include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit...
[linux-2.6.git] / drivers / ieee1394 / dma.c
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/mm.h>
11 #include <linux/module.h>
12 #include <linux/pci.h>
13 #include <linux/vmalloc.h>
14 #include <linux/scatterlist.h>
15
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
28 int dma_prog_region_alloc(struct dma_prog_region *prog, unsigned long n_bytes,
29                           struct pci_dev *dev)
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) {
38                 printk(KERN_ERR
39                        "dma_prog_region_alloc: pci_alloc_consistent() failed\n");
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) {
52                 pci_free_consistent(prog->dev, prog->n_pages << PAGE_SHIFT,
53                                     prog->kvirt, prog->bus_addr);
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
64 /**
65  * dma_region_init - clear out all fields but do not allocate anything
66  */
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
76 /**
77  * dma_region_alloc - allocate the buffer and map it to the IOMMU
78  */
79 int dma_region_alloc(struct dma_region *dma, unsigned long n_bytes,
80                      struct pci_dev *dev, int direction)
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
105         sg_init_table(dma->sglist, dma->n_pages);
106
107         /* fill scatter/gather list with pages */
108         for (i = 0; i < dma->n_pages; i++) {
109                 unsigned long va =
110                     (unsigned long)dma->kvirt + (i << PAGE_SHIFT);
111
112                 sg_set_page(&dma->sglist[i], vmalloc_to_page((void *)va),
113                                 PAGE_SIZE, 0);
114         }
115
116         /* map sglist to the IOMMU */
117         dma->n_dma_pages =
118             pci_map_sg(dev, dma->sglist, dma->n_pages, direction);
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
130       err:
131         dma_region_free(dma);
132         return -ENOMEM;
133 }
134
135 /**
136  * dma_region_free - unmap and free the buffer
137  */
138 void dma_region_free(struct dma_region *dma)
139 {
140         if (dma->n_dma_pages) {
141                 pci_unmap_sg(dma->dev, dma->sglist, dma->n_pages,
142                              dma->direction);
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 */
157 static inline int dma_region_find(struct dma_region *dma, unsigned long offset,
158                                   unsigned int start, unsigned long *rem)
159 {
160         int i;
161         unsigned long off = offset;
162
163         for (i = start; i < dma->n_dma_pages; i++) {
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
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  */
183 dma_addr_t dma_region_offset_to_bus(struct dma_region * dma,
184                                     unsigned long offset)
185 {
186         unsigned long rem = 0;
187
188         struct scatterlist *sg =
189             &dma->sglist[dma_region_find(dma, offset, 0, &rem)];
190         return sg_dma_address(sg) + rem;
191 }
192
193 /**
194  * dma_region_sync_for_cpu - sync the CPU's view of the buffer
195  */
196 void dma_region_sync_for_cpu(struct dma_region *dma, unsigned long offset,
197                              unsigned long len)
198 {
199         int first, last;
200         unsigned long rem = 0;
201
202         if (!len)
203                 len = 1;
204
205         first = dma_region_find(dma, offset, 0, &rem);
206         last = dma_region_find(dma, rem + len - 1, first, &rem);
207
208         pci_dma_sync_sg_for_cpu(dma->dev, &dma->sglist[first], last - first + 1,
209                                 dma->direction);
210 }
211
212 /**
213  * dma_region_sync_for_device - sync the IO bus' view of the buffer
214  */
215 void dma_region_sync_for_device(struct dma_region *dma, unsigned long offset,
216                                 unsigned long len)
217 {
218         int first, last;
219         unsigned long rem = 0;
220
221         if (!len)
222                 len = 1;
223
224         first = dma_region_find(dma, offset, 0, &rem);
225         last = dma_region_find(dma, rem + len - 1, first, &rem);
226
227         pci_dma_sync_sg_for_device(dma->dev, &dma->sglist[first],
228                                    last - first + 1, dma->direction);
229 }
230
231 #ifdef CONFIG_MMU
232
233 static int dma_region_pagefault(struct vm_area_struct *vma,
234                                 struct vm_fault *vmf)
235 {
236         struct dma_region *dma = (struct dma_region *)vma->vm_private_data;
237
238         if (!dma->kvirt)
239                 return VM_FAULT_SIGBUS;
240
241         if (vmf->pgoff >= dma->n_pages)
242                 return VM_FAULT_SIGBUS;
243
244         vmf->page = vmalloc_to_page(dma->kvirt + (vmf->pgoff << PAGE_SHIFT));
245         get_page(vmf->page);
246         return 0;
247 }
248
249 static const struct vm_operations_struct dma_region_vm_ops = {
250         .fault = dma_region_pagefault,
251 };
252
253 /**
254  * dma_region_mmap - map the buffer into a user space process
255  */
256 int dma_region_mmap(struct dma_region *dma, struct file *file,
257                     struct vm_area_struct *vma)
258 {
259         unsigned long size;
260
261         if (!dma->kvirt)
262                 return -EINVAL;
263
264         /* must be page-aligned (XXX: comment is wrong, we could allow pgoff) */
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;
276         vma->vm_flags |= VM_RESERVED | VM_ALWAYSDUMP;
277
278         return 0;
279 }
280
281 #else                           /* CONFIG_MMU */
282
283 int dma_region_mmap(struct dma_region *dma, struct file *file,
284                     struct vm_area_struct *vma)
285 {
286         return -EINVAL;
287 }
288
289 #endif                          /* CONFIG_MMU */