ia64/linux-2.6.18-xen.hg

view arch/ia64/xen/xen_dma.c @ 708:e410857fd83c

Remove contiguous_bitmap[] as it's no longer needed.

Signed-off-by: Keir Fraser <keir.fraser@citrix.com>
author Keir Fraser <keir.fraser@citrix.com>
date Wed Oct 22 14:55:29 2008 +0100 (2008-10-22)
parents ec6e3e18ea31
children
line source
1 /*
2 * Copyright (C) 2007 Hewlett-Packard Development Company, L.P.
3 * Alex Williamson <alex.williamson@hp.com>
4 *
5 * Basic DMA mapping services for Xen guests.
6 * Based on arch/i386/kernel/pci-dma-xen.c.
7 *
8 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
23 */
25 #include <linux/bitops.h>
26 #include <linux/dma-mapping.h>
27 #include <linux/mm.h>
28 #include <asm/scatterlist.h>
29 #include <xen/gnttab.h>
30 #include <asm/gnttab_dma.h>
32 #define IOMMU_BUG_ON(test) \
33 do { \
34 if (unlikely(test)) { \
35 printk(KERN_ALERT "Fatal DMA error!\n"); \
36 BUG(); \
37 } \
38 } while (0)
40 static int check_pages_physically_contiguous(unsigned long pfn,
41 unsigned int offset,
42 size_t length)
43 {
44 unsigned long next_bus;
45 int i;
46 int nr_pages;
48 next_bus = pfn_to_mfn_for_dma(pfn);
49 nr_pages = (offset + length + PAGE_SIZE-1) >> PAGE_SHIFT;
51 for (i = 1; i < nr_pages; i++) {
52 if (pfn_to_mfn_for_dma(++pfn) != ++next_bus)
53 return 0;
54 }
55 return 1;
56 }
58 int range_straddles_page_boundary(paddr_t p, size_t size)
59 {
60 unsigned long pfn = p >> PAGE_SHIFT;
61 unsigned int offset = p & ~PAGE_MASK;
63 if (!is_running_on_xen())
64 return 0;
66 if (offset + size <= PAGE_SIZE)
67 return 0;
68 if (check_pages_physically_contiguous(pfn, offset, size))
69 return 0;
70 return 1;
71 }
73 /*
74 * This should be broken out of swiotlb and put in a common place
75 * when merged with upstream Linux.
76 */
77 static inline int
78 address_needs_mapping(struct device *dev, dma_addr_t addr)
79 {
80 dma_addr_t mask = 0xffffffff;
82 /* If the device has a mask, use it, otherwise default to 32 bits */
83 if (dev && dev->dma_mask)
84 mask = *dev->dma_mask;
85 return (addr & ~mask) != 0;
86 }
88 int
89 xen_map_sg(struct device *dev, struct scatterlist *sg, int nents,
90 int direction)
91 {
92 int i;
94 for (i = 0 ; i < nents ; i++) {
95 sg[i].dma_address = gnttab_dma_map_page(sg[i].page) + sg[i].offset;
96 sg[i].dma_length = sg[i].length;
98 IOMMU_BUG_ON(address_needs_mapping(dev, sg[i].dma_address));
99 IOMMU_BUG_ON(range_straddles_page_boundary(
100 page_to_pseudophys(sg[i].page) + sg[i].offset,
101 sg[i].length));
102 }
104 return nents;
105 }
106 EXPORT_SYMBOL(xen_map_sg);
108 void
109 xen_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
110 int direction)
111 {
112 int i;
113 for (i = 0; i < nents; i++)
114 __gnttab_dma_unmap_page(sg[i].page);
115 }
116 EXPORT_SYMBOL(xen_unmap_sg);
118 int
119 xen_dma_mapping_error(dma_addr_t dma_addr)
120 {
121 return 0;
122 }
123 EXPORT_SYMBOL(xen_dma_mapping_error);
125 int
126 xen_dma_supported(struct device *dev, u64 mask)
127 {
128 return 1;
129 }
130 EXPORT_SYMBOL(xen_dma_supported);
132 void *
133 xen_alloc_coherent(struct device *dev, size_t size,
134 dma_addr_t *dma_handle, gfp_t gfp)
135 {
136 unsigned long vaddr;
137 unsigned int order = get_order(size);
139 vaddr = __get_free_pages(gfp, order);
141 if (!vaddr)
142 return NULL;
144 if (xen_create_contiguous_region(vaddr, order,
145 fls64(dev->coherent_dma_mask))) {
146 free_pages(vaddr, order);
147 return NULL;
148 }
150 memset((void *)vaddr, 0, size);
151 *dma_handle = virt_to_bus((void *)vaddr);
153 return (void *)vaddr;
154 }
155 EXPORT_SYMBOL(xen_alloc_coherent);
157 void
158 xen_free_coherent(struct device *dev, size_t size,
159 void *vaddr, dma_addr_t dma_handle)
160 {
161 unsigned int order = get_order(size);
163 xen_destroy_contiguous_region((unsigned long)vaddr, order);
164 free_pages((unsigned long)vaddr, order);
165 }
166 EXPORT_SYMBOL(xen_free_coherent);
168 dma_addr_t
169 xen_map_single(struct device *dev, void *ptr, size_t size,
170 int direction)
171 {
172 dma_addr_t dma_addr = gnttab_dma_map_virt(ptr);
174 IOMMU_BUG_ON(range_straddles_page_boundary(__pa(ptr), size));
175 IOMMU_BUG_ON(address_needs_mapping(dev, dma_addr));
177 return dma_addr;
178 }
179 EXPORT_SYMBOL(xen_map_single);
181 void
182 xen_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
183 int direction)
184 {
185 gnttab_dma_unmap_page(dma_addr);
186 }
187 EXPORT_SYMBOL(xen_unmap_single);