes += ((pages_needed >> 3) ? (pages_needed >> 3) : 1);
286 
287  spin_unlock_irqrestore(&pcxl_res_lock, flags);
288 
289  dump_resmap();
290 
291  /*
292  ** return the corresponding vaddr in the pcxl dma map
293  */
294  return (pcxl_dma_start + (res_idx << (PAGE_SHIFT + 3)));
295 }
296 
297 #define PCXL_FREE_MAPPINGS(idx, m, size) \
298  u##size *res_ptr = (u##size *)&(pcxl_res_map[(idx) + (((size >> 3) - 1) & (~((size >> 3) - 1)))]); \
299  /* BUG_ON((*res_ptr & m) != m); */ \
300  *res_ptr &= ~m;
301 
302 /*
303 ** clear bits in the pcxl resource map
304 */
305 static void
306 pcxl_free_range(unsigned long vaddr, size_t size)
307 {
308  u_long mask, flags;
309  unsigned int res_idx = (vaddr - pcxl_dma_start) >> (PAGE_SHIFT + 3);
310  unsigned int pages_mapped = size >> PAGE_SHIFT;
311 
312  mask = (u_long) -1L;
313  mask >>= BITS_PER_LONG - pages_mapped;
314 
315  DBG_RES("pcxl_free_range() res_idx: %d size: %d pages_mapped %d mask 0x%08lx\n",
316  res_idx, size, pages_mapped, mask);
317 
318  spin_lock_irqsave(&pcxl_res_lock, flags);
319 
320  if(pages_mapped <= 8) {
321  PCXL_FREE_MAPPINGS(res_idx, mask, 8);
322  } else if(pages_mapped <= 16) {
323  PCXL_FREE_MAPPINGS(res_idx, mask, 16);
324  } else if(pages_mapped <= 32) {
325  PCXL_FREE_MAPPINGS(res_idx, mask, 32);
326  } else {
327  panic("%s: pcxl_free_range() Too many pages to unmap.\n",
328  __FILE__);
329  }
330 
331  pcxl_used_pages -= (pages_mapped ? pages_mapped : 1);
332  pcxl_used_bytes -= ((pages_mapped >> 3) ? (pages_mapped >> 3) : 1);
333 
334  spin_unlock_irqrestore(&pcxl_res_lock, flags);
335 
336  dump_resmap();
337 }
338 
339 static int proc_pcxl_dma_show(struct seq_file *m, void *v)
340 {
341 #if 0
342  u_long i = 0;
343  unsigned long *res_ptr = (u_long *)pcxl_res_map;
344 #endif
345  unsigned long total_pages = pcxl_res_size << 3; /* 8 bits per byte */
346 
347  seq_printf(m, "\nDMA Mapping Area size : %d bytes (%ld pages)\n",
348  PCXL_DMA_MAP_SIZE, total_pages);
349 
350  seq_printf(m, "Resource bitmap : %d bytes\n", pcxl_res_size);
351 
352  seq_puts(m, " total: free: used: % used:\n");
353  seq_printf(m, "blocks %8d %8ld %8ld %8ld%%\n", pcxl_res_size,
354  pcxl_res_size - pcxl_used_bytes, pcxl_used_bytes,
355  (pcxl_used_bytes * 100) / pcxl_res_size);
356 
357  seq_printf(m, "pages %8ld %8ld %8ld %8ld%%\n", total_pages,
358  total_pages - pcxl_used_pages, pcxl_used_pages,
359  (pcxl_used_pages * 100 / total_pages));
360 
361 #if 0
362  seq_puts(m, "\nResource bitmap:");
363 
364  for(; i < (pcxl_res_size / sizeof(u_long)); ++i, ++res_ptr) {
365  if ((i & 7) == 0)
366  seq_puts(m,"\n ");
367  seq_printf(m, "%s %08lx", buf, *res_ptr);
368  }
369 #endif
370  seq_putc(m, '\n');
371  return 0;
372 }
373 
374 static int proc_pcxl_dma_open(struct inode *inode, struct file *file)
375 {
376  return single_open(file, proc_pcxl_dma_show, NULL);
377 }
378 
379 static const struct file_operations proc_pcxl_dma_ops = {
380  .owner = THIS_MODULE,
381  .open = proc_pcxl_dma_open,
382  .read = seq_read,
383  .llseek = seq_lseek,
384  .release = single_release,
385 };
386 
387 static int __init
388 pcxl_dma_init(void)
389 {
390  if (pcxl_dma_start == 0)
391  return 0;
392 
393  spin_lock_init(&pcxl_res_lock);
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)
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)
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_consistent (struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t flag)
417 {
418  unsigned long vaddr;
419  unsigned long paddr;
420  int order;
421 
422  order = get_order(size);
423  size = 1 << (order + PAGE_SHIFT);
424  vaddr = pcxl_alloc_range(size);
425  paddr = __get_free_pages(flag, order);
426  flush_kernel_dcache_range(paddr, size);
427  paddr = __pa(paddr);
428  map_uncached_pages(vaddr, size, paddr);
429  *dma_handle = (dma_addr_t) paddr;
430 
431 #if 0
432 /* This probably isn't needed to support EISA cards.
433 ** ISA cards will certainly only support 24-bit DMA addressing.
434 ** Not clear if we can, want, or need to support ISA.
435 */
436  if (!dev || *dev->coherent_dma_mask < 0xffffffff)
437  gfp |= GFP_DMA;
438 #endif
439  return (void *)vaddr;
440 }
441 
442 static void pa11_dma_free_consistent (struct device *dev, size_t size, void *vaddr, dma_addr_t dma_handle)
443 {
444  int order;
445 
446  order = get_order(size);
447  size = 1 << (order + PAGE_SHIFT);
448  unmap_uncached_pages((unsigned long)vaddr, size);
449  pcxl_free_range((unsigned long)vaddr, size);
450  free_pages((unsigned long)__va(dma_handle), order);
451 }
452 
453 static dma_addr_t pa11_dma_map_single(struct device *dev, void *addr, size_t size, enum dma_data_direction direction)
454 {
455  BUG_ON(direction == DMA_NONE);
456 
457  flush_kernel_dcache_range((unsigned long) addr, size);
458  return virt_to_phys(addr);
459 }
460 
461 static void pa11_dma_unmap_single(struct device *dev, dma_addr_t dma_handle, size_t size, enum dma_data_direction direction)
462 {
463  BUG_ON(direction == DMA_NONE);
464 
465  if (direction == DMA_TO_DEVICE)
466  return;
467 
468  /*
469  * For PCI_DMA_FROMDEVICE this flush is not necessary for the
470  * simple map/unmap case. However, it IS necessary if if
471  * pci_dma_sync_single_* has been called and the buffer reused.
472  */
473 
474  flush_kernel_dcache_range((unsigned long) phys_to_virt(dma_handle), size);
475  return;
476 }
477 
478 static int pa11_dma_map_sg(struct device *dev, struct scatterlist *sglist, int nents, enum dma_data_direction direction)
479 {
480  int i;
481 
482  BUG_ON(direction == DMA_NONE);
483 
484  for (i = 0; i < nents; i++, sglist++ ) {
485  unsigned long vaddr = sg_virt_addr(sglist);
486  sg_dma_address(sglist) = (dma_addr_t) virt_to_phys(vaddr);
487  sg_dma_len(sglist) = sglist->length;
488  flush_kernel_dcache_range(vaddr, sglist->length);
489  }
490  return nents;
491 }
492 
493 static void pa11_dma_unmap_sg(struct device *dev, struct scatterlist *sglist, int nents, enum dma_data_direction direction)
494 {
495  int i;
496 
497  BUG_ON(direction == DMA_NONE);
498 
499  if (direction == DMA_TO_DEVICE)
500  return;
501 
502  /* once we do combining we'll need to use phys_to_virt(sg_dma_address(sglist)) */
503 
504  for (i = 0; i < nents; i++, sglist++ )
506  return;
507 }
508 
509 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)
510 {
511  BUG_ON(direction == DMA_NONE);
512 
513  flush_kernel_dcache_range((unsigned long) phys_to_virt(dma_handle) + offset, size);
514 }
515 
516 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)
517 {
518  BUG_ON(direction == DMA_NONE);
519 
520  flush_kernel_dcache_range((unsigned long) phys_to_virt(dma_handle) + offset, size);
521 }
522 
523 static void pa11_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sglist, int nents, enum dma_data_direction direction)
524 {
525  int i;
526 
527  /* once we do combining we'll need to use phys_to_virt(sg_dma_address(sglist)) */
528 
529  for (i = 0; i < nents; i++, sglist++ )
531 }
532 
533 static void pa11_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sglist, int nents, enum dma_data_direction direction)
534 {
535  int i;
536 
537  /* once we do combining we'll need to use phys_to_virt(sg_dma_address(sglist)) */
538 
539  for (i = 0; i < nents; i++, sglist++ )
541 }
542 
544  .dma_supported = pa11_dma_supported,
545  .alloc_consistent = pa11_dma_alloc_consistent,
546  .alloc_noncoherent = pa11_dma_alloc_consistent,
547  .free_consistent = pa11_dma_free_consistent,
548  .map_single = pa11_dma_map_single,
549  .unmap_single = pa11_dma_unmap_single,
550  .map_sg = pa11_dma_map_sg,
551  .unmap_sg = pa11_dma_unmap_sg,
552  .dma_sync_single_for_cpu = pa11_dma_sync_single_for_cpu,
553  .dma_sync_single_for_device = pa11_dma_sync_single_for_device,
554  .dma_sync_sg_for_cpu = pa11_dma_sync_sg_for_cpu,
555  .dma_sync_sg_for_device = pa11_dma_sync_sg_for_device,
556 };
557 
558 static void *fail_alloc_consistent(struct device *dev, size_t size,
559  dma_addr_t *dma_handle, gfp_t flag)
560 {
561  return NULL;
562 }
563 
564 static void *pa11_dma_alloc_noncoherent(struct device *dev, size_t size,
565  dma_addr_t *dma_handle, gfp_t flag)
566 {
567  void *addr;
568 
569  addr = (void *)__get_free_pages(flag, get_order(size));
570  if (addr)
571  *dma_handle = (dma_addr_t)virt_to_phys(addr);
572 
573  return addr;
574 }
575 
576 static void pa11_dma_free_noncoherent(struct device *dev, size_t size,
577  void *vaddr, dma_addr_t iova)
578 {
579  free_pages((unsigned long)vaddr, get_order(size));
580  return;
581 }
582 
584  .dma_supported = pa11_dma_supported,
585  .alloc_consistent = fail_alloc_consistent,
586  .alloc_noncoherent = pa11_dma_alloc_noncoherent,
587  .free_consistent = pa11_dma_free_noncoherent,
588  .map_single = pa11_dma_map_single,
589  .unmap_single = pa11_dma_unmap_single,
590  .map_sg = pa11_dma_map_sg,
591  .unmap_sg = pa11_dma_unmap_sg,
592  .dma_sync_single_for_cpu = pa11_dma_sync_single_for_cpu,
593  .dma_sync_single_for_device = pa11_dma_sync_single_for_device,
594  .dma_sync_sg_for_cpu = pa11_dma_sync_sg_for_cpu,
595  .dma_sync_sg_for_device = pa11_dma_sync_sg_for_device,
596 };