remove the broken SKMC driver
[linux-2.6] / 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/slab.h>
14 #include <linux/vmalloc.h>
15 #include <asm/scatterlist.h>
16
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
29 int dma_prog_region_alloc(struct dma_prog_region *prog, unsigned long n_bytes,
30                           struct pci_dev *dev)
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) {
39                 printk(KERN_ERR
40                        "dma_prog_region_alloc: pci_alloc_consistent() failed\n");
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) {
53                 pci_free_consistent(prog->dev, prog->n_pages << PAGE_SHIFT,
54                                     prog->kvirt, prog->bus_addr);
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
65 void dma_region_init(struct dma_region *dma)
66 {
67         dma->kvirt = NULL;
68         dma->dev = NULL;
69         dma->n_pages = 0;
70         dma->n_dma_pages = 0;
71         dma->sglist = NULL;
72 }
73
74 int dma_region_alloc(struct dma_region *dma, unsigned long n_bytes,
75                      struct pci_dev *dev, int direction)
76 {
77         unsigned int i;
78
79         /* round up to page size */
80         n_bytes = PAGE_ALIGN(n_bytes);
81
82         dma->n_pages = n_bytes >> PAGE_SHIFT;
83
84         dma->kvirt = vmalloc_32(n_bytes);
85         if (!dma->kvirt) {
86                 printk(KERN_ERR "dma_region_alloc: vmalloc_32() failed\n");
87                 goto err;
88         }
89
90         /* Clear the ram out, no junk to the user */
91         memset(dma->kvirt, 0, n_bytes);
92
93         /* allocate scatter/gather list */
94         dma->sglist = vmalloc(dma->n_pages * sizeof(*dma->sglist));
95         if (!dma->sglist) {
96                 printk(KERN_ERR "dma_region_alloc: vmalloc(sglist) failed\n");
97                 goto err;
98         }
99
100         /* just to be safe - this will become unnecessary once sglist->address goes away */
101         memset(dma->sglist, 0, dma->n_pages * sizeof(*dma->sglist));
102
103         /* fill scatter/gather list with pages */
104         for (i = 0; i < dma->n_pages; i++) {
105                 unsigned long va =
106                     (unsigned long)dma->kvirt + (i << PAGE_SHIFT);
107
108                 dma->sglist[i].page = vmalloc_to_page((void *)va);
109                 dma->sglist[i].length = PAGE_SIZE;
110         }
111
112         /* map sglist to the IOMMU */
113         dma->n_dma_pages =
114             pci_map_sg(dev, dma->sglist, dma->n_pages, direction);
115
116         if (dma->n_dma_pages == 0) {
117                 printk(KERN_ERR "dma_region_alloc: pci_map_sg() failed\n");
118                 goto err;
119         }
120
121         dma->dev = dev;
122         dma->direction = direction;
123
124         return 0;
125
126       err:
127         dma_region_free(dma);
128         return -ENOMEM;
129 }
130
131 void dma_region_free(struct dma_region *dma)
132 {
133         if (dma->n_dma_pages) {
134                 pci_unmap_sg(dma->dev, dma->sglist, dma->n_pages,
135                              dma->direction);
136                 dma->n_dma_pages = 0;
137                 dma->dev = NULL;
138         }
139
140         vfree(dma->sglist);
141         dma->sglist = NULL;
142
143         vfree(dma->kvirt);
144         dma->kvirt = NULL;
145         dma->n_pages = 0;
146 }
147
148 /* find the scatterlist index and remaining offset corresponding to a
149    given offset from the beginning of the buffer */
150 static inline int dma_region_find(struct dma_region *dma, unsigned long offset,
151                                   unsigned int start, unsigned long *rem)
152 {
153         int i;
154         unsigned long off = offset;
155
156         for (i = start; i < dma->n_dma_pages; i++) {
157                 if (off < sg_dma_len(&dma->sglist[i])) {
158                         *rem = off;
159                         break;
160                 }
161
162                 off -= sg_dma_len(&dma->sglist[i]);
163         }
164
165         BUG_ON(i >= dma->n_dma_pages);
166
167         return i;
168 }
169
170 dma_addr_t dma_region_offset_to_bus(struct dma_region * dma,
171                                     unsigned long offset)
172 {
173         unsigned long rem = 0;
174
175         struct scatterlist *sg =
176             &dma->sglist[dma_region_find(dma, offset, 0, &rem)];
177         return sg_dma_address(sg) + rem;
178 }
179
180 void dma_region_sync_for_cpu(struct dma_region *dma, unsigned long offset,
181                              unsigned long len)
182 {
183         int first, last;
184         unsigned long rem = 0;
185
186         if (!len)
187                 len = 1;
188
189         first = dma_region_find(dma, offset, 0, &rem);
190         last = dma_region_find(dma, rem + len - 1, first, &rem);
191
192         pci_dma_sync_sg_for_cpu(dma->dev, &dma->sglist[first], last - first + 1,
193                                 dma->direction);
194 }
195
196 void dma_region_sync_for_device(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_device(dma->dev, &dma->sglist[first],
209                                    last - first + 1, dma->direction);
210 }
211
212 #ifdef CONFIG_MMU
213
214 /* nopage() handler for mmap access */
215
216 static struct page *dma_region_pagefault(struct vm_area_struct *area,
217                                          unsigned long address, int *type)
218 {
219         unsigned long offset;
220         unsigned long kernel_virt_addr;
221         struct page *ret = NOPAGE_SIGBUS;
222
223         struct dma_region *dma = (struct dma_region *)area->vm_private_data;
224
225         if (!dma->kvirt)
226                 goto out;
227
228         if ((address < (unsigned long)area->vm_start) ||
229             (address >
230              (unsigned long)area->vm_start + (dma->n_pages << PAGE_SHIFT)))
231                 goto out;
232
233         if (type)
234                 *type = VM_FAULT_MINOR;
235         offset = address - area->vm_start;
236         kernel_virt_addr = (unsigned long)dma->kvirt + offset;
237         ret = vmalloc_to_page((void *)kernel_virt_addr);
238         get_page(ret);
239       out:
240         return ret;
241 }
242
243 static struct vm_operations_struct dma_region_vm_ops = {
244         .nopage = dma_region_pagefault,
245 };
246
247 int dma_region_mmap(struct dma_region *dma, struct file *file,
248                     struct vm_area_struct *vma)
249 {
250         unsigned long size;
251
252         if (!dma->kvirt)
253                 return -EINVAL;
254
255         /* must be page-aligned */
256         if (vma->vm_pgoff != 0)
257                 return -EINVAL;
258
259         /* check the length */
260         size = vma->vm_end - vma->vm_start;
261         if (size > (dma->n_pages << PAGE_SHIFT))
262                 return -EINVAL;
263
264         vma->vm_ops = &dma_region_vm_ops;
265         vma->vm_private_data = dma;
266         vma->vm_file = file;
267         vma->vm_flags |= VM_RESERVED;
268
269         return 0;
270 }
271
272 #else                           /* CONFIG_MMU */
273
274 int dma_region_mmap(struct dma_region *dma, struct file *file,
275                     struct vm_area_struct *vma)
276 {
277         return -EINVAL;
278 }
279
280 #endif                          /* CONFIG_MMU */