2 * drivers/gpu/drm/omapdrm/omap_gem_helpers.c
4 * Copyright (C) 2011 Texas Instruments
5 * Author: Rob Clark <rob.clark@linaro.org>
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.
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
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/>.
20 /* temporary copy of drm_gem_{get,put}_pages() until the
21 * "drm/gem: add functions to get/put pages" patch is merged..
24 #include <linux/module.h>
25 #include <linux/types.h>
26 #include <linux/shmem_fs.h>
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
35 struct page
**_drm_gem_get_pages(struct drm_gem_object
*obj
, gfp_t gfpmask
)
38 struct address_space
*mapping
;
39 struct page
*p
, **pages
;
42 /* This is the shared memory object that backs the GEM resource */
43 inode
= file_inode(obj
->filp
);
44 mapping
= inode
->i_mapping
;
46 npages
= obj
->size
>> PAGE_SHIFT
;
48 pages
= drm_malloc_ab(npages
, sizeof(struct page
*));
50 return ERR_PTR(-ENOMEM
);
52 gfpmask
|= mapping_gfp_mask(mapping
);
54 for (i
= 0; i
< npages
; i
++) {
55 p
= shmem_read_mapping_page_gfp(mapping
, i
, gfpmask
);
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.
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.
74 * See this thread: http://lkml.org/lkml/2011/7/11/238
76 BUG_ON((gfpmask
& __GFP_DMA32
) &&
77 (page_to_pfn(p
) >= 0x00100000UL
));
84 page_cache_release(pages
[i
]);
86 drm_free_large(pages
);
91 * drm_gem_put_pages - helper to free backing pages for a GEM object
92 * @obj: obj in question
93 * @pages: pages to free
95 void _drm_gem_put_pages(struct drm_gem_object
*obj
, struct page
**pages
,
96 bool dirty
, bool accessed
)
100 npages
= obj
->size
>> PAGE_SHIFT
;
102 for (i
= 0; i
< npages
; i
++) {
104 set_page_dirty(pages
[i
]);
107 mark_page_accessed(pages
[i
]);
109 /* Undo the reference we took when populating the table */
110 page_cache_release(pages
[i
]);
113 drm_free_large(pages
);
117 _drm_gem_create_mmap_offset_size(struct drm_gem_object
*obj
, size_t size
)
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
;
125 /* Set the object up for mmap'ing */
126 list
= &obj
->map_list
;
127 list
->map
= kzalloc(sizeof(struct drm_map_list
), GFP_KERNEL
);
132 map
->type
= _DRM_GEM
;
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);
140 if (!list
->file_offset_node
) {
141 DRM_ERROR("failed to allocate offset for bo %d\n", obj
->name
);
146 list
->file_offset_node
= drm_mm_get_block(list
->file_offset_node
,
147 size
/ PAGE_SIZE
, 0);
148 if (!list
->file_offset_node
) {
153 list
->hash
.key
= list
->file_offset_node
->start
;
154 ret
= drm_ht_insert_item(&mm
->offset_hash
, &list
->hash
);
156 DRM_ERROR("failed to add to map hash\n");
163 drm_mm_put_block(list
->file_offset_node
);
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