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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 <linux/slab.h>
36#include "drmP.h"
37
38#define DEBUG_SCATTER 0
39
40static inline void *drm_vmalloc_dma(unsigned long size)
41{
42#if defined(__powerpc__) && defined(CONFIG_NOT_COHERENT_CACHE)
43 return __vmalloc(size, GFP_KERNEL, PAGE_KERNEL | _PAGE_NO_CACHE);
44#else
45 return vmalloc_32(size);
46#endif
47}
48
49void drm_sg_cleanup(struct drm_sg_mem * entry)
50{
51 struct page *page;
52 int i;
53
54 for (i = 0; i < entry->pages; i++) {
55 page = entry->pagelist[i];
56 if (page)
57 ClearPageReserved(page);
58 }
59
60 vfree(entry->virtual);
61
62 kfree(entry->busaddr);
63 kfree(entry->pagelist);
64 kfree(entry);
65}
66
67#ifdef _LP64
68# define ScatterHandle(x) (unsigned int)((x >> 32) + (x & ((1L << 32) - 1)))
69#else
70# define ScatterHandle(x) (unsigned int)(x)
71#endif
72
73int drm_sg_alloc(struct drm_device *dev, struct drm_scatter_gather * request)
74{
75 struct drm_sg_mem *entry;
76 unsigned long pages, i, j;
77
78 DRM_DEBUG("\n");
79
80 if (!drm_core_check_feature(dev, DRIVER_SG))
81 return -EINVAL;
82
83 if (dev->sg)
84 return -EINVAL;
85
86 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
87 if (!entry)
88 return -ENOMEM;
89
90 pages = (request->size + PAGE_SIZE - 1) / PAGE_SIZE;
91 DRM_DEBUG("size=%ld pages=%ld\n", request->size, pages);
92
93 entry->pages = pages;
94 entry->pagelist = kcalloc(pages, sizeof(*entry->pagelist), GFP_KERNEL);
95 if (!entry->pagelist) {
96 kfree(entry);
97 return -ENOMEM;
98 }
99
100 entry->busaddr = kcalloc(pages, sizeof(*entry->busaddr), GFP_KERNEL);
101 if (!entry->busaddr) {
102 kfree(entry->pagelist);
103 kfree(entry);
104 return -ENOMEM;
105 }
106
107 entry->virtual = drm_vmalloc_dma(pages << PAGE_SHIFT);
108 if (!entry->virtual) {
109 kfree(entry->busaddr);
110 kfree(entry->pagelist);
111 kfree(entry);
112 return -ENOMEM;
113 }
114
115 /* This also forces the mapping of COW pages, so our page list
116 * will be valid. Please don't remove it...
117 */
118 memset(entry->virtual, 0, pages << PAGE_SHIFT);
119
120 entry->handle = ScatterHandle((unsigned long)entry->virtual);
121
122 DRM_DEBUG("handle = %08lx\n", entry->handle);
123 DRM_DEBUG("virtual = %p\n", entry->virtual);
124
125 for (i = (unsigned long)entry->virtual, j = 0; j < pages;
126 i += PAGE_SIZE, j++) {
127 entry->pagelist[j] = vmalloc_to_page((void *)i);
128 if (!entry->pagelist[j])
129 goto failed;
130 SetPageReserved(entry->pagelist[j]);
131 }
132
133 request->handle = entry->handle;
134
135 dev->sg = entry;
136
137#if DEBUG_SCATTER
138 /* Verify that each page points to its virtual address, and vice
139 * versa.
140 */
141 {
142 int error = 0;
143
144 for (i = 0; i < pages; i++) {
145 unsigned long *tmp;
146
147 tmp = page_address(entry->pagelist[i]);
148 for (j = 0;
149 j < PAGE_SIZE / sizeof(unsigned long);
150 j++, tmp++) {
151 *tmp = 0xcafebabe;
152 }
153 tmp = (unsigned long *)((u8 *) entry->virtual +
154 (PAGE_SIZE * i));
155 for (j = 0;
156 j < PAGE_SIZE / sizeof(unsigned long);
157 j++, tmp++) {
158 if (*tmp != 0xcafebabe && error == 0) {
159 error = 1;
160 DRM_ERROR("Scatter allocation error, "
161 "pagelist does not match "
162 "virtual mapping\n");
163 }
164 }
165 tmp = page_address(entry->pagelist[i]);
166 for (j = 0;
167 j < PAGE_SIZE / sizeof(unsigned long);
168 j++, tmp++) {
169 *tmp = 0;
170 }
171 }
172 if (error == 0)
173 DRM_ERROR("Scatter allocation matches pagelist\n");
174 }
175#endif
176
177 return 0;
178
179 failed:
180 drm_sg_cleanup(entry);
181 return -ENOMEM;
182}
183
184int drm_sg_alloc_ioctl(struct drm_device *dev, void *data,
185 struct drm_file *file_priv)
186{
187 struct drm_scatter_gather *request = data;
188
189 return drm_sg_alloc(dev, request);
190
191}
192
193int drm_sg_free(struct drm_device *dev, void *data,
194 struct drm_file *file_priv)
195{
196 struct drm_scatter_gather *request = data;
197 struct drm_sg_mem *entry;
198
199 if (!drm_core_check_feature(dev, DRIVER_SG))
200 return -EINVAL;
201
202 entry = dev->sg;
203 dev->sg = NULL;
204
205 if (!entry || entry->handle != request->handle)
206 return -EINVAL;
207
208 DRM_DEBUG("virtual = %p\n", entry->virtual);
209
210 drm_sg_cleanup(entry);
211
212 return 0;
213}