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Commit | Line | Data |
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1da177e4 LT |
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 | ||
de4394f1 | 10 | #include <linux/mm.h> |
1da177e4 | 11 | #include <linux/module.h> |
de4394f1 | 12 | #include <linux/pci.h> |
de4394f1 | 13 | #include <linux/vmalloc.h> |
11763609 | 14 | #include <linux/scatterlist.h> |
de4394f1 | 15 | |
1da177e4 LT |
16 | #include "dma.h" |
17 | ||
18 | /* dma_prog_region */ | |
19 | ||
20 | void dma_prog_region_init(struct dma_prog_region *prog) | |
21 | { | |
22 | prog->kvirt = NULL; | |
23 | prog->dev = NULL; | |
24 | prog->n_pages = 0; | |
25 | prog->bus_addr = 0; | |
26 | } | |
27 | ||
6649e92d JMH |
28 | int dma_prog_region_alloc(struct dma_prog_region *prog, unsigned long n_bytes, |
29 | struct pci_dev *dev) | |
1da177e4 LT |
30 | { |
31 | /* round up to page size */ | |
32 | n_bytes = PAGE_ALIGN(n_bytes); | |
33 | ||
34 | prog->n_pages = n_bytes >> PAGE_SHIFT; | |
35 | ||
36 | prog->kvirt = pci_alloc_consistent(dev, n_bytes, &prog->bus_addr); | |
37 | if (!prog->kvirt) { | |
6649e92d JMH |
38 | printk(KERN_ERR |
39 | "dma_prog_region_alloc: pci_alloc_consistent() failed\n"); | |
1da177e4 LT |
40 | dma_prog_region_free(prog); |
41 | return -ENOMEM; | |
42 | } | |
43 | ||
44 | prog->dev = dev; | |
45 | ||
46 | return 0; | |
47 | } | |
48 | ||
49 | void dma_prog_region_free(struct dma_prog_region *prog) | |
50 | { | |
51 | if (prog->kvirt) { | |
6649e92d JMH |
52 | pci_free_consistent(prog->dev, prog->n_pages << PAGE_SHIFT, |
53 | prog->kvirt, prog->bus_addr); | |
1da177e4 LT |
54 | } |
55 | ||
56 | prog->kvirt = NULL; | |
57 | prog->dev = NULL; | |
58 | prog->n_pages = 0; | |
59 | prog->bus_addr = 0; | |
60 | } | |
61 | ||
62 | /* dma_region */ | |
63 | ||
afd6546d SR |
64 | /** |
65 | * dma_region_init - clear out all fields but do not allocate anything | |
66 | */ | |
1da177e4 LT |
67 | void dma_region_init(struct dma_region *dma) |
68 | { | |
69 | dma->kvirt = NULL; | |
70 | dma->dev = NULL; | |
71 | dma->n_pages = 0; | |
72 | dma->n_dma_pages = 0; | |
73 | dma->sglist = NULL; | |
74 | } | |
75 | ||
afd6546d SR |
76 | /** |
77 | * dma_region_alloc - allocate the buffer and map it to the IOMMU | |
78 | */ | |
6649e92d JMH |
79 | int dma_region_alloc(struct dma_region *dma, unsigned long n_bytes, |
80 | struct pci_dev *dev, int direction) | |
1da177e4 LT |
81 | { |
82 | unsigned int i; | |
83 | ||
84 | /* round up to page size */ | |
85 | n_bytes = PAGE_ALIGN(n_bytes); | |
86 | ||
87 | dma->n_pages = n_bytes >> PAGE_SHIFT; | |
88 | ||
89 | dma->kvirt = vmalloc_32(n_bytes); | |
90 | if (!dma->kvirt) { | |
91 | printk(KERN_ERR "dma_region_alloc: vmalloc_32() failed\n"); | |
92 | goto err; | |
93 | } | |
94 | ||
95 | /* Clear the ram out, no junk to the user */ | |
96 | memset(dma->kvirt, 0, n_bytes); | |
97 | ||
98 | /* allocate scatter/gather list */ | |
99 | dma->sglist = vmalloc(dma->n_pages * sizeof(*dma->sglist)); | |
100 | if (!dma->sglist) { | |
101 | printk(KERN_ERR "dma_region_alloc: vmalloc(sglist) failed\n"); | |
102 | goto err; | |
103 | } | |
104 | ||
9e66269d | 105 | sg_init_table(dma->sglist, dma->n_pages); |
1da177e4 LT |
106 | |
107 | /* fill scatter/gather list with pages */ | |
108 | for (i = 0; i < dma->n_pages; i++) { | |
6649e92d JMH |
109 | unsigned long va = |
110 | (unsigned long)dma->kvirt + (i << PAGE_SHIFT); | |
1da177e4 | 111 | |
642f1490 JA |
112 | sg_set_page(&dma->sglist[i], vmalloc_to_page((void *)va), |
113 | PAGE_SIZE, 0); | |
1da177e4 LT |
114 | } |
115 | ||
116 | /* map sglist to the IOMMU */ | |
6649e92d JMH |
117 | dma->n_dma_pages = |
118 | pci_map_sg(dev, dma->sglist, dma->n_pages, direction); | |
1da177e4 LT |
119 | |
120 | if (dma->n_dma_pages == 0) { | |
121 | printk(KERN_ERR "dma_region_alloc: pci_map_sg() failed\n"); | |
122 | goto err; | |
123 | } | |
124 | ||
125 | dma->dev = dev; | |
126 | dma->direction = direction; | |
127 | ||
128 | return 0; | |
129 | ||
6649e92d | 130 | err: |
1da177e4 LT |
131 | dma_region_free(dma); |
132 | return -ENOMEM; | |
133 | } | |
134 | ||
afd6546d SR |
135 | /** |
136 | * dma_region_free - unmap and free the buffer | |
137 | */ | |
1da177e4 LT |
138 | void dma_region_free(struct dma_region *dma) |
139 | { | |
140 | if (dma->n_dma_pages) { | |
6649e92d JMH |
141 | pci_unmap_sg(dma->dev, dma->sglist, dma->n_pages, |
142 | dma->direction); | |
1da177e4 LT |
143 | dma->n_dma_pages = 0; |
144 | dma->dev = NULL; | |
145 | } | |
146 | ||
147 | vfree(dma->sglist); | |
148 | dma->sglist = NULL; | |
149 | ||
150 | vfree(dma->kvirt); | |
151 | dma->kvirt = NULL; | |
152 | dma->n_pages = 0; | |
153 | } | |
154 | ||
155 | /* find the scatterlist index and remaining offset corresponding to a | |
156 | given offset from the beginning of the buffer */ | |
6649e92d | 157 | static inline int dma_region_find(struct dma_region *dma, unsigned long offset, |
9bb2bcdb | 158 | unsigned int start, unsigned long *rem) |
1da177e4 LT |
159 | { |
160 | int i; | |
161 | unsigned long off = offset; | |
162 | ||
9bb2bcdb | 163 | for (i = start; i < dma->n_dma_pages; i++) { |
1da177e4 LT |
164 | if (off < sg_dma_len(&dma->sglist[i])) { |
165 | *rem = off; | |
166 | break; | |
167 | } | |
168 | ||
169 | off -= sg_dma_len(&dma->sglist[i]); | |
170 | } | |
171 | ||
172 | BUG_ON(i >= dma->n_dma_pages); | |
173 | ||
174 | return i; | |
175 | } | |
176 | ||
afd6546d SR |
177 | /** |
178 | * dma_region_offset_to_bus - get bus address of an offset within a DMA region | |
179 | * | |
180 | * Returns the DMA bus address of the byte with the given @offset relative to | |
181 | * the beginning of the @dma. | |
182 | */ | |
6649e92d JMH |
183 | dma_addr_t dma_region_offset_to_bus(struct dma_region * dma, |
184 | unsigned long offset) | |
1da177e4 | 185 | { |
1934b8b6 | 186 | unsigned long rem = 0; |
1da177e4 | 187 | |
6649e92d | 188 | struct scatterlist *sg = |
9bb2bcdb | 189 | &dma->sglist[dma_region_find(dma, offset, 0, &rem)]; |
1da177e4 LT |
190 | return sg_dma_address(sg) + rem; |
191 | } | |
192 | ||
afd6546d SR |
193 | /** |
194 | * dma_region_sync_for_cpu - sync the CPU's view of the buffer | |
195 | */ | |
6649e92d JMH |
196 | void dma_region_sync_for_cpu(struct dma_region *dma, unsigned long offset, |
197 | unsigned long len) | |
1da177e4 LT |
198 | { |
199 | int first, last; | |
9bb2bcdb | 200 | unsigned long rem = 0; |
1da177e4 LT |
201 | |
202 | if (!len) | |
203 | len = 1; | |
204 | ||
9bb2bcdb BC |
205 | first = dma_region_find(dma, offset, 0, &rem); |
206 | last = dma_region_find(dma, rem + len - 1, first, &rem); | |
1da177e4 | 207 | |
6649e92d JMH |
208 | pci_dma_sync_sg_for_cpu(dma->dev, &dma->sglist[first], last - first + 1, |
209 | dma->direction); | |
1da177e4 LT |
210 | } |
211 | ||
afd6546d SR |
212 | /** |
213 | * dma_region_sync_for_device - sync the IO bus' view of the buffer | |
214 | */ | |
6649e92d JMH |
215 | void dma_region_sync_for_device(struct dma_region *dma, unsigned long offset, |
216 | unsigned long len) | |
1da177e4 LT |
217 | { |
218 | int first, last; | |
9bb2bcdb | 219 | unsigned long rem = 0; |
1da177e4 LT |
220 | |
221 | if (!len) | |
222 | len = 1; | |
223 | ||
9bb2bcdb BC |
224 | first = dma_region_find(dma, offset, 0, &rem); |
225 | last = dma_region_find(dma, rem + len - 1, first, &rem); | |
1da177e4 | 226 | |
6649e92d JMH |
227 | pci_dma_sync_sg_for_device(dma->dev, &dma->sglist[first], |
228 | last - first + 1, dma->direction); | |
1da177e4 LT |
229 | } |
230 | ||
231 | #ifdef CONFIG_MMU | |
232 | ||
61db8121 | 233 | static int dma_region_pagefault(struct vm_area_struct *vma, |
c7ea990f | 234 | struct vm_fault *vmf) |
1da177e4 | 235 | { |
61db8121 | 236 | struct dma_region *dma = (struct dma_region *)vma->vm_private_data; |
1da177e4 LT |
237 | |
238 | if (!dma->kvirt) | |
c7ea990f | 239 | return VM_FAULT_SIGBUS; |
61db8121 NP |
240 | |
241 | if (vmf->pgoff >= dma->n_pages) | |
c7ea990f | 242 | return VM_FAULT_SIGBUS; |
61db8121 | 243 | |
c7ea990f | 244 | vmf->page = vmalloc_to_page(dma->kvirt + (vmf->pgoff << PAGE_SHIFT)); |
61db8121 NP |
245 | get_page(vmf->page); |
246 | return 0; | |
1da177e4 LT |
247 | } |
248 | ||
f0f37e2f | 249 | static const struct vm_operations_struct dma_region_vm_ops = { |
61db8121 | 250 | .fault = dma_region_pagefault, |
1da177e4 LT |
251 | }; |
252 | ||
afd6546d SR |
253 | /** |
254 | * dma_region_mmap - map the buffer into a user space process | |
255 | */ | |
6649e92d JMH |
256 | int dma_region_mmap(struct dma_region *dma, struct file *file, |
257 | struct vm_area_struct *vma) | |
1da177e4 LT |
258 | { |
259 | unsigned long size; | |
260 | ||
261 | if (!dma->kvirt) | |
262 | return -EINVAL; | |
263 | ||
61db8121 | 264 | /* must be page-aligned (XXX: comment is wrong, we could allow pgoff) */ |
1da177e4 LT |
265 | if (vma->vm_pgoff != 0) |
266 | return -EINVAL; | |
267 | ||
268 | /* check the length */ | |
269 | size = vma->vm_end - vma->vm_start; | |
270 | if (size > (dma->n_pages << PAGE_SHIFT)) | |
271 | return -EINVAL; | |
272 | ||
273 | vma->vm_ops = &dma_region_vm_ops; | |
274 | vma->vm_private_data = dma; | |
275 | vma->vm_file = file; | |
435f9726 | 276 | vma->vm_flags |= VM_RESERVED | VM_ALWAYSDUMP; |
1da177e4 LT |
277 | |
278 | return 0; | |
279 | } | |
280 | ||
6649e92d | 281 | #else /* CONFIG_MMU */ |
1da177e4 | 282 | |
6649e92d JMH |
283 | int dma_region_mmap(struct dma_region *dma, struct file *file, |
284 | struct vm_area_struct *vma) | |
1da177e4 LT |
285 | { |
286 | return -EINVAL; | |
287 | } | |
288 | ||
6649e92d | 289 | #endif /* CONFIG_MMU */ |