USB: cdc-acm: fix possible deadlock with multiple openers
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / arch / parisc / kernel / pci-dma.c
blobc07f618ff7da9264fc9aa242cfaf1515b72d8af5
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
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)
15 ** AFAIK, all PA7100LC and PA7300LC platforms can use this code.
17 ** - ggg
20 #include <linux/init.h>
21 #include <linux/mm.h>
22 #include <linux/pci.h>
23 #include <linux/proc_fs.h>
24 #include <linux/seq_file.h>
25 #include <linux/slab.h>
26 #include <linux/string.h>
27 #include <linux/types.h>
28 #include <linux/scatterlist.h>
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 */
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;
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;
48 #ifdef DEBUG_PCXL_RESOURCE
49 #define DBG_RES(x...) printk(x)
50 #else
51 #define DBG_RES(x...)
52 #endif
56 ** Dump a hex representation of the resource map.
59 #ifdef DUMP_RESMAP
60 static
61 void dump_resmap(void)
63 u_long *res_ptr = (unsigned long *)pcxl_res_map;
64 u_long i = 0;
66 printk("res_map: ");
67 for(; i < (pcxl_res_size / sizeof(unsigned long)); ++i, ++res_ptr)
68 printk("%08lx ", *res_ptr);
70 printk("\n");
72 #else
73 static inline void dump_resmap(void) {;}
74 #endif
76 static int pa11_dma_supported( struct device *dev, u64 mask)
78 return 1;
81 static inline int map_pte_uncached(pte_t * pte,
82 unsigned long vaddr,
83 unsigned long size, unsigned long *paddr_ptr)
85 unsigned long end;
86 unsigned long orig_vaddr = vaddr;
88 vaddr &= ~PMD_MASK;
89 end = vaddr + size;
90 if (end > PMD_SIZE)
91 end = PMD_SIZE;
92 do {
93 unsigned long flags;
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;
109 static inline int map_pmd_uncached(pmd_t * pmd, unsigned long vaddr,
110 unsigned long size, unsigned long *paddr_ptr)
112 unsigned long end;
113 unsigned long orig_vaddr = vaddr;
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;
132 static inline int map_uncached_pages(unsigned long vaddr, unsigned long size,
133 unsigned long paddr)
135 pgd_t * dir;
136 unsigned long end = vaddr + size;
138 dir = pgd_offset_k(vaddr);
139 do {
140 pmd_t *pmd;
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;
153 static inline void unmap_uncached_pte(pmd_t * pmd, unsigned long vaddr,
154 unsigned long size)
156 pte_t * pte;
157 unsigned long end;
158 unsigned long orig_vaddr = vaddr;
160 if (pmd_none(*pmd))
161 return;
162 if (pmd_bad(*pmd)) {
163 pmd_ERROR(*pmd);
164 pmd_clear(pmd);
165 return;
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;
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);
189 static inline void unmap_uncached_pmd(pgd_t * dir, unsigned long vaddr,
190 unsigned long size)
192 pmd_t * pmd;
193 unsigned long end;
194 unsigned long orig_vaddr = vaddr;
196 if (pgd_none(*dir))
197 return;
198 if (pgd_bad(*dir)) {
199 pgd_ERROR(*dir);
200 pgd_clear(dir);
201 return;
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);
216 static void unmap_uncached_pages(unsigned long vaddr, unsigned long size)
218 pgd_t * dir;
219 unsigned long end = vaddr + size;
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));
229 #define PCXL_SEARCH_LOOP(idx, mask, size) \
230 for(; res_ptr < res_end; ++res_ptr) \
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; \
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); \
248 unsigned long
249 pcxl_alloc_range(size_t size)
251 int res_idx;
252 u_long mask, flags;
253 unsigned int pages_needed = size >> PAGE_SHIFT;
255 mask = (u_long) -1L;
256 mask >>= BITS_PER_LONG - pages_needed;
258 DBG_RES("pcxl_alloc_range() size: %d pages_needed %d pages_mask 0x%08lx\n",
259 size, pages_needed, mask);
261 spin_lock_irqsave(&pcxl_res_lock, flags);
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__);
274 dump_resmap();
275 panic("%s: pcxl_alloc_range() out of dma mapping resources\n",
276 __FILE__);
278 resource_found:
280 DBG_RES("pcxl_alloc_range() res_idx %d mask 0x%08lx res_hint: %d\n",
281 res_idx, mask, pcxl_res_hint);
283 pcxl_used_pages += pages_needed;
284 pcxl_used_bytes += ((pages_needed >> 3) ? (pages_needed >> 3) : 1);
286 spin_unlock_irqrestore(&pcxl_res_lock, flags);
288 dump_resmap();
291 ** return the corresponding vaddr in the pcxl dma map
293 return (pcxl_dma_start + (res_idx << (PAGE_SHIFT + 3)));
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;
302 ** clear bits in the pcxl resource map
304 static void
305 pcxl_free_range(unsigned long vaddr, size_t size)
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;
311 mask = (u_long) -1L;
312 mask >>= BITS_PER_LONG - pages_mapped;
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);
317 spin_lock_irqsave(&pcxl_res_lock, flags);
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__);
330 pcxl_used_pages -= (pages_mapped ? pages_mapped : 1);
331 pcxl_used_bytes -= ((pages_mapped >> 3) ? (pages_mapped >> 3) : 1);
333 spin_unlock_irqrestore(&pcxl_res_lock, flags);
335 dump_resmap();
338 static int proc_pcxl_dma_show(struct seq_file *m, void *v)
340 #if 0
341 u_long i = 0;
342 unsigned long *res_ptr = (u_long *)pcxl_res_map;
343 #endif
344 unsigned long total_pages = pcxl_res_size << 3; /* 8 bits per byte */
346 seq_printf(m, "\nDMA Mapping Area size : %d bytes (%ld pages)\n",
347 PCXL_DMA_MAP_SIZE, total_pages);
349 seq_printf(m, "Resource bitmap : %d bytes\n", pcxl_res_size);
351 seq_puts(m, " total: free: used: % used:\n");
352 seq_printf(m, "blocks %8d %8ld %8ld %8ld%%\n", pcxl_res_size,
353 pcxl_res_size - pcxl_used_bytes, pcxl_used_bytes,
354 (pcxl_used_bytes * 100) / pcxl_res_size);
356 seq_printf(m, "pages %8ld %8ld %8ld %8ld%%\n", total_pages,
357 total_pages - pcxl_used_pages, pcxl_used_pages,
358 (pcxl_used_pages * 100 / total_pages));
360 #if 0
361 seq_puts(m, "\nResource bitmap:");
363 for(; i < (pcxl_res_size / sizeof(u_long)); ++i, ++res_ptr) {
364 if ((i & 7) == 0)
365 seq_puts(m,"\n ");
366 seq_printf(m, "%s %08lx", buf, *res_ptr);
368 #endif
369 seq_putc(m, '\n');
370 return 0;
373 static int proc_pcxl_dma_open(struct inode *inode, struct file *file)
375 return single_open(file, proc_pcxl_dma_show, NULL);
378 static const struct file_operations proc_pcxl_dma_ops = {
379 .owner = THIS_MODULE,
380 .open = proc_pcxl_dma_open,
381 .read = seq_read,
382 .llseek = seq_lseek,
383 .release = single_release,
386 static int __init
387 pcxl_dma_init(void)
389 if (pcxl_dma_start == 0)
390 return 0;
392 spin_lock_init(&pcxl_res_lock);
393 pcxl_res_size = PCXL_DMA_MAP_SIZE >> (PAGE_SHIFT + 3);
394 pcxl_res_hint = 0;
395 pcxl_res_map = (char *)__get_free_pages(GFP_KERNEL,
396 get_order(pcxl_res_size));
397 memset(pcxl_res_map, 0, pcxl_res_size);
398 proc_gsc_root = proc_mkdir("gsc", NULL);
399 if (!proc_gsc_root)
400 printk(KERN_WARNING
401 "pcxl_dma_init: Unable to create gsc /proc dir entry\n");
402 else {
403 struct proc_dir_entry* ent;
404 ent = proc_create("pcxl_dma", 0, proc_gsc_root,
405 &proc_pcxl_dma_ops);
406 if (!ent)
407 printk(KERN_WARNING
408 "pci-dma.c: Unable to create pcxl_dma /proc entry.\n");
410 return 0;
413 __initcall(pcxl_dma_init);
415 static void * pa11_dma_alloc_consistent (struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t flag)
417 unsigned long vaddr;
418 unsigned long paddr;
419 int order;
421 order = get_order(size);
422 size = 1 << (order + PAGE_SHIFT);
423 vaddr = pcxl_alloc_range(size);
424 paddr = __get_free_pages(flag, order);
425 flush_kernel_dcache_range(paddr, size);
426 paddr = __pa(paddr);
427 map_uncached_pages(vaddr, size, paddr);
428 *dma_handle = (dma_addr_t) paddr;
430 #if 0
431 /* This probably isn't needed to support EISA cards.
432 ** ISA cards will certainly only support 24-bit DMA addressing.
433 ** Not clear if we can, want, or need to support ISA.
435 if (!dev || *dev->coherent_dma_mask < 0xffffffff)
436 gfp |= GFP_DMA;
437 #endif
438 return (void *)vaddr;
441 static void pa11_dma_free_consistent (struct device *dev, size_t size, void *vaddr, dma_addr_t dma_handle)
443 int order;
445 order = get_order(size);
446 size = 1 << (order + PAGE_SHIFT);
447 unmap_uncached_pages((unsigned long)vaddr, size);
448 pcxl_free_range((unsigned long)vaddr, size);
449 free_pages((unsigned long)__va(dma_handle), order);
452 static dma_addr_t pa11_dma_map_single(struct device *dev, void *addr, size_t size, enum dma_data_direction direction)
454 BUG_ON(direction == DMA_NONE);
456 flush_kernel_dcache_range((unsigned long) addr, size);
457 return virt_to_phys(addr);
460 static void pa11_dma_unmap_single(struct device *dev, dma_addr_t dma_handle, size_t size, enum dma_data_direction direction)
462 BUG_ON(direction == DMA_NONE);
464 if (direction == DMA_TO_DEVICE)
465 return;
468 * For PCI_DMA_FROMDEVICE this flush is not necessary for the
469 * simple map/unmap case. However, it IS necessary if if
470 * pci_dma_sync_single_* has been called and the buffer reused.
473 flush_kernel_dcache_range((unsigned long) phys_to_virt(dma_handle), size);
474 return;
477 static int pa11_dma_map_sg(struct device *dev, struct scatterlist *sglist, int nents, enum dma_data_direction direction)
479 int i;
481 BUG_ON(direction == DMA_NONE);
483 for (i = 0; i < nents; i++, sglist++ ) {
484 unsigned long vaddr = sg_virt_addr(sglist);
485 sg_dma_address(sglist) = (dma_addr_t) virt_to_phys(vaddr);
486 sg_dma_len(sglist) = sglist->length;
487 flush_kernel_dcache_range(vaddr, sglist->length);
489 return nents;
492 static void pa11_dma_unmap_sg(struct device *dev, struct scatterlist *sglist, int nents, enum dma_data_direction direction)
494 int i;
496 BUG_ON(direction == DMA_NONE);
498 if (direction == DMA_TO_DEVICE)
499 return;
501 /* once we do combining we'll need to use phys_to_virt(sg_dma_address(sglist)) */
503 for (i = 0; i < nents; i++, sglist++ )
504 flush_kernel_dcache_range(sg_virt_addr(sglist), sglist->length);
505 return;
508 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 BUG_ON(direction == DMA_NONE);
512 flush_kernel_dcache_range((unsigned long) phys_to_virt(dma_handle) + offset, size);
515 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 BUG_ON(direction == DMA_NONE);
519 flush_kernel_dcache_range((unsigned long) phys_to_virt(dma_handle) + offset, size);
522 static void pa11_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sglist, int nents, enum dma_data_direction direction)
524 int i;
526 /* once we do combining we'll need to use phys_to_virt(sg_dma_address(sglist)) */
528 for (i = 0; i < nents; i++, sglist++ )
529 flush_kernel_dcache_range(sg_virt_addr(sglist), sglist->length);
532 static void pa11_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sglist, int nents, enum dma_data_direction direction)
534 int i;
536 /* once we do combining we'll need to use phys_to_virt(sg_dma_address(sglist)) */
538 for (i = 0; i < nents; i++, sglist++ )
539 flush_kernel_dcache_range(sg_virt_addr(sglist), sglist->length);
542 struct hppa_dma_ops pcxl_dma_ops = {
543 .dma_supported = pa11_dma_supported,
544 .alloc_consistent = pa11_dma_alloc_consistent,
545 .alloc_noncoherent = pa11_dma_alloc_consistent,
546 .free_consistent = pa11_dma_free_consistent,
547 .map_single = pa11_dma_map_single,
548 .unmap_single = pa11_dma_unmap_single,
549 .map_sg = pa11_dma_map_sg,
550 .unmap_sg = pa11_dma_unmap_sg,
551 .dma_sync_single_for_cpu = pa11_dma_sync_single_for_cpu,
552 .dma_sync_single_for_device = pa11_dma_sync_single_for_device,
553 .dma_sync_sg_for_cpu = pa11_dma_sync_sg_for_cpu,
554 .dma_sync_sg_for_device = pa11_dma_sync_sg_for_device,
557 static void *fail_alloc_consistent(struct device *dev, size_t size,
558 dma_addr_t *dma_handle, gfp_t flag)
560 return NULL;
563 static void *pa11_dma_alloc_noncoherent(struct device *dev, size_t size,
564 dma_addr_t *dma_handle, gfp_t flag)
566 void *addr;
568 addr = (void *)__get_free_pages(flag, get_order(size));
569 if (addr)
570 *dma_handle = (dma_addr_t)virt_to_phys(addr);
572 return addr;
575 static void pa11_dma_free_noncoherent(struct device *dev, size_t size,
576 void *vaddr, dma_addr_t iova)
578 free_pages((unsigned long)vaddr, get_order(size));
579 return;
582 struct hppa_dma_ops pcx_dma_ops = {
583 .dma_supported = pa11_dma_supported,
584 .alloc_consistent = fail_alloc_consistent,
585 .alloc_noncoherent = pa11_dma_alloc_noncoherent,
586 .free_consistent = pa11_dma_free_noncoherent,
587 .map_single = pa11_dma_map_single,
588 .unmap_single = pa11_dma_unmap_single,
589 .map_sg = pa11_dma_map_sg,
590 .unmap_sg = pa11_dma_unmap_sg,
591 .dma_sync_single_for_cpu = pa11_dma_sync_single_for_cpu,
592 .dma_sync_single_for_device = pa11_dma_sync_single_for_device,
593 .dma_sync_sg_for_cpu = pa11_dma_sync_sg_for_cpu,
594 .dma_sync_sg_for_device = pa11_dma_sync_sg_for_device,