1 /*
2 * drivers/gpu/drm/omapdrm/omap_gem_helpers.c
3 *
4 * Copyright (C) 2011 Texas Instruments
5 * Author: Rob Clark <rob.clark@linaro.org>
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License version 2 as published by
9 * the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
14 * more details.
15 *
16 * You should have received a copy of the GNU General Public License along with
17 * this program. If not, see <http://www.gnu.org/licenses/>.
18 */
19
20 /* temporary copy of drm_gem_{get,put}_pages() until the
21 * "drm/gem: add functions to get/put pages" patch is merged..
22 */
23
24 #include <linux/module.h>
25 #include <linux/types.h>
26 #include <linux/shmem_fs.h>
27
28 #include <drm/drmP.h>
29
30 /**
31 * drm_gem_get_pages - helper to allocate backing pages for a GEM object
32 * @obj: obj in question
33 * @gfpmask: gfp mask of requested pages
34 */
_drm_gem_get_pages(struct drm_gem_object * obj,gfp_t gfpmask)35 struct page **_drm_gem_get_pages(struct drm_gem_object *obj, gfp_t gfpmask)
36 {
37 struct inode *inode;
38 struct address_space *mapping;
39 struct page *p, **pages;
40 int i, npages;
41
42 /* This is the shared memory object that backs the GEM resource */
43 inode = file_inode(obj->filp);
44 mapping = inode->i_mapping;
45
46 npages = obj->size >> PAGE_SHIFT;
47
48 pages = drm_malloc_ab(npages, sizeof(struct page *));
49 if (pages == NULL)
50 return ERR_PTR(-ENOMEM);
51
52 gfpmask |= mapping_gfp_mask(mapping);
53
54 for (i = 0; i < npages; i++) {
55 p = shmem_read_mapping_page_gfp(mapping, i, gfpmask);
56 if (IS_ERR(p))
57 goto fail;
58 pages[i] = p;
59
60 /* There is a hypothetical issue w/ drivers that require
61 * buffer memory in the low 4GB.. if the pages are un-
62 * pinned, and swapped out, they can end up swapped back
63 * in above 4GB. If pages are already in memory, then
64 * shmem_read_mapping_page_gfp will ignore the gfpmask,
65 * even if the already in-memory page disobeys the mask.
66 *
67 * It is only a theoretical issue today, because none of
68 * the devices with this limitation can be populated with
69 * enough memory to trigger the issue. But this BUG_ON()
70 * is here as a reminder in case the problem with
71 * shmem_read_mapping_page_gfp() isn't solved by the time
72 * it does become a real issue.
73 *
74 * See this thread: http://lkml.org/lkml/2011/7/11/238
75 */
76 BUG_ON((gfpmask & __GFP_DMA32) &&
77 (page_to_pfn(p) >= 0x00100000UL));
78 }
79
80 return pages;
81
82 fail:
83 while (i--)
84 page_cache_release(pages[i]);
85
86 drm_free_large(pages);
87 return ERR_CAST(p);
88 }
89
90 /**
91 * drm_gem_put_pages - helper to free backing pages for a GEM object
92 * @obj: obj in question
93 * @pages: pages to free
94 */
_drm_gem_put_pages(struct drm_gem_object * obj,struct page ** pages,bool dirty,bool accessed)95 void _drm_gem_put_pages(struct drm_gem_object *obj, struct page **pages,
96 bool dirty, bool accessed)
97 {
98 int i, npages;
99
100 npages = obj->size >> PAGE_SHIFT;
101
102 for (i = 0; i < npages; i++) {
103 if (dirty)
104 set_page_dirty(pages[i]);
105
106 if (accessed)
107 mark_page_accessed(pages[i]);
108
109 /* Undo the reference we took when populating the table */
110 page_cache_release(pages[i]);
111 }
112
113 drm_free_large(pages);
114 }
115
116 int
_drm_gem_create_mmap_offset_size(struct drm_gem_object * obj,size_t size)117 _drm_gem_create_mmap_offset_size(struct drm_gem_object *obj, size_t size)
118 {
119 struct drm_device *dev = obj->dev;
120 struct drm_gem_mm *mm = dev->mm_private;
121 struct drm_map_list *list;
122 struct drm_local_map *map;
123 int ret = 0;
124
125 /* Set the object up for mmap'ing */
126 list = &obj->map_list;
127 list->map = kzalloc(sizeof(struct drm_map_list), GFP_KERNEL);
128 if (!list->map)
129 return -ENOMEM;
130
131 map = list->map;
132 map->type = _DRM_GEM;
133 map->size = size;
134 map->handle = obj;
135
136 /* Get a DRM GEM mmap offset allocated... */
137 list->file_offset_node = drm_mm_search_free(&mm->offset_manager,
138 size / PAGE_SIZE, 0, 0);
139
140 if (!list->file_offset_node) {
141 DRM_ERROR("failed to allocate offset for bo %d\n", obj->name);
142 ret = -ENOSPC;
143 goto out_free_list;
144 }
145
146 list->file_offset_node = drm_mm_get_block(list->file_offset_node,
147 size / PAGE_SIZE, 0);
148 if (!list->file_offset_node) {
149 ret = -ENOMEM;
150 goto out_free_list;
151 }
152
153 list->hash.key = list->file_offset_node->start;
154 ret = drm_ht_insert_item(&mm->offset_hash, &list->hash);
155 if (ret) {
156 DRM_ERROR("failed to add to map hash\n");
157 goto out_free_mm;
158 }
159
160 return 0;
161
162 out_free_mm:
163 drm_mm_put_block(list->file_offset_node);
164 out_free_list:
165 kfree(list->map);
166 list->map = NULL;
167
168 return ret;
169 }
170