[PATCH] USB: CREDITS: Add credits about the ZC0301 and ET61X[12]51 USB drivers
[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/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
18 void 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
26 int dma_prog_region_alloc(struct dma_prog_region *prog, unsigned long n_bytes,
27                           struct pci_dev *dev)
28 {
29         /* round up to page size */
30         n_bytes = PAGE_ALIGN(n_bytes);
31
32         prog->n_pages = n_bytes >> PAGE_SHIFT;
33
34         prog->kvirt = pci_alloc_consistent(dev, n_bytes, &prog->bus_addr);
35         if (!prog->kvirt) {
36                 printk(KERN_ERR
37                        "dma_prog_region_alloc: pci_alloc_consistent() failed\n");
38                 dma_prog_region_free(prog);
39                 return -ENOMEM;
40         }
41
42         prog->dev = dev;
43
44         return 0;
45 }
46
47 void dma_prog_region_free(struct dma_prog_region *prog)
48 {
49         if (prog->kvirt) {
50                 pci_free_consistent(prog->dev, prog->n_pages << PAGE_SHIFT,
51                                     prog->kvirt, prog->bus_addr);
52         }
53
54         prog->kvirt = NULL;
55         prog->dev = NULL;
56         prog->n_pages = 0;
57         prog->bus_addr = 0;
58 }
59
60 /* dma_region */
61
62 void dma_region_init(struct dma_region *dma)
63 {
64         dma->kvirt = NULL;
65         dma->dev = NULL;
66         dma->n_pages = 0;
67         dma->n_dma_pages = 0;
68         dma->sglist = NULL;
69 }
70
71 int dma_region_alloc(struct dma_region *dma, unsigned long n_bytes,
72                      struct pci_dev *dev, int direction)
73 {
74         unsigned int i;
75
76         /* round up to page size */
77         n_bytes = PAGE_ALIGN(n_bytes);
78
79         dma->n_pages = n_bytes >> PAGE_SHIFT;
80
81         dma->kvirt = vmalloc_32(n_bytes);
82         if (!dma->kvirt) {
83                 printk(KERN_ERR "dma_region_alloc: vmalloc_32() failed\n");
84                 goto err;
85         }
86
87         /* Clear the ram out, no junk to the user */
88         memset(dma->kvirt, 0, n_bytes);
89
90         /* allocate scatter/gather list */
91         dma->sglist = vmalloc(dma->n_pages * sizeof(*dma->sglist));
92         if (!dma->sglist) {
93                 printk(KERN_ERR "dma_region_alloc: vmalloc(sglist) failed\n");
94                 goto err;
95         }
96
97         /* just to be safe - this will become unnecessary once sglist->address goes away */
98         memset(dma->sglist, 0, dma->n_pages * sizeof(*dma->sglist));
99
100         /* fill scatter/gather list with pages */
101         for (i = 0; i < dma->n_pages; i++) {
102                 unsigned long va =
103                     (unsigned long)dma->kvirt + (i << PAGE_SHIFT);
104
105                 dma->sglist[i].page = vmalloc_to_page((void *)va);
106                 dma->sglist[i].length = PAGE_SIZE;
107         }
108
109         /* map sglist to the IOMMU */
110         dma->n_dma_pages =
111             pci_map_sg(dev, dma->sglist, dma->n_pages, direction);
112
113         if (dma->n_dma_pages == 0) {
114                 printk(KERN_ERR "dma_region_alloc: pci_map_sg() failed\n");
115                 goto err;
116         }
117
118         dma->dev = dev;
119         dma->direction = direction;
120
121         return 0;
122
123       err:
124         dma_region_free(dma);
125         return -ENOMEM;
126 }
127
128 void dma_region_free(struct dma_region *dma)
129 {
130         if (dma->n_dma_pages) {
131                 pci_unmap_sg(dma->dev, dma->sglist, dma->n_pages,
132                              dma->direction);
133                 dma->n_dma_pages = 0;
134                 dma->dev = NULL;
135         }
136
137         vfree(dma->sglist);
138         dma->sglist = NULL;
139
140         vfree(dma->kvirt);
141         dma->kvirt = NULL;
142         dma->n_pages = 0;
143 }
144
145 /* find the scatterlist index and remaining offset corresponding to a
146    given offset from the beginning of the buffer */
147 static inline int dma_region_find(struct dma_region *dma, unsigned long offset,
148                                   unsigned long *rem)
149 {
150         int i;
151         unsigned long off = offset;
152
153         for (i = 0; i < dma->n_dma_pages; i++) {
154                 if (off < sg_dma_len(&dma->sglist[i])) {
155                         *rem = off;
156                         break;
157                 }
158
159                 off -= sg_dma_len(&dma->sglist[i]);
160         }
161
162         BUG_ON(i >= dma->n_dma_pages);
163
164         return i;
165 }
166
167 dma_addr_t dma_region_offset_to_bus(struct dma_region * dma,
168                                     unsigned long offset)
169 {
170         unsigned long rem = 0;
171
172         struct scatterlist *sg =
173             &dma->sglist[dma_region_find(dma, offset, &rem)];
174         return sg_dma_address(sg) + rem;
175 }
176
177 void dma_region_sync_for_cpu(struct dma_region *dma, unsigned long offset,
178                              unsigned long len)
179 {
180         int first, last;
181         unsigned long rem;
182
183         if (!len)
184                 len = 1;
185
186         first = dma_region_find(dma, offset, &rem);
187         last = dma_region_find(dma, offset + len - 1, &rem);
188
189         pci_dma_sync_sg_for_cpu(dma->dev, &dma->sglist[first], last - first + 1,
190                                 dma->direction);
191 }
192
193 void dma_region_sync_for_device(struct dma_region *dma, unsigned long offset,
194                                 unsigned long len)
195 {
196         int first, last;
197         unsigned long rem;
198
199         if (!len)
200                 len = 1;
201
202         first = dma_region_find(dma, offset, &rem);
203         last = dma_region_find(dma, offset + len - 1, &rem);
204
205         pci_dma_sync_sg_for_device(dma->dev, &dma->sglist[first],
206                                    last - first + 1, dma->direction);
207 }
208
209 #ifdef CONFIG_MMU
210
211 /* nopage() handler for mmap access */
212
213 static struct page *dma_region_pagefault(struct vm_area_struct *area,
214                                          unsigned long address, int *type)
215 {
216         unsigned long offset;
217         unsigned long kernel_virt_addr;
218         struct page *ret = NOPAGE_SIGBUS;
219
220         struct dma_region *dma = (struct dma_region *)area->vm_private_data;
221
222         if (!dma->kvirt)
223                 goto out;
224
225         if ((address < (unsigned long)area->vm_start) ||
226             (address >
227              (unsigned long)area->vm_start + (dma->n_pages << PAGE_SHIFT)))
228                 goto out;
229
230         if (type)
231                 *type = VM_FAULT_MINOR;
232         offset = address - area->vm_start;
233         kernel_virt_addr = (unsigned long)dma->kvirt + offset;
234         ret = vmalloc_to_page((void *)kernel_virt_addr);
235         get_page(ret);
236       out:
237         return ret;
238 }
239
240 static struct vm_operations_struct dma_region_vm_ops = {
241         .nopage = dma_region_pagefault,
242 };
243
244 int dma_region_mmap(struct dma_region *dma, struct file *file,
245                     struct vm_area_struct *vma)
246 {
247         unsigned long size;
248
249         if (!dma->kvirt)
250                 return -EINVAL;
251
252         /* must be page-aligned */
253         if (vma->vm_pgoff != 0)
254                 return -EINVAL;
255
256         /* check the length */
257         size = vma->vm_end - vma->vm_start;
258         if (size > (dma->n_pages << PAGE_SHIFT))
259                 return -EINVAL;
260
261         vma->vm_ops = &dma_region_vm_ops;
262         vma->vm_private_data = dma;
263         vma->vm_file = file;
264         vma->vm_flags |= VM_RESERVED;
265
266         return 0;
267 }
268
269 #else                           /* CONFIG_MMU */
270
271 int dma_region_mmap(struct dma_region *dma, struct file *file,
272                     struct vm_area_struct *vma)
273 {
274         return -EINVAL;
275 }
276
277 #endif                          /* CONFIG_MMU */