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git.ipfire.org Git - thirdparty/kernel/linux.git/blob - drivers/staging/android/ion/ion_page_pool.c
2 * drivers/staging/android/ion/ion_mem_pool.c
4 * Copyright (C) 2011 Google, Inc.
6 * This software is licensed under the terms of the GNU General Public
7 * License version 2, as published by the Free Software Foundation, and
8 * may be copied, distributed, and modified under those terms.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
17 #include <linux/debugfs.h>
18 #include <linux/dma-mapping.h>
19 #include <linux/err.h>
21 #include <linux/list.h>
22 #include <linux/init.h>
23 #include <linux/slab.h>
24 #include <linux/swap.h>
27 static void *ion_page_pool_alloc_pages(struct ion_page_pool
*pool
)
29 struct page
*page
= alloc_pages(pool
->gfp_mask
, pool
->order
);
34 ion_pages_sync_for_device(NULL
, page
, PAGE_SIZE
<< pool
->order
,
39 static void ion_page_pool_free_pages(struct ion_page_pool
*pool
,
42 __free_pages(page
, pool
->order
);
45 static int ion_page_pool_add(struct ion_page_pool
*pool
, struct page
*page
)
47 mutex_lock(&pool
->mutex
);
48 if (PageHighMem(page
)) {
49 list_add_tail(&page
->lru
, &pool
->high_items
);
52 list_add_tail(&page
->lru
, &pool
->low_items
);
55 mutex_unlock(&pool
->mutex
);
59 static struct page
*ion_page_pool_remove(struct ion_page_pool
*pool
, bool high
)
64 BUG_ON(!pool
->high_count
);
65 page
= list_first_entry(&pool
->high_items
, struct page
, lru
);
68 BUG_ON(!pool
->low_count
);
69 page
= list_first_entry(&pool
->low_items
, struct page
, lru
);
77 struct page
*ion_page_pool_alloc(struct ion_page_pool
*pool
)
79 struct page
*page
= NULL
;
83 mutex_lock(&pool
->mutex
);
85 page
= ion_page_pool_remove(pool
, true);
86 else if (pool
->low_count
)
87 page
= ion_page_pool_remove(pool
, false);
88 mutex_unlock(&pool
->mutex
);
91 page
= ion_page_pool_alloc_pages(pool
);
96 void ion_page_pool_free(struct ion_page_pool
*pool
, struct page
*page
)
100 BUG_ON(pool
->order
!= compound_order(page
));
102 ret
= ion_page_pool_add(pool
, page
);
104 ion_page_pool_free_pages(pool
, page
);
107 static int ion_page_pool_total(struct ion_page_pool
*pool
, bool high
)
109 int count
= pool
->low_count
;
112 count
+= pool
->high_count
;
114 return count
<< pool
->order
;
117 int ion_page_pool_shrink(struct ion_page_pool
*pool
, gfp_t gfp_mask
,
123 if (current_is_kswapd())
126 high
= !!(gfp_mask
& __GFP_HIGHMEM
);
129 return ion_page_pool_total(pool
, high
);
131 while (freed
< nr_to_scan
) {
134 mutex_lock(&pool
->mutex
);
135 if (pool
->low_count
) {
136 page
= ion_page_pool_remove(pool
, false);
137 } else if (high
&& pool
->high_count
) {
138 page
= ion_page_pool_remove(pool
, true);
140 mutex_unlock(&pool
->mutex
);
143 mutex_unlock(&pool
->mutex
);
144 ion_page_pool_free_pages(pool
, page
);
145 freed
+= (1 << pool
->order
);
151 struct ion_page_pool
*ion_page_pool_create(gfp_t gfp_mask
, unsigned int order
,
154 struct ion_page_pool
*pool
= kmalloc(sizeof(*pool
), GFP_KERNEL
);
158 pool
->high_count
= 0;
160 INIT_LIST_HEAD(&pool
->low_items
);
161 INIT_LIST_HEAD(&pool
->high_items
);
162 pool
->gfp_mask
= gfp_mask
| __GFP_COMP
;
164 mutex_init(&pool
->mutex
);
165 plist_node_init(&pool
->list
, order
);
172 void ion_page_pool_destroy(struct ion_page_pool
*pool
)
177 static int __init
ion_page_pool_init(void)
181 device_initcall(ion_page_pool_init
);