Pull bugzilla-7200 into release branch
[linux-2.6] / arch / xtensa / kernel / pci-dma.c
1 /*
2  * arch/xtensa/pci-dma.c
3  *
4  * DMA coherent memory allocation.
5  *
6  * This program is free software; you can redistribute  it and/or modify it
7  * under  the terms of  the GNU General  Public License as published by the
8  * Free Software Foundation;  either version 2 of the  License, or (at your
9  * option) any later version.
10  *
11  * Copyright (C) 2002 - 2005 Tensilica Inc.
12  *
13  * Based on version for i386.
14  *
15  * Chris Zankel <chris@zankel.net>
16  * Joe Taylor <joe@tensilica.com, joetylr@yahoo.com>
17  */
18
19 #include <linux/types.h>
20 #include <linux/mm.h>
21 #include <linux/string.h>
22 #include <linux/pci.h>
23 #include <asm/io.h>
24 #include <asm/cacheflush.h>
25
26 /*
27  * Note: We assume that the full memory space is always mapped to 'kseg'
28  *       Otherwise we have to use page attributes (not implemented).
29  */
30
31 void *
32 dma_alloc_coherent(struct device *dev,size_t size,dma_addr_t *handle,gfp_t flag)
33 {
34         unsigned long ret;
35         unsigned long uncached = 0;
36
37         /* ignore region speicifiers */
38
39         flag &= ~(__GFP_DMA | __GFP_HIGHMEM);
40
41         if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff))
42                 flag |= GFP_DMA;
43         ret = (unsigned long)__get_free_pages(flag, get_order(size));
44
45         if (ret == 0)
46                 return NULL;
47
48         /* We currently don't support coherent memory outside KSEG */
49
50         if (ret < XCHAL_KSEG_CACHED_VADDR
51             || ret >= XCHAL_KSEG_CACHED_VADDR + XCHAL_KSEG_SIZE)
52                 BUG();
53
54
55         if (ret != 0) {
56                 memset((void*) ret, 0, size);
57                 uncached = ret+XCHAL_KSEG_BYPASS_VADDR-XCHAL_KSEG_CACHED_VADDR;
58                 *handle = virt_to_bus((void*)ret);
59                 __flush_invalidate_dcache_range(ret, size);
60         }
61
62         return (void*)uncached;
63 }
64
65 void dma_free_coherent(struct device *hwdev, size_t size,
66                          void *vaddr, dma_addr_t dma_handle)
67 {
68         long addr=(long)vaddr+XCHAL_KSEG_CACHED_VADDR-XCHAL_KSEG_BYPASS_VADDR;
69
70         if (addr < 0 || addr >= XCHAL_KSEG_SIZE)
71                 BUG();
72
73         free_pages(addr, get_order(size));
74 }
75
76
77 void consistent_sync(void *vaddr, size_t size, int direction)
78 {
79         switch (direction) {
80         case PCI_DMA_NONE:
81                 BUG();
82         case PCI_DMA_FROMDEVICE:        /* invalidate only */
83                 __invalidate_dcache_range((unsigned long)vaddr,
84                                           (unsigned long)size);
85                 break;
86
87         case PCI_DMA_TODEVICE:          /* writeback only */
88         case PCI_DMA_BIDIRECTIONAL:     /* writeback and invalidate */
89                 __flush_invalidate_dcache_range((unsigned long)vaddr,
90                                                 (unsigned long)size);
91                 break;
92         }
93 }