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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> |
1da177e4 | 13 | #include <linux/slab.h> |
de4394f1 SR |
14 | #include <linux/vmalloc.h> |
15 | #include <asm/scatterlist.h> | |
16 | ||
1da177e4 LT |
17 | #include "dma.h" |
18 | ||
19 | /* dma_prog_region */ | |
20 | ||
21 | void dma_prog_region_init(struct dma_prog_region *prog) | |
22 | { | |
23 | prog->kvirt = NULL; | |
24 | prog->dev = NULL; | |
25 | prog->n_pages = 0; | |
26 | prog->bus_addr = 0; | |
27 | } | |
28 | ||
6649e92d JMH |
29 | int dma_prog_region_alloc(struct dma_prog_region *prog, unsigned long n_bytes, |
30 | struct pci_dev *dev) | |
1da177e4 LT |
31 | { |
32 | /* round up to page size */ | |
33 | n_bytes = PAGE_ALIGN(n_bytes); | |
34 | ||
35 | prog->n_pages = n_bytes >> PAGE_SHIFT; | |
36 | ||
37 | prog->kvirt = pci_alloc_consistent(dev, n_bytes, &prog->bus_addr); | |
38 | if (!prog->kvirt) { | |
6649e92d JMH |
39 | printk(KERN_ERR |
40 | "dma_prog_region_alloc: pci_alloc_consistent() failed\n"); | |
1da177e4 LT |
41 | dma_prog_region_free(prog); |
42 | return -ENOMEM; | |
43 | } | |
44 | ||
45 | prog->dev = dev; | |
46 | ||
47 | return 0; | |
48 | } | |
49 | ||
50 | void dma_prog_region_free(struct dma_prog_region *prog) | |
51 | { | |
52 | if (prog->kvirt) { | |
6649e92d JMH |
53 | pci_free_consistent(prog->dev, prog->n_pages << PAGE_SHIFT, |
54 | prog->kvirt, prog->bus_addr); | |
1da177e4 LT |
55 | } |
56 | ||
57 | prog->kvirt = NULL; | |
58 | prog->dev = NULL; | |
59 | prog->n_pages = 0; | |
60 | prog->bus_addr = 0; | |
61 | } | |
62 | ||
63 | /* dma_region */ | |
64 | ||
afd6546d SR |
65 | /** |
66 | * dma_region_init - clear out all fields but do not allocate anything | |
67 | */ | |
1da177e4 LT |
68 | void dma_region_init(struct dma_region *dma) |
69 | { | |
70 | dma->kvirt = NULL; | |
71 | dma->dev = NULL; | |
72 | dma->n_pages = 0; | |
73 | dma->n_dma_pages = 0; | |
74 | dma->sglist = NULL; | |
75 | } | |
76 | ||
afd6546d SR |
77 | /** |
78 | * dma_region_alloc - allocate the buffer and map it to the IOMMU | |
79 | */ | |
6649e92d JMH |
80 | int dma_region_alloc(struct dma_region *dma, unsigned long n_bytes, |
81 | struct pci_dev *dev, int direction) | |
1da177e4 LT |
82 | { |
83 | unsigned int i; | |
84 | ||
85 | /* round up to page size */ | |
86 | n_bytes = PAGE_ALIGN(n_bytes); | |
87 | ||
88 | dma->n_pages = n_bytes >> PAGE_SHIFT; | |
89 | ||
90 | dma->kvirt = vmalloc_32(n_bytes); | |
91 | if (!dma->kvirt) { | |
92 | printk(KERN_ERR "dma_region_alloc: vmalloc_32() failed\n"); | |
93 | goto err; | |
94 | } | |
95 | ||
96 | /* Clear the ram out, no junk to the user */ | |
97 | memset(dma->kvirt, 0, n_bytes); | |
98 | ||
99 | /* allocate scatter/gather list */ | |
100 | dma->sglist = vmalloc(dma->n_pages * sizeof(*dma->sglist)); | |
101 | if (!dma->sglist) { | |
102 | printk(KERN_ERR "dma_region_alloc: vmalloc(sglist) failed\n"); | |
103 | goto err; | |
104 | } | |
105 | ||
106 | /* just to be safe - this will become unnecessary once sglist->address goes away */ | |
107 | memset(dma->sglist, 0, dma->n_pages * sizeof(*dma->sglist)); | |
108 | ||
109 | /* fill scatter/gather list with pages */ | |
110 | for (i = 0; i < dma->n_pages; i++) { | |
6649e92d JMH |
111 | unsigned long va = |
112 | (unsigned long)dma->kvirt + (i << PAGE_SHIFT); | |
1da177e4 LT |
113 | |
114 | dma->sglist[i].page = vmalloc_to_page((void *)va); | |
115 | dma->sglist[i].length = PAGE_SIZE; | |
116 | } | |
117 | ||
118 | /* map sglist to the IOMMU */ | |
6649e92d JMH |
119 | dma->n_dma_pages = |
120 | pci_map_sg(dev, dma->sglist, dma->n_pages, direction); | |
1da177e4 LT |
121 | |
122 | if (dma->n_dma_pages == 0) { | |
123 | printk(KERN_ERR "dma_region_alloc: pci_map_sg() failed\n"); | |
124 | goto err; | |
125 | } | |
126 | ||
127 | dma->dev = dev; | |
128 | dma->direction = direction; | |
129 | ||
130 | return 0; | |
131 | ||
6649e92d | 132 | err: |
1da177e4 LT |
133 | dma_region_free(dma); |
134 | return -ENOMEM; | |
135 | } | |
136 | ||
afd6546d SR |
137 | /** |
138 | * dma_region_free - unmap and free the buffer | |
139 | */ | |
1da177e4 LT |
140 | void dma_region_free(struct dma_region *dma) |
141 | { | |
142 | if (dma->n_dma_pages) { | |
6649e92d JMH |
143 | pci_unmap_sg(dma->dev, dma->sglist, dma->n_pages, |
144 | dma->direction); | |
1da177e4 LT |
145 | dma->n_dma_pages = 0; |
146 | dma->dev = NULL; | |
147 | } | |
148 | ||
149 | vfree(dma->sglist); | |
150 | dma->sglist = NULL; | |
151 | ||
152 | vfree(dma->kvirt); | |
153 | dma->kvirt = NULL; | |
154 | dma->n_pages = 0; | |
155 | } | |
156 | ||
157 | /* find the scatterlist index and remaining offset corresponding to a | |
158 | given offset from the beginning of the buffer */ | |
6649e92d | 159 | static inline int dma_region_find(struct dma_region *dma, unsigned long offset, |
9bb2bcdb | 160 | unsigned int start, unsigned long *rem) |
1da177e4 LT |
161 | { |
162 | int i; | |
163 | unsigned long off = offset; | |
164 | ||
9bb2bcdb | 165 | for (i = start; i < dma->n_dma_pages; i++) { |
1da177e4 LT |
166 | if (off < sg_dma_len(&dma->sglist[i])) { |
167 | *rem = off; | |
168 | break; | |
169 | } | |
170 | ||
171 | off -= sg_dma_len(&dma->sglist[i]); | |
172 | } | |
173 | ||
174 | BUG_ON(i >= dma->n_dma_pages); | |
175 | ||
176 | return i; | |
177 | } | |
178 | ||
afd6546d SR |
179 | /** |
180 | * dma_region_offset_to_bus - get bus address of an offset within a DMA region | |
181 | * | |
182 | * Returns the DMA bus address of the byte with the given @offset relative to | |
183 | * the beginning of the @dma. | |
184 | */ | |
6649e92d JMH |
185 | dma_addr_t dma_region_offset_to_bus(struct dma_region * dma, |
186 | unsigned long offset) | |
1da177e4 | 187 | { |
1934b8b6 | 188 | unsigned long rem = 0; |
1da177e4 | 189 | |
6649e92d | 190 | struct scatterlist *sg = |
9bb2bcdb | 191 | &dma->sglist[dma_region_find(dma, offset, 0, &rem)]; |
1da177e4 LT |
192 | return sg_dma_address(sg) + rem; |
193 | } | |
194 | ||
afd6546d SR |
195 | /** |
196 | * dma_region_sync_for_cpu - sync the CPU's view of the buffer | |
197 | */ | |
6649e92d JMH |
198 | void dma_region_sync_for_cpu(struct dma_region *dma, unsigned long offset, |
199 | unsigned long len) | |
1da177e4 LT |
200 | { |
201 | int first, last; | |
9bb2bcdb | 202 | unsigned long rem = 0; |
1da177e4 LT |
203 | |
204 | if (!len) | |
205 | len = 1; | |
206 | ||
9bb2bcdb BC |
207 | first = dma_region_find(dma, offset, 0, &rem); |
208 | last = dma_region_find(dma, rem + len - 1, first, &rem); | |
1da177e4 | 209 | |
6649e92d JMH |
210 | pci_dma_sync_sg_for_cpu(dma->dev, &dma->sglist[first], last - first + 1, |
211 | dma->direction); | |
1da177e4 LT |
212 | } |
213 | ||
afd6546d SR |
214 | /** |
215 | * dma_region_sync_for_device - sync the IO bus' view of the buffer | |
216 | */ | |
6649e92d JMH |
217 | void dma_region_sync_for_device(struct dma_region *dma, unsigned long offset, |
218 | unsigned long len) | |
1da177e4 LT |
219 | { |
220 | int first, last; | |
9bb2bcdb | 221 | unsigned long rem = 0; |
1da177e4 LT |
222 | |
223 | if (!len) | |
224 | len = 1; | |
225 | ||
9bb2bcdb BC |
226 | first = dma_region_find(dma, offset, 0, &rem); |
227 | last = dma_region_find(dma, rem + len - 1, first, &rem); | |
1da177e4 | 228 | |
6649e92d JMH |
229 | pci_dma_sync_sg_for_device(dma->dev, &dma->sglist[first], |
230 | last - first + 1, dma->direction); | |
1da177e4 LT |
231 | } |
232 | ||
233 | #ifdef CONFIG_MMU | |
234 | ||
235 | /* nopage() handler for mmap access */ | |
236 | ||
6649e92d JMH |
237 | static struct page *dma_region_pagefault(struct vm_area_struct *area, |
238 | unsigned long address, int *type) | |
1da177e4 LT |
239 | { |
240 | unsigned long offset; | |
241 | unsigned long kernel_virt_addr; | |
242 | struct page *ret = NOPAGE_SIGBUS; | |
243 | ||
6649e92d | 244 | struct dma_region *dma = (struct dma_region *)area->vm_private_data; |
1da177e4 LT |
245 | |
246 | if (!dma->kvirt) | |
247 | goto out; | |
248 | ||
6649e92d JMH |
249 | if ((address < (unsigned long)area->vm_start) || |
250 | (address > | |
251 | (unsigned long)area->vm_start + (dma->n_pages << PAGE_SHIFT))) | |
1da177e4 LT |
252 | goto out; |
253 | ||
254 | if (type) | |
255 | *type = VM_FAULT_MINOR; | |
256 | offset = address - area->vm_start; | |
6649e92d JMH |
257 | kernel_virt_addr = (unsigned long)dma->kvirt + offset; |
258 | ret = vmalloc_to_page((void *)kernel_virt_addr); | |
1da177e4 | 259 | get_page(ret); |
6649e92d | 260 | out: |
1da177e4 LT |
261 | return ret; |
262 | } | |
263 | ||
264 | static struct vm_operations_struct dma_region_vm_ops = { | |
6649e92d | 265 | .nopage = dma_region_pagefault, |
1da177e4 LT |
266 | }; |
267 | ||
afd6546d SR |
268 | /** |
269 | * dma_region_mmap - map the buffer into a user space process | |
270 | */ | |
6649e92d JMH |
271 | int dma_region_mmap(struct dma_region *dma, struct file *file, |
272 | struct vm_area_struct *vma) | |
1da177e4 LT |
273 | { |
274 | unsigned long size; | |
275 | ||
276 | if (!dma->kvirt) | |
277 | return -EINVAL; | |
278 | ||
279 | /* must be page-aligned */ | |
280 | if (vma->vm_pgoff != 0) | |
281 | return -EINVAL; | |
282 | ||
283 | /* check the length */ | |
284 | size = vma->vm_end - vma->vm_start; | |
285 | if (size > (dma->n_pages << PAGE_SHIFT)) | |
286 | return -EINVAL; | |
287 | ||
288 | vma->vm_ops = &dma_region_vm_ops; | |
289 | vma->vm_private_data = dma; | |
290 | vma->vm_file = file; | |
291 | vma->vm_flags |= VM_RESERVED; | |
292 | ||
293 | return 0; | |
294 | } | |
295 | ||
6649e92d | 296 | #else /* CONFIG_MMU */ |
1da177e4 | 297 | |
6649e92d JMH |
298 | int dma_region_mmap(struct dma_region *dma, struct file *file, |
299 | struct vm_area_struct *vma) | |
1da177e4 LT |
300 | { |
301 | return -EINVAL; | |
302 | } | |
303 | ||
6649e92d | 304 | #endif /* CONFIG_MMU */ |