Merge git://git.linux-xtensa.org/kernel/xtensa-feed
[linux-2.6] / drivers / char / drm / drm_scatter.c
1 /**
2  * \file drm_scatter.c
3  * IOCTLs to manage scatter/gather memory
4  *
5  * \author Gareth Hughes <gareth@valinux.com>
6  */
7
8 /*
9  * Created: Mon Dec 18 23:20:54 2000 by gareth@valinux.com
10  *
11  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
12  * All Rights Reserved.
13  *
14  * Permission is hereby granted, free of charge, to any person obtaining a
15  * copy of this software and associated documentation files (the "Software"),
16  * to deal in the Software without restriction, including without limitation
17  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
18  * and/or sell copies of the Software, and to permit persons to whom the
19  * Software is furnished to do so, subject to the following conditions:
20  *
21  * The above copyright notice and this permission notice (including the next
22  * paragraph) shall be included in all copies or substantial portions of the
23  * Software.
24  *
25  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
26  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
27  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
28  * PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
29  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
30  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
31  * DEALINGS IN THE SOFTWARE.
32  */
33
34 #include <linux/vmalloc.h>
35 #include "drmP.h"
36
37 #define DEBUG_SCATTER 0
38
39 void drm_sg_cleanup(drm_sg_mem_t * entry)
40 {
41         struct page *page;
42         int i;
43
44         for (i = 0; i < entry->pages; i++) {
45                 page = entry->pagelist[i];
46                 if (page)
47                         ClearPageReserved(page);
48         }
49
50         vfree(entry->virtual);
51
52         drm_free(entry->busaddr,
53                  entry->pages * sizeof(*entry->busaddr), DRM_MEM_PAGES);
54         drm_free(entry->pagelist,
55                  entry->pages * sizeof(*entry->pagelist), DRM_MEM_PAGES);
56         drm_free(entry, sizeof(*entry), DRM_MEM_SGLISTS);
57 }
58
59 #ifdef _LP64
60 # define ScatterHandle(x) (unsigned int)((x >> 32) + (x & ((1L << 32) - 1)))
61 #else
62 # define ScatterHandle(x) (unsigned int)(x)
63 #endif
64
65 int drm_sg_alloc(struct inode *inode, struct file *filp,
66                  unsigned int cmd, unsigned long arg)
67 {
68         drm_file_t *priv = filp->private_data;
69         drm_device_t *dev = priv->head->dev;
70         drm_scatter_gather_t __user *argp = (void __user *)arg;
71         drm_scatter_gather_t request;
72         drm_sg_mem_t *entry;
73         unsigned long pages, i, j;
74
75         DRM_DEBUG("%s\n", __FUNCTION__);
76
77         if (!drm_core_check_feature(dev, DRIVER_SG))
78                 return -EINVAL;
79
80         if (dev->sg)
81                 return -EINVAL;
82
83         if (copy_from_user(&request, argp, sizeof(request)))
84                 return -EFAULT;
85
86         entry = drm_alloc(sizeof(*entry), DRM_MEM_SGLISTS);
87         if (!entry)
88                 return -ENOMEM;
89
90         memset(entry, 0, sizeof(*entry));
91
92         pages = (request.size + PAGE_SIZE - 1) / PAGE_SIZE;
93         DRM_DEBUG("sg size=%ld pages=%ld\n", request.size, pages);
94
95         entry->pages = pages;
96         entry->pagelist = drm_alloc(pages * sizeof(*entry->pagelist),
97                                     DRM_MEM_PAGES);
98         if (!entry->pagelist) {
99                 drm_free(entry, sizeof(*entry), DRM_MEM_SGLISTS);
100                 return -ENOMEM;
101         }
102
103         memset(entry->pagelist, 0, pages * sizeof(*entry->pagelist));
104
105         entry->busaddr = drm_alloc(pages * sizeof(*entry->busaddr),
106                                    DRM_MEM_PAGES);
107         if (!entry->busaddr) {
108                 drm_free(entry->pagelist,
109                          entry->pages * sizeof(*entry->pagelist),
110                          DRM_MEM_PAGES);
111                 drm_free(entry, sizeof(*entry), DRM_MEM_SGLISTS);
112                 return -ENOMEM;
113         }
114         memset((void *)entry->busaddr, 0, pages * sizeof(*entry->busaddr));
115
116         entry->virtual = vmalloc_32(pages << PAGE_SHIFT);
117         if (!entry->virtual) {
118                 drm_free(entry->busaddr,
119                          entry->pages * sizeof(*entry->busaddr), DRM_MEM_PAGES);
120                 drm_free(entry->pagelist,
121                          entry->pages * sizeof(*entry->pagelist),
122                          DRM_MEM_PAGES);
123                 drm_free(entry, sizeof(*entry), DRM_MEM_SGLISTS);
124                 return -ENOMEM;
125         }
126
127         /* This also forces the mapping of COW pages, so our page list
128          * will be valid.  Please don't remove it...
129          */
130         memset(entry->virtual, 0, pages << PAGE_SHIFT);
131
132         entry->handle = ScatterHandle((unsigned long)entry->virtual);
133
134         DRM_DEBUG("sg alloc handle  = %08lx\n", entry->handle);
135         DRM_DEBUG("sg alloc virtual = %p\n", entry->virtual);
136
137         for (i = (unsigned long)entry->virtual, j = 0; j < pages;
138              i += PAGE_SIZE, j++) {
139                 entry->pagelist[j] = vmalloc_to_page((void *)i);
140                 if (!entry->pagelist[j])
141                         goto failed;
142                 SetPageReserved(entry->pagelist[j]);
143         }
144
145         request.handle = entry->handle;
146
147         if (copy_to_user(argp, &request, sizeof(request))) {
148                 drm_sg_cleanup(entry);
149                 return -EFAULT;
150         }
151
152         dev->sg = entry;
153
154 #if DEBUG_SCATTER
155         /* Verify that each page points to its virtual address, and vice
156          * versa.
157          */
158         {
159                 int error = 0;
160
161                 for (i = 0; i < pages; i++) {
162                         unsigned long *tmp;
163
164                         tmp = page_address(entry->pagelist[i]);
165                         for (j = 0;
166                              j < PAGE_SIZE / sizeof(unsigned long);
167                              j++, tmp++) {
168                                 *tmp = 0xcafebabe;
169                         }
170                         tmp = (unsigned long *)((u8 *) entry->virtual +
171                                                 (PAGE_SIZE * i));
172                         for (j = 0;
173                              j < PAGE_SIZE / sizeof(unsigned long);
174                              j++, tmp++) {
175                                 if (*tmp != 0xcafebabe && error == 0) {
176                                         error = 1;
177                                         DRM_ERROR("Scatter allocation error, "
178                                                   "pagelist does not match "
179                                                   "virtual mapping\n");
180                                 }
181                         }
182                         tmp = page_address(entry->pagelist[i]);
183                         for (j = 0;
184                              j < PAGE_SIZE / sizeof(unsigned long);
185                              j++, tmp++) {
186                                 *tmp = 0;
187                         }
188                 }
189                 if (error == 0)
190                         DRM_ERROR("Scatter allocation matches pagelist\n");
191         }
192 #endif
193
194         return 0;
195
196       failed:
197         drm_sg_cleanup(entry);
198         return -ENOMEM;
199 }
200
201 int drm_sg_free(struct inode *inode, struct file *filp,
202                 unsigned int cmd, unsigned long arg)
203 {
204         drm_file_t *priv = filp->private_data;
205         drm_device_t *dev = priv->head->dev;
206         drm_scatter_gather_t request;
207         drm_sg_mem_t *entry;
208
209         if (!drm_core_check_feature(dev, DRIVER_SG))
210                 return -EINVAL;
211
212         if (copy_from_user(&request,
213                            (drm_scatter_gather_t __user *) arg,
214                            sizeof(request)))
215                 return -EFAULT;
216
217         entry = dev->sg;
218         dev->sg = NULL;
219
220         if (!entry || entry->handle != request.handle)
221                 return -EINVAL;
222
223         DRM_DEBUG("sg free virtual  = %p\n", entry->virtual);
224
225         drm_sg_cleanup(entry);
226
227         return 0;
228 }