Commit | Line | Data |
---|---|---|
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 | 14 | #include <linux/vmalloc.h> |
11763609 | 15 | #include <linux/scatterlist.h> |
de4394f1 | 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 | ||
9e66269d | 106 | sg_init_table(dma->sglist, dma->n_pages); |
1da177e4 LT |
107 | |
108 | /* fill scatter/gather list with pages */ | |
109 | for (i = 0; i < dma->n_pages; i++) { | |
6649e92d JMH |
110 | unsigned long va = |
111 | (unsigned long)dma->kvirt + (i << PAGE_SHIFT); | |
1da177e4 | 112 | |
642f1490 JA |
113 | sg_set_page(&dma->sglist[i], vmalloc_to_page((void *)va), |
114 | PAGE_SIZE, 0); | |
1da177e4 LT |
115 | } |
116 | ||
117 | /* map sglist to the IOMMU */ | |
6649e92d JMH |
118 | dma->n_dma_pages = |
119 | pci_map_sg(dev, dma->sglist, dma->n_pages, direction); | |
1da177e4 LT |
120 | |
121 | if (dma->n_dma_pages == 0) { | |
122 | printk(KERN_ERR "dma_region_alloc: pci_map_sg() failed\n"); | |
123 | goto err; | |
124 | } | |
125 | ||
126 | dma->dev = dev; | |
127 | dma->direction = direction; | |
128 | ||
129 | return 0; | |
130 | ||
6649e92d | 131 | err: |
1da177e4 LT |
132 | dma_region_free(dma); |
133 | return -ENOMEM; | |
134 | } | |
135 | ||
afd6546d SR |
136 | /** |
137 | * dma_region_free - unmap and free the buffer | |
138 | */ | |
1da177e4 LT |
139 | void dma_region_free(struct dma_region *dma) |
140 | { | |
141 | if (dma->n_dma_pages) { | |
6649e92d JMH |
142 | pci_unmap_sg(dma->dev, dma->sglist, dma->n_pages, |
143 | dma->direction); | |
1da177e4 LT |
144 | dma->n_dma_pages = 0; |
145 | dma->dev = NULL; | |
146 | } | |
147 | ||
148 | vfree(dma->sglist); | |
149 | dma->sglist = NULL; | |
150 | ||
151 | vfree(dma->kvirt); | |
152 | dma->kvirt = NULL; | |
153 | dma->n_pages = 0; | |
154 | } | |
155 | ||
156 | /* find the scatterlist index and remaining offset corresponding to a | |
157 | given offset from the beginning of the buffer */ | |
6649e92d | 158 | static inline int dma_region_find(struct dma_region *dma, unsigned long offset, |
9bb2bcdb | 159 | unsigned int start, unsigned long *rem) |
1da177e4 LT |
160 | { |
161 | int i; | |
162 | unsigned long off = offset; | |
163 | ||
9bb2bcdb | 164 | for (i = start; i < dma->n_dma_pages; i++) { |
1da177e4 LT |
165 | if (off < sg_dma_len(&dma->sglist[i])) { |
166 | *rem = off; | |
167 | break; | |
168 | } | |
169 | ||
170 | off -= sg_dma_len(&dma->sglist[i]); | |
171 | } | |
172 | ||
173 | BUG_ON(i >= dma->n_dma_pages); | |
174 | ||
175 | return i; | |
176 | } | |
177 | ||
afd6546d SR |
178 | /** |
179 | * dma_region_offset_to_bus - get bus address of an offset within a DMA region | |
180 | * | |
181 | * Returns the DMA bus address of the byte with the given @offset relative to | |
182 | * the beginning of the @dma. | |
183 | */ | |
6649e92d JMH |
184 | dma_addr_t dma_region_offset_to_bus(struct dma_region * dma, |
185 | unsigned long offset) | |
1da177e4 | 186 | { |
1934b8b6 | 187 | unsigned long rem = 0; |
1da177e4 | 188 | |
6649e92d | 189 | struct scatterlist *sg = |
9bb2bcdb | 190 | &dma->sglist[dma_region_find(dma, offset, 0, &rem)]; |
1da177e4 LT |
191 | return sg_dma_address(sg) + rem; |
192 | } | |
193 | ||
afd6546d SR |
194 | /** |
195 | * dma_region_sync_for_cpu - sync the CPU's view of the buffer | |
196 | */ | |
6649e92d JMH |
197 | void dma_region_sync_for_cpu(struct dma_region *dma, unsigned long offset, |
198 | unsigned long len) | |
1da177e4 LT |
199 | { |
200 | int first, last; | |
9bb2bcdb | 201 | unsigned long rem = 0; |
1da177e4 LT |
202 | |
203 | if (!len) | |
204 | len = 1; | |
205 | ||
9bb2bcdb BC |
206 | first = dma_region_find(dma, offset, 0, &rem); |
207 | last = dma_region_find(dma, rem + len - 1, first, &rem); | |
1da177e4 | 208 | |
6649e92d JMH |
209 | pci_dma_sync_sg_for_cpu(dma->dev, &dma->sglist[first], last - first + 1, |
210 | dma->direction); | |
1da177e4 LT |
211 | } |
212 | ||
afd6546d SR |
213 | /** |
214 | * dma_region_sync_for_device - sync the IO bus' view of the buffer | |
215 | */ | |
6649e92d JMH |
216 | void dma_region_sync_for_device(struct dma_region *dma, unsigned long offset, |
217 | unsigned long len) | |
1da177e4 LT |
218 | { |
219 | int first, last; | |
9bb2bcdb | 220 | unsigned long rem = 0; |
1da177e4 LT |
221 | |
222 | if (!len) | |
223 | len = 1; | |
224 | ||
9bb2bcdb BC |
225 | first = dma_region_find(dma, offset, 0, &rem); |
226 | last = dma_region_find(dma, rem + len - 1, first, &rem); | |
1da177e4 | 227 | |
6649e92d JMH |
228 | pci_dma_sync_sg_for_device(dma->dev, &dma->sglist[first], |
229 | last - first + 1, dma->direction); | |
1da177e4 LT |
230 | } |
231 | ||
232 | #ifdef CONFIG_MMU | |
233 | ||
61db8121 | 234 | static int dma_region_pagefault(struct vm_area_struct *vma, |
c7ea990f | 235 | struct vm_fault *vmf) |
1da177e4 | 236 | { |
61db8121 | 237 | struct dma_region *dma = (struct dma_region *)vma->vm_private_data; |
1da177e4 LT |
238 | |
239 | if (!dma->kvirt) | |
c7ea990f | 240 | return VM_FAULT_SIGBUS; |
61db8121 NP |
241 | |
242 | if (vmf->pgoff >= dma->n_pages) | |
c7ea990f | 243 | return VM_FAULT_SIGBUS; |
61db8121 | 244 | |
c7ea990f | 245 | vmf->page = vmalloc_to_page(dma->kvirt + (vmf->pgoff << PAGE_SHIFT)); |
61db8121 NP |
246 | get_page(vmf->page); |
247 | return 0; | |
1da177e4 LT |
248 | } |
249 | ||
250 | static struct vm_operations_struct dma_region_vm_ops = { | |
61db8121 | 251 | .fault = dma_region_pagefault, |
1da177e4 LT |
252 | }; |
253 | ||
afd6546d SR |
254 | /** |
255 | * dma_region_mmap - map the buffer into a user space process | |
256 | */ | |
6649e92d JMH |
257 | int dma_region_mmap(struct dma_region *dma, struct file *file, |
258 | struct vm_area_struct *vma) | |
1da177e4 LT |
259 | { |
260 | unsigned long size; | |
261 | ||
262 | if (!dma->kvirt) | |
263 | return -EINVAL; | |
264 | ||
61db8121 | 265 | /* must be page-aligned (XXX: comment is wrong, we could allow pgoff) */ |
1da177e4 LT |
266 | if (vma->vm_pgoff != 0) |
267 | return -EINVAL; | |
268 | ||
269 | /* check the length */ | |
270 | size = vma->vm_end - vma->vm_start; | |
271 | if (size > (dma->n_pages << PAGE_SHIFT)) | |
272 | return -EINVAL; | |
273 | ||
274 | vma->vm_ops = &dma_region_vm_ops; | |
275 | vma->vm_private_data = dma; | |
276 | vma->vm_file = file; | |
435f9726 | 277 | vma->vm_flags |= VM_RESERVED | VM_ALWAYSDUMP; |
1da177e4 LT |
278 | |
279 | return 0; | |
280 | } | |
281 | ||
6649e92d | 282 | #else /* CONFIG_MMU */ |
1da177e4 | 283 | |
6649e92d JMH |
284 | int dma_region_mmap(struct dma_region *dma, struct file *file, |
285 | struct vm_area_struct *vma) | |
1da177e4 LT |
286 | { |
287 | return -EINVAL; | |
288 | } | |
289 | ||
6649e92d | 290 | #endif /* CONFIG_MMU */ |