aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/ieee1394/dma.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/ieee1394/dma.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'drivers/ieee1394/dma.c')
-rw-r--r--drivers/ieee1394/dma.c260
1 files changed, 260 insertions, 0 deletions
diff --git a/drivers/ieee1394/dma.c b/drivers/ieee1394/dma.c
new file mode 100644
index 000000000000..758819d1999d
--- /dev/null
+++ b/drivers/ieee1394/dma.c
@@ -0,0 +1,260 @@
1/*
2 * DMA region bookkeeping routines
3 *
4 * Copyright (C) 2002 Maas Digital LLC
5 *
6 * This code is licensed under the GPL. See the file COPYING in the root
7 * directory of the kernel sources for details.
8 */
9
10#include <linux/module.h>
11#include <linux/vmalloc.h>
12#include <linux/slab.h>
13#include <linux/mm.h>
14#include "dma.h"
15
16/* dma_prog_region */
17
18void dma_prog_region_init(struct dma_prog_region *prog)
19{
20 prog->kvirt = NULL;
21 prog->dev = NULL;
22 prog->n_pages = 0;
23 prog->bus_addr = 0;
24}
25
26int dma_prog_region_alloc(struct dma_prog_region *prog, unsigned long n_bytes, struct pci_dev *dev)
27{
28 /* round up to page size */
29 n_bytes = PAGE_ALIGN(n_bytes);
30
31 prog->n_pages = n_bytes >> PAGE_SHIFT;
32
33 prog->kvirt = pci_alloc_consistent(dev, n_bytes, &prog->bus_addr);
34 if (!prog->kvirt) {
35 printk(KERN_ERR "dma_prog_region_alloc: pci_alloc_consistent() failed\n");
36 dma_prog_region_free(prog);
37 return -ENOMEM;
38 }
39
40 prog->dev = dev;
41
42 return 0;
43}
44
45void dma_prog_region_free(struct dma_prog_region *prog)
46{
47 if (prog->kvirt) {
48 pci_free_consistent(prog->dev, prog->n_pages << PAGE_SHIFT, prog->kvirt, prog->bus_addr);
49 }
50
51 prog->kvirt = NULL;
52 prog->dev = NULL;
53 prog->n_pages = 0;
54 prog->bus_addr = 0;
55}
56
57/* dma_region */
58
59void dma_region_init(struct dma_region *dma)
60{
61 dma->kvirt = NULL;
62 dma->dev = NULL;
63 dma->n_pages = 0;
64 dma->n_dma_pages = 0;
65 dma->sglist = NULL;
66}
67
68int dma_region_alloc(struct dma_region *dma, unsigned long n_bytes, struct pci_dev *dev, int direction)
69{
70 unsigned int i;
71
72 /* round up to page size */
73 n_bytes = PAGE_ALIGN(n_bytes);
74
75 dma->n_pages = n_bytes >> PAGE_SHIFT;
76
77 dma->kvirt = vmalloc_32(n_bytes);
78 if (!dma->kvirt) {
79 printk(KERN_ERR "dma_region_alloc: vmalloc_32() failed\n");
80 goto err;
81 }
82
83 /* Clear the ram out, no junk to the user */
84 memset(dma->kvirt, 0, n_bytes);
85
86 /* allocate scatter/gather list */
87 dma->sglist = vmalloc(dma->n_pages * sizeof(*dma->sglist));
88 if (!dma->sglist) {
89 printk(KERN_ERR "dma_region_alloc: vmalloc(sglist) failed\n");
90 goto err;
91 }
92
93 /* just to be safe - this will become unnecessary once sglist->address goes away */
94 memset(dma->sglist, 0, dma->n_pages * sizeof(*dma->sglist));
95
96 /* fill scatter/gather list with pages */
97 for (i = 0; i < dma->n_pages; i++) {
98 unsigned long va = (unsigned long) dma->kvirt + (i << PAGE_SHIFT);
99
100 dma->sglist[i].page = vmalloc_to_page((void *)va);
101 dma->sglist[i].length = PAGE_SIZE;
102 }
103
104 /* map sglist to the IOMMU */
105 dma->n_dma_pages = pci_map_sg(dev, dma->sglist, dma->n_pages, direction);
106
107 if (dma->n_dma_pages == 0) {
108 printk(KERN_ERR "dma_region_alloc: pci_map_sg() failed\n");
109 goto err;
110 }
111
112 dma->dev = dev;
113 dma->direction = direction;
114
115 return 0;
116
117err:
118 dma_region_free(dma);
119 return -ENOMEM;
120}
121
122void dma_region_free(struct dma_region *dma)
123{
124 if (dma->n_dma_pages) {
125 pci_unmap_sg(dma->dev, dma->sglist, dma->n_pages, dma->direction);
126 dma->n_dma_pages = 0;
127 dma->dev = NULL;
128 }
129
130 vfree(dma->sglist);
131 dma->sglist = NULL;
132
133 vfree(dma->kvirt);
134 dma->kvirt = NULL;
135 dma->n_pages = 0;
136}
137
138/* find the scatterlist index and remaining offset corresponding to a
139 given offset from the beginning of the buffer */
140static inline int dma_region_find(struct dma_region *dma, unsigned long offset, unsigned long *rem)
141{
142 int i;
143 unsigned long off = offset;
144
145 for (i = 0; i < dma->n_dma_pages; i++) {
146 if (off < sg_dma_len(&dma->sglist[i])) {
147 *rem = off;
148 break;
149 }
150
151 off -= sg_dma_len(&dma->sglist[i]);
152 }
153
154 BUG_ON(i >= dma->n_dma_pages);
155
156 return i;
157}
158
159dma_addr_t dma_region_offset_to_bus(struct dma_region *dma, unsigned long offset)
160{
161 unsigned long rem;
162
163 struct scatterlist *sg = &dma->sglist[dma_region_find(dma, offset, &rem)];
164 return sg_dma_address(sg) + rem;
165}
166
167void dma_region_sync_for_cpu(struct dma_region *dma, unsigned long offset, unsigned long len)
168{
169 int first, last;
170 unsigned long rem;
171
172 if (!len)
173 len = 1;
174
175 first = dma_region_find(dma, offset, &rem);
176 last = dma_region_find(dma, offset + len - 1, &rem);
177
178 pci_dma_sync_sg_for_cpu(dma->dev, &dma->sglist[first], last - first + 1, dma->direction);
179}
180
181void dma_region_sync_for_device(struct dma_region *dma, unsigned long offset, unsigned long len)
182{
183 int first, last;
184 unsigned long rem;
185
186 if (!len)
187 len = 1;
188
189 first = dma_region_find(dma, offset, &rem);
190 last = dma_region_find(dma, offset + len - 1, &rem);
191
192 pci_dma_sync_sg_for_device(dma->dev, &dma->sglist[first], last - first + 1, dma->direction);
193}
194
195#ifdef CONFIG_MMU
196
197/* nopage() handler for mmap access */
198
199static struct page*
200dma_region_pagefault(struct vm_area_struct *area, unsigned long address, int *type)
201{
202 unsigned long offset;
203 unsigned long kernel_virt_addr;
204 struct page *ret = NOPAGE_SIGBUS;
205
206 struct dma_region *dma = (struct dma_region*) area->vm_private_data;
207
208 if (!dma->kvirt)
209 goto out;
210
211 if ( (address < (unsigned long) area->vm_start) ||
212 (address > (unsigned long) area->vm_start + (dma->n_pages << PAGE_SHIFT)) )
213 goto out;
214
215 if (type)
216 *type = VM_FAULT_MINOR;
217 offset = address - area->vm_start;
218 kernel_virt_addr = (unsigned long) dma->kvirt + offset;
219 ret = vmalloc_to_page((void*) kernel_virt_addr);
220 get_page(ret);
221out:
222 return ret;
223}
224
225static struct vm_operations_struct dma_region_vm_ops = {
226 .nopage = dma_region_pagefault,
227};
228
229int dma_region_mmap(struct dma_region *dma, struct file *file, struct vm_area_struct *vma)
230{
231 unsigned long size;
232
233 if (!dma->kvirt)
234 return -EINVAL;
235
236 /* must be page-aligned */
237 if (vma->vm_pgoff != 0)
238 return -EINVAL;
239
240 /* check the length */
241 size = vma->vm_end - vma->vm_start;
242 if (size > (dma->n_pages << PAGE_SHIFT))
243 return -EINVAL;
244
245 vma->vm_ops = &dma_region_vm_ops;
246 vma->vm_private_data = dma;
247 vma->vm_file = file;
248 vma->vm_flags |= VM_RESERVED;
249
250 return 0;
251}
252
253#else /* CONFIG_MMU */
254
255int dma_region_mmap(struct dma_region *dma, struct file *file, struct vm_area_struct *vma)
256{
257 return -EINVAL;
258}
259
260#endif /* CONFIG_MMU */